Measurement system, substrate processing system, and device manufacturing method

Abstract

To achieve exposure with high throughput and high accuracy without depending on the latest exposure device.SOLUTION: The measurement system 5001 used in the microdevice manufacturing line is provided independently of the exposure apparatus. The measurement system 5001 includes a first measurement device 1001 that obtains position information of a plurality of marks formed on a substrate, and a second measurement device 1002 that obtains position information of a plurality of marks formed on a substrate, and a substrate on which measurement processing is performed by one of the first measurement device and the second measurement device can be subjected to measurement processing by the other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measurement system, a substrate processing system, and a device manufacturing method, and more particularly to a measurement system for use in a microdevice manufacturing line, a substrate processing system including the measurement system, and a device manufacturing method that uses an exposure apparatus that constitutes part of the substrate processing system. [Background technology]

[0002] In the lithography process for manufacturing microdevices such as semiconductor elements, when overlay exposure is performed on a wafer, the wafer may undergo processes such as resist coating, development, etching, CVD (chemical vapor deposition), and CMP (chemical mechanical polishing) that cause distortion in the arrangement of shot areas in the previous layer due to the processes, and this distortion can be a factor in reducing overlay accuracy. In light of this, recent exposure tools have a grid correction function that corrects not only the first-order components of wafer deformation but also nonlinear components of the shot arrangement that occur due to the processes (see, for example, Patent Document 1).

[0003] However, as integrated circuits become increasingly miniaturized, the requirements for overlay accuracy are becoming increasingly stringent, and in order to perform more accurate correction, it is essential to increase the number of sample shot areas in wafer alignment (EGA), that is, to increase the number of marks to be detected.For this reason, in recent years, twin-stage type exposure tools have come to be adopted, which are able to increase the number of sample shot areas while maintaining throughput. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2002 / 0042664 Summary of the Invention [Means for solving the problem]

[0005] According to a first aspect of the present invention, there is provided a measurement system for use in a microdevice manufacturing line, the measurement system including a first measurement device that acquires positional information of a plurality of marks formed on a substrate, and a second measurement device that acquires positional information of a plurality of marks formed on a substrate, and capable of measuring and processing a substrate that has been measured and processed by one of the first measurement device and the second measurement device with the other measurement device.

[0006] According to a second aspect of the present invention, there is provided a substrate processing system comprising: a measurement system according to the first aspect; and an exposure apparatus having a substrate stage on which the substrate is placed after measurement of positional information of the plurality of marks has been completed by at least one of the first measurement apparatus and the second measurement apparatus of the measurement system, and performing alignment measurement on the substrate placed on the substrate stage to obtain positional information of a selected portion of the plurality of marks on the substrate, and exposure to expose the substrate to an energy beam.

[0007] According to a third aspect of the present invention, there is provided a first measurement system and a second measurement system each configured from the measurement system according to the first aspect, and an exposure apparatus having a substrate stage on which a substrate is placed after measurement of positional information of the plurality of marks has been completed by at least one of the first measurement apparatus and the second measurement apparatus of the first measurement system, and performing alignment measurement for acquiring positional information of selected marks among the plurality of marks on the substrate and exposure for exposing the substrate to an energy beam on the substrate placed on the substrate stage, wherein the measurement of positional information of the plurality of marks performed by at least one of the first measurement apparatus and the second measurement apparatus of the first measurement system is performed. The acquisition is performed on a substrate that has undergone at least one process of cleaning, oxidation / diffusion, film formation, etching, ion implantation, and CMP, and before a photosensitive agent is applied for the next exposure; the acquisition of the positional information of the plurality of marks, performed by at least one of the first measurement device and the second measurement device provided in the second measurement system, is performed on a substrate that has undergone exposure by the exposure device and the development process, but before the etching process; and the acquisition of the positional information of the plurality of marks for different substrates by each of the first measurement system and the second measurement system is performed in parallel with alignment measurement and exposure for different substrates by the exposure device.

[0008] According to a fourth aspect of the present invention, there is provided a device manufacturing method including exposing a substrate using an exposure apparatus that forms part of either the substrate processing system according to the second aspect or the substrate processing system according to the third aspect, and developing the exposed substrate. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a substrate processing system according to an embodiment together with other devices used in a microdevice manufacturing line. [Figure 2] 2 is a perspective view showing an external appearance of a measurement system included in the substrate processing system of FIG. 1. FIG. [Figure 3]FIG. 2 is a plan view showing the measurement system of FIG. 1 with the ceiling of the chamber removed. [Figure 4] FIG. 2 is a perspective view showing a schematic configuration of a measurement device that constitutes a part of the measurement system. [Figure 5] Figure 5(A) is a partially omitted front view (viewed from the -Y direction) of the measurement device in Figure 4, and Figure 5(B) is a partially omitted cross-sectional view of the measurement device cut on the XZ plane passing through the optical axis AX1 of the mark detection system. [Figure 6] 1 is a cross-sectional view of the measurement device, with some parts omitted, taken along the YZ plane passing through the optical axis AX1 of the mark detection system. [Figure 7] FIG. 2 is a diagram illustrating the configuration of a second position measurement system. [Figure 8] FIG. 2 is a block diagram showing the input / output relationship of a control device that centrally configures the control system of the measurement device. [Figure 9] FIG. 2 is a diagram schematically showing the configuration of the exposure apparatus shown in FIG. [Figure 10] FIG. 2 is a block diagram showing the input / output relationship of an exposure control device provided in the exposure apparatus. [Figure 11] 10 is a flowchart corresponding to a processing algorithm of a control device 60i when processing one lot of wafers. [Figure 12] 1. FIG. 4 is a diagram schematically showing a process flow of a method for measuring position information (coordinate position information) of X marks and Y marks, which is carried out in the substrate processing system of FIG. [Figure 13] 1. FIG. 4 is a first diagram schematically showing a process flow of the overlay deviation measuring method performed in the substrate processing system of FIG. [Figure 14] 1. FIG. 5 is a second diagram schematically illustrating the process flow of the overlay deviation measuring method performed in the substrate processing system of FIG. [Figure 15] 1A to 1C are diagrams illustrating an example of a manufacturing process for a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment will be described below with reference to Figures 1 to 14. Figure 1 shows a block diagram of a substrate processing system 1000 according to an embodiment used in a manufacturing line for microdevices (e.g., semiconductor devices), together with other apparatuses used in the manufacturing line.

[0011] As shown in FIG. 1 , the substrate processing system 1000 includes an exposure tool 200 and a coater / developer (resist coating / developing tool) 300, which are connected inline. The substrate processing system 1000 also includes a measurement system 5001 and a measurement system 5002. Hereinafter, the coater / developer 300 will be abbreviated as C / D 300. Note that "inline connection" refers to different tools being connected so that the wafer (substrate) transport paths are substantially continuous. In this specification, the terms "inline connection" or "inline connection" are used in this sense. For example, when two different tools are inline connected, wafers (substrates) processed in one tool can be sequentially transported to the other tool using a transport mechanism such as a robot arm. Note that the term "inline connection" may also be used when different tools are connected via an interface.

[0012] The measurement system 5001 includes three measurement devices 1001 to 1003 arranged adjacent to each other in a predetermined direction in one chamber 502 (see FIGS. 2 and 3), and a measurement system control device 5301 that comprehensively controls the entire measurement system 5001. Each of the measurement devices 1001 to 1003 is controlled by a control device 60. i (i=1 to 3), and the control device 60 i Each of these is connected to the measurement system control device 5301. i (i=1 to 3) may not be provided, and the measurement system control device 5301 may control each of the measurement devices 1001 to 1003.

[0013] The measurement system 5002 includes three measurement devices 1004, 1005, and 1006 arranged adjacent to each other in a predetermined direction in one chamber (not shown), and a measurement system control device 5302 that comprehensively controls the entire measurement system 5002. The measurement devices 1004, 1005, and 1006 each have control devices 604, 605, and 606, and the control device 60 i (i=4 to 6) are each connected to the measurement system control device 5302. i (i=4 to 6) may not be provided, and the measurement system control device 5302 may control each of the measurement devices 1004 to 1006.

[0014] The exposure apparatus 200 and the C / D 300 included in the substrate processing system 1000 each have a chamber, and the chambers are arranged adjacent to each other.

[0015] The exposure control device 220 of the exposure tool 200, the coating and developing control device 320 of the C / D 300, the measurement system control device 5301, and the measurement system control device 5302 are connected to one another via a local area network (LAN) 1500. The LAN 1500 is also connected to a host computer (HOST) 2000 that manages the entire manufacturing line, an analytical device 3000, and a group of devices that perform various process operations (pre-process operations for wafer processing) under the control of the host computer 2000. Of these devices, FIG. 1 shows an etching device 2100, a CMP device 2200, and a film formation device 2300 such as a CVD device as representative examples. In addition, the LAN 1500 is also connected to a cleaning device, an oxidation / diffusion device, an ion implantation device, and the like.

[0016] The substrate processing system 1000 may include at least one of a host computer 2000, an analysis tool 3000, an etching tool 2100, a CMP tool 2200, and a film deposition tool 2300.

[0017] First, the measurement system will be described. Here, measurement system 5001 and measurement system 5002 differ in whether the substrate to be measured is pre-exposed or post-exposed, but they have similar configurations and functions, and therefore measurement system 5001 will be representatively described below. Figure 2 shows an external perspective view of measurement system 5001. Measurement system 5001 is installed on floor F of a clean room, away from the other devices that make up substrate processing system 1000. In other words, measurement system 5001 is not in-line connected to exposure apparatus 200 and C / D 300.

[0018] The measurement system 5001 includes a chamber 502 in which the three measurement devices 1001 to 1003 described above are disposed, and a carrier system 510 disposed on one side of the chamber 502. In this embodiment, the carrier system 510 is an Equipment Front End Module (EFEM) system. Hereinafter, the carrier system 510 will also be referred to as the EFEM system 510.

[0019] As will be described later, the carrier system 510 of this embodiment is for a FOUP (Front-Opening Unified Pod), but it is not limited to a FOUP, and the carrier system 510 may also handle other types of carriers (e.g., SMIF pods) that can accommodate one or more wafers.

[0020] In the following description, the direction in which the chamber 502 and the EFEM system 510 are aligned is defined as the X-axis direction, the direction perpendicular to the X-axis in a plane parallel to the floor surface F is defined as the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis is defined as the Z-axis direction.

[0021] As shown in Fig. 2, the chamber 502 has a rectangular parallelepiped shape, and in the first space inside the chamber 502, the measuring devices 1001 to 1003 are housed side by side in the X-axis direction, as shown in Fig. 3. Fig. 3 shows a plan view of the measuring system 5001 with the ceiling of the chamber 502 removed, and Fig. 3 shows the chambers 101 to 1003 that each have.i (i=1 to 3) are shown. Each of the measuring devices 1001 to 1003 is connected to the chamber 101. i It is not necessary to have the above.

[0022] Since the measurement system 5001 has multiple measurement tools 1001-1003 arranged in the X-axis direction, it can be equipped with multiple measurement tools 1001-1003 without increasing the width of the measurement system 5001 in the Y-axis direction. In a factory where the measurement system 5001 and other systems are installed, an operator's passage extends in the Y-axis direction, and the apparatuses that perform the various processes described above (etching apparatus 2100, CMP apparatus 2200, etc.) are arranged along this passage. Therefore, in order to make effective use of the factory floor space F, it is important to reduce the width of the measurement system 5001 in the Y-axis direction.

[0023] Furthermore, on the -Y side of the first space in chamber 502, a transfer system 521 is disposed, which can transfer wafers to and from each of measuring devices 1001 to 1003. For convenience, hereinafter, the space on the -Y side of the first space in which transfer system 521 is installed will be referred to as the second space. In Fig. 2, the thick dashed line indicates a virtual partition between the first space and the second space.

[0024] An EFEM system 510 is installed on the floor F adjacent to the -X side (front side) of the chamber 502. The EFEM system 510 is a modular device including an EFEM main body 512 with a wafer transport robot installed inside and a load port attached to the -X side (front side) of the EFEM main body 512. The EFEM main body 512 has multiple load ports 514 (which may also be called carrier placement devices) for FOUPs aligned in the Y-axis direction on its front side. In this embodiment, the EFEM main body 512 has three load ports 514, but the number of load ports is not limited to three and may be one, two, four, or more. Here, a FOUP is a carrier for transporting and storing wafers used in mini-environment semiconductor factories, as specified in SEMI Standard E47.1. It is a front-opening, cassette-integrated transport and storage box. In FIGS. 2 and 3, a FOUP 520 is installed on each of the three load ports 514, and at least one wafer is accommodated in the FOUP as a measurement target.

[0025] Although not shown in the drawings, in this embodiment, track rails for an overhead hoist transport (OHT) are provided near the ceiling of the clean room directly above the three load ports 514. The OHT is an automated guided vehicle that travels in the space at ceiling level, and the FOUP 520 is carried onto the load port 514 by this OHT.

[0026] Each of the three load ports 514 has a placement section 515 and an opening / closing mechanism 518 (see FIG. 3) that opens and closes the cover of a FOUP 520 placed on the placement section 515. The opening / closing mechanism 518 is provided in the front portion of the EFEM main body 512 facing the FOUP 520 placed on the placement section 515 of the load port 514, and is capable of opening and closing the cover of the FOUP 520 while keeping the inside of the FOUP 520 airtight from the outside. This type of opening / closing mechanism is well known, so a description of the configuration of the opening / closing mechanism 518 will be omitted.

[0027] Inside the EFEM main body 512, a wafer transfer robot 516 (see FIG. 3) is installed that can access the inside of the three FOUPs with their covers open in order to load and unload wafers. An FFU (Fan Filter Unit, not shown) for maintaining the cleanliness of the inside of the EFEM main body 512 may be installed above the EFEM main body 512, and temperature-controlled air from an air conditioner may be sent into the inside of the EFEM main body 512 via the FFU. A buffer that uses temperature-controlled air from the air conditioner to stabilize the temperature of the wafers may be installed inside the EFEM main body 512.

[0028] An opening is formed in a portion of the back side of the EFEM main body 512 that faces the second space of the chamber 502, and the opening is adapted to be opened and closed by an opening and closing member.

[0029] Each component of the EFEM system 510 (robot 516, opening / closing mechanism 518, etc.) is controlled by a measurement system control device 5301 (see FIG. 1).

[0030] 3, a transfer system 521 is installed inside the second space of chamber 502. Guides 522A and 522B are arranged on one side and the other side of the Y-axis direction in the second space and extend in the X-axis direction over almost the entire length of chamber 502, a loading transfer member 524 that can reciprocate along guide 522A, and an unloading transfer member 526 that can reciprocate along guide 522B.

[0031] The loading conveying member 524 can be moved along the guide 522A by a linear motor (referred to as linear motor 522A using the same reference numeral as the guide incorporating the stator) having a stator built into the guide 522A and a mover provided on the conveying member 524. The unloading conveying member 526 can be moved along the guide 522B by a linear motor (referred to as linear motor 522B using the same reference numeral as the guide incorporating the stator) having a stator built into the guide 522B and a mover provided on the conveying member 526. The linear motors 522A and 522B are controlled by the measurement system control device 5301. The conveying members 524 and 526 may be moved in a non-contact manner using an air slider or the like. The drive mechanism for moving the conveying members 524 and 526 is not limited to the linear motors (522A and 522B) described above, but may be configured using a rotary motor and a ball screw mechanism.

[0032] Guide 522A is disposed at a higher position than guide 522B, so that transport member 524 for loading moves in the space above transport member 526 for unloading.

[0033] In the above-described transfer system 521, the transfer member 524 and the guide 522A may be used for loading and unloading the wafer, and the transfer member 526 and the guide 522B may be used for loading and unloading the wafer.

[0034] Furthermore, although the above-described transfer system 521 is capable of transferring wafers to and from each of the multiple measuring tools 1001 to 1003, the transfer system 521 may alternatively have a transfer device (including a guide and a transfer member) that transfers wafers to and from only the measuring tool 1001, a transfer device (including a guide and a transfer member) that transfers wafers to and from only the measuring tool 1002, or a transfer device (including a guide and a transfer member) that transfers wafers to and from only the measuring tool 1003. In this case, each of the transfer devices may have a guide and a transfer member for loading, and a guide and a transfer member for unloading, or may have a guide and a transfer member that are used for both loading and unloading.

[0035] As shown in FIG. 3, the measurement device 100 i (i=1 to 3) includes a wafer transport system 70 having an articulated robot that transfers wafers between the transport member 524 and the transport member 526. i (i=1 to 3) are provided. i (i=1 to 3) are chambers 101 i The wafer is transferred between the transport member 524 and the transport member 526 through this opening.

[0036] The transport member 524 receives the wafer to be measured in the FOUP 520 from the robot 516 at a wafer transfer position (load side wafer transfer position) set near the boundary between the EFEM main body 512 and the chamber 502, and transfers it to the wafer transport system 70. i (i = 1 to 3) measurement device 100 i The wafer is transported to the wafer transfer position. i In this embodiment, the wafers to be measured (i=1 to 3) are wafers on which at least the first layer has been exposed, and after development, necessary processing has been completed among the pre-processing steps of the wafer process, such as etching, oxidation / diffusion, film formation, ion implantation, and planarization (CMP), and which have not yet been transported into C / D 300 for resist coating.

[0037] When the same wafer is measured by at least two of the measuring devices 1001 to 1003, the loading conveying member 524 is used for the other measuring devices 100. i (i=1 to 3) The wafer to be measured is transferred to the wafer transfer system 70 i (i=1 to 3) and receives it from the wafer transfer system 70 j (j = 1 to 3, j ≠ i) j The wafer is then transported to the wafer transfer position.

[0038] The transport member 526 is connected to the wafer transport system 70 iThe wafer for which measurement has been completed is received from the EFEM main body 512 (i = 1 to 3) and transported to the unload side wafer transfer position (a position below the load side wafer transfer position mentioned above) set near the boundary between the EFEM main body 512 and the chamber 502.

[0039] The robot 516 carries (returns) the measurement-processed wafer, which has been transported by the transport member 526 to the unload-side wafer transfer position, into the FOUP 520.

[0040] Returning to FIG. 1, in this embodiment, measuring devices having the same configuration are used as the measuring devices 1001 to 1003.

[0041] In this embodiment, the measuring device 100, such as the conveying member 524 and the conveying member 526, i In the above example, the transport system 521 for transferring the wafer to and from the chamber 502 is disposed in the second space of the chamber 502, and as a result, the space in which the wafer is transported by the transport members 524 and 526 becomes an airtight space. However, the present invention is not limited to this. The three measuring devices 1001 to 1003 may be disposed side by side on the floor F, and another chamber may be provided next to these measuring devices 1001 to 1003 (whether or not they are housed in the same chamber), with the airtight chamber in which the transport system 521 is housed formed inside. In other words, the measuring system 5001 does not have to be equipped with the chamber 502.

[0042] In addition, instead of the transport members 524 and 526, an articulated robot capable of reciprocating along a guide may be used. In this case, the wafer transport system 70 i The transfer system 521 does not need to be equipped with an articulated robot, but may be equipped with a wafer holder for loading and a wafer holder for unloading, which transfer wafers to and from the articulated robot of the transfer system 521.

[0043] Furthermore, if an articulated robot is used instead of the transport members 524 and 526, the EFEM system 510 does not need to include the robot 516. In this case, the articulated robot of the transport system 521 may take wafers out of the FOUP 520 and return wafers to the FOUP 520.

[0044] Here, the measurement device 100 i FIG. 4 shows the measurement device 100. i The configuration of the measurement device 100 shown in FIG. i In fact, the aforementioned chamber 101 i and the chamber 101 i The chamber 101 is made up of components housed inside the chamber 101. i The measurement device 100 according to this embodiment will be omitted. i In the following description, it is assumed that the direction of the optical axis AX1 of the mark detection system MDS coincides with the Z-axis direction, that the direction in which a movable stage (described later) moves over a long stroke in an XY plane perpendicular to the Z-axis direction coincides with the Y-axis direction, and that the directions of rotation (tilt) about the X-axis, Y-axis, and Z-axis are referred to as the θx, θy, and θz directions, respectively. Here, the mark detection system MDS has a cylindrical lens barrel 41 at its lower end (tip), and the lens barrel 41 houses an optical system (refractive optical system) consisting of multiple lens elements with a common optical axis AX1 in the Z-axis direction. For ease of explanation, the optical axis AX1 of the refractive optical system inside the lens barrel 41 is referred to as the optical axis AX1 of the mark detection system MDS.

[0045] FIG. 5A shows the measurement device 100 of FIG. i 5B shows a cross section of the measurement device 100 taken along the XZ plane passing through the optical axis AX1. i 6 shows a cross-sectional view of the measurement device 100 cut along the YZ plane passing through the optical axis AX1. i 1 is a partially omitted cross-sectional view of the device.

