Self-aligned interconnect structure

Abstract

The present disclosure relates to a semiconductor structure including an interconnect structure disposed over a semiconductor substrate. A lower metal line is disposed at a first height over the semiconductor substrate and extends through a first interlayer dielectric layer. A second interlayer dielectric layer is disposed at a second height over the semiconductor substrate and comprises a first dielectric material. An upper metal line is disposed at a third height over the semiconductor substrate. A via is disposed at the second height. The via extends between the lower metal line and the upper metal line. A protective dielectric structure is disposed at the second height. The protective dielectric structure comprises a protective dielectric material and is disposed along a first set of opposing sidewalls of the via, the protective dielectric material differing from the first dielectric material.