Highly Dispersed Spherical Ruthenium Powder with a Particle Size Less than 1 μm, Its Preparation Method and Application

Abstract

The present invention discloses high-dispersion spherical ruthenium powder with a particle size less than 1 μm, its preparation method and application, solving the problem of preparing high-dispersion spherical ruthenium powder with uniform and fine particle size and controllable particle size. When preparing the ruthenium powder, a high-dispersion spherical precursor precipitate powder with controllable particle size is obtained by regulating the molar ratio of sulfate radical to ruthenium ion in the solution, and then the precursor precipitate powder is placed in hydrogen for high-temperature calcination to obtain high-dispersion spherical ruthenium powder with a particle size less than 1 μm. The technology of the present invention is novel, and can realize the large-scale preparation of high-dispersion spherical ruthenium powder with a particle size less than 1 μm. The ruthenium powder prepared by this method has broad application prospects in the field of semiconductor sputtering targets.

Description

Technical Field

[0001] The present invention relates to ruthenium powder with a particle size less than 1 μm, high dispersion, and spherical shape, its preparation method and application, belonging to the fields of precious metals and semiconductor sputtering targets. Background Art

[0002] Products in the semiconductor industry such as integrated circuits and chips generally have a multi-layer film structure. By magnetron sputtering to bombard the sputtering target, thin films of different materials are sputtered on the substrate to meet the usage requirements of each semiconductor industry. Ruthenium, due to its low resistivity and high chemical stability, can play a role in reducing the interfacial stress in the multi-layer film structure of recording materials and improving the thermal stability of the overall component, which is crucial in the field of integrated circuits in the information industry.

[0003] As a raw material for coating, sputtering targets are developing towards high purity, high density, small and uniform grains. Targets are often prepared by powder metallurgy, and the properties of raw material powders affect the properties of the final sputtering targets. Spherical powders are easy to form a higher packing density and are more likely to obtain a higher density during subsequent forming and sintering processes. Uniform and fine grains in the target can improve the sputtering rate and coating uniformity of the target. Therefore, there is a greater need for raw material powders with small and uniform particle size. The preparation of ruthenium powder with high dispersion, spherical shape, and uniform and fine particle size is one of the technical bottlenecks in the preparation of high-performance targets.

[0004] Generally, ruthenium powder is prepared by a chemical method, that is, reacting a ruthenium-containing salt with an alkaline or strongly reducing substance to directly precipitate metal ruthenium powder or a ruthenium powder precursor product. This process is difficult to control the uniform progress of the reaction and cannot control the particle size and powder morphology of the product. At the same time, as the particle size of the powder decreases, it is easier to agglomerate. Usually, a dispersant such as PVP is introduced during the reaction process to prevent powder agglomeration. The use of dispersants will reduce the purity of the powder.

[0005] With the development of technology and industry, there is an urgent need to develop a preparation method for ruthenium powder with spherical shape, high dispersion, and uniform and fine particle size. The existing technologies cannot solve this technical problem. The present invention provides a preparation method for ruthenium powder with high dispersion, spherical shape, and a particle size less than 1 μm, solving the problem of high-performance raw material powders required for the preparation of high-performance ruthenium sputtering targets. Summary of the Invention

[0006] In order to solve the above problems, the present invention proposes to regulate the concentration ratio of sulfate ions to ruthenium ions in the solution, and then regulate the morphology, particle size and dimension of the precipitated powder, and then combine high-temperature calcination with hydrogen to obtain ruthenium powder with high dispersion and spherical shape. The technology is novel, and ruthenium powder with high dispersion and spherical shape and a particle size less than 1 μm is successfully prepared. The present invention is an important technological innovation.

[0007] The present invention provides highly dispersed spherical ruthenium powder with a particle size less than 1 μm, and a preparation method and application thereof. The ruthenium powder includes Class I ruthenium powder, Class II ruthenium powder, Class III ruthenium powder, Class IV ruthenium powder, and Class V ruthenium powder:

[0008] When preparing the Class I ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.25 - 0.5, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.05 - 0.15 μm;

[0009] When preparing the Class II ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.5 - 0.75, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.1 - 0.25 μm;

[0010] When preparing the Class III ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.75 - 1.25, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.2 - 0.4 μm;

[0011] When preparing the Class IV ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 1.25 - 2, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.3 - 0.5 μm;

[0012] When preparing the Class V ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 2 - 5, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.4 - 0.6 μm;

[0013] The above highly dispersed spherical precursor precipitate powders are respectively calcined at high temperature with hydrogen to obtain highly dispersed spherical ruthenium powder with a particle size less than 1 μm.

