Self-moire target design principles for measuring unresolved device-like pitches
US9864209B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 2016 |
| Grant date | Jan 9, 2018 |
| Priority date | — |
| Expiry date | May 19, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70616
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Metrology targets and methods are provided, which provide self-Moiré measurements of unresolved target features, i.e., interaction of electromagnetic fields re-scattered off elements within a single target layer provides signals with Moiré pitches that are measurable, although the actual target pitches are unresolved and possibly device-like. Targets comprise cell(s) with interlaced lines of elements having different device-like pitches which are selected to yield resolved Moiré pitch(es). Different target designs are presented for scatterometry and imaging metrology measurements, as well as for critical dimension, dose and focus, and pitch walk measurements—of device-like targets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.