Indium cerium oxide target material with controllable and uniform density and preparation method thereof

Abstract

The invention belongs to the technical field of target material preparation, and discloses a preparation method of an indium cerium oxide target material with controllable and uniform density. The preparation method comprises the following steps: (1) adding indium oxide, cerium oxide and ammonium polyacrylate into deionized water, and carrying out ball milling, drying and screening to obtain powder; (2) carrying out two-stage calcination treatment on the powder to obtain calcined powder; (3) mixing the calcined powder with deionized water, a binder and a dispersant, and carrying out secondary ball milling to obtain slurry; (4) adding a defoaming agent into the slurry, and performing spray granulation and compression molding to obtain an RPD target material biscuit; and (5) carrying out cold isostatic pressing and calcining on the RPD target material biscuit to obtain the indium cerium oxide target material. The RPD target material with the controllable density is prepared by controlling powder treatment and sintering technologies, and the density can be controlled between 60% and 85% according to actual needs. In addition, while the density is accurately controlled, the sizes of crystal grains in the RPD target material are also uniformly distributed, so that favorable conditions are provided for subsequent preparation of a high-performance thin film. The RPD target material deposition rate is high, the production efficiency is high, and the requirements of industrial large-scale production can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of target material preparation, and in particular relates to a method for preparing a density-controllable and uniform indium cerium oxide target material. Background Art

[0002] With the rapid development of contemporary society, energy issues have attracted great attention from countries around the world. Developing renewable energy is an important way to solve the energy crisis. As an important renewable energy device, solar cells have become an indispensable part of people's lives, such as solar photovoltaic lighting, solar cars and solar photovoltaic power generation. Transparent conductive oxides (TCOs) are widely used in these devices.

[0003] Indium tin oxide target (ITO) prepared by doping indium oxide with tin oxide is currently the most widely used material in the TCO layer, but this does not mean that ITO has no disadvantages. According to research, among the transparent electrode materials of silicon heterojunction solar cells, cerium-doped indium oxide (ICO) has a higher carrier mobility than ITO film. Due to the lower carrier density, it can effectively reduce the absorption of long-wave free carriers, and the prepared ICO film has better conductivity and transmittance.

[0004] At present, the technology for preparing thin films can be mainly divided into two methods: magnetron sputtering (Physical vapordeposition, PVD) and reactive plasma deposition (Reactive plasma deposition, RPD). For RPD technology, thin films are obtained by hollow cathode discharge of solid targets under low voltage and high current conditions. During the RPD process, the solid target is sublimated into a gas state and dissociated by the electron beam. These target ions then react with the gas present in the deposition chamber to form the desired film. Due to the long distance from the plasma to the substrate, the bombardment damage of the substrate by high-energy ions is reduced. Another advantage of RPD is that it can achieve low-temperature deposition, which can produce films with uniform structure and good performance. In reactive plasma deposition (RPD) technology, the target material usually requires a suitable density to meet the unique process requirements of this technology. Generally speaking, a certain amount of pores is required in the target material (the density of the target material cannot be too high, such as not higher than 85%). This non-dense target material is more suitable for the RPD evaporation process and helps to reduce cracking during the evaporation process; but if the density is too low (such as not less than 60%), it is easy to cause the risk of target material splashing and powder falling, so the density range of the target material should be effectively controlled. The present invention provides a method for preparing a uniform RPD target material with a relative density of 60-85% to meet different needs in production practice. Summary of the invention

[0005] In order to solve the problem of controlling the density and uniformity of indium cerium oxide target, the present invention proposes a method for preparing indium cerium oxide target with controllable and uniform density. The method incorporates cerium into indium oxide and uses improved powder processing and sintering processes to prepare ICO RPD target, achieving uniform and controllable density and grain structure of the target.

