Inqubo eyisisekelo yeI-SiCukukhula kwekristalu kuhlukaniswe kube yi-sublimation kanye nokubola kwezinto zokusetshenziswa ekushiseni okuphezulu, ukuthuthwa kwezinto zesigaba segesi ngaphansi kwesenzo se-gradient yokushisa, nokukhula kabusha kwe-recrystallization yezinto zesigaba segesi kukristalu lwembewu. Ngokusekelwe kulokhu, ingaphakathi le-crucible lihlukaniswe izingxenye ezintathu: indawo yempahla eluhlaza, igumbi lokukhula kanye nekristalu yembewu. Imodeli yokulingisa yezinombolo yadwetshwa ngokusekelwe kokumelana kwangempelaI-SiCimishini yokukhula yekristalu eyodwa (bheka Umfanekiso 1). Esibalweni: phansi kwe-crucibleikude no-90 mm ukusuka phansi kwe-heater eseceleni, izinga lokushisa eliphezulu le-crucible lingu-2100 ℃, ububanzi bezinhlayiya zokusetshenziswa yi-1000 μm, i-porosity ingu-0.6, ingcindezi yokukhula ingu-300 Pa, kanti isikhathi sokukhula singamahora angu-100. . Ubukhulu be-PG buyi-5 mm, ububanzi bulingana nobubanzi bangaphakathi be-crucible, futhi butholakala ku-30 mm ngaphezu kwempahla eluhlaza. Izinqubo ze-sublimation, carbonization, kanye ne-recrystallization zone yempahla eluhlaza zicatshangelwa esibalweni, futhi ukusabela phakathi kwe-PG nezinto zesigaba segesi akucatshangwa. Amapharamitha ezakhiwo ezibonakalayo ahlobene nokubala akhonjiswe kuThebula 1.
Umfanekiso 1 Imodeli yokubala yokulingisa. (a) Imodeli yenkundla eshisayo yokulingisa ukukhula kwekristalu; (b) Ukuhlukaniswa kwendawo yangaphakathi yezinkinga zomzimba ezixhunywayo nezihlobene
Ithebula 1 Amanye amapharamitha aphathekayo asetshenziswa esibalweni
Umfanekiso 2(a) ubonisa ukuthi izinga lokushisa lesakhiwo esiqukethe i-PG (eshiwo njengesakhiwo 1) liphakeme kunalelo lesakhiwo esingenayo i-PG (eshiwo njengesakhiwo esingu-0) ngaphansi kwe-PG, futhi siphansi kunesakhiwo esingu-0 ngaphezu kwe-PG. Isilinganiso sezinga lokushisa sisonke siyenyuka, futhi i-PG isebenza njenge-ejenti evikela ukushisa. Ngokusho kweMifanekiso 2(b) kanye no-2(c), izinga lokushisa le-axial kanye ne-radial lokushisa kwesakhiwo 1 endaweni yempahla eluhlaza mancane, ukusatshalaliswa kwezinga lokushisa kufana kakhulu, futhi i-sublimation yento iphelele kakhulu. Ngokungafani nendawo yempahla eluhlaza, Umfanekiso 2(c) ubonisa ukuthi izinga lokushisa elikhazimulayo ekristaluni lembewu yesakhiwo 1 likhulu, okungenzeka kubangelwe izilinganiso ezihlukene zezindlela zokudlulisa ukushisa ezihlukene, okusiza ikristalu ikhule ibe ne-convex interface. . Emfanekisweni 2(d), izinga lokushisa ezindaweni ezihlukene ku-crucible libonisa ukuthambekela okwandayo njengoba ukukhula kuqhubeka, kodwa umehluko wezinga lokushisa phakathi kwesakhiwo esingu-0 nesakhiwo 1 uyehla kancane kancane endaweni yempahla eluhlaza futhi kancane kancane anda egunjini lokukhula.
