Lithography apparatus, lithography method, and method for producing article

Abstract

To provide a technique advantageous for improving measurement accuracy of an alignment measurement system.SOLUTION: A lithography apparatus for forming a pattern on a substrate through an original plate has: a stage for holding the original plate or the substrate; an alignment measurement system for measuring a position of the mark by storing light from a mark provided on the stage and performing photoelectric conversion; and a control part for controlling the alignment measurement system, wherein the control part acquires information exhibiting a relation between a storage time for storing the light from the mark and a degree of variation in measurement results of the position of the mark in the alignment measurement system, and determines the storage time to be set on the alignment measurement system in treatment for causing the alignment measurement system to measure the position of the mark on the basis of the information.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a lithographic apparatus, a lithographic method, and a method of manufacturing an article.

Background Art

[0002] An exposure apparatus used in a manufacturing process (lithography process) of a semiconductor element or the like includes a substrate stage that holds a substrate, and a projection optical system that projects a pattern of a reticle onto the substrate. The substrate stage is generally configured to be drivable along a plane perpendicular to the exposure light (optical axis of the projection optical system) incident on the substrate.

[0003] In an exposure apparatus, in order to expose an appropriate position on a substrate, it is necessary to accurately measure the position of an alignment mark on a reference plate disposed on the substrate stage and the position of an alignment mark on the substrate by an alignment measurement system. On the other hand, when the substrate stage is driven, the alignment measurement system vibrates through a structure (main body) that supports the substrate stage. The relative vibration between the alignment measurement system and the structure, or the vibration inside the alignment measurement system, is a factor that reduces the measurement accuracy of the alignment mark.

[0004] Therefore, a technique for reducing the influence of vibration of the alignment measurement system on the measurement accuracy has been proposed (see Patent Document 1). Patent Document 1 discloses a technique for improving the measurement accuracy of an alignment measurement system by measuring the relative position between a substrate stage and the alignment measurement system a plurality of times and summing up the measurement data.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the prior art, in addition to the need for measuring means for measuring the relative position between the substrate stage and the alignment measurement system, the time required for multiple measurements (measurement time) becomes long, leading to a decrease in productivity.

[0007] The present invention has been made in view of such problems of the prior art, and an exemplary object thereof is to provide a technique advantageous for improving the measurement accuracy of an alignment measurement system.

Means for Solving the Problems

[0008] In order to achieve the above object, a lithography apparatus according to one aspect of the present invention is a lithography apparatus for forming a pattern on a substrate via a reticle, including a stage for holding the reticle or the substrate, an alignment measurement system for measuring the position of a mark by accumulating light from the mark provided on the stage and performing photoelectric conversion, and a control unit for controlling the alignment measurement system. The control unit acquires information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement results of the position of the mark, and based on the information, determines the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system.

[0009] A further object or other aspect of the present invention will be clarified by the embodiments described below with reference to the accompanying drawings.

Effects of the Invention

[0010] According to the present invention, for example, a technique advantageous for improving the measurement accuracy of an alignment measurement system is provided.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and duplicate descriptions are omitted.

[0013] <First Embodiment> FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus EXA as one aspect of the present invention. The exposure apparatus EXA is used in the manufacturing process of devices such as semiconductor elements, and is a lithography apparatus that forms a pattern on a substrate by exposing the substrate through a master plate (reticle or mask). The exposure apparatus EXA projects the pattern (image) of the master plate formed on the master plate onto the substrate 3 through a projection optical system, and performs a process (exposure process) of transferring the pattern of the master plate to the substrate.

[0014] The exposure apparatus EXA includes a master stage 2 that holds the master plate 1, a substrate stage 4 that holds the substrate 3, and an illumination optical system 5 that illuminates the master plate 1 held by the master stage 2. Further, the exposure apparatus EXA includes a projection optical system 6 that projects the pattern (image) of the master plate 1 illuminated by the illumination optical system 5 onto the substrate 3 held by the substrate stage 4, and a control unit 50 that comprehensively controls the overall operation of the exposure apparatus EXA.

