Cov xov kub CVD yog txoj kev cog pob zeb diamond thaum ntxov tshaj plaws thiab nrov tshaj plaws ntawm kev kub siab. Xyoo 1982 Matsumoto et al. tau ua kom cov xov hlau refractory sov txog li 2000 ° C, uas qhov kub thiab txias uas cov roj H2 hla dhau cov xov hlau yooj yim tsim cov hydrogen atoms. Kev tsim cov atomic hydrogen thaum lub sijhawm hydrocarbon pyrolysis ua rau cov yeeb yaj kiab pob zeb diamond nce ntxiv. Pob zeb diamond raug xaiv thiab tsim graphite raug txwv, ua rau cov yeeb yaj kiab pob zeb diamond nce ntxiv ntawm mm / h, uas yog qhov siab heev rau cov txheej txheem uas siv hauv kev lag luam. HFCVD tuaj yeem ua tiav los ntawm ntau yam carbon, xws li methane, propane, acetylene, thiab lwm yam hydrocarbons, thiab txawm tias qee cov hydrocarbons uas muaj oxygen, xws li acetone, ethanol, thiab methanol. Kev ntxiv cov pab pawg uas muaj oxygen ua rau qhov kub thiab txias rau kev tso pob zeb diamond dav dua.
Ntxiv rau qhov system HFCVD ib txwm muaj, muaj ntau qhov kev hloov kho rau HFCVD system. Qhov feem ntau yog kev sib xyaw ua ke ntawm DC plasma thiab HFCVD system. Hauv lub system no, lub zog hluav taws xob bias tuaj yeem siv rau lub substrate thiab filament. Kev cuam tshuam zoo tas li ntawm lub substrate thiab qee qhov kev cuam tshuam tsis zoo ntawm lub filament ua rau cov electrons bombard lub substrate, ua rau cov hydrogen ntawm qhov chaw desorb. Qhov tshwm sim ntawm kev desorption yog kev nce ntxiv ntawm tus nqi deposition ntawm cov zaj duab xis pob zeb diamond (kwv yees li 10 mm/h), ib txoj kev paub hu ua electron-assisted HFCVD. thaum lub zog hluav taws xob bias siab txaus los tsim kom muaj kev tso tawm plasma ruaj khov, kev rhuav tshem ntawm H2 thiab hydrocarbons nce ntxiv, uas thaum kawg ua rau muaj kev nce ntxiv ntawm tus nqi loj hlob. Thaum lub polarity ntawm bias raug thim rov qab (substrate yog negatively biased), ion bombardment tshwm sim ntawm lub substrate, ua rau muaj kev nce ntxiv ntawm pob zeb diamond nucleation ntawm cov substrates uas tsis yog pob zeb diamond. Lwm qhov kev hloov kho yog hloov ib txoj hlua kub nrog ntau txoj hlua sib txawv kom ua tiav qhov kev tso dej sib npaug thiab thaum kawg yog thaj chaw loj ntawm cov yeeb yaj kiab pob zeb diamond. Qhov tsis zoo ntawm HFCVD yog tias qhov cua sov ntawm cov filament tuaj yeem tsim cov pa phem hauv cov yeeb yaj kiab pob zeb diamond.
(2) Microwave Plasma CVD (MWCVD)
Xyoo 1970, cov kws tshawb fawb tau pom tias qhov concentration ntawm atomic hydrogen tuaj yeem nce ntxiv siv DC plasma. Yog li ntawd, plasma tau dhau los ua lwm txoj hauv kev los txhawb kev tsim cov yeeb yaj kiab pob zeb diamond los ntawm kev rhuav tshem H2 rau hauv atomic hydrogen thiab ua kom cov pa roj carbon ua haujlwm. Ntxiv rau DC plasma, ob hom plasma lwm yam kuj tau txais kev saib xyuas. Lub microwave plasma CVD muaj qhov zaus excitation ntawm 2.45 GHZ, thiab RF plasma CVD muaj qhov zaus excitation ntawm 13.56 MHz. microwave plasmas yog qhov tshwj xeeb hauv qhov microwave zaus ua rau electron vibrations. Thaum electrons sib tsoo nrog cov roj atoms lossis molecules, tus nqi dissociation siab yog tsim tawm. Microwave plasma feem ntau hu ua teeb meem nrog "kub" electrons, "txias" ions thiab cov khoom me me. Thaum lub sijhawm tso zaj duab xis nyias, microwaves nkag mus rau hauv plasma-enhanced CVD synthesis chamber los ntawm lub qhov rais. Lub luminescent plasma feem ntau yog spherical hauv cov duab, thiab qhov loj ntawm lub sphere nce nrog lub zog microwave. Cov yeeb yaj kiab nyias nyias ntawm pob zeb diamond raug loj hlob ntawm ib lub substrate hauv ib lub ces kaum ntawm thaj chaw luminescent, thiab lub substrate tsis tas yuav tsum sib cuag ncaj qha nrog thaj chaw luminescent.
– Tsab xov xwm no yog tso tawm los ntawmlub tshuab nqus tsev txheej tshuab chaw tsim khoomGuangdong Zhenhua
Lub sijhawm tshaj tawm: Lub Rau Hli-19-2024