2 Kev sim cov txiaj ntsig thiab kev sib tham
2.1Epitaxial txheejthickness thiab uniformity
Epitaxial txheej thickness, doping concentration thiab uniformity yog ib tug ntawm cov tseem ceeb qhia rau txiav txim qhov zoo ntawm epitaxial wafers. Muaj tseeb tswj tau tuab, doping concentration thiab uniformity nyob rau hauv lub wafer yog tus yuam sij kom ntseeg tau qhov kev ua tau zoo thiab sib xws ntawmSiC cov khoom siv hluav taws xob, thiab epitaxial txheej thickness thiab doping concentration uniformity kuj tseem ceeb hauv paus rau kev ntsuas cov txheej txheem muaj peev xwm ntawm cov khoom siv epitaxial.
Daim duab 3 qhia lub thickness uniformity thiab faib nkhaus ntawm 150 hli thiab 200 hliSiC epitaxial wafers. Nws tuaj yeem pom los ntawm daim duab uas epitaxial txheej thickness faib nkhaus yog symmetrical txog qhov chaw nruab nrab ntawm lub wafer. Lub sijhawm txheej txheem epitaxial yog 600s, qhov nruab nrab epitaxial txheej thickness ntawm 150 hli epitaxial wafer yog 10.89 um, thiab lub thickness uniformity yog 1.05%. Los ntawm kev suav, qhov kev loj hlob ntawm epitaxial yog 65.3 um / h, uas yog cov txheej txheem ceev ceev ntawm epitaxial. Nyob rau tib lub sij hawm epitaxial txheej txheem, cov txheej txheem epitaxial thickness ntawm 200 hli epitaxial wafer yog 10.10 um, lub thickness uniformity nyob rau hauv 1.36%, thiab tag nrho cov kev loj hlob tus nqi yog 60.60 um / h, uas yog me ntsis qis dua 150 hli epitaxial kev loj hlob. tus nqi. Qhov no yog vim muaj qhov pom tseeb poob ntawm txoj kev thaum lub silicon qhov chaw thiab cov pa roj carbon ntws los ntawm cov dej ntws ntawm cov tshuaj tiv thaiv chamber los ntawm wafer nto mus rau hauv qab ntawm cov tshuaj tiv thaiv chamber, thiab 200 hli wafer cheeb tsam yog loj dua li 150 hli. Cov pa roj ntws los ntawm qhov chaw ntawm 200 hli wafer kom ntev dua, thiab cov roj siv los ntawm txoj kev yog ntau dua. Nyob rau hauv cov xwm txheej uas lub wafer ua kom tig, tag nrho cov thickness ntawm cov epitaxial txheej yog thinner, yog li qhov kev loj hlob qeeb qeeb. Zuag qhia tag nrho, lub thickness uniformity ntawm 150 hli thiab 200 hli epitaxial wafers yog zoo heev, thiab cov txheej txheem muaj peev xwm ntawm cov cuab yeej muaj peev xwm ua tau raws li qhov yuav tsum tau ntawm cov khoom zoo.
2.2 Epitaxial txheej doping concentration thiab uniformity
Daim duab 4 qhia txog doping concentration uniformity thiab nkhaus faib ntawm 150 mm thiab 200 mmSiC epitaxial wafers. Raws li tuaj yeem pom los ntawm daim duab, qhov kev faib tawm nkhaus ntawm lub epitaxial wafer muaj qhov pom tseeb symmetry txheeb ze rau qhov chaw ntawm lub wafer. Lub doping concentration uniformity ntawm 150 hli thiab 200 hli epitaxial txheej yog 2.80% thiab 2.66% raws li, uas tuaj yeem tswj tau li ntawm 3%, uas yog qib zoo rau cov khoom siv thoob ntiaj teb zoo sib xws. Lub doping concentration nkhaus ntawm lub epitaxial txheej yog faib nyob rau hauv ib tug "W" zoo raws li txoj kab uas hla txoj kab uas hla, uas yog tsuas yog txiav txim los ntawm lub ntws ntawm cov kab rov tav kub phab ntsa epitaxial rauv, vim hais tias cov airflow kev taw qhia ntawm kab rov tav airflow epitaxial loj hlob rauv yog los ntawm huab cua inlet kawg (sab sauv) thiab ntws tawm los ntawm downstream kawg nyob rau hauv ib tug laminar yam los ntawm lub wafer nto; vim hais tias "raws li txoj kev depletion" tus nqi ntawm cov pa roj carbon qhov chaw (C2H4) yog siab dua li ntawm silicon qhov chaw (TCS), thaum lub wafer tig, qhov tseeb C / Si ntawm lub wafer nto maj mam txo los ntawm ntug mus rau. qhov chaw (cov pa roj carbon monoxide hauv qhov chaw tsawg dua), raws li "kev sib tw txoj hauj lwm txoj kev xav" ntawm C thiab N, doping concentration nyob rau hauv nruab nrab ntawm lub wafer maj mam txo mus rau ntawm ntug, nyob rau hauv kev txiav txim. kom tau txais cov concentration zoo sib xws, ntug N2 yog ntxiv raws li kev them nyiaj thaum lub sij hawm epitaxial txheej txheem kom txo qis hauv doping concentration los ntawm qhov chaw mus rau ntug, kom qhov kawg doping concentration nkhaus nthuav tawm "W" duab.