[0015] In this embodiment, the exposure apparatus EXA is embodied as a scanning exposure apparatus (scanner) that transfers the pattern of the original plate 1 to the substrate 3 while synchronously scanning the original plate 1 and the substrate 3 in the scanning direction with respect to each other (i.e., in a step-and-scan method). However, the exposure apparatus EXA may be embodied as an exposure apparatus (stepper) that transfers the pattern of the original plate 1 to the substrate 3 by fixing the original plate 1 (i.e., in a step-and-repeat method).

[0016] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system in which the direction parallel to the surface on which the substrate 3 is disposed is defined as the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are defined as the X-direction, Y-direction, and Z-direction, respectively, and the rotations about the X-axis, Y-axis, and Z-axis are defined as θX, θY, and θZ, respectively.

[0017] The illumination optical system 5 illuminates the original plate 1 (a predetermined illumination region thereof) with light having a uniform illuminance distribution. The light for illuminating the original plate 1, i.e., the exposure light, includes, for example, mercury lamp light, KrF excimer laser, ArF excimer laser, and extreme ultraviolet light (EUV light).

[0018] The original plate stage 2 is a stage for holding and positioning the original plate 1. The original plate stage 2 is configured to be two-dimensionally drivable within a plane perpendicular to the optical axis of the projection optical system 6, i.e., within the XY plane, and rotatable in the θZ direction via a drive mechanism including a linear motor or the like. In this embodiment, the original plate stage 2 is configured with three-axis drive, but may be configured with any of one-axis drive to six-axis drive.

[0019] A mirror 7 is provided on the original plate stage 2. Further, a laser interferometer 9 for measuring the position of the mirror 7 is provided at a position facing the mirror 7. The positions of the original plate 1 held by the original plate stage 2 in the two-dimensional direction and the rotational direction are measured in real time by the laser interferometer 9, and the measurement results are output to the control unit 50. The control unit 50 positions the original plate 1 held by the original plate stage 2 based on the measurement results of the laser interferometer 9.

[0020] The projection optical system 6 includes a plurality of optical elements and is an optical system that projects the pattern of the original plate 1 onto the substrate 3 at a predetermined projection magnification. The projection magnification of the projection optical system 6 is, for example, 1 / 2 or 1 / 5.

[0021] The substrate stage 4 is a stage for holding and positioning the substrate 3. The substrate stage 4 includes, for example, a θZ tilt stage that holds the substrate 3 via a chuck, an XY stage that supports the θZ tilt stage, and a base that supports the XY stage. The substrate stage 4 is driven via a drive mechanism including a linear motor or the like.

[0022] A mirror 8 is provided on the substrate stage 4. Also, a laser interferometer 10 for measuring the XY direction and a laser interferometer 12 for measuring the Z direction are provided at positions facing the mirror 8. The two-dimensional direction and the rotational direction positions of the substrate 3 (held by the substrate stage 4) are measured in real time by the laser interferometers 10 and 12, and the measurement results are output to the control unit 50. The control unit 50 positions the substrate 3 held by the substrate stage 4 based on the measurement results of the laser interferometers 10 and 12.

[0023] In the vicinity of the original plate stage 2, an original plate alignment measurement system 13 is provided. The original plate alignment measurement system 13 measures the position of the original plate reference mark provided on the original plate 1 held by the original plate stage 2 and the position of the stage reference mark provided on the stage reference plate arranged on the original plate stage 2. Note that the stage reference mark may be a reflection type mark or a transmission type mark. The original plate alignment measurement system 13 measures the positions of these marks by accumulating and photoelectrically converting the light from the original plate reference mark and the stage reference mark. Specifically, the original plate alignment measurement system 13 includes a CMOS sensor in which photoelectric conversion elements are two-dimensionally arranged, accumulates (detects) the light from the original plate reference mark and the stage reference mark, and converts it into a signal including their position information. Based on the signal output from the original plate alignment measurement system 13, alignment between the original plate 1 and the substrate 3 is performed. At this time, by aligning the positions and focus of the original plate reference mark and the stage reference mark, the relative positional relationship (X, Y, Z) between the original plate 1 and the substrate 3 can be aligned.

