Enqubweni yokukhula kwekristalu eyodwa ye-silicon carbide, ukuthuthwa komhwamuko ongokoqobo kuyindlela yamanje yokukhiqiza izimboni. Ngendlela yokukhula ye-PVT,i-silicon carbide powderinethonya elikhulu enqubweni yokukhula. Zonke izinhlaka zei-silicon carbide powderkuthinta ngqo ikhwalithi yokukhula kwekristalu elilodwa kanye nezakhiwo zikagesi. Ezisetshenzisweni zamanje zezimboni, okusetshenziswa kakhului-silicon carbide powderinqubo yokwenziwa iyindlela yokwenziwa yokwenziwa ekhula ngokushisa okuphezulu ezikhulisa ngokwayo.
Indlela yokwenziwa kwezinga lokushisa eliphezulu ezizikhulisayo isebenzisa izinga lokushisa eliphezulu ukunikeza ama-reactants ukushisa kokuqala ukuqala ukusabela kwamakhemikhali, bese isebenzisa ukushisa kwayo kokusabela kwamakhemikhali ukuvumela izinto ezingaphendulwanga ukuthi ziqhubeke nokuqedela ukusabela kwamakhemikhali. Kodwa-ke, njengoba ukusabela kwamakhemikhali kwe-Si ne-C kukhipha ukushisa okuncane, ezinye izinto ezisabelayo kumele zengezwe ukuze kugcinwe ukusabela. Ngakho-ke, izazi eziningi ziphakamise indlela yokwenziwa ezizikhulisayo ethuthukisiwe ngalesi sisekelo, zethula i-activator. Indlela yokuzikhulisa kulula ukuyisebenzisa, futhi amapharamitha ahlukahlukene okwenziwa kulula ukuwalawula ngokuzinzile. Ukwenziwa okukhulu kuhlangabezana nezidingo zokuthuthukiswa kwezimboni.
Kusukela ngo-1999, iBridgeport yasebenzisa indlela yokwakheka kwezinga lokushisa eliphezulu elizikhulisayo ukuze ikhiqizeImpuphu ye-SiC, kodwa yasebenzisa i-ethoxysilane kanye ne-phenol resin njengezinto zokusetshenziswa, okwakubiza kakhulu. I-Gao Pan nabanye basebenzisa i-Si powder ehlanzekile kakhulu kanye ne-C powder njengezinto zokusetshenziswa zokwenziwa.Impuphu ye-SiCngokusabela kokushisa okuphezulu emoyeni we-argon. UNing Lina walungisa izinhlayiya ezinkuluImpuphu ye-SiCngokuhlanganiswa kwesibili.
Isithando sokushisa esiphakathi nendawo esakhiwe yi-Second Research Institute of China Electronics Technology Group Corporation sixuba ngokulinganayo i-silicon powder ne-carbon powder ngesilinganiso esithile se-stoichiometric bese sizifaka endaweni yokushaqeka ye-graphite.isitsha sokubethela se-graphiteifakwa esithandweni sokushisa esiphakathi nendawo sokufakelwa ukuze kufudunyezwe, futhi ushintsho lokushisa lusetshenziselwa ukuhlanganisa nokuguqula isigaba sokushisa esiphansi kanye nesigaba sokushisa okuphezulu ngokulandelana. Njengoba izinga lokushisa lokusabela kokwenziwa kwe-β-SiC esigabeni sokushisa okuphansi liphansi kunezinga lokushisa lokuguquguquka kwe-Si, ukwenziwa kwe-β-SiC ngaphansi kwe-vacuum ephezulu kungaqinisekisa kahle ukuzisabalalisa. Indlela yokungenisa igesi ye-argon, i-hydrogen kanye ne-HCl ekwakhiweni kwe-α-SiC ivimbela ukubola kwe-Impuphu ye-SiCesigabeni sokushisa okuphezulu, futhi kunganciphisa ngempumelelo okuqukethwe yi-nitrogen ku-α-SiC powder.
