A method for controlling Schottky barrier height in a semiconductor device includes forming an alloy layer including at least a first element and a second element on a first surface of a semiconductor substrate. The semiconductor substrate is a first element-based semiconductor substrate, and the first element and the second element are Group IV elements. A first thermal anneal of the alloy layer and the first element-based substrate is performed. The first thermal anneal causes the second element in the alloy layer to migrate towards a surface of the alloy layer. A Schottky contact layer is formed on the alloy layer after the first thermal anneal.

A first dielectric layer is selectively formed such that the first dielectric layer is formed over a source/drain region of a first type of transistor but not over a source/drain region of a second type of transistor. The first type of transistor and the second type of transistor have different types of conductivity. A first silicide layer is selectively formed such that the first silicide layer is formed over the source/drain region of the second type of transistor but not over the source/drain region of the first type of transistor. The first dielectric layer is removed. A second silicide layer is formed over the source/drain region of the first type of transistor.

Provided is a memory device including a substrate, a plurality of contacts, and a plurality of air gaps. The substrate has a plurality of active areas. The contacts are respectively disposed on ends of the active areas. The air gaps respectively surround the sidewalls of the contacts.

In an embodiment, a method includes: depositing a gate dielectric layer on a first fin and a second fin, the first fin and the second fin extending away from a substrate in a first direction, a distance between the first fin and the second fin decreasing along the first direction; depositing a sacrificial layer on the gate dielectric layer by exposing the gate dielectric layer to a self-limiting source precursor and a self-reacting source precursor, the self-limiting source precursor reacting to form an initial layer of a material of the sacrificial layer, the self-reacting source precursor reacting to form a main layer of the material of the sacrificial layer; annealing the gate dielectric layer while the sacrificial layer covers the gate dielectric layer; after annealing the gate dielectric layer, removing the sacrificial layer; and after removing the sacrificial layer, forming a gate electrode layer on the gate dielectric layer.

A method for controlling Schottky barrier height in a semiconductor device includes forming an alloy layer including at least a first element and a second element on a first surface of a semiconductor substrate. The semiconductor substrate is a first element-based semiconductor substrate, and the first element and the second element are Group IV elements. A first thermal anneal of the alloy layer and the first element-based substrate is performed. The first thermal anneal causes the second element in the alloy layer to migrate towards a surface of the alloy layer. A Schottky contact layer is formed on the alloy layer after the first thermal anneal.

Techniques are disclosed for forming transistor devices having reduced parasitic contact resistance relative to conventional devices. The techniques can be implemented, for example, using a standard contact stack such as a series of metals on, for example, silicon or silicon germanium (SiGe) source/drain regions. In accordance with one example such embodiment, an intermediate boron doped germanium layer is provided between the source/drain and contact metals to significantly reduce contact resistance. Numerous transistor configurations and suitable fabrication processes will be apparent in light of this disclosure, including both planar and non-planar transistor structures (e.g., FinFETs), as well as strained and unstrained channel structures. Graded buffering can be used to reduce misfit dislocation. The techniques are particularly well-suited for implementing p-type devices, but can be used for n-type devices if so desired.

A semiconductor device is provided. The semiconductor device includes: an active region on a semiconductor substrate; a channel region on the active region; a source/drain region adjacent to the channel region on the active region; a gate structure overlapping the channel region, on the channel region; a contact structure on the source/drain region; a gate spacer between the contact structure and the gate structure; and a contact spacer surrounding a side surface of the contact structure. The source/drain region includes a first epitaxial region having a recessed surface and a second epitaxial region on the recessed surface of the first epitaxial region, and the second epitaxial region includes an extended portion, extended from a portion overlapping the contact structure in a vertical direction, in a horizontal direction and overlapping the contact spacer in the vertical direction.

A device includes an active region, a gate structure, a source/drain epitaxial structure, an epitaxial layer, a metal alloy layer, a contact, and a contact etch stop layer. The gate structure is across the active region. The source/drain epitaxial structure is over the active region and adjacent the gate structure. The epitaxial layer is over the source/drain epitaxial structure. The metal alloy layer is over the epitaxial layer. The contact is over the metal alloy layer. The contact etch stop layer lines sidewalls of the source/drain epitaxial structure. The metal alloy layer is spaced apart from the contact etch stop layer.

A vertical semiconductor device may include a semiconductor substrate having at least one trench therein, and a superlattice layer extending vertically adjacent the at least one trench. The superlattice layer may comprise stacked groups of layers, with each group of layers comprising stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer. Each at least one non-semiconductor monolayer of each group of layers may be constrained within a crystal lattice of adjacent base semiconductor portions. The vertical semiconductor device may also include a doped semiconductor layer adjacent the superlattice layer, and a conductive body adjacent the doped semiconductor layer on a side thereof opposite the superlattice layer and defining a vertical semiconductor device contact.

A three-dimensional (3D) semiconductor memory device includes a source structure disposed on a horizontal semiconductor layer and including a first source conductive pattern and a second source conductive pattern which are sequentially stacked on the horizontal semiconductor layer, an electrode structure including a plurality of electrodes vertically stacked on the source structure, and a vertical semiconductor pattern penetrating the electrode structure and the source structure, wherein a portion of a sidewall of the vertical semiconductor pattern is in contact with the source structure. The first source conductive pattern includes a discontinuous interface at a level between a top surface of the horizontal semiconductor layer and a bottom surface of the second source conductive pattern.