TW201534956A - Component with reflection preventing function and manufacturing method thereof - Google Patents

Abstract

Disclosed is to provide a component with an antireflection function and a manufacturing method thereof capable of obtaining an antireflection structure of a uniform micros asperities by uniformly forming a thin aluminum oxide film on a substrate. A component (10) with an antireflection function includes: a substrate (11) and an antireflection film (13) formed on a surface of the substrate (11). The antireflection film (13) is formed with a micro asperity structure by subjecting an aluminum oxide film, which is formed by atomic layer deposition, to a hydrothermal treatment using either high-temperature hot water or water vapor.

Description

Member with reflection preventing function and manufacturing method thereof

The present invention relates to a member having a reflection preventing function and a method of manufacturing the same.

A reflection preventing structure is required for a lens, a flat panel display (FPD) substrate, a semiconductor substrate, or the like. In the anti-reflection structure, a so-called moth-eye structure in which the refractive index does not change rapidly is formed by forming a fine concavo-convex structure on the surface of the substrate. In the method of forming an anti-reflection structure by forming a fine concavo-convex structure on such a surface, a hydrothermal treatment of immersing hot water having a boiling point or lower after forming an aluminum oxide film or the like on a substrate is proposed (for example, Patent Document 1) ,2).

In the method of forming an aluminum oxide film at this time, Patent Document 1 discloses a sol-gel method, and Patent Document 2 discloses a chemical vapor deposition method (CVD method) or a physical vapor deposition method (PVD method).

[prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-72046

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-198330

However, as an optical member, in addition to the reflection preventing function, a high light transmission function is required, that is, a function of not impairing the transmittance of transmitted light, and the thicker the thickness of the formed aluminum oxide film, the higher the transmittance is due to light. Since it absorbs and falls, it is necessary to make an aluminum oxide film into a film (100 nm or less) as much as possible. However, in the case of a large substrate such as an FPD substrate, it is difficult to uniformly form a film of 100 nm or less in the sol-gel method, the CVD method, or the PVD method.

In addition, when a reflection preventing structure as described in Patent Documents 1 and 2 is formed on a substrate having a large refractive index such as a ruthenium wafer, the refractive index of alumina is 1.6, and the refractive index of yttrium is 3.8. These refractive index differences are large, and it is difficult to say that there is a sufficient reflection preventing effect.

The present invention has been conceived in view of the above-mentioned circumstances, and has been provided to provide a member having an antireflection function capable of uniformly forming a thin aluminum oxide film on a substrate to obtain a uniform fine concavo-convex shape, and a method for producing the same. .

Further, it is an object to provide a member having an antireflection function and a method for producing the same, which can provide a sufficient reflection preventing function even for a substrate having a large refractive index.

In order to solve the above problems, a first aspect of the present invention provides a member having a reflection preventing function, comprising: a substrate; and a member having an antireflection function of an antireflection film formed on a surface of the substrate, wherein The anti-reflection film is hydrothermally treated with a high-temperature hot water or water vapor to form an aluminum oxide film formed by an atomic layer deposition method to form a fine concavo-convex structure.

In the above first aspect, the member having the reflection preventing function can be used as an optical member or a device for forming a substrate or a substrate for a flat display. Further, the above aluminum oxide film can be formed by alternately supplying trimethylaluminum and an oxidizing agent.

According to a second aspect of the present invention, a method for producing a member having a reflection preventing function, comprising: a process of forming an aluminum oxide film by an atomic layer deposition method on a surface of a substrate; and a hot water by a high temperature Or the water vapor is subjected to a hydrothermal treatment on the above-mentioned aluminum oxide film to form a fine concavo-convex structure, and the anti-reflection film is formed.

In the above second aspect, the aluminum oxide film can be formed by alternately supplying trimethylaluminum and an oxidizing agent.

