Sb surface segregation during heavy doping of Si(100) grown at low temperature by molecular beam epitaxy

Sb surface segregation and doping during Si(100) molecular beam epitaxy at low temperature have been studied by depth profiling with secondary ion mass spectrometry, x‐ray photoelectron spectroscopy, and conductivity measurements. We find that at a growth temperature near 320 °C complete donor activation and doping densities near 5×10²⁰ cm^-3 are obtainable. For temperatures between 320–500 °C, measurements point to the existence of distinct surface segregation regimes. For dilute surface and bulk Sb concentrations the measurements reveal a region where the surface segregation is constant and bulk and surface concentrations are linearly related. For bulk concentrations near the solid solubility limit, the surface segregation increases rapidly with increasing bulk concentration for temperatures between 350–450 °C. Finally, for Sb‐saturated surfaces the surface segregation actually decreases, and doping levels exceeding the solid solubility limit are possible.