[0024] As shown in FIG. 2, the substrate alignment measurement system 16 measures the position of the substrate reference mark 19 provided on the substrate 3 held by the substrate stage 4 and the position of the stage reference mark 18 provided on the stage reference plate 11 arranged on the substrate stage 4. FIG. 2 is a diagram showing the configuration of the stage reference plate 11 arranged on the substrate stage 4. The stage reference plate 11 is arranged at the corner of the substrate stage 4 so as to be at the same height as the surface of the substrate 3.

[0025] The substrate alignment measurement system 16 measures the positions of these marks by accumulating light from the substrate reference mark 19 and the stage reference mark 18 and performing photoelectric conversion. Specifically, the substrate alignment measurement system 16 includes a CMOS sensor or the like in which photoelectric conversion elements are two-dimensionally arranged. The substrate alignment measurement system 16 captures images of the substrate reference mark 19 and the stage reference mark 18 for a certain period of time, accumulates the light from them as charges (two-dimensional charge information), and converts it into a signal including their position information. Hereinafter, in the substrate alignment measurement system 16, the time for capturing images of various reference marks, that is, the time for accumulating light from the reference marks, is referred to as the accumulation time.

[0026] The focus / tilt measurement system 15 includes an irradiation system that irradiates light onto the substrate 3 held by the substrate stage 4, and a detection system that detects the reflected light from the substrate 3. The focus / tilt measurement system 15 has a function of measuring the focus and tilt of the substrate 3.

[0027] The control unit 50 is composed of a computer (information processing device) including, for example, a CPU and a memory, and comprehensively controls each part of the exposure apparatus EXA according to a program stored in a storage unit or the like.

[0028] In the exposure apparatus EXA, it is vibrated by vibrations transmitted from the structure that supports the substrate alignment measurement system 16. Examples of the vibration source that vibrates the structure include the reaction force of driving units such as the substrate stage 4 and the reticle stage 2, and vibrations caused by air conditioning inside the exposure apparatus EXA.

[0029] When the substrate alignment measurement system 16 is vibrated, relative vibrations between the substrate alignment measurement system 16 and the structure, or vibrations inside the substrate alignment measurement system 16 are caused. Generally, the substrate alignment measurement system 16 performs measurement in a state where vibrations that occur sporadically, such as driving of the unit, have converged, but vibrations that are constant and have a constant amplitude due to air conditioning or the like remain.

[0030] When the substrate alignment measurement system 16 vibrates at a constant amplitude, the substrate alignment measurement system 16, specifically, the mark imaged by the CMOS sensor (photoelectric conversion element) vibrates on the imaging surface at the natural period (eigenvalue) of the vibration of the substrate alignment measurement system 16. Here, the natural period corresponds to the reciprocal of the natural vibration frequency (resonance frequency) of the substrate alignment measurement system 16.

[0031] Figure 3 is a diagram showing the vibration of the mark imaged by the substrate alignment measurement system 16, that is, the vibration of the mark on the imaging surface of the substrate alignment measurement system 16. In Figure 3, the vertical axis represents the position of the mark, and the horizontal axis represents the integration time (t), showing the vibration Y(t) of the mark. Referring to Figure 3, the center position of the vibration of the mark on the imaging surface of the substrate alignment measurement system 16 is the position (true value) of the mark that does not include the measurement error due to vibration. Therefore, if the amplitude of the vibration of the mark is A, the natural period of the vibration of the substrate alignment measurement system 16 is T, and the initial phase is k, the vibration Y(t) of the mark is defined by the following formula (1).

[0032]

Equation

[0033] Also, when the integration time is t i the measurement error F(t) of the mark due to the vibration of the mark is calculated by the following formula (2).

[0034]

Equation

[0035] Referring to formula (2), the measurement error F(t) of the mark is the integration time t, which is the time for accumulating the light from the mark, in the substrate alignment measurement system 16. iBy setting it to an integer multiple of the natural period T of the vibration of the substrate alignment measurement system 16, it becomes zero regardless of the initial phase. The measurement error F(t) of the mark becomes zero regardless of the initial phase at a location referred to as a "node", as shown in FIG. 3. It can be seen that the nodes exist at integer multiples of the natural period of the vibration of the substrate alignment measurement system 16.