[0006] To achieve the above object, the technical solution of the present invention is implemented as follows: A method for preparing a density-controllable and uniform indium cerium oxide target, comprising the following steps: (1) adding indium oxide, cerium oxide and ammonium polyacrylate into deionized water to obtain a mixed slurry; the mixed slurry is ball-milled, dried and then sieved to obtain a powder; (2) calcining the powder obtained in step (1) in two stages to obtain calcined powder; (3) mixing the calcined powder obtained in step (2) with deionized water, a binder and a dispersant, and performing secondary ball milling to obtain a slurry; (4) adding a defoaming agent to the slurry obtained in step (3), and obtaining a molded RPD target blank by spray granulation and compression molding; (5) The RPD target blank is vacuum packaged and cold isostatically pressed, and then calcined to obtain a density-controlled and uniform indium cerium oxide target.

[0007] In the above step (1), based on the mass percentage of indium oxide and cerium oxide, 93-99.5% of indium oxide and 0.5-7% of cerium oxide are taken; the mass of ammonium polyacrylate is 0.5-1% of the total mass of indium oxide and cerium oxide, and the mass of deionized water accounts for 50-70% of the mass of the mixed slurry.

[0008] During the ball milling process of step (1), the mass ratio of the mixed slurry to the grinding balls is 1:3, the rotation speed of the ball mill is 240-300 r / min, and the ball milling time is 9-13 h; the sieve is a 100-200 mesh sieve.

[0009] Furthermore, the grinding balls are zirconium oxide grinding balls.

[0010] The two-stage calcination treatment in the above step (2) refers to first raising the temperature from room temperature to 400-600°C, keeping the temperature for 2-6 hours, and then continuing to raise the temperature to 900-1400°C for calcination time of 2-11 hours.

[0011] In the above step (3), the mass ratio of the dispersant to the binder is (1-2):(1-3), the mass of the dispersant is 0.5-1% of the mass of the calcined powder; the mass of the deionized water is 50-70% of the total mass of the slurry.

[0012] Furthermore, the dispersant is ammonium polyacrylate and the binder is polyvinyl alcohol.

[0013] In the secondary ball milling of step (3) above, the rotation speed of the ball mill is set to 300-350 r / min, and the mass ratio of the grinding balls to the mixed powder (calcined powder, deionized water, binder and dispersant) is 3:1.

[0014] The mass of the defoaming agent in the above step (4) is 0.5-1.5% of the mass of the deionized water in the slurry; the temperature of the spray granulation is 190-210°C, and the centrifugal frequency of the atomizer is 30-45Hz.

[0015] Furthermore, the above-mentioned defoaming agent is n-octanol.

[0016] The pressure of the compression molding in the above step (4) is 40-60MP, and the holding time is 3-8min.

[0017] In the above step (5), the pressure of cold isostatic pressing is 190-250MP, and the holding time is 2-10min; calcination refers to heating from room temperature to 500-750°C at a heating rate of 1-3°C / min, and keeping the temperature for 3-10h; then heating to 1000-1400°C / min at a heating rate of 2-4°C / min, and keeping the temperature for 2-12h.

[0018] The indium cerium oxide target material with controllable and uniform density is prepared by the above-mentioned preparation method.

[0019] The beneficial effects produced by the present invention are: The present invention prepares an RPD target material of ICO with controllable density by controlling powder processing and sintering technology, and the relative density can be controlled between 60 and 85% according to actual needs. In addition, while accurately controlling the density range, the pores and grains inside the RPD target material are also evenly distributed, which provides favorable conditions for the subsequent use of the target material and the preparation of high-performance films. The RPD target material has a relatively fast deposition rate and high production efficiency, which can meet the needs of large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is the microstructure of the indium cerium oxide target prepared in Example 1.

[0022] Figure 2This is the XRD spectrum of the indium cerium oxide target prepared in Example 1.

