JP2000035500A - Working method and working device for material using x-ray irradiation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working method and a device for a material, realizing a work having an inclination that changes continuously or in stages. SOLUTION: In this material working method using X-ray irradiation, by irradiating a material 16b with X-rays, the material 16b is removed, or physical or chemical properties of the material 16b is changed. The X-rays are controlled so that energy distribution of above X-rays is continuously changed in a plane parallel to a surface 16f of the material 16b. In this material working method using X-ray irradiation and a working device, each several part of the material 16b is worked by a depth corresponding to the energy distribution of the X-rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method and apparatus using X-rays for irradiating a work material with X-rays to realize a fine three-dimensional part. More specifically, the present invention relates to a processing method and a processing apparatus for processing precise three-dimensionally shaped parts that can be used in precision equipment such as micromachines and information-related equipment by utilizing the features of X-ray linearity and short wavelength. Things.

[0002]

2. Description of the Related Art As the integration of electronics and mechanical parts such as information communication equipment and micromachines advances, not only electronic parts but also mechanical parts are required to be processed with minute and high precision. The main purpose of semiconductor microfabrication technology that supports the development of electronics is two-dimensional microfabrication, and processing of several microns at most in the depth direction is the limit.

On the other hand, machining of mechanical parts requires machining of a three-dimensional structure having an order of several microns to several hundreds of microns in the depth direction. Therefore, high-precision three-dimensional shape machining technology is required. However, it has been difficult for conventional processing methods to meet these requirements.

As a processing technique conventionally used as an effective technique for solving the above-mentioned problem, there is an X-ray irradiation processing which makes use of the features of X-rays having a straightness and a short wavelength. However, this conventional processing method using X-ray irradiation cannot solve the above problem. The reason is that resist patterning by X-ray lithography
Although two-dimensional micromachining on the order of submicrons is possible, the dimension that can be machined in the depth direction is several microns at most,
It cannot be applied to the processing of a three-dimensional structure such as a mechanical part having an order of several microns to several hundred microns in the depth direction described above.

On the other hand, an etching method by ablation using X-ray irradiation or a processing method called LIGA using cutting of a polymer chain by X-ray irradiation can process a few hundred microns or more in the depth direction. However, material processing in a direction parallel to the direction of incidence of X-rays, that is, in many cases, X-rays are perpendicularly incident on the substrate, so there is a great restriction that only material processing in the direction perpendicular to the substrate can be performed.

Here, an outline of a technique called LIGA will be described. LIGA is a technique proposed in Germany, whose name is acronym for lithography, electroplating and molding in German. As the name implies, a three-dimensional structure is formed using a lithographically patterned resist having a thickness of several tens to several hundreds of mm, and a metal electroplated using the resist.

That is, first, as shown in FIG. 16A, the surface of the substrate 1 is made of polymethyl methacrylate (PM).
MA) is applied with a thickness of several tens to several hundreds μm, and the resist 2 is patterned by a lithography technique of irradiating an X-ray from a synchrotron light source (not shown) through an X-ray mask 3. A pattern is formed on the X-ray mask 3 using, for example, gold 3a (Au) having a thickness of several μm as an X-ray absorbing material. The resist 2 is exposed through the X-ray mask 3 with X-rays having a short wavelength and a small spread radiated from the synchrotron light source, developed and developed, and the exposed portions are removed to thereby achieve a high aspect ratio (opening of 100 or more). A microstructure of the resist 2 made of PMMA having a ratio of depth to width can be formed (FIG. 16).
Middle (b)).

Next, as shown in FIG. 16 (c), electroplating is performed using the resist 2 as a mold. Finally, as shown in FIG. 16 (d), the resist 2 is removed and the electroplating is performed. A three-dimensional microstructure 4 made of the deposited metal is formed. If the metal microstructure 4 thus formed is used as a mold for a plastic or ceramic mold, it is possible to mass-produce high-precision microparts at low cost. As described above, LIGA is an excellent technique capable of processing a three-dimensional structure having an order of several hundreds of μm in the depth direction. There is a major restriction that only material processing in the vertical direction can be performed.

As a method of processing a three-dimensional structure by LIGA, there is a method of preparing a plurality of X-ray masks having different transmission patterns and performing a plurality of X-ray exposures while sequentially replacing these X-ray masks. Proposed. However, this method requires (1) a high manufacturing cost due to the need for a plurality of X-ray masks, (2) the alignment is required during multiple exposures, and the manufacturing process is complicated, and (3) the realizable structure is deep. There is a problem that it cannot be applied to an application that requires a smooth inclined processing surface having no step because it has a step-like step in the vertical direction.

