Substrate processing method, substrate processing apparatus, lithography apparatus, and article manufacturing method

Abstract

This technology offers advantages in achieving both high throughput and detection accuracy when detecting the position of a substrate. [Solution] A substrate processing method for processing a substrate, comprising: a first measurement step of measuring the light intensity distribution obtained from the peripheral portion of the substrate when light from a light source is irradiated onto the peripheral portion of the substrate; and a identification step of identifying candidates for the peripheral position of the substrate based on the measurement results obtained in the first measurement step. In the substrate processing method, multiple types of measurement results are obtained by performing measurements using multiple types of measurement conditions in a single first measurement step, and candidates for the peripheral position of the substrate are identified from each of the multiple types of measurement results in the identification step.

Description

Technical Field

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

Background Art

[0002] In a lithography apparatus for forming a pattern on a substrate, before transporting the substrate onto a stage for holding the substrate, a process of detecting the position of the substrate (so-called pre-alignment process) is performed. In the pre-alignment process, by irradiating light on the peripheral portion of the substrate, the peripheral position of the substrate is detected, and based on the detected peripheral position of the substrate, the position (orientation and center-of-gravity position) of the substrate is determined. Thereby, the positioning of the substrate when transporting the substrate onto the stage can be controlled. Further, in the pre-alignment process, detection of a notch formed in the substrate may be performed.

[0003] Substrates on which the pre-alignment process is performed include a plurality of types such as a transparent substrate, an opaque substrate, and a substrate in which a plurality of members are bonded together. When the type of the substrate changes, the tendency of the light intensity distribution obtained from the peripheral portion of the substrate may change. Therefore, in order to accurately detect the position of the substrate even when the type of the substrate changes, parameters for determining the position of the substrate from the light intensity distribution may be selected according to the type of the substrate. In Patent Document 1, in the outer periphery measurement for detecting the peripheral portion of the substrate, a plurality of parameters are applied and parameters capable of detecting the peripheral portion are selected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, since multiple parameters are applied, it is necessary to repeatedly switch parameters and remeasure, which is disadvantageous in terms of throughput.

[0006] Therefore, the exemplary objective of the present invention is to provide a technology that is advantageous in that it achieves both throughput and detection accuracy when detecting the position of a substrate. [Means for solving the problem]

[0007] To achieve the above objective, a substrate processing method as one aspect of the present invention is a substrate processing method for processing a substrate, comprising: a first measurement step of measuring the light intensity distribution obtained from the peripheral portion when light from a light source is irradiated onto the peripheral portion of the substrate; and a identification step of identifying candidates for the peripheral position of the substrate based on the measurement results obtained in the first measurement step, wherein multiple types of measurement results are obtained by performing measurements using multiple types of measurement conditions in a single first measurement step, and the candidates are identified from each of the multiple types of measurement results in the identification step. [Effects of the Invention]

[0008] According to the present invention, for example, it is possible to provide a technology that is advantageous in that it can achieve both throughput and detection accuracy when detecting the position of a substrate. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of the configuration of a substrate processing apparatus. [Figure 2] This figure shows an example of detecting the peripheral position of a substrate. [Figure 3] This figure shows an example of detecting the peripheral position of a substrate. [Figure 4] This figure shows an example of detecting the peripheral position of a substrate. [Figure 5] This figure shows an example of detecting the peripheral position of a substrate. [Figure 6] This figure shows an example of detecting the peripheral position of a substrate. [Figure 7] This figure shows an example of a position waveform representing the outline of a substrate and an ideal position waveform. [Figure 8] This is a diagram to explain equation (1). [Figure 9] This is a flowchart showing the operation flow of the pre-alignment process in the first embodiment. [Figure 10] This diagram illustrates an example of a method for selecting optimal measurement conditions. [Figure 11] This diagram illustrates an example of a method for selecting optimal measurement conditions. [Figure 12] This diagram illustrates an example of a method for selecting optimal measurement conditions. [Figure 13] This is a flowchart showing the operation flow of the pre-alignment process in the second embodiment. [Figure 14] This is a flowchart showing the operation flow of the pre-alignment process in the third embodiment. [Figure 15] This figure shows an example of a notched waveform corresponding to a notch in the rule and an ideal notched waveform. [Figure 16] This is a flowchart showing the operation flow of the pre-alignment process in the fourth embodiment. [Figure 17] This is a schematic diagram showing an example of the configuration of an exposure apparatus. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] In this specification and the accompanying drawings, unless otherwise specified, directions are indicated in an XYZ coordinate system where the direction parallel to the holding surface for the substrate chuck 123 to hold the substrate, described later, is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X-direction, Y-direction, and Z-direction, respectively, and the rotations around the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively. Control or drive related to the X-axis, Y-axis, and Z-axis means control or drive related to the directions parallel to the X-axis, Y-axis, and Z-axis, respectively. Also, control or drive related to the θX-axis, θY-axis, and θZ-axis means control or drive related to the rotations around the axes parallel to the X-axis, Y-axis, and Z-axis, respectively. Further, the position is information that can be specified based on the coordinates of the X-axis, Y-axis, and Z-axis, and the orientation is information that can be specified by the values of the θX-axis, θY-axis, and θZ-axis.

[0012] <First Embodiment> The first embodiment according to the present invention will be described. FIG. 1 is a schematic diagram of a substrate processing apparatus 100 according to the first embodiment. The substrate processing apparatus 100 may include a light source unit 111, a substrate holding unit 120, a measurement unit 110, and a control unit 130. FIG. 1 shows a state where a substrate 10 is placed on the substrate holding unit 120.

[0013] The substrate processing apparatus 100 of the present embodiment is an apparatus that performs a process (so-called pre-alignment process) of detecting the position of the periphery 12 of the substrate 10 before transporting the substrate 10 onto the substrate stage of a lithography apparatus. In the pre-alignment process, the position of the periphery 12 of the substrate 10 is detected based on the light intensity distribution obtained from the peripheral portion 13 of the substrate 10 when the peripheral portion 13 of the substrate 10 is irradiated with light. By determining the orientation and the center position of the substrate 10 based on the position of the periphery 12 of the substrate 10 detected by such a pre-alignment process, it is possible to control the positioning of the substrate 10 when transporting the substrate 10 onto the substrate stage of the lithography apparatus. Note that the positioning of the substrate 10 means adjusting (arranging) the substrate 10 to a predetermined position and orientation with respect to the translational direction (for example, the XY direction) and the rotational direction (for example, the θZ direction), and may also be referred to as "alignment of the substrate 10". Further, the substrate processing apparatus 100 that performs the pre-alignment process may also be referred to as a "pre-alignment apparatus" or a "substrate alignment apparatus".

[0014] The substrate holding unit 120 is a mechanism that holds and drives the substrate 10, and may include a substrate chuck 123, a rotational drive unit 121, and a translational drive unit 122. The substrate chuck 123 holds the central portion of the substrate 10 with a holding surface parallel to the XY plane by a vacuum suction force, an electrostatic suction force, or the like. The rotational drive unit 121 rotationally drives the substrate 10 in the θZ direction by rotationally driving the substrate chuck 123 in the θZ direction with the Z axis as the rotation axis. The translational drive unit 122 translationally drives the substrate 10 in the XY direction by translationally driving the substrate chuck 123 and the rotational drive unit 121 in the XY direction.

[0015] In this embodiment, the substrate 10 held by the substrate holding portion 120 has a notch in its peripheral edge portion 13. The notch of the substrate 10 may be a notch or an orientation flat. However, the substrate 10 may be a substrate without a notch. Furthermore, the type of substrate 10 held by the substrate holding portion 120 and subjected to pre-alignment processing is arbitrary. That is, the substrate processing apparatus 100 of this embodiment is not limited by material, transparency, presence or absence of chamfering, presence or absence of bonding, etc., and can perform pre-alignment processing on various types of substrates 10.

[0016] The measurement unit 110 is a mechanism that measures the light intensity distribution obtained from the peripheral portion 13 of the substrate 10 when light is irradiated onto the peripheral portion 13, and may include a light source unit 111 and a light receiving unit 112 (light receiving element, light receiving sensor). The light source unit 111 is, for example, located on the back side (bottom side) of the substrate 10, and emits light toward the peripheral portion 13 such that the peripheral portion 13 of the substrate 10 is located in only a part of the optical path. As an example, an LED light source is used as the light source unit 111 here, but it may also be a laser light source or a fluorescent lamp.

[0017] Furthermore, the light-receiving unit 112 is positioned on the surface side (upper side) of the substrate 10, for example, facing the light source unit 111 (light emission surface), and receives light emitted from the light source unit 111. The light-receiving unit 112 in this embodiment includes a light-receiving element 112a (light-receiving sensor) and an optical system 112b. The light-receiving element 112a may be an image sensor such as a CCD image sensor or a CMOS image sensor. The optical system 112b is an imaging optical system for forming an image of the peripheral portion 13 of the substrate 10 onto the light-receiving surface (image-imaging surface) of the light-receiving element 112a.