[0036] Therefore, in the present embodiment, an integer multiple of the natural period of the vibration of the substrate alignment measurement system 16 is set as the integration time in the substrate alignment measurement system 16 for the process of measuring the position of the mark (for example, the alignment process) by the substrate alignment measurement system 16. Thereby, it becomes possible to reduce (minimize) the measurement error caused by the vibration of the substrate alignment measurement system 16. Also, generally, the measurement error of high-frequency noise is suppressed by making the integration time sufficiently long. However, as described above, by setting an integer multiple of the natural period of the vibration of the substrate alignment measurement system 16, specifically, from 1 to 5 times, as the integration time in the substrate alignment measurement system 16, it becomes possible to suppress the measurement error of high-frequency noise without increasing the integration time. Thus, according to the present embodiment, it is possible to contribute not only to the measurement accuracy of the substrate alignment measurement system 16 but also to the improvement of productivity. Note that since the natural period of the vibration of the substrate alignment measurement system 16 differs for each device, it is preferable to optimize the integration time set in the substrate alignment measurement system 16 for each device.

[0037] Hereinafter, a specific method for setting an integer multiple of the natural period of the vibration of the substrate alignment measurement system 16 as the integration time in the substrate alignment measurement system 16 will be described. In the present embodiment, a control unit 50 that controls the substrate alignment measurement system 16 sets the integration time for the substrate alignment measurement system 16.

[0038] First, in the control unit 50, as shown in FIG. 4, information indicating the relationship between the accumulation time for accumulating light from the mark and the degree of variation in the measurement results of the position of the mark (degree of variation in the mark measurement position) in the substrate alignment measurement system 16 is acquired. FIG. 4 is a diagram showing the relationship between the accumulation time and the degree of variation in the mark measurement position in the substrate alignment measurement system 16. The vertical axis employs the degree of variation in the mark measurement position, and the horizontal axis employs the accumulation time. Here, the degree of variation in the mark measurement position can be, for example, the standard deviation, variance, or coefficient of variation regarding a plurality of measurement results obtained by measuring the position of the mark a plurality of times. Information such as that shown in FIG. 4 can be acquired, for example, by setting each of a plurality of accumulation times in the substrate alignment measurement system 16 and measuring the position of the mark a plurality of times by the substrate alignment measurement system 16 with each accumulation time set. In the present embodiment, as information indicating the relationship between the accumulation time and the degree of variation in the mark measurement position in the substrate alignment measurement system 16, a function IF that approximately represents such a relationship is acquired. Then, based on the information shown in FIG. 4, the accumulation time to be set in the substrate alignment measurement system 16 is determined so that an integer multiple of the natural period of vibration of the substrate alignment measurement system 16 is set as the accumulation time.

[0039] Referring to FIG. 4, the degree of variation in the mark measurement position converges as the accumulation time increases. And the degree of variation in the mark measurement position converges while including a plurality of minimum points where the degree of variation in the mark measurement position becomes a minimum value at a time when the accumulation time is an integer multiple of the natural period of the vibration of the substrate alignment measurement system 16. Therefore, based on the plurality of minimum points included in the function IF showing the relationship between the accumulation time in the substrate alignment measurement system 16 and the degree of variation in the mark measurement position, the accumulation time to be set in the substrate alignment measurement system 16 is determined. Specifically, an integer multiple of the accumulation time difference (natural period T), which is the difference between one minimum point (first minimum point) LM1 and the minimum point (second minimum point) LM2 closest to the minimum point LM1 among the plurality of minimum points included in the function IF, is determined as the accumulation time to be set. Also, the period (natural period T) of the accumulation time may be obtained from the plurality of minimum points (included in the function IF), and an integer multiple of such a period of the accumulation time may be determined as the accumulation time to be set. In this way, it is possible to obtain the natural period of the vibration of the substrate alignment measurement system 16 from the relationship between the accumulation time in the substrate alignment measurement system 16 and the degree of variation in the mark measurement position. In other words, the accumulation time to be set in the substrate alignment measurement system 16 can be optimized from the relationship between the accumulation time in the substrate alignment measurement system 16 and the degree of variation in the mark measurement position.