As a method of realizing a smooth inclined surface having no steps in the above-mentioned LIGA, a method of obliquely incident X-rays on a substrate has been proposed. However, this method has a problem that the inclination direction is limited to one direction, and it is impossible to form a hole having a shape in which the inclination direction changes continuously or stepwise, such as a cone or a quadrangular pyramid.

[0011]

As described above, in a conventional processing method using X-ray irradiation, an X-ray mask having a pattern formed of a material that does not transmit X-rays is used to protect a portion that is not processed. Only the parts used and processed are exposed to X-ray irradiation. At that time, a device has been devised so that uniform X-ray irradiation is performed on the processed surface. When there is an in-plane distribution of the X-ray irradiation energy, or when the substrate area is larger than the X-ray irradiation area, the substrate and the mask are kept integrated with each other and the substrate and the mask are continuously connected to the X-ray source. , The influence of the difference between the in-plane distribution and the substrate area and the X-ray irradiation region is prevented.

Further, in X-ray lithography in a semiconductor process, uniform X-ray irradiation is performed in a mask, and processing on the entire surface of a large-area wafer is realized by moving the substrate in a certain step. ing. In these conventional techniques, the basic idea is to perform uniform X-ray irradiation on the processing surface, and as described above, for example, the inclination direction such as a cone or a pyramid is continuous or stepwise. It was not possible to machine a hole having a shape that changed to.

[0013]

SUMMARY OF THE INVENTION The present invention makes use of the features of X-rays having a straightness and a short wavelength, and has a fine processing surface which is not parallel to the direction of incidence of X-rays. The present invention provides a method and an apparatus for realizing a process having a slope that changes continuously or stepwise with respect to. Therefore, the method of processing a material using X-ray irradiation according to claim 1 of the present invention removes the material by irradiating the material with X-rays or changes the physical and chemical properties of the material. In the method of processing a material using X-ray irradiation, the X
By controlling the energy distribution of the line to be continuously changed, processing at a depth corresponding to the energy distribution of the X-ray is performed in each part of the material.

As shown in FIG. 1, the processing depth increases as the X-ray irradiation energy on the surface of the material to be processed increases. Here, the processing depth includes not only the case where the material is removed by X-ray energy but also the case where the material is modified by X-ray energy and the altered layer is removed by a subsequent chemical treatment or the like.

The material is three-dimensionally controlled by controlling the energy distribution of the X-rays radiated on the surface of the material during processing in a plane parallel to the surface of the material according to the depth to be processed for each processed portion. Processing becomes possible. As a method of controlling the energy distribution of X-rays in accordance with the depth to be processed for each processing portion, when irradiating X-rays to a narrow beam and scanning the X-rays on the material surface to draw a pattern, the irradiation time is reduced. A method of controlling or controlling the beam intensity, inserting an X-ray mask for controlling the transmission amount of X-rays between the X-ray source and the workpiece when irradiating a certain surface with X-ray energy, A method of moving the X-ray mask or changing the pattern of the X-ray mask can be considered.

According to a second aspect of the present invention, there is provided an apparatus for processing a material using X-ray irradiation, wherein the material is removed by irradiating the material with X-rays from an X-ray source, or the material is physically or chemically treated. In an apparatus for processing a material using X-ray irradiation that changes properties, the X-ray is irradiated on a plane parallel to a surface of the material.
It is characterized by having control means for controlling the energy distribution of the line to change continuously. The processing depth in each part of the material is controlled by continuously changing the energy distribution of X-rays applied to each part of the material by the control means.

According to a third aspect of the present invention, in the apparatus for processing a material using X-ray irradiation, the control means is disposed between the X-ray source and the material. Characterized in that it has an X-ray mask capable of changing the transmission pattern. Thus, X in the X-ray mask
By varying the transmission pattern of the line, the energy distribution of the X-ray in each part of the material can be changed continuously.

The X-ray mask capable of changing the X-ray transmission pattern includes a substrate formed of an X-ray transmission material,
An electromagnetic wave of a wavelength other than X-rays or an electric signal that deposits or dissolves an X-ray absorbing material at a desired position as a two-dimensional pattern, or an array of micro shutters that can transmit or absorb X-rays Those arranged in a shape can be used.

According to a fourth aspect of the present invention, in the apparatus for processing a material using X-ray irradiation, in the configuration of the second aspect, the control means may include one or a plurality of elements disposed between the X-ray source and the material. It is characterized by having a plurality of X-ray masks and a first moving means for moving the X-ray mask relative to the material. As a method of moving the X-ray mask by the first moving means, the X, Y, and Z axes fixed to the material to be processed are considered.
Movement in the Y and Z axis directions and rotation around the X, Y and Z axes are conceivable. As described above, by moving the X-ray mask having a constant X-ray transmission pattern, it is possible to continuously change the energy distribution of the X-ray in each part of the material.

