A compact extreme ultraviolet broadband spectrometer

By using a non-periodic Al/Zr multi-layer film spherical mirror and a large-diameter gold transmission grating in an extreme ultraviolet spectrometer, a compact positive incident structure is achieved, which solves the problems of large volume, difficulty in assembly and low efficiency of traditional extreme ultraviolet spectrometers, and improves the intensity and resolution of the spectral signal.

CN119104151BActive Publication Date: 2025-03-07ZHEJIANG TONGYUE OPTICAL TECH CO LTD
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Patent Information

Application Number
CN202411326187.4
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2024-09-23
Publication Date
2025-03-07
Estimated Expiration
2044-09-23

AI Technical Summary

Technical Problem

Traditional extreme ultraviolet spectrometers adopt grazing incident structure to cause large system size, difficult installation and adjustment, low efficiency in the 24-32nm band, and insufficient spectral signal intensity.

Method used

A compact extreme ultraviolet broadband spectrometer is designed, using a non-periodic Al/Zr multi-layer film spherical mirror and a 1000-line/mm large-diameter gold transmission grating to achieve a positive incident structure and improve the intensity and resolution of the spectral signal.

Benefits of technology

High-pass optical efficiency in the 24-32nm band is achieved, which enhances the intensity of the spectral signal, reduces the system volume and installation and adjustment difficulty, and reduces the preparation cost.

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Abstract

The present invention discloses a compact extreme ultraviolet broadband spectrometer, comprising a laser plasma light source and a bearing mechanism, wherein the bearing mechanism comprises a light source cavity and a collection cavity whose axes are in the same straight line, wherein the light source cavity is connected to the collection cavity through a first connecting tube, a light splitting element is arranged on the upper surface of the light source cavity, a non-periodic Al / Zr multilayer film spherical reflector is arranged on the upper surface of the collection cavity, a CCD sensor is connected to the other side of the light source cavity through a second connecting tube, and a stray light suppression mechanism is arranged on the second connecting tube between the CCD sensor and the light splitting element. The present invention adopts the above-mentioned compact extreme ultraviolet broadband spectrometer, while ensuring the spectral resolution and transmission efficiency, avoids the additional space requirement and the introduction of additional aberrations caused by the use of a reflective grating, and improves the spectral resolution.
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Description

Technical Field

[0001] The invention relates to the technical field of spectrum analysis instruments, and in particular to a compact extreme ultraviolet broadband spectrometer. Background Art

[0002] Spectroscopic research in the extreme ultraviolet band (10 - 60 nm) plays a vital role in science and industry. The 24 - 32 nm band is closely related to research in plasma diagnostics, materials science, semiconductor manufacturing, and astronomy, and has extremely high research value. The extreme ultraviolet spectrometer provides a high-resolution spectral research method, which is of great significance for the in-depth characterization of the electronic structure, energy level transitions, and plasma characteristics of materials. However, the current extreme ultraviolet spectrometer still has some shortcomings:

[0003] 1) Traditional extreme ultraviolet spectrometers widely use grazing incidence structures. This design allows light to be reflected at an angle close to the surface, thereby reducing light absorption and scattering. It can achieve higher reflectivity in the high-energy photon band and is suitable for high-resolution spectral research. However, this structure brings the following disadvantages: ① The large-angle reflection element makes the spectrometer larger. ② In order to reduce the aberration caused by the grazing incidence structure, the grazing incidence element needs to have a more complex surface shape (such as a toroid, cylinder, etc.), which increases the difficulty and cost of component preparation. ③ The assembly and calibration process of the grazing incidence structure is relatively difficult, which greatly affects the application of the spectrometer system.

