IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Thursday Sessions
       Session EL-ThA

Paper EL-ThA5
In-situ Monitoring of Ag Film Growth on Si(111)7x7 Surface by Optical Second Harmonic Generation

Thursday, November 1, 2001, 3:20 pm, Room 124

Session: In-Situ Semiconductor Characterization
Presenter: H. Hirayama, Tokyo Institute of Technology, Japan
Authors: H. Hirayama, Tokyo Institute of Technology, Japan
T. Kawata, Tokyo Institute of Technology, Japan
K. Takayanagi, Tokyo Institute of Technology, Japan
Correspondent: Click to Email
A growth of Ag films on the Si(111)7x7 surface was monitored by optical second harmonic generation (SHG). Ag-coverage dependent intensity oscillation was observed in p-polarized SHG signals with 1.20,1.30 and 1.40 eV pump photon energy. As has been reported recently by Pedersen et al, the SHG intensity oscillated with the Ag coverage. However, on the contrary to the previous report, the first peak in the oscillations was observed at 3ML for all the pump energy. The peak position was independent on the pump energy. Meanwhile, the subsequent peaks shifted toward lower coverage with the increase in the pump photon energy. A detailed comparison of the SHG intensity and AFM images of the Ag film grown on the Si(111) substrate showed that many three-dimensional Ag islands nucleated at the coverage for the first peak. The surface morphology changed to be two-dimensional smooth one at the coverage for the subsequent peaks. The AFM images and the SHG spectrum taken at the coverages of the peaks showed that the first peak in the SHG intensity oscillation corresponded to the local plasmon resonance with the 3D Ag island formation. The subsequent peaks were caused by the transitions with the quantized electronic states confined in the thin, flat Ag films. The characteristic transitions between the electronic states localized at the Ag/Si(111)7x7, 1x1 and @sr@3x@sr@3 interfaces were also detected as resonant peaks in the s-polarized SHG spectrum with the excitation photon energy ranged from 1.05 to 1.70eV.