Visible light reflectometry

We developed an approach for analysis of reflectance spectra with bands of interference origin, for thin porous nanostructured layers on silicon wafers and made the automatic reflectometry equipment to examine optical characteristics (reflectance coefficient, refractive index) in the visible, near- infrared and mid- infrared range. The method is applied to por-Si, por-CoSi2 and por-A Os layers on c-Si substrate. The reflectance spectra, recorded at different light incidence angles permit to detect both the refractive index and layer thickness simultaneously. TEM, AFM, IR spectroscopy investigations of these layers confirmed the presence of Si nanocrystals. 

Layer-by-layer (LbL) technique can be apphed to form the smooth multilayer films based on PDMS. Using this method the covalently bound, robust multilayer films of optical quality were obtained from 3-aminopropyl-terminated homobifunctional PDMS and poly(ethylene-alt-maleic anhydride) (PEMA) on silica surfaces [48]. Due to the differences in solubility of the polymers used, the polymer layers were deposited from different solvents PEMA layers were prepared from tetrahydrofuran solution, while the PDMS layers were deposited from toluene. The multilayer assemblies show a solvent memory for swelling and de-swelling when immersed in the corresponding solvent for each polymer. Films prepared under these conditions were smooth up to 60 nm of thickness, as demonstrated by small angle X-ray reflectometry, and do not visibly scatter the incident light. Thicker films showed very homogeneous... 

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