A molybdenum-silicon alloy tube target and its preparation method

Abstract

This invention provides a molybdenum-silicon alloy target and its preparation method. The preparation method includes: mixing molybdenum powder and silicon powder to form a mixed powder; the average particle size of the molybdenum powder is larger than the average particle size of the silicon powder; placing the mixed powder in a bidirectional pressure mold and performing vacuum hot pressing sintering to obtain the molybdenum-silicon alloy target. By controlling the particle size range of the molybdenum and silicon raw materials, the powder tap density is increased by filling the gaps between large particles with small particles. Then, a bidirectional pressure mold design is adopted to solve the problem of insufficient density at the bottom of the target. Finally, vacuum hot pressing sintering is performed to obtain a high-density molybdenum-silicon alloy target. The preparation method has fewer steps, faster production speed, and the obtained molybdenum-silicon alloy target has excellent sputtering performance.

Description

Technical Field

[0001] This invention belongs to the field of target preparation technology, and relates to a molybdenum-silicon alloy tube target and its preparation method. Background Technology

[0002] Thin films formed by sputtering molybdenum-silicon targets exhibit low resistivity and good adhesion, making them suitable for conductive paths or electrode materials in high-frequency, high-power semiconductor devices. Furthermore, molybdenum-silicon alloy targets, due to their high melting point, excellent high-temperature stability, and oxidation resistance, can be used to prepare electronic gate materials or contact layer films. Targets are mainly divided into planar targets and tubular targets. Compared to planar targets, tubular targets offer higher utilization rates and more uniform coating composition, making them the standard choice for magnetron sputtering coating technology.

[0003] Currently, the main methods for producing target tubes include thermal spraying, casting, and powder metallurgy. Thermal spraying involves applying metal powder to the workpiece using plasma thermal spraying. Target tubes produced using this method have low density, uneven structure, numerous pores, and high oxygen content, limiting their application to less demanding coating industries such as glass. Casting involves directly casting the target material onto a liner tube, but it is only suitable for target materials with low melting points, such as Sn and Zn. Powder metallurgy, on the other hand, produces target tubes with uniform composition, fine grains, and high purity, meeting the requirements of the LCD and touchscreen industries.

[0004] CN101259584A discloses a method for preparing high-density molybdenum tubes. The method involves isostatically pressing molybdenum powder, sintering it under hydrogen protection to form a ring-shaped molybdenum tube blank, and then forging, extruding, annealing, followed by machining, cleaning, and drying to obtain the high-density molybdenum tube. Although the molybdenum tubes produced by this method have high density, they are prone to cracking during forging and have low material utilization.

[0005] In summary, providing a molybdenum-silicon alloy tube target with high density and high material utilization, and its preparation method, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a molybdenum-silicon alloy tube target and its preparation method. By optimizing the preparation process and combining it with a bidirectional pressure mold design, a high-density molybdenum-silicon alloy tube target can be obtained, giving it excellent sputtering performance.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing a molybdenum-silicon alloy tube target, the method comprising:

[0009] Molybdenum powder and silicon powder are mixed to form a mixed powder;

[0010] The average particle size of the molybdenum powder is greater than that of the silicon powder;

[0011] The mixed powder is placed in a bidirectional pressure mold and subjected to vacuum hot pressing sintering to obtain the molybdenum-silicon alloy tube target.

[0012] The preparation method provided by this invention controls the particle size range of molybdenum and silicon raw materials, using small particles to fill the gaps between large particles to increase the powder tap density. Then, a bidirectional pressure mold design is employed to address the problem of insufficient density at the bottom of the target tube. Finally, vacuum hot pressing sintering is performed to obtain a high-density molybdenum-silicon alloy target tube. This preparation method has fewer steps, faster production speed, and the obtained molybdenum-silicon alloy target tube exhibits excellent sputtering performance.

[0013] It should be noted that the preparation method described in this invention, by using a specific mold, can sinter molybdenum-silicon mixed powder into a molybdenum-silicon alloy tube target using a vacuum hot pressing sintering process, thereby avoiding the use of cold isostatic pressing and hot isostatic pressing processes, saving production time, energy and cost.

[0014] Preferably, the atomic ratio of the molybdenum powder to the silicon powder is 1:(3~5), for example, it can be 1:3.2, 1:3.5, 1:3.6, 1:3.8, 1:4, 1:4.2, 1:4.5, 1:4.6 or 1:4.8, etc.

