Epitaxial Si(001) grown at 80-750 °C by ion-beam sputter deposition: Crystal growth, doping, and electronic properties

Epitaxial undoped and Sb-doped Si films have been grown on Si(001) substrates at temperatures T_s between 80 and 750 °C by ultrahigh-vacuum Kr⁺-ion-beam sputter deposition (IBSD). Critical epitaxial thicknesses t_e in undoped films were found to range from 8 nm at T_s=80 °C to >1.2 μm at T_s≥300 °C, while Sb incorporation probabilities σ_Sb varied from unity at T_s≲550 °C to ≃0.1 at 750 °C. These t_e and σ_Sb values are approximately one and one to three orders of magnitude, respectively, higher than reported results achieved with molecular-beam epitaxy. Temperature-dependent transport measurements carried out on 1-μm-thick Sb-doped IBSD layers grown at T_s≥350 °C showed that Sb was incorporated into substitutional sites with complete electrical activity and that electron mobilities in films grown at T_s≥400 °C were equal to the best reported results for bulk Si.