IGBT with Reduced Feedback Capacitance

An IGBT comprising at least one first type transistor cell, comprising:

• a base region, a first emitter region, a body region, and a second emitter region, wherein the body region is arranged between the first emitter region and the base region, and wherein the base region is arranged between the body region and the second emitter region;
• a gate electrode adjacent the body region, and dielectrically insulated from the body region by a gate dielectric;
• and
• a base electrode adjacent the base region, and dielectrically insulated from the base region by a base electrode dielectric,
• wherein the base region has a first base region section adjoining the base electrode dielectric and a second base region section arranged between the second emitter region and the first base region section, and wherein a doping concentration of the first base region section is higher than a doping concentration of the second base region section,
• the IGBT further comprising:
• at least one second type transistor cell comprising a first base region section with a lower doping concentration than the first base region section of the first type transistor cell.

An IGBT comprising at least one first type transistor cell, comprising:

• a base region, a first emitter region, a body region, a second emitter region, and a third emitter region of a doping type complementary to a doping type of the second emitter region and electrically coupled in parallel with the second emitter region, wherein the body region is arranged between the first emitter region and the base region, and wherein the base region is arranged between the body region and the second emitter region;
• a gate electrode adjacent the body region, and dielectrically insulated from the body region by a gate dielectric;
• and
• a base electrode adjacent the base region, and dielectrically insulated from the base region by a base electrode dielectric,
• wherein the base region has a first base region section adjoining the base electrode dielectric and a second base region section arranged between the second emitter region and the first base region section, and wherein a doping concentration of the first base region section is higher than a doping concentration of the second base region section.