Methods and apparatus for measuring semiconductor device overlay using X-ray metrology
US9885962B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2014 |
| Grant date | Feb 6, 2018 |
| Priority date | — |
| Expiry date | Nov 3, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed are apparatus and methods for determining overlay error in a semiconductor target. For illumination x-rays having at least one angle of incidence (AOI), a correlation model is obtained, and the correlation model correlates overlay error of a target with a modulation intensity parameter for each of one or more diffraction orders (or a continuous diffraction intensity distribution) for x-rays scattered from the target in response to the illumination x-rays. A first target is illuminated with illumination x-rays having the at least one AOI and x-rays that are scattered from the first target in response to the illumination x-rays are collected. An overlay error of the first target is determined based on the modulation intensity parameter of the x-rays collected from the first target for each of the one or more diffraction orders (or the continuous diffraction intensity distribution) and the correlation model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.