Pakadali pano, makampani a SiC akusintha kuchoka pa 150 mm (6 mainchesi) mpaka 200 mm (8 mainchesi). Pofuna kukwaniritsa zofunikira zachangu zazikuluzikulu, zapamwamba za SiC homoepitaxial wafers pamakampani, 150mm ndi 200mm4H-SiC homoepitaxial waferszidakonzedwa bwino pazigawo zapakhomo pogwiritsa ntchito zida zokulirapo za 200mm SiC epitaxial kukula. Njira ya homoepitaxial yoyenera 150mm ndi 200mm inapangidwa, momwe kukula kwa epitaxial kungakhale kwakukulu kuposa 60um / h. Mukakumana ndi epitaxy yothamanga kwambiri, mtundu wa epitaxial wafer ndi wabwino kwambiri. Makulidwe ofanana ndi 150 mm ndi 200 mmSiC epitaxial wafersimatha kulamuliridwa mkati mwa 1.5%, kufanana kwandende ndi zosakwana 3%, kusalimba koopsa kwapang'onopang'ono ndi zosakwana 0,3 particles/cm2, ndi epitaxial surface roughness root mean square Ra ndi zosakwana 0.15nm, ndipo zizindikiro zonse zoyambirira zili pamlingo wapamwamba wamakampani.
Silicon Carbide (SiC)ndi m'modzi mwa oimira zida za semiconductor za m'badwo wachitatu. Ili ndi mawonekedwe amphamvu yakusweka kwamunda, matenthedwe abwino kwambiri, kuthamanga kwakukulu kwa ma elekitironi, komanso kukana kwamphamvu kwa radiation. Iwo kwambiri kukodzedwa mphamvu processing mphamvu ya zipangizo mphamvu ndipo akhoza kukwaniritsa zofunika utumiki wa m'badwo wotsatira wa zida zamagetsi zamagetsi kwa zipangizo ndi mphamvu mkulu, ang'onoang'ono, kutentha, cheza mkulu ndi zinthu zina kwambiri. Ikhoza kuchepetsa malo, kuchepetsa kugwiritsa ntchito mphamvu komanso kuchepetsa zofunikira zozizira. Zabweretsa kusintha kwa magalimoto atsopano amagetsi, mayendedwe apanjanji, ma gridi anzeru ndi magawo ena. Chifukwa chake, ma semiconductors a silicon carbide azindikirika ngati zinthu zabwino zomwe zingatsogolere m'badwo wotsatira wa zida zamagetsi zamagetsi zamagetsi. M'zaka zaposachedwa, chifukwa cha thandizo la ndondomeko ya dziko pa chitukuko cha mafakitale a semiconductor a m'badwo wachitatu, kafukufuku ndi chitukuko ndi zomangamanga za makina a makina a 150 mm SiC zatsirizidwa ku China, ndipo chitetezo cha mafakitale chatsimikiziridwa. Chifukwa chake, chidwi chamakampaniwo chasintha pang'onopang'ono ndikuwongolera mtengo komanso kukonza bwino. Monga momwe tawonetsera mu Table 1, poyerekeza ndi 150 mm, 200 mm SiC ili ndi mlingo wapamwamba wogwiritsira ntchito, ndipo kutulutsa kwa tchipisi tating'onoting'ono ting'onoting'ono kumatha kuwonjezeka pafupifupi nthawi 1.8. Tekinoloje ikakhwima, mtengo wopangira chip umodzi ukhoza kuchepetsedwa ndi 30%. Kupambana kwaukadaulo kwa 200 mm ndi njira yolunjika "yochepetsera ndalama ndikuwonjezera magwiridwe antchito", komanso ndiye chinsinsi chamakampani opanga ma semiconductor adziko langa "kuyendetsa limodzi" kapena "kutsogolera".
