Physics-Based TCAD Simulation and Calibration of 600 V GaN/AlGaN/GaN Device Characteristics and Analysis of Interface Traps.

Yu-Lin Song,Manoj Kumar Reddy,Luh-Maan Chang,Gene Sheu

doi:10.3390/mi12070751

Yu-Lin Song, Manoj Kumar Reddy + Show 2 more

Open Access

https://doi.org/10.3390/mi12070751

Copy DOI

Journal: Micromachines	Publication Date: Jun 26, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Asian University, National Taiwan University

Abstract

This study proposes an analysis of the physics-based TCAD (Technology Computer-Aided Design) simulation procedure for GaN/AlGaN/GaN HEMT (High Electron Mobility Transistor) device structures grown on Si (111) substrate which is calibrated against measurement data. The presence of traps and activation energies in the device structure will impact the performance of a device, the source of traps and position of traps in the device remains as a complex exercise until today. The key parameters for the precise tuning of threshold voltage (Vth) in GaN transistors are the control of the positive fixed charges −5 × 1012 cm−2, donor-like traps −3 × 1013 cm−2 at the nitride/GaN interfaces, the energy of the donor-like traps 1.42 eV below the conduction band and the acceptor traps activation energy in the AlGaN layer and buffer regions with 0.59 eV below the conduction band. Hence in this paper, the sensitivity of the trap mechanisms in GaN/AlGaN/GaN HEMT transistors, understanding the absolute vertical electric field distribution, electron density and the physical characteristics of the device has been investigated and the results are in good agreement with GaN experimental data.

Highlights

Gallium nitride (GaN) is one of the superior materials for high frequency and highpower devices for future needs [1,2,3,4,5,6,7,8]
GaN material comes from the III-V group materials which possess the piezoelectric property and spontaneous property in nature, GaN devices such as HEMTs, Metal Insulator Semiconductor HEMTs (MIS-HEMTs) and Schottky Barrier Diodes (SBDs) are profitable from the presence of large channel charge density (~1 × 1013 cm−2) at the interface of AlGaN and undoped GaN (Two-Dimensional Electron Gas (2DEG)) region with unintentional doping in the device structure [9,10,11,12,13,14]
GaN HEMT devices have proven to be the best candidate for operations in critical environments such as high temperature [15,16,17]

Summary

Introduction

Gallium nitride (GaN) is one of the superior materials for high frequency and highpower devices for future needs [1,2,3,4,5,6,7,8]. GaN HEMT devices have proven to be the best candidate for operations in critical environments such as high temperature [15,16,17] This is because of the key features of the device such as wider bandgap, high saturation velocity, very high breakdown voltage and a very good thermal conductivity [14,15,16,17,18,19,20,21]. The procedure of this detrapping and trapping follows the principles of Shockley Read Hall theory which explains the connections between the free carriers The key parameters such as fixed charge, the energy level of a donor-like traps, buffer activation energy, barrier height and tunneling coefficient for Schottky gate are key parameters for the understanding of calibration and optimization of HEMT devices

Simulation Setup

Self-heating effect

Findings

Schottky Barrier Height