1 P= - Shigekawa Lab. (Institute of Applied Physics,...
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J^pAJIE S E T hU 州∧LOr′l pl ,LJEDPHYS JC S V r)L. 29,Nn . 三. r;FTITtU八RY.1990. p p . Ll95-L197 DependenceoflJleCarrierCo･rleerLtmtiorlProLiJeat仙eSi M丑ELayer/p-SiSubs･trateh t e r紬 ｡eOn他eSiSubs的 te PrepaFalfjonMetTIOd HjTOyukiK′lNAY ^ ,HjdeTnjSHIG即AWA,Fumio~H^sECj^W ^ andEjsoYA 仙＼K ^ 1 /Jzs r iIL/(e O fiVL7(CrI'dISc i elt C e,ult )､le √如7yOJ-Tszll,lLbu. 7hli.tJ/)aScJ'eIEreCil ∫305 . Tsui'LJbuCollegea /TechJtO/0 & V, Tstll'Ltb"Su'F･rCeCJ Z y305 (ReceivedNovemberlOJ989;EICぐ叩tedforpllbliealLO ll .Ja 1111 ary1l,1990) Tllemflue【】cec･rtheSisulJSLFalepTePar al ior1methodontわec･こITTiercone州tra【10日】TrOr. I, e ;I lTheSiML3Ehycr/】トSI subslJ′atPinlerrace"ra5Stu(lied.llwasr Ot indHlilLlhcSJ-SubsLraLeShollldbepLaccdjn‖1LIUTiVMBEi.hBmbe日日1medi- alCLy(､､･1Lllill柑minule S )｡rTerremova一orLheoxideLa)ref to dizllinaLe【l l eP+izltCrraCClayerandmustbehc.lledupTO 】 250oCbef()TeMllEgro､v l h,inorderlopreventcaTricrdepletjollatlheinleTraeeandalso10ObLalnSO O【)/- I/C.haracI Crj i - 1ic川｢adiodewilれaSHjcidC/P-Sl'(OISiGe)hFIBElayer/p-SisubsILaLeSLruClurC. KEYWORDS:SIノSiGe′moJecularbeamepitaxy,oxidePaye._carrierCOnCenlralionpro川e.inter†e)ce.Schotlky diode $1,tntJ'OduL-tjorL APtSi/p-SiSchoLlkycotltaetisno､vusedforaLarge- scalelRimagesellSOrinthewavelellgthrallgeOf3-5 Flm.HsilleetheabsoTpLionorinrraTed(]R)radiationin theaIlt]()Spherejsverysulallinthewaヽ√elengLhrangeor 8-12〃 1 1.andtheradiELtionpeakoftheobjectaHOOtll temperatureisarol川d】0仰 1 1,anIRimagesensorfortllis long-"･aveler唱tllrar唱ejsveryJrnpoTt-anL,Tbererore,fur- lhcrextcllSiortol■theeuto打Wavelengt11isurgentlyneeded especiallylntheweathersateHite n eld･ヱ) Wehavebe･enstudyingPl/p-Si H Ge.L･/p-SiSchotlky conl･dCtSainlir唱ataLongerwa＼一e)engthrRsensoralld havedemonstratedtha tthe SehoHkybarrierheightscall bereducedbyillCreaSlngtheGeFraction , 3)oneorthe obstacLeぎloJ.eaJizatioLl0∫aPt/ド-Sil_rGeLIRsensorisa lowbreakdowIIVOLtageorthePL/p-SiI-,Ge,Schouky diodes.lI1Ordertoreal i zeaguardriT]gSt∫uCtt】reforthe lO fl 11トrangeCCD imageserlSOTillthefutureandto utj]izeastrainedSjGelaye r , 4)theepitaxjallayershould beasthinaspossjble.ltwasreported.however,thatap- Lypehighcarriereoncentratio Jl (1017-1Oはcm--1)region orlCn叩PeaJl.Sa L tJle山terfacebetwee】1theSiMBflayer andp-typeSisubslraLe･川ThjShighCarriercollCeLltTとt- tionLayermlLS(innuencethebreakdowTl､′0止ageofthe Pt/p-Si卜..lGeJp-SisubstraleScllOtLkydiodeswhendle epjtaxiaHayerist LliJ). Kubiak et a / . reportedulaHltisheavilyp-typelayerat theinleTraCeWasrOrtnedby1)orotlintroducedfromthe borosuieate･glassofHleVie＼叩OrtintheMBEsysICm. j) 0】1theotherhalュd,Cas ele /a / . demonslraledastTOIlg dependenceorthe LT lt_erraCeP+Layerontheexisle1-CeOl the.surfaceo,yide)aycroftheSisubstrate. 