METHOD FOR PRODUCING MOLYBDENUM TRIOXIDE HAVING LOWERED Sb CONTENT

Abstract

The present disclosure addresses the problem of providing a method for producing molybdenum trioxide having a lowered Sb content. A method for producing molybdenum trioxide according to the present invention includes: a step for mixing a raw material constituted of molybdenum compounds or hydrates thereof with chlorine, hydrogen chloride or a chloride; and a step for heating the obtained mixture at a temperature of 70°C or higher. Alternatively, a method for producing molybdenum trioxide according to the present invention includes: a step for mixing ammonium chloride with a raw material constituted of molybdenum trioxide, ammonium molybdate or hydrates of these; and a step for heating the obtained mixture at a temperature of 180ºC or higher.

Description

Method for producing molybdenum trioxide with reduced Sb content

[0001] The present invention relates to a method for producing molybdenum trioxide having a reduced Sb content.

[0002] Molybdenum (Mo) has low electrical resistivity and chemical stability, and is therefore expected to be used as an electronic device material, such as contact plugs in large-scale integrated circuits (LSIs), wiring, word lines in semiconductor memories, or diffusion barrier layers under wiring. For example, a layer made of molybdenum or a compound thereof is formed using chemical vapor deposition (CVD), in which a molybdenum-containing compound is evaporated as a precursor, and then decomposed and reacted on the substrate surface to form a thin film. In recent years, in order to form a uniform molybdenum layer in a high-aspect ratio recess, a technique has also been used in which a thin layer of molybdenum is formed using atomic layer deposition (ALD), and then a thicker layer is formed by CVD, plating, or the like.

[0003] When forming a layer made of molybdenum or a compound thereof using CVD or ALD, molybdenum oxychloride, a compound of chlorine and molybdenum oxide, is used as a precursor. Molybdenum oxychloride is generally synthesized by chlorinating molybdenum oxide with chlorine gas. High-purity molybdenum oxide is used as the raw material. Patent Documents 1 to 4, for example, are cited as examples of methods for producing high-purity molybdenum or molybdenum oxide. These patent documents disclose a method for producing high-purity molybdenum trioxide (molybdenum oxide) by dissolving molybdenum trioxide in aqueous ammonia, precipitating and separating impurity elements, crystallizing ammonium molybdate using an acid, and roasting the crystallized product.

[0004] Japanese Patent Publication No. 6-10090 Publication No. 2-141507 Publication No. 5-64683 Publication No. 3-7607

[0005] Molybdenum oxychloride, used as a precursor for CVD and ALD, is synthesized by chlorinating molybdenum oxides such as molybdenum trioxide with chlorine gas. To increase the purity of the precursor, molybdenum oxychloride, the raw material, molybdenum oxide, must be purified. Conventionally, molybdenum trioxide raw material is dissolved in aqueous ammonia, filtered to remove solid impurities, and then nitric acid is added to precipitate ammonium molybdate, which is then roasted to produce molybdenum trioxide.

[0006] However, the molybdenum trioxide obtained by this method has the problem that it is difficult to reduce the antimony (Sb) impurity, or the reduction effect is low, and repeated purification is required to reduce the Sb content, resulting in increased purification costs. In view of these problems, an object of the present disclosure is to provide a method for producing molybdenum trioxide that can reduce the Sb content.

[0007] The gist of the present disclosure includes the following: [1] A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of a molybdenum compound or a hydrate thereof with chlorine, hydrogen chloride, or a chloride, and heating the resulting mixture at 70°C or higher. [2] A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof with ammonium chloride, and heating the resulting mixture at 180°C or higher. [3] A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof with an aqueous solution containing ammonium chloride, and heating the resulting mixture at 180°C or higher. [4] A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof with aqueous ammonia, followed by adding hydrochloric acid, and heating the resulting mixture at 180°C or higher. [5] A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof with hydrochloric acid, followed by adding ammonium water, and heating the resulting mixture at 180°C or higher. [6] A method for producing molybdenum trioxide according to any one of [1] to [5] above, wherein the Sb content in the produced molybdenum trioxide is ⅓ or less, by weight, of the Sb content in the raw material. [7] A method for producing molybdenum trioxide according to any one of [1] to [6] above, wherein the S content in the produced molybdenum trioxide is ½ or less, by weight, of the S content in the raw material. [8] A method for producing molybdenum trioxide according to any one of [1] to [7], wherein the Sb content in the produced molybdenum trioxide is 0.2 ppm by weight or less. [9] A method for producing molybdenum trioxide according to any one of [1] to [8], wherein the S content in the produced molybdenum trioxide is 0.1 ppm by weight or less.

