JP2011165264A - Transfer object positioning method of double-sided imprint device, and double-sided imprint device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer object positioning method of a double-sided imprint device for positioning a transfer object and upper and lower stampers with high accuracy by use of one camera without providing an alignment mark on the transfer object and to provide the double-sided imprint device. <P>SOLUTION: The center of a rugged pattern formed on a first stamper is aligned with the center of a rugged pattern formed on a second stamper by imaging an alignment mark of the first stamper in a visual field of a camera to obtain a coordinate value of the alignment mark, imaging an edge of a circular opening of the transfer object to obtain a center coordinate value of the transfer object, calculating a deviation value therebetween, further correcting the deviation value to place the transfer object on the first stamper and then imaging an alignment mark of a second stamper via the circular opening of the transfer object. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transfer object positioning method and a double-sided imprint apparatus for a double-sided imprint apparatus, and more specifically, a transfer object (for example, a disk substrate) having a central opening by a stamper (mold) having fine irregularities on the surface. In a double-sided imprinting apparatus that transfers the uneven shape of a stamper to both the front and back sides of a transferred object by applying pressure on the front and back sides, the transferred object (disk substrate) and the upper and lower stampers on the transferred object without providing alignment marks. The present invention relates to a method for positioning a transfer object of a double-sided imprint apparatus and a double-sided imprint apparatus.

  In recent years, semiconductor integrated circuits have been rapidly miniaturized and highly integrated, and pattern transfer technology has been used to meet the fine processing, and photolithography equipment that realizes high-precision pattern transfer technology has been improved. Has been. However, as the microfabrication method approaches the wavelength of light exposure, the lithographic technique has reached its limit. For this reason, an electron beam drawing apparatus, which is a kind of charged particle beam apparatus, has been used as a technique for further miniaturization and higher integration in place of the lithography technique.

Unlike conventional circuit pattern formation using a batch exposure method using a light source such as an i-line or an excimer laser, circuit pattern formation using an electron beam by an electron beam drawing apparatus draws a master pattern individually. Take the method. For this reason, the more patterns to be drawn, the longer it takes for exposure (drawing) and the longer time it takes to form a circuit pattern.
In electron beam drawing, as the miniaturization of patterns and the high degree of integration increase drastically, the circuit pattern formation time is correspondingly increased in series, and there is a concern that the throughput is significantly reduced. Therefore, in order to increase the drawing speed of the electron beam lithography system, the development of a collective figure irradiation method that combines masters of various shapes and irradiates them collectively with an electron beam to form a complex shaped electron beam has recently been developed. Then it is going on. However, this can reduce the size of the pattern, but in addition to the disadvantage that the electron beam drawing apparatus must be enlarged, the cost of the apparatus is increased, such as a mechanism for controlling the master position with higher accuracy. There is a problem of getting higher.

On the other hand, an imprint technique capable of forming a fine pattern at a low cost is currently attracting attention. This is a technique for transferring a predetermined pattern by peeling a stamper after embossing a stamper (mold) having unevenness of the same pattern as a pattern to be formed on a substrate onto the surface of the transfer target. As a result, it is possible to form a fine structure of 25 nm or less on the surface of the transferred material by transfer.
Such an imprint technique is currently under study for application to recording bit formation of a large-capacity recording medium and further to circuit pattern formation in a semiconductor integrated circuit.

When forming a fine pattern on a disk substrate of a large-capacity recording medium or a semiconductor integrated circuit substrate by imprint technology, the stamper is embossed on the resin thin film layer formed on the surface of the transfer object. However, before this embossing, it is necessary to match the relative positions of the stamper (uneven pattern formed on the stamper) and the transfer target with high accuracy. This highly accurate alignment is usually performed by providing an alignment mark for each.
For example, a technique for providing alignment marks on the stamper surface and the surface of the transfer object, and observing the alignment marks of the stamper and the transfer object by an optical method to align the position of the stamper and the transfer object is already known. (Patent Document 1).

However, for example, it may be difficult to provide an alignment mark on the transfer object, such as a disk substrate for a magnetic recording medium.
Therefore, as a method of aligning a disk substrate for a magnetic recording medium without providing an alignment mark on the disk substrate side, for example, a circular opening at the center of the disk substrate (transfer object) and a circular alignment mark of a stamper A method of aligning the center of the stamper (uneven pattern formed on the stamper) and the disk substrate (transfer object) by simultaneously capturing images of the center opening from the position of the end of the center opening by a symmetrical calculation process Is known (Patent Document 2).
Apart from this, as a method of positioning a pair of stampers for double-sided transfer with high accuracy, one stamper has a positioning hole, and the other stamper has a positioning pin that fits into this positioning hole. The technique to provide is also known (patent document 3).

  As shown in each of Patent Documents 1 to 3, the imprint technique uses a stamper by simply positioning a stamper and a disk substrate (transfer object) using a nanometer-level fine pattern using an alignment mark. Although it is currently attracting attention as a technology that can transfer the concavo-convex pattern, there are problems depending on the product to be applied, such as when it is difficult to provide an alignment mark on the transfer target or when it is not preferable to form an alignment mark. Remaining.

JP 2005-116978 A JP 2008-041852 A JP 2009-028996 A

In order to transfer the concavo-convex pattern of the stamper to a predetermined pattern forming region of the transfer target, high-precision alignment between the stamper and the transfer target is required. An optical method is desirable to perform these alignments with high accuracy. However, in general alignment methods, it is necessary to provide alignment marks on both the transfer target and the stamper, or to detect the end position of the transfer target. There is.
Therefore, when transferring a fine pattern on both sides of a transfer object such as a disk substrate of a magnetic disk medium, the upper and lower stampers must be aligned with the transfer object, and the alignment marks and end parts are Prepare a camera that detects the image or prepare a reversing mechanism that reverses the transfer object, aligns one stamper and the transfer object, then reverses the transfer object and aligns it with the other stamper. Processing such as performing is required.
In this respect, since the technique of Patent Document 2 performs single-sided imprinting on a transfer object, it cannot be applied to double-sided imprinting as it is. When the stamper is provided at either one of the upper and lower positions as in Patent Document 2, the reversing mechanism for reversing the disk substrate is required as described above for double-sided imprinting, so that high-precision alignment is achieved. There is a problem that takes time to do. Further, when the upper and lower stampers are provided, the disk substrate and the upper and lower stampers must be aligned respectively.
For example, after obtaining the center position of the disk substrate and aligning one stamper and the disk substrate, the center position of the disk substrate is determined and the other stamper and the disk substrate are aligned. A plurality of cameras for determining the center position of the disk substrate in each of the upper and lower sides are required.

