Abstract: A semiconductor device includes a composite gate structure formed over a semiconductor substrate. The composite gate structure includes a gate dielectric layer, a metal layer, and a semiconductor layer. The metal layer is disposed on the gate dielectric layer. The semiconductor layer is disposed on the gate dielectric layer. The metal layer surrounds the semiconductor layer.

Abstract: A semiconductor device and method of forming the same are provided. The semiconductor device includes a substrate, a growth promoting region, a first gate stack, and a second gate stack. The substrate includes a first region and a second region. The growth promoting region is located in a surface of the substrate in the first region. The growth promoting region includes a first implantation species, and a surface of the substrate in the second region is free of the first implantation species. The first gate stack includes a first gate dielectric layer on the substrate in the first region. The second gate stack includes a second gate dielectric layer on the substrate in the second region.

Abstract: Provided is a semiconductor device including a substrate having a first conductivity type, an isolation structure, a well region having the first conductivity type, a gate structure, and doped regions having a second conductivity type. The isolation structure is disposed in the substrate to form an active region of the substrate. The well region is disposed in the active region and surrounds sidewalls of the isolation structure to form a native region in the active region. The gate structure is disposed over the substrate in the native region. The doped regions are disposed respectively in the well region and the native region of the substrate at two sides of the gate structure. A method of fabricating the semiconductor device is also provided.

Abstract: A method of making a semiconductor device includes depositing an isolation region between adjacent fins of a plurality of fins over a substrate, wherein a top-most surface of the isolation region is a first distance from a bottom of the substrate. The method further includes doping each of the plurality of fins with a first dopant having a first dopant type to define a first doped region in each of the plurality of fins, wherein a bottom-most surface of the first doped region is a second distance from the bottom of the substrate, and the second distance is greater than the first distance. The method further includes doping each of the plurality of fins with a second dopant having a second dopant type to define a second doped region in each of the plurality of fins, wherein the second doped region contacts the isolation region.

Abstract: A semiconductor device includes a composite gate structure formed over a semiconductor substrate. The composite gate structure includes a gate dielectric layer, a metal layer, and a semiconductor layer. The metal layer is disposed on the gate dielectric layer. The semiconductor layer is disposed on the gate dielectric layer. The metal layer surrounds the semiconductor layer.

Abstract: A junction gate field-effect transistor (JFET) includes a substrate, a source region formed in the substrate, a drain region formed in the substrate, a channel region formed in the substrate, and at least one gate region formed in the substrate. The channel region connects the source and drain regions. The at least one gate region contacts one of the source and drain regions at an interface, and the at least one gate region is isolated from the other of the source and drain regions. A dielectric layer covers the interface while exposing portions of the gate region and the one of the source and drain regions.

Abstract: A method for manufacturing a semiconductor device includes forming one or more fins extending in a first direction over a substrate. The one or more fins include a first region along the first direction and second regions on both sides of the first region along the first direction. A dopant is implanted in the first region of the fins but not in the second regions. A gate structure overlies the first region of the fins and source/drains are formed on the second regions of the fins.

Abstract: FinFET varactors having low threshold voltages and methods of making the same are disclosed herein. An exemplary FinFET varactor includes a fin and a gate structure disposed over a portion of the fin, such that the gate structure is disposed between a first source/drain feature and a second source/drain feature that include a first type dopant. The portion of the fin includes the first type dopant and a second type dopant. A dopant concentration of the first type dopant and a dopant concentration of the second type dopant vary from an interface between the fin and the gate structure to a first depth in the fin. The dopant concentration of the first type dopant is greater than the dopant concentration of the second type dopant from a second depth to a third depth in the fin, where the second depth and the third depth are less than the first depth.

Abstract: Provided is a semiconductor device includes a gate stack, a first doped region, a second doped region, a first lightly doped region and a second lightly doped region. The gate stack is disposed on a substrate. The first doped region is located in the substrate at a first side of the gate stack. The second doped region is located in the substrate at a second side of the gate stack. The first lightly doped region is located in the substrate between the gate stack and the first doped region. The second lightly doped region is located in the substrate between the gate stack and the second doped region. A property of the first lightly doped region is different from a property of the second lightly doped region.

Abstract: A method of determining the reliability of a high-voltage PMOS (HVPMOS) device includes determining a bulk resistance of the HVPMOS device, and evaluating the reliability of the HVPMOS device based on the bulk resistance.

