A semiconductor device includes; an active region extending in a first horizontal direction on a substrate, source/drain regions disposed on the active region, a buried trench formed between the source/drain regions, a buried insulating layer surrounding both side walls of the buried trench in the first horizontal direction between the source/drain regions, a wing trench formed in a lower part of the buried trench and having a width greater than a width of the buried trench, and a gate electrode extending in a second horizontal direction on the active region, and disposed within each of the buried trench and the wing trench.

A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; a second metal layer overlaying the first metal layers; and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where the second transistors each include at least two side-gates, where the second level is bonded to the first level, and where the bonded includes oxide to oxide bonds.

A method for producing a 3D semiconductor device including: providing a first level including a first single crystal layer; forming peripheral circuitry in and/or on the first level, and includes first single crystal transistors; forming a first metal layer on top of the first level; forming a second metal layer on top of the first metal layer; forming second level disposed on top of the second metal layer; performing a first lithography step; forming a third level on top of the second level; performing a second lithography step; processing steps to form first memory cells within the second level and second memory cells within the third level, where the plurality of first memory cells include at least one second transistor, and the plurality of second memory cells include at least one third transistor; and deposit a gate electrode for second and third transistors simultaneously.

A semiconductor device structure includes a source/drain feature comprising a first surface, a second surface opposing the first surface, and a sidewall connecting the first surface to the second surface. The structure also includes a dielectric layer having a continuous surface in contact with the entire second surface of the source/drain feature, a semiconductor layer having a first surface, a second surface opposing the first surface, and a sidewall connecting the first surface to the second surface, wherein the sidewall of the semiconductor layer is in contact with the sidewall of the source/drain feature. The structure also includes a gate dielectric layer in contact with the continuous surface of the dielectric layer and the second surface of the semiconductor layer, and a gate electrode layer surrounding a portion of the semiconductor layer.

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.

In a method of manufacturing a semiconductor device, a fin structure protruding from a first isolation insulating layer is formed. A second isolation insulating layer made of different material than the first isolation insulating layer is formed so that a first upper portion of the fin structure is exposed. A dummy gate structure is formed over the exposed first upper portion of the first fin structure. The second isolation insulating layer is etched by using the dummy gate structure as an etching mask. The dummy gate structure is removed so that a gate space is formed. The second isolation insulating layer is etched in the gate space so that a second upper portion of the fin structure is exposed from the first isolation insulating layer. A gate dielectric layer and a gate electrode layer are formed over the exposed second portion of the fin structure.

Gate cutting techniques disclosed herein form gate isolation fins to isolate metal gates of multigate devices from one another before forming the multigate devices, and in particular, before forming the metal gates of the multigate devices. An exemplary device includes a first multigate device having first source/drain features and a first metal gate that surrounds a first channel layer and a second multigate device having second source/drain features and a second metal gate that surrounds a second channel layer. A gate isolation fin, which separates the first metal gate and the second metal gate, includes a first dielectric layer having a first dielectric constant and a second dielectric layer having a second dielectric constant disposed over the first dielectric layer. The second dielectric constant is less than the first dielectric constant. A gate isolation end cap may be disposed on the gate isolation fin to provide additional isolation.

A method for forming a semiconductor structure is provided. The method includes forming a stack over a substrate. The stack includes alternating first semiconductor layers and second semiconductor layers. The method also includes forming a polishing stop layer over the stack and a dummy layer over the polishing stop layer, recessing the dummy layer, the polishing stop layer and the stack to form a recess, forming a third semiconductor layer to fill the recess, and planarizing the dummy layer and the third semiconductor layer until the polishing stop layer is exposed. The method also includes patterning the polishing stop layer and the stack into a first fin structure and the third semiconductor layer into a second fin structure, removing the second semiconductor layers of the first fin structure to form nanostructures, and forming a gate stack across the first fin structure and the second fin structure.

A includes depositing a gate electrode layer over a semiconductor substrate; patterning the gate electrode layer into a first gate electrode and a gate electrode extending portion; forming a first gate spacer alongside the first gate electrode; patterning the gate electrode extending portion into a second gate electrode after forming the first gate spacer; and forming a second gate spacer alongside the second gate electrode and a third gate spacer around the first spacer.

Various implementations described herein relate to a method for manufacturing, or causing to be manufactured, multiple devices packaged within a single semiconductor die. The multiple devices may have first devices that are arranged in a first multi-transistor stack with a first P-N configuration. The multiple devices may have second devices that are arranged in a second multi-transistor stack with a second P-N configuration that is different than the first P-N configuration.