On the other hand, although the technique of Patent Document 3 can position the disk substrate and the pair of stampers with high accuracy, it is necessary to prepare holes on the disk substrate for passing the positioning pins of the stamper. . In addition, the positioning pins provided in each stamper, the positioning holes, and the holes formed on the disk substrate are in mechanical contact. Therefore, the alignment accuracy depends on the accuracy of the hole and the pin, and there is a problem that each contact portion is damaged. As a result, the disk substrate and the stamper may be damaged, and it may be difficult to provide a hole in the disk substrate.
SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the prior art, and to position the transferred object and the upper and lower stampers with high accuracy on the camera table without providing an alignment mark on the transferred object. It is an object of the present invention to provide a method for positioning a transfer object of a double-sided imprint apparatus and a double-sided imprint apparatus.

In order to achieve such an object, the structure of the transferred object positioning method of the double-sided imprint apparatus of the present invention is a translucent first disposed on the front and back surfaces of the transferred object having a circular opening at the center. In a transfer object positioning method of a double-sided imprint apparatus for transferring an uneven pattern formed by each of a first stamper and a second stamper to a transfer object,
The first stamper and the second stamper each have an alignment mark for positioning the transferred object with respect to the concavo-convex pattern, the first stamper is placed on the XY stage, and the camera is located below the first stamper of the XY stage. Is provided,
A transfer object placement step for placing the transfer object chucked by the handling robot at an upper portion separated from the first stamper by a predetermined distance; an image of the alignment mark of the first stamper by the camera; A coordinate value calculating step for obtaining a coordinate value; and an image of the edge of the circular opening of the transferred object by the camera via the first stamper, and the center of the transferred object based on the coordinates of the edge of the circular opening on the field of view of the camera A displacement amount calculating step for calculating a displacement amount with respect to the alignment mark of the first stamper, and a first alignment step for aligning the transferred object with the center of the concave / convex pattern of the first stamper according to the displacement amount. And the chucking by the handling robot was released, and the first alignment step was performed. A transfer object placing step for placing the transfer body on the first stamper, and a camera is placed under the second stamper, and an alignment mark of the second stamper is placed by the camera through the first stamper and the circular opening. And a second alignment step of aligning the center of the transferred object or the center of the concave / convex pattern of the first stamper with the center of the concave / convex pattern of the second stamper based on the coordinates of the alignment mark. It consists of
Further, the double-sided imprinting apparatus of the present invention is in a double-sided imprinting apparatus that uses the transfer object positioning method of the double-sided imprinting apparatus.

As described above, according to the present invention, the alignment mark of the first stamper that is transparent in the field of view of one camera is imaged to obtain the coordinate value of the alignment mark, and the edge of the circular opening of the transfer object is further moved to the first stamper. To obtain the center coordinate value of the transfer object, calculate the shift amount between them, and correct the shift amount and place the transfer object on the first stamper. By imaging the alignment mark of the second stamper through the transparent first stamper and the circular opening of the transferred object, the center of the concave / convex pattern formed on the first stamper or the center of the transferred object is detected. Positioning is performed at the center of the uneven pattern formed on the second stamper.
This makes it possible to position the transfer target and the concave / convex patterns of the upper and lower stampers with high accuracy with a single camera without providing an alignment mark on a subject such as a disk substrate.

FIG. 1 is a schematic explanatory diagram of a double-sided imprint apparatus to which a transfer object positioning method of the double-sided imprint apparatus of the present invention is applied. FIG. 2 is a cross-sectional explanatory diagram of a disk media suction chuck state by the handling robot. FIG. 3A is an explanatory diagram of a shooting state of the alignment point mark of the lower stamper by the alignment camera, FIG. 3B is an explanatory diagram of the captured image, and FIG. 3C is one screen to be captured. It is explanatory drawing of the coordinate value based on a pixel arrangement | sequence. FIG. 4 is a flowchart of the disk media positioning process with respect to the stamper pattern. FIG. 5A is an explanatory diagram for imaging the left edge in the X-axis direction of the central opening of the disc medium, FIG. 5B is an explanatory diagram of the captured image, and FIG. 5C is the right side of the disc media. FIG. 5D is an explanatory diagram for capturing an edge, and FIG. 5D is an explanatory diagram for the captured image. 6A to 6D are explanatory diagrams of the center calculation processing of the disk medium. FIG. 7A is an explanatory diagram for positioning the upper stamper pattern and the lower stamper pattern, FIG. 7B is an explanatory diagram of a captured image of the alignment mark of the upper stamper, and FIG. 7C is an upper stamper. It is explanatory drawing of the center calculation process of a pattern. 8A is a cross-sectional explanatory view of the positional relationship between the alignment mark of the lower stamper, the disk medium, and the alignment mark of the upper stamper, and FIG. 8B is a perspective view of the positional relationship of FIG. FIG.

In FIG. 1, reference numeral 10 denotes a double-sided imprint apparatus, and reference numeral 1 denotes a handling robot for handling a disk medium (transfer object) 2. The handling robot 1 is provided with a lifting / rotating arm 1a.
A suction chuck 1b is suspended from the tip of the lifting / rotating arm 1a, and the lifting / rotating arm 1a is rotatable in a horizontal plane and moves up and down.
Reference numeral 2 denotes a disk medium as a transfer medium having a circular center opening 2a (see FIG. 2) at the center. The center of the center opening 2a usually coincides with the center of the disk medium 2. Therefore, the center of the center opening 2a is calculated as the center of the disk medium 2 below, and the disk medium is positioned with respect to the uneven pattern of the upper and lower stampers.
Normally, a coating device for applying a photocurable resist (photosensitive resin layer) to the disk media 2 is arranged on the left side of the handling robot 1, but this is not shown. Therefore, a resist (photosensitive resin layer) before curing is applied to both the front and back surfaces of the disk medium 2. The handling robot 2 rotates the elevating / rotating arm 1a from the left side to the right side to set the state shown in the figure.
Reference numeral 3 denotes a transparent lower stamper 3. The lower stamper 3 is provided with an alignment point mark (cross mark) 3a corresponding to the center position of the pattern formed on the lower stamper 3. The cross mark 3a is formed as a cross having a size smaller than that of the center opening 2a, as shown in FIG.

