X-ray grating and method of manufacturing and use thereof

Abstract

The application provides an X-ray grating and a preparation method and application thereof, and the preparation method comprises the following steps: first, performing pattern modification on a substrate by using a laser; then, performing etching on the pattern-modified region to obtain a substrate with linear grooves and / or linear through holes; setting shielding material on the surface of the obtained substrate and in the linear grooves and / or linear through holes; and removing the shielding material on the surface of the substrate to obtain the X-ray grating. According to the preparation method, the substrate is modified by using a laser, and then etching is performed, so that the modified region is easy to be etched, the lateral etching is small, the linear grooves or linear through holes with high aspect ratio can be easily prepared, and thus the X-ray grating with high aspect ratio and high contrast can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of X-ray modulation and imaging technology, and relates to an X-ray grating, its preparation method and application. Background Technology

[0002] X-rays have strong penetrating power, and the intensity of absorption varies when they pass through objects of different densities and thicknesses. After imaging processing, different images can be obtained. Therefore, X-rays can be used for industrial flaw detection and medical diagnosis.

[0003] Traditional X-ray imaging techniques, which rely solely on the absorption of X-rays by objects, are limited in their ability to detect low-density and thin objects. However, X-ray imaging techniques based on micro-nano gratings have emerged, which can simultaneously detect the absorption, refraction, and dark fields generated by small-angle scattering of X-rays, resulting in higher accuracy.

[0004] Currently, gratings used for X-ray imaging are generally patterned micro / nano gratings formed by exposure and development. This method is similar to the process used in chip manufacturing, involving deep silicon etching of the wafer. However, this method requires sophisticated equipment, presents significant technical challenges, is costly, and requires overcoming the lateral etching problem during the deep silicon etching process. Furthermore, since X-rays are often point sources, gratings are typically designed as convex lens-like surfaces. However, the physical properties of wafers make it difficult to fabricate curved surfaces, and the limited wafer size prevents the fabrication of very large gratings.

[0005] Therefore, there is a need to improve the fabrication method of X-ray gratings. For example, CN116741430A discloses an X-ray grating and its fabrication method. The fabrication method includes the following steps: fabricating grating grooves or grating holes on a substrate; cleaning and drying the substrate; depositing an insulating film: covering the sidewalls and top surface of the grating structure with an insulating layer, exposing the bottom of the grating structure; preparing a suspension of metal nanoparticles; placing the metal structure in the suspension in a vacuum environment, opposite to a metal electrode, applying a voltage, and the metal nanoparticles in the suspension gather into the grating structure under the action of the electric field and deposit at the bottom of the grating structure until the grating grooves or grating holes are filled; cleaning the substrate surface. However, the substrate material used in this fabrication method is silicon crystal material, which is expensive, and the deep ion beam etching method used has a high threshold and complex process.

[0006] For example, CN108714625A discloses a novel X-ray grating fabrication process, which includes the following steps: S1: rolling a metal plate; S2: fabricating a composite film; S3: fabricating a composite film stack; S4: cutting; S5: encapsulation. Although the above method is one way to fabricate an X-ray grating, because it uses a metal film stacking method, the precision is not very high, and the grating size cannot reach the micrometer level.

[0007] Based on the above research, there is a need to provide a method for fabricating X-ray gratings. The fabrication method is simple and low in cost, and can produce X-ray gratings with a high aspect ratio. Summary of the Invention

[0008] The purpose of this invention is to provide an X-ray grating, its preparation method and application. The preparation method involves laser modification of the substrate followed by etching, which makes the modified area easy to etch, with minimal lateral etching, and facilitates the preparation of linear grooves or linear through-holes with high aspect ratio, thereby obtaining an X-ray grating with high aspect ratio and high contrast.

[0009] To achieve this objective, the present invention employs the following technical solution:

[0010] In a first aspect, the present invention provides a method for fabricating an X-ray grating, the method comprising the following steps:

[0011] (1) First, the substrate is patterned by laser, and then the patterned area is etched to obtain a substrate with linear grooves and / or linear through holes.

[0012] (2) The shielding material is placed on the substrate surface and in the linear groove and / or linear through hole obtained in step (1), and then the shielding material on the substrate surface is removed to obtain the X-ray grating.