[0014] Furthermore, in the above technical solution, a reaction solution containing ruthenium ions and sulfate ions is prepared, urea is added to the reaction solution, the solution is homogenized at room temperature, and then the temperature is raised for reaction to generate a precipitate under stirring. After cooling, the precipitate is filtered, washed, and dried to obtain a highly dispersed spherical precursor precipitate powder; the particle size range of the highly dispersed spherical precursor precipitate powder is 0.05 - 0.6 μm. The highly dispersed spherical precursor precipitate powder is calcined in a hydrogen atmosphere to obtain highly dispersed spherical ruthenium powder with a particle size less than 1 μm.

[0015] Further, in the above technical solution, the concentration of ruthenium ions in the reaction solution is 0.0001 - 0.1 mol / L; preferably 0.0005 - 0.05 mol / L; more preferably 0.0005 - 0.005 mol / L, and the molar ratio of sulfate ions to ruthenium ions is 0.25 - 5.

[0016] Further, in the above technical solution, the molar ratio of urea to ruthenium ions is 1 - 50; preferably 1 - 30; more preferably 20 - 30, the homogenization treatment time is 1 - 2 h, the temperature for the precipitation reaction is 80 - 100 °C; preferably 85 - 95 °C, and the precipitation reaction time is 10 - 300 min; preferably 120 - 300 min; more preferably 120 - 180 min.

[0017] Further, in the above technical solution, in the high-temperature calcination process with hydrogen, the calcination temperature is 200 - 800 °C; preferably 200 - 600 °C; more preferably 250 - 500 °C; and the calcination time is 10 - 120 min; preferably 30 - 120 min; more preferably 30 - 90 min.

[0018] Further, in the above technical solution, the sulfate ions are selected from one or more of sulfuric acid, ammonium sulfate, and ammonium bisulfate.

[0019] Further, in the above technical solution, the ruthenium ions are selected from one or more of ruthenium trichloride, ammonium chlororuthenate, ruthenium sulfate, and ruthenium nitrate.

[0020] The present invention provides ruthenium powder with a particle size less than 1 μm, high-dispersion spherical shape obtained by the above method. The ruthenium powder is spherical, with a particle size less than 1 μm, a narrow particle size distribution range, high particle size dispersion, and controllability.

[0021] The present invention provides the above ruthenium powder, which can be used as a raw material for sputtering targets in the field of information storage.

[0022] Advantages of the Invention

[0023] The preparation of ruthenium powder with high dispersion, spherical shape, and uniform and fine particle size is one of the technical bottlenecks in the preparation of high-performance ruthenium targets. The present invention provides a method for preparing ruthenium powder with a particle size less than 1 μm, high-dispersion spherical shape, which solves the problem of high-performance raw material powder required for the preparation of high-performance ruthenium sputtering targets. The prepared ruthenium powder has a particle size less than 1 μm, is spherical, has controllable particle size, a narrow particle size distribution, and high dispersion. Description of the Drawings

[0024] Figure 1 It is the SEM image of the precursor precipitate powder prepared in Comparative Example 1;

[0025] Figure 2 It is the SEM image of the ruthenium powder prepared in Comparative Example 1;

[0026] Figure 3 It is the SEM image of the precursor precipitation powder prepared in Comparative Example 2;

[0027] Figure 4 It is the SEM image of the ruthenium powder prepared in Comparative Example 2;

[0028] Figure 5 It is the SEM image of the precursor precipitation powder prepared in Example 1;

[0029] Figure 6 It is the SEM image of the ruthenium powder prepared in Example 1;

[0030] Figure 7 It is the XRD pattern of the ruthenium powder prepared in Example 1;

[0031] Figure 8 It is the SEM image of the precursor precipitation powder prepared in Example 2;

[0032] Figure 9 It is the SEM image of the ruthenium powder prepared in Example 2;

[0033] Figure 10 It is the XRD pattern of the ruthenium powder prepared in Example 2. Detailed implementation manners

[0034] The present invention will be further described below with reference to the accompanying drawings. The following examples are only for understanding the present invention and do not limit the present invention.

[0035] Comparative Example 1

[0036] 1. Weigh 1.04 g of ruthenium trichloride and dissolve it in a beaker containing 400 ml of deionized water to prepare a ruthenium ion-containing solution.

[0037] 2. Add 7.51 g of urea to the ruthenium trichloride solution, then make up the volume of the solution to 1000 ml with deionized water, stir well to make the solution evenly mixed, and then continuously stir the solution at room temperature for homogenization treatment for 1 h.

