Indlela ye-PVT, egama layo eliphelele yi-Physical Vapor Transportation, iyindlela evamile yokukhulisa i-silicon carbide (I-SiC)amakristalu angaphansi kokushisa okuphezulu kanye nokucindezela okuphezulu. Isimiso sawo esiyisisekelo ukushisa i-silicon carbide powder ibe yi-sublimation ekushiseni okungaphezu kuka-2300℃ kanye nasendaweni enokucindezela okuphansi eduze kwe-vacuum, kwakha igesi yokusabela equkethe izingxenye zegesi ezifana ne-Si, i-Si2C, ne-SiC2. Ngenxa yokucindezela okuhlukile kwesigaba segesi kwezingxenye ze-Si ne-C ezakhiwe yi-sublimation reaction yesigaba esiqinile, isilinganiso se-Si/C stoichiometric siyahlukahluka ngokusatshalaliswa kwensimu yokushisa. Ngakho-ke, kubalulekile ukulawula ukusatshalaliswa kanye nokuthuthwa kwezingxenye zesigaba segesi ukuqinisekisa ukuthi zifinyelela ezikhundleni ezithile ze-crystallization ekamelweni lokukhula.
Ukuze kuvinjelwe ukwakheka kwe-crystallization yesigaba segesi okungahlelekile ekwakheni i-polycrystalline silicon carbide, amakristalu embewu ye-silicon carbide abekwa phezulu kwegumbi lokukhula. Ngaphansi kokuqhutshwa kwe-gas-phase supersaturation, izingxenye zesigaba segesi zizohlala phezu kwekristalu yembewu ukuze zakhe amakristalu angawodwa e-silicon carbide. Inqubo yonke yokusabela yenzeka ekamelweni lokukhula elivaliwe, lapho wonke amapharamitha esistimu yokusabela ehlanganiswa khona. Noma yikuphi ukuguquguquka kwezimo zokukhula kuzothinta ukuzinza kokukhula kwekristalu elilodwa.
Ngaphezu kwalokho, izakhiwo ezahlukene ezisondelene zamakristalu angawodwa e-silicon carbide ngokwendlela aqondisa ngayo ikristalu ziholela ekuxhumaneni okuhlukahlukene kwe-athomu kanye nezindlela zokubopha, ngaleyo ndlela zakha izinhlobo ezingaphezu kuka-200 zamakristalu ama-isomer e-silicon carbide. Isithiyo sokuguqulwa kwamandla phakathi kwezinhlobo ezahlukene zamakristalu siphansi kakhulu, ngakho-ke ukuguqulwa kwefomu lamakristalu kungenzeka kakhulu ohlelweni lokukhula kwekristalu elilodwa le-PVT, okuholela ezinhlotsheni zamakristalu angahlelekile kanye neziphambeko ezahlukahlukene ze-crystallization. Ngakho-ke, kuyadingeka ukusebenzisa imishini yokuhlola ezinikele ukuthola ifomu lamakristalu kanye neziphambeko ezahlukahlukene ze-ingot yamakristalu.
Inqubo yokulungiselela i-silicon carbide inezidingo eziphakeme kakhulu, ikakhulukazi ezibonakala kulezi zici ezilandelayo:
- Kunokungcola okuningi kwemvelo enqubweni yokwenziwa kwempuphu ye-silicon carbide, okwenza kube nzima ukuthola impuphu ehlanzekile kakhulu. Ukusabela okungaphelele phakathi kwempuphu ye-silicon nempuphu ye-carbon njengomthombo wokusabela kungabangela ukungalingani kwesilinganiso se-Si/C. Ifomu lekristalu kanye nosayizi wezinhlayiya zempuphu ye-silicon carbide ngemva kokwenziwa kunzima ukulawula.
- Ngaphansi kwezimo zokushisa okuphezulu okungaphezu kuka-2300℃ kanye ne-vacuum eseduze, i-silicon carbide idlula enqubweni yokuguqulwa kwe-"solid-gas-solid" kanye nenqubo yokuphinda isetshenziswe ekamelweni le-graphite elivaliwe. Le nqubo inomjikelezo omude wokukhula, kunzima ukuyilawula, futhi ithambekele ekuphazamisekeni okufana nama-microtubules kanye nokuqunjelwa.
- I-silicon carbide ihlanganisa izinhlobo zekristalu ezingaphezu kuka-200 ezahlukene, kodwa ukukhiqizwa kuvame ukudinga uhlobo lwekristalu olulodwa kuphela. Ngesikhathi senqubo yokukhula, ukuguqulwa kwefomu lekristalu kuthambekele ekuveleni, okuholela emaphutheni okufakwa kwezinhlobo eziningi. Ngesikhathi senqubo yokulungiselela, kunzima ukulawula ngokuzinzile uhlobo olulodwa lwekristalu oluthile, futhi isithiyo sokuguqulwa kwamandla phakathi kwezinhlobo ezahlukene zekristalu siphansi kakhulu, okwandisa ubunzima bokulawula. Ukulawulwa kwamapharamitha kanye nocwaningo oluhlobene phakathi nalesi sikhathi kudinga izindleko ezinkulu ze-R&D, okungenye yezizathu zezindleko eziphezulu ze-silicon carbide ehambisanayo.
Isikhathi sokuthunyelwe: Julayi-03-2025