A semiconductor device is formed as follows. A semiconductor substrate having a first region of a first conductivity type is provided. A region of a second conductivity type is formed in the semiconductor substrate such that the first and second regions form a p-n junction. First and second charge control electrodes are formed adjacent to but insulated from one of the first and second regions, along a dimension parallel to flow of current through the semiconductor device, wherein the first charge control electrode is adapted to be biased differently than the second charge control electrode.