Minimization of electron fogging in electron beam lithography
US6326635A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1999 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | Jul 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3175
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A shield assembly for reducing electron fogging effects in electron beam lithography. This shield, located between an electron beam column final aperture and the beam target, is of multiple vanes with sharp edges pointing towards the electron beam incident point on the target; the vanes are conically shaped and concentric around the electron beam path, which travels through the center of the assembly. Additionally, the sharp edges are such that they present oblique surfaces at the ends of the vanes angled between 10.degree. and 20.degree. relative to the outer vane surface and these oblique surfaces face towards the electron beam path. Furthermore, the shield assembly may also have the vanes angled towards the beam incident point such that the vertex of the conical vane assembly is coincident with the beam incident point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.