High density ITO target and manufacture method thereof
Technical field
The present invention relates to the ITO target that a kind of sputter of transparent conductive film is used, particularly adopt indium trioxide (In
2O
3) or indium tin oxide (SnO
2-In
2O
3) indium target and the manufacture method thereof made for raw material.
Background technology
The ITO target generally adopts indium trioxide (In
2O
3) or indium tin oxide (SnO
2-In
2O
3) be raw material, ito thin film is owing to have two-fold advantage transparent and conduction, be one of numerous industry basic materials, therefore be widely used in fields such as solar cell, liquid-crystal display and plasma display, at the material that is absolutely necessary aspect LCD, frost prevention, antifog glass, the anti-infrared insulating surface.In recent years, be accompanied by the fast development of high-grade display device, the requirement of ito thin film also sharply increases.At present, the film coating method of industrial extensive employing is a magnetron sputtering method, and this method need use the ITO target as Coating Materials.
For the quality of target, require to have high-density and high homogeneity of ingredients.Highdensity target has conduction, good, the intensity advantages of higher of thermal conductivity, uses this target plated film, and the sputtering power that needs is less, and the rate of film build height is not easy to crack, the target long service life, and also the resistivity of the film that plates is lower, and transmittance is higher.The composition of target evenly is to the stable important assurance of plating film quality.
Because high-density is extremely important to the quality of target, so the producer of each target is exploring the method for production high-density target always.For example in application number is 97108322.3 Chinese invention patent, mention a kind of metal oxide target that is used for sputter coating, its raw material adopts indium, tin metal oxide composite end, the mass ratio of Indium sesquioxide and stannic oxide is 9: 1 in this composite powder, spherical in shape or the torispherical of powder, median size is 30-200nm, purity 99.99%, hard aggregation-free; Design specialized isostatic cool pressing jacket and hot isostatic pressing container, adopt isostatic cool pressing-hot isostatic pressing method to make column Indium sesquioxide/stannic oxide target, and cutting into the product of multi-disc desired size with wire cutting method, the relative density of this ITO sputtering target material product is 94-96%; In application number is 00136711.0 Chinese invention patent, a kind of sputter high-density tin indium oxide (ITO) target and manufacture method thereof that is used to make transparent conductive film, adopt hot pressing sintering method to carry out the manufacturing of target, it has higher density, and relative density is greater than 98%; Composition is even.It adopts indium metal and metallic tin is raw material, with chemical coprecipitation manufactured ITO powder, then with the ITO powder through hot-forming, the briquetting that obtains is made the ITO target behind processing grinding.This target can be used for making transparent conductive film.2000 the 4th phases of Chinese science and technology periodical " functional materials ", " indium tin oxide ceramic target hot isostatic pressing densification research " has been introduced with the chemical legal system that usually is total to and has been equipped with indium tin oxide (ITO) composite powder, and powder carries out the hot isostatic pressing densification behind cold isostatic compaction.Adopt carbon steel to make jacket during hot isostatic pressing, adopt the Copper Foil interlayer, experimental study the influence of heat and other static pressuring processes parameter-holding temperature, dwell pressure and soaking time to the densification of ITO ceramic target, think higher in the relative density of 1000 ℃ of left and right sides targets; In addition, the preparation that " Kunming University of Science and Technology's journal " 1997,22 (1) " application and the technology of preparing of indium tin oxide (ITO) target " introduced existing ITO target has wet powder-making and dry method powder process, and powder process is after hot pressing or static pressure, cast etc., and sintering obtains again; The academic dissertation of the retinue of Zhongnan Polytechnic Univ hundred straight hair tables has been studied chemical coprecipitation and has been prepared ITO target hot isostatic pressing densification process, and proposing to select the foundation of hot isostatic pressing densification process for use is to obtain DB in this way easily; External scientific and technical literature and United States Patent (USP), Japanese Patent, PCT patent also disclose the content of some preparation ITO targets, wherein also mention the employing ammonia precipitation process---and hydrothermal method, cold isostatic compaction method prepare the high density ITO target.
In present disclosed document, the weak point that the method for production high-density target exists is: hot isostatic apparatus costliness, running cost are higher, so the production cost of this method is higher; The large-size target of hot pressing sintering method manufacturing ftractures easily, and cost is still very high; The product dispersiveness that the method that has obtains is bad, and aggregation phenomenon easily takes place.
Technology contents
The inventor has analyzed the deficiencies in the prior art part through research and exploration, produces the ITO target of high-density, high purity, uniform ingredients with lower cost.
