Surface and interfacial roughness

Ellipsometry can be sensitive to layers of matter only one atom thick. For example, oxidation of freshly cleaved single-crystal graphite can be monitored from the first monolayer and up. The best thicknesses for the ellipsometric study of thin films are between about 1 nm and 1000 nm. Although the spectra become complicated, films thicker than even 1 pm can be studied. Flat planar materials are optimum, but surface and interfacial roughness can be quantitatively determined if the roughness scale is smaller than about 100 nm. Thus ellipsometry is ideal for the investigation of interfacial surfaces in optical coatings and semiconductor struc-... 

Oxidation behavior of the TiSi2 on silicon is the final concern.22 A good deal of surface and interfacial roughness was observed on the films that had been put down on silicon and wet oxidized for one hour at 800°C. The oxide layer was about 1800 A thick. Further study of the quality of the oxide layer will be necessary before this film can be considered for device applications. 

---