[0008] According to the present invention, it is possible to provide a method for producing molybdenum trioxide with a reduced Sb content.

[0009] Antimony trioxide (Sb ２ O ３The thermodynamic equilibrium calculation results (vertical axis is log １０ This figure shows the thermodynamic equilibrium calculation results (the vertical axis is log (gram)) when a system consisting of a mixture of metallic antimony (Sb) and hydrogen chloride (HCl) is heated from 0°C to 500°C. １０ (grams)). ２ O ３ ) and ammonium chloride (NH ４ Thermodynamic equilibrium calculation results (vertical axis is log １０ (gram)) is a diagram showing the relationship between metallic antimony (Sb) and ammonium chloride (NH ４ Thermodynamic equilibrium calculation results (vertical axis is log １０ 1 is a diagram showing an XRD pattern of molybdenum trioxide obtained by the manufacturing method of the present disclosure.

[0010] (First embodiment) [Raw material] Molybdenum trioxide (MoO ３ ), ammonium molybdate ((NH ４ ) Mo ７ O ２４ ), or other molybdenum compounds, or raw materials consisting of these hydrates are used. It is preferable to use raw materials with few impurities, and it is preferable to use raw materials with a purity of 90% by weight or more, 99% by weight or more, or 99.9% by weight or more. According to the present disclosure, even when high-purity raw materials are used, the Sb content, which is difficult to remove or has a low removal effect using conventional methods, can be significantly reduced.

[0011] [Mixing step] Molybdenum trioxide (MoO ３ ), ammonium molybdate ((NH ４ ) Mo ７ O ２４ ), or other molybdenum compounds, or raw materials consisting of these hydrates, and chlorine (Cl ２ ), and hydrogen chloride (HCl) or chloride.

[0012] [Heating Step] FIG. 1 shows antimony oxide (Sb ２ O ３ 1 shows the results of a thermodynamic equilibrium calculation when a system consisting of a mixture of molybdenum trioxide (MO) and hydrogen chloride (HCl) is heated from 0°C to 500°C under an air atmosphere. (s) represents the solid phase, and (g) represents the gas phase. The calculation was performed using the thermodynamic equilibrium calculation software Factsage. Antimony (Sb) contained in the raw materials, molybdenum trioxide, ammonium molybdate, or other molybdenum compounds or their hydrate raw materials, is thought to exist as antimony oxide. According to the thermodynamic calculation in FIG. 1, by heating in the presence of hydrogen chloride, antimony (Sb) in the antimony oxide reacts with hydrogen chloride to form antimony trichloride (SbCl ３ This antimony trichloride becomes liquid at temperatures above 70°C, and a portion of it volatilizes as vapor. Furthermore, at temperatures above 100°C, it cannot exist as a solid or liquid, but becomes gas and is desorbed from the system, making it possible to reduce Sb present as an impurity (in the form of antimony oxide) in the raw material.

[0013] FIG. 2 shows the results of thermodynamic equilibrium calculations when a system consisting of a mixture of antimony (Sb) and hydrogen chloride (HCl) is heated from 0°C to 500°C under an air atmosphere. (s) represents the solid phase, and (g) represents the gas phase. The calculations were performed using the thermodynamic equilibrium calculation software Factsage. Even if the antimony (Sb) contained in the raw material molybdenum trioxide, ammonium molybdate, or other molybdenum compounds or hydrates thereof exists in a form other than antimony oxide, for example, as metallic antimony, the thermodynamic calculations in FIG. 2 show that when heated in the presence of hydrogen chloride, it reacts with hydrogen chloride to form antimony trichloride (SbCl ３ This antimony trichloride becomes liquid at temperatures above 70°C, and a portion of it volatilizes as vapor. Furthermore, at temperatures above 145°C, it cannot exist as a solid or liquid, but becomes gas and is desorbed from the system, making it possible to reduce Sb present as an impurity (in the form of metallic antimony) in the raw material.

