JP2015026738A - Positioning device, positioning method and drawing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide positioning art which can reduce time required for alignment of a substrate; and provide a drawing device using the positioning art.SOLUTION: Positioning art comprises: a process of transferring a stage 1 which holds a substrate W with a first alignment mark AM1 being imaged so as to position a second alignment mark AM2 formed on a surface of the substrate W in an imaging region R; a process of imaging the second alignment mark AM2; a process of detecting positional information of the first alignment mark AM1 from an image of the first alignment mark AM1 and detecting positional information of the second alignment mark AM2 from an image of the second alignment mark AM2 imaged by an imaging part; and a process of adjusting an orientation and position of the substrate W by transferring the stage 1 based on the positional information of the first alignment mark AM1 and second alignment mark AM2.

Description

  The present invention is applicable to various substrates such as semiconductor substrates, printed substrates, color filter substrates, flat panel display glass substrates, optical disk substrates, solar cell panels (hereinafter simply referred to as “panels for solar cells”). The present invention relates to a positioning technique for aligning a rotational position of a substrate (referred to as “substrate”) to a target position and a drawing apparatus equipped with the positioning technique.

  There are various types of substrate processing apparatuses that perform various processes on a substrate. As one of them, a drawing apparatus that draws a pattern by irradiating a surface of a substrate with a light beam is known (for example, Patent Document 1). reference). In this drawing apparatus, a process for aligning a pattern to be drawn on a substrate with a local region of the substrate, that is, a so-called alignment process and a printing process (so-called exposure process) are performed. For example, in the apparatus described in Patent Document 1, a large number of alignment marks on a substrate are sequentially moved to a position directly below the camera, and each time the movement is performed, the mark is captured by the camera, and mark position information is obtained from the mark image. Seeking. And the direction and position of a board | substrate are correct | amended based on those many positional information.

JP 2012-204422 A

  By the way, in a drawing apparatus using a positioning technique using an alignment mark, there is a demand for increasing the number of substrates that can be processed in a unit time by shortening the tact time. In order to satisfy the request, it is important to shorten the alignment processing time. However, in the prior art, a large number of, for example, four alignment marks are used, and they are sequentially moved to a position directly below the camera, and there is room for improvement in performing the alignment process in a short time.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a positioning technique capable of reducing the time required for substrate alignment and a drawing apparatus using the positioning technique.

  A positioning apparatus according to the present invention includes a stage that holds a substrate on which a first alignment mark and a second alignment mark are formed, a stage moving unit that moves the stage, and a surface of the substrate that is held on the stage. The first alignment mark image is picked up when the first alignment mark is located in the image pick-up area, and the second alignment mark image is picked up when the second alignment mark is located in the image pick-up area. An image pickup unit that picks up an image, a position information detection unit that detects position information of the first alignment mark from the image of the first alignment mark, and detects position information of the second alignment mark from the image of the second alignment mark; Pre-aligning one of the alignment mark and the second alignment mark And the other is used as a post-shoot alignment mark, and after the pre-shoot alignment mark is imaged by the image pickup unit, the stage is moved so that the post-shoot alignment mark is positioned in the image pickup region, and the first alignment mark and the second alignment mark And a position adjusting unit that adjusts the direction and position of the substrate by moving the stage based on the position information.

  In the positioning method according to the present invention, one of the first alignment mark and the second alignment mark formed on the surface of the substrate held on the stage is used as a pre-shooting alignment mark, and the other is used as a post-shooting alignment mark. The pre-shoot alignment mark is positioned in the image pickup area, and the stage for holding the substrate on which the pre-shoot alignment mark is imaged is positioned in the image pickup area. As described above, the step of moving, the step of imaging the post-shoot alignment mark, the position information of the first alignment mark from the image of the first alignment mark, and the position information of the second alignment mark from the image of the second alignment mark And a first alignment marker And a step of adjusting the direction and position of the substrate by moving the stage based on the position information of the first alignment mark and the second alignment mark.

  A drawing apparatus according to the present invention includes the positioning device, an optical head for drawing a pattern described by design data by irradiating light on a surface of a substrate held on a stage, a first alignment mark, and a second alignment mark. And a drawing control unit that controls drawing of the pattern on the substrate based on the corrected design data obtained by correcting the design data based on the position information of the alignment mark.

  In the present invention configured as described above, one of the first alignment mark and the second alignment mark is a pre-shooting alignment mark and the other is a post-shooting alignment mark. Then, after imaging the pre-shooting alignment mark by the imaging unit, the stage holding the substrate is moved so that the post-shooting alignment mark is positioned in the imaging area of the imaging unit, and imaging of the post-shooting alignment mark by the imaging unit is executed. . Then, the stage is moved based on the position information of the first alignment mark and the second alignment mark, and the direction and position of the substrate are adjusted. In this way, the number of times the substrate is moved to acquire position information can be minimized, and the time required for the direction and position of the substrate is shortened.

  As described above, according to the present invention, it is possible to minimize the number of times of moving the substrate for imaging of alignment and reduce the time required for alignment of the substrate. Further, by using such a positioning technique for a drawing apparatus, the productivity of the drawing apparatus can be increased.

It is a front view which shows 1st Embodiment of the drawing apparatus concerning this invention. It is a top view of the drawing apparatus of FIG. It is a block diagram which shows the electrical structure of the drawing apparatus of FIG. It is a figure which shows an example of the board | substrate by which a pattern is drawn with a drawing apparatus. 3 is a flowchart showing an operation of the drawing apparatus of FIG. 1. It is a flowchart which shows the operation | movement which acquires the positional information on the board | substrate loaded in the process stage. It is a figure which shows typically the acquisition operation | movement of a positional information. It is a figure which shows typically the operation | movement which adjusts the direction and position of a board | substrate, and positions a board | substrate. It is a flowchart which shows operation | movement of 2nd Embodiment of the drawing apparatus concerning this invention. It is a figure which shows typically the preliminary | backup correction process of the board | substrate direction in 2nd Embodiment.