According to a third aspect of the present invention, there is provided a member having a reflection preventing function, wherein a member having an anti-reflection function formed by forming a fine uneven portion having a reflection preventing function on a surface of a substrate is characterized in that: In the uneven portion, an aluminum oxide film is formed on the surface of the base material, and then the aluminum oxide film is hydrothermally treated to form fine irregular aluminum oxide, and then the fine uneven aluminum oxide is used as an etching mask. Dry etching on the surface of the material, and removing the above-mentioned fine irregularities Formed by alumina.

In the above third aspect, it is preferable that the aluminum oxide film used in forming the fine uneven portion is formed by an atomic layer deposition method. Further, the member having the reflection preventing function can be used as an optical member or a device for forming a substrate or a substrate for a flat display.

According to a fourth aspect of the present invention, there is provided a method for producing a member having an antireflection function, comprising: forming an aluminum oxide film on a surface of a substrate; and the above alumina by hot water or steam at a high temperature a film is subjected to hydrothermal treatment to form fine irregular aluminum oxide; and the fine irregular aluminum oxide is used as an etching mask to dry-etch the surface of the substrate to form fine irregularities on the surface of the substrate. Further, the above-mentioned fine irregular aluminum oxide is removed, and an anti-reflection structure is formed.

In the above fourth aspect, the process of forming the above-mentioned aluminum oxide film is preferably performed by an atomic layer deposition method.

According to a fifth aspect of the present invention, there is provided a member having an antireflection function, wherein a member having an antireflection function is formed on a surface of a substrate and having a fine uneven portion having a reflection preventing function, wherein the fine concavo-convex portion By forming an etchable film having a refractive index in the vicinity of the refractive index of the substrate on the surface of the substrate, which is more easily etched than the substrate, an aluminum oxide film is formed on the surface of the etchable film, followed by oxidation The aluminum film is hydrothermally treated to form fine asperity-like alumina, and then the fine irregular aluminum oxide is used as an etching mask to dry-etch the surface of the easily etchable film, and the fine uneven aluminum oxide is removed. to make.

According to a sixth aspect of the present invention, there is provided a method for producing a member having a reflection preventing function, comprising: forming a refractive index in the vicinity of a refractive index of a substrate on a surface of a substrate, and being more easily etched than a substrate; Engineering of an easily etchable film; engineering of forming an aluminum oxide film on the surface of the above-mentioned easily etchable film; engineering of forming a fine irregular aluminum oxide by hydrothermal treatment of the above-mentioned aluminum oxide film by hot water or steam at a high temperature And the surface of the easy-etchable film is dry-etched by using the fine concavo-convex alumina as an etching mask, and fine irregularities are formed on the surface of the easy-etchable film, and the fine uneven aluminum oxide is removed to form The project of reflection prevention construction.

In the fifth and sixth aspects, it is preferable that the aluminum oxide film used in forming the fine uneven portion is formed by an atomic layer deposition method. Further, the fifth and sixth aspects are suitable when the substrate is a glass substrate, a transparent conductive film, or a color filter-like opaque substrate.

According to the first and second aspects of the present invention, the base material is formed into an aluminum oxide film on the surface thereof, and then subjected to hydrothermal treatment to form a fine concavo-convex structure, whereby the anti-reflection film is formed by the atomic layer. Since the aluminum oxide film is formed by the deposition method, even when it is a large substrate, a thin aluminum oxide film can be uniformly formed on the entire substrate, and the high light transmission function is not impaired, and the entire surface of the substrate can be uniformly formed. An anti-reflection film constituting a fine uneven shape is formed in the ground.

According to the third and fourth aspects of the present invention, the fine concavo-convex alumina formed by hydrothermal treatment after forming an aluminum oxide film on the surface of the substrate is used as an etching mask, and the surface of the substrate is dried. By forming a fine uneven portion on the surface of the substrate by etching and removing the fine uneven aluminum oxide to form an antireflection structure, even if the substrate having a high refractive index does not cause reflection due to the difference in refractive index, sufficient Reflection prevention function.

