JPH0815509A - Method and apparatus for producing zone plate - Google Patents

Abstract

PURPOSE:To exactly form a pattern having a step-like shape by detecting the position of the previously formed pattern and executing alignment of exposure in accordance with the detected position information at the time of superposed exposure. CONSTITUTION:This apparatus is provided with a detecting optical system 7 for detecting the position of the pattern between a deflector 5 and an objective lens 6. The position information obtd. by the position detecting optical system 7 is outputted to a control section 12. The information is processed together with the moving distance (radial position of the detected edge position) in a radial direction in the control section 12 and is made into the information of the position where a condensed spot is to be formed. A memory 14 which is a memory means is accessed and the diameter and line width of the design pattern corresponding to the present positions (radii) are read out and the information on the working treatment region of the pattern to be formed in the position of the detected pattern diameter is selected and the movement information is outputted to a head moving section 13 which is a moving means in accordance with the the selection information in the control section 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a zone plate composed of so-called binary optics.

[0002]

2. Description of the Related Art In recent years, so-called diffractive optical elements have attracted attention as optical elements used in projection exposure apparatuses and the like. The diffractive optical element is an optical element that deflects an optical path by using a diffraction effect. According to this diffractive optical element, it is possible to arbitrarily deflect the optical path of a light beam having a short wavelength, and since it exhibits a wavelength-deflection characteristic different from that of a refraction lens, a new aberration correction member by combination with a refraction lens is provided. Applications such as these have attracted attention.

Examples of such diffractive optical elements include so-called zone plates. As this zone plate, a Fresnel zone plate having a structure in which a concentric light shielding member is provided on a light transmissive substrate as shown in FIG. 4 is generally used, but the transmission characteristics (refractive index, transmission distance, etc.) The so-called binary optics (BOE), in which concentric regions with different values are provided stepwise (where the cross-sectional shape is stepwise) and the transmission distance of the light beam incident on the element is partially made different to cause a diffractive action. Is also proposed as a new zone plate.

The manufacturing process (method) of such a zone plate will be briefly described with reference to FIG. Figure 5
(A) shows a cross section (hatched portion is a deleted portion) in a state where a concentric circular pattern is formed in the first exposure. This concentric circle pattern is formed by the following work.

First, a substrate coated with a photoresist is placed on a rotary stage, and then the rotary stage is rotated in a state where a laser beam is focused and irradiated as a minute spot on a desired position of the substrate using an objective lens. Since the substrate rotates in accordance with the rotation of the rotary stage, the focused spot focused on the substrate irradiates the substrate so as to draw a ring centered on the rotation center.

The resist on the portion of the substrate irradiated with the laser beam is exposed in a ring shape, and a ring-shaped pattern can be obtained by subsequently performing processing such as development and etching. At this time, if the focus position of the minute spot is moved in the radial direction, an annular pattern region having a line width wider than the focus spot width can be formed.

After the formation of one annular exposure processing area,
When the exposure is stopped and the focus position of the minute spot is moved in the diameter direction of the exposure processing area by a predetermined amount, the exposure is started again and the rotary stage is rotated, the above-mentioned annular exposure processing area A new annular exposure processing area (having a concentric shape) having the same center and different diameters is formed.

At this time, a highly accurate concentric pattern can be obtained by accurately monitoring the focusing position of the minute spot with a laser length measuring device or the like. Of course, the width of this another annular exposure processing region can also be adjusted by the distance to move the focus position of the minute spot there.

After a plurality of such operations are repeated to form a plurality of concentric exposure processing regions, a predetermined developing process is carried out and, if necessary, a process such as etching is carried out, as shown in FIG. A zone plate provided with a pattern of a transmissive region having a step based on the presence or absence of the etching treatment as shown is obtained. FIG. 5 (b) shows
This shows a region to be removed by etching after the second exposure is performed on the zone plate provided with the uneven cross section by the first exposure.

That is, a photoresist is applied to a zone plate having an uneven cross section by the first exposure,
When a ring-shaped exposure treatment region having a narrower width is formed in each of the region having the pattern and the region not having the pattern, and processes such as development and etching are performed, as shown in FIG.
A zone plate having the number of stages doubled as shown in (c) is obtained. FIG. 5C shows a state in which the photoresist is applied and the third exposure and the like are performed after the second exposure and the etching treatment.

As described above, when the process of forming the concentric exposure processing region and performing the etching is repeated a plurality of times, a plurality of transmissive regions (the cross-sectional shape is stepwise as shown in FIG. 5D). Zone plate (B)
OE) is obtained.

