What is a MIS transistor?

Element base of semiconductor elements is constantly growing. Each new invention in this field, in fact, changes the whole concept of electronic systems. Schematic capabilities change in the design, new devices appear on their basis. Since the invention of the first transistor (1948), it's been a long time. The structures "pnp" and "npn", bipolar transistors were invented . Over time, a MOS-transistor appeared, working on the principle of changing the electrical conductivity of a near-surface semiconductor layer under the influence of an electric field. Hence another name for this element is the field one.

The abbreviation MDP (metal-dielectric-semiconductor) characterizes the internal structure of this device. Indeed, the shutter is isolated from the drain and source by a thin non-conductive layer. The modern MIS-transistor has a gate length equal to 0.6 μm. Only an electromagnetic field can pass through it-that's what affects the electrical state of the semiconductor.

Let's look at how a field-effect transistor works , and find out what its main difference is from a bipolar "colleague". When there is a necessary potential, an electromagnetic field appears on its gate. It affects the resistance of the drain-source transition transition. Here are some advantages of using this device.

• In the open state, the drain-source transient resistance is very small, and the MIS transistor is successfully used as an electronic key. For example, it can control an operational amplifier by shunting the load or participating in the operation of logic circuits.
• Also note the high input resistance of the device. This parameter is quite relevant when working in low-current circuits.
• A low drain-source capacitance allows using a MIS transistor in high-frequency devices. In the process, there is no distortion in the transmission of the signal.
• The development of new technologies in the production of elements led to the creation of IGBT-transistors, combining the positive qualities of field and bipolar elements. Power modules on their base are widely used in soft starters and frequency converters.

When designing and working with these elements, it is necessary to take into account that MIS transistors are very sensitive to overvoltage in the circuit and static electricity. That is, the device can be damaged by touching the control terminals. Use special grounding when installing or dismantling.

Prospects for using this device are very good. Due to its unique properties, it has found wide application in various electronic equipment. The innovative direction in modern electronics is the use of power IGBT-modules for operation in various circuits, including induction ones.

The technology of their production is constantly being improved. Developments are underway to scale (reduce) the length of the shutter. This will improve the already good performance parameters of the device.