Mune iyo silicon carbide imwe chete yekristaro yekukura maitiro, yemuviri mhute yekufambisa ndiyo yazvino nzira yekusimudzira maindasitiri. YePVT nzira yekukura,silicon carbide podaine simba guru pakukura. All parameters yesilicon carbide podainokanganisa zvakananga kunaka kwekrisiti imwe chete kukura uye magetsi emagetsi. Mumazuva ano maindasitiri ekushandisa, anowanzo shandiswasilicon carbide podasynthesis process ndiyo inozviparidzira yakakwirira-tembiricha synthesis nzira.
Iyo yekuzviparira yekudziya-yepamusoro-tembiricha synthesis nzira inoshandisa tembiricha yepamusoro kuti ipe mareactants kupisa kwekutanga kuti atange kuita kemikari, uye yobva yashandisa yayo yega kemikari inodziya kupisa kuti ibvumire zvinhu zvisingaite kuti zvienderere kupedzisa kemikari. Nekudaro, sezvo kemikari yeSi neC inoburitsa kupisa kushoma, zvimwe zvinogadzirisa zvinofanirwa kuwedzerwa kuchengetedza kuita. Naizvozvo, nyanzvi zhinji dzakaronga nzira yakavandudzwa yekuzviparira pahwaro uhwu, kuunza activator. Iyo yekuzviparadzira nzira iri nyore kuita, uye akasiyana masisitimu paramita ari nyore kudzora akadzikama. Huru-hukuru synthesis inosangana nezvinodiwa zveindasitiri.
Kare muna 1999, Bridgeport yakashandisa nzira yekuzviparidzira yakakwirira-tembiricha synthesis kugadzira.SiC hupfu, asi yakashandisa ethoxysilane nephenol resin sezvinhu zvakabikwa, izvo zvaidhura. Gao Pan nevamwe vakashandisa yakakwira-kuchena Si hupfu uye C hupfu semidziyo yekugadziraSiC hupfunekuita kwepamusoro-tembiricha mumhepo ye argon. Ning Lina akagadzirira hombe-chidimbuSiC hupfuby secondary synthesis.
Iyo yepakati-frequency induction yekudziisa choto chakagadzirwa neSecond Research Institute yeChina Electronics Technology Group Corporation inosanganisa zvakaenzana silicon poda uye kabhoni poda mune imwe stoichiometric reshiyo uye inozviisa mugirafu crucible. Thegraphite crucibleinoiswa mune yepakati-frequency induction yekudziya moto yekudziya, uye tembiricha shanduko inoshandiswa kugadzira uye kushandura yakaderera-tembiricha chikamu uye yakakwirira-tembiricha chikamu silicon carbide zvichiteerana. Sezvo tembiricha yeiyo β-SiC synthesis reaction mune yakaderera-tembiricha chikamu yakaderera pane inovhuvhuta tembiricha yeSi, iyo synthesis ye β-SiC pasi yakakwira vacuum inogona kunyatso kuvimbisa kuzviparira. Iyo nzira yekuunza argon, hydrogen uye HCl gasi mune synthesis yealpha-SiC inodzivirira kuparara kwe.SiC hupfumuchikamu chepamusoro-chepamusoro, uye inogona kuderedza zvinobudirira zvinyorwa zve nitrogen mu α-SiC powder.
Shandong Tianyue akagadzira choto chekubatanidza, achishandisa silane gasi sesilicon raw material uye kabhoni poda se carbon raw material. Huwandu hwegasi remafuta akaunzwa hwakagadziridzwa nembiri-nhanho synthesis nzira, uye yekupedzisira synthesized silicon carbide particle size yaive pakati pe50 ne5 000 um.
