Steam supply device and steam supply method

Abstract

To provide a steam supply device and steam supply method that suppress decrease in concentration of a first substance in a mixed gas due to the discharge of steam of a liquid mixture from a container by using a simple device.SOLUTION: A steam supply device includes: a container that stores a liquid mixture containing a first substance and a second substance with a lower saturated steam pressure than the first substance; an introduction path that introduces carrier gas into the container; a supply path that supplies a mixed gas of the steam of the liquid mixture and the carrier gas from the container to a supply target; a remaining amount measurement device that measures a remaining amount of the liquid mixture in the container; and a concentration control device that performs concentration control which controls the pressure, temperature, or both inside the container to suppress decrease in concentration of the first substance in the mixed gas following the discharge of the steam of the liquid mixture from the container. The concentration control device performs the concentration control according to the remaining amount of the liquid mixture in the container measured by the remaining amount measurement device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a steam supply device and a steam supply method. [Background technology]

[0002] As semiconductors become more highly integrated, new highly reactive raw materials are required for semiconductor manufacturing. Raw materials are supplied in a vapor state to semiconductor manufacturing equipment that processes the material, such as film formation and etching. Until now, pure substances have been used to generate vapor. However, in light of the high reactivity of raw materials, and from the standpoint of maintaining quality and ensuring safety, there are now situations in which solutions or liquid mixtures mixed with solvents are used.

[0003] Examples of vapor supply from a solution or liquid mixture include ToRuSTM from Air Liquide and BRUTE(trademark) Hydrazine from RASIRC. ToRuSTM is a mixture of ruthenium tetroxide and a solvent, and both the solute and the solvent are volatile. In addition, each component of the liquid mixture is volatile, such as the mixed precursor for HfZrO film formation, formic acid containing a trace amount of water, and monomethylhydrazine containing a trace amount of water. In a broad sense, ammonia gas supply from liquid ammonia containing a trace amount of water is also vapor supply from a liquid mixture, and both the main component and impurities are volatile. On the other hand, in the case of BRUTE(trademark) Hydrazine, a solution consisting of hydrazine (N2H4) as a volatile solute and a non-volatile solvent is filled into a container, and only the solute is vaporized at the site of use.

[0004] Unlike pure substances, when vapor is supplied from a liquid mixture, the vapor pressure of each component is affected by the liquid composition, as is known from Raoult's law. Since the vapor composition is determined by the vapor pressure and liquid composition in the pure substance, the liquid composition changes as the vapor supply continues unless it is an azeotropic mixture. As a result, the vapor pressure of each component, i.e., the vapor composition, also changes. Changes in the vapor composition affect the film formation quality. In order to reduce changes in the vapor composition, a method is known in which the components of the liquid mixture are selected so that the vapor pressures of the pure substances of each component are substantially equal (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4681000 Summary of the Invention [Problem to be solved by the invention]

[0006] When a carrier gas is introduced into a container containing a liquid mixture containing a first substance and a second substance having a lower saturated vapor pressure than the first substance, and a mixed gas of the vapor of the liquid mixture and the carrier gas is supplied from the container to a target, it is preferable to use a simple device to suppress a decrease in the concentration of the first substance in the mixed gas that occurs when the vapor of the liquid mixture is discharged from the container.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a vapor supplying device and a vapor supplying method that suppresses the decrease in concentration of a first substance in a mixed gas that accompanies the discharge of vapor of a liquid mixture from a container using a simple device. [Means for solving the problem]

[0008] One aspect of the present invention is as follows.

[0009] [1] A container containing a liquid mixture including a first substance and a second substance having a lower saturated vapor pressure than the first substance; an introduction path for introducing a carrier gas into the container; a supply path for supplying a mixed gas of the vapor of the liquid mixture and the carrier gas from the container to a supply target; a remaining amount measuring device for measuring the remaining amount of the liquid mixture in the container; a concentration control device that performs concentration control to suppress a decrease in the concentration of the first substance in the mixed gas caused by exhausting the vapor of the liquid mixture from the container by controlling the pressure, temperature, or both in the container, The concentration control device performs the concentration control in accordance with the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device.

