Yintoni iCVD SiC Coating?
Ukufakwa komphunga wekhemikhali (i-CVD) yinkqubo yokufakwa kwe-vacuum esetyenziselwa ukuvelisa izinto eziqinileyo ezicocekileyo kakhulu. Le nkqubo idla ngokusetyenziswa kwicandelo lokuvelisa i-semiconductor ukwenza iifilimu ezincinci kumphezulu wee-wafers. Kwinkqubo yokulungiselela i-silicon carbide yi-CVD, i-substrate ivezwa kwi-volatible precursors enye okanye ezingaphezulu, ezisabela ngokweekhemikhali kumphezulu we-substrate ukuze zifake iidiphozithi ze-silicon carbide ezifunwayo. Phakathi kweendlela ezininzi zokulungiselela izixhobo ze-silicon carbide, iimveliso ezilungiselelwe yi-chemical vapor deposition zinobunye obuphezulu kunye nobunyulu, kwaye le ndlela inokulawulwa okuqinileyo kwenkqubo. Izixhobo ze-CVD silicon carbide zinomdibaniso owahlukileyo weempawu ezibalaseleyo zobushushu, zombane kunye neekhemikhali, nto leyo eyenza ukuba zifaneleke kakhulu ukusetyenziswa kwishishini le-semiconductor apho kufuneka khona izixhobo zokusebenza okuphezulu. Izixhobo ze-CVD silicon carbide zisetyenziswa kakhulu kwizixhobo zokugrumba, izixhobo ze-MOCVD, izixhobo ze-Si epitaxial kunye nezixhobo ze-SiC epitaxial, izixhobo zokucubungula ubushushu ngokukhawuleza kunye nezinye iindawo.
Eli nqaku ligxile ekuhlalutyeni umgangatho weefilimu ezincinci ezikhuliswe kumaqondo obushushu ahlukeneyo ngexesha lokulungiselelaUgqubuthelo lwe-CVD SiC, ukuze kukhethwe ubushushu benkqubo obufanelekileyo. Olu vavanyo lusebenzisa i-graphite njenge-substrate kunye ne-trichloromethylsilane (MTS) njengegesi yomthombo wempendulo. I-SiC coating ifakwa yinkqubo ye-CVD enoxinzelelo oluphantsi, kunye ne-micromorphology yeUgqubuthelo lwe-CVD SiCijongwa ngokuskena imakroskopu ye-electron ukuze kuhlalutywe uxinano lwayo lwesakhiwo.
Ngenxa yokuba ubushushu bomphezulu we-graphite substrate buphezulu kakhulu, igesi ephakathi iya kususwa kwaye ikhutshwe kumphezulu we-substrate, kwaye ekugqibeleni i-C kunye ne-Si eziseleyo kumphezulu we-substrate ziya kwenza i-SiC yesigaba esiqinileyo ukwenza i-SiC coating. Ngokwenkqubo yokukhula kwe-CVD-SiC engentla, kunokubonwa ukuba ubushushu buya kuchaphazela ukusasazeka kwegesi, ukubola kwe-MTS, ukwakheka kwamaconsi kunye nokuphuma kunye nokukhutshwa kwegesi ephakathi, ngoko ke ubushushu bokufakwa buya kudlala indima ebalulekileyo kwi-morphology ye-SiC coating. I-morphology ye-microscopic ye-coating yeyona nto ibonakalayo yobuninzi be-coating. Ke ngoko, kuyimfuneko ukufunda impembelelo yobushushu obahlukeneyo be-deposition kwi-morphology ye-microscopic ye-CVD SiC coating. Ekubeni i-MTS inokubola kwaye ifake i-SiC coating phakathi kwe-900 ~ 1600℃, olu vavanyo lukhetha amaqondo obushushu amahlanu okubeka i-900℃, 1000℃, 1100℃, 1200℃ kunye ne-1300℃ ukulungiselela i-SiC coating ukuze kufundwe impembelelo yobushushu kwi-CVD-SiC coating. Iiparameter ezithile ziboniswe kwiTheyibhile 3. Umfanekiso 2 ubonisa imo ye-microscopic ye-CVD-SiC coating ekhuliswe kumaqondo obushushu ahlukeneyo okubeka i-.
