Abstract: Mechanisms of forming a semiconductor device structure are provided. The semiconductor device structure includes a substrate and a gate stack structure formed on the substrate. The semiconductor device structure also includes gate spacers formed on sidewalls of the gate stacks. The semiconductor device structure includes doped regions formed in the substrate. The semiconductor device structure also includes a strained source and drain (SSD) structure adjacent to the gate spacers, and the doped regions are adjacent to the SSD structure. The semiconductor device structure includes SSD structure has a tip which is closest to the doped region, and the tip is substantially aligned with an inner side of gate spacers.

Abstract: A structure and a formation method of a semiconductor device structure are provided. The semiconductor device structure includes a semiconductor substrate and a gate stack over the semiconductor substrate. The gate stack includes a work function layer and a metal filling over the work function layer. The semiconductor device structure also includes a dielectric structure over the semiconductor substrate and adjacent to the gate stack. The dielectric structure is in direct contact with the work function layer and the metal filling.

Abstract: Embodiments of mechanisms of forming a semiconductor device structure are provided. The semiconductor device structure includes a substrate and a gate stack structure formed on the substrate. The semiconductor device structure also includes gate spacers formed on sidewalls of the gate stacks. The semiconductor device structure includes doped regions formed in the substrate. The semiconductor device structure also includes a strained source and drain (SSD) structure adjacent to the gate spacers, and the doped regions are adjacent to the SSD structure. The semiconductor device structure includes SSD structure has a tip which is closest to the doped region, and the tip is substantially aligned with an inner side of gate spacers.

Abstract: In some embodiments, a field effect transistor (FET) structure comprises a body structure, dielectric structures, a gate structure and a source or drain region. The gate structure is formed over the body structure. The source or drain region is embedded in the body structure beside the gate structure, and abuts and is extended beyond the dielectric structure. The source or drain region contains stressor material with a lattice constant different from that of the body structure. The source or drain region comprises a first region formed above a first level at a top of the dielectric structures and a second region that comprises downward tapered side walls formed under the first level and abutting the corresponding dielectric structures.

Abstract: Embodiments of mechanisms of forming a semiconductor device structure are provided. The semiconductor device structure includes a substrate and a gate stack structure formed on the substrate. The semiconductor device structure also includes gate spacers formed on sidewalls of the gate stacks. The semiconductor device structure includes doped regions formed in the substrate. The semiconductor device structure also includes a strained source and drain (SSD) structure adjacent to the gate spacers, and the doped regions are adjacent to the SSD structure. The semiconductor device structure includes SSD structure has a tip which is closest to the doped region, and the tip is substantially aligned with an inner side of gate spacers.