[0018] If the substrate 10 is an opaque substrate, the light emitted from the light source unit 111 that passes through the space outside the substrate 10 is received by the light receiving unit 112. On the other hand, if the substrate 10 is a transparent substrate and the peripheral portion 13 is chamfered, the light emitted from the light source unit 111 that passes through the space outside the substrate 10 and the light that passes through the parts of the substrate 10 other than the peripheral portion 13 is received by the light receiving unit 112. The space outside the substrate 10 may be understood as the space that is not shielded by the substrate 10.

[0019] The measurement unit 110 measures the radial (X-direction) light intensity distribution obtained from a portion of the peripheral portion 13 of the substrate 10, based on the light received (detected) by the light receiving unit 112 from the light emitted from the light source unit 111. The measurement unit 110 then sequentially measures this radial light intensity distribution while the substrate 10 is rotated by the substrate holding unit 120. This allows the radial light intensity distribution to be obtained for the entire peripheral portion 13 of the substrate 10. In the following, the radial light intensity distribution may be simply referred to as "light intensity distribution".

[0020] Here, the measurement unit 110 in this embodiment is configured as a transmissive sensor, but is not limited to that. For example, it may be configured as a reflective sensor in which the light receiving unit 112 detects light reflected from the peripheral edge portion 13 of the substrate 10 out of the light emitted from the light source unit 111. Furthermore, it is preferable that the measurement unit 110 (light source unit 111) is bright-field illumination. By using bright-field illumination instead of dark-field illumination, even if the peripheral edge portion 13 of the substrate 10 is chamfered, it is possible to prevent a decrease in the detection accuracy of the position of the peripheral edge 12 of the substrate 10 due to the influence of reflected light from the chamfering process.

[0021] The control unit 130 may be composed of a computer (information processing device) having, for example, a processor 131 such as a CPU (Central Processing Unit) and a storage unit 133 such as memory. The control unit 130 is connected to each part of the substrate processing device 100 by a line and controls each part of the substrate processing device 100 (controls the pre-alignment process).

[0022] In this embodiment, one control unit 130 controls each part of the substrate processing apparatus 100, but the substrate processing apparatus 100 may have multiple control units. Specifically, it may include a first control unit that controls the measurement unit 110, a second control unit that controls the substrate holding unit 120, and a third control unit that performs processing such as detecting the position of the periphery 12 based on the measurement results. In this case, it is desirable that the first to third control units are connected to each other so as to be able to communicate with each other and send and receive information. For example, the control unit 130 can drive the substrate holding unit 120 to correct the misalignment of the substrate 10 determined by the third control unit, thereby aligning the substrate 10. Also, an external memory may be used as the storage unit 133.

[0023] In this embodiment, the control unit 130 (processor 131) detects the position of the periphery 12 of the substrate 10 based on the light intensity distribution measured by the measurement unit 110, and controls the positioning of the substrate 10 based on the detection result. Specifically, the control unit 130 controls the measurement unit 110 to measure the light intensity distribution under multiple types of measurement conditions. Then, from each of the light intensity distributions obtained under the multiple types of measurement conditions, it identifies candidates for the position of the periphery 12 of the substrate 10 in the radial direction k. Then, based on the identified candidates, the control unit 130 selects one measurement condition from the multiple types of measurement conditions to determine the position of the substrate 10, and uses that one measurement condition to determine the position (orientation and center of gravity) of the substrate 10. As a result, the control unit 130 can accurately position the substrate 10 based on the determined position of the substrate 10. Note that the positioning of the substrate 10 may be understood as driving the substrate 10 so that it is positioned in a predetermined location, that is, so that the misalignment of the substrate 10 is reduced.

[0024] The memory unit 133 stores information necessary for executing the pre-alignment process. For example, the memory unit 133 stores a program for executing the pre-alignment process and multiple types of measurement conditions used in the pre-alignment process (for example, parameters for setting the measurement conditions). The memory unit 133 also stores position information of the periphery 12 of the substrate 10 determined by the processor 131, and algorithms to be applied to the light intensity distribution measured by the measurement unit 110. In the following, the position of the periphery 12 of the substrate 10 in the radial direction may be referred to as the "periphery position".

[0025] [Detection of peripheral position] An example of detecting the peripheral position of the substrate 10 will be explained with reference to Figures 2 to 6. Figures 2 to 6 show examples of detecting the peripheral position of the substrate 10 for each of several types of substrates 10 that differ in material and structure from one another. Each of Figures 2 to 6 shows the structure of the peripheral portion 13 of the substrate 10 and the corresponding light intensity distribution obtained by the light receiving unit 112 of the measurement unit 110. The light intensity distribution is represented with the radial position of the substrate 10 on the horizontal axis and the light intensity received by the light receiving unit 112 (light intensity) on the vertical axis.

[0026] Figure 2 shows an example where the substrate 10 is an opaque substrate (e.g., a silicon substrate) and the peripheral edge 13 of the substrate 10 is chamfered. In this example, a portion of the light from the light source 111 is blocked by the substrate 10, so only the light that has passed through the space outside the peripheral edge 12 of the substrate 10 enters the light receiving unit 112 of the measurement unit 110. Therefore, the light intensity distribution 140 obtained by the light receiving unit 112 has a shape in which the light intensity changes significantly with respect to the peripheral edge 12 of the substrate 10, as shown in Figure 2.

[0027] In an algorithm for detecting the peripheral position of a non-transparent substrate 10, where the peripheral edge portion 13 of the substrate 10 is chamfered, a determination threshold 141 is used, which is set between the light intensity obtained outside the peripheral edge 12 of the substrate 10 and the light intensity obtained inside the substrate 10. In this algorithm, the location 142 in the light intensity distribution 140 measured by the measurement unit 110 where the light intensity falls below the determination threshold 141 is identified as the peripheral position of the substrate 10. In other words, in this algorithm, the location 142 in the light intensity distribution 140 measured by the measurement unit 110 where the light intensity first falls below the determination threshold 141 moving from the peripheral edge of the substrate 10 towards the center (center of gravity) is identified as the peripheral position of the substrate 10. Thus, in the example in Figure 2, the control unit 130 can detect (identify) the peripheral position of the substrate 10 by applying an algorithm using the determination threshold 141 to the light intensity distribution. Note that if the substrate is non-transparent, the peripheral edge 12 of the substrate 10 can be detected regardless of the light intensity of the light source unit 111.

[0028] Figure 3 shows an example where the substrate 10 is a transparent substrate (e.g., a glass substrate) and the peripheral edge 13 of the substrate 10 is not chamfered. In this example, the light source 111 emits light of normal intensity. In this example, some of the light from the light source 111 passes through the substrate 10, and at that time, the light intensity of some of the light decreases (i.e., is attenuated). Therefore, the light intensity distribution 146 obtained by the light receiving unit 112 of the measurement unit 110 has a shape in which the light intensity changes with respect to the peripheral edge 12 of the substrate 10, as shown in Figure 3. However, in this example, because the substrate 10 allows light to pass through, the amount of change in light intensity in the light intensity distribution 146 is smaller than the amount of change in light intensity in the light intensity distribution 140 shown in Figure 2.

[0029] In an algorithm for detecting the peripheral position of a substrate 10 that is a transparent substrate and whose peripheral edge portion 13 is not chamfered, a determination threshold 147 is used, which is set between the light intensity obtained outside the peripheral edge 12 of the substrate 10 and the light intensity obtained inside the peripheral edge 12 of the substrate 10. In this algorithm, the location 148 where the light intensity of the light intensity distribution 146 measured by the measurement unit 110 meets the determination threshold 147 is identified as the peripheral position of the substrate 10. In other words, in this algorithm, the location 148 where the light intensity first falls below the determination threshold 147 in the light intensity distribution 146 measured by the measurement unit 110, moving from the peripheral edge towards the center of the substrate 10, is identified as the peripheral position of the substrate 10. Thus, in the example in Figure 3, the control unit 130 can detect (identify) the peripheral position of the substrate 10 by applying an algorithm using the determination threshold 147 to the light intensity distribution.

[0030] Figure 4 shows an example where the substrate 10 is a transparent substrate (e.g., a glass substrate) and the peripheral edge 13 of the substrate 10 is not chamfered. In this example, unlike the example in Figure 3, the light source 111 emits light with an intensity significantly higher than normal. Here, as an example, light with an intensity nine times that of normal is emitted. Normally, some of the light from the light source 111 passes through the substrate 10, and at that time, the intensity of some of that light decreases (i.e., is attenuated). However, here, because the light intensity of the light from the light source 111 is high, the light intensity distribution 149 obtained by the light receiving unit 112 of the measurement unit 110 maintains a constant shape with no change in light intensity at the peripheral edge 12 of the substrate 10, as shown in Figure 4. This is because the light intensity of the light from the light source 111 is high, and even after attenuation by the substrate 10, the intensity remains higher than the light intensity threshold that can be measured by the light receiving unit 112. When the light receiving unit 112 receives light with an intensity exceeding the measurable light intensity threshold, it enters a saturated state, and the acquired waveform does not rise any further. In the example in Figure 4, if the same algorithm (decision threshold 147) as in the example in Figure 3 is used, the peripheral position of the substrate 10 cannot be detected (identified).

