Film forming method using atomic layer deposition method

Abstract

The present invention relates to a method for producing a thin film, which uses an atomic layer deposition method and comprises a step for vaporizing a starting material liquid containing a starting material compound in an evaporator; a step for introducing the vaporized starting material compound into a film formation chamber; and a step for forming a thin film on the substrate. The method for manufacturing the thin film includes a step for discharging a gas phase portion of the evaporator.

Description

Technical Field

[0001] The present invention relates to a film forming method using an atomic layer deposition method. Background Art

[0002] Atomic layer deposition (hereinafter also referred to as “ALD”) is known as a method for forming films on various substrates. In film formation processes using ALD, a metal complex is generally used as a raw material.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-36068 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] In ALD, organometallic compounds are used as raw materials, but their low volatility and vapor pressure can pose a problem. To increase the vapor pressure of organometallic compounds, one approach is to raise the heating temperature during volatilization. However, while increasing the heating temperature increases the vapor pressure of the organometallic compound, it also causes decomposition, albeit minimally. The resulting decomposition products can mix into the raw material as impurities, causing the vapor pressure of the raw material compound in the evaporator to become unstable. Furthermore, there is a risk that the decomposition products will be incorporated into the film.

[0008] An object of the present invention is to provide an atomic layer deposition method capable of stable film formation.

[0009] Technical solutions to technical problems

[0010] The present invention includes the following embodiments.

[0011] [1] A method for producing a thin film using atomic layer deposition, comprising: vaporizing a raw material liquid containing a raw material compound in an evaporator;

[0012] The step of introducing the raw material compound vaporized in the above step into the film forming chamber;

[0013] The process of forming a thin film on a substrate,

[0014] The thin film production method includes the step of discharging the gas phase portion of the evaporator.

[0015] [2] The method for producing a thin film according to [1] above, further comprising the step of moving the raw material liquid in the evaporator to increase the contact area with the gas phase.

[0016] [3] The method for producing a thin film according to [2] above, wherein the movement of the raw material liquid is generated by stirring by a stirring mechanism.

[0017] [4] The method for producing a thin film according to [2] or [3] above, wherein the contact area between the raw material liquid and the gas phase is 1.1 times or more relative to the contact area when there is no movement.

[0018] [5] The method for producing a thin film according to any one of [1] to [4] above, wherein the temperature of the raw material liquid in the evaporator is 400° C. or lower.

[0019] [6] A method for manufacturing a thin film according to any one of [1] to [5] above, wherein the partial pressure of the raw material compound in the portion connecting the evaporator and the film-forming chamber is substantially the same as the partial pressure of the raw material compound in the evaporator.

[0020] [7] The method for producing a thin film according to any one of [1] to [6] above, wherein the raw material compound is a metal carbonyl complex, a metallocene complex or an amidine metal complex.

[0021] [8] The method for producing a thin film according to [7] above, wherein the metal is Co or W.

[0022] [9] The method for producing a thin film according to any one of [1] to [8] above, wherein the raw material compound is

[0023]

[0024]

[10] The method for producing a thin film according to any one of [1] to [9] above, wherein the gas phase contains decomposition products of the raw material compound.

[0025]

[11] The method for producing a thin film according to any one of [1] to

[10] above, wherein the substrate is a copper substrate.

[0026]

[12] The method for producing a thin film according to any one of [1] to

[11] , comprising:

[0027] Step A: vaporizing a raw material liquid containing a raw material compound in an evaporator;

[0028] Step B: introducing the vaporized raw material compound in the evaporator into the film forming chamber;

[0029] Step C: introducing a reactive gas into the film forming chamber; and

[0030] Step D: Discharge the gas phase from the evaporator.

[0031] This thin film production method performs the following cycle: while performing step A, step B and then step C are performed, and step D is performed between step B and the next step B.