[0023] Figure 3 This is the organizational morphology of the indium cerium oxide target prepared in Comparative Example 1. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1 The method for preparing a density-controllable and uniform indium cerium oxide target in this embodiment comprises the following steps: Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 97.5% of indium oxide powder, 2.5% of cerium oxide powder, and ammonium polyacrylate as a dispersant, taking 0.5% of the mass of the raw material powder (indium oxide powder and cerium oxide powder); the mass of deionized water accounts for 60% of the mass of the mixed slurry, and mix the above raw materials evenly.

[0026] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 3:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 260r / min and the ball milling time is 10h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0027] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 100-mesh screen. After that, place the powder in a crucible and perform two-stage calcination in a sintering furnace. First, the temperature is raised from room temperature to 450°C and kept for 2 hours. Then the temperature is further raised to 1000°C for calcination for 4 hours. After the calcination is completed, collect the calcined powder for standby use.

[0028] Step 4: Evenly mix the calcined powder, a certain amount of deionized water, a binder and a dispersant, and perform a second ball milling to obtain a slurry. Evenly mix the calcined powder, 60% of the total mass of the slurry with deionized water and 1% of the mass of the calcined powder with a dispersant (ammonium polyacrylate), and perform a second ball milling. After grinding for 12 hours, add a binder (polyvinyl alcohol) of 1% of the mass of the calcined powder to the slurry, continue to ball mill in the ball mill for 1 hour, and then take out the slurry for use. The speed of the ball mill is set to 320r / min, and the mass ratio of grinding balls to slurry is 3:1.

[0029] Step 5: The slurry obtained in step 4 is subjected to spray granulation by a spray granulator. During the spray granulation process, n-octanol needs to be added to eliminate bubbles in the slurry, and the amount of the defoamer is 1% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 210°C, and the centrifugal frequency of the atomizer is set to 45Hz.

[0030] Step 6: Use a balance to weigh a certain amount of granulated powder and place it in a mold, and use a hydraulic press to press it. The pressure is set to 60MP and the holding time is 5 minutes, and then the target blank is obtained.

[0031] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 250MP and the holding time is 5 minutes. After the cold isostatic pressing is completed, a target blank with high density and good uniformity of structure is obtained.

[0032] Step 8: Start pressureless sintering of the target. Place the target blank into the sintering furnace for heating from room temperature to 750°C, with a heating rate of 1°C / min, and keep warm for 3 hours. Then continue to raise the temperature to 1350°C and keep warm at this temperature for 6 hours. The heating rate in this stage is 2.5°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0033] The density of the indium cerium oxide target prepared in this example is 5.8419 g / cm 3 , the relative density is 81.53%. Figure 1 The RPD target material of ICO obtained as shown has a uniform structure, and the pores are evenly distributed inside the target material, so that a target material with uniform structure and fine grains is obtained, and the phase is the structural phase of indium oxide ( Figure 2 ).

[0034] Example 2 The method for preparing a density-controllable and uniform indium cerium oxide target in this embodiment comprises the following steps: Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 95% of indium oxide powder, 5% of cerium oxide powder, and ammonium polyacrylate as a dispersant. Take 1% of the mass of the raw material powder (indium oxide powder and cerium oxide powder); the mass of deionized water accounts for 60% of the mass of the mixed slurry, and mix the above raw materials evenly.

[0035] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 3:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 280r / min and the ball milling time is 10h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0036] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 100-mesh screen. After that, place the powder in a crucible and perform two-stage calcination in a sintering furnace. First, the temperature is raised from room temperature to 500°C and kept for 2 hours. Then the temperature is further raised to 1100°C for calcination for 4 hours. After the calcination is completed, collect the calcined powder for later use.

[0037] Step 4: Evenly mix the calcined powder, a certain amount of deionized water, a binder and a dispersant, and perform a second ball milling to obtain a slurry. Evenly mix the calcined powder, 60% of the total mass of the slurry with deionized water and 1% of the mass of the calcined powder with a dispersant (ammonium polyacrylate), and perform a second ball milling. After grinding for 12 hours, add 1% of the mass of the calcined powder as a binder (polyvinyl alcohol) to the slurry, continue to ball mill in the ball mill for 1 hour, and then take out the slurry for use. The speed of the ball mill is set to 320r / min, and the mass ratio of grinding balls to slurry is 3:1.