  FIG. 1 is a front view showing a first embodiment of a drawing apparatus according to the present invention. FIG. 2 is a plan view of the drawing apparatus of FIG. FIG. 3 is a block diagram showing an electrical configuration of the drawing apparatus of FIG. The drawing apparatus is an apparatus that draws a pattern by irradiating the surface of a substrate W such as a wafer with light. The substrate W may be any of various substrates such as a semiconductor substrate, a printed substrate, and a glass substrate, but in the illustrated example, a circular wafer is used as the substrate.

  FIG. 4 is a diagram illustrating an example of a substrate on which a pattern is drawn by a drawing apparatus. The notch NT is formed in the peripheral part of this board | substrate W as shown in the figure, and the direction of the board | substrate W is recognizable by the said notch NT. A lattice-like scribe line SL is formed on the surface of the substrate W, and a plurality of light irradiation areas surrounded by the scribe line SL, that is, an exposure area ER is defined. On the scribe line SL, a plurality of alignment marks are formed at different positions. However, in the figure, only two alignment marks AM1 and AM2 used in the present invention are selectively illustrated. In the drawing, two selection examples are shown. In the present embodiment, the alignment marks AM1 and AM2 selected as shown in FIG. 4A are used as described later.

  Each alignment mark may be, for example, a rectangular mark having a side of about 0.1 mm (millimeter) (or a cross-shaped mark, or a mark in which a rectangular mark and a cross-shaped mark are overlapped) For example, a reflective layer (preferably aluminum or a metal layer) formed by a method such as vapor deposition. In this embodiment, as will be described later, two of these alignment marks are used for adjusting the direction and position of the substrate W, and one of them is referred to as “first alignment mark AM1” and the other is used as the other. This will be referred to as “second alignment mark AM2”. In the present embodiment, two divided surface regions (bisected regions) DR1 and DR2 formed by equally dividing the surface of the substrate W by a virtual line VL passing through the rotation center of the substrate W and extending in the Y direction are divided into two. On the other hand, the first alignment mark AM1 and the second alignment mark AM2 are respectively arranged. In the present embodiment, the first alignment mark AM1 and the second alignment mark AM2 are arranged point-symmetrically with respect to the rotation center of the substrate W. However, the alignment marks AM1, The arrangement position of AM2 is not limited to this.

  The drawing apparatus includes an exposure unit 100, a pre-alignment unit 200, a transport unit 300, a control unit 500, and the like in order to expose a pattern in the exposure region ER with the direction and position of the substrate W adjusted. Among these, the main components of the exposure unit 100, the pre-alignment unit 200, and the transport unit 300 are formed by attaching cover panels (not shown) to the ceiling surface and the peripheral surface of the skeleton formed by the main body frame 601. It is arranged inside the main body.

  As shown in FIGS. 1 and 2, the inside of the main body of the drawing apparatus is divided into a processing area 602 and a delivery area 603. Of these areas, the processing area 602 mainly includes a processing stage 1, a stage moving unit 2, a stage position measuring unit 3, an optical unit 4, and an alignment unit 5 that are the main components of the exposure unit 100. Then, the control unit 500 controls each part of the exposure unit 100 to expose the light beam to the exposure region ER of the substrate W and draw a pattern. On the other hand, the pre-alignment unit 200 and the transport unit 300 are arranged in the delivery area 603 as shown in FIG. The pre-alignment unit 200 performs a pre-alignment process. In addition, the transfer unit 300 includes a transfer robot 301 that loads and unloads the substrate W with respect to the processing region 602. In the present embodiment, two pre-alignment units 200 are arranged, but the number of pre-alignment units 200 is not limited to this, and is arbitrary.

  All of the pre-alignment units 200 have the same configuration. The pre-alignment unit 200 takes an image of the notch NT of the substrate W transported from the carrier C by the transport robot 301 and outputs an image signal of the notch NT corresponding to the rotation angle of the substrate W. It outputs to the control unit 500 and uses for a pre-alignment process. Then, the control unit 500 acquires the direction of the substrate W based on the image signal and adjusts the substrate direction. In order to execute the pre-alignment process, the pre-alignment unit 200 is provided with a pre-alignment table 210. The pre-alignment table 210 has an upper surface that supports the substrate W transported by the transport robot 301. A plurality of suction holes are formed on the upper surface of the pre-alignment table 210, and the substrate W is sucked and held on the pre-alignment table 210 by sucking each suction hole by a suction means (not shown). The Further, the pre-alignment table 210 is connected to the rotation shaft of the pre-alignment table drive motor 220 (FIG. 3), receives the rotation drive force from the motor 220, and rotates around the Z axis while holding the substrate W. .

  The pre-alignment unit 200 includes a notch imaging unit 230 in order to perform pre-alignment processing. The notch imaging unit 230 is disposed above the periphery of the substrate W held horizontally on the pre-alignment table 210. In the notch imaging unit 230, illumination light guided from an illuminating unit (not shown) is irradiated on the surface of the substrate W to illuminate a part of the peripheral portion, and reflected light reflected from the surface of the substrate W is notch imaged. Light is received by a CCD camera (not shown) of the unit 230, and an image of the peripheral part is taken.

