Boron Diffusion in Amorphous Silica Films

The diffusion coefficients of boron in amorphous silica films have been determined over the temperature range from 1173 to 1373 K. The films were prepared by thermal oxidation of silicon substrates. Boron was incorporated into the films from boron vapor, the pressures of which were varied between and Pa. The diffusion coefficients were calculated from boron concentration profiles in the films measured using secondary ion mass spectrometry: , where R is . The diffusion coefficients were not dependent upon boron vapor pressures, i.e., the boron concentrations at the film surface. The discussion on the activation energy and chemical state analysis using x‐ray photoelectron spectroscopy offer the mechanism that boron diffuses through the silicon sites in the network of .