A low-resistance, high-mobility indium oxide doped target material and a method for producing the same

Abstract

The application relates to the technical field of target production, and discloses a low-resistance and high-mobility indium oxide doped target material, wherein metal elements in the target material are composed of indium, titanium, holmium and cerium; the molar ratio of the indium, titanium, holmium and cerium is 92.4-95.2:3-4:0.7-0.9:1.5-1.8; the target material is prepared through a degreasing operation and an oxygen-rich sintering operation of a target precursor containing indium oxide powder, titanium oxide powder, holmium oxide powder and cerium oxide powder; the process parameters of the degreasing operation are as follows: a degreasing temperature is 500-600 DEG C, and an oxygen pressure is 0.02-0.05 MPa; and the process parameters of the oxygen-rich sintering operation are as follows: a sintering temperature is 1300-1550 DEG C, and an oxygen pressure is 0.09-0.12 MPa.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of target material production, and particularly relates to a low-resistance and high-mobility indium oxide doped target material and a preparation method thereof. BACKGROUND

[0002] The oxide target material is a kind of key film-coated substrate, which is mainly used for preparing TFT thin film by magnetron sputtering and is widely applied in the fields of solar cells, flat panels, liquid crystal displays, light emitting diodes and the like. Indium tin oxide (ITO) is the most widely used transparent conductive oxide, accounting for more than 90% of the international market share. However, the ITO thin film still has some defects to be solved, such as high cost due to the scarcity of In element, poor light transmittance in the near-infrared region, and large brittleness which is difficult to meet the requirements of modern optoelectronic devices for flexibility. With the development of science and technology and the updating of various electronic components, the performance of the ITO thin film can no longer meet the needs of application.

[0003] CN103274608A discloses a semiconductor thin film, a preparation method of the semiconductor thin film and a semiconductor element; an amorphous oxide thin film containing an amorphous oxide is exposed to an oxygen plasma generated by exciting an oxygen-containing gas with a high frequency. The generation conditions of the oxygen plasma are preferably that the applied frequency is 1 kHz or more and 300 MHz or less, and the pressure is 5 Pa or more. In addition, the amorphous oxide thin film is exposed by any one of a sputtering method, an ion plating method, a vacuum evaporation method, a sol-gel method and a particle coating method.

[0004] The above-mentioned amorphous oxide thin film is a thin film mainly containing indium oxide, which is crystallized by being exposed to the above-mentioned oxygen plasma.

[0005] The above-mentioned amorphous oxide thin film contains a divalent metal oxide; the above-mentioned divalent metal oxide is one or more metal oxides selected from at least any one of zinc oxide, magnesium oxide, nickel oxide, copper oxide and cobalt oxide.

[0006] The above-mentioned amorphous oxide thin film contains a trivalent metal oxide; the above-mentioned trivalent metal oxide is one or more metal oxides selected from at least any one of boron oxide, aluminum oxide, gallium oxide, scandium oxide, yttrium oxide, lanthanum oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide and lutetium oxide.

[0007] In the research, we used the oxides of divalent, trivalent, tetravalent and pentavalent metal elements for experiments, and found that not all oxides of metal elements can achieve ideal effects in terms of mobility and resistivity.

[0008] The problem to be solved by the present application is how to improve the mobility and reduce the resistivity of the indium oxide target. SUMMARY

[0009] The present application aims to provide a low-resistance and high-mobility indium oxide doped target, which is mainly composed of 92.4-95.2 mol% of indium and doped with trivalent and tetravalent metal oxides. Compared with other similar doped indium oxide targets, the resistivity of the target can be further reduced, and the mobility can be further improved.

[0010] Meanwhile, the present application also discloses a preparation method of the target.

[0011] To achieve the above-mentioned purpose, the present application discloses a low-resistance and high-mobility indium oxide doped target, wherein the metal elements in the target are composed of indium, titanium, holmium and cerium; and the molar ratio of the indium, titanium, holmium and cerium is 92.4-95.2:3-4:0.7-0.9:1.5-1.8.

[0012] The target is prepared by a target precursor containing indium oxide powder, titanium oxide powder, holmium oxide powder and cerium oxide powder through a degreasing operation and an oxygen-enriched sintering operation.

