Chii chinonzi CVD SiC Coating?
Kuisa makemikari mumhepo (CVD) inzira yekuisa vacuum inoshandiswa kugadzira zvinhu zvakasimba zvine hutsanana hwakanyanya. Maitiro aya anowanzo shandiswa mumunda wekugadzira semiconductor kugadzira mafirimu matete pamusoro pemawafer. Mukugadzirira silicon carbide neCVD, substrate inoonekwa kune imwe kana kupfuura zvinoshanduka, izvo zvinoita semakemikari pamusoro pe substrate kuti zviise silicon carbide deposits inodiwa. Pakati penzira dzakawanda dzekugadzirira silicon carbide zvinhu, zvigadzirwa zvakagadzirwa nemakemikari vapor deposition zvine hunhu hwakafanana uye huchena, uye nzira iyi ine simba guru rekudzora maitiro. Zvinhu zveCVD silicon carbide zvine musanganiswa wakasiyana wehunhu hwakanaka hwekupisa, magetsi uye makemikari, zvichiita kuti zvive zvakakodzera kushandiswa muindasitiri ye semiconductor uko kunodiwa zvinhu zvinoshanda zvakanyanya. Zvikamu zveCVD silicon carbide zvinoshandiswa zvakanyanya mumidziyo yekucheka, michina yeMOCVD, michina yeSi epitaxial uye michina yeSiC epitaxial, michina yekukurumidza kugadzirisa kupisa nedzimwe nzvimbo.
Chinyorwa chino chinotarisa pakuongorora mhando yemafirimu matete anorimwa pakupisa kwakasiyana-siyana panguva yekugadziriraKuputira kweCVD SiC, kuitira kusarudza tembiricha yakakodzera kwazvo. Kuedza uku kunoshandisa graphite se substrate uye trichloromethylsilane (MTS) segasi rinobva pakupindura. SiC coating inoiswa ne low-pressure CVD process, uye micromorphology yeKuputira kweCVD SiCinoonekwa nekutarisa maikorosikopu emagetsi kuti iongorore kusimba kwayo.
Nekuti tembiricha yepamusoro pegrafiti substrate yakakwira zvikuru, gasi repakati richabviswa uye richaburitswa kubva pamusoro pesubstrate, uye pakupedzisira C naSi zvinosara pamusoro pesubstrate zvichagadzira solid phase SiC kuti zvigadzire SiC coating. Zvichienderana nemaitiro ekukura kweCVD-SiC ari pamusoro apa, zvinogona kuonekwa kuti tembiricha ichakanganisa kupararira kwegasi, kuora kweMTS, kuumbwa kwemadonhwe uye kubviswa uye kuburitswa kwegasi repakati, saka tembiricha yekuisa ichaita basa guru muchimiro cheSiC coating. Maumbirwo emicroscopic e coating ndiyo inonyanya kuoneka yehuwandu hwe coating. Nokudaro, zvakakosha kudzidza mhedzisiro yekupisa kwakasiyana kwekuisa pa microscopic morphology yeCVD SiC coating. Sezvo MTS ichigona kuora nekukanda SiC coating pakati pe900~1600℃, kuyedza uku kunosarudza tembiricha shanu dzekuisa 900℃, 1000℃, 1100℃, 1200℃ uye 1300℃ dzekugadzirira SiC coating kuti dzidzidze mhedzisiro yetembiricha paCVD-SiC coating. Maparamita chaiwo anoratidzwa muTafura 3. Mufananidzo 2 unoratidza chimiro chemicroscopic cheCVD-SiC coating inokura patembiricha dzakasiyana dzekuisa CVD.
Kana tembiricha yekuisa zvinhu iri 900℃, SiC yese inokura kuita ma fiber shapes. Zvinogona kuonekwa kuti dhayamita ye fiber imwe chete inenge 3.5μm, uye aspect ratio yayo inenge 3 (<10). Uyezve, inoumbwa ne nano-SiC particles dzisingaverengeki, saka ndeye polycrystalline SiC structure, iyo yakasiyana neSiC nanowires dzechinyakare uye single-crystal SiC whiskers. Iyi fibrous SiC i structure defect inokonzerwa ne process parameters dzisina musoro. Zvinogona kuonekwa kuti structure yeiyi SiC coating yakasununguka zvishoma, uye kune nhamba yakakura yema pores pakati pe fibrous SiC, uye density yakaderera kwazvo. Naizvozvo, tembiricha iyi haina kukodzera kugadzirira dense SiC coatings. Kazhinji, fibrous SiC structure defects inokonzerwa ne deposition tembiricha yakaderera zvakanyanya. Patembiricha yakaderera, mamorekuru madiki anonamirwa pamusoro pe substrate ane simba shoma uye kutadza kufamba zvakanaka. Nokudaro, mamorekuru madiki anowanzo famba uye anokura kusvika pa density yakaderera yeSiC grains (senge muromo we grain). Kukura kweSiC kunoramba kuripo kunozopedzisira kwaita kuti pave nekukanganisika kwechimiro cheSiC.
Kugadzirira kweCVD SiC Coating:
Kutanga, girafiti inoiswa muchoto chevacuum chinodziya zvakanyanya uye inochengetwa pa1500℃ kweawa imwe chete mumhepo ine Ar kuti ibvise dota. Zvadaro girafiti inochekwa kuita bhora re15x15x5mm, uye pamusoro pegirafiti inopukutwa ne1200-mesh sandpaper kubvisa maburi epamusoro anokanganisa kuiswa kweSiC. Bhuroko regirafiti rinogadziriswa rinogezwa neanhydrous ethanol nemvura yakasanganiswa, uye rozoiswa muovheni pa100℃ kuti riome. Pakupedzisira, girafiti inoiswa munzvimbo huru yekupisa yevira retubhu kuti iomeswe neSiC. Dhayagiramu ye chemical vapor deposition system inoratidzwa muMufananidzo 1.
