JUNCTION-PHOTOVOLTAGE METHOD AND APPARATUS FOR CONTACTLESS DETERMINATION OF SHEET RESISTANCE AND LEAKAGE CURRENT OF SEMICONDUCTOR

A junction-photovoltage method and apparatus for contactless determination of an electrical/physical parameter of a semiconductor structure having at least one p-n junction located at a surface is disclosed. In one aspect, the method includes illuminating the surface with the p-n junction with a light beam of a first wavelength to create excess carriers at the surface. The method also includes modulating the light intensity of the light beam at a single predefined frequency. The method also includes determining a first photo-voltage at a first position inside the illuminated area and a second photo-voltage at at least a second position outside the illuminated area. The method also includes calculating an electrical/physical parameter of the semiconductor structure based on the first and second photo-voltage.