TW202318114A - Exposure device, exposure method, and method for manufacturing article that includes a light source portion that periodically emits pulsed light and a control portion that uses the pulsed light emitted from the light source portion to control scanning exposure - Google Patents

Abstract

An object of the present invention is to provide an exposure device that helps reduce exposure unevenness occurring on a substrate. The solution is an exposure device that implements multiple times of scanning exposure on a same irradiation area of the substrate. The exposure device includes a light source portion that periodically emits pulsed light; and a control portion that uses the pulsed light emitted from the light source portion to control the multiple times of scanning exposure. The control portion is operable, in a manner of at least partly compensating uneven exposure that occurs periodically on the irradiation area in each of the multiple times of scanning exposure by means of the multiple times of scanning exposure, to change the timing of starting emission of the pulsed light from the light source portion for scanning exposure in the multiple times of scanning exposure according to the period of the exposure unevenness.

Description

Exposure device, exposure method and method of manufacturing article

The present invention relates to an exposure device, an exposure method, and a method for manufacturing an article.

As a photolithography apparatus used in the manufacturing process of semiconductor devices, etc., there is known a scanning exposure apparatus that exposes the substrate while scanning the original plate and the substrate relatively through the projection optical system, thereby transferring the pattern of the original plate as a latent image pattern. to the resist on the substrate. In recent years, a substrate coated with a thick-film resist may be used in a scanning exposure apparatus, and multiple exposures may be performed on such a substrate in order to increase the depth of field (DOF:Depth of Field). Multiple exposure refers to performing multiple scanning exposures on the same shot area in the substrate.

However, in a scanning exposure apparatus, a light source that periodically emits pulsed light may be used. In this case, in each scanning exposure, periodic exposure unevenness in the scanning direction may occur in the irradiated area of the substrate. In Patent Document 1, it is described that the relationship between the number of pulses irradiated to the substrate and the exposure unevenness is obtained in advance while the substrate moves by a unit amount in the scanning direction, and the exposure unevenness generated on the substrate is reduced based on this relationship. to set the number of pulses. In addition, the number of pulses irradiated to the substrate while the substrate is moving by a unit amount in the scanning direction is expressed in units of [pulse/mm], for example, and may be described below as the number of irradiated pulses. [Prior Art Literature] [Patent Document]

[Patent Document 1] JP-A-2010-021211

[Problem to be Solved by the Invention]

In the method described in Patent Document 1, a plurality of candidates are determined for an irradiation pulse number capable of reducing exposure unevenness based on the relationship between the number of irradiation pulses and exposure unevenness, and one irradiation pulse number is selected from the plurality of candidates. In addition, in this method, exposure unevenness can be made smaller as the number of irradiation pulses selected from a plurality of candidates increases. However, when the number of irradiation pulses is increased, the scanning speed of the substrate table needs to be reduced due to limitations in the period of pulsed light that can be emitted from the light source, etc., which may be disadvantageous in terms of throughput. Therefore, in a scanning exposure apparatus, a method that can reduce exposure unevenness even when the number of irradiation pulses is reduced is desired.

Therefore, an object of the present invention is to provide an exposure apparatus that is advantageous in reducing exposure unevenness that occurs on a substrate. [Means used to solve problems]

In order to achieve the foregoing object, an exposure apparatus according to an aspect of the present invention is an exposure apparatus that performs a plurality of scanning exposures on the same irradiation area in a substrate, and includes: a light source unit that periodically emits pulsed light; and a control unit that It uses pulsed light emitted from the light source unit to control the plurality of scanning exposures; the control unit controls the uneven exposure that periodically occurs on the irradiation area in each scanning exposure of the plurality of scanning exposures. The emission start timing of the pulsed light from the light source unit during the scanning exposure is changed in the scanning exposure according to the period of the exposure unevenness so that the plurality of scanning exposures are at least partially offset.

Further objects and other aspects of the present invention will be clarified below through preferred embodiments described with reference to the drawings. [compared to the effect of prior art]

According to the present invention, for example, it is possible to provide an exposure apparatus that is advantageous in reducing exposure unevenness that occurs on a substrate.

Embodiments will be described in detail below with reference to the drawings. In addition, the following embodiments do not limit the inventors of the claims. Although a plurality of features are described in the embodiments, all of the plurality of features are not limited to those necessary for the invention; in addition, the plurality of features may be combined arbitrarily. In addition, in the drawing, the same reference numerals are assigned to the same or similar configurations, and overlapping explanations are omitted.

<About the configuration example of the exposure device> FIG. 1 is a diagram illustrating a configuration example of an exposure apparatus 100 according to an embodiment of the present invention. In the following description, the direction parallel to the optical axis of the light emitted from the projection optical system 14 and incident on the substrate 16 is referred to as the Z-axis direction, and two directions perpendicular to each other in a plane perpendicular to the optical axis Let it be an X-axis direction and a Y-axis direction. In addition, in the following description, when described as "X-axis direction", it can be defined as including +X direction and -X direction. The same applies to the "Y-axis direction" and "Z-axis direction". In addition, in this embodiment, the Y-axis direction is demonstrated as a scanning direction.