2.3 Epitaxial txheej tsis xws luag
Ntxiv rau qhov tuab thiab doping concentration, qib ntawm cov txheej txheem epitaxial tsis raug tswj kuj yog qhov tseem ceeb rau kev ntsuas qhov zoo ntawm epitaxial wafers thiab ib qho tseem ceeb qhia txog kev muaj peev xwm ntawm cov khoom siv epitaxial. Txawm hais tias SBD thiab MOSFET muaj cov kev cai sib txawv rau qhov tsis xws luag, qhov pom tseeb ntawm qhov chaw morphology tsis xws luag xws li poob tsis xws luag, daim duab peb sab defects, carrot defects, comet defects, thiab lwm yam yog txhais tau tias yog killer defects ntawm SBD thiab MOSFET li. Qhov tshwm sim ntawm kev ua tsis tiav ntawm cov chips uas muaj cov tsis xws luag yog siab, yog li tswj tus naj npawb ntawm killer tsis xws luag yog ib qho tseem ceeb heev rau kev txhim kho nti tawm los thiab txo cov nqi. Daim duab 5 qhia txog kev faib cov neeg tua neeg tsis xws luag ntawm 150 mm thiab 200 mm SiC epitaxial wafers. Raws li qhov xwm txheej uas tsis muaj qhov tsis txaus ntseeg hauv qhov sib piv ntawm C / Si, cov zaub ntug hauv paus tsis xws luag thiab cov pob zeb loj tuaj yeem raug tshem tawm, thaum poob qhov tsis xws luag thiab daim duab peb sab muaj feem xyuam rau kev tswj kev huv thaum lub sijhawm ua haujlwm ntawm cov khoom siv epitaxial, impurity theem ntawm graphite. qhov chaw nyob rau hauv cov tshuaj tiv thaiv chamber, thiab qhov zoo ntawm lub substrate. Los ntawm Table 2, nws tuaj yeem pom tias cov neeg tua neeg tsis zoo ntawm 150 mm thiab 200 mm epitaxial wafers tuaj yeem tswj tau hauv 0.3 particles / cm2, uas yog qib zoo rau tib hom khoom. Qhov kev tuag tsis xws luag tswj qib ntawm 150 mm epitaxial wafer yog zoo dua li ntawm 200 mm epitaxial wafer. Qhov no yog vim hais tias cov txheej txheem kev npaj substrate ntawm 150 hli yog paub tab ntau tshaj li ntawm 200 hli, lub substrate zoo yog zoo dua, thiab cov impurity tswj theem ntawm 150 hli graphite cov tshuaj tiv thaiv chamber yog zoo dua.
2.4 Epitaxial wafer nto roughness
Daim duab 6 qhia txog AFM cov duab ntawm qhov chaw ntawm 150 hli thiab 200 hli SiC epitaxial wafers. Nws tuaj yeem pom los ntawm daim duab uas cov hauv paus hniav txhais tau hais tias square roughness Ra ntawm 150 hli thiab 200 hli epitaxial wafers yog 0.129 nm thiab 0.113 nm feem, thiab saum npoo ntawm epitaxial txheej yog du yam tsis muaj qhov pom tseeb macro-kauj ruam aggregation tshwm sim. Qhov tshwm sim no qhia tau hais tias kev loj hlob ntawm cov txheej txheem epitaxial ib txwm tswj cov kauj ruam khiav txoj kev loj hlob thaum lub sij hawm tag nrho cov txheej txheem epitaxial, thiab tsis muaj kauj ruam aggregation tshwm sim. Nws tuaj yeem pom tau tias los ntawm kev siv cov txheej txheem kev loj hlob zoo ntawm epitaxial, cov txheej txheem du epitaxial tuaj yeem tau txais ntawm 150 mm thiab 200 mm low-angle substrates.
3 Kev xaus
Lub 150 hli thiab 200 hli 4H-SiC homogeneous epitaxial wafers tau ua tiav npaj rau hauv tsev substrates siv tus kheej-tsim 200 hli SiC epitaxial loj hlob cov cuab yeej, thiab cov txheej txheem homogeneous epitaxial haum rau 150 hli thiab 200 hli tau tsim. Qhov kev loj hlob ntawm epitaxial tuaj yeem loj dua 60 μm / h. Thaum ua tau raws li qhov yuav tsum tau muaj kev kub ceev epitaxy, lub epitaxial wafer zoo yog zoo heev. Lub thickness uniformity ntawm 150 hli thiab 200 hli SiC epitaxial wafers yuav tswj tau nyob rau hauv 1.5%, lub concentration uniformity yog tsawg tshaj li 3%, tus tuag defect ceev yog tsawg tshaj li 0.3 particles / cm2, thiab epitaxial nto roughness paus txhais tau tias square Ra tsawg dua 0.15nm. Cov txheej txheem tseem ceeb ntawm cov epitaxial wafers yog nyob rau theem siab hauv kev lag luam.
Source: Electronic Industry Special Equipment
Sau: Xie Tianle, Li Ping, Yang Yu, Gong Xiaoliang, Ba Sai, Chen Guoqin, Wan Shengqiang
(48th Research Institute ntawm Tuam Tshoj Electronics Technology Group Corporation, Changsha, Hunan 410111)
Post lub sij hawm: Sep-04-2024