I-Wide bandgap (WBG) semiconductors emelwe yi-silicon carbide (SiC) kunye ne-gallium nitride (GaN) ifumene ingqwalasela ebanzi. Abantu banolindelo oluphezulu kwizicelo ezilindelekileyo ze-silicon carbide kwizithuthi zombane kunye neegridi zamandla, kunye nethemba lesicelo se-gallium nitride ekutshajisweni ngokukhawuleza. Kwiminyaka yakutshanje, uphando kwi-Ga2O3, i-AlN kunye nezixhobo zedayimani zenze inkqubela phambili ephawulekayo, okwenza i-ultra-wide bandgap semiconductor imathiriyeli ingqalelo. Phakathi kwazo, i-gallium oxide (i-Ga2O3) yinto ephumayo ye-ultra-wide-bandgap semiconductor kunye ne-band gap ye-4.8 eV, i-theory ye-theory ebalulekileyo yentsimi yamandla malunga ne-8 MV cm-1, i-saturation ye-saturation malunga ne-2E7cm s-1, kunye nomgangatho ophezulu we-Baliga we-3000, ukufumana ingqalelo ebanzi kwintsimi yombane ophezulu kunye nokuphakama okuphezulu amandla e-elektroniki.
1. Iimpawu zezinto ze-Gallium oxide
I-Ga2O3 inomsantsa omkhulu webhendi (i-4.8 eV), kulindeleke ukuba ifezekise zombini i-voltage ephezulu yokumelana kunye namandla aphezulu ombane, kwaye inokuba namandla okuguquguquka kwamandla ombane aphezulu ngokuxhathisa okuphantsi, okubenza babe ingqwalasela yophando lwangoku. Ukongeza, i-Ga2O3 ayinayo ipropathi egqwesileyo yempahla kuphela, kodwa ikwabonelela ngeendlela ezahlukeneyo zohlobo lwetekhnoloji yedoping elungelelanisiweyo, kunye nokukhula kwe-substrate enexabiso eliphantsi kunye nobuchwepheshe be-epitaxy. Ukuza kuthi ga ngoku, izigaba ze-crystal ezihlanu ezihlukeneyo zifunyenwe kwi-Ga2O3, kuquka i-corundum (α), i-monoclinic (β), i-spinel ephosakeleyo (γ), i-cubic (δ) kunye ne-orthorhombic (ɛ) izigaba. Uzinzo lweThermodynamic lu, ngokolandelelwano, γ, δ, α, ɛ, kunye β. Kuyafaneleka ukuba uqaphele ukuba i-monoclinic β-Ga2O3 yeyona nto izinzile, ngakumbi kumaqondo obushushu aphezulu, ngelixa ezinye izigaba zine-metastable ngaphezu kweqondo lokushisa kwaye zivame ukuguqula kwisigaba se-β phantsi kweemeko ezithile zokushisa. Ngoko ke, ukuphuhliswa kwezixhobo ezisekelwe kwi-β-Ga2O3 kuye kwaba yingqwalasela enkulu kwintsimi yombane wamandla kwiminyaka yamuva.
Itheyibhile 1 Ukuthelekiswa kwezinye iiparamitha ze-semiconductor
Isakhiwo sekristale ye-monoclinicβ-Ga2O3 iboniswe kwiThebhile 1. Iiparamitha zayo ze-lattice ziquka i = 12.21 Å, b = 3.04 Å, c = 5.8 Å, kunye ne-β = 103.8 °. Iyunithi yeseli iqulathe iiathom ze-Ga(I) ezinolungelelwaniso olujijekileyo lwe-tetrahedral kunye nee-athom ze-Ga(II) ezinolungelelwaniso lwe-octahedral. Kukho ulungelelwaniso oluthathu olwahlukeneyo lweeathom ze-oxygen kwi-"twisted cubic" uluhlu, kubandakanywa ii-athom ezimbini ezilungelelaniswe ngonxantathu we-O (I) kunye ne-O (II) kunye ne-athomu enye ye-tetrahedral e-O(III). Ukudibanisa kwezi ntlobo zimbini zokulungelelaniswa kwe-athomu kukhokelela kwi-anisotropy ye-β-Ga2O3 eneepropati ezikhethekileyo kwi-physics, i-chemical corrosion, i-optics kunye ne-electronics.
