Isendlalelo se-epitaxial yifilimu ethize ecwebezelayo enekristalu elilodwa ekhuliswe ku-substrate ye-wafer ngenqubo ye-epitaxial; i-substrate wafer kanye nefilimu ye-epitaxial kubizwa ngokuthi i-epitaxial wafer. Phakathi kwalokhu, ukukhulisa isendlalelo se-epitaxial se-silicon carbide ku-substrate ye-silicon carbide eqhubayo kukhiqiza i-epitaxial wafer ye-silicon carbide epitaxial efanayo, engenziwa futhi ibe amadivayisi kagesi njenge-Schottky diodes, i-MOSFET, kanye ne-IGBTs. Uhlobo lwe-substrate olusetshenziswa kakhulu yi-substrate ye-4H-SiC.
Njengoba cishe wonke amadivayisi enziwa ngezendlalelo ze-epitaxial, ikhwalithi yesendlalelo se-epitaxial inomthelela omkhulu ekusebenzeni kwedivayisi. Kodwa-ke, ikhwalithi yesendlalelo se-epitaxial ithonywa ukucutshungulwa kwekristalu kanye ne-substrate, okukubeka esimweni esibucayi embonini futhi kudlala indima ebalulekile ekuthuthukisweni kwayo.
Izindlela eziyinhloko zokulungiselela izendlalelo ze-epitaxial ze-silicon carbide zifaka: ukufakwa komoya; i-epitaxy yesigaba soketshezi (i-LPE); i-epitaxy ye-molecular beam (MBE); kanye ne-chemical vapor deposition (i-CVD). Phakathi kwalezi, ukufakwa komoya we-chemical vapor (i-CVD) kuyindlela esetshenziswa kakhulu ye-4H-SiC homogeneous epitaxy. I-4H-SiC CVD epitaxy ivame ukusebenzisa imishini ye-CVD, eqinisekisa ukuqhubeka kwesakhiwo sekristalu se-4H-SiC ngaphansi kwamazinga okushisa aphezulu okukhula.
Emishinini ye-CVD, i-substrate ayikwazi ukubekwa ngqo phezu kwensimbi noma ibekwe nje esisekelweni sokufakwa kwe-epitaxial, njengoba lokhu kuhilela izici ezahlukahlukene ezithonya njengesiqondiso sokugeleza kwegesi (okuvundlile, okuqondile), izinga lokushisa, ingcindezi, ukuqina, kanye nokungcola okuvela ezinhlayiyeni ezichithekayo. Ngakho-ke, kudingeka isisekelo sokusekela; i-substrate ibekwa kuthreyi, bese ukufakwa kwe-epitaxial kwenziwa ku-substrate kusetshenziswa ubuchwepheshe be-CVD. Lesi sisekelo sokusekela siyisisekelo se-graphite esimbozwe yi-SiC.
Njengengxenye eyinhloko, i-graphite substrate inamandla aphezulu athile kanye ne-modulus ethile, kanye nokushaqeka okuhle kokushisa kanye nokumelana nokugqwala. Kodwa-ke, ngesikhathi sokukhiqizwa, i-graphite ibhekene nokugqwala kanye nokuchitheka kwempuphu ngenxa yamagesi agqwalayo kanye nama-organometallic compounds asele, okunciphisa kakhulu impilo yenkonzo ye-substrate. Ngesikhathi esifanayo, i-graphite powder eshed ingangcolisa ama-chips. Ekukhiqizweni kwama-wafer epitaxial epitaxial esilicon carbide, kuye kwaba nzima kakhulu ukuhlangabezana nezidingo ezihlala ziqinile zezinto ze-graphite, okunciphisa kakhulu intuthuko yazo kanye nokusetshenziswa kwazo okusebenzayo. Ngenxa yalokho,ubuchwepheshe bokumbozasekuvele njengesixazululo.
Izinzuzo ze-SiC Coatings embonini ye-Semiconductor
Izakhiwo zomzimba nezamakhemikhali zezembozo kumele zihlangabezane nezidingo eziqinile zokumelana nokushisa okuphezulu nokugqwala, njengoba lokhu kuthinta ngqo isivuno somkhiqizo kanye nesikhathi sokuphila. Izinto ze-SiC zinamandla aphezulu, ubulukhuni obuphezulu, i-coefficient ephansi yokwanda kokushisa, kanye nokuqhuba kahle kokushisa, okwenza kube yinto ebalulekile yokwakha kanye ne-semiconductor yokushisa okuphezulu. Uma isetshenziswa kuma-substrate e-graphite, izinzuzo zayo zifaka:
1) I-SiC imelana nokugqwala futhi ingahlanganisa ngokuphelele i-graphite substrate. Ubuningi bayo obuphezulu buvimbela umonakalo ovela kumagesi agqwalayo.
