2 Mhedzisiro yekuedza nekukurukurirana
2.1Rutivi rweEpitaxialukobvu uye kufanana
Ukobvu hweEpitaxial layer, huwandu hwedoping uye kufanana ndezvimwe zvezviratidzo zvikuru zvekutarisa mhando yemawafer epitaxial. Ukobvu hunodzorwa nemazvo, huwandu hwedoping uye kufanana mukati mewafer ndizvo zvakakosha pakuona kushanda uye kugara kwenguva refu kweZvishandiso zvemagetsi zveSiC, uye ukobvu hwe epitaxial layer uye kufanana kwehuwandu hwe doping zvakare hwaro hwakakosha hwekuyera kugona kwemaitiro emidziyo ye epitaxial.
Mufananidzo 3 unoratidza kufanana kweukobvu uye kupararira kwe 150 mm ne 200 mmMawafer eSiC epitaxialZvinogona kuonekwa kubva pamufananidzo kuti curve yekupararira kwe epitaxial layer thickness yakaenzana pakati pewafer. Nguva ye epitaxial process i600s, avhareji ye epitaxial layer thickness ye 150mm epitaxial wafer i10.89 um, uye hunhu hwakaenzana i1.05%. Kana tichiverenga, epitaxial growth rate i65.3 um/h, inova ndiyo nhanho ye fast epitaxial process. Pasi penguva imwechete ye epitaxial process, hunhu hwe epitaxial layer ye 200 mm epitaxial wafer i10.10 um, hunhu hwakaenzana huri mukati me1.36%, uye huwandu hwese hwekukura i60.60 um/h, huri pasi zvishoma pane 150 mm epitaxial growth rate. Izvi zvinodaro nekuti pane kurasikirwa kuri pachena munzira kana silicon source necarbon source zvichiyerera kubva kumusoro kwereaction chamber kuburikidza newafer pamusoro pewafer kuenda pasi pereaction chamber, uye nzvimbo yewafer ye200 mm yakakura kupfuura 150 mm. Gasi rinoyerera nepamusoro pe200 mm wafer kwenguva yakareba, uye gasi rinoshandiswa munzira rakakura. Kana wafer ikaramba ichitenderera, ukobvu hwese hweepitaxial layer hutete, saka mwero wekukura unononoka. Kazhinji, kufanana kweukobvu hwe150 mm ne200 mm epitaxial wafers kwakanaka kwazvo, uye kugona kwemuchina kunogona kusangana nezvinodiwa zvemidziyo yepamusoro.
2.2 Kuwanda uye kufanana kwekushandiswa kwedoping muchikamu cheEpitaxial layer
Mufananidzo 4 unoratidza kufanana kwehuwandu hwedoping uye kugoverwa kwe curve ye 150 mm ne 200 mmMawafer eSiC epitaxial. Sezvinoratidzwa pamufananidzo, curve yekugovera concentration pa epitaxial wafer ine symmetry yakajeka kana tichienzanisa nepakati pe wafer. Kufanana kwe doping concentration ye 150 mm ne 200 mm epitaxial layers i2.80% uye 2.66% zvichiteerana, iyo inogona kudzorwa mukati me3%, inova nhanho yakanaka kwazvo yemidziyo yakafanana yepasi rose. Doping concentration curve ye epitaxial layer inogoverwa muchimiro che "W" pamwe nedhayamita, iyo inonyanya kutsanangurwa nenzvimbo yekuyerera kwe hot wall epitaxial furnace, nekuti direction ye airflow ye horizontal airflow epitaxial growth furnace inobva ku air inlet end (kumusoro) uye inoyerera ichibva ku downstream end nenzira ye laminar kuburikidza ne wafer surface; nekuti mwero we "along-the-way depletion" wecarbon source (C2H4) wakakwira kupfuura wesilicon source (TCS), kana wafer ichitenderera, C/Si chaiyo iri pamusoro pewafer inoderera zvishoma nezvishoma kubva kumucheto kuenda pakati (carbon source iri pakati ishoma), zvichienderana ne "competitive position theory" yeC naN, huwandu hwedoping pakati pewafer hunoderera zvishoma nezvishoma kuenda kumucheto, kuitira kuti pave nekuenzana kwakanaka kweconcentration, mupendero weN2 unowedzerwa semuripo panguva ye epitaxial process kuti uderedze kudzikira kwedoping concentration kubva pakati kuenda kumucheto, kuitira kuti curve yekupedzisira yedoping concentration ipe chimiro che "W".
