Measurement And Analysis Of GaN HEMT's Parameter Degradation After Power Cycle

GaN HEMT(GaN High Electron Mobility Field Effect Transistor)as a representative of the new generation of wide bandgap semiconductor devices has gradually become a research hotspot of power electronic devices in recent years.Especially as a power semiconductor device,the reliability of GaN HEMT has always been the focus of researchers.The main research contents are as follows: The aging condition and aging mechanism of power GaN HEMT devices under high voltage and high current power cycle conditions are studied in this paper.The following aspects of work have been done:Firstly,aiming at the characteristics of fast switching speed,narrow normal operating voltage range and poor anti-interference ability of enhanced power GaN HEMT device,a switching characteristic test circuit is designed to provide circuit support for power cycle aging experiment.The design of switching characteristic test circuit focuses on reducing parasitic inductance.The main methods include: 1.Ensure the distance between gate drive output and device source electrodes is very compact to reduce parasitic inductance of gate source circuit and grid interference;2.Minimize the area of main circuit,reduce parasitic inductance of main circuit and minimize switching oscillation.Secondly,three kinds of GaN HEMT devices were tested by power cycle ageing experiment for one week.The static parameters such as output characteristic curve,threshold voltage and drain-source leakage current were measured regularly to clarify the degradation law of each parameter.Thirdly,by changing the frequency and duty cycle of gate driving signals,three GaN HEMT devices were experimented with power cycle aging for 7 days for the second and third time.The degradation results of the measured parameters were compared with those of the first aging experiment,and the effect of frequency and duty cycle of gate driving signals on the aging degree of GaN HEMT devices was clarified.Fourthly,the degradation data of the parameters of GaN HEMT device in thethird power cycle aging experiment are summarized and analyzed quantitatively.The degradation trend and degradation rate of some parameters of GaN HEMT device are obtained,and the influence of gate driving signal frequency and duty cycle on the aging results is compared.