The Soviet Microelectronics Industry:echnology Barrier
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The Soviet Microelectronics Industry:echnology Barrier
This papc' *
prepared by
Office ol
Analysis
Science i
Wypoos
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10
The Soviet Microelectronics Industry:echnology Barric
USSR has an acute >honage of very-large scale integrated (VLSI)
These intcgr^ied circuits arc necessary to meel the challenges
by General Secretary Gorbachev's industrial moderm/.ation plans
and will be criticalumber of advanced weapon Systems the Soviets arc developing for deployment in, lhc manufacture of VLSI devices requires levels of precision, complexity, cleanliness, andthat the Soviets have not yet been able to reach in ihe mdusiry at large. Allhough they achieved full-volume production of nrsl-gcneration VLSIK memories)evice yields remain well underercent (compared with device yields ofercent in US plants) and reliabilityroblem. While the USSRearth ofhips, lhc West is manufacturing second-generalion VLSI devices (thatKegabit memories) in volume
Second-genera lion VLSI chips present the Soviets wuh formidable manu factoring challenges TuH-scale produclion requires more sophisticated manufacturing equipment than lhat used for less advanced ICs. The Soviets probably haveechnology barrier tit ilic sccond-gcncra-lion VLSI level; to produce these devices in volume, they will have to acquire or produce substantial amounts of advanced mmufacturingto retool many of their IC production plant?
The Soviets have several options for acquiring lhc icchnology necessary io iClOOl Iheir microelectronics industry:
domestic development and production programs.
Coordinating research and produclion efforts wuh fcasi European mem bers of the Council for Mutual Economic Assistance (CEMA)
Wesiern technology,possibly in pari through joint-venture efforts with Western companies
The preferred solution from ihe Soviets' perspective is to rcequipindustry with indigenous productionarge industrial infrastructure to support the developmentof microelectronics manufacturing equipment, lhc Sovietshave been unable lo manufacture high-quality equipment ina microclecuonics equipment sector thai turns out
poor-quality products because of resource and labor problemselatively antiquated production environment
^Janalysis of commercial Soviet ICs or'^nccd at lhc medium- and urge-scale levels of integration confirms ihtQ ^assessment of the poor quality of indigenously produced equipmeni This analysisumber of equipment detiCicr.Cics that suggest manufacturing problems ai lhc VLSI level of production will be even more serious Consequently, we doubt thai ihe Soviets inill be able lo produce equipmeni capable of manufacturing ICs that match the complexity or performance levels of Western devices Soviei leading-edge pioduciion technology probably will continue io lag that of ihe Wesi by one lo Iwo IC generations.
To supplement indigenous efforts, the Soviels will continue to pursue cooperation wiih the East European member countries of CEMA. Within CEMA, the USSR can gain most through increased cooperation with East Germany The East German combine Carl Zeiss Jena is Eastern Europe's leading producer of microelectronics manufacturing equipmeni, and it ships approximatelyercent of ils outputther CEMA countries, chiefly ihe USSR. East Germany's success in acquiring criticalf" IC production equipment and technology and us resulting success6 of achieving pilot production of second-generation VLSI devices illusiraics the lype of access to East European and Western lechnology lhc Soviets hope to acquire through their CEMA relationships. Soviet benefits from CEMA coopciaiion probably will be limited, however, by the desires of the East European member countries to develop high-technology industries to suppofi their own objective;
To compensate for CEMA's inability lo produce high-qua lilymanufacturing equipmeni in volume, the Soviets will continue to place great emphasis on acquiring Western machinery. Wc believe that, since the, the Soviels through both legal, licensed purchases and illicit acquisition programs have acquired enough IC manufacturing equipment from the West to oulfit uphird of their IC production lines. Rccqiiipping iheir industry to support the production of second-generation VLSI devices couldimilar level ol Westernin
The USSR will continue toexploii any weakness in Western export controls and may attempt toonstituency in the West thatelaxing the COCOM regulations governing advanced microelectronics technology. The Soviets may turn increasingly to joint ventures with Western firms to oblain microelectronics manufacturing technology and know-how and. in some cases.acilitate the producuon and marketing in lhc Wcsl of Soviet-designed manufacturing cquipmcn "
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>*eet^"
The Soviets are having trouble producing ICs at the VLSIarge measure because of itudequaic supplies of advanced manufacturingIhis paper addresses lhc nature of the Soviets' equipment shortfall, analyzes the icasons lor the shortfall, and assesses Soviei options for overcoming i
Wc havehorough analysis of all reporting on Soviet microeleciroutes mjiiulJciuring equipment Wc have informanon on the range of equipmeni produced in the Soviei Union and ihe quality and technology Icvei of Somci equipment compaicd wiih thathe West. Wc are also ableic specific productsev microelectronics equipment design bureaus and production plant
We arc raced with major information gaps, however, on theand applicalion of Soviet microelectronicsand on the organizational dynamics of the sector ofindustry thai produces this
"Tias1 biased in favor of microelecironics device production 'm?tcaW*of production of ihe equipmeni thai manufactures those devices. In addition, most reporting on production equipment is fragmentary.and inadcquaic for rigorousr Soviet equipment produclion capabilities or retooling requirements
Because of these large information gaps, we have hadome to gripswith the nature of the Sovicis' manufacturing equipmeni shortfall, as well as the possible reasons for the shortfall. To lhai end wc:
ariety of Sovietadvanceddetermine the types and qualily of equipment the Soviets usedanufacture ihem.
Examined Sovtei-Easi European cooperative programs in ihe field of IC produclion equipmentdentify areas where the Soviets are attemptingupplemcni iheir indigenous capabilities and their program for acquiring Western
Reviewed the Soviets' technology transfer program to identify trends in the types and quantity of Western equipment they have acquired over lime and to gauge thehey have made in overcoming areas of technological deficiency.
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Microelectronics Jargon
A semiconductor is an element whose electricalis less than thatonductor, such as copper, and greater than thai ol an insulator, such as gloss.
A transistoremiconductor dence that acts primarily as cither an amplifierwitch
A waferhin disk of semiconductor material on which many integrated circuits arc fabricated al One time The circuits are subsequently separated and packaged individually.
An integrated circuit (IC)emiconductor circuit combining many electronic components suchingle substrate, usually silicon An IC ts commonlyhip
A memory IC stores large volumes of information in tht form of electrical charges.
A DRAM (dynamic random access memory)ype Of IC in which data are stored by meanseriodically refreshed electricalK DRAM, for example, storesieces of information. DRAMs are noted for their Speed in storing or retrieving information and their low manufacturing cost
Minimum feature sue is the width or diameter of ihe smallest element on an IC and is uiedeasure of circuit complexity. Minimum feature sizes vary fromicrons on small-scale integrated circuitsicron on second-generation veryuman hair, by contrast,icrons in diameter.
Oxidation is ihe process of growing an oxide layer on the "Ofer surface to serveubstrate far the lithography steps.
Lithography Is the process ofircuit pattern containedask or stencil IO the silicon wafer
A maskransparent plate or stencil covered with anof patterns used in making ICs. The mask is used toortionilicon wafer for subsequent processing
Utcriing is the process ofaytr or layers of maierial. such as oxides or metals,ilicon wafer
Doping is the process in which selected impurities are impregnated on specific areasilicon wafer to change its electrical characteristics
microprocessoringle IC on whnh theand control logicomputer a't placed. It is sometimes referred toomputerhip."
TheMicroelectronics Industry:echnology Barrio
Struggling Industrv
The Soviets, since the. havearge microelectronics research and development) and production program, imported advanced Western manufacturing equipment, and copiedWesternespite their efforts, they have been unable to produce complex integrated circuits (ICs) in quantities and qualitieswith their large investment in industrial capacity (see inset, "Integratedoday, the USSR's IC production capability is only about one-tenth thai of the United States, and Soviet ICs, on average, are aboutr">eraiions behind the West in technology level
Most Soviet ICs are manufactured at the small-scale (SSI) and medium-scale (MSI) levels of integration The Soviets aic manufacturing growing numbers ol large scale integiaied circuitsut aresevere obstacles in manufacturing high-quality advanceduch as memory andcircuits at the very-large-scale integrated (VLSI) level Although the Soviets achieved full-volumeK dynamic random accesi incDRAMKfiisi-gcncration VLSI)evice yields arc well underercent (compared wiih device yields of over SSjirjcitni in US plants) and reliabilityroblem,/
: :hc
USSKearthemory chips, while the West iscgab'1VLSI) in large volum
ompares produclion milestones for DRAMs for the Uniied Slates and the USSR. The design structure of DRAMs is simple and repetitive, and DRAM produclion is constrained mainly bytechnology. Hence, theyood indicator of
Figure 1
DRAM Production Milestones. US Versus USSR
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K
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K
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Ytmante of
USSR
the relative icchnology level of IC manufactunngthe figure indicates, the Soviets narrowed the US lead in DRAM technology io three to fourhend tbethey introduced devices at the LSI and first feneration VLSI levelsbe emerceacc of Mccrrtd generation VLSIhowever, lhai gap has wtdened lo eight to nine years. The Soviets hare achieved only pilot to limned-voivtne production of second generation VLSI de-"ices, wc do not expect them to achieveolumc production of iheRAM until0 and productionmegabit memories until iheft.
erm used hnci" "Mudo tl* Unu.-il Suk-.
Mlvu'ijtMftfjubl. lapr
/
Integrated Circuit's
microminiaturization ofcomtionenti in the form of the integrated -has revolutionized military and tommtrctol electronics and has spurred most of the world'sachievements of iheo decades
Integrated circuits arr electrical devices that combine many components such as transistors,pati tors, ond resistorsiniaturized circuit Many ICs are processedhin wafer of semiconductor material, usually silicon. They are subsequentlyseparated, and packaged individually.
