RAPID THERMAL ANNEALING OF LOW-TEMPERATURE CHEMICAL VAPOR-DEPOSITED OXIDES

We report the effects of rapid thermal annealing of low-temperature oxides grown using chemical vapor deposition. Oxide quality is monitored with ellipsometry and IR spectroscopy by following changes in the refractive index, stretching peak frequency of the Si-O-Si bond, and stretching peak width as a function of gas composition and final anneal temperature. Electrical testing for positive charge is used to correlate electrical characteristics with the reported physical properties. Our results show improved oxide quality with increasing oxygen content and annealing temperature, and emphasize the importance of high-quality oxide spacers from a standpoint of both hot electron degradation and source/drain engineering. Process improvements uncovered in this work are suggested as a means for reducing suboxide character in low-temperature CVD films grown with fast deposition rates.