Storage device

Abstract

To provide a storage device capable of precisely removing residues in a storage tank.SOLUTION: A storage device comprises: a storage tank 2 for storing storage substances of a liquid or solid state; a solvent tank 3 for storing a solvent; a path part 4 which supplies inert gas to the solvent tank 3, exhausts gas from the storage tank 2, supplies the solvent from the solvent tank 3 to the storage tank 2 according to supply of the inert gas to the solvent tank 3 and exhaustion of gas from the storage tank 2, supplies inert gas to the storage tank 2, and exhausts the solvent from the storage tank 2 according to supply of the inert gas to the storage tank 2; and a detection part 5 for detecting the storage substances in the solvent supplied to the storage tank 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a storage device.

Background Art

[0002] Devices for cleaning storage tanks are known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A storage device having a storage tank for storing a storage substance in a liquid or solid state preferably can precisely remove the residue of the storage substance remaining in the storage tank after use in order to suppress the mixing of impurities and maintain the high purity of the storage substance while repeatedly using the storage tank.

[0005] Therefore, an object of the present invention is to provide a storage device that can precisely remove the residue of a storage tank.

Means for Solving the Problems

[0006] One aspect of the present invention is as follows.

[0007] [1] A storage tank for storing a storage substance in a liquid or solid state, A solvent tank for storing a solvent, An inert gas can be supplied to the solvent tank, a gas can be discharged from the storage tank, the solvent can be supplied from the solvent tank to the storage tank by supplying the inert gas to the solvent tank and discharging the gas from the storage tank, an inert gas can be supplied to the storage tank, and a path section capable of discharging the solvent from the storage tank by supplying the inert gas to the storage tank, A storage device having a detection unit that detects the stored substance in the solvent supplied to the storage tank.

[0008] [2] Having an acid-alkaline solution tank for storing an acid-alkaline solution which is an acidic or alkaline solution, The path section can supply an inert gas to the acid-alkaline solution tank, the acid-alkaline solution can be supplied from the acid-alkaline solution tank to the storage tank by supplying the inert gas to the acid-alkaline solution tank and discharging the gas from the storage tank, and the acid-alkaline solution can be discharged from the storage tank by supplying the inert gas to the storage tank. The storage device according to [1].

[0009] [3] The path section can supply an inert gas into the acid-alkaline solution in the storage tank. The storage device according to [2].

[0010] [4] The acid-alkaline solution is an acidic solution containing nitric acid, citric acid or hydrofluoric acid, or an alkaline solution containing aqueous ammonia. The storage device according to [2] or [3].

[0011] [5] Having a reuse tank for storing the acid-alkaline solution, The path section can discharge gas from the reuse tank, and can supply the acid / alkaline solution from the storage tank to the reuse tank by supplying inert gas to the storage tank and discharging gas from the reuse tank, and can also supply the acid / alkaline solution from the reuse tank to the storage tank by supplying inert gas to the reuse tank and discharging gas from the storage tank. The storage device according to any one of [2] to [4].

[0012] [6] The path section can supply deionized water to the storage tank and can discharge the deionized water from the storage tank. The storage device according to any one of [1] to [5].

[0013] [7] The path section can circulate the deionized water through the storage tank. The storage device according to [6].

[0014] [8] It has a heating section capable of heating the storage tank, The path section can dry the storage tank by supplying inert gas to the storage tank in a state where the temperature has risen due to the heating section. The storage device according to any one of [1] to [7].

[0015] [9] The stored substance is an organic or inorganic metal compound that is in a liquid or solid state at 25°C and 1 atm. The storage device according to any one of [1] to [8].

[0016]

[10] The solvent is an organic compound. The storage device according to any one of [1] to [9].

[0017]

[11] The detection section is composed of a pH meter, a spectrometer, a colorimeter, an ultrasonic meter, or a mass spectrometer. The storage device according to any one of [1] to

[10] .

Advantages of the Invention

[0018] According to the present invention, a storage device capable of precisely removing residues in a storage tank can be provided.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be exemplarily described with reference to the drawings.

