An integrated circuit for locating failure process layers. The circuit has
a substrate with a scan chain disposed therein, having scan cells
connected to form a series chain. Each connection is formed according to
a layout constraint of a minimum dimension provided by design rules for
an assigned routing layer. Since the connection in the assigned routing
layer is constrained to a minimum, the scan chain is vulnerable to
variations in processes relevant to the assigned routing layer. The scan
chain makes it easier to locate processes causing low yield rate of the
scan chain.