Substrate treatment method, substrate treatment apparatus, and production method of article

Abstract

To provide a technique advantageous for both of highly accurate positioning and high throughput.SOLUTION: A substrate treatment method includes: a pre alignment process of performing pre alignment of a substrate; and a fine alignment process of performing fine alignment of the substrate after the pre alignment process, where the pre alignment process includes a calculation process of calculating a positional deviation value according to a plurality of respective methods, and the fine alignment process includes a determination process of determining a detection range of a mark formed on the substrate based on the calculated plurality of positional deviation values.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method, a substrate processing apparatus, and an article manufacturing method. [Background technology]

[0002] In semiconductor manufacturing equipment, substrates are positioned (aligned) prior to substrate processing (e.g., exposure processing, inspection processing). One of the steps for this positioning is called pre-alignment (rough positioning). This step roughly aligns the substrate before processing on the substrate stage so that the amount of positional deviation of the substrate transported and placed on the substrate stage falls within a predetermined range.

[0003] In an exposure apparatus, pre-alignment is performed to position a substrate that has not yet undergone a lithography process (exposure process) and to determine the position of a pattern to be formed (the base pattern when the next exposure process is performed). Pre-alignment is also performed to position a substrate that has already undergone one or more exposure processes and has formed marks for substrate position measurement, in advance, so that it can be sent into the field of view of a measurement device such as an image processing device that positions the substrate with the high precision required in the exposure process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5895332 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional techniques, the pre-alignment accuracy can be reduced if the detection accuracy of the substrate outline is low or if there is an error in bonding the laminated substrates. When the pre-alignment accuracy is reduced, the alignment mark formed on the substrate may not be within the field of view of the measurement device when the substrate is placed on the stage. In this case, a search must be performed to bring the alignment mark within the field of view of the measurement device, reducing throughput.

[0006] The present invention provides a technique that is advantageous in achieving both high-precision alignment and high throughput. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a substrate processing method comprising: a pre-alignment process for pre-aligning a substrate; and a fine alignment process for fine-aligning the substrate after the pre-alignment process, wherein the pre-alignment process includes a calculation process for calculating a positional deviation amount according to each of a plurality of techniques; and the fine alignment process includes a determination process for determining a detection range of a mark formed on the substrate based on the calculated positional deviation amounts. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technique that is advantageous in achieving both high-precision alignment and high throughput. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of a substrate processing apparatus. [Figure 2] FIG. 2 is a diagram showing the configuration of a pre-alignment unit. [Figure 3] FIG. 10 is a diagram showing an example of an output waveform of a light receiving element with respect to a silicon substrate. [Figure 4] 10A and 10B are diagrams showing examples of output waveforms of a light receiving element for a chamfered transparent substrate. [Figure 5] 10A and 10B are diagrams showing examples of output waveforms of a light receiving element for a bonded substrate; [Figure 6] 5 is a diagram illustrating an example of the relationship between the rotation angle of the substrate and the detected position of the edge of the substrate. [Figure 7] 10 is a flowchart showing a positioning method. [Figure 8] FIG. 10 is a diagram showing an example of a mark expected range. [Figure 9] FIG. 10 is a diagram showing an example of a detection range including multiple mark expected ranges. [Figure 10] FIG. 10 is a diagram showing an example of a mark detection implementation range. [Figure 11] FIG. 1 is a diagram showing the configuration of an exposure apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] Unless otherwise specified, in this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system, with the XY plane being a direction parallel to the holding surface on which the substrate stage (described below) holds the substrate. The directions parallel to the X, Y, and Z axes in the XYZ coordinate system are referred to as the X direction, Y direction, and Z direction, respectively, and rotation around the X axis, Y axis, and Z axis are referred to as θX, θY, and θZ, respectively. Control or drive about the X, Y, and Z axes refers to control or drive in a direction parallel to the X axis, Y axis, and Z axis, respectively. Control or drive about the θX, θY, and θZ axes refers to control or drive in a direction parallel to the X axis, Y axis, and Z axis, respectively. Position refers to information that can be determined based on coordinates of the X, Y, and Z axes, and orientation refers to information that can be determined by values ​​of the θX, θY, and θZ axes.

[0012] First Embodiment The configuration of a substrate processing apparatus 1 according to a first embodiment will be described with reference to Fig. 1. The substrate processing apparatus 1 shown in Fig. 1 includes a pre-alignment unit 100 that performs first-stage positioning (pre-alignment), a substrate transport mechanism 2 for transporting substrates, a processing unit 300 that processes the substrates, and a control device 40. The control device 40 controls the pre-alignment unit 100, the substrate transport mechanism 2, and the processing unit 300. The processing unit 300 can perform second-stage positioning (fine alignment) on the substrate that has been pre-aligned in the pre-alignment unit 100, prior to substrate processing. Therefore, the processing unit 300 may also be called a fine alignment unit.

[0013] The substrate 60 is transported to the pre-alignment unit 100 by a substrate transport robot (not shown). The pre-alignment unit 100 has a pre-alignment stage 110 and an outer shape detection device 120. The pre-alignment unit 100 performs a first stage of positioning of the substrate 60 using the pre-alignment stage 110 and the outer shape detection device 120. In this specification, "positioning" refers to aligning the substrate to a predetermined position at least in the translational and rotational directions.

