A tin oxide niobium target and a method for manufacturing the same

Abstract

The application belongs to the technical field of semiconductors, and discloses a preparation method of a tin oxide niobium target material, which uses tin oxide and niobium oxide as raw materials to prepare the tin oxide niobium target material; the niobium oxide is at least one of Nb2O5, Nb2O4 and Nb2O3. The method uses niobium oxide with multiple valence states as raw materials, so that most of the final product is pentavalent niobium oxide and a small amount of trivalent and tetravalent niobium oxide, and the conductivity of the product can be improved. Meanwhile, the application also provides the tin oxide niobium target material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a tin oxide niobium 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, the display target material and the 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, the flat panel display technologies such as liquid crystal display, active organic light emitting diode display and flexible display have developed rapidly, and the importance of thin film transistor (TFT) as a core component 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] SnO2 is a wide-band metal oxide semiconductor material with a direct band gap, and SnO2 ceramic material has always been a research hotspot. It has broad application prospects in gas sensing, liquid crystal display, light detector, solar cell, photocatalysis, electrocatalysis and protective coating.

[0004] CN116655372A discloses a tin oxide-based target material and a preparation method thereof, which discloses that the doping raw material includes niobium oxide and / or tantalum oxide.

[0005] It does not disclose the valence state of niobium oxide.

[0006] In subsequent research, it was found that the low-valence niobium oxide does contribute to the conductivity of the tin oxide niobium target material.

[0007] Therefore, the technical problem to be solved by the present application is how to obtain a tin oxide niobium target material with high conductivity. SUMMARY

[0008] One of the purposes of the present application is to provide a preparation method of a tin oxide niobium target material. The method uses niobium oxide with multiple valence states as raw material, so that most of the final product is pentavalent niobium oxide and a small amount of trivalent and tetravalent niobium oxide, which can improve the conductivity of the product.

[0009] Meanwhile, the present application also provides the tin oxide niobium target material.

[0010] M is mol / L, and % is mass percentage, unless otherwise specified in the present application.

[0011] To achieve the above object, the present application provides a preparation method of a tin niobium oxide target material.

[0012] The niobium oxide is at least one of Nb2O5, Nb2O4 and Nb2O3.

[0013] It should be noted that the low-valence element of niobium between the product and the raw material of the present application will be significantly reduced, but a small amount of low-valence niobium will be contained in the product, which can provide more free electrons, thereby improving the electrical conductivity.

[0014] In the above preparation method of the tin niobium oxide target material, the molar ratio of the Nb2O5, Nb2O4 and Nb2O3 is 1:1.5-3:3.5-5.

[0015] In the above preparation method of the tin niobium oxide target material, the method is specifically as follows:

[0016] Step 1: mixing and grinding niobium oxide and a dispersing agent to obtain a first slurry;

[0017] Step 2: mixing and grinding tin oxide, a dispersing agent and the first slurry to obtain a second slurry;

[0018] Step 3: mixing and grinding a binder and the second slurry to obtain a third slurry;

[0019] Step 4: spray granulating the third slurry to obtain a tin oxide doped niobium oxide mixed powder;

[0020] Step 5: mixing the tin oxide doped niobium oxide mixed powder in a mixer under the protection of an inert gas to obtain a mixed powder;

[0021] Step 6: preparing a target blank from the mixed powder;

[0022] Step 7: placing the target blank into a sintering furnace to sinter the target blank.

[0023] In the above preparation method of the tin niobium oxide target material, the grinding time of step 1, step 2 and step 3 is 3-8h, 3-8h and 1-3h, respectively.

[0024] In the above preparation method of the tin niobium oxide target material, the dispersing agent used in step 1 and step 2 is polyvinylpyrrolidone, sodium dodecylbenzenesulfonate or sodium cetylbenzenesulfonate.

[0025] The binder used in step 3 is a mixture of polyvinyl alcohol and polyethylene glycol, polyvinyl alcohol or polyvinyl butyral.

[0026] In the preparation method of the tin oxide niobium target material, the step 5 is specifically:

[0027] The tin oxide doped niobium oxide mixed powder is put into a mixer for mixing, nitrogen is filled into the mixer during the mixing, the gas flow is 0.1-0.3L / min, the rotating speed is 30rpm / min, and the mixed powder is obtained after mixing for 30min.

