在這篇論文中，我們利用圓柱座標轉換，將原本使用的矩形網格轉換成梯形網格，由於使用梯形網格分析圓弧接面相較於使用矩形網格來的精準迅速，所以我們採用梯形網格為基礎，進行pn二極體的模擬。接著，使用梯形網格模擬一般接面二極體，並且找出與使用矩形網格模擬得到的特性符合的條件。然後使用這個梯形網格去模擬gate all around MOSFET，探討半徑對於臨限電壓的影響，最後將模擬值與一般矩形理論公式的臨限電壓做個比較。 In this thesis, we use the trapezoidal elements in cylindrical coordinate system because the trapezoidal elements is fast and symmetric. We use the trapezoidal elements to analyze and simulate the circular pn junction. First, we simulate the circular pn junction by trapezoidal elements, and find out the conditions to make the trapezoidal elements have the capability to obtain the same result with the rectangular elements. Then, we simulate the gate all around MOSFET by trapezoidal elements to discuss the relation between the radius and the threshold voltage. Finally, we compare the simulated value and the rectangular formula of threshold voltage.
