Drawing device and drawing method

Abstract

To provide a technique for performing drawing with light while moving a state mounted with a substrate which can measure the position of the stage by the principle of a linear encoder, without causing the increase in the size and cost of a device.SOLUTION: A drawing device and a drawing method move a stage having a substrate mounted on its upper surface, and irradiate a substrate with light from a drawing part and perform drawing while alternately executing main scanning movement in a main scanning direction and sub-scanning movement in a sub-scanning direction which cross each other. The device and the method read out a linear scale which is provided integrally with the stage and is formed with a scale in the main scanning direction, by a read-out head, and thereby detects a relative position between the drawing part and the stage in the main scanning direction, and moves the read-out head by only a moving amount according to the moving amount of the stage when the stage is moved in the sub-scanning direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a technique for drawing a pattern on a substrate such as a semiconductor substrate, a semiconductor package substrate, a printed wiring board, or a glass substrate. [Background technology]

[0002] As a technique for forming a pattern such as a wiring pattern on various substrates such as a semiconductor substrate, a semiconductor package substrate, a printed wiring substrate, and a glass substrate, there is a technique for exposing a photosensitive layer formed on a surface of the substrate by irradiating the substrate with light according to a pattern to be formed. For example, Patent Document 1 describes an apparatus for irradiating a substrate with a light beam modulated according to a pattern to be drawn, thereby drawing a predetermined pattern on the substrate. In addition, Patent Document 2 describes an apparatus for drawing a pattern by irradiating a substrate with exposure illumination light through a reticle corresponding to the pattern shape.

[0003] In these imaging devices, partial exposure is performed multiple times while changing the incident position of light in order to perform imaging on the entire substrate. Specifically, exposure is performed while performing a so-called step-and-repeat or step-and-scan scanning movement in which a main scanning movement in which a stage on which a substrate is placed is moved in the main scanning direction and a sub-scanning movement in which the stage is stepped in a sub-scanning direction intersecting the main scanning movement are alternately performed.

[0004] In order to perform drawing at an appropriate position on the substrate, it is necessary to accurately measure the stage position during scanning movement. For this purpose, the technology described in Patent Document 1 uses a position measurement unit that uses a laser interferometer. On the other hand, in the technology described in Patent Document 2, the stage position is measured by a linear encoder that optically reads a two-dimensional scale formed on the measurement stage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-169549 A [Patent Document 2] Patent No. 5035247 Summary of the Invention [Problem to be solved by the invention]

[0006] Among these position measurement technologies, the laser interferometer method has been the most widely used so far because of its superior measurement accuracy, resolution, and long-term stability. However, when trying to further improve measurement accuracy, short-term fluctuations in measurement values ​​caused by temperature fluctuations in the atmosphere along the optical path of the laser light have become a major error factor.

[0007] On the other hand, the performance of the linear encoder method has also improved in recent years, and in particular, those with resolution equal to or higher than that of the laser interferometer method have been put into practical use. However, in the position measurement technology of the linear encoder method, it is necessary to arrange the linear scale on which the scale is engraved and the reading head that reads it facing each other. Therefore, in order to combine it with the step-and-repeat method or step-and-scan method of stage movement involving movement in the main scanning direction and the sub-scanning direction, it is necessary to arrange many reading heads to cover the entire moving range of the stage, as described in Patent Document 2.

[0008] In particular, in the current situation where patterns are becoming finer and substrates are becoming larger, it has become necessary to perform step feed in the sub-scanning direction multiple times for one substrate, and multiple reading heads are required to accommodate such a range of movement, which leads to larger equipment and higher costs, a problem that remains with the conventional technology.

[0009] The present invention has been made in consideration of the above-mentioned problems, and has an object to enable stage position measurement based on the principles of a linear encoder, in a technology for performing optical drawing while moving a stage on which a substrate is placed, without increasing the size and cost of the apparatus. [Means for solving the problem]

[0010] One aspect of the present invention is a drawing device including a stage on an upper surface of which a substrate can be placed, a drawing unit that irradiates light onto the substrate placed on the stage to draw on the substrate, a first movement mechanism that moves the stage relative to the drawing unit to perform main scanning movement in a main scanning direction parallel to the upper surface and intersecting with each other, and sub-scanning movement in a sub-scanning direction intersecting with the main scanning direction, and a position detection unit that detects a relative position between the drawing unit and the stage in the main scanning direction. In this drawing device, the position detection unit includes a linear scale that is provided integrally with the stage and has a scale formed along the main scanning direction, a reading head that reads the scale, and a second movement mechanism that moves the reading head in the sub-scanning direction relative to the drawing unit, and when the stage is moved in the sub-scanning direction by the first movement mechanism, the second movement mechanism moves the reading head by an amount corresponding to an amount of movement of the stage.

[0011] In the invention configured in this way, the position of the stage in the main scanning direction is detected by the reading head reading the scale (gradations) of the linear scale that extends in the main scanning direction and moves integrally with the stage. That is, the position detection unit measures the main scanning direction position of the stage using the measurement principle of the linear encoder method. Meanwhile, when the stage moves in the sub-scanning direction, the reading head is moved in the sub-scanning direction by an amount corresponding to the amount of movement.

[0012] Therefore, when the linear scale, which moves integrally with the stage, moves in the sub-scanning direction, the read head also moves in the sub-scanning direction following this. Therefore, by reading the scale with the read head after movement, it is possible to continue detecting the position of the stage. Thus, according to the present invention, even if the number of movements of the stage in the sub-scanning direction increases, there is no need to increase the number of installed read heads, and the position of the stage can be detected using a small number of read heads.

[0013] Another aspect of the present invention is a drawing method in which a stage with a substrate placed on its upper surface is moved, and main scanning movement in a main scanning direction parallel to the upper surface and intersecting with each other, and sub-scanning movement in a sub-scanning direction intersecting the main scanning direction are alternately performed, while irradiating light from a drawing unit onto the substrate to draw, in which a reading head detects the relative position of the drawing unit and the stage in the main scanning direction by reading a linear scale that is integral with the stage and has a scale formed along the main scanning direction, and when the stage moves in the sub-scanning direction, the reading head is moved by an amount corresponding to the amount of movement of the stage.

