A vertical transistor has a first air-gap spacer between a gate and a bottom source/drain region, and a second air-gap spacer between the gate and the contact to the bottom source/drain region. A dielectric layer disposed between the gate and the contact to the top source/drain decreases parasitic capacitance and inhibits electrical shorting.

A Tunnel Field-Effect Transistor (TFET) is provided comprising a source-channel-drain structure of a semiconducting material. The source-channel-drain structure comprises a source region being n-type or p-type doped, a drain region oppositely doped than the source region and an intrinsic or lowly doped channel region situated between the source region and the drain region. The TFET further comprises a reference gate structure covering the channel region and a source-side gate structure aside of the reference gate structure wherein the work function and/or electrostatic potential of the source-side gate structure and the reference work function and/or electrostatic potential of the reference gate structure are selected for allowing the tunneling mechanism of the TFET device in operation to occur at the interface or interface region between the source-side gate structure and the reference gate structure in the channel region.

A semiconductor structure includes a substrate, at least one first gate structure, at least one first spacer, at least one source drain structure, and a conductive plug. The first gate structure is present on the substrate. The first spacer is present on at least one sidewall of the first gate structure. The source drain structure is present adjacent to the first spacer. The conductive plug is electrically connected to the source drain structure while leaving a gap between the conductive plug and the spacer.

A semiconductor structure includes a substrate, at least one first gate structure, at least one source drain structure, at least one bottom conductor, and a first dielectric layer. The first gate structure is present on the substrate. The source drain structure is present on the substrate. The bottom conductor is electrically connected to the source drain structure. The bottom conductor has an upper portion and a lower portion between the upper portion and the source drain structure, and a gap is at least present between the upper portion of the bottom conductor and the first gate structure. The first dielectric layer is at least present between the lower portion of the bottom conductor and the first gate structure.

Devices and methods of fabricating integrated circuit devices for increasing performance through gate cut last processes are provided. One method includes, for instance: obtaining an intermediate semiconductor device having a substrate including a plurality of fins, an STI layer, an oxide layer, and a gate material over the oxide layer, the fins extending into the gate material; removing the gate material and the oxide layer; depositing a high k material on a top surface of the STI layer, surrounding the fins; depositing a gate stack over the high k material; filling the top of the device with a gate contact metal; etching a portion of the gate contact metal, the metal gate stack, and the high k material; and filling the portion with an inter-layer dielectric. Also disclosed is an intermediate device formed by the method.

Semiconductor devices with airgap spacers and methods of forming the same include forming a lower spacer that defines a gate region. A sacrificial upper spacer is formed directly above the lower spacer. A gate stack is formed in the gate region. The sacrificial upper spacer is etched away to form an upper spacer opening. An airgap spacer is formed in the upper spacer opening. The airgap spacer includes a dielectric material that encapsulates an internal void.

A semiconductor structure includes a semiconductor substrate having a gate electrode in a gate trench, a buried bus in the semiconductor substrate, the buried bus having a bus conductive filler in a bus trench, where the bus conductive filler is electrically coupled to the gate electrode. The bus conductive filler is surrounded by the gate electrode. The gate trench intersects the bus trench in the semiconductor substrate. The gate electrode includes polysilicon. The bus conductive filler includes tungsten. The semiconductor structure also includes an adhesion promotion layer interposed between the bus conductive filler and the gate electrode, where the adhesion promotion layer includes titanium and titanium nitride. The semiconductor structure also includes a dielectric layer covering the gate electrode over the semiconductor substrate, where the buried bus has a coplanar top surface with the dielectric layer.

A method of forming a semiconductor structure includes forming a first middle-of-line (MOL) oxide layer and a second MOL oxide layer in the semiconductor structure. The first MOL oxide layer including multiple gate stacks formed on a substrate, and each gate stack of the gate stacks including a source/drain junction. A first nitride layer is formed over a silicide in the first MOL oxide layer. A second nitride layer is formed. Trenches are formed through the second nitride layer down to the source/drain junctions. A nitride cap of the plurality of gate stacks is selectively recessed. At least one self-aligned contact area (CA) element is formed within the first nitride layer. The first MOL oxide layer is selectively recessed. An air-gap oxide layer is deposited. The air gap oxide layer is reduced to the at least one self-aligned CA element and the first nitride layer.

Solid assemblies having a composite dielectric spacer and processes for fabricating the solid assemblies are provided. The composite dielectric spacer can include, in some embodiments, a first dielectric layer and a second dielectric layer having a mutual interface. The composite dielectric spacer can separate a contact member from a conductive interconnect member, thus reducing the capacitance between such members with respect to solid assemblies that include one of first dielectric layer or the second dielectric layer. The composite dielectric spacer can permit maintaining the real estate of an interface between the conductive interconnect and a trench contact member that has an interface with a carrier-doped epitaxial layer embodying or constituting a source contact region or a drain contact region of a field effect transistor. The trench contact member can form another interface with the conductive interconnect member, providing a satisfactory contact resistance therebetween.

Semiconductor devices having air gap spacers that are formed as part of BEOL or MOL layers of the semiconductor devices are provided, as well as methods for fabricating such air gap spacers. For example, a method comprises forming a first metallic structure and a second metallic structure on a substrate, wherein the first and second metallic structures are disposed adjacent to each other with insulating material disposed between the first and second metallic structures. The insulating material is etched to form a space between the first and second metallic structures. A layer of dielectric material is deposited over the first and second metallic structures using a pinch-off deposition process to form an air gap in the space between the first and second metallic structures, wherein a portion of the air gap extends above an upper surface of at least one of the first metallic structure and the second metallic structure.