The Research On ESD Reliability Of Self-protected SOI-LIGBT Devices

Silicon on insulator lateral insulated gate bipolar transistor(SOI-LIGBT)has become one of the core devices to promote the development of power integrated circuit field because of its many advantages,such as large current density,high breakdown voltage,fast switch speed and high integration.As years of development,the electrical properties of SOI-LIGBT have been greatly improved,but as the output terminal,the ESD(Electro-Static Discharge)response characteristics of self-protected SOI-LIGBT have not been reported,limits the application and development of SOI-LIGBT,thus,it is urged to investigate the reliability of self-protected SOI-LIGBT under ESD stress.Based on the establishment of ESD test platform and simulation platform,firstly,the response characteristic mechanism including forward blocking region,voltage snapback region,voltage holding region and secondary breakdown region under the ESD stress are analyzed,then the influence of different anti-latch-up structures are investigated,including anode with N+/P+ section structure?P-body package beak structure?cathode with trench structure and poly segmented structure;the influence of different optimized turn-off characteristic structures are investigated,including shorted anode structure?segmented anode structure and anode with P+/P-section structure.Finally,two high ESD self-protected structure are proposed,the secondary breakdown current of cathode N+ auxiliary trigger structure increased by 24%,and the ESD robustness of segmented N-buffer structure increased by 11.6%.The degradation of self-protected SOI-LIGBT electrical parameters under different repetition ESD stress are also studied in this paper,results show that trigger voltage of device is increased and secondary breakdown current is reduced with the rising edge and falling edge of ESD pulse become smoothly and voltage holding time become longer,larger pulse amplitude have little impact on the threshold voltage,the conduction resistance and breakdown voltage,but saturation current and secondary breakdown current are decreased.