[0014] After the substrate 60 has undergone first-stage positioning in the pre-alignment unit 100, it is transported to the processing unit 300 by the substrate transport mechanism 2. The processing unit 300 has a substrate stage 310 and a mark detector 320 (detection unit). The substrate stage 310 is a stage that holds and moves the substrate 60. Marks 7 for alignment are formed on the substrate 60. The mark detector 320 detects the marks 7 on the substrate. The substrate stage 310 is driven based on the detection result of the marks 7 to perform second-stage positioning, which positions the substrate 60 at a position for performing a predetermined process.

[0015] In this embodiment, the substrate 60 has a V-shaped or U-shaped notch 64 on its outer periphery to indicate the direction. The substrate 60 may have an orientation flat formed thereon instead of a notch. However, if a method of detecting the direction without relying on a notch or orientation flat is employed, the substrate may not have a notch or orientation flat formed thereon. Furthermore, in this embodiment, there are no particular limitations on the material, transparency, or presence or absence of bonding processing of the substrate.

[0016] Next, the configuration of the pre-alignment unit 100 will be described with reference to Fig. 2. Fig. 2 is a side view of the pre-alignment unit 100 with the substrate 60 transported onto the pre-alignment stage 110. Before transporting the substrate 60 to the substrate stage 310 where second-stage positioning and predetermined processing are performed, the pre-alignment unit 100 detects the position of the substrate 60 and positions the substrate 60 at a predetermined waiting position based on the detection result.

[0017] The pre-alignment stage 110 can include a rotation stage 111 that rotates the substrate 60 in the θZ direction, an XY stage 112 that translates the substrate 60 within the XY plane, and a support 113 that supports the substrate 60.

[0018] The outer diameter detection device 120 may include a light source 121 arranged on the back side of the substrate 60. The outer diameter detection device 120 may further include an optical system 122 and a light receiving element 123 arranged above the light source 121 and on the front side of the substrate 60. The light source 121 is, for example, an LED light source. The light receiving element 123 is, for example, an imaging element such as a CCD or CMOS. The light source 122 emits light so that the illumination range includes at least an edge 61, which is the boundary between the substrate 60 and the space around its periphery. The light receiving element 123 receives light from the light source 121 that has passed through the space outside the substrate 60 (a space not blocked by the substrate 60) via the optical system 122. Furthermore, if the substrate 60 is a transparent substrate, the light receiving element 123 receives light that has passed through the space outside the substrate 60 and light that has transmitted through the substrate 60.

[0019] It is preferable that the light source 121 is bright-field illumination. By using bright-field illumination rather than dark-field illumination, even if a chamfer 62 is formed near the edge 61 of the substrate 60 to remove the corners, it is possible to prevent a decrease in the measurement accuracy of the edge 61 due to the influence of reflected light from the chamfer 62.

[0020] The control device 40 may include a control unit 41 and a storage unit 42. The control unit 41 may be configured, for example, by a computer (information processing device) having a processor such as a CPU (Central Processing Unit) and a memory. The control device 40 is connected to the light receiving element 123. The control unit 41 is configured to detect the edge 61 of the substrate from the light receiving result by the light receiving element 123 and perform calculations to determine the position of the substrate 60. The control device 40 is also connected to the light source 121 and can adjust the light source 121. The control device 40 is also connected to the pre-alignment stage 110 and controls the driving of the rotation stage 111 and the XY stage 112.

[0021] The memory unit 42 of the control device 40 stores information necessary for the alignment operation. For example, the position of the substrate 60 (including the position in the rotational direction) determined by the control unit 41, the light intensity of the light source 121, etc. may be stored. The control device 40 may have a plurality of control units 41 and memory units 42. When there are a plurality of control units and memory units, they may be integrated into a single housing, or may be distributed across multiple locations as long as their functionality is not impaired.

[0022] 3 to 5, the detection of the outer shape of the substrate by the control unit 41 will be described in detail. Fig. 3 shows the relationship between the output waveform (received light waveform 1600) of the light receiving element 123, which is information on the outer shape of the substrate when the outer shape (edge) of the substrate is present in the field of view of the light receiving element 123, and the substrate 600. The horizontal axis represents the radial position R of the substrate 600, and the vertical axis represents the amount of received light.

[0023] If the substrate 600 shown in Fig. 3 is a non-light-transmitting substrate such as a silicon substrate, the light from the light source 121 is blocked at the substrate edge 601, resulting in a received light waveform 1600 as shown in Fig. 3. If the substrate 610 shown in Fig. 4 is a light-transmitting substrate such as a glass substrate that is chamfered, the light from the light source 121 is blocked at the substrate edge 611, and then the light that has passed through the substrate 610 is received, resulting in a received light waveform 1610 as shown in Fig. 4. Also, as shown in Fig. 5, in the case of a substrate in which a silicon substrate 621 is bonded onto a glass substrate 620 (hereinafter referred to as a "bonded substrate"), the light from the light source 121 is blocked at the edge 622 of the glass substrate 620, and then the light that has passed through the glass substrate 620 is received, and then the light from the light source 121 is blocked again at the edge 623 of the silicon substrate 621. Therefore, the received light waveform 1620 as shown in Fig. 5 is obtained. In this way, the received light waveform changes depending on whether the substrate is transparent or opaque, whether it has been subjected to bonding processing, and so on.