[0028] In the preparation method of the tin oxide niobium target material, the step 7 is specifically: the target blank is put into a sintering furnace for sintering, under the conditions of vacuum or inert gas protection, the temperature is controlled at 400-600℃ at a heating rate of 0.1-0.5 / min, the temperature is kept for 6-12h, then the temperature is raised to 1100-1600℃ at a heating rate of 0.5-1.5℃ / min, and the temperature is kept for 8-12h to obtain the target material.

[0029] Meanwhile, the application also discloses a tin oxide niobium target material prepared by the method.

[0030] Beneficial effects

[0031] Compared with the prior art, the application has the following advantages:

[0032] The niobium oxide used in the application is a mixture of Nb2O5, Nb2O4 and Nb2O3, which can provide more free electrons, thereby improving the conductivity.

[0033] In the preparation process of the application, the pulp preparation, mixing and degreasing processes will cause the oxidation of tetravalent and trivalent niobium to pentavalent niobium, and the low-valence elements of niobium between the product and the raw material will be significantly reduced, but a small amount of low-valence niobium will be contained in the product, which can provide more free electrons, thereby improving the conductivity.

[0034] In a further preferred embodiment of the application, the factors causing the oxidation of niobium can be further controlled to have more low-valence niobium in the product, specifically, by reducing the grinding time of pulp preparation and inert gas protection mixing, the niobium oxide is not easily oxidized to pentavalent niobium, thereby further improving the conductivity. Specific implementation

[0035] The application will be further described below in conjunction with the examples, but does not constitute any limitation on the application, and any limited modifications made within the scope of the claims of the application are still within the scope of the claims of the application.

[0036] In order to explain the technical content of the present application in detail, further description is made below in combination with the embodiments.

[0037] Embodiment 1

[0038] Step 1: SnO2 and Nb2O5 powder are weighed according to the ratio of 97.5:2.5.

[0039] The molar ratio of Nb2O5, Nb2O4 and Nb2O3 in the Nb2O5 powder is 1:3.5:5.

[0040] Step 2: A certain amount of pure water is added to the slurry barrel, and the Nb2O5 powder weighed in step (1) and PVP 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 Nb2O5 powder, pure water and PVP.

[0041] 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 3 h, and the grinding rotation speed is 1500 r / min. The slurry one is obtained.

[0042] Step 4: SnO2 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. The slurry two is obtained. The PVP accounts for 4% of the total mass of the added SnO2 powder and PVP.

[0043] Step 5: PVA is added to the slurry two obtained in step 4 for pre-dispersion. The pre-dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding. The grinding time is 1 h, and the grinding rotation speed is 1500 rpm. The slurry three is obtained. The binder accounts for 10% of the total mass of the added SnO2 powder, Nb2O5 and binder.

[0044] Step 6: The slurry three obtained in step 5 is pumped into a spray drying tower for spray granulation, followed by mixing and sieving to obtain SnO2 doped Nb2O5 mixed powder. The air outlet temperature is 75℃, and the atomizer frequency is 120 Hz.

[0045] Step 7: The mixed powder obtained in step 6 is put into a mixer for mixing. Nitrogen gas is filled into the mixer during mixing. The gas flow is 0.3 L / min, and the rotation speed is 30 rpm / min. After mixing for 30 min, the qualified mixed powder is obtained.

[0046] Step 8: The mixed powder obtained in step 7 is formed by die pressing and cold isostatic pressing to obtain a SnO2 doped Nb2O5 target blank.

[0047] The molding process is as follows: the mixed powder is loaded into a 50-300mm mold, and then put into a hydraulic machine to be hydraulically pressed at a pressure of 15-80Mpa, and after demolding, a tin niobium oxide target blank is obtained.

[0048] The process parameters of the cold isostatic pressing are as follows: the obtained tin niobium oxide target blank is put into a soft bag film, the material of which is generally a PE plastic bag, the sealed bag is put into a cold isostatic pressing machine and soaked in a liquid pressure medium, and then pressed by high-pressure liquid injected by a high-pressure pump, the pressure being 360MPa-400MPa, and a tin niobium oxide target blank is obtained.

[0049] Step 9: the target blank obtained in step 8 is put into a sintering furnace for vacuum sintering, the temperature is controlled at 500℃ at a heating rate of 0.5 / min, and after holding for 8h, the temperature is raised to 1200℃ at a heating rate of 1℃ / min and held for 10h. A target material is obtained.

