What is IGBT(Insulated gate bipolar transistor)?

Insulated gate bipolar transistor or IGBT, is a solid state devices primarily used as an electronic switch which, as it was developed, came to combine high efficiency and fast switching. IGBT is a switch that is used in order to allow power flow in the ON state and to stop power flow when it is in the OFF state. It is applying voltage on semiconductor component, for this reason changing its properties to create or block an electrical path.

Construction of IGBT

The insulated gate bipolar transistor (IGBT) is a three terminal semiconductor device combines the benefits of both MOSFET and BJT. So, an insulated gate bipolar transistor (IGBT) has input impedance like that of a MOSFET and low ON state power loss as in a BJT. It is also called as metal oxide semiconductor insulated gate transistor (MOSIGT) and other name to this device are insulated gate transistor (IGT), conductivity modulated field effect transistor (COMFET).its constructed is similarly to a n-channel vertical construction power MOSFET except the n⁺ drain is replaced with a p⁺ collector layer, thus forming a vertical PNP bipolar junction transistor. This addition p⁺ region creates a cascade connection of a PNP bipolar junction transistor with the surface n channel MOSFET.

Construction of IGBT