Kodi CVD SiC Coating ndi chiyani?
Kuyika nthunzi ya mankhwala (CVD) ndi njira yoyika vacuum yomwe imagwiritsidwa ntchito popanga zinthu zolimba zoyera kwambiri. Njirayi nthawi zambiri imagwiritsidwa ntchito m'munda wopanga ma semiconductor kuti apange mafilimu opyapyala pamwamba pa ma wafer. Pokonzekera silicon carbide ndi CVD, substrate imakumana ndi chinthu chimodzi kapena zingapo zosinthika, zomwe zimachita mankhwala pamwamba pa substrate kuti ziike ma silicon carbide omwe mukufuna. Pakati pa njira zambiri zokonzekera zinthu za silicon carbide, zinthu zomwe zimakonzedwa ndi kuika nthunzi ya mankhwala zimakhala ndi kufanana kwakukulu komanso chiyero, ndipo njira iyi ili ndi mphamvu yowongolera njira. Zipangizo za CVD silicon carbide zili ndi kuphatikiza kwapadera kwa mphamvu zabwino kwambiri zotenthetsera, zamagetsi ndi mankhwala, zomwe zimapangitsa kuti zikhale zoyenera kugwiritsidwa ntchito mumakampani opanga ma semiconductor komwe kumafunika zipangizo zogwira ntchito kwambiri. Zipangizo za CVD silicon carbide zimagwiritsidwa ntchito kwambiri mu zida zocheka, zida za MOCVD, zida za Si epitaxial ndi zida za SiC epitaxial, zida zosinthira kutentha mwachangu ndi zina.
Nkhaniyi ikuyang'ana kwambiri pakuwunika ubwino wa mafilimu opyapyala omwe amakula pa kutentha kosiyanasiyana panthawi yokonzekeraChophimba cha CVD SiC, kuti musankhe kutentha koyenera kwambiri kwa njira yogwiritsira ntchito. Kuyeseraku kumagwiritsa ntchito graphite ngati substrate ndi trichloromethylsilane (MTS) ngati mpweya wochokera ku reaction source. Chophimba cha SiC chimayikidwa ndi njira ya CVD yotsika, komanso micromorphology yaChophimba cha CVD SiCimawonedwa pofufuza maikulosikopu ya ma elekitironi kuti ione kuchuluka kwake.
Popeza kutentha kwa pamwamba pa graphite substrate kuli kwakukulu kwambiri, mpweya wapakati udzachotsedwa ndikutulutsidwa kuchokera pamwamba pa substrate, ndipo pamapeto pake C ndi Si zomwe zatsala pamwamba pa substrate zidzapanga gawo lolimba la SiC kuti zipange chophimba cha SiC. Malinga ndi njira yokulira ya CVD-SiC yomwe ili pamwambapa, zitha kuwoneka kuti kutentha kudzakhudza kufalikira kwa mpweya, kuwonongeka kwa MTS, kupangika kwa madontho ndi kutayidwa ndi kutulutsidwa kwa mpweya wapakati, kotero kutentha kwa malo osungira kudzagwira ntchito yofunika kwambiri pa mawonekedwe a chophimba cha SiC. Mawonekedwe a microscopic a chophimbacho ndi chiwonetsero chodziwika bwino cha kuchuluka kwa chophimbacho. Chifukwa chake, ndikofunikira kuphunzira momwe kutentha kosiyanasiyana kwa malo osungiramo zinthu kumakhudzira mawonekedwe a microscopic a chophimba cha CVD SiC. Popeza MTS imatha kuwola ndikuyika chophimba cha SiC pakati pa 900 ~ 1600℃, kuyesera kumeneku kumasankha kutentha kosungirako kasanu ka 900℃, 1000℃, 1100℃, 1200℃ ndi 1300℃ kokonzekera chophimba cha SiC kuti iphunzire momwe kutentha kumakhudzira chophimba cha CVD-SiC. Magawo enieni akuwonetsedwa mu Gome 3. Chithunzi 2 chikuwonetsa mawonekedwe a microscopic a chophimba cha CVD-SiC chomwe chimakula pa kutentha kosiyanasiyana.
