摘要 |
PURPOSE:To exactly measure thickness of a thin film, by constituting so that a light reflected by the surface of a substrate which has formed the thin film on both its surfaces is made to pass through from a transmission part, and intercepting a light refleted by the opposite surface of the substrate, by a light shielding plate. CONSTITUTION:A white light emitted from a white light source 8 is reflected by a reflector 10 through a spectroscope 9, passes through a slit 5a of a light shielding plate 5, and is made incident at a 15 degree incident angle to a substrate 2 which has formed a thin film on both its surfaces. A light reflected by the lower surface of the substrate 2 passes through the slit 5a, and a light reflected by the upper surface is intercepted by the light shielding plate 5. The light which has passed through the slip 5a is made incident to a detector 12 through a reflector 11 and intensity of its light is recorded in a recording meter 13 as a function of spectral wavelength of the spectroscope 9. Since thickness of a film is measured by detecting only an interference light from a film to be measured, thickness of a thin film is measured exactly. |