A method to form a semiconductor structure with an active region and a compatible dielectric layer is described. In one embodiment, a semiconductor structure has a dielectric layer comprised of an oxide of a first semiconductor material, wherein a second (and compositionally different) semiconductor material is formed between the dielectric layer and the first semiconductor material. In another embodiment, a portion of the second semiconductor material is replaced with a third semiconductor material in order to impart uniaxial strain to the lattice structure of the second semiconductor material.

A method of fabricating a semiconductor device comprises providing a substrate with a shallow trench isolation (STI) within the substrate and a gate stack. A cavity is formed between the gate stack and the STI. The cavity comprises one sidewall formed by the STI, one sidewall formed by the substrate, and a bottom surface formed by the substrate. A film is grown in the cavity and thereafter an opening formed by removing a first portion of the strained film until exposing the bottom surface of the substrate while a second portion of the strained film adjoins the STI sidewall. Another epitaxial layer is then grown in the opening.

An integrated circuit die includes a silicon substrate. PMOS and NMOS transistors are formed on the silicon substrate. The carrier mobilities of the PMOS and NMOS transistors are increased by introducing tensile stress into the channel regions of the NMOS transistors and compressive stress into the channel regions of the PMOS transistors. Tensile stress is introduced by including a region of SiGe below the channel region of the NMOS transistors. Compressive stress is introduced by including regions of SiGe in the source and drain regions of the PMOS transistors.

A method of concurrently forming source/drain contacts (CAs) and gate contacts (CBs) and device are provided. Embodiments include forming metal gates (PC) and source/drain (S/D) regions over a substrate; forming an ILD over the PCs and S/D regions; forming a mask over the ILD; concurrently patterning the mask for formation of CAs adjacent a first portion of each PC and CBs over a second portion of the PCs; etching through the mask, forming trenches extending through the ILD down to a nitride capping layer formed over each PC and a trench silicide (TS) contact formed over each S/D region; selectively growing a metal capping layer over the TS contacts formed over the S/D regions; removing the nitride capping layer from the second portion of each PC; and metal filling the trenches, forming the CAs and CBs.

A semiconductor device includes a substrate comprising a channel region and a recess, wherein the recess is located at both side of the channel region; a gate structure formed over the channel region; a first SiP layer covering bottom corners of the gate structure and the recess; and a second SiP layer formed over the first SiP layer and in the recess, wherein the second SiP layer has a phosphorus concentration higher than that of the first SiP layer.

A semiconductor device includes a substrate including a plurality of transistor devices formed thereon, at least an epitaxial structure formed in between the transistor devices, and a tri-layered structure formed on the epitaxial structure. The epitaxial structure includes a first semiconductor material and a second semiconductor material, and a lattice constant of the second semiconductor material is larger than a lattice constant of the first semiconductor material. The tri-layered structure includes an undoped epitaxial layer, a metal-semiconductor compound layer, and a doped epitaxial layer sandwiched in between the undoped epitaxial layer and the metal-semiconductor compound layer. The undoped epitaxial layer and the doped epitaxial layer include at least the second semiconductor material.

A method of forming matched PFET/NFET spacers with differential widths for SG and EG structures and a method of forming differential width nitride spacers for SG NFET and SG PFET structures and PFET/NFET EG structures and respective resulting devices are provided. Embodiments include providing PFET SG and EG structures and NFET SG and EG structures; forming a first nitride layer over the substrate; forming an oxide liner; forming a second nitride layer on sidewalls of the PFET and NFET EG structures; removing horizontal portions of the first nitride layer and the oxide liner over the PFET SG and EG structures; forming RSD structures on opposite sides of each of the PFET SG and EG structures; removing horizontal portions of the first nitride layer and the oxide liner over the NFET SG and EG structures; and forming RSD structures on opposite sides of each of the NFET SG and EG structures.

A transistor having a narrow bandgap semiconductor source/drain region is described. The transistor includes a gate electrode formed on a gate dielectric layer formed on a silicon layer. A pair of source/drain regions are formed on opposite sides of the gate electrode wherein said pair of source/drain regions comprise a narrow bandgap semiconductor film formed in the silicon layer on opposite sides of the gate electrode.

A semiconductor device includes a semiconductor substrate having a first conductivity type region including a first conductivity type impurity. A first gate structure is on the semiconductor substrate overlying the first conductivity type region. A second conductivity type region including a second conductivity type impurity is formed in the semiconductor substrate. A barrier layer is located between the first conductivity type region and the second conductivity type region. The barrier layer prevents diffusion of the second conductivity type impurity from the second conductivity type region into the first conductivity type region.

A method of forming field effect transistors (FETs) and on Integrated Circuit (IC) chips with the FETs. Channel placeholders at FET locations are undercut at each end of FET channels. Source/drain regions adjacent to each channel placeholder extend into and fill the undercut. The channel placeholder is opened to expose channel surface under each channel placeholder. Source/drain extensions are formed under each channel placeholder, adjacent to each source/drain region. After removing the channel placeholders metal gates are formed over each said FET channel.