System and method to adaptively pre-compensate for target material push-out to optimize extreme ultraviolet light production
US9238243B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2012 |
| Grant date | Jan 19, 2016 |
| Priority date | — |
| Expiry date | Jan 3, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/24
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Energy output from a laser-produced plasma (LPP) extreme ultraviolet light (EUV) system varies based on how well the laser beam is focused on droplets of target material to generate plasma at a primary focal spot. Maintaining droplets at the primary focal spot during burst firing is difficult because generated plasma from preceding droplets push succeeding droplets out of the primary focal spot. Current droplet-to-droplet feedback control to re-align droplets to the primary focal spot is relatively slow. The system and method described herein adaptively pre-compensate for droplet push-out by directing droplets to a target position that is offset from the primary focal spot such that when a droplet is lased, the droplet is pushed by the laser beam into the primary focal spot to generate plasma. Over time, the EUV system learns to maintain real-time alignment of droplet position so plasma is generated consistently within the primary focal spot.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.