[0040] As the vibration of the substrate alignment measurement system 16, generally, there are a plurality of vibration modes. Therefore, generally, it is preferable to determine the accumulation time to be set in the substrate alignment measurement system 16 by limiting it to the low-order vibration modes that have a relatively large influence on the measurement result of the mark (the degree of variation in the mark measurement position). However, depending on the direction of the vibration of the substrate alignment measurement system 16 and the vibration displacement amount sensitive to measurement, even in the case of high-order vibration modes, the influence on the measurement result of the mark may be large. In such a case, the vibration mode having the greatest influence may be obtained from the time when the degree of variation in the mark measurement position becomes a minimum value, and the accumulation time to be set in the substrate alignment measurement system 16 may be determined by limiting it to such a vibration mode.

[0041] Also, the substrate alignment measurement system 16 generally measures the position of the stage reference mark 18 in two directions, i.e., the X direction and the Y direction, as shown in FIG. 2. The vibrations of the substrate alignment measurement system 16 that affect these measurement results may be in different vibration modes in the X direction and the Y direction respectively. In this case, since the integration time to be set for the substrate alignment measurement system 16 is also different for each of the X direction and the Y direction, it is preferable to individually determine (set) the integration time to be set for the substrate alignment measurement system 16 for each direction.

[0042] Also, depending on the types of the substrate 3 and the stage reference plate 11, the amount of light incident on the substrate alignment measurement system 16 from the substrate reference mark 19 and the stage reference mark 18, i.e., the integrated light amount accumulated in the substrate alignment measurement system 16, may be insufficient. In this case, in the substrate alignment measurement system 16, it is possible to increase the integrated light amount by increasing the integration time. At this time, it is preferable to determine the integration time to be set for the substrate alignment measurement system 16 so that the integration time increases by an integer multiple of the natural period of the vibration of the substrate alignment measurement system 16. Thereby, it becomes possible to measure the substrate reference mark 19 and the stage reference mark 18 with an appropriate amount of light without increasing the measurement error caused by the vibration of the substrate alignment measurement system 16.

[0043] <Second Embodiment> In the first embodiment, the accumulation time (determination) to be set in the substrate alignment measurement system 16 was described in relation to the mark provided on the substrate stage 4 and the substrate alignment measurement system 16 that measures the position of such a mark. This can also be applied in relation to the mark provided on the original plate stage 2 and the original plate alignment measurement system 13 that measures the position of such a mark. Specifically, information indicating the relationship between the accumulation time for accumulating light from the mark in the original plate alignment measurement system 13 and the degree of variation in the measurement result of the mark position (the degree of variation in the mark measurement position) is obtained. Then, based on the information indicating the relationship between the accumulation time and the degree of variation in the mark measurement position, the accumulation time to be set in the original plate alignment measurement system 13 is determined in the process of measuring the mark position by the original plate alignment measurement system 13.

[0044] <Third Embodiment> In the first and second embodiments, a method for determining the accumulation time to be set in each alignment measurement system was described by focusing on the vibration of the substrate alignment measurement system 16 and the original plate alignment measurement system 13. In this embodiment, the case where the vibration of the mark caused by the elasticity of the structure from the mirror 8 provided on the substrate stage 4 to the substrate 3 affects the measurement result of such a mark will be described, although the alignment measurement system has sufficient rigidity from the perspective of measurement.

[0045] Since the vibration of the structure from the mirror 8 to the substrate 3 is not a measurement target by the laser interferometer 10, it becomes a measurement error that affects the measurement result of the mark. When the structure from the mirror 8 to the substrate 3 is vibrating, on the imaging surface of the substrate alignment measurement system 16, as shown in FIG. 3, the mark vibrates. Therefore, similar to the first embodiment, by setting an integer multiple of the natural period of the vibration of the structure from the mirror 8 provided on the substrate stage 4 to the substrate 3 as the accumulation time to be set in the substrate alignment measurement system 16, a decrease in measurement accuracy can be suppressed. Similarly, when the structure from the mirror 7 provided on the original stage 2 to the original plate 1 is vibrating, by setting an integer multiple of the natural period of such vibration as the accumulation time to be set in the original plate alignment measurement system 13, a decrease in measurement accuracy can be suppressed.

