Objective lens arrangement

Patent metadata

Field	Value
Publication number	US-11264198-B2
Application number	US-201816160906-A
Country	US
Kind code	B2
Filing date	Oct 15, 2018
Priority date	Oct 15, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

An objective lens arrangement that may include a magnetic lens and an electrostatic lens. The magnetic lens may include one or more coils, an upper polepiece and a lower polepiece. The electrostatic lens may include an upper electrode, an internal lower electrode and an external lower electrode. A majority of the internal lower electrode may be surrounded by a majority of the external lower electrode. The upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement. An area of a bottom aperture of the external lower electrode may not exceed an area of a bottom aperture of the internal lower electrode.

First claim

We claim:

1. An objective lens arrangement, comprising:
a magnetic lens; and
an electrostatic lens;
wherein the magnetic lens comprises one or more coils, an upper polepiece and a lower polepiece;
wherein the electrostatic lens comprises an upper electrode, an internal lower electrode and an external lower electrode; wherein a majority of the internal lower electrode is surrounded by a majority of the external lower electrode;
wherein the upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement;
wherein the internal lower electrode includes an external interface that electrically couples the internal lower electrode to the upper electrode; and
wherein an area of a bottom aperture of the external lower electrode does not exceed an area of a bottom aperture of the internal lower electrode.

2. The objective lens arrangement according to claim 1 wherein an exterior of the majority of the internal lower electrode is spaced apart from an interior of the majority of the external lower electrode by a distance that exceeds an arcing distance.

3. The objective lens arrangement according to claim 1 wherein the internal lower electrode comprises a cylindrical portion that is positioned above a conical frustum shaped portion.

4. The objective lens arrangement according to claim 3 wherein a height of the cylindrical portion equals a height of the conical frustum shaped portion.

5. The objective lens arrangement according to claim 3 wherein a height of the cylindrical portion differs from a height of the conical frustum shaped portion.

6. The objective lens arrangement according to claim 3 wherein the external interface of the internal lower electrode is connected to an exterior of the cylindrical portion.

7. The objective lens arrangement according to claim 1 wherein the external interface of the internal lower electrode is connected to the upper electrode.

8. The objective lens arrangement according to claim 1 wherein the upper polepiece is electrically coupled to the upper electrode and wherein the lower polepiece is electrically isolated from the external lower electrode.

9. The objective lens arrangement according to claim 1 wherein the electrostatic lens consists of the upper electrode, the internal lower electrode and the external lower electrode.

10. An objective lens arrangement, comprising:
a magnetic lens; and
an electrostatic lens;
wherein the magnetic lens comprises one or more coils, an upper polepiece and a lower polepiece;
wherein the electrostatic lens comprises an upper electrode, an internal lower electrode and an external lower electrode; wherein a majority of the internal lower electrode is surrounded by a majority of the external lower electrode;
wherein the upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement;
wherein the upper polepiece is electrically coupled to the upper electrode and wherein the lower polepiece is electrically isolated from the external lower electrode; and
wherein an area of a bottom aperture of the external lower electrode does not exceed an area of a bottom aperture of the internal lower electrode.

11. The objective lens arrangement according to claim 10 wherein an exterior of the majority of the internal lower electrode is spaced apart from an interior of the majority of the external lower electrode by a distance that exceeds an arcing distance.

12. The objective lens arrangement according to claim 10 wherein the internal lower electrode comprises a cylindrical portion that is positioned above a conical frustum shaped portion.

13. The objective lens arrangement according to claim 10 wherein the internal lower electrode includes an external interface that electrically couples the internal lower electrode to the upper electrode.

14. The objective lens arrangement according to claim 13 wherein the external interface is connected to the upper electrode.

15. An objective lens arrangement, comprising:
a magnetic lens; and
an electrostatic lens;
wherein the magnetic lens comprises one or more coils, an upper polepiece and a lower polepiece;
wherein the electrostatic lens comprises an upper electrode, an internal lower electrode and an external lower electrode; wherein a majority of the internal lower electrode is surrounded by a majority of the external lower electrode;
wherein the upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement;
wherein the internal lower electrode is electrically coupled to the upper electrode; and
wherein an area of a bottom aperture of the external lower electrode does not exceed an area of a bottom aperture of the internal lower electrode.

16. The objective lens arrangement according to claim 15 wherein an exterior of the majority of the internal lower electrode is spaced apart from an interior of the majority of the external lower electrode by a distance that exceeds an arcing distance.

17. The objective lens arrangement according to claim 15 wherein the internal lower electrode comprises a cylindrical portion that is positioned above a conical frustum shaped portion.

18. The objective lens arrangement according to claim 15 wherein the internal lower electrode includes an external interface that electrically couples the internal lower electrode to the upper electrode.

19. The objective lens arrangement according to claim 18 wherein the external interface is connected to the upper electrode.

Assignees

• Applied Materials Israel Ltd

Inventors

• Petrov Igor
• Rosenberg Zvika
• Bader Arie

Classifications

• H01J37/28

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

• H01J37/145 Primary

  Combinations of electrostatic and magnetic lenses · CPC title