Choyamba, kapangidwe ndi katundu wa SiC crystal.
SiC ndi gulu la binary lomwe limapangidwa ndi Si element ndi C element mu chiŵerengero cha 1: 1, ndiko kuti, 50% silicon (Si) ndi 50% carbon (C), ndipo gawo lake loyambirira ndi SI-C tetrahedron.
Chithunzi chojambula cha silicon carbide tetrahedron kapangidwe
Mwachitsanzo, ma atomu a Si ndi aakulu m’mimba mwake, ofanana ndi apulo, ndipo maatomu a C ndi ang’onoang’ono m’mimba mwake, mofanana ndi lalanje, ndipo chiwerengero chofanana cha malalanje ndi maapulo amawunjika pamodzi kuti apange kristalo wa SiC.
SiC ndi Binary compound, momwe Si-Si bond spacing atomu ndi 3.89 A, mungamvetse bwanji kusiyana kumeneku?Pakali pano, makina abwino kwambiri a lithography pamsika ali ndi kulondola kwa 3nm, komwe kuli mtunda wa 30A, ndipo kulondola kwa lithography ndi nthawi 8 kuposa mtunda wa atomiki.
Mphamvu ya Si-Si ndi 310 kJ / mol, kotero mutha kumvetsetsa kuti mphamvu ya mgwirizano ndi mphamvu yomwe imakoka maatomu awiriwa, ndipo mphamvu yowonjezera yowonjezera, mphamvu yowonjezera yomwe mukufunikira kuti muyike.
Mwachitsanzo, ma atomu a Si ndi aakulu m’mimba mwake, ofanana ndi apulo, ndipo maatomu a C ndi ang’onoang’ono m’mimba mwake, mofanana ndi lalanje, ndipo chiwerengero chofanana cha malalanje ndi maapulo amawunjika pamodzi kuti apange kristalo wa SiC.
SiC ndi Binary compound, momwe Si-Si bond spacing atomu ndi 3.89 A, mungamvetse bwanji kusiyana kumeneku?Pakali pano, makina abwino kwambiri a lithography pamsika ali ndi kulondola kwa 3nm, komwe kuli mtunda wa 30A, ndipo kulondola kwa lithography ndi nthawi 8 kuposa mtunda wa atomiki.
Mphamvu ya Si-Si ndi 310 kJ / mol, kotero mutha kumvetsetsa kuti mphamvu ya mgwirizano ndi mphamvu yomwe imakoka maatomu awiriwa, ndipo mphamvu yowonjezera yowonjezera, mphamvu yowonjezera yomwe mukufunikira kuti muyike.
Chithunzi chojambula cha silicon carbide tetrahedron kapangidwe
Mwachitsanzo, ma atomu a Si ndi aakulu m’mimba mwake, ofanana ndi apulo, ndipo maatomu a C ndi ang’onoang’ono m’mimba mwake, mofanana ndi lalanje, ndipo chiwerengero chofanana cha malalanje ndi maapulo amawunjika pamodzi kuti apange kristalo wa SiC.
SiC ndi Binary compound, momwe Si-Si bond spacing atomu ndi 3.89 A, mungamvetse bwanji kusiyana kumeneku?Pakali pano, makina abwino kwambiri a lithography pamsika ali ndi kulondola kwa 3nm, komwe kuli mtunda wa 30A, ndipo kulondola kwa lithography ndi nthawi 8 kuposa mtunda wa atomiki.
Mphamvu ya Si-Si ndi 310 kJ / mol, kotero mutha kumvetsetsa kuti mphamvu ya mgwirizano ndi mphamvu yomwe imakoka maatomu awiriwa, ndipo mphamvu yowonjezera yowonjezera, mphamvu yowonjezera yomwe mukufunikira kuti muyike.
Mwachitsanzo, ma atomu a Si ndi aakulu m’mimba mwake, ofanana ndi apulo, ndipo maatomu a C ndi ang’onoang’ono m’mimba mwake, mofanana ndi lalanje, ndipo chiwerengero chofanana cha malalanje ndi maapulo amawunjika pamodzi kuti apange kristalo wa SiC.
SiC ndi Binary compound, momwe Si-Si bond spacing atomu ndi 3.89 A, mungamvetse bwanji kusiyana kumeneku?Pakali pano, makina abwino kwambiri a lithography pamsika ali ndi kulondola kwa 3nm, komwe kuli mtunda wa 30A, ndipo kulondola kwa lithography ndi nthawi 8 kuposa mtunda wa atomiki.