FIG. 2 is a cross-sectional explanatory diagram of a state in which the disk media 2 is attracted by the handling robot 1.
The suction chuck 1b vacuum chucks the inner peripheral edge around the central opening 2a of the disk medium 2. Therefore, it has a circumferential groove provided along the inner peripheral edge. As a result, the disk medium 2 is chucked by negative pressure adsorption. Therefore, there is a step between the suction surface 1c of the suction chuck 1b and the side surface 2b of the inner peripheral edge. As a result, the portion of the lower inner peripheral edge 2c protrudes from the suction surface 1c, and this enables imaging of the inner peripheral edge of the disc medium 2.
In order to clarify the outline of the inner peripheral edge 2c, the surface of the suction surface 1c is preferably mirror-finished.
As a result, captured images of inner peripheral edges 2b to 2e around the center opening 2a described later can be obtained by the alignment camera 5.

Returning to FIG. 1, the lower stamper 3 is actually placed on a translucent table such as a glass plate or a quartz plate. This table is fixed to pillars 4a to 4d provided at the four corners of the XY stage 4, and the lower stamper 3 is fixedly mounted on the table so as to be detachable via a clamper. Since this table does not directly relate to this table, a translucent table such as a glass plate or a quartz plate is omitted here and is not shown.
An alignment camera 5 having a focus switching lens mechanism 6 is provided at the center of the XY stage 4 below the center of the lower stamper 3. The alignment camera 5 is an imaging device (camera) in which an imaging element and an illumination light source are integrated. Note that the focus switching lens mechanism 6 has a built-in focus switching lens capable of switching the focus position.

Reference numeral 7 denotes an upper stamper disposed on the upper part of the XY stage 4 when the XY stage 4 moves to the transfer position 4e in the dotted line frame on the right side of the drawing. The Z stage 8 is fixed to an apparatus frame (not shown) via an elevating mechanism 14 and moves up and down.
The upper stamper 7 is provided with a ring-shaped alignment mark (ring mark) 7a on the outer side of the center position of the upper stamper 7 so as to be disposed in a space region that enters the center opening 2a. As shown in FIG. 8 described later, the ring mark 7a is a ring having a diameter smaller than that of the center opening 2a, and the center of the ring mark 7a coincides with the center of the pattern formed in the lower stamper 7.
Similarly to the upper stamper 3, the lower stamper 7 is actually a table made of a glass plate, a quartz plate or the like fixed to support columns 8 a to 8 d provided at four corners of the Z stage 8. However, as described above, the table is omitted. This table need not be translucent like the upper stamper 7.
A guide rail 15 guides the XY stage 4 when it moves in the X-axis direction to the transfer position 4e below the upper stamper 7. As shown in the figure, the X-axis direction corresponds to the left-right direction of the drawing, and the Y-axis direction corresponds to the front-rear direction of the drawing.

Reference numeral 9 denotes a data processing / control device. The data processing / control device 9 includes an MPU 91, a memory 92, an input / output interface 93, a bus 94, and the like, and programs stored in the memory 92 are stored in the MPU 91. Is executed to perform various controls described below.
The memory 92 stores a disk media coarse positioning program 92a, a lower stamper positioning / disk placement program 92b, an upper stamper positioning program 92c, a disk center coordinate calculation program 92d, an edge vertex coordinate calculation program 92e, a transfer program 92f, and the like. A work area 92g and the like are provided.
Reference numeral 11 denotes a drive control circuit which drives the handling robot 1, the XY stage 4, and the Z stage 8 to move to predetermined positions under the control of the data processing / control device 9, respectively.
The handling robot 1 incorporates a movable mechanism that can be moved up and down, and moves the lifting / lowering arm 1 a up and down by driving the drive control circuit 11 to move the chucked disk media 2 to the imaging position of the upper stamper 7. As a result, the inner edge of the disc medium can be photographed at the focus position of the upper stamper 7. Further, the lower stamper 3 is positioned under the upper stamper 7 via the XY stage 4 in a state where the disk medium 2 is placed at the transfer position of the lower stamper 3 by driving of the drive control circuit 11.

Reference numeral 12 denotes an alignment camera control circuit. The alignment camera 5 controls the inner peripheral edge of the disk medium 2, the cross mark 3a of the lower stamper 3, and the ring mark 7a of the upper stamper 7 under the control of the data processing / control device 9. Each image is picked up, and the obtained image (image) for one screen is A / D converted and sent as a digital value to the input / output interface 93 serially.
Reference numeral 13 denotes a focus switching circuit which drives the focus switching lens mechanism 6 under the control of the data processing / control device 9 and performs focus switching for focusing on either the lower stamper 3 side or the upper stamper 7 side. .
The focus switching lens mechanism 6 switches the focus to the mounting position of the upper stamper 7 (height of the upper stamper 7) by loading the lens, and the mounting position of the lower stamper 3 by unloading the lens ( The focus switches to the height of the lower stamper 3).
The focus switching circuit 13 and the focus switching lens mechanism 6 constitute the focus switching mechanism of this embodiment.

