Wide bandgap (WBG) semiconductor wanda silicon carbide (SiC) da gallium nitride (GaN) ke wakilta sun sami kulawa sosai. Mutane suna da babban tsammanin neman aikace-aikacen siliki carbide a cikin motocin lantarki da grid ɗin wuta, da kuma tsammanin aikace-aikacen gallium nitride a cikin caji mai sauri. A cikin 'yan shekarun nan, bincike a kan Ga2O3, AlN da kayan lu'u-lu'u sun sami ci gaba mai mahimmanci, suna mai da manyan abubuwan bandgap semiconductor mai da hankali. Daga cikin su, gallium oxide (Ga2O3) wani abu ne mai tasowa mai girma-fadi-bandgap semiconductor abu tare da band rata na 4.8 eV, ka'idar m m rushewar filin ƙarfi na game da 8 MV cm-1, wani jikewa gudu na game da 2E7cm s-1. da kuma babban darajar Baliga na 3000, yana karɓar kulawa mai yawa a fagen babban ƙarfin lantarki da ƙarfin mitar mita. kayan lantarki.
1. Gallium oxide abu halaye
Ga2O3 yana da babban rata na band (4.8 eV), ana sa ran cimma duka ƙarfin juriya da ƙarfin ƙarfin ƙarfi, kuma yana iya samun yuwuwar ƙarfin ƙarfin ƙarfin ƙarfin ƙarfin ƙarfin ƙarfi a ƙaramin juriya, yana mai da hankali kan bincike na yanzu. Bugu da ƙari, Ga2O3 ba wai kawai yana da kyawawan kaddarorin kayan abu ba, amma kuma yana ba da nau'ikan fasahar doping iri-iri masu sauƙin daidaitawa, da haɓakar ƙarancin farashi da fasahar epitaxy. Ya zuwa yanzu, an gano matakai biyar daban-daban na crystal a cikin Ga2O3, gami da corundum (α), monoclinic (β), ƙarancin kashin baya (γ), cubic (δ) da matakan orthorhombic (ɛ). Matsalolin thermodynamic sune, tsari, γ, δ, α, ɛ, da β. Ya kamata a lura da cewa monoclinic β-Ga2O3 shine mafi kwanciyar hankali, musamman a yanayin zafi mai zafi, yayin da sauran matakan ke daidaitawa sama da yanayin ɗaki kuma suna canzawa zuwa lokacin β ƙarƙashin takamaiman yanayin thermal. Sabili da haka, haɓaka na'urori masu tushen β-Ga2O3 sun zama babban abin da aka fi mayar da hankali a fagen lantarki a cikin 'yan shekarun nan.
Tebura 1 Kwatanta wasu sigogin abu na semiconductor
An nuna tsarin crystal na monoclinicβ-Ga2O3 a cikin Teburin 1. Matsalolinsa na lattice sun hada da a = 12.21 Å, b = 3.04 Å, c = 5.8 Å, da β = 103.8 °. Tantanin tantanin halitta ya ƙunshi atom ɗin Ga(I) mai murɗaɗɗen daidaitawar tetrahedral da Ga(II) atom ɗin tare da daidaitawar octahedral. Akwai tsare-tsare daban-daban guda uku na atom ɗin oxygen a cikin tsararrun “ƙarƙasasshiyar cubic”, gami da haɗin gwiwar O(I) da O (II) masu daidaitawa guda biyu da kuma O(III) atom ɗin tetrahedrally. Haɗin waɗannan nau'ikan daidaitawar atomatik guda biyu yana haifar da anisotropy na β-Ga2O3 tare da kaddarorin musamman a cikin ilimin lissafi, lalata sinadarai, na'urorin gani da lantarki.
Hoto 1 Tsarin tsarin tsari na monoclinic β-Ga2O3 crystal
Daga ra'ayi na ka'idar band makamashi, mafi ƙarancin ƙimar rukunin gudanarwa na β-Ga2O3 an samo shi daga yanayin makamashi wanda ya dace da 4s0 matasan orbit na Ga atom. Bambancin makamashi tsakanin ƙaramin ƙima na band ɗin tafiyarwa da matakin makamashin injin (electron affinity energy) ana auna. ku 4 ev. Ana auna yawan ƙarfin lantarki mai inganci na β-Ga2O3 azaman 0.28-0.33 ni da ingantaccen ƙarfin lantarki. Koyaya, matsakaicin valence band yana nuna madaidaicin Ek mai zurfi tare da ƙananan lanƙwasa da ƙaƙƙarfan yanayi na O2p orbitals, yana nuna cewa ramukan suna cikin gida sosai. Waɗannan halayen suna haifar da babban ƙalubale don cimma nau'in doping na p-a cikin β-Ga2O3. Ko da za a iya samun nau'in doping na nau'in P, ramin μ ya kasance a matakin ƙasa kaɗan. 2. Girman girma gallium oxide guda crystal Ya zuwa yanzu, hanyar girma na β-Ga2O3 girma guda crystal substrate shi ne yafi crystal ja hanya, irin su Czochralski (CZ), gefen bakin-tsare bakin ciki ciyar hanya (Edge -Defined film-feed). , EFG), Bridgman (rtical ko a kwance Bridgman, HB ko VB) da kuma yankin iyo (yankin iyo, FZ) fasaha. Daga cikin dukkan hanyoyin, ana sa ran Czochralski da kuma hanyoyin ciyar da bakin ciki-fim-fim ɗin za su zama mafi kyawun hanyoyi don samar da adadin wafers na β-Ga 2O3 a nan gaba, saboda suna iya cimma babban ƙima da ƙarancin lahani. Har zuwa yanzu, Fasahar Novel Crystal ta Japan ta sami matrix na kasuwanci don haɓaka haɓakar β-Ga2O3.
