Automated spatial flipping apparatus and system for photomasks and photomasks with pellicles
US7962242B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2008 |
| Grant date | Jun 14, 2011 |
| Priority date | — |
| Expiry date | Oct 23, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/66
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A spatial photomask flipper provides up to four access gates for an unloading of a clamped photomask after its reorientation along a single photomask transfer axis. The clamping frames holding the photomask are secured by a locking control cam that prevents their inadvertent opening in any other but the two main flip orientations. The flipper is part of an automated system including a digital camera and an image recognition algorithm that interpret an arbitrary initial photomask loading orientation from a circumferential photomask identification number. An eventual pellicle on the photomask may be also automatically detected via a pellicle detection sensor. Alternately, the digital camera may be employed for pellicle detection together with a pellicle detection algorithm that processes the digital image for well known components of the pellicle such as the pellicle frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.