Method for detecting grain size of tungsten target material

Abstract

The invention provides a method for detecting the grain size of a tungsten target material. The detection method comprises the following steps: (1) carrying out first grinding and polishing treatment and second grinding and polishing treatment on a to-be-detected area of a tungsten target material to obtain a detected surface; (2) performing circumferential sealing and enclosing treatment on the detection surface to form a sealed detection chamber, then injecting etching liquid into the sealed detection chamber to perform etching treatment, and performing cleaning treatment and drying treatment to obtain a detection sample; the etching liquid comprises nitric acid, hydrofluoric acid and sulfuric acid; and (3) observing the metallographic structure of the detection sample by using a portable microscope. The tungsten target material with a smooth and flat interface can be obtained through simple grinding and polishing treatment, a crystal boundary diagram obtained after etching treatment is clear, and the grain size of the tungsten target can be conveniently detected; according to the detection method, different areas of the target material can be detected for multiple times, the overall uniformity of the target material can be effectively known, and local abnormal products are prevented from flowing into clients.

Description

Technical Field

[0001] This invention belongs to the field of target material processing and testing technology, and particularly relates to a method for detecting the grain size of tungsten target materials. Background Technology

[0002] The internal microstructure of metallic materials directly determines their mechanical properties, physical properties, and reliability. Among these, grains, as the basic building blocks of metallic materials, have a significant impact on their overall properties, including strength, toughness, and electrical conductivity, due to their size, morphology, and uniformity. Industrial practice shows that finer and more uniform grains result in superior fatigue resistance, wear resistance, and processing stability. Tungsten sputtering targets, as core components in magnetron sputtering processes in semiconductors and photovoltaics, directly affect the uniformity of their grain structure, impacting thin film deposition quality, sputtering rate stability, and device lifespan.

[0003] To achieve visual inspection of grain structure, metallographic etching is currently the most commonly used technique. Its principle involves selectively etching the metal surface with chemical reagents, creating a light-dark contrast between the grain boundaries and the grain mass, thus allowing observation of grain morphology using a microscope. Targeting the characteristics of tungsten targets, CN 107322466A discloses a mirror-polishing method for tungsten targets and its application. Specifically, it discloses sequential chemical mechanical grinding and chemical mechanical polishing treatments, and further discloses an immersion etching treatment using hydrogen peroxide and ammonia in a volume ratio of 2.5~3.5:1 for 5~6 minutes, used for detecting the grain uniformity of tungsten targets.

[0004] However, existing tungsten sputtering target grain detection technologies still have significant drawbacks: current methods are all based on "small sample testing," requiring the cutting of a portion of material from the finished target to prepare a sample. The testing object is an independent sample detached from the finished product, rather than the finished target itself. This testing mode leads to two key problems: First, small samples cannot fully reflect the overall grain distribution characteristics of the finished target. Especially for large-sized, complex-structured tungsten targets, abnormal grain growth or unevenness may occur in local areas (such as edges, welds, and stress concentration areas), and small sample testing cannot cover these specific areas. Second, it is impossible to perform targeted grain analysis on abnormal areas such as surface defects and performance fluctuations that occur during the production, storage, or use of the finished target. This results in potential quality problems not being identified in a timely manner. For example, in the semiconductor industry, local grain abnormalities in the target may lead to uneven sputtered film thickness, thereby causing device failure.

[0005] As advanced manufacturing industries continuously raise the performance requirements for tungsten sputtering targets (such as the stringent requirements for sputtering target purity and grain uniformity due to the continuous shrinking of semiconductor process nodes), existing testing technologies that can only be used for small samples are no longer sufficient to meet the quality control needs of finished products. The market urgently needs a method that can directly test finished tungsten sputtering targets, especially one that can accurately locate and detect abnormal areas or key observation areas, thereby bridging the gap between small-sample testing and actual application scenarios and ensuring the reliability and stability of sputtering target products. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method for detecting the grain size of tungsten target materials. This invention achieves a smooth and flat tungsten target material through simple grinding and polishing, and obtains a clear grain boundary map after etching, facilitating the detection of tungsten target grain size. Furthermore, the detection method described in this invention can repeatedly test different areas of the target material, effectively understanding the overall uniformity of the target material and preventing products with localized anomalies from reaching the customer.

