Patent · US Active

Single grab overlay measurement of tall targets

US12066322B2 · kind B2 · utility

1Cited by

2References

40Claims

0Family size

Assignee

KLA Corporation · US

Inventors

Amnon Manassen · Haifa, IL
Andrew V. Hill · Chino Hills, US
Yonatan Vaknin · Yoqneam Illit, IL
Avner Safrani · Beer Sheva, IL

Key dates

Filing date	Nov 14, 2022
Grant date	Aug 20, 2024
Priority date	—
Expiry date	Feb 15, 2043

Classification

Technology area (CPC G)Physics
CPC primaryG01J2009/0242
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An overlay metrology system may include an objective lens, illumination optics to illuminate an overlay target including a first grating with a first pitch on a first sample layer and a second grating with a second pitch on a second sample layer, where the first and second sample layers are separated by a layer separation distance greater than a depth of field of the objective lens. The system may further include collection optics with a radially-varying defocus distribution to compensate for the layer separation distance such that the first and second gratings are simultaneously in focus on the detector.

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