In-situ and real-time monitoring of MOCVD growth of III-nitrides by simultaneous multi-wavelength-ellipsometry and X-ray-diffraction

Abstract

Metal Organic Chemical Vapor Deposition (MOCVD) is nowadays the most frequently used industrial method for growing III-nitrides. The possible spectrum of in-situ diagnostic tools is quite narrow because the MOCVD growth process excludes all techniques based on ultra high vacuum conditions. Therefore, only optical methods like spectroscopic ellipsometry and X-ray diffraction give the possibility to observe and analyse the growing surface in-situ. We attached simultaneously a multi wavelength spectroscopic el-lipsometer and a X-ray diffraction system to our reactor and could determine parameters like growth rate and layer composition from both techniques. On the one hand the optical measurement gives surface sensitive information about the sample. On the other hand the measurement of the diffraction peak of hexagonal GaN and related alloys during growth gives additional information about the entire structure and the crystal quality.