實驗將分成三部分，第一部份利用最容易成長鑽石的氫氣－甲烷環境，改變不同基板溫度與燈絲溫度，來尋找在這一套熱燈絲系統上的成長條件。第二部份為在不變動基板溫度、氣體流量氣壓等條件下逐步增加氬氣含量，成長鑽石薄膜並檢測其拉曼峰值與表面形貌。第三部份為先利用微波電漿源輔助解離氣體分子，在透過熱燈絲系統進行再次活化，在高氬氣環境下成長薄膜並與第二部份的結果進行比較。 Diamond films are high thermal conductivity and high tribological characteristics. They have great potential for industrial applications. The capability for growing diamond d films in large area is an important research issue. The granular structure of diamond films varied with the growth parameters. Among the microcrystalline diamond (MCD), nanocrystalline diamond (NCD) and ultrananocrystalline diamond (UNCD), the UNCD films possess characteristics of extreme smooth surface and superb electrical conductivity, which is very useful for device application.
Hot filament chemical vapor deposition HFCVD process is simple, low cast and has large area capability. However, this process cannot produce C2 species and therefore is difficult in growing diamond with nano-sized grains.
In this research, we re-design an HF-CVD system, explored the effect of growing parameters in microstructure development of diamond films. Moreover, we introduce C2 species, which were produced by MWCVD process into the HFCVD system so as to reduce the grain size of the diamond films. This research included 3 points: (I) We grow diamond films using CH4/H2 gas and optimize the growth parameter by systematic varying the substrate temperature and filament temperature. (II) With fixed substrate temperature, we add Ar gas into CH4/H2 Gas to systematically control the morphology of diamond films. (III) We introduce C2 species into HF-CVD system by exciting the CH4/Ar/H2 gas into plasma using microwave CVD process, so that granular structure of diamond films can be modified.