[0024] Based on the above findings, a method for detecting the edge of a substrate will be described. In one example of the edge detection method, based on the received light waveform 1600 of the silicon substrate (substrate 600) shown in FIG. 3, a point 1601 where the light intensity first changes may be determined as an edge. Alternatively, a point 1603 where the change in light intensity subsides may be determined as an edge. Furthermore, a midpoint 1602 between points 1601 and 1603 may be determined as an edge. Also, in FIG. 5, a point 1622 where the light intensity first falls below a predetermined threshold value 1621 may be determined as an edge. Alternatively, a point 1624 where the light intensity falls below threshold value 1623 for the second time may be determined as an edge. By using such a method, it is possible to separately detect the outlines of each substrate constituting a bonded substrate from a single received light waveform. The edge detection method is not limited to the above and may be any method.

[0025] The control unit 41 applies edge detection to the entire outer periphery (entire rotation angle) of the substrate, thereby obtaining a position waveform 51 indicating the position of the substrate periphery and a notch shape 52, as shown in FIG. 6. In FIG. 6, the horizontal axis represents the substrate rotation angle θ (rotation angle in the θZ direction), and the vertical axis represents the detected edge position R of the substrate 60. A steep change point 52 on the graph corresponds to a notch 64 on the substrate. The deviation amount (Δθ) of the rotation angle of the substrate 60 can be calculated based on this steep change point 52. Furthermore, the eccentricity amount (ΔXY) of the center of the substrate 60 relative to the rotation center (origin) of the rotation stage 111 can be calculated based on the amplitude of the position waveform 51. Hereinafter, Δθ and ΔXY are referred to as "positional deviation amount." The positional deviation amount can include information on the rotation amount (Δθ) and the translation amount (ΔXY). Since Δθ and ΔXY are the amounts to be adjusted (compensated) by pre-alignment with respect to the rotation angle and the central position, respectively, Δθ and ΔXY may also be called "pre-alignment adjustment amounts."

[0026] Next, a positioning method (substrate processing method) in the substrate processing apparatus 1 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing a flow of alignment of the substrate 60 using the substrate processing apparatus 1. S1001 to S1007 are pre-alignment steps, and S1008 to S1013 are fine alignment steps.

[0027] In S1001, the control unit 41 dims the light source 121. It is preferable that the light source 121 be dimmed when the substrate 60, which acts as a light-blocking object, is not present in the substrate processing apparatus 1. If the light source 121 is dimmed when the substrate 60 is present on the optical path, the amount of light in the portion blocked by the substrate 60 cannot be confirmed, and there is a risk that the signal strength will exceed the allowable value during the rotation of the substrate 60.

[0028] In S1002, the control unit 41 controls the transfer robot (not shown) to load the substrate 60 into the pre-alignment unit 100. The loaded substrate 60 is placed on the support unit 113 and fixed onto the support unit 113 by a vacuum suction mechanism (not shown). At this stage, the substrate 60 has not been aligned, and therefore is misaligned in the translational and rotational directions from the desired position.

[0029] In S1003, the control unit 41 controls the rotation stage 111 to rotate the substrate 60. While the rotation stage 111 is rotating, the light receiving element 123 receives light from the light source 121. In S1004, the control unit 41 sequentially acquires the output of the light receiving element 123 and stores it in the memory unit 42. After the control unit 41 has rotated the substrate 60 by the amount required for alignment (360°), it terminates the rotation operation by the rotation stage 111 (S1005). As a result, the output of the light receiving element 123 for each rotation angle of the substrate 60 is acquired, and a received light waveform, which is external shape information of the substrate 60, is obtained.

[0030] In S1006 (calculation step), the control unit 41 performs edge detection on the substrate 60 using a plurality of methods for the received light waveform for one circumference, and obtains the positional deviation amounts (Δθ and ΔXY) calculated according to each of the plurality of methods. Here, the plurality of methods may, for example, have different criteria for determining which part of the received light waveform is an edge. Alternatively, the plurality of methods may, for example, have the same edge determination method but different threshold values. Alternatively, the plurality of methods may differ from each other in whether or not pre-processing for noise removal is performed on the received light waveform, or the content of the pre-processing may differ from each other. The specific edge detection method for each of the plurality of methods and the classification criteria for the plurality of methods are arbitrary.

[0031] In S1007, the control unit 41 performs first-stage positioning of the substrate 60 based on one of the multiple positional deviation amounts (Δθ and ΔXY) obtained in S1006. The first-stage positioning is performed by rotating (θ direction) and horizontally moving (XY directions) the substrate holding mechanism 113 using the rotation stage 111 and the XY stage 112. The first-stage positioning is also performed by controlling the rotation stage 111 and the XY stage 112 so that the center of the substrate 60 is located at a target position such as the origin of the pre-alignment stage 110. In S1008, the control unit 41 controls the substrate transport mechanism 2 to transport the pre-aligned substrate 60 to the substrate stage 310 of the processing unit 300.

[0032] Next, second-stage positioning (fine alignment) is performed. In the second-stage positioning, it is necessary to detect the mark 7 on the substrate 60. To detect the mark 7 on the substrate 60, the control unit 41 determines the detection range of the mark 7 in S1009 (determination step). Here, the design position and size of the mark 7 on the substrate 60 are known. The control unit 41 calculates multiple candidates for the location of the mark 7 (mark position candidates) based on the design position of the mark 7 and the multiple misalignment amounts (Δθ and ΔXY) obtained in S1006, and determines an area including these multiple mark position candidates as the detection range. Note that the "detection range" may include information about the position and size on the substrate where detection by the mark detector 320 is performed. Because the field of view of the mark detector 320 is larger than the size of the mark 7, the size of the field of view of the mark detector 320 becomes the "detection range." In this case, the "detection range" can be set to any width. For example, an area including the vicinity of the mark 7 may be set as the "detection range" taking into account errors.

