Aberration evaluation pattern, aberration evaluation method, aberration correction method, electron beam drawing apparatus, electron microscope, master, stamper, recording medium, and structure
US8158310B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 27, 2007 |
| Grant date | Apr 17, 2012 |
| Priority date | — |
| Expiry date | Sep 8, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24479
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of evaluating astigmatism of an irradiation system irradiating an electron beam is disclosed. In this method, a figure pattern consisting of plural (for example, four) concentric circles is formed on a reference sample “WP” and an image (scanned image) is formed based on an electron signal obtained by scanning the electron beam onto the reference sample “WP”. In the scanned image, the image has a blur in a region with its longitudinal direction parallel to the generating direction of the astigmatism and the size of the blur depends on magnitude of the astigmatism. Therefore, the direction and the magnitude of the astigmatism of the irradiation system of an irradiation apparatus can be detected based on the obtained scanned image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.