A new Pd|HfO2|AlGaN|GaN metal-oxide-semiconductor (MOS) enhancement-mode high electron mobility transistor (HEMT) is fabricated with low-temperature sensitization, activation, electroless-plating, and two-step gate-recess approaches. Experimentally, a high positive threshold voltage Vth of 1.96 V, a very low gate leakage IG of 6.3·10-8 mA/mm, a high maximum extrinsic transconductance gm,max of 75.3 mS/mm, a high maximum drain saturation current ID,max of 266.9 mA/mm, and a high ON/OFF current ratio of 7.6·107 are obtained at 300 K. Moreover, the related temperature-dependent characteristics, over temperature ranges from 300 to 500 K, are comprehensively studied. The very low temperature coefficients on gate current, drain saturation current, transconductance, and threshold voltage confirm the thermal-stable capability of the studied device. Therefore, based on these advantages, the studied Pd|HfO2|AlGaN|GaN MOS structure is suitable for the development of high-performance HEMTs. Keywords: HfO2, AlGaN|GaN, metal-oxide-semiconductor, high electron mobility transistor, electroless plating, gate recess, threshold voltage.
A Novel GaN Metal-Insulator-Semiconductor High Electron Mobility Transistor Featuring Vertical Gate Structure