[0013] The process parameters of the degreasing operation are as follows: the degreasing temperature is 500-600 DEG C, and the oxygen pressure is 0.02-0.05 MPa.

[0014] The process parameters of the oxygen-enriched sintering operation are as follows: the sintering temperature is 1300-1550 DEG C, and the oxygen pressure is 0.09-0.12 MPa.

[0015] In the above-mentioned low-resistance and high-mobility indium oxide doped target, the molar ratio of the indium, titanium, holmium and cerium is 93.3-94.5:3.2-4:0.7-0.9:1.5-1.8.

[0016] In the above-mentioned low-resistance and high-mobility indium oxide doped target, the heating rate of the oxygen-enriched sintering is 0.3-2 / min, and the holding time is 4-12 h.

[0017] The process parameters of the degreasing operation are as follows: the holding time is 10-15 h, and the heating rate is 0.3-0.6 DEG C / min.

[0018] Meanwhile, the present application also discloses a preparation method of the above-mentioned indium oxide doped target, which specifically comprises the following steps: dispersing, grinding and drying indium oxide powder, titanium oxide powder, holmium oxide powder and cerium oxide powder in water to obtain a mixed powder; performing die pressing and cold isostatic pressing on the mixed powder to obtain a target precursor; and performing heating degreasing and oxygen-enriched sintering on the target precursor.

[0019] The process parameters of the debinding operation are: debinding temperature is 500-600 DEG C, oxygen pressure is 0.02-0.05 MPa;

[0020] The process parameters of the oxygen-rich sintering operation are: sintering temperature is 1300-1550 DEG C, oxygen pressure is 0.09-0.12 MPa.

[0021] In the preparation method of the indium oxide doped target material, the heating rate of the oxygen-rich sintering is 0.3-2 / min, and the holding time is 4-12h.

[0022] In the preparation method of the indium oxide doped target material, the process parameters of the debinding are: holding time is 10-15h, and the heating rate is 0.3-0.6 DEG C / min.

[0023] In the preparation method of the indium oxide doped target material, before debinding, the target precursor is placed in a sintering furnace and vacuumized, then oxygen is injected in the debinding operation, and after the debinding operation is completed, the oxygen pressure is increased for sintering operation.

[0024] In the preparation method of the indium oxide doped target material, the process parameters of the die pressing are: pressure is between 30-95 Mpa, and forming time is between 60-180s; the process parameters of the cold isostatic pressing are: pressure is between 200-500 Mpa, and forming time is between 60-180s.

[0025] The beneficial effects of the present application are:

[0026] The present application determines through experiments that the target material with 92.4-95.2 mol% of indium as the main metal has certain advantages in mobility, and by doping trivalent and tetravalent titanium, holmium and cerium, the particle size and crystal morphology can be optimized, which is part of the reason for the reduction of resistivity, and by optimizing the proportion of titanium, holmium and cerium, the resistivity can be further improved.

[0027] Meanwhile, the present application needs to cooperate with the oxygen-rich debinding and oxygen-rich sintering processes to obtain the required product, and the sintering gas pressure should be greater than the debinding gas pressure. DETAILED DESCRIPTION

[0028] In the description of the present application, it should be noted that the specific conditions are not indicated in the examples, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not indicated by the manufacturer, and are conventional products that can be purchased on the market.

[0029] The present application will be described clearly and completely below in connection with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] Embodiment 1

[0031] (1) A certain amount of indium oxide, titanium oxide, holmium oxide and cerium oxide powders were weighed according to the molar ratio of 93.3:4:0.9:1.8.

[0032] (2) Pure water, PVP, titanium oxide powder, holmium oxide powder and cerium oxide powder were sequentially added into a mixing barrel and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of titanium oxide powder, holmium oxide powder, cerium oxide powder, PVP and pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1300 r / min, the grinding time was 10 h, D50=0.468 μm, and slurry one was obtained.

[0033] (3) Pure water, PVP and indium oxide powder were sequentially added into the slurry obtained in step (2) and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of PVP, indium oxide powder and pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1300 r / min, the grinding time was 6 h, D50=0.389 μm, and slurry two was obtained.

[0034] (4) Binder PVA and PEG were sequentially added into the slurry obtained in step (3) and pre-dispersed for 30 min. The mass of PVA and PEG was 4% of the solid mass, and the solid mass accounted for 40% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1300 r / min, the grinding time was 5 h, D50=0.212 μm, and slurry three was obtained.