[0014] In one aspect of the present disclosure, a raw material consisting of ammonium molybdate or a hydrate thereof is mixed with ammonium chloride, and the resulting mixture is heated to 70°C or higher, whereupon chlorine, hydrogen chloride, or chloride reacts with Sb, an impurity contained in the raw material, to produce SbCl. ３ (gas) and can be desorbed. The heating temperature is preferably 100°C or higher, more preferably 145°C or higher. There is no particular upper limit to the heating temperature, but it is preferably 550°C or lower. The heating time is preferably 1 hour or longer, although this depends on the amount of raw material and the heating temperature. There is no particular upper limit to the heating time, but in terms of energy cost, it is preferably 72 hours or less, and more preferably 48 hours or less. Excess chlorine, hydrogen chloride, or chloride added can be desorbed in the form of gas. Furthermore, since the molybdenum compound or its hydrate, which is the raw material, becomes molybdenum trioxide (solid) by heating, molybdenum trioxide with a reduced Sb content can be simultaneously produced.

[0015] Second Embodiment [Raw Material] Molybdenum trioxide (MoO ３ ), ammonium molybdate ((NH ４ ) Mo ７ O ２４ ), or a raw material consisting of these hydrates. It is preferable to use a raw material with few impurities, and it is preferable to use a raw material with a purity of 90% by weight or more, 99% by weight or more, or 99.9% by weight or more. According to the present disclosure, even when a high-purity raw material is used, it is possible to significantly reduce the Sb content, which is difficult to remove or has a low removal effect using conventional methods.

[0016] [Mixing step] A raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof is mixed with ammonium chloride or an aqueous solution containing ammonium chloride. Examples of mixing combinations include the following: 1) A method of mixing molybdenum trioxide, ammonium molybdate, or a hydrate thereof (all solids) with ammonium chloride (solid); 2) A method of mixing molybdenum trioxide, ammonium molybdate, or a hydrate thereof with an aqueous solution containing ammonium chloride; 3) A method of mixing molybdenum trioxide, ammonium molybdate, or a hydrate thereof with ammonium water, followed by addition of hydrochloric acid; and 4) A method of mixing molybdenum trioxide, ammonium molybdate, or a hydrate thereof with hydrochloric acid, followed by addition of ammonium water.

[0017] [Heating Step] FIG. 3 shows antimony trioxide (Sb ２ O ３ ) and ammonium chloride (NH ４ The figure shows the results of thermodynamic equilibrium calculations when a system consisting of a mixture of molybdenum trioxide, ammonium molybdate, other molybdenum compounds, and antimony trichloride (SbCl) is heated from 0°C to 500°C under air. (s) represents the solid phase, and (g) represents the gas phase. The calculations were performed using the thermodynamic equilibrium calculation software FactSage. It is believed that the antimony (Sb) contained in the raw materials molybdenum trioxide, ammonium molybdate, or other molybdenum compounds, or their hydrates, exists as antimony oxide. According to the thermodynamic calculations in Figure 3, when antimony oxide is heated in the presence of ammonium chloride, antimony (Sb) reacts with ammonium chloride to form antimony trichloride (SbCl). ３ ) and ammonia (NH ３ Both antimony trichloride and ammonia are gases and are desorbed from the system, making it possible to reduce the amount of Sb present as an impurity in the raw material.

[0018] Figure 4 shows the relationship between antimony (Sb) and ammonium chloride (NH ４4 shows the results of thermodynamic equilibrium calculations when a system consisting of a mixture of molybdenum trioxide, ammonium molybdate, or other molybdenum compounds, or their hydrates, is heated from 0°C to 500°C under air. (s) represents the solid phase, and (g) represents the gas phase. The calculations were performed using the thermodynamic equilibrium calculation software Factsage. Even if the antimony (Sb) contained in the raw material molybdenum trioxide, ammonium molybdate, or other molybdenum compounds, or their hydrates, exists in a form other than antimony oxide, for example, as metallic antimony, the thermodynamic calculations in FIG. 4 show that when heated in the presence of ammonium chloride, antimony (Sb) and ammonium chloride react to form ammonium trichloride (SbCl). ２ ) and ammonia (NH ３ Both the antimony trichloride and ammonia are gases and are released from the system, making it possible to reduce the amount of Sb present as an impurity in the raw material.

