Patent ID: 7235862

Claim:
A structure comprising: a varactor which comprises: (a) a plate region and a body region of a semiconductor body, the body region being of a first conductivity type, the plate region being of a second conductivity type opposite to the first conductivity type, the plate and body regions meeting each other to form a p-n junction and extending to a primary surface of the semiconductor body; (b) a plate electrode and a body electrode respectively connected to the plate and body regions, the plate electrode being at a plate-to-body bias voltage relative to the body electrode; (c) a dielectric layer situated over the semiconductor body and contacting the body region; and (d) a gate electrode situated over the dielectric layer at least where the dielectric layer contacts material of the body region, the gate electrode being at a gate-to-body bias voltage relative to the body electrode, the gate-to-body voltage being maintained approximately constant at a non-zero value as the plate-to-body voltage is varied; and a field insulating region extending into the semiconductor body along the primary surface to define a semiconductor island laterally surrounded by the field insulating region and substantially fully occupied by material of the plate and body regions.