Improving dynamic characteristics for IGBTs by using interleaved trench gate

A novel trench insulated gate bipolar transistor (IGBT) with improved dynamic characteristics is proposed and investigated. The poly gate and poly emitter of the proposed IGBT are arranged alternately along the trench. A self-biased p-MOSFET is formed on the emitter side. Owing to this unique three-dimensional (3D) trench architecture, both the turn-off characteristic and the turn-on characteristic can be greatly improved. At the turn-off moment, the maximum electric field and impact ionization rate of the proposed IGBT decrease and the dynamic avalanche (DA) is suppressed. Comparing with the carrier-stored trench gate bipolar transistor (CSTBT), the turn-off loss ( E off ) of the proposed IGBT also decreases by 31% at the same ON-state voltage. At the turn-on moment, the built-in p-MOSFET reduces the reverse displacement current ( I G_dis ), which is conducive to lowing d I C /d t . As a result, compared with the CSTBT with the same turn-on loss ( E on ), at I C = 20 A/cm 2 , the proposed IGBT decreases by 35% of collector surge current ( I surge ) and 52% of d I C /d t .