[0050] The density of the target material obtained in step 9 is tested, and the relative density is 98.29%, the electrical conductivity is 294s / cm, and the valence state of the niobium element is measured by XPS, which includes +5 valence niobium, +4 valence niobium and +3 valence niobium, and +5 valence niobium is mainly present.

[0051] Example 2

[0052] Step 1: tin oxide and niobium oxide powders are weighed according to a molar ratio of 98.5:1.5 for standby use.

[0053] The molar ratio of Nb2O5, Nb2O4 and Nb2O3 in the niobium oxide is 1:2.5:3.5;

[0054] Step 2: a certain amount of pure water is added to the slurry barrel, and the niobium oxide powder and PVP weighed in step (1) are sequentially added to the slurry barrel for pre-dispersion, the dispersion time is 30min, and the dispersion rotation speed is 100rpm, wherein the PVP accounts for 4% of the total mass of the added niobium oxide powder, pure water and PVP.

[0055] 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 3h, and the grinding rotation speed is 1500r / min, and slurry one is obtained.

[0056] Step 4: tin oxide powder and PVP are added to the slurry one obtained in step 3 for dispersion, the dispersion time is 30min, and the dispersion rotation speed is 100rpm. Then the obtained slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding, the grinding time is 5h, and the grinding rotation speed is 1500rpm, and slurry two is obtained. The PVP accounts for 4% of the total mass of the added tin oxide powder and PVP.

[0057] Step 5: The slurry two obtained in step 4 is pre-dispersed after adding PVA, the pre-dispersing time is 30 min, the dispersing rotation speed is 100 rpm, then the slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding, the grinding time is 1 h, the grinding rotation speed is 1500 rpm, to obtain slurry three. The binder accounts for 10% of the total mass of the tin oxide powder, niobium oxide and binder added.

[0058] Step 6: The slurry three obtained in step 5 is pumped into a spray drying tower for spray granulation, then mixing and screening are performed to obtain a tin oxide doped niobium oxide mixed powder. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz.

[0059] Step 7: The mixed powder obtained in step 6 is put into a mixer for mixing, nitrogen is filled into the mixer during mixing, the gas flow is 0.3 L / min, the rotation speed is 30 rpm / min, and the qualified mixed powder is obtained after mixing for 30 min.

[0060] Step 8: The mixed powder obtained in step 7 is molded by die pressing and cold isostatic pressing to obtain a tin oxide doped niobium oxide target blank;

[0061] The die pressing process is as follows: the mixed powder is loaded into a 50-300 mm mold, then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa, and the tin oxide niobium target blank is obtained after demolding.

[0062] The process parameters of the cold isostatic pressing are as follows: the obtained tin oxide niobium target blank is placed in a soft bag film, 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, and the blank is pressed by high-pressure liquid injected by a high-pressure pump, the pressure is 360 MPa-400 MPa, and the tin oxide niobium target blank is obtained.

[0063] Step 9: The target blank obtained in step 8 is placed in a sintering furnace for vacuum sintering, the temperature is controlled at 500°C at a heating rate of 0.5 / min, the temperature is kept for 8 h, the temperature is raised to 1200°C at a heating rate of 1°C / min, and the temperature is kept for 10 h. The target material is obtained.

[0064] The density of the target material obtained in step 10 is tested, the relative density is 98.14%, the electrical conductivity is 289 s / cm, the valence state of the niobium element is measured by XPS, which includes +5 valence niobium, +4 valence niobium and +3 valence niobium, and +5 valence niobium is mainly present.

[0065] Example 3

[0066] Step 1: Tin oxide and niobium oxide powders are weighed according to a molar ratio of 97.5:2.5 for standby use.

[0067] The molar ratio of Nb2O5, Nb2O4 and Nb2O3 in the niobium oxide is 1:3:5;

[0068] Step 2: A certain amount of pure water is added into the slurry tank, and the weighed niobium oxide powder and PVP in step (1) are sequentially added into the slurry tank for pre-dispersion, the dispersion time is 30 min, and the dispersion rotation speed is 100 rpm, wherein the PVP accounts for 4% of the total mass of the added niobium oxide powder, pure water and PVP.

[0069] 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 3h, and the grinding rotation speed is 1500r / min, to obtain slurry one.

