KR20130108964A - Transfer apparatus and transfer method - Google Patents

Abstract

PURPOSE: A transferring device and a transferring method are provided to perform the pint-fitting of a photographing member based on the result of performing contrast enhancement in respect to images of an alignment mark, thereby enabling the pint-fitting under a bad photographing condition. CONSTITUTION: A transferring device includes a support (BL), a holding unit (3), a photographing unit, an image processing unit, and an alignment unit (42). The support supports a target object to be transferred on boards and a predetermined alignment mark on one surface. The holding member separates the boards from each other and holds the support while the surface of the support faces the board. The photographing member photographs the alignment mark from the other surface of the support via the support. The image processing member detects the alignment mark by image-processing images photographed by the photographing member. The alignment member adjusts the relative positions of the board and the support based on the detected alignment mark. The photographing member includes a focusing device for focusing on the alignment mark.

Description

TRANSFER APPARATUS AND TRANSFER METHOD BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a transfer apparatus and a transfer method for transferring a pattern or a thin film supported on a surface of a carrier to a substrate. In particular, the present invention relates to a technique for aligning a substrate and a carrier based on an imaging result of an alignment mark carried on a carrier.

As a technique for forming a pattern or a thin film on the surface of a substrate, for example, there is known a technique in which a pattern or a thin film as a transfer object is temporarily held on the surface of a flat plate-like carrier (for example, a glass plate) And transferring the transferred object to the surface of the substrate. In such transfer technology, in order to appropriately transfer a transfer object to a predetermined position on the surface of the substrate, alignment processing for aligning the relative position between the carrier and the substrate is required.

An alignment technique that can be used for this purpose is described in, for example, Japanese Patent Application Laid-Open No. 2004-151653. In this technique, alignment marks are formed on the respective surfaces of two substrates to be bonded, and alignment processing is performed based on an image obtained by imaging them (for example, a CCD camera). More specifically, both of the substrates are arranged so that the alignment mark formation surfaces are opposed to each other, and the alignment marks are imaged through the transparent one substrate. Based on the positional relationship of the both alignment marks detected from the captured image, the relative position between the substrates is adjusted. This technique relates to an alignment process for joining two substrates. However, by replacing one substrate with a supporting body, it is possible to achieve a positioning even when the supporting body which carries the transferred object is superimposed on a predetermined position of the substrate and the transferred object is transferred It is a suitably applicable technology.

In such a transfer technique, since the position detection of the alignment mark is performed with high accuracy from the imaging result, it is necessary to match the focus of the imaging means with the alignment mark. However, there are cases where it is difficult to secure a good imaging environment from the optical characteristics and the positional relationship between the substrate, the carrier and the transfer object. For example, the amount of light reflected from the substrate disposed behind the alignment mark changes depending on the material and surface state of the substrate, the distance between the support and the substrate, and thereby the amount of light incident on the imaging means from the alignment mark largely fluctuates . Further, for example, when the alignment mark is formed of the same material as the object to be transferred, the material whose optical property is close to the support may be used as the material.

In this case, it may become difficult to capture the alignment mark with sufficient light quantity and contrast. In particular, in a state in which the focusing is not completed, it is difficult to recognize the alignment mark from the picked-up image itself, and thus, the focusing of the imaging means cannot be performed properly, which causes a problem in the alignment between the substrate and the supporting member. There was a case. In the prior art including the one described in the above-mentioned Patent Document 1, there has been no response to such a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a technique for accurately aligning a substrate and a carrier, even in a case where it is difficult to secure a good imaging environment in a technique of transferring a non- It is aimed to provide the technology that exists.

One aspect of the present invention is a transfer apparatus for transferring a pattern or a thin film as a transfer object to a substrate, in order to achieve the above object, a carrier for supporting the transfer object to be transferred to the substrate and a predetermined alignment mark on one surface thereof. And holding means for keeping the substrate apart from each other and holding the one surface of the carrier facing the substrate, and the carrier from the surface side opposite to the one surface of the carrier. Image pickup means for picking up the alignment mark via the image pickup means, image processing means for detecting the alignment mark from the image picked up by the image pickup means by image processing, the substrate and the carrier on the basis of the detected alignment mark; Alignment means for adjusting a relative position of said imaging means, said imaging means being pinned to said alignment mark And a focus adjusting mechanism for adjusting the focus, and the focus adjusting mechanism performs focusing on the basis of the image of the alignment mark subjected to contrast enhancement processing by the image processing means.

Another aspect of the present invention is a transfer method for transferring a pattern or a thin film as a transfer object to a substrate, in order to achieve the above object, a carrier supporting the transfer object on one surface and a state in which the substrate is separated from each other. The surface of the carrier is further provided by an arranging step in which the one surface of the carrier is disposed to face the substrate, and an imaging means arranged on the surface side opposite to the one surface of the carrier. An image of the alignment mark supported on the image pickup member, and a focusing step of bringing the focus of the imaging means into alignment with the alignment mark based on the result of the imaging, and the state of focusing the focus of the imaging means into the alignment mark. The image of the alignment mark and the substrate-side alignment mark formed on the substrate is imaged, and the image is based on the image pickup result. An alignment step of adjusting a relative position between the substrate and the carrier; and a transfer step of transferring the transfer object from the carrier to the substrate by bringing the substrate and the carrier in close contact with each other. In the focusing step, contrast enhancement processing is performed on an image obtained by photographing the alignment mark, and the alignment mark is detected from the image after the processing.

In the invention constituted as described above, contrast enhancement processing is performed on an image formed by picking up an alignment mark. This makes it easy to detect the alignment mark even when the image contrast is low, for example, due to the insufficient amount of light or the small difference in optical characteristics between the alignment mark and the carrier.

It is feared that contrast emphasis is performed to emphasize the noise included in the imaging result. However, since the shape and size of the alignment mark are known in advance, it is possible to eliminate the influence of noise by reflecting such known information to the detection. In the focusing step, quantitative information such as the position of the alignment mark and the image density thereof is not necessarily required, and it is sufficient to determine whether or not the alignment mark can be stably detected from the image. From this, focusing is performed based on the result of contrast-enhancing the picked-up image, whereby the focusing of the imaging means based on the image of the alignment mark can be satisfactorily performed even in an environment not in a good imaging environment. . Therefore, in this invention, the alignment of a board | substrate and a support body can be performed with high precision based on the image of the alignment mark imaged in the state which the pint was fitted.

In such an invention, for example, the contrast emphasis process including the process of emphasizing the spatial frequency component corresponding to the shape of the alignment mark may be performed. If the alignment mark is clearly displayed on the captured image, the image includes a large amount of spatial frequency components corresponding to the shape of the alignment mark. As described above, since the shape and size of the alignment mark are already known, the spatial frequency component is already known. Therefore, it becomes easier to selectively detect the component corresponding to the alignment mark from the image including the noise component, by performing the process of particularly emphasizing the components, for example, the filter process for extracting the component.

Then, for example, by multiplying the image data of the alignment mark after the filtering process by a coefficient larger than 1, the difference between the signal corresponding to the alignment mark and the noise level is further enlarged to further emphasize the contrast of the alignment mark in the image .

For example, an image of an alignment mark is taken each time while changing and setting the focus position of the imaging means in multiple stages, and the spatial frequency component corresponding to the shape of the alignment mark is most simulated among the images subjected to contrast enhancement processing on the imaging result. You may make it adjust the focus position of an imaging means to the position corresponding to many containing. By doing in this way, the focus position of an imaging means is adjusted to the position which image | photographs an alignment mark most clearly, and image pick-up can be performed in the state in which the focus was matched with the alignment mark in subsequent imaging. As a result, the position detection accuracy of the alignment mark is improved, and alignment of the substrate and the carrier based on the position detection result can be performed with high accuracy.

That is, in this way, the image pickup means picks up the alignment mark supported by the support body, and the board | substrate side alignment mark formed in the board | substrate in the state in which the focus of the imaging means was aligned with the alignment mark. The relative position between the substrate and the carrier is adjusted based on the detection result of the relative position between the alignment mark of the carrier and the substrate-side alignment mark, whereby the alignment between the substrate and the carrier can be performed with high accuracy.

Further, in the above invention, for example, the alignment mark may be formed on the main surface of the support body with the transfer object by the same material as that of the transfer target before the substrate and the carrier are arranged facing each other. In this case, the substrate and the supporting body are aligned based on the alignment mark formed with the transfer object, so that the positional relationship between the transfer object and the substrate can be adjusted with high accuracy. Thereby, the final object of transferring the transferred object to the proper position on the substrate is achieved.

Since the alignment mark is formed of the same material as that of the transfer object, the easy identification of the alignment mark depends on the material of the transfer object. Therefore, although a good contrast may not necessarily be obtained depending on a material, even if it applies in this case, it is possible to perform a focusing suitably in such a case. And based on the image of the alignment mark image | photographed in the state where a pint was fitted in this way, alignment of a board | substrate and a support body can be performed with high precision.

According to the present invention, the focusing of the imaging means is performed on the basis of the result of the contrast emphasis on the image picked up the alignment mark, so that the focusing can be appropriately performed even in a poor imaging environment. And based on the image of the alignment mark imaged in the state in which the focus alignment was performed in this way, in this invention, alignment between a board | substrate and a support body can be performed with high precision.

1 is a perspective view showing a printing apparatus equipped with a transfer apparatus according to the present invention.
Fig. 2 is a diagram schematically showing a cross section of the printing apparatus shown in Fig. 1. Fig.
3 is a block diagram showing an electrical configuration of the apparatus of FIG.
4 is a flowchart showing the overall operation of the printing apparatus of Fig.
5 is a view showing a detailed structure of an alignment stage.
6 is a diagram showing the detailed structure of the imaging unit.
Figs. 7 (a) to 7 (c) are diagrams showing examples of patterns of alignment marks. Fig.
8 is a view showing the arrangement of alignment marks for precise alignment operation.
9 (a) to 9 (c) are views showing an example of an image taken by a CCD camera.
10 is a flowchart showing the flow of processing of the precision alignment operation.
Fig. 11 is a flowchart showing the focus fitting operation.
12 is a diagram showing an example of image data emphasized by contrast.
Figs. 13 (a) and 13 (b) are diagrams for explaining the arrangement of the alignment marks. Fig.

Fig. 1 is a schematic perspective view showing a printing apparatus equipped with a transfer apparatus according to the present invention, and shows a state in which a device cover is removed in order to specify a configuration inside the apparatus. Fig. 2 is a diagram schematically showing a cross section of the printing apparatus shown in Fig. 1. Fig. 3 is a block diagram showing an electrical configuration of the apparatus of FIG. The printing apparatus 100 is configured such that the upper surface of the blanket brought into the apparatus from the front side of the apparatus is adhered to the lower surface of the plate (PP) brought into the apparatus from the left side of the apparatus, A pattern layer is formed by patterning the coating layer on the blanket by a pattern formed on the lower surface of the substrate PP (patterning processing). Further, the printing apparatus 100 separates the pattern layer formed on the blanket by peeling the upper surface of the patterned blanket against the lower surface of the substrate SB loaded into the apparatus from the right side of the apparatus, (Transferring process). 1 and the subsequent drawings, the conveying direction of the plate PP and the substrate SB is referred to as the " X direction " in order to clarify the arrangement relationship of the respective units of the apparatus, The horizontal direction from the right side to the left side will be referred to as "+ X direction", and the reverse direction will be referred to as "-X direction". Of the horizontal directions orthogonal to the X direction, the front side of the apparatus is referred to as a "+ Y direction" and the back side of the apparatus is referred to as "-Y direction". The upward and downward directions in the vertical direction are referred to as "+ Z direction" and "-Z direction", respectively.

