Demonstration of high threshold voltage Tri-gate hybrid ferroelectric gate stack GaN HEMT with 1.2 GW/cm2 Baliga's figure-of-merit and highly robust TDDB stability

Abstract

This work demonstrates a highly robust time-dependent dielectric breakdown (TDDB) lifetime analysis and high threshold voltage (Vth) in a tri-gate metal–insulator–semiconductor high-electron-mobility transistor (MIS-HEMT). The combination of tetramethylammonium hydroxide treated tri-gate and hybrid ferroelectric gate stack allows effective depletion of the 2-DEG channel by trapped charges in the hafnium oxynitride charge-trapping layer, resulting in a high threshold voltage (Vth) of 3.15 ± 0.2 V, a higher off-state breakdown voltage of 870 V, a low specific on-resistance (RON-SP) of 0.64 mΩ cm2, a high maximum drain current density (IDS-MAX) of 987 ± 10 mA/mm, and an excellent high-power figure-of-merit up to 1.2 GW/cm2. Finally, a TDDB test analyzes the gate insulator degradation of GaN-based tri-gate MIS-HEMTs. The device demonstrates an operating voltage of 12.02 V at a failure rate of 1% for a 10-year lifetime at room temperature by fitting the data with a power law, which is the highest value amongst reported GaN HEMTs.