US Patent 11990466 High voltage electrostatic devices

The present disclosure relates to semiconductor structures and, more particularly, to improved turn-on voltage of high voltage electrostatic discharge device and methods of manufacture. The structure comprises a high voltage NPN with polysilicon material on an isolation structure located at a base region, the polysilicon material extending to at least one of a collector and emitter of a bipolar junction transistor (BJT), and the polysilicon material completely covering the base region of the BJT.