Iyini i-CVD SiC Coating?
I-Chemical vapor deposition (CVD) inqubo yokufaka i-vacuum esetshenziselwa ukukhiqiza izinto eziqinile ezihlanzekile. Le nqubo ivame ukusetshenziswa emkhakheni wokukhiqiza i-semiconductor ukwenza amafilimu amancanyana phezu kwama-wafers. Enqubweni yokulungiselela i-silicon carbide nge-CVD, i-substrate ivezwa ku-precursors eyodwa noma ngaphezulu eguquguqukayo, esabela ngamakhemikhali ebusweni be-substrate ukuze ifake amadiphozithi e-silicon carbide afunekayo. Phakathi kwezindlela eziningi zokulungiselela izinto ze-silicon carbide, imikhiqizo elungiselelwe ukufakwa komhwamuko wamakhemikhali inokufana okuphezulu nokuhlanzeka, futhi le ndlela inokulawuleka okuqinile kwenqubo. I-CVD silicon carbide materials inenhlanganisela eyingqayizivele yezinto ezinhle kakhulu ezishisayo, zikagesi kanye namakhemikhali, okuzenza zifaneleke kakhulu ukusetshenziswa embonini ye-semiconductor lapho kudingeka khona izinto zokusebenza eziphezulu. Izingxenye ze-CVD silicon carbide zisetshenziswa kakhulu emishinini yokufaka i-etching, imishini ye-MOCVD, imishini ye-Si epitaxial kanye nemishini ye-SiC epitaxial, imishini yokucubungula ukushisa okusheshayo neminye imikhakha.
Lesi sihloko sigxile ekuhlaziyeni ikhwalithi yamafilimu amancanyana akhule emazingeni okushisa ahlukene ngesikhathi sokulungiswaI-CVD SiC coating, ukuze ukhethe izinga lokushisa lenqubo elifanele kakhulu. Ukuhlolwa kusebenzisa i-graphite njenge-substrate kanye ne-trichloromethylsilane (MTS) njengegesi yomthombo wokusabela. I-SiC coating ifakwe inqubo ye-CVD enengcindezi ephansi, kanye ne-micromorphology ye-I-CVD SiC coatingibonwa ngokuskena i-electron microscopy ukuze ihlaziye ukuminyana kwesakhiwo.
Ngenxa yokuthi izinga lokushisa elingaphezulu kwe-graphite substrate liphezulu kakhulu, igesi ephakathi izokhishwa futhi ikhishwe endaweni engaphansi, futhi ekugcineni i-C ne-Si esele endaweni engaphansi izokwakha isigaba esiqinile se-SiC ukuze kwakhiwe i-SiC coating. Ngokusho kwenqubo yokukhula kwe-CVD-SiC engenhla, kungabonakala ukuthi izinga lokushisa lizothinta ukusabalalisa kwegesi, ukubola kwe-MTS, ukwakheka kwamaconsi kanye nokuchithwa nokukhishwa kwegesi ephakathi, ngakho-ke izinga lokushisa lokubeka lizodlala indima ebalulekile ku-morphology ye-SiC coating. I-microscopic morphology ye-coating iwukubonakaliswa okunembile kakhulu kokuminyana kwentolo. Ngakho-ke, kuyadingeka ukutadisha umphumela wamazinga okushisa ahlukene e-deposition ku-morphology encane ye-CVD SiC coating. Njengoba i-MTS ingabola futhi ifake uqweqwe lwe-SiC phakathi kuka-900 ~ 1600 ℃, lokhu kuhlolwa kukhetha amazinga okushisa amahlanu e-900℃, 1000℃, 1100℃, 1200℃ kanye no-1300℃ ukuze kulungiselelwe ukunamathela kwe-SiC ukuze kufundwe umthelela we-CVD-SiC ku-coating. Imingcele ethile ikhonjiswe kuThebula 3. Umfanekiso 2 ubonisa i-microscopic morphology ye-CVD-SiC coating ekhuliswe emazingeni okushisa ahlukene.
