Ten nanometers of oxides grown in a conventional diffusion furnace have been annealed at 1050 degrees C in the same diffusion furnace and in a rapid thermal reactor. Their interfacial electrical properties (V-FB and D-it at midgap) have been determined, and their breakdown quality has been assessed by means of both time zero and time-dependent dielectric breakdown (TZDB, TDDB) experiments. We observed overall improvement of the annealed samples over the control ones that can be explained by the stress relaxation the anneal step provided. In spite of its much shorter duration, however, the rapid thermal anneal (RTA) outperformed the furnace anneal, thus indicating that the improvement is beyond a conventional viscoelastic stress relaxation. In fact the samples that underwent the RTA process exhibited a distinct electron trapping reduction that may explain their better performance. The contradictory results recorded during this investigation between TZDB and TDDB measurements have been shown to arise from the different trapping behavior of the different samples considered.