Matsalolin fasaha a cikin samar da ingantacciyar siliki carbide wafers tare da ingantaccen aiki sun haɗa da:
1) Tun da lu'ulu'u suna buƙatar girma a cikin yanayin yanayin zafi mai zafi sama da 2000 ° C, buƙatun kula da zafin jiki suna da girma sosai;
2) Tun da silicon carbide yana da fiye da 200 kristal Tsarin, amma kawai 'yan tsarin na guda-crystal silicon carbide ne da ake bukata semiconductor kayan, da silicon-to-carbon rabo, girma zafin jiki gradient, da crystal girma bukatar a sarrafa daidai a lokacin. da crystal girma tsari. Ma'auni kamar saurin gudu da iska;
3) A ƙarƙashin hanyar watsa lokacin tururi, fasahar fadada diamita na ci gaban kristal silicon carbide yana da matukar wahala;
4) Taurin silicon carbide yana kusa da na lu'u-lu'u, kuma yanke, niƙa, da dabarun gogewa suna da wahala.
SiC epitaxial wafers: yawanci ana kera su ta hanyar shigar da tururi (CVD). Dangane da nau'ikan doping daban-daban, an raba su zuwa nau'in n-type da p-type epitaxial wafers. Hantian Tiancheng na cikin gida da Dongguan Tianyu sun riga sun ba da wafers na SiC inch 4/6-inch. Don SiC epitaxy, yana da wuyar sarrafawa a cikin babban filin wutar lantarki, kuma ingancin SiC epitaxy yana da tasiri mai girma akan na'urorin SiC. Bugu da ƙari, manyan kamfanoni huɗu na masana'antu sun mamaye kayan aikin epitaxial: Axitron, LPE, TEL da Nuflare.
Silicon carbide epitaxialwafer yana nufin wafer siliki na siliki wanda fim ɗin kristal guda ɗaya (epitaxial Layer) tare da wasu buƙatu kuma daidai da kristal ɗin da aka girma akan asalin silin carbide na asali. Ci gaban Epitaxial galibi yana amfani da CVD (Chemical Vapor Deposition,) kayan aiki ko kayan aikin MBE (Molecular Beam Epitaxy). Tun da ana kera na'urorin silicon carbide kai tsaye a cikin Layer epitaxial, ingancin layin epitaxial kai tsaye yana shafar aiki da yawan amfanin na'urar. Yayin da ƙarfin ƙarfin ƙarfin ƙarfin na'urar ya ci gaba da karuwa, kauri na ma'auni na epitaxial Layer ya zama mai kauri kuma kulawa ya zama mafi wuya. Gabaɗaya, lokacin da ƙarfin lantarki ya kasance a kusa da 600V, kauri na epitaxial da ake bukata shine kimanin 6 microns; lokacin da ƙarfin lantarki ya kasance tsakanin 1200-1700V, kauri na epitaxial da ake buƙata ya kai 10-15 microns. Idan ƙarfin lantarki ya kai fiye da 10,000 volts, ana iya buƙatar kauri na epitaxial Layer fiye da 100 microns. Yayin da kauri na epitaxial Layer ke ci gaba da karuwa, yana daɗa wahala don sarrafa kauri da daidaituwar juriya da ƙarancin lahani.
Na'urorin SiC: Na duniya, 600 ~ 1700V SiC SBD da MOSFET sun kasance masana'antu. Samfuran na yau da kullun suna aiki a matakan ƙarfin lantarki da ke ƙasa da 1200V kuma da farko sun ɗauki TO marufi. Dangane da farashi, ana siyar da kayayyakin SiC a kasuwannin duniya a kusan sau 5-6 fiye da takwarorinsu na Si. Koyaya, farashin yana raguwa a cikin adadin shekara na 10%. tare da fadada kayan aiki na sama da kuma samar da na'urori a cikin shekaru 2-3 masu zuwa, samar da kasuwa zai karu, wanda zai haifar da ƙarin raguwar farashin. Ana sa ran lokacin da farashin ya kai sau 2-3 na samfuran Si, fa'idodin da aka samu ta hanyar rage farashin tsarin da ingantattun ayyuka za su motsa SiC a hankali don mamaye sararin kasuwa na na'urorin Si.
