Etch Depth Study for Step-Etched Junction Termination Extensions in Vertical GaN Devices

This work reports on the optimal dose for a step-etched single-zone junction termination extension by means of a multi-point study on etch depth. Breakdown and device characteristics are reported on over one hundred devices for each dataset to determine a statistically significant representation of the population. Electroluminescence imaging during avalanche breakdown confirms the point at which the JTE switches from full depletion to partial depletion, which corresponds to the maximum breakdown.