Integrated light optics and gas delivery in a charged particle lens

• US 9,478,390 B2
• Filed: 06/30/2014
• Issued: 10/25/2016
• Est. Priority Date: 06/30/2014
• Status: Active Grant

• Current Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Original Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Inventors: Parker, N. William, Straw, Marcus, Filevich, Jorge, Botman, Aurelien Philippe Jean Maclou, Randolph, Steven, Chandler, Clive, Utlaut, Mark
• Primary Examiner(s): Ippolito, Nicole
• Assistant Examiner(s): LUCK, SEAN M
• Application Number:
  US14/320,560
• Publication Number:
  US 20150380205A1
• Time in Patent Office: 848 Days
• US Class Current: 1/1
• CPC Class Codes: H01J 2237/006 Details of gas supplies, e.g. in an ion source, to a beam line, to a specimen or to a workpiece, H01J37/3244 takes precedence; environmental cells for electron microscopes H01J2237/2003; microscopes with environmental specimen chamber H01J2237/2608
• CPC Class Codes: H01J 2237/31749 Focused ion beam
• CPC Class Codes: H01J 37/12 electrostatic
• CPC Class Codes: H01J 37/228 whereby illumination and light collection take place in the same area of the discharge

Abstract

A method and apparatus for directing light or gas or both to a specimen positioned within about 2 mm from the lower end of a charged particle beam column. The charged particle beam column assembly includes a platform defining a specimen holding position and has a set of electrostatic lenses each including a set of electrodes. The assembly includes a final electrostatic lens that includes a final electrode that is closest to the specimen holding position. This final electrode defines at least one internal passageway having a terminus that is proximal to and directed toward the specimen holding position.

Claims

1. A charged particle beam column assembly, comprising:

a) a platform defining a specimen holding position;

b) an electrostatic lens comprising a set of electrodes including a final plate electrode that is closest to the specimen holding position; and

c) wherein said final plate electrode defines at least one passageway for transmitting light, the passageway being substantially parallel to the bottom surface of the plate electrode, the light being guided within the passageway in an overall direction parallel to the bottom surface of the plate electrode,

wherein the passageway is configured to either guide light from a light emitter to the specimen to illuminate the specimen

or to guide the light illuminated from the specimen to a detector for detecting.

2. The assembly of claim 1, wherein said passageway includes an additional terminus that houses a light detector.

3. The assembly of claim 1, wherein said passageway comprises a first light pathway and wherein said final electrode defines a second light pathway in addition to said first light pathway.

4. The assembly of claim 3, wherein said first light pathway terminates in a light source and said second light pathway terminates in a light detector.

5. The assembly of claim 1, wherein said final plate electrode comprises metal and wherein said internal passageway comprises tubular void space in the metal.

6. The assembly of claim 5, wherein the metal comprises a titanium alloy.

7. The assembly of claim 5, wherein the internal surfaces of the void space are polished to increase reflection.

8. The assembly of claim 1, further comprising a light pipe extending through said internal passageway.

9. The assembly of claim 1, wherein said internal passageway comprises a gas pathway and includes an additional terminus that is connected to a gas source.

10. The assembly of claim 9, wherein said internal passageway is a first gas pathway and wherein said final plate electrode defines a second gas pathway in addition to said first gas pathway.

11. The assembly of claim 10, wherein said first gas pathway terminates in a gas source and said second gas pathway terminates in a gas detector.

12. The assembly of claim 10, wherein said first gas pathway terminates in a first gas source and a said second gas pathway terminates in a second gas source.

13. The assembly of claim 1, wherein said internal passageway comprises both a gas pathway and a light pathway and includes a terminus that communicates with both a gas source and a light source.

21. The charged particle beam column assembly of claim 1 in which the final plate electrode is positioned within 2 mm of a specimen surface.

22. The charged particle beam column assembly of claim 1 in which the internal passageway is oriented transverse to the axis of the charged particle beam.

23. The charged particle beam column assembly of claim 1 in which the internal passageway is configured so that the light is reflected multiple times as it traverses the passageway.

14. A method of directing light to or from a predetermined specimen position in a charged particle beam system having an electrostatic lens including a set of electrodes including a final plate comprising:

a) providing a light path to or from the predetermined specimen position through an internal passageway of a final plate electrode, the internal passageway being substantially parallel to the bottom surface of the plate electrode, the light being guided within the internal passageway in an overall direction parallel to the bottom surface of the final plate electrode; and

b) emitting light into the light path,

wherein the light path is configured to either guide light from a light emitter to the specimen to illuminate the specimen

or to guide the light illuminated from the specimen to a detector for detecting.

15. The method of claim 14, further comprising providing an additional light path to the predetermined specimen position;

wherein emitting light into the light path comprises directing light to the specimen along the light path; and

further comprising receiving light from the specimen through the additional light path.

16. The method of claim 14, wherein said the internal passageway comprises polished surfaces, and wherein said light reflects from said polished surfaces as it travels to or from said specimen.

17. The method of claim 14, wherein the final plate electrode comprises a titanium alloy.

18. The method of claim 14, wherein at least one additional light path is provided and further comprising emitting into the at least one additional light path.

19. The method of claim 14 further comprising directing a gas to the predetermined specimen position through the internal passageway.

20. The method of claim 19, wherein the internal passageway comprises a first gas pathway and wherein the gas is a first gas, and further comprising passing a second gas through a second gas pathway to the predetermined specimen position.