Exposure device and method for manufacturing article

Abstract

The present invention relates to an exposure device and a method for manufacturing an article. To provide an exposure device capable of correcting the measurement results of the position of a stage in consideration of stage movement, thereby improving exposure performance, the exposure device includes: a first stage having a first reflecting surface that moves back and forth at a predetermined frequency while holding one of a substrate and an original; a first measuring unit that measures the position of the first stage by receiving first measurement light reflected by the first reflecting surface; a second stage having a second reflecting surface that holds the other of the substrate and the original; a second measuring unit that measures the position of the second stage by receiving second measurement light reflected by the second reflecting surface; a third measuring unit that is located closer to the second stage than the first stage and measures the wavelength of the third measurement light transmitted therethrough; and a control unit that corrects the measurement results of the second measuring unit based on the measurement results of the third measuring unit and the predetermined frequency.

Description

Technical Field

[0001] The present invention relates to an exposure device and a method for manufacturing an article. Background Art

[0002] In an exposure apparatus, it is necessary to improve exposure performance by measuring the position of a stage with high precision.

[0003] Furthermore, when measuring the position of the stage using an interferometer, it is necessary to pay attention to changes in the wavelength of the measurement light emitted toward the stage.

[0004] Specifically, when the temperature, humidity, or air pressure of the space where the measurement light propagates changes, the refractive index of the space changes accordingly, and thus the wavelength of the measurement light changes, causing errors when measuring the position of the stage using the interferometer.

[0005] Japanese Patent Gazette No. 2008-145203 discloses an exposure device that corrects the wavelength of measurement light from an interferometer based on the difference between the optical path from an air vibration source to the interferometer and the distance between the wavelength detectors, thereby correcting the change in the measurement value of the interferometer associated with the influence of sound waves from the air vibration source.

[0006] In addition, in an exposure device that moves the stage back and forth when exposing a substrate, the environment of the space in which the measurement light emitted from the interferometer for measuring the position of the stage is transmitted, especially the air pressure, changes with time, so the refractive index of the space and thus the wavelength of the measurement light changes with time.

[0007] On the other hand, the exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 2008-145203 corrects the wavelength of the measuring light based on the distance of the optical path from the air vibration source to the interferometer, without considering the temporal change in the wavelength of the measuring light accompanying the movement of the stage. Summary of the Invention

[0008] Therefore, an object of the present invention is to provide an exposure apparatus capable of correcting a measurement result of a position of a stage in consideration of movement of the stage, thereby improving exposure performance.

[0009] An exposure apparatus according to the present invention exposes a substrate in such a manner that a pattern formed on a plate is transferred to the substrate, and is characterized by comprising: a first stage having a first reflecting surface perpendicular to a first direction and reciprocating in the first direction at a predetermined frequency while holding one of the substrate and the plate; a first measuring unit for measuring the position of the first stage in the first direction by emitting first measuring light toward the first reflecting surface and then receiving the first measuring light reflected by the first reflecting surface; a second stage having a second reflecting surface perpendicular to the first direction and holding the other of the substrate and the plate; a second measuring unit for measuring the position of the second stage in the first direction by emitting second measuring light toward the second reflecting surface and then receiving the second measuring light reflected by the second reflecting surface; a third measuring unit disposed closer to the second stage than the first stage and measuring the wavelength of the third measuring light transmitted therethrough; and a control unit for correcting the measurement result of the second measuring unit based on the measurement result of the third measuring unit and the predetermined frequency.

[0010] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A It is a partially enlarged schematic cross-sectional view of the exposure apparatus according to the first embodiment.

[0012] Figure 1B It is a partially enlarged schematic cross-sectional view of the exposure apparatus according to the first embodiment.

[0013] Figure 2A It is a diagram schematically showing temporal changes in the wavelength of measurement light in the exposure apparatus according to the first embodiment.

[0014] Figure 2B It is a diagram schematically showing temporal changes in the wavelength of measurement light in the exposure apparatus according to the first embodiment.

[0015] Figure 3 This is a flowchart showing a process of acquiring a component in a predetermined frequency region included in a temporal change in the wavelength of measurement light in the exposure apparatus according to the first embodiment.

[0016] Figure 4 It is a partially enlarged schematic plan view of the exposure apparatus according to the second embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, the exposure apparatus according to the present embodiment will be described in detail with reference to the accompanying drawings. In addition, in the drawings shown below, in order to facilitate understanding of the present embodiment, the drawings are drawn with a scale different from the actual scale.

[0018] In the following, a direction perpendicular to the substrate placement surface of the substrate placement table is defined as a z direction, and two directions perpendicular to each other within the substrate placement surface are defined as an x direction and a y direction.

[0019] [First embodiment]

[0020] Improving the positioning accuracy of a mounting table provided in an exposure apparatus is extremely important because it directly affects exposure performance.

[0021] Furthermore, in order to improve the positioning accuracy of the stage, it is necessary to improve the measurement accuracy of a unit for measuring the position of the stage, such as an interferometer.

[0022] Furthermore, when the wavelength of the measurement light changes due to changes in the environment of the space in which the measurement light propagates, errors occur in the measurement results of the interferometer.

[0023] Furthermore, conventionally, as a means for correcting such errors, a wavelength tracker has been used that can detect the amount of change in the wavelength of the measurement light accompanying changes in the environment of the predetermined space by comparing the wavelengths of reference light transmitted in a vacuum space and measurement light transmitted in the predetermined space.

[0024] Generally, a wavelength tracker is large in size and therefore cannot be arranged near the optical path through which the measuring light from the interferometer propagates.