1 Kudzora zvinhu zvehupfu synthesis process
1.1 Mhedzisiro yehupfu particle size pakukura kwekristaro
Iyo particle size yesilicon carbide poda ine simba rakakosha pane inotevera imwe crystal kukura. Kukura kweSiC single crystal nePVT nzira inonyanya kuwanikwa nekushandura molar ratio yesilicon uye kabhoni mune gasi chikamu chikamu, uye molar chiyero chesilicon nekabhoni muchikamu chegasi chine hukama nekukura kwesilicon carbide poda. . Iyo yakazara kudzvinyirirwa uye silicon-kabhoni reshiyo yekukura sisitimu inowedzera nekudzikira kwechikamu chehukuru. Kana saizi yechikamu ichidzikira kubva pa2-3 mm kusvika 0.06 mm, chiyero chesilicon-kabhoni chinowedzera kubva pa1.3 kusvika 4.0. Kana zvimedu zvidiki kune imwe nhanho, iyo Si chikamu chinomanikidza chinowedzera, uye chidimbu cheSi firimu chinoumbwa pamusoro peiyo inokura kristaro, ichiita gasi-mvura-yakasimba-yakasimba kukura, iyo inokanganisa iyo polymorphism, point defect uye mutsara urema. mukristaro. Naizvozvo, iyo particle size ye-high-purity silicon carbide poda inofanira kudzorwa zvakanaka.
Mukuwedzera, kana ukuru hweSiC hupfu hushoma hushoma, hupfu hunoora nokukurumidza, zvichiita kuti kukura kwakanyanya kweSiC single crystals. Kune rumwe rutivi, munzvimbo yepamusoro-yekushisa yeSiC single crystal kukura, maitiro maviri ekugadzirisa uye kuora anoitwa panguva imwe chete. Silicon carbide powder ichaora uye inogadzira kabhoni muchikamu chegasi uye chikamu chakasimba chakadai seSi, Si2C, SiC2, zvichiita kuti carbonization yakakomba yepolycrystalline powder uye kuumbwa kwekabhoni inclusions mukriststal; kune rumwe rutivi, kana chiyero chekuparara kwehupfu chiri kukurumidza kukurumidza, chimiro chekristal cheSiC single crystal inoshanduka kuchinja, zvichiita kuti zvive zvakaoma kudzora kunaka kweSiC imwe chete yekrisiti.
1.2 Mhedzisiro yehupfu hwekristaro fomu pakukura kwekristaro
Kukura kweSiC single crystal nePVT nzira ndeye sublimation-recrystallization process pakupisa kwakanyanya. Iyo yekristaro fomu yeSiC mbishi zvinhu ine yakakosha pesvedzero pakukura kwekristaro. Mukuita kwehupfu hwehupfu, iyo yakaderera-temperature synthesis phase (β-SiC) ine cubic chimiro che unit cell uye yakakwirira-temperature synthesis phase (α-SiC) ine hexagonal chimiro cheyuniti cell ichanyanya kugadzirwa. . Kune akawanda silicon carbide crystal mafomu uye yakamanikana tembiricha yekudzora renji. Semuenzaniso, 3C-SiC inoshandura kuita hexagonal silicon carbide polymorph, kureva 4H/6H-SiC, patembiricha iri pamusoro pe1900°C.
Munguva yekukura kwekristal imwe chete, apo β-SiC powder inoshandiswa kukura makristasi, iyo silicon-carbon molar ratio yakakura kudarika 5.5, nepo α-SiC powder inoshandiswa kukura makristasi, iyo silicon-carbon molar ratio ndeye 1.2. Kana kutonhora kuchikwira, shanduko yechikamu inoitika mucrucible. Panguva ino, chiyero chemolar muchikamu chegasi chinova chakakura, chisingakodzeri kukura kwekristaro. Uye zvakare, mamwe gasi chikamu kusvibiswa, kusanganisira kabhoni, silicon, uye silicon dioxide, inogadzirwa nyore panguva yekuchinja kwechikamu. Kuvapo kwetsvina iyi kunoita kuti kristaro ibereke mamicrotubes uye voids. Nokudaro, fomu yekristal yehupfu inofanira kunyatsodzorwa.
