Atomic layer deposition of SnS2 film on precursor pre-treated substrate

Abstract

Two-dimensional (2D) materials are attracting attention because of their outstanding physical, chemical, and electrical properties for applications of various future devices such as BEOL FET. Among many 2D materials, tin disulfide (SnS2) material is advantageous for low temperature process due to low melting point that can be used for flexible devices and back-end-of-line (BEOL) devices that require low processing temperature. However, low temperature synthesis method has a poor crystallinity for applying to various semiconductor industries. Hence, many studies of improving crystallinity of tin disulfide film are studied for enhancing the quality of film. In this work, we propose a precursor multi-dosing method before deposition of SnS2. This precursor pre-treatment was conducted by atomic layer deposition (ALD) cycles for more adsorption of precursors to the substrate before deposition. The film quality was analyzed by X-ray diffraction, Raman, transmission electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy. As a result, more adsorbates by precursor pre-treatment induce higher growth rate and better crystallinity of film.