Evaluation of electrical contact area between metal and semiconductor using photo-induced current

Photo-induced current (PIC) is produced from excited electrons and holes in a semiconductor by irradiation of laser light. Since the intensity of the PIC depends on the traveling distance of carriers, measuring current between a metal and a semiconductor can be utilized for analyzing electrical contact. The spatial resolution of the PIC depends on the attenuated length and the thickness of the semiconductor, and its intensity is proportional to the contact pressure. By scanning laser light, we obtained two-dimensional distribution maps of electrical contacts between solids.