Interface Reactions of B[sub 2]O[sub 3]-Si System and Boron Diffusion into Silicon

The interface reactions of the system were studied by infrared spectroscopy, electron and x‐ray diffraction, etc. The compound, which was produced at the interface in the temperature range of 900°–1200°C closely resembled or in the diffraction measurements. The growth rate of silicon oxide, produced in the interface in an oxygen atmosphere, was several times as fast as that in a nitrogen atmosphere. These growth rates are much faster than the ordinary growth rate of silicon oxide in a dry oxygen atmosphere. From these data, the rate constants of growth of silicon oxide were estimated, assuming the relationship of the parabolic oxidation. Comparing these results with the doping amount of boron in silicon, it was confirmed that the rate‐determining step of the transfer of boron into silicon was classified by whether the above Si‐B compound was present or not.