[0046] Measuring Device 100 i As shown in FIG. 4, the wafer slider (hereinafter simply referred to as slider) 10 is arranged on the surface plate 12 and is movable relative to the surface plate 12 in the X-axis and Y-axis directions by a predetermined stroke while holding a wafer W, and is also capable of minute movement (minute displacement) in the Z-axis, θx, θy, and θz directions, as well as a drive system 20 (see FIG. 8) that drives the slider 10, and a first position measurement system 30 (see FIG. 9) that measures position information of the slider 10 relative to the surface plate 12 in each of the X-axis, Y-axis, Z-axis, θx, θy, and θz directions (hereinafter referred to as six degrees of freedom directions). 4, not shown, see FIGS. 6 and 8), a measurement unit 40 having a mark detection system MDS for detecting marks on the wafer W mounted (held) on the slider 10, a second position measurement system 50 (see FIG. 8) for measuring relative position information between the mark detection system MDS (measurement unit 40) and the surface plate 12, and a control device 60 for acquiring measurement information by the first position measurement system 30 and measurement information by the second position measurement system 50 while controlling the driving of the slider 10 by the drive system 20, and determining position information of a plurality of marks on the wafer W held by the slider 10 using the mark detection system MDS. i (not shown in FIG. 4, see FIG. 8).

[0047] The surface plate 12 is made of a rectangular (or square) parallelepiped member in a plan view, and its top surface is finished to have a very high degree of flatness, forming a guide surface for the movement of the slider 10. The material used for the surface plate 12 is a material with a low thermal expansion coefficient, also known as a zero-expansion material, such as an invar alloy, extremely low-expansion cast steel, or extremely low-expansion glass ceramics.

[0048] The surface plate 12 has three notched voids 12a with open bottoms formed in it: one in the center of the -Y side surface in the X-axis direction, and one each at both ends of the +Y side surface in the X-axis direction. Figure 4 shows the voids 12a formed on the -Y side surface. A vibration isolation device 14 is disposed inside each void 12a. The surface plate 12 is supported at three points on the top surface of a rectangular base frame 16, which is installed on the floor F and parallel to the XY plane, by the three vibration isolation devices 14, so that the top surface is approximately parallel to the XY plane. The number of vibration isolation devices 14 is not limited to three.

[0049] 6, the slider 10 has four air hydrostatic bearings (air bearings) 18 attached to each of the four corners of the bottom surface, with the bearing surfaces of each air bearing attached to the bottom surface of the slider 10 in a manner that is approximately flush with the bottom surface of the slider 10. The slider 10 is supported in a floating state above the top surface of the base plate 12 via a predetermined clearance (air gap), for example, a clearance of about several μm, due to the static pressure (gap pressure) between the bearing surfaces of the pressurized air ejected from these four air bearings 18 toward the base plate 12 and the top surface (guide surface) of the base plate 12. In this embodiment, the slider 10 is made of zero-expansion glass (for example, Zerodur by Schott Corporation), which is a type of zero-expansion material.

[0050] A recess 10a, which is circular in plan view and has a predetermined depth and an inner diameter slightly larger than the diameter of the wafer W, is formed in the upper part of the slider 10. A wafer holder WH, which has approximately the same diameter as the wafer W, is disposed inside the recess 10a. The wafer holder WH may be a vacuum chuck, electrostatic chuck, or mechanical chuck, but as an example, a pin-type vacuum chuck is used. The wafer W is attracted and held by the wafer holder WH with its upper surface approximately flush with the upper surface of the slider 10. The wafer holder WH has a plurality of suction ports formed therein, which are connected to a vacuum pump 11 (see FIG. 8) via a vacuum piping system (not shown). The on / off operation of the vacuum pump 11 is controlled by a control device 60. iIt should be noted that either or both of the slider 10 and the wafer holder WH may be referred to as a "first substrate holding member."

[0051] The slider 10 moves up and down through, for example, three circular openings formed in the wafer holder WH, and is connected to the wafer transfer system 70. i A vertically moving member (not shown) is provided to cooperate with the wafer holder WH (not shown in FIG. 4, see FIG. 8) to load a wafer onto the wafer holder WH and unload the wafer from the wafer holder WH. A drive device 13 for driving the vertically moving member is controlled by a control device 60. i (See Figure 8)

[0052] In this embodiment, the wafer holder WH is assumed to be, for example, a holder having a size capable of suction-holding a 300 mm wafer having a diameter of 300 mm. i If the slider 10 has a non-contact holding member, such as a Bernoulli chuck, that holds the wafer on the wafer holder WH from above by suction without contact, there is no need to provide a vertically moving member on the slider 10, and there is no need to form a circular opening in the wafer holder WH for the vertically moving member.

[0053] 5(B) and 6, a two-dimensional grating (hereinafter simply referred to as the grating) RG1 is arranged horizontally (parallel to the surface of the wafer W) in an area on the underside of the slider 10 that is slightly larger than the wafer W. The grating RG1 includes a reflective diffraction grating (X diffraction grating) whose periodic direction is in the X-axis direction, and a reflective diffraction grating (Y diffraction grating) whose periodic direction is in the Y-axis direction. The pitch of the grating lines of the X diffraction grating and the Y diffraction grating is set to, for example, 1 μm.

[0054] The vibration isolator 14 is an active vibration isolation system (so-called AVIS (Active Vibration Isolation System)) and includes an accelerometer, a displacement sensor (e.g., a capacitance sensor), an actuator (e.g., a voice coil motor), and an air mount that functions as an air damper. The vibration isolator 14 can attenuate relatively high-frequency vibrations using the air mount (air damper), and can also eliminate (control) vibrations using the actuator. Therefore, the vibration isolator 14 can prevent vibrations from being transmitted between the surface plate 12 and the base frame 16. Note that a hydraulic damper may be used instead of the air mount (air damper).

[0055] The reason why actuators are provided in addition to air mounts is that the internal gas pressure in the gas chamber of the air mount is high, so a control response of only about 20 Hz can be ensured, and when high-response control is required, the actuator must be controlled according to the output of an accelerometer (not shown) etc. However, minute vibrations such as floor vibrations are absorbed by the air mounts.

[0056] The upper end surface of the vibration isolation device 14 is connected to the surface plate 12. Gas (e.g., compressed air) can be supplied to the air mounts through a gas supply port (not shown), and the air mounts expand and contract in the Z-axis direction by a predetermined stroke (e.g., about 1 mm) depending on the amount of gas (pressure change of the compressed air) filled inside. Therefore, by individually moving three points of the surface plate 12 up and down from below using the air mounts of each of the three vibration isolation devices 14, the positions of the surface plate 12 and the slider 10 levitated and supported thereon can be arbitrarily adjusted in the Z-axis, θx, and θy directions. Furthermore, the actuator of the vibration isolation device 14 can drive the surface plate 12 not only in the Z-axis direction but also in the X-axis and Y-axis directions. Note that the drive amount in the X-axis and Y-axis directions is smaller than the drive amount in the Z-axis direction. The three vibration isolation devices 14 are controlled by a control device 60. i(See FIG. 8). Each of the three vibration isolation devices 14 may be provided with an actuator that can move the surface plate 12 in directions with six degrees of freedom, not limited to the X-axis, Y-axis, and Z-axis directions. i Based on the relative position information between the mark detection system MDS (measurement unit 40) and the surface plate 12 measured by the second position measurement system 50, the control unit 60 constantly controls the actuators of the three vibration isolation devices 14 in real time so that the position in the six degrees of freedom of the surface plate 12, to which the head part 32 of the first position measurement system 30 described later is fixed, maintains a desired positional relationship with the mark detection system MDS. Note that each of the three vibration isolation devices 14 may be feedforward controlled. For example, the control unit 60 i Alternatively, each of the three vibration isolation devices 14 may be subjected to feedforward control based on the measurement information of the first position measurement system 30. i The control of the vibration isolator 14 by the vibration isolator 14 will be described in more detail later.

[0057] As shown in FIG. 8, the drive system 20 includes a first drive unit 20A that drives the slider 10 in the X-axis direction, and a second drive unit 20B that drives the slider 10 integrally with the first drive unit 20A in the Y-axis direction.

[0058] 4 and 6, a pair of movers 22a, each consisting of a magnet unit (or coil unit) and shaped like an inverted L in side view, are fixed at a predetermined distance in the X-axis direction to the -Y-side side surface of slider 10. As shown in Fig. 6, a pair of movers 22b (the +X-side mover 22b is not shown) each consisting of a magnet unit (or coil unit) are fixed at a predetermined distance in the X-axis direction to the +Y-side side surface of slider 10. The pair of movers 22a and the pair of movers 22b are arranged symmetrically but are configured identically.

[0059] 4 to 6, the movers 22a and 22b are arranged at a predetermined distance in the Y-axis direction and constitute part of a movable stage 24 having a rectangular frame shape in a plan view, and are supported in a non-contact manner on the upper surfaces of a pair of plate members 24a and 24b extending in the X-axis direction, which are substantially parallel to the XY plane. That is, air bearings (not shown) are provided on the lower surfaces (surfaces facing the plate members 24a and 24b, respectively) of the movers 22a and 22b, and the movers 22a and 22b are supported in a non-contact manner from below by the movable stage 24 due to the levitation forces (static pressure of pressurized air) generated by these air bearings against the plate members 24a and 24b. The weight of the slider 10 to which each pair of movers 22a and 22b is fixed is supported by the levitation forces generated by the four air bearings 18 against the surface plate 12, as described above.

[0060] As shown in FIGS. 4 to 6, stators 26a and 26b each made up of a coil unit (or magnet unit) are arranged on the upper surface of each of the pair of plate members 24a and 24b in an area excluding both ends in the X-axis direction.

[0061] Electromagnetic interaction between the pair of movers 22a and the stator 26a generates a driving force (electromagnetic force) that drives the pair of movers 22a in the X-axis direction and a driving force (electromagnetic force) that drives the pair of movers 22a in the Y-axis direction, and electromagnetic interaction between the pair of movers 22b and the stator 26b generates a driving force (electromagnetic force) that drives the pair of movers 22b in the X-axis direction and a driving force (electromagnetic force) that drives the pair of movers 22b in the Y-axis direction. That is, the pair of movers 22a and the stator 26a constitute an XY linear motor 28A that generates driving forces in the X-axis direction and the Y-axis direction, the pair of movers 22b and the stator 26b constitute an XY linear motor 28B that generates driving forces in the X-axis direction and the Y-axis direction, and the XY linear motor 28A and the XY linear motor 28B constitute a first driving device 20A that drives the slider 10 by a predetermined stroke in the X-axis direction and slightly drives the slider 10 in the Y-axis direction (see FIG. 8). The first driving device 20A can drive the slider 10 in the θz direction by varying the magnitude of the driving force in the X-axis direction generated by the XY linear motor 28A and the XY linear motor 28B. i In this embodiment, the first driving device 20A, together with the second driving device described below, constitutes a coarse / fine movement driving system that drives the slider 10 in the Y-axis direction, so the first driving device 20A generates a driving force not only in the X-axis direction but also in the Y-axis direction, but the first driving device 20A does not necessarily have to generate a driving force in the Y-axis direction.

[0062] The movable stage 24 includes a pair of plate members 24a, 24b and a pair of connecting members 24c, 24d that are spaced a predetermined distance apart in the X-axis direction and extend in the Y-axis direction. Steps are formed at both ends of the connecting members 24c, 24d in the Y-axis direction. The connecting members 24c, 24d and the plate member 24a are integrated with each other by placing one end and the other longitudinal end of the plate member 24a on the -Y-side step portions of the connecting members 24c, 24d, respectively. The connecting members 24c, 24d and the plate member 24b are integrated with each other by placing one end and the other longitudinal end of the plate member 24b on the +Y-side step portions of the connecting members 24c, 24d, respectively (see FIG. 5B). In other words, the pair of plate members 24a, 24b are connected by the pair of connecting members 24c, 24d, thereby forming the rectangular frame-shaped movable stage 24.

[0063] As shown in FIGS. 4 and 5A, a pair of linear guides 27a, 27b extending in the Y-axis direction are fixed to the upper surface of base frame 16 near both ends in the X-axis direction. One linear guide 27a, located on the +X side, houses a stator 25a (see FIG. 5B) of a Y-axis linear motor 29A, which is comprised of a coil unit (or magnet unit) extending over substantially the entire length in the Y-axis direction near the top and −X-side surfaces. Facing the top and −X-side surfaces of linear guide 27a, a mover 23a, which is comprised of a magnet unit (or coil unit) with an L-shaped cross section and which constitutes Y-axis linear motor 29A together with stator 25a, is disposed. Air bearings that eject pressurized air toward the opposing surfaces are fixed to the bottom and +X-side surfaces of mover 23a, respectively, facing the top and −X-side surfaces of linear guide 27a. A vacuum preload air bearing is used as the air bearing fixed to the +X-side surface of mover 23a. This vacuum preload type air bearing maintains a constant clearance (gap) in the X-axis direction between the mover 23a and linear guide 27a by balancing the static pressure of the pressurized air between the bearing surface and the -X side surface of linear guide 27a and the vacuum preload.

[0064] Multiple X guides 19, for example two rectangular parallelepiped members, are fixed on the upper surface of mover 23a at a specified distance in the Y axis direction. Slide member 21, which has an inverted U-shaped cross section and constitutes a uniaxial guide device together with X guide 19, is engaged without contact with each of the two X guides 19. Air bearings are provided on each of the three surfaces of slide member 21 facing X guide 19.

[0065] As shown in FIG. 4, the two slide members 21 are each fixed to the lower surface (the surface on the -Z side) of the connecting member 24c.

[0066] The other linear guide 27b, located on the -X side, houses a stator 25b of a Y-axis linear motor 29B, which is composed of a coil unit (or magnet unit), and is configured similarly to linear guide 27a, though symmetrical (see FIG. 5B). Facing the top and +X sides of linear guide 27b, a mover 23b is located. The mover 23b is symmetrical but composed of a magnet unit (or coil unit) with an L-shaped cross section similar to that of mover 23a, and together with stator 25b, constitutes Y-axis linear motor 29B. Air bearings are fixed to the bottom and -X sides of mover 23b, facing the top and +X sides of linear guide 27b, respectively. In particular, a vacuum preload air bearing is used as the air bearing fixed to the -X side of mover 23b. This vacuum preload air bearing maintains a constant clearance (gap) in the X-axis direction between mover 23b and linear guide 27b.

[0067] Between the top surface of mover 23b and the bottom surface of connecting member 24d, two uniaxial guide devices each made up of X guide 19 and slide member 21 that engages with X guide 19 without contact are provided, as described above.

[0068] The movable stage 24 is supported from below by movers 23a and 23b via two uniaxial guide devices each on the +X side and the -X side (four in total), and is movable in the X-axis direction on the movers 23a and 23b. Therefore, when the slider 10 is driven in the X-axis direction by the first drive unit 20A described above, a reaction force of the driving force acts on the movable stage 24, on which the stators 26a and 26b are provided, and the movable stage 24 moves in the opposite direction to the slider 10 in accordance with the law of conservation of momentum. In other words, the movement of the movable stage 24 prevents (or effectively suppresses) the generation of vibrations caused by the reaction force of the driving force in the X-axis direction on the slider 10. In other words, the movable stage 24 functions as a countermass when the slider 10 moves in the X-axis direction. However, the movable stage 24 does not necessarily have to function as a countermass. Since the slider 10 only moves slightly in the Y-axis direction relative to the movable stage 24, no counter mass is provided, but a counter mass may be provided to prevent (or effectively suppress) the generation of vibrations caused by the driving force that drives the slider 10 in the Y-axis direction relative to the movable stage 24.

[0069] Y-axis linear motor 29A generates a driving force (electromagnetic force) that drives mover 23a in the Y-axis direction through electromagnetic interaction between mover 23a and stator 25a, and Y-axis linear motor 29B generates a driving force (electromagnetic force) that drives mover 23b in the Y-axis direction through electromagnetic interaction between mover 23b and stator 25b.

[0070] The driving force in the Y-axis direction generated by Y-axis linear motors 29A, 29B acts on movable stage 24 via two uniaxial guide devices on each of the +X and -X sides. This drives slider 10 in the Y-axis direction integrally with movable stage 24. That is, in this embodiment, second driving device 20B (see FIG. 8) that drives slider 10 in the Y-axis direction is configured by movable stage 24, four uniaxial guide devices, and a pair of Y-axis linear motors 29A, 29B.

[0071] In this embodiment, the pair of Y-axis linear motors 29A, 29B are physically separated from the base plate 12, and are also vibrationally separated by three vibration isolation devices 14. Note that linear guides 27a, 27b, on which stators 25a, 25b of the pair of Y-axis linear motors 29A, 29B are respectively provided, may be configured to be movable in the Y-axis direction relative to the base frame 16, and may function as a counter mass when the slider 10 is driven in the Y-axis direction.

[0072] As shown in Figure 4, measurement unit 40 has a unit main body 42 in which a notched cavity 42a with an open bottom is formed on the -Y side surface, the above-mentioned mark detection system MDS connected to unit main body 42 with its base end inserted into cavity 42a, and a connection mechanism 43 that connects the lens barrel portion 41 at the tip of mark detection system MDS to unit main body 42.

[0073] The connection mechanism 43 includes a support plate 44 that supports the telescope tube portion 41 on the back side (+Y side) via an attachment member not shown, and a pair of support arms 45a, 45b that support the support plate 44 at one end and have the other end fixed to the bottom surface of the unit main body 42.

[0074] In this embodiment, the mark detection system MDS is an FIA (Field Image Alignment) system, which is an image processing system that irradiates a target mark with a broadband detection light beam generated by an illumination light source such as a halogen lamp, captures an image of the target mark formed on a light receiving surface by the light reflected from the target mark and an image of an index (index pattern on an index plate provided inside) (not shown) using an image pickup element (CCD, etc.), and outputs image pickup signals from these. The image pickup signals from the mark detection system MDS are sent to a control device 60 via a signal processing device 49 (not shown in FIG. 4, see FIG. 8). i (See FIG. 8.) iIn the system, the measurement conditions (also called alignment measurement conditions) of the mark using the mark detection system MDS can be switched (selected) and set. The alignment measurement conditions that can be switched (selected) and set include irradiation conditions for irradiating the mark to be detected with detection light, light receiving conditions for receiving the light emitted from the mark, and signal processing conditions for processing the photoelectric conversion signal obtained by receiving the light emitted from the mark. The irradiation conditions and light receiving conditions are set by the control device 60. i The signal processing conditions are switched and set by the control device 60 via the mark detection system MDS. i The signal is switched and set via the signal processor 49 by the

[0075] The illumination conditions that can be switched include, for example, at least one of the wavelength, light amount, and NA or σ of the detection light irradiated onto the mark from the optical system of the mark detection system MDS. The light receiving conditions that can be switched include at least one of the order of the diffracted light generated from the mark and the wavelength of the light generated from the mark.

[0076] For example, the wavelength of the detection light (illumination light) can be selected by selectively setting a filter used in the wavelength selection mechanism of the mark detection system MDS on the optical path of the illumination light from the illumination light source. Also, by controlling the settings or aperture states of the illumination field stop, illumination aperture stop, and imaging aperture stop (including, for example, an imaging aperture stop with an annular light-shielding portion used in combination with an annular illumination aperture stop) of the mark detection system MDS, it is possible to set and control the illumination conditions (normal illumination / modified illumination), dark-field / bright-field detection method, numerical aperture NA, σ, illumination light intensity, etc. of the optical system.

[0077] The signal processing conditions that can be switched include at least one of the following: a waveform analysis (waveform processing) algorithm used in the signal processing device 49, a selection of a signal processing algorithm such as an EGA calculation model, and a selection of various parameters to be used in each selected signal processing algorithm.

[0078] An FIA system capable of switching (selecting) such alignment measurement conditions is disclosed, for example, in U.S. Patent Application Publication No. 2008 / 0013073, and an FIA system with a similar configuration can be used in the mark detection system MDS of this embodiment. This U.S. Patent Application Publication also discloses that the illumination aperture stop is changed from a conventional illumination aperture stop with a circular transmission portion to an illumination aperture stop with an annular transmission portion, and a phase difference plate is placed in a position adjacent to the imaging aperture stop downstream of the imaging aperture stop, thereby causing the FIA ​​system (alignment sensor) to function as a phase-contrast microscope-type sensor, thereby imparting a predetermined phase difference to diffracted light of a predetermined order generated from the mark as one of the light receiving conditions. In this embodiment, the mark detection system MDS also has an alignment autofocus function that adjusts the focal position of the optical system.

[0079] Returning to the explanation of Figure 4, a head mounting member 51 having a roughly isosceles triangle shape is disposed between the lens barrel 41 and the support plate 44. An opening penetrating the head mounting member 51 in the Y-axis direction of Figure 4 is formed in the head mounting member 51, and the lens barrel 41 is mounted (fixed) to the support plate 44 via a mounting member (not shown) inserted into this opening. The back surface of the head mounting member 51 is also fixed to the support plate 44. In this way, the lens barrel 41 (mark detection system MDS), head mounting member 51, and support plate 44 are integrated with the unit main body 42 via a pair of support arms 45a, 45b.

