A method for preparing a high-density target of tin-zinc-zirconium doped with oxygen

Abstract

The present application relates to the technical field of target material, in particular to a preparation method of high-density tin-zinc-zirconium oxide target material. The preparation method comprises the following steps: preparing tin oxide powder, zirconium oxide powder and zinc oxide powder into a mixed slurry, and then performing sand milling, granulation, molding, sintering to obtain the high-density tin-zinc-zirconium oxide target material, wherein the mass ratio of the tin oxide powder, the zirconium oxide powder and the zinc oxide powder is 100:0.1-0.5:9-11. The high-density tin-zinc-zirconium oxide target material prepared by the preparation method has high relative density and low resistivity, and the sputtered film thereof has high transmittance in the visible light range, can replace the traditional indium tin oxide target material, and can be widely applied in the fields of semiconductor integrated circuits, LEDs, displays, touch screens, solar photovoltaics and chemical industry.

Description

Technical Field

[0001] This invention relates to the field of target technology, and in particular to a method for preparing a high-density zirconium oxide doped zinc oxide target. Background Technology

[0002] With the rapid development of global manufacturing, vacuum coating technology has been widely applied in semiconductor integrated circuits, LEDs, displays, touch screens, solar photovoltaics, chemicals, and pharmaceuticals. Indium tin oxide (ITO) has become the most widely used transparent conductive oxide (TCO) material in the industry due to its excellent conductivity and visible light transmittance. However, the low abundance of indium in nature cannot meet market demand, resulting in high ITO prices. Furthermore, indium is toxic, easily pollutes the environment, and poses a threat to human health. Therefore, it is necessary to find a transparent conductive oxide film that is abundant in resources, inexpensive, non-toxic, and stable to replace ITO films.

[0003] In recent years, tin oxide-based materials have been a research hotspot. Patent document CN116655372A discloses a method for preparing tin oxide-based targets. Although the target material has a high relative density, its resistivity is relatively high. Patent document CN113563063A discloses a high-density, fine-grained zinc oxide-doped tin oxide-based ceramic target and its preparation method. By doping an appropriate amount of zinc oxide into the tin oxide substrate, it not only helps to improve the density of the tin oxide-based ceramic target but also makes a positive contribution to improving its conductivity. However, the amount of zinc oxide added in this patent is too high, which leads to a decrease in the transmittance of the film in the visible light range after sputtering. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing a high-density tin-zinc oxide doped zirconium target, so as to provide a tin-zinc oxide target with high relative density and low resistivity, and the thin film material obtained after sputtering has high transmittance in the visible light range.

[0005] To achieve the above objectives, the present invention provides a method for preparing a high-density target material doped with zinc tin oxide, comprising the following steps: preparing a mixed slurry from tin oxide powder, zirconium oxide powder and zinc oxide powder, and then subjecting it to sand milling, granulation, molding and sintering to obtain a high-density target material doped with zinc tin oxide.

[0006] Preferably, the mass ratio of the tin oxide powder, zirconium oxide powder and zinc oxide powder is 100:0.1-0.5:9-11.

[0007] Preferably, the purity of the tin oxide powder, zirconium oxide powder, and zinc oxide powder is ≥99.99%, and the particle size D50 is 100-500 nm.

[0008] Preferably, the specific preparation steps of the mixed slurry are as follows: mixing tin oxide powder, zirconium oxide powder, zinc oxide powder and deionized water, then adding dispersant, binder and defoamer, and stirring evenly to obtain the mixed slurry.

[0009] Preferably, the mass ratio of the tin oxide powder, deionized water, dispersant, binder and defoamer is 100:100-120:0.2-1.2:2-10:0.1-0.2.

[0010] Preferably, the dispersant is BLJ-3359, the binder is BD25 or BD20, and the defoamer is MOK-6026.

[0011] Preferably, the specific steps of the sand milling are as follows: the mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 4-7 passes, for 3-5 hours, to obtain the sand milled slurry.

[0012] Preferably, the specific steps of the granulation are as follows: the sand-milled slurry is spray-granulated in a high-temperature spray granulator with an inlet air temperature of 225±5℃, an outlet air temperature of 110±5℃, and a rotation speed of 7000r / min to obtain a mixed powder.