According to the fifth and sixth aspects of the present invention, alumina is formed by forming an easily etchable film having a refractive index in the vicinity of the refractive index of the substrate on the surface of the substrate and being more easily etched than the substrate. The fine concavo-convex alumina formed by hydrothermal treatment is used as an etching mask, and the surface of the easily etchable film is dry-etched to form fine concavo-convex portions on the surface of the substrate, and the fine concavo-convex alumina is removed to form an anti-reflection structure. Therefore, even if the substrate has a high refractive index and is difficult to etch, reflection due to the difference in refractive index does not occur, and a sufficient reflection preventing function can be obtained.

10, 20‧‧‧ Components with reflection prevention

11, 21‧‧‧ substrate

13‧‧‧Anti-reflection film

14‧‧‧Al ₂ O ₃ film

15‧‧‧ convex

16‧‧‧ recess

22‧‧‧Micro-concave parts

23‧‧‧Al ₂ O ₃ film

24‧‧‧Micro-concave Al ₂ O ₃

Fig. 1 is a cross-sectional view showing a member having an antireflection function according to a first embodiment of the present invention.

FIG. 2 is a view for explaining a method of forming an anti-reflection film of a member having an antireflection function according to the first embodiment of the present invention.

Fig. 3 is a cross-sectional view showing a member having an antireflection function according to a second embodiment of the present invention.

Fig. 4 is a view for explaining a method of forming a fine uneven portion of a member having an antireflection function according to a second embodiment of the present invention.

FIG. 5 is a view for explaining a change in refractive index of a surface portion when an Al ₂ O ₃ film is formed on the surface of a substrate and a fine uneven film formed by hydrothermal treatment is used as an antireflection film.

Fig. 6 is a view for explaining a change in refractive index of a surface portion when a fine uneven portion is formed on a surface of a substrate in a second embodiment of the present invention.

Fig. 7 is a cross-sectional view showing a member having a reflection preventing function according to a third embodiment of the present invention.

Fig. 8 is a view for explaining a method of forming a fine uneven portion of a member having an antireflection function according to a third embodiment of the present invention.

FIG. 9 is a view showing a surface in which an easily etchable film is formed on the surface of the substrate, and a film having a fine unevenness formed by hydrothermal treatment is formed as an antireflection film after forming an Al ₂ O ₃ film on the surface thereof. A graphical representation of a partial change in refractive index.

FIG. 10 is a view for explaining a change in refractive index of a surface portion when a fine uneven portion is formed on the surface of the etchable film in the third embodiment of the present invention.

The embodiments of the present invention will be described below with reference to the attached drawings.

[First embodiment]

Fig. 1 is a cross-sectional view showing a member having an antireflection function according to a first embodiment of the present invention.

The member 10 having the reflection preventing function according to the present embodiment has the substrate 11 and an anti-reflection film 13 which is formed on the surface of the substrate 11 and has a moth-eye structure having a fine uneven shape. The member 10 may be used as an optical member such as a lens, and may be used as a substrate for device formation or FPD.

The material of the substrate 11 is not particularly limited, and may be any of glass, semiconductor, ceramic, plastic, and metal. When used as a substrate for a device, it is used as a substrate for FPD or The use of glass when the lens is used is a typical example.

The anti-reflection film 13 is formed into an aluminum oxide (Al ₂ O ₃ ) film by an atomic layer deposition method (ALD method), and then subjected to hydrothermal treatment to form an Al ₂ O ₃ film into an uneven shape.

Hereinafter, a method of forming the anti-reflection film 13 will be specifically described with reference to FIG. 2 .

As shown in Fig. 2(a), the Al ₂ O ₃ film 14 is initially formed on the surface of the substrate 11 by an ALD method.

When the Al ₂ O ₃ film 14 is formed by the ALD method, the operation of forming the thin unit film composed of Al ₂ O ₃ by sequentially supplying the Al-containing gas and the oxidant in multiple steps is repeated. The Al gas and the oxidizing agent make the Al ₂ O ₃ film having a specific film thickness. Specifically, the substrate is housed in the processing container, and the substrate is heated to a specific temperature, and the inside of the processing container is evacuated to a specific degree of vacuum. In the state, "the supply of the Al-containing gas is included in the processing container. The rinsing→the supply of the oxidizing agent→the rinsing in the processing container was repeated as a cycle for one cycle of unit film formation.