[0032]

[13] The method for producing a thin film according to any one of [1] to

[12] , comprising:

[0033] Step (i): introducing a raw material compound into a film forming chamber to deposit the raw material compound on a substrate to form a raw material compound film;

[0034] Step (ii): discharging the raw material compound remaining in the film forming chamber;

[0035] Step (iii): introducing a reactive gas into the film forming chamber to react the raw material compound deposited on the substrate with the reactive gas to reduce the raw material compound and form a film;

[0036] Step (iv): Exhausting the unreacted reactive gas and by-product gas in the film forming chamber.

[0037]

[14] The method for producing a thin film according to any one of [1] to

[13] above, comprising:

[0038] Step A: vaporizing a raw material liquid containing a raw material compound in an evaporator;

[0039] Step B: introducing the vaporized raw material compound in the evaporator into the film forming chamber;

[0040] Step C: introducing a reactive gas into the film forming chamber; and

[0041] Step D: Discharge the gas phase from the evaporator.

[0042] The thin film manufacturing method performs the following cycle: while performing step A, step B and then step C, step D is performed between step B and the next step B.

[0043] The above raw material compound is

[0044]

[0045] The film manufacturing method includes the steps of stirring the raw material liquid in the evaporator by a stirring mechanism to increase the contact area with the gas phase.

[0046] The temperature of the raw material liquid in the above evaporator is below 350°C.

[0047] The gas phase contains decomposition products of the raw material compound.

[0048] The above-mentioned substrate is a copper substrate.

[0049]

[15] A film forming device comprising:

[0050] Evaporators that vaporize raw material liquid containing raw material compounds,

[0051] A discharge mechanism for discharging the gas phase in the evaporator, and

[0052] A film deposition chamber that forms films on substrates using atomic layer deposition.

[0053]

[16] The film forming apparatus according to

[15] above, wherein the evaporator includes a motion mechanism for moving the raw material liquid containing the raw material compound.

[0054]

[17] The film forming device according to

[15] or

[16] above, wherein the motion mechanism is a stirring mechanism.

[0055]

[18] The film forming apparatus according to any one of

[15] to

[17] above, wherein the temperature of the raw material liquid in the evaporator is 400° C. or lower.

[0056]

[19] A film forming device according to any one of

[15] to

[18] above, further comprising a connection portion connecting the evaporator and the film forming chamber, wherein the partial pressure of the raw material compound in the evaporator is substantially the same as the partial pressure of the raw material compound in the evaporator.

[0057] Effects of the Invention

[0058] According to the method of the present invention, stable film formation can be achieved by utilizing ARD. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of an example of a film forming apparatus of the present invention.

[0060] Figure 2 Schematic diagram of the evaporation rate of the raw material compounds in the examples.

[0061] Figure 3 Schematic diagram of the curve of the evaporation rate of the raw material compound in the comparative example. DETAILED DESCRIPTION

[0062] It should be noted that the film forming method and film forming apparatus described below are examples for specifically illustrating the technical concept of the present invention, and unless otherwise stated, the invention in this specification is not limited to the following contents.

[0063] The method for manufacturing a thin film of the present invention is characterized in that it includes: a process of vaporizing a raw material liquid containing a raw material compound in an evaporator, a process of introducing the raw material compound vaporized in the above process into a film forming chamber to form a film on a substrate, and also includes a process of discharging the gas phase portion in the above evaporator.

[0064] The thin film manufacturing method of the present invention can be implemented using the film forming apparatus of the present invention. The film forming apparatus of the present invention comprises: an evaporator for vaporizing a raw material liquid containing a raw material compound; an exhaust mechanism for exhausting the gas phase in the evaporator; and a film forming chamber for forming a film on a substrate. The evaporator is equipped with a motion mechanism for moving the raw material liquid containing the raw material compound.

