A novel carrier accumulating structure for 1200V IGBTs without negative capacitance and decreasing breakdown-voltage

In order to improve the fuel efficiency of Hybrid Vehicles (HVs), it is very important to reduce the power losses of the power devices (such as IGBTs and FWDs) which account for about 20% of the total electric power losses of an HV system. To reduce this power losses, a new carrier accumulating structure was developed for the IGBTs called the Super Body Layer (SBL) structure, which improved the trade-off between Von and switching loss by -16% compared to its previous generation. Furthermore, this improvement was possible without the fundamental drawbacks of typical carrier accumulating structures, such as decrease in breakdown-voltage, latch-up capability and negative capacitance. This new IGBT contributed to improve the fuel efficiency of the new Toyota HVs by 2.4% in the JC08 test cycle compared to its previous generation. Thus, the new SBL structure for low loss and high current tolerant IGBT made HVs more fuel efficient than before.