Ikoranabuhanga ryo gukura ibinyampeke bihagaze neza n'ikoranabuhanga ryo gukura mu gice cya epitaxial-Ⅱ

2. Gukura kwa epitaxial thin film

Iyi substrate itanga urwego rufatika cyangwa urwego ruyobora ibikoresho by'amashanyarazi bya Ga2O3. Urwego rukurikiraho rw'ingenzi ni urwego rw'umuyoboro cyangwa urwego rwa epitaxial rukoreshwa mu kurwanya voltage no gutwara abantu. Kugira ngo wongere voltage yo kwangirika no kugabanya imbaraga zo gutwara, ubugari bugenzurwa n'ubwinshi bw'ibikoresho, hamwe n'ubwiza bw'ibikoresho, ni bimwe mu bisabwa. Uduce twa epitaxial twa Ga2O3 twiza cyane dukunze gushyirwamo hakoreshejwe epitaxy ya molekile (MBE), deposition y'umwuka w'ibinyabutabire by'ingufu (MOCVD), deposition y'umwuka w'ingufu (HVPE), deposition ya laser ya pulsed (PLD), na tekiniki zo gushyiramo CVD zishingiye ku gihu.

Imbonerahamwe ya 2 Zimwe mu ikoranabuhanga ryihariye rya epitaxial

Uburyo bwa MBE bwa 2.1

Ikoranabuhanga rya MBE rizwiho ubushobozi bwo guteza imbere filime za β-Ga2O3 nziza kandi zidafite inenge hamwe n’uburyo bwo kugenzura bwa n-type doping bitewe n’ibidukikije byayo bitagira amashanyarazi menshi cyane ndetse n’uburyo bworoshye bwo gukoresha ibikoresho. Kubera iyo mpamvu, yabaye imwe mu ikoranabuhanga rya β-Ga2O3 thin film deposition ryakwigwa cyane kandi rishobora kugurishwa. Byongeye kandi, uburyo bwa MBE bwanateguye neza urwego rwo hejuru rwa heterostructure β-(AlXGa1-X)2O3/Ga2O3 thin film layer. MBE ishobora gukurikirana imiterere y’ubuso n’imiterere yabyo mu gihe nyacyo ikoresheje uburyo bworoshye bwo gushyira ahagaragara electron diffraction (RHEED). Ariko, filime za β-Ga2O3 zakuweho hakoreshejwe ikoranabuhanga rya MBE ziracyahura n’imbogamizi nyinshi, nko gukura guke no kuba filime ntoya. Ubushakashatsi bwagaragaje ko igipimo cyo gukura cyari hagati ya (010)>(001)>(−201)>(100). Mu gihe cy’ubushyuhe bungana na Ga bungana na 650 kugeza 750°C, β-Ga2O3 (010) igaragaza gukura neza hamwe n’ubuso bworoshye n’umuvuduko wo gukura mwinshi. Hakoreshejwe ubu buryo, β-Ga2O3 epitaxy yagezweho neza hamwe n’ubushyuhe bwa RMS bwa 0.1 nm. β-Ga2O3 Mu bidukikije bikungahaye kuri Ga, filime za MBE zahinzwe ku bushyuhe butandukanye zigaragazwa ku ishusho. Novel Crystal Technology Inc. yakoze neza epitaxially wafers 10 × 15mm2 β-Ga2O3MBE. Zitanga substrates nziza (010) za β-Ga2O3 crystal imwe ifite ubugari bwa 500 μm na XRD FWHM munsi y’amasegonda 150 arc. Substrate ni Sn doped cyangwa Fe doped. Substrate itwara umwuka ya Sn-doped ifite igipimo cya doping cya 1E18 kugeza 9E18cm−3, mu gihe substrate itwara umwuka ya semi-insulating ifite ubushobozi bwo kwirinda kurenza 10E10 Ω cm.

2.2 Uburyo bwa MOCVD

MOCVD ikoresha imvange y'ibyuma nk'ibikoresho bya mbere mu gukura filime nto, bityo igatanga umusaruro mwinshi mu bucuruzi. Mu guhinga Ga2O3 hakoreshejwe uburyo bwa MOCVD, trimethylgallium (TMGa), triethylgallium (TEGa) na Ga (dipentyl glycol formate) bikunze gukoreshwa nk'isoko ya Ga, mu gihe H2O, O2 cyangwa N2O bikoreshwa nk'isoko ya ogisijeni. Gukura hakoreshejwe ubu buryo muri rusange bisaba ubushyuhe bwinshi (>800°C). Ubu buryo bufite ubushobozi bwo kugera ku bushyuhe buke bwo gutwara no kugenda kwa electron mu bushyuhe bwinshi no munsi, bityo ni ingenzi cyane mu gushyira mu bikorwa ibikoresho by'ingufu bya β-Ga2O3 bifite imikorere myiza. Ugereranyije n'uburyo bwo gukura bwa MBE, MOCVD ifite akarusho ko kugera ku gipimo cyo gukura kinini cyane cya filime za β-Ga2O3 bitewe n'imiterere y'ikura ry'ubushyuhe bwinshi n'ibikorwa bya shimi.