[0035] (5) The slurry three obtained in step (4) was pumped into a co-current spray drying tower for spray granulation, and the obtained powder was mixed and sieved by a mixer and a sieving machine.

[0036] (6) The prepared powder was sequentially subjected to die pressing and cold isostatic pressing to obtain a green body of the target material, wherein the pressure during die pressing of the target material was 90 MPa, and the pressure was maintained for 120 s; the pressure during cold isostatic pressing was 350 MPa, and the pressure was maintained for 120 s.

[0037] (7) Put the target blank into the sintering furnace, and vacuumize it first, then control the temperature to rise gradually, when the temperature reaches the debinding temperature, fill in oxygen, and keep the temperature under the oxygen pressure to debind. After debinding, increase the oxygen pressure, when the oxygen pressure reaches a certain value, increase the temperature to the sintering temperature at the same time, and keep the temperature to sinter. After sintering, decrease the temperature and stop the oxygen to obtain the sputtering target. In the process, the debinding temperature is 500°C, the oxygen pressure is 0.03 MPa, the keeping time is 10 h, and the temperature increasing rate is 0.3°C / min; the sintering temperature is 1400°C, the oxygen pressure is 0.11 MPa, the keeping time is 8 h, and the temperature decreasing rate is 1°C / min.

[0038] The relative density is 98.31%, the average crystal size is 8 μm, the resistivity is 0.981 mΩ.cm, and the mobility is 72 cm 2 / (V.s).

[0039] Example 2

[0040] (1) Weigh a certain amount of indium oxide, titanium oxide, holmium oxide and cerium oxide powders according to the molar ratio of 94.2:3.5:0.8:1.5.

[0041] (2) Add pure water, PVP, titanium oxide powder, holmium oxide powder and cerium oxide powder into the mixing barrel in sequence, and pre-disperse for 30 min. In the process, the mass of PVP accounts for 3% of the total mass of titanium oxide powder, holmium oxide powder, cerium oxide powder, PVP and pure water; the solid mass accounts for 50% of the total mass. Pump the pre-dispersed slurry into the sand mill, the grinding speed is 1350 r / min, the grinding time is 10 h, D50=0.423 μm, and slurry one is obtained.

[0042] (3) Add pure water, PVP and indium oxide powder into the slurry obtained in step (2) in sequence, and pre-disperse for 30 min. In the process, the mass of PVP accounts for 3% of the total mass of PVP, indium oxide powder and pure water; the solid mass accounts for 50% of the total mass. Pump the pre-dispersed slurry into the sand mill, the grinding speed is 1350 r / min, the grinding time is 6 h, D50=0.366 μm, and slurry two is obtained.

[0043] (4) Add the binder PVA and PEG into the slurry obtained in step (3) in sequence, and pre-disperse for 30 min. In the process, the mass of PVA and PEG is 4% of the solid mass, and the solid mass accounts for 40% of the total mass. Pump the pre-dispersed slurry into the sand mill, the grinding speed is 1350 r / min, the grinding time is 5 h, D50=0.195 μm, and slurry three is obtained.

[0044] (5) The slurry obtained in step (4) is pumped into a co-current spray drying tower for spray granulation, and then a mixer and a sifter are used to mix and sift the powder. The sifted powder is the powder of the prepared oxide target material.

[0045] (6) The prepared powder is sequentially cold-pressed and cold isostatic pressed to obtain a green compact of the target material, wherein the pressure during cold pressing of the target material is 90 MPa, and the pressure is maintained for 120 s; the pressure during cold isostatic pressing is 350 MPa, and the pressure is maintained for 120 s.

[0046] (7) The target blank is placed in a sintering furnace, vacuumed, and then gradually controlled to increase the temperature. When the temperature reaches the debinding temperature, oxygen is filled, and debinding is performed under the condition of oxygen pressure. After debinding, the oxygen pressure is increased, and when the oxygen pressure reaches a certain value, the temperature is gradually increased to the sintering temperature, and sintering is performed under the condition of maintaining the temperature. After sintering, the temperature is decreased and the oxygen supply is stopped to obtain a sputtering target material. The debinding temperature is 500°C, the oxygen pressure is 0.03 MPa, the temperature maintaining time is 10 h, the temperature increasing rate is 0.3°C / min; the sintering temperature is 1450°C, the oxygen pressure is 0.11 MPa, the temperature increasing rate is 0.5°C / min, the temperature maintaining time is 8 h, and the temperature decreasing rate is 1°C / min.

