Scatterometer and method of scatterometry using acoustic radiation
US10845304B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2018 |
| Grant date | Nov 24, 2020 |
| Priority date | — |
| Expiry date | Oct 16, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic scatterometer 502 has an acoustic source 520 operable to project acoustic radiation 526 onto a periodic structure 538 and 540 formed on a substrate 536. An acoustic detector 518 is operable to detect the −1st acoustic diffraction order 528 diffracted by the periodic structure 538 and 540 while discriminating from specular reflection (0th order 532). Another acoustic detector 522 is operable to detect the +1st acoustic diffraction order 530 diffracted by the periodic structure, again while discriminating from the specular reflection (0th order 532). The acoustic source and acoustic detector may be piezo transducers. The angle of incidence of the projected acoustic radiation 526 and location of the detectors 518 and 522 are arranged with respect to the periodic structure 538 and 540 such that the detection of the −1st and +1st acoustic diffraction orders 528 and 530 discriminates from the 0th order specular reflection 532.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.