Provided is a semiconductor device which includes: a 1.sup.st source/drain region connected to a 1.sup.st channel structure which is controlled by a 1.sup.st gate structure; a 2.sup.nd source/drain region, above the 1.sup.st source/drain region, connected to a 2.sup.nd channel structure which is controlled by a 2.sup.nd gate structure; and a middle isolation structure between the 1.sup.st gate structure and the 2.sup.nd gate structure, wherein the middle isolation structure comprises two or more vertically-stacked semiconductor layers.

A semiconductor fabrication method includes: forming an epitaxial stack including at least one sacrificial epitaxial layer and at least one channel epitaxial layer; forming a plurality of fins in the epitaxial stack; performing tuning operations to prevent a width of the sacrificial epitaxial layer expanding beyond a width of the channel epitaxial layer during operations to form isolation features; forming the isolation features between the plurality of fins, wherein the width of the sacrificial epitaxial layer does not expand beyond the width of the channel epitaxial layer; forming a sacrificial gate stack; forming gate sidewall spacers on sidewalls of the sacrificial gate stack; forming inner spacers around the sacrificial epitaxial layer and the channel epitaxial layer; forming source/drain features; removing the sacrificial gate stack and sacrificial epitaxial layer; and forming a replacement metal gate, wherein the metal gate is shielded from the source/drain features.

A method for forming a semiconductor structure is provided. The method includes forming a first nanostructure and a second nanostructure over a substrate, forming a first interfacial layer on the first nanostructure and a second interfacial layer on the second nanostructure, forming a first gate dielectric layer on the first interfacial layer and a second gate dielectric layer on the second interfacial layer, forming a patterned mask layer on the second gate dielectric layer while exposing the first gate dielectric layer, and driving nitrogen into the first interfacial layer, thereby forming a nitrogen-doped interfacial layer.

A method includes: forming a stack of semiconductor nanostructures on a semiconductor fin; forming a source/drain opening adjacent the stack; forming a bottom dielectric layer on the semiconductor fin; forming a source/drain region in the source/drain opening, a void being present between the source/drain region and the bottom dielectric layer; forming a dielectric layer on the source/drain region; forming a hardened portion of the dielectric layer by treating the dielectric layer, the hardened portion having higher etch selectivity than other portions of the dielectric layer; removing the other portions of the dielectric layer, exposing the void; forming a source/drain contact opening that extends to and connects with the void, the source/drain contact opening exposing sidewalls of the source/drain region; forming a liner layer on exposed surfaces of the source/drain region; and forming a conductive core layer on the liner layer, the conductive core layer being in contact with the liner layer on a top surface, sidewalls and a bottom surface of the source/drain region.

A semiconductor device includes a first active pattern extending in a first direction, a second active pattern on the first active pattern and extending in the first direction, a gate structure on the first active pattern and the second active pattern and extending in a second direction intersecting the first direction, a first source/drain region on side faces of the gate structure and connected to the first active pattern, a second source/drain region on the side faces of the gate structure and connected to the second active pattern, and an intermediate connecting layer which includes a first intermediate conductive pattern between the first active pattern and the second active pattern, and a second intermediate conductive pattern connected to the first intermediate conductive pattern between the first source/drain region and the second source/drain region.

A method of forming a semiconductor structure includes forming an opening in a dielectric layer, forming a recess in an exposed part of a substrate, and forming a lattice-mismatched crystalline semiconductor material in the recess and opening.

An apparatus including a complimentary metal oxide semiconductor (CMOS) inverter including an n-channel metal oxide semiconductor field effect transistor (MOSFET); and a p-channel MOSFET, wherein a material of a channel in the n-channel MOSFET and a material of a channel in the p-channel MOSFET is subject to a bi-axial tensile strain. A method including forming an n-channel metal oxide semiconductor field effect transistor (MOSFET); forming a p-channel MOSFET; and connecting the gate electrodes and the drain regions of the n-channel MOSFET and the p-channel MOSFET, wherein a material of the channel in the n-channel MOSFET and a material of the channel in the p-channel MOSFET is subject to a bi-axial tensile strain.

A semiconductor device is provided that includes an n-type field effect transistor including a plurality of vertically stacked silicon-containing nanowires located in one region of a semiconductor substrate, and a p-type field effect transistor including a plurality of vertically stacked silicon germanium alloy nanowires located in another region of a semiconductor substrate. Each vertically stacked silicon-containing nanowire of the n-type field effect transistor has a different shape than the shape of each vertically stacked silicon germanium alloy nanowire of the p-type field effect transistor.

Techniques are disclosed for improved integration of germanium (Ge)-rich p-MOS source/drain contacts to, for example, reduce contact resistance. The techniques include depositing the p-type Ge-rich layer directly on a silicon (Si) surface in the contact trench location, because Si surfaces are favorable for deposition of high quality conductive Ge-rich materials. In one example method, the Ge-rich layer is deposited on a surface of the Si substrate in the source/drain contact trench locations, after removing a sacrificial silicon germanium (SiGe) layer previously deposited in the source/drain locations. In another example method, the Ge-rich layer is deposited on a Si cladding layer in the contact trench locations, where the Si cladding layer is deposited on a functional p-type SiGe layer. In some cases, the Ge-rich layer comprises at least 50% Ge (and may contain tin (Sn) and/or Si) and is boron (B) doped at levels above 1E20 cm.sup.3.

A technique for forming a semiconductor device is provided. Sacrificial mandrels are formed over a hardmask layer on a semiconductor layer. Spacers are formed on sidewalls of the sacrificial mandrels. The sacrificial mandrels are removed to leave the spacers. A masking process leaves exposed a first set of spacers with a second set protected. In response to the masking process, a first fin etch process forms a first set of fins in the semiconductor layer via first set of spacers. The first set of fins has a vertical sidewall profile. Another masking process leaves exposed the second set of spacers with the first set of spacers and the first set of fins protected. In response to the other masking process, a second fin etch process forms a second set of fins in semiconductor layer using the second set of spacers. The second set of fins has a trapezoidal sidewall profile.