Film forming device and film forming method

Abstract

The present invention is a film-forming apparatus comprising at least: an atomizing unit that atomizes a raw material solution to generate mist; a pipe connected to the atomizing unit and conveying a carrier gas containing the mist; at least one pipe conveying an additive fluid, which is mixed with the carrier gas containing the mist and has one or more gases as a main component; a pipe connected to the film-forming unit and conveying a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; a connecting member connecting the pipe conveying the carrier gas containing the mist, the pipe conveying the additive fluid, and the pipe conveying the mixed mist fluid; and a film-forming unit that heat-treats the mist to form a film on a substrate, wherein the angle formed between the pipe conveying the additive fluid and the pipe conveying the mixed mist fluid, connected by the connecting member, is 120 degrees or greater. Thus, a film-forming apparatus capable of applying an atomized CVD method with excellent film-forming speed is provided.

Description

Technical Field

[0001] The present invention relates to a film forming device and a film forming method for forming a film on a substrate using a mist-like raw material. Background Art

[0002] High-vacuum film-forming equipment has been developed that can achieve non-equilibrium conditions using methods such as pulsed laser deposition (PLD), molecular beam epitaxy (MBE), and sputtering. This makes it possible to produce oxide semiconductors that were previously impossible using melt processes.

[0003] Furthermore, a mist chemical vapor deposition (Mist CVD) method (hereinafter referred to as "mist CVD") has been developed, which uses atomized, mist-like raw materials to grow crystals on a substrate. This method enables the production of gallium oxide (α-Ga2O3) with a corundum structure. α-Ga2O3, as a semiconductor with a large bandgap, is expected to be used in next-generation switching devices that achieve high withstand voltage, low loss, and high heat resistance.

[0004] Regarding the atomization CVD method, Patent Document 1 describes a tubular furnace-type atomization CVD apparatus. Patent Document 2 describes a fine channel-type atomization CVD apparatus. Patent Document 3 describes a linear source-type atomization CVD apparatus. Patent Document 4 describes a tubular furnace-type atomization CVD apparatus, which differs from the atomization CVD apparatus described in Patent Document 1 in the introduction of a carrier gas into the mist generator. Patent Document 5 describes an atomization CVD apparatus in which a substrate is placed above the mist generator and a rotating table with a base is mounted on a hot plate.

[0005] exist Figure 13 Patent Document 6 shows Figure 1 An enlarged view of the connection portion 301h of the pipe for conveying the carrier gas containing mist and the pipe for conveying the dilution gas. Figure 13As shown, Patent Document 6 describes an atomization CVD apparatus in which a pipe 303 for conveying a dilution gas, i.e., an additive fluid, is connected at right angles to a pipe 302 for conveying a carrier gas containing mist and a pipe 304 for conveying a mixed mist fluid. The apparatus uses the carrier gas to convey mist produced in a raw material supply system, and a dilution gas (additive fluid) having a flow vector B of the additive fluid perpendicular to the flow vector A of the carrier gas containing mist is mixed with the dilution gas. The flow vector C of the mixed mist fluid is parallel to the flow vector A of the carrier gas containing mist. The in-plane film thickness distribution is improved by using a supply unit that adjusts the linear velocity of the mixed mist fluid independently of the mist delivery rate using the dilution gas and supplies the mixed mist fluid in opposite directions.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 1-257337

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2005-307238

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2012-46772

[0011] Patent Document 4: Japanese Patent No. 5397794

[0012] Patent Document 5: Japanese Patent Application Laid-Open No. 2014-63973

[0013] Patent Document 6: Japanese Patent Application Laid-Open No. 2020-2396

[0014] Patent Document 7: Japanese Patent Application Laid-Open No. 2020-2426 Summary of the Invention

[0015] (1) Technical issues to be solved

[0016] The atomized CVD method is different from other CVD methods in that it can form films at relatively low temperatures and can also produce a quasi-stable phase crystal structure such as the corundum structure of α-Ga2O3.

[0017] However, the inventors have discovered a new problem: during the mist transport process, the mist collides with the piping due to the dilution gas, i.e., the additive fluid, and condenses. Furthermore, the additive fluid flows back into the piping containing the mist carrier gas, thereby reducing the mist transport efficiency and the film formation rate. This problem becomes more pronounced when the flow rate is higher, i.e., when film formation is being performed on large-area substrates or multiple substrates that require a large amount of gas. To address this problem, Patent Document 7 describes an atomizing CVD device that heats the mist transport section to extend the life of the mist and increase the film formation rate. However, even with this method, the reduction in film formation rate cannot be completely eliminated.

[0018] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a film forming apparatus to which an atomization CVD method having an excellent film forming speed can be applied, and a film forming method having an excellent film forming speed.

[0019] (2) Technical solution

[0020] The present invention is made to achieve the above-mentioned purpose and provides a film-forming device, which at least comprises: an atomizing section, which atomizes the raw material solution to generate mist; a piping connected to the atomizing section and transporting a carrier gas containing the mist; at least one piping for transporting an additive fluid mixed with the carrier gas containing the mist and having one or more gases as main components; a piping connected to the film-forming section and transporting a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; a connecting component, which connects the piping for transporting the carrier gas containing the mist, the piping for transporting the additive fluid, and the piping for transporting the mixed mist fluid; and a film-forming section, which heat-treats the mist to form a film on a substrate, and the angle formed by the piping for transporting the additive fluid and the piping for transporting the mixed mist fluid connected by the connecting component is greater than 120 degrees.

[0021] This film forming apparatus can suppress the backflow of the additive fluid into the pipe conveying the carrier gas containing mist with a simple apparatus structure, and can also suppress the reduction of mist due to collision with the wall surface of the connection portion, thereby increasing the film forming speed.

[0022] In this case, the angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid can be set to 180 degrees.

[0023] This can further suppress the backflow of the additive fluid into the pipe conveying the carrier gas containing the mist, and further suppress the reduction of the mist due to collision with the pipe wall surface at the connection portion, thereby further improving the film formation speed.

[0024] In this case, the linear velocity of the adding fluid can be set to 1 to 100 times the linear velocity of the carrier gas containing the mist.

[0025] In this way, the reduction of mist caused by collision with the wall surface of the connection part can be further suppressed. In addition, by utilizing the injection effect to attract the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further improved.

[0026] In addition, the present invention provides a film forming device, which at least comprises: an atomizing section, which atomizes the raw material solution to generate mist; a piping connected to the atomizing section and transporting a carrier gas containing the mist; at least one piping for transporting an additive fluid mixed with the carrier gas containing the mist and having one or more gases as main components; a piping connected to the film forming section and transporting a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; a connecting component, which connects the piping for transporting the carrier gas containing the mist, the piping for transporting the additive fluid, and the piping for transporting the mixed mist fluid; and a film forming section, which heat-treats the mist to form a film on a substrate, and the angle formed by the piping for transporting the additive fluid and the piping for transporting the mixed mist fluid connected by the connecting component is greater than 100 degrees, so that the linear velocity of the additive fluid in the connecting section is greater than the linear velocity of the carrier gas containing the mist.

[0027] This film-forming apparatus, with its simple structure, can prevent the additive fluid from flowing back into the pipe conveying the mist-containing carrier gas, even when a large flow rate of gas is flowing. Furthermore, it can prevent the reduction of mist due to collision with the wall surface of the connection portion, thereby increasing the film-forming speed.

[0028] In this case, the film forming apparatus can be provided so that the angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid is 120 degrees or more.

[0029] This can further suppress the backflow of the additive fluid into the pipe conveying the carrier gas containing the mist, and further suppress the reduction of the mist due to collision with the pipe wall surface at the connection portion, thereby further improving the film formation speed.

[0030] In this case, the film forming apparatus can be configured so that the linear velocity of the adding fluid in the connecting portion is 10 times or more the linear velocity of the carrier gas containing the mist.

[0031] In this way, the reduction of mist caused by collision with the wall surface of the connection part can be further suppressed. In addition, by utilizing the injection effect to attract the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further improved.

