Zinc aluminum oxide target and method of making the same

Abstract

The application belongs to the technical field of semiconductors and discloses a preparation method of a zinc aluminum oxide target material, which comprises the following steps: step 1: mixing aluminum oxide powder, a first dispersing agent and water to prepare slurry and grinding to obtain a first slurry; step 2: mixing the first slurry, zinc oxide powder and a second dispersing agent to prepare slurry and grinding to obtain a second slurry; step 3: adopting the second slurry to spray granulation to obtain powder with a loose bulk density of 0.8-1 g / cm 3 ; step 4: adopting the powder obtained in step 3 to perform die pressing and cold isostatic pressing to obtain a zinc aluminum oxide target blank; and step 5: sintering the zinc aluminum oxide target blank to obtain a zinc aluminum oxide target material. By controlling the particle size of spray granulation, the application can manufacture powder with a certain loose density, and can prepare a target material with high relative density and low resistivity without using a binder. Meanwhile, the application also provides the zinc aluminum oxide target material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a zinc aluminum oxide target material and a preparation method thereof. BACKGROUND

[0002] The target material is a basic consumable material in the process of magnetron sputtering, and the quality of the target material plays a crucial role in determining the performance of the thin film. The target material is widely used in various fields, mainly including optical target material, display thin film target material, semiconductor field target material, recording medium target material, superconducting target material, etc. Among them, the semiconductor field target material, display target material and recording medium target material are the three most widely used target materials. In order to improve the thin film preparation rate and ensure the growth quality of the thin film, the sputtering target material needs to meet certain index requirements. In recent years, liquid crystal display, active organic light-emitting diode display and flexible display technologies have developed rapidly, and the importance of thin film transistors (TFT) as core components is self-evident. Among them, the TFT based on oxide semiconductor has attracted widespread attention due to its high mobility, good electrical uniformity, high visible light transmittance, low preparation temperature, and low cost.

[0003] In the process of target material preparation, the traditional process of the applicant is to first add a dispersing agent for grinding and dispersion, and then add a binder to press the target material into shape. If the binder is added, a degreasing treatment needs to be performed before sintering.

[0004] In order to reduce the preparation cost, a process without adding a binder is sought.

[0005] After searching, the following prior art is obtained:

[0006] Prior art: CN114436640A discloses a preparation method of a zinc aluminum oxide alloy target material, comprising the following steps: A) mixing zinc oxide and aluminum oxide in a vacuum rolling mixer to obtain a mixture; B) vacuumizing and cold isostatic pressing the mixture to obtain a rough blank, and performing secondary pressing on the rough blank to obtain an alloy target material green body; C) vacuum hot pressing and sintering the alloy target material green body to obtain a zinc aluminum oxide alloy target material crude product; D) annealing the zinc aluminum oxide alloy target material crude product, and plasma spraying the mixture of step A) onto the surface of the annealed zinc aluminum oxide alloy target material crude product to obtain a zinc aluminum oxide alloy target material.

[0007] In this scheme, the powder is directly mixed, which is not suitable for dispersing agents or adhesives. According to the usual production experience, the target material obtained in this way has poor uniformity and high resistivity.

[0008] Therefore, the technical problem solved by the present application is: how to simplify the production process of zinc aluminum oxide target material to obtain a target material with high relative density and low resistivity. SUMMARY

[0009] One of the purposes of the present application is to provide a preparation method of zinc aluminum oxide target, by controlling the particle size of spray granulation, a powder with certain bulk density is manufactured, and a target with high relative density and low resistivity can be prepared without using a binder.

[0010] Meanwhile, the present application also provides the zinc aluminum oxide target.

[0011] Unless otherwise specified in the present application, M is mol / L, and % is mass percentage.

