Kuyini i-CVD SiC Coating?
Ukufakwa kwe-chemical vapor (CVD) inqubo yokufakwa kwe-vacuum esetshenziselwa ukukhiqiza izinto eziqinile ezihlanzekile kakhulu. Le nqubo ivame ukusetshenziswa emkhakheni wokukhiqiza we-semiconductor ukwakha amafilimu amancane ebusweni be-wafers. Enkambisweni yokulungiselela i-silicon carbide yi-CVD, i-substrate ivezwa ku-volatible precursors eyodwa noma ngaphezulu, ezisabela ngamakhemikhali ebusweni be-substrate ukuze zifake amadiphozithi e-silicon carbide afunwayo. Phakathi kwezindlela eziningi zokulungiselela izinto ze-silicon carbide, imikhiqizo elungiselelwe yi-chemical vapor deposition inokufana okuphezulu nobumsulwa, futhi le ndlela inokulawulwa kwenqubo okuqinile. Izinto ze-CVD silicon carbide zinenhlanganisela eyingqayizivele yezakhiwo ezinhle kakhulu zokushisa, zikagesi kanye nezamakhemikhali, okwenza zifaneleke kakhulu ukusetshenziswa embonini ye-semiconductor lapho kudingeka khona izinto zokusebenza okuphezulu. Izingxenye ze-CVD silicon carbide zisetshenziswa kabanzi emishinini yokuqopha, imishini ye-MOCVD, imishini ye-Si epitaxial kanye nemishini ye-SiC epitaxial, imishini yokucubungula ukushisa okusheshayo kanye neminye imikhakha.
Lesi sihloko sigxile ekuhlaziyeni ikhwalithi yamafilimu amancane akhuliswe emazingeni okushisa ahlukene ngesikhathi sokulungiselelaUkugqoka kwe-CVD SiC, ukuze kukhethwe izinga lokushisa lenqubo elifanele kakhulu. Ukuhlolwa kusebenzisa i-graphite njenge-substrate kanye ne-trichloromethylsilane (MTS) njengegesi yomthombo wokusabela. Isembozo se-SiC sibekwa yinqubo ye-CVD ephansi, kanye ne-micromorphology yeUkugqoka kwe-CVD SiCibonwa ngokuskena i-electron microscopy ukuze kuhlaziywe ubuningi bayo besakhiwo.
Ngenxa yokuthi izinga lokushisa lobuso be-graphite substrate liphezulu kakhulu, igesi ephakathi izokhishwa bese ikhishwa ebusweni be-substrate, futhi ekugcineni i-C ne-Si ezisele ebusweni be-substrate zizokwakha i-SiC yesigaba esiqinile ukuze zakhe i-SiC coating. Ngokusho kwenqubo yokukhula kwe-CVD-SiC engenhla, kungabonakala ukuthi izinga lokushisa lizothinta ukusabalala kwegesi, ukubola kwe-MTS, ukwakheka kwamaconsi kanye nokuphuma nokuphuma kwegesi ephakathi, ngakho izinga lokushisa lokufakwa lizodlala indima ebalulekile ekubunjweni kwe-SiC coating. I-microscopic morphology ye-coating iwukubonakaliswa okunembile kakhulu kobuningi be-coating. Ngakho-ke, kubalulekile ukutadisha umphumela wamazinga okushisa ahlukene okufakwa ku-morphology ye-microscopic ye-CVD SiC coating. Njengoba i-MTS ingabola futhi ibeke ungqimba lwe-SiC phakathi kuka-900 ~ 1600℃, lokhu kuhlola kukhetha amazinga okushisa amahlanu okubekwa angu-900℃, 1000℃, 1100℃, 1200℃ kanye no-1300℃ ukuze kulungiselelwe ungqimba lwe-SiC ukuze kufundwe umphumela wokushisa kungqimba lwe-CVD-SiC. Amapharamitha athile aboniswe kuThebula 3. Isibalo 2 sibonisa isimo se-microscopic sokufakwa kwe-CVD-SiC okukhuliswe emazingeni okushisa ahlukene okubekwa.
