Development of Compliant Substrates for GaN Epitaxy

We propose a six month Phase I research program aimed at developing compliant substrates for the epitaxy of GaN and AlGaN films. We present two alternate approaches one with silicon and the other with GaAs as the starting substrate material and a unique multilayer structure to be deposited using low pressure MOCVD. We propose to investigate an approach based on the use of SIMOX substrates. These compliant substrates will then be used to deposit thin layers of GaN followed by subsequent annealing to relax the structure. Thicker layers of GaN deposited on these structures will have a significantly reduced number of defects. We will at each step analyze the improvements in the defect reduction via X-ray and electron microscopy techniques. We will collaborate with Professor Subash Mahajan's group at CMU. He has significant expertise and resources in the defects analysis area.