The study of the properties of a material such as a semiconductor has led to revolutionary discoveries. Over time, technologies appeared that made it possible to manufacture diodes, a MOSFET, a thyristor and other elements on an industrial scale. They successfully replaced vacuum tubes and made it possible to implement the most daring ideas. Semiconductor elements are used in all spheres of our life. They help us process colossal amounts of information; computers, tape recorders, televisions, etc. are produced on their basis.
Since the invention of the first transistor, and that was in 1948, a lot of time has passed. Varieties of this element appeared: a point germanium, silicon, field-effect or MOS transistor. All of them are widely used in electronic equipment. The study of the properties of semiconductors does not stop in our time.
These studies led to the emergence of such a device as the MOSFET. Its principle of operation is based on the fact that under the influence of an electric field (hence another name - field), the conductivity changessurface layer of a semiconductor located at the interface with a dielectric. It is this property that is used in electronic circuits for various purposes. The MOSFET has a structure that allows the resistance between the drain and the source to be reduced to almost zero under the influence of a control signal.
Its properties are different from the bipolar “competitor”. It is they who determine the scope of its application.
- High performance is ensured by miniaturization of the crystal itself and its unique properties. This is due to certain difficulties in industrial production. Crystals with a gate of 0.06 µm are currently being produced.
- Small transient capacitance allows these devices to work in high frequency circuits. For example, LSI with their use is successfully used in mobile communications.
- The almost zero resistance that a MOSFET has in its open state allows it to be used as electronic switches. They can be used in high frequency signal generating circuits or bypassing elements such as op amps.
- Powerful devices of this type are successfully used in power modules and can be included in induction circuits. A good example of their use would be a frequency converter.
When designing and working with such elements, it is necessary to take into account some features. MOSFETs are sensitive to reverse voltage and are easilyare out of order. Inductive circuits usually use fast Schottky diodes to smooth out the reverse voltage pulse that occurs during switching.
Prospects for the use of these devices are quite large. Improving the technology of their manufacture goes along the path of reducing the crystal (shutter scaling). Gradually, devices appear that are able to control more and more powerful electric motors.
