Contactless characterisation techniques for verification of (AlGaN/GaN) device heterostuctures quality

Summary form only given. C-V measurements in a range of frequencies (80 Hz -10 MHz) and appropriate modelling were performed. The C and G versus frequency characteristics of MOVPE-grown nitride epitaxial structures were measured in a range of DC biases and the results were fitted to the model. The distributed elements equivalent circuit model for the series resistance and the Schottky junction admittance was used, allowing study of the carrier concentration distribution over the layer thickness, deep level relaxation phenomena and the determination of other parameters such as layer shunt resistance, resistivity and carrier mobility. The epitaxial layer sheet resistance was also determined by measurement of the complex reflectance coefficient of the scattering matrix performed at 4.5 GHz.