Titanium target for sputtering, method for producing same, and method for producing titanium-containing thin film

Abstract

The invention provides a titanium target for sputtering, a method for producing the same, and a method for producing a titanium-containing thin film. Specifically disclosed is a titanium target for sputtering, which has a recrystallized structure having an average crystal grain size of 1 [mu] m or less. In addition, the present invention also provides a method for manufacturing a titanium target for sputtering, the method comprising: a step for obtaining a processed plate by performing large strain processing on a cut titanium ingot; a step for obtaining a rolled sheet by cold-rolling the processed sheet at a rolling rate of 30% or more; and a step for heat-treating the rolled sheet at a temperature of 320 DEG C or less.

Description

[0001] This invention is a divisional application of Chinese PCT patent application number 201880060970.7, entitled "Titanium target for sputtering and method for manufacturing the same, and method for manufacturing titanium-containing thin film", with an international filing date of July 13, 2018. Technical Field

[0002] This invention relates to a titanium target for sputtering and a method for manufacturing the same, as well as a method for manufacturing titanium-containing thin films. More specifically, this invention relates to: a titanium target for sputtering used as a sputtering source and a method for manufacturing the same, said sputtering source being used to form various thin films (e.g., electrodes, gates, wiring, components, insulating films, protective films) in various electronic devices such as semiconductor devices; and a method for manufacturing titanium-containing thin films. Background Technology

[0003] In recent years, with the miniaturization and high integration of semiconductor devices, there is a growing demand for thinner and more refined thin films in these devices. Molybdenum, tungsten, and titanium are among the materials used for thin films, with titanium seeing increased application due to its excellent strength, processability, and corrosion resistance. Furthermore, sputtering is a common method for forming thin films, using a titanium target as the sputtering source (thin film material).

[0004] During sputtering, an inert gas (e.g., Ar) is simultaneously introduced under vacuum, and a high voltage is applied between the substrate and the titanium target to ionize the Ar. + Plasma collides with a titanium target, releasing titanium atoms through the collision energy and causing them to accumulate on a substrate, thereby forming a titanium-containing thin film. In this case, when forming a titanium nitride thin film as the titanium-containing film, a mixture of argon and nitrogen gas is used.

[0005] Recently, in order to improve production efficiency, high-speed sputtering (high-power sputtering) is required even in sputtering. However, existing titanium targets sometimes crack or split under such high-load conditions as high-speed sputtering, which becomes a major factor hindering stable sputtering.

[0006] In addition, there is a problem that particles and nodules are easily generated during sputtering. Therefore, efforts are being made to reduce impurities in the titanium target. However, since there are limits to the reduction of impurities, this problem cannot be fundamentally solved yet.

[0007] Therefore, in Patent Document 1, to solve the above problems, a material with a purity of 5N5 (99.9995%) or higher, no large patterns on the surface, and an average crystal grain size of 10 mm in the recrystallized structure was proposed. μ Titanium targets with a diameter of less than m.

[0008] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 6077102. Summary of the Invention

[0009] The problem the invention aims to solve The titanium target in Patent Document 1, due to its high purity, can suppress particle generation during sputtering. However, in practice, the average grain size of the recrystallized structure of the titanium target in Patent Document 1 is at least 8 mm. μ Approximately 1.5 μm. If the average crystal grain size of the recrystallized structure is large, the particles are prone to accumulate on the surface after pre-firing, or nodules are easily formed. Therefore, considering the technical level required in the future, it is desirable to refine the crystal grain size of the recrystallized structure to further improve the effect of suppressing the formation of particles and nodules.

[0010] Furthermore, future plans envision sputtering under even higher load conditions, so even the titanium target in Patent Document 1 cannot be considered sufficiently effective in suppressing cracking or fissures during sputtering.

[0011] The embodiments of the present invention are proposed to solve the problems described above, and their purpose is to provide a titanium target for sputtering that can not only suppress cracking or crazing during sputtering, but also suppress the generation of particles and nodules, and a method for manufacturing the same.