[0007] To achieve this objective, the present invention adopts the following technical solution: This invention provides a method for detecting the grain size of tungsten sputtering targets, the method comprising the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain the test surface; (2) The detection surface is circumferentially sealed to form a sealed detection chamber, and then an etching solution is injected into the sealed detection chamber for etching treatment. After cleaning and drying treatment, the detection sample is obtained. The etching solution includes nitric acid, hydrofluoric acid, and sulfuric acid; (3) The metallographic structure of the test sample was observed using a portable microscope.

[0008] The present invention utilizes two consecutive grinding and polishing processes to make the surface of the area to be tested shiny and free of scratches. If only the first grinding and polishing process is performed, the roughness of the area to be tested is relatively large. If the etching process is performed directly, the uneven surface will result in different etching effects. At the same time, the uneven surface is not conducive to focusing of the scanning electron microscope, which will affect the observation of grain size under the scanning electron microscope. In addition, the etching treatment described in this invention is carried out using a mixed solution of nitric acid, hydrofluoric acid and sulfuric acid. Nitric acid can react with tungsten target material to undergo redox reaction, hydrofluoric acid can effectively remove oxide scale and passivation film, and sulfuric acid adjusts solution viscosity, ionic strength and stability of reaction intermediates. The detection method provided by this invention is easy to operate, can detect different areas of the target material multiple times, can effectively understand the overall uniformity of the target material, and prevent products with local abnormalities from flowing to the customer; it has the prospect of large-scale industrial application.

[0009] As a preferred technical solution of the present invention, the sandpaper used in the first grinding and polishing process in step (1) is 160~200 mesh, for example, it can be 160 mesh, 170 mesh, 180 mesh, 190 mesh or 200 mesh, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0010] Preferably, the rotation speed of the first grinding and polishing process in step (1) is 1000~-3000 r / min, for example, it can be 1000 r / min, 1400 r / min, 1800 r / min, 2200 r / min, 2600 r / min or 3000 r / min, etc., but is not limited to the listed values. Other values ​​not listed in the range are also applicable.

[0011] Preferably, the time for the first grinding and polishing process in step (1) is 15 to 25 minutes, for example, it can be 15 minutes, 17 minutes, 19 minutes, 21 minutes, 23 minutes or 25 minutes, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] Preferably, in step (1), the roughness Ra of the area to be tested after the first grinding and polishing treatment is ≤10μm, for example, it can be 10μm, 9μm, 8μm, 7μm or 6μm, etc., but is not limited to the listed values. Other unlisted values ​​within the value range are also applicable.

[0013] As a preferred technical solution of the present invention, the sandpaper used in the second grinding and polishing process in step (1) is 300~350 mesh, for example, it can be 300 mesh, 310 mesh, 320 mesh, 330 mesh, 340 mesh or 350 mesh, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] Preferably, the rotation speed of the second grinding and polishing process in step (1) is 1000~3000 r / min, for example, it can be 1000 r / min, 1400 r / min, 1800 r / min, 2200 r / min, 2600 r / min or 3000 r / min, etc., but is not limited to the listed values. Other values ​​not listed in the range are also applicable.

[0015] Preferably, the time for the second grinding and polishing process in step (1) is 15 to 25 minutes, for example, it can be 15 minutes, 17 minutes, 19 minutes, 21 minutes, 23 minutes or 25 minutes, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the roughness Ra of the area to be tested after the second grinding and polishing treatment in step (1) is ≤5μm, for example, it can be 5μm, 4.8μm, 4.6μm, 4.4μm, 4.2μm or 4μm, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] As a preferred technical solution of the present invention, the fixture used for the circumferential sealing and enclosure treatment in step (2) includes any one of a sealing ring, a sealing tape, or a vacuum adsorption ring.

