B-doped Si(001) films, with concentrationsCBup to1.7×1022 cm−3,were grown by gas-source molecular-beam epitaxy fromSi2H6andB2H6atTs=500–800 °C.D2temperature-programed desorption (TPD) spectra were then used to determine B coverages&thgr;Bas a function ofCBandTs.In these measurements, as-deposited films were flash heated to desorb surface hydrogen, cooled, and exposed to atomic deuterium until saturation coverage. Strong B surface segregation was observed with surface-to-bulk B concentration ratios ranging up to 1200. TPD spectra exhibited&bgr;2and&bgr;1peaks associated with dideuteride and monodeuteride desorption as well as lower-temperature B-induced peaks&bgr;2*and&bgr;1*.Increasing&thgr;Bincreased the area under&bgr;2*and&bgr;1*at the expense of&bgr;2and&bgr;1and decreased the total D coverage&thgr;D.The TPD results were used to determine the B segregation enthalpy,−0.53 eV,and to explain and model the effects of high B coverages on Si(001) growth kinetics. Film deposition ratesRincrease by⩾50&percent;with increasingCB>˜1×1019 cm−3atTs⩽550 °C,due primarily to increased H desorption rates from B-backbonded Si adatoms, and decrease by corresponding amounts atTs⩾600 °Cdue to decreased adsorption site densities. AtTs⩾700 °C,high B coverages also induce {113} facetting. ©1997 American Institute of Physics.