Xa ubushushu bokubekwa buyi-900℃, yonke i-SiC ikhula ibe ziimo zefayibha. Kuyabonakala ukuba ububanzi befayibha enye bumalunga ne-3.5μm, kwaye umlinganiselo wayo umalunga ne-3 (<10). Ngaphezu koko, yenziwe ngamasuntswana angenakubalwa e-nano-SiC, ngoko ke ikwisakhiwo se-polycrystalline SiC, esahlukileyo kwiintambo ze-SiC zemveli kunye neentshebe ze-SiC ze-single-crystal. Le SiC ye-fibrous sisiphako solwakhiwo esibangelwa ziiparameter zenkqubo ezingenangqondo. Kuyabonakala ukuba ulwakhiwo lwale ngubo ye-SiC lukhululekile, kwaye kukho inani elikhulu lee-pores phakathi kwe-SiC ye-fibrous, kwaye uxinano luphantsi kakhulu. Ke ngoko, olu bushushu alufanelekanga ukulungiselela i-dense SiC coatings. Ngokwesiqhelo, i-fibrous SiC structure defects ibangelwa bubushushu bokubekwa obuphantsi kakhulu. Kumaqondo obushushu aphantsi, iimolekyuli ezincinci ezifakwe kumphezulu we-substrate zinamandla aphantsi kunye nokukwazi ukufuduka okubi. Ke ngoko, iimolekyuli ezincinci zihlala zihamba kwaye zikhule ziye kumandla aphantsi kakhulu angenamphezulu we-SiC grains (njengencam yengqolowa). Ukukhula okuqhubekayo kwicala ekugqibeleni kudala iziphene zesakhiwo se-SiC esine-fibrous.
Ukulungiswa kweCVD SiC Coating:
Okokuqala, i-graphite substrate ifakwa kwi-vacuum furnace enobushushu obuphezulu kwaye igcinwe kwi-1500℃ kangangeyure e-1 emoyeni we-Ar ukuze kususwe uthuthu. Emva koko i-graphite block iyasikwa ibe yi-block ye-15x15x5mm, kwaye umphezulu we-graphite block upholishwe nge-1200-mesh sandpaper ukuze kususwe ii-surface pores ezichaphazela ukufakwa kwe-SiC. I-graphite block ephathwayo ihlanjwa nge-anhydrous ethanol kunye namanzi acociweyo, ize ibekwe kwi-oven kwi-100℃ ukuze yomiswe. Ekugqibeleni, i-graphite substrate ibekwa kwindawo yobushushu ephambili ye-tubular furnace ukuze ibekwe kwi-SiC. Umzobo we-schematic wenkqubo ye-chemical vapor deposition uboniswe kuMfanekiso 1.
IUgqubuthelo lwe-CVD SiCibonwe ngokuskena imakroskopu ye-electron ukuhlalutya ubungakanani bayo besuntswana kunye noxinano. Ukongeza, izinga lokufakwa kwe-SiC coating libalwe ngokwendlela engezantsi: I-VSiC=(m2-m1)/(Sxt)x100% VSiC=Izinga lokufakwa kwesicelo; m2–ubunzima besampulu yokugquma (mg); m1–ubunzima besiseko (mg); Indawo yobuso obungu-S kwi-substrate (mm2); t-ixesha lokubeka (h). I-CVD-SiC iyinkimbinkimbi, kwaye le nkqubo ingashwankathelwa ngolu hlobo lulandelayo: kubushushu obuphezulu, i-MTS iya kubola ngobushushu ukuze yenze iimolekyuli ezincinci ze-carbon source kunye ne-silicon source. Iimolekyuli ezincinci ze-carbon source ziquka i-CH3, i-C2H2 kunye ne-C2H4, kwaye iimolekyuli ezincinci ze-silicon source ziquka i-SiCI2, i-SiCI3, njl.njl.; ezi molekyuli zincinci ze-carbon source kunye ne-silicon source ziya kuthuthwa ziye kumphezulu we-graphite substrate yi-carrier gas kunye ne-diluent gas, kwaye ezi molekyuli zincinci ziya kutsalwa kumphezulu we-substrate ngendlela ye-adsorption, kwaye emva koko kuya kwenzeka ii-chemical reactions phakathi kweemolekyuli ezincinci ukuze zenze amaconsi amancinci akhula kancinci kancinci, kwaye amaconsi aya