[0018] Preferably, the sealing ring is fixed to the detection surface by adhesive.

[0019] As a preferred technical solution of the present invention, the circumferential sealing and enclosure process in step (2) further includes edge grinding.

[0020] Preferably, the edge polishing process takes 50 to 60 minutes, for example, 50 minutes, 52 minutes, 54 minutes, 56 minutes, 58 minutes or 60 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] Preferably, the tool used for the edge polishing process includes a pneumatic polisher.

[0022] Preferably, the height of the sealed detection chamber in step (2) is 0.5~5mm, for example, it can be 0.5mm, 1mm, 2mm, 3mm, 4mm or 5mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] The present invention utilizes a fixture to achieve a sealed enclosure of the test surface, preventing leakage of the etching solution during the etching process and ensuring sufficient reaction between the etching solution and the test surface, thereby making it more conducive to detecting the size of tungsten target grains.

[0024] As a preferred technical solution of the present invention, the volume ratio of nitric acid, hydrofluoric acid and sulfuric acid in the etching solution in step (2) is (4.5~5.5):(4.5~5.5):1, for example, it can be 5:5:1, 4.5:4.5:1, 5.5:5.5:1, 4.5:5:1, 5:4.5:1, 4.8:5.2:1 or 5.2:4.8:1, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the concentration of the nitric acid is 65~68wt%, for example, it can be 65wt%, 65.5wt%, 66wt%, 66.5wt%, 67wt%, 67.5wt%, or 68wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the concentration of the hydrofluoric acid is 40-45 wt%, for example, it can be 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, or 45 wt%, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] Preferably, the concentration of the sulfuric acid is 95-98 wt%, for example, it can be 95 wt%, 95.5 wt%, 96 wt%, 96.5 wt%, 97 wt%, 97.5 wt%, or 98 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] As a preferred technical solution of the present invention, the temperature of the etching treatment in step (2) is 24~28℃, for example, it can be 24℃, 25℃, 26℃, 27℃ or 28℃, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the etching time in step (2) is 35~45s, for example, it can be 35s, 37s, 39s, 41s, 43s or 45s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the cleaning process in step (2) includes rinsing with deionized water.

[0031] As a preferred embodiment of the present invention, the method for detecting the grain size of tungsten target material provided by the present invention includes the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain a test surface with a roughness Ra≤5μm; The sandpaper used in the first grinding and polishing process is 160-200 mesh, the rotation speed is 1000-3000 r / min, and the time is 15-25 min. The second grinding and polishing process uses sandpaper with a grit of 300-350, a rotation speed of 1000-3000 r / min, and a time of 15-25 min; (2) The detection surface is circumferentially sealed to form a sealed detection chamber with a height of 0.5~5mm. Then, an etching solution is injected into the sealed detection chamber for etching treatment. After rinsing with deionized water and drying, the detection sample is obtained. The etching solution comprises nitric acid, hydrofluoric acid, and sulfuric acid in a volume ratio of (4.5~5.5):(4.5~5.5):1; the concentration of nitric acid is 65~68wt%, the concentration of hydrofluoric acid is 40~45wt%, and the concentration of sulfuric acid is 95~98wt%. The etching process is performed at a temperature of 24-28°C for 35-45 seconds. (3) The metallographic structure of the test sample was observed using a portable microscope.