In this printing apparatus 100, the apparatus parts (the carrying unit 2, the upper stage unit 3, the alignment unit 4, the lower stage unit 5, A pressing section 7, a pre-aligning section 8, and a discharging section 9), and the control section 6 controls each section of the apparatus.

The conveyance part 2 is an apparatus which conveys the board PP and the board | substrate SB to an X direction, and is comprised as follows. In this carry section 2, two brackets (not shown) are erected from the right rear corner and the left rear corner of the upper face of the stone basin 1. The ball screw mechanism 21 is extended in the lateral direction, that is, in the X direction so as to connect the upper ends of the two brackets to each other. In the ball screw mechanism 21, a ball screw (not shown) extends in the X direction, and a rotary shaft (not shown) of a motor M21 for shuttle horizontal driving is connected to one end of the ball screw mechanism. A ball screw bracket (not shown) is screwed to the center of the ball screw, and a shuttle holding plate 22 extending in the X direction with respect to the (+ Y) side surface of the ball screw bracket is mounted.

The plate shuttle 23L is provided so as to be movable up and down in the vertical direction Z on the (+ X) side end of the shuttle holding plate 22 while the shuttle 23R for the board is provided in the Z). Since the shuttles 23L and 23R have the same configuration except for the rotation mechanism of the hand, the configuration of the plate shuttle 23L will be described here, and the same reference numerals And a description thereof will be omitted.

The shuttle 23L is provided with a lifting plate 231 and a (+ X) side end portion of the lifting plate 231 and a (-X) side end portion of the lifting plate 231 which are approximately equal to or slightly longer than the width size And two plate hands 232 and 232 extending from the side end portions to the front side, i.e., the (+ Y) side, respectively. The elevating plate 231 is attached to the (+ X) side end of the shuttle holding plate 22 so that the elevating plate 231 can be elevated by a ball screw mechanism (not shown). That is, the ball screw mechanism is extended in the vertical direction Z with respect to the (+ X) side edge part of the shuttle holding plate 22. At the lower end of the ball screw mechanism, a rotating shaft (not shown) is connected to the plate shuttle lift motor M22L (FIG. 3). Further, a ball screw bracket (not shown) is screwed to the ball screw mechanism, and a lifting plate 231 is attached to the (+ Y) side surface of the ball screw bracket. For this reason, the plate shuttle elevating motor M22L operates in accordance with the operation instruction from the motor control unit 63 of the control unit 6, and the elevating plate 231 is driven up and down in the vertical direction Z.

The size of the front and back sides (Y direction size) of each of the hands 232 and 232 is longer than the length size (Y direction size) of the plate PP and the length of the plate PP from the front end side (+ Y side) And the like.

In order to detect that the plate PP is held by the plate hands 232 and 232 in this way, a plate sensor (not shown) is attached to the (+ Y) side from the center of the lifting plate 231 through the sensor bracket Respectively. Therefore, when the plate PP is placed on both hands 232, the sensor detects the rear end of the plate PP, that is, the end on the (-Y) side, and outputs a detection signal to the control unit 6.

Each of the plate hands 232 and 232 is mounted on the lifting plate 231 via a bearing (not shown) and is rotatable about a rotational axis extending in the front-rear direction (Y direction) as a rotational center. Further, rotary actuators RA2 and RA2 (FIG. 3) are attached to both ends of the elevating plate 231 in the X direction. These rotary actuators RA2 and RA2 operate by using pressurized air as a driving source and are rotatable in units of 180 degrees by opening and closing valves (not shown) interposed in the supply path of the pressurized air. Therefore, by controlling the opening and closing of the valve by the valve control section 64 of the control section 6, one main surface of the plate hand 232, 232 is moved upwards in the hand posture ( (Hereinafter referred to as the "unused posture") and a hand posture suitable for handling the plate PP after patterning with the other main surface facing upward (hereinafter referred to as "used posture"), It is possible to switch the posture. The fact that the plate shuttle 23L is unique to the board shuttle 23R in that it has a mechanism for switching the hand posture as described above.

Next, the mounting positions of the plate shuttle 23L and the substrate shuttle 23R with respect to the shuttle holding plate 22 will be described. 2, the plate shuttle 23L and the substrate shuttle 23R are provided on the plate PP and the substrate SB in a widthwise dimension (in the embodiment, the plate PP and the substrate SB SB) are spaced apart from each other in the X direction by an interval longer than the width of the shuttle retaining plate 22. Then, when the rotation axis of the shuttle horizontal drive motor M21 is rotated in the predetermined direction, both shuttles 23L and 23R move in the X direction while maintaining the separation distance. For example, in Fig. 2, reference numeral XP23 denotes a position immediately below the upper stage portion 3, and the shuttles 23L and 23R are spaced equidistantly from the position XP23 in the (+ X) Quot; step movement unit "). In the present embodiment, the state shown in Fig. 2 is referred to as " intermediate position state ".

When the shuttle holding plate 22 is moved in the (+ X) direction by rotating the rotation axis of the shuttle horizontal drive motor M21 in the predetermined direction from the intermediate position state, the shuttle 23R for the substrate is moved in the + X ) And moves to a position XP23 immediately below the upper stage part 3 to be positioned. At this time, the plate shuttle 23L integrally moves in the (+ X) direction and is positioned at the position XP21 close to the plate cleaning apparatus (not shown) arranged on the (+ X) direction side of the printing apparatus 100.

Conversely, when the shuttle holding plate 22 is rotated in the -X direction by the stepwise movement unit by rotating the rotation axis of the shuttle horizontal drive motor M21 in the direction opposite to the predetermined direction, the plate shuttle 23L is moved to the intermediate position state (-X) direction and moves to a position XP23 immediately below the upper stage part 3 and is positioned. At this time, the substrate shuttle 23R also moves integrally (-X) and moves to the position XP25 close to the substrate cleaning apparatus (not shown) disposed on the (-X) side of the printing apparatus 100 . Thus, in this specification, five positions (XP21 to XP25) are defined as the shuttle positions in the X direction. That is, the plate delivering position XP21 is the position closest to the plate cleaning apparatus among the three positions XP21 to XP23 at which the plate shuttle 23L is positioned, Direction position in which the carry-in / out is performed. The substrate transfer position XP25 is the position closest to the substrate cleaning apparatus among the three positions XP21 to XP25 at which the substrate shuttle 23R is positioned and the transfer position of the substrate SB And the X direction position in which the ejection is performed. The position XP23 indicates the X-direction position in which the adsorption plate 34 of the upper stage unit 3 moves in the vertical direction Z to adsorb and hold the plate PP and the substrate SB. In the present specification, when the plate shuttle 23L is located at the X-direction position XP23, the position XP23 is referred to as "plate suction position XP23", while the shuttle 23R for the substrate is positioned at the X- Quot; substrate suction position XP23 ", the position XP23 is referred to as " substrate suction position XP23 ". The position in the vertical direction Z for conveying the plate PP and the substrate SB by the shuttles 23L and 23R in this way, that is, the height position is referred to as a " transport position ".

In this embodiment, in order to precisely control the amount of gap between the plate PP and the blanket at the time of patterning and the amount of gap between the substrate SB and the blanket at the time of transferring, It is necessary to measure the thickness of the substrate SB. Therefore, a plate thickness measurement sensor SN22 and a substrate thickness measurement sensor SN23 are provided. In the present embodiment, a reflection type optical sensor having a transparent portion and a light receiving portion is used as both of the sensors SN22 and SN23, but other sensors may be used.

In the position XP23, the upper stage portion 3 is arranged. A ball screw mechanism 31 extending in the vertical direction Z is fixed to the upper stage portion 3. A ball screw mechanism 31 is fixed to an upper end portion of the upper stage portion 3 by a rotation shaft of the first stage elevating motor M31 (Not shown). Then, a ball screw bracket (not shown) is screwed onto the ball screw mechanism 31. The ball screw bracket is fixed to the support frame 32 and is capable of being raised and lowered in the vertical direction Z integrally with the ball screw bracket. Further, on the frame surface of the support frame 32, another ball screw mechanism (not shown) is supported. The ball screw mechanism is provided with a ball screw having a pitch narrower than that of the ball screw of the ball screw mechanism 31, and a rotational shaft (not shown) of the second stage elevating motor M32 (FIG. 3) And a ball screw bracket is screwed on the center portion.

The stage holder 33 is attached to this ball screw bracket. Further, on the bottom surface of the stage holder 33, for example, an adsorption plate 34 made of metal such as aluminum alloy is attached. Therefore, the stage lifting motors M31 and M32 are operated in accordance with an operation command from the motor control unit 63 of the control unit 6, so that the suction plate 34 is moved up and down in the vertical direction Z. In this embodiment, the first stage lifting motor M31 is operated by combining the ball screw mechanisms having different pitches to move the attracting plate 34 for moving the attracting plate 34 at a relatively wide pitch at high speed . In addition, it is possible to raise and lower the adsorption plate 34 at a relatively narrow pitch, that is, to precisely locate the adsorption plate 34 by operating the second stage lifting motor M32.

An adsorption mechanism is provided on the lower surface of the adsorption plate 34, that is, the adsorption surface for adsorbing and holding the plate PP and the substrate SB, and is connected to a negative pressure supply source through a negative pressure supply path. 3) connected to the adsorption mechanism in accordance with the opening and closing command from the valve control unit 64 of the control unit 6 is controlled to open and close the plate PP and the substrate SB by the adsorption mechanism Adsorption becomes possible. Further, in the present embodiment, the adsorption mechanism and the adsorption mechanism for adsorbing and holding the blanket as described later use the power of the factory as a negative pressure supply source. However, when the apparatus 100 is equipped with a negative pressure supply portion such as a vacuum pump And a negative pressure may be supplied to the adsorption mechanism from the negative pressure supply part.

In the upper stage unit 3 constructed as described above, the plate is moved from the left side of FIG. 1 to the plate suction position XP23 immediately below the upper stage unit 3 through the carrying space by the plate shuttle 23L of the carry unit 2 , The adsorption plate 34 of the upper stage portion 3 is lowered to adsorb and hold the plate PP. Conversely, when the adsorption plate 34 adsorbing the plate PP with the plate shuttle 23L positioned just below the upper stage portion 3 releases the adsorption, the plate PP is conveyed to the conveying portion 2, And is mounted on the carriage. In this manner, the plate is exchanged between the carry section 2 and the upper stage section 3. [

The substrate SB is also held on the upper stage portion 3 in the same manner as the plate PP. That is, after the substrate SB is transported from the right side of FIG. 1 to the position immediately below the upper stage portion 3 through the transport space by the substrate shuttle 23R of the carry section 2, 3) is lowered to adsorb and hold the substrate SB. On the other hand, when the suction plate 34 of the upper stage portion 3, which has attracted the substrate SB with the substrate shuttle 23R positioned just below the upper stage portion 3, releases the adsorption, SB are moved and placed on the carry section 2. Thus, the transfer of the substrate SB is carried out between the transfer section 2 and the upper stage section 3.

