Failure analysis using ferroelectric liquid crystals

The complexity of present VLSI chips requires powerful tools to detect possible defects. For such a purpose, internal contactless testing methods such as electron beam or laser testing, have been developed to help the precise localization of the electrical defect. The aim of this paper is to describe the liquid crystals test method, used at the IBM COMPEC laboratory for failure analysis. The electro‐optical properties of these materials allow the visualization of electric signals on the chips surface.