Gas supply method and gas supply apparatus
A stepwise temperature control process efficiently removes impurities from solid materials, ensuring a high-purity gas supply for film formation by vaporizing and purifying the material gas in a controlled manner.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NIPPON SANSO CORP
- Filing Date
- 2023-11-17
- Publication Date
- 2026-07-16
AI Technical Summary
Existing gas supply methods for film formation fail to efficiently remove impurities from solid materials, which can contaminate the film formation process.
A stepwise temperature control process is implemented within a container to vaporize and remove impurities from solid materials, including multiple temperature stages and holding times, followed by a controlled discharge and supply of the purified material gas to the film formation chamber.
This method effectively removes impurities, ensuring a high-purity material gas supply for film formation, thereby enhancing the efficiency and purity of the film formation process.
Smart Images
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Abstract
Description
Technical Field
[0006] , , ,
[0007] , ,
[0001] The present invention relates to a gas supply method and a gas supply device.
Background Art
[0002] As a pretreatment method for solid materials generated by vaporizing a material gas for film formation, there is known a method having an impurity removal step of discharging exhaust gas containing impurity gas generated by vaporizing impurities of solid materials in a container from the container through a discharge line (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] As a gas supply method and a gas supply device for supplying a material gas for film formation to a film formation chamber, there is no known method capable of efficiently removing impurities of solid materials.
[0005] Therefore, an object of the present invention is to provide a gas supply method and a gas supply device capable of efficiently removing impurities of solid materials.
Means for Solving the Problems
[0008] [2] The gas supply method according to [1], wherein the first temperature range includes a first reference temperature set within the range of 100 to 200°C.
[0009] [3] The gas supply method according to [2], wherein the first temperature step is performed over at least a first holding time set in the range of 10 to 60 minutes.
[0010] [4] The gas supply method according to [3], wherein the first temperature step is terminated after the first holding time has elapsed when the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the first reference temperature.
[0011] [5] The above-mentioned second temperature range includes a second reference temperature, The gas supply method according to any one of [2] to [4], wherein the second reference temperature is set such that the vapor pressure of the material gas at the second reference temperature is 10 to 25% of that at the first reference temperature.
[0012] [6] The gas supply method according to [5], wherein the second temperature step is performed over a second holding time set in the range of 10 to 60 minutes.
[0013] [7] The gas supply method according to [6], wherein the second temperature stage ends when the pressure in the container becomes equal to or lower than the vapor pressure of the material gas at the second reference temperature after the lapse of the second holding time.
[0014] [8] The gas supply method according to any one of [5] to [7], wherein the upper limit of the second temperature range is lower than the lower limit of the first temperature range.
[0015] [9] The impurity removal step includes a third temperature stage of maintaining the inside of the container at a third temperature range, and a second temperature increase stage of increasing the temperature inside the container stepwise from the third temperature stage to the second temperature stage. The third temperature range includes a third reference temperature. The gas supply method according to any one of [5] to [8], wherein the third reference temperature is set such that the value of the vapor pressure of the material gas at the third reference temperature is 1 to 5% of that at the first reference temperature.
[0016]
[10] The gas supply method according to [9], wherein the third temperature stage is performed for at least a third holding time set within a range of 10 to 60 minutes.
[0017]
[11] The gas supply method according to
[10] , wherein the third temperature stage ends when the pressure in the container becomes equal to or lower than the vapor pressure of the material gas at the third reference temperature after the lapse of the third holding time.
[0018]
[12] The gas supply method according to any one of [9] to
[11] , wherein the upper limit of the third temperature range is lower than the lower limit of the second temperature range.
[0019]
[13] The impurity removal step includes a fourth temperature stage of maintaining the inside of the container at a fourth temperature range, and a third temperature increase stage of increasing the temperature inside the container stepwise from the fourth temperature stage to the third temperature stage. The fourth temperature range includes a fourth reference temperature. The fourth reference temperature is set to room temperature, and the gas supply method according to any one of [9] to
[12] .
[0020]
[14] The fourth temperature stage is performed over at least a fourth holding time set within the range of 10 to 60 minutes, and the gas supply method according to
[13] .
[0021]
[15] The fourth temperature stage ends when the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the fourth reference temperature after the fourth holding time has elapsed, and the gas supply method according to
[14] .
