Particle energy band-pass device, electron energy analyzer and photoelectron spectrometer

Abstract

The utility model discloses a charged particle energy band-pass device, an electron energy analyzer and a photoelectron spectrometer, an incident channel and an emergent channel are arranged on a reflection cavity, a particle transmitter is arranged at the incident channel and / or the emergent channel, a particle reflector is arranged in the reflection cavity, and the charged particle energy band-pass device is obtained by adjusting the electric field distribution of the reflector and the transmitter. And a particle band-pass function is realized. The particle energy band-pass device designed by the utility model can also be compatible with various lens systems and energy analyzers, is flexible in conversion, and is suitable for various particle energy selection scenes. The device is simple and compact in structure, and is particularly suitable for application scenes of small particle selection and analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of charged particle optical equipment, and in particular to a particle energy bandpass device, an electron energy analyzer and a photoelectron spectrometer. Background Art

[0002] The particle energy bandpass device is to select particles with a certain energy range from a particle beam with multiple energies. This selection can set both the upper and lower limits of the selection, and is also called a particle energy analyzer.

[0003] In the prior art, particle energy analyzers can be divided into time-of-flight method, electrostatic field reflection method, electrostatic field deflection method, magnetic field deflection method, etc. The present invention relates to a device for energy bandpass using the electrostatic field reflection method, which is as follows:

[0004] Figure 1 The flat plate reflection structure shown in a is a flat plate reflection structure, which includes the main structures such as the entrance slit, exit slit, and reflection electrostatic field. The bottom of the plate is positively charged, and the top is negatively charged. Through the incident particles and the incident angle, the distance between the slits, the electric field, etc., the energy screening of the incident electrons can be formed to achieve energy bandpass or energy analysis. However, this type of flat plate reflection structure has small slits at the entrance and exit, and the particle flux is low.

[0005] Moreover, the incident angle is oblique, which greatly limits the layout of the particle lens and the layout of the sample.

[0006] Figure 1 The typical structure of a flat or spherical reflective net is shown in b. The concentric dotted lines in the figure are concentric spherical curves. The voltage difference between the first layer and the second layer can reflect low-energy electrons, so that they cannot enter the detector. This structure is widely used in the front side of various detectors to filter stray electrons. However, this energy screening only performs low-energy cutoff and cannot achieve bandpass.

[0007] Figure 1 The energy filter shown in c is an ellipsoid reflection combined with spherical transmission. This structure achieves energy screening by placing the sample and the slit at the two foci of the ellipsoid, combining spherical transmission and ellipsoid reflection. However, the energy filter has strict requirements on the layout of the sample and the slit, which leads to great restrictions on the incident photons, electrons and other excitation sources; it is impossible to add structures such as lenses between the sample and the bandpass filter to perform complex and multifunctional measurements; the overall components are numerous, the structure is complex, and the universality is poor. Summary of the invention

[0008] In order to solve the deficiencies in the prior art, the present application proposes a particle energy bandpass device, an electron energy analyzer, and a photoelectron spectrometer, with the aim of providing a particle energy bandpass device with a simpler structure that can realize the bandpass function; it can also be combined with a lens system and has good application prospects.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A particle energy bandpass device, comprising:

[0011] At least one reflecting cavity, wherein the reflecting cavity is provided with at least two channels, and both channels are connected to the reflecting cavity;

[0012] At least one reflector is arranged in the reflection cavity; two channels opposite to the reflector are used as an incident channel and an exit channel; at least one channel is equipped with a transmitter;

[0013] The reflection cavity, the transmitter and the reflector are all connected to a voltage source, and the voltages of the reflection cavity, the transmitter and the reflector are set respectively.

[0014] Furthermore, the interior of the reflection cavity is a spherical space, and a plurality of channels are arranged along the radial direction of the reflection cavity.

[0015] Furthermore, the reflector is rotatably installed in the reflection cavity, and the incident channel and the exit channel are switched by rotating the reflector.

[0016] Furthermore, the multiple reflection cavities are interconnected and arranged along the same axis; and the reflectors are rotatably installed in the reflection cavities.

[0017] Furthermore, an electron receiving plate is provided on the side of the reflection cavity opposite to the incident channel.