[0032] In this case, the film forming apparatus can be provided in which the cross-sectional area of ​​the portion of the connecting member connected to the pipe for conveying the additive fluid is smaller than the cross-sectional area of ​​the portion of the connecting member connected to the pipe for conveying the carrier gas containing the mist.

[0033] As a result, the flow rate of the additive fluid can at least increase the linear velocity of the additive fluid, and the degree of freedom of the linear velocity of the mist is improved, which is industrially advantageous.

[0034] In this case, the film forming apparatus can be configured so that the flow rate of the carrier gas is 8 L / min or more.

[0035] As a result, even when forming a film on a large-area substrate that requires a large flow rate, the film can be formed at a higher film forming speed.

[0036] In this case, the substrate can be set to have a processing area of ​​10 cm 2 The above-mentioned film forming device is used for the substrate.

[0037] This makes it possible to form a film over a large area at a faster film forming speed.

[0038] In addition, the present invention provides a film-forming method, comprising the following steps: atomizing a raw material solution in an atomizing section to generate mist; supplying a carrier gas to the atomizing section and transporting the carrier gas containing the mist from the atomizing section; mixing the carrier gas containing the mist and at least one additive fluid having one or more gases as main components to form a mixed mist fluid; transporting the mixed mist fluid to a film-forming section; and heat-treating the mist in the mixed mist fluid in the film-forming section to form a film on a substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is made less than 60 degrees.

[0039] According to such a film forming method, the backflow of the additive fluid into the piping for conveying the carrier gas containing the mist can be suppressed, and the reduction of the mist caused by collision with the wall surface of the connection part can be suppressed, thereby significantly improving the mist conveying efficiency and increasing the film forming speed.

[0040] At this time, the angle formed by the flow vector of the adding fluid and the flow vector of the mixed mist fluid can be set to 0 degrees.

[0041] This can further suppress the backflow of the adding fluid into the pipe for conveying the carrier gas containing the mist, further improve the mist conveying efficiency, and further increase the film formation speed.

[0042] In this case, the linear velocity of the adding fluid can be set to 1 to 100 times the linear velocity of the carrier gas containing the mist.

[0043] This can further improve the transport efficiency of the mist. In addition, by utilizing the jet effect to draw the low-speed carrier gas flow containing the mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further increased.

[0044] The present invention also provides a film-forming method, comprising the following steps: atomizing a raw material solution in an atomizing section to generate mist; supplying a carrier gas to the atomizing section and transporting the carrier gas containing the mist from the atomizing section; mixing the carrier gas containing the mist and at least one additive fluid having one or more gases as main components to form a mixed mist fluid; transporting the mixed mist fluid to a film-forming section; and heat-treating the mist in the mixed mist fluid in the film-forming section to form a film on a substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is made less than 80 degrees, and the linear velocity of the additive fluid in the connecting section is made greater than the linear velocity of the carrier gas containing the mist.

[0045] According to such a film forming method, the backflow of the additive fluid into the piping for conveying the carrier gas containing the mist can be suppressed, and the reduction of the mist caused by collision with the wall surface of the connection part can be suppressed, thereby significantly improving the mist conveying efficiency and increasing the film forming speed.

[0046] In this case, the angle formed by the flow vector of the adding fluid and the flow vector of the mixed mist fluid can be set to 60 degrees or less.

[0047] This can further suppress the backflow of the adding fluid into the pipe for conveying the carrier gas containing the mist, further improve the mist conveying efficiency, and further increase the film formation speed.

[0048] In this case, the linear velocity of the adding fluid in the connecting portion can be set to 10 times or more the linear velocity of the carrier gas containing the mist.

[0049] This can further improve the transport efficiency of the mist. In addition, by utilizing the jet effect to draw the low-speed carrier gas flow containing the mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further increased.

[0050] In this case, the flow rate of the carrier gas can be set to 8 L / min or more.

[0051] As a result, even when forming a film on a large-area substrate that requires a large flow rate, the film can be formed at a higher film forming speed.

[0052] At this time, the usable area as the substrate is 10 cm 2 The above matrix.

[0053] This enables film formation over a large area at a faster film formation speed.

[0054] (3) Beneficial effects

[0055] As described above, the film-forming apparatus of the present invention can, with a simple device structure, suppress the backflow of the additive fluid into the pipe conveying the carrier gas containing the mist, thereby suppressing the reduction of the mist due to collision with the wall surface of the connection portion. This improves the mist conveying efficiency and significantly improves the film-forming speed. Furthermore, the film-forming method of the present invention can significantly improve the mist conveying efficiency and significantly improve the film-forming speed using a simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic structural diagram of the film forming apparatus of the present invention.

[0057] Figure 2 This is a schematic structural diagram of a raw material supply system of the film forming apparatus of the present invention.

[0058] Figure 3 This is a diagram illustrating an example of an atomizing section of a raw material supply system of the film forming apparatus of the present invention.

[0059] Figure 4 This is a diagram illustrating an example of a connection portion of a raw material supply system of the film forming apparatus of the present invention.

[0060] Figure 5 This is a diagram illustrating another example of the connection portion of the raw material supply system of the film forming apparatus of the present invention.

[0061] Figure 6 This is a diagram illustrating still another example of the connection portion of the raw material supply system of the film forming apparatus of the present invention.

[0062] Figure 7 This is a diagram illustrating still another example of the connection portion of the raw material supply system of the film forming apparatus of the present invention.

[0063] Figure 8 This is a diagram illustrating still another example of the connection portion of the raw material supply system of the film forming apparatus of the present invention.

[0064] Figure 9 This is a diagram illustrating still another example of the connection portion of the raw material supply system of the film forming apparatus of the present invention.

[0065] Figure 10 This is a diagram illustrating the connection portion of the raw material supply system of the film forming apparatus used in Example 13.

[0066] Figure 11 It is a figure which shows the result of Example.

[0067] Figure 12 It is a figure which shows the result of Example.

[0068] Figure 13 This is a diagram illustrating an example of a connection portion of a raw material supply system of a conventional film-forming apparatus. DETAILED DESCRIPTION

[0069] The present invention will be described in detail below, but the present invention is not limited thereto.

[0070] As described above, a film forming apparatus to which the atomization CVD method having an excellent film forming speed can be applied and a film forming method having an excellent film forming speed are being sought.

[0071] The inventors have repeatedly conducted in-depth research on the above-mentioned technical problems, and as a result, found that the following film-forming device can be used to form a film-forming device capable of applying an atomized CVD method with an excellent film-forming speed, and completed the present invention. The film-forming device at least comprises: an atomizing section that atomizes the raw material solution to generate mist; a pipe connected to the atomizing section and conveying a carrier gas containing the mist; at least one pipe conveying an additive fluid mixed with the carrier gas containing the mist and having one or more gases as main components; a pipe connected to the film-forming section and conveying a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; a connecting component that connects the pipe conveying the carrier gas containing the mist, the pipe conveying the additive fluid, and the pipe conveying the mixed mist fluid; and a film-forming section that performs heat treatment on the mist to form a film on a substrate, wherein the angle formed by the pipe conveying the additive fluid and the pipe conveying the mixed mist fluid connected by the connecting component is greater than 120 degrees.

[0072] The inventors also discovered that by using the following film-forming device, a film-forming device capable of applying an atomized CVD method with excellent film-forming speed can be achieved, and the present invention was completed. The film-forming device comprises at least: an atomizing section that atomizes a raw material solution to generate mist; a pipe connected to the atomizing section and conveying a carrier gas containing the mist; at least one pipe conveying an additive fluid mixed with the carrier gas containing the mist and having one or more gases as main components; a pipe connected to the film-forming section and conveying a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; a connecting component that connects the pipe conveying the carrier gas containing the mist, the pipe conveying the additive fluid, and the pipe conveying the mixed mist fluid; and a film-forming section that heat-treats the mist to form a film on a substrate, the angle formed by the pipe conveying the additive fluid and the pipe conveying the mixed mist fluid connected by the connecting component being greater than 100 degrees, so that the linear velocity of the additive fluid in the connecting section is greater than the linear velocity of the carrier gas containing the mist.