[0070] Step 4: Tin 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 5h, and the grinding rotation speed is 1500rpm, to obtain slurry two. The PVP accounts for 4% of the total mass of the added tin oxide powder and PVP.

[0071] Step 5: PVA is added to the slurry two obtained in step 4 for pre-dispersion, the pre-dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. Then the slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding, the grinding time is 1h, and the grinding rotation speed is 1500rpm, to obtain slurry three. The binder accounts for 10% of the total mass of the added tin oxide powder, niobium oxide and binder.

[0072] Step 6: The slurry three obtained in step 5 is pumped into a spray drying tower for spray granulation, and then is subjected to mixing and screening to obtain a tin oxide doped niobium oxide mixed powder. The air outlet temperature is 75℃, and the atomizer frequency is 120Hz.

[0073] Step 7: The mixed powder obtained in step 6 is put into a mixer for mixing, nitrogen gas is filled into the mixer during mixing, the gas flow is 0.2L / min, the rotation speed is 30rpm / min, and the qualified mixed powder is obtained after mixing for 30 min.

[0074] Step 8: The mixed powder obtained in step 7 is formed by die pressing and cold isostatic pressing to obtain a tin oxide doped niobium oxide target blank;

[0075] The die pressing process is as follows: the mixed powder is loaded into a 50-300mm mold, and then is subjected to hydraulic pressing in a hydraulic machine at a pressure of 15-80Mpa to obtain a tin oxide niobium target blank.

[0076] The process parameters of the cold isostatic pressing are as follows: the obtained tin oxide niobium target blank is put into a soft bag film, the material is generally a PE plastic bag, the sealed bag is put into a cold isostatic pressing machine and soaked in a liquid pressure medium, and the blank is pressed by high-pressure liquid injected by a high-pressure pump, the pressure is 360 MPa-400 MPa, and the tin oxide niobium target blank is obtained.

[0077] Step 9: The target blank obtained in step 8 is put into a sintering furnace for vacuum sintering, the temperature is controlled at 500 DEG C at a heating rate of 0.5 / min, and after holding for 8h, the temperature is raised to 1200 DEG C at a heating rate of 1 DEG C / min, and holding for 10h. The target material is obtained.

[0078] The density of the target material obtained in step 10 is tested, the relative density is 98.18%, the conductivity is 291s / cm, the valence state of the niobium element is measured by XPS, which includes +5 valence niobium, +4 valence niobium and +3 valence niobium, and +5 valence niobium is mainly present.

[0079] Example 4

[0080] Generally the same as example 1, except that the grinding time of step 3, step 4, step 5 is 8h, 8h, 3h respectively.

[0081] Example 5

[0082] Generally the same as example 1, except that the grinding time of step 3, step 4, step 5 is 3h, 3h, 1h respectively.

[0083] Example 6

[0084] Step 1: Tin oxide and niobium oxide powder are weighed according to the molar ratio of 97.5:2.5 for standby.

[0085] The molar ratio of Nb2O5, Nb2O4 and Nb2O3 in niobium oxide is 1:2:4;

[0086] Step 2: A certain amount of pure water is added to the slurry barrel, and the niobium oxide powder and PVP weighed in step (1) are sequentially added to the slurry barrel for pre-dispersion, the dispersion time is 30min, and the dispersion rotation speed is 100rpm, wherein the PVP accounts for 4% of the total mass of the added niobium oxide powder, pure water and PVP.

[0087] 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 3h, the grinding rotation speed is 1500r / min, and the slurry one is obtained.

[0088] Step 4: The slurry obtained in step 3 was dispersed by adding tin oxide powder and PVP, and the dispersion time was 30 min and the dispersion rotation speed was 100 rpm. Then the obtained slurry was pumped into a sand mill by a pneumatic diaphragm pump for grinding, and the grinding time was 5 h and the grinding rotation speed was 1500 rpm to obtain slurry 2. The PVP accounted for 4% of the total mass of the added tin oxide powder and PVP.

[0089] Step 5: The slurry 2 obtained in step 4 was pre-dispersed by adding PVA, and the pre-dispersion time was 30 min and the dispersion rotation speed was 100 rpm. Then the slurry was pumped into a sand mill by a pneumatic diaphragm pump for grinding, and the grinding time was 1 h and the grinding rotation speed was 1500 rpm to obtain slurry 3. The binder accounted for 10% of the total mass of the added tin oxide powder, niobium oxide and binder.

