Semiconductor za "wide bandgap" (WBG) zigaragazwa na silicon carbide (SiC) na gallium nitride (GaN) zakunze kwitabwaho cyane. Abantu bafite icyizere kinini ku ikoreshwa rya silicon carbide mu modoka zikoresha amashanyarazi no mu miyoboro y'amashanyarazi, ndetse n'ikoreshwa rya gallium nitride mu gusharija vuba. Mu myaka ya vuba aha, ubushakashatsi ku bikoresho bya Ga2O3, AlN na diyama bwateye imbere cyane, bituma ibikoresho bya "ultra-wide bandgap" biba ibintu byibandwaho cyane. Muri byo, gallium oxide (Ga2O3) ni ibikoresho bya "ultra-wide bandgap" bifite "band gap" ya 4.8 eV, imbaraga z'imashini zikoresha "theory" zingana na 8 MV cm-1, umuvuduko w'amazi wa 2E7cm s-1, na "high Baliga quality factor" ya 3000, yitabwaho cyane mu bijyanye n'amashanyarazi afite voltage nyinshi n'amashanyarazi menshi.
1. Imiterere y'ibikoresho bya Gallium oxide
Ga2O3 ifite icyuho kinini (4.8 eV), byitezwe ko izagera ku bushobozi bwo kwihanganira amashanyarazi menshi ndetse n'ubushobozi bwo hejuru, kandi ishobora kugira ubushobozi bwo guhindura amashanyarazi menshi mu gihe habayeho uburinzi buke, bigatuma ubushakashatsi buriho butangira. Byongeye kandi, Ga2O3 ntabwo ifite imiterere myiza y'ibikoresho gusa, ahubwo inatanga ikoranabuhanga ritandukanye ryoroshye guhindura rya n-type doping, ndetse n'ikoranabuhanga rihendutse ryo gukura kwa substrate na epitaxy. Kugeza ubu, havumbuwe ibice bitanu bitandukanye bya crystal muri Ga2O3, birimo corundum (α), monoclinic (β), spinel ifite inenge (γ), cubic (δ) na orthorhombic (ɛ). Gukomera kwa thermodynamic, mu buryo bukurikiranye, ni γ, δ, α, ɛ, na β. Ni ngombwa kumenya ko monoclinic β-Ga2O3 ari yo ihamye cyane, cyane cyane iyo hari ubushyuhe bwinshi, mu gihe ibindi bice bifite metastable hejuru y'ubushyuhe bw'icyumba kandi bikunda guhinduka β phase mu bihe byihariye by'ubushyuhe. Kubwibyo, iterambere ry'ibikoresho bishingiye kuri β-Ga2O3 ryabaye ikintu cy'ingenzi mu bijyanye n'amashanyarazi mu myaka ya vuba aha.
Imbonerahamwe ya 1 Igereranya ry'ibipimo bimwe na bimwe by'ibikoresho bya semiconductor
Imiterere ya kristu ya monoclinicβ-Ga2O3 igaragara mu mbonerahamwe ya 1. Ibipimo byayo bya lattice birimo a = 12.21 Å, b = 3.04 Å, c = 5.8 Å, na β = 103.8°. Akaremangingo k'igice kagizwe na atome za Ga(I) zifite imiterere ya tetrahedral ihindagurika na atome za Ga(II) zifite imiterere ya octahedral. Hari imiterere itatu itandukanye ya atome za ogisijeni mu "rukurikirane rw'ibice bya "twisted cubic", harimo atome ebyiri za O(I) na O(II) zihuza impande eshatu na atome imwe ya O(III) ihuza tetrahedral. Uruvange rw'ubu bwoko bubiri bw'imiterere ya atome rutuma β-Ga2O3 ihinduka ifite imiterere yihariye muri fiziki, corrosion ya chemical, optique na electronics.
