Abstract: A gate array integrated circuit wafer is formed having M−N generic metal interconnection layers and having performance and/or electrical testing circuits which are operative using only the M−N generic metal interconnection layers. Performance and/or electrical tests are performed after generic fabrication is completed, but before the final customization of the wafers. Wafers are sorted and assigned to performance and/or yield bins based upon the results of the performance and/or electrical tests. In another embodiment, all M layers are deposited prior to performance and/or electrical testing; however, the Mth layer is not etched within the active die area prior to performance and/or electrical testing. Subsequent to binning based upon the test results, the final customization is performed by etching the Mth metal layer.