The alignment portion 4 is arranged on the upper surface of the stone tablet 1 in the vertical direction below the upper stage portion 3 (hereinafter referred to as " vertical lower portion " In this alignment section 4, the support plate 41 is arranged in a horizontal posture so as to overrun the recess of the stone basin 1 as shown in Fig. 1, and is fixed to the upper surface of the stone basin 1. In addition, the alignment stage 42 is fixed to the upper surface of this support plate 41. The lower stage part 5 is placed on the alignment stage 42 of the aligning part 4 so that the upper surface of the lower stage part 5 faces the attracting plate 34 of the upper stage part 3 . The upper surface of the lower stage portion 5 is capable of adsorbing and holding the blanket BL and the blanket BL on the lower stage portion 5 is positioned with high precision by controlling the alignment stage 42 by the control portion 6. [ It is possible to decide.

The alignment stage 42 includes a stage base 421 fixed on the support plate 41 and a stage top disposed on the upper side of the stage base base 421 to support the lower stage unit 5, (422). Both the stage base 421 and the stage top 422 have a frame shape with a passage at the center. Between the stage base 421 and the stage tower 422, there are provided, for example, a cross roller bearing having three degrees of freedom in the X and Y directions, a rotational direction about the rotational axis extending in the vertical direction Z, And the like are disposed in the vicinity of the corners of the stage tower 422. [ A ball screw mechanism (not shown) is provided for each support mechanism 423, and a stage drive motor M41 (Fig. 3) is attached to each ball screw mechanism. By operating each stage drive motor M41 in accordance with an operation command from the motor control unit 63 of the control unit 6, a relatively large space is provided at the center of the alignment stage 42, and the stage top 422 Move in the horizontal plane. Further, the adsorption plate 51 of the lower stage portion 5 can be positioned by rotating the vertical axis about the rotation center. One of the reasons for using the alignment stage 42 having a hollow space in the present embodiment is that the blanket BL held on the upper surface of the lower stage portion 5 and the blanket BL held on the lower surface of the upper stage portion 3 And the alignment mark formed on the substrate SB to be held is picked up by the image pickup section 43.

The lower stage portion 5 has an attracting plate 51, a column member 52, a stage base 53, and a lift pin portion 54. In the stage base 53, three long-hole-shaped passageways extending in the left-right direction (X) are provided side by side in the front-back direction (Y). The stage base 53 is fixed on the alignment stage 42 so that the long hole passage and the central passage of the alignment stage 42 overlap from above in a plan view. A part of the imaging section 43 is loosely inserted into the long hole passage. The column member 52 is placed in the (+ Z) from the upper surface corner of the stage base 53, and the top portion supports the adsorption plate 51.

This adsorption plate 51 is comprised from metal plates, such as aluminum alloy, for example. On the upper surface of the adsorption plate 51, an adsorption mechanism (not shown) is provided. One end of a positive pressure supply pipe (not shown) is connected to the adsorption mechanism, and the other end is connected to the pressurizing manifold. In addition, a pressurization valve V51 (Fig. 3) is inserted into the intermediate portion of each of the static pressure supply pipes. The pressurizing manifold is constantly supplied with air at constant pressure obtained by regulating the pressurized air supplied from the power of the factory with a regulator. Therefore, when a desired pressurization valve V51 is selectively opened in accordance with an operation command from the valve control unit 64 of the control unit 6, the pressurized pressurized air is supplied to the adsorption mechanism connected to the selected pressurization valve V51 .

Further, not only a selective supply of pressurized air but also selective negative pressure supply is possible for a part of the adsorption mechanism. That is, one end of a negative pressure supply pipe (not shown) is connected to each of the specific adsorption mechanisms, and the other end is connected to the negative pressure manifold. In addition, an adsorption valve V52 (Fig. 3) is inserted into the intermediate portion of each negative pressure supply pipe. The negative pressure supply manifold is connected to the negative pressure manifold through a regulator, so that a predetermined negative pressure is always supplied. Therefore, when a desired suction valve V52 is selectively opened in accordance with an operation command from the valve control unit 64 of the control unit 6, a regulated negative pressure is supplied to the suction mechanism connected to the selected suction valve V52 do.

As described above, in the present embodiment, the blanket BL is partially or wholly adsorbed on the adsorption plate 51 by the opening and closing control of the valves V51 and V52, or the adsorption plate 51 and the blanket BL So that the blanket BL can be partly inflated so as to be pressed against the plate PP or the substrate SB held on the upper stage portion 3.

In the lift pin portion 54, a lift plate 541 is provided so as to be able to move up and down between the attraction plate 51 and the stage base 53. In this lift plate 541, cutouts are formed in a plurality of places, and interference with the imaging unit 43 is prevented. Further, a plurality of lift pins 542 are vertically arranged above the upper surface of the lift plate 541. On the other hand, the pin lowering cylinder CL51 (FIG. 3) is connected to the lower surface of the lift plate 541. The valve control unit 64 of the control unit 6 switches the opening and closing of the valve connected to the pin lifting cylinder CL51 so that the pin lifting cylinder CL51 is operated to lift and lift the lift plate 541. [ As a result, the entire lift pins 542 move back and forth with respect to the upper surface, i.e., the adsorption surface, of the adsorption plate 51. For example, the lift pin 542 protrudes in the (+ Z) direction from the upper surface of the attracting plate 51, so that the blanket transport robot moves the blanket BL to the top of the lift pin 542 It becomes possible to put it. Then, following the mounting of the blanket BL, the lift pin 542 is retracted in the -Z direction from the upper surface of the attracting plate 51, so that the blanket BL is moved and placed on the upper surface of the attracting plate 51 . Thereafter, the thickness of the blanket BL is measured by a blanket thickness measurement sensor SN51 (Fig. 3) disposed in the vicinity of the adsorption plate 51 at an appropriate timing as will be described later.

As described above, in the present embodiment, the upper stage portion 3 and the lower stage portion 5 are disposed opposite to each other in the vertical direction Z. Between them, a pressing portion 7 for pressing the blanket BL to be placed on the lower stage portion 5 from above, and a pressing portion 7 for pressing the plate PP, the substrate SB and the blanket BL alignment section 8 for performing alignment (alignment).

The pressing portion 7 is capable of switching to the two states by raising and lowering the pressing member 71 provided on the vertically upper side of the adsorption plate 51 in the vertical direction Z by a switching mechanism (not shown). That is, when the switching mechanism lowers the pressing member 71, the blanket BL on the suction plate 51 is pressed by the pressing portion 7 (blanket pressing state). On the other hand, when the switching mechanism raises the pressing member 71, the pressing portion 7 is separated from the blanket BL to release the pressing of the blanket BL (blanket pressing released state).

In the prealignment section 8, the prealignment upper section 81 and the prealignment lower section 82 are stacked in two stages in the vertical direction Z. Of these, the prealignment upper portion 81 is arranged on the vertically upper side than the prealignment lower portion 82 and is held at the position XP23 by a plate PP (not shown) held by the plate shuttle 23L before the close contact with the blanket BL. And the substrate SB held by the shuttle for substrate 23R. On the other hand, the pre-alignment lower side 82 aligns the blanket BL to be placed on the suction plate 51 of the lower stage portion 5 prior to the close contact with the plate PP or the substrate SB. The prealignment upper portion 81 and the prealignment lower portion 82 have basically the same configuration. Therefore, in the following, the configuration of the prealignment upper portion 81 will be described, and the same reference numerals will be given to the prealignment lower portion 82, and the description of the components will be omitted.

In the pre-alignment upper portion 81, four upper guides 812 are movably provided with respect to the frame-shaped frame structure 811. That is, the frame structure 811 includes two horizontal frames separated from each other in the left-right direction X and extending in the front-rear direction Y, and two horizontal frames extending in the left- It is a combination of two horizontal frames. 2, an upper guide 812 at a central portion of the left horizontal plate of the two horizontal plates extending in the front-rear direction Y is supported by a ball screw mechanism (not shown) in the lateral direction X As shown in Fig. The upper guide 812 is moved in the left-right direction X by operating the drive motor M81 (Fig. 3) connected to the ball screw mechanism in accordance with an operation command from the motor control unit 63 of the control unit 6 do. Similarly to the above, the upper guide 812 is configured to move in the left-right direction X by the drive motor M81 with respect to the right-side horizontal plate.

The upper guide 812 is configured to move in the left-right direction X by the drive motor M81 in the same manner as described above for each of the two horizontal plates extending in the forward and backward directions Y. [ In this manner, the four upper guides 812 surround the plate PP and the substrate SB at the vertically lower position of the position XP23, and each of the upper guides 812 is independent of the plate PP, It is possible. Therefore, by controlling the amount of movement of each upper guide 812, the plate PP and the substrate SB can be aligned horizontally or rotated on the hand of the shuttle.

In this embodiment, as described later, the pattern layer on the blanket (BL) is transferred to the substrate (SB), the blanket (BL) is separated from the substrate (SB) Occurs. Further, static electricity is generated even when the coating layer on the blanket (BL) is patterned by the plate (PP) and then the blanket (BL) is peeled from the plate (PP). Therefore, in this embodiment, the electrostatic discharge portion 9 is provided for discharging static electricity. The discharger 9 has an ionizer 91 for irradiating ions from the (+ X) side toward the spaces sandwiched between the upper stage portion 3 and the lower stage portion 5.

The control unit 6 has a CPU (Central Processing Unit) 61, a memory 62, a motor control unit 63, a valve control unit 64, an image processing unit 65, and a display / operation unit 66, 61 control the respective units of the apparatus in accordance with a program stored in advance in the memory 62 to execute the patterning processing and the transfer processing as shown in Fig.

4 is a flowchart showing the overall operation of the printing apparatus of Fig. In the initial state of the printing apparatus 100, the plate shuttle 23L and the substrate shuttle 23R are positioned at the intermediate positions XP22 and XP24, respectively. Then, the plate PP is inserted (step S1) in synchronization with the conveying operation of the plate PP by the plate conveying robot (not shown) of the plate washing apparatus, and the substrate carrying robot (Step S2) of the substrate SB in synchronization with the conveying operation of the substrate SB of the substrate SB. Since the plate transfer shuttle 23L and the substrate shuttle 23R are integrally moved in the left and right directions X, the substrate SB (Step S2), but the order of both of them may be changed.

As described above, in this embodiment, not only the plate PP but also the substrate SB are prepared before the patterning process is executed, and the patterning process and the transfer process are successively performed as will be described later in detail. Thereby, the time interval until the coated layer patterned on the blanket BL is transferred to the substrate SB can be shortened, and stable processing is performed.