[0022]
[16] The upper limit of the fourth temperature range is lower than the lower limit of the third temperature range, and the gas supply method according to any one of
[13] to
[15] .
[0023]
[17] The value of the vapor pressure of the material gas at the fourth reference temperature is less than 1% of that at the first reference temperature, and the gas supply method according to any one of
[13] to
[16] .
[0024]
[18] In each temperature stage of the impurity removal process, the discharge flow rate of the vaporized gas generated by the vaporization of the solid material inside the container is 100 to 1000 sccm, and the gas supply method according to any one of [1] to
[17] .
[0025]
[19] The gas supply process starts after the end of the first temperature stage, and the gas supply method according to any one of [1] to
[18] .
[0026]
[20] The main component of the solid material is molybdenum(IV) dichloride oxide (MoO2Cl2), and the gas supply method according to any one of [1] to
[19] .
[0027]
[21] The gas supply method according to any one of [1] to
[20] , wherein the temperature inside the container is the temperature of the solid material inside the container.
[0028] [twenty two] A gas supply method according to any one of [1] to
[21] , using a gas supply device comprising the container, a heating device for raising the temperature inside the container, a discharge line having a discharge line opening / closing section consisting of at least one discharge line gate valve, a vacuum pump provided on the discharge line, a discharge line flow rate adjustment section provided on the discharge line, a supply line having a supply line opening / closing section consisting of at least one supply line gate valve, and a control unit for controlling the heating device, the discharge line opening / closing section, the vacuum pump, the discharge line flow rate adjustment section, and the supply line opening / closing section.
[0029] [twenty three] The system comprises the container, a heating device for raising the temperature inside the container, a discharge line having a discharge line opening / closing section consisting of at least one discharge line gate valve, a vacuum pump provided on the discharge line, a discharge line flow rate adjustment section provided on the discharge line, a supply line having a supply line opening / closing section consisting of at least one supply line gate valve, and a control unit that controls the heating device, the discharge line opening / closing section, the vacuum pump, the discharge line flow rate adjustment section, and the supply line opening / closing section. The control unit can perform the gas supply method described in any one of items [1] to
[21] , A gas supply device in which the control unit can operate in a stepwise impurity removal mode, controlling the heating device, the discharge line opening / closing unit, the vacuum pump, the discharge line flow rate adjustment unit, and the supply line opening / closing unit to sequentially perform each of the temperature steps of the impurity removal process. [Effects of the Invention]
[0030] According to the present invention, it is possible to provide a gas supply method and a gas supply apparatus that can efficiently remove impurities from solid materials. [Brief explanation of the drawing]
[0031] [Figure 1] This is a piping diagram showing an example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 2] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 3] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 4] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 5] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 6] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 7] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 8] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 9] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 10] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 11] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 12] This is a piping diagram showing another example of a gas supply device used in a gas supply method according to one embodiment of the present invention. [Figure 13] This is a cross-sectional view showing an example of a container and heating device used in a gas supply method according to one embodiment of the present invention. [Figure 14]This is a cross-sectional view showing another example of a container and heating device used in a gas supply method according to one embodiment of the present invention. [Modes for carrying out the invention]
[0032] Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0033] In one embodiment of the present invention, the gas supply method includes an impurity removal step of discharging an exhaust gas containing impurity gas generated by the vaporization of impurities in a solid material M (see Figure 13) within a container 2 through an exhaust line 5 (see Figure 1) from within the container 2, and a gas supply step of supplying a supply gas containing a material gas for film formation generated by the vaporization of the main components of the solid material M excluding impurities within the container 2 through a supply line 9 (see Figure 1) from within the container 2 to a film formation chamber. The impurity removal step includes a first temperature step of maintaining the temperature inside the container 2 within a first temperature range, a second temperature step of maintaining the temperature inside the container 2 within a second temperature range, and a first temperature rise step of raising the temperature inside the container 2 in a stepped manner from the second temperature step to the first temperature step.
[0034] According to the above configuration, in the impurity removal process, by performing stepwise impurity removal in the second temperature stage and the first temperature stage, efficient impurity removal can be achieved while suppressing the reduction of the main component of the solid material M. Therefore, in the gas supply process, vaporized gas consisting of high-purity material gas for film formation with few impurity components can be efficiently supplied to film formation chambers for semiconductor manufacturing and the like.
