Nondestructive Determination of the Composition and Thickness of Thin Films of Pyrolytically Deposited Borosilicate Glass by Infrared Absorption

Abstract

The compositions of thin films of pyrolytically deposited borosilicate glass were correlated with the infrared spectra of these films over the entire composition range. Although the composition has been related to the ratio, R, of the absorbance maximum at about 1300 cm⁻¹ to the maximum at about 1050 cm⁻¹, the relationship between R and composition was found to be dependent on deposition conditions for glasses of more than about 30 m/o (mole per cent) . Nevertheless, if ^R' is defined to be the ratio of the areas of the and bands, respectively, the relationship between R' and mole fraction is independent of temperature and other deposition conditions. The composition dependence of the integrated intensity of these bands as well as of film density and refractive index and the temperature dependence of composition and deposition rate were determined also.