The semiconductor industryperhaps ihe onlythai reports Us pro-getsogarithmic scale8 an ICingle circuit,Cs
contain OS manyillion memory bits. Integrated circuits can be defined by their relative level of integration, that is. the number of circuit functions incorporated in ihe device. Increasing circuit densityicroscopic level results in increased reliability and performance ol the host system, while decreasing System Stic and power requirements and decreasing electronics function costs The level of integration is usually defined by both the number of transistors per IC and the minimum featureincircuit elements.icronillionthhe levels of IC complexity {Western lexicon) are keyed to representative device types in the following tabulation:
though the Soviets may soon initiate what (or them may be defined as "full-volume production" of second-generation VLSI devices, we estimate that production yields for these devices will certainly be well underercent. We judge that one of the major reason* for the Soviets" low IC yield rates andtechnology lag is the lack of high-qualityequipment. Second-generanon VLSI chips present the Soviets with formidable inanufacluring challenges. With minimum feature sueicron and with up tomillion transistors intccraicdingle chip, lequirements for sophisticated design, processing, and icsi equipment aic heightened
substantially The Soviets appear io haveechnology barrier at this level thai they mayonly by producing or acquiring more advanced manufacturing equipment to retool many of their IC production plants Failure to keep pace with Western VLSI technology would limit severely ihe Soviets' ability to meet the challenges posed by both advanced US weapon sysiems and Gorbachev's industrialplans. (Sec" ihe growing Soviet demand for advanced IC'
oct
Microelectronics Manufacturing Equipmeni: The Industrial Base
Microelectronics manufacturing equipment is pep. ducedector of the Soviet microelectronics industry. We have identifiedoviet facilities ihat are involvednd production of microelectign-ics manufacturing equipment and inand adapting foreign equipment (seche bulk of Ihese facilities o tbe Ministry of ihc Electronics Industry
hc defense industrial ministry responsiblend prtVveiWnCT'Tleclronic components and subassemblies.
Three directorates "ilhin ibc MEP are known to be involved in ihe design and production ofmanufacturing equipmeni. Many of themanufacturing facilities arc subordinate to the
Iti! mhncrccoi ai* suboidiaate to the Ministries ol ihe Radio ladlifri. Instrument Muting. Automation. andrems Indusiiy. Defense Inlusirt. Nonttiiou- Mctjllurct. jrW Mi|tiei and Seeondaiy SpcculiKd HCueauo*M SovietWnun Auoo'sies oft
HecrU
Zelenograd Scientific Center for Microelecironici
The Zelenograd Scientific Center for Microelectronics is the closest Soviet facsimile to the Umted States' Silicon Valley. The Center is composed of several facilities that are engaged innd production of ICs, semiconductor materials, and microelectronics produclion equipment. Zelenogradocal point for reverse-engineering Western equipment. Although none of Zetenograd's facilities are engagedn the design and production of microelecironicI manuJaeturing> inScientific Research Institute for thr Development irf Precision Machine Building ffi/ITMl and the Scientific Research InSlituteof Precisioned Substantialo further developingUSSR's line of wafer-processing cauipmeifstji
Second Chief Directoratehe organizationresponsible for developing and producingdevices.,including ICs. Tlie Sovietskey microelectronics ceniers inVoronezh, and Zclcnograd ibat aieunder the Second CD (see inset. "TheScientific Center forhe primary function of these centers issemiconductor devices, many alsomanufacUjring equipment. Innumber ofto ttic ruunn .tnd theCDs are also
l design ai'di'! 'ii niiclei irufliW manufacturing
3.
Soviet facilities design and produce equipment Ihat is used throughout the IC produclioncrystal growth through automated testing ofdevices.dentifies all major Soviet microelectronics equipmeni design bureaus andplanis and correlates specific equipment lines wiih each
Analysis indicates thai the key facilities for designing, copying, and reverse-engineering microelectronics manufacturing equipment include:
Electro-Technical Insiimie r'mmi (jlyanov. Leningrad
Design Bureau for Precision Electronic Machine Buildinginsk (see inset)
Vilnius Design Bureau
- Research Design Bureau for SemiconductorEquipment, Voronezh.
Scientific Research Institute for the Development of Microelectronics Equipment. Zclencgrad.
Scientific Research Institute of Precision Machine Building, ZelenOgrad
icai equipment ucsixii uiojcui ukcs an averageproduciion of tlicthat lhc designomplete IC produciionabout five years.
iece of foicigi.-ni.iut.ntake ss link as eight months MEP pfien purchases West-cm IC manufaciuringiis design bureaus io copy the desigr.
Many of the Soviets' equipment research institutes and design bureaus have dircci links to facilities that arc involved in the series production of theirequipment designs. Analysis indicaiesandful of plants arc ihe leaders in producing microelectronics manufacturing equipmeni These are:
Elekironmash Experimental Produciion Plant for Semiconductor Machine Building. Minsk.
Semiconductor Machine Building Plant. Moscow.
Building and Tout Plant, Riga (sec inset)Microelectronics Plani Number III. Voronezh.
Although we lack comprehensive reporting aboutof modernization and pc'forinancc of allproducing microelectronicsreporting on individual plantsector ill-equipped iq support amicroelectronics
many Soviei equipmentac* of quality resources and skilled labor, poorof manufacturing equipment,ow level ol process automation compared withrn facilities, resulting in poor quality product
The Technologyol Equipment Used in Soviet Planis
Soviei microelectronics planis arc outfitted with boih domestic and Western manufaciuring equipment Wc assess that Sovietoutfitstwo-thirds of IC manufacturingusedroduce primarily standard civilian devices.equipment, On the other hand, is usually usedroduce Sovie! siaic-of-ihe-ari. military-specification IC;
Analysts of ICs used in standard civilian products confirms tlnf* Assessments of the poor quality of indigenous^ produced equipment The characteristics of these ICs indicate that ihe bulk of ihe microelectronics manufaciuring equipmeniin the USSR generally is well below Western slandards in lerms of technology and performance and lags Western-produced equipment by one to two generations. To upgrade iheir average level of IC produotion from MSI to LSI and early VLSI lechnol-ogy, the Soviets, as did the West, will have to replace virtually all of their current equipment inventory.
Dttlgn Bureau for Precision Electronic Machine Building
Design Bureau for Precisionajor Soviet designer of ICequipment. This facility was founded inihend is organized under the jurisof the Planar Scientific and Productionand the MEP. Asidemallihat rr verse-engineers ICs obtained fromwe have no evidence that KBTEM is engagedother lhan the design ofequipment. KBTEM is colocaiedpilot production plant Elektronmash. whichmockupt. prototypes, andand performs limited series manufacturedesigned by
Jde-
scribed the equipment manufacturing areat at neat, clean, and efficiently layed outull range of metalworking equipment
all con-
C iiimpldv9 and the facilities were tipcatumnir^
KBTEM is also associated with three Planarplants in Vitebsk. Riga, and Gor'kiy that are involved in the series production of itsequipment designs. The design bureau is also associated with and designs equipment for other produciion planis and research Institutes throughout the USSR, including the Scientific Research Institute fot Micro-Instruments in Riga, ihe ScientificInstitute for Micro-Equipmeni in Yerevan, an institute in Kiev, the Mikron and Angstrem Plants in Zelenograd.emiconductor plant in Voronezh
KBTEM and ihe Planar Amalgamation specialisedesign and production of photolithographicespecially equipment for the production(pattern generators,and maskafer scribes,bonding equipment; automatic probes foe ICand IC packaging equipment. With fewequipment produced by the Planar complexexported outside the USSR because themicroelectronics industry consumes almostus output
icroelectronics manufacturing equipment appeared io be competitive with Slate-of-lheart Weitrm modelsrespect lo raw manufacturing capability and level of automation f"
quipment was not competitive with Western equipment with respect io processing capability foe complex IC designs and did not support rapid conversion from One product design to another.
2
Soctet Btltflf Opt aft. military-ipcciRcalion ICs UStt-ally acc produced on more sophisticated manufacmr-ing equipmeni, much of which has been acquired illegally from (he ysisshows thai these devices are oi much higher quality than standard chips processed primunly on indigenous equipmeni allhough their performance isbelow that of Western ICs Wc judge that, allhough much of ihe equipment used for Sonet slate-ol-ihc-art IC production is genera IK adequate for
production of lirsi-scncrjtton Vl.il devices,at the second-generalien VI SI level willretooling in
This judgment is basedomprehensiveol the IC manufacturing equipment thai the Soviets employ in their microelectronics plants (see
Riga Machine Building and Tool Pimm,
Riga Machine" Tool Plant nIC lesthis
plant was founded6 and hat bttn subordinate to the Planar Scientific and Productionof the MEP since themployees produce equipmeni that is designed by thepecial Design Bureau and KBTEM In Minsk, which itember of ihe Planar
Riga stands out at an exception lo ordinary Soviet equipment production practices Most precisionplants perform oil equipmentfunctions from machining through final assembly The Riga flam, on the other hand, has three branchFuryborg, and Novor;hr'--
1
upmmmmt fchining functions ' s no finished production at any of the be onessembly i, performed ji
r
Although Riga obtains most of itsignificant amount of equipmentfrom Japan. West Germany. France, and the
TailFlaaae promt)
madreferred io ai 'ike rlnliraa/i
imdaii
Umied Slates the plant still lacks adequateof quality capital equipment Ihe plant alio experiences problems -nth poor peoduction tech-mques lack of consistent quality control, and bottle-mmrl' ,upply of components and spare parts
iga has manufactured exclusivelyland especially IC Iflljof which ts copied or reverse-engineeredmodels. Plant products include laserZond-serirs automatic testnd Orion-tents microwelders
u'ochuresMJteeatt key tethmcal parantetertbi ai much as an order of magmtude and
technological level ofesta nkewfour to five years bekind US state of the an
we ailirioulea
plants throughout the Soviet Union, including the Riga Semiconductor Plant the Angstrtm Plant in Ztlenograd. and the Svetlana Productioneningrad Riga also has customer! in Bulgaria. East Germany, and Yugoslavia
txiga'sequipment requires more strmgenl environmental controls, such as temperature and cleanliness requirements, lhan most of the customer planis can maintain -preventing them from operating the equipmeni at maximum efficiency or for the duration of the equipment warranties It is common practice for customers so order extrato they can cannibalize them fnr spare
Sof>r
The Sovieu produce polysilicon with outdated,batch-processinpitfrom
hen COCOM embargoed siliconequipmeni and know-how' Although Western producers in recent years have upgraded iheirhardware and improved chemical purification processes to improve silicon output, there is nolhat Soviei producers have done likewise
In addition to polysilicon produclion problems, the Sovietshortage of crystal pullers for volume production of high-purity, large-diameter (overnch) silicon ingots (seeany Soviet sources have reported lhat domestically produced crystalare of poor quality, and COCOM controlsrestrict the USSR's legal access to Westernand machinery. Soviet problems in controlling the physical and chemical variables of lhc ingot growth process have ledvicld rates and low reliability levels of ICs
Improvements in crystal growth technology, however, may be on the horizon. In the spring8oviet irade exposition in India, ihe Soviets displayed an indigenously produced crystal puller with andigital-control capability to regulate crystal cross section and to enhance the purity of the ingot. The lack of such an automated control capabiii'-reportedly has impeded Soviet IC production
Wafer preparation equipment includes:
Saws thai slice wafers from monocrystallinc silicon ingots.
