Effect of Substrate and Annealing Ambient on the Conductivity of Sputtered MoSi2 Ceramic Thin Film

Abstract

In this work, molybdenum disilicide (MoSi2) ceramic thin films were deposited by DC magnetron sputtering on different types of substrates (quartz, glass, p-type silicon, n-type silicon, and barium strontium titanate (BST) buffer layer deposited on silicon). The films were annealed under various ambient conditions (air, N2/99.999%, N2-H2/95–5%) at various annealing times (10–90 min) and temperatures (400–1100°C) to enhance their crystallinity and improve their conductivity. The tetragonal crystal phase, which is the most conductive and stable phase of MoSi2 thin films, was obtained on an n-type silicon substrate that was annealed at 1100°C for 90 min in an atmosphere with pure nitrogen gas flux of 200 L/h. The sheet resistance of the MoSi2 thin films was 0.876 Ω cm−2. The films exhibited a homogeneous glossy metallic surface with surface roughness of 0.35 nm and 3.81 nm for amorphous and annealed thin films, respectively. The high conductivity obtained in this work, in addition to the extraordinary material properties of the MoSi2 ceramic thin film, makes it an attractive candidate for remarkable device applications because of the thermal stability of film conductivity.