Advanced wide cell pitch CSTBTs having light punch-through (LPT) structures

Abstract

In order to improve the total performance of nonpunch-through (NPT) type trench IGBT for the 1200/spl sim/1700 V region, a triple combination of concepts is adopted: "wide cell pitch" and "carrier stored trench-gate bipolar transistor (CSTBT)" for the emitter side, and "light punch-through (LPT)" structure for the collector side. The wide cell pitch LPT-CSTBT demonstrates lower on-state voltage, lower switching loss, lower junction leakage current than that of conventional NPT trench IGBT, and relatively large short circuit capability. In addition, our device shows excellent gate dielectric reliability by utilizing CVD gate oxide film. The LPT-CSTBT with CVD gate dielectric is a promising candidate for high voltage power devices, because its performance is approaches that of punch-through (PT) trench IGBTs.