According to a fifth aspect of the present invention, in the apparatus for processing a material using X-ray irradiation according to the fourth aspect of the present invention, the first moving means includes the one or a plurality of X-ray masks for the surface of the material. Characterized in that the material is relatively moved in one or a plurality of axial directions with respect to the material in a plane substantially parallel to.

According to a sixth aspect of the present invention, there is provided an apparatus for processing a material using X-ray irradiation according to any one of the second to fifth aspects. It has a second moving means for relatively moving in one or more axial directions within a plane substantially parallel to the surface of the material.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Here, a three-dimensional shape is processed into PMMA (polymethyl methacrylate) using X-rays. For the X-ray processing of PMMA, it is preferable to use a light source that generates synchrotron radiation (SR) light with high intensity and good transparency and directivity.

As shown in FIG. 2, in this embodiment,
A superconducting small synchrotron radiation light source 10 (hereinafter, referred to as SR light source 10) was used. This SR light source 10 is a very small light source with an application to semiconductor lithography and the like in mind.
m and very compact.

The light emitted from the SR light source 10 is white light including a wavelength range from visible to X-ray, but here, a beryllium filter 11 and a polyimide filter 12 are used.
(For example, a filter formed of Kapton (trade name) manufactured by DuPont), and X-rays having a peak at a wavelength of 5 Å are exposed to the exposure chamber 1.
3 SR light source 10, beryllium filter 1
1 and the polyimide filter 12 constitute an X-ray source 14.

The sample holder 1 is placed in the exposure chamber 13.
5 is disposed, the sample 16 is composed of a substrate 16a and a P laminated on the substrate 16a.
And a resist 16b (material) having a predetermined thickness made of MMA. On the side of the sample 16 on the sample holder 15, a first moving means 17 is provided.
The mask holder 18 is mounted on the mask 7. An X-ray mask 20 is arranged on the mask holder 18 so as to face the substrate 16. The mask holder 18 has a hole 18a for transmitting X-rays.

The first moving means 17 comprises an X-axis direction moving member 17a for moving the mask holder 18 in the X-axis direction (left-right direction in FIG. 2) with respect to the sample holder 15, and the mask holder 18 with respect to the sample holder 15. In the Y-axis direction (FIG. 2)
Y-direction moving member 17 for moving in the direction perpendicular to the paper surface of FIG.
b. X-ray mask 20 and first moving means 17
Constitutes the control means S.

The sample holder 15 is movably supported with respect to the X-ray source 14 by a second moving means 21 disposed below the sample holder 15. The second moving means 21 is an X-axis direction moving member 2 for moving the sample holder 15, in other words, the substrate 16 and the X-ray mask 20 in the X-axis direction with respect to the X-ray source 14.
1a, and a Y-axis direction moving member 21b for moving the sample holder 15 in the Y-axis direction with respect to the X-ray source 14.

An X-ray source 14 applies X-rays to a resist 16b (PMMA), which is a material to be processed, formed on the substrate 16a.
The reaction upon irradiation with radiation is described as follows. First, the inner core electrons of the PMMA molecule are ionized mainly by the photoelectric effect by the X-ray irradiation, and at the same time, the outer core electrons are emitted by the Auger effect. Subsequently, these secondary and tertiary electrons (energy: 10 to 40 eV) excite the electronic state in PMMA and cause ionization or radicalization of PMMA. At this time, the molecular chain of PMMA is cut by the generation of radicals, and the molecular weight decreases in the exposed region.

Therefore, the exposed area is dissolved in the developing solution. Hydrogen is generated when a molecular chain is cut. The minimum exposure energy required to dissolve PMMA largely depends on the molecular weight of PMMA used.
If the exposure energy exceeds the upper limit, the cross-linking reaction cannot be neglected and will not be dissolved in the developer, or the structure of the PMMA will be destroyed by damage caused by the generated hydrogen gas. Therefore, P
The exposure energy on the bottom surface of the MMA must be lower than the lower limit, and the exposure energy on the surface of the PMMA must be lower than the upper limit.
The shorter the X-ray wavelength, the greater the penetration depth into PMMA, and the greater the maximum depth that can be processed.

The transmission distance in the PMMA varies depending on the wavelength, and the processing depth is determined, and at the same time, the minimum size (resolution) that can be formed. Factors that determine the resolution in X-ray exposure are Fresnel diffraction and "fogging" due to photoelectrons generated in the resist. As the X-ray wavelength decreases, the effect of Fresnel diffraction decreases, but the effect of "fog" increases. As a result of considering these two factors, the optimum X-ray wavelength used in the 0.2 μm LSI process is 10 angstroms. On the other hand, as the X-ray wavelength used in PMMA processing such as LIGA, a short wavelength of 2 to 5 angstroms having a large penetration depth into the resist is used.