Umzobo we-1 Umzobo wesakhiwo se-monoclinic β-Ga2O3 crystal
Ukususela kumbono we-theory ye-band band, ixabiso elincinci le-conduction band ye-β-Ga2O3 liphuma kwimeko yamandla ehambelana ne-4s0 hybrid orbit ye-athomu ye-Ga. Umahluko wamandla phakathi kwexabiso elincinci lebhendi yokuqhuba kunye nenqanaba lamandla e-vacuum (i-electron affinity energy) iyalinganiswa. yi 4eV. Ubunzima be-electron obusebenzayo be-β-Ga2O3 bulinganiswa njenge-0.28–0.33 me kunye ne-electronic conductivity efanelekileyo. Nangona kunjalo, ubuninzi bebhendi ye-valence bubonisa igophe le-Ek elingekho nzulu eligophe eliphantsi kakhulu kunye nee-orbitals ze-O2p zasekhaya, ezibonisa ukuba imingxuma yenziwe yasekhaya ngokunzulu. Ezi mpawu zibeka umngeni omkhulu ukuphumeza i-p-type doping kwi-β-Ga2O3. Nokuba i-P-type doping inokufezekiswa, umngxuma μ uhlala kwinqanaba eliphantsi kakhulu. 2. Ukukhula kobuninzi be-gallium oxide ikristale enye Ukuza kuthi ga ngoku, indlela yokukhula ye-β-Ga2O3 yobuninzi be-crystal substrate yindlela yokutsala i-crystal, njenge-Czochralski (CZ), i-edge-defined thin film feeding method (Edge -Defined film-fed). , EFG), Bridgman (ethe nkqo okanye ethe tye iBridgman, HB okanye VB) kunye nendawo edadayo (edadayo zone, FZ) iteknoloji. Phakathi kwazo zonke iindlela, i-Czochralski kunye ne-edge-defined thin-film feeding method kulindeleke ukuba ibe yizona ndlela zithembisayo zokuvelisa ubuninzi be-β-Ga 2O3 wafers kwixesha elizayo, njengoko banokufikelela ngaxeshanye imiqulu emikhulu kunye noxinzelelo oluphantsi. Ukuza kuthi ga ngoku, iTekhnoloji yeNoveli yeCrystal yaseJapan ifumene imatrix yorhwebo yokunyibilika kokukhula kwe-β-Ga2O3.
2.1 Indlela yeCzochralski
Umgaqo weCzochralski yindlela yokuba i-seed layer igutyungelwe kuqala, kwaye i-crystal enye ikhutshwe ngokukhawuleza ekunyibilikeni. Indlela ye-Czochralski ibaluleke kakhulu kwi-β-Ga2O3 ngenxa yeendleko zayo, amandla amakhulu obungakanani, kunye nokukhula kwe-crystal quality substrate ephezulu. Nangona kunjalo, ngenxa yoxinzelelo lwe-thermal ngexesha lokukhula kobushushu obuphezulu be-Ga2O3, ukuvela kwe-crystals enye, izinto ezinyibilikayo, kunye nomonakalo kwi-Ir crucible kuya kwenzeka. Esi sisiphumo sobunzima bokufumana idoping ephantsi yohlobo lwe-n kwi-Ga2O3. Ukwazisa isixa esifanelekileyo seoksijini kwindawo yokukhula yenye yeendlela zokusombulula le ngxaki. Ngokusebenzisa ukulungiswa, umgangatho ophezulu we-2-intshi β-Ga2O3 kunye ne-electron concentration yamahhala ye-10 ^ 16 ~ 10 ^ 19 cm-3 kunye ne-electron density ye-160 cm2 / Vs ikhule ngempumelelo ngendlela yeCzochralski.
