Multi-Layer Film Analysis by Ellipsometry

Download PDF May 30, 2017

Introduction

M-500 Spectroscopic Ellipsometer

Ellipsometry is a method for determining the refractive index and extinction coefficients of a sample by measuring the change in polarization state of surface reflected light. Film thickness and optical constants of an adsorption layer or oxide film on a substrate surface can be determined with exceptional sensitivity. Conventional interference spectroscopy utilizes light passed through separate optical paths, while ellipsometry is a form of interferometry that uses two vibrational components with the same optical path, providing measurements with excellent accuracy and sensitivity.

Diagram of PEM Principle

Result

JASCO developed a special program for calculating the film thickness and optical constants for each layer of a multi-layer film based on the ellipsometric dispersion parameters (∆, ψ)λ for the material. A multi-layer film model is developed for the sample, the film thickness and optical constants are optimized to minimize the error for the measured values.

About the Author

Leah Pandiscia received her PhD from Drexel University where she studied Biophysical Chemistry. She is a Spectroscopy Applications Scientist at JASCO.