What is a MOS Capacitor?MOS Capacitor DefinedMOS stands for Metal Oxide Semiconductor. An MOS capacitor comprises a semiconductor body or substrate, an insulator, and a metal gate. Typically, the gate is made from heavily doped n+ poly-silicon that functions like metal. Silicon dioxide (SiO2) serves as the dielectric material between the capacitor plates, where the metal and semiconductor layers act as the two plates. The capacitance of an MOS capacitor varies with the voltage applied to its gat