A semiconductor structure includes a metal gate structure disposed over a semiconductor substrate, an interlayer dielectric (ILD) layer disposed over the metal gate structure, and a gate contact disposed in the ILD layer and over the metal gate structure, where a bottom surface of the gate contact is defined by a barrier layer disposed over the metal gate structure, where sidewall surfaces of the gate contact are defined by and directly in contact with the ILD layer, and where the barrier layer is free of nitrogen.

A method includes forming a gate stack over a first semiconductor region, removing a second portion of the first semiconductor region on a side of the gate stack to form a recess, growing a second semiconductor region starting from the recess, implanting the second semiconductor region with an impurity, and performing a melting laser anneal on the second semiconductor region. A first portion of the second semiconductor region is molten during the melting laser anneal, and a second and a third portion of the second semiconductor region on opposite sides of the first portion are un-molten.

A semiconductor device includes a first source/drain region and a second source/drain region disposed on opposite sides of a plurality of conductive layers. A dielectric layer overlies the first source/drain region, the second source/drain region, and the plurality of conductive layers. An electrical contact extends through the dielectric layer and the first source/drain region, where a first surface of the electrical contact is a surface of the electrical contact that is closest to the substrate, a first surface of the plurality of conductive layers is a surface of the plurality of conductive layers that is closest to the substrate, and the first surface of the electrical contact is closer to the substrate than the first surface of the plurality of conductive layers.

A semiconductor device according to an embodiment includes: a semiconductor substrate; a conductor including tungsten (W) or molybdenum (Mo); a first film provided between the conductor and the semiconductor substrate and including titanium (Ti) and silicon (Si); an insulating layer surrounding the conductor; and a second film provided between the conductor and the insulating layer, surrounding the conductor, and including titanium (Ti) and nitrogen (N). A first distance between the semiconductor substrate and an end portion of the second film on a side opposite to the semiconductor substrate is smaller than a second distance between the semiconductor substrate and an end portion of the conductor on a side opposite to the semiconductor substrate.

A method of preparing a self-aligned via on a semiconductor workpiece includes using an integrated sequence of processing steps executed on a common manufacturing platform hosting a plurality of processing modules including one or more film-forming modules, one or more etching modules, and one or more transfer modules. The integrated sequence of processing steps include receiving the workpiece into the common manufacturing platform, the workpiece having a pattern of metal features in a dielectric layer wherein exposed surfaces of the metal features and exposed surfaces of the dielectric layer together define an upper planar surface; selectively etching the metal features to form a recess pattern by recessing the exposed surfaces of the metal features beneath the exposed surfaces of the dielectric layer using one of the one or more etching modules; and depositing an etch stop layer over the recess pattern using one of the one or more film-forming modules.

Embodiments disclosed herein relate to using an implantation process and a melting anneal process performed on a nanosecond scale to achieve a high surface concentration (surface pile up) dopant profile and a retrograde dopant profile simultaneously. In an embodiment, a method includes forming a source/drain structure in an active area on a substrate, the source/drain structure including a first region comprising germanium, implanting a first dopant into the first region of the source/drain structure to form an amorphous region in at least the first region of the source/drain structure, implanting a second dopant into the amorphous region containing the first dopant, and heating the source/drain structure to liquidize and convert at least the amorphous region into a crystalline region, the crystalline region containing the first dopant and the second dopant.

A device includes a fin extending from a semiconductor substrate; a gate stack over the fin; a first spacer on a sidewall of the gate stack; a source/drain region in the fin adjacent the first spacer; an inter-layer dielectric layer (ILD) extending over the gate stack, the first spacer, and the source/drain region, the ILD having a first portion and a second portion, wherein the second portion of the ILD is closer to the gate stack than the first portion of the ILD; a contact plug extending through the ILD and contacting the source/drain region; a second spacer on a sidewall of the contact plug; and an air gap between the first spacer and the second spacer, wherein the first portion of the ILD extends across the air gap and physically contacts the second spacer, wherein the first portion of the ILD seals the air gap.

In an embodiment, a structure includes: a gate stack over a channel region of a substrate; a source/drain region adjacent the channel region; a first inter-layer dielectric (ILD) layer over the source/drain region; a silicide between the first ILD layer and the source/drain region, the silicide contacting a top surface of the source/drain region and a bottom surface of the source/drain region; and a first source/drain contact having a first portion and a second portion, the first portion of the first source/drain contact disposed between the silicide and the first ILD layer, the second portion of the first source/drain contact extending through the first ILD layer and contacting the silicide.

Methods for forming a semiconductor structure are described. The method includes cleaning a substrate to form a substrate surface substantially free of oxide, exposing the substrate surface to a first molybdenum precursor, and exposing the substrate surface to a reactant to selectively deposit a first molybdenum film on the substrate surface. The method may be performed in a processing chamber without breaking vacuum. The method may also include forming one or more of a cap layer and a liner and annealing the substrate. The method may also include depositing a second molybdenum film on the substrate surface.

A semiconductor structure is provided. The semiconductor structure includes an epitaxial structure over a semiconductor substrate. The semiconductor structure also includes a conductive feature over the semiconductor substrate. The conductive feature includes a high-k dielectric layer and a metal layer on the high-k dielectric layer, and a top surface of the metal layer is below a top surface of the high-k dielectric layer. The semiconductor structure further includes a metal-semiconductor compound layer formed on the epitaxial structure. In addition, the semiconductor structure includes a first metal contact structure formed on the top surface of the metal layer of the conductive feature. The semiconductor structure further includes a second metal contact structure formed on the metal-semiconductor compound layer.