Device Technologies of GaN-on-Si for Power Electronics: Enhancement-Mode Hybrid MOS-HFET and Lateral Diode

Abstract

In this paper, a high performance enhancement-mode (E-mode) Al2O3/GaN hybrid MOS-HFET and a novel AlGaN/GaN lateral diode are experimentally demonstrated. Based on the proposed approach to engineer the dielectric/GaN positive interface fixed charges ( Q it+) by postdielectric annealing, the E-mode metal–oxide–semiconductor heterojunction field-effect transistor (MOS-HFET) obtains a better tradeoff between the threshold voltage ( V TH) control and drain current drive capability due to the significant suppression of Q it+ and the associated remote scattering effect. Owing to the uniquely high V TH and gate swing, the E-mode MOS-HFET exhibits respectable higher faulty turn on immunity that is prone to improve the reliability of the device in power switching applications and simplify the gate driver design. On the other hand, by featuring a new turn-on mechanism of MIS-gate-controlled 2-D electron gas (2DEG) channel, the diode exhibits ultralow turn-on voltage and reverse leakage current, which are beneficial to lowering the conduction loss and off-state power consumption of GaN-on-Si power diodes. Moreover, the diode is compatible with E-mode hybrid MOS-HFET, which is promising for realizing full-GaN single-chip power ICs.