Abstract: A semiconductor device includes a layer having a semiconductive material. The layer includes an outwardly-protruding fin structure. An isolation structure is disposed over the layer but not over the fin structure. A first spacer and a second spacer are each disposed over the isolation structure and on sidewalls of the fin structure. The first spacer is disposed on a first sidewall of the fin structure. The second spacer is disposed on a second sidewall of the fin structure opposite the first sidewall. The second spacer is substantially taller than the first spacer. An epi-layer is grown on the fin structure. The epi-layer protrudes laterally. A lateral protrusion of the epi-layer is asymmetrical with respect to the first side and the second side.

Abstract: An embodiment is a semiconductor structure. The semiconductor structure includes a substrate. A fin is on the substrate. The fin includes silicon germanium. An interfacial layer is over the fin. The interfacial layer has a thickness in a range from greater than 0 nm to about 4 nm. A source/drain region is over the interfacial layer. The source/drain region includes silicon germanium.

Abstract: A semiconductor device including a source/drain region having a V-shaped bottom surface and extending below gate spacers adjacent a gate stack and a method of forming the same are disclosed. In an embodiment, a method includes forming a gate stack over a fin; forming a gate spacer on a sidewall of the gate stack; etching the fin with a first anisotropic etch process to form a first recess adjacent the gate spacer; etching the fin with a second etch process using etchants different from the first etch process to remove an etching residue from the first recess; etching surfaces of the first recess with a third anisotropic etch process using etchants different from the first etch process to form a second recess extending below the gate spacer and having a V-shaped bottom surface; and epitaxially forming a source/drain region in the second recess.

Abstract: A semiconductor device includes a layer having a semiconductive material. The layer includes an outwardly-protruding fin structure. An isolation structure is disposed over the layer but not over the fin structure. A first spacer and a second spacer are each disposed over the isolation structure and on sidewalls of the fin structure. The first spacer is disposed on a first sidewall of the fin structure. The second spacer is disposed on a second sidewall of the fin structure opposite the first sidewall. The second spacer is substantially taller than the first spacer. An epi-layer is grown on the fin structure. The epi-layer protrudes laterally. A lateral protrusion of the epi-layer is asymmetrical with respect to the first side and the second side.

Abstract: A semiconductor structure includes a substrate, first fins extending from the substrate with a first fin pitch, and second fins extending from the substrate with a second fin pitch that is smaller than the first fin pitch. The semiconductor structure also includes first gate structures engaging the first fins, second gate structures engaging the second fins, first epitaxial semiconductor features adjacent the first gate structures, and second epitaxial semiconductor features adjacent the second gate structures. The first epitaxial semiconductor features are partially embedded in the first fins at a first depth, and the second epitaxial semiconductor features are partially embedded in the second fins at a second depth that is smaller than the first depth.

Abstract: A semiconductor device includes first and second semiconductor fins extending from a substrate and a source/drain region epitaxially grown in recesses of the first and second semiconductor fins. A top surface of the source/drain region is higher than a surface level with top surfaces of the first and second semiconductor fins. The source/drain region includes a plurality of buffer layers. Respective layers of the plurality of buffer layers are embedded between respective layers of the source/drain region. Each of the plurality of buffer layers may have an average thickness in a range of about 2 ? to about 30 ?.

Abstract: A semiconductor structure includes a first region. The first region includes at least three first gate structures separate one from another and adjacent to each other and at least three second gate structures separate one from another and adjacent to each other. The first gate structures are further away from each other than the second gate structures. The first region further includes first epitaxial semiconductor features proximate the first gate structures and second epitaxial semiconductor features proximate the second gate structures. A first distance from the first epitaxial semiconductor features to the respective first gate structures is smaller than a second distance from the second epitaxial semiconductor features to the respective second gate structures.

Abstract: A transistor is provided including a source-drain region, the source-drain region including a first layer wherein a first average silicon content is between about 80% and 100%, a second layer wherein a second average silicon content is between zero and about 90%, the second average silicon content being smaller than the first average silicon content by at least 7%, and the second layer disposed on and adjacent the first layer, a third layer wherein a third average silicon content is between about 80% and 100%, and a fourth layer wherein a fourth average silicon content is between zero and about 90%, the fourth average silicon content being smaller than the third average silicon content by at least 7%, and the fourth layer disposed on and adjacent the third layer.

Abstract: An embodiment is a semiconductor structure. The semiconductor structure includes a substrate. A fin is on the substrate. The fin includes silicon germanium. An interfacial layer is over the fin. The interfacial layer has a thickness in a range from greater than 0 nm to about 4 nm. A source/drain region is over the interfacial layer. The source/drain region includes silicon germanium.

Abstract: An embodiment is a semiconductor structure. The semiconductor structure includes a substrate. A fin is on the substrate. The fin includes silicon germanium. An interfacial layer is over the fin. The interfacial layer has a thickness in a range from greater than 0 nm to about 4 nm. A source/drain region is over the interfacial layer. The source/drain region includes silicon germanium.

Abstract: An embodiment is a semiconductor structure. The semiconductor structure includes a substrate. A fin is on the substrate. The fin includes silicon germanium. An interfacial layer is over the fin. The interfacial layer has a thickness in a range from greater than 0 nm to about 4 nm. A source/drain region is over the interfacial layer. The source/drain region includes silicon germanium.

