Wide bandgap (WBG) semiconductors inomiririrwa nesilicon carbide (SiC) uye gallium nitride (GaN) yakagamuchira kutariswa kwakapararira. Vanhu vane tarisiro huru yetarisiro yekushandiswa kwesilicon carbide mumotokari dzemagetsi uye magidhi emagetsi, pamwe netarisiro yekushandiswa kwegallium nitride mukukurumidza kuchaja. Mumakore achangopfuura, tsvakiridzo paGa2O3, AlN uye zvemadhaimani zvakafambira mberi zvakanyanya, zvichiita kuti ultra-wide bandgap semiconductor zvinhu kuve kutarisisa. Pakati pazvo, gallium oxide (Ga2O3) iri kubuda ultra-wide-bandgap semiconductor material ine bhendi gap re4.8 eV, theoretical critical breakdown field simba rinenge 8 MV cm-1, saturation velocity inosvika 2E7cm s-1, uye yakakwirira yeBaliga yemhando ye3000, inogamuchira kutarisisa kwakapararira mumunda weiyo yakakwira voltage uye yakakwirira frequency. magetsi emagetsi.
1. Gallium oxide zvinhu maitiro
Ga2O3 ine gap hombe yebhendi (4.8 eV), inotarisirwa kuwana zvese zvakakwirira zvinomira nevoltage uye masimba emagetsi, uye inogona kuve neinogoneka yekuchinjika kwevoltage yakakura pakudzikira kwakaderera, zvichiita kuti vatarise kutsvagisa kwazvino. Pamusoro pezvo, Ga2O3 haingove neakanakisa zvinhu zvivakwa, asi zvakare inopa akasiyana-siyana anochinjika nyore n-mhando doping tekinoroji, pamwe neinodhura substrate kukura uye epitaxy tekinoroji. Parizvino, zvikamu zvishanu zvakasiyana zvekristaro zvakawanikwa muGa2O3, kusanganisira corundum (α), monoclinic (β), defective spinel (γ), cubic (δ) uye orthorhombic (ɛ) zvikamu. Thermodynamic stabilities ari, mukurongeka, γ, δ, α, ɛ, uye β. Zvakakosha kuziva kuti monoclinic β-Ga2O3 ndiyo yakanyanya kugadzikana, kunyanya pakupisa kwepamusoro, asi zvimwe zvikamu zvinogadzikana pamusoro pekushisa kwekamuri uye zvinowanzoshandura kuva β chikamu pasi pemamiriro chaiwo ekupisa. Nokudaro, kugadzirwa kwe-β-Ga2O3-based device kwave kunonyanya kukoshesa mumunda wemagetsi emagetsi mumakore achangopfuura.
Tafura 1 Kuenzanisa kweimwe semiconductor zvinhu paramita
Chimiro chekristasi chemonoclinicβ-Ga2O3 chinoratidzwa muTebhu 1. Mitsara yayo yelattice inosanganisira a = 12.21 Å, b = 3.04 Å, c = 5.8 Å, uye β = 103.8 °. Iyo unit cell ine Ga(I) maatomu ane akamonyoroka tetrahedral coordination uye Ga(II) maatomu ane octahedral coordination. Pane hurongwa hutatu hwakasiyana hwemaatomu eokisijeni mu”monyoroka cubic” array, kusanganisira maviri akabatanidzwa netriangularly coordinated O(I) and O(II) atomu uye one tetrahedally coordinated O(III) atomu. Iko kusanganiswa kweaya marudzi maviri ekubatana kweatomu kunotungamira kune anisotropy ye β-Ga2O3 ine yakakosha zvivakwa mufizikisi, kemikari corrosion, optics uye zvemagetsi.
Mufananidzo 1 Schematic structural diagram ye monoclinic β-Ga2O3 crystal
Kubva pamaonero eiyo simba bhendi dzidziso, kukosha kushoma kwebhendi conduction ye β-Ga2O3 inotorwa kubva kusimba resimba rinoenderana ne4s0 hybrid orbit yeGa atomu. Musiyano wesimba pakati pehushoma kukosha kwebhendi rekufambisa uye vacuum energy level (electron affinity energy) inopimwa. iri 4ev. Huremu hwemaerekitironi hunoshanda hweβ-Ga2O3 hunoyerwa se 0.28–0.33 me uye yakanaka yemagetsi conductivity. Nekudaro, iyo valence bhendi yepamusoro inoratidza isina kudzika Ek curve ine yakaderera curvature uye yakasimba yenzvimbo O2p orbitals, zvichiratidza kuti maburi acho akanyatso kugariswa. Aya maitiro anoisa dambudziko rakakura kuwana p-type doping mu β-Ga2O3. Kunyangwe kana P-mhando doping inogona kuwanikwa, gomba μ rinoramba riri padanho rakaderera. 2. Kukura kwekazhinji gallium oxide single crystal Kusvika ikozvino, nzira yekukura ye β-Ga2O3 yakawanda imwe crystal substrate inonyanya kudhonza nzira, yakadai seCzochralski (CZ), kumucheto-inotsanangurwa yakaonda firimu yekudyisa nzira (Edge -Defined film-fed , EFG), Bridgman (ritical or horizontal Bridgman, HB kana VB) nenzvimbo inoyangarara (inoyangarara) zone, FZ) tekinoroji. Pakati pese nzira, Czochralski uye kumucheto-inotsanangurwa yakaonda-firimu nzira dzekudyisa inotarisirwa kuve nzira dzakanyanya kuvimbisa dzekugadzirwa kwemazhinji β-Ga 2O3 wafers mune ramangwana, sezvo vanogona panguva imwe chete kuwana mavhoriyamu makuru uye yakaderera densities. Kusvika parizvino, Novel Crystal Technology yekuJapan yakaona matrix yekutengeserana yekunyungudutsa kukura β-Ga2O3.
