TW538121B - Solution method for preparing ITO powders - Google Patents

Abstract

A solution method for preparing indium-tin oxide (ITO) powders is provided. Different metal compounds are dissolved in water and proper additives respectively to form two solution bodies. Mixing the two solution bodies to form a mixing solution body and then adding some proper additives into the mixing solution bodies to form metal hydroxyl compounds with determined composition. After water washing and filtration, proper additives are added into the solution to peptize the solution. During the peptization process, hydrolysis and condensation reactions occurs between different metal hydroxyl compounds. Solvent of the solution is then removed to form high quality nanometer grade ITO powders.

Description

538121 _Case No. 90123049_Year Month Date _ «; _ V. Description of the Invention (1) The present invention relates to a method for preparing an indium tin oxide powder (hereinafter referred to as I TO) by an aqueous solution method, in particular, it refers to a method using The material is processed into high-quality nano meter (10-9) ITO powder. Because I TO powder is the raw material for making I TO sputtering targets, if you want to obtain high-quality, high-density IT0 sputtering targets, you need to form a uniform nanometer IT0 powder. Indium tin oxide (ITOUndium Tin Oxide) is a kind of indium oxide doped with tin, generally called indium tin oxide, which belongs to the η-type semiconductor. Because tin, which has one more valence electron than indium, is doped into the original indium oxide, The electron concentration of the free carrier is increased, and its conductivity is improved. The thin film made of I TO has high conductivity, high transmittance to visible light, and high reflectivity to infrared light, so it is widely used in transparent electrodes for solar cells, driving devices for flat-panel displays, and light detectors. , Transparent heating element, antistatic film 'electromagnetic wave protective film and other electronic, optical and optoelectronic devices, especially the transparent conductive electrode material of liquid crystal display (LCD). I TO film can be produced by vacuum evaporation method, magnetron sputtering method, chemical vapor deposition method, and immersion coating method. Among them, the sputtering method is more suitable for large-area substrates, and the process temperature is low, saving energy, without generating harmful substances, and has environmental advantages. Therefore, the sputtering method is often used in the production of I TO films. The sputtering method mainly uses high-energy ions to strike a suitable target, knocks out the target material, sputters it onto the target substrate, and deposits the required material on the substrate, and the deposited material is closely related to the target composition. That is to say, it is related to the purity, composition and mean squareness, density, and particle size distribution of the microstructure of leather materials. Generally, the sputtering target is made by a mixed oxide method.

538121 _Case No. 9Q123049_ 年月 日 _Character ___ V. Description of the invention (2) Mechanically mix different oxide raw material powders, and then use the hot (equal) or cold (equal) pressure solid state reaction method to make Targets with mixed oxides. The traditional solid state reaction method is to mix the powder of indium oxide and tin oxide by mechanical methods (such as ball milling), dry it and then calcinate to obtain I TO powder. There is a limit to the uniformity of the mixing of different oxides in the target, because the oxide may contain impurities, as well as the composition and particle size distribution of the raw material, which further affects the conductivity, light transmission and adhesion to the substrate of the I TO film. Sex. Another method that can be used to make ultra-fine powders for targets is the aqueous solution method. In order to dissolve the metal compounds to be mixed with water, and after appropriate treatment, the dissolved metal compounds are polymerized into a stable suspension in water with high Particles of molecular weight form a suspension solution, and finally all solvents are removed by heating and drying to obtain ultrafine particles for use in making sputtering targets. The conventional solid state reaction method has the disadvantage of imprecise production. The inventors also found that the finished product obtained by the aqueous solution method also has the disadvantage of impreciseness, especially the conventional aqueous solution method does not have a degumming process, and the particle size of the finished product is obtained. Larger and more uneven composition, in order to meet the actual needs, the inventor has carried out research and development to solve the problem of precision production that cannot be achieved by conventional methods. The purpose of the present invention is to provide a method for preparing an indium tin oxide powder by an aqueous solution method, and provide a method for manufacturing a sputtering target by using the obtained product. The raw materials obtained by different manufacturing methods, using an aqueous solution process (Solution Process), will be appropriate. Solvent and additives to dissolve different metal compounds respectively, and prepare a second clear solution, and then stir the two solutions to mix the two solutions uniformly to make a homogeneous aqueous solution, so that the specific components in different compounds undergo a condensation reaction. Special solution after adding lye

