Charged-particle-beam exposure device and charged-particle-beam exposure method
US6242751A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1999 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Jul 15, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/30472
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.