Measurement device, mark position measurement method, substrate processing system and exposure method

Abstract

The measurement system (500) for a micro-component production line includes: a plurality of measuring devices (1001-1003) for performing measurement processing on a substrate, and a control device (530) for controlling the plurality of measuring devices, wherein the plurality of measuring devices (1001-1003) includes at least one first measuring device for acquiring position information of a plurality of marks formed on the substrate.

Description

Technical Field

[0001] This invention relates to a measurement system, a substrate processing system, and a method for manufacturing components. More specifically, this invention relates to a measurement system for a micro-component production line, a substrate processing system including the measurement system, and a method for manufacturing components using an exposure apparatus constituting part of the substrate processing system. Prior Technology

[0002] In the lithography process for manufacturing micro-components such as semiconductor devices, multiple circuit patterns are stacked on a substrate such as a wafer or glass plate (hereinafter collectively referred to as a wafer). However, if the stacking accuracy between the layers is poor, the micro-component cannot perform its intended circuit characteristics and may become a defective product. Therefore, typically, marks (alignment marks) are pre-formed on multiple irradiation areas (shots) on the wafer. The position (coordinate value) of these marks on the stage coordinate system of the exposure apparatus is detected. Then, based on the position information of the marks and the known position information of the newly formed pattern (e.g., a tracing pattern), the wafer is aligned with the pattern by one irradiation area on the wafer.

[0003] As a wafer alignment method, Enhanced Global Alignment (EGA) has become the mainstream approach, based on the viewpoint of balancing output. It involves detecting alignment marks in only a few irradiated areas (also known as sampling irradiated areas or alignment irradiated areas) on the wafer and calculating the arrangement of the irradiated areas on the wafer using statistical methods.

[0004] However, in the lithography process, when performing overlay exposure on a wafer, the wafer, after undergoing processes such as resist coating, development, etching, CVD (chemical vapor deposition), and CMP (chemical mechanical polishing), may sometimes experience deformation in the arrangement of the irradiated areas of the previous layer due to these processes. This deformation can contribute to a decrease in overlay accuracy. In view of this, recent exposure apparatuses not only correct the primary composition of wafer deformation but also have lattice correction functions to correct nonlinear components such as the arrangement of irradiated areas caused by the process (see, for example, Patent Document 1).

[0005] However, with the miniaturization of integrated circuits, the requirements for stacking accuracy are becoming increasingly stringent. To achieve higher precision corrections, increasing the number of sampling irradiation areas—that is, increasing the number of marks to be detected—is indispensable. Furthermore, in a dual-stage exposure apparatus with two wafer-mounting stages, wafer exposure can be performed on one stage while mark detection on the other stage is performed in parallel. Therefore, the number of sampling irradiation areas can be increased without significantly reducing yield.

[0006] However, the requirements for overlay accuracy have become even more stringent. Even dual-stage exposure equipment cannot detect enough markers to achieve the required overlay accuracy without reducing output. Existing technical documents Patent documents

[0007] Patent Document 1: U.S. Application Publication No. 2002 / 0042664 Summary of the Invention

[0008] [Means for solving the problem] According to the first aspect, a measurement system is provided for a production line of micro-components, comprising: a plurality of measuring devices, each of which performs measurement processing on a substrate; and a control device capable of controlling the plurality of measuring devices, wherein the plurality of measuring devices includes at least one first measuring device that acquires position information of a plurality of marks formed on the substrate.

[0009] According to the second embodiment, a measurement system is provided for a micro-component production line, comprising: a first measuring device that acquires position information of a plurality of marks formed on a substrate; and a control device that controls the first measuring device, wherein the first measuring device acquires position information of the plurality of marks formed on a substrate subjected to exposure and development processes.

[0010] According to the third aspect, a measurement system is provided for a micro-component production line, comprising: a first measuring device that acquires position information of a plurality of marks formed on a substrate; and a control device that can control the first measuring device, wherein the first measuring device acquires position information of the plurality of marks formed on a substrate after etching and film deposition and before photosensitive material is coated.

[0011] According to the fourth aspect, a substrate processing system is provided, comprising: a measurement system of the third aspect; and an exposure apparatus having a substrate stage on which the substrate after the first measurement device included in the measurement system has completed measuring the position information of the plurality of marks is placed, and for the substrate placed on the substrate stage, alignment measurement is performed to acquire position information of a selected portion of the marks on the substrate, and the substrate is exposed using an energy beam.

[0012] According to the fifth aspect, a substrate processing system is provided, comprising: either the measurement system of the first aspect or the measurement system of the second aspect; and an exposure apparatus having a substrate stage on which the substrate after the first measurement device included in the measurement system has completed measuring the position information of the plurality of marks is placed, and for the substrate placed on the substrate stage, alignment measurement is performed to acquire position information of a selected portion of the marks on the substrate, and the substrate is exposed using an energy beam.

[0013] According to the sixth aspect, a method for manufacturing an element is provided, comprising: exposing a substrate using an exposure apparatus constituting a portion of either the substrate processing system of the fourth aspect or the substrate processing system of the fifth aspect; and developing the exposed substrate. Simple Explanation of the Diagram

[0014] [Figure 1] is a block diagram showing the substrate processing system of the first embodiment together with other devices used in the micro-component production line. [Figure 2] is a perspective view of the measurement system included in the substrate processing system of Figure 1. [Figure 3] is a top view of the measurement system in Figure 1 after the ceiling of the chamber has been removed. [Figure 4] is a three-dimensional diagram that schematically shows the composition of the measuring device that constitutes part of the measuring system. [Figure 5(A)] is a partial view of the measuring device in Figure 4 (viewed from the -Y direction), and [Figure 5(B)] is a partial cross-sectional view of the measuring device cut through the XZ plane of the optical axis AX1 of the mark detection system. [Figure 6] is an omitted cross-sectional view of a portion of the measuring device cut through the YZ plane of the optical axis AX1 of the mark detection system. [Figure 7(A)] is a perspective view of the reading head of the first position measurement system, and [Figure 7(B)] is a top view of the reading head of the first position measurement system (viewed from the +Z direction). [Figure 8] is a diagram illustrating the configuration of the second position measurement system. [Figure 9] is a block diagram showing the input / output relationship of the control device that mainly constitutes the control system of the measuring device. [Figure 10] is a flowchart corresponding to the processing algorithm of the control device when processing a batch of wafers. [Figure 11] is a schematic diagram showing the structure of the exposure apparatus shown in Figure 1. [Figure 12] is a block diagram showing the input / output relationship of the exposure control device in the exposure apparatus. [Figure 13(A)] is a diagram illustrating an example of higher-order partial differential correction, and [Figure 13(B)] is a diagram illustrating an example of first-order approximate correction. [Figure 14] is a schematic diagram showing the processing flow when the wafer lattice management method of the second embodiment, which uses a measuring device, is applied to the substrate processing system of Figure 1. [Figure 15] is a schematic diagram showing the processing flow when the stacking measurement method of the second embodiment using the measuring device is applied to the substrate processing system of Figure 1. [Figure 16] is a diagram illustrating one example of the manufacturing process of a semiconductor device. Implementation

[0015] First Implementation Form The first embodiment will be described below based on Figures 1 to 13(B). In Figure 1, the substrate processing system 1000 of the first embodiment for a micro-component (e.g., semiconductor component) production line is shown in a block diagram together with other devices for the production line.

[0016] As shown in Figure 1, the substrate processing system 1000 includes an exposure unit 200 and a coating and developing machine (resist coating and developing unit) 300 that are connected to each other in an online manner. Also, as shown in Figure 1, the substrate processing system 1000 includes a measurement system 500. Hereinafter, the coating and developing machine 300 will be referred to simply as C / D 300. Furthermore, the term "connected in an online manner" refers to the way different devices are connected to each other through the wafer (substrate) transport path. In this specification, the terms "connected in an online manner" or "online connection" are used in this sense. For example, when two different devices are connected online, a transport mechanism such as a robotic arm can be used to sequentially transport a wafer (substrate) processed in one device to the other device. Furthermore, the connection of different devices through an interface is also sometimes referred to as "online connection."

[0017] Here, the measurement system 500 includes three measuring devices 1001-1003 arranged adjacent to each other in a predetermined direction within the same chamber 502 (see Figure 2), and a measurement system control device 530 for unified management of the entire measurement system 500. Each measuring device 1001-1003 has a control device 60i (i=1-3), and each control device 60i is connected to the measurement system control device 530. Alternatively, the measurement system control device 530 may be used to control each of the measuring devices 1001-1003 without the control device 60i (i=1-3).

[0018] The exposure apparatus 200 and C / D 300 of the substrate processing system 1000 both have chambers, and the chambers are arranged adjacent to each other.

[0019] The exposure control device 220 of the exposure apparatus 200, the C / D control device 320 of the C / D apparatus 300, and the measurement system control device 530 are interconnected via a local area network (LAN) 1500. The LAN 1500 also connects to a host computer 2000 that manages the entire production line, an analysis device 3000, and a group of devices under the management of the host computer 2000 that perform various process processing (process processing before wafer fabrication). Figure 1 representatively shows film deposition devices 2300 such as the stack-up measuring instrument 400, etching device 2100, CMP device 2200, and CVD device within this group of devices. In addition, the LAN 1500 also connects to cleaning devices, oxidation / diffusion devices, and ion implantation devices.

[0020] Furthermore, the substrate processing system 1000 may also include at least one of the following: host computer 2000, analysis device 3000, stacking measuring device 400, etching device 2100, CMP device 2200, and film forming device 2300.

[0021] First, the measurement system 500 will be described. Figure 2 shows a perspective view of the measurement system 500. The measurement system 500 is separately installed on the floor F of the cleanroom from other devices constituting the substrate processing system 1000. That is, the measurement system 500 is not connected to the exposure apparatus 200 and the C / D converter 300.

[0022] The measurement system 500 includes: a chamber 502 in which the aforementioned three measuring devices 1001-1003 are disposed; and a carrier system 510 disposed on one side of the chamber 502. In this embodiment, the carrier system 510 is an EFEM (Equipment Front End Module) system. Hereinafter, the carrier system 510 may also be referred to as the EFEM system 510.

[0023] Furthermore, as described later, the carrier system 510 of this embodiment is for use with FOUP (Front-Opening Unified Pod), but is not limited to FOUP. Other types of carriers (such as SMIF pods) that can accommodate one or more wafers can also be processed using the carrier system 510.

[0024] The following explanation will be based on the following: the arrangement direction of chamber 502 and EFEM system 510 is the X-axis direction, the direction perpendicular to the X-axis in the plane parallel to the ground F is the Y-axis direction, and the direction orthogonal to the X-axis and Y-axis is the Z-axis direction.

[0025] As shown in Figure 2, chamber 502 has a cuboid shape. Within its first space, as shown in Figure 3, measuring devices 1001-1003 are arranged along the X-axis. Figure 3 shows a top view of the measuring system 500 with the ceiling portion of chamber 502 removed. In Figure 3, the chambers 101i (i=1-3) of each measuring device 1001-1003 are shown. Alternatively, measuring devices 1001-1003 may not each have a chamber 101i.

[0026] In the measurement system 500, since a plurality of measuring devices 1001-1003 are arranged along the X-axis, the width of the measurement system 500 in the Y-axis direction can be increased without increasing the width of the measuring devices 1001-1003. In the factory where the measurement system 500 is installed, the operator's passage extends along the Y-axis, and the devices for performing the aforementioned processes (etching device 2100, CMP device 2200, etc.) are arranged along this passage. Therefore, in order to effectively utilize the factory floor space F, it is crucial to minimize the width of the measurement system 500 in the Y-axis direction.

[0027] Furthermore, a transport system 521 is configured on the -Y side of the first space within chamber 502. This transport system 521 can transport wafers together with the measuring devices 1001-1003. For convenience, the space on the -Y side of the first space where the transport system 521 is located will be referred to as the second space. In Figure 2, the thick dashed line represents the imaginary separation between the first space and the second space.

[0028] An EFEM system 510 is installed on the ground F adjacent to the -X side (front surface side) of chamber 502. The EFEM system 510 is a module machine comprising an EFEM body 512 and load ports. The EFEM body 512 houses a wafer handling robot, and the load ports are mounted on the -X side (front surface side) of the EFEM body 512. On the EFEM body 512, a plurality of load ports 514 (also referred to as carrier mounting devices) for FOUP are arranged along the Y-axis direction on its front surface side. Furthermore, in this embodiment, the EFEM body 512 has three load ports 514, but the number of load ports is not limited to three; it can also be one, two, four, or more. Here, FOUP refers to a wafer transport and storage rack used in semiconductor factories with a mini-environment as specified in SEMI standard E47.1, designed for the purpose of transporting and storing wafers. It is a front-opening integrated box-type transport and storage box. In Figures 2 and 3, FOUP 520 is provided on each of the three load ports 514. At least one wafer is contained in the FOUP as the object of measurement.

[0029] In this embodiment, although the illustration is omitted, an OHT (Overhead Hoist Transport) rail is provided near the ceiling of the cleanroom directly above the three load ports 514. An OHT is an unmanned transport vehicle that moves in space at the ceiling level. By means of the OHT, FOUP 520 is moved onto the load port 514.

[0030] Each of the three load ports 514 has a mounting portion 515 and an opening / closing mechanism 518 for opening and closing the cover of the FOUP 520 mounted on the mounting portion 515. The opening / closing mechanism 518 is provided on the front side of the EFEM body 512, opposite to the FOUP 520 mounted on the mounting portion 515 of the load port 514, and can open and close the cover of the FOUP 520 while maintaining an airtight state between the inside and outside of the FOUP 520. This type of opening / closing mechanism is well known, so the description of the structure of the opening / closing mechanism 518 is omitted.

[0031] Inside the EFEM body 512, there are three wafer transport robots 516 (see Figure 3) that can enter and exit the FOUP (Fan Filter Unit) in an open state to retrieve / place wafers. Furthermore, an FFU (Fan Filter Unit, not shown) can be installed on the upper part of the EFEM body 512 to maintain the cleanliness inside the EFEM body 512, through which temperature-controlled air from an air conditioner is delivered to the interior of the EFEM body 512. Additionally, a buffer section can be installed inside the EFEM body 512 to stabilize the temperature of the wafers using temperature-controlled air from an air conditioner.

[0032] An opening is formed on the back side of the EFEM body 512 opposite to the second space of the chamber 502, and the opening is opened and closed by an opening and closing member.

[0033] The components of the EFEM system 510 (robot 516, opening and closing mechanism 518, etc.) are controlled by the measurement system control device 530 (see Figure 1).

[0034] As shown in Figure 3, a conveying system 521 is provided inside the second space of chamber 502. It includes: guide rails 522A and 522B, respectively disposed on one side and the other side of the Y-axis in the second space, extending along the X-axis direction and covering approximately the entire length of chamber 502; a load-carrying conveying member 524, which can reciprocate along guide rail 522A; and an unloading conveying member 526, which can reciprocate along guide rail 522B.

[0035] The load-carrying conveying member 524 can move along the guide rail 522A by means of a linear motor (using the same symbol as the guide rail with the built-in fixed member, denoted as linear motor 522A) having a fixed member built into the guide rail 522A and a movable member provided in the conveying member 524. Similarly, the unloading conveying member 526 can move along the guide rail 522B by means of a linear motor (using the same symbol as the guide rail with the built-in fixed member, denoted as linear motor 522B) having a fixed member built into the guide rail 522B and a movable member provided in the conveying member 526. The linear motors 522A and 522B are controlled by the measurement system control device 530. Furthermore, the conveying members 524 and 526 can also move non-contactly using pneumatic sliders or the like. Furthermore, the drive mechanism for driving the conveying components 524 and 526 is not limited to the aforementioned linear motors (522A and 522B), but can also be a combination of a rotary motor and a ball screw mechanism.

[0036] Guide rail 522A is positioned higher than guide rail 522B. Therefore, the load-carrying member 524 moves in space above the unloading member 526.

[0037] Furthermore, in the aforementioned conveying system 521, the conveying component 524 and the guide rail 522A can also be used for loading and unloading the wafer, and the conveying component 526 and the guide rail 522B can be used for loading and unloading the wafer.

[0038] Furthermore, the aforementioned transport system 521 can transport wafers separately with a plurality of measuring devices 1001-1003. However, the transport system 521 may also have a transport device (including guide rails and transport components) that transports wafers only with measuring device 1001, a transport device (including guide rails and transport components) that transports wafers only with measuring device 1002, and a transport device (including guide rails and transport components) that transports wafers only with measuring device 1003. In this case, the transport device may have guide rails and transport components for loading and guide rails and transport components for unloading, or it may have guide rails and transport components that can be used for both loading and unloading.

[0039] As shown in Figure 3, a wafer transport system 70i (i=1~3) is provided in the measuring device 100i. The wafer transport system 70i (i=1~3) is a multi-joint robot that transports wafers between transport members 524 and 526. The wafer transport system 70i (i=1~3) transports wafers between transport members 524 and 526 through the opening of the chamber 101i.

[0040] The transport member 524 is located at a wafer transport position (load-side wafer transport position) near the boundary between the EFEM body 512 and the chamber 502. It picks up the wafer, which is the object of measurement processing, from the robot 516 and transports it to the wafer transport position of the wafer transport system 70i (i=1 to 3) and the measurement device 100i. In this embodiment, the wafer that is the object of measurement processing is a wafer whose necessary processing in the process steps before wafer fabrication, such as etching, oxidation / diffusion, film deposition, ion implantation, and planarization (CMP), has been completed after at least the first layer of exposure and development. It is also a wafer that has been transported to the C / D 300 stage for the purpose of coating resist.

[0041] The conveying component 526 picks up the wafer that has been measured from the wafer conveying system 70i (i=1 to 3) and conveys it to the unloading side wafer conveying position (the position below the aforementioned load side wafer conveying position) set near the boundary between the EFEM body 512 and the chamber 502.

[0042] Robot 516 will transport the completed measurement wafers, which have been transported to the wafer transport position on the unloading side by the transport component 526, into (return to) FOUP 520.

[0043] Returning to Figure 1, each of the measuring devices 1001 to 1003 in this embodiment uses a measuring device with the same configuration.

[0044] Furthermore, in this embodiment, the following situation is illustrated: the conveying system 521, such as the conveying member 524 and the conveying member 526, for transporting wafers with the measuring device 100i is arranged in the second space of the chamber 502. In this way, the space in which the wafers are transported by the conveying member 524 and the conveying member 526 ultimately becomes an airtight space. However, it is not limited to this. Alternatively, the three measuring devices 1001 to 1003 can be arranged on the ground F, and other chambers containing the conveying system 521 can be set up inside the measuring devices 1001 to 1003 (whether or not they are housed in the same chamber).

[0045] Alternatively, a multi-joint robot capable of reciprocating along a guide rail can be used instead of the conveying components 524 and 526. In this case, the wafer conveying system 70i may not need to have a multi-joint robot; it only needs to have a load wafer holding part and an unloading wafer holding part for wafer transport with the multi-joint robot of the conveying system 521.

