Patent ID: 9412854
Filing Date: 2016-08-09
CPC Classification: H01L

Claim Text:
1. An IGBT module, comprising: a first IGBT comprising a first semiconductor substrate, a collector electrode, a gate electrode, an emitter electrode, a collector-side transistor formed in the first substrate, and a collector region of a first conductivity type and of a first doping concentration and in ohmic contact with the collector electrode, the collector-side transistor having a first gain factor which corresponds to the first doping concentration; and a second IGBT comprising a second semiconductor substrate that is separate from the first semiconductor substrate, a collector electrode electrically connected to the collector electrode of the first IGBT, a gate electrode electrically connected to the gate electrode of the first IGBT, an emitter electrode electrically connected to the emitter electrode of the first IGBT a collector-side transistor formed in the second substrate, and a collector region of the first conductivity type and of a second doping concentration different than the first doping concentration and in ohmic contact with the collector electrode of the first IGBT, the collector-side transistor of the second IGBT having a second gain factor which corresponds to the second doping concentration and is different than the first gain factor, wherein the first and second doping concentrations differ by at least 20% so that the first and second gain factors differ by more than expected from manufacturing variations and variations due to aging processes.