ABSTRACT
The metal-oxide-semiconductor field-effect transistor (MOSFET) is a transistor that uses a control electrode, the gate, to capacitively modulate the conductance of a surface channel joining two end contacts, the source and the drain. The gate is separated from the semiconductor body underlying the gate by a thin gate insulator, usually silicon dioxide. The MOSFET can be understood by contrast with other field-effect devices, like the junction field-effect transistor and the metal-semiconductor field-effect transistor. The MOSFET channel is created by attraction to the gate and relies on the insulating layer between the channel and the gate to prevent leakage of minority carriers to the gate. As a result, MOSFETs can be made only in material systems that provide very good gate insulators, and the best system known is the silicon-silicon dioxide combination. The driving ability of the MOSFET is proportional to the current it can provide at a given gate bias.