  The image captured by the notch imaging unit 230 is given to the image processing unit 540 of the control unit 500, and the notch NT formed at the peripheral edge of the substrate W is recognized from the captured image, and a signal related to the notch NT is mainly used. It gives to the control part 510. Receiving this, the main control unit 510 acquires the rotation angle of the notch NT when the pre-alignment table 210 is stopped as substrate direction information. Then, the main controller 510 gives a drive command to the drive controller 530 based on the substrate direction information, and when the substrate W is transferred from the pre-alignment table 210 to the processing stage 1, the transfer robot 301 transfers the substrate W from the pre-alignment table 210. The substrate W is positioned with respect to the processing stage 1 by controlling reception, transfer of the substrate W, and placement of the substrate W on the processing stage 1. As described above, in the present embodiment, the pre-alignment process is executed in cooperation with the transport robot 301 based on the peripheral edge image of the substrate W imaged by the pre-alignment unit 200. Of course, before the transfer robot 301 receives the substrate W from the pre-alignment table 210, the pre-alignment table 210 of the pre-alignment unit 200 may be rotated based on the substrate direction information to complete the pre-alignment processing of the substrate W. .

  The processing stage 1 on which the pre-aligned substrate W is loaded has a flat plate-like outer shape, and functions as a holding unit that places and holds the substrate W in a horizontal posture on the upper surface thereof. A plurality of suction holes (not shown) are formed on the upper surface of the processing stage 1, and a negative pressure (suction pressure) is applied to the suction holes so that the substrate W placed on the processing stage 1 is removed. It can be fixedly held on the upper surface of the processing stage 1. Then, the processing stage 1 is moved by the stage moving unit 2.

  The stage moving unit 2 is a mechanism that moves the processing stage 1 in the main scanning direction (Y-axis direction), the sub-scanning direction (X-axis direction), and the rotation direction (rotation direction around the Z axis (θ-axis direction)). . The stage moving unit 2 includes a base plate 24 that supports a support plate 22 that rotatably supports the processing stage 1, a sub-scanning mechanism 23 that moves the support plate 22 in the sub-scanning direction X, and a base plate 24 that moves in the main scanning direction Y. And a main scanning mechanism 25 to be moved. The sub-scanning mechanism 23 and the main scanning mechanism 25 move the processing stage 1 in accordance with an instruction from the drive control unit 530 of the control unit 500. The stage moving unit 2 further includes a rotation mechanism 21 that aligns the direction of the substrate W by slightly rotating the processing stage 1 about the vertical axis.

  The sub-scanning mechanism 23 includes a linear motor 23 a configured by a moving element (not shown) attached to the lower surface of the support plate 22 and a stator (not shown) laid on the upper surface of the base plate 24. In addition, a pair of guide portions 23 b extending in the sub-scanning direction is provided between the support plate 22 and the base plate 24. For this reason, when the linear motor 23 a is operated, the support plate 22 moves in the sub-scanning direction X along the guide portion 23 b on the base plate 24.

  The main scanning mechanism 25 has a linear motor 25a composed of a mover attached to the lower surface of the base plate 24 and a stator laid on a base 606 of the drawing apparatus. A pair of guide portions 25b extending in the main scanning direction is provided between the base plate 24 and the base 606. For this reason, when the linear motor 25 a is operated, the base plate 24 moves in the main scanning direction Y along the guide portion 25 b on the base 606.

  The stage position measurement unit 3 is a mechanism that measures the position of the processing stage 1. The stage position measurement unit 3 is electrically connected to the input / output control unit 550 of the control unit 500 and measures the position of the processing stage 1 in accordance with an instruction from the control unit 500. The stage position measurement unit 3 is configured by a mechanism that measures the position of the processing stage 1 by irradiating laser light toward the processing stage 1 and using interference between the reflected light and the emitted light, for example. The configuration operation is not limited to this. In this embodiment, the stage position measurement unit 3 includes an emission unit 31 that emits laser light, a beam splitter 32, a beam bender 33, a first interferometer 34, and a second interferometer 35. The emission unit 31 and the interferometers 34 and 35 are electrically connected to the input / output control unit 550 and measure the position of the processing stage 1.

  The laser light emitted from the emission unit 31 first enters the beam splitter 32 and is branched into first branched light that goes to the beam bender 33 and second branched light that goes to the second interferometer 35. The first branched light is reflected by the beam bender 33, enters the first interferometer 34, and is irradiated from the first interferometer 34 to the first part of the processing stage 1. Then, the first branched light reflected by the first part is incident on the first interferometer 34 again. The first interferometer 34 is a position corresponding to the position of the first part based on the interference between the first branched light traveling toward the first part of the processing stage 1 and the first branched light reflected by the first part. Measure parameters.

  On the other hand, the second branched light is incident on the second interferometer 35 and the second part of the processing stage 1 from the second interferometer 35 (however, the second part is at a position different from the first part. ). Then, the second branched light reflected by the second part is incident on the second interferometer 35 again. The second interferometer 35 is configured so that the position of the second part is based on the interference between the second branched light traveling toward the second part of the processing stage 1 and the second branched light reflected by the second part of the processing stage 1. The position parameter corresponding to is measured.

  The main control unit 510 of the control unit 500 receives the position parameter corresponding to the position of the first part of the processing stage 1 and the second part of the processing stage 1 from each of the first interferometer 34 and the second interferometer 35. A position parameter corresponding to the position is acquired via the input / output control unit 550. Then, based on each acquired position parameter, the main control unit 510 calculates the position of the processing stage 1.

  The optical unit 4 has two optical heads 40a and 40b. Both the optical heads 40a and 40b have the same configuration, and modulate the laser light provided from the light irradiation unit 41 based on drawing data (run length data) corresponding to a pattern described by CAD (Computer Aided Design) data. To do. Here, the configuration related to the optical head 40a will be described with reference to FIG. 1, but the optical head 40b is configured similarly. The number of optical heads installed is not limited to this and is arbitrary.