The LIGA beamline is designed in consideration of the above points. The main purpose of the X-ray exposure technology applied to the LSI process is to improve the resolution by shortening the exposure wavelength, whereas in the LIGA process, the depth of penetration into the resist is improved by shortening the exposure wavelength. The two main differences are in the design concept of the beamline.

The curve A1 in FIG. 3 shows the spectrum of the emitted light from the SR light source 10, and the curve A2
12 shows an X-ray spectrum at an incident portion of the exposure chamber 13 after passing through the light source 12. The distance from the SR light source 10 to the sample PMMA is 3 m including the electromagnetic yoke. Between the SR light source 10 and the sample, two types of optical filters of the above-mentioned 200 μm-thick beryllium filter 11 and 50 μm-thick polyimide filter 12 are inserted,
As a result, the long wavelength component contained in the emitted light is cut. 5x line from gate valve to beryllium window
The line from the ultra high vacuum of 10 ^-9 Torr and the beryllium window to the polyimide has a low vacuum of 5 × 10 ^-2 Torr or less. The inside of the exposure chamber 13 is filled with 1 atm of He in order to avoid attenuation of X-rays due to oxygen or nitrogen.

The X-ray irradiation area for PMMA on the substrate 15 is a rectangle having a height of 5 mm and a width of 30 mm. SR
The SR light emitted from the light source 10 is said to be parallel light, but strictly speaking, it is 1 in the direction perpendicular to the storage ring.
It has a spread of about mrad. Therefore, there is an energy distribution in the height direction of the irradiation area, and this energy distribution can be calculated theoretically. In FIG. 4, a curve B1 shows the energy distribution in the height direction of the irradiated X-ray at an energy of 2500 eV, and a curve B2 shows a value obtained by integrating this. The average energy obtained by dividing the integral value of the energy by the height of the irradiation area of 5 mm is about 44% of the peak value.

In this embodiment, in order to average the energy distribution in the irradiation area, the sample 16 and the X-ray mask 20 are moved by the second moving means 21 with respect to the X-ray source 14 in the X-axis direction and the Y-axis direction. To each. By scanning the sample 16 and the X-ray mask 20 in the X-axis direction and the Y-axis direction in this manner, it is possible to perform the exposure of a large area while eliminating the influence of the energy distribution described above.

The actual processing method of the resist 16b will be described below with reference to FIGS. As shown in FIG. 5A which is a plan view and FIG. 5C which is a vertical sectional view, the X-ray mask 20 is formed by laminating an X-ray absorbing film 20b on an X-ray transmitting film 20a. For example, a circular hole 20c having a radius of 25 μm is formed in the center of the absorbing film 20b, and X-rays can be transmitted through the circular hole 20c.

For example, as shown in FIG. 5E which is a vertical sectional view of the sample 16 and FIG. 5F which is a schematic perspective view of only the hole 16c to be formed in the resist 16b, the resist 16b (PMMA) In the case where an inverted truncated cone-shaped hole 16c whose diameter is reduced toward the lower side is provided, the resist 16b
Fig. 5 (d) shows the energy distribution of X-rays applied to
As shown by the polygonal line C, the energy distribution needs to be high at the center of the hole 16c corresponding to the shape of the hole 16c and gradually decrease toward the outer periphery. FIG.
(D) shows the energy distribution of the X-rays in the X-axis direction. However, the energy distribution of the X-rays in the Y-axis direction needs to be the same as that of the polygonal line C.

For example, circle 16 at the upper end of hole 16c
When the radius of d is 37.5 μm and the radius of the circle 16 e at the lower end of the hole 16 c is 12.5 μm, the energy distribution of the X-rays is 1 radius at the center of the X-ray mask 20.
The strongest in the area of 2.5 μm, radius 12.5 μm
Is controlled so that the irradiation energy of X-rays gradually decreases from the region to a region having a radius of 37.5 μm. In order to realize such control, while continuously irradiating X-rays from the X-ray source 14, the X-ray mask 20 shown in the plan view of FIG. 5A is placed on a plane parallel to the surface 16f of the resist 16b. Within the circle having a radius of 12.5 μm.

That is, in FIG. 5A, the X-ray mask 2
0, that is, the center of the circular hole 20c is shown in FIG.
5E, the center E of the resist 16b coincides with the center E of the resist 16b.
As shown in (b), the center D of the X-ray mask 20 is a plane including the X axis and the Y axis, that is, the surface 16f of the resist 16b.
While continuously rotating the entire X-ray mask 20 so as to move on a circumference F having a radius of 12.5 μm around the center E of the resist 16b in a plane parallel to the X-ray mask 20,
The resist 16b is irradiated with X-rays through. Thus, a radius of 12.5 around the center E of the resist 16b is obtained.
X-rays are constantly irradiated within the range of μm, but a radius of 12.
In the range of 5 to 37.5 μm, the X-ray energy distribution can be controlled so that the X-ray irradiation time, that is, the X-ray irradiation energy decreases toward the outer peripheral side.

