Ukadaulo wa mafilimu opyapyala a diamondi - mutu 1

Ulusi wotentha wa CVD ndiye njira yoyambirira komanso yotchuka kwambiri yokulira diamondi pa mphamvu yotsika. 1982 Matsumoto ndi anzake anatentha ulusi wachitsulo wosasunthika kufika pa 2000°C, pomwe kutentha komwe mpweya wa H2 umadutsa mu ulusiwo kumapanga maatomu a hydrogen mosavuta. Kupanga kwa atomu ya hydrogen panthawi ya hydrocarbon pyrolysis kunawonjezera kuchuluka kwa mafilimu a diamondi. Daimondi imasungidwa mosankha ndipo mapangidwe a graphite amalepheretsedwa, zomwe zimapangitsa kuti mafilimu a diamondi azisungidwa pamlingo wa mm/h, womwe ndi kuchuluka kwakukulu kwa njira zomwe zimagwiritsidwa ntchito kwambiri m'mafakitale. HFCVD ikhoza kuchitika pogwiritsa ntchito magwero osiyanasiyana a kaboni, monga methane, propane, acetylene, ndi ma hydrocarbon ena, komanso ma hydrocarbon ena okhala ndi mpweya, monga acetone, ethanol, ndi methanol. Kuwonjezera magulu okhala ndi mpweya kumapangitsa kuti kutentha kwa diamondi kukhale koyenera.

Kuwonjezera pa dongosolo la HFCVD lachizolowezi, pali kusintha kwina ku dongosolo la HFCVD. Lodziwika kwambiri ndi dongosolo la DC plasma ndi HFCVD. Mu dongosololi, mphamvu ya bias ingagwiritsidwe ntchito ku substrate ndi filament. Kukhazikika kwabwino pa substrate ndi bias inayake yoipa pa filament kumapangitsa ma elekitironi kuphulitsa substrate, zomwe zimapangitsa kuti hydrogen pamwamba pake ichotsedwe. Zotsatira za desorption ndi kuwonjezeka kwa kuchuluka kwa deposition ya filimu ya diamondi (pafupifupi 10 mm/h), njira yotchedwa electron-assisted HFCVD. pamene mphamvu ya bias ili yokwanira kupanga plasma yokhazikika, kuwonongeka kwa H2 ndi hydrocarbons kumawonjezeka kwambiri, zomwe pamapeto pake zimapangitsa kuti pakhale kuwonjezeka kwa kukula. Pamene polarity ya bias yasinthidwa (substrate ndi negatively being), ion bombardment imachitika pa substrate, zomwe zimapangitsa kuti diamondi nucleation iwonjezereke pa substrate zomwe si diamondi. Kusintha kwina ndikusintha ulusi umodzi wotentha ndi ulusi wosiyanasiyana kuti pakhale malo ofanana komanso kuti pakhale filimu ya diamondi yambiri. Vuto la HFCVD ndilakuti kutentha kwa ulusi kumatha kupanga zinthu zodetsa mu filimu ya diamondi.

(2) Microwave Plasma CVD (MWCVD)

M'zaka za m'ma 1970, asayansi adapeza kuti kuchuluka kwa atomu ya hydrogen kumatha kuwonjezeka pogwiritsa ntchito plasma ya DC. Zotsatira zake, plasma inakhala njira ina yolimbikitsira kupanga mafilimu a diamondi mwa kuwononga H2 kukhala atomu ya hydrogen ndikuyambitsa magulu a atomu okhala ndi kaboni. Kuphatikiza pa plasma ya DC, mitundu ina iwiri ya plasma yalandiridwanso chidwi. Microwave plasma CVD ili ndi pafupipafupi yoyambitsa 2.45 GHZ, ndipo RF plasma CVD ili ndi pafupipafupi yoyambitsa 13.56 MHz. Ma microwave plasma ndi apadera chifukwa pafupipafupi ya microwave imayambitsa kugwedezeka kwa ma elekitironi. Ma elekitironi akagundana ndi ma atomu a gasi kapena mamolekyulu, kuchuluka kwa kugawanika kumapangidwa. Microwave plasma nthawi zambiri imatchedwa chinthu chokhala ndi ma elekitironi "otentha", ma ayoni "ozizira" ndi tinthu tating'onoting'ono. Pakuyika filimu yopyapyala, ma microwave amalowa mchipinda chopangira CVD cholimbikitsidwa ndi plasma kudzera pawindo. Plasma yowala nthawi zambiri imakhala yozungulira, ndipo kukula kwa bwalo kumawonjezeka ndi mphamvu ya microwave. Mafilimu opyapyala a diamondi amamera pa nthaka yomwe ili pakona pa malo owala, ndipo nthaka siyenera kukhudzana mwachindunji ndi malo owala.

– Nkhaniyi yatulutsidwa ndiwopanga makina ophikira vacuumGuangdong Zhenhua