The Al-containing gas is not particularly limited, and may be a general user. For example, trimethylaluminum (TMA): Al(CH ₃ ) _{3 is} exemplified. As the oxidizing agent, for example, H ₂ O, O ₃ , O ₂ plasma can be used.

In this case, the thickness of the Al ₂ O ₃ film 14 is preferably a thickness of a reflection preventing structure which is expected to be obtained by hydrothermal treatment. From this point of view, it is preferably 100 nm or less, and more preferably 10 to 50 nm.

Next, as shown in FIG. 2(b), the Al ₂ O ₃ film 14 is hydrothermally treated, and fine irregularities having the fine convex portions 15 and the concave portions 16 are formed in the Al ₂ O ₃ film 14. Thereby, the anti-reflection film 13 having a fine uneven shape is formed.

The hydrothermal treatment can be carried out by the methods disclosed in the above Patent Documents 1 and 2. Specifically, it can be carried out by a method of immersing in an aqueous solution of hot water or a high-temperature alkali, or a method of exposing it to water vapor. Thereby, irregularities deeper than the thickness of the original Al ₂ O ₃ film 14 are formed. At this time, it is preferable that all of the Al ₂ O ₃ film 14 does not react with hot water, and it is preferable that the lower layer side of the Al ₂ O ₃ film 14 remains as unreacted. In this case, the adhesion between the portion which is finely concavo-convex and the substrate 11 is lowered, and the adhesion is easily removed. However, since the unreacted Al ₂ O ₃ film remains, the adhesion can be suppressed from being lowered. The thickness of the unreacted Al ₂ O ₃ film is preferably from 1 to 25 nm. The aqueous solution of hot water or high-temperature alkali is preferably at a boiling temperature of 60 ° C or higher. The immersion time for this varies depending on the film thickness of the Al ₂ O ₃ film, but it is preferably from 1 second to 30 minutes, more preferably from 10 seconds to 10 minutes. The treatment time when exposed to water vapor is preferably from 1 minute to 24 hours.

The fine convex portion 15 and the concave portion 16 formed by such hydrothermal treatment are formed by a gap of, for example, about 100 nm, and may be a gap shorter than the wavelength of the irradiated light, and the shape of the fine unevenness is a needle shape or a spindle. Since the refractive index changes continuously in the depth direction, the reflection preventing function can be obtained.

The depth (the height of the convex portion) formed in the fine concavities and convexities of the anti-reflection film 13 is preferably 100 to 500 nm in order to obtain a good reflection preventing function.

The anti-reflection film 13 has excellent antireflection properties, and in particular, when it is used for a light-transmitting member, it is necessary to form a transmittance (light absorption) which does not ineffectively deteriorate, and the adhesion does not decrease. Therefore, the Al ₂ O ₃ film must satisfy the above conditions. In other words, in order to satisfy the transmittance, it is necessary to form a film in a range of 100 nm or less, more preferably 25 to 50 nm, and in order to improve the adhesion, it is necessary to leave the unreacted Al ₂ O ₃ film at 1 to 25 nm. However, in the case of a large-area substrate, it is necessary to form such a film uniformly in the plane (preferably ±5% or less), and further, since the unreacted Al ₂ O ₃ film is a film as a film of 1 to 25 nm. Since it is thick, in order to control this with high precision, the uniformity of the Al ₂ O ₃ film which becomes a base must still be extremely high. However, in the conventional CVD method and PVD method, such a thin film thickness cannot be uniformly formed.

In contrast, in the present embodiment, because ALD method ₂ O ₃ film 14 is formed Al, it is possible to form a uniform film thickness and Al ₂ O ₃ film 14. Further, since the step coverage of the ALD method is good, the Al ₂ O ₃ film 14 can be uniformly formed on the entire substrate 11 even when a structure is present on the substrate. In other words, in the ALD method, since the operation of forming the thin unit film is repeated a plurality of times, the substrate can be formed thinly and uniformly with high step coverage, and the entire surface of the substrate 11 can be thin and uniform. The anti-reflection film 13 having fine unevenness is formed to have good adhesion.

