LASER BEAM TESTING ON FINISHED INTEGRATED CIRCUITS.

Today testing an integrated circuit needs the use of a one micron size laser probe. The reflected part of a laser beam focussed on a VLSI circuit allows us to form with a high magnification microscope, the image of an integrated circuit. The OBIC technique allows to directly observe an electrically active junction at the silicon substrate level of a circuit. These two visualization techniques are completed with mapping techniques which allows us to locate sensitive areas in VLSI circuits. Localization of marginal voltage defects and latch-up sensitive areas are the two main examples.