Diffractive optical elements and grid polarizers in focusing spectroscopic ellipsometers
AssigneeTherma-Wave, Inc.
InventorsLawrence D. Rotter, David Wang
Life of this patent
Estimating the term…
Abstract
One aspect of the present invention relates to a system and method for mitigating errors in SE data in order to determine changes in a polarization state of a source beam after interaction with a specimen. The system includes a light source for directing a source beam to a focusing optical element, a polarization system comprising a diffractive optical element or a wire grid polarizer, located between the focusing optical element and the specimen such that the source beam is polarized after being reflected from the focusing optical element. The polarized source beam is transmitted to the specimen. Changes in polarization state of the beam created by interaction with the sample are monitored to characterize the sample.
Claims12
An optical measurement system comprising a spectroscopic ellipsometer for evaluating characteristics of a specimen, the spectroscopic ellipsometer comprising:
- a broad band light source for generating a polychromatic probe beam;
- an optical element for focusing the probe beam;
- a polarization system comprising at least one diffractive optical element, wherein the polarization system is located between the focusing element and the specimen such that the probe beam is polarized after being focused;
- and
- a light detection system for determining the change in polarization state of the probe beam after reflection from the specimen.
An optical measurement system comprising a spectroscopic ellipsometer for evaluating characteristics of a specimen, the spectroscopic ellipsometer comprising:
- a broad band light source for generating a polychromatic probe beam;
- an optical element for focusing the probe beam;
- a polarization system comprising at least one wire grid polarizer wherein the polarization system is located between the focusing element and the specimen such that the probe beam is polarized after being focused;
- and
- a light detection system for determining the change in polarization state of the probe beam after reflection from the specimen.
An optical measurement system comprising a spectroscopic ellipsometer for evaluating characteristics of a specimen, the spectroscopic ellipsometer comprising:
- a broad band light source for generating a polychromatic probe beam;
- an optical element for focusing the probe beam;
- a polarization system comprising at least one diffractive optical element, wherein the polarization system is located between the focusing element and the specimen such that the probe beam is polarized into two orthogonal polarization states after being focused;
- and
- a light detection system positioned to receive a desired polarization state from said two orthogonal polarization states and determine the change in the desired polarization state after reflection from the specimen.
An optical measurement system comprising a spectroscopic ellipsometer for evaluating characteristics of a specimen, the spectroscopic ellipsometer comprising:
- a broad band light source for generating a polychromatic probe beam;
- an optical element for focusing the probe beam;
- a polarization system comprising at least one wire grid polarizer, wherein the polarization system is located between the focusing element and the specimen such that a single polarization of the probe beam is transmitted after being focused;
- and
- a light detection system for determining the change in the single polarization state of the probe beam after reflection from the specimen.
Dependencies are inferred from the claim text.