3A is an explanatory diagram of a shooting state of the cross mark 3a of the lower stamper by the alignment camera, FIG. 3B is an explanatory diagram of the captured image, and FIG. 3C is one screen to be captured. It is explanatory drawing of the coordinate value based on this pixel arrangement | sequence. FIG. 4 is a flowchart of the disk media positioning process with respect to the stamper pattern.
Hereinafter, the processing for obtaining the coordinate value on the field of view of the cross mark 3a will be described in order with reference to FIGS.
At the start of the disk media positioning interrupt, the disk media coarse positioning program 92a is executed by the MPU 91.
By executing this program, the MPU 91 drives the XY stage 4 to roughly position the XY stage 4 so that the cross mark 3a of the lower stamper 3 enters the center opening 2a of the disk medium 2 chucked by the suction chuck 1b ( At the same time, the height of the disk medium 2 is set to the position of the upper stamper 7 (step 101). The position data of the center of the center opening 2a of the chucked disk medium 2 and the position (height) data of the upper stamper 7 are stored in a parameter area (not shown) of the memory 92. And the process of step 101 is performed.
By the way, since the length of the raising / lowering / rotating arm 1a of the handling robot 1 is constant, the rough positioning in this step 101 is performed by setting the position where the cross mark 3a of the lower stamper 3 enters inside the center opening 2a to the initial position of the XY stage 4. This can correspond to the position. When the XY stage 4 has already been set to the initial position, coarse positioning is not necessary. In this case, the rough positioning in step 101 is a process of simply setting the height of the disk medium 2 to the position of the upper stamper 7.

In the initial state, the focus switching mechanism is unloaded, and the focus position of the alignment camera 5 is adjusted to the position of the lower stamper 3. Therefore, the cross mark 3a is picked up by the alignment camera 5, and the XY coordinate values (X0, Y0) of the cross point of the cross mark 3a are calculated based on the number of pixels picked up on the field of view 5a and stored in the work area 92g of the memory 92. Store (step 102).
FIG. 3A shows a shooting state of the cross mark 3a by the alignment camera 5 at this time. FIG. 3B shows a captured image at this time.
The rectangular frame in FIG. 3A is a one-field visual field 5a imaged by the alignment camera 5, and this visual field 5a has a size of, for example, 1600 × 1200 dots as shown in FIG. 3C. is there. Here, the coordinates of the central pixel position (field center) O which is the center of the field of view 5a of 1600 × 1200 dots are (800, 600).
Note that the origin of the visual field 5a is the coordinates (0, 0) at the upper left corner and the coordinates (1600, 1200) at the lower right.

The XY coordinate values (X0, Y0) of the cross point of the cross mark 3a are calculated after an edge emphasis process since the captured image becomes a grayscale image. Further, when the focus switching mechanism is in a state in which the focus switching lens is loaded, in step 102, the alignment camera 5 is controlled to be unloaded, and then the cross mark 3a is imaged.
Next, the MPU 91 controls the focus switching mechanism, loads the focus switching lens, and switches the focus position of the alignment camera 5 to the position of the upper stamper 7 (step 103).
Here, the execution of the disk media coarse positioning program 92a is finished, and the MPU 91 calls the lower stamper positioning / disk placement program 92b and executes it next.

By executing the lower stamper positioning / disk placement program 92b of the MPU 91, the disk center coordinate calculation program 92d is first called and executed by the MPU 91.
When the disk center coordinate calculation program 92d is executed by the MPU 91, the MPU 91 changes the movement amount of the XY stage 4 from the current position (coarse positioning position) to the radius of the center opening 2a of the disk medium 2 (= D / 2mm) according to this program. (Step 104). However, D is the diameter of the center opening 2a. If the diameter of the center opening 2a is, for example, 12 mmφ, the movement amount in this case shifts the XY stage 4 from the current position (coarse positioning position) to 6 mm.
Next, the MPU 91 sets the movement order of the XY stage 4 for the radius in the order of left side, right side, upper side, and lower side with reference to the rough positioning position (step 105).
Next, the MPU 91 moves the XY stage 4 to the imaging position where the movement amount for the radius is designated (step 106). Initially, the XY stage 4 is shifted from the rough positioning position to the left side.
At this position, the left edge (inner peripheral edge) of the central opening 2a is photographed through the lower stamper 3 to collect the edge image, and the photographed two-dimensional image is stored in the memory 92 of the data processing / control device 9. Is stored in the work area 92g (step 107).
FIG. 5A shows a shooting state at this time. Then, 2b shown in FIG. 5B is an image of the left edge (inner peripheral edge) in the X-axis direction of the central opening 2a imaged at this time.

Next, the MPU 91 calls the edge vertex coordinate calculation program 92e, detects the image coordinates (X1, Y1) of the vertex of the inner peripheral edge in the visual field 5a from the captured image in the work area 92g, and operates the memory 92. Store in the area 92g (step 108).
The image of the inner peripheral edge of the disk medium 2 imaged by the alignment camera 5 here is a grayscale image, and the outline is not sufficiently formed. Therefore, after performing edge emphasis processing as processing of the edge vertex coordinate calculation program 92e to generate an edge contour image, for example, the coordinate values in the X-axis direction are sorted to obtain vertex coordinates (X1, Y1) as the smallest coordinates. Is what you get. The following edge vertex coordinate calculation is the same.
FIG. 6A is an explanatory diagram of image coordinate detection of the vertex of the edge at this time.
In the captured image data of the left inner peripheral edge 2b, the coordinates (X1, Y1) of the pixel position where the X coordinate is located at the leftmost end in the rectangular frame (field of view 5a) are detected as the vertex position of the left inner peripheral edge 2b. .
Then, it is determined whether or not the vertex coordinates of the four inner peripheral edges at the left, right, top and bottom have been detected (step 109). Here, NO is initially determined, so that the process returns to step 105 and the MPU 91 The movement direction is set to the right side in the X axis direction, and in step 106, the XY stage 4 is shifted to the right by Dmm from the left shift position in the X axis direction (step 106). Dmm from the left shift position at this time corresponds to a position D / 2 mm from the current position (coarse positioning position) in step 104.

