JP2020132895A - Method for regenerating oxide film of component made of aluminum - Google Patents

Abstract

To provide a method for generating an oxide film of a component made of aluminum capable of regenerating an oxide film of a component made of aluminum.SOLUTION: A method for regenerating an oxide film of a component made of aluminum containing a component body made of aluminum or an aluminum ally and an oxide film formed on a surface of the component body comprises: a removal step where an upper layer part of a part or the whole in an oxide film of the component made of aluminum is removed, or removal is performed with a part of the oxide film left; and a regeneration step where the component made of aluminum passed through the removal step is immersed into an electrolytic solution and is subjected to microarc oxidation treatment to increase thickness of the oxide film at the removed part.SELECTED DRAWING: None

Description

The present invention relates to a method for regenerating an oxide film of an aluminum part.

Sputtering film deposition equipment as a device for manufacturing semiconductor devices such as memories and light emitting diodes, display devices such as liquid crystal display devices and organic EL display devices (also called flat panel displays), solar cells, magnetic devices, optical films, etc. Various manufacturing devices such as a CVD (Chemical Vaper Deposition), a vacuum vapor deposition device, an ashing device, an etching device, an ion injection device, and an annealing device are known. These manufacturing apparatus have a chamber for accommodating the base material to be processed and for performing film formation, etching, ion implantation, annealing, etc. on the base material. The chamber is provided with various parts for smooth film formation, etching, ion implantation, annealing and the like. As some of these parts, aluminum parts made of aluminum or an aluminum alloy are used. Among them, the metal used in the chamber is used in an etching device for processing a wafer, a thin film, etc. in a plasma environment and a film forming device for forming a thin film (hereinafter, a device for processing in a plasma environment is referred to as a plasma device). Most of the parts made are aluminum parts. As an example of aluminum parts, there is a plate provided with a large number of through holes in order to uniformly supply a raw material gas, a corrosive gas, etc. on a base material. Further, as another example, there are a heater, a shielding plate, and the like.

The above-mentioned aluminum parts generally have an oxide film on the surface thereof in order to protect them from plasma irradiation or the like, to impart electrical insulation, or to improve corrosion resistance. As a method of forming an oxide film on the surface of an aluminum part, for example, sulfuric acid anodic oxidation treatment using a sulfuric acid bath, organic acid anodic oxidation treatment typified by oxalic acid anodic oxidation, and a mixed solution of sulfuric acid and an organic acid are used. There is a mixed acid anodization treatment to be used. By these methods, an oxide film is formed on the surface of the aluminum part.

By the way, when various treatments are continuously or intermittently performed using a plasma device, the oxide film on the surface of aluminum parts may gradually deteriorate. Deterioration modes include corrosion of the surface of the oxide film due to ions, electrons, radicals, etc. contained in the plasma, alteration of the surface of the oxide film due to reduction or fluoride of the surface of the oxide film, and various treatments. Accumulation of reaction by-products generated on the surface of the oxide film can be mentioned. Deterioration of the oxide film is not limited to the plasma device, but may occur in semiconductor manufacturing devices and flat panel display manufacturing devices other than the plasma device.

Such deterioration of the oxide film hinders processing in various manufacturing equipment. For example, aluminum oxide peeled off from the oxide film due to corrosion or alteration may fall off, the oxide film transformed into fluoride may fall off from the base aluminum, or reaction by-products deposited on the surface may fall off. This causes particles to be generated. Therefore, in order to prevent such obstacles, aluminum parts used for various manufacturing equipment are periodically removed from the manufacturing equipment, and after the oxide film is completely removed, a new oxide film is applied. By forming, it is necessary to regenerate aluminum parts.

As a method for removing the oxide film, there are a method of removing the oxide film by immersing an aluminum part in an etching solution and a method of removing the oxide film by mechanical means such as grinding and polishing. Regarding the latter, Patent Document 1 describes that the oxide film of the aluminum part is removed, and further, the aluminum part from which the oxide film has been removed is subjected to a polishing treatment.

However, in the method of immersing the aluminum part in the etching solution, the aluminum part may be excessively etched for the reason described below. That is, in many cases, the deterioration of the oxide film is such that the entire oxide film of the aluminum part is unevenly deteriorated. Therefore, a portion where the deterioration state is relatively mild and a portion where the deterioration state is relatively severe may coexist. Here, if the etching conditions are adjusted so as to remove the severely deteriorated portion of the oxide film, the etching condition becomes an excessive condition for the portion where the deterioration is slight, and excessive etching is performed up to the base of the oxide film. It may be done.

The above problem becomes particularly remarkable when the oxide film is removed by using an etching solution on a plate provided with a large number of through holes. When the plate is etched under the condition that the severely deteriorated oxide film is completely removed, the oxide film is etched and the inner peripheral surface of the through hole is excessively etched in a place where the deterioration is light, for example, inside the through hole. In some cases, the inner diameter of the through hole may increase. When the oxide film of the plate is repeatedly regenerated, the variation in the inner diameter among the plurality of through holes was initially small, but the variation in the inner diameter among the through holes gradually increases. For example, when a thin film is formed using a plate having a changed shape of through holes in this way, the accumulated amount of the thin film raw material may be distributed and the thickness of the thin film may become non-uniform, which adversely affects the quality of the thin film. May affect.

Further, as described in Patent Document 1, when the oxide film is removed by mechanical means such as grinding and polishing, the aluminum underlying the oxide film is excessively ground, and the shape and dimensions of the aluminum part become large. It may change and cause processing problems in the manufacturing equipment. In order to prevent changes in shape and dimensions, it is conceivable to remove only the upper layer portion of the oxide film in the film thickness direction. However, even if the normal anodic oxidation treatment is performed with a part of the oxide film left without exposing the base, a new oxide film does not grow, so that it is difficult to regenerate the oxide film.

