JP2001133615A - Method and device for producing diffraction grating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems for the method of producing a diffraction grating, where a method of cutting many grooves on a substrate by using a diamond tool is used, there is a limit for the resolution for processing, and when a glass substrate is etched by using ion beams, edges of the grating are roughened or the blaze angle is decreased or the blaze depth is decreased. SOLUTION: A transparent conductive film 202 and a metal film 203 are formed on a glass substrate 201, and a processing electrode is disposed facing the surface of the metal film 203. The electrochemical reaction is induced between the top end of the processing electrode and the surface of the metal film 203 to process and remove the metal film 203 and to form many lines on the surface of the metal film 203, while the processing electrode and the glass substrate 201 are relatively moved. Thus, a grating having the transparent conductive film 202 exposed periodically is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a diffraction grating in the fields of optics, electronics, and machinery.

[0002]

2. Description of the Related Art Heretofore, as a method of manufacturing a diffraction grating, a method of forming a large number of grooves on a substrate by cutting using a diamond tool, or a method of etching a glass substrate using an ion beam. Was mainly used. In the method of performing cutting using a diamond tool, a large number of grooves are mechanically cut on the surface of the glass substrate,
In addition to the method of manufacturing a transmission type diffraction grating, by cutting a number of grooves after depositing metal such as aluminum on a glass substrate, or by depositing metal after cutting grooves on the surface of the glass substrate A method of manufacturing a reflection type diffraction grating has also been used.

In a method of etching a glass substrate using an ion beam, a photoresist film is formed on a glass substrate, and the photoresist film is exposed using a mask having a periodic line pattern. A method of manufacturing a diffraction grating by irradiating a beam obliquely and etching a glass substrate and a resist has also been used.

[0004]

However, the above method has the following problems. First, in the method of cutting a large number of grooves using a diamond tool,
Since the processing resolution is limited by the shape of the tip of the processing tool, there is a problem that it is extremely difficult to manufacture a diffraction grating having a high resolution with a line interval of 1 μm or less. In addition, since processing is performed while removing unnecessary parts in a state where the processing tool and the substrate are in contact with each other, when the shape of the diffraction grating is disturbed by processing products such as burrs or when the glass substrate is directly cut, There is a problem that chipping occurs due to high brittleness. Further, as the processing progresses, the processing tool wears, so that the groove width to be processed varies, or the processing tool needs to be replaced at regular intervals. Furthermore, in the method of depositing metal after cutting a groove on the surface of a glass substrate, when depositing metal, there is a problem that it is difficult to form a uniform film at peaks and valleys of the diffraction grating. there were.

Next, in the method of etching a glass substrate by using an ion beam, the etching rate of the photoresist may be faster than the etching rate of the glass, so that the edge may be blurred or the blaze angle may be reduced. There have been problems such as a value smaller than a desired value and a shallow blaze depth. Further, since the line spacing of the diffraction grating depends on the mask shape when exposing the photoresist, there is a problem that the line spacing is limited by the resolution of the photoresist and the mask.

[0006]

In order to solve the above-mentioned problems, the diffraction grating manufacturing method and the diffraction grating manufacturing apparatus of the present invention use the following means. First, in a method of manufacturing a transmission type diffraction grating by the diffraction grating manufacturing method of the present invention, a substrate having a light-shielding film formed on a surface of a substrate having light transmitting properties and electrical conductivity is used as a material. use. As such a substrate, for example, a substrate in which a transparent conductive film is formed over a glass substrate and a metal film is formed over the transparent conductive film can be used.

[0007] A processing preparation step of arranging the processing electrode and the light-shielding film surface of the substrate so as to face each other at a certain distance in a non-contact state, and applying a voltage between the processing electrode and the substrate. A processing step of causing a physical or chemical processing phenomenon between the tip of the processing electrode and the surface of the light-shielding film to selectively remove only a region of the light-shielding film near the processing electrode tip, And a moving step of relatively moving the substrate and the substrate. By repeating these three steps simultaneously or in an arbitrary order, a region where light is transmitted and a region where light is shielded on the surface of the substrate have a specific regularity. The diffraction grating is manufactured by holding and arranging.