Umfanekiso 2 Ukusatshalaliswa kwezinga lokushisa nezinguquko ku-crucible. (a) Ukusabalalisa kwezinga lokushisa ngaphakathi kwe-crucible yesakhiwo esingu-0 (kwesokunxele) kanye nesakhiwo 1 (kwesokudla) ngo-0 h, iyunithi: ℃; (b) Ukusatshalaliswa kwezinga lokushisa emgqeni omaphakathi we-crucible yesakhiwo esingu-0 kanye nesakhiwo 1 ukusuka phansi kwempahla eluhlaza ukuya ekristalu yembewu ngo-0 h; (c) Ukusatshalaliswa kwezinga lokushisa ukusuka maphakathi kuye onqenqemeni lwekristalu endaweni yekristalu yembewu (A) nangaphezulu (B), maphakathi (C) nangaphansi (D) ngo-0 h, i-eksisi evundlile ingu-r Irediyasi yekristalu yembewu ka-A, kanye nerediyasi yendawo yempahla eluhlaza ye-B~D; (d) Ukushintsha kwezinga lokushisa enkabeni yengxenye engaphezulu (A), indawo yempahla eluhlaza (B) naphakathi (C) yegumbi lokukhula lesakhiwo esingu-0 kanye nesakhiwo 1 ku-0, 30, 60, kanye ne-100 h.
Umfanekiso wesi-3 ubonisa ukuthuthwa kwezinto ezibonakalayo ngezikhathi ezihlukene ku-crucible yesakhiwo 0 kanye nesakhiwo 1. Izinga lokugeleza kwezinto ezibonakalayo zesigaba segesi endaweni yempahla eluhlaza kanye negumbi lokukhula liyakhula ngokunyuka kwesikhundla, futhi ukuthuthwa kwezinto ezibonakalayo kuba buthaka njengoba ukukhula kuqhubeka. . Umfanekiso wesi-3 ubuye ubonise ukuthi ngaphansi kwezimo zokulingisa, impahla eluhlaza kuqala i-graphitize odongeni oluhlangothini lwe-crucible bese kuba phansi kwe-crucible. Ukwengeza, kukhona i-recrystallization ebusweni bempahla eluhlaza futhi kancane kancane ikhula njengoba ukukhula kuqhubeka. Izibalo 4(a) kanye no-4(b) zibonisa ukuthi izinga lokugeleza kwempahla ngaphakathi kwempahla eluhlaza liyehla njengoba ukukhula kuqhubeka, futhi izinga lokugeleza kwezinto ku-100 h licishe libe ngu-50% wesikhathi sokuqala; noma kunjalo, izinga lokugeleza likhulu kakhulu emaphethelweni ngenxa ye-graphitization yezinto ezingavuthiwe, futhi izinga lokugeleza emaphethelweni lingaphezu kwezikhathi ze-10 zezinga lokugeleza endaweni ephakathi nendawo ku-100 h; ngaphezu kwalokho, umphumela we-PG esakhiweni 1 wenza izinga lokugeleza kwezinto ezibonakalayo endaweni yempahla eluhlaza yesakhiwo esingu-1 libe phansi kunalelo lesakhiwo esingu-0. Emfanekisweni 4(c), ukugeleza kwezinto ezibonakalayo kokubili endaweni yempahla eluhlaza kanye Igumbi lokukhula liyancipha kancane kancane njengoba ukukhula kuqhubeka, futhi ukugeleza kwezinto ezibonakalayo endaweni eluhlaza kuyaqhubeka nokuncipha, okubangelwa ukuvulwa kwesiteshi sokugeleza komoya emaphethelweni e-crucible kanye nokuvinjelwa kwe-recrystallization phezulu; ekamelweni lokukhula, izinga lokugeleza kwezinto ezibonakalayo lesakhiwo esingu-0 lehla ngokushesha emahoreni angama-30 okuqala ukuya ku-16%, futhi lehla kuphela ngo-3% esikhathini esilandelayo, kuyilapho isakhiwo 1 sihlala sizinzile phakathi nenqubo yokukhula. Ngakho-ke, i-PG isiza ukuzinzisa izinga lokugeleza kwezinto ezibonakalayo egumbini lokukhula. Umfanekiso 4(d) uqhathanisa izinga lokugeleza kokubalulekile ngaphambili kokukhula kwekristalu. Esikhathini sokuqala kanye namahora angu-100, ukuthutha kwezinto ezibonakalayo endaweni yokukhula yesakhiwo esingu-0 kunamandla kunaleso esakhiweni 1, kodwa kuhlale kunesilinganiso sokugeleza okuphezulu endaweni emaphethelweni esakhiwo esingu-0, okuholela ekukhuleni ngokweqile emaphethelweni. . Ukuba khona kwe-PG esakhiweni 1 kusicindezela ngempumelelo lesi simo.
