B Atomic layer doping (B-ALD) of Ge is investigated at temperatures between 100 degrees C and 400 degrees C using a single wafer reduced pressure CVD system. Hydrogen-terminated and hydrogen-free Ge (100) surfaces are exposed to B(2)H(6) at different H(2) partial pressures. B atoms are adsorbed on hydrogen-free Ge surface by B(2)H(6) exposure even at 100 degrees C. Very steep B profiles (< 1 nm/dec), which is the resolution limit of SIMS, have been achieved. On the hydrogen-free Ge surface at 200-400 degrees C, B adsorption is increasing with increasing B(2)H(6) exposure time and no saturation behavior is observed. On the other hand, in the case of 100 degrees C, B adsorption is increasing with increasing B(2)H(6) exposure time and tends to saturate, indicating that B(2)H(6) is adsorbed at Ge surface site mainly. The level of the saturation is increasing with increasing B(2)H(6) partial pressure. By decreasing the H(2) partial pressure, the level of the saturation is increasing and the saturation becomes less pronounced. For the B(2)H(6) exposure without H(2), the saturation is not observed. This result indicates that H(2) has to be taken into consideration for the adsorption mechanism of B. These results demonstrate the possibility of dopant dose and location control at 100 degrees C. (C) 2009 Elsevier B.V. All rights reserved.