JP2870842B

PURPOSE:To simplify formation and measurement of a sample and to correctly quantitate the concentration of specific impurities by making a standard sample of a known concentration and converting the yield of secondary ions with respect to a sample to be measured to the concentration of the impurities. CONSTITUTION:An SiO2 thin film 2 and a polycrystal Si thin film 3 are formed on an Si basepiece 1. A P ion of an element to be measured is injected from the surface of the thin film 3 so that the concentration of ion at the interface between the thin films 2 and 3 becomes a predetermined value. Thus, a standard sample 4 having a known distribution of concentration is obtained. A concentration curve after the discontinuous correction is made at the interface between the thin films 2 and 3 is formed. Accordingly, even when a sample to be measured is in the layered structure of two or more kinds of material, a comparison between the secondary ion yield obtained by a mass spectrometer through SIMS method and impurities can be performed by one standard sample. Moreover, a standard sample can be obtained in a simplified manner and the concentration of impurities of a sample to be measured can be easily quantitated.