[0014] In the invention configured in this manner, by using the same principle as the above-mentioned drawing device invention, it is possible to detect the position of the stage using a small number of reading heads even when the number of times the stage moves in the sub-scanning direction is large. Effect of the Invention

[0015] As described above, according to the present invention, when the stage position is detected by a linear encoder configured by a pair of a linear scale and a read head, the read head also moves in the sub-scanning direction in response to the sub-scanning movement of the stage. Therefore, even if the stage moves many times in the sub-scanning direction, position detection is possible with a small number of read heads, and it is possible to prevent the device from becoming larger and more expensive. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a front view showing a schematic diagram of a first embodiment of a drawing device according to the present invention. [Diagram 2] 2 is a block diagram showing an example of an electrical configuration of the exposure apparatus in FIG. 1. [Diagram 3] FIG. 2 is a view showing the main part of the exposure device as viewed in the Y direction. [Figure 4] FIG. 2 is a perspective view showing a schematic configuration of a stage driving mechanism. [Diagram 5] FIG. 13 is a diagram showing an example of a configuration in which two sets of exposure heads are provided. [Figure 6]3A to 3C are diagrams illustrating the principle of position detection in a position detection mechanism. [Figure 7] 5 is a flowchart showing the processing content of an exposure operation in this embodiment. [Figure 8] FIG. 4 is a diagram showing the manner in which a stage and a read head move. [Figure 9] 13 is a diagram showing the main parts of the exposure apparatus of the second embodiment as viewed in the Y direction. [Figure 10] FIG. 2 is a perspective view showing a schematic configuration of a stage driving mechanism and its surroundings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment Fig. 1 is a front view showing a schematic configuration of an exposure apparatus as a first embodiment of a drawing apparatus according to the present invention, and Fig. 2 is a block diagram showing an example of an electrical configuration of the exposure apparatus of Fig. 1. In Fig. 1 and the following figures, the X direction which is the horizontal direction, the Y direction which is the horizontal direction perpendicular to the X direction, the Z direction which is the vertical direction, and a rotation direction θ about a rotation axis parallel to the Z direction are shown as appropriate.

[0018] The exposure device 1 draws a pattern on a photosensitive material by irradiating a substrate S (substrate to be exposed) on which a layer of a photosensitive material such as resist is formed with a laser beam of a predetermined pattern. As the substrate S, various substrates such as a semiconductor substrate, a semiconductor package substrate, a printed wiring substrate, and a glass substrate for various display devices can be used. In addition, the shape of the substrate S is not particularly limited, and for example, a disk-shaped substrate, a rectangular substrate, an irregular substrate processed into a specific outline, and the like can be used as the substrate S.

[0019] The exposure apparatus 1 includes a main body 11, which is composed of a main body frame 111 and a cover panel (not shown) attached to the main body frame 111. Various components of the exposure apparatus 1 are disposed both inside and outside the main body 11.

[0020] The inside of the main body 11 of the exposure apparatus 1 is divided into a processing region 112 and a transfer region 113. In the processing region 112, mainly, a stage 2, a stage driving mechanism 3, an exposure unit 4, an alignment unit 5, and a position detection mechanism 8 are arranged. Each of these parts is arranged on a base part 100, or is attached to a gantry-shaped support frame 101 arranged so as to straddle the base part 100. In addition, an illumination unit 6 that supplies illumination light to the alignment unit 5 is arranged outside the main body 11. In the transfer region 113, a transport device 7 such as a transport robot that transports the substrate S to and from the processing region 112 is arranged. Furthermore, a control unit 9 is arranged inside the main body 11, and the control unit 9 is electrically connected to each part of the exposure apparatus 1 to control the operation of each of these parts.

[0021] The transport device 7 arranged in the transfer area 113 inside the main body 11 receives an unprocessed substrate S from an external transport device or substrate storage device (not shown) and transports (loads) it into the processing area 112, and also transports (unloads) the processed substrate S from the processing area 112 and sends it out to the outside. The loading of the unprocessed substrate S and the unloading of the processed substrate S are performed by the transport device 7 in response to instructions from the control unit 9.

[0022] Stage 2 has a flat plate-like outer shape and holds substrate S placed on its upper surface in a horizontal position. A plurality of suction holes (not shown) are formed in the upper surface of stage 2, and substrate S placed on stage 2 is fixed to the upper surface of stage 2 by applying negative pressure (suction pressure) to these suction holes. Stage 2 is driven by stage driving mechanism 3.

[0023] The stage driving mechanism 3 is an XYZ-θ driving mechanism that moves the stage 2 in the Y direction (main scanning direction), X direction (sub-scanning direction), Z direction, and rotational direction θ (yaw direction). The stage driving mechanism 3 has a Y-axis robot 31 which is a single-axis robot extending in the Y direction, a Y-moving table 32 which is driven in the Y direction by the Y-axis robot 31, an X-axis robot 33 which is a single-axis robot extending in the X direction on the upper surface of the Y-moving table 32, an X-moving table 34 which is driven in the X direction by the X-axis robot 33, and a θ-axis robot 35 which drives the stage 2 supported on the upper surface of the X-moving table 34 in the rotational direction θ relative to the X-moving table 34.

[0024] Therefore, the stage driving mechanism 3 can drive the stage 2 in the Y direction by the Y-axis servo motor of the Y-axis robot 31, drive the stage 2 in the X direction by the X-axis servo motor of the X-axis robot 33, and drive the stage 2 in the rotation direction θ by the θ-axis servo motor of the θ-axis robot 35. These servo motors are not shown. The stage driving mechanism 3 can also drive the stage 2 in the Z direction by the Z-axis robot 37. The stage driving mechanism 3 moves the substrate S placed on the stage 2 by operating the Y-axis robot 31, the X-axis robot 33, the θ-axis robot 35, and the Z-axis robot 37 in response to a command from the control unit 9.

[0025] A position detection mechanism 8 is provided to detect the position of the stage 2 moved in this manner. Specifically, the position detection mechanism 8 has a linear scale 81 extending in the Y direction on the upper surface of the stage 2, and a read head 82 attached to the support frame 101 for reading the scale (gradations) engraved on the linear scale 81; these together form a linear encoder. The output of the read head 82 is input to the control unit 9.

[0026] The exposure unit 4 has an exposure head 41 arranged above the substrate S on the stage 2, and a light irradiation unit 40 including a light source driving unit 42, a laser emission unit 43, and an illumination optical system 44, which irradiates laser light onto the exposure head 41. A plurality of exposure units 4 may be provided at different positions in the X direction.

