Characterization of highly anisotropic three-dimensionally nanostructured surfaces

THIN SOLID FILMS

卷:571

Article; Proceedings Paper

Schmidt, Daniel^1,2 

[1] Univ Nebraska, Dept Elect Engn, Lincoln, NE 68588 USA

[2] Univ Nebraska, Ctr Nanohybrid Funct Mat, Lincoln, NE 68588 USA

关键词: Generalized ellipsometry;    Glancing angle deposition;    Atomic layer deposition;    Sculptured thin films;    Biaxial anisotropy;    Effective medium approximations;   

DOI  :  10.1016/j.tsf.2013.10.119

来源: Elsevier

【 摘 要 】

Generalized ellipsometry, a non-destructive optical characterization technique, is employed to determine geometrical structure parameters and anisotropic dielectric properties of highly spatially coherent three-dimensionally nanostructured thin films grown by glancing angle deposition. The (piecewise) homogeneous biaxial layer model approach is discussed, which can be universally applied to model the optical response of sculptured thin films with different geometries and from diverse materials, and structural parameters as well as effective optical properties of the nanostructured thin films are obtained. Alternative model approaches for slanted columnar thin films, anisotropic effective medium approximations based on the Bruggeman formalism, are presented, which deliver results comparable to the homogeneous biaxial layer approach and in addition provide film constituent volume fraction parameters as well as depolarization or shape factors. Advantages of these ellipsometry models are discussed on the example of metal slanted columnar thin films, which have been conformally coated with a thin passivating oxide layer by atomic layer deposition. Furthermore, the application of an effective medium approximation approach to in-situ growth monitoring of this anisotropic thin film functionalization process is presented. It was found that structural parameters determined with the presented optical model equivalents for slanted columnar thin films agree very well with scanning electron microscope image estimates. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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