Correlation between RF and DC reliability in GaN high electron mobility transistors

Although RE life test is a more definitive technique for RE FET reliability estimation, DC life test is often preferred over RE life test due to its simplicity. In this work, we study how degradation of DC performance in GaN high electron mobility transistors correlates to RE performance degradation in both RE and DC life tests. We show that DC life tests can seriously underestimate device lifetime in GaN HEMTs due to lower instantaneous V_DG. The impact of gate current degradation on output power degradation is also discussed.