A method for fabricating a semiconductor device includes the steps of first forming a gate structure on a substrate, forming a first spacer adjacent to the gate structure, forming a second spacer adjacent to the first spacer, forming an epitaxial layer adjacent to the second spacer, forming a second cap layer on the epitaxial layer, and then forming a first cap layer on the second cap layer. Preferably, a top surface of the first cap layer includes a V-shape and the first cap layer and the second cap layer are made of different materials.

One illustrative transistor device disclosed herein includes a gate structure positioned above a semiconductor substrate and a source region and a drain region, each of which comprise an epi cavity with a bottom surface and a side surface. The transistor further includes an interface layer positioned on at least one of the side surface and the bottom surface of the epi cavity in each of the source/drain regions, wherein the interface layer comprises a non-semiconductor material and an epi semiconductor material positioned on at least an upper surface of the interface layer in the epi cavity in each of the source region and the drain region.

After a MISFET is formed on a substrate including a semiconductor substrate, an insulating layer and a semiconductor layer, an interlayer insulating film and a first insulating film are formed on the substrate. Also, after an opening is formed in each of the first insulating film and the interlayer insulating film, a second insulating film is formed at each of a bottom portion of the opening and a side surface of the opening and also formed on an upper surface of the first insulating film. Further, each of the second insulating film formed at the bottom portion of the opening and the second insulating film formed on the upper surface of the first insulating film is removed by etching. After that, an inside of the opening is etched under a condition that each of the first insulating film and the second insulating film is less etched than the insulating layer.

A method includes etching a trench in a substrate adjacent to a gate structure, wherein the trench includes a bottom surface and a tip portion extending under a spacer of the gate structure. The method further includes epitaxially growing a first semiconductor material in the trench, wherein the first semiconductor material covers an entirety of the bottom surface of the trench, and the first semiconductor material grows in the tip portion. The method further includes epitaxially growing a second semiconductor material in the trench, wherein the second semiconductor material is different from the first semiconductor material, the second semiconductor material covers the first semiconductor material, and the second semiconductor material directly contacts the substrate between the bottom surface of the trench and the tip portion.

Various embodiments of the present disclosure provide a method for forming a recessed gate electrode that has high thickness uniformity. A gate dielectric layer is deposited lining a recess, and a multilayer film is deposited lining the recess over the gate dielectric layer. The multilayer film comprises a gate electrode layer, a first sacrificial layer over the gate dielectric layer, and a second sacrificial layer over the first sacrificial dielectric layer. A planarization is performed into the second sacrificial layer and stops on the first sacrificial layer. A first etch is performed into the first and second sacrificial layers to remove the first sacrificial layer at sides of the recess. A second etch is performed into the gate electrode layer using the first sacrificial layer as a mask to form the recessed gate electrode. A third etch is performed to remove the first sacrificial layer after the second etch.

The present disclosure provides a semiconductor device including a substrate, a first well and a second well formed in the substrate, the first well being doped with dopants of a first conductivity type and the second well being doped with dopants of a second conductivity type, a third well within the first well, a gate structure partially formed over the first and second wells, and a first epi region on the third well and a drain region electrically coupled to the second well, the first epi region being doped with dopants of the second conductivity type.

A method of fabricating a MOS transistor having a thinned channel region is described. The channel region is etched following removal of a dummy gate. The source and drain regions have relatively low resistance with the process.

An integrated circuit structure includes a gate stack over a semiconductor substrate, and an opening extending into the semiconductor substrate, wherein the opening is adjacent to the gate stack. A first silicon germanium region is in the opening, wherein the first silicon germanium region has a first germanium percentage. A second silicon germanium region is over the first silicon germanium region, wherein the second silicon germanium region has a second germanium percentage higher than the first germanium percentage. A third silicon germanium region is over the second silicon germanium region, wherein the third silicon germanium region has a third germanium percentage lower than the second germanium percentage.

A method for integrating transistors and anti-fuses on a device includes epitaxially growing a semiconductor layer on a substrate and masking a transistor region of the semiconductor layer. An oxide is formed on an anti-fuse region of the semiconductor layer. A semiconductor material is grown over the semiconductor layer to form an epitaxial semiconductor layer in the transistor region and a defective semiconductor layer in the anti-fuse region. Transistor devices in the transistor region and anti-fuse devices in the anti-fuse region are formed wherein the defective semiconductor layer is programmable by an applied field.

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.