JP2018081238A - Scanning exposure equipment and control method thereof and article production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology advantageous for improving transfer accuracy of a pattern on a substrate.SOLUTION: A scanning exposure equipment 100 includes a measurement part 21 for measuring a relative position of an original plate stage 12 and an original plate 11; and a controller 22 for controlling drive of the original plate stage 12 and a substrate stage 15. Before scanning exposure of a substrate 14, an original plate stage 15 is driven on trial, and an amount of change of a relative position of the original plate stage 12 and the original plate 11 due to the drive on trial is detected by using the measurement part 22. The controller 22 controls a drive of the original plate stage 12 and the substrate stage 15 in the scanning exposure based on the amount of change of the relative position. The drive on trial includes an acceleration drive that increases speed of the original plate stage 12 and deceleration drive for reducing the speed. A maximum value of an absolute value of acceleration of the original plate stage 12 in the deceleration drive is smaller than a maximum value of an absolute value of acceleration of the original plate stage 12 in the acceleration movement.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scanning exposure apparatus, a control method thereof, and an article manufacturing method.

  A scanning exposure apparatus is known as an apparatus for forming a pattern on a substrate. In the scanning exposure apparatus, the pattern of the original is transferred onto the substrate by scanning and exposing the substrate using slit light while scanning the original and the substrate. In the scanning exposure apparatus, since the original is mounted on the original stage and driven at high speed, it is difficult to directly measure the position of the original during scanning exposure. Therefore, it is common to measure the position of the original stage on which the original is mounted. For this reason, it is necessary to determine how the original is placed on the original stage by measurement, and to correct the position of the original stage or the substrate stage (see Patent Document 1).

  However, in recent years, due to a demand for throughput improvement, the original stage is driven at a large acceleration in scanning exposure, and therefore, a force exceeding the frictional force for holding the original is generated along with acceleration and deceleration. Misalignment may occur between them. For this reason, there is a technique for improving transfer accuracy by measuring the amount of deviation after performing acceleration / deceleration driving in advance and performing correction during scanning exposure based on the measurement result (see Patent Document 2).

JP 2000-003855 A Japanese Unexamined Patent Publication No. 2015-231035

In a scanning exposure apparatus, in general, measurement of deviation of an original with respect to an original stage is performed in a stationary state. For this reason, when the original stage is driven before measuring the deviation amount, the last force applied to the original becomes a force due to deceleration. However, in scanning exposure, scanning exposure is performed after a force by acceleration is applied to the original. For the above reasons, conventionally, it has been difficult to accurately determine the shift during scanning exposure, and thus the pattern transfer accuracy to the substrate has been poor.
An object of the present invention is to provide a technique advantageous for improving the transfer accuracy of a pattern onto a substrate.

  One aspect of the present invention relates to an original stage holding an original and a scanning exposure apparatus that scans and exposes the substrate while scanning the substrate stage holding the substrate. The scanning exposure apparatus includes the original stage, the original, And a control unit for controlling the driving of the original stage and the substrate stage, the original stage is test-driven before scanning exposure of the substrate, and the test driving causes the A change amount of the relative position between the original stage and the original plate is detected using the measurement unit, and the control unit detects the original stage and the substrate stage in the scanning exposure of the substrate based on the change amount of the relative position. The test drive includes an acceleration drive for driving the original stage so as to increase a speed of the original stage, and the original scan. Decelerating drive for driving the original stage so as to reduce the speed of the page, and the maximum absolute value of the acceleration of the original stage in the deceleration drive is the absolute value of the acceleration of the original stage in the acceleration drive. Less than the maximum value.

  According to the present invention, a technique advantageous for improving the transfer accuracy of a pattern to a substrate is provided.

The figure which shows the structure of the scanning exposure apparatus of one Embodiment of this invention. The top view which shows the original plate, the mark provided in the original plate, the original plate stage, and the mark provided in the original plate stage. The figure which illustrates the drive profile of the original stage for scanning exposure. The figure which illustrates the drive profile of the original stage in a comparative example. The figure which illustrates the drive profile of the original stage in one embodiment of the present invention. The figure which shows the control method of the scanning exposure apparatus of one Embodiment of this invention.