The exposure device 100 of the present embodiment is a step-and-scan exposure device, which exposes the substrate 16 while scanning the original plate 12 and the substrate 16 relatively, thereby transferring the pattern of the original plate 12 to the substrate as a latent image pattern. resist on. Such an exposure device 100 is also called a scanning exposure device or a scanning exposure machine. In the present embodiment, the original plate 12 is, for example, a mask (reticle) made of quartz, and a circuit pattern to be transferred to each of a plurality of shot regions on the substrate 16 is formed. In addition, the substrate 16 is a wafer coated with a resist (photoresist), for example, a single crystal silicon substrate or the like can be used.

The light beam emitted from the light source unit 1 is shaped into a predetermined shape by the beam shaping unit 2 and enters the incident surface of the optical integrator 3 . The light source unit 1 includes, for example, a plurality of laser light sources, and periodically emits pulsed light so as to irradiate the substrate 16 by overlapping the plurality of pulsed lights while the substrate 16 scans a unit amount. In addition, the optical integrator 3 is composed of a plurality of minute lenses (for example, a fly's eye lens), and a plurality of secondary light sources are formed in the vicinity of the light emitting surface.

The aperture turret 4 restricts (demarcates) the size of the surface of the secondary light source through a predetermined aperture. On the aperture turntable 4, numbered (illumination pattern numbers) such as apertures with circular opening areas different from each other, annular apertures for wheel illumination, quadrupole apertures, etc., are arranged such that multiple types of coherence factor σ values can be set, for example ) of plural apertures. In addition, when changing the shape of the incident light source of illumination light, select the required aperture and insert it into the optical path. The light quantity detection unit 6 includes, for example, a photoelectric conversion element, detects a part of the pulsed light reflected by the half mirror 5 at the light quantity (light intensity) per pulse, and outputs an electric signal (detection signal) indicating the detection result to A light amount calculation unit 22 .

The condensing lens 7 transmits the light beam from the secondary light source near the output surface of the optical integrator 3 to perform Köhler illumination on a blind 8 . A slit 9 is provided near the diaphragm 8 to shape the distribution of light illuminating the diaphragm 8 into a rectangular or arcuate shape. The light passing through the diaphragm 8 and the slit 9 (also referred to as slit light) passes through the mirror 10 and the condenser lens 11, and passes through the patterned original plate 12 in a state where the illuminance and the incident angle are uniform. imaging. The original plate 12 is arranged on the conjugate plane of the diaphragm 8 . The aperture range of the diaphragm 8 is similar to the light irradiation area in the original plate 12 in terms of optical magnification ratio. During the scanning exposure, the diaphragm 8 is scanned synchronously with respect to the original plate stage 13 at an optical magnification ratio while shielding the outside of the irradiated area of the original plate 12 from light.

Master plate 12 is held by master plate station 13 . The light passing through the original plate 12 passes through the projection optical system 14 as light (pattern light) reflecting the pattern formed on the original plate 12, and is imaged in the exposure viewing angle area on the surface optically conjugate to the pattern surface of the original plate 12. . The focus detection system 15 detects the height and inclination of the exposure surface of the substrate 16 held by the substrate stage 18 . During scanning exposure, the substrate table 18 is controlled so that the exposure surface of the substrate 16 is placed on the imaging surface of the projection optical system 14 based on the information of the focus detection system 15, and the projection magnification corresponding to the projection optical system 14 is controlled. The speed ratio scans the original stage 13 and the substrate stage 18 synchronously. Accordingly, the substrate 16 is exposed, and the pattern of the original plate 12 can be transferred to the resist on the substrate 16 as a latent image pattern.

The energy measuring unit 17 is provided on the substrate stage 18 and measures the light quantity (light intensity) of the light emitted from the projection optical system 14 . The energy measuring unit 17 is constituted by, for example, a line sensor arranged along the scanning direction of the substrate 16 or a photosensor movable in the scanning direction of the substrate 16, and is arranged between its light receiving surface and the projection optical system 14. The images are roughly the same. Accordingly, the light intensity distribution per one pulse of light on the imaging plane of the projection optical system 14 can be measured. The light intensity distribution measured by the energy measuring unit 17 can also be understood as representing the light intensity distribution per one pulse of light irradiated to the substrate 16 .

Next, the configuration of the control system 20 in the exposure apparatus 100 according to the present embodiment will be described. The control system 20 of this embodiment may include a stage control unit 21 , a light quantity calculation unit 22 , a light source control unit 23 , an information input unit 24 , a timing determination unit 25 and a main control unit 26 .

