JP2005064299A - Method and apparatus of exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for exposure wherein a space on a mask is effectively utilized and the constitution of a mechanism for carrying out the distinction of the mask and alignment is simplified and miniaturized. <P>SOLUTION: A mask distinction mark detector 131 detects the mask distinction mark 14 of the mask 10. A mask distinction mark decoder 133 is connected with the detector 131 to decode data of the mark 14 read by the detector 131. Thus, the kind (model number etc.) of the mask 10 is distinguished. A microscope 132 for mark detection obtains the image of the mark 14 of the mask 10. A mark position detection processor 134 is connected with the microscope 132 to process a mark image sent from the microscope 132. Thus, the positional information of the mask 10 is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure method and an exposure apparatus used for semiconductor lithography and the like. In particular, the present invention relates to an exposure method and an exposure apparatus in which a space on a mask can be effectively used, and the configuration of a mask alignment mechanism is simplified and miniaturized.

  In recent years, with the miniaturization and high integration of semiconductor integrated circuits, instead of photolithographic technology using light, which has been the mainstream method for forming fine patterns for many years, charging such as electron beams and ion beams is used. New exposure methods using particle beams or X-rays are being studied and put into practical use. Among these, an electron beam projection projection method (EPL) that forms a pattern using an electron beam can achieve high throughput and can cope with an increase in memory production. Has been.

  In electron beam exposure, a pattern obtained by enlarging a desired pattern is used as a mask pattern (original pattern), and this mask pattern is reduced and projected with an electron beam on a wafer to form a device pattern on the wafer. For electron beam exposure, a reduction transfer method using a mask and an EB optical system capable of irradiation with a large aperture beam are employed. By using these techniques, the throughput of the exposure work can be improved.

  In the exposure apparatus as described above, a plurality of masks are used while being managed. For this reason, marks such as barcodes are drawn on a mask, and the mask is managed by reading and identifying the marks. As an example of an apparatus for reading such a barcode, a barcode is illuminated using a light source such as a red LED (Light-Emitting Diode), and a barcode image is formed on a CCD sensor via a lens. For example, the barcode image can be determined by processing the acquired barcode image.

  By the way, in the EPL currently under development, the division transfer method is used. In the divided transfer method, the pattern is divided into a plurality of small areas (subfields) on the mask, exposed in batches for each subfield, and images of the plurality of subfields are joined and transferred on the wafer. The method to do. In the divided transfer system, when subfield images are joined together, a pattern is transferred onto the wafer without a gap by overlapping a part of the subfields. In the divided transfer method, it is necessary to join (superimpose) the images of the subfields on the wafer with high accuracy. In order to achieve highly accurate pattern overlay on the wafer, the alignment of the mask is performed by drawing an alignment mark on the mask and detecting the position of the mark. As a method for detecting the alignment mark, for example, there is a method in which the alignment mark is imaged by a CCD camera via an optical microscope and the position of the mark is detected.

When a mark for identifying a mask or an alignment mark as described above is drawn on the mask, a space for two types of marks is required, so that an effective space for forming a pattern on the mask is narrowed. There is a problem. In addition, the reserved area in the design increases, and an area that can be used when a mask maker manufactures a mask (for example, an area where an alignment mark for pattern drawing is formed or a mask is handled in a mask manufacturing process) The area for this is also narrowed. The reserved area in the design is an area that cannot be freely used by the mask manufacturer.
Furthermore, when the mask identification mark and the apparatus for reading the alignment mark are separately installed in the exposure apparatus, a space for installing the two apparatuses is required, which increases the size of the exposure apparatus and reduces the cost. Influence.
In view of the above points, the present invention provides an exposure method and an exposure apparatus that can effectively use the space on the mask and that have a simplified and miniaturized structure of the mechanism for identifying and aligning the mask. For the purpose.

