Methods and systems for characterization of an x-ray beam with high spatial resolution

US11073487B2 · kind B2 · utility

Assignee

• KLA-TENCOR CORPORATION · US

Inventors

• Alexander N. Bykanov · San Diego, US
• Nikolay Artemiev · Berkeley, US
• Joseph A. Di Regolo · Livermore, US
• Antonio Arion Gellineau · Santa Clara, US
• Alexander Kuznetsov · Austin, US
• Andrei Veldman · Sunnyvale, US
• John J. Hench · Los Gatos, US

Key dates

• Filing date: May 9, 2018
• Grant date: Jul 27, 2021
• Expiry date: Aug 6, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/68764
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Methods and systems for positioning a specimen and characterizing an x-ray beam incident onto the specimen in a Transmission, Small-Angle X-ray Scatterometry (T-SAXS) metrology system are described herein. A specimen positioning system locates a wafer vertically and actively positions the wafer in six degrees of freedom with respect to the x-ray illumination beam without attenuating the transmitted radiation. In some embodiments, a cylindrically shaped occlusion element is scanned across the illumination beam while the detected intensity of the transmitted flux is measured to precisely locate the beam center. In some other embodiments, a periodic calibration target is employed to precisely locate the beam center. The periodic calibration target includes one or more spatially defined zones having different periodic structures that diffract X-ray illumination light into distinct, measurable diffraction patterns.