Field Effect Transistor

A three-terminal transistor device where the output current flowing between the source and drain terminals is controlled by a variable electric field applied to the gate terminal. The gate design determines the type of FET: either JFET (junction FET) or MOSFET (metal-oxide semiconductor FET).

Each type has two polarities:

P - JFET positive, or p-channel devices

N - JFET negative, or n-channel devices.

In a JFET device the gate forms a true semiconductor junction with the channel.

IGFET

Any field-effect transistor that has an insulated gate.

Induced Channel MOSFET

A MOSFET in which there is no actual channel between the source and the drain. This MOSFET is constructed by making the channel of the same type of material as the substrate.

MOSFET Metal-Oxide-Silicon-Field-Effect-Transistor

In a MOSFET device the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass (silicon dioxide) and the gate is either metal or doped silicon (polysilicon), hence the acronym metal-oxide semiconductor.

N - MOSFET

P - MOSFET

See also: Dual Gate Mosfet, Junction Transistor, NPN Transistor, PNP Transistor, Transistor.