61 1tiswidelyac- ceptedthataCareruuyPrepal'edsurraceoxidelayerisin- eyi(ableIoobtainahigJlqualitySi M BE一aye r.71 ll ist101 yetknowllhow tocompromisethesetwoCOnnicting pheDOmeTla;tlleOXidelayeristleCeSSaryForahighquali- tyM月Elayer,butiti】1trOdtlCeSaBoron-dopedp +layer L195 attheinterface. ThepllrPOSeOfthisworkistohldaprepa】'ationa]1d cleaningmethodloTtheSjsubstJatetOObtainahigh quali_tySiandSiGcMBElayerwiLhouLlhcp+血erfaee regionattlleePi-substJateinterface. 尊2. E叩erimental MBElayersweregrownonp-type(100)CzochralskiSi substraLe St P= 3-5×10Mcm~Ll). ThebasepressLLreOf thcMBEsystemヽvasabollL3XLO-1｡TorTaudthatorlhc load lock erlamber Was about 10~7Torr.Sjwas evaporatedbyanE-gtInandGe.byaK-c el l.TheSianJd GemOleclllarbea川sWereCO】止roucdbylnOnirorillgWith allelectronhl叩aCtenliss-ionspecLfOSCOPy(EIES)se】lS Or. sHayers､veregro､､,nat750oCatarateof1.5 A/ S . SiGe Layers､veregTOWllat550oC a【arateo r 1.5-2.OA/ら. Thepressuredurjugthe･growLltWaSト 3･xIO-1)Torrr TlleBoronwasdopedinbothLayerswithHBO2.The subs【rateculin2cmsqlLareS~WaSPreC)eatledbythetlSuaL rshi祖ka-Shirakimethod.7'Forsome substrates,the passjvalionoxidelayerswerecomp】ctelyremovedbya dilutedHF(0.5%)soIuLionbeforethesubslraleSWere placedintlleMBEchamber.ThesllbstrateintheM13E cIlambefWasheatedLLPtOabotlt85()oCtoevaporatethe surraceo,yide)aycrbcrorel7leSigrowth.lnsomecases , thesubstJateWEISheatedup(012.500CloTeulOVetileC A卜 bollOlHhesubs(rate.Carrie･rcollCentratjollPrO丘Iesat thejnterracewerecaleuja(.ed frotllthecapacjtance- voltage (C-V) characteristicsmeasuredbyaTiSchouky contac t. 昏3.RcSuHsaTtdDjs川SSion Becausefくubiakel(J J . repol.I,edthattheaccL)mLllalion orBoronattheSiepi-Substrateinter一acewasTelaLedto thethjckIユeSSOrthepassivatioll0Kidclayer,weRTStin- vestigateddependenceoftheBoronaccumuLaLionon(he thicknessoftheoxidelaye r .A一terrorlnationorthe passivatjo工IOXidelayerbylshilZaka･Shirakimethod,tJle
Transcript of 1 P= - Shigekawa Lab. (Institute of Applied Physics,...
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JpAJIESEThULOrlpl,LJEDPHYSJCSVr)L.29,Nn..r;FTITtURY.1990.pp.Ll95-L197
DependenceoflJleCarrierCorleerLtmtiorlProLiJeateSi
ME Layer/p-SiSubstrateh tereOneSiSubs te
PrepaFalfjonMetTIOd
HjTOyukiKlNAY,HjdeTnjSHIGAWA,Fumio~H sECjWandEjsoYAK 1
/JzsriIL/(eOfiVL7(CrI'dIScieltCe,ult)le7yOJ-Tszll,lLbu.
