Diamond Films Growth And Its Properties On Silicon Carbide Epitaxial

Growth of diamond films can be divided into two stages of nucleation and growth, the substrate temperature, deposition pressure, hydrocarbon gas flow rate and substrate bias and other parameters affect the diamond films nucleation stage, thus they have impacts on the diamond films surface structure and the orientation. So the process parameters becomes the important research object in diamond films synthesis.In this paper, diamond films were prepared successfully in silicon carbide substrate by the hot filament chemical vapor deposition. Studied the impact of various process parameters on the diamond films. discuss their function mechanism, optimize the process parameters, the conclusion is as follows:1.The pretreatment of the substrate can greatly improve the microstructure on the silicon carbide’s surface, thereby affect the diamond films’ continuity. Under the mechanical polishing and chemical cleaning method, diamond grains less, films’ continuity poor, and films falls off phenomenon; Under the ultrasonic cleaning pretreatment method, the diamond particle size is differ, films uniformity is poor; Under the grinding and ultrasonic cleaning method, diamond films density is high, the films continuity is best.2. The hydrogen flow rate has a close relationship to the diamond films surface structure and the orientation. When the hydrogen flow rate is 150 mL/min, hydrocarbon reactive group is not enough to result that diamond films are difficult to form. When the flow of hydrogen is 200 mL/min, the lower hydrogen flow rate is conducive to(111)-orientation growth. In addition, hydrogen on graphite etching is insufficient to result that diamond films are not pure. In the case of hydrogen flow rate of 250 mL/m in, hydrogen is sufficient to(100)-orientation growth.3. The substrate temperature and deposition pressure affect the diamond films nucleation rate. With the improvement of temperature or deposition pressure, the diamond films formation rate is the ascension. When substrate temperature is too high or diamond deposition pressure, second nucleation phenomenon will occur which destruct diamond films surface integrity; When substrate temperature is too low or sedimentary pressure is too small, hydrocarbon groups reaction rate is slow, diamond films growth rate is slow.4. The substrate bias speeds up the hydrocarbon group active reaction rate. Press- ure effect on the vacuum indoor reactive collisions rate to have an impact on diamond films growth rate. With the increase of substrate bias, diamond films growth rate becomes faster. But overvoltage will damage the equipment, and the diamond films growth rate is not obvious increased, therefore choose 700 V as diamond films growth bias.