An exposure method of the present invention is an exposure method for transferring a pattern on a mask onto a sensitive substrate while managing a plurality of masks (including a reticle) as a device pattern original, and identifying the plurality of masks A mask identification mark is attached to the surface of each mask, the position of the mask identification mark is detected, and the mask is positioned (aligned) based on the position information of the mark. To do.
According to the present invention, the mask identification mark can be used as an alignment mark. Thereby, the space on the mask can be effectively used.
In general, mask alignment is performed in a plurality of stages. For example, it is performed in three stages: primary, course (coarse alignment), and fine (fine alignment). The present invention is considered to be particularly effective when applied to course alignment.

  In the exposure method of the present invention, the mask identification mark may be a one-dimensional barcode or a two-dimensional code (stacked code, matrix code, etc.).

  An exposure apparatus of the present invention is an exposure apparatus that transfers a pattern on a mask (including a pattern original plate and a reticle) onto a sensitive substrate, and an optical system that irradiates a mask identification mark on the mask with probe light; Positioning (alignment) of the mask by reading light hitting the mask identification mark and detecting the position of the mask identification mark and operating the mask stage based on the position information of the mask identification mark And means for performing.

Another exposure apparatus of the present invention is an exposure apparatus for transferring a pattern on a mask (including a pattern original plate and a reticle) onto a sensitive substrate, and a probe beam is applied to the mask identification mark and the mask position detection mark on the mask. A mark detection means comprising: an optical system for irradiating light; and a detection processing unit that reads the light hitting the mask identification mark and the mask position detection mark and detects the positions of the mask identification mark and the mask position detection mark, respectively. And means for positioning the mask by operating a mask stage based on positional information of the mask identification mark and the mask position detection mark.
According to the present invention, an apparatus for reading the mask identification mark and the mask position detection mark can also be used. Thereby, the size of the exposure apparatus can be reduced, and the cost performance of the exposure apparatus can be improved.

  In the exposure apparatus of the present invention, it is preferable that a mask moving / rotating unit for moving the mark within the field of view of the mark detecting unit is provided.

In the exposure apparatus of the present invention, it is preferable that the mark detection unit includes a switching unit that switches between a mask identification mark detection processing unit and an alignment mark detection processing unit.
According to the present invention, the optical system for detecting and processing the mask identification mark and the optical system for detecting and processing the alignment mark are made common, so that the exposure apparatus can be reduced in size and cost.

  According to the present invention, the space on the mask (reticle) can be used effectively. Further, by sharing a mechanism for mask identification and position detection, it is possible to reduce the size and cost of the exposure apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, an outline of the electron beam exposure method will be described.
FIG. 1 is a schematic diagram showing an imaging relationship in the entire optical system of an electron beam exposure apparatus (divided transfer method) according to the first embodiment of the present invention.
An electron gun 1 is arranged above the drawing (upstream of the optical system). The electron gun 1 irradiates an electron beam downward in the figure. Below the electron gun 1, two-stage condenser lenses 2 and 3 are provided. The electron beam is converged by these condenser lenses 2 and 3, and crossover C.D. O. Is imaged.

  An illumination beam shaping aperture 4 is disposed below the condenser lens 3. This opening 4 allows only an illumination beam that illuminates one subfield of the mask 10 (a small pattern area serving as one unit of exposure) to pass through. The image of the opening 4 is formed on a mask (reticle) 10 by a lens 9.

  A blanking deflector 5 is disposed below the illumination beam shaping opening 4. The deflector 5 deflects the illumination beam as necessary and hits the non-opening portion of the blanking opening 7 so that the beam does not hit the mask 10.

  An illumination beam deflector 8 is disposed below the blanking opening 7. The deflector 8 sequentially scans the illumination beam in the X-axis direction to illuminate each subfield of the mask 10 in the field of the optical system. An illumination lens 9 is disposed below the deflector 8. The illumination lens 9 images the illumination beam on the mask 10.

  The mask 10 extends in a plane (XY plane) perpendicular to the optical axis, and has a number of subfields (details will be described later with reference to FIG. 2). On the mask 10, a device pattern that forms one semiconductor chip as a whole is formed. A device pattern forming one chip may be divided and formed on a plurality of masks.

