JP2023044211A - Master disk for electroforming, production method of master disk for electroforming, and production method of electroformed object - Google Patents

Abstract

[Problem] To provide an electroforming master that has excellent adhesion to an electroformed product and is capable of suppressing peeling of the electroformed product during growth, a method for manufacturing said electroforming master, and a method for manufacturing an electroformed product using said electroforming master. [Solution] An electroforming master that includes an n-type semiconductor and is provided with a substrate having a pattern on its surface, an oxide film is formed on said surface, and the thickness of said oxide film is 18 Å or less, a method for manufacturing said electroforming master, and a method for manufacturing an electroformed product using said electroforming master. [Selected Figure] Figure 1

Description

TECHNICAL FIELD The present disclosure relates to an electroforming master, a method for manufacturing an electroforming master, and a method for manufacturing an electroformed article.

Electroforming is widely used as a method for manufacturing parts, molds, etc. having various shapes. In the electroforming method, a master having a pattern on its surface is used, and an electroformed product is manufactured by electroforming nickel or the like on the master.
For example, Patent Document 1 discloses a plurality of mold structures made of silicon formed on a substrate made of silicon and having sidewalls substantially perpendicular to the substrate surface, and an insulator covering the sidewalls and upper surfaces of the mold structures. , and a support substrate that supports the mold structure via an insulating connection layer, the insulating connection layer connecting the lower surface of the mold structure and the upper surface of the support substrate, and the insulating connection layer that is not in contact with the mold structure. An electroforming mold is disclosed that is characterized by having recesses that are at least partially removed.

An oxide film is formed on the surface of the master over time, and the presence of the oxide film between the growing electroformed product and the master reduces the adhesive force of the electroformed product to the master, and the electroformed product is manufactured. There was a possibility that it would peel off in the middle. Therefore, as described in Patent Document 2, the oxide film is removed from the master using an acid such as hydrofluoric acid before manufacturing the electroformed product.

Japanese Patent Application Laid-Open No. 2005-256110 JP 2007-287216 A

For the purpose of controlling the shape of an electroformed object, a pattern formed by an insulating film is sometimes provided on the surface of the master.
The present inventor believes that the removal of an oxide film using acid is difficult to control, and that when the oxide film is removed with acid from a master plate having a pattern formed of an insulating film, even the pattern is removed. It was found that there is a risk of
Then, the present inventor improves the adhesion of the electroformed material to the electroforming master by adjusting the thickness of the oxide film on the surface of the substrate provided on the electroforming master without removing the oxide film with acid. found that it can be done.

The problem to be solved by one embodiment of the present disclosure is an electroforming master that has excellent adhesion to an electroformed product and can suppress peeling of the growing electroformed product, a method for manufacturing the above-mentioned electroforming master, and An object of the present invention is to provide a method for manufacturing an electroformed product using the above-described electroforming master.

Specific means for solving the problem are as follows.
<1> A master plate for electroforming, comprising a substrate containing an n-type semiconductor and having a pattern on its surface, an oxide film being formed on the surface, the oxide film having a thickness of 18 Å or less.
<2> The master disc for electroforming according to <1> above, wherein the oxide film includes a hydroxyl terminal group.
<3> The master plate for electroforming according to <1> or <2> above, wherein the contact angle of the oxide film with water at 23° C. is 40° or less.
<4> The master for electroforming according to any one of <1> to <3>, wherein the n-type semiconductor is a silicon-based semiconductor.
<5> The master disc for electroforming according to any one of <1> to <4>, wherein the pattern is formed of an inorganic insulating film.
<6> The master plate for electroforming according to <5> above, wherein the inorganic insulating film is a silicon-based oxide film.
<7> The master plate for electroforming according to <5> or <6> above, wherein the inorganic insulating film has a thickness of 0.1 μm or more.
<8> The master plate for electroforming according to any one of <1> to <7> above, wherein the oxide film has a thickness of 2 Å or more.
<9> A step of forming an oxide film having a thickness of 18 Å or less by subjecting the surface of the substrate containing an n-type semiconductor and having a pattern on the surface to dry etching and then exposing it to the atmosphere. A method of manufacturing a master for electroforming, including
<10> The master disc for electroforming according to <9> above, wherein the exposure time is 19 hours or less under the conditions of 1 atm, 23°C ± 2°C, and 50% RH ± 5% RH. manufacturing method.
<11> The master plate for electroforming according to <9> or <10> above, wherein the dry etching is performed using one or more gases selected from the group consisting of a rare gas, a fluorine-based gas, and a chlorine-based gas. manufacturing method.
<12> The step of forming the oxide film includes immersing the base material in sulfuric acid/hydrogen peroxide mixture, UV ozone treatment, and oxygen gas plasma treatment after dry etching and before exposure to the atmosphere. The method for producing a master for electroforming according to any one of <9> to <11> above, comprising applying one or more treatments selected from the group consisting of:
<13> Using the electroforming master according to any one of the above <1> to <8> as a cathode, an electroforming object is formed on the surface of the electroforming master on which the oxide film is formed in an electroforming liquid. and a step of separating the electroformed article from the electroforming master.
<14> including a step of cleaning the electroforming master after the step of peeling,
The method for producing an electroformed article according to <13> above, wherein a cycle including the cleaning step, the electroformed article forming step, and the peeling step is performed multiple times.

