Spectroscopic scatterometer system
US6483580B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1998 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Mar 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Before the diffraction from a diffracting structure on a semiconductor wafer is measured, where necessary, the film thickness and index of refraction of the films underneath the structure are first measured using spectroscopic reflectometry or spectroscopic ellipsometry. A rigorous model is then used to calculate intensity or ellipsometric signatures of the diffracting structure. The diffracting structure is then measured using a spectroscopic scatterometer using polarized and broadband radiation to obtain an intensity or ellipsometric signature of the diffracting structure. Such signature is then matched with the signatures in the database to determine the grating shape parameters of the structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.