  The mask 10 is held on a movable mask stage 11. The mask stage 11 is connected to a stage controller 11a, and the stage controller 11a controls the mask stage 11. By moving the mask stage 11 in the XY directions, each subfield on the mask 10 that extends over a wider range than the field of view of the illumination optical system can be illuminated. A position detector (interferometer) 12 is attached to the mask stage 11 so that the position of the mask stage 11 in the XYZ directions can be accurately grasped.

  A mask identification mark 14 is formed on the mask 10 (details will be described later with reference to FIGS. 2 and 3). A mark detection processor 13 is attached to the mask stage 11. The mark detection processor 13 detects a mask identification mark 14, and performs mask identification and mask position detection. The position detection result of the mask 10 by the mark detection processor 13 is fed back to the stage controller 11a (see FIGS. 4 to 6).

  Projection lenses 15 and 19 and a deflector 16 are provided below the mask 10. The electron beam that has passed through one subfield of the mask 10 is imaged at a desired position on the wafer 23 by the projection lenses 15 and 19 and the deflector 16.

  An appropriate resist is applied on the wafer 23. An electron beam dose is given to the resist, and the device pattern on the mask 10 is reduced and transferred.

  At a position where the space between the mask 10 and the wafer 23 is internally divided by the reduction ratio, the crossover C.I. O. The contrast opening 18 is provided at this position. The opening 18 blocks the electron beam scattered by the non-patterned portion of the mask 10 from reaching the wafer 23.

  The wafer 23 is disposed on a wafer stage 24 that can move in the X-axis and Y-axis directions via an electrostatic chuck (not shown). By synchronously moving the mask stage 11 and the wafer stage 24 in opposite directions, a device pattern that extends beyond the visual field of the optical system can be sequentially exposed and transferred. The wafer stage 24 also includes a position detector 25 as in the mask stage 11 described above.

  A backscattered electron detector 22 is disposed immediately above the wafer 23. The backscattered electron detector 22 detects the amount of electrons reflected by the exposure surface of the wafer 23 and the mark on the wafer stage 24. For example, the relative positional relationship between the mask 10 and the wafer 23 can be known by scanning the mark on the wafer 23 with a beam that has passed through the mark pattern on the mask 10 and detecting electrons reflected by the mark.

  The lenses 2, 3, 9, 15, 19 and the deflectors 5, 8, 16 are respectively connected to the corresponding coil power supply control units 2a, 3a, 9a, 15a, 19a and 5a, 8a, 16a. Controlled by the controller 31. The mask stage 11 and the wafer stage 24 are also controlled by the controller 31 via the corresponding stage controllers 11a and 24a.

  The stage position detectors 12 and 25 send signals to the controller 31 via the interfaces 12a and 25a including amplifiers and A / D converters. The mark detection processor 13 also sends a signal to the controller 31. Similarly, the backscattered electron detector 22 sends a signal to the controller 31 via the interface 22a.

  The controller 31 grasps the alignment error of the stage and corrects the error by the image position adjusting deflector 16. As a result, the reduced image of the subfield on the mask 10 is accurately transferred to the target position on the wafer 23. Then, the images of the subfields are joined on the wafer 23, and the entire device pattern on the mask 10 is transferred onto the wafer.

FIG. 2 is a view showing a mask used in the electron beam exposure apparatus according to the first embodiment of the present invention. 2A is a plan view of the whole, FIG. 2B is a partial perspective view, and FIG. 2C is a plan view of one small membrane region.
In the mask 10 shown in FIG. 2, the device pattern is divided and formed. A large number of squares 41 shown in FIG. 2A are small membrane regions each including a device pattern corresponding to one subfield. The small membrane region 41 is a silicon membrane, and has a thickness of about 2 μm as an example.

