A method for making a semiconductor device may include forming a semiconductor substrate, and forming a superlattice layer on the semiconductor substrate and including a plurality of stacked groups of layers. Each group of layers may including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may also include forming a Group III-N semiconductor stack comprising a plurality of layers of Group III-N semiconductor layers above the superlattice layer.

A device includes a first channel layer, a second channel layer, a gate structure, a source/drain epitaxial structure, and a source/drain contact. The first channel layer and the second channel layer are arranged above the first channel layer in a spaced apart manner over a substrate. The gate structure surrounds the first and second channel layers. The source/drain epitaxial structure is connected to the first and second channel layers. The source/drain contact is connected to the source/drain epitaxial structure. The second channel layer is closer to the source/drain contact than the first channel layer is to the source/drain contact, and the first channel layer is thicker than the second channel layer.

In an embodiment, a device includes: a first fin; a gate structure over the first fin; a first source/drain region adjacent the gate structure; an etch stop layer over the first source/drain region; a conductive line over the etch stop layer, the conductive line isolated from the first source/drain region by the etch stop layer, a top surface of the conductive line being coplanar with a top surface of the gate structure; and a power rail contact extending through the first fin, the power rail contact connected to the first source/drain region.

An integrated circuit includes a first time delay circuit, a second time delay circuit, and a master-slave flip-flop having a gated input circuit and a transmission gate. The transmission gate is configured to receive the first clock signal and the second clock signal to control a transmission state of the transmission gate. The gated input circuit is configured to have an input transmission state controlled by the third clock signal at the second output of the second time delay circuit. The second time delay circuit further includes a second gate-conductor and a second gate via-connector in direct contact with the second gate-conductor. The second gate-conductor intersects a first-type active region structure and a second-type active region structure in a second area, and wherein at least a portion of the second gate via-connector is atop the second-type active region structure.

An integrated circuit includes a first time delay circuit, a second time delay circuit, and a master-slave flip-flop having a gated input circuit and a transmission gate. The transmission gate is configured to receive the first clock signal and the second clock signal to control a transmission state of the transmission gate. The gated input circuit is configured to have an input transmission state controlled by the third clock signal at the second output of the second time delay circuit. The second time delay circuit further includes a second gate-conductor and a second gate via-connector in direct contact with the second gate-conductor. The second gate-conductor intersects a first-type active region structure and a second-type active region structure in a second area, and wherein at least a portion of the second gate via-connector is atop the second-type active region structure.

Semiconductor devices including air spacers formed in a backside interconnect structure and methods of forming the same are disclosed. In an embodiment, a device includes a first transistor structure; a front-side interconnect structure on a front-side of the first transistor structure; and a backside interconnect structure on a backside of the first transistor structure, the backside interconnect structure including a first dielectric layer on the backside of the first transistor structure; a first via extending through the first dielectric layer, the first via being electrically coupled to a first source/drain region of the first transistor structure; a first conductive line electrically coupled to the first via; and an air spacer adjacent the first conductive line, the first conductive line defining a first side boundary of the air spacer.

A method for making a semiconductor device may include forming a stack of alternating gate and nanostructure layers above a substrate, and forming a first superlattice laterally adjacent the stack on a first side thereof and extending from the substrate to an upper surface of the stack to define a first source/drain region. The first superlattice may include a plurality of stacked groups of layers, with each group of layers including stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The non-semiconductor monolayers of the first superlattice may be arranged along growth rings extending outwardly from respective adjacent nanostructure layer portions.

A method for forming an oxide layer in a vertical channel structure includes performing a pre-clean process to remove contaminants on exposed surfaces of channel pillars extending in a first direction, performing a silicon layer formation process to form a silicon layer on the exposed surfaces of the channel pillars, and performing a thermal oxidation process to convert the silicon layer to an oxide layer.

A device includes a stack of first nanostructures; a first insulating layer adjacent to the stack of first nanostructures; and a first source/drain region over the first insulating layer, wherein the first source/drain region includes: first semiconductor layers, wherein each first semiconductor layer covers a sidewall of a respective first nanostructure, wherein the first semiconductor layers includes a first semiconductor material; second semiconductor layers, wherein each second semiconductor layer covers a sidewall of a respective first semiconductor layer, wherein the second semiconductor layers includes a second semiconductor material different from the first semiconductor material; and a third semiconductor layer on the second semiconductor layer, wherein the third semiconductor layer is a third semiconductor material different from the first semiconductor material and different from the second semiconductor material.

A method includes forming a gate structure over fins protruding from a semiconductor substrate; forming an isolation region surrounding the fins; depositing a spacer layer over the gate structure and over the fins, wherein the spacer layer fills the regions extending between pairs of adjacent fins; performing a first etch on the spacer layer, wherein after performing the first etch, first remaining portions of the spacer layer that are within inner regions extending between pairs of adjacent fins have a first thickness and second remaining portions of the spacer layer that are not within the inner regions have a second thickness less than the first thickness; and forming an epitaxial source/drain region adjacent the gate structure and extending over the fins, wherein portions of the epitaxial source/drain region within the inner regions are separated from the first remaining portions of the spacer layer.