Structural characterization of different insulating films by spectroscopic ellipsometry and grazing x‐ray reflectance

1996 ◽  
Vol 446 ◽  
Author(s):  
P. Boher ◽  
J.L. Stehle ◽  
L. Hennet

AbstractSpectroscopic Ellipsometry (SE) and Grazing X‐ray Reflectance (GXR) techniques are applied for different insulating films to determine precisely the thickness and optical indices of the layers. Antireflective coatings for microlithography in the DUV range are first analyzed. In the infrared range the layers are transparent and one can take into account the optical index of the layers by a simple dispersion law. Thicknesses obtained by this method are checked by the GXR technique. Extraction of the optical indices from UV to IR is made very accurately taking into account different SE measurements at various incident angles simultaneously. Amorphous carbon thin films are also analyzed in the same way. The main difference is that the layer is absorbant in the entire wavelength range. In this case, a first characterization by the GXR technique is essential to extract the thickness of the layer. Then the optical indices of the layer can be extracted very accurately by SE.

1998 ◽  
Vol 83 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Guolin Yu ◽  
Kalaga Murali Krishna ◽  
Chunlin Shao ◽  
Masayoshi Umeno ◽  
Tetsuo Soga ◽  
...  

1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.


1989 ◽  
pp. 261-268 ◽  
Author(s):  
George Andermann ◽  
Francis Fujiwara ◽  
T. C. Huang ◽  
J. K. Howard ◽  
N. Staud

2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.


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