Ubunzima bobuchwephesha kwii-wafers ze-silicon carbide ezivelisa ngobuninzi ezisemgangathweni ophezulu ezisebenza kakuhle ziquka:
1) Ekubeni iikristale kufuneka zikhule kwindawo evalwe ngamaqondo obushushu aphezulu ngaphezu kwama-2000°C, iimfuno zolawulo lwamaqondo obushushu ziphezulu kakhulu;
2) Ekubeni i-silicon carbide inezakhiwo zekristale ezingaphezu kwama-200, kodwa zimbalwa izakhiwo ze-single-crystal silicon carbide eziyimfuneko kwizixhobo ze-semiconductor, umlinganiselo we-silicon-to-carbon, i-gradient yobushushu bokukhula, kunye nokukhula kwekristale kufuneka kulawulwe ngokuchanekileyo ngexesha lenkqubo yokukhula kwekristale. Iiparameter ezifana nesantya kunye noxinzelelo lokuhamba komoya;
3) Phantsi kwendlela yokudlulisa i-vapor phase, iteknoloji yokwandisa ububanzi bokukhula kwekristale ye-silicon carbide inzima kakhulu;
4) Ubunzima be-silicon carbide bufana nobedayimani, kwaye iindlela zokusika, ukugaya, kunye nokupolisha zinzima.
Ii-wafer ze-epitaxial ze-SiC: zihlala ziveliswa ngendlela ye-chemical vapor deposition (CVD). Ngokweentlobo ezahlukeneyo ze-doping, zahlulwe zibe zii-wafer ze-epitaxial ze-n-type kunye ne-p-type. I-Hantian Tiancheng yasekhaya kunye ne-Dongguan Tianyu sele zinokubonelela ngee-wafer ze-epitaxial ze-SiC ze-intshi ezi-4/6-intshi. Kwi-epitaxy ye-SiC, kunzima ukuyilawula kwicandelo le-high-voltage, kwaye umgangatho we-epitaxy ye-SiC unempembelelo enkulu kwizixhobo ze-SiC. Ngaphezu koko, izixhobo ze-epitaxial zilawulwa ziinkampani ezine eziphambili kushishino: i-Axitron, i-LPE, i-TEL kunye ne-Nuflare.
I-silicon carbide epitaxialI-wafer ibhekisa kwi-wafer ye-silicon carbide apho ifilimu enye yekristale (umaleko we-epitaxial) eneemfuno ezithile kwaye efana ne-substrate crystal ikhuliswa kwi-substrate ye-silicon carbide yokuqala. Ukukhula kwe-Epitaxial kusebenzisa kakhulu izixhobo ze-CVD (Chemical Vapor Deposition, ) okanye izixhobo ze-MBE (Molecular Beam Epitaxy). Ekubeni izixhobo ze-silicon carbide zenziwe ngokuthe ngqo kumaleko we-epitaxial, umgangatho womaleko we-epitaxial uchaphazela ngokuthe ngqo ukusebenza kunye nemveliso yesixhobo. Njengoko i-voltage imelana nokusebenza kwesixhobo iqhubeka nokwanda, ubukhulu bomaleko we-epitaxial ohambelanayo buba bukhulu kwaye ulawulo luba nzima ngakumbi. Ngokubanzi, xa i-voltage imalunga ne-600V, ubukhulu bomaleko we-epitaxial obufunekayo bumalunga ne-6 microns; xa i-voltage iphakathi kwe-1200-1700V, ubukhulu bomaleko we-epitaxial obufunekayo bufikelela kwi-10-15 microns. Ukuba i-voltage ifikelela ngaphezu kwe-10,000 volts, ubukhulu bomaleko we-epitaxial obungaphezulu kwe-100 microns bungafuneka. Njengoko ubukhulu beleya ye-epitaxial buqhubeka busanda, kuba nzima ngakumbi ukulawula ukufana kobukhulu kunye nokuchasana kunye noxinano lweziphene.
Izixhobo zeSiC: Kumazwe ngamazwe, i-600 ~ 1700V SiC SBD kunye neMOSFET ziye zaphuhliswa kwimizi-mveliso. Iimveliso eziphambili zisebenza kumanqanaba ombane angaphantsi kwe-1200V kwaye ngokuyintloko zisebenzisa ukupakisha kwe-TO. Ngokuphathelele amaxabiso, iimveliso zeSiC kwimarike yamazwe ngamazwe zixabisa malunga namaxesha ama-5-6 aphezulu kunezo zisebenza nazo zeSi. Nangona kunjalo, amaxabiso ayehla ngesantya sonyaka se-10%. ngokwandiswa kwezixhobo eziphezulu kunye nemveliso yezixhobo kwiminyaka emi-2-3 ezayo, ukunikezelwa kwemarike kuya kwanda, okukhokelela ekwehleni kwamaxabiso ngakumbi. Kulindeleke ukuba xa ixabiso lifikelela amaxesha ama-2-3 kuneemveliso zeSi, iingenelo eziziswa kukunciphisa iindleko zenkqubo kunye nokusebenza okuphuculweyo ziya kuqhuba iSiC kancinci kancinci ukuba ithathe indawo yemarike yezixhobo zeSi.
