Txoj kev PVT, uas nws lub npe tag nrho yog Physical Vapor Transportation, yog ib txoj kev siv ntau rau kev loj hlob silicon carbide (SiC) cov siv lead ua nyob rau hauv qhov kub thiab txias siab. Nws lub hauv paus ntsiab lus yog kom sov silicon carbide hmoov rau sublimation ntawm qhov kub siab tshaj 2300 ℃ thiab nyob rau hauv ib puag ncig qis-siab ze rau lub tshuab nqus tsev, tsim cov roj tshuaj tiv thaiv uas muaj cov khoom siv roj xws li Si, Si2C, thiab SiC2. Vim yog qhov sib txawv ntawm cov roj-theem ib nrab ntawm cov khoom Si thiab C tsim los ntawm cov khoom siv khoom-theem sublimation, Si/C stoichiometric piv sib txawv nrog rau qhov kev faib tawm thermal teb. Yog li ntawd, nws yog qhov tsim nyog los tswj kev faib tawm thiab kev thauj mus los ntawm cov khoom siv roj-theem kom ntseeg tau tias lawv mus txog qhov chaw crystallization tshwj xeeb hauv chav loj hlob.
Txhawm rau tiv thaiv kev tsim cov roj-theem crystallization tsis zoo los ntawm kev tsim cov polycrystalline silicon carbide, cov silicon carbide noob crystals raug teeb tsa rau saum toj ntawm lub chamber loj hlob. Nyob rau hauv kev tsav tsheb ntawm cov roj-theem supersaturation, cov khoom roj-theem yuav tso rau ntawm qhov chaw ntawm cov noob crystal los tsim cov silicon carbide ib leeg crystals. Tag nrho cov txheej txheem tshuaj tiv thaiv tshwm sim hauv lub chamber loj hlob kaw, qhov twg txhua qhov kev ntsuas ntawm lub kaw lus tshuaj tiv thaiv tau txuas nrog ib leeg. Txhua qhov kev hloov pauv hauv cov xwm txheej loj hlob yuav cuam tshuam rau kev ruaj khov ntawm kev loj hlob ntawm ib leeg crystal.
Tsis tas li ntawd xwb, cov qauv sib txawv ntawm cov pob zeb silicon carbide ib leeg siv lead ua rau muaj ntau yam kev sib txuas atomic thiab txoj kev sib txuas, yog li tsim ntau dua 200 daim ntawv siv lead ua ntawm silicon carbide isomers. Qhov kev hloov pauv hluav taws xob ntawm cov ntawv siv lead ua sib txawv yog qhov tsawg heev, yog li kev hloov pauv daim ntawv siv lead ua yuav tshwm sim hauv PVT ib leeg siv lead ua loj hlob, ua rau cov ntawv siv lead ua tsis sib haum xeeb thiab ntau yam kev puas tsuaj ntawm cov khoom siv lead ua. Yog li ntawd, nws yog qhov tsim nyog siv cov khoom siv tshuaj xyuas tshwj xeeb los ntes cov ntawv siv lead ua thiab ntau yam kev puas tsuaj ntawm cov khoom siv lead ua.
Cov txheej txheem npaj ntawm silicon carbide muaj cov kev xav tau siab heev, feem ntau yog pom tseeb hauv cov hauv qab no:
- Muaj ntau yam tsis huv hauv cov txheej txheem tsim cov hmoov silicon carbide, ua rau nws nyuaj rau kom tau txais cov hmoov ntshiab siab. Qhov tsis sib xyaw ua ke ntawm cov hmoov silicon thiab cov hmoov carbon ua qhov chaw ua rau muaj kev tsis sib npaug ntawm Si / C. Cov duab siv lead ua thiab qhov loj me ntawm cov hmoov silicon carbide tom qab tsim cov hmoov silicon carbide nyuaj rau tswj.
- Nyob rau hauv qhov kub siab tshaj 2300 ℃ thiab ze ntawm lub tshuab nqus tsev, silicon carbide dhau los ntawm "khoom siv khov-roj-khoom siv" kev hloov pauv thiab recrystallization hauv lub chamber graphite kaw. Cov txheej txheem no muaj lub voj voog loj hlob ntev, nyuaj rau tswj, thiab muaj qhov tsis zoo xws li microtubules thiab inclusions.
- Silicon carbide muaj ntau tshaj 200 hom siv lead ua sib txawv, tab sis feem ntau tsuas yog xav tau ib hom siv lead ua xwb. Thaum lub sijhawm loj hlob, kev hloov pauv hom siv lead ua feem ntau tshwm sim, ua rau muaj ntau hom kev tsis sib xws. Thaum lub sijhawm npaj, nws nyuaj rau tswj hwm ib hom siv lead ua tshwj xeeb, thiab qhov kev hloov pauv zog ntawm cov hom siv lead ua sib txawv yog qis heev, uas ua rau muaj kev nyuaj ntawm kev tswj hwm. Kev tswj hwm parameter thiab kev tshawb fawb cuam tshuam thaum lub sijhawm no xav tau cov nqi R&D loj heev, uas kuj yog ib qho laj thawj rau tus nqi siab ntawm cov khoom siv silicon carbide.
Lub sijhawm tshaj tawm: Lub Xya Hli-03-2025