Cov txheej txheem yooj yim ntawmSiCKev loj hlob ntawm cov siv lead ua ke tau muab faib ua sublimation thiab decomposition ntawm cov khoom siv raw ntawm qhov kub siab, kev thauj mus los ntawm cov khoom siv roj theem nyob rau hauv qhov kev ua ntawm qhov kub thiab txias, thiab kev loj hlob ntawm cov khoom siv roj theem ntawm cov noob siv lead ua ke. Raws li qhov no, sab hauv ntawm lub crucible tau muab faib ua peb ntu: thaj chaw khoom siv raw, chav loj hlob thiab noob siv lead ua ke. Ib qho qauv simulation lej tau kos raws li qhov tseeb resistiveSiCcov khoom siv loj hlob siv lead ua ib leeg (saib Daim Duab 1). Hauv kev xam: hauv qab ntawmlub khob hliav qabyog 90 hli deb ntawm hauv qab ntawm lub cua sov sab, qhov kub saum toj kawg nkaus ntawm lub crucible yog 2100 ℃, lub cheeb ntawm cov khoom siv raw yog 1000 μm, qhov porosity yog 0.6, lub siab loj hlob yog 300 Pa, thiab lub sijhawm loj hlob yog 100 teev. Lub thickness ntawm PG yog 5 hli, lub cheeb yog sib npaug rau lub cheeb sab hauv ntawm lub crucible, thiab nws nyob 30 hli saum toj ntawm cov khoom siv raw. Cov txheej txheem sublimation, carbonization, thiab recrystallization ntawm thaj chaw khoom siv raw raug txiav txim siab hauv kev xam, thiab qhov kev cuam tshuam ntawm PG thiab cov tshuaj theem roj tsis raug txiav txim siab. Cov kev ntsuas khoom siv lub cev ntsig txog kev xam tau qhia hauv Rooj 1.
Daim Duab 1 Qauv xam zauv simulation. (a) Qauv teb thermal rau kev simulation kev loj hlob ntawm siv lead ua; (b) Kev faib thaj chaw sab hauv ntawm lub crucible thiab cov teeb meem lub cev cuam tshuam
Rooj 1 Qee cov kev ntsuas lub cev siv rau hauv kev xam
Daim Duab 2(a) qhia tau hais tias qhov kub ntawm cov qauv uas muaj PG (hu ua qauv 1) siab dua li ntawm cov qauv uas tsis muaj PG (hu ua qauv 0) hauv qab PG, thiab qis dua li ntawm cov qauv 0 saum PG. Qhov kub tag nrho nce ntxiv, thiab PG ua haujlwm ua tus neeg sawv cev tiv thaiv cua sov. Raws li Daim Duab 2(b) thiab 2(c), qhov kub axial thiab radial ntawm cov qauv 1 hauv thaj chaw raw khoom me dua, qhov kub faib yog sib npaug ntau dua, thiab sublimation ntawm cov khoom tiav ntau dua. Tsis zoo li thaj chaw raw khoom, Daim Duab 2(c) qhia tau hais tias qhov kub radial ntawm cov noob siv lead ua ntawm cov qauv 1 loj dua, uas tej zaum yuav yog vim muaj qhov sib txawv ntawm cov hom kev hloov cua sov sib txawv, uas pab cov siv lead ua loj hlob nrog lub convex interface. Hauv Daim Duab 2(d), qhov kub ntawm ntau qhov chaw hauv lub crucible qhia txog qhov sib txawv nce ntxiv thaum kev loj hlob nce ntxiv, tab sis qhov kub sib txawv ntawm cov qauv 0 thiab cov qauv 1 maj mam txo qis hauv thaj chaw raw khoom thiab maj mam nce hauv chav loj hlob.
