Insulated gate bipolar transistor having a specific buffer layer resistance

摘要

An n+ buffer layer, that is located between an n- base layer and a p+ substrate, has a resistivity in the range of 0.005-0.03 OMEGA cm and a thickness not more than 10 mu m. Further, the base layer has an impurity concentration not more than (0.3xI1)/(Sx1.6x10-19x6.0x106), where I1 is a rated current in ampere and S is an effective are in cm2.