[0080] Inside the unit body 42, an image pickup signal output as a detection signal from the mark detection system MDS is processed to calculate position information of the target mark relative to the detection center, and a control device 60 iThe unit body 42 is supported at three points from below on a support frame 46 that is shaped like a gate when viewed from the -Y side and is installed on the base frame 16, via multiple (for example, three) vibration isolation devices 48. Each vibration isolation device 48 is an active vibration isolation system (so-called AVIS (Active Vibration Isolation System)) and includes an accelerometer, a displacement sensor (for example, a capacitance sensor), an actuator (for example, a voice coil motor), and a mechanical damper such as an air damper or a hydraulic damper. Each vibration isolation device 48 can attenuate relatively high-frequency vibrations using the mechanical damper and can also isolate (control) vibrations using the actuator. Therefore, each vibration isolation device 48 can prevent relatively high-frequency vibrations from being transmitted between the support frame 46 and the unit body 42.

[0081] The mark detection system MDS is not limited to an FIA system. For example, a diffracted light interference type alignment detection system may be used instead of the FIA ​​system. The diffracted light interference type alignment detection system irradiates a target mark with coherent detection light, detects two diffracted lights (e.g., diffracted lights of the same order or diffracted lights diffracted in the same direction) generated from the target mark by causing them to interfere with each other and output a detection signal. Alternatively, a diffracted light interference type alignment system may be used together with the FIA ​​system to simultaneously detect two target marks. Furthermore, the mark detection system MDS may be a beam scanning type alignment system that scans the target mark with measurement light in a predetermined direction while the slider 10 is moving in a predetermined direction. In addition, although the mark detection system MDS has an alignment autofocus function in this embodiment, the measurement unit 40 may instead or in addition be equipped with a focus position detection system, such as an oblique incidence type multi-point focus position detection system having a configuration similar to that disclosed in U.S. Pat. No. 5,448,332.

[0082] 5(B) and 6, the first position measurement system 30 is disposed in a recess formed in the upper surface of the surface plate 12 and has a head unit 32 fixed to the surface plate 12. The upper surface of the head unit 32 faces the lower surface of the slider 10 (the surface on which the grating RG1 is formed). A predetermined clearance (gap), for example, a clearance of about several mm, is formed between the upper surface of the head unit 32 and the lower surface of the slider 10.

[0083] 8, the first position measurement system 30 includes an encoder system 33 and a laser interferometer system 35. The encoder system 33 irradiates a measurement unit (the surface on which the grating RG1 is formed) on the underside of the slider 10 with multiple beams from a head unit 32 and receives multiple return beams (e.g., multiple diffracted beams from the grating RG1) from the measurement unit on the underside of the slider 10, thereby acquiring position information of the slider 10. The encoder system 33 includes an X linear encoder 33x that measures the position of the slider 10 in the X-axis direction, and a pair of Y linear encoders 33ya and 33yb that measure the position of the slider 10 in the Y-axis direction. The encoder system 33 uses a diffraction interference type head having a configuration similar to that of an encoder head (hereinafter simply referred to as a head, as appropriate) disclosed in, for example, U.S. Patent Application Publication No. 2007 / 288121. The head includes a light source, a light receiving system (including a photodetector), and an optical system, but in this embodiment, it is sufficient that at least the optical system is arranged inside the housing of the head unit 32 facing the grating RG1, and at least one of the light source and the light receiving system may be arranged outside the housing of the head unit 32.

[0084] In this embodiment, the first position measurement system 30 (encoder system 33) has a common detection point for measuring the position information of the slider 10 in the X-axis direction and the Y-axis direction, and the control device 60 controls the position of this detection point in the XY plane so that it coincides with the detection center of the mark detection system MDS, for example, at the nm level. iThe actuators of the three vibration isolation apparatuses 14 are controlled in real time by the control device 60. The control of the actuators of the three vibration isolation apparatuses 14 is performed based on relative position information between the mark detection system MDS (measurement unit 40) and the surface plate 12 measured by the second position measurement system 50. Therefore, in this embodiment, the control device 60 i By using the encoder system 33, when measuring the alignment mark on the wafer W placed on the slider 10, the position information of the slider 10 in the XY plane can always be measured directly below the detection center of the mark detection system MDS (on the back side of the slider 10). i measures the amount of rotation of slider 10 in the θz direction based on the difference between the measurement values ​​of the pair of Y linear encoders 33ya and 33yb.

[0085] The laser interferometer system 35 can acquire position information of the slider 10 by irradiating a measurement beam onto a measurement section on the underside of the slider 10 (the surface on which the grating RG1 is formed) and receiving the return beam (for example, light reflected from the surface on which the grating RG1 is formed). The laser interferometer system 35 irradiates, for example, four measurement beams onto the underside of the slider 10 (the surface on which the grating RG1 is formed). The laser interferometer system 35 includes laser interferometers 35a to 35d (see FIG. 8) that irradiate these four measurement beams, respectively. In this embodiment, the laser interferometers 35a to 35d form four Z heads. The measurement beams from the laser interferometers 35a to 35d are irradiated onto the vertices of a square on the underside of the slider 10 (the surface on which the grating RG1 is formed), with the detection point of the encoder system 33 at its center and two sides parallel to the X-axis and Y-axis, respectively.

[0086] In this embodiment, the surface on which the grating RG1 is formed also serves as a reflecting surface for each measurement beam from the laser interferometer system 35. iThe encoder system 33 uses the laser interferometer system 35 to measure information about the position of the slider 10 in the Z-axis direction and the amount of rotation in the θx and θy directions. As is clear from the above description, the slider 10 is not actively driven by the drive system 20 relative to the surface plate 12 in the Z-axis, θx, and θy directions. However, since the slider 10 is supported by the four air bearings 18 located at the four corners of the bottom surface, the position of the slider 10 actually changes on the surface plate 12 in the Z-axis, θx, and θy directions. In other words, the slider 10 actually moves relative to the surface plate 12 in the Z-axis, θx, and θy directions. In particular, displacement of the slider 10 in the θx and θy directions causes measurement errors (Abbe errors) in the encoder system 33. In consideration of this, the first position measurement system 30 (laser interferometer system 35) measures position information about the slider 10 in the Z-axis, θx, and θy directions.

[0087] In order to measure information about the position of slider 10 in the Z axis direction and the amount of rotation in the θx and θy directions, it is sufficient to make beams incident on three different points on the surface on which grating RG1 is formed, so three Z heads, for example, laser interferometers, are sufficient. Note that a protective glass for protecting grating RG1 may be provided on the underside of slider 10, and a wavelength selection filter may be provided on the surface of the protective glass that allows each measurement beam from encoder system 33 to pass through and blocks each measurement beam from laser interferometer system 35 from passing through.

[0088] As can be seen from the above description, the control device 60 iBy using encoder system 33 and laser interferometer system 35 of first position measurement system 30, the position of slider 10 in six degrees of freedom can be measured. In this case, with encoder system 33, the optical path lengths in air of all measurement beams are extremely short, and the optical path lengths of the pair of measurement beams irradiated from X head 73x to grating RG1, the optical path lengths of the pair of measurement beams irradiated from Y head 37ya to grating RG1, and the optical path lengths of the pair of measurement beams irradiated from Y head 37yb to grating RG1 are all approximately equal, so the influence of air fluctuations can be almost ignored. Therefore, encoder system 33 can measure position information of slider 10 in the XY plane (including the θz direction) with high accuracy. Furthermore, the detection points on the grating RG1 in the X-axis direction and the Y-axis direction by the encoder system 33, and the detection point on the underside of the slider 10 in the Z-axis direction by the laser interferometer system 35, each coincide with the detection center of the mark detection system MDS in the XY plane, so that the occurrence of so-called Abbe error caused by the deviation in the XY plane between the detection points and the detection center of the mark detection system MDS is suppressed to a substantially negligible level. i By using the first position measurement system 30, the positions of the slider 10 in the X-axis, Y-axis, and Z-axis directions can be measured with high accuracy without Abbe error caused by the misalignment in the XY plane between the detection point and the detection center of the mark detection system MDS.

[0089] However, with regard to the Z-axis direction parallel to the optical axis AX1 of mark detection system MDS, encoder system 33 does not measure position information of slider 10 in the XY plane at the position on the surface of wafer W; that is, the Z position of the arrangement surface of grating RG1 does not coincide with that of the surface of wafer W. Therefore, when grating RG1 (i.e., slider 10) is tilted with respect to the XY plane, if slider 10 is positioned based on the measurement values ​​of each encoder of encoder system 33, a positioning error (a kind of Abbe error) corresponding to the tilt of grating RG1 with respect to the XY plane will occur due to the difference ΔZ in the Z position between the arrangement surface of grating RG1 and the surface of wafer W (i.e., the positional deviation in the Z-axis direction between the detection point by encoder system 33 and the detection center (detection point) by mark detection system MDS). However, this positioning error (position control error) can be found by a simple calculation using the difference ΔZ, the pitching amount θx, and the rolling amount θy, and by using this as an offset and positioning the slider 10 based on position information after correcting the measurement value of (each encoder of) the encoder system 33 by the amount of this offset, the influence of the above-mentioned kind of Abbe error can be eliminated. Alternatively, instead of correcting the measurement value of (each encoder of) the encoder system 33, one or more pieces of information for moving the slider, such as a target position where the slider 10 should be positioned, may be corrected based on the above-mentioned offset.

[0090] If the grating RG1 (i.e., the slider 10) is tilted with respect to the XY plane, the head unit 32 may be moved to prevent a positioning error caused by the tilt. That is, if the first position measurement system 30 (e.g., the laser interferometer system 35) measures that the grating RG1 (i.e., the slider 10) is tilted with respect to the XY plane, the surface plate 12 holding the head unit 32 may be moved based on position information acquired using the first position measurement system 30. The surface plate 12 can be moved using the vibration isolation device 14, as described above.

[0091] Furthermore, when the grating RG1 (that is, the slider 10) is tilted with respect to the XY plane, the position information of the mark acquired using the mark detection system MDS may be corrected based on the positioning error caused by the tilt.

[0092] As shown in FIGS. 4, 5A, and 5B, the second position measurement system 50 includes a pair of head units 52A and 52B provided on the underside of one longitudinal end and the other longitudinal end of the head mounting member 51, respectively, and scale members 54A and 54B disposed opposite the head units 52A and 52B. The upper surfaces of the scale members 54A and 54B are flush with the surface of the wafer W held by the wafer holder WH. Reflective two-dimensional gratings RG2a and RG2b are formed on the upper surfaces of the scale members 54A and 54B, respectively. The two-dimensional gratings RG2a and RG2b (hereinafter simply referred to as gratings) each include a reflective diffraction grating (X diffraction grating) whose periodic direction is in the X-axis direction and a reflective diffraction grating (Y diffraction grating) whose periodic direction is in the Y-axis direction. The grating line pitch of the X diffraction grating and the Y diffraction grating is set to, for example, 1 μm.

[0093] The scale members 54A and 54B are made of a material with a low thermal expansion coefficient, such as the zero expansion material described above, and as shown in Figures 5(A) and 5(B), are fixed onto the surface plate 12 via support members 56. In this embodiment, the dimensions of the scale members 54A and 54B and the support member 56 are determined so that the gratings RG2a and RG2b and the head portions 52A and 52B face each other with a gap of about several mm between them.

[0094] 7, one head unit 52A fixed to the underside of the end on the +X side of head mounting member 51 includes an XZ head 58X1 whose measurement directions are in the X-axis and Z-axis directions, and a YZ head 58Y1 whose measurement directions are in the Y-axis and Z-axis directions, both housed inside the same housing. XZ head 58X1 (more precisely, the irradiation point on grating RG2a of the measurement beam emitted by XZ head 58X1) and YZ head 58Y1 (more precisely, the irradiation point on two-dimensional grating RG2a of the measurement beam emitted by YZ head 58Y1) are arranged on the same straight line parallel to the Y axis.

[0095] The other head unit 52B is arranged symmetrically to head unit 52A with respect to a line (hereinafter referred to as the reference axis) LV that is parallel to the Y axis and passes through optical axis AX1 of mark detection system MDS, but is configured similarly to head unit 52A. That is, head unit 52B has XZ head 58X2 and YZ head 58Y2 that are arranged symmetrically to XZ head 58X1 and YZ head 58Y1 with respect to reference axis LV, and the irradiation points of the measurement beams that are irradiated onto grating RG2b from XZ head 58X2 and YZ head 58Y2 are set on the same line that is parallel to the Y axis.

[0096] Head units 52A and 52B use scale members 54A and 54B, respectively, to constitute an XZ linear encoder that measures the position in the X-axis direction (X position) and the position in the Z-axis direction (Z position) of gratings RG2a and RG2b, and a YZ linear encoder that measures the position in the Y-axis direction (Y position) and the Z position. Here, gratings RG2a and RG2b are formed on the upper surfaces of scale members 54A and 54B that are fixed on surface plate 12 via support members 56, and head units 52A and 52B are provided on head mounting member 51 that is integrated with mark detection system MDS. As a result, head units 52A and 52B measure the position of surface plate 12 relative to mark detection system MDS (the positional relationship between mark detection system MDS and surface plate 12). For convenience, the XZ linear encoders and the YZ linear encoders will be referred to as XZ linear encoders 58X1, 58X2 and YZ linear encoders 58Y1, 58Y2 below using the same reference numerals as the XZ heads 58X1, 58X2 and the YZ heads 58Y1, 58Y2, respectively (see FIG. 8).

[0097] In this embodiment, the XZ linear encoder 58X1 and the YZ linear encoder 58Y1 configure a four-axis encoder 581 that measures position information about the X-axis, Y-axis, Z-axis, and θx directions relative to the mark detection system MDS of the surface plate 12 (see FIG. 8). Similarly, the XZ linear encoder 58X2 and the YZ linear encoder 58Y2 configure a four-axis encoder 582 that measures position information about the X-axis, Y-axis, Z-axis, and θx directions relative to the mark detection system MDS of the surface plate 12 (see FIG. 8). In this case, position information about the θy direction relative to the mark detection system MDS of the surface plate 12 is determined (measured) based on position information about the Z-axis direction relative to the mark detection system MDS of the surface plate 12 measured by the four-axis encoders 581 and 582, and position information about the θz direction relative to the mark detection system MDS of the surface plate 12 is determined (measured) based on position information about the Y-axis direction relative to the mark detection system MDS of the surface plate 12 measured by the four-axis encoders 581 and 582.

[0098] Therefore, the four-axis encoder 581 and the four-axis encoder 582 constitute a second position measurement system 50 that measures position information of the surface plate 12 in six degrees of freedom directions with respect to the mark detection system MDS, i.e., information on the relative position between the mark detection system MDS and the surface plate 12 in six degrees of freedom directions. The information on the relative position between the mark detection system MDS and the surface plate 12 in six degrees of freedom directions measured by the second position measurement system 50 is transmitted to the control device 60. i is constantly supplied to the control device 60 i Based on this relative position information, the second position measurement system 50 controls the actuators of the three vibration isolation devices 14 in real time so that the detection point of the first position measurement system 30 has a desired positional relationship with the detection center of the mark detection system MDS, specifically so that the detection point of the first position measurement system 30 matches the position of the detection center of the mark detection system MDS in the XY plane at, for example, nm level, and so that the surface of the wafer W on the slider 10 matches the detection position of the mark detection system MDS. Note that as long as the detection point of the first position measurement system 30 can be controlled so as to have a desired positional relationship with the detection center of the mark detection system MDS, the second position measurement system 50 does not need to be able to measure relative position information in all directions of six degrees of freedom.

[0099] As is clear from the above description of the first position measurement system 30 and the second position measurement system 50, the measurement device 100 i In the example, the first position measurement system 30 and the second position measurement system 50 constitute a position measurement system that measures position information of the slider 10 in six degrees of freedom directions relative to the mark detection system MDS.

[0100] FIG. 8 shows each measurement device 100 of the measurement system 5001. i (i=1 to 3) control system (and each measuring device 100 of the measuring system 5002 described later) i A control device 60 that centrally configures the control system (i=4 to 6) i 1 shows a block diagram illustrating the input / output relationship of the control device 60. i includes a workstation (or a microcomputer) and the like, and the measuring device 100 iAs shown in FIG. 8, the measuring device 100 i The components shown in FIG. 4 are included in the chamber 101. i A wafer transfer system 70 is partially disposed within the i The wafer transfer system 70 i As mentioned above, the robot is, for example, a horizontal articulated robot.

[0101] The measurement system 5002 includes three measurement devices 100 i (i=4 to 6) and a chamber similar to chamber 502 in which a transfer system 521 is housed, and an EFEM system 510 arranged on one side of the chamber, and is configured in the same manner as the measurement system 5001 described above.

[0102] 1, in the present embodiment, the measurement system 5002 is not in-line connected to the exposure apparatus 200 and C / D 300, as is the case with the measurement system 5001, but may be in-line connected to at least one of the exposure apparatus 200 and C / D 300. Although not shown in the drawings, in the present embodiment, a track rail for the OHT is provided near the ceiling of the clean room directly above the three load ports 514 of the EFEM system 510 of the measurement system 5002. The FOUP 520 is carried onto the load port 514 by the OHT. In addition, the three measurement apparatuses 100 provided in the measurement system 5002 i (i=4 to 6) are the measurement devices 100 described above. i It is configured in the same way as (i=1~3).

[0103] The exposure apparatus 200 is, for example, a step-and-scan projection exposure apparatus (scanner). In Fig. 9, the components inside the chamber of the exposure apparatus 200 are shown with some of the components omitted.

[0104] 9, exposure apparatus 200 includes an illumination system IOP, a reticle stage RST that holds reticle R, a projection unit PU that projects an image of a pattern formed on reticle R onto a wafer W coated with a photosensitive agent (resist), a wafer stage WST that holds wafer W and moves within the XY plane, and control systems for these components. Exposure apparatus 200 includes a projection optical system PL that has an optical axis AX that is parallel to the Z-axis direction.

[0105] Illumination system IOP includes a light source and an illumination optical system connected to the light source via a light-transmitting optical system, and illuminates, with approximately uniform illuminance, a slit-shaped illumination area IAR extending in the X-axis direction (a direction perpendicular to the plane of the paper in FIG. 9 ) on reticle R, which is set (limited) by a reticle blind (masking system), with illumination light (exposure light) IL. The configuration of illumination system IOP is disclosed, for example, in U.S. Patent Application Publication No. 2003 / 0025890. Here, as one example, ArF excimer laser light (wavelength 193 nm) is used as illumination light IL.

[0106] Reticle stage RST is disposed below illumination system IOP in Fig. 9. Reticle stage RST can be driven by a reticle stage drive system 211 (not shown in Fig. 9, see Fig. 10) including, for example, a linear motor or the like, to move minutely within a horizontal plane (XY plane) on a reticle stage base (not shown), and can also be driven within a predetermined stroke range in the scanning direction (the Y-axis direction, which is the left-right direction within the plane of the paper in Fig. 9).

[0107] A reticle R is placed on the reticle stage RST. The reticle R has a pattern area and a plurality of marks whose positional relationship with the pattern area is known, formed on its -Z side surface (pattern surface). Position information (including rotation information in the θz direction) of the reticle stage RST in the XY plane is constantly detected by a reticle laser interferometer (hereinafter referred to as "reticle interferometer") 214 via a movable mirror 212 (or a reflecting surface formed on the end surface of the reticle stage RST) with a resolution of, for example, about 0.25 nm. The measurement information of the reticle interferometer 214 is supplied to an exposure control device 220 (see FIG. 10). The position information of the reticle stage RST in the XY plane may be measured by an encoder instead of the reticle interferometer 214.

[0108] The projection unit PU is disposed below the reticle stage RST in FIG. 9. The projection unit PU includes a lens barrel 240 and a projection optical system PL held within the lens barrel 240. The projection optical system PL is, for example, double-telecentric and has a predetermined projection magnification (e.g., 1 / 4, 1 / 5, or 1 / 8). The reticle R is disposed so that the first surface (object surface) of the projection optical system PL and the pattern surface thereof substantially coincide with each other, and a wafer W, whose surface is coated with a resist (sensitizer), is disposed on the second surface (image surface) of the projection optical system PL. Therefore, when an illumination area IAR on the reticle R is illuminated by illumination light IL from the illumination system IOP, the illumination light IL that has passed through the reticle R forms a reduced image of the circuit pattern of the reticle R within the illumination area IAR (a reduced image of a portion of the circuit pattern) in an area IA on the wafer W that is conjugate with the illumination area IAR, via the projection optical system PL. Then, by synchronously driving the reticle stage RST and the wafer stage WST, the reticle R is moved relative to the illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction), and the wafer W is moved relative to the exposure area IA (illumination light IL) in the scanning direction (Y-axis direction), thereby performing scanning exposure of one shot area (divided area) on the wafer W, and the pattern of the reticle R is transferred to that shot area.

