Effective Mass Engineering in Ultra-Scaled GAAFETs

This work analyzes and optimizes the performance of ultra-scaled gate-all-around field-effect transistors (GAAFETs) from the perspective of effective mass. To comprehensively understand the impact of effective mass, three types are identified: density-of-states effective mass, confinement effective mass, and transport effective mass. We introduce crystal orientation, strain/stress, and material engineering to modify the effective mass in ultra-scaled GAAFETs. The enhancements and limitations induced by these techniques are simulated and interpreted based on the effective mass theory, providing fundamental physical insights into device behavior.