It can be inverted from p-type to n-type by applying positive or negative gate voltages. The semiconductor surface at the below oxide layer is located between the source and drain terminals. The MOS capacitor is the main part of MOSFET. The working of a MOSFET depends upon the MOS capacitor. Another synonym is IGFET for the insulated-gate field-effect transistor. A metal-insulator-semiconductor field-effect transistor or MISFET is a term almost synonymous with MOSFET. It is insulated from the channel near an extremely thin layer of metal oxide. The width of the channel is controlled by the voltage on an electrode is called gate which is located between source and drain. The charge carriers enter the channel at source and exit via the drain. It works by varying the width of a channel along which charge carriers flow (electrons or holes). The body is frequently connected to the source terminal, reducing the terminals to three. It is a four-terminal device with source (S), drain (D) and gate Terminal (G) and body (B) terminals. The enhancement-mode MOSFET is equivalent to a “Normally Open” switch. Enhancement Type: The transistor requires a Gate-Source voltage(VGS) to switch the device “ON”.The depletion-mode MOSFET is equivalent to a “Normally Closed” switch. Depletion Type: The transistor requires the Gate-Source voltage (VGS) to switch the device “OFF”.The various types of MOSFET are given below: The main advantage is that it requires almost no input current to control the load current, when compared with bipolar transistors. MOSFETs are particularly useful in amplifiers due to their input impedance being nearly infinite which allows the amplifier to capture almost all the incoming signal. Since they can be made with either p-type or n-type semiconductors, complementary pairs of MOS transistors can be used to make switching circuits with very low power consumption, in the form of CMOS logic.

MOSFET structureĪ MOSFET is by far the most common transistor in digital circuits, as hundreds of thousands or millions of them may be included in a memory chip or microprocessor.

It is used to provide isolation by prevent the direct flow of charges on gate to the conducting channel. The silicon dioxide forms the gate of the mosfet. MOSFETs are now even more common than BJTs (bipolar junction transistors) in digital and analog circuits. The ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. It is used for switching or amplifying signals. A metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a field-effect transistor (FET with an insulated gate) where the voltage determines the conductivity of the device.

Fet electronics