Next, the alignment camera 5 is controlled by the MPU 91, and the right edge (inner peripheral edge) of the center opening 2 a is photographed through the lower stamper 3 to collect the edge image, and the photographed two-dimensional image is obtained. The data is stored in the work area 92g in the memory 92 of the data processing / control device 9 (step 107).
FIG. 5C shows the shooting state at this time. 2c in FIG. 5D is an image of the right edge (inner peripheral edge) in the X direction of the central opening 2a.
Next, the MPU 91 calls the edge vertex coordinate calculation program 92e, detects the image coordinates (X2, Y2) in the visual field 5a of the vertex of the edge from the photographed image in the work area 92g, and stores it in the work area 92. (Step 108).
FIG. 6B is an explanatory diagram of image coordinate detection of the vertex of the edge at this time.
In the image data of the imaged right inner edge 2c, the coordinates (X2, Y2) of the pixel position where the X coordinate is located at the rightmost end in the rectangular frame (field of view 5a) are detected as the vertex position of the right inner edge 2c. To do. The coordinates (X2, Y2) are obtained as the largest coordinates by sorting the coordinate values in the X-axis direction.

Next, the determination at Step 109 is made, and NO is again determined here, and the process returns to Step 105. In Step 105, the XY stage 4 is returned to the current position (coarse positioning position) at which the cross mark 3a is imaged. The XY stage 4 is shifted upward by D / 2 mm in the Y-axis direction (step 105).
Next, the alignment camera 5 is controlled by the MPU 91, the upper edge (inner peripheral edge) of the center opening 2a is photographed through the lower stamper 3, and the edge image is collected, and the photographed two-dimensional image is obtained. The data is stored in the work area 92g of the memory 92 of the data processing / control device 9 (step 107).
FIG. 6C shows an image captured at this time. 2d is an upper edge (inner peripheral edge) in the Y direction of the central opening 2a.

Next, the MPU 91 calls the edge vertex coordinate calculation program 92e, detects the image coordinates (X3, Y3) in the visual field 5a of the edge vertex from the photographed image in the work area 92g, and works in the work area 92g of the memory 92. (Step 108).
In the captured image data of the upper edge 2d, the coordinate (X3, Y3) of the pixel position where the Y coordinate is located at the uppermost end in the rectangular frame (field of view 5a) is detected as the vertex position of the upper edge 2d. The coordinates (X3, Y3) are obtained as the smallest coordinates by sorting the coordinate values in the Y-axis direction.
Then, the determination in the next step 109 is NO, and the process returns to step 105. In step 105, the MPU 91 shifts the XY stage 4 downward by Dmm in the Y-axis direction (step 105).
Next, the alignment camera 5 is controlled by the MPU 91, the lower edge (inner peripheral edge) of the center opening 2a is photographed through the lower stamper 3, and the edge image is collected, and the photographed two-dimensional image Is stored in the work area 92g in the memory 92 of the data processing / control device 9 (step 107).

FIG. 6D shows an image taken at this time. 2e is a lower edge (inner peripheral edge) in the Y direction of the central opening 2a.
Next, the MPU 91 calls the edge vertex coordinate calculation program 92e, detects the image coordinates (X4, Y4) within the visual field 5a of the vertex of the edge from the photographed image in the work area 92g, and stores it in the work area 92. (Step 108).
In the captured image data of the lower edge 2e, the coordinates (X4, Y4) of the pixel position where the Y coordinate is located at the lowest end in the rectangular frame (field of view 5a) are detected as the vertex position of the lower edge 2e. The coordinates (X4, Y4) are obtained as the largest coordinates by sorting the coordinate values in the Y-axis direction.
Here, the execution of the edge vertex coordinate calculation program 92e is completed, and at this point, the processing of the MPU 91 returns to the lower stamper positioning / disk placement program 92b.
When the four vertex coordinates are calculated in the cycle from step 105 to step 109, the determination in the next step 109 is YES, so the lower stamper positioning / disk placement program 92b is executed, and the MPU 91 Then, the center coordinates of the disc medium 2 on the visual field 5a are calculated.

The calculation of the center coordinates is performed by calculating the shift amounts of the four vertex coordinates from the coordinates (800, 600) of the center pixel position O of the visual field 5a.
The position of the center pixel position O shown in FIGS. 6A and 6B is shifted by 6 mm to the left and right from the rough positioning position, so that in the X-axis direction, 12 mm corresponding to the diameter of the center opening 2a. Has moved. Further, the position of the central pixel position O shown in FIGS. 6C and 6D has moved by 12 mm corresponding to the diameter of the central opening 2a in the Y-axis direction.
Therefore, assuming that the coarse positioning position substantially coincides with the center of the disk medium 2, the positions of the vertex coordinates in the X-axis direction and the Y-axis direction are shown in FIGS. 6 (a) to 6 (d). Should coincide with the coordinates of the central pixel position O. At this time, there is no deviation between the center of the disk medium 2 and the center pixel position O.
This is because the position of the center pixel position O when the XY stage 4 is shifted left and right by 6 mm left and right is on the vertex of the edge of the center opening 2 a having a diameter of 12 mm. Therefore, in FIGS. 6A to 6D, the deviation amount between the center pixel position O and the vertex positions in the X-axis direction and the Y-axis direction is the center of the disk medium 2 with respect to the center pixel position O. It can be calculated as a deviation amount.

If the shift amount of the left inner peripheral edge 2b of the center opening 2a in FIG. 6A with respect to the center pixel position O is ΔX1, ΔX1 = X1−800. Further, if the amount of deviation of the right inner peripheral edge 2c of the center opening 2a in FIG. 6B with respect to the center pixel position O is ΔX2, ΔX2 = X2−800.
Therefore, the amount of deviation ΔX in the X-axis direction from the center pixel position O (field center) is ΔX = (ΔX1 + ΔX2) / 2. That is, in the case of FIG. 6A and FIG. 6B, ΔX1 becomes negative and ΔX2 becomes positive, so half of the difference between ΔX1 and ΔX2 is the shift amount. Such a case is a case where the diameter of the central opening 2a of the disk medium 2 is larger than 12 mm. When the absolute value of ΔX1 is large, the center of the disk medium 2 is shifted to the left side, that is, the negative side. On the other hand, when ΔX2 is large, the center of the disk medium 2 is shifted to the right side, that is, the positive side. Therefore, the deviation of the center of the disk medium 2 from the center pixel position O can be calculated from the average value of these differences.