Uma izinga lokushisa lokufakwa lingama-900℃, yonke i-SiC ikhula ibe yizimo zefayibha. Kungabonakala ukuthi ububanzi befayibha eyodwa bungaba ngu-3.5μm, kanti isilinganiso sayo sicishe sibe ngu-3 (<10). Ngaphezu kwalokho, yakhiwe ngezinhlayiya ze-nano-SiC ezingenakubalwa, ngakho-ke ingeyesakhiwo se-polycrystalline SiC, esihlukile kuma-nanowires e-SiC endabuko kanye nama-single-crystal SiC whiskers. Le SiC ene-fibrous iyisiphako sesakhiwo esibangelwa yimingcele yenqubo engacabangeki. Kungabonakala ukuthi isakhiwo salesi simbozo se-SiC sikhululekile, futhi kunenqwaba yama-pores phakathi kwe-fibrous SiC, futhi ubuningi buphansi kakhulu. Ngakho-ke, leli zinga lokushisa alifanele ukulungiswa kwezimbozo ze-SiC ezixinene. Ngokuvamile, amaphutha esakhiwo se-fibrous SiC abangelwa izinga lokushisa lokufakwa eliphansi kakhulu. Emazingeni okushisa aphansi, ama-molecule amancane afakwe ebusweni be-substrate anamandla aphansi kanye nekhono lokufuduka elibi. Ngakho-ke, ama-molecule amancane avame ukufuduka futhi akhule abe amandla aphansi kakhulu angenawo umphezulu wezinhlamvu ze-SiC (njengengxenye yenhlama). Ukukhula okuqhubekayo okuqondiswe ekugcineni kudala amaphutha esakhiwo se-SiC esine-fibrous.
Ukulungiswa kwe-CVD SiC Coating:
Okokuqala, i-graphite substrate ifakwa esithandweni sokushisa okuphezulu se-vacuum bese igcinwa ku-1500℃ ihora eli-1 emoyeni we-Ar ukuze kususwe umlotha. Bese i-graphite block inqunywa ibe yi-block engu-15x15x5mm, bese ubuso be-graphite block bupholishwa nge-sandpaper engu-1200-mesh ukuze kususwe ama-pores angaphezulu athinta ukufakwa kwe-SiC. I-graphite block ephathwayo igezwa nge-anhydrous ethanol namanzi acwengekile, bese ifakwa kuhhavini ku-100℃ ukuze yomiswe. Ekugcineni, i-graphite substrate ifakwa endaweni yokushisa eyinhloko yesithando se-tubular ukuze kufakwe i-SiC. Umdwebo we-schematic wesistimu yokufakwa komphunga wamakhemikhali uboniswe ku-Figure 1.
IUkugqoka kwe-CVD SiCkwabonwa ngokuskena i-electron microscopy ukuze kuhlaziywe usayizi wezinhlayiya zayo kanye nobuningi bayo. Ngaphezu kwalokho, izinga lokufakwa kwe-SiC coating labalwa ngokwefomula engezansi: I-VSiC=(m2-m1)/(Sxt)x100% I-VSiC=Izinga lokufakwa; i-m2–isisindo sesampula yokumboza (mg); m1–isisindo se-substrate (mg); Indawo yobuso obungu-S ye-substrate (mm2); t-isikhathi sokufaka (h). I-CVD-SiC iyinkimbinkimbi kakhulu, futhi inqubo ingafingqwa kanje: ekushiseni okuphezulu, i-MTS izobola ngokushisa ukuze yakhe ama-molecule amancane omthombo wekhabhoni kanye nama-molecule amancane omthombo we-silicon. Ama-molecule amancane omthombo wekhabhoni afaka kakhulu i-CH3, i-C2H2 kanye ne-C2H4, kanti ama-molecule amancane omthombo we-silicon afaka kakhulu i-SiCI2, i-SiCI3, njll.; lawa ma-molecule amancane omthombo wekhabhoni kanye nomthombo we-silicon azothuthwa aye ebusweni be-substrate ye-graphite yigesi ethwala kanye negesi exubile, bese lawa ma-molecule amancane azomuncwa ebusweni be-substrate ngendlela yokumuncwa, bese kwenzeka ukusabela kwamakhemikhali phakathi kwama-molecule amancane ukuze kwakheke amaconsi amancane akhula kancane kancane, futhi amaconsi azohlangana, futhi ukusabela kuzohambisana nokwakheka kwemikhiqizo engaphansi (igesi ye-HCl); Uma