Comparison of Surface Passivation Films for Reduction of Current Collapse in AlGaN/GaN High Electron Mobility Transistors

Three different passivation layers MgO, and were examined for their effectiveness in mitigating surface-state-induced current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). The plasma-enhanced chemical vapor deposited produced ∼70-75% recovery of the drain-source current, independent of whether or plasma chemistries were employed. Both the and MgO produced essentially complete recovery of the current in GaN-cap HEMT structures and ∼80-90% recovery in AlGaN-cap structures. The had superior long-term stability, with no change in HEMT behavior over 5 months aging.