Effective Concentration Profile: Mechanism of Gate Field-Plate Assistant Effect in SOI Lateral Power Devices

Abstract

The field-plate (FP) technique suppresses the electric field crowding at the p-n junction by inducing the interface charges in the drift region. However, due to the modeling difficulty, the physical meaning cannot be elaborated via the conventional 2-D methods, not to mention the designing optimization. Therefore, the FP assistant reduced surface field effective concentration profile (ECP) is proposed in this paper to explore the physical insight of the FP assistant 2-D coupling. The ECP simplifies the sophisticated 2-D coupling by equating the FP assistant effect to the variation of the ECP. As a result, a simple and effective 1-D analytical model is presented to qualitatively and quantitatively explore the FP-induced surface field reshaping and its distinctive breakdown mechanism. The analytical solutions are found out to be consistent with the simulation results obtained from MEDICI, a commercial TCAD tool.