Multiple beam ellipsometer
US6798512B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2002 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Jun 30, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J4/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ellipsometric apparatus provides two impinging focused probe beams directed to reflect off the sample along two mutually distinct and preferably substantially perpendicular directions. A rotating stage rotates sections of the wafer into the travel area defined by two linear axes of two perpendicularly oriented linear stages. As a result, an entire wafer is accessed for measurement with the linear stages having a travel range of only half the wafer diameter. The reduced linear travel results in a small travel envelope occupied by the wafer and consequently in a small footprint of the apparatus. The use of two perpendicularly directed probe beams permits measurement of periodic structures along a preferred direction while permitting the use of a reduced motion stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.