  The light irradiation unit 41 includes a laser driving unit 411, a laser oscillator 412, and an illumination optical system 413. In the light irradiation unit 41, laser light is emitted from the laser oscillator 412 by the operation of the laser driving unit 411, and is introduced into the optical head 40 a via the illumination optical system 413. The optical head 40a is provided with a spatial light modulator, and modulates the laser light based on the drawing data. Then, the optical head 40a exposes the exposure region ER of the substrate W held on the processing stage 1 by directing the modulated laser light onto the substrate W moving at a position immediately below the optical head 40a, thereby drawing a pattern. To do. As a result, the pattern described in the CAD data is drawn on the pattern already formed in the exposure region ER of the substrate W.

  In the present embodiment, the optical head 40a is provided with an optical path correction unit (not shown), and light emitted from the spatial light modulation element (that is, light on which spatial modulation corresponding to drawing data is formed). ) Is shifted along the sub-scanning direction (X-axis direction). In the present embodiment, as the optical path correction unit, for example, as described in Japanese Patent Application Laid-Open No. 2012-93701, two wedge prisms and one wedge prism are arranged on the optical axis of incident light with respect to the other wedge prism. A wedge prism moving mechanism 420 (FIG. 3) that moves linearly along the direction (Z-axis direction) is employed. That is, the wedge prism moving mechanism 420 operates in response to a drive command from the drive control unit 530 to move one wedge prism, so that the optical path of incident light is a unit of spatial modulation (specifically, a spatial light modulator). It is possible to shift with finer precision than the pixel unit of the image exposed to the exposure area ER of the substrate W.

  The alignment unit 5 images two alignment marks AM1 and AM2 designated in advance. The alignment unit 5 includes an alignment mark imaging unit 51 having a lens barrel, an objective lens, and a CCD (Charge Coupled Device) image sensor, and a part of the surface of the substrate W can be enlarged and imaged. As described above, in the present embodiment, the alignment mark imaging unit 51 has an imaging region (reference numeral R in FIG. 7 described later) for partially imaging the surface of the substrate W, and collects the entire substrate surface in a lump. It is impossible to take an image. In this embodiment, an area image sensor (two-dimensional image sensor) is used as the CCD image sensor, but the present invention is not limited to this. Moreover, the alignment part 5 is supported by the raising / lowering mechanism which is not shown in figure so that raising / lowering is possible within a predetermined range.

  The illumination unit 7 is connected to the lens barrel through the fiber 71 and supplies illumination light to the alignment unit 5. The light guided by the fiber 71 extending from the illumination unit 7 is guided to the upper surface of the substrate W through the lens barrel of the alignment mark imaging unit 51, and the reflected light is received by the CCD image sensor through the objective lens. As a result, the upper surface of the substrate W is imaged and image data is acquired. Then, the alignment mark imaging unit 51 outputs the acquired imaging data to the image processing unit 540. The image processing unit 540 performs various image processing based on the imaging data and outputs a signal related to the coordinate position of the alignment marks AM1 and AM2 to the main control unit 510.

  In the control unit 500, a main control unit 510, a storage unit 520, a drive control unit 530, an image processing unit 540, and an input / output control unit 550 are interconnected via a bus line 560. The storage unit 520 stores the vector format design data 521 generated by an external CAD, the run length data (drawing data) 522 obtained by rasterizing the correction data obtained by correcting the design data 521 as will be described later, and the entire apparatus. A control program 523 and the like are stored. Then, a CPU (Central Processing Unit) which is a main component of the main control unit 510 controls each part of the apparatus via the drive control unit 530, the image processing unit 540, the input / output control unit 550, and the like according to the program. This program describes procedures for performing alignment processing for aligning the substrate W based on the coordinate positions of the alignment marks AM1 and AM2, drawing processing for drawing a pattern on the aligned substrate W, and the like. . And various functions are implement | achieved when CPU of the main-control part 510 performs arithmetic processing according to the said program. Specifically, the main control unit 510 applies a position information detection unit 511 that detects the coordinate positions of the alignment marks AM1 and AM2, a position adjustment unit 512 that adjusts the direction and position of the substrate W, and the substrate W by using modulated laser light. It functions as a drawing control unit 513 that draws a pattern.

  As described above, in the present embodiment, various functions are executed in software, but some or all of the functions realized by the main control unit 510 may be realized in hardware by a dedicated logic circuit or the like. Good. The program 523 is normally stored and used in the storage unit 520, but may be configured to be additionally or exchangeably stored in the storage unit 520 from the outside. Here, as an external provision mode, for example, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disk Read Only Memory), or a recording medium such as an external flash memory is provided. Alternatively, it may be provided by downloading from an external server via a network.

  Note that reference numerals 710 and 720 in FIG. 3 denote an input unit and a display unit, respectively, and an operator gives various commands and data to the control unit 500 via the input unit 710, and messages and operation statuses to the output unit 720. And the like can be output to the operator.

  FIG. 5 is a flowchart showing the operation of the drawing apparatus of FIG. FIG. 6 is a flowchart showing an operation for acquiring position information of the substrate loaded on the processing stage. FIG. 7 is a diagram schematically showing an operation of acquiring position information. Further, FIG. 8 is a diagram schematically showing the operation of positioning the substrate by adjusting the direction and position of the substrate. The operation of the drawing apparatus will be described below with reference to these drawings.

  In this drawing apparatus, the main control unit 510 performs various calculations and gives an operation command to each part of the apparatus, while each part of the apparatus operates as follows according to the operation command. First, the transfer robot 301 takes out the substrate W from the carrier C placed on the carrier placement unit 604 and carries it into the pre-alignment table 210 of one pre-alignment unit 200 (step S1). Subsequently, while the pre-alignment table 210 rotates at least once or more, the image processing unit 540 identifies the notch NT based on an image captured by the notch imaging unit 230 (hereinafter referred to as “peripheral image”), and The related signal is output to the main control unit 510. In response to this, the main control unit 510 acquires the rotation angle of the notch NT as substrate direction information indicating the direction of the substrate W for alignment processing (step S2).