[0012] Problem-solving methods To address the aforementioned problems, the inventors conducted in-depth research and discovered that the cracking or splitting of the titanium target used in sputtering is related to the strength of the titanium target. This was achieved by setting the average crystal grain size of the recrystallized structure to 1... μ Below m, it can improve the strength of titanium targets used for sputtering and suppress cracking or crazing during sputtering.

[0013] Furthermore, the inventors discovered that the generation of particles and nodules during sputtering is related to the average crystal grain size of the recrystallized structure. This was achieved by setting the average crystal grain size of the recrystallized structure to 1. μ Below m, it can inhibit the formation of granules and nodules.

[0014] Furthermore, the inventors have discovered that by optimizing the manufacturing conditions, the average grain size of the recrystallized structure of the titanium target for sputtering can be controlled within 1 mm. μ Below m.

[0015] The embodiments of the present invention are based on the above understanding.

[0016] That is, the titanium target for sputtering involved in the embodiments of the present invention has an average crystal grain size of 1. μ Recrystallized structures below m.

[0017] Furthermore, the method for manufacturing a titanium target for sputtering according to the embodiments of the present invention includes the following steps: a step of performing large strain processing on a cut titanium ingot to obtain a processing plate; a step of cold rolling the processing plate at a rolling rate of 30% or more to obtain a rolled plate; and a step of heat treating the rolled plate at a temperature of 320°C or below.

[0018] Furthermore, the method for manufacturing titanium-containing thin films according to the embodiments of the present invention uses the above-mentioned titanium target for sputtering as the sputtering source.

[0019] The effects of the invention According to embodiments of the present invention, a titanium target for sputtering that can not only suppress cracking or fissures during sputtering, but also suppress the generation of particles and nodules, and a method thereof can be provided. Attached Figure Description

[0020] Figure 1 This is a comparison of optical microscope images (500x) of the titanium targets of Example 2 and Comparative Examples 1-3.

[0021] Figure 2 This is a comparison of SEM images (10,000x magnification) of the titanium targets from Examples 1 and 2.

[0022] Figure 3 This is a comparison of optical microscope photographs (500x) of the titanium targets of Comparative Examples 1, 2, 4 and 5.

[0023] Figure 4 This is a comparison image of optical microscope photographs (200x) of the titanium targets of Comparative Examples 6-8.

[0024] Figure 5 This is a comparison of optical microscope images (100x) of the titanium targets in Comparative Examples 4, 9 and 10.

[0025] Figure 6 These are grain boundary images of the titanium targets in Examples 1 and 2 obtained by electron backscatter diffraction (EBSD) analysis. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described in detail below. However, the present invention should not be interpreted in a limited manner by these embodiments. Various changes and improvements can be made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Various inventions can be formed by appropriately combining the multiple constituent elements disclosed in each embodiment. For example, several constituent elements can be deleted from all the constituent elements disclosed in the embodiments, and constituent elements of different embodiments can also be appropriately combined.

[0027] The titanium target (hereinafter sometimes simply referred to as "titanium target") for sputtering according to embodiments of the present invention has an average crystal grain size of 1. μ Recrystallized structures below m.

[0028] Here, "average crystal grain size" in this specification refers to the grain size obtained by measuring the average segment length of each grain within a test line transversely cut across the surface of the titanium target (sputtered surface) according to the cutting method of JIS G0551:2013. In the observation of grains using this method, EBSD measurement (region 10) can be employed. μ m×10 μ m, multiplier of 10000, etc.

[0029] The initial surface of a titanium target is smooth, but after pre-firing (a process used to stabilize the target's properties), the surface becomes rough. The larger the average grain size of the recrystallized structure, the rougher the surface of the pre-firing titanium target, leading to particle accumulation or nodule formation. The smallest average grain size of the recrystallized structure in existing titanium targets is 8 mm. μ The titanium target has a diameter of approximately 1.5 μm, therefore, compared with existing titanium targets, the titanium target involved in the embodiments of the present invention has a higher effect on suppressing the generation of particles and nodules during sputtering.