[0004] 2) Although some EUV spectrometers use a normal-incidence structure, which is more compact and has lower system assembly difficulty and preparation cost, they face the problem of low system efficiency. With the emergence of multilayer film technology, the efficiency of reflective elements under normal-incidence working conditions has been greatly improved, such as the 13.5 nm Mo / Si multilayer film used in lithography technology. In addition, in order to expand the application bandwidth, non-periodic multilayer film technology has also been more widely used. However, for the 24-32 nm band, the traditional Mo / Si material pair does not show good reflection performance. The maximum uniform reflectivity that can be achieved in theory is only 10%, and the problem of low efficiency of the spectrometer system still exists.

[0005] 3) Some EUV spectrometers use gas discharge plasma equipment or synchrotron radiation accelerators as the EUV light source of the system. The former is a common laboratory light source with good radiation stability, but it has disadvantages such as low intensity and discontinuous spectrum, which greatly limits the performance of the spectrometer. Synchrotron radiation light source can produce high-stability, high-intensity continuous radiation, but its use has a complex process and is limited by the user's machine time, making the application of spectrometers more difficult. Summary of the invention

[0006] The purpose of the present invention is to provide a compact extreme ultraviolet broadband spectrometer, which solves the problems of large system volume and difficult installation and adjustment caused by the grazing incidence structure of traditional extreme ultraviolet band spectrometers.

[0007] To achieve the above-mentioned purpose, the present invention provides a compact extreme ultraviolet broadband spectrometer, comprising a laser plasma light source and a supporting mechanism, wherein the supporting mechanism comprises a light source cavity and a collecting cavity whose axes are on the same straight line, the light source cavity is connected to the collecting cavity through a first connecting tube, a spectroscopic element is arranged on the upper surface of the light source cavity, a non-periodic Al / Zr multilayer spherical reflector is arranged on the upper surface of the collecting cavity, a CCD sensor is connected to the other side of the light source cavity through a second connecting tube, and a stray light suppression mechanism is arranged on the second connecting tube between the CCD sensor and the spectroscopic element.

[0008] Preferably, the light source cavity and the collecting cavity are both cylindrical cavity structures with closed upper and lower ends, the diameter of the light source cavity is larger than the diameter of the collecting cavity, the interiors of the light source cavity and the collecting cavity are both vacuum environments, and four waist-shaped holes are provided at the bottom of the light source cavity and the collecting cavity.

[0009] Preferably, the non-periodic Al / Zr multilayer spherical reflector is used to collect the extreme ultraviolet plasma radiation generated by the laser plasma light source and focus the extreme ultraviolet plasma radiation onto the surface of the CCD sensor;

[0010] The non-periodic Al / Zr multilayer spherical reflector has an aperture of 25.4 mm and a thickness of 7 mm. The non-periodic Al / Zr multilayer spherical reflector adopts a concave spherical substrate made of SiO2. The surface roughness of the concave spherical surface after fine polishing is less than 0.5 nm, the radius of curvature is 641.523 mm, and the error is less than 0.5%;

[0011] The non-periodic Al / Zr multilayer spherical reflector is made by stacking film layers with different periodic thicknesses. The absorption edges of Al and Zr of the non-periodic Al / Zr multilayer spherical reflector are both far away from the 24-32 nm band. The working angle of the non-periodic Al / Zr reflector is an incident angle of 2°. The distance between the non-periodic Al / Zr reflector and the laser plasma light source is 500 mm, and the distance between the non-periodic Al / Zr reflector and the CCD sensor is 900 mm.

[0012] Preferably, the spectroscopic element is used to split the plasma extreme ultraviolet radiation spectrum, the spectroscopic element is fixed at a distance of 300 mm from the CCD sensor through a first optical bracket, and the spectroscopic element uses a 1000 line / mm large-aperture gold transmission grating;

[0013] The stray light suppression mechanism is used to filter out visible light and protect the CCD sensor. The stray light suppression mechanism includes an Al filter. The thickness of the Al filter is 200 nm. The CCD sensor is used to convert photoelectric signals into electrical signals, and transmit and read them through charge coupling to form images.

