Abstract: A semiconductor device includes a gate structure on a substrate and an epitaxial layer adjacent to the gate structure, in which the epitaxial layer includes a first buffer layer, an anisotropic layer on the first buffer layer, a second buffer layer on the first buffer layer, and a bulk layer on the anisotropic layer. Preferably, a concentration of boron in the bulk layer is less than a concentration of boron in the anisotropic layer, a concentration of boron in the first buffer layer is less than a concentration of boron in the second buffer layer, and the concentration of boron in the second buffer layer is less than the concentration of boron in the anisotropic layer.

Abstract: A method for fabricating a semiconductor device includes the steps of forming a metal gate on a substrate, a spacer around the metal gate, and a first interlayer dielectric (ILD) layer around the spacer, performing a plasma treatment process to transform the spacer into a first bottom portion and a first top portion, performing a cleaning process to remove the first top portion, and forming a second ILD layer on the metal gate and the first ILD layer.

Abstract: A semiconductor device includes a substrate and a gate structure. The gate structure is disposed on the substrate, and the gate structure includes a titanium nitride barrier layer a titanium aluminide layer, and a middle layer. The titanium aluminide layer is disposed on the titanium nitride barrier layer, and the middle layer is disposed between the titanium aluminide layer and the titanium nitride barrier layer. The middle layer is directly connected with the titanium aluminide layer and the titanium nitride barrier layer, and the middle layer includes titanium and nitrogen. A concentration of nitrogen in the middle layer is gradually decreased in a vertical direction towards an interface between the middle layer and the titanium aluminide layer.

Abstract: A method for fabricating semiconductor device includes the steps of first providing a substrate having a first region and a second region, forming a first bottom barrier metal (BBM) layer on the first region and the second region, forming a first work function metal (WFM) layer on the first BBM layer on the first region and the second region, and then forming a diffusion barrier layer on the first WFM layer.

Abstract: A method for fabricating semiconductor device includes the steps of first providing a substrate having a first region and a second region, forming a first bottom barrier metal (BBM) layer on the first region and the second region, forming a first work function metal (WFM) layer on the first BBM layer on the first region and the second region, and then forming a diffusion barrier layer on the first WFM layer.

Abstract: A method for fabricating semiconductor device includes the steps of first providing a substrate having a first region and a second region, forming a first bottom barrier metal (BBM) layer on the first region and the second region, forming a first work function metal (WFM) layer on the first BBM layer on the first region and the second region, and then forming a diffusion barrier layer on the first WFM layer.

Abstract: A first gate and a second gate are formed on a substrate with a gap between the first and second gates. The first gate has a first sidewall. The second gate has a second sidewall directly facing the first sidewall. A first sidewall spacer is disposed on the first sidewall. A second sidewall spacer is disposed on the second sidewall. A contact etch stop layer is deposited on the first and second gates and on the first and second sidewall spacers. The contact etch stop layer is subjected to a tilt-angle plasma etching process to trim a corner portion of the contact etch stop layer. An inter-layer dielectric layer is then deposited on the contact etch stop layer and into the gap.

Abstract: A method for fabricating p-type field effect transistor (FET) includes the steps of first providing a substrate, forming a pad layer on the substrate, forming a well in the substrate, performing an ion implantation process to implant germanium ions into the substrate to form a channel region, and then conducting an anneal process to divide the channel region into a top portion and a bottom portion. After removing the pad layer, a gate structure is formed on the substrate and a lightly doped drain (LDD) is formed adjacent to two sides of the gate structure.

Abstract: A semiconductor device includes a substrate and a gate structure. The gate structure is disposed on the substrate, and the gate structure includes a titanium nitride barrier layer a titanium aluminide layer, and a middle layer. The titanium aluminide layer is disposed on the titanium nitride barrier layer, and the middle layer is disposed between the titanium aluminide layer and the titanium nitride barrier layer. The middle layer is directly connected with the titanium aluminide layer and the titanium nitride barrier layer, and the middle layer includes titanium and nitrogen. A concentration of nitrogen in the middle layer is gradually decreased in a vertical direction towards an interface between the middle layer and the titanium aluminide layer.

Abstract: A method for fabricating a semiconductor device includes the steps of forming a metal gate on a substrate, a spacer around the metal gate, and a first interlayer dielectric (ILD) layer around the spacer, performing a plasma treatment process to transform the spacer into a first bottom portion and a first top portion, performing a cleaning process to remove the first top portion, and forming a second ILD layer on the metal gate and the first ILD layer.

