Fasahar girma ta hatsi mai oxidized da epitaxial-Ⅱ

2. Girman fim ɗin siriri na Epitaxial

Tsarin yana samar da wani Layer na tallafi na zahiri ko Layer mai sarrafawa ga na'urorin wutar lantarki na Ga2O3. Babban Layer na gaba shine Layer na tashar ko Layer na epitaxial da ake amfani da shi don juriya ga ƙarfin lantarki da jigilar kaya. Domin ƙara ƙarfin lantarki mai lalacewa da rage juriya ga watsawa, kauri mai sarrafawa da yawan amfani da doping, da kuma ingantaccen ingancin abu, wasu abubuwan da ake buƙata ne. Yawancin lokaci ana ajiye manyan Layer na epitaxial na Ga2O3 ta amfani da molecular beam epitaxy (MBE), metal organic chemical tururi deposition (MOCVD), halide tururi deposition (HVPE), pulsed laser deposition (PLD), da dabarun adana CVD bisa ga hazo.

Tebur na 2 Wasu fasahohin epitaxial masu wakiltar

2.1 Hanyar MBE

Fasahar MBE ta shahara saboda iyawarta na haɓaka fina-finan β-Ga2O3 masu inganci, marasa lahani tare da maganin n-type mai sarrafawa saboda yanayinta mai matuƙar tsabta da kuma tsaftar kayan aiki. Sakamakon haka, ta zama ɗaya daga cikin fasahohin adana fim na β-Ga2O3 da aka fi nazari a kansu kuma waɗanda ake iya tallatawa. Bugu da ƙari, hanyar MBE ta kuma shirya wani babban tsari mai laushi mai laushi mai ƙarancin allurar β-(AlXGa1-X)2O3/Ga2O3. MBE na iya sa ido kan tsarin saman da yanayinsa a ainihin lokaci tare da daidaiton Layer na atomic ta amfani da hasken wutar lantarki mai ƙarfi (RHEED). Duk da haka, fina-finan β-Ga2O3 da aka noma ta amfani da fasahar MBE har yanzu suna fuskantar ƙalubale da yawa, kamar ƙarancin ƙimar girma da ƙaramin girman fim. Binciken ya gano cewa ƙimar girma tana cikin tsari na (010)>(001)>(−201)>(100). A ƙarƙashin yanayin Ga-rich mai ɗan yawa na 650 zuwa 750°C, β-Ga2O3 (010) yana nuna ci gaba mafi kyau tare da santsi a saman da kuma babban saurin girma. Ta amfani da wannan hanyar, an sami nasarar cimma epitaxy β-Ga2O3 tare da kauri na RMS na 0.1 nm. β-Ga2O3. A cikin yanayin Ga-rich, an nuna fina-finan MBE da aka noma a yanayin zafi daban-daban a cikin hoton. Novel Crystal Technology Inc. ta sami nasarar samar da wafers β-Ga2O3MBE guda 10 × 15mm2 cikin nasara. Suna samar da manyan abubuwan lu'ulu'u guda ɗaya masu inganci (010) waɗanda aka daidaita da β-Ga2O3 tare da kauri na 500 μm da XRD FWHM ƙasa da daƙiƙa 150 na baka. An yi amfani da substrate ɗin Sn doped ko Fe doped. Tsarin sarrafa sinadarai na Sn-doped yana da yawan sinadarin doping tsakanin 1E18 zuwa 9E18cm−3, yayin da tsarin sinadarin semi-insulating na ƙarfe yana da juriya fiye da 10E10 Ω cm.

2.2 Hanyar MOCVD

MOCVD yana amfani da sinadarai na ƙarfe a matsayin kayan da suka fara samar da sirara don samar da fina-finai masu sirara, ta haka ne ake samun manyan kayayyakin kasuwanci. Lokacin da ake noma Ga2O3 ta amfani da hanyar MOCVD, yawanci ana amfani da trimethylgallium (TMGa), triethylgallium (TEGa) da Ga (dipentyl glycol formate) a matsayin tushen Ga, yayin da ake amfani da H2O, O2 ko N2O a matsayin tushen iskar oxygen. Girma ta amfani da wannan hanyar gabaɗaya yana buƙatar yanayin zafi mai yawa (>800°C). Wannan fasaha tana da damar cimma ƙarancin yawan mai ɗaukar kaya da kuma motsi na lantarki mai zafi da ƙasa, don haka yana da matuƙar muhimmanci ga cimma na'urorin wutar lantarki masu aiki sosai na β-Ga2O3. Idan aka kwatanta da hanyar girma ta MBE, MOCVD tana da fa'idar cimma babban ƙimar girma na fina-finan β-Ga2O3 saboda halayen girma mai zafi da halayen sinadarai.