[0046] Furthermore, when a multi-joint robot is used instead of the conveying components 524 and 526, the EFEM system 510 may not need to have robot 516. In this case, the multi-joint robot of the conveying system 521 can also remove the wafer from FOUP 520 or return the wafer to FOUP 520.

[0047] Here, the measuring device 100i will be described in detail. Figure 4 shows a perspective view of the structure of the measuring device 100i. Furthermore, the measuring device 100i shown in Figure 4 actually includes the aforementioned chamber 101i and the components housed within that chamber 101i, but descriptions related to the chamber 101i are omitted below. In this embodiment of the measuring device 100i, a mark detection system MDS is provided as described later. Hereinafter, the direction of the optical axis AX1 of the mark detection system MDS is aligned with the aforementioned Z-axis direction, and in the XY plane orthogonal to it, the direction of long-stroke movement of the movable stage (described later) is aligned with the aforementioned Y-axis direction. The directions of rotation (tilt) around the X-axis, Y-axis, and Z-axis are described as θx, θy, and θz, respectively. Here, the mark detection system MDS has a cylindrical lens section 41 at its lower end (front end). Inside the lens section 41, an optical system (refractive optical system) is housed. This optical system (refractive optical system) includes a plurality of lens elements having a common optical axis AX1 in the Z-axis direction. In this specification, for ease of explanation, the optical axis AX1 of the refractive optical system inside the lens section 41 is referred to as the optical axis AX1 of the mark detection system MDS.

[0048] Figure 5(A) shows a partially omitted front view of the measuring device 100i in Figure 4 (viewed from the -Y direction). Figure 5(B) shows a partially omitted cross-sectional view of the measuring device 100i cut along the XZ plane of the optical axis AX1. Figure 6 also shows a partially omitted cross-sectional view of the measuring device 100i cut along the YZ plane of the optical axis AX1.

[0049] As shown in Figure 4, the measuring device 100i includes: a fixed disk 12 having an upper surface that is approximately parallel to the XY plane orthogonal to the optical axis AX1; a wafer slider (hereinafter referred to as slider) 10 disposed on the fixed disk 12, holding the wafer W and movable relative to the fixed disk 12 along the X and Y axes with a predetermined stroke, and capable of minute movement (micro-displacement) in the Z, θx, θy, and θz directions; a drive system 20 (see Figure 9) that drives the slider 10; and a first position measuring system 30 (not shown in Figure 4, see Figures 6 and 9) that controls the slider 10 relative to the fixed disk 12 in each of the X, Y, Z, θx, θy, and θz directions (hereinafter referred to as the 6 degrees of freedom directions). The measurement unit 40 has a mark detection system MDS that detects marks mounted (held) on the wafer W of the slider 10; a second position measurement system 50 (see Figure 9) that measures the relative position information between the mark detection system MDS (measurement unit 40) and the fixed plate 12; and a control device 60i (not shown in Figure 4, see Figure 9) that controls the drive system 20 to drive the slider 10, acquires the measurement information of the first position measurement system 30 and the second position measurement system 50, and uses the mark detection system MDS to determine the position information of a plurality of marks held on the wafer W of the slider 10.

[0050] The fixed plate 12 is composed of a cuboid component that is rectangular (or square) when viewed from above. Its upper surface is finished in a way that makes it extremely flat, forming the guide surface for the movement of the slider 10. The fixed plate 12 is made of a low thermal expansion material, also known as a zero expansion material, such as steel alloy, extremely low expansion cast steel, or extremely low expansion glass ceramic.

[0051] On the fixed plate 12, there are three cavities 12a with bottom openings, one at the center of the X-axis direction on the -Y side and one at each end of the X-axis direction on the +Y side. Figure 4 shows the cavity 12a formed on the -Y side. A vibration damping device 14 is disposed inside each cavity 12a. The fixed plate 12 is supported at three points on the upper surface of the rectangular base frame 16, which is parallel to the XY plane, provided by the three vibration damping devices 14, with the upper surface approximately parallel to the XY plane. Furthermore, the number of vibration damping devices 14 is not limited to three.

[0052] As shown in Figure 6, the slider 10 has four air hydrostatic bearings (air bearings) 18, one at each of the four corners of its bottom surface, installed with their bearing surfaces approximately flush with the lower surface of the slider 10. The slider 10 is suspended and supported by the static pressure (pressure within the gap) between the bearing surfaces of the pressurized air ejected from the four air bearings towards the fixed plate 12 and the upper surface (guide rail surface) of the fixed plate 12. This is achieved through a predetermined clearance (gap, gap), for example, a clearance of approximately several μm, on the upper surface of the fixed plate 12. In this embodiment, the slider 10 is made of zero-expansion glass (e.g., Schott's Zerodur), a material known as a zero-expansion material.

[0053] A recess 10a of predetermined depth, slightly larger than the inner diameter of the wafer W, is formed on the upper part of the slider 10. Inside the recess 10a, a wafer holder WH with a diameter approximately the same as that of the wafer W is disposed. The wafer holder WH can be a vacuum clamp, an electrostatic clamp, or a mechanical clamp; for example, a pin-clamping vacuum clamp is used. The wafer W is held by the wafer holder WH with its upper surface approximately flush with the upper surface of the slider 10. A plurality of suction ports are formed on the wafer holder WH, which are connected to a vacuum pump 11 (see Figure 9) via a vacuum piping system (not shown). The vacuum pump 11 is controlled by a control device 60i. Furthermore, either or both of the slider 10 and the wafer holder WH can be referred to as the "first substrate holding member".

[0054] Furthermore, a vertically moving member (not shown) is provided on the slider 10. This vertically moving member moves up and down through, for example, three circular openings formed on the wafer holder WH, and cooperates with the wafer transport system 70i (not shown in FIG. 4, see FIG. 9) to load the wafer onto the wafer holder WH and unload the wafer from the wafer holder WH. The drive device 13 that drives the vertically moving member is controlled by the control device 60i (see FIG. 9).

[0055] In this embodiment, one example of a wafer holder WH is a 300 mm wafer capable of holding a 300 mm diameter wafer. Furthermore, when the wafer transport system 70i has a non-contact holding member, such as a Bernoulli clamp, that non-contactly attracts and holds the wafer on the wafer holder WH from above, it is not necessary to provide a vertical movement member on the slide 10, nor is it necessary to form a circular opening on the wafer holder WH for the vertical movement member.

[0056] As shown in Figures 5(B) and 6, a 2D grating (hereinafter referred to as the grating) RG1 is horizontally (parallel to the surface of the wafer W) arranged in an area slightly larger than the wafer W on the lower surface of the slider 10. The grating RG1 includes: a reflective diffraction lattice (X-diffraction lattice) with the X-axis direction set as the periodic direction; and a reflective diffraction lattice (Y-diffraction lattice) with the Y-axis direction set as the periodic direction. The spacing between the lattice lines of the X-diffraction lattice and the Y-diffraction lattice is set to, for example, 1 μm.

[0057] The vibration damping device 14 is an active vibration isolation system (AVIS), which includes an accelerometer, a displacement sensor (such as an electrostatic capacitance sensor), an actuator (such as a voice coil motor), and an air damper that functions as an air damper. The vibration damping device 14 can attenuate relatively high-frequency vibrations through the air damper and can also dampen vibrations through the actuator. Therefore, the vibration damping device 14 can prevent vibration from being transmitted between the fixed plate 12 and the base frame 16. Alternatively, a hydraulic damper can be used instead of an air damper.

[0058] The reason for including an actuator in addition to the air damper is that the air pressure inside the air damper's chamber is high, and the control response can only be ensured at around 20 Hz. Therefore, in situations requiring high-response control, the actuator must be controlled based on the output of an accelerometer (not shown). However, micro-vibrations such as floor vibrations can be damped by the air damper.

[0059] The upper end face of the vibration damping device 14 is connected to the fixed plate 12. For the air damper, gas (e.g., compressed air) can be supplied through a gas supply port (not shown). The air damper extends and retracts in the Z-axis direction with a predetermined stroke (e.g., about 1 mm) corresponding to the amount of gas filled into it (pressure change of the compressed air). Therefore, by using the air dampers of each of the three vibration damping devices 14, the three points of the fixed plate 12 can be moved up and down individually from below, thereby allowing arbitrary adjustment of the positions of the fixed plate 12 and the slider 10 suspended on it in the Z-axis direction, θx direction, and θy direction. Furthermore, the actuator of the vibration damping device 14 can drive the fixed plate 12 not only in the Z-axis direction, but also in the X-axis and Y-axis directions. Moreover, the driving amount in the X-axis and Y-axis directions is smaller than the driving amount in the Z-axis direction. The three vibration damping devices 14 are connected to the control device 60i (see Figure 9). Furthermore, the three vibration damping devices 14 are not limited to the X-axis, Y-axis, and Z-axis directions; for example, they may also include actuators that allow the fixed plate 12 to move in six degrees of freedom. Based on the relative position information between the mark detection system MDS (measuring unit 40) and the fixed plate 12 measured by the second position measurement system 50, the control device 60i continuously and in real-time controls the actuators of the three vibration damping devices 14 to maintain the desired positional relationship between the fixed plate 12, to which the reading head 32 of the first position measurement system 30 is fixed, and the mark detection system MDS. Furthermore, each of the three vibration damping devices 14 can also be fed forward controlled. For example, the control device 60i can also perform feedforward control on each of the three vibration damping devices 14 based on the measurement information from the first position measurement system 30. Furthermore, the control of the vibration damping devices 14 by the control device 60i will be further described later.

[0060] As shown in FIG9, the drive system 20 includes a first drive device 20A that drives the slider 10 along the X-axis direction, and a second drive device 20B that is integral with the first drive device 20A and drives the slider 10 along the Y-axis direction.

[0061] As shown in Figures 4 and 6, on the -Y side of the slider 10, a pair of movable members 22a are fixed at predetermined intervals along the X-axis. These movable members 22a are composed of magnet units (or coil units) and are shaped like an inverted L when viewed from the side. On the +Y side of the slider 10, as shown in Figure 6, a pair of movable members 22b (but the movable members 22b on the +X side are not shown) are fixed at predetermined intervals along the X-axis. The pair of movable members 22a and the pair of movable members 22b are arranged symmetrically from left to right, but are constructed identically to each other.

[0062] As shown in Figures 4-6, movable members 22a and 22b are supported non-contactly on the upper surfaces of a pair of plate members 24a and 24b, which are substantially parallel to the XY plane. These plate members 24a and 24b form part of a rectangular movable platform 24 in plan view and are arranged at a predetermined distance along the Y-axis, extending along the X-axis. Specifically, air bearings (not shown) are provided on the lower surfaces of movable members 22a and 22b (the surfaces facing the plate members 24a and 24b respectively). The movable members 22a and 22b are supported non-contactly from below by the movable platform 24 through the levitation force (static pressure of pressurized air) generated by these air bearings relative to the plate members 24a and 24b. Furthermore, the weight of the slider 10, to which each pair of movable members 22a and 22b is fixed, is supported by the levitation force generated by the four air bearings 18 relative to the fixed plate 12, as described above.

[0063] As shown in Figures 4 to 6, on the upper surface of each of the pair of plate members 24a and 24b, fasteners 26a and 26b composed of coil units (or magnet units) are arranged in the region at both ends except in the X-axis direction.

[0064] The electromagnetic interaction between a pair of movable members 22a and fixed members 26a generates a driving force (electromagnetic force) that drives the pair of movable members 22a along the X-axis and along the Y-axis. Similarly, the electromagnetic interaction between a pair of movable members 22b and fixed members 26b generates a driving force (electromagnetic force) that drives the pair of movable members 22b along the X-axis and along the Y-axis. In other words, the pair of movable members 22a and fixed members 26a constitute an XY linear motor 28A that generates driving forces in the X-axis and Y-axis directions; the pair of movable members 22b and fixed members 26b constitute an XY linear motor 28B that generates driving forces in the X-axis and Y-axis directions; and the XY linear motors 28A and 28B constitute a first drive device 20A that drives the slider 10 along the X-axis for a predetermined stroke and performs minute driving along the Y-axis (see Figure 9). The first drive device 20A drives the slider 10 along the θz direction by making the driving forces generated by the XY linear motors 28A and 28B in the X-axis direction different in magnitude. The first drive device 20A is controlled by the control device 60i (see Figure 9). In this embodiment, the first drive device 20A and the second drive device described later together constitute a coarse and fine motion drive system for driving the slider 10 in the Y-axis direction. Based on this relationship, the first drive device 20A generates driving force not only in the X-axis direction but also in the Y-axis direction, but the first drive device 20A may not necessarily need to generate driving force in the Y-axis direction.

[0065] The movable platform 24 has a pair of plate members 24a and 24b and a pair of connecting structural members 24c and 24d arranged at a predetermined distance along the X-axis and extending along the Y-axis respectively. Stepped portions are formed at both ends of the connecting structural members 24c and 24d in the Y-axis direction. Furthermore, when one end of the plate member 24a along its length is placed on the stepped portions on the -Y side of each of the connecting structural members 24c and 24d, the connecting structural members 24c and 24d are integrated with the plate member 24a. Similarly, when one end of the plate member 24b along its length is placed on the stepped portions on the +Y side of each of the connecting structural members 24c and 24d, the connecting structural members 24c and 24d are integrated with the plate member 24b (see Figure 5(B)). In this way, the pair of plate members 24a and 24b are connected by the pair of connecting structural members 24c and 24d, forming a rectangular frame-shaped movable platform 24.

[0066] As shown in Figures 4 and 5(A), a pair of linear guides 27a and 27b extending along the Y-axis are fixed near both ends of the upper surface of the base frame 16 in the X-axis direction. Inside one of the linear guides 27a on the +X side, near the upper surface and the -X side surface, a fixing member 25a (see Figure 5(B)) for a Y-axis linear motor 29A, which is composed of coil units (or magnet units) and covers approximately the entire length of the Y-axis, is housed. A movable member 23a, composed of L-shaped magnet units (or coil units), is arranged facing the upper surface and the -X side surface of the linear guide 27a and together with the fixing member 25a constitutes the Y-axis linear motor 29A. Air bearings for ejecting pressurized air from opposing surfaces are fixed on the lower surface and the +X side surface of the movable member 23a, respectively, facing the upper surface and the -X side surface of the linear guide 27a. In particular, the air bearing fixed to the +X side of the movable member 23a is a vacuum preload type air bearing. This vacuum preload type air bearing maintains the clearance (gap, void) in the X-axis direction between the movable member 23a and the linear guide 27a at a fixed value by balancing the static pressure of the pressurized air between the bearing surface and the -X side of the linear guide 27a with the vacuum preload pressure.

[0067] On the upper surface of the movable member 23a, X-rails 19, composed of a plurality of, for example, two cuboid members, are fixed at predetermined intervals along the Y-axis. Sliding members 21 with an inverted U-shaped cross-section are non-contactly engaged on each of the two X-rails 19. These sliding members 21, together with the X-rails 19, constitute a single-axis guide rail device. Air bearings are provided on the three faces of the sliding members 21 facing the X-rails 19.

[0068] As shown in Figure 4, the two sliding components 21 are fixed to the lower surface (-Z side) of the connecting component 24c.

[0069] Another linear guide 27b located on the -X side houses a fixing member 25b for a Y-axis linear motor 29B composed of coil units (or magnet units), which is symmetrical to the linear guide 27a but has the same configuration (see Figure 5(B)). A movable member 23b is arranged facing the upper surface and the +X side of the linear guide 27b. This movable member 23b is symmetrical to the movable member 23a but is composed of magnet units (or coil units) with the same L-shaped cross-section, and together with the fixing member 25b, it constitutes the Y-axis linear motor 29B. Air bearings are fixed to the lower surface and the -X side of the movable member 23b, respectively, facing the upper surface and the +X side of the linear guide 27b. In particular, the air bearing fixed to the -X side of the movable member 23b is a vacuum preload type air bearing. The vacuum preloaded air bearing maintains the clearance (gap, void) in the X-axis direction between the movable part 23b and the linear guide 27b at a fixed value.

[0070] Between the upper surface of the movable member 23b and the bottom surface of the connecting member 24d, as described above, two single-axis guide rail devices are provided. Each single-axis guide rail device consists of an X-guide rail 19 and a sliding member 21 that is non-contactly engaged with the X-guide rail 19.

[0071] The movable platform 24 is supported from below by movable members 23a and 23b via two single-axis guide rails on the +X side and two on the -X side (a total of four), allowing it to move along the X-axis on the movable members 23a and 23b. Therefore, when the slider 10 is driven along the X-axis by the aforementioned first drive device 20A, the reaction force of this drive force acts on the movable platform 24, which is equipped with fixed members 26a and 26b, causing the movable platform 24 to move in the opposite direction to the slider 10 according to the law of conservation of momentum. That is, by moving the movable platform 24, vibrations caused by the reaction force of the drive force on the slider 10 in the X-axis direction are prevented (or effectively suppressed). In other words, the movable platform 24 functions as a balancing mass during the movement of the slider 10 in the X-axis direction. However, it is not necessarily necessary for the movable platform 24 to function as a balancing mass. Furthermore, since the slider 10 moves only slightly along the Y-axis relative to the movable platform 24, there is no need to specially set a balancing mass. However, a balancing mass can be set to prevent (or effectively suppress) the vibration caused by the driving force that drives the slider 10 along the Y-axis relative to the movable platform 24.

[0072] Y-axis linear motor 29A generates a driving force (electromagnetic force) to drive movable member 23a along the Y-axis direction through electromagnetic interaction between movable member 23a and fixed member 25a. Y-axis linear motor 29B generates a driving force (electromagnetic force) to drive movable member 23b along the Y-axis direction through electromagnetic interaction between movable member 23b and fixed member 25b.

[0073] The driving force in the Y-axis direction generated by the Y-axis linear motors 29A and 29B acts on the movable stage 24 through two single-axis guide rail devices on the +X and -X sides. Thus, the slider 10 and the movable stage 24 are driven integrally along the Y-axis direction. That is, in this embodiment, the movable stage 24, the four single-axis guide rail devices, and the pair of Y-axis linear motors 29A and 29B constitute the second driving device 20B for driving the slider 10 along the Y-axis direction (see Figure 9).

[0074] In this embodiment, the pair of Y-axis linear motors 29A and 29B are physically separated from the fixed plate 12, and are also separated from vibration by the three vibration damping devices 14. Furthermore, the linear guides 27a and 27b, which are respectively equipped with the fixing members 25a and 25b of the pair of Y-axis linear motors 29A and 29B, can be configured to move relative to the base frame 16 in the Y-axis direction, thereby functioning as a balancing mass when the slider 10 is driven in the Y-axis direction.

[0075] As shown in FIG4, the measuring unit 40 has: a unit body 42, which has a cut-out cavity 42a with a bottom opening on the -Y side surface; the aforementioned mark detection system MDS, which is connected to the unit body 42 with its base end inserted into the cavity 42a; and a connecting mechanism 43, which connects the lens barrel portion 41 of the front end of the mark detection system MDS to the unit body 42.