[0038] Step 5: The slurry obtained in step 4 is subjected to spray granulation by a spray granulator. During the spray granulation process, n-octanol needs to be added to eliminate bubbles in the slurry, and the amount of the defoamer is 1% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 200°C, and the centrifugal frequency of the atomizer is set to 45Hz.

[0039] Step 6: Use a balance to weigh a certain amount of granulated powder and place it in a mold, and use a hydraulic press to press it. The pressure is set to 50MP, and the holding time is 6 minutes, and then the target blank is obtained.

[0040] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 250MP and the holding time is 5 minutes. After the cold isostatic pressing is completed, a target blank with high density and good uniformity of structure is obtained.

[0041] Step 8: Start pressureless sintering of the target. Place the target blank into the sintering furnace for heating, from room temperature to 700°C, with a heating rate of 1°C / min, and keep it warm for 4 hours. Then continue to raise the temperature to 1220°C and keep it warm for 6 hours at this temperature, with a heating rate of 2°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0042] The density of the indium cerium oxide target prepared in this example is 5.3276 g / cm 3 , the relative density is 74.36%. The grain size inside the target is small and evenly distributed, and the pores are evenly distributed inside the target.

[0043] Example 3 The method for preparing a density-controllable and uniform indium cerium oxide target in this embodiment comprises the following steps: Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 99% of indium oxide powder, 1% of cerium oxide powder, and ammonium polyacrylate as a dispersant. Take 1% of the mass of the raw material powder (indium oxide powder and cerium oxide powder); the mass of deionized water accounts for 60% of the mass of the mixed slurry, and mix the above raw materials evenly.

[0044] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 3:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 300r / min and the ball milling time is 10h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0045] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 100-mesh screen. After that, place the powder in a crucible and perform two-stage calcination in a sintering furnace. First, the temperature is raised from room temperature to 550°C and kept for 2 hours. Then the temperature is further raised to 1200°C for calcination for 4 hours. After calcination is completed, collect the calcined powder for standby use.

[0046] Step 4: Evenly mix the calcined powder, a certain amount of deionized water, a binder and a dispersant, and perform a second ball milling to obtain a slurry. Evenly mix the calcined powder, 60% of the total mass of the slurry with deionized water and 1% of the mass of the calcined powder with a dispersant (ammonium polyacrylate), and perform a second ball milling. After grinding for 12 hours, add 1% of the mass of the calcined powder as a binder (polyvinyl alcohol) to the slurry, continue to ball mill in the ball mill for 1 hour, and then take out the slurry for use. The speed of the ball mill is set to 350r / min, and the mass ratio of grinding balls to slurry is 3:1.

[0047] Step 5: The slurry obtained in step 4 is subjected to spray granulation by a spray granulator. During the spray granulation process, n-octanol needs to be added to eliminate bubbles in the slurry, and the amount of the defoamer is 1% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 200°C, and the centrifugal frequency of the atomizer is set to 45Hz.

[0048] Step 6: Weigh a certain amount of granulated powder using a balance and place it in a mold, and use a hydraulic press to press it. The pressure is set to 40MP, and the holding time is 8 minutes, and then the target blank is obtained.

[0049] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 250MP and the holding time is 5 minutes. After the cold isostatic pressing is completed, a target blank with high density and good uniformity of structure is obtained.

[0050] Step 8: Start pressureless sintering of the target. Place the target blank into the sintering furnace for heating, from room temperature to 600°C, with a heating rate of 1°C / min, and keep warm for 6 hours. Then continue to raise the temperature to 1120°C and keep warm at this temperature for 6 hours. The heating rate in this stage is 2°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0051] The density of the indium cerium oxide target prepared in this example is 4.5881 g / cm 3 , the relative density is 64.03%. The grain size inside the target is small and evenly distributed.