[0012] To achieve the above-mentioned purposes, the present application provides a preparation method of zinc aluminum oxide target, comprising the following steps:

[0013] Step 1: mixing alumina powder, first dispersant and water to prepare slurry and grinding to obtain first slurry;

[0014] Step 2: mixing the first slurry, zinc oxide powder and second dispersant to prepare slurry and grinding to obtain second slurry;

[0015] Step 3: spray granulation of the second slurry to obtain a powder with bulk density of 0.8-1 g / cm 3 ;

[0016] Step 4: die pressing and cold isostatic pressing of the powder obtained in step 3 to obtain a zinc aluminum oxide target blank;

[0017] Step 5: sintering of the zinc aluminum oxide target blank to obtain a zinc aluminum oxide target.

[0018] In the above-mentioned preparation method of zinc aluminum oxide target, the solid content of the first slurry is 60-70wt%, the particle size of the powder in the first slurry is D50<1μm and D90<2.1μm

[0019] , and / or the grinding process of step 1 is: grinding time 10-22h, and grinding speed 1200-1800r / min.

[0020] In the above-mentioned preparation method of zinc aluminum oxide target, the solid content of the second slurry is 60-70wt%, the particle size of the powder in the second slurry is D50<0.5μm and D90<1μm;

[0021] , and / or the grinding process of step 2 is: grinding time 5-15h, and grinding speed 1200-1800r / min.

[0022] In the above-mentioned preparation method of zinc aluminum oxide target, the die pressing pressure is 25-35Mpa; and the cold isostatic pressing pressure is 110-130MPa.

[0023] In the preparation method of the zinc-aluminum oxide target, the mass ratio of the zinc oxide powder and the aluminum oxide powder is 96-98:2-4.

[0024] The bulk density of the powder obtained in step 3 is 0.87-0.94 g / cm 3 The bulk density of the powder obtained in step 3 is 0.87-0.94 g / cm

[0025] In the preparation method of the zinc-aluminum oxide target, the first dispersant and the second dispersant are independently selected from one or more of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate or sodium hexadecylbenzenesulfonate.

[0026] In the preparation method of the zinc-aluminum oxide target, the amount of the first dispersant is 1-5 wt% of the total weight of the aluminum oxide powder, the first dispersant and water.

[0027] The amount of the second dispersant is 1-15 wt% of the total weight of the zinc oxide powder and the second dispersant.

[0028] In the preparation method of the zinc-aluminum oxide target, the spray granulation process in step 3 is performed by using a spray drying tower, wherein the air outlet temperature is 60-65 DEG C and the frequency of the atomizer is 70 Hz.

[0029] In the preparation method of the zinc-aluminum oxide target, the sintering parameters in step 5 are as follows: the heating rate is 0.5-3 DEG C / min, the temperature is raised to 1100-1400 DEG C, and the temperature is kept for 8-12 h.

[0030] Meanwhile, the application also discloses a zinc-aluminum oxide target prepared by using any of the above methods.

[0031] Advantages

[0032] Compared with the prior art, the application has the following advantages:

[0033] The powder prepared by using the method has different shape and smaller bulk density than the powder prepared by using the conventional method, the powder has larger surface area and the powder particles can be well engaged during the forming, which is helpful for the forming of the target, so that the binder can not be used, thereby saving the cost, and the powder with smaller bulk density can effectively reduce the forming pressure required for the forming and finally converge to the pressure of the process with the binder; meanwhile, the powder with smaller bulk density has smoother surface, and the temperature required for forming the sintering neck during the sintering is higher, and the powder with smaller bulk density can slightly reduce the sintering temperature required for the target.

[0034] The target prepared by using the method has large relative density and low resistivity. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1The spray granulation microscope picture of Example 1 of the present application. DETAILED DESCRIPTION

[0036] The present application is further described in conjunction with the following examples, which do not constitute any limitation to the present application, and any limited number of modifications made within the scope of the claims of the present application are still within the scope of the claims of the present application.

[0037] In order to describe the technical content of the present application in detail, the following further describes in conjunction with the embodiments.

[0038] Example 1

[0039] Step 1: The powders were weighed according to the mass ratio of zinc oxide to aluminum oxide of 97:3 for standby.