Lapping machines that smooth wafer surfaces andniform finish.
' COCOM. the Coordimtinj Cotnmiiuc 'opuniible rur idimnit triing multilateral open controls.esiibliihedorum for Western efforts to control ihe espou of military relatedie So-xt Dice andOM current. It ik crmiimscrl ol Hie Unitednited Kmeikun TmWi I'urtVital. Niw-ay. Ibe Netherlands. Luscnbourg. Iiorn lijli, C'ccce. Fruncc. live Fcdenl RepuDlic ofiii. Belgium, and
Polishers iligclat, mirrorlikc surface on the wafers
In the i. SSR. the I'M ml SI ui" ilii Wiiivie 'or theu/ihc Ininolui) iii ihr Praduciiw of Co* i'd Srsirrm in
'h.nSvritiMil sinil 'tint miltoirii* Peru-liu lu>iHkiceite-
The USSR ii particularly dependent on Western wafer-slicing equipmeni because of the poor qualily of ils own machines (seeoviet slicingoften damage wafers during processing and encounter problems with vibration that demandblade adjustments Early attemptseverse engineer US machines reportedly were unsuccessful because the Soviels had difficulty manufacturing and aligning the diamond-coated saws. The Sovietshave decided to continue purchasing the saws from Ihe United Slates or West Germanyost of abouler machine rather than rel<on their own poor-quality ones, whichj^
arc more costly to operate in the Ions
Compute'-aided design equipment ts used to draw the specific electrical circuit and to prepare lhat pattern for transferilicon wafer As ICS. andmicroprocessors, become more complex, design time becomesong In ihe Weildesign (CADI systems have becomeo the IC development process, ensuring 'msh-qualiis chips while reducing dcvdonmcni limes
r
^jrie "sovieu1 ilcvtCrs ti>iugAD icCliniQues as early as theur technical jnjIjsKSoviet ICsintage is consilient with this information CAD programs were usctl tod simulate the effect of IC design and architectural changes, allowing Soviet designersnOdtis Wcitcri LSI designs to meet domesne rcquircmcnr
^analysisfJs vintage IC( indicates, heevcr. mat ihe Soviets' CaD capabilities have not kept pace with designrecent CAD programs evidently are noi sophisticated enough to model and simulate the eilcei oi' IC changes at the VLSI level of COntpiesii'
advanced Wesiern deuces, in lieu of developing their own designs io avoid tncieaicd IC development times and io aid the development of hoih new ICs, suchbu microprocessors,mproved versions of curreni ICs
Fstocrtccoviei lagAD capabtlny in lhct. constucni sviih evidence thai the Soviels arc coatiraiaed by poor CAD sysiemsther industries, such as aircraft The Scwiets will be unable, to meet projected - ai the second-generation VLSI level until they develop or acquire more sophist tea ted CAD tn c *rn*iware io improve integrated circuit desig.
mnk .ir arid lithography equipment includes
Optical paitein generators or eleciron beamcaml mask wrilCfl lhathotomaskesigned IC circuit iMiittin
Siep-and-repeat cameras ihai optically reduce and reproduce rinal sue nmtci masks
iovitis nave adopicd tne practice oi cop* 'ns;
Sorter
A vjf:etyv' thographj
machine* ihaiin. ihe ciieuii design ontoicon wafers
^ana'lysis of IC* Indicates ihaimasKmaking and lithocruphy equipment limitol standard ICs produced withhul currently areimiting factorSoviet stale of ihr -art ICs ai theusing illicitly acquired Westernstate-of-the-art ICs cihibit veryeasure of circuit density)idthsicrons ami alignment accuracies onicron for ihc neat few years, ibe Sovietssatisfied wiih expanded use of scanningthai offer high throughput and(or production up io theProduction of more advanced devices, such4-mcgabu DRAMs. however, will requirelo retool their IC plunls with Ihcstepping projection aligners thai can
IniKotco* IVumChina MasaagihrKi-oxk lasaiiata.i dnii-ina unaayiayaaal Bat
handle circuit details ai the submicion level and ioeam liihographu tvstems io producemasks (see figure 7|
Wa/f'-proffsting fouipmefll includes
Etching machines that selectively remove ;itemed layers of tbc wafer surface exposed during lithography
Deposition equipment thai depoaas metallic orcompound films on the wafer surface.
Doping systems that introduce precne quantities of impurities, or dopants, inio specific portions of the -iifer io achieve desired electrical characteristics.
Etching, as well as lithography,imitingchieving fine-resolution line widths Althoughproduced etching equipment limits theof standard Soviet ICs. Western equipmentse contributes to well-denned circuit lines for Soviet state-of-the-art LSI chipsj^ ^analysis show* thai the Soviets can produce CMpat wuh well-formed, vertical walls, an indication ihat they have been successful in applying plasma etching techniques to then advanced devices vice acid (or chemical)
older process that is used lorICs with line widths greaterassess that Ihe use of plasma etching systemsadequate to meet Soviet processingfirst-generalion VLSI devices. The Sovietsto acquire the more advanced reactivesystems to meet upcoming productionfor second-generation VLSI devices.produce straighterpro-
duce ICs al greater throughputs
The Soviets' capability inof thin meiallic layers on thendividual circuits on eachperhapsmost serious shortcoming in processing wafers.
iana lysis of ICs indicates thai ihe Sonets stm use ioc outdated evaporaiion technique for processing even then best devices With evaporation, ihe Souicii
have had difficulty controlling alloy composition on the ICroblem they probably will have to overcome to produce devices al the second-generation VLSI level. The mote advanced sputtering technique is usually ihe mclhod of choice in ihe West because of its ability to deposit high-quality films at higher rates and at lower pressures and temperatures lhan cvano ratioa. therebyroduction. Although the bast Germans market Sputtering systems, there is no evidence that the Soviets are yet employing this eqii in their IC production tines (sec figure 8)
c Jinalysis of ICs indicates thai the Soviets' eapaDiiny indeposition of an oxide layer on the waier surface to protectively seal thelimits ihe performance of standard ICs processed on indigenous equipment. IC exploitations indicaic, however, ihai illicitly acquired Westernequipmeni it adequate for processing Soviei state-of-the-an ICs We assess thai this equipment will probably support production of second generation VLSI devices Current capabdiiics will probably be adequate until ihe Sovieu begin producing chips ai thestep beyond vecond-generauon VLSI
iecirn.il components are created on the siliconintroducing selectedjreayif ihe wafer exposed in the patternlhat the Soviets now
use an mat hich dopants
areagnetic field, and tben physically implanted into the silicon wafer Ihis lecbrsroue allows belter control of ihe doping process than lhc older, conventional diffusion technique, which relied on heat to spread dopants from the wafer surlacc into the depths of the wafer Illicitly acquired Western ion implantation equipment probably is ade quale to support production of chips up toK DK AM level Bui pilot productionegabitwill probably force the Soviets to produce or uire equipment wiih enhanced computer control
IC assembly and packaging equipment includes;
Wafci taws (hai separate individual ICsafer
Die bonders thai attach the (unciional pans of ilic IC ioa package.
- Wire bonders that connect the IC electrically io terminals leading ouiside-thc package.
;hathe IClastic or ceramic casing
Although ihe Soviets employ wafer saws thaiused in the Wesl. at limes iheyrcenl through the wafer, even foradvanced chip-shallow cuis
used by theresult in greater fracturing when ihe ICs arc broken free,ignificani decrease in the number of usable devices. Less advanced Soviet devices havecuts ofercent or more Since tho oni> practical advancer of ihe shallowcuts is to piolong blade life, ihts practice suggests thai ihe Soviris experience Spot sltoi lages ol quality saw blade
r
wire bonding. lhc IC is conneciet! electto terminals leading outside the ICnalyst indicates thai ma
bonders curren.ijuie limil ihe performanceSoviet ICs assembled wiih indigenous Tjanalysis indicates,i td Western wire bonders providebond strength and shape for mosi Sovietdevices. Alihouglproblems in some advances ic?esio deviceWestern equipmeni now mocadequate to meet bondinrirV cats 'OrVLSI device:
Testing equipmeni is used throughout the ICprocess to measure critical dimensions and to assess electrical and functional characicitstics tobad circuits before time and money are investedbonding andhis is particularlyin the USSR where tlie failure rate of ICs
rulieiitut since. the Ria^ iMacmnv Uutniinc ana loot Plant has taken lhc lew) in theij yeAxuv-i^ ul autonijicil S(
L
high Some test* incmscltes have beenbecause of faulty test equipment orindicates thai improperly
adgusicu wj.ct test piobcs sometimes causedamage to Sonei
Once packaged, military-use ICs are subjected to rigorous lesiing to identify pans that would fait soon after first use and to senfy that an IC works properly ai its intended operating speed. Soviet scientists claim that one-of ihe most acute problems confronting the Soviet microelectronics industry is the lack ofadequate to test LSI and VLSI devices (sechey allege that such equipmeni can be obu-irjc1 *irly ('om Japan or the United States
Clean moms arc specially designed areas for wafci-proccssing opciaiions thai have temperature, humid iiy. and dust control systems As IO become more
r
Figure" 14
Clean Room Classifications
/'orlii/i'iir lilulul Ui" ICOOW
lOO
it
> 20
nit
fm
0
and device geometries shrink, stringent clean room environmental control becomes increasinglyio achieving high product quality and reliability, foringle bacteriumnicron circuii line would be equivalentarge treeoadicron,article the size ofa flu viruscan disrupt the operationhip
Clean rooms in the microelectronic* industryin five standard categories.:ndefer to the manmum number of particles ofsite or laiger per cubic foot ofaferclean rooms mustt-isi al Ihe class lOOka-el farSoviet
IC planis have cuss iuvncUSSR. microelectronics planis typically operate dean rooms at theor above The lack of adequate dean room facilities has kmg hindered ibe USSR's ability to produce ICs ai yield rales comparable to those achieved in the Wcsi Over ihe years, analysis of Soviet devices has ahown high levels of deviceand moisture damage from poor control of the clean room environment"
To improve ihetr clean room technology, the Soviet* need to develop or acquire high efficiency paniculate air filters and the know-how required to use them in an overall clean room layout. Beyond air fillers and clean room design, the Sovietseh-.cn controls on particulate contamination from incoming gases and processed liquids and from human operators Humans shed an enormous number of mKroscetpiv particulates and have been proved in US studies to be by far the greatest pollutant of IC fabrication areas.