The stage control unit 21 controls the synchronous scanning of the original plate 12 and the substrate 16 during scanning exposure by controlling the driving (Y-axis direction) of the original plate stage 13 and the substrate stage 18 . The stage control unit 21 can also control the driving (Z-axis direction) of the substrate stage 18 so that the exposure surface of the substrate 16 is arranged on the imaging surface of the projection optical system 14 . In addition, the light quantity calculation unit 22 converts the electric signal received from the light quantity detection unit 6 into a logical value so that the intensity of the pulsed light emitted from the light source unit 1 becomes the target intensity, and outputs it to the light source control unit 23 .

The light source control unit 23 controls the pulse oscillation frequency and pulse output energy of the light source unit 1 by outputting a trigger signal and/or an applied voltage signal according to a desired pulse light quantity. The light source control unit 23 can, according to the light quantity output value of the light quantity detection unit 6 obtained from the light quantity calculation unit 22 and the exposure parameter information (target cumulative exposure quantity, required cumulative exposure quantity precision, aperture shape, etc.) stored by the main control unit 26, Determine the trigger signal and/or apply the voltage signal. In addition, the above-mentioned exposure parameter information is input to the main control unit 26 from the information input unit 24 as a man-machine interface or a media interface, and is stored.

The timing determination unit 25 obtains part of the exposure parameter information from the information input unit 24 via the main control unit 26, and determines the exposure start timing related to the target shot area for scanning exposure among the plurality of shot areas on the substrate 16 based on the information. The exposure start timing can also be understood as the timing of starting periodic pulsed light emission from the light source unit 1 during scanning exposure (emission start timing), and is sometimes abbreviated as "emission start timing" hereinafter. For example, the timing determination part 25 can control the following time interval: from the detection of the gate signal (gate signal) supplied from the stage control part 21 until the start of outputting to the light source part 1 in order to instruct the emission of periodic pulsed light The trigger signal used. A gating signal, a signal indicating that the substrate 16 is arranged to a target position where scanning exposure can be started by controlling the driving of the substrate stage 18 , can be output from the stage control unit 21 . In addition, the timing determination unit 25 may also be configured as a part of the light source control unit 23 .

The main control unit 26 is constituted by, for example, a computer including a processor such as a CPU and a storage device such as a memory, and controls each part of the exposure apparatus 100 . For example, the main control unit 26 acquires exposure parameters and device-specific parameters acquired from the information input unit 24 , light quantity data detected by the light quantity detection unit 6 , and light quantity data measured by the energy measurement unit 17 . Moreover, various information necessary for scanning exposure is calculated based on the acquired information and data, and the light source control part 23 and the stage control part 21 are controlled. In this embodiment, the stage control unit 21, the light amount calculation unit 22, the light source control unit 23, and the timing determination unit 25 are configured differently from the main control unit 26, but they may also be configured as a part of the main control unit 26. . That is, the whole of the stage control unit 21 , the light amount calculation unit 22 , the light source control unit 23 , the timing determination unit 25 and the main control unit 26 in FIG. 1 can also be understood as a control unit.

＜About uneven exposure＞ In the exposure apparatus 100, a pattern may be formed on the substrate 16 coated with a thick-film resist. In this case, multiple exposures may be performed in order to increase the depth of field (DOF:Depth of Field). The multiple exposure refers to performing a plurality of scanning exposures on the same shot region (target shot region) on the substrate 16 . However, in the case of using the light source unit 1 that periodically emits pulsed light, periodic exposure unevenness in the scanning direction may occur in the target irradiation area in each exposure of a plurality of scanning exposures. Therefore, in the exposure apparatus 100 , it is necessary to reduce exposure unevenness that periodically occurs in the target irradiation area. Here, exposure unevenness is defined as a deviation (deviation) of the cumulative exposure amount of the substrate (target irradiation area) from the target exposure amount, and can be expressed in units of "%".

FIG. 2( a ) shows a schematic diagram of scanning exposure using a specific pulse intensity distribution shape; FIG. 2( b ) shows the relationship between the number of irradiation pulses and exposure unevenness. The number of irradiation pulses is defined as the number of pulsed lights irradiated on the substrate 16 while the substrate 16 scans a unit amount (unit distance), and can be expressed in units of [pulse/mm], for example. In the example of FIG. 2( a ), the number of irradiation pulses is "6". In addition, the shape of the pulse intensity distribution is defined as the shape of the intensity distribution of one pulse light output from the light source unit 1 or irradiated onto the substrate, and is a trapezoidal shape in the example of FIG. 2( a ).

The cumulative exposure amount at each position in the scanning direction, as shown by hatching in Fig. 2(a), is the value of the accumulated energy of a plurality of pulsed light, and the degree of uneven exposure is determined by the shape of the pulse intensity distribution and the number of irradiation pulses. amount (that is, the offset of the cumulative exposure relative to the target exposure). Specifically, as shown in FIG. 2(b), the larger the number of irradiation pulses, that is, the higher the pulse density per unit volume in the scanning direction, the smaller the influence of the slope of the trapezoidal pulse intensity distribution shape becomes. , so exposure unevenness can be reduced. In addition, in the example of FIG. 2( b ), it was confirmed that exposure unevenness was significantly reduced when the number of irradiation pulses was 4, 6, and 8 [pulse/mm].