[0052] Example 4 The method for preparing a density-controllable and uniform indium cerium oxide target in this embodiment comprises the following steps: Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 93% of indium oxide powder, 7% of cerium oxide powder, and ammonium polyacrylate as a dispersant, taking 0.75% of the mass of the raw material powder (indium oxide powder and cerium oxide powder); the mass of deionized water accounts for 50% of the mass of the mixed slurry, and mix the above raw materials evenly.

[0053] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 3:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 240r / min and the ball milling time is 13h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0054] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 200-mesh screen. After that, place the powder in a crucible and perform two-stage calcination in a sintering furnace. First, the temperature is raised from room temperature to 400°C and kept for 6 hours. Then the temperature is further raised to 1400°C for calcination for 2 hours. After calcination is completed, collect the calcined powder for standby use.

[0055] Step 4: Evenly mix the calcined powder, a certain amount of deionized water, a binder and a dispersant, and perform a second ball milling to obtain a slurry. Evenly mix the calcined powder, 50% of the total mass of the slurry with deionized water and 0.5% of the mass of the calcined powder with a dispersant (ammonium polyacrylate), and perform a second ball milling. After grinding for 12 hours, add 0.75% of the mass of the calcined powder as a binder (polyvinyl alcohol) to the slurry, continue to ball mill in the ball mill for 1 hour, and then take out the slurry for use. The speed of the ball mill is set to 350r / min, and the mass ratio of grinding balls to slurry is 3:1.

[0056] Step 5: The slurry obtained in step 4 is sprayed and granulated by a spray granulator. During the spray granulation process, n-octanol needs to be added to eliminate bubbles in the slurry. The amount of the defoamer is 1.5% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 190°C, and the centrifugal frequency of the atomizer is set to 30Hz.

[0057] Step 6: Use a balance to weigh a certain amount of granulated powder and place it in a mold, and use a hydraulic press to press it. The pressure is set to 60MP, and the holding time is 3 minutes, and then the target blank is obtained.

[0058] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 190MP and the holding time is 10 minutes. After the cold isostatic pressing is completed, a target blank with high density and good uniformity of structure is obtained.

[0059] Step 8: Start pressureless sintering of the target. Place the target blank into the sintering furnace for heating, from room temperature to 500°C, with a heating rate of 3°C / min, and keep warm for 10 hours. Then continue to raise the temperature to 1400°C and keep warm at this temperature for 2 hours. The heating rate in this stage is 4°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0060] The density of the indium cerium oxide target prepared in this example is 5.9626 g / cm 3 , the relative density is 83.22%. The internal structure of the target is uniform, and the grain size is uniform and small.

[0061] Example 5 The method for preparing a density-controllable and uniform indium cerium oxide target in this embodiment comprises the following steps: Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 99.5% of indium oxide powder, 0.5% of cerium oxide powder, and ammonium polyacrylate as a dispersant. Take 1% of the mass of the raw material powder (indium oxide powder and cerium oxide powder); the mass of deionized water accounts for 70% of the mass of the mixed slurry, and mix the above raw materials evenly.

[0062] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 3:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 260r / min and the ball milling time is 9h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0063] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 200-mesh screen. After that, place the powder in a crucible and perform two-stage calcination in a sintering furnace. First, the temperature is raised from room temperature to 600°C and kept for 5 hours. Then the temperature is further raised to 900°C for calcination, and the calcination time is 11 hours. After the calcination is completed, collect the calcined powder for standby use.

