Isiphumo samaqondo obushushu ahlukeneyo kuKhulo lwe-CVD SiC Coating

Yintoni iCVD SiC Coating?

I-Chemical vapor deposition (CVD) yinkqubo yokubeka ivacuum esetyenziselwa ukuvelisa izinto eziqinileyo ezicocekileyo. Le nkqubo ihlala isetyenziswa kwindawo yokuvelisa i-semiconductor ukwenza iifilimu ezibhityileyo kumphezulu wee-wafers. Kwinkqubo yokulungiselela i-silicon carbide nge-CVD, i-substrate ibonakaliswe kwi-precursors enye okanye ngaphezulu eguquguqukayo, esabela ngekhemikhali kumphezulu we-substrate ukuze ifake iidiphozithi ezifunwayo ze-silicon carbide. Phakathi kweendlela ezininzi zokulungiselela izinto ze-silicon carbide, iimveliso ezilungiselelwe yi-chemical vapor deposition zinokufana okuphezulu kunye nokucoceka, kwaye le ndlela inokulawulwa kwenkqubo eyomeleleyo. Izinto ze-CVD silicon carbide zinendibaniselwano ekhethekileyo yeempawu ezibalaseleyo zokushisa, zombane kunye neekhemikhali, ezizenza zifaneleke kakhulu ukusetyenziswa kwishishini le-semiconductor apho kufuneka izinto zokusebenza eziphezulu. I-CVD silicon carbide components zisetyenziswa ngokubanzi kwi-etching equipment, izixhobo ze-MOCVD, izixhobo ze-Si epitaxial kunye nezixhobo ze-SiC epitaxial, izixhobo ezikhawulezayo zokulungisa ukushisa kunye nezinye iindawo.

Eli nqaku ligxile ekuhlalutyeni umgangatho weefilimu ezibhityileyo ezikhule kumaqondo obushushu ahlukeneyo ngexesha lokulungiselelaCVD SiC ukutyabeka, ukuze ukhethe eyona nkqubo ifanelekileyo yobushushu. Uvavanyo lusebenzisa igraphite njenge-substrate kunye ne-trichloromethylsilane (MTS) njenge-reaction source gas. I-coating ye-SiC ifakwe yinkqubo ye-CVD yoxinzelelo oluphantsi, kunye ne-micromorphology yeCVD SiC ukutyabekaijongwa ngokuskena i-electron microscopy ukuhlalutya ukuxinana kwesakhiwo.

Ngenxa yokuba ubushushu bomphezulu we-graphite substrate buphezulu kakhulu, igesi ephakathi iya kuchithwa kwaye ikhutshwe kwi-substrate surface, kwaye ekugqibeleni i-C kunye ne-Si eseleyo kwi-substrate surface iya kwenza i-SiC yesigaba esiqinileyo ukwenza i-SiC coating. Ngokwenkqubo yokukhula kwe-CVD-SiC engentla, kunokubonwa ukuba ukushisa kuya kuchaphazela ukusasazwa kwegesi, ukubola kwe-MTS, ukubunjwa kwamaconsi kunye nokuchithwa kunye nokukhutshwa kwegesi ephakathi, ngoko ukushisa kwe-deposition kuya kudlala indima ephambili kwi-morphology ye-coating ye-SiC. I-microscopic morphology yokwaleka yeyona nto ibonakalayo yokubonakaliswa koxinzelelo lwengubo. Ke ngoko, kuyafuneka ukuba kufundwe isiphumo samaqondo obushushu ahlukeneyo kwi-microscopic morphology ye-CVD SiC coating. Ekubeni i-MTS inokubola kwaye ifake i-SiC yokwambathisa phakathi kwe-900 ~ 1600 ℃, olu vavanyo lukhetha amaqondo okushisa amahlanu e-900 ℃, 1000 ℃, 1100 ℃, 1200 ℃ kunye ne-1300 ℃ ukulungiselela ukulungiswa kwe-SiC yokwambathisa ukufunda isiphumo sobushushu kwi-CVD-Site. Iiparamitha ezithile ziboniswe kwiThebhile 3. Umzobo we-2 ubonisa i-microscopic morphology ye-CVD-SiC coating ekhulile kumaqondo okushisa ahlukeneyo.

