Isine, Indlela yokudlulisa umphunga obonakalayo
Indlela yokuthutha umphunga (PVT) ivela kwi-teknoloji ye-sublimation yesigaba somphunga eyenziwe nguLely ngo-1955. I-powder ye-SiC ifakwe kwityhubhu yegraphite kwaye ishushu kwiqondo lokushisa eliphezulu ukubola kunye ne-sublimate ye-SiC powder, kwaye ityhubhu yegraphite ipholile. Emva kokubola kwe-powder ye-SiC, iinqununu zesigaba somphunga zifakwe kwaye zifakwe kwiikristale ze-SiC ezijikeleze ityhubhu yegraphite. Nangona le ndlela inzima ukufumana ubungakanani obukhulu be-SiC iikristale enye, kunye nenkqubo yokubeka kwityhubhu yegraphite kunzima ukuyilawula, inika iingcamango kubaphandi abalandelayo.
Ym Terairov et al. eRashiya yazisa ingcamango yeekristale zembewu kwesi siseko, kwaye yasombulula ingxaki ye-crystal shape engalawulekiyo kunye nesikhundla se-nucleation ye-crystals ye-SiC. Abaphandi abalandelayo baqhubeka nokuphucula kwaye ekugqibeleni baphuhlisa indlela yokuthutha igesi yegesi (PVT) kwindlela yokusetyenziswa kwezoshishino namhlanje.
Njengeyona ndlela yokuqala yokukhula kwekristale yeSiC, indlela yokudlulisa umphunga womzimba yeyona ndlela iphambili yokukhula kwekristale yeSiC. Xa kuthelekiswa nezinye iindlela, indlela ineemfuno eziphantsi zezixhobo zokukhula, inkqubo yokukhula elula, ukulawulwa okuqinileyo, uphuhliso olucokisekileyo kunye nophando, kwaye ifezekise isicelo soshishino. Ukwakhiwa kwekristale ekhulile yindlela yangoku ye-PVT eqhelekileyo iboniswe kumzobo.
Imimandla yokushisa ye-axial kunye ne-radial inokulawulwa ngokulawula iimeko zangaphandle zokugquma i-thermal ye-graphite crucible. I-powder ye-SiC ifakwe phantsi kwe-graphite crucible kunye nokushisa okuphezulu, kwaye i-crystal yembewu ye-SiC igxininiswe phezulu kwi-graphite crucible kunye neqondo lokushisa eliphantsi. Umgama phakathi komgubo kunye nembewu ulawulwa ngokubanzi ukuba ube ngamashumi eemilimitha ukuphepha ukudibanisa phakathi kwekristale enye ekhulayo kunye nomgubo. Iqondo lobushushu lidla ngokuba kuluhlu lwe-15-35℃/cm. Igesi ye-inert ye-50-5000 Pa igcinwe kwisithando somlilo ukwandisa i-convection. Ngale ndlela, emva kokuba i-powder ye-SiC ifudunyezwe kwi-2000-2500 ℃ ngokufudumeza kwe-induction, i-powder ye-SiC iya kuthotywa kwaye ibole ibe yi-Si, i-Si2C, i-SiC2 kunye nezinye izinto zomphunga, kwaye zithuthelwe ekupheleni kwembewu nge-convection yegesi, kunye Ikristale yeSiC ikhazimliswe kwikristale yembewu ukufezekisa ukukhula kwekristale enye. Izinga layo lokukhula eliqhelekileyo li-0.1-2mm / h.
Inkqubo ye-PVT igxile kulawulo lobushushu bokukhula, iqondo lobushushu, iqondo lobushushu, umphezulu wokukhula, isithuba somphezulu wezinto eziphathekayo kunye noxinzelelo lokukhula, inzuzo yalo kukuba inkqubo yalo ikhulile, izinto eziluhlaza kulula ukuvelisa, ixabiso liphantsi, kodwa inkqubo yokukhula Indlela ye-PVT inzima ukuyiqwalasela, izinga lokukhula kwe-crystal ye-0.2-0.4mm / h, kunzima ukukhula iikristali ezinobunzima obukhulu (> 50mm). Emva kwamashumi eminyaka yemizamo eqhubekayo, imarike yangoku yee-wafers ze-SiC substrate ezikhuliswe yindlela ye-PVT ibe nkulu kakhulu, kwaye imveliso yonyaka ye-SiC substrate wafers inokufikelela kumakhulu amawaka ama-wafers, kwaye ubukhulu bayo buguquka ngokuthe ngcembe ukusuka kwi-intshi ezi-4 ukuya kwi-intshi ezi-6. , kwaye iphuhlise i-8 intshi yeesampuli ze-SiC substrate.