1.1 Hanyar Czochralski
Ka'idar hanyar Czochralski ita ce an fara rufe nau'in nau'in iri, sa'an nan kuma an cire lu'ulu'u ɗaya a hankali daga narke. Hanyar Czochralski tana ƙara mahimmanci ga β-Ga2O3 saboda ƙimarta-tasiri, girman girman girman girmansa, da haɓakar ƙirar ƙira mai inganci. Duk da haka, saboda damuwa na thermal a lokacin babban zafin jiki na Ga2O3, ƙawancen lu'ulu'u guda ɗaya, kayan narke, da lalacewa ga Ir crucible zai faru. Wannan shi ne sakamakon wahalar samun ƙananan nau'in doping a cikin Ga2O3. Gabatar da adadin iskar oxygen da ya dace a cikin yanayin girma shine hanya ɗaya don magance wannan matsala. Ta hanyar ingantawa, 2-inch β-Ga2O3 mai inganci mai inganci tare da kewayon maida hankali na lantarki kyauta na 10 ^ 16 ~ 10 ^ 19 cm-3 da matsakaicin adadin wutar lantarki na 160 cm2 / Vs an samu nasarar girma ta hanyar Czochralski.
Hoto 2 Single crystal na β-Ga2O3 girma ta hanyar Czochralski
1.2 Hanyar ciyarwar fim da aka ayyana gefen
Hanyar ciyarwar fina-finai na bakin ciki da aka ƙayyade ana ɗaukarta a matsayin babban mai fafutuka don samar da kasuwancin manyan yanki Ga2O3 kayan kristal guda ɗaya. Ka'idar wannan hanya ita ce sanya narke a cikin wani nau'i tare da tsagewar capillary, kuma narke ya tashi zuwa ƙirar ta hanyar aikin capillary. A saman, fim ɗin bakin ciki ya fito kuma yana bazuwa a duk kwatance yayin da ake jawo shi zuwa crystallize ta hanyar kristal iri. Bugu da ƙari, ana iya sarrafa gefuna na saman mold don samar da lu'ulu'u a cikin flakes, tubes, ko kowane nau'i na geometry da ake so. Hanyar ciyar da fim ɗin bakin ciki da aka ƙayyade na Ga2O3 yana ba da saurin girma da manyan diamita. Hoto 3 yana nuna zane na β-Ga2O3 crystal guda ɗaya. Bugu da ƙari, dangane da girman girman, 2-inch da 4-inch β-Ga2O3 substrates tare da kyakkyawar nuna gaskiya da daidaituwa an yi ciniki, yayin da aka nuna alamar 6-inch a cikin bincike don kasuwanci na gaba. Kwanan nan, manyan madauwari guda-crystal kayan girma kuma sun zama samuwa tare da (-201) fuskantarwa. Bugu da ƙari, hanyar β-Ga2O3 da aka ƙayyade ta hanyar ciyar da fina-finai kuma tana haɓaka doping na abubuwan ƙarfe na canji, yin bincike da shirye-shiryen Ga2O3 mai yiwuwa.
Hoto 3 β-Ga2O3 lu'ulu'u guda ɗaya wanda aka girma ta hanyar ciyarwar fim da aka ayyana gefen
1.3 Hanyar Bridgeman
A cikin hanyar Bridgeman, an samar da lu'ulu'u a cikin ƙwanƙwasa wanda a hankali ya motsa ta hanyar yanayin zafi. Ana iya aiwatar da tsarin a cikin daidaitawa a kwance ko a tsaye, yawanci ta yin amfani da igiya mai juyawa. Yana da kyau a lura cewa wannan hanya na iya ko a'a amfani da tsaba crystal. Ma'aikatan Bridgman na gargajiya ba su da hangen nesa kai tsaye na narkewa da tafiyar matakai na girma kuma dole ne su sarrafa yanayin zafi tare da madaidaicin gaske. Hanyar Bridgman na tsaye ana amfani da ita don haɓakar β-Ga2O3 kuma an san shi da ikon girma a cikin yanayin iska. A lokacin tsarin girma na hanyar Bridgman a tsaye, jimlar asarar narke da crucible ana kiyaye shi ƙasa da 1%, yana ba da damar haɓaka manyan lu'ulu'u guda β-Ga2O3 tare da ƙarancin asara.
Hoto 4 Single crystal na β-Ga2O3 girma ta hanyar Bridgeman
1.4 Hanyar yanki mai iyo
Hanyar yankin da ke iyo yana magance matsalar gurɓataccen kristal ta abubuwan da ba za a iya gani ba kuma yana rage tsadar tsadar da ke da alaƙa da babban zafin jiki na infrared crucibles. A lokacin wannan tsari na haɓaka, ana iya dumama narke ta fitila maimakon tushen RF, don haka sauƙaƙe abubuwan buƙatun kayan haɓaka. Ko da yake siffa da kristal ingancin β-Ga2O3 girma ta hanyar iyo yankin hanya ba tukuna mafi kyau duka, wannan hanya yana buɗe sama da wata alƙawari hanya don girma high-tsarki β-Ga2O3 cikin kasafin kudin-friendly lu'ulu'u.
Hoto 5 β-Ga2O3 crystal guda daya girma ta hanyar yankin mai iyo.
Lokacin aikawa: Mayu-30-2024