Patent ID: 7081663

Claim:
A structure comprising: a varactor comprising (a) a plate region and a body region of a semiconductor body, (b) a plate electrode and a body electrode respectively connected to the plate and body regions, (c) a gate dielectric layer situated over the semiconductor body and contacting the body region, and (d) a gate electrode situated over the gate dielectric layer at least where the gate dielectric layer contacts material of the body region, the plate and body regions being of opposite conductivity types and meeting each other to form a p-n junction, the plate electrode being at a plate-to-body voltage relative to the body electrode, the gate electrode being at a gate-to-body voltage relative to the body electrode, an inversion layer occurring in the body region along the gate dielectric layer below the gate electrode, the inversion layer comprising multiple variably appearing inversion portions respectively characterized by corresponding different zero-point threshold voltages of like sign, each inversion portion largely appearing/disappearing when the gate-to-body voltage passes through the corresponding zero-point threshold voltage with the plate-to-body voltage at zero, each particular inversion portion meeting the plate region or/and being continuous with another inversion portion whose zero-point threshold voltage is of lower magnitude than the zero-point threshold voltage of that particular inversion portion; and further electronic circuitry having a capacitance signal path for receiving the varactor to enable the further circuitry to perform an electronic function dependent on the varactor, the plate and body electrodes being situated in the capacitance signal path.