Pellicle aging estimation and particle removal from pellicle via acoustic waves
US9933699B2 · kind B2 · utility
2Cited by
21References
20Claims
0Family size
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Key dates
| Filing date | Mar 16, 2015 |
| Grant date | Apr 3, 2018 |
| Priority date | — |
| Expiry date | Nov 3, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/62
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A pellicle is disposed over a lithography mask. An acoustic wave generator is placed over the pellicle. The acoustic wave generator is configured to generate acoustic waves to cause the pellicle to vibrate at a target resonance frequency. A resonance detection tool is configured to detect an actual resonance frequency of the pellicle in response to the acoustic waves. One or more electronic processors are configured to estimate an age condition of the pellicle as a function of a shift of the actual resonance frequency from the target resonance frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.