Hot filament CVD shine farkon kuma mafi shaharar hanyar girma lu'u-lu'u a ƙananan matsi. 1982 Matsumoto et al. zafi filament karfe refractory zuwa sama da 2000 ° C, inda zazzabi da H2 gas wucewa ta cikin filament da sauri samar hydrogen atoms. Samar da sinadarin hydrogen a lokacin hydrocarbon pyrolysis ya kara yawan adadin fina-finan lu'u-lu'u. An zaɓi lu'u-lu'u da aka zaɓa kuma an hana ƙirƙira graphite, yana haifar da ƙimar ajiyar fim ɗin lu'u-lu'u akan tsari na mm/h, wanda shine babban adadin ajiya don hanyoyin da aka saba amfani da su a masana'antu. Ana iya yin HFCVD ta amfani da maɓuɓɓugar carbon iri-iri, kamar methane, propane, acetylene, da sauran hydrocarbons, har ma da wasu hydrocarbons masu ɗauke da iskar oxygen, irin su acetone, ethanol, da methanol. Ƙarin ƙungiyoyin da ke ɗauke da iskar oxygen yana faɗaɗa kewayon zafin jiki don ajiyar lu'u-lu'u.
Baya ga tsarin HFCVD na yau da kullun, akwai gyare-gyare da yawa ga tsarin HFCVD. Mafi na kowa shine haɗe-haɗen plasma plasma da tsarin HFCVD. A cikin wannan tsarin, ana iya amfani da wutar lantarki mai ban sha'awa ga substrate da filament. Ƙimar tabbataccen ƙiyayya ta yau da kullun akan ma'auni da kuma wani mummunan ra'ayi akan filament yana haifar da electrons don bombard da substrate, barin saman hydrogen don lalata. Sakamakon lalacewa shine karuwa a cikin adadin ajiya na fim din lu'u-lu'u (kimanin 10 mm/h), dabarar da aka sani da HFCVD mai taimakon lantarki. lokacin da ƙarfin son zuciya ya isa ya haifar da tsayayyen fitarwa na plasma, bazuwar H2 da hydrocarbons suna ƙaruwa sosai, wanda a ƙarshe yana haifar da haɓaka ƙimar girma. Lokacin da aka juya polarity na son zuciya (substrate yana da mummunan ra'ayi), ion bombardment yana faruwa a kan ma'auni, yana haifar da karuwa a cikin lu'u-lu'u a kan abubuwan da ba na lu'u-lu'u ba. Wani gyare-gyare shine maye gurbin filament mai zafi guda ɗaya tare da filaments daban-daban don cimma daidaituwa na daidaituwa kuma a ƙarshe babban yanki na fim ɗin lu'u-lu'u. Rashin hasara na HFCVD shine cewa ƙawancen thermal na filament na iya haifar da gurɓataccen abu a cikin fim ɗin lu'u-lu'u.
(2) Microwave Plasma CVD (MWCVD)
A cikin 1970s, masana kimiyya sun gano cewa za a iya ƙara yawan ƙwayar hydrogen ta atomatik ta amfani da plasma na DC. Sakamakon haka, plasma ya zama wata hanya don haɓaka ƙirƙirar fina-finai na lu'u-lu'u ta hanyar lalata H2 zuwa hydrogen atom da kunna ƙungiyoyin atomic na tushen carbon. Baya ga plasma na DC, wasu nau'ikan plasma guda biyu ma sun sami kulawa. CVD plasma na microwave yana da mitar tashin hankali na 2.45 GHZ, kuma RF plasma CVD yana da mitar motsa jiki na 13.56 MHz. Plasma na microwave na musamman ne saboda mitar microwave tana haifar da girgizar lantarki. Lokacin da electrons suka yi karo da atom ɗin gas ko kwayoyin halitta, ana haifar da yawan rabuwa. Ana kiran plasma na Microwave a matsayin kwayoyin halitta tare da "zafi" electrons, "sanyi" ions da tsaka tsaki. A lokacin jigon fina-finai na bakin ciki, microwaves suna shiga ɗakin haɗin CVD mai haɓaka plasma ta taga. Plasma mai haske gabaɗaya tana da siffar siffa, kuma girman sararin yana ƙaruwa da ikon microwave. Fina-finai na lu'u-lu'u na bakin ciki suna girma a kan wani yanki a kusurwar yankin da ke haskakawa, kuma ba dole ba ne substrate ya kasance cikin hulɗar kai tsaye tare da yankin mai haske.
–An fitar da wannan labarininjin shafa injin injinGuangdong Zhenhua
Lokacin aikawa: Juni-19-2024