An Improvement of the Breakdown Voltage Characteristics of NPT-TIGBT by Using a P-Buried Layer

Abstract

In this paper, we introduced a P-buried (Pb) layer under trench gate which relieved the electric field crowding in the Non Punch Through Trench gate Insulated Gate Bipolar Transistor (NPT-TIGBT) structure. The Pblayer, with carrier concentration of 5x1016cm-3, was created underneath the trench gate within the n-drift layer. In this way, the concentration of electric field at the trench bottom corner decreased. As a result, the breakdown voltage characteristics of NPT-TIGBT improved. The structures were proposed and verified by T-CAD Sentuarus simulation. From the simulation results, the breakdown voltage increased by approximately 30% compared with conventional NPT-TIGBT.