矽及鍺通道P型金氧半電晶體二維量子井模擬

Abstract

目前，利用由製程所造成的單軸應力(uniaxial stress)來改善元件效能已經被廣泛地使用，例如矽鍺源汲極、接觸孔蝕刻停止層。而採用高載子遷移率的鍺通道或應變鍺通道，對於未來CMOS微縮是必要的。所以研究因形變而改變的載子傳導帶或價電帶結構是個重要的議題。 在本篇論文中，吾人利用Luttenger-Kohn模型計算價電帶結構，自洽計算薛丁格及泊松方程式，其中包含矽及鍺通道金氧半電晶體二維量子井。最後，吾人利用蒙地卡羅(Monte Carlo)方法來模擬量子井中電洞的傳輸。

For today’s technology, uniaxial–process induced stress is used to improve device performance. One method is the adoption of the embedded and raised SiGe in the p-channel source and drain and a tensile capping layer on the n-channel device. The other method is with advantages of dual stress liners: compressive and tensile silicon nitride (SiN) for p- and n-channel devices, respectively. However, for further CMOS scaling, it is imperative to investigate other high mobility channel materials, such as Ge, strained Si/Ge and GaAs. Due to the complexity of the coupling valence band among the heavy, light and split-off bands, the treatment of one mass approximation applied to hole quantization in semiconductor inversion layer is incorrect. This thesis focuses on valence band calculations in various devices, such as Si MOS structure and double gate devices by iteratively solving the coupled Schrödinger and Poisson equations with six-band Luttinger-Kohn model. Finally, we developed a two-dimensional Monte Carlo simulation to study hole transport properties in SiGe and Ge quantum wells.