Particle beam inspector with independently-controllable beams

• US 10,276,346 B1
• Filed: 09/30/2016
• Issued: 04/30/2019
• Est. Priority Date: 03/09/2016
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Duffy, Brian, Azordegan, Amir, Sears, Christopher
• Primary Examiner(s): McCormack, Jason L
• Application Number:
  US15/281,934
• Time in Patent Office: 942 Days
• Field of Search: 250306, 250307, 250311
• CPC Class Codes: H01J 2237/2817 Pattern inspection
• CPC Class Codes: H01J 2237/2826 Calibration
• CPC Class Codes: H01J 37/265 Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

A multi-beam inspection system includes one or more particle beam sources to generate two or more particle beams, a set of particle control elements configured to independently direct the two or more particle beams to a sample, one or more detectors positioned to receive particles emanating from the sample in response to the two or more particle beams, and a controller communicatively coupled to the one or more detectors. The controller includes one or more processors to generate two or more inspection datasets associated with the particles received by the one or more detectors.

Claims

1. A multi-beam inspection system, comprising:

one or more particle beam sources configured to generate two or more particle beams;

a set of particle control elements configured to direct the two or more particle beams to independently selectable positions on a sample through a common focusing element, wherein the set of particle control elements are further configured to direct a first particle beam of the two or more particle beams to a first portion of the sample to emulate at least one of a voltage source or a current source, wherein the set of particle control elements is configured to concurrently direct one or more additional particle beams of the two or more particle beams across one or more additional portions of the sample, wherein the one or more additional portions of the sample include at least some structures electrically connected to the first portion of the sample;

one or more detectors positioned to receive particles emanating from the sample in response to at least one of the two or more particle beams; and

a controller communicatively coupled to the one or more detectors, the controller including one or more processors, the one or more processors configured to execute program instructions configured to cause the one or more processors to;

generate one or more inspection datasets associated with the particles received by the one or more detectors, wherein at least one of the one or more inspection datasets is associated with at least one of the one or more additional portions of the sample.

2. The multi-beam inspection system of claim 1, wherein an inspection dataset of the one or more inspection datasets includes at least one of data associated with the physical layout of a sample surface, data associated with material properties of one or more layers of material on a sample, or data indicative of one or more physical defects identified on the sample.

3. The multi-beam inspection system of claim 1, wherein the one or more particle beam sources generate two or more particle beams having at least one of distinct particle energies, distinct particle energy densities, or distinct landing energies on the sample.

4. The multi-beam inspection system of claim 1, wherein the set of particle control elements comprises:

at least one of a particle focusing element or a particle scanning element.

5. The multi-beam inspection system of claim 4, wherein the set of particle control elements are configured to direct the two or more particle beams to the sample with independently selectable spot sizes.

6. The multi-beam inspection system of claim 1, wherein at least one inspection dataset of the one or more inspection datasets includes imaging data associated with at least one of the one or more additional portions of the sample.

7. The multi-beam inspection system of claim 6, wherein the imaging data associated with at least one of the one or more additional portions of the sample includes voltage contrast imaging data associated with at least one of the one or more additional portions of the sample.

8. The multi-beam inspection system of claim 1, wherein the portion of the sample includes an alignment target.

9. The multi-beam inspection system of claim 8, wherein the alignment target includes an overlay target.

10. The multi-beam inspection system of claim 1, wherein the one or more particle beam sources include at least two particle beam sources.

11. The multi-beam inspection system of claim 10, wherein the one or more particle control elements include a dispersive element configured to combine the two or more particle beams to a common beam path.

12. The multi-beam inspection system of claim 11, wherein the dispersive element comprises:

a magnetic prism array.

13. The multi-beam inspection system of claim 1, wherein the one or more particle beam sources include a single particle beam source.

14. The multi-beam inspection system of claim 13, further comprising:

an aperture having two or more openings configured to split a single particle beam from the single particle beam source into the two or more particle beams.

39. The multi-beam inspection system of claim 1, wherein the second portion of the sample is different than the first portion of the sample.

40. The multi-beam inspection system of claim 1, wherein the independently selectable positions of the two or more particle beams include at least a common position on the sample.

41. The multi-beam inspection system of claim 1, wherein at least one of the inspection datasets associated with the second particle beam includes imaging data of the second portion of the sample influenced by the at least one of the voltage source or the current source emulated by the first particle beam.

15. A multi-beam inspection system, comprising:

one or more particle beam sources configured to generate two or more particle beams including at least a first particle beam and a second particle beam;

a set of particle control elements configured to direct the first particle beam and the second particle beam to independently selectable positions on a sample through a common focusing element;

one or more detectors positioned to receive particles emanating from the sample in response to any of the two or more particle beams; and

a controller communicatively coupled to the one or more detectors, the controller including one or more processors, the one or more processors configured to execute program instructions configured to cause the one or more processors to;

direct the set of particle control elements to scan at least a portion of an alignment target on the sample with the first particle beam;

generate, based on the particles received by the one or more detectors, a first dataset associated with the alignment target;

determine one or more alignment metrics based on the first dataset;

direct, subsequent to scanning the at least a portion of the alignment target, the set of particle control elements to scan at least a portion of one or more structures on the sample with at least the second particle beam, wherein positions of the one or more structures are determined based on the one or more alignment metrics; and

generate, based on the particles received by the one or more detectors, a second dataset associated with the one or more structures on the sample.

