Structure and method for RESURF LDMOSFET with a current diverter

摘要

Methods and apparatus are provided for reducing substrate leakage current of RESURF LDMOSFET devices. A semiconductor device comprises a semiconductor substrate (22) of a first type; first and second terminals (39,63) laterally spaced-apart on a surface (35) above the substrate; a first semiconductor region (32) of the first type overlying the substrate and ohmically coupled to the first terminal (39); a second semiconductor region (48) of a second opposite type in proximity to the first region and ohmically coupled to the first terminal; a third semiconductor region (30) of the second type overlying the substrate and ohmically coupled to the second terminal (63) and laterally arranged with respect to the first region; a parasitic vertical device comprising the first region and the substrate, the parasitic vertical device for permitting leakage current to flow from the first terminal to the substrate; a fourth semiconductor region (62) of the first type in proximity to the third region and ohmically coupled to the second terminal, thereby forming in combination with the third region a shorted base-collector region of a lateral transistor extending between the first and second terminals to provide diode action; a channel region (27) of the first type separating the first and third regions at the surface; a gate insulator (43) overlying the channel region; and a gate electrode (42) overlying the gate insulator.