[0021] As shown in FIG. 1, in the first embodiment of the present invention, the storage device 1 includes a storage tank 2 for storing a storage substance in a liquid or solid state, a solvent tank 3 for storing a solvent, an inert gas can be supplied to the solvent tank 3, gas can be discharged from the storage tank 2, and the solvent can be supplied from the solvent tank 3 to the storage tank 2 by supplying the inert gas to the solvent tank 3 and discharging the gas from the storage tank 2, an inert gas can be supplied to the storage tank 2, and a path portion 4 capable of discharging the solvent from the storage tank 2 by supplying the inert gas to the storage tank 2, and a detection unit 5 for detecting the storage substance in the solvent supplied to the storage tank 2.

[0022] According to the above configuration, an inert gas is supplied to the solvent tank 3 (for example, at 0.1 MPaG or higher and pumped), and the gas is discharged from the storage tank 2. As a result, the solvent is supplied from the solvent tank 3 to the storage tank 2, and the residue of the stored substance remaining in the storage tank 2 is dissolved in the solvent. An inert gas is supplied to the storage tank 2 (for example, at 0.1 MPaG or higher and pumped), and as a result, a solvent treatment step of discharging the solvent from the storage tank 2 can be performed. Further, the solvent treatment step can be repeated until the residue in the storage tank 2 is sufficiently reduced. At that time, by detecting the stored substance in the solvent supplied to the storage tank 2 with the detection unit 5, for example, by comparing the detected value with a threshold value, it can be determined whether the removal of the residue in the storage tank 2 by the solvent is sufficient to end the repetition of the solvent treatment step. Therefore, according to the above configuration, a storage device 1 capable of precisely removing the residue in the storage tank 2 can be realized.

[0023] Also according to the above configuration, by using an inert gas and a solvent, the residue can be treated while suppressing contact with air and moisture. Therefore, it is particularly effective when the stored substance has water repellency and / or corrosiveness. The stored substance is, for example, a film-forming material in a semiconductor process. The path section 4 is constituted by, for example, a sealed pipe. The solvent treatment step can be performed after a stored substance discharge step of supplying an inert gas to the storage tank (for example, at 0.1 MPaG or higher and pumping) and discharging the stored substance from the storage tank by the path section 4. The detection unit 5 can be provided, for example, on the path for discharging the solvent from the storage tank.

[0024] As in the second embodiment shown in FIG. 2, the storage device 1 has an acid / alkali solution tank 6 for storing an acid / alkali solution that is an acidic or alkaline solution. The path section 4 can supply an inert gas to the acid / alkali solution tank 6, and the acid / alkali solution can be supplied from the acid / alkali solution tank 6 to the storage tank 2 by supplying the inert gas to the acid / alkali solution tank 6 and discharging the gas from the storage tank 2. Also, the acid / alkali solution can be discharged from the storage tank 2 by supplying the inert gas to the storage tank 2.

[0025] According to the above configuration, after the completion of the solvent treatment step, an inert gas is supplied (for example, at 0.1 MPaG or more and pumped) to the acid / alkaline solution tank 6, and the gas is discharged from the storage tank 2. As a result, the acid / alkaline solution is supplied from the acid / alkaline solution tank 6 to the storage tank 2, and the residue of the stored substance remaining in the storage tank 2 is dissolved in the acid / alkaline solution. Then, an inert gas is supplied (for example, at 0.1 MPaG or more and pumped) to the storage tank 2, and as a result, an acid / alkaline solution washing step of discharging the acid / alkaline solution from the storage tank 2 can be performed.

[0026] As shown in FIG. 2, the path section 4 may be configured to be able to supply an inert gas into the acid / alkaline solution in the storage tank 2. According to the above configuration, in the acid / alkaline solution washing step, a predetermined amount (for example, 0.1 to 50 slm) of inert gas is supplied into the acid / alkaline solution in the storage tank 2 and bubbled for a predetermined time (for example, 1 minute or more), so that the washing effect by the acid / alkaline solution can be enhanced.