[0032] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0033] Compared with the prior art, the present invention has the following beneficial effects: (1) The detection method provided by the present invention is easy to operate and can detect different areas of the target material multiple times. It can effectively understand the overall uniformity of the target material and prevent products with local abnormalities from flowing into the customer. It has the prospect of large-scale industrial promotion and application. (2) The present invention can obtain a smooth and flat tungsten target material through simple grinding and polishing treatment, and obtain a clear grain boundary diagram after etching treatment, which is convenient for detecting the grain size of tungsten target. (3) The present invention utilizes a fixture to achieve a sealed enclosure of the test surface, which avoids leakage of the etching solution during the etching process and ensures that the etching solution reacts fully with the test surface, thereby making it more conducive to detecting the size of tungsten target grains. Attached Figure Description

[0034] Figure 1 This is an image of the test sample provided in Embodiment 1 of the present invention, magnified 200 times under an electron microscope; Figure 2 This is an image of the test sample provided in Embodiment 2 of the present invention, magnified 200 times under an electron microscope; Figure 3 This is an image of the test sample provided in Embodiment 3 of the present invention, magnified 200 times under an electron microscope; Figure 4 This is a 200x magnified image of the test sample provided in Embodiment 4 of the present invention under an electron microscope; Figure 5 The image shown is a 200x magnified electron microscope image of the test sample provided in Embodiment 5 of the present invention. Figure 6This is an image of the test sample provided in Embodiment 6 of the present invention, magnified 200 times under an electron microscope; Figure 7 This is an image of the test sample provided in Embodiment 7 of the present invention, magnified 200 times under an electron microscope; Figure 8 This is an image of the test sample provided in Embodiment 8 of the present invention, magnified 200 times under an electron microscope; Figure 9 This is an image of the test sample provided in Embodiment 9 of the present invention, magnified 200 times under an electron microscope; Figure 10 This is a 200x magnified image of the test sample provided in Comparative Example 1 of the present invention under an electron microscope; Figure 11 This is a 200x magnified image of the test sample provided in Comparative Example 2 of the present invention under an electron microscope; Figure 12 This is a 200x magnified image of the test sample provided in Comparative Example 3 of the present invention under an electron microscope; Figure 13 This is a 200x magnified image of the test sample provided in Comparative Example 4 of the present invention under an electron microscope; Figure 14 This is a 200x magnified image of the test sample provided in Comparative Example 5 of the present invention under an electron microscope; Figure 15 This is a 200x magnified image of the test sample provided in Comparative Example 6 of the present invention under an electron microscope; Figure 16 This is a 200x magnified image of the test sample provided in Comparative Example 7 of this invention under an electron microscope. Detailed Implementation

[0035] 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.

[0036] Example 1 This embodiment provides a method for detecting the grain size of tungsten sputtering targets, the method comprising the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain a test surface with a roughness Ra≤5μm; The sandpaper used in the first grinding and polishing process is 180 mesh, the rotation speed is 2000 r / min, and the time is 20 min. The second grinding and polishing process uses 320-grit sandpaper, rotates at 2000 r / min, and lasts for 20 min. (2) After the detection surface is circumferentially sealed and the edges are ground, a sealed detection chamber with a height of 3mm is formed. Then, an etching solution is injected into the sealed detection chamber for etching treatment. After rinsing with deionized water and drying, the detection sample is obtained. The fixture used for the circumferential sealing and enclosure process is a sealing ring; the sealing ring is fixed to the detection surface with adhesive; the edge grinding process takes 60 minutes. The etching solution comprises nitric acid, hydrofluoric acid, and sulfuric acid in a volume ratio of 5:5:1; the concentration of nitric acid is 66.5 wt%, the concentration of hydrofluoric acid is 42.5 wt%, and the concentration of sulfuric acid is 96.5 wt%. The etching process was performed at a temperature of 26°C for 40 seconds. (3) The metallographic structure of the test sample was observed using a portable microscope.

[0037] The metallographic structure described in this embodiment is as follows: Figure 1 As shown.