Zosiyana ndi njira ya chipangizo cha Si,Zida zamagetsi za SiC semiconductorzonse zimakonzedwa ndikukonzedwa ndi zigawo za epitaxial monga mwala wapangodya. Zophika za Epitaxial ndizofunikira pazida zamagetsi za SiC. Ubwino wa epitaxial wosanjikiza umatsimikizira mwachindunji zokolola za chipangizocho, ndipo mtengo wake umawerengera 20% ya mtengo wopanga chip. Chifukwa chake, kukula kwa epitaxial ndichinthu chofunikira chapakati pazida zamagetsi za SiC. Malire apamwamba a epitaxial process level amatsimikiziridwa ndi zida za epitaxial. Pakali pano, digiri ya kumasulira kwa zida za 150mm SiC epitaxial ku China ndizokwera kwambiri, koma masanjidwe onse a 200mm akutsalira kumbuyo kwa mayiko nthawi imodzi. Chifukwa chake, pofuna kuthana ndi zovuta zomwe zikufunika mwachangu komanso zovuta zamabotolo azinthu zazikulu, zapamwamba kwambiri, zapamwamba kwambiri za epitaxial popanga mafakitale amtundu wachitatu wa semiconductor, pepala ili likuwonetsa zida za 200 mm SiC epitaxial zomwe zidapangidwa bwino m'dziko langa, ndikuphunzira njira ya epitaxial. Ndi kukhathamiritsa ndondomeko magawo monga ndondomeko kutentha, chonyamulira mpweya otaya mlingo, C/Si chiŵerengero, etc., ndende uniformity <3%, makulidwe sanali ofanana <1.5%, roughness Ra <0.2 nm ndi amapha chilema osalimba <0.3 mbewu/cm2 wa 150 mamilimita ndi 200 mamilimita SiC epitaxial anayamba silicon wafer2 epitaxial0 epitaxial 2 epitaxial 2 0. ng'anjo amapezedwa. Mlingo wa zida zopangira zida zitha kukwaniritsa zofunikira zakukonzekera zida zamphamvu za SiC.
1 Yesani
1.1 Mfundo yaSiC epitaxialndondomeko
Njira ya 4H-SiC homoepitaxial kukula makamaka imaphatikizapo masitepe awiri ofunika, omwe ndi, kutentha kwambiri kwa in-situ ya 4H-SiC gawo lapansi ndi ndondomeko yofanana ya nthunzi ya mankhwala. Cholinga chachikulu cha gawo lapansi mu-situ etching ndi kuchotsa pansi pa nthaka kuwonongeka kwa gawo lapansi pambuyo yopyapyala kupukuta, otsalira kupukuta madzi, particles ndi okusayidi wosanjikiza, ndi wokhazikika atomiki sitepe dongosolo akhoza kupangidwa pa gawo lapansi ndi etching. In-situ etching nthawi zambiri imachitika mumlengalenga wa hydrogen. Malingana ndi zofunikira zenizeni za ndondomekoyi, mpweya wowonjezera wochepa ukhoza kuwonjezeredwa, monga hydrogen chloride, propane, ethylene kapena silane. Kutentha kwa in-situ hydrogen etching nthawi zambiri kumakhala pamwamba pa 1 600 ℃, ndipo kupanikizika kwa chipinda chochitiramo nthawi zambiri kumayendetsedwa pansi pa 2 × 104 Pa panthawi ya etching.