[0065] One embodiment of the film forming apparatus of the present invention is shown in FIG. Figure 1 . The film forming device of the present invention has an evaporator 1 and a film forming chamber 2, and the evaporator 1 is provided with a stirrer (motion mechanism) 3. The film forming chamber 2 is provided with a film forming table 4. The evaporator 1 is connected to the film forming chamber 2 through a main pipe (connecting portion) 5. A pipe 9 for discharging the gas after film formation is connected to the film forming chamber 2. A pipe 6 for supplying a reactive gas and a pipe 7 for supplying a carrier gas are connected to the main pipe 5. Moreover, the main pipe 5 and the pipe 9 are connected by a pipe (discharge mechanism) 8. The pipe 8 can bypass the main pipe 5 and the pipe 9 and discharge the gaseous phase gas in the evaporator 1 to the outside of the film forming device without passing through the film forming chamber 2. There is a raw material liquid 15 containing a raw material compound in the evaporator 1. The raw material compound that has been vaporized in the evaporator is mixed with the reactive gas supplied by the pipe 6 and the carrier gas supplied by the pipe 7 through the main pipe 5 and is transported to the film forming chamber 2. After the reaction, various gases are discharged from the film forming chamber 2 through the pipe 9. On the other hand, the gas phase of the evaporator 1 can also be discharged from the pipeline 9 via the pipeline 8 without passing through the film forming chamber 2. A pump 11 is provided at the portion of the main pipeline 5 close to the evaporator 1. A pump 12 is provided at the portion of the pipeline 9 close to the film forming chamber 2, and a pump 13 is provided at a position of the pipeline 9 closer to the downstream than the connection portion with the pipeline 8. The main pipeline 5 is provided with valves 21 and 22 for adjusting the gas flow rate. The pipeline 6 is provided with valves 23 and 24 for adjusting the gas flow rate. The pipeline 8 is provided with a valve 25 for adjusting the gas flow rate. The pipeline 7 is provided with a mass flow controller (hereinafter also referred to as "MFC") 26 for adjusting the gas flow rate.

[0066] (Process A)

[0067] The film forming method of the present invention includes a step of vaporizing a raw material liquid containing a raw material compound in an evaporator (hereinafter also referred to as "step A").

[0068] The above-mentioned raw material compound is an organometallic compound.

[0069] Examples of the metal atom in the organometallic compound include transition metals such as cobalt, nickel, copper, vanadium, niobium, tantalum, chromium, molybdenum, and tungsten.

[0070] In a preferred embodiment, the metal atom is cobalt or tungsten. By using cobalt or tungsten as the metal atom, it is possible to prevent the copper wiring from being disconnected when a film has already been formed on the copper wiring.

[0071] Examples of the organic ligand in the organometallic compound include alkyl, alkenyl, cycloalkyl, aryl, alkynyl, alkylimino, amino, dialkylaminoalkyl, monoalkylamino, dialkylamino, diamine, di(silyl-alkyl)amino, di(alkyl-silyl)amino, disilylamino, alkoxy, alkoxyalkyl, hydrazide, phosphide, nitrile, dialkylaminoalkoxy, alkoxyalkyldialkylamino, siloxy, diketonate, cyclopentadienyl, silyl, pyrazolate, guanidine, phosphoguanidine, amidine, phosphoamidine, ketoiminate, diketeneiminate, and carbonyl groups.

[0072] In a preferred embodiment, the organic ligand is a carbonyl group, a cyclopentadienyl group or an amidine salt.

[0073] In a preferred embodiment, the organometallic compound is

[0074]

[0075] The above-mentioned raw material compounds may be used alone or in combination of two or more.

[0076] The above-mentioned raw material compounds are vaporized in the evaporator 1 .

[0077] The above-mentioned raw material liquid may contain impurities.

[0078] Examples of the impurities include decomposition products generated by decomposition of the raw material compounds, water, and the like.

[0079] In a preferred embodiment, the raw material liquid consists essentially of a raw material compound.

[0080] Although Figure 1 Only one evaporator 1 is shown in FIG. 3 , but for example, when two or more raw material compounds are used, two or more evaporators may be used.

[0081] The evaporator 1 includes a motion mechanism 3. The motion mechanism 3 is a mechanism for moving the raw material liquid in the evaporator 1. This movement increases the contact area between the raw material liquid and the gas phase in the evaporator 1.

[0082] By moving the raw material liquid in the evaporator, the contact area with the gas phase is increased, thereby accelerating the evaporation rate of the raw material liquid and raising the partial pressure of the raw material compound in the gas phase within the evaporator. This means that the raw material compound can quickly reach saturation vapor pressure in the gas phase within the evaporator. By shortening the time it takes to reach saturation vapor pressure, ALD enables stable film formation. Furthermore, the time between film formation cycles can be shortened, increasing the film formation rate.