[0018] An electron energy analyzer, wherein at least one lens system is arranged at the entrance side and / or exit side of the particle energy bandpass device, and a detector is arranged at the exit side of the particle energy bandpass device;

[0019] The lens system on the incident port side is located between the incident port of the reflection cavity and the sample, and the lens system on the exit port side is located between the exit port of the reflection cavity and the detector.

[0020] A photoelectron spectrometer is provided, based on the above-mentioned electron energy analyzer, with a light source configured to excite photoelectrons from a sample.

[0021] Furthermore, the light source is arranged on the incident port side of the reflection cavity and is arranged toward the sample.

[0022] Furthermore, when the transmissor and reflector in the coaxial direction both adopt a high-transmittance reflective structure, the light source is arranged opposite to the sample, and the light source is incident through the reflective cavity and the transmissor, and the reflector is perpendicular to the sample surface.

[0023] Furthermore, the light source is replaced by electron beam incidence.

[0024] Beneficial effects of the present invention:

[0025] (1) The particle energy bandpass device designed by the present invention has the function of energy bandpass, and can realize the measurement of electron beam energy spectrum by scanning the voltage of each component.

[0026] (2) The energy bandpass structure of the present invention is compatible with various lens systems currently used in the field of energy analyzers, including electrostatic lenses, magnetic lenses; active lenses or passive lenses; axisymmetric types, non-axis-symmetrical types, etc. It has strong compatibility and can be applied to various application scenarios.

[0027] (3) The energy bandpass structure of the present invention does not require a slit structure and can greatly improve the flux and detection efficiency.

[0028] (4) The overall structure of the device designed by the present invention is simple and the cost is low.

[0029] (5) The overall structure of the device designed by the present invention is simple, and the energy bandpass, energy analyzer, and energy spectrum analyzer can be made compact and small, which is particularly suitable for some miniaturized application scenarios.

[0030] (6) It can be matched with a variety of commonly used 0-dimensional, 1-dimensional, 2-dimensional and other detectors, and has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 In the figure, a, b, and c are schematic diagrams of the structures of three existing particle energy analyzers;

[0032] Figure 2 , 3 All of them are schematic diagrams of the structure of a particle energy bandpass device of the present invention;

[0033] Figure 4 , 5 All of them are structural schematic diagrams of an electronic energy analyzer of the present invention.

[0034] Figure 6 , 7 All of them are photoelectron spectrometers of the present invention.

[0035] In the figure, 1, entrance transmission mesh, 2, reflection mesh, 3, exit transmission mesh, 4, reflection cavity, 5, sample, 6a-6f are all electron beams, 7, electron receiving plate, 10, first lens system, 11, particle detector, 12, second lens system, 13, third lens system, 21, light source. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Example 1

[0038] Combined with Figure 2 The present invention shows a particle energy bandpass device, including a reflection cavity 4, on which an incident channel and an exit channel are provided, both of which are connected to the reflection cavity 4; the angle between the incident channel and the exit channel is 90°; an entrance transmission net 1 is provided at the entrance of the incident channel, and a reflection net 2 is provided in the reflection cavity 4, and the reflection net 2 is arranged obliquely, so that its reflection surface can face the incident channel and the exit channel respectively; an exit transmission net 3 is provided at the exit channel. The entrance transmission net 1, the reflection net 2 and the exit transmission net 3 are connected to power supplies respectively, and different voltages can be set, thereby setting the energy range of the energy bandpass device cutoff.

[0039] The above-mentioned particle energy bandpass device is described by taking electrons as an example. The sample 5 is located at the entrance of the incident channel, and the grounded sample 5 emits an electron beam 6a, which reaches the entrance transmission net 1. The entrance transmission net 1 is loaded with a certain negative voltage. Electrons with lower energy will be reflected to form an electron beam 6b. Electrons with energy higher than the entrance transmission net 1 will pass through the entrance transmission net 1 to form an electron beam 6c. The electron beam 6c drifts in the electrostatic field formed by the entrance transmission net 1, the reflection net 2 and the reflection cavity 4. The electron beam with higher energy will directly pass through the reflection net 2 to form an electron beam 6d, which will be absorbed by the cavity wall of the reflection cavity 4. The electrons with lower energy are reflected by the electric field distribution formed by the reflection net 2 and the reflection cavity 4 to form a final electron beam 6e. The final electron beam 6e will pass through the exit transmission net 3 to form a final electron beam 6f. Compared with electron beam 6a, electron beam 6f has cutoffs on the upper and lower limits of energy; the energy range cutoff of the energy bandpass device is determined by the voltages loaded on the entrance transmission mesh 1, the reflection mesh 2, the exit transmission mesh 3, and the reflection cavity 4, as well as their structural functions.