Abstract: A semiconductor device includes a layer having a semiconductive material. The layer includes an outwardly-protruding fin structure. An isolation structure is disposed over the layer but not over the fin structure. A first spacer and a second spacer are each disposed over the isolation structure and on sidewalls of the fin structure. The first spacer is disposed on a first sidewall of the fin structure. The second spacer is disposed on a second sidewall of the fin structure opposite the first sidewall. The second spacer is substantially taller than the first spacer. An epi-layer is grown on the fin structure. The epi-layer protrudes laterally. A lateral protrusion of the epi-layer is asymmetrical with respect to the first side and the second side.

Abstract: A semiconductor structure includes a first region. The first region includes at least three first gate structures separate one from another and adjacent to each other and at least three second gate structures separate one from another and adjacent to each other. The first gate structures are further away from each other than the second gate structures. The first region further includes first epitaxial semiconductor features proximate the first gate structures and second epitaxial semiconductor features proximate the second gate structures. A first distance from the first epitaxial semiconductor features to the respective first gate structures is smaller than a second distance from the second epitaxial semiconductor features to the respective second gate structures.

Abstract: A semiconductor device includes a first fin structure for a first fin field effect transistor (PET). The first fin structure includes a first base layer protruding from a substrate, a first intermediate layer disposed over the first base layer and a first channel layer disposed over the first intermediate layer. The first fin structure further includes a first protective layer made of a material that prevents an underlying layer from oxidation. The first channel layer is made of SiGe, the first intermediate layer includes a first semiconductor (e.g., SiGe) layer disposed over the first base layer and a second semiconductor layer (e.g., Si) disposed over the first semiconductor layer. The first protective layer covers side walls of the first base layer, side walls of the first semiconductor layer and side walls of the second semiconductor layer.

Abstract: A semiconductor device includes a substrate, at least one first isolation structure, at least two second isolation structures, and a plurality of epitaxy structures. The substrate has a plurality of semiconductor fins therein. The first isolation structure is disposed between the semiconductor fins. The semiconductor fins are disposed between the second isolation structures, and the second isolation structures extend into the substrate further than the first isolation structure. The epitaxy structures are respectively disposed on the semiconductor fins. The epitaxy structures are separated from each other, and at least one of the epitaxy structures has a substantially round profile.

Abstract: A semiconductor structure includes a substrate, first gate structures and second gate structures over the substrate, third epitaxial semiconductor features proximate the first gate structures, and fourth epitaxial semiconductor features proximate the second gate structures. The first gate structures have a greater pitch than the second gate structures. The third and fourth epitaxial semiconductor features are at least partially embedded in the substrate. A first proximity of the third epitaxial semiconductor features to the respective first gate structures is smaller than a second proximity of the fourth epitaxial semiconductor features to the respective second gate structures. In an embodiment, a first depth of the third epitaxial semiconductor features embedded into the substrate is greater than a second depth of the fourth epitaxial semiconductor features embedded into the substrate.

Abstract: A semiconductor device includes a fin structure for a fin field effect transistor (FET). The fin structure includes a base layer protruding from a substrate, an intermediate layer disposed over the base layer and an upper layer disposed over the intermediate layer. The fin structure further includes a first protective layer and a second protective layer made of a different material than the first protective layer. The intermediate layer includes a first semiconductor layer disposed over the base layer, the first protective layer covers at least side walls of the first semiconductor layer and the second protective layer covers at least side walls of the first protective layer.

Abstract: A semiconductor device includes a first fin structure for a first fin field effect transistor (FET). The first fin structure includes a first base layer protruding from a substrate, a first intermediate layer disposed over the first base layer and a first channel layer disposed over the first intermediate layer. The first fin structure further includes a first protective layer made of a material that prevents an underlying layer from oxidation. The first channel layer is made of SiGe, the first intermediate layer includes a first semiconductor (e.g., SiGe) layer disposed over the first base layer and a second semiconductor layer (e.g., Si) disposed over the first semiconductor layer. The first protective layer covers side walls of the first base layer, side walls of the first semiconductor layer and side walls of the second semiconductor layer.

Abstract: A semiconductor structure includes a substrate, first gate structures and second gate structures over the substrate, third epitaxial semiconductor features proximate the first gate structures, and fourth epitaxial semiconductor features proximate the second gate structures. The first gate structures have a greater pitch than the second gate structures. The third and fourth epitaxial semiconductor features are at least partially embedded in the substrate. A first proximity of the third epitaxial semiconductor features to the respective first gate structures is smaller than a second proximity of the fourth epitaxial semiconductor features to the respective second gate structures. In an embodiment, a first depth of the third epitaxial semiconductor features embedded into the substrate is greater than a second depth of the fourth epitaxial semiconductor features embedded into the substrate.

Abstract: A semiconductor device includes a first fin structure for a first fin field effect transistor (PET). The first fin structure includes a first base layer protruding from a substrate, a first intermediate layer disposed over the first base layer and a first channel layer disposed over the first intermediate layer. The first fin structure further includes a first protective layer made of a material that prevents an underlying layer from oxidation. The first channel layer is made of SiGe, the first intermediate layer includes a first semiconductor (e.g., SiGe) layer disposed over the first base layer and a second semiconductor layer (e.g., Si) disposed over the first semiconductor layer. The first protective layer covers side walls of the first base layer, side walls of the first semiconductor layer and side walls of the second semiconductor layer.