izinga lokushisa likhuphuka lifike ku-1000 ℃, ubuningi bengubo ye-SiC buthuthuka kakhulu. Kungabonakala ukuthi iningi lengubo yakhiwe yizinhlamvu ze-SiC (cishe u-4μm ngobukhulu), kodwa kutholakala nezinye iziphambeko ze-SiC ezine-fibrous, okubonisa ukuthi kusekhona ukukhula okuqondile kwe-SiC kuleli zinga lokushisa, futhi ingubo ayikaqini ngokwanele. Lapho izinga lokushisa likhuphuka lifike ku-1100 ℃, kungabonakala ukuthi ingubo ye-SiC ixinene kakhulu, kanti iziphambeko ze-SiC ezine-fibrous sezinyamalale ngokuphelele. Ingubo yakhiwe yizinhlayiya ze-SiC ezimise okwe-droplet ezinobubanzi obungaba ngu-5 ~ 10μm, ezihlanganiswe ngokuqinile. Ubuso bezinhlayiya buqinile kakhulu. Yakhiwe yizinhlayiya ze-SiC ezingenakubalwa. Eqinisweni, inqubo yokukhula kwe-CVD-SiC ku-1100 ℃ isilawulwa ukudluliselwa kwesisindo. Ama-molecule amancane afakwe ebusweni be-substrate anamandla anele nesikhathi sokukhulisa abe yizinhlamvu ze-SiC. Izinhlayiya ze-SiC zakha amaconsi amakhulu ngokufanayo. Ngaphansi kwesenzo samandla angaphezulu, iningi lamaconsi libonakala liyindilinga, futhi amaconsi ahlanganiswa ngokuqinile ukuze akhe ungqimba oluqinile lwe-SiC. Uma izinga lokushisa likhuphukela ku-1200℃, isembozo se-SiC naso siminyene, kodwa isimo se-SiC siba nama-ridge amaningi futhi ubuso besembozo bubonakala buqinile. Lapho izinga lokushisa likhuphuka lifika ku-1300℃, inani elikhulu lezinhlayiya ezijwayelekile eziyindilinga ezinobubanzi obungaba ngu-3μm zitholakala ebusweni be-substrate ye-graphite. Lokhu kungenxa yokuthi kuleli zinga lokushisa, i-SiC iguqulwe yaba yi-nucleation yesigaba segesi, futhi izinga lokubola kwe-MTS lishesha kakhulu. Ama-molecule amancane asabela futhi ahlanganisa i-nucleation ukuze akhe izinhlamvu ze-SiC ngaphambi kokuba zifakwe ebusweni be-substrate. Ngemva kokuba izinhlamvu zakhe izinhlayiya eziyindilinga, zizowela ngaphansi, ekugcineni kuholele ekuhlanganiseni kwezinhlayiya ze-SiC okuxekethile okunobuningi obuphansi. Ngokusobala, i-1300℃ ayikwazi ukusetshenziswa njengokushisa okwakhayo kwesembozo se-SiC esiminyene. Ukuqhathanisa okuphelele kukhombisa ukuthi uma kuzolungiswa isembozo se-SiC esiminyene, izinga lokushisa elihle kakhulu lokufakwa kwe-CVD lingu-1100℃.
Isithombe 3 sibonisa izinga lokufakwa kwezimbozo ze-CVD SiC emazingeni okushisa ahlukene okufakwa. Njengoba izinga lokushisa lokufakwa likhuphuka, izinga lokufakwa kwezimbozo ze-SiC liyancipha kancane kancane. Izinga lokufakwa kwezimbozo ku-900°C lingu-0.352 mg·h-1/mm2, futhi ukukhula okuqondile kwezindwangu kuholela esilinganisweni sokufakwa esisheshayo. Izinga lokufakwa kwezimbozo ezinesisindo esiphezulu lingu-0.179 mg·h-1/mm2. Ngenxa yokufakwa kwezinye izinhlayiya ze-SiC, izinga lokufakwa kwezimbozo ku-1300°C liphansi kakhulu, lingu-0.027 mg·h-1/mm2 kuphela. Isiphetho: Izinga lokushisa elihle kakhulu lokufakwa kwe-CVD lingu-1100℃. Izinga lokushisa eliphansi likhuthaza ukukhula kwe-SiC ngendlela eqondile, kuyilapho izinga lokushisa eliphezulu libangela ukuthi i-SiC ikhiqize ukufakwa komusi futhi kuholele ekumbozweni okuncane. Ngokukhuphuka kwezinga lokushisa lokufakwa, izinga lokufakwa kwe-Ukugqoka kwe-CVD SiCkancane kancane kuncipha.
Isikhathi sokuthunyelwe: Meyi-26-2025