Copolymers containing polyhedral oligomeric silsesquioxane (POSS) pendant groups and various acrylate type monomers are studied by x-ray photoelectron spectroscopy. These copolymers have potential application as bilayer resist material for next generation lithography. Two methods are used in order to characterize resist surfaces, angular resolved XPS and inelastic background signal quantification (Tougaard method). The existence of a surface layer rich in POSS is proven. About 1.5 nm thick, this layer stands above a material with uniform POSS concentration. Evaluation of POSS concentration depth profiles shows that surface segregation depends on the polymer comonomers and on the silicon content. (C) 2004 American Vacuum Society.