[0040] Step 2: A certain amount of pure water was added to the slurry barrel, and the aluminum oxide powder and PVP weighed in step 1 were sequentially added to the slurry barrel for pre-dispersion, the dispersion time was 30 min, and the dispersion rotation speed was 100 rpm, wherein the PVP accounted for 4% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0041] Step 3: The slurry obtained in step 2 was pumped into a sand mill with a pneumatic diaphragm pump for grinding. The grinding time was 10 h, and the grinding rotation speed was 1500 r / min. The slurry one was obtained, and the D50 of the powder in the slurry one was <1 μm, and the D90 was <2.1 μm.

[0042] Step 4: The zinc oxide powder and PVP were added to the slurry one obtained in step 3 for dispersion, the dispersion time was 30 min, and the dispersion rotation speed was 100 rpm. Then the obtained slurry was pumped into a sand mill with a pneumatic diaphragm pump for grinding, the grinding time was 5 h, and the grinding rotation speed was 1500 rpm. The slurry two was obtained, and the particle size of the powder was D50 <0.5 μm, and D90 <1 μm. The PVP accounted for 4% of the total mass of the added zinc oxide powder and PVP.

[0043] Step 5: The slurry two obtained in step 4 was pumped into a spray drying tower for spray granulation, and then was mixed and sieved to obtain the zinc aluminum oxide mixed powder. The air outlet temperature was 65℃, and the atomizer frequency was 70 Hz. The bulk density of the powder was 0.94 g / cm 3 The SEM was observed to observe the powder morphology, and the powder was irregular (see Figure 1 ).

[0044] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain the zinc-aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is subjected to hydraulic pressing at a pressure of 30 MPa in a hydraulic press. After demolding, the zinc-aluminum oxide target blank is obtained. The process parameters of the cold isostatic pressing are as follows: the obtained zinc-aluminum oxide target blank is placed in a soft bag film, which is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid is injected by a high-pressure pump to press at a pressure of 120 MPa, and the zinc-aluminum oxide target blank is obtained.

[0045] Step 7: The target material obtained in step 6 is sintered at a sintering temperature of 1200°C, a heating rate of 2°C / min, and a holding time of 10 h. After cooling, the target material is obtained.

[0046] The measured target material has a relative density of 98.1%, an electrical conductivity of 346 us / cm, no cracks, and easy forming.

[0047] Example 2

[0048] Generally the same as example 1, except that in step 7, the sintering temperature is 1140°C.

[0049] The measured target material has a relative density of 97.9%, an electrical conductivity of 327 us / cm, no cracks, and easy forming.

[0050] Example 3

[0051] Step 1: The powders are weighed according to a mass ratio of zinc oxide to aluminum oxide of 97:3 for use.

[0052] Step 2: A certain amount of pure water is added to the slurry barrel. The aluminum oxide powder and PVP weighed in step 1 are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion speed is 100 rpm. The PVP accounts for 4% of the total mass of the added aluminum oxide powder, pure water, and PVP.

[0053] Step 3: The slurry obtained in step 2 is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 10 h, and the grinding speed is 1500 r / min. Slurry one is obtained.

[0054] Step 4: Zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion speed is 100 rpm. Then the obtained slurry is pumped into a sand mill using a pneumatic diaphragm pump for grinding. The grinding time is 5 h, and the grinding speed is 1500 rpm. Slurry two is obtained. The PVP accounts for 4% of the total mass of the added zinc oxide powder and PVP.

[0055] Step 5: The slurry obtained in step 4 is punched into a spray drying tower for spray granulation, mixing and screening to obtain zinc-aluminum oxide mixed powder. The air outlet temperature is 62°C, and the atomizer frequency is 70 Hz. The powder bulk density is 0.87 g / cm3, and the SEM observation of the powder morphology shows that the powder is irregular.