The X-ray mask 20 on the circumference F as described above
Is rotated by the X-axis direction moving member 1 of the first moving means 17.
7a and the Y-axis direction moving member 17b are simultaneously driven so that the center X of the X-ray mask 20 moves on the circumference F.
This can be realized by continuously controlling the direction and speed of movement of the line mask 20 in the X-axis direction and the Y-axis direction. The circumference F vertically overlaps a circle 16e (see FIG. 6) at the lower end of an inverted truncated conical hole 16c formed in the resist 16b.

As described above, the resist 16b is irradiated with X-rays through the X-ray mask 20 while circularly moving the X-ray mask 20 in a plane parallel to the surface 16f of the resist 16b. , The processing depth increases with an increase in X-ray irradiation energy. Accordingly, in the resist 16b, an inverted truncated cone-shaped microstructure (hole 16c) having a radius of 12.5 μm at the lower bottom (hole 16e) and a radius of 37.5 μm at the upper bottom (hole 16d) corresponding to the irradiation energy distribution. It is formed.

If a large number of circular holes 20c (X-ray transmission patterns) having a radius of 25 μm are formed in an array on the X-ray mask 20 at a pitch of 200 μm, for example, an inverted truncated cone-shaped fine pattern on the resist 16b is formed. A large number of structures (holes 16c) are formed in an array with a pitch of 200 μm, and can be used for batch processing.

X-axis direction moving member 21 of second moving means 21
a and the Y-axis direction moving member 21b
It is used to scan the substrate 16a to uniformly irradiate the entire surface of the upper resist 16b with X-rays. The scan speed of the substrate 16a is sufficiently lower than the scan speed of the X-ray mask 20 by the first moving means 17. For example, the scan speed of the substrate 16a is preferably 1 mm / sec or less, and the scan speed of the X-ray mask 20 is preferably 10 mm / sec or more.

Thus, scanning of the substrate 16a and X
The interference with the scanning of the line mask 20 is eliminated, and the substrate 16a
It is possible to perform uniform processing on the resist 16b in each part of the above. Also, by constantly monitoring the X-ray intensity, the scan speed of the substrate 16a and the scan speed of the X-ray mask 20 may be controlled so that the X-ray energy applied to a unit area per unit time is constant. This is effective for performing uniform processing on each part of the substrate 16a.

Contrary to the above, by making the scan speed of the substrate 16a sufficiently higher than the scan speed of the X-ray mask 20, it is also possible to produce the effect of performing uniform processing on each part of the substrate 16a. . But,
The load of the second moving means 22 for scanning the substrate 16a;
Compared with the load of the first moving means 17 for scanning the X-ray mask 20, the load of the second moving means 21 for scanning the substrate 16a is larger. Going faster than the scan speed is not a desirable method. Note that the contents related to these scans are the same in other embodiments of the present invention described below, and redundant description will be omitted.

Next, a second embodiment of the present invention will be described. FIG. 7 shows a processing apparatus according to the second embodiment.
The X-ray source 14 is configured in the same manner as in the first embodiment, and the second moving means 21 and the sample holder 15 in the exposure chamber 13 are also configured in the same manner as in the first embodiment.
On the sample holder 15, a sample 22 composed of a substrate 22a and a resist 22b made of PMMA is arranged.

In the second embodiment, two upper and lower X-ray masks 23 and 24 are used, and two mask holders 25 and 26 for holding the respective X-ray masks 23 are provided. These mask holders 25 and 26 are provided with holes 25a and 26a for transmitting X-rays, respectively. The first moving means 27 is composed of two X-axis direction moving members 27a and 27b for moving the respective mask holders 25 and 26 in the X-axis direction (left-right direction in FIG. 7). Here, the control means S includes X-ray masks 23 and 24 and a first moving means 27.

As shown in FIGS. 8A to 8C, the X-ray masks 23 and 24 are respectively provided with X-ray transmission films 23a and 24a and X-ray transmission films 23a and 24a.
It is formed by laminating the line absorbing films 23b and 24b. Square holes 23 having a diagonal length of 50 μm are formed in the X-ray absorbing films 23b and 24b.
c and 24c are formed, and X-rays are transmitted through the overlapping portions of the holes 23c and 24c of the two X-ray masks 23 and 24.

At the time of X-ray irradiation for processing the resist 22b, first, two X-ray masks 23 and 24 are applied as shown in FIG.
The X-ray mask 23 starts from a position where one vertex G and H overlap each other as shown in FIG.
To the left side of FIGS. 8A and 8B along the X-axis direction by 25 μm.
While being moved, the X-ray mask 24 moves to the right in FIGS. 8A and 8C along the X-axis direction at the same speed as the X-ray mask 23.
The X-ray masks 23 and 24 are finally moved so that the X-ray masks 23 and 24 overlap each other at a position indicated by a chain line in FIG.

