High mobility and high crystalline-quality chemical-vapor-deposition grown homoepitaxial diamond

Abstract

We have grown a high-crystalline-quality homoepitaxial diamond (001) layer by using microwave plasma chemical vapor deposition. We did not detect any impurities, such as H, B, N and O, in the homoepitaxial layer by secondary ion-mass spectroscopy. The full width at half maximum of the Raman diamond-related peak was as low as 2.35 cm −1. The Raman results showed that in the growth temperature range, T g, from 650 to 730 °C, local crystalline quality deteriorated with the T g and that for T g>730 °C, it improved with the T g. However, as the T g was increased to above 780 °C, almost all the surface became covered with unepitaxial crystals, which obstructed hole conduction on the H-terminated surface. Consequently, we obtained high Hall mobility at a T g's of approximately 660 and 766 °C. At room temperature, we obtained a Hall mobility of 814 cm 2/Vs in the air.