[0056] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain a zinc-aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, which is then placed in a hydraulic machine for hydraulic pressing at a pressure of 30 MPa. After demolding, a zinc-aluminum oxide target blank is obtained. The cold isostatic pressing process parameters are as follows: the obtained zinc-aluminum oxide target blank is placed in a soft bag film, which is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid is injected by a high-pressure pump for pressing at a pressure of 120 MPa to obtain a zinc-aluminum oxide target blank.

[0057] Step 7: The target material obtained in step 6 is sintered at a sintering temperature of 1200°C, a heating rate of 2°C / min, and a holding time of 10 h. After cooling, a target material is obtained.

[0058] The measured target material has a relative density of 98.6%, an electrical conductivity of 359 us / cm, and no cracks. The target material is easy to form.

[0059] Example 4

[0060] Step 1: The powder is weighed according to the mass ratio of zinc oxide to aluminum oxide of 97:3 for standby use.

[0061] Step 2: A certain amount of pure water is added to the slurry barrel. The aluminum oxide powder and PVP weighed in step (1) are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The PVP accounts for 4% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0062] Step 3: The slurry obtained in step 2 is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 10 h, and the grinding rotation speed is 1500 r / min. Slurry one is obtained.

[0063] Step 4: Zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the obtained slurry is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 5 h, and the grinding rotation speed is 1500 rpm. Slurry two is obtained. The PVP accounts for 4% of the total mass of the added zinc oxide powder and PVP.

[0064] Step 5: The slurry obtained in step 4 is punched into a spray drying tower for spray granulation, mixing and screening to obtain zinc-aluminum oxide mixed powder. The air outlet temperature is 62°C, and the atomizer frequency is 70 Hz. The powder bulk density is 0.88 g / cm 3 SEM observation shows that the powder is irregular.

[0065] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain a zinc-aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 27 MPa. After demolding, a zinc-aluminum oxide target blank is obtained. The cold isostatic pressing process parameters are as follows: the obtained zinc-aluminum oxide target blank is placed in a soft bag film, and the material is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid injected by a high-pressure pump is used for pressing at a pressure of 120 MPa to obtain a zinc-aluminum oxide target blank.

[0066] Step 7: The target material obtained in step 6 is sintered at a sintering temperature of 1200°C, a heating rate of 2°C / min, and a holding time of 10 h. After cooling, a target material is obtained.

[0067] The measured target material has a relative density of 98.3%, an electrical conductivity of 352 us / cm, no cracks, and is easy to form.

[0068] Example 5

[0069] Step 1: The powder is weighed according to the mass ratio of zinc oxide to aluminum oxide of 98:2 for standby use.

[0070] Step 2: A certain amount of pure water is added to the slurry barrel, and the aluminum oxide powder and PVP weighed in step 1 are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The PVP accounts for 2% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0071] Step 3: The slurry obtained in step 2 is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 20 h, and the grinding rotation speed is 1500 r / min. Slurry one is obtained.

[0072] Step 4: Zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the obtained slurry is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 15 h, and the grinding rotation speed is 1500 rpm. Slurry two is obtained. The PVP accounts for 2% of the total mass of the added zinc oxide powder and PVP.

[0073] Step 5: The slurry obtained in step 4 is punched into a spray drying tower for spray granulation, mixing and screening to obtain zinc-aluminum oxide mixed powder. The air outlet temperature is 65°C, and the atomizer frequency is 70 Hz. The powder bulk density is 0.91 g / cm 3 The SEM observation shows that the powder is irregular.

[0074] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain a zinc-aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 30 MPa. After demolding, a zinc-aluminum oxide target blank is obtained. The cold isostatic pressing process parameters are as follows: the obtained zinc-aluminum oxide target blank is placed in a soft bag film, and the material is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid injected by a high-pressure pump is used for pressing at a pressure of 120 MPa to obtain a zinc-aluminum oxide target blank.

[0075] Step 7: The target material obtained in step 6 is sintered at a sintering temperature of 1300°C, a heating rate of 1°C / min, and a holding time of 10 h. After cooling, a target material is obtained.

