B‐doped Si(001)2×1 films were grown on Si(001) substrates by gas‐source molecular beam epitaxy using Si2H6and B2H6. B concentrationsCB(5×1016–5×1019cm−3) were found to increase linearly with increasing flux ratioJB2H6/JSi2H6(9.3×10−5–2.5×10−2) at constant film growth temperatureTs(600–950 °C) and to decrease exponentially with 1/Tsat constantJB2H6/JSi2H6ratio. The B2H6reactive sticking probability ranged from &bartil;6.4×10−4atTs=600 °C to 1.4×10−3at 950 °C. The difference in the overall activation energies for B and Si incorporation atTs=600–950 °C is &bartil;0.34 eV. A comparison of quantitative secondary‐ion mass spectrometry (SIMS) and temperature‐dependent Hall‐effect measurements showed that B was incorporated into substitutional electrically active sites over the entire B concentration range investigated. SIMS B depth profiles from modulation‐doped samples were abrupt with no indication of surface segregation to within the instrumental resolution limit and initial &dgr;‐doping experiments were carried out. Structural analysis byinsitureflection high‐energy electron diffraction combined with post‐deposition high‐resolution plan‐view and cross‐sectional transmission electron microscopy showed that all films were high‐quality single crystals with no evidence of dislocations or other extended defects. Temperature‐dependent (20–300 K) hole carrier mobilities were equal to the best reported bulk Si:B values and in good agreement with theoretical maximum values. ©1995 American Institute of Physics.