A semiconductor device includes an active pattern including a channel region. The channel region is disposed between first and second source/drain patterns that are spaced apart from each other in a first direction. The channel region is configured to connect the first and second source/drain patterns to each other. A gate electrode is disposed on a bottom surface of the active pattern and is disposed between the first and second source/drain patterns. An upper interconnection line is disposed on a top surface of the active pattern opposite to the bottom surface of the active pattern and is connected to the first source/drain pattern.

A semiconductor structure includes a stacked device structure having a first field-effect transistor having a first source/drain region, and a second field-effect transistor vertically stacked above the first field-effect transistor, the second field-effect transistor having a second source/drain region and a gate region having first sidewall spacers. The stacked device structure further includes a frontside source/drain contact disposed on a first portion of a sidewall and a top surface of the second source/drain region, a first metal via connected to the frontside source/drain contact and to a first backside power line, and second sidewall spacers disposed on a first portion of the first metal via. The first sidewall spacers comprise a first dielectric material and the second sidewall spacers comprise a second dielectric material different than the first dielectric material.

A method includes forming a lower transistor in a lower wafer, wherein the lower transistor includes a lower source/drain region, forming a contact plug electrically connecting to the lower source/drain region, and forming a metal line over the lower transistor. A first portion of the metal line is vertically aligned to the lower source/drain region. The method further includes bonding an upper wafer to the lower wafer, and forming an upper transistor in the upper wafer. The upper transistor includes an upper source/drain region, and is vertically aligned to a second portion of the metal line. A first interconnect structure is formed on the lower wafer and electrically connecting to the lower transistor. A second interconnect structure is formed on the upper wafer and electrically connecting to the upper transistor.

A method includes forming a first transistor in a first wafer, wherein the first transistor includes a first source/drain region, forming a first bond pad electrically coupling to the first source/drain region, forming an second transistor in a second wafer, wherein the second transistor includes a second source/drain region, forming a second bond pad electrically coupling to the second source/drain region, and bonding the second wafer to the first wafer, with the second bond pad being bonded to the first bond pad.

Embodiments of the present disclosure relates to a semiconductor device structure. The structure includes a first source/drain feature, a first interlayer dielectric (ILD) disposed over the first source/drain feature, a first conductive feature extending through the first ILD and in electrical contact with the first source/drain feature, and a gate electrode layer extending through the first ILD and disposed adjacent the first conductive feature, wherein a top surface of the first conductive feature and a top surface of the gate electrode layer are substantially co-planar.

Device-level interconnects having high thermal stability for stacked device structures are disclosed herein. An exemplary stacked semiconductor structure includes an upper source/drain contact disposed on an upper epitaxial source/drain, a lower source/drain contact disposed on a lower epitaxial source/drain, and a source/drain via connected to the upper source/drain contact and the lower source/drain contact. The source/drain via is disposed on the upper source/drain contact, the source/drain via extends below the upper source/drain contact, and the source/drain via includes ruthenium and aluminum. In some embodiments, the source/drain via includes a ruthenium plug wrapped by an aluminum liner. In some embodiments, the source/drain via includes a ruthenium aluminide plug. In some embodiments, the source/drain via includes a ruthenium plug wrapped by a ruthenium aluminide liner. In some embodiments, the source/drain via extends below a top of the lower epitaxial source/drain.

An IC device includes a first and second stacked transistor structures including respective first and second and third and fourth transistors in a semiconductor substrate, first and second bit lines and a word line on one of a front or back side of the semiconductor substrate, and a power supply line on the other of the front or back side. The first transistor includes a source/drain (S/D) terminal electrically connected to the first bit line, a S/D terminal electrically connected to a S/D terminal of the second transistor, and a gate electrically connected to the word line, the third transistor includes a S/D terminal electrically connected to the second bit line, a S/D terminal electrically connected to a S/D terminal of the fourth transistor, and a gate electrically connected to the word line, and the second and fourth transistors include S/D terminals electrically connected to the power supply line.

A semiconductor structure is provided that includes a first stacked FET cell including a second FET stacked over a first FET, and a second stacked FET cell located adjacent to the first stacked FET cell and including a fourth FET stacked over a third FET. The structure further includes a first backside source/drain contact structure located beneath the first stacked FET cell and contacting a source/drain region of the first FET, a second backside source/drain contact structure located beneath the second stacked FET cell and contacting a source/drain region of the third FET, and an angled cut region laterally separating the first backside source/drain contact structure from the second backside source/drain contact structure.

Methods for improving profiles of channel regions in semiconductor devices and semiconductor devices formed by the same are disclosed. In an embodiment, a method includes forming a semiconductor fin over a semiconductor substrate, the semiconductor fin including germanium, a germanium concentration of a first portion of the semiconductor fin being greater than a germanium concentration of a second portion of the semiconductor fin, a first distance between the first portion and a major surface of the semiconductor substrate being less than a second distance between the second portion and the major surface of the semiconductor substrate; and trimming the semiconductor fin, the first portion of the semiconductor fin being trimmed at a greater rate than the second portion of the semiconductor fin.

A method includes forming a mask layer above a substrate. The substrate is patterned by using the mask layer as a mask to form a trench in the substrate. An isolation structure is formed in the trench, including feeding first precursors to the substrate. A bias is applied to the substrate after feeding the first precursors. With the bias turned on, second precursors are fed to the substrate. Feeding the first precursors, applying the bias, and feeding the second precursors are repeated.