Simulation Model Development for Packaged Cascode Gallium Nitride Field-Effect Transistors

Chih-Chiang Wu,Shyr-Long Jeng

doi:10.3390/cryst7080250

Abstract

This paper presents a simple behavioral model with experimentally extracted parameters for packaged cascode gallium nitride (GaN) field-effect transistors (FETs). This study combined a level-1 metal–oxide–semiconductor field-effect transistor (MOSFET), a junction field-effect transistor (JFET), and a diode model to simulate a cascode GaN FET, in which a JFET was used to simulate a metal-insulator-semiconductor high-electron-mobility transistor (MIS-HEMT). Using the JFET to simulate the MIS-HEMT not only ensures that the curve fits an S-shape transfer characteristic but also enables the pinch-off voltages extracted from the threshold voltage of the MIS-HEMT to be used as a watershed to distinguish where the drop in parasitic capacitance occurs. Parameter extraction was based on static and dynamic characteristics, which involved simulating the behavior of the created GaN FET model and comparing the extracted parameters with experimental measurements to demonstrate the accuracy of the simulation program with an integrated circuit emphasis (SPICE) model. Cascode capacitance was analyzed and verified through experimental measurements and SPICE simulations. The analysis revealed that the capacitance of low-voltage MOSFETs plays a critical role in increasing the overall capacitance of cascode GaN FETs. The turn-off resistance mechanism effectively described the leakage current, and a double-pulse tester was used to evaluate the switching performance of the fabricated cascode GaN FET. LTspice simulation software was adopted to compare the experimental switching results. Overall, the simulation results were strongly in agreement with the experimental results.

Highlights

Gallium nitride (GaN) field-effect transistors (FETs) exhibit high performance levels that render them suitable for high-switching, high-temperature applications
The MIS-HEMT used in this study was a 600-V, TM3 with an R
A simple behavioral model was developed by applying experimentally-extracted parameters for cascode GaN FETs

Summary

Introduction

Gallium nitride (GaN) field-effect transistors (FETs) exhibit high performance levels that render them suitable for high-switching, high-temperature applications. Using GaN in power design fields involves certain design challenges [1]. To assist designers in the switching power application of GaN FETs, a simulation program with an integrated circuit emphasis (SPICE) model must be constructed. Several power conversion GaN FET device models have been reported [2,3,4,5,6]. These models were partially collated and analyzed in [2]. Many researchers use behavioral models because they can be developed by applying experimentally extracted static current–voltage (I–V)

Objectives

Methods

Conclusion