[0015] In this invention, high-purity molybdenum powder and high-purity silicon powder are selected as raw materials, wherein the purity of both molybdenum powder and silicon powder is ≥4N.

[0016] Preferably, the average particle size of the molybdenum powder is 6μm to 7μm, for example, it can be 6.1μm, 6.2μm, 6.3μm, 6.4μm, 6.5μm, 6.6μm, 6.7μm, 6.8μm or 6.9μm.

[0017] Preferably, the average particle size of the silicon powder is 1μm to 3μm, for example, it can be 1.2μm, 1.4μm, 1.5μm, 1.6μm, 1.8μm, 2μm, 2.2μm, 2.4μm, 2.5μm, 2.6μm or 2.8μm, etc.

[0018] It should be noted that by controlling the average particle size range of molybdenum powder and silicon powder, firstly, small particles can be used to fill the gaps between large particles to increase the powder tap density, and secondly, it facilitates the subsequent processing to quickly form a mixed powder of the required particle size, so as to ensure that the resulting target has fine grains.

[0019] Preferably, the ball-to-particle ratio is (0.5~1.5):1, for example, it can be 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1 or 1.4:1, etc.

[0020] In this invention, the mixed grinding media includes zirconium balls and / or titanium balls.

[0021] Preferably, the mixing time is ≥24h, such as 25h, 26h, 28h, 30h, 32h, 34h, 35h or 36h.

[0022] In this invention, the mixing time is ≥24h to ensure that the molybdenum powder and silicon powder are mixed evenly. If the mixing time is too long, it will increase the risk of introducing impurities and increase the cost. If the mixing time is too short, the molybdenum powder and silicon powder cannot form a uniform mixture, which will affect the performance of the molybdenum-silicon alloy target.

[0023] Preferably, the bidirectional pressure mold includes an annular mold body, an upper pressure head, and a lower pressure head.

[0024] In this invention, the order of loading powder includes: first loading the lower pressure head into the bidirectional pressure mold, and then loading the mixed powder and the upper pressure head into the bidirectional pressure mold in sequence.

[0025] Preferably, the annular mold body is provided with annular channels for accommodating the mixed powder.

[0026] Preferably, graphite paper is provided inside the sidewall of the annular channel.

[0027] In this invention, the annular mold body is formed by splicing graphite inside and out. To prevent the mold from sticking together, graphite paper is placed inside the side wall of the annular channel.

[0028] Preferably, the upper pressure head and the lower pressure head are placed independently above and below the annular channel, respectively.

[0029] Preferably, both the upper and lower pressure heads are higher than the end face of the annular mold body, and the height difference is >20cm, such as 21cm, 22cm, 23cm, 24cm, 25cm, 26cm, 28cm or 30cm.

[0030] Preferably, the widths of the upper and lower pressure heads are the same as the width of the annular channel.

[0031] It should be noted that both the upper and lower pressure heads are annular pressure heads. By controlling the height and width range of the upper and lower pressure heads, the mixed powder can be subjected to bidirectional pressure during the vacuum hot pressing sintering process. This ensures that the mixed powder in the mold is subjected to uniform force throughout the process, resulting in uniform compaction and a molybdenum-silicon alloy tube target with high density.

[0032] Preferably, the annular mold body, the upper pressure head, and the lower pressure head are all made of graphite.

[0033] Preferably, the vacuum hot pressing sintering includes sequentially performing a first heating, a second heating, a third holding, a fourth heating, a fifth holding, a sixth heating, a seventh holding, an eighth heating, and a ninth holding.

[0034] Preferably, the vacuum degree of the vacuum hot pressing sintering is <10Pa, for example, it can be 9Pa, 8Pa, 7Pa, 6Pa, 5Pa, 4Pa or 2Pa, etc.

[0035] Preferably, after the first heating and before the second heating, a continuous pressurization process is performed. The pressure endpoint of the continuous pressurization process at the end of the ninth heat preservation is 38MPa~42MPa, for example, it can be 38.5MPa, 39MPa, 39.5MPa, 40MPa, 40.5MPa, 41MPa or 41.5MPa, etc.

[0036] In this invention, the starting pressure of the continuous pressurization process is atmospheric pressure, and the continuous pressurization process adopts a uniform rate of pressure increase to the pressure endpoint.