I-Shandong Tianyue yaklama isithando sokwenziwa, isebenzisa igesi ye-silane njengezinto zokusetshenziswa ze-silicon kanye ne-carbon powder njengezinto zokusetshenziswa ze-carbon. Inani legesi yezinto zokusetshenziswa ezisetshenzisiwe lalungiswa ngendlela yokwenziwa kwezinyathelo ezimbili, kanti usayizi wokugcina wezinhlayiya ze-silicon carbide ezihlanganisiwe wawuphakathi kuka-50 no-5 000 um.
1 Izici zokulawula inqubo yokwenziwa kwempuphu
1.1 Umphumela wobukhulu bezinhlayiya zempuphu ekukhuleni kwekristalu
Usayizi wezinhlayiya zempuphu ye-silicon carbide unethonya elibaluleke kakhulu ekukhuleni kwekristalu eyodwa okulandelayo. Ukukhula kwekristalu eyodwa ye-SiC ngendlela ye-PVT kufezwa kakhulu ngokushintsha isilinganiso se-molar se-silicon ne-carbon engxenyeni yesigaba segesi, kanti isilinganiso se-molar se-silicon ne-carbon engxenyeni yesigaba segesi sihlobene nosayizi wezinhlayiya zempuphu ye-silicon carbide. Ingcindezi iyonke kanye nesilinganiso se-silicon-carbon sohlelo lokukhula kuyanda ngokuncipha kosayizi wezinhlayiya. Lapho usayizi wezinhlayiya wehla kusuka ku-2-3 mm kuya ku-0.06 mm, isilinganiso se-silicon-carbon sikhuphuka kusuka ku-1.3 kuya ku-4.0. Lapho izinhlayiya zincane ngezinga elithile, ingcindezi engaphelele ye-Si iyanda, futhi ungqimba lwefilimu ye-Si lwenziwa phezu kwekristalu ekhulayo, okubangela ukukhula kwegesi-uketshezi-okuqinile, okuthinta i-polymorphism, amaphutha amaphuzu kanye namaphutha omugqa kukristalu. Ngakho-ke, usayizi wezinhlayiya wempuphu ye-silicon carbide ehlanzekile kakhulu kumele ulawulwe kahle.
Ngaphezu kwalokho, uma usayizi wezinhlayiya zempuphu ye-SiC uncane kakhulu, impuphu ibola ngokushesha, okuholela ekukhuleni ngokweqile kwamakristalu angawodwa e-SiC. Ngakolunye uhlangothi, endaweni yokushisa ephezulu yokukhula kwekristalu engawodwa ye-SiC, izinqubo ezimbili zokwenziwa nokubola zenziwa ngasikhathi sinye. Impuphu ye-silicon carbide izobola futhi yakhe ikhabhoni esigabeni segesi kanye nesigaba esiqinile njenge-Si, i-Si2C, i-SiC2, okuholela ekufakweni kwe-polycrystalline powder okukhulu kanye nokwakheka kokufakwa kwekhabhoni kukristalu; ngakolunye uhlangothi, lapho izinga lokubola kwempuphu lishesha kakhulu, isakhiwo sekristalu sekristalu engawodwa ye-SiC ekhulile sithambekele ekushintsheni, okwenza kube nzima ukulawula ikhwalithi yekristalu engawodwa ye-SiC ekhulile.
1.2 Umphumela wesimo sekristalu eliyimpuphu ekukhuleni kwekristalu
Ukukhula kwekristalu eyodwa ye-SiC ngendlela ye-PVT kuyinqubo ye-sublimation-recrystallization ekushiseni okuphezulu. Uhlobo lwekristalu lwezinto zokusetshenziswa ze-SiC lunethonya elibalulekile ekukhuleni kwekristalu. Enkambisweni yokwenziwa kwempuphu, isigaba sokwenziwa kwesimo sokushisa okuphansi (β-SiC) esinesakhiwo se-cubic seseli leyunithi kanye nesigaba sokwenziwa kwesimo sokushisa okuphezulu (α-SiC) esinesakhiwo se-hexagonal seseli leyunithi sizokhiqizwa kakhulu. Kunezinhlobo eziningi zekristalu ye-silicon carbide kanye nobubanzi obuncane bokulawula izinga lokushisa. Isibonelo, i-3C-SiC izoguquka ibe yi-hexagonal silicon carbide polymorph, okungukuthi i-4H/6H-SiC, emazingeni okushisa angaphezu kuka-1900°C.
