Oxidized hatsi a tsaye da fasahar haɓaka epitaxial-Ⅱ

2. Epitaxial bakin ciki fim girma

Substrate ɗin yana ba da Layer goyon bayan jiki ko madaurin kai don na'urorin wutar lantarki na Ga2O3. Muhimmin Layer na gaba shine layin tashar tashar ko Layer epitaxial da ake amfani da shi don juriya da jigilar jigilar kaya. Domin ƙara rushewar wutar lantarki da rage juriya na sarrafawa, kauri mai iya sarrafawa da tattara abubuwan ƙara kuzari, da ingancin kayan abu mafi kyau, wasu abubuwan buƙatu ne. High quality Ga2O3 epitaxial yadudduka yawanci ana ajiye ta amfani da kwayoyin katako epitaxy (MBE), karfe Organic tururin tururi (MOCVD), halide tururi jijiya (HVPE), pulsed Laser jijiya (PLD), da hazo CVD tushen dabaru dabaru.

Tebur 2 Wasu fasaha na epitaxial wakilci

2.1 MBE Hanyar

Fasahar MBE ta shahara saboda iyawarta na haɓaka ingantacciyar inganci, fina-finai β-Ga2O3 mara lahani tare da nau'in n-nau'in doping mai iya sarrafa shi saboda matsanancin yanayin injin da yake da shi da kuma tsaftar kayan abu. Sakamakon haka, ya zama ɗaya daga cikin mafi yawan nazari da kuma yuwuwar kasuwanci da fasahar β-Ga2O3 na bakin ciki na fim. Bugu da ƙari, hanyar MBE kuma ta yi nasarar shirya babban inganci, ƙananan doped heterostructure β- (AlXGa1-X) 2O3 / Ga2O3 bakin ciki fim Layer. MBE na iya saka idanu akan tsari da ilimin halittar jiki a cikin ainihin lokaci tare da daidaitaccen Layer na atomic ta amfani da tsinkayyar babban ƙarfin lantarki (RHEED). Duk da haka, fina-finan β-Ga2O3 da suka girma ta amfani da fasahar MBE har yanzu suna fuskantar kalubale da yawa, kamar ƙananan girma da ƙananan girman fim. Binciken ya gano cewa girman girman ya kasance a cikin tsari na (010)> (001)> (-201)> (100). A ƙarƙashin ɗan ƙaramin Ga-arziƙi na 650 zuwa 750 ° C, β-Ga2O3 (010) yana nuna haɓaka mafi kyau tare da santsi mai santsi da ƙimar girma mai girma. Yin amfani da wannan hanyar, β-Ga2O3 epitaxy an samu nasarar samun nasara tare da ƙarancin RMS na 0.1 nm. β-Ga2O3 A cikin yanayin Ga-arziki, ana nuna fina-finai na MBE da aka girma a yanayin zafi daban-daban a cikin adadi. Novel Crystal Technology Inc. ya sami nasarar samar da wafers 10 × 15mm2 β-Ga2O3MBE a cikin epitaxially. Suna ba da babban inganci (010) daidaitacce β-Ga2O3 guda ɗaya na kristal tare da kauri na 500 μm da XRD FWHM ƙasa da 150 arc seconds. Substrate shine Sn doped ko Fe doped. Sn-doped conductive Substrate yana da matakan doping na 1E18 zuwa 9E18cm−3, yayin da ƙarfe-doped Semi-insulating substrate yana da juriya sama da 10E10 Ω cm.

2.2 Hanyar MOCVD

MOCVD yana amfani da mahaɗan ƙwayoyin ƙarfe na ƙarfe azaman kayan gabaɗaya don haɓaka fina-finai na bakin ciki, ta yadda ake samun manyan samarwa na kasuwanci. Lokacin girma Ga2O3 ta amfani da hanyar MOCVD, ana amfani da trimethylgallium (TMGa), triethylgallium (TEGa) da Ga (dipentyl glycol formate) azaman tushen Ga, yayin da H2O, O2 ko N2O ana amfani dashi azaman tushen oxygen. Girma ta amfani da wannan hanya gabaɗaya yana buƙatar yanayin zafi (>800°C). Wannan fasaha tana da yuwuwar cimma ƙarancin maida hankali mai ɗaukar nauyi da haɓakar zafin jiki mai ƙarfi da ƙarancin zafin jiki, don haka yana da matukar mahimmanci ga fahimtar manyan na'urorin wutar lantarki na β-Ga2O3. Idan aka kwatanta da hanyar girma na MBE, MOCVD yana da damar samun ci gaba mai girma na fina-finai na β-Ga2O3 saboda halayen haɓakar zafin jiki da kuma halayen sinadaran.