Although the zone plate (BOE) for etching the substrate to form a stepwise cross section has been described above, it goes without saying that the annular thin films as shown in FIG. 6 are laminated to form a stepwise cross section. Forming zone plates (BOE) have also been proposed. This is because a thin film layer is provided between the photoresist and the substrate, the photoresist is exposed in a concentric pattern, and the thin film layer existing in a region other than the exposed region is repeatedly etched and removed to form a concentric pattern. The pattern is formed.

[0013]

As described above, the BO
In order to form the stepwise cross section of E, an exposure step of exposing the substrate according to the concentric circular pattern and an etching step of removing the substrate from the rotary stage and performing development and etching treatment must be repeated a plurality of times. I won't.

At this time, in the second and subsequent exposure processes, if the substrate is not accurately arranged at the same position as the position where it was initially installed, the second and subsequent exposure patterns will be different from the uneven pattern formed previously. It will shift.

When the concentric patterns are displaced and exposed,
The stepped pattern of the zone plate (BOE) obtained by etching thereafter does not have a desired shape. Such a zone plate has a problem that the diffraction efficiency is lowered, the scattered light stray light is increased, and the wavefront aberration is generated.

In order to prevent such a shift of the exposure position,
A method of detecting the positional deviation between the center of the substrate and the center of rotation as eccentricity information and decentering the irradiation position of the focused spot at the time of exposure based on this eccentricity information to perform exposure is disclosed in JP-A-5-16.
No. 5222. Here, a reference ring other than the pattern is formed in advance, and another concentric pattern is also aligned with this reference ring.

However, even in this method, there is a problem in that a fine misalignment of the eccentricity information affects the exposure processing area and an accurate concentric pattern cannot be formed. It is considered that this is influenced by the expansion and contraction of the substrate, the eccentricity tolerance of the rotary stage, the detection of the rotation angle, and the time error with respect to these feedbacks.

In particular, when forming a stepped pattern which becomes one diffraction pattern of BOE, it is necessary to provide a plurality of exposure processing regions on the already formed pattern and adjacent thereto. However, in the above-mentioned conventional technique, there is a slight deviation between them, and the stepwise overlapping pattern cannot be formed accurately, and there is a problem that the design diffraction effect cannot be obtained.

The present invention has been made in view of the above problems, and proposes a zone plate manufacturing method capable of accurately forming a pattern having a stepped cross section by combining concentric patterns a plurality of times. To aim. Another object of the present invention is to provide a zone plate manufacturing apparatus capable of accurately forming a stepped concentric circle pattern.

[0020]

According to a first aspect of the present invention, there is provided a method of manufacturing a zone plate, wherein a diffraction pattern having a stepwise cross-section is formed by exposing different concentric circular patterns on a substrate and exposing them. Therefore, in the second and subsequent overlay exposures, the position of the pattern previously formed is detected, and the exposure position is adjusted based on the position information detected here. A plate manufacturing method is proposed.

According to a second aspect of the present invention, the rotating workpiece is exposed to light to form an annular exposure processing area on the workpiece, and the exposure position on the workpiece is moved. The present invention relates to a zone plate manufacturing apparatus that forms a concentric pattern on a workpiece by performing exposure processing at different positions.

According to the present invention, the rotary table on which the workpiece is placed, the exposing means for converging and irradiating the surface of the workpiece with predetermined exposure light, and the exposure position of the exposing means are at least the rotary table is rotated. Based on the moving means for moving in the direction orthogonal to the central axis, the pattern position detecting means for detecting the position of the concentric pattern formed on the workpiece, and the pattern position information detected by the pattern position detecting means. While determining the exposure processing area on the workpiece,
It has been proposed to provide a control means for moving the exposure position by the moving means so as to irradiate the inside of the exposure area.

Further, in the invention of claim 3, in the zone plate manufacturing apparatus according to claim 2, a storage area for storing a processing area determined by a diameter and a radial width of a concentric pattern formed on a workpiece. The control means further includes means, and detects the diameter of the pattern from the pattern position information detected by the pattern position detection means, and stores the processing area information of the pattern to be formed at the position of the detected pattern diameter from the storage means. The exposure position is moved by the selected width from the edge position of the pattern selected based on the selection information.

The invention of claim 4 is the same as claim 2 or 3
In the zone plate manufacturing apparatus described in (1), the pattern position detecting means is a contact-type position detecting means that uses a light beam that does not substantially affect the photosensitive member formed on the workpiece as inspection light. There is.

