Analysis and resolution of a thermally accelerated early life failure mechanism in a 40 V GaN FET

Abstract An early life failure mechanism was discovered on a 0.25-µm 40 V GaN FET technology. Through accelerated life testing (ALT), it was determined that the early life failure mechanism was thermally accelerated with a high activation energy, which means that it is not a concern a normal operating conditions up to the maximum rated junction temperature. Subsequent improvements to the process resulted in elimination of the early life failure mechanism. With the improved process, single-mode ALT lifetime distributions and excellent reliability performance down to low failure fractions were demonstrated.