[0025] In addition, the exposure apparatus is provided with a substrate stage that moves while holding a substrate and an original plate stage that moves while holding an original plate.

[0026] Therefore, when attempting to install a wavelength tracker on each mounting stage, the cost, workload, and size increase.

[0027] Therefore, an object of the present embodiment is to provide an exposure apparatus capable of improving the positioning accuracy of a stage by correcting a measurement error of the position of the stage with high accuracy while suppressing increases in cost, workload, and size.

[0028] Specifically, according to this embodiment, changes in the environment of the space where measurement light propagates for measuring the position of the original plate stage are estimated using measurement results based on a wavelength tracker arranged near the space where the substrate stage is installed as described below.

[0029] Furthermore, by estimating the amount of change in the wavelength of the measurement light and correcting the measurement result of the position of the original plate stage based on the estimated amount of change in the wavelength, the positioning accuracy of the stage can be improved.

[0030] More specifically, a length measurement system using an interferometer is used to measure the positions of stages such as a substrate stage and a reticle stage provided in an exposure apparatus.

[0031] A length measurement system using an interferometer measures position based on the wavelength of the measuring light.

[0032] Therefore, when measuring the position of the mounting stage, if the refractive index of the gas in the space, i.e., air, changes in accordance with changes in the environment of the space where the measurement light is transmitted, i.e., temperature, humidity, or air pressure, the wavelength of the transmitted measurement light changes.

[0033] In this case, an error occurs in the measurement result of the position of the stage, and thus the positioning accuracy of the stage decreases.

[0034] Therefore, in a length measurement system using an interferometer provided in an exposure apparatus, it is necessary to correct the measured value according to changes in the wavelength of the measurement light.

[0035] As a method for correcting the wavelength of the measurement light in the interferometer, there is the following method: detecting the environment of the measurement light transmission path, that is, the temperature, humidity, and air pressure, and calculating the change in the refractive index in the measurement light transmission path based on the detected results.

[0036] As an example of such a method, there is a method of calculating the refractive index in a predetermined space by measuring the position of the same measurement object using reference light propagating in a vacuum space and measurement light propagating in a predetermined space and comparing the two measured values.

[0037] Such a correction method is used in a device called a wavelength tracker or a wavelength compensator, which is provided by manufacturers of length measurement systems using interferometers.

[0038] Here, the wavelength of the measuring light transmitted in the predetermined space is λ, and the wavelength of the reference light transmitted in the vacuum space is λ. v , when the refractive index of a predetermined space is set to n, the following formula (1) is satisfied.

[0039] λ=λ v / n···(1)

[0040] That is, the wavelength tracker can measure the refractive index n in a predetermined space, and by knowing the refractive index n in the predetermined space, can calculate the wavelength λ of the measurement light.

[0041] Furthermore, as described above, an interferometer is a sensor for measuring position based on the wavelength and phase of measurement light. Therefore, when the wavelength of the measurement light changes, an error occurs in the position measurement result.

[0042] Therefore, if the wavelength of the measurement light can be accurately calculated, errors in the measurement results based on the position of the interferometer can be corrected.

[0043] Figure 1A and Figure 1B A partially enlarged schematic cross-sectional view of the exposure apparatus 100 according to the first embodiment is shown.

[0044] like Figure 1A and Figure 1B As shown, the exposure apparatus 100 according to the present embodiment includes a substrate stage 1 (first stage), an original plate stage 11 (second stage), and a projection optical system 13 .

[0045] Furthermore, in the exposure apparatus 100 according to the present embodiment, exposure can be performed so as to transfer a pattern formed on an unillustrated original plate to an unillustrated substrate using exposure light from an unillustrated light source.

[0046] Here, the projection optical system 13 held by the holding portion 15 guides the exposed light having passed through the original plate (not shown) onto the substrate (not shown).

[0047] In the exposure apparatus 100 according to the present embodiment, the positions of the substrate stage 1 and the original plate stage 11 are measured by a length measurement system using an interferometer as described below.

[0048] The substrate stage 1 can hold a substrate such as a wafer (not shown) and can perform scanning movement in at least the y direction (first direction) and step movement in the x direction.

[0049] In addition, a reflector 2 (first reflecting surface) for measuring the position of the substrate stage 1 in the y direction is arranged on the substrate stage 1, and the measurement light 30 (length measurement beam, first measuring light) for position measurement is transmitted between the interferometer 3 (first measuring part, first interferometer) and the reflector 2.

[0050] That is, the interferometer 3 emits the measuring light 30 toward the reflecting mirror 2 and then receives the measuring light 30 reflected by the reflecting mirror 2 .

[0051] Then, the distance between the interferometer 3 and the reflecting mirror 2 is measured based on the interference between the measuring light 30 reflected by the reflecting mirror 2 and reference light (first reference light) (not shown).

[0052] Next, interference light 4 obtained by causing the measurement light 30 reflected by the reflection mirror 2 and reference light (not shown) to interfere with each other is emitted from the interferometer 3 to the optical pickup 5 .

[0053] Then, after receiving the interference light 4 , the optical pickup 5 outputs the interference light 4 to the signal processing board 8 via the optical fiber 6 .

[0054] Then, the signal processing board 8 performs photoelectric conversion on the input interference light 4 to calculate the position of the substrate stage 1 in the y direction.

[0055] Furthermore, measurement light output from the wavelength tracker 9 (third measurement unit) for detecting the refractive index of space is input to the signal processing board 8 via the optical fiber 37 .

[0056] As described above, the wavelength tracker 9 calculates the refractive index in the predetermined space by measuring the position of the same measurement object using the measurement light (the fourth measurement light) transmitted in the vacuum space and the measurement light (the third measurement light) transmitted in the predetermined space and comparing the measurement values of both.

