- The MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor.
- It has a three terminal source, gate and drain terminals just like JFET.
MOSFET Symbol
- The gate terminal in MOSFET is insulated from the channel therefore sometimes MOSFET is also called as Insulated Gate Field Effect Transistor (IGFET).
- The MOSFET is a voltage controlled field effect transistor that is different from junction field effect transistor (JFET).
- MOSFET has a metal oxide gate electrode which is electrically insulated from the main semiconductor n-channel by a very thin layer of insulating material i.e silicon dioxide, commonly called as glass.
- MOSFET is also acts like a voltage controlled resistor where the current flowing through the main channel between the drain and source is proportional to the input voltage.
- It is a core of integrated circuit and it can be design and fabricated in a single chip because of its very small sizes.
There are two types in which a MOSFET can function,
- Depletion type MOSFET
When the gate voltage is positive with respect to source and the MOSFET operates in depletion mode is known as depletion type MOSFET.
- Enhancement type MOSFET
When the gate voltage is negative with respect to source, the depletion type MOSFET operates with an enhancement mode is known as enhancement type MOSFET.