Isihlanu,Ubushushu obuphezulu bekhemikhali indlela yokubeka umphunga
Ubushushu obuphezulu beMicimbi yoMphunga (HTCVD) yindlela ephuculweyo esekwe kwiChemical Vapor Deposition (CVD). Indlela yaqala ukucetywa kwi-1995 nguKordina et al., IYunivesithi yaseLinkoping, eSweden.
Umzobo wokukhula uboniswa kumzobo:
Imimandla yokushisa ye-axial kunye ne-radial inokulawulwa ngokulawula iimeko zangaphandle zokugquma i-thermal ye-graphite crucible. I-powder ye-SiC ifakwe phantsi kwe-graphite crucible kunye nokushisa okuphezulu, kwaye i-crystal yembewu ye-SiC igxininiswe phezulu kwi-graphite crucible kunye neqondo lokushisa eliphantsi. Umgama phakathi komgubo kunye nembewu ulawulwa ngokubanzi ukuba ube ngamashumi eemilimitha ukuphepha ukudibanisa phakathi kwekristale enye ekhulayo kunye nomgubo. Iqondo lobushushu lidla ngokuba kuluhlu lwe-15-35℃/cm. Igesi ye-inert ye-50-5000 Pa igcinwe kwisithando somlilo ukwandisa i-convection. Ngale ndlela, emva kokuba i-powder ye-SiC ifudunyezwe kwi-2000-2500 ℃ ngokufudumeza kwe-induction, i-powder ye-SiC iya kuthotywa kwaye ibole ibe yi-Si, i-Si2C, i-SiC2 kunye nezinye izinto zomphunga, kwaye zithuthelwe ekupheleni kwembewu nge-convection yegesi, kunye Ikristale yeSiC ikhazimliswe kwikristale yembewu ukufezekisa ukukhula kwekristale enye. Izinga layo lokukhula eliqhelekileyo li-0.1-2mm / h.
Inkqubo ye-PVT igxile kulawulo lobushushu bokukhula, iqondo lobushushu, iqondo lobushushu, umphezulu wokukhula, isithuba somphezulu wezinto eziphathekayo kunye noxinzelelo lokukhula, inzuzo yalo kukuba inkqubo yalo ikhulile, izinto eziluhlaza kulula ukuvelisa, ixabiso liphantsi, kodwa inkqubo yokukhula Indlela ye-PVT inzima ukuyiqwalasela, izinga lokukhula kwe-crystal ye-0.2-0.4mm / h, kunzima ukukhula iikristali ezinobunzima obukhulu (> 50mm). Emva kwamashumi eminyaka yemizamo eqhubekayo, imarike yangoku yee-wafers ze-SiC substrate ezikhuliswe yindlela ye-PVT ibe nkulu kakhulu, kwaye imveliso yonyaka ye-SiC substrate wafers inokufikelela kumakhulu amawaka ama-wafers, kwaye ubukhulu bayo buguquka ngokuthe ngcembe ukusuka kwi-intshi ezi-4 ukuya kwi-intshi ezi-6. , kwaye iphuhlise i-8 intshi yeesampuli ze-SiC substrate.
Isihlanu,Ubushushu obuphezulu bekhemikhali indlela yokubeka umphunga
Ubushushu obuphezulu beMicimbi yoMphunga (HTCVD) yindlela ephuculweyo esekwe kwiChemical Vapor Deposition (CVD). Indlela yaqala ukucetywa kwi-1995 nguKordina et al., IYunivesithi yaseLinkoping, eSweden.
