The characteristic parameters of a solid-to-solid diffusion system are investigated. The net boron concentration of the pyrolytically deposited SiO2 films used as diffusion sources is determined by infrared spectrophotometry. The data of the diffused layer in Si are used to correlate the infrared absorption spectrum with the composition of the SiO2 films. The absorption cross section of the B-O oscillator is determined. The surface concentration and junction depth of the diffused layer in the Si are determined from the infrared absorption of the SiO2 film and by the four-point probe and bevelled-edge methods.

Boron and phosphorus atoms were implanted into pure pyrolytic SiO2 films, and their infrared absorption spectra were determined. The IR absorption bands of B-O and P-O bonds appeared in the spectra of the films, if the B and P ion doses were higher than 3*1016 atoms/cm2. The effect of heat treatment on the formation of B-O and P-O bonds from B and P atoms implanted into SiO2 films was examined. The results were used to determine the constant of the quantitative IR measurement of boron and phosphorus, as well as the absorption cross-section of the B-O and P-O bonds. The obtained constants of the B and P measurements, as well as the absorption cross-sections, were compared with those obtained by measuring the characteristics of diffused layers produced with pyrolytically doped oxide films.

The phosphorus concentrations of P-doped SiO2 films deposited on to Si wafers by pyrolysis have been determined by activation analysis and using the data of diffusion layer prepared by the doped SiO2 film in the Si substrate. Using these P concentrations and the P=O infrared (IR) absorption bands of the films the constant K' of the IR P determination has been calculated. Inversely, measuring the IR absorption band corresponding to the P=O groups and knowing the constant K' can give estimates of the surface concentration of the diffusion layer prepared by the SiO2 diffusion source and the p-n junction's depth. The values of the constant K'; for SiO2 films doped by triethylphosphate and POCl3 are significantly different, explained by the difference in the ratio of the concentration of P=O bonds to the concentration of P atoms for the two doping materials.