Design Of A Super-junction VDMOS Device And Research On Its Radiation Effect

Super-Junction VDMOS（Vertical double-diffused MOSFET）,as a representative of high-voltage low-loss power discrete devices,relies on two-dimensional electric field technology to greatly improve the device by introducing a unique charge compensation structure（P-pillar）to the drift region.The contradictory relationship between the breakdown voltage and the on-state resistance significantly improves the working efficiency of the device,enables the device to work in the same voltage level environment with smaller size parameters,reduces the power loss of the device,and reduces the power consumption of the device.Automobiles,power supplies,and portable devices and other aspects have attracted wide attention.At the same time,these fields continue to put forward higher requirements for devices.Miniaturization,low power loss,and better dynamic performance are the development trends of future devices.In addition,satellites,space stations,military equipment and other application scenarios full of radiation environments are also suitable for the reliability of the device puts forward higher requirements.Therefore,how to reduce the specific on-state resistance of the device at the same voltage level and how to make the device work normally in the special scene with radiation are the common goals of people studying super-junction VDMOS.This paper mainly studies the 200 V super-junction VDMOS device and its radiation effect,aiming at the following contents:1.Based on the multiple epitaxy and multiple implantation process,the design of the cell region of the 200 V super-junction VDMOS device is studied,which mainly includes the following parts: First,the breakdown voltage and the specific process flow and specific parameters are determined based on the relationship between the on-state resistance ratios.Second,the reverse transfer capacitance characteristics of the super-junction VDMOS are studied.From the experimental simulation,it can be concluded that the non-uniform doping structure of the super-junction and the top p-buried layer structure can greatly reduce the reverse recovery capacitance of the device.2.Based on 200 V super-junction VDMOS,the research on single event effect is carried out.This paper mainly evaluates the radiation resistance of 200 V super-junction VDMOS by combining the mechanism of single event burnout and single event gate rupture.Afterwards,this paper studies the effects of non-uniform doping,buffer design,P-body design,p+plug region design,particle incident position and depth on the device’s resistance to single-particle capability in combination with specific process conditions,and proposes feasible reinforcement methods according to the results.3.Combined with the process flow and device parameters determined by the above research,the layout design of the super-junction VDMOS is drawn,and the layout design scheme of the super-junction VDMOS is given.In the layout design,the excellent switching characteristics of super-junction VDMOS and the requirements of radiation hardening are considered.The width and depth of the CT hole of the device and the critical dimension of the gate polysilicon,the concentration and morphology of the P-body region of the device are gived to improve the radiation resistance of the device.In addition,by introducing the P-bury structure,the capacitance characteristics and radiation resistance of the device can be improved at the same time.