Design and Analysis of Insulate Gate Bipolar Transistor (IGBT) with P+/SiO2 Collector Structure Applicable to High Voltage to 1700 V

In this paper, we propose a new structure that improves the on-state voltage drop along with the switching speed in insulated gate bipolar transistors(IGBTs), which is widely applied in high voltage semiconductors. The proposed structure is unique that the collector area is divided by SiO₂ regions, whereas in existing IGBTs, the collector has a planar P+ structure. The process and device simulation results show remarkably improved on-state and switching characteristics. The current and electric field distributions indicate that the segmented collector structure increases the electric field near the SiO₂ edge which leads to an increase in electron current and finally a decrease in on-state voltage drop to 30% ~ 40%. Also, since the area of the P+ region decreases compared to existing structures, the hole injection decreases which leads to an improved switching speed to 30%.