Ua loaʻa i ka manaʻo nui nā mea hoʻohālike o ka bandgap ākea (WBG) i hōʻike ʻia e ka silicon carbide (SiC) a me ka gallium nitride (GaN). Loaʻa i nā poʻe nā manaʻolana kiʻekiʻe no ka hoʻohana ʻana i ka silicon carbide i nā kaʻa uila a me nā mana mana, a me nā manaʻo noi o gallium nitride i ka hoʻouka wikiwiki. I nā makahiki i hala iho nei, ua holomua nui ka noiʻi ʻana ma Ga2O3, AlN a me nā mea daimana, e hana ana i nā mea semiconductor ultra-wide bandgap i mea nui o ka nānā. Ma waena o lākou, ʻo ka gallium oxide (Ga2O3) kahi mea semiconductor ultra-wide-bandgap e puka mai ana me kahi ʻāpana o 4.8 eV, kahi ikaika o ke kahua haʻihaʻi koʻikoʻi ma kahi o 8 MV cm-1, kahi wikiwiki saturation ma kahi o 2E7cm s-1, a me kahi mea kiʻekiʻe Baliga maikaʻi o 3000, e loaʻa ana ka manaʻo ākea ma ke kahua o ka uila kiʻekiʻe a me ka uila uila kiʻekiʻe.
1. ʻO nā hiʻohiʻona o ka galium oxide
Loaʻa i ka Ga2O3 kahi āwāwa nui (4.8 eV), manaʻo ʻia e hoʻokō i nā mana kūʻokoʻa kiʻekiʻe a me nā mana mana kiʻekiʻe, a hiki ke loaʻa i ka hiki ke hiki ke hoʻololi i ka volta kiʻekiʻe ma ke kū haʻahaʻa haʻahaʻa, e hoʻolilo iā lākou i kumu o ka noiʻi o kēia manawa. Eia kekahi, ʻaʻole loaʻa iā Ga2O3 nā waiwai waiwai maikaʻi loa, akā hāʻawi pū kekahi i nā ʻano ʻenehana doping n-type maʻalahi, a me ka ulu haʻahaʻa substrate a me nā ʻenehana epitaxy. I kēia manawa, ua ʻike ʻia nā ʻāpana aniani ʻelima ma Ga2O3, me ka corundum (α), monoclinic (β), defective spinel (γ), cubic (δ) a me orthorhombic (ɛ). ʻO nā kūpaʻa Thermodynamic, ma ke ʻano, γ, δ, α, ɛ, a me β. Pono e hoʻomaopopo ʻia ʻo ka monoclinic β-Ga2O3 ka mea paʻa loa, ʻoi aku ka nui ma nā wela kiʻekiʻe, ʻoiai ʻo nā ʻāpana ʻē aʻe he metastable ma luna o ka mahana o ka lumi a makemake e hoʻololi i ka pae β ma lalo o nā kūlana wela. No laila, ua lilo ka hoʻomohala ʻana o nā mea hoʻohana β-Ga2O3 i mea nui i ke kahua o ka uila uila i nā makahiki i hala.
Papa 1 Ka hoohalike ana o kekahi mau mea semiconductor
Hōʻike ʻia ke ʻano aniani o ka monoclinicβ-Ga2O3 ma ka Papa 1. ʻO nā ʻāpana lattice he a = 12.21 Å, b = 3.04 Å, c = 5.8 Å, a me β = 103.8°. Aia i loko o ka pūnaewele nā ʻātoma Ga(I) me ka hui ʻana tetrahedral wili a me nā ʻātoma Ga(II) me ka hoʻohui ʻana octahedral. ʻEkolu hoʻonohonoho ʻokoʻa o nā ʻātoma oxygen i loko o ka pūʻulu "twisted cubic", me nā ʻātoma hoʻohui ʻelua triangularly O(I) a me O(II) a me hoʻokahi atom O(III) i hui pū ʻia tetrahedrally. ʻO ka hui pū ʻana o kēia mau ʻano ʻelua o ka coordination atomic e alakaʻi i ka anisotropy o β-Ga2O3 me nā waiwai kūikawā i ka physics, chemical corrosion, optics a me ka uila.