  A lattice-shaped portion around the small membrane region 41 shown in FIGS. 2 (A) and 2 (B) is a minor strut 45. The minor struts 45 are beams (for example, a thickness of 0.5 to 1 mm and a width of 0.1 mm) for maintaining the mechanical strength of the mask 10. Further, the minor strut 45 has thermal conductivity and plays a role of releasing heat generated in the silicon membrane by irradiation with an electron beam. The small membrane region 41 has a concave shape surrounded by the struts 45.

  As shown in FIG. 2A, a large number of small membrane regions 41 are arranged in the X direction in the figure to form one group (electrical stripe 44). A large number of electrical stripes 44 are arranged in the Y direction in the figure to form one mechanical stripe 49. The length of the electrical stripe 44 (the width of the mechanical stripe 49) is limited by the width of the field of view that can be covered by the deflection of the optical system.

  A plurality of mechanical stripes 49 (two in the present embodiment) are arranged in the X direction in the figure. A portion between adjacent mechanical stripes 49 is a major strut 47. The major strut 47 is a beam slightly thicker than the minor strut 45, and reduces the deflection of the mask 10. Major struts 47 and minor struts 45 are integrated. In the following description, the minor strut 45, the major strut 47, and the peripheral portion 50 are collectively referred to as a support substrate portion.

As shown in FIG. 2A, a mask identification mark 14 is provided on the support substrate portion 50 below each mechanical stripe 49. In this embodiment, mask identification and position detection are performed using the mask identification mark 14.
An example of the mask identification mark 14 will be described later with reference to FIG. The number and arrangement of marks on the mask are merely examples, and are not limited to those shown in FIG.

As shown in FIG. 2C, the small membrane region 41 includes a central subfield 42 and a skirt 43 surrounding the periphery thereof in a frame shape.
The subfield 42 is, for example, a square having a side of about 0.5 to 5 mm. If the reduction ratio at the time of projection is 1/5, the image of the subfield 42 projected onto the wafer is a square with one side of 0.1 to 1 mm. In the subfield 42, a pattern opening (stencil) corresponding to the shape of the individual element figure of the pattern to be transferred onto the wafer is formed. The size of the subfield that can be exposed in one shot is, for example, about 0.25 mm square on the wafer.
The skirt 43 is a frame-like part (with a width of 0.05 mm in one example) where no pattern is formed, and the edge of the illumination beam hits it.

  A method in which a non-pattern region such as a skirt or a minor strut is not provided between adjacent subfields in one electrical stripe 44 is also being studied.

Hereinafter, an example of the mask identification mark 14 will be described.
FIG. 3 is a diagram illustrating an example of the mask identification mark. 3A is a plan view showing a part of a mask identification mark using a one-dimensional barcode, and FIG. 3B is a plan view showing a mask identification mark using a data code. FIG. 3C is a plan view showing a mask identification mark using a QR code.

The mask identification mark 14a shown in FIG. 3A is a one-dimensional barcode (CODE39). The CODE 39 can handle alphabets and symbols, and is suitable for expressing information such as product numbers. The bar code 14a is composed of a quiet zone 101, a start character 102, a character 103, and a stop character and a quiet zone (not shown) in order from the left in the figure. The barcode 14a is scanned in order from left to right in the figure.
The quiet zone is a margin (margin) portion arranged so as to sandwich the left and right sides of the bar code, and a bar code with a vertical stripe pattern is formed between the quiet zones by, for example, etching or film formation. .

  In the one-dimensional barcode (CODE 39), the configuration of the stripe pattern of the character 103 is different for each barcode. The striped pattern of the character 103 is a portion expressing data for identifying the mask, and the mask is identified by reading the character 103.

  On the other hand, the start character 102 and the stop character are portions representing the beginning and end of the barcode data, respectively. In the case of CODE 39, the start character 102 and the stop character are the same in any barcode regardless of the content of the character 103, and thus are easily used for position detection. The position of the mask is measured by capturing and processing images of the start character 102 and the stop character.

