METHOD FOR MEASURING SURFACE LEAKAGE CURRENT OF SAMPLE

摘要

PROBLEM TO BE SOLVED: To highly accurately measure a surface leakage current of a sample without removing an adhering substance on the sample surface at a different facility beforehand, and enable it to be confirmed whether or not the adhering substance on the sample surface is completely detached. SOLUTION: A pair of electrodes 52 and 54 are formed to the surface of the sample 50. In a state with a voltage impressed between the pair of electrodes 52 and 54, an energy ray 62 is irradiated to a region of the sample surface between the electrodes 52 and 52, whereby the adhering substance 60 is detached from the sample surface. A current flowing between the electrodes 52 and 54 is measured while the energy ray 62 is being irradiated. The surface leakage current flowing through the adhering substance 60 can be observed while the adhering substance 60 is present. The surface leakage current caused by the adhering substance 60 disappears when the adhering substance 60 is completely detached. Therefore, it can be confirmed that the adhering substance 60 is completely detached at a time point when the surface leakage current resulting from the adhering substance 60 disappears. Thereafter, the surface leakage current originating from the sample can be measured by stopping irradiating the energy ray 62.