GaN/Si(111) Device Defects and Degradation Mechanisms

The origin of the leakage current has been explained in the present investigation by impurity states near the Si interface. However, the present investigation has discovered that commercial grade GaN/Si(111) has surfaces that include smooth areas with features; there are usually anti-phase domains with electron channeling patterns which are not sharp, and with threading dislocation densities in the 108 cm-2 range. The ultimate performance goal for GaN/Si high voltage switches is to approach the electrical performance characteristics of homoepitaxial GaN/GaN switches. A necessary condition is the elimination of APBs and the reduction of threading dislocations and oval defects.