Furthermore, the aluminum parts may be accidentally damaged, causing peeled parts, scratches or abrasion marks on the oxide film. In this case, there was a request to partially regenerate the oxide film.

Japanese Unexamined Patent Publication No. 2004-21128

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for regenerating an oxide film of an aluminum part, which can regenerate an oxide film of an aluminum part.

In order to solve the above problems, the present invention adopts the following configuration.
[1] It has a component body made of aluminum or an aluminum alloy and an oxide film formed on the surface of the component body, and has at least one of a peeled portion, a flaw or a wear mark on the surface of the oxide film. A method for regenerating the oxide film of an aluminum part.
A method for regenerating an oxide film of an aluminum part, which comprises a regeneration step of repairing the oxide film by immersing the aluminum part in an electrolytic solution and performing a micro-arc oxidation treatment.
[2] A method for regenerating the oxide film of an aluminum component having a component body made of aluminum or an aluminum alloy and an oxide film formed on the surface of the component body.
A removal step of removing a part or all of the upper layer portion of the oxide film of the aluminum part, or removing a part of the oxide film.
A regeneration step of increasing the thickness of the oxide film at the removed portion by immersing the aluminum part that has undergone the removal step in an electrolytic solution and performing a micro-arc oxidation treatment.
A method for regenerating an oxide film of an aluminum part, which comprises.
[3] The method for regenerating an oxide film of an aluminum part according to [2], wherein the removing step uses a mechanical polishing treatment, a blasting treatment, or a high-pressure water injection treatment in order to remove the oxide film. ..
[4] The oxidation of the aluminum component according to [2] or [3], wherein the removing step removes an upper layer portion of the oxide film having foreign matter adhered to the surface or the oxide film having a deteriorated surface. How to regenerate the film.
[5] The aluminum component according to [2] or [3], wherein the removing step removes the oxide film on the portion where foreign matter adheres to the surface or the oxide film on the portion where the surface has deteriorated. How to regenerate the oxide film.
[6] The item according to any one of [1] to [5], wherein the aluminum part is installed and used in a chamber of a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus. How to regenerate the oxide film of aluminum parts.
[7] The aluminum component is installed in a chamber of a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus in which the component body is provided with a plurality of through holes along the plate thickness direction of the component body. It is a plate used
Item 1 of any one of [2] to [6], wherein the removing step is performed on the oxide film formed on a part or all of the surface of the component body provided with the through hole. A method for regenerating an oxide film of an aluminum part described in.
[8] The method for regenerating an oxide film of an aluminum part according to [7], wherein the removing step is not performed on the oxide film formed on the inner surface of the through hole.
[9] The aluminum according to any one of [1] to [8], wherein the regeneration step is a step of increasing the film thickness of the oxide film to be thicker than the film thickness before the regeneration step. How to regenerate the oxide film of manufactured parts.

According to the method for regenerating an oxide film of an aluminum part of the present invention, an aluminum part having at least one of a peeled portion, a flaw or a wear mark on the surface of the oxide film is subjected to a microarc oxidation treatment to be oxidized. Since the film is repaired, aluminum parts can be regenerated as if they were new.

Further, according to the method for regenerating the oxide film of an aluminum part of the present invention, a part or all of the upper layer portion of the oxide film of the aluminum part is removed, or a part of the oxide film is removed. Next, the aluminum parts are subjected to microarc oxidation treatment to increase the thickness of the oxide film at the removed portion, so that the deteriorated oxide film can be replaced with a new oxide film, and the aluminum parts can be regenerated. it can. In the present invention, the entire thickness direction of the oxide film is not removed, only the upper layer portion of the oxide film is removed, and the rest other than the upper layer portion is left, so that a part of the main body of the aluminum part is left. There is no risk of accidentally removing excess. Further, by performing the micro-arc oxidation treatment, a new oxide film can be formed on the oxide film whose film thickness is reduced and the insulation resistance is reduced by removing the upper layer portion, and the upper layer portion is removed. The oxide film can be easily restored to the original thickness before the upper layer is removed.
Further, in the present invention, the entire oxide film may not be removed but a part thereof may be left. In this case, the risk of accidentally damaging the entire surface of the main body of the aluminum component is reduced. Further, by performing the micro-arc oxidation treatment with a part of the oxide film left, an oxide film having the same thickness as the remaining oxide film can be formed.
As described above, according to the present invention, the oxide film of aluminum parts can be regenerated.

Further, according to the method for regenerating an oxide film of an aluminum part of the present invention, a mechanical polishing treatment, a blast treatment or a high-pressure water injection treatment is used to remove the oxide film in the removing step, so that the deteriorated oxide film is partially removed. Since it can be removed as a target and a sound oxide film can be left, the oxide film can be rapidly regenerated in the regeneration process. Further, as compared with the conventional removal treatment with an etching solution, there is no possibility of causing a problem such as excessive etching of a sound oxide film forming portion.

Further, according to the method for regenerating the oxide film of an aluminum part of the present invention, in the removing step, the oxide film having foreign matter adhered to the surface or the upper layer of the oxide film having a deteriorated surface is removed, so that only the deteriorated oxide film is removed. Can be replaced with a new oxide film, and aluminum parts can be quickly regenerated.