7hli.tJ/)aScJ'eIEreCil305
.Tsui'LJbuCollegea/TechJtO/0&V,Tstll'Ltb"Su'FrCeCJZy305
(ReceivedNovemberlOJ989;EICtedforpllbliealLOll.Ja1111ary1l,1990)
TllemfluececrtheSisulJSLFalepTeParalior1methodontecITTierconetra10TrOr.I,e;IlTheSiML3Ehycr/SIsubslJatPinlerrace"ra5Stu(lied.llwasrOtindHlilLlhcSJ-SubsLraLeShollldbepLaccdjn1LIUTiVMBEi.hBmbe1medi-alCLy(1LllillminuleS)rTerremovaorLheoxideLa)reftodizllinaLelleP+izltCrraCClayerandmustbehc.lledupTO250oCbef()TeMllEgrovlh,inorderlopreventcaTricrdepletjollatlheinleTraeeandalso10ObLalnSOO)/-I/C.haracICrji-1icadiodewilaSHjcidC/P-Sl'(OISiGe)hFIBElayer/p-SisubsILaLeSLruClurC.
KEYWORDS:SISiGemoJecularbeamepitaxy,oxidePaye._carrierCOnCenlralionproe.intere)ce.Schotlkydiode
$1, tntJ'OduL-tjorL
APtSi/p-SiSchoLlkycotltaetisnovusedforaLarge-
scalelRimagesellSOrinthewavelellgthrallgeOf3-5
Flm.HsilleetheabsoTpLionorinrraTed(]R)radiationintheaIlt]()SpherejsverysulallinthewaelengLhrangeor
8-1211.andtheradiELtionpeakoftheobjectaHOOtlltemperatureisarold011,anIRimagesensorfortllislong-"avelertllrarejsveryJrnpoTt-anL,Tbererore,fur-
lhcrextcllSiortoltheeutoWavelengt11isurgentlyneeded
especiallylntheweathersateHiteneld)WehavebeenstudyingPl/p-SiHGe.L/p-SiSchotlky
conldCtSainlir ataLongerwae)engthrRsensoralld
havedemonstratedthattheSehoHkybarrierheightscallbereducedbyillCreaSlngtheGeFraction,3)oneortheobstacLeloJ.eaJizatioLl0aPt/-Sil_rGeLIRsensorisa
lowbreakdowIIVOLtageorthePL/p-SiI-,Ge,Schouky
diodes.lI1OrdertorealizeaguardriT]gStuCttreforthe
lOfl11rangeCCD imageserlSOTillthefutureand toutj]izeastrainedSjGelayer,4)theepitaxjallayershould
beasthinaspossjble.ltwasreported.however,thatap-
LypehighcarriereoncentratioJl(1017-1Ocm--1)region
orlCnPeaJl.SaLtJleterfacebetwee1theSiMBflayer
andp-typeSisubslraLe ThjShighCarriercollCeLltTt-
tionLayermlLS(innuencethebreakdowTl0ageofthe
Pt/p-Si..lGeJp-SisubstraleScllOtLkydiodeswhendleepjtaxiaHayeristLliJ).
Kubiaketa/.reportedulaHltisheavilyp-typelayerattheinleTraCeWasrOrtnedby1)orotlintroducedfromthe
borosuieateglassofHleVieOrtintheMBEsysICm.j)
01theotherhald,Casele/a/.demonslraledastTOIlg
dependenceortheLTlt_erraCeP+Layerontheexisle1-CeOl
the.surfaceo,yide)aycroftheSisubstrate.611tiswidelyac-ceptedthataCareruuyPrepal'edsurraceoxidelayerisin-
eyi(ableIoobtainahigJlqualitySiMBEayer.71llist101yetknowllhow tocompromisethesetwoCOnnicting
pheDOmeTla;tlleOXidelayeristleCeSSaryForahighquali-
tyMElayer,butiti1trOdtlCeSaBoron-dopedp+layer
L195
attheinterface.
ThepllrPOSeOfthisworkistohldaprepa'ationa]1d
cleaningmethodloTtheSjsubstJatetOObtainahigh
quali_tySiandSiGcMBElayerwiLhouLlhcp+erfaee
regionattlleePi-substJateinterface.
