IGBT Insulated Gate Bipolar Transistor
IGBT stands for an insulated gate bipolar transistor. It is having the advantage of both power MOSFET and BJT. In IGBT, layer P is used as a substrate. One side is deposited with a metal layer to form a collector and on another side of the P substrate, the N layer is epitaxially grown. The other layer is the same as power MOSFET. The three-terminal of IGBT are Emitter E, Gate G, and collector C.The IGBT is a four-layer N-P-N-P device with a MOS gated channel connecting two N-type regions. It is a new high conductance MOS gate-controlled power switch. In the operation of IGBT, the epitaxial region is conductivity modulated and thereby eliminating a major component of the on-resistance.
V-I Characteristics of IGBT
V-I Characteristics of IGBTIGBT maintains gate control over a wide range of anode currents and voltage. The basic structure of the IGBT is shown in the figure.
In many respects, it is similar to a power MOSFET. The main difference is the presence of P as the injecting layer. Next is the N layer. There is a P-N junction between this layer and more junctions as shown in the figure.