Analysis of Real-Time Monitoring Using Interference Effects

Abstract
The interference effect, which is measured as a temperature oscillation by a narrow optical band-pass pyrometer during GaN growth in metalorganic chemical vapor deposition (MOCVD), was analyzed by calculating the transmittance and the reflectance. The results of the calculations showed that the attenuation of the oscillation amplitude with increasing thickness was not caused by the absorption of the growing layer. To explain this attenuation, the thickness fluctuation within the measured area was proposed. The thickness fluctuation and the growth rate of the growing layer are reflected on the trace of transmittance using the present real-time monitoring technique, which observes the interference effect.