Atomic layer deposition apparatus and atomic layer deposition method

Abstract

To provide a technique that contributes to improvement in film formation efficiency and film formation accuracy in ALD.SOLUTION: A gas supply unit 4 for supplying gas into a chamber 3 capable of freely storing an object to be film-formed is assumed to have a raw gas supply line L2 for supplying raw material gas into a chamber 3, an ozone gas supply line L1 for supplying ozone gas of 80 vol.% or more into the chamber 3, and an inert gas supply line L3 for supplying inert gas into the chamber 3. The ozone gas supply line L1 includes: an ozone gas buffer unit L12 that stores and freely seals the ozone gas in the ozone gas supply line L1 by opening and closing an opening / closing valve V1 provided in the ozone gas supply line L1 and freely supplies the stored ozone gas in the chamber 3; and an ozone gas buffer unit pressure gauge PL1 for measuring gas pressure in the ozone gas buffer unit L12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an atomic layer deposition apparatus and an atomic layer deposition method, and relates to a technology for forming thin films applicable to, for example, semiconductor devices. [Background technology]

[0002] Typical methods for forming thin films of advanced devices such as semiconductor devices (e.g., CPU circuits) include evaporation, sputtering, chemical vapor deposition (CVD), and atomic layer deposition (ALD). Among these, ALD offers the best step coverage and density, making it an essential method for forming thin films of state-of-the-art devices (see, for example, Patent Document 1).

[0003] In ALD, four steps are repeatedly performed: evacuating the entire chamber (vacuum vessel, etc.) containing the object to be film-deposited (e.g., silicon wafer); introducing the ALD raw material gas (e.g., TMA (trimethylaluminum)) into the chamber; removing the raw material gas from the chamber; and supplying an oxidizer for the raw material gas (e.g., water vapor) into the chamber. By introducing the raw material gas into the chamber and filling it with the gas, one molecular layer of the raw material gas is adsorbed onto the surface of the object to be film-deposited (the film-deposited surface), forming a molecular layer of the raw material gas on the film-deposited surface of the object.

[0004] Then, by supplying an oxidizing agent for the raw material gas into the chamber, the molecular layer of the raw material gas formed on the film-forming surface is oxidized, and a molecular layer of oxide film (e.g., aluminum oxide) of the raw material gas is formed on the film-forming surface. By repeating the above four steps, a thin film with a thickness corresponding to the number of repetitions is formed.

[0005] The ALD (Automated Laser Deposition) process tends to involve high deposition temperatures. For example, to ensure sufficient reaction between TMA (Triangular Mass Acetate) and water vapor, the material to be deposited must be heated to a relatively high temperature (e.g., 300°C to 500°C). Furthermore, in the case of compound semiconductors such as GaN and ZnO used in state-of-the-art devices, several thin-film semiconductor layers with subtly different compositions may be formed on the deposition surface through heteroepitaxy or MBE (Molecular Beam Epitaxy). Because these thin-film semiconductor layers are susceptible to compositional shifts due to heating, deposition at low temperatures is strongly required.

[0006] Furthermore, in other cutting-edge devices, there is a preference for film deposition temperatures of room temperature to 100°C using ALD. Therefore, ALD methods that replace the oxidizing agent with ozone (O3) or plasma oxygen and utilize the radicals generated by these oxidizing agents are being investigated. Ozone can generate O radicals, which are a powerful oxidizing agent, through thermal decomposition, and thus enable lower temperatures, but even then, the object to be film-deposited still needed to be heated to several hundred degrees Celsius. Moreover, even when using plasma oxygen, which can supply O radicals from the outset and is considered to enable the lowest temperatures, the temperature is only around 100°C to 150°C, and further lower temperatures are desired.

[0007] Furthermore, conventional ALD film deposition processes tend to have low deposition efficiency due to factors such as long deposition times. For example, in order to deposit a single molecular layer on a surface using ALD, it is necessary to first adsorb a raw material gas onto the surface, remove the raw material gas, and then oxidize the raw material gas layer (adsorbed layer) formed on the surface. This process usually takes several minutes. For example, in the case of aluminum oxide, the thickness of one molecular layer is about 0.1 nm, so approximately 100 molecular layers are required to deposit a practical film of about 10 nm, which would take about 50 minutes even if each molecular layer is deposited in 30 seconds. For example, with other film deposition methods such as CVD, a film of about 10 nm can be deposited in less than one minute, so the long deposition time of ALD was a significant disadvantage compared to other film deposition methods.

[0008] In recent years, other methods have also been investigated, such as those that involve supplying various gases, including raw material gases and oxidizing agents, through a showerhead to form films by single-wafer processing, and those that use OH radicals generated by the reaction of ozone with unsaturated hydrocarbons as an oxidizing agent (for example, Patent Documents 2 and 3). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2014-057014 [Patent Document 2] Patent No. 6702514 [Patent Document 3] Patent No. 6677356 [Non-patent literature]

[0010] [Non-Patent Document 1] News Release 2018, “World’s First Technology to Create an Oxide Film at Room Temperature Using Pure Ozone,” [Online], July 31, 2019, Meidensha Corporation website, Internet, <https: / / www.meidensha.co.jp / news / news_03 / news_03_01 / 1227605_2469.html> [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In typical ALD applications, the radicals have a relatively short lifespan, making it difficult for them to diffuse widely within the chamber. This can make it difficult, for example, to oxidize the source gas adsorbed on an uneven film surface.

[0012] Therefore, the objects to be coated were limited to flat substrates or similar flat plates, or the process was limited to single-wafer coating. Furthermore, it may have been difficult to form oxide films with desired properties.

[0013] Due to the above trends, improvements in film formation efficiency and film formation accuracy (such as shortening the film formation time and improving the film quality of the oxide film) are required.

[0014] The present invention has been made in view of the above circumstances, and an object thereof is to provide a technology that contributes to the improvement of film formation efficiency and film formation accuracy.

Means for Solving the Problems

[0015] The atomic layer deposition apparatus and the atomic layer deposition method according to this invention can contribute to the solution of the above problems. As an aspect of the atomic layer deposition apparatus, it includes a chamber that can freely accommodate and remove the object to be film-formed, a gas supply unit that supplies gas into the chamber, and a gas discharge unit that sucks the gas in the chamber and discharges it outside the chamber to maintain a reduced pressure state in the chamber. The gas supply unit includes a raw material gas supply line having a raw material gas supply pipe capable of supplying raw material gas into the chamber, an ozone gas supply line having an ozone gas supply pipe capable of supplying ozone gas of 80% by volume or more into the chamber, and an inert gas supply line having an inert gas supply pipe capable of supplying inert gas into the chamber. The ozone gas supply line is characterized by including an ozone gas buffer unit that can accumulate and seal the ozone gas in the ozone gas supply pipe by opening and closing an on-off valve provided in the ozone gas supply pipe, and can supply the accumulated ozone gas into the chamber, and an ozone gas buffer unit pressure gauge that measures the gas pressure in the ozone gas buffer unit.

[0016] It may further be characterized by further including an ozone gas accumulation amount control unit that controls the accumulation amount of the ozone gas accumulated in the ozone gas buffer unit based on the change amount of the measured value of the ozone gas buffer unit pressure gauge.

[0017] It may also be characterized in that the volume in the ozone gas buffer unit is 1 / 50 or more of the volume in the chamber.

[0018] Also, the volume of the downstream side of the ozone gas buffer section in the ozone gas supply pipe may be in the range of 1 / 10 to 1 / 2 of the volume of the ozone gas buffer section.

[0019] Also, the downstream end portion of the ozone gas supply pipe is formed with an ozone gas nozzle portion protruding from the inner peripheral surface of the chamber, and the downstream end portion of the raw material gas supply pipe is formed with a raw material gas nozzle portion protruding from the inner peripheral surface of the chamber. Each of the ozone gas nozzle portion and the raw material gas nozzle portion may have a cylindrical portion protruding and extending from the inner peripheral surface of the chamber, a lid portion sealing the tip portion in the protruding direction of the cylindrical portion, and a plurality of nozzle holes penetrating the outer peripheral surface of the cylindrical portion in the radial direction of the cylindrical portion.

[0020] Also, the ozone gas nozzle portion and the raw material gas nozzle portion may protrude from the inner peripheral surface of the chamber so as to be parallel to each other, and the nozzle holes of the ozone gas nozzle portion and the nozzle holes of the raw material gas nozzle portion may be provided at positions facing each other.

[0021] Also, a heating portion inside the chamber for heating between both the ozone gas nozzle portion and the raw material gas nozzle portion in the chamber may be disposed between both of them, and the heating portion inside the chamber may be capable of heating between both of them in the chamber to a temperature higher than the temperature in the ozone gas supply pipe and the temperature in the raw material gas supply pipe.

[0022] Also, it may further include an inner peripheral surface temperature adjusting portion for adjusting the temperature of the inner peripheral surface of the chamber. The inner peripheral surface temperature adjusting portion can adjust the temperature of the inner peripheral surface of the chamber to a temperature higher than the temperature in the ozone gas supply pipe and the temperature in the raw material gas supply pipe. The ozone gas nozzle portion and the raw material gas nozzle portion may protrude from the inner peripheral surface of the chamber so as to be parallel to each other, and the nozzle holes of the ozone gas nozzle portion and the nozzle holes of the raw material gas nozzle portion may be provided at positions facing away from each other.

[0023] Furthermore, the inner circumferential surface of the chamber may be provided with a gas flow guide portion that protrudes from the inner circumferential surface of the chamber, and the gas flow guide portion may be characterized in that it extends from the inner circumferential surface of the chamber toward the position where the object to be filmed is located within the chamber.

[0024] Furthermore, the system may be characterized by having multiple raw gas supply lines arranged in parallel with the chamber.

[0025] Furthermore, the system may also be characterized by having a supply pipe temperature control unit that can adjust the temperature inside the supply pipes of each supply gas supply line.

[0026] Furthermore, the raw material gas supply line may be characterized by comprising a raw material gas buffer section that can store and seal the raw material gas in the raw material gas supply pipe by opening and closing an on-off valve provided in the raw material gas supply pipe, and can supply the stored raw material gas into the chamber, and a raw material gas buffer section pressure gauge for measuring the gas pressure in the raw material gas buffer section.

[0027] Furthermore, the system may also be characterized by further comprising a raw material gas storage amount control unit that controls the amount of raw material gas stored in the raw material gas buffer unit based on the change in the measured value of the raw material gas buffer unit pressure gauge.

[0028] Furthermore, the volume within the raw material gas buffer section may be characterized as being 1 / 500 or more of the volume within the chamber.

