Arsenic doping kinetics in silicon during gas source molecular beam epitaxy

Abstract

Arsenic doping from arsine during Si gas source molecular beam epitaxy (GSMBE) has been investigated. The As concentration in the epitaxial film has been measured by secondary ion mass spectroscopy (SIMS) and electrochemical capacitance-voltage (eCV) analysis. It has been found to relate to the surface coverage through a segregation process, while the surface coverage itself is determined by surface adsorption/desorption kinetics, whose dependence on the AsH3 flux indicates a non-integral-order desorption process of As from Si(100) surfaces. The surface coverage of arsenic is found to decrease the growth rate of Si from Si2H6, which can be used as a measure of As surface concentration. This enables segregation parameters such as the segregation ratio and the Gibbs energy for segregation to be extracted and they are shown to be in good agreement with previously reported results. © 1998 Elsevier Scieace B.V.