Simulation Research On Planar Power Semiconductor Device Terminal Technology

Breakdown voltage is one of the main parameters for analyzing power semiconductor devices,and the use of terminal technology is a strong guarantee of breakdown voltage.Traditional power semiconductor devices usually use bevel molding technology.Modern power semiconductor devices,such as power MOSFETs,IGBTs,and MPS,which use silicon dioxide as a mask,diffuse into planar junctions.The terminal technology is no longer the conventional bevel modeling technology,but the so-called planar power semiconductor device terminal technology.This paper focuses on two typical planar power semiconductor device terminal technologies for optimal design and analysis.This paper designs a planar terminal structure that allows the device to withstand voltage up to 1200V.First,the mechanism of avalanche breakdown and several factors that affect the breakdown voltage of the device are theoretically analyzed.According to the relevant literature and domestic production levels of existing technologies,the designed terminal structure is defined as a composite structure with field plates plus field limiting rings.Second,according to the design requirements,combined with theoretical derivation,it was determined that the substrate concentration was 8.7e13 cm^-3 and the junction depth was6?m.And using Silvaco device simulation software and the limiting variable method to determine the relevant parameters of the terminal structure only the field ring,such as ring spacing,ring width,surface charge concentration and so on.By analyzing the electrical characteristics of the terminal structure when a single field is limited to a loop,the simulation optimization criteria for the ring spacing in the design are determined,and the number of field loops required for the structure is determined to be 7.Finally,the addition of the field plate structure and the optimization of the field oxygen thickness were completed.The comparison of the electric field and potential energy distribution was performed to determine the final parameters and the ideal simulation analysis results were obtained.In the research of this topic,since most of the structural design parameters do not have a specific design calculation formula,a large amount of simulation work is required.The simulation results show that the final voltage is 1415V and the terminal width is 375?m,which meets the design requirements.The research work of this thesis can provide an effective reference for similar design in the future.