Realization of both enhancement and depletion mode MOSFETs on GaN-on-Si LED epitaxial wafer

Abstract

In this letter, we propose, fabricate, and characterize both an enhancement mode (E-mode) and a depletion mode (D-mode) MOSFET on a standard LED epitaxial wafer based on silicon substrate for the first time. The devices are fabricated on the n-GaN layer or undoped-GaN layer of the LED epitaxial wafer by semiconductor manufacturing techniques. The working mode (E-mode or D-mode) of the device is dependent on the etching depths of the gate recess. The experiments show that the E-mode and D-mode MOSFETs possess a maximum output current density of 0.15 mA mm−1 and 4.6 mA mm−1 under the gate-to-source voltage of 8 V and drain-to-source voltage of 8 V, respectively. It is expected that such E-mode and D-mode MOSFETs achieved on GaN-on-Si LED epitaxial wafer should have potential applications in monolithic optical electronic integrated circuits.