ABSTRACT
Semiconductor is a class of materials that can generally be defined as having an electrical resistivity in the range of 10−2-109 -cm.1 Addition of a very small amount of impure atoms can make a large change in the conductivity of the semiconductor material. This unique materials property makes all semiconductor devices and circuits possible. The amount of free charge in the semiconductor and the transport characteristics of the charge within the crystalline lattice determine the conductivity. Device operation is governed by the ability to generate, move, and remove free charge in a controlled manner. Material characteristics vary widely in various semiconductors and only certain materials are suitable for use in the fabrication of microwave and RF devices.