[0057] In other words, the wavelength tracker 9 is arranged closer to the substrate stage 1 than the reticule stage 11 and can calculate the refractive index of the space in which the substrate stage 1 is installed by measuring the wavelength of the measurement light propagating therein.

[0058] Then, the signal processing board 8 transmits the measured value of the refractive index of the space where the substrate stage 1 is installed, obtained by the wavelength tracker 9 , to the wavelength correction unit 20 (control section) via the cable 21 .

[0059] Thereafter, the wavelength correction unit 20 calculates in real time the amount of change in the wavelength of the measurement light 30 propagating in the space where the substrate stage 1 is installed, based on the value of the refractive index transmitted from the signal processing board 8 .

[0060] Then, the wavelength correction unit 20 corrects the measurement result of the position of the substrate stage 1 in the y direction using the calculated amount of change in the wavelength of the measurement light 30 .

[0061] In the exposure apparatus 100 according to the present embodiment, the position in the y direction of the original plate stage 11 that is scanning-moved in the y direction while holding an original plate (not shown) is also measured using the same method as described above.

[0062] That is, Figure 1A and Figure 1B As shown, measurement light 31 for position measurement (length measurement beam, second measurement light) is transmitted between the reflection mirror 12 (second reflection surface) provided on the original plate stage 11 and the interferometer 33 (second measurement unit, second interferometer).

[0063] In other words, the interferometer 33 measures the position of the original plate stage 11 in the y direction by emitting the measurement light 31 toward the reflection mirror 12 and then receiving the measurement light 31 reflected by the reflection mirror 12 .

[0064] Then, interference light 34 obtained by causing the measurement light 31 reflected by the reflection mirror 12 and reference light (second reference light) (not shown) to interfere with each other is emitted from the interferometer 33 to the optical pickup 35 .

[0065] Next, the optical pickup 35 receives the interference light 34 and outputs the interference light 34 to the signal processing board 8 via the optical fiber 36 .

[0066] Then, the signal processing board 8 performs photoelectric conversion on the input interference light 34 to calculate the position of the original plate mounting table 11 in the y direction.

[0067] Next, a method of correcting the measurement result of the position of the original plate mounting table 11 in the y direction in the exposure apparatus 100 according to the present embodiment will be described.

[0068] In the exposure apparatus, providing wavelength trackers in the space where the reticle stage 11 is arranged and in the space where the substrate stage 1 is arranged is not preferable because it increases the size of the apparatus.

[0069] Therefore, in the conventional exposure apparatus, it is assumed that the environments of the spaces where the original plate mounting table 11 and the substrate mounting table 1 are respectively arranged, that is, the temperature, humidity, and air pressure are the same.

[0070] Then, based on this, the measurement result of the position of the original plate stage 11 is corrected using the value of the refractive index calculated by the wavelength tracker 9 installed in the space where the substrate stage 1 is arranged.

[0071] However, when performing exposure using a scanning exposure device, generally, the substrate stage 1 and the original plate stage 11 are moved in a scanning manner in directions opposite to each other.

[0072] That is, Figure 1B As shown, for example, when the substrate stage 1 performs scanning movement in the +y direction, the original plate stage 11 performs scanning movement in the -y direction.

[0073] In other words, the original plate stage 11 reciprocates in the y direction at the same frequency f as that of the substrate stage 1 so as to move in one direction in the y direction when the substrate stage moves in the other direction.

[0074] Furthermore, the air pressure in the predetermined space changes in accordance with the wind pressure generated by the movement of the mounting table installed in the space.

[0075] Therefore, the air pressure in the space where the substrate stage 1 is located changes as the substrate stage 1 scans and moves in the +y direction. Meanwhile, the air pressure in the space where the original plate stage 11 is located changes as the original plate stage 11 scans and moves in the -y direction.

[0076] Specifically, when the substrate stage 1 is scanned in the +y direction, the air in the space where the measurement light 30 for measuring the position of the substrate stage 1 in the y direction propagates expands, so the air pressure in the space decreases.

[0077] On the other hand, when the original stage 11 scans in the -y direction in synchronization with the scanning movement of the substrate stage in the +y direction, the air in the space where the measurement light 31 for measuring the position of the original stage 11 in the y direction is transmitted is compressed, so the air pressure in the space increases.

[0078] Furthermore, in order to perform exposure on each of a plurality of shot regions formed on a substrate (not shown), the substrate stage 1 periodically repeats scanning movement in the +y direction and scanning movement in the −y direction.

[0079] On the other hand, the original plate stage 11 repeats scanning movement in the −y direction and scanning movement in the +y direction in a phase opposite to that of the substrate stage 1 .

[0080] Therefore, the air pressure in the space where the measurement light 31 propagates and the air pressure in the space where the measurement light 30 propagates periodically change with time so as to be in opposite phases to each other.

[0081] Furthermore, generally, the reticle stage 11 is scanned and moved at a higher speed than the substrate stage 1 , so the amplitude of the temporal change in the air pressure in the space where the reticle stage 11 is located is different from the amplitude of the temporal change in the air pressure in the space where the substrate stage 1 is located.

[0082] In the exposure apparatus 100 according to this embodiment, the above-mentioned features are utilized to correct the measurement result of the position of the original plate stage 11 in the y direction as follows using the refractive index value calculated by the wavelength tracker 9 installed in the space where the substrate stage 1 is arranged.

[0083] Figure 2A The wavelength λ of the measurement light measured by the wavelength tracker 9 when exposing a predetermined substrate in the exposure apparatus 100 according to the present embodiment is schematically shown. w time changes.

