JP2012225660A - Method for manufacturing phase type diffraction grating for x-ray talbot interferometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of easily and highly accurately manufacturing a phase type diffraction grating for an x-ray Talbot interferometer without requiring an exposure mask.SOLUTION: The method for manufacturing a phase type diffraction grating 10 for an x-ray Talbot interferometer, which is configured by forming a plurality of ridge parts 10b and interposing a resin part 12 between adjacent ridge parts 10b, includes: a mold formation step for cutting groove parts on a mold base material 50 by a single-crystal diamond cutter 200 so that the width of each groove is 4 μm or less; a resin formation step for applying pressure immersion of heated mold to a coating surface of a substrate obtained by applying uncured resin to a surface on which a seed layer is formed, and thereafter cooling the uncured resin to temperature at which the uncured resin is cured, separating the mold from the substrate to form the resin part having a projected part and a groove part; and a formation step of a ridge part of a diffraction grating for forming the ridge parts by electroforming a metal of thickness capable of changing, by π/2, phase of an x-ray to be applied when the groove part obtains an image by an x-ray interferometer to the groove part of the resin part.

Description

  The present invention relates to a method of manufacturing a diffraction grating for a phase type X-ray Talbot interferometer.

When a diffraction grating is used and light from a spatially coherent light source is transmitted, a Talbot effect that forms a self-image of the diffraction grating at a specific distance from the diffraction grating is known. In recent years, an X-ray Talbot interferometer that detects the phase shift of transmitted X-rays using this Talbot effect has been developed. The image obtained by utilizing the Talbot effect and the phase shift of the X-ray has an advantage that the contrast is particularly high with a substance having a small atomic number, compared with the image obtained by the conventional absorption X-ray absorption.
As such an X-ray Talbot interferometer 100, as shown in FIG. 1, a configuration including a first diffraction grating 10, a second diffraction grating 20, and an X-ray image detector 30 is known ( Patent Document 1). As shown in FIG. 2, the first diffraction grating 10 and the second diffraction grating 20 form grooves 10 a and 20 a at a predetermined interval in one direction of a metal plate, and transmit X-rays from the grooves, but are adjacent to each other. In the flange portion 10b between the grooves, the phase of the X-ray is shifted by π / 2, and the X-ray is shielded (absorbed) by the flange portion 20b. As a material for the diffraction grating, gold (Au) having a high X-ray absorption ability is usually used.

In this X-ray Talbot interferometer, when the first diffraction grating is irradiated with X-rays from the X-ray source through the sample, the X-rays transmitted through the groove 10a and the X-rays transmitted and diffracted through the flange 10b interfere with each other. . Then, a self-image of the first diffraction grating 10 appears at a position that is an integral multiple of the Talbot distance d ² / 2λ (d is the period of the diffraction grating, and λ is the wavelength of the X-ray) of the first diffraction grating 10 ( Talbot effect). This self-image is distorted by the sample 4, and this distortion has sample information. The second diffraction grating 20 is disposed at a position where the self-image of the first diffraction grating 10 appears. In the distribution of X-rays transmitted through the second diffraction grating 20, the moire fringes are generated by overlapping the self-images of the first diffraction grating. Therefore, this X-ray distribution is detected by an X-ray image detector, and image analysis is performed to obtain an image of the sample 4. In order to improve the image contrast, it is preferable that the X-ray transmittance of the groove portion 20a of the second diffraction grating 20 is high and the X-ray transmittance of the flange portion 20b is low. Therefore, the second diffraction grating 20 is preferably an amplitude type diffraction grating thicker than the first diffraction grating 10.

Here, in order to generate the Talbot effect, it is necessary to make the buttocks (X-ray absorption part) of the diffraction grating have a period that ensures the coherence of X-rays. Therefore, the period of the buttocks must be about 10 μm or less. Further, in the case of the phase type diffraction grating, the contrast of the self-image becomes the highest when the phase shift amount is π / 2. Therefore, in order to realize this, the thickness of the collar portion (groove depth) is set. It needs to be about 1 to 10 μm, and fine processing and manufacturing techniques are required.
On the other hand, in order to function as an amplitude type diffraction grating, it is preferable that the X-ray transmittance of the groove portion 20a of the diffraction grating is high and the X-ray transmittance of the flange portion 20b is low. For this reason, even if it uses gold | metal | money, it is requested | required to dig the depth of a groove | channel to about 10-100 micrometers. Therefore, the aspect ratio represented by (groove depth) / (groove width) of the diffraction grating becomes very large, making it difficult to manufacture the diffraction grating.