[0027] The acid / alkaline solution is an acidic solution containing nitric acid, citric acid or hydrofluoric acid, or an alkaline solution containing aqueous ammonia. According to the above configuration, the washing effect by the acid / alkaline solution can be stably obtained. The preferred concentration of the acidic solution is nitric acid: 1 to 55%, citric acid: 1 to 30%, hydrofluoric acid: 0.1 to 5%. The preferred concentration of the alkaline solution is aqueous ammonia: 1 to 30%.

[0028] As in the third embodiment shown in FIG. 3, the storage device 1 has a reuse tank 7 for storing the acid / alkaline solution. The path section 4 can discharge the gas from the reuse tank 7, and by supplying the inert gas to the storage tank 2 and discharging the gas from the reuse tank 7, the acid / alkaline solution can be supplied from the storage tank 2 to the reuse tank 7, and by supplying the inert gas to the reuse tank 7 and discharging the gas from the storage tank 2, the acid / alkaline solution can also be supplied from the reuse tank 7 to the storage tank 2.

[0029] According to the above configuration, after the acid / alkaline solution cleaning step, an inert gas is supplied to the storage tank 2 (for example, at 0.1 MPaG or more and pumped), and the gas is discharged from the reuse tank 7. As a result, the acid / alkaline solution can be supplied from the storage tank 2 to the reuse tank 7 and stored. Further, instead of performing the acid / alkaline solution cleaning step next, an inert gas is supplied to the reuse tank 7 (for example, at 0.1 MPaG or more and pumped), and the gas is discharged from the storage tank 2. As a result, an acid / alkaline solution reuse cleaning step of supplying the acid / alkaline solution from the reuse tank 7 to the storage tank 2 can be performed. Thus, according to the above configuration, the reuse of the acid / alkaline solution can be enabled.

[0030] As shown in FIG. 3, the storage device 1 has a pH detection unit 8 on the path for supplying the acid / alkaline solution from the reuse tank 7 to the storage tank 2. The path unit 4 can be configured to select whether to supply the acid / alkaline solution to the storage tank 2 according to the detection result of the pH detection unit 8 (for example, discard it without supplying it to the storage tank 2 and instead supply the acid / alkaline solution from the acid / alkaline solution tank 6 to the storage tank 2). According to the above configuration, it is possible to avoid the reuse of the acid / alkaline solution when it is contaminated to the extent that it is inappropriate for reuse.

[0031] The path unit 4 may be configured to be able to supply an acidic solution to the storage tank 2. According to the above configuration, after the acid / alkaline solution cleaning step (or the acid / alkaline solution reuse cleaning step), the gas is discharged from the storage tank 2 and an acidic solution is supplied to the storage tank 2, and a passivation treatment step of holding it in the storage tank 2 for a predetermined time (for example, 1 minute or more) can be performed to passivate the inner surface of the storage tank 2. By the passivation treatment, corrosion of the storage tank 2 can be suppressed. In this case, the acid / alkaline solution stored in the acid / alkaline solution tank 6 can be made an acidic solution suitable for the passivation treatment, and the configuration of the storage device 1 can be simplified.

[0032] As in the fourth embodiment shown in FIG. 4, the path unit 4 may be configured to be able to supply deionized water to the storage tank 2 and discharge deionized water from the storage tank 2.

[0033] According to the above configuration, after the acid / alkaline solution cleaning step (in the case of a configuration that can also perform the acid / alkaline solution reuse cleaning step by combining the configuration of the third embodiment, after the acid / alkaline solution cleaning step or the acid / alkaline solution reuse cleaning step), or after the passivation treatment step, or when the acid / alkaline solution cleaning step (or the acid / alkaline solution reuse cleaning step) is not performed (it is also possible to combine a configuration that does not perform the acid / alkaline solution cleaning step as in the first embodiment), after the solvent treatment step, deionized water can be supplied to the storage tank 2, the residue of the stored substance remaining in the storage tank 2 can be dissolved in the deionized water, and a deionized water treatment step of discharging the deionized water from the storage tank 2 can be performed.

