A method for fabricating semiconductor device includes the steps of first forming a gate structure on a substrate, forming a source/drain region adjacent to two sides of the gate structure, forming an epitaxial layer on the source/drain region, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer to expose the epitaxial layer, forming a low stress metal layer in the contact hole, forming a barrier layer on the low stress metal layer, and forming an anneal process to form a first silicide layer and a second silicide layer.

An inner sidewall spacer is formed before the formation of the epitaxial source/drain features and an outer sidewall spacer is formed after the epitaxial source/drain features. The two-level sidewall spacer design increases volume of the epitaxial source/drain features, thus improving ion performance. The thicker sidewall spacers also reduce capacitance between source/drain contacts and the gate electrode. In some embodiments, semiconductor nanosheets may be etched to reduce thickness prior to forming replacement gate structures. Nanosheets with reduced thickness improve device swing performance, reduce DIBL effect without sacrificing the channel resistance and epitaxial growth margin.

A substrate having a recess, a diffusion barrier layer defining the recess, and a wiring exposed at a bottom of the recess is prepared. A metal ion, having a concentration not causing precipitation of a metal even when an electroless plating liquid comes into contact therewith, is attached to the diffusion barrier layer. The metal is precipitated in the recess by supplying the electroless plating liquid into the recess in a state that the metal ion is attached to the diffusion barrier layer.

A method for fabricating a static random access memory (SRAM) includes the steps of: forming a gate structure on a substrate; forming an epitaxial layer adjacent to the gate structure; forming a first interlayer dielectric (ILD) layer around the gate structure; transforming the gate structure into a metal gate; forming a contact hole exposing the epitaxial layer, forming a barrier layer in the contact hole, forming a metal layer on the barrier layer, and then planarizing the metal layer and the barrier layer to form a contact plug. Preferably, a bottom portion of the barrier layer includes a titanium rich portion and a top portion of the barrier layer includes a nitrogen rich portion.

A semiconductor device and a method of making the same are provided. A method according to the present disclosure includes forming a first type epitaxial layer over a second type source/drain feature of a second type transistor, forming a second type epitaxial layer over a first type source/drain feature of a first type transistor, selectively depositing a first metal over the first type epitaxial layer to form a first metal layer while the first metal is substantially not deposited over the second type epitaxial layer over the first type source/drain feature, and depositing a second metal over the first metal layer and the second type epitaxial layer to form a second metal layer.

A semiconductor device is disclosed. The semiconductor device includes a gate electrode on a substrate and extending in a first direction, source/drain patterns spaced apart from each other, in a second direction, with the gate electrode interposed therebetween, a gate contact electrically connected to the gate electrode, and an active contact electrically connected to at least one of the source/drain patterns. The active contact includes a lower contact pattern electrically connected to the at least one of the source/drain patterns, the lower contact pattern having a first width in the first direction, and an upper contact pattern electrically connected to a top surface of the lower contact pattern, the upper contact pattern having a second width in the first direction that is smaller than the first width. The upper contact pattern and the gate contact horizontally overlap each other.

An integrated circuit device includes a fin-type active area that extends on a substrate in a first direction, a gate structure that extends on the substrate in a second direction and crosses the fin-type active area, source/drain areas arranged on first and second sides of the gate structure, and a contact structure electrically connected to the source/drain areas. The source/drain areas comprise a plurality of merged source/drain structures. Each source/drain area comprises a plurality of first points respectively located on an upper surface of the source/drain area at a center of each source/drain structure, and each source/drain area comprises at least one second point respectively located on the upper surface of the source/drain area where side surfaces of adjacent source/drain structures merge with one another. A bottom surface of the contact structure is non-uniform and corresponds to the first and second points.

The present disclosure provides an interconnect structure and a method for forming an interconnect structure. The method for forming an interconnect structure includes forming a first interlayer dielectric (ILD) layer over a substrate, forming a contact in the first ILD layer, forming a second ILD layer over the first ILD layer, forming a first opening in the second ILD layer and obtaining an exposed side surface of the second ILD layer over the contact, forming a densified dielectric layer at the exposed side surface of the second ILD layer, including oxidizing the exposed side surface of the second ILD layer by irradiating a microwave on the second ILD layer, and forming a via in contact with the densified dielectric layer.

Embodiments disclosed herein generally relate to methods of depositing a plurality of layers. A doped copper seed layer is deposited in a plurality of feature definitions in a device structure. A first copper seed layer is deposited and then the first copper seed layer is doped to form a doped copper seed layer, or a doped copper seed layer is deposited directly. The doped copper seed layer leads to increased flowability, reducing poor step coverage, overhang, and voids in the copper layer.

Embodiments of the present application relate to a method for manufacturing a semiconductor structure, includes: forming a contact metal layer on a silicon substrate; performing a plasma treatment process, and forming an oxygen isolation layer on a surface of the contact metal layer; and performing a silicidation reaction process, and converting the contact metal layer into a metal silicide layer.