Past tfforts To Kcequip the Production Base
The Soviets haveombination ofdomestic RAD and production programs, cooperative efforts wilhtn CEMA. and acquisition of We-iiein manuracturiRgiccquip 'ustr; to support production of advanced ICS
Domestic Equipment Industry
staledioduciion taaUpMtM iinajjuscH and manufacturers are not up to the task of the acccler aied development of the Soviet microelectronicsgg the proposed rates of modernization He noics lhat ihe USSK produces only abouiercent cl the volume olanufacturing equipmeni in ing'V'esi.f^
Jtnat tne leciinicai
uatton ratios) tor the Production of Scientific In struments tn Chernogolovka cannot produce enough advanced deposition equipment to meet all orders, and poor packaging and handling procedures at theRadio Technical Plant have rcsulicd in the damage oft/ttfM ofD equipment shipped to consumer
The Sovsci equipment production base isart, because IC producers do not retool often, thus limiting the demand for more and better eouipment Reporting indicates that the Soviets expeci theiro operate for aboui seven years, and typically itervKC much longer than this
projectedextensive downtime and degraded performance. In contrast. USproducers generally replaceercent of their inanufaciuiing equipmeni every three io fivetime thev initiate productionew generation of device:
Sluggish retooling schedules icftcct, ai least in part, an overriding priority on ihe part of IC producers tolate quantitative production plans ai theof qualitative goals for more reliable and more sophisticated devicesS the Soviets attempted in correct this situation byecree that would allow plantsecrease production quotas in compensation for time losi in retooling. There is little evidence thai this decree has yet fostered much industrial retooling, but. if implemented, it could counteract industrywide preoccupation wuh meeting current produclion Schedules and encourage factory managers innovation over maintaining the status qui
Bureaucratic problems have also thwarted theand modernization of the microeleci ionicsProduclion targets assigned the MFP have been overwhelming and unrealistic Major elements of Gorbachev's industrial modernisation program arc intrinsicallyndustry is being forced to do everything at once retool, increase, qualm,resources.product inn. and accelerate in eductionoherent, workable plan,has been slo*
In summary.odernization program has yet toajor impact on the Sovietindustry, which entered wiih many of the samead when Gorbachev came to
* [tic"niucVrnijdii.i'i tu. often
Wrserra otncivnt ,i,mtnlljt->ani policy imiiiwied bjor ilninttti'<coi-onm
.Si Goib.ichi-ittcr lhc icrni lijitiiimcdj tvI>i%jvidr tht
ul pljnt >ntt iMU'iuncei Baiiealh. it imukoluduenic cj^iCittihc itriii.it> wee ul iiuftiaaclariat iics-*tJ>ac> "im;v, *.
roductivity, poor-quality ma-chincrv, and an organizational structure unprcpaicd for economic reform:
Gorbachev's "human factor"iscipline, icmpcrance, and improved workintended to raise labor productivity forh Five-Year Plan (FYP) while industry rclooled.discipline helped boostut by7 Gorbachev complained thaihad been last
Despite mine investment over the course of the current FYP, ihc Soviets have fallen far short of their plan lo bring new capacity on stream and to replace obsolete manufacturing equipment.
i
- Soviet measures to introduce self-financing and other economic reforms to increase operating anion omy have caused plant officials lo flounder.by contradictory directives from above, mam have struggled to blc Suppliers and to meci Contract obligations
CEMA Cooperative Efloris
ecade, the Soviets have pursuedwiih the East European member countries of CEMA to augment indigenous microelectronicsand io acquire Wcsiernhey have set up an elaborate division of labor within CEMA io helpnified basis of (Cmicroelectronics production equipmeni, and semiconductor materials As pari of this effort.hasumber of multilateral andcooperative efforts to coordinate Ihe development, produciion. and tradewrVtr.itonics production equipmeni within the Rio
In the, the Soviets initialed the Micio-electronics Elemcniultilateral proerjm with ihc avowed goal of increasing and modernizing
CEMA-wide produclion of microt Ice ironies devices for computer application! The participants believed, however, ihai ihe program's underlying purpose was to match Ihe US Department o( Defense's Very-High-Speed Integrated Circuit (VHSlQ Progiam. Milestones and goals for Ihe MicroelectronicsBaser" ave been comparable to those openly published lor the US program, namely to produce ICs embodying advanced VLSI technology to meet piimariiy ihc high-speed signal processing needs of nest-ecneralion defense systems To support pio-duciion of ihese advanced devices, the USSRatalog of microelectronics manufacturing equipment requirements to all CEMA participaiiis. usingas reference Systems,
5 lhc Soviets initiated another major CEMA cooperation effort, known as the Comprehensivefor Scientific and Technical Proves* io ihe0. This progiam was designed to servelueprinl for accelerating iheand diffusion or advanced technologies- -intlud ing;he Sovtei Bloc An ultimate goal of lhco reduce Bloc dependence on ihe Wcsi and io increase the region's immunity from Western embargoes and boycotts The Committee on Cooperation in Electronical ion is to coordinate the electronics rclaieC agreements and goals thai are pertinent to the0 piogram. By8 this program coveredgreements among the member coun-iric
Wc know little aboin CEMA progress in meeting multilateral program goals bmdoubl that Iheseeffons have contributed much to iheof Soviet state of ihc an in microelectronics manufacluring equipmeni The programs, are offlow start, and Moscow has complainedack of tangible results
opej'i COu Pint) ol CfMA include flulfjr.i.
(.'oxlHisiooksi. fiasi Germany.nlamlBiyn-mu
^Se*re
addition io lhc many multilateral programs Ihc Sovietsnitialed within CEMA. lhc Soviets inaveateral cooperaiiic devel opnvent and iradc accords wilh us East European CEMA allies. In fact. Mcncow has signed bilateral agreements, similar in form and content to the0 program.economic relationseach of Its CEMA allies ihioegh the beg innin; of lhc next ceniuiy Many o' these bilateralhave included specialization in the development and production of IC fabrication equipmeni (see table!
Among the CEMA couniiies. the USSR Can gain mosi through cooperation with Easi Germany. Ihe East German combine Carl Zeiss Jena is Eastern Europe's leading producer of microelectronicsequipment and is renowned -withinor iis lines of maskmaking and phoioliihoguphy equipment Ii ships much of iis equipmeni ouipul toSRi. 'Carl Zeissodel Combmej
in teiss alleges dial us equip linn, is within two to ihrec years or Western siaic of ihc an. wc assess ihai the combine's equipmeni is ttill substantially less reliable than Weslern counter par is and cannot su^pon sc-ics production ofVLSI devices. Kjs;nability to nice: even us Own needs for advanced IC ma nu farm ring equipment is proved out bv its heavy reliance on Wcsicrn equipment.
r
verrtiiiny na>
crnergco asamwiu;iui .cadet in ICihc Warsaw Pact. Acquisition
equipment was critical to Easi Germany's success8 in initialing produciion of second generation VLSI devices Although this equipmeni most likely will remain in Easi German plants, (he Soviets through Easi Germany mav nam access to VLSI manufaciuring technology
Through (heir relationship wilh Bulgaria, the Soviels have hastened produciion of indigenously designed IC manufacturing equipmeni The Siberian Branch of lhc Soviet Academy of Sciences designed ihcpitaxy system bul was unableindle MEP inlcresi in manufaciuring ihe machine in ihe USSR. The Siberian Branch was able ioicensing agreement with ihc Bulgarians, however, and viewed this cooperative effort as ihc quickestntroducing ihis advanced technology io industry This Sovici-Bulgarian effort has led io the establish men)oint scientific and engineering Cemet to fosicr dr-vi-lorvrscni of other manufaciuring
CEMA cooperation and specialization programs have improved technical capability wuhin lhc Bloc,duplication of effort in equipmeni development increased Ihe level ol circuit standardization, and allowed the Soviets to bcuer manage the legal and illegal acquisition of Wesiem production equipmeni In addition, by increasing ihe level of science and technologyi cooperation with Easternhe USSR has ihe potential lo fosicr greater poliiical and economic interdependence among the CEMA countries, conseivc scarce hard Currency Supplies lessen dependence on ihe Wesl. tap into pockets of technological expertise thai exist ir. Eastern Europe, and concentrate On more advancedn rrany instances, however. CEMA cooperation has Seen forcedca-slumo ed USSR thai has aroused the resentment ol .ticuiopean countrie*
Acquisition of Equipment From ihe Wesl To compensate for iheirindustry', inability to produce high-quality microelectronics manufaciuring equipment in volume, and then inability to salts Is this
(ail 'ieiiiodel Combine
German leode'S lendingle nui ihe Kombinaiarl Zeiss Jena (CZJ) as ihe model industrial tomhinc Looted and completely destroyed by the Ned Arm, immediately after World War II. CZJ rrosrembled and strengthened illndprogramsecome one of ihe largest and most technologically advanced enterprises in the country The combine, headquartertd tn Jena and subordinate to the Ministry of Electrical Engineering andnow employs0 employees atubordinate enterprises
The combine is recognizedorld leader in optics technology and its manufacturing rangetends toglass, locable, io cameras for remote sensing CZJ has become more active tn the microelectronics field in rexetr years, and microelectronics fabricationis one of lis mrwettpeoduct lines
he US tmouegv on in*v, aahe Soviet Bloc forced the combine lo develop ond manufacture its own line of machinery The combine is now the principal suppliertam lithography tysttms in the Bloc andide range of microelectronics equipment.