[0019] In one embodiment of the present disclosure (corresponding to (1) in the mixing step column), a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof is mixed with ammonium chloride, and the resulting mixture is then heated at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher). When this mixture is heated, the ammonium chloride reacts with Sb, an impurity contained in the raw material, to produce SbCl. ３ (gas) and can be desorbed. There is no particular upper limit on the heating temperature, but it is preferably 550°C or lower. The heating time is preferably 1 hour or longer, although this depends on the amount of raw material and the heating temperature. There is no particular upper limit on the heating time, but in terms of energy cost, it is preferably 72 hours or less, and more preferably 48 hours or less. Ammonium chloride added in excess can be desorbed in the form of gas. Furthermore, since ammonium molybdate or a hydrate thereof, which is the raw material, becomes molybdenum trioxide (solid) when heated, molybdenum trioxide with a reduced Sb content can be simultaneously produced.

[0020] In one embodiment of the present disclosure (corresponding to (2) in the mixing step column), a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof is mixed with an aqueous solution containing ammonium chloride, and then the mixture is heated. When this mixture is heated, the water evaporates and ammonium chloride precipitates, and the precipitated ammonium chloride reacts with Sb, an impurity contained in the raw material, to produce SbCl. ３ In this case, the mixture may be heated at a relatively low temperature of about 100°C to evaporate water and precipitate ammonium chloride and the molybdenum compound, and then heated at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher), or may be heated from the beginning at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher) without such stepwise heating.

[0021] In one embodiment of the present disclosure (corresponding to (3) in the mixing step column), a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof is mixed with ammonium water. At this time, some or all of the raw material will dissolve in the ammonia water depending on the pH and the amount of ammonia water added, but some will remain undissolved. Furthermore, pure water can be added to this mixed solution, but the amount of pure water to be added is not particularly important. Next, hydrochloric acid is mixed with the mixed solution. The amount of hydrochloric acid to be mixed is not important, but it is preferably added until the pH reaches 9 to 6. At this time, a molybdenum compound or molybdenum compound ion, ammonium ion, and chloride ion are present in the mixture.

[0022] Next, the mixture to which hydrochloric acid has been added is heated. The water evaporates as a result of heating, and ammonium chloride precipitates. The precipitated ammonium chloride reacts with Sb, an impurity contained in the raw materials, to form SbCl ３In this case, the mixture may be heated at a relatively low temperature of about 100°C to evaporate water and precipitate ammonium chloride and the molybdenum compound, and then heated at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher), or may be heated from the beginning at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher) without such stepwise heating.

[0023] In one embodiment of the present disclosure (corresponding to (4) in the mixing step column), a raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof can be mixed with hydrochloric acid. At this time, the raw material is suspended in the hydrochloric acid without dissolving. When this suspension is heated to 55-65°C, some or all of the raw material dissolves depending on the amount of hydrochloric acid added. When ammonia water is added while maintaining the temperature of this mixture at approximately 60°C, ammonium molybdate and ammonium chloride precipitate. After precipitation, the mixture is allowed to stand for approximately 30 minutes, and the supernatant liquid and solids (ammonium molybdate and ammonium chloride) are separated by decantation. This series of steps may be repeated, or the solids obtained by precipitation and separation may be mixed with hydrochloric acid and heated again, followed by addition of ammonium water to precipitate and separate ammonium molybdate and ammonium chloride. The precipitated and separated solids are then heated at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher). As a result, the impurity Sb contained in the raw material reacts with ammonium chloride to produce gaseous SbCl ３ and can be desorbed from the solid.

[0024] Furthermore, in one embodiment of the present disclosure (corresponding to (4) in the mixing step column), heating may not be necessary after mixing the raw material consisting of molybdenum trioxide, ammonium molybdate, or a hydrate thereof with hydrochloric acid. Depending on the amount of hydrochloric acid added, the raw material may dissolve, but dissolution is not necessary. Next, ammonia water is added to this mixed solution to produce a mixture of the raw material and an aqueous solution containing ammonium chloride. Next, this mixture is heated at 180°C or higher (preferably 270°C or higher, more preferably 400°C or higher). This causes the Sb impurity contained in the raw material to react with ammonium chloride, resulting in the formation of gaseous SbCl. ３ and can be desorbed from the solid.

