Parameter Optimization And Process Control Of CAL Power Diode

Power semiconductor devices are divided into switching devices and power rectifiers.Since the birth of the first thyristor in the 1950s,switching devices have rapidly developed.Especially with the emergence of modern power semiconductor devices such as power MOSFETs and IGBTs,the ability of the power system to operate at higher frequencies is limited by the switching characteristics of the power rectifier tube.In order to develop synchronously with high-performance switching devices,the performance of power rectifiers needs to be improved.High-quality diodes require low forward voltage drop,short reverse recovery time,low reverse recovery peak current,and large reverse recovery softness factor.Therefore,it is of great practical significance to study the reverse recovery characteristics of power diodes and optimize the distribution of carriers.Firstly,the basic structure,working principle and main parameters of FRD are analyzed,and the combination of theoretical calculation and computer simulation to determine the vertical structural parameters are used in the paper.Secondly,the lifetime control technologies including whole lifetime control and axial lifetime control?CAL?.By comparing various lifetime control technologies,the axial lifetime control is determined.Thirdly,according to the designed structure parameters,by using the process simulation software SILVACO TCAD,the process of realizing the structure FRD is simulated and the process parameters and process conditions are determined.Fourthly,ion implantation is used to simulate the proton irradiation process of CAL.According to the relevant literature,two proton irradiations are used to achieve two low-lifetime areas within the FRD.The proton irradiation is determined by analyzing the influence of the forward conduction voltage drop V_F,reverse recovery time t_rr,reverse recovery peak current I_RR,and reverse recovery softness factor S under the condition of one-time proton irradiation and two-time proton irradiation.The optimum process conditions for primary proton irradiation are:When the irradiation energy is 2.36MeV and the irradiation dose is 5e10cm^-2,the softness factor is 0.76,the on-state voltage drop is 2.3V,the reverse recovery time is 234ns,and the reverse recovery peak current is 41.2A;The optimum process conditions for the two proton irradiations are:when the first irradiation energy is 0.8MeV and the second proton irradiation energy is3.33MeV,the softness factor is 2.06 and the reverse recovery time is 127ns,voltage drop is2.53V,reverse recovery peak current is 32.7A.In this paper,the parameters of the 800V PIN diode are designed.The changes of the parameters of the PIN diode with the irradiated energy and the irradiation dose are analyzed by the simulation and analysis of the proton irradiation and two proton irradiation.