1.3 Mhedzisiro yehupfu hutsvina pakukura kwekristaro
Izvo zvisina kuchena zviri muSiC poda inokanganisa iyo inongoerekana yavapo nucleation panguva yekukura kwekristaro. Iyo yakakwirira yekusachena kwemukati, kashoma kuti iite kuti kristaro iite nucleate yega. Kune SiC, iyo huru yesimbi tsvina inosanganisira B, Al, V, uye Ni, iyo inogona kuunzwa nekugadzirisa maturusi panguva yekugadziriswa kwesilicon poda uye kabhoni poda. Pakati pavo, B uye Al ndiwo akanyanya kudzika nhanho yesimba yekugamuchira tsvina muSiC, zvichikonzera kudzikira kweSiC resistivity. Kumwe kusvibiswa kwesimbi kuchaunza huwandu hwesimba, zvichikonzera kusagadzikana kwemagetsi eSiC single crystals pakupisa kwakanyanya, uye kuve nekukanganisa kukuru pamagetsi emhando yepamusoro-kuchena semi-insulating single crystal substrates, kunyanya iyo resistivity. Naizvozvo, yakakwirira-kuchena silicon carbide poda inofanira kugadzirwa zvakanyanya sezvinobvira.
1.4 Mhedzisiro yenitrogen yemukati muhupfu pakukura kwekristaro
Iyo nhanho yenitrogen yemukati inogadzirisa iyo resistivity yeimwe crystal substrate. Vagadziri vakakura vanofanirwa kugadzirisa iyo nitrogen doping yekumisikidza mune yekugadzira zvinhu zvinoenderana neyakakura kristaro kukura maitiro panguva yehupfu synthesis. High-purity semi-insulating silicon carbide single crystal substrates ndiyo inonyanya kuvimbisa zvinhu zvemauto epakati emagetsi zvikamu. Kuti ukure yakakwirira-kuchena semi-insulating single crystal substrates ine yakakwirira resistivity uye yakanakisa magetsi emagetsi, zviri mukati meiyo huru yekusachena nitrogen mu substrate inofanira kudzorwa pamwero wakaderera. Conductive single crystal substrates inoda kuti nitrogen yemukati idzorerwe pane yakawandisa.
2 Kiyi yekudzora tekinoroji yehupfu synthesis
Nekuda kwenzvimbo dzakasiyana dzekushandisa dzesilicon carbide substrates, tekinoroji yekugadzira yekukura hupfu zvakare ine maitiro akasiyana. Kune N-mhando conductive single crystal kukura poda, kuchena kwepamusoro kuchena uye chikamu chimwe chete chinodiwa; nepo kune semi-insulating imwe yekristaro kukura poda, kudzora kwakasimba kwenitrogen yemukati kunodiwa.
2.1 Powder particle size control
2.1.1 Synthesis tembiricha
Kuchengeta mamwe maitiro asina kuchinjwa, SiC poda inogadzirwa patembiricha ye1900 ℃, 2000 ℃, 2100 ℃, uye 2200 ℃ yakatorwa uye yakaongororwa. Sezvinoratidzwa muFigure 1, zvinogona kuonekwa kuti saizi yepakati i250 ~ 600 μm pa1900 ℃, uye saizi yechikamu inowedzera kusvika 600 ~ 850 μm pa2000 ℃, uye saizi yechikamu inoshanduka zvakanyanya. Kana tembiricha ikaramba ichikwira kusvika pa2100 ℃, saizi yeSiC poda i850 ~ 2360 μm, uye kuwedzera kunowanzo kuve kwakapfava. Iyo particle size yeSiC pa2200 ℃ yakagadzikana pa2360 μm. Kuwedzera kwekushisa kwekutanga kubva ku1900 ℃ kune mhedzisiro yakanaka paSiC particle size. Kana tembiricha yekubatanidza ikaramba ichiwedzera kubva pa2100 ℃, saizi yechidimbu haichachinji zvakanyanya. Naizvozvo, kana tembiricha yekubatanidza ikaiswa ku2100 ℃, saizi yakakura inogona kugadzirwa pane yakaderera simba rekushandisa.
