Single-Event Damage Observed in GaN-on-Si HEMTs for Power Control Applications

The single-event damage observed in AlGaN/GaN high-electron mobility transistors (HEMTs) was investigated. For power control applications, normally off operation is achieved by p-type GaN gate material and its rated drain-source voltage of 600 V. Because of no gate insulator, single-event gate rupture is essentially excluded. Therefore, the HEMTs are expected to exhibit better immunity to heavy ions in comparison with SiC power MOSFETs. In the test results, two types of catastrophic failure modes were observed with different leakage current paths; one failure mode was caused by the introduction of a leakage current path between the drain and Si substrate via the buffer layer. The other was caused by the damage between the drain and source electrodes.