[0073] In addition, it was discovered that the following film-forming method can be used to form a film-forming method with an excellent film-forming speed, and the present invention was completed. The film-forming method includes the following steps: atomizing a raw material solution in an atomizing section to generate mist; supplying a carrier gas to the atomizing section and transporting the carrier gas containing the mist from the atomizing section; mixing the carrier gas containing the mist and at least one additive fluid with one or more gases as main components to form a mixed mist fluid; transporting the mixed mist fluid to a film-forming section; and heat-treating the mist in the mixed mist fluid in the film-forming section to form a film on a substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is made less than 60 degrees.

[0074] It was also discovered that the following film-forming method can be used to form a film-forming method with an excellent film-forming speed, and the present invention was completed. The film-forming method includes the following steps: atomizing a raw material solution in an atomizing section to generate mist; supplying a carrier gas to the atomizing section and transporting the carrier gas containing the mist from the atomizing section; mixing the carrier gas containing the mist and at least one additive fluid with one or more gases as main components to form a mixed mist fluid; transporting the mixed mist fluid to a film-forming section; and heat-treating the mist in the mixed mist fluid in the film-forming section to form a film on a substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is made less than 80 degrees, and the linear velocity of the additive fluid in the connecting section is made greater than the linear velocity of the carrier gas containing the mist.

[0075] The following description will be given with reference to the accompanying drawings.

[0076] Here, the term "mist" in the present invention is a general term for liquid particles dispersed in gas, and includes cases where it is called mist, droplets, etc.

[0077] The film-forming apparatus of the present invention comprises at least: an atomizing unit that atomizes a raw material solution to generate mist; a pipe connected to the atomizing unit and conveying a carrier gas containing mist; at least one pipe conveying an additive fluid that is mixed with the carrier gas containing mist and has one or more gases as a main component; a pipe connected to the film-forming unit and conveying a mixed mist fluid obtained by mixing the carrier gas containing mist and the additive fluid; a connecting member that connects the pipe conveying the carrier gas containing mist, the pipe conveying the additive fluid, and the pipe conveying the mixed mist fluid; and a film-forming unit that heat-treats the mist to form a film on a substrate. The components of the film-forming apparatus of the present invention are described in detail below. In addition, the description of matters common to the various figures may be omitted as appropriate.

[0078] (Film forming device)

[0079] Figure 1An example of a film forming apparatus 401 of the present invention is shown. The film forming apparatus 401 comprises: a carrier gas supply section 120, an additive fluid supply section 130, an atomizing section 201, a film forming section 420 for performing heat treatment on the mist to form a film on a substrate 403, a mixed mist fluid conveying section 107, and a connecting section 301 for connecting the additive fluid supply section 130, the atomizing section 201, and the mixed mist fluid conveying section 107. In addition, the film forming apparatus 401 is provided with a control section (not shown) for controlling the entire or a part of the film forming apparatus 401, thereby controlling the operation of the film forming apparatus 401. In the following, the film forming section 420 and the raw material supply system 101 (which is on the upstream side of the film forming section 420 as viewed from the flow of the raw material) are described. Figure 2 Refer to) for separate explanation.

[0080] (Raw material supply system)

[0081] Figure 2 The following illustrates an example of a raw material supply system 101 according to the present invention. The raw material supply system 101 includes an atomizing unit 201 that atomizes a raw material solution 102a to generate a mist; a carrier gas supply unit 120 that supplies a carrier gas for transporting the mist; an additive fluid supply unit 130 that supplies an additive fluid to be mixed with the carrier gas containing the mist; a mixed mist fluid delivery unit 107 that delivers a mixed mist fluid obtained by mixing the carrier gas containing the mist and the additive fluid; and a connecting unit 301 that connects the atomizing unit 201, the additive fluid supply unit 130, and the mixed mist fluid delivery unit 107. The carrier gas supply unit 120 is connected to the additive fluid supply unit 130 and the mixed mist fluid delivery unit 107 via the atomizing unit 201.

[0082] (Atomization part)

[0083] In the atomizing section 201, the raw material solution 102a is prepared and atomized to generate mist. The atomizing unit is not particularly limited as long as it can atomize the raw material solution 102a. A known atomizing unit may be used, but an atomizing unit based on ultrasonic vibration is preferably used because it can generate a more stable atomization.

[0084] Also refer to Figure 3An example of such an atomizing section 201 will be described below. For example, the atomizing section 201 may include: a mist generating source 102 containing a raw material solution 102a, a container 103 containing a medium capable of transmitting ultrasonic vibrations, such as water 103a, and an ultrasonic vibrator 104 mounted on the bottom surface of the container 103. In detail, the mist generating source 102 containing the raw material solution 102a is housed in the container 103 containing the water 103a using a support body (not shown). The ultrasonic vibrator 104 is mounted on the bottom of the container 103 and is connected to the oscillator 202. Furthermore, the structure is such that when the oscillator 202 is operated, the ultrasonic vibrator 104 vibrates, and the ultrasonic wave is transmitted to the mist generating source 102 via the water 103a, and the raw material solution 102a is atomized.

[0085] (Carrier gas supply unit)

[0086] like Figure 1 、 2 As shown, the carrier gas supply unit 120 includes a carrier gas source 105a for supplying carrier gas. In this case, a flow rate regulating valve 105b may be provided for regulating the flow rate of the carrier gas sent from the carrier gas source 105a.

[0087] The type of carrier gas is not particularly limited and can be appropriately selected according to the film-forming material. For example, inert gases such as oxygen, ozone, nitrogen, and argon, or reducing gases such as hydrogen and synthetic gas can be cited. In addition, the type of carrier gas can be one or more. For example, a dilution gas obtained by diluting the same gas as the first carrier gas with another gas (for example, by 10 times) can be used as the second carrier gas, or air can be used.

[0088] Furthermore, the carrier gas supply location may not be just one location, but may be two or more locations. The carrier gas flow rate is not particularly limited. For example, when forming a film on a substrate with a diameter of 4 inches (about 100 mm), the carrier gas flow rate is preferably 1 to 80 L / min, and more preferably 2 to 20 L / min.

[0089] The flow rates in the present invention are measured values ​​at 20°C. When measured at other temperatures or when different types of flow rates (mass flow rate, etc.) are measured, they can be converted to volume flow rates at 20°C using the gas state equation.

[0090] (Adding fluid supply section)

[0091] like Figure 1 、 2 As shown, the additive fluid supply unit 130 includes an additive fluid source 106a for supplying additive fluid. In this case, a flow rate regulating valve 106b may be provided for regulating the flow rate of gas in the additive fluid sent from the additive fluid source 106a.

[0092] The additive fluid contains one or more gases as its main component. The type of gas is not particularly limited and can be appropriately selected depending on the film to be formed. Examples include inert gases such as oxygen, ozone, nitrogen, and argon, or reducing gases such as hydrogen and forming gas. Furthermore, the additive fluid may contain mist as long as it contains one or more gases as its main component.

[0093] The additional fluid may be supplied to two or more locations, rather than just one. The flow rate of the gas in the additional fluid is not particularly limited. When forming a film on a substrate with a diameter of 4 inches (approximately 100 mm), the flow rate is preferably 1 to 80 L / min, more preferably 4 to 40 L / min.

[0094] (Connection)

[0095] Also refer to Figure 4 An example of the connection section 301 will be described below. The connection section 301 includes: a pipe 302 connected to the atomizing section 201 and conveying a carrier gas containing mist; a pipe 303 conveying an additive fluid to be mixed with the carrier gas containing mist in the additive fluid supply section 130; a pipe 304 conveying a mixed mist fluid obtained by mixing the carrier gas containing mist and the additive fluid in the mixed mist fluid conveying section 107 connected to the film forming section 402; and a connecting member 305 connecting these pipes.