In the next step S3, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the -X direction. Thereby, the plate shuttle 23L is moved to the plate suction position XP23 and positioned. Then, the plate shuttle elevating motor M22L rotates the rotating shaft to move the lifting plate 231 in the downward direction (-Z). Thus, the plate PP is moved to and positioned at a prealignment position lower than the conveying position while being supported by the plate shuttle 23L.

Next, the upper guide drive motor M81 is operated to move the upper guide 812, and each upper guide 812 comes into contact with the end face of the plate PP supported by the plate shuttle 23L, (PP) is positioned at a preset horizontal position. Thereafter, each upper guide drive motor M81 operates in the reverse direction, and each upper guide 812 is separated from the plate PP. When the pre-alignment processing of the plate PP is completed in this manner, the stage elevating motor M31 rotates the rotation shaft in the predetermined direction to lower the adsorption plate 34 in the downward direction (-Z) To the surface. Subsequently, the valve V31 is opened, whereby the plate PP is adsorbed to the adsorption plate 34 by the adsorption mechanism for the upper stage.

When the adsorption of the plate PP is completed in this way, the stage elevating motor M31 rotates in the reverse direction, and the adsorption plate 34 is lifted up vertically upward while adsorbing and holding the plate PP, To the vertically upper position of the plate PP. Then, the plate shuttle elevating motor M22L rotates the rotating shaft to move the elevating plate 231 vertically upward to move the plate shuttle 23L from the prealignment position to the conveying position, that is, the plate suctioning position XP23 Position. Thereafter, the shuttle horizontal drive motor M21 rotates the rotating shaft to move the shuttle holding plate 22 in the (+ X) direction, and positions the empty shuttle 23L at the intermediate position XP22.

In the next step S4, the stage drive motor M41 is operated to move the alignment stage 42 to the initial position. Thus, each departure is made to the same position. Subsequently, the pin lifting cylinder CL51 is operated to lift the lift plate 541 so that the lift pin 542 protrudes vertically upward from the upper surface of the attracting plate 51. After the blanket transport robot has thus accessed the apparatus 100 and placed the blanket BL on the top of the lift pin 542 in the manner described above, . Next, the pin lifting cylinder CL51 is operated to lower the lift plate 541. [ Thereby, the lift pin 542 is lowered while supporting the blanket BL, and the blanket BL is placed on the attracting plate 51. Then, the lower guide drive motor M82 is operated so that the lower guide 822 moves, and the lower guide 822 abuts against the end face of the blanket BL supported by the suction plate 51 so as to contact the blanket BL. Position it at the preset horizontal position. When the prealignment process of the blanket BL is completed in this manner, the suction valve V52 is opened so that the regulated negative pressure is supplied to the suction mechanism for the lower stage so that the blanket BL is moved to the suction plate 51, . Moreover, each lower guide drive motor M82 rotates a rotating shaft to the reverse direction, and separates each lower guide 822 from the blanket BL. Thus, the preparation of the patterning process is completed.

In the next step S5, the sensor horizontal drive cylinder CL52 (FIG. 3) is operated to position the blanket thickness measurement sensor SN51 at a position immediately above the right end of the blanket BL. The blanket thickness measurement sensor SN51 outputs information relating to the thickness of the blanket BL to the control unit 6, whereby the thickness of the blanket BL is measured. Next, the sensor horizontal drive cylinder CL52 operates in the reverse direction to retract the blanket thickness measurement sensor SN51 from the adsorption plate 51. [

Next, the first stage elevating motor M31 rotates the rotating shaft in a predetermined direction to lower the attracting plate 34 in the downward direction (-Z) to move the plate PP in the vicinity of the blanket BL. The second stage lifting motor M32 rotates the rotating shaft to move the attracting plate 34 up and down at a narrow pitch so that the distance between the plate PP and the blanket BL in the vertical direction Z, Adjust. This gap amount is determined by the control section 6 based on the results of the thickness measurement of the plate PP and the blanket BL.

Then, the pressing member 71 of the pressing portion 7 is lowered, and the peripheral portion of the blanket BL is pressed against the pressing member 71 over the entire circumference. Subsequently, the valves V51 and V52 operate to partially supply air between the adsorption plate 51 and the blanket BL to partially blow the blanket BL. This floating portion is pressed against the plate PP held by the upper stage portion 3. As a result, a central portion of the blanket BL is brought into close contact with the plate PP, and a pattern (not shown) previously formed on the lower surface of the plate PP is brought into contact with a coating layer previously applied on the upper surface of the blanket BL, Is patterned to form a pattern layer.

In the next step S6, the second stage elevating motor M32 rotates the rotating shaft to raise the adsorption plate 34 to peel the plate PP from the blanket BL. The valves V51 and V52 are opened and closed in a timely manner at the same time as the plate PP is lifted to perform the peeling process so that a negative pressure is applied to the blanket BL and pulled toward the adsorption plate 51 . Thereafter, the first stage elevating motor M31 rotates the rotating shaft to raise the attracting plate 34 to position the plate PP at the discharge position at almost the same height as the ionizer 91. [ Further, the pressing member 71 of the pressing portion 7 is raised to release the pressing portion of the blanket BL. Subsequently, the ionizer 91 operates to discharge static electricity generated during the peeling process. When the static elimination process is completed, the first stage elevating motor M31 rotates the rotation shaft to hold the plate PP while holding the adsorption plate 34 up to the initial position (position higher than the plate suction position XP23) Rise.

In the next step S7, the rotary actuators RA2 and RA2 are operated, and the plate hand 232, 232 is rotated by 180 degrees to be positioned at the inversion position from the origin position. As a result, the hand posture is changed from the unused posture to the used posture, and preparation for receiving the used plate PP is completed. Then, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the X direction. Thereby, the plate shuttle 23L is moved to the plate suction position XP23 and positioned.

On the other hand, while the first stage elevating motor M31 rotates the rotating shaft to attract and hold the plate PP, the attracting plate 34 is lowered toward the hands 232 and 232 of the plate shuttle 23L, The valves V31 and V32 are closed so that the adsorption of the plate PP by the adsorption mechanism of the adsorption plate 34 is released so that the plates PP) is completed. Then, the first stage lifting motor M31 reversely rotates the rotation shaft, and lifts the attracting plate 34 to the initial position. Thereafter, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the (+ X) direction. Thereby, the plate shuttle 23L is moved to the intermediate position XP22 while being held the used plate PP, and is positioned.

At next step S8, the shuttle horizontal drive motor M21 rotates the rotary shaft to move the shuttle holding plate 22 in the (+ X) direction. Thereby, the substrate shuttle 23R holding the substrate SB before the process is moved to the substrate suction position XP23 and positioned. The pre-alignment process of the substrate SB and the adsorption process of the substrate SB are carried out in the same manner as the pre-alignment process of the plate PP and the adsorption process of the plate PP by the adsorption plate 34. [ Thereafter, when the adsorption of the substrate SB is detected, the stage lifting motor M31 rotates the rotation axis to raise the adsorption plate 34 vertically upward while holding the substrate SB, and the substrate adsorption position XP23 ) Of the substrate SB. And the board | substrate shuttle lifting motor M22R rotates a rotating shaft, and moves the board | substrate shuttle 23R from a prealignment position to a conveyance position, and positions it. Thereafter, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the (-X) direction, and positions the vacated substrate shuttle 23R at the intermediate position XP24.

In the next step S9, the thickness of the blanket is measured, and after the precise alignment is further carried out, the transferring process is carried out. That is, the thickness of the blanket BL is measured in the same manner as in the thickness measurement in the patterning process. The main reason for measuring the thickness of the blanket (BL) not only immediately before the patterning but also just before the transfer is that the thickness of the blanket (BL) changes with the passage of time due to swelling of a part of the blanket (BL) It is possible to perform high-precision transfer processing by measuring the thickness of the blanket.

Next, the first stage elevating motor M31 rotates the rotating shaft in a predetermined direction to lower the attracting plate 34 in the downward direction (-Z) to move the substrate SB in the vicinity of the blanket BL. The second stage lifting motor M32 rotates the rotating shaft to move the attracting plate 34 up and down at a narrow pitch so that the gap between the substrate SB and the blankets BL in the vertical direction Z, Adjust. This gap amount is determined by the control unit 6 based on the results of the thickness measurement of the substrate SB and the blanket BL. Then, the periphery of the blanket BL is pressed by the pressing member 71, similarly to the patterning (step S5).

In this way, both the substrate SB and the blanket BL are pre-aligned and are spaced apart by appropriate intervals in the transfer process. However, in order to accurately transfer the pattern layer formed on the blanket BL to the substrate SB , It is necessary to precisely align both sides. Therefore, in the present embodiment, the image pickup section 43 picks up an alignment mark patterned on the blanket BL and an alignment mark formed on the substrate SB, and outputs the image to the image processing section 65 of the control section 6 do. Based on the image, the control unit 6 obtains the control amount for positioning the blanket BL with respect to the substrate SB, and also creates an operation command for the stage driving tool M41 of the alignment unit 4. [ The stage driving motor M41 operates in accordance with the control command to move the adsorption plate 51 in the horizontal direction and rotate around the imaginary rotational axis extending in the vertical direction Z to move the blanket BL to the substrate SB ) (Alignment process).

Then, the valves V51 and V52 operate to partly supply air between the adsorption plate 51 and the blanket BL to partially blow the blanket BL. This floating portion is pressed onto the substrate SB held on the upper stage portion 3. [ As a result, the blanket BL is in close contact with the substrate SB. Thereby, the pattern layer on the side of the blanket BL is precisely aligned with the pattern of the lower surface of the substrate SB, and is transferred to the substrate SB.

In the next step S10, the substrate SB is peeled off from the blanket BL, the substrate SB is positioned on the neutral position, and the blanket (BL ), And discharging the same. Thereafter, the first stage elevation motor M31 rotates the rotation shaft, and the suction plate 34 is raised to the initial position (position higher than the conveyance position) while holding the substrate SB by suction.

In the next step S11, the shuttle horizontal drive motor M21 rotates the rotating shaft to move the shuttle holding plate 22 in the (+ X) direction. Thereby, the substrate shuttle 23R moves to the substrate suction position XP23 and is positioned. On the other hand, the first stage elevating motor M31 rotates the rotation shaft to lower the attraction plate 34 toward the hands 232 and 232 of the shuttle 23R for the substrate while holding the substrate SB by suction. Thereafter, the valve V31 is closed, whereby the suction of the substrate SB by the suction mechanism is released. Then, the first stage lifting motor M31 reversely rotates the rotation shaft, and lifts the attracting plate 34 to the initial position. Thereafter, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the -X direction so that the substrate shuttle 23R is held at the intermediate position ( XP24).

In the next step S12, the valves V51 and V52 operate to release the adsorption of the blanket BL by the adsorption plate 51. Then, the pin lifting cylinder CL51 is operated to lift the lift plate 541 to lift the used blanket BL up vertically from the attracting plate 51. Then, as shown in Fig. The blanket carrying robot accesses the apparatus 100 to receive the used blanket BL from the top of the lift pin 542 and retract it from the apparatus 100. Subsequently, the pin lifting cylinder CL51 is operated to lower the lift plate 541 so that the lift pin 542 descends in the downward direction (-Z) with respect to the attracting plate 51.