[0038] 3. Heat the homogenized solution to 90 °C with stirring, keep it warm for 180 min, then let the solution cool naturally, filter, wash, and dry the precipitate to obtain the precursor precipitation powder. The morphology of the obtained precursor precipitation powder is shown in Figure 1 , and the powder is severely agglomerated, and the powder morphology is flocculent.

[0039] 4. Place the precursor precipitation powder in an alumina crucible, place it in a hydrogen furnace, keep it warm at 500 °C in hydrogen for 60 min, and then cool it with the furnace after the heat preservation is over to obtain ruthenium powder. The morphology of the obtained ruthenium powder is shown in Figure 2 , and the powder is severely agglomerated and has an irregular morphology.

[0040] Comparative Example 2

[0041] 1. Dissolve 1.04 g of ruthenium trichloride in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and dissolve 3.96 g of ammonium sulfate in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0042] 2. Mix the ruthenium ion-containing solution and the sulfate ion-containing solution. The molar ratio of sulfate ions to ruthenium ions in the solution is 6. Add 7.51 g of urea to the mixed solution, then dilute the solution to 1000 ml with deionized water, stir well to make the solution uniformly mixed, and then continuously stir the solution at room temperature for homogenization for 1 h.

[0043] 3. Heat the homogenized solution to 80 °C with stirring, keep it warm for 120 min, then let the solution cool naturally. Filter, wash, and dry the precipitate to obtain the precursor precipitate powder. The morphology of the obtained precursor precipitate powder is shown in Figure 3 , the powder is in an aggregated state, the morphology is spherical, and the particle size range of the powder is 0.5 - 0.6 μm.

[0044] 4. Place the precursor precipitate powder in an alumina crucible, place it in a hydrogen furnace, keep it warm at 350 °C in hydrogen for 30 min, and then cool it with the furnace after the heat preservation to obtain ruthenium powder. The morphology of the obtained ruthenium powder is shown in Figure 4 , the ruthenium powder has a particle size less than 1 μm, the distribution range is 0.25 - 0.45 μm, the powder morphology is spherical, and the particle size uniformity of the powder is poor and agglomeration occurs at the same time.

[0045] Example 1

[0046] 1. Dissolve 1.04 g of ruthenium trichloride in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and dissolve 0.33 g of ammonium sulfate and 25 ml of 0.1 mol / L sulfuric acid in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0047] 2. Mix the ruthenium ion-containing solution and the sulfate ion-containing solution. The molar ratio of sulfate ions to ruthenium ions in the mixed solution is 1. Add 7.51 g of urea to the mixed solution, then dilute the solution to 1000 ml with deionized water, stir well to make the solution uniformly mixed, and then continuously stir the solution at room temperature for homogenization for 1 h.

[0048] 3. Heat the homogenized solution to 85 °C with stirring, keep it warm for 120 min, then let the solution cool naturally. Filter, wash, and dry the precipitate to obtain the precursor precipitate powder. The morphology of the obtained precursor precipitate powder is shown in Figure 5 , the powder is highly dispersed, the powder morphology is spherical, and the particle size range of the powder is 0.2 - 0.4 μm.

[0049] 4. Place the precursor precipitate powder in an alumina crucible and place it in a hydrogen furnace. Keep it at 450 °C in hydrogen for 60 min, and then cool it with the furnace after the insulation is completed to obtain ruthenium powder. The morphology of the obtained ruthenium powder is shown in Figure 6 , the particle size of the ruthenium powder is less than 1 μm, and the distribution range is 0.12 - 0.17 μm. The powder morphology is spherical, the particle size of the powder is uniform, and the dispersibility is good. Its X-ray diffraction pattern is shown in Figure 7 .

[0050] Example 2

[0051] 1. Dissolve 1.04 g of ruthenium trichloride in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and dissolve 0.46 g of ammonium sulfate in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0052] 2. Mix the ruthenium ion-containing solution and the sulfate ion-containing solution. The molar ratio of sulfate ions to ruthenium ions in the solution is 0.7. Add 6 g of urea to the mixed solution, and then make up the volume of the solution to 1000 ml with deionized water. Stir well to make the solution uniformly mixed, and then continuously stir the solution at room temperature for homogenization treatment for 1 h.

[0053] 3. Heat the homogenized solution to 85 °C with stirring, keep it at this temperature for 240 min, and then let the solution cool naturally. Filter, wash, and dry the precipitate to obtain the precursor precipitate powder. The morphology of the obtained precursor precipitate powder is shown in Figure 8 , the powder is highly dispersed, the powder morphology is spherical, and the particle size range of the powder is 0.1 - 0.25 μm.