  Hereinafter, the present invention will be described through exemplary embodiments thereof with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member thru | or element, and the overlapping description is abbreviate | omitted.

  A scanning exposure apparatus 100 according to an embodiment of the present invention will be described with reference to FIG. The scanning exposure apparatus 100 is a step-and-scan type exposure apparatus that scans and exposes a substrate 14 with slit light shaped by a slit. The scanning exposure apparatus 100 includes an illumination optical system 10, an original stage 12, an original stage drive unit 23, a projection optical system 13, a substrate stage 15, a substrate stage drive unit 24, an original stage position measurement unit 17, a substrate stage position measurement unit 18, A relative position measurement unit 21 and a control unit 22 are included.

  The control unit 22 includes an illumination optical system 10, an original stage 12, an original stage drive unit 23, a projection optical system 13, a substrate stage 15, a substrate stage drive unit 24, an original stage position measurement unit 17, a substrate stage position measurement unit 18, The position measuring unit 21 is controlled. The control unit 22 controls a process for transferring the pattern formed on the original 11 to the substrate 14 (a process for scanning and exposing the substrate 14). The control unit 22 is, for example, PLD (abbreviation of Programmable Logic Device) such as FPGA (abbreviation of Field Programmable Gate Array), or ASIC (abbreviation of Application Specific Integrated Circuit) or an ASIC (abbreviation of Generalized Integrated Circuit). It can be constituted by a computer or a combination of all or part of them.

  The original stage position measuring unit 17 measures the position of the original stage 12. The relative position measurement unit (measurement unit) 21 measures the relative position between the original 11 and the original stage 12. The relative position between the original 11 and the original stage 12 measured by the relative position measurement unit 21 is used to correct the target position of either the original stage 12 or the substrate stage 15 during scanning exposure.

  The illumination optical system 10 illuminates the original 11. The illumination optical system 10 shapes light emitted from a light source (not shown) by a light shielding member such as a mask king blade into slit light having, for example, a strip shape or an arc shape long in the X direction. A part of the original 11 is illuminated. The original plate 11 and the substrate 14 are respectively held by the original plate stage 12 and the substrate stage 15, and are respectively disposed at optically conjugate positions (object plane and image plane of the projection optical system 13) via the projection optical system 13. Is done.

  The projection optical system 13 has a predetermined projection magnification (for example, 1/2 times or 1/4 times), and projects the pattern of the original 11 on the substrate 14 with slit light. A region on the substrate 14 on which the pattern of the original 11 is projected (a region irradiated with slit light) can be referred to as an irradiation region. The original stage 12 and the substrate stage 15 are configured to be movable in a direction (Y direction) orthogonal to the optical axis direction (Z direction) of the projection optical system 13. The original stage 12 is driven by an original stage drive unit 23, and the substrate stage 15 is driven by a substrate stage drive unit 24. The original stage 12 and the substrate stage 15 are relatively scanned by the original stage drive unit 23 and the substrate stage drive unit 24 at a speed ratio corresponding to the projection magnification of the projection optical system 13 while being synchronized with each other. As a result, the substrate 14 is scanned in the Y direction with respect to the irradiation region, and the pattern formed on the original 11 is transferred to the shot region on the substrate 14. Then, such scanning exposure is sequentially performed for each of the plurality of shot areas of the substrate 14 while moving the substrate stage 15, thereby completing the exposure processing on one substrate 14.

  The original stage position measuring unit 17 includes a laser interferometer, for example, and measures the position of the original stage 12. The laser interferometer, for example, irradiates laser light toward a reflecting plate (not shown) provided on the original stage 12, and causes interference between the laser light reflected by the reflecting plate and the laser light reflected by the reference surface. The displacement of the original stage 12 (displacement from the reference position) is detected. The original stage position measuring unit 17 can acquire the current position of the original stage 12 based on the displacement. Here, the original stage position measurement unit 17 measures the position of the original stage 12 with a laser interferometer using laser light, but is not limited thereto, and for example, measures the position of the original stage 12 with an encoder. May be.

