Accelerator-decelerator electrostatic lens for variably focusing and mass resolving an ion beam in an ion implanter
US5780863A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1997 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Apr 29, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/1207
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrostatic triode lens (36) is provided for use in an ion implantation system (10). The lens includes a terminal electrode (37) and an adjustable lens subassembly (40) comprising a suppression electrode (38) and a resolving electrode (39), each having matched curved surfaces (108, 110). The lens subassembly is positioned near the terminal electrode where the beam has a minimal waist in a first (dispersive) plane. Such positioning minimizes the required gaps between electrodes, and thus, helps minimize beam blow-up and the electron depletion region in the deceleration mode of operation. The suppression and resolving electrodes each have first and second portions (38A and 38B, 39A and 39B) separated by a gap (d38, d39). A movement mechanism (60, 62) simultaneously moves the first portions of the suppression and resolving electrodes (38A, 39A) toward and away from the second portions of the suppression and resolving electrodes (38B, 39B), respectively, to adjust the gaps (d38, d39) therebetween. The adjustable lens subassembly (40) conditions the beam output by the terminal electrode (37) by (i) variably focusing the beam in mutually orthogonal (dispersive and non-dispersive) pl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.