JP2022181339A - Aluminum material and electrostatic discharge characteristic control film therefor - Google Patents

Abstract

To provide an aluminum material including a porous aluminum oxide layer and showing electrostatic discharge characteristics suitable when performing an ESD countermeasure.SOLUTION: An aluminum material includes: an aluminum base material; a porous aluminum oxide layer provided on the surface of the aluminum base material and having a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×108 Ω/sq or more and less than 1×1013 Ω/sq; and an electrostatic discharge characteristic control film provided on the porous aluminum oxide layer and controlling the electrostatic discharge characteristics of the surface. The electrostatic discharge characteristic control film includes a hard carbon film layer having a surface resistance value of 3×104 Ω/sq or more and 1×1012 Ω/sq or less.SELECTED DRAWING: Figure 1

Description

There is an application for the application of Article 30, Paragraph 2 of the Patent Law https://www. setcor. org/conferences/surfcoat-korea-2021/conference-program Abstract (Published: May 5, 2021, Updated: May 18, 2021)

TECHNICAL FIELD The present invention relates to an aluminum material, and more particularly to an aluminum material to which electrostatic discharge countermeasures have been applied.

2. Description of the Related Art Conventionally, various aluminum or aluminum alloy jigs, parts, and the like (hereinafter referred to as "aluminum products") have been used in the manufacturing process of semiconductor components or semiconductor products (hereinafter, semiconductor devices). For example, wafer cassettes used in cleaning processes (see, for example, Patent Document 1), pick-up nozzles for holding and fixing wafers and chips at predetermined positions in pattern forming processes, die bonding processes, etc., and transporting nozzles to predetermined positions. The transfer arms and the like used in this case are aluminum products used in the manufacturing process of semiconductor devices.

Also, semiconductor devices are manufactured in clean rooms. 2. Description of the Related Art In a circuit forming process, if exposure failure or the like of a circuit pattern due to dust occurs, the circuit pattern cannot be formed accurately. Therefore, it is necessary to suppress dust generation in the clean room. Since the various aluminum products described above are used in direct contact with semiconductor devices, there is a risk that the surfaces will be scraped during contact and sliding, and abrasion powder and the like will be generated. Therefore, the surfaces of aluminum products used in the manufacturing process of semiconductor devices are often treated to increase hardness.

However, when objects, especially insulators, contact or slide against each other, their surfaces are charged with static electricity. When a conductor comes into contact with the charged object, static electricity is discharged. If a surge voltage (or spike voltage) exceeding the withstand voltage is applied to a semiconductor device due to electrostatic discharge, dielectric breakdown may occur, and if a surge current exceeding the allowable current flows, problems such as thermal disconnection of fine wiring may occur. be. Therefore, various electrostatic discharge countermeasures (ESD countermeasures) are taken in the manufacturing process of semiconductor devices.

Japanese Patent No. 5641050

In recent years, integrated circuits such as LSIs have been designed to have higher density and lower voltage. For example, the current minimum wiring width is 5 nm, and it is said that it will be 3 nm in 2022. In addition, along with the increase in density of integrated circuits, the development of ultra-low voltage devices called ultra-low voltage LSIs with an operating voltage of about 0.4 V is also progressing. On the other hand, conventionally, few ESD countermeasures have been taken for the above-mentioned aluminum products, which are the main structural materials of manufacturing equipment. As the development of such ultra-low voltage devices progresses, there is a need to suppress the occurrence of surge voltages and surge currents that exceed the withstand voltage and allowable current when electrostatic discharge occurs between aluminum products and semiconductor devices. .

Therefore, an object of the present invention is to provide an aluminum material whose surface electrostatic discharge characteristics are adjusted, and an electrostatic discharge characteristic adjustment film for an aluminum material for adjusting the electrostatic discharge characteristics of the surface of the aluminum material.

In order to solve the above problems, an aluminum material according to the present invention includes an aluminum base material, a thickness provided on the surface of the aluminum base material of 1 μm or more and 100 μm or less, and a surface resistance value of 1×10 ⁸ Ω/ sq or more and less than 1×10 ¹³ Ω/sq, and a porous aluminum oxide layer provided on the porous aluminum oxide layer and having a surface resistance of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less. and a hard carbon film layer.

In the aluminum material according to the present invention, a non-conductive film having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less between the porous aluminum oxide layer and the hard carbon film layer. It is also preferable to have an intermediate layer consisting of

In the aluminum material according to the present invention, the surface resistance value of the hard carbon film layer is less than 1×10 ¹² Ω/sq, and the hard carbon film layer is amorphous containing carbon with sp2 structure and carbon with sp3 structure. It is preferably made of a carbon coating having a structure.

In the aluminum material according to the present invention, it is preferable that the thickness of the hard carbon film layer is 1 nm or more and 10 μm or less.

The aluminum material which concerns on this invention WHEREIN: It is also preferable that the said base materials made from aluminum are components made from aluminum used in contact with a semiconductor component, or adjoining in a semiconductor manufacturing process.

The electrostatic discharge property adjusting film for an aluminum material according to the present invention is an electrostatic discharge property adjusting film for an aluminum material provided on the surface of an aluminum substrate to adjust the electrostatic discharge property of the surface of the aluminum substrate. a porous aluminum oxide layer having a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq provided on the surface of an aluminum substrate; and a hard carbon film layer having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less provided on the high quality aluminum oxide layer.

The aluminum material according to the present invention includes a porous aluminum oxide layer having a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq, and the porous aluminum oxide layer A hard carbon film layer provided on the layer and having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less. By laminating these films on the surface of the aluminum base material, it is possible to make it difficult to generate static electricity, and when it is charged with static electricity, the static electricity can be discharged slowly. Therefore, aluminum parts that are used directly or in close proximity to objects to be protected from electrostatic discharge of semiconductors, electronic parts, and various electronic devices (semiconductor devices) constructed using these are As a result, it is possible to prevent surge current, voltage, etc., from being applied to the object to be protected, and to prevent malfunction and damage to the object to be protected due to electrostatic discharge. Therefore, according to the present invention, it is possible to provide an aluminum material whose surface electrostatic discharge characteristics are adjusted, and an electrostatic discharge characteristic adjustment film for an aluminum material for adjusting the electrostatic discharge characteristics of the surface of the aluminum material.

3 is a diagram showing a charge decay curve of the surface of the electrostatic discharge characteristic adjusting film (surface of the hard carbon film layer) on the aluminum material of Example 1. FIG. FIG. 10 is a diagram showing a charge attenuation curve on the surface of the electrostatic discharge property adjusting film (surface of the hard carbon film layer) on the aluminum material of Example 2; 3 is a diagram showing a charge attenuation curve on the surface of the porous aluminum oxide layer in the aluminum material of Comparative Example 1. FIG. FIG. 10 is a diagram showing a charge attenuation curve on the surface of the porous aluminum oxide layer in the aluminum material of Comparative Example 2; FIG. 2 is a diagram showing dielectric strength voltage of each example and each comparative example, and is a diagram illustrating a change in dielectric strength voltage depending on the presence or absence of a hard carbon film layer. FIG. 4 is a diagram showing the coefficient of friction of each example and each comparative example, and showing changes in the coefficient of friction depending on the presence or absence of a hard carbon film layer. FIG. 10 is a diagram showing the hardness of each example and each comparative example, showing changes in hardness depending on the presence or absence of a hard carbon film layer.

