JP2001343684A - Method for manufacturing metal mold for reticle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a metal mold for a reticle which is capable of molding the reticle free of video unevenness without the occurrence of such a defect as the collapse of a microlens molding surface by the adhesion of bubbles and impurities. SOLUTION: The method for manufacturing the metal mold for the reticle for manufacture of a diffusion plate used for the reticle, etc., of an optical system has a first process step for forming pyramidal regular concave-convex relief surfaces 4 and 5 on the surface of a mold substrate 1 and a second process step of smoothly rounding the pyramidal vertex parts and ridge line parts of the concave-convex relief surfaces 4 and 5 by depositing thin films 6 and 7 on the concave-convex relief surfaces 4 and 5 by vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a reticle mold for manufacturing a diffuser used for reticle of various optical systems.

[0002]

2. Description of the Related Art Conventionally, a technique disclosed in Japanese Patent Application Laid-Open No. 2-37334 is disclosed as to a method of manufacturing a reticle mold for manufacturing a diffusion plate used for a reticle or the like of a single-lens reflex camera. Have been. This technology processes each pyramid-shaped relief by processing a pyramid-shaped regular relief on the surface of a metal plate, and performing a satin-sulfated acidic copper electroplating containing an additive having no smoothing effect on the surface. After forming a spherical surface with a large number of regular irregularities, a sulfuric acid containing an additive having no smoothing action is further subjected to nickel electroplating, and a sulfuric acid containing an additive having a smoothing action is provided on the plating layer. A molding surface is formed by performing nickel electroplating.

[0003]

However, the above prior art has the following problems. That is, in the above-described conventional technology, electroplating is used to make the pyramid of the relief surface into a microlens molding surface, but in the plating step, hydrogen gas is generated on the relief surface to be electroplated, and the generated hydrogen gas is generated. Either they become bubbles and adhere to the relief surface, or impurities in the plating solution adhere to the relief surface. If the electroplating is performed with these components adhered, the portions to which bubbles and impurities adhere are not electroplated, and a defect such as crushing of the microlens molding surface occurs. The reticle formed by the reticle mold having this defect has a different diffusion characteristic only in a portion where the microlens molding surface has been crushed, so that image unevenness occurs. The size of the defect is 20 to 100 μm in diameter, and the smaller the size of the microlens, the greater the number of crushes and the greater the effect of the generated defect. However, bubbles and impurities in the plating solution that cause this defect are inevitable in performing electroplating.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the invention according to claims 1, 2, and 3 is that a defect such as collapse of a microlens molding surface due to attachment of bubbles or impurities occurs. An object of the present invention is to provide a method of manufacturing a reticle mold capable of forming a reticle without image unevenness without using the reticle.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1, 2 or 3 is directed to a reticle metal for manufacturing a diffusion plate used as a reticle of an optical system. In the method of manufacturing a mold, a first step of applying a regular pyramidal relief surface to the surface of a mold substrate, and depositing a thin film on the relief surface by vapor deposition, and forming a top portion and a ridge portion of the pyramid of the relief surface And a second step of smoothly rounding.

In the method for manufacturing a reticle mold according to the first, second or third aspect of the present invention, a regular pyramid-shaped relief surface is formed on the surface of the mold substrate in the first step, and the irregular surface is formed in the second step. By depositing a thin film on the uneven relief surface by vapor deposition and smoothly rounding the apex and ridge of the pyramid of the uneven relief surface, the occurrence of a defect such as collapse of the microlens molding surface due to attachment of bubbles or impurities is avoided.

In the method of manufacturing a reticle mold according to the second or third aspect of the present invention, in addition to the above-described operation, the second step is performed a plurality of times by changing the type of the thin film, thereby forming the pyramid of the uneven relief surface. The action of smoothly rounding the apex and the ridge is performed stepwise in the same device.