[0027] Laser light emitted from a laser emission unit 43 by operation of a light source drive unit 42 is irradiated onto an exposure head 41 via an illumination optical system 44. The exposure head 41 modulates the laser light emitted from a light irradiation unit 40 by a spatial light modulator 400 (hereinafter sometimes simply referred to as an "optical modulator"), and irradiates the modulated laser light onto a substrate S moving directly below it. By exposing the substrate S to a laser light beam in this manner, a pattern is drawn on the substrate S (exposure operation).

[0028] The alignment unit 5 has an alignment camera 51 arranged above the substrate S on the stage 2. This alignment camera 51 has a lens barrel, an objective lens, and a CCD image sensor, and captures an image of an alignment mark provided on the top surface of the substrate S moving directly below it. The CCD image sensor provided in the alignment camera 51 is composed of, for example, an area image sensor (two-dimensional image sensor).

[0029] The illumination unit 6 is connected to the lens barrel of the alignment camera 51 via an optical fiber 61, and supplies illumination light to the alignment camera 51. The illumination light guided by the optical fiber 61 extending from the illumination unit 6 is guided to the upper surface of the substrate S via the lens barrel of the alignment camera 51, and the reflected light from the substrate S is incident on the CCD image sensor via the objective lens. In this way, the upper surface of the substrate S is imaged and a captured image is obtained. The alignment camera 51 is electrically connected to the control unit 9, and obtains a captured image in response to an instruction from the control unit 9, and transmits the captured image to the control unit 9.

[0030] The control unit 9 realizes various processes by controlling the operation of each unit described above. For this purpose, the control unit 9 includes a CPU (Central Processing Unit) 91, a memory (RAM) 92, a storage 93, an input unit 94, a display unit 95, and an interface unit 96. The CPU 91 reads out and executes a control program 931 stored in advance in the storage 93, and executes various operations described below. The memory 92 stores data used for arithmetic processing by the CPU 91 or generated as a result of the arithmetic processing in a short-term manner. The storage 93 stores various data and control programs in a long-term manner. Specifically, the storage 93 is a non-volatile storage device such as a flash memory storage device or a hard disk drive device, and stores, in addition to the control program 931 executed by the CPU 91, for example, CAD (Computer Aided Design) data 932, which is design data representing the contents of a pattern to be drawn.

[0031] The input unit 94 receives operation input from the user, and for this purpose has an appropriate input device (not shown) such as a keyboard, mouse, touch panel, etc. The display unit 95 notifies the user by displaying and outputting various information, and for this purpose has an appropriate display device, for example, a liquid crystal display panel. The interface unit 96 is responsible for communication with an external device. For example, the interface unit 96 functions when the exposure apparatus 1 receives a control program 931 and CAD data 932 from the outside. For this purpose, the interface unit 96 may have a configuration and function for reading data from an external recording medium (for example, a disk drive).

[0032] The CPU 91 executes the control program 931 to realize, in software, functional blocks such as an exposure data generation unit 911, an exposure control unit 912, a focus control unit 913, and a stage control unit 914. Note that each of these functional blocks may be realized, at least in part, by dedicated hardware.

[0033] The exposure data generation unit 911 generates exposure data for modulating the light beam according to the pattern, based on the CAD data 932 read from the storage 93. If the substrate S is deformed, such as distorted, the exposure data generation unit 911 corrects the exposure data according to the amount of distortion of the substrate S, thereby enabling drawing to match the shape of the substrate S. The exposure data is sent to the exposure head 41, which modulates the laser light emitted from the light irradiation unit 40 according to the exposure data. The modulated light beam thus modulated according to the pattern is irradiated onto the substrate S, and the surface of the substrate S is partially exposed to light, thereby drawing the pattern.

[0034] The exposure control unit 912 controls the light irradiation unit 40 to emit a laser light beam having a predetermined power and spot size. The focus control unit 913 controls the projection optical system provided in the exposure head 41 to converge the laser light beam on the surface of the substrate S.

[0035] The stage control unit 914 controls the stage driving mechanism 3 to realize the movement of the stage 2 for alignment adjustment and the movement of the stage 2 for scanning movement during exposure. In the alignment adjustment, the position of the stage 2 is adjusted in the X direction, Y direction, Z direction, and θ direction so that the relative positional relationship between the substrate S placed on the stage 2 and the exposure head 41 at the start of exposure is a predetermined relationship. On the other hand, in the scanning movement during exposure, a main scanning movement in which the stage 2 is moved in the Y direction at a constant speed to pass the substrate S under the exposure head 41 is combined with a step feed (sub-scanning movement) in the X direction at a constant pitch. The position calculation unit 915 calculates the position of the stage 2 based on a signal output by the reading head 82 of the position detection mechanism 8 after reading the linear scale 81.

[0036] Fig. 3 is a view of the main parts of the exposure apparatus as viewed in the Y direction, and Fig. 4 is a perspective view that shows a schematic configuration of the stage driving mechanism 3. Note that Fig. 3 corresponds to a side view of the exposure apparatus 1 as viewed in the (+Y) direction, but in order to particularly clarify the configuration of the stage driving mechanism 3, the illustration of the light irradiation section 40, alignment unit 5, control section 9, etc. is omitted. Also, in these figures and the following figures, the dashed arrows shown near each component of the apparatus indicate the movement direction of that component.

[0037] As shown in Fig. 3(a), a gantry-shaped support frame 101 is attached to a base portion 100 so as to straddle the stage driving mechanism 3 and the stage 2 supported thereby in the X direction. The exposure heads 41 of the exposure unit 4 are attached to this support frame 101. Here, only one exposure head 41 is shown as a representative example, but the number of exposure heads 41 is not limited to this and can be any number. When multiple exposure heads 41 having the same structure are provided, they are disposed at equal intervals in the X direction. They move integrally relative to the substrate S during scanning movement.

[0038] The relative movement between the exposure head 41 and the substrate S is achieved by the stage driving mechanism 3 moving the stage 2. That is, the stage driving mechanism 3 alternately executes main scanning movement, which moves the stage 2 continuously in the Y direction, and sub-scanning movement, which feeds the stage 2 by a predetermined pitch in the X direction, to change the incident position on the substrate S of the exposure beam emitted from the exposure head 41, and ultimately achieves an exposure operation for the entire substrate S.