Umzobo wokukhula uboniswa kumzobo:
Xa ikristale ye-SiC ikhuliswa ngendlela yesigaba solwelo, ubushushu kunye nokuhanjiswa kwe-convection ngaphakathi kwesisombululo esincedisayo kuboniswa kumzobo:
Ingabonwa ukuba iqondo lokushisa elikufutshane nodonga lwe-crucible kwisisombululo sokuncedisa liphezulu, ngelixa izinga lokushisa kwi-crystal yembewu liphantsi. Ngethuba lenkqubo yokukhula, i-graphite crucible inikeza umthombo we-C wokukhula kwekristale. Ngenxa yokuba iqondo lokushisa eludongeni lwe-crucible liphezulu, i-solubility ye-C inkulu, kwaye isantya sokuchithwa ngokukhawuleza, isixa esikhulu se-C siya kuchithwa eludongeni lwe-crucible ukwenza isisombululo esigcweleyo se-C. Ezi zisombululo ezinobungakanani obukhulu. ye-C echithwe iya kuthuthelwa kwindawo engezantsi yeekristale zembewu nge-convection ngaphakathi kwesisombululo sokuncedisa. Ngenxa yobushushu obuphantsi bembewu ye-crystal end, i-solubility ye-C ehambelanayo iyancipha ngokuhambelanayo, kwaye isisombululo sokuqala se-C-saturated siba sisisombululo esiphezulu se-C emva kokuba sidluliselwe ekupheleni kweqondo lokushisa eliphantsi phantsi kwalo mqathango. I-Suprataturated C kwisisombululo esidibene ne-Si kwisisombululo esincedisayo sinokukhula i-SiC crystal epitaxial kwi-crystal yembewu. Xa i-superforated inxalenye ye-C ikhupha ngaphandle, isisombululo sibuyela ekupheleni kobushushu obuphezulu bodonga lwe-crucible kunye ne-convection, kwaye ichithe i-C kwakhona ukwenza isisombululo esigcweleyo.
Yonke inkqubo iphinda, kwaye i-crystal ye-SiC ikhula. Kwinkqubo yokukhula kwesigaba solwelo, ukuchithwa kunye nemvula ye-C kwisisombululo sisalathiso esibaluleke kakhulu senkqubela phambili yokukhula. Ukuze kuqinisekiswe ukukhula kwe-crystal okuzinzile, kuyimfuneko ukugcina ukulingana phakathi kokuchithwa kwe-C kwindonga ye-crucible kunye nemvula ekupheleni kwembewu. Ukuba ukuchithwa kwe-C kukhulu kunemvula ye-C, ngoko i-C kwi-crystal iphuculwa ngokuthe ngcembe, kwaye i-nucleation ezenzekelayo ye-SiC iya kwenzeka. Ukuba ukuchithwa kweC kungaphantsi kwemvula yeC, ukukhula kwekristale kuya kuba nzima ukuphumeza ngenxa yokungabikho kwe-solute.
Ngexesha elifanayo, ukuthuthwa kwe-C nge-convection nako kuchaphazela ukunikezelwa kwe-C ngexesha lokukhula. Ukuze kukhule iikristale ze-SiC ezinomgangatho wekristale ngokwaneleyo kunye nobukhulu obaneleyo, kuyafuneka ukuba kuqinisekiswe ukulungelelana kwezi zinto zintathu zingasentla, okwandisa kakhulu ubunzima bokukhula kwesigaba solwelo seSiC. Nangona kunjalo, ngokuphuculwa kancinci kunye nokuphuculwa kweethiyori ezinxulumeneyo kunye netekhnoloji, izibonelelo zokukhula kwesigaba solwelo kwiikristale ze-SiC ziya kubonisa ngokuthe ngcembe.
Okwangoku, ukukhula kwesigaba solwelo se-2-intshi ye-SiC crystals kunokufezekiswa eJapan, kwaye ukukhula kwesigaba solwelo se-4-intshi yeekristale kuyaphuhliswa. Okwangoku, uphando lwasekhaya olufanelekileyo aluzange lubone iziphumo ezilungileyo, kwaye kuyimfuneko ukulandelela umsebenzi ofanelekileyo wophando.
Isixhenxe, Iimpawu zomzimba kunye neekhemikhali zeekristali zeSiC
(1) Iimpawu zoomatshini: Iikristale ze-SiC zinobunzima obuphezulu kakhulu kunye nokungagugi kakuhle. Ubunzima bayo be-Mohs buphakathi kwe-9.2 kunye ne-9.3, kwaye ubunzima bayo be-Krit buphakathi kwe-2900 kunye ne-3100Kg / mm2, okwesibini kuphela kwiikristale zedayimane phakathi kwezinto ezifunyenweyo. Ngenxa yeempawu ezibalaseleyo zoomatshini beSiC, i-powder SiC isetyenziswa rhoqo kwishishini lokusika okanye lokusila, kunye nemfuno yonyaka ukuya kuthi ga kwizigidi zeetoni. Ingubo ekwazi ukumelana nokunxiba kwezinye izinto zokusebenza ziya kusebenzisa i-SiC coating, umzekelo, i-coating engagugiyo kwezinye iinqanawa zemfazwe yenziwe nge-SiC coating.