[0029] Furthermore, the volume of the raw material gas supply piping downstream of the raw material gas buffer section may be characterized as being within the range of 1 / 10 to 1 / 2 of the volume of the said raw material gas buffer section.

[0030] Furthermore, the raw material gas supply piping may be characterized by having a bypass line on the upstream and / or downstream side of the raw material gas buffer section, which has a bypass pipe that can switch between a connected state and a blocked state between the raw material gas buffer section and the gas discharge section.

[0031] Furthermore, the raw material gas supply line may be characterized by having an additional inert gas supply line that has an additional inert gas supply pipe capable of switching between a connected state and a blocked state between the raw material gas supply pipe and the inert gas supply pipe.

[0032] Furthermore, the raw material gas supply line may include an additional inert gas supply line having an additional inert gas supply pipe that can switch between a connected state and a blocked state between the raw material gas supply pipe and the inert gas supply pipe, and the raw material gas buffer section may be characterized in that it can store and seal a mixed gas, which is a mixture of the raw material gas in the raw material gas supply pipe and the inert gas supplied from the inert gas supply pipe to the raw material gas supply pipe via the additional inert gas supply pipe, by opening and closing an on-off valve provided in the raw material gas supply pipe, and can also supply the stored mixed gas into the chamber.

[0033] Furthermore, the system may also be characterized by the inclusion of an additional supply pipe temperature adjustment unit that can adjust the temperature inside the additional inert gas supply pipe to a higher temperature than the temperature inside the raw material gas supply pipe.

[0034] One embodiment of an atomic layer deposition method is a method for forming an oxide film on the surface of an object to be deposited in a chamber of an atomic layer deposition apparatus, characterized by comprising: a raw material gas supply step of supplying a raw material gas containing elements constituting the oxide film into the chamber to form an adsorption layer of the raw material gas on the surface to be deposited; a raw material gas purging step of removing excess raw material gas supplied in the raw material gas supply step and gas generated by the adsorption of the raw material gas onto the surface to be deposited from the surface to be deposited; an oxidizing agent supply step of supplying 80% by volume or more of ozone gas into the chamber to oxidize the adsorption layer formed on the surface to be deposited; and an oxidizing agent purging step of removing excess ozone gas supplied in the oxidizing agent supply step and gas generated by the oxidation of the adsorption layer from the surface to be deposited.

[0035] Another aspect of the atomic layer deposition method is a method for forming an oxide film on the surface of an object to be deposited in a chamber of the atomic layer deposition apparatus, comprising: a raw material gas supply step of supplying a mixed gas, which is a mixture of a raw material gas containing elements constituting the oxide film and an inert gas, into the chamber to form an adsorption layer on the surface of the object to be deposited by the raw material gas in the mixed gas; a raw material gas purging step of removing excess gas from the mixed gas supplied in the raw material gas supply step and gas generated by the adsorption of the raw material gas in the mixed gas onto the surface of the object to be deposited from the surface of the object to be deposited; and an oxidizing agent supply of 80% by volume or more of ozone gas into the chamber to oxidize the adsorption layer formed on the surface of the object to be deposited. The process comprises a process and an oxidant purging process for removing excess ozone gas supplied in the oxidant supply process and gas generated by oxidizing the adsorption layer from the film-forming surface, wherein the mixed gas in the raw material gas supply process is obtained by first performing a raw material gas storage process for storing and sealing raw material gas in the raw material gas buffer section until the pressure inside the raw material gas buffer section reaches a predetermined pressure, and a mixed gas storage process for obtaining the mixed gas by supplying inert gas to the raw material gas buffer section via an inert gas additional supply pipe until the pressure inside the raw material gas buffer section reaches a predetermined pressure higher than that in the raw material gas storage process, thereby storing and sealing the mixed gas in the raw material gas buffer section.

[0036] Furthermore, the partial pressure of the raw material gas in the mixed gas accumulated in the raw material gas buffer section by the mixed gas accumulation process may be set to 1000 Pa or less, and the concentration of the raw material gas in the mixed gas may be set to 30% or less based on the partial pressure ratio of the raw material gas and the inert gas in the mixed gas.

[0037] Furthermore, the raw material gas supply process may be characterized by completing the supply of the mixed gas accumulated in the raw material gas buffer section to the chamber within 1 second, and maintaining the pressure in the chamber within the range of 0.1 to 100 Pa.

[0038] Furthermore, the process may also be characterized by supplying an inert gas into the raw material gas supply piping after the raw material gas supply process, thereby replacing the gas remaining in the raw material gas supply piping with the inert gas.

[0039] Furthermore, the partial pressure of ozone gas accumulated in the ozone gas buffer section by the oxidizing agent supply process may be characterized by being 10,000 Pa or less.

[0040] Furthermore, the oxidizing agent supply process may be characterized by completing the supply of ozone gas accumulated in the ozone gas buffer section to the chamber within 1 second, and maintaining the pressure inside the chamber within the range of 10 to 1000 Pa.

[0041] Furthermore, the process may be characterized by supplying gas into the chamber via a raw material gas supply process and sealing it for a certain period of time, then exhausting the gas from the chamber via a raw material gas purging process, and supplying gas into the chamber via an oxidizer supply process and sealing it for a certain period of time, and then exhausting the gas from the chamber via an oxidizer purging process.

[0042] Furthermore, the raw material gas purging process and the oxidizer purging process may be characterized by repeatedly supplying inert gas into the chamber multiple times, and the amount of inert gas supplied multiple times is 10 times or more the amount of gas supplied into the chamber in the raw material gas supply process, or 10 times or more the amount of gas supplied into the chamber in the oxidizer supply process.

[0043] Furthermore, the sealing time of the gas supplied into the chamber by the raw material gas supply process and the sealing time of the gas supplied into the chamber by the oxidizer supply process may be characterized to be within the range of 1 to 1000 seconds.

[0044] Furthermore, the process may be characterized by performing multiple cycles of the raw material gas supply process, raw material gas purging process, oxidizer supply process, and oxidizer purging process, and ensuring that the raw material gas used in at least one of the raw material gas supply processes is different from the raw material gas used in the remaining processes.

[0045] Furthermore, the oxide film may be characterized by containing an adsorption layer of one of the following: Al2O3, HfO2, TiO2, ZnO, Ta2O3, Ga2O3, MoO3, RuO2, SiO2, ZrO2, or Y2O3. [Effects of the Invention]

[0046] As described above, the present invention can contribute to improving film deposition efficiency and accuracy. [Brief explanation of the drawing]

[0047] [Figure 1] A schematic diagram illustrating an example of an ALD apparatus according to the embodiment. [Figure 2] A schematic cross-sectional view illustrating an example of object 2 to be coated. [Figure 3] Diagram of the film formation process related to the formation of oxide film 21. [Figure 4] A schematic diagram of the reaction showing an example of oxide film 21 formation. This figure shows an example of pores formed in a shower head. [Figure 5] A diagram illustrating the pressure change characteristics over time to illustrate an example of a film deposition cycle using steps S1 to S4. [Figure 6] Various cross-sectional images illustrating the results of cross-sectional observation of the oxide film 21 according to Example 3. [Figure 7] A schematic diagram illustrating the configuration example of the gas nozzle sections 61 and 62 of the piping L11 and L21 according to Example 4 (a cross-sectional view of the cylindrical section 6a in the axial direction, viewed from the inside of the cylindrical section 6a). [Figure 8] A schematic diagram illustrating the configuration example of the gas nozzle sections 61 and 62 of the piping L11 and L21 according to Example 4 ((A) is a view of the inside of the chamber 3 from the side of the opening edge surface 22a of the object to be coated 2 (description of the opening edge surface 22a etc. is omitted), (B) is a view of the inside of the chamber 3 from the side of the lid 6b (the object to be coated 2 is shown in cross-section in the same way as in Figure 2)). [Figure 9]A schematic diagram illustrating an example of the heating configuration for each gas in Chamber 3 according to Example 5 ((A) and (B) are diagrams depicted similarly to Figure 8). [Figure 10] A schematic diagram illustrating an example of the heating configuration for each gas in Chamber 3 according to Example 6 ((A) and (B) are diagrams depicted similarly to Figure 8). [Modes for carrying out the invention]

[0048] The atomic layer deposition apparatus and atomic layer deposition method of the embodiment of the present invention (hereinafter appropriately referred to as ALD apparatus and ALD method) are completely different from conventional ALD methods (hereinafter appropriately referred to simply as conventional ALD methods) that, for example, use relatively high film deposition temperatures or radicals generated by oxidizing agents.

[0049] In other words, the ALD apparatus and ALD method of this embodiment include a chamber capable of freely accommodating an object to be filmed, a gas supply unit for supplying gas into the chamber, and a gas discharge unit for drawing in gas from the chamber and discharging it outside the chamber to maintain a reduced pressure state inside the chamber. The gas supply unit includes a raw material gas supply line having a raw material gas supply pipe capable of supplying raw material gas into the chamber, an ozone gas supply line having an ozone gas supply pipe capable of supplying 80 volume% or more of ozone gas into the chamber, and an inert gas supply line having an inert gas supply pipe capable of supplying inert gas into the chamber.

[0050] The ozone gas supply line is equipped with an ozone gas buffer section that can store and seal ozone gas in the ozone gas supply pipe by opening and closing an on-off valve provided in the ozone gas supply pipe, and can also supply the stored ozone gas into the chamber, and an ozone gas buffer section pressure gauge for measuring the gas pressure in the ozone gas buffer section.

[0051] According to such an embodiment, it becomes easy to widely diffuse ozone gas into the chamber. For example, it becomes possible to sufficiently oxidize the source gas adsorbed onto the uneven film-deposited surface.

[0052] Therefore, for example, even without heating the film-deposited object or using radicals as an oxidizing agent, it is possible to sufficiently oxidize the source gas adsorbed on the film-deposited surface, and it becomes possible to form an oxide film with a desired film quality. Further, for example, it is also possible to arrange a plurality of film-deposited objects in the chamber and form oxide films for each of the film-deposited surfaces in a batch process (such as a batch process using a chamber with a relatively large volume). Thereby, it becomes possible to contribute to the improvement of film-forming efficiency and film-forming accuracy.

[0053] In addition, since it is possible to supply ozone gas with a high concentration of 80% by volume or more, it is also possible to form an oxide film at a relatively low temperature (for example, 100°C or lower). Therefore, not only on a substrate with relatively high heat resistance such as a Si substrate, but also on a substrate or film formed of a synthetic resin with relatively low heat resistance, it is possible to appropriately form an oxide film.