[0031] Figure 5 shows an example where the substrate 10 consists of an opaque substrate 26 (e.g., a silicon substrate) and a transparent film 22 attached thereon. The outer shape of the transparent film 22 is larger than that of the opaque substrate 26. The edges of the opaque substrate 26 are also chamfered. In this example, a portion of the light from the light source 111 is blocked by the opaque substrate 26. In addition, a portion of the light that passes outside the periphery 27 of the opaque substrate 26 passes through the transparent film 22, and in doing so, the light intensity of a portion of that light decreases (i.e., is attenuated). Therefore, the light intensity distribution 154 obtained by the light receiving unit 112 of the measurement unit 110 has the shape shown in Figure 5.

[0032] In the example shown in Figure 5, a determination threshold 156 is used in the algorithm for detecting the peripheral position of the opaque substrate 26. The determination threshold 156 is set between the light intensity obtained outside the peripheral edge 23 of the transparent film 22 and the light intensity obtained inside the opaque substrate 26. In this algorithm, the location 155 where the light intensity of the light intensity distribution 154 measured by the measurement unit 110 becomes the determination threshold 156 may be incorrectly identified as the peripheral position of the opaque substrate 26.

[0033] Figure 6 shows an example where the substrate consists of a non-transparent substrate 26 (e.g., a silicon substrate) and a transparent film 22 attached thereon. In this example, the light source 111 emits light of a higher intensity than normal. Here, as an example, light nine times the normal intensity is emitted. Normally, some of the light from the light source 111 passes through the transparent film 22, and at that time, the intensity of some of that light decreases (i.e., is attenuated). However, in this example, because the light from the light source 111 is high, the light intensity distribution 164 obtained by the light receiving unit 112 of the measurement unit 110 does not change with respect to the periphery 23 of the transparent film 22, as shown in Figure 6. This is because the light intensity of the light from the light source 111 is high, and even after being attenuated by the transparent film 22, it remains above the threshold of light intensity that can be measured by the light receiving unit 112. Furthermore, since a portion of the light from the light source 111 is further blocked by the opaque substrate 26, the light receiving unit 112 of the measurement unit 110 receives both light that has passed through the space outside the peripheral edge 23 of the transparent film 22 and light that has passed through the transparent film 22. Therefore, the light intensity distribution 164 obtained by the light receiving unit 112 has a shape in which the light intensity changes significantly with the peripheral edge 27 of the opaque substrate 26 as the boundary, as shown in Figure 6.

[0034] In this algorithm, the location 157 where the light intensity of the light intensity distribution 164 measured by the measurement unit 110 meets the judgment threshold 156 is identified as the peripheral position of the opaque substrate 26. In other words, in this algorithm, the location 157 where the light intensity first falls below the judgment threshold 156 in the light intensity distribution 164 measured by the measurement unit 110, moving from the periphery of the opaque substrate 26 towards the center, is identified as the peripheral position of the opaque substrate 26.

[0035] As described above, the light intensity distribution measured by the measurement unit 110 (light receiving unit 112) changes depending on the material of the substrate 10, its transparency (transparent / opaque), whether or not the peripheral edge portion 13 is chamfered, and whether or not it is bonded. In other words, if the type of substrate 10 changes, the trend of the light intensity distribution measured by the measurement unit 110 may change. Therefore, in order to accurately detect the peripheral position of the substrate 10 even if the type of substrate 10 changes, it is necessary to appropriately select the measurement conditions when acquiring the light intensity distribution according to the type of substrate. However, performing the process of measuring the light intensity distribution by the measurement unit 110 while rotating the substrate 10 multiple times with different measurement conditions can be disadvantageous in terms of throughput. In other words, in the pre-alignment process, it is desirable to achieve both throughput and detection accuracy when detecting the position of the substrate 10. Therefore, in this embodiment, multiple types of light intensity distributions (measurement results) are acquired by applying multiple types of measurement conditions in a single measurement by the measurement unit 110, and a candidate for the peripheral position of the substrate 10 is identified from each of the multiple light intensity distributions. Then, based on the identified candidates, one measurement condition is selected from among several types of measurement conditions to determine the position of the substrate 10. In the following, candidates for the peripheral position of the substrate 10 may be referred to as "peripheral position candidates."

[0036] Here, the multiple types of measurement conditions may include at least two types of measurement conditions in which at least one of the following is different from each other: the light intensity, wavelength, irradiation direction of the light emitted from the light source unit 111, and the light intensity threshold that can be measured by the light receiving unit 112. For example, in the examples of Figures 3 and 4 described above, the light intensity of the light emitted from the light source unit 111 may be different from each other.

[0037] [Selection of measurement conditions] The selection of measurement conditions can be performed, for example, by determining an evaluation value for each of several candidate peripheral positions. The evaluation value for each of the several candidate peripheral positions can be determined based on at least one of the following: the similarity between the outer shape of the substrate 10 obtained from the peripheral position and the first reference shape, and the roundness of the outer shape of the substrate 10 obtained from the peripheral position. The evaluation value may also be determined additionally or alternatively based on the similarity between the shape of the notch of the substrate 10 obtained from the peripheral position and the second reference shape.

[0038] The control unit 130 rotates the substrate 10 using the substrate holding unit 120 and sequentially measures the radial light intensity distribution using the measurement unit 110, thereby obtaining a position waveform 50 that shows the relationship between the position in the θZ direction (circumferential direction) and the peripheral position, as shown in Figure 7(A). In Figure 7(A), the horizontal axis shows the position in the θZ direction of the peripheral portion 13 where the light intensity distribution was measured by the measurement unit 110 (i.e., the rotation angle θ of the substrate 10), and the vertical axis shows the radial peripheral position identified from the light intensity distribution measured by the measurement unit 110. The position waveform 50 may be understood as representing the outer shape of the substrate 10 obtained from the detection result of the peripheral position. The position waveform 50 also includes a partial waveform 51 corresponding to the notch of the substrate 10. The example in Figure 7(A) shows the case where the notch of the substrate 10 is a notch.

[0039] For example, the control unit 130 can determine an evaluation value based on at least one of the following: the similarity between the position waveform 50 representing the outer shape of the substrate 10 and the ideal position waveform 52 representing the ideal outer shape of the substrate 10, and the roundness of the outer shape of the substrate 10 obtained from the position waveform 50. The similarity between the position waveform 50 and the ideal position waveform 52 can be calculated based on the error 54 between the position waveform 50 and the ideal position waveform 52 shown in Figure 7(B). The ideal position waveform 52 is a waveform that represents the ideal outer shape of the substrate 10 and may be understood as representing a reference shape (first reference shape) related to the outer shape of the substrate 10. Based on the position waveform 50, the control unit 130 can obtain the ideal position waveform 52 using the following equation (1) by determining the eccentricity (X,Y) of the substrate 10 with respect to the rotation center 125 of the substrate 10 by the substrate holding part 120 and the rotation angle θ.

number

[0040] Here, equation (1) will be explained using Figure 8. In Figure 8, the θZ direction indicates the circumferential direction of the substrate 10, and the R direction indicates the radial direction of the substrate 10. As shown in Figure 8, if the center of gravity 24 (center) of the substrate 10 is eccentric with respect to the rotation center 125 of the substrate 10 by the substrate holding part 120, then "r" represents the magnitude of the eccentricity vector 25 (the distance between the rotation center 125 and the center of gravity 24 of the substrate 10). "θ" is the rotation angle of the substrate 10 by the substrate holding part 120. The rotation angle θ may be understood as representing the position in the θZ direction of the peripheral portion 13 where the light intensity distribution was measured by the measurement unit 110. "α" represents the angle between the eccentricity vector 25 and the straight line connecting the rotation center 125 and the light receiving unit 112 (light receiving element 112a). "L" is the radius 28 of the substrate 10.

[0041] Furthermore, the control unit 130 may determine an evaluation value based on the similarity between a partial waveform 51 representing the shape of the notch in the substrate 10 and an ideal partial waveform 53 representing the ideal outer shape of the notch, as shown in Figure 7(A). The similarity between the partial waveform 51 and the ideal partial waveform 53 can be calculated based on the error 55 between the partial waveform 51 and the ideal partial waveform 53 shown in Figure 7(B). The ideal partial waveform 53 is understood to represent a reference shape (second reference shape) related to the outer shape of the notch in the substrate 10. This may be done, and can be obtained from the design information (design data, specification information) of the notch of the substrate 10.

[0042] [Pre-alignment process operation flow] Next, the operation flow of the pre-alignment process in this embodiment will be described. Figure 9 is a flowchart showing the operation flow of the pre-alignment process in this embodiment. The flowchart in Figure 9 can be executed by the control unit 130.

