A halin yanzu, masana'antar SiC tana canzawa daga inci 150 (inci 6) zuwa inci 200 (inci 8). Domin biyan buƙatar gaggawa ta manyan wafers na SiC homoepitaxial masu girma da inganci a masana'antar, 150mm da 200mm.Wafers ɗin homoepitaxial 4H-SiCAn shirya su cikin nasara a kan substrates na gida ta amfani da kayan aikin girma na epitaxial SiC 200mm wanda aka haɓaka kai tsaye. An ƙirƙiri tsarin homoepitaxial wanda ya dace da 150mm da 200mm, wanda ƙimar girma na epitaxial zai iya zama sama da 60um/h. Yayin da yake haɗuwa da epitaxy mai sauri, ingancin epitaxial wafer yana da kyau kwarai da gaske. Daidaiton kauri na 150 mm da 200 mmWafers na epitaxial na SiCAna iya sarrafa shi cikin 1.5%, daidaiton yawan abu bai wuce 3% ba, yawan lahani mai mutuwa bai wuce barbashi 0.3/cm2 ba, kuma matsakaicin tushen ƙazanta na saman epitaxial Ra bai wuce 0.15nm ba, kuma duk alamun aiwatarwa na asali suna cikin matakin ci gaba na masana'antar.
Silicon Carbide (SiC)yana ɗaya daga cikin wakilan kayan semiconductor na ƙarni na uku. Yana da halaye na ƙarfin filin fashewa mai yawa, kyakkyawan yanayin zafi, babban saurin juyewar electron, da juriya mai ƙarfi ga radiation. Ya faɗaɗa ƙarfin sarrafa makamashi na na'urorin wutar lantarki sosai kuma yana iya biyan buƙatun sabis na kayan lantarki na zamani na gaba don na'urori masu ƙarfi, ƙaramin girma, babban zafin jiki, babban radiation da sauran yanayi masu tsauri. Yana iya rage sarari, rage amfani da wutar lantarki da rage buƙatun sanyaya. Ya kawo canje-canje masu sauyi ga sabbin motocin makamashi, jigilar layin dogo, grids masu wayo da sauran fannoni. Saboda haka, an gane semiconductors na silicon carbide a matsayin kayan da suka dace waɗanda za su jagoranci ƙarni na gaba na na'urorin lantarki masu ƙarfi. A cikin 'yan shekarun nan, godiya ga goyon bayan manufofin ƙasa don haɓaka masana'antar semiconductor na ƙarni na uku, an kammala bincike da haɓakawa da gina tsarin masana'antar na'urorin SiC na 150 mm a China, kuma an tabbatar da tsaron sarkar masana'antu. Saboda haka, hankali na masana'antar ya koma kan sarrafa farashi da haɓaka inganci. Kamar yadda aka nuna a Jadawali na 1, idan aka kwatanta da 150 mm, SiC na mm 200 yana da yawan amfani da gefen, kuma fitowar guntun wafer guda ɗaya za a iya ƙara shi da kusan sau 1.8. Bayan fasahar ta girma, farashin kera guntu ɗaya za a iya rage shi da 30%. Ci gaban fasaha na 200 mm hanya ce ta kai tsaye ta "rage farashi da ƙara inganci", kuma shine mabuɗin masana'antar semiconductor ta ƙasata don "gudu a layi ɗaya" ko ma "guda".
Bambanta da tsarin na'urar Si,Na'urorin wutar lantarki na SiC semiconductorAna sarrafa su duka kuma an shirya su da yadudduka na epitaxial a matsayin ginshiƙi. Wafers na epitaxial muhimman kayan aiki ne na asali don na'urorin wutar lantarki na SiC. Ingancin Layer na epitaxial yana ƙayyade yawan amfanin na'urar kai tsaye, kuma farashinsa ya kai kashi 20% na farashin kera guntu. Saboda haka, haɓakar epitaxial muhimmin mahaɗi ne na tsaka-tsaki a cikin na'urorin wutar lantarki na SiC. Babban iyakar matakin aiwatar da epitaxial ana ƙaddara shi ta hanyar kayan aikin epitaxial. A halin yanzu, matakin wurin kayan aikin epitaxial na SiC 150mm a China yana da girma sosai, amma tsarin gabaɗaya na kayan aikin epitaxial na 200mm yana ƙasa da matakin duniya a lokaci guda. Saboda haka, don magance buƙatu na gaggawa da matsalolin cikas na kera kayan epitaxial masu girma da inganci don haɓaka masana'antar semiconductor na gida na ƙarni na uku, wannan takarda ta gabatar da kayan aikin epitaxial na SiC 200 mm waɗanda aka haɓaka cikin nasara a ƙasata, kuma suna nazarin tsarin epitaxial. Ta hanyar inganta sigogin tsari kamar zafin aiki, ƙimar kwararar iskar gas mai ɗaukar kaya, rabon C/Si, da sauransu, daidaiton yawan abu <3%, kauri mara daidaito <1.5%, rashin ƙarfi Ra <0.2 nm da yawan lahani mai mutuwa <0.3 hatsi/cm2 na 150 mm da 200 mm SiC wafers tare da wutar lantarki mai ƙarfin silicon carbide 200 mm da aka haɓaka daban-daban. Matsayin aikin kayan aiki zai iya biyan buƙatun shirye-shiryen na'urar wutar lantarki mai inganci na SiC.