538121 Case No. 90123049 _η Revision V. Explanation of the invention (3) Glue procedure to make it suspend fine hydrogen hydroxide powder, and use homogeneous sputtering for life, and mention the above-mentioned reuse level due to the chemical method, so the light transmission temperature It can be changed, the purpose and the advantages are matched with the invention powder using a sputtered film to trigger the manufacturing property, Λ- / Γ, that is to avoid the need to make the match, when the hair system is stable, the first type is Zhongyi , Made by the agglomeration of a water-soluble target material and the energy-saving material is expensive. The gold can be formed into a stable suspension with appropriate molecular weight, uniform composition, and small particle size particles. The obtained pressure equalizing forming and sintering treatment can be used to produce a better chemically homogenized bar material, and the handle material can be used to increase the characteristics of the thin film produced after sputtering using the I bar material. According to the stable suspension solution prepared according to the present invention, the solvent can be removed by heating and drying procedures, etc., and then the nano-pressure equalizing molding and sintering treatment can be obtained to produce a sputtering target. The liquid method is used to make sputtering targets for IT 0 thin films. The particle size and composition uniformity of the constituent particles affect the electrical and optical properties of indium tin oxide, while the aqueous solution process uses a solution reaction to generate molecular-level materials. The target with uniform composition, the target for sputtering can improve the conductivity of the sputtered thin film, and because the composition particles are small, the source consumption required for sintering is further reduced. In addition, the target with a small particle size in the microstructure shrinks during sputtering and strengthens the phenomenon of overheating with cooling water, so it can increase the life of the target. The reviewing committee can further understand the present invention in order to achieve the predetermined technology, means and effects, and hereby give a better and feasible implementation. The detailed description is as follows. A method for preparing an indium tin oxide powder by an aqueous solution method. A floating solution method uses an inorganic salt as a starting material. The inorganic salt can be divided into three types according to the method of obtaining: It is obtained by dissolving in an acid solution. Inorganic salts; second

538121 Case No. 90123049 λ_a. Amendment V. Description of the invention (4) The recovered waste is a common commercial inorganic salt that will react with water in the water to produce the wrong and nucleophilic addition of two suspended particles. In the molecular suspended particles, Add a stable suspension as shown in the first picture as indium tin oxide powder a. Dissolution: It is also possible to separate the amount of acid solution indium and tin into concentrated acid solution. b. Mixing: c. Shen Dian: plus adjusted ammonium oxide produced by solution d. filtration, water filtration), inorganic salts obtained by dissolving the target in acid solution; third inorganic salts sold on the market . In the preparation of aqueous solutions that are starting materials, inorganic metal salts undergo hydrolysis and condensation reactions, in which metal cations are first reacted with ions, followed by hydrolysis reactions, and then subjected to nucleophilic substitution condensation reactions to produce M ′ -0-M bonds. After adding an appropriate amount of test solution to the bound inorganic polymer, the M '-0-M-bonded inorganic layer is converted into M (OΗ) and M' (ΗΗ) hydroxide suspended particulates in an amount of acid to suppress hydroxide. Coalescence occurs to form fluid. The flow chart shown is a method for preparing the end by an aqueous solution method according to the present invention. According to the flow chart, the description is as follows: Equivalent indium compounds and tin compounds are separately dissolved in water. Metal indium and metal tin, or recovered waste target materials are dissolved in appropriate, and then dissolved in water, so that the concentration of the son contained in the aqueous solution is about 0.1 Μ-5. 0 Μ, as the dissolved acid solution can be concentrated, concentrated Hydrochloric acid or concentrated nitric acid and concentrated hydrochloric acid in an appropriate ratio are mixed with the above two solutions and mixed thoroughly, and stirred; Add an appropriate amount of lye to adjust the appropriate pH value to make the original clarification and precipitation, where the concentration of the lye is IN-1 2N, and the pH range is 3-9; the lye can be ammonia or alkyl-containing hydrogen Compound (such as 1-methylammonium hydroxide) ◦ Wash: The above solution is filtered by appropriate means (such as decompression and re-scattering the filter cake with pure water, repeat this action again