[0083] The motion mechanism 3 is not particularly limited as long as it can move the raw material liquid. For example, a stirring mechanism, a vibration mechanism, etc. can be cited as the motion mechanism.

[0084] Examples of the stirring mechanism include a method of rotating a stirring member in a liquid, a method of rotating a container itself, and a method of spraying a raw material compound into a liquid.

[0085] In a preferred embodiment, the stirring mechanism is a mechanism in which a stirring member is inserted into the liquid and rotated. Examples of such a stirring member include paddle-type, turbine-type, and ribbon-type stirrers.

[0086] Examples of the vibration mechanism include a method of vibrating liquid by irradiating ultrasonic waves and a method of vibrating the container itself.

[0087] The contact area between the raw material liquid and the gas phase in the evaporator is preferably 1.1 times or greater, more preferably 1.5 times or greater, even more preferably 2.0 times or greater, and even more preferably 3.0 times or greater, compared to when the raw material liquid is not moving. Increasing this contact area can increase the evaporation rate of the raw material liquid. The contact area can preferably be 100 times or less, and more preferably 50 times or less, compared to when the raw material liquid is not moving.

[0088] The contact area between the raw material liquid and the gas phase can be calculated by simulation using fluid analysis software.

[0089] In the film-forming method of the present invention, the rapid evaporation rate of the raw material liquid allows the temperature within the evaporator and the raw material liquid to be kept relatively low. The raw material liquid temperature within the evaporator 1 is preferably 400°C or lower, more preferably 350°C or lower. This relatively low temperature suppresses the decomposition of unnecessary raw material compounds and prevents the incorporation of impurities into the formed film. Furthermore, energy efficiency is excellent. The raw material liquid temperature can be, for example, 150°C or higher, preferably 200°C or higher.

[0090] The raw material compound may be heated by heating the evaporator externally with a heater or by heating the evaporator internally with a heater or the like. Alternatively, as another method, the raw material liquid may be heated by blowing a heated medium such as a carrier gas into the raw material liquid, or the raw material liquid heated externally may be introduced into the evaporator.

[0091] The gas pressure inside the evaporator 1 may be 100 Pa to 1.5 kPa.

[0092] (Process B)

[0093] The film forming method of the present invention includes a step of introducing the raw material compound vaporized in the above-mentioned step A into a film forming chamber (hereinafter also referred to as "step B").

[0094] The raw material compound introduced into the film forming chamber is deposited on the substrate arranged in the film forming chamber to form a raw material compound film.

[0095] The gas of the raw material compound generated in the evaporator 1 is transported to the film forming chamber 2 through the main pipe 5. The gas of the raw material compound remaining in the film forming chamber 2 is discharged from the pipe 9 to the outside of the system.

[0096] The main pipe 5 may have a valve for regulating the pressure inside the evaporator 1 or regulating the flow rate of the raw material compound to the film forming chamber 2. Figure 1 In the embodiment shown, the main pipe 5 has valves 21 and 22 .

[0097] A pipeline for conveying a carrier gas, a pipeline for conveying a reactive gas, etc. may also be connected to the main pipe 5. Figure 1 In the illustrated embodiment, a pipeline 6 for conveying a reactive gas and a pipeline 7 for conveying a carrier gas are connected to the main pipe 5 .

[0098] The pipeline 7 may also have a mechanism for controlling the flow rate of the carrier gas. The pipeline 7 may have a mass flow controller for controlling the flow rate of the carrier gas. Figure 1 In the embodiment shown, the line 7 has a mass flow controller 26. Figure 1 In the embodiment shown, the raw material compound gas and the carrier gas are mixed in the main pipe 5. It should be noted that Figure 1 In the embodiment, the line 7 is connected to the main pipe 5, but it can also be connected to the evaporator 1, in which the starting compound is mixed with the carrier gas.

