Hydrogen (H(g)) abstraction of D adatoms (D_(ad)) and collision-induced desorption (CID), to form D_2, have been comparatively studied on the single crystalline C, Ge and Si(100) surfaces using a thermal (approx 0.05 eV) H(g) beam. Strong HD and D_2 desorptions were observed during exposure on D_(ad)/Si(100) and D_(ad)/Ge(100) surfaces. For both surfaces, it was found that the CID reaction follows a fourth-order kinetics in the D_(ad) coverage #theta#_D, while as was expected, the abstraction reaction proceeds at a first-order kinetics in D. However, for the fairly smooth D_(ad)/C(100) surface as relaxed in the plasma CVD process neither abstraction nor CID were admitted, indicating that the D-covered C(100) surface is quite inactive towards the thermal H(g) beam particularly at the terrace site. However, it was observed that H(g) abstraction of D_(ad) takes place as the D_(ad)/surface was subjected to the D(g) beam in a high vacuum reaction chamber, suggesting that D atoms can stick to the deuterated surface. Sticking efficiency of D atoms was found to become high on the less smooth H_(ad)/C(100) surface, indicating that D sticking becomes efficient as the surface becomes rough. It was argued that such additional D sticking to the D or H-terminated C(100) surfaces takes place at the step edges or the defect sites rather than at the terraces.
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