Further, the invention of claim 5 is the zone plate manufacturing apparatus according to any one of claims 2 to 4, wherein the pattern position detecting means irradiates the workpiece with inspection light and the workpiece. The position of the pattern is detected by detecting the scattered light at the edge portion of the pattern formed above.

[0026]

According to the present invention, the rotating work piece is exposed to form an annular exposure processing area on the work piece, and the exposure position on the work piece is moved to a different position. The present invention relates to a zone plate manufacturing method for forming a concentric pattern on a workpiece by performing an exposure process.

In such a zone plate manufacturing method, it is important to eliminate the deviation from the previously formed pattern during the second and subsequent overlay exposures. In the present invention, the previously formed pattern is eliminated. It is proposed that a zone plate with no pattern shift is obtained by performing the next exposure process using the pattern as a reference.

The pattern formed on the surface of the workpiece is distinguished from the adjacent pattern areas by the step. The second and subsequent exposure processes determine the cutting area for cutting the edge portions of the pattern area one after another to form a stepped pattern, and this cutting area is always separated from the edge portion by a predetermined distance. It is an annular region having a width.

In the present invention, focusing on the exposure area from this edge portion, the edge portion of each pattern area is detected,
A zone plate having no stepwise pattern displacement is obtained by performing exposure for a predetermined distance (width of the annular exposure area) from there.

That is, since the exposure process is always performed while observing the previously formed pattern, the obtained patterns are misaligned even if the pattern formation including the exposure process and the etching process is performed a plurality of times. It is possible to obtain the zone plate as designed without causing the above.

Now, the method of the present invention will be described with reference to FIG. FIG. 3 is a schematic view of a case where a stepped cross section is formed by etching the substrate. FIG. 3 is an explanatory diagram showing a state in which the second exposure has been performed. As can be seen from this figure, the surface of the work piece after the first exposure process is an uneven pattern in which convex patterns and concave patterns are alternately combined, so that the region to be cut has a convex pattern. There are edge portions and edge portions of the concave pattern.

When cutting the edge portion of the convex pattern, the edge position X of the convex pattern may be detected and a focused spot, which is exposure light, may be irradiated along the edge position X of the convex pattern. At this time, if the width α ₁ of the annular exposure area is the same as the exposure processing width φ (hereinafter referred to as the effective diameter) obtained by the converging spot, a position separated by φ / 2 from the edge position X of the convex pattern. By arranging the center position of the focused spot at, an annular exposure processing region having a desired width can be obtained.

The width α _{1 of the} annular exposure area is the effective diameter φ.
If it is larger than the above, the exposure processing may be performed by overlapping the condensed spots a plurality of times until the desired width is obtained. For example,
The center position of the focused spot is arranged at a position separated from the edge position X of the convex pattern by φ / 2 to form the first annular exposure processing region.

Next, the central position of the focused spot is slightly shifted toward the center of the convex portion (in the direction of the arrow in FIG. 3) to form the second annular exposure processing region. By arranging the converging spot position so that the irradiation region of (1) overlaps (or contacts) the previous exposed region, it is possible to obtain an annular exposure processing region having a width wider than the effective diameter φ of the converging spot. Of course, the focused spot may be expanded to a desired width to obtain a wide annular exposure processing region.

Also, when cutting the edge portion of the concave pattern, similarly to the above, the edge position Y of the concave pattern may be detected, and a focused spot may be irradiated along the edge position Y of the concave pattern for exposure. . The width of the exposure processing area at this time can also be subjected to the exposure processing so as to superimpose the converging spot positions, or enlarged to a desired width, so that a wide annular exposure processing area can be obtained.

That is, since the cutting area of the pattern to be formed next is determined with the previously formed pattern as a reference, an annular exposure processing area whose center exactly matches the concentric pattern obtained last time is formed. Therefore, it is possible to accurately form a pattern having a stepped cross section without causing a pattern shift.

Further, the present invention proposes a zone plate manufacturing apparatus for performing exposure by such a method. That is,
The exposure process and the etching process are completed at least once, and at least one step of the uneven cross section (hereinafter,
Marked as the last unevenness. ), The pattern position detecting means detects the position of the pattern of the previous unevenness and outputs it to the control means.

This control means calculates the focused spot position by the exposure means to be a predesigned position based on the position information inputted by the pattern position detection means, and the calculation result is the arrangement position of the exposure means. It is output to the transportation means as information.