Further, since the coverage by the ALD method is so good, it is possible to form a film on the back surface or the side surface of the substrate which is not sufficiently formed by other methods, not only on the upper surface of the substrate.

[Second embodiment]

Fig. 3 is a cross-sectional view showing a member having an antireflection function according to a second embodiment of the present invention.

The member 20 having the reflection preventing function according to the present embodiment is formed with a fine uneven portion 22 having a moth-eye structure having an antireflection function on the surface of the substrate 21. The member 20 may be used as an optical member such as a lens, and may be used as a substrate for device formation or FPD.

The material of the substrate 21 is not particularly limited, and may be any of glass, semiconductor, ceramic, plastic, and metal, and may be used as a substrate for an apparatus for use as a substrate for an FPD or as a substrate for an FPD or The use of glass when the lens is used is a typical example.

The fine concavo-convex portion 22 can be formed by forming an Al ₂ O ₃ film on the surface of the substrate 21, followed by hydrothermal treatment to form the Al ₂ O ₃ film into fine concavo-convex Al ₂ O ₃ , and the fine concavo-convex Al ₂ O _{3 is} The surface of the substrate 21 is dry-etched for use as an etching mask, and fine irregularities are transferred, and fine concavo-convex Al ₂ O ₃ is removed.

Hereinafter, a method of forming the fine uneven portion 22 will be specifically described with reference to FIG. 4 .

As shown in FIG. 4(a), an Al ₂ O ₃ film 23 is initially formed on the surface of the substrate 21. In the present embodiment, unlike the first embodiment, the method of forming the Al ₂ O ₃ film 23 is not limited to the ALD method, and for example, even if a CVD method or a PVD method (sputtering method or vacuum evaporation method) is used, etc. Other methods are also available. However, from the viewpoint of forming the Al ₂ O ₃ film 23 thinly and uniformly on the surface of the substrate 21 with good coverage, it is preferable to use the ALD method as in the first embodiment.

At this time, the film thickness of the Al ₂ O ₃ film 23 can be formed into fine irregularities which are etching masks by the subsequent hydrothermal treatment, and the thickness of the desired fine uneven portion 22 can be preferably formed. From this point of view, the film thickness of the Al ₂ O ₃ film 23 is preferably 3 to 50 nm.

Next, as shown in FIG. 4(b), the Al ₂ O ₃ film 23 is subjected to a hydrothermal treatment to form fine concavo-convex Al ₂ O ₃ 24 . The hydrothermal treatment conditions at this time can be made the same as in the first embodiment. The fine concavo-convex Al ₂ O ₃ 24 is formed into a needle shape or a spindle shape.

The depth (the height of the convex portion) of the unevenness of the fine concavo-convex Al ₂ O ₃ 24 can be appropriately set depending on the depth of the fine uneven portion 22 to be obtained, etc., but preferably 10 to 300 nm.

Next, as shown in FIG. 4(c), the fine concavo-convex Al ₂ O ₃ 24 is used as an etching mask to start dry etching of the surface of the substrate 21. Then, as shown in FIG. 4(d), the fine concavo-convex Al ₂ O ₃ 24 is also etched together to form the fine uneven portion 22 having a desired depth. Even if the depth of the fine uneven portion 22 is different, the fine uneven O ₂ O ₃ 24 may be etched.

In the case of dry etching, a general plasma etching can be used. In the case of the etching gas, it is preferable to etch both the substrate 21 and the fine concavo-convex Al ₂ O ₃ 24, and it is preferable to appropriately select the substrate 21 depending on the type of the substrate 21. For example, when the substrate 21 is ruthenium, BCl ₃ and Cl _{2 are} exemplified, and when the substrate 21 is glass, BCl ₃ , CF ₄ , and O _{2 are} exemplified.