including CAl> sysitms. optica! lithographyphotomask comparators and inspectionresist coating and developing equipment,etching systems, chemical vaporevaporation and sputteringbonders, and IC testing
tquipmtn:
CZJproductsootict equipment annually
Aifi^'ii approximut-iy an eenr-ii ctf mequipment ouipul to other CEMAtheZeisl wt"
the process of equipping teverai .soviei ICplants and emphasized the USSR's dependence on the comtnne for supply of critical equipment Theemand for advanced equipment, hc-oer. may be met at the expense of East German domestic requirements Foe example. Zeiss'i Uthctgropkic-rt-toted products are given priority over optical rnsi'u-memation products badly needed by Las: German tab:
through CEMA cooperative efforls, thehaveajor cffoit io acquire Western machinery lor reverse-engineering purposes and for diiect use in iheii own planis The USSRtempts lo reverse engineer ihc first sample ofequipmeni ir acquires The Sovseis have been particularly successful ia adapting proven Western designs and incrjrporaiing ihe adaptations into Tucro-fproduciion lires (_
^jrovici Copies seldom, if ever, approach the^ualily and productiviiy of (he Western originals
Because of time delays andevene-engincenng Western equipmeni. the USSR ofien uses large numbers of illegally acquired Westernequipment to outfit us mosi advanced IC produciion lines This equipmeni otter is not used lo its full poteniial. bul it noerthcless ts rnore productive than Soviet produced equipment Analyse indicates thai since the, ihe Soviets have acquiredieces of Western microelectronicsequipment, covering ihc entire spectrum ofoperations. They have acquired most of ihis equipmeni through Wesl European divcriers. bui
Means and Methods af Equipmeni Acquisition
Sovielsariety of techniques for acquiring Western IC manufacturing equipmeni The Soviet Military Industrial Commission <VPK) of theol the Council of Ministers is responsible for selling acquisition pncriliei for oneindequipment that ts often used for reverse engineer ing Soviet mpies The VPK processes requirements from the various equipmeni design bureaus, validates the requirements,ollection priority to each, and designalet collection tasksne or more organizations These equipmeni collectors include the Soviet Commiiiee for State Security IKGBJ. Chief Inielligrnte Directorate of ihe Soviet Central Staff tGRlft. Ministry af Foreign Economic Relations ipre-nomslr known ai ihr Ministry af Foreign Trodn. Siaie Committee for Science and Technology. State Committee for Foreign Economic Relations.of Sciences and the East European intelligence services We animate that the collectors satisfy about ont-thtrd of VPK-itsurd requirements each year
The Soviets have dealt primarily with Westdive't'T,
Ministry of Foreign Economic Relationsthe Soviet program to acquire, legally and illegally, production equipmeni in large volume for direct use The mimury administers and operates hundreds of foreign trade organizations and firms around ihe world This global presence and thefficial duiieiractical cover organization for hundreds of KGB U officers involved in technology acquisition
The Ministry of Foreign Economic Relations keys iis acquisition effortsequirements issued by the various microelectronics manufacturingOner it approvei and prioritises collection requirements, ihe mimsiry arranges for Western con-iraci trade dtveners to work Soviei foreign irade firms lo organne large-scale acquisitions ofequipment The Soviets engageare than JOheir diversion schemes
lost equipment
Although the St/viels hone arrongi diversions through'1
The nonindustrialtied countries have servedas conduils for the transfer to the Soviet Bloc of microelectronics lechnologv and equipment illegally acquired from itdwsirielized countries. Countries such as Brazil Soulh Korra. and India potentially can provide the Soviet Bloc wtth much needrdand would be attractive acquisition targets because iff less stringent export control regulations
Seatet
an illicit program io acquire embargoed equipment. Total known acquisitions of majormiciodectronits manufacturinger year?elieve that the actual number was higher
Since theighter tradein Ihe areas of nicroeJcciionics andcombinedeftnemeot of ibe Soviets' acquisition effort for mnorJectrcrarci manufacturing equipmeni has resultedO percent drop in the overall equipmeni acquisition rate (seefcerate of known acquisitions feller year to aboul ISO per year at presenC.
Dunng this time frame, the Sovieu focused their efforts on obtaining fewer yet more advanced and productive machines, concentrated in areas ofweakness Analysis indicates thai the Soviets haveuch lower acquisition rate for some equipment types: tlte rare has fallen almostercent for material preparation equipmeni and about SO perceni for doping and packaging equipment. They haveigh acquisition rale for oxidation, lithography, and etching equipment and are placing en increasing priority on the acquisitionsters.
These acquisition trends are consistent wiih ourof Soviet prugresi in overcomingdehcteocses Although the Sovieu still havewith material preparation, doping,these pr-ttors lessened inIn
lnng, and automatic testwhere they have maintained high acquisition rates Soviet efforts to obtain wafer probes and advanced IC testers have been especially rigorous in recent years, and the Soviets have often been willingay twice Ihe lisi price for Western models
Figure IS
Average Soviei Acquisition Rate of Microelectronics Production Fquipmeul
AtGviVliQfi Hrtt pt* |rui-
'Cedecuon of Infemmwri on So-set microckci tonics production equipment acquisitions through wchnk'il means abruptly droppedaciorB srwlOur numbers9 nrOrti jn off letting coinpcrrvaiion for thisrocessing capability, and. an cairapoiaiwn fot the remiiridei of ihe yrir based on the firstmonths of rcponinj
Much of lhc sophistics led equipment acquired by ihe Soviets for VLSI production, however, requires more stringent environmental controls than most of the Soviet plants can maintain to operate the equipment at maximum efficiency and to achieve acceptable IC
yield ma To complement iheir equipmentprogiam. ihe Soviets ue also seeking advanced clean loom facilities fiom Western hints loKM nici advanced plant-
Wiihoui ihcu mayor cqaipmeoi acquisition effort ihc Soviets almoM certainlylag further behind (he Weal in both IC quality aad IC production quantity We eslimate thai, wiihoui ihc aequmiion of Western equipmeni foiseoe use in developing equipmeni models, lhc Soviets mighi not have been .iblc to supply adequately up to tO peicem of iheir current oioduciiQii lines (or SSI and MSI devices
ihis Western equipment
- r. ii i
nd icchnolocy. ihe rje devices might have cni of currentn acquisitionsi rjm Wiihoui Wcsicin use as models,ive been unable 10
o supplec Soviets ha<
..li : ii. ii. suppls up toctcciil ol ihc if cu'fcni production lines for ihese dciccs and thai their production yields :iiigln have dropped by as mucherceni of siclilsathiC'ed.'
equipment acquisition clTorts. kruCiiplore iowi ventures wn cpiuiy sysiemlaims is available lor cipoet. and hasarincrsfup agreement wuh the UK ham Vacuum Generators. Lid io develop0 advanced rneia shia lion and lithography syv lens. STC reporiedfy isorming jotnt-dc'itocu-ieni and marketing ventu'es for advanced iiisirumenis with US firms
Ir, lisie Soviets formed ihe lomi'vcmuieInterqundro with French and liahan firms will use Soviei
and French hardware lo develop andturnkey *orkstal>cws for applications suchand electronics testing and debs.gg.ftf.user iraining. and io serviceercent
qf the initial capitaon. and profiis are to be shared proporironaicly wuh ihe Western partners
9 hvttttyo article disclosed ihat lhc Soviets ateoinifor ihe production ol an indigenously designed cpiiass system with firms in ibe United Kingdom. Lu>rnibv'f. Fianceden Tbe aitick describedm* tec star-beam cpiiaay machineigh-quality IC processing device "equal to prevailing world sian dard>'
equipmenie iini.ni. mi or mil Hon mm-caies. however, ihat lew o( ihese aucmpis at joint ventures in microelectronic* have jelled Moreover, the agreements lhal hive been Concluded arc still in the early stages and have yei toayor contribution lo meeting produciion needs
. in an milial eflori io cooperate actively and legally -ii.'i Western firms in the electronics field, the USSR formed lhc Science leehroaogy Corpora-imn fSTO to design, maoufacture. and maikci high-tec hisology instruments this Leningrad-based organization reportedly is governed under relaied bureaucratic rules governing foreign trade and hard currency STC has developed *
lnmo in HI Inwlli^lab
gW KAIIM.
. ImfMI it/lti*iUitirti I
ilerion Requirements Inr
The Soviets* relatively antiquated IC production bave will br stressed even further by growing demands for advanced ICs from both tbc miliury and civilian sectors (see appends* A) To produce high-qualny. advanced devices io meet future requirements, the Soviets will have to incicase IC ywkj rates and improve manufacturing practices for VLSI devices Ihis means ihey mustarge percentage ol iheir IC produciton lines with advanced equipment
The lack of information on equipmeni inventory and uiih?anon ol microelecironics plants precludesof the Soviets" equipment shortfall inproduction equipment and makes itio eslimate requirements foi equipmeni lo
support future modernization efforts. In nn efforlauge potential inveslmenl requirements for needed equipmeni, however, wc looked ai past Soviei cITons
Western manufacturing equipmeni.which waj put io use in advanced Sovieilines. Analysis indicates thai ihcpieces of equipment ihe Soviets are knownacquired from the Wesi since the carlsbe sufficientutfitlines like ihose used in the Wesithat Ihe Soviets have illicitlymount of Wesi-""
judge inai m* io<aiof V.qiii>imcnt acquired by ihc Soviets could Outfit as many as, but probably not more than.C produclionone-third of their production capacity'1
We think it is reasonable io assume that requirements Tor VLSI produciion willimilareffort Analysis
3
ndicates ihaiSoVusKMv&ickai'flO. and more. microelectronics production plants. Although we do noi know wiih certainly how many of these planis are involved in ihe seriesof integrated circuits, for the purposes ol this paper wc assume that ihc Soviets haveCplains If these plants are out fit ledanner similar to US plants, wc estimate that the Soviets haveC produciion lines II wc assume lhal the Soviels choose lo retool one iliird of ihose lines for VLSIc eslimate thai they could need the following types and numbers of IC processing equipment:
O projection lithography systems.