[0025] The above-described manufacturing method makes it possible to obtain molybdenum trioxide with reduced Sb, which is difficult to remove or only effectively removed by conventional methods. In particular, the Sb content can be reduced to 1 / 3 or less by weight of the Sb content contained in the raw material. It can also be reduced to 1 / 5 or less, and particularly to 1 / 10 or less. Furthermore, the Sb content can be reduced to 0.2 ppm by weight or less, or even 0.1 ppm by weight or less. Even when using raw materials with high or low purity, the Sb content can be reduced to 0.05 ppm by weight or less by increasing the amount of ammonium chloride mixed.

[0026] Regarding the reduction of S, the manufacturing method of the present disclosure makes it possible to obtain molybdenum trioxide with reduced S. In particular, the S content can be reduced to ½ or less by weight of the S content contained in the raw material. It can also be reduced to ⅓ or less, and particularly to 1 / 10 or less. Furthermore, the S content can be reduced to 0.1 ppm by weight or less, and when a highly pure raw material is used, it can be reduced to 0.05 ppm by weight or less.

[0027] The following description will be given based on examples and comparative examples. Note that these examples are merely examples and are not intended to limit the scope of the present invention. The present invention is limited only by the scope of the claims, and includes various modifications other than the examples included in the present invention.

[0028] Example 1: 75 g of ammonium molybdate tetrahydrate raw material with a purity of 99.9% or higher was mixed with 150 ml of aqueous ammonia (concentration: 28 wt%) and 250 ml of water. The ammonium molybdate raw material was dissolved in the aqueous ammonia. This solution was then mixed with 100 ml of hydrochloric acid (concentration: 36 wt%). The pH was adjusted to 6.99. The resulting solution was heated at 480°C for 8 hours to obtain molybdenum trioxide (solid). Analysis using ICP-MS (inductively coupled plasma mass spectrometry) revealed that the Sb content in the raw ammonium molybdate tetrahydrate was 0.6 ppm by weight, whereas the Sb content in the final molybdenum trioxide was less than 0.1 ppm by weight (below the detection limit), achieving a reduction of Sb to less than one-sixth of the Sb content in the raw material.

[0029] Example 2: 75 g of molybdenum trioxide raw material with a purity of 98% or higher was mixed with 150 ml of aqueous ammonia (concentration: 28 wt%) and 250 ml of water. The molybdenum trioxide raw material was dissolved in the aqueous ammonia. This solution was then mixed with 65 ml of hydrochloric acid (concentration: 36 wt%). The pH was adjusted to 8.26. The resulting solution was heated at 480°C for 5 hours to obtain molybdenum trioxide (solid). Analysis using ICP-MS (inductively coupled plasma mass spectrometry) revealed that the Sb content in the raw molybdenum trioxide was 3.2 ppm by weight, while the Sb content in the final molybdenum trioxide was 0.2 ppm by weight, a reduction of 1 / 16 of the Sb content in the raw material.

[0030] Example 3: 75 g of molybdenum trioxide raw material with a purity of 98% or higher was mixed with 363 ml of hydrochloric acid (concentration: 36 wt%). The molybdenum trioxide raw material was insoluble in hydrochloric acid. This suspension was heated at 60°C for 1 hour to dissolve the molybdenum trioxide raw material. While maintaining the temperature of this solution at 60°C, 270 mL of ammonia water (concentration: 28 wt%) was added. Ammonium molybdate (solid) and ammonium chloride (solid) were obtained in the solution, and the pH of the supernatant was 1.00. This suspension containing ammonium molybdate was allowed to stand for 30 minutes, and then the supernatant was removed by decantation. Hydrochloric acid was added to this ammonium molybdate (solid), and the mixture was heated at 60°C for 1 hour. Then, ammonia water was added, the mixture was allowed to stand, and the supernatant was removed by decantation. This procedure was repeated three times. The ammonium molybdate (solid) thus obtained was heated at 480°C for 6 hours to obtain molybdenum trioxide (solid). Analysis using ICP-MS (inductively coupled plasma mass spectrometry) showed that the Sb content in the raw material molybdenum trioxide was 3.2 ppm by weight, while the Sb content in the final molybdenum trioxide was less than 0.1 ppm by weight (below the detection limit), meaning that the Sb content was reduced to less than 1 / 32 of the Sb content in the raw material. Analysis using GD-MS (glow discharge mass spectrometry) showed that the Sb content in the final molybdenum trioxide was less than 0.05 ppm by weight (below the detection limit), and the S content was less than 0.05 ppm by weight (below the detection limit). The S content was reduced to less than 1 / 17 of the S content in the raw material.