Embodiments of the aluminum material and the electrostatic discharge property-adjusting film for the aluminum material according to the present invention are described below.
1. Aluminum Material The aluminum material according to the present invention includes an aluminum base material, a thickness provided on the surface of the aluminum base material of 1 μm or more and 100 μm or less, and a surface resistance value of 1×10 ⁸ Ω/sq or more and 1× A porous aluminum oxide layer of less than 10 ¹³ Ω/sq, and a hard carbon film layer provided on the porous aluminum oxide layer and having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less. and

As described above, various aluminum products are used in the manufacturing process of semiconductor devices. Since aluminum is a metal, it is a conductor. The surface resistance value of the conductor is approximately 1×10 ⁻³ Ω/sq or less. Conductors do not generate static electricity or accumulate static charge on their surfaces. However, when a statically charged object comes into contact with a conductor, the charge on the surface of the object abruptly dissipates within a few nanoseconds. Therefore, when a semiconductor device charged with static electricity comes into contact with an aluminum product, electrostatic discharge occurs rapidly. At that time, if a surge voltage or surge current exceeding the withstand voltage or allowable current is applied to the semiconductor device, dielectric breakdown may occur, which may lead to damage such as malfunction or disconnection of the semiconductor device. However, in the past, little ESD countermeasures were taken for these aluminum products.

In the manufacturing process of semiconductor devices, it is necessary to suppress generation of dust. Alumite treatment is often performed as a treatment for increasing the surface hardness of aluminum products. When alumite treatment is applied, an alumite treatment layer containing aluminum oxide as a main component is provided on the surface of aluminum. The volume resistivity of aluminum oxide itself is about 10 ^14-15 Ω·cm, and aluminum oxide is an insulator. The volume resistivity of rubber is about 10 ¹⁰ Ω·cm to 10 ¹⁴ Ω·cm, and the specific volume resistivity of plastic is about 10 ¹⁴ Ω·cm to 10 ¹⁸ Ω·cm. Therefore, it is considered that when an aluminum product is anodized, the surface of the aluminum product exhibits electrostatic discharge characteristics similar to those of other insulators such as rubber and plastic.

Therefore, the present inventors first used an insulation resistance meter to measure the surface resistance value of an aluminum base material provided with an alumite treatment layer in order to study ESD countermeasures for aluminum products. As a result, the surface resistance value of the aluminum base material provided with the alumite treatment layer was approximately 1×10 ⁸ to 1×10 ¹³ Ω/sq. It is somewhat lower than the surface resistance of other insulators such as rubber and plastic, but higher than that of conductors. It should be noted that the surface resistance usually shows a value smaller than the volume specific resistance by one order of magnitude or more. Static electricity charges the surface of an object, and when it is discharged, the charge mainly flows on the surface of the object. Therefore, in the present invention, the resistance value of each layer is evaluated not by the fixed volume resistance value but by the surface resistance value.

If the surface resistance value is between a conductor and an insulator as described above, normally, even if it comes into contact with other objects, the generation of static electricity is suppressed and the speed of accumulation of static electricity is slow. It is considered that the slow charge characteristic is exhibited. In addition, if the surface resistance value is within the above range, it is considered that even if static electricity is applied to the surface, it exhibits slow discharge characteristics in which static electricity is slowly discharged. However, when the inventors of the present invention actually measure the charge decay behavior of the surface of an aluminum substrate provided with an anodized layer using a device for evaluating static charge decay (charge decay meter/honest meter) , it was confirmed that the surface charge of the alumite treated layer was several volts, but did not charge any more, and the charge dissipated immediately. That is, the inventors of the present invention have found that although the alumite treatment layer is an insulator, it exhibits electrostatic discharge characteristics different from those of other insulators such as rubber and plastic, and also differs from the electrostatic discharge characteristics assumed depending on the range of surface resistance values. We found a new finding that shows the behavior.

As a result of intensive studies by the present inventors, the reason why the anodized layer exhibits such peculiar electrostatic discharge characteristics is as follows. The anodized layer has a two-layer structure of a barrier film (non-porous film) of nm order (several nm to several tens of nm) and a porous film grown on the barrier film. Further, during the alumite treatment, a pore-sealing treatment is performed to close the micropores of the porous film. However, the micropores are not completely closed by the sealing treatment. Moreover, the electrolyte used in the alumite treatment, the metal complex used in the sealing treatment, and the like remain in the micropores. Therefore, it is presumed that the surface of the porous film exhibits a peculiar electrostatic discharge characteristic in which static electricity is dissipated through the micropores, although the surface exhibits a high resistance value.

Thus, even if an aluminum product is provided with an alumite treatment layer, it is not possible to obtain slow charge characteristics and slow discharge characteristics. Therefore, when a semiconductor device charged with static electricity comes into contact with the alumite treatment layer, the static electricity is discharged, generating a surge current and a surge voltage, which may damage the semiconductor device due to static electricity.

On the other hand, other insulators such as rubber and plastic are kneaded with conductive fine particles such as carbon particles to impart conductivity, thereby providing ESD countermeasures to these insulators. However, it is clear that the alumite treatment layer is not effective even if the same ESD measures as those of other insulators are taken.

Therefore, the inventors of the present invention have made further intensive research and found that a specific alumite treatment layer on the surface of an aluminum substrate has a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×10 ⁸ Ω/sq or more. A porous aluminum oxide layer having a surface resistance of less than 1×10 ¹³ Ω/sq is provided, and a hard carbon film layer having a surface resistance of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less is formed on the porous aluminum oxide layer. By providing it, it is possible to obtain a surface that exhibits slow charge characteristics and slow discharge characteristics, and it is possible to make it difficult to generate static electricity, and when it is charged with static electricity, it is possible to slowly discharge static electricity. came to.

The aluminum substrate, the hard carbon film layer, and the porous aluminum oxide layer will be described below in this order. Further, the aluminum material according to the present invention may have an intermediate layer made of a non-conductive film between the porous aluminum oxide layer and the hard carbon film layer for improving adhesion between the two layers. Therefore, the intermediate layer will also be described below.

1-1. Aluminum Substrate The aluminum substrate is a substrate made of aluminum metal or an aluminum alloy, and its size and shape are not particularly limited, and it may be plate-like or have a predetermined shape. The aluminum base material is also preferably an aluminum part that is used in contact with or in close proximity to a semiconductor part (semiconductor device) in a semiconductor manufacturing process. Examples of such aluminum products include jigs and parts made of aluminum or aluminum alloy. It can be applied to various aluminum products such as a pick-up nozzle for holding and fixing at a predetermined position, a transfer arm used for transferring to a predetermined position, and the like.