H$ photoresist processing tracks
lasma etching systems.
xidation and diffusion furnaces.
On implanlers.
afer scrubbers.
pitaxial systems.
etallization Systems
" In in effort to produce ihe adorned ICs necessary foe modern miliiary ind industrial systems. Ilie USSR will encounter Use time nrufems faced by Easi Germany a* ilits<ons:>tci>i> beyond ill production capability. The remit ofiii
Ceni'itiy has hecn IO illi">itonew jd'inccd6.1
low9f1 -On Id be loitvd lo dooie jof USilvjwcit IC labnCiliOfl
Brute foreini ihe
We estimate thai ihis processing equipment alone would cost betweenillion8 billion if purchased openly on the Western market. This is close to the amount wc estimate die Soviets have speni on their microelectronics equipment acquisition clfori since thecquiring VLSI icsicrs for advanced IC produclion lines would add substantially to the above estimate as each lypically costs over SI million. In addition io investor advanced IC lines, lhc Sovicis probably also face substantialrequirements to improve ihc production yields and reliability levels of standard, commercial devices, and io raise their average level of IC manufacturing technology mat Icasi ihc LSI level
Sonet Options for Reequipping Ihe Microelccironies Industry
The options available in the Soviets for retooling iheir microelectronics industry for advanced VLSIarc ihe same as those pursued in ihe past:
Accelerating indigenous developmenl andof manufacturing equipment.
Maintaining research and production elToris within CEMA
Increasing acquisition of Western equipment cither directly or by transfer through joint ventures with Wcsiern comnanic
Accelerating LSonn-sni Produciioo
The ideal solulion from ihc Soviets' perspective es to revitalize domestic produciion capabilities Aprogram to design and build IC manufaciuring equipment would reduce dependency on foreignincrease the Soviet technological knowledge base, and improve the mnioelecuon.es industry's ability to respond to Soviet military and industrial requirement!
Gorbachev's progiam to modernize ihe Sovieiinitiativesonlrol and increase decisionmaking authority at Ihe enterpriseno doubt will have some positive effects on ihe microelectronicsequipmeni industry The quality and technology
Ii-vd ofS'wiri micoelcctronics eguipmcni will suielv improve, especially in ihr* areas of crystal growth, wakr preparation, and IC assembly, but not as quickly as will Western equipment The Soviets, however, arc likely to continueall well short in areas such as CADJilhography. wafer processing, and IC testing
In the final analysis, improving the technology level of the microelectronics industry, like otherindustries, depends on the Success of Gorbachev's reform program. Gorbachev's program is unlikely, in the near term, to create conditions along the linescsicrn-stylc market system that will encourage enterprises to respond quickly and routinely tofor new production machineryesult, we believe that Soviet leading-edge productionprobably will continue to lag that of the Wcsi by one to two IC generations and that the Soviets, in, will continue to rely on outside sources for much of ihe equipment required for producingICs
Maintaining Pressure Within CEMA The Soviets will continue to look to CEMAto supplement indigenous equipment design and production efforts and their program lo acquiretechnology The recent success of the Eastin acquiring Japanese turnkey IC production lines, and iheir resulting success in achieving pilot production ofS1 devices,the iypc of access to East European and Western technology the Soviets hope to acquire through iheir CEMA relationship
The Soviets, however, probably will encounterresistance from East European countries. Most of the East European countries have gone alongand selectively, with Soviet-initiatedproposals to placate Moscow andnsure deliveries of Soviet raw materials. Soviet efforts toooperation in microelectronics will probably be most well received by Bulgaria andthai have linked their economics closely to Soviet development and stand to gain the most from increased contact and cooperation Roma-ma and Czechoslovakia,fear losingand arc less enthusiastic about participating. Ejsi
Geimanv and Hungary could nnd new Sovieta threat to iheir independence, an encroachment on their proprietary innovations,eterrent to trading flpportunities wilh the West
As revealed at the CEMA Executive Committee meeting inany East European countries are uncomfortable with the fast pace of Soviet-inspired initiatives to instil utionalire planningthrough CEMA Even Czechoslovakia, which bas been an active supporter of many Soviet-led CF.MA integration initiatives, noted the "complexity" of reconciling numerous long-range regional plans with national interestsime when most CEMA countries are drawing up their own long-rangeeconomic plans and ace altempttngestructure Iheir economies In the future, many of the CEMA countries may be increasingly reluctant to surrender control of domestic high-technology programs to the Soviets or lo commit resources to projects lhat would in the end benefit primarily the USSR. To the extent that the Soviet economic reform movement spreads to Eastern Europe, the Soviets could find it increasingly difficultobilize CEMA to support Sovietmodernization effort
Continued Dependence on Ihe Wen Allhough the Soviets originally consideredtechnology acquisition tohon-ierm fix to overcoming their technological lag with the Wesl. the stifling effect this course has had on the development of their domestic industry has hampered their ability to narrow the gap with the West over the long term For example, our analysis shows that the Soviets progressed to Ihe levelRAM production fairly easilyombination of indigenous know-how and Western technology and equipment AtK-DRAM level, however, they experienceddifficulty in assimilating technologyas evidenced by lengthened devicetimes and delayed production timetables We believe that the root of this difficulty can be traced to ihe Soviets' heavy reliance on Western technology. Byollower strategy, the Soviets have failed lo acquire an extensive knowledge base of theof eiihcr ICs Or microelectronics fabrication equipmcn
SfeefC'
leaders seem increasingly concerned about the dangers of excessive reliance on Western sources for high technology because of the correspondingof domestic initiative and the creationuilt-in lag in domestic technology. These effects ate troublingeadership that is trying toector as the driving force to improve the economyhole. Ath Party Congress held inouncil of Ministers. Ryzhkov warned Soviet industrial ministers that Ihe parly would hold them accountable for their "eager" pursuit of foreign equipment that could be developed domestically While not ruling out the importation of technology. Ryzhkov called on Soviet industry to rely princioallv nn ihe "vastpotential" of ihe USSR
Despite public pronouncements about lhc need to rely on indigenous capabilities, the Soviets will have io coniinue relying on the West to acquire advanced manufacturing machinery to reequip theirindustry. Figureummarizes the technical capability of the various categories of manufacturing equipment now in use in Soviet microelectronics planu and helps identify likely acquisition targets. The Sovieu probably will concentrate on US and Japanese producers to fill their most criticalgaps, including CAD. lithography, waferand IC icsting equipment
Prcsidcni Bush announced in9 that the United States will lift iu "no exceptions'" policy in COCOM Allhough the Gorbachev leadershipviews this announcement as an indication lhat ihe USSR will have greater access to controlled Western microelectronics equipment, we will not be able to determine the policy's potential impact on Soviei microelecironics capabilities until it has been fully implemented Meanwhile, lhc Soviets will continue to exploit any weakness in Western export controls, as well as policy differences among member countries of COCOM, to acquire equipment necessary to produce microelectronics devices required for miliiaiy and civilian programs fornd beyond
ddition, the Soviets probably will push hard to form Joint ventures with Western companies for the development and production of microelectronics
Figure 16
Microeleci ronics Manufacturing Equipmeni Limiting Factors for Full-Volume Produclion
nuntamprntMl
StUain
jfci-
wim cr-lx"
Compute'Afclnl
OprKal fi*ncm
glWiinui
WildPifUfa Banden
lo-we
ur>u< probe IC
9U V
IM
oom fquipmcnl
IVgl IS 90 'SSK
equipment. Wc do not yei know the extent to which the Sovieu will use |oint-venturc agreementsas of acquiring Western production equipmentinimum, such arrangements will provide them the Opportunity to acquire pioduciion knowledge thai might otherwise be unavailable io ihem *"
Needs
Soviet demand for microelectronics devices has been dnven primarilymiliiarv requirements On ibe basil of oui analysis of the number ofystems probably using ICs. we estimate thai prodix lion intended for mililary use rsillion ICs annually, or aboul onr-thud of Soviet produclion of all lypcs of ICs
Historically, ihe mililary has been ihe priorityof microeleci ionics devices. The mililarydemands and receives Ihe highest qualilySoviet produclion lines. We do not expect this
(all Soviet mihtarjpercenttesting Devices that oo not pass military inspection standards are downgradedommercial or capon use or are discarded Chips selected lor military application are submitted to electrical,mechanical, vibration, heat. cold, humidity, and test-nance testing well beyond civilian Standards
Themilitary has long reliedinvested Injnlysuperiorityffset ihe West's technological advantage The Soviets, however, are now manufacturing advancedmaller quantities and are shilling from veil provenore advanced technologies and from simple to moreweapon designs to improve weapon performance and to irtcrxporate greater multirrmv.on capabilities. Virtually all of these weapon systems0 provide their expanded capability
Weidentified about JO Soviet military systems thai will be likelyequire second geneiaiton VLSI devices fihat is.egabit DRAMsj when they aic deployed by the0 This represents slightly less lhan one-thin! of the sysiems wc expeci the Sovietsield ai ihai timeion VLSI technology, which per inn* faster data anil signal processing, is needed in complex sysiems that
must analyze large amounts of data quickly and accurately. Among its likely weapon systemsare satellite navigation fnr submarines,radars, fire-and-forget missiles, passive sensors, terrain-following radars, and compactfor space-limiled applications
Development of second-generation VLSI devicesbe necessary il the Soviets are to achieve theimprovements and capabilities neededounier ihe next generation of US weapon sysiems This does not mean, however, lhai the Soviets will abandon planned sysiems if they lack the specified level of microelectronics technology The Soviets hasc often deployed systems with degraded performance capabilities because of technology deficiencies in Vies subsystems. For example, the Soviets have proceeded wiih production ofide-body civilian trans-pan, even though il has limited range, because lhc high-bypass lurbofan engines required for efficient operation had noi been successfully developed by ihe timeeached Scries production Moreover, theecame operational3ess capable lookdown/shooidown radai thanlanned. The key factor governing weapon system development decisions is whether the system contnfc utes to meeting mission goals. If the system fulfills mission requirements, it almost certainly will be pin-duced. even if optimal or intended performancere noi met
Prime examples of future Soviet weapons systems likely to require second-generation VLSI technology to achieve planned performance include:
Stealth bomber Second-generalion VLSI devices are necessary for sensing systems that rely on passive data acquisition (such as infraied sensors) or on deception (suchow probability of intercept, frequency-hoppings well as flight control computes for the Stealth atrCiaft
S
Scjs*
air superioritytealth fighter requires nil only passive surveillance seniors bul also weapon sensors thai will not give away iis position. The seeker system for an advancedair-to-air missile will probably require second-Rcncraiion VLSI devices.
ollow-on helicopter-launchedmissile The key performance objective of ihis system is torue lire-and-forgct capability Ihat would greatly enhance the survivability of the launch platform An eleciro-optical seeker on Ihe missileeans of acquiringapability. This seeker would probably requiie second-geneVLSI devices
Nuclear-powered strike cruiser. The signalof an improved naval surface-to-air missile will probably require second-generalion VLSI devices.