2. Eerimental
MBElayersweregrownonp-type(100)CzochralskiSi
substraLeStP=3-510Mcm~Ll).ThebasepressLLreOfthcMBEsystem vasabollL3XLO-1TorTaudthatorlhcload lock erlamber Was about 10~7Torr.Sjwas
evaporatedbyanE-gtInandGe.byaK-cell.TheSianJdGemOleclllarbeasWereCOroucdbylnOnirorillgWith
allelectronhlaCtenliss-ionspecLfOSCOPy(EIES)selSOr.sHayersveregro,nat750oCatarateof1.5A/S.SiGeLayersveregTOWllat550oCaarateor1.5-2.OA/.
ThepressuredurjugthegrowLltWaS 3xIO-1)Torrr
TlleBoronwasdopedinbothLayerswithHBO2.The
subsrateculin2cmsqlLareS~WaSPreC)eatledbythetlSuaLrshika-Shirakimethod.7'Forsomesubstrates,the
passjvalionoxidelayerswerecompctelyremovedbyadilutedHF(0.5%)soIuLionbeforethesubslraleSWere
placedintlleMBEchamber.ThesllbstrateintheM13E
cIlambefWasheatedLLPtOabotlt85()oCtoevaporatethe
surraceo,yide)aycrbcrorel7leSigrowth.lnsomecases,thesubstJateWEISheatedup(012.500CloTeulOVetileCAbollOlH hesubs(rate.CarriercollCentratjollPrOIesat
thejnterracewerecaleuja(.ed frotllthecapacjtance-
voltage(C-V)characteristicsmeasuredbyaTiSchoukycontact.
3. RcSuHsaTtdDjsSSion
Becausefubiakel(JJ.repol.I,edthattheaccL)mLllalion
orBoronattheSiepi-SubstrateinteracewasTelaLedto
thethjckIeSSOrthepassivatioll0Kidclayer,weRTStin-
vestigateddependenceoftheBoronaccumuLaLionon(hethicknessoftheoxidelayer.AterrorlnationorthepassivatjoIOXidelayerbylshilZakaShirakimethod,tJle
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l
LM6 Hiro)ruklKNY .Tii(knliSilLG W.FunlloHLlECmandEjiOY lk,
oxidelayerVaSthinnedbyadilutedHFI.SOlution(0.5%).andSisubslrateSWiththreedjqcrcnlOXide)ayers(0.
-5,-15A)wererol'med.
Figure1shosthecarrierconer)tralionprorllLISalthe
MBESilayer/pISisubslrateinlerlaces.Arowsinllle
fi_uLlrleindicatepositionsor(heWBESilayer/p-SiSubin-
Lerraccs.TheLbjck1eSSOftheoxidelayerorsaJllPleA
Waszero.thatorsampLeBWaSabout5andnat0rSam-
pJeC("rhoseoxidelayerwa.inotremovedbythedilutedHFsolutioll)wasabout15A.TheLhjekleSSOrtheoxidelayerwastjmatedbylheetelmi grateOrtheo,Videlayer.
SampleAllTaSPJacedl'ntheUH~VMBEehanlberWithjl110minutesarte1-remova0rLheoxideLayer,Withoutrins-
1nglnWaferI-Oavoido,yidationor(_hesLLbstratesurface
b),thewater_S(lmPlesBandCwereTjnsedinWaterafter
etchingbythedilutedHF.TheseSamplesWereheatedto
e-vaporatetheoxjdelayers.SampleA sho.eda2
RHEEDpaHe a1400oC,sampleBshowedjlat680oL-andsaruplcCshoweditat85OoC.NoSicRHEEDpat-ternwasobservedForLhcscsamples.SanlpJcsBalldC
showalmosHhesalTleheight()rthecarl.iercollCel1tration
peakjnFig.I,but5ampleAdoesUOLTheselesuLISizdicatetllattJICpLlayeraHheinterfacecanbeleducedby
remolLtgtheoxideJayerasrepor(edbyCaseJetaJ.61llisnotwellknownWheretheBoroncomesfrom.ltmightbe
From borosi)icaleglass/IbutothercalldidaLesaretlle
substrateand(,llmospllereitself.lnanycase,whenlhcox-
idelaycreJYisLS,theT3oroui.sthoughHoaccutnulateiTHheoxidelayerrroTnthesurroundingsandtobelerIOnthe
sub.slraleSurfacewhentheoxidelaveriSevaporate(1.