Kutentha kwa deposition kuli 900℃, SiC yonse imakula kukhala mawonekedwe a ulusi. Zitha kuwoneka kuti m'mimba mwake mwa ulusi umodzi ndi pafupifupi 3.5μm, ndipo chiŵerengero chake ndi pafupifupi 3 (<10). Komanso, imapangidwa ndi tinthu ta nano-SiC tosawerengeka, kotero ndi ya kapangidwe ka polycrystalline SiC, komwe ndi kosiyana ndi ma nanowaya achikhalidwe a SiC ndi ndevu za SiC za single-crystal. SiC ya ulusi iyi ndi vuto la kapangidwe kake lomwe limayambitsidwa ndi magawo osamveka bwino a njira. Zitha kuwoneka kuti kapangidwe ka SiC iyi ndi yomasuka, ndipo pali ma pores ambiri pakati pa SiC ya ulusi, ndipo kuchuluka kwake ndi kochepa kwambiri. Chifukwa chake, kutentha kumeneku sikoyenera kukonzekera zophimba za SiC zokhuthala. Nthawi zambiri, zolakwika za kapangidwe ka SiC ya ulusi zimayambitsidwa ndi kutentha kochepa kwambiri kwa deposition. Pa kutentha kochepa, mamolekyu ang'onoang'ono omwe amamatira pamwamba pa substrate amakhala ndi mphamvu zochepa komanso kuthekera kosayenda bwino. Chifukwa chake, mamolekyu ang'onoang'ono amakonda kusamuka ndikukula mpaka mphamvu yotsika kwambiri yopanda pamwamba ya timbewu ta SiC (monga nsonga ya tirigu). Kukula kosalekeza kwa mbali imodzi pamapeto pake kumapanga zolakwika za kapangidwe ka SiC.
Kukonzekera kwa CVD SiC Coating:
Choyamba, gawo la graphite limayikidwa mu uvuni wa vacuum wotentha kwambiri ndipo limasungidwa pa 1500℃ kwa ola limodzi mumlengalenga wa Ar kuti lichotse phulusa. Kenako gawo la graphite limadulidwa kukhala gawo la 15x15x5mm, ndipo pamwamba pa gawo la graphite limapukutidwa ndi sandpaper ya 1200-mesh kuti lichotse ma pores pamwamba omwe amakhudza kuyika kwa SiC. Gawo la graphite lokonzedwa limatsukidwa ndi anhydrous ethanol ndi madzi osungunuka, kenako limayikidwa mu uvuni pa 100℃ kuti liume. Pomaliza, gawo la graphite limayikidwa pamalo otentha kwambiri a ng'anjo ya tubular kuti liyike SiC. Chithunzi cha schematic cha dongosolo la chemical vapor deposition system chikuwonetsedwa pa Chithunzi 1.
TheChophimba cha CVD SiCidawonedwa posanthula maikulosikopu ya ma elekitironi kuti iwunike kukula kwa tinthu tating'onoting'ono ndi kuchuluka kwake. Kuphatikiza apo, kuchuluka kwa kuyika kwa chophimba cha SiC kudawerengedwa motsatira njira iyi: VSiC=(m2-m1)/(Sxt)x100% VSiC=Chiwerengero cha kuyika; m2–kulemera kwa chitsanzo chopaka (mg); m1–kulemera kwa gawo lapansi (mg); Malo a S-pamwamba pa substrate (mm2); t - nthawi yoperekera (h). CVD-SiC ndi yovuta kwambiri, ndipo njirayi ingafotokozedwe motere: kutentha kwambiri, MTS idzawonongeka ndi kutentha kuti ipange mamolekyu ang'onoang'ono ochokera ku carbon source ndi silicon source. Mamolekyu ang'onoang'ono ochokera ku carbon source makamaka akuphatikizapo CH3, C2H2 ndi C2H4, ndipo mamolekyu ang'onoang'ono ochokera ku silicon source makamaka akuphatikizapo SiCI2, SiCI3, ndi zina zotero; mamolekyu ang'onoang'ono ochokera ku carbon source ndi silicon source awa adzanyamulidwa kupita pamwamba pa graphite substrate ndi mpweya wonyamula ndi mpweya wosungunuka, kenako mamolekyu ang'onoang'ono awa adzanyamulidwa pamwamba pa substrate mu mawonekedwe a adsorption, kenako zochita za mankhwala zidzachitika pakati pa mamolekyu ang'onoang'ono kuti apange madontho ang'onoang'ono omwe