Silicon carbide muaj Mohs hardness ntawm 9.2-9.5, thib ob tsuas yog pob zeb diamond. Nws yog nkig heev thiab muaj cov pob txha tsis tshua muaj zog, thaum tseem muab cov khoom zoo heev -kub tsis kam, corrosion kuj, thiab hluav taws xob tsis kam. Txawm li cas los xij, nws yog qhov nyuaj thiab raug nqi ntau rau kev ua haujlwm, yuav tsum tau ua ntau yam xws li txiav, nqa -tawm, etching, thiab polishing. Kev ua tau zoo ncaj qha cuam tshuam rau qhov kev poob qis, tiv taus qib voltage, thiab kev pabcuam lub neej ntawm cov khoom siv fais fab. Tam sim no, hlau txiav yog dav siv vim nws tus nqi qis, cov cuab yeej siv yooj yim, thiab tsim nyog rau kev tsim khoom loj, thiab cov cuab yeej txiav pob zeb diamond kuj tseem yooj yim kom tau txais. Txawm li cas los xij, xaim txiav ua rau cov khoom poob ntau thiab muaj kev ua haujlwm tsawg heev.
Cov khoom poob los ntawm cov hlau txiav
Thaum lub sij hawm xaim txiav, qhov siab - txav ceev ntawm cov hlau txiav tsis tsuas yog ua kom poob nrog lub kerf dav sib npaug ntawm txoj kab uas hla; vim hais tias wafer nto npaj los ntawm hlau txiav yog ntxhib heev, tom qab sib tsoo thiab polishing thiab lwm yam txheej txheem tiav kuj yuav tsum tau. Thaum kawg, cov khoom poob tuaj yeem ncav cuag 30% -50% ntawm tag nrho cov khoom siv raw. Cov txheej txheem ntau- xov hlau sawing kuj yuav tsum muaj cov kev daws teeb meem kom txias lub kerf thiab ntxuav cov khib nyiab, tsim cov silicon ntau ntau- muaj cov kua dej pov tseg. Cov micro/nano- nplai cov khoom nyob rau hauv nws nyuaj rau flocculate thiab nyuaj rau rov ua dua, ua rau muaj kev cuam tshuam rau ib puag ncig.
Laser Lift-Tawm: Ua qhov "Kev phais tsis pom" Hauv Crystal
Laser nqa-tawm yog txheej txheem tseem ceeb rau SiC slicing thiab belongs rau kev hloov kho sab hauv thiab txheej txheej -splitting processing technology. Nws lub hauv paus ntsiab lus tseem ceeb yog laser sab hauv tsom kev hloov kho ntxiv rau sab nraud - quab yuam kev sib cais.
Schematic daim duab ntawm SiC siv lead ua laser nqa-tawm tshuab
Thawj theem yog kev hloov kho sab hauv. Siv lub ultrahigh nkag mus thiab tsom cov yam ntxwv ntawm ultrashort-pulse lasers, lub laser tsom xam yog precisely tswj los ntawm ib tug kho qhov muag txoj kev thiab tsom mus rau ib tug preset qhov tob nyob rau hauv lub silicon carbide wafer. Tom qab siab- lub zog laser tsom rau hauv lub wafer, cov khoom siv silicon carbide hauv zos tau dhau los ntawm kev sib txawv ntawm cov lattice, kev hloov pauv theem, thiab microcrack propagation, tsim cov txheej txheem hloov kho tas li. Lub zog txhua yam ntawm cov txheej txheem hloov kho yog qis dua li ntawm cov khoom siv substrate, thiab tsis muaj cov cim ua tiav ntawm qhov chaw, paub txog qhov tsis pom kev hloov kho. Qhov thib ob theem yog kev sib cais. Los ntawm mechanical micro- nro, gas blowing, los yog tensile sab nraud quab yuam, lub wafer yog precisely sib cais raws lub sab hauv hloov txheej, ua tiav lossless txiav thiab sib cais ntawm tag nrho cov wafer.
Tsis zoo li ib txwm siv hlau txiav, tsis yog- tiv tauj laser nqa- tawm tshuab tuaj yeem zam cov teeb meem xws li txiav cov cuab yeej hnav thiab SiC wafer tsis ua haujlwm los ntawm cov neeg kho tshuab kev ntxhov siab, yog li ua tiav qhov siab - zoo thiab siab - precision nqa- tawm. Laser nqa-tawm thev naus laus zis txhim kho kev ua haujlwm zoo thiab zoo ntawm silicon carbide wafers thiab txo cov nqi tsim khoom ntawm silicon carbide substrates. Nws muaj cov txiaj ntsig zoo ntawm kev ua haujlwm siab ntau lawm thiab cov khoom siv tsawg. Laser nqa- tawm muaj me me hloov txheej txheej, uas tuaj yeem txhim kho kev siv cov khoom siv thaum lub sij hawm npaj silicon carbide wafer. Kev ua tiav qib siab - zoo thiab siab - nqa kev ua tau zoo- tawm ntawm silicon carbide wafers yuav tsum tau tawg los ntawm kev tsis sib haum xeeb thiab siab - tus nqi txwv, thiab txhawb kev lag luam kev lag luam uas cov khoom siv silicon carbide hloov silicon substrates. Qhov cuam tshuam ib puag ncig ntawm laser nqa-tawm thev naus laus zis kuj tseem ceeb. Hauv cov txheej txheem txiav ib txwm, cov teeb meem ntawm kev txiav cov kua dej thiab plua plav paug yog qhov hnyav heev, thaum laser nqa-tawm, raws li cov txheej txheem tsis yog{19}}, tuaj yeem txo qis kev lag luam pov tseg. Ua ke nrog kev ua tau zoo ntawm cov khoom siv silicon carbide hauv kev hloov pauv hluav taws xob, cov thev naus laus zis no pab lub ntiaj teb cov pa roj carbon nruab nrab lub hom phiaj los ntawm ob qho tib si kev tsim khoom thiab daim ntawv thov xaus.