When the diameter of the central opening 2a is smaller than 12 mm, the left inner peripheral edge 2b in FIG. 6A is on the right side beyond the coordinate 800 of the center pixel position O, and the right inner peripheral edge 2c in FIG. Is on the left side of the center pixel position O less than the coordinate 800. As a result, contrary to the above, ΔX1 becomes positive and ΔX2 becomes negative. Therefore, the center of the disc medium 2 is shifted from the center pixel position O by the average value of these differences.
Further, when the disk medium 2 is shifted to the left side (negative side), the right inner peripheral edge 2c in FIG. 6B is on the left side of the center pixel position O less than the coordinates 800. As a result, both ΔX1 is negative and ΔX2 is negative. Therefore, the center of the disk medium 2 is shifted to the negative side (left side of the drawing) with respect to the central pixel position O by the average value of these sums.
Further, when the disk medium 2 is shifted to the right side (positive side), the right inner peripheral edge 2c in FIG. 6B is on the right side beyond the coordinate 800 of the center pixel position O. As a result, both ΔX1 is positive and ΔX2 is positive. Therefore, the center of the disk medium 2 is shifted to the positive side (right side in the drawing) with respect to the central pixel position O by the average value of these sums.
Here, from the coordinates of the pixel arrangement shown in FIG. 2C, the right side is positive, the left side is negative, the upper side is negative, and the lower side is positive with respect to the center pixel position O.

Similarly, in FIGS. 6C and 6D, the amount of deviation ΔY in the Y-axis direction is the amount of deviation ΔY1 in the Y-axis direction from the center pixel position O in FIGS. 6C and 6D. Assuming ΔY2, ΔY1 = Y3−600 and ΔY2 = Y4−600 are calculated, and the amount of deviation ΔY in the Y-axis direction from the center pixel position O (field center) is ΔY = (ΔY1 + ΔY2) / 2. When the amount of deviation is both positive, the Y-axis direction is the same as the calculation method in the X-axis direction, and only X1 is replaced by Y1 and X2 is replaced by Y2.
Next, the deviation amounts dX and dY between the disk center coordinates and the lower stamper 3 are calculated from the four vertices.
Further, when the shift amounts ΔX and ΔY with respect to the center pixel position O are calculated by ΔX = (ΔX1 + ΔX2) / 2 and (ΔY1 + ΔY2) / 2, the coordinate values (X0, Y0) and deviation amounts ΔdX and ΔdY from the center pixel position O are calculated (step 110).
As a result, the shift amounts dX and dY between the center shift amounts ΔX and ΔY of the disc medium 2 obtained via the center pixel position O and the shift amounts ΔdX and ΔdY of the cross mark 3a are calculated by the following equations. can do.
dX = ΔdX−ΔX
dY = ΔdY−ΔY
Next, the shift amounts dX and dY between the calculated disk center coordinates and the cross mark 3a of the lower stamper 3 are converted into the movement amount of the XY stage 4, and the position of the XY stage 4 is corrected according to the shift amount. The disk center coordinates are aligned with the center of the pattern formed on the lower stamper 3 (step 111).
Next, when the lowering / rotating arm 1a of the handling robot 1 is lowered and the lower surface of the disk medium 2 comes into close contact with the surface of the lower stamper 3, the adsorption of the disk medium 2 by the handling robot 1 is canceled and the upper stamper 3 is moved upward. The disk medium 2 is placed on the (step 112). Then, the MPU 91 calls a positioning program 92c for the upper stamper 7.

The MPU 91 positions the lower stamper 3 and the upper stamper 7 by executing the positioning program 92c for the upper stamper.
7A is an explanatory diagram for positioning the upper stamper pattern and the lower stamper pattern, FIG. 7B is an explanatory diagram of a captured image of the ring mark 7a of the upper stamper 7, and FIG. It is explanatory drawing of the center calculation process of an upper stamper pattern.
Returning to FIG. 1, the MPU 91 moves the XY stage 4 to the dotted line position on the left side of the drawing by executing the positioning program 92 c for the upper stamper, and moves the alignment camera 5 to the reference position below the center of the upper stamper 7. Positioning is performed (step 113).
At this time, the disk medium 2 is placed on the lower stamper 3. Further, the alignment camera 5 is positioned in such a positional relationship that the ring mark 7a of the upper stamper 7 can be imaged through the lower stamper 3 and the central opening 2a of the disk medium 2 by positioning to the reference position.

Then, the MPU 91 photographs the ring mark 7a of the upper stamper 7 through the translucent lower stamper 3 and the central opening 2a of the disk medium 2 (step 114).
At this time, since the focus switching lens is already loaded in step 103 and the focus position of the alignment camera 5 is adjusted to the position of the upper stamper 7, there is no need for focus switching. However, when focus switching is necessary, it is necessary to load the focus switching lens by controlling the focus switching transition.
FIG. 7A shows a state of an image captured by the alignment camera 5 at this time.
FIG. 7B is an image of the ring mark 7a of the alignment camera 5 captured at this time.
The calculation of the center position of the concave / convex pattern of the upper stamper 7 by the ring mark 7a is performed by the MPU 91 calling and executing the edge vertex coordinate calculation program 92e.
The vertexes of the respective edges obtained by dividing the coordinates (Xa, Ya), (Xb, Yb), (Xc, Yc), (Xd, Yd) of each vertex position in the four directions shown in FIG. It calculates by detecting (step 115).
Here, the program returns to the positioning program 92c for the upper stamper, and by executing this program, the MPU 91 determines the center of the ring mark 7a as the intersection of the straight line connecting the left and right vertices and the straight line connecting the upper and lower vertices. The coordinates (Xp, Yp) are calculated (step 116).

