Quartz curved crystal monochromator and its preparation method and application

Abstract

The present invention belongs to the technical field of semiconductor material finishing, and relates to a quartz bent crystal monochromator and a preparation method and application thereof. In view of the technical problems that the quartz bent crystal monochromator in the prior art needs to cut the quartz twice on the front and back sides, the success rate is low, the number of scribing times is large, the time consumption is long, the cutting efficiency is low, and it is easy to break, the cutting edge is not neat, and it is easy to collapse. The stress after bending is propagated to the surface, which affects the energy resolution. The quartz bent crystal monochromator provided in the present application includes a quartz array bonded to a concave glass through a flat glass; the quartz array includes a plurality of single crystal quartz bonded to the flat glass; the collapse of the single crystal quartz is less than 15μm. The cutting edge is neat, the collapse size is small, and the energy resolution is high. The present application also provides a method for preparing a quartz bent crystal monochromator, which reduces the number of quartz scribing times, reduces the processing time, and improves the efficiency and success rate of quartz cutting.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor material finishing, and in particular, relates to a quartz bent crystal monochromator and a preparation method and application thereof. Background Art

[0002] Optical devices based on X-ray diffraction, such as monochromators, analytical crystals, and polarizers, are usually made of single crystal silicon or germanium. However, single crystal silicon or germanium crystals belong to the cubic system, and their highly symmetrical crystal structure makes the available Bragg reflection surface very limited. Silicon-based X-ray optical devices made of them are difficult to work at any photon energy, especially in experiments such as X-ray absorption spectroscopy and emission spectroscopy, which require photon energy close to various atomic absorption edges or emission lines. One solution is to use low-symmetry crystals, such as single crystal quartz crystals (-SiO2), whose structure belongs to the trigonal system and the space group is P3121 (No.152). In the energy range of 5~16KeV, quartz has up to 420 different near-backscattering diffraction surfaces. Therefore, it can be used to make X-ray monochromators or spherically curved analytical crystals. For a specific energy, one or more diffraction surfaces can always be selected to achieve near-backscattering diffraction conditions, thereby reducing Johannsen errors and improving the energy resolution of curved crystal monochromators.

[0003] The spherical curved crystal monochromator is the core optical element of the Rowland circle, which has the dual functions of energy dispersion and focusing. It is usually made of single crystal silicon or germanium and other materials pressed on a spherical substrate. The high energy resolution curved crystal monochromator needs to eliminate the stress or lattice distortion caused by bending, so as to achieve the intrinsic Darwin broadening close to the flat crystal diffraction. In this process, it is necessary to enter the slotting and scribing process, and appropriately increase the thickness of the single crystal material to reduce the stress broadening caused by the cutting process or the edge collapse effect.

[0004] At present, mechanical diamond cutting is the mainstream technology of the dicing process. It mainly uses diamond knives to cut and split hard and brittle materials into smaller units. Its working principle is to use strong grinding as the dicing mechanism. The air spindle drives the diamond blade to cut the wafer at a high speed of 10,000 to 40,000 revolutions per minute. At the same time, the workbench carrying the wafer moves linearly along the tangent direction of the contact point between the blade and the wafer at a certain speed, dividing the wafer into pixel arrays of specific sizes. The debris generated by cutting the wafer is washed away by deionized water. In the dicing machine, there are two types of spindles, namely DC spindles and AC spindles. The DC spindle has higher speed control accuracy, less vibration, and better dicing effect, but the torque is relatively small compared to the same power AC spindle, and the cutting force is insufficient for thicker and harder quartz, ceramics, etc. The AC spindle has a larger torque and larger vibration, which is mainly for products with harder materials and lower cutting accuracy requirements. Due to the brittleness of single crystal materials, mechanical cutting methods will generate mechanical stress on the front and back of the wafer, resulting in edge collapse at the edge of the cut groove. The tools and materials used in the cutting process mainly include: dicing blades and carrier films. The dicing process parameters mainly include: cutting mode, step speed, blade speed, cutting depth, etc. Due to the large differences in the physical properties of different crystals, it is necessary to iteratively optimize the dicing process parameters to achieve the best cutting quality and the best success rate.