[0096] Materials of these pipes and connecting members include, but are not limited to, glass, quartz, vinyl chloride, chlorinated polyether, acrylic resin, fluororesin (perfluoroalkoxyalkane, polytetrafluoroethylene, polychlorotrifluoroethylene), polyethylene, polypropylene, polystyrene polyurethane, and the like.

[0097] In the film forming apparatus of the present invention, the connection portion 301 is connected by a connection member 305 so that the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid connected by the connection member 305 is greater than 120 degrees. In particular, it is more preferably 180 degrees. For example, Figure 5 The connecting portion 301a is an example in which the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is 120 degrees. Figure 4 The connection portion 301 is an example where θ is 180 degrees. If the connection portion 301 is configured as described above, the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is large (120 degrees or more), thereby preventing the additive fluid from flowing back into the pipe 302 for conveying the carrier gas containing the mist. Furthermore, regardless of the connection method, the reduction of the mist caused by the collision of the carrier gas containing the mist with the wall surface of the connection portion can be suppressed. The flow vectors (A to C in the figure) will be described later.

[0098] If the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is greater than 120 degrees, then Figure 6 The connecting member 305b of the connecting portion 301b, Figure 7 Like the connecting member 305c of the connecting portion 301c, the direction (connection angle) of the pipe 302 for conveying the carrier gas containing the mist is not limited.

[0099] If the angle θ between the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is greater than 120 degrees, the following can be done: Figure 8 In this case, the angles formed by the pipe 303 for conveying the additive fluid and the second pipe 303d for conveying the additive fluid with the pipe 304 for conveying the mixed mist fluid may be different. Figure 9 As shown, the thickness and cross-sectional area of ​​the portion connecting the pipes may be different.

[0100] In this case, the linear velocity of the additive fluid is preferably 1 to 100 times the linear velocity of the carrier gas containing mist. This can be achieved by controlling the flow rates of the respective fluids using the aforementioned control unit, or by adjusting the flow rate of the additive fluid, the cross-sectional area of ​​the piping, and the flow rate of the carrier gas containing mist, and the cross-sectional area of ​​the piping.

[0101] In this way, the reduction of mist caused by collision with the wall surface of the connection part can be further suppressed. In addition, by utilizing the injection effect to attract the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further improved.

[0102] In the film forming apparatus of the present invention, the connection portion 301 is connected by a connection member 305 so that the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid connected by the connection member 305 is greater than 100 degrees; and the linear velocity of the additive fluid in the connection portion 301 is set to be greater than the linear velocity of the carrier gas containing the mist. In this case, it is particularly preferred to be greater than 120 degrees, and more preferably 180 degrees. For example, Figure 5 The connecting member 305a of the connecting portion 301a is an example in which the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is 120 degrees. Figure 4This is an example where θ is 180 degrees. If the connection portion 301 is configured as described above, the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is large (100 degrees or more), thereby preventing the additive fluid from flowing back into the pipe 302 for conveying the carrier gas containing the mist. Furthermore, regardless of the connection method, the reduction of the mist caused by the collision of the carrier gas containing the mist with the wall surface of the connection portion can be suppressed.

[0103] In addition, at this time, as for the linear velocity of the additive fluid, there is no particular limitation as long as the linear velocity of the additive fluid in the connecting portion 301 is greater than the linear velocity of the carrier gas containing mist. The effect of the present invention can be more significantly exerted when the linear velocity is 10 times or more. In addition, the upper limit of the ratio of the linear velocities is not particularly limited. The faster the speed of the additive fluid, the more significantly the effect of suppressing the decrease in film forming speed brought about by the structure of the present invention can be exerted. In order to set it up like this, the flow rate of each fluid can be controlled by the above-mentioned control unit, and it can also be achieved by adjusting the flow rate of the additive fluid, the cross-sectional area of ​​the piping, and the flow rate of the carrier gas containing mist, and the cross-sectional area of ​​the piping. In the connecting portion 301, the cross-sectional area of ​​the portion of the connecting component 305 connected to the piping 303 for conveying the additive fluid can be less than the cross-sectional area of ​​the portion of the connecting component 305 connected to the piping 302 for conveying the carrier gas containing mist. For example, by Figure 9 Like the connecting part 305e of the connecting part 301e, the part of the connecting part 305e connected to the pipe 303 for conveying the additive fluid is made thinner (with a smaller cross-sectional area) than the part connected to other pipes, so that the linear speed can be increased with a small amount of additive fluid, which increases the freedom of the linear speed of the mist and is advantageous in industry. In addition, if the total amount of gas supplied to the film forming part is large, the heat of the film forming part is taken away by the gas, resulting in a problem of reduced crystallinity of the film obtained by film formation. Therefore, by setting Figure 9 Such a structure can suppress the exhaust heat caused by the gas, improve the transport efficiency of the mist, and increase the film formation speed.

[0104] The linear velocity can be calculated by dividing the volume flow rate at 20°C by the cross-sectional area. When measuring at other temperatures or measuring different types of flow rates (mass flow rate, etc.), the volume flow rate at 20°C can be converted using the gas state equation.

[0105] In this way, the reduction caused by the collision of the mist with the wall of the connection part can be further suppressed. In addition, by utilizing the injection effect to introduce the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part, the mist can be transported more stably and the film formation speed can be further improved.

[0106] (Film forming section)

[0107] In the film forming unit 420, the mist is heated to generate a thermal reaction, and a film is formed on a part or the entire surface of the substrate 403. The film forming unit 420 includes, for example, a film forming chamber 402, in which the substrate 403 is placed, and can include a hot plate 404 for heating the substrate 403. The hot plate 404 can be as follows: Figure 1 As shown, it is provided outside the film forming chamber 402, but may be provided inside the film forming chamber 402. In addition, in the film forming chamber 402, an exhaust port 405 for exhausting gas may be provided at a position that does not affect the supply of mist to the substrate 403.

[0108] In the present invention, the substrate 403 may be placed face down on the upper surface of the film forming chamber 402 or may be placed face up on the bottom surface of the film forming chamber 402 .

[0109] Furthermore, it is more preferable that the film forming device can process an area of ​​10 cm in the film forming section. 2 In the case where the substrate is a circular wafer, it is preferably capable of processing wafers with a diameter of, for example, 2 inches (about 50 mm) or more. If such a film forming device is used, a large area of ​​film can be formed at a faster film forming speed.

[0110] (Raw material solution)

[0111] The raw material solution 102a is not particularly limited as long as it contains a material that can be atomized, and can be either an inorganic material or an organic material. A metal or metal compound can be used as appropriate, and a raw material solution containing one or more metals selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel, and cobalt can be used.

[0112] The raw material solution 102a is not particularly limited as long as it can atomize the above-mentioned metal. As the raw material solution 102a, a raw material solution obtained by dissolving or dispersing the metal in an organic solvent or water in the form of a complex or salt can be appropriately used. As the form of the complex, for example, acetylacetone complex, hydroxy complex, ammonia complex, hydrogenated complex, etc. can be mentioned. As the form of the salt, for example, chloride metal salt, bromide metal salt, iodide metal salt, etc. can be mentioned. In addition, a solution formed by dissolving the above-mentioned metal in hydrobromic acid, hydrochloric acid, hydroiodic acid, etc. can also be used as an aqueous salt solution.

[0113] In addition, additives such as hydrohalic acid and oxidizing agents may be mixed into the raw material solution 102a. Examples of the hydrohalic acid include hydrobromic acid, hydrochloric acid, and hydroiodic acid, with hydrobromic acid and hydroiodic acid being preferred. Examples of the oxidizing agent include peroxides such as hydrogen peroxide (H2O2), sodium peroxide (Na2O2), barium peroxide (BaO2), and benzoyl peroxide (C6H5CO)2O2, and organic peroxides such as hypochlorous acid (HClO), perchloric acid, nitric acid, ozone water, peracetic acid, and nitrobenzene.