FIG. 3 shows the relationship between the position of the irradiation area in the scanning direction and the exposure unevenness obtained when one scanning exposure is performed under the conditions of the number of irradiation pulses being 4, 6, and 8 [pulse/mm]. As shown in Figure 3, the maximum value of the exposure unevenness that occurs in the irradiated area due to one scanning exposure is 0.05 [%] or more when the number of irradiated pulses is 4 [pulse/mm], and when the number of irradiated pulses is At 6 [pulse/mm], it becomes about 0.03 [%], and when the number of irradiation pulses is 8 [pulse/mm], it becomes 0.01 [%] or less. That is, it can be seen that the maximum value of exposure unevenness decreases as the number of irradiation pulses increases. In addition, the exposure unevenness that occurs in the irradiated area due to one scanning exposure has a periodicity depending on the number of irradiation pulses, and when the number of irradiation pulses is 4 [pulse/mm], it becomes a stripe shape with a period of 250 [μm] .

Here, the amount (maximum value) of exposure unevenness can be reduced by increasing the number of irradiation pulses as shown in FIG. 3 . However, when the number of irradiation pulses is increased, the scanning speed of the substrate stage 18 needs to be reduced due to restrictions on the emission period of the pulsed light that can be emitted from the light source unit 1 , which may be disadvantageous in terms of throughput. Therefore, a method that can reduce exposure unevenness even when the number of irradiation pulses is reduced is desired. Therefore, in this embodiment, the exposure unevenness which arises in this shot area is reduced by multiple exposure which performs scanning exposure several times with respect to the same shot area. Specifically, in such a manner that the exposure unevenness that periodically occurs on the irradiated area in each of the plurality of scanning exposures is at least partially offset by the plurality of scanning exposures, the exposure unevenness cycle, and the injection start timing is changed in the plurality of scanning exposures. According to this, it is possible to reduce exposure unevenness that occurs in the irradiated area in the entirety of multiple exposures (multiple scanning exposures). Hereinafter, an example for reducing exposure unevenness will be described.

<Example 1> FIG. 4 shows the relationship between the position of the target irradiation area in the scanning direction and the exposure unevenness obtained when the irradiation pulse light is set to 4 [pulse/mm] and one scanning exposure is performed. In the aforementioned FIG. 3 , only the exposure unevenness (first exposure unevenness) that occurs in accordance with the light emission cycle of the pulsed light emitted from the light source unit 1 is shown, but in fact, as shown in FIG. 4 , it may be different from the first exposure unevenness. Exposure unevenness (second exposure unevenness) that occurs at a cycle shorter than the first exposure unevenness overlaps and overlaps. The first exposure unevenness occurs in accordance with the emission period of the pulsed light emitted from the light source unit 1, and in the example of FIG. 4, may occur in the irradiated area at a period of 250 [μs] (spatial period). On the other hand, the second exposure unevenness is caused by the optical integrator 3 and occurs at a period shorter than the first exposure unevenness. In the example of FIG. 4, it may occur at a period of 35 [μm] (a spatial period). Occurs on the irradiated area. In addition, in this embodiment 1, an example of reducing the first uneven exposure is described, in embodiment 2 an example of reducing the second uneven exposure is described, and in embodiment 3, an example of reducing the first uneven exposure and The second example of uneven exposure.

First, the processing of the timing determination unit 25 for reducing the first exposure unevenness will be described. The timing determination unit 25 acquires information related to multiple exposure via the main control unit 26 . Information related to multiple exposures may include, for example, information indicating the number of scanning exposures in multiple exposures (the number of scanning exposures performed on the same shot area) and information indicating the period (spatial period) of exposure unevenness to be reduced. Information etc. Information indicating the number of scanning exposures in multiple exposures is input by the user through the information input unit 24 and stored in the main control unit 26 , and the timing determination unit 25 can obtain the information stored in the main control unit 26 from the main control unit 26 . In addition, the information indicating the cycle of exposure unevenness to be reduced is obtained through experiments, simulations, etc. performed in advance and stored in the main control unit 26, and the timing determination unit 25 can obtain the information stored in the main control unit 26 from the main control unit 26. the information.

