JP2002151395A - Method and apparatus for processing material using x- rays - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for processing a material using X-rays, capable of easily processing a three-dimensional shape which includes lateral asymmetry, an arbitrary curved shape or the like. SOLUTION: The method for processing the material using X-rays comprises the steps of irradiating the material with X-rays via an X-ray mask, while relatively moving the material 2 capable of being processed at a depth, in response to X-ray irradiation amount and the X-ray mask 3, and processing parts of the material to variable depths. The method further comprises the steps of disposing the mask having an X-ray absorption layer 3b of the shape, corresponding to a sectional shape in a prescribed direction of the material, after processing at a prescribed interval from the surface of the material, and irradiating the X-rays to the material via the mask, while relatively moving the mask in a direction perpendicular to the section of the material in the prescribed direction to process the material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing various parts of a material at a variable depth by irradiating a material which can be processed at a depth corresponding to the dose of X-rays through an X-ray mask. The present invention relates to a method and an apparatus for processing a material using X-rays.

[0002]

2. Description of the Related Art As the integration of electronics and mechanical parts, such as information communication equipment and micromachines, progresses, not only electronic parts but also mechanical parts are required to be minutely and precisely processed. Conventionally, as a method suitable for such high-precision processing, a method called LIGA is known. LIGA (Lithographie Galvanoformung Abformun
g) is a method proposed in Germany, whose name comes from the German acronym lithography, electroplating and molding.

In this LIGA, first, as shown in FIG. 6A, a resist material 2 made of PMMA (polymethyl methacrylate) or the like is formed on a substrate 1 made of a metal or the like, and an X-ray transmission layer is formed. X-ray absorbing layer 3 of desired shape on 3a
The resist material 2 is irradiated with X-rays from a synchrotron light source (not shown) or the like via the X-ray mask 3 in which b is formed.

As shown in FIG. 7 (a) with the thickness of the X-ray mask 3, the X-ray absorbing layer 3 is provided on the back side of the X-ray transmitting layer 3a.
The X-rays are absorbed and do not transmit in the region where the X-ray absorption layer 3b is formed, but the X-rays are transmitted in the region where the X-ray absorption layer 3b is not formed. The molecular chains are cut and the molecular weight decreases.

Therefore, when the resist material 2 is developed with a predetermined developing solution after the exposure is completed, the resist material 2 is removed in the exposed area to form a concave portion 2a. The depth of the concave portion 2a, that is, the processing depth is determined by the integrated irradiation amount of X-rays.
Specifically, in the case of the resist material 2 made of PMMA, as shown in FIG. 7B, when the required processing depth is relatively small, the processing depth is substantially proportional to the integrated irradiation amount. As the required processing depth increases, the rate of increase of the processing depth according to the integrated irradiation amount decreases.

Returning to FIG. 6, when the X-ray mask 3 shown in FIG. 6A is used to irradiate a sufficient amount of X-rays to remove the entire resist material 2 in the thickness direction, As shown in b), the resist material 2 is formed in the region where the X-ray absorption layer 3b is formed.
Is approximately 0%, while in the region where the X-ray absorption layer 3b is not formed, the integrated radiation amount is approximately 1%.
00%.

As a result, as shown in FIG.
Substantially all of the resist material 2 remains in the region where the X-ray absorption layer 3b is formed, whereas substantially the entire resist material 2 is removed in the region where the X-ray absorption layer 3b is not formed. The integrated X-ray dose is a value calculated by assuming that the dose required to completely remove the resist material 2 in the thickness direction is 100%.

After the resist material 2 is partially removed as described above, although not shown, the gap between the remaining resist materials 2 is filled with a metal such as Ni by electroplating, and then the resist material 2 is removed. Thereby, a metal structure having a predetermined uneven shape can be obtained.

Using this metal structure as a mold, a plastic or ceramic micropart can be produced,
The metal structure itself can be used as a micro component. According to the above-mentioned LIGA, the aspect ratio (height dimension / width dimension) of the remaining resist material 2 in FIG. 6 (c), that is, the aspect ratio of the final product may be about several tens to 100 or more. it can.