Uma izinga lokushisa lokubeka liyi-900 ℃, yonke i-SiC ikhula ibe yizimo zefayibha. Kungabonakala ukuthi ububanzi be-fiber eyodwa bumayelana ne-3.5μm, futhi i-aspect ratio yayo imayelana ne-3 (<10). Ngaphezu kwalokho, yakhiwe izinhlayiya ezingenakubalwa ze-nano-SiC, ngakho-ke iyingxenye yesakhiwo se-polycrystalline SiC, ehlukile kuma-nanowires e-SiC yendabuko kanye namadevu e-SiC e-crystal eyodwa. Le SiC ene-fibrous iyisici sesakhiwo esibangelwa imingcele yenqubo engenangqondo. Kungabonakala ukuthi ukwakheka kwalesi sigqoko se-SiC sikhululekile, futhi kukhona inani elikhulu lama-pores phakathi kwe-SiC ene-fibrous, futhi ukuminyana kuphansi kakhulu. Ngakho-ke, lokhu kushisa akufanelekile ukulungiswa kwezingubo eziminyene ze-SiC. Ngokuvamile, ukukhubazeka kwesakhiwo se-Fibrous SiC kubangelwa izinga lokushisa eliphansi kakhulu lokubeka. Emazingeni okushisa aphansi, ama-molecule amancane akhangisiwe ebusweni be-substrate anamandla aphansi kanye nekhono elibi lokufuduka. Ngakho-ke, ama-molecule amancane athambekele ekufudukeni futhi akhule aye endaweni ephansi kakhulu yamandla wamahhala wezinhlamvu ze-SiC (njengesihloko sokusanhlamvu). Ukukhula okuqhubekayo okuqondisayo kugcina kudala amaphutha esakhiwo se-SiC ene-fibrous.
Ukulungiswa kwe-CVD SiC Coating:
Okokuqala, i-graphite substrate ifakwa esithandweni se-vacuum esiphezulu futhi igcinwe ku-1500 ℃ ihora elingu-1 endaweni ye-Ar ukuze kukhishwe umlotha. Khona-ke i-graphite block iyasikwa ibe yibhulokhi engu-15x15x5mm, futhi ingaphezulu lebhokisi le-graphite lipholishwa nge-sandpaper ye-1200-mesh ukuze kuqedwe izimbotshana ezingaphezulu ezithinta ukufakwa kwe-SiC. I-graphite block ephathwayo igezwa nge-anhydrous ethanol namanzi acwecwe, bese ifakwa kuhhavini ongu-100 ℃ ukuze yomiswe. Ekugcineni, i-graphite substrate ibekwa endaweni yokushisa enkulu yesithando somlilo se-tubular ukuze kufakwe i-SiC. Umdwebo wohlelo lwesistimu yokubeka umhwamuko wamakhemikhali uboniswa kuMfanekiso 1.
II-CVD SiC coatingyabonwa ngokuskena i-electron microscopy ukuze ihlaziye usayizi wezinhlayiyana zayo nokuminyana. Ngaphezu kwalokho, izinga lokufakwa kwe-SiC coating libalwe ngokuvumelana nefomula engezansi: VSiC=(m2-m1)/(Sxt)x100% VSiC=Izinga lokubeka; m2–mass of coating sample (mg); m1–ubunzima be-substrate (mg); Indawo engaphansi kuka-S ye-substrate (mm2); t-isikhathi sokufakwa (h). I-CVD-SiC iyinkimbinkimbi, futhi inqubo ingafinyezwa kanje: ekushiseni okuphezulu, i-MTS izoba nokubola okushisayo ukuze yenze umthombo wekhabhoni kanye ne-silicon umthombo wama-molecule amancane. Umthombo we-carbon ama-molecule amancane ikakhulukazi ahlanganisa i-CH3, i-C2H2 ne-C2H4, futhi umthombo we-silicon ama-molecule amancane ikakhulukazi ahlanganisa i-SiCI2, i-SiCI3, njll.; le mithombo ye-carbon kanye nomthombo we-silicon ama-molecule amancane ayobe esethuthelwa phezu kwe-graphite substrate ngegesi ethwala kanye negesi ehlanjululwe, bese la ma-molecule amancane azokhangiswa ebusweni be-substrate ngendlela yokukhangisa, bese kuvela ukusabela kwamakhemikhali phakathi kwama-molecule amancane ukuze akhe amaconsi amancane azokhula kancane kancane, futhi kancane kancane aqhume. imikhiqizo ephakathi nendawo (igesi