1-2. Hard Carbon Film Layer Next, the hard carbon film layer will be described. The hard carbon film layer is a layer made of a carbon-based hard film having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less. By providing the hard carbon film layer on the porous aluminum oxide layer described later, as described above, it is possible to make it difficult to generate static electricity on the surface of the aluminum material, and to gently discharge static electricity when it is charged. can be done. In addition to exhibiting a surface resistance value within the above range, the hard carbon film layer has the following electrical properties (charge voltage of surface charge, half-life time, dielectric strength voltage, etc.) and the following mechanical properties (hardness, friction coefficients, etc.). All of the values shown below are values measured after a hard carbon film layer was provided on an aluminum base material via a porous aluminum oxide layer (and an intermediate layer if provided with an intermediate layer).

(1) Electrical Characteristics a) Surface Resistance Value The surface resistance value of the hard carbon film layer is as described above. In the present invention, the resistance value is defined by the surface resistance value instead of the volume specific resistance value. The reason is as described above. When the surface resistance value is greater than 3×10 ⁴ Ω/sq, the volume specific resistance value of the material is generally greater than 1×10 ⁵ Ω·m. The hard carbon film layer has a surface resistance value of 1×10 ¹² Ω/sq or less, which is lower than that of insulators such as plastic and rubber. Therefore, it is possible to suppress the generation of static electricity when the hard carbon film layer slides against another object, and it is possible to obtain slow charge characteristics.

Here, when charged with static electricity, the surface resistance of the hard carbon film layer is 10 ¹¹ Ω from the viewpoint of quickly dissipating the electric charge to the extent that it does not cause malfunction or damage to the protected object due to electrostatic discharge. /sq or less, more preferably 10 ¹⁰ Ω/sq or less, and even more preferably 10 ⁹ Ω/sq or less. From the viewpoint of reducing the maximum value of surge voltage (current), the surface resistance is preferably 10 ⁵ Ω/sq or more.

However, the surface resistance value is a value measured using an RCJS-compliant insulation resistance meter (for example, Trek's Model 152-1 insulation resistance meter) in compliance with IEC61340 5-1.

b) Half-life When the hard carbon film layer is provided on the surface of the aluminum substrate via the porous aluminum oxide layer, the half-life of the surface charge should be approximately 1 millisecond or more and 60 seconds or less. is preferred. Here, the half-life of the surface charge is measured by preparing a test piece having the electrostatic discharge characteristic adjusting film on the surface of the base material, charging the test piece with a corona discharge field (10 kV), and then measuring the surface voltage or surge. It is the time until the maximum value (peak value) of voltage (or surge current) attenuates to 1/2.

Since static electricity is charged together with static electricity discharge, the speed of charge accumulation on the surface is slow and the charging voltage is low. As described above, the charging speed of static electricity is slow, and the charging speed is related to the decay speed of static electricity.

It is preferable to appropriately adjust this half-life according to the tact time in taking ESD countermeasures for aluminum products used in the manufacturing process of semiconductor devices and the like. The tact time is a value obtained by dividing the operating time of a manufacturing line per day by the production volume of semiconductor devices and the like per day. If the half-life of the surface charge of the hard carbon film becomes longer than the tact time, the charge accumulated on the surface cannot be sufficiently dissipated from one process to the next process, and the manufacturing of semiconductor devices etc. Sometimes, static electricity accumulates in semiconductor devices and the like. Therefore, it may not be possible to sufficiently suppress malfunctions and damages of semiconductor devices and the like due to electrostatic discharge, which is not preferable. From this point of view, the half-life of the surface charge of the hard carbon film is preferably 50 seconds or less, more preferably 40 seconds or less.

The above half-life is a value measured as follows. A test piece in which the hard carbon film layer is provided on the surface of an aluminum base material via a porous aluminum oxide layer is measured with a charge attenuation measuring device (for example, a charging charge attenuation measuring device manufactured by Shishido Electrostatic Co., Ltd. (honest meter H0110-C). )), and the value measured in accordance with JIS L1094. However, the surface of the hard carbon film layer is charged under the conditions of an applied voltage of 10 kV, a discharge time of 30 seconds, a discharge distance of 15 mm, a charge measurement distance of 20 mm, and a test piece size of 50 mm × 50 mm, until the charged voltage decays to 1/2. is the half-life. Even when an intermediate layer, which will be described later, is provided, the half-life of the hard carbon film layer is a value measured in the same manner.

c) Dielectric strength characteristics It is preferable that the hard carbon film layer has a high dielectric strength. A hard carbon film layer is provided on the surface of an aluminum substrate via a porous aluminum oxide layer, but if a voltage higher than the withstand voltage of the hard carbon film layer is applied, dielectric breakdown of the hard carbon film layer occurs. Once a dielectric breakdown occurs in the hard carbon film layer, that portion irreversibly becomes a good conductive region, and electrostatic discharge is likely to occur between the charged object and the dielectric breakdown region. Therefore, the higher the withstand voltage of the hard carbon film layer, the better. Specifically, it is preferably 30 kV/mm or more, preferably 50 kV/mm or more, and more preferably 70 kV/mm or more.

In addition, by providing the hard carbon film layer, the dielectric breakdown voltage can be improved by 10% or more compared to the case where only the porous aluminum oxide layer is provided on the aluminum substrate.

(2) Mechanical Properties a) Coefficient of Friction The coefficient of friction of the hard carbon film layer is preferably as low as possible. When the coefficient of friction is large, the heat generation temperature at the contact surface during sliding with the mating material becomes high. Heat generation is a waste of energy consumption. In addition, the heat generated softens the material, which increases the amount of wear, increases dust generation, and shortens the life of the sliding area. By forming an electrostatic discharge characteristic adjustment film using a hard carbon film layer with a low friction coefficient, it is suitable for aluminum materials used in parts that slide with other articles, for example, installed in clean rooms such as semiconductor manufacturing equipment. Thus, it is possible to obtain an aluminum material that is energy-saving as an ESD countermeasure, has low dust generation, and has a long service life. Specifically, the coefficient of friction is preferably 0.50 or less, more preferably 0.30 or less, even more preferably 0.25 or less, and even more preferably 0.20 or less. .

Further, by providing the hard carbon film layer, the coefficient of friction can be reduced to 50% or less compared to the case where only the porous aluminum oxide layer is provided on the aluminum substrate.

b) Hardness It is preferable that the hardness of the hard carbon film layer is high. Generally, the higher the hardness, the better the wear resistance, and the more difficult it is to wear when it comes into contact with, slides on, or separates from another object, and the generation of abrasion powder can be suppressed. Therefore, for example, it is suitable as an electrostatic discharge characteristic adjusting film for an aluminum material that is installed in a clean room such as a semiconductor manufacturing apparatus and used for a part that slides with other articles.

Further, by providing the hard carbon film layer, the hardness can be improved by 10% or more compared to the case where only the porous aluminum oxide layer is provided on the aluminum substrate.