Daim Duab 2 Kev faib tawm kub thiab kev hloov pauv hauv lub crucible. (a) Kev faib tawm kub sab hauv lub crucible ntawm cov qauv 0 (sab laug) thiab cov qauv 1 (sab xis) ntawm 0 teev, chav tsev: ℃; (b) Kev faib tawm kub ntawm kab nruab nrab ntawm lub crucible ntawm cov qauv 0 thiab cov qauv 1 los ntawm hauv qab ntawm cov khoom siv raw mus rau cov noob siv lead ua ntawm 0 teev; (c) Kev faib tawm kub ntawm qhov chaw mus rau ntug ntawm lub crucible ntawm qhov chaw noob siv lead ua (A) thiab qhov chaw khoom siv raw (B), nruab nrab (C) thiab hauv qab (D) ntawm 0 teev, kab rov tav r yog lub vojvoog noob siv lead ua rau A, thiab lub vojvoog thaj chaw khoom siv raw rau B ~ D; (d) Kev hloov pauv kub ntawm qhov chaw nruab nrab ntawm sab saud (A), qhov chaw khoom siv raw (B) thiab nruab nrab (C) ntawm chav loj hlob ntawm cov qauv 0 thiab cov qauv 1 ntawm 0, 30, 60, thiab 100 teev.
Daim Duab 3 qhia txog kev thauj khoom ntawm lub sijhawm sib txawv hauv lub crucible ntawm cov qauv 0 thiab cov qauv 1. Qhov nrawm ntawm cov khoom siv roj hauv thaj chaw khoom siv raw thiab chav loj hlob nce nrog qhov nce ntawm qhov chaw, thiab kev thauj khoom tsis muaj zog thaum kev loj hlob nce mus. Daim Duab 3 kuj qhia tau tias nyob rau hauv cov xwm txheej simulation, cov khoom siv raw ua ntej graphitizes ntawm phab ntsa sab ntawm lub crucible thiab tom qab ntawd rau hauv qab ntawm lub crucible. Tsis tas li ntawd, muaj recrystallization ntawm qhov chaw ntawm cov khoom siv raw thiab nws maj mam tuab thaum kev loj hlob nce mus. Daim Duab 4(a) thiab 4(b) qhia tau tias qhov nrawm ntawm cov khoom siv raw hauv cov khoom siv raw txo qis thaum kev loj hlob nce mus, thiab qhov nrawm ntawm cov khoom siv ntawm 100 teev yog kwv yees li 50% ntawm lub sijhawm pib; txawm li cas los xij, qhov nrawm yog qhov loj ntawm ntug vim yog graphitization ntawm cov khoom siv raw, thiab qhov nrawm ntawm ntug yog ntau dua 10 npaug ntawm qhov nrawm hauv thaj chaw nruab nrab ntawm 100 teev; ntxiv rau, qhov cuam tshuam ntawm PG hauv cov qauv 1 ua rau cov khoom siv ntws nrawm hauv thaj chaw khoom siv raw ntawm cov qauv 1 qis dua li ntawm cov qauv 0. Hauv Daim Duab 4 (c), cov khoom siv ntws hauv ob qho chaw khoom siv raw thiab chav loj hlob maj mam qaug zog thaum kev loj hlob nce qib, thiab cov khoom siv ntws hauv thaj chaw khoom siv raw txuas ntxiv txo qis, uas yog tshwm sim los ntawm kev qhib ntawm cov pa ntws channel ntawm ntug ntawm crucible thiab kev thaiv ntawm recrystallization ntawm sab saum toj; hauv chav loj hlob, cov khoom siv ntws nrawm ntawm cov qauv 0 txo qis sai sai hauv thawj 30 teev mus rau 16%, thiab tsuas yog txo qis 3% hauv lub sijhawm tom qab, thaum cov qauv 1 tseem ruaj khov thoob plaws hauv cov txheej txheem loj hlob. Yog li ntawd, PG pab kom ruaj khov cov khoom siv ntws nrawm hauv chav loj hlob. Daim Duab 4 (d) piv rau cov khoom siv ntws nrawm ntawm qhov loj hlob siv lead ua ntej. Thaum lub sijhawm pib thiab 100 teev, kev thauj khoom hauv thaj chaw loj hlob ntawm cov qauv 0 muaj zog dua li ntawm cov qauv 1, tab sis yeej ib txwm muaj thaj chaw ntws siab ntawm ntug ntawm cov qauv 0, uas ua rau muaj kev loj hlob ntau dhau ntawm ntug. Qhov muaj PG hauv cov qauv 1 ua rau muaj qhov xwm txheej no zoo.
