Sample preparation method of molybdenum target material for EBSD detection

Abstract

The invention relates to a sample preparation method of a molybdenum target material for EBSD detection, and the sample preparation method comprises the following steps: (1) grinding a molybdenum target material sample, the grinding treatment comprises first grinding, second grinding and third grinding which are carried out in sequence, and a first molybdenum target material sample is obtained; (2) the first molybdenum target material sample obtained in the step (1) is subjected to electrolytic polishing treatment, a second molybdenum target material sample is obtained, and an electrolyte adopted in the electrolytic polishing treatment comprises a mixed solution of methyl alcohol, ethylene glycol monobutyl ether and perchloric acid; and (3) the second molybdenum target sample obtained in the step (2) is subjected to corrosion treatment, and the EBSD detection sample is obtained. The sample prepared by the sample preparation method provided by the invention has the advantages of smooth and flat surface, no scratch, clear sample diffraction Kikuchi zone and high calibration rate, and meets the requirements of molybdenum target EBSD detection.

Description

Technical Field

[0001] The present invention relates to the technical field of target materials, and particularly to a method for preparing a molybdenum target for EBSD detection. Background Art

[0002] Sputtering targets are widely used in industries such as electronics and information, glass coating, and wear-resistant materials. Mainly through the magnetron sputtering process, under the action of an electric field, Ar ions accelerate to bombard the target surface, so that target atoms break away and deposit on the substrate to form a thin film.

[0003] Among them, the semiconductor industry has high requirements for the purity and performance of sputtering targets, and the internal microstructure of the target will seriously affect the performance of the thin film. In order to detect the internal microstructure and tissue uniformity of the target, the existing process usually uses electron backscatter diffraction (EBSD) technology to detect the target. The EBSD technology combines the high-resolution imaging ability of a scanning electron microscope (SEM) and the crystallographic analysis ability of X-ray diffraction (XRD). It can achieve diffraction analysis with a spatial resolution of sub-micron level while retaining the conventional characteristics of SEM, and is applicable to a variety of polycrystalline materials, including ceramics, semiconductors, superconductors, and ores. The EBSD technology can provide rich crystallographic information, such as orientation difference, orientation relationship, orientation distribution function (ODF), and interface crystal plane index, etc., providing strong support for in-depth research on the performance of materials.

[0004] Molybdenum target is a metal material mainly composed of molybdenum, with a high melting point, good electrical and thermal conductivity, and excellent mechanical properties. In EBSD detection, the surface quality of the molybdenum target has a crucial impact on the accuracy and reliability of the detection results. The detection surface of the molybdenum target needs to meet the following requirements: (1) The surface is smooth and flat, with high flatness; (2) There are no obvious scratches, as scratches will interfere with the diffraction signal of backscattered electrons; (3) There is no dirt; (4) There is no surface stress. However, the existing methods for preparing molybdenum targets cannot achieve an ideal detection state, and the EBSD calibration rate is not high.

[0005] Therefore, providing a method for preparing a molybdenum target for EBSD detection is a technical problem that needs to be solved in the current field. Summary of the Invention

[0006] Aiming at the above problems, the purpose of the present invention is to provide a method for preparing a molybdenum target for EBSD detection. Compared with the existing technology, the sample obtained by the preparation method provided by the present invention has a smooth and flat surface, no scratches, clear diffraction Kikuchi bands of the sample, and a high calibration rate, meeting the requirements of EBSD detection of molybdenum targets.

[0007] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a sample preparation method for a molybdenum target for EBSD detection, and the sample preparation method includes the following steps:

[0009] (1) Grind the molybdenum target sample, and the grinding process includes first grinding, second grinding, and third grinding carried out in sequence to obtain a first molybdenum target sample;

[0010] (2) Electrolytically polish the first molybdenum target sample obtained in step (1) to obtain a second molybdenum target sample, and the electrolyte used in the electrolytic polishing process includes a mixed solution of methanol, ethylene glycol monobutyl ether, and perchloric acid;

[0011] (3) Corrode the second molybdenum target sample obtained in step (2) to obtain an EBSD detection sample.

[0012] In the sample preparation method provided by the present invention, first, larger defects and scratches on the sample surface are removed through grinding. Among them, the first grinding, second grinding, and third grinding are controlled to be carried out in sequence, so as to control the processing accuracy from rough to fine, and a relatively smooth surface can be initially obtained, providing a good foundation for subsequent electrolytic polishing and corrosion treatments. It is worth noting that in the electrolytic polishing treatment adopted by the present invention, a mixed solution of methanol, ethylene glycol monobutyl ether, and perchloric acid is specifically used as the electrolyte, which can significantly improve the microscopic unevenness on the surface of the molybdenum target sample, making the surface smoother and more uniform. Then, through the corrosion treatment, the microscopic morphology on the surface of the target is further made clearer, facilitating the EBSD system to accurately collect and analyze the backscattered electron diffraction signal.