[0090] Step 6: The slurry 3 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.

[0091] Step 7: The mixed powder obtained in step 6 was formed by molding and cold isostatic pressing to obtain a tin oxide doped niobium oxide target blank.

[0092] The molding process was as follows: the mixed powder was loaded into a 50-300 mm mold, and then was placed into a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, a tin niobium oxide target blank was obtained.

[0093] The process parameters of the cold isostatic pressing were as follows: the obtained tin niobium oxide target blank was placed into a soft bag film, and the material was generally a PE plastic bag. The sealed bag was placed into 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 360 MPa-400 MPa to obtain a tin niobium oxide target blank.

[0094] Step 8: The target blank obtained in step 7 was placed into a sintering furnace for debinding heat treatment. The heating rate was 0.5 / min, the temperature was controlled at 500°C, the holding time was 8 h, and then the target blank was cooled to room temperature to remove the additives and other organic matters in the target blank.

[0095] Step 9: The target blank obtained in step 8 was placed into a sintering furnace for vacuum sintering. The heating rate was 1°C / min, the temperature was raised to 1200°C, and then the temperature was maintained for 10 h to obtain a target material.

[0096] The density of the target material obtained in step 9 was tested, and the relative density was 95.26%, the electrical conductivity was 138 s / cm, and the valence state of the niobium element was measured by XPS, and all were +5 valence niobium.

[0097] Example 7

[0098] Step 1: Tin oxide, niobium oxide powder were weighed according to the ratio of 97.5:2.5.

[0099] The molar ratio of Nb2O5, Nb2O4, Nb2O3 in niobium oxide is 1:2:4;

[0100] Step 2: A certain amount of pure water was added to the slurry barrel, and the niobium 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 speed was 100 rpm, wherein the PVP accounted for 4% of the total mass of the added niobium oxide powder, pure water and PVP.

[0101] 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 8h, the grinding speed was 1500r / min, and the slurry one was obtained.

[0102] Step 4: Tin 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 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 12h, the grinding speed was 1500rpm, and the slurry two was obtained. The PVP accounted for 4% of the total mass of the added tin oxide powder and PVP.

[0103] Step 5: PVA was added to the slurry two obtained in step 4 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 with a pneumatic diaphragm pump for grinding, the grinding time was 5h, the grinding speed was 1500rpm, and the slurry three was obtained. The binder accounted for 10% of the total mass of the added tin oxide powder, niobium oxide and binder.

[0104] Step 6: The slurry three obtained in step 5 was pumped into a spray drying tower for spray granulation, then mixed and sieved to obtain a tin oxide doped niobium oxide mixed powder. The outlet air temperature was 75℃, and the atomizer frequency was 120Hz.

[0105] Step 7: The mixed powder obtained in step 6 was put into a mixer for mixing, nitrogen was filled into the mixer during mixing, the gas flow was 0.3L / min, the rotation speed was 30rpm / min, and the qualified mixed powder was obtained after mixing for 30min.

[0106] Step 8: The mixed powder obtained in step 7 was formed by molding and cold isostatic pressing to obtain a tin oxide doped niobium oxide target blank;

[0107] The molding process is as follows: the mixed powder is loaded into a 50-300mm mold, and then the mold is placed into a hydraulic machine to be hydraulically pressed at a pressure of 15-80Mpa, and after demolding, a tin niobium oxide target blank is obtained.

[0108] The process parameters of the cold isostatic pressing are as follows: the obtained tin niobium oxide target blank is placed into a soft bag film, and the material is generally a PE plastic bag, the sealed bag is placed into a cold isostatic pressing machine and soaked in a liquid pressure medium, and the blank is pressed by high-pressure liquid injected by a high-pressure pump, and the pressure is 360MPa-400MPa, and a tin niobium oxide target blank is obtained.

[0109] Step 9: The target blank obtained in step 7 is placed into a sintering furnace for debinding heat treatment, and the temperature is controlled at 500℃ at a heating rate of 0.5 / min in an air atmosphere, and after heat preservation for 8h, the target blank is cooled to room temperature to remove additives and other organic matters in the target blank.

[0110] Step 10: The target blank obtained in step 8 is placed into a sintering furnace for vacuum sintering, and the heating rate is 1℃ / min, and after the temperature is raised to 1200℃, the target blank is heat preserved for 10h, and a target material is obtained.