For this reason, a technique for manufacturing a diffraction grating for an X-ray Talbot interferometer by forming a deep groove in a resin by lithography using an exposure mask and forming a flange in the groove by electroforming is disclosed. (See Patent Document 2).
In this technique, a photosensitive resin is applied to a substrate serving as a base for manufacturing a diffraction grating, and pattern exposure is performed using an exposure mask. Thereby, the protrusion part which protrudes in a comb-tooth shape from a board | substrate is formed. And if this protrusion part is immersed in a liquid synthetic resin and a protrusion part is pulled up just before resin hardens | cures, the groove | channel formation body by which the groove | channel was formed in the part corresponded to a protrusion part will be manufactured. Thereafter, the diffraction grating can be manufactured by performing gold plating on the groove portion by electroforming and forming a flange portion between the resin members. In this way, diffraction gratings can be mass-produced.

International Publication No. 2004/58070 Japanese Patent Laying-Open No. 2006-259264 (FIGS. 5, 6, and 8)

  However, in the case of the technique described in Patent Document 2, since the comb-shaped protrusions are resist-formed with a mask, a mask must be prepared for each diffraction grating, and the type and operating conditions of the X-ray source have changed. However, since the interstitial distance changes, there is a problem that the mask must be changed. For example, since phase imaging using an X-ray tube as an X-ray source is a spherical wave, the phase of the grating pattern differs between the phase grating and the amplitude (absorption) grating. Furthermore, the optimum value of the tube voltage of the X-ray tube changes according to the measurement sample, and the position of the self-image where the Talbot effect occurs, that is, the interstitial distance also changes accordingly. Therefore, the mask needs to be changed.

  Accordingly, an object of the present invention is to provide a method for manufacturing a phase type diffraction grating for an X-ray Talbot interferometer, which does not require an exposure mask and can manufacture a phase type diffraction grating easily and with high accuracy.

  The present invention relates to a phase diffraction grating for an X-ray Talbot interferometer, in which a plurality of flanges made of metal or alloy having a predetermined width are formed in one direction at a constant period, and a resin part is interposed between adjacent flanges. A manufacturing method, wherein a plurality of grooves are cut at a constant cycle in one direction with a single crystal diamond blade on a mold base material, and the grooves are irradiated when an image is obtained with the X-ray Talbot interferometer. Deeper than the thickness of the flange portion that changes the phase of the line by π / 2, the width of the protrusion formed between the groove portions adjacent to the groove portion is substantially the same as the width of the groove portion, and the width of the groove is 4 μm or less. A mold forming step, and a temperature at which the uncured resin is cured after being pressure-immersed in a heated state on the coated surface of the substrate on which the uncured resin is coated on the surface on which the seed layer is formed The mold is separated from the substrate by cooling to a protrusion and a groove. A resin forming step of forming a resin portion having a portion, and a thickness of changing the phase of X-rays irradiated to the groove portion of the resin portion when the groove portion obtains an image with the X-ray interferometer by π / 2 A method of manufacturing a phase diffraction grating for an X-ray Talbot interferometer, comprising: a diffraction grating flange forming step of forming a flange by electroforming metal.

  With such a configuration, a resin part is formed by duplicating from a mold having a sharply shaped groove by cutting, and a metal or alloy flange is formed by electroforming the groove part of the resin part. it can. That is, the shape of the mold groove is sharper than that of photolithography, and an exposure mask is not required. Therefore, the phase-type diffraction grating can be mass-produced and manufactured with high accuracy.

The mold base material may be made of a crystal or amorphous material having a Vickers hardness of Hv 100 to 300 and an average particle size of 0.1 μm or less, and the flatness of the cut surface is preferably 0.2 μm or less.
If it does in this way, the structure | tissue of a metal film will become fine and the side wall of the groove part of a mold will be sharply cut at the time of cutting. As a result, a precise resin forming process can be performed.

The said collar part has gold as a main component, and it is good in the thickness of the said collar part being 1.5-3.0 micrometers.
In this way, when the phase diffraction grating is used, the X-ray energy range in which the phase shift amount is π / 2 is 15 to 35 KeV.