[0035] The first temperature range includes a first reference temperature set within the range of 100 to 200°C. According to the above configuration, the efficiency of impurity removal by the impurity removal process can be increased. The first reference temperature is more preferably 110 to 190°C, more preferably 120 to 180°C, more preferably 130 to 170°C, and more preferably 140 to 160°C.
[0036] The first temperature step is performed for at least a first holding time set within the range of 10 to 60 minutes. According to the above configuration, the efficiency of impurity removal by the impurity removal step can be increased. The first holding time is more preferably 10 to 50 minutes, more preferably 15 to 45 minutes, more preferably 20 to 40 minutes, and more preferably 25 to 35 minutes.
[0037] The first temperature stage ends when, after the first holding time has elapsed, the pressure inside container 2 falls below the vapor pressure of the material gas at the first reference temperature. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0038] The second temperature range includes a second reference temperature, which is set such that the vapor pressure of the material gas at the second reference temperature is 10-25% of that at the first reference temperature. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0039] The second temperature step is performed for at least a second holding time set within the range of 10 to 60 minutes. According to the above configuration, the efficiency of impurity removal by the impurity removal step can be increased. The second holding time is more preferably 10 to 50 minutes, more preferably 15 to 45 minutes, more preferably 20 to 40 minutes, and more preferably 25 to 35 minutes.
[0040] The second temperature stage ends when, after the second holding time has elapsed, the pressure inside container 2 falls below the vapor pressure of the material gas at the second reference temperature. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0041] The upper limit of the second temperature range is lower than the lower limit of the first temperature range. According to the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0042] The impurity removal process includes a third temperature stage in which the temperature inside container 2 is maintained within a third temperature range, and a second temperature increase stage in which the temperature inside container 2 is raised in steps from the third temperature stage to the second temperature stage. The third temperature range includes a third reference temperature, and the third reference temperature is set such that the vapor pressure of the material gas at the third reference temperature is 1-5% of that at the first reference temperature. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased.
[0043] The third temperature step is performed for at least a third holding time set within the range of 10 to 60 minutes. According to the above configuration, the efficiency of impurity removal by the impurity removal step can be increased. The third holding time is more preferably 10 to 50 minutes, more preferably 15 to 45 minutes, more preferably 20 to 40 minutes, and more preferably 25 to 35 minutes.
[0044] The third temperature stage ends when, after the third holding time has elapsed, the pressure inside container 2 falls below the vapor pressure of the material gas at the third reference temperature. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0045] The upper limit of the third temperature range is lower than the lower limit of the second temperature range. According to the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0046] The impurity removal process includes a fourth temperature step in which the temperature inside container 2 is maintained within a fourth temperature range, and a third temperature increase step in which the temperature inside container 2 is raised in steps from the fourth temperature step to the third temperature step. The fourth temperature range includes a fourth reference temperature, which is set to room temperature. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased.
[0047] The fourth temperature step is performed for at least a fourth holding time set within the range of 10 to 60 minutes. According to the above configuration, the efficiency of impurity removal by the impurity removal step can be increased. The fourth holding time is more preferably 10 to 50 minutes, more preferably 15 to 45 minutes, more preferably 20 to 40 minutes, and more preferably 25 to 35 minutes.
[0048] The fourth temperature step ends when, after the fourth holding time has elapsed, the pressure inside container 2 falls below the vapor pressure of the material gas at the fourth reference temperature. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0049] The upper limit of the fourth temperature range is lower than the lower limit of the third temperature range. According to the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0050] The vapor pressure of the material gas at the fourth reference temperature is less than 1% of that at the first reference temperature. According to the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0051] The fourth temperature step may be performed if the vapor pressure of the material gas at the fourth reference temperature is less than 1% of that at the first reference temperature, and the fourth temperature step may not be performed if the vapor pressure of the material gas at the fourth reference temperature is 1% or more of that at the first reference temperature. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased.
[0052] At each temperature stage of the impurity removal process, the discharge flow rate of the vaporized gas produced by the vaporization of the solid material M in the container 2 is 100 to 1000 sccm. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased. The above discharge flow rate is more preferably 100 to 900 sccm, more preferably 100 to 800 sccm, more preferably 100 to 700 sccm, more preferably 100 to 600 sccm, more preferably 100 to 500 sccm, and more preferably 200 to 400 sccm.
