Study On The Mechanism And Characteristics Of 1.7 KV RC-IGBT

The Reverse Conduction IGBT(RC-IGBT)can reduce the parasitic inductance and improve the reliability and efficiency of the inverter.By introducing n+shorted region into the p+ collector region on the back of IGBT,RC-IGBT can realize forward and reverse conduction,reduce chip area,and reduce process cost.However,the introduction of n+shorted region makes RC-IGBT have the snapback phenomenon during IGBT conduction,resulting in high conduction power consumption of the device.Therefore,to solve this problem,an improved RC-IGBT(Reverse-Conducting IGBT with a Floating P-Region and a Shallow Trench isolated region,STFP RC-IGBT)structure with shallow trench isolation region and p-floating region in this thesis.The operation mechanism,characteristics and reliability of the STFP RC-IGBT are investigated by using Sentaurus TCAD simulation software with 1.7 kV voltage level as an example.The main research of this thesis is as follows:Firstly,the forward and reverse operation principle of the conventional RC-IGBT,and on the basis of the conventional RC-IGBT and TFP RC-IGBT(Reverse-Conducting IGBT with an Oxide Trench placed between the n-collector and the p-collector and a Floating P-Region sandwiched between the n-drift and the n-collector),the STFP RC-IGBT is proposed in this paper,analyzed its structural characteristics and process flows,and the forward and reverse operation mechanism are also analyzed,the p-float region will blocking the electron flow into the n+shorted region and thus suppressed the snapback phenomenon during the IGBT conduction.Secondly,the forward and reverse characteristics of the STFP RC-IGBT were studied,and the influences of key structural parameters on the characteristics of the STFP RC-IGBT are analyzed,the sensitive parameters causing the snapback phenomenon of IGBT are discussed,and the optimal structural parameters are extracted,and the influence of carrier lifetime and temperature on the forward and reverse characteristics of the STFP RC-IGBT are analyzed.Compared with the conventional RC-IGBT and TFP RC-IGBT,the STFP RC-IGBT has a superior VCEsat-Eoff and VF-JRM compromise relationship.Lastly,the reliability of the STFP RC-IGBT was studied,such as,short circuit,latch-up and dynamic avalanche.In addition,the influence of the key structural parameters on the reliability of the STFP RC-IGBT was studied.Compared with the conventional RC-IGBT and TFP RC-IGBT,the STFP RC-IGBT has higher ability to withstand short circuit,latch-up and dynamic avalanche.The research results have certain reference value for the research and development of RC-IGBT.