[0040] In this embodiment, the angle between the incident channel and one exit channel is not limited to 90°, and can be set according to the situation, such as 60°, 120°, or other angles.

[0041] In this embodiment, the number of transmission nets in the incident channel and / or the exit channel can be increased or decreased as needed, such as one or more combined layouts.

[0042] On the basis of the above design, an improved particle energy bandpass device is also proposed. In this design, the interior of the reflection cavity 4 is a spherical space, and the internal electrostatic field can be more uniform and controllable; 4 channels or more channels are evenly arranged around the reflection cavity 4, and all are connected to the reflection cavity 4. On the basis of this structural design, the bottom of the reflection cavity 4 is the incident channel, and the right side is the exit channel; the entrance transmission net 1 and the exit transmission net 3 are respectively arranged in the incident channel and the exit channel, and the reflection net 2 is arranged in the reflection cavity 4. If the reflection net 2 can be rotatably installed in the reflection cavity 4, the exit of the electron beam can be changed. For example, after rotating 90°, the electron beam can be emitted from the left exit channel, and the entrance of the electron beam can also be changed by the same token. In this design, an electron receiving plate 7 is arranged at the channel opposite to the incident channel to completely absorb the transmitted electron beam 6d and reduce further scattering.

[0043] Based on the above design, an improved particle energy bandpass device is also proposed, such as Figure 3 In this design, the device includes a plurality of reflection cavities 4, which are arranged coaxially and adjacent reflection cavities 4 are connected coaxially through channels; one or more exit channels are arranged in the circumference of the reflection cavity 4; a reflection net 2 can be arranged in each layer of the reflection cavity 4, and the channel on the axis of the end reflection cavity 4 is used as the incident channel. The electron beam entering from the incident channel can be reflected by the reflection net 2 layer by layer and emitted from the exit channel of the corresponding layer, and the electron beam passing through the reflection net 2 can enter the next layer and be screened again. In this design, the reflection net 2 in each layer can rotate, so it can face different exit channels.

[0044] In the above design, a solid metal plate can be used to replace the reflective mesh 2. In this case, electrons with higher energy can directly bombard the reflective plate and be absorbed by the reflective plate. In terms of structure, the reflective mesh 2 or the reflective plate can be a plane or a surface of other shapes.

[0045] Embodiment 2 The present invention also designs an electron energy analyzer, which further combines the particle energy bandpass device designed in Embodiment 1 with electron optical related components such as a particle lens system and a detector system to form a particle energy analyzer with extensive functions, such as Figure 4 As shown, a first lens system 10 is added between the incident port and the sample 5, and a particle detector 11 is added at the exit port. The first lens system 10 includes a series of lens components, such as the lens pole L0, the lens pole L1, the lens pole L2, etc., which are coaxially arranged in parallel. The detector 11 can be an electron multiplier detector, a DLD detector, an MCP-fluorescent screen structure detector, and other types.

[0046] The lens system 10 transmits the electron beam emitted from the sample 5 to the entrance transmission net 1. The transmission of the electron beam in the first lens system 10 can be different characteristics such as angle resolution, spatial resolution, high flux, etc. according to the requirements, which are controlled by the lens system. After the incident electron beam 6a is screened by the bandpass device, an outgoing electron beam 6e is formed. The outgoing electron beam 6e is finally measured by the detector 11 to obtain the intensity or image information of the energy segment screened by the energy bandpass.

[0047] At the same time, this application also proposes an improved electronic energy analyzer design, such as Figure 5 As shown, a second lens system 12 is added between the transmission net 1 and the reflection cavity 4. The second lens system 12 can make more detailed control of the flight behavior of the transmission electron beam 6c, such as focusing, imaging mode, etc. Then, the energy is screened and reflected by the reflection net 2 in a specific way.

[0048] More preferably, a third lens system 13 may be added between the reflection cavity 4 and the detector 11 to finely control the flight behavior of the outgoing electron beam 6e, for example, to bombard the detector 11 in different forms such as focusing, angle resolution, spatial resolution, and high flux, and finally be measured by the detector 11. In this embodiment, each flight process of the electron beam can be fully controlled to meet the transformation of various applications.