[0034] As shown in FIG. 4, the storage device 1 may be configured to have a specific resistance value detection unit 9 that detects the specific resistance value of the deionized water supplied to the storage tank 2. According to the above configuration, the deionized water treatment step can be terminated according to the detection result of the specific resistance value detection unit 9. The specific resistance value detection unit 9 is constituted by, for example, a specific resistance meter. In this case, for example, deionized water of 18 MΩ·cm or less is used, and when the detection result becomes, for example, 15 MΩ·cm or more, the deionized water treatment step can be terminated. The specific resistance value detection unit 9 can be provided, for example, on the path for discharging the deionized water from the storage tank. Instead of the specific resistance value detection unit 9, a conductivity detection unit that detects the conductivity of the deionized water supplied to the storage tank 2 may be provided. The conductivity detection unit is constituted by, for example, a conductivity meter.

[0035] As shown in FIG. 4, the path unit 4 may be configured to allow deionized water to flow through the storage tank 2 (for example, at 0.1 to 10 L / min for 60 minutes or more). According to the above configuration, the deionized water treatment step can be efficiently performed.

[0036] As shown in FIG. 4, the storage device 1 may be configured to have a deionized water storage substance detection unit 10 that detects the storage substance in the deionized water supplied to the storage tank 2. According to the above configuration, the deionized water treatment process can be terminated according to the detection result of the deionized water storage substance detection unit 10. The deionized water storage substance detection unit 10 is constituted by, for example, a liquid particle counter. In this case, the deionized water treatment process can be terminated when the detection result is, for example, 10 pieces / L or less. The deionized water storage substance detection unit 10 can be provided, for example, on the path for discharging the deionized water from the storage tank.

[0037] As shown in FIG. 5, the storage device 1 may have a heating unit 11 that can heat the storage tank 2, and the path unit 4 can dry the storage tank 2 by supplying an inert gas to the storage tank 2 in a state where the temperature has risen by the heating unit 11 (5th Embodiment). According to the above configuration, after the solvent treatment process, the acid / alkaline solution washing process (or the acid / alkaline solution reuse washing process), the passivation treatment process, or the deionized water treatment process, a drying process for drying the storage tank 2 can be performed by supplying an inert gas to the storage tank 2 in a state where the temperature has risen by the heating unit 11. Therefore, according to the above configuration, more precise removal of the residue in the storage tank 2 can be realized.

[0038] The 5th Embodiment can be configured as a combination of any of the above-described 1st to 4th Embodiments. The heating unit 11 may be installed in advance with respect to the storage tank 2, or may be installed at another location and configured to move the storage tank 2 to the heating unit 11 at an appropriate timing. The heating unit 11 is constituted by, for example, a thermostatic bath.

[0039] The drying process can be performed, for example, under the conditions that the flow rate of the inert gas is 0.1 to 10 slm, the treatment time is 60 minutes or more, and the temperature inside the storage tank 2 is from room temperature to 150°C.

[0040] As shown in FIG. 5, the storage device 1 may be configured to include a dew point detection unit 12 that detects the dew point of the inert gas supplied to the storage tank 2. According to the above configuration, by detecting the dew point of the inert gas supplied to the storage tank 2 with the dew point detection unit 12, for example, by comparing the detected value with a threshold value, it is possible to determine whether the dry state of the storage tank 2 is sufficient to complete the drying process. The end of the drying process can be determined, for example, by whether the dew point has reached -76°C or lower. The dew point detection unit 12 is constituted by, for example, a dew point meter. The dew point detection unit 12 can be provided, for example, on the path for discharging the inert gas from the storage tank.

[0041] As shown in FIG. 5, the storage device 1 may be configured to include a storage substance detection unit 13 in the inert gas that detects the storage substance in the inert gas supplied to the storage tank 2. According to the above configuration, the drying process can be terminated according to the detection result of the storage substance detection unit 13 in the inert gas. The storage substance detection unit 13 in the inert gas is constituted by, for example, an airborne particle counter. In this case, the drying process can be terminated when the detection result is, for example, 10 pieces / L or less. The storage substance detection unit 13 in the inert gas can be provided, for example, on the path for discharging the inert gas from the storage tank.

[0042] The storage substance is, for example, an organic or inorganic metal compound that is in a liquid or solid state at 25°C and 1 atm. According to the above configuration, the residue in the storage tank 2 can be stably and precisely removed.