538121 _ Case No. 90123049_ Year Month Amendment _ V. Description of the invention (5) and above. A suspension after washing with water is formed. e. Degumming: Add the appropriate amount of acid solution to the suspension after washing with water to control the pH of the solution to a proper range and stir for a suitable time to degumming. The concentration of the acid solution is 1 N-1 5 N, the adjustment range of the pΗ value is 1-6, and the stirring time is 2-7 2 hours; the acid solution may be nitric acid, hydrochloric acid, acetic acid, oxalic acid, or formic acid. f · Drying: The suspension after the above degumming is dried to obtain a white powder of Indium Tin Hydroxide (hereinafter referred to as ITH). The method for drying the indium tin oxide powder may be directly drying in an oven or using Spray dryer to dry. g. Burning: Put the white I TH powder into a high temperature furnace, and burn it to yellow-green I TO powder after proper heating rate, holding temperature and holding time. The heating rate is 1-20 ° C per minute, the holding temperature is 300-1 100 ° C, and the holding time is 0.5-5 hours. Example 1 (commercially sold inorganic salts) a. Take 5 0. 05 g of indium nitrate (containing a crystal water, purity 99.99%, molecular weight 3 18.8. 5) and 5.6 7 g of tin chloride (containing five crystal waters, with a purity of 99% and a molecular weight of 35.50) were separately dissolved in deionized water, and the final volumes of the solutions were 15 5 m L and 16 m L, at this time the marriage and tin ion concentration were 1.0 M. b. Mix the two clear solutions thoroughly and stir them. In this case, the mole ratio of indium tin ions is 9 0: 10. c. In the state of searching and mixing, quickly add 35 ml of concentrated ammonia water (25 wt%) to make the originally clear solution produce a white precipitate. At this time, the pH value is 7.25.

538121

C. The above white precipitate-containing solution is continuously stirred for at least 12 hours. d. The above solution was filtered under reduced pressure to obtain water, and a white cake was obtained, which was placed in deionized water and stirred again to break up the filter cake. This operation was repeated twice. After the last filtration, deionized water was added so that the volume of the valley solution was about 180 mL to obtain a suspension. e. Add 3 mL of concentrated nitric acid (70 wt%) 'to the suspension after washing and filtering with water to make the pH of the solution 3 · 5 8 and stir for 24 hours. e 1 · The above solution was measured by a particle size analyzer, and its particle size was 5 3 nm. f. The above-mentioned degummed suspension was spray-dried to obtain 32.61 g of white indium tin hydroxide (hereinafter referred to as ITH) powder. As a result of TG analysis, the 10ss rate was 28.1%. g. Put the white ITH powder into a high-temperature furnace and hold the temperature at 800 ° C for 3 hours at a temperature rise rate of 10 ° C / min to obtain a yellow-green I τ 0 powder. Example 2 (commercially sold metal made of inorganic salts) a • Take 2 5 · 0 2 g of metal indium (purity: 99.99%, molecular weight: 11 4 · 8), dissolved in 100mL of concentrated stone Acid (70wt%), add an appropriate amount of deionized water, so that the final volume of the solution is 2 1 8 ml, and the indium ion concentration at this time is 1.0M. Take 7 · 94 g of tin chloride (containing five crystal waters, purity 99%, molecular weight 3 50 · 50) and dissolve it in deionized water to make the final volume of the solution 22 mL. The ion concentrations were each 1 M. b. Mix the two clear solutions thoroughly and mix them. The molar ratio of indium tin ions at this time is 90:10.

Page 10 538121 90123049

Case number five, description of the invention (7) Ϊ f, I i quickly add 75 rnL of the product, the product c · Stir to make the original clear 11 〇 • The above content is included ° The above filter cake, the action is repeated to make the solution After water (70 wt ° / 〇), the above solution is called ITH, which is the solution to the white, and it is thermally divided into 25.54%.