[0014] Preferably, the laser plasma light source includes a Nd:YAG laser, a focusing lens, a target material and an optical slit, the focusing lens is used to focus high-intensity pulsed laser onto the target material, the focusing lens is fixed to a one-dimensional manual adjustment platform through a second optical bracket, the focusing lens is arranged in front of the Nd:YAG laser, the target material is vertically arranged on the upper surface of the light source cavity through a one-dimensional electric lifting platform, and the distance between the center of the focusing lens and the target material is 480mm~500mm.

[0015] Preferably, the target material is made of one of aluminum, copper, silicon, tungsten, iron, magnesium, titanium or molybdenum, and the length, width and height of the target material are 100 mm×25 mm×5 mm respectively.

[0016] Preferably, the one-dimensional electric lifting platform includes a table top and a cross roller guide slidably connected to the table top, the cross roller guide is vertically arranged on the upper surface of the light source cavity, the upper surface of the light source cavity is provided with a driving motor, the output shaft of the driving motor is fixedly provided with a threaded screw, the threaded screw passes through the table top and is slidably connected to the table top.

[0017] Preferably, a slider cooperating with the cross roller guide is arranged on the table top, the length and width of the table top are 125 mm×100 mm respectively, the load-bearing capacity of the table top is not less than 8 kg, and the stroke of the one-dimensional electric lifting platform is 75 mm.

[0018] Preferably, the driving motor communicates with an external controller through a flange with a high vacuum lead, and a third optical bracket is arranged 10 mm away from the laser plasma light source point, a circular molybdenum sheet is arranged on the third optical bracket, and the optical slit is etched on the circular molybdenum sheet, the thickness of the circular molybdenum sheet is 1 mm, the diameter is 25.4 mm, and the length and width of the optical slit are 100 mm×10 μm, respectively.

[0019] Preferably, the non-periodic Al / Zr reflector is equipped with a three-dimensional manual adjustment stage and a one-dimensional electric adjustment stage in the X direction;

[0020] The three-dimensional manual adjustment stage includes a yaw and pitch adjustment stage and a Y-direction translation stage, which are used for posture calibration during the installation process. The one-dimensional electric adjustment stage in the X direction is used to fine-tune the reflector posture in a vacuum environment to optimize the focusing performance.

[0021] Therefore, the present invention adopts the above-mentioned compact extreme ultraviolet broadband spectrometer, and the beneficial effects are as follows:

[0022] The present invention adopts a non-periodic Al / Zr multilayer spherical mirror to realize a normal-incident spectrometer structure, has high light transmission efficiency in the 24-32nm band, and enhances the intensity of spectral signals.

[0023] (2) The normal incidence design of the present invention makes the optical path of the spectrometer simpler, reduces the system volume, realizes a compact structural design, makes installation and calibration easier, and reduces the system preparation cost.

[0024] (3) The laser plasma light source provided in the present invention provides the spectrometer system with extreme ultraviolet radiation of higher intensity and continuous spectrum.

[0025] (4) The present invention uses a large-aperture gold transmission grating with a speed of 1000 lines / mm as a spectroscopic element, and sets the aperture to 10 mm. The diffraction process does not change the direction of the light path, and has high diffraction efficiency in the 24-32 nm band, thereby improving the spectral resolution.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a compact extreme ultraviolet broadband spectrometer of the present invention;

[0028] Figure 2 The figure is a side view of a one-dimensional electric lifting platform of an embodiment of a compact extreme ultraviolet broadband spectrometer of the present invention.

[0029] Reference numerals

[0030] 1. Light source cavity; 2. Collecting cavity; 3. First connecting tube; 4. Spectroscopic element; 5. Non-periodic Al / Zr multilayer spherical reflector; 6. Second connecting tube; 7. CCD sensor; 8. Stray light suppression mechanism; 9. Nd:YAG laser; 10. Focusing lens; 11. Target material; 12. Threaded screw; 13. Optical slit; 14. Table; 15. Cross roller guide; 16. Drive motor. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0032] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] As shown in the figure, a compact 24-32nm extreme ultraviolet broadband spectrometer includes a laser plasma light source and a supporting mechanism. The supporting mechanism includes a light source cavity 1 and a collecting cavity 2 whose axes are on the same straight line. A spectroscopic element 4 is arranged on the upper surface of the light source cavity 1, and a non-periodic Al / Zr multilayer spherical reflector 5 is arranged on the upper surface of the collecting cavity 2. A CCD sensor 7 is connected to the other side of the light source cavity 1 through a second connecting tube 6, and a stray light suppression mechanism 8 is arranged on the second connecting tube 6 between the CCD sensor 7 and the spectroscopic element 4.

