The surface recombination velocity (S-0) in n-type Si (n-Si) wafers has been reduced below 0.1 cm/s by dint of positive fixed charges created by alumina (AlOx) films deposited at a film-temperature of 230 degrees C by catalytic chemical vapor deposition (Cat-CVD) using trimethyl aluminum (TMA) and O-2. Positive fixed charges of the order of 1012 charges/cm(2) can be created in AlOx films deposited under O-2/TMA flow-rate ratios in the range of 3.5-6.5. The extremely small S-0 has been confirmed to be obtainable mainly due to a band bending effect brought about by the positive charges. The polarity and amount of the fixed charges can be determined by the flow-rate ratio of O-2/TMA. (C) 2014 Elsevier B. V. All rights reserved.