[0076] The connecting mechanism 43 includes: a support plate 44 that supports the lens barrel 41 on the rear side (+Y side) via a mounting member not shown; and a pair of support arms 45a, 45b, each having one end supporting the support plate 44 and the other end fixed to the bottom surface of the unit body 42.

[0077] In this embodiment, a resist is coated on the upper surface of the wafer held on the slider 10. Correspondingly, the mark detection system MDS uses a detection beam with a wavelength that does not expose the resist to light. The mark detection system MDS may employ an image processing-based FIA (Field Image Alignment) system, where a broadband detection beam that does not expose the resist coated on the wafer is irradiated onto the target mark. An imaging element (CCD, etc.) is used to capture an image of the target mark and an image of an indicator (not shown, an indicator pattern on an internal indicator plate) formed on the illuminated surface by the reflected light from the target mark, and the image signals are output. The image signals from the mark detection system MDS are supplied to the control device 60i (see Figure 9) via a signal processing device 49 (not shown in Figure 4, see Figure 9). The mark detection system MDS has an autofocus function that adjusts the focus position of the optical system.

[0078] As shown in FIG. 4, a readhead mounting member 51 with a generally equilateral triangle shape is disposed between the lens barrel portion 41 and the support plate 44. An opening penetrating the Y-axis direction of FIG. 4 is formed in the readhead mounting member 51, and the lens barrel portion 41 is mounted (fixed) to the support plate 44 through a mounting member (not shown) inserted into this opening. Furthermore, the back side of the readhead mounting member 51 is also fixed to the support plate 44. Thus, the lens barrel portion 41 (marker detection system MDS), the readhead mounting member 51, and the support plate 44 are integrated with the unit body 42 through a pair of support arms 45a and 45b.

[0079] Inside the unit body 42, the aforementioned signal processing device 49 is disposed. This signal processing device 49 processes the camera signal output by the self-marking detection system MDS as a detection signal, calculates the position information of the object mark relative to the detection center, and outputs it to the control device 60i. The unit body 42 is mounted on a support frame 46 that is shaped like a gate when viewed from the Y-side, and is supported at three points below by a plurality of, for example, three vibration damping devices 48. Each vibration damping device 48 is an active vibration isolation system (AVIS), which includes an accelerometer, a displacement sensor (such as an electrostatic capacitance sensor), an actuator (such as a voice coil motor), and mechanical dampers such as air dampers or hydraulic dampers. The vibration damping device 48 can attenuate relatively high-frequency vibrations by means of mechanical dampers, and can perform vibration damping by means of actuators. Therefore, each vibration damping device 48 can prevent relatively high frequency vibrations from being transmitted between the support frame 46 and the unit body 42.

[0080] Furthermore, the marker detection system MDS is not limited to the FIA ​​system. For example, a diffraction interferometry alignment detection system can be used instead of the FIA ​​system. This system illuminates the object mark with coherent detection light, causing two diffracted beams (e.g., diffracted beams of the same number of times, or diffracted beams diffracting in the same direction) generated from the object mark to interfere and be detected, and a detection signal is output. Alternatively, a diffraction interferometry alignment system can be used in conjunction with an FIA system to detect two object marks simultaneously. Furthermore, a beam scanning alignment system can also be used as the marker detection system MDS. This system scans the object mark along a predetermined direction with a measuring light while the slider 10 is moved in that direction. In this embodiment, the marker detection system MDS has an autofocus function, but the measurement unit 40 can also be equipped with a focal point position detection system, such as a multi-point focal point position detection system with the same oblique incidence configuration as disclosed in U.S. Patent No. 5,448,332.

[0081] The first position measurement system 30, as shown in Figures 5(B) and 6, has a read head 32, which is disposed within a recess formed on the upper surface of the fixed plate 12 and fixed to the fixed plate 12. The upper surface of the read head 32 faces the lower surface of the slider 10 (the forming surface of the grating RG1). A predetermined clearance (gap, void) of approximately several millimeters is formed between the upper surface of the read head 32 and the lower surface of the slider 10.

[0082] The first position measurement system 30, as shown in Figure 9, includes an encoder system 33 and a laser interferometer system 35. The encoder system 33 illuminates a plurality of light beams onto the measuring section (forming surface of the grating RG1) on the lower surface of the slider 10 via a readhead 32, and receives a plurality of returned light beams (e.g., a plurality of diffracted light beams from the grating RG1) from the measuring section on the lower surface of the slider 10 to obtain position information of the slider 10. The encoder system 33 includes an X-linear encoder 33x for measuring the position of the slider 10 in the X-axis direction, and a pair of Y-linear encoders 33ya and 33yb for measuring the position of the slider 10 in the Y-axis direction. The encoder system 33 may use, for example, a diffracted interferometer type readhead with the same configuration as those disclosed in U.S. Patent No. 7,238,931 and U.S. Patent Application Publication No. 2007 / 288,121 (hereinafter appropriately referred to as the readhead). Furthermore, the read head includes a light source and a light receiving system (including a detector), as well as an optical system. However, in this embodiment, as long as at least one of the optical systems is disposed inside the frame of the read head 32 facing the grating RG1, at least one of the light source and the light receiving system can also be disposed outside the frame of the read head 32.

[0083] Figure 7(A) shows a perspective view of the read head 32, and Figure 7(B) shows a top view of the upper surface of the read head 32 viewed from the +Z direction. The encoder system 33 uses one X read head 37x to measure the position of the slider 10 in the X-axis direction and a pair of Y read heads 37ya and 37yb to measure the position in the Y-axis direction (see Figure 7(B)). That is, the X read head 37x, which uses the X diffraction grid of the grating RG1 to measure the position of the slider 10 in the X-axis direction, constitutes the aforementioned X linear encoder 33x, and the pair of Y read heads 37ya and 37yb, which use the Y diffraction grid of the grating RG1 to measure the position of the slider 10 in the Y-axis direction, constitute a pair of Y linear encoders 33ya and 33yb.

[0084] As shown in Figures 7(A) and 7(B), the X-reader 37x is positioned at two equidistant points (see the white circles in Figure 7(B)) on a straight line LX passing through the center of the reader 32 and parallel to the X-axis, and a straight line CL passing through the center of the reader 32 and parallel to the Y-axis. Measurement beams LBx1 and LBx2 (shown as solid lines in Figure 7(A)) are then projected onto the same illumination point on the grating RG1. For the illumination points of the measurement beams LBx1 and LBx2, which are also the detection points of the X-reader 37x (see the symbol DP in Figure 7(B)), their positions in the X-axis and Y-axis directions are consistent with the detection center of the mark detection system MDS.

[0085] Here, the measurement beams LBx1 and LBx2 are beams from the light source that are polarized and separated by a polarizing beam splitter (not shown). When the measurement beams LBx1 and LBx2 illuminate the grating RG1, the measurement beams LBx1 and LBx2, after being diffracted a predetermined number of times by the X-ray diffraction lattice (e.g., the first diffracted beam), pass through a lens (not shown), a quarter-wave plate (not shown), and are reflected back by a mirror, and then pass through the quarter-wave plate twice. In this way, the polarization direction is rotated by 90 degrees, and the beams are re-intruded into the polarizing beam splitter through the original optical path and combined into a coaxial beam. The interference light between the first diffracted beams of measurement beams LBx1 and LBx2 is received by an optical detector (not shown), thereby measuring the position of the slider 10 in the X-axis direction.

[0086] As shown in Figure 7(B), a pair of Y-readers 37ya and 37yb are respectively positioned on the +X and -X sides of the straight line CL. As shown in Figures 7(A) and 7(B), the Y-reader 37ya is located at a common illumination point on the grating RG1, where the measurement beams LBya1 and LBya2 (shown as dashed lines in Figure 7(A)) are equidistant from two points on the straight line LYa at a distance from the straight line LX (refer to the white circles in Figure 7(B)). The illumination point of the measurement beams LBya1 and LBya2, which is also the detection point of the Y-reader 37ya, is indicated by the symbol DPya in Figure 7(B).

[0087] The Y-reader 37yb is located at two points symmetrical about the line CL and the emission points of the measurement beams LBya1 and LBya2 of the Y-reader 37ya (see the white circle in Figure 7(B)). The measurement beams LByb1 and LByb2 are directed to a common illumination point DPyb on the grating RG1. As shown in Figure 7(B), the detection points DPya and DPyb of the Y-readers 37ya and 37yb are arranged on the line LX parallel to the X-axis.

[0088] The measurement beams LBya1 and LBya2 are also separated from the same beam by a polarizing beam splitter. These measurement beams LBya1 and LBya2, after passing through a Y-diffraction lattice, become beams of a predetermined order of diffraction, such as the second diffraction beam. The interference of these beams is then photoelectrically detected by an detector (not shown), thereby measuring the position of the slider 10 in the Y-axis direction. Similarly, for the measurement beams LByb1 and LByb2, the interference of these beams is photoelectrically detected by an detector (not shown), thereby measuring the position of the slider 10 in the Y-axis direction.

[0089] Here, the control device 60i determines the position of the slider 10 in the Y-axis direction based on the average of the measurements from the two Y-reading heads 37ya and 37yb. Therefore, in this embodiment, the position of the slider 10 in the Y-axis direction is measured by taking the midpoint DP of the detection points DPya and DPyb as the actual measurement point. The midpoint DP coincides with the illumination point of the measurement beams LBx1 and LBX2 on the grating RG1.

[0090] That is, in this embodiment, the measurement of the position information of the slider 10 in the X-axis and Y-axis directions has a common detection point. The actuators of the three vibration damping devices 14 are controlled in real time by the control device 60i so that the position of the detection point in the XY plane is consistent with the detection center of the mark detection system MDS, for example, on the order of nm. The control of the actuators of the three vibration damping devices 14 is based on the relative position information between the mark detection system MDS (measuring unit 40) and the fixed plate 12 measured by the second position measurement system 50. Therefore, in this embodiment, the control device 60i uses the encoder system 33, thereby enabling the measurement of the position information of the slider 10 in the XY plane at the closest point below the detection center of the mark detection system MDS (on the back side of the slider 10) when measuring the alignment marks on the wafer W mounted on the slider 10. Furthermore, the control device 60i measures the rotation of the slider 10 in the θz direction based on the difference between the measured values ​​of a pair of Y-reading heads 37ya and 37yb.

[0091] The laser interferometer system 35 allows the length measuring beam to be incident on the measuring section (the surface on which the grating RG1 is formed) of the lower surface of the slider 10, and receives its return beam (e.g., reflected light from the surface on which the grating RG1 is formed) to obtain position information of the slider 10. As shown in FIG7(A), the laser interferometer system 35 allows four length measuring beams LBz1, LBz2, LBz3, and LBz4 to be incident on the lower surface 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 FIG9) that respectively illuminate the four length measuring beams LBz1, LBz2, LBz3, and LBz4. In this embodiment, the laser interferometers 35a to 35d constitute four Z-reading heads.

[0092] In the laser interferometer system 35, as shown in Figures 7(A) and 7(B), four length measuring beams LBz1, LBz2, LBz3, and LBz4 are emitted from four points parallel to the Z-axis at each vertex of a square. This square is centered at the detection point DP and has two sides parallel to the X-axis and two sides parallel to the Y-axis. The emission points (irradiation points) of length measuring beams LBz1 and LBz4 are equidistant from the line LX on the line LYa, and the emission points (irradiation points) of the remaining length measuring beams LBz2 and LBz3 are equidistant from the line LX on the line LYb. In this embodiment, the surface on which the grating RG1 is formed also serves as a reflecting surface for each length measuring beam from the laser interferometer system 35. The control device 60i uses the laser interferometer system 35 to measure the position of the slider 10 in the Z-axis direction and the rotation in the θx and θy directions. Furthermore, as clearly explained above, the slider 10 is not actively driven relative to the fixed plate 12 by the aforementioned drive system 20 in the Z-axis, θx, and θy directions. However, since it is suspended and supported on the fixed plate 12 by the four air bearings 18 located at the four corners of the bottom surface, the actual position of the slider 10 in the Z-axis, θx, and θy directions changes on the fixed plate 12. That is, the slider 10 is actually movable relative to the fixed plate 12 in the Z-axis, θx, and θy directions. In particular, the displacement of the slider 10 in the θx and θy directions will cause measurement errors (Abbe errors) in the encoder system 33. Considering this point, the position information of the slider 10 in the Z-axis, θx, and θy directions is measured by the first position measurement system 30 (laser interferometer system 35).

[0093] Furthermore, to measure the position of the slider 10 in the Z-axis direction and its rotation in the θx and θy directions, it is sufficient to allow the light beam to be incident on three different points on the surface where the grating RG1 is formed. Therefore, only three Z-readers, such as in a laser interferometer, are needed. Additionally, a protective glass for protecting the grating RG1 can be provided on the lower surface of the slider 10, and a wavelength selective filter can be provided. This wavelength selective filter allows each measurement beam from the encoder system 33 to pass through the surface of the protective glass, while blocking the transmission of each measurement beam from the laser interferometer system 35.

[0094] As explained above, the control device 60i can measure the position of the slider 10 in six degrees of freedom by using the encoder system 33 and laser interferometer system 35 of the first position measurement system 30. In this case, the optical path length of the measurement beam in the encoder system 33 is extremely short, and the optical path lengths of the two measurement beams LBx1 and LBx2 illuminating the grating RG1 from the X-reader 73x are approximately equal to each other, as are the optical path lengths of the two measurement beams LBya1 and LBya2 illuminating the grating RG1 from the Y-reader 37ya, and the optical path lengths of the measurement beams LByb1 and LByb2 illuminating the grating RG1 from the Y-reader 37yb. Therefore, the influence of air disturbances can be largely ignored. Thus, the encoder system 33 can measure the position information of the slider 10 in the XY plane (including the θz direction) with high precision. Furthermore, the encoder system 33 detects the points on the actual grating RG1 in the X and Y directions, and the laser interferometer system 35 detects the points on the lower surface of the slider 10 in the Z direction, respectively, all aligned with the detection center of the mark detection system MDS in the XY plane. Therefore, the so-called Abbe error caused by the deviation of the detection points from the detection center of the mark detection system MDS in the XY plane can be suppressed to a negligible level. Thus, by using the first position measurement system 30, the control device 60i can measure the position of the slider 10 in the X, Y, and Z directions with high accuracy, without the Abbe error caused by the deviation of the detection points from the detection center of the mark detection system MDS in the XY plane.

[0095] However, the Z-axis direction, which is parallel to the optical axis AX1 of the mark detection system MDS, is not the position information of the slider 10 in the XY plane measured by the encoder system 33 on the surface of the wafer W. That is, the Z position of the arrangement surface of the grating RG1 is not consistent with the Z position of the surface of the wafer W. Therefore, when the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, if the slider 10 is positioned based on the measurement values ​​of each encoder of the encoder system 33, the result will be a positioning error (a kind of Abbe error) corresponding to the tilt of the grating RG1 relative to the XY plane due to the difference ΔZ between the Z position of the arrangement surface of the grating RG1 and the surface of the wafer W (i.e., the position of the detection point of the encoder system 33 and the detection center (detection point) of the mark detection system MDS in the Z-axis direction). However, this positioning error (position control error) can be calculated using the difference ΔZ and the pitch and roll amounts θx and θy through simple calculations, and set as a compensation value. Based on the corrected position information obtained by correcting the measurement values ​​of the encoder system 33 (each encoder) with this compensation value, the slider 10 is positioned, thereby no longer being affected by the aforementioned Abbe error. Alternatively, instead of correcting the measurement values ​​of the encoder system 33 (each encoder), one or more pieces of information used to move the slider, such as the target position of the slider 10 to be positioned, can be corrected based on the aforementioned compensation value.

[0096] Furthermore, when the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the read head 32 can also be moved to avoid positioning errors caused by the tilt. That is, when the first position measurement system 30 (e.g., the interferometer system 35) measures that the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the stationary plate 12 holding the read head 32 can be moved based on the position information obtained using the first position measurement system 30. As described above, the stationary plate 12 can be moved using the vibration damping device 14.

[0097] Furthermore, when the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the position information of the marker obtained by the marker detection system MDS can be corrected based on the positioning error caused by the tilt.

[0098] The second position measurement system 50, as shown in Figures 4, 5(A), and 5(B), includes: a pair of read heads 52A and 52B, respectively disposed on the lower surface of one end and the other end of the aforementioned read head mounting member 51 along its length; and scale members 54A and 54B, respectively disposed opposite to the read heads 52A and 52B. The upper surfaces of the scale members 54A and 54B are at the same height as the surface of the wafer W held in the wafer holder WH. Reflective 2D gratings RG2a and RG2b are formed on the upper surfaces of the scale members 54A and 54B, respectively. The 2D gratings RG2a and RG2b each include: a reflective diffraction lattice (X-diffraction lattice) with the X-axis direction as the periodic direction; and a reflective diffraction lattice (Y-diffraction lattice) with the Y-axis direction as the periodic direction. The spacing between the lattice lines of the X-diffraction lattice and the Y-diffraction lattice is set to, for example, 1 μm.

[0099] The scale components 54A and 54B are made of materials with low thermal expansion coefficients, such as the aforementioned zero-expansion material, and are fixed to the plate 12 by means of the support component 56, as shown in Figures 5(A) and 5(B). In this embodiment, the dimensions of the scale components 54A and 54B and the support component 56 are specified such that the gratings RG2a and RG2b face each other with a gap of about a few mm between them.

[0100] As shown in Figure 8, one of the reading heads 52A, fixed to the lower surface of the +X side end of the reading head mounting member 51, includes an XZ reading head 58X1 with the X and Z axes as the measurement directions and a YZ reading head 58Y1 with the Y and Z axes as the measurement directions, both housed within the same frame. The XZ reading head 58X1 (more precisely, the illumination point of the measurement beam emitted by the XZ reading head 58X1 on the grating RG2a) and the YZ reading head 58Y1 (more precisely, the illumination point of the measurement beam emitted by the YZ reading head 58Y1 on the 2D grating RG2a) are arranged on the same straight line parallel to the Y axis.

[0101] Another read head 52B is symmetrically arranged with read head 52A on a straight line (hereinafter referred to as the reference axis) LV that passes through the optical axis AX1 of the mark detection system MDS and is parallel to the Y-axis. However, it is constructed in the same way as read head 52A. That is, read head 52B has XZ read head 58X2 and YZ read head 58Y2 symmetrically arranged on the reference axis LV. The illumination points of the measurement beams that are respectively irradiated from XZ read head 58X2 and YZ read head 58Y2 onto the grating RG2b are set on the same straight line parallel to the Y-axis.

[0102] Each of the XZ read heads 58X1 and 58X2 and the YZ read heads 58Y1 and 58Y2 can, for example, use an encoder read head with the same configuration as the displacement measurement sensor read head disclosed in U.S. Patent No. 7,561,280.

