Atomic layer deposition of SnS₂ film on a 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 back-end-of-line (BEOL) field effect transistor (FET). Among many 2D materials, tin disulfide (SnS2) is advantageous for low temperature processing due to a low melting point, which is a pre-requisite in the production of flexible and BEOL devices. However, this low temperature method produces poor crystallinity. Hence, many studies have aimed to improve crystallinity of SnS2 film for use in semiconductor industries. 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) for improved adsorption of precursors to the substrate before general deposition. The film quality was analyzed by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. These analyses showed a greater number of adsorbates after precursor pre-treatment, inducing a higher growth rate and better film crystallinity.