Influence of the Substrate Temperature on the Growth Mechanism of Allylamine Plasma Polymer Films

ABSTRACT This work aims to investigate the impact of the substrate temperature on the growth mechanism of allylamine‐based plasma polymer films (PPF). A comprehensive study of the PPF physicochemical properties, including the mechanical properties, the glass transition temperature, the chemical composition, the cross‐linking degree and the deposition kinetics, is performed and correlated to plasma chemistry. As the substrate temperature evolves from ‐10°C to 45°C, the glass transition temperature is observed to increase from 75°C to 230°C. This evolution is correlated to an increase in cross‐linking degree, modulated by the energy density brought by ion bombardment during film growth. The energy density is, in turn, significantly influenced by the deposition kinetics which strongly depend on the thermal conditions of the substrate, as evidenced by the growth rate decrease from 5.4 to 1.6 nm/min with the substrate temperature. Similarities are observed with another allyl‐based PPF family, suggesting a comparable growth mechanism but distinct film properties attributed to differences in growth rate. Overall, this study highlights the combined role of precursor chemistry and substrate temperature as key parameters for fine tuning of plasma polymer film properties.