JP-2026514268-A - Charged particle optics

Abstract

An electro-optical projection device for projecting multiple charged particle beams toward a sample, the device comprising a stack of plates including beam guide elements configured to project multiple charged particle beams toward a sample position on the sample, wherein at least one plate of the stack has a planar optical member configured to direct a stimulating light toward the sample position, aligning the stimulating light with the multiple charged particle beams, and preferably aligning it with the paths of the multiple charged particle beams toward the sample position, and preferably, a plurality of apertures for each path of the multiple electro-optical beams are defined within at least one plate including the optical member. [Selection Diagram] Figure 13

Inventors

• ヴァン エンゲレン，ヨルン，ポール
• シャーヒン，エズギ
• アクブルト，ドゥイギュ
• ペレマンズ，ヘンリカス，ペトラス，マリア
• ウィーラント，マルコ，ジャン－ジャコ
• スロット，エルウィン
• カイパー，ヴィンセント，シルヴェスター

Assignees

• エーエスエムエル ネザーランズ ビー．ブイ．

Dates

Publication Date

20260508

Application Date

20231004

Priority Date

20221027

Claims (15)

1. An electron-optical projection device for projecting multiple charged particle beams toward a sample, The laminate comprises plates including beam guidance elements configured to project the plurality of charged particle beams toward the sample position on the sample, At least one plate of the laminate has a planar optical member configured to direct stimulating light towards the sample position and to align the stimulating light with the plurality of charged particle beams, An electron-optical projection device wherein at least one plate has multiple apertures for each path of multiple charged particle beams.
2. The planar optical member is configured to direct the stimulation light so that it is incident near, or at least partially overlapping with, a portion of the individual electron beams at the sample position. The device according to claim 1, wherein the region illuminated by the stimulating light has a larger cross-sectional area than the cross-section of the individual electron beams at the sample position.
3. The device according to claim 1 or 2, wherein the planar optical member includes a transparent plate.
4. The device according to claim 3, wherein the thickness of the transparent plate exceeds twice the wavelength of the stimulating light, and preferably is in the range of 5 μm to 50 μm.
5. The transparent plate has an output coupling mechanism configured to direct the stimulating light towards the sample, preferably the output coupling mechanism is a. Mirror or lens surface, The device according to claim 3 or 4, comprising at least one of b. a diffraction grating, and c. a region in which the refractive index of the transparent plate changes.
6. The device according to claim 5, wherein the transparent plate has an output coupling mechanism for each of the plurality of charged particle beams.
7. The device according to claim 1 or 2, wherein the planar optical member includes, for example, an optical system comprising a waveguide, a power divider, and an output coupler.
8. The optical system comprises a plurality of beam paths and a plurality of power dividers for dividing the stimulating light between the beam paths, preferably, the individual power dividers on the beam paths are configured to divide the beam paths and direct the beam paths to individual apertures of the plurality of apertures, according to claim 7.
9. The device according to claim 7 or 8, wherein the optical system includes a plurality of output couplers configured to direct stimulating light towards the sample.
10. The device according to any one of claims 1 to 9, wherein another plate of the laminate is located within the laminate between the planar optical member and the sample position.
11. The device according to any one of claims 1 to 10, wherein the plate includes a detector array.
12. The electrostatic electrode is either a monolithic plate having a single electrical contact, or The device according to claim 11, wherein the electrostatic electrode includes a plurality of electrodes, thereby the plate includes a manipulator array such as a multi-pole array.
13. The system further includes a light source configured to generate the aforementioned stimulating light, The device according to any one of claims 1 to 12, wherein the light source is configured to direct the stimulating light so that it is incident simultaneously with and/or before the incident of the charged particle beam.
14. The device according to claim 13, further comprising an optical conduit configured to couple the stimulating light from the light source to the optical member.
15. The device according to any one of claims 1 to 14, wherein the planar optical member is included in the plate of the laminate that is closest to the sample, and is, for example, attached thereto.

Description

Cross-reference of related applications [0001] This application claims priority to European Patent Application Publication No. 22204243.4, filed on 27 October 2022, and European Patent Application Publication No. 23158846.8, filed on 27 February 2023, both of which are incorporated herein by reference in their entirety. [0002] The embodiments provided herein generally relate to charged particle optics and methods for evaluating samples. [0003] When manufacturing semiconductor integrated circuit (IC) chips, undesirable pattern defects, such as those caused by optical effects or incidental particles, inevitably occur on the substrate (i.e., wafer) or mask during the manufacturing process, thereby reducing yield. Therefore, monitoring the extent of undesirable pattern defects is a critical process in IC chip manufacturing. More generally, inspection and/or measurement of the surface of the substrate or other object/material is a critical process during and/or after manufacturing. [0004] Pattern inspection tools using charged particle beams have been used to inspect objects, for example, to detect pattern defects. These tools typically use electron microscopy techniques, such as scanning electron microscopes (SEMs). In an SEM, a primary electron beam of relatively high-energy electrons is directed to a target in the final deceleration phase so that it is incident on the sample with relatively low incident energy. The electron beam is focused onto the sample as a probe spot. Interaction between the material structure of the probe spot and the incident electrons from the electron beam causes electrons to be emitted from the surface, which are, for example, secondary electrons, backscattered electrons, or Auger electrons, and may also be called signal particles. The generated secondary electrons may be emitted from the material structure of the sample. By scanning the sample surface as a probe spot with the primary electron beam, secondary electrons can be made to be emitted across the entire sample surface. By collecting these emitted secondary electrons from the sample surface, the pattern inspection tool can obtain an image that represents the characteristics of the material structure of the sample surface. The intensity of the electron beam, including backscattered and secondary electrons, may vary based on the characteristics of the internal and external structure of the sample, thereby indicating whether the sample has defects. [0005] When scanning a sample with a primary electron beam, the high beam current can cause charge to accumulate on the sample, which can affect image quality. Material structures may be illuminated with light and/or flooded with electrons to improve defect contrast during defect inspection. For example, to adjust the accumulated charge on a sample, an Advanced Charge Controller (ACC) module can be used to irradiate the sample with a light beam, such as a laser beam, and control the accumulated charge through effects such as photoconductivity, photoelectricity, or thermal effects. In the following description, the term ACC is used as an abbreviation for illumination with a light beam. The term ACC should generally be understood as referring to illumination with a light beam. Irradiating a sample with a light beam can be difficult. For example, the dimensions of a pattern inspection tool may make it difficult to reach the sample with a light beam. [0006] The object of this disclosure is to provide embodiments that enable the simultaneous illumination of a sample with light to provide improved defect contrast during evaluation. [0007] According to a first aspect of the present invention, a plate for an electro-optical device is provided which is configured to project a plurality of charged particle beams toward a sample, the device comprising the plate within a plate lamination, Within the plate, multiple apertures are defined for each of the paths of multiple charged particle beams. The plate includes a planar optical element configured to direct stimulating light towards the sample and align the stimulating light with the paths of multiple charged particle beams heading toward the sample. [0008] According to a second aspect of the present invention, a stimulation module is provided for use in an electro-optical projection device for projecting a plurality of charged particle beams toward a sample, the module being The planar optical member includes a planar optical member configured to direct a stimulating light toward a sample and to align the stimulating light with multiple charged particle beams, wherein multiple apertures are defined within the plate for each path of the multiple charged particle beams, and preferably the planar optical member consists of a plate from, for example, a stack of plates arranged along the paths of the multiple charged particle beams toward the sample. [0009] According to a third aspect of the present invention, an electro-optic projection device is pr