Technical scheme of the present invention is: use a kind of like this ITO powder for making the starting material of target, this powder has following feature: relative density is greater than 98.5%, composition is even, and powder is taked Hydrothermal Preparation, observes the median size≤100nm of powder under the scanning electron microscope; Under the condition that does not add dispersion agent, adopt the maximum particle diameter≤1.5 μ m of laser particle analyzer test.This high density ITO target manufacture method is: this monodispersed ITO nano-powder is put into the pressure pre-molding that stainless steel mould uses 10-100MPa, being inserted in rubber mold subsequently carried out under 300-700MPa pressure isostatic cool pressing 10-20 minute, after the release base substrate inserted sintering oven in air ambient 800-1600 ℃ following sintering 1-4 hour, the burning piece processing grinding that will obtain at last just can obtain the ITO target.
Advantage of the present invention and positively effect are:
1) employed ITO powder has performances such as single dispersion, nothing reunion;
2) technology that is adopted is simple, and process is controlled easily, makes large-size target easily, and the facility investment of use is less, and production cost is low;
3) target of manufacturing, the density height does not add any binding agent and dispersion agent in manufacturing processed, thereby has guaranteed the purity of target.
Further specify outstanding feature of the present invention below by example, only never limit the present invention, that is outstanding feature of the present invention and marked improvement never are limited to following example in explanation the present invention.
Embodiment of the present invention are as follows:
Embodiment 1, to get largest particle particle diameters that 1000 gram laser particle analyzers measure be that the ITO powder of 1.5 μ m Hydrothermal Preparation is packed in the stainless steel mould, mould is of a size of 100 * 100mm, under the pressure of 50MPa, carry out just molded, insert in the rubber mold subsequently, the isostatic cool pressing compacting is 10 minutes under 300MPa pressure, it is 51% that base substrate after the compacting is taked the relative density of Archimedes's test determines, with this base substrate 800 ℃ of following sintering 4 hours.The cooling back is taken out and is burnt piece, through processing and grinding, obtains being of a size of the target of 100 * 100 * 10mm, target material surface color even, flawless.The relative density that adopts Archimedes's test mode to measure is 99.2%.
Embodiment 2, to get largest particle particle diameters that 1000 gram laser particle analyzers measure be that the ITO powder of 1.5 μ m Hydrothermal Preparation is packed in the stainless steel mould, mould is of a size of 100 * 100mm, under the pressure of 50MPa, carry out just molded, insert in the rubber mold subsequently, the isostatic cool pressing compacting is 15 minutes under 500MPa pressure, it is 51% that base substrate after the compacting is taked the relative density of Archimedes's test determines, with this base substrate 900 ℃ of following sintering 2 hours.The cooling back is taken out and is burnt piece, through processing and grinding, obtains being of a size of the target of 100 * 100 * 10mm, target material surface color even, flawless.The relative density that adopts Archimedes's test mode to measure is 99.2%.
Embodiment 3, to get largest particle particle diameter that 100 kilograms of laser particle analyzers measure be that the ITO powder of 1.5 μ m Hydrothermal Preparation is packed in the stainless steel mould, mould is of a size of 500 * 500mm, under the pressure of 100MPa, carry out just molded, insert in the rubber mold subsequently, the isostatic cool pressing compacting is 20 minutes under 600MPa pressure, it is 48% that base substrate after the compacting is taked the relative density of Archimedes's test determines, with this base substrate 900 ℃ of following sintering 2 hours.The cooling back is taken out and is burnt piece, through processing and grinding, obtains being of a size of the target of 500 * 500 * 50mm, target material surface color even, flawless.The relative density that adopts Archimedes's test mode to measure is 98.8%.
Embodiment 4, to get largest particle particle diameter that 100 kilograms of laser particle analyzers measure be that the ITO powder of 1.5 μ m Hydrothermal Preparation is packed in the stainless steel mould, mould is of a size of 500 * 500mm, under the pressure of 100MPa, carry out just molded, insert in the rubber mold subsequently, the isostatic cool pressing compacting is 10 minutes under 700MPa pressure, it is 48% that base substrate after the compacting is taked the relative density of Archimedes's test determines, with this base substrate 1600 ℃ of following sintering 1 hour.The cooling back is taken out and is burnt piece, through processing and grinding, obtains being of a size of the target of 500 * 500 * 50mm, target material surface color even, flawless.The relative density that adopts Archimedes's test mode to measure is 98.8%.