2) I-SiC inokushisa okuphezulu kanye namandla aqinile okubopha ne-graphite substrate, okuqinisekisa ukuthi ukugqoka kuhlala kuphelele ngisho nangemva kwemijikelezo ephindaphindwayo yokushisa okuphansi kakhulu.
3) I-SiC inokuqina okuhle kwamakhemikhali, ivimbela ukwehluleka kokumboza ezindaweni ezishisa kakhulu nezigqwalayo.
Ngaphezu kwalokho, izitofu ze-epitaxial ezenziwe ngezinto ezahlukene zidinga amathreyi e-graphite anezincazelo ezithile zokusebenza. I-coefficient yokwandisa ukushisa kwezinto ze-graphite kumele ihambisane nokushisa kokukhula kwesithando se-epitaxial. Isibonelo, njengoba izinga lokushisa lokukhula kwe-silicon carbide epitaxy liphezulu, amathreyi anezinga eliphezulu lokufanisa i-coefficient yokukhulisa ukushisa ayadingeka. I-coefficient yokukhulisa ukushisa ye-SiC ihluke kakhulu kweye-graphite, okwenza kube yinto ekhethwayo yokumboza ubuso be-substrates ze-graphite.
I-SiC ikhona ngezindlela eziningi zekristalu, kanti ezivame kakhulu njengamanje ziyizinhlobo ze-3C, 4H, kanye ne-6H, ngayinye ikhonza izinhlelo zokusebenza ezahlukene. Isibonelo, i-4H-SiC isetshenziselwa ukukhiqiza amadivayisi anamandla aphezulu; i-6H-SiC iyona ezinzile kakhulu futhi isetshenziselwa ukukhiqiza amadivayisi e-optoelectronic; kanti i-3C-SiC, ngenxa yokufana kwayo nesakhiwo ne-GaN, isetshenziselwa ukukhiqiza izendlalelo ze-epitaxial ze-GaN zokukhiqiza amadivayisi e-SiC-GaN RF. I-3C-SiC ibizwa nangokuthi i-β-SiC. Ukusetshenziswa okuyinhloko kwe-β-SiC njengefilimu encane kanye nezinto zokumboza; ngenxa yalokho, i-β-SiC okwamanje iyinto eyinhloko esetshenziselwa ukumboza.
Njengento evamile esetshenziswa ekukhiqizweni kwe-semiconductor, izembozo ze-SiC zisetshenziswa kakhulu ezinqubweni ezifana nokulungiswa kwe-substrate, i-epitaxy, i-oxidation kanye ne-diffusion, i-etching, kanye nokufakelwa kwe-ion. Izakhiwo zomzimba nezamakhemikhali zezembozo kumele zihlangabezane nezidingo eziqinile zokumelana nokushisa okuphezulu kanye nokumelana nokugqwala, njengoba lokhu kuthinta ngqo isivuno somkhiqizo kanye nesikhathi sokuphila. Ngenxa yalokho, ukulungiswa kwezembozo ze-SiC kubalulekile.
Inqubo Yokulungiselela Izembozo Ze-Silicon Carbide
Njengamanje, izindlela eziyinhloko zokulungiselela izembozo ze-SiC zifaka phakathi indlela ye-sol-gel, indlela yokushumeka, isembozo sebhulashi, ukufutha nge-plasma, ukusabela komusi wamakhemikhali (i-CVR), kanye ne-chemical vapor deposition (i-CVD).
Indlela Yokushumeka
Le ndlela iwuhlobo lokushisa okuphezulu kwe-solid-state sintering. Ngokuyinhloko isebenzisa ingxube ye-silicon (Si) powder kanye ne-carbon (C) powder njenge-embedding powder. I-graphite substrate ifakwa ngaphakathi kwe-embedding powder bese ishiswa emazingeni okushisa aphezulu emoyeni wegesi ongenawo umoya, ekugcineni yakha i-SiC coating ebusweni be-graphite substrate. Le ndlela inenqubo elula kanye nokunamathela okuhle phakathi kwe-coating kanye ne-substrate; noma kunjalo, i-coating ibonisa ukufana okuncane eceleni kobukhulu futhi ithambekele ekwakheni ama-pores amaningi, okuholela ekumelaneni okubi kwe-oxidation.
Indlela Yokumboza Ibhulashi
Indlela yokumboza ngebhulashi ihilela kakhulu ukufaka izinto zokusetshenziswa eziwuketshezi ebusweni be-substrate ye-graphite, kulandelwe ukuphola kwezinto ekushiseni okuthile ukuze kwakheke i-coating. Le ndlela ilula futhi ingabizi kakhulu; noma kunjalo, i-coating ephumayo ibonisa ukunamathela okubuthakathaka kwi-substrate, ukufana okubi, futhi incane kakhulu ngokumelana nokushiswa okuphansi, okudinga izindlela ezengeziwe.
