2 Mibairo yekuedza uye nhaurirano
2.1Epitaxial layerukobvu uye kufanana
Epitaxial layer thickness, doping concentration uye kufanana ndechimwe chezviratidzo zvakakosha zvekutonga kunaka kwe epitaxial wafers. Kunyatso kudzora ukobvu, doping kutarisisa uye kufanana mukati mewafer ndiyo kiyi yekuve nechokwadi chekuita uye kuenderana kwe.SiC magetsi midziyo, uye epitaxial layer ukobvu uye doping concentration kufanana zvakare akakosha mabhesi ekuyera iyo process kugona kweiyo epitaxial michina.
Mufananidzo 3 unoratidza ukobvu kufanana uye kugovera curve ye150 mm uye 200 mmSiC epitaxial wafers. Zvinogona kuoneka kubva pamufananidzo kuti epitaxial layer ukobvu hwekugovera curve inoenzanirana nezvepakati poindi yewafer. Iyo epitaxial process time ndeye 600s, avhareji epitaxial layer ukobvu hwe150mm epitaxial wafer i10.89 um, uye ukobvu hwakafanana i1.05%. Nekuverenga, iyo epitaxial yekukura mwero i65.3 um/h, inova yakajairika kukurumidza epitaxial process level. Pasi penguva imwecheteyo epitaxial process, iyo epitaxial layer ye200 mm epitaxial wafer ndeye 10.10 um, ukobvu hwakafanana huri mukati me1.36%, uye kukura kwese kuri 60.60 um/h, iyo yakadzikira zvishoma pane 150 mm epitaxial kukura. rate. Izvi zvinodaro nekuti pane kurasika kuri pachena munzira apo iyo silicon sosi uye kabhoni sosi inoyerera ichibva kumusoro kwekamuri yekupindura kuburikidza newaferi kumusoro kusvika kuzasi kwekamuri rekuita, uye 200 mm wafer nzvimbo yakakura kupfuura 150 mm. Iyo gasi inoyerera nepamusoro peiyo 200 mm wafer kwechinhambwe chakareba, uye iyo sosi gasi rinopedzwa munzira rinowedzera. Pasi pemamiriro ekuti wafer inoramba ichitenderera, huwandu hwese hwe epitaxial layer hwakatetepa, saka mwero wekukura unononoka. Pakazere, ukobvu hwakafanana hwe150 mm uye 200 mm epitaxial wafers hwakanakisa, uye kugona kwemaitiro emidziyo kunogona kusangana nezvinodiwa zvemhando yepamusoro michina.
2.2 Epitaxial layer doping concentration uye kufanana
Mufananidzo 4 unoratidza kufananidzwa kwedoping uye curve kugovera kwe150 mm uye 200 mm.SiC epitaxial wafers. Sezvinoonekwa kubva pamufananidzo, iyo yekumisikidza yekugovera curve pane epitaxial wafer ine symmetry iri pachena inoenderana nepakati pewafer. The doping concentration kufanana kwe150 mm uye 200 mm epitaxial layers i2.80% uye 2.66% zvakateerana, iyo inogona kudzorwa mukati me3%, inova nhanho yakanakisa yemidziyo yakafanana yenyika. Iyo doping yekumisikidza curve ye epitaxial layer inogoverwa mu "W" chimiro pamwe nedhayamita dhayamita, iyo inonyanya kutariswa nenzvimbo yekuyerera yeyakatwasuka inopisa madziro epitaxial furnace, nekuti iyo mhepo yekuyerera kweiyo horizontal airflow epitaxial growth furnace inobva. mhepo inopinza magumo (kumusoro kwerukova) uye inoyerera ichibuda kubva kumucheto kwerwizi nenzira ine laminar kuburikidza newafer pamusoro; nekuti iyo "parutivi-iyo-nzira yekuderera" mwero weiyo kabhoni sosi (C2H4) yakakwirira kupfuura iyo yesilicon sosi (TCS), kana wafer ichitenderera, iyo C/Si chaiyo pawafer pevhu inoderera zvishoma nezvishoma kubva kumucheto kuenda. iyo yepakati (iyo kabhoni sosi iri pakati ishoma), zvinoenderana ne "kukwikwidza chinzvimbo dzidziso" yeC neN, iyo doping yekumisikidza iri pakati pechifukidziro inodzikira zvishoma nezvishoma ichienda kumucheto, kuti uwane yakanakisa kutarisisa. kufanana, mupendero weN2 unowedzerwa semuripo panguva ye epitaxial maitiro ekuderedza kuderera kwekuita doping kubva pakati kusvika kumucheto, kuitira kuti yekupedzisira doping concentration curve inopa "W" chimiro.
