Study on the IGBT Using a Deep Trench Filled With SiO2 and High-k Dielectric Film

A novel insulated gate bipolar transistor (IGBT) using a deep trench filled with SiO2 and high-k dielectric film (HKF) is presented. The deep trench with the HKF can provide rapid depletion of the drift region during the turn-off transient, eliminating the tail current and reducing the turn-off loss. According to the simulation results, with a relative permittivity of 475 and a 400 nm thickness for the HKF, the proposed device obtains a 62% reduction in the turn-off loss compared to a conventional field stop IGBT at the same on-state voltage and breakdown voltage. Moreover, compared to an IGBT using a trench filled with HK dielectric, the proposed device is more feasible to be fabricated and has a lower gate-to-anode capacitance, which can reduce the current and voltage oscillations during the turn-off transient.