(3) Structure of hard carbon film layer As long as the surface resistance value of the hard carbon film layer is within the above range, the lattice structure of carbon atoms in the hard carbon film layer is not particularly limited. Moreover, although the hard carbon film layer is a carbon-based film, it may contain an element other than carbon as an additive. As a hard carbon film layer having a surface resistance value within the above range, for example, an amorphous structure containing carbon with an sp2 structure typified by graphite and carbon with an sp3 structure typified by diamond in the lattice structure of carbon atoms. of carbon film. The hard carbon film layer constituting the electrostatic discharge property adjusting film is preferably made of this carbon film having an amorphous structure. In particular, it is preferable that the carbon film contains hydrogen and has an amorphous structure containing carbon of sp2 structure and carbon of sp3 structure.

a) Carbon content ratio of sp3 structure In order to develop the above electrical properties, the hard carbon film layer preferably has a carbon content ratio of sp3 structure of 20 (%) or more and 90 (%) or less, and 30 (%) ) or more and 80 (%) or less, and more preferably 35 (%) or more and 75 (%) or less. The electrical properties mentioned above mean that the surface resistance is greater than 3×10 ⁴ Ω and not more than 1×10 ¹² Ω. Further, it is more preferable that the half-life of the surface charge is 60 seconds or less.

In the hard carbon film layer, when the content ratio between the carbon content of the sp2 structure and the carbon content of the sp3 structure changes, the bandgap width changes and the surface resistance changes. As the carbon content of the sp2 structure increases, the bandgap width decreases and the surface resistance of the carbon film decreases. On the other hand, when the carbon content of the sp3 structure increases, the bandgap width increases and the surface resistance of the carbon film increases. If the carbon content ratio of the sp3 structure is 20(%) or more and 90(%) or less, the surface resistance can be set within the range of more than 3×10 ⁴ Ω and 1×10 ¹² Ω or less. Then, by changing the content ratio of the carbon content of the sp2 structure and the carbon content of the sp3 structure within the above range, the bandgap width can be changed, and the surface resistance value can be adjusted within the above range. be able to. Similarly, the half-life of the surface charge can be adjusted by adjusting the content of sp3-structured carbon.

b) Hydrogen content The hard carbon film layer preferably contains 0 atomic % or more and 50 atomic % or less of hydrogen. The charge conduction behavior across the bandgap is determined by the electron hopping phenomenon in the localized level (impurity level) generated within the bandgap. The localized levels are caused by the presence of impurities such as dangling bonds of carbon or additive elements (hydrogen etc.). Therefore, the electrical properties of the hard carbon film layer are determined not only by the content ratio of the carbon content of the sp2 structure and the carbon content of the sp3 structure, but also the amount of elements other than carbon such as the hydrogen content in the hard carbon film layer. It also changes depending on the content. Hydrogen bonds with carbon dangling bonds. Therefore, by adjusting the hydrogen content within the above range, the localized levels within the bandgap can be changed, and the electrical properties of the hard carbon film layer can be adjusted within the above range.

Further, mechanical properties such as hardness and friction coefficient can be adjusted by adjusting the hydrogen content in the hard carbon film layer. As the hydrogen content in the hard carbon film layer increases, the coefficient of friction of the hard carbon film layer decreases and the hardness tends to decrease.

In order to make the electrical properties and mechanical properties of the hard carbon film layer more preferable, the hydrogen content in the hard carbon film layer is more preferably 40 atm % or less, further preferably 30 atm % or less. .

c) Additive elements In addition to hydrogen, the hard carbon film layer contains N, F, Al, Si, Cr, Ag, Ti, Cu, Ni, W, Ta, Mo, Zr, B, Fe, Pt, P, One or more elements selected from the group consisting of S, I, Mg, Zn and Ge can be included as additive elements.

In addition to hydrogen, by including one or more elements selected from the group consisting of the elements listed above as additive elements, the localized levels can be changed, and surface resistance, surface charge half-life, etc. Electrical properties and mechanical properties such as coefficient of friction and hardness can be varied.

d) Film thickness The film thickness of the hard carbon film layer is preferably 1 nm or more and 10 µm or less. If the hard carbon film layer has the above electrical properties and mechanical properties, even if the film thickness of the hard carbon film layer is thin, it suppresses the generation of static electricity, gently dissipates the charge during electrostatic discharge, and improves the performance of the semiconductor device associated with electrostatic discharge. Damage and malfunction can be suppressed. The thickness of the hard carbon film layer can be appropriately adjusted depending on the application. For example, for applications that require wear resistance and the like in addition to countermeasures against static electricity, it is preferable that the thickness of the hard carbon film layer is thick. A thick film is also preferable when a higher dielectric strength voltage is required. This is because if the dielectric strength characteristics (kV/mm) are the same, the thicker the film, the higher the dielectric strength (kV) during use. Therefore, for applications requiring abrasion resistance, high dielectric strength voltage, etc., the film thickness of the carbon film is more preferably 10 nm or more, more preferably 50 nm or more. On the other hand, from the viewpoint of production efficiency and cost in obtaining a carbon film with uniform electrical properties, mechanical properties, film thickness, etc., the thickness of the hard carbon film layer is preferably 5 μm or less, and 3 μm or less. It is more preferable to have However, the thickness of the hard carbon film layer is not particularly limited as long as there is no cost limitation in applications where the wear resistance or the like is required.

1-3. Porous Aluminum Oxide Layer In the present invention, the porous aluminum oxide layer has a thickness of 1 μm or more and 100 μm or less, and is mainly composed of aluminum oxide having a surface resistance value of 1×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq. It is an anodized film produced by an anodizing method using an aluminum substrate as an anode. The porous aluminum oxide layer (anodic oxide film) consists of a nanometer-order barrier film present at the interface between the aluminum substrate and the porous aluminum oxide layer, and a porous film grown on the barrier film. I have. It is preferable that the micropores of the porous film are subjected to a sealing treatment, which will be described later.

By providing such a porous aluminum oxide layer on the surface of the aluminum substrate, it is possible to make it more difficult to generate static electricity compared to the case where the hard carbon film is directly provided on the surface of the aluminum substrate. can be discharged more slowly. For example, the half-life of the base material made of SUS (SUS304), which is a conductor, is about 2.5 nanoseconds. If the hard carbon film layer is provided directly on the SUS base material, the half-life becomes about 10 nanoseconds, and a certain degree of slow discharge characteristics can be obtained. Similar behavior is exhibited when aluminum substrates or other conductors are used as substrates. However, half-lives on the order of nanoseconds still result in steep dissipation of the electrostatic charge when charged. In the present invention, by providing a hard carbon film layer on an aluminum substrate via the porous aluminum oxide layer, the half-life can be increased to 1 millisecond or more and 60 seconds or less as described above. can be discharged slowly. Further, by providing the porous aluminum oxide layer, it is possible to improve surface mechanical properties such as hardness of the aluminum material.

In order to obtain these effects, the thickness of the porous aluminum oxide layer in the present invention is preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. On the other hand, when the porous film is grown with the thickness of the aluminized layer exceeding 100 μm, cracks are likely to occur. The thickness of the porous aluminum oxide layer can be appropriately adjusted, and can be 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, and the like.

In order to develop the above slow discharge characteristics, the porous aluminum oxide layer is required to have a surface resistance value of 3×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq. In order to obtain better slow discharge characteristics, the surface resistance of the porous aluminum oxide layer is preferably 9×10 ¹² Ω/sq or less, more preferably 5×10 ¹² Ω/sq or less, It is more preferably 1×10 ¹¹ Ω/sq or less, and even more preferably 5×10 ¹⁰ Ω/sq or less.

