Single-chamber plasma enhanced chemical vapor deposition of transparent organic/inorganic multilayer barrier coating at low temperature

Deposition of organic/inorganic multilayers is usually carried out by two different process steps by two different deposition methods. A single-chamber process for the deposition of multilayer stacks can make the process and deposition system simpler. In this work, SiOCH and plasma-polymerized methylcyclohexane (pp-MCH) films and their multilayer stacks for application to transparent diffusion barrier coatings were deposited in a single low-temperature plasma enhanced chemical vapor deposition reactor using hexamethyldisilazane/ N2 O O2 Ar and methylcyclohexane/Ar mixtures for SiOCH and pp-MCH layers, respectively. The deposition rates of the SiOCH and pp-MCH layers were increased with increasing the N2 O: O2 gas flow ratio and rf plasma power, respectively. Oxygen concentration in the SiOCH films was decreased and carbon and hydrogen incorporation was increased when increasing the N2 O: O2 gas flow ratio from 0:1 to 3:1. In this work, the water vapor transmission rate of polyester sulfone substrate could be reduced from a level of 50 (bare substrate) to 0.8 g m2 day after deposition of a pp-MCH/SiOCH/pp-MCH multilayer coating.