Ngesikhathi senqubo yokukhula kwekristalu elilodwa, lapho kusetshenziswa i-β-SiC powder ukukhulisa amakristalu, isilinganiso se-silicon-carbon molar sikhulu kuno-5.5, kuyilapho lapho kusetshenziswa i-α-SiC powder ukukhulisa amakristalu, isilinganiso se-silicon-carbon molar singu-1.2. Lapho izinga lokushisa likhuphuka, kwenzeka ushintsho lwesigaba endaweni yokucwilisa. Ngalesi sikhathi, isilinganiso se-molar esigabeni segesi siba sikhulu, okungavumeli ukukhula kwekristalu. Ngaphezu kwalokho, okunye ukungcola kwesigaba segesi, okuhlanganisa i-carbon, i-silicon, ne-silicon dioxide, kukhiqizwa kalula ngesikhathi senqubo yokuguquka kwesigaba. Ukuba khona kwalokhu kungcola kubangela ukuthi ikristalu ikhiqize ama-microtubes nama-voids. Ngakho-ke, ifomu lekristalu le-powder kumele lilawulwe ngokunembile.
1.3 Umphumela wokungcola kwempuphu ekukhuleni kwekristalu
Okuqukethwe kokungcola ku-SiC powder kuthinta i-nucleation ezenzakalelayo ngesikhathi sokukhula kwekristalu. Uma okuqukethwe kokungcola kuphakeme, kulapho kungenzeka khona ukuthi ikristalu i-nucleate ezenzakalelayo. Ku-SiC, ukungcola okuyinhloko kwensimbi kufaka phakathi i-B, i-Al, i-V, ne-Ni, okungase kungeniswe ngamathuluzi okucubungula ngesikhathi sokucubungula i-silicon powder kanye ne-carbon powder. Phakathi kwazo, i-B ne-Al yizona zingcola eziyinhloko zokwamukela izinga lamandla angajulile ku-SiC, okuholela ekunciphiseni kokumelana kwe-SiC. Okunye ukungcola kwensimbi kuzoletha amazinga amaningi wamandla, okuholela ezimpahleni zikagesi ezingazinzile zamakristalu angashadile e-SiC emazingeni okushisa aphezulu, futhi kube nomthelela omkhulu ezimpahleni zikagesi zama-substrate e-semi-insulating single crystal ahlanzekile kakhulu, ikakhulukazi ukumelana. Ngakho-ke, i-high-purity silicon carbide powder kumele yenziwe ngangokunokwenzeka.
1.4 Umphumela wokuqukethwe kwe-nitrogen ku-powder ekukhuleni kwekristalu
Izinga lokuqukethwe kwe-nitrogen linquma ukumelana kwe-substrate eyodwa yekristalu. Abakhiqizi abakhulu badinga ukulungisa ukuhlushwa kwe-nitrogen doping ezintweni zokwenziwa ngokwenqubo yokukhula kwekristalu evuthiwe ngesikhathi sokwenziwa kwe-powder. Ama-substrate e-silicon carbide single crystal ahlanzekile kakhulu ayizinto ezithembisa kakhulu zezingxenye ze-elekthronikhi zezempi. Ukuze kukhuliswe ama-substrate e-crystal eyodwa ahlanzekile kakhulu anokumelana okuphezulu kanye nezakhiwo zikagesi ezinhle kakhulu, okuqukethwe kwe-nitrogen engcolile eyinhloko ku-substrate kumele kulawulwe ezingeni eliphansi. Ama-substrate e-crystal eyodwa aqhubayo adinga okuqukethwe kwe-nitrogen ukuze kulawulwe ngokuhlushwa okuphezulu.