[0084] In addition, the wavelength λ of the measurement light measured by the wavelength tracker 9 is w The temporal variation of is equivalent to the temporal variation of the refractive index of the space accompanied by the change of the environment of the space where the wavelength tracker 9 is installed, that is, the change of the temperature, humidity or air pressure.

[0085] Furthermore, the wavelength tracker 9 is provided in the space where the substrate stage 1 is arranged, that is, the space where the measuring light 30 propagates. Figure 2A The wavelength λ shown wThe temporal variation of can be regarded as the temporal variation of the wavelength of the measurement light 30 .

[0086] When the temperature of the space within the exposure apparatus is precisely controlled as in the exposure apparatus 100 according to the present embodiment, the change in the refractive index of the space is dominated by the change in the gas pressure of the space.

[0087] Furthermore, the time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 during the scanning movement of the substrate stage 1 is w (t) can be expressed as the following formula (2).

[0088] λ w (t) = λ w low (t)+λ w high (t)···(2)

[0089] Here, λ w low (t) is the component based on the time variation of atmospheric pressure, λ w high (t) is a component based on the temporal change in wind pressure generated when the substrate stage 1 is scanningly moved.

[0090] Here, it is considered that w high (t) changes with time according to a plurality of scanning movements of the substrate stage 1 that are performed back and forth at a predetermined frequency when exposing a plurality of shot regions on the substrate.

[0091] That is, for example, when the frequency of the scanning movement of the substrate stage 1 is f [Hz], λ w high (t) also varies with frequency f[Hz].

[0092] At this time λ w high (t) is represented by the following formula (3).

[0093]

[0094] That is, as the substrate stage 1 performs multiple scanning movements between time t0 and time t1, λ w high (t) can be represented by a sine function with amplitude M and frequency f that changes with time.

[0095] On the other hand, atmospheric pressure varies with time at a very low frequency, so it is assumed that w low (t) changes with time at a frequency sufficiently lower than the frequency f of the scanning movement of the substrate stage 1 .

[0096] Based on the above, it can be considered that the wavelength λ of the measurement light measured by the wavelength tracker 9 is w like Figure 2A Changes over time as shown.

[0097] Furthermore, the time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 is w The component λ in (t) that changes due to the scanning movement of the substrate stage 1 w high (t) period T s When the scanning movement frequency f is 5 Hz, it becomes T s =1 / f=0.2 seconds.

[0098] Furthermore, as described above, the substrate stage 1 and the original plate stage 11 are scan-moved in directions opposite to each other.

[0099] Therefore, the temporal change in the air pressure in the space where the measurement light 31 propagates and the temporal change in the air pressure in the space where the measurement light 30 propagates are in opposite phases to each other.

[0100] Therefore, when the wavelength tracker is set in the space where the original plate mounting table 11 is configured, it is considered that the time change of the wavelength of the measurement light measured by the wavelength tracker, that is, the time change of the wavelength of the measurement light 31 is in reverse phase with respect to the time change of the wavelength of the measurement light 30.

[0101] Furthermore, since the scanning movement speeds of the original plate stage 11 and the scanning movement speeds of the substrate stage 1 are different from each other, it is considered that the amplitude of the temporal change in the wavelength of the measurement light 31 and the amplitude of the temporal change in the wavelength of the measurement light 30 are also different from each other.

[0102] Considering the above, the time variation λ of the wavelength of the measurement light 31 is r (t) can be expressed as the following formula (4).

[0103] λ r (t) = λ r low (t)+λ r high (t)···(4)

[0104] Here, λ r high (t) Yes

[0105]

[0106] a is a coefficient (predetermined coefficient) associated with the ratio of the maximum speed during the scanning movement of the original plate stage 11 to the maximum speed during the scanning movement of the substrate stage 1 .

[0107] On the other hand, since the temporal change in atmospheric pressure is considered to be equal in the space where the original plate mounting table 11 is arranged and the space where the substrate mounting table 1 is arranged, it can be considered that the following formula (5) is satisfied.

[0108] λ r low (t) = λ w low (t)···(5)

[0109] According to the above, the time variation λ of the wavelength of the measurement light 31 r (t) can be rewritten as the following formula (6).

[0110] λ r (t) = λ w low (t)-aλ w high (t)···(6)

[0111] Figure 2B The time variation λ of the wavelength of the measurement light 31 obtained by the above-described method in the exposure apparatus 100 according to the present embodiment is shown. r (t).

[0112] As described above, the wavelengths of the measurement light 30 from the interferometer 3 and the measurement light in the wavelength tracker 9 change in accordance with the movement of the substrate stage 1. On the other hand, the wavelength of the measurement light 31 from the interferometer 33 changes in accordance with the movement of the original stage 11.

[0113] Then, based on the value measured by the wavelength tracker 9 installed in the space where the substrate stage 1 is arranged, the time change of the air pressure in the space where the measurement light 31 from the interferometer 33 for measuring the position of the original stage 11 in the y direction is estimated.

[0114] Then, the temporal change in the wavelength of the measurement light 31 is estimated, and the measurement result of the position of the original plate stage 11 in the y direction obtained by the interferometer 33 is corrected.

[0115] This eliminates the need to provide a wavelength tracker in the space where the reticle stage 11 is disposed, and allows for improved accuracy in measuring the position of the reticle stage 11 in the y direction using the interferometer 33 .

[0116] Next, the time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 is described. w (t) will w low (t) and λ w high (t) Methods of separation from each other.

[0117] Figure 3 The time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 in the exposure apparatus 100 according to the present embodiment is shown. w (t) will w low (t) and λ w high (t) Flowchart of mutually separate processes.

