A Novel GaN Metal-Insulator-Semiconductor High Electron Mobility Transistor Featuring Vertical Gate Structure

Abstract

A novel structure scheme by transposing the gate channel orientation from a long horizontal one to a short vertical one is proposed and verified by technology computer-aided design (TCAD) simulations to achieve GaN-based normally-off high electron mobility transistors (HEMTs) with reduced on-resistance and improved threshold voltage. The proposed devices exhibit high threshold voltage of 3.1 V, high peak transconductance of 213 mS, and much lower on-resistance of 0.53 mΩ·cm2 while displaying better off-state characteristics owing to more uniform electric field distribution around the recessed gate edge in comparison to the conventional lateral HEMTs. The proposed scheme provides a new technical approach to realize high-performance normally-off HEMTs.

Performance improvement of enhancement-mode GaN-based HEMT power devices by employing a vertical gate structure and composite interlayers*

“…To investigate the avalanche breakdown effect, the Selberherr's impact ionization model is used to simulate the off-state characteristics. The physical models and device-related parameters used in the simulations, such as average electron mobility and electron saturation velocity (see table 1), are first calibrated by benchmarking with experimental I-V characteristics of the fabricated HEMT device [21], as shown in figure 2. The mismatch for the on-resistance is kept within 5%, which confirms the validity of the simulation results.…”

“…In a previous report, we have proposed a novel E-mode scheme by transposing the gate channel orientation from a long horizontal one to a short vertical one, which is called vertical gate HEMT (VG-HEMT) [21]. The main benefits include a relatively short gate channel originating from the low-mobility trenched region, hence resulting in an effectively reduced device R on , and also less sensitivity of V th variation to the recessed depth error.…”

AlGaN/GaN magnetic sensors featuring heterojunction 2DEG channel

“…In this work, AlGaN/GaN horizontal Hall sensor is demonstrated by theoretical simulation and practical fabrication work. The three dimensional (3D) structure simulation are employed to analyse the device characteristics, while the optimised GaN micro/nano processing technology are used to significantly improve the device performances [13,14]. The fabrication process and testing method of AlGaN/GaN Hall sensor are introduced in detail.…”

Editorial for the Special Issue on Wide Bandgap Based Devices: Design, Fabrication and Applications

“…Three papers [ 1 , 2 , 3 ] deal with RF power electronics for future 5G applications and other high-speed high-power applications. Nine of the papers, [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], explore various designs of wide bandgap high power devices. The remaining papers cover various applications based on wide bandgaps, such as ZnO Nanorods for High Photon Extraction Efficiency of GaN-Based Photonic Emitter [ 13 ], InGaZnO Thin-Film Transistors [ 14 ], Wide Band Gap WO 3 Thin Film [ 15 ], Silver Nanorings [ 16 , 17 ] and InGaN Laser Diode [ 18 , 19 , 20 ].…”

“…The contribution of each buffer layer related to vertical leakage and breakdown voltage could be identified. Sun et al [ 7 ] proposes a new approach to realize normally-off GaN HEMTs using TCAD. The concept is based on the transposition of the gate channel orientation from a long horizontal one to a short vertical one.…”