Field-Plate (FP) MOSFET structure has been studied to get higher performance characteristics. To get low drift layer resistance, reduction of the trench width is one typical method with FP-MOSFET because it enables us to design the fine cell pitch of the FP-MOSFET. The main method for reducing the trench width is to design large trench angle. However large trench angle for better characteristics causes some challenges. And process window always becomes narrow to get excellent characteristic. For quality control of trench angle, we found that the wafer warpage was related to the trench angle at two process steps. We confirmed these mechanisms by simulation and experiment. Furthermore, we examined which process step was appropriate for monitoring the trench angle by wafer warpage. Finally, we acquired four correlation data related to the wafer warpage after field plate oxidation. Subsequently, we derived the regression equation for quality control and confirmed the validity of the equation.

中文翻译：

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沟槽场板功率MOSFET中沟槽角度与晶圆翘曲的相关性及其在质量控制中的应用

已经研究了场板 (FP) MOSFET 结构以获得更高的性能特性。为了获得低漂移层电阻，减小沟槽宽度是 FP-MOSFET 的一种典型方法，因为它使我们能够设计 FP-MOSFET 的精细单元间距。减小沟槽宽度的主要方法是设计大的沟槽角度。然而，为了获得更好的特性，大的沟槽角度会带来一些挑战。并且工艺窗口总是变窄以获得优异的特性。对于沟槽角度的质量控制，我们发现晶圆翘曲与两个工艺步骤的沟槽角度有关。我们通过模拟和实验证实了这些机制。此外，我们检查了哪个工艺步骤适合通过晶片翘曲来监测沟槽角度。最后，我们获得了与场板氧化后晶圆翘曲相关的四个相关数据。随后，我们推导出了质量控制的回归方程并验证了方程的有效性。