CALIBRATION OF WAFER SURFACE INSPECTING DEVICE

PURPOSE:To contrive so as not to be confused an adhered foreign substance with intentional foreign substances provided on a calibration wafer and to make it possible to prevent the lowering of the calibration accuracy even though the foreign substance is adhered on the wafer by a method wherein an antireflection film is provided on the surface of the substrate of the wafer. CONSTITUTION:An antireflection film 23, which consists of Si dioxide or Si nitride (SiN) and acts as reflection prevention to the wavelength of the incident light of a wafer inspecting device, is formed on a substrate 21, which consists of a clean Si wafer, of a calibration wafer and moreover, an Si nitride film or an Si dioxide film (The material is made to differ from that of the film 23.) formed thereon is patterned and a plurality of intentional foreign substances 22 distributed sparsely, such as in the form of a 1-mm interval matrix, are formed. The thickness of the film 23 is about 1000 Angstrom in the film consisting of Si dioxide in case the wavelength of the incident light is 6330 Angstrom (The light source is a helium-neon laser.) and is about 800 Angstrom in the film consisting of Si nitride. When this calibration wafer is used, an adhered foreign substance adhered on the film 23 is detected very small than its actual size in a state to say that even a big foreign substance of 2 mum, for example, is detected as a foreign substance of 0.4 mum.