Heavy arsenic doping of silicon by molecular beam epitaxy

As MOSFETs scale to deep-submicron dimensions, there has been an increasing demand for silicon epitaxial layers with abrupt doping profiles. For nanoscale devices, arsenic is an attractive n-type dopant because of its high solubility and low diffusivity, but suffers from surface segregation during epitaxy, making high- concentration incorporation with abrupt profiles difficult. In this paper we report results of arsenic incorporation in Si molecular beam epitaxy (MBE) using a unique combination of solid (As, Si) and gas (disilane) sources to achieve these goals.