The collar part is mainly composed of Ni or Cu, and the collar part preferably has a thickness of 3.0 to 6.0 μm.
In this way, the cost of the diffraction grating can be reduced. Further, when the phase diffraction grating is used, the X-ray energy range in which the phase shift amount is π / 2 is 15 to 35 KeV.

The seed layer is preferably a deposited film of nickel, chromium, or titanium.
In this way, the substrate and the seed layer are securely adhered, and copper or gold can be reliably electroformed from the bottom of the groove.

  According to the present invention, an exposure mask is not required, and a phase diffraction grating for an X-ray Talbot interferometer can be manufactured easily and with high accuracy.

It is a figure which shows schematic structure of an X-ray Talbot interferometer. It is sectional drawing in alignment with the x direction of a 1st diffraction grating and a 2nd diffraction grating. It is process drawing which shows an example of the manufacturing method of the phase type diffraction grating for X-ray Talbot interferometers. FIG. 4 is a process diagram following FIG. 3. It is a perspective view which shows the structure of the diffraction grating for X-ray Talbot interferometers. It is a perspective view which shows the tool main body which attached the single crystal diamond cutting blade. It is a perspective view which shows a single crystal diamond cutting tool. It is a figure which shows the method of forming the groove part of a mold using a single crystal diamond cutting blade.

Hereinafter, embodiments of the present invention will be described. FIG. 1 is a diagram showing a schematic configuration of an X-ray Talbot interferometer 100 using a phase type diffraction grating 10 manufactured according to the present invention. The X-ray Talbot interferometer 100 includes an X-ray source 2, a first diffraction grating 10 and a second diffraction grating 20, and an X-ray image detector 30. The first diffraction grating 10 and the second diffraction grating 20 are arranged parallel to each other by a predetermined distance in the z direction, and the X-ray source 2 is arranged facing the first diffraction grating 10 along the z direction. ing. Further, an X-ray image detector 30 is disposed so as to face the second diffraction grating 20 along the z direction. A sample 4 to be observed is arranged between the first diffraction grating 10 and the X-ray source 2 along the z direction.
The first diffraction grating 10 and the second diffraction grating 20 are formed with a plurality of grooves 10a and 20a that extend along one direction (y direction in FIG. 1) parallel to the plane and are spaced apart from each other at a constant period. (See the cross-sectional view of the groove portion in FIG. 2), while transmitting X-rays from the groove portions 10a and 20a, the phase of the X-ray is shifted by π / 2 at the strip-shaped flange portion 10b between the adjacent groove portions 10a. The X-rays are shielded (absorbed) by the collar 20b. Each groove part 10a, 20a and collar part 10b, 20b are extended in the Y direction of FIG. As a material for the diffraction grating, gold having high X-ray absorption ability is preferably used. In this embodiment, the width (interval) of the flange portion 10b and the width (interval) of the groove portion 10a are equal, and the width (interval) of the flange portion 20b and the width (interval) of the groove portion 20a are equal.

In the X-ray Talbot interferometer 100, when the first diffraction grating 10 is irradiated with X-rays from the X-ray source 2 through the sample 4, X-rays transmitted through the groove 10a and X-rays transmitted and diffracted through the flange 10b are generated. Interfere with each other. Then, a self-image of the first diffraction grating is formed at a position separated by the Talbot distance. That is, the first diffraction grating 10 constitutes a phase type diffraction grating that applies phase modulation to irradiated X-rays. Here, in order to generate the Talbot effect, the period d (see FIG. 2A) of the flange portion of the first diffraction grating 10 is ensured to ensure the coherence of the X-rays irradiated from the X-ray source 2. It needs to be adjusted.
The second diffraction grating 20 disposed behind the first diffraction grating 10 (the position of the self-image) diffracts the X-rays diffracted by the first diffraction grating 10 to form an image contrast. The X-ray image detector 30 behind the second diffraction grating 20 detects the diffracted X-rays. In order to improve the image contrast, it is preferable that the X-ray transmittance of the groove portion 20a of the second diffraction grating 20 is high and the X-ray transmittance of the flange portion 20b is low. Therefore, the second diffraction grating 20 is preferably an amplitude type diffraction grating thicker than the first diffraction grating 10.