Gwaji 1
1.1 Ka'idarSiC epitaxialtsari
Tsarin girma na homoepitaxial na 4H-SiC ya ƙunshi matakai guda biyu masu mahimmanci, wato, etching mai zafi a cikin yanayin zafi na substrate 4H-SiC da kuma tsarin adana tururin sinadarai iri ɗaya. Babban manufar etching mai zafi a cikin yanayin zafi shine a cire lalacewar ƙasan substrate bayan etching wafer, ruwan gogewa da ya rage, barbashi da Layer oxide, kuma ana iya samar da tsarin matakan atomic na yau da kullun akan saman substrate ta hanyar etching. Yawanci ana yin etching mai zafi a cikin yanayin hydrogen. Dangane da ainihin buƙatun tsari, ana iya ƙara ƙaramin adadin iskar gas mai taimako, kamar hydrogen chloride, propane, ethylene ko silane. Zafin etching mai zafi a cikin yanayin hydrogen gabaɗaya yana sama da 1 600 ℃, kuma matsin lambar ɗakin amsawa gabaɗaya ana sarrafa shi ƙasa da 2 × 104 Pa yayin aikin etching.
Bayan an kunna saman substrate ta hanyar etching in-situ, yana shiga cikin tsarin adana tururin sinadarai mai zafi, wato, tushen girma (kamar ethylene/propane, TCS/silane), tushen doping (n-type doping source nitrogen, p-type doping source TMMal), da iskar gas mai taimako kamar hydrogen chloride ana jigilar su zuwa ɗakin amsawa ta hanyar kwararar iskar gas mai ɗaukar kaya (yawanci hydrogen). Bayan iskar gas ta yi aiki a cikin ɗakin amsawa mai zafi, wani ɓangare na precursor yana amsawa ta hanyar sinadarai kuma yana shawagi a kan saman wafer, kuma wani Layer epitaxial mai kama da kristal guda ɗaya mai takamaiman yawan doping, kauri na musamman, da inganci mafi girma ana samar da shi akan saman substrate ta amfani da substrate 4H-SiC guda ɗaya a matsayin samfuri. Bayan shekaru na bincike na fasaha, fasahar homoepitaxial 4H-SiC ta girma kuma ana amfani da ita sosai a cikin samar da masana'antu. Fasaha homoepitaxial 4H-SiC da aka fi amfani da ita a duniya tana da halaye guda biyu na yau da kullun:
(1) Ta amfani da wani abu mai kama da "off-axis" (idan aka kwatanta da "plumber plane" na "crystal plane" na "<0001", zuwa ga alkiblar lu'ulu'u na "<11-20") a matsayin samfuri, ana sanya wani Layer mai tsarki mai siffar crystal guda ɗaya mai siffar crystal 4H-SiC ba tare da ƙazanta ba a kan substrate a cikin nau'in yanayin girma na matakai-gudu. Girman homoepitaxial na farko na 4H-SiC ya yi amfani da wani abu mai siffar crystal mai kyau, wato, "plumber Si" na "0001" don girma. Yawan matakan atom a saman abin da aka yi da lu'ulu'u mai kyau yana da ƙasa kuma lanƙwasa suna da faɗi. Girman nucleation mai girma biyu yana da sauƙin faruwa yayin aikin epitaxy don samar da lu'ulu'u na "3C" na "Crystal SiC" (3C-SiC). Ta hanyar yankewa daga "off-axis", ana iya gabatar da matakan atom mai girma da kunkuntar a saman abin da aka yi da lu'ulu'u na "4H-SiC <0001", kuma mai gabatarwar da aka yi da lu'ulu'u zai iya isa ga matsayin matakin atom yadda ya kamata tare da ƙarancin kuzarin saman ta hanyar yaɗuwar saman. A matakin, matsayin haɗin ƙungiyar atom/ƙwayoyin halitta na musamman ne, don haka a cikin yanayin haɓakar kwararar matakai, Layer epitaxial zai iya gadar jerin jerin siginar ...
(2) Ana samun ci gaban epitaxial mai sauri ta hanyar gabatar da tushen silicon mai ɗauke da chlorine. A cikin tsarin adana tururin sinadarai na SiC na gargajiya, silane da propane (ko ethylene) su ne manyan tushen ci gaba. A cikin tsarin ƙara yawan ci gaba ta hanyar ƙara yawan kwararar tushen ci gaba, yayin da ma'aunin matsin lamba na ɓangaren silicon ke ci gaba da ƙaruwa, yana da sauƙi a samar da tarin silicon ta hanyar nucleation na iskar gas mai kama da juna, wanda ke rage yawan amfani da tushen silicon sosai. Samar da tarin silicon yana iyakance haɓaka yawan ci gaban epitaxial sosai. A lokaci guda, tarin silicon na iya kawo cikas ga ci gaban kwararar matakai da haifar da nakasa. Domin guje wa nucleation na lokacin iskar gas mai kama da juna da kuma ƙara yawan ci gaban epitaxial, gabatar da tushen silicon mai tushen chlorine a halin yanzu shine babban hanyar da ake amfani da ita don ƙara yawan ci gaban epitaxial na 4H-SiC.
