Modulated beam study of adsorption-induced-desorption reaction, H + D/Si(100) ' D2
Abstract
We have studied the kinetics mechanism of the adsorption-induced-desorption (AID) reaction, H + D/Si(100) → D_2. Using a modulated H beam, two different types of AID reactions are revealed: one is the fast AID and the other is the slow AID reaction, occurring only at the beam on- and even at the beam off-cycles, respectively. Both the fast and slow AID reactions show the different dependence on surface temperature T_s, suggesting that their kinetics mechanisms are different. The fast AID reaction overwhelms the slow one in the desorption yield for all over the tested region 300K≤ Ts ≥ 650K. It proceeds along a first-order kinetics with respect to the incident H flux. Based on the experimental results, both two AID reactions are suggested to occur only on the 3× 1 di-hydride phase accumulated under surface exposure to H atoms. Possible mechanisms for the two AID reactions are discussed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MAR.K1022F