[0005] In the manufacturing process of bent crystal monochromators, in order to reduce the impact of bending stress on lattice distortion, it is usually necessary to use single crystal materials with a thickness of about 2.5~3 mm. The thicker the material, the smaller the surface stress, but the correspondingly greater the processing difficulty. A typical dicing machine can cut a material of up to about 3 mm thick.

[0006] The publication number of the Chinese invention patent application is CN115308240A, and the application date is November 8, 2022. The name of the invention is "Analytical crystals, their preparation methods and applications", which discloses an analytical crystal, its preparation method and application, including a substrate and a plurality of single crystal wafers attached to the surface of the substrate, and the preparation method includes: transferring the plurality of single crystal wafers to a blue film; pressing and bonding the plurality of single crystal wafers transferred to the blue film to the surface of the substrate; and removing the blue film. The scheme does not mention how to use a diamond knife to cut a single crystal wafer into strip crystals, and unlike the processing of single crystal silicon, quartz has a high hardness and is very fragile. The processing steps are complicated and the success rate is extremely low. It is difficult to make a large-size, high-energy resolution bent crystal monochromator on the order of hundreds of millimeters.

[0007] As mentioned in the literature [Ayman H. Said, Thomas Gog, Michael Wieczorek, XianRongHuang, Diego Casa, Elina Kasman, Ralu Divanb and Jung Ho Kim, High-energy-resolution diced spherical quartz analyzers for resonant inelastic X-rayscattering, J. Synchrotron Rad. (2018). 25, 373–377], a 2 mm thick single crystal quartz was selected, and the depth of each dicing was 250 μm. The dicing and grooving process parameters are as follows:

[0008]

[0009] The production process requires cutting quartz twice, front and back, with a low success rate. At the same time, in order to ensure that quartz does not crack during cutting, the technology controls the cutting depth of a single slice to 250μm, which is relatively low, so that a quartz sheet with a thickness of 2mm needs to be cut 8 times. The cutting efficiency is low and the time consumption is long. At the same time, the selection of quartz with a thickness of 2mm will cause the stress after bending to propagate to the surface, affecting the energy resolution of quartz. Summary of the invention

[0010] 1. Problems to be solved

[0011] The quartz bent crystal monochromator of the prior art needs to cut the quartz twice, front and back, with a low success rate, many scribing times, long time consumption, low cutting efficiency, easy to break, uneven cutting edges, easy to collapse, and the stress after bending is transmitted to the surface, affecting the technical problem of energy resolution. The quartz bent crystal monochromator provided by the present application has neat cutting edges, small collapse size, and high energy resolution. The present application also provides a method for preparing a quartz bent crystal monochromator, which reduces the number of quartz scribing times, reduces processing time, and improves the efficiency and success rate of quartz cutting.

[0012] 2. Technical solution

[0013] In order to achieve the above purpose, the technical solution provided is:

[0014] A quartz bent crystal monochromator, comprising a quartz array bonded to a concave glass via a flat glass; the quartz array comprises a plurality of single crystal quartz bonded to the flat glass;

[0015] The edge chipping of the single crystal quartz is less than 15 μm.

[0016] Furthermore, the quartz array is 50 mm long, 25 mm wide, and 2.25 mm high, and the interval between adjacent single crystal quartz is 1 mm.

[0017] Furthermore, the flat glass or concave glass is high borosilicate glass; the flat glass is 0.5 mm thick; the concave glass is 12 mm thick; and the curvature of the concave glass is 0.5 m to 2 m.

[0018] The method for preparing a quartz bent crystal monochromator comprises the following steps:

[0019] S1. Obtain backscattered diffraction spots using a Laue camera, compare with theoretical results to confirm that the crystal orientation is correct, fix a quartz single crystal material with a thickness of X on a blue film to obtain a single crystal quartz wafer, and groove the single crystal quartz wafer with a groove depth of Y to obtain a grooved single crystal quartz wafer;

[0020] S2. The grooved surface of the grooved single crystal quartz wafer is bonded to the flat glass, and the grooved single crystal quartz wafer is etched away from the flat glass side to a thickness of XY to obtain a quartz array;

[0021] S3. The quartz array is bent and bonded to the concave glass to obtain a quartz bent crystal monochromator;

[0022] The edge collapse of the single crystal quartz in the quartz bent crystal monochromator is less than 15 μm.