[0076] The measured target material has a relative density of 98.7%, an electrical conductivity of 364 us / cm, no cracks, and is easy to form.

[0077] Example 6

[0078] Step 1: The powders are weighed according to the mass ratio of zinc oxide to aluminum oxide of 96:4 for standby use.

[0079] Step 2: A certain amount of pure water is added to the slurry barrel, and the aluminum oxide powder and PVP weighed in step 1 are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The PVP accounts for 5% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0080] Step 3: The slurry obtained in step 2 is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 15 h, and the grinding rotation speed is 1500 r / min. Slurry one is obtained.

[0081] Step 4: Zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the obtained slurry is punched into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 10 h, and the grinding rotation speed is 1500 rpm. Slurry two is obtained. The PVP accounts for 15% of the total mass of the added zinc oxide powder and PVP.

[0082] Step 5: The slurry obtained in step 4 is pumped into a spray drying tower for spray granulation, mixing and screening to obtain the zinc-aluminum oxide mixed powder. The air outlet temperature is 65°C, and the atomizer frequency is 70 Hz. The powder bulk density is 0.88 g / cm 3 The SEM observation shows that the powder is irregular.

[0083] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain the zinc-aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 30 MPa. After demolding, the zinc-aluminum oxide target blank is obtained. The cold isostatic pressing process parameters are as follows: the obtained zinc-aluminum oxide target blank is placed in a soft bag film, and the material is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid injected by a high-pressure pump is used for pressing at a pressure of 120 MPa to obtain the zinc-aluminum oxide target blank.

[0084] Step 7: The target material obtained in step 6 is sintered at a sintering temperature of 1400°C, a heating rate of 3°C / min, and a holding time of 10 h. After cooling, the target material is obtained.

[0085] The measured target material has a relative density of 98.5%, an electrical conductivity of 355 us / cm, no cracks, and is easy to form.

[0086] Comparative Example 1

[0087] Step 1: The powder is weighed according to the mass ratio of zinc oxide to aluminum oxide of 97:3 for standby.

[0088] Step 2: A certain amount of pure water is added to the slurry barrel, and the aluminum oxide powder and PVP weighed in step 1 are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The PVP accounts for 4% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0089] Step 3: The slurry obtained in step 2 is pumped into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 10 h, and the grinding rotation speed is 1500 r / min. The slurry one is obtained.

[0090] Step 4: The slurry one obtained in step 3 is added with zinc oxide powder and PVP for dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the obtained slurry is pumped into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 5 h, and the grinding rotation speed is 1500 rpm. The slurry two is obtained. The PVP accounts for 4% of the total mass of the added zinc oxide powder and PVP.

[0091] Step 5: The slurry obtained in step 5 is pumped into a spray drying tower for spray granulation, and then mixed and sieved to obtain a mixed powder. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz. The bulk density of the powder is 1.47 g / cm3, and the SEM is observed to show that the powder is nearly spherical.

[0092] Step 6: The mixed powder obtained in step 5 is subjected to die pressing and cold isostatic pressing to obtain a zinc aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 30 MPa. After demolding, the target material is broken and not formed.

[0093] Comparative Example 2

[0094] Step 1: The powders are weighed according to the mass ratio of zinc oxide to aluminum oxide of 97:3 for later use.

[0095] Step 2: A certain amount of pure water is added to the slurry tank, and the aluminum oxide powder and PVP weighed in step (1) are sequentially added to the slurry tank for pre-dispersion. The dispersion time is 30 min, and the dispersion speed is 100 rpm. The PVP accounts for 4% of the total mass of the added aluminum oxide powder, pure water and PVP.

[0096] Step 3: The slurry obtained in step 2 is pumped into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 10 h, and the grinding speed is 1500 r / min to obtain slurry one.

[0097] Step 4: The zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion speed is 100 rpm. Then the obtained slurry is pumped into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 5 h, and the grinding speed is 1500 rpm to obtain slurry two. The PVP accounts for 4% of the total mass of the added zinc oxide powder and PVP.

