Ma semiconductors a Wide bandgap (WBG) oimiridwa ndi silicon carbide (SiC) ndi gallium nitride (GaN) alandila chidwi chofala. Anthu amayembekezera kwambiri kugwiritsa ntchito kwa silicon carbide m'magalimoto amagetsi ndi ma gridi amagetsi, komanso chiyembekezo chogwiritsa ntchito gallium nitride pakulipiritsa mwachangu. M'zaka zaposachedwa, kafukufuku wa Ga2O3, AlN ndi zida za diamondi zapita patsogolo kwambiri, zomwe zimapangitsa kuti zida za semiconductor za Ultra-wide bandgap kukhala chidwi. Pakati pawo, gallium okusayidi (Ga2O3) ndi akutulukira kopitilira muyeso-lonse-bandgap semiconductor zakuthupi ndi gulu kusiyana 4.8 eV, ongoyerekeza yovuta kusweka munda mphamvu za 8 MV cm-1, machulukitsidwe liwiro la za 2E7cm s-1, ndi gawo lapamwamba la Baliga la 3000, likulandira chidwi chofala m'munda wamagetsi apamwamba komanso ma frequency apamwamba. zamagetsi zamagetsi.
1. Gallium okusayidi zinthu makhalidwe
Ga2O3 ili ndi kusiyana kwakukulu kwa bandi (4.8 eV), ikuyembekezeka kukwanitsa kupirira voteji ndi mphamvu zambiri zamphamvu, ndipo imatha kukhala ndi kuthekera kwa kusinthasintha kwamagetsi apamwamba pa kukana kotsika, kuwapanga kukhala cholinga cha kafukufuku wapano. Kuphatikiza apo, Ga2O3 sikuti ili ndi zinthu zabwino zokha, komanso imapereka umisiri wosinthika mosavuta wa n-mtundu wa doping, komanso kukula kwa gawo lapansi lotsika mtengo komanso matekinoloje a epitaxy. Pakalipano, magawo asanu a kristalo apezeka mu Ga2O3, kuphatikizapo corundum (α), monoclinic (β), defective spinel (γ), cubic (δ) ndi orthorhombic (ɛ) phases. Kukhazikika kwa Thermodynamic ndi, mwadongosolo, γ, δ, α, ɛ, ndi β. Ndikoyenera kudziwa kuti monoclinic β-Ga2O3 ndiyokhazikika kwambiri, makamaka pa kutentha kwakukulu, pamene magawo ena amatha kusungunuka pamwamba pa kutentha kwa chipinda ndipo amasintha kukhala β gawo pansi pa kutentha kwapadera. Chifukwa chake, kupanga zida zokhazikitsidwa ndi β-Ga2O3 kwakhala kofunikira kwambiri pazamagetsi zamagetsi m'zaka zaposachedwa.
Table 1 Kuyerekeza kwa magawo ena a semiconductor
Mapangidwe a kristalo a monoclinicβ-Ga2O3 akuwonetsedwa mu Table 1. Zigawo zake za lattice zimaphatikizapo = 12.21 Å, b = 3.04 Å, c = 5.8 Å, ndi β = 103.8 °. The unit cell imakhala ndi ma atomu a Ga(I) okhala ndi mgwirizano wopindika wa tetrahedral ndi ma atomu a Ga(II) okhala ndi mgwirizano wa octahedral. Pali mitundu itatu yosiyana ya maatomu a okosijeni mugulu la "mopindika wa kiyubiki", kuphatikiza ma atomu awiri olumikizana katatu O(I) ndi O(II) ndi ma atomu a O(III) omwe amalumikizana ndi tetrahedral. Kuphatikiza kwa mitundu iwiriyi ya kugwirizanitsa kwa atomiki kumatsogolera ku anisotropy ya β-Ga2O3 yokhala ndi katundu wapadera mufizikiki, corrosion mankhwala, optics ndi zamagetsi.