[0034] Among them, the laser plasma light source is used to generate extreme ultraviolet plasma radiation, the non-periodic Al / Zr multilayer spherical reflector 5 is used to collect the extreme ultraviolet plasma radiation generated by the laser plasma light source, and focus the extreme ultraviolet plasma radiation in the 24-32mm band onto the surface of the CCD sensor 7; the spectroscopic element 4 is installed between the non-periodic Al / Zr multilayer spherical reflector 5 and the CCD sensor 7, and is used to spectroscopically analyze the plasma 24-32mm extreme ultraviolet radiation spectrum; the stray light suppression mechanism 8 is used to filter out visible light and protect the CCD sensor 7, and the CCD sensor 7 converts the photoelectric signal into an electric charge through the photoelectric effect, transfers and converts it into an electrical signal line by line, and finally generates a digital image through analog-to-digital conversion.

[0035] Compared with the prior art, the present invention uses a non-periodic Al / Zr multilayer spherical reflector 5 in a spectrometer system for the first time, thereby realizing 24-32nm broadband high-efficiency spectral detection under normal incidence conditions.

[0036] The light source cavity 1 and the collecting cavity 2 in the whole system bearing mechanism are both cylindrical cavity structures made of stainless steel with closed ends. The diameter of the light source cavity 1 is larger than the diameter of the collecting cavity 2. Specifically, the diameter of the light source cavity 1 is 400 mm, the diameter of the collecting cavity 2 is 250 mm, the cavity wall thickness of the light source cavity 1 and the collecting cavity 2 is 6 mm, and the interior of the light source cavity 1 and the collecting cavity 2 are both vacuum environments. The above-mentioned size and structure settings enable the entire device to withstand the pressure brought by the ultra-high vacuum environment without deformation. The light source cavity 1 is connected to the collecting cavity 2 through the first connecting tube 3. The first connecting tube 3 can be an ISO 100 stainless steel bellows with a length of 100 mm. The bottom of the light source cavity 1 and the collecting cavity 2 are both provided with four waist-shaped holes with a length of 25 mm and an outer diameter of 6.6 mm, which can fix the device on the required optical platform.

[0037] The laser plasma light source includes a Nd:YAG laser 9, a focusing lens 10, a target 11 and an optical slit 13. The focusing lens 10 with F=500mm (focal length 500mm) is used to focus the high-intensity pulsed laser onto the target 11. The focusing lens 10 is fixed on a one-dimensional manual adjustment platform through a second optical bracket, and can be fine-tuned along the laser incident direction to obtain different laser focusing conditions. The focusing lens 10 is arranged in front of the Nd:YAG laser 9, and the distance between the center of the focusing lens 10 and the target 11 is 480mm~500mm.

[0038] In order to meet different research and use requirements, the spectrometer system is equipped with a variety of target materials 11, including but not limited to one of aluminum, copper, silicon, tungsten, iron, magnesium, titanium or molybdenum with a purity of ≥99.99%, and the length, width and height of the target material 11 are 100 mm×25 mm×5 mm respectively. The target material 11 is vertically set on the upper surface of the light source cavity 1 through a one-dimensional electric lifting platform, and the target material can be translated by ±37.5 mm in the direction perpendicular to the ground. The life of each target material 11 is more than 30,000 laser pulses.