[0037] Preferably, the ninth insulation step is followed by insulation and pressure maintenance.

[0038] In this invention, after heat preservation and pressure holding, the furnace was cooled to room temperature.

[0039] It should be noted that by adopting a staged heating and holding process, combined with a vacuum hot pressing sintering process with continuous pressure treatment to sinter the mixed powder, it is not only conducive to the diffusion of molybdenum and silicon atoms, but also to making the internal structure more compact. This ensures that the porosity inside the molybdenum-silicon alloy tube target formed later is reduced and the density is greatly improved.

[0040] Preferably, the heat preservation and pressure holding time is 160min~200min, for example, it can be 165min, 170min, 175min, 180min, 185min, 190min or 195min, etc.

[0041] Preferably, the heating rate of the first heating is 4℃ / min to 6℃ / min, for example, 4.2℃ / min, 4.5℃ / min, 4.8℃ / min, 5℃ / min, 5.2℃ / min, 5.5℃ / min or 5.8℃ / min, etc.

[0042] In this invention, the starting temperature for the first heating is room temperature.

[0043] Preferably, the endpoint temperature of the first heating is 750℃~850℃, such as 760℃, 770℃, 780℃, 790℃, 800℃, 810℃, 820℃, 830℃ or 840℃.

[0044] Preferably, the heating rate of the second heating is 1.5℃ / min to 2.5℃ / min, such as 1.6℃ / min, 1.8℃ / min, 2℃ / min, 2.2℃ / min or 2.4℃ / min.

[0045] Preferably, the endpoint temperature of the second heating is 1080℃~1120℃, such as 1085℃, 1090℃, 1095℃, 1100℃, 1105℃, 1110℃ or 1115℃.

[0046] Preferably, the third heat preservation time is 50 min to 70 min, for example, it can be 52 min, 55 min, 56 min, 58 min, 60 min, 62 min, 65 min, 66 min or 68 min, etc.

[0047] Preferably, the heating rate of the fourth heating is 0.5℃ / min to 1.5℃ / min, for example, 0.6℃ / min, 0.8℃ / min, 1℃ / min, 1.2℃ / min or 1.4℃ / min.

[0048] Preferably, the final temperature of the fourth heating is 1180℃~1220℃, such as 1185℃, 1190℃, 1195℃, 1200℃, 1205℃, 1210℃ or 1215℃.

[0049] Preferably, the fifth heat preservation time is 110 min to 130 min, for example, it can be 112 min, 115 min, 116 min, 118 min, 120 min, 122 min, 125 min, 126 min or 128 min, etc.

[0050] Preferably, the heating rate of the sixth heating step is 0.5℃ / min to 1.5℃ / min, for example, 0.6℃ / min, 0.8℃ / min, 1℃ / min, 1.2℃ / min or 1.4℃ / min.

[0051] Preferably, the final temperature of the sixth heating step is 1260℃~1280℃, such as 1262℃, 1265℃, 1268℃, 1270℃, 1272℃, 1275℃ or 1278℃.

[0052] Preferably, the seventh heat preservation time is 110 min to 130 min, for example, it can be 112 min, 115 min, 116 min, 118 min, 120 min, 122 min, 125 min, 126 min or 128 min, etc.

[0053] Preferably, the heating rate of the eighth heating step is 0.5℃ / min to 1.5℃ / min, for example, 0.6℃ / min, 0.8℃ / min, 1℃ / min, 1.2℃ / min or 1.4℃ / min.

[0054] Preferably, the endpoint temperature of the eighth heating is 1320℃~1340℃, such as 1322℃, 1325℃, 1328℃, 1330℃, 1332℃, 1335℃ or 1338℃.

[0055] Preferably, the ninth heat preservation time is 50 min to 70 min, for example, it can be 52 min, 55 min, 56 min, 58 min, 60 min, 62 min, 65 min, 66 min or 68 min, etc.

[0056] It should be noted that by optimizing the range of parameters such as temperature and holding time in vacuum hot pressing sintering, the densification degree of the molybdenum-silicon alloy tube target can be further improved, ensuring the excellent performance of the obtained molybdenum-silicon alloy tube target.

[0057] In a second aspect, the present invention provides a molybdenum-silicon alloy tube target, which is prepared by the preparation method described in the first aspect.

[0058] Preferably, the density of the molybdenum-silicon alloy target is ≥99%.