[0098] Step 5: The PVA is added to the slurry two obtained in step 4 for pre-dispersion. The pre-dispersion time is 30 min, and the dispersion speed is 100 rpm. Then the slurry is pumped into a sand mill for grinding by a pneumatic diaphragm pump. The grinding time is 1 h, and the grinding speed is 1500 rpm to obtain slurry three. The binder PVA accounts for 10% of the total mass of the added zinc oxide powder, aluminum oxide and binder.

[0099] Step 6: The slurry three obtained in step 5 is pumped into a spray drying tower for spray granulation, and then mixed and sieved to obtain a tin-doped niobium oxide mixed powder. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz. The bulk density of the powder is 1.46 g / cm3, and the SEM is observed to show that the powder is nearly spherical.

[0100] Step 7: The mixed powder obtained in step 6 is subjected to die pressing and cold isostatic pressing to obtain the zinc aluminum oxide target blank. The die pressing process is as follows: the mixed powder is loaded into a 120 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 30 MPa. After demolding, the zinc aluminum oxide target blank is obtained, and the edges of the target blank are prone to falling off. The process parameters of the cold isostatic pressing are as follows: the obtained zinc aluminum oxide target blank is placed in a soft bag film, and the material is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid is injected by a high-pressure pump for pressing at a pressure of 120 MPa to obtain the zinc aluminum oxide target blank.

[0101] Step 8: The target material obtained in step 7 is subjected to debinding at a temperature of 500°C for 5 hours.

[0102] Step 9: The target material obtained in step 8 is subjected to sintering at a sintering temperature of 1200°C, a heating rate of 2° / min, and a holding time of 10 hours. After cooling, the target material is obtained.

[0103] The measured target material has a relative density of 97.6%, an electrical conductivity of 313 us / cm, and no large cracks, and is easy to form.

[0104] Comparative Example 3

[0105] Step 1: The powders are weighed according to a mass ratio of zinc oxide to aluminum oxide of 97:3 for standby use.

[0106] Step 2: A certain amount of pure water is added to the slurry barrel, and the aluminum oxide powder and PVP weighed in step 1 are sequentially added to the slurry barrel for pre-dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The PVP accounts for 4% of the total mass of the added aluminum oxide powder, pure water, and PVP.

[0107] Step 3: The slurry obtained in step 2 is pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time is 10 h, and the grinding rotation speed is 1500 r / min. Slurry one is obtained.

[0108] Step 4: Zinc oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion. The dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the obtained slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time is 5 h, and the grinding rotation speed is 1500 rpm. Slurry two is obtained. The PVP accounts for 4% of the total mass of the added zinc oxide powder and PVP.

[0109] Step 5: The slurry two obtained in step 4 was pre-dispersed after adding PVA, the pre-dispersing time was 30 min, and the dispersing rotation speed was 100 rpm. Then the slurry was pumped into a sand mill by a pneumatic diaphragm pump for grinding, the grinding time was 1 h, and the grinding rotation speed was 1500 rpm to obtain slurry three. The binder PVA accounted for 10% of the total mass of the zinc oxide powder, aluminum oxide and binder added.

[0110] Step 6: The slurry three obtained in step 5 was pumped into a spray drying tower for spray granulation, and then was mixed and sieved to obtain a tin oxide doped niobium oxide mixed powder. The air outlet temperature was 75°C, and the atomizer frequency was 120 Hz. The powder bulk density was 1.46 g / cm3, and the SEM observation of the powder morphology showed that the powder was nearly spherical.

