A method comprises forming a first fin including alternating first channel layers and first sacrificial layers and a second fin including alternating second channel layers and second sacrificial layers, forming a capping layer over the first and the second fin, forming a dummy gate stack over the capping layer, forming source/drain (S/D) features in the first and the second fin, removing the dummy gate stack to form a gate trench, removing the first sacrificial layers and the capping layer over the first fin to form first gaps, removing the capping layer over the second fin and portions of the second sacrificial layers to from second gaps, where remaining portions of the second sacrificial layers and the capping layers form a threshold voltage (V.sub.t) modulation layer, and forming a metal gate stack in the gate trench, the first gaps, and the second gaps.

Embodiments disclosed herein include semiconductor devices and methods of forming such devices. In an embodiment, a semiconductor device comprises a first transistor on a first level, and a second transistor on a second level above the first level. In an embodiment, an insulating layer is between the first level and the second level, and a via passes through the insulating layer, and electrically couples the first transistor to the second transistor. In an embodiment, the first transistor and the second transistor comprise a first channel, and a second channel over the first channel. In an embodiment, the first second transistor further comprise a gate structure between the first channel and the second channel, a source contact on a first end of the first channel and the second channel, and a drain contact on a second end of the first channel and the second channel.

A semiconductor structure includes a substrate and first and second SRAM cells. The first SRAM cell includes first and second pull-up transistors, first and second pull-down transistors, and first and second pass-gate transistors. The first and the second pass-gate transistors have a first channel width. The first and the second pull-down transistors have a second channel width. A ratio of the second channel width to the first channel width is in a range of 1.05 to 1.5. The second SRAM cell includes third and fourth pull-up transistors, third and fourth pull-down transistors, and third and fourth pass-gate transistors. The third and the fourth pass-gate transistors have a third channel width. The third and the fourth pull-down transistors have a fourth channel width. The third and the fourth channel widths are substantially same. The fourth channel width is larger than the second channel width. The transistors are GAA transistors.

A semiconductor device includes an active region that extends in a first horizontal direction. A source/drain component is disposed over the active region. A source/drain contact is disposed over the source/drain component. A gate structure is disposed over the active region. The gate structure extends in a second horizontal direction different from the first horizontal direction. Side surfaces of the source/drain contact are substantially more tapered in the second horizontal direction than in the first horizontal direction.

A 3D semiconductor device including: a first single crystal layer with first transistors; overlaid by a first metal layer; a second metal layer overlaying the first metal layer and being overlaid by a third metal layer; a logic gates including at least the first metal layer interconnecting the first transistors; second transistors disposed atop the third metal layer; third transistors disposed atop the second transistors; a top metal layer disposed atop the third transistors; and a memory array including word-lines, and at least four memory mini arrays, where each of the memory mini arrays includes at least four rows by four columns of memory cells, where each of the memory cells includes at least one of the second transistors or third transistors, sense amplifier circuit(s) for each of the memory mini arrays, the second metal layer provides a greater current carrying capacity than the third metal layer.

An SRAM memory device includes a substrate, a first transistor, a second transistor, a metal interconnect structure, and a capacitor. The metal interconnect structure is formed on the first and second transistors. The capacitor is disposed in the metal interconnect structure and coupled between the first transistor and the second transistor. The capacitor includes a lower metal layer, a first electrode layer, a dielectric layer, a second electrode layer, and an upper metal layer from bottom to top. The lower metal layer is coupled to a source node of the first transistor and a source node of the second transistor. The lower metal layer and an n-th metal layer in the metal interconnect structure are formed of a same material, wherein n≥1; the upper metal layer and an m-th metal layer in the metal interconnect structure are formed of a same material, wherein m≥n+1.

Semiconductor structures and methods are provided. A method according to the present disclosure includes forming a first channel member, a second channel member directly over the first channel member, and a third channel member directly over the second channel member, depositing a first metal layer around each of the first channel member, the second channel member, and the third channel member, removing the first metal layer from around the second channel member and the third channel member while the first channel member remains wrapped around by the first metal layer, after the removing of the first metal layer, depositing a second metal layer around the second channel member and the third channel member, removing the second metal layer from around the third channel member, and after the removing of the second metal layer, depositing a third metal layer around the third channel member.

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 method and structure for modulating a threshold voltage of a device. In various embodiments, a fin extending from a substrate is provided. In some embodiments, the fin includes a plurality of semiconductor channel layers defining a channel region for a P-type transistor. In some examples, a gate dielectric is formed wrapping around each of the plurality of semiconductor channel layers of the P-type transistor. In some cases, a P-type work function (PWF) metal gate cap is formed wrapping around the gate dielectric. In various embodiments, the PWF metal gate cap merges between adjacent semiconductor channel layers of the plurality of channel layers. Additionally, in some examples, the PWF metal gate cap includes a plurality of nitrogen-containing layers.

A method for producing a 3D memory device, the method including: providing a first level including a first single crystal layer and control circuits; forming at least one second level above the first level; performing a first etch step including etching holes within the second level; forming at least one third level above the at least one second level; performing a second etch step including etching holes within the third level; and performing additional processing steps to form a plurality of first memory cells within the second level and a plurality of second memory cells within the third level, where each of the first memory cells include one first transistor, where each of the second memory cells include one second transistor, where at least one of the first or second transistors has a channel, a source, and a drain having a same doping type.