Pambuyo gawo lapansi ndi adamulowetsa ndi in-situ etching, amalowa mkulu-kutentha mankhwala nthunzi mafunsidwe ndondomeko, ndiko kuti, gwero la kukula (monga ethylene/propane, TCS/silane), doping gwero (n-mtundu doping gwero nayitrogeni, p-mtundu doping gwero TMAl), ndi mpweya wothandiza monga hydrogen kuti amayenda chamkuyu wa chloride otaya kanthu. (nthawi zambiri hydrogen). Pambuyo mpweya amachitira mu mkulu-kutentha anachita chipinda, mbali ya kalambulabwalo amachitira mankhwala ndi adsorbs pamwamba yopyapyala pamwamba, ndi single-crystal homogeneous 4H-SiC epitaxial wosanjikiza ndi yeniyeni doping ndende, makulidwe enieni, ndi apamwamba khalidwe aumbike pa gawo lapansi pogwiritsa ntchito single-crystal template 4H-SiC gawo lapansi. Pambuyo pazaka zambiri zaukadaulo, ukadaulo wa 4H-SiC homoepitaxial wakhwima ndipo umagwiritsidwa ntchito kwambiri popanga mafakitale. Ukadaulo wogwiritsidwa ntchito kwambiri wa 4H-SiC homoepitaxial padziko lapansi uli ndi mawonekedwe awiri:
(1) Pogwiritsa ntchito mbali yotalikirapo (yokhudzana ndi <0001> ndege ya crystal, yopita ku <11-20> crystal direction) oblique cut substrate monga template, high-purity single-crystal 4H-SiC epitaxial wosanjikiza popanda zonyansa amaikidwa pa gawo lapansi mu mawonekedwe a sitepe-flow flow mode kukula. Kukula koyambirira kwa 4H-SiC homoepitaxial kunagwiritsa ntchito gawo labwino la kristalo, ndiko kuti, <0001> Si ndege kuti ikule. Kachulukidwe ka masitepe a atomiki pamtunda wa gawo lapansi labwino la kristalo ndiotsika ndipo masitepe ake ndi otakata. Kukula kwa nucleation yamitundu iwiri kumakhala kosavuta kuchitika panthawi ya epitaxy kupanga 3C crystal SiC (3C-SiC). Ndi kudula mbali-olamulira, kachulukidwe, yopapatiza bwalo m'lifupi masitepe atomiki akhoza anayambitsa pamwamba pa 4H-SiC <0001> gawo lapansi, ndi kalambulabwalo adsorbed akhoza bwino kufika atomiki sitepe udindo ndi otsika pamwamba mphamvu kudzera padziko kufalikira. Pa sitepe, kalambulabwalo atomu/maselo gulu chomangira malo ndi wapadera, kotero mu sitepe otaya kukula mode, wosanjikiza epitaxial akhoza mwangwiro cholowa Si-C awiri atomiki wosanjikiza masanjidwe a gawo lapansi kuti apange kristalo limodzi ndi gawo lofanana kristalo monga gawo lapansi.
(2) Kukula kothamanga kwa epitaxial kumatheka poyambitsa gwero la silicon lokhala ndi chlorine. M'machitidwe ochiritsira a SiC mankhwala opangira mpweya, silane ndi propane (kapena ethylene) ndizomwe zimakula. M'kati mwa kukulitsa kuchuluka kwa kukula powonjezera kuchuluka kwa gwero la gwero la kukula, pomwe kukakamiza pang'ono kwa gawo la silicon kukukulirakulira, ndikosavuta kupanga masango a silicon ndi nucleation ya gas homogeneous, yomwe imachepetsa kwambiri kugwiritsa ntchito gwero la silicon. Mapangidwe amagulu a silicon amachepetsa kwambiri kuwongolera kwa kukula kwa epitaxial. Nthawi yomweyo, masango a silicon amatha kusokoneza kukula kwa masitepe ndikuyambitsa vuto la nucleation. Pofuna kupewa kuphatikizika kwa gawo la gasi ndikuwonjezera kukula kwa epitaxial, kukhazikitsidwa kwa magwero a silicon opangidwa ndi chlorine pakali pano ndiyo njira yayikulu yowonjezerera kukula kwa epitaxial kwa 4H-SiC.
