Method for correcting electronic proximity effects using off-center scattering functions
US9224577B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 16, 2012 |
| Grant date | Dec 29, 2015 |
| Priority date | — |
| Expiry date | Oct 12, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31769
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for projecting an electron beam, used notably in direct or indirect writing lithography and in electronic microscopy. Proximity effects created by the forward and backward scattering of the electrons of the beam in interaction with the target must be corrected. For this, the convolution of a point spread function with the geometry of the target is conventionally used. At least one of the components of the point spread function has its maximum value not located on the center of the beam. Preferably, the maximum value is instead located on the backward scattering peak. Advantageously, the point spread function uses gamma distribution laws.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.