Method for forming recess-free interconnect structure

A method for forming an interconnect structure includes forming a dielectric material layer on a semiconductor substrate. An oxygen-rich layer is formed over the dielectric material layer. The dielectric material layer and the oxygen-rich layer are patterned to form a plurality of vias in the semiconductor substrate. A barrier layer is formed in the plurality of vias and on the dielectric material layer leaving a portion of the oxygen-rich layer exposed. A metal layer is formed on the bather layer and on the exposed portion of the oxygen-rich layer, wherein the metal layer fills the plurality of vias. The semiconductor substrate is annealed at a predetermined temperature range and at a predetermined pressure to transform the exposed portion of the oxygen-rich layer into a metal-oxide stop layer.