Here, since the sample 4 is arranged in front of the first diffraction grating 10 and the irradiated X-rays pass through slightly different optical paths inside the sample 4, the self-image is distorted by the sample 4 due to the phase difference at this time. Arise. When the second diffraction grating 20 is arranged at the position of the self-image, moire fringes are generated in the Talbot interference image (image contrast) and detected by the X-ray image detector 30. Since the amount of modulation that the generated moire fringes receive by the sample 4 is proportional to the angle at which the irradiated X-rays are bent by the sample 4, the sample 4 and its internal structure can be measured by analyzing the moire fringes.
In the fringe scanning method, which is one of the moire fringe analysis methods, the phase of the moire fringe changes by relatively shifting the first diffraction grating 10 and the second diffraction grating 20 in the X direction. Pay attention. That is, a phase image (sample 4 and its internal structure) can be obtained by changing the phase of moire fringes to obtain a plurality of Talbot interference images and then processing and synthesizing them.
It is also possible to obtain a tomographic image (CT image) of the sample 4 by rotating the sample 4 to acquire images from a number of projection directions and combining them.

  The X-ray Talbot interferometer 100 of the present invention also includes a Talbot-Lau interferometer in which a multi slit is disposed between the X-ray source 2 and the sample 4. When a multi-slit is not used, it is necessary to use a microfocus X-ray source as the X-ray source 2, but in the case of a Talbot-Lau interferometer, an X-ray source can usually be used.

By the way, since the wavelength of X-rays is short, in order to ensure coherence, the period of the collar portion of the first diffraction grating 10 and the second diffraction grating 20 must be about 10 μm or less. Further, in the case of the phase type diffraction grating, the contrast of the self-image becomes the highest when the phase shift amount is π / 2. Therefore, in order to realize this, the thickness of the collar portion (groove depth) is set. It needs to be about 1 to 10 μm, and fine processing and manufacturing techniques are required. For example, when the collar part of each diffraction grating is formed of gold, the thickness of the collar part needs to be about 1 to 3 μm, and when it is formed of copper, the thickness of the collar part needs to be about 3 to 10 μm.
On the other hand, in order to function as an amplitude type diffraction grating, it is necessary to increase the X-ray transmittance of the groove portion of the diffraction grating and decrease the X-ray transmittance of the collar portion. For this reason, even if it uses gold | metal | money, it is requested | required that the thickness (depth of a groove | channel) of a collar part should be deepened to about 10-100 micrometers. Therefore, the aspect ratio represented by (groove depth) / (groove width) of the diffraction grating is very large as 3 or more (in some cases, 10 or more).

For this reason, it is necessary to form the flange portion finely and sharpen the shape of the side wall thereof (the unevenness of the side wall of the groove and the radius of curvature of the cutting corners of the side wall and the bottom surface must be finely formed. The present inventors have found that, for example, by cutting a metal film using a single crystal diamond cutting tool having high hardness and capable of precise groove processing, a fine groove portion having a sharp side wall shape can be formed.
Then, a resin part can be formed by using a mold having such a sharp groove as a mold, and a collar part can be formed by electroforming using this resin part as a mold. That is, an exposure mask is not required, the phase type diffraction grating can be mass-produced, and can be manufactured with high accuracy. The phase-type diffraction grating has an aspect ratio expressed by (groove depth) / (groove width) of the diffraction grating of about 0.5 to 2 when the electroformed material is gold. Even if the mold having the mold is used as a mold, it is possible to form a resin mold (and thus a flange portion) with high dimensional accuracy.