[0054] 4. Place the precursor precipitate powder in an alumina crucible and place it in a hydrogen furnace. Keep it at 350 °C in hydrogen for 45 min, and then cool it with the furnace after the insulation is completed to obtain ruthenium powder. The morphology of the obtained ruthenium powder is shown in Figure 9 , the particle size of the ruthenium powder is less than 1 μm, and the distribution range is 0.09 - 0.14 μm. The powder morphology is spherical, the particle size of the powder is uniform, and the dispersibility is good. Its X-ray diffraction pattern is shown in Figure 10 .

[0055] Example 3

[0056] 1. Dissolve 1.75 g of ammonium chlororuthenate in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and dissolve 0.23 g of ammonium bisulfate in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0057] 2. Mix the ruthenium ion-containing solution with the sulfate ion-containing solution. The molar ratio of sulfate ions to ruthenium ions in the solution is 0.4. Add 9 g of urea to the mixed solution, and then make up the volume of the solution to 1000 ml with deionized water. Stir well to make the solution uniformly mixed. Then, keep stirring the solution at room temperature for homogenization for 1 h.

[0058] 3. Heat the homogenized solution to 90 °C with stirring, keep it warm for 240 min, and then let the solution cool naturally. Filter, wash, and dry the precipitate to obtain the precursor precipitate powder. The obtained precursor precipitate powder has a spherical morphology, the powder is highly dispersed, and the particle size range of the powder is 0.05 - 0.15 μm.

[0059] 4. Place the precursor precipitate powder in an alumina crucible, put it in a hydrogen furnace, keep it at 600 °C in hydrogen for 45 min, and then cool it with the furnace after the heat preservation ends to obtain ruthenium powder. The obtained ruthenium powder has a particle size less than 1 μm, the powder has a spherical morphology, the particle size of the powder is uniform and the dispersibility is good.

[0060] Example 4

[0061] 1. Dissolve 1.59 g of ruthenium nitrate in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and dissolve 3.3 g of ammonium sulfate in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0062] 2. Mix the ruthenium ion-containing solution with the sulfate ion-containing solution. The molar ratio of sulfate ions to ruthenium ions in the solution is 5. Add 7.51 g of urea to the mixed solution, and then make up the volume of the solution to 1000 ml with deionized water. Stir well to make the solution uniformly mixed. Then, keep stirring the solution at room temperature for homogenization for 1 h..

[0063] 3. Heat the homogenized solution to 80 °C with stirring, keep it warm for 180 min, and then let the solution cool naturally. Filter, wash, and dry the precipitate to obtain the precursor precipitate powder. The obtained precursor precipitate powder has a spherical morphology, the powder is highly dispersed, and the particle size range of the powder is 0.4 - 0.6 μm.

[0064] 4. Place the precursor precipitate powder in an alumina crucible, put it in a hydrogen furnace, keep it at 400 °C in hydrogen for 30 min, and then cool it with the furnace after the heat preservation ends to obtain ruthenium powder. The obtained ruthenium powder has a particle size less than 1 μm, the powder has a spherical morphology, the particle size of the powder is uniform and the dispersibility is good.

[0065] Example 5

[0066] 1. Dissolve 1.47 g of ruthenium sulfate in 400 ml of deionized water to prepare a solution containing both ruthenium ions and sulfate ions.

[0067] 2. The molar ratio of sulfate ions to ruthenium ions in the solution is 2. 9 g of urea is added to the ruthenium sulfate solution, and then the solution is made up to 1000 ml with deionized water. The solution is stirred thoroughly to mix evenly, and then the solution is continuously stirred at room temperature for homogenization for 1 h.

[0068] 3. The homogenized solution is heated to 95 °C with stirring and kept warm for 240 min, and then the solution is cooled naturally. The precipitate is filtered, washed, and dried to obtain the precursor precipitate powder. The obtained precursor precipitate powder has a spherical morphology, the powder is highly dispersed, and the particle size range of the powder is 0.3 - 0.5 μm.

[0069] 4. The precursor precipitate powder is placed in an alumina crucible and placed in a hydrogen furnace. It is kept warm at 500 °C in hydrogen for 90 min, and after the heat preservation is completed, it is cooled with the furnace to obtain ruthenium powder. The obtained ruthenium powder has a particle size of less than 1 μm, the powder has a spherical morphology, the particle size of the powder is uniform and the dispersibility is good.

[0070] Example 6

[0071] 1. 0.52 g of ruthenium trichloride and 0.79 g of ruthenium nitrate are mixed and dissolved in 400 ml of deionized water to prepare a ruthenium ion-containing solution, and 1.16 g of ammonium sulfate is dissolved in 400 ml of deionized water to prepare a sulfate ion-containing solution.