[0023] Furthermore, in step S1, the process parameters of the grooving are: using a diamond dicing machine, the main shaft is a 1.5Kw AC shaft, the cutting speed is 0.3mm / s, the blade thickness is 0.5mm, the blade speed is 20000rpm, and the cutting depth is 400μm.

[0024] Furthermore, in step S1, the thickness of the single crystal quartz wafer is 2.5 mm and the diameter is 4 inches; the slotting method is a rectangular array with a spacing of 1 mm, and the slotting depth is 2.25 mm.

[0025] Furthermore, in step S2, the bonding uses epoxy resin glue with a curing temperature of 85° C. and a curing time of 3 hours.

[0026] Furthermore, in step S2, hydrofluoric acid is used for etching; the concentration of the hydrofluoric acid is 40%wt.

[0027] Furthermore, the flat glass or the concave glass is high borosilicate glass; the flat glass is 0.5 mm thick, the concave glass is 12 mm thick, and the curvature of the concave glass is 0.5 m to 2 m.

[0028] The application of quartz bent crystal monochromator is applied to X-ray Rowland spectrometer or X-ray absorption spectrum analyzer.

[0029] 3. Beneficial effects

[0030] Compared with the existing known technology, the technical solution provided by the present invention has the following beneficial effects:

[0031] (1) The quartz bent crystal monochromator of the present invention comprises a quartz array bonded to a concave glass via a flat glass, wherein the quartz array comprises a plurality of single crystal quartz bonded to the flat glass; the chipping edge of the single crystal quartz is less than 15 μm, the cutting edge is neat, the chipping edge size is small, and the energy resolution is high.

[0032] (2) The preparation method of the quartz curved crystal monochromator of the present invention is to fix a quartz single crystal material with a thickness of X on a blue film, and groove the material to a depth of Y; the grooved surface is bonded to a flat glass, etched to an etching thickness of XY, and bonded to a concave glass to obtain a quartz curved crystal monochromator; the edge collapse of the single crystal quartz in the quartz curved crystal monochromator is less than 15μm. Through the complete diamond dicing machine cutting parameters, the crystal breakage caused by cutting can be effectively avoided, and the grooving cutting of large-size quartz crystals with low edge collapse and high success rate can be obtained. The thin wall left by mechanical cutting is removed by etching, so that the flat crystal pixel array can be obtained by only performing a physical slicing and grooving process on the quartz once. The problem of quartz breakage caused by multiple grooving is effectively avoided, and the efficiency and success rate of quartz cutting are improved. At the same time, the energy broadening caused by the bending stress is avoided, and the preparation of a large-size, high-resolution quartz curved crystal monochromator is realized.

[0033] (3) Application of the quartz bent crystal monochromator of the present invention. The quartz bent crystal monochromator is applied to an X-ray Rowland spectrometer or an X-ray absorption spectrometer, and can cover a wide range of Bragg angles and energy measurement ranges. The high energy resolution of the quartz bent crystal monochromator enables the spectrometer to obtain high-precision spectral data. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the production process of a quartz bent crystal monochromator;

[0035] Figure 2 This is a photo of the cutting edge observed under a 50x microscope;

[0036] Figure 3 This is a line graph of edge collapse data of the quartz bent crystal monochromator prepared in the implementation;

[0037] Figure 4 This is a photo of a crack-free quartz pixel flat crystal array. DETAILED DESCRIPTION

[0038] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with embodiments.

[0039] Example 1

[0040] The quartz bent crystal monochromator and its preparation method and application in this embodiment have the following specific steps:

[0041] Instrument: Diamond dicing machine (domestic dicing machine, Jiangsu Jingchuang Advanced Electronic Technology Co., Ltd., AR3000).