[0046] <Fourth Embodiment> The exposure apparatus EXA has various production processes. For example, there are processes that prioritize the accuracy (such as overlay accuracy) of the pattern formed on the substrate 3 and processes that prioritize productivity. Generally, it is difficult to achieve both device operation that prioritizes accuracy and device operation that prioritizes productivity. Therefore, in the exposure apparatus EXA, in the control unit 50, as a device mode, a first mode that prioritizes accuracy or a second mode that prioritizes productivity can be set, and the device is operated while switching between them.

[0047] Specifically, when setting the first mode as the device mode, as described above, the accumulation time to be set in the alignment measurement system is determined so that an integer multiple of the natural period of the vibration of the alignment measurement system is set as the accumulation time. On the other hand, when setting the second mode as the device mode, regardless of the natural period of the vibration of the alignment measurement system, the accumulation time to be set in the alignment measurement system is determined.

[0048] When setting the first mode as the device mode, determine the accumulation time to be set for the alignment measurement system so that the first integral multiple of the natural period of vibration of the alignment measurement system is set as the accumulation time. On the other hand, when setting the second mode as the device mode, determine the accumulation time to be set for the alignment measurement system so that the second integral multiple of the natural period of vibration of the alignment measurement system is set as the accumulation time. Note that the first integral multiple is a multiple smaller than the second integral multiple.

[0049] In this way, by determining the accumulation time to be set for the alignment measurement system according to the device mode, the accuracy can be improved in the first mode, and the productivity can be improved in the second mode. In other words, in one exposure apparatus EXA, it is possible to achieve both device operation that prioritizes accuracy and device operation that prioritizes productivity.

[0050] <Fifth Embodiment> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as devices (semiconductor elements, magnetic storage media, liquid crystal display elements, etc.). Such a manufacturing method includes a step of forming a pattern on a substrate using an exposure apparatus EXA, a step of processing the substrate on which the pattern is formed, and a step of manufacturing an article from the processed substrate. Further, such a manufacturing method may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing an article in the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the prior art.

[0051] The disclosure of this specification includes the following lithography apparatus, lithography method, and method for manufacturing an article.

[0052] (Item 1) A lithography apparatus for forming a pattern on a substrate via a reticle, a stage for holding the reticle or the substrate, An alignment measurement system that measures the position of the mark by accumulating and photoelectrically converting light from the mark provided on the stage, A control unit that controls the alignment measurement system, and has, The control unit, acquires information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement results of the position of the mark, and determines the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system based on the information. A lithography apparatus characterized by the above.

[0053] (Item 2) The information includes a function that approximately represents the relationship, The function includes a plurality of extreme points at which the degree of variation becomes a minimum value, The control unit determines the accumulation time to be set in the alignment measurement system in the process based on the plurality of extreme points. The lithography apparatus according to Item 1, characterized by the above.

[0054] (Item 3) The control unit determines, as the accumulation time to be set in the alignment measurement system in the process, an integer multiple of the accumulation time difference, which is the difference between a first extreme point and a second extreme point closest to the first extreme point among the plurality of extreme points. The lithography apparatus according to Item 2, characterized by the above.

[0055] (Item 4) When the control unit increases the accumulated light amount of the light from the mark accumulated by the alignment measurement system, the control unit determines the accumulation time to be set in the alignment measurement system in the process such that the accumulation time increases by an integer multiple of the accumulation time difference. The lithography apparatus according to Item 3 is characterized by the above.

[0056] (Item 5) The control unit sets, as the apparatus mode of the lithography apparatus, a first mode that prioritizes the accuracy of the pattern formed on the substrate or a second mode that prioritizes the productivity of forming the pattern on the substrate, when setting the first mode, determines, as the exposure time to be set in the alignment measurement system in the process, an integer multiple of the exposure time difference, which is the difference between a first minimum point and a second minimum point that is closest to the first minimum point among the plurality of minimum points, when setting the second mode, determines the exposure time to be set in the alignment measurement system in the process regardless of the exposure time difference, The lithography apparatus according to item 2, characterized in that.