1-4. Intermediate Layer In the aluminum material according to the present invention, it is also preferable to provide an intermediate layer made of a non-conductive film between the porous aluminum oxide layer and the hard carbon film layer. The intermediate layer is mainly a layer for improving adhesion between the porous aluminum oxide layer and the hard carbon film layer. The anti-static property of the aluminum material also changes depending on the material of the intermediate layer. Even if the intermediate layer is a conductive film such as a metal layer, the adhesion between the hard carbon film layer and the porous aluminum oxide layer can be improved. However, when the intermediate layer is a conductive film such as a metal layer, even if a hard carbon film layer is provided on the conductive film, the slow charge characteristics and slow discharge characteristics are not exhibited, and the static electricity quickly dissipates. do. In other words, the significance of providing a hard carbon film layer on an aluminum substrate via a porous aluminum oxide layer is lost. On the other hand, by interposing an intermediate layer made of a non-conductive film between the porous aluminum oxide layer and the hard carbon film layer, it is possible to inhibit the flow of charges in the depth direction of the film, and the porous aluminum oxide layer It is possible to obtain better slow discharge characteristics while improving the adhesion between the layer and the hard carbon film layer.

In this way, when the intermediate layer is provided, the intermediate layer is preferably a non-conductive layer having a surface resistance value similar to that of the hard carbon film layer. If the surface resistance value of the intermediate layer is 1×10 ¹² Ω or more, the static electricity attenuation speed will be slow, and if it is 3×10 ⁴ Ω or less, the static electricity attenuation speed will be fast, and the effect of providing the electrostatic discharge characteristic adjustment film will be lost. , unfavorable. When the hard carbon film layer is provided on the porous aluminum oxide layer, if the main purpose is to obtain the effect of improving the adhesion, durability, and mechanical strength of the hard carbon film layer, the intermediate layer is a metal layer. However, the intermediate layer is required to be a non-conductive layer in order to effectively take measures against ESD. However, if the intermediate layer has an arbitrary layer structure and the porous aluminum oxide layer and the hard carbon film layer have good adhesion, the aluminum material does not have to include the intermediate layer.

As the non-conductive film constituting the intermediate layer, a film made of an oxide, carbide, boride material, or the like formed on the porous aluminum oxide layer by a sputtering method can be used. Alternatively, it may be a non-conductive film deposition film formed on the porous aluminum oxide layer by plasma CVD with introduction of gas. The non-conductive deposited film is, for example, a silicon compound film formed by plasma CVD using an organic silicon compound gas such as HMDSO (hexamethyldisiloxane O[Si(CH ₃ ) ₃ ] ₂ ) gas. can be done.

The thickness of the intermediate layer is preferably about 1 nm to 3 μm, and the thickness of the intermediate layer can be adjusted as appropriate. In addition, the intermediate layer is not limited to a single layer structure, and it is also preferable to use an intermediate layer having a layered structure in which a plurality of films are layered by stacking oxide and carbide compound films, for example.

1-5. Manufacturing Method The aluminum material according to the present invention described above can be manufactured as follows. However, the manufacturing method described below is an example for manufacturing the aluminum material according to the present invention, and the method for manufacturing the aluminum material according to the present invention is not limited to the following method.

(1) Substrate made of aluminum An aluminum substrate is prepared as an object to be surface-treated whose surface is to be provided with slow charge characteristics and slow discharge characteristics. The aluminum substrate can be any of the various aluminum products described above.

(2) Pretreatment Step First, the surface of the aluminum substrate is preferably subjected to pretreatment such as degreasing and alkali etching to clean the surface to be surface-treated. As the pretreatment, chemical pretreatment such as degreasing or alkali etching is preferably performed. It is also preferable to perform mechanical pretreatment such as surface polishing as necessary before chemical pretreatment to obtain a flat surface. When degreasing the surface of the aluminum base material, conventionally known methods such as an organic solvent method, a surfactant method, an acid degreasing method, an electric field degreasing method, an alkaline degreasing method, and an emulsion degreasing method can be appropriately used. can. Alkaline etching can also remove surface stains that cannot be removed by degreasing treatment, as well as naturally occurring oxide films on the surface of the aluminum base material. By flattening and cleaning the surface of the aluminum substrate in this manner, a porous aluminum oxide layer can be favorably formed on the alumite substrate.

(2) Porous aluminum oxide layer -Peroxide system, sodium phosphate system, etc.), mixed acid bath (sulfosalicylic acid-sulfuric acid system, sulfosalicylic acid-maleic acid system, etc.) A film can be formed by forming an anodized film on the surface of an aluminum base material by using a carbon plate or the like as an anode and using a carbon plate or the like as a cathode as described above. Aluminum (Al ³⁺ ) eluted from the surface of the aluminum substrate and oxygen (O ²⁻ ) generated by electrolysis combine to form an anodized film made of aluminum oxide (Al ₂ O ₃ ). .

As the anodized film grows, the surface of the aluminum substrate is eluted. The barrier film always exists at the interface between the aluminum substrate and the anodized film, and the porous film grows on the barrier film. The porous coating has a myriad of cells consisting of micropores and cell walls surrounding the micropores. Since the surface immediately after the anodized film is grown is chemically active, it is in a state where it easily reacts with oxygen in the air and other chemical substances. In addition, since the surface area is large due to the large number of fine pores, the physical adsorption is also high.

Therefore, it is preferable to form the porous aluminum oxide layer of the present invention by growing the anodized film to a predetermined thickness and then performing a sealing treatment. Chemical activity and physical adsorptivity can be reduced by sealing the micropores by a pore-sealing treatment. When performing the sealing treatment, conventionally known methods such as a hydration sealing method, an inorganic material filling method, an organic material filling method, and the like can be employed. As the hydration sealing method, for example, a steam sealing method using pressurized steam and a boiling water sealing method using boiling water can be adopted. Examples of inorganic filling methods include metal salt sealing methods using metal salts such as nickel acetate, cobalt acetate, potassium dichromate, sodium dichromate, and sodium silicate, and low-temperature sealing methods using metal salt-fluoride. Law can be adopted. As the organic filling method, a method using electrodeposition coating can be employed.

In addition, depending on the type of electrolytic solution for the anodized film, the method of sealing treatment (whether it is an organic material filling method or an inorganic material filling method, etc.), and the type of treatment liquid used for sealing treatment, etc. The surface resistance value of the aluminum layer fluctuates. By appropriately adjusting these, a porous aluminum oxide layer having a desired surface resistance value can be obtained.

(3) Hard carbon film layer The method of forming the hard carbon film layer is not particularly limited as long as a carbon-based hard film having the above electrical properties is obtained. A film is preferred. In addition, it is preferable to clean the surface of the porous aluminum oxide layer by dry cleaning or the like before forming the film by the following method.

a) Hydrogen-Containing Hard Carbon Film Layer The hard carbon film layer containing hydrogen can be formed by a CVD method (chemical vapor deposition method) or a PVD method (physical vapor deposition method). By introducing a hydrocarbon gas into the chamber when forming the hard carbon film layer, a hard carbon film layer containing hydrogen can be formed. As the hydrocarbon gas, chain hydrocarbons such as methane, propane, ethylene, and acetylene, and aromatic hydrocarbons such as benzene, toluene, and styrene can be used. In particular, it is preferable to use methane, acetylene, or the like. When using a carbon solid target made of graphite or the like, hydrogen gas may be introduced into the chamber.