[0103] The read heads 52A and 52B respectively utilize scale members 54A and 54B to construct an XZ linear encoder for measuring the positions of gratings RG2a and RG2b in the X-axis direction (X position) and the Z-axis direction (Z position), and a YZ linear encoder for measuring the positions 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, which are fixed to the fixed disk 12 via support member 56. The read heads 52A and 52B are mounted on the read head mounting member 51, which is integrated with the mark detection system MDS. As a result, the read heads 52A and 52B measure the position of the fixed disk 12 relative to the mark detection system MDS (the positional relationship between the mark detection system MDS and the fixed disk 12). For convenience, the XZ linear encoder and YZ linear encoder will use the same symbols as the XZ reader 58X1, 58X2 and YZ reader 58Y1, 58Y2 respectively, and will be referred to as XZ linear encoder 58X1, 58X2 and YZ linear encoder 58Y1, 58Y2 (see Figure 9).

[0104] In this embodiment, a 4-axis encoder 581 is constructed from XZ linear encoder 58X1 and YZ linear encoder 58Y1. This 4-axis encoder 581 measures the position information of the fixed plate 12 relative to the mark detection system MDS in each of the X, Y, Z, and θx directions (see Figure 9). Similarly, a 4-axis encoder 582 is constructed from XZ linear encoder 58X2 and YZ linear encoder 58Y2. This 4-axis encoder 582 measures the position information of the fixed plate 12 relative to the mark detection system MDS in each of the X, Y, Z, and θx directions (see Figure 9). At this time, based on the position information of the fixed plate 12 relative to the mark detection system MDS in the Z-axis direction measured by the 4-axis encoders 581 and 582 respectively, the position information of the fixed plate 12 relative to the mark detection system MDS in the θy direction is calculated (measured), and based on the position information of the fixed plate 12 relative to the mark detection system MDS in the Y-axis direction measured by the 4-axis encoders 581 and 582 respectively, the position information of the fixed plate 12 relative to the mark detection system MDS in the θz direction is calculated (measured).

[0105] Therefore, a second position measurement system 50 is constituted by 4-axis encoders 581 and 582. This second position measurement system 50 measures the position information of the fixed plate 12 relative to the mark detection system MDS in the 6 degrees of freedom direction, that is, the information on the relative position of the mark detection system MDS and the fixed plate 12 in the 6 degrees of freedom direction. The information on the relative position of the mark detection system MDS and the fixed plate 12 in the 6 degrees of freedom direction measured by the second position measurement system 50 is constantly supplied to the control device 60i. Based on the relative position information, the control device 60i controls the actuators of the three vibration damping devices 14 in real time so that the detection point of the first position measurement system 30 is in the desired positional relationship relative to the detection center of the mark detection system MDS. Specifically, the position of the detection point of the first position measurement system 30 in the XY plane is consistent with the detection center of the mark detection system MDS, for example, at the nm level, and the surface of the wafer W on the slider 10 is consistent with the detection position of the mark detection system MDS. At this point, the aforementioned straight line CL coincides with, for example, the reference axis LV. Furthermore, as long as the detection point of the first position measurement system 30 can be controlled to achieve the desired positional relationship relative to the detection center of the marker detection system MDS, the second position measurement system 50 can measure relative position information in all directions of the 6 degrees of freedom.

[0106] As can be seen from the description of the first position measurement system 30 and the second position measurement system 50, in the measuring device 100i, the first position measurement system 30 and the second position measurement system 50 constitute a position measurement system, which measures the position information of the slider 10 relative to the mark detection system MDS in the 6-degree-of-freedom direction.

[0107] Figure 9 shows a block diagram illustrating the input / output relationships of the control device 60i, which mainly constitutes the control system of the measuring device 100i in this embodiment. The control device 60i includes a workstation (or microcomputer), etc., and uniformly controls all components of the measuring device 100i. As shown in Figure 9, the measuring device 100i includes a wafer transport system 70i, a portion of which is disposed within the chamber 101i along with the components shown in Figure 4. The wafer transport system 70i, as previously described, may be, for example, composed of a horizontal multi-joint robot.

[0108] Next, a series of actions in which a batch of wafers is processed in the measuring device 100i configured as described above will be explained based on the flowchart of FIG10 corresponding to the processing algorithm of the control device 60i.

[0109] As a premise, the measurement object of the measuring device 100i, namely the wafer W, is a 300 mm wafer. On the wafer W, through exposure prior to the previous layer, a plurality of regions (hereinafter referred to as irradiation regions) are formed in a matrix arrangement, for example, I (for example, I=98). Around the boundaries of each irradiation region or the boundaries within each irradiation region (when multiple wafers are taken from one irradiation region), a plurality of marks are provided, such as search alignment marks (search marks) for search alignment, wafer alignment marks (wafer marks) for fine alignment, etc. These multiple marks are formed together with the irradiation regions. In this embodiment, two-dimensional marks are used as search marks and wafer marks.

[0110] Furthermore, the measuring device 100i can be set with multiple measurement modes, each with different mark detection conditions for the Mark Detection System (MDS). As an example of multiple measurement modes, mode A and mode B can be set. Mode A detects one wafer mark in each irradiated area for all wafers, while mode B detects multiple wafer marks in all irradiated areas for the initial predetermined number of wafers in the batch. Based on the detection results of these wafer marks, for the remaining wafers in the batch, the wafer marks that become the detection targets for each irradiated area are determined, and the determined wafer marks are detected.

[0111] Furthermore, the operator of the measuring device 100i pre-inputs the information required for alignment measurement of the wafer W via an input device (not shown), and stores it in the memory of the control device 60i. Here, the information required for alignment measurement includes various types of information such as the thickness of the wafer W, the flatness information of the wafer holding device WH, the design information of the irradiation area on the wafer W, and the arrangement of alignment marks. Moreover, the measurement mode setting information is, for example, pre-input by the operator via an input device (not shown).

[0112] The processing algorithm corresponding to the flowchart in Figure 10 begins, for example, when the operator or host computer 2000 indicates that a measurement has started. At this time, the plurality of wafers (e.g., 25 wafers) contained in a batch are stored in a wafer carrier at a predetermined position within the chamber 101i of the measurement device 100i. Not limited to this, the wafers in a batch can also be sequentially moved into the measurement device 100i in parallel with the measurement processing of the measurement device 100i. For example, under the management of the measurement system control device 530, which controls the robot 516, the conveying component 524, and the conveying component 526, the wafers in a batch within a predetermined FOUP 520 can be sequentially removed by the robot 516 and conveyed to a predetermined transport position in the measurement device 100i by the conveying component 524. At this time, the processing algorithm corresponding to the flowchart in Figure 10 begins when the measurement system control device 530 gives the control device 60i and the robot 516 a command to start the transport.

[0113] Furthermore, when the exposure device 200 is connected to the measurement system 500, the exposure control device 220 of the exposure device 200 can instruct the measurement system control device 530 to start the measurement without going through the host computer 2000.

[0114] Furthermore, the measuring device 100i is equipped with a barcode reader (not shown). During wafer transport in the wafer transport system 70i (see Figure 9), the barcode reader is used to appropriately read the identification information of each wafer, such as wafer number and batch number. For simplicity, the following explanation regarding the reading of wafer identification information using a barcode reader is omitted. Alternatively, the measuring device 100i may not each have its own barcode reader. For example, a barcode reader may be configured in the transport system 521.

[0115] First, in step S102, the count value i of the counter representing the wafer number in the batch is initialized to 1 (i←1).

[0116] In the next step S104, the wafer W is loaded onto the slide 10. The loading of the wafer W is managed by the control device 60i and is achieved through the wafer transport system 70i and the up-and-down moving member on the slide 10. Specifically, the wafer transport system 70i transports the wafer W from the wafer carrier (or transport position) to above the slide 10 at the loading position. The drive device 13 drives the up-and-down moving member upwards by a predetermined amount, thereby transferring the wafer W to the up-and-down moving member. Then, after the wafer transport system 70i retracts from above the slide 10, the drive device 13 drives the up-and-down moving member downwards, thereby placing the wafer W onto the wafer holder WH on the slide 10. Then, the vacuum pump 11 is turned on, and the wafer holder WH is used to vacuum-adsorb the wafer W loaded on the slide 10. Furthermore, when multiple wafers contained in a batch are sequentially loaded into the measuring device 100i in parallel with the measurement processing of the measuring device 100i, before the wafer loading, the multiple wafers in the predetermined FOUP 520 are sequentially removed by the robot 516 and handed over from the robot 516 to the transport member 524, and then transported by the transport member 524 to the predetermined transport position of the measuring device 100i and handed over to the wafer transport system 70i.

[0117] In the next step S106, the position of wafer W in the Z-axis direction (Z position) is adjusted. Before adjusting the Z position, the control device 60i, based on the relative position information of the mark detection system MDS and the fixed plate 12 in the Z-axis direction, θy direction, and θx direction measured by the second position measurement system 50, controls the internal pressure of the air dampers of the three vibration damping devices 14 (the driving force in the Z-axis direction generated by the vibration damping devices 14) to set the fixed plate 12 so that its upper surface is parallel to the XY plane and the Z position is at a predetermined reference position. Wafer W can be considered to have a uniform thickness. Therefore, in step S106, the control device 60i adjusts the driving force in the Z-axis direction generated by the three vibration damping devices 14, such as the internal pressure (amount of compressed air) of the air damper, based on the thickness information of the wafer W in the memory, to drive the stationary plate 12 along the Z-axis direction and adjust the Z position of the wafer W surface, so that the wafer W surface is set within a range where the focus position of the optical system can be adjusted by the autofocus function of the mark detection system MDS. Furthermore, when the measurement unit 40 is equipped with a focus position detection system, the control device 60i can also adjust the Z position of the wafer surface based on the detection result (output) of the focus position detection system. For example, the mark detection system MDS can also be equipped with a focus position detection system, which detects the position of the wafer W surface in the Z-axis direction through the front optical element (object optical element). Furthermore, the adjustment of the Z-position of the wafer W surface based on the detection results of the focal position detection system can be performed by moving the fixed plate 12 using the vibration damping device 14, causing the sliding member 10 to move together with the fixed plate 12. Alternatively, a drive system 20, which can drive the sliding member 10 not only in the XY plane but also in the Z-axis, θx, and θy directions, can be used to move the sliding member 10. Furthermore, the adjustment of the Z-position of the wafer surface can also include the adjustment of the wafer surface tilt. By using the drive system 20 to adjust the wafer surface tilt, in cases where an error (an Abbe error) may occur due to the difference ΔZ between the Z-position of the grating RG1 and the surface of the wafer W, only one of the countermeasures described above needs to be implemented.

[0118] In the next step S108, wafer W is searched and aligned. Specifically, a marker detection system (MDS) is used to detect at least two search markers located approximately symmetrically around the center of wafer W at its periphery. The control device 60i controls the drive system 20 to drive the slider 10, positioning each search marker within the detection area (detection field of view) of the marker detection system (MDS), and acquires measurement information from the first position measurement system 30 and the second position measurement system 50. Based on the detection signal obtained when the search markers formed on wafer W are detected using the marker detection system (MDS), and the measurement information from the first position measurement system 30 (and the second position measurement system 50), the position information of each search marker is determined.

[0119] More specifically, the control device 60i calculates the position coordinates of the two search marks in the reference coordinate system based on the detection results of the marker detection system MDS output from the signal processing device 49 (the relative positional relationship between the detection center (index center) of the marker detection system MDS obtained from the detection signal and each search mark), and the measurement values ​​of the first position measurement system 30 (and the measurement values ​​of the second position measurement system 50) during the detection of each search mark. That is, the control device 60i calculates the position coordinates of the two search marks in the reference coordinate system based on the relative positional relationship between the detection center (index center) of the marker detection system MDS obtained from the detection signal of the marker detection system MDS and each search mark, the measurement values ​​of the first position measurement system 30 during the detection of each search mark, and the measurement values ​​of the second position measurement system 50. Here, the reference coordinate system is an orthogonal coordinate system defined by the length measuring axis of the first position measurement system 30.

[0120] Then, the residual rotational error of wafer W is calculated from the position coordinates of the two search markers, and the slider 10 is rotated slightly to make the rotational error approximately zero. This completes the search and alignment of wafer W. Furthermore, since wafer W is actually loaded onto slider 10 in a pre-aligned state, the center position deviation of wafer W is negligible, and the residual rotational error is very small.

[0121] In the next step S110, it is determined whether the set measurement mode is mode A. If the determination in step S110 is affirmative, that is, if mode A is set, proceed to step S112.

[0122] In step S112, alignment measurements are performed for all wafers (full illumination area 1-point measurement, in other words, full illumination area EGA measurement), that is, measuring one wafer mark for each of the 98 illumination areas. Specifically, the control device 60i calculates the position coordinates of the wafer marks on the wafer W in the reference coordinate system, i.e., the position coordinates of the illumination area, in the same way as the position coordinates of each search mark during the aforementioned search alignment. However, unlike during search alignment, the calculation of the position coordinates of the illumination area must use the measurement information from the second position measurement system 50. The reason is as follows: As mentioned above, the control device 60i controls the actuators of the three vibration damping devices 14 in real time based on the measurement information of the second position measurement system 50, so that the position of the detection point of the first position measurement system 30 in the XY plane is consistent with the detection center of the mark detection system MDS, for example, at the nm level, and the surface of the wafer W on the slider 10 is consistent with the detection position of the mark detection system MDS. However, when detecting the wafer mark, no compensation is performed to make the position of the detection point of the first position measurement system 30 in the XY plane consistent with the detection center of the mark detection system MDS, for example, at the nm level. Therefore, the positional deviation between the two must be taken into account as a compensation value to calculate the position coordinates of the irradiated area. For example, by using the above compensation value 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.

[0123] Here, during the measurement at point 1 in the fully irradiated area, the control device 60i, based on the measurement information from the first position measurement system 30 and the second position measurement system 50, moves the slider 10 (wafer W) via the drive system 20 in at least one of the X-axis and Y-axis directions, positioning the wafer mark 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-repeating manner to perform a measurement at point 1 in the fully irradiated area.

[0124] Furthermore, when the measurement unit 40 is equipped with a focal position detection system, the control device 60i can adjust the Z position of the wafer surface based on the detection result (output) of the focal position detection system, just as described in step S106.

[0125] During the alignment measurement (one-point measurement of the full illumination area) for all wafers in step S112, if the slider 10 moves in the XY plane, an unbalanced load will act on the stationary plate 12 along with this movement. However, in this embodiment, the control device 60i performs feedforward control on the three vibration damping devices 14 individually based on the X and Y coordinate positions of the slider contained in the measurement information of the first position measurement system 30, thereby individually controlling the driving force in the Z-axis direction generated by each vibration damping device 14 so that the effects of the unbalanced load cancel each other out. Furthermore, the control device 60i may also predict the unbalanced load acting on the stationary plate 12 based on the known movement path information of the slider 10 without using the measurement information of the first position measurement system 30, and perform feedforward control on the three vibration damping devices 14 individually so that the effects of the unbalanced load cancel each other out. Furthermore, in this embodiment, the unevenness information (hereinafter referred to as the holder flatness information) of the wafer holding surface (defined by the upper surfaces of the plurality of pins of the pin clamp) of the wafer holder WH is determined in advance through experiments, etc. Therefore, during alignment measurement (e.g., one-point measurement of the full illumination area), when the slider 10 is moved, the control device 60i performs feedforward control on the three vibration damping devices 14 based on the holder flatness information, thereby finely adjusting the Z position of the fixed plate 12 so that the area on the surface of the wafer W containing the wafer mark as the object of measurement is quickly located within the depth of focus of the optical system of the mark detection system MDS. Furthermore, either or both of the above-mentioned feedforward control for canceling out the effects of the unbalanced load acting on the fixed plate 12 and feedforward control based on the holder flatness information may not be performed.

[0126] Furthermore, when the magnification of the marking detection system MDS is adjustable, it can be set to a low magnification during search alignment and a high magnification during alignment measurement. Also, when the center position deviation and residual rotation error of the wafer W loaded onto the slider 10 are so small as to be negligible, step S108 can be omitted.

[0127] In the full illumination area 1-point measurement in step S112, the measured values ​​of the position coordinates of the sampled illumination area (sampled illumination area) in the reference coordinate system used in the subsequent EGA calculation are detected. The sampled illumination area refers to a specific plurality (at least 3) of illumination areas on the wafer W that are predetermined for use in the subsequent EGA calculation. Furthermore, in the full illumination area 1-point measurement, all illumination areas on the wafer W become the sampled illumination area. After step S112, proceed to step S124.

[0128] On the other hand, when the determination in step S110 is negative, that is, when it is set to B mode, it proceeds to step S114, and determines whether the count value i is less than a predetermined number K (K is a natural number satisfying 1 < K < I and is a predetermined number, for example, 4). Furthermore, the count value i is incremented in step S128 described later. And when the determination in this step S114 is affirmative, it proceeds to step S120 to perform multi-point measurement of the entire irradiation area. Here, the so-called multi-point measurement of the entire irradiation area means measuring a plurality of wafer marks respectively for all irradiation areas on the wafer W. The plurality of wafer marks to be measurement objects are predetermined. For example, a plurality of wafer marks whose arrangement can calculate the shape of the irradiation area (error from the shape of the ideal lattice) by statistical operation can also be set as measurement objects. The measurement process is the same as that of the single-point measurement of the entire irradiation area in step S112 except for the number of marks as measurement objects, so the detailed description is omitted. After step S120, it proceeds to step S124.

[0129] On the other hand, when the determination in step S114 is negative, it proceeds to step S116 and determines whether the count value i is less than K + 1. Here, when the determination in this step S116 is affirmative, it is the case where the count value i is i ≧ K and i < K + 1, and thus it is the case where i = K.

[0130] When the determination in step S116 is affirmative, it advances to step S118, and based on the detection results of the wafer marks of K - 1 wafers W (for example, 3 wafers when K = 4) that have been measured so far, determines the wafer marks to be set as measurement objects for each irradiation area. Specifically, it determines for each irradiation area whether the detection of one wafer mark is sufficient, or whether a plurality of wafer marks should be detected. In the latter case, it also determines which wafer mark is to be set as the detection object. For example, for each irradiation area, the difference (absolute value) between the measured position and the designed position of each of the plurality of wafer marks is obtained, and based on whether the difference between the maximum value and the minimum value of this difference exceeds a certain threshold, it is determined for each irradiation area whether a plurality of wafer marks should be detected, or whether the detection of one wafer mark is sufficient. In the former case, for example, the wafer marks to be detected are determined in such a way as to include the wafer mark with the maximum difference (absolute value) between the measured position and the designed position and the wafer mark with the minimum difference. After step S118, it advances to step S122.

[0131] On the other hand, if the judgment in step S116 is negative, proceed to step S122. Here, the judgment in step S116 is negative when the count value i satisfies K+1≦i. Before this, the count value i must be K, and in step S118, it is determined that each irradiated area should be set as the wafer mark of the measurement object.

[0132] In step S122, the wafer markers determined in step S118 for each irradiation area to be the measurement targets are measured. The measurement process is the same as the one-point measurement of the entire irradiation area in step S112, except for the number of markers used as measurement targets; therefore, a detailed explanation is omitted. After step S122, proceed to step S124.