[0111] The density of the target material obtained in step 10 is tested, and the relative density is 98.18%, the electrical conductivity is 163s / cm, and the valence state of the niobium element is measured by XPS, and most of the niobium element is +5 valence niobium, +4 valence niobium and +3 valence niobium, and the content of +3 valence niobium is very small.

[0112] Example 8

[0113] Step 1: Tin oxide and niobium oxide powders are weighed according to a molar ratio of 97.5:2.5 for standby.

[0114] The molar ratio of Nb2O5, Nb2O4 and Nb2O3 in the niobium oxide is 1:3:4;

[0115] Step 2: A certain amount of pure water is added to the slurry barrel, and the niobium oxide powder and PVP weighed in step (1) are sequentially added to the slurry barrel for pre-dispersion, the dispersion time is 30min, and the dispersion rotation speed is 100rpm, wherein the PVP accounts for 4% of the total mass of the added niobium oxide powder, pure water and PVP.

[0116] 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 3h, and the grinding rotation speed is 1500r / min, and slurry one is obtained.

[0117] Step 4: The slurry obtained in step 3 is dispersed by adding tin oxide powder and PVP, and 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, and the grinding time is 5 h and the grinding rotation speed is 1500 rpm to obtain slurry 2. The PVP accounts for 4% of the total mass of the added tin oxide powder and PVP.

[0118] Step 5: The slurry 2 obtained in step 4 is pre-dispersed by adding PVA, and the pre-dispersion time is 30 min and the dispersion rotation speed is 100 rpm. Then the slurry is pumped into a sand mill by a pneumatic diaphragm pump for grinding, and the grinding time is 1 h and the grinding rotation speed is 1500 rpm to obtain slurry 3. The binder accounts for 10% of the total mass of the added tin oxide powder, niobium oxide and binder.

[0119] Step 6: The slurry 3 obtained in step 5 is pumped into a spray drying tower for spray granulation, and then mixed and sieved to obtain a tin oxide doped niobium oxide mixed powder. The air outlet temperature is 75°C and the atomizer frequency is 120 Hz.

[0120] Step 7: The mixed powder obtained in step 6 is put into a mixer for mixing, and nitrogen is filled into the mixer during mixing, the gas flow is 0.5 L / min, the rotation speed is 30 rpm / min, and the qualified mixed powder is obtained after mixing for 30 min.

[0121] Step 8: The mixed powder obtained in step 7 is formed by molding and cold isostatic pressing to obtain a tin oxide doped niobium oxide target blank;

[0122] The molding process is as follows: the mixed powder is loaded into a 50-300 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, a tin niobium oxide target blank is obtained.

[0123] The process parameters of the cold isostatic pressing are as follows: the obtained tin niobium oxide target blank is placed in a soft bag film, 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, and the blank is pressed by high-pressure liquid injected by a high-pressure pump, and the pressure is 360 MPa-400 MPa to obtain a tin niobium oxide target blank.

[0124] Step 9: The target blank obtained in step 8 is placed in a sintering furnace for vacuum sintering, the temperature is controlled at 500°C at a heating rate of 0.5 / min, and the temperature is kept for 8 h. The temperature is raised to 1200°C at a heating rate of 1°C / min, and the temperature is kept for 10 h to obtain a target material.

[0125] The density of the target material obtained in step 9 was tested, and the relative density was 98.15%, the conductivity was 291 s / cm, and the valence state of the niobium element was measured using XPS, which included +5 valence niobium, +4 valence niobium, and +3 valence niobium, and the +5 valence niobium was the main existence.

[0126] Example 9

[0127] The general procedure was the same as that of Example 1, except that the niobium oxide was Nb2O5 and Nb2O4, and the molar ratio of the two was 1:3.

[0128] Example 10

[0129] The general procedure was the same as that of Example 1, except that the niobium oxide was Nb2O5 and Nb2O3, and the molar ratio of the two was 1:4.

[0130] Comparative Example 1

[0131] The general procedure was the same as that of Example 1, except that the niobium oxide in the raw material was Nb2O5.

[0132] Comparative Example 2

[0133] The general procedure was the same as that of Example 1, except that the niobium oxide in the raw material was Nb2O4 and Nb2O3, and the ratio of the two was 1:1 (molar ratio).