[0013] Preferably, the specific steps of the molding are as follows: the granulated mixed powder is placed into a 100×200×10cm flat target mold, and firstly, it is pressure molded once using a 10,000-ton hydraulic press at a molding pressure of 100-120MPa for 10 minutes. Then, it is placed into a film bag, vacuumed, and then placed into a cold isostatic press for secondary pressure molding at a molding pressure of 180-210MPa for 40-60 minutes to obtain a pre-sintered target material.

[0014] Preferably, the specific steps of the sintering are as follows: the pre-sintered target material is placed in a sintering furnace for sintering at a sintering pressure of 10-20 MPa, the temperature is increased from room temperature to 250°C at a rate of 0.5-1.5°C / min, then from 250°C to 400°C at a rate of 1.5-2.0°C / min, then from 400°C to 650°C at a rate of 4-6°C / min, and held for 1-2 hours, then from 650°C to 900°C at a rate of 4-6°C / min, then from 900°C to 1500°C at a rate of 4-6°C / min, and held for 10-20 hours; oxygen is introduced from room temperature to 900°C, air is introduced from 900°C to 1500°C, oxygen is introduced during the holding stage after 1500°C, and finally, the material is cooled to obtain a high-density tin-zinc oxide doped zirconium target material.

[0015] Furthermore, the present invention also provides a high-density target material for tin-zinc oxide doped zirconium, obtained according to the above-described preparation method for the high-density target material for tin-zinc oxide doped zirconium.

[0016] The beneficial effects of this invention are:

[0017] (1) Compared with existing tin-zinc oxide targets, the tin-zinc oxide doped zirconium high-density target prepared by the present invention has a lower zinc doping amount, which can effectively solve the problem of reduced transmittance of the film in the visible light range after sputtering of traditional tin-zinc oxide targets.

[0018] (2) The present invention adds a small amount of zirconium to the tin oxide zinc target material with low zinc content, which makes up for the problem of high resistivity of the tin oxide zinc target material caused by the reduction of zinc content, and the addition of zirconium can further improve the relative density of the tin oxide zinc target material.

[0019] (3) By adjusting the atmosphere during the sintering process and using an alternating oxygen and air atmosphere for sintering, the present invention further improves the relative density and conductivity of the zinc tin oxide doped zirconium high-density target. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0021] The tin oxide powder used in the embodiments and comparative examples of the present invention has a purity of 99.995% and a particle size D50 of 210 nm, the zirconium oxide powder has a purity of 99.998% and a particle size D50 of 300 nm, and the zinc oxide powder has a purity of 99.993% and a particle size D50 of 250 nm.

[0022] Example 1: A method for preparing a high-density zirconium oxide doped zinc oxide target:

[0023] (1) Preparation of mixed slurry: Mix 100g tin oxide powder, 0.1g zirconium oxide powder, 9g zinc oxide powder and 100g deionized water, then add 0.2g dispersant BLJ-3359, 2g binder BD25 / BD20 and 0.15g defoamer MOK-6026, stir evenly to obtain mixed slurry;

[0024] (2) Sand milling: The mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 6 passes, for 4 hours to obtain the sand milled slurry;

[0025] (3) Granulation: The sand-milled slurry is sprayed and granulated in a high-temperature spray granulator with an inlet air temperature of 220℃, an outlet air temperature of 115℃, and a rotation speed of 7000r / min to obtain mixed powder.

[0026] (4) Molding: The granulated mixed powder is placed into a 100×200×10cm flat target mold. First, it is pressure molded once using a 10,000-ton hydraulic press with a molding pressure of 100MPa and a molding time of 10min. Then, it is placed into a film bag, vacuumed, and then placed into a cold isostatic press for secondary pressure molding with a molding pressure of 190MPa and a molding time of 40min to obtain the pre-sintered target material.