[0013] Preferably, the molybdenum target sample is cut before the grinding process in step (1).

[0014] Preferably, the size of the molybdenum target sample after the cutting process is (10 - 20) cm × (10 - 20) cm × (5 - 15) cm. For example, it can be 10 cm × 10 cm × 5 cm, 15 cm × 15 cm × 10 cm, or 20 cm × 20 cm × 15 cm, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0015] Preferably, the grinding medium used in the grinding process in step (1) includes silica sandpaper.

[0016] Preferably, the grit size of the sandpaper used in the first grinding is 240#.

[0017] Preferably, the grit size of the sandpaper used in the second grinding is 600#.

[0018] Preferably, the grit size of the sandpaper used in the third grinding is 1000#.

[0019] Preferably, the time for the first grinding in step (1) is 5 - 10 min. For example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0020] Preferably, the time for the second grinding in step (1) is 5 - 10 min. For example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0021] Preferably, the time for the third grinding in step (1) is 5 - 10 min. For example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0022] In the present invention, by preferably controlling the mesh number and time of the sandpaper used for the first grinding, the second grinding, and the third grinding, the scratches on the surface of the sample can be gradually reduced and minimized, reducing the time for subsequent electrolytic polishing treatment and corrosion treatment.

[0023] Preferably, in the electrolyte used for the electrolytic polishing treatment in step (2), the volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid is (70 - 80):(15 - 25):(5 - 7). For example, it can be 70:15:5, 70:20:5, 75:20:5, 75:20:6, 80:25:5, or 80:25:7, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] Preferably, the mass concentration of perchloric acid is 70 - 72%. For example, it can be 70%, 70.5%, 71%, 71.5%, or 72%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0025] Preferably, the voltage for the electrolytic polishing treatment in step (2) is 22 - 28 V. For example, it can be 22 V, 23 V, 24 V, 25 V, 26 V, 27 V, or 28 V, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0026] Preferably, the time for the electrolytic polishing treatment is 5 - 15 s. For example, it can be 5 s, 6 s, 7 s, 8 s, 9 s, 10 s, 11 s, 12 s, 13 s, 14 s, or 15 s, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0027] In the present invention, by preferably controlling the volume ratio of methanol, ethylene glycol monobutyl ether and perchloric acid, voltage and time in the electrolyte used for electrolytic polishing treatment, the smoothness of the sample surface can be further improved, impurities, oxides and residual micro-scratches can be removed, and the surface quality and purity can be enhanced.

[0028] Preferably, the etching solution used in the etching treatment in step (2) includes nitric acid.

[0029] Preferably, the concentration of the nitric acid is 65 - 68%, for example, it can be 65%, 65.5%, 66%, 66.5%, 67%, 67.5% or 68%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0030] Preferably, the time of the etching treatment is 2 - 5 s, for example, it can be 2 s, 3 s, 4 s or 5 s, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] In the present invention, by preferably controlling the acid concentration and time of the etching treatment, the microstructure on the surface of the target can be further shown more clearly, and at the same time, damage to the sample surface caused by etching can be avoided.

[0032] Preferably, after the etching treatment, the sample is successively cleaned and dried.

[0033] As a preferred technical solution of the present invention, the sample preparation method includes the following steps:

[0034] (1) Grind the molybdenum target sample, that is, first perform the first grinding with 240# silicon dioxide sandpaper, then perform the second grinding with 600# silicon dioxide sandpaper, and then perform the third grinding with 1000# silicon dioxide sandpaper to obtain the first molybdenum target sample;

[0035] (2) Electrolytically polish the first molybdenum target sample obtained in step (1) for 5 - 15 s under the condition of a voltage of 22 - 28 V. The volume ratio of methanol, ethylene glycol monobutyl ether and perchloric acid in the electrolyte used for the electrolytic polishing treatment is (70 - 80):(15 - 25):(5 - 7), and the mass concentration of the perchloric acid is 70 - 72% to obtain the second molybdenum target sample;

[0036] (3) Etch the second molybdenum target sample obtained in step (2) with nitric acid having a mass concentration of 65 - 68% for 2 - 5 s, and then successively clean and dry it to obtain an EBSD detection sample.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The sample obtained by the sample preparation method provided by the present invention has a smooth and flat surface without scratches, and the diffraction Kikuchi bands of the sample are clear, with a high calibration rate. Under better conditions, the calibration rate reaches more than 98%, meeting the requirements for EBSD detection of molybdenum target materials. Specific Embodiments