[0054] The ALD apparatus and ALD method of this embodiment include a source gas supply line, an ozone gas supply line, and an inert gas supply line in the gas supply unit as described above. In the ozone gas buffer unit of the ozone gas supply line, it is only necessary to temporarily accumulate and seal the ozone gas and be able to supply the accumulated ozone gas into the chamber. It is possible to appropriately apply the common technical knowledge in various fields (for example, the film-forming fields such as ALD and CVD, the modification field, the chamber field, the ozone gas field, the supply line field, etc.), and appropriately refer to prior art documents and the like for design modification as necessary. An example thereof is shown in the following examples.

[0055] In the following examples, for example, detailed descriptions are appropriately omitted by citing the same reference numerals for the same contents.

[0056] ≪Examples≫ <Main configuration of ALD apparatus 11> Figure 1 shows a schematic diagram of an ALD apparatus 11 according to an embodiment. This ALD apparatus 11 mainly comprises a chamber (reaction vessel) 3 capable of freely accommodating an object to be coated 2, as shown in Figure 2 below, a gas supply unit 4 for supplying various gases into the chamber 3, and a gas discharge unit 5 for drawing in gas from the chamber 3 and discharging it outside the chamber 3. The object to be coated 2 housed in the chamber 3 can be appropriately supported by, for example, a support unit not shown in the figure.

[0057] Chamber 3 has an ozone gas outlet 31 for injecting ozone gas into Chamber 3, a raw material gas outlet 32 ​​for injecting raw material gas into Chamber 3, and an inert gas outlet 33 for injecting inert gas into Chamber 3. These outlets 31 to 33 are located, for example, in a position facing the object to be filmed 2 in Chamber 3 (a position on the upper side of Chamber 3 in Figure 1). Chamber 3 is also equipped with a pressure gauge P capable of measuring the gas pressure inside Chamber 3.

[0058] The gas supply unit 4 includes an ozone gas supply line L1 that supplies ozone gas (for example, 80% or more by volume of ozone gas) from the ozone gas generator G1 into the chamber 3 from the nozzle 31, a raw material gas supply line L2 that supplies raw material gas from the raw material gas supply unit G2 into the chamber 3 from the nozzle 32, and an inert gas supply line L3 that supplies inert gas from the inert gas supply unit G3 into the chamber 3 from the nozzle 33.

[0059] The gas discharge unit 5 is located, for example, at a distance from each of the outlets 31-33 in the chamber 3 (in Figure 1, at a location on the side of the chamber 3 as shown). This gas discharge unit 5 is configured to draw in gas from inside the chamber 3 and discharge it outside the chamber 3, thereby maintaining a reduced pressure state inside the chamber 3 (for example, a state in which the inside of the chamber 3 becomes a vacuum environment). In the case of the gas discharge unit 5 in Figure 1, it is configured to include an exhaust pipe 5a, an on-off valve 5b, a vacuum pump 5c, etc.

[0060] <Ozone gas supply line L1> The ozone gas supply line L1 connects the ozone gas generator G1 and the outlet 31 and includes an ozone gas supply pipe L11 capable of supplying ozone gas from the ozone gas generator G1. This pipe L11 includes an ozone gas on-off valve V1 (shown in Figure 1 as on-off valves V1a and V1b located upstream and downstream of the ozone gas buffer section L12 described later) that can switch the gas flow within the pipe L11 between a flow-allowed state (open state) and a flow-blocked state (closed state), and an ozone gas buffer section L12 that can store and seal the ozone gas in the pipe L11 (ozone gas located upstream of the chamber 3) by opening and closing the on-off valve V1, and can also supply the stored ozone gas into the chamber 3. Furthermore, the pipe L11 includes an ozone gas buffer section pressure gauge P capable of measuring the gas pressure within the ozone gas buffer section L12. L1 It is equipped with that.

[0061] The ozone gas buffer section L12 is not particularly limited as long as it can receive and store ozone gas flowing through the piping L11, seal it appropriately at a predetermined pressure, and appropriately supply the ozone gas at that predetermined pressure into the chamber 3. For example, the volume of the ozone gas buffer section L12 is approximately 1 / 50 or more of the volume of the chamber 3 (for example, if the volume of the chamber 3 is 50,000 cc, the volume of the ozone gas buffer section L12 is 1,000 cc), and the gas pressure inside the ozone gas buffer section L12 can be maintained at approximately 10,000 Pa or less.

[0062] Furthermore, the volume of the piping L11 downstream of the ozone gas buffer section L12 (for example, in Figure 1, the volume from the outlet of the ozone gas buffer section L12 to the nozzle 31; if there is an ozone gas nozzle section 61 described later, the volume including the ozone gas nozzle section 61) can be set as appropriate. One example of this is setting it to a range of 1 / 10 to 1 / 2 of the volume of the ozone gas buffer section L12.

[0063] The amount of ozone gas accumulated in the ozone gas buffer section L12 (the amount of ozone gas supplied into the chamber 3) is controlled, for example, by an ozone gas accumulation control unit (not shown) via a pressure gauge PL1 It is possible to control it based on the change in the measured value.

[0064] Various configurations can be applied to the on-off valve V1. One example is to provide on-off valves V1a and V1b on the upstream and downstream sides of the ozone gas buffer section L12, as shown in Figure 1, or to apply automatic valves to these on-off valves V1a and V1b.

[0065] In such an ozone gas supply line L1, for example, the on / off valve V1 is opened and closed as needed, and the gas pressure in the ozone gas buffer section L12 is measured by a pressure gauge P L1 By controlling the system appropriately based on this, ozone gas at a predetermined pressure and concentration can be accumulated in the ozone gas buffer section L12, and this ozone gas can be supplied into the chamber 3.

[0066] After supplying this ozone gas into chamber 3, any ozone gas remaining in the ozone gas buffer section L12 can be stored and used (and supplied again into chamber 3) in the ozone gas buffer section L12 along with new ozone gas from the ozone gas generator G1 during the next ozone gas storage operation.

[0067] <Raw material gas supply line L2> The raw material gas supply line L2 connects the raw material gas supply device G2 and the nozzle 32 and includes a raw material gas supply pipe L21 capable of supplying the raw material gas from the raw material gas supply device G2. This pipe L21 includes a raw material gas on-off valve V2 (shown in Figure 1 as on-off valves V2a to V2c located upstream or downstream of the raw material gas buffer section L22, which will be described later) that can switch the gas flow within the pipe L21 between a flow-allowed state (open state) and a flow-blocked state (closed state), and a raw material gas buffer section L22 that can store and seal the raw material gas in the raw material gas supply line L2 (raw material gas located upstream of the chamber 3) by opening and closing the on-off valve V2, and can also supply the stored raw material gas into the chamber 3.

[0068] Furthermore, the piping L21 is connected to a raw material gas buffer section pressure gauge P, which can measure the gas pressure within the raw material gas buffer section L22. L2 It is equipped with the following. In the case of piping L21 in Figure 1, it is also equipped with the bypass line L4 and the inert gas addition line L5, which will be described later.

[0069] The raw material gas buffer section L22 is not particularly limited as long as it can receive the raw material gas flowing through the piping L21 and store it appropriately at a predetermined pressure, and can appropriately supply the raw material gas at the predetermined pressure into the chamber 3. For example, the volume of the raw material gas buffer section L22 is set to about 1 / 500 or more of the volume of the chamber 3 (for example, if the volume of the chamber 3 is 50,000 cc, the volume of the raw material gas buffer section L22 is 100 cc), and the gas pressure in the raw material gas buffer section L22 can be maintained at about 100,000 Pa or less.

[0070] Furthermore, the volume of the piping L21 downstream of the raw material gas buffer section L22 (for example, in Figure 1, the volume from the outlet of the raw material gas buffer section L22 to the nozzle 32; if there is a raw material gas nozzle section 62 described later, the volume including the raw material gas nozzle section 62) can be set as appropriate. One example of this is setting it to a range of 1 / 10 to 1 / 2 of the volume of the raw material gas buffer section L22.

[0071] The amount of raw material gas stored in the raw material gas buffer section L22 (the amount of raw material gas supplied into the chamber 3) is controlled, for example, by a raw material gas storage control unit (not shown) via a pressure gauge P L2 It is possible to control based on the change in the measured value of the pressure gauge P before and after the supply of raw material gas to chamber 3. L2 One method involves calculating and controlling the amount of raw material gas accumulated based on the change in the measured value and the volume of the raw material gas buffer section L22.

[0072] Various configurations can be applied to the on-off valve V2. One example is to appropriately install on-off valves V2a to V2c on the upstream and downstream sides of the raw material gas buffer section L22, as shown in Figure 1, or to apply high-speed on-off valves that can be controlled at high speed and with precision to these on-off valves V2a to V2c. In the case of on-off valve V2b in Figure 1, it has a three-way valve structure in order to connect the inert gas addition line L5, which will be described later.

[0073] In such a raw material gas supply line L2, for example, the on / off valve V2 is opened and closed as needed, and the gas pressure in the raw material gas buffer section L22 is measured by a pressure gauge P L2 By controlling accordingly based on this, it becomes possible to accumulate raw material gas at a predetermined pressure and concentration in the raw material gas buffer section L22 and supply that raw material gas into the chamber 3.

[0074] After supplying this raw material gas into chamber 3, any remaining raw material gas in the raw material gas buffer section L22 can be stored and used (re-supplied into chamber 3) in the raw material gas buffer section L22 along with new raw material gas from the raw material gas supply device G2 during the next raw material gas storage operation.

[0075] Furthermore, in the raw material gas buffer section L22 (inside the piping L21) after the raw material gas has been supplied into the chamber 3, inert gas may be supplied via the inert gas supply line L3, for example, as described later. This makes it possible to replace any excess gas remaining in the raw material gas buffer section L22 (for example, raw material gas, or a mixture of the raw material gas and the inert gas) with the inert gas.

[0076] When supplying the raw material gas accumulated in the raw material gas buffer section L22 into the chamber 3, the raw material gas buffer section L22 and the chamber 3 are in communication, but it may take a long time for the pressure between them to reach equilibrium, depending on the pressure loss in the piping.

[0077] In such cases, the gas pressure in the raw material gas buffer section L22 (for example, the mixed gas pressure of the raw material gas and carrier gas) may be increased, or the gas supply to the chamber 3 may be temporarily stopped before reaching equilibrium, and the exposure of the film-forming surface 20 to the raw material gas may be continued as appropriate while maintaining the pressure in the chamber 3.

[0078] Furthermore, while multiple raw material gas supply lines L2 may be installed in parallel with the chamber 3, if the vapor pressure of the raw material gas in each of the raw material gas supply lines L2 is different, the temperature inside each raw material gas supply line L2 can be adjusted by a temperature adjustment unit (for example, a supply pipe temperature adjustment unit having a heating mechanism such as a thermocouple, heat exchanger, or infrared heater that can adjust the temperature inside the pipe L21) not shown in the figure. For example, if there are two raw material gas supply lines L2 supplying TMA and TDMAT as raw material gases, the temperature inside each pipe L21 can be adjusted to 50°C and 150°C, respectively.

