Various particular embodiments include a semiconductor varactor structure including: a semiconductor substrate of a first conductivity type; a semiconductor area of a second conductivity type, different from the first conductivity type, within the semiconductor substrate; a field effect transistor (FET) structure within the semiconductor area; and a contact, contacting the semiconductor area, for applying a voltage bias to the semiconductor area.

Various particular embodiments include a semiconductor varactor structure including: a semiconductor substrate of a first conductivity type; a semiconductor area of a second conductivity type, different from the first conductivity type, within the semiconductor substrate; a field effect transistor (FET) structure within the semiconductor area; and a contact, contacting the semiconductor area, for applying a voltage bias to the semiconductor area.

A semiconductor device includes a substrate and a plurality of source/drain (S/D) regions in the substrate, wherein each of the plurality of S/D regions includes a first dopant having a first dopant type, and the each of the plurality of S/D regions are electrically coupled together. The semiconductor device further includes a gate stack over the substrate. The semiconductor device further includes a channel region in the substrate, wherein the channel region is below the gate stack and between adjacent S/D regions of the plurality of S/D regions, the channel region includes a second dopant having the first dopant type, and a concentration of the second dopant in the channel region is less than a concentration of the first dopant in each of the plurality of S/D regions.

Embodiments are provided herein for low loss coupling capacitor structures. The embodiments include a n-type varactor (NVAR) configuration and p-type varactor (PVAR) configuration. The structure in the NVAR configuration comprises a p-doped semiconductor substrate (Psub), a deep n-doped semiconductor well (DNW) in the Psub, and a p-doped semiconductor well (P well) in the DNW. The circuit structure further comprises a source terminal of a p-doped semiconductor material within P well, and a drain terminal of the p-doped semiconductor material within the P well. Additionally, the circuit structure comprises an insulated gate on the surface of the P well, a metal pattern comprising a plurality of layers of metal lines, and a plurality of vias through the metal lines. The vias are contacts connecting the metal lines to the gate, the source terminal, and the drain terminal.

Embodiments are provided herein for low loss coupling capacitor structures. The embodiments include a n-type varactor (NVAR) configuration and p-type varactor (PVAR) configuration. The structure in the NVAR configuration comprises a p-doped semiconductor substrate (Psub), a deep n-doped semiconductor well (DNW) in the Psub, and a p-doped semiconductor well (P well) in the DNW. The circuit structure further comprises a source terminal of a p-doped semiconductor material within P well, and a drain terminal of the p-doped semiconductor material within the P well. Additionally, the circuit structure comprises an insulated gate on the surface of the P well, a metal pattern comprising a plurality of layers of metal lines, and a plurality of vias through the metal lines. The vias are contacts connecting the metal lines to the gate, the source terminal, and the drain terminal.

A method of forming a vertical fin field effect transistor having a consistent channel width, including forming one or more vertical fin(s) on the substrate, wherein the one or more vertical fin(s) have a tapered profile, oxidizing the one or more vertical fin(s) to form an oxide by consuming at least a portion of the vertical fin material, and removing the oxide from the one or more vertical fin(s), wherein the one or more vertical fin(s) include a tapered upper portion, a tapered lower portion and a straight channel portion there between.

A semiconductor device and a corresponding circuit for shunting current in a circuit protection configuration is disclosed. An example device includes a first semiconductor region having an anode electrical contact, a second semiconductor region having a cathode electrical contact, a third semiconductor region extending between the first semiconductor region and the second semiconductor region, the second semiconductor region and the third semiconductor region forming a PN junction therebetween, and a gate coupled to the third semiconductor region. The gate is controllable between a first mode in which additional space charges are induced in the semiconductor region to deplete the semiconductor region, and a second mode in which additional space charges are not induced in the semiconductor region.

A semiconductor device and a corresponding circuit for shunting current in a circuit protection configuration is disclosed. An example device includes a first semiconductor region having an anode electrical contact, a second semiconductor region having a cathode electrical contact, a third semiconductor region extending between the first semiconductor region and the second semiconductor region, the second semiconductor region and the third semiconductor region forming a PN junction therebetween, and a gate coupled to the third semiconductor region. The gate is controllable between a first mode in which additional space charges are induced in the semiconductor region to deplete the semiconductor region, and a second mode in which additional space charges are not induced in the semiconductor region.

A low noise device includes an isolation feature in a substrate. The low noise device further includes a gate stack over a channel in the substrate. The gate stack includes a gate dielectric layer extending over a portion of the isolation feature, and a gate electrode over the gate dielectric layer. The low noise device further includes a charge trapping reducing structure adjacent to the isolation feature. The charge trapping reducing structure is configured to reduce a number of charge carriers adjacent an interface between the isolation feature and the channel.

A low noise device includes an isolation feature in a substrate. The low noise device further includes a gate stack over a channel in the substrate. The gate stack includes a gate dielectric layer extending over a portion of the isolation feature, and a gate electrode over the gate dielectric layer. The low noise device further includes a charge trapping reducing structure adjacent to the isolation feature. The charge trapping reducing structure is configured to reduce a number of charge carriers adjacent an interface between the isolation feature and the channel.