[0047] (8) After detection, the relative density of the sintered target material is 99.16%, the average crystal size is 3 μm, the resistivity is 0.856 mΩ.cm, and the mobility is 75 cm 2 / (V·s)

[0048] Example 3

[0049] (1) A certain amount of indium oxide, titanium oxide, holmium oxide, and cerium oxide powder is weighed according to the molar ratio of 94:3.6:0.8:1.6.

[0050] (2) Pure water, PVP, titanium oxide powder, holmium oxide powder, and cerium oxide powder are sequentially added to a mixing barrel, and pre-dispersed for 30 min. The mass of PVP accounts for 3% of the total mass of the titanium oxide powder, the holmium oxide powder, the cerium oxide powder, the PVP, and the pure water; the solid mass accounts for 50% of the total mass. The pre-dispersed slurry is pumped into a sand mill, the grinding speed is 1400 r / min, the grinding time is 10 h, D50=0.433 μm, and slurry one is obtained.

[0051] (3) Pure water, PVP, and indium oxide powder are sequentially added to the slurry obtained in step (2), and pre-dispersed for 30 min. The mass of PVP accounts for 3% of the total mass of the PVP, the indium oxide powder, and the pure water; the solid mass accounts for 50% of the total mass. The pre-dispersed slurry is pumped into a sand mill, the grinding speed is 1400 r / min, the grinding time is 6 h, D50=0.378 μm, and slurry two is obtained.

[0052] (4) To the slurry obtained in step (3), binder PVA and PEG were added in sequence, and pre-dispersed for 30 min. The mass of PVA and PEG was 4% of the solid mass, and the solid mass accounted for 40% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1400 r / min, the grinding time was 5 h, D50 = 0.201 μm, and slurry three was obtained.

[0053] (5) The slurry obtained in step (4) was pumped into a co-current spray drying tower for spray granulation, and then a mixer and a screening machine were used to mix and screen the powder. The screened powder was the powder of the prepared oxide target material.

[0054] (6) The prepared powder was sequentially subjected to cold pressing and cold isostatic pressing to obtain a green compact of the target material, wherein the pressure during cold pressing of the target material was 90 MPa, and the pressure was maintained for 120 s; the pressure during cold isostatic pressing was 350 MPa, and the pressure was maintained for 120 s.

[0055] (7) The prepared target blank was placed in a sintering furnace, vacuum was first applied, and then the temperature was gradually controlled. When the temperature reached the debinding temperature, oxygen was filled, and debinding was performed under the condition of oxygen pressure. After debinding, the oxygen pressure was increased, and when the oxygen pressure reached a certain value, the temperature was simultaneously gradually increased to the sintering temperature, and sintering was performed. After sintering, the temperature was decreased and the oxygen supply was stopped to obtain a sputtering target material. The debinding temperature was 550°C, the oxygen pressure was 0.05 MPa, the holding time was 10 h, the heating rate was 0.3°C / min; the sintering temperature was 1480°C, the oxygen pressure was 0.12 MPa, the heating rate was 0.5°C / min, the holding time was 8 h, and the cooling rate was 1°C / min.

[0056] The relative density was 99.32%, the average crystal size was 6 μm, the resistivity was 0.820 mΩ.cm, and the mobility was 78 cm 2 / (V.s).

[0057] Example 4

[0058] (1) A certain amount of indium oxide, titanium oxide, holmium oxide, and cerium oxide powder was weighed according to the molar ratio of 94.5:3.2:0.8:1.5.

[0059] (2) Pure water, PVP, titanium oxide powder, holmium oxide powder, and cerium oxide powder were sequentially added to a mixing barrel, and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of the titanium oxide powder, the holmium oxide powder, the cerium oxide powder, the PVP, and the pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 10 h, D50 = 0.471 μm, and slurry one was obtained.

[0060] (3) To the slurry obtained in step (2), pure water, PVP and indium oxide powder were added in sequence, and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of PVP, indium oxide powder and pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 6 h, D50=0.365 μm, and slurry two was obtained.