[0010] [2] The steam supply device according to [1], wherein the remaining amount measuring device is composed of a weight gauge or a liquid level gauge.

[0011] [3] The steam supplying device described in [1] or [2], wherein the concentration control device performs the concentration control according to an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device.

[0012] [4] The concentration control device estimates the concentration of the first substance in the remaining amount of the liquid mixture in the container based on the initial amount of the liquid mixture in the container, the initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device, and performs the concentration control based on the estimation result.

[0013] [5] The steam supply device described in [4], wherein the concentration control device adjusts the concentration of the first substance in the mixed gas to a predetermined target value depending on the estimated result of the concentration of the first substance in the remaining amount of the liquid mixture in the container.

[0014] [6] A vapor supply method for supplying a mixed gas of vapor of the liquid mixture and the carrier gas from a container to a supply target, the method comprising: introducing a carrier gas into a container containing a liquid mixture including a first substance and a second substance having a saturated vapor pressure lower than that of the first substance; A vapor supply method comprising: controlling the pressure, temperature, or both within the container in accordance with the remaining amount of the liquid mixture in the container measured by a remaining amount measuring device, thereby performing concentration control to suppress a decrease in the concentration of the first substance in the mixed gas associated with the discharge of the vapor of the liquid mixture from the container.

[0015] [7] The steam supply method according to [6], wherein the remaining amount of the liquid mixture in the container is obtained by measuring the weight or liquid level.

[0016] [8] The steam supply method according to [6] or [7], wherein the concentration control is performed according to an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container.

[0017] [9] The steam supply method according to [8], further comprising estimating a concentration of the first substance in the remaining amount of the liquid mixture in the container based on an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container, and performing the concentration control based on the estimation result.

[0018]

[10] The steam supply method described in [9], wherein the concentration control adjusts the concentration of the first substance in the mixed gas to a predetermined target value depending on the estimated concentration of the first substance in the remaining amount of the liquid mixture in the container. Effect of the Invention

[0019] According to the present invention, it is possible to provide a vapor supplying device and a vapor supplying method that suppress, by a simple device, a decrease in the concentration of a first substance in a mixed gas that accompanies the discharge of vapor of a liquid mixture from a container. [Brief description of the drawings]

[0020] [Figure 1] 1 is a conceptual diagram showing a steam supply device according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a conceptual diagram showing a steam supply device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] As shown in FIG. 1, in one embodiment of the present invention, the vapor supplying device 1 includes a container 3 containing a liquid mixture 2 containing a first substance and a second substance having a lower saturated vapor pressure than the first substance, an introduction path 4 for introducing a carrier gas into the container 3, a supply path 6 for supplying a mixed gas of the vapor of the liquid mixture 2 and the carrier gas from the container 3 to a supply target 5, a remaining amount measuring device 7 for measuring the remaining amount of the liquid mixture 2 in the container 3, and a concentration control device 8 for performing concentration control to suppress a decrease in the concentration of the first substance in the mixed gas associated with the discharge of the vapor of the liquid mixture 2 from the container 3 by controlling the pressure, temperature, or both within the container 3, and the concentration control device 8 performs concentration control according to the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7.

[0023] According to the above configuration, the concentration can be controlled not according to the concentration of the first substance in the mixed gas measured by a gas concentration meter, but according to the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7. Therefore, since it is sufficient to use the remaining amount measuring device 7 which is simpler than a gas concentration meter, the decrease in the concentration of the first substance in the mixed gas accompanying the discharge of the vapor of the liquid mixture 2 from the container 3 can be suppressed by a simple device.

