Si epitaxy is strongly affected by the presence of an adsorbate (surfactant). We have examined both film quality and dopant incorporation in homoepitaxy for Sb, As, and Ga terminated Si(111). The efficency of site exchange between Si and adsorbate depends sensitively on binding energy and binding geometry of the adsorbate. For a weakly bound adsorbate (Ga or Sb), there is no inhibition of epitaxy, but a strongly bound adsorbate (As) kinetically inhibits growth. ©1995 American Institute of Physics.