[0061] (4) To the slurry obtained in step (3), binder PVA and PEG were added in sequence, and pre-dispersed for 30 min. The mass of PVA and PEG each accounted for 4% of the solid mass, and the solid mass accounted for 40% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 5 h, D50=0.232 μm, and slurry three was obtained.

[0062] (5) The slurry obtained in step (4) was pumped into a co-current spray drying tower for spray granulation, and then a mixer and a screening machine were used to mix and screen the powder. The screened powder was the powder of the prepared oxide target material.

[0063] (6) The prepared powder was sequentially subjected to cold pressing and cold isostatic pressing to obtain a green compact of the target material, wherein the pressure during cold pressing of the target material was 90 MPa, and the pressure was maintained for 120 s; the pressure during cold isostatic pressing was 350 MPa, and the pressure was maintained for 120 s.

[0064] (7) The prepared target blank was placed in a sintering furnace, vacuum was first applied to the target blank, and then the temperature was gradually controlled to reach the degreasing temperature, oxygen was then filled, and degreasing was performed under the condition of oxygen pressure. After degreasing, the oxygen pressure was increased, and when the oxygen pressure reached a certain value, the temperature was simultaneously gradually increased to the sintering temperature, and sintering was performed under the condition of maintaining the temperature. After sintering, the temperature was decreased and the oxygen supply was stopped to obtain a sputtering target material. The degreasing temperature was 500°C, the oxygen pressure was 0.04 MPa, the holding time was 10 h, the temperature increasing rate was 0.3°C / min; the sintering temperature was 1450°C, the oxygen pressure was 0.08 MPa, the temperature increasing rate was 0.5°C / min, the holding time was 8 h, and the temperature decreasing rate was 1°C / min.

[0065] (8) The relative density was 99.08%, the average crystal size was 10 μm, the resistivity was 0.952 mΩ.cm, and the mobility was 65 cm 2 / (V.s).

[0066] Example 5

[0067] (1) A certain amount of indium oxide, titanium oxide, holmium oxide and cerium oxide powder was weighed according to the molar ratio of 94.2:3.4:0.7:1.7.

[0068] (2) Into a mixing tank, pure water, PVP, titanium oxide powder, holmium oxide powder, and cerium oxide powder are sequentially added and pre-dispersed for 30 minutes. The mass of PVP accounts for 3% of the total mass of titanium oxide powder, holmium oxide powder, cerium oxide powder, PVP, and pure water; the solid mass accounts for 50% of the total mass. The pre-dispersed slurry is pumped into a sand mill, the grinding speed is 1500 r / min, the grinding time is 10 hours, D50 = 0.462 μm, and slurry one is obtained.

[0069] (3) Into the slurry obtained in step (2), pure water, PVP, and indium oxide powder are sequentially added and pre-dispersed for 30 minutes. The mass of PVP accounts for 3% of the total mass of PVP, indium oxide powder, and pure water; the solid mass accounts for 50% of the total mass. The pre-dispersed slurry is pumped into a sand mill, the grinding speed is 1500 r / min, the grinding time is 6 hours, D50 = 0.349 μm, and slurry two is obtained.

[0070] (4) Into the slurry obtained in step (3), binder PVA and PEG are sequentially added and pre-dispersed for 30 minutes. The mass of PVA and PEG each accounts for 4% of the solid mass, and the solid mass accounts for 40% of the total mass. The pre-dispersed slurry is pumped into a sand mill, the grinding speed is 1500 r / min, the grinding time is 5 hours, D50 = 0.208 μm, and slurry three is obtained.

[0071] (5) The slurry obtained in step (4) is pumped into a co-current spray drying tower for spray granulation, and then a mixer and a screening machine are used to mix and screen the powder. The screened powder is the prepared oxide target material powder.

[0072] (6) The prepared powder is sequentially subjected to die pressing and cold isostatic pressing to obtain a green compact of the target material, wherein the pressure during cold pressing of the target material is 90 MPa, and the pressure is maintained for 120 seconds; the pressure during cold isostatic pressing is 350 MPa, and the pressure is maintained for 120 seconds.

