Mist chemical vapor deposition of MoO2 thin films

Abstract

Molybdenum dioxide (MoO2), which exhibits both high chemical stability and high electrical conductivity, has been studied for various applications, e.g. as a photocatalyst, an active material for secondary batteries, and the capacitor electrode of dynamic random access memory devices. MoO2 films are mainly fabricated by vacuum processes, which incur a high manufacturing cost. In this study, we fabricated MoO2 thin films by mist chemical vapor deposition. Since this method does not require vacuum or a volatile precursor, the processing cost is reduced. Examination of the films deposited at various positions in the furnace at different furnace temperatures revealed that smooth MoO2 films composed of densely packed crystal grains with a constant thickness of 200 nm can be obtained over a wide area of >30 cm2 at a furnace temperature of ~480 °C. The films showed low electrical resistivity of 2 × 10−3 Ω cm. Thus, this study provides a low-cost method for the fabrication of MoO2 thin films.