Method and apparatus for measurements of patterned structures
US6476920B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2000 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Jul 20, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring at least one desired parameter of a patterned structure having a plurality of features defined by a certain process of its manufacturing. The structure represents a grid having at least one cycle formed of at least two locally adjacent elements having different optical properties in respect of incident radiation. An optical model is provided, which is based on at least some of the features of the structure defined by a certain process of its manufacturing, and on the relation between a range of the wavelengths of incident radiation to be used for measurements and a pitch of the structure under measurements. The model is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure. A measurement area, which is a grid cycles containing area and is substantially larger than a surface area of the structure defined by one grid cycle, is located and spectrophotometric measurements are applied to the measurement area, by illuminating it with incident radiation of a preset substantially wide …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.