In the next step S13, the shuttle horizontal drive motor M21 rotates the rotating shaft, and the shuttle holding plate 22 moves in the (+ X) direction. Thereby, the plate shuttle 23L is moved to the plate transfer receiving position XP21 and positioned. Subsequently, the plate conveying robot of the plate cleaning apparatus takes out the used plate PP from the printing apparatus 100. Then, When the release of the plate PP is completed in this manner, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the (-X) direction so that the plate shuttle 23L is moved to the intermediate position XP22).

In the next step S14, the shuttle horizontal drive motor M21 rotates the rotating shaft to move the shuttle holding plate 22 in the -X direction. As a result, the substrate shuttle 23R moves to the substrate transfer position XP25 and is positioned. Subsequently, the substrate SB subjected to the transfer processing by the substrate transport robot of the substrate cleaning apparatus is taken out from the printing apparatus 100. When the removal of the substrate SB is completed in this way, the shuttle horizontal drive motor M21 rotates the rotation shaft to move the shuttle holding plate 22 in the (+ X) direction, thereby moving the substrate shuttle 23R to the intermediate position XP23). Thereby, the printing apparatus 100 returns to the initial state.

Next, the precise alignment operation in the printing apparatus 100 configured as described above will be described in more detail. The blanket BL held on the upper surface of the lower stage portion 5 and the substrate SB held on the lower surfaces of the upper stage portion 3 are precisely aligned. This precision alignment is performed by imaging the previously formed alignment marks of the blanket BL and the substrate SB with the imaging section 43 and operating the alignment stage 42 based on the imaging results . Here, the plane size of the assumed substrate SB is about 350 mm x 300 mm. On the other hand, the alignment accuracy between the target substrate SB and the blanket BL in the horizontal direction is, for example, about 3 m.

5 is a view showing a detailed structure of an alignment stage. As described above, the alignment stage 42 includes a stage base 421 and a stage tower 422. A support mechanism 423 is provided between the stage base 421 and the stage tower 422, The movement of the stage tower 422 relative to the stage base 421 is realized. In Fig. 5, the supporting mechanisms 423 provided at four corners of the stage base 421 are distinguished by reference numerals 423a, 423b, 423c and 423d, respectively. M41a, M41b, M41c, and M41d are assigned to the stage drive motor M41 coupled to each of them.

As the stage driving motor M41a drives the supporting mechanism 423a, the supporting mechanism 423a is movable in the Y direction within a predetermined range, as indicated by the dotted arrow in the vicinity of the supporting mechanism 423a. The stage drive motor M41b is driven by the support mechanism 423b in the X direction, the stage drive motor M41c supports the support mechanism 423c in the Y direction, And the support portion M41d can move the support mechanism 423d in the X direction in a predetermined range.

The stage 422 moves in the (+ Y) direction or the (-Y) direction with respect to the stage base 421 by moving the support mechanism 423a and the support mechanism 423c in the same direction. The stage 422 moves in the (+ X) direction or the (-X) direction with respect to the stage base 421 by moving the support mechanism 423b and the support mechanism 423d in the same direction. On the other hand, as they move in mutually opposite directions, the stage tower 422 rotates about the vertical axis with respect to the stage base 421. In this way, movement of the stage top 422 in the horizontal plane (XY plane) with respect to the stage base 421 and rotational movement about the Z axis are realized.

6 is a diagram showing the detailed structure of the imaging unit. As shown in Fig. 2, the upper end portion of the imaging section 43 extends to just under the suction plate 51 of the lower stage section 5, and a CCD camera 430 shown in Fig. 6 Respectively. The image pickup section 43 is provided at four positions corresponding to the four corners of the blanket BL to be attracted and held by the attracting plate 51. However, the structure of the image pickup section 43 is the same.

A transparent quartz window 52a is sandwiched between the adsorption plates 51 at positions corresponding to the four corners of the blanket BL so that the blanket from the lower side of the adsorption plate 51 through the quartz window 52a BL) to be seen through. A CCD camera 430 is disposed below the quartz window 52a. Concretely, the objective lens 435, the half mirror 437 and the light receiving surface 438 of the CCD imaging element are arranged in this order immediately below the quartz window 52a. The optical axis of the objective lens 435 coincides with the substantially vertical direction, and a quartz window 52a and a light receiving surface 438 are disposed on the optical axis. The light from the light source 436 is incident on the half mirror 437 from the side and the light is reflected by the half mirror 437 and emitted toward the quartz window 52a to be transmitted through the quartz window 52a to the blanket BL.

A predetermined first alignment mark AM1 is previously formed at a position facing the quartz window 52a in the lower surface of the substrate SB held on the lower surface of the attracting plate 34 of the upper stage portion 3. [ On the other hand, a predetermined second alignment mark AM2 is previously formed at a position facing the quartz window 52a in the surface of the blanket BL held on the surface of the attracting plate 51 of the lower stage portion 5 have. That is, the substrate SB and the blanket BL are opposed to each other so that the respective alignment mark forming surfaces face each other. As a result, the distance between the two alignment marks in the vertical direction (Z direction) can be reduced. It is preferable that the gap Gsb between the substrate SB and the blankets BL after the gap adjustment is made as small as possible. However, considering the dimensional accuracy of each part of the device, the warpage of the substrate SB and the blanket BL, it is necessary to separate the substrate SB and the blanket BL in order to prevent unintended contact with each other. Here, for example, the interval Gsb is set to 300 mu m.

The blanket (BL) has a thin elastic layer made of, for example, silicone rubber on the surface of a glass plate or a transparent resin plate, and has light transmittance. The first alignment mark AM1 and the second alignment mark AM2 can be concurrently viewed through the quartz window 52a and the blanket BL from the lower side of the lower stage portion 5 have. The CCD light receiving surface 438 captures the first alignment mark AM1 and the second alignment mark AM2 arranged facing the quartz window 52a collectively in the same field of view.

The objective lens 435, the half mirror 437, the light receiving surface 438 and the light source 436 are integrally held by the XY table 431 in the direction along the XY plane and by the precision elevation table 432 And is movable in the vertical direction (Z direction). The front focal point of the objective lens 435 is aligned with the alignment mark formation surface of the blanket BL by the precision lift table 432. [ On the other hand, the rear focal point is aligned with the light-receiving surface 438 of the CCD imaging element in advance. Therefore, an optical image focused on the second alignment mark AM2 formed on the blanket BL forms an image on the CCD light receiving surface 438, and the optical image is picked up by the CCD camera 430. [

The second alignment mark AM2 is formed on the surface of the elastic layer of the blanket BL simultaneously with the formation of the pattern by the same material as the pattern to be transferred onto the substrate. That is, the plate PP is provided with a pattern corresponding to the alignment mark AM2 in advance with the pattern to be transferred to the substrate SB. The plate PP is brought into close contact with the coating layer on the blanket BL to perform patterning The alignment mark AM2 is also formed at the same time. As described above, one main surface of the main surface of the blanket BL on the side where the elastic layer is formed serves as a surface for forming the pattern and the alignment mark.

7A to 7C are views showing examples of patterns of alignment marks. More specifically, Fig. 7A shows the first alignment mark formed on the substrate in this embodiment, and Fig. 7B shows the second alignment mark formed in the blanket in this embodiment.

As shown in Fig. 7A, the first alignment mark AM1 formed on the substrate SB is composed of a plurality of (four in this example) first alignment patterns AP1 (AP11 to AP14) spaced from each other . Each of the alignment patterns AP1 has a size such that the figure does not disappear even when the focus is not matched. For example, in a square (one square in this example) having one side of about 50 mu m, Is a figure of solid medium which is painted in the same way. These first alignment patterns AP1 are arranged at four positions, each of which is a vertex of the square, to constitute the first alignment mark AM1. The interval between the alignment patterns AP1 is 750 mu m.

On the other hand, as shown in Fig. 7B, the second alignment mark AM2 formed on the blanket BL comprises a single second alignment pattern AP2. The second alignment pattern AP2 is, for example, an annular hollow shape having a square with a side of about 120 탆 and hollowed out from the inside. The line width of each side forming the square is, for example, 10 占 퐉, and therefore, one side of the inner square is about 100 占 퐉.

Fig. 7C shows the spatial frequency spectrum of these alignment patterns. When the spatial frequency components of these patterns are compared, the first alignment pattern AP1, which is a solid shape, contains a lower frequency component than the second alignment pattern AP2, which is a hollow shape. That is, the spectrum of the spatial frequency is shifted toward the low-frequency side in the first alignment pattern AP1. In the precise alignment operation to be described later, the position of each alignment pattern is detected using this feature.

8 is a view showing the arrangement of alignment marks for precise alignment operation. The substrate SB and the blanket BL are plate-like bodies having substantially the same planar size, and when both are overlapped, alignment marks are formed at positions corresponding to each other. That is, a predetermined pattern such as a circuit pattern is formed at the center of the plate-like substrate SB to set an effective pattern area PR that finally functions as a device. The surface area of the corresponding blanket BL is the effective pattern area PR of the blanket BL and the pattern to be transferred to the substrate SB is patterned into this area PR by the plate PP. In the example shown in Fig. 8, the square region at the center of the rectangular substrate SB is referred to as the effective pattern region PR, but these shapes are not limited to rectangular shapes, and may be arbitrary.

An area outside the four corners of the effective pattern area PR and close to each part of the substrate SB is an alignment mark forming area AR. The quartz windows 52a provided on the attracting plate 51 of the lower stage portion 5 are respectively provided at positions corresponding to the four alignment mark formation areas AR described above.

In the substrate SB, a first alignment mark AM1 is previously formed in each of four alignment mark formation areas AR by, for example, a photolithography technique. On the other hand, the second alignment mark AM2 formed on each alignment mark formation area AR of the blanket BL is formed with a pattern formed on the effective pattern area PR, . The pattern formed in the effective pattern area PR on the blanket BL and the alignment formed in the alignment mark forming area AR can be obtained without regard to the positional relationship between the plate PP and the blanket BL at the time of patterning, The positional relationship with the mark is invariant. Thereby, the positional relationship between the substrate SB and the pattern on the blanket BL is kept constant by alignment using the alignment mark. Therefore, precision alignment between the plate PP and the blanket BL is not necessarily required.

In the present embodiment, the imaging section 43 of the alignment section 4 picks up the alignment pattern configured as described above. An alignment pattern is detected from the sensed image to grasp the positional relationship between the substrate SB and the blankets BL (strictly, a pattern on the blanket BL), and an adjustment operation is performed to adjust such positions as necessary.

Each of the first alignment mark and the second alignment mark in the present embodiment includes one or a plurality of these alignment patterns as constituent elements. However, the precision alignment operation itself of the present embodiment is also achieved by an alignment mark composed of only a single alignment pattern. Therefore, here, a first alignment mark consisting of a single first alignment pattern AP1 is formed on the substrate SB, and a second alignment mark composed of a single second alignment pattern AP2 is formed on the blanket BL The principle of the alignment operation will be explained using the formed example.

