Izithintelo zobugcisa kunye neempumelelo kwiShishini leSilicon Carbide (SiC)

I-Silicon carbide (SiC), njengesixhobo se-semiconductor sesizukulwana sesithathu, ifumana ingqwalasela enkulu ngenxa yeempawu zayo eziphezulu zomzimba kunye nezicelo ezithembisayo kwi-elektroniki ezinamandla aphezulu. Ngokungafaniyo ne-silicon (Si) okanye i-germanium (Ge) semiconductors zemveli, i-SiC ine-bandgap ebanzi, i-thermal conductivity ephezulu, intsimi yokuqhekeka okuphezulu, kunye nozinzo oluhle kakhulu lweekhemikhali. Ezi mpawu zenza i-SiC ibe yinto efanelekileyo kwizixhobo zamandla kwizithuthi zombane, iinkqubo zamandla ahlaziyekayo, unxibelelwano lwe-5G, kunye nezinye izicelo ezisebenzayo nezithembekileyo. Nangona kunjalo, nangona inamandla, ishishini le-SiC lijongene nemingeni yobuchwephesha enzulu eyenza imiqobo ebalulekileyo ekusetyenzisweni ngokubanzi.

1. I-SiC SubstrateUkukhula kwekristale kunye nokuveliswa kweWafer

Ukuveliswa kwee-substrates zeSiC sisiseko soshishino lweSiC kwaye simele umqobo ophezulu wobuchwephesha. I-SiC ayinakukhula ukusuka kwisigaba solwelo njenge-silicon ngenxa yendawo yayo yokunyibilika ephezulu kunye ne-crystal chemistry eyinkimbinkimbi. Endaweni yoko, indlela ephambili kukuthuthwa komphunga okwenziwa emzimbeni (i-PVT), okubandakanya ukuthuthwa kwe-silicon ephezulu kunye neempuphu zekhabhoni kubushushu obungaphezulu kwe-2000°C kwindawo elawulwayo. Inkqubo yokukhula ifuna ulawulo oluchanekileyo kwi-gradients yobushushu, uxinzelelo lwegesi, kunye ne-flow dynamics ukuvelisa iikristale ezikumgangatho ophezulu.

I-SiC inee-polytypes ezingaphezu kwama-200, kodwa zimbalwa kuphela ezifanelekileyo kwizicelo ze-semiconductor. Ukuqinisekisa i-polytype echanekileyo ngelixa kunciphisa iziphene ezifana nee-micropipes kunye nokususwa kwentambo kubalulekile, njengoko ezi ziphene zichaphazela kakhulu ukuthembeka kwesixhobo. Izinga lokukhula elicothayo, elidla ngokuba ngaphantsi kwe-2 mm ngeyure, liphumela kumaxesha okukhula kwekristale ukuya kuthi ga kwiveki kwibhola enye, xa kuthelekiswa neentsuku ezimbalwa kwiikristale zesilicon.

Emva kokukhula kwekristale, iinkqubo zokusika, ukugaya, ukupolisha, kunye nokucoca zinzima kakhulu ngenxa yobunzima beSiC, obulandela idayimani kuphela. La manyathelo kufuneka agcine umgangatho womphezulu ngelixa ephepha ukuqhekeka okuncinci, ukuqhekeka komphetho, kunye nomonakalo ongaphantsi komhlaba. Njengoko ububanzi be-wafer bukhula ukusuka kwi-intshi ezi-4 ukuya kwi-intshi ezi-6 okanye ezi-8, ukulawula uxinzelelo lobushushu kunye nokufikelela ekwandeni okungenaziphene kuya kuba nzima ngakumbi.

2. I-SiC Epitaxy: Ukulingana kweLayer kunye noLawulo lweDoping

Ukukhula kwe-epitaxial kwee-SiC layers kwi-substrates kubalulekile kuba ukusebenza kombane kwesixhobo kuxhomekeke ngqo kumgangatho wezi layers. I-Chemical vapor deposition (CVD) yindlela ebalaseleyo, evumela ulawulo oluchanekileyo kuhlobo lwe-doping (uhlobo lwe-n okanye uhlobo lwe-p) kunye nobukhulu be-layers. Njengoko ukulinganiswa kwe-voltage kusanda, ubukhulu be-epitaxial layers obufunekayo bunokunyuka ukusuka kwi-micrometer ezimbalwa ukuya kwi-tens okanye kwanamakhulu e-micrometers. Ukugcina ubukhulu obufanayo, ukumelana okuhlala kuhleli, kunye noxinano oluphantsi lwe-defect kuzo zonke ii-layers ezixineneyo kunzima kakhulu.

Izixhobo kunye neenkqubo ze-Epitaxy okwangoku zilawulwa ngababoneleli abambalwa behlabathi, nto leyo edala imiqobo yokungena ephezulu kubavelisi abatsha. Nokuba kukho ii-substrates ezikumgangatho ophezulu, ulawulo olubi lwe-epitaxial lunokubangela ukuba imveliso ingabi nkulu, ukuthembeka okuphantsi, kunye nokusebenza okungaphantsi komgangatho wesixhobo.