  The mask identification mark in this embodiment may be a bar code having a start character or a stop character. The start character and stop character of the CODE 39 mentioned above can be one type for all the masks used, so that it can be easily applied to mask position detection.

The mask identification mark 14b shown in FIG. 3 (B) uses a data code (data matrix code), and the mask identification mark 14c shown in FIG. 3 (C) uses a QR (Quick Response) code. It is.
These codes are formed on the mask 10 by, for example, etching or film formation.
These two-dimensional codes can express a large amount of data compared to the one-dimensional code. If the amount of information is equivalent to that of a one-dimensional barcode, it can be expressed in a smaller size. For example, when a QR code is used, the space required to represent the same amount of data as CODE 39 is about 1/30. Further, the two-dimensional code has an error correction function, and data can be read even when the mark is slightly damaged.

  The data code 14b shown in FIG. 3B is substantially square, and an L-type guide cell (alignment pattern) 111 and a data cell 112 (remaining part) formed on the left side and the lower side in the figure. Including. The QR code 14c shown in FIG. 3 (C) is substantially square and has a square cut-out symbol (finder pattern) 113 and data cells 114 (remaining) formed at three corners on the upper right, upper left and lower left in the figure. Part). The data cells 112 and 114 contain information for identifying the mask, and the mask is identified by reading them.

  The L-type guide cell 111 and the cut-out symbol 113 are patterns (code position detection patterns) for determining the position and orientation of the code. A matrix type two-dimensional code such as a data code or a QR code can be read from any direction because the position and orientation of the code can be determined by reading such a code position detection pattern. Yes.

These L-type guide cells 111 and cutout symbols 113 are used as mask alignment marks. That is, in the present embodiment, the position of the mask is measured by processing the images of the L-type guide cell 111 and the cut-out symbol 113 using the mark detection processor 13 (see FIG. 1 and the like).
In the following description, the start character 102 and the stop character of the one-dimensional barcode and the code position detection pattern (L-type guide cell 111 and cutout symbol 113) of the two-dimensional code are collectively referred to as a code position detection pattern.

  As the two-dimensional code, in addition to the matrix code such as the data code and the QR code, a stack code or the like may be used.

Next, an embodiment of the mark detection processor 13 will be described with reference to FIGS. Note that the coordinate axes on the mask stage 11 in FIGS. 4 to 6 correspond to the coordinate axes in FIGS. 1 and 2.
FIG. 4 is a diagram showing the configuration of a mark detection processor used in the electron beam exposure apparatus according to the first embodiment of the present invention.
The mark detection processor 13 shown in FIG. 4 has a mask identification mechanism (mask identification mark detector 131 and mask identification mark decoder 133) and a mask position detection mechanism (mark detection microscope 132 and mark position detection processing device 134). ing. The mark detection microscope 132 includes an optical system for irradiating the mask identification mark with probe light.

The mask identification mark detector 131 detects the mask identification mark 14 of the mask 10. At this time, the mask stage 11 is moved in the X and Y directions in the drawing so that the mask identification mark 14 is captured within the field of view of the detector 131. As the mask identification mark detector 131, a laser scanning type or a type that photographs a mark with a CCD through a microscope can be used.
The mask identification mark decoder 133 is connected to the detector 131. The mask identification mark decoder 133 decodes the data of the mark 14 read by the detector 131. Thereby, the type (model number etc.) of the mask 10 is identified.

On the other hand, the mark detection microscope 132 irradiates the mask identification mark 14 of the mask 10 with probe light, and acquires an image of the mark 14. At this time, the mask stage 11 is moved in the X and Y directions in the drawing so that the mask identification mark 14 is captured in the field of view of the microscope 132. As the mark detection microscope 132, for example, a type that photographs a mark with a CCD through a microscope can be used.
The mark position detection processing device 134 is connected to the microscope 132. The mark position detection processing device 134 processes the code position detection pattern of the mark image sent from the microscope 132. Thereby, the position of the mask 10 is detected.