[0024] The remaining amount measuring device 7 is not particularly limited, but is preferably composed of a weight scale or a liquid level gauge. In this embodiment, the remaining amount measuring device 7 is composed of a weight scale. The weight scale preferably measures the weight of the container 3 containing the liquid mixture 2. The remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7 is not particularly limited, and is, for example, the weight or volume of the liquid mixture 2 in the container 3. The remaining amount of the liquid mixture 2 in the container 3 can be obtained by subtracting the known weight of the container 3 itself from the weight measured by the weight scale. A weight scale that directly measures the weight of the liquid mixture 2 in the container 3 may be used, but a type that measures the weight of the container 3 can be configured more simply. The liquid level gauge may be of any type, such as a contact type or a non-contact type. The remaining amount of the liquid mixture 2 in the container 3 can be obtained from the liquid level measured by the liquid level gauge and the known shape and dimensions of the container 3.

[0025] The concentration control device 8 has a temperature regulator 9 that adjusts the temperature inside the container 3, a pressure regulator 10 that adjusts the pressure inside the container 3, and a processing device 11 that controls the temperature regulator 9 and the pressure regulator 10 to control the concentration according to the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7. According to the above configuration, the concentration control device 8 can be realized with a simple configuration.

[0026] The temperature regulator 9 has a heater for heating the inside of the container 3 or a chiller for cooling the inside of the container 3, or both.

[0027] The pressure regulator 10 is not particularly limited, but is preferably configured as a back pressure valve provided on the supply path 6 as shown in FIG.

[0028] The processing device 11 controls the temperature regulator 9 and the pressure regulator 10 to control the concentration according to the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7 and the temperature inside the container 3 measured by the thermometer 12. According to the above configuration, the accuracy of the concentration control can be improved by utilizing the temperature inside the container 3.

[0029] The concentration control device 8 controls the concentration according to the initial amount of the liquid mixture 2 in the container 3, the initial concentration of the first substance in the liquid mixture 2 in the container 3, and the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7. According to the above configuration, the concentration of the first substance in the mixed gas can be accurately adjusted to a desired target value that is preset in accordance with the supply target 5.

[0030] The concentration control device 8 estimates the concentration of the first substance in the remaining amount of liquid mixture 2 in container 3 based on the initial amount of liquid mixture 2 in container 3, the initial concentration of the first substance in liquid mixture 2 in container 3, and the remaining amount of liquid mixture 2 in container 3 measured by remaining amount measuring device 7, and performs concentration control based on the estimation result (preferably the estimated value). According to the above configuration, the concentration of the first substance in the mixed gas can be adjusted with greater accuracy toward a desired target value that is preset in accordance with the supply target 5.

[0031] The concentration control device 8 adjusts the concentration of the first substance in the mixed gas to a preset target value in accordance with the estimated concentration of the first substance in the remaining amount of liquid mixture 2 in container 3. According to the above configuration, the concentration of the first substance in the mixed gas can be accurately adjusted to a desired target value that is preset in accordance with supply target 5.

[0032] In this embodiment, the first substance is hydrazine, and the second substance is a non-volatile solvent, but is not limited thereto. However, it is preferable that the solution is composed of a volatile or sublimable solute as the first substance and a non-volatile or hardly volatile solvent as the second substance, and that the relationship between the saturated vapor pressure (PP) of the solute, the saturated vapor pressure (PS) of the solvent, the molecular weight (MP) of the solute, and the molecular weight (MS) of the solvent satisfies the following condition A. Condition A: (PP / PS)×(MS / MP)>20000

[0033] In general, when vapor is supplied from a volatile solute and a non-volatile solvent, the impurity concentration (solvent components) in the vapor increases as the remaining amount decreases. If the solution satisfies the above condition A, when the supply target 5 is a semiconductor film deposition chamber, a sufficiently good quality mixed gas with little second substance mixed in as an impurity can be supplied by concentration control until the solute is considerably reduced.

[0034] The liquid mixture 2 is not particularly limited as long as it contains a first substance and a second substance having a lower saturated vapor pressure than the first substance, and can be, for example, a solution in which a gas or solid as a solute is dissolved in a liquid as a solvent, or a liquid mixture in which two or more liquids are mixed. In the solution, the solute may contain two or more substances, and the solvent may contain two or more substances.

