A semiconductor interconnect structure is formed as a via with an inverted-T shape to increase the reliability of the interface between the interconnect structure and an underlying electrically conductive, e.g., copper (Cu), layer of material. The inverted-T shape effectively increases a bottom critical dimension of the via, thereby reducing and/or eliminating via degradation of the interconnect structure caused by voids in the electrically conductive layer introduced during high-temperature or stress-migration baking.