Here, the processing phenomena include, for example, a discharge phenomenon by applying a voltage between the processing electrode and the substrate, and a processing by applying a voltage between the processing electrode and the substrate in the electrolyte solution. A possible electrochemical reaction may be considered, but is not limited thereto. As another means, a substrate having a property of transmitting light and having electrical conductivity, for example, a glass substrate on which a transparent conductive film is formed is used as a material, and the processing electrode and the substrate are kept at a certain distance. A processing preparation step of disposing them facing each other in a non-contact state, and applying a voltage between the processing electrode and the substrate to physically or chemically separate the tip of the processing electrode and the surface of the light shielding film. A processing step of generating a processing phenomenon and selectively adding a light-shielding substance only to a region near the processing electrode tip of the substrate; and a moving step of relatively moving the processing electrode and the substrate. Two processes at the same time,
Alternatively, the diffraction grating is manufactured by repeatedly arranging the light-transmitting region and the light-shielding region on the surface of the substrate with a specific regularity by repeating the process in an arbitrary order. As a processing phenomenon in this case, in an electrolyte solution, an electrochemical reaction such as plating caused by applying a voltage between a processing electrode tip and a substrate can be used, but is not limited thereto. .

On the other hand, as a method of manufacturing a reflection type diffraction grating, a substrate having a property of reflecting light and having electrical conductivity, for example, a metal substrate such as chromium is used as a material.
A processing preparation process in which the processing electrode and the substrate are arranged facing each other in a non-contact state at a certain distance, and a voltage is applied between the processing electrode and the substrate to reduce physical or chemical processing phenomena. Generating and selectively removing only a region of the substrate near the tip of the processing electrode, and a moving process of relatively moving the processing electrode and the substrate. These three processes are performed simultaneously or in any order. By repeatedly arranging the fine irregularities on the surface of the substrate with a specific regularity, a reflective diffraction grating is manufactured. The processing phenomenon in this case also includes, for example, a discharge phenomenon caused by applying a voltage between the processing electrode and the substrate, and an electrochemical phenomenon caused by applying a voltage between the processing electrode and the substrate in an electrolyte solution. A reaction may be considered, but the present invention is not limited to this.

Further, in the above-mentioned processing step of the reflection type diffraction grating, a voltage is applied between the processing electrode and the substrate to cause a physical or chemical processing phenomenon, and the substrate near the processing electrode tip end portion is processed. By using a method of selectively adding a substance only to a region, a reflective diffraction grating can be manufactured by arranging fine irregularities on the surface of a substrate with a specific regularity. In this case, as the processing phenomenon, an electrochemical reaction such as plating by applying a voltage between the tip of the processing electrode and the substrate in the electrolyte solution can be used, but the processing phenomenon is not limited to this.

On the other hand, in the diffraction grating manufacturing apparatus of the present invention, a holding means for holding the processing electrode and the substrate in an opposed manner at an arbitrary distance, and a moving means for arbitrarily changing the relative position between the processing electrode and the substrate. A voltage application means for applying a voltage between the processing electrode and the substrate; and a voltage / current control means for controlling a voltage and a current flowing between the processing electrode and the substrate, and a transmission type or a reflection type. Can be manufactured.

In the diffraction grating manufacturing method and the diffraction grating manufacturing apparatus according to the present invention, the processing is performed in a state where the processing electrode and the surface are not in contact with each other, and no reaction force is applied to the processing electrode, so that the tip can be sharpened. is there. Therefore, a diffraction grating with high resolution can be manufactured. Further, since the processing is performed by utilizing the discharge phenomenon and the electrochemical reaction, chipping does not occur as in the case of cutting the glass substrate by machining. Furthermore, since the shape of the groove in the reflection type diffraction grating can be controlled by the shape of the tip of the processing electrode, the edge is dropped, the blaze angle is smaller than a desired value, and the blaze depth becomes shallow. Such a problem does not occur, and the interval between the grooves can be set arbitrarily, so that it is not necessary to manufacture a mask.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 shows an example of a diffraction grating manufacturing apparatus according to the present invention. The diffraction grating manufacturing apparatus includes a workpiece 103 immersed in an electrolyte 102 in an electrolyte container 101, a processing electrode 104 for processing the workpiece 103 by an electrochemical reaction, and a reference for electrode potential. A reference electrode 105, a potential / current control device 110 for controlling the potential and current of the workpiece 103 and the processing electrode 104, and a lower part of the electrolytic solution container 101 are provided. XY stage 106 that can be moved in
And a Z-axis stage 107 installed below the XY-axis stage 106 and capable of moving the workpiece 103 in the Z-axis direction (vertical direction), and moving positions of the XY-axis stage 106 and the Z-axis stage 107 Position control device 108 for controlling the distance between the workpiece 103 and the tip of the processing electrode 104.
It is composed of The processing electrode 104 is a rod-shaped body,
The tip is sharpened, only a part of the tip is exposed, and the other part is covered with an insulator. As the material of the rod-shaped body, for example, carbon, tungsten, platinum or the like is used.

