[100]-textured growth of polycrystalline diamond films on alumina substrates by microwave plasma chemical vapor deposition

In order to grow diamond film on alumina ceramic, it is essential to control the diamond nucleation properly. Under a gas pressure lower than that used for growth, a high nucleation density of diamond films on alumina, as high as 108/cm2, is successfully achieved by microwave plasma-enhanced chemical vapor deposition method. Based on this, [100]-textured diamond films are successfully deposited on alumina by controlling the substrate temperature. From the results on SEM, XRD and Raman measurements, the substrate temperature has a strong influence on the textured growth and quality of diamond films on alumina substrates. Too low or too high temperature cannot obtain [100]-textured and good-quality films. The optimum substrate temperature range, for the growth of [100]-textured and good-quality diamond films on alumina, should be 800∼860 °C in our experiments.