[0099] Examples of the carrier gas include inert gases such as nitrogen and noble gases, and nitrogen or argon is preferably used.

[0100] The main pipe 5 may include a heating mechanism. The heating mechanism may be a heater disposed around the pipe, typically a jacket heater.

[0101] The heating temperature is preferably set to a temperature such that the partial pressure of the raw material compound in the evaporator 1 is substantially equal to the partial pressure of the raw material compound in the portion connecting the evaporator 1 and the film forming chamber 2 (i.e., the main pipe 5). By making the partial pressure of the raw material compound in the evaporator 1 and the main pipe 5 substantially equal, film formation control is facilitated and the quality of the resulting film is improved.

[0102] The fact that the partial pressure of the raw material compound in the evaporator 1 is substantially the same as the partial pressure of the raw material compound in the portion connecting the evaporator 1 and the film forming chamber 2 (i.e., the main pipe 5) means that the difference between the partial pressures is within 50 Pa. The difference between the partial pressure of the raw material compound in the evaporator 1 and the partial pressure of the raw material compound in the portion connecting the evaporator 1 and the film forming chamber 2 (i.e., the main pipe 5) is preferably within 30 Pa, more preferably within 10 Pa, and even more preferably within 5 Pa.

[0103] (Process C)

[0104] The film formation method of the present invention may include a step of introducing a reactive gas into the film formation chamber (hereinafter also referred to as “step C”).

[0105] The reactive gas introduced into the film forming chamber reacts with the raw material compound deposited on the substrate to reduce the raw material compound, thereby forming a metal film on the substrate.

[0106] The reactive gas is introduced into the film forming chamber 2 through the main pipe 5 via the pipe 6. After the reaction occurs in the film forming chamber 2, the reactive gas is discharged to the outside of the system via the pipe 9.

[0107] The pipeline 6 may have a mechanism for controlling the flow of the reactive gas. Figure 1 In the embodiment shown, the pipeline 6 has valves 23 and 24 for controlling the flow of the reactive gas. Figure 1 In the embodiment shown, the reactive gas and the carrier gas are mixed in the main pipe 5. It should be noted that Figure 1 In the figure, the pipeline 7 is connected to the main pipe 5, but it can also be connected to the film forming chamber 2 to directly introduce the reactive gas into the film forming chamber 2.

[0108] (Process D)

[0109] The film forming method of the present invention may include a step of removing the gas phase portion of the evaporator (hereinafter also referred to as "step D").

[0110] While the raw material liquid gas generated within evaporator 1 is not exhausted outside of evaporator 1, the concentration of impurities such as decomposition products of the raw material compound, particularly low-boiling-point components, increases within evaporator 1, ultimately increasing the concentration of these decomposition products within the raw material liquid. In this state, the vapor pressure of the raw material compound becomes unstable, making stable film formation difficult. Furthermore, the likelihood of impurities incorporating into the film increases. By removing the vapor phase from the evaporator in step D, the impurity concentration within evaporator 1 can be reduced, stabilizing the vapor pressure of the raw material compound and enabling stable film formation. Furthermore, the incorporation of impurities into the film can be suppressed.

[0111] exist Figure 1 In the embodiment, the gas phase of the evaporator 1 contains impurities. The gas phase containing impurities is discharged to the outside of the system through the pipe 8 connected to the main pipe 5.

[0112] The pipe 8 bypasses the main pipe 5 and the pipe 9. This allows the gas in the evaporator 1 to be discharged outside the film forming apparatus without passing through the film forming chamber 2. The pipe 8 has a valve 25 for opening and closing the gas discharge.

[0113] Step D is performed before step B. Specifically, step D is performed before step B within 1 minute, preferably within 30 seconds, more preferably within 20 seconds, and even more preferably within 10 seconds.

[0114] Step D may be performed simultaneously with step C or separately. When step D and step C are performed simultaneously, only part of step D or step C may be performed simultaneously with the other step.

[0115] In a preferred embodiment, the film production method of the present invention performs the following cycle: performing step A, step B, and then step C, and performing step D between step B and the next step B. Step D and step C may be performed simultaneously.

