Particle optical system

Patent metadata

Field	Value
Publication number	US-9349571-B2
Application number	US-201414481823-A
Country	US
Kind code	B2
Filing date	Sep 9, 2014
Priority date	Sep 9, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A particle optical system comprises a beam generating system ( 3 ) configured to generate a plurality of particle beams ( 5 ) and to direct the plurality of particle beams ( 5 ) onto an object plane ( 7 ), a first deflector arrangement ( 35 ) arranged in the beam path of the particle beams ( 5 ) upstream of the object plane ( 7 ) and configured to deflect the plurality of particle beams ( 5 ) before they are incident on the object plane ( 7 ), an object holder ( 15 ) configured to hold an object ( 17 ) to be inspected in the object plane ( 7 ), a plurality of detectors ( 27 ) configured to receive and to detect the plurality of particle beams ( 5 ) having traversed the object plane ( 7 ), wherein the detectors are arranged in a detection plane ( 21 ) on a side of the object plane ( 7 ) opposite to the beam generating system ( 3 ), at least one first particle optical lens ( 19 ) configured to collect particles of the particle beams emanating from the object plane on the detectors ( 27 ), and a controller ( 31 ) configured to control the first deflector arrangement ( 35 ) in order to deflect locations of incidence ( 9 ) of the particle beams ( 5 ) on the object plane ( 7 ) by deflecting the particle beams ( 5 ).

First claim

What is claimed is:

1. A particle optical system comprising:
a beam generating system configured to generate a plurality of separate particle beams and to direct the plurality of particle beams onto an object plane;
a first deflector arrangement arranged in the beam path of the particle beams upstream of the object plane and configured to deflect the plurality of particle beams before they are incident on the object plane;
an object holder configured to hold an object to be inspected in the object plane;
a plurality of detectors configured to receive and to detect the plurality of particle beams having traversed the object plane, wherein particle sensitive surfaces of the detectors are arranged in a detection plane on a side of the object plane opposite to the beam generating system;
at least one first particle optical lens configured to collect particles of the particle beams emanating from the object plane on the detectors; and
a controller configured to control the first deflector arrangement in order to deflect locations of incidence of the particle beams on the object plane by deflecting the particle beams.

2. The particle optical system according to claim 1 , further comprising a second deflector arrangement arranged in the beam path of the particle beams between the object plane and the detection plane and configured to deflect the plurality of particle beams having traversed the object plane;
wherein the controller is further configured to control the second deflector arrangement such that each particle beam is directed onto a separate same detector by deflecting the
particle beams deflected by the first deflector arrangement and having traversed the object plane, irrespective of a deflection amount provided by the first deflector arrangement.

3. The particle optical system according to claim 1 , wherein the beam generating system comprises a separate particle source for each generated particle beam.

4. The particle optical system according to claim 1 , wherein the beam generating system comprises a particle source for generating a primary particle beam and a multi-aperture plate having a plurality of apertures arranged in the beam path of the primary particle beam in order to generate the plurality of particle beams.

5. The particle optical system according to claim 1 , wherein the beam generating system comprises a plurality of second particle optical lenses, wherein at least one of the second particle optical lenses is arranged in a beam path of each of the plurality of particle beams.

6. The particle optical system according to claim 5 , wherein the second particle optical lenses comprise apertures of a multi-aperture plate.

7. The particle optical system according to claim 1 , wherein the beam generating system is configured to focus each of the plurality of particle beams in the object plane.

8. The particle optical system according to claim 1 , wherein the particle optical system is free of a particle optical lens arranged in the beam path upstream of the object plane and traversed by all particle beams.

9. The particle optical system according to claim 1 , wherein the beam generating system comprises at least one third particle optical lens arranged in the beam path upstream of the object plane and traversed by all particle beams.

10. The particle optical system according to claim 1 , wherein the at least one first particle optical lens is configured to image the object plane into the detection plane.

11. The particle optical system according to claim 10 , wherein the at least one first particle optical lens is configured to image the object plane into the detection plane with a magnification greater than 2.

12. The particle optical system according to claim 10 , wherein the at least one first particle optical lens comprises two particle optical lens elements, wherein a first particle optical lens element of the two particle optical lens elements is arranged at a distance from the object plane corresponding to a focal length of the first lens element,
wherein a second particle optical lens element of the two particle optical lens elements is arranged at a distance from the first particle optical lens element corresponding to a sum of the focal length of the first particle optical lens element and a focal length of the second particle optical lens element, and
wherein the detection plane is arranged at a distance from the second particle optical lens element corresponding to the focal length of the second particle optical lens element.

13. The particle optical system according to claim 12 , wherein the second deflector arrangement comprises a deflector arranged in the beam path of the plurality of the particle beams between the first and second lens elements and at a distance from the first particle optical lens element corresponding to the focal length of the first particle optical lens element.

14. The particle optical system according to claim 12 , further comprising a plate arranged in the beam path of the plurality of the particle beams between the first and second lens elements and at a distance from the first lens element corresponding to the focal length of the first particle optical lens element, wherein the plate has a circular aperture or a ring-shaped aperture.

15. The particle optical system according to claim 1 , wherein a plurality of the first particle optical lenses is provided, and wherein one of the first particle optical lenses is arranged in a beam path of each of the plurality of particle beams having traversed the object plane.

16. The particle optical system according to claim 15 , wherein the first particle optical lenses comprise apertures of a multi-aperture plate.

17. The particle optical system according to claim 1 , wherein the first deflector arrangement comprises two deflectors arranged at a distance from each other in the beam path of the plurality of the particle beams.

18. The particle optical system according to claim 1 , wherein at least one of the first deflector arrangement and the second deflector arrangement comprises a plurality of electrodes distributed in a circumferential direction about the plurality of particle beams.

Assignees

• Zeiss Carl Microscopy Gmbh

Inventors

• Kemen Thomas
• Anger Pascal
• Zeidler Dirk
• Benner Gerd

Classifications

• H01J37/1472

  Deflecting along given lines · CPC title

• H01J2237/2802

  Transmission microscopes · CPC title

• H01J37/04

  Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement {(H01J37/32009, H01J37/32623, H01J37/3266, H01J37/32697 take precedence; electron or ion-optical systems for localised treatment of objects H01J37/3007)} · CPC title

• H01J37/265 Primary

  Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination · CPC title

• H01J37/10

  Lenses · CPC title