Daim Duab 3 Cov khoom siv ntws hauv lub crucible. Cov kab streamlines (sab laug) thiab cov vectors ceev (sab xis) ntawm kev thauj khoom siv roj hauv cov qauv 0 thiab 1 ntawm lub sijhawm sib txawv, chav tsev vector ceev: m/s
Daim Duab 4 Kev Hloov Pauv ntawm Cov Khoom Siv Nqus. (a) Kev Hloov Pauv ntawm Cov Khoom Siv Nqus hauv Nruab Nrab ntawm Cov Khoom Siv Raw ntawm Qauv 0 ntawm 0, 30, 60, thiab 100 teev, r yog lub vojvoog ntawm thaj chaw khoom siv raw; (b) Kev Hloov Pauv ntawm Cov Khoom Siv Nqus hauv Nruab Nrab ntawm Cov Khoom Siv Raw ntawm Qauv 1 ntawm 0, 30, 60, thiab 100 teev, r yog lub vojvoog ntawm thaj chaw khoom siv raw; (c) Kev Hloov Pauv ntawm Cov Khoom Siv Raw hauv Chav Loj Hlob (A, B) thiab sab hauv cov khoom siv raw (C, D) ntawm Cov Qauv 0 thiab 1 dhau sijhawm; (d) Kev Hloov Pauv ntawm Cov Khoom Siv Raw ze ntawm qhov chaw siv lead ua noob ntawm Cov Qauv 0 thiab 1 ntawm 0 thiab 100 teev, r yog lub vojvoog ntawm Cov Khoom Siv lead ua noob.
C/Si cuam tshuam rau qhov ruaj khov ntawm cov pob zeb siv lead ua thiab qhov tsis zoo ntawm SiC siv lead ua loj hlob. Daim duab 5(a) piv rau qhov faib ntawm C/Si ntawm ob lub qauv thaum pib. Qhov sib piv ntawm C/Si maj mam txo qis los ntawm hauv qab mus rau saum lub crucible, thiab qhov sib piv ntawm C/Si ntawm cov qauv 1 yeej ib txwm siab dua li ntawm cov qauv 0 ntawm ntau qhov chaw sib txawv. Daim duab 5(b) thiab 5(c) qhia tias qhov sib piv ntawm C/Si maj mam nce nrog kev loj hlob, uas cuam tshuam nrog kev nce ntawm qhov kub thiab txias sab hauv theem tom qab ntawm kev loj hlob, kev txhim kho ntawm cov khoom siv raw graphitization, thiab kev cuam tshuam ntawm Si cov khoom hauv theem roj nrog lub graphite crucible. Hauv Daim duab 5(d), qhov sib piv ntawm C/Si ntawm cov qauv 0 thiab cov qauv 1 txawv heev hauv qab PG (0, 25 hli), tab sis txawv me ntsis saum PG (50 hli), thiab qhov sib txawv maj mam nce thaum nws mus txog qhov siv lead ua. Feem ntau, qhov sib piv ntawm C/Si ntawm cov qauv 1 siab dua, uas pab ua kom cov qauv siv lead ua ruaj khov thiab txo qhov muaj feem ntawm kev hloov pauv theem.
