Radiation Mechanism And Experimental Study Of Super Junction Devices

Super junction devices break the traditional “silicon limit” and have excellent electrical properties,which are expected to replace conventional power MOSFETs in the application of aerospace aircraft power supply.However,there are various high-energy rays and a large number of charged particles in the radiation environment of aerospace aircraft,which cause electronic devices to be prone to radiation effects and degrade their performance.As a result,the reliability of electronic systems is reduced and the service life is shortened,resulting in huge hidden dangers and cost waste.There are few relevant literatures on the study of the radiation effects of super junction devices and the research is not in-depth.Therefore,it is very meaningful to carry out radiation mechanism and experiment study of super junction devices in the paper.Based on the theory of super junction devices and radiation effects,this paper studies the total ionizing dose radiation effects and single event burnout(SEB)effect of super junction devices,and proposes the anti-radiation hardening schemes.The main contents are as follows:1.Study the total ionizing dose radiation effects of super junction devices by experiments and simulations,and the reinforcement designs are proposed.For the first time,the total ionizing dose radiation effects of conventional VDMOS and Super Junction Devices are compared.The experiment and simulation results show that the total ionizing dose radiation effects have almost same effect on the electrical characteristics of super junction devices and conventional VDMOS cells.Breakdown voltage and on-resistance is almost constant with the increase of the ionizing dose,but the threshold voltage decreases approximately linearly with the increase of the ionizing dose and the downward trend is similar.The total ionizing dose radiation effects on the breakdown voltage of the super junction device and the conventional VDMOS terminal are different.Although the breakdown voltage of both the super junction terminal and the field limiting ring structure terminal decreases with the increase of the ionizing dose,the degradation of the super junction terminal is smaller,and the anti-total ionizing dose radiation capability is stronger.Finally,two noval structures against the total ionizing dose radiation are proposed based on the super junction terminal,and it is proved that the terminal structure with a field plate added to the main junction is more resistant to the total ionizing dose radiation.2.The single event burnout effect is studied by simulating the P-pillar depth of the super junction devices,the P/N column charge imbalance of the super junction devices,and the angle of particles incident the super junction devices.The simulation results show that the influence of the depth of P-pillar on the anti-SEB ability of the super junction devices is related to the range of incident particles.When the range of particles is greater than the depth of P-pillar,the anti-SEB ability of super junction devices is independent of the depth of P-pillar.However,when range of the particle is less than the depth of Ppillar,there is an optimal value of the depth of P-pillar,under which stronger anti-SEB ability can be obtained.In the super junction devices,the anti-SEB ability can be improved if the P-pillar doping concentration is less than the N-pillar doping concentration,but the breakdown voltage drops due to the charge imbalance.The tradeoff between anti-SEB ability and voltage resistance can be achieved by optimizing P/N column doping.In this paper,the total ionizing dose radiation effects and single event burnout effect of super junction devices are studied systematically and deeply,which can provide valuable reference for the design of anti-radiation super junction products in the future.