3. Ukwenziwa kwesixhobo: Iinkqubo ezichanekileyo kunye nokuhambelana kwezinto

Ukwenziwa kwezixhobo zeSiC kuzisa eminye imingeni. Iindlela zemveli zokusasazwa kwesilicon aziphumeleli ngenxa yokuba iSiC inyibilika kakhulu; kusetyenziswa ukufakelwa kwee-ion endaweni yoko. Kufuneka i-annealing yobushushu obuphezulu ukuze kusebenze ii-dopants, nto leyo ebeka emngciphekweni umonakalo we-crystal lattice okanye ukuwohloka komphezulu.

Ukwakhiwa kwee-contacts zesinyithi ezikumgangatho ophezulu yenye ingxaki ebalulekileyo. Ukumelana okuphantsi kokunxibelelana (<10⁻⁵ Ω·cm²) kubalulekile ekusebenzeni kakuhle kwezixhobo zamandla, kodwa ii-metals eziqhelekileyo ezifana ne-Ni okanye i-Al zinozinzo olulinganiselweyo lobushushu. Iinkqubo zokudibanisa i-metallization ziphucula uzinzo kodwa zonyusa ukumelana kokunxibelelana, nto leyo eyenza ukuba ukwenziwa kube nzima kakhulu.

IiSiC MOSFET nazo zineengxaki zojongano; ujongano lweSiC/SiO₂ luhlala lunemigibe emininzi, nto leyo ethintela ukuhamba kwetshaneli kunye nokuzinza kwevolthi yomgca. Isantya sokutshintsha ngokukhawuleza senza iingxaki zibe mandundu ngakumbi nge-parasitic capacitance kunye ne-inductance, nto leyo efuna uyilo olucokisekileyo lweesekethe zokuqhuba ii-gate kunye nezisombululo zokupakisha.

4. Ukupakishwa kunye nokuHlanganisa iiNkqubo

Izixhobo zamandla zeSiC zisebenza kwiivolthi eziphezulu kunye namaqondo obushushu kunee-silicon, nto leyo ebangela ukuba kusetyenziswe iindlela ezintsha zokupakisha. Iimodyuli zesiqhelo ezibotshelelwe ngocingo azanelanga ngenxa yemida yokusebenza kobushushu kunye nombane. Iindlela eziphambili zokupakisha, ezifana nee-wireless interconnects, ukupholisa okumacala amabini, kunye nokuhlanganiswa kwee-decoupling capacitors, ii-sensors, kunye nee-drive circuitry, ziyafuneka ukuze zisebenzise ngokupheleleyo amandla eSiC. Izixhobo ze-SiC zohlobo lwe-Trench ezine-unit density ephezulu ziya kuba zizinto eziqhelekileyo ngenxa yokumelana kwazo okuphantsi kokuqhuba, ukunciphisa amandla e-parasitic, kunye nokusebenza kakuhle kokutshintsha.

5. Ulwakhiwo lweendleko kunye neziphumo zoshishino

Ixabiso eliphezulu lezixhobo zeSiC ngokuyintloko libangelwa kukuveliswa kwezinto ze-substrate kunye ne-epitaxial, ezithi xa zizonke zibe malunga ne-70% yeendleko zokuvelisa zizonke. Nangona kukho iindleko eziphezulu, izixhobo zeSiC zibonelela ngeenzuzo zokusebenza ngaphezu kwe-silicon, ngakumbi kwiinkqubo ezisebenzayo kakhulu. Njengoko izikali kunye nemveliso yezixhobo ze-substrate kunye nezixhobo ziphucuka, ixabiso kulindeleke ukuba linciphe, okwenza izixhobo zeSiC zikhuphisane ngakumbi kwiimoto, amandla ahlaziyekayo, kunye nokusetyenziswa kwemizi-mveliso.

Isiphelo

Ishishini leSiC limele inqanaba elikhulu lobuchwepheshe kwizixhobo ze-semiconductor, kodwa ukwamkelwa kwalo kuthintelwe kukukhula okuntsonkothileyo kwekristale, ulawulo lwe-epitaxial layer, ukwenziwa kwezixhobo, kunye nemingeni yokupakisha. Ukoyisa le miqobo kufuna ulawulo oluchanekileyo lobushushu, ukucubungula izixhobo eziphambili, izakhiwo zezixhobo ezintsha, kunye nezisombululo ezintsha zokupakisha. Ukuqhubela phambili okuqhubekayo kwezi ndawo akuyi kunciphisa iindleko kuphela kwaye kuphucule isivuno kodwa kuya kuvula amandla apheleleyo eSiC kwizixhobo ze-elektroniki zamandla esizukulwana esilandelayo, izithuthi zombane, iinkqubo zamandla avuselelekayo, kunye nezicelo zonxibelelwano olusebenzisa amaxesha amaninzi.

Ikamva leshishini leSiC lilele ekudityanisweni kwezinto ezintsha, ukuveliswa ngokuchanekileyo, kunye noyilo lwezixhobo, nto leyo eqhuba utshintsho oluvela kwizisombululo ezisekelwe kwisilicon ukuya kwi-semiconductors ezisebenza kakuhle kakhulu nezithembekileyo kakhulu.