Umzobo 2 Ikristale enye ye-β-Ga2O3 ekhuliswe yindlela yeCzochralski
2.2 Indlela yokutyisa ifilimu echazwe nguMda
Indlela yokutya yefilimu encinci echazwe emaphethelweni ithathwa njengeyona nto iphambili kwimveliso yentengiso yendawo enkulu ye-Ga2O3 yezinto zekristale enye. Umgaqo wale ndlela kukubeka i-melt kwi-mold kunye ne-capillary slit, kwaye i-melt iphakama kwi-mold ngokusebenzisa isenzo se-capillary. Phezulu, ifilimu encinci ifom kwaye isasazeka kuwo onke amacala ngelixa ikhuthazwa ukuba ikhazimle yikristale yembewu. Ukongeza, imiphetho ye-mold top inokulawulwa ukuvelisa iikristale kwiiflakes, iityhubhu, okanye nayiphi na ijometri efunwayo. Indlela yokutya yefilimu encinci ye-edge ye-Ga2O3 ibonelela ngamazinga okukhula ngokukhawuleza kunye nobubanzi obukhulu. Umzobo we-3 ubonisa umzobo we-crystal β-Ga2O3 enye. Ukongezelela, ngokwemilinganiselo yobungakanani, i-2-intshi kunye ne-4-intshi ye-β-Ga2O3 i-substrates ene-transparency egqwesileyo kunye nokufanayo ziye zathengiswa, ngelixa i-substrate ye-6-intshi ibonakaliswe kuphando lwentengiso yexesha elizayo. Kutshanje, imathiriyeli enkulu esetyhula ye-single-crystal bulk nayo iye yafumaneka kunye ne-(−201) yokuqhelaniswa. Ukongezelela, i-β-Ga2O3 edge-defined film feeding method iphinda ikhuthaze i-doping yezinto zetsimbi zenguqu, okwenza uphando kunye nokulungiswa kwe-Ga2O3 kunokwenzeka.
Umzobo we-3 β-Ga2O3 ikristale enye ekhuliswe yindlela yokutya yefilimu eqingqiweyo
2.3 Indlela kaBridgeman
Kwindlela yeBridgeman, iikristale zenziwe kwi-crucible ehamba ngokuthe ngcembe ngeqondo lobushushu. Inkqubo inokwenziwa kwi-horizontal orientation orientation, ngokuqhelekileyo isebenzisa i-crucible ejikelezayo. Kuyafaneleka ukuba uqaphele ukuba le ndlela inokusebenzisa okanye ingasebenzisi imbewu yekristale. Abaqhubi beBridgman bemveli abanalo ukubonwa ngokuthe ngqo kweenkqubo zokunyibilika kunye nokukhula kwekristale kwaye kufuneka balawule amaqondo obushushu ngokuchaneka okuphezulu. Indlela ye-Bridgman ethe nkqo isetyenziselwa ukukhula kwe-β-Ga2O3 kwaye iyaziwa ngokukwazi ukukhula kwindawo yomoya. Ngethuba lenkqubo yokukhula ye-Bridgman ye-vertical, i-mass mass loss of the melt kunye ne-crucible igcinwa ngaphantsi kwe-1%, eyenza ukukhula kwe-crystals enkulu ye-β-Ga2O3 kunye nokulahlekelwa okuncinci.
Umzobo 4 Ikristale enye ye-β-Ga2O3 ekhuliswe yindlela yeBridgeman
2.4 Indlela yezowuni edadayo
Indlela yezowuni edadayo isombulula ingxaki yokungcoliseka kwekristale ngezinto ezinqamlezileyo kunye nokunciphisa iindleko eziphakamileyo ezihambelana nobushushu obuphezulu be-infrared crucibles. Ngexesha lenkqubo yokukhula, ukunyibilika kunokufudunyezwa ngesibane kunomthombo weRF, ngaloo ndlela kube lula iimfuno zezixhobo zokukhula. Nangona imilo kunye nomgangatho wekristale ye-β-Ga2O3 ekhuliswe yindlela yendawo edadayo ayikabikho, le ndlela ivula indlela ethembisayo yokukhulisa ubunyulu obuphezulu be-β-Ga2O3 kwiikristale ezilungele uhlahlo lwabiwo-mali.
Umzobo 5 β-Ga2O3 ikristale enye ekhuliswe ngendlela yendawo edadayo.
Ixesha lokuposa: May-30-2024