Reliability Assessment of InAlN/GaN HFETs With Lifetime $8.9\times 10^{\mathrm {6}}$ h

Based on the three-temperature 30 V DC stress tests, the reliability of InAlN/GaN heterostructure field-effect transistors (HFETs) on SiC substrate was assessed for the first time. Using a failure criterion defined as 20% reduction in zero-gate-voltage drain current (Idss), the activation energy was estimated to be 1.94 eV, and the median time to failure was estimated to be 8.9 × 10
⁶
h at junction temperature of 150°. Moreover, the high temperature material storage indicates that the lifetime of InAlN/GaN HFETs can be further prolonged by the optimization of device process, such as introducing LPCVD SiN or ALD Al
₂
O
₃
as gate dielectric layer.