Abstract

We have examined the correlation of gas phase species concentrations in a chemical vapor deposition (CVD) reactor with diamond film growth process parameters and film characteristics. The experiments were performed in a hot filament CVD reactor fitted for orifice sampling and resonantly enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry for gas analysis. The mass spectrometer was used to monitor the chemical species present immediately above the diamond growth surface. Stable products were monitored using electron impact ionization. REMPI was employed for the detection of radicals, including atomic hydrogen and methyl radical, since species such as ${\text{CH}}_{3^{+}}$ can be artificially produced by dissociative electron impact ionization of stable molecules. Measurements were made of the filament and substrate temperature dependence of the H, CH₃, CH₄, and C₂H₂ relative concentrations. Scanning electron microscopy and Raman spectroscopy were utilized to analyze diamond film morphology and quality.

© 1996 Optical Society of America