[0109] The projection optical system PL is, for example, a refractive system consisting of a plurality of refractive optical elements (lens elements), for example, approximately 10 to 20 elements, arranged along an optical axis AX parallel to the Z-axis direction. Of the lens elements constituting this projection optical system PL, the lens elements on the object plane side (the reticle R side) are movable lenses that can be shifted in the Z-axis direction (the optical axis direction of the projection optical system PL) and tilted relative to the XY plane (i.e., the θx direction and the θy direction) by drive elements (not shown), such as piezoelectric elements. The imaging characteristic correction controller 248 (not shown in FIG. 9 , see FIG. 10 ) independently adjusts the voltages applied to each drive element based on instructions from the exposure control device 220, thereby individually driving each movable lens and adjusting various imaging characteristics of the projection optical system PL (magnification, distortion, astigmatism, coma, field curvature, etc.). Instead of or in addition to moving the movable lens, an airtight chamber may be provided between specific adjacent lens elements inside the lens barrel 240, and the pressure of the gas inside the airtight chamber may be controlled by the imaging characteristics correction controller 248, or the central wavelength of the illumination light IL may be shifted by the imaging characteristics correction controller 248. These configurations also make it possible to adjust the imaging characteristics of the projection optical system PL.

[0110] The wafer stage WST is driven by a stage drive system 224 (shown as a block in FIG. 9 for convenience) including a planar motor or linear motor, etc., over a wafer stage base 222 at a predetermined stroke in the X-axis and Y-axis directions, and is also finely driven in the Z-axis, θx, θy, and θz directions. The wafer W is held on the wafer stage WST by vacuum suction or the like via a wafer holder (not shown). In this embodiment, the wafer holder is capable of suction-holding a 300 mm wafer. Instead of the wafer stage WST, a stage device can also be used that includes a first stage that moves in the X-axis, Y-axis, and θz directions, and a second stage that moves finely on the first stage in the Z-axis, θx, and θy directions. Either the wafer stage WST or the wafer holder of the wafer stage WST, or both, may be referred to as the "second substrate holding member."

[0111] Position information within the XY plane of wafer stage WST (including rotation information (yawing amount (amount of rotation θz in the θz direction), pitching amount (amount of rotation θx in the θx direction), and rolling amount (amount of rotation θy in the θy direction))) is constantly detected by a laser interferometer system (hereinafter abbreviated as interferometer system) 218 ​​via a movable mirror 216 (or a reflective surface formed on the end face of wafer stage WST) with a resolution of, for example, about 0.25 nm. Note that position information within the XY plane of wafer stage WST may also be measured by an encoder system instead of interferometer system 218.

[0112] The measurement information of the interferometer system 218 is supplied to the exposure control device 220 (see FIG. 10). Based on the measurement information of the interferometer system 218, the exposure control device 220 controls the position of the wafer stage WST in the XY plane (including rotation in the θz direction) via a stage drive system 224.

[0113] 9, the position in the Z-axis direction and the tilt amount of the surface of the wafer W are measured by a focus sensor AFS (see FIG. 10) consisting of a multi-point focal position detection system of the oblique incidence type disclosed in, for example, U.S. Patent No. 5,448,332, etc. Measurement information of this focus sensor AFS is also supplied to the exposure control device 220 (see FIG. 10).

[0114] Additionally, a reference plate FP is fixed onto the wafer stage WST, and its surface is at the same height as the surface of the wafer W. On the surface of this reference plate FP, a first reference mark used for baseline measurement of the alignment detection system AS, and a pair of second reference marks detected by a reticle alignment detection system (described later) are formed.

[0115] An alignment detection system AS is provided on the side of the lens barrel 240 of the projection unit PU, which detects alignment marks or first reference marks formed on the wafer W. As alignment detection system AS, for example, an FIA (Field Image Alignment) system is used, which is a type of imaging alignment sensor that uses an image processing method, which illuminates the mark with broadband light from a halogen lamp or the like and measures the mark position by image processing the image of this mark. Note that a diffracted light interference type alignment system may be used instead of, or in addition to, the image processing type alignment detection system AS.

[0116] Furthermore, in exposure apparatus 200, a pair of reticle alignment detection systems 213 (not shown in FIG. 9, see FIG. 10) are provided above reticle stage RST, spaced a predetermined distance apart in the X-axis direction, and are capable of simultaneously detecting a pair of reticle marks at the same Y position on reticle R placed on reticle stage RST. The detection results of the marks by reticle alignment detection systems 213 are supplied to exposure controller 220.

[0117] Figure 10 is a block diagram showing the input / output relationships of exposure control device 220. As shown in Figure 10, in addition to the components described above, exposure apparatus 200 also includes a wafer transfer system 270 that transfers wafers and is connected to exposure control device 220. Exposure control device 220 includes a microcomputer or a workstation, etc., and comprehensively controls the entire apparatus including the components described above. Wafer transfer system 270 is composed of, for example, a horizontal articulated robot.

[0118] Returning to FIG. 1, although not shown, the C / D 300 includes, for example, a coating unit that coats wafers with a sensitizer (resist), a developing unit that can develop wafers, a baking unit that performs a pre-bake (PB) and a post-exposure bake (PEB), and a wafer transfer system (hereinafter referred to as the C / D transfer system for convenience). The C / D 300 also includes a temperature adjustment unit 330 that can adjust the temperature of the wafer. The temperature adjustment unit 330 is typically a cooling unit and includes, for example, a flat plate (temperature adjustment device) called a cool plate. The cool plate is cooled, for example, by circulating cooling water. Alternatively, electronic cooling using the Peltier effect may be used.

[0119] Analysis device 3000 performs various analyses and calculations in response to instructions from host computer 2000. As one example, analysis device 3000 performs calculations in accordance with a predetermined program based on the measurement results of overlay misalignment acquired by measurement system 5002, as will be described later, to calculate a correction value to be fed back to exposure apparatus 200.

[0120] In the substrate processing system 1000 according to this embodiment, the exposure apparatus 200 and the C / D 300 are both equipped with barcode readers (not shown), and while the wafer is being transported by the wafer transport system 270 (see FIG. 10) and the intra-C / D transport system (not shown), the barcode readers appropriately read the identification information of each wafer, such as the wafer number, lot number, etc. In the following, for the sake of simplicity, the description of reading the identification information of each wafer using a barcode reader will be omitted.

[0121] Next, in the three measuring tools 1001 to 1003 of one measuring system 5001, when processing a plurality of wafers (for example, 25 wafers) included in the same lot, the respective measuring tools 100 i Regarding the operation of the measuring device 100 i Control device 60 i11 corresponding to the processing algorithm. Here, as an example, of 25 wafers in the same lot, measuring tool 1001 is responsible for measuring 9 wafers, measuring tool 1002 is responsible for measuring 8 wafers, and measuring tool 1003 is responsible for measuring 8 wafers. Note that multiple wafers (25 wafers) included in the same lot may be allocated to two measuring tools among measuring tool 1001, measuring tool 1002, and measuring tool 1003. Furthermore, as described above, the allocation of multiple wafers included in the same lot may or may not be approximately equal.

[0122] As a premise, the measurement device 100 i The wafer W to be measured (i=1 to 3) is a 300 mm wafer, and is a wafer on which the pre-processing steps of wafer processing (etching, oxidation / diffusion, film formation, ion implantation, planarization (CMP), etc.) have been completed and before the application of resist. On the wafer W to be measured, a plurality of, for example, I (for example, I=98) partitioned areas called shot areas (hereinafter referred to as shots) are formed in a matrix arrangement by exposure before the pre-processing step. Multiple types of marks, such as search alignment marks (search marks) for search alignment and wafer alignment marks (wafer marks) for fine alignment, are provided on the street lines surrounding each shot or on the street lines within each shot (in the case of multiple chips per shot). These multiple types of marks are formed along with the shots. In this embodiment, two-dimensional marks are used as the search marks and wafer marks.

[0123] Also, the measuring device 100 i The operator inputs information necessary for alignment measurement of the wafer W in advance via an input device (not shown), and the control device 60 i Here, the information necessary for alignment measurement includes various information such as thickness information of the wafer W, flatness information of the wafer holder WH, and design information for the placement of shots and alignment marks on the wafer W.

[0124] The processing corresponding to the flowchart in FIG. 11, which will be described below, is performed in parallel and individually by the three measuring instruments 1001 to 1003.

[0125] 11 starts when, for example, an operator or host computer 2000 issues a command to start measurement. At this time, of the 25 wafers included in one lot, the number of wafers assigned to each measuring device is equal to the number assigned to each measuring device 100. i Chamber 101 i The measuring devices 100 are housed in wafer carriers at predetermined positions within the measuring device 100. i In parallel with the measurement process by the measuring device 100, each wafer in one lot is measured. i For example, under the control of a measurement system control device 5301 that controls the robot 516, the transport member 524, the transport member 526, and the like, for example, 25 wafers contained in one lot in a predetermined FOUP 520 are sequentially taken out one by one by the robot 516, and then transported to the three measurement devices 100 by the transport member 524. i In this case, the process algorithm corresponding to the flowchart in FIG. 11 starts when the measurement system control device 5301 controls each control device 60. i and when a command to start transport is given to the robot 516.

[0126] When the exposure apparatus 200 and the measurement system 5001 are connected, the exposure controller 220 of the exposure apparatus 200 may instruct the measurement system controller 5301 to start measurement without going through the host computer 2000.

[0127] In addition, the measuring device 100 i Like the exposure apparatus 200 and C / D 300, the wafer transfer system 70 is equipped with a barcode reader (not shown). iDuring wafer transport by the measuring device 100 (see FIG. 8), the barcode reader appropriately reads the identification information of each wafer, such as the wafer number and lot number. In the following, for the sake of simplicity, the description of reading the identification information of each wafer using the barcode reader will be omitted. i For example, a barcode reader may be provided in the transport system 521.

[0128] First, in step S102, the count value i of a counter indicating the number of the wafer to be measured is initialized to 1 (i←1).

[0129] In the next step S104, the wafer W is loaded onto the slider 10. This loading of the wafer W is performed by the control device 60. i Under the control of the wafer transport system 70 i and the vertically moving member on the slider 10. Specifically, the wafer transfer system 70 i The wafer W is transferred from the wafer carrier (or transfer position) to above the slider 10 at the loading position, and the vertically movable member is raised by a predetermined amount by the drive device 13, whereby the wafer W is transferred to the vertically movable member. i After the measuring device 100 has retracted from above the slider 10, the vertically moving member is driven downward by the driving device 13, and the wafer W is placed on the wafer holder WH on the slider 10. Then, the vacuum pump 11 is turned on, and the wafer W loaded on the slider 10 is vacuum-sucked by the wafer holder WH. i In parallel with the measurement process by the measuring device 100, each of the plurality of wafers included in one lot is measured. i When the wafers are sequentially carried into the FOUP 520, prior to the loading of the wafers, the plurality of wafers in the FOUP 520 are sequentially taken out one by one by the robot 516, and are transferred from the robot 516 to the transfer member 524, which then transfers the wafers to the measuring device 100. i The wafer is transferred to a predetermined transfer position by the wafer transfer system 70. i will be passed to.

[0130] In the next step S106, the position of the wafer W in the Z-axis direction (Z position) is adjusted. Prior to this adjustment of the Z position, the control device 60 i Based on the relative position information in the Z-axis direction, θy direction, and θx direction between the mark detection system MDS and the surface plate 12 measured by the second position measurement system 50, the internal pressure of the air mounts of the three vibration isolators 14 (the driving force in the Z-axis direction generated by the vibration isolators 14) is controlled, and the surface plate 12 is set so that its upper surface is parallel to the XY plane and the Z position is a predetermined reference position. It is considered that the wafer W has a uniform thickness. Therefore, in step S106, the control device 60 i Based on the thickness information of the wafer W stored in the memory, the control unit 60 adjusts the driving force in the Z-axis direction generated by the three vibration isolation devices 14, for example, the internal pressure (amount of compressed air) of the air mount, to drive the surface plate 12 in the Z-axis direction and adjust the Z position of the surface of the wafer W, so that the surface of the wafer W is set within a range where the focal position of the optical system can be adjusted by the autofocus function of the mark detection system MDS. If the measurement unit 40 is equipped with a focal position detection system, the control unit 60 i The Z position of the wafer surface may be adjusted based on the detection result (output) of the focal position detection system. For example, the mark detection system MDS may be equipped with a focal position detection system that detects the Z-axis position of the wafer W surface via an optical element (objective optical element) at its tip. Furthermore, the Z position of the wafer W surface can be adjusted based on the detection result of the focal position detection system by moving the surface plate 12 using the vibration isolation device 14 and then moving the slider 10 together with the surface plate 12. The slider 10 may be moved using a drive system 20 configured to be able to drive the slider 10 not only in the XY plane but also in the Z-axis, θx, and θy directions. The Z position adjustment of the wafer surface may also include adjusting the tilt of the wafer surface. If using the drive system 20 to adjust the tilt of the wafer surface could potentially result in an error (a type of Abbe error) due to the difference ΔZ in the Z position between the surface on which the grating RG1 is located and the surface of the wafer W, at least one of the measures described above may be implemented.

[0131] In the next step S108, search alignment of the wafer W is performed under predetermined search mark measurement conditions. The search mark measurement conditions may be the same as the first conditions set in step S110, as will be described later, or may be measurement conditions that are more suitable for measuring the search mark, taking into account the difference between the wafer mark and the search mark.

[0132] In the search alignment, for example, at least two search marks located on the periphery of the wafer W and approximately symmetrically with respect to the center of the wafer W are detected using the mark detection system MDS. i controls the driving of the slider 10 by the driving system 20 to position each search mark within the detection area (detection field) of the mark detection system MDS, acquires measurement information by the first position measurement system 30 and measurement information by the second position measurement system 50, and determines position information of each search mark based on the detection signal when the search mark formed on the wafer W is detected using the mark detection system MDS and the measurement information by the first position measurement system 30 (and measurement information by the second position measurement system 50).

[0133] Here, the search mark is measured by irradiating the search mark with broadband light (detection light) from the optical system of the mark detection system MDS, receiving diffracted light of a predetermined order (for example, ±1st order) generated from the search mark with a detector, and processing the photoelectric conversion signal according to predetermined signal processing conditions.

[0134] control device 60 i determines the position coordinates of the two search marks on the reference coordinate system based on the detection results of the mark detection system MDS output from the signal processing device 49 (the relative positional relationship between each search mark and the detection center (index center) of the mark detection system MDS obtained by processing the above photoelectric conversion signal under the above signal processing conditions) and the measurement values ​​of the first position measurement system 30 (and the measurement values ​​of the second position measurement system 50) when each search mark is detected. Here, the reference coordinate system is an orthogonal coordinate system defined by the measurement axis of the first position measurement system 30.

[0135] Thereafter, the residual rotation error of the wafer W is calculated from the position coordinates of the two search marks, and the slider 10 is rotated slightly so that this rotation error becomes approximately zero. This completes the search alignment of the wafer W. Note that, since the wafer W is actually loaded onto the slider 10 in a pre-aligned state, the deviation of the center position of the wafer W is negligibly small, and the residual rotation error is extremely small.

[0136] In the next step S110, the first conditions instructed by the measurement system control device 5301 are set as the measurement conditions (alignment measurement conditions) of the above-mentioned mark, which include at least one of the irradiation conditions for irradiating the mark with detection light, the light receiving conditions for receiving the light generated from the mark, and the signal processing conditions for processing the photoelectric conversion signal obtained by receiving the light generated from the mark.

[0137] In step S110, at least one of switchable irradiation conditions, light receiving conditions, and signal processing conditions suitable for detecting wafer marks is set as a first condition. Here, as an example of the first condition, for example, optimization of the wavelength of illumination light in the mark detection system MDS is assumed. Also, as an example, the wafer mark formed on the wafer W to be processed is a mark formed on the top layer of the pattern layers stacked on the wafer W, and there is no need to limit the wavelength of the observation light (illumination light) to observe this, and it is sufficient to observe it with broadband white light emitted from an illumination light source such as a halogen lamp. Therefore, the control device 60 i Next, the wavelength selection mechanism of the mark detection system MDS is set (controlled) so that a filter that transmits a light beam (white light) with a wavelength of 530 to 800 nm is selected in the wavelength selection mechanism.

[0138] In the next step S112, under the setting of the first condition, alignment measurement is performed for the entire wafer (one point measurement for all shots, in other words, EGA measurement for all shots), that is, one wafer mark is measured for each of the 98 shots. iis used to calculate the position coordinates of the wafer mark on the wafer W in the reference coordinate system, i.e., the position coordinates of the shot, in the same way as measuring the position coordinates of each search mark during the above-mentioned search alignment. However, in this case, detection light of a broadband wavelength determined by the first condition is irradiated onto the wafer mark via the optical system of the mark detection system MDS with the light amount set by default and under conventional illumination conditions (σ value), and diffracted light of a predetermined order (for example, ±1st order) generated from the wafer mark is received by a detector, and the photoelectric conversion signal is processed according to the signal processing conditions (processing algorithm) set by default, thereby obtaining the mark detection results used to calculate the position coordinates of the wafer mark on the wafer W in the reference coordinate system.

[0139] However, in this case, unlike the search alignment, the measurement information of the second position measurement system 50 is always used when calculating the position coordinates of the shot. The reason for this is that, as described above, the control device 60 i Based on the measurement information of the second position measurement system 50, the actuators of the three vibration isolation devices 14 are controlled in real time so that the detection point of the first position measurement system 30 coincides with the detection center of the mark detection system MDS in the XY plane, for example, at the nm level, and so that the surface of the wafer W on the slider 10 coincides with the detection position of the mark detection system MDS. However, when detecting wafer marks, there is no guarantee that the detection point of the first position measurement system 30 coincides with the detection center of the mark detection system MDS in the XY plane, for example, at the nm level. Therefore, it is necessary to calculate the position coordinates of the shot by taking into account the amount of positional deviation between the two as an offset. For example, by using the offset to correct the detection result of the mark detection system MDS or the measurement value of the first position measurement system 30, the calculated position coordinates of the wafer mark on the wafer W in the reference coordinate system can be corrected.

[0140] Here, when performing this one-point measurement for all shots, the control device 60 iBased on the measurement information from the first position measurement system 30 and the measurement information from the second position measurement system 50, the slider 10 (wafer W) is moved in at least one of the X-axis direction and the Y-axis direction via the drive system 20, and the wafer mark is positioned within the detection area of ​​the mark detection system MDS. That is, the slider 10 is moved relative to the mark detection system MDS in the XY plane in a step-and-repeat manner, and one-point measurement of all shots is performed.

[0141] If the measurement unit 40 is equipped with a focal position detection system, the control device 60 i Alternatively, the Z position of the wafer surface may be adjusted based on the detection result (output) of the focal position detection system.

[0142] When the slider 10 is moved in the XY plane during alignment measurement for all wafers (one point measurement for all shots) in step S112, an unbalanced load acts on the surface plate 12 in accordance with the movement. i However, the control device 60 individually controls the three vibration isolation devices 14 in a feedforward manner so as to cancel out the influence of the unbalanced load according to the X and Y coordinate positions of the slider contained in the measurement information of the first position measurement system 30, and individually controls the driving force in the Z-axis direction generated by each vibration isolation device 14. i Alternatively, the offset load acting on the surface plate 12 may be predicted based on information about the known movement path of the slider 10 without using the measurement information of the first position measurement system 30, and the three vibration isolation devices 14 may be individually feedforward controlled to cancel out the influence of the offset load. In this embodiment, information about the unevenness of the wafer holding surface of the wafer holder WH (the surface defined by the upper end surfaces of the many pins of the pin chuck) (hereinafter referred to as holder flatness information) is obtained in advance by experiment or the like. Therefore, when moving the slider 10 for alignment measurement (for example, one-point measurement for all shots), the control device 60 iBased on the holder flatness information, the three vibration isolators 14 are feedforward controlled so that the area including the wafer mark to be measured on the surface of the wafer W is quickly positioned within the focal depth range of the optical system of the mark detection system MDS, thereby fine-tuning the Z position of the surface plate 12. Note that it is not necessary to perform either or both of the feedforward control for offsetting the influence of the unbalanced load acting on the surface plate 12 described above and the feedforward control based on the holder flatness information.

[0143] If the magnification of mark detection system MDS is adjustable, it may be set to a low magnification during search alignment and to a high magnification during alignment measurement. Also, if the deviation of the center position of wafer W loaded on slider 10 and the residual rotation error are small enough to be ignored, step S108 may be omitted.

[0144] In the all-shot one-point measurement in step S112, actual measurement values ​​of position coordinates of a sample shot area (sample shot) in a reference coordinate system are detected, which are used in the EGA calculation described later. The sample shots refer to a specific plurality (at least three) of shots that are predetermined among all shots on the wafer W as being used in the EGA calculation described later. Note that in the all-shot one-point measurement, all shots on the wafer W become sample shots. After step S112, the process proceeds to step S114.

