Method and apparatus for ellipsometric metrology for a sample contained in a chamber or the like

US6687002B2 · kind B2 · utility

Assignee

• Societe de Production et de Recherches Appliquees Sopra · FR

Inventors

• Jean-Louis Stehle · Colombes, FR
• Pierre Boher · Yerres, FR

Key dates

• Filing date: May 25, 2001
• Grant date: Feb 3, 2004
• Expiry date: Sep 29, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L22/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An ellipsometric metrology apparatus for a sample contained in a chamber. A light source outside the chamber produces the illuminating beam. A polarizing device outside the chamber polarizes the illuminating beam. A window of selected dimensions and features is disposed in a plane substantially parallel to the sample surface and at least partly closes the chamber. A first directing device directs the polarized illuminating beam on to an area of the sample along a first optical path extending from the polarizing device to the area of the sample through the window. The first optical path forms a predetermined oblique angle of incidence relative to the sample surface. A polarization analyzing device is outside the chamber, a second directing device directs the reflected beam resulting from the illumination of the sample by the illuminating beam on to the analyzing device along a second optical path extending from the sample towards the analyzing device through the window. The reflected beam is symmetrical to the illuminating beam relative to a normal to the sample surface. A detecting device detects the output beam transmitted by the analyzing device in order to supply an output signa…