Tam sim no, SiC kev lag luam yog hloov los ntawm 150 hli (6 nti) mus rau 200 hli (8 nti). Yuav kom ua tau raws li qhov kev thov ceev rau qhov loj-loj, zoo SiC homoepitaxial wafers hauv kev lag luam, 150mm thiab 200mm4H-SiC homoepitaxial waferstau ua tiav tiav ntawm cov khoom siv hauv tsev siv tus kheej tsim 200mm SiC epitaxial loj hlob cov cuab yeej. Cov txheej txheem homoepitaxial haum rau 150mm thiab 200mm tau tsim, uas qhov kev loj hlob ntawm epitaxial tuaj yeem siab dua 60um / h. Thaum ntsib lub high-speed epitaxy, lub epitaxial wafer zoo yog zoo heev. Lub thickness uniformity ntawm 150 hli thiab 200 hliSiC epitaxial waferstuaj yeem tswj tau nyob rau hauv 1.5%, qhov concentration uniformity tsawg dua 3%, qhov kev tuag tsis zoo yog tsawg dua 0.3 particles / cm2, thiab epitaxial nto roughness hauv paus txhais tau tias square Ra yog tsawg dua 0.15nm, thiab tag nrho cov txheej txheem tseem ceeb yog nyob ntawm qib siab ntawm kev lag luam.
Silicon Carbide (SiC)yog ib qho ntawm cov neeg sawv cev ntawm cov khoom siv semiconductor thib peb. Nws muaj cov yam ntxwv ntawm kev ua haujlwm siab tawg, zoo thermal conductivity, loj electron saturation drift tshaj tawm, thiab muaj zog hluav taws xob tsis kam. Nws tau nthuav dav lub zog ua kom muaj peev xwm ntawm cov cuab yeej siv hluav taws xob thiab tuaj yeem ua tau raws li cov kev xav tau ntawm cov khoom siv hluav taws xob txuas ntxiv mus rau cov khoom siv hluav taws xob loj, me me, kub kub, hluav taws xob hluav taws xob thiab lwm yam kev mob hnyav. Nws tuaj yeem txo qhov chaw, txo kev siv hluav taws xob thiab txo qhov xav tau cua txias. Nws tau coj cov kev hloov pauv hloov mus rau lub zog tshiab, tsheb thauj mus los, cov phiajcim ntse thiab lwm yam. Yog li ntawd, silicon carbide semiconductors tau dhau los lees paub tias yog cov khoom siv zoo tshaj plaws uas yuav ua rau cov tiam tom ntej ntawm cov khoom siv hluav taws xob muaj zog. Nyob rau hauv xyoo tas los no, ua tsaug rau lub teb chaws txoj cai txhawb rau txoj kev loj hlob ntawm lub thib peb-tiam semiconductor kev lag luam, kev tshawb fawb thiab kev loj hlob thiab kev tsim kho ntawm 150 hli SiC ntaus ntawv kev lag luam system tau pib ua tiav nyob rau hauv Suav teb, thiab kev ruaj ntseg ntawm kev lag luam saw. tau yeej guaranteed. Yog li ntawd, lub hom phiaj ntawm kev lag luam tau maj mam hloov mus rau kev tswj tus nqi thiab kev txhim kho kev ua haujlwm. Raws li pom nyob rau hauv Table 1, piv nrog 150 hli, 200 hli SiC muaj ib tug ntau dua ntug siv tus nqi, thiab cov zis ntawm ib tug wafer chips yuav nce li ntawm 1.8 npaug. Tom qab cov thev naus laus zis loj hlob tuaj, tus nqi tsim khoom ntawm ib nti tuaj yeem raug txo los ntawm 30%. Kev siv thev naus laus zis ntawm 200 hli yog qhov ncaj qha ntawm "txo cov nqi thiab nce kev ua tau zoo", thiab nws tseem yog tus yuam sij rau kuv lub teb chaws txoj kev lag luam semiconductor kom "khiav mus ib txhis" lossis txawm tias "cov txhuas".