[0053] In the first temperature step of the impurity removal process, the first temperature range is set to, for example, within ±10°C, more preferably within ±5°C, and more preferably within ±1°C relative to the first reference temperature. In the second temperature step of the impurity removal process, the second temperature range is set to, for example, within ±10°C, more preferably within ±5°C, and more preferably within ±1°C relative to the second reference temperature. In the third temperature step of the impurity removal process, the third temperature range is set to, for example, within ±10°C, more preferably within ±5°C, and more preferably within ±1°C relative to the third reference temperature. In the fourth temperature step of the impurity removal process, the fourth temperature range is set to, for example, within ±10°C, more preferably within ±5°C, and more preferably within ±1°C relative to the fourth reference temperature.
[0054] The gas supply process begins after the completion of the first temperature stage. This configuration allows for increased efficiency in removing impurities during the impurity removal process.
[0055] The solid material M is a material that becomes solid at room temperature and atmospheric pressure, i.e., 25°C and 1 atmosphere. With the above configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0056] The main component of the solid material M is molybdenum(IV) dichloride oxide (MoO2Cl2). This configuration allows for increased efficiency in the impurity removal process.
[0057] The main component of the solid material M is not limited to molybdenum(IV) dichloride oxide, but may also be inorganic metal chlorides and inorganic metal oxychlorides such as germanium, gallium, aluminum, hafnium, tungsten, and molybdenum.
[0058] The temperature inside container 2 may be the temperature of the solid material M inside container 2. With this configuration, the efficiency of impurity removal in the impurity removal process can be increased.
[0059] The gas supply method of this embodiment uses a gas supply device 1, as shown in Figure 1, which includes a container 2, a heating device 3 for raising the temperature inside the container 2, a discharge line 5 having a discharge line opening / closing section 4 consisting of at least one discharge line gate valve 4a, a vacuum pump 6 provided on the discharge line 5, a discharge line flow rate adjustment section 7 provided on the discharge line 5, a supply line 9 having a supply line opening / closing section 8 consisting of at least one supply line gate valve 8a, and a control unit (see Figure 13) that controls the heating device 3, the discharge line opening / closing section 4, the vacuum pump 6, the discharge line flow rate adjustment section 7, and the supply line opening / closing section 8. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased. The control unit is configured as a computer or the like.
[0060] The control unit may be configured to operate in a stepwise impurity removal mode, controlling the heating device 3, discharge line opening / closing unit 4, vacuum pump 6, discharge line flow rate adjustment unit 7, and supply line opening / closing unit 8 to sequentially perform each temperature step of the impurity removal process. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased.
[0061] The discharge line flow rate adjustment unit 7 is located on the primary side of the vacuum pump 6. With the above configuration, the efficiency of impurity removal by the impurity removal process can be increased.
[0062] As shown in Figure 1, the discharge line flow rate adjustment unit 7 is composed of a mass flow controller 7a, such as a mass flow controller (MFC), installed on the discharge line 5. This configuration simplifies the structure of the discharge line flow rate adjustment unit 7.
[0063] As shown in Figure 3, the discharge line flow rate adjustment unit 7 may be composed of a mass flow controller 7a provided on the discharge line 5, a bypass line opening / closing unit 10 consisting of at least one bypass line gate valve 10a, and a bypass line 7b that bypasses the mass flow controller 7a. With the above configuration, the flow rate of exhaust gas passing through the discharge line flow rate adjustment unit 7 can be appropriately controlled by controlling the mass flow controller 7a and the bypass line opening / closing unit 10 with the control unit.
[0064] As shown in Figure 5, the discharge line flow rate adjustment unit 7 is composed of an orifice 7c provided on the discharge line 5. With this configuration, the structure of the discharge line flow rate adjustment unit 7 can be simplified.
[0065] As shown in Figure 7, the discharge line flow rate adjustment unit 7 may be composed of an orifice 7c provided on the discharge line 5 and a bypass line opening / closing unit 10 consisting of at least one bypass line gate valve 10a, and a bypass line 7b that bypasses the orifice 7c. With the above configuration, the flow rate of exhaust gas passing through the discharge line flow rate adjustment unit 7 can be appropriately controlled by controlling the orifice 7c and the bypass line opening / closing unit 10 with the control unit.
[0066] As shown in Figure 9, the discharge line flow rate adjustment unit 7 is composed of a back pressure valve 7d provided on the discharge line 5. With this configuration, the structure of the discharge line flow rate adjustment unit 7 can be simplified.
