Abstract: Provided are multi-gate devices and methods for fabricating such devices. An exemplary method includes forming gate structures over a semiconductor material, wherein the gate structures include a long channel (LC) gate structure and a short channel (SC) gate structure; forming a patterned mask over the semiconductor material, wherein the LC gate structure and the SC gate structure are not covered by the patterned mask; and performing an etch process on the LC gate structure and on the SC gate structure through the patterned mask to remove the LC gate structure and the SC gate structure, wherein removal of the LC gate structure forms a deep trench in the semiconductor substrate having a first depth, and wherein removal of the SC gate structure forms a shallow trench in the semiconductor substrate having a second depth less than the first depth.

Abstract: A method for fabricating semiconductor devices includes forming channel regions over a substrate. The channel regions, in parallel with one another, extend along a first lateral direction. Each channel region includes at least a respective pair of epitaxial structures. The method includes forming a gate structure over the channel regions, wherein the gate structure extends along a second lateral direction. The method includes removing, through a first etching process, a portion of the gate structure that was disposed over a first one of the channel regions. The method includes removing, through a second etching process, a portion of the first channel region. The second etching process includes one silicon etching process and one silicon oxide deposition process. The method includes removing, through a third etching process controlled based on a pulse signal, a portion of the substrate that was disposed below the removed portion of the first channel region.

Abstract: A semiconductor device includes a first channel region extending in a first lateral direction, and comprising a first epitaxial structure; a second channel region extends in the first lateral direction, next to the first channel region along a second lateral direction, and comprising a pair of second epitaxial structures; a third channel region formed over the substrate, extending in the first lateral direction, disposed next to the first channel region along the second lateral direction, and comprising a pair of third epitaxial structures; first and second metal gate structures extend in the second lateral direction and traverse the second and third channel regions, respectively. A first upper portion of the dielectric structure has its opposite sidewalls tilted away from each other along a vertical direction extending from a top surface of the dielectric structure toward the substrate.

Abstract: A semiconductor structure includes a substrate, a multi-gate FET device disposed over the substrate, a first isolation disposed in the substrate, and a second isolation disposed in the substrate. The multi-gate FET device includes a gate structure and epitaxial source/drain structures disposed at two sides of the gate structure. The first isolation includes a first portion and a second portion over the first portion. A top surface of the second portion is aligned with a top surface of the epitaxial source/drain structures. A width of the second portion is different from a width of the first portion.

Abstract: A semiconductor device includes a first channel region extending in a first lateral direction, and comprising a first epitaxial structure; a dielectric structure extending in a second lateral direction and disposed next to the first epitaxial structure; a plurality of first semiconductor sections interposed between a first sidewall of the dielectric structure and the first epitaxial structure; and a plurality of first dielectric sections interposed between the first sidewall of the dielectric structure and the first epitaxial structure. The first dielectric sections are alternately arranged with the first semiconductor sections. The dielectric structure has a second sidewall opposite to the first sidewall in the first lateral direction. A maximum variance percentage of a distance between the first sidewall and second sidewall is less than about 50%.

Abstract: A method includes forming a plurality of semiconductor structures over a semiconductor substrate, forming a dummy gate stack on top surfaces and sidewalls of the plurality of semiconductor structures, forming gate spacers on sidewalls of the dummy gate stack, and etching a first portion of the dummy gate stack to form a through-gate trench in the dummy gate stack. The dummy gate stack includes a second portion and a third portion on opposing sides of the first portion. Through the through-gate trench, the plurality of semiconductor structures are etched to form a trench group underlying and connected to the through-gate trench. The trench group includes two outmost trenches, and at least one inner trench between the two outmost trenches. The two outmost trenches are deeper than the at least one inner trench.

Abstract: A semiconductor device structure, along with methods of forming such, are described. The semiconductor device structure includes a substrate and an isolation structure disposed on the substrate and between two neighboring transistors. The isolation structure includes a dielectric feature, an insulating material disposed below the dielectric feature. The insulating material includes an upper portion comprising a first sidewall and a top surface in contact with the dielectric feature, and a bottom portion having a second sidewall, wherein the second sidewall is surrounded by and in contact with the substrate. The insulating material further includes a middle portion having a third sidewall disposed between the first sidewall and the second sidewall. The semiconductor device structure also includes a dielectric material in contact with the dielectric feature, the first sidewall, the third sidewall, and the substrate.

Abstract: A semiconductor device structure, along with methods of forming such, are described. The structure includes a fin disposed over a semiconductor substrate, and the fin has a first width. The structure further includes an isolation region disposed around the fin, a gate electrode disposed over the fin and the isolation region, and a fill material disposed in the gate electrode. The fill material is in contact with a top surface of a portion of the semiconductor substrate, the top surface has at least a portion having a substantially flat cross-section, and the portion of the top surface has a second width substantially greater than the first width.

Abstract: The present disclosure describes a structure that provides insulation in a semiconductor device and a method for forming the structure. The structure includes a first isolation structure including a first isolation layer disposed on a substrate, a second isolation layer disposed on the first isolation layer, and a first high-k dielectric layer having a first height and disposed on the second isolation layer. The structure further includes a second isolation structure including a third isolation layer disposed on the substrate, a fourth isolation layer disposed on the third isolation layer, and a second high-k dielectric layer having a second height and disposed on the fourth isolation layer, where the second height is less than the first height. The structure further includes a gate structure disposed on the first isolation structure, and an insulating structure disposed adjacent to the gate structure and on the second isolation structure.