2 Sakamakon gwaji da tattaunawa
2.1Layer na Epitaxialkauri da daidaito
Kauri na Layer na Epitaxial, yawan shan maganin da kuma daidaiton sa suna ɗaya daga cikin manyan alamomin da ke tantance ingancin wafers na epitaxial. Kauri mai kyau, yawan shan maganin da kuma daidaiton sa a cikin wafer sune mabuɗin tabbatar da aiki da daidaiton sa.Na'urorin wutar lantarki na SiC, da kauri na Layer na epitaxial da daidaiton yawan amfani da doping suma muhimman tushe ne don auna ƙarfin aikin kayan aikin epitaxial.
Siffa ta 3 tana nuna daidaiton kauri da kuma lanƙwasa rarrabawa na 150 mm da 200 mmWafers na epitaxial na SiC. Za a iya gani daga hoton cewa kauri rarrabawar Layer epitaxial yana daidaitacce game da tsakiyar wurin wafer. Lokacin aiwatar da epitaxial shine 600s, matsakaicin kauri na Layer epitaxial na Epitaxial wafer 150mm shine 10.89 um, kuma daidaiton kauri shine 1.05%. Ta hanyar lissafi, ƙimar girma na Epitaxial shine 65.3 um/h, wanda shine matakin aikin epitaxial na yau da kullun. A ƙarƙashin lokacin aikin epitaxial iri ɗaya, kauri na Layer epitaxial na Epitaxial wafer 200 mm shine 10.10 um, daidaiton kauri yana cikin 1.36%, kuma jimlar ƙimar girma shine 60.60 um/h, wanda ya ɗan yi ƙasa da ƙimar girma na Epitaxial 150 mm. Wannan ya faru ne saboda akwai asara a hanya lokacin da tushen silicon da tushen carbon ke kwarara daga sama na ɗakin amsawa ta saman wafer zuwa ƙasan ɗakin amsawa, kuma yankin wafer mai girman mm 200 ya fi girma fiye da mm 150. Iskar gas ɗin tana ratsa saman wafer mai girman mm 200 na tsawon nisa, kuma iskar gas da ake sha a hanya ta fi yawa. A ƙarƙashin yanayin da wafer ɗin ke ci gaba da juyawa, kauri gaba ɗaya na layin epitaxial ya fi siriri, don haka saurin girma yana raguwa. Gabaɗaya, daidaiton kauri na wafers mai girman mm 150 da mm 200 yana da kyau, kuma ikon aiwatar da kayan aiki na iya biyan buƙatun na'urori masu inganci.
2.2 Yawan amfani da doping na Layer na Epitaxial da daidaito
Siffa ta 4 tana nuna daidaiton yawan shan maganin da kuma rarraba lanƙwasa na 150 mm da 200 mm.Wafers na epitaxial na SiCKamar yadda aka gani daga hoton, lanƙwasa rarrabawar taro a kan wafer ɗin epitaxial yana da daidaito a bayyane dangane da tsakiyar wafer ɗin. Daidaiton yawan doping na yadudduka na epitaxial na 150 mm da 200 mm shine 2.80% da 2.66% bi da bi, wanda za'a iya sarrafa shi cikin 3%, wanda shine kyakkyawan matakin ga kayan aiki na ƙasashen duniya iri ɗaya. Lanƙwasa yawan doping na layin epitaxial yana rarrabawa a siffar "W" tare da alkiblar diamita, wanda galibi ana ƙayyade shi ta hanyar filin kwarara na tanderun epitaxial mai zafi a kwance, saboda alkiblar iska na tanderun girma na epitaxial iska mai kwance yana daga ƙarshen shigar iska (sama) kuma yana gudana daga ƙarshen ƙasa ta hanyar laminar ta saman wafer; saboda "ragewar da ke kan hanya" na tushen carbon (C2H4) ya fi na tushen silicon (TCS) girma, lokacin da wafer ɗin ya juya, ainihin C/Si da ke kan saman wafer yana raguwa a hankali daga gefen zuwa tsakiya (tushen carbon a tsakiya ya yi ƙasa), bisa ga "ka'idar matsayi mai gasa" na C da N, yawan shan maganin a tsakiyar wafer yana raguwa a hankali zuwa gefen, domin samun daidaito mai kyau na tattarawa, an ƙara gefen N2 a matsayin diyya yayin aikin epitaxial don rage raguwar yawan shan maganin daga tsakiya zuwa gefen, don haka lanƙwasa na ƙarshe na tattarawa yana gabatar da siffa ta "W".
