Basics and the Ideal MOS Transistor

The MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a field-effect transistor (referring to an electric field) that takes advantage of the semiconductor properties of silicon. The voltage applied to the MOS gate produces an electric field that modulates the resistivity of the semiconductor. It is the basic building block of digital integrated circuits manufactured using CMOS technology, and its function is analogous to that of a voltage-controlled switch. CMOS technology allows for the fabrication of circuits containing both N-type (nMOS) and P-type (pMOS) MOS transistors. It is said that nMOS and pMOS can be co-integrated, hence the name CMOS for Complementary MOSFET. If only a single type of transistor can be manufactured, the technology is referred to as unipolar.