Semiconductor device structures having gate structures with tunable threshold voltages are provided. Various geometries of device structure can be varied to tune the threshold voltages. In some examples, distances from tops of fins to tops of gate structures can be varied to tune threshold voltages. In some examples, distances from outermost sidewalls of gate structures to respective nearest sidewalls of nearest fins to the respective outermost sidewalls (which respective gate structure overlies the nearest fin) can be varied to tune threshold voltages.

A method of forming a semiconductor device includes forming a fin protruding above a substrate; forming a liner over the fin; performing a surface treatment process to convert an upper layer of the liner distal to the fin into a conversion layer, the conversion layer comprising an oxide or a nitride of the liner; forming isolation regions on opposing sides of the fin after the surface treatment process; forming a gate dielectric over the conversion layer after forming the isolation regions; and forming a gate electrode over the fin and over the gate dielectric.

The present disclosure generally relates to semiconductor device fabrication and integrated circuits. More particularly, the present disclosure relates to replacement metal gate processes and structures for multi-gate transistor devices having a short channel and a long channel component.

Semiconductor devices and methods of fabricating semiconductor devices are provided. The present disclosure provides a semiconductor device that includes a first fin structure and a second fin structure each extending from a substrate; a first gate segment over the first fin structure and a second gate segment over the second fin structure; a first isolation feature separating the first and second gate segments; a first source/drain (S/D) feature over the first fin structure and adjacent to the first gate segment; a second S/D feature over the second fin structure and adjacent to the second gate segment; and a second isolation feature also disposed in the trench. The first and second S/D features are separated by the second isolation feature, and a composition of the second isolation feature is different from a composition of the first isolation feature.

Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a gate dielectric layer around first channel layers in a p-type gate region and around second channel layers in an n-type gate region. Sacrificial features are formed between the second channel layers in the n-type gate region. A p-type work function layer is formed over the gate dielectric layer in the p-type gate region and the n-type gate region. After removing the p-type work function layer from the n-type gate region, the sacrificial features are removed from between the second channel layers in the n-type gate region. An n-type work function layer is formed over the gate dielectric layer in the n-type gate region. A metal fill layer is formed over the p-type work function layer in the p-type gate region and the n-type work function layer in the n-type gate region.

A 3D semiconductor device, the device comprising: a first level comprising a single crystal layer, first transistors and a first metal layer; memory control circuits comprising said first transistors; a second level disposed above said first level, said second level comprising second transistors; a third level disposed above said second level, said third level comprising a plurality of third transistors; wherein said third transistors are aligned to said first transistors with a less than 40 nm alignment error, wherein said second level comprises a plurality of first memory cells, wherein said third level comprises a plurality of second memory cells, wherein one of said second transistors is at least partially self-aligned to at least one of said third transistors, being processed following a same lithography step, wherein at least one of said second memory cells comprises at least one of said third transistors, wherein said memory cells comprise a NAND non-volatile memory type.

Certain aspects of the present disclosure generally relate to techniques for reducing leakage current in polysilicon-on-active-edge structures. An example transistor structure includes one or more active devices and at least one dummy device disposed at an edge of the transistor structure, wherein the at least one dummy device has a different gate structure than the one or more active devices.

The present invention relates generally to semiconductors, and more particularly, to a structure and method of minimizing shorting between epitaxial regions in small pitch fin field effect transistors (FinFETs). In an embodiment, a dielectric region may be formed in a middle portion of a gate structure. The gate structure be formed using a gate replacement process, and may cover a middle portion of a first fin group, a middle portion of a second fin group and an intermediate region of the substrate between the first fin group and the second fin group. The dielectric region may be surrounded by the gate structure in the intermediate region. The gate structure and the dielectric region may physically separate epitaxial regions formed on the first fin group and the second fin group from one another.

A method for manufacturing a semiconductor device includes forming a semiconductor fin on a substrate. A dummy gate structure is formed crossing the semiconductor fin. The dummy gate structure is replaced with a metal gate structure. An epitaxial structure is formed in the semiconductor fin after replacing the dummy gate structure with the metal gate structure.

A semiconductor device includes a dielectric dummy gate, a plurality of first semiconductor fins, and a plurality of second semiconductor fins. The dielectric dummy gate extends along a first direction. The first semiconductor fins extend along a second direction within a first core circuit region on a first side of the dielectric dummy gate, and the second direction is substantially perpendicular to the first direction. The second semiconductor fins extend along the second direction within a second core circuit region on a second side of the dielectric dummy gate opposite the first side of the dielectric dummy gate. A number of the second semiconductor fins within the second core circuit region is less than a number of the first semiconductor fins within the first core circuit region, and each of the second semiconductor fins has a width less than a width of each of the first semiconductor fins.