[0067] As shown in Figure 11, the discharge line flow rate adjustment unit 7 may be configured with a back pressure valve 7d provided on the discharge line 5 and a bypass line opening / closing unit 10 consisting of at least one bypass line gate valve 10a, and a bypass line 7b that bypasses the back pressure valve 7d. With the above configuration, the flow rate of exhaust gas passing through the discharge line flow rate adjustment unit 7 can be appropriately controlled by controlling the back pressure valve 7d and the bypass line opening / closing unit 10 with the control unit.
[0068] The impurity removal process may be configured to discharge the exhaust gas, which contains impurity gas generated by the vaporization of impurities in the solid material M within the container 2, together with a carrier gas introduced into the container 2, through the discharge line 5 from within the container 2. With this configuration, the exhaust gas can be efficiently discharged using the carrier gas.
[0069] For the use of the carrier gas as described above, the gas supply device 1 has an introduction line 11 for introducing the carrier gas into the container 2, as shown in Figure 2 (an example in which the discharge line flow rate adjustment section 7 is composed of a mass flow controller 7a), Figure 4 (an example in which the discharge line flow rate adjustment section 7 is composed of a mass flow controller 7a and a bypass line 7b), Figure 6 (an example in which the discharge line flow rate adjustment section 7 is composed of an orifice 7c), Figure 8 (an example in which the discharge line flow rate adjustment section 7 is composed of an orifice 7c and a bypass line 7b), Figure 10 (an example in which the discharge line flow rate adjustment section 7 is composed of a back pressure valve 7d), and Figure 12 (an example in which the discharge line flow rate adjustment section 7 is composed of a back pressure valve 7d and a bypass line 7b). The introduction line 11 has an introduction line opening / closing section 12 consisting of at least one introduction line gate valve 12a, and the introduction line opening / closing section 12 may be controlled by a control unit.
[0070] The introduction line 11 may be configured to include an introduction line flow rate adjustment unit 13 on the introduction line 11. According to the above configuration, the exhaust efficiency of the exhaust gas by the carrier gas can be improved. The introduction line flow rate adjustment unit 13 can be configured, for example, by a mass flow controller 7a.
[0071] The gas supply device 1 may have a configuration in which multiple containers 2 are detachably connected in parallel to the discharge line 5 and the supply line 9 (and to the introduction line 11 if an introduction line 11 is present). With the above configuration, the supply of gas can be continued without stopping the impurity removal process and the gas supply process even when a container 2 is replaced. In this case, multiple heating devices 3 may be provided to correspond to each container 2, or a common heating device 3 may be used to heat multiple containers 2.
[0072] The heating device 3 may be configured to heat the solid material M inside the container 2 by heating the container 2 itself, or it may be configured to directly heat the solid material M inside the container 2.
[0073] As shown in Figure 13, the heating device 3 may be configured to have a bottom heating section 3a that heats the bottom of the container 2. With this configuration, the solid material M, whose solid portion is reduced by vaporization during the impurity removal process, can be efficiently heated while being brought into close contact with the bottom heating section 3a by its own weight. In order to further improve the thermal efficiency by increasing the surface area of the heat transfer section, as shown in Figure 14, a protruding section 2a that protrudes upward from the bottom of the container 2 may be provided, and the bottom heating section 3a may be configured to heat the solid material M via the protruding section 2a. The control device 17 may be configured to have a first temperature controller 17a that feedback controls the temperature of the heating device 3 (preferably the bottom heating section 3a as shown in Figure 13) (for example by PID control) (see dashed arrow in Figure 13) so that the temperature of the solid material M in the container 2 (preferably the lower part or lower end of the solid material M as shown in Figure 13) approaches the target temperature (see dashed arrow in Figure 13). With this configuration, the temperature of the solid material M in the container 2 can be accurately controlled, so the efficiency of impurity removal by the impurity removal process can be further increased. In that case, as shown in Figure 13, a first temperature sensor 18a (e.g., a thermocouple) may be provided to measure the temperature of the solid material M inside the container 2 and send the measured value to the first temperature controller 17a, and a second temperature sensor 18b (e.g., a thermocouple) may be provided to measure the temperature of the heating device 3 (bottom heating section 3a) and send the measured value to the first temperature controller 17a. If the second temperature sensor 18b detects an abnormal rise in temperature of the heating device 3 (bottom heating section 3a), the first temperature controller 17a may send a stop signal (see the dashed arrow in Figure 13) to the heating device 3 (bottom heating section 3a) to stop it.