Abstract: A semiconductor device includes a substrate and a gate structure. The gate structure is disposed on the substrate, and the gate structure includes a titanium nitride barrier layer and a titanium aluminide layer. The titanium aluminide layer is disposed on the titanium nitride barrier layer, and a thickness of the titanium aluminide layer ranges from twice a thickness of the titanium nitride barrier layer to three times the thickness of the titanium nitride barrier layer.

Abstract: A semiconductor device includes a substrate and a gate structure. The gate structure is disposed on the substrate, and the gate structure includes a titanium nitride barrier layer and a titanium aluminide layer. The titanium aluminide layer is disposed on the titanium nitride barrier layer, and a thickness of the titanium aluminide layer ranges from twice a thickness of the titanium nitride barrier layer to three times the thickness of the titanium nitride barrier layer.

Abstract: A method for fabricating semiconductor device includes the steps of first providing a substrate having a first region and a second region, forming a first bottom barrier metal (BBM) layer on the first region and the second region, forming a first work function metal (WFM) layer on the first BBM layer on the first region and the second region, and then forming a diffusion barrier layer on the first WFM layer.

Abstract: A method for fabricating p-type field effect transistor (FET) includes the steps of first providing a substrate, forming a pad layer on the substrate, forming a well in the substrate, performing an ion implantation process to implant germanium ions into the substrate to form a channel region, and then conducting an anneal process to divide the channel region into a top portion and a bottom portion. After removing the pad layer, a gate structure is formed on the substrate and a lightly doped drain (LDD) is formed adjacent to two sides of the gate structure.

Abstract: A semiconductor device includes a substrate having a first region and a second region and a gate structure on the first region and the second region of the substrate. The gate structure includes a first bottom barrier metal (BBM) layer on the first region and the second region, a first work function metal (WFM) layer on the first region; and a diffusion barrier layer on a top surface and a sidewall of the first WFM layer on the first region and the first BBM layer on the second region. Preferably, a thickness of the first BBM layer on the second region is less than a thickness of the first BBM layer on the first region.

Abstract: A p-type field effect transistor (pFET) includes a gate structure on a substrate, a channel region in the substrate directly under the gate structure, and a source/drain region adjacent to two sides of the gate structure. Preferably, the channel region includes a top portion and a bottom portion, in which a concentration of germanium in the bottom portion is lower than a concentration of germanium in the top portion and a depth of the top portion is equal to a depth of the bottom portion.

Abstract: A first gate and a second gate are formed on a substrate with a gap between the first and second gates. The first gate has a first sidewall. The second gate has a second sidewall directly facing the first sidewall. A first sidewall spacer is disposed on the first sidewall. A second sidewall spacer is disposed on the second sidewall. A contact etch stop layer is deposited on the first and second gates and on the first and second sidewall spacers. The contact etch stop layer is subjected to a tilt-angle plasma etching process to trim a corner portion of the contact etch stop layer. An inter-layer dielectric layer is then deposited on the contact etch stop layer and into the gap.

Abstract: A first dummy gate and a second dummy gate are formed on a substrate with a gap between the first and second dummy gates. The first dummy gate has a first sidewall. The second dummy gate has a second sidewall directly facing the first sidewall. A first sidewall spacer is disposed on the first sidewall. A second sidewall spacer is disposed on the second sidewall. A contact etch stop layer is deposited on the first and second dummy gates and on the first and second sidewall spacers. The contact etch stop layer is subjected to a tilt-angle plasma etching process to trim a corner portion of the contact etch stop layer. An inter-layer dielectric layer is then deposited on the contact etch stop layer and into the gap.

Abstract: A semiconductor device includes a substrate having a first region and a second region and a gate structure on the first region and the second region of the substrate. The gate structure includes a first bottom barrier metal (BBM) layer on the first region and the second region, a first work function metal (WFM) layer on the first region; and a diffusion barrier layer on a top surface and a sidewall of the first WFM layer on the first region and the first BBM layer on the second region. Preferably, a thickness of the first BBM layer on the second region is less than a thickness of the first BBM layer on the first region.

Abstract: A method for fabricating semiconductor device includes the steps of: providing a substrate having a first region and a second region; forming a first bottom barrier metal (BBM) layer on the first region and the second region; forming a first work function metal layer on the first BBM layer on the first region and the second region; removing the first work function metal (WFM) layer and part of the first BBM layer on the second region; and forming a diffusion barrier layer on the first WFM layer on the first region and the first BBM layer on the second region.