Carrier with conventional takeoff and landingThe earner's fire control and early warning radars, needed Tor an improved surface-to-atrsyslem. will probably require second-generation VLSI devices
Demands for devices required for ihe development and production of advanced weapon systems,with growing consumer demands and ambitious industrial modernization goals will surely stressVLSI production capability
Civil Needs
Industrial applications account for aboui iwo-thirds of annual Soviet IC output, orillion devices. Most of these ICs aie directed to dual military-civilian industrial applications. Soviei use of ICs for what ihe Wesi would consider Hue civilianas educational computers (see inset. "The Soviei Computerizationeme appliances, and(mall
Because ihe USSR's efforts to develop iisindustry have been driven largely by military concerns, historically ii has been difficult for Soviet
The Soviet Compnteriiation Drive
Duringh Flve-Year Plan. Moscow plans to introduce computers throughout the Soviet economy The plan colli for production of computer equipment to grow hyercent annually0ereem increase over the five years To support this compuieriionon drive, the Soviets planned tomicroelectronics -based technologies subston tially during this five-year period
The Soviets, however, have had difficulty supplying enough advanced, high-quality ICs to support this vasthkabardnya. Minister ofMaking. Automation Equipment, and Control Systems, stated atS Central CommuterBuilding Meeting that the USSRpecific shortage of to million ICs needed to support planned computer production This shortage of ICs may have had particular impact on the Soviets' ability to meet goals for producing personal computers (PCI
The USSR has an ambitious, publicly staled goal ofillion PCs by the end0 to meet demand primarily within its civilian sector o noi believe that the Soviets will be able to produce even hall that amount, in part because of ICOn average. PCs require what amount to Soviet state-of-the-art ICs suchbit nucroproets-sorsRAMs. and the Sonets appear lu have had difficulty supplying their PC programs with an adequate supply of needed devices For example, they have complained about the low reliability of ICs provided for use in PC production and have reported lhal ihey have been unable lo meet produclion goals for some models of school computers because of severe IC shortages
IC producers io ensure adequate deliveries o'devices for commercial and civilianapplications. For
-1
pri-
ority for acquisition of advanced ICs has limited their
availability (or use ia nueiear power planu. Following iccidcnu at the Sverdlovsk and Zaporozhyepecial commission reponcdly recommended4 thit military grade ICs be supplied to nuclear power planu This recomrnendalion, howcrer. was turned down because of eipense and una vai la billy of pans.
he failure of tbe compuier-ireo control system at the Criernobyl' Nuclear Power Plant6 was caused by poor-quality micioelcc-ironic devices, and believes that this accidenthas since forced the Sovieu to adopt_thc use of military-guide ICs in these plan:.
c
hovieuproblems in obiaminf electronicto produce new and improvedirnstry of the Electronics Indus
iry. whichirtual monopoly on the production of specialized ICs and other cornponcnu ol automation equipment, falls far short of meeting component requirements fot the machine-bui Id inc complcihole Consequently, (tie Soviets may be lotccd to chance historical prioritization schemes to meet trow-iiyj IC demands foi consumer goods and advanced production cquipmen
In the West, ad-aaccd ICs. especiallyarc criiteat components Us modern factory auto malicof computer numcricatty control led machine toots, robou. minicomputers, and micrrtcomputcrs. Thelan calls for Soviei industry to increaseof factory automation systems byercent.
he Sovieu plan lo ineorporateor electronic controls in one-third ofercent!
The biggest problem the Soviets face in producing high-accuracy machine loots is Iheir inability tomieroprocessors comparable to those used in Western models. Western importers of Soviettools typically remove lhc original electronic controls and replace them with high-quality, more reliable Western control devices We believewith certain ciccp'icni- So*>et industrial controlare approairnatdy five years behind thosein the West Most of the Sovieu' controllersil ir.tcroproccssors and ibcit most recent uniu arc basedbst mtcreprccnsori By contrast,bil microprocessor is becoming tbe building block for the West's computet-automated manufacturingincreasing ihe integration of the microprocessor contiol incieases the speed and tlte flexibility uf operation Ii is clear lhat Soviei pioduciion of LSI ot VLSI devices will be critical to the success of Soviet programs io produce and use advancedsystems
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Appendix C
MicroclccIronies Produclion: Sand lo Circuits
Crystal Growth
basic material Tor almost all microelectronics devices is silicon One of (be most abundant materials on earth, silicon is found primarily in lhc form of silicon dioxide, orefore il can be used for microclcc ironies applications il must first befrom the oxygen and purified of all oilier con)ami nam;
Mcullcrtical-grade silicon is produced by smelling quartz-bearing rock in an electric arc furnace using petroleum coke (carbon) as ihe rcaciam. Electric smelting can produce silicon that is up toerceni pure. Tbe metallurgical'grade silicon is then dissolved in hydrochloric acid, and the icsulting liquid isdistilled toure siliconusually trichlorosilaneide variety of other silicon-bearing compounds
T rich lor osi lane is ihe standard feedstock for theof elect ran ics-grade silicon. In the Siemens process. irKhiorosilaiw is vaporized, mned mihgas. and introducedell-sir reaction vessel containing an electrically heated filament As the reactionich lores'lane decomposes and deposits crystals ofercent pure silicon on all heated surfaces Tbe reaction continuesolid rod of silicon has formed around ihe nlamcni. This rod is composed of millions ofcrystals known as polycrysiallinc silicon
A final step is required to transform the intermediate polycrysiallinc silicon into finished monocrystalline silicon The bulk of the world's mooocrysiaUtrie silicon is produced by the Crocbralski method (otberinclude horizontal Bridgeman. liquKJ-ciscapsulai-ed Czochralski. and float zonel whereby chunks of polysilicon are meltedrystal pullerseed" of the desired crystal orientation into the melt and pulls it out slowly, allowing ihe molten silicon to solidify on the seed. Growth raie and
crystal size arc controlled by furnace temperature and pull rate. The precise electronic characteristics of each monocrystalline ingot, or boulc, arc noi only determined by the purity and quality of the polycrys-tallirte silicon used in its production, but also by the amount and type ofasthat arc dclibeiaiely introduced into the menr.
Wafer Preparation
The monocrystalline silicon ingoi is machinedrecise diameter with various flat sides thai mark the wafer crystal orientation The ingot is then sliced into thin wafers, usually by annular inside-diametersaws The saws may be open tedemiautomatic or fully automatic mode following the mounting of the boule and its rnacemeni for cutting After slicing, ihe wafers aie cleaned and then lapped to the desired thrckitess. usuallyouble-sided planetary unit that removes equal imounts offrom the top and bottom of the wafer at the same time. Finally, lhc wafers are chemically etched to remove some of the damage caused by lapping and are polished (usingingle-sided polisherouble-sidediomooth,Surface
Computet-Aided Design
An IC designeromputer-aided design (CAD] system to devise the electrical circuit desired and to translate lhat idealized electrical representationultilevel physical IC layout. CAD sysiems have virtually replaced manual drawing of circuitcs, whereby individual parts of ihe IC design were physically drawn many times ihe size of Ihe actual electrical part, and then photographically reduced for
photomask reproduction The tolerances and geome-irics used tn today's complci ICs make manual drawing virtually impossible. CAD systems arc mam times faster lhan hand drawing, are more accurate, and arc more reproducible in their results. Alter the circuit design has been completed, the CAD systemape thai can beither an optical pancrn generator, an fc-bcam maskmaking system,ircci-wiiiing system to translate tlie IC designorking circuit
Maskmaking and Lithography
Following circuit design, pattern generation is ihe sian of optical maskmaking or rciiclcmaking. An optical pattern generator is generally usedreate automatically the photomaskesigned circuit pattern The outputaster phoioplaic, usuallyX) larger lhan the final CirCuil Ebearn maskwriicrs arc preferred for the maskwnting process of complex IC designs with fine geometries because the process is accoenpljshed faster lhan wilh optical pattern genera lory.
Following pattern generaiion. the master phoioplaic is optically reduced and reproduced hundreds of timestep-and-repeat process toet of final-size master masks from which Ihe working masks arc made Step-and-repeat cameras are capable ofusable line widthsicron. Although optical Slcp-and-rcpcai cameras traditionally have been used to produce IX master or submasler plates for working prints, directly stepped working masks (drawn byeam process) may now be an economically viable application.