[0057] (Item 6) The control unit sets, as the apparatus mode of the lithography apparatus, a first mode that prioritizes the accuracy of the pattern formed on the substrate or a second mode that prioritizes the productivity of forming the pattern on the substrate, when setting the first mode, determines, as the exposure time to be set in the alignment measurement system in the process, a first integer multiple of the exposure time difference, which is the difference between a first minimum point and a second minimum point that is closest to the first minimum point among the plurality of minimum points, when setting the second mode, determines, as the exposure time to be set in the alignment measurement system in the process, a second integer multiple of the exposure time difference, wherein the first integer multiple is an integer multiple smaller than the second integer multiple, The lithography apparatus according to item 2, characterized in that.

[0058] (Item 7) The lithography apparatus according to item 3 or 4, characterized in that the integer multiple includes from 1 to 5 times.

[0059] (Item 8) The control unit sets each of a plurality of accumulation times in the alignment measurement system, and acquires the information by measuring the position of the mark a plurality of times by the alignment measurement system in which each of the plurality of accumulation times is set. The lithography apparatus according to any one of Items 1 to 7, characterized in that.

[0060] (Item 9) The information includes a function that approximately represents the relationship. The control unit obtains the period of the accumulation time from the function, and determines an integer multiple of the period of the accumulation time as the accumulation time to be set in the alignment measurement system in the process. The lithography apparatus according to Item 1, characterized in that.

[0061] (Item 10) The control unit obtains the natural period of vibration of the alignment measurement system from the information, and determines an integer multiple of the natural period as the accumulation time to be set in the alignment measurement system in the process. The lithography apparatus according to Item 1, characterized in that.

[0062] (Item 11) The control unit obtains the natural period of vibration of the stage from the information, and determines an integer multiple of the natural period as the accumulation time to be set in the alignment measurement system in the process. The lithography apparatus according to Item 1, characterized in that.

[0063] (Item 12) A lithography apparatus for forming a pattern on a substrate via a reticle, A stage for holding the reticle or the substrate, An alignment measurement system that measures the position of the mark by accumulating and photoelectrically converting light from the mark provided on the stage, A control unit, And having, The control unit, As a device mode of the lithography apparatus, a first mode that prioritizes the accuracy of the pattern formed on the substrate or a second mode that prioritizes the productivity of forming the pattern on the substrate is set. According to the device mode, based on information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement results of the position of the mark, the accumulation time to be set in the alignment measurement system is determined in the process of measuring the position of the mark by the alignment measurement system. A lithography apparatus characterized by the above.

[0064] (Item 13) A lithography method in a lithography apparatus having a stage for holding a reticle or a substrate and an alignment measurement system for measuring the position of the mark by accumulating and photoelectrically converting light from the mark provided on the stage, and forming a pattern on the substrate via the reticle, A step of acquiring information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement results of the position of the mark; A step of determining the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system based on the information; A lithography method characterized by the above.

[0065] (Item 14) A step of forming a pattern on a substrate using the lithography apparatus according to any one of Items 1 to 12; A step of processing the substrate on which the pattern is formed in the above step; A step of manufacturing an article from the processed substrate; A method for manufacturing an article, characterized by including the above steps.

[0066] The invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the claims are appended to disclose the scope of the invention.

Explanation of Reference Numerals

[0067] EXA: Exposure apparatus 1: Original plate 2: Original plate stage 3: Substrate 4: Substrate stage 13: Original plate alignment measurement system 16: Substrate alignment measurement system 50: Control unit

Claims

1. A lithography apparatus for forming a pattern on a substrate via a reticle, comprising: a stage for holding the reticle or the substrate; an alignment measurement system that measures the position of the mark by accumulating light from the mark provided on the stage and performing photoelectric conversion; a control unit for controlling the alignment measurement system; wherein the control unit acquires information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement result of the position of the mark, and determines the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system based on the information. A lithography apparatus characterized by the above.

2. The information includes a function approximately representing the relationship, the function includes a plurality of extreme points at which the degree of variation is at a minimum value, and the control unit determines the accumulation time to be set in the alignment measurement system in the process based on the plurality of extreme points. The lithography apparatus according to claim 1, characterized by the above.

