Identification of defects and impurities in chemical-vapor-deposited diamond through infrared spectroscopy

Abstract

Hydrogen-, oxygen-, and nitrogen-related defects in chemical-vapor-deposited (CVD) diamond have been observed by infrared spectroscopy and found to affect optical absorptions in spectral regions of commercial interest. The origin of absorptions in the infrared spectrum at 2820 and 2833 cm−1, which have been observed previously without being understood, have been assigned. The presence of these absorptions and the evidence of oxygen and nitrogen incorporation in CVD diamond have important implications for both the design of CVD diamond growth systems and the design of processes involving oxygen addition. In films which contain high hydrogen concentrations (≳0.2 at. %), some evidence has been found indicating the presence of a hydrogen environment, not present in films with lower hydrogen contents, which may be related to sp2-bonded carbon.