[0027] (5) Sintering: The pre-sintered target material is placed in a sintering furnace for sintering. The sintering pressure is 15 MPa. The temperature is increased from room temperature to 250℃ at a rate of 0.5℃ / min, then from 250℃ to 400℃ at a rate of 1.5℃ / min, then from 400℃ to 650℃ at a rate of 4℃ / min, and held for 1 hour. Then the temperature is increased from 650℃ to 900℃ at a rate of 4℃ / min, then from 900℃ to 1500℃ at a rate of 4℃ / min, and held for 10 hours. Oxygen is introduced from room temperature to 900℃, air is introduced from 900℃ to 1500℃, and oxygen is introduced during the holding stage after 1500℃. Finally, the temperature is lowered to obtain a high-density target material doped with zinc tin oxide and zirconium.

[0028] Example 2: A method for preparing a high-density zirconium oxide doped zinc oxide target:

[0029] (1) Preparation of mixed slurry: Mix 100g tin oxide powder, 0.3g zirconium oxide powder, 10g zinc oxide powder and 110g deionized water, then add 1g dispersant BLJ-3359, 4g binder BD25 and 0.15g defoamer MOK-6026, stir evenly to obtain mixed slurry;

[0030] (2) Sand milling: The mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 7 passes, for 3 hours to obtain the sand milled slurry;

[0031] (3) Granulation: The sand-milled slurry is sprayed and granulated in a high-temperature spray granulator with an inlet air temperature of 225℃, an outlet air temperature of 110℃, and a rotation speed of 7000r / min to obtain mixed powder.

[0032] (4) Molding: The granulated mixed powder is placed into a 100×200×10cm flat target mold. First, it is pressure molded once using a 10,000-ton hydraulic press with a molding pressure of 100MPa and a molding time of 10min. Then, it is placed into a film bag, vacuumed, and then placed into a cold isostatic press for secondary pressure molding with a molding pressure of 200MPa and a molding time of 50min to obtain the pre-sintered target material.

[0033] (5) Sintering: The pre-sintered target material is placed in a sintering furnace for sintering. The sintering pressure is 20 MPa. The temperature is increased from room temperature to 250℃ at a rate of 1℃ / min, then from 250℃ to 400℃ at a rate of 1.5℃ / min, then from 400℃ to 650℃ at a rate of 5℃ / min, and held for 2 hours. Then the temperature is increased from 650℃ to 900℃ at a rate of 5℃ / min, then from 900℃ to 1500℃ at a rate of 5℃ / min, and held for 15 hours. Oxygen is introduced from room temperature to 900℃, air is introduced from 900℃ to 1500℃, and oxygen is introduced during the holding period after 1500℃. Finally, the temperature is lowered to obtain a high-density target material doped with zinc tin oxide and zirconium oxide.

[0034] Example 3: A method for preparing a high-density zirconium oxide doped tin-zinc oxide target:

[0035] (1) Preparation of mixed slurry: Mix 100g tin oxide powder, 0.5g zirconium oxide powder, 9g zinc oxide powder and 100g deionized water, then add 0.5g dispersant BLJ-3359, 6g binder BD20 and 0.15g defoamer MOK-6026, stir evenly to obtain mixed slurry;

[0036] (2) Sand milling: The mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 5 passes, for 3 hours to obtain the sand milled slurry;

[0037] (3) Granulation: The sand-milled slurry is sprayed and granulated in a high-temperature spray granulator with an inlet air temperature of 230°C, an outlet air temperature of 115°C, and a rotation speed of 7000 r / min to obtain mixed powder.

[0038] (4) Molding: The granulated mixed powder is placed into a 100×200×10cm flat target mold. First, it is pressure molded once using a 10,000-ton hydraulic press with a molding pressure of 100MPa and a molding time of 10min. Then, it is placed into a film bag, vacuumed, and then placed into a cold isostatic press for secondary pressure molding with a molding pressure of 200MPa and a molding time of 60min to obtain the pre-sintered target material.