[0033] In S1010, the control unit 41 performs XY drive of the substrate stage 310 (positioning of the substrate) based on the determined detection range (for example, so that the detection range or a part of it falls within the field of view of the mark detector 320). The XY drive of the substrate stage 310 is performed, for example, so that detection is performed with priority given to a position calculated to contain the mark 7 within the region determined as the detection range. In S1011, the control unit 41 detects the mark 7 on the substrate 60 using the mark detector 320 (scope).

[0034] In S1012, the control unit 41 determines whether mark detection was successful. If mark detection was successful (YES in S1012), the process proceeds to S1013. In S1013, the control unit 41 calculates errors in translation (ΔXY) and rotation (Δθ) relative to the target position of the substrate 60 from the mark detection result using the mark detector 320. Thereafter, the control unit 41 rotates (θ direction) and moves horizontally (XY directions) the substrate stage 310 based on the calculated errors, thereby finally positioning the substrate 60 to the desired position.

[0035] In S1011, even if the mark 7 on the substrate 60 placed on the substrate stage 310 is observed by the mark detector 320, the mark 7 may be outside the field of view of the mark detector 320 (NO in S1012). Typically, when determining the center of a substrate, calculations are performed assuming that the portion other than the notch or orientation flat is circular and that the substrate size conforms to a standard. However, in reality, even excluding the notch or orientation flat, the substrate is not circular but has a distorted shape. Furthermore, even for a 12-inch substrate, for example, there is variation in substrate size on the order of several hundred microns within a lot. Furthermore, the accuracy of the obtained outline data varies depending on the type of substrate and the edge detection method used for that substrate. In addition, in the case of a substrate in which a silicon substrate 621 is bonded to a glass substrate 620 as shown in FIG. 5, bonding errors between the substrates can also cause the mark 7 to not be within the field of view of the mark detector 320. In the case of such a bonded substrate, it is desirable to perform pre-alignment by detecting the edge 623 of the surface on which the mark 7 is formed (in this case, the silicon substrate 621). However, in such bonded substrates, foreign matter may be attached to the glass substrate 620 or the adhesive used for bonding may protrude, making it impossible to accurately detect the edge 623. In such a situation, the accuracy of the substrate position calculated based on the edge 623 may also be reduced. Alternatively, it may not be possible to perform edge detection with the accuracy required to calculate the substrate position in the first place. Therefore, in such a situation, pre-alignment may be performed using the edge 622 of the glass substrate. In this case, if there is a bonding error between the substrates, the mark 7 may not be within the field of view of the mark detector 320 when performing the second-stage positioning.

[0036] If mark detection fails, for example, if it is determined that the mark 7 is outside the field of view of the mark detector 320 (NO in S1012), the process proceeds to S1014. In S1014, the control unit 41 determines whether or not there is an area within the detection range determined in S1009 where mark detection has not yet been attempted. If there is an area within the detection range determined in S1009 where mark detection has not yet been attempted (YES in S1014), the process returns to S1010. In S1010, the control unit 41 drives the substrate stage 310 in the XY directions so that the area where mark detection has not yet been attempted is brought into the field of view of the mark detector 320. Then, in S1011, the control unit 41 performs mark detection again.

[0037] In S1014, if mark detection has already been performed in the entire detection range and there is no area where mark detection has not been attempted (NO in S1014), the process proceeds to S1015. In S1015, the control unit 41 expands the range where mark detection is performed to the periphery of the detection range and searches for the mark 7. The search for the mark 7 is a process in which mark detection is attempted using the mark detector 320 in the vicinity of the area set in S1009. The control unit 41 drives the substrate stage 310 in the XY directions so that areas where mark detection has not yet been performed in the vicinity of the area set in S1009 come into the field of view of the mark detector 320, and then performs mark detection again in S1011. If mark 7 detection is not successful even after repeating the mark detection process a desired number of times and within a desired range, it may determine that the positioning process cannot be continued and abort the process for that substrate.

[0038] An example of positioning in the first embodiment will be described. In S1006, the control unit 41 uses multiple (here, two) edge detection methods to detect edge A and edge B. It is assumed that the two calculated positional deviation amounts are ΔXY_A, ΔθA, and ΔXY_B, ΔθB, respectively.

[0039] In S1007, the control unit 41 performs the first stage positioning using, for example, edge A. In this case, specifically, the parallel movement mechanism 112 of the pre-alignment stage 110 is translated by −ΔXY_A to align the center of the substrate 60 with the central coordinates of the pre-alignment stage 110. Thereafter, the rotation stage 111 is rotated by −ΔθA to align the notch 64 of the substrate 60 with a predetermined direction.

[0040] In S1008, the control unit 41 transports the substrate 60 for which the first-stage positioning has been completed, using the substrate transport mechanism 2. At this time, the substrate 60 is placed on the substrate stage 310 so that the center of the substrate stage 310 of the second substrate processing apparatus 300 coincides with the center of the substrate 60 and so that the angle of the notch 64 does not change.