Next, an example of a method for manufacturing the X-ray Talbot interferometer phase diffraction grating (first diffraction grating) 10 will be described with reference to FIGS. In FIG. 3A, reference numeral 50x denotes a mold base material, which is cut to form a diffraction grating mold. For example, the mold base material 50x has an average crystal grain size of 0.1 μm or less and a Vickers hardness of Hv 100 to 300. For the mold base material 50x, for example, a nickel phosphorus alloy is used. This material enables precise cutting such as no burrs. Further, the groove processing surface of the mold base material is polished so that the flatness expressed by the difference between the highest point and the lowest point is about 0.2 μm or less. This enables precise cutting with no variation in groove depth.
Next, using a single crystal diamond cutting tool 200 described later, the mold base material 50x is cut along one direction (a direction perpendicular to the paper surface of FIG. 3) with a constant period d to engrave a plurality of groove portions 50a, and mold 50 is formed. The mold 50 has a groove-shaped protrusion 50b between the groove 50a and the adjacent groove 50a (FIG. 3B; mold forming step). The depth p of the groove 50a is cut deeper than the depth of the ridge that changes the phase of the X-ray from the X-ray source 2 by π / 2. Further, if the widths of the groove 50a and the protrusion 50b are substantially the same, a diffraction grating with a clear phase image can be produced. The width of each of the groove 50a and the protrusion 50b is preferably 4 μm or less. Because X-rays have a short wavelength and a small diffraction angle, to obtain effective interference, the distance between the source gratings is increased, the period of the diffraction grating is decreased, the energy of the X-rays is decreased, and the wavelength is increased. There is a need to. Assuming that the width of the groove 50a and the protrusion 50b is 4 μm or less (that is, the period d is 8 μm or less), a practical X-ray energy (10 to 40 keV) is obtained with a practical source lattice distance (within 3 m). An effective interference image can be obtained.

  On the other hand, a liquid uncured resin 12x is applied to the substrate 62 (FIG. 3C). The substrate 62 is a substrate for a diffraction grating, and is preferably made of a material mainly containing at least one selected from the group of carbon, silicon, and aluminum, for example, in order to increase the X-ray transmittance. Specific examples of the composition of the substrate 22 include an amorphous carbon or silicon wafer, or a silicon nitride or silicon carbide membrane. On the surface of the substrate 62, a nickel, chromium, or titanium seed layer 62a having a thickness of about 0.1 μm is formed for electroforming described later. By using the above-mentioned material as the substrate 52, the X-ray transmittance can be increased, and good diffraction characteristics can be obtained. As the uncured resin 12x, for example, SU-8 (Microchem), which is an epoxy negative resist, is used. Then, the uncured resin 12x is spin-coated on the substrate 62 at a main speed of about 1000 to 6000 rpm. Further, the thickness and material of the seed layer 62a are as described above, so that the substrate 62 and the seed layer 62a are in close contact with each other, and the electroforming of copper or gold is reliably performed from the bottom of the groove portion in the flange forming step described later. Can be done.

  Next, in a state heated to a temperature higher than the glass transition temperature of the uncured resin 12x, the mold 50 with the cut side of the groove 50a facing downward is immersed in the uncured resin 12x from above (FIG. 3D). ); Immersion step). At this time, the uncured resin 12x is completely impregnated in the groove 50a. When the uncured resin 12x is SU-8, the glass transition temperature is about 50 ° C., for example, it is heated at 90 ° C. above the glass transition temperature for about 10 minutes. Thereafter, when it is cooled to near room temperature, which is not higher than the glass transition temperature, the uncured resin 12x is cured to become the resin portion 12. When the mold 50 is separated from the substrate 62 after the uncured resin 12x is cured, the groove portion 50a of the mold 50 is transferred to the resin portion 12 to form the protruding portion 12b. Further, the protruding portion 50b of the mold 50 is transferred to form the groove portion 12a. (FIG. 4 (e); resin mold forming step). And the protrusion part 12b and the groove part 12a become substantially the same width | variety below 4 micrometers. In order to reliably perform electroforming in the next step, reactive ion etching is performed on the surface of the mold 50 to completely remove the resin portion 12 remaining on the bottom of the groove portion 12x, thereby exposing the seed layer 62a. . Even after reactive ion etching, the groove portion 12a has a depth equal to or greater than the thickness of the ridge that changes the phase of X-rays from the X-ray source 2 by π / 2. 50a is cut.

  Next, the entire substrate 62 including the resin portion 12 and the seed layer 62a is immersed in an electroplating bath, and electrocasting is performed in the groove portion 12a using the seed layer 62a as a cathode to form the flange portion 10b (FIG. 4F). ; Buttocks formation process). The thickness of the collar portion 10b is set to a thickness that changes the phase of the X-ray to be irradiated by π / 2. In addition, since the depth of the groove part 12a is deeper than the thickness of the collar part 10b, the collar part 10b does not overflow from the groove part 12a. When the collar portion 10b is electroplated with pure gold, the electroplating bath is preferably a non-cyan electrogold plating bath solution that does not erode the resin portion 12 during electroforming. In the case of the collar part 10b which has gold as a main component, the thickness of the collar part 10 is good in it being 1.5-3.0 micrometers. In this way, a clear interference image can be obtained when the X-ray energy range where the phase shift amount is π / 2 when the phase diffraction grating is used is 15 to 35 KeV.

