Electric field controlled diode with a current controlling surface grid

Claim 1

A three-electrode semiconductor current controlling device comprising: a semiconductor substrate of N-type conductivity, said substrate having opposed major surfaces; an anode region of P-type conductivity formed in one major surface; a plurality of gate regions of P-type conductivity formed in the other major surface, said gate regions comprising an interconnecting grid structure of P-type conductivity; a plurality of interconnecting cathode regions of N-type conductivity of higher impurity concentration than said substrate, each of said cathode regions formed in said other major surface and in the interstices defined by said interconnecting grid structure; anode, gate and cathode electrodes respectively overlying said anode, gate and cathode regions and making low ohmic contact therewith; and means for controlling the flow of electrical current between said anode and cathode electrodes, said means including the formation of depletion regions in said substrate around each gate region, the intersection of adjacent depletion regions causing the termination of current flow between said anode and cathode electrodes.