MULTI-BEAM SYSTEM FOR HIGH THROUGHPUT EBI

• US 20150155134A1
• Filed: 02/06/2014
• Published: 06/04/2015
• Est. Priority Date: 12/02/2013
• Status: Active Grant

• Current Assignee: ICT Integrated Circuit Testing Gesellschaft Fur Halbleiterpruftechnik GmbH
• Original Assignee: ICT Integrated Circuit Testing Gesellschaft Fur Halbleiterpruftechnik GmbH
• Inventors: FROSIEN, Jrgen, WINKLER, Dieter, COOK, Benjamin John
• Granted Patent: US 9,035,249 B1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01J 2237/0453 multiple apertures
• CPC Class Codes: H01J 2237/0475 decelerating
• CPC Class Codes: H01J 2237/1205 Microlenses
• CPC Class Codes: H01J 2237/21 Focus adjustment
• CPC Class Codes: H01J 2237/2448 Secondary particle detectors
• CPC Class Codes: H01J 2237/24592 Inspection and quality control of devices
• CPC Class Codes: H01J 2237/2806 Secondary charged particle
• CPC Class Codes: H01J 2237/2817 Pattern inspection
• CPC Class Codes: H01J 37/05 Electron or ion-optical arrangements for separating electrons or ions according to their energy or massparticle separator tubes H01J49/00
• CPC Class Codes: H01J 37/09 Diaphragms; Shields associated with electron or ion-optical arrangements; Compensation of disturbing fields
• CPC Class Codes: H01J 37/1472 Deflecting along given lines
• CPC Class Codes: H01J 37/1474 Scanning means
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

A scanning charged particle beam device configured to image a specimen is described. The scanning charged particle beam device includes a source of charged particles, a condenser lens for influencing the charged particles, an aperture plate having at least two aperture openings to generate at least two primary beamlets of charged particles, at least two deflectors, wherein the at least two deflectors are multi-pole deflectors, a multi-pole deflector with an order of poles of 8 or higher, an objective lens, wherein the objective lens is a retarding field compound lens, a beam separator configured to separate the at least two primary beamlets from at least two signal beamlets, a beam bender, or a deflector or a mirror configured to deflect the at least two signal beamlets, wherein the beam bender is a hemispherical beam bender or beam bender having at least two curved electrodes, and at least two detector elements.

Claims

1. A scanning charged particle beam device configured to image a specimen, comprising:

a source of charged particles,

a condenser lens for influencing the charged particles;

an aperture plate having at least two aperture openings to generate at least two primary beamlets of charged particles,

at least two deflectors configured to individually deflect the at least two primary beamlets of charged particles so that each primary beamlet appears to come from a different source, wherein the at least two deflectors are multi-pole deflectors with an order of poles of 8 or higher;

a multi-pole deflector with an order of poles of 8 or higher;

an objective lens configured to focus the at least two primary beamlets onto the specimen, wherein the objective lens is a retarding field compound lens;

a beam separator configured to separate the at least two primary beamlets from at least two signal beamlets;

a beam bender, a deflector or mirror configured to deflect the at least two signal beamlets, wherein the beam bender is selected from the group consisting of;

a hemispherical beam bender and a beam bender having at least two curved electrodes; and

at least two detector elements configured to individually measure the at least two signal beamlets.

2. The device according to claim 1, wherein the multi-pole deflector is included in a scanning deflector system for scanning the at least two primary beams of charged particles over the specimen, wherein the scanning deflector system includes at least one scanning deflector, and wherein the at least one scanning deflector is the multi-pole deflector with an order of poles of 8 or higher.

3. The device according to claim 1, wherein the smallest distance of any two aperture openings of the at least two aperture openings is 70 μ

m or higher.

4. The device according to claim 1, wherein the smallest distance of any two primary beamlets of the at least two primary beamlets on impingement of the specimen is 10 μ

m or higher.

