The present disclosure describes a semiconductor device that includes nanostructures on a substrate and a source/drain region in contact with the nanostructures. The source/drain region includes (i) a first epitaxial structure embedded in the substrate; (ii) a nitride layer on the first epitaxial structure; and a second epitaxial structure on the first epitaxial structure. The semiconductor device also includes a gate structure formed on the nanostructures.

Embodiments of the disclosure provide an improved apparatus and methods for nitridation of stacks of materials. In one embodiment, a method for processing a substrate in a processing region of a process chamber is provided. The method includes generating and flowing plasma species from a remote plasma source to a delivery member having a longitudinal passageway, flowing plasma species from the longitudinal passageway to an inlet port formed in a sidewall of the process chamber, wherein the plasma species are flowed at an angle into the inlet port to promote collision of ions or reaction of ions with electrons or charged particles in the plasma species such that ions are substantially eliminated from the plasma species before entering the processing region of the process chamber, and selectively incorporating atomic radicals from the plasma species in silicon or polysilicon regions of the substrate.

A method for forming a semiconductor device structure is provided. The semiconductor device includes forming nanowire structures stacked over a substrate and spaced apart from one another, and forming a dielectric material surrounding the nanowire structures. The dielectric material has a first nitrogen concentration. The method also includes treating the dielectric material to form a treated portion. The treated portion of the dielectric material has a second nitrogen concentration that is greater than the first nitrogen concentration. The method also includes removing the treating portion of the dielectric material, thereby remaining an untreated portion of the dielectric material as inner spacer layers; and forming the gate stack surrounding nanowire structures and between the inner spacer layers.

Methods and apparatuses for processing substrates, such as during metal silicide applications, are provided. In one or more embodiments, a method of processing a substrate includes depositing an epitaxial layer on the substrate, depositing a metal silicide seed layer on the epitaxial layer, and exposing the metal silicide seed layer to a nitridation process to produce a metal silicide nitride layer from at least a portion of the metal silicide seed layer. The method also includes depositing a metal silicide bulk layer on the metal silicide nitride layer and forming or depositing a nitride capping layer on the metal silicide bulk layer, where the nitride capping layer contains a metal nitride, a silicon nitride, a metal silicide nitride, or a combination thereof.

Exemplary processing methods may include forming a plasma of a silicon-containing precursor. The methods may include depositing a flowable film on a semiconductor substrate with plasma effluents of the silicon-containing precursor. The semiconductor substrate may define a feature within the semiconductor substrate. The methods may include forming a plasma of a hydrogen-containing precursor within the processing region of the semiconductor processing chamber. A bias power may be applied to the substrate support from a bias power source. The methods may include etching the flowable film from a sidewall of the feature within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor. The methods may include densifying remaining flowable film within the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor.

A semiconductor device structure is provided. The semiconductor device includes a first nanowire structure over a second nanowire structure, a gate stack wrapping around the first nanowire structure and the second nanowire structure, a source/drain feature adjoining the first nanowire structure and the second nanowire structure, a gate spacer layer over the first nanowire structure and between the gate stack and the source/drain feature, and an inner spacer layer between the first nanowire structure and the second nanowire structure and between the gate stack and the source/drain feature. The gate spacer layer has a first carbon concentration, the inner spacer has a second carbon concentration, and the second carbon concentration is lower than the first carbon concentration.

Exemplary processing methods may include forming a plasma of a silicon-containing precursor. The methods may include depositing a flowable film on a semiconductor substrate with plasma effluents of the silicon-containing precursor. The processing region may be at least partially defined between a faceplate and a substrate support on which the semiconductor substrate is seated. A bias power may be applied to the substrate support from a bias power source. The methods may include forming a plasma of a hydrogen-containing precursor within the processing region of the semiconductor processing chamber. The methods may include etching the flowable film from a sidewall of the feature within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor. The methods may include densifying remaining flowable film within the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor.

A semiconductor device having a gate structure and a method of forming same are provided. The semiconductor device includes a substrate and a gate structure over the substrate. The substrate has a first region and a second region. The gate structure extends across an interface between the first region and the second region. The gate structure includes a first gate dielectric layer over the first region, a second gate dielectric layer over the second region, a first work function layer over the first gate dielectric layer, a barrier layer along a sidewall of the first work function layer and above the interface between the first region and the second region, and a second work function layer over the first work function layer, the barrier layer and the second gate dielectric layer. The second work function layer is in physical contact with a top surface of the first work function layer.

A method for manufacturing a semiconductor includes: providing a substrate; forming a polysilicon layer on the substrate, a surface, away from the substrate, of the polysilicon layer having a native oxide; and performing a nitriding treatment to the native oxide, to nitrogenize the native oxide into a silicon oxynitride layer. The native oxide is nitrogenized into the silicon oxynitride layer.

Generally, examples described herein relate to methods and processing systems for forming isolation structures (e.g., shallow trench isolations (STIs)) between fins on a substrate. In an example, fins are formed on a substrate. A liner layer is conformally formed on and between the fins. Forming the liner layer includes conformally depositing a pre-liner layer on and between the fins, and densifying, using a plasma treatment, the pre-liner layer to form the liner layer. A dielectric material is formed on the liner layer.