Next, the timing determination unit 25 determines the injection start timing in each of the plurality of scanning exposures in the multiple exposure based on the acquired information on the multiple exposure. The emission start timing, as described above, can also be understood as the timing at which periodic emission of pulsed light is started from the light source unit 1 in response to the detection of the gating signal supplied from the stage control unit 21 . That is, the emission start timing can also be understood as the time (period) from the detection of the rising edge of the gating signal supplied from the stage control unit 21 to the start of periodic emission of pulsed light from the light source unit 1 . In addition, the timing determination unit 25 may determine the time shift amount of the injection start timing in the plurality of scanning exposures in the multiple exposure. As an example, when the number of scanning exposures in multiple exposures is two, the timing determination unit 25 may determine the timing of the injection start timing in the second scanning exposure relative to the injection starting timing in the first scanning exposure. displacement. The information on the emission start timing in each scanning exposure determined by the timing determination unit 25 is supplied to the light source control unit 23 . Then, the light source control unit 23 controls the emission of the pulsed light from the light source unit 1 in each of the plurality of scanning exposures by controlling the trigger signal based on the emission start timing information.

FIG. 5 shows an example of emission start timing in each scanning exposure when the number of scanning exposures in the multiple exposure is two. The emission start timing shown in FIG. 5 can also be understood as the output timing of the trigger signal supplied from the light source control unit 23 to the light source unit 1 . The trigger signal may be a signal supplied to the light source unit 1 to cause the light source unit 1 to emit pulsed light (light emission command to the light source unit 1 ). In the example of FIG. 5 , the timing determination unit 25 determines the time from the detection of the gating signal to the start of the output of the trigger signal to the light source unit 1 (ejection start timing) as time A in the first scanning exposure. In the second scanning exposure, it is determined as the time obtained by adding the time shift amount B to the time A.

Next, a description will be given of a method of determining the emission start timing in each of the plurality of scan exposures so as to reduce the first exposure unevenness throughout the multiple exposures. In the case of the first embodiment, the timing determination unit 25 changes the period of the first exposure unevenness during the plurality of scanning exposures in such a manner that the first exposure unevenness is at least partially offset by the plurality of scanning exposures. Injection start timing. Specifically, when the number of scanning exposures in multiple exposures is N, the timing determination unit 25 changes the emission start timing to correspond to 1/N of the period of the first exposure unevenness in the multiple scanning exposures. time. Here, as the information indicating the period of the first uneven exposure, information obtained through experiments and simulations performed in advance can be used, but information indicating the emission period of the pulsed light emitted from the light source unit 1 can also be used. This is because the period of the first uneven exposure corresponds to the emission period of the pulsed light emitted from the light source unit 1 .

FIG. 6 shows an example of first exposure unevenness that occurs in each scanning exposure when the number of scanning exposures in the multiple exposure is two. In FIG. 6 , it is shown that the irradiation pulse light is set to 4 [pulse/mm], and the emission cycle of the pulse light emitted from the light source unit 1 is set to 250 [μs] (that is, the pulse oscillation frequency is set to 4 [kHz]. ])Case. In addition, the first exposure unevenness generated in the target shot area due to the first scanning exposure is shown by a solid line, and the first exposure unevenness generated in the target shot area due to the second scanning exposure is shown by a broken line.

In the example of FIG. 6, the timing determination unit 25 determines that the emission start timing in the second scanning exposure is shifted by half of the cycle of the first exposure unevenness from the emission start timing in the first scanning exposure. (125[μm]) equivalent time. That is, the time shift B of the emission start timing in the second scanning exposure relative to the emission start timing in the first scanning exposure is determined to correspond to half (125 [μm]) of the period of the first exposure unevenness time. Here, the first exposure unevenness occurs according to the emission period of the pulsed light emitted from the light source unit 1, so the timing shift can be determined according to the emission period of the pulsed light emitted from the light source unit 1 and the number of scanning exposures in the multiple exposure. Quantity B. That is, the amount of time shift B can be determined to be 125 [μs], which is half (1/2) of the emission period of the pulsed light emitted from the light source unit 1 .

Accordingly, the phase (peak/trough position) of the first uneven exposure occurring in the second scanning exposure can be compared to the phase (peak/valley position) of the first uneven exposure occurring in the first scanning exposure. trough position), offset by 180 degrees. As a result, the first exposure unevenness that occurred in the first scanning exposure and the first exposure unevenness that occurred in the second scanning exposure are at least partially offset, so as shown in FIG. The first exposure unevenness is reduced overall for multiple scan exposures. FIG. 7 is a diagram in which the first exposure unevenness occurring in the first scanning exposure and the first exposure unevenness occurring in the second scanning exposure are superimposed.

