Characteristics of β-(AlxGa1−x)2O3/Ga2O3 dual-metal gate modulation-doped field-effect transistors simulated by TCAD

Abstract

β-(AlxGa1−x)2O3/Ga2O3 modulation-doped field-effect transistors (MODFETs) with a dual-metal gate (DMG) architecture are designed, and the electrical characteristics of the DMG device are investigated in comparison with the single-metal gate (SMG) device by the Technology Computer-Aided Design (TCAD) simulation. The results demonstrate that the DMG MODFETs possess a superior transconductance (gm), current gain cut-off frequency (fT), and power gain cut-off frequency (fMAX) than those of SMG transistors, which is attributed to the regulated channel electric field by a DMG structure. With a gate length of 0.1 μm, the peak values of fT/fMAX of the designed DMG MODFET are obtained as 48.6/50.6 GHz, respectively. Moreover, a comprehensive thermal analysis is conducted between the SMG and DMG devices under steady-state and transient conditions. The DMG MODFET exhibits a lower maximum temperature than the SMG counterpart due to the reduced channel electric field, each subjected to the same power dissipation. This finding underscores the potential of the β-(AlxGa1−x)2O3/Ga2O3 MODFET with the DMG architecture as a promising approach for high-power radio frequency operations.