  The relative position measurement unit 21 includes, for example, an image sensor, and can detect the mark 11a provided on the original 11 and the mark 12a provided on the original stage 12 simultaneously or individually. As a result, the relative position between the original 11 and the original stage 12 is measured. Here, although the mark is detected by the image sensor in the relative position measurement unit 21 of the present embodiment, the mark is not limited to this. For example, the mark may be detected by a transmissive sensor.

  FIG. 2 is a plan view showing the original 11, the mark 11 a provided on the original, the original stage 12, and the mark 12 a provided on the original stage 12. The marks 11a and 12a are shown overlapping in FIG. For example, the relative position measurement unit 21 detects the degree of overlap between the mark 11 a provided on the original 11 and the mark 12 a provided on the original stage 12, and obtains the relative position of the original 11 with respect to the original stage 12.

  The scanning exposure apparatus 100 is required to accurately transfer the pattern of the original 11 to the target position of the substrate 14. For this purpose, it is important to accurately control the relative position of the original 11 with respect to the substrate 14 on the substrate stage 15 during scanning exposure. Therefore, in the scanning exposure apparatus 100, the relative position measuring unit 21 measures the relative position of the original 11 with respect to the original stage 12 in advance. However, during the scanning exposure, the original stage 12 is accelerated, so that a force is applied to the original 11 and the relative position of the original 11 with respect to the original stage 12 may be different from the stationary state. For this reason, the position of the original 11 during scanning exposure obtained based on the position of the original stage 12 measured by the original stage position measuring unit 17 and the relative position measured in advance may have an error. This may make it difficult to accurately transfer the pattern of the original 11 to the substrate 14. Therefore, the relative position measurement unit 21 can measure the relative position between the original stage 12 and the original 11 after reproducing the relative position shift between the original stage 12 and the original 11 by accelerating the original stage 12. .

  Hereinafter, the driving of the original stage 12 (hereinafter referred to as test driving) performed for measuring the relative position between the original stage 12 and the original 11 will be described with reference to FIGS. 3, 4, and 5. The relative position measurement and test drive between the original stage 12 and the original 11 are controlled by the control unit 22 and are performed before the scanning exposure of the substrate 14. The control unit 22 controls the driving of the original stage 12 and the substrate stage 15 in the scanning exposure of the substrate 14 based on the change amount of the relative position between the original stage 12 and the original plate 11.

  3, 4, and 5, the horizontal axis represents time, and the vertical axis represents the acceleration profile of the original stage 12 and the velocity profile of the original stage 12. The acceleration profile of the original stage 12 indicates a temporal change in the target acceleration of the original stage 12 for controlling the driving of the original stage 12 by the original stage driving unit 23. The speed profile of the original stage 12 indicates a temporal change in the target speed of the original stage 12 for controlling the driving of the original stage 12 by the original stage driving unit 23.

  FIG. 3 illustrates a driving profile of the original stage 12 for scanning exposure. As shown in FIG. 3, the scanning period 600 for driving the original stage 12 for scanning exposure of the substrate can include an acceleration driving period 601, a constant speed driving period 602, and a deceleration driving period 603. The acceleration drive period 601 is a period during which the original stage 12 is driven so as to increase the speed of the original stage 12 (a period during which the original stage 12 is accelerated at a positive acceleration in the scanning direction). The constant speed drive period 602 is a period during which the original stage 12 is driven at a constant speed (ie, acceleration 0). In the deceleration driving period 603, after the acceleration driving period 601 and the constant speed driving period 602, the period in which the original stage 12 is driven so as to decrease the speed of the original stage 12 (the original stage 12 is accelerated in the scanning direction with negative acceleration. Period). Normally, the substrate 14 is scanned and exposed during all or part of the constant speed driving period 602. For example, scanning exposure is started in the middle of the acceleration driving period 601 and scanning exposure is ended in the middle of the deceleration driving period 603. May be.

