Menene CVD SiC Coating?
Kemikal tururin ajiya (CVD) tsari ne na tsugunar da iska da ake amfani da shi don samar da ingantaccen kayan aiki masu tsafta. Ana amfani da wannan tsari sau da yawa a filin masana'anta na semiconductor don samar da fina-finai na bakin ciki a saman wafers. A cikin aiwatar da shirya silicon carbide ta CVD, da substrate yana fallasa zuwa daya ko fiye maras tabbas precursors, wanda amsa chemically a saman da substrate don saka da ake so silicon carbide adibas. Daga cikin hanyoyi da yawa don shirya kayan siliki na siliki, samfuran da aka shirya ta hanyar isar da tururi na sinadarai suna da daidaito da tsabta, kuma wannan hanyar tana da ƙarfin sarrafa tsari. CVD silicon carbide kayan suna da keɓaɓɓen haɗuwa na ingantaccen thermal, lantarki da sinadarai, yana sa su dace sosai don amfani a cikin masana'antar semiconductor inda ake buƙatar kayan aiki mai girma. CVD silicon carbide aka gyara ana amfani da ko'ina a etching kayan aiki, MOCVD kayan aiki, Si epitaxial kayan aiki da SiC epitaxial kayan aiki, m thermal sarrafa kayan aiki da sauran filayen.
Wannan labarin yana mayar da hankali kan nazarin ingancin fina-finai na bakin ciki da aka girma a yanayin zafi daban-daban yayin shirye-shiryenCVD SiC shafi, don zaɓar mafi dacewa tsarin zafin jiki. Gwajin yana amfani da graphite a matsayin substrate da trichloromethylsilane (MTS) azaman tushen iskar gas. Ana ajiye murfin SiC ta hanyar CVD mai ƙarancin matsa lamba, da micromorphology naCVD SiC shafiAna lura da shi ta hanyar duban sinadari na lantarki don tantance girman tsarin sa.
Saboda yanayin zafi na graphite substrate yana da girma sosai, matsakaicin iskar gas ɗin zai zama desorbed kuma a fitar da shi daga saman ƙasa, kuma a ƙarshe C da Si waɗanda suka rage a saman ƙasa za su samar da lokaci mai ƙarfi na SiC don samar da suturar SiC. Bisa ga tsarin ci gaban CVD-SiC da ke sama, ana iya ganin cewa zafin jiki zai shafi yaduwar iskar gas, lalatawar MTS, samuwar droplets da desorption da fitarwa na tsaka-tsakin gas, don haka yawan zafin jiki na ajiya zai taka muhimmiyar rawa a cikin ilimin halittar jiki na SiC shafi. Ƙwararren ƙwayar ƙwayar cuta na sutura shine mafi mahimmancin bayyanar da yawa na sutura. Sabili da haka, ya zama dole don nazarin tasirin yanayin yanayin ajiya daban-daban akan ƙananan ƙwayoyin cuta na CVD SiC shafi. Tun da MTS iya bazuwa da kuma ajiya SiC shafi tsakanin 900 ~ 1600 ℃, wannan gwaji zabi biyar deposition yanayin zafi na 900 ℃, 1000 ℃, 1100 ℃, 1200 ℃ da 1300 ℃ domin shirye-shiryen na SiC shafi don nazarin sakamakon zafin jiki a kan CVD-Si. Ana nuna takamaiman sigogi a cikin Teburin 3. Hoto na 2 yana nuna ƙananan ƙwayoyin cuta na CVD-SiC shafi wanda aka girma a yanayin zafi daban-daban.
Lokacin da yawan zafin jiki ya kai 900 ℃, duk SiC yana girma zuwa sifofin fiber. Ana iya ganin cewa diamita na fiber guda yana da kusan 3.5μm, kuma yanayin sa yana kusan 3 (<10). Bugu da ƙari, ya ƙunshi barbashi na nano-SiC marasa ƙima, don haka yana cikin tsarin SiC na polycrystalline, wanda ya bambanta da na SiC nanowires na al'ada da whiskers SiC-crystal guda ɗaya. Wannan SiC fibrous lahani ne na tsari wanda ya haifar da sigogin tsari marasa ma'ana. Ana iya ganin cewa tsarin wannan suturar SiC yana da ƙarancin sako-sako, kuma akwai adadi mai yawa na pores tsakanin SiC mai fibrous, kuma yawancin ya ragu sosai. Sabili da haka, wannan zafin jiki bai dace da shirye-shiryen suturar SiC mai yawa ba. Yawancin lokaci, lahani na SiC na fibrous yana haifar da ƙarancin zafin jiki da yawa. A ƙananan zafin jiki, ƙananan ƙwayoyin da aka tallata a saman ƙasa suna da ƙarancin ƙarfi da ƙarancin ƙaura. Saboda haka, ƙananan ƙwayoyin cuta suna yin ƙaura kuma suna girma zuwa mafi ƙasƙanci mafi ƙarancin makamashi na hatsin SiC (kamar tip na hatsi). Ci gaba da haɓakar jagora a ƙarshe yana haifar da lahani na SiC fibrous.
Shiri na CVD SiC Coating:
Na farko, da graphite substrate aka sanya a cikin wani high-zazzabi injin tanderu da kuma kiyaye a 1500 ℃ for 1h a cikin wani yanayi Ar domin ash kau. Sa'an nan kuma graphite block an yanke a cikin wani toshe na 15x15x5mm, da kuma surface na graphite block aka goge da 1200-raga sandpaper don kawar da surface pores da shafi jijjiga na SiC. Ana wanke shingen graphite da aka kula da shi da ethanol mai anhydrous da ruwa mai narkewa, sannan a sanya shi a cikin tanda a 100 ℃ don bushewa. A ƙarshe, ana sanya maɓallin graphite a cikin babban yankin zafin jiki na tubular tanderun don ƙaddamar da SiC. An nuna zane-zane na tsarin tattara tururin sinadarai a cikin hoto 1.