[0042] Material: Quartz single crystal material: 244 crystal orientation is preferred; crystal thickness is 2.5 mm; crystal diameter is 4 inches.

[0043] Planar glass substrate: preferably high borosilicate glass with a thickness of 0.5 mm.

[0044] Concave glass substrate: preferably high borosilicate glass, with a thickness of 12 mm and a concave curvature of 0.5 m to 2 m.

[0045] S1. Use a Laue camera to obtain backscattered diffraction spots. After comparing with the theoretical results to confirm that the crystal orientation is correct, a quartz single crystal material with a thickness of 2.5 mm is fixed on a blue film to obtain a single crystal quartz wafer. The single crystal quartz wafer is slotted in a rectangular array with a spacing of 1 mm. The slot depth is 2.25 mm. The main axis is a 1.5KW AC axis. The cutting parameters are shown in Table 1 to obtain a slotted single crystal quartz wafer (see Table 1). Figure 1 ①②);

[0046] Table 1 Diamond dicing machine cutting parameters

[0047]

[0048] S2. Bond the slotted surface of the slotted single crystal quartz wafer to the flat glass. Use epoxy resin glue, preferably EPO-TEK@353ND, with a curing temperature of 85°C and a curing time of 3 hours. Etch the side of the slotted single crystal quartz wafer away from the flat glass to a thickness of 0.25 mm to obtain a quartz array (see Figure 1 ③④⑤);

[0049] The specific etching method is to place the side of the slotted single crystal quartz wafer away from the flat glass into a glass vessel containing a 40%wt hydrofluoric acid solution, perform chemical etching, and control the height of the hydrofluoric acid solution to avoid corrosion to the glue layer;

[0050] S3. Bond the quartz array to the concave glass to obtain a quartz bent crystal monochromator (see Figure 1 (6)

[0051] The slotting process in step S1 of this embodiment has obtained a set of cutting parameters with a high success rate through repeated experiments, which can effectively avoid crystal breakage caused by cutting, and obtain slotting cutting of large-sized quartz crystals with low edge collapse and high success rate. The main spindle uses a 1.5KW AC axis, which can effectively cut quartz materials with high hardness; the single cutting depth is 400μm, which effectively reduces the number of quartz dicing and processing time, and improves the efficiency and success rate of quartz cutting.

[0052] In step S2, hydrofluoric acid is used to chemically etch the thin wall left by mechanical cutting, so that the flat-crystal pixel array can be obtained by only performing one physical slicing and grooving process on the quartz, effectively avoiding the problem of quartz cracking caused by multiple grooving.

[0053] In addition, in this embodiment, no anti-corrosion glue is used. Instead, ordinary epoxy resin glue is used to bond the quartz crystal and the glass substrate. By controlling the height of the hydrofluoric acid solution, the epoxy resin glue is prevented from contacting the hydrofluoric acid, thereby solving the problem of glue corrosion failure. The expensive anti-corrosion glue mentioned in the literature [Ayman H. Said, Thomas Gog, Michael Wieczorek, XianRong Huang, Diego Casa, Elina Kasman, Ralu Divanb and Jung HoKim, High-energy-resolution diced spherical quartz analyzers for resonantinelastic X-ray scattering, J. Synchrotron Rad. (2018). 25, 373–377] is avoided, saving costs.

[0054] The quartz bent crystal monochromator of this embodiment uses this set of cutting parameters, and the cutting edge of the quartz is neat, the chipping edge is about 6~14μm, and the overall size is less than 15μm (see Figure 2 , Figure 3 ), and successfully obtained a crack-free quartz pixel flat crystal array with a length of 50 mm and a width of 25 mm (see Figure 4 ), avoiding the energy broadening caused by bending stress and realizing the preparation of large-size, high-resolution quartz bent crystal monochromator.

[0055] The quartz bent crystal monochromator of this embodiment is applied to an X-ray Rowland spectrometer or an X-ray absorption spectrometer, and can cover a wide range of Bragg angles and energy measurement ranges. The high energy resolution quartz bent crystal monochromator enables the spectrometer to obtain high-precision spectral data.