If the collar part 10b is comprised from the metal or alloy which has Ni or Cu as a main component, the cost of a diffraction grating can be reduced.
In the case of the collar part 10b which has copper as a main component, the thickness of the collar part 10 is good in it being 3-6 micrometers. In this way, a clear interference image can be obtained when the X-ray energy range where the phase shift amount is π / 2 when the phase diffraction grating is used is 15 to 35 KeV.
FIG. 5 shows the configuration of the phase diffraction grating 10 for X-ray Talbot interferometer. In the phase diffraction grating 10 for X-ray Talbot interferometer, the resin portion 12 is formed with a plurality of groove portions 12a having a constant period and depth in one direction. The groove portion 12a has a structure in which the flange portion 10b is interposed with a thickness of π / 2 in the X-ray phase shift, and the flange portion 10b functions as a phase type diffraction grating.

Here, the mold 50 serving as a mold for electroforming the flange portion 10b uses a groove 50a formed by cutting as a mold, but as will be described later, as a cutting machine, an ultra-precision nano-processing with a resolution of nm level. By using a machine and cutting with a single crystal diamond cutting tool, the concave and convex portions of the side wall of the groove portion 50a of the mold and the curvature radius of the cutting corner portion between the side wall and the bottom surface of the groove portion are each 0.1 μm or less (FIG. b)). Accordingly, the side wall of the resin portion 12 formed using the groove 50a as a mold also has the same dimensional accuracy, and the dimensional accuracy is reflected on the side wall of the heel portion 10b, so that the ridge portion 10b with high dimensional accuracy is obtained.
The resin portion 12 holds the flange portion 10b and prevents the X-ray absorbing portion 10b from falling or deforming.

Next, a cutting tool having a cutting edge made of single crystal diamond, which is suitable for forming a groove portion of a mold by cutting a metal film, will be described with reference to FIGS. Single crystal diamond has a high hardness and enables precise groove processing.
FIG. 6 shows a tool body (bite) 400 to which a single crystal diamond cutting blade 200 is attached. The single crystal diamond cutting tool 200 is attached to the tip of a substantially trapezoidal base metal 300 to form a tool body 400, and the cutting edge (see FIG. 6) of the single crystal diamond cutting tool 200 protrudes from the tip of the base metal 300. Yes. The tool body 400 is fixed to a holder of a cutting machine (not shown), and a single crystal diamond cutting tool 200 can carve a groove in a workpiece as will be described later.

As shown in FIG. 7, the single crystal diamond cutting tool 200 includes a rake face 201, two first flank surfaces 203 and 204 which are side faces adjacent to the rake face 201, and the rake face 201, respectively. The front flank 205 facing the cutting surface of the object 500, the front cutting edge 210 formed at the boundary between the rake face 201 and the front flank 205, and the boundary between the rake face 201 and the first flank faces 203 and 204 And two first cutting edges 213 and 214 formed in the section. The shapes of the front flank 205 and the rake face 201 are not limited, and may be flat or curved. The rake face 201 has a predetermined rake angle of 0 degrees or a rake angle slightly inclined in the positive direction so as to scoop cutting waste.
The first flank surfaces 203 and 204 or the front flank surface 205 are formed by etching of a focused ion beam (FIB). The FIB etching has an advantage that it can be processed in a complicated shape and can be processed without selecting a crystal plane. Therefore, the (111) plane which is the hardest crystal plane of diamond can be easily processed. On the other hand, for example, polishing with a grindstone cannot polish the (111) face of diamond.
If the width W ₃ of the cutting edge 210 and 4μm or less, it is possible to carve the small groove portion preferably.

  The single crystal diamond cutting tool 200 (tool body 400) described above can be attached to a cutting machine to form the groove 50a as shown in FIG. Here, since the period and depth of the groove formed by the cutting depend on the resolution of the ultra-precision nano-machining machine, it is preferable to use an ultra-precision nano-machining machine having a resolution of nm level as the cutting machine. As an ultra-precision nano processing machine, for example, a product name “FANUC ROBONANO α-0iB” manufactured by FANUC CORPORATION is commercially available. This ultra-precision nano-machining machine controls a linear motor and a synchronous built-in servo motor to directly drive five simultaneous axes with high accuracy and has a resolution of 1 nm on a linear axis.

