Analysis of variable scale surface roughness on Si(111): a comparative Brewster angle, ellipsometry and atomic force microscopy investigation

Abstract

To cite this article: M. Lublow & H. J. Lewerenz (2005) Analysis of variable scale surface roughness on Si(111): a comparative Brewster angle, ellipsometry and atomic force microscopy investigation, Transactions of the IMF, 83:5, 238-247 To link to this article: http://dx.Brewster angle analysis (BAA) and single wavelength ellipsometry (SWE) were used to investigate the optical response of Si(111), exposed to subsequent 40% NH 4 F etching steps, each persisting for 20 s. During native oxide layer etchback and anisotropic etching of the silicon substrate, ultrasmall variations were accurately observed. Contact mode atomic force microscopy (CM AFM) was performed to describe the scale dependence of roughness analysis and to correlate optical and micro-topographical information. It can be shown that BAA and SWE are of comparable sensitivity with respect to variations in film thickness and surface roughness. Quantitative analysis, however, leads to new insights into the information obtainable from the optical methods. BAA data, i.e. the Brewster angle and the reflectance at the Brewster angle, change each in a unique direction, if a clean and smooth surface slightly deteriorates. Ellipsometry, however, shows more complicated variations of the data depending on the concurrent presence of small and long correlation length surface roughness. A combination of both methods allows separating and quantification of these roughness contributions.

Tailoring of Interfaces for the Photoelectrochemical Conversion of Solar Energy

“…The absorption due to excitation of an electronic defect within the bandgap was expected to change the Brewster angle and the refl ectivity at that angle [136] , which was indeed observed for GaAs and CuInS 2 for instance [137] , thus providing a contactless method for identifi cation of electronic defects at room temperature. In a second application, it was shown that the high surface sensitivity of the method can be used for optical analyses [138,139] . Because the change of the Brewster angle and the refl ectivity at this angle are measured simultaneously, yielding two experimental parameters in one measurement, the method has a certain similarity to ellipsometry where the ellipsometer angles ∆ and Ψ are recorded [140] .…”

Brewster-angle analysis of native and photoelectrochemically grown silicon oxide nanotopographies

“…The refractive index n ox ¼ ffiffiffiffiffi ffi e ox p of the anodic oxide and its thickness were determined from a fitting procedure of the obtained parabola-shaped curves. The non-zero light beam divergence was corrected by a mathematical procedure [15,16].…”

“…For nanostructures characterization, Brewster-angle analysis (BAA) [11][12][13][14] has recently been applied as a powerful technique for detection of interface roughness and oxide thickness changes in the range 61 Å for the silicon oxide/silicon system [15,16]. In this work, in-situ real-time Brewster-angle reflectometry (BAR) is used for the first time in combination with ex-situ BAA and atomic force microscopy to analyse the interface and oxide structure during current oscillations.…”

Combined AFM and Brewster-angle analysis of gradually etched ultrathin SiO2 – Comparison with SRPES results

“…The method was also applied in pulsed chemical beam epitaxy (PCBE) to follow epitaxial growth of Ga x I 1Àx P on Si(0 0 1) with below monolayer resolution [5][6][7]. Recently, we performed combined ellipsometry, AFM and BAA analysis of nano-roughness changes induced by etching the native oxide layer on silicon [8]. In the present work, we analyze the silicon/silicon oxide system quantitatively using BAA, AFM and SRPES.…”