Analysis and Modeling of Lateral Power Devices With Stepped Drift Region Thickness via Effective Concentration Profile Concept

Stepped drift region thickness technique alters the drift region doping dose and its distribution, and therefore modulates the device's off-state characteristics. However, due to the sophisticated structure of the 2-D stepped drift region, the conventional 2-D modeling method is too complicated to provide a clear physical meaning. In this paper, based on the Effective Concentration Profile (ECP) theory, a simple but accurate 1-D ECP concept is proposed to unveil the physical insight of the stepped drift region technique and quantitatively analysis the influence of which on device breakdown characteristic. Therefore, the sophisticated 2-D structure affected by both RESURF and curvature effects is explored by a simple 1-D model with segmented-doped PN junction. Furthermore, based on the proposed analytical model, the designing criterion is proposed, which provide useful guidance for utilizing the benefit of the Stepped Drift Region Thickness technique and thus realizing the optimized surface electric field and breakdown voltage. The results obtained by the proposed model are found to be sufficiently accurate comparing with TCAD simulation results.