[0010]

However, in the above-mentioned method, the remaining resist material 2 shown in FIG. 6 (c), and therefore, a limitation that only uniform processing can be performed in the height direction (processing depth direction) of the final product. There is. That is, the horizontal cross-sectional area (cross-sectional area parallel to the surface of the substrate 1) of the remaining resist material 2 is constant irrespective of the height position of the resist material 2, but this is due to the X-ray integration in FIG. The dose distribution is approximately 0% at the position where the X-ray absorption layer 3b exists, and approximately 100 at the position where the X-ray absorption layer 3b does not exist.
%, And there is no intermediate value.

Therefore, for example, as shown in FIG.
When the X-ray mask 3 having the circular X-ray absorption layer 3b is relatively moved with respect to the resist material 2 and the resist material 2 is irradiated with X-rays through the X-ray mask 3, the same effect can be obtained. As shown in FIG. 1C, for example, the shape of the resist material 2 after development can be a truncated cone.

For example, as shown by an arrow C, the relative movement path of one corner point 3c of the X-ray mask 3 in FIG. By continuously moving at a constant angular velocity so as to draw a circle having a radius smaller than the radius of the layer 3b, the region where the X-rays are always blocked by the X-ray absorption layer 3b as shown in FIG. This is because a region where the integrated amount of X-ray irradiation continuously changes is provided between the region irradiated with X-rays.

However, the X-ray mask 3 shown in FIG.
In the processing method of exposing while moving the surface, processing of a simple three-dimensional shape such as a truncated cone can be performed relatively easily. However, processing of a three-dimensional shape including an asymmetrical three-dimensional shape or an arbitrary curved surface shape is not possible. There was a restriction that it was difficult.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of processing a material using X-rays which can easily process a three-dimensional shape including left-right asymmetry and an arbitrary curved surface shape, and the like. It is intended to provide a device. Therefore, in the method of processing a material using X-rays according to claim 1 of the present invention, the X-ray mask is moved while relatively moving a material that can be processed at a depth corresponding to the X-ray irradiation amount and the X-ray mask. In a method of processing each part of the material at a variable depth by irradiating the material with X-rays through a mask, an X-ray having an X-ray absorbing layer having a shape corresponding to a cross-sectional shape in a predetermined direction of the processed material is provided. The X-ray mask is disposed at a predetermined interval between the X-ray mask and the surface of the material, and the X-ray mask is relatively moved in a direction orthogonal to a cross section of the material in a predetermined direction while the X-ray mask is interposed therebetween. The material is processed by irradiating the material with X-rays.

According to a second aspect of the present invention, there is provided a method for processing a material using X-rays, the method comprising the steps of providing one or more X-ray absorbing layers each having a shape corresponding to a cross-sectional shape of the processed material in a plurality of directions. The X-ray mask is used to irradiate the material with X-rays through the X-ray mask while relatively moving each corresponding X-ray mask in a direction orthogonal to the individual cross section of the material. Things.

Here, one or a plurality of X-ray masks are used because, when the cross-sectional shapes of the above materials in the plurality of directions are equal to each other, the same X-ray mask can be used in the plurality of directions. When the cross-sectional shapes in the directions are different from each other, the purpose is that X-ray masks having different X-ray absorbing layers in each direction can be used.

According to a third aspect of the present invention, there is provided a method of processing a material using X-rays according to the first or second aspect, wherein after processing the material in advance, a desired position of the processed material and a desired position of the X-ray mask are obtained. Are positioned so that they face each other, and the X-ray mask and the material are moved relative to each other.
The material is processed by irradiating the material with X-rays through a line mask.

According to a fourth aspect of the present invention, there is provided an apparatus for processing a material using X-rays, wherein the X-ray mask and a material which can be processed at a depth corresponding to the X-ray irradiation amount are irradiated with the X-rays through the X-ray mask. In the apparatus for processing a material using X-rays, comprising an X-ray irradiating section to be driven and a drive section for relatively moving the X-ray mask with respect to the material, the X-ray mask is provided in a predetermined direction of the processed material. An X-ray absorption layer having a shape corresponding to a cross-sectional shape is provided, and the driving unit relatively moves the X-ray mask in a direction orthogonal to a cross section of the material in a predetermined direction.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1A, a processing apparatus using X-rays includes an X-ray mask 3 fixedly arranged at a predetermined position and a resist material 2 (material) such as PMMA with a substrate 1 made of metal or the like. And a drive unit (not shown) that reciprocates the table 4 with respect to the X-ray mask 3 at a constant speed in the Y-axis direction, for example. It is arranged in an exposure chamber (not shown) filled with gas (about 1 atm).