[0079] The temperature control unit may not only control the temperature of the raw material gas supply line L2, but may also control the temperature of other components. For example, as shown in Figure 1, a configuration is available in which the components within the area enclosed by the dotted line can be controlled. Specific examples include a configuration that can control the temperature inside the additional inert gas supply pipe L51 (additional supply pipe temperature control unit), as will be described later, and a configuration that can control the temperature of the inner surface 30 of the chamber 3 (inner surface temperature control unit).

[0080] <Inert gas supply line L3> The inert gas supply line L3 connects the inert gas supply device G3 and the nozzle 33 and includes an inert gas supply pipe L31 capable of supplying inert gas from the inert gas supply device G3. This pipe L31 includes an on-off valve V3 (shown in Figure 1 as on-off valves V3a and V3b located downstream of the mass flow controller L32 described later) that can switch the gas flow in the pipe L31 between a flow-allowed state (open state) and a flow-blocked state (closed state), and a mass flow controller L32 that can control the gas flow rate in the pipe L31. Various configurations can be applied to the on-off valve V3, as with the on-off valve V1, etc., and are not particularly limited.

[0081] In such an inert gas supply line L3, the inert gas can be supplied into the chamber 3 by, for example, appropriately opening and closing the on-off valve V3 and appropriately controlling the amount of inert gas supplied from the inert gas supply device G3 with the mass flow controller L32.

[0082] Furthermore, as will be described later, if the configuration allows for the supply of inert gas from within pipe L31 to within pipe L31 via the inert gas supply line L5, the temperature inside pipe L31 may be adjusted, for example, by a temperature adjustment unit (not shown).

[0083] <Bypass Line L4> In the raw material gas supply line L2, for example, as shown in Figure 1, a bypass line L4 may be provided upstream and / or downstream of the raw material gas buffer section L22 in the piping L21, which can switch between a connected state and a blocked state between the raw material gas buffer section L22 and the gas discharge section 5 using an on / off valve V4.

[0084] In the case of the bypass line L4 in Figure 1, there is a bypass pipe L41 that connects the upstream and / or downstream side of the raw material gas buffer section L22 in the piping L21 to both the on-off valve 5b and the vacuum pump 5c in the exhaust pipe 5a of the gas discharge section 5. In the on-off valve V4, various configurations can be applied, similar to the on-off valve V1, and are not particularly limited.

[0085] With such a bypass line L4, for example, in the raw material gas remaining in the raw material gas buffer section L22 as described above, it is possible to discharge it without reuse through the bypass line L4 and the gas discharge section 5.

[0086] <Inert gas addition line L5> In the raw material gas supply line L2, for example, as shown in FIG. 1, an inert gas addition line L5 may be provided that can switch the pipe L21 of the raw material gas supply line L2 and the pipe L31 of the inert gas supply line L3 between a communicating state and a blocking state by an on-off valve V5.

[0087] In the case of the inert gas addition line L5 in FIG. 1, an inert gas additional supply pipe L51 is provided that connects the downstream side of the raw material gas buffer section L22 in the pipe L21 (the on-off valve V2b having a three-way valve structure in FIG. 1) and between both the mass flow controller L32 and the on-off valve V3a in the pipe L31 of the inert gas supply line L3. Further, the pipe L51 includes a raw material gas buffer section pressure gauge P that can measure the gas pressure in the raw material gas buffer section L22. L5 In the on-off valve V4, various modes can be applied in the same manner as the on-off valve V1 etc., and it is not particularly limited.

[0088] With such an inert gas addition line L5, it is possible to supply an inert gas to the raw material gas supply line L2 and apply the inert gas as a carrier gas for the raw material gas. In this case, the gas concentration in the raw material gas buffer section L22 (the concentration of the raw material gas (mixed gas) diluted with the inert gas) can be calculated based on the calculation formula Pα / Pβ×100 by, for example, a concentration control section not shown in the figure.

[0089] In the above calculation formula, Pα is the measured value of the pressure gauge P when the raw material gas is supplied, accumulated, and sealed in the raw material gas buffer section L22 in a vacuum state. L2 Pβ is the pressure gauge P when only the inert gas is supplied into the raw material gas buffer section L22 after measuring the Pα. L5This will be the measured value.

[0090] To dilute the raw material gas with an inert gas, that is, to obtain a mixed gas of the raw material gas and the inert gas, the following raw material gas storage process and mixed gas storage process may be carried out (for example, before the raw material gas supply process S1 described later. Specific examples include those not listed in items [3], [5], and [7] below).

[0091] First, in the raw material gas storage process, the raw material gas is stored and sealed in the raw material gas buffer section L22 in the raw material gas supply line L2 until the pressure inside the buffer section L22 reaches a predetermined level.

[0092] Then, in the mixed gas storage process, an inert gas is supplied to the raw material gas buffer section L22 via piping L51 until the pressure inside the raw material gas buffer section L22 reaches a predetermined pressure that is even higher (a predetermined pressure that is higher than the pressure in the raw material gas storage process), thereby obtaining the desired mixed gas, which is then stored and sealed within the raw material gas buffer section L22.

[0093] In the mixed gas storage process, the partial pressure of the raw material gas in the mixed gas stored in the raw material gas buffer section L22 can be set as appropriate, for example, to 1000 Pa or less. The concentration of the raw material gas in the mixed gas can also be set as appropriate, for example, to 30% or less based on the partial pressure ratio of the raw material gas and the inert gas in the mixed gas. Furthermore, for example, the temperature inside the pipe L51 can be adjusted to a higher temperature than the temperature inside the pipe L21 by a temperature adjustment section (additional supply pipe temperature adjustment section) not shown in the figure.

[0094] After supplying the mixed gas into the chamber 3 as described above, when the raw material gas accumulation process and the mixed gas accumulation process are carried out again, an inert gas substitution process may be carried out in which only an inert gas is supplied into the pipe L21 in advance and the gas remaining in the pipe L21 is replaced with an inert gas (as a specific example, it may be carried out between item [5] and item [6] described later). According to this inert gas substitution process, the gas remaining in the pipe L21 will be discharged through the chamber 3 (or the bypass line L4).

[0095] <Film formation process when using an ALD apparatus> In the ALD apparatus 11, by the ALD method in which the raw material gas supply process S1, the raw material gas purge process S2, the oxidant supply process S3, and the oxidant purge process S4 shown in FIG. 3 are sequentially executed, it is possible to form a desired oxide film 21 on the film formation surface 20 of the object to be film-formed 2 in the chamber 3.

[0096] In FIG. 3, first, in the raw material gas supply process S1, the raw material gas (raw material gas containing elements constituting the target oxide film 21) of the raw material gas supply device G2 is supplied into the chamber 3 from the nozzle 32 through the raw material gas supply line L2. As a result, as shown in the reaction schematic diagram of FIG. 4(a), the raw material gas is adsorbed on the film formation surface 20 of the object to be film-formed 2 in the chamber 3, and an adsorption layer 21a by the raw material gas is formed. FIG. 4(a) depicts a state in which a monolayer of TMA gas is adsorbed on the film formation surface 20 of the substrate-like object to be film-formed 2.

[0097] If, for example, impurities or the like are attached to the film formation surface 20 of the object to be film-formed 2, it is preferable to clean the film formation surface 20 (for example, supply the inert gas of the inert gas supply device G3 into the chamber 3 through the inert gas supply line L3 and purge) in the stage before the raw material gas supply process S1 to make it easier for the raw material gas to be adsorbed on the film formation surface 20.

[0098] Following the raw material gas supply process S1, in the raw material gas purging process S2, inert gas from the inert gas supply device G3 is supplied into the chamber 3 from the nozzle 33 via the inert gas supply line L3, or the gas in the chamber 3 is drawn in and discharged by the gas discharge unit 5. This removes excess raw material gas supplied in the raw material gas supply process S1 and gas generated by the adsorption of the raw material gas onto the film-forming surface 20 from the film-forming surface 20.

[0099] Next, in the oxidizing agent supply step S3, ozone gas from the ozone gas generator G1 is supplied into the chamber 3 from the nozzle 31 via the ozone gas supply line L1. As a result, the adsorption layer 21a formed on the film-forming surface 20 is oxidized (methyl groups (CH3) are oxidized in Figure 4), as shown in the schematic reaction diagram in Figure 4(b), and an adsorption-capable region 20a for the next film formation is formed on the film-forming surface 20. This oxidation reaction, as shown in the schematic reaction diagram in Figure 4(b), is possible even at room temperature (25°C).

[0100] Then, in the oxidizing agent purging step S4, similar to the raw material gas purging step S2, inert gas from the inert gas supply device G3 is supplied into the chamber 3 from the nozzle 33 via the inert gas supply line L3, and the gas in the chamber 3 is sucked in and discharged by the gas discharge unit 5. This removes excess ozone gas supplied in the oxidizing agent supply step S3 and gas generated by oxidizing the adsorption layer 21a of the raw material gas from the film-forming surface 20.

[0101] By appropriately repeating the cycle of each of the above steps S1 to S4 (hereinafter simply referred to as the film deposition cycle), it becomes possible to form an oxide film 21 of the desired thickness on the film deposition surface 20. Various film deposition conditions in this film deposition cycle can be appropriately set, for example, according to the target oxide film 21.

[0102] Furthermore, when the aforementioned film deposition cycle is performed multiple times, for example, by supplying different types of raw material gases to the object to be filmed 2 in at least one of the raw material gas supply steps S1 and the remaining steps (if a mixed gas is supplied, a mixed gas using different types of raw material gases is supplied), it becomes possible to construct a multilayer oxide film 21 consisting of adsorption layers 21a of different raw material gases (i.e., an oxide film 21 in which multiple adsorption layers 21a are stacked).

[0103] For example, if multiple raw material gas supply lines L2 are provided in parallel with respect to the chamber 3, each raw material gas supply line L2 can be configured to supply a different type of raw material gas, and by selectively operating (supplying raw material gas to) one of the raw material gas supply lines L2 each time a film deposition cycle is performed, it becomes possible to construct a desired multilayer oxide film 21.