2.3 Epitaxial layer defects
Kuwedzera kune ukobvu uye kusungirirwa kwedoping, mwero we epitaxial layer defect control zvakare iri musimboti parameter yekuyera kunaka kweepitaxial wafers uye chiratidzo chakakosha chekugona kwemaitiro epitaxial midziyo. Kunyangwe hazvo SBD neMOSFET zvine zvakasiyana zvinodiwa pakuremara, izvo zvinonyanya kujeka pamusoro morphology kuremara senge kudonhedza kuremara, katatu kuremara, karoti hurema, hurema hwekometi, nezvimwe zvinotsanangurwa seanouraya kuremara kweSBD neMOSFET zvishandiso. Mukana wekutadza kwemachipi ane hurema uhu wakakwira, saka kudzora huwandu hwehurema hwemhondi kwakakosha zvakanyanya mukuvandudza goho rechip uye kuderedza mitengo. Mufananidzo 5 unoratidza kugoverwa kwekuremara kwemhondi kwe150 mm uye 200 mm SiC epitaxial wafers. Pasi pemamiriro ekuti hapana kusaenzana kuri pachena muchiyero cheC / Si, kukanganisa kwekaroti uye kukanganisa kwekometi kunogona kubviswa zvachose, nepo kudonha kukanganiswa uye katatu kukanganiswa kwakabatana nekutonga kwehutsanana panguva yekushanda kwe epitaxial midziyo, kusachena kwechiyero chegraphite. zvikamu mukamuri yekupindura, uye kunaka kweiyo substrate. Kubva Tafura 2, zvinogona kuonekwa kuti mhondi defect density ye150 mm uye 200 mm epitaxial wafers inogona kudzorwa mukati me 0.3 particles/cm2, inova nhanho yakanakisa yemhando imwechete yemidziyo. Iyo inouraya defect density control level ye150 mm epitaxial wafer iri nani pane iyo ye200 mm epitaxial wafer. Izvi zvinodaro nekuti iyo substrate gadziriro ye 150 mm yakakura kupfuura iyo ye200 mm, iyo substrate mhando iri nani, uye kusachena kutonga mwero we150 mm graphite reaction chamber iri nani.
2.4 Epitaxial wafer pamusoro roughness
Mufananidzo 6 unoratidza mifananidzo yeAFM yepasi pe150 mm uye 200 mm SiC epitaxial wafers. Zvinogona kuonekwa kubva pamufananidzo kuti mudzi wepamusoro unoreva square roughness Ra ye 150 mm uye 200 mm epitaxial wafers ndeye 0.129 nm uye 0.113 nm zvichienderana, uye pamusoro peiyo epitaxial layer inotsvedza pasina pachena macro-step aggregation phenomenon. Ichi chiitiko chinoratidza kuti kukura kweiyo epitaxial layer inogara ichichengetedza nhanho inoyerera yekukura modhi panguva yese epitaxial process, uye hapana nhanho aggregation inoitika. Zvinogona kuonekwa kuti nekushandisa optimized epitaxial growth process, smooth epitaxial layers inogona kuwanikwa pa 150 mm uye 200 mm low-angle substrates.
3 Mhedziso
Iyo 150 mm uye 200 mm 4H-SiC homogeneous epitaxial wafers yakagadziridzwa zvakabudirira pama substrates epamba vachishandisa yakazvigadzira 200 mm SiC epitaxial kukura midziyo, uye homogeneous epitaxial process yakakodzera 150 mm uye 200 mm yakagadzirwa. Iyo epitaxial yekukura mwero inogona kuva yakakura kupfuura 60 μm/h. Ndichiri kusangana neinomhanya-mhanya epitaxy inodiwa, iyo epitaxial wafer mhando yakanaka. Ukobvu hwekuenzana kwe150 mm uye 200 mm SiC epitaxial wafers hunogona kudzorwa mukati me1.5%, iyo confusion kufanana iri pasi pe3%, iyo inouraya defect density isingasviki 0.3 particles/cm2, uye epitaxial pamusoro roughness mudzi zvinoreva square Ra. iri pasi pe0.15 nm. Iyo yakakosha process zviratidzo zveepitaxial wafers zviri padanho repamusoro muindasitiri.
Kunobva: Electronic Indasitiri Special Equipment
Munyori: Xie Tianle, Li Ping, Yang Yu, Gong Xiaoliang, Ba Sai, Chen Guoqin, Wan Shengqiang
(48th Research Institute of China Electronics Technology Group Corporation, Changsha, Hunan 410111)
Nguva yekutumira: Sep-04-2024