[0043] The solvent is, for example, an organic compound (organic solvent). According to the above configuration, the residue in the storage tank 2 can be stably and precisely removed. The organic solvent is not particularly limited, including various process gases, and may be a solvent widely used industrially, such as an organic solvent like octane, a fluorocarbon or chlorinated organic solvent, etc. The organic solvent is generally a liquid at normal temperature (20 - 30 °C) and normal pressure (0.1 MPa), but in the present application, it may also be a solvent liquefied under pressurized conditions or low-temperature conditions. The organic solvent is, for example, a saturated hydrocarbon (such as n-hexane, n-octane, etc.), a cyclic saturated hydrocarbon (such as cyclohexane, etc.), a ketone (such as acetone, etc.), an ester (such as ethyl acetate, etc.), an aromatic compound (such as benzene, toluene, etc.), a cyclic ether compound (such as tetrahydrofuran: THF, etc.), a heterocyclic compound (such as pyridine, piperidine, etc.), acetic acid, a chlorinated hydrocarbon (such as dichloromethane, chloroform, etc.), an amine compound (such as triethylamine, ethylenediamine, etc.), an alcohol (such as methanol, ethanol, etc.).

[0044] The detection unit 5 is constituted by, for example, a pH meter, a spectrometer, a colorimeter, an ultrasonic meter or a mass spectrometer. According to the above configuration, the timing to end the repetition of the solvent treatment process can be stably and appropriately determined. When using a pH meter, the repetition of the solvent treatment process can be ended when the detection result reaches, for example, the blank value of the solvent.

[0045] The storage device 1 may be configured to have a storage substance amount detection unit (not shown) that detects the amount of the storage substance in the storage tank 2. The storage substance amount detection unit is constituted by, for example, a weighing scale that measures the weight of the storage tank 2 in a state where the storage substance is stored, or a liquid level gauge that measures the liquid level of the liquid storage substance in the storage tank 2. The liquid level gauge is constituted by, for example, a liquid level sensor (proximity sensor) that measures the liquid level in a transparent tube connected to the upper and lower parts of the storage tank 2.

[0046] In FIG. 1, the path section 4 includes an inert gas supply common path 17 having a valve 14, a pressure gauge 15, and a flow control device 16 (e.g., a mass flow controller) in this order from upstream to downstream, a first path 18 extending from the downstream end of the inert gas supply common path 17 to the upper part in the storage tank, a second path 19 extending from the downstream end of the inert gas supply common path 17 to the upper part in the solvent tank 3, a third path 20 extending from the lower part in the storage tank 2 to the outside of the storage tank, a fourth path 21 extending from the lower part in the solvent tank 3 to the outside of the storage tank, an exhaust path 22 connected to the first path 18 and the second path 19 respectively, and a drain path 23 connected to the third path 20. The solvent can be supplied from the solvent tank 3 to the storage tank through the fourth path 21 and the third path 20, and can be discharged from the storage tank through the third path 20 and the drain path 23.

[0047] In FIG. 2, in addition to the configuration of FIG. 1, the path section 4 includes a fifth path 24 extending from the downstream end of the inert gas supply common path 17 to the upper part in the acid / alkaline solution tank 6, and a sixth path 25 extending from the lower part in the acid / alkaline solution tank 6 to the outside of the acid / alkaline solution tank 6, and the exhaust path 22 is also connected to the fifth path 24. The acid / alkaline solution can be supplied from the acid / alkaline solution tank 6 to the storage tank through the sixth path 25 and the third path 20, and can be discharged from the storage tank through the third path 20 and the drain path 23.

[0048] In FIG. 3, in addition to the configuration of FIG. 2, the path section 4 has a seventh path 26 extending from the downstream end of the inert gas supply common path 17 to the upper part in the reuse tank 7, an eighth path 27 extending from the upper part in the reuse tank 7 to the outside of the reuse tank 7, and a ninth path 28 extending from the lower part in the reuse tank 7 to the outside of the reuse tank 7. The exhaust path 22 is also connected to the seventh path 26, and the ninth path 28 has a liquid filter 29 and a pH detection section 8. The acid / alkaline solution can be supplied from the storage tank to the reuse tank 7 through the third path 20 and the eighth path 27. Also, the acid / alkaline solution can be supplied from the reuse tank 7 to the storage tank through the ninth path 28 and the third path 20, and when the acid / alkaline solution is contaminated to the extent that it is unsuitable for reuse, it can be discharged from the reuse tank 7 through the ninth path 28 and the drain path 23.