According to the present disclosure, an electroforming master which has excellent adhesion to an electroformed object and can suppress peeling of the growing electroformed object, a method for producing the electroforming master, and the electroforming master using the electroforming master A method for manufacturing an electroformed article can be provided.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the master disc for electroforming of the present disclosure. 2(A) to 2(E) are schematic cross-sectional views showing an embodiment of a method for manufacturing a substrate having a pattern on its surface. 1 is a schematic cross-sectional view showing an embodiment of an electroforming master and an electroformed article formed on the surface of the electroforming master. FIG.

In the present disclosure, the numerical range indicated using "-" includes the numerical values before and after "-" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, the upper limit or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described step by step. . Moreover, in the numerical ranges described in the present disclosure, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.

In this disclosure, "n-type semiconductor" refers to a semiconductor in which free electrons are used as carriers to carry charge.

In the present disclosure, the “thickness of oxide film” is measured as follows.
The thickness of the oxide film is determined using an ellipsometer in the air at 23° C.±2° C. and 50% RH±5% RH. As the ellipsometer, an automatic ellipsometer DVA-36L manufactured by Mizojiri Kogaku Kogyo Co., Ltd. or a similar device can be used.
Incidentally, the thickness of the inorganic insulating film and the like, which will be described later, is also measured by the above method.

(Master disk for electroforming)
An electroforming master of the present disclosure includes a substrate containing an n-type semiconductor and having a pattern on its surface, and an oxide film is formed on the surface, and the oxide film has a thickness of 18 Å or less.

The master plate for electroforming of the present disclosure has excellent adhesion to an electroformed product, and can suppress peeling of the growing electroformed product.

The reason why the above effects are exhibited is presumed as follows, but is not limited thereto.
The thickness of the oxide film formed on the surface of the substrate included in the master for electroforming of the present disclosure is 18 Å or less. By setting the thickness of the oxide film to 18 Å or less, the decrease in the electrostatic attraction between the substrate and the electroformed object growing on the oxide film is suppressed. , It is presumed that the adhesion to the electroformed product is excellent, and peeling of the electroformed product during growth is suppressed.
In addition, when an oxide film is not formed on the surface of the electroforming master, it becomes difficult to separate the manufactured electroformed product from the electroforming master, which may cause cohesive failure of the electroformed product or the electroforming master. . It is presumed that the presence of the oxide film improves the adhesive strength between the electroformed article and the electroforming master plate, so that the separation can be performed while suppressing the occurrence of cohesive failure or the like.

The pattern provided on the surface of the substrate is not particularly limited, and is preferably adjusted appropriately according to the application of the electroformed article to be produced. A pattern forming method will be described later.

From the viewpoint of improving the adhesion between the electroforming master of the present disclosure and the electroformed product, the thickness of the oxide film is preferably 17 Å or less, more preferably 15 Å or less, and further preferably 13 Å or less. It is preferably 10 Å or less, and particularly preferably 10 Å or less.
The thickness of the oxide film is preferably 0.5 Å or more, more preferably 1 Å or more, still more preferably 2 Å or more, and particularly preferably 5 Å or more.
If an oxide film is not formed on the surface of the electroforming master, it is difficult to separate the manufactured electroformed product from the electroforming master, and cohesive failure or the like of the electroformed product or the electroforming master may occur.
When the thickness of the oxide film is 0.5 Å or more, the adhesive force between the electroformed article and the master plate for electroforming is improved, and the separation can be performed while suppressing the occurrence of cohesive failure or the like.
In addition, since the thickness of the oxide film is 0.5 Å or more, it is possible to suppress entrapment of air bubbles between the oxide film and the electroformed product when forming the electroformed product on the oxide film. It is possible to suppress the occurrence of defects due to an increase in the surface roughness of the electroformed product due to the generated air bubbles.
The thickness of the oxide film can be adjusted by adjusting the exposure time of the base material after dry etching, which will be described later, to the atmosphere.

