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Second harmonic generation spectroscopy on Si surfaces and interfaces
Author(s) -
Pedersen Kjeld
Publication year - 2010
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200983957
Subject(s) - spectroscopy , dangling bond , second harmonic generation , materials science , surface second harmonic generation , silicon , surface states , excited state , oxide , silicon on insulator , thin film , condensed matter physics , surface (topology) , atomic physics , nanotechnology , optoelectronics , physics , optics , laser , quantum mechanics , geometry , mathematics , metallurgy
Optical second harmonic generation (SHG) spectroscopy studies of Si(111) surfaces and interfaces are reviewed for two types of systems: (1) clean 7 × 7 and $\sqrt 3 \times \sqrt 3$ ‐Ag reconstructed surfaces prepared under ultra‐high vacuum conditions where surface states are excited and (2) interfaces in silicon‐on‐insulator (SOI) structures and thin metal films on Si surfaces where several interfaces contribute to the SHG. In all the systems resonances are seen at interband transitions near the bulk critical points E 1 and E 2 . On the clean surfaces a number of resonances appear below the onset of bulk‐like interband transitions that can be referred to excitations of dangling bond surface states. Adsorption of oxygen leads to formation of a new surface resonance. Such resonances appearing in the region between the bulk critical points E 1 and E 2 are also shown to be important for Si/oxide interfaces in SOI structures. Finally, examples of spectroscopy on layers buried below thin Ag and Au films are given.