Sib txawv ntawm Si ntaus ntawv txheej txheem,SiC semiconductor fais fab khoom sivyog tag nrho cov txheej txheem thiab npaj nrog epitaxial txheej raws li lub hauv paus pob zeb. Epitaxial wafers yog cov ntaub ntawv tseem ceeb rau SiC cov khoom siv hluav taws xob. Qhov zoo ntawm cov txheej epitaxial ncaj qha txiav txim siab cov txiaj ntsig ntawm cov cuab yeej, thiab nws cov nqi suav rau 20% ntawm cov nqi tsim khoom. Yog li ntawd, kev loj hlob epitaxial yog qhov tseem ceeb nruab nrab txuas hauv SiC cov khoom siv hluav taws xob. Kev txwv sab saud ntawm cov txheej txheem epitaxial yog txiav txim los ntawm cov khoom siv epitaxial. Tam sim no, qhov kev kawm hauv cheeb tsam ntawm 150mm SiC epitaxial cov cuab yeej hauv Suav teb yog qhov siab, tab sis tag nrho cov qauv ntawm 200mm lags qab qib thoob ntiaj teb tib lub sijhawm. Yog li ntawd, txhawm rau daws cov kev xav tau ceev thiab cov teeb meem hauv lub cev ntawm qhov loj-loj, cov khoom siv zoo epitaxial tsim rau kev txhim kho ntawm kev lag luam thib peb hauv kev lag luam semiconductor, daim ntawv no qhia txog 200 hli SiC epitaxial cov cuab yeej ntse tsim hauv kuv lub teb chaws, thiab kawm txog cov txheej txheem epitaxial. Los ntawm optimizing cov txheej txheem tsis xws li txheej txheem kub, cab kuj gas ntws tus nqi, C / Si piv, thiab lwm yam., lub concentration uniformity <3%, thickness non-uniformity <1.5%, roughness Ra <0.2 nm thiab tuag defect ntom <0.3 nplej. /cm2 ntawm 150 hli thiab 200 hli SiC epitaxial wafers nrog nws tus kheej tsim 200 hli silicon carbide epitaxial rauv tau. Cov txheej txheem cov cuab yeej tuaj yeem ua tau raws li qhov xav tau ntawm cov khoom siv hluav taws xob zoo SiC kev npaj.
1 Kev sim
1.1 Txoj Cai ntawmSiC epitaxialtxheej txheem
Txoj kev loj hlob ntawm 4H-SiC homoepitaxial feem ntau suav nrog 2 cov kauj ruam tseem ceeb, uas yog, qhov kub thiab txias hauv qhov chaw etching ntawm 4H-SiC substrate thiab homogeneous tshuaj vapor deposition txheej txheem. Lub hom phiaj tseem ceeb ntawm substrate nyob rau hauv-situ etching yog tshem tawm cov subsurface puas ntawm lub substrate tom qab wafer polishing, residual polishing kua, hais thiab oxide txheej, thiab ib tug li niaj zaus atomic kauj ruam qauv yuav tsim nyob rau hauv lub substrate nto los ntawm etching. In-site etching feem ntau yog ua nyob rau hauv ib qho chaw hydrogen. Raws li cov txheej txheem tiag tiag, ib qho me me ntawm cov pa roj kuj tuaj yeem ntxiv, xws li hydrogen chloride, propane, ethylene lossis silane. Qhov kub ntawm hauv-situ hydrogen etching feem ntau yog siab tshaj 1 600 ℃, thiab lub siab ntawm cov tshuaj tiv thaiv chamber feem ntau tswj hauv qab 2 × 104 Pa thaum lub sij hawm etching txheej txheem.
