High Rate MW-Plasma-CVD Deposition for Hard Coatings on Large PC Glazing: First Results Make TMCTS a Promising Precursor Candidate

摘要

In general microwave plasma processes have even higher plasma density and faster reaction rates but showed lower uniformity in large area applications. This can be overcome by an assembly of a couple of linear "PlasmaLines" to create a large-scale planar plasma source. The influence of standard plasma parameters onto the most important required layer properties were evaluated in a lab (0.0225 m~2) and a large area coating system (0.6 m~2). To increase the efficiency a second approach was done by evaluating the influence of the chemical structure of siloxane precursors. Tetramethylcyclotetrasiloxane (TMCTS) in general shows a similar behavior to plasma parameters as HMDSO, OMCTS and TMDSO. Coating properties are found equal: haze, transmission, adhesion and scratch resistance - ΔHaze 1.8% - are fulfilling the specifications for glazings. TMCTS shows remarkable deposition rates: nearly 12 μm/min, but with a large spatial nonuniformity, generated by its high reactivity. Further benefits and challenges of this exceptional precursor are discussed.