[0038] Example 2 This embodiment provides a method for detecting the grain size of tungsten sputtering targets, the method comprising the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain a test surface with a roughness Ra≤5μm; The sandpaper used in the first grinding and polishing process is 160 mesh, the rotation speed is 1000 r / min, and the time is 25 min. The second grinding and polishing process uses 300-grit sandpaper, rotates at 1000 r / min, and lasts for 25 minutes. (2) The detection surface is subjected to circumferential sealing and edge grinding to form a sealed detection chamber with a height of 0.5 mm. Then, an etching solution is injected into the sealed detection chamber for etching treatment. After rinsing with deionized water and drying, the detection sample is obtained. The fixture used for the circumferential sealing and enclosure treatment is a sealant; the edge grinding treatment time is 55 minutes. The etching solution comprises nitric acid, hydrofluoric acid, and sulfuric acid in a volume ratio of 4.5:5.5:1; the concentration of nitric acid is 65 wt%, the concentration of hydrofluoric acid is 40 wt%, and the concentration of sulfuric acid is 95 wt%. The etching process was performed at a temperature of 26°C for 35 seconds. (3) The metallographic structure of the test sample was observed using a portable microscope.

[0039] The metallographic structure described in this embodiment is as follows: Figure 2 As shown.

[0040] Example 3 This embodiment provides a method for detecting the grain size of tungsten sputtering targets, the method comprising the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain a test surface with a roughness Ra≤5μm; The sandpaper used in the first grinding and polishing process is 200 mesh, the rotation speed is 3000 r / min, and the time is 15 min. The second grinding and polishing process uses 350-grit sandpaper, rotates at 3000 r / min, and lasts for 15 minutes. (2) The detection surface is subjected to circumferential sealing and edge grinding to form a sealed detection chamber with a height of 5mm. Then, an etching solution is injected into the sealed detection chamber for etching treatment. After rinsing with deionized water and drying, the detection sample is obtained. The fixture used for the circumferential sealing and enclosure treatment is a vacuum adsorption ring; the edge grinding treatment time is 50 minutes. The etching solution comprises nitric acid, hydrofluoric acid, and sulfuric acid in a volume ratio of 5.5:4.5:1; the concentration of nitric acid is 68 wt%, the concentration of hydrofluoric acid is 45 wt%, and the concentration of sulfuric acid is 98 wt%. The etching process was performed at a temperature of 26°C for 45 seconds. (3) The metallographic structure of the test sample was observed using a portable microscope.

[0041] The metallographic structure described in this embodiment is as follows: Figure 3 As shown.

[0042] Example 4 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the volume ratio of nitric acid, hydrofluoric acid, and sulfuric acid in the etching solution is adjusted to 6:5:1.

[0043] The metallographic structure described in this embodiment is as follows: Figure 4 As shown.

[0044] Example 5 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the volume ratio of nitric acid, hydrofluoric acid, and sulfuric acid in the etching solution is adjusted to 4:5:1.

[0045] The metallographic structure described in this embodiment is as follows: Figure 5 As shown.

[0046] Example 6 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the volume ratio of nitric acid, hydrofluoric acid, and sulfuric acid in the etching solution is adjusted to 5:6:1.

[0047] The metallographic structure described in this embodiment is as follows: Figure 6 As shown.

[0048] Example 7 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the volume ratio of nitric acid, hydrofluoric acid, and sulfuric acid in the etching solution is adjusted to 5:4:1.

[0049] The metallographic structure described in this embodiment is as follows: Figure 7 As shown.

[0050] Example 8 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the etching process time is adjusted to 30 seconds.

[0051] The metallographic structure described in this embodiment is as follows: Figure 8 As shown.

[0052] Example 9 This embodiment provides a method for detecting the grain size of tungsten target material. The only difference between this method and that of Embodiment 1 is that: In this embodiment, the etching process time is adjusted to 60 seconds.

[0053] The metallographic structure described in this embodiment is as follows: Figure 9 As shown.

[0054] Comparative Example 1 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: In this comparative example, the etching solution was adjusted to a volume ratio of hydrogen peroxide and ammonia of 3:1, and the etching time was adjusted to 5 minutes.

[0055] The metallographic structure described in this comparative example is as follows: Figure 10 As shown.

[0056] Comparative Example 2 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: In this comparative example, the etching solution was adjusted to a volume ratio of 1:1 of nitric acid and hydrofluoric acid.

