The problem of determining the roughness of the A model is used based on the SiO2/Si interface is treated. Fresnel formalism and scalar scattering theory. The resulting formulas express the diffuse reflectance as a function of the optical constants of the two materials, the oxide thickness and the rms roughness of the interfaces. Using the roughness values as adjustable parameters, quantitative information about the interface roughness is obtained from the diffuse reflectance spectra for an SiO2/Si double layer. Excellent agreement between calculated and experimental spectra is obtained for an rms roughness of 9.0 nm at the front surface and 2.2 nm at the oxide substrate interface for the case of a low-pressure low-temperature CVD film of SiO2 on Si.
© 1988 Optical Society of America
Original Manuscript: April 8, 1988
Published: November 15, 1988
A. Roos, M. Bergkvist, and C. G. Ribbing, "Determination of the SiO2/Si interface roughness by diffuse reflectance measurements," Appl. Opt. 27, 4660-4663 (1988)