Quantitative characterization and modeling of sub-bandgap absorption features in thin oxide films from spectroscopic ellipsometry data

AIMS Materials Science

Natalia Malkova¹  Dmitriy V. Likhachev²  Leonid Poslavsky³ 

[1] Co. KG, Wilschdorfer Landstr. 101, D-01109 Dresden, Germany;;GLOBALFOUNDRIES Dresden Module One LLC &KLA-Tencor Corp., One Technology Drive, Milpitas, CA 95035, U.S.A;

关键词: thin oxide films;    optical characterization;    spectroscopic ellipsometry;    optical constants;    dielectric function;    parameterization;    optical modeling;    optical metrology;   

DOI  :  10.3934/matersci.2015.4.356

来源: DOAJ

【 摘 要 】

Analytic representations of the complex dielectric function, which describe various types of materials, are needed for the analysis of optical measurements, in particularly, ellipsometric data. Here, we examine an improved multi-oscillator Tauc-Lorentz (TL) model with a constraint on the band-gap parameter E_g, which forces it to be common for all TL oscillators, and possibility to represent reasonably weak absorption features below the bandgap by inclusion of additional unbounded Lorentz and/or Gaussian oscillators with transition energies located below E_g. We conclude that the proposed model is the most appropriate for the characterization of various materials with sub-band absorption features and provides meaningful value for the energy bandgap. A few examples to illustrate the use of modified model have been provided.

【 授权许可】

Unknown