Kiʻi 1 Schematic structural diagram of monoclinic β-Ga2O3 crystal
Mai ka manaʻo o ka manaʻo pūnaʻi ikehu, loaʻa ka waiwai liʻiliʻi o ka hui hoʻokele o β-Ga2O3 mai ke kūlana ikehu e pili ana i ka orbit hybrid 4s0 o ka Ga atom. Ua ana ʻia ka ʻokoʻa o ka ikehu ma waena o ka waiwai liʻiliʻi o ka hui hoʻokele a me ka pae ikehu (electron affinity energy). he 4 eV. ʻO ka nui o ka electron pono o β-Ga2O3 ua ana ʻia ʻo 0.28–0.33 me a me kona conductivity uila maikaʻi. Eia naʻe, ke hōʻike nei ka nui o ka pā valence i kahi pāpaʻu Ek me ka haʻahaʻa haʻahaʻa a me nā orbital O2p i hoʻopaʻa ikaika ʻia, e manaʻo ana ua ʻike ʻia nā lua. He paʻakikī nui kēia mau hiʻohiʻona e hoʻokō i ka doping p-type ma β-Ga2O3. ʻOiai inā hiki ke hoʻokō ʻia ka doping P-type, noho ka lua μ ma kahi pae haʻahaʻa loa. 2. Ka ulu ana o ka bulk gallium oxide hookahi aniani I keia manawa, o ke ano o ka ulu ana o ka β-Ga2O3 bulk one crystal substrate ka mea nui ke ano e huki ana i ke aniani, e like me Czochralski (CZ), ke ano hanai kiʻi lahilahi i kapaia (Edge -Defined film-fed). , EFG), Bridgman (Rtical or horizontal Bridgman, HB or VB) a me ka ʻenehana lana (floating zone, FZ). Ma waena o nā ʻano hana a pau, ʻo Czochralski a me nā ʻano hana hānai kiʻiʻoniʻoni i hoʻohālikelike ʻia i ka ʻaoʻao i manaʻo ʻia ʻo ia nā ala ʻoi loa no ka hana nui ʻana o nā wafers β-Ga 2O3 i ka wā e hiki mai ana, no ka mea hiki iā lākou ke hoʻokō i nā puke nui a me nā haʻahaʻa haʻahaʻa haʻahaʻa. A hiki i kēia manawa, ua ʻike ʻo Iapana's Novel Crystal Technology i kahi matrix kalepa no ka ulu hoʻoheheʻe β-Ga2O3.
1.1 Keʻano Czochralski
ʻO ke kumu o ke ʻano Czochralski, ʻo ia ka uhi mua ʻana o ka papa hua, a laila huki mālie ʻia ke aniani hoʻokahi mai ka heheʻe. ʻOi aku ka nui o ke ʻano Czochralski no β-Ga2O3 ma muli o kona kumukūʻai-pono, nā mana nui nui, a me ka ulu ʻana o ka substrate maikaʻi kiʻekiʻe. Eia nō naʻe, ma muli o ke koʻikoʻi wela i ka ulu ʻana o ka wela kiʻekiʻe o Ga2O3, e hoʻoheheʻe ʻia nā kristal hoʻokahi, nā mea hoʻoheheʻe, a me ka pōʻino i ka Ir crucible. ʻO kēia ka hopena o ka paʻakikī i ka loaʻa ʻana o ka haʻahaʻa n-type doping ma Ga2O3. ʻO ka hoʻokomo ʻana i ka nui kūpono o ka oxygen i loko o ka lewa ulu kahi ala e hoʻoponopono ai i kēia pilikia. Ma o ka optimization, kiʻekiʻe 2-inihi β-Ga2O3 me ka noa electron hoʻopaʻa 'ia o 10^16~10^19 cm-3 a me ka kiekie electron density o 160 cm2/Vs ua holomua me ka Czochralski ala.
