In Situ Raman Spectroscopy of a Single Crystal Diamond for Contactless Temperature Monitoring during Growth in a Microwave Plasma Reactor

We report the Raman spectrum measurement of a diamond single crystal during epitaxial growth in a microwave plasma reactor in a hydrogen‒methane mixture at various temperatures of the substrate. The crystal temperature is determined from the shift of the first-order Raman peak in the spectrum. It is shown that, compared to pyrometric methods, in situ Raman scattering enables more accurate measurement of the substrate temperature, which is critical for monitoring the CVD diamond synthesis process.