量子電容對於三五族多閘極金氧半場效電晶體本質反轉層電容之影響

Abstract

由於三五族材料擁有非常高的電子遷移率，三五族材料常被視為是非常有希望可以取代矽材料的通道材料。在本篇論文中，藉由數值模擬以及理論計算的結果，我們將探討量子電容對於三五族雙閘極與多閘極金氧半場效電晶體之本質反轉層電容的影響。我們的研究指出，不論是在雙閘極或多閘極的三五族元件中，量子電容皆會顯著地影響反轉層電容的特性，並且會明顯地使反轉層電容值下降。由於元件的驅動電流和元件的反轉層電容值呈正相關，我們會將三五族元件的反轉層電容與矽通道元件的反轉層電容做比較。此外，多閘極三五族元件會因為量子電容而有額外的反轉層電荷量下降，因此我們將探討對應ITRS 2018到2024年之多閘極三五族元件所需要補償反轉層電荷量下降之最低載子遷移率增益。

III-V channel materials are promising alternatives to Si because of their higher carrier mobility for n-MOSFETs. This thesis investigates the impact of quantum capacitance on the intrinsic inversion capacitance of III-V double-gate and tri-gate n-MOSFETs by using TCAD quantum-mechanical numerical simulation corroborated by theoretical calculation. Our study points out that quantum capacitance will significantly impact the characteristics of inversion capacitance and lead to an apparent inversion capacitance degradation in both double-gate and tri-gate III-V devices. Since the inversion capacitance degradation will cause drive-current loss, the inversion capacitance characteristics of III-V devices are benchmarked with Si counterparts, and the needed mobility gain of the III-V devices following the ITRS 2018 to 2024 technology nodes will be pointed out to compensate the inversion charge loss due to quantum capacitance.