[0133] As can be seen from the description so far, in the case of mode B, for wafers 1 to K-1 (e.g., wafer 3) in a batch, multi-point measurement of the full irradiation area is performed. For wafers K (e.g., wafer 4) to I (e.g., wafer 25), the wafer mark determined by each irradiation area is measured based on the results of the multi-point measurement of the full irradiation area of ​​the initial K-1 (e.g., wafer 3) wafers.

[0134] In step S124, the wafer marker position information measured in any of steps S112, S120, and S122 is used to perform EGA calculation. EGA calculation refers to the statistical calculation described below: after the wafer marker measurement (EGA measurement), based on the difference between the designed and measured values ​​of the position coordinates of the sampled irradiation area, statistical calculations such as the least squares method are used to determine the coefficients of the model formula expressing the relationship between the position coordinates of the irradiation area and the correction amount of those position coordinates.

[0135] In this embodiment, as an example, the next model formula is used to calculate the correction amount of the position coordinates of the irradiated area from the design value.

[0136] [Formula 1]

[0137] Here, dx and dy are the corrections of the position coordinates of the irradiated area from the design values ​​in the X-axis and Y-axis directions, respectively. X and Y are the design position coordinates of the irradiated area in the wafer coordinate system with the center of wafer W as the origin. That is, the above equation (1) is a polynomial related to the design position coordinates X and Y of each irradiated area in the wafer coordinate system with the center of wafer as the origin. It is a model formula expressing the relationship between the position coordinates X and Y and the position coordinate correction (alignment correction component) dx and dy of the irradiated area. Furthermore, in this embodiment, the rotation between the reference coordinate system and the wafer coordinate system is eliminated by the aforementioned search alignment. Therefore, in the following, the reference coordinate system and the wafer coordinate system will not be specifically distinguished, and all will be described as the reference coordinate system.

[0138] Using model formula (1), the correction amount of the position coordinates of the irradiated area can be obtained based on the position coordinates X and Y of the irradiated area of ​​the wafer W. However, in order to calculate the correction amount, the coefficients a0, a1, ..., b0, b1, ... must be obtained. After EGA measurement, based on the data of the difference between the design value and the measured value of the position coordinates of the sampled irradiated area, the coefficients a0, a1, ..., b0, b1, ... of the above formula (1) are obtained by statistical calculations such as the least squares method.

[0139] After determining the coefficients a0, a1, ..., b0, b1, ... of the model formula (1), the position coordinates X and Y of each irradiated area (region) on the wafer coordinate system are substituted into the model formula (1) after the coefficients are determined, and the correction amounts dx and dy of the position coordinates of each irradiated area are obtained. In this way, the true arrangement of multiple irradiated areas (regions) on the wafer W can be obtained (as a deformation component, it not only has linear components, but also includes nonlinear components).

[0140] However, in the case of wafer W that has already been exposed, due to the influence of the process up to this point, the waveform of the detection signal obtained as a measurement result may not be good for all wafer marks. If the location of wafer marks with poor measurement results (detection signal waveform) is included in the above EGA calculation, the positional error of wafer marks with poor measurement results (detection signal waveform) will adversely affect the calculation results of coefficients a0, a1, ..., b0, b1, ...

[0141] Therefore, in this embodiment, the signal processing device 49 only sends the measurement results of wafer markers with good measurement results to the control device 60i. The control device 60i uses the positions of all wafer markers that have received the measurement results to perform the above-mentioned EGA calculation. Furthermore, there is no particular limitation on the degree of the polynomial in the above equation (1). The control device 60i associates the result of the EGA calculation with the wafer identification information (e.g., wafer number, batch number) and stores it as an alignment history data file in an internal or external memory device. Furthermore, the alignment history data file may also contain information other than the EGA calculation result (e.g., information about the markers used in the EGA calculation).

[0142] When the EGA calculation in step S124 ends, proceed to step S126 to unload the wafer W from the slider 10. This unloading is performed under the control of the control device 60i, in the reverse of the loading process in step S104, by the wafer transport system 70i and the up-and-down moving component on the slider 10. Furthermore, in parallel with the measurement processing of the measurement device 100i, when a batch of wafers are sequentially loaded into and out of the measurement device 100i, the wafer W that has completed the measurement is delivered to the transport component 526 by the wafer transport system 70i, and then transported to the aforementioned unloading side wafer transport position by the transport component 526, before being returned to the predetermined FOPU 520 by the robot 516.

[0143] In the next step S128, the counter value i is incremented by 1 (i←i+1), and then the process proceeds to step S130 to determine whether the counter value i is greater than the total number of wafers I in the batch. If the determination in step S130 is negative, it is determined that the processing of all wafers in the batch has not yet been completed, and the process returns to step S104. Thereafter, the processing (including the determination) from step S104 to step S130 is repeated until the determination in step S130 is positive.

[0144] Furthermore, if the determination in step S130 is affirmative, it is determined that all wafers in the batch have been processed, thereby ending a series of processes in this procedure.

[0145] As explained above, during alignment measurement using the measuring device 100i, for each of the I (e.g., 98) irradiation areas on the wafer W, the position information (coordinate position information) of at least one wafer marker is measured. Using this position information, the coefficients a0, a1, ..., b0, b1, ... of the above equation (1) are calculated using statistical operations such as the least squares method. Therefore, for the deformation components of the wafer lattice, not only the linear components can be accurately determined, but even the nonlinear components can be accurately determined. Here, the wafer lattice refers to the lattice formed by connecting the centers of the irradiation areas on the wafer W, which are arranged according to the irradiation area mapping (data related to the arrangement of the irradiation areas formed on the wafer W). The correction amount (alignment correction component) dx, dy of the position coordinates of the irradiation areas for the plurality of irradiation areas is precisely the deformation component of the wafer lattice. Furthermore, in this specification, the wafer lattice is referred to simply as the "lattice" or "the arrangement of irradiated areas (or irradiated areas)".

[0146] In the measurement system 500 of this embodiment, three measuring devices 1001-1003 can perform measurement processing in parallel along the aforementioned flowchart. That is, by means of measuring devices 1001-1003, for each batch of wafers housed in the wafer carrier, a total of three batches of wafers, the position measurement of at least one wafer mark can be performed on all irradiated areas of each wafer in the measurement processing time of one batch of wafers. For the deformation components of the wafer lattice, not only the linear components can be accurately determined, but even the nonlinear components can be accurately determined. Furthermore, when wafers are loaded into and unloaded from each measurement device 100i in parallel with measurement processing, the wafers that have completed measurement can also be processed in parallel for one batch each of wafers loaded into the three FOUP 520s in the three loading ports 514, for a total of three batches. This allows for the measurement of the position of at least one wafer mark in all irradiated areas of each wafer in the three batches of wafers in the processing time of one batch of wafers. For the deformation components of the wafer lattice, not only the linear components can be accurately determined, but even the nonlinear components can be accurately determined.

[0147] The information of the wafer lattice of each wafer obtained, such as the data of the deformation components of the wafer lattice of each wafer obtained (the data of the model formula (1) after the determination coefficients a0, a1, ..., b0, b1, ...), is sent by the control device 60i of the measurement device 100i to the measurement system control device 530 as part of the alignment history data file of each wafer. The measurement system control device 530 stores the alignment history data file containing the received information of the wafer lattice of each wafer, such as the data of the deformation components of the wafer lattice of each wafer received (the data of the model formula (1) after the determination coefficients a0, a1, ..., b0, b1, ...), for example, in the memory device inside each wafer.

[0148] When the measurement system control device 530 finishes measuring all wafers in a batch, it sends the information (alignment history data file) of the wafer lattice of each of the plurality of wafers in that batch to the host computer 2000. Needless to say, the information (alignment history data file) of the wafer lattice sent from the measurement system 500 also includes data on the nonlinear components of the wafer lattice.

[0149] Furthermore, the control device 60i of the measuring device 100i can be connected to the host computer 2000 via LAN 1500, so that the information of the wafer grid (alignment history data file) can be sent from the control device 60i to the host computer 2000 without going through the measuring system control device 530.

[0150] Furthermore, in the above embodiment, the self-measurement system 500 sends (outputs) information about the wafer grid, but the information (data) sent by the self-measurement system is not limited to this. For example, the coordinate position information of a plurality of wafer markers measured by the measurement device 100i can also be sent (output) as at least part of the alignment history data of each wafer.

[0151] As an example, the exposure apparatus 200, which constitutes part of the substrate processing system 1000, is a projection exposure apparatus (scanner) using a step-scan method. In Figure 11, the components within the chamber of the exposure apparatus 200 are shown in a partially omitted manner.

[0152] As shown in Figure 11, the exposure apparatus 200 includes an illumination system IOP, a mark plate stage RST for holding the mark plate R, a projection unit PU for projecting the image of the pattern formed on the mark plate R onto a wafer W coated with a resist, a wafer stage WST for moving the wafer W in the XY plane, and a control system for the above. The exposure apparatus 200 includes a projection optical system PL, which has an optical axis AX in the Z-axis direction parallel to the optical axis AX1 of the aforementioned mark detection system MDS.

[0153] The illumination system IOP includes a light source and an illumination optical system connected to the light source via a light-transmitting optical system. For a slit-shaped illumination area IAR extending elongated along the X-axis direction (orthogonal to the paper plane in Figure 11) on a scribe line R defined (limited) by a scribe line mask (masking system), illumination is provided with approximately equal illuminance by an illumination light (exposure light) IL. The configuration of the illumination system IOP is disclosed, for example, in U.S. Patent Application Publication No. 2003 / 0025890. Here, as an example, ArF excimer laser light (wavelength 193 nm) is used as the illumination light IL.

[0154] The marking sheet stage RST is positioned below the illumination system IOP in Figure 11. The marking sheet stage RST can be driven in a small manner on the marking sheet stage plate (not shown in Figure 11, see Figure 12) in the horizontal plane (XY plane) by a marking sheet stage drive system 211 (not shown in Figure 11, see Figure 12) including a linear motor, and can be driven within a predetermined stroke range along the scanning direction (the left-right direction in the paper of Figure 11, i.e., the Y-axis direction).

[0155] A gradation piece R is placed on a gradation piece stage RST. The gradation piece R has a patterned area and a plurality of marks whose positional relationship to the patterned area is known, formed on its -Z side surface (pattern surface). The positional information of the gradation piece stage RST in the XY plane (including rotational information in the θz direction) is detected by a gradation piece laser interferometer (hereinafter referred to as "gradation piece interferometer") 214 through a moving mirror 212 (or a reflecting surface formed on the end face of the gradation piece stage RST), for example, always at a resolution of approximately 0.25 nm. The measurement information from the gradation piece interferometer 214 is supplied to the exposure control device 220 (see Figure 12). Furthermore, the positional information of the gradation piece stage RST in the XY plane can also be measured by an encoder instead of the gradation piece laser interferometer 214.

[0156] The projection unit PU is positioned below the gradation plate stage RST in Figure 11. 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, telecentric and has a predetermined projection magnification (e.g., 1 / 4x, 1 / 5x, or 1 / 8x). The gradation plate R is positioned such that its pattern surface is substantially aligned with the first surface (object surface) of the projection optical system PL, and a wafer W coated with resist (sensor) is positioned on the second surface (image surface) side of the projection optical system PL. Therefore, when the illumination area IAR on the gradation plate R is illuminated by the illumination light IL from the illumination system IOP, a reduced image (a reduced image of a portion of the circuit pattern) of the circuit pattern of the gradation plate R within the illumination area IAR is formed on the wafer W (hereinafter also referred to as the exposure area) IA, which is conjugate to the illumination area IAR, by the illumination light IL passing through the gradation plate R. Furthermore, by synchronously driving the tracing plate stage RST and the wafer stage WST, the tracing plate R moves relative to the illumination area IAR (illumination light IL) along the scanning direction (Y-axis direction), and the wafer W moves relative to the exposure area IA (illumination light IL) along the scanning direction (Y-axis direction). In this way, one illumination area (region) on the wafer W is scanned and exposed, and the pattern of the tracing plate R is transferred in the illumination area.

[0157] As an example, a projection optical system PL uses a refractive system, which comprises only a plurality of refractive optical elements (lens elements) arranged along an optical axis AX parallel to the Z-axis direction, for example, about 10 to 20 elements. Among the plurality of lens elements constituting the projection optical system PL, the plurality of lens elements on the object surface side (the caliper R side) are movable lenses. These movable lenses can be driven by a driving element (not shown) such as a piezoelectric element to be displaced along the Z-axis direction (the optical axis direction of the projection optical system PL) and driven along the tilt directions relative to the XY plane (i.e., the θx and θy directions). Furthermore, the imaging characteristic correction controller 248 (not shown in FIG11, see FIG12) independently adjusts the applied voltage to each driving element based on the instruction from the exposure control device 220, thereby individually driving each movable lens to adjust various imaging characteristics of the projection optical system PL (magnification, distortion, astigmatism, coma, image plane curvature, etc.). Furthermore, instead of moving the movable lens, or alternatively, the configuration could be as follows: an airtight chamber could be provided between adjacent specific lens elements inside the lens barrel 240, and the imaging characteristic correction controller 248 could control the pressure of the gas within the airtight chamber. Alternatively, the imaging characteristic correction controller 248 could be configured to shift the center wavelength of the illumination light IL. With these configurations, the imaging characteristics of the projection optical system PL could also be adjusted.

[0158] The wafer stage WST is driven along the X-axis and Y-axis directions with a predetermined stroke by a stage drive system 224 (shown as a block in Figure 11 for convenience), including a planar motor or linear motor, on the wafer stage plate 222, and is also driven slightly along the Z-axis, θx, θy, and θz directions. A wafer W is held on the wafer stage WST by a wafer holder (not shown) through vacuum adsorption or the like. In this embodiment, the wafer holder can hold a 300 mm wafer. Alternatively, a stage device can be used instead of the wafer stage WST. This stage device includes: a first stage that moves along the X-axis, Y-axis, and θz directions; and a second stage that moves slightly along the Z-axis, θx, and θy directions on the first stage. Furthermore, either or both of the wafer stage WST and the wafer holder of the wafer stage WST can be referred to as a "second substrate holding member".

[0159] The position information of the wafer stage WST in the XY plane (including rotation information (yaw (rotation θz in the θz direction), pitch (rotation θx in the θx direction), and roll (rotation θy in the θy direction))) is detected by a laser interferometer system (hereinafter referred to as the interferometer system) 218 ​​through a moving mirror 216 (or a reflecting surface formed on the end face of the wafer stage WST), for example, always at a resolution of approximately 0.25 nm. Alternatively, the position information of the wafer stage WST in the XY plane can also be measured by an encoder system instead of the interferometer system 218.

[0160] The measurement information from the interferometer system 218 is supplied to the exposure control device 220 (see Figure 12). Based on the measurement information from 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) through the stage drive system 224.

[0161] Furthermore, although the illustration is omitted in Figure 11, the position and tilt of the surface of wafer W in the Z-axis direction are measured, for example, by a focus sensor AFS (see Figure 12). This focus sensor AFS includes a multi-point focus position detection system with oblique incidence disclosed in U.S. Patent No. 5,448,332, etc. The measurement information of the focus sensor AFS is also supplied to the exposure control device 220 (see Figure 12).

[0162] Furthermore, a reference plate FP is fixed on the wafer stage WST, and the surface of the reference plate FP is at the same height as the surface of the wafer W. On the surface of the reference plate FP, a first reference mark for baseline measurement of the alignment detection system AS and a pair of second reference marks detected by the caliper alignment detection system described later are formed.

[0163] On the side of the lens barrel 240 of the projection unit PU, an alignment detection system AS is provided to detect alignment marks or first reference marks formed on the wafer W. As an example, the alignment detection system AS uses an imaging-type alignment sensor, specifically an FIA (Field Image Alignment) system, which uses broadband light such as halogen lamps to illuminate the mark and performs image processing on the image of the mark to measure the mark position. Alternatively, an image processing-type alignment detection system AS can be used instead, or a diffraction interferometry alignment system can be used in conjunction with the alignment detection system AS.

[0164] In the exposure apparatus 200, a pair of gradation plate alignment detection systems 213 (not shown in Figure 11, see Figure 12) are provided above the gradation plate stage RST, spaced at a predetermined distance along the X-axis. These systems can simultaneously detect a pair of gradation plate marks located at the same Y-position on the gradation plates R placed on the gradation plate stage RST. The detection results of the gradation plate alignment detection systems 213 are supplied to the exposure control device 220.

[0165] Figure 12 illustrates the input / output relationship of the exposure control device 220 using a block diagram. As shown in Figure 12, in addition to the above-described components, the exposure device 200 also includes a wafer transport system 270 connected to the exposure control device 220 for transporting wafers. The exposure control device 220 includes a microcomputer or workstation, which provides unified control over the entire device comprising the above-described components. The wafer transport system 270 is, for example, a horizontal multi-joint robot.

[0166] Referring back to Figure 1, although the illustration is omitted, the C / D 300 includes, for example, a coating section for applying a resist to the wafer, a developing section for developing the wafer, a baking section for pre-baking (PB) and post-exposure bake (PEB), and a wafer transport system (hereinafter referred to as the C / D internal transport system for convenience). The C / D 300 further includes a temperature control section 330 for adjusting the temperature of the wafer. The temperature control section 330 is typically a cooling section, for example, having a flat plate (temperature control device) called a cooling plate. The cooling plate is cooled, for example, by circulating cooling water. In addition, sometimes electronic cooling based on the Peltier effect is used.

[0167] The overlay measuring device 400 measures the overlay deviation by measuring the relative positional relationship between the images (resist images) of the first mark transferred during exposure on the lower layer and the second mark transferred during exposure on the current layer. The first mark and the second mark constitute an overlay measuring mark (positioning mark), which is formed together with each irradiated area on the wafer W after development has been completed in the C / D 300. Here, as a group of the first mark image and the corresponding second mark image, a resist image with a frame-within-a-frame mark can be used, for example. The frame-within-a-frame mark includes an outer frame mark and an inner frame mark disposed inside it.

[0168] The analysis device 3000 performs various analyses and calculations according to instructions from the host computer 2000. For example, the analysis device 3000 performs calculations according to a predetermined program based on the measurement results of the superposition deviation from the superposition measuring device 400, and calculates the correction value to be fed back to the exposure device 200.

[0169] In the substrate processing system 1000 of this embodiment, similar to the measuring device 100i, both the exposure device 200 and the C / D converter 300 are equipped with barcode readers (not shown). During the wafer transport system 270 (see Figure 12) and the C / D internal transport system (not shown), the barcode readers are used to appropriately read the identification information of each wafer, such as wafer number and batch number. For the sake of simplicity, the following explanations related to reading the identification information of each wafer using a barcode reader are omitted.