As the CVD method, it is preferable to adopt a thermal CVD method and a plasma CVD method. The plasma CVD method includes various methods such as a high-frequency discharge method and an ion beam method depending on the plasma generation method, but the plasma generation method is not particularly limited as long as the desired hard carbon film layer can be formed. not something.

b) Hydrogen-Free Hard Carbon Film Layer The hydrogen-free hard carbon film layer is deposited by PVD using a carbon solid target. Specifically, by a sputtering method, an ion plating method, a hollow cathode method, a cathodic arc method, a laser ablation method, or the like, ionized argon atoms collide with a carbon solid target to eject carbon ions (sputtering), or arc discharge. , carbon is sublimated and ionized by laser irradiation to form a film on a substrate to which a negative voltage is applied. When hydrogen is desired to be added, a solid carbon target such as graphite is used as described above, hydrogen is introduced into the vacuum vessel to generate hydrogen plasma, and both carbon ions and hydrogen ions are deposited on the surface of the substrate. A hard carbon film layer containing hydrogen can be deposited on a substrate.

c) Additive Element-Containing Hard Carbon Film Layer To form a hard carbon film layer containing an additive element other than hydrogen, any of the various CVD methods and PVD methods described above can be employed. N, F, Al, Si, Cr, Ag, Ti, Cu, Ni, W, Ta, Mo, Zr, B, Fe, Pt, P, S, I, Mg, Zn and Ge are contained in the vacuum vessel. By using a gas containing one or more elements selected from the group or a target material, a hard carbon film layer or hydrocarbon film containing these additional elements can be obtained.

(4) Intermediate layer When providing an intermediate layer, as described above, it can be formed by a sputtering method, a plasma CVD method with introduction of a gas, or the like. When providing an intermediate layer, after forming a porous aluminum oxide layer, the surface is dry-cleaned, etc., and then an intermediate layer is formed. It is sufficient to form a film on the

2. Electrostatic Discharge Property Adjusting Film for Aluminum Material Next, the electrostatic discharge property adjusting film for aluminum material according to the present invention will be described. The electrostatic discharge property adjusting film for an aluminum material is a film provided to adjust the electrostatic discharge property of the surface of the aluminum substrate, and comprises the porous aluminum oxide layer and the hard carbon film layer. It is also preferable to provide the intermediate layer between the porous aluminum oxide layer and the hard carbonized film layer. The porous aluminum oxide layer, the hard carbon film layer, and the intermediate layer can all be the same as the above layers provided in the aluminum material according to the present invention.

The following effects can be obtained by providing the electrostatic discharge characteristic adjusting film according to the present invention on aluminum products (aluminum materials) used in semiconductor handling devices and the like. The surface resistance of the electrostatic discharge characteristic adjusting film is equivalent to that of the hard carbon film, and the slow charge characteristic and slow discharge characteristic can be imparted to the surface as described above. Therefore, it is possible to suppress the generation of static electricity when the semiconductor device is contacted, slid, or released from contact. In addition, the electrostatic discharge characteristic adjustment film has a laminated structure in which a hard carbon film is laminated on a porous aluminum oxide layer, and compared to the case where only one of these two layers is provided, the slow charge characteristics, Slow discharge characteristics become extremely good. Furthermore, as described above, by interposing an intermediate layer made of a non-conductive film between the porous aluminum oxide layer and the hard carbon film layer, the slow charge characteristics can be further improved.

In addition, by providing the electrostatic discharge characteristic adjusting film on the surface of the aluminum product, the hardness of the aluminum product can be improved, and the friction and wear characteristics can be improved. Therefore, even when the aluminum product and the semiconductor device slide against each other, the generation of abrasion powder is prevented, and when the circuit pattern is exposed when manufacturing a semiconductor integrated circuit, exposure failure of the circuit pattern caused by dust is suppressed. can do. In addition, even when the semiconductor device is charged with static electricity, the static electricity can be gently dissipated by the electrostatic discharge characteristic adjustment film, so the generation of surge voltage due to electrostatic discharge is suppressed, and the semiconductor device due to electrostatic discharge Device damage can be suppressed. In addition, it is possible to suppress the generation of electromagnetic waves due to electrostatic discharge, thereby preventing malfunction of semiconductor manufacturing equipment and the like. For these reasons, the yield in manufacturing semiconductors can be improved. In addition, depending on the tact time, by appropriately adjusting the carbon content ratio of the above sp3 structure of the carbon film constituting the hard carbon film layer, the hydrogen content, the type of additive element, the amount added, the intermediate layer, etc., electrostatic discharge By adjusting the half-life of the surface charge of the property-adjusting film, it is possible to gently discharge static electricity until the semiconductor is transported to the next process, while preventing the accumulation of static electricity on the semiconductor.

Hereinafter, the aluminum material and the electrostatic property adjusting film for aluminum material according to the present invention will be described with examples, but the aluminum material and the electrostatic property adjusting film for aluminum material according to the present invention are limited to the following examples. not a thing

(1) Production of aluminum material (electrostatic discharge characteristic adjustment film treatment)
In Example 1, an anodized film was grown to 15 μm on an aluminum substrate (aluminum alloy substrate A5052) using a sulfuric acid bath as an electrolytic solution for anodization, and then a nickel acetate solution was used for sealing. was provided with a porous aluminum oxide layer. A hard carbon film layer was formed on the porous aluminum oxide layer by the RF/high voltage pulse superposition type PBIID method.

The specific steps are as follows. First, the surface of a polished A5052 aluminum substrate having a size of 50 mm×50 mm and a thickness of 2 mm was subjected to degreasing and alkali etching treatment. An anodized film of aluminum oxide was grown to 15 μm on the aluminum substrate by an anodizing method using the aluminum substrate after the pretreatment as an anode and a carbon plate as a cathode in a sulfuric acid bath. After that, a pore-sealing treatment was performed with a nickel acetate solution to close the micropores of the porous film, thereby forming the porous aluminum oxide layer of the present invention. Next, the surface of the aluminum base material provided with the porous aluminum oxide layer was cleaned by ultrasonic cleaning with ethanol for 5 minutes, and the surface was dried with a dryer.