TheCVD SiC shafiAn lura da shi ta hanyar duba microscope na lantarki don tantance girman barbashi da yawa. Bugu da ƙari, an ƙididdige adadin kuɗin da aka saka na rufin SiC bisa ga dabarar da ke ƙasa: VSiC=(m2-m1)/(Sxt) x100% VSiC=Yawan ajiya; m2-mafi yawan samfurin shafi (mg); m1 - yawan adadin substrate (mg); S-surface yanki na substrate (mm2); t-lokacin ajiya (h). CVD-SiC yana da ɗan rikitarwa, kuma ana iya taƙaita tsarin kamar haka: a babban zafin jiki, MTS za ta sha bazuwar thermal don samar da tushen carbon da ƙananan ƙwayoyin siliki. Ƙananan ƙananan ƙwayoyin carbon sun haɗa da CH3, C2H2 da C2H4, da ƙananan ƙananan ƙwayoyin siliki sun hada da SiCI2, SiCI3, da dai sauransu; Wadannan tushen carbon da tushen silicone ƙananan kwayoyin halitta za a kwashe su zuwa saman graphite substrate ta hanyar iskar gas da kuma diluent gas, sa'an nan kuma wadannan kananan kwayoyin za a adsorbed a saman da substrate a cikin nau'i na adsorption, sa'an nan sinadaran halayen zai faru tsakanin kananan kwayoyin don samar da kananan droplets da sannu-sannu girma, da diluent kafofin watsa labarai za su kasance tare da juna ta hanyar dauki. samfurori (HCl gas); Lokacin da yawan zafin jiki ya tashi zuwa 1000 ℃, yawan abin rufewar SiC yana inganta sosai. Ana iya ganin cewa yawancin murfin yana kunshe da hatsin SiC (kimanin 4μm a girman), amma ana samun wasu lahani na SiC na fibrous, wanda ya nuna cewa har yanzu akwai ci gaban jagorancin SiC a wannan zafin jiki, kuma har yanzu rufin bai yi yawa ba. Lokacin da zafin jiki ya tashi zuwa 1100 ℃, ana iya ganin cewa rufin SiC yana da yawa sosai, kuma lahani na SiC na fibrous ya ɓace gaba ɗaya. Rufin yana kunshe da barbashi na SiC-dimbin diamita tare da diamita na kusan 5 ~ 10μm, waɗanda aka haɗa su tam. Fuskar barbashi yana da muguwar gaske. Ya ƙunshi hatsin SiC masu girman nano marasa adadi. A gaskiya ma, tsarin ci gaban CVD-SiC a 1100 ℃ ya zama mai sarrafa yawan jama'a. Ƙananan ƙwayoyin ƙwayoyin da aka tallata a saman ƙasan suna da isasshen kuzari da lokaci don haɓakawa da girma cikin hatsin SiC. Hatsin SiC daidai gwargwado suna samar da manyan digo. Ƙarƙashin aikin makamashi na saman, yawancin ɗigon ruwa suna bayyana mai siffar zobe, kuma ɗigon ruwa yana haɗuwa sosai don samar da murfin SiC mai yawa. Lokacin da zafin jiki ya tashi zuwa 1200 ℃, SiC shafi kuma yana da yawa, amma SiC ilimin halittar jiki ya zama mai yawa-ridged kuma saman rufin ya bayyana ya fi tsayi. Lokacin da zafin jiki ya ƙaru zuwa 1300 ℃, ana samun adadi mai yawa na nau'in nau'in nau'in nau'i na yau da kullum tare da diamita na kimanin 3μm akan farfajiyar graphite substrate. Wannan shi ne saboda a wannan zafin jiki, SiC an canza shi zuwa gazal lokaci nucleation, da kuma MTS lalata kudi ne da sauri. Kananan kwayoyin halitta sun yi martani kuma sun tarwatsa su don samar da hatsin SiC kafin a sanya su a saman saman. Bayan hatsin suna samar da barbashi mai zaki, za su faɗi a ƙasa, ƙarshe sun haifar da sako-sako da siic barbashi mai sauƙi tare da talauci mara kyau. Babu shakka, 1300 ℃ ba za a iya amfani da matsayin forming zafin jiki na m SiC shafi. Cikakken kwatancen yana nuna cewa idan za'a shirya suturar SiC mai yawa, mafi kyawun yanayin ajiyar CVD shine 1100 ℃.
Hoto na 3 yana nuna adadin jigon suturar CVD SiC a yanayin zafi daban-daban. Yayin da yawan zafin jiki ya ƙaru, ƙimar da aka samu na murfin SiC yana raguwa a hankali. Matsakaicin adadin kuɗi a 900 ° C shine 0.352 mg · h-1/mm2, kuma haɓakar jagorar filaye yana kaiwa ga mafi girman adadin ajiya. Matsakaicin ƙaddamarwa na sutura tare da mafi girma shine 0.179 mg · h-1 / mm2. Saboda ƙaddamar da wasu ɓangarori na SiC, ƙimar ajiya a 1300°C shine mafi ƙanƙanta, kawai 0.027 mg·h-1/mm2. Kammalawa: Mafi kyawun zafin jiki na CVD shine 1100 ℃. Ƙananan zafin jiki yana haɓaka haɓakar jagorar SiC, yayin da yawan zafin jiki yana haifar da SiC don samar da jigon tururi kuma yana haifar da ƙaranci. Tare da karuwar yawan zafin jiki, yawan adadin kuɗi naCVD SiC shafisannu a hankali yana raguwa.
Lokacin aikawa: Mayu-26-2025