Abstract: A semiconductor device includes a plurality of fins over a substrate. Each fin of the plurality of fins extends in a first direction substantially perpendicular to a bottom surface of the substrate, and each fin of the plurality of fins comprises a first doped region having a first dopant type. The semiconductor device further includes an isolation region over the substrate between a first fin of the plurality of fins and a second fin of the plurality of fins adjacent to the first fin. The semiconductor device further includes a second doped region extends continuously across the isolation region, the second doped region extends into each fin of the plurality of fins, and a dimension of the second doped region in the isolation region in a second direction perpendicular to the first direction is less than a dimension of the at least one isolation region in the second direction.

Abstract: A method includes forming a gate structure, a first edge structure and a second edge structure on a semiconductor strip. The method includes forming a first source/drain feature between the gate structure and the first edge structure; and a second source/drain feature between the gate structure and the second edge structure. A distance between the gate structure and the first source/drain feature is from about 1.5 to about 4.5 times greater than a distance between the gate structure and the second source/drain feature. The method includes implanting a buried channel in the semiconductor strip. A top surface of the buried channel is spaced from a top surface of the semiconductor strip. A bottom surface of the buried channel is closer to the top surface of the semiconductor strip than a bottom surface of the first source/drain feature. A dopant concentration of the buried channel is highest under the gate structure.

Abstract: A method for manufacturing a semiconductor device includes forming one or more fins extending in a first direction over a substrate. The one or more fins include a first region along the first direction and second regions on both sides of the first region along the first direction. A dopant is implanted in the first region of the fins but not in the second regions. A gate structure overlies the first region of the fins and source/drains are formed on the second regions of the fins.

Abstract: A junction gate field-effect transistor (JFET) includes a substrate, a source region formed in the substrate, a drain region formed in the substrate, a channel region formed in the substrate, and at least one gate region formed in the substrate. The channel region connects the source and drain regions. The at least one gate region contacts one of the source and drain regions at an interface, and the at least one gate region is isolated from the other of the source and drain regions. A dielectric layer covers the interface while exposing portions of the gate region and the one of the source and drain regions.

Abstract: Disclosed is a FinFET varactor with low threshold voltage and methods of making the same. A disclosed method includes receiving a semiconductor layer over a substrate and having channel, source, and drain regions. The method includes forming a well in the semiconductor layer to have a first dopant, and implanting a second dopant into the well. The first and second dopants are of opposite doping types. A first portion of the well has a higher concentration of the second dopant than the first dopant. A second portion of the well under the first portion has a higher concentration of the first dopant than the second dopant. The method further includes forming a gate stack over the channel region, and forming source and drain features in the source and drain regions. The first portion of the well electrically connects the source and drain features.

Abstract: FinFET varactors having low threshold voltages and methods of making the same are disclosed herein. An exemplary FinFET varactor includes a fin and a gate structure disposed over a portion of the fin, such that the gate structure is disposed between a first source/drain feature and a second source/drain feature that include a first type dopant. The portion of the fin includes the first type dopant and a second type dopant. A dopant concentration of the first type dopant and a dopant concentration of the second type dopant vary from an interface between the fin and the gate structure to a first depth in the fin. The dopant concentration of the first type dopant is greater than the dopant concentration of the second type dopant from a second depth to a third depth in the fin, where the second depth and the third depth are less than the first depth.

Abstract: A method of determining the reliability of a high-voltage PMOS (HVPMOS) device includes determining a bulk resistance of the HVPMOS device, and evaluating the reliability of the HVPMOS device based on the bulk resistance.

Abstract: Provided is a semiconductor device including a substrate having a first conductivity type, an isolation structure, a well region having the first conductivity type, a gate structure, and doped regions having a second conductivity type. The isolation structure is disposed in the substrate to form an active region of the substrate. The well region is disposed in the active region and surrounds sidewalls of the isolation structure to form a native region in the active region. The gate structure is disposed over the substrate in the native region. The doped regions are disposed respectively in the well region and the native region of the substrate at two sides of the gate structure. A method of fabricating the semiconductor device is also provided.

Abstract: A device includes a semiconductor substrate of a first conductivity type, and a deep well region in the semiconductor substrate, wherein the deep well region is of a second conductivity type opposite to the first conductivity type. The device further includes a well region of the first conductivity type over the deep well region. The semiconductor substrate has a top portion overlying the well region, and a bottom portion underlying the deep well region, wherein the top portion and the bottom portion are of the first conductivity type, and have a high resistivity. A gate dielectric is over the semiconductor substrate. A gate electrode is over the gate dielectric. A source region and a drain region extend into the top portion of the semiconductor substrate. The source region, the drain region, the gate dielectric, and the gate electrode form a Radio Frequency (RF) switch.

Abstract: A semiconductor device includes a fin extending from a substrate, a first source/drain feature, a second source/drain feature, and a gate structure on the fin. A distance between the gate structure and the first source/drain feature is different from a distance between the gate structure and the second source/drain feature.