The focus of my PhD project work at the Cambridge Centre for Gallium Nitride was on the characterisation of GaN-based HEMT and LED structures which were both grown on the same 6″ and 8” silicon wafer. The combined standard materials characterisation techniques in the project such as scanning electron microscopy, X-ray diffraction, CV analysis, photoluminescence studies and atomic force microscopy allowed us to build up an accurate profile of the entire device structure, which is critical for subsequent device optimisation. These design building blocks enabled us to demonstrate the operation and performance of the first monolithically-integrated LED and HEMT on large-area semiconductor wafers.
