Method for calculating an intensity integral for use in lithography systems
US7173688B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2004 |
| Grant date | Feb 6, 2007 |
| Priority date | — |
| Expiry date | Feb 7, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70191
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system and method for uniformity correction such that a defined uniformity specification is met while minimizing a set of selected constraints is provided. The system includes illumination optics, an opto-mechanical correction system, a contrast device, projection optics and a correction module coupled to the correction system. The correction system includes a plurality of adjustable components such as fingers. The correction module is configured to determine adjustments to the components to correct uniformity. A method for discretizing the continuous intensity integral is also provided. The illumination slot is divided into a grid having multiple grid points. “pupils” are then superimposed onto the grid. Multiple second grids are also defined. Each ““pupil”” is mapped to a second grid such that the center of the second grid is coincident with the ““pupil”” center. The continuous intensity integral is then discretized using the first grid, plurality of second grids, and ““pupil”” mappings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.