Research On Dynamic On-resistance Testing And Application Methods Optimization Of Enhanced-mode GaN Device

As a wide band gap semiconductor device,gallium nitride(GaN)high electron mobility transistor(HEMT)has great advantages and potential in the electrical parameters such as working voltage,switching frequency and temperature tolerance.But in the current research and application,it is found that there are a series of reliability problems under high voltage and high frequency.The current collapse effect or dynamic on-resistance is the most significant phenomenon,which will greatly increase the on resistance of the device,and then affect the efficiency and working life of the whole system.The traditional dynamic parameter test of GaN device adopts double pulse test(DPT).This method is not suitable for in-depth analysis of the factors and variation rules that affect the dynamic on-resistance of GaN device.Therefore,the main factors that affect the dynamic on-resistance are determined firstly according to the mechanism analysis of the dynamic conduction resistance of GaN device.Then,the multi working conditions dynamic on-resistance test circuit is designed and the test experiment is carried out according to the influencing factors.The experimental data are analyzed and the specific change rules of the dynamic on-resistance of GaN device are given.Finally,an optimization method is proposed to consider the dynamic on-resistance of GaN device.Firstly,the mechanism of dynamic on-resistance of enhanced GaN device is analyzed,and the main factors that affect the dynamic on resistance are determined.These factors are taken as experimental test variables.On the premise that the same test circuit includes all the above variables,a multi condition dynamic on-resistance test circuit based on four switches Buck?Boost(FSBB)circuit is proposed,the principle and test mode of the test circuit are analyzed and introduced.Secondly,according to the difference of device type and structure,the enhanced GaN device is divided into Cascode type,common monomer enhanced type and improved monomer enhanced type.Three GaN devices with the same voltage and current level are selected to carry out the experimental test,record the experimental data and calculate and process the data,and then integrate and analyze the experimental results.The dynamic on-resistance of different types of enhanced GaN devices varies with the same variable and the same type of enhanced GaN device varies with different variables.Finally,based on the variation law of dynamic on-resistance of different types of enhanced GaN device,combined with the practical application conditions,the optimization methods of dynamic on-resistance are proposed,which mainly includes the application conditions of GaN device adaptation and the accurate quantification of the on-state loss calculation method of GaN device.The theoretical calculation and experimental verification are carried out for the on-state loss.The conclusion is drawn that the proposed calculation method is correct and effective.