Patent · US Active

Overlay measurements of overlapping target structures based on symmetry of scanning electron beam signals

US10473460B2 · kind B2 · utility

15Cited by

8References

35Claims

0Family size

Assignee

KLA-TENCOR CORPORATION · US

Inventors

Nadav Gutman · Zichron Ya'akov, IL
Eran Amit · Haifa, IL
Stefan Eyring · Weilburg, DE
Hari Pathangi · Chennai, IN
Frank Laske · Weilmünster, DE
Ulrich Pohlmann · Jena, DE
Thomas Heidrich · Dresden, DE

Key dates

Filing date	May 14, 2018
Grant date	Nov 12, 2019
Priority date	—
Expiry date	May 14, 2038

Classification

Technology area (CPC H)Electricity
CPC primaryH01J2237/31798
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

An overlay metrology system includes a particle-beam metrology tool to scan a particle beam across an overlay target on a sample including a first-layer target element and a second-layer target element. The overlay metrology system may further include a controller to receive a scan signal from the particle-beam metrology tool, determine symmetry measurements for the scan signal with respect to symmetry metrics, and generate an overlay measurement between the first layer and the second layer based on the symmetry measurements in which an asymmetry of the scan signal is indicative of a misalignment of the second-layer target element with respect to the first-layer target element and a value of the overlay measurement is based on the symmetry measurements.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.