Chithunzi 1 Chojambula chojambula cha monoclinic β-Ga2O3 crystal
Kuchokera ku lingaliro la mphamvu ya band band, mtengo wocheperako wa band conduction wa β-Ga2O3 umachokera ku mphamvu ya mphamvu yofanana ndi 4s0 hybrid orbit ya Ga atomu. Kusiyana kwa mphamvu pakati pa mtengo wocheperako wa band conduction ndi vacuum energy level (electron affinity energy) imayesedwa. ndi 4ev. Ma elekitironi amphamvu a β-Ga2O3 amayezedwa ngati 0.28-0.33 me ndi mphamvu zake zamagetsi zamagetsi. Komabe, gulu lalikulu la valence limawonetsa mapindikidwe osaya a Ek okhala ndi kupindika kotsika kwambiri komanso ma orbitals a O2p, zomwe zikuwonetsa kuti mabowowo amakhala akumalo. Makhalidwewa amapereka vuto lalikulu kuti akwaniritse doping ya p mu β-Ga2O3. Ngakhale doping yamtundu wa P ikhoza kukwaniritsidwa, dzenje μ limakhalabe lotsika kwambiri. 2. Kukula kwa kristalo wochuluka wa gallium oxide single crystal Pakalipano, njira ya kukula kwa β-Ga2O3 yochuluka yamtundu umodzi wa kristalo ndi njira yokoka kristalo, monga Czochralski (CZ), njira yowonetsera m'mphepete mwa filimu yopyapyala (Edge -Defined film-fed , EFG), Bridgman (yokwera kapena yopingasa Bridgman, HB kapena VB) ndi malo oyandama (oyandama zone, FZ) luso. Pakati pa njira zonse, Czochralski ndi njira zochepetsera zochepetsetsa zochepetsera mafilimu zimayembekezeredwa kukhala njira zodalirika kwambiri zopangira β-Ga 2O3 wafers m'tsogolomu, chifukwa nthawi imodzi amatha kukwaniritsa ma volumes akuluakulu ndi kuchepa kochepa. Mpaka pano, Novel Crystal Technology yaku Japan yazindikira malonda osungunuka kukula kwa β-Ga2O3.
1.1 Njira ya Czochralski
Mfundo ya njira ya Czochralski ndi yakuti mbewu yosanjikiza imayikidwa poyamba, ndiyeno kristalo imodzi imatulutsidwa pang'onopang'ono kuchokera kusungunuka. Njira ya Czochralski ndiyofunika kwambiri kwa β-Ga2O3 chifukwa cha mtengo wake, mphamvu zazikulu zazikulu, ndi kukula kwapamwamba kwa gawo lapansi la kristalo. Komabe, chifukwa cha kupsinjika kwa kutentha pakukula kwa kutentha kwa Ga2O3, kutuluka kwa makristasi amodzi, kusungunuka kwa zinthu, ndi kuwonongeka kwa Ir crucible kudzachitika. Izi ndi zotsatira za vuto lopeza doping yamtundu wa n mu Ga2O3. Kubweretsa mpweya wokwanira mumlengalenga wakukula ndi njira imodzi yothetsera vutoli. Kupyolera mu kukhathamiritsa, 2-inch β-Ga2O3 yapamwamba kwambiri yokhala ndi ma elekitironi omasuka a 10 ^ 16 ~ 10 ^ 19 cm-3 ndi kuchuluka kwa ma electron 160 cm2 / Vs kwakula bwino ndi njira ya Czochralski.
