The Role of Even Longitudinal Electric Field Distribution in Optimizing Carrier Transport Efficiency of Field-Effect Transistors

Abstract

Longitudinal electric field ( E L ) optimization is a widely applied approach to improve the carrier transport efficiency of semiconductor devices such as field-effect transistors (FETs). However, rigorous analysis to determine the optimal E L distribution remains a major challenge. By developing a physical model and investigating the impact of the E L distribution on the carrier transport efficiency, this work proves that an even E L distribution is the optimal case. To verify the model, FETs with various gate structures are designed and studied. The results show that the current driving capability of FETs can be improved by achieving a more uniform E L distribution along the channel direction. In addition, the use of multi-material gate architecture can produce a quasi-even E L distribution and thus performs the greatest current performance. Besides, various FET structures that feature the even E L distribution are discussed as well. More importantly, our results show that the constant- E L scaling can be implemented via the even E L , which exhibits potential in relieving the threshold voltage shift and achieving the maximum current performance.

Keywords: Carrier transport, transport efficiency, longitudinal electric field, current performance, field-effect transistor