[0064] Step 4: Evenly mix the calcined powder, a certain amount of deionized water, a binder and a dispersant, and perform a second ball milling to obtain a slurry. Evenly mix the calcined powder, 70% of the total mass of the slurry with deionized water and 0.5% of the mass of the calcined powder (ammonium polyacrylate), and perform a second ball milling. After grinding for 12 hours, add 1.5% of the mass of the calcined powder as a binder (polyvinyl alcohol) to the slurry, continue to ball mill in the ball mill for 1 hour, and then take out the slurry for use. The speed of the ball mill is set to 350r / min, and the mass ratio of grinding balls to slurry is 3:1.

[0065] Step 5: The slurry obtained in step 4 is subjected to spray granulation by a spray granulator. During the spray granulation process, n-octanol needs to be added to eliminate bubbles in the slurry, and the amount of the defoamer is 0.5% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 200°C, and the centrifugal frequency of the atomizer is set to 30Hz.

[0066] Step 6: Use a balance to weigh a certain amount of granulated powder and place it in a mold, and use a hydraulic press to press it. The pressure is set to 60MP, and the holding time is 3 minutes, and then the target blank is obtained.

[0067] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 230MP and the holding time is 2 minutes. After the cold isostatic pressing is completed, a target blank with high density and good uniformity of structure is obtained.

[0068] Step 8: Start pressureless sintering of the target. Place the target blank into the sintering furnace for heating, from room temperature to 700°C, with a heating rate of 2°C / min, and keep warm for 6 hours. Then continue to increase the temperature to 1000°C and keep it at this temperature for 12 hours. The heating rate in this stage is 3°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0069] The density of the indium cerium oxide target prepared in this example is 4.5590 g / cm 3 , the relative density is 63.63%. The grain size inside the target is small and uniform, and the pores are evenly distributed.

[0070] Comparative Example 1 Step 1: Mix the slurry and mix the raw materials according to the mass percentage. Take 99% of indium oxide powder; 1% of cerium oxide powder, and 1% of ammonium polyacrylate as a dispersant; the mass of deionized water accounts for 60% of the total slurry mass, and mix the above raw materials evenly.

[0071] Step 2: Pour the slurry mixed evenly in step 1 into a ball mill, and add zirconium oxide grinding balls into it. The mass ratio of zirconium oxide grinding balls to slurry is 2:1. Place the ball mill on a planetary ball mill for ball milling. The speed of the ball mill is set to 200r / min and the ball milling time is 6h. After the ball milling is completed, transfer the slurry in the ball mill to a 90°C oven for drying.

[0072] Step 3: Grind and crush the dried slurry in step 2 in an agate mortar, and then pass it through a 100-mesh screen. After that, place the powder in a crucible and calcine it in a sintering furnace. The temperature is raised from room temperature to 1200°C for 4 hours. After the calcination is completed, collect the calcined powder for later use.

[0073] Step 4: Evenly mix the calcined powder, 60% deionized water of the slurry mass and 1% dispersant of the powder mass. Use ammonium polyacrylate as the dispersant. Perform the second ball milling. After grinding for 6 hours, add a binder to the slurry. Use polyvinyl alcohol as the binder. The mass of the added binder is 1% of the mass of the calcined powder. After continuing to ball mill in the ball mill for 1 hour, take out the slurry for standby use. The speed of the ball mill is set to 280r / min, and the mass ratio of grinding balls to slurry is 2:1.

[0074] Step 5: The slurry obtained in step 4 is sprayed and granulated by a spray granulator. During the spray granulation process, a defoamer needs to be added to eliminate bubbles in the slurry. The amount of the defoamer is 1% of the mass of the deionized water used in step 4. The temperature of the spray granulator is set to 200°C, and the centrifugal frequency of the atomizer is set to 45Hz.

[0075] Step 6: Use a balance to weigh a certain amount of granulated powder and place it in a mold, and use a hydraulic press to press it. The pressure is set to 40MP, and the holding time is 6 minutes, and then the target blank is obtained.

[0076] Step 7: Put the target blank into a vacuum packaging bag and place it in a vacuum packaging machine for vacuum treatment. Put the packaged target blank into a cold isostatic press for isostatic pressing. The pressure is set to 200MP and the holding time is 4 minutes. After the cold isostatic pressing is completed, the target blank is obtained.

