A PROBE OF CHEMICAL OXIDE GROWTH CONDITIONS

摘要

Silicon oxides on bare silicon wafers are often formed in either aqueous ozone or caustic solutions of hydrogen peroxide. We have evaluated these oxides, grown in a temperature range from 20°C to 70°C, using photothermal reflection spectroscopy (Therma-Probe). We find that this method is very sensitive to the type of oxide grown; for example, whether it is an SC1 oxide or ozone oxide. We are able to observe the replacement of one chemical oxide by another. In addition, the magnitude of the Therma-Probe signal is sensitive to the temperature at which the SC1 oxide is grown. Since the Therma-Probe signal has been used to measure residual stress in bulk silicon, these results suggest that chemical oxides grown by different chemistries and temperatures may leave significantly different levels of residual stress in the first few layers of the substrate silicon.