In the method of manufacturing a reticle mold according to the third aspect of the present invention, in addition to the above-described functions, the vapor deposition is performed by a PVD method or a PCV method.
By performing any one of the D method, the CVD method, and the sputtering method, the deposition of the thin film proceeds reliably.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The outline of the present invention will be described. When a metal is deposited by vapor deposition on the surface of the mold substrate on which the relief processing of the irregularities has been performed, the corners of the pyramid vertices and ridges are rounded by a smoothing effect to form a microlens molding surface, which is used as a reticle plate mold.

1 to 11 show an embodiment of the present invention. FIG. 1 is a plan view of a mold substrate, FIG. 2 is a side view and a plan view of a mold substrate subjected to a first relief processing, and FIG. 2, FIG. 4 is a plan view of a third relief-processed mold substrate, FIG. 5 is a perspective view of a relief surface of the relief-processed mold substrate, and FIG. 6 is a relief surface. 7, FIG. 7 is a sectional view taken along line AA of FIG. 6, FIG. 8 is a plan view of a relief surface on which the first film is deposited, FIG. 9 is a sectional view taken along line BB of FIG. 8, and FIG. Plan view of the relief surface on which is deposited,
FIG. 11 is a sectional view taken along the line CC of FIG.

First, a relief process serving as a core of a microlens molding surface will be described with reference to FIGS. In FIG. 1, a diamond cutting tool (not shown) having a tip angle of 100 to 140 ° (120 ° in the present embodiment) is brought into contact with a mold substrate 1 which is a disk-shaped forming mother blank finished in a parallel plane. . Next, as shown in FIG. 2, the diamond tool is moved linearly to form one V-groove 2 on the surface of the mold substrate 1. Further, in the same manner, a plurality of linear V-grooves 2 are formed in parallel on the entire surface of the mold substrate 1 at an equal pitch of 5 to 30 μm (15 μm in the present embodiment). Thereafter, as shown in FIG. 3, the mold substrate 1 is rotated by 60 °,
In a similar manner, a plurality of linear V-grooves 2 are arranged in parallel at an equal pitch of 5 to 30 μm (15 μm in the present embodiment) at a uniform pitch.
Is formed on the entire surface. As a result, a rhombic quadrangular pyramid 3 is formed on the entire surface of the mold substrate 1.

Further, as shown in FIG. 4, the mold substrate 1 is further rotated in the same direction by 60 °, and a plurality of linear V-grooves 2 are arranged in parallel in the same manner at an equal pitch of 5 to 30 μm (this embodiment). (In the embodiment, 15 μm). Thereby, as shown in FIGS. 4, 5, 6 and 7,
The hexagonal pyramid 4 and the triangular pyramid 5 are arranged on the entire surface of the mold substrate 1 such that six triangular pyramids 5 are located around the hexagonal pyramid 4 and three hexagonal pyramids 4 are located around the triangular pyramid 5. The combined regular uneven relief surface is formed.

Thereafter, as shown in FIG. 8 and FIG. 9, the regular relief surface of the mold substrate 1 is provided with 6 × 10 ⁻⁴ Pa
Vapor deposition (PVD method, PCVD method, CVD
Method or sputtering method) to deposit the metal. As the deposition of metal proceeds and the first film 6 as a thin film is formed, the valley between the hexagonal pyramid 4 and the triangular pyramid 5 on the uneven relief surface is filled with metal, and the triangular pyramid 5 Almost absorbed by the hexagonal pyramid 4. Further, as shown in FIGS. 10 and 11, when the metal is further deposited by vapor deposition to form the second film 7 as a thin film, the triangular pyramid 5 of the uneven relief surface is completely formed on three adjacent hexagonal pyramids 4. It is absorbed and disappears. At the same time, the ridges and vertices of the hexagonal pyramid 4 on the concave-convex relief surface have rounded corners due to the smoothing effect due to metal deposition, and the microlens forming surface 8
Becomes Thereby, a mold for a reticle having a relief surface in which a large number of microlens molding surfaces 8 are arranged is obtained.

As a specific embodiment, the following Table 1 is used.
As shown in (1), a first film, a second film, and a third film as thin films were sequentially deposited on the relief surface of the mold substrate by 1 μm each.

