The electron trapping behavior of SiO2 films implanted with Al has been studied by Johnson, Johnson, and Lampert1 and they conclude that the trapping is occuring in damage sites resulting from the implantation. They used annealing temperatures up to 600C. We find that the trapping is reduced further as we increase the annealing temperature up to 1050C. We have characterized the traps and find that the predominate traps have cross sections of 1.26 × 10-16 and 1.4 × 10-17cm2. The trapping is proportional to the fluence and is not a strong function of the measuring temperature. The centroid of the trapped charge is close to the centroid of the implanted Al as predicted by the LSS theory6. © 1977 American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.