Further, according to the method for regenerating the oxide film of an aluminum part of the present invention, in the removing step, the oxide film on the portion where foreign matter adheres to the surface or the oxide film on the portion where the surface has deteriorated is removed, so that the deteriorated oxide film is removed. Only can be replaced with a new oxide film, and aluminum parts can be quickly regenerated.

Further, according to the method for regenerating the oxide film of an aluminum part of the present invention, it is assumed that the target aluminum part is installed and used in the chamber of the semiconductor manufacturing apparatus or the flat panel display manufacturing apparatus. It can regenerate aluminum parts that are used in the chamber and have a partially deteriorated oxide film.

Furthermore, according to the method for regenerating the oxide film of an aluminum part of the present invention, the aluminum part is a plate having a plurality of through holes, and is formed on a part or all of the surface provided with the through holes. Since the regeneration method of the present invention is carried out on the oxide film, the oxide film of the severely deteriorated portion of this plate can be selectively regenerated.

Furthermore, according to the method for regenerating the oxide film of an aluminum part of the present invention, the oxide film formed on the inner surface of the through holes of the plate having a plurality of through holes is not removed in the removing step, and therefore the regeneration of the present invention is performed. Even if the method is repeated, the inner diameter of the through hole is maintained in the state of a new plate, so that defects caused by changes in the through hole of the plate in the chamber, for example, non-uniformity of the thickness of the formed thin film, can be caused. I won't invite you.

Further, according to the method for regenerating the oxide film of an aluminum part of the present invention, the aluminum part can be covered with a new oxide film by making the film thickness of the oxide film thicker than that before the regeneration process. It can improve the quality of aluminum parts.

As described above, according to the present invention, it is possible to provide a method for regenerating an oxide film of an aluminum component, which can regenerate a deteriorated oxide film.

The cross-sectional schematic diagram explaining the removal process in the method of regenerating the oxide film of the aluminum part of embodiment. The cross-sectional schematic diagram explaining the removal process in the method of regenerating the oxide film of the aluminum part of embodiment. The cross-sectional schematic diagram explaining the removal process in the method of regenerating the oxide film of the aluminum part of embodiment. The cross-sectional schematic diagram explaining the removal process in the method of regenerating the oxide film of the aluminum part of embodiment. The cross-sectional schematic diagram explaining the regeneration process in the method of regenerating the oxide film of the aluminum part of embodiment. The cross-sectional schematic diagram explaining the regeneration process in the method of regenerating the oxide film of the aluminum part of embodiment. FIG. 5 is a schematic cross-sectional view illustrating another example of a method for regenerating an oxide film of an aluminum component according to an embodiment. FIG. 5 is a schematic cross-sectional view illustrating another example of a method for regenerating an oxide film of an aluminum component according to an embodiment. FIG. 5 is a schematic cross-sectional view illustrating still another example of the method for regenerating the oxide film of the aluminum component of the embodiment. FIG. 5 is a schematic cross-sectional view illustrating still another example of the method for regenerating the oxide film of the aluminum component of the embodiment.

Hereinafter, a method for regenerating the oxide film of an aluminum component according to the embodiment of the present invention will be described.
The method for regenerating the aluminum part of the present embodiment includes a removal step of removing a part or all of the upper layer of the oxide film of the aluminum part, or removing a part of the oxide film, and micro-arc oxidation. It is provided with a regeneration step of increasing the thickness of the oxide film at the removed portion by the treatment.
Hereinafter, each step will be described.

The aluminum component to be processed in the present embodiment includes a component body made of aluminum or an aluminum alloy, and an oxide film formed on the surface of the component body. The aluminum parts of the present embodiment are parts provided in the chambers of various manufacturing devices.

The various manufacturing devices are, for example, semiconductor manufacturing devices or flat panel display manufacturing devices, and more specifically, sputtering film deposition devices, CVD film deposition devices (CVD: Chemical Vaper Deposition), vacuum deposition devices, and ashing devices. , Etching device, ion implantation device, annealing device and the like.

Further, the chamber of the above-mentioned manufacturing apparatus is a processing chamber capable of controlling the internal atmosphere in order to accommodate the base material to be processed and to perform film formation, etching, ion implantation, annealing, etc. on the base material. .. These chambers are provided with various components for smooth film formation, etching, ion implantation, annealing and the like.

The aluminum part of the present embodiment is a part used in the above-mentioned chamber, and can be removed from the chamber during maintenance of the manufacturing apparatus.

Specific examples of the aluminum component include a plate having a plurality of through holes, a heater, a shielding member, and the like. These parts are mainly used in an etching apparatus for processing a base material, a thin film, or the like in a plasma environment, and a film forming apparatus for forming a thin film (hereinafter, an apparatus for processing in a plasma environment is referred to as a plasma apparatus).

A plate having a plurality of through holes is a component in which a plurality of through holes are provided in the component body along the plate thickness direction of the component body. The inner diameter of the through hole is about 0.1 to 2 mm, and the number of through holes is several thousand to tens of thousands depending on the size of the component body.

The component body that constitutes an aluminum component is made of aluminum or an aluminum alloy. The aluminum or aluminum alloy is not particularly limited, and examples thereof include pure aluminum of JIS alloy number 1000 series and aluminum alloys of 2000 series, 3000 series, 4000 series, 5000 series, 6000 series or 7000 series. Further, as the aluminum alloy, Al—Si based alloy, Al—Mg based alloy, Al—Cu—Si based alloy, Al—Cu-Mg—Si based alloy, Al—Mg—Si based alloy and the like can also be used.

There are no particular restrictions on the shape of the component body. Like the plate described above, a plate having a large number of through holes may be provided.

