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.

中文翻译：

---

基于有效浓度剖面概念的具有阶梯漂移区厚度的横向功率器件的分析和建模

阶梯漂移区厚度技术改变了漂移区掺杂剂量及其分布，因此调节了器件的关态特性。然而，由于二维阶梯漂移区的复杂结构，传统的二维建模方法过于复杂，无法提供清晰的物理意义。在本文中，基于有效浓度分布 (ECP) 理论，提出了一个简单但准确的一维 ECP 概念，以揭示阶梯漂移区技术的物理洞察力，并定量分析其对器件击穿特性的影响。因此，通过具有分段掺杂 PN 结的简单一维模型探索受 RESURF 和曲率效应影响的复杂二维结构。此外，基于所提出的分析模型，提出了设计准则，这为利用阶梯漂移区厚度技术的优势提供了有用的指导，从而实现了优化的表面电场和击穿电压。与 TCAD 仿真结果相比，发现由所提出的模型获得的结果足够准确。