WhentlleOXidepassivationfilm WaslllillnedbythediltltedHFtheSicRHEEDpatlem WasOrtet]Observed
oJlthesurfacewhentheSjsubstralCWasheatedupto
aboe750oC.FjgL)re2ShowslflCCarrierconccntralionpronJealtheSiMBELayer/l)-Sisubstraleinterraccsor
(C
5/NOllVtJL
NuUNO3-
V3
1d5DEPTHFROM 5U,RFACE
(Hnl)
Rs.,CarrjcrcollcLelfraHor)prOr12esilltheSilVIL3Elaye-/p-SisubstrIleinlCTlilCeS.The.thlCknLlSSCOfoxidelayerereaSrOHoWs:StlnlPleA Ze)0.BvllS5dCw;lSI_5.
I(
eEUL/Ft)NOLLy
NuU.NO3
I,
V3
7
6
10t
1d0 .1 .2 ,3 .4 .5
DEPTH FROM SURFACE
(Hm)
FLR.2CarrierconLlltricPrOrlle.iaLtheSMJjEJFt)el/p-SSuhll1--errneeThelhjc-i,nesscsoroxidelayersrLH lirOHovs:snnlplFAlvaszero.BaTldCL'wcrL15A.JuJorl)1cmrLkLIptllt71elo,d-1(lCi.chaTTtbertor2hours.
theslmPLc.sonWhichtheSicRHEEDPaHernSWeTCOb-served.Tllethicknessoftheo;(idelJdyerOrSampleAill
Fig.2aszero:lhoseorBandCWeTeabout5A.Auor
lhcmWerekepththeload-ockcllamberO-7TorT)roT
2hoursbeforebeingheatedI)ptoS500CintheUuV
JMBEcllambertoevaporatetheo,tideLayer.TheinLen-
sjtiesoftheSic RjjEEDpauer11SOfsa111PLesAandC
werestTOlerthanLhaLOrSampleBDepletjonregiollS
o1ccarrierappealLedaltheMBElayeSllbSlra(ei1tCr-
racesroIausamp)es.TlleCat)SeOrthedepkLionregion
wasthoughtLobesomedefect.sintheMBEgrownlayerWhichwereintJOdLLCedbySic()lHhesllbstratesurface.
ForsarnpIeA,a2x1RHlEDpatternWas1101ObserveduntHthestlbstratetemperatllTeOf650cc,atttlOughttleOX-
idelayerWascornplctclyI:e10Ved.Thisi.sprobablydue
tofoTmatjonoftheo,yidelayeroraFewAwhilethesam-
plewaskeptintheload-)ockchamberfor2110urS.ThusbothadL,plelionandahighcarrierconcenlTalioLIL'egion
appearedinsampleA.Tniteortheoxidelayerexisllng
itlSatllp)csBandC,thehigllCaTriereollCenlralioIITeglOn
didl10Lalear.ThisisprobablyduetotheracHhaLthediodebreakdoWr10ccurrSbeforethedepLclion layer
reachestothehgtlCarriercollCenlrationregLOn.
To elarify the OTigiZOflhc depletion layer,Si
sLLbstrate.qwerehealedupto1250oCtoeaporateCar-bonontheslbstratesurraCe.SampJesAandBshownhlFig.3werekeptintlleload-lockchamberfor2hotlrsarlercomPIcteremovalorlheoXjdelaycT-byadilutedHFsolution.SampleAWasheatedupto850C,sanlPleB
IVaSheatedupto)2500CandheldI-hereror mjnutes.
SampleCwasplacedinLhcUHVh,lBEchamberwithiIILOmilltlteSafterrerllOVaLoftllCOXidetaycr,lleatedlipLo
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Dep(JTldeJT(Jet0/IkeCarrler/m/)I/O ()'Zi/LLI)priPLlF'7/l'ol/ Llt)7
(C
5/i)NOlly1
NUNO3tJFjl
