The regulation effect of trace amount of oxygen on the properties of p-type boron-doped diamond

The light doping behavior of boron in microwave plasma chemical vapor deposition diamond films by trace oxygen was investigated. As the oxygen concentration (O/C) increased from 0 to 5%, the growth rate of the diamond film first decreased and then increased. When oxygen was added during the diamond doping process, the suppression of boron doping and the improvement of crystal quality could be observed, and there was a significant suppression of residual nitrogen. Hall effect measurement results show that under the condition of O/C = 3%, high mobility and high quality diamond films can be obtained with a growth rate of 9 μm/h. This work shows that a trace amount of oxygen can compensate the crystal strain brought by boron doping and improve the crystal and surface quality. This technology can obtain high-quality and thick boron-doped diamond films with acceptable mobility, which are suitable for future advanced optoelectronic device applications.