The resist 2 obtained by such irradiation
The energy distribution of the X-rays in the X-axis direction on 2b is the strongest at the center I of the X-ray masks 23 and 24 at the final position as shown by the broken line J in FIG. The irradiation energy is reduced.
Further, the energy distribution of the X-rays in the Y-axis direction is the same as that of the polygonal line J.

Therefore, when the resist 22b is treated with a developing solution, the processing depth becomes deeper as the irradiation energy increases, so that the resist 22b has an inverted quadrangular pyramid with a diagonal length of 50 μm at the bottom corresponding to the irradiation energy distribution. Is formed (a hole 22c). The size of the holes 23c and 24c of the two X-ray masks 23 and 24 may not be the same as long as the diagonal length is 50 μm or more. Needless to say, the masks 23 and 24 need only be moved.

The X-ray transmission pattern (holes 23c, 24
c) on the X-ray masks 23 and 24, for example, at a pitch of 20
If formed in an array of 0 μm, a plurality of inverted quadrangular pyramid-shaped microstructures (holes 22 c) are formed on the resist 22 b in an array with a pitch of 200 μm, and it is possible to cope with batch processing.

Next, a third embodiment of the present invention will be described. Although the configuration itself of the processing apparatus is the same as that of the second embodiment shown in FIG. 7, the X-ray mask 23 of the second embodiment has
Instead of 24, two X-ray masks 28 and 29 shown in FIGS. 9A to 9C are used, and a resist 30 of a sample 30 including a substrate 30a and a resist 30b made of PMMA is used.
Irradiate X-ray on b.

The two X-ray masks 28 and 29 have the same configuration as each other, and are formed by laminating X-ray transmission films 28b and 29b on X-ray absorption films 28a and 29a.
b and 29b have a long Y-axis direction and a width of 20 μm in the X-axis direction.
Rectangular holes 28c, 29c are formed.
X-rays are transmitted through the overlapping portion 9c.

Here, the pitch is 20 μm, 15 μm,
Grating 3 having a slope that changes sequentially to 10 μm
The case where 0c, 30d, and 30e are formed on the resist 30b will be described. As shown in FIGS. 10A and 10B, first, in the first step, starting from the position where the X-ray masks 28 and 29 overlap each other, the X-ray mask 28 is
While holding at the position of (a), only the X-ray mask 29 is linearly moved by 20 μm to the left side of the X axis from the position of FIG. 10 (b) to the position of FIG. 10 (c).

As is apparent from FIGS. 10A and 10C, finally, only the long sides of the X-ray masks 28 and 29 overlap each other. Resist 3 obtained by such X-ray irradiation
The X-ray energy distribution on 0b gradually increases toward the left side in the X-axis direction, as indicated by the polygonal line K1 in FIG.

Next, in the second step, the X-ray mask 28 is used.
In a short time to the left side of the X-axis to the position of FIG.
Move m. Subsequently, the X-ray mask 28 is changed to the state shown in FIG.
While holding at the position shown in FIG. 10, only the X-ray mask 29 is linearly moved by 15 μm from the position shown in FIG. 10F to the position shown in FIG. 10G to the left in the X-axis direction. As is clear from FIGS. 10E and 10G, finally, only the long sides of the X-ray masks 28 and 29 overlap each other. Obtained resist 30b
The above X-axis energy distribution is shown by the broken line K2 in FIG.
It becomes as shown by.

Subsequently, in the third step, the X-ray mask 28 is moved to the left side of the X-axis to the position shown in FIG.
Move by 0 μm. Next, the X-ray mask 28 is
While holding at the position (i), only the X-ray mask 29 is shown in FIG.
It is moved linearly by 10 μm to the left of the X axis from the position of 0 (j) to the position of FIG. 10 (k). As apparent from FIGS. 10 (i) and 10 (k), only the long sides of the X-ray masks 28 and 29 eventually overlap. Obtained resist 30b
The above X-ray energy distribution is shown by the broken line K3 in FIG.
It becomes as shown by.

After the X-ray irradiation in the first to third steps as described above, the resist 30b is developed.
As shown in (e), the pitch is 2 on the resist 30b.
Gratings 30c to 30e having slopes sequentially changing to 0 μm, 15 μm, and 10 μm are formed. The X-ray transmission patterns (holes 28) of the two X-ray masks 28 and 29
It is needless to say that the sizes of c and 29c) may not be the same size as long as the width is 20 μm or more, and it is only necessary that the initially overlapping length in each step is equal to the pitch. Also, if a large number of X-ray transmission patterns are formed on the X-ray masks 28 and 29, for example, at a pitch of 200 μm, many fine structures of the gratings 30c to 30e on the resist 30b are formed at a pitch of 200 μm, which is compatible with batch processing. It is possible.