[0111] Step 7: The mixed powder obtained in step 6 was subjected to die pressing and cold isostatic pressing to obtain a zinc aluminum oxide target blank. The die pressing process was as follows: the mixed powder was loaded into a 120 mm mold, and then was subjected to hydraulic pressing at a pressure of 30 MPa in a hydraulic machine. After demolding, a zinc aluminum oxide target blank was obtained, and the edge of the target blank was prone to falling off. The cold isostatic pressing process parameters were as follows: the obtained zinc aluminum oxide target blank was placed in a soft bag film, the material of which was generally a PE plastic bag. The sealed bag was placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The target blank was pressed by high-pressure liquid injected by a high-pressure pump, and the pressure was 120 MPa to obtain a zinc aluminum oxide target blank.

[0112] Step 8: The target material obtained in step 7 was subjected to debinding at a temperature of 500°C for 5 h.

[0113] Step 9: The target material obtained in step 8 was subjected to sintering at a sintering temperature of 1200°C, a heating rate of 2° / min and a holding time of 10 h. After cooling, a target material was obtained.

[0114] The measured target material had a relative density of 98.3%, an electrical conductivity of 344 us / cm, and no large cracks, and the forming was relatively easy.

[0115] Comparative Example 4

[0116] Step 1: The powders were weighed according to a mass ratio of zinc oxide to aluminum oxide of 97:3 for standby use.

[0117] Step 2: A certain amount of pure water was added to a slurry tank, and the aluminum oxide powder and PVP weighed in step (1) were sequentially added to the slurry tank for pre-dispersing, the dispersing time was 30 min, and the dispersing rotation speed was 100 rpm. The PVP accounted for 4% of the total mass of the aluminum oxide powder, pure water and PVP added.

[0118] Step 3: The slurry obtained in step 2 was pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time was 10 h, and the grinding speed was 1500 r / min. The slurry 1 was obtained.

[0119] Step 4: The slurry 1 obtained in step 3 was added with zinc oxide powder and PVP for dispersion. The dispersion time was 30 min, and the dispersion speed was 100 rpm. Then the slurry was pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time was 5 h, and the grinding speed was 1500 r / min. The slurry 2 was obtained. The PVP accounted for 4% of the total mass of the added zinc oxide powder and PVP.

[0120] Step 5: The slurry 2 obtained in step 4 was added with PVA for pre-dispersion. The pre-dispersion time was 30 min, and the dispersion speed was 100 rpm. Then the slurry was pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time was 1 h, and the grinding speed was 1500 r / min. The slurry 3 was obtained. The binder accounted for 10% of the total mass of the added zinc oxide powder, aluminum oxide and binder.

[0121] Step 6: The slurry 2 obtained in step 4 was pumped into a spray drying tower for spray granulation, and then was mixed and sieved to obtain a zinc oxide aluminum mixed powder. The air outlet temperature was 62℃, and the atomizer frequency was 70 Hz. The bulk density of the powder was 0.90 g / cm 3 The SEM observation showed that the powder had an irregular shape.

[0122] Step 7: The mixed powder obtained in step 6 was subjected to die pressing and cold isostatic pressing to obtain a zinc oxide aluminum target blank. The die pressing process was as follows: the mixed powder was loaded into a 120 mm mold, and then was subjected to hydraulic pressing at a pressure of 20 MPa in a hydraulic machine. After demolding, the zinc oxide aluminum target blank was obtained, and the edge of the target blank was prone to fall off. The cold isostatic pressing process parameters were as follows: the obtained zinc oxide aluminum target blank was placed in a soft bag film, and the material was generally a PE plastic bag. The sealed bag was placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid injected by a high-pressure pump was used for pressing at a pressure of 100 MPa to obtain the zinc oxide aluminum target blank.

[0123] Step 8: The target material obtained in step 7 was subjected to debinding at a temperature of 500℃ for 5 h.

[0124] Step 9: The target material obtained in step 8 was subjected to sintering at a sintering temperature of 1200℃ at a heating rate of 2℃ / min for 10 h. After cooling, the target material was obtained.

[0125] The measured target material had a relative density of 98.0%, an electrical conductivity of 342 us / cm, and no large cracks. The target material was easy to form.

