FORMATION OF MULTILAYER CHALCOGENIDE GLASS FROM SOLUTION

Abstract

Chalcogenide glasses of As2S3 and As2Se3 compositions were dissolved into various solvents with concentrations ranging from 0.05-0.4 g/ml. These solutions are then spin coated at speeds ranging from 500-3000 RPM. Single layer films can be made with a range of film thicknesses (100-1000nm). Stacking multiple layers of As2S3 and As2Se3 using a standard -amine solution ethylenediamine failed. -Amine solvents tend to redissolve previous layers thus generally are not suitable for making multilayer thin films. A method was found to dissolve As2S3 in dimethylacetamide, in which is it normally insoluble. This solution can be used to deposit multiple layers of As2S3 on top of each other with a linear relationship between film thickness and number of layers. The As2S3 solution in dimethylacetamide was also able to deposit As2S3 on other chalcogenide glasses. Butylamine was also found to be a solvent that can stack As2Se3 layers but with limited thickness due to low solubility. In the formation of multilayer films, a trend is observed that multilayer films have lower surface roughness than a single layer film counterpart.