| Diamond film has many excellent properties, such as the rigidity and modulus of elasticity like crude diamond, high thermal conductivity, outstanding optical properties, great chemistry stability, very wide band gap, high refractive index and very low dielectric constant. Diamond film has been applied in the field of electron, optics, acoustics, exactitude mechanism and semiconductor. Diamond film is a new function material which has a wide range of applications future. It attracts much attention in the field of materials.Diamond film is synthesized by direct current plasma assisted hot filament chemical vapor deposition. The mechanism of nucleation and growth of the diamond film is studied. The heat-conducting model of diamond film is introduced and roughly established.In order to improve the quality of diamond film, a mirror-polished single-crystal Si surface is treated with the process of ultrasonic management, lapping finish and seeding. The function of surface pretreatment is interpreted. The influence of the surface pretreatment, the gas flow ratio, the substrate temperature, the total gas pressure and the distance between hot filament and substrate on the diamond film quality and growth rate is mainly illustrated. The behavior of dynamics growth of diamond film is studied in detail. The optimum process parameters of the diamond growth on the Si surface are studied which can be gropingly summarized as follows: The DC voltage is 100V, the methane concentration is 2%, the heat filament temperature is 2030℃, the substrate temperature is 850℃, the total gas pressure is 5.0×l0~3Pa.Firstly the heat-conducting model of diamond film has been discussed, then it is simply represented with one dimensional stable heat transfer and is carried out numerical analysis. Secondly the mathematical model is roughly built up and the computer simulation codes are programmed. Based on these, the relating factors that influence the thermal conductivity are analyzed. |
PDF Full Text Request