Here, in the above, the case where the number of times of scanning exposure in the multiple exposure is 2 was exemplified, but the reduction effect of the first exposure unevenness can be similarly obtained in the case of 3 or more times. For example, when the number of scanning exposures in multiple exposures is set to N times, the time shift amount Sn [μs] of the emission start timing in multiple scanning exposures can be determined as the emission of pulsed light emitted from the light source unit 1. 1/N of the period Tp [μs]. In addition, when the emission start timing in the first scanning exposure is used as a reference, the time shift amount Sn [μs] of the emission start timing in the n-th scanning exposure can be determined as the light emission of the pulsed light emitted from the light source unit 1 (n-1)/N of period Tp[μs]. The following is a calculation example of the time shift amount Sn in the case of Tp=250 [μs], N=3, 4. In addition, n is any integer (natural number) from 1 to N, and the amount of time shift Sn is the same as the amount of time shift B in FIG. 5 . Tp=250, N=3 case: n=(2, 3), Sn=(83, 167) Tp=250, N=4 case: n=(2, 3, 4), Sn=(63, 125, 188)

<Example 2> In this second embodiment, an example of reducing the second uneven exposure will be described. The second exposure unevenness is caused by the optical integrator 3 as described above, and occurs in the target shot area at a cycle shorter than that of the first exposure unevenness. In the present embodiment 2, similarly to the embodiment 1, the timing determination unit 25 acquires information related to multiple exposures, and determines the injection start timing in each scanning exposure in the plurality of scanning exposures in the multiple exposures based on the information. . However, in the second embodiment, information indicating the cycle of the second uneven exposure is used as the information indicating the cycle of the uneven exposure to be reduced. The information indicating the period of the second uneven exposure is obtained through experiments, simulations, etc. performed in advance and stored in the main control unit 26 , and the timing determination unit 25 can obtain the information stored in the main control unit 26 from the main control unit 26 .

In the case of the second embodiment, the timing determination unit 25 changes the time sequence during the plurality of scanning exposures in accordance with the period of the second exposure unevenness so that the second exposure unevenness is at least partially offset by the plurality of scanning exposures. Injection start timing. Specifically, when the number of scanning exposures in multiple exposures is N, the timing determination unit 25 changes the emission start timing to correspond to 1/N of the period of the second exposure unevenness in the multiple scanning exposures. time. For example, assume a case where the number N of scanning exposures in the multiple exposure is 2 and the period Te of the second exposure unevenness is 35 [μm]. In this case, the timing determination unit 25 determines that the emission start timing in the second scanning exposure is offset from the emission starting timing in the first scanning exposure by half (17.5[ μm]) equivalent time. That is, the amount of time shift Sn of the emission start timing in the second scanning exposure relative to the emission start timing in the first scanning exposure is determined to correspond to half (17.5 [μm]) of the period of the second exposure unevenness time.

Accordingly, the phase (peak/trough position) of the first uneven exposure occurring in the second scanning exposure can be compared to the phase (peak/valley position) of the second uneven exposure occurring in the second scanning exposure. trough position), offset by 180 degrees. As a result, the second exposure unevenness that occurred in the first scanning exposure and the second exposure unevenness that occurred in the second scanning exposure are at least partially offset, so as shown in FIG. The second exposure unevenness is reduced overall for multiple scan exposures. FIG. 8 is a diagram in which the second exposure unevenness generated in the first scanning exposure and the second exposure unevenness occurring in the second scanning exposure are superimposed.

Tp[μs]：從光源部1射出的脈衝光的發光週期 Pm[脈衝/mm]：照射脈衝數 Te[μm]：應降低的曝光不均的週期 n[第～次]：1～N中的任一整數 N[次]：多重曝光中的掃描曝光的次數 Sn[μs]：時移量 Here, the calculation formula for the amount of time shift Sn will be described. The calculation formula of the time shift Sn can be generalized from Embodiment 1 and Embodiment 2, and can be represented by the following formula (1). In addition, when the injection start timing in the first scanning exposure is taken as a reference, the calculation formula of the time shift amount Sn of the injection starting timing in the nth scanning exposure (n is any integer from 1 to N) is, It can be represented by the following formula (2). Each of the following formulas (1) to (2) can be used to calculate either one of the first exposure unevenness described in Example 1 and the second exposure unevenness described in Example 2. The time shift Sn.

Tp [μs]: Light emission period of pulsed light emitted from the light source unit 1 Pm [pulse/mm]: Number of irradiation pulses Te [μm]: Period n of exposure unevenness to be reduced [~times]: 1 to N Any integer N[times]: the number of scanning exposures in multiple exposures Sn[μs]: the amount of time shift

For example, it is assumed that the number N of scanning exposures in multiple exposures is set to 2, the pulsed light irradiation Pm is set to 4 [pulse/mm], and the emission period Tp of the pulsed light emitted from the light source unit 1 is set to 250 [μs] ]Case. In this case, as described in Example 1, the amount of time shift Sn for reducing the first exposure unevenness (period Te: 250 [μm]) becomes Sn={Tp×Te/(1/Pm)} ×1/N={250×250/(1/4×1000)}×1/2=125[μs]. In addition, as described in Example 2, the amount of time shift Sn for reducing the second exposure unevenness (period Te: 35 [μm]) becomes Sn={Tp×Te/(1/Pm)}×1 /N={250×35/ (1/4×1000)}×1/2 =17.5[μs].

