Thermal spray device and thermal spray method

Abstract

To suppress influence from fume on a target on a thermal spray device.SOLUTION: A thermal spraying device for depositing a film by jetting melted power to a target T includes: a chamber of which interior is decompressed; a holder stored in the chamber to hold the target; a thermal spray gun for jetting powder to the target that is held by the holder; and a thermal spray gun cover which is disposed between the thermal spray gun and the holder and in which an opening 33 through which the powder jetted from the thermal spray gun passes is formed.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present invention relates to a thermal spraying apparatus and a thermal spraying method. [Background technology]

[0002] A thermal spraying device melts powder material and sprays it onto a target such as a substrate to form a film on the target (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 61-259778 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to suppress the effect of fumes on a target in a thermal spraying device. [Means for solving the problem]

[0005] [1] A thermal spraying apparatus according to one embodiment of the present invention comprises: A thermal spraying device that forms a coating by spraying molten powder onto a target, a chamber having an internal pressure reduced; a holder accommodated in the chamber and holding the target; a thermal spray gun that sprays powder onto the target held by the holder; a spray gun cover disposed between the spray gun and the holder and having an opening through which powder sprayed from the spray gun passes; Equipped with.

[0006] [2] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to the above item [1], The diameter of the opening formed in the thermal spray gun cover is set according to the distance from the thermal spray gun to the target.

[0007] [3] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to the above [1] or [2], The distance between the surface of the thermal spray gun cover facing the target and the target is 10 mm or less.

[0008] [4] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to any one of the above items [1] to [3], The thermal spray gun cover has an exhaust mechanism for exhausting gas containing particles that is generated when powder is sprayed from the thermal spray gun.

[0009] [5] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus described in [4] above, The thermal spray gun cover has, as the exhaust mechanism, a first exhaust port formed in a position facing a side surface of the thermal spray gun.

[0010] [6] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to the above [4] or [5], The thermal spray gun cover has, as the exhaust mechanism, a second exhaust port formed in a position facing the underside of the thermal spray gun, and an exhaust path through which gas that has passed through the second exhaust port passes.

[0011] [7] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to the above [4] or [5], The thermal spray apparatus of claim 6 , wherein the second exhaust port includes a plurality of holes.

[0012] [8] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus according to the above item [7], The plurality of holes are formed radially with respect to the center of the opening of the thermal spray gun cover.

[0013] [9] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus described in [1] to [8] above, The holder has a cooling structure for cooling the target.

[0014]

[10] The thermal spraying apparatus according to one aspect of the present invention is the thermal spraying apparatus described in [9] above, The holder includes a flow path for a coolant as the cooling structure.

[0015]

[11] A thermal spraying method according to one embodiment of the present invention comprises: A thermal spraying method for forming a coating by spraying molten powder onto a target, comprising the steps of: reducing the pressure inside the chamber; holding the target with a holder housed in the chamber; Injecting powder from the thermal spray gun toward the target through an opening in a thermal spray gun cover disposed between the thermal spray gun and the holder; Includes. Effect of the Invention

[0016] In a thermal spraying device, the effect of fumes on a target can be suppressed. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic configuration diagram of a thermal spraying device according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a configuration of a thermal spray gun cover in a thermal spray device according to one embodiment. [Figure 3A] FIG. 1 is a conceptual diagram showing the distribution of powder on a target surface sprayed without using a thermal spray gun cover. [Figure 3B] FIG. 2 is a conceptual diagram showing the distribution of powder sprayed on a target surface through a thermal spray gun cover. [Figure 4] FIG. 4 is a diagram illustrating a stage cooling structure of a thermal spraying device according to an embodiment. [Diagram 5] 4A and 4B are diagrams for explaining the stage cooling structure in more detail. [Figure 6] 5A to 5C are diagrams illustrating the effect of a stage cooling structure of a holder. [Figure 7] FIG. 2 is a diagram illustrating a configuration of a thermal spray gun cover in a thermal spray device according to one embodiment. [Figure 8A] FIG. 2 is a diagram showing an example of the upper surface of a thermal spray gun cover of a thermal spray apparatus according to an embodiment. [Figure 8B] FIG. 2 is a diagram showing an example of the upper surface of a thermal spray gun cover of a thermal spray apparatus according to an embodiment. [Figure 8C] FIG. 2 is a diagram showing an example of the upper surface of a thermal spray gun cover of a thermal spray apparatus according to an embodiment. [Figure 8D] FIG. 2 is a diagram showing an example of the upper surface of a thermal spray gun cover of a thermal spray device according to an embodiment. [Figure 9A] FIG. 2 is a diagram illustrating an example of a scanning mode of a thermal spraying device according to an embodiment. [Figure 9B] FIG. 2 is a diagram illustrating an example of a scanning mode of a thermal spraying device according to an embodiment. [Figure 10] FIG. 1 is a diagram for explaining the diffusion of fumes in a conventional thermal spraying device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