Using such a processing machine, a single crystal diamond cutting tool 200 as shown in FIG. 6 has a predetermined width along one direction of the mold base material 50x (in the direction of the arrow in FIG. 8) and perpendicular to the one direction. performing a pull cutting process that left a protruding portion of the mold of W _3. As a result, the mold base material 50x is cut to form the groove 50a, and the flange-shaped protrusion 50b can be formed between the adjacent grooves 50a. Note that W ₁ = W ₃ is preferable.

  Here, in order to carve the groove 50a in the mold 50 with the single crystal diamond cutting tool 200, the groove is compared with the conventional technique in which a diffraction grating is manufactured by electroforming in a fine groove (slit) formed using a resist resin. As a result, it is possible to perform excellent processing in which the concave and convex portions on the side wall 50a and the radius of curvature of the cutting corner portion between the side wall and the bottom surface of the groove portion are 0.1 μm or less, and in the fine groove (slit) formed using the resist resin. Compared with the prior art that manufactures a diffraction grating by electroforming, a diffraction grating with higher dimensional accuracy can be obtained. Unlike the technique of manufacturing a diffraction grating using a resist resin, no exposure mask is required.

  In addition, the resin portion 12 that is a mold for electroforming the flange portion 10b is formed by cutting, and the unevenness of its own side wall and the curvature radius of the cutting corner portion between the side wall and the bottom surface of the groove portion are each 0.1 μm or less. Since it is replicated from the mold 50 having a certain groove 50a, the unevenness of the side wall of the flange part 10b and the curvature radius of the cutting corner between the side wall and the bottom surface of the groove part are also reduced to 0.1 μm or less respectively, and the Part 10b is obtained.

  It goes without saying that the present invention is not limited to the above-described embodiment, but extends to various modifications and equivalents included in the spirit and scope of the present invention.

10 Phase diffraction grating for X-ray Talbot interferometer 10a Groove 10b X-ray absorber (saddle)
12 Resin part 12x Uncured resin 50 Mold (base material)
50a (Mold) groove 50b (Mold) protrusion 200 Single crystal diamond cutting tool

Claims (5)

A method of manufacturing a phase type diffraction grating for an X-ray Talbot interferometer, in which a plurality of flanges made of metal or an alloy having a predetermined width are formed in one direction at a constant cycle, and a resin part is interposed between adjacent flanges. There,
Cutting a plurality of grooves at a constant cycle in one direction with a single crystal diamond cutting tool on a mold base material, the phase of X-rays irradiated when the grooves obtain an image with the X-ray Talbot interferometer is π / 2. A mold forming step that is deeper than the thickness of the flange portion to be changed, the width of the protruding portion formed between the groove portions adjacent to the groove portion is substantially the same as the width of the groove portion, and the width of the groove is 4 μm or less; ,
The mold is heated and immersed in the heated surface of the substrate on which the uncured resin is coated on the surface on which the seed layer is formed, and then cooled to a temperature at which the uncured resin is cured. Forming a resin part having a protruding part and a groove part apart from the substrate;
Diffraction in which the flange portion is formed by electroforming a metal having a thickness that changes the phase of X-rays irradiated when the groove portion obtains an image with the X-ray interferometer in the groove portion of the resin portion. A method of manufacturing a phase type diffraction grating for an X-ray Talbot interferometer.   The mold base material is made of a crystal or amorphous material having a Vickers hardness of Hv 100 to 300 and an average particle diameter of 0.1 μm or less, and the flatness of the machined surface is 0.2 μm or less. Item 2. A method for producing a phase type diffraction grating for an X-ray Talbot interferometer according to Item 1.   3. The phase diffraction grating for an X-ray Talbot interferometer according to claim 1, wherein the flange has gold as a main component, and the thickness of the X-ray absorber is 1.5 to 3.0 μm. Production method.   The phase type diffraction for an X-ray Talbot interferometer according to claim 1, wherein the flange portion is mainly composed of Ni or Cu, and the thickness of the X-ray absorption portion is 3.0 to 6.0 μm. A method of manufacturing a lattice.   2. The method of manufacturing a phase diffraction grating for an X-ray Talbot interferometer according to claim 1, wherein the seed layer is a deposited film of nickel, chromium, or titanium.

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