The influence of nitrogen and oxygen on the high nucleation density diamond growth

Abstract

High nucleation density diamond films were grown on silicon substrates with a high-density nano-diamond suspension crystal seed. By keeping other parameters constant and varying the amounts of oxygen and nitrogen added, diamond films were grown using MPCVD equipment. The composition, structure, and properties of the diamond films were characterized using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results show that the average grain size of samples grown with added oxygen and nitrogen as assisting gases significantly decreased, exhibiting improved crystallinity and fewer defects. However, there was a certain increase in the relative content of graphite, along with the presence of trans-polyacetylene. Furthermore, as the ratio of oxygen to nitrogen increased, the samples exhibited better crystallinity, fewer defects, and overall higher growth quality. The relative content of graphite initially increased, then decreased, and increased again.