PLASMA POLYMERIZATION OF ALLYLAMINE/3-AMINOPROPYLTRIETHOXYSILANE MIXTURES - SURFACE NITROGEN CONTROL

A study has been conducted to determine the effects of gas-feed composition and RF power on the deposition rate and on the surface nitrogen content of thin films produced by plasma polymerization of allylamine/3-amino-propyltriethoxysilane (AA/3-APTS) mixtures. It has been found that while the deposition rate decreases slightly by increasing the AA content in the mixture, the surface nitrogen content, determined by XPS as N : Si molar ratios, increases up to a value of 8 : 1. Moreover, the nitrogen increase is not linear with the AA concentration and a maximum in the N/Si values is found for AA/APTS ratios close to 3 : 1, at all RF powers. The discussion on the polymerization mechanism for the mixture is based on evaluating and combining the behavior of each component, when plasma-polymerized alone in similar conditions.