Method of and apparatus for inspecting reticle for defects
US6084664A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Nov 2, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/84
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A reticle inspecting apparatus for inspecting a reticle for defects has a transparent or translucent substrate, a circuit pattern formed on the front surface of the substrate, and a phase shifter formed of a light-transmissive film on the front surface of the substrate. In the apparatus, a detection optical system is disposed so as not to gather directly reflected light and directly transmitted light and so as to gather scattered light and diffracted light which has been scattered and diffracted, respectively, by the reticle. This detection optical system is capable of separating the gathered light by direction of illumination using detectors, and spatial filters disposed respectively on Fourier transform planes to intercept light diffracted by straight edges of the circuit pattern, so as to form images of gathered light on the detectors. A signal processing system having a signal processing unit calculates data concerning defects on the basis of the output signals of the detectors and displays the calculated data on a display.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.