[0030] Furthermore, the smaller the average grain size of the recrystallized structure of the titanium target, the higher its strength. In fact, it is known that according to the Hall-Petch equation, the smaller the grain size, the higher the yield stress (strength). Compared to existing titanium targets, the titanium target according to the embodiments of the present invention has improved strength due to its small average grain size in its recrystallized structure. As a result, the titanium target according to the embodiments of the present invention is more effective at suppressing cracking or spalling during sputtering compared to existing titanium targets.

[0031] The Vickers hardness of the titanium target involved in the embodiments of the present invention is not particularly limited, but preferably 140 Hv or higher, more preferably 140 Hv to 250 Hv, and even more preferably 150 Hv to 200 Hv. Here, "Vickers hardness of titanium target" in this specification refers to the hardness obtained on the surface of titanium target (sputtered surface) by means of the Vickers hardness test method according to JIS Z2244:2009.

[0032] From the viewpoint of consistently obtaining the effects produced by the embodiments of the present invention described above, the average crystal grain size of the recrystallized structure is preferably 0.9 mm. μ Below m, more preferably 0.1 μ m~0.8 μ m, more preferably 0.2 μ m~0.7 μ m.

[0033] The titanium target according to the embodiments of the present invention improves the effect of suppressing the formation of particles and nodules during sputtering by reducing the average crystal grain size of the recrystallized structure; therefore, its purity is not particularly limited. However, this effect can be further improved by increasing the purity of the titanium target. Therefore, the purity of the titanium target according to the embodiments of the present invention is preferably 4N (99.99% by mass) or more, more preferably 4N5 (99.995% by mass) or more, even more preferably 5N (99.999% by mass) or more, and most preferably 5N5 (99.9995% by mass) or more.

[0034] Here, a purity of 4N (99.99% by mass) or higher for the titanium target means that, when performing compositional analysis by glow discharge mass spectrometry (GDMS), the total amount of elements other than titanium (such as Na, Al, Si, K, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, etc.) in the titanium target does not reach 0.01% by mass (100 ppm by mass).

[0035] The titanium target according to the embodiments of the present invention having the above-described features can be manufactured by a method including the following steps: a step of performing large strain processing on a cut titanium ingot to obtain a processed plate (hereinafter sometimes simply referred to as the "large strain processing step"); a step of cold rolling the processed plate at a rolling rate of 30% or more to obtain a rolled plate (hereinafter sometimes simply referred to as the "rolling step"); and a step of heat treating the rolled plate at a temperature of 320°C or below (hereinafter sometimes simply referred to as the "heat treatment step"). There are no particular limitations on the steps other than those described above, as long as they are performed according to known methods.

[0036] The greater the strain before recrystallization, the smaller the grain size of the recrystallized structure tends to be. Therefore, in the forging process, large strain processing (also known as "giant strain processing") is used to refine the grain size. Large strain processing is not particularly limited and can include multi-axis forging, ECAP, HPT, and ARB methods. Among these, multi-axis forging is preferred as a large strain processing method considering factors such as processing speed, strain uniformity, dimensional variability, necessity of investing in new equipment, and cost. Furthermore, since multi-axis forging involves forging along multiple axes and applying large strain by increasing the number of cycles, it simultaneously changes the axes and performs forging, thus reducing the risk of kneading cracks compared to methods like kneading forging.

[0037] Furthermore, in the high-strain processing step, even when the strain before recrystallization is small, the crystallinity of the recrystallized structure can be reduced by lowering the processing temperature. Therefore, the processing temperature is preferably adjusted according to the total strain (Δε) of the processed plate. For example, when the total strain of the processed plate is around 2, the crystallinity of the recrystallized structure can be reduced by setting the processing temperature to around room temperature.