[0031] Example 4: Ammonium chloride (999 g) with a purity of 99.5% or higher was mixed with 5002 g of ammonium molybdate tetrahydrate raw material having a purity of 98% or higher. The mixture was in powder form. This mixture was heated at 480°C for 6 hours to obtain a gray solid. Analysis by XRD revealed that all observed peaks were attributable to molybdenum trioxide, as shown in Figure 5, confirming that the resulting solid substance was molybdenum trioxide. Analysis using ICP-MS (inductively coupled plasma mass spectrometry) revealed that the Sb content in the raw ammonium molybdate tetrahydrate was 0.5 ppm by weight, while the Sb content in the final molybdenum trioxide was less than 0.1 ppm by weight (below the detection limit), achieving a reduction of less than one-fifth of the Sb content in the raw material. Furthermore, analysis using GD-MS (glow discharge mass spectrometry) revealed that the Sb content in the final molybdenum trioxide was less than 0.05 ppm by weight (below the detection limit). Furthermore, the S content in the raw material ammonium molybdate tetrahydrate was 3.1 ppm by weight, whereas the S content in the finally obtained molybdenum trioxide was 0.96 ppm by weight, which was reduced to approximately one-third of the S content in the raw material.

[0032] Comparative Example 1: 250 ml of water was mixed with 75 g of ammonium molybdate tetrahydrate raw material with a purity of 99.9% or higher. The resulting solution was heated at 470°C for 8 hours to obtain molybdenum trioxide (solid). Analysis using ICP-MS (inductively coupled plasma mass spectrometry) showed that the Sb content in the raw ammonium molybdate tetrahydrate was 0.6 ppm by weight, while the Sb content in the final molybdenum trioxide was 0.6 ppm by weight, showing no change.

[0033] According to an embodiment of the present invention, it is possible to reduce the content of antimony (Sb), which is difficult or only poorly removed using conventional methods, potentially improving quality. Improved quality leads to a stable supply of products and reduced loss of metal raw materials, which are limited resources. Therefore, one embodiment of the present invention may contribute to Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," and Goal 12, "Ensure sustainable consumption and production patterns," of the United Nations-led Sustainable Development Goals (SDGs).

[0034] The molybdenum trioxide obtained by the production method according to the embodiment of the present invention is particularly useful as a molybdenum oxychloride raw material used as a precursor for CVD or ALD.

Claims

1. A method for producing molybdenum trioxide, comprising the steps of: mixing a raw material consisting of a molybdenum compound or a hydrate thereof with chlorine or chloride (excluding hydrogen chloride); and heating the resulting mixture at 70°C or higher.

2. A method for producing molybdenum trioxide, comprising the steps of: mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or hydrates thereof with ammonium chloride; and heating the resulting mixture at 180°C or higher.

3. A method for producing molybdenum trioxide, comprising the steps of: mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or hydrates thereof with an aqueous solution containing ammonium chloride; and heating the resulting mixture at 180°C or higher.

4. A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or hydrates thereof with ammonia water, then mixing with hydrochloric acid, and heating the resulting mixture at 180°C or higher without filtering.

5. A method for producing molybdenum trioxide, comprising the steps of mixing a raw material consisting of molybdenum trioxide, ammonium molybdate, or hydrates thereof with hydrochloric acid, then mixing with ammonium water, and heating the resulting mixture at 180°C or higher without filtering.

6. A method for producing molybdenum trioxide according to any one of claims 1 to 5, wherein the Sb content in the produced molybdenum trioxide is 1 / 3 or less by weight relative to the Sb content in the raw materials.

7. A method for producing molybdenum trioxide according to any one of claims 1 to 5, wherein the sulfur content in the produced molybdenum trioxide is 1 / 2 or less by weight relative to the sulfur content in the raw materials.

8. The molybdenum trioxide according to any one of claims 1 to 5, wherein the Sb content in the manufactured molybdenum trioxide is 0.2 ppm by weight or less. Manufacturing method.

9. A method for producing molybdenum trioxide according to any one of claims 1 to 5, wherein the sulfur content in the produced molybdenum trioxide is 0.1 ppm by weight or less.