16. The multi-beam inspection system of claim 15, wherein the one or more alignment metrics comprise:

at least one of a location or an orientation of the alignment target on the sample.

17. The multi-beam inspection system of claim 15, wherein the one or more alignment metrics comprise:

at least one of relative location data or relative orientation data of the one or more structures with respect to the alignment target.

18. The multi-beam inspection system of claim 15, wherein a dataset of at least one of the first data set or the second dataset includes at least one of data associated with the physical layout of a sample surface, data associated with material properties of one or more layers of material on a sample, or data indicative of one or more physical defects identified on the sample.

19. The multi-beam inspection system of claim 15, wherein the two or more particle beams have at least one of distinct particle energies, distinct particle energy densities, or distinct landing energies on the sample.

20. The multi-beam inspection system of claim 15, wherein the set of particle control elements comprises:

at least one of a particle focusing element or a particle scanning element.

21. The multi-beam inspection system of claim 20, wherein the set of particle control elements are configured to direct the first particle beam to the sample with a first spot size and the second particle beam to the sample with a second spot size different than the first spot size.

22. The multi-beam inspection system of claim 15, wherein the one or more processors are further configured to execute program instructions to cause the one or more processors to:

direct, subsequent to scanning the at least a portion of the alignment target, a particle beam of the two or more particle beams to a first position on the sample to emulate at least one of a voltage source or a current source, wherein at least one structure in the second portion of the sample is electrically connected to the first portion of the sample, wherein the second dataset is influenced by the at least one of the voltage source or the current source emulated by the first particle beam.

23. The multi-beam inspection system of claim 22, wherein the two or more particle beams includes a third particle beam, wherein the particle beam of the two or more particle beams directed to the first position on the sample is the third particle beam.

24. The multi-beam inspection system of claim 22, wherein at least one of the first dataset or the second dataset includes imaging data of the second portion of the sample.

25. The multi-beam inspection system of claim 24, wherein the imaging data of the sample includes voltage contrast imaging data of the sample.

26. The multi-beam inspection system of claim 15, wherein the alignment target includes an overlay target.

27. The multi-beam inspection system of claim 18, wherein the one or more particle beam sources include two particle beam sources.

28. The multi-beam inspection system of claim 18, wherein the one or more particle control elements include a dispersive element configured to combine the two particle beams to a common beam path.

29. The multi-beam inspection system of claim 28, wherein the dispersive element comprises:

a magnetic prism array.

30. The multi-beam inspection system of claim 18, wherein the one or more particle beam sources include a single particle beam source.

31. The multi-beam inspection system of claim 30, further comprising:

an aperture having two openings configured to split a single particle beam from the single particle beam source into the two particle beams.

32. A method for sample inspection, comprising:

generating two or more particle beams;

directing a first particle beam of the two or more particle beams to a first portion of the sample to emulate at least one of a voltage source or a current source;

scanning, concurrent to directing the first particle beam, a second particle beam of the two or more particle beams across a second portion of the sample different than the first portion, wherein at least one structure in the second portion of the sample is electrically connected to the first portion of the sample;

receiving particles emanating from the sample in response to the two or more particle beams; and

generating, based on the received particles emanating from the sample, one or more inspection datasets associated with the received particles emanating from the sample, wherein at least one of the one or more inspection datasets is associated with the second portion of the sample and is indicative of an influence of the at least one of the voltage source or the current source emulated by the first particle beam on the second portion of the sample.

33. The method for sample inspection of claim 32, further comprising:

controlling spot sizes of the two or more particle beams independently on the sample.

34. The method for sample inspection of claim 32, further comprising:

controlling particle energies of the two or more particle beams independently on the sample.

35. The method for sample inspection of claim 32, further comprising:

controlling particle energy densities of the two or more particle beams independently on the sample.

36. The method for sample inspection of claim 32, further comprising:

controlling landing energies of the two or more particle beams independently on the sample.

37. The method for sample inspection of claim 32, wherein an inspection dataset of the one or more inspection datasets includes at least one of data associated with the physical layout of a sample surface, imaging data associated with the second portion of the sample, data associated with material properties of one or more layers of material on a sample, or data indicative of one or more physical defects identified on the sample.

38. A multi-beam inspection system, comprising:

one or more particle beam sources configured to generate two or more particle beams;

a set of particle control elements configured to direct the two or more particle beams to independently selectable positions on a sample through a common focusing element, wherein the set of particle control elements are further configured to direct a first particle beam of the two or more particle beams to a first portion of the sample to emulate at least one of a voltage source or a current source, wherein the set of particle control elements are configured to concurrently scan a second particle beam of the two or more particle beams across a second portion of the sample different than the first portion, wherein at least one structure in the second portion of the sample is electrically connected to the first portion of the sample;

one or more detectors positioned to receive particles emanating from the sample in response to the two or more particle beams; and

a controller communicatively coupled to the one or more detectors, the controller including one or more processors, the one or more processors configured to execute program instructions configured to cause the one or more processors to;

generate one or more inspection datasets associated with the particles received by the one or more detectors, wherein an inspection dataset of the one or more inspection datasets associated with the second particle beam includes imaging data of the second portion of the sample influenced by the at least one of the voltage source or the current source emulated by the first particle beam.