9A to 9C are views showing an example of an image taken by a CCD camera. As shown in Fig. 9A, the captured image IM includes a second alignment pattern AP2 captured with a high image contrast in a state in which the focus is imaged. Therefore, it is relatively easy to detect the center position G2m of the second alignment pattern AP2 from the captured image. When the second alignment pattern AP2 is an annular rectangular hollow shape, the center position can be obtained, for example, as follows. 9B, the edge portion of the second alignment pattern AP2 is extracted by binarizing the brightness for each position in the image to the minimum limit value causing a predetermined reaction, From this, the outline of the second alignment pattern AP2 can be estimated and the position of the center G2m thereof can be obtained. Particularly, since the features such as the external dimensions and the line width of the pattern are known in advance, the image processing unit 65 can apply specialized image processing to the features.

On the other hand, the first alignment pattern AP1 formed on the substrate side is not always focused. The distance between the first alignment pattern AP1 and the second alignment pattern AP2 in the direction of the optical axis is equal to or smaller than the depth of field of the objective lens 435, It is possible to capture an image in which the both are in focus. However, when the interval between the alignment patterns is larger than the depth of field of the objective lens 435, in order to focus on the second alignment pattern AP2, the first alignment pattern AP1 is out of the depth of field and is not focused, Is picked up as a blurred image.

In this embodiment, an objective lens 435 having a magnification of about five times is used, and its depth of field is about 占 30 占 (about 60 占 퐉 as a focusing range). On the other hand, the gap Gsb between the substrate SB set in the apparatus 100 and the blanket BL is about 300 mu m after the gap adjustment. Under these conditions, it is impossible to simultaneously focus on both alignment patterns. That is, in order to focus on the second alignment pattern AP2, the first alignment pattern AP1 is inevitably out of focus. The precision alignment method according to the present embodiment enables highly accurate alignment even in this case.

When the first alignment pattern AP1 is not in focus, the first alignment pattern AP1 is picked up in a state in which the first alignment pattern AP1 is larger than the original outline shown by the broken line and the contour is blurred, as shown in Fig. 9A. Therefore, relatively high frequency components among the spatial frequency components of the original shape of the first alignment pattern AP1 are lost. Therefore, it can be considered that the method of extracting an edge as in the case of the second alignment pattern AP2 is difficult to apply and the detection error also becomes large. Therefore, as shown in Fig. 9C, the center position of the first alignment pattern AP1 is obtained at the peak position of the brightness level.

At this time, as shown in Fig. 7C, by making the shape of the first alignment pattern AP1 include a lot of low spatial frequency components, the loss of the image information is suppressed and the decrease in the detection accuracy of the center position . Particularly, when image processing accompanied by shading correction is performed, a low frequency component is also lost thereby, and therefore, it is effective to use a pattern of a shape in which the distribution of spatial frequencies is gathered on the low-frequency side.

Further, since it is known in advance that the high-frequency component contained in the original shape disappears, the high-frequency component does not have usefulness for detection of the center position, and rather acts as noise. Therefore, it is preferable to perform a low-pass filtering process for removing a high-frequency component from the image, and to detect the center position from the image after the removal. In this manner, the position of the center G1m of the first alignment pattern AP1 that is not in focus is detected.

When the positional relationship between the substrate SB and the blanket BL is proper when the center position Glm of the first alignment pattern AP1 is taken as a reference as shown in Fig. 9A, for example, 2 The center position at which the alignment pattern AP2 should be located is indicated by the symbol G2t. However, the position of the actually measured center G2m does not always coincide with this, and a precise alignment operation is required to match them. Namely, in the precision alignment operation, as shown by the arrow in Fig. 9A, the substrate SB and the blanket BL are arranged so as to match the center position G2m of the detected second alignment pattern AP2 to the proper position G2t, And adjusts the relative position of In this embodiment, the required amount of movement of the stage column 422 of the alignment stage 42 is calculated based on the imaging result, and the required movement amount of the stage stage 422 of the alignment stage 42 is calculated. Thus, the lower stage portion 5 supported by the stage column 422, The blanket (BL) is moved to perform alignment with respect to the substrate (SB).

10 is a flowchart showing the flow of processing of the precision alignment operation. This process is also performed as part of the process of step S9 in Fig. First, the precision elevating table 432 causes the CCD camera 430 provided in the image pickup unit 43 to be aligned with the alignment mark formation surface (upper surface) of the blanket BL (step S901). Further, since the thickness of the blanket (BL) varies due to the swelling, it is necessary that the fitting be performed every time the transferring process is performed.

More specifically, the auto focusing (AF) adjusting operation described below can perform the focusing. That is, the CCD camera 430 is operated in the vertical direction (Z direction) by the precision elevation table 432 to change the focus position to a constant pitch in the Z direction, and the CCD camera 430 performs imaging every time . Then, the position at which the image contrast is maximized is calculated from the image of the alignment pattern AP2 to be imaged, and the focus position of the objective lens 435 is adjusted at that position. Also, the focussing of the four CCD cameras 430 is performed individually, but the processing contents are the same.

Fig. 11 is a flowchart showing the focus fitting operation. First, the height of the CCD camera 430, that is, the position in the Z direction, is set to a predetermined initial value by the precision elevation table 432 (step S911). The CCD camera 430 picks up the second alignment pattern AP2 every time the height of the CCD camera 430 is varied and set by the precision elevating table 432 (step S912). This is repeated until the CCD camera 430 reaches a predetermined final height (step S913). In the present embodiment, the CCD camera 430 is moved in a step of 20 占 퐉 in a range of ± 100 占 퐉 from a predetermined standard height, and imaging is performed at each position.

The reason why the second alignment pattern AP2 appears most clearly among the original images picked up at the respective heights is that the focus of the CCD camera 430 is matched with the second alignment pattern AP2 (Closest) state. Thus, by locating the image and setting the CCD camera 430 at a height corresponding thereto, the object of focusing is achieved.

However, since the second alignment pattern AP2 is formed of the same material as the pattern to be transferred onto the substrate SB, it can not always be said that imaging can be performed with a good contrast. For example, in the case where the second alignment pattern AP2 is formed of a material having optical characteristics (particularly, refractive index, reflectance, etc.) close to the blanket BL, only a low image contrast can be obtained even if the image pick- have.

Further, in a state in which the substrate SB and the blanket BL are arranged very close to each other, the illumination light from the light source 463 is reflected by the substrate SB, so that a relatively bright image can be obtained. On the other hand, when the distance between the substrate SB and the blanket BL is relatively large, for example, in a state in which the gap between the substrate SB and the blanket BL has not been adjusted, BL, the substrate SB located farther from the substrate is farther away, so that a sufficient amount of reflected light can not be obtained, resulting in a dark image with low contrast. The same applies to the case where the reflectance of the substrate SB itself is low.

In this way, it may not be expected to perform imaging of the second alignment pattern AP2 under a good environment in a state where the focus is not yet aligned, and it may be difficult to detect the second alignment pattern AP2 from the image . However, it is necessary to perform the pint alignment surely even under such an environment. In order to make this possible, the present embodiment is configured as follows.

In the CCD camera 430 of the present embodiment, the size of one pixel of the imaging device is about 0.7 mu m. On the other hand, as shown in Fig. 7B, the line width of the second alignment pattern AP2 is 10 mu m, which corresponds to about 14 pixels of the imaging element. Therefore, even with a low contrast image, it is possible to make the second alignment pattern AP2 more easily detectable from the image by emphasizing the spatial frequency component corresponding to 14 pixels corresponding to the line width. The shape and size of the second alignment pattern AP2 are already known, and in this case, the detection of the second alignment pattern AP2 from the captured image is sufficient if the edge position is specified.

For example, by removing spatial frequency components that are sufficiently smaller than the line width, for example, a half or less of the line width, information on the edges of the second alignment pattern AP2 is not lost, The random noise component can be removed. Further, by removing the spatial frequency component corresponding to a size which is sufficiently larger than the line width, for example, twice the line width, the information on the edge of the second alignment pattern AP2 is not lost, , It is possible to exclude the influence of, for example, shading.

Specifically, for the original image picked up at the respective heights, the image processing unit 65 performs a process for calculating the position of the original image corresponding to the predetermined pixel unit set on the basis of the pattern shape of the second alignment pattern AP2, Averaging compression is performed in half or less of the number of pixels (for example, 4 pixels x 4 pixels) (step S914). Here, the image data after the averaging and compression is referred to as first data. By carrying out averaging and compression in this way, the high frequency components included in the original image are removed, and the random noise component is effectively removed. That is, the averaging compression process substantially corresponds to the low-pass filtering process. There is also an effect of reducing the amount of data in subsequent calculations.

Next, averaging compression is performed on the first data after the averaging compression in units of a predetermined pixel, for example, 7 pixels x 7 pixels (step S915). Here, the term " pixel " means a pixel in the first data compressed in units of four pixels, and therefore, the seven pixels here correspond to 28 pixels (that is, twice the line width) in the original image. Thus, a low frequency component that does not correspond to the second alignment pattern AP2, for example, a variation due to shading is extracted. This is regarded as second data.

Subsequently, by taking the ratio between the first data and the second data, the influence of the shading from the first data is excluded. That is, the processing for obtaining this ratio substantially corresponds to the high-pass filtering processing for removing the fluctuation component at the low frequency. As a result, only the spatial frequency component of the band centered on the component corresponding to the line width of the second alignment pattern AP2 is extracted. That is, the spatial frequency component corresponding to the line width of the second alignment pattern AP2 is extracted by the band-pass filter. By multiplying the value of the thus obtained ratio by a predetermined emphasis coefficient K greater than 1, an image in which the contrast of the image element corresponding to the line width of the second alignment pattern AP2 in the original image is emphasized is obtained (step S916 ).

12 is a diagram showing an example of image data emphasized by contrast. This figure shows the relationship between the position and the pixel value on one line drawn in the image of the second alignment pattern AP2. The reference character A indicates image data of the original image, the data includes noise, and the original image can not provide sufficient contrast for locating the second alignment pattern AP2. Reference character (B) represents the first data. Although the high-frequency noise component is largely eliminated by the low-pass filter processing, a slight variation can be seen than that caused by the shading. The reference character C represents the second data, and only the variation of the low frequency due to the shading is shown.

The symbol (D) shows the data after contrast enhancement, and the contrast is emphasized after the low-frequency fluctuation due to the shading is removed, so that the peak at the position corresponding to the edge of the second alignment pattern AP2 can be clearly recognized. The clearer the second alignment pattern AP2 appearing in the image is, the more clearly this peak appears. By using this, the second alignment pattern AP2 can be detected from the image.