[0035] When the liquid mixture 2 is a solution, it may be, for example, a solution containing two or more substances selected from the group consisting of a metal-containing compound, a nitrogen-containing compound, a carbon-containing compound, and an oxygen-containing compound.

[0036] The metal-containing compound may be, for example, a compound containing one or more metal elements selected from the group consisting of silicon (Si), titanium (Ti), tantalum (Ta), aluminum (Al), gallium (Ga), vanadium (V), iron (Fe), zirconium (Zr), niobium (Nb), tungsten (W), molybdenum (Mo), indium (In), hafnium (Hf), cobalt (Co) and ruthenium (Ru). When the metal-containing compound is a halogen metal compound, it may be, for example, selected from the group consisting of TiCl4, Si2Cl6 (HCDS: hexachlorodisilane), SiCl4, SiHCl3, SiH2Cl2, SiH3Cl, SiI4, SiHI3, SiH2I2, SiH3I, TaCl5, AlCl3, GaCl3, ZrCl4, HfCl4, MoO2Cl2, MoCl5, WF6, WCl6 and WCl5. When the metal-containing compound is an organometallic compound, it can be selected from the group consisting of TDMAT (tetrakisdimethylaminotitanium), 3DMAS (trisdimethylaminosilane), BDEAS (bisdiethylaminosilane), BTBAS (bistertiarybutylaminosilane), DIPAS (diisopropylaminosilane), PDMAT (pentakisdimethylaminotantalum), TMA (trimethylaluminum), TMG (trimethylgallium), hafnium-containing compounds, zirconium-containing compounds, cobalt-containing compounds and ruthenium-containing compounds.

[0037] The nitrogen-containing compound may be selected from the group consisting of an amine compound, a hydrazine compound, and ammonia. The amine compound may be selected from the group consisting of methylamine, dimethylamine, ethylamine, diethylamine, and tertiary butylamine. The hydrazine compound may be selected from the group consisting of hydrazine, monomethylhydrazine, dimethylhydrazine, tertiary butylhydrazine, phenylhydrazine, and propylhydrazine. The nitrogen-containing compound is preferably a hydrazine compound, and more preferably hydrazine.

[0038] The carbon-containing compound may be, for example, an organic solvent. The organic solvent may be, for example, selected from the group consisting of a hydrocarbon compound, an alcohol compound, an ether compound, a glycol compound, an amide compound, and a ketone compound. When the organic solvent is a hydrocarbon compound, for example, it may be selected from the group consisting of propane, butane, heptane, pentane, hexane, benzene, toluene, and dimethyl sulfoxide. When the organic solvent is an alcohol compound, for example, it may be selected from the group consisting of methanol, dimethylethanol, ethanol, propanol, methanolamine, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, and propanolamine. When the organic solvent is an ether compound, for example, it may be selected from the group consisting of dimethyl ether, ethyl methyl ether, diethyl ether, tetrahydrofuran, diphenyl ether, crown ether, ethyl acetate, diglyme, and triglyme. When the organic solvent is a glycol compound, for example, it may be selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, and tetraethylene glycol. When the organic solvent is an amide compound, it can be selected from the group consisting of formamide, acetamide, hexamethylphosphoric triamide, tetramethylurea, N-methoxy-N-methylacetamide, N-ethylacetamide, dimethylformamide, and acetanilide, and when the organic solvent is a ketone compound, it can be selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, acetophenone, and benzophenone.

[0039] The oxygen-containing compound may, for example, be selected from the group consisting of water (H2O) and hydrogen peroxide (H2O2).

[0040] 2, the vapor supply device 1 may have a second substance removal device 13 for removing the second substance on the supply path 6. According to the above configuration, the quality of the mixed gas supplied to the supply target 5 can be improved by removing the second substance as an impurity.