C dee I ο clear solution produces a white sinking substance 'ammonia water (25 wt%),' p Η value at this time is 7. At least 12 hours, the solution is filtered under reduced pressure and placed in deionized water to re- ^ Shangzhi 'can get white three times. At the last pass = break the filter 'cake, so the volume is about 240 ffiL to get y4' plus. Into deionized water, wash the filtered yarrow, 1 / liquid. You decide, y Γ adds the concentrated nitric acid of 5 company, Hiroyuki pΗ becomes 3. 4 2 and stir for 2 4 hours. As measured by liquid particle analyzer, its particle size is 42. The gelled suspension was spray-dried to obtain hydrogen emulsified Indium Tin Hydroxide (43.18 g of powder below. As a result of TG analysis, the solution with a loss rate of white precipitate continued to stir Drop S '· Put the white ITH powder into a high-temperature furnace, and hold it at 800 ° C for 3 hours at a heating rate of 10 ° C / min to obtain a yellow-green I TO powder. The metal is dissolved into an inorganic salt with an acid) (the conventional control is implemented) a. Take 2 5 · 11 g of metal indium (purity: 99.99%, molecular weight: 1 1 4 · 8), and dissolve in 100mL of concentrated nitric acid ( 70wt%), add an appropriate amount of deionized water, so that the final volume of the solution is 2 1 8 m L 'At this time the indium ion concentration is 1.0 M. Take 7. 9 6 g of tin chloride (containing five Crystal water, purity 99%

Page 11 538121 _Case No. 9Q123049_Year Month Day__ V. Description of the invention (8), molecular weight is 3 50.50) Dissolved in deionized water, and the final volume of the solution is 22mL, so that indium, tin The ion concentrations were each 1M. b. Mix the two clear solutions thoroughly and stir them. The molar ratio of indium tin ions at this time is 90:10. c · With stirring, quickly add 100mL of concentrated ammonia (25wt%) to make the originally clear solution produce a white precipitate. At this time, the pH value is 7 · 16 ° c 1 · The above solution containing white sinks Continuous teaching: Mix for at least 12 hours. d. Filter the water in the above solution under reduced pressure to obtain a white filter cake. Then place it in deionized water and stir again to break up the filter cake. Repeat this operation three times. After the last filtration, deionized water was added to make the solution volume about 240 mL to obtain a suspension. e. Stir the above-mentioned suspension after washing and filtering with water, without adding any acid, for 24 hours. e 1 · The above solution was measured by a particle size analyzer, and its particle size was 2 350 nm. f. The above-mentioned degummed suspension was spray-dried to obtain a white powder of Indium Tin Hydroxide (hereinafter referred to as ITH) totaling 43.18g. As a result of TG analysis, the loss rate was 2 5. 5 4〇 / 〇 〇

g. Put the white ITH powder into a high-temperature furnace, and hold it at 800 ° C for 3 hours at a temperature rising rate of 10 ° C / min to obtain a yellow-green I TO powder. Example 4 (I T 0 waste target recovered and reused)

Page 12 538121 _ Case No. 90123049__ 年月 日 # 正 _ V. Description of the invention ⑼ a · Take 10.03g of ITO waste and dry material and dissolve it in concentrated hydrochloric acid (37wt%) in iQQmL. After dissolution, filter To remove undissolved impurities. The solution was quantified by an inductively coupled plasma-atomic emission spectrometer (ICP-AES) with inductively bound ions and atoms, and the indium / tin ratio was 15. An appropriate amount of deionized water was added to make the final volume of the solution 15 OmL. a 1 · Take 6. · 10 g of gasified tin (containing five crystal waters, purity 99%, molecular weight 350.50) and dissolve in 25 mL deionized water. b. Mix the two clear solutions thoroughly and stir them. At this time, the molar ratio of indium tin ions is 90:10. c · With stirring, quickly add 150 mL of concentrated ammonia (25wt%) to make the originally clear solution produce a white sink, at this time the p Η value is 7. 30 〇c 1 The solution was continuously stirred for at least 12 hours. d. Filter the water in the above solution under reduced pressure to obtain a white filter cake. Then place it in deionized water and stir again to break up the filter cake. Repeat this operation three times. After the last pass, deionized water was added so that the volume of the valley solution was about 175 m L to obtain a suspension. e. Add 5 mL of concentrated nitric acid (70 wt%) to the suspension after washing and filtering to make the solution pH 3.50, and stir for 24 hours. e 1 · The above solution was measured by a particle size analyzer, and its particle size was 2 7ηη. ί · The above-mentioned degummed suspension was spray-dried to obtain a white indium tin hydroxide.

