Share Email Print
cover

Proceedings Paper

Ellipsometric measurement of the optical properties and electrical conductivity of indium tin oxide thin films
Author(s): John A. Woollam; William A. McGahan; Blaine D. Johs
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Films of indium tin oxide (ITO) are ubiquitous in display applications as they combine optical transparency and good electrical conductivity. Thin ITO films are often difficult to characterize optically as they are often inhomogeneous and have complicated optical absorption spectra. In this work, we have used variable angle of incidence spectroscopic ellipsometry (VASE) to gauge the thickness, grading, and surface roughness of ITO films ranging from a few tens of nm to hundreds of nm thick on glass substrates. A two Lorentz oscillator model is used, with one oscillator representing the interband absorption in the UV end of the spectrum, and the second oscillator modeling the Drude-like free carrier absorption in the infrared. The Drude parameters obtained from the analysis of the films can be used to estimate the electrical (D.C.) conductivity of the film from the simple Drude model for free carriers. We present results for several films from 7 to 40 nm thick, and compare the nominal electrical resistivity of these films to the resistivity derived from the VASE measurements.

Paper Details

Date Published: 4 November 1994
PDF: 7 pages
Proc. SPIE 2253, Optical Interference Coatings, (4 November 1994); doi: 10.1117/12.192175
Show Author Affiliations
John A. Woollam, J.A. Woollam Co. (United States)
William A. McGahan, J.A. Woollam Co. (United States)
Blaine D. Johs, J.A. Woollam Co. (United States)


Published in SPIE Proceedings Vol. 2253:
Optical Interference Coatings
Florin Abeles, Editor(s)

© SPIE. Terms of Use
Back to Top