Effect of high temperature, high pressure annealing on GaN drift layers for vertical power devices

In this work, we evaluate the effect of the novel symmetric multicycle rapid thermal annealing (SMRTA) process on both Mg ion implanted and non-implanted thick unintentionally doped GaN drift layers for vertical power devices. The typical p-type behavior and restoration of implant damage are observed in implanted samples, but on non-implanted samples a reduction in background carrier concentration and associated reduction in leakage current and increase in breakdown voltage is observed. This indicates that the capping/annealing process itself is not detrimental to the crystal, and the annihilation of native point defects in the process has beneficial effects for device structures.