全包覆式閘極三五族穿隧式電晶體的直徑最佳化及短通道效應之理論探討

Abstract

這篇論文藉由電腦數值模擬探討直徑對於三五族全包覆式閘極三五族穿隧式電晶體的影響。結果顯示會有最佳的直徑因為閘極控制跟量子侷限效應的互相抗衡。另外我們提出同質接面的穿隧式電晶體的模型計算跟與電腦數值模擬的互相驗證。源極跟汲極的空乏區對於穿隧式電晶體的模型計算十分重要。經由模型計算的直徑影響有著跟經由電腦數值模擬的直徑影響一樣的趨勢。最後，我們比較了穿隧式電晶體跟金氧半場效電晶體的短通道效應，並且有考慮金氧半場效電晶體的源極到汲極的穿隧電流。結果顯示金氧半場效電晶體的可伸縮性比穿隧式電晶體還要差因為隨著閘極縮短時的穿隧障礙的縮小及穿隧長度的縮小。

This thesis investigates the diameter dependence for III-V gate-all-around homojunction and heterojunction TFET using TCAD numerical simulation. The optimized diameter has been shown due to the counterbalance of the gate control and the quantum confinement effect. In addition, model calculation for the homojunction TFET is proposed and verified with TCAD numerical simulation. Source and drain depletion is very important in modeling of TFET. The diameter dependence by model calculation also shows the same trend with TCAD numerical simulation. Finally, the short channel effect of TFET has been compared with MOSFET with considering the source-to-drain tunneling current for MOSFET. Our results indicate the scalability of MOSFET is worse than TFET due to the lowering of the tunneling barrier and the tunneling length with decreasing the gate length.