  Next, the main control unit 510 executes position information acquisition processing (step S3). In this position information acquisition process, the main control unit 510 calculates a transport path of the substrate W by the transport robot 301 based on the substrate direction information, and drives and controls a command to transport the substrate W along the transport path. This is given to the transfer robot 301 via the unit 530. Then, the transfer robot 301 transfers the substrate W from the pre-alignment table 210 along the transfer path, and transfers the substrate W onto the processing stage 1 (step S31). During this time, the direction of the substrate W is adjusted with respect to the processing stage 1 (pre-alignment).

  Further, when loading the substrate W onto the processing stage 1, the main control unit 510 determines the transfer path with reference to the position coordinate data of the first alignment mark AM 1 including the design data 521, and the middle part of FIG. As shown, the substrate W is transferred to the processing stage 1 so that the first alignment mark AM1 is positioned in the imaging region R. Accordingly, when the transfer of the substrate W to the processing stage 1 is completed, the substrate W is in a state in which the notch NT is substantially directed in the target direction and the first alignment mark AM1 can be immediately imaged on the processing stage 1. Positioned. In addition, the upper stage part in FIG. 7 has shown the state before board | substrate transfer.

  When the transfer of the substrate W is completed, an image including the first alignment mark AM1 is imaged by the alignment mark imaging unit 51 (step S32). Then, the image processing unit 540 performs various image processing on the captured data. Based on the image processing result, the main controller 510 detects position information indicating the coordinate position of the first alignment mark AM1 (step S33).

  In the next step S34, the main control unit 510 refers to the position coordinate data of the second alignment mark AM2 including the design data 521 in order to detect the position information of the second alignment mark AM2. Is determined as follows. That is, the movement path of the processing stage 1 necessary for transition from the state where the first alignment mark AM1 is located in the imaging region R to the state where the second alignment mark AM2 is located in the imaging region R is calculated. Then, the processing stage 1 is moved along the movement path, and the second alignment mark AM2 is positioned in the imaging region R as shown in the lower part of FIG. 7 (step S34).

  When the movement of the substrate W is completed, an image including the second alignment mark AM2 is imaged by the alignment mark imaging unit 51 (step S35). Then, similarly to the case of the first alignment mark AM1, the main control unit 510 detects position information indicating the coordinate position of the second alignment mark AM2 (step S36).

  When the two pieces of position information are acquired in this way, the main control unit 510 calculates how much the substrate W is rotationally displaced from the target direction, that is, the rotation amount θ of the substrate W (step S37). In the present embodiment, the rotation amount θ indicates not only the magnitude of rotation but also the rotation direction. That is, when the value is a positive value, for example, as shown in FIGS. 7 and 8, the substrate W is rotated clockwise by an absolute value | θ | with respect to the target direction as viewed from above in the vertical direction. Conversely, when the value is negative, it indicates that the substrate W is rotated counterclockwise by the absolute value | θ | with respect to the target direction when viewed from above in the vertical direction.

In next step S4, main controller 510 determines whether or not absolute value | θ | of rotation amount θ is within an appropriate angle range. The “appropriate angle range” means a range in which the stage position measuring unit 3 can appropriately measure the rotational position of the processing stage 3. That is, in the stage position measurement unit 3 configured as described above, when the absolute value | θ | of the rotation amount θ of the processing stage 1 increases, the reflected light of the laser beam cannot be taken into the interferometers 34 and 35. The rotational position of the processing stage 1 cannot be measured.

  Therefore, in the present embodiment, the determination is performed in order to avoid the processing stage 1 from rotating beyond the appropriate angle range. More specifically, when the absolute value | θ | of the rotation amount θ exceeds the appropriate angle range, that is, when it is determined “NO” in step S4, the main control unit 510 rotates the processing stage 1. Instead, the substrate W is transferred from the processing stage 1 to the pre-alignment table 210 by the transfer robot 301 and transferred onto the pre-alignment table 210 (step S5). Then, the processing after the pre-alignment, that is, the pre-alignment processing (step S2) and the position information acquisition processing (step S3) are executed again. By repeating such processing, the pre-alignment accuracy is improved so that the absolute value | θ | of the rotation amount θ is within an appropriate angle range. When such re-prealignment operation is repeated a plurality of times, the drawing process for the substrate W may be stopped.

  When it is confirmed in step S4 that the absolute value | θ | of the rotation amount θ is within the appropriate angle range, the main control unit 510 gives a rotation command to the rotation mechanism 21 via the drive control unit 530, and processing is performed. The stage 1 is rotated by the rotation amount (−θ) (step S6). As a result, when the position information acquisition is completed, it is assumed that the alignment marks AM1 and AM2 on the substrate W are shifted from the target positions AM01 and AM02 by rotating and moving from the target direction by the rotation amount θ as shown on the left side of FIG. However, when the processing stage 1 is rotated by the rotation amount (−θ), the alignment marks AM1 and AM2 are close to or coincide with the target positions AM01 and AM02, respectively, as shown on the right side of FIG. Aligned in the direction. Thus, the alignment process for the substrate W is completed.

  Further, the main control unit 510 compares the position information indicating the coordinate positions of the alignment marks AM1 and AM2 with the coordinates of the target positions AM01 and AM02, and calculates the amount of expansion / contraction of the substrate W in the X direction and the Y direction. In this embodiment, the two alignment marks AM1 and AM2 are arranged substantially symmetrically in the X direction with the virtual line VL interposed therebetween as shown in FIG. 4A. It can be calculated almost accurately based on the above. On the other hand, regarding the amount of expansion / contraction in the Y direction, it is assumed that the expansion / contraction in the X direction and the Y direction are substantially the same, or based on the amount of expansion / contraction in the X direction after taking into account the expansion / contraction characteristics of the substrate measured in advance. To estimate the amount of expansion and contraction in the Y direction.

