Determination of interface layer strain of Si/SiO2 interfaces by reflectance difference spectroscopy

Abstract

Detailed studies of the often-observed resonance feature near 3.4 eV in the reflectance difference spectrum of Si/SiO2 interfaces and Si surfaces show that the resonance is due to the intrinsic local-field effect, and that its energy position coincides with the E1 energy of bulk Si. Using the energy position of the resonance of the pseudomorphically grown Si/CaF2 interfaces as a reference point, the strain-induced resonance energy shift of the Si interface layer at several Si/SiO2 interfaces are obtained and the strain in these layers is determined. The results show that the interface layers are highly strained with an equivalent hydrostatic pressure of 0.79 GPa, but still maintain a high degree of order.

Understanding the optical anisotropy of oxidized Si(001) surfaces

“…On the other hand, earlier measurements of the Si-SiO 2 interface optical properties have often been interpreted in terms of strain-induced shifts of the Si bulk CP energies. [27][28][29] We perform model calculations for four layers of bulk Si uniformly compressed by 2% along ͓110͔, a value that roughly accounts for the lattice deformation around an oxygen atom inserted into a Si͑001͒͑2 ϫ 2͒ interface unit cell. As seen from the inset of Fig.…”

Raman and RAS Measurements on Uniaxially Strained Thin Semiconductor Layers

“…Dependence of the RAS signal of (100)Si on applied strain along [010] of the D 5 valence band [1], as well as stress-induced intraband coupling of D 1 to D 2 H [9] have then to be taken in account. Recently published low-temperature RAS studies of the strain of (111) and (211)Si/SiO 2 interfaces [10] have assigned the 3.4 eV resonance to the combined contribution of the E H 0 and E 1 critical energies of bulk Si. The intensity Dr/r = (r 010 ± ± r 001 )/r of the 3.39 eV peak (and also the intensity Dr/r = (r 011 À r 0 " 11 )/r of the double peak at 3.34 and 3.49 eV), measured from peak max.…”

Optical and Electronic Anisotropy of a π-Conjugated Molecular Monolayer on the Silicon(001) Surface

“…9,10 Since bulk silicon is symmetric, measurement of the optical properties using polarized light can then be used to characterize the optical response of the near-surface region. 11,12 While this method has been applied previously to characterize the changes in optical properties of different surface reconstructions and the effects of atomic adsorbates, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] it has not been widely used to characterize the optical properties of organic molecules. [32][33][34][35][36] To use polarization spectroscopy on organic films, it is necessary to have organic layers that have a preferred orientation in the surface plane.…”