Umfanekiso 3 Ukugeleza kwezinto ku-crucible. Imigqa (kwesobunxele) kanye namavekhtha esivinini (kwesokudla) sokuthuthwa kwegesi esakhiweni esingu-0 no-1 ngezikhathi ezihlukene, iyunithi yevekhtha yesivinini: m/s
Umfanekiso 4 Izinguquko kuzinga lokugeleza kwezinto. (a) Izinguquko ekusatshalalisweni kwesilinganiso sokugeleza kwempahla phakathi kwempahla eluhlaza yesakhiwo 0 ku-0, 30, 60, kanye no-100 h, r iyiradiyasi yendawo yempahla eluhlaza; (b) Izinguquko ekusatshalalisweni kwesilinganiso sokugeleza kwempahla phakathi kwempahla eluhlaza yesakhiwo 1 ku-0, 30, 60, kanye namahora angu-100, r iyiradiyasi yendawo yempahla eluhlaza; (c) Izinguquko kuzinga lokugeleza kwempahla ngaphakathi kwegumbi lokukhula (A, B) nangaphakathi kwempahla eluhlaza (C, D) yezakhiwo 0 no-1 ngokuhamba kwesikhathi; (d) Ukusatshalaliswa kwezinga lokugeleza kokubalulekile eduze kwendawo yekristalu yezinhlamvu yezakhiwo 0 no-1 ku-0 no-100 h, r iyiradiyasi yekristalu lembewu
I-C/Si ithinta ukuzinza kwekristalu nokuminyana kokukhubazeka kokukhula kwekristalu ye-SiC. Umfanekiso 5(a) uqhathanisa ukusabalalisa kwesilinganiso se-C/Si kwezakhiwo ezimbili ngesikhathi sokuqala. Isilinganiso se-C/Si siyehla kancane kancane sisuka phansi siye phezulu kwe-crucible, futhi isilinganiso se-C/Si sesakhiwo esingu-1 sihlala siphakeme kunaleso sesakhiwo esingu-0 ezindaweni ezihlukene. Izibalo 5(b) kanye no-5(c) zibonisa ukuthi isilinganiso se-C/Si sikhula kancane kancane ngokukhula, okuhlobene nokwenyuka kwezinga lokushisa langaphakathi esigabeni sakamuva sokukhula, ukuthuthukiswa kwe-graphitization yezinto ezingavuthiwe, kanye nokusabela kwe-Si. izingxenye zesigaba segesi nge-graphite crucible. Emfanekisweni 5(d), izilinganiso ze-C/Si zesakhiwo esingu-0 nesakhiwo esingu-1 zihluke kakhulu ngaphansi kwe-PG (0, 25 mm), kodwa zihluke kancane ngaphezu kwe-PG (50 mm), futhi umehluko uyakhula kancane kancane njengoba usondela ku-crystal. . Ngokuvamile, isilinganiso se-C/Si sesakhiwo esingu-1 siphezulu, esiza ukuzinzisa ifomu lekristalu nokunciphisa amathuba okushintsha kwesigaba.