Ntiaj teb no haiv neeg: Cov xwm txheej tam sim no ntawm Laser Lift-Off Technology Development
Silicon carbide wafers tab tom txhim kho mus rau qhov loj dua, thiab laser nqa-tawm txiav tshuab tau nthuav dav. Laser wavelength, mem tes zog, tsom qhov tob, thiab scanning spacing yog cov tseem ceeb tsis uas txiav txim siab qhov txuas ntxiv thiab uniformity ntawm cov txheej txheem hloov kho . 532 nm thiab 1064 nm ultrafast lasers muaj kev nkag tau zoo heev rau hauv silicon carbide, thiab qhov chaw tsom me me. Cov txheej txheej hloov kho tuaj yeem tswj tau meej ntawm 10-30 μm, thiab hloov cov kab nrib pleb nthuav tawm hauv cov lus qhia yam tsis muaj diffusing rau hauv cov cuab yeej ua haujlwm. Los ntawm dynamic polarization tswj thiab beam shaping thev naus laus zis, morphology ntawm cov txheej txheem hloov kho tuaj yeem ua kom zoo, txiav flatness tuaj yeem txhim kho, thiab wafer splitting warpage tuaj yeem ua tau zoo. Kev tshawb fawb hauv tsev tsom mus rau kev ua cov khoom sib xws rau cov loj-size wafers, qis-kev nyuaj siab ntawm ultra-thin wafers (50–100 μm), thiab optimization ntawm nqaim{14}}spacing tuag txiav tshuab. Ua tiav lub tshuab laser nqa-tawm txiav ntawm 8-inch silicon carbide wafers tau ua tiav. Raws li cov txheej txheem ua tau zoo, kev txiav txoj kev dav tuaj yeem raug txo kom tsawg li ntawm 20 μm, cov txiaj ntsig tuag ntau dua 98%, thiab kev ua haujlwm ib leeg-wafer tau nce ntau dua 30% piv nrog cov txheej txheem ib txwm siv, daws qhov teeb meem uas ib txwm hloov kho tsis tuaj yeem hloov mus rau tuab wafer ua. Tau qhov twg los: Shuoke Crystal.
Nyob rau hauv siv lead ua lift-tawm thev naus laus zis, thaum ntxov li xyoo 1985, Asmeskas cov kws tshawb fawb tau pom tias cov txheej nyias nyias tuaj yeem raug tshem tawm ntawm Si thiab GaAs wafers nyob rau hauv qhov kev txiav txim ntawm qhov seem tensile kev ntxhov siab hauv txheej txheej kev ntxhov siab. Txawm li cas los xij, thaum ntxov siv lead ua lift-tawm cov txheej txheem sim tau nyuaj rau kev tswj vim tias thaum qhov kev ntxhov siab mus txog qhov pib txiav txim siab los ntawm wafer tawg toughness, cov kab nrib pleb yuav spontaneously tsim thiab propagate random, ua rau uneven lift- tawm txheej thickness los yog fragmentation.
IBM tau tsim ib qho kev tswj nqa nqa -tawm thev naus laus zis. Txoj kev no tsim cov txheej txheem traction ntxiv los siv cov quab yuam sab nraud los ua kom tawg thiab taw qhia kev tawg tawm, thiab tseem tsim cov qauv theoretical rau kev sib raug zoo ntawm qhov tseem ceeb ntawm kev ntxhov siab thiab spalling txheej thickness, muab kev taw qhia rau cov txheej txheem optimization. Tsis tas li ntawd, wafer-theem Si, GaN ib leeg siv lead ua, nrog rau III-V hnub ci hlwb, kev sib koom ua ke, LEDs, thiab lwm yam khoom siv semiconductor, txhua tus tuaj yeem siv cov thev naus laus zis no kom ua tiav kev tswj nqa nqa - tawm.
Nyob rau hauv cov nqe lus ntawm industrialization technology, lub teb chaws Yelemees lub Siltectra txias split tshuab thiab Nyiv lub Disco laser hloov txheej txheem tuaj yeem tswj SiC slicing khoom poob rau hauv 60 μm thiab tau ua tiav 8-inch wafer pawg ntau lawm; Cov chaw tsim khoom nyob sab Europe thiab Asmeskas monopolize UV excimer lub teeb qhov chaw thiab tau ntev ua tus thawj tswj hwm kev nqa khoom- tawm khoom lag luam rau Micro-LED epitaxial wafers.
Nyob rau hauv xyoo tas los no, kev nce qib hauv tsev yog qhov tseem ceeb. Pab pawg tshawb fawb los ntawm Huazhong University of Science thiab Technology thiab CETC tau kov yeej SiC kev hloov kho sab hauv thiab tawg kev tswj hwm kev tswj hwm thev naus laus zis. Cov lag luam xws li Han's Laser thiab HGTECH tau ua tiav hauv cheeb tsam ntawm UV laser nqa- tawm cov khoom siv, thiab cov khoom siv hauv tsev tau nkag mus rau hauv cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob. Tam sim no, domestic 6-inch SiC nqa- tawm txheej txheem qhia tau ze rau thoob ntiaj teb, tab sis lub zog sib xws ntawm 8-inch loj- loj puv wafers kuj tsis zoo, thiab cov teeb meem tawg ntawm N- hom silicon carbide tsis tau daws tag nrho. High-power UV lasers thiab high-precision optical modules tseem cia siab rau kev xa khoom.