[0039] The one-dimensional electric lifting platform includes a table 14 and a cross roller guide 15 slidably connected to the table 14. The length and width of the table 14 are 125 mm×100 mm respectively. The table 14 is 40 mm from the ground and 500 mm from the target. The load-bearing capacity of the table 14 is not less than 8 kg. The cross roller guide 15 is vertically arranged on the upper surface of the light source cavity 1. The upper surface of the light source cavity 1 is provided with a driving motor 16. The output shaft of the driving motor 16 is fixedly provided with a precision threaded screw 12 with a pitch of 1 mm. The threaded screw 12 passes through the table 14 and is slidably connected to the table 14. A slider that cooperates with the cross roller guide 15 is arranged on the table 14. The stroke of the one-dimensional electric lifting platform is set to 75 mm, which can realize the effective translation of the target 11.

[0040] During specific operation, the drive motor 16 communicates with the external controller through a specially made flange with a high vacuum lead. A two-phase stepper motor is selected as the drive motor 16. When a precision threaded screw 12 with a pitch of 1 mm is used for advancement, the table 14 can rise or fall along the cross roller guide 15. The repeat positioning accuracy is set to ±1 μm. During displacement, the left and right and front and back offsets of the table 14 are less than 12 μm, which ensures the movement stability of the target 11 to the greatest extent.

[0041] When the high-intensity pulsed laser is focused onto the target 11, it will generate rad radiation. In order to improve the spectral resolution of the system, an optical slit 13 is provided behind the light source. Specifically, a third optical bracket is provided 10 mm away from the laser plasma light source, and a circular molybdenum sheet is provided on the third optical bracket. The optical slit 13 is etched on the circular molybdenum sheet. The thickness of the circular molybdenum sheet is 1 mm and the diameter is 25.4 mm. The length and width of the optical slit 13 are 100 mm×10 μm respectively. The setting of the optical slit 13 enables the spectrometer system to have a spectral resolution better than 0.15 nm.

[0042] In order to solve the problem of low efficiency of traditional spectrometers in the 24-32 nm band, the present invention designs and prepares a non-periodic Al / Zr multilayer spherical reflector 5 for use in this band. The principle is to expand the reflection wavelength bandwidth of the multilayer film by superimposing film layers of different periodic thicknesses.

[0043] Specifically, the absorption edges of Al and Zr of the non-periodic Al / Zr multilayer spherical reflector 5 are far away from the 24-32 nm band, which can provide a higher reflectivity. At the same time, the Al / Zr material pair can form a uniform and flat film layer and has good thermal stability. Through design optimization, this non-periodic Al / Zr multilayer film can achieve a theoretical uniform reflectivity of about 20% in the 24-32 nm band.

[0044] The diameter of the non-periodic Al / Zr multilayer spherical reflector 5 is 25.4 mm and the thickness is 7 mm. In the preparation process of the non-periodic Al / Zr multilayer spherical reflector 5, a concave spherical substrate made of SiO2 is used. After the concave spherical surface (reflecting surface) is finely polished, the surface roughness is less than 0.5 nm, the radius of curvature is 641.523 mm, and the error is less than 0.5%.

[0045] The non-periodic Al / Zr reflector 5 is equipped with a three-dimensional manual adjustment stage and a one-dimensional electric adjustment stage in the X direction; the three-dimensional manual adjustment stage includes a yaw and pitch adjustment stage and Figure 1The Y-direction translation stage is used for posture calibration during the installation process; the X-direction one-dimensional electric adjustment stage is used to fine-tune the mirror posture in a vacuum environment to optimize the focusing performance. At the same time, the working angle of the non-periodic Al / Zr reflector 5 is set to an incident angle of 2°, the distance between the non-periodic Al / Zr reflector 5 and the laser plasma light source is 500 mm, and the distance between the non-periodic Al / Zr reflector 5 and the CCD sensor 7 is 900 mm.

