The dielectric constant of porous polysilazane (PPSZ) film was as low as 2.2 owing to the high porosity and uniformity of the film. The copper silicide was found to form between Cu and the PPSZ film after annealing at 550 degreesC for 30 min due to the SiO desorption from PPSZ. The oxidation behaviors on broken PPSZ films catalyzed by copper silicide were found. The copper silicide reacts with oxygen to form Cu and SiO2 at room temperature. The leakage current of the broken PPSZ film after annealing at 550 degreesC for 30 min was found to decrease with exposure in air for a few days at room temperature. (C) 2004 Elsevier B.V All rights reserved.