Inkqubo yokwenziwa kweSixhobo seSilicon Carbide (1)

Njengoko siyazi, kwintsimi ye-semiconductor, i-silicon eyodwa ye-crystal (Si) iyona nto isetyenziswa kakhulu kunye neyona nto inkulu kakhulu ye-semiconductor yezinto ezisisiseko kwihlabathi. Okwangoku, ngaphezu kwe-90% yeemveliso ze-semiconductor zenziwe kusetyenziswa izinto ezisekelwe kwi-silicon. Ngokunyuka kwemfuno yamandla aphezulu kunye nezixhobo eziphezulu ze-voltage kwindawo yamandla yanamhlanje, iimfuno ezingqongqo ziye zabekwa phambili kwiiparamitha eziphambili zezixhobo ze-semiconductor ezifana nobubanzi be-bandgap, ukophuka kwamandla ombane, izinga lokugcwala kwe-electron, kunye ne-thermal conductivity. Phantsi kwale meko, i-wide bandgap semiconductor imathiriyeli emelwe yii-silicon carbide(SiC) ziye zavela njengentandane yezicelo zoxinzelelo lwamandla aphezulu.

Njenge-semiconductor edibeneyo,i-silicon carbideinqabile kakhulu kwindalo kwaye ibonakala ngohlobo lweminerali moissanite. Okwangoku, phantse yonke i-silicon carbide ethengiswayo emhlabeni yenziwe ngobuchule. I-Silicon carbide ineenzuzo zobunzima obuphezulu, ukuhanjiswa okuphezulu kwe-thermal, uzinzo olufanelekileyo lwe-thermal, kunye nentsimi yombane ephezulu. Yimathiriyeli efanelekileyo yokwenza izixhobo ze-semiconductor eziphezulu ze-voltage kunye namandla aphezulu.

Ke, zenziwa njani izixhobo ze-silicon carbide power semiconductor?

Uthini umahluko phakathi kwenkqubo yokwenziwa kwesixhobo se-silicon carbide kunye nenkqubo yokwenziwa kwe-silicon yemveli? Ukuqala kolu shicilelo, “Izinto malungaIsixhobo seSilicon CarbideUkuvelisa” kuya kutyhila iimfihlo nganye nganye.

I

Inkqubo yokuhamba kokwenziwa kwesixhobo se-silicon carbide

Inkqubo yokwenziwa kwezixhobo ze-silicon carbide ngokubanzi zifana nezixhobo ezisekelwe kwi-silicon, ngokukodwa kubandakanywa i-photolithography, ukucoca, i-doping, i-etching, ukubunjwa kwefilimu, ukuncipha kunye nezinye iinkqubo. Abaninzi abavelisi bezixhobo zamandla banokuhlangabezana neemfuno zokwenziwa kwezixhobo ze-silicon carbide ngokuphucula imigca yabo yokuvelisa ngokusekelwe kwinkqubo yokuvelisa i-silicon. Nangona kunjalo, iipropathi ezikhethekileyo zezinto ze-silicon carbide zigqiba ukuba ezinye iinkqubo kwisixhobo sokwenza isixhobo kufuneka zithembele kwisixhobo esithile sophuhliso olukhethekileyo ukwenza izixhobo ze-silicon carbide zimelane nombane ophezulu kunye nokuphezulu kwangoku.

II

Intshayelelo kwiimodyuli zenkqubo ekhethekileyo ye-silicon carbide

Iimodyuli zenkqubo ekhethekileyo ye-silicon carbide ikakhulu zigubungela idoping yokutofa, ukwakheka kwesango, i-morphology etching, i-metallization, kunye neenkqubo zokubhitya.