3. The control unit determines, as the accumulation time to be set in the alignment measurement system in the process, an integer multiple of the accumulation time difference, which is the difference between a first extreme point and a second extreme point closest to the first extreme point among the plurality of extreme points. The lithography apparatus according to claim 2, characterized by the above.

4. When the control unit increases the accumulated light amount of the light from the mark accumulated in the alignment measurement system, the control unit determines the accumulation time to be set in the alignment measurement system in the process such that the accumulation time increases by an integer multiple of the accumulation time difference. The lithography apparatus according to claim 3, characterized by the above.

5. The control unit sets, as the apparatus mode of the lithography apparatus, a first mode that prioritizes the accuracy of the pattern formed on the substrate or a second mode that prioritizes the productivity of forming the pattern on the substrate. When setting the first mode, the control unit determines, as the accumulation time to be set in the alignment measurement system in the process, an integer multiple of the accumulation time difference, which is the difference between a first extreme point and a second extreme point closest to the first extreme point among the plurality of extreme points. When setting the second mode, regardless of the accumulation time difference, determine the accumulation time to be set in the alignment measurement system in the process. The lithography apparatus according to claim 2, characterized in that.

6. The control unit is As the apparatus mode of the lithography apparatus, set a first mode that prioritizes the accuracy of the pattern formed on the substrate, or a second mode that prioritizes the productivity of forming the pattern on the substrate. When setting the first mode, among the plurality of minimum points, determine, as the accumulation time to be set in the alignment measurement system in the process, the first integer multiple of the accumulation time difference, which is the difference between the first minimum point and the second minimum point closest to the first minimum point. When setting the second mode, determine, as the accumulation time to be set in the alignment measurement system in the process, the second integer multiple of the accumulation time difference. The first integer multiple is an integer multiple smaller than the second integer multiple. The lithography apparatus according to claim 2, characterized in that.

7. The integer multiple includes 1 to 5 times. The lithography apparatus according to claim 3, characterized in that.

8. The control unit sets each of a plurality of accumulation times in the alignment measurement system, and acquires the information by measuring the position of the mark a plurality of times by the alignment measurement system in which each of the plurality of accumulation times is set. The lithography apparatus according to claim 1, characterized in that.

9. The information includes a function that approximately represents the relationship. The control unit obtains the period of the accumulation time from the function, and determines, as the accumulation time to be set in the alignment measurement system in the process, the integer multiple of the period of the accumulation time. The lithography apparatus according to claim 1, characterized in that.

10. The control unit obtains the natural period of the vibration of the alignment measurement system from the information, and determines, as the accumulation time to be set in the alignment measurement system in the process, the integer multiple of the natural period. The lithography apparatus according to claim 1, characterized in that.

11. The control unit obtains the natural period of the vibration of the stage from the information, and determines, as the accumulation time to be set in the alignment measurement system in the process, the integer multiple of the natural period. The lithography apparatus according to claim 1, characterized in that.

12. A lithography apparatus for forming a pattern on a substrate via a reticle, a stage for holding the reticle or the substrate, an alignment measurement system that measures the position of the mark by accumulating light from the mark provided on the stage and performing photoelectric conversion, a control unit, and having, wherein the control unit, as a device mode of the lithography apparatus, sets a first mode that prioritizes the accuracy of the pattern to be formed on the substrate, or a second mode that prioritizes the productivity of forming the pattern on the substrate, and according to the device mode, based on information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement result of the position of the mark, determines the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system, a lithography apparatus characterized by the above.

13. A lithography method in a lithography apparatus for forming a pattern on a substrate via a reticle, the lithography apparatus having a stage for holding the reticle or the substrate and an alignment measurement system that measures the position of the mark by accumulating light from the mark provided on the stage and performing photoelectric conversion, a step of obtaining information indicating the relationship between the accumulation time for accumulating light from the mark in the alignment measurement system and the degree of variation in the measurement result of the position of the mark, a step of determining the accumulation time to be set in the alignment measurement system in the process of measuring the position of the mark by the alignment measurement system based on the information, a lithography method characterized by the above.

14. A step of forming a pattern on a substrate using the lithography apparatus according to claim 1, a step of processing the substrate on which the pattern is formed in the above step, a step of manufacturing an article from the processed substrate, a method for manufacturing an article, characterized by the above.

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