[0038] The processing temperature in the large strain processing step is not particularly limited, but from the perspective of stable strain accumulation, it is preferably below 500°C, more preferably room temperature to 450°C, and even more preferably 200°C to 400°C. When the processing temperature is too high, the strain is mitigated by dynamic recrystallization during processing, and as a result, the average crystal grain size of the recrystallized structure after the heat treatment step tends to increase.

[0039] The total strain (Δε) of the processed plate obtained through the large strain processing step is not particularly limited. However, from the perspective of steadily reducing the crystal grain size of the recrystallized structure, a strain of 2 or more is preferred, more preferably more than 3 and less than 15, and even more preferably more than 5 and less than 13. When the total strain of the processed plate is too small, the average crystal grain size of the recrystallized structure of the final titanium target tends to increase.

[0040] In this specification, for example, when the large strain processing is multi-axis forging, "the total strain (Δε) of the processed plate obtained through the large strain processing steps" can be expressed by the following formula.

[0041]

Mathematical Formula 1

[0042] In the formula, n is the number of cycles in multi-axis forging, and h 0k h represents the longitudinal thickness of the material before the k-th processing step. k The thickness of the longitudinal portion of the material before the k-th processing step is the thickness after processing. Here, the number of cycles in multi-axis forging is defined as three pressurizations performed in each of the three axial directions (x, y, and z) for a total of three pressurizations, which constitute one cycle.

[0043] For example, in the case of multi-axis forging for high-strain processing, the total strain of the processed plate can be controlled by adjusting the number of cycles in multi-axis forging and the strain per press. For example, by adjusting the strain per press to 0.2 and the number of cycles to 15, the total strain of the forged plate can be controlled at 9.

[0044] The titanium ingots used in the large strain processing step are not particularly limited and can be manufactured using methods known in the art. However, considering the effect of further improving the suppression of particle and nodule formation during sputtering, the purity of the titanium ingot is preferably 4N (99.99% by mass) or higher, more preferably 4N5 (99.995% by mass) or higher, even more preferably 5N (99.999% by mass) or higher, and most preferably 5N5 (99.9995% by mass) or higher. Here, the purity of the titanium ingot is 4N (99.99% by mass) or higher, which means that when the composition is analyzed by glow discharge mass spectrometry (GDMS), the total amount of elements other than titanium (e.g., Na, Al, Si, K, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, etc.) does not reach 0.01% by mass (100 ppm by mass).

[0045] Furthermore, in manufacturing high-purity titanium targets with a purity of 5N5 (99.9995% by mass) or higher, high-purity titanium material obtained through molten salt electrolysis is dissolved by electron beam (EB) and then cooled and solidified to obtain high-purity titanium ingots. Here, it is preferable to set the molten salt electrolysis environment to an inactive environment and to set the initial cathode current density during electrolysis to a low current density of 0.6 A / cm². 2 The electrolysis temperature is set to 600℃~800℃.

[0046] Secondly, in the rolling step, the processed sheet obtained through the large strain processing step is cold-rolled. Experiments have shown that if the rolling ratio is too small when cold-rolling the processed sheet, the average grain size of the recrystallized structure after the heat treatment step tends to increase. Therefore, in the embodiments of the present invention, the average grain size of the recrystallized structure is controlled to be within 1... μ Considering aspects below m, the rolling rate of cold rolling is specified to be above 30%. If the rolling rate of cold rolling is less than 30%, the average grain size of the recrystallized structure will exceed 1. μ Without this method, the effects of the embodiments of the present invention cannot be obtained. Furthermore, from the perspective of stably controlling the average crystal grain size of the recrystallized structure, the rolling rate of cold rolling is preferably 50% or more, more preferably 60% or more, and even more preferably over 70%. There is no particular upper limit to the rolling rate of cold rolling, but 95% is preferred, and 90% is more preferred.