[0073] (7) The prepared target blank is placed in a sintering furnace, vacuum is first applied to the target blank, and then the temperature is gradually controlled to rise. When the temperature reaches the degreasing temperature, oxygen is filled, and degreasing is performed under the condition of oxygen pressure. After degreasing, the oxygen pressure is increased, and when the oxygen pressure reaches a certain value, the temperature is simultaneously gradually increased to the sintering temperature, and sintering is performed. After sintering is completed, the temperature is decreased and oxygen supply is stopped to obtain a sputtering target material. The degreasing temperature is 500°C, the oxygen pressure is 0.03 MPa, the holding time is 10 hours, the temperature increasing rate is 0.3°C / min; the sintering temperature is 1450°C, the oxygen pressure is 0.07 MPa, the temperature increasing rate is 0.5°C / min, the holding time is 8 hours, and the temperature decreasing rate is 1°C / min.

[0074] (8) The relative density is 99.16%, the average crystal size is 12 μm, the resistivity is 0.985 mΩ.cm, and the mobility is 64 cm2 / (V.s). 2 / (V·s).

[0075] Comparative Example 1

[0076] (1) A certain amount of indium oxide powder, titanium oxide powder, holmium oxide powder, and cerium oxide powder were weighed according to a molar ratio of 95.2:2.1:0.9:1.8.

[0077] (2) Pure water, PVP, titanium oxide powder, holmium oxide powder, and cerium oxide powder were sequentially added into a mixing barrel, and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of titanium oxide powder, holmium oxide powder, cerium oxide powder, PVP, and pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 10 h, D50=0.463 μm, and slurry one was obtained.

[0078] (3) Pure water, PVP, and indium oxide powder were sequentially added into the slurry obtained in step (2), and pre-dispersed for 30 min. The mass of PVP accounted for 3% of the total mass of PVP, indium oxide powder, and pure water; the solid mass accounted for 50% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 6 h, D50=0.452 μm, and slurry two was obtained.

[0079] (4) Binder PVA and PEG were sequentially added into the slurry obtained in step (3), and pre-dispersed for 30 min. The mass of PVA and PEG each accounted for 4% of the solid mass, and the solid mass accounted for 40% of the total mass. The pre-dispersed slurry was pumped into a sand mill, the grinding speed was 1500 r / min, the grinding time was 5 h, D50=0.212 μm, and slurry three was obtained.

[0080] (5) The slurry three obtained in step (4) was pumped into a co-current spray drying tower for spray granulation, and the obtained powder was mixed and screened by a mixer and a screening machine.

[0081] (6) The prepared powder was sequentially subjected to die pressing and cold isostatic pressing to obtain a green body of the target material, wherein the pressure during die pressing of the target material was 90 MPa, and the pressure was maintained for 120 s; the pressure during cold isostatic pressing was 350 MPa, and the pressure was maintained for 120 s.

[0082] (7) The target blank is put into a sintering furnace, vacuumized, and then gradually heated. When the temperature reaches the debinding temperature, oxygen is filled in, and debinding is carried out under the condition of oxygen pressure. After debinding, the oxygen pressure is increased, and when the oxygen pressure reaches a certain value, the temperature is gradually increased to the sintering temperature, and sintering is carried out under the condition of holding. After sintering, the temperature is decreased and the oxygen supply is stopped to obtain the sputtering target. In this process, the debinding temperature is 500°C, the oxygen pressure is 0.03 MPa, the holding time is 10 h, and the heating rate is 0.3°C / min; the sintering temperature is 1400°C, the oxygen pressure is 0.11 MPa, the heating rate is 0.8°C / min, the holding time is 8 h, and the cooling rate is 1°C / min.

[0083] (8) The relative density of the target material is 98.19%, the average crystal size is 15 μm, the resistivity is 0.956 mΩ.cm, and the mobility is 52 cm 2 / (V.s)

[0084] Comparative Example 2

[0085] Compared with Example 1, the same molar ratio (93.3:4:0.9:1.8) of the components is used. The changed parameter is that the conventional muffle furnace sintering is used in the sintering process, and no vacuumization and oxygen supply are carried out. The detected relative density is 97.58%, the crystal size is 16 μm, the resistivity is 1.431 mΩ.cm, and the mobility is 45 cm 2 / (V.s).