[0019] (First embodiment) 1 is a schematic diagram of a thermal spraying device 1 according to one embodiment. The thermal spraying device 1 includes a thermal spraying gun 2, a thermal spraying gun cover 3 that covers the periphery of the thermal spraying gun 2, a heat exchanger 4 that exchanges heat with the gas discharged from the thermal spraying gun cover 3, a foreline trap 5 that captures fumes from the gas that has passed through the heat exchanger 4, a holder 6 that holds a target to be sprayed by the thermal spraying gun 2, a chamber 7 that houses the holder 6, and an exhaust pump 8 that reduces the pressure inside the chamber 7.

[0020] This thermal spraying device 1 melts powder from a thermal spraying gun 2 and sprays (thermal sprays) it onto the target, thereby forming a film on a target T held by a holder 6 in a chamber 7. As an example, the target T is a disk-shaped wafer (substrate).

[0021] Powder is supplied to the thermal spray gun 2 from a powder supply unit (not shown) using a powder carrier gas (argon, nitrogen, etc.). Then, a material derived from this powder is formed into a film on the target T. As an example, the powder is copper powder, and a copper thin film is formed on the target T.

[0022] The thermal spray gun 2 is composed of a cathode 21, an anode 22, etc. The cathode 21 is disposed downstream (below) of the powder supply section. A cavity is formed inside the cathode 21, and the powder from the powder supply section passes through the cavity via a powder guide path.

[0023] The anode 22 is disposed downstream (below) of the cathode 21 and spaced apart from the cathode 21. A cavity is formed inside the anode 22. This cavity is located below the cavity of the cathode 21 and above the opening on the bottom surface of the body of the thermal spray gun 2. The powder from the cathode 21 passes through the inside of the cavity in the anode 22.

[0024] A plasma generation supporting gas is supplied from a plasma generation supporting gas supply unit (not shown) to the inside of the thermal spray gun 2. The plasma generation supporting gas may be, for example, argon or argon with added hydrogen, or may be a gas required for use in the process, such as neon, helium, or nitrogen.

[0025] With plasma generation support gas supplied to the interior of the thermal spray gun 2, a voltage is applied from a power supply unit (not shown) so that a high potential difference is generated between the cathode 21 and the anode 22. This generates an arc discharge between the cathode 21 and the anode 22. The arc discharge generates plasma between the cathode 21 and the anode 22, and the powder from the powder supply unit is melted (liquefied) by the heat. The molten powder (liquid powder) is sprayed onto the target T, where a film is formed.

[0026] The spray gun cover 3 is a member that covers the periphery of the spray gun 2, and prevents the diffusion of fumes (fine particles derived from the spray material) that are generated along with the plasma flame during thermal spraying by the spray gun 2. Specifically, by installing the spray gun cover 3, the heat of the plasma is trapped inside the spray gun cover 3, reducing the temperature difference near the boundary surface of the plasma flame. This makes it possible to suppress the generation of fumes.

[0027] 2, the thermal spray gun cover 3 has an exhaust port 31H formed at a position facing the side surface of the thermal spray gun 2, a local exhaust path 31L formed in communication with this exhaust port 31H, and a bottom plate 32. An opening 33 is formed in the bottom plate 32, and the plasma flame sprayed from the thermal spray gun 2 during thermal spraying is configured to pass through this opening 33. During thermal spraying, gas containing fumes generated together with the plasma flame is sucked into the exhaust port 31H of the thermal spray gun cover 3 and discharged to the outside of the chamber 7 through the local exhaust path 31L.

