Lithographic dose characterization
US10921716B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 2019 |
| Grant date | Feb 16, 2021 |
| Priority date | — |
| Expiry date | Oct 8, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Methods for determining unintentional exposure dose such as flare or out-of-band radiation of a lithography tool are provided. The methods generally include performing a series of open frame exposures with the lithography tool on a substrate having a photoresist therein to produce a primary array of controlled exposure dose blocks in the photoresist. Secondary exposure blocks are embedded within the primary array. The resultant open frame images are scanned with oblique light and the light scattered from the substrate surface captured. A haze map is created from a background signal of the captured scattered light data and converted to a graphical image file. Analyzing the graphical image file can be used to correlate any localized changes in the effective dose of the primary exposure array to the impact of secondary exposure blocks to characterize flare or out-of-band radiation associated with the exposure dose.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.