Characterization of as-grown and annealed thin SiO2 films formed in 0.1 M HCl

Abstract

Anodic oxidation at constant voltage has been used to produce oxide films of thickness 10–440 Å on Si(100). The electrolyte was 0.1 M HCl. Both annealed and as-grown samples were characterized by ellipsometry and Fourier transform infrared spectroscopy (FTIR), as well as by etch rate measurements in dilute HF. For as-grown samples, the voltage dependence of the thickness was determined. FTIR results for the as-grown films showed that the properties were dependent on the oxide thickness and not directly on the formation voltage. These results also provided a basis of comparison for the annealed samples. Demonstrably higher quality oxide films were characteristic of the annealed samples in comparison to the as-grown samples. The higher quality of the annealed samples was confirmed by measurement of the etch rate.