Contactless characterization of semiconductor devices using surface photocharge effect

A technique for evaluating electrical properties of semiconductor wafers and devices using the surface photocharge effect caused by laser radiation is proposed. The measurement setup used in the experiments is presented along with some preliminary results. In particular, experimental results are presented for MOS devices on silicon under bias. It is possible to distinguish from the experimental plots the depletion, accumulation, and inversion regions of the device. Information could be obtained from these curves in a manner analogous to CV plots.<
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