ABSTRACT
A metal-oxide-semiconductor field-effect transistor (MOSFET), as the name field effect transistor implies, is a voltage-controlled device. While the bipolar junction transistor was the first transistor device to take hold in the integrated circuit world, there is no question that the advent of MOSFETs, is what truly revolutionized the world in the so-called information age. A MOSFET type has emerged in the drive to improve the properties of the basic building block. This MOSFET is built on top of a buried oxide layer followed by a thin epitaxial layer into which the active devices are fabricated. The frequency response of the MOSFET is determined largely from the device capacitances. There are device capacitances associated with the gate structure and the body diode structure. Thus, devices that are normally off, that is, have no conducting channel at zero gate-source bias, are referred to enhancement mode devices because the channel must be enhanced before it will conduct.
