A semiconductor device and method of forming the same are described. A semiconductor device includes an active area adjacent a gate structure. The gate structure includes a gate electrode over a gate dielectric, the gate dielectric having a bottom surface in a first plane. A second etch interacts with a first composition and an initial dopant to remove a bottom portion of a first sidewall spacer adjacent the gate structure, such that a bottom surface of the first sidewall spacer lies in a second plane different than the first plane. The removal of the bottom portion of the first sidewall spacer reduces a first distance between a source or drain and a bottom surface of the gate electrode, thus reducing proximity loading of the semiconductor device and improving functionality of the semiconductor device.

An integrated circuit die includes a substrate having a first layer of semiconductor material, a layer of dielectric material on the first layer of semiconductor material, and a second layer of semiconductor material on the layer of dielectric material. An extended channel region of a transistor is positioned in the second layer of semiconductor material, interacting with a top surface, side surfaces, and potentially portions of a bottom surface of the second layer of semiconductor material. A gate dielectric is positioned on a top surface and on the exposed side surface of the second layer of semiconductor material. A gate electrode is positioned on the top surface and the exposed side surface of the second layer of semiconductor material.

A semiconductor device includes a substrate, a liner, and an epitaxy structure. The substrate has a recess. The liner is disposed in the recess. The liner is denser than the substrate. The epitaxy structure is disposed in the recess. The liner is disposed between the epitaxy structure and the substrate.

A method used in fabrication of a recessed access device transistor gate has increased tolerance for mask misalignment. One embodiment of the invention comprises forming a vertical spacing layer over a semiconductor wafer, then etching the vertical spacing layer and the semiconductor wafer to form a recess in the wafer. A conductive transistor gate layer is then formed within the trench and over the vertical spacing layer. The transistor gate layer is etched, which exposes the vertical spacing layer. A spacer layer is formed over the etched conductive gate layer and over the vertical spacing layer, then the spacer layer and the vertical spacing layer are anisotropically etched. Subsequent to anisotropically etching the vertical spacing layer, a portion of the vertical spacing layer is interposed between the semiconductor wafer and the etched conductive transistor gate layer in a direction perpendicular to the plane of a major surface of the semiconductor wafer.

A system and method for forming semiconductor structures is disclosed. An embodiment comprises forming a high diffusibility layer adjacent to a gate stack and forming a low diffusibility layer adjacent to the high diffusibility layer. After these two layers are formed, an anneal is performed to diffuse dopants from the high diffusibility layer underneath the gate stack to help form a channel region.

Semiconductor devices including a stressor in a recess and methods of forming the semiconductor devices are provided. The methods may include forming a fast etching region comprising phosphorous in an active region and forming a first trench in the active region by recessing the fast etching region. The methods may also include forming a second trench in the active region by enlarging the first trench using a directional etch process and forming a stressor in the second trench. The second trench may include a notched portion of the active region.

Embodiments of the present invention describe a epitaxial region on a semiconductor device. In one embodiment, the epitaxial region is deposited onto a substrate via cyclical deposition-etch process. Cavities created underneath the spacer during the cyclical deposition-etch process are backfilled by an epitaxial cap layer. The epitaxial region and epitaxial cap layer improves electron mobility at the channel region, reduces short channel effects and decreases parasitic resistance.

A semiconductor device including a gate electrode disposed on a semiconductor substrate and source/drain regions disposed at both sides of the gate electrode, the source/drain regions being formed by implanting impurities. The source/drain regions include an epitaxial layer formed by epitaxially growing a semiconductor material having a different lattice constant from that of the semiconductor substrate in a recessed position at a side of the gate electrode, and a diffusion layer disposed in a surface layer of the semiconductor substrate.

In an embodiment, a device includes: a first nanostructure over a substrate, the first nanostructure including a channel region and a first lightly doped source/drain region, the first lightly doped source/drain region adjacent the channel region; a first epitaxial source/drain region wrapped around four sides of the first lightly doped source/drain region; an interlayer dielectric over the first epitaxial source/drain region; a source/drain contact extending through the interlayer dielectric, the source/drain contact wrapped around four sides of the first epitaxial source/drain region; and a gate stack adjacent the source/drain contact and the first epitaxial source/drain region, the gate stack wrapped around four sides of the channel region.

In an embodiment, a device includes: a fin on a substrate, fin having a Si portion proximate the substrate and a SiGe portion distal the substrate; a gate stack over a channel region of the fin; a source/drain region adjacent the gate stack; a first doped region in the SiGe portion of the fin, the first doped region disposed between the channel region and the source/drain region, the first doped region having a uniform concentration of a dopant; and a second doped region in the SiGe portion of the fin, the second doped region disposed under the source/drain region, the second doped region having a graded concentration of the dopant decreasing in a direction extending from a top of the fin to a bottom of the fin.