[0013] This invention employs laser-modified etching to create linear grooves and / or linear vias in a substrate, serving as grating grooves and / or grating holes. Laser modification makes the modified areas easier to etch, meaning that areas excited by the laser are more readily reacted with the etching solution, and lateral etching is minimal, making it easy to fabricate X-ray gratings with high aspect ratios and high contrast. Then, a shielding material is filled into the substrate surface and the linear grooves and / or linear vias to form a shielding area. Finally, the shielding material on the substrate surface is removed, resulting in an X-ray grating with a high aspect ratio. Therefore, this invention not only enables the fabrication of X-ray gratings with high aspect ratios but also features a simple and low-cost fabrication method.

[0014] Preferably, the depth of the linear groove in step (1) is 0.4-1.5 mm, for example, it can be 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.5 mm, and the width is 5-100 μm, for example, it can be 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, and the depth-to-width ratio is 10-300, for example, it can be 10, 50, 100, 150, 200, 250 or 300, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] Preferably, the depth of the linear through hole in step (1) is 0.4-1.5 mm, for example, it can be 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.5 mm, and the width is 5-100 μm, for example, it can be 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, and the aspect ratio is 10-300, for example, it can be 10, 50, 100, 150, 200, 250 or 300, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the linear grooves described in step (1) are distributed in parallel or perpendicularly on the surface of the substrate.

[0017] Preferably, the linear through holes described in step (1) are distributed in parallel or perpendicularly on the surface of the substrate.

[0018] After etching, in the top view of the substrate, the linear grooves and / or linear through holes are distributed in parallel. When they are distributed vertically, the linear grooves intersect each other to form a grid, and the linear through holes are distributed in the same way.

[0019] Preferably, the linear groove in step (1) is rectangular or parallelogram-shaped in the cross-section of the substrate thickness direction.

[0020] Preferably, the linear through hole in step (1) is rectangular or parallelogram-shaped in the cross-section of the substrate thickness direction.

[0021] On the cross-section of the substrate described in this invention, the linear grooves and / or linear through holes are rectangular or parallelogram-shaped, that is, the linear grooves and / or linear through holes extend vertically or obliquely into the substrate. When they are parallelogram-shaped, the linear grooves are oblique linear grooves and the linear through holes are oblique linear through holes. The reason for preparing oblique linear grooves and / or linear through holes in this invention is that a sudden interruption of the grating at the edge will cause unnecessary scattering and reflection at the edge. Oblique linear through holes can reduce the edge effect of the grating, allowing light to pass smoothly through the grating surface and maintaining the continuity and uniformity of light.

[0022] When the linear groove and / or linear through hole of the present invention are parallelograms in the cross section of the substrate, the depth of the linear groove and / or linear through hole refers to the height of the parallelogram.

[0023] Preferably, the acute angles of the base angles of the parallelogram range from 60° to 89°, for example, 60°, 70°, 80° or 89°, but are not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] The angle of the acute angle at the bottom of the parallelogram formed by the linear groove and / or linear through hole on the cross section of the substrate should not be too large or too small. That is, the tilt angle of the linear groove and / or linear through hole should not be too large or too small. If the tilt angle is too large (i.e., the acute angle at the bottom of the parallelogram is too small), the gradient area will be too large and affect the contrast of light in different areas. If the tilt angle is too small (i.e., the acute angle at the bottom of the parallelogram is too large), the purpose of reducing scattering and reflection will not be achieved.

[0025] Preferably, the substrate in step (1) includes a glass substrate, and more preferably a lead-free glass substrate.

[0026] The preferred substrate of this invention is a glass substrate, specifically a lead-free glass substrate, rather than a silicon substrate. This reduces costs, overcomes the lateral etching problem in deep silicon etching, and addresses the limitation of wafer size in fabricating large-size X-ray gratings. In contrast, the glass substrate of this invention is not limited by size and can be used to fabricate large-size gratings. Furthermore, the glass substrate can be used to create complex curved shapes to optimize scattering.

[0027] Preferably, the laser in step (1) includes an infrared laser.

[0028] Preferably, the etching method in step (1) includes etching the patterned modified substrate with an alkaline etching solution.

[0029] Preferably, the pH of the alkaline etching solution is 13-14, for example, it can be 13, 13.5 or 14, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the etching temperature in step (1) is 90-95°C, for example, 90°C, 92°C, 94°C or 95°C, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] Preferably, after etching is completed in step (1), acid washing, water washing and drying steps are also performed.