  As described above, the arrangement positions of the alignment marks AM1 and AM2 are not limited to those shown in FIG. 4A, but differ depending on the division mode of the divided surface regions DR1 and DR2. For example, the substrate surface is divided into two equal parts by a virtual line VL that passes through the rotation center of the substrate W and extends in the X direction, so that two divided surface regions are formed, and the alignment marks AM1 and AM2 sandwich the virtual line VL and Y In some cases, the two divided surface regions are arranged so as to be substantially symmetric in the direction. In this case, contrary to the case of this embodiment, the amount of expansion / contraction in the Y direction is calculated based on the detected position information, while the amount of expansion / contraction in the X direction is calculated based on the amount of expansion / contraction in the Y direction. Estimate the amount of expansion and contraction. Further, as shown in FIG. 4B, when the X and Y coordinates of the alignment marks AM1 and AM2 are greatly different from each other, the position information that detects the expansion / contraction amount in the X direction and the Y direction is used. Can be calculated based on this.

  Thus, the alignment process (step S6) for aligning the direction and position of the substrate W with the target position is completed, or in parallel with the alignment process, the main control unit 510 performs patterning based on the position information of the alignment marks AM1 and AM2. The amount of deviation from the ideal position is obtained. In other words, the design data 521 includes information regarding a pattern to be drawn in each exposure area ER, that is, pattern data. In order to accurately draw a pattern in each exposure region ER, the main control unit 510 reflects the shift amount and the expansion / contraction amount in the design data 521 to perform coordinate correction and rotation correction, and the corrected design data ( (Hereinafter referred to as “correction design data”) is temporarily stored in the storage unit 520 (step S7). Further, the main control unit 510 executes rasterization processing of the corrected design data, generates run length data (drawing data) 512, and stores it in the storage unit 520.

  When both the alignment process and the run length data generation process are completed, the main control unit 510 reads the run length data 512 from the storage unit 520 and controls each part of the apparatus according to the run length data 512 to control the exposure area ER of the substrate W. A pattern is drawn for (step S8). When the drawing process is completed, the transfer robot 301 receives the drawn substrate W from the processing stage 1 in accordance with an unloading instruction from the main control unit 510 and carries it out to the cassette C (step S9).

  As described above, in the first embodiment, after imaging the first alignment mark AM1 by the alignment mark imaging unit 51, the processing stage 1 is set so that the second alignment mark AM2 is positioned in the imaging region R of the alignment mark imaging unit 51. Move. Then, the alignment mark imaging unit 51 images the second alignment mark AM2, and the processing stage 1 is moved based on the positional information of both alignment marks AM1 and AM2, and the direction and position of the substrate W are adjusted. Therefore, the number of times of moving the substrate W for obtaining the position information can be minimized, and the time required for the direction and position of the substrate W can be shortened. As a result, the productivity of the drawing apparatus can be increased.

  In the first embodiment, the substrate W is positioned on the processing stage 1 so that the first alignment mark AM1 is included in the imaging region R by the transfer of the substrate W to the processing stage 1 by the transfer robot 301 ( Step S31). Therefore, the first alignment mark AM1 can be imaged immediately after the transfer of the substrate W, and the throughput can be further improved. In the present embodiment, the first alignment mark AM1 is the “pre-shooting alignment mark” of the present invention and the second alignment mark AM2 is the “post-shooting alignment mark” of the present invention, but this may be replaced. That is, one of the two alignment marks can be a “pre-shooting alignment mark” and the other can be a “post-shooting alignment mark”.

  Further, if the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, and the processing stage 1 is rotated by the rotation amount, the stage position measuring unit 3 measures the rotational position of the processing stage 1. It may happen that it becomes impossible. In this case, since it is considered that the pre-alignment process is not sufficient, in this embodiment, the processing stage 1 is not rotated, the substrate W is returned from the processing stage 1 to the pre-alignment table 210, and the processes after the pre-alignment are performed again. Running. Therefore, since the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, it is possible to reduce the frequency of occurrence of the problem that the substrate W is not subjected to the drawing process. Yield can be improved. Further, excessive rotation driving of the processing stage 1 can be prevented in advance, and machine troubles can be effectively prevented.

  In the first embodiment, when the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, the processes after the pre-alignment are re-executed. The alignment process of the substrate W may be executed by operating each part of the drawing apparatus as follows (second embodiment). Hereinafter, the second embodiment will be described with reference to FIGS. 9 and 10.

  FIG. 9 is a flowchart showing the operation of the second embodiment of the drawing apparatus according to the present invention. The second embodiment is greatly different from the first embodiment in a coping operation when it is determined that the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, and other operations. The basic configuration of the apparatus is the same. Therefore, in the following description, differences will be mainly described, and the same configurations and the same operations will be denoted by the same reference numerals, and description thereof will be omitted.

  Also in the second embodiment, as in the first embodiment, when the substrate W is carried from the carrier C to the pre-alignment table 210 by the transfer robot 301 (step S1), the substrate direction information of the substrate W is obtained by the pre-alignment unit 200. Is acquired (step S2). Then, position information acquisition processing (step S3) is executed, the substrate W is transferred to the processing stage 1, and the rotation amount of the substrate W is calculated.

