An Insulated Gate Bipolar Transistor (IGBT) with a trench filled with high permittivity dielectric was presented. The effect of high permittivity dielectric modulation was analyzed. The results showed that, compared with the field stop IGBT, the breakdown voltage of the proposed device was increased by 8%, the on-state voltage and turn-off loss were decreased by 8% and 11%, respectively. At the same on-state voltage drop, the turn-off loss of the device was reduced by 35%. Moreover, by adding another dielectric between gate and the previous HK dielectric, the performance of the proposed device could be enhanced further. Compared with the common field stop IGBT, the turn-off loss of the modified device was reduced by 57% at the same breakdown voltage and on-state voltage drop.