[0032] Preferably, before performing step (2), the substrate obtained in step (1) is subjected to a hot bending process.

[0033] Depending on the actual needs, a hot bending process can be performed after etching to bend the substrate and form an arc-shaped surface.

[0034] Preferably, before setting the shielding material in step (2), a metal bonding layer is first set on the substrate surface and in the linear groove and / or linear through hole obtained in step (1).

[0035] Since the preferred substrate of this invention is a glass substrate, the bonding force between the glass substrate and the shielding material is limited. In order to improve the bonding strength between the glass substrate and the shielding material, it is preferable to first set a metal bonding layer (such as a transition metal) before setting the shielding material to enhance the bonding force between the glass substrate and the shielding material.

[0036] Preferably, the metal bonding layer is made of any one or a combination of at least two of nickel, chromium, or titanium.

[0037] Preferably, the thickness of the metal bonding layer is 50-60 nm, for example, it can be 50 nm, 55 nm or 60 nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the method for preparing the metal bonding layer includes vapor deposition and / or magnetron sputtering.

[0039] Preferably, the shielding material in step (2) includes heavy metals.

[0040] Preferably, the heavy metal includes any one or a combination of at least two of lead, bismuth, tungsten, gold, or platinum.

[0041] Preferably, the shielding material in step (2) fills the linear grooves and / or linear through holes in the substrate.

[0042] Preferably, the method of setting the shielding material in step (2) includes any one or a combination of at least two of PVD (physical vapor deposition), CVD (chemical vapor deposition), chemical coating, thermal spraying, or sol-gel method.

[0043] This invention employs PVD (physical vapor deposition), CVD (chemical vapor deposition), chemical coating, thermal spraying, or sol-gel method to place shielding materials in linear grooves and / or linear through holes. The process is simple and low-cost.

[0044] Preferably, the method of removing the shielding material from the substrate surface in step (2) includes polishing.

[0045] In a second aspect, the present invention provides an X-ray grating, which is prepared by the preparation method described in the first aspect.

[0046] Preferably, the X-ray grating includes a substrate, the substrate being divided into a penetration area and a shielding area, the shielding area including linear grooves and / or linear through holes, and shielding material filling the linear grooves and / or linear through holes.

[0047] Preferably, the depth of the linear groove is 0.4-1.5 mm, for example, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.5 mm; the width is 5-100 μm, for example, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm; and the aspect ratio is 10-300, for example, 10, 50, 100, 150, 200, 250 or 300, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] Preferably, the depth of the linear through hole is 0.4-1.5 mm, for example, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.5 mm; the width is 5-100 μm, for example, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm; and the aspect ratio is 10-300, for example, 10, 50, 100, 150, 200, 250 or 300, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0049] Thirdly, the present invention provides an application of an X-ray grating as described in the first aspect, the application including its use in the field of X-ray imaging.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] This invention employs laser-modified etching to create linear grooves and / or linear vias in a substrate, serving as grating grooves and / or grating holes. Laser modification makes the modified areas easier to etch, meaning that areas excited by the laser are more readily reacted with the etching solution, and lateral etching is minimal, making it easy to fabricate X-ray gratings with high aspect ratios and high contrast. Then, a shielding material is filled into the substrate surface and the linear grooves and / or linear vias to form a shielding area. Finally, the shielding material on the substrate surface is removed, resulting in an X-ray grating with a high aspect ratio. Therefore, this invention not only enables the fabrication of X-ray gratings with high aspect ratios but also features a simple and low-cost fabrication method. Attached Figure Description

[0052] Figure 1 This is a top view of the X-ray grating described in Embodiment 1 of the present invention;

[0053] Figure 2 This is a cross-sectional schematic diagram of the X-ray grating described in Embodiment 1 of the present invention;

[0054] Figure 3 This is a top view of the X-ray grating described in Embodiment 2 of the present invention;

[0055] Figure 4 This is a cross-sectional schematic diagram of the X-ray grating described in Embodiment 2 of the present invention;

[0056] Figure 5 This is a schematic cross-sectional view of the X-ray grating described in Embodiment 3 of the present invention;

[0057] Figure 6 This is a cross-sectional schematic diagram of the X-ray grating described in Embodiment 4 of the present invention;

[0058] Wherein, 1-base, 21-first linear groove, 22-second linear groove, 23-first linear through hole, 24-second linear through hole. Detailed Implementation

[0059] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0060] Example 1

[0061] This embodiment provides a method for fabricating an X-ray grating, the method comprising the following steps:

[0062] S1: Glass modification:

[0063] A picosecond-level infrared laser with a spot size of 5μm was used to pattern the 0.5mm thick quartz glass substrate, making the laser-excited areas more easily reacted by the etching solution.