[0077] Step 8: Start pressureless sintering of the target. Put the target blank into the sintering furnace for one-stage heating, from room temperature to 1050°C and keep it at this temperature for 3 hours. The heating rate in this stage is 2°C / min. When the sintering process is completed and the temperature drops to room temperature, the indium cerium oxide target is obtained.

[0078] The density of the indium cerium oxide target prepared in this comparative example is 4.2036 / cm 3 , the relative density is 58.67%. The grain size distribution inside the RPD target material of ICO obtained is relatively uneven, with coarse grains and large pores, such as Figure 3 shown.

[0079] Compared with the embodiment, the relative density of the RPD target obtained in the comparative example 1 is obviously not controlled within the range of 60-80%, and the grain size inside the target is not as uniformly distributed as in the embodiment, which shows that the powder processing process and the two-stage sintering process of the target blank and the powder in the embodiment can control the density while preventing the uneven distribution of the grain size inside the target.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a density-controllable and uniform indium cerium oxide target, characterized in that: Here are the steps: (1) adding indium oxide, cerium oxide and ammonium polyacrylate into deionized water to obtain a mixed slurry; the mixed slurry is ball-milled, dried and then sieved to obtain a powder; (2) calcining the powder obtained in step (1) in two stages to obtain calcined powder; (3) mixing the calcined powder obtained in step (2) with deionized water, a binder and a dispersant, and performing secondary ball milling to obtain a slurry; (4) adding a defoaming agent to the slurry obtained in step (3), and obtaining a molded RPD target blank by spray granulation and compression molding; (5) The RPD target blank is vacuum packaged and cold isostatically pressed, and then calcined to obtain a density-controlled and uniform indium cerium oxide target.

2. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 1, characterized in that: In the step (1), the mass ratio of indium oxide to cerium oxide is (93-99.5):(0.5-7), the mass of ammonium polyacrylate is 0.5-1% of the total mass of indium oxide and cerium oxide, and the mass of deionized water accounts for 50-70% of the mass of the mixed slurry.

3. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 2, characterized in that: In the ball milling process of step (1), the mass ratio of the mixed slurry to the grinding balls is 1:3, the rotation speed of the ball mill is 240-300 r / min, and the ball milling time is 9-13 h; the sieve is a 100-200 mesh sieve.

4. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 3, characterized in that: The two-stage calcination treatment in step (2) refers to first raising the temperature from room temperature to 400-600°C, keeping the temperature for 2-6 hours, and then continuing to raise the temperature to 900-1400°C for calcination time of 2-11 hours.

5. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 4, characterized in that: In the step (3), the mass ratio of the dispersant to the binder is (1-2):(1-3), the mass of the dispersant is 0.5-1% of the mass of the calcined powder; the mass of the deionized water is 50-70% of the total mass of the slurry.

6. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 5, characterized in that: The mass of the defoaming agent in step (4) is 0.5-1.5% of the mass of the deionized water in the slurry; the temperature of the spray granulation is 190-210° C., and the centrifugal frequency is 30-45 Hz.

7. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 6, characterized in that: The compression molding pressure in step (4) is 40-60 MPa, and the holding time is 3-8 min.

8. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 7, characterized in that: The cold isostatic pressing pressure in step (5) is 190-250 MPa, and the holding time is 2-10 min.

9. The method for preparing a density-controllable and uniform indium cerium oxide target according to claim 7, characterized in that: The calcination in step (5) refers to heating from room temperature to 500-750°C at a heating rate of 1-3°C / min, and keeping the temperature for 3-10h; then heating to 1000-1400°C / min at a heating rate of 2-4°C / min, and keeping the temperature for 2-12h.

10. An indium cerium oxide target with controllable and uniform density prepared by the preparation method according to any one of claims 1 to 9.

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