A device includes a substrate, a buffer layer, a nanowire, a gate structure, and a remnant of a sacrificial layer. The buffer layer is above the substrate. The nanowire is above the buffer layer and includes a pair of source/drain regions and a channel region between the source/drain regions. The gate structure surrounds the channel region. The remnant of the sacrificial layer is between the buffer layer and the nanowire and includes a group III-V semiconductor material.

A method of fabricating a semiconductor device includes forming a fin in a substrate and depositing a spacer material on the fin. The method includes recessing the spacer material so that a surface of the fin is exposed. The method includes removing a portion of the fin within lateral sidewalls of the spacer material to form a recess, leaving a portion of the fin on the lateral sidewalls. The method further includes depositing a semiconductor material within the recess.

A method of fabricating a semiconductor device includes forming a fin in a substrate and depositing a spacer material on the fin. The method includes recessing the spacer material so that a surface of the fin is exposed. The method includes removing a portion of the fin within lateral sidewalls of the spacer material to form a recess, leaving a portion of the fin on the lateral sidewalls. The method further includes depositing a semiconductor material within the recess.

By decoupling the formation of a metal silicide in the gate electrode structure and the raised drain and source regions, superior flexibility in designing transistor elements and managing overall process flow may be achieved. To this end, the metal silicide in the gate electrode structures may be formed prior to actually patterning the gate electrode structures, while, also during this process sequence, a mask material may be applied for reliably covering any device regions in which a silicidation is not required. Consequently, superior gate conductivity may be accomplished, without increasing the risk of silicide penetration into the channel region of sophisticated fully depleted SOI transistors.

By decoupling the formation of a metal silicide in the gate electrode structure and the raised drain and source regions, superior flexibility in designing transistor elements and managing overall process flow may be achieved. To this end, the metal silicide in the gate electrode structures may be formed prior to actually patterning the gate electrode structures, while, also during this process sequence, a mask material may be applied for reliably covering any device regions in which a silicidation is not required. Consequently, superior gate conductivity may be accomplished, without increasing the risk of silicide penetration into the channel region of sophisticated fully depleted SOI transistors.

A device includes a substrate, a buffer layer, a nanowire, a gate structure, and a remnant of a sacrificial layer. The buffer layer is above the substrate. The nanowire is above the buffer layer and includes a pair of source/drain regions and a channel region between the source/drain regions. The gate structure surrounds the channel region. The remnant of the sacrificial layer is between the buffer layer and the nanowire and includes a group III-V semiconductor material.

Techniques are disclosed for transistor gate trench engineering to decrease capacitance and resistance. Sidewall spacers, sometimes referred to as gate spacers, or more generally, spacers, may be formed on either side of a transistor gate to help lower the gate-source/drain capacitance. Such spacers can define a gate trench after dummy gate materials are removed from between the spacers to form the gate trench region during a replacement gate process, for example. In some cases, to reduce resistance inside the gate trench region, techniques can be performed to form a multilayer gate or gate electrode, where the multilayer gate includes a first metal and a second metal above the first metal, where the second metal includes lower electrical resistivity properties than the first metal. In some cases, to reduce capacitance inside a transistor gate trench, techniques can be performed to form low-k dielectric material on the gate trench sidewalls.

The present invention provides a method for forming a semiconductor structure, including the following steps: first, a substrate is provided, an interlayer dielectric (ILD) is formed on the substrate, a first dummy gate is formed in the ILD, wherein the first dummy gate includes a dummy gate electrode and two spacers disposed on two sides of the dummy gate electrode respectively. Next, two contact holes are formed in the ILD at two sides of the first dummy gate respectively. Afterwards, the dummy gate electrode is removed, so as to form a gate recess in the ILD, a first material layer is filled in the gate recess and a second material layer is filled in the two contact holes respectively, and an anneal process is performed on the first material layer and the second material layer, to bend the two spacers into two inward curving spacers.

An integrated circuit and method includes self-aligned contacts. A gapfill dielectric layer fills spaces between sidewalls of adjacent MOS gates. The gapfill dielectric layer is planarized down to tops of gate structures. A contact pattern is formed that exposes an area for multiple self-aligned contacts. The area overlaps adjacent instances of the gate structures. The gapfill dielectric layer is removed from the area. A contact metal layer is formed in the areas where the gapfill dielectric material has been removed. The contact metal abuts the sidewalls along the height of the sidewalls. The contact metal is planarized down to the tops of the gate structures, forming the self-aligned contacts.

The present invention provides a method for forming a semiconductor structure, including the following steps: first, a substrate is provided, an interlayer dielectric (ILD) is formed on the substrate, a first dummy gate is formed in the ILD, wherein the first dummy gate includes a dummy gate electrode and two spacers disposed on two sides of the dummy gate electrode respectively. Next, two contact holes are formed in the ILD at two sides of the first dummy gate respectively. Afterwards, the dummy gate electrode is removed, so as to form a gate recess in the ILD, a first material layer is filled in the gate recess and a second material layer is filled in the two contact holes respectively, and an anneal process is performed on the first material layer and the second material layer, to bend the two spacers into two inward curving spacers.