Electron optical systems and detector components

Abstract

This invention relates to a detector assembly, including a detector, an aperture, and an adjustment mechanism. The detector is used to detect a signal electron beam, and the aperture is located on the side of the detector that receives the signal electron beam. The aperture has a central through-hole, and the adjustment mechanism can adjust the area of ​​the through-hole and / or the distance between the aperture and the detector. Furthermore, this invention also discloses an electron optics system, including an electron beam source, a beam splitter, and a detector assembly. The electron beam source emits a main electron beam along the main optical axis onto the sample, generating a signal electron beam on the sample surface. The beam splitter is coaxially arranged with the main optical axis and located between the electron beam source and the sample, used to deflect the signal electron beam. By adjusting the area of ​​the aperture's through-hole and the distance between the aperture and the detector, signal electron beam detection at different diffusion angles can be achieved, meeting the precise detection requirements for different aspect ratios and suitable for characterizing samples with complex morphologies.

Claims

1. A detector assembly for an electro-optical system, comprising: Detector, used to detect signal electron beams; An aperture is located on the side of the detector that receives the signal electron beam, and a through hole is provided in its center; an adjustment mechanism is provided, which can adjust the area of ​​the through hole and / or adjust the distance between the aperture and the detector.

2. The detector assembly as claimed in claim 1, wherein, The central axis of the detector is coaxial with the central axis of the aperture.

3. The detector assembly as claimed in claim 1, wherein, The aperture includes multiple radially movable baffles, and the adjustment mechanism can drive the baffles to move radially to adjust the area of ​​the through hole.

4. The detector assembly as claimed in claim 1, wherein, The adjustment mechanism includes a movable component that is movable along the central axis of the aperture, the movable component being capable of adjusting the distance between the aperture and the detector.

5. The detector assembly as claimed in claim 1, wherein, The adjustment mechanism includes a linear motor, the drive end of which is connected to the aperture to drive the aperture away from or towards the detector.

6. An electro-optical system, comprising: An electron beam source emits a main electron beam along the main optical axis from the sample and generates a signal electron beam on the sample surface. A beam splitter, coaxially arranged with the main optical axis and located between the electron beam source and the sample, the beam splitter being used to deflect the signal electron beam; and a detector assembly as described in any one of claims 1 to 5, the detector assembly being used to detect the deflected signal electron beam.

7. The electro-optical system as claimed in claim 6, wherein, The deflected signal electron beam has a secondary optical axis, and the central axis of the aperture is coaxial with the secondary optical axis.

8. The electro-optical system as described in claim 6, further comprising: The objective lens is located between the beam splitter and the sample.

9. The electro-optical system as claimed in claim 6, wherein, The beam splitter includes a Wien filter.

10. The electro-optical system as claimed in claim 6, wherein, The detector assembly is configured to adjust the aperture area of ​​the aperture according to the aspect ratio of the structure being measured, or to adjust the distance between the aperture and the detector.

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