The oxide film preferably contains a hydroxyl terminal group (--OH).
Since the oxide film contains hydroxyl terminal groups (—OH), the hydrophilicity of the surface of the oxide film can be improved, and the entrapment of the air bubbles can be suppressed. It is possible to suppress the increase in roughness and the occurrence of defects.

Whether or not the oxide film has hydroxyl terminal groups is determined by X-ray photoelectron spectroscopy (XPS).
Specifically, it is confirmed whether hydroxyl groups derived from silanol groups are detected on the oxide film surface under the following measurement conditions using an X-ray photoelectron spectrometer.
In XPS, the X-ray source is monochromatic Al Kα rays, the X-ray spot diameter is 100 μm, and the photoelectron escape angle is 90° (inclination of the detector with respect to the oxide film surface).
XPS uses an X-ray photoelectron spectrometer, for example, Axis-Ultra manufactured by Shimadzu Corporation or a similar device can be used.

The contact angle of the oxide film with water at 23° C. is preferably 40° or less, more preferably 35° or less, even more preferably 30° or less, and particularly preferably 20° C. or less. .
By setting the contact angle of the oxide film with water at 23° C. to 40° or less, it is possible to suppress the entrapment of the air bubbles, and the entrapped air bubbles increase the surface roughness of the electroformed product and cause defects. You can prevent it from happening.

In the present disclosure, the “water contact angle of the oxide film at 23° C.” is measured by the air droplet method using a contact angle meter with a water droplet volume of 1 μL.
As the contact angle meter, for example, DMo-701 manufactured by Kyowa Interface Science Co., Ltd. or a similar device can be used.

The n-type semiconductor contained in the substrate is not particularly limited, and conventionally known n-type semiconductors can be used. Examples of n-type semiconductors include silicon compounds (silicon-based semiconductors), fullerene compounds, electron-deficient phthalocyanine compounds, condensed polycyclic compounds (naphthalenetetracarbonyl compounds, perylenetetracarbonyl compounds, etc.), TCNQ compounds (tetracyanoquinodimethane compounds etc.), polythiophene compounds, benzidine compounds, carbazole compounds, phenanthroline compounds, and the like.
Among those mentioned above, the n-type semiconductor is preferably a silicon-based semiconductor from the viewpoint of improving the adhesiveness to the electroformed product. Examples of silicon-based semiconductors include monocrystalline silicon, polycrystalline silicon, amorphous silicon, and polysilicon.

From the viewpoint of improving adhesion to an electroformed product, the thickness of the substrate is preferably 50 μm to 1,500 μm, more preferably 300 μm to 1,000 μm, and more preferably 500 μm to 750 μm. More preferred.

The pattern provided on the substrate surface is preferably formed of an inorganic insulating film.
By forming the pattern provided on the substrate surface with the inorganic insulating film, electroforming of nickel or the like on the pattern can be suppressed, and an electroformed product having a desired shape can be formed.

The inorganic insulating film forming the pattern is preferably a silicon-based oxide film. For example, the inorganic insulating film can be an inorganic insulating film formed from silane dioxide.
Since the inorganic insulating film is a silicon-based oxide film, electroforming of nickel or the like on the pattern can be further suppressed, and an electroformed product having a desired shape can be produced. Further, since the inorganic insulating film is a silicon-based oxide film, the adhesion to the substrate can be improved. Furthermore, according to the electroforming master plate including the base material having the pattern, when the formed electroformed product is peeled off from the electroforming master plate, it is possible to suppress the pattern from being peeled off, and the pattern can be reused. Since there is no need for forming, it is suitable for continuous production of electroformed products and is preferred.
As the silicon-based oxide film, a film containing an oxide of the silicon-based semiconductor can be used.