Ukupakisha kwendabuko kusekelwe kwi-substrates ezisekelwe kwi-silicon, ngelixa izixhobo ze-semiconductor zesizukulwana sesithathu zifuna uyilo olutsha ngokupheleleyo. Ukusebenzisa izakhiwo zokupakisha zendabuko ezisekelwe kwi-silicon kwizixhobo zamandla ezibanzi ze-bandgap kunokungenisa imiba emitsha kunye nemingeni enxulumene ne-frequency, ulawulo lobushushu, kunye nokuthembeka. Izixhobo zamandla ze-SiC zinobuthathaka ngakumbi kwi-parasitic capacitance kunye ne-inductance. Xa kuthelekiswa nezixhobo ze-Si, ii-power chips ze-SiC zinesantya sokutshintsha esikhawulezayo, esinokukhokelela ekuqhumeni kakhulu, ukushukuma, ukwanda kokulahleka kokutshintsha, kunye nokungasebenzi kakuhle kwezixhobo. Ukongeza, izixhobo zamandla ze-SiC zisebenza kumaqondo obushushu aphezulu, zifuna iindlela zolawulo lobushushu eziphambili.
Kuye kwaphuhliswa iintlobo ngeentlobo zezakhiwo ezahlukeneyo kwicandelo lokupakisha amandla e-semiconductor ebanzi. Ukupakisha kwemodyuli yamandla esekwe kwi-Si yendabuko akusafanelekanga. Ukuze kusonjululwe iingxaki zeeparamitha eziphezulu zeparasite kunye nokusebenza kakubi kokusasazwa kobushushu kokupakisha kwemodyuli yamandla esekwe kwi-Si yendabuko, ukupakisha kwemodyuli yamandla e-SiC kusebenzisa uqhagamshelo olungenazingcingo kunye netekhnoloji yokupholisa ecaleni kabini kwisakhiwo sayo, kwaye kwamkela nezixhobo ze-substrate ezine-conductivity engcono yobushushu, kwaye kwazanywa ukudibanisa ii-capacitors zokudibanisa, ii-sensors zobushushu/zangoku, kunye neesekethe zokuqhuba kwisakhiwo semodyuli, kwaye kwaphuhliswa iindlela ezahlukeneyo zobuchwepheshe bokupakisha iimodyuli. Ngaphezu koko, kukho imiqobo ephezulu yobugcisa kwimveliso yezixhobo ze-SiC kwaye iindleko zemveliso ziphezulu.
Izixhobo ze-silicon carbide ziveliswa ngokubeka iileya ze-epitaxial kwi-substrate ye-silicon carbide nge-CVD. Le nkqubo ibandakanya ukucoca, i-oxidation, i-photolithography, i-etching, i-stripping ye-photoresist, i-ion implantation, i-chemical vapor deposition ye-silicon nitride, i-polishing, i-sputtering, kunye namanyathelo okucubungula alandelayo ukwenza isakhiwo sesixhobo kwi-substrate ye-SiC single crystal. Iintlobo eziphambili zezixhobo zamandla ze-SiC ziquka ii-diode ze-SiC, ii-transistors ze-SiC, kunye neemodyuli zamandla ze-SiC. Ngenxa yezinto ezifana nesantya esicothayo sokuvelisa izinto kunye namazinga aphantsi okuvelisa, izixhobo ze-silicon carbide zineendleko eziphezulu zokuvelisa.
Ukongeza, ukwenziwa kwezixhobo ze-silicon carbide kuneengxaki ezithile zobugcisa:
1) Kuyimfuneko ukuphuhlisa inkqubo ethile ehambelana neempawu zezinto ze-silicon carbide. Umzekelo: I-SiC ineqondo eliphezulu lokunyibilika, okwenza ukusasazwa kobushushu bendabuko kungasebenzi. Kuyimfuneko ukusebenzisa indlela yokufakelwa kwe-ion kunye nokulawula ngokuchanekileyo iiparameter ezifana nobushushu, izinga lokufudumeza, ubude, kunye nokuhamba kwegesi; I-SiC ayisebenzi kwizinyibilikisi zeekhemikhali. Iindlela ezifana nokugrumba okomileyo kufuneka zisetyenziswe, kwaye izinto zemaski, imixube yegesi, ulawulo lwethambeka elisecaleni, izinga lokugrumba, uburhabaxa becala, njl. kufuneka ziphuculwe kwaye ziphuhliswe;
2) Ukwenziwa kwee-electrode zesinyithi kwii-wafers ze-silicon carbide kufuna ukumelana nokudibana okungaphantsi kwe-10-5Ω2. Izinto ze-electrode ezihlangabezana neemfuno, i-Ni kunye ne-Al, azinazinzo lobushushu oluphezulu kwe-100°C, kodwa i-Al/Ni inozinzo lobushushu olungcono. Ukumelana okuthe ngqo kokunxibelelana kwezinto ze-electrode ezidityanisiweyo ze-/W/Au kuphezulu nge-10-3Ω2;
3) I-SiC inobunzima obukhulu bokusika, kwaye ubulukhuni be-SiC bulandela idayimani, nto leyo ebeka phambili iimfuno eziphezulu zokusika, ukugaya, ukupolisha kunye nezinye iindlela zobuchwepheshe.