The moving means moves the exposing means on the basis of the input arrangement position information, and controls so that the focused spot position is exactly at a predesigned position on the workpiece.

That is, the unevenness information detected by the pattern position detecting means is converted into position information of the exposure area to be exposed next by the control means and output to the moving means, and the exposure processing area to be exposed next is already formed. The pattern that is newly obtained is also a concentric circle that is exactly adjacent to the pattern that was obtained last time without shifting from the pattern that has been made.

Therefore, since the finally obtained zone plate has the same pattern as the designed pattern, the diffraction efficiency is good, the scattered light stray light is small, and the wavefront aberration is hard to occur.

In such a zone plate manufacturing apparatus, it is preferable that the zone plate manufacturing apparatus further comprises storage means for storing a processing area determined by the diameter of the concentric circular pattern formed on the workpiece and the width in the radial direction.

By providing the storage means for storing the diameter of the pattern and the processing area, the control means automatically operates on the basis of the position information inputted by the pattern position detecting means and the processing area information from the storage means. The position and the amount of movement of the moving unit can be determined, and it becomes possible to automatically form a plurality of annular exposure processing regions by performing continuous exposure processing.

Further, as the pattern position detecting means, there may be mentioned one which irradiates light to the unevenness of the previous time to detect the reflected light. At this time, the light irradiating the surface of the workpiece is the exposure light and the light other than the exposure light. And the light of.

When the exposure light is used, the structure of the apparatus can be simplified because no extra optical system is required, but in the case where the exposure step and the etching step are repeated many times, such as BOE. In manufacturing, the resist formed on the surface of the workpiece may be exposed to light during the position detection for the next exposure process.

Therefore, in the present invention, it is also proposed that the pattern position detecting means be of a contact type in which a light beam which does not substantially affect the photosensitive member formed on the workpiece is used as the inspection light. There is. As a result, the resist layer formed on the surface to be processed is not exposed when detecting the previous unevenness, and it does not disturb the shape of the surface, so the position is continuously detected and exposed. Processing can be performed.

Further, according to the present invention, the pattern position detecting means irradiates the workpiece with the inspection light and detects the scattered light at the edge portion of the pattern formed on the workpiece to detect the pattern. A device that detects the position is also proposed. That is, the detection system for detecting the scattered light has a simple configuration, and therefore the design is simple, and the range of the design of the entire apparatus is widened, which is convenient.

[0048]

EXAMPLE FIG. 1 shows a schematic structure of a zone plate manufacturing apparatus. In this embodiment, the exposure light flux has a wavelength of 365 nm.
The laser light flux from the Ar laser light source 1 is used. The substrate 8 coated with a resist film, which is a workpiece, is placed on the rotary stage 9, and the substrate 8 is rotated according to the rotation of the rotary stage 9. Since the light flux from the laser light source 1 is condensed on this substrate, the substrate 8 is exposed in a ring shape.

In FIG. 1, a light flux emitted from a laser light source 1 is adjusted to a desired intensity by a modulator 2 and emitted. The light flux emitted from the modulator 2 enters the beam expander 3, where the diameter of the light flux is expanded and the deflector 5 is illuminated. The deflector 5 is a deflector that changes the traveling direction of incident light, and changes the position of a condensing spot described later to condense the light at a correct position.

The light beam from the deflector 5 enters the objective lens 6, is reduced to 1/100 by the objective lens 6, and is irradiated as a focused spot on the substrate 8 which is the object to be processed.

Since the substrate 8 is adapted to rotate in accordance with the rotation of the rotary stage 9, the focused spot irradiated on the substrate 8 irradiates the substrate 8 in an annular shape. At this time, the focus (substrate vertical position) detector including the LED 10 and the position sensor 11 detects the position of the substrate 8 and automatically raises and lowers the objective lens 6 to constantly keep the substrate 8
It is adjusted so that it can be focused on the fluctuation in the vertical direction.

Further, a detection optical system 7 for detecting the position of the pattern is provided between the deflector 5 and the objective lens 6. A schematic diagram of the position detecting optical system 7 is shown in FIG. The position detection optical system 7 receives the illumination light from the tungsten lamp 71 through the beam splitters 72 and 74 and then to the substrate 8
An illumination system for illuminating the upper part and a detection system for detecting the scattered light scattered at the edge portion of the pattern of the substrate 8 via the beam splitters 72 and 74, and further including a glass filter 73 in the optical path thereof. There is.