From the viewpoint of suppressing electroforming of nickel or the like, the thickness of the inorganic insulating film is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more.
The upper limit of the thickness of the inorganic insulating film is not particularly limited, and can be, for example, 10 μm or less.

One embodiment of the master disc for electroforming of the present disclosure will be described below with reference to FIG.
An electroforming master 10 of the present disclosure includes a substrate 12 having an oxide film 11 formed thereon. The substrate 12 has a pattern 13 on its surface.
Although the oxide film 11 is not formed on the surface of the pattern 13 in FIG. 1, the oxide film 11 may be formed partially or entirely on the surface of the pattern 13 .

(Manufacturing method of master disk for electroforming)
In the method for producing an electroforming master of the present disclosure, the surface of a substrate containing an n-type semiconductor and having a pattern on the surface is subjected to dry etching, and then exposed to the atmosphere, thereby increasing the thickness. A step of forming an oxide film of 18 Å or less is included.

According to the method of manufacturing a master for electroforming according to the present disclosure, it is possible to manufacture a master for electroforming that has excellent adhesiveness to an electroformed product and can suppress peeling of the growing electroformed product.
The reason why the above effects are exhibited is presumed as follows, but is not limited thereto.
A master for electroforming manufactured by the method for manufacturing a master for electroforming according to the present disclosure includes a substrate, and an oxide film having a thickness of 18 Å or less is formed on the surface of the substrate. By setting the thickness of the oxide film to 18 Å or less, the decrease in electrostatic attraction between the substrate and the electroformed object growing on the oxide film is suppressed. It is presumed that it has excellent adhesion to castings and suppresses peeling of electroformed products during growth.

Further, according to the electroforming master manufactured by the manufacturing method of the electroforming master according to the present disclosure, when forming the electroformed product on the oxide film, entrapment of air bubbles between the oxide film and the electroformed product is suppressed. It is possible to suppress the occurrence of defects due to an increase in the surface roughness of the electroformed product due to trapped air bubbles.
The reason why the above effects are exhibited is presumed as follows, but is not limited thereto.
According to the method of manufacturing a master for electroforming of the present disclosure, it is possible to manufacture a master for electroforming by dry-etching the substrate and exposing it to the atmosphere without using an acid such as hydrofluoric acid. Therefore, the oxide film surface tends to have excellent hydrophilicity. Since the oxide film has excellent hydrophilicity, it is possible to suppress entrainment of air bubbles between the oxide film and the electroformed article when forming an electroformed article on the oxide film. It is possible to suppress the increase in the surface roughness of the casting and the occurrence of defects.

The method of dry etching the surface of the substrate is not particularly limited, and can be performed by using a conventionally known etching gas.
By dry-etching the base material, the oxide film already formed on the base material surface can be removed, and by exposure to the atmosphere, an oxide film having a thickness of 18 Å or less is formed on the base material surface. can be done.
Dry etching preferably uses one or more gases selected from the group consisting of rare gases, fluorine-based gases, and chlorine-based gases. By using the above gas, it is possible to suppress the oxide film from remaining on the substrate surface.
He gas, Ar gas, or the like can be used as the rare gas.
SF ₆ gas, CF ₄ gas, CHF ₃ gas, C ₂ F ₆ gas, C ₄ F ₈ gas, etc. can be used as the fluorine-based gas.
As the chlorine-based gas, _Cl2 gas _{, CHCl3} gas, _CH2Cl2 gas, _CCl4 gas, _BCl3 gas, etc. can be used.
Among the above, SF ₆ gas or Ar gas is preferable from the viewpoint that the surface of the electroformed product can be mirror-finished.

From the viewpoint of improving the adhesion of the electroforming master to the electroformed product, the time of exposure to the atmosphere is 1 atm, 23 ° C. ± 2 ° C., and 50% RH ± 5% RH. , preferably 24 hours or less, more preferably 19 hours or less, even more preferably 5 hours or less, particularly preferably 1 hour or less, and may be 10 minutes or less.
The lower limit of exposure time to the air is not particularly limited, and can be, for example, 1 minute or more.

The step of forming an oxide film includes, after dry etching and before exposure to the atmosphere, a group consisting of immersion in sulfuric acid-hydrogen peroxide mixture, UV (ultraviolet) ozone treatment, and oxygen gas plasma treatment. It may include applying one or more more selected treatments.
The step of forming the oxide film can improve the hydrophilicity of the surface of the oxide film by including the treatment described above, and the electroformed product can be manufactured using the master for electroforming manufactured by the manufacturing method of the present disclosure. During production, it is possible to suppress the entrainment of air bubbles between the oxide film and the electroformed product, and suppress the occurrence of defects due to the increase in the surface roughness of the electroformed product due to the trapped air bubbles. be able to.