[0074] The temperature inside the container 2 may be configured to use the temperature of the container 2 itself, rather than the temperature of the solid material M inside the container 2. In this case, the control device 17 may have a first temperature controller 17a that provides feedback control to bring the temperature of the bottom heating section 3a closer to the target temperature. Alternatively, the control device 17 may have a second temperature controller 17b that provides feedback control (see dashed arrow in Figure 13) to bring the temperature of the body heating section 3b of the heating device 3 that heats the body of the container 2 closer to the target temperature. In this case, as shown in Figure 13, a third temperature sensor 18c (e.g., a thermocouple) may be provided that measures the temperature of the body heating section 3b and sends the measured value to the second temperature controller 17b.
[0075] As shown in Figure 1, the gas supply device 1 has a purge line 14 that introduces purge gas into the discharge line 5 and the supply line 9, and the purge line 14 has a purge line opening / closing section 15 consisting of at least one purge line gate valve 15a. The purge line opening / closing section 15 is controlled by a control unit. With the above configuration, the discharge line 5 and the supply line 9 can be purified by the purge gas at an appropriate timing.
[0076] The purge line 14 has a purge line flow rate adjustment unit 16 on the purge line 14. With the above configuration, the purification efficiency by the purge gas can be improved. The purge line flow rate adjustment unit 16 can be made up of, for example, a mass flow controller 7a.
[0077] The present invention is not limited to the embodiments described above, and can be modified in various ways without departing from its essence.
[0078] Therefore, the gas supply method of the embodiment described above can be modified as long as it is a gas supply method having: an impurity removal step of discharging an exhaust gas containing impurity gas generated by the vaporization of impurities in the solid material M within the container 2 through an exhaust line 5 from inside the container 2; and a supply gas containing a material gas for film formation generated by the vaporization of the main components of the solid material M excluding impurities within the container 2 through a supply line 9 from inside the container 2. The impurity removal step has a first temperature step of maintaining the temperature inside the container 2 within a first temperature range, a second temperature step of maintaining the temperature inside the container 2 within a second temperature range, and a first temperature rise step of raising the temperature inside the container 2 in a stepped manner from the second temperature step to the first temperature step. [Examples]
[0079] An impurity removal process was performed using the gas supply device 1 shown in Figure 1, following the fourth, third, second, and first temperature stages in that order. The main component of the solid material was molybdenum(IV) dichloride oxide. For each temperature stage, (1) the reference temperature for that temperature stage, (2) the vapor pressure of the material gas at the reference temperature for that temperature stage, (3) the ratio of (2) to the vapor pressure of the material gas at the first reference temperature, (4) the holding time for that temperature stage, and (5) the discharge flow rate of the vaporized gas at that temperature stage were as shown in the following table.
[0080] [Table 1]
[0081] As a result, the concentration of metal impurities in the solid material measured by ICP-MS (inductively coupled plasma mass spectrometer) and the remaining amount of molybdenum(IV) dichloride oxide, the main component of the solid material, measured by a weighing scale, are shown in the following table. This confirmed that highly efficient impurity removal could be achieved, limiting the consumption of the main component in the solid material to 2%.