[0041] In one embodiment of the present invention, the vapor supply method is a vapor supply method in which a carrier gas is introduced into a container 3 containing a liquid mixture 2 containing a first substance and a second substance having a saturated vapor pressure lower than that of the first substance, and a mixed gas of the vapor of the liquid mixture 2 and the carrier gas is supplied from the container 3 to a supply target 5, and concentration control is performed to suppress a decrease in the concentration of the first substance in the mixed gas associated with the discharge of the vapor of the liquid mixture 2 from the container 3 by controlling the pressure, temperature, or both within the container 3 according to the remaining amount of the liquid mixture 2 in the container 3 measured by a remaining amount measuring device 7. The vapor supply method of this embodiment is performed by the vapor supply device 1 of the embodiment described above, but is not limited thereto.

[0042] According to the above configuration, the concentration can be controlled not according to the concentration of the first substance in the mixed gas measured by a gas concentration meter, but according to the remaining amount of the liquid mixture 2 in the container 3 measured by the remaining amount measuring device 7. Therefore, since it is sufficient to use the remaining amount measuring device 7 which is simpler than a gas concentration meter, it is possible to suppress the decrease in the concentration of the first substance in the mixed gas accompanying the discharge of the vapor of the liquid mixture 2 from the container 3 by a simple method.

[0043] Although the steam supply method is not particularly limited, it is preferable to obtain the remaining amount of the liquid mixture 2 in the container 3 by measuring the weight or the liquid level with the remaining amount measuring device 7. In this embodiment, the remaining amount of the liquid mixture 2 in the container 3 is obtained by measuring the weight with the remaining amount measuring device 7.

[0044] The concentration is controlled according to the initial amount of the liquid mixture 2 in the container 3, the initial concentration of the first substance in the liquid mixture 2 in the container 3, and the remaining amount of the liquid mixture 2 in the container 3. According to the above configuration, the concentration of the first substance in the mixed gas can be accurately adjusted to a desired target value that is preset in accordance with the supply target 5.

[0045] The vapor supply method estimates the concentration of the first substance in the remaining amount of liquid mixture 2 in container 3 based on the initial amount of liquid mixture 2 in container 3, the initial concentration of the first substance in liquid mixture 2 in container 3, and the remaining amount of liquid mixture 2 in container 3, and performs concentration control based on the estimation result (preferably the estimated value). According to the above configuration, the concentration of the first substance in the mixed gas can be adjusted with greater accuracy toward a desired target value that is preset in accordance with supply target 5.

[0046] The concentration control adjusts the concentration of the first substance in the mixed gas to a preset target value in accordance with an estimation result of the concentration of the first substance in the remaining amount of liquid mixture 2 in container 3. According to the above configuration, the concentration of the first substance in the mixed gas can be accurately adjusted to a desired target value preset in accordance with supply target 5.

[0047] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention. EXAMPLES

[0048] <Examples 1-2 and Comparative Example 1: Hydrazine supply from BRUTE™ Hydrazine> In Examples 1 and 2 and Comparative Example 1, a film formation test was carried out by sealing 1 kg of BRUTE (trademark) Hydrazine (BH) in a container 3 using the vapor supply device 1 of the first embodiment shown in Fig. 1, controlling the temperature with a temperature regulator 9 (heater) and a thermometer 12, and controlling the pressure with a pressure regulator 10 (back pressure valve), while introducing 0.744 mol / L (1 slpm) of nitrogen as a carrier gas and supplying hydrazine to a film formation chamber as a supply target 5. In the film formation chamber, a SiN film was formed at 500°C by atomic layer deposition (ALD: Atomic Layer Deposition) using hydrazine vapor and dichlorosilane.

[0049] In Example 1, the temperature inside the container 3 was maintained at 40°C, and the concentration was controlled by adjusting the pressure inside the container 3 by a rate of decrease (constant rate pressure decrease) of 1 kPa for every 33 g of hydrazine supplied, while supplying hydrazine vapor, and the above-mentioned film formation test was carried out.