A commercially available base material having a pattern on the surface thereof, which is used for manufacturing the master disc for electroforming, may be used, or a base material manufactured by a conventionally known method may be used.
An embodiment of a method for manufacturing a substrate having a pattern on its surface will be described below with reference to FIGS. 2(A) to 2(E).

First, a substrate 20 containing a silicon-based semiconductor is prepared, and one surface of the substrate 20 is thermally oxidized to form an inorganic insulating film 21, which is a silicon-based oxide film (FIG. 2A).

A resist is applied to the surface of the inorganic insulating film 21 to form a resist film 22 (FIG. 2B).
The resist is not particularly limited, and ultraviolet curable resins and the like conventionally used in photolithography can be used.

The resist film 22 is exposed in a pattern (FIG. 2(C)).
The patterned exposure of the resist film 22 can be performed by using a conventionally known patterning mask 23, as shown in FIG. 2(C).

After the exposure, a conventionally known developer is used to wash and remove the exposed portion of the resist film to form a resist mask 24 (FIG. 2(D)).

After the formation of the resist mask 24, dry etching is performed to remove the inorganic insulating film 21 formed in the portions where the resist mask 24 is not formed. can be obtained (FIG. 2(E)).

(Manufacturing method of electroformed product)
The method for producing an electroformed article of the present disclosure comprises the steps of forming an electroformed article on the surface of the electroforming master plate on which the oxide film is formed in an electroforming liquid, using the above-described electroforming master plate as a cathode; It includes the step of peeling off from the casting master.

According to the method for manufacturing an electroformed article of the present disclosure, it is possible to suppress the peeling of the growing electroformed article from the master plate for electroforming.

The reason why the above effects are exhibited is presumed as follows, but is not limited thereto.
An electroforming master plate used in the method for producing an electroformed article of the present disclosure includes a substrate, and an oxide film having a thickness of 18 Å or less is formed on the surface of the substrate. By setting the thickness of the oxide film to 18 Å or less, the decrease in electrostatic attraction between the substrate and the electroformed object growing on the oxide film is suppressed. It is presumed that it has excellent adhesion to castings and suppresses peeling of electroformed products during growth.

[Step of forming an electroformed product]
An electroformed product can be formed by using the above-described electroforming master disk as a cathode in an electroforming solution and applying an electric current.
The electroforming liquid to be used is not particularly limited, and for example, a nickel sulfamate electroforming liquid can be used.
A material that can be used as the anode is not particularly limited, and for example, a nickel plate can be used.

The current density and energization time in the energization are not particularly limited, and are preferably adjusted appropriately according to the desired size of the electroformed article to be formed.
For example, the current density can be 5 A/dm ² to 10 A/dm ² and the energization time can be 10 minutes to 2 hours.

The electroformed product may be formed only on the surface of the oxide film, but as shown in FIG. may be formed as follows (so-called "overgrowth"). In FIG. 3, the substrate is designated 34 .

[Step of removing electroformed product]
The method for peeling the electroformed product from the master plate for electroforming is not particularly limited, and a conventionally known method can be used.

[Step of cleaning the master plate for electroforming]
The method of manufacturing an electroformed article according to the present disclosure can include a step of cleaning the electroforming master after the step of separating the electroformed article from the electroforming master.
In the electroformed product manufacturing method of the present disclosure, it is preferable to perform a cycle including the cleaning step, the electroformed product forming step, and the peeling step multiple times.

The method for cleaning the electroforming master is not particularly limited, and can be performed by a conventionally known method. For example, the electroforming master can be washed by using a cleaning liquid containing caroic acid. . Examples of the cleaning solution containing Caro's acid include SH303 manufactured by Kanto Kagaku Co., Ltd.

EXAMPLES Hereinafter, the above-described embodiment will be specifically described with reference to Examples, but the above-described embodiment is not limited to these Examples.

<Example 1>
A base material (725 μm thick) containing a silicon-based semiconductor was prepared, and one surface of the base material was thermally oxidized to form an inorganic insulating film having a thickness of 2 μm. The inorganic insulating film was a silicon oxide film containing silane dioxide.

