Charged Particle Source with Integrated Electrostatic Energy Filter
First Claim
1. A charged particle source with integrated electrostatic energy filter, the charged-particle source for use in a charged-particle apparatus, the charged particle source comprising:
- p1 a charged particle emitter for producing a beam of charged particles around an axis,a beam limiting aperture for selecting a part of the beam produced by the emitter, the beam limiting aperture positioned around the axis, thereby selecting an axial part of the beam,an energy selecting aperture in an energy selective diaphragm for selecting particles with a desired energy spread from the part of the beam that passed through the beam limiting aperture,electrodes for forming a focus of the charged particle emitter on the energy selective diaphragm, andelectrodes for producing electrostatic dipole fields for deflecting the beam,in which the charged particle emitter and the electrodes are arranged round the axis, the axis being a straight axis.
0 Assignments
0 Petitions
Accused Products
Abstract
A charged particle filter with an integrated energy filter, in which the charged particle emitter, the focusing electrodes, and the deflection electrodes are arranged round a straight axis. Where most energy filters used have a highly curved optical axis, and thus use parts with forms that are difficult to manufacture, the source according the invention uses electrodes surrounding a straight optical axis. A beam of charged particles can be deflected quite far from the axis showing respectable energy dispersion at an energy selecting slit without introducing coma or astigmatism that cannot be corrected, provided that some of the are formed as 120°/60°/120°/60°. Such electrodes can be attached to each other by gluing or brazing of ceramic, and then series of a highly concentric bores can be formed by, e.g., spark erosion.
12 Citations
20 Claims
-
1. A charged particle source with integrated electrostatic energy filter, the charged-particle source for use in a charged-particle apparatus, the charged particle source comprising:
- p1 a charged particle emitter for producing a beam of charged particles around an axis,
a beam limiting aperture for selecting a part of the beam produced by the emitter, the beam limiting aperture positioned around the axis, thereby selecting an axial part of the beam, an energy selecting aperture in an energy selective diaphragm for selecting particles with a desired energy spread from the part of the beam that passed through the beam limiting aperture, electrodes for forming a focus of the charged particle emitter on the energy selective diaphragm, and electrodes for producing electrostatic dipole fields for deflecting the beam, in which the charged particle emitter and the electrodes are arranged round the axis, the axis being a straight axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 20)
- p1 a charged particle emitter for producing a beam of charged particles around an axis,
-
12. A charged particle source with integrated electrostatic energy filter, the charged-particle source for use in a charged-particle apparatus, the charged particle source comprising:
-
a charged particle emitter for producing a beam of charged particles along a first axis; a beam limiting aperture for selecting a part of the beam produced by the emitter, the beam limiting aperture positioned around the axis, thereby selecting an axial part of the beam; an energy selecting aperture in an energy selective diaphragm for selecting particles with a desired energy spread from the part of the beam that passed through the beam limiting aperture; electrodes for forming a focus of the charged particle emitter on the energy selective diaphragm; and electrodes for producing electrostatic dipole fields for deflecting the beam; wherein the electrodes for forming a focus and the electrodes for deflecting the beam are all arranged to be concentric with the first axis. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
Specification