[0041] In S1009, the control unit 41 determines the mark detection range. Here, it is assumed that the position M of the mark 7 formed on the substrate 60 (the position when the center of the substrate is the origin) is known. At this time, the first-stage positioning with reference to the position of edge A has been completed, and the center of the substrate 60 and the center of the substrate stage 310 coincide. Therefore, in a two-dimensional coordinate system with the center of the substrate stage 310 as the origin, the position T_A where the mark 7 is expected to exist coincides with the position M of the mark 7. Meanwhile, in this state, with reference to edge B, the position T_B where the mark 7 is expected to exist in a two-dimensional coordinate system with the center of the substrate stage 310 as the origin can be expressed by the following equation (1) using ΔXY_A, ΔθA and ΔXY_B, ΔθB.

[0042] T_B(x,y)=R(ΔθB-ΔθA)(ΔXY_B-ΔXY_A) (1) however,

[0043]

number

[0044] The control unit 41 determines the mark detection range so as to include at least the expected mark positions T_A and T_B calculated based on the positional deviation amounts determined from edge A and edge B, respectively. In practice, the control unit 41 sets expected mark ranges 81a and 81b, which are ranges where marks are expected to exist, so as to include at least a range covering an area the size of the mark 7. In FIG. 8, the sizes of the expected mark ranges 81a and 81b each match the size of the mark 7. In FIG. 8, the expected mark ranges 81a and 81b are each set to a minimum size, but as shown in FIG. 9, a detection range may also be set that includes a neighborhood 82 of the expected mark ranges 81a and 81b.

[0045] In S1010, the control unit 41 translates the substrate stage 310 so that the determined mark expected range 81 (81a or 81b) falls within the field of view of the mark detector 320. Here, the processing when the mark expected range 81a falls within the field of view of the mark detector 320 will be described. After the movement of the substrate stage 310 is completed in S1010, the control unit 41 performs mark detection in S1011. Here, as shown in FIG. 10 , the control unit 41 performs mark detection within a mark detection implementation range 9. The mark detection implementation range 9 is a range that matches the size of the field of view of the mark detector 320.

[0046] In S1012, the control unit 41 determines whether or not a mark was present within the mark detection implementation range 9. A case will be described where it is determined in S1012 that a mark was not present within the mark detection implementation range 9. If mark detection has failed, in S1014 the control unit 41 checks whether or not there is an area where mark detection has not yet been performed. In the example of FIG. 10, the mark expected range 81a is included in the mark detection implementation range 9, and is an area where detection has already been performed. On the other hand, mark detection has not yet been performed in the mark expected range 81b, so in this case the processing returns to S1010.

[0047] In S1010, the control unit 41 drives the substrate stage 310 so that the undetected mark expected range 81b is within the field of view of the mark detector 320, and continues the subsequent processing. If mark detection fails again in S1012, the processing returns to S1014. However, mark detection has already been performed for the mark expected ranges 81a and 81b. Therefore, in this case, the processing proceeds to S1015. In S1015, the control unit 41 repeats the substrate stage driving and mark detection steps S1011 to S1015 to attempt mark detection for the nearby region 82. If mark detection is unsuccessful even after performing mark detection for the entire nearby region 82, or if mark detection is unsuccessful even after repeated a predetermined number of times, the positioning processing for the substrate may be deemed to have failed, and the processing may be interrupted.

[0048] According to the positioning method described above, when the alignment mark is not within the field of view of the measurement device, the time required for mark detection can be reduced, thereby achieving both high-precision alignment and high throughput.

[0049] Second Embodiment Next, a positioning method according to the second embodiment will be described. The difference from the first embodiment is the method for determining the mark detection position and range in S1009. The same reference numerals are used for other similar components, and their description will be omitted. The configuration of the alignment device in this embodiment is also the same as that shown in FIG. 1, so its description will be omitted.

[0050] In S1009 of the first embodiment, multiple candidates for the position where the mark 7 is theoretically located (candidate mark positions) are calculated based on the theoretical position of the mark 7 and the multiple misalignment amounts (Δθ and ΔXY) obtained in S1006. Then, an area including the candidate mark positions is determined as the detection range. However, the multiple misalignment amounts obtained in S1006 may include low-accuracy positions calculated from low-accuracy edge detection results. For example, in a substrate in which a silicon substrate 621 is bonded to a glass substrate 620 shown in FIG. 5, foreign matter may be attached to the glass substrate 620 or adhesive used for bonding may protrude. In this case, when the misalignment amount is calculated based on the edge 623 shown in FIG. 5, an unrealistic misalignment amount (Δθ and ΔXY) may be calculated. If an area including the candidate mark positions calculated based on such misalignment amounts is determined as the mark detection range, an area where no marks should exist will be measured unnecessarily.

[0051] Therefore, in the second embodiment, this situation is addressed by setting a certain standard when calculating the mark candidate position from the calculated misalignment amounts (Δθ and ΔXY). This certain standard can be, for example, a standard value for substrate size or a standard value (or actual value) of the bonding error in the case of a bonded substrate. In the case of a bonded substrate, the maximum possible translation and rotation errors (maximum errors) of the position of the mark 7 due to the bonding error can be calculated for each of Δθ and ΔXY from the standard value of the bonding error and the position of the mark 7 on the substrate. For example, when the misalignment amount calculated from the edge of the bonded substrate (e.g., the edge of the glass substrate) is used as the reference, the misalignment amount calculated from another edge (e.g., the edge of the silicon substrate) may differ by more than the theoretical maximum error. In this case, the misalignment amount calculated from the edge of the silicon substrate is corrected based on the maximum error. For example, when the position calculated from the edge of the glass substrate is used as the reference, the translation (ΔXY) of the position calculated from the edge of the silicon substrate may be expressed as a vector, and the magnitude of the vector may be reduced to the same as the maximum error while maintaining the direction of the vector. This means that only the direction of the expected mark position is used to determine the mark detection position. Also, if the translation error is greater than or equal to the maximum error but the rotation error is within the maximum error, the translation may not be taken into account (assuming that there is no translation component in the stitching error) and the mark candidate position may be calculated using only the rotation error. The method of correction based on the maximum error is arbitrary.