[0118] First, in order to obtain the time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 w (t) The noise component is removed, and the output from the wavelength tracker 9 is input to a first low-pass filter (not shown) (step S1).

[0119] At this time, the noise component that changes with time at a frequency sufficiently higher than the frequency f of the scanning movement of the substrate stage 1 needs to be removed. On the other hand, the component λ that changes with time according to the frequency f needs to be removed. w high (t) needs to be extracted correctly.

[0120] Therefore, the cutoff frequency of the first low-pass filter is set to a value greater than the frequency f of the scanning movement of the substrate stage 1 .

[0121] That is, the time change λ of the wavelength of the measurement light 30 for measuring the position of the substrate stage 1 in the y direction w (t) can be expressed as the following formula (7).

[0122] λ w (t) = λ w lpf_high (t)···(7)

[0123] Furthermore, the frequency f of the scanning movement of the substrate stage 1 depends on the speed and stroke of the scanning movement of the substrate stage 1 , and therefore the cutoff frequency of the first low-pass filter can be changed in accordance with these.

[0124] In other words, the cutoff frequency of the first low-pass filter, that is, the predetermined frequency range selected by the first low-pass filter, is determined by the frequency f of the scanning movement of the substrate mounting stage 1 .

[0125] Then, the output value of the first low-pass filter at this time is expressed as λ w lpf_high (t).

[0126] Next, as mentioned above w low (t) is a component that changes with time at a frequency sufficiently lower than the frequency f of the scanning movement of the substrate stage 1 .

[0127] Therefore, in order to obtain the time variation λ of the wavelength of the measurement light measured by the wavelength tracker 9 w (t) Extract λ w low (t) The output from the wavelength tracker 9 is input to a second low-pass filter having a cutoff frequency sufficiently lower than the frequency f (step S2). Here, the cutoff frequency sufficiently lower than the frequency f is, for example, 0.1 Hz.

[0128] Then, let the output value of the second low-pass filter at this time be represented by λ w lpf_low (t).

[0129] According to the above, λ w low (t) can be compared with the output value λ of the second low-pass filter w lpf_low (t) is represented by the following formula (8).

[0130] λ w low (t) = λ w lpf_low (t)···(8)

[0131] In addition, λ w high (t) can be compared with the output values λ of the first low-pass filter and the second low-pass filter. w lpf_high (t) and λ w lpf_low (t) is represented by the following formula (9).

[0132] λ w high (t) = λ w lpf_high (t)-λ w lpf_low (t)···(9)

[0133] Thus, according to equations (8) and (9), we can get w lpf_high (t) and λ w lpf_low (t) Get λ w low (t) and λ w high (t)(Step S3).

[0134] Then, the time variation λ of the wavelength of the light 31 is measured. r(t) can be expressed as the following formula (10) by substituting formula (8) and formula (9) into formula (6).

[0135] λ r (t) = λ w lpf_low (t)-a(λ w lpf_high (t)-λ w lpf_low (t))···(10)

[0136] Here, the value of coefficient a included in equation (10) is determined by the ratio between the maximum speeds of the original plate stage 11 and the substrate stage 1 during scanning movement, but is not limited thereto and may be determined to a predetermined value for improving overlay accuracy.

[0137] As described above, in the exposure apparatus 100 according to this embodiment, the position of the substrate stage 1 in the y direction is measured by the interferometer 3 (first measurement step), and the position of the original plate stage 11 in the y direction is measured by the interferometer 33 (second measurement step).

[0138] Then, by using the wavelength tracker 9 to measure the wavelength of the measuring light (the third measurement step) and inputting the time change of the wavelength of the measuring light measured by the wavelength tracker 9 into the low-pass filter, the component of the predetermined frequency region in the time change of the wavelength of the measuring light is obtained.

[0139] Specifically, the temporal variation in the wavelength of the measurement light measured by wavelength tracker 9 is input to a first low-pass filter having a first cutoff frequency higher than the frequency f of the scanning movement, and a second low-pass filter having a second cutoff frequency lower than the frequency f. Thus, components in the first frequency region and components in the second frequency region are obtained from the temporal variation in the wavelength of the measurement light measured by wavelength tracker 9.

[0140] That is, in the exposure apparatus 100 according to the present embodiment, the measured value λ of the wavelength tracker 9 is w (t) Extract the components λ of the predetermined frequency region respectively w lpf_high (t) and λ w lpf_low (t). In addition, the difference between them is multiplied by the gain a.

[0141] Then, the time variation λ of the wavelength of the measurement light 31 of the interferometer 33 for measuring the position of the reticle stage 11 in the y direction is calculated. r (t) The result is used to correct the measured value of the position of the original plate mounting table 11 in the y direction (correction step).

[0142] That is, in the exposure device 100 involved in this embodiment, the wavelength correction unit 20 corrects the measurement result of the position of the original stage 11 in the y direction based on the interferometer 33 according to the measurement result of the wavelength tracker 9 and the frequency f in the scanning movement of the substrate stage 1.

[0143] This makes it possible to calibrate the measurement value of the interferometer 33 for measuring the position of the original plate stage 11 in the y direction with high accuracy.

[0144] In the exposure apparatus 100 according to the present embodiment, the measured value λ of the wavelength tracker 9 is obtained using a low-pass filter. w (t) Extract the components λ of the predetermined frequency region respectively w lpf_high (t) and λ w lpf_low (t), but not limited thereto.

[0145] For example, a moving average filter, a bandpass filter, or a high-pass filter may be used to filter the measured value λ of the wavelength tracker 9. w (t) Extracting components in a predetermined frequency region.

