Spectroscopic beam profile overlay metrology
US10101676B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2016 |
| Grant date | Oct 16, 2018 |
| Priority date | — |
| Expiry date | Sep 21, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7046
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A spectroscopic beam profile metrology system simultaneously detects measurement signals over a large wavelength range and a large range of angles of incidence (AOI). In one aspect, a multiple wavelength illumination beam is reshaped to a narrow line shaped beam of light that is projected onto an overlay metrology target such that the direction of the line shaped beam is aligned with the direction of extent of a grating structure of the overlay metrology target. Collected light is dispersed across a detector according to AOI in one direction and according to wavelength in another direction. The measured signal at each detector pixel is associated with a particular AOI and wavelength. The collected light includes first order diffracted light, zero order diffracted light, or a combination thereof. In some embodiments, first order diffracted light and zero order diffracted light are detected over separate areas of the detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.