Itekhnoloji yokukhula kweenkozo ezimile ezi-oxidized kunye ne-epitaxial-Ⅱ

2. Ukukhula kwefilimu encinci ye-Epitaxial

I-substrate inika umaleko wenkxaso ebonakalayo okanye umaleko oqhubayo kwizixhobo zamandla zeGa2O3. Umaleko olandelayo obalulekileyo ngumaleko wetshaneli okanye umaleko we-epitaxial osetyenziselwa ukumelana nombane kunye nokuthutha abathwali. Ukuze kwandiswe umbane oqhekekileyo kwaye kuncitshiswe ukumelana nokuqhuba, ubukhulu obulawulekayo kunye noxinzelelo lwe-doping, kunye nomgangatho ophezulu wezinto, zezinye zezinto ezifunekayo. Iileya ze-epitaxial zeGa2O3 ezikumgangatho ophezulu zihlala zifakwa kusetyenziswa i-epitaxy ye-molecular beam (MBE), i-metal organic chemical vapor deposition (MOCVD), i-halide vapor deposition (HVPE), i-pulsed laser deposition (PLD), kunye neendlela zokubeka ezisekelwe kwi-fog CVD.

Itheyibhile 2 Ezinye iiteknoloji ezimele i-epitaxial

2.1 Indlela ye-MBE

Itekhnoloji ye-MBE idume ngokukwazi kwayo ukukhulisa iifilimu ze-β-Ga2O3 ezikumgangatho ophezulu, ezingenaziphene ezine-doping yohlobo lwe-n elawulekayo ngenxa yendawo yayo yokungafumani i-vacuum ephezulu kakhulu kunye nobumsulwa bezinto ezibonakalayo. Ngenxa yoko, iye yaba yenye yezona teknoloji zokubeka ifilimu ezibhityileyo ze-β-Ga2O3 ezifundwe kakhulu kwaye ezinokuthi zithengiswe. Ukongeza, indlela ye-MBE ikwalungiselele ngempumelelo umaleko wefilimu obhityileyo we-β-(AlXGa1-X)2O3/Ga2O3 okumgangatho ophezulu, ophantsi. I-MBE inokujonga ulwakhiwo lomphezulu kunye ne-morphology ngexesha langempela ngokuchaneka komaleko we-athomu ngokusebenzisa i-reflection high energy electron diffraction (RHEED). Nangona kunjalo, iifilimu ze-β-Ga2O3 ezikhuliswe kusetyenziswa itekhnoloji ye-MBE zisajongene nemingeni emininzi, efana nesantya sokukhula esiphantsi kunye nobukhulu befilimu encinci. Olu phononongo lufumanise ukuba izinga lokukhula lalikulandelelwano lwe-(010)>(001)>(−201)>(100). Phantsi kweemeko ezityebileyo kancinci zeGa ezingama-650 ukuya kwi-750°C, i-β-Ga2O3 (010) ibonisa ukukhula okuhle kakhulu ngomphezulu ogudileyo kunye nesantya sokukhula esiphezulu. Ngokusebenzisa le ndlela, i-β-Ga2O3 epitaxy ifezekiswe ngempumelelo nge-RMS roughness ye-0.1 nm. β-Ga2O3 Kwindawo etyebileyo yeGa, iifilimu ze-MBE ezikhuliswe kumaqondo obushushu ahlukeneyo ziboniswe kumfanekiso. I-Novel Crystal Technology Inc. ivelise ngempumelelo ii-wafers ze-10 × 15mm2 β-Ga2O3MBE. Zibonelela nge-substrates ze-β-Ga2O3 ezikumgangatho ophezulu (010) ezijolise kwi-500 μm kunye ne-XRD FWHM ngaphantsi kwemizuzwana eyi-150 ye-arc. I-substrate i-Sn doped okanye i-Fe doped. I-substrate eqhubayo ene-Sn-doped ine-doping concentration ye-1E18 ukuya kwi-9E18cm−3, ngelixa i-substrate ene-iron-doped semi-insulating substrate ine-resistivity ephezulu kune-10E10 Ω cm.

2.2 Indlela ye-MOCVD

I-MOCVD isebenzisa iikhompawundi zesinyithi zendalo njengezinto zokuqala ukukhulisa iifilimu ezincinci, ngaloo ndlela ifezekisa imveliso enkulu yorhwebo. Xa kukhuliswa iGa2O3 kusetyenziswa indlela yeMOCVD, i-trimethylgallium (TMGa), i-triethylgallium (TEGa) kunye neGa (dipentyl glycol formate) zihlala zisetyenziswa njengomthombo weGa, ngelixa i-H2O, i-O2 okanye i-N2O zisetyenziswa njengomthombo weoksijini. Ukukhula kusetyenziswa le ndlela ngokubanzi kufuna amaqondo obushushu aphezulu (>800°C). Le teknoloji inamandla okufikelela kuxinzelelo oluphantsi lokuthwala kunye nokuhamba kwee-electron kubushushu obuphezulu nobuphantsi, ngoko ke ibaluleke kakhulu ekufezekisweni kwezixhobo zamandla ze-β-Ga2O3 ezisebenzayo. Xa kuthelekiswa nendlela yokukhula ye-MBE, i-MOCVD inenzuzo yokufikelela kumazinga aphezulu okukhula kweefilimu ze-β-Ga2O3 ngenxa yeempawu zokukhula kobushushu obuphezulu kunye neempendulo zeekhemikhali.