For example, in the image in which the second alignment pattern AP2 is not included at all, a remarkable peak does not appear in the data after the contrast enhancement (reference symbol D), and the pixel value of the entire image is the same value close to the average level Vavg . On the other hand, as the focus of the CCD camera 430 approaches the upper surface of the blanket BL, a pixel value with a large divergence from the average level Vavg appears. Therefore, the sum obtained by obtaining the absolute value of the difference between the pixel value Vi and the average value Vavg for each position in the image and integrating the value in the image,

Σ│Vi-Vavg│ ... (Equation 1)

The deviation amount between the focus position of the CCD camera 430 and the upper surface position of the blanket (BL) can be evaluated by the magnitude of the value of the blanket (BL). The closer the focus of the CCD camera 430 is to the upper surface of the blanket BL, the more spatial frequency components corresponding to the second alignment mark AM2 included in the image become, and accordingly, . Therefore, the value obtained by (Formula 1) for each of the images picked up with different heights of the CCD camera 430 is referred to as " AF evaluation value ". Among these images, the height of the CCD camera 430 when an image in which the spatial frequency component corresponding to the second alignment mark AM2 that maximizes the AF evaluation value is largest is captured by the focus of the CCD camera 430 May be a height that is closest to the upper surface of the blanket (BL).

The emphasis coefficient K can be an arbitrary value larger than 1. However, the larger the value, the stronger the contrast is, and the higher the peak corresponding to the edge of the second alignment pattern AP2 is. In this case, it is feared that the signals irrelevant to the alignment pattern may be emphasized. However, according to the experiment of the inventors and the like, at least the alignment of the alignment of the alignment does not affect the degree of alignment. By performing band-pass filter processing for extracting a band corresponding to a spatial frequency component characterizing the second alignment pattern AP2, which is specific to the shape of the alignment pattern to be detected, It is considered that the irrelevant signals are sufficiently reduced.

On the other hand, it is in principle impossible to emphasize the contrast beyond the dynamic range originally possessed by the CCD camera 430, and the upper limit of the appropriate value of the emphasis coefficient K is determined on this point. For example, in an imaging system in which the average amplitude of the random noise for the maximum output signal is N%, the appropriate maximum value Kmax of the emphasis coefficient K is given by the following expression:

Kmax = 100 / 4N ... (Equation 2)

Lt; / RTI > This is because, when the noise of the amplitude of ± N% is emphasized by (100 / 2N) times, it reaches 100% by only the noise component, and from the fact that it is difficult to separate the signal with the S / N ratio less than 2 from the noise .

For example, in the imaging system in which the ratio of the random noise to the signal is 1%, the upper limit of the emphasis coefficient K is 25.

Returning to Fig. 11, the AF evaluation values defined by (Formula 1) are calculated based on the above-described principle from the image data at each height of the contrast enhanced by the process up to Step S916 (Step S917). Then, the height of the CCD camera 430 is set to the height corresponding to the image having the maximum AF evaluation value among them (step S918). Thereby, the focus position of the CCD camera 430 is almost aligned with the upper surface of the blanket BL.

Returning to Fig. 10, the description of the precision alignment operation will be continued. The first alignment pattern AP1 and the second alignment pattern AP2 corresponding to the first alignment pattern AP1 are included in the field of view of each CCD camera 430 in the state where the focus adjustment is performed in this way, AP2) is in focus. Each of the CCDs 430 picks up the image and sends the image data to the image processing unit 65 (step S902). The image processing unit 65 performs predetermined image processing on the image thus captured and detects the positions of the first and second alignment patterns AP1 and AP2 in the image (steps S903 and S904). More specifically, their center positions (GIm, G2m) are detected.

When the center G1m of the first alignment pattern AP1 and the center G2m of the second alignment pattern AP2 are detected as described above, the positional deviation between them is calculated (step S905) . What should be calculated here is not the positional shift amount between the centers G1m and G2m of the detected two alignment patterns but the second alignment pattern AP2 derived from the center position Glm of the first alignment pattern AP1, Between the proper center position G2t of the first alignment pattern AP2 and the center position G2m of the second alignment pattern AP2 detected by actual measurement. When the first and second alignment patterns are disposed such that the center positions of the first and second alignment patterns are common (that is, G2t is set equal to Glm), the position between the centers G1m and G2m of the two alignment patterns The amount of displacement becomes an amount to be obtained.

The positional deviation between the substrate SB and the blanket BL in the XY plane is not only deviated in the X direction and the Y direction but also deviated in the twisted type, that is, the rotational angle around the vertical axis is different. It is difficult to correct the deviation in the rotation direction around the vertical axis (hereinafter, referred to as "? Direction ") in the adjustment of the center positions of the pair of alignment patterns provided on each of the substrate SB and the blanket BL. It is difficult to grasp the rotation angle of the pattern from the blurred image, especially when one of the alignment patterns is picked up in a state in which the focus does not fit.

In this embodiment, a pair of alignment marks are provided for each of the four corners of the substrate SB and the blanket BL (FIG. 8), and these are picked up by four sets of image pickup units 43. The moving amounts of the stage top 422 in the X, Y, and the θ directions are comprehensively adjusted so that the positional deviations in the X, Y, and θ directions obtained from each of the images captured by the four sets of the image pickup units 43 are averaged . By doing so, the substrate SB and the blanket BL can be precisely aligned.

The center position of the alignment pattern picked up by each camera is obtained by the image processing by the image processing section 65 with respect to each of the substrate SB side and the blanket BL side (steps S903 and S904). From this calculation result, the positional shift amount between the substrate SB and the blanket BL is calculated (step S905). The positional shift amount here is calculated for each of the X direction, Y direction and? Direction. When the positional shift amount thus obtained is within the predetermined allowable range (step S906), the positional deviation between the substrate SB and the blanket BL is neglected, and the precision alignment operation is terminated.

When the positional displacement exceeds the permissible range, it is necessary to move the blanket (BL) to correct this. Subsequently, an upper limit is set for the number of times of retry of movement for alignment in consideration of the possibility that alignment can not be performed due to a problem of any device. That is, when the number of retries reaches a preset number of times (step S907), a predetermined error stop process is executed (step S908), and the process is terminated. As a content of the error stop process, for example, a user may be notified of the content of an error indicating the completion of the process itself by displaying a predetermined error message, and then waiting for an instruction from the user in subsequent processes. The processing may be resumed according to an instruction from the user.

On the other hand, if the number of retries does not reach the predetermined number of retries (step S907), the amount of movement of the blanket BL necessary for alignment is calculated (step S909). The alignment stage 42 is operated based on the calculated movement amount (step S910), and the position of the blanket BL is moved together with the stage top 422. In this state, imaging and center position detection of each alignment pattern is again performed, and it is determined whether or not the blanket BL needs to be moved again (steps S902 to S906). This process is repeated until the number of retries reaches a predetermined number (step S907).

9A), the positional relationship between the first alignment pattern AP1 and the second alignment pattern AP2 in each of the images captured by the CCD cameras 430 is set to a predetermined relationship (for example, Or the positional shift amount from the relationship falls within the allowable range. In this manner, alignment of the substrate SB with the blanket BL (precise alignment) is completed.

After the alignment process is completed as described above, air is transferred between the adsorption plate 51 and the blanket BL, so that the central portion of the blanket BL floats up to be brought into close contact with the substrate SB, Is transferred to the substrate SB. At this time, the second alignment mark AM2 formed on the surface of the blanket BL with the same material as the pattern is also transferred to the substrate SB together with the pattern. The second alignment mark AM2 is located at a position substantially opposite to the first alignment mark AM1 on the substrate SB at the time of completion of the precise alignment so that the blanket BL comes into contact with the substrate SB as it is, The second alignment mark AM2 is transferred to the vicinity of the first alignment mark AM1.

The transfer of the pattern onto the substrate SB is repeated several times as necessary. Naturally, the above-described alignment process is necessary every time. Therefore, every time the pattern transfer is performed, the second alignment mark formed together with the pattern is transferred to the substrate SB. At this time, the transferred second alignment mark may be an obstacle to the alignment operation for subsequent transfer processing. Arrangement of alignment marks (Fig. 7) in this embodiment takes this problem into consideration.

13A and 13B are views for explaining the arrangement of the alignment marks. As shown in Fig. 13A, the alignment marks AM1 on the substrate SB are arranged with four first alignment patterns AP11 to AP14 so as to form a square apex, respectively. The second alignment mark AM21 transferred from the blanket BL to the substrate SB by the first transfer process is surrounded by these four first alignment patterns AP11 to AP14 and the respective first alignment patterns AP11 to AP14 (Alignment mark transfer region) TR having a predetermined interval from the transfer electrodes AP11 to AP14.

In the alignment process prior to the second transfer processing, imaging is performed with the blanket (BL) in focus as described above. At this time, as shown in FIG. 13B, the image of the second alignment mark AM22 supported on the blanket BL is clear at this time, but the first alignment patterns AP11 to AP12 on the surface of the substrate SB and First, it is unclear because the focus does not match the second alignment mark AM21 transferred to the surface of the substrate SB.

At this time, if the unclearly reflected second alignment mark AM21 is overlapped or extremely close to any one of the first alignment patterns AP11 to AP14 and the second alignment mark AM22, There is a possibility that the alignment accuracy of the alignment process is lowered as a result. In particular, if such a detection error is included in the processing step (step S906 in FIG. 10) for determining whether or not the precise alignment operation has converged, the alignment process is terminated while the positional deviation remains.

In order to avoid such a problem, in the present embodiment,

(1) The second alignment mark AM2 on the blanket BL is transferred to a position away from the first alignment mark on the substrate SB by a predetermined distance or more,

(2) The second alignment marks AM2 transferred from the blanket BL to the substrate SB by a plurality of pattern transfers are transferred at different positions and at a sufficient distance from each other,

(3) In order to improve the alignment accuracy, in each alignment process, the first alignment pattern AP1 on the substrate SB side and the second alignment mark AM2 on the blanket BL side are arranged as close as possible to each other The design of the alignment mark is carried out.

That is, the above requirement (1) is satisfied by limiting the transfer position of the second alignment mark AM2 within the alignment mark transfer area TR away from the first alignment patterns AP11 to AP14. Considering that the imaging of the state in which the focus does not match, the size of the appearance of the images of the first alignment patterns AP11 to AP14 and the transferred second alignment mark AM2 may be widened by about twice as much as actually. The position of the first alignment patterns AP11 to AP14 and the transfer position of the second alignment mark AM2 in each transfer are at least an outline dimension (50 μm) and a second alignment mark of the first alignment pattern AP1. It is necessary to space apart more than half (85 micrometers) of the sum of the external dimension (120 micrometers) of (AM2). In this embodiment, as shown in Fig. 13B, this distance is set to 115 mu m.

In order to satisfy the requirement (2), it is preferable that the position of the second alignment mark AM2 carried on the blanket BL is made different for each transfer and the amount of change in the position is sufficiently large. In order to satisfy the requirement (3), it is preferable that a plurality of first alignment patterns AP1 are arranged apart from each other and a second alignment mark AM2 to be newly transferred is arranged close to at least one of them good.