Next, a fourth embodiment of the present invention will be described. In each of the above embodiments, one or more X-ray masks are moved to continuously change the X-ray irradiation energy distribution. However, in the fourth embodiment, the deposition of the X-ray absorbing material is performed. Alternatively, the case where the X-ray transmission pattern is changed by dissolution will be described.

As shown in FIG. 11, the X-ray mask 32
On a substrate 32a made of a line transmitting material, for example, a polyimide film having a thickness of about 50 μm,
A plurality of striped copper electrodes 32b (X-ray absorbing material) having a thickness of 1 μm and a thickness of 1 μm are formed in parallel with each other. Two such X-ray masks 32 are opposed to each other with a gap of about 20 μm while the longitudinal directions of the copper electrodes 32 b are orthogonal to each other, and a plating solution (not shown) containing copper ions is sealed between the two X-ray masks 32. And seal.

In the above configuration, a sample (not shown) is irradiated with X-rays from an X-ray source (not shown) through two X-ray masks 32 containing the plating solution. When no voltage is applied between the copper electrodes 32b of the mask 32, an equilibrium is established between the copper electrodes 32b and the copper ions in the plating solution, and no change occurs.

On the other hand, when one of the copper electrodes 32b on the two X-ray masks 32 is selected and a voltage is applied from the power supply 33 as shown in FIG.
The copper 34 is deposited on the minus electrode at the intersection position of. When the thickness of the deposited copper 34 is about 10 μm, X-rays having a strength capable of processing PMMA to 100 μm can be sufficiently absorbed.

Copper electrode 32b for applying voltage from power supply 33
Is controlled by a computer, the pattern drawn by the copper 34 deposited on the minus electrode with time can be freely controlled, and the pattern that transmits X-rays can be varied. The same effect can be obtained by using a gold electrode instead of the copper electrode 32b. Also,
It is also possible to change the X-ray transmission pattern by previously depositing a copper pattern on the entire surface of the striped copper electrode 32b and dissolving the copper by applying an external voltage.

Next, a fifth embodiment of the present invention will be described. As shown in FIGS. 13 and 14, the X-ray mask 35 has a plurality of micro-shutters 35b arranged in an array on a substrate 35a made of an X-ray transmitting material, for example, a polyimide film having a thickness of about 50 μm. Each micro shutter 35b is made of, for example, a flat square gold having a thickness of 2 μm and a side of 10 μm. Each micro shutter 35b
Are pivotally supported at two opposing corners by a hinge 35c, and the micro shutter 35b and the hinge 35c are supported on the substrate 35a by a pole 35d.

As shown in FIGS. 13 and 14, when each micro shutter 35b takes a horizontal position, X-rays are absorbed by the micro shutter 35b and do not pass therethrough.
As shown in FIG. 15, when the micro-shutter 35b takes a vertical posture due to the 90 ° twisting action of the hinge 35c, X-rays can be transmitted. Each micro shutter 35
An address is given to b in the same manner as in a normal semiconductor memory, and the blocking and transmission of the micro shutter 35b can be controlled in any combination by a control signal from a control unit (not shown).

In each of the above embodiments, PMMA is used as the resist. However, any other suitable synthetic resin or the like can be used as the resist. Also, the first to third embodiments show examples in which the X-ray mask is moved to change the X-ray transmission pattern. It is needless to say that the processing using is possible. In addition, the second
In the third embodiment, each of the two X-ray masks is
Although the X-ray transmission pattern is changed by moving only in the axial direction, two X-ray masks may be moved in the X and Y axis directions, respectively, if necessary. Further, if necessary, three or more X-ray masks can be used.

[0067]

According to the method for processing a material using X-ray irradiation according to the first aspect of the present invention, the energy distribution of the X-ray in a plane parallel to the surface of the material to be processed is continuously changed. This makes it possible to process the material three-dimensionally. For example, it is also possible to perform a hole processing or the like having a shape in which the inclination direction changes continuously or stepwise, such as a cone or a pyramid. Will be possible.

According to the apparatus for processing a material using X-ray irradiation according to the second aspect of the present invention, the control for controlling the energy distribution of the X-ray in a plane parallel to the surface of the material to be continuously changed. Since it has a means, it is possible to control the depth of processing in each part of the material, for example, a hole having a shape in which the inclination direction changes continuously or stepwise, such as a cone or a pyramid in the material. Processing can be performed.