[0082] [Table 2] [Explanation of Symbols]
[0083] 1. Gas supply device 2 containers 3 Heating device 3a Bottom heating section 3b Torso heating section 4. Discharge line opening / closing section 4a Discharge line gate valve 5. Discharge line 6. Vacuum pump 7. Discharge line flow rate adjustment section 7a Mass flow controller 7b Detour Line 7c orifice 7d back pressure valve 8. Supply line switching section 8a Supply line gate valve 9. Supply Line 10 Bypass line opening / closing section 10a Bypass line gate valve 11. Introduction Line 12. Inlet line opening / closing section 12a Inlet line gate valve 13. Flow rate adjustment section of the introduction line 14 Purge Line 15. Purge line opening / closing section 15a Purge line gate valve 16. Purge line flow rate adjustment section 17 Control device 17a 1st temperature controller 17b Second temperature controller 18a First temperature sensor 18b Second temperature sensor 18°C Third Temperature Sensor M solid material
Claims
1. An impurity removal step involves discharging an exhaust gas containing impurity gas, which is generated by the vaporization of impurities in solid materials within the container, from the container through a discharge line. The system includes a gas supply step of supplying a supply gas containing a material gas for film formation, which is generated by vaporizing the main components of the solid material excluding impurities within the container, to the film formation chamber through a supply line from within the container, A vacuum pump and a discharge line flow rate adjustment unit are provided on the aforementioned discharge line. The impurity removal step includes a first temperature step of maintaining the temperature inside the container within a first temperature range, a second temperature step of maintaining the temperature inside the container within a second temperature range, and a first temperature rise step of raising the temperature inside the container from the second temperature range to the first temperature range in a stepped manner from the end of the second temperature step to the start of the first temperature step. The above-mentioned first temperature range includes a first reference temperature, The first temperature step is performed for at least the first holding time. The first temperature step ends when, after the first holding time has elapsed, the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the first reference temperature. The aforementioned second temperature range includes a second reference temperature, The second temperature step is performed for at least the second holding time. The second temperature step ends when, after the second holding time has elapsed, the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the second reference temperature. A gas supply method wherein, at each of the temperature stages of the impurity removal step, the discharge flow rate of the vaporized gas generated by the vaporization of the solid material in the container is adjusted to a predetermined discharge flow rate by the discharge line flow rate adjustment unit.
2. The gas supply method according to claim 1, wherein the first reference temperature is set within the range of 100 to 200°C.
3. The gas supply method according to claim 1, wherein the first holding time is set within the range of 10 to 60 minutes.
4. The gas supply method according to claim 1, wherein the second reference temperature is set such that the vapor pressure of the material gas at the second reference temperature is 10 to 25% of that at the first reference temperature.
5. The gas supply method according to claim 1, wherein the second holding time is set within the range of 10 to 60 minutes.
6. The impurity removal step includes a third temperature step of maintaining the temperature inside the container within a third temperature range, and a second temperature rise step of raising the temperature inside the container from the third temperature range to the second temperature range in a stepped manner from the end of the third temperature step to the start of the second temperature step. The specified temperature range includes the third reference temperature. The third reference temperature is set such that the vapor pressure of the material gas at the third reference temperature is 1-5% of that at the first reference temperature. The third temperature step is performed for at least the third holding time. The gas supply method according to claim 1, wherein the third temperature step ends when the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the third reference temperature after the third holding time has elapsed.
7. The gas supply method according to claim 6, wherein the third holding time is set within the range of 10 to 60 minutes.
8. The impurity removal step includes a fourth temperature step of maintaining the inside of the container in a fourth temperature range, and a third temperature rise step of raising the temperature inside the container from the fourth temperature range to the third temperature range in a stepped manner from the end of the fourth temperature step to the start of the third temperature step. The fourth temperature range includes the fourth reference temperature. The aforementioned fourth reference temperature is set to room temperature. The fourth temperature step is performed for at least the fourth holding time. The gas supply method according to claim 6, wherein the fourth temperature step ends when the pressure inside the container becomes less than or equal to the vapor pressure of the material gas at the fourth reference temperature after the fourth holding time has elapsed.
9. The gas supply method according to claim 8, wherein the fourth holding time is set within the range of 10 to 60 minutes.
10. The main component of the solid material is molybdenum (IV) dichloride oxide (MoO ２ Cl ２ The gas supply method according to claim 1, wherein the gas supply method is as follows:
11. The gas supply method according to claim 1, wherein the temperature of the solid material inside the container is used as the temperature inside the container.
12. The system comprises the container, a heating device for raising the temperature inside the container, a discharge line having a discharge line opening / closing section consisting of at least one discharge line gate valve, a vacuum pump provided on the discharge line, a discharge line flow rate adjustment section provided on the discharge line, a supply line having a supply line opening / closing section consisting of at least one supply line gate valve, and a control unit that controls the heating device, the discharge line opening / closing section, the vacuum pump, the discharge line flow rate adjustment section, and the supply line opening / closing section. The control unit can perform the gas supply method described in any one of claims 1 to 11. A gas supply device in which the control unit can operate in a stepwise impurity removal mode, controlling the heating device, the discharge line opening / closing unit, the vacuum pump, the discharge line flow rate adjustment unit, and the supply line opening / closing unit to sequentially perform each of the temperature steps of the impurity removal process.