1.1 This guide covers recommended design features for test structures used in accelerated stress tests, as described in Test Method F 1260M, to characterize the failure distribution of interconnect metallizations that fail due to electromigration. 1.2 This guide is restricted to structures with a straight test line on a flat surface that are used to detect failures due to an open-circuit or a percent-increase in resistance of the test line. 1.3 This guide is not intended for testing metal lines whose widths are approximately equal to or less than the estimated mean size of the metal grains in the metallization line. 1.4 This guide is not intended for test structures used to detect random defects in a metallization line. 1.5 Metallizations tested and characterized are those that are used in microelectronic circuits and devices.