A resist (MICROPOSIT ^™ S1818G manufactured by Rohm and Haas Electronic Materials Co., Ltd.) was applied to the surface of the inorganic insulating film by spin coating to form a resist film, and the resist film was exposed in a pattern. After the exposure, a developing solution was used to remove the exposed portion of the resist film by washing to form a resist mask on the inorganic insulating film.

After forming the resist mask, the inorganic insulating film formed on the portion of the substrate where the resist mask was not formed was removed by a dry etching method using a mixed gas of CHF ₃ and CF ₄ .
Next, the resist mask was peeled off, and a substrate having a pattern formed by an inorganic insulating film was produced.
The dry etching conditions are CHF ₃ gas flow rate of 24×10 ⁻⁴ m ³ /hr, CF ₄ gas flow rate of 6×10 ⁻⁴ m ³ /hr, pressure of 0.6 Pa, and inductively coupled plasma (ICP). ) 200 W, bias 30 W, lower cooling temperature 50 ° C., treatment time 80 minutes

The base material was allowed to stand in an environment of 23° C. and 50% RH for 168 hours.
After standing, the surface of the substrate on which the pattern is formed was dry-etched using _SF6 gas to remove an oxide film having a thickness of 25 Å formed on the surface of the substrate on which the pattern was formed. .
After removing the oxide film, the substrate was exposed to the atmosphere for 5 minutes to form an oxide film on the surface, thereby obtaining a master plate for electroforming.
The dry etching conditions were SF ₆ gas flow rate of 6×10 ⁻⁴ m ³ /hr, pressure of 0.6 Pa, inductively coupled plasma (ICP: Industry Coupled Plasma) of 500 W, bias of 15 W, and processing time of 1 minute.
The atmospheric conditions for exposure were 1 atm, 23° C., 50% RH, and 5 minutes of exposure time.

The thickness of the oxide film formed on the surface of the master plate for electroforming was measured by an ellipsometer (automatic ellipsometer DVA-36L manufactured by Mizojiri Kogaku Kogyo Co., Ltd.) in the atmosphere at 23° C. and 50% RH, and it was 8 Å. rice field.

<Examples 2 to 5>
A master disc for electroforming was manufactured in the same manner as in Example 1, except that the exposure time to the air was changed to the time shown in Table 1. The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Example 6>
A master for electroforming was manufactured in the same manner as in Example 1, except that the surface of the substrate on which the pattern was formed was dry-etched with _SF6 gas and _CHF3 gas.
The dry etching conditions are SF ₆ gas flow rate 6×10 ⁻⁴ m ³ /hr, CHF ₃ gas flow rate 24×10 ⁻⁴ m ³ /hr, pressure 0.6 Pa, inductively coupled plasma 500 W, bias 15 W,
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Example 7>
A master for electroforming was manufactured in the same manner as in Example 1, except that the surface of the substrate on which the pattern was formed was dry-etched with Ar gas.
The dry etching conditions were Ar gas flow rate of 6×10 ⁻³ m ³ /hr, pressure of 3 Pa, dielectric coupling plasma of 300 W, bias of 120 W, and processing time of 1 minute.
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Example 8>
After dry etching using _SF6 gas on the surface of the substrate on which the pattern is formed, an electroforming master was prepared in the same manner as in Example 1, except that oxygen gas plasma treatment was performed before exposure to the atmosphere. manufactured.
The oxygen gas plasma processing conditions were O ₂ gas flow rate of 18×10 ⁻³ m ³ /hr, pressure of 10 Pa, dielectric coupling plasma of 800 W, bias of 100 W, and processing time of 1 minute.
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Example 9>
For electroforming, in the same manner as in Example 1, except that after dry etching using _SF6 gas on the surface on which the pattern of the substrate is formed, immersion in sulfuric acid hydrogen peroxide mixture was performed before exposure to the atmosphere. Manufactured the original.
The immersion in the sulfuric acid/hydrogen peroxide mixture was carried out using SH303 manufactured by Kanto Kagaku Co., Ltd. under the conditions of immersion time of 20 minutes and water washing time of 5 minutes.
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Example 10>
After dry etching using _SF6 gas on the patterned surface of the substrate, except that UV ozone treatment was performed before exposure to the atmosphere, the same procedure as in Example 1 was performed to produce a master for electroforming. bottom.
The UV ozone treatment was carried out by irradiating UV rays from a low-pressure mercury lamp (wavelength: 185 nm) for 5 minutes using a UV ozone cleaning device manufactured by Sen Special Light Source Co., Ltd.
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Comparative Example 1>
A master for electroforming was obtained in the same manner as in Example 1, except that the surface of the substrate on which the pattern was formed was not dry-etched using _SF6 gas and was not exposed to the atmosphere. Since dry etching and exposure to the atmosphere were not performed, Table 1 shows the surface treatment method and exposure time to the atmosphere as "-".
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Comparative Example 2>
A master disc for electroforming was obtained in the same manner as in Example 1, except that the exposure time to the atmosphere was changed to 116 hours.
The thickness of the oxide film was measured in the same manner as in Example 1 and is shown in Table 1.

