We have successfully demonstrated that high quality and high dielectric constant layers can be fabricated by low temperature photo-induced or -assisted processing. Ta2O5 and ZrO2 have been deposited at t＜400 ℃by means of a UV photo-CVD technique and HfO2 by photo-assisted sol-gel processing with the aid of excimer lamps. The UV annealing of as-grown layers was found to significantly improve their electrical properties.Low leakage current densities on the order of 10-8 A/cm2 at 1 MV/cm for deposited ultrathin Ta2O5 films and ca. 10-6 A/cm2 for the photo-CVD ZrO2 layers and photo-irradiated sol-gel HfO2 layers have been readily achieved. The improvement in the leakage properties of these layers is attributed to the UV-generated active oxygen species O(1D) which strongly oxidize any suboxides to form more stoichiometric oxides on removing certain defects, oxygen vacancies and impurities present in the as-prepared layers. The photo-CVD Ta2O5films deposited across 10. 16-cm Si wafers exhibit a high thickness uniformity with a variation of less than ±2.0% being obtained for ultrathin ca. 10 nm thick films. The lamp technology can in principle be extended to larger area wafers, providing a promising low temperature route to the fabrication of a range of high quality thin films for future ULSI technology.