  In the acceleration driving period 601, the original stage 12 is accelerated to the scanning speed Vs in the constant speed driving period 602, and in the deceleration driving period 603, the original stage 12 is decelerated from the scanning speed Vs in the constant speed driving period 602 to the speed 0. A force (inertial force) corresponding to the acceleration indicated in the acceleration profile is applied to the original 11, and thereby the relative position between the original stage 12 and the original 11 can be changed.

  FIG. 4 shows a driving profile of the original stage 12 in the comparative example. In one comparative example shown in FIG. 4, the test drive (test drive period) 610 can include an acceleration drive (acceleration drive period) 611 and a deceleration drive (deceleration drive period) 612. Relative position measurement 613 by the relative position measurement unit 21 can be performed before the test drive (test drive period) 610, and relative position measurement 614 by the relative position measurement unit 21 can be performed after the test drive 610. Although not shown in FIG. 4, between the relative position measurement 613 and the test drive 610, the original from the position where the relative position measurement unit 21 performs the relative position measurement 613 to the position where the test drive 610 is started. Movement of the stage 12 can be included. Further, the movement of the original stage 12 from the position where the test drive 610 is completed to the position where the relative position measurement unit 213 performs the relative position measurement 613 can be included between the test drive 610 and the relative position measurement 614. .

  The relative position measurements 613 and 614 are measurements of the relative positions of the mark 11a on the original 11 and the mark 12a on the original stage 12. Hereinafter, the relative position means a relative position between the mark 11a of the original 11 and the mark 12a of the original stage 12. The control unit 22 can detect the difference between the relative position obtained by the relative position measurement 613 and the relative position obtained by the relative position measurement 614 as a change amount of the relative position generated by the test drive 610. The drive profile in the deceleration drive 612 of the test drive 610 can be the same as the drive profile in the acceleration drive period 601 in the scanning period 600.

  In this case, it should be noted that when the relative position is changed by − | ΔRP | by the acceleration drive 611 and the relative position is changed by + | ΔRP | by the deceleration drive 612, the change in the relative position caused by the test drive 610 is performed. The amount is detected as 0. When the change amount of the relative position generated by the test drive 610 is detected as 0, + | ΔRP | is not reflected in the correction for driving the original stage 12 (and the substrate stage 15). Accordingly, the deviation of the pattern actually transferred from the substrate 14 from the target position is a value obtained by multiplying + | ΔRP | by the projection magnification of the projection optical system 13. Further, when the relative position is changed by − | ΔRP1 | by the acceleration drive 611 and the relative position is changed by + | ΔRP2 | by the deceleration drive 612, the amount of change in the relative position by the acceleration drive period 601 in the scanning period 600 is correctly set. It cannot be detected.

  FIG. 5 shows a driving profile of the original stage 12 in one embodiment of the present invention. In the embodiment shown in FIG. 5, the test drive (test drive period) 620 can include an acceleration drive (acceleration drive period) 621 and a deceleration drive (deceleration drive period) 622. Relative position measurement 623 by the relative position measurement unit 21 can be performed before the test drive (test drive period) 620, and relative position measurement 624 by the relative position measurement unit 21 can be performed after the test drive 620. The relative position measurements 623 and 624 are measurements of the relative positions of the mark 11a on the original 11 and the mark 12a on the original stage 12. The control unit 22 can detect the difference between the relative position obtained by the relative position measurement 623 and the relative position obtained by the relative position measurement 624 as a change amount of the relative position generated by the test drive 620. The drive profile in the acceleration drive 621 of the test drive 620 can be the same as the drive profile in the acceleration drive period 601 in the scanning period 600. In one example, the maximum acceleration of the original stage 12 in the acceleration drive 621 of the test drive 620 is Amax, and the maximum acceleration of the original stage 12 in the acceleration drive period 601 of the scanning period 600 is the same as Amax.