[0046] The spectroscopic element 4 is fixed at a distance of 7300 mm from the CCD sensor by the first optical bracket. In this spectrometer system, a 1000 line / mm large-aperture gold transmission grating is selected as the spectroscopic element 4, which has a light-transmitting area of ​​10 mm×10 mm and a sufficiently high line density, provides a larger dispersion angle, and ensures the spectral resolution.

[0047] At the same time, the self-supporting structure avoids the aberration introduced by the reflective grating, further improving the spectral resolution. In addition, the gold material itself has low absorption characteristics and excellent thermal stability in the extreme ultraviolet band, so the gold grating can diffract EUV radiation more efficiently.

[0048] The stray light suppression mechanism 8 is used to filter out visible light and protect the CCD sensor 7. The stray light suppression mechanism 8 includes an Al filter. The Al filter as a core component has a thickness of 200 nm. It can not only suppress the visible light entering the CCD sensor 7 to reduce the background noise, but also suppress short-wave radiation below 17 nm to reduce the impact of high-order harmonics on the experimental results.

[0049] At the same time, the 200 nm thick Al filter still retains a high light transmission efficiency at 24-32 nm, with an average transmittance of about 70%. The CCD sensor 7 used is a semiconductor device for photoelectric detection, which converts photoelectric signals into electrical signals, transmits and reads them through charge coupling to form an image. The effective detection area of ​​this CCD sensor 7 is 13 mm×13 mm, which can completely cover the 0-32 nm band range. The single pixel size of its detection surface is 13 μm×13 μm, which can provide extremely high spatial and spectral resolution. And the CCD sensor 7 has low noise characteristics when working under low temperature conditions. Since EUV signals are usually weak, low noise levels help to improve the signal-to-noise ratio, thereby obtaining clearer and more accurate spectral data. It is worth noting that unlike most CCD detections in the visible light band, this CCD sensor 7 is coated with a special coating to ensure high detection efficiency in the extreme ultraviolet band.

[0050] Therefore, the present invention adopts the above-mentioned compact extreme ultraviolet broadband spectrometer to solve the problems of large system volume and difficult installation and adjustment caused by the grazing incidence structure of the traditional extreme ultraviolet band spectrometer. A 24-32 nm spectrometer based on the normal incidence structure was designed and built. Its core component is the non-periodic Al / Zr multilayer film reflector 5, which can have a uniform reflectivity of about 20% under the condition of an incident angle of 2°, which makes the normal incidence compact structure possible. At the same time, a 1000m line / mm normal incidence gold grating is used in the system as a spectroscopic element 4, which avoids the additional space requirements and the introduction of additional aberrations caused by the use of a reflective grating while ensuring the spectral resolution and transmission efficiency, thereby improving the spectral resolution.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A compact extreme ultraviolet broadband spectrometer, characterized in that: It comprises a laser plasma light source and a bearing mechanism, wherein the bearing mechanism comprises a light source cavity and a collection cavity whose axes are in the same straight line, the light source cavity is connected with the collection cavity through a first connecting tube, a light splitting element is arranged on the upper surface of the light source cavity, a non-periodic Al / Zr multilayer film spherical reflector is arranged on the upper surface of the collection cavity, a CCD sensor is connected to the other side of the light source cavity through a second connecting tube, and a stray light suppression mechanism is arranged on the second connecting tube between the CCD sensor and the light splitting element; The light source cavity and the collection cavity are both cylindrical cavity structures with closed upper and lower ends, the diameter of the light source cavity is larger than the diameter of the collection cavity, the interiors of the light source cavity and the collection cavity are both vacuum environments, and the bottoms of the light source cavity and the collection cavity are both provided with four waist-shaped holes; The non-periodic Al / Zr multilayer spherical reflector is used to collect the extreme ultraviolet plasma radiation generated by the laser plasma light source and focus the extreme ultraviolet plasma radiation onto the surface of the CCD sensor; The non-periodic Al / Zr multilayer spherical reflector has an aperture of 25.4 mm and a thickness of 7 mm. The non-periodic Al / Zr multilayer spherical reflector adopts a concave spherical substrate made of SiO2. The surface roughness of the concave spherical surface after fine polishing is less than 0.5 nm, the radius of curvature is 641.523 mm, and the error is less than 0.5%; The non-periodic Al / Zr multilayer spherical reflector is made by stacking film layers with different periodic thicknesses. The absorption edges of Al and Zr of the non-periodic Al / Zr multilayer spherical reflector are both far away from the 24-32 nm band. The working angle of the non-periodic Al / Zr reflector is an incident angle of 2°. The distance between the non-periodic Al / Zr reflector and the laser plasma light source is 500 mm, and the distance between the non-periodic Al / Zr reflector and the CCD sensor is 900 mm.