2.1.2 Nguva yekubatanidza
Mamwe maitiro ekugadzirisa anoramba asina kuchinjwa, uye nguva yekubatanidza inoiswa ku4 h, 8 h, uye 12 h zvakateerana. Iyo yakagadzirwa SiC powder sampling analysis inoratidzwa muMufananidzo 2. Inowanikwa kuti nguva yekubatanidza ine simba guru pakukura kweSiC. Kana nguva yekubatanidza iri 4 h, saizi yechikamu inonyanya kugoverwa pa200 μm; kana nguva yekubatanidza iri 8 h, iyo synthetic particle size inowedzera zvakanyanya, inonyanya kugoverwa paanenge 1 000 μm; sezvo nguva yekubatanidza inoramba ichiwedzera, saizi yepakati inowedzera kuwedzera, inonyanya kugoverwa panenge 2 000 μm.
2.1.3 Kupesvedzerwa kwesaizi yezvimedu
Sezvo iyo yekumba silicon zvinhu zvekugadzira cheni inovandudzwa zvishoma nezvishoma, kuchena kwezvinhu zvesilicon zvakare kunovandudzwa. Parizvino, zvinhu zvesilicon zvinoshandiswa mukugadzira zvinonyanya kukamurwa kuita granular silicon uye silicon yehupfu, sezvakaratidzwa mumufananidzo 3.
Yakasiyana silicon mbishi zvinhu zvakashandiswa kuita silicon carbide synthesis kuyedza. Kuenzanisa kwezvigadzirwa zvekugadzira kunoratidzwa muMufananidzo 4. Kuongorora kunoratidza kuti kana uchishandisa block silicon raw materials, yakawanda yeSi zvinhu zviripo muchigadzirwa. Mushure mekunge silicon block yapwanywa kechipiri, iyo Si element mune yekugadzira chigadzirwa yakaderedzwa zvakanyanya, asi ichiripo. Chekupedzisira, silicon poda inoshandiswa kugadzira, uye chete SiC iripo muchigadzirwa. Izvi zvinodaro nekuti mukugadzira, hombe-saizi granular silicon inoda kutarisana nepamusoro synthesis reaction kutanga, uye silicon carbide inogadzirwa pamusoro, iyo inodzivirira iyo yemukati Si poda kubva pakuwedzera kusanganiswa neC poda. Naizvozvo, kana block silicon ichishandiswa seyakagadzirwa zvinhu, inoda kupwanywa uye yobva yaiswa kune yechipiri synthesis process kuti iwane silicon carbide poda yekukura kwekristaro.
2.2 Powder crystal fomu kutonga
2.2.1 Pesvedzero yetembiricha ye synthesis
Kuchengeta mamwe maitiro asina kuchinjwa, tembiricha yekubatanidza i1500 ℃, 1700 ℃, 1900 ℃, uye 2100 ℃, uye iyo yakagadzirwa SiC poda inotorwa uye kuongororwa. Sezvinoratidzwa mumufananidzo 5, β-SiC ndeyevhu yero, uye α-SiC yakareruka muruvara. Nekutarisa ruvara uye morphology yehupfu hwakagadzirwa, zvinogona kutariswa kuti chigadzirwa chakagadzirwa chiri β-SiC patembiricha ye1500 ℃ uye 1700 ℃. Pa1900 ℃, ruvara runova chiedza, uye hexagonal zvimedu zvinoonekwa, zvichiratidza kuti mushure mokunge tembiricha yakwira kusvika 1900 ℃, shanduko yechikamu inoitika, uye chikamu che β-SiC chinoshandurwa kuita α-SiC; kana tembiricha ichiramba ichikwira kusvika 2100 ℃, inowanikwa kuti masynthesized particles ari pachena, uye α-SiC yakashandurwa chaizvo.
2.2.2 Mhedzisiro yenguva yekubatanidza
Mamwe maitiro ekugadzirisa anoramba asina kuchinjwa, uye nguva yekubatanidza inoiswa ku4h, 8h, uye 12h, zvichiteerana. Iyo yakagadzirwa SiC poda inotorwa uye inoongororwa ne diffractometer (XRD). Zvigumisiro zvinoratidzwa muMufananidzo 6. Nguva yekubatanidza ine imwe simba pane chigadzirwa chakagadzirwa neSiC powder. Kana nguva yekubatanidza iri 4 h uye 8 h, chigadzirwa chekugadzira chinonyanya 6H-SiC; apo nguva yekubatanidza iri 12 h, 15R-SiC inooneka muchigadzirwa.
