A novel high-voltage trench gate insulated gate bipolar transistor with diffusion remnant (DR) layer (DR-IGBT) is proposed in this letter. The DR layer in the emitter side which is formed by grinding after ultra-deep N+ diffusion helps to stored the carrier and improves the on-state voltage drop (Vce(SAT)). The DR-IGBT has a better trade-off between the breakdown voltage (BV) and Vce(SAT) than the carrier stored trench bipolar transistor (CSTBT). The doping profile of diffusion remnant layer makes the junction of the p-base/DR layer nearly linearly graded junction, which does not decline the BV too much. The depth of the diffusion remnant layer and N+ diffusion layer less impacts BV and Vce(SAT) unless the diffusion depth is reduced.