Page 13 538121 Case No. 90123049 Amendment V. Description of Invention (10) hereinafter referred to as ITH) powder 9.64g. As a result of TG analysis, the loss rate was 25.15%.

g. Put the white ITH powder into a high-temperature furnace, hold the temperature at 10 ° C / min for 3 hours, and obtain yellow-green I TO powder. Example 5 (Example made by the present invention) (1) · Take 50 g of IT 0 powder prepared by the method of the above Example 2, put it into a 1 L ball mill pot, add 50 g of water, and prepare a solid content It was a 50 wt% slurry and was ball milled for 24 hours. (2) • The above slurry is dried to obtain a ball milled I TO powder. (3) • The powder was placed in a 1.6-inch mold, and cold-pressed and cold-pressed, respectively, to obtain a target blank of I TO. (4) • The above target green body is placed in a high-temperature sintering furnace, and the sintering conditions are as follows: Step 1 Step 2 Step 3 Step 4

(step 1) Increase the temperature from room temperature to 8 0 ~ 1 2 0 at a temperature increase rate of 1 ~ 1 5 ° C / min (Γ C; (Step 2) Change the temperature from 800 ~ 5 at a temperature increase rate of 0.5 ~ 15 ° C / min 12 0 0 ° C rises to 14 0 0 ~ 1 6 0 0 ° C, holding temperature for 3 ~ 5 4 hours, at this time, 0.6 ~ 1.5atm of oxygen is introduced; (step 3) with 0.5 · 15 ~ 15 ° The cooling rate of C / min is reduced from 1400 to 16 0 ° C to 8 0 to 1 2 0 0 ° C. At this time, the oxygen of 0.6 to 1.5 atm is still maintained; (step 4) The furnace is changed from 8 0 to 0 1 2 0 0 ° C natural cooling to room temperature. • 1.3 inches of I TO target material can be obtained through the above steps, after Archi

Page 14 538121 Thank you 23__I month day repair 1 (11) The result of Mead method measurement, the target density is 96%. (Comparative example prepared by conventional methods) 45 g of commercial indium oxide powder and 5 g of tin oxide powder were respectively placed in a 1 L ball mill tank, and 50 g of water was added to prepare a slurry with a solid content of 50 wt%, and ball milled. 24 hours. Saki The above slurry was dried to obtain a ball milled I τ〇 powder. The powder was placed in a 1.6-inch mold, and cold-pressed and cold-pressed, respectively, to obtain the target material of I TO. The target material was placed in a high-temperature sintering furnace, and the sintering conditions were as follows: 1) The temperature was raised from room temperature to 8 0 to 1 2 0 at a temperature increase rate of 1 to 15 ° c / m i η. . ^ 2) The temperature is raised from 800 ~ 1 2 0 0 ° C to 14 0 0 ~ 1 6 0 0 ° C at a heating rate of 0.5 ~ 15c / niin, and the holding temperature is 3 ~ 54 hours. Pass in 0.6 to 1.5 a tm of oxygen; Step 2 (step 3) is 0.5 to 15. (: The temperature reduction rate of / 111 丨 11 is reduced from 14000 ~ 1600 ° C to 80-10-1200 ° C, and at this time, the oxygen of 0.6 ~ 1.5atm is still maintained; 4) Make the furnace from 8 0 0 ~ 1 2 0 0 t Cool naturally to room temperature. The above target green body was sintered to obtain a 1.3-inch I TO target. As a result of the ~ Kimid method, the target density was 95%. Description of the invention

2 (4) · Step 1 (step 2). The results are compared. The target materials obtained in Example 5 and Example 6 are probed electronically, and the microprobe analysis of EPMA (electron probe) is performed.