[0052] According to this embodiment, by using information on the amount of positional deviation with low detection accuracy in a limited manner, it is possible to prevent unnecessary mark detection operations, and to improve productivity compared to the first embodiment.

[0053] Third Embodiment Next, a positioning method according to the third embodiment will be described. The difference from the first embodiment is that it specifies which position and range of the mark detection positions and ranges determined in S1009 are to be given priority for mark detection. Specifically, in S1010 and S1015, the substrate stage 310 is driven to the area where mark detection is to be given priority. Other similar components are given the same reference numerals and their description will be omitted. Furthermore, the configuration of the alignment device in this embodiment is the same as that shown in FIG. 1, and therefore its description will be omitted.

[0054] In the first embodiment, of the mark detection positions and ranges determined in S1009, the position where a mark is mathematically present is given priority. However, if there are multiple positions where a mark is mathematically present, it is not specified which of those positions is given priority. If there are multiple positions where the mark is mathematically present, multiple driving of the substrate stage 310 and multiple mark detections are required to complete mark detection for all of that area. If mark detection is successful even once, it is possible to proceed to the next step, but the more mark detections are performed, the longer it takes, which is detrimental to the productivity of the substrate processing apparatus. Therefore, it is specified which position and range is given priority for mark detection among the determined mark detection positions and ranges, so that mark detection can be completed with fewer mark detections.

[0055] Prioritizing a candidate mark position among the multiple calculated candidate mark positions is determined by calculating an accuracy evaluation value for each of the multiple misalignment amounts used to calculate the candidate mark positions and determining the candidate position based on the accuracy evaluation value. The higher the accuracy evaluation value, the higher the expected first-stage alignment accuracy, and therefore the higher the expected probability that the mark 7 will be within the field of view of the detector 320. For example, the accuracy evaluation value of the misalignment amount is calculated from the accuracy evaluation value of the outer shape (received light waveform) of the substrate used to calculate that misalignment amount. The size and notch shape of the substrate to be processed are specified by standards, and the ideal shape is known. Therefore, the measurement accuracy can be calculated from the difference between the ideal shape of the substrate and the actually measured received light waveform. Furthermore, if three or more edge detection methods are used to calculate three or more misalignment amounts, the center of gravity of the substrate center positions may be calculated, and the evaluation value may be set higher for positions closer to the center of gravity. Alternatively, the measurement accuracy evaluation value may be calculated using any method or a combination of methods.

[0056] According to this embodiment, by preferentially detecting the mark detection position calculated from the positional deviation amount with high detection accuracy, it is expected that the total time required for mark detection will be shortened, and productivity can be improved compared to the first embodiment.

[0057] <Fourth embodiment> Next, an alignment method according to the fourth embodiment will be described. The difference from the first embodiment is that in S1009 for the second and subsequent substrates, the calculation method or calculation conditions for the mark detection position and range are changed. The calculation method or calculation conditions are changed based on the position error calculated to measure the mark 7 in S1011 of the second-stage alignment and perform alignment in S1013. Other similar components are given the same reference numerals and their description will be omitted. Furthermore, the configuration of the alignment device in this embodiment is the same as the configuration shown in FIG. 1, so its description will be omitted.

[0058] Generally, when pre-alignment (first-stage positioning) is performed by detecting the outer shape of the substrate, and then second-stage positioning is performed by detecting marks on the substrate, the second-stage positioning is more accurate than pre-alignment. In other words, the position finally achieved in the second-stage positioning is also the final target position to be aimed for in pre-alignment. Here, the differences between the multiple positional deviations calculated during pre-alignment and the positions determined by mark detection in the second-stage positioning can be calculated. If it is assumed that the positional differences tend to be the same, for example, for each lot of substrates to be processed, the differences can be corrected in advance when determining the mark detection position and range from the positional deviations calculated during pre-alignment.

[0059] The flowchart of the alignment method according to the fourth embodiment is similar to the flowchart of the first embodiment shown in Fig. 7. In particular, in processing the first substrate, there is no difference in the processing up to S1013.

[0060] In S1013, the control unit 41 calculates the translation and rotation errors (ΔXY, Δθ) from the target position of the substrate 60 based on the detection result of the mark 7 by the mark detector 320. Then, the control unit 41 calculates the difference (correction offset) between the calculated error and each of the multiple positional deviation amounts calculated in the first-stage positioning, and stores the correction offset in the memory unit 42 for each edge detection method used to calculate each positional deviation amount. This correction offset is a value that, when further position correction by this correction offset is performed on each positional deviation amount calculated in the first-stage positioning, achieves positioning with the same accuracy as after the second-stage positioning. When processing the second or subsequent substrates, in S1009, the method for calculating the mark detection position and range is changed using the correction offset for each edge detection method stored in the memory unit 42. Specifically, when calculating the mark detection position, coordinates are calculated by adding the correction offset for the corresponding edge detection method. If the correction offset has a similar tendency for each substrate, the accuracy of determining the mark detection position calculated by taking this correction offset into account is improved, making it easier to avoid situations where the mark 7 does not fall within the field of view of the detector 320. However, if the correction offset has a tendency to vary from substrate to substrate, the accuracy of determining the mark detection position may be reduced. Therefore, the accuracy of the correction offset may be evaluated and a correction offset with low accuracy may be avoided. Assuming that the correction offset is exactly the same for each substrate, even if there are differences in the positional deviation amounts calculated for each edge detection method, the positional deviation amounts obtained by adding the correction offset to the positional deviation amount and further correcting it should be consistent for all methods. Conversely, a correction offset that does not result in a consistent position when performing the same correction can be determined to be a component that varies from substrate to substrate. Such a correction offset that has a component that varies from substrate to substrate may be excluded from use when calculating the mark detection position.