2 Ubuchwepheshe bokulawula obuyinhloko bokwenziwa kwempuphu
Ngenxa yezindawo ezahlukene zokusetshenziswa kwezingxenye ze-silicon carbide, ubuchwepheshe bokwenziwa kwama-powder okukhula bunezinqubo ezahlukene. Kuma-powder okukhula kwe-single crystal oqhutshwa uhlobo lwe-N, kudingeka ubumsulwa obukhulu kanye ne-single phase; kuyilapho kuma-powder okukhula kwe-single crystal okufakwayo kancane, kudingeka ukulawulwa okuqinile kokuqukethwe kwe-nitrogen.
2.1 Ukulawula usayizi wezinhlayiya zempuphu
2.1.1 Izinga lokushisa lokwenziwa
Uma kugcinwa ezinye izimo zenqubo zingashintshi, izimpushana ze-SiC ezikhiqizwe emazingeni okushisa okwenziwa okungu-1900 ℃, 2000 ℃, 2100 ℃, kanye no-2200 ℃ zathathwa amasampula futhi zahlaziywa. Njengoba kuboniswe kuMfanekiso 1, kungabonakala ukuthi usayizi wezinhlayiya ungu-250~600 μm ku-1900 ℃, futhi usayizi wezinhlayiya uyanda ube ngu-600~850 μm ku-2000 ℃, futhi usayizi wezinhlayiya ushintsha kakhulu. Lapho izinga lokushisa liqhubeka likhuphuka lifike ku-2100 ℃, usayizi wezinhlayiya zempushana ye-SiC ungu-850~2360 μm, futhi ukwanda kuvame ukuba mnene. Usayizi wezinhlayiya ze-SiC ku-2200 ℃ uzinzile cishe ku-2360 μm. Ukwanda kwezinga lokushisa lokwenziwa kusukela ku-1900 ℃ kunomthelela omuhle kusayizi wezinhlayiya ze-SiC. Lapho izinga lokushisa lokwenziwa liqhubeka likhuphuka lisuka ku-2100 ℃, usayizi wezinhlayiya awusashintshi kakhulu. Ngakho-ke, lapho izinga lokushisa lokwenziwa lisethwe ku-2100 ℃, usayizi omkhulu wezinhlayiya ungakhiwa ngokusetshenziswa kwamandla okuphansi.
2.1.2 Isikhathi sokwenziwa
Ezinye izimo zenqubo azishintshi, kanti isikhathi sokwenziwa sibekwe kumahora ama-4, amahora ama-8, kanye namahora ayi-12 ngokulandelana. Ukuhlaziywa kwesampula yempuphu ye-SiC ekhiqizwe kukhonjisiwe kuMfanekiso 2. Kutholakale ukuthi isikhathi sokwenziwa sinomthelela omkhulu kusayizi wezinhlayiya ze-SiC. Uma isikhathi sokwenziwa singamahora ama-4, usayizi wezinhlayiya usatshalaliswa kakhulu kuma-200 μm; uma isikhathi sokwenziwa singamahora ayi-8, usayizi wezinhlayiya zokwenziwa uyanda kakhulu, usatshalaliswa kakhulu cishe kuma-1 000 μm; njengoba isikhathi sokwenziwa siqhubeka nokwanda, usayizi wezinhlayiya uyanda kakhulu, usatshalaliswa kakhulu cishe kuma-2 000 μm.
2.1.3 Ithonya lobukhulu bezinhlayiya zezinto zokusetshenziswa
Njengoba uchungechunge lokukhiqizwa kwezinto ze-silicon zasekhaya luthuthuka kancane kancane, ubumsulwa bezinto ze-silicon buyathuthuka kakhulu. Njengamanje, izinto ze-silicon ezisetshenziswa ekuhlanganiseni zihlukaniswe kakhulu nge-silicon e-granular kanye ne-silicon ephuthiwe, njengoba kuboniswe kuMfanekiso 3.