[0134] Performance Test

[0135] Test Item 1: Relative Density

[0136] Test Item 2: Conductivity

[0137] Test Item 3: Molar Percentage of +5 Valence Niobium in All Niobium Elements

[0138] The test results can be seen in Table 1.

[0139] Table 1 Test Results

[0140]

[0141] In summary, the features of the present case are as follows:

[0142] 1. As can be seen from Examples 1-3, Example 6, and Example 7, Example 6 does not have the mixing step of step 7 and adopts air debinding; Example 7 adopts air debinding; the niobium of Example 6 and Example 7 is almost completely oxidized, and the relative density of Example 6 is lower, indicating that if the mixing is not performed after granulation, it is harmful to the improvement of the relative density.

[0143] 2. By comparing Example 1, Example 9 and Example 10, it can be found that the pentavalent niobium content of Example 9 and Example 10 is relatively high, which is because the content of pentavalent niobium in the raw material is relatively high, and oxidation is inevitable in the whole process, whether it is Example 1 or Example 9, Example 10. One of the core tasks of the present application is to reduce oxidation.

[0144] 3. As can be seen from Comparative Example 1 and Comparative Example 2, the content of pentavalent niobium in the product will affect the relative density, which is a relatively difficult to explain phenomenon, and this phenomenon is also embodied in Example 6 and Example 7.

[0145] At the same time, from the above table, it can be concluded that when the content of pentavalent niobium is between 68% and 80%, the electrical conductivity will be greater than 200;

[0146] In other words, by controlling the content of pentavalent niobium in the product (through factors such as raw material blending, oxygen removal, oxygen-free sintering, etc.), the electrical conductivity of the product can be improved, and at the same time, it is beneficial to improve the relative density.

[0147] The examples presented herein are only selected from the combinations of all possible examples. The appended claims should not be limited by the embodiments of the present application. 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 tin-niobium oxide target, characterized in that, Tin oxide and niobium oxide are used as raw materials to prepare tin oxide and niobium oxide target materials; the specific method is as follows: Step 1: Mix niobium oxide and dispersant to form a slurry and grind it to obtain the first slurry; Step 2: Add tin oxide and dispersant to the first slurry, mix and grind to obtain the second slurry; Step 3: Add the binder to the second slurry, mix and grind to obtain the third slurry; Step 4: Spray granulation of the third slurry to obtain tin oxide-doped niobium oxide mixed powder; Step 5: Mix the tin oxide-doped niobium oxide mixed powder in a mixer under inert gas protection to obtain mixed powder; Step 6: Prepare the target preform using mixed powder; Step 7: Place the target blank into the sintering furnace for target blank sintering; The niobium oxide is a mixture of Nb₂O₅, Nb₂O₄, and Nb₂O₃; The molar ratio of Nb₂O₅, Nb₂O₄, and Nb₂O₃ is 1:1.5–3:3.5–5. The specific sintering operation is as follows: the target blank is placed in a sintering furnace for sintering. Under vacuum or inert gas protection conditions, the temperature is controlled at 400℃-600℃ at a heating rate of 0.1-0.5℃ / min and held for 6-12 hours. Then, the temperature is raised to 1100-1600℃ at a heating rate of 0.5-1.5℃ / min and held for 8-12 hours. The target material obtained by the preparation method contains 68%-80% pentavalent niobium.

2. The method for preparing the tin-niobium oxide target according to claim 1, characterized in that, The grinding times for steps 1, 2, and 3 are 3-8 hours, 3-8 hours, and 1-3 hours, respectively.

3. The method for preparing the tin-niobium oxide target according to claim 1, characterized in that, The dispersants used in steps 1 and 2 are all polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, or sodium hexadecylbenzenesulfonate. The adhesive used in step 3 is a mixture of polyvinyl alcohol and polyethylene glycol, polyvinyl alcohol, or polyvinyl butyral.

4. The method for preparing the tin-niobium oxide target according to claim 1, characterized in that, Step 5 specifically involves: Tin oxide-doped niobium oxide mixed powder is placed into a mixer for mixing. Nitrogen gas is introduced into the mixer during mixing at a flow rate of 0.1-0.3 L / min and a rotation speed of 30 rpm. The mixed powder is obtained after mixing for 30 minutes.

5. A tin-niobium oxide target material, characterized in that, It is prepared by the method described in any one of claims 1-4.

Images