Umfanekiso 5 Ukusabalalisa kanye nezinguquko zesilinganiso se-C/Si. (a) Ukusatshalaliswa kwesilinganiso se-C/Si kumakhilogremu esakhiwo esingu-0 (kwesokunxele) nesakhiwo 1 (kwesokudla) ngo-0 h; (b) Isilinganiso se-C/Si emabangeni ahlukene ukusuka emgqeni omaphakathi we-crucible wesakhiwo esingu-0 ngezikhathi ezihlukene (0, 30, 60, 100 h); (c) Isilinganiso se-C/Si emabangeni ahlukene ukusuka emgqeni omaphakathi we-crucible wesakhiwo 1 ngezikhathi ezahlukene (0, 30, 60, 100 h); (d) Ukuqhathaniswa kwesilinganiso se-C/Si emabangeni ahlukene (0, 25, 50, 75, 100 mm) kusukela emgqeni ophakathi we-crucible yesakhiwo esingu-0 (umugqa oqinile) kanye nesakhiwo 1 (umugqa odayishiwe) ngezikhathi ezahlukene (0, 30, 60, 100 h).
Umfanekiso wesi-6 ubonisa izinguquko kububanzi bezinhlayiyana kanye ne-porosity yezifunda zezinto ezingavuthiwe zezakhiwo ezimbili. Isibalo sibonisa ukuthi ububanzi bempahla eluhlaza buyancipha futhi i-porosity iyanda eduze kodonga oluyi-crucible, futhi i-porosity enqenqemeni iyaqhubeka nokukhula futhi ububanzi bezinhlayiyana buqhubeka nokuncipha njengoba ukukhula kuqhubeka. I-porosity ephezulu yomkhawulo ingaba ngu-0.99 ku-100 h, futhi ubuncane bezinhlayiyana ububanzi bungaba ngu-300 μm. Ububanzi bezinhlayiyana buyakhula futhi i-porosity iyancipha endaweni engaphezulu yezinto ezingavuthiwe, ezihambisana ne-recrystallization. Ubukhulu bendawo ye-recrystallization buyanda njengoba ukukhula kuqhubeka, futhi ubukhulu bezinhlayiyana kanye ne-porosity iqhubeka nokushintsha. Ubukhulu bezinhlayiyana ububanzi bufinyelela ngaphezu kwe-1500 μm, futhi ubuncane be-porosity bungu-0.13. Ngaphezu kwalokho, njengoba i-PG inyusa izinga lokushisa lendawo eluhlaza kanye ne-gas supersaturation incane, ukushuba kwe-recrystallization yengxenye engenhla yezinto ezingavuthiwe zesakhiwo 1 kuncane, okuthuthukisa izinga lokusebenzisa impahla eluhlaza.
Umfanekiso 6 Izinguquko kububanzi bezinhlayiyana (kwesokunxele) kanye ne-porosity (kwesokudla) yendawo eluhlaza yesakhiwo esingu-0 nesakhiwo 1 ngezikhathi ezihlukene, iyunithi yobubanzi bezinhlayiyana: μm
Umfanekiso wesi-7 ubonisa ukuthi ukwakheka okungu-0 ku-warps ekuqaleni kokukhula, okungase kuhlotshaniswe nezinga lokugeleza kwezinto ezibonakalayo okubangelwa i-graphitization yonqenqema lwempahla eluhlaza. Izinga le-warping liba buthakathaka ngesikhathi senqubo yokukhula elandelayo, ehambisana noshintsho lwezinga lokugeleza kwezinto ngaphambi kokukhula kwekristalu kwesakhiwo 0 kuMfanekiso 4 (d). Kusakhiwo 1, ngenxa yomphumela we-PG, isixhumi esibonakalayo sekristalu asibonisi ukungqubuzana. Ngaphezu kwalokho, i-PG iphinde yenza izinga lokukhula kwesakhiwo esingu-1 libe phansi kakhulu kunesakhiwo esingu-0. Ugqinsi olumaphakathi lwekristalu yesakhiwo esingu-1 ngemva kwamahora angu-100 luyi-68% kuphela lwalolo lwesakhiwo esingu-0.