[0146] [Second embodiment]

[0147] Figure 4 A partially enlarged schematic plan view of an exposure apparatus 200 according to a second embodiment is shown.

[0148] like Figure 4 As shown, in the exposure apparatus 200 according to the present embodiment, the reflecting mirror 2 (first reflecting surface) for measuring the position of the substrate stage 1 in the y direction (first direction) is arranged on the substrate stage 1 .

[0149] Then, the measuring light 30 for position measurement (length measurement beam, first measuring light) is transmitted between the interferometer 3 (first measuring unit, first interferometer) and the reflecting mirror 2 .

[0150] That is, the interferometer 3 measures the position of the substrate stage 1 in the y direction by outputting the measurement light 30 toward the reflection mirror 2 and then receiving the measurement light 30 reflected by the reflection mirror 2 .

[0151] Next, interference light 4 obtained by causing the measuring light 30 and reference light (first reference light) (not shown) to interfere with each other is emitted from the interferometer 3 to the optical pickup 5 .

[0152] Then, after receiving the interference light 4 , the optical pickup 5 outputs the interference light 4 to the signal processing board 8 via the optical fiber 6 .

[0153] Then, the signal processing board 8 performs photoelectric conversion on the input interference light 4 to calculate the position of the substrate stage 1 in the y direction.

[0154] Furthermore, measurement light output from the wavelength tracker 9 for detecting the refractive index of a predetermined space is input to the signal processing board 8 via the optical fiber 37 .

[0155] Then, the signal processing board 8 transmits the measured value of the refractive index in the predetermined space obtained by the wavelength tracker 9 to the wavelength correction unit 20 via the cable 21 .

[0156] Thereafter, the wavelength correction unit 20 calculates the amount of change in the wavelength of the measurement light 30 propagating in a predetermined space in real time based on the value of the refractive index transmitted from the signal processing substrate 8 .

[0157] Then, the wavelength correction unit 20 corrects the measurement result of the position of the substrate stage 1 in the y direction using the calculated amount of change in the wavelength of the measurement light 30 .

[0158] At this time, the time variation λ of the wavelength of the measurement light 30 measured by the wavelength tracker 9 is y (t) can be expressed as in the following formula (11) similarly to the exposure apparatus 100 according to the first embodiment.

[0159] λ y (t) = λ y low (t)+λ y high (t)···(11)

[0160] Here, λ y high (t) is represented by the following formula (12).

[0161]

[0162] That is, as the substrate stage 1 performs multiple scanning movements between time t t0 and time t1, λ y high (t) can be represented by a sine function whose amplitude M and frequency f vary with time.

[0163] Moreover, λ y low (t) is a component based on the temporal change of the atmospheric pressure, and is considered to change with time at a frequency sufficiently lower than the frequency f of the scanning movement of the substrate stage 1 .

[0164] Furthermore, in the exposure apparatus 200 according to the present embodiment, the reflecting mirror 12 (second reflecting surface) for measuring the position of the substrate stage 1 in the x direction (second direction) is also arranged on the substrate stage 1 .

[0165] Then, the measurement light 31 for position measurement (length measurement beam, second measurement light) is transmitted between the interferometer 33 (second measurement unit, second interferometer) and the reflecting mirror 12 .

[0166] That is, the interferometer 33 measures the position of the substrate stage 1 in the x direction by emitting the measurement light 31 toward the reflection mirror 12 and then receiving the measurement light 31 reflected by the reflection mirror 12 .

[0167] Next, interference light 34 obtained by causing the measuring light 31 and reference light (second reference light) (not shown) to interfere with each other is emitted from the interferometer 33 to the optical pickup 35 .

[0168] Then, after receiving the interference light 34 , the optical pickup 35 outputs the interference light 34 to the signal processing board 8 via the optical fiber 36 .

[0169] Furthermore, wavelength tracker 9 (third measurement unit) is arranged closer to reflector 2 than reflector 12 and can calculate the refractive index of the space in which measurement light 30 from interferometer 3 propagates by measuring the wavelength of measurement light (third measurement light) propagating therein.

[0170] In conventional exposure apparatuses, the measurement result of the interferometer 33 is corrected using, for example, the refractive index value calculated by the wavelength tracker 9 installed in the space where the interferometer 3 is arranged, as it is.

[0171] However, in the scanning exposure apparatus such as the exposure apparatus 200 according to the present embodiment, the substrate stage 1 performs scanning movement in the y direction and, on the other hand, performs stepping movement in the x direction.

[0172] That is, in the substrate mounting table 1 , the step movement in the x direction and the scan movement in the y direction are not linked to each other but are performed independently.

[0173] Furthermore, in the substrate stage 1 , the speed and acceleration during the step movement in the x direction and the speed and acceleration during the scan movement in the y direction are also different from each other.

[0174] Therefore, fluctuations in the air pressure in the space where the measuring light 30 propagates during scanning movement in the y direction and fluctuations in the air pressure in the space where the measuring light 31 propagates during stepping movement in the x direction also differ from each other.

[0175] That is, when the time variation of the wavelength of the measurement light measured by the wavelength tracker 9 installed in the space where the interferometer 3 is arranged is directly applied to the measurement light 31 from the interferometer 33 for correction, the measurement error increases depending on the position in the x direction.

[0176] On the other hand, it can be considered that the temporal changes in the atmospheric pressure are equal to each other in the space where the measuring light 30 propagates and the space where the measuring light 31 propagates.

[0177] Therefore, in the exposure device 200 according to the present embodiment, the temporal change λ of the wavelength of the measurement light 31 is expressed as in the following equation (13): x (t), and use the relationship shown in the following formula (14).