Ishusho ya 1 Ishusho y'imiterere y'icyitegererezo cya monoclinic β-Ga2O3 crystal
Ukurikije inyigisho y’ingufu, agaciro gato k’umugozi w’amashanyarazi wa β-Ga2O3 gakomoka ku miterere y’ingufu ijyanye n’umurongo wa 4s0 wa atome ya Ga. Itandukaniro ry’ingufu hagati y’agaciro gato k’umugozi w’amashanyarazi n’urwego rw’ingufu z’umwuka (ingufu z’amashanyarazi afatanye) ripimwa. Ni 4 eV. Uburemere bwa electron bukoreshwa bwa β-Ga2O3 bupimwa nka 0.28–0.33 me n’uburyo bwiza bwo gutwara amashanyarazi. Ariko, umugozi wa valence ntarengwa ugaragaza umugozi muto wa Ek ufite umugozi muto cyane kandi urimo imiyoboro ya O2p ikomeye, bigaragaza ko imyobo iri mu gace kayo. Iyi miterere itera ikibazo gikomeye cyo kugera ku gupima ubwoko bwa p muri β-Ga2O3. Nubwo gupima ubwoko bwa P bishobora kugerwaho, umwobo μ uguma ku rwego rwo hasi cyane. 2. Gukura kwa gallium oxide imwe crystal Kugeza ubu, uburyo bwo gukura bwa β-Ga2O3 bulk single crystal substrate ahanini ni uburyo bwo gukurura crystal, nka Czochralski (CZ), uburyo bwo kugaburira icyuma gikozwe mu buryo bwa edge-defined thin film (Edge-Defined film-fed, EFG), Bridgman (Bridgman, HB cyangwa VB) n'ikoranabuhanga rya floating zone (floating zone, FZ). Mu buryo bwose, Czochralski n'uburyo bwo kugaburira icyuma gikozwe mu buryo bwa edge-defined thin-film bitezweho kuba inzira nziza cyane yo gukora β-Ga 2O3 wafers mu gihe kizaza, kuko zishobora kugera ku bwinshi icyarimwe kandi zifite inenge nke. Kugeza ubu, Novel Crystal Technology yo mu Buyapani imaze kubona uburyo bwo gucuruza β-Ga2O3 yo gukura mu buryo bwa melt.
1.1 Uburyo bwa Czochralski
Ihame ry'uburyo bwa Czochralski ni uko urwego rw'imbuto rubanza gupfukwa, hanyuma kristu imwe igakurwa buhoro buhoro mu gushonga. Uburyo bwa Czochralski burushaho kuba ingenzi kuri β-Ga2O3 bitewe n'uko buhendutse, ubushobozi bunini, n'ikura ry'ubutaka bwiza bwa kristu. Ariko, bitewe n'ubushyuhe bwinshi mu gihe cy'ikura ry'ubushyuhe bwinshi bwa Ga2O3, hazavuka umwuka wa kristu imwe, ibikoresho bishonga, ndetse no kwangirika kwa Ir crucible. Ibi ni ingaruka z'ingorane zo kugera ku gupima Ga2O3 mu buryo bwa n-type. Kwinjiza ingano ikwiye ya ogisijeni mu kirere gikura ni bumwe mu buryo bwo gukemura iki kibazo. Binyuze mu kunoza, β-Ga2O3 nziza ya santimetero 2 ifite uburebure bwa 10^16~10^19 cm-3 n'ubucucike ntarengwa bwa electron ya 160 cm2/Vs byakuze neza hakoreshejwe uburyo bwa Czochralski.
