Semiconductor devices having vertical FET (field effect transistor) devices with metallic source/drain regions are provided, as well as methods for fabricating such vertical FET devices. For example, a semiconductor device includes a first source/drain region formed on a semiconductor substrate, a vertical semiconductor fin formed on the first source/drain region, a second source/drain region formed on an upper surface of the vertical semiconductor fin, a gate structure formed on a sidewall surface of the vertical semiconductor fin, and an insulating material that encapsulates the vertical semiconductor fin and the gate structure. The first source/drain region comprises a metallic layer and at least a first epitaxial semiconductor layer. For example, the metallic layer of the first source/drain region comprises a metal-semiconductor alloy such as silicide.

Aspects of the disclosure include a semiconductor structure that includes a vertical fin structure having a top portion, a bottom portion, vertical side walls, a source area in contact with the vertical fin structure, a drain area in contact with the vertical fin structure, a plurality of spacers comprising a first oxide layer in contact with the source area, and a second oxide layer in contact with the drain area. The first oxide layer can have a thickness that is equal to a thickness of the second oxide layer.

A method for forming a hybrid semiconductor device includes growing a stack of layers on a semiconductor substrate. The stack of layers includes a bottom layer in contact with the substrate, a middle layer on the bottom layer and a top layer on the middle layer. First and second transistors are formed on the top layer. A protective dielectric is deposited over the first and second transistors. A trench is formed adjacent to the first transistors to expose the middle layer. The middle layer is removed from below the first transistors to form a cavity. A dielectric material is deposited in the cavity to provide a transistor on insulator structure for the first transistors and a bulk substrate structure for the second transistors.

Some embodiments include a transistor having a drain region and a source region. A conductive gate is between the source and drain regions. First channel material is between the gate and the source region. The first channel material is spaced from the gate by one or more insulative materials. Second channel material is between the first channel material and the source region, and directly contacts the source region. The first and second channel materials are transition metal chalcogenide. One of the source and drain regions is a hole reservoir region and the other is an electron reservoir region. Tunnel dielectric material may be between the first and second channel materials.

Techniques relate to a gate stack for a semiconductor device. A vertical fin is formed on a substrate. The vertical fin has an upper portion and a bottom portion. The upper portion of the vertical fin has a recessed portion on sides of the upper portion. A gate stack is formed in the recessed portion of the upper portion of the vertical fin.

A method of forming a vertical fin field effect transistor (vertical finFET) with an increased surface area between a source/drain contact and a doped region, including forming a doped region on a substrate, forming one or more interfacial features on the doped region, and forming a source/drain contact on at least a portion of the doped region, wherein the one or more interfacial features increases the surface area of the interface between the source/drain contact and the doped region compared to a flat source/drain contact-doped region interface.

A vertical fin field-effect-transistor and a method for fabricating the same. The vertical fin field-effect-transistor includes at least a substrate, a first source/drain layer, and a plurality of fins each disposed on and in contact with the first source/drain layer. Silicide regions are disposed within a portion of the first source/drain layer. A gate structure is in contact with the plurality of fins, and a second source/drain layer is disposed on the gate structure. The method includes forming silicide in a portion of a first source/drain layer. A first spacer layer is formed in contact with at least the silicide, the first source/drain layer and the plurality of fins. A gate structure is formed in contact with the plurality of fins and the first spacer layer. A second spacer layer is formed in contact with the gate structure and the plurality of fins.

The present description relates to the field of fabricating microelectronic devices having non-planar transistors. Embodiments of the present description relate to the formation of source/drain contacts within non-planar transistors, wherein a titanium-containing contact interface may be used in the formation of the source/drain contact with a discreet titanium silicide formed between the titanium-containing interface and a silicon-containing source/drain structure.

A vacuum channel transistor having a vertical gate-all-around (GAA) architecture provides high performance for high-frequency applications, and features a small footprint compared with existing planar devices. The GAA vacuum channel transistor features stacked, tapered source and drain regions that are formed by notching a doped silicon pillar using a lateral oxidation process. A temporary support structure is provided for the pillar during formation of the vacuum channel. Performance of the GAA vacuum channel transistor can be tuned by replacing air in the channel with other gases such as helium, neon, or argon. A threshold voltage of the GAA vacuum channel transistor can be adjusted by altering dopant concentrations of the silicon pillar from which the source and drain regions are formed.

Floating gate memory cells in vertical memory. A control gate is formed between a first tier of dielectric material and a second tier of dielectric material. A floating gate is formed between the first tier of dielectric material and the second tier of dielectric material, wherein the floating gate includes a protrusion extending towards the control gate. A charge blocking structure is formed between the floating gate and the control gate, wherein at least a portion of the charge blocking structure wraps around the protrusion.