Particle source with selectable beam current and energy spread
First Claim
1. A particle-optical apparatus equipped with a particle source, which particle source is embodied to generate at least one beam of electrically charged particles (16) and which particle source is provided with:
- a particle-emitting surface for emission of the electrically charged particles;
a lens for formation of an image of the particle-emitting surface;
a beam-limiting diaphragm for limitation of said beam of particles, and;
an energy-selecting diaphragm at the location of the image, characterized in thatthe beam-limiting diaphragm is embodied in such a way that said beam is a beam that goes through the lens eccentrically.
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Accused Products
Abstract
The invention describes a particle source in which energy selection occurs. The energy selection occurs by sending a beam of electrically charged particles 13 eccentrically through a lens 6. As a result of this, energy dispersion will occur in an image 15 formed by the lens 6. By projecting this image 15 onto a diaphragm 7, it is possible to only allow particles in a limited portion of the energy spectrum to pass. Consequently, the passed beam 16 will have a reduced energy spread. By adding a deflection unit 10, this particle beam 16 can be deflected toward the optical axis 2. One can also elect to deflect a beam 12 going through the middle of the lens 6—and having, for example, greater current—toward the optical axis.
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Citations
16 Claims
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1. A particle-optical apparatus equipped with a particle source, which particle source is embodied to generate at least one beam of electrically charged particles (16) and which particle source is provided with:
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a particle-emitting surface for emission of the electrically charged particles; a lens for formation of an image of the particle-emitting surface; a beam-limiting diaphragm for limitation of said beam of particles, and; an energy-selecting diaphragm at the location of the image, characterized in that the beam-limiting diaphragm is embodied in such a way that said beam is a beam that goes through the lens eccentrically. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9)
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5. A particle source for use in a particle-optical apparatus, the particle source configured to generate at least one beam of electrically charged particles, the particle source comprising:
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a particle-emitting surface for emission of the electrically charged particles; a lens for formation of an image of the particle-emitting surface; a beam-limiting diaphragm for limitation of said beam of particles, the beam-limiting diaphragm is embodied in such a way that said beam is a beam that goes through the lens eccentrically; and an energy-selecting diaphragm at the location of the image. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification