主权项 |
1. A structure for testing an integrated circuit comprising:
a semiconductor substrate; a first via chain disposed over the semiconductor substrate, wherein the first via chain includes a first sequence of segments interconnected at N via regions by a first via arrangement, wherein the first via arrangement includes MN first vias at each respective via region in the first via chain; a second via chain disposed over the semiconductor substrate, wherein the second via chain includes a second sequence of segments interconnected at N via regions by a second via arrangement different from the first via arrangement, wherein the second via arrangement includes MN+KN second vias at each via region in the second via chain, wherein KN≧1 for at least one via region, and wherein the second sequence of segments is substantially the same as the first sequence of segments; and a voltage sensing apparatus in electrical connection with each via chain and configured to drive a first constant current through the first via chain and to drive a second constant current through the second via chain to measure a differential voltage between the via chains. |