本篇論文中,我們藉由加入離子碰撞游離模型於二維元件模型內,來模擬半導體元件內部載子發生雪崩崩潰之現象。首先,我們探討兩種不同結構,第一種為簡單的 pn 接面二極體,藉此元件來探討不同濃度下載子的傳輸現象,並且進行一系列的 pn 二極體模擬。另一種為中間夾一層未摻雜的本質半導體之 pin 二極體,利用此結構來萃取矽材料在高電場下的電子和電洞的碰撞游離係數,和原始設定值作比較後再加分析並找出造成兩者數據差異的原因,最後再利用先前萃取出之電子碰撞游離係數使用兩組模型相互對照的方法來萃取電洞碰撞游離係數。 In this thesis, we design a 2-D device simulator which includes the impact ionization model to simulate the avalanche breakdown. At first, we discuss two device structures. One is simple p-n junction diode. We use it to discuss the transmission of carriers for different doping concentration, and to proceed a series of simulation for p-n junction diodes. Another is p-i-n diode with an undoped intrinsic semiconductor layer in the middle, and we use this structure to extract the electron and hole impact-ionization rate for Si in high electric field. Then we compare it with the original theoretical value to analyze and find out the reasons which make different results. Finally, we extract the hole impact ionization rate based on the electron impact ionization rate obtained in the previous simulation.