In translating the circuit design onto ihe wafer, an oxide layer is grown on the wafer surface using an oxidation furnace and thai oxide layer is coatedhemical layerhich is sensitive io (he radiation source to be usedlight and ultraviolet light (optical lithography or pholotiihogru-phyl, electronays, or ion beams.processingreferred to as trackscrubs, bakes, coais. andthe wafer and photoresist One level of ihc IC
design is then patterned onto lhc resist (deviceconsists ol anywhere from six0 rthoioliiho graphic steps) usingvariety ol increasinglyequipment Lithography rcprcscnis one of the highest cosl elements in producingproducts, and the choice of lithography systems and exposure toolselicate balance between cost, performance, and productivity
' aligners are the oldest andmask-to-wafcr pattern exposure machines. Contact exposure is capable of generaling minimum feature sizes of onlyicrons and can damage ihe mask and wafer. Proximity printing lessens the poteniial for mask and wafer damage, and tbe best proximity aligners are capable of producing feature sires at smallicrons. Top of ihe line coniact or proximiiyusing deepillumination sources are specified io achieveicron resolution Pegrsiraiwo problems, however, irtcrcasc al these imc widths, especially with larger wafer diameters Since the, proximity and contacttechniqueseneral, been replaced by optica! projectionicroelectronics fabrication
Scanning projeciion alignersX photomask containing ihe full wafer pattern and expose iihoiorcaist-coaled wafersweep or scan" of ihe illumination source lluough mirror optics. This equipment contributes to long musk life and is capable ofesolutionicron 1'hese aligners, however, arc relatively expensive, are sensitive to tempeialurc and vibrationand require frequent adjustments.
- Slipping protection aligners liirpprrs)egmentull wafer patternXor reduce ilX or SXa lens while 'stepping" across ihe wafer. The choice of available reduction ratios generallyrade-off between resolution and held sue and can beby throughput considerations This equipmeni
contributes to lung musk life and limits defects Ii is vciy expensive, however, and can be subject lo distortion and stepping errors Steppers withlaser tight, sources recently have been iniro duced that aie capable of submicron litlsoeraphy. and versionseveloprnent will probably be able to fabricate circuit lines as low asicron.
E-beam systems have Ihc resolution and alignment accuracy necessarychieve circuit dimensions downicron They can be used forand direct wafer writing The primary applies -Ikmseam direct wafer writing are small-volume production of custom ICs. quick turnaround of new designs, or achievement of submicronOne of ihe biggest advantages ofbeam system is its ability to faciliiate changesaltern to meet design and processing requirements readily Ihe biggest drawbacksbeam systems aie equipmeni expense, low throughpul. and proximil> effects."
X-ray aligners using synchrotrons as light sources have ihe potential for high throughput of submicron feature suesul researchers have yet to resolve mask fabrication problems US industry experts predictay aligners will be necessary for fabricatingmegabiidevices
Focused ion-beam systems, now in exploratorypotentially can be used lor direct-writing free of proximity effects Throughput wiih this system, however, will most likely behc use of focused ron beams in repair defects in lithograph ic masks and ICs and to prrfonn failure analysis, however, has moved rapidly from Reel) toapplicationi
r mure pattern tcuniciiiei aie exposed la raonniiiy, each (Cornell) willh" elniionn il Ii Mia rrmoir
Iran all ftrt madam Ttai*Haa' riiart.rrCaviei ihe
ca rcowtrirtpraaaurti iu be atone from naeawrd
"Hh standard opim' lii*ofay. and foevted ion bum lynems ollei lb* pmemul far pruUSieliii IC( wiib smillariiti Standard urKical issiemvare less expensive nn proms mare *afers per hour, and tuller fever operaiional proMemV
Aftci wich level of the IC is patterned onto Ilie wafer, cither Ihc exposed resist or ihc unexposed resist is washedon lhc type ofenabling aa fee-processing step lo be carried out on she desired portions of Ihe underlyinghe processing step, tbc remaining resist is washed away. This process is repealed until the entire circuit has been replicated onto the silicon wafer
Wafer Processing; Etching, Deposition, and Doping Etching
Etchingrocess in which patterned layers of lhc wafer surface icvcalcd during lithography are selec-iively removed Wet (acsd or chemical) etching is the older process chat is still used for relatively simple ICs with line widths greatericrons Wetran nol be used much below (his feature sue because of its tendency to etch tideways ai the same lime as it etches downward, causing the lines to spread and merge together
To overcome this drawback, dry (plasma) etching is used for advanced> etching systems are required lor processing ICs with feature sizesicrons aad under There are lour types of dry etching systems for thin him etching
Barrel systems are used foe photoresist Stripping and selective etching of polysilicon and siliconwiih circuii gcnniciriesicrons or greater
Ion Miffing systems 'been used to etch gold, platinum, and other materials Ihat arc unsuitable for cither chemical plasma etching or reactive ion etching.
Chemical plasma etching systems produce an isotropic etching profile similar to -et etching, since plasma chemistry is the dominanl etching
ositive rem! iSw pernio" of lhc resist ibai Hie bebl srntrs
is rcimweri.egaine if sin (he areasemain after deielocanew ftisiiive rtusii (fruity allow for crraimn of imallrr tenure sires
SecrW'
These high pressure machines process wafers oneime and thus have lowerthan batch processing machines.
ton etching sysiemstraight etching profile since the dominant etchingis ton bombardment These low-pressureprocess wafers in batches.
Each dry etching technique has differentof throughput, spread, and material selectivity Most systems in production use ate highly automated and do not place great reliance on the skill of the operator. Chemical plasma etching and reactive ion etching are by far the most popular dry etching methods, and current sysiems arc capable of etching lines down toicron in widthbeyond what curreni IC designs require
Deposition
Deposition of films onto the wafci surface can be divided into two categories, epitaxial and nonepitax-ial. Epitaxial growth is the more difficult of the two lo achieve because it requires ibe crystal Structure of ihe wafer to be continued through ihe deposited layer. There are three basic types of epitaxial deposition
Liquid-phase epitaxy (LPE) is the oldest technique, whereby films arc grown byafer above the surface of ihe melted element or compound that is to be deposited.
Vapor-phase epitaxy, which includes metal-organic chemical vapor deposition, uses vaporized chemicals to grow films on wafers. This process has, by and large, overtaken the LPE technique.
Molecular beam epitaxy (MBE) is the mostepitaxial technique MBE deposits films on heated wafcis under ultrahigh vacuum conditions. Film growth, while relatively slowicron perllows very accurate control of film thickness and doping profiles and produces atomic-ally abrupt interfaces. MBE has great utility for depositing exotic compoundi
Noncpiiaxial chemical vapor deposition (CVDJ nnd physical vapor deposition (PVD) are less demandingf> can be used io deposit manybut those generally deposited (other lhan ciMtaiial silicon! arc pot-crystalline silicon, silicon dtoastk.on aiirtdV
PVD is used to deposit thin layers of metals or silicidcs on the wafer to act as interconnects between individual circuits on each IC. The two methods of PVD arc cvapoiafion and sputieiing. Evaporation is the conventional method for meial deposition and is often chosen fot processes that icquire lowor high vacuum The major drawbacks ofare the difficulty in controlling alloy composi-tioa and the nonuniform coverage of steps on tbe wafer surface Evaporation has, in general, been replaced by sputtering in advanced applicationsis often the deposition method of choice be cause of its ability to produce high-quality filmsigh rate and at lower temperatures and pressure
Hoping
Doping is the controlled introduction of preciseof impurities, or dopants, inio specific portions of the wafer lo achieve desired electricalThe dopants norma liy used include boron,pbcnpSor js. and antimony
The conventional doping systemiffusion furnace that relies on beat to spread dopants steadily from the wafer surface into the depths of the wafer Selective maskingilicon dioxide layer is used tolhc regions to be diffused Diffusionopant into semiconductor elementsunction of lime and icmpeiature. The greater the desired dopant density, the higher the baking tcmperaiuie and/or the longer the wafer is heated The majority of new diffusion furnaces for use rn product ion incorporate compuier process control toigh level of accuracy in repetitive diffusion open lion;
The more recent doping technique is ion implant a! tor the direct infection of dopant atoms into the wafer. Automated ion implantcr? are required for processing
ICs wilh fen uie sizesicrons or lewof comCs may involve as many asifferent ion implantation steps One of the major advantages of implantation over diffusion is better control of doping profiles because of lower processing lemperalures
Assembly and Packaging
Assembly is the step following wafer processing After the individual ICs on the wafer arc sawed apail (using diamond scribes, laser scribes, or small diamondhe functional parts (see "Testing'* section) are attachedackage in the die-bonding step. Die bonders may be manual, semiautomatic, or fully automatic
Die bonding is followed by wire bonding, the major rrsethod used to connect the die electrically toleading outside the package Wire bonding may be performed manually, semiautomatically. oiGenerally, the higher the degree ofthe higher the quality of the bond*
Tbe final step is etscapsaialion, or packaging, in which thcIC is enclosed in plastic or ceramic. MostICs are packaged in plasticetal lead frame deiigned for automatic assembly. The most common package type is the dual in-line package (DIP) Plastic DIPS arc cheap and easylute, but arc relatively fragile andoor thermal dissipation characteristics. The more costly, bul more durable, ceramic packages arc reserved for ICsfor ngorous environments, such as military electronics systems High-performance ICs forand space environments require packages that can protect them from high levels of radiation and vibration and extreme temperatures
nondestructive measurement of circuit dimensions on ptsotosrusfcs or wafers Scanning electron microsences are replacing optical line-width measurement systems for inspecting critical dimensionsicrons or lev "
The wafer probe is used forrving of electrical and functional characteristics of die onmall number of lests arc made, although not at ihe circuit's operating speed The purpose of the test is to mark defective ICs before time and money arein bonding aod pacta ginj
Packaged IC testers include both burn-in systems and functional testers Burn-in systems are used toquickly the pans thai would fail soon after first use Batches of ICs are loadedempera ture-and humidity-controlled chamber, powered up, and allowed to sitengih of time to simulate long-term normal use. Most weak parts fail at this stage, allowing the IC producer io weed out unreliable devices
Functional testers are used to verify that an IC works properly at its intended operating speed. These testers aie usually classifiedombination of twothe rnaiimum number of pans it can test, and the speed ai which it can test Ihe device. These iwo characteristics arc inversely propotlional to each(lhc moreevice has, lhc more time it takes to lest it. hence, ihe needaster tester)lesi equipment is aiso defined by us man mum memory testing capability, for cuampte. MSI. LSI. VLSI, and so foith. The most powerful testers can test devicesinsegahertz. These testers require citensive computing power and soft ware packages that must be updated Tor each new product devclopmen'
Testing
IC testers include equipment used to test the wafers on line during various processing stages andused lo test the packaged device Optical line-width measurement systems are used on line for the
Original document.
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