The oxide film constituting the aluminum component is preferably an oxide film containing aluminum oxide as a main component. The oxide film is not a natural oxide film, but an oxide film intentionally formed on the component body.

The oxide film constituting the aluminum component may be an oxide film formed by the micro-arc oxidation treatment described later. Further, the oxide film may be an anodic oxide film formed by various anodic oxidation methods. Examples of the anodic oxidation method include sulfuric acid anodic acid treatment using a sulfuric acid bath, organic acid anodic acid treatment typified by oxalic acid anodic acid, and mixed acid anodic acid treatment using a mixed solution of sulfuric acid and an organic acid. Further, the oxide film constituting the aluminum component may be an oxide film formed by alumite treatment.

The oxide film constituting the aluminum component is preferably formed on the entire surface of the component body. For example, it is preferable that an oxide film is also formed on the inner peripheral surface of the through hole of the plate.

The thickness of the oxide film constituting the aluminum component may be, for example, in the range of 5 to 20 μm. The thickness of the oxide film may be measured by exposing a cross section of an aluminum part at an arbitrary portion and measuring the thickness of the oxide film in the cross section using an optical microscope or a scanning electron microscope. When the thickness is non-uniform, for example, the thickness of the oxide film may be measured at 10 points at 10 mm intervals in the cross section and used as the average value of the measured values at these 10 points.

Next, the removal step will be described.
It is assumed that the oxide film of the aluminum parts used in the removal process has deteriorated. Here, the deterioration of the oxide film includes, for example, a state in which contaminants are attached to the surface of the oxide film, or a state in which the surface of the oxide film is altered.

The state in which the contaminants are attached to the surface includes, for example, a state in which reaction by-products generated by various treatments of the above-mentioned manufacturing apparatus are deposited on the surface of the oxide film.

The altered state of the surface of the oxide film is, for example, a state in which the surface of the oxide film is corroded by ions, electrons, radicals, etc. contained in plasma, or the surface of the oxide film is reduced or fluorinated to cause oxidation. The state where the surface of the film is altered can be mentioned.

The presence or absence of deterioration of the oxide film can be determined by visually observing the appearance of the oxide film. When the oxide film is discolored or the surface of the oxide film is roughened, it can be determined that the oxide film has deteriorated.

For example, when an aluminum part is installed and used in the chamber of the above-mentioned manufacturing apparatus and a discoloration is observed in a part or all of the oxide film, the oxide film is considered to be deteriorated. The component can be a reproduction target of the reproduction method of this embodiment.

In addition, the aluminum component may be accidentally damaged, causing the oxide film to form at least one or more of peeled parts, scratches, or abrasion marks. Such defective parts of the oxide film can be confirmed with the naked eye. Therefore, as a result of observing the appearance of the oxide film, it can be determined that the oxide film has deteriorated even when a defective portion is found. Such aluminum parts can also be the target of the recycling method of the present embodiment. Further, the aluminum parts on which the peeled portion, the flaw and the worn portion are formed may be those before use or after use in various manufacturing devices.

The aluminum parts targeted in this embodiment are not limited to those described above, and are applied to all aluminum parts whose surface has deteriorated to the extent that they are used in the above-mentioned various manufacturing devices and interfere with processing. Can be done.

The removing step is a step of removing a part or all of the upper layer portion of the oxide film of the aluminum part, or removing a part of the oxide film. When the deterioration of the oxide film is limited to a part of the oxide film, the upper layer of the deteriorated oxide film may be removed, and the upper layer of the oxide film in a healthy portion may not be removed. Further, when the deterioration of the oxide film extends to the entire oxide film, the upper layer portion of all the oxide film may be targeted for removal. Further, when the deterioration of the oxide film is limited to a part of the oxide film, the deteriorated oxide film may be removed by leaving the non-deteriorated oxide film (in this case, not only the upper layer part but the entire thickness direction is removed). ..

When removing the upper layer of the oxide film, the removal range includes deteriorated parts such as discolored parts, roughened parts, peeled parts, and scratched parts of the oxide film, and oxidation of the region including the periphery of these deteriorated parts. It may be the upper layer of the film. Further, when the deteriorated portion is widely distributed in the oxide film, the entire upper layer portion of the oxide film may be removed.

The reason why the removal range is the upper layer of the oxide film is as follows. The deterioration of the oxide film often stays on or near the surface of the oxide film, and the deterioration rarely reaches the interface side between the oxide film and the component body. Therefore, the parts other than the upper layer are in a healthy state without deterioration. If such a healthy part is included in the removal range, the removal process becomes complicated and the productivity decreases. Therefore, the removal range of the oxide film is the upper layer of the deteriorated oxide film. In addition, by setting the removal range of the oxide film to the upper layer of the deteriorated oxide film, the component body is covered with the remaining oxide film without exposing the underlying component body during the removal step to the regeneration process. Can be protected. In addition, there is no risk of accidentally damaging the component body when removing the oxide film.

Hereinafter, a case where the upper layer portion of the oxide film is removed will be described.
FIG. 1A shows a schematic partial cross-sectional view of the aluminum part before the removal step. As shown in FIG. 1A, the aluminum component 1 before the removal step includes a component body 2 and an oxide film 3 formed on the surface of the component body 2. Further, there is a deteriorated portion 3a in a part of the oxide film 3. In the removing step of this example, the upper layer 3b of the oxide film in the region including the periphery of the deteriorated portion 3a is removed. In FIG. 1A, the deteriorated portion is indicated by “x”. The same applies to FIGS. 2A and 2B.

FIG. 1B shows a schematic partial cross-sectional view of the aluminum part 1 after the removal step. As shown in FIG. 1B, the thickness of the oxide film 3 is partially reduced by going through the removal step.