Izinto zokusetshenziswa ze-silicon ezahlukene zasetshenziswa ukwenza izivivinyo zokwenziwa kwe-silicon carbide. Ukuqhathaniswa kwemikhiqizo yokwenziwa kuboniswe kuMfanekiso 4. Ukuhlaziywa kukhombisa ukuthi uma kusetshenziswa izinto zokusetshenziswa ze-silicon block, inani elikhulu lezinto ze-Si likhona kumkhiqizo. Ngemva kokuba i-silicon block ichotshoziwe okwesibili, i-Si element kumkhiqizo wokwenziwa incishiswa kakhulu, kodwa isekhona. Ekugcineni, i-silicon powder isetshenziselwa ukwenziwa, futhi i-SiC kuphela ekhona kumkhiqizo. Lokhu kungenxa yokuthi enkambisweni yokukhiqiza, i-silicon enkulu e-granular idinga ukubhekana nokusabela kokwenziwa kwendawo kuqala, bese i-silicon carbide ikhiqizwa ebusweni, okuvimbela i-Si powder yangaphakathi ukuthi ingahlangani ne-C powder. Ngakho-ke, uma i-block silicon isetshenziswa njengezinto zokusetshenziswa, idinga ukuchotshozwa bese ifakwa enkambisweni yesibili yokwenziwa ukuze kutholakale i-silicon carbide powder yokukhula kwekristalu.
2.2 Ukulawulwa kwefomu lekristalu yempuphu
2.2.1 Ithonya lokushisa lokwenziwa
Uma kugcinwa ezinye izimo zenqubo zingashintshi, izinga lokushisa lokwenziwa lingu-1500℃, 1700℃, 1900℃, kanye no-2100℃, kanti i-SiC powder ekhiqiziwe iyathathwa futhi ihlaziywe. Njengoba kuboniswe kuMfanekiso 5, i-β-SiC iphuzi njengomhlaba, kanti i-α-SiC inombala okhanyayo. Ngokubheka umbala kanye nesimo se-powder ekhiqiziwe, kungatholakala ukuthi umkhiqizo okhiqiziwe uyi-β-SiC emazingeni okushisa angu-1500℃ no-1700℃. Ku-1900℃, umbala uba lula, futhi kuvela izinhlayiya ezinezinhlangothi eziyisithupha, okubonisa ukuthi ngemva kokuba izinga lokushisa likhuphukele ku-1900℃, kwenzeka ushintsho lwesigaba, futhi ingxenye ye-β-SiC iguqulwa ibe yi-α-SiC; lapho izinga lokushisa liqhubeka likhuphukela ku-2100℃, kutholakala ukuthi izinhlayiya ezikhiqiziwe zicacile, kanti i-α-SiC isiguquliwe ngokuyisisekelo.
2.2.2 Umphumela wesikhathi sokwenziwa
Ezinye izimo zenqubo azishintshi, futhi isikhathi sokwenziwa sisethwe kumahora angu-4, amahora angu-8, kanye namahora angu-12, ngokulandelana. Impuphu ye-SiC ekhiqiziwe ithathwa isampula futhi ihlaziywe yi-diffractometer (XRD). Imiphumela iboniswe kuMfanekiso 6. Isikhathi sokwenziwa sinethonya elithile kumkhiqizo owenziwe yimpuphu ye-SiC. Uma isikhathi sokwenziwa singamahora angu-4 namahora angu-8, umkhiqizo wokwenziwa ikakhulukazi u-6H-SiC; uma isikhathi sokwenziwa singamahora angu-12, kuvela i-15R-SiC kumkhiqizo.
2.2.3 Ithonya lesilinganiso sezinto zokusetshenziswa
Ezinye izinqubo azishintshi, inani lezinto ze-silicon-carbon liyahlaziywa, kanti izilinganiso ziyi-1.00, 1.05, 1.10 kanye no-1.15 ngokulandelana kokuhlolwa kokwenziwa. Imiphumela iboniswe kuMfanekiso 7.
Kusukela ku-XRD spectrum, kungabonakala ukuthi lapho isilinganiso se-silicon-carbon singaphezu kuka-1.05, kuvela i-Si eyengeziwe kumkhiqizo, futhi lapho isilinganiso se-silicon-carbon singaphansi kuka-1.05, kuvela i-C eyengeziwe. Lapho isilinganiso se-silicon-carbon singu-1.05, i-carbon yamahhala kumkhiqizo wokwenziwa iyasuswa ngokuyisisekelo, futhi akukho silicon yamahhala evelayo. Ngakho-ke, isilinganiso senani lesilinganiso se-silicon-carbon kufanele sibe ngu-1.05 ukuze kuhlanganiswe i-SiC ehlanzekile kakhulu.