[0059] Preferably, the wall thickness of the molybdenum-silicon alloy tube target is ≤7mm, for example, it can be 6.8mm, 6.5mm, 6.2mm, 6mm, 5.8mm, 5.5mm, 5.2mm, 5mm or 4.5mm, etc.; the length is ≥100mm, for example, it can be 110mm, 120mm, 130mm, 140mm, 150mm, 160mm or 170mm, etc.

[0060] In this invention, the outer diameter of the molybdenum-silicon alloy tube target is ≥130mm.

[0061] The molybdenum-silicon alloy target prepared by this invention has high density even with a small wall thickness and long length, which makes the film prepared by it in subsequent sputtering molding have excellent quality.

[0062] 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.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] (1) The preparation method provided by the present invention controls the particle size range of molybdenum and silicon raw materials, uses small particles to fill the gaps between large particles to increase the powder tap density, and then adopts a bidirectional pressure mold design to solve the problem of insufficient density at the bottom of the target tube. Finally, vacuum hot pressing sintering is performed to obtain a high-density molybdenum-silicon alloy target tube. The preparation method has few steps and fast production speed, and the obtained molybdenum-silicon alloy target tube has excellent sputtering performance.

[0065] (2) The molybdenum-silicon alloy tube target prepared by the present invention still has high density even when the wall thickness of the tube target is small and the length is long; wherein, the density is ≥99%. Attached Figure Description

[0066] Figure 1 This is a cross-sectional view of the bidirectional pressure mold provided in Example 1;

[0067] Among them, 1-ring mold body, 2-upper pressure head, 3-lower pressure head, 4-ring channel filled with mixed powder, 5-graphite paper. Detailed Implementation

[0068] 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.

[0069] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0070] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0071] Example 1

[0072] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target, the method comprising the following steps:

[0073] (1) Provide molybdenum powder with an average particle size of 6.5 μm and a purity of 4N5 and silicon powder with an average particle size of 2 μm and a purity of 4N8, and then mix the molybdenum powder and silicon powder in a full-motion powder mixer at an atomic ratio of 1:4 for 24 hours. The grinding media used for mixing is zirconium balls, and the ball-to-material ratio is 1:1 to form mixed powder.

[0074] (2) The mixed powder described in step (1) is placed in a bidirectional pressure mold and vacuum hot pressing is performed to obtain a molybdenum-silicon alloy tube target with a wall thickness of 5.5 mm and a length of 145 mm.

[0075] The bidirectional pressure mold (such as) Figure 1 The device (shown) includes an annular mold body 1, an upper pressure head 2, and a lower pressure head 3. The annular mold body 1 is provided with an annular channel 4 for accommodating mixed powder. Graphite paper 5 is arranged inside the side wall of the annular channel 4. The upper pressure head 2 and the lower pressure head 3 are independently placed above and below the annular channel 4, respectively. Both the upper pressure head 2 and the lower pressure head 3 are higher than the end face of the annular mold body 1, and the height difference is 25 cm. The width of both the upper pressure head 2 and the lower pressure head 3 is the same as the width of the annular channel 4. The material of the annular mold body 1, the upper pressure head 2, and the lower pressure head 3 is graphite.

[0076] The vacuum hot pressing sintering includes sequentially performing the following steps: first heating, second heating, third holding, fourth heating, fifth holding, sixth heating, seventh holding, eighth heating, ninth holding, and holding and pressing for 180 minutes, and then cooling to room temperature with the furnace.

[0077] The vacuum degree of the vacuum hot pressing sintering is 5 Pa;

[0078] After the first heating and before the second heating, a continuous pressurization process was performed. The starting pressure of the continuous pressurization process was 0.1 MPa, and the ending pressure of the continuous pressurization process at the end of the ninth heat preservation was 40 MPa.

[0079] The first heating starts at room temperature, with a heating rate of 5℃ / min and an ending temperature of 800℃; the second heating has a heating rate of 2℃ / min and an ending temperature of 1100℃; the third holding time is 60 min; the fourth heating has a heating rate of 1℃ / min and an ending temperature of 1200℃; the fifth holding time is 120 min; the sixth heating has a heating rate of 1℃ / min and an ending temperature of 1270℃; the seventh holding time is 120 min; the eighth heating has a heating rate of 1℃ / min and an ending temperature of 1330℃; and the ninth holding time is 60 min.

