HYDROGEN DIFFUSIVITIES BELOW ROOM-TEMPERATURE IN SILICON EVALUATED FROM THE PHOTOINDUCED DISSOCIATION OF HYDROGEN CARBON COMPLEXES

We have evaluated hydrogen and deuterium diffusivities in silicon below room temperature (220-270 K) by analyzing the kinetics of photoinduced dissociation of a chemical etching introduced hydrogen (deuterium)-carbon complex. Under sufficiently strong illumination, the annihilation rate of the complex was proportional to the phosphorus density, indicating that the rate-determining step is the diffusion of hydrogen (deuterium) to phosphorus atoms. Applying the diffusion-controlled reaction theory, we have evaluated the diffusion coefficients as 7 X 10(-2) exp(-0.54 eV/kT) cm2 s-1 for hydrogen and 5 X 10(-3) exp(-0.49 eV/kT) cm2 s-1 for deuterium, being in good agreement with the extrapolation of the high-temperature diffusion data of A. Van Wieringen and N. Warmoltz [Physica 22, 849 (1956)].