Method and apparatus for measuring electron beam effective focus
US5726919A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1995 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Nov 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/3053
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for measuring effective focus of an electron beam directed at a target. The electron beam imparts heat flux into the target to effect a target surface temperature profile thereon. A mathematical process model is used to predict an initial iteration of the temperature profile based on operating beam parameters and based on heat transfer behavioral relationships of the target. The temperature profile is optically measured and then compared with the initial iteration to obtain a residual error therebetween. The predicted temperature profile is iterated by varying the beam focus operating parameter until the residual error is less than a predetermined value for determining the effective beam focus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.