Njengoba kuboniswe kumfanekiso wesi-3, kunezindlela ezintathu eziyinhloko ezihloswe ukuhlinzeka ngekristalu eyodwa ye-SiC enekhwalithi ephezulu nokusebenza kahle: i-liquid phase epitaxy (LPE), ukuthuthwa komhwamuko obonakalayo (PVT), kanye ne-high-temperature chemical vapor deposition (HTCVD). I-PVT iyinqubo esungulwe kahle yokukhiqiza ikristalu eyodwa ye-SiC, esetshenziswa kakhulu kubakhiqizi abakhulu be-wafer.
Kodwa-ke, zonke lezi zinqubo ezintathu zithuthuka ngokushesha futhi zisungula izinto ezintsha. Akukenzeki okwamanje ukuvimbela ukuthi iyiphi inqubo ezokwamukelwa kabanzi esikhathini esizayo. Ikakhulukazi, i-crystal single yekhwalithi ephezulu ye-SiC ekhiqizwa ukukhula kwesixazululo ngenani elikhulu kuye kwabikwa eminyakeni yamuva nje, ukukhula kwenqwaba ye-SiC esigabeni soketshezi kudinga izinga lokushisa eliphansi kunalelo lenqubo ye-sublimation noma yokubeka, futhi ikhombisa ubuhle ekukhiqizeni i-P. -hlobo lwe-SiC substrates (Ithebula 3) [33, 34].
Umfanekiso wesi-3: Uhlelo lwamasu amathathu abusayo okukhula kwekristalu elilodwa le-SiC: (a) i-epitaxy yesigaba soketshezi; (b) ukuthuthwa komhwamuko obonakalayo; (c) izinga lokushisa eliphezulu lomhwamuko wamakhemikhali
Ithebula 3: Ukuqhathaniswa kwe-LPE, i-PVT ne-HTCVD yokukhula kwamakristalu e-SiC eyodwa [33, 34]
Ukukhula kwesixazululo ubuchwepheshe obujwayelekile bokulungiselela ama-semiconductors ahlanganisiwe [36]. Kusukela ngawo-1960, abacwaningi baye bazama ukuthuthukisa i-crystal esixazululo [37]. Uma ubuchwepheshe buthuthukisiwe, i-supersaturation yendawo yokukhula ingalawulwa kahle, okwenza indlela yesixazululo ibe ubuchwepheshe obuthembisayo bokuthola ingots ye-crystal eyodwa yekhwalithi ephezulu.
Ukuze uthole isixazululo sokukhula kwekristalu eyodwa ye-SiC, umthombo we-Si usuka ku-Si encibilika kakhulu kuyilapho i-graphite crucible isebenza ngezinjongo ezimbili: i-heater kanye nomthombo we-C solute. Amakristalu e-SiC eyodwa kungenzeka ukuthi akhule ngaphansi kwesilinganiso esifanele se-stoichiometric lapho isilinganiso se-C ne-Si siseduze ne-1, okubonisa ukuminyana okungaphansi [28]. Kodwa-ke, ekucindezelweni komkhathi, i-SiC ayibonisi indawo yokuncibilika futhi ibola ngokuqondile ngezinga lokushisa elihwamukayo elingaphezu kuka-2,000 °C. I-SiC iyancibilika, ngokusho kokulindela okucatshangwayo, ingakhiwa kuphela ngaphansi kobunzima obubonakalayo kusukela kumdwebo wesigaba se-Si-C kanambambili (Fig. 4) ukuthi nge-gradient yokushisa kanye nesistimu yesisombululo. Ukuphakama kwe-C ku-Si melt kuyehluka ukusuka ku-1at.% kuye ku-13at.%. I-supersaturation engu-C eshayelayo, ishesha izinga lokukhula, kuyilapho amandla aphansi ka-C okukhula kuwu-C supersaturation ebusa ingcindezi engu-109 Pa kanye nezinga lokushisa elingaphezu kuka-3,200 °C. Ingakwazi ukugcwalisa i-supersaturation ikhiqize indawo ebushelelezi [22, 36-38] .izinga lokushisa eliphakathi kuka-1,400 no-2,800 °C, ukuncibilika kwe-C ku-Si melt kuyahlukahluka kusuka ku-1at.% kuya ku-13at. Amandla ashukumisayo okukhula yi-C supersaturation elawulwa yizinga lokushisa kanye nesistimu yesisombululo. Ukuphakama kwe-C supersaturation, kuyashesha izinga lokukhula, kuyilapho i-supersaturation ephansi ye-C ikhiqiza indawo ebushelelezi [22, 36-38].
