Method for measuring dimensions and optical system using the same
US7619753B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 19, 2006 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Jun 21, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of measuring dimensions for an optical system to measure the critical dimension of a sample object according to this aspect of the present invention includes the steps of preparing a plurality of standard objects, selecting a predetermined focus metric algorithm, performing an analyzing process on each standard object to generate a plurality of focus metric distributions using the predetermined focus metric algorithm, analyzing the focus metric distributions to determine a target order, generating a reference relation, acquiring a measured characteristic value from the sample object, and determining the critical dimension of the sample object based on the measured characteristic value and the reference relation. Each standard object has a grating-shaped standard pattern with a predetermined pitch and line width. The focus metric algorithm is a gradient energy method, a Laplacian method, a standard deviation method, or a contrast method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.