[0116] Next, the reaction in the film forming chamber 2 is described. First, (i) the raw material compound is introduced into the film forming chamber 2 as described above, thereby depositing the raw material compound on the substrate to form a raw material compound film. Then, (ii) the raw material compound gas remaining in the film forming chamber 2 is discharged. Then, (iii) a reactive gas is introduced into the film forming chamber 2, thereby causing the raw material compound deposited on the substrate to react with the reactive gas, reducing the raw material compound to form a film, usually a metal film. Then, (iv) the unreacted reactive gas and by-product gas are discharged. The desired monatomic film is obtained by the above (i) to (iv). In addition, a film of the desired thickness is formed by repeatedly implementing steps (i) to (iv).

[0117] (Process (i))

[0118] In step (i), a raw material compound is introduced and deposited on a substrate to form a raw material compound film.

[0119] The substrate is usually placed on a film forming table provided in the film forming chamber 2 before the raw material compound is introduced.

[0120] The materials constituting the above-mentioned substrate may include, but are not particularly limited to, metals such as copper, silver, gold, platinum, nickel, palladium, and aluminum; silicon; ceramics such as indium arsenide, indium gallium arsenide, silicon oxide, silicon nitride, silicon carbide, titanium nitride, tantalum oxide, tantalum nitride, titanium oxide, titanium nitride, ruthenium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, and gallium nitride; glass, etc.

[0121] In one embodiment, the material constituting the substrate is copper, silver, gold, platinum, nickel, palladium or aluminum, preferably copper.

[0122] The shape of the substrate may be, but is not particularly limited to, a plate, a rod, a sphere, a layer, a fiber, a scale, or the like.

[0123] In one embodiment, the base material may be in the form of a layer disposed on a substrate, for example, a wiring on a circuit board.

[0124] The temperature of the substrate when the raw material compound is deposited on the substrate may be, for example, 20 to 600°C, preferably 50 to 500°C, more preferably 100 to 450°C, and even more preferably 100 to 400°C.

[0125] (Step (ii))

[0126] In step (ii), the gaseous raw material compound remaining in the film forming chamber 2 is discharged.

[0127] Examples of the exhaust method include a method of purging the system with an inert gas such as nitrogen or argon, a method of exhausting the system by reducing the pressure, or a combination of the two.

[0128] (Process (iii))

[0129] In step (iii), a reactive gas is introduced into the film forming chamber 2 so that the raw material compound deposited on the substrate reacts with the reactive gas to reduce the raw material compound, thereby forming a metal film.

[0130] The reactive gas is not particularly limited as long as it can react with the raw material compound, and examples thereof include hydrogen, oxygen, formic acid, hydrogen chloride, hydrogen bromide, hydrogen iodide, monochlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, boron trichloride, boron tribromide, methyl iodide, and methyl bromide.

[0131] The substrate temperature when the reactive gas is introduced into the film forming chamber 2 may be, for example, 20 to 600°C, preferably 50 to 500°C, more preferably 100 to 450°C, and even more preferably 100 to 400°C.

[0132] (Process (iv))

[0133] In step (iv), unreacted reactive gas and by-product gas are exhausted.

[0134] Examples of the exhaust method include a method of purging the system with an inert gas such as nitrogen or argon, a method of exhausting the system by reducing the pressure, or a combination of the two.

[0135] The gas exhausted in step (ii) and step (iv) is exhausted through the pipeline 9. The pipeline 9 may have an exhaust valve for adjusting the exhaust flow rate or for adjusting the pressure of the film forming chamber 2.

[0136] As described above, the above steps (i) to (iv) form one cycle and can be repeated multiple times depending on the desired film thickness.

[0137] As mentioned above, although one embodiment of the present invention has been described, the present invention is not limited to this embodiment, and various modifications can be made.

[0138] Example

[0139] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to the following Examples.

[0140] As shown below, using Figure 1 The device shown has thin films formed using atomic layer deposition.

[0141] The process conditions are as follows.

