Device considerations and design optimizations for dopant segregated Schottky barrier MOSFETs

作者：Shih Chun Hsing^*; Yeh Sheng Pin

来源：Semiconductor Science and Technology, 2008, 23(12): 125033.

DOI：10.1088/0268-1242/23/12/125033

This work thoroughly explores the considerations and optimizations of dopant segregated Schottky barrier MOSFETs (DS-SBMOS) using two-dimensional device simulations. The dependences of the device characteristics on the dopant segregated layer are clarified in the DS-SBMOS. The heavier and wider dopant segregation layer efficiently modifies the Schottky barriers to suppress the off-state ambipolar conduction and simultaneously to enhance the on-state driving current. However, DS-SBMOS devices have slightly worse short-channel effects than conventional MOSFETs, because of additional segregation extensions into the silicon substrate. Importantly, apparent degradations of DS-SBMOS in ambipolar conduction are observed when a thinner gate-insulator or a heavier halo profile is used for the scaled short-channel DS-SBMOS. Dual workfunction gate (DWG) architecture is first proposed to optimize DS-SBMOS by tailoring Schottky barrier distributions through vertical gate engineering. An optimal design of DS-SBMOS devices can be achieved using the DWG structure with enhanced driving current, minimized ambipolar conduction and a suitable short-channel effect as the gate-insulator is scaled down.

• 出版日期2008-12
• 单位中国科学院电工研究所; 清华大学