[0050] In Example 2, the pressure inside the container 3 was maintained at 80 kPa, and the concentration was controlled by adjusting the temperature inside the container 3 at a rate of increase (constant rate temperature increase) of 1°C for every 50 g of hydrazine supplied, while supplying hydrazine vapor and carrying out the above-mentioned film formation test.

[0051] In Comparative Example 1, the above-mentioned film formation test was carried out while the temperature inside the vessel 3 was kept at 40° C. and the pressure inside the vessel 3 was kept at 80 kPa (i.e., without concentration control) regardless of the cumulative amount of hydrazine supplied.

[0052] Table 1 shows the hydrazine concentration in the mixed gas and the amount of film formation per cycle of ALD in Examples 1-2 and Comparative Example 1. In Example 1, hydrazine vapor of a stable concentration could be supplied up to a cumulative hydrazine supply amount of 450 g, and the amount of film formation per cycle was 0.5 nm. When the cumulative supply amount reached 500 g, the hydrazine concentration in the mixed gas decreased, and the amount of film formation per cycle decreased each time the film formation process was performed. In Example 2, hydrazine vapor of a stable concentration could be supplied up to a cumulative hydrazine supply amount of 500 g, and the amount of film formation per cycle was 0.5 nm. When the cumulative hydrazine supply amount exceeded 500 g, the hydrazine concentration in the mixed gas decreased, and the amount of film formation per cycle of ALD decreased each time the film formation process was performed. On the other hand, in Comparative Example 1, when the cumulative hydrazine supply amount reached 300 g, the hydrazine concentration in the mixed gas decreased, and the amount of film formation per cycle decreased each time the film formation process was performed. In consideration of the throughput of the film formation process, a film formation amount per cycle that is large is preferable. In addition, it was confirmed that the films in which the amount of film formed per cycle was reduced in Examples 1 and 2 and Comparative Example 1 contained a large amount of oxygen and carbon impurities. A comparison between Example 1 and Comparative Example 1 shows that it is preferable to lower the pressure inside the vessel in accordance with the cumulative supply amount of mixed vapor. A comparison between Example 2 and Comparative Example 1 shows that it is preferable to raise the temperature inside the vessel in accordance with the cumulative supply amount of mixed vapor.

[0053] [Table 1]

[0054] <Examples 3 to 4 and Comparative Example 2: Supply of hydrazine from a hydrazine solution with a concentration of 50%> In Examples 1-2 and Comparative Example 1, BRUTE (trademark) Hydrazine, in which the weight concentration of hydrazine was 65%, was used, whereas in Examples 3-4, 1 kg of a solution in which the weight concentration of hydrazine was changed to 50% was sealed in container 3, and the above-mentioned film formation test was carried out using the same apparatus as in Examples 1-2 and Comparative Example 1.

[0055] In Example 3, the temperature inside the container 3 was maintained at 40°C, and the concentration was controlled by adjusting the pressure inside the container 3 at a rate of decrease (constant rate pressure decrease) of 1 kPa for every 20 g of hydrazine supplied, while supplying hydrazine vapor, and the above-mentioned film formation test was carried out.

[0056] In Example 4, the temperature inside the container 3 was maintained at 40°C, and the concentration was controlled by adjusting the pressure inside the container 3 by a rate of decrease (constant rate pressure decrease) of 1 kPa for every 33 g of hydrazine supplied, while supplying hydrazine vapor, and the above-mentioned film formation test was carried out.

[0057] In Comparative Example 2, the above-mentioned film formation test was carried out by supplying hydrazine vapor while maintaining the temperature inside the vessel 3 at 40° C. and the pressure inside the vessel 3 at 80 kPa (i.e., without concentration control) regardless of the cumulative amount of hydrazine supplied.