2.3 Ukulawulwa kokuqukethwe kwe-nitrogen ephansi ku-powder
2.3.1 Izinto zokusetshenziswa zokwenziwa
Izinto zokusetshenziswa ezisetshenziswe kulolu vivinyo yi-carbon powder ehlanzekile kakhulu kanye ne-silicon powder ehlanzekile kakhulu enobubanzi obuphakathi obungu-20 μm. Ngenxa yobukhulu bazo obuncane bezinhlayiya kanye nendawo enkulu yobuso, kulula ukumunca i-N2 emoyeni. Lapho kuhlanganiswa i-powder, izolethwa ibe yi-crystal form ye-powder. Ukuze kukhule amakristalu ohlobo lwe-N, ukungalingani kwe-N2 ku-powder kuholela ekumelaneni okungalingani kwe-crystal ngisho nokushintsha kwesimo se-crystal. Okuqukethwe kwe-nitrogen ye-powder eyenziwe ngemva kokungeniswa kwe-hydrogen kuphansi kakhulu. Lokhu kungenxa yokuthi ivolumu yama-molecule e-hydrogen incane. Lapho i-N2 imuncwa ku-carbon powder kanye ne-silicon powder ishiswa futhi ibola ebusweni, i-H2 isakazeka ngokuphelele esikhaleni esiphakathi kwama-powders ngevolumu yayo encane, ithathe indawo ye-N2, futhi i-N2 iphuma esitsheni ngesikhathi senqubo yokuhlanza, ifeze injongo yokususa okuqukethwe kwe-nitrogen.
2.3.2 Inqubo yokwenziwa
Ngesikhathi sokwenziwa kwempuphu ye-silicon carbide, njengoba irediyasi yama-athomu e-carbon nama-athomu e-nitrogen ifana, i-nitrogen izothatha indawo yezikhala ze-carbon ku-silicon carbide, ngaleyo ndlela ikhulise okuqukethwe kwe-nitrogen. Le nqubo yokuhlola isebenzisa indlela yokwethula i-H2, kanti i-H2 isabela nezakhi ze-carbon ne-silicon ku-synthesis crucible ukuze ikhiqize amagesi e-C2H2, C2H, kanye ne-SiH. Okuqukethwe kwezakhi ze-carbon kuyanda ngokudluliswa kwesigaba segesi, ngaleyo ndlela kuncishiswe izikhala ze-carbon. Inhloso yokususa i-nitrogen iyafezwa.
2.3.3 Ukulawulwa kokuqukethwe kwe-nitrogen yangemuva kwenqubo
Izitsha ze-graphite ezine-porosity enkulu zingasetshenziswa njengemithombo eyengeziwe ye-C ukuze zimunce umphunga we-Si ezingxenyeni zesigaba segesi, zinciphise i-Si ezingxenyeni zesigaba segesi, ngaleyo ndlela zandise i-C/Si. Ngesikhathi esifanayo, izitsha ze-graphite nazo zingasabela nomoya we-Si ukuze zikhiqize i-Si2C, i-SiC2 kanye ne-SiC, okulingana nomoya we-Si oletha umthombo we-C kusuka ku-graphite crucible emoyeni wokukhula, kwandiswe isilinganiso se-C, futhi kwandiswe isilinganiso se-carbon-silicon. Ngakho-ke, isilinganiso se-carbon-silicon singandiswa ngokusebenzisa izitsha ze-graphite ezine-porosity enkulu, kuncishiswe izikhala ze-carbon, futhi kufezwe injongo yokususa i-nitrogen.
