Ellipsometric study of thermally induced redistribution and crystallization of Ge in Ge:SiO2 mixture layers

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Article

Janicki, Vesna¹  Sancho-Parramon, Jordi¹  Zorc, Hrvoje¹  Salamon, Kresimir¹  Buljan, Maja¹  Radic, Nikola¹  Desnica, Uros¹ 

[1] Rudjer Boskovic Inst, Zagreb 10000, Croatia

关键词: Optical characterization;    Quantum confinement;    Material mixtures;    Spectroscopic ellipsometry;    Optical constants;    Crystallization of Ge;   

DOI  :  10.1016/j.tsf.2011.02.071

来源: Elsevier

【 摘 要 】

Mixture layers of Ge:SiO2 of 40:60 mol% respectively, have been prepared by co-sputtering. The thermally induced change of optical properties of the layers was studied by variable angle spectroscopic ellipsometry. The mixture was modelled as an unknown material with optical constants described by multiple oscillators. The optical parameters determined from ellipsometric measurements can be well correlated with structural changes in the mixture. The results indicate that Ge in the mixture deposited or annealed up to 600 degrees C is in an amorphous state and it redistributes with increase of temperature, changing refractive index through the layer. The crystallization starts between 600 and 650 degrees C, at first next to the substrate. Crystallites size grows with temperature. Results were compared with findings of grazing incidence wide angle X-ray scattering measurements and a good agreement was found. Ellipsometry has been shown to be an appropriate non-invasive technique for characterization of this kind of layers. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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