Identification of strained silicon layers at Si-<span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">SiO</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> interfaces and clean Si surfaces by nonlinear optical spectroscopy

W. Daum; H.-J. Krause; U. Reichel; H. Ibach

doi:10.1103/PhysRevLett.71.1234

Identification of strained silicon layers at Si- ${SiO}_{2}$ interfaces and clean Si surfaces by nonlinear optical spectroscopy

W. Daum, H.-J. Krause, U. Reichel, and H. Ibach

Phys. Rev. Lett. 71, 1234 – Published 23 August 1993

Abstract

Optical second-harmonic and sum-frequency spectra of clean and oxidized Si(100) and Si(111) samples reveal a strong resonance band at 3.3 eV photon energy. It is concluded that the resonance arises from direct transitions between valence and conduction band states in a few monolayers of strained silicon at the Si- ${SiO}_{2}$ interface and at the selvedge of clean reconstructed silicon surfaces.