Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Infrared Spectroscopic Ellipsometry of Self-Assembled Monolayers

Published

Author(s)

Curtis W. Meuse

Abstract

Ellipsometry measures the relative intensity of and the phase difference between the parallel (p) and perpendicular (s) components of an electric field vector interacting with a sample. In this paper, a technique using polarized Fourier transform infrared spectroscopy (FTIR) for measuring this information, as the complex optical density function, is presented. The advantage of the complex optical density function is that it relates the changes in the polarization state to an uncoated reference sample instead of to the plane of incidence. This simplifies the calibration procedure and clarifies what is being measured since the specific properties of the metal surface and experimental setup are removed from the results. In this configuration, the precise positioning of the sample compared to the reference surface and the reproducibility of the analyzer movement are the most important contributions to the error in the complex optical density function. In this paper, we demonstrate that these errors are small compared to the changes from the presence of a self-assembled monolayer. We then compare the measured complex optical density functions to ones simulated using electromagnetic wave theory models for measured complex optical density functions to ones simulated using electromagnetic wave theory models for describing the optical properties of multilayer samples. By matching our measurments and simulations, we are able to determine the molecular orientations of the alkane bhains and the thicknesses of the monolayers.
Citation
Langmuir
Volume
16
Issue
24

Keywords

alkane thiol, complex optical density, infrared ellipsometry, infrared spectroscopy, self-assembled monolayer, spectroscopic ellipsometry, thickness

Citation

Meuse, C. (2000), Infrared Spectroscopic Ellipsometry of Self-Assembled Monolayers, Langmuir (Accessed May 28, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created November 28, 2000, Updated February 19, 2017