amakula pang'onopang'ono, ndipo madonthowo adzagwirizananso, ndipo zomwe zimachitikazo zidzaphatikizidwa ndi kupangidwa kwa zinthu zapakati (HCl gas); Kutentha kukakwera kufika pa 1000 ℃, kuchuluka kwa utoto wa SiC kumawonjezeka kwambiri. Zikuoneka kuti utoto wambiri umapangidwa ndi tinthu ta SiC (pafupifupi 4μm kukula), koma palinso zolakwika zina za SiC, zomwe zikusonyeza kuti SiC ikadali kukula molunjika kutenthaku, ndipo utotowo suli wokhuthala mokwanira. Kutentha kukakwera kufika pa 1100 ℃, zimawoneka kuti utoto wa SiC ndi wokhuthala kwambiri, ndipo zolakwika za SiC zatha kwathunthu. Chophimbacho chimapangidwa ndi tinthu ta SiC tooneka ngati madontho okhala ndi mainchesi pafupifupi 5 ~ 10μm, omwe amagwirizanitsidwa bwino. Pamwamba pa tinthu tating'onoting'ono ndi wovuta kwambiri. Umapangidwa ndi tinthu ta SiC tosawerengeka. Ndipotu, njira yokulira ya CVD-SiC pa 1100 ℃ yakhala ikulamulidwa ndi kusamutsa kwamphamvu. Mamolekyu ang'onoang'ono omwe amamatiridwa pamwamba pa substrate ali ndi mphamvu zokwanira komanso nthawi yokwanira kuti atuluke ndikukula kukhala tinthu ta SiC. Tinthu ta SiC timapanga madontho akuluakulu mofanana. Pansi pa mphamvu ya pamwamba, madontho ambiri amaoneka ngati ozungulira, ndipo madonthowo amagwirizanitsidwa mwamphamvu kuti apange chophimba cholimba cha SiC. Kutentha kukakwera kufika pa 1200℃, chophimba cha SiC chimakhala chokhuthala, koma mawonekedwe a SiC amakhala ndi mizere yambiri ndipo pamwamba pa chophimbacho pamawoneka ngati paukali. Kutentha kukakwera kufika pa 1300℃, tinthu tambiri tating'onoting'ono tomwe timakhala ndi mainchesi pafupifupi 3μm timapezeka pamwamba pa graphite substrate. Izi zili choncho chifukwa kutenthaku, SiC yasinthidwa kukhala mpweya wa gasi, ndipo kuchuluka kwa MTS decomposition rate kumakhala kofulumira kwambiri. Mamolekyu ang'onoang'ono achitapo kanthu ndikupanga tinthu ta SiC tisanayambe kulowetsedwa pamwamba pa substrate. Tinthu tating'onoting'ono titapanga tinthu tating'onoting'ono, timagwa pansi, zomwe zimapangitsa kuti tinthu ta SiC tisakhale ndi kachulukidwe koipa. Mwachionekere, 1300℃ singagwiritsidwe ntchito ngati kutentha kopangira chophimba cha SiC chokhuthala. Kuyerekeza kwathunthu kukuwonetsa kuti ngati chophimba cha SiC chokhuthala chikukonzekera, kutentha kwabwino kwambiri kwa CVD deposition ndi 1100℃.
Chithunzi 3 chikuwonetsa kuchuluka kwa zophimba za CVD SiC pa kutentha kosiyanasiyana. Pamene kutentha kwa zophimba kukukwera, kuchuluka kwa zophimba za SiC kumachepa pang'onopang'ono. Kuchuluka kwa zophimba pa 900°C ndi 0.352 mg·h-1/mm2, ndipo kukula kwa ulusi molunjika kumabweretsa kuchuluka kwa zophimba mwachangu kwambiri. Kuchuluka kwa zophimba zomwe zili ndi kuchuluka kwakukulu ndi 0.179 mg·h-1/mm2. Chifukwa cha kuyika kwa tinthu tina ta SiC, kuchuluka kwa zophimba pa 1300°C ndikotsika kwambiri, ndi 0.027 mg·h-1/mm2 yokha. Pomaliza: Kutentha kwabwino kwambiri kwa CVD deposition ndi 1100℃. Kutentha kochepa kumalimbikitsa kukula kwa SiC molunjika, pomwe kutentha kwakukulu kumapangitsa SiC kupanga nthunzi ndikupangitsa kuti ikhale yochepa. Ndi kuwonjezeka kwa kutentha kwa deposition, kuchuluka kwa deposition kumawonjezeka.Chophimba cha CVD SiCpang'onopang'ono imachepa.
Nthawi yotumizira: Meyi-26-2025