In situ Analysis of the Raman Diamond Line. Measurements in the Visible and UV Spectral Range

Abstract

Raman spectroscopy is the most frequently used tool to characterize diamond films prepared by various deposition methods. Hence, in situ Raman monitoring of the growth of plasma CVD diamond films may contribute to the understanding and the control of the growth process. As an attempt to improve our previous in situ Raman measurements, a new spectrometer is used, specifically designed for this application and optimized for analysis in the UV spectral range. In this paper the first results of this in situ analysis are presented and compared to those obtained with a more usual excitation in the visible spectral range. Careful temperature measurements during diamond deposition are made both using the temperature induced shift of the lines arising from the substrate and from the Stokes to anti-Stokes intensity ratio. Then, the frequency of the diamond line is related to stress incorporation within the films. It is shown that there is a large stress gradient within the film thickness.