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 surface channel is formed at the interface between the semiconductor body and the gate insulator, see Fig. 4.1. A high-performance <italic>n</italic>-channel MOSFET. The device is isolated from its neighbors by a surrounding thick <italic>field oxide</italic> under which is a heavily doped <italic>channel stop</italic> implant intended to suppress accidental channel formation that could couple the device to its neighbors. The drain contacts are placed over the field oxide to reduce the capacitance to the body, a parasitic that slows response times. These structural details are described later. https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781315220482/58874d52-9fb3-42c4-9c16-306fdd7077ec/content/fig4_1.tif"/> (Source: After Brews, J.R. 1990. The submicron MOSFET. In High-Speed Semiconductor Devices, ed. S.M. Sze, pp. 139–210. Wiley, New York.)