Tom qab lub substrate nto yog qhib los ntawm in-situ etching, nws nkag mus rau lub high-kub tshuaj vapor deposition txheej txheem, uas yog, qhov chaw loj hlob (xws li ethylene / propane, TCS / silane), doping qhov chaw (n-hom doping qhov nitrogen , p-hom doping qhov chaw TMAl), thiab cov pa pab cuam xws li hydrogen chloride raug thauj mus rau cov tshuaj tiv thaiv chamber los ntawm cov pa loj ntawm cov cab cab (feem ntau hydrogen). Tom qab cov roj reacts nyob rau hauv lub high-temperature cov tshuaj tiv thaiv chamber, ib feem ntawm cov precursor reacts tshuaj thiab adsorbs ntawm lub wafer nto, thiab ib leeg-crystal homogeneous 4H-SiC epitaxial txheej nrog ib tug tshwj xeeb doping concentration, tej thickness, thiab zoo dua yog tsim. ntawm lub substrate nto siv ib leeg-crystal 4H-SiC substrate ua tus qauv. Tom qab xyoo ntawm kev tshawb fawb, 4H-SiC homoepitaxial thev naus laus zis tau pib loj hlob thiab tau siv dav hauv kev tsim khoom. Kev siv 4H-SiC homoepitaxial thev naus laus zis ntau tshaj plaws hauv ntiaj teb muaj ob yam ntxwv zoo:
(1) Siv ib qho off-axis (kuj rau <0001> siv lead ua dav hlau, mus rau <11-20> siv lead ua kev taw qhia) oblique txiav substrate raws li ib tug template, high-purity ib leeg-crystal 4H-SiC epitaxial txheej tsis muaj impurities yog tso rau ntawm lub substrate nyob rau hauv daim ntawv ntawm step-flow txoj kev loj hlob hom. Thaum ntxov 4H-SiC homoepitaxial kev loj hlob siv lub zoo crystal substrate, uas yog, lub <0001> Si dav hlau rau kev loj hlob. Qhov ntom ntawm cov kauj ruam atomic nyob rau saum npoo ntawm qhov zoo crystal substrate yog tsawg thiab cov terraces yog dav. Ob-dimensional nucleation kev loj hlob yog ib qho yooj yim tshwm sim thaum lub sij hawm epitaxy txheej txheem los ua 3C crystal SiC (3C-SiC). Los ntawm kev txiav tawm, qhov siab-density, nqaim terrace dav atomic cov kauj ruam tuaj yeem nkag mus rau ntawm qhov chaw ntawm 4H-SiC <0001> substrate, thiab cov adsorbed precursor tuaj yeem ncav cuag atomic kauj ruam txoj haujlwm nrog lub zog qis ntawm qhov chaw diffusion. . Nyob rau hauv cov kauj ruam, lub precursor atom / molecular pab pawg neeg bonding txoj hauj lwm yog tshwj xeeb, yog li nyob rau hauv cov kauj ruam khiav txoj kev loj hlob hom, lub epitaxial txheej yuav zoo kawg nkaus txais tau lub Si-C ob atomic txheej stacking ib theem zuj zus ntawm lub substrate los tsim ib tug siv lead ua nrog tib crystal. theem raws li lub substrate.
(2) Kev loj hlob sai ntawm epitaxial yog ua tiav los ntawm kev qhia txog cov tshuaj chlorine uas muaj silicon. Nyob rau hauv cov pa SiC tshuaj vapor deposition systems, silane thiab propane (los yog ethylene) yog lub hauv paus loj hlob. Nyob rau hauv tus txheej txheem ntawm kev loj hlob tus nqi los ntawm kev nce qhov kev loj hlob qhov txaus tus nqi, raws li qhov sib npaug ib feem ntawm lub siab ntawm silicon tivthaiv tseem nce ntxiv, nws yog ib qho yooj yim rau tsim silicon pawg los ntawm homogeneous roj theem nucleation, uas txo qhov kev siv ntawm tus nqi. silicon qhov chaw. Kev tsim ntawm silicon pawg txwv kev txhim kho ntawm epitaxial kev loj hlob tus nqi. Nyob rau tib lub sijhawm, cov pawg silicon tuaj yeem cuam tshuam cov kauj ruam khiav kev loj hlob thiab ua rau muaj qhov tsis xws luag. Txhawm rau zam kom tsis txhob muaj cov pa roj carbon monoxide theem nucleation thiab nce qhov kev loj hlob ntawm epitaxial, kev qhia txog cov tshuaj chlorine-based silicon tam sim no yog txoj hauv kev tseem ceeb los ua kom cov epitaxial loj hlob ntawm 4H-SiC.