[0086] Comparative Example 3

[0087] Compared with Example 2, the molar ratio (94.6:3.6:0:1.8) of the components of indium oxide, titanium oxide, holmium oxide, and cerium oxide powder is used, and other conditions are unchanged. The detected relative density is 98.82%, the average crystal size is 8 μm, the resistivity is 1.458 mΩ.cm, and the mobility is 35 cm 2 / (V.s).

[0088] Comparative Example 4

[0089] Compared with Example 3, the same molar ratio (94:3.6:0.8:1.6) of the components is used, and the changed parameter is that no oxygen is supplied during debinding, and the oxygen pressure during sintering is 0.12 MPa. Other conditions are unchanged. The detected relative density is 98.32%, the average crystal size is 12 μm, the resistivity is 1.125 mΩ.cm, and the mobility is 52 cm 2 / (V.s).

[0090] Comparative Example 5

[0091] Compared with Example 3, the molar ratio of indium oxide, titanium oxide, holmium oxide and cerium oxide powder components is (92.8:3.5:2.2:1.5), and other conditions remain unchanged. Through detection, the relative density is 98.96%, the average crystal size is 6 μm, the resistivity is 1.534 mΩ.cm, and the mobility is 46 cm 2 / (V.s).

[0092] Comparative Example 6

[0093] Compared with Example 4, the molar ratio of indium oxide, titanium oxide, holmium oxide and cerium oxide powder components is (94.6:2.2:2.8:0.8), and the changed parameter is that the conventional muffle furnace sintering is used in the sintering process, and the oxygen is not vacuumed and introduced. Other conditions remain unchanged. Through detection, the relative density is 97.84%, the average crystal size is 15 μm, the resistivity is 1.337 mΩ.cm, and the mobility is 41 cm 2 / (V.s).

[0094] Comparative Example 7

[0095] Compared with Example 4, the same components 94.5:3.2:0.8:1.5 are used, and the difference is the debinding and sintering temperature and the oxygen pressure. Other conditions remain unchanged. Through detection, the relative density is 99.36%, the average crystal size is 13 μm, the resistivity is 1.534 mΩ.cm, and the mobility is 54 cm 2 / (V.s).

[0096] The debinding temperature is 450°C, the oxygen pressure is 0.07 MPa, the holding time is 10 h, and the heating rate is 0.5°C / min; the sintering temperature is 1520°C, the oxygen pressure is 0.15 MPa, the heating rate is 1°C / min, the holding time is 8 h, and the cooling rate is 1°C / min.

[0097] Comparative Example 8

[0098] Compared with Example 5, the same molar ratio of components (94.2:3.4:0.7:1.7) is used, and the difference is the debinding and sintering temperature. Through detection, the relative density is 98.52%, the average crystal size is 15 μm, the resistivity is 1.182 mΩ.cm, and the mobility is 58 cm 2 / (V.s);

[0099] The debinding temperature is 400°C, the holding time is 10 h, and the heating rate is 0.5°C / min; the sintering temperature is 1350°C, the oxygen pressure is 0.07 MPa, the heating rate is 0.8°C / min, the holding time is 8 h, and the cooling rate is 1°C / min.

[0100] Comparative Example 9

[0101] Compared with Example 2, the molar ratio of indium oxide, titanium oxide, holmium oxide and cerium oxide powder components (94.2:5:0.8:0) was used, and other conditions were unchanged. The relative density was 98.82%, the average crystal size was 16 μm, the resistivity was 1.482 mΩ.cm, and the mobility was 38 cm 2 / (V-s).

[0102] Comparative Example 10

[0103] Compared with Example 2, the molar ratio of indium oxide, titanium oxide, holmium oxide and cerium oxide powder components (94.2:0:0.8:5) was used, and other conditions were unchanged. The relative density was 98.68%, the average crystal size was 12 μm, the resistivity was 1.259 mΩ.cm, and the mobility was 44 cm 2 / (V-s).

[0104] Comparative Example 11

[0105] Compared with Example 2, the molar ratio of indium oxide, titanium oxide, holmium oxide and cerium oxide powder components (94.2:3.5:0.8:1.5) was used, and other conditions were unchanged. The relative density was 98.25%, the average crystal size was 16 μm, the resistivity was 2.327 mΩ.cm, and the mobility was 32 cm 2 / (V-s).

