A small gap structure was designed to examine surface chemistry aspects of film deposition for fluorocarbon (FC) plasmas produced using both inductively coupled plasma (ICP) and capacitively coupled plasma (CCP) systems. The small gap structure provides a completely shadowed region without direct ion bombardment. Neutrals diffuse into this region and form a fluorocarbon layer. The lack of ion bombardment increases the retention of the chemical structure of the FC film precursors. The surface chemistry of FC film deposited in this region is compared with film deposited in the region exposed to direct ion bombardment. For films deposited in the exposed region, x-ray photoelectron spectroscopy analysis shows that CF2 is the dominant chemical bond for pure C4F8 in both ICP and CCP systems. For C4F8/Ar discharges, C-C bonding is dominant for the polymer formed in the ICP system, whereas CF2 species are dominant for films deposited in the CCP system. In the completely shadowed region, CF2 bonding is dominant for FC films deposited using C4F8 and C4F8/Ar discharges produced in both ICP and CCP systems. The film thickness and F/C ratios of fluorocarbon films formed in the small gap structure using C4F6 and C4F8 ICP discharges were also compared. Effects of Ar addition, gap height, and bias voltage on surface conditions of fluorocarbon deposition were studied. In addition, a simple model based on Knudsen diffusion was developed to describe the film thickness profile in the completely shadowed region. (c) 2005 American Vacuum Society.