Here, when removing the upper layer portion 3b of the oxide film 3, as shown in FIG. 1B, when the thickness of the oxide film 3 before removal is T, the thickness T of the oxide film 3 after removing the upper layer portion 3b. It is preferable to remove the upper layer portion 3b so that ′ is in the range of 0.2T to 0.5T. It is preferable that the thickness T'of the oxide film 3 after removal is 0.2 T or more because the time required to increase the thickness of the oxide film in the regeneration step can be shortened. Further, it is preferable that the thickness T'of the oxide film 3 after removal is 0.5 T or less because the deteriorated portion can be completely removed.

The surface of the oxide film remaining after the upper layer portion is removed in the removing step does not have to be a flat surface and may have waviness. That is, the residual film thickness may vary. The range of variation in the residual film thickness may be, for example, in the range of 0.2T to 0.5T, where T is the thickness of the oxide film 3 before removal. In the micro-arc oxidation treatment carried out in the regeneration step of the present embodiment, the film thickness can be adjusted according to the set voltage value, and the film thickness after regeneration can be made uniform. Therefore, even if the film thickness of the oxide film remaining in the removal step varies, it can be regenerated into an oxide film having a uniform film thickness by the regeneration step.

The examples shown in FIGS. 1A and 1B are examples in which a part of the upper layer portion of the oxide film is removed. When the deteriorated portion 3a is distributed over a wide range of the oxide film 3, the upper layer portion 3b of the entire oxide film 3 may be removed.

In the removing step, mechanical polishing treatment, blast treatment, or high-pressure water injection treatment can be adopted as a means for removing the upper layer portion 3b. The mechanical polishing treatment is, for example, a polishing treatment in which a polishing liquid containing an abrasive is applied to the surface of the oxide film to polish it, a polishing treatment in which the surface of the oxide film is polished with a brush or a cloth containing the abrasive, or a hard polishing material. An example is a polishing process for polishing the surface of an oxide film. Examples of the blasting treatment include a blasting treatment in which dry ice powder is sprayed onto the surface of the oxide film. Examples of the high-pressure water injection process include a process of injecting high-pressure water onto the surface of the oxide film to remove deteriorated parts. In the removing step of the present embodiment, it is desirable not to perform the etching process using the etching solution. This is because there is a risk of excessive etching of the component body.

When the aluminum part is a plate having a plurality of through holes, the removal step may be performed as follows. As shown in the enlarged cross-sectional schematic view of FIG. 2A, the plate 11 before the removal step includes the component body 12, a plurality of through holes 12a provided along the thickness direction of the component body 12, the surface of the component body 12, and the surface of the component body 12. An oxide film 13 formed on the inner peripheral surface of the through hole 12a is provided. The oxide film 13 includes an oxide film 13a formed on the surface of the component body 12 provided with the through hole 12a and an oxide film 13b provided on the inner peripheral surface of the through hole 12a. The oxide films 13a and 13b have deteriorated portions 13c.

FIG. 2B shows a schematic enlarged cross-sectional view of the plate 11 after the removal step. In the removing step for the plate 11, the upper layer portion of the oxide film 13a on the surface of the component body 12 provided with the through hole 12a is removed, and the oxide film 13b formed on the inner surface of the through hole 12a is not removed. As a result, as shown in FIG. 2B, the film thickness of the oxide film 13a of the plate 11 after the removal step is reduced as compared with that before the removal step, and the film thickness of the oxide film 13b is not reduced. The deteriorated portion 13c remains in the oxide film 13b inside the through hole 12a, but even if this is left, no problem occurs during processing in the manufacturing apparatus, so it is not necessary to remove it.

Before performing the removal step, the aluminum parts may be cleaned with water or an organic solvent in order to remove the soluble deposits adhering to the aluminum parts.

Next, the regeneration process will be described.
In the regeneration step, the aluminum parts that have undergone the removal step are immersed in an electrolytic solution and subjected to microarc oxidation treatment to increase the thickness of the oxide film from which the upper layer portion has been removed. The micro-arc oxidation treatment is an anodic oxidation treatment accompanied by spark discharge. In the removal step, the oxide film whose upper layer is removed and the film thickness is thinned is dielectrically broken down to grow a new oxide film, and the oxide film is formed. The oxide film continues to grow until the thickness increases and the insulation resistance increases.

By performing the micro-arc oxidation treatment, a new oxide film can be formed on the oxide film having a reduced film thickness. As a result, the oxide film from which the upper layer portion has been removed can be restored to the original thickness before the upper layer portion is removed.
Hereinafter, preferable conditions for the micro-arc oxidation treatment will be described. In the present embodiment, the oxide film is regenerated by adopting either of the following conditions 1 or 2, but the present embodiment is not limited to these conditions 1 and 2.

(Condition 1)
Under condition 1, the aluminum part that has undergone the removal step is immersed in an electrolytic solution, micro-arc oxidation treatment is performed at a predetermined current density, and after reaching a predetermined voltage, the voltage is maintained constant. After the voltage is made constant, the current density gradually decreases, but the processing may be terminated when the current density becomes 1/100 to 1/10 of the current density at the start of the processing with the constant voltage. ..

The current density during the micro-arc oxidation treatment is preferably 1 to 6 A / dm ² , and more preferably 1 to 4 A / dm ² . If it is 1 A / dm ² or more, the discharge is sufficient, and if it is 6 A / dm ² or less, the film quality becomes uniform at the boundary between the oxide film not removed in the removal step and the newly formed oxide film.

