On the nature of the kink in the carrier profile for phosphorus-diffused layers in silicon

The mechanism of formation of the kink in the impurity profile of phosphorus-diffused layers in silicon is shown to be related to the ``tail'' that is formed during low-temperature heat treatments. The concentration at which the tail is formed is a function of temperature with an activation energy of 0.79 eV. The enhanced diffusion which gives rise to the tail depends on processes occurring in the high-concentration region. A complex model is required to explain all of these results.