Kiʻi 2 Hoʻokahi aniani o β-Ga2O3 i ulu ʻia e ke ʻano Czochralski
1.2 Keʻano hana hānai kiʻiʻoniʻoni i wehewehe ʻia
ʻO ke ʻano hana hānai kiʻiʻoniʻoni ʻoniʻoni i hoʻohālikelike ʻia i ka ʻaoʻao i manaʻo ʻia ʻo ia ka mea hoʻokūkū koʻikoʻi no ka hana pāʻoihana o nā mea aniani hoʻokahi Ga2O3 nui. ʻO ke kumumanaʻo o kēia ʻano hana ke kau ʻana i ka hoʻoheheʻe ʻana i loko o kahi pahu me kahi ʻāpana capillary, a piʻi ka hoʻoheheʻe ʻana i ka mold ma o ka hana capillary. Ma luna, hana ʻia kahi kiʻiʻoniʻoni lahilahi a pālahalaha ʻia ma nā ʻaoʻao āpau i ka wā e hoʻoulu ʻia e crystallize e ka ʻanoʻano aniani. Hoʻohui ʻia, hiki ke hoʻomalu ʻia nā ʻaoʻao o ka mold top e hana i nā kristal i loko o nā flakes, tubes, a i ʻole geometry makemake ʻia. Hāʻawi ke ʻano hana hānai kiʻiʻoniʻoni lahilahi o Ga2O3 i ka ulu wikiwiki a me nā anawaena nui. Hōʻike ka Kiʻi 3 i ke kiʻikuhi o kahi aniani β-Ga2O3 hoʻokahi. Eia kekahi, ma ke ʻano o ka nui, ua kūʻai ʻia nā substrate 2-inch a me 4-inch β-Ga2O3 me ke aniani maikaʻi loa a me ke kūlike, ʻoiai ke hōʻike ʻia nei ka substrate 6-inch i ka noiʻi no ka hoʻolaha ʻana i ka wā e hiki mai ana. I kēia mau lā, ua loaʻa pū nā mea nui pōʻai pōʻai hoʻokahi-crystal nui me ka (−201) orientation. Eia kekahi, ʻo ke ʻano hānai kiʻiʻoniʻoni i wehewehe ʻia e ka β-Ga2O3 e paipai i ka doping o nā mea metala hoʻololi, e hiki ai i ka noiʻi a me ka hoʻomākaukau ʻana o Ga2O3.
Kiʻi 3 β-Ga2O3 aniani hoʻokahi i ulu ʻia e ke ʻano hana hānai kiʻiʻoniʻoni i wehewehe ʻia
1.3 ʻO ke ala Bridgeman
Ma ke ala Bridgeman, ua hoʻokumu ʻia nā kristal i loko o kahi crucible i hoʻoneʻe mālie ʻia ma o ka gradient wela. Hiki ke hana ʻia ke kaʻina hana ma ke ʻano ākea a kū pololei paha, me ka hoʻohana pinepine ʻana i kahi crucible rotating. He mea pono e hoʻomaopopo i kēia ʻano hana a hoʻohana paha i nā hua kristal. Loaʻa i nā mea hoʻohana Bridgman kuʻuna i ka nānā pono ʻana i nā kaʻina hoʻoheheʻe a me ka ulu aniani a pono e hoʻomalu i nā mahana me ka pololei kiʻekiʻe. Hoʻohana nui ʻia ke ala ʻo Bridgman vertical no ka ulu ʻana o β-Ga2O3 a ʻike ʻia no kona hiki ke ulu i kahi ea. I ka wā o ke kaʻina hana ulu ʻana o Bridgman, mālama ʻia ka nui o ka pohō o ka hehee a me ka crucible ma lalo o 1%, e hiki ai i ka ulu ʻana o nā kristal nui β-Ga2O3 me ka liʻiliʻi o ka pohō.
Kiʻi 4 Hoʻokahi aniani o β-Ga2O3 i ulu ʻia e ke ala Bridgeman
1.4 Ke ʻano o ka ʻāpana lana
Hoʻoponopono ke ʻano o ka floating zone i ka pilikia o ka hoʻohaumia ʻana i ka kristal e nā mea crucible a hoʻemi i nā kumukūʻai kiʻekiʻe e pili ana i nā crucibles infrared kūʻokoʻa kiʻekiʻe. I loko o kēia kaʻina ulu, hiki ke hoʻomehana ʻia ka hoʻoheheʻe ʻia e kahi kukui ma mua o kahi kumu RF, no laila e maʻalahi i nā koi no nā mea ulu. ʻOiai ʻaʻole maikaʻi loa ke ʻano a me ka maikaʻi aniani o ka β-Ga2O3 i ulu ʻia e ke ʻano lana ʻana, ua wehe kēia ʻano hana i kahi ala hoʻohiki no ka hoʻoulu ʻana i ka β-Ga2O3 maʻemaʻe kiʻekiʻe i loko o nā kristal hoʻokahi pili kālā.
Kiʻi 5 β-Ga2O3 aniani hoʻokahi i hoʻoulu ʻia e ke ʻano o ka ʻāpana lana.
Ka manawa hoʻouna: Mei-30-2024