[0104] Specifically, the film deposition cycle shown in Figure 5 can be carried out in accordance with the following items [1] to [8]. • Item [1]; Vacuuming the chamber 3 (by drawing in the gas inside the chamber 3 through the gas discharge unit 5 to create a vacuum) • Item [2]; Implementation of oxidizing agent supply process S3 (supplying ozone gas into chamber 3 and sealing) • Item [3]; Performing the oxidizer purging process S4 (supplying inert gas into chamber 3 and vacuuming). • Item [4]; Vacuum evacuate chamber 3 • Item [5]; Implementation of raw material gas supply process S1 (supplying raw material gas into chamber 3 and sealing it) • Item [6]; Vacuum evacuate chamber 3 • Item [7]; Implementation of raw material gas purging process S2 (supplying inert gas into chamber 3 and vacuum evacuation) • Item [8]; Vacuum-evacuate chamber 3 (corresponding to item [1] in the next cycle).

[0105] Furthermore, it is preferable that the accumulation of ozone gas by the ozone gas buffer section L12 be carried out using a method other than item [2] among items [1] to [8].

[0106] Furthermore, the accumulation of raw material gas in the raw material gas buffer section L22 is preferably carried out in a manner other than item [5] from items [1] to [8]. However, when supplying inert gas to the raw material gas buffer section L22 of the raw material gas supply line L2 via the inert gas addition line L5 provided as shown in Figure 1, it is preferable to carry out the supply in a manner other than items [3], [5], and [7]. This is because supplying inert gas to the raw material gas buffer section L22 in the manner of items [3] and [7] may result in an unstable flow rate of the inert gas.

[0107] Furthermore, items [3] and [7] may be performed only once each during the film deposition cycle, or they may be performed multiple times (cycle purging). Performing items [3] and [7] multiple times in this way may make it easier to suppress gas-phase mixing between ozone gas and the source gas.

[0108] Furthermore, in each cycle purge of item [3] and [7], the amount of inert gas supplied (the total amount due to each cycle purge) can be set as appropriate. For example, this could be set to 10 times or more the amount of gas supplied into chamber 3 in the raw material gas supply process S1, or 10 times or more the amount of gas supplied into chamber 3 in the oxidizer supply process S3.

[0109] <Inert gases used in each process S1-S4> In the raw material gas purging process S2 and the oxidizer purging process S4, gas in the chamber 3 is drawn in by the gas discharge section 5, and at the same time, inert gas is supplied into the chamber 3 as needed by the inert gas supply line L3. This promotes the gas flow in the chamber 3, making it possible to shorten the time required for removing excess gas (purging).

[0110] Also, depending on the volume and shape of the chamber 3 (for example, if the volume is large (for example, if the volume is 1 m³) 3In extreme cases (such as when the chamber is extremely large) or when the shape is complex, the gas flow rate of the raw material gas or ozone gas supplied from the gas supply unit 4 may be reduced. However, as described above, it may be possible to promote the gas flow by appropriately supplying inert gas (specifically, by adjusting the amount of inert gas supplied based on the volume and shape of the chamber 3, or by supplying the inert gas intermittently).

[0111] Therefore, in each of the processes S1 to S4, the gas flow within the chamber 3 can be appropriately adjusted by supplying an inert gas as needed. This makes it easier to supply the raw material gas and ozone gas in the desired amounts, and may also make it easier to discharge the gas from the chamber 3.

[0112] <An example of object to be coated with film 2> The object to be coated 2 can be any object that can form a desired oxide film 21 on the surface 20 to be coated by performing a film deposition cycle as appropriate. Examples of such objects include solids, substrates, powders (for example, an aggregate of many particulate objects 2 to be coated), films, sheets, cloths, fibers, and various other forms.

[0113] Furthermore, in the method of forming an oxide film using a raw material gas and ozone gas at a high concentration of 80% by volume or more, the oxide film can be formed at a relatively low temperature. For example, in the case of substrates or films, it is not limited to substrates with relatively high heat resistance such as Si substrates, but can also be used to form an oxide film on substrates made of synthetic resins with relatively low heat resistance.

[0114] When the object to be coated 2 is made of resin, examples of such resins include polyester resin, aramid resin, olefin resin, polypropylene, PPS (polyphenylene sulfide), PET (polyethylene terephthalate), and the like.

[0115] Other materials used include PE (polyethylene), PEN (polyethylene naphthalate), POM (polyoxymethylene or acetal resin), PEEK (polyether ether ketone), ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), PA (polyamide), PFA (tetrafluoroethylene, perfluoroalkoxyethylene copolymer), PI (polyimide), PVD (polyvinyl dichloride), etc.

[0116] The surface 20 of the object to be coated 2 is not limited to being simply flat, but can be of various forms. For example, the object to be coated 2 shown in Figure 2 is a solid with multiple trench grooves 22 formed therein, and uneven steps and the like are formed on the surface 20.

[0117] Furthermore, the object to be coated 2 may be appropriately temperature-controlled, for example, by heating or cooling it using a temperature control unit (not shown) to improve the coating performance. A specific example is adjusting the temperature as needed so that the coating temperature of the surface 20 to be coated is within the range of room temperature to 100°C.

[0118] <Example of raw material gas> The raw material gas applied in the raw material gas supply process S1 may include elements that form an oxide film (for example, lithium (Li), magnesium (Mg), silicon (Si), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), indium (In), tin (Sn), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), lead (Pb), etc.; hereinafter these elements will be referred to as metals or metallic elements) as constituent elements.

[0119] Examples include raw material gases containing organosilicon having Si-O bonds or Si-C bonds, or organometallic compounds having metal element-oxygen bonds or metal element-carbon bonds, as well as raw material gases such as organometallic complexes or silicon or metal hydrides.

[0120] More specifically, examples include those using silane (a general term for hydrogen silicide), TEOS (TetraEthyl OrthoSilicate), TMS (TriMthoxySilane), TES (TriEthoxySilane), TMA (TriMethyl Aluminum), TEMAZ (Tetrakis(ethylmethylamino)zirconium), 3DAMAS (tridimethylaminosilane; SiH[N(CH3)2]3), TDMAT (tetrakisdimethylaminotitanium; Ti[N(CH3)2]4), TDMAH (tetrakisdimethylaminohafnium; Hf[N(CH3)2]4), etc. as raw material gases. In addition, examples include those using heterogeneous binuclear complexes containing not just one type of metal element but multiple types of metal elements (for example, complexes described in Japanese Patent Application Publication No. 2016-210742, etc.).

[0121] <An example of ozone gas> In the oxidizing agent supply step S3, ozone gas of various concentrations can be used, but a higher ozone concentration is preferable. Specifically, in high-concentration ozone gas, it is preferable to have an ozone concentration (volume %) of 80 to 100% by volume. Such high-concentration ozone gas can be obtained by liquefying and separating only the ozone from the ozone-containing gas based on the difference in vapor pressure, and then vaporizing the liquefied ozone again.

[0122] Examples of ozone gas generators G1 include those disclosed in patent documents such as Japanese Patent Publication No. 2001-304756 and Japanese Patent Publication No. 2003-20209. Such ozone gas generators G1 produce high-concentration ozone (ozone concentration ≈ 100% by volume) by liquefying and separating only ozone based on the difference in vapor pressure between ozone and other gases (e.g., oxygen). In particular, if the generator is equipped with multiple chambers for liquefying and vaporizing only ozone, a continuous supply of high-concentration ozone gas can be achieved by individually controlling the temperature of these chambers.

[0123] One example of a commercially available device that generates high-concentration ozone gas is the Pure Ozone Generator (MPOG-HM1A1) manufactured by Meidensha.

[0124] <An example of an inert gas> The inert gas can be any gas that can be used, for example, in the raw material gas purging process S2 or the oxidizer purging process S4, or as a carrier gas for the raw material gas. Examples of such inert gases include N2, Ar, and He.

[0125] <An example of nozzles 31-33> The nozzles 31 to 33 should each be capable of supplying ozone gas, raw material gas, and inert gas to the chamber 3 in a desired amount (flow rate, etc.), pressure, etc., and various configurations can be applied.

[0126] Furthermore, the nozzles 31-33 may not be provided one at a time for each chamber 3, but may also be provided in multiples. The shape of the nozzles 31-33 can be set as appropriate, and examples include circular, rectangular, elliptical, or slit-shaped nozzles.

[0127] The supply volume and pressure of each gas supplied from outlets 31-33 can be appropriately set by, for example, appropriately operating the ozone gas supply line L1, the raw material gas supply line L2, and the inert gas supply line L3, respectively.

[0128] <Example of gas supply volume, pressure, etc.> The supply amounts of raw material gas, ozone gas, and inert gas to chamber 3, as well as the pressure exerted by each gas (for example, the partial pressure due to ozone gas in chamber 3), can be appropriately controlled and set. One example of this is setting the parameters considering the type, shape, and number of objects to be film-deposited 2 in chamber 3, as well as the type and concentration of each gas.

[0129] As a specific example, when performing a film deposition cycle using steps S1 to S4 as shown in Figure 5, the supply amounts of each gas are appropriately set so that the process pressure inside the chamber 3 during the film deposition cycle remains within a range of 1000 Pa or less. More specifically, inert gas is supplied into the chamber 3 from the inert gas supply line L3 (for example, intermittently as described later), and this supply is appropriately controlled and set so that the base pressure remains within a range of approximately 1 Pa to 1000 Pa. The time required for one film deposition cycle can be set as appropriate and is not particularly limited, but for example, it can be set to a few seconds to several tens of seconds (for example, 3 seconds to 60 seconds).

[0130] Furthermore, when supplying 80% by volume or more of ozone gas into the chamber 3 in the oxidizing agent supply step S3, it is possible to supply it in various ways. One example is to increase the exposure amount of the ozone gas to the film-forming surface 20 to 1 × 10⁻¹⁰ 5 The pressure should be above Langmuir, and the ozone gas stored in the ozone gas buffer section L12 should be supplied to the chamber 3 within 1 second, with the amount of ozone gas supplied being appropriately set so that the pressure in the chamber 3 is within the range of 10 to 1000 Pa.

[0131] However, the exposure amount of ozone gas (1 × 10 5The control of Langmuir or higher levels is an example of the exposure level required when TMA is used as the precursor (raw material gas). Therefore, if the type of precursor is different (other than TMA), the required exposure level will change, for example, depending on the ease with which the oxidation reaction by ozone occurs.

[0132] For example, if an inert gas is present in the chamber 3 in addition to ozone gas, the partial pressure of the ozone gas will be set to 100 Pa or less. Furthermore, the pressure increase due to the supply of ozone gas will be appropriately set to 100 Pa or less, preferably 50 Pa or less, and more preferably 10 Pa or less.

[0133] This oxidizing agent supply process S3 makes it possible to sufficiently oxidize the adsorbed layer 21a adsorbed on the film-forming surface 20 in the raw material gas supply process S1.