[0114] Furthermore, the raw material solution 102a may also contain a dopant. The dopant is not particularly limited. For example, n-type dopants such as tin, germanium, silicon, titanium, zirconium, vanadium, or niobium, or p-type dopants such as copper, silver, tin, iridium, or rhodium may be mentioned. The concentration of the dopant may be, for example, about 1×10 16 / cm 3 ~1×10 22 / cm 3 , which can be about 1×10 17 / cm 3 The following low concentrations can also be about 1×10 20 / cm 3 Above high concentration.

[0115] (Matrix)

[0116] The substrate 403 is not particularly limited as long as it can form a film and support the film. The material of the substrate 403 is not particularly limited either, and a well-known substrate can be used, which can be an organic compound or an inorganic compound. For example, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, iron, aluminum, stainless steel, gold and other metals, silicon, sapphire, quartz, glass, gallium oxide, lithium tantalate, etc. can be cited, but are not limited to these. The thickness of the substrate is not particularly limited, and is preferably 10 to 2000 μm, and more preferably 50 to 800 μm. The area of ​​the substrate is not particularly limited, and is preferably 10 cm 2 When the substrate is a circular wafer, a wafer with a diameter of 2 inches (about 50 mm) or more is preferred because it can form a film over a large area at a relatively high film forming speed.

[0117] In addition, the film formation can be carried out directly on the substrate, or it can be stacked on top of the intermediate layer formed on the substrate. The intermediate layer is not particularly limited, and for example, it can be mainly composed of an oxide of any one of aluminum, titanium, vanadium, chromium, iron, gallium, rhodium, indium, and iridium. More specifically, it is Al2O3, Ti2O3, V2O3, Cr2O3, Fe2O3, Ga2O3, Rh2O3, In2O3, and Ir2O3. In addition, when two elements selected from the above metal elements are set as A and B, it can be composed of (Ax B 1-x )2O3 (0 < x < 1) represented by a binary metal oxide, or, in the case where three elements selected from the above metal elements are set as A, B, and C, it can be (A x B y C 1-x-y )2O3(0<x<1, 0<y<1) is a ternary metal oxide.

[0118] (Film Formation Method)

[0119] The film forming method of the present invention includes the following steps: atomizing a raw material solution 102a in an atomizing section 201 to generate a mist; supplying a carrier gas to the atomizing section 201 and conveying the carrier gas containing the mist from the atomizing section 201; mixing the carrier gas containing the mist with at least one additive fluid having one or more gases as a main component to form a mixed mist fluid; conveying the mixed mist fluid to a film forming section 420; and heat-treating the mist in the mixed mist fluid in the film forming section 420 to form a film on a substrate 403. Furthermore, the method is characterized in that, in the step of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is set to 60 degrees or less.

[0120] The following reference Figure 1 、 2 An example of the film-forming method of the present invention will be described. In one embodiment of the film-forming method of the present invention, in a raw material supply system, when a mist generated by atomizing or dropletizing a raw material solution is transported to a substrate within a film-forming section via a carrier gas, a fluid is added to form a mixed mist fluid, and the mist is thermally reacted on the substrate to form a film.

[0121] First, the raw material solution 102a is placed in the mist generating source 102, the substrate 403 is placed on the hot plate 404 directly or via the wall of the film forming chamber 402, and the hot plate 404 is operated. Next, the flow control valve 105b is opened to supply carrier gas from the carrier gas source 105a into the film forming chamber 402. After the atmosphere in the film forming chamber 402 has been fully replaced with the carrier gas, the flow rates of the carrier gas and the gas in the additive fluid are adjusted using the flow control valves 105b and 106b, respectively.

[0122] Next, in the atomizing section 201 , the ultrasonic vibrator 104 is vibrated, and the vibration is propagated to the raw material solution 102 a through the water 103 a , thereby atomizing the raw material solution 102 a to generate mist (mist generating step).

[0123] Next, the mist is transported to the connection portion 301 by the carrier gas supplied to the atomizing portion 201 (a step of transporting the carrier gas containing the mist from the atomizing portion).

[0124] Then, in the connection portion 301 , the carrier gas containing the mist and at least one type of additive fluid containing one or more types of gases as main components are mixed to form a mixed mist fluid (a step of forming a mixed mist fluid).

[0125] At this time, if Figure 4 、 5 As shown, in the process of forming the mixed mist fluid, the angle formed by the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is set to be less than 60 degrees. In addition, when the angle formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is set to θ (degrees), the angle between the above-mentioned vectors B and C corresponds to 180-θ (degrees). That is, as described with respect to the above-mentioned connection portion 301, the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid are connected so that the angle θ formed is greater than 120 degrees, and the additive fluid and the mixed mist fluid are conveyed. In this case, if expressed as "the angle formed by the flow vector B of the additive fluid and the flow vector of the mixed mist fluid", it is less than 60 degrees. In the connection portion 301, the angle formed by the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid can be set to 60 degrees, or it can also be set to 0 degrees. Thus, the angle formed by the flow vector B of the addition fluid and the flow vector C of the mixed mist fluid is set to 60 degrees or less, and more preferably 0 degrees.

[0126] As mentioned above, Figure 5 This is an example where the angle θ formed by the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is 120 degrees. When the gas is caused to flow toward such a connection portion 301, the angle formed by the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is 60 degrees. Figure 4 In the example shown (θ=180 degrees), the angle formed by the flow vector B of the adding fluid and the flow vector C of the mixed mist fluid is 0 degrees.

[0127] As long as the angle between the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is less than 60 degrees, the flow vector A (direction) of the carrier gas containing the mist is not limited (see Figure 6 、 7 ).

[0128] In this case, the linear velocity of the addition fluid is preferably 1 to 100 times that of the mist-containing carrier gas. For example, the flow rate of the addition fluid and the flow rate of the mist-containing carrier gas can be adjusted according to the cross-sectional area of ​​each pipe.

[0129] In this way, the reduction of mist caused by collision with the wall of the connection part can be further suppressed. In addition, by utilizing the injection effect to attract the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part 301, the mist can be transported stably, which can further increase the film formation speed.

[0130] The mixed mist fluid is then transported to the substrate 403 in the film forming chamber 402 via the mixed mist fluid transport unit 107 (a step of transporting the mixed mist fluid to the film forming unit). This improves the efficiency of transporting the mist to the film forming unit 420.

[0131] Furthermore, the mist in the mixed mist fluid undergoes a thermal reaction within the film forming chamber 402 using the heat from the hot plate 404, and forms a film on the substrate 403. By supplying the mist in this manner, the mist introduced into the film forming chamber 402 forms a film on the substrate 403 at a high film forming rate (a film forming process). Furthermore, the gas within the film forming chamber 402 can be exhausted to the outside through an exhaust port 405 provided above the substrate 403.

[0132] Regarding the thermal reaction, as long as the mist reacts by heating, the reaction conditions are not particularly limited. The raw materials can be appropriately selected according to the film to be formed. For example, the heating temperature is in the range of 120-600°C, preferably in the range of 200-600°C, and more preferably in the range of 300-550°C.

[0133] The thermal reaction can be carried out in any of a vacuum, non-oxygen atmosphere, reducing gas atmosphere, air atmosphere, and oxygen atmosphere, and can be appropriately selected depending on the film to be formed. Furthermore, the reaction pressure can be carried out under any conditions, including atmospheric pressure, increased pressure, or reduced pressure. Film formation under atmospheric pressure is preferred because it simplifies the apparatus structure.

[0134] In addition, the film forming method of the present invention is characterized in that, in the above-mentioned process of forming the mixed mist fluid, the angle formed by the flow vector of the additive fluid and the flow vector of the mixed mist fluid is less than 80 degrees, and the linear velocity of the additive fluid in the connecting part 301 is greater than the linear velocity of the carrier gas containing the mist.

[0135] At this time, if Figure 4 、 5 As shown in FIG. 1 , in the process of forming the mixed mist fluid, the angle between the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is set to be less than 80 degrees. In addition, when the angle between the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid is set to θ (degrees), the angle between the above-mentioned vectors B and C is equal to 180-θ.

