AVS 49th International Symposium
    Electronic Materials and Devices Wednesday Sessions
       Session EL+SS+SC-WeA

Paper EL+SS+SC-WeA10
Direct Detection of D@sub 2@O and D@sub 2@ on D/Si(111) Surfaces under O Atom Exposures

Wednesday, November 6, 2002, 5:00 pm, Room C-107

Session: Semiconductor Film Growth and Oxidation
Presenter: F. Rahman, Kyushu Institute of Technology, Japan
Authors: F. Rahman, Kyushu Institute of Technology, Japan
F. Khanom, Kyushu Institute of Technology, Japan
A. Aoki, Kyushu Institute of Technology, Japan
S. Inanaga, Kyushu Institute of Technology, Japan
A. Namiki, Kyushu Institute of Technology, Japan
Correspondent: Click to Email
Initial oxidation stage of D/Si(111) surfaces by atomic oxygen (O) have been studied from the absorption point of view. O/D/Si(111) co-adsorbed surfaces were prepared by various O exposure on 1.25ML D/Si(111). TPD measurement shows nearly 50% reduction of D adatoms from the surface for 2 min O exposure indicating the D adatoms abstraction by incident O atoms. Measurement of desorbing species have been done with a QMS during O exposures on the 1ML D/Si(111) surface for various surface temperatures (T@sub S@). D@sub 2@O as well as D@sub 2@ molecules were observed. Rate curves of both species show an initial rate jump and then a gradual increase having a peak, which is followed by a nearly exponential decay with exposure time. Both D@sub 2@O and D@sub 2@ rates vs. T@sub S@ curves show similar line shape to the similar plot of D@sub 2@ rates vs. T@sub S@ curve obtained for the reaction system of H + D/Si(111) --> D@sub 2@. In a previous work, the later reaction was understood as due to the so-called @beta@@sub 2@ TPD desorption arising from a dideuteride phase. Therefore, we consider that the O induced D@sub 2@ formation proceeds along the same mechanism as for the @beta@@sub 2@-channel TPD. Regarding D@sub 2@O formation, it is significant and interesting since the reaction takes place as a result of picking up two D adatoms by single O atom upon collision. We will propose a possible mechanism to explain the O-induced D@sub 2@O formation on the D/Si(111) surfaces.