[0039] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0040] Example 1

[0041] This example provides a sample preparation method for tantalum target materials for EBSD detection. The sample preparation method includes the following steps:

[0042] (1) Cut the molybdenum target material sample to a size of 15 cm × 15 cm × 10 cm, and then perform grinding treatment. First, perform the first grinding with 240# silica sandpaper for 5 minutes, then perform the second grinding with 600# silica sandpaper for 5 minutes, and then perform the third grinding with 1000# silica sandpaper for 5 minutes to obtain the first molybdenum target material sample;

[0043] (2) Electrolytically polish the first molybdenum target material sample obtained in step (1) for 10 s under the condition of a voltage of 25 V. The volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid in the electrolyte used for the electrolytic polishing treatment is 75:20:6, that is, 750 mL, 200 mL, and 60 mL in sequence, and the mass concentration of perchloric acid is 72% to obtain the second molybdenum target material sample;

[0044] (3) Corrode the second molybdenum target material sample obtained in step (2) with 68% nitric acid by mass for 2 s, and then perform cleaning and drying in sequence to obtain an EBSD detection sample.

[0045] Example 2

[0046] This example provides a sample preparation method for tantalum target materials for EBSD detection. The sample preparation method includes the following steps:

[0047] (1) Cut the molybdenum target material sample to a size of 15 cm × 15 cm × 10 cm, and then perform grinding treatment. First, perform the first grinding with 240# silica sandpaper for 5 minutes, then perform the second grinding with 600# silica sandpaper for 5 minutes, and then perform the third grinding with 1000# silica sandpaper for 5 minutes to obtain the first molybdenum target material sample;

[0048] (2) Electropolish the first molybdenum target sample obtained in step (1) for 15 s under the condition of a voltage of 22 V. The volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid in the electrolyte used for the electropolishing treatment is 70:15:7, namely 700 mL, 150 mL, and 70 mL in sequence, and the mass concentration of perchloric acid is 72%, to obtain a second molybdenum target sample;

[0049] (3) Corrode the second molybdenum target sample obtained in step (2) with nitric acid with a mass concentration of 68% for 3 s, and then perform cleaning and drying in sequence to obtain an EBSD detection sample.

[0050] Example 3

[0051] This example provides a method for preparing a tantalum target for EBSD detection. The method for preparing the sample includes the following steps:

[0052] (1) Cut the molybdenum target sample to a size of 15 cm × 15 cm × 10 cm, and then perform grinding treatment, that is, first perform the first grinding with 240# silicon carbide sandpaper for 5 min, then perform the second grinding with 600# silicon carbide sandpaper for 5 min, and then perform the third grinding with 1000# silicon carbide sandpaper for 5 min to obtain a first molybdenum target sample;

[0053] (2) Electropolish the first molybdenum target sample obtained in step (1) for 5 s under the condition of a voltage of 28 V. The volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid in the electrolyte used for the electropolishing treatment is 80:25:5, namely 800 mL, 250 mL, and 50 mL in sequence, and the mass concentration of perchloric acid is 72%, to obtain a second molybdenum target sample;

[0054] (3) Corrode the second molybdenum target sample obtained in step (2) with nitric acid with a mass concentration of 68% for 5 s, and then perform cleaning and drying in sequence to obtain an EBSD detection sample.

[0055] Example 4

[0056] This example provides a method for preparing a tantalum target for EBSD detection. The difference compared with Example 1 is only that the total volume of the electrolyte is kept unchanged, and the volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid is adjusted to 60:20:6.

[0057] Example 5

[0058] This example provides a method for preparing a tantalum target for EBSD detection. The difference compared with Example 1 is only that the total volume of the electrolyte is kept unchanged, and the volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid is adjusted to 90:20:6.

[0059] Example 6

[0060] This example provides a method for preparing a tantalum target for EBSD detection. The only difference compared with Example 1 is that the voltage for electrolytic polishing treatment is 20V.

[0061] Example 7

[0062] This example provides a method for preparing a tantalum target for EBSD detection. The only difference compared with Example 1 is that the voltage for electrolytic polishing treatment is 30V.

[0063] Example 8

[0064] This example provides a method for preparing a tantalum target for EBSD detection. The only difference compared with Example 1 is that the time for electrolytic polishing treatment is 2s.

[0065] Example 9

[0066] This example provides a method for preparing a tantalum target for EBSD detection. The only difference compared with Example 1 is that the time for electrolytic polishing treatment is 25s.

[0067] Comparative Example 1

[0068] This comparative example provides a method for preparing a molybdenum target for EBSD detection. The only difference compared with Example 1 is that no grinding treatment is performed, and the molybdenum target sample is directly subjected to electrolytic polishing treatment.

