A symmetric varactor structure may include a first varactor component. The first varactor component may include a gate operating as a second plate, a gate oxide layer operating as a dielectric layer and a body operating as a first plate of an area modulating capacitor. In addition, doped regions may surround the body of the first varactor component. The first varactor component may be supported on a backside by an isolation layer. The symmetric varactor structure may also include a second varactor component electrically coupled to the backside of the first varactor component through a backside conductive layer.

Embodiments include semiconductor devices related to compound varactor circuits. Specifically, a semiconductor device may be constructed of a modified anti-series string of varactor pairs, wherein one varactor in a varactor pair has an effective area larger than the other varactor. Varactor pairs in the anti-series string are arranged such that adjacent varactors coupling varactor pairs have equal effective areas. In some embodiments, the anti-series string may have four varactors (two varactor pairs.) In other embodiments, the anti-series string may have eight varactors (four varactor pairs) or twelve varactors (six varactor pairs). The compound varactor using the modified anti-series string of varactor pairs may be advantageous in reducing second harmonics related to parasitic capacitances in anti-series varactor applications.

The invention provides a layout pattern of a semiconductor varactor, which comprises a plurality of varactor units arranged on a substrate, wherein each varactor unit comprises a plurality of fin structures arranged in parallel with each other, a plurality of gate structures arranged in parallel with each other, located on the substrate and spanning the fin structures, and a gate metal layer electrically connected with the plurality of gate structures.

The present disclosure provides a semiconductor device and a method of manufacturing a semiconductor device. The semiconductor device comprises a substrate, a first gate electrode, a second gate electrode, a first doped region, a second doped region, a third doped region, and a first interconnection structure. The substrate comprises a well region of a first conductive type. The first and second gate electrodes are disposed on the substrate. The first, second, and third doped regions are embedded within the well region and are of the first conductive type. The first interconnection structure electrically connects the first gate electrode and the second gate electrode. The first doped region and the second doped region are disposed on opposite sides of the first gate electrode.

Various embodiments of the present disclosure are directed towards an integrated chip including a first doped region in a substrate and comprising a first doping type. A gate structure is over the first doped region. A pair of contact regions are in the substrate on opposing sides of the gate structure and comprising the first doping type. The first doped region continuously laterally extends between the pair of contact regions and contacts the pair of contact regions. A second doped region is in the substrate and along a bottom of the first doped region. The second doped region comprises a second doping type opposite the first doping type.

Various embodiments of the present disclosure are directed towards an integrated chip including a well region in a substrate and comprising a first dopant type. A dielectric layer is over the well region. A conductive structure is over the dielectric layer. A first doped region and a second doped region are in the substrate and comprise the first dopant type. The conductive structure is spaced laterally between the first and second doped regions. A depletion enhancement region is in the substrate and is below the well region. The depletion enhancement region comprises a second dopant type different from the first dopant type and buts a bottom of the well region.

A semiconductor device includes: fin structures on a well region; gate structures on the fin structures and spaced apart from one another; a buffer structure contacting each of the gate structures; at least one terminal on the buffer structure; source/drain (S/D) electrodes on the fin structures, wherein: the S/D electrodes alternate with the gate structures, and the S/D electrodes include two outermost S/D electrodes and at least one S/D electrode between the two outermost S/D electrodes; a first interconnection structure electrically connected to each of the gate structures, wherein: the first interconnection structure is electrically connected to the gate structures through the at least one terminal and the buffer structure; and a second interconnection structure electrically connected to the two outermost S/D electrodes, and being free of a connection to the at least one S/D electrode between the two outermost S/D electrodes.

A device includes a first capacitor and a second capacitor connected to the first capacitor in parallel. The first capacitor includes a semiconductor region and a first plurality of gate stacks. The first plurality of gate stacks comprise a plurality of gate dielectrics over and contacting the semiconductor region, and a plurality of gate electrodes over the plurality of gate dielectrics. The second capacitor includes an isolation region, a second plurality of gate stacks over the isolation region, and a plurality of conductive strips over the isolation region and parallel to the second plurality of gate stacks. The second plurality of gate stacks and the plurality of conductive strips are laid out alternatingly.