[0043] In step S301, the control unit 130 adjusts the brightness of the light source unit 111 in the measurement unit 110 before loading the substrate 10 onto the substrate holding unit 120 of the substrate processing apparatus 100. It is preferable that the light source unit 111 is adjusted when the substrate 10, which acts as a light shield, is not in the optical path. If the light source unit 111 is adjusted after loading the substrate 10 onto the substrate holding unit 120, the amount of light cannot be checked in the area shielded by the substrate 10. As a result, the signal strength may exceed an acceptable value during the rotation of the substrate 10.

[0044] In step S302, the control unit 130 loads the substrate 10 onto the substrate holding section 120 of the substrate processing apparatus 100 using a substrate transport mechanism (substrate transport robot) not shown. The substrate 10 loaded onto the substrate holding section 120 is held by a substrate chuck 123. At the stage when the substrate 10 is loaded onto the substrate holding section 120, the substrate 10 has not been positioned, and the substrate 10 is shifted in the translational and rotational directions relative to the desired position on the substrate holding section 120.

[0045] Steps S303 to S305 are the steps (first measurement steps) in which the measurement unit 110 measures the light intensity distribution. In step S303, the control unit 130 starts rotating the substrate 10 in the θZ direction using the substrate holding unit 120 (rotation drive unit 121), and starts measuring the light intensity distribution of the peripheral portion 13 of the substrate 10 using the measurement unit 110. In step S304, the control unit 130 controls the light source unit 111, for example, to measure the light intensity distribution while periodically and alternately switching between two or more measurement conditions. The control unit 130 sequentially acquires the information (data) of the light intensity distribution measured by the measurement unit 110 from the measurement unit 110 and stores it in the storage unit 133. Next, in step S305, the control unit 130 rotates the substrate 10 by the amount of rotation necessary to determine the position of the substrate 10 (for example, 360 degrees), and then terminates the rotational drive of the substrate 10 by the substrate holding unit 120 and the measurement of the light intensity distribution by the measurement unit 110. The measurement of the light intensity distribution is performed while the substrate 10 is being rotated in the θZ direction by the substrate holding unit 120 (rotational drive unit 121). In other words, the measurement unit 110 sequentially (continuously) measures the radial light intensity distribution for a part of the peripheral portion 13 of the substrate 10 while the substrate holding unit 120 is rotating the substrate 10. As a result, the control unit 130 can obtain the radial light intensity distribution for the entire peripheral portion 13 of the substrate 10. Since one light intensity distribution is obtained for each measurement condition, a number of light intensity distributions corresponding to the types of measurement conditions can be obtained here.

[0046] In step S306, the control unit 130 identifies candidate peripheral positions from each of the multiple types of light intensity distributions obtained through steps S303 to S305 (identification step). Specifically, the control unit 130 classifies the light intensity distributions obtained under multiple measurement conditions according to the measurement conditions, and calculates the position waveform 50 shown in Figure 7(A) for each of the classified light intensity distributions. As mentioned above, the position waveform 50 is a waveform that shows the relationship between the position of the substrate 10 in the θZ direction and the peripheral position, and may be understood as representing the outline of the substrate 10. The position waveform 50 may include a partial waveform 51 corresponding to a notch in the substrate 10. For example, the control unit 130 plots the candidate peripheral positions of the substrate 10 identified for each measurement condition in correspondence with the position of the substrate 10 in the θZ direction. This allows the control unit 130 to calculate the position waveform 50 for each measurement condition.

[0047] In step S307, the control unit 130 calculates the ideal position waveform 52 for each measurement condition. Specifically, as described above, the control unit 130 calculates the ideal position waveform 52 for each measurement condition by determining the eccentricity (X,Y) of the substrate 10 with respect to the rotation center 125 of the substrate 10 by the substrate holding unit 120 and the rotation angle θ based on the position waveform 50 for each measurement condition.

[0048] In step S308, the control unit 130 obtains an evaluation value for each of the multiple peripheral position candidates (evaluation step). Step S308 may be understood as a step of obtaining an evaluation value for each of the multiple types of measurement conditions. In this embodiment, the control unit 130 can obtain an evaluation value based on at least one of the following: the similarity between the position waveform 50 and the ideal position waveform 52, the roundness of the outer shape of the substrate 10 obtained from the position waveform 50, and the similarity between the partial waveform 51 and the ideal partial waveform 53. For example, the control unit 130 can obtain an evaluation value by calculating the similarity between the position waveform 50 and the ideal position waveform 52 from the sum or variance of the errors 54 between the position waveform 50 and the ideal position waveform 52 shown in Figure 7(B). Alternatively, the control unit 130 can obtain an evaluation value by calculating the roundness from the error between the outer shape of the substrate 10 obtained from the position waveform 50 and a perfect circle. The control unit 130 may obtain an evaluation value by calculating the similarity between the partial waveform 51 and the ideal partial waveform 53 from the sum or variance of the errors 55 between the partial waveform 51 and the ideal partial waveform 53 shown in Figure 7(B).

[0049] Here, the control unit 130 may determine an evaluation value based on a plurality of evaluation indices obtained from the peripheral position candidates. The plurality of evaluation indices may include at least two of the following: the similarity between the position waveform 50 and the ideal position waveform 52, the roundness of the outer shape of the substrate 10 obtained from the position waveform 50, and the similarity between the partial waveform 51 and the ideal partial waveform 53. In this case, the control unit 130 may weight each of the plurality of evaluation indices and determine an evaluation value based on the results. For example, the control unit 130 can determine the evaluation value as the sum of the plurality of weighted evaluation indices.

[0050] In step S309, the control unit 130 selects one measurement condition from among several types of measurement conditions as the optimal measurement condition for determining the position of the substrate 10, based on the evaluation value obtained for each peripheral position candidate in step S308 (selection step). For example, the control unit 130 can select the peripheral position candidate with the best evaluation value from among multiple peripheral position candidates, and then select the measurement condition used to identify the selected peripheral position candidate as the optimal measurement condition. As a specific example, if the control unit 130 obtains the sum of the errors 54 between the position waveform 50 and the ideal position waveform 52 as the evaluation value, it can select the measurement condition of the light intensity distribution used to identify the peripheral position candidate with the smallest evaluation value among multiple peripheral position candidates as the optimal measurement condition. On the other hand, if the control unit 130 obtains the reciprocal of the sum of the errors 54 between the position waveform 50 and the ideal position waveform 52 as the evaluation value, it can select the measurement condition used to identify the peripheral position candidate with the largest evaluation value among multiple peripheral position candidates as the optimal measurement condition.

[0051] Steps S310 to S313 are steps to control the positioning of the substrate 10 using the measurement conditions selected in step S309. In this embodiment, the positioning of the substrate 10 may include positioning the substrate 10 while it is being held by the substrate holding unit 120, and positioning the substrate 10 when it is being transported from the substrate holding unit 120 to the target transport destination. The target transport destination may be, for example, the substrate stage of a lithography apparatus.

[0052] In step S310, the control unit 130 detects the position of the peripheral portion 13 (e.g., the notch) of the substrate 10 being held by the substrate holding unit 120, based on the peripheral position candidates identified by the optimal measurement conditions.

[0053] Next, in step S311, the control unit 130 performs a precision measurement (second measurement step) in which the measurement unit 110 remeasures the light intensity distribution of the peripheral portion 13 of the substrate 10 under optimal measurement conditions. In the precision measurement, first, the control unit 130 positions the substrate 10 so that the peripheral portion 13 (notch) of the substrate 10 is positioned in the optical path of the measurement unit 110, based on the position of the peripheral portion 13 (notch) of the substrate 10 detected in step S310. The positioning of the substrate 10 may be performed by driving the substrate 10 in translation and rotation using the substrate holding unit 120, or by repositioning the substrate 10 on the substrate holding unit 120 using a substrate transport mechanism (substrate transport robot) not shown. Next, while the substrate 10 is rotated by the substrate holding unit 120, the control unit 130 sequentially measures the light intensity distribution of the peripheral portion 13 of the substrate 10 under optimal measurement conditions using the measurement unit 110. In this embodiment, the control unit 130 can precisely measure the light intensity distribution of the notched portion of the peripheral edge 13 of the substrate 10. By performing such precise measurements, it is possible to reduce the decrease in processing accuracy caused by misalignment of the substrate 10 during subsequent substrate transport and processing operations.

[0054] In step S312, the control unit 130 determines the position of the substrate 10 (determination step). Specifically, the control unit 130 identifies the peripheral position of the substrate 10 by applying a predetermined algorithm to the light intensity distribution acquired in step S111. Then, the control unit 130 calculates a position waveform 50 from the identified peripheral position of the substrate 10 and determines the position of the substrate 10 based on the position waveform 50. The position of the substrate 10 determined in step S112 may include at least one of the following: the outline of a local area including the notch in the peripheral portion 13 of the substrate 10, the peripheral position of the substrate 10, and the centroid position of the substrate 10.

