Effects of Ammonia Anneal on Electron Trappings in Silicon Dioxide

After annealing of silicon dioxide in ammonia at elevated temperature, a large increase in electron traps was observed. The dominant electron trap has a capture cross section of approximately 2 x 10–17 cm2 and the volume density of the trap is 2 x 1018/cm3. From photo I-V measurements, it was shown that the traps are distributed in the bulk of the oxide. This increase in electron traps can be used to explain the improvement in breakdown of oxides reported earlier after similar anneal in ammonia. This electron trap may be due to the presence of oxynitrides. However, infrared measurements show an increase of bonded OH in the film and the capture cross section of the trap is the same as that due to bonded OH. © 1982, The Electrochemical Society, Inc. All rights reserved.