[0039] The position detection of the stage 2 during these operations is performed by a position detection mechanism 8. Specifically, as shown in Fig. 4, a linear scale 81 extending in the Y direction is attached to the upper surface of the stage 2 near the (+X) end. The linear scale 81 is formed of, for example, a glass plate, and is a two-dimensional linear scale on which scales (gradations) are engraved at predetermined intervals along both the X and Y directions, as will be described later.

[0040] In the following, the term "X-direction scale" refers to a scale with graduations arranged at predetermined intervals along the X direction and used to detect a position in the X direction. Similarly, the term "Y-direction scale" refers to a scale with graduations arranged at predetermined intervals along the Y direction and used to detect a position in the Y direction.

[0041] A read head 82 is provided above the linear scale 81. The read head 82 optically reads the scale of the linear scale 81 and outputs a signal according to the reading result. As described below, the read head 82 is a two-dimensional read head that can individually read the X-direction scale and the Y-direction scale provided on the two-dimensional linear scale 81. An output signal from the read head 82 is input to a position calculation unit 915 of the control unit 9. The position calculation unit 915 counts the signals output from the read head 82 and calculates the position of the stage 2. In addition, it is possible to obtain the moving speed and the moving amount from the change in the position.

[0042] The reading head 82 is attached to the support frame 101 via a linear motion mechanism 83 whose movable direction is the X direction. The linear motion mechanism 83 moves the reading head 82 in the X direction within a predetermined movable range in response to a control command from the control unit 9. As the linear motion mechanism, for example, a linear motor, a ball screw mechanism, a rack and pinion mechanism, etc. can be used.

[0043] The reading head 82 is positioned in the X direction at a position corresponding to the linear scale 81. The Y direction position of the reading head 82 is not changed. Therefore, when the stage 2 moves in the Y direction (main scanning movement), the linear scale 81 passes a position directly below the reading head 82, whereby the reading head 82 sequentially reads the scales provided on the linear scale 81.

[0044] On the other hand, when the stage 2 moves in the X direction (sub-scanning movement), the linear motion mechanism 83 moves the reading head 82 in the X direction in conjunction with the movement. This makes it possible to maintain the reading head 82 facing the linear scale 81 before and after the sub-scanning movement.

[0045] Setting of the movable range of the reading head 82 will be described with reference to Figures 3(b) and 3(c). Figure 3(b) shows the position of the stage 2 when the laser light L emitted from the exposure head 41 is incident on the (+X) side end of the substrate S. Also, Figure 3(c) shows the position of the stage 2 when the laser light L emitted from the exposure head 41 is incident on the (-X) side end of the substrate S.

[0046] In this way, the movement range of the stage 2 in the sub-scanning movement is set so that the exposure beam L is irradiated over the entire area of ​​the substrate S, including both ends in the X direction. Therefore, the movable range of the reading head 82 is also set so that the reading head 82 is disposed opposite the linear scale 81 over the entire movement range of the stage 2. In other words, the movable range is determined so as to include the position directly above the linear scale 81 when the stage 2 is at the position closest to the (-X) direction within its movement range as shown in Fig. 3(b) and the position directly above the linear scale 81 when the stage 2 is at the position closest to the (+X) direction within its movement range as shown in Fig. 3(c).

[0047] In a configuration example in which only one set of exposure heads 41 is provided as in this example, the amount of movement of the stage 2 and the reading head 82 is substantially equal to the length in the X direction of the substrate S. On the other hand, as will be described next, in a configuration example in which multiple sets of exposure heads 41 are arranged in the X direction, each exposure head 41 only needs to expose a partial area of ​​the substrate S, so the amount of movement required of the stage 2 and the reading head 82 is smaller.

[0048] Fig. 5 is a diagram showing a configuration example in which two sets of exposure heads are provided. As shown in Fig. 5(a), for example, when the arrangement pitch P of the two sets of exposure heads 41, 41 is set to half the length Wx of the substrate S in the X direction, each exposure head 41 only needs to expose half of the entire surface of the substrate S in the X direction. Therefore, as shown in Figs. 5(b) and 5(c), the movement amount of the stage 2 and the reading head 82 can be smaller than that in the example shown in Figs. 3(b) and 3(c). The more the number of exposure heads 41 provided, the smaller the movement amount of the stage 2 and the reading head 82.

[0049] In recent years, as the size of the substrate S has increased and the patterns have become finer, the area that can be exposed in one main scanning movement is only a small part of the surface of the substrate S, and even if multiple exposure heads are provided, multiple sub-scanning movements, for example several tens of steps, are required. In the conventional technology described in Patent Document 2, multiple reading heads must be arranged to cover the entire range of such movement. In contrast, in this embodiment, a linear motion mechanism 83 that moves the reading head 82 in the sub-scanning direction is provided, so there is no need to provide multiple reading heads 82.

[0050] Fig. 6 is a diagram for explaining the principle of position detection in the position detection mechanism. As described above, the position detection mechanism 8 of this embodiment detects the position of the stage 2 by combining a two-dimensional linear scale 81 with a reading head 82 that reads it. Specifically, as shown in Fig. 6(a), the reading head 82 has three optical sensors 821, 822, and 823 that optically detect the scales. Meanwhile, the linear scale 81 has an X-direction scale Sx formed at a constant pitch in the X direction, and a Y-direction scale Sy formed at a constant pitch in the Y direction.

[0051] In order to explain the principle, a two-dimensional linear scale having such a simple scale pattern is exemplified here, but various other scale patterns are in practical use as two-dimensional linear scales, and it is possible to appropriately select and use one of these in this embodiment. In addition, the resolution of the scale used is higher than the accuracy required for the stage position control of this apparatus. For example, linear scales having a resolution on the order of nanometers are commercially available, and can be suitably applied to this embodiment.

[0052] Of the three optical sensors, one optical sensor 823 is arranged so as to read the Y-direction scale Sy. Meanwhile, the other two optical sensors 821, 822 are arranged so as to read the X-direction scale Sx, and their positions differ in the Y direction. In the following description, an optical sensor capable of reading the X-direction scale (for example, optical sensors 821, 822 in this example) may be simply referred to as an "X-direction sensor," and an optical sensor capable of reading the Y-direction scale (for example, optical sensor 823 in this example) may be simply referred to as a "Y-direction sensor."

