Pulsed spectroscopy with spatially variable polarization modulation element
US7064828B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2001 |
| Grant date | Jun 20, 2006 |
| Priority date | — |
| Expiry date | Mar 3, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/213
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A metrology device, such as an ellipsometer, includes a light source that produces a pulsed electromagnetic beam, such as a flash bulb or pulsed laser, and a spatially dependent polarizing element that introduces a spatially dependent retardation in the light beam. The use of a pulsed light source is advantageous over a continuous light source, as a pulsed light source generates less heat, is stronger, lasts longer, and does not need the use of a mechanical shutter. The use of a spatially dependent polarizing element advantageously eliminates the use of temporally dependent moving polarization modulation elements, thereby allowing the use of a pulsed light source. Downstream of the spatially dependent polarizing element are the analyzer and a multi-element detector that may be synchronized with the pulsed electromagnetic beam to detect after one or several pulses of light have been emitted from the pulsed light source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.