Indlela Yokufafaza Nge-Plasma
Indlela yokufafaza nge-plasma ihilela ukusebenzisa isibhamu se-plasma ukufutha izinto zokusetshenziswa ezincibilikisiwe noma ezincibilikisiwe kancane phezu kwe-graphite substrate, bese iqina bese ibophana ukuze yakhe i-coating. Le ndlela ilula ukuyisebenzisa futhi ingakhiqiza i-silicon carbide coating exinene; noma kunjalo, i-coating ephumayo ivame ukuba mncane kakhulu, okuholela ekumelaneni ne-oxidation okungekuhle. Ngakho-ke, ivame ukusetshenziswa ekulungiseleleni i-SiC composite coating ukuthuthukisa ikhwalithi ye-coating.
Indlela ye-Gel-Sol
Indlela ye-gel-sol ihilela kakhulu ukulungiselela isisombululo se-sol esifanayo, esibonakalayo ukuze simboze ubuso be-substrate. Ngemva kokomiswa kube yi-gel, izinto ziyashiswa ukuze kwakhiwe isembozo. Le ndlela ilula ukuyisebenzisa futhi ishibhile; noma kunjalo, isembozo esivelayo sihlushwa izinkinga ezifana nokumelana nokushaqeka okuphansi kokushisa kanye nokuthambekela kokuqhekeka, okunciphisa ukusetshenziswa kwazo kabanzi.
Indlela Yokusabela Komphunga Wamakhemikhali (i-CVR)
I-CVR isebenzisa kakhulu izimpushana ze-Si kanye ne-SiO₂ ukukhiqiza umhwamuko we-SiO₂ emazingeni okushisa aphezulu, okubangela uchungechunge lwezimpendulo zamakhemikhali ebusweni be-substrate ye-Si ukuze kwakhiwe i-SiC coating. I-SiC coating ekhiqizwa yile ndlela ibopha ngokuqinile kwi-substrate; noma kunjalo, izinga lokushisa lokusabela liphezulu, futhi izindleko nazo ziphakeme kakhulu.
Ukususwa Komusi Wekhemikhali (i-CVD)
I-CVD njengamanje ubuchwepheshe obuyinhloko bokulungiselela izembozo ze-SiC ezindaweni ze-substrate. Inqubo eyinhloko ihilela uchungechunge lwezimpendulo ze-physicochemical phakathi kwe-reactants yegesi kanye nobuso be-substrate, ekugcineni okuholela ekubekweni kwe-SiC coating. Izembozo ze-SiC ezikhiqizwa ubuchwepheshe be-CVD zibopha ngokuqinile ebusweni be-substrate futhi zingathuthukisa ngempumelelo ukumelana kwe-oxidation kanye nokumelana kwe-ablation kwezinto ze-substrate; noma kunjalo, le ndlela idinga isikhathi eside sokufakwa, futhi amagesi okusabela aqukethe izingxenye ezithile ezinobuthi.
Amathrendi ku-SiC Coatings
Izembozo ze-SiC zisetshenziswa kakhulu njengezinto ezisetshenziswayo ekukhiqizweni kwe-semiconductor, ngezilinganiso zokusebenza ezibalulekile ezifaka phakathi ukufana kwezembozo, i-coefficient of thermal expansion, kanye ne-thermal conductivity. Nakuba kunesidingo esikhulu sasekhaya sezembozo ze-SiC eShayina, ubuchwepheshe busalokhu bungavuthiwe. Kwamanye amazwe, inkampani eyodwa kuphela yase-US esebenza kulo mkhakha, futhi imikhiqizo yayo ibiza kakhulu.
Izikebhe zekristaluyizinto ezisetshenziswayo ezisetshenziswa ekukhiqizweni kwe-epitaxial ezingathatha indawo ye-graphite eboshwe nge-SiC, yize inani lemakethe lincane. Okulandelayo yi-graphite eboshwe nge-TaC, enikeza ukumelana okungcono kokugqwala kwamakhemikhali kune-graphite engenalutho noma i-graphite eboshwe nge-SiC, kodwa ibiza kakhulu futhi isesezigabeni zokuqala zokuthuthukiswa. Njengamanje, izinkampani zasekhaya ezifanaI-semiconductor ye-Liufang, I-Semicera, futhiI-Vetek Semiconductorbahileleke ku-R&D kule ndawo.
Isikhathi sokuthunyelwe: Meyi-20-2026