Daim Duab 5 Kev Faib Tawm thiab Kev Hloov Pauv ntawm C/Si piv. (a) Kev Faib Tawm C/Si piv hauv cov khoom siv ntawm cov qauv 0 (sab laug) thiab cov qauv 1 (sab xis) ntawm 0 teev; (b) C/Si piv ntawm qhov deb sib txawv ntawm txoj kab nruab nrab ntawm cov khoom siv ntawm cov qauv 0 ntawm lub sijhawm sib txawv (0, 30, 60, 100 teev); (c) C/Si piv ntawm qhov deb sib txawv ntawm txoj kab nruab nrab ntawm cov khoom siv ntawm cov qauv 1 ntawm lub sijhawm sib txawv (0, 30, 60, 100 teev); (d) Kev Sib Piv ntawm C/Si piv ntawm qhov deb sib txawv (0, 25, 50, 75, 100 hli) ntawm txoj kab nruab nrab ntawm cov khoom siv ntawm cov qauv 0 (kab khoom) thiab cov qauv 1 (kab dashed) ntawm lub sijhawm sib txawv (0, 30, 60, 100 teev).
Daim Duab 6 qhia txog kev hloov pauv ntawm txoj kab uas hla ntawm cov khoom siv raw thiab porosity ntawm cov cheeb tsam ntawm ob lub qauv. Daim duab qhia tau hais tias txoj kab uas hla ntawm cov khoom siv raw txo qis thiab qhov porosity nce ze ntawm phab ntsa crucible, thiab qhov porosity ntawm ntug txuas ntxiv mus ntxiv thiab txoj kab uas hla ntawm cov khoom siv particle txuas ntxiv mus txo qis thaum kev loj hlob zuj zus. Qhov siab tshaj plaws ntawm ntug porosity yog li 0.99 ntawm 100 h, thiab qhov tsawg kawg nkaus ntawm cov khoom siv particle yog li 300 μm. Txoj kab uas hla ntawm cov khoom siv particle nce thiab qhov porosity txo qis ntawm qhov saum npoo ntawm cov khoom siv raw, sib raug rau recrystallization. Lub thickness ntawm thaj chaw recrystallization nce ntxiv thaum kev loj hlob zuj zus, thiab qhov loj me ntawm cov khoom siv particle thiab porosity txuas ntxiv mus hloov pauv. Qhov siab tshaj plaws ntawm cov khoom siv particle ncav cuag ntau dua 1500 μm, thiab qhov tsawg kawg nkaus porosity yog 0.13. Tsis tas li ntawd, txij li thaum PG ua rau qhov kub ntawm thaj chaw khoom siv raw nce thiab cov roj supersaturation me me, qhov tuab ntawm recrystallization ntawm sab saud ntawm cov khoom siv raw ntawm qauv 1 yog me me, uas txhim kho tus nqi siv khoom siv raw.
Daim Duab 6 Kev hloov pauv ntawm lub cheeb tsam ntawm cov khoom me me (sab laug) thiab porosity (sab xis) ntawm thaj chaw raw khoom ntawm cov qauv 0 thiab cov qauv 1 ntawm ntau lub sijhawm sib txawv, chav tsev ntawm lub cheeb tsam ntawm cov khoom me me: μm
Daim Duab 7 qhia tau hais tias cov qauv 0 warps thaum pib ntawm kev loj hlob, uas tej zaum yuav muaj feem cuam tshuam nrog cov khoom siv ntau dhau los ntawm kev graphitization ntawm cov khoom siv raw ntug. Qib ntawm warping tsis muaj zog thaum lub sijhawm loj hlob tom qab, uas sib raug rau qhov kev hloov pauv ntawm cov khoom siv ntws ntawm pem hauv ntej ntawm kev loj hlob ntawm cov siv lead ua qauv 0 hauv Daim Duab 4 (d). Hauv cov qauv 1, vim yog qhov cuam tshuam ntawm PG, qhov sib txuas ntawm cov siv lead ua qauv tsis qhia warping. Tsis tas li ntawd, PG kuj ua rau qhov kev loj hlob ntawm cov qauv 1 qis dua li ntawm cov qauv 0. Lub thickness nruab nrab ntawm cov siv lead ua qauv 1 tom qab 100 teev tsuas yog 68% ntawm cov qauv 0.