[0136] (degrees) corresponds. That is, as described for the above-mentioned connection portion 301, the piping 303 for conveying the additive fluid and the piping 304 for conveying the mixed mist fluid are connected in such a manner that the angle θ formed therebetween is greater than 100 degrees, and the additive fluid and the mixed mist fluid are conveyed. In this case, if it is expressed as "the angle formed by the flow vector B of the additive fluid and the flow vector of the mixed mist fluid", it is less than 80 degrees. In the connection portion 301, the angle formed by the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid can be set to 60 degrees, or it can also be set to 0 degrees. In this way, the angle formed by the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is less than 80 degrees. In particular, it is preferably less than 60 degrees, and more preferably 0 degrees.

[0137] As long as the angle between the flow vector B of the additive fluid and the flow vector C of the mixed mist fluid is less than 80 degrees, the flow vector A (direction) of the carrier gas containing the mist is not limited (see Figure 6 、 7 ).

[0138] In addition, at this time, there is no particular limitation on the linear velocity of the additive fluid, as long as the linear velocity of the additive fluid in the connection portion 301 is greater than the linear velocity of the carrier gas containing mist. A linear velocity of 10 times or more can more significantly exert the effects of the present invention. In addition, there is no particular upper limit on the ratio of linear velocities. The faster the velocity of the additive fluid, the more significantly the effect of suppressing the decrease in film formation speed brought about by the structure of the present invention can be exerted. For example, the flow rate of the additive fluid and the flow rate of the carrier gas containing mist can be adjusted according to the cross-sectional area of ​​each pipe.

[0139] In this way, the reduction of mist caused by collision with the wall of the connection part can be further suppressed. In addition, by utilizing the injection effect to introduce the low-speed carrier gas containing mist into the high-speed additive fluid in the connection part 301, the mist can be transported stably, which can further increase the film formation speed.

[0140] In the present invention, annealing treatment may be performed after film formation. The annealing temperature is not particularly limited, but is preferably 600°C or lower, more preferably 550°C or lower. This is because it does not impair the crystallinity of the film. The annealing time is not particularly limited, but is preferably 10 seconds to 10 hours, more preferably 10 seconds to 1 hour.

[0141] Example

[0142] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0143] (Example 1)

[0144] First, refer to Figure 1The following describes the film forming apparatus 401 used in Example 1. The film forming apparatus 401 includes the following components: a carrier gas source 105a for supplying carrier gas; a flow control valve 105b for regulating the flow rate of the carrier gas delivered from the carrier gas source 105a; an additive fluid source 106a for supplying additive fluid; a flow control valve 106b for regulating the flow rate of gas in the additive fluid delivered from the additive fluid source 106a; a mist generating source 102 containing a raw material solution 102a; a container 103 containing water 103a; an ultrasonic oscillator 104 mounted on the bottom surface of the container 103; a film forming chamber 402; a pipe, a connection portion 301, and a mixed mist fluid delivery portion 107 connecting the mist generating source 102 to the film forming chamber 402; and a hot plate 404 disposed outside the film forming chamber 402.

[0145] In Example 1, Figure 4 In this way, the connection part 301 uses a T-shaped connection component 305, and the pipe 303 for conveying the additive fluid made of perfluoroalkoxyalkane (PFA) and the pipe 304 for conveying the mixed mist fluid are connected to the connection component 305 in a manner that the angle formed by these pipes is 180 degrees, and the pipe 302 for conveying the carrier gas containing mist made of PFA is connected to the connection component 305 in a manner that is 90 degrees relative to these pipes.

[0146] First, a raw material solution was prepared by adjusting a 0.05 mol / L aqueous solution of gallium iodide to contain a 48% hydroiodic acid solution at a volume ratio of 10%, and this was used as the raw material solution 102a.

[0147] The raw material solution 102a obtained as described above is contained in the mist generation source 102. Next, a c-plane sapphire substrate with a diameter of 4 inches (about 100 mm) is placed on a hot plate 404 in the film forming chamber 402 as the substrate 403. The hot plate 404 is operated to raise the temperature to 450°C.

[0148] Next, the flow rate control valve 105b was opened to supply carrier gas from the carrier gas source 105a into the film forming chamber 402. After the atmosphere in the film forming chamber 402 was fully replaced with the carrier gas, the flow rates of the carrier gas and the additive fluid were adjusted to 8 L / min and 40 L / min, respectively. Nitrogen was used for both the carrier gas and the additive fluid.

[0149] Next, the ultrasonic vibrator 104 is vibrated at 2.4 MHz and the vibration is passed through the water 103a.

[0150] The mist propagates toward the raw material solution 102a, atomizing it into a mist. This mist is transported to the connection 301 by a carrier gas, where it mixes with the additive fluid and is introduced into the film-forming chamber 402 via the mixed mist fluid transport unit 107. Furthermore, under atmospheric pressure and 450°C, the mist undergoes a thermal reaction within the film-forming chamber 402, forming a thin film of gallium oxide (α-Ga2O3) with a corundum structure on the substrate 403. The film formation time is 30 minutes.

[0151] The amount of reduction per unit time of the raw material solution 102a in the mist generation source 102 was defined as the time-averaged mist flow rate, and the time-averaged mist flow rate was measured and film formation was performed.

[0152] Regarding the thin film formed on the substrate 403 , the film thickness was measured at 17 points within the surface of the substrate 403 using a step profiler, and the average film thickness was calculated from the respective values.

[0153] The time-averaged mist flow rate is 3.2 g / min, the average film thickness is 660 nm, and the film-forming speed obtained by dividing the average film thickness by the film-forming time is 1320 nm / h.

[0154] (Example 2)

[0155] like Figure 5 In this way, a Y-shaped tube with θ=120 degrees is used as the connecting component 305a, so that the angle formed by the piping 303 for conveying the additive fluid and the piping 304 for conveying the mixed mist fluid, the angle formed by the piping 303 for conveying the additive fluid and the piping 302 for conveying the carrier gas containing mist, and the angle formed by the piping 304 for conveying the mixed mist fluid and the piping 302 for conveying the carrier gas containing mist are all 120 degrees. Except for this, the film is formed and evaluated in the same manner as in Example 1.

[0156] The time-averaged mist flow rate is 3.0 g / min, the average film thickness is 590 nm, and the film formation speed is 1180 nm / h.

[0157] (Comparative Example 1)

[0158] like Figure 13 In this way, using a T-shaped connecting component 305h with θ=90 degrees, the pipe 302 made of PFA for conveying a carrier gas containing mist and the pipe 304 for conveying a mixed mist fluid are connected to the connecting component 305h in a manner that the angle formed by these pipes is 180 degrees, and the pipe 303 made of PFA for conveying an additive fluid is connected in a manner that is 90 degrees relative to these pipes. Except for this, the film is formed and evaluated in the same manner as in Example 1.

[0159] The time-averaged mist flow rate is 1.7 g / min, the average film thickness is 230 nm, and the film formation speed is 460 nm / h.

[0160] (Example 3)

[0161] Film formation and evaluation were performed in the same manner as in Example 1, except that the carrier gas flow rate and the additive fluid flow rate were adjusted to 20 L / min and 5 L / min, respectively. The time-averaged mist flow rate was 4.6 g / min, the average film thickness was 1140 nm, and the film formation rate was 2280 nm / h.

[0162] (Comparative Example 2)

[0163] Film formation and evaluation were performed in the same manner as in Comparative Example 1, except that the carrier gas flow rate and the additive fluid flow rate were adjusted to 20 L / min and 5 L / min, respectively. The time-averaged mist flow rate was 2.7 g / min, the average film thickness was 540 nm, and the film formation rate was 1080 nm / h.

[0164] (Example 4)

[0165] Film formation and evaluation were performed in the same manner as in Example 1, except that the carrier gas flow rate and the additive fluid flow rate were adjusted to 2 L / min and 50 L / min, respectively, and the film formation time was set to 120 minutes. The time-averaged mist flow rate was 0.7 g / min, the average film thickness was 280 nm, and the film formation rate was 140 nm / h.