Marufi na al'ada ya dogara ne akan tushen siliki, yayin da kayan semiconductor na ƙarni na uku suna buƙatar sabon ƙira. Yin amfani da tsarin marufi na tushen silicon na al'ada don na'urorin wutar lantarki mai faɗi-bandgap na iya gabatar da sabbin batutuwa da ƙalubalen da suka danganci mitar, sarrafa zafi, da aminci. Na'urorin wutar lantarki na SiC sun fi kula da iyawar parasitic da inductance. Idan aka kwatanta da na'urorin Si, kwakwalwan wutar lantarki na SiC suna da saurin sauyawa da sauri, wanda zai iya haifar da overshoot, oscillation, ƙara yawan asarar sauyawa, har ma da na'urar rashin aiki. Bugu da ƙari, na'urorin wutar lantarki na SiC suna aiki a yanayin zafi mafi girma, suna buƙatar ƙarin dabarun sarrafa zafi.
An haɓaka nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan an haɓaka su a cikin fa'idar fakitin ikon marufi mai faɗi-bandgap. Marufi na tushen wutar lantarki na gargajiya na Si-ba ya dace. Don magance matsalolin manyan sigogin parasitic da ƙarancin ƙarancin zafi na marufi na kayan gargajiya na Si-tushen wutar lantarki, marufi na SiC Power module yana ɗaukar haɗin kai mara waya da fasahar sanyaya ta gefe biyu a cikin tsarinta, kuma yana ɗaukar kayan substrate tare da mafi kyawun thermal. conductivity, kuma yayi ƙoƙari ya haɗa capacitors decoupling, zafin jiki / na'urori masu auna sigina na yanzu, da kuma fitar da da'irori a cikin tsarin tsarin, da haɓaka nau'ikan marufi daban-daban na module. fasaha. Haka kuma, akwai manyan shingaye na fasaha don kera na'urar SiC kuma farashin samarwa yana da yawa.
Ana samar da na'urorin siliki na siliki ta hanyar ajiye yadudduka na epitaxial akan siliki carbide substrate ta CVD. Tsarin ya haɗa da tsaftacewa, iskar oxygen, photolithography, etching, cirewa na photoresist, ion implantation, sinadaran tururi na siliki nitride, gogewa, sputtering, da matakan sarrafawa na gaba don samar da tsarin na'urar akan SiC single crystal substrate. Manyan nau'ikan na'urorin wutar lantarki na SiC sun haɗa da SiC diodes, SiC transistor, da na'urorin wutar lantarki na SiC. Saboda dalilai kamar jinkirin saurin samar da kayan abu da ƙarancin yawan amfanin ƙasa, na'urorin silicon carbide suna da ƙarancin ƙira.
Bugu da ƙari, masana'anta na silicon carbide suna da wasu matsalolin fasaha:
1) Wajibi ne don haɓaka ƙayyadaddun tsari wanda ya dace da halayen silicon carbide kayan. Misali: SiC yana da babban wurin narkewa, wanda ke sa yaduwar zafi na gargajiya ba ta da tasiri. Wajibi ne a yi amfani da hanyar doping na ion implantation da daidaitattun sigogi kamar zazzabi, ƙimar dumama, tsawon lokaci, da kwararar gas; SiC ba ta da ƙarfi ga kaushi na sinadarai. Ya kamata a yi amfani da hanyoyi irin su busassun etching, kuma a inganta da haɓaka kayan rufe fuska, gaurayawan gas, sarrafa gangar jikin bangon gefe, ƙimar etching, ƙarancin bango, da sauransu.
2) Kera na'urorin lantarki na ƙarfe akan wafers na siliki carbide yana buƙatar juriyar lamba a ƙasa 10-5Ω2. Kayan lantarki da suka dace da buƙatun, Ni da Al, suna da ƙarancin yanayin zafi sama da 100°C, amma Al/Ni yana da mafi kyawun yanayin zafi. Ƙayyadaddun ƙayyadaddun tuntuɓar na / W/Au kayan haɗin lantarki yana da 10-3Ω2 mafi girma;
3) SiC yana da babban lalacewa, kuma taurin SiC shine na biyu kawai ga lu'u-lu'u, wanda ke gabatar da manyan buƙatu don yanke, niƙa, gogewa da sauran fasahohi.