The processing apparatus has an X-ray irradiator (not shown) formed of a synchrotron radiation device or the like outside the exposure chamber. X-rays are incident from the X-ray irradiator into the exposure chamber. Irradiation is performed on the resist material 2 via the mask 3. In the figure, X0, Y0, and Z0 indicate the sizes of the resist material 2 in the X-axis, Y-axis, and Z-axis directions, respectively. As is apparent from FIG.
The size of the line mask 3 in the X-axis and Y-axis directions is
Are set to be equal to the sizes X0 and Y0 in the X-axis and Y-axis directions, respectively.

The X-rays from the X-ray irradiator are applied to an X-ray mask 3
Is irradiated only in the range where the X-ray mask 3 is arranged, and when the resist material 2 protrudes from the range where the X-ray mask 3 overlaps with the movement of the table 4, X The line is not irradiated.

For example, when it is desired to process the resist material 2 into a shape as shown in FIG. 1 (c), as shown in FIG. 1 (a), a cross section of the resist material 2 after the above processing is formed on an X-ray mask 3. An X-ray absorption layer 3b (shown with hatching for convenience) having a shape substantially equal to the shape is formed in advance.

As shown in FIG. 3, in this embodiment,
While the table 4 is reciprocated at a constant speed in the Y-axis direction (see arrow M), X is applied to the resist material 2 through the X-ray mask 3.
Expose the line.

In this case, the table 4 includes an I position where the front end position 2a of the resist material 2 in the Y-axis direction is located closer to the rear end position 3d of the X-ray mask 3 in the Y axis direction, and a Y position of the resist material 2. The rear end position 2b in the axial direction is moved between the position II and the front end position 3c of the X-ray mask 3 in the Y axis direction. That is, during one forward movement (rightward movement in FIG. 3) or backward movement (leftward movement in FIG. 3) of the table 4, the entire region of the resist material 2 passes under the X-ray mask 3. Set the movement range.

As described above, when the resist material 2 is irradiated with X-rays while the table 4 is moved at a constant speed in the Y-axis direction, the integrated X-ray irradiation dose in each part of the resist material 2 in the X-axis direction is as shown in FIG. The distribution is as shown by the curve f 'in the middle (b).

That is, in FIG. 2A, the curve shape formed by the contour of the X-ray absorption layer 3b (the contour of the portion not in contact with the rear end 3d) in the X-ray mask 3 is represented by a predetermined function f. Then, the curve f ′ in FIG.
Is inverted to (-), and the function after the inversion is translated from the (-) side to the (+) side.

More specifically, in FIG. 2A, the X coordinate is a function f at each point of X1, X2 and X3.
(Y coordinate) are Y1, Y2, and Y3, respectively. Considering the position where the X coordinate on the resist material 2 is X1,
Since the length of the entire X-ray mask 3 in the Y-axis direction is Y0, the length of the X-ray absorption layer 3b is Y1 and the moving speed of the table 4 is constant, the X-ray irradiation is performed. The probability that X-rays will be shielded during the period is Y1 / Y0, while the X coordinate is X1
The probability of X-ray irradiation at the position (the actual X-ray irradiation time / the total irradiation time at the position where the X coordinate is X1) is (Y0-Y1).
/ Y0 = α1.

Similarly, the probability of irradiating an X-ray on the position of the resist material 2 where the X coordinate is X2 is (Y0−Y2) / Y0 = α.
It becomes 2. At the position where the X coordinate is X3, Y3 = Y0, and since the X-ray is always blocked, the probability of X-ray irradiation is zero.

