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Optical Characterization and Modeling of Amorphous Hydrogenated Carbon Films*

Published online by Cambridge University Press:  22 February 2011

William A. McGahan  and
John A. Woollam
William A. McGahan
Affiliation:
Center for Microelectronic and Optical Materials Research, andDepartment of Electrical Engineering University of Nebraska-Lincoln Lincoln, NE 68588-05 11 J. A. Woollam Co., Inc.650 J. Street, Suite 39 Lincoln, NE 68508
John A. Woollam
Affiliation:
Center for Microelectronic and Optical Materials Research, andDepartment of Electrical Engineering University of Nebraska-Lincoln Lincoln, NE 68588-05 11 J. A. Woollam Co., Inc.650 J. Street, Suite 39 Lincoln, NE 68508
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Abstract

Amorphous hydrogenated carbon (a-C:H) thin films are of great importance in a number of industrial applications due to their hardness, chemical stability, and optical transparency. In many applications, the thickness of the a-C:H film and/or its optical properties are critical for the performance of the complete structure, and, as a result, a means of measuring these quantities is important. In this work we review the use of spectroscopic ellipsometry and transmission measurements for the estimation of the thickness and optical constants of thin a-C:H films. Spectra are shown for films exhibiting Tauc effective bandgaps ranging from 0 - 2.3 eV. The films were prepared by magnetron sputtering and plasma CVD on both silicon and glass substrates. The general energy dependence of the a-C:H optical constants is discussed in terms of the absorption processes which occur in the film.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 349: Symposium T – Novel Forms of Carbon II , 1994 , 453
Copyright
Copyright © Materials Research Society 1994

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Footnotes

*

Research supported by Air Force Grant F08630-91-C-0047 and NASA Lewis Grant NAG-3-95

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