[0028] The shorter the distance D between the surface of the bottom plate 32 of the thermal spray gun cover 3 facing the target and the target, the more the adhesion of fumes to the target surface can be prevented, but in practice it is 10 mm or less, and more preferably 5 to 10 mm. Note that when the thermal spray gun cover 3 is brought close to the target T, heat may be trapped between the thermal spray gun cover 3 and the target T, causing thermal damage to the target T. However, in this embodiment, the holder 6 is provided with a stage cooling structure 62 described below, so that thermal damage to the target T is suppressed.

[0029] Fig. 3A is a conceptual diagram showing the distribution (powder distribution) of powder (copper, as an example) sprayed on the target surface without using a thermal spray gun cover. As shown in Fig. 3A, the powder sprayed from the thermal spray gun 3 is distributed on the target surface in a substantially Gaussian distribution. Fumes (copper oxide, etc.) are distributed at the base of the distribution.

[0030] Fig. 3B is a conceptual diagram showing the distribution (powder distribution) of powder sprayed through a thermal spray gun cover on the target surface. As shown in Fig. 3B, when thermal spraying is performed through a thermal spray gun cover, fumes are blocked by the bottom plate 32 of the thermal spray gun cover 3, and adhesion of the fumes to the target surface can be prevented. This makes it possible to form a film with good film quality on the target surface. The fumes that have adhered to the upper surface of the bottom plate 32 are removed during maintenance (cleaning) of the thermal spraying device 1.

[0031] Here, the diameter Φ of the opening 33 formed in the bottom plate 32 will be described. The diameter Φ of the opening 33 is set according to the distance from the thermal spray gun to the target T (working distance WD) (see FIG. 2). Specifically, the longer the working distance WD, the broader the powder distribution, so the diameter Φ of the opening 33 is set to be larger. Conversely, the shorter the working distance WD, the steeper the powder distribution, so the diameter Φ of the opening 33 is set to be smaller. Also, as shown in FIG. 3A, fumes adhere to the target surface in the region at the base of the powder distribution, so setting the diameter Φ of the opening 33 to the size of 3σ (σ: standard deviation) of the powder distribution can effectively prevent fumes from adhering to the target surface.

[0032] Returning to Fig. 1, the gas containing fumes that has passed through the local exhaust path 31 of the thermal spray gun cover 3 is sucked by the exhaust pump 8 via the heat exchanger 4 and the foreline trap 5. By passing through the heat exchanger 4 in this way, it is possible to prevent the exhaust pump 8 from directly sucking in the high-temperature gas exhausted from the local exhaust path 31 and causing a breakdown.

[0033] The chamber 7 is disposed below the thermal spray gun 2. An opening is provided on the upper surface of the chamber 7 and is aligned with the opening on the lower surface of the thermal spray gun 2.

[0034] The holder 6 is disposed below the opening of the chamber 7 and holds a target T. The holder 6 includes a stage 61 that adsorbs and holds a target (e.g., a wafer), a stage cooling structure 62 that cools the stage 61, and an XY stage 63 that moves the stage 61 and the stage cooling structure 62 together within a horizontal plane (within the XY plane).

[0035] Fig. 4 is a diagram illustrating a schematic configuration of a stage cooling structure 62 of a thermal spraying apparatus according to this embodiment. As shown in Fig. 4, the holder 6 has a flow path L therein as the stage cooling structure 62. Then, a coolant (e.g., a high-boiling point coolant such as Galden) circulated by a coolant chiller installed outside the chamber 7 flows through this flow path L, thereby cooling the stage 61, and thus the target T placed on the stage 61 is cooled.

[0036] 5, the stage cooling structure 62 has a thermocouple TC that measures the back surface temperature of the target T (e.g., a wafer). During thermal spraying onto the target T, as shown in Fig. 9A and Fig. 9B, powder is uniformly sprayed onto the target surface in a predetermined repeating pattern (e.g., 1 / 4λ intervals), so that the target T becomes hot due to the sprayed powder, but in this embodiment, the target T is cooled by the stage cooling structure 62, so that thermal damage to the target T can be reduced.