Kayan aikin epitaxial na SiC mai girman inci 8 1.2 da yanayin aiki
An gudanar da gwaje-gwajen da aka bayyana a cikin wannan takarda duk akan kayan aikin epitaxial na SiC mai tsayin 150/200 mm (6/8-inch) mai jituwa da bangon zafi mai tsayin 150/200 mm (6/8-inch) wanda Kamfanin Rukunin Fasaha ta Lantarki na 48 na Cibiyar China ta haɓaka shi daban-daban. Tanderun epitaxial yana tallafawa lodawa da sauke wafer ta atomatik gaba ɗaya. Hoto na 1 zane ne na tsarin ciki na ɗakin amsawa na kayan aikin epitaxial. Kamar yadda aka nuna a Hoto na 1, bangon waje na ɗakin amsawa kararrawa ce mai lanƙwasa mai sanyaya ruwa, kuma cikin kararrawa akwai ɗakin amsawa mai zafi sosai, wanda ya ƙunshi jikewar carbon mai hana zafi, ramin graphite na musamman mai tsarki, tushen juyawa mai shawagi na gas, da sauransu. An rufe dukkan kararrawa ta quartz da coil mai silinda, kuma ɗakin amsawa da ke cikin kararrawa yana dumama ta hanyar lantarki ta hanyar samar da wutar lantarki ta matsakaici-mita. Kamar yadda aka nuna a Hoto na 1 (b), iskar gas mai ɗaukar kaya, iskar amsawa, da iskar doping duk suna gudana ta saman wafer a cikin kwararar laminar a kwance daga sama na ɗakin amsawa zuwa ƙasan ɗakin amsawa kuma ana fitar da su daga ƙarshen iskar wutsiya. Don tabbatar da daidaito a cikin wafer, wafer ɗin da tushen iska ke ɗauke da shi koyaushe ana juyawa shi yayin aikin.
Substrate da aka yi amfani da shi a cikin gwajin shine 150 mm, 200 mm (inci 6, inci 8) <1120> shugabanci 4° mai kusurwa biyu mai sarrafa siC mai gefe biyu wanda Shanxi Shuoke Crystal ta samar. Ana amfani da Trichlorosilane (SiHCl3, TCS) da ethylene (C2H4) a matsayin manyan hanyoyin girma a cikin gwajin aikin, daga cikinsu ana amfani da TCS da C2H4 a matsayin tushen silicon da tushen carbon bi da bi, ana amfani da nitrogen mai tsarki (N2) a matsayin tushen doping na nau'in n, kuma ana amfani da hydrogen (H2) a matsayin iskar gas mai narkewa da iskar gas mai ɗaukar kaya. Yanayin zafin jiki na tsarin epitaxial shine 1 600 ~ 1 660 ℃, matsin lamba na tsari shine 8 × 103 ~ 12 × 103 Pa, kuma yawan kwararar iskar gas mai ɗaukar kaya na H2 shine 100 ~ 140 L/min.
1.3 Gwajin Epitaxial wafer da kuma bayaninsa
An yi amfani da na'urar auna ƙarfin infrared Fourier (mai kera kayan aiki Thermalfisher, samfurin iS50) da kuma na'urar gwada yawan sinadarin mercury probe (mai kera kayan aiki Semilab, samfurin 530L) don tantance matsakaicin da rarrabawar kauri da yawan sinadarin epitaxial; an ƙayyade kauri da yawan sinadarin doping na kowane wuri a cikin layin epitaxial ta hanyar ɗaukar maki tare da layin diamita wanda ke haɗa layin al'ada na babban gefen ma'ana a 45° a tsakiyar wafer tare da cire gefen 5mm. Don wafer mai girman mm 150, an ɗauki maki 9 tare da layin diamita ɗaya (diamita biyu sun daidaita da juna), kuma don wafer mai girman mm 200, an ɗauki maki 21, kamar yadda aka nuna a Hoto na 2. An yi amfani da na'urar hangen nesa ta ƙarfin atomic (mai kera kayan aiki Bruker, samfurin Dimension Icon) don zaɓar yankuna 30 μm×30 μm a yankin tsakiya da yankin gefen (cire gefen 5mm) na wafer mai girman epitaxial don gwada ƙaiƙayin saman layin epitaxial; An auna lahani na layin epitaxial ta amfani da na'urar gwada lahani a saman (masana'antar kayan aiki China Electronics. An siffanta hoton 3D ta hanyar na'urar firikwensin radar (samfurin Mars 4410 pro) daga Kefenghua.
Lokacin Saƙo: Satumba-04-2024