Umfanekiso 4: Umdwebo wesigaba kanambambili we-Si-C [40]
Izakhi zensimbi ezishintshayo ze-doping noma izakhi zomhlaba ezingavamile awehlisi kuphela ngempumelelo izinga lokushisa lokukhula kodwa kubonakala kuwukuphela kwendlela yokuthuthukisa kakhulu ukunyibilika kwekhabhoni ku-Si melt. Ukwengezwa kwezinsimbi zeqembu lenguquko, njengeTi [8, 14-16, 19, 40-52], Cr [29, 30, 43, 50, 53-75], Co [63, 76], Fe [77- 80], njll. noma izinsimbi zomhlaba ezingavamile, njenge-Ce [81], Y [82], Sc, njll. ukuya ku-Si melt ivumela ikhabhoni ukunyibilika ukuze kudlule u-50at.% esimweni esiseduze nokulingana kwe-thermodynamic. Ngaphezu kwalokho, inqubo ye-LPE ivuna i-P-type doping ye-SiC, engafinyelelwa ngokuhlanganisa i-Al ku-doping.
i-solvent [50, 53, 56, 59, 64, 71-73, 82, 83]. Kodwa-ke, ukufakwa kwe-Al kuholela ekwandeni kokuphikiswa kwe-P-type SiC crystals eyodwa [49, 56].Ngaphandle kokukhula kohlobo lwe-N ngaphansi kwe-nitrogen doping,
ukukhula kwesixazululo ngokuvamile kuqhubeka endaweni yegesi engasebenzi. Nakuba i-helium (He) ibiza kakhulu kune-argon, ithandwa izazi eziningi ngenxa ye-viscosity yayo ephansi kanye nokushisa okuphezulu kwe-thermal conductivity (izikhathi ezingu-8 ze-argon) [85]. Izinga lokufuduka kanye nokuqukethwe kwe-Cr ku-4H-SiC kuyafana ngaphansi kwe-He and Ar atmosphere, kufakazelwa ukuthi ukukhula ngaphansi kwe-Heresults ngenani lokukhula eliphakeme kunokukhula ngaphansi kwe-Ar ngenxa yokuhlakazeka okukhulu kokushisa komnikazi wembewu [68]. Uvimbela ukwakheka kwe-voids ngaphakathi kwekristalu elikhulile kanye ne-nucleation ezenzakalelayo esixazululweni, khona-ke, i-morphology yendawo ebushelelezi ingatholakala [86].
Leli phepha lethule ukuthuthukiswa, izinhlelo zokusebenza, kanye nezakhiwo zamadivayisi we-SiC, nezindlela ezintathu eziyinhloko zokukhulisa ikristalu eyodwa ye-SiC. Ezigabeni ezilandelayo, izindlela zamanje zokukhula kwesixazululo kanye nemingcele esemqoka ehambisanayo kubuyekeziwe. Ekugcineni, kwahlongozwa umbono owawudingida izinselele nemisebenzi yesikhathi esizayo mayelana nokukhula kwenqwaba yamakristalu e-SiC eyodwa ngendlela yesixazululo.
Isikhathi sokuthumela: Jul-01-2024