[0058] Table 2 shows the hydrazine concentration in the mixed gas and the amount of film formed per cycle of ALD in Examples 3 to 4 and Comparative Example 2. In Example 3, a stable concentration of hydrazine vapor could be supplied up to an accumulated hydrazine supply amount of 280 g, and the amount of film formed per cycle was 0.47 nm. On the other hand, in Example 4, when the accumulated hydrazine supply amount exceeded 200 g, the hydrazine concentration in the mixed gas decreased, and the amount of film formed per cycle decreased every time the film formation process was performed. Furthermore, in Comparative Example 2, when the accumulated hydrazine supply amount exceeded 100 g, the hydrazine concentration in the mixed gas decreased, and the amount of film formed per cycle decreased every time the film formation process was performed. From the comparison between Example 3 and Comparative Example 2, it can be seen that it is preferable to lower the pressure in the container according to the accumulated amount of mixed vapor supply. Also, from the comparison between Example 3 and Example 4, it can be seen that it is more preferable to set the pressure drop rate according to the initial solution composition.

[0059] [Table 2]

[0060] <Examples 5-6: Estimation of solution concentration> In Examples 5 and 6, as in Examples 1 and 2 and Comparative Example 1, BRUTE (trademark) Hydrazine having a hydrazine weight concentration of 65% was used, and the above-mentioned film formation test was carried out using the same apparatus as in Examples 1 and 2 and Comparative Example 1.

[0061] In Example 5, as concentration control, a solution concentration estimation was performed according to the cumulative amount of hydrazine supplied, and based on the estimation result, hydrazine vapor was supplied while adjusting the pressure inside container 3 (concentration estimation pressure adjustment) so that the hydrazine concentration in the mixed gas was 5%, and the above-mentioned film formation test was performed.

[0062] In Example 6, as concentration control, the solution concentration was estimated when the cumulative supply amount of hydrazine was 300 g, and based on the estimation result, the pressure inside container 3 was adjusted to supply hydrazine vapor so that the hydrazine concentration in the mixed gas was 7%, and the above-mentioned film formation test was performed.

[0063] Table 3 shows the hydrazine concentration in the mixed gas and the amount of film formed per cycle of ALD in Examples 5 and 6. In Example 5, hydrazine vapor with a stable concentration could be supplied up to a cumulative hydrazine supply amount of 500 g, and the amount of film formed per cycle was 0.50 nm. When the cumulative hydrazine supply amount was 550 g, the pressure controller was set to the lower control limit (50 kPa). As a result, the hydrazine vapor concentration decreased, and the amount of film formed per cycle also decreased. In Example 6, the hydrazine concentration increased at a cumulative hydrazine supply amount of 300 g, and the amount of film formed per cycle could be increased. A comparison between Example 5 and Example 1 shows that concentration-estimated pressure adjustment is more preferable than constant-rate pressure reduction.

[0064] [Table 3]

[0065] <Example 7 and Comparative Example 3: Supply of monomethylhydrazine from monomethylhydrazine containing 1% moisture> In Example 7 and Comparative Example 3, a film formation test was performed by sealing a liquid mixture of 99 mol% monomethylhydrazine (MMH) and 1 mol% water (MMH and water each have a vapor pressure) in a container 3 using the vapor supply device 1 of the second embodiment shown in Fig. 2, introducing 0.744 mol / L (1 slpm) of nitrogen as a carrier gas, and maintaining the temperature inside the container 3 at 25°C, while supplying a mixed gas containing a mixed vapor of MMH and water to a film formation chamber while removing moisture with a moisture removal tube as a second substance removal device 13. In the film formation chamber, a SiCN film was formed at 500°C by ALD using MMH vapor and dichlorosilane.

[0066] In Example 7, as concentration control, a concentration estimation was performed according to the cumulative supply amount of mixed vapor, and MMH vapor was supplied while adjusting the pressure inside container 3 (concentration estimation pressure adjustment) based on the estimated value so that the MMH concentration in the mixed gas was 7.8%, and the above-mentioned film formation test was performed.

[0067] In Comparative Example 3, a concentration estimation was performed according to the cumulative supply amount of mixed vapor, and regardless of the estimated value, MMH vapor was supplied while maintaining the pressure inside the vessel 3 at 80 kPa (i.e., without concentration control), and the above-mentioned film formation test was performed.