[0039] (5) Sintering: The pre-sintered target material is placed in a sintering furnace for sintering. The sintering pressure is 10 MPa. The temperature is increased from room temperature to 250°C at a rate of 1°C / min, then from 250°C to 400°C at a rate of 1.5°C / min, then from 400°C to 650°C at a rate of 6°C / min, and held for 2 hours. Then the temperature is increased from 650°C to 900°C at a rate of 6°C / min, then from 900°C to 1500°C at a rate of 6°C / min, and held for 20 hours. Oxygen is introduced from room temperature to 900°C, air is introduced from 900°C to 1500°C, and oxygen is introduced during the holding period after 1500°C. Finally, the temperature is lowered to obtain a high-density target material doped with zinc tin oxide and zirconium oxide.

[0040] Example 4: A method for preparing a high-density zirconium oxide doped zinc oxide target:

[0041] (1) Preparation of mixed slurry: Mix 100g tin oxide powder, 0.5g zirconium oxide powder, 11g zinc oxide powder and 120g deionized water, then add 1.2g dispersant BLJ-3359, 8g binder BD25 and 0.18g defoamer MOK-6026, stir evenly to obtain mixed slurry;

[0042] (2) Sand milling: The mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 7 passes, for 3 hours, to obtain a sand milled slurry with particle sizes D10≤0.1μm, D50≤0.2μm, and D90≤0.9μm;

[0043] (3) Granulation: The sand-milled slurry is sprayed and granulated in a high-temperature spray granulator with an inlet air temperature of 225°C, an outlet air temperature of 115°C, and a rotation speed of 7000 r / min to obtain mixed powder.

[0044] (4) Molding: The granulated mixed powder is placed into a 100×200×10cm flat target mold. First, it is pressure molded once using a 10,000-ton hydraulic press with a molding pressure of 110MPa and a molding time of 10min. Then, it is placed into a film bag, vacuumed, and then placed into a cold isostatic press for secondary pressure molding with a molding pressure of 210MPa and a molding time of 40min to obtain the pre-sintered target material.

[0045] (5) Sintering: The pre-sintered target material is placed in a sintering furnace for sintering. The sintering pressure is 20 MPa. The temperature is increased from room temperature to 250℃ at a rate of 1.5℃ / min, then from 250℃ to 400℃ at a rate of 2.0℃ / min, then from 400℃ to 650℃ at a rate of 6℃ / min, and held for 1 hour. Then the temperature is increased from 650℃ to 900℃ at a rate of 6℃ / min, then from 900℃ to 1500℃ at a rate of 6℃ / min, and held for 15 hours. Oxygen is introduced from room temperature to 900℃, air is introduced from 900℃ to 1500℃, and oxygen is introduced during the holding period after 1500℃. Finally, the temperature is lowered to obtain a high-density target material doped with zinc tin oxide and zirconium oxide.

[0046] Comparative Example 1: A method for preparing a tin-zinc oxide target:

[0047] The difference between Comparative Example 1 and Example 2 is that no zirconium oxide was added in Comparative Example 1.

[0048] Comparative Example 2: A method for preparing a tin-zinc oxide target:

[0049] The difference between Comparative Example 2 and Example 2 is that no zirconium oxide was added in Comparative Example 2, and the amount of zinc oxide added was 30g.

[0050] Comparative Example 3: A method for preparing a tin oxide target:

[0051] The difference between Comparative Example 3 and Example 2 is that no zirconium oxide and zinc oxide were added in Comparative Example 3.

[0052] Comparative Example 4: A method for preparing a tin oxide target:

[0053] The difference between Comparative Example 4 and Example 2 is that Comparative Example 4 does not contain zinc oxide.

[0054] Comparative Example 5: A method for preparing a tin oxide target:

[0055] The difference between Comparative Example 5 and Example 2 is that the atmosphere in Comparative Example 5 during the sintering process is always oxygen.

[0056] Performance testing:

[0057] Relative density: The actual density ρ is measured using Archimedes' displacement method. 实际 =m / v,ρ 相对 =ρ 实际 / ρ 理论 Resistivity: The resistivity of the target material was measured using an ST-2258C multi-functional digital four-probe tester.

[0058] Transmittance: The transmittance of the tin oxide film after magnetron sputtering was measured using a HU-2600A UV-Vis spectrophotometer.