Next, a deviation amount between the center coordinates (Xp, Yp) of the upper stamper 7 and the coordinate value of the cross mark 3a of the lower stamper stored in step 102 is calculated (step 117).
The amount of deviation is converted into the amount of movement of the XY stage 4, the position of the XY stage 4 is corrected according to the amount of deviation, and the center of the pattern formed on the lower stamper 3 is the center of the pattern formed on the upper stamper 7. The center is aligned (step 118).
8A is a cross-sectional explanatory diagram of the positional relationship between the cross mark (alignment mark) 3a of the lower stamper 3, the ring mark (alignment mark) 7a of the disk medium 2 and the upper stamper 7, and FIG. FIG. 9 is a perspective explanatory view of the positional relationship of FIG.
As shown in FIG. 8A, the size of the cross mark 3a and the size of the ring mark 7a are both smaller than the central opening 2a of the disc medium 2. Therefore, the respective images are sampled in the field of view 5a of the alignment camera 5 by switching the focus, and the cross mark 3a of the lower stamper 3, the center of the center opening of the disc medium 2, and the ring mark 7a of the upper stamper 7 are aligned. Thus, the concave / convex pattern on the disc medium 2 and the lower stamper 3 and the concave / convex pattern on the upper stamper 7 can be positioned so that the respective positions are aligned.
In step 110, center coordinates are calculated from the coordinates (X1, Y1) to (X4, Y4) of the four vertices on the left, right, top and bottom, and this is calculated as the center coordinates of the disc medium 2. In step 118, The center of the ring mark 7a of the upper stamper 7 may be aligned with this. As shown in the figure, the diameter φb of the central opening 2a, the diameter φa of the ring mark 7a, and the diameter φa due to the length of the cross mark 3a are in a relationship of φb>φa> φa ′.

By the way, as shown in FIG. 8A, the position of the ring mark 7a is different from the position of the cross mark 3a. Therefore, when the disk medium 2 is positioned with respect to the upper stamper 7 (the uneven pattern thereof). The ring mark 7a can be imaged by the alignment camera 5 without the cross mark 3a of the lower stamper 3 getting in the way.
Therefore, when positioning as shown in FIG. 8 is completed, the MPU 91 next calls and executes the transfer program 92f.
As a result, the Z stage 8 is lowered so that the disk medium 2 is sandwiched between the upper stamper 7 and the lower stamper 3 and further pressed to transfer the patterns formed on the respective stampers to the disk medium 2. Is performed (step 119).
Although not shown, each of the XY stage 4 and the Z stage 8 is provided with a UV light source. When the upper and lower stampers are pressed, light is irradiated from the UV light source and the pattern transferred to the disk medium 2 is cured. Then, after the upper stamper 7 is raised, the back side of the disk medium 2 is peeled off from the lower stamper 3 side, and thereafter, the central opening is chucked by the peeling mechanism, and the surface side of the disk medium 2 is peeled off from the upper stamper 7 side. .
In this case, the upper stamper 7 needs to be translucent.

By the way, without adjusting the focus position of the alignment camera 5 in step 102 to the position of the upper stamper 7, the focus switching lens is unloaded from the beginning, and the focus position of the alignment camera 5 is adjusted to the position of the lower stamper 3. You may keep it.
In this case, as step 102, the MPU 91 lowers the raising / lowering / rotating arm 1a of the handling robot 1 to position the disk medium 2 adsorbed within 1 mm above the surface of the lower stamper 3, and first the lower stamper 3 Set focus range.
As a result, the lower surface of the disk medium 2 and the surface of the lower stamper 3 are within the same focus, and the inner peripheral edge of the center opening 2a and the cross mark 3a are arranged at a distance that allows imaging without focus switching. The distance is, for example, a distance of 100 μm to 500 μm. In the rough positioning, the position of the XY stage 4 is set so that the cross mark 3a of the lower stamper 3 is located in the center opening 2a, preferably near the center, and the disk media 2 held by the handling robot 1 is placed on the lower stamper 3. Can be positioned with respect to each other.
Further, when the alignment camera 5 has a large field of view in this way, it becomes possible to simultaneously image the inner peripheral edge of the center opening 2a and the cross mark 3a.
Thereby, in step 106, the left inner peripheral edge 2b and the cross mark 3a of the center opening 2a of the disc medium 2 are simultaneously imaged. In step 109, the right inner peripheral edge 2c of the center opening 2a and the cross mark 3a are simultaneously imaged. be able to. In this way, instead of using the coordinates (800, 600) of the center pixel position O which is the center of the visual field 5a, the coordinate value of the cross mark 3a is directly used as a reference, and the center of the disc medium 2 and the cross mark 3a are used. It is possible to calculate the amount of positional deviation.

As described above, in the embodiment, the cross mark (alignment point mark) 3a is provided on the lower stamper 3 so as to be disposed in the space region that enters the inside of the center opening 2a. Since the mark 3a and the inner peripheral edge of the center opening 2a are imaged independently, if the movement distance of the XY stage when the both are imaged is calculated, it is not necessarily inward from the center opening 2a from the beginning. The cross mark 3a may not be arranged in the space area to be entered.
In the embodiment, the focus switching is performed by having two types of focus switching lenses. However, a camera having two focus positions of the disk medium may be used. Furthermore, the focus position may be switched by having an ascending / descending mechanism of the alignment camera 5.
In the process of converting the shift amount in step 118 of the embodiment into the movement amount of the XY stage 4, the vertex coordinates of the left and right and upper and lower edges of the center opening 2a are calculated when the coordinate value on the visual field of each cross mark 3a is detected. In some cases, the coordinate value on the visual field may be converted into the coordinate value on the XY stage 4 each time, and each shift amount may be calculated in the coordinates on the XY stage 4.
In the embodiment, the edge vertex position calculation program 92e detects the coordinates of the edge vertex positions and calculates the center coordinates of the center opening 2a (disc media 2). However, it corresponds to the vertex position of the center opening 2a. It is also possible to provide four place marks at the place to be performed and calculate the center coordinates of the center opening 2a (disc medium 2) by detecting the mark coordinates.
Further, the disk media 2 in the embodiments include those in which a resin layer is formed on a substrate such as quartz or silicon, and those capable of direct pattern transfer such as a resin substrate or film. Also, the inner peripheral edge of the disc media is a hole in the center of the disc media. The inner edge of the center opening is detected, and the relative position of the disc media and stamper is detected from the detected edge. All you need is a relationship. In the present invention, the lower stamper needs to be a transparent body.