[0126] Comparative Example 5

[0127] Comparative Example 4 was substantially the same as Comparative Example 3, except that:

[0128] Step 9: The target material obtained in Step 8 was sintered at a temperature of 1140°C at a heating rate of 2°C / min for 10 h, and then cooled to obtain the target material.

[0129] The measured target material had a relative density of 97.1% and an electrical conductivity of 281 us / cm, and the target material had no large cracks and was easy to form.

[0130] Results analysis:

[0131] 1. From the comparison of Examples 1-6 and Comparative Example 1, it can be seen that controlling the spray density and surface morphology is the key to the present application, and in the specification of the present application, no binder is used.

[0132] 2. From Examples 1 and 2, it can be seen that the sintering temperature of the present application can be as low as 1140°C.

[0133] From Comparative Examples 4 and 5, it can be seen that in the case of using a binder, the electrical conductivity is significantly reduced at a sintering temperature of 1140°C.

[0134] 3. From the comparison of Comparative Examples 2-4, it can be seen that in the case of using a binder, the specification of the spray granulation is not limited, as long as the two powders are uniformly mixed, and the product meeting the requirements can be obtained by molding and cold isostatic pressing.

[0135] The examples presented herein are only selected from all possible combinations of embodiments. The appended claims should not be limited by the embodiments described herein. Some numerical ranges used in the claims include sub-ranges within them, and variations in these ranges should also be covered by the appended claims.

Claims

1. A method for preparing a zinc oxide aluminum target, characterized in that, Includes the following steps: Step 1: Mix alumina powder, the first dispersant, and water to form a slurry and grind it to obtain the first slurry; Step 2: Mix the first slurry, zinc oxide powder, and second dispersant to form a slurry and grind it to obtain the second slurry; Step 3: Use a second slurry spray granulation method to obtain a loose bulk density of 0.87-0.94 g / cm³. 3 powder; Step 4: The powder obtained in Step 3 is subjected to molding and cold isostatic pressing to obtain zinc oxide aluminum target blank; Step 5: Sinter the zinc oxide aluminum target blank to obtain the zinc oxide aluminum target material; The mass ratio of zinc oxide powder to aluminum oxide powder is 96-98:2-4; The spray granulation process in step 3 is as follows: spray drying tower is used for spray granulation, wherein the outlet air temperature is 60-65℃ and the atomizer frequency is 70Hz. The sintering parameters for step 5 are: a heating rate of 2℃ / min, heating to 1140~1200℃, and holding at that temperature for 10h.

2. The method for preparing the zinc oxide aluminum target according to claim 1, characterized in that, The first slurry has a solid content of 60-70 wt%, and the particle size of the powder in the first slurry is D50 < 1 μm and D90 < 2.1 μm. The grinding process in step 1 is as follows: grinding time 10-22h, grinding speed 1200-1800r / min.

3. The method for preparing the zinc oxide aluminum target according to claim 1, characterized in that, The solid content of the second slurry is 60-70 wt%, and the particle size of the powder in the second slurry is D50 < 0.5 μm and D90 < 1 μm; The grinding process in step 2 is as follows: grinding time is 5-15 hours, and grinding speed is 1200-1800 r / min.

4. The method for preparing the zinc oxide aluminum target according to claim 1, characterized in that, The molding pressure is 25-35 MPa; the cold isostatic pressing pressure is 110-130 MPa.

5. The method for preparing the zinc oxide aluminum target according to claim 1, characterized in that, The first dispersant and the second dispersant are each independently selected from one or more of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate or sodium hexadecylbenzenesulfonate.

6. The method for preparing the zinc oxide aluminum target according to claim 3, characterized in that, The amount of the first dispersant is equivalent to 1-5 wt% of the total weight of alumina powder, the first dispersant, and water. The amount of the second dispersant is equivalent to 1-15 wt% of the total weight of the zinc oxide powder and the second dispersant.

7. A zinc oxide aluminum target material, characterized in that, It is prepared by the method described in any one of claims 1-6.

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