Haka kuma, na'urorin wutar lantarki na silicon carbide sun fi wahalar kera su. Dangane da tsarin na'ura daban-daban, na'urorin wutar lantarki na silicon carbide za a iya raba su zuwa na'urori masu tsarawa da na'urori masu ramuka. Planar silicon carbide ikon na'urorin suna da ingantacciyar daidaituwar raka'a da tsari mai sauƙi na masana'anta, amma suna da haɗari ga tasirin JFET kuma suna da babban ƙarfin parasitic da juriya kan-jihar. Idan aka kwatanta da na'urori masu tsari, na'urorin wutar lantarki na silicon carbide suna da ƙananan daidaiton naúrar kuma suna da tsarin masana'anta mafi rikitarwa. Duk da haka, tsarin maɓalli yana da kyau don ƙara yawan adadin na'urar kuma ba shi da yuwuwar samar da tasirin JFET, wanda ke da amfani don magance matsalar motsi ta tashar. Yana da kyawawan kaddarorin kamar ƙananan kan-juriya, ƙaramin ƙarfi na parasitic, da ƙarancin amfani da kuzari. Yana da babban farashi da fa'idodin aiki kuma ya zama babban jagorar haɓaka na'urorin wutar lantarki na silicon carbide. Dangane da gidan yanar gizon hukuma na Rohm, tsarin ROHM Gen3 (tsarin Gen1 Trench) shine kawai kashi 75% na yanki guntu na Gen2 (Plannar2), kuma juriya na tsarin ROHM Gen3 yana raguwa da 50% ƙarƙashin girman guntu iri ɗaya.
Silicon carbide substrate, epitaxy, gaban-karshen, R&D kashe kudi da sauransu lissafin kudi 47%, 23%, 19%, 6% da 5% na masana'antu farashin silicon carbide na'urorin bi da bi.
A ƙarshe, za mu mai da hankali kan rushe shingaye na fasaha na substrates a cikin sarkar masana'antar silicon carbide.
Tsarin samar da siliki carbide substrates yayi kama da na tushen siliki, amma ya fi wahala.
Tsarin masana'anta na siliki carbide substrate gabaɗaya ya haɗa da haɓakar albarkatun ƙasa, haɓakar kristal, sarrafa ingot, yankan ingot, niƙa wafer, gogewa, tsaftacewa da sauran hanyoyin haɗin gwiwa.
Matsayin girma na crystal shine ainihin tsarin gaba ɗaya, kuma wannan matakin yana ƙayyade kaddarorin lantarki na silin carbide substrate.
Silicon carbide kayan suna da wahalar girma a cikin yanayin ruwa a ƙarƙashin yanayin al'ada. Hanyar haɓaka lokacin tururi sananne a kasuwa a yau yana da zafin girma sama da 2300 ° C kuma yana buƙatar daidaitaccen sarrafa zafin girma. Duk tsarin aiki yana da wuyar gani. Kuskure kadan zai haifar da gogewar samfur. A kwatanta, silicon kayan kawai bukatar 1600 ℃, wanda shi ne da yawa m. Shirya abubuwan siliki carbide shima yana fuskantar matsaloli kamar jinkirin haɓakar kristal da babban buƙatun sigar crystal. Ci gaban wafer na siliki yana ɗaukar kimanin kwanaki 7 zuwa 10, yayin da jan ƙarfe na siliki yana ɗaukar kwanaki 2 da rabi kawai. Haka kuma, silicon carbide wani abu ne wanda taurinsa ya kasance na biyu bayan lu'u-lu'u. Zai yi hasara mai yawa a lokacin yankan, niƙa, da gogewa, kuma ƙimar fitarwa shine kawai 60%.
Mun san cewa yanayin shine ƙara girman silin carbide substrates, yayin da girman ya ci gaba da karuwa, abubuwan da ake buƙata don fasahar fadada diamita sun zama mafi girma da girma. Yana buƙatar haɗuwa da abubuwa daban-daban na sarrafa fasaha don cimma ci gaban ci gaba na lu'ulu'u.
Lokacin aikawa: Mayu-22-2024