<Example 3> In this third embodiment, an example of simultaneously reducing both the first uneven exposure and the second uneven exposure will be described. In the present embodiment 3, similarly to the embodiments 1-2, the timing determination unit 25 acquires information related to multiple exposures, and based on the information, determines the number of exposures in each of the plurality of scanning exposures in the multiple exposures. Injection start timing. However, in the third embodiment, information indicating the period of the first uneven exposure and information indicating the period of the second uneven exposure are used as the information indicating the period of the uneven exposure to be reduced. In addition, the timing determination unit 25, according to the period of the first uneven exposure and the period of the second uneven exposure, in such a manner that the first uneven exposure and the second uneven exposure are at least partially offset by the plurality of times of scanning exposure. Change the injection start timing during multiple scanning exposures.

Specifically, when the number of scanning exposures in multiple exposures is N times, the timing determination unit 25 selects a period close to the first uneven exposure period among odd multiples of 1/N of the second uneven exposure period. The value of 1/N of (preferably, the nearest value) determines the amount of time shift Sn. For example, assume that the number N of scanning exposures in multiple exposures is two, the period of the first uneven exposure is 250 [μm], and the period of the second uneven exposure is 35 [μm]. In this case, the value (119[μm]) closest to the half value of the period (250[μm]) of the first uneven exposure period (250[μm]) among odd multiples of the half value of the second period of uneven exposure (35[μm]) μm]), set the period Te of the exposure unevenness to be reduced, and determine the timing shift amount Sn according to the above formula (1) or formula (2). Accordingly, the exposure unevenness (first exposure unevenness, second exposure unevenness) that occurs in each scanning exposure is at least partially offset in the plurality of scanning exposures, so as shown in FIG. The overall reduction of the exposure unevenness in the multiple scanning exposures.

Here, in the above, the case where there are two types of periodic components of exposure unevenness has been described, but there may be M types of periodic components of exposure unevenness (M is an integer greater than or equal to 3). In this case, the timing determination unit 25 selects each of the closest to the second shortest periodic component to the Mth shortest periodic component from odd multiples of 1/N of the shortest periodic component among the M types of periodic components. Values that are odd multiples of 1/N. Then, using the selected value as the period Te of exposure unevenness to be reduced, the amount of time shift Sn is determined according to the above formula (1) or formula (2). By using the time shift amount Sn determined in this way, exposure unevenness of all periodic components can be reduced.

As described above, in the present embodiment, exposure unevenness occurring in the shot area is reduced by multiple exposure in which scanning exposure is performed a plurality of times for the same shot area. Specifically, in such a manner that the exposure unevenness that periodically occurs on the irradiated area in each of the plurality of scanning exposures is at least partially offset by the plurality of scanning exposures, the exposure unevenness cycle, and the injection start timing is changed in the plurality of scanning exposures. According to this, it is possible to reduce exposure unevenness that occurs in the irradiated area in the entirety of multiple exposures (multiple scanning exposures). In addition, the amount of time shift Sn, as described in Embodiments 1 to 3, can be determined from the periodic component of exposure unevenness calculated from the shape of the pulse intensity distribution, the number of irradiation pulses, and the design information of optical components (optical integrators, etc.). decision, but not limited to this. For example, the amount of time shift Sn may be determined based on the result of Fourier analysis of an image obtained by observing the substrate subjected to the first scanning exposure through a scanning electron microscope (SEM).

<Embodiments of the manufacturing method of the article> The method of manufacturing an article according to the embodiment of the present invention is suitable for manufacturing articles such as microdevices such as semiconductor devices and elements having a fine structure. The manufacturing method of the article of the present embodiment includes: a process of forming a latent image pattern (process of exposing the substrate) using the above-mentioned exposure device (exposure method) on the photosensitive agent coated on the substrate; A process of developing (processing) a patterned substrate. In addition, this manufacturing method includes other well-known procedures (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method of manufacturing an article according to this embodiment is advantageous in at least one of article performance, quality, productivity, and production cost compared to conventional methods.

The invention is not limited to the aforementioned embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the scope of the patent application is drafted to disclose the scope of the invention.

1: Light source department 12: Original 14: Illumination optical system 16: Substrate 20: Control system 21: Stage Control Department 22: Light Quantity Calculation Department 23: Light source control department 24:Information input department 25: Timing Decision Department 26: Main Control Department 100: Exposure device

[ Fig. 1 ] A diagram showing a configuration example of an exposure apparatus. [ Fig. 2 ] A schematic diagram of scanning exposure using a specific pulse intensity distribution shape; and a graph showing the relationship between the number of irradiation pulses and exposure unevenness. [ Fig. 3] Fig. 3 is a graph showing the relationship between the position of the shot area in the scanning direction and exposure unevenness. [ Fig. 4] Fig. 4 is a graph showing the relationship between the position of the shot area in the scanning direction and the exposure unevenness. [ Fig. 5] Fig. 5 is a diagram showing an example of an injection start timing in each scanning exposure when the number of scanning exposures in the multiple exposure is two. [ Fig. 6] Fig. 6 is a diagram illustrating an example of first exposure unevenness that occurs in each scanning exposure. [FIG. 7] It is a figure which shows the example which reduced the 1st exposure unevenness in Example 1. [FIG. [ Fig. 8] Fig. 8 is a diagram showing an example in which the second exposure unevenness was reduced in Example 2. [FIG. 9] It is a figure which showed the example which reduced the 1st exposure unevenness and the 2nd exposure unevenness in Example 3. [FIG.