[0055] In step S313, the control unit 130 transports the substrate 10 from the substrate holding unit 120 to the target transport destination using a substrate transport mechanism (substrate transport robot) not shown. At this time, the control unit 130 can control the positioning of the substrate 10 when transporting it from the substrate holding unit 120 to the target transport destination, based on the position of the substrate 10 determined in step S112. For example, the control unit 130 can calculate the eccentricity of the position X, Y, and θZ of the substrate 10 relative to the substrate holding unit 120 based on the position of the substrate 10 determined in step S112, and control the positioning of the substrate 10 based on that eccentricity. The positioning of the substrate 10 can be controlled so that the substrate 10 is in a predetermined position and orientation.

[0056] In a preferred embodiment, the two or more measurement conditions may differ in the light intensity of the light emitted from the light source 111, or in the wavelength of the light. The light intensity of the measurement conditions may be set according to the transmittance of the substrate. Furthermore, if there are two or more light source units 111, the two or more measurement conditions may differ in the irradiation angles of the light from the light source units 111. Here, different irradiation angles mean, for example, that the first light source irradiates the substrate 10 from below, and the second light source irradiates the substrate 10 from the side or oblique direction. Here, for example, if a transparent film 22 is attached to the upper surface of the non-transparent substrate 26 as shown in Figure 5, the light from below the substrate 10 passes through the transparent film 22, causing a decrease in the light intensity of a portion of the light (i.e., attenuation). However, since the light receiving unit 112 receives light scattered by the periphery 27 of the non-transparent substrate 26 and the periphery 23 of the transparent film 22 when light is coming from the side or oblique direction, the periphery 12 of the substrate 10 can be detected without attenuation. Furthermore, two or more measurement conditions may have different light intensity thresholds that can be measured by the light receiving unit 112. Here, the light intensity threshold that can be measured by the light receiving unit 112 can also be said to be the range of light intensity that can be measured by the light receiving unit 112. For example, in the example of Figure 4, the light source unit 111 emits light of an intensity higher than normal light intensity and higher than a predetermined intensity. When a portion of the light from the light source unit 111 passes through the transparent substrate, the light intensity of a portion of that light decreases (i.e., it is attenuated). However, the light emitted here has a light intensity higher than the light intensity threshold that can be measured by the light receiving unit 112, and even after being attenuated by the transparent substrate, it still exceeds that threshold. In such cases, by setting a high threshold for the light intensity measurable by the light receiving unit 112, it becomes possible to obtain a light intensity distribution with a shape in which the light intensity changes significantly with respect to the peripheral edge 12 of the transparent substrate. Note that multiple types of measurement conditions are acceptable as long as one of the following differs from the other measurement conditions: the light intensity, wavelength, irradiation direction of the light source unit 111, and the light intensity threshold measurable by the light receiving unit 112.

[0057] Here, steps S306 to S309 described above will be explained in more detail with reference to Figures 10 to 12. In step S304, while measuring the light intensity distribution, the control unit 130 controls, for example, the light source unit 111 to periodically and alternately switch between two or more types, i.e., multiple types of measurement conditions. The control unit 130 acquires the measurement results of the measured light intensity distribution while periodically and alternately switching between the multiple types of measurement conditions. Here, for example, the multiple types of measurement conditions are measurement condition A and measurement condition B. Here, as an example, measurement condition A and measurement condition B differ in the intensity of the light emitted from the light source unit 111. In measurement condition A, the light intensity of the light emitted from the light source unit 111 is the normal light intensity, and in measurement condition B, the light intensity of the light emitted from the light source unit 111 is higher than a predetermined light intensity.

[0058] In step S306, as shown in Figure 10(A), the position waveform 60 and partial waveform 61 measured under measurement condition A and the position waveform 62 and partial waveform 63 measured under measurement condition B are acquired periodically and alternately. Furthermore, in step S306, the control unit 130 classifies the measurement results shown in Figure 10(A) into the position waveform 60 and partial waveform 61 measured under measurement condition A shown in Figure 10(B) and the position waveform 62 and partial waveform 63 measured under measurement condition B shown in Figure 10(C). In this way, the position waveform 60 and partial waveform 61 of measurement condition A and the position waveform 62 and partial waveform 63 of measurement condition B can be obtained.

[0059] In step S307, the control unit 130 calculates the ideal position waveform 64 shown in Figure 10(B) from the position waveform 60 corresponding to measurement condition A, and the ideal position waveform 65 shown in Figure 10(C) from the position waveform 62 corresponding to measurement condition B.

[0060] In step S308, as shown in Figure 10(D), the control unit 130 evaluates the error 68 between the position waveform 60 and the ideal position waveform 64, and the error 69 between the partial waveform 61 and the ideal partial waveform 66 under measurement condition A, and obtains evaluation values. Furthermore, as shown in Figure 10(E), the control unit 130 evaluates the error 70 between the position waveform 62 and the ideal position waveform 65, and the error 71 between the partial waveform 63 and the ideal partial waveform 67 under measurement condition B, and obtains evaluation values. In other words, the control unit 130 obtains evaluation values ​​for each of the multiple types of measurement conditions.

[0061] In step S308, when evaluating measurement condition A, the control unit 130 calculates the outer shape of the substrate 10 from the position waveform 60 as the outer perimeter shape of the substrate, as shown in Figure 11(A), and calculates an ideal circle (first reference shape) from the ideal position waveform 64. Based on this, the control unit 130 can determine an evaluation value based on the similarity between the position waveform 60 and the ideal position waveform 64, obtained from the error between the outer perimeter shape of the substrate and the ideal circle, and / or the roundness of the outer perimeter shape of the substrate. Furthermore, when evaluating measurement condition A, the control unit 130 calculates the outer shape of the notch of the substrate 10 (hereinafter sometimes referred to as the notch shape) from the partial waveform 61, as shown in Figure 11(B), and calculates the ideal notch shape (second reference shape) of the substrate 10 from the ideal partial waveform 66. Based on this, the control unit 130 can determine an evaluation value based on the similarity between the partial waveform 61 and the ideal partial waveform 64, obtained from the error between the notch shape and the ideal notch shape. Such evaluation values ​​are obtained for each measurement condition. Figure 12 schematically shows the evaluation values ​​obtained for each of the multiple measurement conditions A to B.

[0062] In step S309, the control unit 130 can select the one measurement condition (measurement condition B in Figure 12) with the best evaluation value from among multiple types of measurement conditions A to B, based on the evaluation values ​​obtained for each measurement condition A to B, as the optimal measurement condition.

[0063] Specifically, for example, suppose that the substrate 10 is a substrate consisting of a non-transparent substrate (e.g., a silicon substrate) and a transparent film attached thereon, with the transparent film extending beyond the outer edge of the silicon substrate. Measurement condition A is imaging with normal light intensity, and the measurement result under measurement condition A is as shown in Figure 5. On the other hand, measurement condition B is imaging with a higher-than-normal light intensity, and the measurement result under measurement condition B is as shown in Figure 6. In such a case, the evaluation value is better under measurement condition B than under measurement condition A, so the control unit 130 sets measurement condition B as the optimal measurement condition. As a result, in steps S310 to S313, the control unit 130 emits light with the light intensity of measurement condition B from the light source unit 111.

[0064] As described above, the substrate processing apparatus 100 of this embodiment obtains multiple types of light intensity distributions in a single measurement by periodically and alternately switching between multiple types of measurement conditions during a single light intensity distribution measurement. Then, peripheral position candidates are identified from each of the obtained light intensity distributions, and based on the multiple peripheral position candidates, one measurement condition is selected as the optimal measurement condition from among the multiple types of measurement conditions to determine the position of the substrate 10. According to this embodiment, the process of measuring the light intensity distribution by the measurement unit 110 while rotating the substrate 10 is not performed multiple times with different types of measurement conditions, and the optimal measurement condition can be appropriately selected using the light intensity distribution obtained in a single measurement. In other words, both throughput and detection accuracy can be achieved when detecting the position of the substrate 10.

[0065] In the above-described embodiment, the light intensity distributions for multiple measurement conditions were obtained in a single measurement by periodically and alternately switching between multiple types of measurement conditions. However, for example, the substrate processing apparatus 100 may be configured with multiple measurement units 110, i.e., multiple light source units 111 and multiple light receiving units 112, and the light intensity distributions may be measured in each of the multiple measurement units 110 under different measurement conditions in a single measurement. In other words, multiple measurement units 110 can be used to obtain multiple types of measurement results in parallel. Even with such a configuration, the light intensity distributions for multiple measurement conditions can be obtained in a single measurement.

[0066] Furthermore, in the above-described embodiment, the measurement of the light intensity distribution is performed while the substrate 10 is rotated in the θZ direction by the substrate holding unit 120 (rotation drive unit 121). However, for example, when detecting local overhang of the transparent film 22, the measurement of the light intensity distribution may be performed with the substrate 10 stopped. Also, when detecting local peripheral positions of the substrate, such as when detecting local overhang of the transparent film 22, the measurement of the light intensity distribution may be performed by switching between two or more measurement conditions at least twice.