[0134] The amount of raw material gas supplied to the chamber 3 in the raw material gas supply step S1 can be set, for example, so that the raw material gas is adsorbed onto the film-forming surface 20 and sufficiently oxidized (an oxide film is formed) in the subsequent oxidizing agent supply step S3, and is not particularly limited.

[0135] As a specific example, the exposure amount of the raw material gas to the film-forming surface 20 is 1 × 10⁻⁶. 4 One possible method is to appropriately set the supply amount of the raw material gas so that the pressure is greater than or equal to Langmuir. Furthermore, when supplying a mixed gas of raw material gas and inert gas into the chamber 3 in the raw material gas supply process S1, it is possible to supply it in various ways. One example is to complete the supply of the mixed gas accumulated in the raw material gas buffer section L22 into the chamber 3 within 1 second, and to appropriately set the supply amount of the mixed gas so that the pressure inside the chamber 3 is within the range of 0.1 to 100 Pa.

[0136] However, the exposure amount of the raw material gas (1 × 10 5The control of Langmuir or higher is an example of the exposure amount required when TMA is used as the precursor and when a material with a metallic substance deposited on the film-forming surface 20 (e.g., Si) is used as the object to be film-formed 2. Therefore, if the type of precursor or the type of deposited metallic substance is different, the amount of precursor adsorbed on the film-forming surface 20 will change, and it will be necessary to appropriately adjust the exposure amount of the raw material gas according to the amount of change.

[0137] The sealing time for the gas supplied into the chamber 3 by the raw material gas supply process S1 (raw material gas, or a mixed gas of the raw material gas and an inert gas), and the sealing time for the gas supplied into the chamber 3 by the oxidant supply process S3 (ozone gas) can be set as appropriate. For example, each can be set within the range of 1 to 1000 seconds. Specifically, the sealing time can be set as appropriate within the range of 1 to 1000 seconds, taking into consideration the shape of the film-forming surface 20 of the object to be film-formed (such as uneven steps).

[0138] In the raw material gas purging process S2 and the oxidizer purging process S4, the amount of inert gas supplied to the chamber 3 can be set as appropriate, as long as the process pressure remains within the range of 1000 Pa or less, as described above. For example, when purging is being performed by the gas discharge section 5, the amount can be set to an amount that can assist the purging. A specific example is to intermittently supply inert gas to the chamber 3 via the inert gas supply line L3 and set it appropriately so as not to over-dilute the raw material gas or ozone gas in the chamber 3 (for example, set to within 10 times the amount of ozone gas supplied).

[0139] <An example of a gas discharge section 5> The exhaust from the gas discharge section 5 is not particularly limited, as long as it can maintain a reduced pressure state inside the chamber 3 so that the process pressure inside the chamber 3 remains within the range of 1000 Pa or less, as described above.

[0140] In the case of the gas discharge section 5 shown in Figure 1, the configuration includes an exhaust pipe 5a, an on-off valve 5b, a vacuum pump 5c, etc., but it is also possible to have a configuration that appropriately includes an ozone killer (a purifying equipment such as a purifying cylinder that decomposes ozone; not shown) etc. Furthermore, it is preferable to use a vacuum pump 5c that is resistant to ozone (for example, a dry pump).

[0141] Alternatively, multiple exhaust lines may be provided in the gas discharge section 5, and each exhaust line may be used separately in each process S1 to S4. This makes it possible to distribute the exhaust gas from each process S1 to S4 to dedicated pollution control equipment for treatment.

[0142] <Example of a support structure> The support portion that supports the object to be coated 2 housed in the chamber 3 can be any form that supports it in such a way as not to hinder the coating process on the surface 20 to be coated, and is not particularly limited.

[0143] <Example 1; Amount of raw material gas adsorption for item [5] by ALD apparatus 11> In item [5], after performing item [4] using the ALD apparatus 11 described above, the pressure inside the chamber 3 and the raw material gas buffer section L22, and the amount of raw material gas adsorbed onto the film-forming surface 20 of the object to be film-formed 2 were verified.

[0144] Under these verification conditions, the volume of chamber 3 was 50,000 cc, and the volume of the raw material gas buffer section L22 was 100 cc (the same applies to Example 2 described later). The raw material gas accumulated in the raw material gas buffer section L22 was diluted via the inert gas supply line L3 and the inert gas addition line L5, so that the gas pressure in the raw material gas buffer section L22 of the diluted raw material gas (mixed gas) was 1,000 Pa (partial pressure of the raw material gas was 133 Pa). Furthermore, TMA and Si substrate were applied to the raw material gas and the object to be film-deposited 2, respectively.

[0145] First, when item [5] was carried out, the pressure inside the chamber 3 and the raw material gas buffer section L22 was approximately 10 Pa, and the partial pressure of the raw material gas was 1.33 Pa. Also, when the exposure time of the raw material gas to the film-forming surface 20 of the object to be film-formed 2 was 1 second, the amount of adsorption of the raw material gas was approximately 1 × 10⁻⁶ 4 It was about the same level as Langmuir.

[0146] From these results, we were able to confirm that, for example, if the adsorption probability of the film-forming surface 20 is 0.001, the exposure time required for saturation to a film density (coverage rate) of approximately 1 is about 1 second.

[0147] <Example 2; Amount of ozone gas adsorption of item [2] by ALD device 11> In item [2], after performing item [1] using the ALD apparatus 11 described above, the amount of ozone gas adsorbed onto the film-forming surface 20 of the object to be film-formed was verified.

[0148] In this second embodiment, the volume of chamber 3 was reduced to approximately 1 / 10 of the volume of chamber 3 used in the first embodiment. This reduction was due to the fact that in this second embodiment, only one object 2 to be coated was housed in chamber 3, making it easy to blow ozone gas onto the coating surface 20, and thus sufficiently suppressing ozone gas adhesion to the chamber walls. This demonstrated that, when the gas blowing position onto the coating surface 20 is appropriately set, the impact of gas reduction due to wall adhesion can be suppressed, allowing for a reduction in the chamber volume. Under these verification conditions, the ozone gas concentration accumulated in the ozone gas buffer section L12 was set to 80-100% by volume, and a Si substrate was used as the object to be coated 2.

[0149] First, when item [2] was carried out, it was found that when the pressure inside the chamber 3 was 40 Pa and the exposure time of the ozone gas to the film-forming surface 20 of the object to be film-formed 2 was 1 second, the amount of ozone gas adsorbed was approximately 3 × 10⁻¹⁴ 5 It was about the same level as Langmuir.

[0150] From these results, it was confirmed that even when multiple objects to be coated 2 are placed in the chamber 3, it is possible to form an oxide film 21 on each of the surfaces 20 to be coated simultaneously.

[0151] <Example 3; Example of film formation using ALD apparatus 11> A film deposition cycle was carried out using the ALD apparatus 11 described above (items [1] to [8] were carried out as appropriate), and the film thickness (nm) of the oxide film 21 formed on the opening edge surface 22a and bottom surface 22b of the trench groove 22 was observed in cross-section, and the observation results are shown in Figure 6.

[0152] In Figure 6, column (A) represents the case where ozone gas is diluted with an inert gas (Ar) in item [2], and column (B) represents the case where ozone gas is not diluted in item [2] (when the ozone gas concentration is 80-100% by volume). Furthermore, TMA was used as the raw material gas, and the object to be filmed 2 was a Si substrate in which trench grooves 22 with a depth of 140 μm and an opening width of 3.5 μm were formed.

[0153] According to Figure 6, the thickness of the oxide film 21 on the opening edge surface 22a and the bottom surface 22b, as depicted in column (B), is 119 nm and 78 nm, respectively. Compared to the oxide film 21 depicted in column (A), it is formed thicker, and the aspect ratio (thickness of the oxide film 21 on the bottom surface 22b / thickness of the oxide film 21 on the opening edge surface 22a) is higher.

[0154] In other words, in item [2], it was found that increasing the ozone gas concentration allowed more ozone molecules to reach the depths of the trench grooves 22, thereby sufficiently promoting the formation of the oxide film 21 on the bottom surface 22b of the trench grooves 22. In particular, it was found that high-concentration (80-100% by volume) ozone gas obtained after a liquefaction process contains fewer heavy metal impurities, for example, and can not only reduce impurities in the oxide film 21 but also improve the coverage of the oxide film 21 on the trench grooves 22.

[0155] <Example 4; Configuration example of piping L11, L21, L31> In the piping L11, L21, and L31 of the ALD apparatus 11 described above, various configurations can be applied as long as they can appropriately supply each gas into the chamber 3.

[0156] For example, the downstream ends of pipes L11 and L21 (the ends on the chamber 3 side) are not simply configured to be connectable to nozzles 31 and 32 as shown in Figure 1, but rather the nozzles 31 and 32 are made to penetrate the chamber 3 in an inward direction and extend into the chamber 3. An example of such a configuration for the downstream ends of pipes L11 and L21 is a nozzle structure having an ozone gas nozzle section 61 and a raw material gas nozzle section 62, as shown in Figures 7 and 8, respectively.

[0157] The gas nozzle sections 61 and 62 shown in Figures 7 and 8 each have a cylindrical tubular portion 6a protruding from the positions of the outlets 31 and 32 on the inner circumferential surface 30 of the chamber 3, a lid portion 6b sealing one end of the tubular portion 6a in the axial direction, and a plurality of nozzle holes 6c penetrating the outer circumferential surface of the tubular portion 6a in the radial direction of the tubular portion 6a. The nozzle holes 6c are arranged at predetermined intervals (for example, interval d3 described later) with respect to the axial direction of the tubular portion 6a.

[0158] In the case of Figure 8, both gas nozzle sections 61 and 62 within the chamber 3 are positioned parallel to each other, protruding from the inner circumferential surface 30, as shown in Figure 8, with the nozzle holes 6c of gas nozzle section 61 and gas nozzle section 62 facing each other.

[0159] The materials and shapes applied to these gas nozzle sections 61 and 62 are not particularly limited, but they should be appropriately selected considering the various gases supplied into the chamber 3 and the supply amounts. For example, they can be appropriately selected from stainless steel (SUS), quartz, ceramic, etc., and the material can be molded into the desired shape. An example of such a shape is to set the inner diameter d1 of the cylindrical section 6a to a range of 2 to 10 mm, the hole diameter d2 of the nozzle hole 6c to a range of 1 to 5 mm, and the distance d3 between adjacent nozzle holes 6c to 5 mm or more.

[0160] Furthermore, the gas nozzle sections 61 and 62 may be integrated into the downstream ends of the pipes L11 and L21, respectively, or they may be detachably attached to the downstream ends (for example, the opening 6d shown in Figure 8 may be detachably attached).