[0015]

[Table 1]

In addition to the metals used for the first to third films of the first to third embodiments shown in Table 1, TiAlN, DLC and the like may be used as the film material. In addition, the material used for the mold substrate may be any material other than the material shown in Table 1 as long as it can be subjected to relief processing. Further, the thickness of the film and the number of layers of the film can be changed depending on the desired shape of the microlens.

Unlike the method using a plating solution, the method of forming a large number of microlens molding surfaces on the uneven relief surface described above by vapor deposition does not generate hydrogen due to electrolysis, and bubbles are generated in the mold substrate to be plated. Will not adhere. Further, as the plating solution proceeds, impurities in the plating solution precipitate as the plating proceeds, and the plating solution becomes dirty. However, the vapor deposition is performed in a high vacuum, and is hardly affected by impurities or dust. Also, when applying a multi-layer film, the plating solution changes for each film to be plated, so there is adhesion of dust etc. in the middle of the process.However, multi-layer film can be applied in one apparatus. is there. This makes it possible to obtain a reticle mold having a relief surface on which a number of microlens molding surfaces without defects are arranged. In addition, when molding is performed using the reticle mold, a reticle having no image unevenness can be obtained.

According to the present embodiment, it is possible to avoid the occurrence of a defect such as crushing of the microlens forming surface due to the attachment of bubbles or impurities, and to obtain a reticle mold for forming a reticle having no image unevenness. be able to.

[0019]

According to the first, second, or third aspect of the present invention, it is possible to avoid the occurrence of a defect such as crushing of the microlens molding surface due to the attachment of air bubbles or impurities, and to mold a reticle having no image unevenness. A reticle mold that can be obtained.

According to the second or third aspect of the present invention, in addition to the above effects, the action of smoothly rounding the apex and the ridge of the pyramid of the relief surface is performed stepwise in the same apparatus, so that the microlens molding is performed. The surface can be easily formed.

According to the third aspect of the present invention, in addition to the above-described effects, the deposition of the thin film can be reliably advanced, and a smoothing effect on the relief surface can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a mold substrate according to an embodiment of the present invention.

FIG. 2 is a side view and a plan view of a first relief-processed mold substrate according to the embodiment of the present invention.

FIG. 3 is a plan view of a second relief-processed mold substrate according to the embodiment of the present invention.

FIG. 4 is a plan view of a third relief-processed mold substrate according to the embodiment of the present invention.

FIG. 5 is a perspective view of a relief surface of a mold substrate on which relief processing has been completed according to the embodiment of the present invention;

FIG. 6 is a plan view of a relief surface according to the embodiment of the present invention.

FIG. 7 is a sectional view taken along line AA of FIG. 6 according to the embodiment of the present invention;

FIG. 8 is a plan view of a relief surface on which a first film is deposited according to the embodiment of the present invention.

FIG. 9 is a sectional view taken along the line BB of FIG. 8 according to the embodiment of the present invention;

FIG. 10 is a plan view of a relief surface on which a second film according to the embodiment of the present invention is deposited.

FIG. 11 is a sectional view taken along line CC of FIG. 10 of the embodiment of the present invention;

[Explanation of symbols]

 1 type substrate 4 hexagonal pyramid 5 triangular pyramid 6 first film 7 second film

Claims (3)

[Claims] 1. A method of manufacturing a focusing plate mold for manufacturing a diffusion plate used as a focusing plate of an optical system, etc., wherein a regular pyramid-shaped relief surface is provided on a surface of a mold substrate. And a second step of depositing a thin film on the uneven relief surface by vapor deposition and smoothly rounding the apex and ridge of the pyramid of the uneven relief surface. . 2. The method according to claim 1, wherein the second step is performed a plurality of times while changing the type of the thin film. 3. The method according to claim 1, wherein the deposition is performed by PVD, PCVD, C
The method for manufacturing a reticle mold according to claim 1, wherein the method is performed by one of a VD method and a sputtering method.