Page 15 538121 _Case No. 90123049_Year Month and Day__ V. Explanation of the invention (12) microanalysis), observe the distribution of indium and tin, the second and third figures are the fifth and sixth targets of Example 5 In the EPMA diagram of the material, the white dots are the distribution of tin oxide. It can be found that the tin oxide distribution of the target prepared by the powder prepared in Example 2 of the present invention is better than the target prepared by the traditional solid state method. In summary of the processing procedures described above, the present invention mainly uses stirring to promote the homogenization of the solution, and then uses the control mode of the degumming process to suppress the phenomenon of hydroxide coalescence. In the process of the invention and the conventional process, the particle size obtained is 14 2 2 35 0 nm, and the gap is 16. 5 times. From this, it can be known that the fineness of the present invention is based on the first and second embodiments. The fourth and the fourth prove that the three kinds of raw materials that can be used in the present invention can all achieve the purpose of the invention. After further manufacturing the finished product in the foregoing embodiments five and six, the comparison results also confirm that the present invention has a higher quality than the conventional one. Density; Therefore, the process of the present invention has practicability, which can produce a progressive effect different from the conventional one, and can provide good usability. Therefore, the present invention is novel and original, and complete and conventional Different methods apply for patent protection according to law. The above are detailed descriptions and drawings of the preferred embodiments of the present invention, and are not intended to limit the present invention. All the scope of the present invention shall be subject to the following patent scope. Any embodiment of the spirit of the patent scope and its similar changes And similar structures should be included in the present invention.

Page 16 538121 Case No. 90123049 Amendment Brief Description of the Drawings The first figure is the flow chart of the aqueous solution manufacturing process of the present invention. The second figure is an EP MPA diagram of the fifth embodiment of the present invention. The third diagram is an EP M A diagram of Embodiment 6 of the present invention.

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Claims (1)

538121 Case No. 90123049 Revised to make indium, indium, gold, indium, indium and indium based nitration and nitrification. Condensation of alkane through oxygen concentration of oxygen to indium oxygen Oxygen is used as an acid or as an acid. It is made or made of acid, made of nitrate, made of tin, made of water, made of salt, made of material, made of law, method of ammonia, concentrated solution of liquid, liquid, and liquid chlorine. The solution is waste or dissolved, and dissolved into water. Water, water-shaped liquids are described in terms of nitrate, acid, and the eulogy of thick substances in the form of alkali. It is described as the synthesizing the sudden liquid, the liquid, the liquid, and the liquid, and the acid, the acid, the acid, the indium, the acid, and the tin, C. 1 in acid 4 in 4 in 1 in. Dissolve other liquids first than other materials. Enclose, enclose, dissolve encircle, encircle, encircle, target, target, method, mixed, method, method, method, method, method, method, method, method, method, method, method Specialize in the special environmen, please do n’t be thick, please do n’t ask for the last__After the material, apply for powder, apply for powder, apply for powder, apply for powder, apply powder for hydrogen * # target use, such as stannic acid, such as tin Tin as Tin as Tin by ... 6 3 4 5 6 7 Indium Oxide Indium. Hydrogenation, oxidization, hydrogenation, oxygenation, oxygenation, oxygenation, oxygenation, salt production for crops, production, mixing, mixing, acid method, chemical method, stirring, nitrate, liquid, ammonium Can use acid to nitrogen and more of which can be used to describe the basic steps and the steps to be carried out in step e, page 19, 538121 _ Case No. 90123049 _ month and month amendments _ 6, patent application In the method of indium tin powder, the method of drying in step f is direct drying in an oven or drying with a spray dryer. 1 2 · A method for preparing an indium tin oxide powder by an aqueous solution method, the steps are as follows: a. Dissolving: dissolving a substance containing metal indium and metal tin separately in water; b. Mixing: thoroughly mixing the above two solutions, and Stir; c. Precipitation: add lye to the mixed solution, adjust to an appropriate p Η value, so that the originally clarified solution will precipitate; d. Filtration, washing: The above solution is filtered under reduced pressure, and re-dispersed with pure water Filter cake, repeat this action several times to form a water-washed suspension; e. Degumming: add acid to the water-washed suspension, adjust to the appropriate pH value, and stir to degumming; f. Drying: the above The de-glued suspension is dried to obtain a white powder of Indium Tin Hydroxide; g. Burning: Put the white powder of Indium Hydroxide / Tin into a high-temperature furnace and pass an appropriate heating rate , Holding temperature and holding time, sintered into yellow-green indium tin oxide powder (Indium Tin Oxide) powder. Page 20