Arsenic out-diffusion during TiSi2 formation

Abstract
The behavior of implanted As atoms during high‐temperature (800–900 °C) TiSi2 formation was investigated by helium backscattering. A significant As loss was observed during TiSi2 formation by vacuum furnace annealing. The main factors influencing the As loss were the initial As profiles and Ti film thickness. Most of the As loss was caused by rapid As out‐diffusion through the TiSi2 layer; the remaining As atoms were only observed in the Si substrate after TiSi2 formation. As long as the As distribution was deeper than the TiSi2 layer, the loss of As atoms was kept to a minimum. Careful selection of the As implantation energy and the Ti film thickness can achieve high As concentration at the TiSi2/Si interface.