  If the main control unit 510 determines that the absolute value | θ | of the rotation amount θ exceeds the appropriate angle range, the main control unit 510 re-executes position information acquisition processing after executing steps S10 to S14. . That is, in step S10, the main control unit 510 determines whether or not the absolute value | θ | of the rotation amount θ exceeds the enlarged angle range obtained by expanding the appropriate angle range three times. Here, the “enlarged angle range” is used as a reference in consideration of the effectiveness of the preliminary correction processing (steps S11 to S15) in the substrate direction described below. When it is confirmed in step S10 that the absolute value | θ | of the rotation amount θ exceeds the enlargement angle range (= appropriate angle range × 3), the main control unit 510 has properly performed the pre-alignment process. In addition, it is determined that the preliminary correction process in the substrate direction is not applicable. In step S9, the substrate W is unloaded from the processing stage 1 by the transfer robot 301 without executing the drawing process (step S8). On the other hand, when it is confirmed that the absolute value | θ | of the rotation amount θ is within the enlargement angle range (determined as “YES” in step S10), the main control unit 510 controls the rotation mechanism 21 and the transport robot 301. Then, preliminary correction processing in the substrate direction is executed (steps S11 to S15).

  FIG. 10 is a diagram schematically showing a preliminary correction process in the substrate direction in the second embodiment. Note that reference numeral VP in the figure is a virtual point assigned to visualize the rotation state of the processing stage 1 and is not actually attached to the processing stage 1. Since the preliminary correction process is started after the second alignment mark AM2 is imaged, the processing stage 1 holds the substrate W while the second alignment mark AM2 is held as shown in FIG. It is positioned so as to be located in the imaging region R. In this state, the main control unit 510 gives a rotation command to the rotation mechanism 21 via the drive control unit 530, and rotates the processing stage 1 by (−θ) / 2 (step S11). That is, the processing stage 1 is rotated by an amount half the absolute value | θ | of the rotation amount θ in the direction opposite to the rotation direction in which the direction of the substrate W is shifted from the target direction (clockwise in FIG. 10). As a result, the substrate W is also rotated by (−θ) / 2.

  Subsequently, the main control unit 510 gives a pickup command to the transfer robot 301 via the drive control unit 530. Then, the transfer robot 301 picks up the substrate W from the processing stage 1 and separates it above the processing stage 1 as shown in FIG. 10B (step S12). While maintaining the separated state, the main control unit 510 gives a rotation command to the rotation mechanism 21 via the drive control unit 530, and rotates the processing stage 1 by (θ) (step S13). As a result, the substrate W remains rotated by (−θ) / 2, whereas the processing stage 1 rotates (θ) / 2 from the original state.

  In the next step S <b> 14, the main control unit 510 gives a drop-off command to the transfer robot 301 via the drive control unit 530, and returns the substrate W to the processing stage 1. Further, the main control unit 510 gives a rotation command to the rotation mechanism 21 via the drive control unit 530, and returns the processing stage 1 to the original state as shown in FIG. 10C (step S15). As a result, the direction of the substrate W is corrected by (−θ). And it returns to step S3 and the acquisition process of a positional information is performed. However, since the second alignment mark AM2 is currently positioned in the imaging region R as shown in FIG. 10C, imaging and position information detection of the second alignment mark AM2 are executed prior to the first alignment mark AM1. Is done. That is, in the position information acquisition process (step S3) performed following the preliminary correction process, the second alignment mark AM2 corresponds to the “preliminary alignment mark” of the present invention, and the first alignment mark AM1 is “ This corresponds to “post-shoot alignment mark”. Then, imaging of the second alignment mark AM2, detection of position information of the second alignment mark AM2, movement of the processing stage 1, imaging of the first alignment mark AM1, and detection of position information of the first alignment mark AM1 are performed in this order. After that, the rotation amount θ of the substrate W that has undergone the preliminary correction process is calculated. Therefore, by performing the preliminary correction process, the absolute value | θ | of the rotation amount θ can be suppressed within an appropriate angle range, and then the (−θ) rotation (step) of the processing stage 1 is performed as in the first embodiment. After performing S6) and pattern data correction (Step S7), the drawing process (Step S8) can be executed.

  As described above, also in the second embodiment, similarly to the first embodiment, the number of movements of the substrate W in the position information acquisition process (step S3) can be minimized, and the direction and position of the substrate W can be reduced. Can be shortened. As a result, the productivity of the drawing apparatus can be increased.

  Further, when the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, the preliminary correction processing (steps S11 to S15) shown in FIG. 10 is performed without rotating the processing stage 1. Then, after correcting the direction of the substrate W by (−θ), the position information acquisition process (step S3) is re-executed. Therefore, the yield of the drawing process can be improved as in the first embodiment. In addition, since it is not necessary to perform the pre-alignment process again, the drawing process can be performed with a shorter tact time than in the first embodiment, and the productivity of the drawing apparatus can be further increased. Further, similarly to the first embodiment, excessive rotation driving of the processing stage 1 can be prevented in advance, and problems such as machinery can be effectively prevented.

  As described above, in the first and second embodiments, the rotation mechanism 21, the sub-scanning mechanism 23, and the main scanning mechanism 25 correspond to an example of the “stage moving unit” of the present invention. The alignment mark imaging unit 51 corresponds to an example of the “imaging unit” of the present invention. The main control unit 510 functions as a “position information detection unit” and a “position adjustment unit” of the present invention. That is, in the embodiment of the drawing apparatus, the processing stage 1, the stage moving unit (the rotation mechanism 21, the sub-scanning mechanism 23, the main scanning mechanism 25), the alignment mark imaging unit 51, and the main control unit 510, Is configured. The main control unit 510 also functions as a “drawing control unit” of the present invention. Further, the transfer robot 301 corresponds to an example of the “transfer unit” of the present invention. Further, the absolute value | θ | corresponds to the “rotation absolute value” of the present invention, and the appropriate angle range corresponds to an example of the “predetermined angle range” 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 present invention. For example, in the above embodiment, the present invention is applied to a drawing technique for drawing another pattern with respect to an existing pattern on the substrate surface, but the pattern is applied to a semiconductor chip mounted on the substrate surface. The present invention can also be applied to a technique for drawing. In addition, the application target of the positioning device according to the present invention is not limited to the drawing device, and the substrate is aligned using the alignment mark on the substrate, and then the substrate is processed. The present invention can be applied to all substrate processing apparatuses.