  The absolute value | −Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is smaller than the maximum absolute value | −Amax | of the original stage 12 in the acceleration drive 621 of the test drive 620.

  The maximum absolute value | −Amax ′ | of the acceleration of the original stage 12 in the deceleration drive 622 of the test drive 620 is the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 in the scanning period 600 | −Amax. Less than | The maximum absolute value | -Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is, for example, the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 of the scanning period 600 | It may be 70% or less of −Amax |. Alternatively, the maximum absolute value | -Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is, for example, the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 of the scanning period 600. It may be 50% or less of the value | −Amax |. Alternatively, the maximum absolute value | -Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is, for example, the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 of the scanning period 600. It may be 30% or less of the value | −Amax |. Alternatively, the maximum absolute value | -Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is, for example, the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 of the scanning period 600. It may be 20% or less of the value | −Amax |. Alternatively, the maximum absolute value | -Amax ′ | of the original stage 12 in the deceleration drive 622 of the test drive 620 is, for example, the maximum absolute value of the acceleration of the original stage 12 in the deceleration drive period 603 of the scanning period 600. It may be 10% or less of the value | -Amax |.

  According to the present embodiment, the change in the relative position in the deceleration drive period 603 can be suppressed to 0 or an allowable level or less. Therefore, a change in relative position due to the acceleration drive period 601 can be accurately detected. As described above, the control unit 22 detects the difference between the relative position obtained by the relative position measurement 623 and the relative position obtained by the relative position measurement 624 as a change amount of the relative position caused by the test drive 620. be able to. Then, the control unit 22 determines the target positions of the original stage 12 and the substrate stage 15 in the scanning period 600 based on the relative position change caused by the test drive 620, and determines the original stage 12 and the original stage 12 based on the target position. The substrate stage 15 is controlled. Here, if the difference is Δe, the control unit 22 may correct the target position of the original stage 12 based on Δe. Alternatively, the control unit 22 may correct the target position of the substrate stage 15 based on a value obtained by multiplying Δe by the magnification of the projection optical system 13. Alternatively, the target positions of both the original stage 12 and the substrate stage 15 may be corrected so that the pattern is transferred to the target position of the substrate 14 based on Δe.

  In one example, when the original stage 12 is driven according to the drive profile shown in FIG. 3, the position of the original 11 has changed by 10 nm from the original position (position before acceleration) in the acceleration drive period 601. This amount of change was obtained by evaluating the position of the pattern transferred to the substrate 14. Further, when the test drive 610 was performed according to the drive profile of the comparative example shown in FIG. 4, the change amount of the relative position was detected as 8 nm. The error in this case is 2 nm. Further, when the test drive 620 was performed according to the drive profile of the present embodiment shown in FIG. 5, the change amount of the relative position was detected as 9 nm. The error in this case is 1 nm, indicating that the result is better than the comparative example.

  FIG. 6 shows a method for controlling the scanning exposure apparatus 100. This control method is controlled by the control unit 22. In step S <b> 710, the control unit 22 measures the relative position between the original stage 12 and the original 11 using the relative position measurement unit 21. In step S720, the control unit 22 performs test driving of the original stage 12 according to the driving profile illustrated in FIG. In step S730, the control unit 22 uses the relative position measurement unit 21 to measure the relative position between the original stage 12 and the original plate 11. In step S740, the control unit 22 detects the amount of change in the relative position by obtaining a difference between the relative position obtained in step S710 and the relative position obtained in step S7310. In step S750, the control unit 22 corrects at least one target position of the original stage 12 and the substrate stage 15 based on the amount of change in the relative position detected in step S74. In step S760, a plurality of shot areas of the substrate 14 are scanned and exposed while controlling the original stage 12 and the substrate stage 15 based on the target position corrected in step S750.

