The effects of plasma exposure and vacuum-ultraviolet (VUV) irradiation on photopatternable low-k (PPLK) dielectric materials are investigated. In order to examine these effects, current-voltage measurements were made on PPLK materials before and after exposure to a variety of inert plasma-exposure conditions. In order to examine the effects of photon irradiation alone, PPLK samples were also exposed to monochromatic synchrotron radiation with 10 eV photon energy. It was found that plasma exposure causes significant degradation in electrical characteristics, resulting in increased leakage-currents and decreased breakdown voltage. X-ray photoelectron spectroscopy measurements also show appreciable carbon loss near the sample surface after plasma exposure. Conversely, VUV exposure was found to increase breakdown voltage and reduce leakage-current magnitudes. © 2013 AIP Publishing LLC.