Prof. Mark Lundstrom at ECE Fall 2023 Colloquium

Essential Physics of the Modern MOSFET

Since the demonstration of the silicon MOSFET in 1959, engineers have made the channel lengths shorter and shorter, and to understand and model transistors, a deeper and deeper understanding of charge carrier transport was needed. In the 1960’s, square law MOSFETs could be treated with drift-diffusion equations. As channel lengths approached one micron in the late 1970’s, high-field velocity saturation became important, and in the 1980’s, velocity overshoot in sub-micron MOSFETs came into play. In the 1990’s, we entered the deep sub-micron era where quasi-ballistic and even ballistic transport became important, and, as channel lengths shrunk to the nanoscale in the 2000’s, quantum transport came into play. Modern nanoscale transistors operate differently than micron scale transistors. The details are complicated, but the essential physics is not. My goal in this talk is to discuss the operation of these devices in a simple but physically sound way.