AlSixOy films with very good uniformity were deposited by plasma-enhanced atomic layer deposition (PEALD). Although the SiO2 PEALD failed at 150 degrees C, Si atoms could be incorporated to form AlSixOy films when AlO and SiO subcycles were alternately performed. The catalytic effect of AlO films permits Si atoms to be incorporated into the films. Hence, it is possible to increase the Si content from 0 to 11.6 atom % by increasing SiO subcycles. The degradation of leakage current for AlSixOy films did not occurr compared to Al2O3 films. (c) 2005 The Electrochemical Society.