Quantum-mechanical study on the electron effective mobility of surrounding-gate nMOSFETs

As metal - oxide - semiconductor field-effect transistors (MOSFETs) down scaling progresses into the nanometer regime, quantum mechanical effects are becoming more and more significant. In this work, a model for the surrounding-gate (SG) nMOSFET is developed. The Schrödinger equation is solved analytically and some of the results are verified via simulations. We find that the percentage of the electrons with a lighter conductivity mass increases as the temperature decreases, or as the gate voltage reduces. These imply that low temperature and low gate voltage will enhance the electron effective mobility, which is good for the device performance.