The temperature of the electrolytic solution is preferably −10 to 65 ° C. This is because a stable oxide film can be formed by using a small-scale cooling facility such as a cooling chiller instead of a large cooling facility.

Examples of the electrolytic solution include disodium hydrogen phosphate, sodium tripolyphosphate, sodium dihydrogen phosphate, ultrapolysodium phosphate, sodium silicate, potassium hydroxide, sodium diphosphate, trisodium phosphate, and aluminate. One of sodium, sodium metasilicate, sodium hydroxide and the like, or a mixture thereof, dissolved in water can be used.

Further, when the area where the oxide film is to be regenerated becomes a large area such as a plate having through holes, the micro arc oxidation treatment may be performed in a plurality of times. That is, as the first treatment, a part of the aluminum part is immersed in the electrolytic solution and micro-arc oxidation treatment is performed to form an oxide film at the immersed portion. Then, as the second treatment, an oxide film is formed by immersing another part (remaining part) different from the part of the oxide film formed in the first time in the electrolytic solution. In this way, the oxide film may be formed a plurality of times at a portion where the oxide film needs to be regenerated. When the second oxide film is formed, the first oxide film becomes an insulating film, so that in the second treatment, the oxide film is concentratedly formed only in the portion where the first oxide film is not formed. become.

(Condition 2)
In condition 2, the aluminum part that has undergone the removal step is immersed in an electrolytic solution to perform microarc oxidation treatment. At that time, the first step and the first step of performing the microarc oxidation treatment up to a first voltage of 200 V or more at a constant current density. Without performing constant voltage processing with the first voltage, the voltage is lowered linearly or stepwise from the first voltage to the second voltage, which is a voltage lower than the first voltage, in a predetermined time. The second step of performing the micro-arc oxidation treatment and the third step of performing the constant voltage treatment at the second voltage are performed.

In the first step, the processing time by the first voltage is continued until the first voltage becomes 200 V or more.
The current density at the start of processing the first voltage is preferably in the range of 1 A / dm ^{2 to} 20 A / dm ² . If it is 1 A / dm ² or more, the voltage rises sufficiently and can be discharged. Further, by setting the current density to 20 A / dm ² or less, it is possible to prevent the formed oxide film from being destroyed by electric discharge, to make the film structure dense, and to improve the corrosion resistance.

In the second step, after the first voltage is reached in the first step, the second voltage is a voltage lower than the first voltage from the first voltage without performing constant voltage processing by the first voltage. Until, the voltage is lowered linearly or stepwise at a predetermined time to perform the micro arc oxidation treatment. As a result, it is possible to avoid dielectric breakdown of the oxide film in the constant voltage treatment with the first voltage, and further, it is possible to suppress power consumption.

Between the second step and the third step, an intermediate step of raising the voltage from the second voltage to the first voltage is performed, the second step and the intermediate step are made into one set of steps, and this one set of steps is defined as one set of steps. It is preferable to repeat the process a plurality of times after the first step. Thereby, the film quality of the oxide film can be improved.

Further, "stepwise" means that at least one constant voltage process is performed at a voltage between the first voltage and the second voltage, and when the voltage is lowered stepwise, at least 1 is performed. The voltage at one stage is preferably held for 30 seconds or longer. This is because it takes time to form an oxide film on a portion where an oxide film is difficult to form. The upper limit of this time is 10 hours at the maximum. This is because if it exceeds 10 hours, the oxide film is corroded by electrolysis or the electrolytic solution.

Further, the waveform of the applied voltage and current may be any of alternating current, direct current, and superposition of alternating current and direct current, and in the case of alternating current, the current or voltage may be a sine wave or not a sine wave.
As described above, by processing the voltage at a constant voltage, the oxide film can be sequentially formed in the place where the current easily flows, that is, the place where the oxide film is not formed.

In the third step, the constant voltage processing is performed at the voltage at the end of the second step, that is, the second voltage for a predetermined time. The processing time is preferably 5 minutes to 10 hours. The oxide film does not grow sufficiently in less than 5 minutes. If it exceeds 10 hours, the oxide film may be corroded by electrolysis or the electrolytic solution.

Also in the second condition, when the area where the oxide film is to be regenerated becomes a large area such as a plate having through holes, the micro-arc oxidation treatment may be performed in a plurality of times.

FIG. 3A shows a schematic cross-sectional view of the aluminum part 1 before the recycling process, and FIG. 3B shows a schematic cross-sectional view of the aluminum part 1 after the recycling process. By performing the micro-arc oxidation treatment, the film thickness of the portion 3A of the oxide film 3 in which the upper layer portion was not removed hardly changed even after the regeneration step, but the upper layer portion was removed and the film thickness decreased. A new oxide film grows on the portion 3B to increase the film thickness, preferably to the same film thickness as the portion 3A. In order to adjust the film thickness of the newly formed oxide film 3, it is preferable to adjust the conditions of the micro-arc oxidation treatment so that the oxide film grows to the original film thickness of the oxide film. Specifically, the voltage may be set as appropriate.

Here, in the example shown in FIG. 3B, the component body 2 does not show a large change before and after the regenerating process, but the component body 2 may change slightly before and after the regenerating process. That is, since the microarc oxidation treatment is a film forming process using the underlying aluminum or an aluminum alloy as a raw material for the oxide film, the film thickness decreases when a new oxide film is grown on the portion 3B where the film thickness has decreased. In some cases, the surface layer of the component body 2 directly below the formed portion 3B may be replaced with an oxide film from aluminum or an aluminum alloy.

