Title:
SELF-REFERENCING AND SELF-CALIBRATING INTERFERENCE PATTERN OVERLAY MEASUREMENT
Document Type and Number:
WIPO Patent Application WO/2019/139772
Kind Code:
A1
Abstract:
Two pairs of alignment targets (one aligned, one misaligned by a bias distance) are formed on different masks to produce a first pair of conjugated interference patterns. Other pairs of alignment targets are also formed on the masks to produce a second pair of conjugated interference patterns that are inverted the first. Misalignment of the dark and light regions of the first interference patterns and the second interference patterns in both pairs of conjugated interference patterns is determined when patterns formed using the masks are overlaid. A magnification factor (of the interference pattern misalignment to the target misalignment) is calculated as a ratio of the difference of misalignment of the relatively dark and relatively light regions in the pairs of interference patterns, over twice the bias distance. The interference pattern misalignment is divided by the magnification factor to produce a self -referenced and self-calibrated target misalignment amount, which is then output.
Inventors:
YANG DONGYUE (US)
DAI XINTUO (US)
PARK DONGSUK (US)
TANG MINGHAO (US)
BELLAH MD (US)
SRIPADARAO PAVAN KUMAR (US)
WONG CHEUK (US)
DAI XINTUO (US)
PARK DONGSUK (US)
TANG MINGHAO (US)
BELLAH MD (US)
SRIPADARAO PAVAN KUMAR (US)
WONG CHEUK (US)
Application Number:
PCT/US2018/067011
Publication Date:
July 18, 2019
Filing Date:
December 21, 2018
Export Citation:
Assignee:
GLOBALFOUNDRIES US INC (US)
International Classes:
G03F7/20; G03F9/00
Foreign References:
| US20060044568A1 | 2006-03-02 | |||
| EP1400855A2 | 2004-03-24 | |||
| US20100005442A1 | 2010-01-07 | |||
| US20130208279A1 | 2013-08-15 |
Other References:
None
Attorney, Agent or Firm:
GIBB, Frederick, W., III (US)
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