Insulated gate bipolar transistor (IGBT)

The IGBT stands from Insulated gate bipolar transistor. It is a three terminal semiconductor device is named as gate, emitter and collector.

The terminals of the IGBT are associated with a conductance path and gate terminal is associated with its control.

When the gate terminal is positive with respect to emitter and with gate- emitter voltage more than the threshold voltage of IGBT, an n-channel is formed in the p-regions as in a power MOSFET (metal oxide semiconductor field effect transistor).

This n-channel short circuits the n^– region with n⁺ emitter regions. An electron movement in the n-channel, in turn causes substantial hole inject from p⁺ substrate layer into the epitaxial n^– layer. Ultimately a forward current is established show in fig.