[0064] S2: Etching:

[0065] The patterned glass was etched using an etching solution with a pH of 13.5 containing sodium hydroxide, EDTA-2Na (disodium ethylenediaminetetraacetate), TO-7 (isomeric alcohol ether), and a nonionic emulsifier (isomeric tridecyl alcohol polyoxyethylene ether). One side of the quartz glass was attached to a plastic substrate. The etching solution was ultrasonically controlled and kept at a temperature of 92°C. After etching for 60 minutes, a first linear groove with a depth of 0.4 mm and a width of 6 μm was obtained. After etching, the glass was acid-washed, rinsed with water, and dried.

[0066] S3: Hot bending:

[0067] The etched glass is curved using a hot bending mold. The glass is placed in the mold and heated to 600°C in the hot bending machine. After holding the temperature for 40 minutes, it is allowed to cool naturally to room temperature.

[0068] S4: Coating:

[0069] After the glass is cleaned, it is placed into the vapor deposition machine, and the air pressure in the vapor deposition machine is evacuated to 10. -5 The glass was subjected to plasma treatment at Pa, followed by nickel plating on the glass using an evaporation nickel target. The glass was then rotated, with the nickel deposition rate controlled at 0.5 nm / s and the nickel thickness at 10 nm. The plating was then annealed at 200 °C, cooled, and then placed into a chromium target. The pressure was then increased to 10 Pa. -5 Pa, heat the glass to 200°C, use an electron beam to excite the chromium target and rotate the glass, control the chromium deposition rate to 0.5 nm / s and the chromium thickness to 50 nm, turn off the evaporation source, after the glass cools, fill it with argon gas and heat it to 300°C for annealing, after cooling, put the glass into a flame spraying machine and heat it to 60°C, heat the lead material to make it liquid and spray it on the glass, stop spraying when the first linear groove on the glass is filled with lead material, and take out the glass after cooling;

[0070] S5: Polishing

[0071] The glass is placed in a polishing machine, and the metal on the glass surface is polished with 0.8mm cerium oxide polishing liquid. Once all the metal on the glass surface is removed, the X-ray grating with a high aspect ratio is obtained.

[0072] The top view of the X-ray grating described in this embodiment is as follows: Figure 1 As shown in the schematic cross-sectional view Figure 2 As shown, the X-ray grating includes a glass substrate 1 and a first linear groove 21. The first linear groove 21 is filled with the metal from step S4. The first linear grooves 21 are distributed in parallel on the surface of the glass substrate 1 and are rectangular in cross-section in the thickness direction of the glass substrate 1.

[0073] Example 2

[0074] This embodiment provides a method for fabricating an X-ray grating, the method comprising the following steps:

[0075] S1: Glass modification:

[0076] A picosecond-level infrared laser with a spot size of 10μm was used to pattern the quartz glass substrate with a thickness of 1.0mm, making the laser-excited areas more easily reacted by the etching solution.

[0077] S2: Etching:

[0078] The glass was etched using an etching solution with a pH of 13-14 containing sodium hydroxide, EDTA-2Na, TO-7, and a nonionic emulsifier (Span 60). One side of the quartz glass was attached to a plastic substrate. The ultrasonic etching was turned on and the temperature of the etching solution was kept at 90°C. After etching for 120 minutes, a second linear groove with a depth of 0.8 mm and a width of 12 μm was obtained. After etching, the glass was pickled, rinsed with water, and dried.

[0079] S3: Hot bending:

[0080] The etched glass is curved using a hot bending mold. The glass is placed in the mold and heated to 600°C in the hot bending machine. After holding the temperature for 40 minutes, it is allowed to cool naturally to room temperature.