[0053] In addition, in the case where a single optical sensor can read two types of scales that are perpendicular to each other, such as a two-dimensional image sensor, it is possible for the single optical sensor to function both as an "X-direction sensor" and a "Y-direction sensor."

[0054] By combining the reading head 82 and the two-dimensional linear scale 81 thus configured, the position detection mechanism 8 can detect the position of the stage 2 in each of the X and Y directions, and the amount of rotation (yawing) of the stage 2 around the θ axis parallel to the Z axis. Specifically, the position of the stage 2 in the X direction can be detected based on the reading result of at least one of the optical sensors 821 and 822. Also, the position of the stage 2 in the Y direction can be detected based on the reading result of the optical sensor 823. Furthermore, as described below, the amount of yawing of the stage 2 can be obtained by comparing the reading results of the optical sensors 821 and 822. These calculations are executed by the position calculation unit 915 of the control unit 9.

[0055] As shown in Fig. 6(b), consider a state in which the X-direction scale Sx is tilted by an angle θ with respect to the Y direction in which the two X-direction sensors 821, 822 are arranged. Due to this tilt, the X-direction positions of the stage 2 calculated based on the results of the two optical sensors 821, 822 reading the X-direction scale Sx differ from each other. Here, the X-direction positions of the stage 2 calculated from the outputs of the optical sensors 821, 822 are represented by the symbols X1 and X2, respectively. Also, the distance in the Y direction between the two optical sensors 821, 822 is represented by the symbol d.

[0056] Then, from the relationship shown in Figure 6(b), the following calculation formula can be obtained: θ=arctan{(X1-X2) / d} … (Equation 1) In reality, the inclination θ is very small, so the following approximation formula can be used: θ≒(X1-X2) / d… (Formula 2) It is possible to use:

[0057] If the stage 2, which is the object of position detection, and the reading head 82, which is the subject of detection, move in the X direction simultaneously, it becomes impossible to properly detect the amount of movement of the stage 2 relative to the exposure head 41. To solve this problem, the exposure operation in this embodiment is configured as follows.

[0058] 7 is a flow chart showing the processing contents of the exposure operation in this embodiment. This processing is realized by the CPU 91 of the control unit 9 executing a control program 931 stored in the storage 93. Note that this processing is started in a state in which the substrate S to be imaged is placed on the stage 2 in advance and a predetermined alignment adjustment is performed, but since the alignment adjustment technology is well known, a description thereof will be omitted here.

[0059] The stage 2, with the substrate S placed at the correct position, is positioned at a predetermined initial position by the stage driving mechanism 3 (step S101). Then, position detection by the position detection mechanism 8 is started (step S102), and the stage driving mechanism 3 starts main scanning movement by moving the stage 2 in the Y direction (step S103). During the movement of the stage 2, the position detection mechanism 8 detects the stage position at all times, and the operations of the stage driving mechanism 3 and the exposure head 41 are controlled according to the result of the detection.

[0060] When the stage 2 moves to an exposure start position where the incident position of the light beam L emitted from the exposure head 41 reaches one end of the substrate S (step S104), exposure of the substrate S by the exposure head 41 starts (step S105). At that time, correction of the stage position (X direction, θ direction) and control of the exposure head 41 (spatial light modulator 400) (Y direction) are performed as needed based on the detection result of the stage position.

[0061] When the stage 2 moves in the Y direction and reaches an exposure end position where exposure of one stripe is completed (step S106), it is then determined whether exposure of the entire substrate S is completed (step S107). If exposure of the entire surface of the substrate S is completed (YES in step S107), the process ends.

[0062] On the other hand, if there are unexposed areas remaining on the substrate S (NO in step S107), exposure continues. That is, the stage 2 is stepped in the sub-scanning direction at a predetermined pitch (step S108). This shifts the incident position of the exposure beam from the exposure head 41 in the X direction. When the movement of the stage 2 in the sub-scanning direction is completed, the linear motion mechanism 83 then moves the reading head 82 in the X direction according to the amount of movement of the stage 2 (step S109). The reason why the stage 2 and the reading head 82 are moved in two stages at different timings in this manner is as follows.

[0063] FIG. 8 is a diagram showing the movement of the stage 2 and the reading head 82. In FIG. 8, one of the X-direction scales Sx is highlighted to clarify the positional relationship between the sub-figures and to facilitate understanding, but such a distinction is not necessarily made in the actual device. In step S108, as shown by arrow A in FIG. 8, only the stage 2 moves in the X-direction, for example, in the (+X) direction, with the reading head 82 (more precisely, the X-direction sensors 821, 822) fixed. During this time, the X-direction sensors 821, 822 are still operating, so that the amount of movement of the stage 2 in the X-direction can be detected. The amount of movement M1 detected at this time is the amount of movement of the stage 2 relative to the exposure head 41 fixed to the support frame 101, and this is information used to control the exposure operation.

[0064] On the other hand, in step S109, only the read head 82 moves in the (+X) direction while the stage 2 is stopped. However, for convenience of explanation in Fig. 8, the stage 2 is shown as having moved in the (-X) direction relatively to the read head 82 as a reference, as indicated by arrow B. The read head 82 continues to operate during this time, so that the movement amount M2 of the read head 82 relative to the stage 2 can be found.

[0065] In a configuration in which multiple read heads are arranged in advance to accommodate the sub-scanning movement of the stage, the position of each read head is fixed in accordance with the movement pitch, so there is no need to consider positional deviation between the stage. In contrast, in this embodiment, the read head 82 itself moves, so that the relative movement with the stage 2 becomes more complex. As described above, by moving both at different times and detecting the amount of movement between them, it is possible to individually detect the amount of movement between the stage 2 and the exposure head 41 and the amount of movement between the stage 2 and the read head 82.

[0066] This makes it possible to solve the above-mentioned problem of misalignment. Specifically, the difference between the movement amount M1 of the stage 2 detected when the reading head 82 is fixed and the movement amount M2 of the reading head 82 detected when the stage 2 is fixed represents the relative movement amount of the reading head 82 with respect to the stage 2, that is, the amount ΔM of the above-mentioned "misalignment". The stage position detected after the Nth (N is a natural number) sub-scanning movement (e.g., arrow A in FIG. 8) includes the above-mentioned misalignment that occurs during the movement of the reading head 82. For example, the movement amount M3 of the stage 2 obtained from the detection result of the reading head 82 in the (N+1)th sub-scanning movement (e.g., arrow C in FIG. 8) includes the above-mentioned misalignment that occurs during the movement of the reading head 82 performed between the Nth stage movement and the (N+1)th stage movement.