  The mark position detection processing device 134 is connected to the stage controller 11a. The position information of the mask 10 obtained above is fed back to the stage controller 11a. The stage controller 11 a controls the mask stage 11 based on the position information of the mask 10 and adjusts the position of the mask 10.

FIG. 5 is a view showing another configuration of the mark detection processor used in the electron beam exposure apparatus according to the first embodiment of the present invention.
The mark detection processor 13 shown in FIG. 5 includes a camera 135, a camera switch 136, a mask identification mark decoder 133, and a mark position detection processor 134.

  The camera 135 includes an optical system, a microscope, and a CCD that irradiate the mask identification mark with probe light. The camera 135 irradiates the mask identification mark 14 of the mask 10 with the probe light, and the CCD identifies the mask identification mark 14 with the CCD through the microscope. Take an image. A camera switch 136 is attached to the camera 135. The camera switch 136 is a switch that switches a device connected to the camera 135. The mask identification mark decoder 133 and the mark position detection processing device 134 are the same as those described in FIG.

Hereinafter, a method of performing mask identification and position measurement using the mark detection processor 13 of this embodiment will be described.
When identifying the mask 10, the camera switch 136 is used to connect the camera 135 and the mask identification mark decoder 133. Then, the mask 10 is identified by decoding the data of the mask identification mark 14 read by the camera 135 by the mask identification mark decoder 133.
On the other hand, when detecting the position of the mask 10, the camera switch 136 is used to connect the camera 135 and the mark position detection processing device 134. Then, the position of the mask 10 is detected by processing the code position detection pattern image of the mask identification mark 14 acquired using the camera 135 by the mark position detection processing device 134.

  The mark position detection processing device 134 is connected to the stage controller 11a. The position information of the mask 10 obtained above is fed back to the stage controller 11a. The stage controller 11 a controls the mask stage 11 based on the position information of the mask 10 and adjusts the position of the mask 10.

  According to the present embodiment, by sharing the camera used for mask identification and mask position measurement, the number of devices constituting the mark detection processor 13 can be reduced, and the exposure apparatus can be reduced in size and space. Can be achieved. In the example of FIG. 4, since there are two detectors (cameras), the mask stage is moved each time a mark is imaged by each detector. However, in this embodiment, the camera is shared. Therefore, there is no need to move the mask stage between mask identification and mask position measurement.

  In the present embodiment, the camera switch 136 in the figure is shown as a mechanical switch, but an electrical switch may be used. Further, as means for switching a device for sending data detected by the camera 135, the optical path of the microscope of the camera 135 is switched in addition to switching the signal from the camera CCD or camera controller using the switch as described above. Means are also conceivable.

FIG. 6 is a view showing another configuration of the mark detection processor used in the electron beam exposure apparatus according to the first embodiment of the present invention.
The mark detection processor 13 shown in FIG. 6 includes a camera 135 and a mark processing device 137.

The camera 135 includes an optical system, a microscope, and a CCD for irradiating the mask identification mark with the probe light, as described with reference to FIG. 5, and irradiates the mask identification mark 14 of the mask 10 with the probe light and passes through the microscope. The mask identification mark 14 is imaged with a CCD.
The mark processing device 137 is connected to the camera 135 and processes data and images of the mark 14 read by the camera 135. That is, in this embodiment, the mask 10 is identified and the position is detected by one apparatus 137.

  The mark processing device 137 is connected to the stage controller 11a. The position information of the mask 10 obtained above is fed back to the stage controller 11a. The stage controller 11 a controls the mask stage 11 based on the position information of the mask 10 and adjusts the position of the mask 10.

  According to the present embodiment, by sharing the mark data and image processing device used for mask identification and mask position measurement, the number of devices constituting the mark detection processor 13 can be reduced, It is possible to further reduce the size and space of the exposure apparatus. Also, there is no need to switch the device connected to the camera.