3 Ukuhlaziywa kanye nokwakhiwa kwenqubo yokwenziwa kwe-single crystal powder
3.1 Isimiso kanye nomklamo wenqubo yokuhlanganisa
Ngocwaningo oluphelele olushiwo ngenhla mayelana nokulawulwa kosayizi wezinhlayiya, isimo sekristalu kanye nokuqukethwe kwe-nitrogen kokwenziwa kwempuphu, kuphakanyiswa inqubo yokwenziwa. Impuphu ye-C ehlanzekile kakhulu kanye nempuphu ye-Si kuyakhethwa, futhi kuxutshwa ngokulinganayo futhi kulayishwe ku-graphite crucible ngokwesilinganiso se-silicon-carbon esingu-1.05. Izinyathelo zenqubo zihlukaniswe kakhulu ngezigaba ezine:
1) Inqubo yokususa i-nitrogen ekushiseni okuphansi, i-vacuum cleaner ibe yi-5×10-4 Pa, bese ingenisa i-hydrogen, okwenza ingcindezi yegumbi ibe cishe yi-80 kPa, igcinwe imizuzu eyi-15, bese iphinda izikhathi ezine. Le nqubo ingasusa izakhi ze-nitrogen ebusweni be-carbon powder kanye ne-silicon powder.
2) Inqubo yokususa i-nitrogen ekushiseni okuphezulu, ukuhlanza ku-5×10-4 Pa, bese kushiswa ku-950 ℃, bese kufakwa i-hydrogen, okwenza ingcindezi yegumbi ibe cishe yi-80 kPa, igcinwe imizuzu eyi-15, bese iphinda izikhathi ezine. Le nqubo ingasusa izakhi ze-nitrogen ebusweni be-carbon powder kanye ne-silicon powder, futhi iqhube i-nitrogen ensimini yokushisa.
3) Ukwenziwa kwenqubo yesigaba sokushisa okuphansi, susa ku-5×10-4 Pa, bese ushisa ku-1350℃, gcina amahora ayi-12, bese ufaka i-hydrogen ukuze wenze ingcindezi yegumbi ibe cishe yi-80 kPa, gcina ihora eli-1. Le nqubo ingasusa i-nitrogen eguquguqukayo ngesikhathi senqubo yokwenziwa.
4) Ukuhlanganiswa kwenqubo yesigaba sokushisa okuphezulu, gcwalisa ngesilinganiso esithile sokugeleza kwevolumu yegesi ye-hydrogen ehlanzekile kakhulu ne-argon mixed gas, yenza ingcindezi yegumbi ibe ngu-80 kPa, iphakamise izinga lokushisa libe ngu-2100℃, igcine amahora ayi-10. Le nqubo iqedela ukuguqulwa kwempuphu ye-silicon carbide kusuka ku-β-SiC ibe yi-α-SiC futhi iqedela ukukhula kwezinhlayiya zekristalu.
Ekugcineni, linda izinga lokushisa legumbi liphole lifinyelele izinga lokushisa legumbi, gcwalisa umfutho womoya, bese ukhipha impuphu.
3.2 Inqubo yokucubungula ufulawa ngemuva kokucubungula
Ngemva kokuba i-powder yenziwe ngenqubo engenhla, kumele icutshungulwe ngemuva kokususa i-carbon yamahhala, i-silicon kanye nokunye ukungcola kwensimbi bese ihlola usayizi wezinhlayiya. Okokuqala, i-powder eyenziwe ifakwa emshinini wokugaya ibhola ukuze ichotshozwe, bese i-silicon carbide powder echotshoziwe ifakwa esithandweni somlilo bese ishiswa ku-450°C yi-oxygen. I-carbon yamahhala e-powder i-oxidized ngokushisa ukuze ikhiqize igesi ye-carbon dioxide ephuma ekamelweni, ngaleyo ndlela kufezwe ukususwa kwe-carbon yamahhala. Ngemva kwalokho, kulungiswa uketshezi lokuhlanza olune-acidic bese lufakwa emshinini wokuhlanza izinhlayiya ze-silicon carbide ukuze kuhlanzwe ukuze kususwe i-carbon, i-silicon kanye nokungcola kwensimbi okusele okudalwe ngesikhathi senqubo yokwenza. Ngemva kwalokho, i-acid esele igezwa ngamanzi ahlanzekile bese yomiswa. I-powder eyomile ivinjelwa esikrinini esidlidlizayo ukuze kukhethwe usayizi wezinhlayiya ukuze kukhule ikristalu.
Isikhathi sokuthunyelwe: Agasti-08-2024