[0081] S4: Coating:

[0082] After the glass is cleaned, it is placed into the vapor deposition machine, and the air pressure in the vapor deposition machine is evacuated to 10. -5 The glass was subjected to plasma treatment at 10 Pa, followed by nickel plating on a nickel target by evaporation and rotation. The nickel deposition rate was controlled at 0.1 nm / s, and the nickel thickness was 10 nm. The plating was then annealed at 200 °C. After cooling, a chromium target was installed, and the pressure was increased to 10 Pa. -5 Pa, heat the glass to 200℃, use an electron beam to excite the chromium target and rotate the glass, control the chromium deposition rate to 0.1nm / s, the chromium thickness to 50nm, turn off the evaporation source, after the glass cools, fill it with argon gas and heat it to 300℃ for annealing treatment, after cooling, put it into a chemical coating solution for tungsten plating, the concentration of sodium tungstate in the coating solution is 40g / L, the concentration of sodium phosphate is 40g / L, the concentration of EDTA is 10g / L, and the pH value is adjusted to 10 with ammonia water, the coating solution is stirred during coating, and it is taken out after the second linear groove is completely filled;

[0083] S5: Polishing

[0084] The glass is placed in a polishing machine, and the metal on the glass surface is polished using a 0.8mm cerium oxide polishing solution. Once all the metal on the glass surface is removed, a high aspect ratio X-ray grating is obtained.

[0085] The top view of the X-ray grating described in this embodiment is as follows: Figure 3 As shown in the schematic cross-sectional view Figure 4 As shown, the X-ray grating includes a glass substrate 1 and a second linear groove 22. The second linear groove 22 is filled with the metal from step S4. The second linear grooves 22 are vertically distributed (in a grid pattern) on the surface of the glass substrate 1 and form a parallelogram in the cross-section of the thickness direction of the glass substrate 1. The acute angle of the bottom of the parallelogram is 70°.

[0086] Example 3

[0087] This embodiment provides a method for fabricating an X-ray grating, the method comprising the following steps:

[0088] S1: Glass modification:

[0089] A picosecond-level infrared laser with a spot size of 10μm was used to pattern the quartz glass with a thickness of 1.5mm, making the laser-excited areas more easily reacted by the etching solution.

[0090] S2: Etching:

[0091] The patterned glass was etched using an etching solution with a pH of 14 containing sodium hydroxide, EDTA-2Na (disodium ethylenediaminetetraacetate), TO-7 (isomeric alcohol ether), and a nonionic emulsifier (cocoyl diethanolamide). The etching solution was ultrasonically controlled and kept at a temperature of 95°C. After etching for 120 minutes, a first linear through-hole with a depth of 1.5 mm and a width of 12 μm was obtained. After etching, the glass was then acid-washed, rinsed with water, and dried.

[0092] S3: Hot bending:

[0093] The etched glass is curved using a hot bending mold. The glass is placed in the mold and heated to 600°C in the hot bending machine. After holding the temperature for 40 minutes, it is allowed to cool naturally to room temperature.

[0094] S4: Coating:

[0095] The heat-bent glass is placed into a magnetron sputtering machine, and the vacuum chamber is evacuated to 10°C. -7 Torr, heat the glass to 200°C, use argon as the sputtering gas to sputter the titanium target at a sputtering power of 400W, and sputter 50nm titanium on the glass surface. After sputtering, perform deposition; heat high-purity bismuth to above the melting point under a protective gas, pour liquid bismuth onto the glass surface, scrape off the excess metallic bismuth on the surface with a scraper, and slowly cool to obtain a bismuth layer.

[0096] S5: Polishing

[0097] The glass is placed in a polishing machine, and the metal on the glass surface is polished on both sides using a 0.8mm cerium oxide polishing solution. Once all the metal on the glass surface is removed, a high aspect ratio X-ray grating is obtained.

[0098] A cross-sectional schematic diagram of the X-ray grating described in this embodiment is shown below. Figure 5 As shown, the X-ray grating includes a glass substrate 1 and a first linear through hole 23. The first linear through hole 23 is filled with the metal in step S4. The first linear through holes 23 are distributed in parallel on the surface of the glass substrate 1 and are rectangular in cross-section in the thickness direction of the glass substrate 1.

[0099] Example 4

[0100] This embodiment provides a method for fabricating an X-ray grating, the method comprising the following steps:

[0101] S1: Glass modification:

[0102] A picosecond-level infrared laser with a spot size of 10μm was used to pattern the quartz glass with a thickness of 1.5mm, making the laser-excited areas more easily reacted by the etching solution.

