IGBT construction

Before knowing about the construction of IGBT one question you should be clear about is  What is full form of IGBT?

IGBT Structure :

Illustrates the basic structure of an IGBT.  IGBT is constructed virtually in the same way as a power MOSFET construct. There a major difference in the substrate. The n+ layer subtract at the drain in a MOSFET is now substituted in the IGBT by a p+ layer substrate called collector C. Like a power  MOSFET, an IGBT has also thousands of structure cells connected appropriately on a single chip of silicon.
                      

In the IGBT p+ substratum injects holes into n-layer so called as injection layer. The n-layer is called the region of drift. As in other semiconductor devices, the n-layer thickness determines IGBT's capacity to block voltage. Layer p is called the IGBT body region. the n- layer between p+ and p regions accommodates the pn- junction of the depletion layer, Example- junction J2.