[0037] Fig. 6 is a diagram showing an example of the cooling effect of the stage cooling structure 62. As shown in Fig. 6, when the stage cooling structure 62 is employed, the back surface temperature of the target T can be suppressed to a temperature rise of about the coolant temperature + 100°C, and the temperature rise of the target T can be significantly suppressed compared to the case of "no cooling." This makes it possible to suppress thermal damage to the target T even if heat is trapped between the thermal spray gun cover 3 and the target T.

[0038] 10 is a diagram illustrating a thermal spraying device according to a comparative example. In this comparative example, a thermal spraying gun cover that covers the periphery of the thermal spraying gun 2 is not provided, so that fumes generated during thermal spraying adhere to the target T, impairing the film quality, and the fumes diffuse inside the chamber 7, contaminating the inner wall of the chamber. Furthermore, there is a risk that the fumes will peel off and scatter from the contaminated inner wall of the chamber, causing the fumes to get mixed into the film being formed on the surface of the target T, deteriorating the film quality.

[0039] In contrast, the thermal spraying apparatus 1 of this embodiment is equipped with a chamber 7 with a reduced pressure inside, a holder 6 housed in the chamber 7 and holding a target T, a thermal spraying gun 2 that sprays powder onto the target T held by the holder 6, and a thermal spraying gun cover 3 that is positioned between the thermal spraying gun 2 and the holder 6 and has an opening 33 through which the powder sprayed from the thermal spraying gun 2 passes, thereby preventing fumes from adhering to the target T and the inner wall of the chamber 7.

[0040] This makes it possible to reduce equipment downtime by making the thermal spraying device 1 maintenance-free, and to reduce adverse effects of chamber contamination on film quality during deposition. In addition, by suppressing the inclusion of fumes in the film during deposition, film quality can be preserved.

[0041] In addition, by trapping heat inside the thermal spray gun cover 3, the power required to maintain the plasma can be reduced, and thus wear on the cathode (eg, tungsten) can be reduced.

[0042] Second embodiment Next, a thermal spraying device 1 according to a second embodiment will be described. The second embodiment differs from the first embodiment in that an exhaust port and an exhaust path are provided in the bottom plate 32 of the thermal spraying gun cover 3.

[0043] 7 is a diagram for explaining a schematic configuration of the thermal spray gun cover 3 according to the second embodiment. As shown in FIG. 7, the thermal spray gun cover 3 according to this embodiment has an exhaust port 32H formed in the bottom plate 32 and a local exhaust path 32L formed inside the bottom plate 32. Here, the exhaust port 32H is arranged so as to correspond to the position of the foot of the distribution of the powder sprayed from the thermal spray gun 2 (the Fume area in FIG. 3A). That is, fumes localized at the foot of the powder distribution during thermal spraying pass through the exhaust port 32H of the bottom plate 32 and are guided to the local exhaust path 32L formed inside the bottom plate 32. The fumes guided to the local exhaust path 32L are sucked by a local exhaust pump and discharged to the outside of the chamber 7.

[0044] 8A to 8D are diagrams showing an example of exhaust port 32H formed on the upper surface of bottom plate 32. As shown in Fig. 8A, a plurality of circular holes may be provided as exhaust port 32H in point symmetry with respect to the center of opening 33.

[0045] Alternatively, as shown in FIG. 8B, a plurality of elliptical holes extending in the circumferential direction may be provided as exhaust ports 32H in point symmetry with respect to the center of opening 33 as the reference.

[0046] As shown in FIG. 8C, a plurality of elliptical holes extending in the radial direction may be provided as exhaust ports 32H radially from the center of opening 33 as a reference.

[0047] As shown in FIG. 8D, exhaust ports 32H may be formed by dividing a plurality of radially extending elliptical holes in the radial direction and providing them radially with respect to the center of opening 33 as the reference.