The depth of the fine uneven portion 22 (the height of the convex portion) can be determined by etching time, etching gas (type, flow rate), plasma condition (pressure, RF power), processing temperature, or the like, or fine unevenness belonging to the etching mask. The Al ₂ O ₃ 24 is adjusted in height. The depth of the fine uneven portion 22 (the height of the convex portion) may be appropriately set in accordance with the reflection preventing function to be obtained, and is preferably 100 to 1000 nm.

In the case where the Al ₂ O ₃ film is formed on the surface of the substrate and the fine concavo-convex film formed by hydrothermal treatment is used as the antireflection film, the substrate is as described in the above-mentioned Patent Documents 1 and 2. When a material having a large refractive index is formed, the difference in refractive index between the antireflection film made of Al ₂ O ₃ and the substrate becomes large, and reflection occurs at the interface.

Specifically, as shown in FIG. 5, when an anti-reflection film having a fine uneven shape made of Al ₂ O ₃ is formed on the surface of the germanium wafer, the refractive index n is from the air before reaching the substrate. =1 continuous change to n=1.6 of Al ₂ O ₃ , so that reflection can be prevented, but since the crucible constituting the substrate is n=3.8, the refractive index difference is large, and reflection at the interface between the anti-reflection film and the substrate is prevented. The effect is not sufficient. In order to solve the problem caused by the difference in refractive index, Patent Document 2 discloses that an optical adjustment film having a refractive index in the middle of the refractive index is formed between the substrate and the anti-reflection film, but the optical adjustment film is formed. It is difficult to eliminate the difference in refractive index between the optical adjustment film and the anti-reflection film or the substrate.

On the other hand, in the present embodiment, the substrate is subjected to dry etching by using the fine concavo-convex Al ₂ O ₃ formed by hydrothermal treatment as an etching mask, as shown in FIG. Since the substrate is transferred to the fine concavo-convex pattern, as shown in FIG. 6, it is possible to continuously change from the refractive index n=1 of air to the refractive index of the substrate, for example, the refractive index n of 矽. Therefore, even if the substrate has a high refractive index, reflection due to the difference in refractive index does not occur, and a sufficient antireflection effect can be obtained.

In addition, in the conventional method of forming a fine uneven portion on a substrate, there has been a method of using microbeads or using an electron beam, but it takes a lot of time to form fine concavities and convexities on a large substrate. . On the other hand, in the present embodiment, when the Al ₂ O ₃ film is formed on the substrate, hydrothermal treatment is performed to form fine concavo-convex Al ₂ O ₃ , and this can be dry-etched as an etching mask. Therefore, even if the substrate is large, the fine uneven portion can be formed all at once, and it can be formed in a short time.

[Third embodiment]

Fig. 7 is a cross-sectional view showing a member having a reflection preventing function according to a third embodiment of the present invention.

The structure with reflection prevention function related to this embodiment The member 30 is formed on the surface of the substrate 31 so as to have a refractive index in the vicinity of the refractive index of the substrate 31 (preferably having a refractive index difference of 0.1 or less), and the etchable film 32 which is easier to etch than the substrate 31, and The surface of the easily etchable film 32 is formed by forming a fine uneven portion 33 having a moth-eye structure having a reflection preventing function.

Such a structure is effective, for example, when the base material 31 is a material that is difficult to etch, such as a glass substrate, a transparent conductive film, a color filter, or the like, and it is difficult to directly form fine uneven portions.

That is, as in the second embodiment, when the base material and the Al ₂ O ₃ film have a large refractive index difference, the fine concavo-convex Al ₂ O ₃ formed by hydrothermal treatment is used as an etching mask. The cover is dry-etched to form a fine concavo-convex pattern for effective use, but it is difficult to apply when the substrate is a non-etchable material.

