Insulated gate turn-off device with hole injector for faster turn off

An insulated gate turn-off (IGTO) device formed as a die comprising:

• a first semiconductor layer of a first conductivity type;
• a second semiconductor layer of a second conductivity type overlying the first semiconductor layer;
• a third semiconductor layer of the first conductivity type overlying at least a portion of the second semiconductor layer;
• an array of cells comprising a plurality of insulated gate electrodes within trenches formed at least within the third semiconductor layer;
• at least some of the cells comprising:
• a first semiconductor region of the second conductivity type within the third semiconductor layer and between adjacent gate electrodes, the first semiconductor region having a first dopant concentration, wherein there is a gap in the first semiconductor region;
• a second semiconductor region of the second conductivity type within the third semiconductor layer and between the adjacent gate electrodes, the second semiconductor region being deeper than the first semiconductor region and having a second dopant concentration less than the first dopant concentration;
• the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, the first semiconductor region, and the second semiconductor region forming vertical npn and pnp bipolar transistors, wherein biasing the gate electrodes above a threshold voltage causes the npn and pnp transistors to vertically conduct;
• a first electrode overlying and in contact with the first semiconductor region and a top surface of the gap in the first semiconductor region;
• and
• a second electrode in contact with the first semiconductor layer.