AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP2
What Governs the Si(100) Low Temperature Phase ? - Study by STM and LEED

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Surface Science Poster Session
Presenter: S. Yoshida, University of Tsukuba, CREST, Japan
Authors: S. Yoshida, University of Tsukuba, CREST, Japan
O. Takeuchi, University of Tsukuba, CREST, Japan
K. Hata, University of Tsukuba, CREST, Japan
H. Shigekawa, University of Tsukuba, CREST, Japan
Correspondent: Click to Email
Through the recent intensive study on the low temperature phase of Si(100) by Scanning Tunneling Microscopy (STM) and Non-Contact Atomic Force Microscopy, symmetric dimmer, c(4x2)/p(2x2), and c(4x2) phases have been confirmed to exist below 30K, giving rise to the controversy on the ground state of Si(100). In addition to these structures, we recently succeeded in observing a single p(2x2) phase by STM at 10K for the first time, and have studied the conditions for the appearance of all these phases. For example, although c(4x2) phase easily appears in the case of p-type Si(100), particular sample conditions are necessary for the observation of the p(2x2) single phase; (1) n-type, (2) high dope, and (3) very low defect density. Furthermore, for the n-type Si(100) surface, we have succeeded in the direct observation of the phase transition between p(2x2) phase (lower temperature side) and c(4x2) phase (higher temperature side) by STM and LEED measurements. These obtained results suggest the great importance of the dopant and defect influences on the Si(100) surface phase transitions. Tip induced effect will also be discussed.