The reference electrode 105 is a cylindrical body of glass. A liquid junction is provided at the tip of the side immersed in the electrolytic solution 102, and a thin line made of silver reaches the glass film at the center of the cylindrical body. And filled with a silver chloride solution to immerse the fine wires. The potential / current control device 110
A voltage is applied between the workpiece 103 and the processing electrode 104 to set a current flowing between the workpiece 103 and the processing electrode 104 to a desired value. The vicinity of the tip of the tip 104 can be removed or a substance can be deposited near the tip.

The XY-axis stage 106 and the Z-axis stage 107 can move the workpiece 103 in the XY-axis direction and the Z-axis direction by electric driving means under the control of the movement position control device 108. . The inter-electrode distance control device 109 arbitrarily controls the distance between the tip of the processing electrode 104 and the surface of the workpiece 103. In the present embodiment, as a distance control method, first, a contact point between the tip end of the processing electrode 104 and the surface of the workpiece 103 is detected, and based on the contact position at this time, the Z-axis stage 107 is thereafter moved. By driving and lowering the workpiece 103 by a desired distance, the distance between the tip of the processing electrode 104 and the surface of the workpiece 103 is set to a desired distance. Here, as a method of detecting the contact between the tip of the processing electrode 104 and the surface of the workpiece 103, for example, an electric resistance value between the processing electrode 104 and the workpiece 103 is measured and the contact is measured. For example, a method utilizing the change in the electrical resistance of the above.

An example of a method for manufacturing a diffraction grating by this apparatus will be described with reference to FIGS. FIG.
FIG. 4 is a process sectional view illustrating a process of a first example of the diffraction grating manufacturing method according to the present invention, and FIG. 3 is a flowchart illustrating a procedure of the first example of the diffraction grating manufacturing method according to the present invention.
First, as shown in FIG. 2B, a transparent conductive film 20 is formed on the surface of the glass substrate 201 as shown in FIG.
2 is formed, and then a metal film 203 is formed on the surface of the transparent conductive film 202 as shown in FIG. The transparent conductive film 202 has a property of transmitting light incident on the diffraction grating, and when the incident light is visible light, an oxide of tin or indium is used, but the invention is not limited thereto. . On the other hand, when the incident light is visible light, a thin film of aluminum, chromium, or the like can be used for the metal film 203, but other metals can be used. Further, as a method of forming a film, vapor deposition, sputtering, C
There are methods such as VD and plating.

Next, the substrate shown in FIG. 2C is placed inside the electrolytic solution container 101 as the workpiece 103, and the surface of the metal film 203 and the tip of the processing electrode 104 are controlled by the interelectrode distance control device 109. Is set to a desired distance. Then, by the potential / current control device 110,
A voltage is applied between the processing electrode 104 and the workpiece 103,
Scanning the XY-axis stage 106 so that the tip of the processing electrode 104 moves along a parallel line at regular intervals on the surface of the metal film 203 while performing the removal processing of the surface of the metal film 203. As a result, as shown in FIG. 2D, the transparent conductive film 202 is exposed, and a diffraction grating in which a light transmitting region and a light shielding region are arranged with regularity can be formed.

In this apparatus, a diffraction grating can be manufactured by the method shown in FIGS. 4 and 5 in addition to the above method. FIG. 4 is a process cross-sectional view illustrating a process of the second example of the diffraction grating manufacturing method according to the present invention,
FIG. 5 is a flowchart showing a procedure of a second example of the diffraction grating manufacturing method according to the present invention. In this method, first, a transparent conductive film 202 is formed on a surface of a glass substrate 201 as shown in FIG. 4A as shown in FIG. Next, the substrate shown in FIG. 4B is placed inside the electrolytic solution container 101 as the workpiece 103, and the distance between the surface of the transparent conductive film 202 and the tip of the processing electrode 104 is controlled by the interelectrode distance control device 109. The desired separation distance is set. The processing electrode 104 and the workpiece 10 are controlled by the potential / current control device 110.
3, a voltage is applied only to the vicinity of the tip of the processing electrode 104 on the surface of the transparent conductive film 202 and the light-shielding substance 40 is applied.
1. An XY-axis stage 106 such that the tip of the processing electrode 104 moves along a parallel line at a constant interval on the surface of the transparent conductive film 202 while depositing a metal, for example.
By scanning, it is possible to form a diffraction grating in which a light-transmitting area and a light-shielding area are regularly arranged on the substrate, as shown in FIG.

