Characterization of thin-film interference effect due to surface roughness

• Published in: Japanese Journal of Applied Physics Vol. 34; no. 7A; pp. 3754 - 3758
• Main Authors: NAGATA, H, YAMAGUCHI, A, KAWAI, A
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 1995
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Metals. Metallurgy; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optical properties of specific thin films; Optical properties of specific thin films, surfaces, and low-dimensional structures; Physics; Thin films; Thickness; Reflectivity; Size effect; Interference; Roughness; Surface properties; Resist; Aluminium; Solid-solid interfaces; Experimental study
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/jjap.34.3754

The normal and diffuse reflectivity from a resist/aluminum system were measured with various resist thicknesses. The average surface roughness σ a of aluminum surfaces varied from 5.5 to 10.5 nm upon changing the sputtering conditions. The diffuse reflectivity at the air/aluminum interface increases with surface roughness. This tendency is enhanced as the wavelength of incident light decreases. The interference effect for the resist/aluminum system decreases as the surface roughness increases. This tendency is enhanced when the resist absorptivity decreased. These results are analyzed with using the help of the “Swing” model.