Therefore, as described above, the curve f 'showing the change in the X-ray integrated irradiation dose in the X-axis direction is obtained by inverting the function f up and down. When the X coordinate on the resist material 2 is equal, the integrated X-ray dose is constant regardless of the Y coordinate, that is, the position of the resist material 2 in the Y-axis direction. This is because, in FIG. 3, during one forward or backward movement of the table 4, the entire area of the resist material 2 in the Y-axis direction passes below the entire area of the X-ray mask 3 in the Y-axis direction.

As a result, after exposure while moving the table 4, the resist was developed by using an appropriate developing solution such as a mixed aqueous solution of 2- (2-butoxyethoxy) ethanol, morpholine and 2-aminoethanol. The material 2 is processed into a shape as shown in FIG. That is, the cross-sectional shape of the resist material 2 in the XZ plane is constant regardless of the Y coordinate and becomes as shown in FIG. 2B, and the X-ray absorption of the X-ray mask 3 in the XY plane in FIG. Layer 3b
Is mapped on the XZ plane of the resist material 2.

However, the size Y0 of the X-ray mask 3 in the Y-axis direction
When the size Z0 of the resist material 2 in the Z-axis direction is different from that of the resist material 2, the cross-sectional shape of the resist material 2 in the XZ plane is a state in which the shape of the X-ray absorbing layer 3b is enlarged or reduced in the vertical direction by Z0 / Y0 times (X-axis). The direction is the same).

In other words, when the X-ray mask 3 is created,
Based on the size Z0 (thickness) of the resist material 2 in the Z-axis direction and the size Y0 of the X-ray mask 3 in the Y-axis direction, the cross-sectional shape of the processed resist material 2 is vertically enlarged or reduced by Y0 / Z0 times. It is necessary to make the shape (the same magnification in the X-axis direction) the shape of the X-ray absorption layer 3b.

In this specification, as described above, the cross-sectional shape of the processed resist material 2 is enlarged or reduced in the vertical direction (the same magnification in the X-axis direction) as the shape of the X-ray absorbing layer 3b. Including this case, the cross-sectional shape of the processed resist material 2 is substantially equal to the shape of the X-ray absorbing layer 3b.

As shown in FIG. 7B, when PMMA is used as the resist material 2, the processing depth is several hundreds.
In the range of about μm or less, since the integrated X-ray irradiation amount and the processing depth are substantially proportional, the maximum processing depth, that is, the resist material 2
When the thickness Z0 is about several hundred μm or less, it is only necessary to make the shape of the X-ray absorbing layer 3b of the X-ray mask 3 substantially equal to the cross-sectional shape of the processed resist material 2 as described above.

On the other hand, when the thickness Z0 of the resist material 2 exceeds about several hundred μm, as apparent from FIG. 7B, the integrated X-ray irradiation amount and the processing depth are not proportional. It is necessary to make the shape of the X-ray absorption layer 3b different from the cross-sectional shape of the processed resist material 2 according to the processing depth. Specifically, in FIG. 2A, the curve f may be shifted downward in an area where the machining depth is large, that is, in an area where the Y coordinate is small.

As described above, in the present embodiment, the shape of the X-ray absorption layer 3b in the X-ray mask 3 can be substantially transferred to the cross-sectional shape of the processed resist material 2. An asymmetric shape or an arbitrary curved shape can be easily achieved.

Next, another embodiment of the present invention will be described. In the above-described embodiment, the X-ray mask 3 is exposed and developed while moving the X-ray mask 3 at a constant speed in only one direction of the resist material 2. By performing exposure using the X-ray mask 3, the resist material 2 can be processed into a more complicated three-dimensional shape.

For example, when the X-ray mask 3 having the X-ray absorbing layer 3b having the shape shown in FIG. 4A is exposed and developed while relatively moving the resist material 2 in one direction in the same manner as described above, As a result of transferring the shape of the X-ray absorption layer 3b to the resist material 2, the resist material 2 is processed into a shape as shown in FIG.

Subsequently, the resist material 2 shown in FIG.
When the resist material 2 is rotated by 0 ° and exposed and developed again while relatively moving the same X-ray mask 3 in the same direction as the resist material 2 after the rotation, the resist material 2 becomes as shown in FIG.
It is processed into the shape as shown in FIG.