Umzobo 7 β-Ga2O3 (010) umfanekiso we-AFM

Umfanekiso 8 β-Ga2O3 Ubudlelwane phakathi kweμ kunye nokumelana kweshiti okulinganiswe yiHall kunye nobushushu

2.3 Indlela ye-HVPE

I-HVPE yitekhnoloji ye-epitaxial evuthiweyo kwaye isetyenziswa kakhulu ekukhuleni kwe-epitaxial yee-semiconductors ze-III-V compound. I-HVPE yaziwa ngexabiso layo eliphantsi lemveliso, izinga lokukhula ngokukhawuleza, kunye nobukhulu befilimu ephezulu. Kufuneka kuqatshelwe ukuba i-HVPEβ-Ga2O3 idla ngokubonisa imo yomphezulu orhabaxa kunye noxinano olukhulu lweziphene zomphezulu kunye neengxondorha. Ke ngoko, iinkqubo zokupholisha iikhemikhali kunye noomatshini ziyafuneka ngaphambi kokuba kwenziwe isixhobo. Itekhnoloji ye-HVPE ye-β-Ga2O3 epitaxy idla ngokusebenzisa i-GaCl kunye ne-O2 yegesi njengezinto zokuqala ukukhuthaza impendulo yobushushu obuphezulu be-(001) β-Ga2O3 matrix. Umfanekiso 9 ubonisa imeko yomphezulu kunye nezinga lokukhula kwefilimu ye-epitaxial njengomsebenzi wobushushu. Kwiminyaka yakutshanje, iNovel Crystal Technology Inc. yaseJapan iphumelele impumelelo enkulu kwezorhwebo kwi-HVPE homoepitaxial β-Ga2O3, enobukhulu be-epitaxial layer obuyi-5 ukuya kwi-10 μm kunye nobukhulu be-wafer obuyi-2 kunye ne-4 intshi. Ukongeza, ii-wafers ze-HVPE β-Ga2O3 homoepitaxial ezibukhulu obuyi-20 μm eziveliswe yiChina Electronics Technology Group Corporation nazo zingene kwinqanaba lokuthengisa.

Umfanekiso 9 Indlela ye-HVPE β-Ga2O3

2.4 Indlela ye-PLD

Itekhnoloji ye-PLD isetyenziswa kakhulu ukufaka iifilimu ze-oxide ezintsonkothileyo kunye nezakhiwo ze-hetero. Ngexesha lenkqubo yokukhula kwe-PLD, amandla e-photon adityaniswa nezinto ekujoliswe kuzo ngenkqubo yokukhupha i-electron. Ngokungafaniyo ne-MBE, amasuntswana omthombo we-PLD enziwa yimitha ye-laser enamandla aphezulu kakhulu (>100 eV) aze emva koko afakwe kwi-substrate eshushu. Nangona kunjalo, ngexesha lenkqubo yokukhupha, amanye amasuntswana anamandla aphezulu aya kuchaphazela ngqo umphezulu wezinto, edala iziphene zenqaku kwaye ngaloo ndlela anciphise umgangatho wefilimu. Ngokufanayo nendlela ye-MBE, i-RHEED ingasetyenziselwa ukujonga ulwakhiwo lomphezulu kunye ne-morphology yezinto ngexesha langempela ngexesha lenkqubo yokubeka i-PLD β-Ga2O3, ivumela abaphandi ukuba bafumane ngokuchanekileyo ulwazi lokukhula. Indlela ye-PLD kulindeleke ukuba ikhulise iifilimu ze-β-Ga2O3 eziqhuba kakuhle, okwenza ukuba ibe sisisombululo soqhagamshelwano lwe-ohmic esilungisiweyo kwizixhobo zamandla ze-Ga2O3.

Umfanekiso we-10 AFM umfanekiso we-Si doped Ga2O3

2.5 Indlela ye-MIST-CVD

I-MIST-CVD yindlela elula nengabizi kakhulu yokukhulisa ifilimu encinci. Le ndlela ye-CVD ibandakanya ukusabela kokutshiza i-atomized precursor kwi-substrate ukuze kufunyanwe i-thin film deposition. Nangona kunjalo, ukuza kuthi ga ngoku, i-Ga2O3 ekhuliswe kusetyenziswa i-mist CVD isenazo iimpawu zombane ezilungileyo, nto leyo eshiya indawo eninzi yokuphucula nokwenza ngcono kwixesha elizayo.