[0059] Table 1 Performance test results of the target material prepared in this invention

[0060]

[0061] Data Analysis: As can be seen from Examples 1-4, the tin-zinc oxide-doped zirconium high-density target prepared by the method of the present invention has a high relative density, reaching over 99.5%, and low resistivity. The sputtered film has high transmittance in the visible light range. As can be seen from Examples 2 and Comparative Examples 1-4, reducing the doping of zinc oxide can improve the transmittance of the sputtered film, but the resistivity of the target is relatively high. However, the doping of zirconium oxide can increase the relative density of the target, reduce the resistivity, and improve the transmittance of the sputtered film. Most importantly, when zirconium oxide is directly doped into the tin oxide target, the improvement in the conductivity of the tin oxide target is minimal. This indicates that zirconium oxide improves the conductivity of the target through synergy with zinc in the tin oxide target. As can be seen from Examples 2 and Comparative Example 5, the oxygen-air alternating calcination method of the present invention can effectively reduce the resistivity of the tin oxide separator.

[0062] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0063] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a high-density zirconium oxide doped zinc oxide target, characterized in that, Includes the following steps: Tin oxide powder, zirconium oxide powder and zinc oxide powder are prepared into a mixed slurry, which is then milled, granulated, shaped and sintered to obtain a high-density zirconium oxide doped zinc oxide target material. The mass ratio of the tin oxide powder, zirconium oxide powder, and zinc oxide powder is 100:0.1-0.5:9-11; The specific steps of the sintering are as follows: the pre-sintered target material is placed in a sintering furnace for sintering at a pressure of 10-20 MPa. The temperature is increased from room temperature to 250°C at a rate of 0.5-1.5°C / min, then from 250°C to 400°C at a rate of 1.5-2.0°C / min, then from 400°C to 650°C at a rate of 4-6°C / min, and held for 1-2 hours. The temperature is then increased from 650°C to 900°C at a rate of 4-6°C / min, then from 900°C to 1500°C at a rate of 4-6°C / min, and held for 10-20 hours. Oxygen is introduced from room temperature to 900°C, air is introduced from 900°C to 1500°C, and oxygen is introduced during the holding period after 1500°C. Finally, the temperature is lowered to obtain a high-density tin-zinc oxide doped zirconium target material.

2. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 1, characterized in that, The purity of the tin oxide powder, zirconium oxide powder, and zinc oxide powder is ≥99.99%, and the particle size D50 is 100-500nm.

3. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 1, characterized in that, The specific preparation steps of the mixed slurry are as follows: tin oxide powder, zirconium oxide powder, zinc oxide powder and deionized water are mixed, then dispersant, binder and defoamer are added, and after stirring evenly, the mixed slurry is obtained.

4. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 3, characterized in that, The mass ratio of the tin oxide powder, deionized water, dispersant, binder and defoamer is 100:100-120:0.2-1.2:2-10:0.1-0.

2.

5. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 3, characterized in that, The dispersant is BLJ-3359, the binder is BD25 or BD20, and the defoamer is MOK-6026.

6. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 1, characterized in that, The specific steps of the sand milling are as follows: the mixed slurry is sand milled in a sand mill at a speed of 3000 r / min, for 4-7 passes, for 3-5 hours, to obtain the sand milled slurry.

7. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 1, characterized in that, The specific steps of the granulation are as follows: the sand-milled slurry is spray-granulated in a high-temperature spray granulator with an inlet air temperature of 225±5℃, an outlet air temperature of 110±5℃, and a rotation speed of 7000r / min to obtain mixed powder.

8. The method for preparing the tin-zinc oxide-doped zirconium high-density target according to claim 1, characterized in that, The specific molding steps are as follows: the granulated mixed powder is placed into a 100×200×10cm flat target mold, and firstly, a 10,000-ton hydraulic press is used for pressure molding at a pressure of 100-120MPa for 10 minutes. Then, it is placed in a film bag, vacuumed, and then placed in a cold isostatic press for secondary pressure molding at a pressure of 180-210MPa for 40-60 minutes to obtain a pre-sintered target material.

9. A high-density target material doped with zinc tin oxide and zirconium, characterized in that, The high-density target material doped with zinc tin oxide according to any one of claims 1-8 is obtained.

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