In addition, the example shown in FIG. 3A and FIG. 3B is an example in which the regeneration step was carried out on the aluminum part 1 from which the upper layer portion of a part of the oxide film 3 was removed. When the regeneration step is carried out on the aluminum part from which the upper layer portion of all the oxide film 3 has been removed, it is preferable to grow the aluminum part until the total thickness of the oxide film becomes the original thickness. Also in this case, it is preferable to adjust the conditions of the micro-arc oxidation treatment. Specifically, the voltage may be set as appropriate. Further, in this case as well, the upper layer portion may be removed and the surface layer of the component body 2 immediately below the portion may be replaced with an oxide film from aluminum or an aluminum alloy.

Even if the surface layer of the component body 2 is replaced with an oxide film from aluminum or an aluminum alloy, the amount of replacement is very small, which causes troubles in various processes in semiconductor manufacturing equipment and flat panel display manufacturing equipment. It's not.

The oxide film left in the removal process and the oxide film newly formed in the regeneration process have almost the same film quality and have almost the same film thickness before and after the regeneration, so they are necessary as aluminum parts. , Durability against plasma irradiation, electrical insulation, and corrosion resistance.

In the plate regenerated by the regeneration method of the present embodiment, a plurality of through holes are provided in the component body along the plate thickness direction of the component body, and the entire surface of the component body including the inner peripheral surface of the through holes is oxidized. A film is formed, and the oxide film on the inner peripheral surface of the through hole is in a deteriorated state, and the other oxide films are not deteriorated. Therefore, by checking the state of the oxide film on the inner peripheral surface of the through hole, it can be determined whether or not the regeneration method of the present embodiment has been applied to the plate.

As described above, according to the present embodiment, the deteriorated oxide film can be regenerated without grinding or polishing the component body which is the base of the oxide film.

In the embodiment described above, a method of regenerating the oxide film after removing the upper layer portion of the oxide film has been described, but in the present invention, as shown in FIG. 4A, the oxide film of the deteriorated portion of the oxide film 3 After removing all 13B in the thickness direction, the oxide film 3 may be regenerated by microarc oxidation treatment as shown in FIG. 4B.

In this case, the removal range of the oxide film includes deteriorated parts such as discolored parts, roughened parts, peeled parts, and scratched parts of the oxide film, as in the cases shown in FIGS. 1A and 1B. It may be an oxide film in a region including the periphery of the deteriorated portion.

When removing the entire thickness direction of the oxide film of the deteriorated portion 13B, mechanical polishing treatment, blast treatment or high-pressure water injection treatment can be adopted, but the treatment conditions are such that the component body 2 which is the base of the oxide film 3 is not damaged. Is desirable.

After the removal step, the oxide film can be regenerated by performing a regeneration step by micro-arc oxidation treatment in the same manner as in the above embodiment.

Further, in the above-described embodiment, aluminum parts used in various manufacturing devices and having an oxide film on which foreign matter adheres to the surface or an oxide film on which the surface is altered are targeted for the regeneration method. In the example described below, an aluminum part having an oxide film having a defective portion on the surface is targeted. Examples of such aluminum parts include those in which defective parts such as peeled parts, scratches such as scratches and dents, or wear marks are generated on the oxide film during handling of aluminum parts. The oxide film other than the defective part is in a healthy state. FIG. 5A shows an oxide film 3 having a dented defect 24B.

For such aluminum parts, the removal step and the regeneration step may be performed as described above, but the removal step of the oxide film may be omitted and the regeneration step may be performed. The oxide film 3 in which the dented flaw 24B is formed has a locally reduced thickness at the portion of the dented flaw 24B. By performing the micro-arc oxidation treatment on such an oxide film, a new oxide film can be formed at the portion of the dented defect 24B, whereby the dented defect 24B is eliminated and the aluminum part is regenerated. it can.

Further, in the above embodiment, when adjusting the film thickness of the newly formed oxide film in the regeneration step, the micro-arc oxidation treatment is performed so that the oxide film grows to the original film thickness of the oxide film. Although it has been explained that it is preferable to adjust the conditions, the present invention is not limited to this, and the conditions of the microarc oxidation treatment are adjusted so that the oxide film grows to a film thickness exceeding the film thickness of the original oxide film. May be good. As a result, the entire aluminum part can be covered with a new oxide film, and the quality of the aluminum part can be improved.

Hereinafter, the present invention will be described in more detail by way of examples. It should be noted that the examples described below show one aspect of the present invention, and the present invention is not limited to this embodiment.

A plate having a length of 1100 mm, a width of 900 mm, and a thickness of 20 mm was prepared. The plate was provided with a large number of through holes having an inner diameter of 0.69 mm. Further, the plate was made of an aluminum alloy component body in which an oxide film was formed with an average thickness of 15 μm. The oxide film was formed by a micro-arc oxidation treatment method. At this time, an oxide film was also formed on the inner peripheral surface of the through hole.

The above plate was mounted in the chamber of the plasma film forming apparatus which is a flat panel display manufacturing apparatus, and a film forming process was performed on a plurality of glass substrates while supplying a raw material gas. In addition, a cleaning process was performed in which fluorine gas was appropriately flowed into the chamber between the film forming processes. The film formation treatment and the cleaning treatment were carried out until the upper limit of use time of the plate, and after the upper limit of use time had elapsed, the plate was taken out from the chamber. Aluminum fluoride was formed on the surface of the oxide film of the plate by the reaction of aluminum oxide and fluorine gas.

As a removal step, the plate was mechanically polished with a polishing cloth to remove the upper layer of the oxide film. The removal range covered the entire oxide film formed on the surface of the plate, but did not remove the oxide film in the through holes. The residual film thickness of the oxide film was in the range of 3 to 6 μm and varied slightly. The residual film thickness of the oxide film was in the range of 0.2T to 0.5T when the original thickness of the oxide film was T (15 μm).

