Abstract: Semiconductor structures and fabrication methods thereof are provided. The method may include providing a to-be-etched layer; forming a plurality of core layers on the to-be-etched layer, wherein a first opening and a second opening are formed between different adjacent core layers and a width of the first opening is smaller than a width of the second opening; forming a first sacrificial material layer on the to-be-etched layer and the plurality of core layers; forming a second sacrificial layer on a portion of the first sacrificial material layer in the first opening to form a sacrificial structure in the first opening; removing the plurality of core layers after forming the sacrificial structure; forming sidewall spacers on sidewall surfaces of the sacrificial structure after removing the plurality of core layers; and removing the sacrificial structure after forming the sidewall spacers.

Abstract: A method of manufacturing a semiconductor device includes providing a substrate structure, which includes a substrate, one or more semiconductor fins on the substrate, a gate structure on each fin, an active region located in said fins, and an interlayer dielectric layer covering at the active region. The method includes forming a hard mask layer over the interlayer dielectric layer and the gate structure, and using an etch process with a patterned etch mask, forming a first contact hole extending through the hard mask layer and extending into a portion of the interlayer dielectric layer, using patterned a mask. The method further includes forming a sidewall dielectric layer on sidewalls of the first contact hole, and using an etch process with the sidewall dielectric layer as an etch mask, etching the interlayer dielectric layer at bottom of the first contact hole to form a second contact hole extending to the active region.

Abstract: Semiconductor structures and fabrication methods thereof are provided. The method may include providing a to-be-etched layer; forming a plurality of core layers on the to-be-etched layer, wherein a first opening and a second opening are formed between different adjacent core layers and a width of the first opening is smaller than a width of the second opening; forming a first sacrificial material layer on the to-be-etched layer and the plurality of core layers; forming a second sacrificial layer on a portion of the first sacrificial material layer in the first opening to form a sacrificial structure in the first opening; removing the plurality of core layers after forming the sacrificial structure; forming sidewall spacers on sidewall surfaces of the sacrificial structure after removing the plurality of core layers; and removing the sacrificial structure after forming the sidewall spacers.

Abstract: A method of manufacturing a semiconductor device includes providing a substrate structure, which includes a substrate, one or more semiconductor fins on the substrate, a gate structure on each fin, an active region located in said fins, and an interlayer dielectric layer covering at the active region. The method includes forming a hard mask layer over the interlayer dielectric layer and the gate structure, and using an etch process with a patterned etch mask, forming a first contact hole extending through the hard mask layer and extending into a portion of the interlayer dielectric layer, using patterned a mask. The method further includes forming a sidewall dielectric layer on sidewalls of the first contact hole, and using an etch process with the sidewall dielectric layer as an etch mask, etching the interlayer dielectric layer at bottom of the first contact hole to form a second contact hole extending to the active region.