Surface Analysis of Fluorocarbon Thin Films with XPS and Ellipsometry:Ellipsometric measurements were performed at λ= 632.8 nm with a Gaertner L116C ellipsometer. XPS characterization was carried out using a Kratos Ultra System with a monochromatic Al K α X-ray source. Spectra were acquired in the constant analyzer energy mode using pass energies of 160 eV for survey spectra and 20 eV for high Table 1. For the ellipsometry measurements, the complex refractive index for the transparent fluorocarbon polymer was taken to be n=1.4 and k=0. 1 The substrate refractive indices for the model surfaces were taken to be: Si (n=3.85, k=0.2), Au (n=0.13, k=3.16) and HOPG (n= 2.91, k=1.71). 2 The model used to