Next, as a regeneration step, the plate after the removal step was immersed in an electrolytic solution to perform microarc oxidation treatment. As the electrolytic solution, an alkaline electrolytic solution in which potassium hydroxide, sodium metasilicate and trisodium phosphate were each dissolved in pure water so as to be 3 g / L was used. The above electrolytic solution was placed in an electrolytic cell provided with a carbon counter electrode, and micro-arc oxidation treatment was performed with a constant DC current. After forming an oxide film at a current density of 6.0 A / dm ² until it reached 450 V, constant voltage treatment was performed at 450 V until the current density reached 0.28 A / dm ² . The temperature of the electrolytic solution was 65 ° C. or lower. In this way, the oxide film was regenerated.

The regenerated plate is mounted in the chamber of the plasma film forming apparatus in the same manner as above, the film forming process and the cleaning process are performed in the same manner as above, and after the upper limit of use has elapsed, the plate is taken out from the chamber and the same as above. The removal step and the regeneration step were carried out. This series of operations was repeated a total of three times. The plate in which the oxidation film was repeatedly regenerated in this way was used as the plate of the example.

On the other hand, as a removal step, an aqueous sodium hydroxide solution is used as an etching solution, and the entire oxide film is removed by immersing the used plate in the etching solution. A shower plate was prepared.

For the plates of Examples and Comparative Examples, changes in the inner diameter of the through holes in the region where the amount of aluminum fluoride adhered was small were investigated. Ten through holes were arbitrarily selected, the inner diameter was measured, and the average value was calculated. The inner diameter of the through hole was measured after each of the three regeneration steps. The results are shown in Table 1 below.

As shown in Table 1, the inner diameter of the through hole of the plate of the example does not change even when the regeneration is repeated, whereas the inner diameter of the plate of the comparative example increases each time the regeneration is repeated. It can be seen that the shape of the through hole has changed.

Further, in the plate of the example, the upper layer portion of the oxide film was removed in the removing step to leave the remaining portion of the oxide film and the component body was not exposed, but the micro-arc oxidation treatment was performed in the regeneration step. A new oxide film could be formed. In the examples, no clear boundary such as an interface was confirmed between the oxide film remaining in the removal step and the newly formed oxide film, and the remaining oxide film and the new oxide film were integrated. ..

Further, in the plate of the example, the amount of the oxide film removed varied in the removing step, but the film thickness of the oxide film after regeneration was approximately 15 μm, and the film thickness did not vary.

Further, since the oxide film of the example was left in the removing step, the plate was protected by the oxide film left on the component body, and the component body was not scratched or the like.

On the other hand, in the plate of the comparative example, since all the oxide film was removed in the removing step, the working time of the regeneration step was longer than that in the case of the example.

1 ... Aluminum parts, 2, 12 ... Parts body, 3 ... Oxide film, 3b ... Upper layer of oxide film, 11 ... Plate, 12a ... Through holes, 13a ... Oxide film on the surface provided with through holes, 13b ... An oxide film formed on the inner surface of the through hole.

Claims (9)

An aluminum component having a component body made of aluminum or an aluminum alloy and an oxide film formed on the surface of the component body, and having at least one of a peeled portion, a flaw or a wear mark on the surface of the oxide film. The method for regenerating the oxide film of
A method for regenerating an oxide film of an aluminum part, which comprises a regeneration step of repairing the oxide film by immersing the aluminum part in an electrolytic solution and performing a micro-arc oxidation treatment. A method for regenerating the oxide film of an aluminum part having a component body made of aluminum or an aluminum alloy and an oxide film formed on the surface of the component body.
A removal step of removing a part or all of the upper layer portion of the oxide film of the aluminum part, or removing a part of the oxide film.
A regeneration step of increasing the thickness of the oxide film at the removed portion by immersing the aluminum part that has undergone the removal step in an electrolytic solution and performing a micro-arc oxidation treatment.
A method for regenerating an oxide film of an aluminum part, which comprises. The method for regenerating an oxide film of an aluminum part according to claim 2, wherein the removing step uses a mechanical polishing treatment, a blasting treatment, or a high-pressure water injection treatment in order to remove the oxide film. The regeneration of the oxide film of the aluminum component according to claim 2 or 3, wherein the removing step removes the upper layer portion of the oxide film having foreign matter adhered to the surface or the oxide film having a deteriorated surface. Method. The oxide film of an aluminum part according to claim 2 or 3, wherein the removing step removes the oxide film of the portion where foreign matter adheres to the surface or the oxide film of the portion whose surface has deteriorated. Playback method. The aluminum component according to any one of claims 1 to 5, wherein the aluminum component is installed and used in a chamber of a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus. How to regenerate the oxide film of a part. The aluminum component is installed and used in a chamber of a semiconductor manufacturing apparatus or a flat panel display manufacturing apparatus in which the component body is provided with a plurality of through holes along the plate thickness direction of the component body. It is a plate
Any one of claims 2 to 6, wherein the removing step is performed on the oxide film formed on a part or all of the surface of the component body provided with the through hole. A method for regenerating an oxide film of an aluminum part described in. The method for regenerating an oxide film of an aluminum part according to claim 7, wherein the removing step is not performed on the oxide film formed on the inner surface of the through hole. The aluminum component according to any one of claims 1 to 8, wherein the regeneration step is a step of increasing the film thickness of the oxide film to be thicker than the film thickness before the regeneration step. How to regenerate the oxide film.

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