[0067] <Second Embodiment> A second embodiment of the present invention will now be described. This embodiment basically follows the first embodiment, and can be used in accordance with the first embodiment except for matters mentioned below. Similar components are denoted by the same reference numerals and their descriptions are omitted. The configuration of the substrate processing apparatus shown in Figure 1 is also similar and its description is omitted.

[0068] Figure 13 is a flowchart showing the operation flow of the pre-alignment process in the second embodiment. The flowchart in Figure 13 can be executed by the control unit 130. Steps S401 to S406 in the flowchart of Figure 13 are the same as steps S301 to S306 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0069] In step S407, the control unit 130 detects the position of the peripheral portion 13 (e.g., a notch) of the substrate 10 while it is being held by the substrate holding unit 120. The detection of the position of the peripheral portion 13 in step S407 may be based on peripheral position candidates obtained by predetermined measurement conditions, or on peripheral position candidates obtained by measurement conditions used in the previous determination step. The measurement conditions used in the previous determination step may be the measurement conditions used in the previous lot, or the measurement conditions used in the previous substrate.

[0070] In step S408, the control unit 130 positions the substrate 10 based on the position of the peripheral portion 13 (notch) of the substrate 10 detected in step S407, so that the peripheral portion 13 (notch) of the substrate 10 is positioned in the optical path of the measurement unit 110. The positioning of the substrate 10 may be performed by driving the substrate 10 in translation and rotation using the substrate holding unit 120, or by repositioning the substrate 10 on the substrate holding unit 120 using a substrate transport mechanism (substrate transport robot) not shown.

[0071] Furthermore, steps S409 to S411 are performed in parallel with step S408. In step S409, as described in the first embodiment, the control unit 130 determines the eccentricity (X,Y) of the substrate 10 with respect to the rotation center 125 of the substrate 10 by the substrate holding unit 120 and the rotation angle θ based on the position waveform 50 for each measurement condition. This allows for the calculation of the ideal position waveform 52 for each measurement condition.

[0072] In step S410, the control unit 130 obtains an evaluation value for each of the multiple peripheral position candidates. Then, in step S411, based on the evaluation values ​​obtained for each peripheral position candidate in step S410, the control unit 130 selects one measurement condition from among multiple types of measurement conditions as the optimal measurement condition to be used to determine the position of the substrate 10. Steps S409 to S411 are the same as steps S307 to S309 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0073] In step S412, the control unit 130 performs a precision measurement by re-measuring the light intensity distribution of the peripheral portion 13 of the substrate 10 under optimal measurement conditions using the measurement unit 110. In the precision measurement of this embodiment, since the positioning of the substrate 10 has already been performed in step S408, only the process of sequentially measuring the light intensity distribution of the peripheral portion 13 of the substrate 10 by the measurement unit 110 while rotating the substrate 10 with the substrate holding unit 120 can be performed. Note that step S412 is the same process as step S311 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0074] In step S413, the control unit 130 determines the position of the substrate 10. Specifically, in step S412, the control unit 130 identifies the peripheral position of the substrate 10 from the light intensity distribution acquired under optimal measurement conditions. Next, in step S414, the control unit 130 transports the substrate 10 from the substrate holding unit 120 to the target transport destination using a substrate transport mechanism (substrate transport robot) not shown. Note that steps S413 to S414 are the same as steps 3S312 to S313 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0075] As described above, in this embodiment, the calculation of evaluation values ​​is performed in parallel with the control of the positioning of the substrate 10. This makes it possible to further improve the throughput of the substrate processing apparatus 100.

[0076] <Third Embodiment> A third embodiment of the present invention will now be described. This embodiment basically follows the first embodiment, and except for matters mentioned below, it can be carried out according to the first embodiment. Furthermore, this embodiment may also be adapted from the second embodiment. Similar components are denoted by the same reference numerals and their descriptions are omitted. Similarly, the configuration of the substrate processing apparatus shown in Figure 1 is also the same and its description is omitted.

[0077] Figure 14 is a flowchart showing the operation flow of the pre-alignment process in the third embodiment. The flowchart in Figure 14 can be executed by the control unit 130. Steps S501 to S510 in the flowchart of Figure 14 are the same as steps S301 to S310 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0078] In step S511, the control unit 130 positions the substrate 10 based on the position of the peripheral portion 13 (notch) of the substrate 10 detected in step S510, so that the peripheral portion 13 (notch) of the substrate 10 is positioned in the optical path of the measurement unit 110. The positioning of the substrate 10 may be performed by translating and rotating the substrate 10 with the substrate holding unit 120, or by repositioning the substrate 10 on the substrate holding unit 120 with a substrate transport mechanism (substrate transport robot) not shown.

[0079] In step S512, the control unit 130 starts the translational drive of the substrate 10 in the X direction by the substrate holding unit 120 (translational drive unit 122), and starts measuring the light intensity distribution by the measurement unit 110. For example, while the substrate 10 is being translated in the X direction by the substrate holding unit 120, the light receiving unit 112 (light receiving element 112a) of the measurement unit 110 receives light from the light source unit 111 and continuously acquires the light intensity distribution of the peripheral portion 13 of the substrate 10, including the notch, in the X direction. Here, the light source unit 111 periodically switches between two or more measurement conditions, and the light receiving unit 112 continuously acquires the light intensity distribution of the peripheral portion 13 in the X direction under multiple measurement conditions. Here, the multiple measurement conditions are, for example, measurement condition A and measurement condition B, the same as in the first embodiment. In step S512, the notch of the substrate 10 is translated in the X direction relative to the optical path of the measurement unit 110, thereby measuring the light intensity distribution of the notch in the substrate 10.

[0080] In step S513, the control unit 130 sequentially acquires information (data) on the light intensity distribution measured by the measurement unit 110 from the measurement unit 110 and stores it in the storage unit 133. Next, in step S514, the control unit 130 translates the substrate 10 by the amount necessary to determine the position of the substrate 10, and then terminates the translational drive of the substrate 10 and the measurement of the light intensity distribution by the measurement unit 110.

[0081] In step 515, the control unit 130 identifies candidate notches for the notch position of the substrate 10 from the light intensity distributions of multiple measurement conditions acquired sequentially through steps S512 to S514. As a result, the control unit 130 can obtain notch waveforms for each measurement condition, as shown in Figure 15(A). The notch waveform is the waveform corresponding to the notch of the substrate 10. In Figure 15(A), the horizontal axis shows the position in the θZ direction of the peripheral portion 13 where the light intensity distribution was measured by the measurement unit 110 (i.e., the rotation angle θ of the substrate 10), and the vertical axis shows the radial peripheral position identified from the light intensity distribution measured by the measurement unit 110. Here, the notch waveform is acquired periodically and alternately from the notch waveform 80 captured under measurement condition A and the notch waveform 81 captured under measurement condition B. The control unit 130 classifies the notch waveform shown in Figure 15(A) into notch waveform 80 measured under measurement condition A shown in Figure 15(B) and notch waveform 81 measured under measurement condition B shown in Figure 15(C), and acquires the notch waveform for each measurement condition.

[0082] In step S516, the control unit 130 obtains an ideal notch waveform 82 for measurement condition A and an ideal notch waveform 83 for measurement condition B by performing curve approximation using the least squares method on each notch waveform (here, notch waveform 80 and notch waveform 81). The ideal notch waveforms 82 and 83 may be understood as representing the ideal outer shape of the notch of the substrate 10. In this embodiment, the notch of the substrate 10 is represented as a notch, but the notch of the substrate 10 may be an orientation flat. If the notch of the substrate 10 is orientation flat, the control unit 130 calculates the ideal notch waveform by performing linear approximation using the least squares method on the waveform corresponding to the notch of the substrate 10.

[0083] In step S517, the control unit 130 determines an evaluation value for each of the multiple candidate notch positions. For example, as shown in Figure 15(D), the control unit 130 determines the error 84 between the notch waveform 80 and the ideal notch waveform 82 with respect to the rotation angle under measurement condition A, and determines an evaluation value based on this error 84. For example, the control unit 130 may determine an evaluation value based on the sum or variance of the errors 84. An evaluation value may be determined for each measurement condition. Figure 15(E) shows the error 85 between the notch waveform 81 and the ideal notch waveform 83 with respect to the rotation angle under measurement condition B.

[0084] In step S518, the control unit 130 compares the evaluation values ​​for each measurement condition obtained in step S517 and selects the measurement condition that yields the best evaluation value as the optimal measurement condition. The optimal measurement condition selected in step S518 may be the same as or different from the optimal measurement condition selected in step S509. Furthermore, the optimal measurement condition may be used for alignment of the second and subsequent substrates in a lot. In addition, when performing a measurement method that repeats the light intensity distribution measurement in S512 to S514, the optimal measurement condition selected in the first measurement may be applied to the second and subsequent measurements.