[0145] In step S114, EGA calculation is performed using the position information of the wafer marks measured in step S112. The EGA calculation means a statistical calculation that, after the above-mentioned wafer mark measurement (EGA measurement), uses statistical calculations such as the least squares method based on data on the difference between the design values ​​and the actual measured values ​​of the position coordinates of the sample shots to find the coefficients of a model formula that expresses the relationship between the position coordinates of the shots and the correction amounts for the position coordinates of the shots.

[0146] In this embodiment, as an example, the following model formula is used to calculate the correction amount from the design value of the shot position coordinates.

[0147]

number

[0148] Here, dx and dy are the correction amounts in the X-axis and Y-axis directions from the design values ​​of the shot position coordinates, and X and Y are the design position coordinates of the shot in a wafer coordinate system with the center of the wafer W as the origin. That is, the above formula (1) is a polynomial related to the design position coordinates X and Y of each shot in a wafer coordinate system with the center of the wafer as the origin, and is a model formula expressing the relationship between the position coordinates X and Y and the correction amounts (alignment correction components) dx and dy of the position coordinates of the shot. In this embodiment, since the rotation between the reference coordinate system and the wafer coordinate system is canceled by the above-mentioned search alignment, the following description will not particularly distinguish between the reference coordinate system and the wafer coordinate system, and will instead treat them as the reference coordinate system.

[0149] Using model formula (1), the correction amount for the position coordinates of a shot on wafer W can be calculated from the position coordinates X and Y of that shot. However, in order to calculate this correction amount, it is necessary to calculate the coefficients a0, a1, ..., b0, b1, .... After EGA measurement, the coefficients a0, a1, ..., b0, b1, ... of formula (1) are calculated using statistical calculations such as the least squares method based on the data on the difference between the design values ​​and the actual measured values ​​of the position coordinates of the sample shot.

[0150] After determining the coefficients a0, a1, ..., b0, b1, ... of model formula (1), the design position coordinates X, Y of each shot (divided area) in the wafer coordinate system are substituted into model formula (1) after the coefficients have been determined, and the correction amounts dx, dy of the position coordinates of each shot are found, thereby making it possible to find the true arrangement of multiple shots (divided areas) on wafer W (including not only linear components but also nonlinear components as deformation components).

[0151] However, in the case of a wafer W that has already been exposed, the waveforms of the detection signals obtained as measurement results are not necessarily good for all wafer marks due to the effects of the processes up to that point. If the positions of wafer marks with such poor measurement results (waveforms of the detection signals) are included in the above EGA calculation, the position errors of the wafer marks with poor measurement results (waveforms of the detection signals) will adversely affect the calculation results of the coefficients a0, a1, ..., b0, b1, ...

[0152] Therefore, in this embodiment, the signal processing device 49 transmits only the measurement results of wafer marks with good measurement results to the control device 60. i and the control device 60 i The control device 60 performs the above-mentioned EGA calculation using the positions of all wafer marks for which it has received measurement results. There is no particular restriction on the degree of the polynomial in the above equation (1). i stores the results of the EGA calculation in an internal or external storage device as an alignment history data file in association with wafer identification information (e.g., wafer number, lot number). Note that the alignment history data file may also include information other than the results of the EGA calculation (e.g., information on the marks used in the EGA calculation).

[0153] When the EGA calculation in step S114 is completed, the process proceeds to step S116, where the wafer W is unloaded from the slider 10. This unloading is performed by the control device 60. i Under the control of the wafer transfer system 70, the wafer is transferred in the reverse order of the loading procedure in step S104. i and a vertically moving member on the slider 10. i In parallel with the measurement process by the measuring device 100 i Each of a predetermined number of wafers in the same lot that is to be measured by the measuring device 100 i The measuring device 100 i When the wafers W are sequentially transferred from the wafer transfer system 70 after measurement, iThe wafer is then transferred to the transfer member 526 by the robot 516, and is then returned to the predetermined FOPU 520 by the robot 516 after being transferred to the unload side wafer transfer position by the transfer member 526.

[0154] In the next step S118, the count value i of the counter is incremented by 1 (i←i+1), and then the process proceeds to step S120, where the count value i is compared with the number of measuring devices 100 in the same lot. i It is determined whether or not the number M of wafers to be measured is greater than the number M of wafers to be measured. The number M is 9 for the measuring tool 1001, and 8 for the measuring tools 1002 and 1003.

[0155] If the determination in step S120 is negative, the measurement device 100 i If the process has not been completed for all wafers that the system is responsible for measuring, the process returns to step S104, and the processes (including the determination) from step S104 to step S120 are repeated until the determination in step S120 becomes positive.

[0156] If the determination in step S120 is affirmative, the measurement device 100 i When the process has been completed for all wafers that the system is responsible for measuring, the series of processes in this routine is terminated.

[0157] As can be seen from the above description, the measurement device 100 iAccording to this document, during alignment measurement, the position information (coordinate position information) of at least one wafer mark is measured for each of I (e.g., 98) shots on the wafer W. The measured position information (excluding position information of wafer marks with poor measurement results) is then used to calculate the coefficients a0, a1, ..., b0, b1, ... in the above equation (1) through statistical calculations such as the least squares method. This makes it possible to accurately calculate not only linear but also nonlinear components of the wafer grid deformation components. Here, the wafer grid refers to a lattice formed by connecting the centers of shots on the wafer W arranged according to a shot map (data related to the arrangement of shots formed on the wafer W). Calculating the correction amounts (alignment correction components) dx and dy of the shot position coordinates for multiple shots is equivalent to calculating the deformation components of the wafer grid. In this specification, the wafer grid is abbreviated as "grid" or referred to as "arrangement of shot areas (or shots)."

[0158] In the measurement system 5001, the three measurement tools 1001 to 1003 can perform the measurement process in parallel according to the flowchart described above. That is, the measurement tools 1001 to 1003 can measure the position of at least one wafer mark for all shots on each wafer for a predetermined number of wafers to be measured, each stored in a wafer carrier, that is, a total of one lot of wafers, in a measurement process time that is essentially one-third of the number of wafers in one lot, and can accurately determine not only linear components but also non-linear components of the deformation components of the wafer grid. In parallel with the measurement process, each measurement tool 100 i Wafer loading and each measuring device 100 iEven when measured wafers are removed from the FOUP 520, wafers in one lot loaded into one load port 514 can be processed in parallel, making it possible to measure the position of at least one wafer mark for all shots on each wafer in a processing time that is essentially one-third of the number of wafers in one lot, and accurately determining not only linear components but also non-linear components of the deformation components of the wafer grid. Note that the three measuring tools 1001-1003 may be adjusted using, for example, a reference wafer so that when one wafer in one lot is measured and processed by each of the three measuring tools 1001-1003 under the same conditions, substantially the same measurement results are obtained.

[0159] The obtained information on the wafer grid of each wafer, for example, data on the deformation components of the wafer grid of each wafer (data of the model formula (1) after determining the coefficients a0, a1, . . . , b0, b1, . . . ) is stored in the measuring device 100. i Control device 60 i and transmits the data as part of the alignment history data file for each wafer to the measurement system control device 5301. The measurement system control device 5301 stores the alignment history data file including the received information on the wafer grid for each wafer, for example, the received data on the deformation components of the wafer grid for each wafer (data of model formula (1) after determining coefficients a0, a1, ..., b0, b1, ...) in an internal storage device, for example, for each wafer.

[0160] As described above, the measuring tools 1001 to 1003 perform measurement processing of 25 wafers included in the same lot in parallel, dividing the processing load into 9 wafers, 8 wafers, and 8 wafers, so the measurement processing by the measuring tools 1001 to 1003 is completed almost simultaneously. Therefore, the measurement processing is completed in about one-third of the time compared to when 25 wafers from the same lot are processed sequentially by one measuring tool. In the above case, it is desirable to start processing by the measuring tool 1001 first, as it is responsible for one more wafer.

[0161] When measurement of all wafers included in one lot is completed, the measurement system control device 5301 transmits wafer grid information (alignment history data file) for each of the wafers included in that lot to the host computer 2000. Needless to say, the wafer grid information (alignment history data file) transmitted from the measurement system 5001 also includes data on the nonlinear components of the wafer grid.

[0162] In addition, the measuring device 100 i Control device 60 i is connected to the host computer 2000 via the LAN 1500, and the wafer grid information (alignment history data file) is transmitted to the control device 60 without going through the measurement system control device 5301. i The data may be transmitted to the host computer 2000.

[0163] In this embodiment, the measurement system 5001 transmits (outputs) information about the wafer grid. However, the information (data) transmitted from the measurement system 5001 is not limited to this. For example, the measurement device 100 i The coordinate position information of the plurality of wafer marks measured in the above may be transmitted (output) as at least a part of the alignment history data of each wafer.

[0164] First, among the 25 wafers included in one lot, the number of wafers assigned to each measuring device is 100. i Chamber 101 i If the wafers are stored in a wafer carrier in the FOUP 520, the number of wafers handled by each measuring device will be returned to the respective wafer carriers when the measurement is completed. Therefore, the measurement system control device 5301 must use the transfer system 521 to return the wafers in each wafer carrier to the FOUP 520. On the other hand, i In parallel with the measurement process by the measuring device 100, each wafer in one lot is measured. i When the wafers are sequentially carried into the wafer transfer system 70, the transfer member 526i (i = 1 to 3) and transports the wafer that has been measured to the unload side wafer transfer position mentioned above. Robot 516 then transports (returns) the measured wafer that has been transported to the unload side wafer transfer position into FOUP 520.

[0165] Next, the flow of operations when a large number of wafers are processed consecutively by a lithography system including exposure apparatus 200 and C / D 300 will be described.

[0166] First, the intra-C / D transfer system (e.g., a scalar robot) removes the first wafer (W1) from a wafer carrier arranged in the chamber of C / D 300 and transfers it into the coating unit. This causes the coating unit to start applying resist. Once the resist application is complete, the intra-C / D transfer system removes wafer W1 from the coating unit and transfers it into the bake unit. This causes the bake unit to start the heating process (PB) of wafer W1. Then, once the PB of the wafer is complete, the intra-C / D transfer system removes wafer W1 from the bake unit and transfers it into temperature adjustment unit 330. This causes the cool plate inside temperature adjustment unit 330 to start cooling wafer W1. This cooling is performed to a temperature that has no effect inside exposure apparatus 200, typically the target temperature of the air conditioning system of exposure apparatus 200, which is set in the range of 20 to 25°C. Normally, when the wafer is loaded into the temperature control unit 330, the temperature is within ±0.3°C of the target temperature, but the temperature control unit 330 controls the temperature to within ±10 mK of the target temperature.

[0167] Then, when cooling (temperature control) is completed within the temperature control section 330, the wafer W1 is placed by the C / D internal transport system on the load side substrate placement section of the substrate transfer section provided between the C / D 300 and the exposure apparatus 200.

[0168] Within C / D 300, the same series of wafer processes as described above, including resist coating, PB, cooling, and the wafer transport operations associated with these processes, are repeated in sequence, and wafers are sequentially placed on the load-side substrate placement unit. In practice, by providing two or more coating units and two or more intra-C / D transport systems within the chamber of C / D 300, parallel processing of multiple wafers is possible, thereby shortening the time required for pre-exposure processing.

[0169] The wafer W1 placed on the aforementioned load-side substrate placement section is transferred by the wafer transfer system 270 to a predetermined waiting position inside the exposure apparatus 200. However, the first wafer W1 does not wait at the waiting position, but is immediately loaded onto the wafer stage WST by the exposure control device 220. This wafer loading is performed by the exposure control device 220 in accordance with the aforementioned measurement device 100. i This is performed using a vertical movement member (not shown) on wafer stage WST and wafer transport system 270 in the same manner as that performed in . After loading, the wafer on wafer stage WST is subjected to search alignment similar to that described above using alignment detection system AS, and EGA wafer alignment using, for example, approximately 3 to 16 alignment shots. During this EGA wafer alignment, an alignment history data file for the wafer (target wafer) that is the target of wafer alignment and exposure in exposure apparatus 200 is provided to exposure controller 220 of exposure apparatus 200 from host computer 2000, along with identification information for the target wafer (e.g., wafer number, lot number, etc.). The alignment history data that exposure apparatus 200 acquires from host computer 2000 includes information on the wafer grid of each wafer measured by measurement system 5001, and exposure controller 220 performs wafer alignment as described below after performing predetermined preparatory work. Incidentally, the exposure control device 220 and the measurement system control device 5301 may exchange alignment history data and the like without going through the host computer 2000 .

[0170] Before proceeding to a specific description of wafer alignment, the reason why EGA type wafer alignment is performed in exposure apparatus 200, in which approximately 3 to 16 shots are used as alignment shots, will be explained.

[0171] Measuring Device 100 i The correction amounts of the shot position coordinates of the wafer W (coefficients a0, a1, ..., b0, b1, ... in the above formula (1)) obtained by the above are used to align the wafer with respect to the exposure position when exposing the wafer W by the exposure apparatus 200. i The wafer W whose position coordinate correction amount has been measured is then measured by the measuring device 100 as described above. i After being unloaded from slider 10, wafer W is stored in FOUP 520, and FOUP 520 is carried into C / D 300 by an OHT or other transport system. Then, wafer W is coated with resist by C / D 300, and then loaded onto wafer stage WST of exposure apparatus 200 for exposure. In this case, even if the same type of wafer holder is used for wafer holder WH on slider 10 and the wafer holder on wafer stage WST of exposure apparatus 200, the holding state of wafer W will differ due to individual differences between wafer holders. For this reason, it is necessary to take the trouble to measure measurement apparatus 100. i Even if the correction amount for the shot position coordinates of the wafer W (coefficients a0, a1, ..., b0, b1, ... in the above formula (1)) is found, it is not possible to use all of the coefficients a0, a1, ..., b0, b1, ... as they are. However, it is thought that the difference in the holding state of the wafer W for each wafer holder affects only the low-order components (linear components) of the correction amount for the shot position coordinates of the first order or lower, and that the high-order components of the second order or higher are hardly affected. The reason for this is that the high-order components of the second order or higher are thought to be components that arise mainly from deformation of the wafer W due to the process, and can be thought of as components unrelated to the holding state of the wafer by the wafer holder.

[0172] Based on this idea, the measurement device 100 iTherefore, the high-order component coefficients a3, a4, ..., a9, ... and b3, b4, ..., b9, ... that have been calculated over a long period of time for wafer W can also be used as the high-order component coefficients of the correction amount for the position coordinates of wafer W in exposure apparatus 200. Therefore, on wafer stage WST of exposure apparatus 200, it is sufficient to perform simple EGA measurement (for example, measurement of approximately 3 to 16 wafer marks) to calculate the linear components of the correction amount for the position coordinates of wafer W.

[0173] In the exposure apparatus 200, the measurement apparatus 100 included in the alignment history data i From the wafer marks whose position information has been measured (the position information of the marks has been used to calculate the correction amount) by the above method, a number of wafer marks corresponding to the number of alignment shots are selected and set as detection targets. The wafer marks to be detected are detected using alignment detection system AS, and based on the detection results and the position of wafer stage WST at the time of detection (measurement information by interferometer system 218), position information of each wafer mark to be detected is obtained. Using this position information, an EGA calculation is performed to determine the coefficients of the following equation (2).

[0174]

number

[0175] The exposure controller 220 then replaces the coefficients (c0, c1, c2, d0, d1, d2) found here with the coefficients (a0, a1, a2, b0, b1, b2) included in the data on the deformation components of the wafer grid of the target wafer, and calculates correction amounts (alignment correction components) dx and dy for the position coordinates of each shot using a polynomial relating to the design position coordinates X and Y of each shot in a wafer coordinate system with the center of the wafer as the origin, expressed by the following equation (3) including the replaced coefficients. Based on this correction amount, the exposure controller 220 determines a target position (hereinafter referred to as a positioning target position for convenience) for alignment with the exposure position (projection position of the reticle pattern) during exposure of each shot in order to correct the wafer grid. Note that in this embodiment, exposure is performed using a scanning exposure method rather than a stationary exposure method, but for convenience, the term positioning target position is used.

[0176]

number

[0177] In exposure apparatus 200, search alignment also cancels the rotation between the reference coordinate system (stage coordinate system) that defines the movement of wafer stage WST and the wafer coordinate system, so there is no need to particularly distinguish between the reference coordinate system and the wafer coordinate system.

[0178] The exposure controller 220 then controls the position of the wafer stage WST in accordance with the target position, and performs exposure for each shot on the wafer W1 using the step-and-scan method.

[0179] Then, before exposure of the wafer (in this case, wafer W1) on wafer stage WST is completed, the second wafer W2 is placed on the load-side substrate placement section of the substrate transfer section by the C / D internal transport system, and is transported by wafer transport system 270 to a predetermined waiting position inside exposure apparatus 200, where it waits.

[0180] When the exposure of wafer W1 is completed, wafer W1 is exchanged with wafer W2 on the wafer stage, and the same wafer alignment and exposure as described above are performed on the exchanged wafer W2. If the transfer of wafer W2 to the standby position is not completed before the exposure of the wafer on the wafer stage (wafer W1 in this case) is completed, the wafer stage will wait near the standby position while holding the exposed wafer.

[0181] In parallel with the wafer alignment for the exchanged wafer W2, the exposed wafer W1 is transferred by the wafer transfer system 270 to the unload-side substrate placement section of the substrate transfer section.

[0182] As described above, the exposed wafer placed on the unload-side substrate placement section of the substrate transfer section by the wafer transfer system 270 is carried into the bake section by the C / D transfer system, where it is subjected to PEB by the baking device in the bake section. The bake section can accommodate multiple wafers at the same time.

[0183] On the other hand, the wafer for which PEB has been completed is taken out of the bake section by the C / D transport system and carried into the development section, where development is started by the developing device in the development section.

[0184] When the development of the wafer is completed, the wafer is removed from the development section by the C / D transfer system and transferred to a predetermined storage stage in the FOUP 520 used for transfer or a different wafer carrier. After that, in the C / D 300, the PEB, development, and wafer transfer are repeated for the second and subsequent exposed wafers in the same procedure as for wafer W1.

[0185] In the above description, two-dimensional marks are used as wafer marks. However, one-dimensional marks, such as X marks consisting of a line-and-space pattern with a periodic direction in the X-axis direction and Y marks consisting of a line-and-space pattern with a periodic direction in the Y-axis direction, may also be used as wafer marks. In this case, the measurement conditions for measuring the X marks and Y marks using the mark detection system MDS may differ. This situation can occur for various reasons. For example, as shown in U.S. Pat. No. 5,532,091, a situation will be considered where alignment across multiple layers (multilayers) formed on a wafer is required to overlay and expose the next layer. For example, alignment in the Y-axis direction is performed with respect to the immediately preceding layer (as a reference), and alignment in the X-axis direction is performed with respect to the layer immediately preceding the immediately preceding layer (as a reference). More specifically, alignment in the Y-axis direction is performed with respect to a pattern (mark) formed on the top layer among layers of patterns already formed on the wafer W, and alignment in the X-axis direction is performed with respect to a pattern (mark) formed on a layer below the top layer. Therefore, when observing the X-mark during alignment measurement, the X-mark formed on the layer below the top layer is observed from the top surface of the wafer W through the top layer on which the Y-mark is formed. Therefore, the alignment measurement conditions (illumination conditions, optical conditions, signal processing algorithm, etc.) for properly measuring the X-mark are different from the alignment measurement conditions for properly measuring the Y-mark.

[0186] Next, we will explain a measurement method for measuring the position information (coordinate position information) of the X mark and Y mark for each of I (e.g., 98) shots on the measurement wafer using two measurement devices of measurement system 5001. Figure 12 shows an outline of the processing flow in the measurement method in this case.

[0187] First, in step S202, the wafer W 11A FOUP containing a plurality of wafers from a certain lot, including the wafers (substrates to be measured), is placed on the load port 514 of the measurement system 5001 using the OHT or the like. 11 A plurality of wafers in a certain lot, including the wafers 100, are sequentially taken out of the FOUP using a robot 516 or the like, and are then transported to the measuring device 100 using a transport system 521 or the like. i (i=1 to 3).

[0188] In the following, one of the wafers housed in the FOUP will be referred to as a wafer W 11 The same process is performed on all of the wafers housed in the FOUP. 11 The following describes a case where the X mark is measured by the measuring device 1001 and then the Y mark is measured by the measuring device 1002. Of course, the Y mark may be measured by the measuring device 1001 and then the X mark may be measured by the measuring device 1002.

[0189] Wafer W 11 After being transported to the measuring device 1001 as described above, in step S204, under the control of the control device 601, the wafer is loaded onto the slider 10 of the measuring device 1001 by the wafer transport system 701 and the vertically moving member on the slider 10 in the same procedure as in step S104 described above.