Therefore, in the present embodiment, the etchable film 32 composed of a material which is easily etched by the refractive index close to the substrate 31 is formed on the substrate 31, and the etchable film 32 is applied by The fine concavo-convex Al ₂ O ₃ formed by the hydrothermal treatment is etched as an etching mask, and a fine uneven portion 33 having a moth-eye structure having an antireflection function is formed on the surface of the etchable film 32.

Specifically, as shown in FIG. 8, a member 30 having a reflection preventing function is formed. That is, as shown in Fig. 8(a), the easily etchable film 32 is initially formed on the opatable substrate 31 by a suitable film formation method, and then, as shown in Fig. 8(b), the etchability is easy. An Al ₂ O ₃ film 34 is formed on the surface of the film 32. The method of forming the Al ₂ O ₃ film 34 at this time is the same as that of the Al ₂ O ₃ film 23 of the second embodiment, and is not limited to the ALD method, even if, for example, a CVD method or a PVD method (sputtering method or vacuum evaporation) is used. Other methods such as the method may be used, and it is preferable to use the ALD method. Further, the film thickness of the Al ₂ O ₃ film 34 is also the same as that of the Al ₂ O ₃ film 23 of the second embodiment. Next, as shown in FIG. 8(c), the Al ₂ O ₃ film 34 is subjected to a hydrothermal treatment to form fine concavo-convex Al ₂ O ₃ 35. In this case, the hydrothermal treatment conditions can be the same as in the first embodiment, and the fine concavo-convex Al ₂ O ₃ 35 is formed into a needle shape or a spindle shape. Next, as shown in FIG. 8(d), the fine concavo-convex Al ₂ O ₃ 35 is used as an etching mask to start dry etching of the surface of the easily etchable film 32. Then, as shown in FIG. 8(e), the easily etchable film 32 and the fine uneven Al ₂ O ₃ 35 are etched to form a fine uneven portion 33 having a desired depth.

The depth of the fine uneven portion 33 is preferably 100 to 1000 nm. In addition, it is not preferable to etch all of the easily etchable film 32 so as not to etch the lower layer side of the etchable film 32. This is because the adhesion between the fine uneven portion 33 and the substrate 31 is ensured.

In the present embodiment, since the etchable film 32 is required to be formed in the middle, it is more labor-intensive than the second embodiment. However, by appropriately selecting the material of the etchable film 32 in response to the substrate 31, the substrate can be made. The difference in refractive index between the material 31 and the etchable film 32 is almost eliminated, and as in the second embodiment, reflection due to the difference in refractive index does not occur, and a sufficient reflection preventing effect can be obtained.

Specifically, as shown in FIG. 9 , when a fine uneven portion composed of Al ₂ O ₃ (refractive index n=1.6) is present on the surface of the substrate having a large refractive index (refractive index n=A), The antireflection effect between Al ₂ O ₃ and the substrate is not sufficient, but an etchability having a refractive index close to the substrate (refractive index n = A) is provided between the substrate and Al ₂ O ₃ The film (refractive index n = A ± α), dry etching the easily etchable film by using the fine concavo-convex Al ₂ O ₃ formed by hydrothermal treatment as an etching mask, as shown in FIG. Since the fine concavo-convex pattern is transferred to the easily etchable film, and fine concavo-convex portions composed of a material having a refractive index close to each other are formed on the substrate, the refractive index of the substrate can be changed almost continuously from the refractive index of the air.

[Others apply]

Further, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above-described embodiment, the light-emitting portion such as a lens, a semiconductor substrate, or an FPD is applied to the present invention, but it can also be applied to a light-receiving portion such as a CMOS sensor or a solar cell. In the present embodiment, the material of the substrate, the hydrothermal treatment conditions, the depth of the fine concavities and convexities formed by the hydrothermal treatment, the conditions for dry etching the substrate, and the like are exemplified by a few examples. It is to be understood that various modifications may be made without departing from the spirit and scope of the invention.