Next, a hard carbon film layer was provided on the porous aluminum oxide layer as follows. First, an aluminum substrate provided with a porous aluminum oxide layer was set at a predetermined position in a chamber of a PBIID apparatus (plasma ion implantation/film formation apparatus). Then, the inside of the chamber was evacuated to 4 mPa by a turbomolecular vacuum pump. Next, 200 sccm (Standard Cubic Centimeter per Minute) of argon gas was introduced into the chamber, and a high-frequency voltage was applied to carry out argon bombardment under conditions of 3 kW and 20 minutes to dry clean the surface of the porous aluminum oxide layer. After argon bombardment, a gas obtained by vaporizing HMDSO was introduced into the chamber at 150 sccm, and a SiC-based film of several tens of nm was formed for 5 minutes at 0.5 Pa and PF power of 2 kW to form an intermediate layer. After that, 100 sccm of acetylene was introduced, plasma discharge was performed with RF power of 2 kW, a high voltage pulse of −10 kV with a pulse width of 5 μs was applied to the substrate, and a hard film with a thickness of about 2 μm was deposited on the intermediate layer for 90 minutes at a pressure of 0.5 Pa. A carbon film layer was deposited. The substrate temperature during film formation was 150°C. Through a series of these treatments, an electrostatic discharge characteristic adjusting film consisting of a porous aluminum oxide layer, an intermediate layer and a hard carbon film layer was provided on the surface of the aluminum base material to obtain an aluminum material. Hereinafter, a treatment for providing an electrostatic discharge property adjusting film consisting of a porous aluminum oxide layer, an intermediate layer and a hard carbon film layer on the surface of an aluminum substrate is referred to as electrostatic discharge property adjusting film treatment.

(2) Id/Ig value of hard carbon film layer Based on Raman spectroscopy (Reinshaw in Via Reflex) at a laser wavelength of 532 nm, the G band (Ig), which indicates carbon with an sp2 structure in the hard carbon film layer, and lattice defects, etc. The ratio (Id/Ig) of the D band (Id) was measured. The measured result (Id/Ig) ratio was about 1.4.

(3) Content of additive elements When measured by ERDA (Elastic Recoil Detection Analysis: SSDH-2 (accelerator), RBS-400 (measuring device)), the hydrogen content was about 22.6 at%. rice field.

(4) Physical properties i) Electrical properties The surface resistance value of the aluminum material of Example 1, in which the surface of the aluminum base material was subjected to the electrostatic discharge characteristic adjustment film treatment as described above, was measured by an insulation resistance meter (Insulation manufactured by Trek). When measured using a resistance meter MODEL 152-1), it was about 2×10 ⁹ Ω.

Further, the half-life of the surface charge of the electrostatic discharge property adjusting film on the aluminum material of Example 1 was measured as follows. Using a charge attenuation measuring device (Electrification charge attenuation measuring device Honest meter H-0110-C manufactured by Shishido Electrostatic Co., Ltd.), the surface was measured under the conditions of a corona charging voltage of 10 kV, a discharge time of 30 seconds, a discharge distance of 15 mm, and a charge measurement distance of 20 mm. It was charged and the change in surface potential was measured. The maximum surface potential of the electrostatic discharge characteristic adjusting film in Example 1 was about 100 V, the half-life was about 0.7 seconds, and the corona discharge showed slow charge characteristics and slow discharge characteristics (see FIG. 1).

Furthermore, when the aluminum material of Example 1 was sandwiched between electrodes in the film thickness direction and a voltage was applied and measured with a voltmeter, the dielectric strength characteristic of the electrostatic discharge characteristic adjustment film was about 73 kV / mm (see FIG. 5). ).

ii) Mechanical properties The coefficient of friction of the aluminum material of Example 1 was measured by the ball-on-disk method using high-carbon steel balls (SUJ2) and alumina balls as mating materials at a load of 10 N and a linear velocity of 100 mm/sec. Both surface friction coefficients of the property-adjusting coatings were approximately 0.17 (see FIG. 6).

The hardness of the surface of the aluminum material of Example 1, that is, the hardness of the surface of the electrostatic discharge property adjusting film was measured by micro-Vickers (AKASHI) and found to be about 747 Hv (see FIG. 7).

(1) Production of aluminum material (electrostatic discharge characteristic adjustment film treatment)
In Example 2, on the same aluminum substrate A5052 as the aluminum substrate used in Example 1, an anodized film was grown to 15 μm using an oxalic acid bath as an electrolytic solution for anodization, and then a potassium dichromate solution was applied. A porous aluminum oxide layer was provided by performing a pore-sealing treatment. A hard carbon film layer was formed on this porous aluminum oxide layer by plasma CVD.

The specific steps are as follows. After preparing the same aluminum substrate as in Example 1 and performing pretreatment, the same procedure as in Example 1 was performed except that an oxalic acid bath was used, and an anodized film of aluminum oxide was formed on the aluminum substrate to a thickness of 15 μm. grown up. After that, the sealing treatment was performed in the same manner as in Example 1 except that a potassium dichromate solution was used, the surface was washed and dried, and then a hard carbon film layer was formed on the porous aluminum oxide layer by the following procedure. was established.

Next, an intermediate layer and a hard carbon film layer were provided on the porous aluminum oxide layer as follows. First, an aluminum substrate provided with a porous aluminum oxide layer was set at a predetermined position in a chamber of a high-frequency plasma deposition apparatus. Then, the inside of the chamber was evacuated to 1×10 ⁻³ Pa by a diffusion vacuum pump. Then, 60 sccm (Standard Cubic Centimeter per Minute) of argon gas was introduced into the chamber, and a high frequency voltage was applied to carry out argon bombardment at 900 W for 20 minutes to dry clean the surface of the porous aluminum oxide layer. After the argon bombardment, an intermediate layer of several tens of nanometers was coated with a SiC-based film by a sputtering method at 2 kW for 5 minutes. After that, acetylene was introduced at 10 sccm, and a hard carbon film layer having a thickness of about 600 nm was formed on the intermediate layer under the conditions of RF power of 500 W, pressure of 0.1 Pa, and 90 minutes. The substrate temperature during film formation was 70°C.

(2) Id/Ig value of hard carbon film layer In the same manner as in Example 1, by Raman spectroscopy, the G band (Ig) indicating carbon of the sp2 structure in the hard carbon film layer and lattice defects etc. The ratio (Id/Ig) of the D band (Id) was measured. The measured result (Id/Ig) ratio was about 1.3.

(3) Additive Element Content When the hydrogen content was measured in the same manner as in Example 1, the hydrogen content was about 26 atm %.

(4) Physical properties i) Electrical properties The surface resistance of the aluminum material of Example 2, in which the surface of the aluminum substrate was subjected to the electrostatic discharge property adjustment film treatment as described above, was measured in the same manner as in Example 1. It was about 4×10 ⁹ Ω.

In addition, the half-life of the surface charge of the electrostatic discharge characteristic adjusting film on the aluminum material of Example 2 was measured in the same manner as in Example 1 based on the change in surface potential. The maximum surface potential of the electrostatic discharge characteristic adjusting film in Example 2 was 160 V, the half-life was 0.5 seconds, and the corona discharge exhibited slow charge characteristics and slow discharge characteristics (see FIG. 2).

Furthermore, when the withstand voltage characteristic of the electrostatic discharge characteristic adjusting film on the aluminum material of Example 2 was measured in the same manner as in Example 1, it was about 128 kV/mm (see FIG. 4).

ii) Mechanical properties The coefficient of friction of the aluminum material of Example 2 was measured in the same manner as in Example 1 using high-carbon steel balls (SUJ2) and alumina balls as counterpart materials. The coefficients were approximately 0.19 and 0.14, respectively (see FIG. 5).

