High-performance low-leakage enhancement-mode high-K dielectric GaN MOSHEMTs for energy-efficient, compact voltage regulators and RF power amplifiers for low-power mobile SoCs

We have fabricated L
_G
=90nm high-K dielectric enhancement-mode (e-mode) GaN MOS-HEMT which shows low I
_OFF
=70nA/μm (V
_D
=3.5V, V
_G
=0V), low R
_ON
=490Ω-μm, high I
_D,max
=1.4mA/μm, and excellent power-added efficiency (PAE) of 80% at RF output power density (RF Pout) of 0.55W/mm (V
_D
=3.5V, f=2.0GHz). These results represent (i) >3.6X lower RON at equivalent breakdown voltage (BV
_D
) than industry-standard Si voltage regulator (VR) transistors, and (ii) >10% better PAE at matched RF Pout or >50% higher RF Pout at matched PAE than industry-standard GaAs RF power amplifier (PA) transistors, all at mobile SoC-compatible voltages. These results make GaN MOS-HEMTs attractive for realizing energy-efficient, compact voltage regulators and RF power amplifiers for mobile SoC. This work shows, for the first time, that the application space of GaN electronics can be expanded beyond the existing high-voltage power and RF electronics (e.g. automobile, power conversion, base-station, radar) to include low-power mobile SoCs.