Browse Prior Art Database

Ellipsometer

IP.com Disclosure Number: IPCOM000083079D
Original Publication Date: 1975-Mar-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Edwards, EP: AUTHOR [+3]

Abstract

An ellipsometer system is described for reducing or eliminating the effects of photodetector sensitivity to polarization of the light, which is used to measure the angular position of minima and maxima of the light reflected from a sample under examination.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Ellipsometer

An ellipsometer system is described for reducing or eliminating the effects of photodetector sensitivity to polarization of the light, which is used to measure the angular position of minima and maxima of the light reflected from a sample under examination.

In the figure, light from a laser 10 or other source is directed through a polarizer 12 and is reflected from a specimen 14. A quarter-wave plate 16 is affixed to the exit of a rotating analyzer 18 in a manner, such that any light emanating from analyzer 18 is converted from linear to circular polarization. This reduces or eliminates any amplitude effects introduced to the signal, by any sensitivity to the angle of polarization of light received by the photodetector 20. The system may also include an optional post randomizer/diffuser 22 and fiber optic bundle 24.

The system has the advantage that the amount of light received by photodetector 20 is not significantly diminished. Because more light reaches the photodetector, this system is useful when a variable-frequency light source is used which has lower light output than a laser, or when for other reasons it is desirable to have a greater percentage of the light reflected from the specimen reach the photodetector 20.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]