Umfanekiso 7 Izinguquko zesixhumi esibonakalayo sesakhiwo 0 kanye nesakhiwo samakristalu angu-1 ku-30, 60, kanye ne-100 h.
Ukukhula kwe-Crystal kwenziwa ngaphansi kwezimo zenqubo yokulingisa izinombolo. Amakristalu akhuliswe ngesakhiwo 0 kanye nesakhiwo 1 aboniswa kuMfanekiso 8(a) kanye noMfanekiso 8(b), ngokulandelana. Ikristalu yesakhiwo esingu-0 ikhombisa ukusebenzelana kwe-concave, nokuguquguquka endaweni emaphakathi kanye noshintsho lwesigaba emaphethelweni. I-surface convexity imele izinga elithile le-inhomogeneity ekuthuthweni kwezinto ze-gas-phase, futhi ukuvela kokuguqulwa kwesigaba kuhambisana nesilinganiso esiphansi se-C / Si. I-interface ye-crystal ekhuliswe isakhiwo 1 i-convex kancane, akukho ukuguqulwa kwesigaba esitholakalayo, futhi ubukhulu bungama-65% wekristalu ngaphandle kwe-PG. Ngokuvamile, imiphumela yokukhula kwekristalu ihambisana nemiphumela yokulingisa, enomehluko omkhulu wokushisa we-radial ku-interface ye-crystal yesakhiwo 1, ukukhula okusheshayo onqenqemeni kuyacindezelwa, futhi izinga lokugeleza kwezinto ezibonakalayo lihamba kancane. Umkhuba usuwonke uhambisana nemiphumela yokulingisa yezinombolo.
Umfanekiso 8 amakristalu e-SiC akhule ngaphansi kwesakhiwo 0 kanye nesakhiwo 1
Isiphetho
I-PG isiza ekuthuthukisweni kwezinga lokushisa eliphelele lendawo yempahla eluhlaza kanye nokwenza ngcono ukufana kwezinga lokushisa kwe-axial ne-radial, ukukhuthaza ukuncishiswa okuphelele nokusetshenziswa kwempahla eluhlaza; umehluko wezinga lokushisa eliphezulu naphansi uyakhula, futhi i-radial gradient yendawo yekristalu yembewu iyanda, okusiza ukugcina ukukhula kwe-convex interface. Mayelana nokudluliswa kwenqwaba, ukwethulwa kwe-PG kunciphisa izinga lokudluliswa kwenqwaba, izinga lokugeleza kwezinto ezibonakalayo egumbini lokukhula eliqukethe i-PG lishintsha kancane ngokuhamba kwesikhathi, futhi yonke inqubo yokukhula izinzile. Ngasikhathi sinye, i-PG iphinda ivimbele ngempumelelo ukwenzeka kokudluliswa kwenqwaba yonqenqema. Ngaphezu kwalokho, i-PG iphinde ikhulise isilinganiso se-C/Si semvelo yokukhula, ikakhulukazi emaphethelweni angaphambili e-seed crystal interface, okusiza ukunciphisa ukuvela koshintsho lwesigaba phakathi nenqubo yokukhula. Ngasikhathi sinye, umphumela wokushisa oshisayo we-PG unciphisa ukwenzeka kokuphinda kukhanye engxenyeni engenhla yezinto ezingavuthiwe ngokwezinga elithile. Ngokukhula kwekristalu, i-PG yehlisa izinga lokukhula kwekristalu, kodwa isixhumi esibonakalayo sokukhula siqonde kakhulu. Ngakho-ke, i-PG iyindlela esebenzayo yokuthuthukisa indawo yokukhula yamakristalu e-SiC nokwandisa ikhwalithi yekristalu.
Isikhathi sokuthumela: Jun-18-2024