Interpretation of Uv Reflectance Measurements on Silicon-On-Sapphire By Spectral Reflectance and Spectroscopic Ellipsometry Studies

1985 ◽  
Vol 53 ◽  
Author(s):  
C. Pickering ◽  
A.M. Hodge ◽  
A.C. Daw ◽  
D.J. Robbins ◽  
P.J. Pearson ◽  
...  
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Spectral Reflectance ◽  
Wavelength Dependence ◽  
Surface Scattering ◽  
Effective Medium Approximation ◽  
Relative Importance ◽  
Surface Layers ◽  
Scattering Effects ◽  
Uv Reflectance ◽  
Reflectance Measurements

ABSTRACTSpectral reflectance and spectroscopic ellipsometry measurements have been made on SOS wafers with haze ratings 1-5. The wavelength dependence of reflectance is dominated by surface scattering, but degraded crystallinity effects are also observed, and are significant in some samples. Analysis of dielectric function spectra using an effective medium approximation has indicated the presence of α-Si and voids in surface layers up to 300Å thick in medium haze wafers, with concentrations decreasing away from the surface. The assessment parameter normally used for SOS, UVR No., has been shown to includeboth crystallinity and scattering effects, and their relative importance cannot be determined without more detailed measurements.

Calculation of Spectral Optical Constants Using Combined Ellipsometric and Reflectance Methods for Smooth and Rough Bulk Samples

2021 ◽  
pp. 000370282110478
Author(s):  
Gilles Fortin
Keyword(s):  
Rough Surface ◽  
Optical Constants ◽  
Sample Surface ◽  
Infrared Region ◽  
Homogeneous Sample ◽  
Specular Reflectance ◽  
Scattering Effects ◽  
Spectral Ranges ◽  
Reflectance Measurements ◽  
Polarized Reflectance

Spectra of the optical constants n and k of a substance are often deduced from spectroscopic measurements, performed on a thick and homogeneous sample, and from a model used to simulate these measurements. Spectra obtained for n and k using the ellipsometric method generally produce polarized reflectance simulations in strong agreement with the experimental measurements, but they sometimes introduce significant discrepancies over limited spectral ranges, whereas spectra of n and k obtained with the single-angle reflectance method require a perfectly smooth sample surface to be viable. This paper presents an alternative method to calculate n and k. The method exploits both ellipsometric measurements and s-polarized specular reflectance measurements, and compensates for potential surface scattering effects with the introduction of a specularity factor. It is applicable to bulk samples having either a smooth or a rough surface. It provides spectral optical constants that are consistent with s-polarized reflectance measurements. Demonstrations are performed in the infrared region using a glass slide (smooth surface) and a pellet of compressed ammonium sulfate powder (rough surface).

Characterization of Quantum well Structures Using Microscope-Spectrophotometry

1993 ◽  
Vol 324 ◽  
Author(s):  
Rachel M Geatches ◽  
Karen J Reeson ◽  
Alan J Criddle ◽  
Roger P Webb
Keyword(s):  
Quantum Wells ◽  
Spectral Reflectance ◽  
Visible Spectrum ◽  
Ultra Violet ◽  
Measurement Range ◽  
Aluminium Content ◽  
Quantum Well Structures ◽  
Nondestructive Characterization ◽  
Reflectance Measurements

AbstractIn this paper the application of microscope-spectrophotometry to the nondestructive characterization of a variety of multi-layer GaAs/A1GaAs structures, is described. Spectral reflectance results are used to indirectly determine variations in aluminium content, and the interdependency of aluminium content with layer thicknesses. The penetration depth of light from the visible spectrum is assessed from the correlation between spectral reflectance measurements and fitted optical models. Finally, a series of single quantum wells are investigated, and it is concluded that a significant improvement in the characterization of these materials will be achieved with an extension of the spectral measurement range into the ultra violet.

Regional predictions of soil organic carbon content from spectral reflectance measurements

2009 ◽  
Vol 104 (3) ◽  
pp. 442-446 ◽  
Author(s):  
H. Aïchi ◽  
Y. Fouad ◽  
C. Walter ◽  
R.A. Viscarra Rossel ◽  
Zohra Lili Chabaane ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Spectral Reflectance ◽  
Organic Carbon Content ◽  
Soil Organic Carbon Content ◽  
Reflectance Measurements
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