Mphamvu ya Si-Si ndi 310 kJ / mol, kotero mutha kumvetsetsa kuti mphamvu ya mgwirizano ndi mphamvu yomwe imakoka maatomu awiriwa, ndipo mphamvu yowonjezera yowonjezera, mphamvu yowonjezera yomwe mukufunikira kuti muyike.
Tikudziwa kuti chinthu chilichonse chimapangidwa ndi maatomu, ndipo mawonekedwe a kristalo ndi dongosolo lokhazikika la ma atomu, lomwe limatchedwa dongosolo lautali, monga zotsatirazi.Chigawo chaching'ono kwambiri cha kristalo chimatchedwa selo, ngati selo ili ndi mawonekedwe a cubic, imatchedwa cubic yodzaza kwambiri, ndipo selo ili ndi hexagonal, imatchedwa kuti pafupi ndi hexagonal.
Mitundu ya kristalo wamba ya SiC imaphatikizapo 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, ndi zina zotero.
Pakati pawo, mndandanda woyambira wa 4H-SiC ndi ABCB... ;Mndandanda woyambira wa 6H-SiC ndi ABCACB... ;Mndandanda woyambira wa 15R-SiC ndi ABCACBCABACABCB... .
Izi zitha kuwoneka ngati njerwa zomangira nyumba, zina mwa njerwa zanyumba zili ndi njira zitatu zoyikira, zina zili ndi njira zinayi zoyikira, zina zimakhala ndi njira zisanu ndi chimodzi.
Magawo oyambira amtundu wa SiC crystal wamtunduwu akuwonetsedwa patebulo:
Kodi a, b, c ndi ngodya amatanthauza chiyani?Kapangidwe ka cell kakang'ono kwambiri mu SiC semiconductor akufotokozedwa motere:
Pankhani ya selo lomwelo, mawonekedwe a kristalo adzakhalanso osiyana, izi zili ngati timagula lottery, nambala yopambana ndi 1, 2, 3, munagula 1, 2, 3 nambala zitatu, koma ngati nambala yasankhidwa. mosiyana, ndalama zopambana ndizosiyana, kotero chiwerengero ndi dongosolo la kristalo lomwelo, likhoza kutchedwa kristalo yemweyo.
Chithunzi chotsatirachi chikuwonetsa mitundu iwiri ya stacking, kusiyana kokha mumayendedwe a stacking a maatomu apamwamba, mawonekedwe a kristalo ndi osiyana.
Mapangidwe a kristalo opangidwa ndi SiC amagwirizana kwambiri ndi kutentha.Pansi pa kutentha kwakukulu kwa 1900 ~ 2000 ℃, 3C-SiC pang'onopang'ono idzasintha kukhala hexagonal SiC polyform monga 6H-SiC chifukwa chosakhazikika bwino.Ndi chifukwa cha kugwirizana kwakukulu pakati pa kuthekera kwa mapangidwe a polymorphs a SiC ndi kutentha, ndi kusakhazikika kwa 3C-SiC palokha, kukula kwa 3C-SiC kumakhala kovuta, ndipo kukonzekera kumakhala kovuta.Dongosolo la hexagonal la 4H-SiC ndi 6H-SiC ndilofala kwambiri komanso losavuta kukonzekera, ndipo amaphunzira kwambiri chifukwa cha makhalidwe awo.
Kutalika kwa mgwirizano wa SI-C chomangira mu SiC crystal ndi 1.89A yokha, koma mphamvu yomangiriza ndi yokwera kwambiri ngati 4.53eV.Choncho, kusiyana kwa mphamvu pakati pa dziko logwirizana ndi dziko lotsutsana ndi mgwirizano ndi lalikulu kwambiri, ndipo kusiyana kwakukulu kwa gulu kungapangidwe, komwe kumakhala kangapo kwa Si ndi GaAs.Kuchuluka kwa kusiyana kwa bandi kumatanthauza kuti mawonekedwe a kristalo wotentha kwambiri ndi okhazikika.Mphamvu zamagetsi zamagetsi zomwe zimagwirizana zimatha kuzindikira mawonekedwe a magwiridwe antchito okhazikika pamatenthedwe apamwamba komanso mawonekedwe osavuta ochotsera kutentha.
