Optical system and method for measuring parameters of patterned structures in micro-electronic devices
US11512943B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 2016 |
| Grant date | Nov 29, 2022 |
| Priority date | — |
| Expiry date | Jan 11, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8438
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical system and method are presented for use in measurements on an upper surface of a layered sample when located in a measurement plane. The optical system is configured as a normal-incidence system having an illumination channel and a collection channel, and comprises an objective lens unit and a light propagation affecting device. The objective lens unit is accommodated in the illumination and collection channels, thereby defining a common optical path for propagation of illuminating light from the illumination channel toward an illuminating region in the measurement plane and for propagation of light returned from measurement plane to the collection channel. The light propagation affecting device comprises an apertured structure located in at least one of the illumination and collection channels, and configured to provide angular obscuration of light propagation path for blocking angular segments associated with light propagation from regions outside the illuminated region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.