All-silicon optical contactless testing of integrated circuits

A novel approach for replacing mechanical probes used for wafer level testing with an optical contactless method for the application and extraction of test vectors from advanced silicon integrated circuits (ICs) is described. Experimental results demonstrate its feasibility, using a novel silicon light-emitting diode (LED) and silicon light sensors fabricated on the IC. The proposed method uses visible light and device structures that are completely compatible with standard silicon IC processing. The optical test-head is inexpensive, fabricated with standard microscope optics, and allows the simultaneous use of mechanical probes for power and other signals.