Ngaphezu koko, izixhobo zamandla ze-trench silicon carbide kunzima ukuzenza. Ngokwezakhiwo ezahlukeneyo zezixhobo, izixhobo zamandla ze-silicon carbide zinokwahlulwahlulwa zibe zizixhobo ze-planar kunye nezixhobo ze-trench. Izixhobo zamandla ze-planar silicon carbide zinokuhambelana okuhle kweyunithi kunye nenkqubo elula yokuvelisa, kodwa zinomphumo we-JFET kwaye zinamandla aphezulu e-parasite kunye nokumelana kwimeko. Xa kuthelekiswa nezixhobo ze-planar, izixhobo zamandla ze-trench silicon carbide zinokuhambelana okuphantsi kweyunithi kwaye zinenkqubo yokuvelisa enzima ngakumbi. Nangona kunjalo, ulwakhiwo lwe-trench lufanelekile ekwandiseni uxinano lweyunithi yesixhobo kwaye akunakwenzeka ukuba luvelise isiphumo se-JFET, esiluncedo ekusombululeni ingxaki yokuhamba kwesiteshi. Ineempawu ezintle ezifana nokuxhathisa okuncinci, amandla amancinci e-parasite, kunye nokusetyenziswa kwamandla okutshintshiselana okuphantsi. Inezibonelelo ezinkulu zeendleko kunye nokusebenza kwaye ibe yindlela ephambili yophuhliso lwezixhobo zamandla ze-silicon carbide. Ngokwewebhusayithi esemthethweni yeRohm, isakhiwo seROHM Gen3 (isakhiwo seGen1 Trench) simalunga ne-75% kuphela yendawo yetshiphu yeGen2 (Plannar2), kwaye ukumelana kwesakhiwo seROHM Gen3 kuncitshiswe ngama-50% phantsi kobukhulu obufanayo betshiphu.
Iindleko zeSilicon carbide substrate, epitaxy, front-end, R&D kunye nezinye zenza i-47%, 23%, 19%, 6% kunye ne-5% yeendleko zokwenziwa kwezixhobo zeSilicon carbide ngokwahlukeneyo.
Okokugqibela, siza kugxila ekuqhekezeni imiqobo yobugcisa yeziseko ezikwikhonkco leshishini le-silicon carbide.
Inkqubo yokuvelisa ii-substrates ze-silicon carbide ifana neyee-substrates ezisekelwe kwi-silicon, kodwa inzima ngakumbi.
Inkqubo yokuvelisa i-silicon carbide substrate ngokubanzi ibandakanya ukwenziwa kwezinto eziluhlaza, ukukhula kwekristale, ukucutshungulwa kwe-ingot, ukusika i-ingot, ukugaya i-wafer, ukupolisha, ukucoca kunye nezinye iikhonkco.
Isigaba sokukhula kwekristale sisisiseko senkqubo yonke, kwaye eli nyathelo limisela iipropati zombane ze-silicon carbide substrate.
Izinto ze-silicon carbide kunzima ukuzikhulisa kwisigaba solwelo phantsi kweemeko eziqhelekileyo. Indlela yokukhula kwesigaba somphunga edumileyo kwimarike namhlanje inobushushu bokukhula obungaphezulu kwama-2300°C kwaye ifuna ulawulo oluchanekileyo lobushushu bokukhula. Yonke inkqubo yokusebenza iphantse ibe nzima ukuyijonga. Impazamo encinci iya kukhokelela ekususweni kwemveliso. Xa kuthelekiswa, izinto ze-silicon zifuna kuphela i-1600℃, nto leyo iphantsi kakhulu. Ukulungiselela izinto ze-silicon carbide kukwajongene nobunzima obufana nokukhula kancinci kwekristale kunye neemfuno eziphezulu zesimo sekristale. Ukukhula kwe-silicon carbide wafer kuthatha malunga neentsuku ezi-7 ukuya kwezi-10, ngelixa ukutsala intonga ye-silicon kuthatha iintsuku ezi-2 ezinesiqingatha kuphela. Ngaphezu koko, i-silicon carbide yinto enobunzima bayo obulandela idayimani kuphela. Iya kulahlekelwa kakhulu ngexesha lokusika, ukugaya, kunye nokupolisha, kwaye umlinganiselo wemveliso yi-60% kuphela.
Siyazi ukuba umkhwa kukwandisa ubungakanani be-silicon carbide substrates, njengoko ubungakanani buqhubeka bukhula, iimfuno zobuchwepheshe bokwandisa ububanzi ziya zisanda. Kufuna indibaniselwano yezinto ezahlukeneyo zolawulo lobuchwephesha ukuze kufezekiswe ukukhula okuphindaphindayo kweekristale.
Ixesha leposi: Meyi-22-2024