[0142] Raw material compound: (3,3-dimethyl-1-butyne) dicobalt hexacarbonyl:

[0143]

[0144] Raw material compound gas flow rate: 0.003 scc (Standard Cubic Sentimeters: standard milliliters per minute) / cycle × 5 cycles

[0145] Reactive gas: hydrogen

[0146] Reactive gas flow rate: 14 scc / cycle × 3 cycles

[0147] Carrier gas: nitrogen

[0148] Carrier gas flow rate: 5ccpm

[0149] Evaporator set temperature: 70℃

[0150] Film forming chamber set temperature: 200℃

[0151] <General Process>

[0152] The raw material liquid compound is heated at a set temperature while stirring. Simultaneously, the film formation chamber is heated to the set temperature. Carrier gas is supplied by a mass flow controller at a set flow rate (5 sccm). Valve 25 is opened for 10 seconds to remove the vapor phase from the evaporator. Valve 25 is then closed.

[0153] <Example Process>

[0154] After the above general process, the following steps are performed.

[0155] (1) Repeat the following process 5 times.

[0156] Open valve 21 → Close valve 21 after 1 second → Open valve 22 after 0.75 seconds → Close valve 22 after 1 second.

[0157] (2) Open valve 25 0.25 seconds after (1) is executed, and close valve 25 2 seconds after.

[0158] (3) Repeat the following process 3 times after 2 seconds of executing (1).

[0159] Open valve 23 → Close valve 23 after 1 second → Open valve 24 after 0.75 seconds → Close valve 24 after 1 second

[0160] (4) Execute (3) for 5 seconds and then return to (1).

[0161] <Comparative Example Process>

[0162] (1) Repeat the following process 5 times.

[0163] Open valve 21 → Close valve 21 after 1 second → Open valve 22 after 0.75 seconds → Close valve 22 after 1 second

[0164] (2) Repeat the following process 3 times after 2 seconds of (1).

[0165] Open valve 23 → Close valve 23 after 1 second → Open valve 24 after 0.75 seconds → Close valve 24 after 1 second.

[0166] (3) Return to (1) again after 5 seconds from (2).

[0167] The pressure change in the evaporator during the above process was measured. The results of the example are shown in Figure 2 The results of the comparative example are shown in Figure 3 .

[0168] Figure 2 The small fluctuations near the saturated vapor pressure in the figure are pressure fluctuations during the pulse supply in Example process (1). After the pulse supply is completed, the pressure is evacuated to about 100 Pa in Example process (2) to remove impurities generated by thermal decomposition. Then, by providing a raw material stirring mechanism, the raw material is rapidly evaporated. After the reactive gas is supplied in Example process (3), the raw material vapor pressure is restored to near the saturated vapor pressure. When the raw material is pulsed again in Example process (4), it can be supplied at a constant pressure. The results confirm that a stable ALD process can be performed in this way.

[0169] On the other hand, in the comparative example process, although the raw material is quickly evaporated by the stirring mechanism, the decomposition products are accumulated in the container because the impurities are not removed by vacuuming. Figure 3 As shown, the pressure inside the container significantly exceeded the saturated vapor pressure, and the pressure during the pulsed supply of the raw material (the portion with minimal fluctuations) continued to rise with each cycle. This meant that the raw material could no longer be supplied at a constant pressure, and the proportion of impurities in the raw material continued to rise, making it impossible to perform a stable ALD process.

[0170] Industrial Applicability

[0171] According to the film forming method of the present invention, a high-purity thin film can be formed efficiently. Therefore, the film forming method of the present invention can be used in various applications, such as the production of circuit boards.

[0172] Explanation of symbols

[0173] 1: Evaporator; 2: Film-forming chamber; 3: Agitator; 4: Film-forming table; 5: Main pipe (piping); 6: Pipeline; 7: Pipeline; 8: Pipeline; 9: Pipeline; 11: Pump; 12: Pump; 13: Pump; 15: Raw material liquid; 21, 22: Valve; 23, 24: Valve; 25: Valve; 26: Mass flow controller.

