Defect isolation methods and systems

Abstract

A test system for testing devices is disclosed. The test system includes a scanning microscope module and a test module. The scanning microscope module, when testing a device under test (DUT), is configured to perturb the DUT with a laser at a test (pixel) location. The test module includes a tester unit, a reference failure log containing prior failing compare vectors of interest, and a comparator unit which includes a software comparator. The tester unit is configured to perform a test run at the test location of the DUT with a test pattern. If the test run fails testing, the tester unit is configured to compare using the comparator unit to determine if failing test vectors of the test run matches a desired failure signature, and to generate a comparator trigger pulse if failing test vectors match the prior failure signature. The trigger pulse indicates that the test location of the DUT is a failed location.