Next, a second embodiment of the present invention will be described.
The electron beam exposure apparatus of this embodiment has the same configuration as that described with reference to FIG. However, the mask stage 11 (see FIG. 1) of this example includes a mechanism that rotates around the Z axis as it moves in the XY direction.
FIG. 7 is a plan view showing a mask used in the electron beam exposure apparatus according to the second embodiment of the present invention.

  The mask shown in FIG. 7 has substantially the same configuration as the mask shown in FIG. Two mask identification marks 14 are drawn on the lower side of the mechanical stripes 49 of the mask 10 shown in FIG. 7, and two mask identification marks 14 are positioned at rotationally symmetric positions with respect to the center of the mark 14 and the mask 10. A mask position detection mark 17 is drawn. The number and arrangement of the patterns and marks on the mask 10 are merely examples, and are not limited to those shown in FIG.

  The mask identification mark 14 of this embodiment is preferably a mark that can be image processed using an optical microscope and a CCD camera.

  In this embodiment, the mask identification mark 14 is detected to identify the mask, and the mask position detection mark 17 is detected to detect the mask position. These marks are detected by a mark detection processor 13 (see FIG. 1). The mark detection processor 13 of this embodiment has a configuration in which a part of the mechanism for detecting and processing the mask identification mark 14 and the mask position detection mark 17 is shared.

The mark detection processor according to this embodiment will be described below.
FIG. 8 is a diagram showing the configuration of a mark detection processor used in the electron beam exposure apparatus according to the second embodiment of the present invention.
The mark detection processor 13 shown in FIG. 8 includes two cameras 201, two changeover switches 202, a mask identification mark decoder 203, and a mask position detection device 204. The camera 201 includes an optical system that irradiates the mark on the mask with the probe light.

Each camera 201 includes a microscope and a CCD, and images two mask identification marks 14 and two mask position detection marks 17 on the mask 10 with the CCD through the microscope.
A switch 202 is attached to each camera 201. The changeover switch 202 is a switch for changing a device connected to the camera 201.

Hereinafter, a method of performing mask identification and position measurement using the mark detection processor 13 of this embodiment will be described.
When identifying the mask 10, as shown in FIG. 8A, each camera 201 and the mask identification mark decoder 203 are connected using the changeover switch 202. Then, the mask stage 11 is operated to move each mask identification mark 14 within the field of view of each camera 201, and each mark 201 is read by each camera 201. The data of the mask identification mark 14 read by each camera 201 is decoded by the mask identification mark decoder 203. Thereby, the mask 10 is identified.

  When detecting the position of the mask 10, as shown in FIG. 8B, the mask stage 11 is rotated 180 ° to move each mask position detection mark 17 into the field of view of the camera 201. Then, each camera 201 and the mask position detection device 204 are connected using the changeover switch 202, and each mark 17 is imaged by each camera 201. The image of the mark 17 acquired using each camera 201 is processed by the mark position detection device 204. Thereby, the position of the mask 10 is detected.

  The mark position detection device 204 is connected to the stage controller 11a of the exposure apparatus. The position information of the mask 10 obtained above is fed back to the stage controller 11a. The stage controller 11 a controls the mask stage 11 based on the position information of the mask 10 and adjusts the position of the mask 10.

  According to the present embodiment, a microscope and a CCD camera for imaging the mask identification mark 14 and the mask position detection mark 17 can be shared.

  In this example, two cameras 201 are prepared. Thereby, the rotation angle of the mask 10 can be measured at a time. Note that it is not necessary to prepare two cameras 201 in particular, and one camera may be used.

  In the present embodiment, the changeover switch 202 in the figure is shown as a mechanical switch, but an electrical switch may be used. Further, as means for switching a device for sending data detected by the camera 201, a means for mechanically switching the optical path of the microscope of the camera 201 in addition to switching a signal from the camera CCD or camera controller using a switch. Etc. are also conceivable.