(2) Iimpawu ze-Thermal: i-thermal conductivity ye-SiC inokufikelela kwi-3-5 W / cm·K, eyi-3 ngamaxesha e-semiconductor yendabuko uSi kunye namaxesha angama-8 e-GaAs. Ukuveliswa kobushushu kwesixhobo esilungiselelwe yi-SiC kunokuqhutyelwa ngokukhawuleza, ngoko ke iimfuno zeemeko zokutshatyalaliswa kobushushu zesixhobo se-SiC zikhululekile, kwaye zilungele ukulungiswa kwezixhobo eziphezulu zamandla. I-SiC ineempawu ezizinzileyo ze-thermodynamic. Ngaphantsi kweemeko eziqhelekileyo zoxinzelelo, i-SiC iya kuchithwa ngokuthe ngqo ibe ngumphunga oqukethe i-Si kunye ne-C phezulu.
(3) Iimpawu zeMichiza: I-SiC ineekhemikhali ezizinzile, ukumelana nokugqwesa okulungileyo, kwaye ayifuni nayiphi na i-asidi eyaziwayo kwiqondo lokushisa. I-SiC ebekwe emoyeni ixesha elide iya kuthi ngokuthe chu yenze umaleko obhityileyo we-SiO2 exineneyo, ithintele ukusabela okungaphezulu kwe-oxidation. Xa iqondo lobushushu linyuka ukuya kuthi ga kwi-1700℃, umaleko obhityileyo weSiO2 uyanyibilika kwaye oxidize ngokukhawuleza. I-SiC inokusabela ngokucothayo kwe-oxidation kunye ne-oxidants etyhidiweyo okanye iziseko, kwaye ii-wafers ze-SiC zihlala zigqwesa kwi-KOH etyhidiweyo kunye ne-Na2O2 ukubonisa ukuchithwa kwiikristale ze-SiC..
(4) Iimpawu zombane: I-SiC njengommeli wezinto ezimele i-bandgap semiconductors ebanzi, i-6H-SiC kunye ne-4H-SiC ububanzi be-bandgap yi-3.0 eV kunye ne-3.2 eV ngokulandelanayo, okuyi-3 amaxesha e-Si kunye ne-2 amaxesha e-GaAs. Izixhobo zeSemi-conductor ezenziwe nge-SiC zinokuvuza okuncinci kwangoku kunye nendawo enkulu yokutshatyalaliswa kombane, ngoko i-SiC ithathwa njengeyona nto ifanelekileyo kwizixhobo zamandla aphezulu. Ukushukuma kwe-electron egcweleyo ye-SiC iphinda-phindwe ka-2 ngaphezu kwe-Si, kwaye ineenzuzo ezicacileyo ekulungiseleleni izixhobo eziphezulu ze-frequency. Iikristale ze-P-uhlobo lwe-SiC okanye i-N-uhlobo lwe-SiC crystals inokufumaneka ngokufaka i-athomu yokungcola kwiikristale. Okwangoku, iikristale ze-P-uhlobo lwe-SiC zilawulwa ikakhulu yi-Al, B, Be, O, Ga, Sc kunye nezinye ii-athomu, kunye nohlobo lwe-N-uhlobo lwe-sic crystals lulawulwa kakhulu yi-athomu ye-N. Umahluko wokugxilwa kwe-doping kunye nohlobo luya kuba nefuthe elikhulu kwizinto eziphathekayo kunye neekhemikhali ze-SiC. Ngelo xesha, umthwali wamahhala unokubethelwa kwinqanaba elinzulu le-doping efana ne-V, i-resistivity inokunyuswa, kwaye i-crystal ye-SiC ye-semi-insulating inokufumaneka.
5 I-crystals ye-doped ye-SiC ibonisa imibala eyahlukeneyo ngenxa yeempawu zabo ezahlukeneyo, umzekelo, i-6H-SiC iluhlaza emva kwe-doping N; I-4H-SiC imdaka. I-15R-SiC ityheli. Ifakwe nge-Al, i-4H-SiC ibonakala iluhlaza okwesibhakabhaka. Yindlela ecacileyo yokwahlula uhlobo lwekristale yeSiC ngokujonga umahluko wombala. Ngophando oluqhubekayo kwiinkalo ezinxulumene ne-SiC kwiminyaka engama-20 edlulileyo, ukuphumelela okukhulu kuye kwenziwa kwiiteknoloji ezinxulumene.
