Methods are provided for dimension-controlled via formation over a circuit structure, including over multiple adjacent conductive structures. The method(s) includes, for instance, providing a patterned multi-layer stack structure above the circuit structure, the stack structure including at least one layer, and a pattern transfer layer above the at least one layer, the pattern transfer layer being patterned with at least one via opening; providing a sidewall spacer layer within the at least one via opening to form at least one dimension-controlled via opening; and etching through the at least one layer of the stack structure using the at least one dimension-controlled via opening to facilitate providing the via(s) over the circuit structure. In one implementation, the stack structure includes a trench-opening within a patterned hard mask layer disposed between a dielectric layer and a planarization layer, and the via(s) is partially self-aligned to the trench.