[0068] Table 4 shows the MMH concentration in the mixed gas and the amount of film formation per cycle of ALD in Example 7 and Comparative Example 3. In Example 7, even when the cumulative supply amount of mixed vapor exceeded 900 g, MMH vapor with a stable concentration could be supplied, and the amount of film formation per cycle was 0.50 nm. In Comparative Example 3, the MMH concentration in the mixed gas decreased as the cumulative supply amount of mixed vapor increased, and when the cumulative supply amount of mixed vapor reached 900 g, the amount of film formation per cycle decreased significantly. In addition, when the cumulative supply amount of mixed vapor exceeded 800 g, the amount of film formation per cycle decreased each time the film formation process was performed. From the comparison between Example 7 and Comparative Example 3, it can be seen that even when the liquid mixture is not a solution but a liquid mixture, it is preferable to adjust the concentration-estimated pressure according to the cumulative supply amount of mixed vapor.

[0069] [Table 4] [Explanation of symbols]

[0070] 1 Steam supply device 2 Liquid mixture 3 containers 4. Introduction route 5. Supply Target 6 Supply Channel 7. Remaining amount measuring device 8. Concentration control device 9 Temperature regulator 10 Pressure Regulator 11 Processing equipment 12 Thermometer 13 Second substance removal device

Claims

1. a container containing a liquid mixture including a first substance and a second substance having a lower saturated vapor pressure than the first substance; an introduction path for introducing a carrier gas into the container; a supply path for supplying a mixed gas of the vapor of the liquid mixture and the carrier gas from the container to a supply target; a remaining amount measuring device for measuring the remaining amount of the liquid mixture in the container; a concentration control device that performs concentration control to suppress a decrease in the concentration of the first substance in the mixed gas caused by exhausting the vapor of the liquid mixture from the container by controlling the pressure, temperature, or both inside the container, The concentration control device performs the concentration control in accordance with the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device.

2. The steam supply device according to claim 1 , wherein the remaining amount measuring device is constituted by a weight meter or a liquid level meter.

3. 2. The vapor supply device according to claim 1, wherein the concentration control device performs the concentration control in accordance with an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device.

4. 4. The steam supply device according to claim 3, wherein the concentration control device estimates the concentration of the first substance in the remaining amount of the liquid mixture in the container based on the initial amount of the liquid mixture in the container, the initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container measured by the remaining amount measuring device, and performs the concentration control based on the estimation result.

5. 5. The steam supply device according to claim 4, wherein the concentration control device adjusts the concentration of the first substance in the mixed gas to a preset target value in accordance with the estimated result of the concentration of the first substance in the remaining amount of the liquid mixture in the container.

6. A vapor supply method for supplying a mixed gas of vapor of the liquid mixture and the carrier gas from a container to a supply target, the method comprising: introducing a carrier gas into a container containing a liquid mixture including a first substance and a second substance having a saturated vapor pressure lower than that of the first substance; A vapor supply method, comprising: controlling the pressure, temperature, or both within the container in accordance with the remaining amount of the liquid mixture in the container measured by a remaining amount measuring device, thereby performing concentration control to suppress a decrease in the concentration of the first substance in the mixed gas associated with the discharge of the vapor of the liquid mixture from the container.

7. 7. The method of claim 6, wherein the remaining amount of the liquid mixture in the vessel is obtained by measuring weight or liquid level.

8. The steam supply method according to claim 6, wherein the concentration control is performed according to an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container.

9. 9. The steam supply method according to claim 8, further comprising estimating a concentration of the first substance in the remaining amount of the liquid mixture in the container based on an initial amount of the liquid mixture in the container, an initial concentration of the first substance in the liquid mixture in the container, and the remaining amount of the liquid mixture in the container, and performing the concentration control based on a result of the estimation.

10. 10. The steam supply method according to claim 9, wherein the concentration control adjusts the concentration of the first substance in the mixed gas to a preset target value in accordance with the estimated result of the concentration of the first substance in the remaining amount of the liquid mixture in the container.

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