[0048] Thus, the thermal spraying apparatus 1 of this embodiment includes a chamber 7 with a reduced pressure inside, a holder 6 housed in the chamber 7 and holding a target T, a thermal spray gun 2 that sprays powder at the target T held by the holder 6, and a thermal spray gun cover 3 that is arranged between the thermal spray gun 2 and the holder 6 and has an opening 33 through which the powder sprayed from the thermal spray gun 2 passes.In addition, the thermal spray gun cover 3 has, as an exhaust mechanism, an exhaust port 32H formed in a position facing the underside of the thermal spray gun, and an exhaust path 32L through which gas that has passed through the exhaust port 32H passes, so that adhesion of fumes to the target T and the inner wall of the chamber 7 can be more effectively prevented.

[0049] Based on the above description, a person skilled in the art may be able to conceive additional effects and various modifications of the present invention, but the aspects of the present invention are not limited to the individual embodiments described above. Various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and intent of the present invention derived from the contents defined in the claims and their equivalents.

[0050] For example, what is described in this specification as one device (or member, the same applies below) (including what is depicted in the drawings as one device) may be realized by multiple devices. Conversely, what is described in this specification as multiple devices (including what is depicted in the drawings as multiple devices) may be realized by one device. Alternatively, some or all of the means or functions included in one device may be included in another device.

[0051] Furthermore, not all of the features described in this specification are essential requirements, and in particular, any feature described in this specification but not included in the claims may be considered as optional additional features.

[0052] It should be noted that the applicant is merely aware of the inventions disclosed in the documents in the "Prior Art Documents" column of this specification, and the present invention does not necessarily aim to solve the problems of the inventions disclosed in the documents. The problems that the present invention aims to solve should be identified by taking into consideration the entire specification. For example, if the specification states that a specific effect is achieved by a specific configuration, it can also be said that the problem that is the reverse of the specific effect is solved. However, it is not necessarily intended that such a specific configuration is an essential requirement. [Explanation of symbols]

[0053] 1 Thermal spraying equipment 2 Thermal spray gun 3 Thermal spray gun cover 31H Exhaust port (1st exhaust port) 31L Local exhaust passage 32 Bottom plate 32H Exhaust port (second exhaust port) 32L Local exhaust passage 33 Opening 4 Heat exchanger 5. Foreline Trap 6 Holder 61 Stages 62 Stage cooling structure 7. Chamber 8 Exhaust pump

Claims

1. A thermal spraying device that forms a coating by spraying molten powder onto a target, a chamber having an internal pressure reduced; a holder accommodated in the chamber and holding the target; a thermal spray gun that sprays powder onto the target held by the holder; a spray gun cover disposed between the spray gun and the holder and having an opening through which powder sprayed from the spray gun passes; A thermal spraying apparatus comprising:

2. The thermal spraying device according to claim 1 , wherein a diameter of the opening formed in the thermal spraying gun cover is set according to a distance from the thermal spraying gun to the target.

3. 3. The thermal spraying apparatus according to claim 1, wherein a distance between the target and a surface of the thermal spray gun cover facing the target is 10 mm or less.

4. The thermal spraying apparatus according to claim 1 , wherein the thermal spray gun cover has an exhaust mechanism for exhausting gas containing particles generated when powder is sprayed from the thermal spray gun.

5. The thermal spraying apparatus according to claim 4 , wherein the thermal spray gun cover has, as the exhaust mechanism, a first exhaust port formed at a position facing a side surface of the thermal spray gun.

6. The thermal spraying apparatus according to claim 5, wherein the thermal spray gun cover has, as the exhaust mechanism, a second exhaust port formed at a position facing the lower surface of the thermal spray gun, and an exhaust path through which gas that has passed through the second exhaust port passes.

7. The thermal spray apparatus of claim 6 , wherein the second exhaust port includes a plurality of holes.

8. The thermal spraying device according to claim 7 , wherein the plurality of holes are formed radially with respect to a center of the opening of the thermal spray gun cover.

9. The thermal spray apparatus of claim 1 , wherein the holder has a cooling structure for cooling the target.

10. The thermal spraying apparatus according to claim 9 , wherein the holder has a flow path for a coolant as the cooling structure.

11. A thermal spraying method for forming a coating by spraying molten powder onto a target, comprising the steps of: reducing the pressure inside the chamber; holding the target with a holder housed in the chamber; Injecting powder from the thermal spray gun toward the target through an opening in a thermal spray gun cover disposed between the thermal spray gun and the holder; A thermal spraying method comprising:

Images