Modeling of hydrogen diffusion inn- andp-type silicon

A model is proposed to describe the behavior of hydrogen in silicon at moderate temperatures. It is assumed that H has both a donor and an acceptor level in the band gap, and thus it can exist in the three charge states ${\mathrm{H}}^0$, ${\mathrm{H}}^{+}$, and ${\mathrm{H}}^{\mathrm{-}}$. Its motion is slowed down by the formation of ${\mathrm{H}}_2$ molecules as well as by interactions with the dopant atoms. Good simulations are obtained in both n- and p-type Si for various doping levels. The fitted diffusivity of neutral hydrogen is in agreement with the extrapolated high-temperature data.