[0049] In FIG. 4, in addition to the configuration of FIG. 2, the path section 4 has a deionized water supply path 30 capable of supplying deionized water to the third path 20, and a deionized water discharge path 31 connected to the first path 18 and capable of discharging deionized water. The deionized water discharge path 31 has a detection section 5, a deionized water stored substance detection section 10, a specific resistance value detection section 9, and a flow meter 32.

[0050] In FIG. 5, the path section 4 has a first inert gas supply path 33 connected to the third path 20 and a second inert gas supply path 34 connected to the exhaust path 22. The first inert gas supply path 33 has a flow control device 16, a valve 14, and a pressure gauge 15 in this order from upstream to downstream, and the second inert gas supply path 34 has a flow control device 16 and a valve 14 in this order from upstream to downstream. The exhaust path 22 has a dew point detection section 12 and a stored substance detection section 13 in the inert gas. The inert gas can flow through the first inert gas supply path 33, the third path 20, inside the storage tank 2, the second path 19, and the exhaust path 22 in this order. The inert gas can be appropriately supplied from the second inert gas supply path 34 to the exhaust path 22.

[0051] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

Example

[0052] (Comparative Example 1) As Comparative Example 1, experiments were conducted using the following storage substance and solvent. Storage substance (water-repellent liquid): bis(diethylamino)silane (storage tank capacity: 1 L) Solvent: normal hexane [Experimental method] The storage tank was opened in a draft and rinsed with normal hexane. [Experimental conditions] Solvent treatment under atmospheric exposure [Experimental results] Even at the 10th time of solvent rinsing, the pH exceeded 20 on the full scale and did not reach pH = 5, which is the blank value of normal hexane. Also, solids thought to be hydrolysis products of bis(diethylamino)silane were attached inside the storage tank.

[0053] (Example 1) As Example 1, experiments were conducted using the following storage substance, solvent and acidic solution. Storage substance (water-repellent liquid): bis(diethylamino)silane (storage tank capacity: 1 L) Solvent: normal hexane Acid solution: 25% citric acid [Experiment 1-1: Solvent treatment step] [Experimental method] In the storage device shown in Fig. 1, a storage tank with a capacity of 1 L was filled with bis(diethylamino)silane and then discharged, and a solvent treatment step with a solvent (normal hexane) was carried out. [Experimental conditions] Inert gas for pressure feeding: N2, pressure feeding pressure: 0.1 MPaG, holding time: 1 minute [Experimental results] The blank value of the solvent was reached at the 3rd time of the solvent treatment step. Specifically, for pH 5.0 of normal hexane, the measured pH was 20 or more at the 1st treatment, 8.3 at the 2nd treatment, and 5.3 at the 3rd treatment.

[0054] Experiment 1-2 was carried out after Experiment 1-1. [Experiment 1-2: Acid / alkaline solution washing step, passivation treatment step] [Experimental Method] After the solvent treatment process, an acid / alkaline solution washing process (with bubbling) using an acidic solution (25% citric acid) and a passivation treatment process were carried out. [Experimental Conditions] (1) Bubbling conditions after the introduction of 25% citric acid Inert gas: N2, gas flow rate: 10 slm, pumping pressure: 0.1 MPaG, Bubbling time: 5 minutes (2) 25% citric acid passivation treatment conditions Retention time after the introduction of 25% citric acid: 1 hour [Experimental Results] No reactive residues were confirmed in the storage tank. The results of surface composition analysis by X-ray photoelectron spectroscopy (XPS) before and after treatment are shown. A passivation film rich in chromium oxide film was observed after the passivation treatment process. [Table 1]

