In situ X-ray diffraction during MOCVD of III-nitrides

Nowadays Metal Organic Chemical Vapor Deposition (MOCVD) is the most frequently used fabrication process for growing III-V-nitrides. The missing ultra high vacuum (UHV) conditions narrow the window of possible in situ characterization techniques to only optical methods like spectroscopic ellipsometry (SE) and X-ray diffraction. We are able to observe the growing surface simultaneously with a multi wavelength ellipsometer and a X-ray diffraction (XRD) system mounted on an AIXTRON 200 RF-S reactor. Properties like crystal quality, composition, superlattice periodicity and strain relaxation of hexagonal GaN/AlGaN heterostructures are determined in situ using XRD. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.