[0049] More preferably, it is also suitable for modifying the particle energy bandpass device with multiple layers of reflection cavity 4 and outlet channels in Example 1, and a detector 11 can be set at the outlet side of each layer, so as to obtain the intensity or image information of the energy segment screened out by each layer of energy bandpass. In addition, by rotating the direction of the reflection net 2 inside the reflection cavity 4, the detectors 11 at the output ports of different layers can be installed in different positions, which is convenient for the layout and installation of the entire system.

[0050] This embodiment is an electron energy analyzer with a relatively complete structure, which can be used in various application scenarios such as electron spectrometers, such as XPS, ARPES, k-ARPES, PEEM, AES, etc.

[0051] Example 3

[0052] Based on any one of the electron energy analyzers designed in the above embodiment 2, the present application also proposes a photoelectron spectrometer, such as Figure 6 A light source 21 is added. The light source 21 can be a laser light source, a plasma light source, a synchrotron radiation light source, or other light sources that can excite photoelectrons from the sample 5. The excited photoelectrons 6a are detected by the electron energy spectrum analyzer of the present invention to obtain the electronic structure of the material; it is a brand-new photoelectron energy spectrometer structure.

[0053] More preferably, if Figure 7 When the transmission net 1 and the reflection net 2 in the coaxial direction both adopt a high-transmittance reflection structure, the light source can be introduced from the top of the figure, and the light source incident can be perpendicular to the sample surface. Vertical incidence is very important for measurements such as spot sensitivity, time sensitivity, and matrix element effect sensitivity.

[0054] More preferably, when the light source 21 is changed to electron beam incident, the excited electron beam 6a is Auger electron, and the Auger electron measurement can be performed.

[0055] The above embodiments are only used to illustrate the design ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A particle energy bandpass device, characterized in that: include: at least one reflecting cavity (4), wherein the reflecting cavity (4) is provided with at least two channels, and both channels are connected to the reflecting cavity (4); At least one reflector is arranged in the reflection cavity (4); two channels opposite to the reflector serve as an incident channel and an exit channel; At least one channel is equipped with a transilluminator; The reflection cavity (4), the transmitter and the reflector are all connected to a power supply, and the voltages of the reflection cavity (4), the transmitter and the reflector are set respectively.

2. A particle energy bandpass device according to claim 1, characterized in that: The interior of the reflection cavity (4) is a spherical space, and a plurality of channels are arranged along the radial direction of the reflection cavity (4).

3. A particle energy bandpass device according to claim 1, characterized in that: The reflector is rotatably mounted in the reflection cavity (4), and the incident channel and the exit channel are switched by rotating the reflector.

4. A particle energy bandpass device according to claim 1, characterized in that: The plurality of reflection cavities (4) are interconnected, and the reflection cavities (4) are arranged along the same axis; a reflector is rotatably mounted in the reflection cavity (4).

5. A particle energy bandpass device according to claim 1, characterized in that: An electron receiving plate (7) is provided on the side of the reflection cavity (4) opposite to the incident channel.

6. An electron energy analyzer, characterized in that: At least one lens system is arranged at the entrance side and / or exit side of the particle energy bandpass device as claimed in any one of claims 1 to 5, and a detector (11) is arranged at the exit side of the particle energy bandpass device; The lens system on the incident port side is located between the incident port of the reflection cavity (4) and the sample (5), and the lens system on the exit port side is located between the exit port of the reflection cavity (4) and the detector (11).

7. A photoelectron spectrometer, characterized in that: An electron energy analyzer as claimed in claim 6 is provided with a light source (21), the light source (21) exciting photoelectrons from a sample (5).

8. A photoelectron spectrometer according to claim 7, characterized in that: The light source (21) is arranged on the incident side of the reflection cavity (4) and is arranged toward the sample (5).

9. A photoelectron spectrometer according to claim 7, characterized in that: When the transmissor and reflector in the coaxial direction both adopt a high-transmittance reflective structure, the light source (21) is arranged opposite to the sample (5), and the light source is incident through the reflective cavity (4) and the transmissor, reflector and sample (5) surface perpendicularly.

10. A photoelectron spectrometer according to claim 7, characterized in that: The light source (21) is replaced by electron beam incidence.

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