2. A compact extreme ultraviolet broadband spectrometer according to claim 1, characterized in that: The spectroscopic element is used for spectroscopic analysis of plasma extreme ultraviolet radiation spectrum. The spectroscopic element is fixed at a distance of 300 mm from the CCD sensor through a first optical bracket. The spectroscopic element uses a 1000 line / mm large-aperture gold transmission grating. The stray light suppression mechanism is used to filter out visible light and protect the CCD sensor. The stray light suppression mechanism includes an Al filter. The thickness of the Al filter is 200 nm. The CCD sensor is used to convert photoelectric signals into electrical signals, and transmit and read them through charge coupling to form images.

3. A compact extreme ultraviolet broadband spectrometer according to claim 2, characterized in that: The laser plasma light source comprises a Nd:YAG laser, a focusing lens, a target material and an optical slit. The focusing lens is used to focus high-intensity pulsed laser onto the target material. The focusing lens is fixed on a one-dimensional manual adjustment platform through a second optical bracket. The focusing lens is arranged in front of the Nd:YAG laser. The target material is vertically arranged on the upper surface of the light source cavity through a one-dimensional electric lifting platform. The distance between the center of the focusing lens and the target material is 480 mm to 500 mm.

4. A compact extreme ultraviolet broadband spectrometer according to claim 3, characterized in that: The target material is made of one of aluminum, copper, silicon, tungsten, iron, magnesium, titanium or molybdenum, and the length, width and height of the target material are 100 mm×25 mm×5 mm respectively.

5. A compact extreme ultraviolet broadband spectrometer according to claim 4, characterized in that: The one-dimensional electric lifting platform includes a table top and a cross roller guide slidably connected to the table top, the cross roller guide is vertically arranged on the upper surface of the light source cavity, the upper surface of the light source cavity is provided with a driving motor, the output shaft of the driving motor is fixedly provided with a threaded screw, the threaded screw passes through the table top and is slidably connected to the table top.

6. A compact extreme ultraviolet broadband spectrometer according to claim 5, characterized in that: The table top is provided with a slider matched with the cross roller guide rail. The length and width of the table top are 125 mm×100 mm respectively. The load-bearing capacity of the table top is not less than 8 kg. The stroke of the one-dimensional electric lifting platform is 75 mm.

7. A compact extreme ultraviolet broadband spectrometer according to claim 6, characterized in that: The driving motor communicates with an external controller through a flange with a high vacuum lead. A third optical bracket is arranged 10 mm away from the laser plasma light source point. A circular molybdenum sheet is arranged on the third optical bracket. The optical slit is etched on the circular molybdenum sheet. The thickness of the circular molybdenum sheet is 1 mm and the diameter is 25.4 mm. The length and width of the optical slit are 100 mm×10 μm, respectively.

8. A compact extreme ultraviolet broadband spectrometer according to claim 7, characterized in that: The non-periodic Al / Zr reflector is equipped with a three-dimensional manual adjustment stage and a one-dimensional electric adjustment stage in the X direction; The three-dimensional manual adjustment stage includes a yaw and pitch adjustment stage and a Y-direction translation stage, which are used for posture calibration during the installation process. The one-dimensional electric adjustment stage in the X direction is used to fine-tune the reflector posture in a vacuum environment to optimize the focusing performance.

Citation Information

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