Xa iqondo lobushushu lokubeka liyi 900℃, yonke iSiC ikhula ibeyimilo yefibre. Ingabonwa ukuba ububanzi befiber enye malunga ne-3.5μm, kwaye umlinganiselo wayo umalunga ne-3 (<10). Ngaphezu koko, iqulunqwe ngamasuntswana angenakubalwa e-nano-SiC, ngoko ke iyinxalenye yesakhiwo se-SiC se-polycrystalline, esahlukileyo kwi-nanowires ye-SiC yendabuko kunye ne-crystal-crystal whiskers ye-SiC. Le SiC ye-fibrous yintlupheko yesakhiwo ebangelwa iiparameters zenkqubo engenangqiqo. Kuyabonakala ukuba ukwakhiwa kwesi sigqubuthelo se-SiC sikhululekile, kwaye kukho inani elikhulu leepores phakathi kwe-SiC ene-fibrous, kwaye ubuninzi buphantsi kakhulu. Ngoko ke, eli qondo lokushisa alifanelekanga ukulungiswa kweengubo ezixineneyo ze-SiC. Ngesiqhelo, iziphene zesakhiwo se-Fibrous SiC zibangelwa liqondo lobushushu eliphantsi kakhulu. Kwiqondo lokushisa eliphantsi, iimolekyuli ezincinci ezibhengezwe kumphezulu we-substrate zinamandla aphantsi kunye nokukwazi ukufuduka. Ke ngoko, iimolekyuli ezincinci zivame ukufuduka kwaye zikhule ziye kwindawo ephantsi yamandla asimahla eenkozo zeSiC (ezifana nencam yeenkozo). Ukukhula okuqhubelekayo okukhokelela ekugqibeleni kwenza iziphene zesakhiwo se-SiC ene-fibrous.

Ukulungiswa kwe-CVD SiC Coating:

Okokuqala, i-graphite substrate ifakwe kwisithando somlilo esiphezulu kwaye igcinwe kwi-1500 ℃ nge-1h kwi-Armosphere ye-Ar yokususa uthuthu. Emva koko ibhloko yegraphite inqunyulwe kwibhloko ye-15x15x5mm, kwaye umphezulu webhloko yegraphite upholiswe nge-sandpaper ye-1200-mesh ukuphelisa iipores ezingaphezulu ezichaphazela ukubekwa kweSiC. Ibhloko yegraphite ephathwayo ihlanjwa nge-ethanol ye-anhydrous kunye namanzi adibeneyo, kwaye emva koko ifakwe kwi-oven kwi-100 ℃ ukuze yomiswe. Ekugqibeleni, i-graphite substrate ifakwe kwindawo yokushisa ephambili ye-tubular furnace ye-SiC deposition. Umzobo wesicwangciso senkqubo yokubeka umphunga wekhemikhali uboniswe kuMfanekiso 1.