[0190] Next, in step S206, the wafer W is measured by the measuring device 1001. 11 The measurement conditions for the X marks are set to the first predetermined conditions. Hereinafter, the first predetermined conditions will also be referred to as the second conditions to distinguish them from the first conditions. The second conditions are set to the first predetermined conditions. 11 These are measurement conditions suitable for detecting the X mark formed on the wafer W. Here, as in the above, the alignment measurement conditions (an example of the second condition) are set to optimize the wavelength of the illumination light in the mark detection system MDS. 11The X mark formed on the mark detection system MDS is a mark formed on a lower layer (for example, the layer one layer below) of the uppermost layer, and in order to properly observe this mark, it is preferable to use observation light (illumination light) that has high transmittance with respect to the material that constitutes the uppermost layer. Here, it is assumed that such observation light is light in the red region, for example. Therefore, the control device 601 sets (controls) the wavelength selection mechanism of the mark detection system MDS so that a filter that transmits a light beam with a wavelength of 710 to 800 nm (red light) is selected.

[0191] Next, in step S208, the wafer W is 11 The absolute position coordinates of the I X marks in the XY plane are calculated as follows: That is, the control device 601 measures the position information of the slider 10 using the first position measurement system 30 (and the second position measurement system 50), while detecting the position of the wafer W using the mark detection system MDS. 11 The I X marks on the wafer W are detected, and the wafer W is calculated based on the detection results of the I X marks and the absolute position coordinates (X, Y) of the slider 10 at the time of detection of each X mark. 11 The absolute position coordinates of each of the I X marks on the wafer W are calculated in the XY plane. However, in this case, detection light in the red wavelength range determined by the second condition is irradiated onto the wafer mark through the optical system of the mark detection system MDS under conventional illumination conditions (σ value) with the light amount set by default, and diffracted light of a predetermined order (for example, ±1st order) generated from the wafer mark is received by a detector, and the photoelectric conversion signal is processed according to the signal processing conditions (processing algorithm) set by default, thereby obtaining the absolute position coordinates of each of the I X marks on the wafer W. 11 The detection results of the marks are obtained, which are used to calculate the position coordinates of the wafer marks on the reference coordinate system. At this time, the control device 601 calculates the absolute position coordinates of each of the I X marks in the XY plane using, as offsets, the Abbe errors in the X-axis and Y-axis directions of the first position measurement system 30 and the measurement values ​​in the X-axis and Y-axis directions of the second position measurement system 50, which are obtained based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30.

[0192] Next, in step S210, the wafer W 11 is unloaded from the slider 10 of the measuring device 1001 and loaded onto the slider 10 of the measuring device 1002 without being carried out to the outside of the measuring system 5001. 11 Under the control of the control device 601, the wafer W is unloaded from the slider 10 of the measuring device 1001 by the wafer transfer system 701 and the vertically moving member on the slider 10 in the reverse order of the loading procedure in step S204 (and step 104), and then transferred to the transfer member 524 (or 526) by the wafer transfer system 701, and then transferred to the transfer position with the measuring device 1002 by the transfer member 524 (or 526). Thereafter, under the control of the control device 602, the wafer W is transferred to the slider 10 of the measuring device 1002 by the wafer transfer system 702 and the vertically moving member on the slider 10 in the same order as in the above-mentioned step S104. 11 is loaded onto the slider 10 of the measurement device 1002.

[0193] Next, in step S212, the wafer W is measured by the measuring device 1002. 11 The measurement conditions for the Y marks are set to the second predetermined conditions. Hereinafter, the second predetermined conditions are also referred to as the third conditions. The third conditions are set to the second predetermined conditions. 11 These are measurement conditions suitable for detecting the Y mark formed on the wafer W. Here, as in the case described above, the alignment measurement condition (an example of the third condition) is to optimize the wavelength of the illumination light in the mark detection system MDS. 11 The Y mark formed on the mark detection system MDS is a mark formed on the outermost layer, and there is no need to limit the wavelength of the observation light (illumination light) to be used for observing the mark, and it can be observed using broadband white light emitted from an illumination light source such as a halogen lamp. Therefore, the control device 605 sets (controls) the wavelength selection mechanism of the mark detection system MDS so that a filter that transmits a light beam (white light) with a wavelength of 530 to 800 nm is selected in the wavelength selection mechanism.

[0194] Next, in step S214, the wafer W is heated under the third condition set by the control device 602. 11The absolute position coordinates of the I Y marks in the XY plane are obtained in the same manner as the absolute position coordinates of the X marks in the XY plane in step S208. At this time, the control device 602 obtains the absolute position coordinates of the I Y marks in the XY plane using, as offsets, the Abbe errors in the X-axis and Y-axis directions of the first position measurement system 30 and the measurement values ​​in the X-axis and Y-axis directions of the second position measurement system 50, which are obtained based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30.

[0195] As described above, the three measuring tools 1001-1003 are adjusted so that when, for example, one wafer in one lot is measured by each of the three measuring tools 1001-1003 under the same conditions, substantially the same measurement results are obtained. Therefore, in the next step S216, the measurement system control device 5301 (or control device 602) determines the coefficients a0, a1, ..., b0, b1, ... of the above equation (1) by statistical calculations (EGA calculations) such as the least squares method, similar to the above step S114, based on the absolute position coordinates of the X mark determined in step S208 and the absolute position coordinates of the Y mark determined in step S214. Thereafter, similar to the flowchart of FIG. 11, when the measurement process for the wafers in the lot to be measured is completed, the series of processes ends.

[0196] Thus, in this example, measuring device 1001 measures the X marks on all wafers in the lot under the second condition, and measuring device 1002 measures the Y marks on all wafers in the lot under the third condition. Therefore, measuring device 1001 and measuring device 1002 can accurately measure the marks to be measured without changing their respective measurement conditions until measurements on all wafers in the lot to be measured are completed.

[0197] When measurement of all wafers included in one lot is completed, the measurement system control device 5301 transmits wafer grid information (alignment history data file) for each of the wafers included in that lot to the host computer 2000. Needless to say, the wafer grid information (alignment history data file) transmitted from the measurement system 5001 also includes data on the nonlinear components of the wafer grid.

[0198] In addition, the measuring device 100 i Control device 60 i is connected to the host computer 2000 via the LAN 1500, and the wafer grid information (alignment history data file) is transmitted to the control device 60 without going through the measurement system control device 5301. i The data may be transmitted to the host computer 2000.

[0199] In this embodiment, the measurement system 5001 transmits (outputs) information about the wafer grid. However, the information (data) transmitted from the measurement system 5001 is not limited to this. For example, the measurement device 100 i The coordinate position information of the wafer mark (X mark) measured in the step 1 and the coordinate position information of the wafer mark (Y mark) measured in the step 2 may be transmitted (output) as at least a part of the alignment history data of each wafer.

[0200] In measurement system 5001, it is also possible to perform at least part of the acquisition of the absolute position coordinates of the X mark for a wafer included in the measurement target lot by measurement device 1001 and the acquisition of the absolute position coordinates of the Y mark for another wafer included in the measurement target lot by measurement device 1002 in parallel. In such a case, it is possible to reduce the measurement time for all wafers included in the measurement target lot.

[0201] In the above description, the wafer to be measured has X and Y marks formed on different layers, but the X and Y marks may be formed on the same layer. In this case, if the measurement conditions suitable for detecting the X and Y marks are different from each other, for example, the measurement device 1001 may acquire the absolute position coordinates of the X and Y marks, and the measurement device 1002 may acquire the absolute position coordinates of the Y marks.

[0202] As mentioned above, the measurement device 100 i is equipped with the first position measurement system 30, and by determining the origin of an orthogonal coordinate system (reference coordinate system) defined by the measurement axis of the first position measurement system 30, it is possible to manage the absolute position of the slider 10, and in turn the absolute position of a wafer mark, for example, an overlay measurement mark (registration mark) on the wafer W held on the slider 10, which is determined from the position information of the slider 10 and the detection result of the mark detection system MDS, on the reference coordinate system. i It should be noted that in this specification, the term "absolute position" refers to a coordinate position on a reference coordinate system.

[0203] Therefore, the measurement device 100 of the measurement system 5001 i At least one of the measuring devices 100 (i=1 to 3) can function as an overlay measuring device. i The measurement is performed on a wafer after the pre-processing step of the wafer processing has been completed and before the resist is applied. Therefore, each measuring device 100 of the measurement system 5001 i In parallel with measurement of wafers in a certain lot by the measurement system 5001, overlay measurement and the like can be performed on wafers in another lot by the measurement system 5002.

[0204] Next, a description will be given of an overlay measurement method using the two measurement devices of the other measurement system 5002. Figures 13 and 14 show an outline of the processing flow in the overlay measurement method in this case.

[0205] First, in step S302, wafers included in a certain lot (wafers W 11 The wafer W (hereinafter referred to as "wafer W") is carried into the C / D 300, and in the coating section of the C / D 300, the wafer W is subjected to exposure of the first layer (lower layer) by the exposure apparatus 200 or an exposure apparatus different from the exposure apparatus 200, such as a scanner or a stepper. 11 The resist is applied to the wafer W before the resist is applied. 11 In the upper layer, a plurality of, for example, I (I is, for example, 98) shots are formed by exposure of the lower layer, along with wafer marks whose design positional relationships with the shots are known and first marks for measuring overlay deviations (more precisely, resist images of the first marks (also referred to as first mark images as appropriate)) corresponding to each shot. In this case, the design positional relationships of each of the I first mark images are also known.

[0206] Next, in step S304, the wafer W coated with the resist is 11 is subjected to the same predetermined processing steps as the wafer W1 described above, and is loaded onto the wafer stage WST of the exposure apparatus 200. 11 After the wafer is subjected to a heat treatment (PB) in the bake section and temperature control in the temperature control section 330, it is loaded onto the wafer stage WST.

[0207] Next, in step S306, the exposure controller 220 of the exposure apparatus 200 adjusts the wafer W on the wafer stage WST. 11 For this, the same search alignment as described above is performed using alignment detection system AS, and EGA type wafer alignment is performed using, for example, about 3 to 16 shots as alignment shots.

[0208] As described above, prior to step S302, the measurement device 100 of the measurement system 5001 i(i=1~3) wafer W 11 The wafer grid information is determined and provided to exposure controller 220 of exposure tool 200.

[0209] Next, in step S308, the exposure control device 220 calculates the correction amounts (alignment correction components) dx and dy of the position coordinates of each shot expressed by the above-mentioned equation (3) based on the results of the wafer alignment, and based on these correction amounts, determines the positioning target positions for exposure of each shot in order to correct the wafer grid.

[0210] Prior to step 302, the measurement device 100 of the measurement system 5001 i Wafer W 11 Instead of obtaining information about the wafer grid, the target position for exposure of each shot may be determined based only on the results of EGA-type wafer alignment using alignment detection system AS, with approximately 3 to 16 shots as alignment shots.

[0211] Next, in step S310, the exposure apparatus 200 controls the position of the wafer stage WST in accordance with the target position. 11 For each shot on the wafer W, the second layer (the upper layer with the first layer as the lower layer) is exposed using the step-and-scan method. 11 A reticle (for convenience, referred to as reticle R) on which a second mark is formed corresponding to the first mark image above is shown. 11 Therefore, by exposing this second layer, the wafer W 11 Reticle R for the above I shots 11 The pattern areas are transferred in an overlapping manner, and a transferred image of I second marks arranged in a positional relationship corresponding to the positional relationship of the I first marks is formed.

[0212] Next, in step S312, the wafer W after the exposure of the second layer is 11The wafer W is subjected to the same processing steps as the exposed wafer W1 described above, and is then carried into the developing section of the C / D 300. 11 The wafer W is transported to the unload-side substrate placement section of the substrate transfer section by the wafer transport system 270, and is then transported from the unload-side substrate placement section into the bake section of the C / D 300 by the intra-C / D transport system, where it is subjected to PEB by the baking device in the bake section. 11 The wafer is taken out of the baking section by the C / D transport system and carried into the developing section.

[0213] Next, in step S314, the wafer W on which the transferred images of the plurality of second marks have been formed is developed by the developing device in the developing section. 11 By this development, the wafer W 11 On the substrate, along with I shots, I sets of first mark images and corresponding second mark images are formed in a predetermined positional relationship, and this becomes the substrate to be measured during overlay measurement. That is, in this manner, the substrate to be measured during overlay measurement (overlay measurement target substrate) is fabricated. Here, as the set of first mark images and corresponding second mark images, for example, a resist image of a box-in-box mark consisting of an outer box mark and an inner box mark placed inside it can be used.

[0214] Next, in step S316, the developed wafer W 11 A FOUP containing a plurality of wafers of a certain lot, including the substrate (substrate to be subjected to overlay measurement), is taken out from C / D 300 and placed on the load port 514 of the measurement system 5002 using the above-mentioned OHT or the like. 11 A plurality of wafers in a certain lot, including the wafers W, are transferred to the measurement system 5002 before undergoing a process (etching process or film formation process after etching process (including at least one of sputtering process, CVD process, and thermal oxidation process)) that is performed after the development process. 11A plurality of wafers in a certain lot, including the wafers 100, are sequentially taken out of the FOUP using a robot 516 or the like, and are then transported to the measuring device 100 using a transport system 521 or the like. i (i=4 to 6).

[0215] In the following, one of the wafers housed in the FOUP will be referred to as a wafer W 11 Although the following description will be given for the wafer W, the same processing is performed on all or some of the wafers housed in the FOUP. 11 Regarding (the substrate to be measured during overlay measurement), a case where the measurement of the first mark image is performed by the measuring device 1004 and the measurement of the second mark image is performed by the measuring device 1005 will be described.

[0216] Wafer W 11 After being transported to the measuring device 1004 as described above, in step S318, under the control of the control device 604, the wafer is loaded onto the slider 10 of the measuring device 1004 by the wafer transport system 704 and the vertically moving member on the slider 10 in the same procedure as in step S104 described above.

[0217] Next, in step S320, the wafer W is measured by the measuring device 1004. 11 The measurement conditions for the first mark image are set to a first predetermined condition. Hereinafter, this first predetermined condition will also be referred to as a second condition to distinguish it from the first condition described above. The second condition is set to a condition where the wafer W is exposed to the first layer. 11 These are measurement conditions suitable for detecting the first mark image formed on the wafer W. Here, as in the above, the alignment measurement conditions (an example of the second conditions) are set to optimize the wavelength of the illumination light in the mark detection system MDS. 11The first mark image formed in is a mark formed in the first layer (a lower layer (e.g., the layer one layer below) with the second layer (the outermost layer) as the upper layer), and in order to observe this properly, it is preferable to use observation light (illumination light) that has high transmittance for the material that makes up the outermost layer. Here, it is assumed that such observation light is light in the red region, for example. Therefore, the control device 604 sets (controls) the wavelength selection mechanism of the mark detection system MDS so that a filter that transmits a light beam with a wavelength of 710 to 800 nm (red light) is selected in the wavelength selection mechanism.

[0218] Next, in step S322, the wafer W is 11 The absolute position coordinates of the I first mark images in the XY plane are calculated as follows: That is, the control device 604 measures the position information of the slider 10 using the first position measurement system 30 (and the second position measurement system 50), while detecting the wafer W using the mark detection system MDS. 11 The I first mark images on the wafer W are detected, and the wafer W is calculated based on the detection results of the I first mark images and the absolute position coordinates (X, Y) of the slider 10 at the time of detection of each of the I first mark images. 11 The absolute position coordinates in the XY plane of each of the I first mark images are calculated. In this case, however, detection light in the red wavelength range determined by the second condition is irradiated onto the wafer mark through the optical system of the mark detection system MDS under conventional illumination conditions (σ value) with the light amount set by default, and diffracted light of a predetermined order (for example, ±1st order) generated from the wafer mark is received by a detector, and the photoelectric conversion signal is processed according to the signal processing conditions (processing algorithm) set by default, thereby obtaining the absolute position coordinates of the wafer W. 11 The detection results of the marks are obtained, which are used to calculate the position coordinates of the wafer marks on the reference coordinate system. At this time, the control device 604 calculates the absolute position coordinates in the XY plane of each of the I first mark images, using as offsets the Abbe errors in the X-axis and Y-axis directions of the first position measurement system 30 and the measurement values ​​in the X-axis and Y-axis directions of the second position measurement system 50, which are obtained based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30.

[0219] Next, in step S324, the wafer W 11 is unloaded from the slider 10 of the measuring device 1004 and loaded onto the slider 10 of the measuring device 1005 without being carried out to the outside of the measuring system 5002. 11 Under the control of the control device 604, the wafer W is unloaded from the slider 10 of the measuring device 1004 by the wafer transport system 704 and the vertically moving member on the slider 10 in the reverse order of the loading procedure in step S318 (and step S104), and then transferred to the transfer member 524 (or 526) by the wafer transport system 704, and then transferred to the transfer position with the measuring device 1005 by the transfer member 524 (or 526). Thereafter, under the control of the control device 605, the wafer W is transferred to the slider 10 of the measuring device 1005 by the wafer transport system 705 and the vertically moving member on the slider 10 in the same order as in the above-mentioned step S104. 11 is loaded onto the slider 10 of the measurement device 1005.

[0220] Next, in step S326, the wafer W is measured by the measuring device 1005. 11 The measurement conditions for the second mark image are set to a second predetermined condition. Hereinafter, this second predetermined condition will also be referred to as a third condition. The third condition is set to a condition where the wafer W is exposed to the second layer. 11 These are measurement conditions suitable for detecting the second mark image formed on the wafer W. Here, as in the above, the alignment measurement condition (an example of the third condition) is to optimize the wavelength of the illumination light in the mark detection system MDS. 11 The second mark image formed in is a mark formed on the second layer (outermost layer), and there is no need to limit the wavelength of the observation light (illumination light) to observe it, and it can be observed with broadband white light emitted from an illumination light source such as a halogen lamp. Therefore, the control device 605 sets (controls) the wavelength selection mechanism of the mark detection system MDS so that a filter that transmits a light beam (white light) with a wavelength of 530 to 800 nm is selected in the wavelength selection mechanism.

[0221] Next, in step S328, the wafer W is heated under the third condition set by the control device 605. 11 The absolute position coordinates of the I second mark images in the XY plane are obtained in the same manner as the absolute position coordinates of the first mark image in the XY plane in step S322. At this time, the control device 605 obtains the absolute position coordinates of the I second mark images in the XY plane using, as offsets, the Abbe errors in the X-axis and Y-axis directions of the first position measurement system 30 and the measurement values ​​in the X-axis and Y-axis directions of the second position measurement system 50, which are obtained based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30.

[0222] Next, in step S330, the measurement system control device 5302 (or the control device 605) determines the overlay error (overlay deviation) between the first layer and the second layer based on the absolute position coordinates of the first mark image and the absolute position coordinates of the second mark image, which form a pair.

[0223] Next, in step S332, the measurement system control device 5302 (or the control device 605) determines whether the overlay error is mainly caused by the exposure of the first layer or the exposure of the second layer based on the absolute position coordinates of the I first mark images and the absolute position coordinates of the I second mark images, for example, as follows: That is, the measurement system control device 5302 (or the control device 605) determines the deviation amount (ΔX1 i ,ΔY1 i ) (i = 1 to I), and the deviation amount (ΔX2 i ,ΔY2 i ) (i=1~I) and ΔX1 i , ΔX2 i , ΔY1 i , ΔY2 i For each i=1~I, the sum ΣΔX1 i , ΣΔX2 i , ΣΔY1 i , ΣΔY2 iThen, the measurement system control device 5302 (or the control device 605) calculates ΣΔX1 i >ΣΔX2 i and ΣΔY1 i >ΣΔY2 i In this case, it is determined that the overlay error is mainly caused by the exposure of the first layer in both the X-axis and Y-axis directions, and ΣΔX1 i <ΣΔX2 i and ΣΔY1 i <ΣΔY2 i In this case, it is determined that the overlay error is mainly caused by the exposure of the second layer in both the X-axis direction and the Y-axis direction. i >ΣΔX2 i and ΣΔY1 i <ΣΔY2 i In this case, it is determined that the overlay error is primarily due to the exposure of the first layer in the X-axis direction and primarily due to the exposure of the second layer in the Y-axis direction, and ΣΔX1 i <ΣΔX2 i and ΣΔY1 i >ΣΔY2 i In this case, the overlay error is determined to be primarily due to the exposure of the second layer in the X-axis direction and primarily due to the exposure of the first layer in the Y-axis direction.

[0224] The above-mentioned determination method is merely an example, and the point is that the specific determination method is not particularly limited as long as the measurement system control device 5302 (or the control device 605) determines whether the overlay error is primarily caused by the exposure of the first layer or the exposure of the second layer based on the absolute position coordinates of the I first mark images and the absolute position coordinates of the I second mark images.

[0225] In parallel with the processing of steps S330 and S332, the wafer W after the measurement of the absolute position coordinates in the XY plane of the I second mark images in step S328 is 11is delivered to the transport member 526 by the wafer transport system 705, and is transported by the transport member 526 to the unload side wafer transfer position described above, and then is returned to the predetermined FOPU 520 by the robot 516.

[0226] The wafer W obtained by the above-mentioned overlay measurement method 11 The data on the overlay error (overlay deviation) and the data on the determination result as to whether the overlay error is primarily due to the exposure of the first layer or the exposure of the second layer are fed back by the measurement system control device 5302 (or control device 605) to at least one of the exposure device that performed the exposure of the first layer and the exposure device 200 that performed the exposure of the second layer.