[0085] In step S519, the control unit 130 determines the position of the substrate 10 using the optimal measurement conditions selected in step S518. Specifically, the control unit 130 identifies the peripheral position of the substrate 10 using the light intensity distribution obtained under the optimal measurement conditions from the light intensity distribution acquired through steps S512 to S514. Then, the control unit 130 calculates a position waveform from the identified peripheral position of the substrate 10 and determines the position of the substrate 10 based on this position waveform.

[0086] In step S520, the control unit 130 transports the substrate 10 from the substrate holding unit 120 to the target transport destination using a substrate transport mechanism (substrate transport robot) not shown. At this time, the control unit 130 can control the positioning of the substrate 10 when transporting it from the substrate holding unit 120 to the target transport destination, based on the position of the substrate 10 determined in step S519. Note that step S520 is the same process as step S313 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0087] This embodiment, like the first embodiment, makes it possible to achieve both throughput and detection accuracy when detecting the position of the substrate 10.

[0088] <Fourth Embodiment> A fourth embodiment of the present invention will now be described. This embodiment basically follows the first embodiment, and except for matters mentioned below, it can be carried out according to the first embodiment. Furthermore, this embodiment may also be adapted from the second or third embodiment. Similar components are denoted by the same reference numerals and their descriptions are omitted. Similarly, the configuration of the substrate processing apparatus shown in Figure 1 is also the same and its description is omitted.

[0089] Figure 16 is a flowchart showing the operation flow of the pre-alignment process in the fourth embodiment. The flowchart in Figure 16 can be executed by the control unit 130. Steps S601 to S605 in the flowchart of Figure 16 are the same as steps S301 to S305 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0090] In step S606, the control unit 130 identifies multiple peripheral position candidates from the light intensity distribution obtained through steps S603 to S605 by applying each of the multiple types of algorithms to each of the multiple types of light intensity distributions obtained through steps S603 to S605. Here, the number of peripheral position candidates equal to the number of measurement condition types × the number of algorithm types can be identified. The multiple types of algorithms are set up to identify the peripheral position according to the type of substrate 10 and stored in the storage unit 133. The control unit 130 reads out the multiple algorithms from the storage unit 133 and applies each of the multiple types of algorithms to each of the multiple types of light intensity distributions of the multiple types of measurement conditions, thereby identifying multiple peripheral position candidates from the light intensity distribution of one type of measurement condition. This identification of multiple peripheral position candidates using multiple types of algorithms is performed for each of the light intensity distributions obtained sequentially through steps S603 to S605.

[0091] Here, each of the multiple types of algorithms may be set to detect (identify) the position of the periphery 12 of the substrate 10 from the light intensity distribution measured by the measurement unit 110, for each type of substrate 10 that may undergo pre-alignment processing in the substrate processing apparatus 100. Specifically, for example, it may be an algorithm for detecting the periphery 12 of a non-transparent substrate, or an algorithm for detecting the periphery 12 of a transparent substrate (e.g., a glass substrate) that has not been chamfered. It may also be an algorithm for detecting the periphery 12 of a bonded substrate consisting of a transparent support substrate (e.g., a glass substrate) and a non-transparent substrate (e.g., a silicon substrate) attached thereon. The multiple types of algorithms may include, for example, at least two algorithms with mutually different determination thresholds for identifying the periphery position of the substrate 10 from the light intensity distribution.

[0092] In step S607, the control unit 130 determines the eccentricity (X,Y) of the substrate 10 with respect to the rotation center 125 of the substrate 10 by the substrate holding unit 120 and the rotation angle θ, based on the measurement conditions and position waveform for each algorithm. This allows the control unit to calculate the ideal position waveform for each measurement condition and algorithm.

[0093] In step S608, the control unit 130 determines an evaluation value for each of the multiple peripheral position candidates (evaluation step). Step S608 is the same process as step S308 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0094] In step S609, the control unit 130 selects one measurement condition and one algorithm from among multiple types of measurement conditions and multiple types of algorithms as the optimal measurement condition and optimal algorithm to be used to determine the position of the substrate 10, based on the evaluation value obtained for each peripheral position candidate in step S608 (selection step). For example, the control unit 130 can select the peripheral position candidate with the best evaluation value from among multiple peripheral position candidates, and select the combination of measurement conditions and algorithm used to identify the selected peripheral position candidate as the optimal measurement condition and optimal algorithm. As a specific example, if the control unit 130 obtains the sum of the errors between the acquired position waveform and the ideal position waveform as the evaluation value, it can select the measurement condition and algorithm used to identify the peripheral position candidate with the smallest evaluation value from among multiple peripheral position candidates as the optimal measurement condition and optimal algorithm. On the other hand, if the control unit 130 obtains the reciprocal of the sum of the errors between the position waveform and the ideal position waveform as the evaluation value, it may select the measurement conditions and algorithm used to identify the peripheral position candidate with the largest evaluation value among multiple peripheral position candidates as the optimal measurement conditions and optimal algorithm.

[0095] Steps S610 to S613 are steps that control the positioning of the substrate 10 using the measurement conditions and algorithm selected in step S609. Steps S610 to S613 are the same as steps S310 to S313 in the flowchart of Figure 9, so a detailed explanation is omitted here.

[0096] As described above, in this embodiment, the light intensity distribution is measured on the transported substrate under two or more measurement conditions, and two or more algorithms are applied to the acquired light intensity distribution. This makes it possible to select and apply the optimal measurement conditions and algorithms for each type of substrate. Therefore, according to this embodiment, the detection accuracy of the substrate processing apparatus 100 can be further improved.

[0097] <Lithography apparatus embodiment> Embodiments of a lithography apparatus according to the present invention will be described. A lithography apparatus is used in the lithography process, which is a manufacturing process for semiconductor devices and liquid crystal display devices, to form patterns on a substrate. Examples of lithography apparatuses include exposure apparatuses that transfer the pattern of a master plate onto a substrate by exposing the substrate through a master plate. In the following, an exposure apparatus will be used as an example to describe a lithography apparatus.

[0098] Figure 17 is a schematic diagram showing an example configuration of an exposure apparatus 200. The exposure apparatus 200 transfers the pattern of the master plate R onto the substrate S by, for example, a step-and-repeat method or a step-and-scan method. As shown in Figure 17, the exposure apparatus 200 may include an illumination optical system 201, a master plate stage 202, a projection optical system 203, a substrate stage 204, a transport device 205, and a control unit 206. In the exposure apparatus 200, the illumination optical system 201, the master plate stage 202, the projection optical system 203, and the substrate stage 204 function as forming units that form a pattern on the substrate S.

[0099] Furthermore, the exposure apparatus 200 includes the substrate processing apparatus 100 described above for processing the substrate S. The substrate processing apparatus 100 performs a pre-alignment process on the substrate S. The substrate S processed by the substrate processing apparatus 100 is then transported onto the substrate stage 204 by the transport device 205. For example, the control unit 130 of the substrate processing apparatus 100 controls the positioning of the substrate S when the transport device 205 transports the substrate S onto the substrate stage 204, based on the position of the substrate S determined by the pre-alignment process. The control unit 206 of the exposure apparatus 200 and the control unit 130 of the substrate processing apparatus 100 may be configured as an integrated unit or as separate units.

[0100] <Embodiment of Article Manufacturing Method> The lithography apparatus described above can be used to implement a method for manufacturing articles for the production of various articles (semiconductor IC elements, liquid crystal display elements, MEMS, etc.). The method for manufacturing articles in the 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 method for manufacturing articles includes a processing step of processing a substrate with the above-described substrate processing method (substrate processing apparatus), a forming step of forming a pattern on the substrate after the processing step, and a manufacturing step of manufacturing an article from the substrate after the forming step. The processing step may be understood as a step of performing a pre-alignment process as a substrate processing step. Furthermore, such a method for manufacturing articles may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing articles in this embodiment is advantageous compared to conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0101] <Other Embodiments> Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist.

