A method of forming an interconnect structure for a standard cell semiconductor device is disclosed. In one aspect, the method includes forming metal lines along respective routing tracks, wherein forming the metal lines includes depositing, on a first dielectric layer covering the active regions of the cell, a metal layer and a capping layer on the metal layer; patterning the capping layer and the metal layer to form first and second capped off-center metal lines extending along first and second off-center tracks, respectively; forming spacer lines on sidewalls of the capped off-center metal lines; and embedding the spacer-provided capped off-center metal lines in a second dielectric layer. The method further includes patterning a set of trenches in the second dielectric layer. The set of trenches includes a center trench extending along a center track between the spacer-provided capped off-center lines, and a first and a second edge trench extending along first and second edge tracks, respectively, on mutually opposite outer sides of the spacer-provided capped off-center metal lines. The method further includes forming a center metal line in the center trench, and a first and a second edge metal line in the first and second edge trenches, respectively.