2.2.3 Pesvedzero yereshiyo yezvakagadzirwa
Mamwe maitiro anoramba asina kuchinjika, huwandu hwesilicon-kabhoni zvinhu zvinoongororwa, uye zviyero ndeye 1.00, 1.05, 1.10 uye 1.15 zvakateerana kune synthesis miedzo. Migumisiro inoratidzwa mumufananidzo 7.
Kubva pa XRD spectrum, zvinogona kuonekwa kuti kana silicon-carbon ratio yakakura kudarika 1.05, Si yakawandisa inooneka muchigadzirwa, uye kana silicon-carbon ratio iri pasi pe1.05, yakawandisa C inooneka. Kana iyo silicon-kabhoni reshiyo iri 1.05, iyo yemahara kabhoni muchigadzirwa chekugadzira inobviswa, uye hapana yemahara silicon inooneka. Naizvozvo, huwandu hwechiyero chesilicon-kabhoni reshiyo inofanira kunge iri 1.05 kuti igadzire yakakwira-kuchena SiC.
2.3 Kudzora kwepasi nitrogen content muupfu
2.3.1 Synthetic raw materials
Zvinhu zvakashandiswa mukuedza uku ndezvepamusoro-kuchena kabhoni poda uye yakakwirira-kuchena silicon poda ine dhayamita yepakati ye20 μm. Nekuda kwehukuru hwadzo hudiki uye yakakura chaiyo nzvimbo, zviri nyore kutora N2 mumhepo. Paunenge uchigadzira hupfu, huchaunzwa muchimiro chekristaro chehupfu. Nekukura kweN-mhando makristasi, iyo isina kuenzana doping yeN2 muupfu inotungamirira kusaenzana kushorwa kwekristaro uye kunyange shanduko muchimiro chekristaro. Iyo nitrogen yehupfu hwakagadzirwa mushure mekunge hydrogen yaunzwa yakadzikira zvakanyanya. Izvi zvinodaro nekuti vhoriyamu yehydrogen mamorekuru idiki. Kana iyo N2 yakashambadzirwa mucarbon powder uye silicon poda inopisa uye yakaora kubva pamusoro, H2 inopararira zvakakwana mumukana uri pakati pehupfu nehuduku hwayo, kutsiva nzvimbo yeN2, uye N2 inopukunyuka kubva kune crucible panguva yekutsvaira, kuzadzisa chinangwa chekubvisa nitrogen yemukati.
2.3.2 Synthesis process
Munguva yekugadzirwa kwesilicon carbide poda, sezvo radius yekabhoni maatomu uye maatomu enitrogen akafanana, nitrogen inotsiva kabhoni vacancies musilicon carbide, nokudaro kuwedzera nitrogen zvirimo. Iyi nzira yekuyedza inotora nzira yekuunza H2, uye H2 inopindirana nekabhoni uye silicon zvinhu mune synthesis crucible kugadzira C2H2, C2H, uye SiH magasi. Iyo kabhoni element yemukati inowedzera kuburikidza negasi chikamu chekufambisa, nekudaro ichidzikisa kabhoni vacancies. Chinangwa chekubvisa nitrogen chinowanikwa.
2.3.3 Gadzirisa mamiriro enitrogen content control
Graphite crucibles ine hombe porosity inogona kushandiswa sekuwedzera C masosi kutora Si mhute mune gasi chikamu zvikamu, kuderedza Si muchikamu chegasi, uye nekudaro kuwedzera C / Si. Panguva imwecheteyo, ma graphite crucibles anogona kuitawo neSi atmosphere kugadzira Si2C, SiC2 uye SiC, iyo yakaenzana neSi atmosphere inounza C sosi kubva kugraphite crucible mumhepo yekukura, ichiwedzera chiyero cheC, uye zvakare kuwedzera kabhoni-silicon ratio. . Naizvozvo, iyo kabhoni-silicon ratio inogona kuwedzerwa nekushandisa graphite crucibles ine hombe porosity, kuderedza kabhoni vacancies, uye kuzadzisa chinangwa chekubvisa nitrogen.
