Patent ID: 8754655

Claim:
A test structure, comprising: a via chain on a substrate, said via chain comprising: at least two first wire segments in a first wiring level, at least two second wire segments in a second wiring level and at least two third wire segments in a third wiring level, said second wiring level between said first wiring level and said third wiring level, said first, second and third wire segments electrically connected in series by electrically conductive first vias located only between said first wire segments and second wire segments and by electrically conductive second vias located only between said second wire segments and said third wire segments, each wire segment of said first, second and third wire segments extending the length of said via chain in a direction parallel to a top surface of said substrate; first and second pads connected to respective opposite first and second ends of said via chain; a digitated wire structure in said second wiring level, finger wires of said digitated wire structure parallel to and on opposite sides of at least a section of said via chain, said digitated wire structure electrically isolated from said first via chain; and a third pad electrically connected to said digitated wire structure.