[0056] Comparative Example 1

[0057] The quartz curved crystal monochromator and its preparation method of this comparative example are basically the same as those of Example 1, except that step S2 is omitted, and the quartz containing thin walls is directly bonded to the concave borosilicate glass to realize the production of the spherical curved crystal.

[0058] In this comparative example, the residual thin wall also has stress inside when it is bent, and the stress will be transferred to the upper surface of the crystal, affecting the energy resolution.

[0059] Comparative Example 2

[0060] The quartz bent crystal monochromator and its preparation method of this comparative example are basically the same as those of Example 1, except that in step S1, a laser is used instead of a diamond dicing machine to groove the single crystal quartz wafer, the laser power is 30w, and the cutting speed is 1mm / s.

[0061] Single crystal quartz wafers can also be cut using laser grooving, but for quartz with a thickness greater than 2 mm, cracks are prone to appear, and the laser will be reflected to other areas at the cracks, making it impossible to penetrate the cracks and continue cutting.

[0062] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A method for preparing a quartz bent crystal monochromator, characterized in that: The following steps are involved: S1. Obtain backscattered diffraction spots using a Laue camera, compare with theoretical results to confirm that the crystal orientation is correct, fix a quartz single crystal material with a thickness of X on a blue film to obtain a single crystal quartz wafer, and groove the single crystal quartz wafer with a groove depth of Y to obtain a grooved single crystal quartz wafer; S2. The grooved surface of the grooved single crystal quartz wafer is bonded to the flat glass, and the grooved single crystal quartz wafer is etched away from the flat glass side to a thickness of XY to obtain a quartz array; S3. The quartz array is bent and bonded to the concave glass to obtain a quartz bent crystal monochromator; The edge collapse of the single crystal quartz in the quartz bent crystal monochromator is less than 15 μm.

2. The method for preparing a quartz bent crystal monochromator according to claim 1, characterized in that: In step S1, the process parameters of the grooving are: using a diamond dicing machine, the main shaft is a 1.5Kw AC shaft, the cutting speed is 0.3mm / s, the blade thickness is 0.5mm, the blade speed is 20000rpm, and the cutting depth is 400μm.

3. The method for preparing a quartz bent crystal monochromator according to claim 2, characterized in that: In step S1, the thickness of the single crystal quartz wafer is 2.5 mm and the diameter is 4 inches; the slotting method is a rectangular array with a spacing of 1 mm, and the slotting depth is 2.25 mm.

4. The method for preparing a quartz bent crystal monochromator according to claim 1, characterized in that: In step S2, epoxy resin glue is used for bonding, with a curing temperature of 85° C. and a curing time of 3 hours.

5. The method for preparing a quartz bent crystal monochromator according to claim 4, characterized in that: In step S2, hydrofluoric acid is used for etching; the concentration of the hydrofluoric acid is 40%wt.

6. The method for preparing a quartz bent crystal monochromator according to claim 1, characterized in that: The flat glass or concave glass is high borosilicate glass; the flat glass is 0.5 mm thick, the concave glass is 12 mm thick, and the curvature of the concave glass is 0.5 m to 2 m.

7. Quartz curved crystal monochromator, characterized in that: Prepared by the method according to any one of claims 1 to 6, comprising a quartz array bonded to a concave glass via a flat glass; the quartz array comprises a plurality of single crystal quartz bonded to the flat glass; The edge chipping of the single crystal quartz is less than 15 μm.

8. The quartz bent crystal monochromator according to claim 7, characterized in that: The quartz array is 50 mm long, 25 mm wide, and 2.25 mm high, and the interval between adjacent single crystal quartz is 1 mm.

9. The quartz bent crystal monochromator according to claim 8, characterized in that: The flat glass or concave glass is high borosilicate glass; the flat glass is 0.5 mm thick; the concave glass is 12 mm thick; and the curvature of the concave glass is 0.5 m to 2 m.

10. Application of quartz bent crystal monochromator, characterized by: The quartz bent crystal monochromator described in any one of claims 7 to 9 is applied to an X-ray Rowland spectrometer or an X-ray absorption spectrometer.

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