[0227] For example, if the main cause of the overlay error is the exposure of the first layer, the data may be fed back to the exposure tool that performed the first layer. 11 For wafers included in a lot other than the lot containing wafer W 11 When performing the same exposure process as for the first layer, a positioning target position may be determined based on the fed-back data so as to reduce the overlay error with the second layer.

[0228] Furthermore, if the main cause of the overlay error is the exposure of the second layer, the data may be fed back to the exposure tool 200 that performed the exposure of the second layer. 11 For wafers included in a lot other than the lot containing wafer W 11 When performing the same exposure process as for the second layer, a positioning target position may be determined based on the fed-back data so as to reduce the overlay error with the first layer.

[0229] The data may be fed back via the host computer 2000.

[0230] In addition, in at least one of steps S322 and S328, the wafer W11 When absolute position coordinates of two or more marks are obtained for all shots on the first layer, and at least one of first information regarding the shape and size of each shot on the first layer and second information regarding the shape and size of each shot on the second layer can be obtained, the first information may be provided (feedback) to the exposure apparatus that exposed the first layer, and the second information may be provided (feedback) to exposure apparatus 200 that exposed the second layer. In this case, imaging characteristic correction controller 248 may be controlled, or at least one of the speed and direction of reticle stage RST may be controlled, so that the shape and size of each shot on the second layer become as desired.

[0231] In the above explanation, the overlay error (overlay misalignment) between the first layer and the second layer is found based on the absolute position coordinates of the first mark image and the absolute position coordinates of the second mark image, but the data on the absolute position coordinates of the first mark image and the data on the absolute position coordinates of the second mark image may be output from measurement system 5002 as information on the overlay error (position misalignment between the first layer and the second layer). In this case, the data output from measurement system 5002 may be provided (feedback) to at least one of the exposure apparatus (exposure apparatus 200 or another exposure apparatus) that performed the exposure of the first layer and exposure apparatus 200 that performed the exposure of the second layer.

[0232] Furthermore, the positional shift between the paired first and second mark images may be calculated based on the absolute position coordinates of the first and second mark images, and the data on this positional shift may be output as information on the overlay error between the first and second layers (positional shift between the first and second layers) from measurement system 5002. In this case as well, the data output from measurement system 5002 may be provided (feedback) to at least one of the exposure apparatus (exposure apparatus 200 or another exposure apparatus) that performed the exposure of the first layer and exposure apparatus 200 that performed the exposure of the second layer.

[0233] In the processing algorithm according to the flowcharts of FIGS. 13 and 14, all the substrates (wafers W) included in the same lot that are the subject of overlay measurement are11 ), when the measurement of the absolute position coordinates of the first mark image is performed by the measurement device 1004 in step S322, the measurement of the absolute position coordinates of the second mark image is performed by the measurement device 1005 for that overlay measurement target substrate in step S328, but it is not necessarily necessary to measure the absolute position coordinates of the second mark image by the measurement device 1005 for some of the measurement target substrates in the lot.

[0234] Alternatively, in step S322, absolute position coordinates of K first mark images (less than I) may be obtained, and in step S328, absolute position coordinates of K second mark images may be obtained.

[0235] As is clear from the above description, according to the overlay measurement method performed in substrate processing system 1000, measurement system 5002 can measure the absolute position coordinates of the first mark image and the absolute position coordinates of the second mark image, and can measure the overlay error based on these absolute position coordinates. Furthermore, it is possible to obtain an excellent effect not previously available, that is, it is possible to identify whether the overlay error is mainly caused by exposure of the lower layer or the upper layer.

[0236] In addition, since the overlay error (overlay deviation) between the first layer and the second layer is obtained in step S330, step S332 may be executed as needed.

[0237] In the above description, marks for measuring overlay deviation (first mark image, second mark image) are used to determine the overlay error between the first layer and the second layer, but wafer marks (alignment marks) may also be used. That is, the overlay error between the first layer and the second layer may be determined from the absolute position coordinates of I wafer marks on the first layer and the absolute position coordinates of I wafer marks on the second layer.

[0238] Furthermore, since the wafer mark and the marks for measuring the overlay deviation (first mark image, second mark image) are different in shape, size, etc., the suitable measurement conditions, including the irradiation conditions, etc., are different. Therefore, for multiple wafers included in the same lot (measurement target lot), in the above-mentioned step S320, 11 Instead of the measurement conditions for the first mark image in (1), measurement conditions suitable for measuring a resist image of a wafer mark on a wafer are set as first predetermined conditions, and in step S322, absolute position coordinates of the resist image of the wafer mark are obtained under the first predetermined conditions. Furthermore, for a wafer for which absolute position coordinates of the resist image of the wafer mark have been acquired, measurement conditions suitable for measuring a mark for overlay measurement (at least one of the first mark image and the second mark image) may be set as second predetermined conditions in the above-described step S326, and absolute position coordinates of the mark for overlay measurement may be obtained under the second predetermined conditions in step S328. Therefore, with the processing flow in accordance with the flowcharts of FIGS. 13 and 14, it is possible to perform highly accurate position measurements of both the resist images of the wafer marks and the marks for overlay measurement for multiple wafers included in a measurement target lot.

[0239] In the above description, after the exposure process of the second layer, the developed wafer W is measured by the measurement device 1004 of the measurement system 5002. 11 The absolute position coordinates of the first mark image (or the wafer mark of the first layer) are acquired by the measuring device 1005, and the absolute position coordinates of the second mark image (or the wafer mark of the second layer) are acquired by the measuring device 1005. However, the present invention is not limited to this, and the absolute position coordinates of the second mark image (or the wafer mark of the second layer) may be acquired by the measuring device 1005 after the exposure process of the first layer and before the exposure process of the second layer. 11 The absolute position coordinates of the first mark image (or the wafer mark of the first layer) are acquired by the measurement device 1004 of the measurement system 5002, and after the exposure process of the second layer, the developed wafer W 11The absolute position coordinates of the second mark image (or the wafer mark of the second layer) may be acquired by the measurement device 1005 of the measurement system 500. In this case, the overlay error between the first layer and the second layer may be determined by the measurement system 5002 (the control device 605 or the measurement system control device 5302) or by another device (for example, the host computer 2000).

[0240] In addition, in order to perform the exposure process for the layer next to the second layer, the wafer W 11 wafer W is subjected to various processes (including etching and film formation processes) and then transported into C / D 300 (or another C / D). 11 is carried into the measurement system 5001 or the measurement system 5002, and one of the measurement devices 100 i (i = 1 to 6), wafer W 11 the absolute position coordinates of the first mark image (or the wafer mark on the first layer) and the absolute position coordinates of the second mark image (or the wafer mark on the second layer), or the absolute position coordinates of the wafer W 11 Alternatively, the absolute position coordinates of the second mark image (or the wafer mark of the second layer) may be acquired. In this case, too, the overlay error between the first layer and the second layer (misalignment between the first layer and the second layer) may be determined by measurement system 5001 or measurement system 5002, or information on the absolute position coordinates acquired by measurement system 5001 or measurement system 5002 may be provided to another device (e.g., host computer 2000), and the overlay error between the first layer and the second layer (misalignment between the first layer and the second layer) may be determined by that other device. Furthermore, information on the overlay error between the first layer and the second layer (misalignment between the first layer and the second layer) determined by measurement system 5001 or measurement system 5002, or information on the absolute position coordinates acquired by measurement system 5001 or measurement system 5002 may be provided to exposure apparatus 200 or another exposure apparatus.

[0241] In the above description, information on the overlay error between the first layer and the second layer is acquired, but this is not limiting, and the overlay error between the mth layer (lower layer, m is an integer equal to or greater than 1) and the nth layer (upper layer, n is an integer equal to or greater than 2 and greater than m) may also be acquired. In this case, the nth layer does not have to be the layer next to the mth layer.

[0242] As described above, in the substrate processing system 1000 according to this embodiment, a large number of wafers are successively processed by each of the measurement system 5001, the measurement system 5002, and the lithography system including the exposure apparatus 200 and the C / D 300. In the substrate processing system 1000, the measurement process described above on the wafer to be measured by the measurement system 5001, the processing (resist coating, exposure, and development) by the lithography system on the wafer after measurement by the measurement system 5001, and the measurement process on the wafer after processing by the lithography system are performed independently of each other. Therefore, although there is a constraint that processing by the lithography system is performed on the wafer after measurement processing by the measurement system 5001, and measurement processing by the measurement system 5002 is performed on the wafer after processing by the lithography system, an overall processing sequence can be determined to maximize the throughput of the substrate processing system 1000 as a whole.

[0243] Furthermore, according to the substrate processing system 1000, the measurement device 100 of the measurement system 5001 performs the measurement independently of the processing operation of the target wafer by the exposure apparatus 200, which includes the simple EGA measurement and exposure described above. i This allows alignment measurement of the target wafer, and enables efficient processing with almost no decrease in throughput of wafer processing by exposure apparatus 200. Also, as for the substrate processing system 1000 as a whole, the measuring apparatus 100 of the measuring system 5001 i The alignment and exposure process by exposure apparatus 200 for a certain lot of wafers for which measurement processing has been performed in advance by measurement apparatus 100 of measurement system 5001 is performed. iBy performing measurement processing of wafers of another lot by measurement system 5001 and measurement processing of wafers of yet another lot for which processing by the lithography system has been completed by measurement system 5002 in parallel, efficient processing can be achieved with almost no decrease in wafer processing throughput. Moreover, measurement system 5001 can perform all shot EGA, with all shots as sample shots, on wafers of a certain lot in parallel with wafer alignment and exposure operations on wafers of another lot by exposure apparatus 200.

[0244] Also, the measurement device 100 of the measurement system 5001 i In the cases where i=1 to 3, all shots are used as sample shots for EGA, which is performed prior to wafer alignment and exposure operations by the exposure tool 200 for wafers from the same lot for which pre-processing steps in wafer processing (etching, oxidation / diffusion, film formation, ion implantation, planarization (CMP), etc.) have been completed (more precisely, prior to resist coating on the wafers), and alignment history data including wafer grid information (e.g., data on deformation components of the wafer grid) is acquired for each wafer obtained by alignment measurement. The acquired alignment history data for each wafer is stored in an internal storage device by the measurement system control device 5301 for each wafer. Therefore, the exposure tool 200 can effectively utilize the alignment history data including wafer grid information for the target wafer, which is obtained using the measurement system control device 5301, to perform wafer alignment and exposure on the target wafer. That is, in the substrate processing system 1000 according to this embodiment, the measurement tool 100 of the measurement system 5001 i It can be said that alignment history data for the target wafer obtained in the pre-measurement process (i=1 to 3), including information on the wafer grid (e.g., data on the deformation components of the wafer grid), is transferred (provided) to the exposure apparatus 200 in a substantially feedforward manner.

[0245] Also, the measuring device 100 iThe coefficients of the high-order components in the model formula obtained by EGA of all shots in the pre-measurement process in (i=1 to 3) can be used as they are in the exposure tool 200. Therefore, in the exposure tool 200, alignment measurement is performed using several shots as alignment shots to find the coefficients of the low-order components in the model formula. The coefficients of these low-order components and the measurement tool 100 i By using the coefficients of the higher-order components acquired in (a) and (b), it is possible to determine not only the coefficients of the lower-order components (undetermined coefficients) of model equation (1), but also the coefficients of the higher-order components (undetermined coefficients). Using model equation (1) with the determined undetermined coefficients (i.e., equation (3) above) and the design values ​​(X, Y) of the array of multiple shots on the wafer, it is possible to calculate correction amounts from the design positions of each shot. This makes it possible to obtain correction amounts with the same accuracy as when the coefficients of the lower- and higher-order components of model equation (1) are calculated in exposure apparatus 200. Then, based on this correction amount and the design values ​​of the array of multiple shots on the wafer, it is possible to calculate the positioning target position for exposure of each shot. Therefore, by controlling the position of wafer stage WST according to this target position, it is possible to accurately align each shot with the exposure position (projection position of the reticle pattern). This makes it possible to improve the overlay accuracy of the reticle pattern image and the pattern formed in each shot area on the wafer during exposure without reducing the throughput of exposure apparatus 200.

[0246] Furthermore, the measuring device 100 according to this embodiment i (i=1 to 6), the control device 60 i While controlling the movement of the slider 10 by the drive system 20, the measuring apparatus 100 uses the first position measurement system 30 and the second position measurement system 50 to obtain position information of the slider 10 with respect to the surface plate 12 and relative position information between the mark detection system MDS and the surface plate 12, and also obtains position information of a plurality of marks formed on the wafer W using the mark detection system MDS. i According to this, position information of a plurality of marks formed on the wafer W can be obtained with high precision.

[0247] Furthermore, the measuring device 100 according to this embodiment i (i=1 to 6), the control device 60 i The control device 60 constantly acquires measurement information (relative position information between the surface plate 12 and the mark detection system MDS) from the second position measurement system 50, and controls the position of the surface plate 12 in the six degrees of freedom directions in real time via the three vibration isolation devices 14 (actuators thereof) so that the positional relationship between the detection center of the mark detection system MDS and the detection point of the first position measurement system 30, which detects position information of the slider 10 in the six degrees of freedom directions relative to the surface plate 12, is maintained at a desired relationship at the nm level. i While controlling the driving of the slider 10 by the driving system 20, the measuring apparatus 100 acquires measurement information by the first position measurement system 30 (position information of the slider 10 relative to the surface plate 12) and measurement information by the second position measurement system 50 (relative position information between the surface plate 12 and the mark detection system MDS), and determines position information of a plurality of wafer marks based on a detection signal when marks formed on the wafer W are detected using the mark detection system MDS, measurement information by the first position measurement system 30 obtained when marks formed on the wafer W are detected using the mark detection system MDS, and measurement information by the second position measurement system 50 obtained when marks formed on the wafer W are detected using the mark detection system MDS. i According to this, position information of a plurality of marks formed on the wafer W can be obtained with high precision.

[0248] Note that, for example, in cases where EGA calculations are not performed using the position information of the measured marks and the position of the wafer W (wafer stage WST) during exposure is controlled based on the measured position information of the marks, the measurement information by the second position measurement system 50 does not need to be used to calculate the position information of the marks. In this case, however, the measurement information by the second position measurement system 50 obtained when marks formed on the wafer W are detected using the mark detection system MDS can be used with an offset to correct information for moving the wafer W, such as the positioning target value of the wafer W (wafer stage WST). Alternatively, the movement of the reticle R (reticle stage RST) during exposure can be controlled taking the offset into consideration.

[0249] Furthermore, the measuring device 100 according to this embodiment i According to (i=1 to 6), the first position measurement system 30, which measures the position information of the slider 10 on which the wafer W is placed and held in six degrees of freedom, detects at least the wafer mark on the wafer W using the mark detection system MDS, and therefore can continue to irradiate the measurement beam from the head unit 32 onto the grating RG1 within the range in which the slider 10 moves. Therefore, the first position measurement system 30 can continuously measure the position information within the entire range in the XY plane in which the slider 10 moves for mark detection. Therefore, for example, the measurement device 100 i During the manufacturing stage (including the stage of starting up the equipment in a semiconductor manufacturing factory), by determining the origin of an orthogonal coordinate system (reference coordinate system) defined by the measurement axis of the first position measurement system 30, it is possible to manage, on the reference coordinate system, the absolute position of the slider 10, and in turn the absolute positions of marks (not limited to search marks and wafer marks, but also other marks such as overlay measurement marks (registration marks)) on the wafer W held on the slider 10, which are determined from the position information of the slider 10 and the detection results of the mark detection system MDS.

[0250] As is clear from the above description, the substrate processing system 1000 according to this embodiment includes measurement systems 5001 and 5002. Even if the exposure apparatus 200 only has the capability to perform simple EGA measurement (e.g., acquiring position information for approximately 3 to 16 wafer marks using alignment system AS) to determine linear components of the correction amount for the wafer position coordinates within a predetermined time (the time allowed for maintaining the required high throughput), the wafer grid deformation can be determined with high accuracy using the low-order components of the wafer grid deformation obtained by performing the simple EGA measurement and the high-order components of the wafer grid deformation determined in advance by measurement system 5001 (or measurement system 5002), for example, by all-point EGA. Therefore, measurement system 5001 (or measurement system 5002) can substantially improve the grid correction function of exposure apparatus 200. Therefore, high-precision exposure can be performed on wafers at high throughput or without reducing throughput using an exposure apparatus that does not have cutting-edge grid correction functionality.

[0251] In the substrate processing system 1000 according to the above embodiment, the measuring device 100 i Although the case where the C / D 300 and the exposure tool 200 are equipped with a barcode reader has been described, instead of a barcode reader, they may be equipped with a writing / reading device for an RFID tag, which is a wireless IC tag. In such a case, an RFID tag is attached to each wafer, and the RFID tag is read by the measurement tool 100. i uses a write / read device to write the above-mentioned alignment history data for each wafer to an RFID tag, and another device, for example, exposure tool 200, uses a write / read device to read the alignment history data from the RFID tag of the target wafer, thereby easily realizing feedforward transfer of the above-mentioned alignment history data for the target wafer.

[0252] Furthermore, in the substrate processing system 1000 according to the above embodiment, the exposure apparatus 200 calculates the coefficients of the low-order components of the model formula, and the coefficients of the low-order components and the measurement apparatus 100 iIn the above description, the coefficients of the second-order or higher components of the model equation obtained by the measurement apparatus 100 are used. However, the present invention is not limited to this. For example, the coefficients of the second-order or lower components of the model equation may be obtained from the detection results of the alignment marks in the exposure apparatus 200, and the coefficients of the second-order or lower components may be used in the measurement apparatus 100. i Alternatively, for example, the coefficients of the third-order or lower components of the model equation may be obtained from the detection results of the alignment marks in the exposure tool 200, and the coefficients of the third-order or lower components and the measurement tool 100 may be used. i In other words, the coefficients of the (N-1)th order (N is an integer of 2 or more) or lower components of the model equation obtained by the exposure tool 200 may be calculated from the alignment mark detection results in the exposure tool 200, and the coefficients of the (N-1)th order or lower components and the measurement tool 100 may be used. i The coefficients of the Nth or higher order components of the model equation obtained in step (2) may also be used.

[0253] In the above embodiment, the measuring device 100 i (i=1 to 3) expresses the relationship between the design position coordinates X, Y of each shot in the wafer coordinate system (corresponding to the reference coordinate system) and the correction amount (alignment correction component) dx, dy of the position coordinate of that shot. In model equation (1), coefficients a3, a4, a5... and b3, b4, b5... of the second or higher order components, as well as coefficients a0, a1, a2, b0, b1, b2 of the first or lower order components are also calculated. However, since the coefficients of the low order components are calculated in exposure tool 200, measurement tool 100 i In this case, it is not necessary to obtain the coefficients of the low-order components.

[0254] In the substrate processing system 1000 according to this embodiment, the measuring device 100 i When the measurement unit 40 is equipped with the above-mentioned multi-point focal position detection system, the measurement device 100 iIn this case, by using the results of the flatness measurement, it is possible to perform focus and leveling control of the wafer W during exposure without performing flatness measurement using the exposure apparatus 200.

[0255] In the above embodiment, the measuring apparatuses 1001, 1002, and 1003 of the measurement system 5001 have the same configuration and function, and for example, 25 wafers included in the same lot are divided into, for example, three groups. The wafers in each group are used as measurement targets for the measuring apparatuses 1001, 1002, and 1003, and the same alignment measurement processes are performed in parallel. However, the measuring apparatuses 1001, 1002, and 1003 may perform the same alignment measurement processes on wafers in different lots in parallel. For example, the measuring apparatus 1002 may measure wafers in a lot that will be exposed by the same exposure apparatus (e.g., exposure apparatus 200) after the lot being measured by the measuring apparatus 1001, and the measuring apparatus 1003 may measure wafers in a lot that will be exposed by the same exposure apparatus (e.g., exposure apparatus 200) after the lot being measured by the measuring apparatus 1002.

[0256] In the above embodiment, from the viewpoint of prioritizing throughput, the measurement processing for 25 wafers in the same lot is shared among the three measuring devices 1001, 1002, and 1003 of the measurement system 5001, and parallel processing is performed. However, when measurement accuracy is prioritized over throughput, the same measuring device 100 iIt is desirable to perform the above-mentioned measurement process on 25 wafers of the same lot by using three or two measuring devices 1001, 1002, and 1003 (i = 1 to 3). The reason for this is that even if measuring devices 1001, 1002, and 1003 are equipped with wafer holders that are the same product, there are individual differences between wafer holders, and the suction state varies slightly, which can cause measurement errors in measuring devices 1001, 1002, and 1003. Taking this into consideration, it is desirable to perform the above-mentioned measurement process on 25 wafers of the same lot by using three or two measuring devices 1001, 1002, and 1003 of measuring system 5001. i When the measurement is shared among the three or two measuring devices 100 of the measurement system 5001, the measurement error due to the individual difference of the wafer holder may be obtained in advance by, for example, measuring the flatness of the wafer holder using the same super flat wafer. i Even if the measurement is not shared among the wafer holders, a super flat wafer may be used to determine in advance the measurement error due to the individual difference between the wafer holders. i Regardless of whether the measurement is shared among the measurement devices or not, a superflat wafer is used and the measurement device 100 i The measurement error due to the individual difference of the wafer holders (i=4 to 6) may be calculated in advance.

