Optical contactless probing: an all-silicon, fully optical approach

With decreasing feature size and increasing chip densities, the classical mechanical probe approach for internal fault detection and functional testing faces increasing challenges. Contactless testing might resolve many of the challenges associated with conventional mechanical wafer testing. This article reviews and explains existing optical contactless technologies and introduces a new test methodology - a fully optical contactless testing technique. The proposed method´s uniqueness lies in the fact that it is a fully optical technique that uses visible light and is completely compatible with standard silicon IC processing. The technique produces results that demonstrate its feasibility and show its advantages over other optical contactless testing methods.