kuhlangana, kwaye impendulo iya kukhatshwa kukwenziwa kweemveliso eziphakathi (i-HCl gas); Xa ubushushu bunyuka bufikelela kwi-1000 ℃, uxinano lwengubo yeSiC luphucuka kakhulu. Kuyabonakala ukuba uninzi lwengubo yenziwe ngeenkozo zeSiC (malunga ne-4μm ngobukhulu), kodwa kukwafunyanwa nezinye iziphene zeSiC ezine-fibrous, nto leyo ebonisa ukuba kusekho ukukhula kweSiC kwicala elithe ngqo kolu bushushu, kwaye ingubo ayikabi nkulu ngokwaneleyo. Xa ubushushu bunyuka bufikelela kwi-1100 ℃, kuyabonakala ukuba ingubo yeSiC ixinene kakhulu, kwaye iziphene zeSiC ezine-fibrous ziphelile ngokupheleleyo. Ingubo yenziwe zii-particles zeSiC ezimile okwe-droplet ezinobubanzi obumalunga ne-5 ~ 10μm, ezidityaniswe ngokuqinileyo. Umphezulu wee-particles urhabaxa kakhulu. Yenziwe ziinkozo zeSiC ezingenakubalwa. Enyanisweni, inkqubo yokukhula kweCVD-SiC kwi-1100 ℃ ilawulwa kukudluliselwa kobunzima. Iimolekyuli ezincinci ezifakwe kumphezulu we-substrate zinamandla aneleyo kunye nexesha lokukhula zibe ziinkozo zeSiC. Iinkozo zeSiC zenza amaconsi amakhulu ngokufanayo. Phantsi kwesenzo samandla omphezulu, uninzi lwamathontsi lubonakala lungqukuva, kwaye amathontsi adityaniswe ngokuqinileyo ukuze enze uqweqwe oluxineneyo lweSiC. Xa ubushushu bunyuka bufikelela kwi-1200℃, i-SiC coating nayo ixinene, kodwa i-SiC morphology iba yi-multi-ridged kwaye umphezulu we-coating ubonakala urhabaxa. Xa ubushushu bunyuka bufikelela kwi-1300℃, inani elikhulu lee-regular spherical particles ezinobubanzi obuyi-3μm zifumaneka kumphezulu we-graphite substrate. Oku kungenxa yokuba kolu bushushu, i-SiC iguqulwe yaba yi-gas phase nucleation, kwaye izinga lokubola kwe-MTS likhawuleza kakhulu. Iimolekyuli ezincinci ziye zasabela kwaye zavela kwi-nucleation ukuze zenze ii-SiC grains ngaphambi kokuba zifakwe kumphezulu we-substrate. Emva kokuba ii-grains zenze ii-spherical particles, ziya kuwa ngaphantsi, ekugqibeleni zibangele i-SiC particle coating ekhululekileyo enobunzima obuphantsi. Ngokucacileyo, i-1300℃ ayinakusetyenziswa njengobushushu bokwenza i-dense SiC coating. Uthelekiso olupheleleyo lubonisa ukuba ukuba i-dense SiC coating izakulungiswa, i-CVD deposition lobushushu obufanelekileyo yi-1100℃.
Umfanekiso 3 ubonisa izinga lokufakwa kweengubo zeCVD SiC kumaqondo obushushu ahlukeneyo okufakwa. Njengoko ubushushu bokufakwa busanda, izinga lokufakwa kweengubo zeSiC liyehla kancinci kancinci. Izinga lokufakwa kwi-900°C yi-0.352 mg·h-1/mm2, kwaye ukukhula kwefayibha kwicala elikhokela kwizinga lokufakwa ngokukhawuleza. Izinga lokufakwa kweengubo ezinoxinano oluphezulu yi-0.179 mg·h-1/mm2. Ngenxa yokufakwa kwezinye iinxalenye zeSiC, izinga lokufakwa kwi-1300°C lelona liphantsi, yi-0.027 mg·h-1/mm2 kuphela. Isiphelo: Ubushushu obuphezulu bokufaka i-CVD yi-1100℃. Ubushushu obuphantsi bukhuthaza ukukhula kwe-SiC kwicala elithile, ngelixa ubushushu obuphezulu bubangela ukuba i-SiC ivelise ukufakwa komphunga kwaye ibangele ukugquma okuncinci. Ngokunyuka kobushushu bokufaka, izinga lokufakaUgqubuthelo lwe-CVD SiCiyancipha kancinci kancinci.
Ixesha leposi: Meyi-26-2025