[0072] 2. The ruthenium ion-containing solution and the sulfate ion-containing solution are mixed. The molar ratio of sulfate ions to ruthenium ions in the solution is 1.75. 6 g of urea is added to the mixed solution, and then the solution is made up to 1000 ml with deionized water. The solution is stirred thoroughly to mix evenly, and then the solution is continuously stirred at room temperature for homogenization for 1 h.

[0073] 3. The homogenized solution is heated to 85 °C with stirring and kept warm for 150 min, and then the solution is cooled naturally. The precipitate is filtered, washed, and dried to obtain the precursor precipitate powder. The obtained precursor precipitate powder has a spherical morphology, the powder is highly dispersed, and the particle size range of the powder is 0.3 - 0.5 μm.

[0074] 4. The precursor precipitate powder is placed in an alumina crucible and placed in a hydrogen furnace. It is kept warm at 550 °C in hydrogen for 30 min, and after the heat preservation is completed, it is cooled with the furnace to obtain ruthenium powder. The obtained ruthenium powder has a particle size of less than 1 μm, the powder has a spherical morphology, the particle size of the powder is uniform and the dispersibility is good.

Claims

1. Preparation method of highly dispersed spherical ruthenium powder with particle size less than 1 μm Characterized in that: The ruthenium powder includes Class I ruthenium powder, Class II ruthenium powder, Class III ruthenium powder, Class IV ruthenium powder and Class V ruthenium powder: When preparing the Class I ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.25 - 0.5, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.05 - 0.15 μm; When preparing the Class II ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.5 - 0.75, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.1 - 0.25 μm; When preparing the Class III ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 0.75 - 1.25, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.2 - 0.4 μm; When preparing the Class IV ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 1.25 - 2, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.3 - 0.5 μm; When preparing the Class V ruthenium powder, the molar ratio of sulfate ions to ruthenium ions in the reaction solution is 2 - 5, and a highly dispersed spherical precursor precipitate powder is obtained through the urea homogeneous precipitation process. The particle size range of the precursor precipitate powder is 0.4 - 0.6 μm; The above-mentioned highly dispersed spherical precursor precipitate powders are respectively calcined at high temperature with hydrogen to obtain highly dispersed spherical ruthenium powder with particle size less than 1 μm.

2. The preparation method according to claim 1, Characterized in that: Prepare a reaction solution containing ruthenium ions and sulfate ions, add urea to the reaction solution, perform homogenization treatment on the solution at room temperature, then raise the temperature under stirring to react to form a precipitate. After cooling, filter, wash and dry the precipitate to obtain a highly dispersed spherical precursor precipitate powder; the particle size range of the highly dispersed spherical precursor precipitate powder is 0.05 - 0.6 μm; the highly dispersed spherical precursor precipitate powder is calcined in a hydrogen atmosphere to obtain highly dispersed spherical ruthenium powder with particle size less than 1 μm.

3. The preparation method according to claim 1 or 2, Characterized in that: The concentration of ruthenium ions in the reaction solution is 0.0001 - 0.1 mol / L, and the molar ratio of sulfate ions to ruthenium ions is 0.25 - 5.

4. The preparation method according to claim 1 or 2, Characterized in that: The molar ratio of urea to ruthenium ions is 1 - 50, the homogenization treatment time is 1 - 2 h, the temperature for the reaction to form a precipitate is 80 - 100 °C, and the reaction time for forming a precipitate is 10 - 300 min.

5. The preparation method according to claim 1 or 2, Characterized in that: In the high-temperature hydrogen calcination process, the calcination temperature is 200 - 800 °C, and the calcination time is 10 - 120 min.

6. The preparation method according to claim 1 or 2, Characterized in that: The sulfate ions are selected from one or more of sulfuric acid, ammonium sulfate, and ammonium bisulfate.

7. The preparation method according to claim 1 or 2, characterized in that: the ruthenium ions are selected from one or more of ruthenium trichloride, ammonium chlororuthenate, ruthenium sulfate, and ruthenium nitrate.

8. The ruthenium powder with a particle size less than 1 μm and high dispersion and spherical shape obtained by the preparation method according to any one of claims 1-7.

9. The ruthenium powder according to claim 8, characterized in that: the ruthenium powder is spherical, with a particle size less than 1 μm and controllable, a narrow particle size distribution range, and the powder is highly dispersed.

10. The application of the ruthenium powder according to claim 9 in the field of semiconductor sputtering targets.

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