Daim Duab 7 Kev hloov pauv ntawm cov qauv 0 thiab cov qauv 1 siv lead ua ke ntawm 30, 60, thiab 100 teev
Kev loj hlob ntawm cov siv lead ua tau ua tiav raws li cov txheej txheem ntawm kev sim ua lej. Cov siv lead ua uas loj hlob los ntawm cov qauv 0 thiab cov qauv 1 tau pom hauv Daim Duab 8 (a) thiab Daim Duab 8 (b), raws li. Cov siv lead ua ntawm cov qauv 0 qhia txog qhov sib tshuam concave, nrog rau cov undulations hauv thaj chaw nruab nrab thiab kev hloov pauv theem ntawm ntug. Qhov convexity ntawm qhov chaw sawv cev rau qee qib ntawm kev tsis sib xws hauv kev thauj cov khoom siv roj-theem, thiab qhov tshwm sim ntawm kev hloov pauv theem sib raug rau qhov sib piv C / Si qis. Qhov sib tshuam ntawm cov siv lead ua uas loj hlob los ntawm cov qauv 1 yog me ntsis convex, tsis muaj kev hloov pauv theem pom, thiab qhov tuab yog 65% ntawm cov siv lead ua tsis muaj PG. Feem ntau, cov txiaj ntsig kev loj hlob ntawm cov siv lead ua sib raug rau cov txiaj ntsig simulation, nrog rau qhov sib txawv ntawm qhov kub radial loj dua ntawm qhov sib tshuam ntawm cov siv lead ua ntawm cov qauv 1, kev loj hlob sai ntawm ntug raug suppressed, thiab tag nrho cov khoom siv ntws qeeb dua. Qhov sib txawv tag nrho yog sib xws nrog cov txiaj ntsig simulation lej.
Daim Duab 8 SiC cov siv lead ua los ntawm cov qauv 0 thiab cov qauv 1
Xaus lus
PG ua rau qhov kub ntawm thaj chaw raw khoom zoo dua qub thiab ua rau qhov kub thiab txias ntawm axial thiab radial zoo ib yam, ua rau cov khoom siv raw sublimation thiab siv tau tag nrho; qhov sib txawv ntawm qhov kub thiab txias sab saud thiab hauv qab nce ntxiv, thiab qhov radial gradient ntawm cov noob siv lead ua rau nce ntxiv, uas pab tswj qhov kev loj hlob ntawm convex interface. Hais txog kev hloov pauv ntawm cov pawg, kev siv PG txo qhov kev hloov pauv ntawm cov pawg tag nrho, qhov kev ntws ntawm cov khoom hauv chav loj hlob uas muaj PG hloov pauv tsawg dua nrog lub sijhawm, thiab tag nrho cov txheej txheem loj hlob ruaj khov dua. Tib lub sijhawm, PG kuj tseem tiv thaiv qhov tshwm sim ntawm kev hloov pauv ntawm ntug ntau dhau. Tsis tas li ntawd, PG kuj ua rau C/Si piv ntawm qhov chaw loj hlob, tshwj xeeb tshaj yog ntawm ntug pem hauv ntej ntawm cov noob siv lead ua interface, uas pab txo qhov tshwm sim ntawm kev hloov pauv theem thaum lub sijhawm loj hlob. Tib lub sijhawm, cov nyhuv rwb thaiv tsev thermal ntawm PG txo qhov tshwm sim ntawm recrystallization hauv sab saud ntawm cov khoom siv raw mus rau qee qhov. Rau kev loj hlob ntawm siv lead ua, PG ua rau qeeb qhov kev loj hlob ntawm siv lead ua, tab sis qhov kev loj hlob ntawm interface yog convex ntau dua. Yog li ntawd, PG yog ib txoj hauv kev zoo los txhim kho qhov chaw loj hlob ntawm SiC crystals thiab ua kom zoo dua qhov zoo ntawm crystal.
Lub sijhawm tshaj tawm: Lub Rau Hli-18-2024