Reactions of atomic oxygen with the D-covered Si(1 0 0) surfaces

We have studied D abstraction by O on the D/Si(1 0 0) surfaces using a continuous as well as pulsed O-beams. Both D2 and D2O molecules are detected during O-exposure. The D2 desorption is found to take place more efficiently on the monodeuteride/dideuteride surface than on the monodeuteride surface. The pulsed beam experiments exhibit occurrence of both a slow and a fast D2 desorption. The D2 desorption is found to obey the second-order rate law in θ D 0 on the monodeuteride surfaces and 3.5th-order rate law on the monodeuteride/dideuteride surfaces. The D2O desorption is found to be governed also by the second-order rate law, however regardless of D coverage even on the monodeuteride/dideuteride surfaces. Possible mechanisms for the O-induced desorption from the D/Si(1 0 0) surfaces are discussed.