1.2 200 mm (8-inchi) SiC epitaxial zida ndi zinthu ndondomeko
Zoyesera zomwe zafotokozedwa mu pepala ili zonse zidachitika pa 150/200 mm (6/8-inchi) yogwirizana ndi monolithic yopingasa yopingasa khoma la SiC epitaxial zida zodziyimira pawokha ndi 48th Institute of China Electronics Technology Group Corporation. Ng'anjo ya epitaxial imathandizira kutsitsa ndikutsitsa kwathunthu kwawafa. Chithunzi 1 ndi chithunzi chojambula cha mkati mwa chipinda chochitiramo cha zipangizo za epitaxial. Monga momwe tawonetsera pa Chithunzi 1, khoma lakunja la chipinda chochitiramo ndi belu la quartz ndi interlayer woziziritsidwa ndi madzi, ndipo mkati mwa belu ndi chipinda chokhala ndi kutentha kwambiri, chomwe chimapangidwa ndi kutentha kwa mpweya wa carbon, chiyero chapadera cha graphite patsekeke, graphite mpweya woyandama wozungulira, ndi zina zotero. Chipinda chochitira mkati mwa belu chimatenthedwa ndi maginito amagetsi ndi magetsi otengera ma frequency apakati. Monga momwe chithunzi 1 (b) chikusonyezera, mpweya wonyamulira, gasi wochitirapo kanthu, ndi mpweya wa doping zonse zimayenda mozungulira pamwamba pa laminar yopingasa kuchokera kumtunda kwa chipinda chochitirapo kanthu kupita kumunsi kwa chipinda chochitiramo ndipo zimatulutsidwa kuchokera kumapeto kwa mpweya. Kuonetsetsa kusasinthika mkati mwa chowotchacho, chowotcha chomwe chimanyamulidwa ndi mpweya woyandama chimakhala chozungulira nthawi zonse.
Gawo lapansi lomwe limagwiritsidwa ntchito poyesera ndi malonda 150 mm, 200 mm (6 mainchesi, 8 mainchesi) <1120> malangizo 4 ° off-angle conductive n-mtundu 4H-SiC mbali ziwiri zopukutidwa SiC gawo lapansi lopangidwa ndi Shanxi Shuoke Crystal. Trichlorosilane (SiHCl3, TCS) ndi ethylene (C2H4) amagwiritsidwa ntchito ngati gwero lalikulu la kukula pakuyesa, komwe TCS ndi C2H4 zimagwiritsidwa ntchito ngati gwero la silicon ndi gwero la kaboni, motsatana, nayitrogeni woyeretsedwa kwambiri (N2) amagwiritsidwa ntchito ngati gwero la n-mtundu wa doping, ndipo haidrojeni (H2) amagwiritsidwa ntchito ngati gasi wothirira ndi mpweya wonyamula. Kutentha kwa njira ya epitaxial ndi 1 600 ~ 1 660 ℃, kuthamanga kwa ndondomeko ndi 8 × 103 ~ 12 × 103 Pa, ndi mpweya wonyamula mpweya wa H2 ndi 100 ~ 140 L / min.
1.3 Kuyesa kwa Epitaxial wafer ndi mawonekedwe
Fourier infrared spectrometer (wopanga zida Thermalfisher, model iS50) ndi mercury probe concentration tester (wopanga zida Semilab, model 530L) anagwiritsidwa ntchito kusonyeza tanthauzo ndi kugawa kwa epitaxial layer makulidwe ndi kukhazikika kwa doping; makulidwe ndi ndende ya doping pa mfundo iliyonse mu epitaxial wosanjikiza anatsimikiza potenga mfundo m'mimba mwake mzere kudutsa mzere wabwinobwino wa m'mphepete chachikulu cholozera pa 45 ° pakatikati pa mtanda ndi 5 mm m'mphepete kuchotsa. Kwa 150 mm wafer, mfundo 9 zinatengedwa pamodzi mzere m'mimba mwake (awiri awiri anali perpendicular wina ndi mzake), ndi 200 mm yopyapyala, mfundo 21 anatengedwa, monga momwe chithunzi 2. An atomic mphamvu maikulosikopu (zida wopanga Bruker, chitsanzo Dimension Icon) anagwiritsidwa ntchito kusankha 30 μm chigawo chapakati ndi edge madera 5 mm × 3 m'dera m'dera la 30 mm × kuchotsa) wa epitaxial wafer kuyesa pamwamba roughness wa wosanjikiza epitaxial; zolakwika za epitaxial layer zidayezedwa pogwiritsa ntchito choyezera cholakwika chapamwamba (wopanga zida China Electronics Chithunzi cha 3D chinali ndi sensor ya radar (model Mars 4410 pro) yochokera ku Kefenghua.
Nthawi yotumiza: Sep-04-2024