Disclosed is a semiconductor device comprising: a substrate; a vertical active region formed on the substrate and comprising a first source/drain region, a channel region, and a second source/drain region sequentially disposed in a vertical direction, the first source/drain region including a laterally extending portion extending beyond a portion of the active region above the laterally extending portion; a gate stack formed around the periphery of the channel region, the gate stack including a laterally extending portion; and a stack contact portion from above the laterally extending portion of the first source/drain region to the laterally extending portion of the first source/drain region. The stack contact portion comprises a three-layer structure sequentially disposed in the vertical direction: a lower layer portion, a middle layer portion, and an upper layer portion. The lower layer portion contains at least the same element as the first source/drain region, the middle layer portion contains at least the same element as the channel region, and the upper layer portion contains at least the same element as the second source/drain region.

A method and system for doping semiconductor materials using microwave exposure. In some embodiments, the surface of a semiconductor substrate coated with a layer of dopant material is exposed to a beam of microwave radiation, with the frequency of the microwave radiation chosen to coincide with a microwave absorption resonance of the dopant. A gyrotron is a preferred source of monochromatic microwaves capable of delivering the appropriate the power density. Under this microwave exposure, the dopant heats up and diffuses into the semiconductor. Since only the dopant is selectively excited, the atoms of the crystal lattice remain cooler. Additional cooling can be provided by a flow of cooling gas onto the surface. When the electric field of the microwave exposure is high enough to overcome the potential barrier of interstitial diffusion within the crystal, the dopants migrate to vacancies in the crystal lattice, and the semiconductor material becomes activated.

A semiconductor device includes a substrate and a fin feature over the substrate. The fin feature includes a first portion of a first semiconductor material and a second portion of a second semiconductor material disposed over the first portion. The second semiconductor material is different from the first semiconductor material. The semiconductor device further includes a semiconductor oxide feature disposed on sidewalls of the first portion and a gate stack disposed on the fin feature. The gate stack includes an interfacial layer over a top surface and sidewalls of the second portion and a gate dielectric layer over the interfacial layer and sidewalls of the semiconductor oxide feature. A portion of the gate dielectric layer is below the interfacial layer.

A method for forming a semiconductor device comprises receiving a structure having a substrate, an isolation structure over the substrate, and a fin over the substrate and adjacent to the isolation structure. The method further includes etching a portion of the fin, resulting in a trench, forming a doped material layer over bottom and sidewalls of the trench, and growing at least one epitaxial layer over the doped material layer in the trench. The method further includes recessing the isolation structure and the doped material layer, leaving a first portion of the at least one epitaxial layer surrounded by the doped material layer and performing an annealing process, thereby driving dopants from the doped material layer into the first portion.

An embodiment method includes: forming a semiconductor liner layer on exposed surfaces of a fin structure that extends above a dielectric isolation structure disposed over a substrate; forming a first capping layer to laterally surround a bottom portion of the semiconductor liner layer; forming a second capping layer over an upper portion of the semiconductor liner layer; and annealing the fin structure having the semiconductor liner layer, the first capping layer, and the second capping layer thereon, the annealing driving a dopant from the semiconductor liner layer into the fin structure, wherein a dopant concentration profile in a bottom portion of the fin structure is different from a dopant concentration profile in an upper portion of the fin structure.

Embodiments of the present disclosure may generally relate to systems, apparatus, and/or processes to form volumes of oxide within a fin, such as a Si fin. In embodiments, this may be accomplished by applying a catalytic oxidant material on a side of a fin and then annealing to form a volume of oxide. In embodiments, this may be accomplished by using a plasma implant technique or a beam-line implant technique to introduce oxygen ions into an area of the fin and then annealing to form a volume of oxide. Processes described here may be used manufacture a transistor, a stacked transistor, or a three-dimensional (3-D) monolithic stacked transistor.

A semiconductor device includes a silicon substrate; a semiconductor fin over the silicon substrate; and an isolation structure over the silicon substrate. The semiconductor fin includes a first portion and a second portion over the first portion. The first portion is surrounded by the isolation structure, and the second portion protrudes above the isolation structure. The second portion has a different crystalline lattice constant than the first portion. The first portion includes a first dopant, and the second portion is substantially free of the first dopant. The semiconductor device further includes a gate structure above the isolation structure and engaging multiple surfaces of the second portion.

A method of selectively and conformally doping semiconductor materials is disclosed. Some embodiments utilize a conformal dopant film deposited selectively on semiconductor materials by thermal decomposition. Some embodiments relate to doping non-line of sight surfaces. Some embodiments relate to methods for forming a highly doped crystalline semiconductor layer.

A semiconductor device includes a substrate and a fin feature over the substrate. The fin feature includes a first portion of a first semiconductor material and a second portion of a second semiconductor material disposed over the first portion. The second semiconductor material is different from the first semiconductor material. The semiconductor device further includes a semiconductor oxide feature disposed on sidewalls of the first portion and a gate stack disposed on the fin feature. The gate stack includes an interfacial layer over a top surface and sidewalls of the second portion and a gate dielectric layer over the interfacial layer and sidewalls of the semiconductor oxide feature. A portion of the gate dielectric layer is below the interfacial layer.

A semiconductor device includes: a substrate having a first region and a second region; a first fin-shaped structure on the first region and a second fin-shaped structure on the second region, wherein each of the first fin-shaped structure and the second fin-shaped structure comprises a top portion and a bottom portion; a first doped layer around the bottom portion of the first fin-shaped structure; a second doped layer around the bottom portion of the second fin-shaped structure; a first liner on the first doped layer; and a second liner on the second doped layer.