Nitrogen and hydrogen content, morphology and phase composition of hot filament chemical vapor deposited diamond films from NH3/CH4/H2 gas mixtures

In this paper, we present our studies related to phase composition, nitrogen and hydrogen content and morphology of diamond films deposited by hot filament chemical vapor deposition from NH3/CH4/H2 gas mixtures. Raman spectroscopy is used to study the phase composition and chemical nature of the diamond films. The appearance of a nitrogen associated 1190 cm− 1 peak and carbon‑nitrogen bonding configuration are discussed in light of NH3/CH4 ratios. Scanning electron microscopy reveals nano- and microcrystalline structure of diamond films, depending on the ratio of NH3/CH4 in the gas mixture. Secondary ion mass spectroscopy (SIMS) is used to study the extent and uniformity of nitrogen and hydrogen content within the films. An increase in nitrogen concentration in the films is primarily attributed to the increased NH3/CH4 ratio and also to the microstructure of the deposited film. SIMS profiles of hydrogen reveal a correlation between hydrogen and nitrogen in the diamond films, from which nitrogen bonding configuration can be studied.