10‧‧‧Members with reflection prevention

11‧‧‧Substrate

13‧‧‧Anti-reflection film

Claims (16)

A member having a reflection preventing function is provided with a substrate and a member having an antireflection function of an antireflection film formed on a surface of the substrate, wherein the antireflection film is heated by a high temperature The aluminum oxide film formed by the atomic layer deposition method is hydrothermally treated with water or steam to form a fine concavo-convex structure. A member having a reflection preventing function as claimed in claim 1, wherein the member is used as an optical member or a device for forming a substrate or a flat display. The member having the antireflection function according to claim 1 or 2, wherein the aluminum oxide film is formed by alternately supplying trimethylaluminum and an oxidizing agent. A manufacturing method of a member having a reflection preventing function, comprising: forming an aluminum oxide film by atomic layer deposition on a surface of a substrate; and applying the aluminum oxide film by hot water or steam at a high temperature The micro-concave structure is formed by hydrothermal treatment to form an anti-reflection film. The method for producing a member having an antireflection function according to claim 4, wherein the aluminum oxide film is formed by alternately supplying trimethylaluminum and an oxidizing agent. to make. A member having a reflection preventing function is a member having a reflection preventing function formed by forming a fine uneven portion having a reflection preventing function on a surface of a substrate, wherein the fine uneven portion is oxidized on the surface of the substrate. The aluminum film is then subjected to a hydrothermal treatment to form a fine concavo-convex alumina, and then the surface of the substrate is dry-etched by using the fine concavo-convex alumina as an etching mask, and the fine particles are removed. It is formed by embossed alumina. The member having the reflection preventing function according to claim 6, wherein the aluminum oxide film used in forming the fine uneven portion is formed by an atomic layer deposition method. A member having a reflection preventing function as claimed in claim 6 or 7, wherein the member is used as an optical member or a device for forming a substrate or a flat display. A manufacturing method of a member having a reflection preventing function, comprising: forming an aluminum oxide film on a surface of a substrate; and subjecting the aluminum oxide film to hydrothermal treatment by high-temperature hot water or steam to form fine unevenness And the surface of the base material is dry-etched by using the fine irregular aluminum oxide as an etching mask to form fine uneven portions on the surface of the substrate. Further, the fine irregular aluminum oxide is removed to form a structure for preventing the reflection. The method for producing a member having an antireflection function according to claim 9, wherein the step of forming the aluminum oxide film is performed by an atomic layer deposition method. A member having a reflection preventing function is a member having a reflection preventing function formed by forming a fine uneven portion having a reflection preventing function on a surface of a substrate, wherein the fine uneven portion is formed on the surface of the substrate Forming an etchable film having a refractive index in the vicinity of the refractive index of the substrate and being more easily etched than the substrate, forming an aluminum oxide film on the surface of the etchable film, and then hydrothermally treating the aluminum oxide film to form a fine The uneven alumina is formed by etching the surface of the easily etchable film by using the fine irregular aluminum oxide as an etching mask, and removing the fine uneven aluminum oxide. The member having the reflection preventing function according to claim 11, wherein the aluminum oxide film used in forming the fine uneven portion is formed by an atomic layer deposition method. A member having a reflection preventing function as claimed in claim 11 or 12, wherein the substrate is a glass substrate, a transparent conductive film or a color filter. A manufacturing method of a member having a reflection preventing function It is characterized in that an etchable film having a refractive index in the vicinity of the refractive index of the substrate is formed on the surface of the substrate and is more easily etched than the substrate; an aluminum oxide film is formed on the surface of the etchable film. Engineering for forming fine concavo-convex alumina by hydrothermal treatment of the above-mentioned aluminum oxide film by hot water or steam of high temperature; and the above-mentioned easily etchable film by using the above-mentioned fine concavo-convex alumina as an etching mask The surface is subjected to dry etching to form fine uneven portions on the surface of the above-mentioned etchable film, and the fine uneven aluminum oxide is removed to form an antireflection structure. The method for producing a member having an antireflection function according to claim 14, wherein the step of forming the aluminum oxide film is performed by an atomic layer deposition method. The method for producing a member having an antireflection function according to claim 14 or 15, wherein the substrate is a glass substrate, a transparent conductive film or a color filter.