A snapback-free shorted-anode insulated gate bipolar transistor with an N-path structure

• Shorted-anode/SA-IGBT without snapback effect is gradually followed with interest.
• A snapback-free SA-IGBT with an N-path structure is studied in this paper.
• Work mechanism and electrical characteristics of the N-path SA-IGBT are discussed.
• The better reverse conduction is obtained without sacrificing other properties.
• The softer reverse recovery property is obtained for the N-path SA-IGBT at diode mode.

A snapback-free field stop shorted-anode insulated gate bipolar transistor (SA-IGBT) with an N-path structure is proposed for the first time in this paper. The N-path structure is partially surrounded by the floating P-layer (P-float) and oxide layer in the backside of the wafer, which provides a direct path to the N-collector for electronic current and achieves shorter turn-off time. As demonstrated in numerical simulations, compared with the conventional field stop SA-IGBT, the proposed N-path SA-IGBT is able to completely suppress the snapback effect without causing extra performance fluctuations as long as the doping concentration of the N-path is low enough, while it also has a better reverse conduction ability and a much softer reverse recovery property at the same time without causing any on state loss or turn off speed degradation.