1.1 Czochralski nzira
Nheyo yeCzochralski nzira ndeyokuti mhodzi yembeu inotanga kuvharwa, uye ipapo kristaro imwe chete inobudiswa zvishoma nezvishoma kubva pakunyunguduka. Iyo Czochralski nzira iri kuwedzera kukosha kune β-Ga2O3 nekuda kwekudhura kwayo, hukuru hukuru hwekugona, uye yakakwirira yekristaro mhando substrate kukura. Nekudaro, nekuda kwekushushikana kwekupisa panguva yekukura-kupisa kweGa2O3, kubuda kwekristaro imwe chete, kunyungudika zvinhu, uye kukuvadzwa kweIr crucible kuchaitika. Izvi mhedzisiro yekuomerwa kwekuwana yakaderera n-type doping muGa2O3. Kuunza huwandu hwakakodzera hweokisijeni mumhepo yekukura ndiyo imwe nzira yekugadzirisa dambudziko iri. Kuburikidza nekugadzirisa, yepamusoro-soro 2-inch β-Ga2O3 ine yemahara electron concentration range ye 10 ^ 16 ~ 10 ^ 19 cm-3 uye yakawanda electron density ye 160 cm2 / Vs yakabudirira kukura nenzira yeCzochralski.
Mufananidzo 2 Single crystal ye β-Ga2O3 inokura neCzochralski nzira
1.2 Edge-inotsanangurwa firimu yekudyisa nzira
Iyo yekumucheto-inotsanangurwa yakaonda firimu yekudyisa nzira inoonekwa seyo inotungamira mukwikwidzi wekutengesa kugadzirwa kwemahombe-nzvimbo Ga2O3 single crystal zvinhu. Nheyo yeiyi nzira ndeyekuisa iyo yakanyunguduka mu mold ine capillary slit, uye iyo yakanyunguduka inokwira kune mold kuburikidza necapillary action. Pamusoro, firimu rakatetepa rinoumba uye rinopararira kumativi ose richikurudzirwa kupenya nekristaro yembeu. Pamusoro pezvo, mipendero yekumusoro kwe mold inogona kudzorwa kugadzira makristasi mumaflakes, machubhu, kana chero inodiwa geometry. Iyo yekumucheto-inotsanangurwa yakaonda firimu yekudyisa nzira yeGa2O3 inopa kukurumidza kukura mazinga uye madhayamita makuru. Mufananidzo 3 unoratidza dhayagiramu ye β-Ga2O3 single crystal. Pamusoro pezvo, maererano nechiyero chehukuru, 2-inch uye 4-inch β-Ga2O3 substrates ine yakajeka yakajeka uye yakafanana yakave ichitengeswa, nepo 6-inch substrate inoratidzwa mukutsvaga kwekutengesa mune ramangwana. Munguva pfupi yapfuura, yakakura denderedzwa imwe-crystal yakawanda zvinhu zvakare yave kuwanikwa ine (-201) yekumisikidza. Pamusoro pezvo, iyo β-Ga2O3 yakatsanangurwa kumucheto-inotsanangurwa firimu nzira yekudyisa inosimudzirawo doping yezvinhu zvinoshandura simbi, zvichiita kuti kutsvagisa nekugadzirira kweGa2O3 kugoneke.
Mufananidzo 3 β-Ga2O3 crystal imwe chete inokura nemucheto-inotsanangurwa firimu yekudyisa nzira
1.3 Bridgeman nzira
Munzira yeBridgeman, makristasi anoumbwa mune crucible iyo inofambiswa zvishoma nezvishoma kuburikidza nekushisa gradient. Iyo nzira inogona kuitwa mune yakachinjika kana yakatwasuka yakatarisa, kazhinji uchishandisa crucible inotenderera. Zvakakosha kuziva kuti nzira iyi inogona kana kusashandisa mbeu dzekristaro. Traditional Bridgman operators inoshaya kuona kwakananga kwekunyunguduka uye kukura kwekristaro maitiro uye anofanirwa kudzora tembiricha nehupamhi hwepamusoro. Iyo yakatwasuka Bridgman nzira inonyanya kushandiswa pakukura kweβ-Ga2O3 uye inozivikanwa nekugona kwayo kukura munzvimbo yemhepo. Munguva ye vertical Bridgman nzira yekukura maitiro, iyo yose kurasikirwa kwehuwandu hwekunyunguduka uye crucible inochengetwa pazasi 1%, zvichiita kuti kukura kwehombe β-Ga2O3 makristasi ega asina kurasikirwa kudiki.
Mufananidzo 4 Single crystal ye β-Ga2O3 inokura neBridgeman nzira
1.4 Inoyangarara nzvimbo nzira
Iyo nzira inoyangarara yenzvimbo inogadzirisa dambudziko rekusvibiswa kwekristaro nezvinhu zvinorovera uye inoderedza mitengo yakakwira inoenderana nepamusoro tembiricha inodzivirira infrared crucibles. Munguva iyi yekukura maitiro, kunyungudika kunogona kupiswa nerambi kwete RF sosi, nekudaro kurerutsa zvinodiwa pakukura kwemidziyo. Kunyange zvazvo chimiro uye crystal quality ye β-Ga2O3 inokura nenzira inoyangarara yenzvimbo haisati yakwana, nzira iyi inovhura nzira inovimbisa yekukura yakakwirira-kuchena β-Ga2O3 kuita bhajeti-inoshamwaridzika makristasi ega.
Mufananidzo 5 β-Ga2O3 kristaro imwechete inokura nenzira inoyangarara nzvimbo.
Nguva yekutumira: May-30-2024