Ishusho ya 2 Kristale imwe ya β-Ga2O3 yahinzwe hakoreshejwe uburyo bwa Czochralski
1.2 Uburyo bwo kugaburira filime bugenwa n'inkombe
Uburyo bwo kugaburira icyuma gito bugenwe n’inkombe bufatwa nk’ikintu gikomeye mu gukora ibikoresho bya Ga2O3 bifite ubuso bunini bwa kristu imwe. Ihame ry’ubu buryo ni ugushyira icyuma gishongeshejwe mu ibumba gifite agace gato k’umuyoboro, maze icyuma kikazamuka kikagera ku ibumba binyuze mu bikorwa bya kristu. Hejuru, icyuma gito kirema kandi kigakwirakwira mu mpande zose mu gihe giterwa imbaraga na kristu y’imbuto. Byongeye kandi, impande z’isonga ry’ibumba zishobora kugenzurwa kugira ngo hakorwe kristu mu duce duto, imiyoboro, cyangwa imiterere iyo ari yo yose wifuza. Uburyo bwo kugaburira icyuma gito bugenwe n’inkombe bwa Ga2O3 butanga igipimo cyo gukura vuba n’uburebure bunini. Ishusho ya 3 igaragaza igishushanyo cya kristu imwe ya β-Ga2O3. Byongeye kandi, mu bijyanye n’ingano, imiterere ya santimetero 2 na santimetero 4 za β-Ga2O3 ifite ubwiza n’ubugari bwiza yagurishijwe, mu gihe icyuma cya santimetero 6 cyagaragajwe mu bushakashatsi bwo kugurisha mu gihe kizaza. Vuba aha, ibikoresho binini by’uruziga rwa kristu imwe nabyo byabonetse bifite icyerekezo cya (−201). Byongeye kandi, uburyo bwo kugaburira filime bwa β-Ga2O3 bugaragaza impande bunateza imbere gukoresha ibintu by’icyuma bihinduka, bigatuma ubushakashatsi n’itegurwa rya Ga2O3 bishoboka.
Igishushanyo cya 3 β-Ga2O3 kristu imwe yakuze hakoreshejwe uburyo bwo kugaburira filime bugenwa n'inkombe
1.3 Uburyo bwa Bridgeman
Mu buryo bwa Bridgeman, kristu zikorwa mu cyuma gishongeshwa buhoro buhoro kinyura mu bushyuhe. Ubu buryo bushobora gukorwa mu buryo butambitse cyangwa buhagaze, akenshi hakoreshejwe kristu izenguruka. Ni ngombwa kumenya ko ubu buryo bushobora gukoresha imbuto za kristu cyangwa ntibukoreshe. Abakoresha gakondo ba Bridgman ntibabona neza uburyo bwo gushonga no gukura kwa kristu kandi bagomba kugenzura ubushyuhe neza cyane. Ubu buryo bwa Bridgman bukoreshwa cyane cyane mu gukura kwa β-Ga2O3 kandi buzwiho ubushobozi bwo gukura mu kirere. Mu gihe cyo gukura kwa kristu ihagaze, igihombo cyose cya kristu ishongeshwa n’icya kristu kiba kiri munsi ya 1%, bigatuma kristu nini za β-Ga2O3 zikura kandi nta gihombo kinini gihari.
Ishusho ya 4 Kristale imwe ya β-Ga2O3 yahinzwe hakoreshejwe uburyo bwa Bridgeman
1.4 Uburyo bwo gupima ahantu hareremba
Uburyo bwo gupima ahantu hareremba bukemura ikibazo cy’ubwandu bwa kristu buterwa n’ibikoresho byo mu bwoko bwa crucible kandi bugabanya ikiguzi kinini gifitanye isano n’ibikoresho byo mu bwoko bwa infrared birwanya ubushyuhe bwinshi. Muri iki gikorwa cyo gukura, gushonga bishobora gushyushywa n’itara aho gushyushywa n’isoko ya RF, bityo byoroshya ibisabwa ku bikoresho byo gukura. Nubwo imiterere n’ubwiza bwa kristu bya β-Ga2O3 byatewe n’uburyo bwa kristu butaragera ku rwego rwiza, ubu buryo butanga uburyo bwiza bwo guhinga β-Ga2O3 ifite isuku nyinshi mu buryo bworoshye kandi buhendutse.
Ishusho ya 5 β-Ga2O3 kristu imwe yakuze hakoreshejwe uburyo bwa "floating zone".
Igihe cyo kohereza: Gicurasi-30-2024