[0170] In the substrate processing system 1000, multiple wafers are processed continuously by the measurement system 500 and the lithography system, which includes the exposure apparatus 200 and the C / D converter 300. In the substrate processing system 1000, the measurement processing of the target wafer by the measurement system 500 and the processing of wafers after the measurement by the lithography system have been completed are performed independently of each other. Therefore, there is a limitation that the lithography system's processing is performed on wafers after the measurement by the measurement system 500 has been completed, but the overall processing sequence can be defined to maximize the overall output of the substrate processing system.

[0171] The following describes the operation flow when a lithography system, including an exposure unit 200 and a C / D converter 300, continuously processes multiple wafers.

[0172] First, the first wafer (designated W1) is removed from the wafer carrier within the C / D 300 chamber using an internal C / D transport system (e.g., a selective compliant assembly robot arm (SCARA)) and transported to the coating section. Here, resist coating begins. When resist coating is complete, the internal C / D transport system removes wafer W1 from the coating section and transports it to the baking section. Here, heat treatment (PB) of wafer W1 begins. Then, when PB is complete, the internal C / D transport system removes wafer W1 from the baking section and transports it to the temperature control section 330. Here, cooling of wafer W1 begins using a cooling plate inside the temperature control section 330. This cooling is performed at a temperature that does not affect the exposure apparatus 200; generally, for example, the target temperature of the air conditioning system of the exposure apparatus 200, which is specified to be in the range of 20~25°C. Normally, when the wafer is moved into the temperature control unit 330, the temperature of the wafer is within ±0.3 [°C] relative to the target temperature, but the temperature control unit 330 adjusts the temperature to within ±10 [mK] of the target temperature.

[0173] Then, when the cooling (temperature adjustment) in the temperature control unit 330 is finished, the wafer W1 is placed in the loading side substrate placement section of the substrate transport section provided between the C / D 300 and the exposure apparatus 200 by means of the C / D internal transport system.

[0174] Within the C / D 300, the same series of resist coating, PB, cooling, and wafer transport operations described above are performed sequentially and repeatedly, placing the wafers sequentially onto the loading-side substrate mounting section. Furthermore, in practice, two or more coating sections and C / D in-cell transport systems are provided within the C / D 300 chamber, thereby enabling parallel processing of multiple wafers and reducing the time required for pre-exposure processing.

[0175] The aforementioned wafer W1, placed on the loading-side substrate mounting section, is transported to a predetermined standby position inside the exposure apparatus 200 by the wafer transport system 270. However, the first wafer W1 is not placed in the standby position, but is directly loaded onto the wafer stage WST by the exposure control device 220. The loading of this wafer is performed by the exposure control device 220, in the same manner as that performed by the aforementioned measuring device 100i, using an up-and-down moving member (not shown) on the wafer stage WST and the wafer transport system 270. After loading, the wafer on the wafer stage WST is subjected to the same search alignment as described above using the alignment detection system AS, and wafer alignment in the EGA manner, for example, setting approximately 3 to 16 irradiation areas as alignment irradiation areas. During wafer alignment in this EGA method, the alignment history data file of the wafer to be aligned and the wafer to be exposed (the target wafer) in the exposure apparatus 200, along with the identification information of the target wafer (such as wafer number, batch number), is provided from the host computer 2000 to the exposure control device 220 of the exposure apparatus 200. The alignment history data obtained by the exposure apparatus 200 from the host computer 2000 includes information on the wafer grids of each wafer measured by the measurement system 500. After a predetermined preparation operation, the exposure control device 220 performs wafer alignment as described later, based on the measurement mode information contained in the acquired alignment history data. Furthermore, the exposure control device 220 and the measurement system control device 530 can also exchange alignment history data without going through the host computer 2000.

[0176] Before explaining wafer alignment in detail, the reasons for using the exposure apparatus 200 to perform EGA wafer alignment by setting approximately 3 to 16 irradiation areas as alignment irradiation areas will be explained.

[0177] The correction amount of the position coordinates of the irradiation area of ​​the wafer W obtained by the measuring device 100i (the coefficients a0, a1, ..., b0, b1, ... in the above formula (1)) is used, for example, for the alignment of the wafer relative to the exposure position when the wafer W is exposed by the exposure device 200. However, by means of the exposure device 200, the wafer W, whose position coordinate correction amount has been measured by the measuring device 100i, is unloaded from the slider 10 of the measuring device 100i as described above, and stored in the FOUP 520. The FOUP 520 is then moved into the C / D 300 by other transport systems such as OHT. Then, after the wafer W is coated with resist by the C / D 300, it is placed on the wafer stage WST of the exposure device 200 for exposure. In this situation, even if the wafer holder WH on the slide 10 and the wafer holder on the wafer stage WST of the exposure apparatus 200 are of the same type, the holding state of the wafer W will still be different due to the individual differences of the wafer holders. Therefore, even if the correction amount of the position coordinates of the irradiation area of ​​the wafer W is finally obtained by using the measuring device 100i (the coefficients a0, a1, ..., b0, b1, ... in the above formula (1)), it is not possible to directly use all of the coefficients a0, a1, ..., b0, b1, ... However, it can be considered that the low-order components (linear components) of the position coordinate correction amount of the irradiation area are affected by the different holding states of the wafer W by each wafer holder, while the high-order components of the second order and above are almost unaffected. The reason is that higher-order components, such as those of order 2 or above, can be considered to be components mainly caused by the deformation of the wafer W during the manufacturing process. Therefore, they can be considered to be components that are unrelated to the wafer's holding state.

[0178] Based on this consideration, the coefficients a3, a4, ..., a9, ... and b3, b4, ..., b9, ... of the higher-order components obtained from the wafer W by the measuring device 100i can also be directly used as coefficients of the higher-order components of the position coordinate correction of the wafer W in the exposure device 200. Therefore, on the wafer stage WST of the exposure device 200, it is sufficient to perform a simple EGA measurement (e.g., measurement of about 3 to 16 wafer marks) to determine the linear components of the position coordinate correction of the wafer W.

[0179] First, the case where the alignment history data file of the target wafer contains information of mode A will be explained. In this case, from the wafer markers contained in the alignment history data whose position information is measured by the measuring device 100i (the marked position information is used in the calculation of the correction amount), a number of wafer markers corresponding to the number of alignment irradiation areas are selected as the detection objects. The alignment detection system AS is used to detect the wafer markers as the detection objects, and based on the detection results and the position of the wafer stage WST during the detection (the measurement information of the interferometer system 218), the position information of each wafer marker as the detection object is obtained. The position information is used to perform EGA calculation to obtain the coefficients of the following formula (2).

[0180] [Equation 2]

[0181] Then, the exposure control device 220 replaces the coefficients (c0, c1, c2, d0, d1, d2) obtained here with the coefficients (a0, a1, a2, b0, b1, b2) contained in the data of the deformation components of the wafer lattice of the target wafer. Using a polynomial represented by the following formula (3) containing the replaced coefficients, which is related to the position coordinates X and Y of each irradiated area in the wafer coordinate system with the center of the wafer as the origin, the correction amount (alignment correction component) dx and dy of the position coordinates of each irradiated area is obtained. Based on the correction amount, the target position (hereinafter referred to as the positioning target position) for the alignment of the wafer lattice with respect to the exposure position (projection position of the tracing pattern) of each irradiated area during exposure is determined. Furthermore, in this embodiment, exposure is performed by scanning exposure rather than static exposure, but for convenience, it is referred to as the positioning target position.

[0182] [Formula 3]

[0183] Furthermore, in the exposure apparatus 200, the rotation of the reference coordinate system (stage coordinate system) and the wafer coordinate system, which are used to determine the movement of the wafer stage WST by search alignment, is also eliminated, so there is no need to distinguish between the reference coordinate system and the wafer coordinate system.

[0184] Next, the case where the alignment history data file of the target wafer contains information in mode B will be explained. In this case, the exposure control device 220 determines the positioning target position of each irradiated area for correction of the wafer lattice according to the same procedure as in the case containing information in mode A. However, at this time, the wafer mark with a good detection signal among the plurality of wafer marks for several irradiated areas and one wafer mark for each of the remaining irradiated areas in the alignment history data is used as the wafer mark whose mark position information is used in the calculation of the correction amount.

[0185] Therefore, in addition to determining the target positions of each irradiation area, the exposure control device 220 selects the number of wafer marks required to determine the shape of the irradiation area from the plurality of wafer marks for the plurality of irradiation areas, and uses the position information (measured values) of these wafer marks to perform a statistical operation (also known as multi-point EGA operation within the irradiation area) by applying the least multiplication method to the model formula [Equation 7] disclosed in U.S. Patent No. 6,876,946, to determine the shape of the irradiation area. Specifically, it determines the wafer rotation (θ), wafer orthogonality error (w), wafer ratio in the x-direction (rx), and wafer ratio in the y-direction (ry) of the 10 parameters in the model formula [Equation 7] disclosed in U.S. Patent No. 6,876,946. Furthermore, the multi-point EGA operation within the irradiation area has been disclosed in detail in the aforementioned U.S. Patent, so a detailed description is omitted.

[0186] Then, the exposure control device 220 controls the position of the wafer stage WST according to the positioning target position, and exposes each irradiation area on the wafer W1 in a step-scan manner. Here, when the shape of the irradiation area is also determined by multi-point EGA measurement within the irradiation area, during the scanning exposure, at least one of the following is adjusted: the relative scanning angle between the tracing plate stage RST and the wafer stage WST; the scanning speed ratio; the relative position of at least one of the tracing plate stage RST and the wafer stage WST relative to the projection optical system; the imaging characteristics (aberrations) of the projection optical system PL; and the wavelength of the illumination light (exposure light) IL. This is to deform the pattern of the tracing plate R by matching the projected image of the projection optical system PL with the determined shape of the irradiation area. Here, the adjustment of the imaging characteristics (aberrations) of the projection optical system PL and the adjustment of the center wavelength of the illumination light IL are performed by the exposure control device 220 through the imaging characteristic correction controller 248.

[0187] Then, before the exposure of the wafer (wafer W1) on the wafer stage WST is completed, the second wafer W2 is placed on the loading side substrate placement section of the substrate transport section by means of the C / D internal transport system, and is transported to a predetermined standby position inside the exposure apparatus 200 by means of the wafer transport system 270, and is in standby position at the standby position.

[0188] Then, when the exposure of wafer W1 is finished, wafer W1 and wafer W2 are exchanged on the wafer stage, and the exchanged wafer W2 is aligned and exposed in the same way as before. Furthermore, before the exposure of the wafer (now wafer W1) on the wafer stage is finished, and before the transfer of wafer W2 to the standby position is completed, the wafer stage holds the exposed wafer in the vicinity of the standby position for standby.

[0189] In parallel with the wafer alignment of the aforementioned swapped wafer W2, the wafer W1 that has completed exposure is transported to the unloading side substrate placement section of the substrate transport section by the wafer transport system 270.

[0190] As described above, the wafers that have completed exposure and are placed on the unloading side substrate placement section of the substrate transport section by the wafer transport system 270 are transported into the baking section by the C / D internal transport system, where PEB is performed by the baking equipment. Multiple wafers can be stored in the baking section at the same time.

[0191] On the other hand, the wafers that have finished PEB are taken out from the baking section by the C / D internal transport system and transported into the developing section, where the developing device begins development.

[0192] Then, when the development of the wafer is completed, the wafer is removed from the developing section by the C / D internal transport system and moved into the FOUP520 used during transport, or a different wafer carrier, and placed in a predetermined storage method. Subsequently, in the C / D 300, for wafers that have completed exposure from the second wafer onwards, the same process as for wafer W1 is repeated for PEB, development, and wafer transport.

[0193] As explained above, the substrate processing system 1000 according to this embodiment can independently perform alignment measurement of the target wafer by means of the measurement device 100i of the measurement system 500, separate from the processing operation of the target wafer by the exposure device 200, which includes the aforementioned simplified EGA measurement and exposure. This achieves efficient processing with almost no decrease in the wafer processing output of the exposure device 200. Furthermore, as a whole, the substrate processing system 1000 can also achieve efficient processing with almost no decrease in wafer processing output by performing alignment and exposure processing of a batch of wafers that have been previously measured and processed by the exposure device 200 by the measurement device 100i of the measurement system 500, and measurement processing of another batch of wafers by the measurement device 100i of the measurement system 500, in parallel. Furthermore, in the measuring device 100i of the measuring system 500, the wafer alignment and exposure of a certain batch of wafers by the exposure device 200 can be performed in parallel with the operation of the exposure device 200 to perform full exposure area EGA on another batch of wafers, with all irradiated areas as sample irradiated areas.

[0194] Furthermore, in the measurement apparatus 100i of the measurement system 500, before performing wafer alignment and exposure on wafers of the same batch for which the preprocessing steps (etching, oxidation / diffusion, film deposition, ion implantation, planarization (CMP), etc.) prior to wafer processing in the exposure apparatus 200 have been completed, a full-area EGA (Enhanced Area Gauge) or a multi-point EGA (Enhanced Area Gauge) including at least a portion of the irradiation area (hereinafter collectively referred to as alignment measurement corresponding to the mode setting) is performed to obtain alignment history data for each wafer obtained through the alignment measurement, including wafer lattice information (e.g., data on the deformation composition of the wafer lattice). The obtained alignment history data for each wafer is stored in an internal memory device of the measurement system control device 530 for each wafer. Therefore, in the exposure apparatus 200, the alignment history data including wafer lattice information for the target wafer obtained using the measurement system control device 530 can be effectively utilized to perform wafer alignment and exposure on the target wafer. In other words, it can be said that in the substrate processing system 1000 of this embodiment, the alignment history data about the target wafer, which includes wafer lattice information (such as data on the deformation components of the wafer lattice), obtained by the pre-measurement processing in the measuring device 100i of the measuring system 500, is essentially forwarded (provided) to the exposure device 200.

[0195] Furthermore, the coefficients of the higher-order components in the model formula obtained by the full irradiation area EGA in the pre-measurement processing of the measuring device 100i can also be directly used in the exposure device 200. Therefore, in the exposure device 200, as long as the alignment measurement of several irradiation areas is performed to align the irradiation areas, the coefficients of the lower-order components of the above model formula can be obtained. By using the coefficients of the lower-order components and the coefficients of the higher-order components obtained by the measuring device 100i, not only can the coefficients of the lower-order components (undetermined coefficients) of the model formula (1) be confirmed, but also the coefficients of the higher-order components (undetermined coefficients) can be confirmed. Using the model formula (1) with the determined coefficients (i.e., the above formula (3)) and the design values ​​(X, Y) of the arrangement of multiple irradiation areas on the wafer, the correction amount of the position of each irradiation area in the design can be obtained. In this way, the correction amount with the same good accuracy as when the coefficients of the lower-order and higher-order components of the model formula (1) are obtained by the exposure device 200. Furthermore, based on the correction amount and the design value of the arrangement of the plurality of irradiation areas on the wafer, the positioning target position of each irradiation area during exposure can be calculated. Therefore, by controlling the position of the wafer stage (WST) according to the target position, each irradiation area can be accurately aligned with the exposure position (the projection position of the tracing pattern). In this way, the output of the exposure apparatus 200 is not reduced, and the superposition accuracy of the image of the tracing pattern during exposure and the pattern formed in each irradiation area on the wafer is improved.

[0196] Furthermore, according to the measuring apparatus 100i of this embodiment, the control device 60i controls the movement of the slider 10 by the drive system 20 while using the first position measuring system 30 and the second position measuring system 50 to acquire position information of the slider 10 relative to the fixed plate 12 and relative position information of the mark detection system MDS to the fixed plate 12. The mark detection system MDS is then used to determine the position information of the plurality of marks formed on the wafer W. Therefore, according to the measuring apparatus 100i, the position information of the plurality of marks formed on the wafer W can be determined with good accuracy.

[0197] Furthermore, according to the measuring device 100i of this embodiment, the control device 60i frequently acquires the measurement information (relative position information of the fixed plate 12 and the mark detection system MDS) of the second position measuring system 50, and controls the position of the fixed plate 12 in the 6-degree-of-freedom direction in real time through the three vibration damping devices 14 (actuators), so that the positional relationship between the detection center of the mark detection system MDS and the measurement point of the first position measuring system that detects the position information of the slider 10 relative to the fixed plate 12 in the 6-degree-of-freedom direction is maintained at the desired relationship at the nm level. Furthermore, while controlling the drive system 20 to drive the slider 10, the control device 60i acquires measurement information from the first position measurement system 30 (position information of the slider 10 relative to the fixed plate 12) and the second position measurement system 50 (relative position information of the fixed plate 12 and the mark detection system MDS). Based on the detection signal obtained when the mark detection system MDS detects the marks formed on the wafer W, the measurement information obtained from the first position measurement system 30 when the mark detection system MDS detects the marks formed on the wafer W, and the measurement information obtained from the second position measurement system 50 when the mark detection system MDS detects the marks formed on the wafer W, the position information of a plurality of wafer marks is calculated. Therefore, according to the measurement device 100i, the position information of a plurality of marks formed on the wafer W can be calculated with good accuracy.

[0198] Furthermore, for example, when EGA calculations are performed without using the measured mark position information, but rather when the position control of the wafer W (wafer stage WST) during exposure is based on the measured mark position information, the measurement information from the second position measurement system 50 may not be used for calculating the mark position information. However, in this case, the measurement information from the second position measurement system 50 obtained when detecting the marks formed on the wafer W using the mark detection system MDS can be used as a compensation value, for example, to correct the information used to move the wafer W (wafer stage WST), such as the positioning target value of the wafer W (wafer stage WST). Alternatively, the movement of the scribe plate R (scribe plate stage RST) during exposure can be controlled by considering the aforementioned compensation value.

[0199] Furthermore, according to the measuring apparatus 100i of this embodiment, the first position measuring system 30, which measures the position information of the slider 10 holding the wafer W in six degrees of freedom, utilizes a mark detection system MDS to detect at least the wafer marks on the wafer W. Therefore, within the range of movement of the slider 10, the self-reading head 32 can continuously illuminate the grating RG1 with a measurement beam. Thus, the first position measuring system 30 can continuously measure the position information across the entire range in the XY plane where the slider 10 moves to detect the marks. Therefore, for example, during the manufacturing stage of the measuring device 100i (including the startup stage of the device in the semiconductor manufacturing plant), the origin of the orthogonal coordinate system (reference coordinate system) defined by the length measuring axis of the first position measuring system 30 is found. This allows for the management of the absolute position of the slider 10 on the reference coordinate system, and even the absolute position of the marks (not limited to search marks and wafer marks, but also including other marks such as overlay measurement marks (alignment marks)) held on the wafer W on the slider 10, determined based on the position information of the slider 10 and the detection results of the mark detection system MDS. Furthermore, in this specification, "absolute position" refers to the coordinate position on the reference coordinate system.

