1. Kev Taw Qhia
Txawm hais tias muaj ntau xyoo ntawm kev tshawb fawb, heteroepitaxial 3C-SiC loj hlob ntawm silicon substrates tseem tsis tau ua tiav qhov zoo crystal rau kev siv hluav taws xob hauv kev lag luam. Kev loj hlob feem ntau yog ua rau Si (100) lossis Si (111) substrates, txhua qhov nthuav tawm cov teeb meem sib txawv: anti-phase domains rau (100) thiab tawg rau (111). Thaum [111]-oriented zaj duab xis qhia txog cov yam ntxwv zoo xws li txo qhov tsis zoo, txhim kho qhov chaw morphology, thiab qis dua kev ntxhov siab, lwm txoj kev taw qhia zoo li (110) thiab (211) tseem tsis tau kawm. Cov ntaub ntawv uas twb muaj lawm qhia tias qhov zoo tshaj plaws kev loj hlob tej zaum yuav yog kev taw qhia tshwj xeeb, ua rau kev tshawb nrhiav tsis meej. Qhov tseem ceeb, kev siv cov khoom siv Si siab dua-Miller-index (piv txwv li, (311), (510)) rau 3C-SiC heteroepitaxy yeej tsis tau tshaj tawm, tawm hauv chav tseem ceeb rau kev tshawb fawb tshawb nrhiav txog kev loj hlob raws li kev taw qhia.
2. Kev sim
Cov txheej 3C-SiC tau tso rau ntawm atmospheric-pressure chemical vapor deposition (CVD) siv SiH4/C3H8/H2 precursor gases. Cov substrates yog 1 cm² Si wafers nrog ntau yam kev taw qhia: (100), (111), (110), (211), (311), (331), (510), (553), thiab (995). Tag nrho cov substrates yog on-axis tshwj tsis yog rau (100), qhov twg 2 ° off-cut wafers tau kuaj ntxiv. Kev ntxuav ua ntej kev loj hlob suav nrog ultrasonic degreasing hauv methanol. Cov txheej txheem kev loj hlob suav nrog kev tshem tawm oxide los ntawm H2 annealing ntawm 1000 ° C, ua raws li tus txheej txheem ob kauj ruam: carburization rau 10 feeb ntawm 1165 ° C nrog 12 sccm C3H8, tom qab ntawd epitaxy rau 60 feeb ntawm 1350 ° C (C / Si piv = 4) siv 1.5 sccm SiH4 thiab 2 sccm C3H8. Txhua qhov kev loj hlob suav nrog plaub mus rau tsib qhov kev taw qhia Si sib txawv, nrog tsawg kawg ib (100) wafer siv.
3. Cov Txiaj Ntsig thiab Kev Sib Tham
Cov morphology ntawm 3C-SiC txheej uas loj hlob ntawm ntau yam Si substrates (Daim Duab 1) qhia txog cov yam ntxwv ntawm qhov chaw thiab qhov roughness sib txawv. Pom tau, cov qauv uas loj hlob ntawm Si(100), (211), (311), (553), thiab (995) zoo li daim iav, thaum lwm tus muaj txij li mis nyuj ((331), (510)) mus rau qhov tsis muaj zog ((110), (111)). Cov nto du tshaj plaws (qhia txog qhov microstructure zoo tshaj plaws) tau txais ntawm (100)2° tawm thiab (995) substrates. Qhov zoo kawg nkaus, txhua txheej tseem tsis tawg tom qab txias, suav nrog 3C-SiC(111) uas feem ntau yooj yim ntxhov siab. Qhov loj me ntawm cov qauv tsawg yuav tiv thaiv kev tawg, txawm hais tias qee cov qauv tau pom tias bowing (30-60 μm deflection los ntawm qhov chaw mus rau ntug) pom tau hauv qab lub tshuab tsom iav ntawm 1000 × magnification vim muaj kev ntxhov siab thermal. Cov txheej txheem nkhaus siab uas loj hlob ntawm Si (111), (211), thiab (553) substrates tau pom cov duab concave qhia txog kev nyuaj siab tensile, xav tau kev sim thiab kev ua haujlwm theoretical ntxiv kom sib raug zoo nrog kev taw qhia crystallographic.
Daim Duab 1 qhia txog cov txiaj ntsig XRD thiab AFM (scanning ntawm 20 × 20 μ m2) ntawm cov txheej 3C-SC uas loj hlob ntawm Si substrates nrog cov kev taw qhia sib txawv.
