Quddus Mohammed Tanvir, Latorre-Rey Alvaro D, Ramezani Zeinab, Mudholkar Mihir
Power Solutions Group, Onsemi, Scottsdale, AZ 85250, USA.
Micromachines (Basel). 2025 Jan 14;16(1):90. doi: 10.3390/mi16010090.
Trench MOS Barrier Schottky (TMBS) rectifiers offer superior static and dynamic electrical characteristics when compared with planar Schottky rectifiers for a given active die size. The unique structure of TMBS devices allows for efficient manipulation of the electric field, enabling higher doping concentrations in the drift region and thus achieving a lower forward voltage drop (VF) and reduced leakage current (IR) while maintaining high breakdown voltage (BV). While the use of trenches to push electric fields away from the mesa surface is a widely employed concept for vertical power devices, a significant gap exists in the analytical modeling of this effect, with most prior studies relying heavily on computationally intensive numerical simulations. This paper introduces a new physics-based analytical model to elucidate the behavior of electric field and potential in the mesa region of a TMBS rectifier in reverse bias. Our model leverages the concept of shared charge between the Schottky and MOS junctions, capturing how electric field distribution is altered in response to trench geometry and bias conditions. This shared charge approach not only simplifies the analysis of electric field distribution but also reveals key design parameters, such as trench depth, oxide thickness, and doping concentration, that influence device performance. This model employs the concept of shared charge between the vertical Schottky and MOS junction. Additionally, it provides a detailed view of the electric field suppression mechanism in the TMBS device, highlighting the significant effects of the inversion charge on the MOS interface. By comparing our analytical results with TCAD simulations, we demonstrate strong agreement, underscoring the model's accuracy and its potential to serve as a more accessible alternative to resource-intensive simulations. This work contributes to a valuable tool for TMBS device design, offering insights into electric field management that support high-efficiency, high-voltage applications, including power supplies, automotive electronics, and renewable energy systems.
对于给定的有源芯片尺寸，与平面肖特基整流器相比，沟槽型金属氧化物半导体势垒肖特基（TMBS）整流器具有卓越的静态和动态电学特性。TMBS器件的独特结构允许对电场进行有效调控，使得漂移区能够采用更高的掺杂浓度，从而在保持高击穿电压（BV）的同时实现更低的正向压降（VF）并降低漏电流（IR）。虽然利用沟槽将电场从台面表面推开是垂直功率器件中广泛采用的概念，但在这种效应的分析建模方面存在显著差距，大多数先前的研究严重依赖计算密集型的数值模拟。本文引入了一种基于新物理原理的分析模型，以阐明TMBS整流器在反向偏置时台面区域的电场和电势行为。我们的模型利用了肖特基结和MOS结之间共享电荷的概念，捕捉了电场分布如何响应沟槽几何形状和偏置条件而变化。这种共享电荷方法不仅简化了电场分布分析，还揭示了影响器件性能的关键设计参数，如沟槽深度、氧化物厚度和掺杂浓度。该模型采用了垂直肖特基结和MOS结之间共享电荷的概念。此外，它详细展示了TMBS器件中的电场抑制机制，突出了反型电荷对MOS界面的显著影响。通过将我们的分析结果与TCAD模拟进行比较，我们证明了两者高度吻合，强调了该模型的准确性及其作为资源密集型模拟的更易获取替代方案的潜力。这项工作为TMBS器件设计提供了一个有价值的工具，深入了解电场管理，支持包括电源、汽车电子和可再生能源系统在内的高效、高压应用。