Further, when the hardness of the surface of the aluminum material of Example 2, that is, the hardness of the surface of the electrostatic discharge characteristic adjusting film was measured in the same manner as in Example 1, it was about 606 Hv (see FIG. 7).

Comparative example

(1) Manufacture of aluminum material (anodic oxide film treatment)
On the same aluminum substrate A5052 as the aluminum substrate used in Example 1, using a sulfuric acid bath and an oxalic acid bath as electrolytes for anodization, each anodized film was grown to a thickness of 15 μm, and then sealed with a nickel acetate solution. Aluminum materials of Comparative Examples 1 and 2 were obtained by performing the treatment to form a porous aluminum oxide layer.

(2) Physical properties i) Electrical properties The surface resistance value of the aluminum material of Comparative Example 2 provided with an aluminum layer was measured using an insulation resistance meter (Insulation resistance meter MODEL 152-1 manufactured by Trek) and found to be about 2×10 ¹⁰ Ω and 3×10 ^{10 Ω} , respectively. was Ω.

In addition, the half-life of the surface charge of the porous aluminum oxide layer in the aluminum materials of Comparative Examples 1 and 2 was measured in the same manner as in Example 1 based on the change in surface potential. The maximum surface potentials of the porous aluminum oxide layers in Comparative Examples 1 and 2 were 8 V (FIG. 3) and 9 V (FIG. 4), and almost no charges were accumulated on the surfaces of the porous aluminum oxide layers.

Further, when the withstand voltage characteristics of the porous aluminum oxide layers in the aluminum materials of Comparative Examples 1 and 2 were measured in the same manner as in Example 1, they were approximately 49 kV/mm and 73 kV/mm, respectively (see FIG. 5). .

ii) Mechanical properties The friction coefficient of the porous aluminum oxide layer surface was measured in the same manner as in Example 1, using the aluminum materials of Comparative Examples 1 and 2 as counterparts made of high-carbon steel balls (SUJ2). They were about 0.8 and 0.93, respectively. Next, when the friction coefficient was measured by the ball-on-disk method under the same conditions using alumina balls as the mating material, both friction coefficients were about 0.8 (see FIG. 5).

When the hardness of the surface of the porous aluminum oxide layer in the aluminum materials of Comparative Examples 1 and 2 was measured with a micro Vickers hardness tester (AKASHI), both were about 550 Hv (see FIG. 7).

[evaluation]
The maximum surface potential of the aluminum materials of Examples 1 and 2 was increased to 100 V and 100 V, respectively, by applying an electrostatic discharge property adjustment film treatment in which a hard carbon film layer is laminated on an aluminum substrate via a porous aluminum oxide layer. It was confirmed that the voltage can be set to 160 V, and that the potential (about 3 kV) normally assumed in an insulator is much lower than the maximum surface potential, and that it has a slow charge characteristic. In addition, the half-lives of the electrostatic discharge characteristic adjustment films on the aluminum materials of Examples 1 and 2 were 0.7 seconds and 0.5 seconds (see FIGS. 1 and 2), which is the half-life normally assumed for conductors. It was also confirmed that the period (on the order of nanoseconds) can be set to 1 millisecond or longer, and that it has slow discharge characteristics.
On the other hand, in the aluminum materials of Comparative Examples 1 and 2, which do not have a hard carbon film layer, the porous aluminum oxide layer is the outermost surface. In this case, it is confirmed that no charge accumulates on the surface of the porous aluminum layer (see FIGS. 3 and 4), and while it does not generate static electricity, it dissipates the charge immediately when a voltage is applied. In other words, when a semiconductor device charged with static electricity comes into contact with the aluminum materials of Comparative Examples 1 and 2, a sudden electrostatic discharge occurs in the porous aluminum layer, and a surge current and a surge voltage may occur. .

As shown in FIG. 5, when only a porous aluminum oxide layer is provided on an aluminum substrate (Comparative Examples 1 and 2), and when a porous aluminum oxide layer and a hard carbon film layer are provided on an aluminum substrate, Comparing the cases (Examples 1 and 2), by providing a hard carbon film layer on the porous aluminum oxide layer, that is, the electrostatic discharge property adjusting film according to the present invention is provided on the surface of the aluminum substrate As a result, it was confirmed that the withstand voltage can be improved by 10% or more compared to the case where only the porous aluminum oxide layer is provided on the surface of the aluminum substrate.

Further, as shown in FIG. 6, comparing Comparative Examples 1 and 2 with Examples 1 and 2, it can be seen that by providing a hard carbon film layer on the porous aluminum oxide layer, that is, according to the present invention, It was confirmed that by providing the electrostatic discharge characteristic adjusting film on the surface of the aluminum substrate, the coefficient of friction is reduced to 50% or less compared to the case where only the porous aluminum oxide layer is provided on the surface of the aluminum substrate. .

Furthermore, comparing Comparative Examples 1 and 2 with Examples 1 and 2 as shown in FIG. It was confirmed that by providing the electrostatic discharge characteristic adjusting film on the surface of the aluminum substrate, the hardness is improved by 10% or more compared to the case where only the porous aluminum oxide layer is provided on the surface of the aluminum substrate.

According to the present invention, it is possible to provide an aluminum material having surface electrostatic discharge characteristics adjusted, and an electrostatic discharge characteristics adjusting film for an aluminum material for adjusting the electrostatic discharge characteristics of the surface of the aluminum material. According to the present invention, since it is possible to impart slow charge characteristics and slow discharge characteristics to the surface of an aluminum material, it is suitable for aluminum products used in processes such as semiconductor device manufacturing processes where ESD countermeasures are strongly required. is.

Claims (6)

an aluminum substrate;
a porous aluminum oxide layer having a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq provided on the surface of the aluminum substrate;
a hard carbon film layer provided on the porous aluminum oxide layer and having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less;
An aluminum material characterized by: An intermediate layer comprising a non-conductive film having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less is provided between the porous aluminum oxide layer and the hard carbon film layer. 2. The aluminum material according to 1. The surface resistance value of the hard carbon film layer is less than 1×10 ¹² Ω/sq, and the hard carbon film layer is composed of a carbon film having an amorphous structure containing carbon with an sp2 structure and carbon with an sp3 structure. The aluminum material according to claim 1 or 2. The aluminum material according to any one of claims 1 to 3, wherein the hard carbon film layer has a thickness of 1 nm or more and 10 µm or less. The aluminum material according to any one of claims 1 to 4, wherein the aluminum base material is an aluminum part used in contact with or in close proximity to a semiconductor part in a semiconductor manufacturing process. An electrostatic discharge property adjusting film for an aluminum material provided on the surface of an aluminum substrate for adjusting the electrostatic discharge property of the surface of the aluminum substrate,
a porous aluminum oxide layer having a thickness of 1 μm or more and 100 μm or less and a surface resistance value of 1×10 ⁸ Ω/sq or more and less than 1×10 ¹³ Ω/sq provided on the surface of the aluminum substrate;
a hard carbon film layer provided on the porous aluminum oxide layer and having a surface resistance value of 3×10 ⁴ Ω/sq or more and 1×10 ¹² Ω/sq or less;
An electrostatic discharge property adjusting film for an aluminum material, comprising:

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