Hoto 7 β-Ga2O3 (010) Hoton AFM

Hoto 8 β-Ga2O3 Dangantakar da ke tsakanin μand juriyar takardar da aka auna ta Hall da zafin jiki

2.3 Hanyar HVPE

HVPE babban fasaha ne na epitaxial kuma an yi amfani dashi sosai a cikin ci gaban epitaxial na III-V fili semiconductor. HVPE an san shi don ƙarancin samarwa, ƙimar girma mai sauri, da babban kauri na fim. Ya kamata a lura da cewa HVPEβ-Ga2O3 yawanci yana nuna m surface ilimin halittar jiki da kuma babban yawa na surface lahani da rami. Don haka, ana buƙatar matakan gogewa na sinadarai da injina kafin kera na'urar. Fasahar HVPE don β-Ga2O3 epitaxy yawanci yana amfani da GaCl da O2 gaseous a matsayin mafari don haɓaka yanayin zafin jiki na (001) β-Ga2O3 matrix. Hoto na 9 yana nuna yanayin yanayi da girman girma na fim din epitaxial a matsayin yanayin zafi. A cikin 'yan shekarun nan, Novel Crystal Technology Inc. na Japan ya sami gagarumar nasarar kasuwanci a cikin HVPE homoepitaxial β-Ga2O3, tare da kaurin Layer na epitaxial na 5 zuwa 10 μm da girman wafer na 2 da 4 inci. Bugu da kari, 20 μm kauri HVPE β-Ga2O3 homoepitaxial wafers wanda China Electronics Technology Group Corporation ya samar su ma sun shiga matakin kasuwanci.

Hoto 9 Hanyar HVPE β-Ga2O3

2.4 Hanyar PLD

Ana amfani da fasahar PLD galibi don saka hadaddun fina-finai na oxide da tsarin yanayin halitta. A yayin aiwatar da haɓakar PLD, makamashin photon yana haɗe da abin da aka yi niyya ta hanyar fitar da lantarki. Ya bambanta da MBE, PLD tushen barbashi an kafa ta Laser radiation tare da musamman high makamashi (> 100 eV) kuma daga baya ajiye a kan wani mai tsanani substrate. Duk da haka, a lokacin aikin zubar da ciki, wasu nau'o'in makamashi masu karfi za su yi tasiri kai tsaye a kan kayan abu, haifar da lahani kuma don haka rage ingancin fim din. Hakazalika da hanyar MBE, RHEED za a iya amfani da shi don saka idanu da tsarin tsarin da kayan aiki na kayan aiki a cikin ainihin lokaci yayin tsarin ƙaddamarwa na PLD β-Ga2O3, ƙyale masu bincike su sami cikakkun bayanai na girma. Ana sa ran hanyar PLD za ta haɓaka fina-finan β-Ga2O3 masu ɗaukar nauyi sosai, yana mai da ita ingantaccen hanyar sadarwar ohmic a cikin na'urorin wutar lantarki na Ga2O3.

Hoto 10 Hoton AFM na Si doped Ga2O3

2.5 Hanyar MIST-CVD

MIST-CVD fasaha ce mai sauƙi kuma mai araha mai araha. Wannan hanyar CVD ta ƙunshi martanin fesa abin da aka ƙirƙira a kan wani abu don cimma jigon fim na bakin ciki. Koyaya, ya zuwa yanzu, Ga2O3 girma ta amfani da hazo CVD har yanzu ba shi da kyawawan kaddarorin lantarki, wanda ya bar ɗaki mai yawa don haɓakawa da haɓakawa a nan gaba.