Models of second-order effects in metal-oxide-semiconductor field-effect transistors for computer applications

Abstract

Second-order effects in metal-oxide-semiconductor field-effect transistors (MOSFETs) are important for devices with dimensions of 2 μm or less. The short and narrow channel effects and drain-induced barrier lowering primarily affect threshold voltage, but formulas for drain current must also take these effects into account. In addition, the drain current is sensitive to channel length modulation due to pinch-off or velocity saturation and is diminished by electron mobility degradation due to normal and lateral electric fields in the channel. A model of a MOSFET including these considerations and emphasizing charge conservation is discussed.