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CN-121983501-A - Charged particle beam deflection device

CN121983501ACN 121983501 ACN121983501 ACN 121983501ACN-121983501-A

Abstract

The invention relates to a charged particle beam deflection device which comprises a first electrode and a second electrode, wherein a first through hole is formed in the first electrode, and a second through hole is formed in the second electrode. The central axis of the first through hole is a first axis, the central axis of the second through hole is a second axis, and the first axis and the second axis are positioned on the same plane and form a certain included angle. The first electrode and the second electrode are arranged at intervals, and the area between the first electrode and the second electrode forms a deflection area. By applying different voltages to the first electrode and the second electrode, respectively, a non-axisymmetric electric field can be formed in the deflection region, thereby regulating the deflection direction of the charged particle beam passing through the deflection region. According to the invention, through the electrode structure with innovative design and the non-axisymmetric electric field constructed by the electrode structure, the integrated regulation and control of the deflection and focusing of the particle beam are realized, the noise of neutral particles is obviously restrained, the signal to noise ratio is greatly improved, and the adhesion pollution of the neutral particles on the surface of a downstream device is effectively reduced, so that the maintenance period of equipment is obviously prolonged.

Inventors

  • CHENG YUPENG

Assignees

  • 微谱科技(湖州)有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (10)

  1. 1. A charged particle beam deflection device is characterized by comprising a first electrode (101) and a second electrode (104) which are arranged at intervals, wherein a first through hole (102) is formed in the first electrode (101), a second through hole (105) is formed in the second electrode (104), the central axis of the first through hole (102) is a first axis (103), the central axis of the second through hole (105) is a second axis (106), and the first axis (103) and the second axis (106) are coplanar and intersected to form an included angle; the projection of the first through hole (102) on the second electrode (104) is partially overlapped with and not completely overlapped with the second through hole (105), and the projection of the second through hole (105) on the first electrode (101) is partially overlapped with and not completely overlapped with the first through hole (102); The first electrode (101) and the second electrode (104) are arranged at intervals, a deflection area is formed in the area between the first electrode (101) and the second electrode (104), different voltages are respectively applied to the first electrode (101) and the second electrode (104), a non-axisymmetric electric field is formed in the deflection area to regulate and control the deflection direction of the charged particle beam passing through the deflection area, and the deflection angle and the deflection direction of the charged particle beam are jointly controlled by an included angle (107) between a first axis and a second axis and voltages applied to the two electrodes.
  2. 2. Charged particle beam deflection device according to claim 1, characterized in that the angle (107) between the first axis and the second axis has a value in the range of 5 ° to 85 °.
  3. 3. Charged particle beam deflection device according to claim 1, characterized in that the device further comprises a third electrode (111), wherein a third through hole (108) is arranged on the third electrode (111), the central axis of the third through hole (108) is a third axis (109), the first axis (103), the second axis (106) and the third axis (109) are positioned on the same plane, the second axis (106) is intersected with the first axis (103) and the third axis (109) respectively, and the first axis (103) and the third axis (109) are parallel and non-collinear; The projection of the first through hole (102) on the second electrode (104) is partially overlapped with and is not completely overlapped with the second through hole (105), the projection of the first through hole (102) on the third electrode (111) is not overlapped with the third through hole (108), the projection of the second through hole (105) on the first electrode (101) is partially overlapped with and is not completely overlapped with the first through hole (102), the projection of the second through hole (105) on the third electrode (111) is partially overlapped with and is not completely overlapped with the third through hole (108), the projection of the third through hole (108) on the first electrode (101) is not overlapped with the first through hole (102), and the projection of the third through hole (108) on the second electrode (104) is partially overlapped with and is not completely overlapped with the second through hole (105); The first electrode (101), the second electrode (104) and the third electrode (111) are arranged at intervals to form a first deflection area (203) and a second deflection area (204) respectively, and different voltages are respectively applied to the first electrode (101), the second electrode (104) and the third electrode (111) to form non-axisymmetric electric fields in the first deflection area (203) and the second deflection area (204) respectively so as to regulate and control the deflection directions of charged particle beams passing through the first deflection area (203) and the second deflection area (204) and realize multistage deflection.
  4. 4. A charged particle beam deflection device according to claim 3, wherein the range of angles (107) between the first and second axes and the range of angles (110) between the second and third axes are each 5 ° -85 °.
  5. 5. A charged-particle beam deflection apparatus according to claim 1 or 3, wherein each electrode is any one of a plate electrode, a plate electrode or a bulk electrode.
  6. 6. A charged particle beam deflection apparatus according to claim 1 or claim 3 wherein each electrode is of uniform thickness.
  7. 7. A charged particle beam deflection apparatus according to claim 3, wherein at least one of said first electrode (101), said second electrode (104) and said third electrode (111) has a non-uniform thickness structure, adjacent surfaces of adjacent electrodes are parallel to each other with a predetermined interval, each electrode has a through hole, and each through hole together forms a passage for passing charged particles.
  8. 8. A charged particle beam deflection apparatus according to claim 1 or 3, wherein the charged particle beam deflection apparatus comprises an array structure of at least two symmetrically placed deflection units, each comprising a first electrode and a second electrode, or comprising a first electrode, a second electrode and a third electrode.
  9. 9. A charged-particle beam deflection apparatus according to claim 1 or claim 3 wherein the material of each electrode is metal or non-metal with a conductive coating.
  10. 10. A charged-particle beam deflection apparatus according to claim 1 or 3, wherein the through holes provided in the respective electrodes are in the shape of any one of a circle, an ellipse, and a polygon.