ye-HCl); Lapho izinga lokushisa likhuphukela ku-1000 ℃, ukuminyana kwe-SiC coating kuthuthukiswa kakhulu. Kungabonakala ukuthi iningi lokumboza lakhiwe ngezinhlamvu ze-SiC (usayizi ongaba ngu-4μm), kodwa ezinye iziphambeko ze-SiC ezine-fibrous ziyatholakala, okubonisa ukuthi kusekhona ukukhula okuqondile kwe-SiC kulokhu kushisa, futhi ukumboza akukabi minyene ngokwanele. Lapho izinga lokushisa likhuphuka lifinyelela ku-1100 ℃, kungabonakala ukuthi ukunamathela kwe-SiC kuminyene kakhulu, futhi amaphutha e-Fibrous SiC anyamalele ngokuphelele. I-coating yenziwe ngezinhlayiya ze-SiC ezimise okwe-droplet ezinobubanzi obungaba ngu-5 ~ 10μm, ezihlanganiswe ngokuqinile. Ubuso bezinhlayiya bukhulu kakhulu. Yakhiwe ngezinhlamvu ezingenakubalwa ze-nano-scale SiC. Eqinisweni, inqubo yokukhula kwe-CVD-SiC ku-1100 ℃ isilawulwa ukudluliswa okukhulu. Ama-molecule amancane akhangisiwe ebusweni be-substrate anamandla anele nesikhathi soku-nucleate futhi akhule abe izinhlamvu ze-SiC. Izinhlamvu ze-SiC ngokulinganayo zakha amaconsi amakhulu. Ngaphansi kwesenzo samandla angaphezulu, amaconsi amaningi abonakala eyindilinga, futhi amaconsi ahlanganiswe ngokuqinile ukuze enze i-SiC eminyene. Lapho izinga lokushisa likhuphuka lifinyelela ku-1200 ℃, ukunamathela kwe-SiC nakho kuminyene, kodwa i-SiC morphology iba ngama-multi-ridged futhi ingaphezulu le-coating libonakala lilukhuni. Lapho izinga lokushisa likhuphuka lifinyelela ku-1300℃, inani elikhulu lezinhlayiya eziyindilinga ezivamile ezinobubanzi obungaba ngu-3μm zitholakala ebusweni be-graphite substrate. Lokhu kungenxa yokuthi kulokhu kushisa, i-SiC iye yaguqulwa yaba yi-nucleation yesigaba segesi, futhi izinga lokubola kwe-MTS lishesha kakhulu. Ama-molecule amancane asabele futhi ane-nucleated ukuze akhe izinhlamvu ze-SiC ngaphambi kokuba zikhangiswe endaweni engaphansi. Ngemva kokuba izinhlamvu zakha izinhlayiya eziyindilinga, zizowela ngezansi, ekugcineni ziphumele ekuhlanganisweni kwezinhlayiyana ze-SiC ezinobunzima obumpofu. Ngokusobala, i-1300 ℃ ayikwazi ukusetshenziswa njengezinga lokushisa le-SiC eliminyene. Ukuqhathanisa okuphelele kukhombisa ukuthi uma kufanele kulungiswe ukunamathela kwe-SiC eminyene, izinga lokushisa elilungile lokubeka i-CVD ngu-1100 ℃.
Umfanekiso wesi-3 ubonisa izinga lokubekwa kwezingubo ze-CVD SiC emazingeni okushisa ahlukene okubekwa. Njengoba izinga lokushisa lokubeka likhuphuka, izinga lokubeka i-SiC coating liyancipha kancane kancane. Izinga lokubeka ku-900 ° C lingu-0.352 mg·h-1/mm2, futhi ukukhula okuqondile kwemicu kuholela esilinganisweni esisheshayo sokubeka. Izinga le-deposition ye-coating enobuningi obukhulu kakhulu ngu-0.179 mg·h-1/mm2. Ngenxa yokufakwa kwezinye izinhlayiya ze-SiC, izinga lokubeka ku-1300 ° C liphansi kakhulu, kuphela i-0.027 mg·h-1/mm2. Isiphetho: Izinga lokushisa elingcono kakhulu lokubeka i-CVD ngu-1100 ℃. Izinga lokushisa eliphansi likhuthaza ukukhula okuqondile kwe-SiC, kuyilapho izinga lokushisa eliphezulu libangela i-SiC ukuthi ikhiqize ukufakwa komhwamuko futhi ibangele ukunamathela okuncane. Ngokukhuphuka kwezinga lokushisa lokubeka, izinga lokubeka leI-CVD SiC coatingkancane kancane iyancipha.
Isikhathi sokuthumela: May-26-2025