[0103] S2: Etching:

[0104] The patterned glass was etched using an etching solution with a pH of 14 containing sodium hydroxide, EDTA-2Na (disodium ethylenediaminetetraacetate), TO-7 (isomeric alcohol ether), and a nonionic emulsifier (Tween 80). The etching solution was ultrasonically controlled and kept at a temperature of 95°C. After etching for 120 minutes, a second linear through-hole with a depth of 1.5 mm and a width of 12 μm was obtained. After etching, the glass was then acid-washed, rinsed with water, and dried.

[0105] S3: Hot bending:

[0106] The etched glass is curved using a hot bending mold. The glass is placed in the mold and heated to 600°C in the hot bending machine. After holding the temperature for 40 minutes, it is allowed to cool naturally to room temperature.

[0107] S4: Coating:

[0108] The heat-bent glass is placed into a magnetron sputtering machine, and the vacuum chamber is evacuated to 10°C. -7 Torr, heat the glass to 200°C, use argon as the sputtering gas to sputter the titanium target, sputter power 400W, sputter 50nm titanium on the glass surface, and then deposit it; bismuth is surface modified with phthalate and dispersed in an active diluent, and then sprayed onto the glass surface by spraying, the active diluent is dried and remelted and crystallized at 300°C.

[0109] S5: Polishing

[0110] The glass is placed in a polishing machine, and the metal on the glass surface is polished on both sides using a 0.8mm cerium oxide polishing solution. Once all the metal on the glass surface is removed, a high aspect ratio X-ray grating is obtained.

[0111] A cross-sectional schematic diagram of the X-ray grating described in this embodiment is shown below. Figure 6 As shown, the X-ray grating includes a glass substrate 1 and a second linear through-hole 24. The second linear through-hole 24 is filled with the metal from step S4. The second linear through-holes 24 are distributed in parallel on the surface of the glass substrate 1 and form a parallelogram in the cross-section of the thickness direction of the glass substrate 1. The acute angle of the bottom of the parallelogram is 85°.

[0112] Example 5

[0113] This embodiment provides a method for fabricating an X-ray grating, which is the same as in Embodiment 1 except that the quartz glass substrate is replaced with a silicon substrate.

[0114] Example 6

[0115] This embodiment provides a method for fabricating an X-ray grating. The method is the same as in Embodiment 1, except that the linear groove is a parallelogram in the cross-section of the glass substrate in the thickness direction and the acute angle of the bottom of the parallelogram is 70°.

[0116] Example 7

[0117] This embodiment provides a method for fabricating an X-ray grating. The method is the same as in Embodiment 1, except that the linear groove is a parallelogram in the cross-section of the glass substrate in the thickness direction and the acute angle at the bottom of the parallelogram is 50°.

[0118] Example 8

[0119] This embodiment provides a method for fabricating an X-ray grating. The method is the same as in Embodiment 1, except that the linear groove is a parallelogram in the cross-section of the glass substrate in the thickness direction and the acute angle at the bottom of the parallelogram is 40°.

[0120] Example 9

[0121] This embodiment provides a method for preparing an X-ray grating. The preparation method is the same as in Embodiment 1, except that in step S4, nickel is not evaporated and chromium is deposited, but lead is directly sprayed.

[0122] Comparative Example 1

[0123] This embodiment provides a method for preparing an X-ray grating. The preparation method is the same as that in Embodiment 1, except that the glass modification step in step S1 is not performed.

[0124] The depth and width of the linear grooves or through-holes in the X-ray gratings obtained in the above embodiments and comparative examples are shown in Table 1. The contrast of the shielded area and the penetrating area outside the shielded area of ​​the X-ray gratings obtained in the above embodiments and comparative examples was tested. The test method was to irradiate the shielded area and the penetrating area with 30 keV X-rays respectively, and then test the X-ray intensity of the penetrating shielded area and the penetrating area respectively using an X-ray detector. The test results are shown in Table 1.