Claims

1. A method for producing a thin film, characterized in that: The thin film manufacturing method utilizes atomic layer deposition, which includes: The process of vaporizing the raw material liquid containing the raw material compound in an evaporator, The process of introducing the raw material compound vaporized in the above process into the film forming chamber, The process of forming a thin film on a substrate, The thin film manufacturing method includes the step of discharging the gas phase portion of the evaporator.

2. The method for producing a thin film according to claim 1, wherein: The method includes the step of moving the raw material liquid in the evaporator to increase the contact area with the gas phase.

3. The method for producing a thin film according to claim 2, wherein: The movement of the raw material liquid is generated by stirring of the stirring mechanism.

4. The method for producing a thin film according to claim 2, wherein: The contact area between the raw material liquid and the gas phase is 1.1 times or more the contact area when there is no movement.

5. The method for producing a thin film according to claim 1, wherein: The temperature of the raw material liquid in the evaporator is 400° C. or lower.

6. The method for producing a thin film according to claim 1, wherein: The partial pressure of the raw material compound in a portion connecting the evaporator and the film-forming chamber is substantially the same as the partial pressure of the raw material compound in the evaporator.

7. The method for producing a thin film according to claim 1, wherein: The raw material compound is a metal carbonyl complex, a metallocene complex or an amidine metal complex.

8. The method for producing a thin film according to claim 7, wherein: The metal is Co or W.

9. The method for producing a thin film according to claim 1, wherein: The raw material compound is 10. The method for producing a thin film according to claim 1, wherein: The gas phase contains decomposition products of the raw material compound.

11. The method for producing a thin film according to claim 1, wherein: The substrate is a copper substrate.

12. The method for producing a thin film according to claim 1, wherein: include: Step A: vaporizing a raw material liquid containing a raw material compound in an evaporator; Step B: introducing the vaporized raw material compound in the evaporator into the film forming chamber; Step C: introducing a reactive gas into the film forming chamber; and Step D: Discharging the gas phase of the evaporator, The thin film manufacturing method performs the following cycle: while performing step A, step B and then step C are performed, and step D is performed between step B and the next step B.

13. The method for producing a thin film according to claim 1, wherein: include: Step (i): introducing a raw material compound into a film forming chamber to deposit the raw material compound on a substrate to form a raw material compound film; Step (ii): discharging the raw material compound remaining in the film forming chamber; Step (iii): introducing a reactive gas into the film forming chamber to react the raw material compound deposited on the substrate with the reactive gas to reduce the raw material compound and form a film; Step (iv): Exhausting the unreacted reactive gas and by-product gas in the film forming chamber.

14. The method for producing a thin film according to claim 1, wherein: include: Step A: vaporizing a raw material liquid containing a raw material compound in an evaporator; Step B: introducing the vaporized raw material compound in the evaporator into the film forming chamber; Step C: introducing a reactive gas into the film forming chamber; and Step D: Discharging the gas phase of the evaporator, The film manufacturing method performs the following cycle: performing step A, performing step B and then step C, and performing step D between step B and the next step B. The raw material compound is The thin film manufacturing method includes the steps of stirring the raw material liquid in the evaporator by a stirring mechanism to increase the contact area with the gas phase. The temperature of the raw material liquid in the evaporator is below 350°C. The gas phase contains decomposition products of the raw material compound, The substrate is a copper substrate.

15. A film forming device, characterized in that: have: Evaporators that vaporize raw material liquid containing raw material compounds, a discharge mechanism for discharging the gas phase in the evaporator, and A film deposition chamber that forms films on substrates using atomic layer deposition.

16. The film forming apparatus according to claim 15, wherein: The evaporator includes a motion mechanism for moving the raw material liquid containing the raw material compound.

17. The film forming apparatus according to claim 15, wherein: The motion mechanism is a stirring mechanism.

18. The film forming apparatus according to claim 15, wherein: The temperature of the raw material liquid in the evaporator is 400° C. or lower.

19. The film forming apparatus according to claim 15, wherein: The film forming chamber further includes a connection portion connecting the evaporator and the film forming chamber, wherein the partial pressure of the raw material compound in the evaporator is substantially the same as the partial pressure of the raw material compound in the evaporator.

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