1: Light source department

2: Beam Shaper

3: Optical integrator

4: Aperture turntable

5: half mirror

6: Light quantity detection unit

7: Concentrating lens

8: Aperture

9: Slit

10: Mirror

11: Concentrating lens

12: Original

13: Original desk

14: Illumination optical system

15: Focus detection system

16: Substrate

17: Energy Measurement Department

18: Substrate table

20: Control system

21: Stage Control Department

22: Light Quantity Calculation Department

23: Light source control department

24:Information input department

25: Timing Decision Department

26: Main Control Department

100: Exposure device

Claims (11)

An exposure device that performs multiple scanning exposures for the same irradiation area in a substrate, have: a light source section that periodically emits pulsed light; and a control unit that uses pulsed light emitted from the light source unit to control the plurality of times of scanning exposure; The control unit is configured to at least partially offset exposure unevenness periodically occurring on the irradiated area in each of the plurality of scanning exposures by the plurality of scanning exposures. The emission start timing of the pulsed light from the light source unit in the scanning exposure is changed in the scanning exposure at a uniform cycle. The exposure device as claimed in item 1, wherein, The exposure unevenness includes a first exposure unevenness that occurs in accordance with the light emission period of the pulsed light emitted from the light source unit, The control unit changes the injection start timing during the plurality of scanning exposures in accordance with a cycle of the first exposure unevenness so that the first exposure unevenness is at least partially offset by the plurality of scanning exposures. The exposure device as claimed in item 2, wherein, The control unit determines a time shift amount of the emission start timing in the plurality of scanning exposures based on an emission period of the pulsed light emitted from the light source unit and the number of scanning exposures on the irradiation region. The exposure device as claimed in item 1, wherein, The exposure unevenness includes a second exposure unevenness occurring at a period shorter than a period of the first exposure unevenness occurring in accordance with the emission period of the pulsed light emitted from the light source unit, The control unit changes the injection start timing during the plurality of scanning exposures in accordance with a cycle of the second exposure unevenness so that the second exposure unevenness is at least partially offset by the plurality of scanning exposures. The exposure device as claimed in item 4, wherein, The control unit is based on the emission period of the pulsed light emitted from the light source unit, the period of the second uneven exposure, the number of pulsed lights irradiated on the substrate during the scanning unit period of the substrate, and the scanning of the irradiation area. The number of exposures determines the amount of time shift of the injection start timing in the plurality of scanning exposures. The exposure device as claimed in item 1, wherein, The exposure unevenness includes a first exposure unevenness that occurs in accordance with the light emission period of the pulsed light emitted from the light source unit and a second exposure unevenness that occurs at a period shorter than that of the first exposure unevenness, When the number of times of scanning exposure for the shot area is set to N, the control unit selects one of the odd multiples of 1/N of the second uneven exposure period that is close to 1 of the first uneven exposure period. The value of /N determines the amount of time shift of the injection start timing in the plurality of scanning exposures. The exposure device according to any one of claims 1 to 6, wherein, In the control unit, Tp is the emission period of the pulsed light emitted from the light source unit, Te is the period of the exposure unevenness to be reduced, and the pulse light irradiated to the substrate during the scanning unit amount of the substrate is When the quantity of light is set to Pm and the number of times of scanning exposure for the aforementioned irradiation area is set to N, the time shift amount Sn of the aforementioned emission start timing in the aforementioned plurality of scanning exposures is determined as follows: Sn={Tp×Te/(1/Pm)}×1/N. The exposure device according to any one of claims 1 to 6, wherein, The control unit changes the emission start timing by controlling the light source unit. The exposure device according to any one of claims 1 to 6, wherein, The light source unit periodically emits pulsed light so that the plurality of pulsed lights overlap and irradiate the substrate during a unit scan period of the substrate. An exposure method that uses pulsed light periodically emitted from a light source unit to perform a plurality of scanning exposures on the same irradiation area in a substrate, According to the period of the aforementioned uneven exposure, in such a manner that the exposure unevenness that periodically occurs on the aforementioned irradiation area in each of the aforementioned plurality of scanning exposures is at least partially offset by the aforementioned plurality of scanning exposures, The emission start timing of the pulsed light from the light source unit in the scanning exposure is changed in the plurality of scanning exposures. a method of manufacture of an article, Include: an exposure procedure for exposing the substrate using the exposure method of claim 10; and A processing procedure for processing the aforementioned substrate exposed in the aforementioned exposure procedure; An article is manufactured from the aforementioned substrate processed in the aforementioned processing procedure.

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