| 摘要 |
PURPOSE:To enhance measuring accuracy by calculating the thickness of a thin film by simple calculation, by using a polarized wave to be irradiated having a short wavelength transmitted through a layer to be measured but absorbed by the lower side layer under the layer to be measured. CONSTITUTION:An incident polarized light 8 is reflected from the surface of a thin film to obtain Ep-light and the light penetrated into said film 11 is reflected by the boundary surface with a substrate 10 to obtain Es-light to form reflected light 9. As the light reaching to the interface P between the substrate 10 and the thin film 11, polarized light having a short wavelength is selected so as to be absorbed by the substrate 10. For example, when a polycrystalline Si-oxide film A with a thickness of 1,000Angstrom and a polycrystalline silicon film B with a thickness of 5,000-7,000Angstrom are laminated and polarized light with a short wavelength of 3,000-4,000Angstrom is used, the polarized wave penetrated into the film B is absorbed and no reflected wave is generated. By this method, the thickness of the film A can be detected precisely by emitted light 9. |
