Non-bridging contact via structures in proximity
A first photoresist layer is patterned with a first pattern that includes an opening in a region between areas of two adjacent via holes to be formed. The opening in the first photoresist is transferred into a template layer to form a line trench therein. The lateral dimension of the trench is reduced by depositing a contiguous spacer layer that does not fill the trench completely. An etch-resistant material layer is conformally deposited and fills the trench, and is subsequently recessed to form an etch-resistant material portion filling the trench. A second photoresist layer is applied and patterned with a second pattern, which includes an opening that includes areas of two via holes and an area therebetween. A composite pattern of an intersection of the second pattern and the complement of the pattern of the etch-resistant material portion is transferred through the template layer.
1. A structure comprising:
a stack of a template layer and a contiguous spacer layer, wherein said contiguous spacer layer is located on an entire topmost surface of said template layer, and wherein sidewall surfaces of said template layer are vertically aligned to sidewall surfaces of said contiguous spacer layer;
an etch-resistant material portion overlying an entirety of a recessed portion of said stack, wherein said etch resistant material portion has sidewall surfaces that are vertically aligned to sidewall surfaces of said recessed portion of said stack; and
a pair of via structures embedded within said stack and laterally spaced by said etch-resistant material portion and said recessed portion of said stack, wherein a top surface of said contiguous spacer layer, a top surface of said etch-resistant material portion, and top surfaces of said pair of via structures are coplanar among one another, and wherein said etch-resistant material portion has an H-shaped pattern, and a lateral extent of said pair of via structures is bounded by a pair of parallel line portions within said H-shaped pattern.
2. The structure of claim 1 , wherein an entirety of said contiguous spacer layer is contiguous, and said contiguous spacer layer has a same thickness in said recessed portion of said template layer as in a non-recessed portion of said template layer.
3. The structure of claim 1 , wherein said etch-resistant material portion has a rectangular portion that laterally contacts said pair of via structures.
4. The structure of claim 1 , wherein said etch-resistant material portion comprises a dielectric metal oxide.
5. The structure of claim 1 , wherein etch-resistant material portion has a sub-lithographic lateral dimension for deep ultraviolet lithography.
6. The structure of claim 1 , wherein each of said pair of via structures has three sidewalls in physical contact with sidewalls of said etch-resistant material portion and one sidewall that is not in physical contact with said etch-resistant material portion.
7. The structure of claim 6 , wherein each of said three sidewalls is in physical contact with a sidewall of said contiguous spacer layer.
8. The structure of claim 7 , wherein each of said three sidewalls is in physical contact with a sidewall of said template layer.
9. The structure of claim 1 , wherein a sidewall of one of said pair of via structures and two sidewall surfaces of said etch-resistant material portion are within a same vertical plane.
10. A structure comprising:
a stack of a template layer and a contiguous spacer layer, wherein said contiguous spacer layer is located on an entire topmost surface of said template layer, and wherein sidewall surfaces of said template layer are vertically aligned to sidewall surfaces of said contiguous spacer layer;
an etch-resistant material portion overlying an entirety of a recessed portion of said stack, wherein said etch resistant material portion has sidewall surfaces that are vertically aligned to sidewall surfaces of said recessed portion of said stack; and
a pair of via structures embedded within said stack and laterally spaced by said etch-resistant material portion and said recessed portion of said stack, wherein a top surface of said contiguous spacer layer, a top surface of said etch-resistant material portion, and top surfaces of said pair of via structures are coplanar among one another, and wherein said etch-resistant material portion has a rectangular shape, and said pair of via structures is separated along a widthwise direction of said rectangular shape.