CRYSTAL-GROWTH AND ELECTRONIC-PROPERTIES OF ULTRAHIGH-VACUUM ION-BEAMSPUTTER-DEPOSITED SB-DOPED SI(001)2X1

High-quality homoepitaxial Sb-doped Si(001)2x1 films have been grown o n p-type Si(001) substrates by ultrahigh vacuum ion-beam sputter depos ition (IBSD) at temperatures T(s) between 450 and 750-degrees-C. The l oad-locked multichamber system is equipped with in situ reflection hig h-energy electron diffraction. Sputter deposition was carried out usin g a 1 keV Kr+ ion beam generated by a modified Kaufman-type ion source with post-extraction electrostatic ion optics. All films were 1 mum t hick and deposited at a rate of 0.35 mum h-1. Results of plan-view, cr oss-sectional, and convergent-beam transmission electron microscopy an alyses showed that as-deposited films are highly perfect with no visib le defects. Sb incorporation probabilities sigma(Sb) ranged from -0.1 at T(s) = 750-degrees-C to congruent-to 1 for T(s) less-than-or-equal- to 550-degrees-C with no indication by secondary-ion mass spectrometry (SIMS) of Sb surface segregation. These sigma(Sb) values are one to t hree orders of magnitude larger than for coevaporative Sb doping durin g molecular beam epitaxy where extensive Sb surface segregation is obs erved. A comparison of calibrated SIMS and Hall-effect measurements es tablished that the incorporated Sb exhibited complete electrical activ ity. SIMS analyses also showed no detectable Kr (detection limit congr uent-to 5 x 10(17) cm-3). Temperature-dependent (15-300 K) electron mo bilities were equal to the best reported bulk Si values.