Description

Charged particle beam deflection device Technical Field The invention relates to the technical field of charged particle beam control, in particular to a charged particle beam deflection device which is suitable for a mass spectrometer and can accurately control and deflect the flight path of charged particle beams such as electrons, ions and the like. Background Deflection of a charged particle beam is the core function of achieving its directional transport, scanning, imaging, and beam splitting. Currently, the main technologies for realizing deflection are mainly divided into two main categories, namely magnetic deflection and electrostatic deflection. The electrostatic deflection device is widely applied to various scenes with strict requirements on real-time performance, power consumption and space by virtue of the advantages of high response speed, no need of exciting power, no influence of residual magnetic field effect and the like. The most common electrostatic deflector is a parallel plate electrode structure consisting of two mutually parallel, mutually insulated metal plates between which a uniform electrostatic field is generated when a voltage is applied between the plates. When the vertically incident charged particle beam passes through the region, the charged particle beam is subjected to electrostatic force perpendicular to the initial velocity direction, and the trajectory of the charged particle beam is parabolic and similar to a flat projectile motion. Despite its simple structure, the parallel plate deflector has a number of inherent insurmountable drawbacks, namely, a single function and a fixed deflection direction. The electric field generated by the deflector is approximately uniform among the polar plates, the direction is fixed, the deflection direction is basically perpendicular to the plane of the electrode, and if the deflection in different directions is realized, the particle beam needs to be guided to another group of parallel plate deflectors with different orientations, or the whole deflector is physically rotated, so that the flexibility is very poor. Second, only deflection can be achieved, lacking focusing capability. The uniform electric field can only generate an overall translational deflection effect on the particle beam, and cannot play any focusing or defocusing role on the beam. However, in practical systems, the charged particle beam is naturally diverged by space charge effects, and thus electrostatic or magnetic focusing lenses must be introduced in the transmission optical path independently and in series. This separate design of the deflection unit and the focusing unit directly results in a complicated system structure and an increase in length. Third, neutral noise cannot be handled. In many ion beam applications such as ion implantation and mass spectrometry, neutral particles generated by charge exchange are often mixed in the beam. The uniform electric field of the parallel plate deflector does not act on neutral particles at all, and the neutral particles can act as noise to directly reach a target, so that background interference, sample pollution or signal distortion are caused, and the working purity and the precision of equipment are seriously affected. Chinese patent document CN121075897a discloses an ion lens assembly comprising a deflection lens assembly and a return axis lens assembly arranged in sequence. The beam deflection lens assembly is used for deflecting the ion beam towards a first direction, and the beam return lens assembly is used for deflecting the ion beam towards a second direction opposite to the first direction, so that the optical axis of the ion beam is parallel or coincident with the initial optical axis finally. The key improvement point is that the projection outlines of the ion extraction hole and the subsequent collimation hole in the deflection assembly are staggered and non-overlapped in space, through the light path design, charged ions can deflect and return to the axis under the action of electric field force, neutral particles move along a straight line and are blocked physically because the charged ions are not influenced by the electric field, and further, efficient neutral particle separation is realized, and the noise transmission probability is further reduced due to the staggered design of the extraction hole, and the detection signal-to-noise ratio and the dynamic range are improved. Although the ion lens component realizes the physical separation of ion deflection and neutral particles through the combined optical path of the deflection lens and the return axis lens, the ion lens component essentially separates the two functions of deflection and the return axis, and is completed by connecting two independent lens components in series, and the design directly leads to the obvious redundancy and the complex structure of the optical path of the system. Chinese patent document CN120015596a discloses a deflect