Further, in this apparatus, a reflection type diffraction grating can be manufactured by the method shown in FIGS. FIG. 6 is a process sectional view showing a process of a third example of the diffraction grating manufacturing method according to the present invention, and FIG. 7 is a flowchart showing a procedure of the third example of the diffraction grating manufacturing method according to the present invention. . In this method, first, a metal plate 601 as shown in FIG. 6A is used as a substrate, this metal plate is set as a workpiece 103 in an electrolytic solution container 101, and the metal distance is controlled by an inter-electrode distance control device 109. Board 601
Is set to a desired distance between the surface of the workpiece and the tip of the processing electrode 104. And the potential / current control device 11
0, a voltage is applied between the processing electrode 104 and the workpiece 103 to remove the surface of the metal plate 601, and the tip of the processing electrode 104 moves at a predetermined interval on the surface of the transparent conductive film 202. By scanning the XY-axis stage 106 so as to move along a parallel line, a reflection type diffraction grating having a periodic step formed on the substrate as shown in FIG. Can be obtained. Here, the removal processing is performed on the metal plate 601, but a periodic step can be formed by performing additional processing on the surface of the metal plate 601 to form a reflection type diffraction grating. . Further, by making the tip of the processing electrode 104 tapered and performing the same operation, a reflection type diffraction grating having a blaze angle as shown in FIG. 6C can be manufactured. At this time, an arbitrary blaze angle can be set depending on the shape of the processing electrode 104. On the other hand, it is also possible to similarly create a shape having an arbitrary blaze angle by making the tip shape of the processing electrode 104 smaller and performing the removal processing a plurality of times while changing the separation distance or the applied voltage.

In this embodiment, an example is shown in which a substrate having a transparent conductive film formed on the surface of a glass substrate is used as a material having light transmittance and conductivity.
It is not limited to this. (Embodiment 2) In this embodiment, the diffraction grating manufacturing method and the manufacturing apparatus described in Embodiment 1 are used, and a 1 cm
A specific example in which a periodic groove is formed in a region of 1 cm will be described. First, a transparent electrode having a thickness of 500 μm was formed on a 1 cm × 1 cm × 0.5 cm glass substrate by sputtering, and a 300 nm-thick nickel thin film was further evaporated thereon. Then, using the diffraction grating manufacturing apparatus of FIG. 1, etching patterns having a width of 200 nm were formed on the nickel thin film at intervals of 500 nm. 14 g / l of NaClO ₃ was used as an etching solution for nickel, and a platinum-iridium alloy wire whose tip was sharpened by electrolytic etching and a portion other than the tip was covered with a resin was used as the processing electrode 104. The applied current at the time of nickel removal processing is Ion = 1 mA, Ton = 0.3
Seconds, and a pulse current of Toff = 0.3 seconds. (Embodiment 3) FIG. 8 shows another example of the case where the diffraction grating manufacturing apparatus of the present invention is constituted. The diffraction grating manufacturing apparatus includes a processing object 103 immersed in a processing liquid 802 in a processing liquid container 801, a processing electrode 104 for performing processing on the processing object 103 by electric discharge machining, and a processing object 1.
A voltage control device 810 that controls a voltage applied between the electrode 103 and the processing electrode 104 and a voltage control device 810 that is installed below the processing liquid container 801 and can move the workpiece 103 in the XY axis direction (horizontal direction). An XY-axis stage 106, a Z-axis stage 107 installed below the XY-axis stage 106 and capable of moving the workpiece 103 in the Z-axis direction (vertical direction), an XY-axis stage 106, and a Z-axis stage 1
07, a movement position control device 108 for controlling the movement position.
And an inter-electrode distance control device 109 for setting a separation distance between the workpiece 103 and the tip of the machining electrode 104.