[0161] The object to be coated 2 can be appropriately placed within the chamber 3, but for example, as shown in Figure 8, it can be positioned so that the opening edge surface 22a of the object to be coated 2 faces the space between the two gas nozzles 61 and 62 (hereinafter simply referred to as the space between the nozzles 61 and 62 as appropriate).

[0162] With the nozzle structure piping L11 and L21 as in this embodiment 4, each gas supplied into the chamber 3 by the piping L11 and L21 can be injected into the chamber 3 through the nozzle holes 6c of the gas nozzle sections 61 and 62, respectively (for example, as shown by the dotted arrows in Figure 8), making it easier for the gases to diffuse (hereinafter simply referred to as gas diffusion) within the chamber 3.

[0163] Furthermore, as shown in Figure 8, when the nozzle holes 6c of the gas nozzle section 61 and the nozzle holes 6c of the gas nozzle section 62 are positioned opposite each other, both ozone gas and the raw material gas (or a mixture of raw material gas and inert gas) (hereinafter simply referred to as "both gases") can collide with each other. This allows both gases to diffuse (diffuse before adhesion) while suppressing adhesion to the inner circumferential surface 30, etc., thus enabling effective gas diffusion.

[0164] In this embodiment 4, when the film deposition cycle was performed using the ALD apparatus 11 in the same manner as in embodiment 3, it was confirmed that it was possible to deposit an oxide film 21 similar to that shown in Figure 6.

[0165] <Example 5; An example of a configuration for heating each gas in the chamber 3> Figure 9 shows an example of a configuration for heating each gas in the chamber 3 according to Embodiment 5, in which a heating unit (chamber heating unit) 63 is positioned between nozzles 61 and 62.

[0166] The heating section 63 in Figure 9 consists of a cylindrical heating element and is supported and installed so as to extend from between the nozzles 31 and 32 on the inner circumferential surface 30 of the chamber 3.

[0167] The heating unit 63 only needs to be able to heat both gases between nozzles 61 and 62, and various configurations can be applied, but preferably, it is configured to heat both gases between nozzles 61 and 62 to a temperature higher than the temperature inside piping L11 and piping L21.

[0168] With a heating configuration like that of this embodiment 5, the two gases ejected from the nozzle holes 6c of the gas nozzle sections 61 and 62 can be heated and interfered with by the heating section 63 between the nozzles 61 and 62 while colliding. This may suppress excessive physical adsorption of the raw material gas (or a mixed gas of raw material gas and inert gas) compared to, for example, the case of embodiment 4. In addition, since both gases are heated between the nozzles 61 and 62, it is possible to suppress the reliquefaction of the two gases during gas diffusion.

[0169] In this Example 5, as in Example 3, a film deposition cycle was performed using the ALD apparatus 11, and it was confirmed that it was possible to deposit an oxide film 21 similar to that shown in Figure 6.

[0170] <Example 6; Another example of a configuration for heating each gas in chamber 3> Figure 10 shows another example of the configuration for heating each gas in the chamber 3 according to Embodiment 6. In Figure 10, both gas nozzles 61 and 62 are positioned to protrude from the inner circumferential surface 30 so as to be parallel to each other, and the nozzle holes 6c of gas nozzle 61 and gas nozzle 62 are positioned in opposite directions.

[0171] The chamber 3 in Figure 10 is configured to allow the temperature of the inner surface 30 to be adjusted as appropriate by, for example, a temperature adjustment unit (inner surface temperature adjustment unit) not shown in the figure. As an example of temperature adjustment for the inner surface 30, it is possible to set it as appropriate, but it is preferable that it be adjusted to a temperature higher than the temperature inside the ozone gas supply pipe and the temperature inside the raw material gas supply pipe.

[0172] On the inner circumferential surface 30, a gas flow guide portion 64 is provided that protrudes from the inner circumferential surface 30, and is configured to guide each gas flowing along the inner circumferential surface 30 toward the location where the object to be filmed 2 is housed in the chamber 3.

[0173] The gas flow guide section 64 only needs to be configured to appropriately guide each gas within the chamber 3 as described above, and its shape and the number of guide sections provided within the chamber can be set as appropriate. In the case of the gas flow guide section 64 shown in Figure 10, it is provided at a position offset from the ejection direction of the nozzle hole 6c relative to the inner circumferential surface 30 (a position offset downward from the ejection direction shown by the dotted arrow in Figure 10), and has a curved shape that extends toward the housing position of the object to be filmed 2 within the chamber 3.

[0174] With a heating configuration like that of this embodiment 6, for example, without arranging a heating unit 63 inside the chamber 3 as in embodiment 5, both gases ejected from the nozzle holes 6c of the gas nozzle units 61 and 62 can be heated, and similar to embodiment 5, it is possible to suppress the reliquefaction of both gases during gas diffusion. Furthermore, since a heating unit 63 like in embodiment 5 is unnecessary, it may contribute to the simplification and miniaturization of the chamber 3. In addition, by appropriately installing a gas flow guide unit 64 on the inner circumferential surface 30, the desired gas diffusion can be sufficiently achieved inside the chamber 3.

[0175] In this embodiment 6, as in embodiment 3, a film deposition cycle was performed using the ALD apparatus 11, and it was confirmed that it was possible to deposit an oxide film 21 similar to that shown in Figure 6.

[0176] Although the ALD method and ALD apparatus of the present invention have been described above with reference to specific embodiments, the ALD method and ALD apparatus of the present invention are not limited to these embodiments, and can be appropriately modified in design without impairing their features. Modified designs also fall within the technical scope of the present invention. [Explanation of symbols]

[0177] 11...ALD equipment 2...Object to be coated, 20...Surface to be coated, 20a...Adsorption possible area, 21...Oxide film, 21a...Adsorption layer, 22...Trench groove 3...Chamber, 30...Inner surface, 31-33...Outlet 4…Gas supply department 5...Gas exhaust section 61, 62... Gas nozzle section, heating section 63, gas flow guide section 64 L1…Ozone gas supply line, L11…Ozone gas supply piping, L12…Ozone gas buffer section L2…raw gas supply line, L21…raw gas supply piping, L22…raw gas buffer section L3...Inert gas supply line, L31...Inert gas supply piping L4...Bypass line, L41...Bypass piping L5...Inert gas addition line, L51...Inert gas additional supply piping G1…Ozone gas generator, G2…Raw material gas supply device, G3…Inert gas supply device

Claims

1. A chamber capable of freely accommodating an object to be coated, having uneven steps formed on the surface to be coated, A gas supply unit that supplies gas into the chamber, A gas discharge unit that draws in gas from inside the chamber and discharges it outside the chamber, maintaining a reduced pressure state inside the chamber, Equipped with, The gas supply department, A raw material gas supply line having raw material gas supply piping capable of supplying raw material gas into a chamber, An ozone gas supply line having ozone gas supply piping capable of supplying 80% or more volume of ozone gas into the chamber, An inert gas supply line having an inert gas supply pipe capable of supplying inert gas into a chamber, Equipped with, The ozone gas supply line is An ozone gas buffer unit is provided in the ozone gas supply piping, which can store and seal ozone gas in the ozone gas supply piping by opening and closing an on / off valve installed in the ozone gas supply piping, and can also supply the stored ozone gas into the chamber. An ozone gas buffer pressure gauge measures the gas pressure inside the ozone gas buffer section, Equipped with, The downstream end of the ozone gas supply piping has an ozone gas nozzle portion that protrudes from the inner circumferential surface of the chamber. The downstream end of the raw material gas supply piping has a raw material gas nozzle portion that protrudes from the inner circumferential surface of the chamber. The ozone gas nozzle section and the raw material gas nozzle section are, A cylindrical portion that protrudes and extends from the inner circumferential surface of the chamber, A lid portion that seals the tip of the cylindrical portion in the direction of the protrusion, Multiple nozzle holes that penetrate the outer surface of the cylindrical portion in the radial direction of the cylindrical portion, It has, The ozone gas nozzle and the raw material gas nozzle protrude from the inner circumferential surface of the chamber so as to be parallel to each other. The nozzle holes of the ozone gas nozzle and the nozzle holes of the raw material gas nozzle are located opposite each other. A chamber heating unit is positioned between the ozone gas nozzle and the raw material gas nozzle within the chamber to heat the space between them. The atomic layer deposition apparatus is characterized in that the chamber heating section is capable of heating the space between the two within the chamber to a temperature higher than the temperature in the ozone gas supply pipe and the temperature in the raw material gas supply pipe.

2. A chamber capable of freely accommodating an object to be coated, having uneven steps formed on the surface to be coated, A gas supply unit that supplies gas into the chamber, A gas discharge unit that draws in gas from inside the chamber and discharges it outside the chamber, maintaining a reduced pressure state inside the chamber, Equipped with, The gas supply department, A raw material gas supply line having raw material gas supply piping capable of supplying raw material gas into a chamber, An ozone gas supply line having ozone gas supply piping capable of supplying 80% or more volume of ozone gas into the chamber, An inert gas supply line having an inert gas supply pipe capable of supplying inert gas into a chamber, Equipped with, The ozone gas supply line is An ozone gas buffer unit is provided in the ozone gas supply piping, which can store and seal ozone gas in the ozone gas supply piping by opening and closing an on / off valve installed in the ozone gas supply piping, and can also supply the stored ozone gas into the chamber. An ozone gas buffer pressure gauge measures the gas pressure inside the ozone gas buffer section, Equipped with, The downstream end of the ozone gas supply piping has an ozone gas nozzle portion that protrudes from the inner circumferential surface of the chamber. The downstream end of the raw material gas supply piping has a raw material gas nozzle portion that protrudes from the inner circumferential surface of the chamber. The ozone gas nozzle section and the raw material gas nozzle section are, A cylindrical portion that protrudes and extends from the inner circumferential surface of the chamber, A lid portion that seals the tip of the cylindrical portion in the direction of the protrusion, Multiple nozzle holes that penetrate the outer surface of the cylindrical portion in the radial direction of the cylindrical portion, It has, The chamber is further equipped with an inner surface temperature adjustment unit for adjusting the temperature of the inner surface, The inner surface temperature adjustment unit is capable of adjusting the temperature of the inner surface of the chamber to a higher temperature than the temperature inside the ozone gas supply pipe and the temperature inside the raw material gas supply pipe. The ozone gas nozzle and the raw material gas nozzle protrude from the inner circumferential surface of the chamber so as to be parallel to each other. The nozzle holes of the ozone gas nozzle and the nozzle holes of the raw material gas nozzle are positioned in opposite directions to each other. The inner surface of the chamber is provided with a gas flow guide portion that protrudes from the inner surface of the chamber. An atomic layer deposition apparatus characterized in that the gas flow guide section extends from the inner circumferential surface of the chamber toward the location where the object to be deposited is housed within the chamber.

