The prospects of obtaining desired surface-mediated characteristics while retaining bulk-mediated physical properties and avoiding potential environmental issues with wet chemical technology lends considerable appeal to photochemical approaches. We investigated the response of poly(ethylene terephthalate) to 172 nm UV from a xenon excimer lamp in the absence of oxygen, using XPS, ToF/SIMS, and AFM. The main effects are increasing loss of a C=O moiety and carboxylic acid production without effect on topography upto a total fluence of 16 J/cm(2). Above this level no further change in surface chemistry was evident, but surfaces became rougher, suggesting the onset of etching. (C) 2004 Elsevier B.V. All rights reserved.