Abstract: In an embodiment, an integrated circuit (IC) device comprises a semiconductor substrate, an isolation region and an active region disposed on the semiconductor substrate, a gate stack disposed over the active region, and a source and a drain disposed in the active region and interposed by the gate stack in a first direction. The active region is at least partially surrounded by the isolation region. A middle portion of the active region laterally extends beyond the gate stack in a second direction that is perpendicular to the first direction.

Abstract: A semiconductor device and a method of manufacturing the same are provided. The semiconductor device includes a gate stack, a first doped region, a second doped region, and a buried doped region. The first doped region has a first conductivity type and is located in the substrate at a first side of the gate stack. The second doped region has the first conductivity type and is located in the substrate at a second side of the gate stack. The buried doped region has the first conductivity type and is buried in the substrate, extended from the first doped region to the second doped region, and separated from the gate stack by a distance.

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: In an embodiment, an integrated circuit (IC) device comprises a semiconductor substrate, an isolation region and an active region disposed on the semiconductor substrate, a gate stack disposed over the active region, and a source and a drain disposed in the active region and interposed by the gate stack in a first direction. The active region is at least partially surrounded by the isolation region. A middle portion of the active region laterally extends beyond the gate stack in a second direction that is perpendicular to the first direction.

Abstract: A method of fabricating a semiconductor device includes forming a gate structure, a first edge structure and a second edge structure on a semiconductor strip. The method further includes forming a first source/drain feature between the gate structure and the first edge structure. The method further includes forming a second source/drain feature between the gate structure and the second edge structure, wherein 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. The method further includes implanting a buried channel in the semiconductor strip, wherein the buried channel is entirely below a top-most surface of the semiconductor strip, a maximum depth of the buried channel is less than a maximum depth of the first source/drain feature, and a dopant concentration of the buried channel is highest under the gate structure.

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 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: A method of making a semiconductor device includes etching a substrate to define a trench in a substrate, wherein the trench is adjacent to an active region in the substrate, and etching the substrate includes patterning a mask. The method further includes partially removing the mask to expose a first portion of the active region, wherein the first portion extends a first distance from the trench. The method further includes depositing a dielectric material to fill the trench and cover the first portion of the active region. The method further includes removing the mask, wherein the removing of the mask includes maintaining the dielectric material covering the first portion of the active region. The method further includes forming a gate structure over the active region and over the dielectric material.

Abstract: A semiconductor device includes a substrate and an isolation feature. The isolation feature includes a first portion in the substrate, and a second portion extending along a top surface of the substrate, wherein a bottom surface of the second portion is below the top surface of the substrate. The semiconductor device further includes a gate structure over the substrate, wherein the gate structure extends along a top surface of the second portion of the isolation feature.

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 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 semiconductor device includes a substrate, wherein the substrate includes a channel region. The semiconductor device further includes an isolation feature in the substrate. The isolation feature includes a first portion in the substrate, and a second portion extending along a top surface of the substrate. The second portion partially covers the channel region. The semiconductor device further includes a gate structure over the substrate, wherein the gate structure partially covers the second portion of the isolation feature.

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: 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: 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.

Abstract: In an embodiment, an integrated circuit (IC) device comprises a semiconductor substrate, an isolation region and an active region disposed on the semiconductor substrate, a gate stack disposed over the active region, and a source and a drain disposed in the active region and interposed by the gate stack in a first direction. The active region is at least partially surrounded by the isolation region. A middle portion of the active region laterally extends beyond the gate stack in a second direction that is perpendicular to the first direction.

Abstract: A semiconductor device and a method of manufacturing the same are provided. The semiconductor device includes a gate stack, a first doped region, a second doped region, and a buried doped region. The first doped region has a first conductivity type and is located in the substrate at a first side of the gate stack. The second doped region has the first conductivity type and is located in the substrate at a second side of the gate stack. The buried doped region has the first conductivity type and is buried in the substrate, extended from the first doped region to the second doped region, and separated from the gate stack by a distance.