[0057] The metallographic structure described in this comparative example is as follows: Figure 11 As shown.

[0058] Comparative Example 3 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: In this comparative example, the etching solution was adjusted to a volume ratio of hydrofluoric acid and sulfuric acid of 5:1.

[0059] The metallographic structure described in this comparative example is as follows: Figure 12 As shown.

[0060] Comparative Example 4 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: In this comparative example, the etching solution was adjusted to a volume ratio of 5:1 of nitric acid and sulfuric acid.

[0061] The metallographic structure described in this comparative example is as follows: Figure 13 As shown.

[0062] Comparative Example 5 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: This comparative example omits the circumferential sealing and enclosure process described in step (2).

[0063] The metallographic structure described in this comparative example is as follows: Figure 14 As shown.

[0064] Comparative Example 6 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: This comparative example undergoes a third grinding and polishing process after the second grinding and polishing process; the third grinding and polishing process uses 500-grit sandpaper and takes 20 minutes.

[0065] The metallographic structure described in this comparative example is as follows: Figure 15 As shown.

[0066] Comparative Example 7 This comparative example provides a method for detecting the grain size of tungsten target material. The only difference between this method and Example 1 is that: This comparative example adjusts step (1) to: mechanical polishing and chemical polishing performed sequentially; the polishing fluid used for chemical polishing is diamond polishing fluid; and the abrasive used for the polishing pad is diamond.

[0067] The metallographic structure described in this comparative example is as follows: Figure 16 As shown.

[0068] Test example: The surface roughness and metallographic structure diagrams of the test surfaces provided in the above embodiments and comparative examples were analyzed, and based on... Figures 1-16 The following points can be observed: (1) Comprehensive analysis of Examples 1-3 shows that the detection method provided by the present invention can obtain a smooth and flat tungsten target material through simple grinding and polishing. After etching, the grain boundary diagram is clear, which is convenient for detecting the grain size of the tungsten target. (2) Comprehensive analysis of Examples 1, 4-7 and Comparative Examples 1-4 shows that the selection of the composition and volume ratio parameters of the etching solution will affect the clarity of the grains after etching; If the nitric acid content in the etching solution is too low, the grains will not be fully visible; if the content is too high, the product will be over-etched. If the use of nitric acid is omitted, the grains will not be visible at all. If the hydrofluoric acid content in the etching solution is too low, the grains will not be fully displayed; if the content is too high, the product will be over-etched. If the use of hydrofluoric acid is omitted, the grains will not be displayed at all. Omitting the use of sulfuric acid in the etching solution will result in incomplete grain display. (3) Comprehensive analysis of Examples 1 and 8-9 shows that the etching time affects the clarity of the grains after etching; if the etching time is too short, the grains will not be fully displayed, and if the time is too long, the product will be over-etched. (4) A comprehensive analysis of Example 1 and Comparative Example 5 shows that omitting the circumferential sealing enclosure treatment will result in differences in the density of the overall grains; (5) A comprehensive analysis of Example 1 and Comparative Examples 6-7 shows that the processing of the area to be detected will affect the interface roughness, thereby affecting the detection effect; Adding a third grinding and polishing process would result in a lower surface roughness, but the grain appearance after etching would be basically the same as the etching effect after the second grinding and polishing process, so there is no need to add a third grinding and polishing process. If the grinding and polishing process is changed to chemical polishing, the surface roughness will be basically the same, and the grain appearance after corrosion will be basically the same as the corrosion effect after grinding and polishing. Therefore, there is no need to add chemical polishing, which increases the use of chemicals and consumables and increases costs.

[0069] In summary, the present invention can obtain a tungsten target with a smooth and flat interface through simple grinding and polishing. After etching, a clear grain boundary map is obtained, which is convenient for detecting the grain size of the tungsten target. Moreover, the detection method described in the present invention can detect different areas of the target multiple times, which can effectively understand the overall uniformity of the target and prevent products with local abnormalities from flowing to the customer.