[0047] Regarding various conditions during cold rolling (such as number of passes and roll speed), there are no particular limitations as long as they are set appropriately according to the equipment used to obtain the specified rolling yield. Furthermore, the temperature during cold rolling can be within a general range and is not particularly limited; room temperature is typically used.

[0048] Secondly, in the heat treatment step, the rolled sheet obtained through the rolling step is heat-treated. Experiments have shown that when heat-treating the rolled sheet, the lower the heat treatment temperature, the finer the crystal grain size tends to be. Therefore, in the embodiments of the present invention, the average crystal grain size of the recrystallized structure is controlled to be within 1... μ Considering factors below 1 μm, the heat treatment temperature for rolled steel sheets is specified to be below 320℃. If the heat treatment temperature of rolled steel sheets exceeds 320℃, the average grain size of the recrystallized structure will exceed 1 μm. μ m, the effects of the embodiments of the present invention cannot be obtained. In addition, from the viewpoint of stably controlling the average crystal grain size of the recrystallized structure, the heat treatment temperature of the rolled plate is preferably 250°C to 320°C, more preferably 260°C to 320°C.

[0049] In addition, the heat treatment time can be set appropriately according to the size of the rolled plate, etc., and there is no particular limitation. It is usually 20 minutes to 60 minutes, preferably 30 minutes to 50 minutes.

[0050] The heat-treated plate (titanium target) obtained through the heat treatment process is then subjected to surface processing and other treatments before being diffuse-bonded to the back plate for use.

[0051] The titanium target manufactured by the above operation has an average crystal grain size of 1. μ The recrystallized structure below μm not only suppresses cracking or fissures during sputtering, but also inhibits the formation of particles and nodules. Therefore, this titanium target can be used as a sputtering source for forming titanium-containing thin films, especially suitable for high-speed sputtering (high-power sputtering) under higher load conditions.

[0052] Example Hereinafter, embodiments and comparative examples will be used to describe in detail the implementation of the present invention, but the present invention is not limited to these examples.

[0053] (Example 1) Titanium ingots with a purity of 4N5 (99.995% by mass) were cut for high-strain processing. As a high-strain process, multi-axis forging was performed at a forging temperature of 400°C and 15 cycles. The total strain (Δε) of the resulting forged sheet (processed sheet) was 9. Next, the forged sheet was cold-rolled at room temperature with a rolling rate of 85% at a pass rate of 16 and a roll speed of 10 m / min to obtain a rolled sheet. Then, the rolled sheet was heat-treated at 270°C for 40 minutes to obtain a heat-treated sheet (titanium target).

[0054] (Example 2) Except for changing the heat treatment temperature to 300°C, the titanium target was obtained under the same conditions as in Example 1.

[0055] (Example 3) The titanium target was obtained under the same conditions as in Example 1, except that a titanium ingot with a purity of 3N5 (99.95% by mass) was used.

[0056] (Example 4) A titanium target was obtained under the same conditions as in Example 1, except that a titanium ingot with a purity of 4N85 (99.9985% by mass) was used and the heat treatment temperature was changed to 320°C.

[0057] (Example 5) The titanium target was obtained under the same conditions as in Example 1, except that a titanium ingot with a purity of 5N5 (99.9995% by mass) was used.

[0058] (Comparative Example 1) Except for changing the heat treatment temperature to 350°C, the titanium target was obtained under the same conditions as in Example 1.

[0059] (Comparative Example 2) Except for changing the heat treatment temperature to 400°C, the titanium target was obtained under the same conditions as in Example 1.

[0060] (Comparative Example 3) Except for changing the heat treatment temperature to 455°C, the titanium target was obtained under the same conditions as in Example 1.

[0061] (Comparative Example 4) A rolled sheet was obtained by cold rolling the forged sheet at room temperature with a rolling rate of 70% and a pass rate of 16 and a roll speed of 10 m / min. Otherwise, a titanium target was obtained under the same conditions as in Comparative Example 1.