Isibhozo,Intshayelelo yobume bophuhliso lweSiC
Okwangoku, ishishini le-SiC liye lakhula ngokugqibelele, ukusuka kwii-wafers ze-substrate, ii-wafers ze-epitaxial ukuya kwimveliso yesixhobo, ukupakishwa, lonke ikhonkco lemizi-mveliso likhulile, kwaye linokubonelela ngeemveliso ezinxulumene ne-SiC kwimarike.
I-Cree yinkokeli kushishino lokukhula kwekristale ye-SiC enesikhundla esiphambili kuzo zombini ubungakanani kunye nomgangatho we-SiC substrate wafers. Ngoku iCree ivelisa iitshiphusi ze-SiC substrate ezingama-300,000 ngonyaka, ezibalelwa ngaphezulu kwe-80% yothutho lwehlabathi.
NgoSeptemba ka-2019, iCree yabhengeza ukuba iza kwakha indawo entsha eNew York State, eMelika, eya kusebenzisa itekhnoloji ephezulu kakhulu ukukhulisa amandla angama-200 mm ubukhulu kunye ne-RF SiC substrate wafers, ebonisa ukuba itekhnoloji yayo yokulungiselela imathiriyeli eyi-200 mm yeSiC sele ikhona. uqole ngakumbi.
Okwangoku, iimveliso eziphambili ze-SiC substrate chips kwimarike ikakhulu ziyi-4H-SiC kunye ne-6H-SiC eqhubayo kunye neentlobo ze-semi-insulated ze-2-6 intshi.
Ngo-Okthobha ka-2015, uCree waba ngowokuqala ukuphehlelela ii-200 mm ze-SiC substrate wafers zohlobo lwe-N kunye ne-LED, ephawula ukuqala kwee-8-intshi ze-SiC substrate wafers ukuya kwimarike.
Kwi-2016, uRomm waqala ukuxhasa iqela le-Venturi kwaye wayengowokuqala ukusebenzisa i-IGBT + SiC SBD indibaniselwano emotweni ukuze ithathe indawo yesisombululo se-IGBT + Si FRD kwi-inverter yendabuko ye-200 kW. Emva kokuphuculwa, ubunzima be-inverter buncitshiswe nge-2 kg kwaye ubukhulu buyancipha nge-19% ngelixa kugcinwa amandla afanayo.
Kwi-2017, emva kokwamkelwa okungaphezulu kwe-SiC MOS + SiC SBD, kungekhona nje ubunzima obuncitshisiweyo nge-6 kg, ubukhulu buncitshiswe ngama-43%, kwaye amandla ombane aphinde anyuke ukusuka kwi-200 kW ukuya kwi-220 kW.
Emva kokuba uTesla amkele izixhobo ezisekelwe kwi-SIC kwii-inverters eziphambili ze-Model 3 yeemveliso ngo-2018, isiphumo sokubonisa sandiswa ngokukhawuleza, okwenza ukuba imarike yeemoto ze-xEV kungekudala ibe ngumthombo wolonwabo kwimarike ye-SiC. Ngokusetyenziswa okuyimpumelelo kweSiC, ixabiso layo lemveliso enxulumeneyo lemarike nalo linyuke ngokukhawuleza.
Isithoba,Isiphelo:
Ngophuculo oluqhubekayo lobugcisa be-SiC obunxulumene noshishino, isivuno kunye nokuthembeka kwayo kuya kuphuculwa ngakumbi, ixabiso lezixhobo ze-SiC liya kuncitshiswa, kwaye ukukhuphisana kwemarike ye-SiC kuya kubonakala ngakumbi. Kwixesha elizayo, izixhobo ze-SiC ziya kusetyenziswa ngokubanzi kwiinkalo ezahlukeneyo ezifana neemoto, unxibelelwano, iigridi zamandla, kunye nothutho, kwaye imarike yemveliso iya kuba banzi, kwaye ubungakanani bentengiso buya kwandiswa ngakumbi, bube yinkxaso ebalulekileyo kuzwelonke. uqoqosho.
Ixesha lokuposa: Jan-25-2024