  Hereinafter, the article manufacturing method will be described. An article manufacturing method according to an embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. In the method for manufacturing an article according to the present embodiment, a latent image pattern is formed on the photosensitive agent applied to the substrate using the above-described scanning exposure apparatus (a step of exposing the substrate), and the latent image pattern is formed in this step. Developing the processed substrate. Further, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

100: Scanning exposure apparatus, 12: Original stage, 15: Substrate stage, 21: Relative position measurement unit

Claims (10)

A scanning exposure apparatus that scans and exposes the substrate while scanning an original stage holding the original plate and a substrate stage holding the substrate,
A measuring unit for measuring a relative position between the original stage and the original,
A control unit for controlling the driving of the original stage and the substrate stage,
Prior to scanning exposure of the substrate, the original stage is test-driven, and the amount of change in the relative position between the original stage and the original by the test drive is detected using the measurement unit,
The control unit controls driving of the original stage and the substrate stage in scanning exposure of the substrate based on the amount of change in the relative position,
The test drive includes an acceleration drive that drives the original stage so as to increase the speed of the original stage, and a deceleration drive that drives the original stage so as to reduce the speed of the original stage,
The maximum absolute value of acceleration of the original stage in the deceleration drive is smaller than the maximum absolute value of acceleration of the original stage in the acceleration drive;
A scanning exposure apparatus. The maximum acceleration of the original stage in the acceleration drive in the acceleration drive period for driving the original stage so as to increase the speed of the original stage in the scanning period for driving the original stage for scanning exposure of the substrate. Equal to the maximum acceleration of the original stage,
The scanning exposure apparatus according to claim 1, wherein: The driving profile of the original stage in the acceleration drive is an acceleration driving period for driving the original stage so as to increase the speed of the original stage in a scanning period for driving the original stage for scanning exposure of the substrate. Equal to the driving profile of the original stage,
The scanning exposure apparatus according to claim 1, wherein: The original stage is driven such that the maximum absolute value of the acceleration of the original stage in the deceleration drive reduces the speed of the original stage during the scanning period for driving the original stage for scanning exposure of the substrate. Smaller than the maximum absolute value of the acceleration of the original stage during the deceleration drive period,
The scanning exposure apparatus according to any one of claims 1 to 3, wherein The original stage is driven such that the maximum absolute value of the acceleration of the original stage in the deceleration drive reduces the speed of the original stage during the scanning period for driving the original stage for scanning exposure of the substrate. 70% or less of the absolute value of the acceleration of the original stage during the deceleration driving period
5. A scanning exposure apparatus according to claim 4, wherein: The original stage is driven such that the maximum absolute value of the acceleration of the original stage in the deceleration drive reduces the speed of the original stage during the scanning period for driving the original stage for scanning exposure of the substrate. 50% or less of the absolute value of the acceleration of the original stage during the deceleration drive period
5. A scanning exposure apparatus according to claim 4, wherein: The measuring unit measures the amount of change in the relative position by detecting a relative position between the mark provided on the original stage and the mark provided on the original plate before and after the test drive;
The scanning exposure apparatus according to claim 1, wherein The controller corrects at least one target position of the original stage and the substrate stage in the scanning exposure of the substrate based on the change amount of the relative position.
The scanning exposure apparatus according to claim 1, wherein A method of controlling a scanning exposure apparatus that scans and exposes a substrate while scanning an original stage holding an original and a substrate stage holding a substrate,
Prior to the scanning exposure of the substrate, a test drive of the original stage is performed, and a change in relative position between the original stage and the original plate due to the test drive is detected,
Based on the amount of change in the relative position, the substrate is scanned and exposed while controlling the driving of the original stage and the substrate stage for scanning exposure of the substrate,
The test drive includes an acceleration drive for driving the original stage so as to increase the speed of the original stage, and a deceleration drive for driving the original stage so as to decrease the speed of the original stage after the acceleration drive. Including
The absolute value of the acceleration of the original stage in the deceleration drive is smaller than the absolute value of the acceleration of the original stage in the acceleration drive;
A control method for a scanning exposure apparatus. An article manufacturing method comprising:
Exposing the substrate using the scanning exposure apparatus according to any one of claims 1 to 8,
Developing the substrate exposed in the step;
An article manufacturing method comprising:

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