[0067] Therefore, the original movement amount M4 of the stage 2 in the (N+1)th sub-scanning movement can be accurately determined by adding or subtracting the offset amount ΔM corresponding to the magnitude of the positional deviation to the movement amount M3 determined from the detection result of the reading head 82. Since the positional deviation with respect to the stage 2 accumulates each time the reading head 82 moves, for example, when determining the stage position based on the initial position, it is possible to properly determine the stage position by accumulating the positional deviation amount for each movement and correcting the stage movement amount from the initial position using the accumulated value.

[0068] A requirement of the hardware configuration to enable such processing is that the linear scale 81 must be read without moving the read head 82 both before and after one sub-scanning movement of the stage 2. This requirement can be met by appropriately setting the readable range (field of view) of the read head 82, the size of the linear scale 81 in the X direction, and the position of the read head 82 relative to the linear scale 81.

[0069] When the read head 82 moves in the X direction, its position in the Y direction may also fluctuate to some extent. To address this problem, when the read head 82 is moved, it is possible to detect the positional deviation not only in the X direction but also in the Y direction based on the reading result of the Y-direction scale Sy, and use this information to make appropriate corrections. Furthermore, by grasping the positional deviation in each of the X and Y directions, it is also possible to grasp the deviation in the θ axis, that is, the tilt direction, and by using this result, it is possible to similarly correct the tilt amount (yawing amount) of the stage 2.

[0070] As described above, in the exposure apparatus 1 of this embodiment, the position of the stage 2 during main scanning movement and sub-scanning movement is detected by a position detection mechanism 8 that uses the measurement principle of a linear encoder that combines a linear scale 81 and a reading head 82. The linear scale 81 extends in the Y direction, which is the main scanning direction, and can continuously detect the position of the stage 2 during main scanning movement.

[0071] On the other hand, in the X direction which is the sub-scanning direction, the reading head 82 is moved in accordance with the step movement of the stage 2 (linear scale 81), thereby making it possible to read the scale by the reading head 82 at each position in the sub-scanning direction. Therefore, it is no longer necessary to provide multiple reading heads in the sub-scanning direction, and it is possible to suppress the resulting increase in size and cost of the device.

[0072] The linear scale 81 is a two-dimensional scale, and the reading head 82 is equipped with a plurality of optical sensors 821-823 capable of reading the scale in each of the X and Y directions. From these reading results, the position detection mechanism 8 can detect the position of the stage 2 in the X and Y directions and the attitude of the stage 2 in the θ direction (yaw direction).

[0073] The movement of the read head 82 is performed exclusively at a different timing from the movement of the stage 2, that is, so that their movement periods do not overlap in time. In other words, the stage 2 is moved while the read head 82 is stationary, and the amount of movement relative to the read head 82 is detected by the read head 82. The movement of the read head 82 is performed while the stage 2 is stationary, and during this time the amount of movement of the read head 82 relative to the stage 2 is detected by the read head 82. Note that here, the stage 2 is first moved in the sub-scanning direction, and then the read head 82 is moved, but this order may be reversed.

[0074] This makes it possible to avoid problems caused by the movement of the reading head 82, in other words, problems in which the measurement accuracy decreases due to changes in the position of the reading head 82, which is the subject of measurement, and the relative position between the exposure head 41, which is the original measurement target, and the stage 2. From another perspective, even if the positioning accuracy of the reading head 82 by the linear motion mechanism 83 is not so high, any positional deviation caused by this can be detected and corrected, so there is no effect on the measurement accuracy of the position of the stage 2 relative to the exposure head 41. Since a high-precision linear motion mechanism 83 is not required, the resulting increase in costs can be suppressed.

[0075] <Second embodiment> 9 and 10 are diagrams showing a schematic configuration of the main parts of an exposure apparatus 1A as a second embodiment of a drawing apparatus according to the present invention. More specifically, FIG. 9 is a diagram showing the main parts of exposure apparatus 1A of the second embodiment as viewed in the Y direction, and FIG. 10 is a perspective view showing a stage driving mechanism 3 and the surrounding configuration. In the exposure apparatus of this embodiment, the configuration of the position detection mechanism is different from that of the first embodiment, but the other configurations and basic operations are common to those of the first embodiment. Therefore, the same reference numerals are used for the configurations common to the first embodiment, and detailed explanations will be omitted.

[0076] 9(a) and 10, position detection mechanism 8A of exposure apparatus 1A in this embodiment includes two linear scales 851, 852 provided on stage 2, two reading heads 861, 862, a movable member 87 that integrally supports these, and a linear motion mechanism 88 that moves movable member 87 in the X direction. One linear scale 851 is provided near the (-X) side end of stage 2, and the other linear scale 852 is provided near the (+X) side end of stage 2, each extending in the Y direction.

[0077] The two reading heads 861, 862 are attached to the lower part of a movable member 87 extending in the X direction, at different positions in the X direction, and at approximately the same pitch as the arrangement pitch of the linear scales 851, 852 on the stage 2. The linear motion mechanism 88 moves the movable member 87 in the X direction in response to a control command from the control unit 9. As a result, the two reading heads 861, 862 move integrally in the X direction.

[0078] Note that, like the reading head 82 in the first embodiment, two reading heads each supported by an independent linear motion mechanism may be provided. Also in this embodiment, the number of exposure heads 41 is arbitrary, and by arranging a plurality of exposure heads 41, the movement range of the stage 2 in the sub-scanning movement can be reduced. Even in this case, the position detection mechanism 8A only needs to be provided with two sets of linear scales and reading heads corresponding to both ends of the stage 2, regardless of the number of exposure heads 41. As with the above embodiment, the movement range of the stage 2 is reduced, so that the movement range of each reading head can also be reduced.

[0079] The read head 861 reads the scale of the linear scale 851. On the other hand, the read head 862 reads the scale of the linear scale 852. That is, in this embodiment, a linear encoder is provided at each of both ends of the stage 2 in the X direction.