IyoKuputira kweCVD SiCyakaonekwa nekutarisa maikorosikopu emagetsi kuti iongorore saizi yezvikamu zvayo uye huwandu hwayo. Pamusoro pezvo, mwero wekuisa SiC coating wakaverengerwa zvichienderana nefomula iri pazasi: VSiC=(m2-m1)/(Sxt)x100% VSiC=Chiyero chekuisa zvinhu; m2–huremu hwemuenzaniso wekuputira (mg); m1–huremu hwepasi (mg); Nzvimbo yeS-pamusoro pe substrate (mm2); t-nguva yekuiswa (h). CVD-SiC yakaoma, uye maitiro acho anogona kupfupikiswa seizvi: pakupisa kwakanyanya, MTS ichaparadzwa nekupisa kuti igadzire mamorekuru madiki ecarbon source nesilicon source. Mamorekuru madiki ecarbon source anosanganisira CH3, C2H2 neC2H4, uye mamorekuru madiki esilicon source anosanganisira SiCI2, SiCI3, nezvimwewo; mamorekuru madiki aya ecarbon source nesilicon source anobva aendeswa pamusoro pegraphite substrate negasi rinotakura negasi rakasanganiswa, uye mamorekuru madiki aya achanyungudutswa pamusoro pesubstrate nenzira yekunyungudutswa, uye ipapo makemikari achaitika pakati pemamorekuru madiki kuti aumbe madonhwe madiki anokura zvishoma nezvishoma, uye madonhwe acho achabatanawo, uye reaction yacho ichaperekedzwa nekuumbwa kwezvinogadzirwa zviri pakati nepakati (HCl gas); Kana tembiricha yakwira kusvika 1000 ℃, huwandu hweSiC coating hunovandudzika zvikuru. Zvinogona kuonekwa kuti yakawanda ye coating inoumbwa neSiC grains (inenge 4μm muhukuru), asi mamwe ma fibrous SiC defects anowanikwawo, izvo zvinoratidza kuti kuchine kukura kweSiC munzira iyi, uye coating yacho haisati yanyatsosimba zvakakwana. Kana tembiricha yakwira kusvika 1100 ℃, zvinoonekwa kuti SiC coating yakakora kwazvo, uye ma fibrous SiC defects anyangarika zvachose. Coating yacho inoumbwa neSiC particles dzakaita semadonhwe dzine dhayamita yeinenge 5~10μm, dzakabatana zvakasimba. Pamusoro pema pieces acho pakaoma. Inoumbwa ne nano-scale SiC grains dzisingaverengeki. Kutaura zvazviri, maitiro ekukura kweCVD-SiC pa1100 ℃ ave kudzorwa nehukuru. Mamorekuru madiki anonamirwa pamusoro pe substrate ane simba rakakwana nenguva yekukura kuita SiC grains. SiC grains dzinoumba madonhwe makuru zvakafanana. Pasi pesimba repamusoro, madonhwe mazhinji anoita seakaita sedenderedzwa, uye madonhwe acho anobatanidzwa zvakasimba kuti agadzire SiC coating yakakora. Kana tembiricha yakwira kusvika pa1200℃, SiC coating inenge yakakorawo, asi chimiro cheSiC chinova nemaburi akawanda uye pamusoro pecoating inoita kunge yakaoma. Kana tembiricha yawedzera kusvika pa1300℃, huwandu hwakawanda hwezvimedu zvakatenderera zvine dhayamita inosvika 3μm zvinowanikwa pamusoro pegrafiti substrate. Izvi zvinodaro nekuti patembiricha iyi, SiC yakashandurwa kuita gas phase nucleation, uye MTS decomposition rate inokurumidza zvikuru. Mamorekuru madiki aita reaction uye nucleated kuti aumbe SiC grains dzisati dzanyudzwa pamusoro pesubstrate. Mushure mekunge zvimedu zvaita spherical particles, zvinowira pasi, zvichizoguma neSiC particle coating isina kusimba. Zviri pachena kuti 1300℃ haigone kushandiswa sechimiro chekupisa kwe dense SiC coating. Kuenzanisa kwakazara kunoratidza kuti kana dense SiC coating ichizogadzirwa, tembiricha yakanaka yeCVD deposition i1100℃.
Mufananidzo 3 unoratidza mwero wekuiswa kweCVD SiC coatings patembiricha dzakasiyana dzekuiswa. Sezvo tembiricha yekuiswa ichiwedzera, mwero wekuiswa kweSiC coating unodzikira zvishoma nezvishoma. Mwero wekuiswa pa900°C i0.352 mg·h-1/mm2, uye kukura kwefibers kunotungamira kune mwero wekuiswa nekukurumidza. Mwero wekuiswa kwecoating ine density yakanyanya i0.179 mg·h-1/mm2. Nekuda kwekuiswa kwezvimwe zvikamu zveSiC, mwero wekuiswa pa1300°C ndiwo wakaderera, 0.027 mg·h-1/mm2 chete. Mhedziso: Tembiricha yepamusoro yeCVD deposition i1100℃. Tembiricha yakaderera inokurudzira kukura kweSiC zvakananga, nepo tembiricha yepamusoro ichikonzera kuti SiC ibudise utsi uye zvichikonzera kuvharwa kushoma. Nekuwedzera kwetembiricha yedeposition, mwero wedeposition weKuputira kweCVD SiCzvishoma nezvishoma zvinoderera.
Nguva yekutumira: Chivabvu-26-2025