5. The device according to claim 4, wherein the smallest distance of any two primary beamlets of the at least two primary beamlets on impingement of the specimen is 40 μ

m or higher.

6. The device according to claim 1, further comprising:

a second condenser lens.

7. The device according to claim 1, wherein the objective lens focuses the source, a cross-over or a virtual source onto the specimen.

8. The device according to claim 2, wherein the scanning deflector system is a 2-stage scanning deflector system including the at least one scanning deflector and a further scanning deflector.

9. The device according to claim 8, wherein the scanning deflector system is an electrostatic scanning deflector system.

10. The device according to claim 1, wherein the at least two deflectors are provided in a MEMS.

11. The device according to claim 1, wherein said aperture openings in said aperture plate are arranged along at least one ring.

12. The device according to claim 11, wherein the aperture openings are further arranged on essentially equidistant lines.

13. The device according to claim 1, wherein said apertures in said aperture plate are arranged in a matrix of at least 3 rows.

14. The device according to claim 13, wherein said apertures in said aperture plate are arranged in a matrix of at least 3 rows and at least 3 columns.

15. The device according to claim 1, wherein the at least two detector elements are arranged to measure the at least two signal beamlets at a beam propagation direction having an angle with respect to the primary beamlets of at least 30°

.

16. The device according to claim 1, wherein the column comprises a beam selector for selecting the number of charged particle beams used to examine the specimen.

17. The device according to claim 1, wherein the number of aperture openings is 5 or more.

18. An arrayed scanning charged particle beam device, comprising:

at least two scanning charged particle beam devices configured to image a specimen, each scanning charged particle beam device comprises;

a source of charged particles,

a condenser lens for influencing the charged particles;

an aperture plate having at least two aperture openings to generate at least two primary beamlets of charged particles,

at least two deflectors configured to individually deflect the at least two primary beamlets of charged particles so that each primary beamlet appears to come from a different source, wherein the at least two deflectors are multi-pole deflectors with an order of poles of 8 or higher;

a multi-pole deflector with an order of poles of 8 or higher;

an objective lens configured to focus the at least two primary beamlets onto the specimen, wherein the objective lens is a retarding field compound lens;

a beam separator configured to separate the at least two primary beamlets from at least two signal beamlets;

a beam bender, a deflector or mirror configured to deflect the at least two signal beamlets, wherein the beam bender is selected from the group consisting of;

a hemispherical beam bender and a beam bender having at least two curved electrodes; and

at least two detector elements configured to individually measure the at least two signal beamlets.

19. A arrayed scanning charged particle beam device configured to image a specimen, comprising:

at least five scanning charged particle beam devices configured to image a specimen, each scanning charged particle beam device comprises;

a source of charged particles,

a condenser lens for influencing the charged particles;

an aperture plate having at least five aperture openings to generate at least five primary beamlets of charged particles, wherein the smallest distance of any two aperture openings of the at least two aperture openings is 70 μ

m or higher,

at least five deflectors configured to individually deflect the at least five primary beamlets of charged particles so that each primary beamlet appears to come from a different source, wherein the at least two deflectors are multi-pole deflectors with an order of poles of 8 or higher;

a scanning deflector system for scanning the at least five primary beams of charged particles over the specimen, wherein the scanning deflector system includes at least one scanning deflector, and wherein the at least one scanning deflector is a multi-pole deflector with an order of poles of 8 or higher

an objective lens configured to focus the at least five primary beamlets onto the specimen, wherein the objective lens is a retarding field compound lens;

a beam separator configured to separate the at least five primary beamlets from at least five signal beamlets;

a beam bender, a deflector or mirror configured to deflect the at least five signal beamlets, wherein the beam bender is selected from the group consisting of;

a hemispherical beam bender and a beam bender having at least two curved electrodes; and

at least five detector elements configured to individually measure the at least five signal beamlets.

20. The device according to claim 19, wherein the scanning deflector system is a 2-stage scanning deflector system including the at least one scanning deflector and a further scanning deflector.