[0080] According to this configuration, position detection is performed by linear encoders at both ends of the stage 2 in the X direction. The principle of position detection and the exposure operation including the processing are basically the same as those in the first embodiment. That is, in this embodiment, too, the exposure operation can be realized by executing the processing shown in FIG.

[0081] In this case, if the Y-direction positions of stage 2 obtained from the reading results at both ends are different from each other, it is considered that stage 2 has a tilt in the θ direction. In other words, when detecting the Y-direction position at both ends of the stage, it is possible to detect the tilt of stage 2 in the θ direction without using the X-direction position detection results.

[0082] Compared to the example of the first embodiment shown in FIG. 6(b), the distance between the two optical sensors that are compared to detect the tilt of the stage 2 in the θ direction can be made sufficiently large, so that the second embodiment may actually be better than the first embodiment in terms of tilt detection accuracy.

[0083] Therefore, if each of the read heads 861, 862 can read the Y-direction scale, it is possible to detect the Y-direction position of the stage 2 and the amount of tilt about the θ-axis. In this sense, at least one of the read heads 861, 862 does not need to have the function of reading the X-direction scale. The corresponding linear scales 851, 852 do not necessarily need to be two-dimensional linear scales, and it is sufficient if a Y-direction scale is provided.

[0084] On the other hand, a two-dimensional linear scale is still useful for the purpose of detecting the X-direction position of the stage 2. For this reason, for example, one of the linear scales 851, 852 can be a one-dimensional scale and the other a two-dimensional scale, and the corresponding linear scale of the read heads 861, 862 can be a one-dimensional scale configured to read only the Y-direction position.

[0085] Furthermore, the read head 82 in the first embodiment is provided with two optical sensors 821, 822 for reading the X-direction scale so as to be able to detect not only the position in the X direction but also the orientation of the stage 2 around the θ axis. However, in this embodiment, since the orientation of the stage 2 can be obtained by comparing the detection results of the Y-direction positions at both ends of the stage 2, only one optical sensor may be used to read the X-direction scale.

[0086] Therefore, the position detection mechanism 8A has the following configuration: (1) A configuration in which linear scales 851 and 852 are both two-dimensional scales; (2) A configuration in which one of the linear scales 851, 852 is a two-dimensional scale and the other is a one-dimensional (Y direction) scale; Both of the above may be true.

[0087] Furthermore, for the two read heads 861 and 862, the linear scales facing each other are two-dimensional scales. (A) A configuration having two X-direction sensors and one Y-direction sensor, as shown in FIG. 6(a); (B) A configuration having one X-direction sensor and one Y-direction sensor; In addition, for a read head in which the opposing linear scale is a one-dimensional scale, it is sufficient to have at least one Y-direction sensor.

[0088] In reality, various configurations can be considered that appropriately combine these, and any of them can accurately detect the X- and Y-direction positions of the stage 2 relative to the exposure head 41 (or an alternative immovable position reference) and the magnitude of the tilt around the θ axis at any time while main scanning movement and sub-scanning movement are being performed.

[0089] Furthermore, in cases where the positioning accuracy of the movement of the read heads 861, 862 in the X direction is sufficiently high and reproducible, for example when a high-precision linear motion mechanism 88 is used, there may be cases where the position deviation caused by the movement of the read heads 861, 862 does not cause a problem. In such cases, the two linear scales 851, 852 may each be a one-dimensional (Y direction) scale, and the read heads 861, 862 may also have only a Y direction sensor. Even with such a configuration, it is possible to detect at least the Y direction position and the θ direction inclination of the stage 2 with the same accuracy as in the above embodiment.

[0090] <Other> As described above, in each of the above embodiments, the exposure apparatus 1, 1A corresponds to one aspect of the "imaging apparatus" of the present invention. The substrate S corresponds to the "substrate" of the present invention, and the stage 2 corresponds to the "stage" of the present invention. The exposure unit 4, and in particular the exposure head 41, functions as the "imaging section" of the present invention. The stage driving mechanism 3 functions as the "first moving mechanism" of the present invention.

[0091] In addition, the linear scales 81, 851, 852 correspond to the "linear scale" of the present invention, the reading heads 82, 861, 862 correspond to the "reading head" of the present invention, and the linear motion mechanisms 83, 88 correspond to the "second moving mechanism" of the present invention, and the position detection mechanisms 8, 8A having these and the position calculation unit 915 function together as the "position detection unit" of the present invention.

[0092] The present invention is not limited to the above-mentioned 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-mentioned embodiment, the linear scale is attached to both ends in the X direction of the flat upper surface of the stage 2. However, the linear scale does not need to be attached directly to the stage as long as it is configured to move integrally with the stage and, more preferably, to prevent the relative positional relationship between them from fluctuating. For example, the stage and the linear scale may be attached to a common base member.

[0093] Also, for example, the read heads 82, 861, 862 in the position detection mechanisms 8, 8A of the above embodiments are attached to a gantry-shaped support frame 101 that straddles the stage 2, and therefore the distance between the read heads and the linear scales 81, 851, 852 is relatively large. However, the arrangement of the read heads is not limited to this, and it is sufficient that the read heads are supported in a position where they can read the linear scales, independent of the movement of the stage 2, and in a state where they do not interfere with said movement.

[0094] Furthermore, the information on the position and attitude of the stage 2 detected by the position detection mechanisms 8, 8A can be used in any way. In the above embodiment, the information is used to control the exposure head 41 and the stage driving mechanism 3, but it can also be used for other purposes, such as detecting anomalies based on the position detection results.

[0095] In the second embodiment, the linear scales are disposed at both ends of the stage 2 in the X direction. However, the two linear scales may be disposed at different positions in the X direction, and may be provided, for example, at two locations on one side of the stage.

[0096] In the above embodiment, the position of the stage 2 in the X and Y directions is detected by reading a linear scale provided at the end of the stage 2 in the X direction, but in the present invention, it is sufficient for the linear scale to be at least capable of "detecting the position of the stage in the main scanning direction using the principle of a linear encoder." Therefore, other means may be used for detecting the position in the X direction. For example, a linear scale extending in the X direction (sub-scanning direction) may be provided on the stage, and the position in the X direction may be detected by reading the linear scale.

