A Study On Dynamic Characteristics Of Wide Bandgap Semiconductor Power Devices

Semiconductor electronic device technology,as the cornerstone of promoting the development of social informatization,has been constantly changing and progressing in the past sixty years.The performance of traditional silicon(Si)material devices is gradually approaching the theoretical limit and cannot meet the current rapidly developing market needs.Wide bandgap semiconductor materials have a wide range of application prospects in the field of high-frequency and high-power power electronics due to their outstanding material properties.At present,the wide bandgap semiconductor power devices represented by gallium nitride(GaN)and gallium oxide(Ga₂O₃)are not mature enough,especially for the dynamic characteristics of GaN and Ga₂O₃ power devices,the efficiency and reliability of the devices are limited,which greatly hinders its large-scale commercial use.Based on the analysis of the dynamic characteristics of wide bandgap semiconductor GaN and Ga₂O₃ power devices,this paper conducts a systematic study of their dynamic characteristics,and evaluates the reverse recovery characteristics,dynamic on-resistance degradation characteristics and AC characteristics of the devices.It provides an important reference for guiding the further optimized design,preparation and practical application of the device.The main work is as follows:1.Designed a multi-functional hardware test system that can test the reverse recovery characteristics and on-resistance of the device.Using the principle of inductance volt-second balance,the device can generate a multi-pulse rectangular wave current,which can accurately obtain various dynamic characteristic parameters of the device.2.The factors affecting the reverse recovery characteristics of wide-bandgap semiconductor power diodes are comprehensively studied.The results show that the current slew rate and the reverse withstand voltage of the device play a major role in the reverse recovery,and the device conduction current has little effect on reverse recovery.Secondly,it comprehensively compares the reverse recovery advantages of GaN and Ga₂O₃ material devices over silicon carbide(Si C)and Si material devices,and characterizes the excellent performance of GaN and Ga₂O₃ diodes in switching applications.3.Because the traditional double-pulse test method is one-sided in the evaluation of the dynamic on-resistance of wide-bandgap GaN power devices,it cannot accurately reflect the changes in the on-resistance of the device.This paper designs a new multi-pulse test method to study the dynamic on-resistance characteristics of planar Al GaN/GaN heterojunction devices and vertical GaN PiN diode devices.The results show that the former will have obvious dynamic on-resistance degradation,which is especially serious during high-voltage and high-frequency operation.The latter fundamentally avoids the problem of dynamic on-resistance degradation due to the advantages of the device structure;Finally,the performance of the vertical GaN PiN diode in the high-frequency rectifier circuit is studied,and its high-frequency rectification capability is evaluated based on the half-wave rectifier circuit and the Lissajous I-V characteristic diagram.This paper used a new multifunctional test system to systematically characterize the reverse recovery characteristics of GaN and Ga₂O₃ power diode devices for the first time.The research summarized the dominant factors affecting its reverse recovery,and verified the outstanding reverse recovery characteristics of wide-bandgap semiconductor power devices;A new multi-pulse test scheme was designed to accurately characterize the on-resistance degradation difference of GaN power devices with different structures.The performance of GaN PiN diodes working in high-frequency rectifier circuits is evaluated,which provides an important reference for guiding the further optimized design,preparation and practical application of the devices.