[0257] Furthermore, the three measuring tools 1004 to 1006 of the measuring system 5002 may be adjusted, for example, using a reference wafer, so that when one wafer in one lot is measured under the same conditions by each of the three measuring tools 1004 to 1006, substantially the same measurement results are obtained.

[0258] It is also desirable that the user of the measurement system 5001 be able to select whether to prioritize the throughput or the measurement accuracy. i It is necessary to consider the operation efficiency of the measuring devices 1001, 1002, and 1003, and it is not always the case that all of the measuring devices 1001, 1002, and 1003 are available (in a non-operating state) at the same time.i Only when two or more measurement tools 100 are available at the same time, can wafers from the same lot be measured by the two or more measurement tools 100. i It may be possible to divide it into:

[0259] Furthermore, for example, at least one of measuring devices 1001, 1002, and 1003 of measurement system 5001 may be a measuring device with a different function from the other measuring devices. For example, one measuring device may be a measuring device equipped with a multi-point focal position detection system that measures the unevenness (flatness) of the wafer surface, or may be a wafer shape measuring device. Furthermore, at least one of measurement systems 5001 and 5002 may be equipped with two, four, or more measuring devices.

[0260] Furthermore, in the above embodiment, wafers in the same lot are the measurement targets of measuring apparatus 1001 of measurement system 5001 and also the measurement targets of measuring apparatus 1002. However, this is not limiting, and wafers in one lot (e.g., a lot sent to exposure apparatus 200) may be the measurement target of measuring apparatus 1001, and wafers in another lot (e.g., a lot sent to an exposure apparatus other than exposure apparatus 200) may be the measurement target of measuring apparatus 1002. In this case, measuring apparatus 1001 may set measurement conditions (first predetermined conditions) suitable for measuring marks on wafers in the measurement target lot, and then measure the marks on the measurement targets, and measuring apparatus 1002 may set measurement conditions (second predetermined conditions) suitable for measuring marks on wafers in the measurement target lot, and then measure the marks on the measurement targets.

[0261] Furthermore, in the above embodiment, when measuring overlay errors, wafers in the same lot are the measurement targets of measuring apparatus 1004 of measurement system 5002, and also the measurement targets of measuring apparatus 1005. However, this is not limiting, and wafers in one lot may be the measurement targets of measuring apparatus 1004, and wafers in another lot may be the measurement targets of measuring apparatus 1005. In this case, measuring apparatus 1004 may measure the marks on wafers in the measurement target lot after setting measurement conditions (first predetermined conditions) suitable for measuring marks on wafers in the measurement target lot, and measuring apparatus 1005 may measure the marks on wafers in the measurement target lot after setting measurement conditions (second predetermined conditions) suitable for measuring marks on wafers in the measurement target lot.

[0262] In addition, if the measuring device 5006 of the measuring system 5002 has the same configuration and function as at least one of the measuring devices 5004 and 5005, the measuring device 5006 can be used in place of one or both of the measuring devices 5004 and 5005.

[0263] In the above embodiment, the substrate processing system 1000 is described as including a measurement system 5001 having a plurality of, for example, three measuring devices 1001 to 1003, and a measurement system 5002 having a plurality of, for example, three measuring devices 1004 to 1006, in order to maximize the throughput of the entire substrate processing system 1000. However, since the measurement systems 5001 and 5002 have the same configuration, in the above embodiment, the role played by the measurement system 5001 can be taken over by the measurement system 5002, and the role played by the measurement system 5002 can also be taken over by the measurement system 5001. Therefore, if a slight decrease in the throughput of the entire substrate processing system 1000 is acceptable, the substrate processing system 1000 may include only one of the measurement systems 5001 and 5002, for example, only the measurement system 5001. In this case, if the measurement system 5001 has four or more measurement devices 100, two of them may be made to perform the roles of measurement devices 1001 and 1002 in the above-mentioned embodiment, and the remaining two may be made to perform the roles of measurement devices 1004 and 1005.

[0264] In the above embodiment, the case where overlay error measurement is performed using measurement system 5002 has been exemplified, but the present invention is not limited to this. Measurement system 5002 may simply acquire alignment information (absolute position information, grid information, etc.) of the wafer after exposure and development in addition to overlay error measurement. Furthermore, measurement system 5002 may measure wafers of the same lot using multiple measurement tools 100 in the same manner as measurement system 5001. i (i=at least two of 4, 5, 6)

[0265] Furthermore, in the substrate processing system 1000 according to the above embodiment, the measurement systems 5001 and 5002 are not in-line connected to either the exposure apparatus 200 or the C / D 300. However, one of the measurement systems 5001 and 5002, for example, the measurement system 5002, may be in-line connected to one or both of the exposure apparatus 200 and the C / D 300. For example, the C / D 300 and the measurement system 5002 may be in-line connected so that the C / D 300 is disposed between the exposure apparatus 200 and the measurement system 5002. Alternatively, the measurement system 5002 may be in-line connected to both the exposure apparatus 200 and the C / D 300 so that it is disposed between the exposure apparatus 200 and the C / D 300. In this case, the measurement system 5002 does not need to be equipped with the carrier system 510.

[0266] In the above embodiment, one of the measurement systems 5001 and 5002 includes a plurality of measurement devices 100. i For example, the measurement system 5001 may not include a plurality of measurement devices 100. i and measurement system 5002 may include only one measurement device. In this case, the measurement processes (at least one of wafer grid measurement process and overlay deviation measurement process) performed by a plurality of measurement devices on wafers in the same lot as described above may be performed using measurement system 5001. Also, in this case, a general overlay measurement device may be used instead of measurement system 5002.

[0267] In the above embodiment, the measurement device 100 of the measurement system 5001 i The case has been described where the exposure apparatus 200 effectively utilizes the data on the deformation components of the wafer grid for each wafer acquired in (i=1 to 3) and the alignment history data file as preliminary measurement data. However, the present invention is not limited to this. iThe measurement system control device 5301 (or the analysis device 3000) may obtain process control data based on the data of the deformation component of the wafer grid for each wafer acquired in the alignment history data file, and may transmit this process control data to the host computer 2000 in a feedback manner. i Representative examples of process control data obtained from the data acquired by the measurement device 100 include control data for the film forming device 2300 such as a CVD device, or the CMP device 2200. i (i=1 to 3) is provided with a signal processing device 49 that processes the detection signals of the mark detection system MDS, and selects only the data of the measurement results of the wafer marks that have good waveforms of the detection signals obtained as the detection results of the mark detection system MDS, and outputs the result to the control device 60 i In other words, the signal processing device 49 also acquires the measurement results of wafer marks whose detection signal waveforms are not good. Therefore, the measurement system control device 5301 (or the analysis device 3000) may acquire data on the measurement results of all wafer marks, including the measurement results of wafer marks whose detection signal waveforms are not good, from the signal processing device 49, and calculate process control data based on this data. Alternatively, the signal processing device 49 may send the data on the measurement results of all wafer marks to the control device 60. i and the control device 60 judges whether the detection signal obtained as a result of detection by the mark detection system MDS is good or not. i In this case, the control device 60 i may send data on the measurement results of all wafer marks, including the measurement results of wafer marks not used in the EGA calculation, to the measurement system control device 530 (or the analysis device 3000), and the measurement system control device 5301 (or the analysis device 3000) may then calculate process control data based on the sent data.

[0268] In the above embodiment, the target is a 300 mm wafer, but the target is not limited to this, and may be a 450 mm wafer with a diameter of 450 mm, or a 200 mm wafer with a diameter of 200 mm. i Since wafer alignment can be performed by this, whether the wafer is a 450 mm wafer or a 200 mm wafer, all-point EGA measurement, for example, is possible without reducing the throughput of the exposure process. Note that in at least one of measurement systems 5001 and 5002, one measurement device may measure wafers of different diameters, while the other measurement device may measure wafers of different diameters. For example, measurement device 1001 of measurement system 5001 may be used for 300 mm wafers, and measurement device 1002 may be used for 450 mm wafers.

[0269] The measuring device 100 according to the above embodiment i Although the case where the gratings RG1, RG2a, and RG2b each have periodic directions in the X-axis direction and the Y-axis direction has been described above, this is not limiting, and the grating sections (two-dimensional gratings) provided in each of the first position measurement system 30 and the second position measurement system 50 may have periodic directions in two directions that intersect with each other in the XY plane.

[0270] Furthermore, the measuring device 100 described in the above embodiment i The above configuration is merely an example. For example, the measurement device may have a stage (slider 10) that is movable relative to a base member (surface plate 12) and may be configured to measure position information of a plurality of marks on a substrate (wafer) held on the stage. Therefore, the measurement device does not necessarily have to include, for example, the first position measurement system 30 and the second position measurement system 50.

[0271] Of course, the configuration of the head unit 32 and the arrangement of the detection points of the first position measurement system 30 described in the above embodiment are merely examples. For example, the detection point of the mark detection system MDS and the detection center of the head unit 32 do not have to be aligned in at least one of the X-axis direction and the Y-axis direction. The arrangement of the head unit and the grating RG1 (grating unit) of the first position measurement system 30 may be reversed. That is, the head unit may be provided on the slider 10, and the grating unit may be provided on the surface plate 12. The first position measurement system 30 does not necessarily have to include the encoder system 33 and the laser interferometer system 35, and may be configured using only an encoder system. The first position measurement system may also be configured using an encoder system that irradiates a beam from the head unit onto the grating RG1 of the slider 10, receives a return beam (diffracted beam) from the grating, and measures position information of the slider 10 in six degrees of freedom relative to the surface plate 12. In this case, the configuration of the head of the head unit is not particularly important. The first position measurement system 30 does not necessarily need to be able to measure position information of the slider 10 in six degrees of freedom relative to the surface plate 12, and may be able to measure position information only in the X, Y, and θz directions, for example. Furthermore, the first position measurement system that measures the position information of the slider 10 relative to the surface plate 12 may be disposed between the surface plate 12 and the slider 10. Furthermore, the first measurement system may be configured by an interferometer system or other measurement device that measures position information of the slider 10 in six degrees of freedom relative to the surface plate 12 or in three degrees of freedom in a horizontal plane.

[0272] Similarly, the configuration of the second position measurement system 50 described in the above embodiment is merely an example. For example, the head units 52A and 52B may be fixed to the surface plate 12, and the scales 54A and 54B may be provided integrally with the mark detection system MDS. The second position measurement system 50 may include only one head unit, or may include three or more head units. In any case, it is desirable that the second position measurement system 50 be able to measure the positional relationship between the surface plate 12 and the mark detection system MDS in six degrees of freedom. However, the second position measurement system 50 does not necessarily have to be able to measure the positional relationship in all six degrees of freedom.

[0273] In the above embodiment, the slider 10 is supported by a plurality of air bearings 18 in a floating manner above the base 12, and the driving system 20 includes a first driving device 20A that drives the slider 10 in the X-axis direction and a second driving device 20B that drives the slider 10 in the Y-axis direction integrally with the first driving device 20A, and drives the slider 10 in a non-contact state relative to the base 12. However, the present invention is not limited to this, and a driving system configured to drive the slider 10 in six degrees of freedom above the base 12 may also be used as the driving system 20. For example, such a driving system may be configured by a magnetically levitated planar motor. In such a case, the air bearings 18 are not required. The measuring device 100 i The vibration isolator 14 may be provided with a drive system for driving the surface plate 12 .

[0274] In the above embodiment, the measurement system 500 includes an EFEM system as the carrier system 510. However, instead of the EFEM system, a carrier storage device capable of storing multiple (for example, three) carriers (FOUPs, etc.) along the Y-axis direction may be installed. In this case, the measurement system 500 includes multiple measurement devices 100. i The system may also include a plurality of load ports provided adjacent to each of the above, and a carrier transport device that transfers carriers (FOUPs, etc.) between the carrier storage device and the placement sections of the plurality of load ports.

[0275] In the above embodiment, a case has been described in which C / D 300 is inline connected to exposure apparatus 200. However, instead of C / D 300, a coater that coats a substrate (wafer) with a photosensitive agent (resist) may be inline connected to exposure apparatus 200. In this case, the exposed wafer is carried into a developing apparatus that is not inline connected to the exposure apparatus. Alternatively, instead of C / D 300, a developing apparatus that develops the exposed substrate (wafer) may be inline connected to exposure apparatus 200. In this case, a wafer that has been previously coated with resist in a different location is carried into the exposure apparatus.

[0276] In the above embodiment, the exposure apparatus is described as a scanning stepper, but the present invention is not limited to this. The exposure apparatus may be a stationary exposure apparatus such as a stepper, or a step-and-stitch reduction projection exposure apparatus that combines shot areas. Furthermore, the above embodiment can also be applied to a multi-stage exposure apparatus equipped with multiple wafer stages, as disclosed in U.S. Patent Nos. 6,590,634, 5,969,441, and 6,208,407. Furthermore, the exposure apparatus is not limited to the dry-type exposure apparatus that exposes the wafer W without using the liquid (water) described above, but may also be an immersion-type exposure apparatus that exposes the substrate via a liquid such as those described in European Patent Application Publication No. 1420298, International Patent Application Publication No. WO2004 / 055803, International Patent Application Publication No. WO2004 / 057590, U.S. Patent Application Publication No. 2006 / 0231206, U.S. Patent Application Publication No. 2005 / 0280791, U.S. Patent No. 6,952,253, etc. Furthermore, the exposure apparatus is not limited to exposure apparatuses used in semiconductor manufacturing, but may also be, for example, an exposure apparatus for liquid crystals that transfers a liquid crystal display element pattern onto a rectangular glass plate.

[0277] Semiconductor devices are manufactured through a lithography step in which a photosensitive object is exposed using a reticle (mask) on which a pattern is formed, and the exposed photosensitive object is developed, in an exposure apparatus that constitutes part of the substrate processing system according to each of the above embodiments. In this case, highly integrated devices can be manufactured with a high yield.

[0278] As shown in Figure 14, the manufacturing process of a semiconductor device may include, in addition to the lithography step, a step of designing the device's functions and performance, a step of producing a reticle (mask) based on this design step, a device assembly step (including a dicing step, a bonding step, and a packaging step), an inspection step, etc.

[0279] All disclosures of publications, international publications, US patent application publications, US patent specifications, and other documents relating to exposure apparatuses and the like cited in the above embodiments are incorporated herein by reference. [Explanation of symbols]

[0280] 10...slider, 12...surface plate, 14...vibration isolator, 16...base frame, 18...air bearing, 20...drive system, 20A...first drive device, 20B...second drive device, 22a, 22b...mover, 23a, 23b...mover, 24...movable stage, 25a, 25b...stator, 26a, 26b...stator, 28A, 28B...X-axis linear motor, 29A, 29B...Y-axis linear motor, 30...first position measurement system, 32...head unit, 33...encoder system, 40...measurement unit, 48...vibration isolator, 50...second position measurement system, 52A, 52B...head unit, 60 i ...control device, 70 i ...wafer transport system, 100 i...measurement device, 200...exposure device, 300...C / D, 5001, 5002...measurement system, 510...EFEM system, 512...EFEM main body, 514...load port, 516...robot, 521...transport system, 524...loading transport member, 526...unloading transport member, 5301, 5302...measurement system control device, 1000...substrate processing system, MDS...mark detection system, RG1...grating, RG2a, RG2b...grating, W...wafer, WST...wafer stage.

Claims

1. A measurement system used in a microdevice manufacturing line, a measurement device that executes a measurement process to acquire position information of a plurality of marks formed on a substrate; a control device connected to the measurement device and communicating with the measurement device; The control device inputs data acquired by the measurement device during the measurement process, and acquires process control data to be used in a process performed prior to the measurement process based on the data.

2. The measurement system according to claim 1 , wherein the data includes a deformation component of an arrangement of a plurality of divided areas formed on the substrate in correspondence with the plurality of marks.

3. The measurement system according to claim 1 , wherein the data includes history data of the measurement process performed by the measurement device.

4. the measurement device acquires detection signals of the plurality of marks formed on the substrate in order to acquire position information of the plurality of marks; The measurement system according to claim 1 , wherein the data includes the detection signals corresponding to the plurality of marks.

5. the measurement device acquires detection signals of the plurality of marks formed on the substrate in order to acquire position information of the plurality of marks; 5. The measurement system according to claim 1, wherein the data includes at least one of deformation components of an arrangement of a plurality of divided areas formed on the substrate corresponding to the plurality of marks, history data of the measurement process performed by the measurement device, and the detection signals corresponding to each of the plurality of marks.

6. The measurement system according to claim 1 , wherein the control device outputs the process control data to a process processing device that executes the process processing in a feedback manner.

7. 7. The measurement system according to claim 6, wherein the control device is connected to a host computer connected to the process processing device, and the process control data is output to the process processing device via the host computer.

8. 8. The measurement system according to claim 6, wherein the process processing device includes at least one of a film forming device including a CVD device, a CMP device, and an exposure device.

9. 9. The measurement system according to claim 8, wherein the control device outputs position information of the plurality of marks as the process control data to the exposure device that formed the plurality of marks on the substrate in a feedback manner.

10. The measurement system according to any one of claims 1 to 9; an exposure apparatus having a substrate stage on which the substrate is placed after measurement processing of the position information of the plurality of marks has been completed by the measurement apparatus included in the measurement system, the exposure apparatus performs wafer alignment on the substrate placed on the substrate stage to acquire position information of a portion of the plurality of marks selected from the plurality of marks, and performs an exposure process to expose the substrate with an energy beam based on the position information of the plurality of marks acquired by the measurement apparatus and the position information of the portion of the marks acquired by the exposure apparatus.

11. the measurement process of the plurality of marks performed by the measurement device is performed after at least one of the process processes of cleaning, oxidation / diffusion, film formation, etching, ion implantation, and CMP, and before application of a photosensitive agent for a next exposure process; 11. The substrate processing system according to claim 10, wherein the process control data is output from the control device included in the measurement system to at least one of the process processing devices that performed the film formation process, the CMP process, and the exposure process.

12. a process processing device including at least one of an etching device, a CMP device, and a film forming device for performing a process on a substrate; The measurement system according to claim 1 , wherein the measurement process is performed on the substrate; an exposure apparatus that performs an exposure process on the substrate placed on a substrate stage; a host computer connected to the measurement system, the exposure apparatus, and the process processing apparatus; A substrate processing system in which process control data generated based on the data acquired by the measurement device included in the measurement system during the measurement processing of the substrate is output in a feedback manner to at least one of the exposure device and the process processing device.

13. 13. The substrate processing system according to claim 12, wherein the data includes at least one of a deformation component of an arrangement of a plurality of divided regions formed on the substrate corresponding to the plurality of marks, history data of the measurement process performed by the measurement device, and a detection signal corresponding to each of the plurality of marks.

14. 14. The substrate processing system according to claim 12, wherein the process control data is output to the process processing device via the host computer.

15. further comprising an analysis device connected to the measurement system; 15. The substrate processing system of claim 14, wherein the process control data is acquired by the analysis device instead of the control device of the measurement system.

16. exposing the substrate using the exposure apparatus included in the substrate processing system according to any one of claims 10 to 15; The device manufacturing method further comprises developing the exposed substrate.

17. A measurement system used in a microdevice manufacturing line, a plurality of measurement devices that perform measurement processing to acquire position information of a plurality of marks formed on a substrate; a control device connected to the plurality of measurement devices and communicating with the measurement devices; the plurality of measurement devices include a first measurement device and a second measurement device, the first measurement device acquires first position information which is position information of a first plurality of marks, the second measurement device acquires second position information which is position information of a second plurality of marks different from the first plurality of marks, the first position information being acquired under a first predetermined condition set in the first measurement device, and the second position information being acquired under a second predetermined condition set in the second measurement device which is different from the first predetermined condition, The control device inputs data acquired by each of the measurement devices through the measurement process, and acquires process control data to be used in a process performed prior to each of the measurement processes based on the data.

18. the first measurement device acquires the first position information of the plurality of marks formed on an m-th layer (m is an integer equal to or greater than 1) of the substrate, and the second measurement device acquires the second position information of the plurality of marks formed on an n-th layer (n is an integer equal to or greater than 1 and different from m) of the substrate; 18. The measurement system of claim 17, wherein the control device acquires first process control data based on data provided by the first measurement device, and acquires second process control data based on data provided by the second measurement device.

19. 20. The measurement system of claim 18, wherein the control device outputs the first process control data to a process processing device used to process the mth layer in a feedback manner, and outputs the second process control data to a process processing device used to process the nth layer in a feedback manner.

20. 20. The measurement system according to claim 19, wherein the process processing device includes at least one of a film formation device including a CVD device, a CMP device, and an exposure device.

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