[0080] Example 2

[0081] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target, the method comprising the following steps:

[0082] (1) Provide molybdenum powder with an average particle size of 6μm and a purity of 4N6 and silicon powder with an average particle size of 1μm and a purity of 4N5, and then mix the molybdenum powder and silicon powder in a full-motion powder mixer at an atomic ratio of 1:4 for 26 hours. The grinding media used for mixing is zirconium balls, and the ball-to-material ratio is 1.2:1 to form mixed powder.

[0083] (2) The mixed powder described in step (1) is placed in a bidirectional pressure mold and vacuum hot pressing is performed to obtain a molybdenum-silicon alloy tube target with a wall thickness of 5.5 mm and a length of 145 mm.

[0084] The bidirectional pressure mold is the one provided in Example 1;

[0085] The vacuum hot pressing sintering includes sequentially performing the following steps: first heating, second heating, third holding, fourth heating, fifth holding, sixth heating, seventh holding, eighth heating, ninth holding, and holding and pressing for 160 minutes, and then cooling to room temperature with the furnace.

[0086] The vacuum degree of the vacuum hot pressing sintering is 5 Pa;

[0087] After the first heating and before the second heating, a continuous pressurization process was performed. The starting pressure of the continuous pressurization process was 0.1 MPa, and the ending pressure of the continuous pressurization process at the end of the ninth heat preservation was 38 MPa.

[0088] The first heating has a starting temperature of room temperature, a heating rate of 6℃ / min, and an ending temperature of 850℃; the second heating has a heating rate of 1.5℃ / min and an ending temperature of 1120℃; the third holding time is 70min; the fourth heating has a heating rate of 1.5℃ / min and an ending temperature of 1220℃; the fifth holding time is 130min; the sixth heating has a heating rate of 1.5℃ / min and an ending temperature of 1280℃; the seventh holding time is 110min; the eighth heating has a heating rate of 1.5℃ / min and an ending temperature of 1340℃; and the ninth holding time is 70min.

[0089] Example 3

[0090] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target, the method comprising the following steps:

[0091] (1) Provide molybdenum powder with an average particle size of 7μm and a purity of 4N2 and silicon powder with an average particle size of 3μm and a purity of 4N6, and then mix the molybdenum powder and silicon powder in a full-motion powder mixer at an atomic ratio of 1:4 for 24 hours. The grinding media used for mixing is zirconium balls, and the ball-to-material ratio is 0.8:1 to form mixed powder.

[0092] (2) The mixed powder described in step (1) is placed in a bidirectional pressure mold and vacuum hot pressing is performed to obtain a molybdenum-silicon alloy tube target with a wall thickness of 5.5 mm and a length of 145 mm.

[0093] The bidirectional pressure mold is the one provided in Example 1;

[0094] The vacuum hot pressing sintering includes sequential heating, heating, holding, heating, holding, holding pressure for 200 minutes, and then cooling to room temperature in the furnace.

[0095] The vacuum degree of the vacuum hot pressing sintering is 5 Pa;

[0096] After the first heating and before the second heating, a continuous pressurization process was performed. The starting pressure of the continuous pressurization process was 0.1 MPa, and the ending pressure of the continuous pressurization process at the end of the ninth heat preservation was 42 MPa.

[0097] The first heating starts at room temperature, with a heating rate of 4℃ / min and an ending temperature of 750℃; the second heating has a heating rate of 2.5℃ / min and an ending temperature of 1080℃; the third holding time is 50 min; the fourth heating has a heating rate of 0.8℃ / min and an ending temperature of 1180℃; the fifth holding time is 110 min; the sixth heating has a heating rate of 0.8℃ / min and an ending temperature of 1260℃; the seventh holding time is 130 min; the eighth heating has a heating rate of 0.8℃ / min and an ending temperature of 1320℃; and the ninth holding time is 50 min.

[0098] Example 4

[0099] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the average particle size of the molybdenum powder in step (1) being 15 μm, all other conditions are the same as in Example 1.

[0100] Example 5

[0101] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the average particle size of the molybdenum powder in step (1) being 5 μm, all other conditions are the same as in Example 1.

[0102] Example 6

[0103] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the height difference of the upper and lower pressure heads with the end face of the annular mold body in step (2) being 10cm, all other conditions are the same as in embodiment 1.

