| Summary: | 碩士 === 國立雲林科技大學 === 電子與資訊工程技術研究所 === 86 === Diamnond is well known as a valuable and potential material, which has a uniqe combination of extreme properties, such as high carrier mobility, high breakdown voltage, wide energy gap, and high carrier satruation veolcity. Especially the applications in optics and electronics, diamnond attracts a worldwide attention. Microwave plasma enhanced chemical vapor deposition (MPCVD) system at 2.45 GH z has been used to synthesize diamond films on 3-inches p-type (100) siliconwafers with a mixture of methane and diluted gydrogen. A range of prime growth parameters is utilized for exploring their relations to deposit structure , component, morphology, and other properties. The ranges of deposited parameters are listed: CH4/H2 = 0.5-1.5%, chamber pressure = 30-60 torr, microwave output power = 2-4 kW. The tendencies of films properties were characterized by utilizing Raman, SEM, XRD, AFM, and ESCA techniques. Then the quality of diamond films was resolved by chemical bonding, morphology, crystallinity, and composition.Through the experiments with a series of processing parameters, and by comparing the results of instrumental analyses, the properties and tendency of films were systematically arranged. The films are composed of diamond crystals and non-diamond carbon within grain boundary. Diamond doesn''t grow well at lower temperature, and is substituted by graphite at higher temperature. The nucleation rate does increase with higher carbon concentration, but excessive carbon lead to ball-like cluster or even graphit. By judging the sp3-bond, crystallinity, and stability at high temperature, we concluded a optimum condition: CH4/H2*= 1.0%, pressure = 45 torr and net microwave power = 2.00kW with substrate temperature range from 800 to 1000 C.The optimum parameters for synthesizing high-quality diamond films will be helpful for studying and designing optoelectronic devices of high-quality diamond films by using the MPCVD system.
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