Raws li pom hauv daim duab 3, muaj peb txoj kev tseem ceeb uas tsom mus rau kev muab SiC ib leeg siv lead ua ke nrog qhov zoo thiab ua haujlwm tau zoo: liquid phase epitaxy (LPE), physical vapor transport (PVT), thiab high-temperature chemical vapor deposition (HTCVD). PVT yog ib txoj kev tsim cov SiC ib leeg siv lead ua ke, uas siv dav hauv cov chaw tsim khoom loj wafer.
Txawm li cas los xij, tag nrho peb txoj kev no tab tom hloov pauv sai thiab tsim kho tshiab. Tseem tsis tau paub meej tias txoj kev twg yuav raug siv dav hauv yav tom ntej. Tshwj xeeb, cov khoom siv SiC zoo uas tsim los ntawm kev loj hlob ntawm cov kua dej tau tshaj tawm hauv xyoo tas los no, kev loj hlob ntawm SiC hauv cov kua dej xav tau qhov kub qis dua li ntawm cov txheej txheem sublimation lossis deposition, thiab nws qhia tau tias muaj kev ua tau zoo hauv kev tsim cov khoom siv P-hom SiC (Rooj 3) [33, 34].
Daim Duab 3: Daim duab qhia txog peb txoj kev loj hlob ntawm SiC ib leeg siv lead ua ke: (a) epitaxy theem kua; (b) kev thauj mus los ntawm cov pa dej; (c) kev tso cov pa tshuaj lom neeg kub siab
Rooj 3: Kev sib piv ntawm LPE, PVT thiab HTCVD rau kev loj hlob SiC ib leeg siv lead ua [33, 34]
Kev loj hlob ntawm cov tshuaj yog ib qho thev naus laus zis txheem rau kev npaj cov khoom sib xyaw ua ke [36]. Txij li xyoo 1960, cov kws tshawb fawb tau sim tsim cov siv lead ua hauv cov tshuaj [37]. Thaum cov thev naus laus zis tau tsim kho, qhov kev sib xyaw ua ke ntawm qhov chaw loj hlob tuaj yeem tswj tau zoo, uas ua rau txoj kev daws teeb meem yog ib qho thev naus laus zis zoo rau kev tau txais cov khoom siv lead ua ke zoo.
Rau kev loj hlob ntawm SiC ib leeg siv lead ua ke, qhov chaw Si yog los ntawm Si yaj uas ntshiab heev thaum lub graphite crucible ua haujlwm ob lub hom phiaj: cua sov thiab C solute qhov chaw. SiC ib leeg siv lead ua ke yuav loj hlob ntau dua nyob rau hauv qhov sib piv stoichiometric zoo tagnrho thaum qhov sib piv ntawm C thiab Si nyob ze rau 1, qhia txog qhov qis dua qhov tsis zoo [28]. Txawm li cas los xij, ntawm qhov siab atmospheric, SiC tsis qhia qhov melting point thiab decomposes ncaj qha los ntawm vaporization ntawm qhov kub tshaj li ntawm 2,000 ° C. SiC yaj, raws li kev cia siab theoretical, tsuas yog tuaj yeem tsim nyob rau hauv qhov hnyav yuav pom los ntawm daim duab theem binary Si-C (Daim Duab 4) uas ntawm qhov kub thiab txias gradient thiab cov kua system. Qhov siab dua C hauv Si yaj sib txawv ntawm 1at.% txog 13at.%. Tus tsav tsheb C supersaturation, qhov ceev dua qhov kev loj hlob, thaum qis C lub zog ntawm kev loj hlob yog C supersaturation uas yog dominated siab ntawm 109 Pa thiab kub tshaj 3,200 ° C. Nws tuaj yeem ua rau muaj qhov chaw du [22, 36-38]. Qhov kub ntawm 1,400 thiab 2,800 °C, qhov solubility ntawm C hauv Si yaj sib txawv ntawm 1at.% txog 13at.%. Lub zog tsav tsheb ntawm kev loj hlob yog C supersaturation uas yog dominated los ntawm qhov kub thiab txias gradient thiab cov kua system. Qhov siab dua C supersaturation, qhov ceev dua qhov kev loj hlob, thaum C supersaturation qis tsim qhov chaw du [22, 36-38].
Daim Duab 4: Daim duab qhia txog theem binary Si-C [40]
Kev siv cov hlau hloov pauv lossis cov hlau tsis tshua muaj hauv ntiaj teb tsis yog tsuas yog txo qhov kub ntawm kev loj hlob xwb tab sis zoo li yog tib txoj hauv kev los txhim kho cov pa roj carbon solubility hauv Si yaj. Kev ntxiv cov hlau hloov pauv, xws li Ti [8, 14-16, 19, 40-52], Cr [29, 30, 43, 50, 53-75], Co [63, 76], Fe [77-80], thiab lwm yam lossis cov hlau tsis tshua muaj hauv ntiaj teb, xws li Ce [81], Y [82], Sc, thiab lwm yam rau Si yaj tso cai rau cov pa roj carbon solubility ntau dua 50at.% hauv lub xeev ze rau thermodynamic equilibrium. Ntxiv mus, LPE txheej txheem yog qhov zoo rau P-hom doping ntawm SiC, uas tuaj yeem ua tiav los ntawm kev sib xyaw Al rau hauv
cov kuab tshuaj [50, 53, 56, 59, 64, 71-73, 82, 83]. Txawm li cas los xij, kev koom ua ke ntawm Al ua rau muaj kev nce ntxiv ntawm qhov resistivity ntawm P-hom SiC ib leeg siv lead ua ke [49, 56]. Sib nrug los ntawm N-hom kev loj hlob nyob rau hauv nitrogen doping,
Feem ntau kev loj hlob ntawm cov tshuaj tau mus rau hauv huab cua inert gas. Txawm hais tias helium (He) kim dua li argon, nws tau nyiam los ntawm ntau tus kws tshawb fawb vim nws qhov viscosity qis dua thiab thermal conductivity siab dua (8 zaug ntawm argon) [85]. Tus nqi tsiv teb tsaws chaw thiab Cr cov ntsiab lus hauv 4H-SiC zoo sib xws hauv He thiab Ar huab cua, nws tau ua pov thawj tias kev loj hlob hauv Heres ua rau muaj kev loj hlob ntau dua li kev loj hlob hauv Ar vim yog qhov cua sov loj dua ntawm tus tuav noob [68]. Nws cuam tshuam cov voids tsim hauv cov siv lead ua loj hlob thiab spontaneous nucleation hauv cov tshuaj, tom qab ntawd, cov morphology du tuaj yeem tau txais [86].
Tsab ntawv no tau qhia txog kev tsim kho, kev siv, thiab cov khoom ntawm SiC cov khoom siv, thiab peb txoj hauv kev tseem ceeb rau kev loj hlob SiC ib leeg siv lead ua ke. Hauv cov ntu hauv qab no, cov txheej txheem kev loj hlob ntawm cov tshuaj tam sim no thiab cov yam ntxwv tseem ceeb tau raug tshuaj xyuas. Thaum kawg, ib qho kev xav tau raug npaj uas tau tham txog cov teeb meem thiab cov haujlwm yav tom ntej txog kev loj hlob ntawm SiC ib leeg siv lead ua ke los ntawm txoj kev daws teeb meem.
Lub sijhawm tshaj tawm: Lub Xya Hli-01-2024