[0125] Table 1

[0126]

[0127] As can be seen from Table 1:

[0128] As shown in Example 1 and Comparative Example 1, the present invention uses laser modification to make the modified area easy to etch and with small lateral etching, which is beneficial for the preparation of X-ray gratings with high aspect ratio and high contrast. As shown in Example 1 and Example 5, the present invention preferably uses a glass substrate, which is not only low in cost and has small lateral etching, but also has no size limitation, which is beneficial for the preparation of large-size gratings, and the resulting X-ray gratings have excellent performance. As shown in Example 1 and Examples 6-8, the inclination angle of the linear grooves or linear through holes in the present invention should not be too large, that is, if the bottom acute angle of the parallelogram is too small, it will affect the performance of the X-ray grating. As shown in Example 1 and Example 9, before setting the shielding material in the linear grooves or linear through holes, the present invention first sets a metal bonding layer, such as the nickel and chromium first vapor-deposited in Example 1, which can improve the bonding force between the shielding material and the glass substrate, thereby improving the performance of the X-ray grating.

[0129] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for fabricating an X-ray grating, characterized in that, The preparation method includes the following steps: (1) First, the substrate is patterned by laser, and then the patterned area is etched to obtain a substrate with linear grooves and / or linear through holes. (2) The shielding material is placed on the substrate surface and in the linear groove and / or linear through hole obtained in step (1), and then the shielding material on the substrate surface is removed to obtain the X-ray grating.

2. The preparation method according to claim 1, characterized in that, The depth of the linear groove in step (1) is 0.4-1.5 mm, the width is 5-100 μm, and the depth-to-width ratio is 10-300; Preferably, the depth of the linear through hole in step (1) is 0.4-1.5 mm, the width is 5-100 μm, and the aspect ratio is 4-300.

3. The preparation method according to claim 1 or 2, characterized in that, The linear grooves described in step (1) are distributed in parallel or perpendicular directions on the surface of the substrate; Preferably, the linear through holes described in step (1) are distributed in parallel or perpendicularly on the surface of the substrate.

4. The preparation method according to any one of claims 1-3, characterized in that, The linear groove described in step (1) is rectangular or parallelogram-shaped in the cross-section of the base thickness direction; Preferably, the linear through hole described in step (1) is rectangular or parallelogram-shaped in the cross-section of the substrate thickness direction; Preferably, the acute angles of the base angles of the parallelogram range from 60° to 89°.

5. The preparation method according to any one of claims 1-4, characterized in that, The substrate in step (1) includes a glass substrate, preferably a lead-free glass substrate; Preferably, the laser in step (1) includes an infrared laser; Preferably, the etching method in step (1) includes etching the patterned modified substrate with an alkaline etching solution.

6. The preparation method according to any one of claims 1-5, characterized in that, Before proceeding to step (2), the substrate obtained in step (1) is subjected to a hot bending process. Preferably, before setting the shielding material in step (2), a metal bonding layer is first set on the substrate surface and in the linear groove and / or linear through hole obtained in step (1); Preferably, the material of the metal bonding layer includes any one or a combination of at least two of nickel, chromium, or titanium; Preferably, the thickness of the metal bonding layer is 50-60 nm; Preferably, the method for preparing the metal bonding layer includes vapor deposition and / or magnetron sputtering.

7. The preparation method according to any one of claims 1-6, characterized in that, The shielding material mentioned in step (2) includes heavy metals; Preferably, the heavy metal includes any one or a combination of at least two of lead, bismuth, tungsten, gold, or platinum; Preferably, the shielding material in step (2) fills the linear grooves and / or linear through holes in the substrate; Preferably, the method of setting the shielding material in step (2) includes any one or a combination of at least two of PVD, CVD, chemical coating, thermal spraying or sol-gel method; Preferably, the method of removing the shielding material from the substrate surface in step (2) includes polishing.

8. An X-ray grating, characterized in that, The X-ray grating is prepared by the preparation method according to any one of claims 1-7.

9. The X-ray grating according to claim 8, characterized in that, The X-ray grating includes a substrate, which is divided into a penetration area and a shielding area. The shielding area includes linear grooves and / or linear through holes, and shielding material filling the linear grooves and / or linear through holes. Preferably, the depth of the linear groove is 0.4-1.5 mm, the width is 5-100 μm, and the aspect ratio is 10-300; Preferably, the depth of the linear through hole is 0.4-1.5 mm, the width is 5-100 μm, and the aspect ratio is 10-300.

10. An application of the X-ray grating as described in claim 8 or 9, characterized in that, The applications include those used in the field of X-ray imaging.

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