The processing electrode 104 is a needle-like or rod-like body, and the tip is sharpened. As the material of the rod-shaped body, any conductive material having a certain level of mechanical strength can be used. For example, graphite, copper alloy, tungsten alloy and the like can be used. Voltage control device 810
Applies a voltage between the workpiece 103 and the processing electrode 104 to cause a discharge phenomenon, thereby causing the workpiece 103
The vicinity of the tip of the processing electrode 104 is removed. At this time, by adjusting the magnitude of the applied voltage, the amount removed by the discharge phenomenon can be controlled.

Except for this, the configuration is almost the same as that of the first embodiment.
7, the workpiece 103 can be moved in the XY-axis direction and the Z-axis direction by the electric driving means under the control of the movement position control device 108, and the inter-electrode distance control device 109 This is an apparatus for setting the distance between the tip of the processing electrode 104 and the surface of the workpiece 103 to a desired distance.

According to this device, the same effect as in the first embodiment can be obtained. (Embodiment 4) FIG. 9 shows Embodiment 4 of the present invention. The present embodiment is substantially the same as the first embodiment, but detects the tunnel current flowing between the processing electrode 104 and the workpiece 103 to detect the tip of the processing electrode 104 and the workpiece 103. An electrochemical STM controller 901 capable of measuring and controlling the distance to the surface, and a piezo scanner 9 for controlling the horizontal and vertical minute movement positions of the processing electrode 104 with high precision.
02.

The electrochemical STM control device 901 has a potential
The piezo scanner 9 is connected to the current control device 110 and the piezo scanner 902, and measures the distance between the tip of the processing electrode 104 and the surface of the workpiece 103 from the tunnel current detected by the potential / current control device 110.
02 can be controlled in a desired distance interval by driving in the Z-axis direction.

According to this apparatus, the tip of the machining electrode 104 and the workpiece 10 are utilized by utilizing the tunnel current.
Since the distance from the surface 3 can be controlled on the order of nanometers, a very high processing resolution can be obtained. Therefore, it is possible to form a very high-resolution diffraction grating with a groove interval of the order of nanometers.

According to this device, the same effect as in the first embodiment can be obtained. (Fifth Embodiment) FIG. 10 shows a fifth embodiment of the present invention. This embodiment is substantially the same as the first embodiment, except that the work piece 1
03 is provided with a rotation stage 1001 capable of rotating the Z around the Z axis.

According to this apparatus, the rotary stage 1001
Is rotated while simultaneously controlling the distance between the tip of the processing electrode 104 and the surface of the workpiece 103 by the inter-electrode distance control device 109. In a diffraction grating of the type described above, a region through which light is transmitted and a region through which light is not transmitted, and in a reflection type diffraction grating, a diffraction grating in which minute steps are arranged on concentric circles can be manufactured. , And curved diffraction gratings can be manufactured.

According to this device, the same effect as in the first embodiment can be obtained.

[0029]

According to the diffraction grating manufacturing method and the diffraction grating manufacturing apparatus of the present invention, the following effects can be obtained. 1. Since the processing is performed in a state where the processing electrode and the surface are not in contact with each other, and no reaction force is applied to the processing electrode, the tip can be sharpened. Therefore, a high-resolution diffraction grating can be manufactured.

2. Since the processing is performed by utilizing an electrochemical reaction or a discharge phenomenon, the shape of the diffraction grating is not disturbed by the generation of a processing product, and chipping does not occur as in the case of cutting a glass substrate. 3. Since the shape of the diffraction grating is controlled by the shape of the tip of the processing electrode, as in the case of etching a glass substrate with an ion beam, the edge of the diffraction grating is blunted, the blaze angle is smaller than a desired value, or the blaze depth is reduced. There is no problem such as the shallowness. Further, since the interval between the grooves can be set arbitrarily, there is no need to manufacture a mask.

4. Applying the technology of the scanning tunneling microscope to control the distance between the tip of the processing electrode and the processing surface with high precision, it is possible to control the spacing between the grooves on the order of nanometers, resulting in extremely high resolution. A diffraction grating can be manufactured. 5. By using the rotary stage, it is possible to manufacture not only a plane diffraction grating but also a curved diffraction grating with the same apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a diffraction grating manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a process sectional view showing a first example of a diffraction grating manufacturing method according to the present invention.

FIG. 3 is a flowchart showing a first example of a diffraction grating manufacturing method according to the present invention.

FIG. 4 is a process sectional view showing a second example of the diffraction grating manufacturing method according to the present invention.

FIG. 5 is a flowchart showing a second example of the diffraction grating manufacturing method according to the present invention.

