Method of forming a high capacitance diode and structure therefor

A high capacitance diode comprising:

• a semiconductor substrate of a first conductivity type having first and second surfaces;
• a first region of the first conductivity type adjacent the first surface of the semiconductor substrate, the first region having a first doping concentration;
• a semiconductor layer of a second conductivity type adjacent the first region and overlying the semiconductor substrate, the semiconductor layer having a second doping concentration that is less than the first doping concentration and also having a first surface that is opposite to the first region;
• a doped region on the first surface of the semiconductor layer having approximately the first doping concentration;
• and
• a plurality of semiconductor channels of the second conductivity type extending from the doped region through the semiconductor layer and into the semiconductor substrate, the plurality of semiconductor channels having approximately the first doping concentration.