[0097] Moreover, the exposure apparatus 1, 1A in the above embodiment is an apparatus that performs pattern drawing by exposing a substrate surface on which a photosensitive layer is formed with a light beam modulated based on drawing data, as a specific example of the "drawing apparatus" according to the present invention. However, the manner of drawing is not limited to this and is arbitrary, and may be, for example, a manner in which drawing is performed by exposure via a photomask, a reticle, or the like, or a manner in which drawing is performed by directly processing the substrate surface with laser light.

[0098] Furthermore, the exposure apparatus 1, 1A in the above embodiment is equipped with a step-and-scan type stage drive mechanism that alternates between continuous stage movement in the main scanning direction and step movement in the sub-scanning direction. However, the present invention can also be applied to a drawing apparatus that uses a step-and-repeat type movement mode, in which drawing is performed sequentially for each predetermined two-dimensional area while changing the position.

[0099] As described above by way of example of specific embodiments, in the position detection unit of the drawing device according to the present invention, for example, the linear scale may be a two-dimensional linear scale having scales in both the main scanning direction and the sub-scanning direction. With this configuration, it is possible to detect the stage position in each of the main scanning direction and the sub-scanning direction independently of each other. Furthermore, with this configuration, the position detection unit can detect the magnitude of yawing of the stage in addition to the stage positions in each of the main scanning direction and the sub-scanning direction based on the reading result of the reading head.

[0100] For example, the position detector may have a plurality of linear scales arranged at different positions in the sub-scanning direction and a plurality of reading heads arranged corresponding to each of the plurality of linear scales. With this configuration, it is possible to detect the inclination of the stage from the positional deviation obtained based on the reading results of each of the plurality of reading heads. In other words, the position detector configured in this manner can detect the magnitude of the yawing of the stage in addition to the position of the stage in the main scanning direction.

[0101] In this case, at least one of the multiple linear scales may be a two-dimensional linear scale having a scale in each of the main scanning direction and the sub-scanning direction. With this configuration, it is possible to detect the stage position in each of the main scanning direction and the sub-scanning direction independently of each other. In this way, it is possible to detect the stage position in each of the main scanning direction and the sub-scanning direction and the magnitude of the yawing of the stage.

[0102] Furthermore, in the drawing device and drawing method according to the present invention, the period during which the stage moves in the sub-scanning direction and the period during which the read head moves may be configured so that they do not overlap with each other, that is, these movements are performed exclusively at different times. With such a configuration, the stage moves while the read head is stationary, and only the amount of movement of the stage can be obtained from the reading result of the linear scale at this time. On the other hand, the amount of movement of the read head relative to the stage can be obtained from the reading result of the linear scale when the read head moves while the stage is stationary. By using this information, it is possible to prevent a decrease in detection accuracy due to the movement of the read head, which is the measurement reference, from occurring. [Industrial Applicability]

[0103] The present invention is suitable for use in technical fields in which drawing is performed on a substrate to form a pattern on a substrate such as a semiconductor substrate, a semiconductor package substrate, a printed wiring board, or a glass substrate. [Explanation of symbols]

[0104] 1,1A Exposure equipment (drawing equipment) 2 Stage 3 Stage drive mechanism (first moving mechanism) 8,8A Position detection mechanism (position detection part) 41 Exposure head (drawing section) 81,851,852 Linear scale 82,861,862 Read Head 83, 88 Linear motion mechanism (second moving mechanism) 821,822 X-direction sensor 823 Y-direction sensor 915 Position calculation unit (position detection unit) S-substrate Sx X-direction scale Sy Y-axis scale X sub-scanning direction Y Main scanning direction

Claims

1. a stage on whose upper surface a substrate can be placed; a drawing unit that draws on the substrate placed on the stage by irradiating the substrate with light; a first movement mechanism that moves the stage relatively to the imaging unit to perform a main scanning movement in a main scanning direction parallel to the upper surface and a sub-scanning movement in a sub-scanning direction parallel to the upper surface and intersecting the main scanning direction; a position detection unit that detects the relative position between the drawing unit and the stage in the main scanning direction; Equipped with The position detection unit a linear scale provided integrally with the stage and having a scale formed along the main scanning direction; a read head for reading the scale; a second movement mechanism that moves the reading head in the sub-scanning direction relative to the drawing unit; and When the stage is moved in the sub-scanning direction by the first moving mechanism, the second moving mechanism moves the reading head by an amount corresponding to an amount of movement of the stage.

2. 2. The drawing device according to claim 1, wherein the linear scale is a two-dimensional linear scale provided with a scale in each of the main scanning direction and the sub-scanning direction.

3. The imaging device according to claim 2 , wherein the position detection unit detects the position of the stage in each of the main scanning direction and the sub-scanning direction and the magnitude of yawing of the stage based on the reading result of the reading head.

4. 2. The drawing device according to claim 1, wherein the position detection unit includes a plurality of the linear scales provided at different positions in the sub-scanning direction, and a plurality of the reading heads provided corresponding to each of the plurality of linear scales.

5. 5. The imaging device according to claim 4, wherein the position detection unit detects the position of the stage in the main scanning direction and the magnitude of yawing of the stage based on the reading results of each of the plurality of reading heads.

6. 5. The drawing device according to claim 4, wherein at least one of the plurality of linear scales is a two-dimensional linear scale provided with a scale in each of the main scanning direction and the sub-scanning direction.

7. The imaging device according to claim 6 , wherein the position detection unit detects the position of the stage in each of the main scanning direction and the sub-scanning direction and the magnitude of yawing of the stage based on the reading results of the plurality of reading heads.

8. 8. The imaging device according to claim 1, wherein a period during which the stage is moved in the sub-scanning direction by the first moving mechanism and a period during which the reading head is moved by the second moving mechanism do not overlap each other.

9. A drawing method for drawing by irradiating light from a drawing unit onto a substrate while moving a stage on which a substrate is placed, and alternately performing a main scanning movement in a main scanning direction parallel to the upper surface and a sub-scanning movement in a sub-scanning direction parallel to the upper surface and intersecting the main scanning direction, the method comprising: a read head reading a linear scale that is integrally provided with the stage and has a scale formed along the main scanning direction, thereby detecting a relative position between the imaging unit and the stage in the main scanning direction; When the stage moves in the sub-scanning direction, the reading head is moved by an amount corresponding to the amount of movement of the stage.

10. 10. The imaging method according to claim 9, wherein a period during which the stage moves in the sub-scanning direction and a period during which the reading head moves do not overlap each other.

Images