  When the absolute value | θ | of the rotation amount θ of the substrate W exceeds the appropriate angle range, the pre-alignment process is re-executed in the first embodiment, and the preliminary correction process (steps S11 to S11) is performed in the second embodiment. Although S15) is executed, these processes are not essential but optional. That is, in the above case, the substrate may be carried out by the transfer robot 301 without rotating the processing stage 1 and performing the drawing process.

  In the above embodiment, the processing stage 1 is moved to adjust the position of the substrate. However, the position of the substrate is adjusted by moving the optical heads 40 a and 40 b, or the wedge prism moving mechanism 420 is used to adjust the wedge prism. You may comprise so that it may move and finely adjust.

  In the above-described embodiment, only the mode (high-speed alignment mode) in which alignment processing is performed using the two alignment marks AM1 and AM2 is provided. However, as in the prior art, alignment is performed based on, for example, four alignment marks. Modes for processing (high-precision alignment mode) may be added, and these modes may be selectively executed.

  The present invention is applicable to a positioning technique for aligning the rotational position of a substrate having two alignment marks with a target position and a drawing apparatus equipped with the positioning technique.

DESCRIPTION OF SYMBOLS 1 ... Processing stage 2 ... Stage moving part 5 ... Alignment part 21 ... Rotation mechanism 23 ... Sub-scanning mechanism 25 ... Main scanning mechanism 40a, 40b ... Optical head 51 ... Alignment mark imaging part 200 ... Pre-alignment unit (pre-alignment part)
301 ... Conveying robot (conveying unit)
DESCRIPTION OF SYMBOLS 500 ... Control unit 510 ... Main control part 511 ... Position information detection part 512 ... Position adjustment part 513 ... Drawing control part 520 ... Storage part 521 ... Design data AM1 ... 1st alignment mark AM2 ... 2nd alignment mark DR1, DR2 ... Division Surface area (bisected area)
R ... Imaging area W ... Substrate

Claims (10)

A stage for holding a substrate on which a first alignment mark and a second alignment mark are formed;
A stage moving unit for moving the stage;
An imaging region that partially images the surface of the substrate held by the stage, and images the first alignment mark when the first alignment mark is positioned in the imaging region; An imaging unit that captures an image of the second alignment mark when the second alignment mark is positioned at
A position information detector that detects position information of the first alignment mark from the image of the first alignment mark and detects position information of the second alignment mark from the image of the second alignment mark;
One of the first alignment mark and the second alignment mark is a pre-shoot alignment mark and the other is a post-shoot alignment mark, and the post-shoot alignment mark is captured after the pre-shoot alignment mark is imaged by the imaging unit. A position adjusting unit that moves the stage so as to be positioned in an imaging region and moves the stage based on positional information of the first alignment mark and the second alignment mark to adjust the direction and position of the substrate; A positioning device comprising: a positioning device; The positioning device according to claim 1,
A pre-alignment unit for adjusting the direction of the substrate;
A transport unit that accesses the pre-alignment unit and the stage and transports the substrate;
The transporting unit is a positioning device that transports the substrate from the pre-alignment unit onto the stage so that the direction of the substrate faces a target direction. The positioning device according to claim 2,
The transporting unit is a positioning device that transports the substrate onto the stage so that the pre-alignment alignment mark is positioned in the imaging region. A positioning device according to claim 2 or 3, wherein
The stage moving unit has a rotation mechanism capable of rotating the stage within a predetermined angle range,
The position adjusting unit is a positioning device that adjusts the direction of the substrate by rotating the stage by the rotation mechanism. The positioning device according to claim 4,
The position adjustment unit obtains a rotation absolute value and a rotation direction of the stage necessary for adjusting the direction of the substrate based on position information of the first alignment mark and the second alignment mark, and calculates the rotation absolute value of the stage. A positioning device that stops rotation of the stage when it is determined that the angle exceeds the angular range. The positioning device according to claim 5,
The transporting unit is a positioning device that transports the substrate, whose rotation of the stage has been stopped, to the pre-alignment unit and re-executes processing after pre-alignment. The positioning device according to claim 5,
The position adjustment unit rotates the processing stage in a direction opposite to the rotation direction of the stage in a state where the substrate on the stage whose rotation has been stopped is separated from the stage by the transport unit, A positioning apparatus that re-transports the substrate onto the stage by the transport unit and re-executes processing after imaging of the first alignment mark. A positioning device according to any one of claims 1 to 7,
The positioning device in which the first alignment mark is formed in one of the bisected regions obtained by dividing the surface of the substrate into two halves, and the second alignment mark is formed in the other of the bisected regions. One of the first alignment mark and the second alignment mark formed on the surface of the substrate held on the stage is used as a pre-shooting alignment mark, and the other is used as a post-shooting alignment mark. Imaging the pre-alignment alignment mark in an imaging region;
Moving the stage holding the substrate on which the pre-shooting alignment mark has been imaged, so that the post-shooting alignment mark is positioned in the imaging area;
Imaging the post-shoot alignment mark;
Detecting the position information of the first alignment mark from the image of the first alignment mark and detecting the position information of the second alignment mark from the image of the second alignment mark;
And a step of adjusting the direction and position of the substrate by moving the stage based on positional information of the first alignment mark and the second alignment mark. A positioning device according to any one of claims 1 to 8,
An optical head that draws a pattern described by design data by irradiating light onto the surface of the substrate held by the stage;
A drawing control unit that controls drawing of the pattern on the substrate based on corrected design data obtained by correcting the design data based on position information of the first alignment mark and the second alignment mark. Characteristic drawing device.

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