[0061] According to this embodiment, by using the highly accurate second-stage positioning results during subsequent substrate processing, the mark detection position can be determined with even greater accuracy than when the mark detection position is determined from information that can be obtained from the substrate alone.

[0062] The above-described embodiment is merely illustrative, and the present invention is not limited to the above-described configurations and shapes. Appropriate modifications and changes are possible within the scope of the present invention. For example, the first substrate processing apparatus may be configured with two or more outer shape detection devices, each of which may be of a different type. Different edge detection methods may be applied to the substrate outer shape information detected by each outer shape detection device.

[0063] <Embodiment of Lithography Apparatus> An embodiment in which the above-described substrate processing apparatus 1 is configured as a lithography apparatus will be described. A lithography apparatus is an apparatus employed in a lithography process, which is a manufacturing process for semiconductor devices and liquid crystal display devices, for forming a pattern on a substrate. An example of a lithography apparatus is an exposure apparatus that transfers a pattern of an original onto a substrate by exposing the substrate through an original. In the following description, an exposure apparatus will be used as an example of the lithography apparatus.

[0064] FIG. 11 is a diagram showing the configuration of a substrate processing apparatus 1 as an exposure apparatus. The substrate processing apparatus 1 as an exposure apparatus transfers a pattern of an original R onto a substrate 60, for example, by a step-and-repeat method or a step-and-scan method. As shown in FIG. 1, the substrate processing apparatus 1 has a pre-alignment unit 100, a substrate transport mechanism 2, a processing unit 300, and a control device 40. Here, the processing unit 300 is configured as a forming unit that forms a pattern on the substrate 60. Specifically, as shown in FIG. 11, the processing unit 300 may include an illumination optical system 201, an original stage 202, a projection optical system 203, a substrate stage 310, and a mark detector 320.

[0065] The pre-alignment section 100 performs pre-alignment of the substrate 60 in the same manner as in the first embodiment. That is, in the pre-alignment step, the pre-alignment section 100 calculates the amount of misalignment of the substrate 60 according to each of a plurality of methods.

[0066] The pre-aligned substrate 60 is transported onto the substrate stage 310 by the substrate transport mechanism 2. The control device 40 is configured to comprehensively control the control processes and exposure processes described in the first to fourth embodiments. Prior to the exposure process, the control device 40 performs fine alignment on the substrate 60 on the substrate stage 310. As described in the first embodiment, the fine alignment includes determining the detection range of the marks formed on the substrate 60 based on the multiple positional deviation amounts calculated in the pre-alignment process.

[0067] <Embodiment of an article manufacturing method> The above-described lithography apparatus can be used to implement an article manufacturing method for manufacturing various articles (such as semiconductor IC elements, liquid crystal display elements, and MEMS). The article manufacturing method according to the present embodiment is suitable for manufacturing articles such as devices (such as semiconductor elements, magnetic storage media, and liquid crystal display elements). The article manufacturing method includes a processing step of processing a substrate using the above-described substrate processing method (substrate processing apparatus), a formation step of forming a pattern on the substrate that has undergone the processing step, and a manufacturing step of manufacturing an article from the substrate that has undergone the formation step. The processing step may be understood as a step of performing pre-alignment processing as substrate processing. Furthermore, the article manufacturing method may include other well-known processes (such as oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, and packaging). The article manufacturing method according to the present embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost.

