Nanolaminates enable a new class of optoelectronic structures that are ultra lightweight, dimensionally stable, and have low cost with increased durability and flexibility. They are integral components in various applications serving as advanced dielectrics, flexible barrier coatings, and as optical components. In this work plasma enhanced chemical vapor deposition (PECVD) is employed to deposit functional polymer thin films on flexible substrates in order to make hybrid organic-inorganic nanolaminates for the applications described above.

 

Silicone-like coatings were deposited using hexamethyldisiloxane (HMDSO) and oxygen as precursors at room temperature. Film composition was assessed by spectroscopic ellipsometry and FTIR. A wide range of coatings, from inorganic SiO2-like films to flexible polymeric films could be deposited by appropriate control of parameters including the O2/HMDSO ratio, rf power, and working pressure. In this work we report on how these variables impact deposition rate, film composition, and nanolaminate performance. Growth rates as high as 100 nm/min were obtained, and crack free silica and polymeric films have been deposited on polyethylene.

 

For the production of organic-inorganic nanolaminates, two approaches were used for the formation of the inorganic layer. In one case HMDSO was used for deposition of both the silicone- and silica-like layers. In this case, the flowrate of HMDSO was held constant while other variables (power/O2 flowrate) were adjusted. In the second case, the inorganic layer was aluminum oxide that was formed using tri-methyl aluminum (TMA) and oxygen at room temperature. Self-limiting growth of alumina (~Å/pulse) was achieved by both plasma-enhanced ALD and pulsed PECVD. No impurities were detected in Al2O3 by FTIR by either technique under optimum conditions. Nanolaminates were constructed as a function of dyad composition and total number of dyads. In this paper we compare the performance of these various nanolaminates with respect to metrics such as adhesion and barrier properties.