(1) I-doping ye-injection: Ngenxa yamandla aphezulu e-carbon-silicon bond kwi-silicon carbide, ii-athomu zokungcola kunzima ukusabalalisa kwi-silicon carbide. Xa ulungiselela izixhobo ze-silicon carbide, i-doping ye-PN junctions inokufumaneka kuphela ngokufakelwa kwe-ion kwiqondo lokushisa eliphezulu.
I-doping idla ngokwenziwa ngee-ion zokungcola ezifana ne-boron kunye ne-phosphorus, kwaye ubunzulu be-doping buhlala bu-0.1μm ~ 3μm. Ukufakelwa kwe-ion ene-energy ephezulu kuya kutshabalalisa i-lattice structure yezinto ze-silicon carbide ngokwayo. Ubushushu obuphezulu be-annealing buyafuneka ukulungisa umonakalo weletisi owenziwe kukufakelwa kwe-ion kunye nokulawula ifuthe le-anneal kuburhabaxa bomphezulu. Iinkqubo ezingundoqo kukufakelwa kwe-ion yobushushu obuphezulu kunye nobushushu obuphezulu be-annealing.

Umzobo 1 Umzobo weSchematic of ion implantation kunye nefuthe lobushushu obuphezulu be-annealing

(2) Ukwakhiwa kwesakhiwo sesango: Umgangatho we-SiC / SiO2 interface inempembelelo enkulu ekufudukeni kwesiteshi kunye nokuthembeka kwesango le-MOSFET. Kuyimfuneko ukuphuhlisa i-oxide yesango elithile kunye neenkqubo ze-annealing emva kwe-oxidation ukuhlawulela iibhondi ezijingayo kwi-interface ye-SiC / SiO2 kunye ne-athomu ezikhethekileyo (ezifana ne-athomu ye-nitrogen) ukuhlangabezana neemfuno zokusebenza komgangatho ophezulu we-SiC / SiO2 ujongano kunye nomgangatho ophezulu. ukufuduka kwezixhobo. Iinkqubo ezingundoqo yisango le-oxide ye-high-temperature oxidation, i-LPCVD, kunye ne-PECVD.

Umzobo we-2 Umzobo weSchematic we-deposition yefilimu ye-oxide eqhelekileyo kunye ne-oxidation yobushushu obuphezulu

(3) I-Morphology etching: Izinto ze-silicon ze-carbide zi-inert kwii-solvents zemichiza, kwaye ulawulo oluchanekileyo lwe-morphology lunokufezekiswa kuphela ngeendlela zokucima okomileyo; imathiriyeli yemaski, ukhetho lwe-mask etching, igesi exubeneyo, ulawulo lwe-sidewall, isantya se-etching, uburhabaxa be-sidewall, njl.njl kufuneka ukuphuhliswa ngokweempawu ze-silicon carbide. Iinkqubo ezingundoqo kukufakwa kwefilimu ebhityileyo, ifotolithography, i-dielectric film corrosion, kunye neenkqubo zokomisa ezomileyo.

Umzobo 3 Umzobo weSchematic we-silicon carbide etching process

(4) I-Metallization: I-electrode yomthombo wesixhobo idinga isinyithi ukwenza uqhagamshelwano oluhle oluphantsi lwe-ohmic kunye ne-silicon carbide. Oku akufuneki kuphela ukulawula inkqubo yokubekwa kwesinyithi kunye nokulawula imeko yojongano lwe-metal-semiconductor contact, kodwa ifuna i-annealing ephezulu yokushisa ukunciphisa umqobo we-Schottky umqobo kunye nokufikelela kwi-metal-silicon carbide ohmic contact. Ezona nkqubo zingundoqo kukutshiza kwe-metal magnetron, ukuphuphuma komqadi we-electron, kunye nokufakwa kwe-thermal annealing.

Umzobo 4 Umzobo weSchematic we-magnetron sputtering umgaqo kunye nefuthe le-metallization

(5) Inkqubo yokunciphisa: I-silicon ye-carbide impahla ineempawu zobunzima obuphezulu, i-brittleness ephezulu kunye nokuqina kwe-fracture ephantsi. Inkqubo yayo yokugaya iyakwazi ukubangela ukuphuka kwe-brittle yezinto eziphathekayo, kubangela umonakalo kwi-wafer surface kunye ne-sub-surface. Iinkqubo ezintsha zokusila kufuneka ziphuhliswe ukuhlangabezana neemfuno zokwenziwa kwezixhobo ze-silicon carbide. Iinkqubo ezingundoqo ziyancipha iidiski zokugaya, ifilimu enamathele kunye ne-peelling, njl.

Umzobo 5 Umzobo weskimu sokusila/umgaqo wokubhitya