<Comparative Example 3>
A master for electroforming was obtained in the same manner as in Example 1, except that exposure to the air was not performed. In Table 1, the time of exposure to the atmosphere is indicated as "-" because no exposure to the atmosphere was performed.
Since the formation of an oxide film was not confirmed on the electroforming master of Comparative Example 3, the thickness of the oxide film is indicated as "-" in Table 1.

<<Contact angle with water>>
The water contact angles of the oxide films provided on the electroforming masters produced in the above examples and comparative examples were measured and shown in Table 1.
The contact angle with water was measured in an environment of 23° C. using DMo-701 manufactured by Kyowa Interface Science Co., Ltd. by the air-drop method. Note that the water droplet volume used for the measurement was 1 μL.

<<Specification of terminal group>>
Terminal groups on the surface of the oxide film provided in the electroforming masters produced in the above examples and comparative examples were specified as follows.
First, an electroforming master was immersed in trifluoroacetic anhydride. Then, by detecting the presence of trifluoromethyl groups by XPS, the terminal groups on the surface of the oxide film were identified. All were hydroxyl groups.
In XPS, the X-ray source is monochromatic Al Kα rays, the X-ray spot diameter is 100 μm, and the photoelectron escape angle is 90° (inclination of the detector with respect to the oxide film surface).
For XPS, an X-ray photoelectron spectrometer (Axis-Ultra, manufactured by Shimadzu Corporation) was used.
Since formation of an oxide film was not confirmed in the master disc for electroforming of Comparative Example 3, in Table 1, the terminal group is indicated as "-".

<<Evaluation of Adhesion between Electroforming Master and Electroformed Product>>
Using the electroforming master produced in the above Examples and Comparative Examples as a cathode, the electroforming master was immersed in a nickel electroforming solution and energized at a current density of 6.2 A/dm ² for 50 minutes to oxidize the electroforming master. An electroformed product having a thickness of 50 μm was manufactured by electroforming nickel on the film forming surface. A nickel plate was used as the anode.
An electroformed product having a thickness of 10 μm was manufactured in the same manner as described above except that the current density was changed to 6.2 A/dm ² and the current application time was changed to 10 minutes.
The manufactured electroformed product was visually observed and evaluated based on the following evaluation criteria. Table 1 shows the evaluation results.
In Comparative Example 3, neither the 50 μm-thick electroformed product nor the 10 μm-thick electroformed product was observed to separate from the electroforming master disc. , Cohesive failure of the electroformed article or master plate for electroforming occurred.
(Evaluation criteria)
A: No peeling from the electroforming master disc was observed in either the 50 μm-thick electroformed product or the 10 μm-thick electroformed product.
B: Peeling of the 10 μm-thick electroformed material from the electroforming master was not confirmed, but peeling of the 50 μm-thick electroformed material from the electroforming master was confirmed.
C: Separation from the electroforming master was confirmed in both the 50 μm-thick electroformed product and the 10 μm-thick electroformed product.

<<Surface roughness Ra>>
The electroformed product produced in the evaluation of the adhesion between the electroforming master and the electroformed product is peeled off from the electroforming master, and the surface roughness Ra of the peeled surface of the electroformed product is measured with a non-contact 3D surface roughness / shape measuring machine ( It was measured using New View 7300 manufactured by ZYGO, and the measurement results are shown in Table 1.
In producing the electroformed article, the surface roughness Ra of the electroformed article was not measured for Comparative Examples 1 and 2 in which separation of the electroformed article from the electroforming master was confirmed. is described as "-".
The above-described examples and comparative examples having an adhesiveness evaluation of A are electroformed articles having a thickness of 50 μm, and the examples having an adhesiveness evaluation of B are electroformed articles having a thickness of 10 μm. I made a measurement.