2.3 Lalacewar Layer na Epitaxial
Baya ga kauri da yawan shan ƙwayoyi, matakin kula da lahani na Layer epitaxial kuma babban ma'auni ne don auna ingancin wafers na epitaxial kuma muhimmin alama ne na ikon aiwatar da kayan aikin epitaxial. Duk da cewa SBD da MOSFET suna da buƙatu daban-daban don lahani, lahani na yanayin saman da aka fi gani kamar lahani na faɗuwa, lahani na alwatika, lahani na karas, lahani na tauraro mai wutsiya, da sauransu an bayyana su a matsayin lahani masu kisa na na'urorin SBD da MOSFET. Yiwuwar gazawar kwakwalwan da ke ɗauke da waɗannan lahani yana da yawa, don haka sarrafa adadin lahani masu kisa yana da matuƙar mahimmanci don inganta yawan amfanin guntu da rage farashi. Hoto na 5 yana nuna rarraba lahani masu kisa na wafers na epitaxial na SiC 150 mm da 200 mm. A ƙarƙashin yanayin cewa babu rashin daidaito a cikin rabon C/Si, lahani na karas da lahani na tauraro mai wutsiya za a iya kawar da su, yayin da lahani na faɗuwa da lahani na alwatika suna da alaƙa da kula da tsabta yayin aikin kayan aikin epitaxial, matakin ƙazanta na sassan graphite a cikin ɗakin amsawa, da ingancin substrate. Daga Jadawali na 2, za a iya ganin cewa yawan lahani na wafers na epitaxial 150 mm da 200 mm za a iya sarrafa su a cikin barbashi 0.3/cm2, wanda shine kyakkyawan matakin ga irin wannan kayan aiki. Matsayin kula da yawan lahani na wafer epitaxial 150 mm ya fi na wafer epitaxial 200 mm kyau. Wannan saboda tsarin shirya substrate na 150 mm ya fi girma fiye da na 200 mm, ingancin substrate ya fi kyau, kuma matakin kula da kazanta na ɗakin amsawa na graphite 150 mm ya fi kyau.
2.4 Ƙarfin saman wafer na epitaxial
Siffa ta 6 ta nuna hotunan AFM na saman wafers ɗin epitaxial na SiC 150 mm da 200 mm. Ana iya gani daga hoton cewa tushen saman yana nufin murabba'in kauri na Ra na wafers ɗin epitaxial na 150 mm da 200 mm shine 0.129 nm da 0.113 nm bi da bi, kuma saman layin epitaxial yana da santsi ba tare da wani abu mai bayyana na haɗakar matakai ba. Wannan lamari ya nuna cewa ci gaban layin epitaxial koyaushe yana kula da yanayin ci gaban kwararar matakai a duk lokacin aikin epitaxial, kuma babu wani tarawa na matakai da ke faruwa. Ana iya ganin cewa ta amfani da ingantaccen tsarin girma na epitaxial, ana iya samun layukan epitaxial masu santsi akan ƙananan kusurwa 150 mm da 200 mm.
Kammalawa 3
An shirya wafers ɗin epitaxial masu kama da juna na 150 mm da 200 mm 4H-SiC cikin nasara a kan ƙananan kayan gida ta amfani da kayan aikin girma na epitaxial na SiC 200 mm da aka haɓaka da kansu, kuma an haɓaka tsarin epitaxial masu kama da juna wanda ya dace da 150 mm da 200 mm. Yawan girma na epitaxial na iya zama sama da 60 μm/h. Yayin da yake biyan buƙatun epitaxial mai sauri, ingancin wafer ɗin epitaxial yana da kyau kwarai da gaske. Ana iya sarrafa daidaiton kauri na wafers ɗin epitaxial na SiC 150 mm da 200 mm cikin 1.5%, daidaiton yawan abu ƙasa da 3%, yawan lahani mai kisa ƙasa da barbashi 0.3/cm2, kuma matsakaicin tushen ƙaiƙayi na saman epitaxial Ra ƙasa da 0.15 nm. Alamun tsari na asali na wafers ɗin epitaxial suna kan matakin ci gaba a masana'antar.
Tushe: Kayan Aiki na Musamman na Masana'antar Lantarki
Marubuci: Xie Tianle, Li Ping, Yang Yu, Gong Xiaoliang, Ba Sai, Chen Guoqin, Wan Shengqiang
(Cibiyar Bincike ta 48 ta China Electronics Technology Group Corporation, Changsha, Hunan 410111)
Lokacin Saƙo: Satumba-04-2024