[0166] (Comparative Example 3)

[0167] Film formation and evaluation were performed in the same manner as in Comparative Example 1, except that the carrier gas flow rate and the additive fluid flow rate were adjusted to 2 L / min and 50 L / min, respectively, and the film formation time was set to 120 minutes. The time-averaged mist flow rate was 0.1 g / min, the average film thickness was 60 nm, and the film formation rate was 30 nm / h.

[0168] Table 1 summarizes the results of Examples 1 to 4 and Comparative Examples 1 to 3.

[0169] [Table 1]

[0170]

[0171] By comparing Examples 1 to 4 with Comparative Examples 1 to 3, it can be seen that by making the angle between the piping for conveying the additive fluid and the piping for conveying the mixed mist fluid greater than 120 degrees, the time-averaged mist flow rate is greatly improved, and the film formation speed is also greatly improved.

[0172] (Example 5)

[0173] In Example 5, the same film-forming apparatus 401 as that used in Example 1 was used. The following describes the differences from Example 1.

[0174] In Example 5, Figure 9 In this way, the connection part 301 uses a T-shaped connection component 305e, and the pipe 303 for conveying the additive fluid and the pipe 304 for conveying the mixed mist fluid made of perfluoroalkoxyalkane (PFA) are connected to the connection component 305e so that the angle between these pipes is 180 degrees. The pipe 302 for conveying the carrier gas containing the mist made of PFA is connected to the connection component 305e at a 90-degree angle relative to these pipes. At this time, when the cross-sectional area S of the portion of the connection component 305e connected to the pipe 303 for conveying the additive fluid is B The cross-sectional area S of the portion of the connecting member 305e connected to the pipe 302 for conveying the carrier gas containing mist is A The ratio is set as α(=S A / S B ), α is 20. In this case, the inner diameter of the portion where the connecting component 305e is connected to the pipe 303 for conveying the additive fluid is 0.4 cm, and the inner diameter of the portion where the connecting component 305e is connected to the pipe 302 for conveying the carrier gas containing mist is 3.6 cm.

[0175] First, a raw material solution was prepared by adjusting a 0.05 mol / L aqueous solution of gallium iodide to contain a 48% hydroiodic acid solution at a volume ratio of 10%, and this was used as the raw material solution 102a.

[0176] The raw material solution 102a obtained as described above is contained in the mist generation source 102. Next, a c-plane sapphire substrate with a diameter of 4 inches (about 100 mm) is placed on a hot plate 404 in the film forming chamber 402 as the substrate 403. The hot plate 404 is operated to raise the temperature to 450°C.

[0177] Next, the flow rate control valve 105b was opened to supply carrier gas from the carrier gas source 105a into the film forming chamber 402. After the atmosphere in the film forming chamber 402 was fully replaced with the carrier gas, the flow rates of the carrier gas and the additive fluid were adjusted to 8 L / min and 4 L / min, respectively. Nitrogen was used for both the carrier gas and the additive fluid.

[0178] Next, the ultrasonic vibrator 104 is vibrated at 2.4 MHz and the vibration is passed through the water 103a.

[0179] The mist propagates toward the raw material solution 102a, atomizing the raw material solution 102a to generate a mist. This mist is transported to the connection section 301 by a carrier gas, mixed with the additive fluid within the connection section 301, and introduced into the film formation chamber 402 via the mixed mist fluid transport section 107. Furthermore, under atmospheric pressure and 450°C, the mist undergoes a thermal reaction within the film formation chamber 402, forming a thin film of gallium oxide (α-Ga2O3) with a corundum structure on the substrate 403. The film formation time is 60 minutes.

[0180] The amount of reduction per unit time of the raw material solution 102a in the mist generation source 102 was defined as the time-averaged mist flow rate, and the time-averaged mist flow rate was measured and film formation was performed.

[0181] The film thickness of the thin film formed on the substrate 403 was measured at 17 points on the substrate 403 using a step profiler. The average film thickness was calculated from the respective values. The film formation rate was calculated by dividing the average film thickness by the film formation time.

[0182] (Examples 6 to 8)

[0183] Film formation was carried out in the same manner as in Example 5 except that the flow rate of the addition fluid was changed to 10, 20, and 40 L / min.

[0184] (Comparative Example 4)

[0185] Use as Figure 13 The T-shaped connecting component 305h with θ=90 degrees is used. The pipe 302 made of PFA for conveying the carrier gas containing mist and the pipe 304 for conveying the mixed mist fluid are connected to the connecting component 305h in such a manner that the angle formed by these pipes is 180 degrees, and the pipe 303 made of PFA for conveying the additive fluid is connected in such a manner that it forms 90 degrees relative to these pipes. Except for this, the film is formed and evaluated in the same manner as in Example 5.

[0186] (Comparative Examples 5 to 7)

[0187] Film formation was carried out in the same manner as in Comparative Example 4 except that the flow rate of the addition fluid was changed to 10, 20, and 40 L / min.

[0188] (Example 9)

[0189] The shape of the connecting member 305 is changed so that the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid is smaller than B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist AFilm formation was carried out in the same manner as in Example 5, except that the ratio α was set to 1 and the flow rate of the additive fluid was set to 8 L / min. Furthermore, at this time, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 1.8 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing the mist was 1.8 cm.

[0190] (Comparative Example 8)

[0191] The shape of the connecting member 305 is changed so that the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid is smaller than B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Comparative Example 4, except that the ratio α was set to 1 and the flow rate of the additive fluid was set to 8 L / min. Furthermore, at this time, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 1.8 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing the mist was 1.8 cm.

[0192] (Example 10)

[0193] The shape of the connecting member 305 is changed so that the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid is smaller than B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Example 5, except that the ratio α was set to 50 and the flow rate of the additive fluid was set to 24 L / min. Furthermore, at this time, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 0.8 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing the mist was 5.6 cm.

[0194] (Comparative Example 9)

[0195] The shape of the connecting member 305 is changed so that the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid is smaller than B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Comparative Example 4, except that the ratio α was set to 50 and the flow rate of the additive fluid was set to 24 L / min. Furthermore, at this time, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 0.8 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing mist was 5.6 cm.

[0196] (Example 11)

[0197] like Figure 5 In this way, a Y-shaped tube with θ=120 degrees is used as the connecting component 305a, so that the angle formed by the piping 303 for conveying the additive fluid and the piping 304 for conveying the mixed mist fluid, the angle formed by the piping 303 for conveying the additive fluid and the piping 302 for conveying the carrier gas containing mist, and the angle formed by the piping 304 for conveying the mixed mist fluid and the piping 302 for conveying the carrier gas containing mist are all 120 degrees. Except for this, the film is formed and evaluated in the same manner as in Example 5.

[0198] (Example 12)

[0199] The film was formed in the same manner as in Example 11 except that the flow rate of the addition fluid was changed to 40 L / min.

[0200] (Example 13)

[0201] like Figure 10 In this way, a Y-shaped tube with θ=100 degrees is used as the connecting component 305f, so that the angle formed by the piping 303 for conveying the additive fluid and the piping 304 for conveying the mixed mist fluid is 100 degrees, and the angle formed by the piping 303 for conveying the additive fluid and the piping 302 for conveying the carrier gas containing mist, and the angle formed by the piping 304 for conveying the mixed mist fluid and the piping 302 for conveying the carrier gas containing mist are both 130 degrees. Except for this, the film is formed and evaluated in the same manner as in Example 5.

[0202] (Example 14)

[0203] Film formation was carried out in the same manner as in Example 13 except that the flow rate of the addition fluid was changed to 10 L / min.

[0204] Table 2 summarizes the results of Examples 5 to 14 and Comparative Examples 4 to 9. In addition, the piping angle represents the angle between the piping for conveying the additive fluid and the piping for conveying the mixed mist fluid, and the linear velocity ratio represents the value obtained by dividing the linear velocity of the additive fluid by the linear velocity of the carrier gas. Figure 11 、 Figure 12 Graphs in which the time-averaged mist flow rate and the film-forming speed are plotted against the linear speed ratio are shown.