[0178] λ x (t) = λ x low (t)···(13)

[0179] λ x low (t) = λ y low (t)···(14)

[0180] Then, a low-pass filter having a cutoff frequency lower than the frequency f is used to measure the time variation λ of the wavelength of the light 30. y (t) Extract λ y lpf_low (t), and according to

[0181] λ y low (t) = λ y lpf_low (t)

[0182] The relationship between λ and formula (14) is as follows: y lpf_low (t) is used as λ x low (t).

[0183] As described above, in exposure apparatus 200 according to this embodiment, the temporal variation in the wavelength of the measurement light measured by wavelength tracker 9 is input to a low-pass filter having a cutoff frequency lower than frequency f. This allows the acquisition of a component in a predetermined frequency region from the temporal variation in the wavelength of the measurement light measured by wavelength tracker 9.

[0184] That is, in the exposure apparatus 200 according to the present embodiment, the measured value λ of the wavelength tracker 9 is y (t) Extract the component λ associated with the change in atmospheric pressure y low (t).

[0185] Then, the time change λ of the wavelength of the measurement light 31 from the interferometer 33 for measuring the position of the substrate stage 1 in the x direction is calculated. x (t) The result is used to correct the measured value of the position of the substrate stage 1 in the x direction.

[0186] That is, in the exposure device 200 involved in this embodiment, the wavelength correction unit 20 corrects the measurement result of the position of the substrate stage 1 in the x direction based on the interferometer 33 according to the measurement result of the wavelength tracker 9 and the frequency f of the scanning movement of the substrate stage 1 in the y direction.

[0187] This makes it possible to calibrate the measured value of the position of the substrate stage 1 in the x direction with high accuracy.

[0188] Furthermore, the temporal change in the wavelength of the measurement light of the wavelength tracker 9 may also include a component corresponding to a change in the air pressure of the space in which the measurement light 31 propagates during the step movement in the x-direction.

[0189] In this case, the measured value of the position of the substrate stage 1 in the x direction based on the interferometer 33 can also be corrected by inputting the output from the wavelength tracker 9 into a bandpass filter corresponding to the frequency of the step movement and extracting the component associated with the step movement in the x direction.

[0190] Furthermore, in the exposure apparatus 200 according to this embodiment, the measurement result of the position of the substrate stage 1 in the x direction is corrected based on the measurement result of the wavelength tracker 9 and the frequency f of the scanning movement of the substrate stage 1 in the y direction.

[0191] However, the present invention is not limited thereto, and the measurement result of the position of the substrate stage 1 in the z direction may be corrected based on the measurement result of the wavelength tracker 9 and the frequency f of the scanning movement of the substrate stage 1 in the y direction.

[0192] According to the present invention, it is possible to provide an exposure apparatus capable of correcting the measurement result of the position of the stage in consideration of the movement of the stage, thereby improving exposure performance.

[0193] [Production method]

[0194] Next, a method for manufacturing an article using the exposure apparatus according to this embodiment will be described.

[0195] The method for manufacturing articles such as semiconductor IC elements, liquid crystal display elements, and MEMS includes a step of exposing a substrate such as a wafer or a glass substrate coated with a photosensitizer using the exposure apparatus according to this embodiment.

[0196] Furthermore, the above method includes a step of developing the exposed substrate (photosensitive agent) and other known steps of processing the developed substrate.

[0197] In addition, other well-known processes referred to herein include etching, photosensitive agent stripping, cutting, bonding, and packaging.

[0198] According to the method for manufacturing an article according to this embodiment, it is possible to manufacture an article of higher quality than before.

[0199] As mentioned above, although the preferred embodiment was described, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist of the invention.

[0200] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An exposure device for exposing a substrate in such a manner that a pattern formed on an original plate is transferred to the substrate, characterized in that: have: a first mounting table having a first reflecting surface perpendicular to a first direction and configured to reciprocate in the first direction at a predetermined frequency while holding one of the substrate and the original; a first measuring unit configured to measure the position of the first stage in the first direction by emitting first measuring light toward the first reflecting surface and then receiving the first measuring light reflected by the first reflecting surface; a second mounting table having a second reflecting surface perpendicular to the first direction and configured to hold the other of the substrate and the original; a second measuring unit configured to measure the position of the second stage in the first direction by emitting second measuring light toward the second reflecting surface and then receiving the second measuring light reflected by the second reflecting surface; a third measuring unit arranged closer to the first mounting stage than the second mounting stage, and configured to measure a wavelength of third measurement light transmitted therethrough; as well as The control unit corrects the measurement result of the second measurement unit based on the measurement result of the third measurement unit and the predetermined frequency.

2. The exposure device according to claim 1, wherein The second mounting table reciprocates in the first direction at the predetermined frequency so as to move in one direction of the first direction when the first mounting table moves in the other direction.

3. The exposure device according to claim 2, wherein The wavelengths of the first measurement light and the third measurement light change in accordance with the movement of the first stage, and the wavelength of the second measurement light changes in accordance with the movement of the second stage.

4. The exposure device according to claim 2, wherein The control unit obtains a component in a predetermined frequency region from the temporal variation in the wavelength of the third measurement light measured by the third measurement unit by inputting the temporal variation in the wavelength of the third measurement light to at least one of a low-pass filter, a band-pass filter, and a high-pass filter.

5. The exposure device according to claim 4, wherein The first stage and the second stage each perform a plurality of scanning movements in a reciprocating manner in the first direction at the predetermined frequency when exposing the substrate. The predetermined frequency region is determined according to the predetermined frequency.

