Imaging Latch-up Sites in CMOS Integrated Circuits Using Laser Scanning

A novel approach to using laser scanning to analyze latch-up sites in complementary metal-oxide semiconductor (CMOS) integrated circuits (IC´s) has been developed. The technique employs a continuous wave (CW) laser beam scanned across a CMOS IC as the power to the IC is modulated. Signals corresponding to latch-up currents are detected with a lock-in amplifier and are used to produce a two-dimensional image of latch-up sites on a high resolution monitor.