[0069] Comparative Example 2

[0070] This comparative example provides a method for preparing a molybdenum target for EBSD detection. The only difference compared with Example 1 is that no electrolytic polishing treatment is performed, and the first molybdenum target sample is directly subjected to corrosion treatment.

[0071] Comparative Example 3

[0072] This comparative example provides a method for preparing a molybdenum target for EBSD detection. The only difference compared with Example 1 is that no corrosion treatment is performed, and the second molybdenum target sample is the EBSD detection sample.

[0073] The EBSD detection samples obtained from the above examples and comparative examples were subjected to EBSD detection, and the calibration rates obtained are shown in Table 1.

[0074] Table 1

[0075]

[0076]

[0077] The following points can be seen from the data in Table 1:

[0078] (1) From the data of Examples 1-3, it can be seen that by using the sample preparation method provided by the present invention, under relatively optimal conditions, the calibration rate of the EBSD detection sample can reach more than 98%.

[0079] (2) By comprehensively comparing the data of Example 1 and Examples 4-9, it can be seen that the present invention can further improve the EBSD calibration rate of the sample by preferably controlling the electrolyte composition, voltage and time of the electrolytic polishing treatment.

[0080] (3) By comprehensively comparing the data of Example 1 and Comparative Examples 1-3, it can be seen that by adopting the combined operations of grinding treatment, electrolytic polishing treatment and corrosion treatment, the present invention can make the sample surface smooth and free of scratches, so that the EBSD detection sample has a high calibration rate.

[0081] In summary, the sample obtained by the sample preparation method provided by the present invention has a smooth and flat surface, no scratches, clear diffraction Kikuchi bands of the sample, a high calibration rate, and meets the requirements of EBSD detection of molybdenum target materials.

[0082] The applicant declares that the above description is only the specific implementation manner 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 thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A method for preparing a molybdenum target material for EBSD detection, characterized in that, The sample preparation method includes the following steps: (1) Grind the molybdenum target material sample. The grinding process includes first grinding, second grinding, and third grinding performed in sequence to obtain a first molybdenum target material sample; (2) Perform electrolytic polishing on the first molybdenum target material sample obtained in step (1) to obtain a second molybdenum target material sample. The electrolyte used for the electrolytic polishing process includes a mixed solution of methanol, ethylene glycol monobutyl ether, and perchloric acid; (3) Corrode the second molybdenum target material sample obtained in step (2) to obtain an EBSD detection sample.

2. The sample preparation method according to claim 1, characterized in that The grinding medium used in the grinding process of step (1) includes silica sandpaper.

3. The sample preparation method according to claim 2, wherein The sandpaper mesh number used for the first grinding in step (1) is 240#; Preferably, the sandpaper mesh number used for the second grinding is 600#; Preferably, the sandpaper mesh number used for the third grinding is 1000#.

4. The sample preparation method according to any one of claims 1-3, characterized in that In the electrolyte used for the electrolytic polishing process of step (2), the volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid is (70 - 80):(15 - 25):(5 - 7).

5. The sample preparation method according to claim 4, wherein The mass concentration of perchloric acid in step (2) is 70 - 72%; 6. The sample preparation method according to any one of claims 1-5, characterized in that, The voltage for the electrolytic polishing process in step (2) is 22 - 28V.

7. The sample preparation method according to any one of claims 1-6, characterized in that The time for the electrolytic polishing process in step (2) is 5 - 15s.

8. The sample preparation method according to any one of claims 1-7, characterized in that, The etching solution used for the etching process in step (3) includes nitric acid; Preferably, the concentration of nitric acid is 65 - 68%.

9. The sample preparation method according to any one of claims 1-8, characterized in that, The time for the etching process in step (3) is 2 - 5s; Preferably, after the etching process, the sample is washed and dried in sequence.

10. The sample preparation method according to any one of claims 1-9, characterized in that, The sample preparation method includes the following steps: (1) Grind the molybdenum target material sample, that is, first perform the first grinding with 240# silica sandpaper, then perform the second grinding with 600# silica sandpaper, and then perform the third grinding with 1000# silica sandpaper to obtain a first molybdenum target material sample; (2) Perform electrolytic polishing on the first molybdenum target material sample obtained in step (1) for 5 - 15s under the condition of a voltage of 22 - 28V. The volume ratio of methanol, ethylene glycol monobutyl ether, and perchloric acid in the electrolyte used for the electrolytic polishing process is (70 - 80):(15 - 25):(5 - 7), and the mass concentration of perchloric acid is 70 - 72% to obtain a second molybdenum target material sample; (3) Corrode the second molybdenum target material sample obtained in step (2) with nitric acid having a mass concentration of 65 - 68% for 2 - 5s, and then wash and dry in sequence to obtain an EBSD detection sample.

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