3. The atomic layer deposition apparatus according to claim 1 or 2, further comprising an ozone gas accumulation control unit that controls the amount of ozone gas accumulated in the ozone gas buffer unit based on the change in the measured value of the ozone gas buffer unit pressure gauge.

4. The atomic layer deposition apparatus according to any one of claims 1 to 3, characterized in that the volume inside the ozone gas buffer section is 1 / 50 or more of the volume inside the chamber.

5. The atomic layer deposition apparatus according to any one of claims 1 to 4, characterized in that the volume of the ozone gas supply piping downstream of the ozone gas buffer section is within the range of 1 / 10 to 1 / 2 of the volume of the ozone gas buffer section.

6. The atomic layer deposition apparatus according to any one of claims 1 to 5, characterized in that multiple raw material gas supply lines are provided in parallel with respect to the chamber.

7. The atomic layer deposition apparatus according to claim 6, further comprising a supply pipe temperature adjustment unit capable of adjusting the temperature inside the raw material gas supply pipes of each raw material gas supply line.

8. The raw gas supply line is, A raw material gas buffer unit is provided in the raw material gas supply piping, which can store and seal the raw material gas in the raw material gas supply piping by opening and closing an on / off valve installed in the raw material gas supply piping, and can also supply the stored raw material gas into the chamber. A raw material gas buffer pressure gauge measures the gas pressure inside the raw material gas buffer section, An atomic layer deposition apparatus according to any one of claims 1 to 7, characterized by comprising the above.

9. The atomic layer deposition apparatus according to claim 8, further comprising a raw material gas storage amount control unit that controls the amount of raw material gas stored in the raw material gas buffer unit based on the change in the measured value of the raw material gas buffer unit pressure gauge.

10. The atomic layer deposition apparatus according to claim 8 or 9, characterized in that the volume in the raw material gas buffer section is 1 / 500 or more of the volume in the chamber.

11. The atomic layer deposition apparatus according to any one of claims 8 to 10, characterized in that the volume of the raw material gas supply piping downstream of the raw material gas buffer section is within the range of 1 / 10 to 1 / 2 of the volume of the said raw material gas buffer section.

12. The atomic layer deposition apparatus according to any one of claims 8 to 11, characterized in that a bypass line is provided on the upstream and / or downstream side of the raw material gas buffer section in the raw material gas supply piping, the bypass piping having a bypass pipe that can switch between a connected state and a blocked state between the raw material gas buffer section and the gas discharge section.

13. The atomic layer deposition apparatus according to any one of claims 1 to 12, characterized in that the raw material gas supply line includes an additional inert gas supply line having an additional inert gas supply pipe that can switch between a connected state and a blocked state between the raw material gas supply pipe and the inert gas supply pipe.

14. The raw material gas supply line includes an additional inert gas supply line which has an additional inert gas supply pipe that can switch between a connected state and a blocked state between the raw material gas supply pipe and the inert gas supply pipe. The atomic layer deposition apparatus according to any one of claims 8 to 12, characterized in that the raw material gas buffer section can store and seal a mixed gas, which is a mixture of the raw material gas in the raw material gas supply pipe and the inert gas supplied to the raw material gas supply pipe from the inert gas supply pipe via the additional inert gas supply pipe, by opening and closing an on-off valve provided in the raw material gas supply pipe, and can supply the stored mixed gas into the chamber.

15. The atomic layer deposition apparatus according to claim 14, further comprising an additional supply pipe temperature adjustment unit capable of adjusting the temperature inside the additional inert gas supply pipe to a higher temperature than the temperature inside the raw material gas supply pipe.

16. A method for forming an oxide film on the surface of an object to be filmed in the chamber of an atomic layer deposition apparatus according to any one of claims 1 to 15, wherein A raw material gas supply step involves supplying a raw material gas containing elements that constitute an oxide film into a chamber to form an adsorption layer of the raw material gas on the surface to be filmed, A raw material gas purging step removes excess raw material gas supplied in the raw material gas supply step and gas generated by the adsorption of said raw material gas onto the film-forming surface from the film-forming surface. A step of supplying an oxidizing agent to oxidize the adsorption layer formed on the film-forming surface by supplying 80% or more of ozone gas into the chamber, An oxidizing agent purging step removes excess ozone gas supplied in the oxidizing agent supply step and gas generated by oxidizing the adsorption layer from the film-forming surface. A method for atomic layer deposition characterized by having the following features.

17. A method for forming an oxide film on a film-forming surface of an object to be filmed, which has uneven steps formed on it within the chamber of the atomic layer deposition apparatus, using an atomic layer deposition apparatus, A raw material gas supply step involves supplying a mixed gas, which is a mixture of a raw material gas containing elements constituting the oxide film and an inert gas, into a chamber to form an adsorption layer on the surface to be filmed by the raw material gas in the mixed gas, A raw material gas purging step removes excess gas from the mixed gas supplied in the raw material gas supply step and gas generated by the adsorption of the raw material gas in the mixed gas onto the film-forming surface from the film-forming surface. A step of supplying an oxidizing agent to oxidize the adsorption layer formed on the film-forming surface by supplying 80% or more of ozone gas into the chamber, An oxidizing agent purging step removes excess ozone gas supplied in the oxidizing agent supply step and gas generated by oxidizing the adsorption layer from the film-forming surface. It has, The atomic layer deposition apparatus is A chamber capable of freely accommodating the object to be coated, A gas supply unit that supplies gas into the chamber, A gas discharge unit that draws in gas from inside the chamber and discharges it outside the chamber, maintaining a reduced pressure state inside the chamber, Equipped with, The gas supply department, A raw material gas supply line having raw material gas supply piping capable of supplying raw material gas into a chamber, An ozone gas supply line having ozone gas supply piping capable of supplying 80% or more volume of ozone gas into the chamber, An inert gas supply line having an inert gas supply pipe capable of supplying inert gas into a chamber, Equipped with, The ozone gas supply line is An ozone gas buffer unit is provided in the ozone gas supply piping, which can store and seal ozone gas in the ozone gas supply piping by opening and closing an on / off valve installed in the ozone gas supply piping, and can also supply the stored ozone gas into the chamber. An ozone gas buffer pressure gauge measures the gas pressure inside the ozone gas buffer section, Equipped with The raw gas supply line is, A raw material gas buffer unit is provided in the raw material gas supply piping, which can store and seal the raw material gas in the raw material gas supply piping by opening and closing an on / off valve installed in the raw material gas supply piping, and can also supply the stored raw material gas into the chamber. A raw material gas buffer pressure gauge measures the gas pressure inside the raw material gas buffer section, An inert gas supply line having an inert gas supply pipe that can switch between a connected state and a blocked state between a raw gas supply pipe and an inert gas supply pipe, Equipped with, The raw material gas buffer section can store and seal the mixed gas, which is a mixture of the raw material gas in the raw material gas supply pipe and the inert gas supplied from the inert gas supply pipe to the raw material gas supply pipe via the additional inert gas supply pipe, by opening and closing an on-off valve provided in the raw material gas supply pipe, and can also supply the stored mixed gas into the chamber. The mixed gas in the raw material gas supply process is A raw material gas storage step involves accumulating and sealing the raw material gas within the raw material gas buffer until a predetermined pressure is reached within the raw material gas buffer section. A mixed gas storage step involves supplying inert gas to the raw material gas buffer section via an inert gas additional supply pipe until the pressure inside the raw material gas buffer section reaches a predetermined pressure that is higher than that in the raw material gas storage step, thereby obtaining the mixed gas, storing it in the raw material gas buffer section, and sealing it. A method for atomic layer deposition characterized by obtaining the layer by performing the following in advance.

18. The partial pressure of the raw material gas in the mixed gas accumulated in the raw material gas buffer section during the mixed gas accumulation process shall be 1000 Pa or less, and the concentration of the raw material gas in the mixed gas shall be 30% or less, calculated based on the partial pressure ratio of the raw material gas and the inert gas in the mixed gas. The atomic layer deposition method according to claim 17, characterized in that it is as described above.

19. The atomic layer deposition method according to claim 17 or 18, characterized in that the raw material gas supply step completes the supply of the mixed gas accumulated in the raw material gas buffer section to the chamber within 1 second, and the pressure in the chamber is within the range of 0.1 to 100 Pa.

20. The atomic layer deposition method according to any one of claims 17 to 19, characterized in that, after the raw material gas supply process, an inert gas is supplied into the raw material gas supply pipe to replace the gas remaining in the raw material gas supply pipe with the inert gas.

21. The atomic layer deposition method according to any one of claims 16 to 20, characterized in that the partial pressure of ozone gas accumulated in the ozone gas buffer section by the oxidizing agent supply step is 10,000 Pa or less.

22. The atomic layer deposition method according to any one of claims 16 to 21, characterized in that the oxidizing agent supply step completes the supply of ozone gas accumulated in the ozone gas buffer section to the chamber within 1 second, and the pressure in the chamber is set to a range of 10 to 1000 Pa.

23. The raw material gas supply process supplies gas into the chamber and seals it for a certain period of time, and then the raw material gas purging process exhausts the gas out of the chamber. The atomic layer deposition method according to any one of claims 16 to 22, characterized in that a gas is supplied into the chamber by an oxidizing agent supply step and sealed for a certain period of time, and then the gas is exhausted out of the chamber by an oxidizing agent purging step.

24. The raw material gas purging process and the oxidizer purging process are carried out by repeatedly supplying inert gas into the chamber multiple times. The atomic layer deposition method according to claim 23, characterized in that the amount of inert gas supplied to be supplied multiple times is 10 times or more the amount of gas supplied to the chamber in the raw material gas supply step, or 10 times or more the amount of gas supplied to the chamber in the oxidizer supply step.

25. The atomic layer deposition method according to claim 23 or 24, characterized in that the sealing time of the gas supplied into the chamber by the raw material gas supply step and the sealing time of the gas supplied into the chamber by the oxidizer supply step are each within the range of 1 to 1000 seconds.

26. The cycle consisting of the raw material gas supply process, raw material gas purging process, oxidizer supply process, and oxidizer purging process is performed multiple times. The atomic layer deposition method according to any one of claims 16 to 25, characterized in that the raw material gas used in at least one of the raw material gas supply processes and the raw material gas used in the remaining processes are of different types.

27. The oxide film is Al ２ O ３ 、HfO ２ 、TiO ２ 、ZnO、Ta ２ O ３ 、Ga ２ O ３ 、MoO ３ 、RuO ２ 、SiO ２ 、ZrO ２ 、Y ２ O ３ and includes an adsorption layer of any one of them, and the atomic layer deposition method according to any one of claims 16 to 26, characterized in that.

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