In this case, the resist material 2 at the far right end of each of the plurality of substantially square pyramid-shaped resist materials 2 arranged vertically and horizontally on the substrate 1 is connected to a vertical plane parallel to the X axis including its apex 2c and the vertical plane. The cross-sectional shape of each cross section cut along a vertical plane parallel to the Y axis including the vertex 2c is substantially equal to the shape of the X-ray absorption layer 3b.

In the above embodiment, the same X-ray mask 3 is exposed and developed while being relatively moved with respect to the resist material 2 in two directions perpendicular to each other.
In addition, exposure may be performed in two directions orthogonal to each other using two X-ray masks 3 having different shapes of the X-ray absorption layer 3b. In this case, a cross section of the processed resist material 2 in two directions is used. The shapes will be different from each other.

FIG. 5 shows still another embodiment. As shown in FIG. 2A, predetermined processing is performed on the resist material 2 in advance (here, processing in which a plurality of holes 2d penetrating in the thickness direction of the resist material 2 is formed at predetermined intervals W in the vertical and horizontal directions).
After that, the X-ray mask 3 having the X-ray absorption layer 3b having the shape as shown in FIG.

The interval W between the repetitive patterns in the X-ray absorbing layer 3b is equal to the interval W between the holes 2d in the resist material 2.
The X-ray mask 3 and the resist material 2 are arranged such that the connection line L1 at the center of the adjacent hole 2d and the center line L1 of the repeating pattern of the X-ray absorption layer 3b face each other.
And positioning. Then, the connection line L1 and the center line L
When the resist material 2 is exposed through the X-ray mask 3 while moving the X-ray mask 3 in the direction of the center line L2 while the resist material 2 is matched, the resist material 2 has the shape shown in FIG. Become.

Thereafter, the resist material 2 shown in FIG.
After rotating by 0 °, the connecting line at the center of the hole 2d adjacent to the center line L2 of the repeating pattern of the X-ray absorbing layer 3b again (however, a direction orthogonal to the connecting line L1 in FIG. 5A) When the X-ray mask 3 is moved in the direction of the center line L2 and is exposed and processed through the X-ray mask 3, a shape as shown in FIG. 5D is obtained. That is, a nozzle shape is formed in which the hole 2d is opened at the tip end surface 2e of the projection that becomes gradually thinner upward.

In the fields of information and communication and electronics, materials processed by the processing techniques according to the embodiments shown in FIGS. 1 to 5 are used for printer nozzles, semiconductor inspection probe probes, and the like. In the optical field, Fresnel lenses, micro lens arrays,
In the medical and biological measurement fields, such as a diffraction grating, a spectral grating, a filter, and an anti-reflection plate, it can be used for a wide range of applications such as a biological electrode needle, a biological fluid sampling needle, and a drug solution injection needle.

[0046]

According to the first aspect of the present invention, there is provided a method for processing a material using X-rays, comprising the steps of: forming an X-ray mask having an X-ray absorbing layer having a shape corresponding to a cross-sectional shape of a processed material in a predetermined direction; The X-ray mask is disposed at a predetermined distance from the surface, and the X-ray mask is irradiated with X-rays through the X-ray mask while relatively moving the X-ray mask in a direction orthogonal to a cross section of the material in a predetermined direction. When the material is irradiated with X-rays while moving the X-ray mask in a direction perpendicular to the cross section, the X-ray absorption in the moving direction of the X-ray mask is performed. The higher the proportion of the layer in the region, the smaller the amount of X-ray radiation applied to the material, and consequently the smaller the processing depth of the material.

Therefore, the cross-sectional shape of the above-mentioned predetermined cross-section after processing is substantially similar to the shape of the X-ray absorbing layer in the X-ray mask. As described above, according to the present invention, a desired cross-sectional shape can be processed simply by determining the shape of the X-ray absorbing layer in the X-ray mask in accordance with the cross-sectional shape of the processed material. A three-dimensional shape or the like including a curved cross-sectional shape can be easily processed.

According to a second aspect of the present invention, a method of processing a material using X-rays is such that the processing method of the first aspect is performed in a plurality of directions of the material. When the X-ray mask is processed by irradiating the X-ray while moving the mask in one direction, the cross-sectional shape of the processed material is constant in the moving direction of the X-ray mask. By performing such processing in a plurality of directions of the material, a more complicated three-dimensional structure can be created.