[0200] As can be clearly understood from the description so far, the substrate processing system 1000 of this embodiment includes a measurement system 500. Therefore, even when the exposure apparatus 200 only has the function of performing a simple EGA measurement (e.g., using an alignment detection system AS to acquire position information of approximately 3 to 16 wafer markers) to determine the linear component of the wafer position coordinate correction amount within a predetermined time (the time allowed to maintain the required high output), the wafer lattice deformation can be determined with high accuracy using the low-order component of the wafer lattice deformation determined by the simple EGA measurement and the high-order component of the wafer lattice deformation determined in advance by the measurement system 500, such as by a full-point EGA. Therefore, the lattice correction function of the exposure apparatus 200 can be substantially improved by the measurement system 500. Therefore, compared to the most advanced exposure equipment without lattice correction function, it can perform high-precision exposure of wafers with high throughput or without reducing throughput.

[0201] Furthermore, in the substrate processing system 1000 of the above embodiment, the measurement device 100i, C / D 300, and exposure device 200 are described as having barcode readers. However, a wireless IC tag (RFID) tag writing / reading device can also be used instead of a barcode reader. In this case, since RFID tags are installed on each wafer, the measurement device 100i uses the writing / reading device to write the aforementioned alignment history data to the RFID tag for each wafer. Other devices, such as the exposure device 200, use the writing / reading device to read the alignment history data from the RFID tag of the target wafer. In this way, the feedforward of the alignment history data of the target wafer can be easily realized.

[0202] Furthermore, in the substrate processing system 1000 of the above embodiment, the coefficients of the lower-order components of the above model formula (order 1 or less) are calculated by the exposure apparatus 200, and the coefficients of these lower-order components are used together with the coefficients of the higher-order components of the above model formula (order 2 or more) obtained by the measuring apparatus 100i. However, this is not a limitation. For example, the coefficients of the lower-order components of the above model formula can also be calculated based on the detection results of the alignment marks within the exposure apparatus 200, and the coefficients of these lower-order components can be used together with the coefficients of the higher-order components of the above model formula (order 3 or more) obtained by the measuring apparatus 100i. Alternatively, the coefficients of the lower-order components of the above model formula can also be calculated based on the detection results of the alignment marks within the exposure apparatus 200, and the coefficients of these lower-order components can be used together with the coefficients of the higher-order components of the above model formula (order 4 or more) obtained by the measuring apparatus 100i. That is, the coefficients of the components of the above model formula below the (N-1)th order (N is an integer greater than 2) can also be obtained based on the detection results of the alignment marks in the exposure device 200, and the coefficients of the components below the (N-1)th order and the coefficients of the higher-order components of the above model formula above the Nth order obtained by the measuring device 100i can be used.

[0203] Furthermore, in the above-described embodiment, the measuring device 100i also calculates the coefficients a3, a4, a5... and b3, b4, b5... of the higher-order components of order 2 and above, and the coefficients a0, a1, a2, b0, b1, b2 of the lower-order components of order 1 and below. The model formula (1) expresses the relationship between the design position coordinates X and Y of each irradiation area on the wafer coordinate system (consistent with the reference coordinate system) and the position coordinate correction amount (alignment correction component) dx and dy of the irradiation area. However, since the coefficients of the lower-order components are calculated using the exposure device 200, it is not necessary to calculate the coefficients of the lower-order components in the measuring device 100i.

[0204] Furthermore, in the above embodiment, when the measurement device 100i is set to mode B and the position information of multiple wafer marks for several irradiated areas on the wafer is measured, the exposure device 200 calculates the wafer rotation (θ), wafer orthogonality error (w), and wafer ratio in the x-direction (rx) and y-direction (ry) by performing multi-point EGA calculations within the irradiated area, thereby determining the shape of the irradiated area. However, it is not limited to this. For example, even when the measurement device 100i is set to mode A and the position information of one wafer mark for each of all irradiated areas on the wafer is measured, the exposure device 200 can still infer the deformation of the irradiated area (shape change of the irradiated area). This will be explained below.

[0205] The wafer lattice on wafer W will be deformed due to the manufacturing process, and each irradiated area will also be slightly deformed due to the process, but it is assumed that the deformation will follow the deformation of the wafer lattice. The deformation components of the wafer lattice can be divided into four independent deformation components as shown below, and each deformation component will cause the deformation of the irradiated area as shown below. (1) The variation of dx with respect to the X-axis direction Magnification change in the X-axis direction (2) The variation of dx with respect to the Y-axis direction Rotation relative to the Y-axis (3) The variation of dy with respect to the X-axis direction Y-axis magnification change (4) The variation of dy with respect to the Y-axis direction Rotation relative to the X-axis

[0206] Therefore, in this embodiment, the variation components of (1) to (4) above are calculated, and the deformation of the irradiated area on the wafer W is inferred based on the variation components.

[0207] In addition, there are roughly two methods for inferring the deformation of the irradiated area, as shown below. (A) The irradiated area is deformed by taking the partial derivatives of X and Y with respect to the coefficients (indeterminate coefficients) according to the formula (3) after the coefficients (indeterminate coefficients) are determined. (B) Approximate the wafer lattice to a first-order model formula, and deform the irradiation area according to the coefficients of the model formula. Here, for the wafer lattice, the design position coordinates X and Y of each irradiation area can be substituted into the formula (3) after the coefficients (undetermined coefficients) are determined to obtain the correction amount of the self-design value of the arrangement of multiple irradiation areas on the wafer (the correction amount dx, dy of the position coordinates of the irradiation area), which is the deformation component of the wafer lattice, and the correction amount and the design value of the position coordinates of the irradiation area are used to calculate the deformation component.

[0208] The method of correcting the shape of the irradiated area using the inference method of (A) will be called higher-order partial differential correction, and the method of correcting the shape of the irradiated area using the inference method of (B) will be called first-order approximate correction. Even with the same wafer lattice, the deformation state of the irradiated area will be different when using method (A) and when using method (B).

[0209] Figures 13(A) and 13(B) illustrate an example of the difference between higher-order partial differential correction and first-order approximation correction. For simplicity, the Y-component in the wafer lattice is assumed to be dy = b6 × 3. Figure 13(A) shows three irradiation regions corrected by higher-order partial differential correction. In the case of higher-order partial differential correction, the rotation of each irradiation region relative to the Y-axis follows the partial derivative dy = b6 × 3, i.e., dy' = 3b6 × 2. In this case, the deformation of the central irradiation region is 0. On the other hand, Figure 13(B) shows three irradiation regions corrected by first-order approximation correction. In first-order approximation correction, EGA alignment is performed again using a first-order model formula, and the shape of the irradiation region is corrected using the first-order coefficient related to the rotation relative to the Y-axis in the model formula. When this approximate correction is made, as shown in Figure 13(B), the central irradiation area in the three irradiation areas also undergoes one deformation. Overall, the deformation of each irradiation area becomes the same.

[0210] As shown in Figures 13(A) and 13(B), in higher-order partial differential correction, the deformation of the irradiated area is localized along the wafer lattice surrounding the irradiated area. In contrast, in first-order approximation correction, the deformation of all irradiated areas of wafer W becomes the same. For example, the choice of method can be specified based on the exposure formula or appropriately selected by the user according to the required specifications of the semiconductor being manufactured. When inferring the deformation of the irradiated area, similarly as described above, the exposure control device 220 adjusts at least one of the following during scanning exposure: the relative scanning angle between the tracing plate stage RST and the wafer stage WST, the scanning speed ratio, the relative position of at least one of the tracing plate stage RST and the wafer stage WST relative to the projection optical system, the imaging characteristics (aberrations) of the projection optical system PL, and the wavelength of the illumination light (exposure light) IL, so that the pattern of the tracing plate R is deformed by the projection image of the projection optical system PL in accordance with the obtained shape of the irradiated area (the shape of the irradiated area obtained by inferring the deformation of the irradiated area).

[0211] Furthermore, in the substrate processing system 1000 of this embodiment, when the measurement unit 40 of the measurement device 100i is equipped with the aforementioned multi-point focal position detection system, wafer alignment measurement and wafer W flatness measurement (also known as focus mapping) can also be performed by the measurement device 100i. At this time, by using the result of the flatness measurement, the focus and leveling control of the wafer W during exposure can be achieved without the need for flatness measurement by the exposure device 200.

[0212] Alternatively, at least one of the measuring devices 1001, 1002, and 1003 of the measuring system 500 may be configured as a measuring device with a different function from other measuring devices. For example, one measuring device may be configured as a measuring device with a multi-point focal position detection system for measuring the unevenness (flatness) of the wafer surface, or it may be configured as a wafer shape determination device. Furthermore, the measuring system 500 may also have two or more measuring devices.

[0213] Furthermore, in the above embodiment, the object is set as a 300 mm wafer, but it is not limited to this; it can also be a 450 mm wafer with a diameter of 450 mm. Since wafer alignment can be performed independently of the exposure apparatus 200 by the measurement apparatus 100i, even with a 450 mm wafer, the output of the exposure process will not decrease, and measurements such as full-point EGA can be performed.

[0214] Furthermore, in the above embodiment, for the sake of simplicity, the measurement mode of the measuring device 100i is set to either mode A or mode B, but mode B may not be set. Also, it is possible to set: mode C, which detects two or more wafer marks for all irradiated areas on all wafers in the batch; and mode D, which detects two or more wafer marks for a portion of the irradiated areas, such as a predetermined irradiated area located at the wafer periphery, and detects one wafer mark for each of the remaining irradiated areas. Furthermore, mode E can also be set, that is, based on the detection results of wafer marks on the initial predetermined number of wafers in the batch, any one of mode A, mode C, or mode D is selected for the remaining wafers in the batch.

[0215] Furthermore, as a measurement mode of the measuring device 100i, it is also possible to measure one or more wafer marks in a portion of the irradiated area, such as 90% or 80% of the irradiated area, for all wafers in a batch, or to measure one or more wafer marks in an irradiated area located in the center of the wafer, spaced one apart.

[0216] Furthermore, in the measurement device 100i of the above embodiment, the cases in which the X-axis direction and the Y-axis direction of the gratings RG1, RG2a, and RG2b are respectively used as periodic directions are explained, but it is not limited to this. As long as the grid part (2D grating) of each of the first position measurement system 30 and the second position measurement system 50 uses the two directions that intersect each other in the XY plane as periodic directions.

[0217] Furthermore, the configuration of the measuring device 100i described in the above embodiment is merely one example. For instance, the measuring device only needs to be configured to have a stage (slider 10) that can move relative to the base member (plate 12), and to measure the position information of a plurality of marks held on the substrate (wafer) on the stage. Therefore, the measuring device does not necessarily need to have, for example, a first position measuring system 30 and a second position measuring system 50.

[0218] Furthermore, the configuration of the read head 32 and the arrangement of the detection points in the first position measurement system 30 described in the above embodiment are, of course, only one example. For instance, the positions of the detection points of the marker detection system MDS and the detection center of the read head 32 may not be consistent in at least one of the X-axis and Y-axis directions. Also, the arrangement of the read head and the grating RG1 (grid section) of the first position measurement system 30 may be reversed. That is, the read head may be located on the slider 10, and the grid section on the fixed plate 12. Furthermore, the first position measurement system 30 does not necessarily need to have an encoder system 33 and a laser interferometer system 35; it may be constructed solely by an encoder system. The first position measurement system may also be constructed by an encoder system in which the read head illuminates a beam of light onto the grating RG1 of the slider 10 and receives the returned beam (diffracted beam) from the grating to measure the position information of the slider 10 relative to the fixed plate 12 in six degrees of freedom directions. In this case, the configuration of the read head is not particularly limited. For example, one pair of XZ read heads can be provided that illuminate two points on the grating RG1 at the same distance in the X-axis direction relative to a predetermined point, and one pair of YZ read heads can be provided that illuminate two points on the grating RG1 at the same distance in the Y-axis direction relative to a predetermined point. Alternatively, one pair of 3D read heads can be provided that illuminate two points on the grating RG1 at the same distance in the X-axis direction, and one XZ or YZ read head can be provided that illuminates a point on the Y-axis direction at a position different from the two points mentioned above. The first position measurement system 30 does not necessarily need to be able to measure the position information of the slider 10 relative to the fixed plate 12 in the six degrees of freedom directions; for example, it may only be able to measure the position information in the X, Y, and θz directions. Furthermore, the first position measurement system for measuring the position information of the slider 10 relative to the fixed plate 12 can also be configured between the fixed plate 12 and the slider 10. Furthermore, the first measuring system used to measure the absolute position of the slider 10 may not necessarily have an encoder system that illuminates the grating RG1 of the slider 10 from the aforementioned reading head. It may also include an interferometer system or other measuring device that measures the position information of the slider 10 relative to the fixed plate 12 in a 6-degree-of-freedom direction or in a 3-degree-of-freedom direction in the horizontal plane.

[0219] Similarly, the configuration of the second position measurement system 50 described in the above embodiment is merely one example. For instance, the read heads 52A and 52B can be fixed to the side of the fixed plate 12, and the scales 54A and 54B can be integrated with the mark detection system MDS. Furthermore, the example shown is of the second position measurement system 50 having a pair of read heads 52A and 52B, but it is not limited to this; the second position measurement system 50 may also have only one read head, or it may have three or more read heads. In short, it is preferable that the second position measurement system 50 can measure the positional relationship between the fixed plate 12 and the mark detection system MDS in six degrees of freedom directions. However, the second position measurement system 50 does not necessarily need to be able to measure all positional relationships in the six degrees of freedom directions.

[0220] Furthermore, in the above embodiment, the following situation was described: the slider 10 is suspended and supported on the fixed plate 12 by a plurality of air bearings 18, and constitutes a drive system 20. This drive system 20 includes a first drive device 20A that drives the slider 10 along the X-axis direction, and a second drive device 20B that is integral with the first drive device 20A and drives the slider 10 along the Y-axis direction, and drives the slider 10 in a non-contact state relative to the fixed plate 12. However, it is not limited to this; as the drive system 20, a drive system that drives the slider 10 along six degrees of freedom directions on the fixed plate 12 can also be used. For example, this drive system can also be constructed using a magnetically levitated planar motor. In this case, the air bearings 18 are not required. Furthermore, the measuring device 100i can also have a drive system for driving the fixed plate 12 independently of the vibration damping device 14.

[0221] Furthermore, in the above embodiment, the measurement system 500 includes an EFEM system as a carrier system 510, but it can also replace the EFEM system by providing a carrier storage device that can store a plurality of (e.g., 3) carriers (FOUPs, etc.) along the Y-axis direction. In this case, the measurement system 500 may also include: a plurality of loading ports disposed adjacent to the plurality of measurement devices 100i respectively, and a carrier transport device for transporting the carriers (FOUPs, etc.) between the carrier storage device and the mounting parts of the plurality of loading ports.

[0222] Implementation Form 2 Next, the second embodiment will be described. In this embodiment, the wafer lattice variation management and stacking measurement performed by the measurement system 500 of the substrate processing system 1000 will be described.

[0223] As described above, the measuring device 100i includes a first position measuring system 30. Therefore, by finding the origin of the orthogonal coordinate system (reference coordinate system) defined by the length measuring axis of the first position measuring system 30, the absolute position of the slider 10 can be managed on the reference coordinate system. Furthermore, the absolute position of wafer marks, such as overlay measurement marks (alignment marks), held on the wafer W on the slider 10 and determined based on the position information of the slider 10 and the detection results of the mark detection system MDS, can also be managed. That is, the measuring device 100i can also function as an overlay measuring device 400.

[0224] Change Management in Wafer Lattice Next, we will take the case where the wafer lattice management method, which originates from the exposure apparatus, is applied to the substrate processing system 1000 as an example. Figure 14 shows the processing flow of the wafer lattice management method in this case in a simplified manner.

[0225] First, in step S202, the exposure apparatus 200 exposes a batch of bare wafers (referred to as wafer W0) using a product marker sheet R in a step-scan manner. Here, it is assumed that on the marker sheet R, markings (which become wafer marks when transferred to the wafer) are formed on its patterned surface along with a rectangular patterned area in the surrounding area or within the patterned area (when multiple wafers are taken from one irradiation area). Here, wafer W0 is an unexposed wafer, with resist coated on its surface using C / D 300. Therefore, during the exposure of wafer W0, alignment is not performed; instead, based on design values, the exposure control device 220 drives and controls the marker sheet stage RST and the wafer stage WST. Through the exposure in step S202, a matrix-arranged rectangular pattern area (e.g., 98) and a transfer image (latent image) corresponding to each irradiated area are formed on the resist layer on the surface of the wafer WO. The positional relationship between the latent image and each irradiated area is known in the design.

[0226] Subsequently, in step S204, the exposed wafer W0 is unloaded from the wafer stage WST and moved into the developing section of the C / D 300. Specifically, the wafer W0 is transported by the wafer transport system 270 and placed in the unloading side substrate placement section of the substrate transport section provided between the C / D 300 and the exposure apparatus 200. Then, the wafer W0 is moved into the developing section of the C / D 300 by the C / D internal transport system.

[0227] Subsequently, in step S206, the wafer W0 is developed by the developing apparatus of the developing section of the C / D 300. After development, one (e.g., 98) rectangular irradiation areas arranged in a matrix are formed on the wafer W0, and a resist image (hereinafter appropriately referred to as wafer mark) corresponding to each irradiation area is formed, with the positional relationship of each irradiation area known in the design.

[0228] Subsequently, in step S208, the FOUP containing a plurality of wafers, including the developed wafer W0, is removed from the C / D 300 and placed on the loading port 514 of the measurement system 500 using the aforementioned OHT or similar means. That is, the wafer W0 removed from the FOUP from the C / D 300 is transported to the measurement system 500 before the processing steps performed after the development process (etching process, or film deposition process after etching process (including at least one of sputtering process, CVD process, and thermal oxidation process)). The wafer W0 contained in the FOUP is removed from the FOUP using a robot 516 or similar means and loaded onto the slider 10 of the measurement device 100i using a transport system 521 or similar means.

[0229] Furthermore, in the following description, one of the multiple wafers housed in the FOUP will be referred to as wafer W0, but the same process can be applied to all or part of the multiple wafers housed in the FOUP.

[0230] Subsequently, in step S210, the measuring device 100i performs the aforementioned full-area 1-point measurement on the developed wafer W0 to determine the absolute position coordinates of each wafer mark. That is, the control device 60i uses the first position measurement system 30 (and the second position measurement system 50) to measure the position information of the slider 10, and uses the mark detection system MDS to detect the I wafer marks corresponding to each of the I (e.g., 98) irradiation areas. Based on the detection results of each of the I wafer marks and the absolute position coordinates (X, Y) of the slider 10 at the time of detection of each of the I wafer marks, the absolute position coordinates (X, Y) of the I wafer marks corresponding to each of the I irradiation areas on the wafer W0 are determined. At this time, the control device 60i calculates the absolute position coordinates (X, Y) of I wafer marks based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30, using the Abbe errors in the X and Y directions of the first position measurement system 30 and the measurement values ​​in the X and Y directions of the second position measurement system 50 as compensation values. Furthermore, in step 210, it is ideal to perform a one-point measurement of the entire irradiation area, but it is also possible to omit the detection of wafer marks in a portion of the irradiation area.