The glass filter 73 absorbs light of a short wavelength in the illumination light so that the resist is not exposed and the laser light is prevented from entering the detector 75. The scattered light scattered at the edge portion of the pattern of the substrate 8 is imaged on the position detector 75 such as CCD, and the position of the focused spot on the substrate 8 can be known by detecting this signal.

The position information obtained by the position detection optical system 7 is output to the controller 12. This information is sent to the control unit 12
Is processed together with the moving distance in the radial direction (radial position of the detected edge position), and becomes the information of the position where the focused spot is formed. The control unit 12 accesses the memory 14 as a storage unit to read the diameter and line width of the design pattern corresponding to the current position (radius), and also the processing area of the pattern formed at the position of the detected pattern diameter. The information is selected, and the movement information is output to the head moving unit 13 which is the moving means based on the selected information.

Further, the control unit 12 issues an output off command to the laser light source 1 after forming one exposure processing area, and when the movement of the head 4 by the head moving unit 13 to be described later is completed, the output is turned on again to the laser light source 1. Has issued a command. At the same time, a command signal for changing the intensity of the modulator 2 according to the radial position is sent.

The above-mentioned deflector 5, objective lens 6,
Position detection optical system 7, LED 10 and position sensor 1
A focus (substrate vertical position) detector consisting of 1 and 1 is incorporated in one head 4, and the head moving unit 13 that receives the movement information from the control unit 12 determines the diameter of the head 4 based on the movement information. Is moving in the direction.

The moving distance of the head 4 is accurately read by a laser interferometer (not shown), and the value is fed back to the head moving unit 13 to accurately control the position of the head 4. If the control cannot follow, change the spot position with the deflector 5,
Correct to the correct position.

The method of manufacturing the zone plate according to the method of the present invention will be described below. After applying a photoresist to the surface of the substrate 8, the substrate 8 is placed on the rotary stage 8. The rotary stage 9 is rotated in a state where the laser light is focused and irradiated as a minute spot on a desired position on the substrate 8. Since the substrate 8 is rotated according to the rotation of the rotary stage 9, the focused spot focused on the substrate 8 irradiates the substrate 8 so as to draw a circle centered on the rotation center.

The center of rotation of the rotary stage and the center of coordinates of the head moving unit 13 before the exposure process are pre-aligned, and the desired zone plate pattern shape (position and width in the radial direction) is previously stored in the memory 14. Has been entered in. Then, the head moving unit 13 is moved so that the focused spot comes to the edge position of one pattern, and the laser beam is emitted while rotating the rotary stage 9. As a result, the resist on the substrate 8 is exposed in an annular shape.

After the formation of one annular exposure processing area,
The control unit 12 turns off the laser light source 1, reads the position information of the next pattern from the memory 14, and outputs the movement information to the head moving unit 13. After the head moving unit 13 moves the focus position of the focus spot in the diameter direction of the exposure processing area by a predetermined amount, the control unit 12 turns on the laser light source 1 and starts the exposure again. A new annular exposure processing area is formed which has the same center as the annular exposure processing area but a different diameter.

After a plurality of such operations are repeated to form a plurality of concentric exposure processing regions, predetermined development is performed, and if necessary, a process such as etching is performed.
A pattern including a transmissive region having a step based on the presence or absence of the etching process is provided.

Photoresist is applied again to the surface of the substrate 8 provided with the step pattern, and a second exposure process is performed. At this time, the center of the step pattern already formed is set to the center of the rotary stage. It is extremely difficult to accurately position and place the plate, and a slight positional deviation occurs here. When the rotary stage is rotated in this state, the step pattern is rotated in an eccentric state.

Here, by applying the above-mentioned conventional example, eccentricity information (eccentricity distance based on the rotation angle, etc.) is detected from this step pattern, and according to this eccentricity information, the focused spot of the focused spot is generated as the substrate 8 rotates. By moving the position (eccentricity),
Conceptually, accurate concentric pattern overlay exposure is possible.

However, the expansion and contraction of the substrate due to the temperature change and the process, and the position shift of the focused spot due to the time shift such as the detection of the rotation angle and the processing of the minute movement of the focused spot is actually caused. In many cases, accurate overlay exposure cannot be performed. This is a fatal problem for an optical member that requires precise processing, and there is also a problem that the manufacturing cost of the diffractive optical element increases because the product yield is low.

Therefore, in this embodiment, the edge position is directly detected during the exposure operation, and the exposure is performed from the detected edge position. That is, in the apparatus according to the present embodiment, the position detection optical system 7 detects the edge portion of the step pattern already formed and outputs the detected information to the control unit 12.