[0062] (Comparative Example 5) A rolled sheet was obtained by cold rolling the forged sheet at a rolling rate of 70% at room temperature with a pass rate of 16 and a roll speed of 10 m / min. Otherwise, a titanium target was obtained under the same conditions as in Comparative Example 2.

[0063] (Comparative Example 6) Titanium ingots with a purity of 4N5 were cut and multi-axis forged at a forging temperature of 600℃ with 15 cycles. The total strain of the resulting forged plate was 9. Next, the forged plate was heat-treated at 455℃ for 40 minutes to obtain a titanium target.

[0064] (Comparative Example 7) The forging temperature was changed to 400°C and the number of cycles was changed to 5. A forged plate with a total strain of 3 was produced. Otherwise, a titanium target was obtained under the same conditions as Comparative Example 6.

[0065] (Comparative Example 8) Except for changing the forging temperature to 400°C, a titanium target was obtained under the same conditions as Comparative Example 6.

[0066] (Comparative Example 9) Multi-axis forging was performed with a forging temperature of 600°C and a cycle number of 15 to obtain a forged plate with a total strain of 9. Otherwise, a titanium target was obtained under the same conditions as in Comparative Example 4.

[0067] (Comparative Example 10) The forging temperature was set to 400°C and the number of cycles was set to 5. Multi-axis forging was performed to obtain a forged plate with a total strain of 3. Otherwise, a titanium target was obtained under the same conditions as Comparative Example 4.

[0068] For the titanium targets obtained in the above embodiments and comparative examples, the average crystal grain size of the recrystallized structure was determined according to the method described above, and the amounts of elements other than titanium were determined by glow discharge mass spectrometry (GDMS). The results of the average crystal grain size of the recrystallized structure and the manufacturing conditions are shown together in Table 1. In addition, the results obtained by glow discharge mass spectrometry are shown in Table 2.

[0069] [Table 1]

[0070] [Table 2]

[0071] As shown in Table 1, the titanium targets of Examples 1-5, manufactured by cold rolling at a rolling rate of over 30% in the rolling step and heat treatment at a temperature below 320°C in the heat treatment step after large strain processing, have an average grain size of 1 mm in their recrystallized structure. μ Below 1 μm. In contrast, the titanium targets of Comparative Examples 1-10 had an average grain size exceeding 1 μm due to at least one unsuitable condition in the rolling and heat treatment steps. μ m, or the recrystallized structure has not fully formed.

[0072] In addition, the titanium targets of Examples 1 to 5 have higher Vickers hardness compared with the titanium targets of Comparative Examples 1 to 10.

[0073] Furthermore, as shown in Table 2, it was confirmed that the total amount of elements other than titanium contained in the titanium targets of Examples 1 to 5 did not reach 100 ppm by mass, and had a purity of 4N or higher.

[0074] Next, the surfaces of several titanium targets obtained in the examples and comparative examples were observed using an optical microscope and SEM.

[0075] The illustration shows a comparison of optical microscope images (500x) of the titanium targets of Example 2 and Comparative Examples 1-3. Figure 1 Additionally, a comparative illustration shows SEM images (10000x magnification) of the titanium targets from Examples 1 and 2. Figure 2 Furthermore, in Figure 1 In the middle, the number in the upper right corner is the average crystal grain size of the recrystallized structure.

[0076] like Figure 1 and Figure 2 As shown, as the heat treatment temperature decreases in the heat treatment step, the crystal grain size of the recrystallized structure tends to become finer.

[0077] Figure 3 This figure shows optical microscope images (500x) of the titanium targets of Comparative Examples 1, 2, 4 and 5 for comparison.

[0078] Depend on Figure 3 It can be seen that as the rolling rate increases in the rolling step, the crystal grain size of the recrystallized structure tends to become finer. Furthermore, as the heat treatment temperature decreases in the heat treatment step, the crystal grain size of the recrystallized structure tends to become finer.

