Insulated gate turn-off device with turn-off schottky-barrier mosfet

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 not extending through the third semiconductor layer;
• at least some of the cells comprising:
• a first semiconductor region of the second conductivity type overlying the third semiconductor layer and adjacent to an insulated gate electrode;
• a second semiconductor region of the second conductivity type overlying at least part of the first semiconductor region and being more highly doped than the first semiconductor region;
• and
• a Schottky conductor overlying and contacting at least a top surface of the first semiconductor region adjacent to the insulated gate electrode,
• wherein the Schottky conductor, the first semiconductor region, and the third semiconductor layer form a MOSFET, wherein a voltage applied to the insulated gate electrode greater than a threshold voltage of the MOSFET inverts the first semiconductor region adjacent to the insulated gate electrode to form a lower resistance path between the Schottky conductor and the third semiconductor layer to reduce a beta of a bipolar transistor formed by the first semiconductor region, the third semiconductor layer, and the second semiconductor layer to turn off the IGTO device.