Kumangirira kolimba kwa chomangira cha Si-C kumapangitsa kuti lattice ikhale ndi kugwedezeka kwakukulu, ndiko kuti, phononi yamphamvu kwambiri, kutanthauza kuti kristalo wa SiC uli ndi kayendedwe ka ma elekitironi ochuluka komanso kukhathamiritsa kwamafuta, ndipo zida zamagetsi zamagetsi zofananira zimakhala ndi liwiro losinthasintha komanso kudalirika, zomwe zimachepetsa chiopsezo cha kulephera kwa kutentha kwa chipangizocho.Kuphatikiza apo, kulimba kwamphamvu kwa SiC kumapangitsa kuti ikwaniritse kuchuluka kwa ma doping ndikuchepetsa kukana.
Chachiwiri, mbiri ya SiC crystal chitukuko
Mu 1905, Dr. Henri Moissan anapeza kristalo wachilengedwe wa SiC m'chigwachi, chomwe adachipeza chofanana ndi diamondi ndipo adachitcha diamondi ya Mosan.
Ndipotu, kumayambiriro kwa 1885, Acheson adapeza SiC posakaniza coke ndi silika ndikuwotcha mu ng'anjo yamagetsi.Pa nthawiyo, anthu ankaganiza kuti ndi miyala ya diamondi yosakanikirana ndipo ankaitcha emery.
Mu 1892, Acheson adakonza njira yophatikizira, adasakaniza mchenga wa quartz, coke, timitengo tating'ono tamatabwa ndi NaCl, ndikutenthetsa mung'anjo yamagetsi yamagetsi mpaka 2700 ℃, ndipo adapeza bwino makristalo a SiC.Njira iyi yopangira makristasi a SiC imadziwika kuti njira ya Acheson ndipo akadali njira yayikulu yopangira ma abrasives a SiC m'makampani.Chifukwa cha chiyero chochepa cha zopangira zopangira komanso kuphatikizika koyipa, njira ya Acheson imapanga zonyansa zambiri za SiC, kukhulupirika kwa kristalo komanso m'mimba mwake yaying'ono ya kristalo, zomwe zimakhala zovuta kukwaniritsa zofunikira zamakampani opanga ma semiconductor kukula kwakukulu, chiyero chapamwamba komanso chapamwamba. -makristali apamwamba, ndipo sangathe kugwiritsidwa ntchito popanga zida zamagetsi.
Lely wa Philips Laboratory anakonza njira yatsopano yopangira makristasi a SiC single mu 1955. Mu njira iyi, graphite crucible imagwiritsidwa ntchito ngati chotengera cha kukula, SiC powder crystal imagwiritsidwa ntchito ngati zopangira kukula kwa SiC crystal, ndipo porous graphite imagwiritsidwa ntchito kudzipatula. malo opanda kanthu kuchokera pakati pa zopangira zokulirapo.Akamakula, graphite crucible imatenthedwa mpaka 2500 ℃ pansi pa mlengalenga wa Ar kapena H2, ndipo zotumphukira za SiC ufa zimatsitsidwa ndikuwola kukhala zinthu za gawo la Si ndi C, ndipo kristalo wa SiC umakulira mkatikati mwa dzenje pambuyo pa mpweya. Kuthamanga kumafalikira kudzera mu porous graphite.
Chachitatu, SiC crystal kukula luso
Kukula kwa kristalo imodzi ya SiC ndikovuta chifukwa cha mawonekedwe ake.Izi makamaka chifukwa chakuti palibe gawo lamadzimadzi lomwe lili ndi chiŵerengero cha stoichiometric cha Si: C = 1: 1 pa kuthamanga kwamlengalenga, ndipo sichikhoza kukulitsidwa ndi njira zokulirapo zomwe zimagwiritsidwa ntchito ndi ndondomeko yamakono ya kukula kwa semiconductor. makampani - cZ njira, kugwa crucible njira ndi njira zina.Malinga ndi mawerengedwe ongoyerekeza, pokhapokha ngati kuthamanga kuli kokulirapo kuposa 10E5atm ndipo kutentha kuli kopitilira 3200 ℃, chiŵerengero cha stoichiometric cha Si: C = 1: 1 chingapezeke.Pofuna kuthana ndi vutoli, asayansi ayesetsa mosalekeza kuti apereke njira zosiyanasiyana zopezera makristasi apamwamba kwambiri, kukula kwakukulu komanso makristasi otsika mtengo a SiC.Pakalipano, njira zazikuluzikulu ndi njira ya PVT, njira yamadzimadzi ndi njira yopangira mpweya wotentha kwambiri.
Nthawi yotumiza: Jan-24-2024