According to the apparatus for processing a material using X-ray irradiation according to the third aspect of the present invention, the X-ray source arranged between the X-ray source and the material is used.
By changing the X-ray transmission pattern with a line mask,
By continuously changing the energy distribution of the X-rays, it is possible to control the processing depth in each part of the material. Thus, there is an advantage that the energy distribution of X-ray irradiation on the surface of the material can be controlled without controlling the X-ray irradiation energy from the X-ray source.

According to the apparatus for processing a material using X-ray irradiation according to the fourth aspect of the present invention, the X-ray mask is moved by the first moving means so that the X-ray transmission pattern is varied to change each part of the material. Can control the depth of processing. This makes it possible to control the processing depth of each part of the material with a relatively simple and inexpensive configuration without changing the X-ray transmission pattern of the X-ray mask itself.

According to the apparatus for processing a material using X-ray irradiation according to the fifth aspect of the present invention, the X-ray mask is moved by the first moving means to one or more of the material within a plane substantially parallel to the surface of the material. Since it is relatively moved in the axial direction, there is an advantage that it is possible to easily and inexpensively drill a hole having a relatively complicated shape such as a cone or a pyramid.

In the apparatus for processing a material using X-ray irradiation according to a sixth aspect of the present invention, the material and the X-ray mask are moved by a second moving means in a plane substantially parallel to the surface of the material with respect to the X-ray source. At 1
Alternatively, since the material is relatively moved in a plurality of axial directions, there is an advantage that the entire surface of the material can be irradiated with X-rays to reliably process each part of the material.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between X-ray irradiation energy for a material and processing depth.

FIG. 2 is an explanatory view showing a processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a graph showing an X-ray spectrum at an entrance of an exposure chamber after passing through an SR light source and a filter in the processing apparatus.

FIG. 4 is a graph showing an energy distribution in the height direction of irradiated X-rays at an energy of 2500 eV and an integrated value thereof.

FIG. 5 is an explanatory diagram showing a configuration of an X-ray mask and a sample according to the first embodiment.

FIG. 6 is a plan view showing a sample according to the first embodiment.

FIG. 7 is an explanatory view showing a processing apparatus according to a second embodiment.

FIG. 8 is an explanatory diagram showing a configuration of an X-ray mask and a sample according to the second embodiment.

FIG. 9 is an explanatory diagram showing a configuration of an X-ray mask and a sample according to a third embodiment.

FIG. 10 is an explanatory diagram showing a procedure for forming a grating on a sample in the third embodiment.

FIG. 11 is a perspective view showing an X-ray mask according to a fourth embodiment.

FIG. 12 is a perspective explanatory view showing a state where a current is applied between electrodes of the X-ray mask of FIG. 11;

FIG. 13 is a plan view showing an X-ray mask according to a fifth embodiment.

FIG. 14 is a side view showing the X-ray mask of FIG.

FIG. 15 is a side view showing a state where a shutter of the X-ray mask of FIG. 14 is opened.

FIG. 16 is an explanatory sectional view for explaining a processing procedure by a conventional LIGA.

[Explanation of symbols]

14 X-ray source 16b, 22b, 30b Resist (material) 17, 27 First moving means 20, 23, 24, 28, 29, 32, 35 X-ray mask 21 Second moving means S Control means

Claims (6)

[Claims] 1. A method of processing a material using X-ray irradiation, which removes the material by irradiating the material with X-rays or changes the physical and chemical properties of the material, comprising the steps of: By controlling the energy distribution of the X-rays in a parallel plane so as to change continuously, processing of a depth corresponding to the energy distribution of the X-rays is performed in each part of the material. A method for processing materials using X-ray irradiation. 2. An apparatus for processing a material using X-ray irradiation, which removes the material by irradiating the material with X-rays from an X-ray source or changes the physical and chemical properties of the material, An apparatus for processing a material using X-ray irradiation, comprising control means for controlling the energy distribution of the X-ray in a plane parallel to the surface of the material so as to continuously change. 3. The control means is disposed between the X-ray source and the material, and is capable of changing an X-ray transmission pattern.
The apparatus for processing a material using X-ray irradiation according to claim 2, further comprising a line mask. 4. The apparatus according to claim 1, wherein the control unit includes one or more X-ray masks disposed between the X-ray source and the material, and a control unit that moves the X-ray mask relative to the material. 1
3. The X according to claim 2, further comprising moving means.
Material processing equipment using X-ray irradiation. 5. The method according to claim 1, wherein the first moving unit is configured to move the X-ray mask with respect to the material in a plane substantially parallel to the surface of the material.
The apparatus for processing a material using X-ray irradiation according to claim 4, wherein the apparatus is moved relatively in a plurality of axial directions. 6. A moving means for moving the material and the X-ray mask relative to the X-ray source in one or more axes in a plane substantially parallel to the surface of the material. An apparatus for processing a material using X-ray irradiation according to any one of claims 2 to 5.