三五族碎能隙異質接面穿隧式場效電晶體之隨機變易特性的模擬與探討

Abstract

這篇論文藉由三維蒙地卡羅模擬比較和探討了金屬閘極功函數變異與源極隨機摻雜變動對於三五族碎能隙異質接面穿隧式場效電晶體、同質接面穿隧式場效電晶體與鰭式場效電晶體的影響。我們的研究指出在閉態時異質接面穿隧式場效電晶體因具有碎能隙結構，對功函數變異有較高的感受性，而啟動態時則是鰭式場效電晶體有較大的電流變異性。利用在源極端增加一未摻雜的區域可減輕功函數變異對異質接面穿隧式場效電晶體的影響。在源極隨機摻雜變動方面，異質接面穿隧式場效電晶體較同質接面穿隧式場效電晶體與鰭式場效電晶體有著較大的電流變異，而源極隨機摻雜變動對於異質接面穿隧式場效電晶體閉態電流的影響會隨著降低源級摻雜濃度下降而上升

This thesis compares and investigates the impacts of metal-gate work-function variation (WFV) and source random-dopant-fluctuation (source RDF) for III-V broken-gap heterojunction TFET (HTFET), homojunction TFET and FinFET devices using 3-D atomistic Monte Carlo simulation. Our study indicates that the HTFET exhibts higher susceptibility to WFV near OFF state due to its broken-gap nature. For ON current variation, both the HTFET and homojunction TFET show better immunity to WFV than the III-V FinFET. Device design using source-side underlap to mitigate the impact of WFV on HTFET is also assessed. Under source RDF, the HTFET exhibits larger current variations than the homojunction TFET and FinFET. The impact of source RDF increases with decreasing source doping for HTFET near OFF state.