[0106] The experimental data of the above examples and comparative examples are shown in Table 1 below:

[0107] Table 1 Test Results

[0108]

[0109]

[0110] Result Analysis:

[0111] 1. From the comparison of Examples 1-5 and Comparative Example 1, it can be found that the particle size of Comparative Example 1 is obviously increased, and the mobility is obviously decreased. It can be concluded that the use of titanium should not be too large; the possible reason is that titanium oxide is a semiconductor material with a high melting point and good thermal stability. The main role of titanium oxide in the target material is to improve uniformity, but too much titanium oxide will cause the conductivity of the target material to deteriorate and the mobility to decrease.

[0112] 2. By comparing example 1 and comparative example 2, it can be seen that the particle size, resistivity and mobility are all deteriorated, which shows that the pressure oxygen sintering is a very important control factor, and the possible reason for the influence of the calcination in the pressure oxygen atmosphere on the performance is that the sintering of the target in the pressure oxygen atmosphere makes the sintering of the target more sufficient, improves the density and obtains better grain size, so that the performance of the target is better.

[0113] 3. By comparing example 2 and comparative example 3, it can be seen that holmium is an essential element in the formula, and when it is missing, the resistivity is obviously reduced and the mobility is obviously deteriorated.

[0114] 4. By comparing example 3 and comparative example 4, it can be seen that the use of air atmosphere for debinding will lead to a larger particle size and higher resistivity, and the possible reason is that the organic additives added in the preparation of the target cannot be fully removed in the air atmosphere, and will carbonize at a too high temperature in the sintering process, resulting in a larger crystal particle size and higher resistivity.

[0115] 5. By comparing example 3 and comparative example 5, it can be seen that although holmium is an essential element in the formula, when its amount is excessive, it will seriously deteriorate the resistivity.

[0116] It can be seen from comparative example 3 that holmium does not affect the particle size, but has a decisive influence on the resistivity and mobility.

[0117] 6. By comparing example 4 and comparative example 6, it can be seen that when cerium is reduced, holmium is increased, and air sintering is used, the particle size, resistivity and mobility are all reduced, which can further show that air sintering is not conducive to the particle size, and holmium and cerium determine the resistivity and mobility, and from another angle, the process and formula selection of the present case are closely related and combined.

[0118] 7. By comparing example 4 and comparative examples 7 and 8, it can be seen that even if pressure oxygen debinding and sintering operations are used, the debinding temperature cannot be too low, and the oxygen pressure cannot be too large or too small, otherwise it will have adverse effects on the particle size, resistivity and mobility.

[0119] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and all are included in the protection scope of the present application.

Claims

1. A low resistance, high mobility indium oxide doped target material, characterized in that, The metal elements in the target material are composed of indium, titanium, holmium and cerium; the molar ratio of the indium, titanium, holmium and cerium is 93.3-94.5:3.2-4:0.7-0.9:1.5-1.8; The preparation method of the target material is specifically as follows: the indium oxide powder, titanium oxide powder, holmium oxide powder and cerium oxide powder are dispersed, ground and dried in water to obtain a mixed powder; the mixed powder is subjected to die pressing and cold isostatic pressing to obtain a target precursor, and the target precursor is subjected to heating degreasing and oxygen-enriched sintering. The process parameters of the degreasing operation are as follows: the degreasing temperature is 500-600 ℃, the oxygen pressure is 0.02-0.05 MPa, the holding time is 10-15 h, and the heating rate is 0.3-0.6 ℃ / min; The process parameters of the oxygen-enriched sintering operation are as follows: the sintering temperature is 1300-1550 ℃, the oxygen pressure is 0.09-0.12 MPa; the heating rate of the oxygen-enriched sintering is 0.3-2 ℃ / min, and the holding time is 4-12 h.

2. The method of claim 1, wherein the method further comprises: Before degreasing, the target precursor is placed in a sintering furnace and vacuumized, and then oxygen is injected in the degreasing operation; after the degreasing operation is completed, the oxygen pressure is increased for sintering operation.

3. The method of claim 1, wherein the target is an indium oxide doped target. The process parameters of the die pressing are as follows: the pressure is 30-95 MPa, and the forming time is 60-180 s; the process parameters of the cold isostatic pressing are as follows: the pressure is 200-500 MPa, and the forming time is 60-180 s.

Images