[0079] Figure 4 This figure shows optical microscope images (200x) of the titanium targets of Comparative Examples 6-8 for comparison.

[0080] Depend on Figure 4 It can be seen that, without cold rolling, during the large strain processing step, as the total strain (Δε) of the forged plate decreases, the recrystallized structure becomes inhomogeneous, and the grain size of the recrystallized structure tends to become coarser. Furthermore, during the large strain processing step, as the forging temperature (processing temperature) increases, the grain size of the recrystallized structure tends to become coarser.

[0081] Figure 5 This figure shows a comparison of optical microscope images (100x) of the titanium targets of Comparative Examples 4, 9 and 10.

[0082] Depend on Figure 5 It can be seen that even in the case of cold rolling, during the high-strain processing step, as the total strain (Δε) of the forged plate decreases, there is a tendency to form portions that do not form recrystallized structures. Furthermore, during the high-strain processing step, as the processing temperature increases, the grain size of the recrystallized structure tends to become coarser, and there is also a tendency to form portions that do not form recrystallized structures.

[0083] Secondly, the grain boundaries of the surface microstructure of the titanium targets in Examples 1 and 2 were observed by electron backscatter diffraction (EBSD) analysis. The resulting grain boundary images are shown below. Figure 6Furthermore, the EBSD utilizes a JSM-7001F TTLS type electric field emission scanning electron microscope manufactured by JEOL Corporation, combined with an OIM6.0-CCD / BS type crystal orientation analysis device. (Select 10) μ m×10 μ An arbitrary surface region of m was observed at a magnification of 10000.

[0084] Depend on Figure 6 It can be seen that the titanium targets in Examples 1 and 2 have recrystallized structures with both large-angle and small-angle grain boundaries. Here, large-angle grain boundaries refer to grain boundaries with an azimuth difference of 15° or more, while small-angle grain boundaries refer to grain boundaries with an azimuth difference of less than 15°.

[0085] Industrial practicality According to embodiments of the present invention, a titanium target for sputtering and a method thereof can be provided that can not only suppress cracking or fissures during sputtering, but also suppress the formation of particles and nodules. Therefore, the titanium target for sputtering according to embodiments of the present invention can be used as a sputtering source for forming various thin films (e.g., electrodes, gates, wiring, components, insulating films, protective films) in various electronic devices such as semiconductor devices, and is particularly suitable for high-speed sputtering (high-power sputtering) under higher load conditions.

Claims

1. A titanium target for sputtering, having a recrystallized structure with an average crystal grain size of less than 1 μm, a purity of 4N (i.e., 99.99% by mass) or higher, and a Vickers hardness of 140 Hv or higher.

2. A method for manufacturing a titanium-containing thin film, wherein the titanium target for sputtering as described in claim 1 is used as the sputtering source.

3. A method for manufacturing a titanium target for sputtering, comprising the following steps: The steps of strain processing cut titanium ingots with a purity of 4N (i.e., 99.99% by mass) or higher to obtain a processed plate with a total strain of 2 or higher; The steps of cold rolling the processed sheet with a rolling rate of 30% or more to obtain a rolled sheet; and The step of heat-treating the rolled plate at a temperature below 320°C.

4. The method for manufacturing a titanium target for sputtering according to claim 3, wherein, The processing temperature in the strain processing is below 500℃.

5. The method for manufacturing a titanium target for sputtering according to claim 3, wherein, The strain processing is multi-axis forging.

6. The method for manufacturing a titanium target for sputtering according to claim 4, wherein, The strain processing is multi-axis forging.

7. The method for manufacturing a titanium target for sputtering according to any one of claims 3 to 6, wherein, The rolling rate in the cold rolling process exceeds 70%.

8. The method for manufacturing a titanium target for sputtering according to any one of claims 3 to 6, wherein, The total strain of the processed plate exceeds 3.

9. The method for manufacturing a titanium target for sputtering according to claim 7, wherein, The total strain of the processed plate exceeds 3.

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