Hoto 7 β-Ga2O3 (010) Hoton AFM

Hoto na 8 β-Ga2O3 Alaƙar da ke tsakanin juriyar μ da takardar da aka auna ta hanyar Hall da zafin jiki

2.3 Hanyar HVPE

HVPE fasaha ce ta epitaxial mai girma kuma an yi amfani da ita sosai wajen haɓaka epitaxial na semiconductors masu haɗin III-V. An san HVPE saboda ƙarancin farashin samarwa, saurin girma, da kauri mai yawa na fim. Ya kamata a lura cewa HVPEβ-Ga2O3 yawanci yana nuna yanayin saman da ke da rauni da kuma yawan lahani na saman da ramuka. Saboda haka, ana buƙatar hanyoyin goge sinadarai da na injiniya kafin ƙera na'urar. Fasahar HVPE don epitaxy β-Ga2O3 yawanci tana amfani da GaCl da O2 na iskar gas a matsayin abubuwan da suka riga suka haɓaka amsawar zafin jiki mai yawa na matrix β-Ga2O3 (001). Hoto na 9 yana nuna yanayin saman da ƙimar girma na fim ɗin epitaxial a matsayin aikin zafin jiki. A cikin 'yan shekarun nan, Novel Crystal Technology Inc. na Japan ya sami babban nasara a kasuwanci a cikin HVPE homoepitaxial β-Ga2O3, tare da kauri na Layer na epitaxial na 5 zuwa 10 μm da girman wafer na inci 2 da 4. Bugu da ƙari, wafers ɗin homoepitaxial na HVPE β-Ga2O3 mai kauri μm 20 da China Electronics Technology Group Corporation ta samar suma sun shiga matakin kasuwanci.

Hoto na 9 Hanyar HVPE β-Ga2O3

2.4 Hanyar PLD

Ana amfani da fasahar PLD galibi don saka fina-finan oxide masu rikitarwa da kuma tsarin heterostructures. A lokacin tsarin girma na PLD, ana haɗa kuzarin photon da kayan da aka nufa ta hanyar tsarin fitar da wutar lantarki. Sabanin MBE, ana samar da barbashi na tushen PLD ta hanyar hasken laser tare da makamashi mai yawa (>100 eV) sannan a ajiye su a kan wani abu mai zafi. Duk da haka, a lokacin tsarin cirewa, wasu barbashi masu ƙarfi za su yi tasiri kai tsaye kan saman kayan, suna haifar da lahani a maki kuma don haka rage ingancin fim ɗin. Kamar hanyar MBE, ana iya amfani da RHEED don sa ido kan tsarin saman da yanayin kayan a ainihin lokacin aikin ajiye PLD β-Ga2O3, wanda ke ba masu bincike damar samun bayanai daidai game da girma. Ana sa ran hanyar PLD za ta haɓaka fina-finan β-Ga2O3 masu aiki sosai, wanda hakan zai sa ta zama mafita mafi kyau ta tuntuɓar ohmic a cikin na'urorin wutar lantarki na Ga2O3.

Hoto na 10 Hoton AFM na Si mai maganin Ga2O3

Hanyar MIST-CVD ta 2.5

MIST-CVD fasaha ce mai sauƙi kuma mai araha don haɓaka fim ɗin siriri. Wannan hanyar CVD ta ƙunshi amsawar fesa wani abu mai tsari na atomized akan wani abu don cimma ajiyar fim ɗin siriri. Duk da haka, zuwa yanzu, Ga2O3 da aka noma ta amfani da mist CVD har yanzu ba shi da kyawawan kaddarorin lantarki, wanda ke barin sarari mai yawa don haɓakawa da haɓakawa a nan gaba.