A method that uses second-harmonic generation is applied to the study of the oxidized Si(111) surface by in situ control of thermal and synthetic oxide etching with monolayer atomic resolution. It is shown that the thin oxide layer that is adjacent to the Si surface (with a 5–10-Å thickness) exerts a strong influence on the reflected second-harmonic intensity. The contribution of the remaining bulk oxide is insignificant. Various contributions to the nonlinear polarization in the SiO2–Si interface, such as the static electric field, the inhomogeneous deformation, and the effect of a crystalline oxide layer, are considered.
© 1991 Optical Society of America
Original Manuscript: April 24, 1990
Revised Manuscript: January 28, 1991
Published: August 1, 1991
L. L. Kulyuk, O. A. Aktsipetrov, D. A. Shutov, and E. E. Strumban, "Second-harmonic generation by an SiO2–Si interface: influence of the oxide layer," J. Opt. Soc. Am. B 8, 1766-1769 (1991)