[0070] The applicant declares that 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 detecting the grain size of tungsten sputtering targets, characterized in that, The detection method includes the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain the test surface; (2) The detection surface is circumferentially sealed to form a sealed detection chamber, and then an etching solution is injected into the sealed detection chamber for etching treatment. After cleaning and drying treatment, the detection sample is obtained. The etching solution includes nitric acid, hydrofluoric acid, and sulfuric acid; (3) The metallographic structure of the test sample was observed using a portable microscope.

2. The detection method according to claim 1, characterized in that, Step (1) The sandpaper used for the first grinding and polishing process is 160~200 mesh; Preferably, the rotation speed of the first grinding and polishing process in step (1) is 1000~3000 r / min; Preferably, the time for the first grinding and polishing process in step (1) is 15~25 min; Preferably, in step (1), the roughness Ra of the area to be tested after the first grinding and polishing treatment is ≤10μm.

3. The detection method according to claim 1 or 2, characterized in that, Step (1) The sandpaper used for the second grinding and polishing process is 300~350 mesh; Preferably, the rotation speed of the second grinding and polishing process in step (1) is 1000~3000 r / min; Preferably, the time for the second grinding and polishing process in step (1) is 15~25 min; Preferably, the roughness Ra of the area to be tested after the second grinding and polishing treatment in step (1) is ≤5μm.

4. The detection method according to any one of claims 1-3, characterized in that, The fixture used for the circumferential sealing and enclosure process in step (2) includes any one of a sealing ring, sealing tape, or vacuum adsorption ring; Preferably, the sealing ring is fixed to the detection surface by adhesive.

5. The detection method according to claim 1, characterized in that, Step (2) after the circumferential sealing and enclosure treatment also includes edge grinding treatment; Preferably, the edge polishing process takes 50-60 minutes; Preferably, the height of the sealed detection chamber in step (2) is 0.5~5mm.

6. The detection method according to any one of claims 1-5, characterized in that, The volume ratio of nitric acid, hydrofluoric acid and sulfuric acid in the etching solution in step (2) is (4.5~5.5):(4.5~5.5):

1.

7. The detection method according to claim 6, characterized in that, The concentration of the nitric acid is 65-68 wt%; Preferably, the concentration of the hydrofluoric acid is 40-45 wt%. Preferably, the concentration of the sulfuric acid is 95-98 wt%.

8. The detection method according to any one of claims 1-7, characterized in that, The etching temperature in step (2) is 24~28℃; Preferably, the etching process in step (2) takes 35 to 45 seconds.

9. The detection method according to any one of claims 1-8, characterized in that, The cleaning process in step (2) includes rinsing with deionized water.

10. The detection method according to any one of claims 1-9, characterized in that, The detection method includes the following steps: (1) Perform a first grinding and polishing treatment and a second grinding and polishing treatment on the area to be tested of the tungsten target to obtain a test surface with a roughness Ra≤5; The sandpaper used in the first grinding and polishing process is 160-200 mesh, the rotation speed is 1000-3000 r / min, and the time is 15-25 min. The second grinding and polishing process uses sandpaper with a grit of 300-350, a rotation speed of 1000-3000 r / min, and a time of 15-25 min; (2) The detection surface is circumferentially sealed to form a sealed detection chamber with a height of 0.5~5mm. Then, an etching solution is injected into the sealed detection chamber for etching treatment. After rinsing with deionized water and drying, the detection sample is obtained. The etching solution comprises nitric acid, hydrofluoric acid, and sulfuric acid in a volume ratio of (4.5~5.5):(4.5~5.5):1; the concentration of nitric acid is 65~68wt%, the concentration of hydrofluoric acid is 40~45wt%, and the concentration of sulfuric acid is 95~98wt%. The etching process is performed at a temperature of 24-28°C for 35-45 seconds. (3) The metallographic structure of the test sample was observed using a portable microscope.

Images