Submicron thickness calibration of vapor‐deposited SiO₂ films by infrared spectroscopy Available to Purchase

Infrared transmission spectra of a series of SiO₂ films vapor deposited on silicon from SiH₄ and O₂ at 450 °C have been studied as a function of film thickness in the submicron range from 1000 to 9000 Å. Absorbances of band maxima observed in the frequency range 250–1400 cm⁻¹ are shown to obey the Lambert‐Bouguer's law in both as‐deposited and heat‐treated (800–1200 °C) materials. Apparent absorption coefficients calculated for the transmission mimima at 1060, 800, and 450 cm⁻¹ are 2.5 ± 0.1 × 10⁴, 0.24 ± 0.02 × 10⁴, and 0.74 ± 0.02 × 10⁴ cm⁻¹ for as‐deposited films and 3.4 ± 0.1 × 10⁴, 0.34 ± 0.02 × 10⁴, and 1.06 ± 0.02 × 10⁴ cm⁻¹ for heat‐treated films, respectively. The thickness of SiO₂ films as‐deposited at 450 °C as well as heat treated to 800 °C and above can be determined nondestructively using the present absorbance data.