[0055] Experiment 1-3 was carried out after Experiments 1-1 and 1-2. [Experiment 1-3: Deionized water treatment process (flow-through)] [Experimental Method] After the passivation treatment process, a deionized water treatment process (flow-through) was carried out. [Experimental Conditions] Deionized water: 18 MΩ·cm, flow rate: 0.5 L / min, pressure: atmospheric pressure [Experimental Results] The results of analyzing the specific resistance value and metal impurity concentration (measurement method: inductively coupled plasma mass spectrometry, ICP-MS) before and after treatment are shown. The specific resistance value reached the deionized water level (≧15 MΩ·cm) after 5 hours of water treatment, and no contamination in the storage tank due to metal impurities was confirmed. Also, the number of particles of 0.1 μm or more in the liquid was 5 particles / L. Specific resistance value (MΩ·cm) Before treatment: 0.01 After treatment (5 hours): 17 [Table 2]

[0056] Experiment 1-4 was carried out after Experiments 1-1, 1-2, and 1-3. [Experiment 1-4: Drying Process] [Experimental Method] The drying process was carried out after the deionized water treatment process (flow-through). [Experimental Conditions] Inert gas: N2, gas flow rate: 10 slm, pumping pressure: 0.1 MPaG [Experimental Results] The results of analyzing the dew point before and after drying are shown. The dew point reached -80 °C after 3 hours of drying. Also, the number of particles of 0.1 μm or more in the air was 1 particle / L. Dew point After 1 hour of drying: -30 °C After 3 hours of drying: -80 °C

[0057] (Comparative Example 2) As Comparative Example 2, experiments were conducted using the following storage substances and solvents. Storage substance (corrosive solid): Molybdenum(VI) dichloride dioxide (storage tank capacity: 1 L) Solvent: Tetrahydrofuran [Experimental Method] The storage tank was opened in a draft, and rinsing with tetrahydrofuran was performed. Then, the inside of the storage tank was flushed with 18 MΩ·cm deionized water. [Experimental Conditions] Solvent treatment under open atmosphere Deionized water: 18 MΩ·cm, flow rate: 0.5 L / min, pressure: atmospheric pressure [Experimental Results] Even at the 10th time of solvent rinsing, the pH was 4.2 and did not reach the blank value of tetrahydrofuran, pH = 8.1. Also, solids suspected to be hydrolysis products of molybdenum(VI) dichloride dioxide adhered to the inside of the storage tank. The solids could not be removed even in the subsequent flushing process with deionized water, and the specific resistance value after 24 hours was 1 MΩ·cm.

[0058] (Example 2) As Example 2, experiments were conducted using the following storage substances, solvents, and acidic solutions. Corrosive solid material: Molybdenum(VI) dichloride dioxide (storage tank capacity: 1 L) Solvent: Tetrahydrofuran [Experiment 2-1: Solvent Treatment Process] [Experimental Method] In the storage device shown in Fig. 1, the 1-L storage tank was filled with molybdenum(VI) dichloride dioxide and then discharged. After that, a solvent treatment process using a solvent (tetrahydrofuran) was carried out. [Experimental Conditions] Inert gas for pressure feeding: N2, pressure for pressure feeding: 0.1 MPaG, holding time: 1 minute [Experimental Results] The blank value of the solvent was reached at the third time of the solvent treatment process. Specifically, for tetrahydrofuran with a pH of 8.1, the measured pH values were 0.4 for the first treatment, 6.9 for the second treatment, and 8.0 for the third treatment.

[0059] Experiment 2-2 was carried out after Experiment 2-1. [Experiment 2-2: Deionized Water Treatment Process (Flow-Through)] [Experimental Method] After the solvent treatment process, a deionized water treatment process (flow-through) was carried out. [Experimental Conditions] Deionized water: 18 MΩ·cm, flow rate: 0.5 L / min, pressure: atmospheric pressure [Experimental Results] The results of analyzing the specific resistance value and metal impurity concentration before and after treatment (measurement method: inductively coupled plasma mass spectrometry, ICP-MS) are shown. The specific resistance value reached the deionized water level (≥15 MΩ·cm) after 5 hours of treatment, and no contamination in the storage tank due to metal impurities was confirmed. Also, the number of particles of 0.1 μm or larger in the liquid was 3 particles / L. Specific resistance value (MΩ·cm) Before treatment: 0.01 After treatment (5 hours): 17