According to a third aspect of the present invention, there is provided a method for processing a material using X-rays according to the first or second aspect, wherein after processing the material in advance, a desired position of the processed material and a desired position of the X-ray mask are obtained. Are positioned so that they face each other, and the X-ray mask and the material are moved relative to each other.
By irradiating the material with X-rays through a line mask, the material is processed, so that a more complicated three-dimensional shape can be processed.

According to a fourth aspect of the present invention, there is provided an apparatus for processing a material using X-rays, comprising: an X-ray mask having an X-ray absorption layer having a shape corresponding to a cross-sectional shape of a processed material in a predetermined direction; And a driving section for relatively moving the material in a direction orthogonal to the cross section in the predetermined direction, so that the cross sectional shape in the predetermined cross section after processing is substantially similar to the shape of the X-ray absorption layer in the X-ray mask. Become.

Therefore, the desired cross-sectional shape can be processed only by determining the shape of the X-ray absorbing layer in the X-ray mask in accordance with the cross-sectional shape of the processed material. A three-dimensional shape including a cross-sectional shape can be easily processed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship between a processing apparatus using X-rays, an integrated dose of X-rays, and a shape of a resist material after processing in an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a shape of an X-ray mask and a cross-sectional shape of a processed resist material in the processing apparatus.

FIG. 3 is an explanatory view showing a state in which a resist material is relatively moved with respect to an X-ray mask of the processing apparatus.

FIG. 4 is an explanatory view showing a state in which an X-ray mask is exposed and processed while being sequentially moved in two directions in another embodiment of the present invention.

FIG. 5 is an explanatory view showing a state in which an X-ray mask is exposed and processed while being sequentially moved in two directions in still another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a relationship between a conventional processing apparatus using X-rays, an integrated dose of X-rays, and the shape of a resist material after processing.

FIG. 7 is an explanatory diagram showing a relationship between an integrated X-ray irradiation amount and a processing depth of a resist material.

FIG. 8 is an explanatory diagram showing a relationship between another conventional processing apparatus using X-rays, the integrated irradiation dose of X-rays, and the shape of a resist material after processing.

[Explanation of symbols]

 2 Resist material (material) 3 X-ray mask 3b X-ray absorption layer

Claims (4)

[Claims] An X-ray irradiating the material through the X-ray mask while relatively moving the X-ray mask and a material that can be processed at a depth corresponding to the X-ray irradiation amount,
In a method of processing each part of a material at a variable depth, an X having a shape corresponding to a cross-sectional shape in a predetermined direction of the processed material.
An X-ray mask having a X-ray absorbing layer is disposed at a predetermined distance from the surface of the material, and the X-ray mask is relatively moved in a direction orthogonal to a cross section of the material in a predetermined direction. A material processing method using X-rays, wherein the material is processed by irradiating the material with X-rays through a mask. 2. One or a plurality of X-ray masks each having an X-ray absorption layer having a shape corresponding to a cross-sectional shape of a material after processing in a plurality of directions, respectively, and corresponding to directions orthogonal to individual cross-sections of the material. 2. The method for processing a material using X-rays according to claim 1, wherein the X-ray mask is irradiated with X-rays to the material through the X-ray mask while relatively moving the X-ray mask. 3. After processing the material in advance, after positioning the desired position of the processed material and the desired position of the X-ray mask, the X-ray mask and the material are relatively moved. 3. The method for processing a material using X-rays according to claim 1, wherein the material is processed by irradiating the material with X-rays through the X-ray mask. 4. An X-ray mask, an X-ray irradiator for irradiating a material that can be processed at a depth corresponding to the X-ray irradiation amount through the X-ray mask, and an X-ray An apparatus for processing a material using X-rays, comprising a drive unit for relatively moving a mask, wherein the X-ray mask has an X-ray absorbing layer having a shape corresponding to a cross-sectional shape of a processed material in a predetermined direction. And the driving unit is the X
An apparatus for processing a material using X-rays, characterized by relatively moving a line mask in a direction orthogonal to a cross section of the material in a predetermined direction.