Test pattern and method of evaluating the transfer properties of a test pattern
US7354684B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 2007 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Mar 5, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A test pattern or set of patterns, a method of evaluating the transfer properties of the pattern, and a method of determining a parameter of a transfer process (e.g., imaging process) making use of the test pattern is provided. With the test pattern, the impact of line edge roughness on a transferred pattern may be analyzed. For example, the test pattern may be based upon a lines/spaces pattern, wherein periodic structures having a well-defined period and amplitude are adjacent to the lines. A photomask is provided with the test pattern and an image of the pattern is obtained. Edges of the image are determined and, therefrom, a set of edge position data are obtained. Edge position data are fitted to a straight line to determine edge position residuals. An amplitude spectrum is calculated dependent upon spatial frequencies to obtain a amplitude/spatial frequency relationship. A ratio of determined maximum is formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.