Charged particle beam device, objective lens module, electrode device, and method of inspecting a specimen

Patent metadata

Field	Value
Publication number	US-10991544-B2
Application number	US-201916425094-A
Country	US
Kind code	B2
Filing date	May 29, 2019
Priority date	May 29, 2019
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A charged particle beam device for inspecting a specimen is described. The charged particle beam device includes a beam source for emitting a charged particle beam, an electrode for influencing the charged particle beam, and a damping unit provided on the electrode for damping vibrations of the electrode. Further, an objective lens module with an electrode is described, wherein a damping unit is provided on the electrode. Further, an electrode device is described, wherein a mass damper is mounted on a disk-shaped electrode body of the electrode device.

First claim

The invention claimed is:

1. A charged particle beam device for inspecting a specimen, comprising:
a beam source for emitting a charged particle beam;
an electrode for influencing the charged particle beam; and
a damping unit provided on the electrode for damping vibrations of the electrode,
wherein the damping unit is mounted at the electrode and not between the electrode and another object that can vibrate relative to each other,
wherein the damping unit is a mass damper that comprises a damping mass and an elastic element arranged at least partially between the damping mass and the electrode, and
wherein the damping unit is configured to dampen predetermined vibration modes of the electrode.

2. The charged particle beam device of claim 1 , wherein the damping mass is held at a distance from the electrode by a connection element, and the elastic element is provided in contact with the electrode and the damping mass in a gap between the electrode and the damping mass.

3. The charged particle beam device of claim 2 , wherein the connection element is a screw, pin or bolt, and the elastic element is an elastomer ring or O-ring surrounding the connection element.

4. The charged particle beam device of claim 1 , wherein a surface of the damping unit protruding away from the electrode is at least one of rounded, edge- and corner-free, and polished.

5. The charged particle beam device of claim 1 , wherein the electrode comprises a disk-shaped electrode body and a plurality of mass dampers mounted on the disk-shaped electrode body.

6. The charged particle beam device of claim 5 , wherein the plurality of mass dampers comprise four, six or more mass dampers mounted on a circumferential edge region of the disk-shaped electrode body, respectively.

7. The charged particle beam device of claim 1 , wherein the electrode is configured for at least one of focusing the charged particle beam on the specimen and generating an extraction field for signal electrons above the specimen.

8. The charged particle beam device of claim 1 , wherein the charged particle beam device comprises an objective lens module for focusing the charged particle beam on the specimen, and the electrode is a part of the objective lens module arranged close to the specimen.

9. The charged particle beam device of claim 1 , wherein the electrode is held at a housing of an objective lens module by at least one axially extending holder.

10. The charged particle beam device of claim 9 , wherein the electrode is configured for a voltage difference of 1 kV or more with respect to the housing of the objective lens module.

11. The charged particle beam device of claim 1 , wherein the electrode has a disk-shaped electrode body with a circumferential edge region having a first thickness and a center region with at least one opening for the charged particle beam having a second thickness smaller than the first thickness.

12. The charged particle beam device of claim 11 , wherein the first thickness is 5 mm or more, and wherein the second thickness is 3 mm or less.

13. The charged particle beam device of claim 1 , wherein the damping unit is configured to dampen vibration modes of the electrode in a frequency range from 300 Hz to 2000 Hz.

14. The charged particle beam device of claim 1 , wherein the damping unit is configured to dampen drum modes of the electrode.

15. The charged particle beam device of claim 1 , wherein the damping unit is configured to dampen lateral modes of the electrode.

16. The charged particle beam device of claim 1 , wherein the electrode comprises an electrode body, and the damping unit is placed on the electrode body.

17. The charged particle beam device of claim 1 , wherein the damping unit is not in contact with a support of the electrode.

18. An objective lens module for focusing a charged particle beam on a specimen, comprising:
a housing;
an electrode;
at least one axially extending holder which holds the electrode at the housing; and
a damping unit provided on the electrode for damping vibrations of the electrode,
wherein the damping unit is mounted at the electrode and not between the electrode and another object that can vibrate relative to each other,
wherein the damping unit is a mass damper that comprises a damping mass and an elastic element arranged at least partially between the damping mass and the electrode, and
wherein the damping unit is configured to dampen predetermined vibration modes of the electrode.

19. An electrode device for influencing a charged particle beam in a charged particle beam device, comprising:
an electrode body; and
a mass damper mounted on the electrode body for damping vibrations of the electrode body,
wherein the mass damper is mounted at the electrode body and not between the electrode body and another object that can vibrate relative to each other,
wherein the mass damper comprises a damping mass and an elastic element arranged at least partially between the damping mass and the electrode body, and
wherein the damping unit is configured to dampen predetermined vibration modes of the electrode body.

20. A method of inspecting a specimen with a charged particle beam device, comprising:
generating a charged particle beam propagating along an optical axis;
influencing the charged particle beam with an electrode; and
damping vibrations of the electrode with a damping unit provided on the electrode,
wherein the damping unit is mounted at the electrode and not between the electrode and another object that can vibrate relative to each other,
wherein the damping unit is a mass damper that comprises a damping mass and an elastic element arranged at least partially between the damping mass and the electrode, and
wherein the damping unit is configured to dampen predetermined vibration modes of the electrode.

21. The method of claim 20 , wherein the electrode is arranged at a distance of 2 cm or less from the specimen and generates an extraction field for signal charged particles above the specimen.

Assignees

• Ict Integrated Circuit Testing Ges Fuer Halbleiterprueftechnik Mbh

Inventors

• Firnkes Matthias
• Breuer John
• Lampersberger Florian
• Kaupp Hanno
• Lanio Stefan

Classifications

• H01J37/28

  with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} · CPC title

• H01J37/1471

  for centering, aligning or positioning of ray or beam · CPC title

• H01J37/04 Primary

  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

• G01N23/2251

  using incident electron beams, e.g. scanning electron microscopy [SEM] · CPC title

• H01J37/145

  Combinations of electrostatic and magnetic lenses · CPC title