[0102] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by a process in which one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0103] This embodiment includes the following methods and configurations. (Method 1) A substrate processing method for processing a substrate, A first measurement step involves measuring the light intensity distribution obtained from the peripheral portion when light from a light source is irradiated onto the peripheral portion of the substrate, The process includes a selection step to identify candidates for the peripheral position of the substrate based on the measurement results obtained in the first measurement step, A substrate processing method characterized by obtaining multiple types of measurement results by performing measurements using multiple types of measurement conditions in a single first measurement step, and identifying multiple candidates based on the multiple types of measurement results in a specific step. (Method 2) The substrate processing method according to Method 1, characterized in that the measurement is performed using the multiple types of measurement conditions by switching between the multiple types of measurement conditions at least twice or periodically in the first measurement step. (Method 3) The substrate processing method according to method 1 or 2, characterized in that, in the first measurement step, the substrate is rotated while irradiating at least the peripheral portion of the substrate with light. (Method 4) A substrate processing method according to any one of methods 1 to 3, further comprising a selection step of selecting one measurement condition from among the multiple types of measurement conditions to be used to determine the position of the substrate, based on the multiple candidates identified in the specified step. (Method 5) The process further includes an evaluation step of determining an evaluation value for each of the plurality of candidates identified in the specified step, The substrate processing method according to Method 4, characterized in that, in the selection step, one measurement condition is selected from among the multiple types of measurement conditions based on the evaluation value obtained for each of the multiple candidates in the evaluation step. (Method 6) The substrate processing method according to Method 5, characterized in that, in the evaluation step, for each of the plurality of candidates, the evaluation value is determined based on the degree of similarity between the outer shape of the substrate obtained from the peripheral position and the first reference shape. (Method 7) The substrate processing method according to method 5 or 6, characterized in that, in the evaluation step, the evaluation value is determined for each of the plurality of candidates based on the roundness of the outer shape of the substrate obtained from the peripheral position. (Method 8) The substrate processing method according to any one of methods 5 to 7, characterized in that, in the evaluation step, for each of the plurality of candidates, the evaluation value is determined based on the degree of similarity between the shape of the notch of the substrate obtained from the peripheral position and the second reference shape. (Method 9) A second measurement step involves positioning the substrate so that its peripheral portion is positioned in the optical path of the light from the light source, and re-measuring the light intensity distribution obtained from the peripheral portion under the one measurement condition selected in the selection step. The process further includes a determination step of determining the position of the substrate based on the measurement results obtained in the second measurement step, The substrate processing method according to any one of methods 5 to 8, characterized in that the evaluation step is performed in parallel with the positioning of the substrate in the second measurement step. (Method 10) The substrate processing method according to method 9, characterized in that the selection step is performed in parallel with the positioning of the substrate in the second measurement step. (Method 11) The substrate processing method according to method 9 or 10, characterized in that the positioning of the substrate in the second measurement step is performed based on a candidate peripheral position identified in the specific step by a predetermined measurement condition from among the plurality of measurement conditions or the measurement condition used in the previous determination step. (Method 12) A substrate processing method according to any one of methods 1 to 11, characterized in that each of the above-mentioned multiple types of measurement conditions has a different light intensity from the light source. (Method 13) A substrate processing method according to any one of methods 1 to 12, characterized in that each of the above-mentioned multiple types of measurement conditions has a different wavelength from the light source. (Method 14) A substrate processing method according to any one of methods 1 to 13, characterized in that each of the above-mentioned multiple types of measurement conditions has a different irradiation direction of the light from the light source. (Method 15) A substrate processing method according to any one of methods 1 to 14, characterized in that each of the above-mentioned multiple types of measurement conditions has a different threshold value for light intensity that can be measured by the light receiving unit. (Method 16) The substrate processing method according to any one of methods 1 to 15, characterized in that the plurality of candidates are identified in the specified step by applying each of the plurality of algorithms to the plurality of measurement results measured in the first measurement step. (Method of manufacturing articles) A processing step of processing a substrate using the substrate processing method described in any one of Methods 1 to 16, A forming step of forming a pattern on the substrate that has undergone the processing step, A manufacturing process for producing an article from the substrate obtained through the above formation process, A method for manufacturing articles, characterized by including the following: (Composition 1) A substrate processing apparatus for processing substrates, A measuring unit that measures the light intensity distribution obtained from the peripheral portion when light is irradiated onto the peripheral portion of the substrate, A control unit for controlling the positioning of the substrate and Equipped with, The substrate processing apparatus is characterized in that the control unit causes the measurement unit to perform the measurement using multiple types of measurement conditions in a single measurement, thereby obtaining multiple types of measurement results, and identifies multiple candidates for the peripheral position of the substrate based on the multiple types of measurement results. (Configuration 2) The substrate processing apparatus according to configuration 1, characterized in that the measurement unit includes a plurality of light source units and a plurality of light receiving units. (Composition 3) A lithography apparatus for forming patterns on a substrate, A substrate processing apparatus as described in configuration 1 or 2, A forming unit for forming a pattern on the substrate processed by the substrate processing apparatus, A lithography apparatus characterized by comprising the following: [Explanation of symbols]

[0104] 10,S substrate 100 Substrate Processing Equipment 110 Measurement Unit 111 Light source section 112 Light receiving part 112a Photodetector 112b Optical system 120 Board holding part 121 Rotary drive unit 122 Translational drive unit 123 Circuit board chuck 130 Control Unit

Claims

1. A substrate processing method for processing a substrate, A first measurement step involves measuring the light intensity distribution obtained from the peripheral portion when light from a light source is irradiated onto the peripheral portion of the substrate, The process includes a selection step to identify candidates for the peripheral position of the substrate based on the measurement results obtained in the first measurement step, A substrate processing method characterized by obtaining multiple types of measurement results by performing measurements using multiple types of measurement conditions in a single first measurement step, and identifying the candidate from each of the multiple types of measurement results in the specific step.

2. The substrate processing method according to claim 1, characterized in that the measurement is performed using the multiple types of measurement conditions by switching between the multiple types of measurement conditions at least twice or periodically in the first measurement step.

3. The substrate processing method according to claim 1, characterized in that, in the first measurement step, the substrate is rotated while irradiating at least the peripheral portion of the substrate with light.

4. The substrate processing method according to claim 1, further comprising a selection step of selecting one measurement condition from among the multiple types of measurement conditions to be used to determine the position of the substrate, based on the multiple candidates identified in the specified step.

5. The process further includes an evaluation step of determining an evaluation value for each of the plurality of candidates identified in the specified step, The substrate processing method according to claim 4, characterized in that the selection step selects one measurement condition from among the multiple types of measurement conditions based on the evaluation value obtained for each of the multiple candidates in the evaluation step.

6. The substrate processing method according to claim 5, characterized in that, in the evaluation step, the evaluation value is determined for each of the plurality of candidates based on the degree of similarity between the outer shape of the substrate obtained from the peripheral position and the first reference shape.

7. The substrate processing method according to claim 5, characterized in that, in the evaluation step, the evaluation value is determined for each of the plurality of candidates based on the roundness of the outer shape of the substrate obtained from the peripheral position.

8. The substrate processing method according to claim 5, characterized in that, in the evaluation step, the evaluation value is determined for each of the plurality of candidates based on the degree of similarity between the shape of the notch of the substrate obtained from the peripheral position and the second reference shape.

9. A second measurement step involves positioning the substrate so that its peripheral portion is positioned in the optical path of the light from the light source, and re-measuring the light intensity distribution obtained from the peripheral portion under the one measurement condition selected in the selection step. The process further includes a determination step of determining the position of the substrate based on the measurement results obtained in the second measurement step, The substrate processing method according to claim 5, characterized in that the evaluation step is performed in parallel with the positioning of the substrate in the second measurement step.

10. The substrate processing method according to claim 9, characterized in that the selection step is performed in parallel with the positioning of the substrate in the second measurement step.

11. The substrate processing method according to claim 9, characterized in that the positioning of the substrate in the second measurement step is performed based on a candidate peripheral position identified in the specific step by a predetermined measurement condition from among the plurality of measurement conditions or the measurement condition used in the previous determination step.

12. The substrate processing method according to claim 1, characterized in that each of the above-mentioned multiple types of measurement conditions has a different light intensity from the light source.

13. The substrate processing method according to claim 1, characterized in that each of the above-mentioned multiple types of measurement conditions has a different wavelength from the light source.

14. The substrate processing method according to claim 1, characterized in that each of the above-mentioned multiple types of measurement conditions has a different irradiation direction of the light from the light source.

15. The substrate processing method according to claim 1, characterized in that each of the above-mentioned multiple types of measurement conditions has a different threshold value for light intensity that can be measured by the light receiving unit.

16. The substrate processing method according to claim 1, characterized in that the specified step identifies the plurality of candidates by applying each of the plurality of algorithms to the plurality of measurement results measured in the first measurement step.

17. A processing step of processing a substrate using the substrate processing method described in any one of claims 1 to 16, A forming step of forming a pattern on the substrate that has undergone the processing step, A manufacturing process for producing an article from the substrate obtained through the above formation process, A method for manufacturing articles, characterized by including the following:

18. A substrate processing apparatus for processing substrates, A measuring unit that measures the light intensity distribution obtained from the peripheral portion when light is irradiated onto the peripheral portion of the substrate, A control unit for controlling the positioning of the substrate and Equipped with, The substrate processing apparatus is characterized in that the control unit causes the measurement unit to perform the measurement using multiple types of measurement conditions in a single measurement, thereby obtaining multiple types of measurement results, and identifies candidates for the peripheral position of the substrate from each of the multiple types of measurement results.

19. The substrate processing apparatus according to claim 18, characterized in that the measurement unit includes a plurality of light source units and a plurality of light receiving units.

20. A lithography apparatus for forming patterns on a substrate, A substrate processing apparatus according to claim 18 or 19, A forming unit for forming a pattern on the substrate processed by the substrate processing apparatus, A lithography apparatus characterized by comprising the following:

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