As is clear from the results shown in Table 1, the electroforming master discs of the examples, which include an oxide film having a thickness of 18 Å or less, have excellent adhesion to the electroformed product, and are effective in preventing peeling of the electroformed product during growth. can be effectively suppressed.
The electroforming master disc of the comparative example, which has an oxide film having a thickness of 18 Å or more, has a lower adhesion to the electroformed object than the electroforming master disc of the example, and peeling of the growing electroformed object occurs. I understand.

<<Evaluation of suitability for repeated use>>
Here, the suitability for repeated use of the electroforming master discs of Examples was evaluated by the following method.
First, from the electroforming masters of Examples 1 to 10, the electroformed products produced in the evaluation of the adhesion between the electroforming master and the electroformed products were peeled off, and the electroforming masters were manufactured by Kanto Chemical Co., Ltd. Washed with SH303.
After washing, nickel was electroformed on the electroforming master by the method described above to produce an electroformed product.
Manufacture of the electroformed product, peeling of the electroformed product, and cleaning of the master plate for electroforming were defined as one cycle, and this cycle was repeated five times.
After peeling off the electroformed material, the pattern on the surface of the base material provided in the electroforming master of each example was visually observed. It could be confirmed.
In addition, when the electroformed product manufactured in each cycle was evaluated for the adhesion between the electroforming master and the electroformed product, the evaluation results in each example were the same. It was confirmed that the adhesiveness to the casting did not deteriorate.

10: master plate for electroforming, 11: oxide film, 12: base material, 13: pattern, 20: base material, 21: inorganic insulating film, 22: resist film, 23: patterning mask, 24: resist mask, 25: pattern , 26: substrate with pattern, 31: oxide film, 32: electroformed product, 33: pattern, 34: substrate

Claims (14)

A master plate for electroforming, comprising a substrate containing an n-type semiconductor and having a pattern on its surface, wherein an oxide film is formed on the surface, the oxide film having a thickness of 18 Å or less. 2. The master for electroforming according to claim 1, wherein said oxide film contains hydroxyl terminal groups. 3. The master disc for electroforming according to claim 1, wherein the contact angle of said oxide film with water at 23[deg.] C. is 40[deg.] or less. The master disc for electroforming according to any one of claims 1 to 3, wherein the n-type semiconductor is a silicon-based semiconductor. 5. The master disc for electroforming according to claim 1, wherein the pattern is formed of an inorganic insulating film. 6. The master plate for electroforming according to claim 5, wherein said inorganic insulating film is a silicon-based oxide film. 7. The master plate for electroforming according to claim 5, wherein the inorganic insulating film has a thickness of 0.1 [mu]m or more. The master plate for electroforming according to any one of claims 1 to 7, wherein the oxide film has a thickness of 2 Å or more. After subjecting the surface of a substrate containing an n-type semiconductor and having a pattern on the surface to dry etching, the substrate is exposed to the atmosphere to form an oxide film having a thickness of 18 Å or less, A method for manufacturing a master for electroforming. 10. The method of manufacturing a master for electroforming according to claim 9, wherein the exposure time is 19 hours or less under conditions of 1 atm, 23° C.±2° C., and humidity of 50% RH±5% RH. 11. The method of manufacturing an electroforming master disk according to claim 9, wherein the dry etching is performed using one or more gases selected from the group consisting of rare gases, fluorine-based gases, and chlorine-based gases. wherein the step of forming the oxide film is after dry etching and before exposure to the atmosphere, from the group consisting of immersion in sulfuric acid/hydrogen peroxide mixture, UV ozone treatment, and oxygen gas plasma treatment; 12. The method of manufacturing a master for electroforming according to any one of claims 9 to 11, comprising applying one or more selected treatments. A step of forming an electroformed article on the surface of the electroforming master on which the oxide film is formed in an electroforming liquid, using the electroforming master according to any one of claims 1 to 8 as a cathode. and a method for producing an electroformed article, comprising a step of separating the electroformed article from the master plate for electroforming. including a step of cleaning the electroforming master after the step of peeling,
14. The method for producing an electroformed article according to claim 13, wherein a cycle including the cleaning step, the electroformed article forming step, and the peeling step is performed multiple times.

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