Integrated circuit structures having backside source or drain contact differentiated access are described. In an example, an integrated circuit structure includes first, second and third pluralities of horizontally stacked nanowires or fins, and first, second and third gate stacks. A first epitaxial source or drain structure is between the first plurality of horizontally stacked nanowires or fin and the second plurality of horizontally stacked nanowires or fin, the first epitaxial source or drain structure over a first conductive material having a first depth below the first epitaxial source or drain structure. A second epitaxial source or drain structure is between the second plurality of horizontally stacked nanowires or fin and the third plurality of horizontally stacked nanowires or fin, the second epitaxial source or drain structure over a second conductive material having a second depth below the second epitaxial source or drain structure, the second depth greater than the first depth.

A method includes forming a first transistor over a substrate, in which the first transistor includes first source/drain epitaxy structures; forming a second transistor over the first transistor, in which the second transistor includes second source/drain epitaxy structures; forming an opening extending through one of the second source/drain epitaxy structures and exposing a top surface of one of the first source/drain epitaxy structures; performing a first deposition process to form a first metal in the opening, in which a first void is formed in the first metal during the first deposition process; performing a first etching back process to the first metal until the first void is absent; and performing a second deposition process to form a second metal in the opening and over the first metal.

An exemplary structure includes a semiconductor substrate; a plurality of first dielectric layers at a top side of the substrate; an active device layer at a top side of the first dielectric layers; a plurality of second dielectric layers at a top side of the active device layer; and a metal body. The body includes a first portion that is embedded in the plurality of first dielectric layers. The first portion comprises a first layer of first metal. The body further includes a second portion that is embedded in the plurality of second dielectric layers. The second portion comprises a first layer of second metal. A plurality of vias interconnect the first portion to the second portion through the active device layer. The first layer of the first portion mechanically connects the plurality of vias and the first layer of the second portion mechanically connects the plurality of vias.

Devices, transistor structures, systems, and techniques are described herein related to providing a backside passivation layer on a transistor semiconductor material. The semiconductor material is between source and drain structures, and a gate structure is adjacent a channel region of the semiconductor material. The passivation layer is formed as a conformal insulative layer on a backside of the semiconductor material and is then treated using an ozone/UV cure to remove trap charges from the semiconductor material.

Semiconductor circuit structures with direct die heat removal structure are provided. The semiconductor circuit structure comprises a semiconductor substrate with an original semiconductor surface; a set of active regions within the semiconductor substrate; and a first shallow trench isolation (STI) region neighboring to the set of active regions and extending along a first direction. Wherein the first STI region includes a heat removing layer, and the material of the heat removing layer is different from SiO.sub.2.

An exemplary device includes a frontside power rail disposed over a frontside of a substrate, a backside power rail disposed over a backside of the substrate, an epitaxial source/drain structure disposed between the frontside power rail and the backside power rail. The epitaxial source/drain structure is connected to the frontside power rail by a frontside source/drain contact. The epitaxial source/drain structure is connected to the backside power rail by a backside source/drain via. The backside source/drain via is disposed in a substrate, and a dielectric layer is disposed between the substrate and the backside power rail. The backside source/drain via extends through the dielectric layer and the substrate. A frontside silicide layer may be between the frontside source/drain contact and the epitaxial source/drain structure, and a backside silicide layer may be between the backside source/drain contact and the epitaxial source/drain structure, such that the epitaxial source/drain structure between silicide layers.

Techniques are disclosed herein for creating metal bitlines (BLs) in stacked wafer memory. Using techniques described herein, metal BLs are created on a bottom surface of a wafer. The metal BLs can be created using different processes. In some configurations, a salicide process is utilized. In other configurations, a damascene process is utilized. Using metal reduces the resistance of the BLs as compared to using non-metal diffused BLs. In some configurations, wafers are stacked and bonded together to form three-dimensional memory structures.

A method includes providing a semiconductor structure having a metal gate structure (MG), gate spacers disposed on sidewalls of the MG, and a source/drain (S/D) feature disposed adjacent to the gate spacers; forming a first metal layer over the S/D feature and between the gate spacers; recessing the first metal layer to form a trench; forming a dielectric layer on sidewalls of the trench; forming a second metal layer over the first metal layer in the trench, wherein sidewalls of the second metal layer are defined by the dielectric layer; and forming a contact feature over the MG to contact the MG.

An integrated circuit includes a first nanostructure transistor having a first gate electrode and a second nanostructure transistor having a second gate electrode. A dielectric isolation structure is between the first and second gate electrodes. A gate connection metal is on a portion of the top surface of the first gate electrode and on a portion of a top surface of the second gate electrode. The gate connection metal is patterned to expose other portions of the top surfaces of the first and second gate electrodes adjacent to the dielectric isolation structure. A conductive via contacts the exposed portion of the top surface of the second gate electrode.

Embodiments of the present disclosure describe techniques and configurations to reduce transistor gate short defects. In one embodiment, a method includes forming a plurality of lines, wherein individual lines of the plurality of lines comprise a gate electrode material, depositing an electrically insulative material to fill regions between the individual lines and subsequent to depositing the electrically insulative material, removing a portion of at least one of the individual lines to isolate gate electrode material of a first transistor device from gate electrode material of a second transistor device. Other embodiments may be described and/or claimed.