Extending the bounds of performance in E-mode p-channel GaN MOSHFETs

Abstract

Abstract-An investigation of the distribution of the electric field within a normally-off p-channel heterostructure field-effect transistor in GaN, explains why a high requires a reduction of the thickness of oxide and the GaN channel layer. The trade-off between on-current and , responsible for the poor in E-mode devices is overcome with an additional cap AlGaN layer that modulates the electric field in itself and the oxide. A record of is achieved with a greater than in the designed E-mode p-channel MOSHFET, which is more than double that in a conventional device.

An E-Mode p-Channel GaN MOSHFET for a CMOS Compatible PMIC

“…2 (b) that the introduction of alters the direction of the electric field in the oxide. This is of crucial benefit that reverses the behaviour of with respect to as opposed to that in the conventional device [19].…”

“…These choices can lead to deterioration of the performance and reliability of the power devices by reduction in density of the 2DEG/2DHG respectively. Moreover, even with a recessed gate, we have earlier demonstrated a trade-off between the threshold voltage and the on-current in the conventional p-channel MOSHFET that can be addressed by a thin AlGaN cap layer beneath the gate, to achieve better control [19]. In this work, the dependence of the electrical characteristics of a p-channel GaN MOSHFET on gate length is investigated on a platform that is fully compatible with a power device in PSJ technology.…”

A Comprehensive Review of Recent Progress on GaN High Electron Mobility Transistors: Devices, Fabrication and Reliability

“…Among of them, the GaN MOS or MIS (metal-insulator-semiconductor) HEMTs has drawn most of the attention [9,14,28,43], so do the MISHEMTs with high-K gate dielectric [17,31,44]. Other new devices with a regrowth of AlGaN layer [41], or a regrowth of GaN drift channel layer [45] have also been reported. The MIS HEMT has the advantages over the Schottky gate GaN HEMT in terms of gate leakage and gate swing [46].…”

“…Ever since the initial demonstration of the enhancement-mode AlGaN/GaN HEMT in 1996 [36] and furthermore in 2000 [37], several approaches have been used to make normally-OFF GaN-based HEMTs as reviewed previously [38] and more recently [8,39]. Besides the hybrid approach with GaN HV-HEMT and Si LV-MOSFET in a cascade configuration, AlGaN/GaN-on-Si HEMTs with direct GaN gate control [40,41] have attracted much attention commercially in the recent years due to its size thus cost. GaN-on-Si is acknowledged as a promising device platform for further exploration of commercial high-power modules with higher power density [4,9,33,34].…”

Modelling the threshold voltage of p‐channel enhancement‐mode GaN heterostructure field‐effect transistors

“…Moreover, as opposed to (1), the term t ox ℰ ox in (9) bears a negative sign. This is owing to the fact that in this heterostructure, there is an additional polarisation sheet charge density σ cap , introduced by the AlGaN cap layer, which is responsible for a change in the direction of electric field in the oxide layer [14]. An application of Gauss' law at the interfaces (A), (B), and (C) gives…”