[0104] Example 7

[0105] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the continuous pressurization process performed simultaneously during the first heating in step (2), all other conditions are the same as in Example 1.

[0106] Example 8

[0107] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the pressure endpoint of the continuous pressurization treatment in step (2) being 30 MPa, all other conditions are the same as in Example 1.

[0108] Example 9

[0109] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the pressure endpoint of the continuous pressurization treatment in step (2) being 50 MPa, all other conditions are the same as in Example 1.

[0110] Example 10

[0111] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the absence of a second heating step in step (2), all other conditions are the same as in Example 1.

[0112] Example 11

[0113] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for step (2), which does not involve the fourth heating and the fifth heat preservation, the other conditions are the same as in Example 1.

[0114] Example 12

[0115] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for step (2), which does not involve the sixth heating and the seventh heat preservation, the other conditions are the same as in Example 1.

[0116] Example 13

[0117] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for step (2), which does not involve the eighth heating and the ninth heat preservation, all other conditions are the same as in Example 1.

[0118] Example 14

[0119] This embodiment provides a method for preparing a molybdenum-silicon alloy tube target. Except for the endpoint temperature of the eighth heating step (2), which is 1400℃, all other conditions are the same as in Example 1.

[0120] Comparative Example 1

[0121] This comparative example provides a method for preparing a molybdenum-silicon alloy tube target. Except for the fact that the average particle size of the molybdenum powder and silicon powder in step (1) is 6.5 μm, all other conditions are the same as in Example 1.

[0122] Comparative Example 2

[0123] This comparative example provides a method for preparing a molybdenum-silicon alloy tube target. Except for the average particle size of the molybdenum powder being 2 μm and the average particle size of the silicon powder being 6.5 μm in step (1), all other conditions are the same as in Example 1.

[0124] Comparative Example 3

[0125] This comparative example provides a method for preparing a molybdenum-silicon alloy tube target. Except for step (2), in which the bidirectional pressure mold is not equipped with a lower pressure head, i.e., the lower end face of the annular mold body is closed, all other conditions are the same as in Example 1.

[0126] The molybdenum-silicon alloy tube targets prepared in the above embodiments and comparative examples were subjected to density and purity tests. Density was tested using the Archimedes displacement method, and purity was tested using glow discharge mass spectrometry. The test results are shown in Table 1.

[0127] Table 1

[0128]

[0129] Wherein, "-" indicates that the purity of the molybdenum-silicon alloy target was not measured.

[0130] As shown in Table 1:

[0131] The preparation method provided in Examples 1-3 of this invention, by controlling the particle size range of molybdenum and silicon raw materials, combined with the use of a bidirectional pressure mold design, and finally vacuum hot pressing sintering, yields a molybdenum-silicon alloy tube target with a density ≥99% and a purity ≥99.992% under preferred conditions, exhibiting excellent sputtering performance.

[0132] A comparison of Examples 1 and 4-5, and Comparative Examples 1-2 reveals that if the average particle size of the molybdenum powder is too large, the density of the molybdenum-silicon alloy target will decrease due to the low activity caused by the large particle size; if the average particle size of the molybdenum powder is too small, the density of the molybdenum-silicon alloy target will decrease due to the uneven distribution of silicon powder around the molybdenum powder; and if the average particle size of the molybdenum powder is not greater than or equal to the average particle size of the silicon powder, the density of the molybdenum-silicon alloy target will decrease due to the uneven distribution of silicon powder around the molybdenum powder.

[0133] A comparison of Examples 1 and 6 and Comparative Example 3 shows that if the height difference between the upper and lower pressure heads and the end face of the annular mold body is too small, the density of the molybdenum-silicon alloy tube target will be significantly reduced because the displacement of the pressure head is lower than the displacement required for product densification. If the bidirectional pressure mold is not equipped with a lower pressure head, the problem of insufficient density at the bottom of the tube target cannot be solved, resulting in a decrease in the density of the molybdenum-silicon alloy tube target.

[0134] A comparison of Examples 1 and 7-9 shows that if continuous pressurization is performed from room temperature, the density of the molybdenum-silicon alloy target will decrease because no reaction driving force is provided within the reaction temperature range of molybdenum powder and silicon powder. If the final pressure of vacuum sintering hot pressing is not within the preferred range, the insufficient reaction driving force will lead to a decrease in the density of the molybdenum-silicon alloy target or product cracking.