The cross mark 3a and the ring mark 7a of the embodiment need only be at positions where the center coordinates of the concavo-convex pattern formed on the stamper can be calculated, and need not necessarily be provided at positions corresponding to the centers of the stampers. . Furthermore, the cross mark 3a and the ring mark 7a may be any alignment mark as long as the center coordinates of the uneven pattern formed on the stamper can be calculated.
Therefore, in the embodiment, in step 118, the center of the concave / convex pattern of the lower stamper 3 (cross mark 3a) and the center of the concave / convex pattern of the upper stamper 7 are aligned. The center of 2) and the center of the concave / convex pattern of the stamper 7 may be aligned.
Furthermore, in the embodiment, for calculating the disk center coordinates, four vertices are calculated from the image of the inner peripheral edge to calculate the center, but the center position of the circle can be calculated from three points passing on the circumference. Therefore, the moving position may be three points. It is also possible to extract three points from an arc in one photographed image. In calculating the disk center coordinates, it is preferable to calculate the center coordinates by moving the XY stage in three different directions, collecting images of the inner peripheral edge at three locations, obtaining the coordinate values of the vertices at the three points.
Furthermore, although an XY stage is used in the embodiment, there may be an Rθ stage including a rotary stage (θ stage) and a stage (R stage) that moves in the radial direction.
Furthermore, the disk center coordinate calculation program and the edge vertex coordinate calculation program of the embodiment can be processed by providing dedicated arithmetic processing circuit blocks, respectively.

1 ... Handling robot, 2 ... Disc media,
3 ... Lower stamper, 4 ... XY stage,
5 ... Alignment camera, 6 ... Focus switching lens,
7 ... Upper stamper, 8 ... Z stage, 9 ... Data processing / control device,
10: Double-sided imprint apparatus, 11 ... Drive control circuit,
12 ... Alignment camera control circuit,
13: Focus switching circuit,
91 ... MPU, 92 ... memory,
92a ... Disc media coarse positioning program,
92b: Lower stamper positioning / disk placement program,
92c ... Positioning program for the upper stamper
92d ... Disc center coordinate calculation program,
92e ... Edge vertex coordinate calculation program,
92f ... Transcription program,
92g ... work area, 93 ... input / output interface, 94 ... bus.

Claims (8)

Both surfaces for transferring a concavo-convex pattern formed respectively by a first stamper having translucency and a second stamper respectively arranged on the front and back surfaces of a transfer object having a circular opening in the center to the transfer object. In the method for positioning the transfer object of the imprint apparatus,
Each of the first stamper and the second stamper has an alignment mark for positioning the transferred object with respect to the concavo-convex pattern, the first stamper is placed on an XY stage, and the first stamper of the XY stage There is a camera under the stamper,
A transfer object placement step of placing the transfer object chucked by a handling robot at an upper portion away from the first stamper by a predetermined distance;
A coordinate value calculating step of capturing an alignment mark of the first stamper by the camera and obtaining a coordinate value of the alignment mark on a field of view of the camera;
An image of the edge of the circular opening of the transferred object is picked up by the camera through the first stamper, and the center of the transferred object and the first of the transferred object are based on the coordinates of the edge of the circular opening on the field of view of the camera. A deviation amount calculating step for calculating a deviation amount from the alignment mark of the stamper;
A first alignment step of aligning the transferred object and the center of the concave / convex pattern of the first stamper according to the shift amount;
A transferred object placing step of releasing the chuck by the handling robot and placing the transferred object that has been aligned in the first alignment step on the first stamper;
The camera is placed under the second stamper, the alignment mark of the second stamper is picked up by the camera through the first stamper and the circular opening, and the object is detected based on the coordinates of the alignment mark. Transfer of a double-sided imprint apparatus comprising a center of a transfer body or a second alignment step of aligning the center of the concavo-convex pattern of the first stamper with the center of the concavo-convex pattern of the second stamper Body positioning method.   The size of the alignment mark of the first stamper and the alignment mark of the second stamper is smaller than the diameter of the circular opening, and the second stamper is placed on the Z stage, The alignment step is performed by moving the XY stage, and the second alignment step is performed by moving the XY stage and moving the first stamper on which the transfer target is placed on the second XY stage. 2. A method for positioning a transfer object of a double-sided imprint apparatus according to claim 1, wherein the transfer object is positioned under the stamper.   The object to be transferred is a disk medium, the alignment mark of the first stamper is provided at the center position of the concavo-convex pattern formed on the first stamper, and the alignment mark of the second stamper is 3. The transferred object positioning of the double-sided imprint apparatus according to claim 2, wherein the transferred object positioning is formed in a ring shape outside the center position of the second stamper so that the center of the uneven pattern formed on the second stamper can be calculated. Method.   The shift amount calculating step temporarily calculates the shift amount as a shift amount based on the center of the field of view based on the number of pixels in the field of view of the camera, and converts the calculated shift amount into a movement amount of the XY stage. 4. The method for positioning a transfer object of a double-sided imprint apparatus according to claim 3, wherein the shift amount is set to be the shift amount.   The shift amount calculating step includes moving the first stamper in the X-axis direction around the radius of the circular opening by the XY stage, and about half the radius of the circular opening in the Y-axis direction. 5. The double-sided imprint apparatus to be transferred according to claim 4, wherein the center coordinate value is obtained by obtaining the coordinates of three or more vertices on the field of view by imaging the edge portion of the circular opening with the camera. Body positioning method.   The camera includes a focus switching mechanism for focusing on the position of the first stamper and a focus switching mechanism for focusing on the position of the second stamper, and when imaging the alignment mark of the first stamper, 6. The double-sided imprint apparatus according to claim 5, wherein the camera is focused on the position of the first stamper, and when the alignment mark of the second stamper is imaged by the camera, the camera is focused on the position of the second stamper. To be transferred.   The method for positioning a transfer object in a double-sided imprint apparatus according to claim 1, wherein the XY stage is an Rθ stage.   A double-sided imprinting apparatus using the transfer object positioning method for a double-sided imprinting apparatus according to any one of claims 1 to 7.

Images