Chithunzi 2 Single crystal ya β-Ga2O3 yokula ndi njira ya Czochralski
1.2 Njira yodyetsera mafilimu yofotokozedwa m'mphepete
Njira yodyetsera filimu yopyapyala yofotokozedwa m'mphepete imaonedwa kuti ndiyomwe ikutsogolera pakupanga malonda a Ga2O3 single crystal materials. Mfundo ya njirayi ndikuyika chosungunula mu nkhungu ndi kupasuka kwa capillary, ndipo kusungunuka kumakwera ku nkhungu kupyolera mu capillary action. Pamwamba, filimu yopyapyala imapanga ndikufalikira mbali zonse kwinaku ikulimbikitsidwa kuti iwonekere ndi kristalo wa mbewu. Kuphatikiza apo, m'mphepete mwa nkhungu pamwamba imatha kuwongoleredwa kuti apange makhiristo mu flakes, machubu, kapena geometry iliyonse yomwe mukufuna. Njira yowonetsera m'mphepete mwa filimu yopyapyala ya Ga2O3 imapereka kukula kwachangu komanso ma diameter akulu. Chithunzi cha 3 chikuwonetsa chithunzi cha crystal imodzi ya β-Ga2O3. Kuonjezera apo, potengera kukula kwake, magawo a 2-inch ndi 4-inch β-Ga2O3 omwe ali ndi kuwonekera bwino kwambiri komanso kufanana kwakhala akugulitsidwa, pamene gawo la 6-inch likuwonetsedwa mu kafukufuku wa malonda amtsogolo. Posachedwapa, zida zazikulu zozungulira zamtundu umodzi wakristalo zapezekanso ndi (−201). Kuphatikiza apo, njira yodyetsera filimu ya β-Ga2O3 m'mphepete imalimbikitsanso doping ya zinthu zachitsulo zosinthira, zomwe zimapangitsa kuti kafukufuku ndi kukonzekera Ga2O3 zitheke.
Chithunzi 3 β-Ga2O3 kristalo imodzi yomwe imakula ndi njira yowonetsera filimu yowonetsera m'mphepete
1.3 Njira ya Bridgeman
Mu njira ya Bridgeman, makhiristo amapangidwa mu crucible yomwe imasunthidwa pang'onopang'ono kupyolera mu kutentha kwa kutentha. Njirayi imatha kuchitidwa molunjika kapena molunjika, nthawi zambiri pogwiritsa ntchito crucible yozungulira. Ndikoyenera kudziwa kuti njirayi ingagwiritse ntchito mbewu za kristalo kapena ayi. Ogwiritsa ntchito a Bridgman achikhalidwe alibe mawonekedwe achindunji a kusungunuka ndi kukula kwa kristalo ndipo amayenera kuwongolera kutentha mwatsatanetsatane. Njira yowongoka ya Bridgman imagwiritsidwa ntchito makamaka pakukula kwa β-Ga2O3 ndipo imadziwika kuti imatha kukula mumlengalenga. Panthawi ya kukula kwa njira ya Bridgman, kutayika kwathunthu kwa kusungunula ndi crucible kumasungidwa pansi pa 1%, zomwe zimathandiza kukula kwa makristasi akuluakulu a β-Ga2O3 osatayika pang'ono.
Chithunzi 4 Single crystal ya β-Ga2O3 yokula ndi njira ya Bridgeman
1.4 Njira yoyandama yoyandama
Njira yoyandama yoyandama imathetsa vuto la kuipitsidwa kwa kristalo ndi zida zomangira ndikuchepetsa mtengo wokwera wokhudzana ndi kutentha kwapang'onopang'ono kugonjetsedwa ndi ma infrared crucibles. Pakukula uku, kusungunula kumatha kuyatsidwa ndi nyali m'malo mwa gwero la RF, motero kumathandizira zofunikira pakukula kwa zida. Ngakhale mawonekedwe ndi mtundu wa kristalo wa β-Ga2O3 wokulitsidwa ndi njira yoyandama yoyandama sizinali bwino, njirayi imatsegula njira yodalirika yokulitsira β-Ga2O3 yoyera kwambiri kukhala makhiristo amodzi ogwirizana ndi bajeti.
Chithunzi 5 β-Ga2O3 crystal imodzi yomwe imakula ndi njira yoyandama.
Nthawi yotumiza: May-30-2024