A semiconductor device, the device including: a first silicon layer including a first single crystal silicon; a first metal layer disposed over the first silicon layer; a second metal layer disposed over the first metal layer; a first level including a plurality of transistors, the first level disposed over the second metal layer, where the plurality of transistors include a second single crystal silicon; a third metal layer disposed over the first level; a fourth metal layer disposed over the third metal layer, where the fourth metal layer is aligned to the first metal layer with a less than 40 nm alignment error; and a via disposed through the first level, where the first level thickness is less than two microns.

A buried power rail is provided in a non-active device region. The buried power rail includes a dielectric liner located on a lower portion of a sidewall and a bottommost surface of the buried power rail. A dielectric cap is located on an upper portion of the sidewall of the buried power rail as well as on a topmost surface of the buried power rail. The dielectric cap is present during the fabrication of a functional gate structure and thus the problems associated with prior art buried power rails are circumvented. The dielectric cap can be removed after the functional gate structure has been formed and a via to buried power rail (VBPR) contact structure can be formed in contact with the buried power rail. In some applications, and after a gate cut process, a gate cut dielectric structure can be formed in contact with the dielectric cap.

A 3D semiconductor device, the device comprising: a first level comprising a first single crystal layer, said first level comprising first transistors, wherein each of said first transistors comprises a single crystal channel; first metal layers interconnecting at least said first transistors; a second metal layer overlaying said first metal layers; and a second level comprising a second single crystal layer, said second level comprising second transistors, wherein said second level overlays said first level, wherein at least one of said second transistors comprises a gate all around structure, wherein said second level is directly bonded to said first level, and wherein said bonded comprises direct oxide to oxide bonds.

A semiconductor device includes a substrate, a front side circuit disposed over a front surface of the substrate, and a backside power delivery circuit disposed over a back surface and including a back side power supply wiring coupled to a first potential. The front side circuit includes semiconductor fins and a first front side insulating layer covering bottom portions of the semiconductor fins, a plurality of buried power supply wirings embedded in the first front side insulating layer, the plurality of buried power supply wirings including a first buried power supply wiring and a second buried power supply wiring, and a power switch configured to electrically connect and disconnect the first buried power supply wiring and the second buried power supply wiring. The second buried power supply wiring is connected to the back side power supply wiring by a first through-silicon via passing through the substrate.

Some embodiments include an integrated assembly having a pair of substantially parallel features spaced from one another by an intervening space. A conductive pipe is between the features and substantially parallel to the features. The conductive pipe may be formed within a tube. The tube may be generated by depositing insulative material between the features in a manner which pinches off a top region of the insulative material to leave the tube as a void region under the pinched-off top region.

A 3D semiconductor device including: a first level including a single crystal silicon layer and a plurality of first transistors each including a single crystal channel; a first metal layer overlaying the plurality of first transistors; a second metal layer overlaying the first metal layer; a third metal layer overlaying the second metal layer; a second level, where the second level overlays the first level and includes a plurality of second transistors; a fourth metal layer overlaying the second level; and a connective path between the fourth metal layer and either the third metal layer or the second metal layer, where the connective path includes a via disposed through the second level and has a diameter of less than 500 nm and greater than 5 nm, where the third metal layer is connected to provide a power or ground signal to at least one of the second transistors.

Structures with altered crystallinity beneath semiconductor devices and methods associated with forming such structures. Trench isolation regions surround an active device region composed of a single-crystal semiconductor material. A first non-single-crystal layer is arranged beneath the trench isolation regions and the active device region. A second non-single-crystal layer is arranged beneath the trench isolation regions and the active device region. The first non-single-crystal layer is arranged between the second non-single-crystal layer and the active device region.

A method for forming a FinFET device structure and method for forming the same is provided. The method includes forming an isolation structure over a substrate and forming a first dielectric layer over the isolation structure. The method includes forming a gate structure in the first dielectric layer and forming a deep trench through the first dielectric layer and the isolation structure. The method also includes forming an S/D trench in the first dielectric layer and filling a metal material in the deep trench and the S/D trench to form a deep contact structure and the S/D contact structure. A bottom surface of the S/D contact structure is higher than a bottom surface of the deep contact structure.

A self-aligned buried power rail having an adjustable height is formed between a first semiconductor device region and a second semiconductor device region. The self-aligned buried power rail having the adjustable height has improved conductivity. Notably, the self-aligned buried power rail has a first portion having a first height that is present in a gate cut trench and a second portion having a second height, which is greater than the first height, that is present in a source/drain cut trench.

A method of fabricating a metal mask includes receiving a conductive substrate with a first surface, a second surface opposite to the first surface, a third surface connecting the first and second surfaces, and a fourth surface opposite to the third surface and connecting the first and second surfaces. The method further includes forming trenches in a direction from the first surface to the second surface and protrusions in the conductive substrate. The trenches and the protrusions are alternately arranged. The method further includes filling the trenches with an insulation material covering a first area of the protrusions, forming a metal layer on the conductive substrate overlying a second area different from the first area of the protrusions, removing the insulation material, and removing the conductive substrate. The metal layer becomes a metal mask with a three-dimensional structure including strip-shaped structures.