Image formation properties of As40S20Se40 thin layers

摘要

The present paper is concerned with investigations of image formation properties of As$-40$/S$-20$/Se$-40$/ thin layers. Spectral dependence of the refraction index n of variously treated samples was estimated from optical transmission in the spectral region 400-2500 nm. The n energy dependence of variously treated samples was fitted by the Wemple-DiDomenico dispersion relationship and used to estimate the single-oscillator model parameters. It was found, that exposure, as well as annealing leads to the increase in n values over the all investigated spectral region. Changes of the parameters of the single-oscillator model induced by treatment are discussed on the base of photo- and thermally- induced structural changes, which were directly confirmed by Raman scattering measurements. Such photoinduced structural changes provide good etching selectivity of As$-40$/S$- 20$/Se$-40$/ layers in nonaqueous amine based solvents. The best obtained sensitivity values consisted of approximately 40 cm$+2$//J. Surface relief patterns that were fabricated have good surface quality.Diffraction efficiency values of holographic diffraction gratings obtained on the base of As$-40$/S$-20$/Se$-40$/ layers consisted of 60-70 percent.