6. The exposure device according to claim 5, wherein have: a first low-pass filter having a first cutoff frequency higher than the predetermined frequency; and a second low-pass filter having a second cutoff frequency lower than the predetermined frequency, The control unit obtains a component in a first frequency region and a component in a second frequency region from the temporal variation of the wavelength of the third measurement light measured by the third measurement unit by inputting the temporal variation of the wavelength of the third measurement light into the first low-pass filter and the second low-pass filter, respectively.

7. The exposure device according to claim 6, wherein When the component in the first frequency region is set to λ w lpf_high (t), let the component of the second frequency region be λ w lpf_low (t), let a be the predetermined coefficient, and let λ be the temporal change in the wavelength of the second measurement light. r (t), The control unit corrects the measurement result of the second measuring unit by correcting the wavelength of the second measuring light so as to satisfy the following equation: l r (t)=λ w lpf_low (t)-a(λ w lpf_high (t)-λ w lpf_low (t)).

8. The exposure device according to claim 7, wherein The value of a is determined based on the ratio of the maximum speed of the second stage during the scanning movement to the maximum speed of the first stage during the scanning movement.

9. The exposure device according to claim 7, wherein When the temporal change of the wavelength of the first measuring light is λ w (t), The control unit corrects the measurement result of the first measuring unit by correcting the wavelength of the first measuring light so as to satisfy the following equation: l w (t)=λ w lpf_high (t)。 10. The exposure device according to claim 1, wherein The first measuring unit is a first interferometer that measures the distance between the first measuring unit and the first reflecting surface based on interference between the first measuring light reflected by the first reflecting surface and the first reference light. The second measuring unit is a second interferometer that measures the distance between the second measuring unit and the second reflecting surface based on interference between the second measurement light reflected by the second reflecting surface and the second reference light.

11. The exposure device according to claim 1, wherein The third measurement unit is a wavelength tracker that measures the wavelength of the third measurement light by comparing a measurement result of a predetermined object based on the third measurement light propagated in a predetermined space with a measurement result of the predetermined object based on the fourth measurement light propagated in a vacuum space.

12. An exposure device for exposing a substrate in such a manner that a pattern formed on an original plate is transferred to the substrate, characterized in that: have: a substrate mounting table having a first reflecting surface perpendicular to a first direction and a second reflecting surface perpendicular to a second direction perpendicular to the first direction, and moving back and forth in the first direction at a predetermined frequency while holding the substrate; a first measuring unit configured to measure the position of the substrate stage in the first direction by emitting first measurement light toward the first reflecting surface and then receiving the first measurement light reflected by the first reflecting surface; a second measuring unit configured to measure the position of the substrate stage in the second direction by emitting second measurement light toward the second reflecting surface and then receiving the second measurement light reflected by the second reflecting surface; a third measuring unit arranged closer to the first reflecting surface than the second reflecting surface and configured to measure a wavelength of third measurement light propagating therein; as well as The control unit corrects the measurement result of the second measurement unit based on the measurement result of the third measurement unit and the predetermined frequency.

13. The exposure device according to claim 12, wherein The substrate stage performs a plurality of scanning movements in a reciprocating manner at the predetermined frequency in the first direction when exposing the substrate, and performs a plurality of stepping movements in the second direction.

14. The exposure device according to claim 13, wherein The wavelengths of the first measurement light and the third measurement light change in accordance with the scanning movement of the substrate stage.

15. The exposure device according to claim 12, wherein The control unit obtains a component in a predetermined frequency region from the temporal variation in the wavelength of the third measurement light measured by the third measurement unit by inputting the temporal variation in the wavelength of the third measurement light to at least one of a low-pass filter, a band-pass filter, and a high-pass filter.

16. The exposure device according to claim 15, wherein The predetermined frequency region is a frequency region lower than the predetermined frequency.

17. The exposure device according to claim 15, wherein A low-pass filter having a cut-off frequency lower than the predetermined frequency is provided, The control unit obtains the component in the predetermined frequency region by inputting the temporal change in the wavelength of the third measurement light measured by the third measurement unit to the low-pass filter.

18. The exposure device according to claim 17, wherein When the component in the predetermined frequency region is set to λ y lpf_low (t), let the temporal change of the wavelength of the second measuring light be λ x (t), The control unit corrects the measurement result of the second measuring unit by correcting the wavelength of the second measuring light so as to satisfy the following equation: l x (t)=λ y lpf_low (t)。 19. A method for manufacturing an article, characterized in that: include: a step of exposing the substrate using the exposure apparatus according to any one of claims 1 to 18; a step of developing the exposed substrate; and The process of manufacturing an article from the developed substrate.

20. A method for measuring the positions of a first stage and a second stage in an exposure apparatus for exposing a substrate in a manner that transfers a pattern formed on an original plate to the substrate, the exposure apparatus comprising: the first stage having a first reflecting surface perpendicular to a first direction and moving back and forth in the first direction at a predetermined frequency while holding one of the substrate and the original plate; and the second stage having a second reflecting surface perpendicular to the first direction and holding the other of the substrate and the original plate, the method comprising: a first measuring step of measuring the position of the first stage in the first direction by emitting first measuring light toward the first reflecting surface and then receiving the first measuring light reflected by the first reflecting surface; a second measuring step of measuring the position of the second stage in the first direction by emitting second measuring light toward the second reflecting surface and then receiving the second measuring light reflected by the second reflecting surface; a third measurement step of measuring a wavelength of third measurement light propagating in a space closer to the first stage than the second stage; as well as The correction step corrects the measurement result of the second measurement step based on the measurement result of the third measurement step and the predetermined frequency.

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