Cov duab Atomic force microscopy (AFM) (Daim Duab 2) tau lees paub qhov kev soj ntsuam pom kev. Cov nqi ntawm cov cag-mean-square (RMS) tau lees paub qhov chaw du tshaj plaws ntawm (100) 2 ° tawm thiab (995) substrates, uas muaj cov qauv zoo li cov noob nrog 400-800 nm lateral dimensions. Cov txheej (110)-loj hlob yog qhov ntxhib tshaj plaws, thaum cov yam ntxwv ntev thiab / lossis sib luag nrog cov ciam teb ntse tshwm sim hauv lwm qhov kev taw qhia ((331), (510)). X-ray diffraction (XRD) θ-2θ scans (sau luv luv hauv Rooj 1) tau qhia txog kev ua tiav heteroepitaxy rau cov substrates qis-Miller-index, tshwj tsis yog Si (110) uas tau qhia txog kev sib xyaw 3C-SiC (111) thiab (110) peaks qhia txog polycrystallinity. Qhov kev sib xyaw ua ke no tau tshaj tawm yav dhau los rau Si (110), txawm hais tias qee qhov kev tshawb fawb tau pom tshwj xeeb (111)-taw qhia 3C-SiC, qhia tias kev loj hlob zoo yog qhov tseem ceeb. Rau Miller indices ≥5 ((510), (553), (995)), tsis muaj XRD peaks tau pom nyob rau hauv tus qauv θ-2θ configuration txij li cov dav hlau high-index no tsis-difffracting hauv qhov geometry no. Qhov tsis muaj cov low-index 3C-SiC peaks (piv txwv li, (111), (200)) qhia txog kev loj hlob ib leeg-crystalline, xav tau cov qauv tilting kom pom diffraction los ntawm cov dav hlau qis-index.
Daim Duab 2 qhia txog kev xam lub kaum sab xis hauv cov qauv siv lead ua CFC.
Cov kaum sab xis crystallographic xam ntawm cov dav hlau siab-index thiab qis-index (Rooj 2) qhia txog kev tsis sib haum xeeb loj (> 10 °), piav qhia lawv tsis muaj nyob rau hauv tus qauv θ-2θ scans. Yog li ntawd, kev tshuaj xyuas tus lej ncej tau ua rau ntawm tus qauv (995)-taw qhia vim nws cov qauv granular txawv txawv (tej zaum los ntawm kev loj hlob ntawm columnar lossis twinning) thiab qhov tsis sib xws tsawg. Cov lej ncej (111) (Daim Duab 3) los ntawm Si substrate thiab 3C-SiC txheej yuav luag zoo ib yam, lees paub qhov kev loj hlob epitaxial yam tsis muaj twinning. Qhov chaw nruab nrab tshwm sim ntawm χ ≈15 °, phim lub kaum sab xis (111)-(995). Peb qhov chaw sib npaug sib npaug tau tshwm sim ntawm qhov chaw xav tau (χ = 56.2 ° / φ = 269.4 °, χ = 79 ° / φ = 146.7 ° thiab 33.6 °), txawm hais tias qhov chaw tsis muaj zog tsis tau kwv yees ntawm χ = 62 ° / φ = 93.3 ° xav tau kev tshawb nrhiav ntxiv. Qhov zoo ntawm cov pob zeb crystalline, uas ntsuas los ntawm qhov dav ntawm qhov chaw hauv φ-scans, zoo li muaj kev cia siab, txawm hais tias kev ntsuas cov kab nkhaus rocking yog qhov xav tau rau kev ntsuas. Cov lej ncej rau (510) thiab (553) cov qauv tseem yuav tsum tau ua kom tiav kom paub meej tias lawv qhov xwm txheej epitaxial xav tau.
Daim Duab 3 qhia txog daim duab XRD ncov uas tau kaw cia rau ntawm tus qauv (995), uas qhia txog (111) dav hlau ntawm Si substrate (a) thiab 3C-SiC txheej (b).
4. Xaus Lus
Kev loj hlob ntawm Heteroepitaxial 3C-SiC tau ua tiav ntawm feem ntau ntawm Si orientations tshwj tsis yog (110), uas tau tsim cov khoom siv polycrystalline. Si (100) 2 ° tawm thiab (995) substrates tsim cov txheej du tshaj plaws (RMS <1 nm), thaum (111), (211), thiab (553) tau qhia txog kev khoov tseem ceeb (30-60 μm). Cov substrates siab-index xav tau kev piav qhia XRD siab heev (piv txwv li, cov duab ncej) kom paub meej epitaxy vim tsis muaj θ-2θ peaks. Kev ua haujlwm txuas ntxiv suav nrog kev ntsuas nkhaus rocking, Raman kev ntxhov siab tsom xam, thiab nthuav dav mus rau lwm qhov kev taw qhia siab-index kom ua tiav qhov kev tshawb fawb tshawb nrhiav no.
Ua ib lub chaw tsim khoom uas sib koom ua ke, XKH muab cov kev pabcuam ua haujlwm raws li kev cai nrog cov khoom siv silicon carbide, muab cov hom txheem thiab cov hom tshwj xeeb suav nrog 4H/6H-N, 4H-Semi, 4H/6H-P, thiab 3C-SiC, muaj nyob rau hauv cov kab uas hla ntawm 2-nti mus rau 12-nti. Peb qhov kev txawj ntse hauv kev loj hlob ntawm cov siv lead ua, kev ua haujlwm kom raug, thiab kev ruaj ntseg zoo ua kom ntseeg tau tias muaj cov kev daws teeb meem rau cov khoom siv hluav taws xob fais fab, RF, thiab cov ntawv thov tshiab.
Lub sijhawm tshaj tawm: Lub Yim Hli-08-2025