FIG. 6 is a process sectional view showing a third example of the diffraction grating manufacturing method according to the present invention.

FIG. 7 is a flowchart showing a third example of the diffraction grating manufacturing method according to the present invention.

FIG. 8 is a schematic diagram showing a diffraction grating manufacturing apparatus according to Embodiment 3 of the present invention.

FIG. 9 is a schematic diagram showing a diffraction grating manufacturing apparatus according to Embodiment 4 of the present invention.

FIG. 10 is a schematic view showing a diffraction grating manufacturing apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

 103 Workpiece 104 Processing electrode 106 XY-axis stage 107 Z-axis stage 108 Moving position control device 109 Interelectrode distance control device 110 Potential / current control device 810 Voltage control device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ichikichi Furuta 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba F-term (reference) in Seiko Instruments Inc.

Claims (7)

[Claims] In a process of manufacturing a transmission type diffraction grating, a substrate having a light-shielding film formed on a surface of a substrate having light transmitting properties and electric conductivity is used as a material, A processing preparation step of arranging the light-shielding film at a predetermined distance so as to face each other in a non-contact state, and applying a voltage between the tip of the processing electrode and the light-shielding film to physically or chemically A processing step of causing a temporary processing phenomenon to selectively remove the light-shielding film near the tip portion of the processing electrode; and a moving step of relatively moving the processing electrode and the substrate, and Performing the processing preparation step, the processing step, and the moving step simultaneously or in an arbitrary order is repeated an arbitrary number of times, and a light transmitting region and a light shielding region are defined on the surface of the substrate by a specific rule. sex A method of manufacturing a diffraction grating, comprising: 2. In a process of manufacturing a transmission type diffraction grating, a substrate having properties of light transmission and electrical conductivity is used as a material, and a processing electrode and the substrate are separated from each other by a predetermined distance to be in a non-contact state. A processing preparation step of arranging and facing each other, by applying a voltage between the tip of the processing electrode and the substrate, a physical or chemical processing phenomenon occurs, and the vicinity of the tip of the processing electrode A processing step of selectively adding a substance having a light-shielding property on the substrate; and a moving step of relatively moving the processing electrode and the substrate, and the processing preparation step, the processing step, and Simultaneously performing the moving step or repeating in an arbitrary order an arbitrary number of times, on the surface of the substrate, a light transmitting region and a light shielding region are arranged with a specific regularity. Diffraction grating manufacturing method. 3. In a process of manufacturing a reflection type diffraction grating, using a substrate having a property of reflecting light and having electrical conductivity as a material, a processing preparation step of arranging a processing electrode and the substrate so as to face each other, A processing step of applying a voltage between the tip of the processing electrode and the substrate to generate a physical or chemical processing phenomenon and selectively removing the substrate near the tip of the processing electrode. And a moving step of relatively moving the processing electrode and the substrate, and performing the processing preparation step, the processing step, and the moving step simultaneously or in any order. A method of manufacturing a diffraction grating, wherein minute irregularities are repeatedly arranged on the surface of the substrate with a specific regularity. 4. In a process of manufacturing a reflection type diffraction grating, using a substrate having a property of reflecting light and having electrical conductivity as a material, a processing preparation step of arranging a processing electrode and the substrate so as to face each other; By applying a voltage between the tip of the processing electrode and the substrate, a physical or chemical processing phenomenon occurs, and a substance is selectively added to the substrate near the tip of the processing electrode. And a moving step of relatively moving the processing electrode and the substrate, and that the processing preparation step, the processing step, and the moving step are performed simultaneously or in any order. A method of manufacturing a diffraction grating, comprising arranging minute irregularities with a specific regularity on the surface of the substrate repeatedly for an arbitrary number of times. 5. The diffraction grating fabrication method according to claim 1, wherein the processing phenomenon is an electrochemical reaction caused by applying a voltage in an electrolyte solution. . 6. The method according to claim 1, wherein the machining phenomenon is an electric discharge machining phenomenon caused by applying a voltage. 7. A diffraction grating manufacturing apparatus for manufacturing a transmission type or a reflection type diffraction grating, comprising: holding means for holding a processing electrode and a substrate in a form facing each other at an arbitrary distance; Moving means for arbitrarily changing the relative position; voltage applying means for applying a voltage between the processing electrode and the substrate; and a voltage / current for controlling a current flowing between the voltage and the processing electrode and the substrate. An apparatus for producing a diffraction grating, comprising: a current control means.