[0205] [Table 2]

[0206]

[0207] (Example 15)

[0208] A sapphire substrate with a diameter of 6 inches (150 mm) was used, and the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Example 5, except that the ratio α was set to 1, and the flow rates of the carrier gas and the additive fluid were both set to 20 L / min. At this time, the linear velocity ratio was 1, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for supplying the additive fluid was 2.6 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for supplying the carrier gas containing mist was 2.6 cm. Furthermore, the time-averaged mist flow rate was 4.65 g / min, and the film formation rate was 1.42 μm / hr.

[0209] (Example 16)

[0210] A sapphire substrate with a diameter of 6 inches (150 mm) was used, and the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Example 11, except that the ratio α was set to 1, and the flow rates of the carrier gas and the additive fluid were both set to 20 L / min. At this time, the linear velocity ratio was 1, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 2.6 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing mist was 2.6 cm. Furthermore, the time-averaged mist flow rate was 4.25 g / min, and the film formation rate was 1.26 μm / hr.

[0211] (Example 17)

[0212] A sapphire substrate with a diameter of 6 inches (150 mm) was used, and the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Example 13, except that the ratio α was set to 1, and the flow rates of the carrier gas and the additive fluid were both set to 20 L / min. In this case, the linear velocity ratio was 1, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 2.6 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing mist was 2.6 cm. Furthermore, the time-averaged mist flow rate was 4.04 g / min, and the film formation rate was 1.06 μm / hr.

[0213] (Comparative Example 10)

[0214] A sapphire substrate with a diameter of 6 inches (150 mm) was used, and the cross-sectional area S of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was B , the cross-sectional area S of the portion of the connecting component 305 connected to the pipe 302 for conveying the carrier gas containing mist A Film formation was carried out in the same manner as in Comparative Example 4, except that the ratio α was set to 1 and the flow rates of the carrier gas and the additive fluid were both set to 20 L / min. In this case, the linear velocity ratio was 1, the inner diameter of the portion of the connecting member 305 connected to the pipe 303 for conveying the additive fluid was 2.6 cm, and the inner diameter of the portion of the connecting member 305 connected to the pipe 302 for conveying the carrier gas containing mist was 2.6 cm. Furthermore, the time-averaged mist flow rate was 1.81 g / min, and the film formation rate was 0.43 μm / hr.

[0215] By comparing Examples 5 to 14 with Comparative Examples 4 to 9, and Examples 15 to 17 with Comparative Example 10, it can be seen that by making the angle between the piping for conveying the additive fluid and the piping for conveying the mixed mist fluid greater than 100 degrees, and making the linear velocity of the additive fluid greater than the linear velocity of the carrier gas, the time-averaged mist flow rate is greatly improved, and the film formation speed is also greatly improved.

[0216] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration having substantially the same structure and achieving the same function and effect as the technical concept described in the claims of the present invention is encompassed within the technical scope of the present invention.

Claims

1. A film forming device, characterized in that: At least: an atomizing section for atomizing the raw material solution to generate mist; a pipe connected to the atomizing portion and conveying a carrier gas containing the mist; at least one pipe for conveying an additive fluid containing one or more gases as main components and mixed with the carrier gas containing the mist; a pipe connected to the film forming unit and conveying a mixed mist fluid obtained by mixing the carrier gas containing the mist and the adding fluid; a connecting member connecting a pipe for conveying a carrier gas containing the mist, a pipe for conveying the additive fluid, and a pipe for conveying the mixed mist fluid; as well as a film forming unit that heat-treats the mist to form a film on a substrate, The angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid connected by the connecting component is greater than 120 degrees. The linear velocity of the adding fluid is set to 1 to 100 times the linear velocity of the carrier gas containing the mist, and the flow rate of the carrier gas is set to 8 L / min or more.

2. The film forming device according to claim 1, wherein: The angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid is 180 degrees.

3. A film forming device, characterized in that: At least: an atomizing section for atomizing the raw material solution to generate mist; a pipe connected to the atomizing portion and conveying a carrier gas containing the mist; at least one pipe for conveying an additive fluid containing one or more gases as main components and mixed with the carrier gas containing the mist; a pipe connected to the film forming unit and conveying a mixed mist fluid obtained by mixing the carrier gas containing the mist and the adding fluid; a connecting member connecting a pipe for conveying a carrier gas containing the mist, a pipe for conveying the additive fluid, and a pipe for conveying the mixed mist fluid; as well as a film forming unit that heat-treats the mist to form a film on a substrate, The angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid connected by the connecting component is greater than 100 degrees. The linear velocity of the adding fluid in the connection portion connected by the connection member is set to be greater than the linear velocity of the carrier gas containing the mist, The flow rate of the carrier gas is set to 8 L / min or more.

4. The film forming device according to claim 3, wherein: The angle formed by the pipe for conveying the additive fluid and the pipe for conveying the mixed mist fluid is greater than or equal to 120 degrees.

5. The film forming device according to claim 3, wherein: The linear velocity of the adding fluid in the connecting portion is set to be 10 times or more the linear velocity of the carrier gas containing the mist.

6. The film forming device according to claim 4, wherein: The linear velocity of the adding fluid in the connecting portion is set to be 10 times or more the linear velocity of the carrier gas containing the mist.

7. The film forming apparatus according to any one of claims 1 to 6, wherein: The cross-sectional area of ​​a portion of the connecting member connected to the pipe for conveying the additive fluid is equal to or smaller than the cross-sectional area of ​​a portion of the connecting member connected to the pipe for conveying the carrier gas containing the mist.

8. The film forming apparatus according to any one of claims 1 to 6, wherein: As the substrate, the processing area is 10cm 2 The above matrix.

9. A film forming method, characterized in that: The process includes the following steps: Atomizing the raw material solution in the atomizing section to generate mist; supplying a carrier gas to the atomizing section and delivering the carrier gas containing mist from the atomizing section; Mixing the carrier gas containing the mist and at least one additional fluid containing one or more gases as main components to form a mixed mist fluid; delivering the mixed mist fluid to a film forming part; as well as In the film forming unit, the mist in the mixed mist fluid is heat-treated to form a film on the substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additional fluid and the flow vector of the mixed mist fluid is set to be less than 60 degrees. The linear velocity of the adding fluid is set to 1 to 100 times the linear velocity of the carrier gas containing the mist, and the flow rate of the carrier gas is set to 8 L / min or more.

10. The film forming method according to claim 9, wherein: The angle formed by the flow vector of the adding fluid and the flow vector of the mixed mist fluid is set to 0 degrees.

11. A film forming method, characterized in that: The process includes the following steps: Atomizing the raw material solution in the atomizing section to generate mist; supplying a carrier gas to the atomizing section and delivering the carrier gas containing mist from the atomizing section; Mixing the carrier gas containing the mist and at least one additional fluid containing one or more gases as main components to form a mixed mist fluid; delivering the mixed mist fluid to a film forming part; as well as In the film forming unit, the mist in the mixed mist fluid is heat-treated to form a film on the substrate. In the step of forming the mixed mist fluid, the angle formed by the flow vector of the additional fluid and the flow vector of the mixed mist fluid is set to be 80 degrees or less. In the step of forming the mixed mist fluid, the linear velocity of the additive fluid is set to be greater than the linear velocity of the carrier gas containing the mist. The flow rate of the carrier gas is set to 8 L / min or more.

12. The film forming method according to claim 11, wherein: The angle formed by the flow vector of the adding fluid and the flow vector of the mixed mist fluid is set to be 60 degrees or less.

13. The film forming method according to claim 11, wherein In the step of forming the mixed mist fluid, the linear velocity of the adding fluid is set to be 10 times or more the linear velocity of the carrier gas containing the mist.

14. The film forming method according to claim 12, wherein: In the step of forming the mixed mist fluid, the linear velocity of the adding fluid is set to be 10 times or more the linear velocity of the carrier gas containing the mist.

15. The film forming method according to any one of claims 9 to 14, characterized in that: As the substrate, the usable area is 10cm 2 The above matrix.

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