Reactive sputtering deposition of plasma polymerized nylon films with embedded NHx groups

Abstract

Reactive magnetron sputtering deposition of plasma polymer film enriched by nitrogen-containing functional groups (NCFGs) was investigated. The main goal of our research is to obtain plasma polymerized nylon films prepared by rf magnetron sputtering with embedded –NHx functional groups in its volume. Those films can be used as “storage environment” for many chemical substances (for example, antibiotics) that need the presence of chemical grafts. Films were prepared in ternary process gas mixture of Ar (carrier gas), and N2:C2H2 (reactive component). We found that a small amount of acetylene added in the process gas results in an increased amount of NCFGs while keeping the deposited film stable in aqueous environments. However, an enhanced amount of acetylene in the process gas, above some certain limit, causes target poisoning and suppression of the nylon sputtering which practically results in the conversion of the deposition process to PECVD. When the deposition was done in a reactive atmosphere only (N2:C2H2), the required optimum flow of acetylene to incorporate maximum NCFGs into the film volume raised, but it had a negative effect on the film stability in water.