在這篇文章中，我們利用圓柱座標轉換將正方形替換為梯形網格。由於使用圓柱座標相較於直角座標分析圓弧接面來的精準迅速，所以我們採用圓柱座標下的梯形網格當做探討依據，並且進行一系列的PN二極體模擬。首先，我們使用梯形網格分析PN二極體順偏與逆偏特性。確定無誤後，接著我們繼續探討不同擴散半徑對於崩潰電壓的影響。最後，我們比較了直角座標與圓柱座標的計算量與精確度，也證實圓柱下的梯形網格對於圓弧接面有較高的對稱性，因此所得到的數值解較為精準且快速。

In this paper, we use the cylindrical coordinates to substitute Cartesian coordinates. Because of the symmetry and certainty we use the cylindrical coordinates to analyze and simulate the curved PN junction. First, we analyze and simulate the forward I-V curve and reverse I-V curve based on the trapezoid cell. Second, we discuss the breakdown voltage in reversed bias with different diffusion radius. Finally, comparisons between two coordinates show that the cylindrical coordinates is better because of its symmetry in the curved PN junction.

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