[0135] A comparison of Examples 1 and 10-13 shows that if the second heating, fourth heating and fifth holding, sixth heating and seventh holding, or eighth heating and ninth holding are not performed, the internal structure of the molybdenum-silicon alloy tube target cannot be made to pack more tightly, thus affecting the density of the molybdenum-silicon alloy tube target.

[0136] A comparison of Examples 1 and 14 shows that if the final temperature of vacuum sintering hot pressing is too high, the molybdenum-silicon alloy tube target will liquefy because its temperature is close to the silicon powder liquefaction temperature.

[0137] 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 of producing a molybdenum-silicon alloy pipe target, characterized by, The preparation method includes: Molybdenum powder and silicon powder are mixed to form a mixed powder; The average particle size of the molybdenum powder is greater than that of the silicon powder; The mixed powder is placed in a bidirectional pressure mold and subjected to vacuum hot pressing sintering to obtain the molybdenum-silicon alloy tube target.

2. The preparation method according to claim 1, characterized in that, The atomic ratio of the molybdenum powder to the silicon powder is 1:(3~5).

3. The preparation method according to claim 1, characterized in that, The molybdenum powder has an average particle size of 6μm to 7μm. Preferably, the average particle size of the silicon powder is 1μm to 3μm.

4. The preparation method according to claim 1, characterized in that, The ratio of the mixed balls to the powder is (0.5~1.5):1; Preferably, the mixing time is ≥24h.

5. The preparation method according to claim 1, characterized in that, The bidirectional pressure mold includes an annular mold body, an upper pressure head, and a lower pressure head.

6. The preparation method according to claim 5, characterized in that, The annular mold body is provided with annular channels for accommodating mixed powder; Preferably, graphite paper is provided inside the sidewall of the annular channel; Preferably, the upper pressure head and the lower pressure head are placed independently above and below the annular channel, respectively; Preferably, both the upper and lower pressure heads are higher than the end face of the annular mold body, and the height difference is >20cm; Preferably, the widths of both the upper and lower pressure heads are the same as the width of the annular channel; Preferably, the annular mold body, the upper pressure head, and the lower pressure head are all made of graphite.

7. The preparation method according to claim 1, characterized in that, The vacuum hot pressing sintering includes sequentially performing a first heating, a second heating, a third holding, a fourth heating, a fifth holding, a sixth heating, a seventh holding, an eighth heating, and a ninth holding; Preferably, the vacuum degree of the vacuum hot pressing sintering is <10 Pa; Preferably, after the first heating and before the second heating, a continuous pressurization process is performed, and the pressure endpoint of the continuous pressurization process at the end of the ninth heat preservation is 38MPa~42MPa. Preferably, after the ninth insulation, heat preservation and pressure preservation are also performed; Preferably, the heat preservation and pressure holding time is 160 min to 200 min.

8. The preparation method according to claim 7, characterized in that, The heating rate of the first heating is 4℃ / min to 6℃ / min; Preferably, the final temperature of the first heating is 750℃~850℃; Preferably, the heating rate of the second heating is 1.5℃ / min to 2.5℃ / min; Preferably, the final temperature of the second heating is 1080℃~1120℃; Preferably, the third heat preservation time is 50 min to 70 min; Preferably, the heating rate of the fourth heating step is 0.5℃ / min to 1.5℃ / min; Preferably, the final temperature of the fourth heating step is 1180℃~1220℃; Preferably, the fifth heat preservation time is 110 min to 130 min.

9. The preparation method according to claim 7, characterized in that, The heating rate for the sixth heating step is 0.5℃ / min to 1.5℃ / min; Preferably, the final temperature of the sixth heating step is 1260℃~1280℃; Preferably, the seventh heat preservation time is 110 min to 130 min; Preferably, the heating rate of the eighth heating step is 0.5℃ / min to 1.5℃ / min; Preferably, the final temperature of the eighth heating step is 1320℃~1340℃; Preferably, the ninth heat preservation time is 50 min to 70 min.

10. A molybdenum-silicon alloy tube target, characterized in that, The molybdenum-silicon alloy tube target is prepared by the preparation method according to any one of claims 1-9; The density of the molybdenum-silicon alloy target is ≥99%; The wall thickness of the molybdenum-silicon alloy tube target is ≤7mm and the length is ≥100mm.

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