[0068] <Other embodiments> The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0069] The disclosure of the present specification includes at least the following techniques. (Item 1) a pre-alignment step of pre-aligning the substrate; a fine alignment step of performing fine alignment of the substrate after the pre-alignment step, the pre-alignment step includes a calculation step of calculating a positional deviation amount according to each of a plurality of methods; the fine alignment step includes a determination step of determining a detection range of a mark formed on the substrate based on the calculated plurality of positional deviation amounts. A substrate processing method comprising: (Item 2) the pre-alignment step includes a step of positioning the substrate based on one of the plurality of positional deviation amounts, The fine alignment step includes: positioning the substrate based on the detection range, and then detecting the mark using a scope; If the detection of the mark fails, moving the substrate so that the mark can be detected in a range of the detection range where the mark has not been detected, and then re-detecting the mark using the scope; 2. The substrate processing method according to item 1, comprising: (Item 3) 3. The substrate processing method according to item 2, wherein, in the fine alignment step, if detection of the mark fails and detection of the mark has already been performed in the entire detection range, the range in which detection of the mark is performed is expanded to the periphery of the detection range. (Item 4) 4. The substrate processing method according to any one of items 1 to 3, wherein in the determining step, a plurality of mark position candidates, which are candidates for the position of the mark, are calculated based on the design position of the mark and the plurality of positional deviation amounts, and an area including the plurality of mark position candidates is determined as the detection range. (Item 5) the displacement amount includes a translation amount and a rotation amount of the substrate, In the determining step, the detection range is determined based on a maximum possible error between the translation amount and the rotation amount. 5. The substrate processing method according to any one of items 1 to 4, wherein (Item 6) 4. The substrate processing method according to item 2 or 3, wherein in the fine alignment step, the detection of the mark is performed by giving priority to a range within the detection range in which the mark is theoretically present. (Item 7) 4. The substrate processing method according to item 2 or 3, wherein in the fine alignment step, an accuracy evaluation value is calculated for each of the plurality of positional deviation amounts, and the mark is detected by giving priority to a range of the detection range having a high accuracy evaluation value. (Item 8) 8. The substrate processing method according to any one of items 1 to 7, wherein a calculation method or calculation conditions for the detection range for a second substrate to be processed after the first substrate are changed based on the result of detection of the mark performed in the fine alignment process and the plurality of positional deviation amounts calculated in the pre-alignment process for the first substrate. (Item 9) a pre-alignment device that pre-aligns the substrate; a processing unit that processes the substrate that has been pre-aligned in the pre-alignment device, The processing unit a substrate stage that holds and moves the substrate; a detection unit that detects a mark formed on the substrate, the pre-alignment device calculates the amount of misalignment of the substrate according to each of a plurality of methods; the processing unit is configured to determine a detection range of the mark on the substrate held by the substrate stage by the detection unit based on the calculated plurality of positional deviation amounts. A substrate processing apparatus characterized by: (Item 10) the substrate processing apparatus is a lithography apparatus that forms a pattern on a substrate, The processing unit is configured as a forming unit that forms a pattern on the substrate. 10. The substrate processing apparatus according to item 9, (Item 11) A processing step of processing a substrate using the substrate processing method according to any one of items 1 to 8; a forming step of forming a pattern on the substrate that has undergone the processing step; a manufacturing process for manufacturing an article from the substrate that has undergone the forming process; A method for manufacturing an article, comprising:

[0070] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0071] 1: substrate processing apparatus, 2: substrate transport mechanism, 7: mark, 40: control device, 60: substrate, 100: pre-alignment unit, 300: processing unit, 310: substrate stage, 320: mark detector

Claims

1. a pre-alignment step of pre-aligning the substrate; a fine alignment step of performing fine alignment of the substrate after the pre-alignment step, the pre-alignment step includes a calculation step of calculating a positional deviation amount according to each of a plurality of methods; the fine alignment step includes a determination step of determining a detection range of a mark formed on the substrate based on the calculated plurality of positional deviation amounts. A substrate processing method comprising:

2. the pre-alignment step includes a step of positioning the substrate based on one of the plurality of positional deviation amounts, The fine alignment step includes: positioning the substrate based on the detection range, and then detecting the mark using a scope; If the detection of the mark fails, moving the substrate so that the mark can be detected in a range of the detection range where the mark has not been detected, and then re-detecting the mark using the scope; 2. The substrate processing method according to claim 1, further comprising:

3. 3. The substrate processing method according to claim 2, wherein, in the fine alignment process, if detection of the mark fails and detection of the mark has already been performed in the entire detection range, the range in which detection of the mark is performed is expanded to include the periphery of the detection range.

4. 2. The substrate processing method according to claim 1, wherein in the determining step, a plurality of mark position candidates, which are candidates for the position of the mark, are calculated based on the design position of the mark and the plurality of positional deviation amounts, and an area including the plurality of mark position candidates is determined as the detection range.

5. the displacement amount includes a translation amount and a rotation amount of the substrate, In the determining step, the detection range is determined based on a maximum possible error between the translation amount and the rotation amount.

2. The substrate processing method according to claim 1.

6. 3. The substrate processing method according to claim 2, wherein in the fine alignment step, priority is given to a range of the detection range in which the mark is theoretically present when detecting the mark.

7. 3. The substrate processing method according to claim 2, wherein in the fine alignment process, an accuracy evaluation value is calculated for each of the plurality of positional deviation amounts, and the mark is detected by giving priority to a range of the detection range having a high accuracy evaluation value.

8. 2. The substrate processing method according to claim 1, further comprising changing a calculation method or calculation conditions for the detection range for a second substrate to be processed after the first substrate, based on the result of detection of the mark performed in the fine alignment process for the first substrate and the multiple positional deviation amounts calculated in the pre-alignment process.

9. a pre-alignment device that pre-aligns the substrate; a processing unit that processes the substrate that has been pre-aligned in the pre-alignment device, The processing unit a substrate stage that holds and moves the substrate; a detection unit that detects a mark formed on the substrate, the pre-alignment device calculates the amount of misalignment of the substrate according to each of a plurality of methods; the processing unit is configured to determine a detection range of the mark on the substrate held by the substrate stage by the detection unit based on the calculated plurality of positional deviation amounts. A substrate processing apparatus comprising:

10. the substrate processing apparatus is a lithography apparatus that forms a pattern on a substrate, The processing unit is configured as a forming unit that forms a pattern on the substrate. The substrate processing apparatus according to claim 9 .

11. a processing step of processing a substrate using the substrate processing method according to any one of claims 1 to 8; a forming step of forming a pattern on the substrate that has undergone the processing step; a manufacturing process for manufacturing an article from the substrate that has undergone the forming process; A method for manufacturing an article, comprising:

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