AVS 52nd International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP24
Comparative Study of the Initial Oxidation Kinetics on Si(001) and Ti(0001) Surfaces by Real-Time Ultraviolet Photoelectron Spectroscopy

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: Y. Takakuwa, IMRAM, Tohoku University, Japan
Authors: Y. Takakuwa, IMRAM, Tohoku University, Japan
S. Ogawa, IMRAM, Tohoku University, Japan
M. Ohira, IMRAM, Tohoku University, Japan
Y. Mizuno, Stanford University
Correspondent: Click to Email
Oxidation on Si and Ti surfaces leads to growth of SiO@sub 2@ and TiO@sub 2@ layer, respectively. In order to clarify the behavior of adsorbed oxygen during growth of oxide, the initial oxidation kinetics on Si(001)2x1 and Ti(0001)1x1 surfaces was comparatively investigated by real-time ultraviolet photoelectron spectroscopy to measure the oxygen uptake and work function @phi@ simultaneously. Onn the Si surface at 357°C, the @phi@ increases gradually with increase of O@sub 2@ dosage after showing a dip due to negative changes, while the dip disappears with elevating temperature. The negative change of @phi@ means diffusion of adsorbed oxygen into the subsurface. On the other hand, a dip in @phi@ appears at temperatures above 300°C on the Ti surface. This suggests that adsorbed oxygen on the Ti surface can easily diffuse into the subsurface when elevating temperature, although such diffusion of adsorbed oxygen tends to occur on the Si surface when lowering temperature. The difference of adsorbed oxygen behavior between Si and Ti surfaces is discussed in terms of the O@sub 2@ dissociative adsorption kinetics and crystallographic nature of oxide, amorphous SiO@sub 2@ and crystalline TiO@sub 2@.