Table 3

[0060] Experiment 2-3 was carried out after Experiments 2-1 and 2-2. [Experiment 2-3: Drying Process] [Experimental Method] After the deionized water treatment process (flow-through), a drying process was carried out. [Experimental Conditions] Inert gas: N2, gas flow rate: 10 slm, pressure: 0.1 MPaG [Experimental Results] The results of analyzing the dew point before and after drying are shown. The dew point reached -80°C after 3 hours of drying. Also, the number of particles of 0.1 μm or more in the air was 1 particle / L. Dew point: -33°C after 1 hour of drying -80°C after 3 hours of drying

Explanation of Symbols

[0061] 1 Storage device 2 Storage tank 3 Solvent tank 4 Path section 5 Detection section 6 Acid / alkaline solution tank 7 Reuse tank 8 pH detection section 9 Specific resistance value detection section 10 Deionized water storage substance detection section 11 Heating section 12 Dew point detection section 13 Inert gas storage substance detection section 14 Valve 15 Pressure gauge 16 Flow control device 17 Inert gas supply common path 18 First path 19 Second path 20 Third path 21 Fourth path 22 Exhaust path 23 Drainage path 24 Fifth path 25 Sixth path 26 Seventh path 27 Eighth path 28 Ninth path 29 Liquid filter 30 Deionized water supply path 31 Deionized water discharge path 32 Flow meter 33 Inert gas supply first path 34 Inert gas supply second path

Claims

1. A storage tank for storing a storage substance in a liquid or solid state, A solvent tank for storing a solvent, A path section capable of supplying an inert gas to the solvent tank, discharging gas from the storage tank, supplying the solvent from the solvent tank to the storage tank by supplying the inert gas to the solvent tank and discharging the gas from the storage tank, capable of supplying an inert gas to the storage tank, and capable of discharging the solvent from the storage tank by supplying the inert gas to the storage tank, A storage device comprising a detection unit for detecting the storage substance in the solvent supplied to the storage tank.

2. Having an acid / alkali solution tank for storing an acid / alkali solution which is an acidic or alkaline solution, The path section is capable of supplying an inert gas to the acid / alkali solution tank, supplying the acid / alkali solution from the acid / alkali solution tank to the storage tank by supplying the inert gas to the acid / alkali solution tank and discharging the gas from the storage tank, and capable of discharging the acid / alkali solution from the storage tank by supplying an inert gas to the storage tank. The storage device according to claim 1.

3. The path section is capable of supplying an inert gas into the acid / alkali solution in the storage tank. The storage device according to claim 2.

4. The acid / alkali solution is an acidic solution containing nitric acid, citric acid or hydrofluoric acid, or an alkaline solution containing aqueous ammonia. The storage device according to claim 2.

5. Having a reuse tank for storing the acid / alkali solution, The path section is capable of discharging gas from the reuse tank, supplying the acid / alkali solution from the storage tank to the reuse tank by supplying an inert gas to the storage tank and discharging the gas from the reuse tank, and capable of supplying the acid / alkali solution from the reuse tank to the storage tank by supplying an inert gas to the reuse tank and discharging the gas from the storage tank. The storage device according to claim 2.

6. The path section is capable of supplying deionized water to the storage tank and discharging the deionized water from the storage tank. The storage device according to claim 1.

7. The path section is capable of circulating the deionized water through the storage tank. The storage device according to claim 6.

8. It has a heating part capable of heating the storage tank, The storage device according to claim 1, wherein the path part can dry the storage tank by supplying an inert gas to the storage tank in a state where the temperature has been raised by the heating part.

9. The storage device according to claim 1, wherein the storage substance is an organic or inorganic metal compound that is in a liquid or solid state at 25°C and 1 atmosphere.

10. The storage device according to claim 1, wherein the solvent is an organic compound.

11. The storage device according to claim 1, wherein the detection part is constituted by a pH meter, a spectrometer, a colorimeter, an ultrasonic meter, or a mass spectrometer.

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