Solid State Electronic Devices, 7th Edition

6.4 The Metal–​Insulator–​Semiconductor Fet

One of the most widely used electronic devices, particularly in digital integrated circuits, is the metal–​insulator–​semiconductor (MIS) transistor. In this device the channel current is controlled by a voltage applied at a gate electrode that is isolated from the channel by an insulator. The resulting device may be referred to generically as an insulated-gate field-effect transistor (IGFET). However, since most such devices are made using silicon for the semiconductor, SiO₂ or other oxides for the insulator, and metal or heavily doped polysilicon for the gate electrode, the term MOS field-effect transistor (MOSFET) is commonly used.

6.4.1 Basic Operation and Fabrication

The basic MOS transistor is illustrated ...