Igishushanyo 7 β-Ga2O3 (010) AFM ishusho

Ishusho ya 8 β-Ga2O3 Isano iri hagati ya μ n'ubudahangarwa bw'urupapuro bipimwe hakoreshejwe Hall n'ubushyuhe

2.3 Uburyo bwa HVPE

HVPE ni ikoranabuhanga rya epitaxial rimaze igihe kinini kandi ryakoreshejwe cyane mu gukura kwa epitaxial kwa semiconductors za III-V. HVPE izwiho ikiguzi cyayo gito cyo gukora, umuvuduko wayo wo gukura vuba, n'ubugari bwa filime. Byakagombye kumenyekana ko HVPEβ-Ga2O3 ikunze kugaragaza imiterere y'ubuso bugoye n'ubucucike bwinshi bw'ibizinga n'imyobo. Kubwibyo, inzira zo gusiga imiti n'imashini zirakenewe mbere yo gukora igikoresho. Ikoranabuhanga rya HVPE kuri epitaxy ya β-Ga2O3 ikunze gukoresha GaCl na O2 nk'intangiriro yo guteza imbere uburyo bwo kugabanya ubushyuhe bwinshi bwa matrix ya (001) β-Ga2O3. Ishusho ya 9 igaragaza imiterere y'ubuso n'umuvuduko wo gukura kwa filime ya epitaxial nk'uko ubushyuhe buhagaze. Mu myaka ya vuba aha, Novel Crystal Technology Inc. yo mu Buyapani yagize icyo igeraho mu bucuruzi muri HVPE homoepitaxial β-Ga2O3, ifite ubunini bwa epitaxial layer bunga na 5 kugeza kuri 10 μm n'ingano ya wafer ya santimetero 2 na 4. Byongeye kandi, wafer za HVPE β-Ga2O3 homoepitaxial zifite ubugari bwa 20 μm zakozwe na China Electronics Technology Group Corporation nazo zinjiye mu rwego rwo kugurisha.

Igishushanyo cya 9 Uburyo bwa HVPE β-Ga2O3

2.4 Uburyo bwa PLD

Ikoranabuhanga rya PLD rikoreshwa cyane cyane mu gushyira filime zikomeye za okiside n'imiterere ya hetero. Mu gihe cyo gukura kwa PLD, ingufu za fotoni zihuzwa n'ikintu kigamije binyuze mu nzira yo gusohora electron. Bitandukanye na MBE, uduce dukomoka kuri PLD tubaho hakoreshejwe imirasire ya laser ifite ingufu nyinshi cyane (>100 eV) hanyuma tugashyirwa ku gice gishyushye. Ariko, mu gihe cyo gukura, uduce duto dukoresha ingufu nyinshi tugira ingaruka zitaziguye ku buso bw'ibikoresho, bigatuma habaho inenge z'ingingo bityo bikagabanya ubwiza bwa filime. Kimwe n'uburyo bwa MBE, RHEED ishobora gukoreshwa mu kugenzura imiterere y'ubuso n'imiterere y'ibikoresho mu gihe nyacyo mu gihe cyo gushyira PLD β-Ga2O3, bigatuma abashakashatsi babona neza amakuru ajyanye n'ikura. Uburyo bwa PLD bwitezweho gukura filime za β-Ga2O3 zikora cyane, bigatuma ziba igisubizo cyiza cyo guhuza ohmic mu bikoresho by'amashanyarazi bya Ga2O3.

Ishusho ya 10 AFM ifoto ya Si doped Ga2O3

Uburyo bwa 2.5 MIST-CVD

MIST-CVD ni ikoranabuhanga ryoroshye kandi rihendutse ryo gukuramo filime nto. Ubu buryo bwa CVD bukubiyemo uburyo bwo gutera umuti wa atome ku gice cy’ubutaka kugira ngo haboneke filime nto. Ariko, kugeza ubu, Ga2O3 yahinzwe hakoreshejwe CVD y’ubushyuhe iracyafite ubushobozi bwiza bw’amashanyarazi, ibi bigatuma habaho umwanya munini wo kunoza no kunoza mu gihe kizaza.