ICVD SiC ukutyabekayabonwa ngokuskena i-electron microscopy ukuhlalutya ubungakanani bamasuntswana kunye noxinaniso. Ukongeza, ireyithi yokubeka i-Coating ye-SiC ibalwe ngokwefomula engezantsi: VSiC=(m2-m1)/(Sxt)x100% VSiC=Umlinganiselo wokubekwa; m2-ubunzima besampulu yokwambathisa (mg); m1–ubunzima be substrate (mg); Ummandla we-S we-substrate (mm2); t-ixesha lokubekwa (h).   I-CVD-SiC inzima kakhulu, kwaye inkqubo ingashwankathelwa ngolu hlobo lulandelayo: kwiqondo lokushisa eliphezulu, i-MTS iya kudlula ukubola kwe-thermal ukwenza umthombo wekhabhoni kunye ne-silicon umthombo we-molecule ezincinci. Umthombo wekhabhoni iimolekyuli ezincinci zibandakanya i-CH3, i-C2H2 kunye ne-C2H4, kunye nomthombo we-silicon iimolekyuli ezincinci ziquka i-SiCI2, i-SiCI3, njl.; Le mithombo yekhabhoni kunye ne-silicon yemithombo yeemolekyuli ezincinci ziya kuthuthelwa kumphezulu we-graphite substrate yigesi ethwala kunye nerhasi edibeneyo, kwaye ke ezi molekyuli zincinci ziya kubhengezwa kumphezulu we-substrate ngohlobo lwe-adsorption, kwaye ke ukuphendula kweekhemikhali kuya kwenzeka phakathi kweemolekyuli ezincinci ukwenza amathontsi amancinci kwaye aya kukhula ngokuthe ngcembe, kunye nokwakheka kwamathontsi aya kukhula ngokuthe ngcembe. imveliso ephakathi (igesi yeHCl); Xa ubushushu buphakama ukuya kwi-1000 ℃, ukuxinana kwengubo yeSiC kuphucula kakhulu. Kuyabonakala ukuba uninzi lotyatyazo lwenziwe ngeenkozo ze-SiC (malunga ne-4μm ngobukhulu), kodwa ezinye iziphene ze-Fibrous ze-SiC nazo zifunyenwe, nto leyo ebonisa ukuba kusekho ukukhula kolwalathiso lwe-SiC kobu bushushu, kwaye ukugquma akukabikho xinene ngokwaneleyo. Xa ubushushu buphakama ukuya kwi-1100 ℃, kunokubonwa ukuba i-SiC coating ixinene kakhulu, kwaye iziphene ze-Fibrous SiC ziye zanyamalala ngokupheleleyo. Ingubo iqulethwe ngamaqhekeza e-SiC ane-droplet enobubanzi obumalunga ne-5 ~ 10μm, ehlanganiswe ngokuqinileyo. Umphezulu wamasuntswana arhabaxa kakhulu. Iqulunqwe ngeenkozo zeSiC ezingenakubalwa ze-nano-scale. Enyanisweni, inkqubo yokukhula kwe-CVD-SiC kwi-1100 ℃ iye yalawulwa ngokugqithisela okukhulu. Iimolekyuli ezincinci ezibhengezwa kumphezulu we-substrate zinamandla okwaneleyo kunye nexesha lokunyula kwaye zikhule zibe ziinkozo zeSiC. Iinkozo zeSiC ngokufanayo zenza amathontsi amakhulu. Ngaphantsi kwesenzo samandla angaphezulu, amaninzi amaconsi abonakala e-spherical, kwaye amaconsi ahlanganiswe ngokuqinileyo ukwenza i-coating ye-SiC exineneyo. Xa iqondo lobushushu linyuka liye kutsho kwi-1200℃, i-SiC coating nayo ixinene, kodwa i-SiC morphology iba mininzi kwaye umphezulu we-coating ubonakala urhabaxa. Xa ubushushu bonyuka ukuya kwi-1300℃, inani elikhulu lamasuntswana aqhelekileyo angqukuva anobubanzi obumalunga ne-3μm afunyanwa kumphezulu we-graphite substrate. Oku kungenxa yokuba kule qondo lokushisa, i-SiC iguqulwe ibe yi-nucleation yesigaba segesi, kwaye izinga lokubola kwe-MTS likhawuleza kakhulu. Iimolekyuli ezincinci ziye zasabela kwaye ze-nucleated ukwenza iinkozo ze-SiC ngaphambi kokuba zibhengezwe kumphezulu we-substrate. Emva kokuba iinkozo zenze amasuntswana angama-spherical, ziya kuwa ngaphantsi, ekugqibeleni zibangele i-SiC particle coating kunye noxinaniso olubi. Ngokucacileyo, i-1300 ℃ ayinakusetyenziswa njengobushushu bokwenza i-coating ye-SiC eshinyeneyo. Uthelekiso olubanzi lubonisa ukuba ukuba i-SiC eshinyeneyo iyalungiswa kufuneka ilungiswe, elona qondo lobushushu le-CVD liyi-1100℃.

Umzobo wesi-3 ubonisa izinga lokubekwa kweengubo ze-CVD SiC kumaqondo obushushu ahlukeneyo. Njengoko iqondo lokushisa linyuka, izinga lokubeka i-SiC coating liyancipha ngokuthe ngcembe. Izinga lokubeka kwi-900 ° C ngu-0.352 mg · h-1 / mm2, kwaye ukukhula kolwalathiso lweefibers kukhokelela kwisantya esikhawulezayo sokubeka. Izinga lokubeka i-coating kunye noxinano oluphezulu ngu-0.179 mg · h-1 / mm2. Ngenxa yokubekwa kwezinye iinqununu ze-SiC, izinga lokubeka kwi-1300 ° C liphantsi, kuphela i-0.027 mg · h-1 / mm2.   Ukuqukumbela: Obona bushushu be-CVD bugqwesileyo yi-1100℃. Ukushisa okuphantsi kukhuthaza ukukhula kwe-SiC, ngelixa ubushushu obuphezulu bubangela ukuba i-SiC ivelise ukuchithwa komphunga kwaye kubangele ukugquma okuncinci. Ngokunyuka kweqondo lokushisa lokubeka, izinga lokubekaCVD SiC ukutyabekaiyancipha ngokuthe ngcembe.