The control unit 12 outputs the information of the irradiation position of the focused spot to the head moving unit 13 as the moving information of the head position based on the input detection information and the design information obtained by accessing the memory 14. There is. Head moving unit 13
Controls the focus spot position so that the focus spot position is located along the edge based on this command information, and if necessary, a constant distance (in the diameter direction) is always maintained from this edge position. are doing.

By repeating the exposure operation by such a method, it is possible to form an annular exposure processing region that is accurately superimposed on the concentric pattern obtained previously.
These are exactly concentric with the step patterns already formed. Therefore, the step pattern newly obtained by performing the processing such as the subsequent development and etching is formed in a state of being accurately adjacent to each other without causing eccentricity with respect to the step pattern formed last time, The design pattern is transferred to.

As described above, in the present embodiment, the edge position is detected during the exposure process, and the positional information is fed back to the head moving unit during the on-time, so that the deviation from the concavo-convex pattern formed last time is detected. Is lost.

[0069]

As described above, according to the zone plate manufacturing method of the present invention, it is possible to accurately form a pattern having a stepwise cross section by combining concentric patterns a plurality of times.

Further, according to the zone plate manufacturing apparatus of the present invention, the designed concentric pattern can be accurately exposed. Therefore, the finally obtained zone plate such as Fresnel zone plate or BOE has high accuracy, uniform diffraction efficiency, and small wavefront aberration.

Further, since the zone plate manufactured by the zone plate manufacturing apparatus of the present invention has a high yield, there is an advantage that the manufacturing cost of the zone plate can be reduced as a result.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a zone plate manufacturing apparatus of the present invention.

FIG. 2 is an explanatory diagram showing an outline of a position detection optical system of the present invention.

FIG. 3 is an explanatory diagram showing an outline of a Fresnel zone plate.

FIG. 4 is a schematic cross-sectional view of binary optics.

FIG. 5 is a schematic view of a method for manufacturing binary optics.

FIG. 6 is a schematic view of a method of manufacturing a stacked binary optics.

[Explanation of symbols]

 1 Ar Laser Light Source 2 Modulator 3 Beam Expander 4 Head 5 Deflector 6 Objective Lens 7 Position Detection Optical System 71 Tungsten Lamp 72, 74 Beam Splitter 73 Glass Filter 75 Detector 8 Substrate 9 Rotation Stage 10 LED 11 Position Sensor 12 Control Section 13 Head moving part 14 Memory

Claims (5)

[Claims] 1. A method of manufacturing a zone plate, wherein a different structure of concentric circles is overlaid on a substrate and exposed to light to form a structure having a stepwise cross-sectional shape. In addition, the method of manufacturing a zone plate is characterized in that the position of a pattern formed before that is detected and the exposure position is adjusted based on the position information detected here. 2. A ring-shaped exposure processing region is formed on the workpiece by exposing the rotating workpiece, and the exposure position on the workpiece is moved to change the exposure position at different positions. In a zone plate manufacturing apparatus that forms a concentric pattern on a workpiece by performing an exposure process, a rotary table on which the workpiece is placed, and a predetermined exposure light on the surface of the workpiece. Exposure means for converging and irradiating; moving means for moving an exposure position by the exposure means at least in a direction orthogonal to the rotation center axis of the rotary table; and a position of a concentric pattern formed on the workpiece. A pattern position detecting unit for detecting, and an exposure processing region on the workpiece based on the pattern position information detected by the pattern position detecting unit, and the moving unit. That the zone plate manufacturing apparatus is characterized in that a control means for moving so as to irradiate the exposure position of the exposure area. 3. A storage means for storing the processing area defined by the diameter of the concentric circular pattern formed on the workpiece and the width in the radial direction, the control means detecting by the pattern position detecting means. While detecting the diameter of the pattern from the pattern position information obtained, select the processing area information of the pattern to be formed at the position of the detected pattern diameter from the storage means, of the detected pattern based on this selection information The zone plate manufacturing apparatus according to claim 2, wherein the exposure position is moved by a width selected from the edge position. 4. The pattern position detecting means is position detecting means that uses, as the inspection light, a light beam that does not substantially affect the photosensitive member formed on the workpiece. Or the zone plate manufacturing apparatus described in 3. 5. The pattern position detecting means irradiates the workpiece with inspection light and detects scattered light at an edge portion of a pattern formed on the workpiece to detect the position of the pattern. The zone plate manufacturing apparatus according to any one of claims 2 to 4, wherein