It is a schematic diagram which shows the image formation relationship in the whole optical system of the electron beam exposure apparatus (division transfer system) which concerns on the 1st Example of this invention. It is a figure which shows the mask used for the electron beam exposure apparatus which concerns on the 1st Example of this invention. (A) It is the whole top view. (B) It is a partial perspective view. (C) It is a top view of one small membrane area | region. It is a figure which shows the example of a mask identification mark. (A) It is a top view which shows a part of mask identification mark using a one-dimensional barcode. (B) It is a top view which shows the mask identification mark using a data code. (C) It is a top view which shows the mask identification mark using QR code. It is a figure which shows the structure of the mark detection processor used for the electron beam exposure apparatus which concerns on the 1st Example of this invention. It is a figure which shows another structure of the mark detection processor used for the electron beam exposure apparatus which concerns on the 1st Example of this invention. It is a figure which shows another structure of the mark detection processor used for the electron beam exposure apparatus which concerns on the 1st Example of this invention. It is a top view which shows the mask used for the electron beam exposure apparatus which concerns on the 2nd Example of this invention. It is a figure which shows the structure of the mark detection processor used for the electron beam exposure apparatus which concerns on the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electron gun 2, 3 Condenser lens 4 Illumination beam shaping opening 5 Blanking deflector 7 Blanking opening 8 Illumination beam deflector 9 Illumination lens 11 Reticle stage 11a Stage controller 12, 25 Position detector 12a, 25a Interface 13 Mark detection process Device 14 Mask identification mark 15, 19 Projection lens 16 Deflector 18 Contrast aperture 22 Backscattered electron detector 22a Interface 23 Wafer 24 Wafer stage 24a Stage controller 2a, 3a, 5a, 8a, 9a, 15a, 16a, 19a Coil power supply controller 31 Controller 41 Small membrane area 42 Subfield 43 Skirt 44 Electrical stripe 45 Minor strut 47 Major strut 49 Mechanical strike 50 periphery (supporting substrate portion)
14a One-dimensional barcode 101 Quiet zone 102 Start character 103 Character 14b Data code 111 L-type guide cell 112 Data cell 14c QR code 113 Cut-out symbol 114 Data cell 131 Mask identification mark detector 132 Mark detection microscope 133 Mask identification mark decoder 134 Mark position detection processing device 135 Camera 136 Camera switch 137 Mark processing device 17 Mark for mask position detection 201 Camera 202 Changeover switch 203 Mask identification mark decoder 204 Mask position detection device

Claims (6)

An exposure method for transferring a pattern on a mask onto a sensitive substrate while managing a plurality of masks (including a reticle) as a device pattern master,
A mask identification mark for identifying the plurality of masks is attached to the surface of each mask,
An exposure method comprising: detecting a position of the mask identification mark, and performing positioning (alignment) of the mask based on position information of the mark.   2. The exposure method according to claim 1, wherein the mask identification mark is a one-dimensional bar code or a two-dimensional code (stacked code, matrix code, etc.). An exposure apparatus for transferring a pattern on a mask (including a pattern original plate and a reticle) onto a sensitive substrate,
An optical system for irradiating the mask identification mark on the mask with probe light;
Mark detecting means for detecting the position of the mask identification mark by reading light hitting the mask identification mark;
Means for positioning (alignment) the mask by operating a mask stage based on position information of the mask identification mark;
An exposure apparatus comprising: An exposure apparatus for transferring a pattern on a mask (including a pattern original plate and a reticle) onto a sensitive substrate,
An optical system for irradiating the mask identification mark and the mask position detection mark on the mask with probe light;
Mark detection means comprising a detection processing unit that reads the light hitting the mask identification mark and the mask position detection mark and detects the position of the mask identification mark and the mask position detection mark, respectively.
Means for positioning the mask by operating a mask stage based on position information of the mask identification mark and the mask position detection mark;
An exposure apparatus comprising:   5. An exposure apparatus according to claim 4, further comprising a mask moving and rotating means for moving the mark within the field of view of the mark detecting means.   6. The exposure apparatus according to claim 4, wherein the mark detection unit includes a switching unit that switches between a mask identification mark detection processing unit and an alignment mark detection processing unit.

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