KASHI/1
Crucible, mariƙin iri da zoben jagora a cikin SiC da AIN makera kristal guda ɗaya an girma ta hanyar PVT
Kamar yadda aka nuna a cikin Hoto 2 [1], lokacin da ake amfani da hanyar safarar tururi ta jiki (PVT) don shirya SiC, kristal iri yana cikin yankin ƙananan zafin jiki, albarkatun SiC yana cikin yankin yanayin zafi sosai (sama da 2400).℃), kuma albarkatun kasa suna rubewa don samar da SiXCy (wanda ya hada da Si, SiC₂, Si₂C, da sauransu). Ana jigilar kayan aikin tururi daga yankin zafin jiki mai girma zuwa kristal iri a cikin ƙananan zafin jiki, forming iri nuclei, girma, da samar da lu'ulu'u guda ɗaya. Abubuwan filin thermal da aka yi amfani da su a cikin wannan tsari, kamar crucible, zoben jagorar kwarara, mai riƙe da kristal iri, yakamata ya kasance mai juriya ga zafin jiki kuma ba zai gurɓata albarkatun SiC da lu'ulu'u ɗaya na SiC ba. Hakazalika, abubuwan dumama a cikin ci gaban AlN guda lu'ulu'u suna buƙatar zama masu juriya ga Al tururi, N₂lalata, kuma yana buƙatar samun babban zafin jiki na eutectic (tare da AlN) don rage lokacin shirye-shiryen crystal.
An gano cewa SiC[2-5] da AlN[2-3] sun shirya taTaC mai rufigraphite thermal filin kayan sun kasance mafi tsabta, kusan babu carbon (oxygen, nitrogen) da sauran ƙazantar, ƙarancin lahani, ƙaramin juriya a cikin kowane yanki, da ƙarancin micropore da ƙarancin ramin etching sun ragu sosai (bayan KOH etching), da ingancin crystal. an inganta sosai. Bugu da kari,TaC abun cikiasarar nauyi kusan kusan sifili, bayyanar ba ta da lalacewa, ana iya sake yin fa'ida (rayuwa har zuwa 200h), na iya haɓaka dorewa da ingantaccen irin wannan shiri na crystal.
FIG. 2. (a) Zane-zane na SiC single crystal ingot girma na'urar ta hanyar PVT
(b) SamaTaC mai rufiBakin iri (ciki har da iri na SiC)
(c)Zoben jagorar graphite mai rufin TAC
KASHI/2
MOCVD GaN epitaxial Layer girma hita
Kamar yadda aka nuna a cikin Hoto na 3 (a), MOCVD GaN ci gaban fasaha ne na haɓakar tururi na sinadari ta amfani da yanayin bazuwar kwayoyin halitta don girma fina-finai na bakin ciki ta haɓakar tururin epitaxial. Daidaiton zafin jiki da daidaituwa a cikin rami ya sa mai zafi ya zama mafi mahimmancin kayan aikin MOCVD. Ko da substrate za a iya mai tsanani da sauri da kuma uniformly na dogon lokaci (a karkashin maimaita sanyaya), da kwanciyar hankali a high zafin jiki (juriya ga iskar gas) da kuma tsarki na fim zai shafi kai tsaye ingancin fim din, da kauri daidaito. da kuma aikin guntu.
Domin inganta aiki da sake amfani da na'urar dumama a cikin tsarin girma na MOCVD GaN,TAC mai rufiAn yi nasarar gabatar da hita graphite. Idan aka kwatanta da GaN epitaxial Layer girma ta hanyar dumama na al'ada (ta amfani da shafi na pBN), GaN epitaxial Layer da TaC hita ya girma yana da kusan tsarin kristal iri ɗaya, daidaiton kauri, lahani na ciki, ƙazanta doping da gurɓatawa. Bugu da kari, daTaC shafiyana da ƙarancin juriya da ƙarancin iska mai ƙarfi, wanda zai iya haɓaka inganci da daidaituwar naúrar, ta haka rage yawan amfani da wutar lantarki da asarar zafi. Za a iya daidaita porosity na rufi ta hanyar sarrafa sigogin tsari don ƙara haɓaka halayen radiation na hita da kuma tsawaita rayuwar sabis [5]. Wadannan abũbuwan amfãni saTaC mai rufigraphite heaters kyakkyawan zaɓi don tsarin haɓaka MOCVD GaN.
FIG. 3. (a) Tsarin tsari na na'urar MOCVD don haɓakar GaN epitaxial
(b) Molded TAC mai rufi graphite hita shigar a cikin saitin MOCVD, ban da tushe da sashi (hoton da ke nuna tushe da sashi a dumama)
(c) TAC mai rufaffiyar ginshiƙi mai ɗorewa bayan 17 GaN girma epitaxial. [6]
KASHI/3
Mai rufaffiyar susceptor don epitaxy (mai ɗaukar wafer)
Mai ɗaukar wafer wani muhimmin sashi ne na tsari don shirye-shiryen SiC, AlN, GaN da sauran wafers semiconductor aji na uku da haɓakar wafer epitaxial. Yawancin masu ɗaukar wafer an yi su ne da graphite kuma an lulluɓe su da murfin SiC don tsayayya da lalata daga iskar gas, tare da kewayon zazzabi na epitaxial na 1100 zuwa 1600.°C, kuma juriya na lalatawar murfin kariya yana taka muhimmiyar rawa a rayuwar mai ɗaukar wafer. Sakamakon ya nuna cewa yawan lalata na TaC yana da sau 6 a hankali fiye da SiC a cikin ammoniya mai zafi. A cikin babban zafin jiki na hydrogen, adadin lalata ya fi sau 10 a hankali fiye da SiC.
An tabbatar da gwaje-gwajen cewa trays ɗin da aka rufe da TaC suna nuna dacewa mai kyau a cikin tsarin GaN MOCVD mai shuɗi kuma baya gabatar da ƙazanta. Bayan ƙayyadaddun gyare-gyare na tsari, ledojin da aka girma ta amfani da masu ɗaukar TaC suna nuna aiki iri ɗaya da daidaito kamar masu ɗaukar SiC na al'ada. Sabili da haka, rayuwar sabis na pallets masu rufi na TAC ya fi na tawada dutse mara kyau daSiC mai rufigraphite pallets.
Lokacin aikawa: Maris-05-2024