Kinetics driving nanocomposite thin-film deposition in low-pressure misty plasma processes
Simon Chouteau, Maria Mitronika, A. Goullet, Mireille Richard‐Plouet, Luc Stafford, A. Granier
Abstract
Abstract Mist-assisted methods have recently attracted much attention for plasma deposition in high-quality (multi)functional thin films. However, very little is known on plasma interactions with misted colloidal solutions and their role in plasma process kinetics. Time-resolved optical diagnostics have been carried out to study the deposition of TiO 2 –SiO 2 nanocomposite thin films in low-pressure oxygen-argon plasmas with organosilicon precursors and TiO 2 suspensions. Each pulsed injection of the dispersion was followed by a pressure rise due to solvent evaporation. This caused a significant reduction in the electron temperature and density, which mitigated matrix precursor fragmentation and SiO 2 deposition as TiO 2 nanoparticles were supplied to the film. Comparing injections with and without nanoparticles, misty plasma effects were dominated by plasma droplets rather than plasma-nanoparticle interactions. Successive matrix-rich and nanoparticle-rich deposition steps were confirmed by in situ spectroscopic ellipsometry.