2.3 Kukanganisika kweEpitaxial layer
Pamusoro pekukora uye huwandu hwedoping, huwandu hwe epitaxial layer defect control ndiyo parameter huru yekuyera mhando ye epitaxial wafers uye chiratidzo chakakosha chekugona kwekushanda kwe epitaxial equipment. Kunyangwe SBD neMOSFET vaine zvinodiwa zvakasiyana zvezvikanganiso, zvikanganiso zviri pachena zve surface morphology zvakaita se drop defects, triangle defects, carrot defects, comet defects, nezvimwewo zvinotsanangurwa se killer defects dzeSBD neMOSFET. Mikana yekukundikana kwema chips ane defects idzi yakakura, saka kudzora huwandu hwe killer defects kwakakosha zvikuru pakuvandudza goho re chip uye kuderedza mitengo. Mufananidzo 5 unoratidza kugoverwa kwe killer defects dze 150 mm ne 200 mm SiC epitaxial wafers. Pasi pemamiriro ekuti hapana kusawirirana kuri pachena muC/Si ratio, carrot defects uye comet defects zvinogona kubviswa, nepo drop defects uye triangle defects zvine chekuita nekuchena panguva yekushanda kwe epitaxial equipment, graphite level yekusachena mu reaction chamber, uye mhando ye substrate. Kubva paTafura 2, zvinogona kuonekwa kuti density ye 150 mm uye 200 mm epitaxial wafers inogona kudzorwa mukati me 0.3 particles/cm2, inova nhanho yakanaka kwazvo yemhando imwe chete yemidziyo. Density control level ye 150 mm epitaxial wafer iri nani pane 200 mm epitaxial wafer. Izvi zvinodaro nekuti maitiro ekugadzirira substrate ye 150 mm yakakura kupfuura 200 mm, mhando ye substrate iri nani, uye density control level ye 150 mm graphite reaction chamber iri nani.
2.4 Kuomarara kwepadenga reEpitaxial wafer
Mufananidzo 6 unoratidza mifananidzo yeAFM yenzvimbo dzewafer dzeSiC epitaxial dze150 mm ne200 mm. Zvinogona kuonekwa kubva pamufananidzo kuti mudzi wepamusoro une avhareji ye square roughness Ra ye150 mm ne200 mm epitaxial wafers i0.129 nm ne0.113 nm zvichiteerana, uye nzvimbo ye epitaxial layer yakatsetseka pasina chiitiko che macro-step aggregation. Chiitiko ichi chinoratidza kuti kukura kwe epitaxial layer kunogara kuchichengetedza step flow growth mode panguva yese ye epitaxial process, uye hapana step aggregation inoitika. Zvinogona kuonekwa kuti nekushandisa optimized epitaxial growth process, smooth epitaxial layers dzinogona kuwanikwa pa 150 mm ne200 mm low-angle substrates.
3 Mhedziso
Mawafer epitaxial epitaxial e150 mm ne200 mm 4H-SiC akagadzirwa zvakanaka pamidziyo yemumba achishandisa michina yekukura ye200 mm SiC epitaxial yakagadzirwa yega, uye maitiro eepitaxial epataxial akakodzera 150 mm ne200 mm akagadzirwa. Mwero wekukura kweepitaxial unogona kupfuura 60 μm/h. Kunyangwe ichizadzisa zvinodiwa ne epitaxy inokurumidza, mhando ye epitaxial wafer yakanaka kwazvo. Kufanana kweukobvu hwemawafer epitaxial epitaxial e150 mm ne200 mm SiC kunogona kudzorwa mukati me1.5%, kufanana kwehuwandu kuri pasi pe3%, defect defect density iri pasi pe0.3 particles/cm2, uye epitaxial surface roughness root mean square Ra iri pasi pe0.15 nm. Zviratidzo zvepakati zvemawafer epitaxial zviri padanho repamusoro muindasitiri.
Chitubu: Midziyo Yakakosha yeIndasitiri yeMagetsi
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: Gunyana-04-2024