Analysis of a Thin P-type Buried Layer IGBT with High Breakdown Voltage and Low Switching Loss

To reduce the switching loss and improve the breakdown voltage of IGBTs, a novel IGBT structure with an internal thin p-type buried layer (TBP-IGBT) is proposed. A very thin P-buried layer is inserted into the N-drift region of a conventional carrier-stored trench IGBT (con-CSTBT), forming a secondary PN junction and activating an internal thyristor. TCAD simulation results show that the proposed TBP-IGBT exhibits a similar on-state voltage drop (Von) as the conventional device, while the breakdown voltage is significantly improved (by about 24%). More importantly, the switching energy loss is greatly reduced: under the same Von condition, the turn-on energy loss (Eon) decreases from 29.93 mJ to 3.52 mJ (a reduction of approximately 88.2%), and the turn-off energy loss (Eoff) decreases from 12.09 mJ to 9.99 mJ (a reduction of about 17.4%). The total switching energy (ESW) is reduced from 42.02 mJ to 13.51 mJ (a reduction of around 67.8%).