1.2 200 mm (8-nti) SiC epitaxial cov cuab yeej thiab cov txheej txheem txheej txheem
Cov kev sim uas tau piav qhia hauv daim ntawv no tau ua tiav ntawm 150/200 mm (6/8-nti) sib xws monolithic kab rov tav kub phab ntsa SiC epitaxial khoom ntawm nws tus kheej tsim los ntawm 48th Institute of China Electronics Technology Group Corporation. Lub tshuab hluav taws xob epitaxial txhawb nqa tag nrho tsis siv neeg wafer loading thiab unloading. Daim duab 1 yog daim duab schematic ntawm cov qauv sab hauv ntawm cov tshuaj tiv thaiv chamber ntawm cov khoom siv epitaxial. Raws li pom nyob rau hauv daim duab 1, lub sab nrauv phab ntsa ntawm cov tshuaj tiv thaiv chamber yog ib tug quartz tswb nrog ib tug dej-txias interlayer, thiab sab hauv ntawm lub tswb yog ib tug high-kub tshuaj tiv thaiv chamber, uas yog tsim los ntawm thermal rwb thaiv tsev carbon xav, high-purity. tshwj xeeb graphite kab noj hniav, graphite gas-floating rotating puag, thiab lwm yam. Tag nrho cov quartz tswb yog them nrog ib tug cylindrical induction coil, thiab cov tshuaj tiv thaiv chamber hauv lub tswb yog electromagnetically rhuab los ntawm nruab nrab zaus induction fais fab mov. Raws li pom nyob rau hauv daim duab 1 (b), cov cab kuj roj, cov tshuaj tiv thaiv roj, thiab cov roj doping tag nrho ntws los ntawm lub wafer nto nyob rau hauv ib tug kab rov tav laminar ntws los ntawm lub sab sauv ntawm cov tshuaj tiv thaiv chamber mus rau downstream ntawm cov tshuaj tiv thaiv chamber thiab yog tawm los ntawm tus Tsov tus tw. gas kawg. Txhawm rau kom ntseeg tau qhov sib xws hauv wafer, lub wafer nqa los ntawm huab cua ntab puag yog ib txwm tig thaum lub sijhawm ua haujlwm.
Lub substrate siv nyob rau hauv qhov kev sim yog ib tug coj mus muag 150 hli, 200 hli (6 nti, 8 nti) <1120> kev taw qhia 4° tawm-angle conductive n-hom 4H-SiC ob-sided polished SiC substrate tsim los ntawm Shanxi Shuoke Crystal. Trichlorosilane (SiHCl3, TCS) thiab ethylene (C2H4) yog siv los ua lub hauv paus loj hlob hauv cov txheej txheem kev sim, ntawm cov uas TCS thiab C2H4 yog siv los ua silicon qhov chaw thiab cov pa roj carbon feem ntau, high-purity nitrogen (N2) yog siv los ua n- hom doping qhov chaw, thiab hydrogen (H2) yog siv los ua dilution gas thiab cab cab. Qhov kub ntau ntawm cov txheej txheem epitaxial yog 1 600 ~ 1 660 ℃, cov txheej txheem siab yog 8 × 103 ~ 12 × 103 Pa, thiab H2 cov cab kuj roj ntws yog 100 ~ 140 L / min.
1.3 Epitaxial wafer kuaj thiab tus cwj pwm
Fourier infrared spectrometer (cov cuab yeej tsim khoom Thermalfisher, qauv iS50) thiab mercury sojntsuam concentration tester (cov khoom tsim khoom Semilab, qauv 530L) tau siv los ua tus yam ntxwv thiab kev faib tawm ntawm epitaxial txheej thickness thiab doping concentration; lub thickness thiab doping concentration ntawm txhua lub ntsiab lus nyob rau hauv lub epitaxial txheej tau txiav txim los ntawm kev noj cov ntsiab lus nyob rau hauv txoj kab uas hla txoj kab hlais ib txwm kab ntawm lub ntsiab siv ntug ntawm 45 ° ntawm qhov chaw ntawm lub wafer nrog 5 hli ntug tshem tawm. Rau 150 hli wafer, 9 cov ntsiab lus raug coj los ntawm ib txoj kab uas hla ib kab (ob txoj kab uas hla yog perpendicular rau ib leeg), thiab rau 200 hli wafer, 21 cov ntsiab lus raug coj mus, raws li qhia hauv daim duab 2. Ib qho atomic force microscope (cov khoom tsim khoom. Bruker, qauv Dimension Icon) tau siv los xaiv 30 μm × 30 μm thaj chaw hauv thaj chaw nruab nrab thiab thaj tsam ntug (5 hli ntug tshem tawm) ntawm lub epitaxial wafer los ntsuam xyuas qhov roughness ntawm lub epitaxial txheej; Qhov tsis xws luag ntawm cov txheej epitaxial tau ntsuas los ntawm kev ntsuas qhov tsis xws luag (cov khoom siv hauv Tuam Tshoj Electronics Lub 3D imager yog tus cwj pwm los ntawm lub radar sensor (qauv Mars 4410 pro) los ntawm Kefenghua.
Post lub sij hawm: Sep-04-2024