Taking these into consideration, in the present embodiment, the first alignment mark (AP11 to AP14) on which the four first alignment patterns AP11 to AP14 are arranged is formed so as to surround the alignment mark transfer area TR to which the second alignment mark AM2 is transferred AM1). A space for transferring up to nine second alignment marks AM2 is secured in the alignment mark transfer area TR. Therefore, pattern transfer is possible up to 9 times. The transfer pitch between the second alignment marks in the transfer area TR is set to 200 mu m so that the second alignment mark AM22 to be newly transferred is not superimposed on the image of the second alignment mark AM21 that has been transferred Respectively. The first alignment mark AM1 shown in Fig. 7A is configured in this way.

By doing so, at least one of the second alignment mark AM2 carried on the blanket BL and the first alignment pattern AP11 through AP14 formed on the substrate SB is transferred to the CCD camera 430, In the same field of view, and can perform alignment with high accuracy based on the image. At this time, it is prevented that the image of the second alignment mark transferred onto the substrate SB in the previous transfer process interferes with the second alignment mark AM2 on the surface of the blanket BL, , It is possible to maintain a high positional accuracy between the patterns transferred in each cycle.

As described above, in this embodiment, before transferring the pattern carried on the blanket (BL) to the substrate (SB), the formed alignment marks are taken, and the blanket (BL) and the substrate (SB) And performs alignment processing for performing alignment with respect to the substrate. At this time, the focus of the CCD camera 430 which captures an image is matched with the 2nd alignment mark AM2 of the blanket BL upper surface. The second alignment mark AM2 is a pattern mainly containing high spatial frequency components, while the first alignment mark AM1 provided on the substrate SB side is a pattern containing much lower spatial frequency components. Even if the focus does not match, the position detection can be performed with high accuracy.

In order to match the focus of the CCD camera 430 with the second alignment mark AM2 on the blanket BL, in the present embodiment, the second alignment mark AM2 included in the image is performed by performing contrast emphasis on the captured image. ) Is easily detected. More specifically, a filtering process for selectively extracting a band corresponding to the spatial frequency component of the second alignment mark AM2 is performed using the already known shape of the second alignment mark AM2, The image component corresponding to the edge of the second alignment mark AM2 is particularly emphasized by multiplying it by an enhancement coefficient K that is greater than one. In this way, it is possible to separate and detect the second alignment mark AM2 from a noise component or the like.

Therefore, even when the amount of reflected light from the second alignment mark AM2 is small, for example, because the second alignment mark AM2 does not have sufficient reflectivity to the light, the CCD camera to the second alignment mark AM2. The focusing of 430 can be performed with high precision.

By performing the alignment process in such a manner that the second alignment mark AM2 is aligned with the focus, in this embodiment, alignment between the substrate SB and the pattern carried on the blanket BL can be performed with high accuracy. have. In this state, since the substrate SB and the blanket BL come into contact with each other, it is possible to transfer the pattern to a predetermined position of the substrate SB with high accuracy.

As described above, in the present embodiment, the blanket BL corresponds to the "carrier" of the present invention, and the second alignment mark AM2 corresponds to the "alignment mark" of the present invention. On the other hand, the first alignment mark AM1 formed on the substrate SB corresponds to the "substrate side alignment mark" of the present invention.

Further, in the above embodiment, the upper stage portion 3 and the lower stage portion 5 function as a "holding means" of the present invention as one body. Moreover, the imaging part 43 functions as the "imaging means" of this invention, and the precision lifting table 432 functions as the "focus adjustment mechanism" of this invention. Further, the image processing section 65 functions as the "image processing means" of the present invention, while the alignment section 4, particularly the alignment stage 42, functions as the "alignment means" of the present invention.

The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the invention. For example, the shape of the alignment mark shown in the above-described embodiment is merely an example, and various other shapes can be employed. However, since imaging is assumed in a state where the focus is not correct as described above, it is preferable that the spatial frequency component of the alignment mark image is characteristic so that the detection is easy even in such a state.

In other words, with respect to the first alignment mark AM1 formed on the substrate SB, the first alignment mark AM1 includes a relatively large number of relatively low frequency components so as to be able to accurately detect the center position thereof even in a state where the alignment is not performed, It is preferable that the figure be point-symmetric with respect to the number of rotation angles. It is to be noted that the second alignment mark AM2 formed on the blanket BL has a characteristic portion that includes a large number of relatively high frequency components and can be extracted by narrowband band pass filter processing, Which is preferable in enhancing tolerance.

In the above embodiment, the image data (first data) from which the random noise component is removed by the low-pass filter is removed from the data by removing the higher-frequency component from the data (second data) Pass filter may be realized by a combination with a high-pass filter that removes a low-pass component from the first data. In an imaging system in which noise such as shading or the like is not a problem of low frequency components, removal of low frequency components may be omitted.

In the above embodiment, the entire CCD camera 430 is pinched by raising and lowering it with a precision elevating table 432. However, instead of this, an image-forming optical system composed of a plurality of lenses may be provided, It is also possible to perform the pin alignment.

In the above embodiment, four sets of alignment marks are formed in the vicinity of the four corners of the substrate SB and the blanket BL, but the number of alignment marks is not limited to this and is arbitrary. However, in order to appropriately correct the positional deviation around the vertical axis, it is preferable to use a plurality of sets of alignment marks formed at different positions, and it is more preferable that they are located as far apart as possible. Further, in order to suppress the error caused by the positional deviation of each camera, it is preferable that three or more sets of alignment marks are provided.

In the above embodiment, the alignment mark on the blanket BL is formed of the same material as the pattern forming material. However, this is not an essential requirement. For example, an alignment mark not transferred to the substrate is transferred to the blanket BL in advance . In this case, in order to carry out pattern transfer to the substrate SB with high positional accuracy, the positional accuracy of the pattern carried on the blanket BL becomes important, so that the blanket BL is patterned by the plate PP It is necessary to more precisely align the plate PP with the blanket BL.

In the above embodiment, the alignment mark transfer area TR on the substrate SB side is a blank area in which nothing is provided. However, in order to postpone the positioning of the second alignment mark AM2 transferred thereto, for example, a marker small enough not to affect the alignment process may be used as the second alignment mark AM2 to be transferred, It may be provided in advance in correspondence with each of these.

Although the alignment mark transfer area TR capable of transferring a maximum of nine second alignment marks AM2 is provided on the substrate SB in the above embodiment, the second alignment marks AM2 , That is, the number of times of pattern transfer to the substrate SB is arbitrary. For example, even when pattern transfer to the substrate SB is performed only once, the above-described focusing operation effectively functions.

In the above embodiment, the blanket (BL) is patterned inside the printing apparatus which is an embodiment of the transfer apparatus of the present invention. However, the present invention is not limited to this. For example, the present invention can be suitably applied to an apparatus for carrying out pattern transfer onto a substrate by carrying a blanket subjected to external patterning.

[Industrial Availability]

The present invention can be suitably applied to a technical field required to perform alignment of a carrier carrying a pattern and a substrate to be transferred thereon with high precision.

3: upper stage part (holding means)
4: alignment part
5: Lower stage part (holding means)
42: alignment stage (alignment means)
43: an image pickup section (image pickup means)
65: Image processing section (image processing section)
100: Printing apparatus (transfer apparatus)
430: CCD camera
432 precision lifting table (focus adjustment mechanism)
AM1: first alignment mark (substrate side alignment mark)
AM2: Second alignment mark (alignment mark)
BL: Blanket (Carrier)
SB: Substrate

Claims (11)

A transfer device for transferring a pattern or thin film as a transfer object onto a substrate,
A carrier for holding the transferred object and a predetermined alignment mark to be transferred to the substrate on one surface thereof and a holding member for holding the substrate in a state of being separated from each other and also having the one surface of the carrier held opposite to the substrate Sudan,
An image pickup means for picking up the alignment mark through the carrier from a surface side opposite to the one surface of the carrier,
Image processing means for detecting the alignment mark by image processing from an image picked up by the image pickup means,
And alignment means for adjusting a relative position between the substrate and the carrier based on the detected alignment mark,
The imaging means has a focus adjusting mechanism for focusing the alignment mark, and the focus adjusting mechanism performs focusing based on the image of the alignment mark subjected to contrast enhancement processing by the image processing means. Transfer device. The method of claim 1,
And said contrast enhancement process performed by said image processing means for the image of said alignment mark includes a filter process for extracting a spatial frequency component corresponding to the shape of said alignment mark. 3. The method of claim 2,
Wherein said image processing means emphasizes contrast by multiplying image data of said alignment mark after said filter processing by a coefficient larger than 1. 4. The method according to any one of claims 1 to 3,
The focus adjustment mechanism changes and sets the focus position of the imaging means in multiple stages, the imaging means performs imaging of the alignment mark each time, the image processing means performs the contrast enhancement processing on the imaging result,
And the focus position of the imaging means is adjusted at a position corresponding to the focus adjustment mechanism including the most spatial frequency component corresponding to the shape of the alignment mark among the contrast-enhanced images. 4. The method according to any one of claims 1 to 3,
Wherein the holding means holds the carrier and the substrate close to each other,
The image pickup means picks up the alignment mark carried on the carrier and the substrate side alignment mark formed on the substrate with the focus of the focusing mechanism aligned with the alignment mark;
The image processing means detects the relative position between the alignment mark on the carrier and the substrate side alignment mark and the alignment means adjusts the relative position between the substrate and the carrier on the basis of the result Characterized in that A transfer method for transferring a pattern or thin film as a transfer object onto a substrate,
A disposing step of disposing the carrier on the one surface of the carrier and the substrate facing each other with the one surface of the carrier facing away from the substrate;
The image pickup means arranged on the surface side opposite to the one surface of the supporting member picks up the alignment mark carried on the one surface of the supporting member through the supporting member, and the imaging based on the imaging result. A focusing step of fitting the focus of the means to the alignment mark,
Alignment of the said alignment mark and the board | substrate side alignment mark formed in the said board | substrate in the state which matched the focus of the said imaging means with the said alignment mark, and the alignment which adjusts the relative position of the said board | substrate and the said support body based on the imaging result. Fair,
And a transferring step of transferring the transferred object from the carrier to the substrate by bringing the substrate and the carrier having their relative positions adjusted into close contact with each other,
In the focusing step, a contrast enhancement process is performed on an image obtained by photographing the alignment mark, and the alignment mark is detected from the image after the processing. The method according to claim 6,
In the focusing step, the contrast enhancement process is performed including a process of emphasizing a spatial frequency component corresponding to the shape of the alignment mark. The method according to claim 6,
In the focusing step, the contrast enhancement process is performed including a filter process for extracting a spatial frequency component corresponding to the shape of the alignment mark. 9. The method of claim 8,
In the focusing step, a transfer method characterized by emphasizing contrast by multiplying the image data of the alignment mark after the filter process by a coefficient greater than one. 10. The method according to any one of claims 6 to 9,
In the focusing step, a space corresponding to the shape of the alignment mark is shown in the image in which the alignment mark is imaged every time while changing and setting the focus position of the imaging means in multiple stages, and the contrast emphasis process is performed on the imaging result. And the focus position of the image pickup means is adjusted to a position corresponding to the largest frequency component. 10. The method according to any one of claims 6 to 9,
Wherein the alignment mark is formed on the main surface of the carrier with the same material as that of the transfer object before the arrangement step.

Images