High voltage dielectrically isolated dual gate solid-state switch

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body having a major surface and being separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body and having a portion which is common with the major surface, an n+ type cathode region located at the other end and having a portion which is common with the major surface, and an n+ type gate region having a portion which is common with the major surface and in one embodiment being located essentially between the anode and cathode regions and in another embodiment being located other than directly between the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. An n+ type semiconductor layer is sandwiched between the semiconductor body and the dielectric layer. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an "ON" and conducting state to an "OFF" (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.