Lateral shift measurement using an optical technique
US7301163B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2006 |
| Grant date | Nov 27, 2007 |
| Priority date | — |
| Expiry date | Oct 16, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Alignment of layers during manufacture of a multi-layer sample is controlled by applying optical measurements to a measurement site in the sample. The measurement site includes two diffractive structures located one above the other in two different layers, respectively. The optical measurements include at least two measurements with different polarization states of incident light, each measurement including illuminating the measurement site so as to illuminate one of the diffractive structures through the other. The diffraction properties of the measurement site are indicative of a lateral shift between the diffractive structures. The diffraction properties detected are analyzed for the different polarization states of the incident light to determine an existing lateral shift between the layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.