Vertical metal oxide silicon field effect semiconductor diodes

A method of forming a diode comprising:

• a) forming a plurality of cylindrical semiconductor pedestals on a first surface of a semiconductor body of a first conductivity type, the pedestals having a lower region of a first conductivity type extending from the semiconductor body, an upper region of a second conductivity type forming a pn junction between the upper and lower regions of the pedestals, and a region of a first conductivity type in and extending around the upper region adjacent the pn junction;
• b) forming a gate oxide and conductive gate extending from the lower region to the region of a first conductivity type in and extending around the upper region;
• c) providing a conductive layer contacting the conductive gate and the region of a first conductivity type in and extending around the upper region;
• and,
• d) providing a conductive contact to the semiconductor body.

A diode comprising:

• a semiconductor body of a first conductivity type;
• a plurality of cylindrical pedestals on a first surface of the semiconductor body, each having a lower region of the first conductivity type and an upper region of a second conductivity type forming a pn junction therebetween, the upper and lower regions defining sidewalls of each pedestal;
• a region of the first conductivity type around the upper region of each pedestal adjacent the pn junction;
• a gate oxide on the sidewalls of each pedestal extending from the lower region to the region of the first conductivity type around the upper region of each pedestal, part of the region of the first conductivity type around the upper region of each pedestal not being covered by the gate oxide;
• a conductive gate over the gate oxide;
• a layer of the second conductivity type between pedestals;
• a conductive layer over the plurality of cylindrical pedestals and making electrical contact with the conductive gate and the region of the first conductivity type around the upper region of each pedestal;
• and,
• a conductive layer making electrical contact to the semiconductor body.

A diode comprising:

• a plurality of cylindrical semiconductor pedestals on a first surface of a semiconductor body of a first conductivity type, the pedestals having a lower region of a first conductivity type extending from the semiconductor body, an upper region of a second conductivity type and forming a pn junction between the upper and lower regions of the pedestals, and a region of a first conductivity type in and extending around the upper region adjacent the pn junction;
• a gate oxide and conductive gate extending from the lower region to the region of a first conductivity type in and extending around the upper region of each pedestal;
• a conductive layer contacting the conductive gate and the region of a first conductivity type in and extending around the upper region;
• and,
• a conductive contact to the semiconductor body.