3 Ongororo uye dhizaini yeimwe crystal poda synthesis process
3.1 Nheyo uye dhizaini ye synthesis process
Kuburikidza nechataurwa pamusoro apa chidzidzo chakazara pamusoro pekutonga kweiyo particle size, crystal fomu uye nitrogen yemukati yehupfu synthesis, nzira yekubatanidza inotsanangurwa. Yakakwirira-kuchena C poda uye Si powder inosarudzwa, uye inosanganiswa zvakaenzana uye inotakurwa mugirafu crucible maererano nesilicon-carbon ratio ye1.05. Matanho ekuita akapatsanurwa kuita nhanho ina:
1) Yakadzika-tembiricha denitrification process, vacuuming kusvika 5 × 10-4 Pa, ipapo kuunza hydrogen, ichiita kuti kamuri yekumanikidza inenge 80 kPa, ichichengetedza 15 min, uye kudzokorora kana. Iyi nzira inogona kubvisa zvinhu zve nitrogen pamusoro pekabhoni poda uye silicon poda.
2) High-temperature denitrification process, vacuuming kusvika 5 × 10-4 Pa, wozopisa kusvika 950 ℃, uyezve kuunza hydrogen, ichiita kuti kamuri yekumanikidza inenge 80 kPa, kuchengetedza 15 min, uye kudzokorora kana. Izvi zvinogona kubvisa zvinhu zvenitrogen pamusoro pekabhoni poda uye silicon poda, uye kutyaira nitrogen munzvimbo yekupisa.
3) Synthesis yeyakadzika tembiricha chikamu process, bvisa ku 5 × 10-4 Pa, wozopisa kusvika 1350 ℃, chengeta kwemaawa gumi nemaviri, wobva wasuma hydrogen kuita kamuri yekumanikidza nezve 80 kPa, chengeta kweawa imwe. Iyi nzira inogona kubvisa iyo nitrogen yakasvibiswa panguva yekugadzira.
4) Synthesis yeyakanyanya tembiricha chikamu process, zadza neimwe gasi vhoriyamu kuyerera reshiyo yekuchena yakakwira hydrogen uye argon yakasanganiswa gasi, ita kamuri yekumanikidza inenge 80 kPa, simudza tembiricha kusvika 2100 ℃, chengeta kwemaawa gumi. Iyi nzira inopedzisa shanduko yesilicon carbide poda kubva ku β-SiC kuenda ku α-SiC uye inopedzisa kukura kwekristaro zvidimbu.
Pakupedzisira, mirira kuti tembiricha yekamuri itonhore kusvika kukamuri tembiricha, zadza kumhepo yemhepo, uye bvisa hupfu.
3.2 Powder post-processing process
Mushure mekunge hupfu hwagadzirwa nemaitiro ari pamusoro, inofanirwa kugadziridzwa-kubvisa yemahara kabhoni, silicon uye kumwe kusvibiswa kwesimbi uye kuvheneka saizi yechikamu. Kutanga, hupfu hwakagadzirwa hunoiswa muguyo rebhora rekupwanya, uye yakapwanyika silicon carbide poda inoiswa mumoto wemoto uye inopisa kusvika 450 ° C neokisijeni. Iyo yakasununguka kabhoni muupfu inosanganiswa nekupisa kuti ibudise kabhoni dhaimoni gasi inopukunyuka kubva mukamuri, nokudaro inowana kubviswa kwemahara kabhoni. Mushure meizvozvo, iyo acidic yekuchenesa mvura inogadzirwa uye inoiswa musilicon carbide particle yekuchenesa muchina wekuchenesa kubvisa kabhoni, silicon uye yakasara tsvina yesimbi inogadzirwa panguva yekugadzira. Mushure meizvozvo, iyo yakasara asidhi inoshambidzwa mumvura yakachena uye yakaomeswa. Iyo yakaomeswa poda inotariswa mune inovibrate skrini yekusarudze saizi yechikamu chekukura kwekristaro.
Nguva yekutumira: Aug-08-2024