[0231] Subsequently, in step S212, the control device 60i uses the obtained absolute position coordinates of the I marks to determine the change information of the arrangement (wafer grid) of the I irradiation areas on the wafer W0. For example, based on the known positional relationship between the wafer marks and the center of the irradiation area, the control device 60i determines the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiation areas from the absolute position coordinates of the I wafer marks, and based on the difference between the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiation areas and the design values ​​of the position coordinates (X, Y) of each irradiation area, it uses statistical operations such as the least squares method to determine the coefficients a0, a1, ..., b0, b1, ... of the aforementioned equation (1). Here, the obtained coefficients a0, a1, ..., b0, b1, ... are substituted into equation (1), and the equation (1) after the coefficients are determined is used as the change information of the wafer lattice and stored in the memory inside the measurement system 500 (e.g., the memory device of the control device 60i, or the memory device inside the measurement system control device 530) or in an external memory device.

[0232] Alternatively, the control device 60i can also, based on the known positional relationship between the wafer markers and the center of the irradiation area, calculate the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiation areas from the absolute position coordinates of the I wafer markers, and create a mapping, and use the mapping as the change information of the wafer lattice. The mapping includes the difference between the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiation areas and the design values ​​of the position coordinates (X, Y) of each irradiation area.

[0233] Alternatively, the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiated areas can be used as information on the changes in the wafer lattice.

[0234] This allows for the determination and management of the variation in the self-designed value of the wafer lattice at any time.

[0235] The next step, S214, can be performed as needed. In step S214, the control device 60i compares the variation information of the self-designed value of the wafer lattice obtained in step S210 with the variation information of the reference wafer lattice stored in memory (or the memory device of the measurement system control device 530) to calculate the difference. For example, the variation amount of the wafer lattice is calculated based on the variation of the reference wafer lattice. Through the processing of step S214, errors in the arrangement of irradiated areas caused by errors in the stage lattice between different exposure devices, or errors in the arrangement of irradiated areas caused by errors in the stage lattice at different times within the same exposure device, can be managed.

[0236] In the former case, before the processing in step S214, a scanning stepper different from the exposure device 200 is used to expose bare wafers from different batches than wafer W0 using a caliper R, in the same way as in step S202. For the wafers that have been exposed, the same processing as in steps S204 to S212 is performed to obtain the change information of the wafer lattice as a reference and store it in the memory (or the memory device of the measurement system control device 530).

[0237] In the latter case, before the processing in step S214, other wafers contained in the same batch as wafer W0 or in different batches of wafer W0 but other than wafer W0 are exposed using the exposure apparatus 200 with the datum plate R, in the same manner as in step S202. The wafers are then processed in the same way as in steps S203 to S212, thereby obtaining the change information of the wafer lattice as a reference and storing it in the memory (or the memory device of the measurement system control device 530).

[0238] Furthermore, the measuring device 100i used to acquire wafer lattice variation information of wafer W0 can be the same as or different from the measuring device 100i used to acquire wafer lattice variation information as a reference.

[0239] As can be clearly seen from the above description, the management method of this embodiment can manage the changes in the wafer lattice caused by the device without using a reference wafer. Therefore, the following problems can be avoided when using a reference wafer.

[0240] In other words, the use of reference wafers involves using them on multiple exposure units, leading to competition between them. Reference wafers are typically manufactured in multiples, not just one, so individual differences between them must be ensured. Furthermore, reference wafers can sometimes be damaged or degraded during use. In wafer lattice management methods using reference wafers, a resist is coated onto the surface of the reference wafer and exposed. After the necessary processing is complete, the resist must be removed and the reference wafer cleaned. Repeating this process can sometimes cause surface damage. Additionally, traces of the clamping components (pin clamps, etc.) found in wafer holders can form on the back side of the reference wafer, causing adhesion deformation and thus wafer lattice deformation.

[0241] On the other hand, by not using a reference wafer, there are advantages as described below. a. Measurement (correction) can be performed when there is no need to pay attention to the empty space or serial number of the reference wafer, and the changes in the wafer lattice are to be measured (corrected). b. Because bare wafers can be used instead of reference wafers, quality management can be easily implemented. c. Wafer lattice management can be achieved using product illumination area mapping and product marker pieces. That is, wafer lattice management can be performed using overlay measurement marks or alignment marks attached to the product marker pieces. As a result, dedicated marker pieces for quality management are not required. Furthermore, quality management can be performed using product illumination area mapping itself. Therefore, not only can the variation in wafer lattice caused by location-dependent errors be measured, but also the variation caused by scanning speed or acceleration, and all other error factors generated during product exposure. Therefore, by making corrections based on these measurement results, all compromises arising from lattice management using reference wafers, as described below, can be eliminated. a. The so-called grid error is dependent on coordinates. If the locations are the same, the error will be the same. If the measurement mark is located near a point where grid error correction has been applied, the error is considered to be small. b. Errors in scanning speed or scanning acceleration will not cause grid errors. Even if grid errors are caused, they will not change with each scan, so one adjustment is sufficient and no regular maintenance is required.

[0242] Furthermore, the wafer lattice information of wafer W0 obtained in step 212 can be provided (feedback) to the exposure apparatus 200. After a batch containing wafer W0, when exposing bare wafers in different batches using the datum plate R in the exposure apparatus 200, the movement control of the stage WST of the exposure apparatus 200 can be performed to minimize the variation (deviation from the design value) of the first-layer wafer lattice. That is, the wafer lattice information of wafer W0 obtained in step 212 can be used to determine the positioning target position when exposing each irradiation area of ​​bare wafers in other batches.

[0243] Furthermore, in step 210, if the absolute position coordinates of two or more wafer markers can be obtained for all irradiated areas on wafer W0, and information related to the shape and size of each irradiated area can be obtained, this information can also be provided (feedback) to the exposure apparatus 200 to control the imaging characteristic correction controller 248, or to control at least one of the speed and direction of the tracing stage RST, so that the shape and size of each irradiated area become the desired state.

[0244] Furthermore, in order to perform the second layer exposure process (setting the first layer as the layer above the lower layer), the wafer lattice change information of wafer W0 can be obtained before wafer W0 is transferred to C / D device 300 (or other C / D device) after undergoing various processes (including etching and film deposition). At this time, as described in the first embodiment, the alignment history data of wafer W0 containing the obtained wafer lattice change information can be provided (feedforward) to the exposure apparatus 200 or other exposure apparatus for performing the second layer exposure process, or the wafer lattice change information of wafer W0 can be provided (feedback) to the exposure apparatus 200 for use after the batch containing wafer W0, when bare wafers contained in different batches of wafer W0 are exposed by the exposure apparatus 200 using the line guide plate R.

[0245] Overlay Measurement Next, we will take the case where the overlay measurement method using the measuring device is applied to the substrate processing system 1000 as an example for explanation. Figure 15 schematically shows the processing flow of the overlay measurement method in this case.

[0246] First, in step S302, wafers (denoted as wafer W11) contained in a batch are transferred to C / D 300. In the coating section of C / D 300, resist is applied to wafer W11 that has undergone first-layer (lower-layer) exposure by exposure apparatus 200 or an exposure apparatus different from exposure apparatus 200, such as a scanner or a stepper. On wafer W11 before resist coating, by exposure of the lower layer, along with a plurality of irradiation areas, such as I (I is, for example, 98), wafer marks and first marks for measuring overlay deviation (more precisely, resist images of the first marks (also appropriately called first mark images)) are formed corresponding to each irradiation area, with the designed positional relationship to the irradiation area known. At this time, the designed positional relationship of each of the I first mark images is also known.

[0247] Subsequently, in step S304, the wafer W11 coated with resist undergoes the same predetermined processing as the aforementioned wafer W1 and is loaded onto the wafer stage WST of the exposure apparatus 200. Specifically, the wafer W11 is heated in the baking section (PB) and temperature-controlled in the temperature-controlled section 330 before being loaded onto the wafer stage WST.

[0248] Subsequently, in step S306, the exposure control device 220 of the exposure device 200 performs the same search alignment as described above on the wafer W11 on the wafer stage WST using the alignment detection system AS, and performs wafer alignment in the EGA mode, using, for example, about 3 to 16 irradiation areas as alignment irradiation areas.

[0249] Furthermore, prior to step S302, as described in the first embodiment, the wafer lattice information of the wafer W11 is obtained using the measuring device 100i of the measuring system 500 and provided to the exposure control device 220 of the exposure apparatus 200.

[0250] Subsequently, in step S308, the exposure control device 220, based on the wafer alignment result, calculates the correction amount (alignment correction component) dx, dy of the position coordinates of each irradiation area as expressed in the aforementioned formula (3), and based on the correction amount, determines the positioning target position used to correct the wafer lattice and the exposure of each irradiation area.

[0251] Furthermore, prior to step 302, it is not necessary to use the measuring device 100i of the measuring system 500 to obtain the wafer grid information of the wafer W11. Instead, the positioning target position during exposure of each irradiation area can be determined solely based on the results of wafer alignment using the alignment detection system AS, which uses approximately 3 to 16 irradiation areas as alignment irradiation areas in the EGA method.

[0252] Subsequently, in step S310, the exposure apparatus 200 performs a second layer (setting the first layer as the layer above the lower layer) exposure on each irradiation area of ​​the wafer W11 using a step-scan method while controlling the position of the wafer stage WST according to the positioning target position. At this time, the exposure apparatus 200 uses a marker sheet (referred to as marker sheet R11 for convenience) with a second mark formed corresponding to the first mark image on the wafer W11 for exposure. Therefore, through the exposure of the second layer, the pattern area of ​​the marker sheet R11 is transferred to the I irradiation areas on the wafer W11 in superimposed form, and a transfer image of I second marks is formed with a positional relationship corresponding to the positional relationship of the I first marks.

[0253] Subsequently, in step S312, the wafer W11, whose second layer exposure has been completed, undergoes the same processing as the wafer W1, which has completed exposure, and is then moved into the developing section of the C / D 300. Specifically, the wafer W11 is transported to the unloading side substrate placement section of the substrate transport section by the wafer transport system 270, and then moved from the unloading side substrate placement section into the baking section of the C / D 300 by the C / D internal transport system, where PEB is performed by the baking apparatus. The wafer W11, after PEB is completed, is removed from the baking section by the C / D internal transport system and moved into the developing section.

[0254] Subsequently, in step S314, the wafer W11 on which a plurality of second marks have been transferred is developed using the developing apparatus within the developing section. Through this development, a set of I first mark images and corresponding second mark images is formed on the wafer W11, together with I irradiation areas, in a predetermined positional relationship, thereby becoming a substrate for overlay measurement. That is, a substrate (overlay measurement object substrate) for overlay measurement is thus fabricated. Here, the set of first mark images and corresponding second mark images can, for example, be a resist image with frame-to-frame markings, which includes an outer frame marking and an inner frame marking disposed within it.

[0255] Subsequently, in step S316, a FOUP containing a plurality of wafers from a certain batch, including the developed wafer W11 (as a substrate for the stacked measurement), is removed from the C / D 300 and placed on the loading port 514 of the measurement system 500 using the aforementioned OHT or similar equipment. That is, the wafer W11 removed from the C / D 300 is transferred to the measurement system 500 before the processing steps performed after the development process (etching process, or film deposition process after etching process (including at least one of sputtering process, CVD process, and thermal oxidation process)). The wafer W11 contained in the FOUP is removed from the FOUP using a robot 516 or similar equipment and transferred to the measurement apparatus 100i using a transfer system 521 or similar equipment.

[0256] Furthermore, in the following description, one of the multiple wafers housed in the FOUP will be referred to as wafer W11, but the same treatment can be applied to all or part of the multiple wafers housed in the FOUP.

[0257] Subsequently, in step S318, the developed wafer W11 (overlay measurement target substrate) is loaded onto the slider 10 using the measuring device 100i following the aforementioned process. The absolute position coordinates of each of the I sets of first and second marker images in the XY plane are determined in the following manner. That is, while the control device 60i uses the first position measurement system 30 (and the second position measurement system 50) to measure the position information of the slider 10, the marker detection system MDS detects each of the I first marker images and I second marker images on the wafer W11. Based on the detection results of each of the I first and I second marker images and the absolute position coordinates (X, Y) of the slider 10 at the time of detection of each marker image, the absolute position coordinates of each of the I first and I second marker images on the wafer W11 in the XY plane are determined. At this time, the control device 60i calculates the absolute position coordinates of each of the I first marker images and I second marker images in the XY plane based on the measurement values ​​of the slider 10 in the θx and θy directions measured by the first position measurement system 30, using the Abbe error in the X and Y directions of the first position measurement system 30 and the measurement values ​​in the X and Y directions of the second position measurement system 50 as compensation values.

[0258] Furthermore, in step S318, the absolute position coordinates of the K fewer first marker images and the K fewer second marker images can also be obtained.

[0259] Subsequently, in step S320, the control device 60i calculates the superposition error (superposition deviation) between the first and second layers based on the absolute position coordinates of the first and second marker images that are grouped together.

[0260] Subsequently, in step S322, the control device 60i, based on the absolute position coordinates of I first marker images and I second marker images, determines, for example, whether the overlay error is mainly caused by the exposure of the first layer or the exposure of the second layer. That is, the control device 60i calculates the deviation of the absolute position coordinates of the first marker image from the designed position coordinates (ΔX1i, ΔY1i) (i=1~1) and the deviation of the absolute position coordinates of the second marker image from the designed position coordinates (ΔX2i, ΔY2i) (i=1~1), and calculates the sums ΣX1i, ΣX2i, ΣY1i, and ΣY2i for ΔX1i, ΔX2i, ΔY1i, and ΔY2i respectively. Furthermore, when ΣX1i>ΣX2i and ΣY1i>ΣY2i, the control device 60i determines that the overlay error is mainly caused by the exposure of the first layer in both the X-axis and Y-axis directions. When ΣX1i<ΣX2i and ΣY1i<ΣY2i, the control device 60i determines that the overlay error is mainly caused by the exposure of the second layer in both the X-axis and Y-axis directions. Also, when ΣX1i>ΣX2i and ΣY1i<ΣY2i, the control device 60i determines that the overlay error is mainly caused by the exposure of the first layer in the X-axis direction and by the exposure of the second layer in the Y-axis direction. When ΣX1i<ΣX2i and ΣY1i>ΣY2i, the control device 60i determines that the overlay error is mainly caused by the exposure of the second layer in the X-axis direction and by the exposure of the first layer in the Y-axis direction.

[0261] Furthermore, the above-mentioned judgment method is just one example. In short, as long as the control device 60i determines whether the superposition 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 first marker image and the absolute position coordinates of the second marker image, there is no particular limitation on its specific judgment method.

[0262] The data on the overlay error (overlay deviation) of wafer W11 obtained by the above-described overlay measurement method, and the data on the determination of whether the overlay error is mainly caused by the exposure of the first layer or the exposure of the second layer, are fed back to the control device 60i, or to at least one of the exposure device 200 that performs the exposure of the first layer and the exposure device 200 that performs the exposure of the second layer by the measurement system control device 530.

[0263] For example, when the main cause of the overlay error is the exposure of the first layer, this data can be fed back to the exposure apparatus that performed the first layer. Furthermore, when using this exposure apparatus to perform the same first layer exposure process as for wafer W11 on wafers in a different batch than the batch containing wafer W11, the target location can be determined based on the fed-back data to reduce the overlay error with the second layer.

[0264] Furthermore, when the main cause of the overlay error is the exposure of the second layer, this data can also be fed back to the exposure apparatus 200 that performs the second layer exposure. Moreover, when the exposure apparatus 200 performs the same second layer exposure process as for wafer W11 on wafers in a different batch than the batch containing wafer W11, the target location can be determined based on the fed-back data to reduce the overlay error with the first layer.

[0265] Furthermore, data feedback can also be conducted via the mainframe computer 2000.

[0266] Furthermore, in step 318, when the absolute position coordinates of two or more markers can be obtained for all irradiated areas on wafer W11, and when the first information related to the shape and size of each irradiated area of ​​the first layer and the second information related to the shape and size of each irradiated area of ​​the second layer can be obtained, the first information can be provided (feedback) to the exposure apparatus that exposes the first layer, and the second information can be provided (feedback) to the exposure apparatus 200 that exposes the second layer. At this time, the imaging characteristic correction controller 248 can also be controlled, or at least one of the speed and direction of the tracing stage RST can be controlled, so that the shape and size of each irradiated area of ​​the second layer become the desired state.

[0267] Furthermore, in the above description, the superposition error (superposition deviation) between the first and second layers is calculated based on the absolute position coordinates of the first and second marker images. However, the absolute position coordinates of the first and second marker images can also be used as information on the superposition error (position deviation) between the first and second layers, and output by the self-measurement system 500. In this case, the data output by the self-measurement system 500 can also be provided (feedback) to at least one of the exposure apparatus (exposure apparatus 200 or other exposure apparatus) that performs the exposure of the first layer and the exposure apparatus 200 that performs the exposure of the second layer.

[0268] Alternatively, based on the absolute position coordinates of the first and second marker images, the positional deviations of the grouped first and second marker images can be calculated separately, and this positional deviation data can be output from the self-measurement system 500 as information on the superposition error (positional deviation between the first and second layers). In this case, the data output from the self-measurement system 500 can also be provided (feedback) to at least one of the exposure apparatus (exposure apparatus 200 or other exposure apparatus) performing the exposure of the first layer and the exposure apparatus 200 performing the exposure of the second layer.

[0269] As can be clearly understood from the above description, according to the overlay measurement method performed by the substrate processing system 1000 in this second embodiment, the measurement system 500 can measure the absolute position coordinates of the first marker image and the second marker image respectively, and can measure the overlay error based on these absolute position coordinates. Furthermore, superior effects not previously achieved can be obtained, namely, it can be determined whether the overlay error is mainly caused by the exposure of the lower layer or mainly caused by the exposure of the upper layer.

[0270] Furthermore, in the above description, to determine the overlay error between the first and second layers, overlay deviation measurement marks (first mark image, second mark image) were used, but wafer marks (alignment marks) can also be used. That is, the overlay error between the first and second layers can also be determined based on the absolute position coordinates of I wafer marks of the first layer and I wafer marks of the second layer.

[0271] Furthermore, since the overlap error (overlap deviation) between the first and second layers has been calculated in step S320 above, step S322 can be performed as needed.

[0272] Furthermore, as described above, after the exposure process of the second layer, the absolute position coordinates of the first marker image (or the wafer marker of the first layer) and the second marker image (or the wafer marker of the second layer) of the developed wafer W11 are obtained using the measuring device 100i of the measuring system 500. However, the absolute position coordinates of the first marker image (or the wafer marker of the first layer) of the developed wafer W11 can also be obtained using the measuring device 100i of the measuring system 500 after the exposure process of the first layer and before the exposure process of the second layer. After the exposure process of the second layer, the absolute position coordinates of the second marker image (or the wafer marker of the second layer) of the developed wafer W11 can be obtained using the measuring device 100i of the measuring system 500. At this point, the superposition error between the first and second layers can be determined by the measurement system 500 (control devices 60i, 530) or by other devices (e.g., the host computer 2000). Furthermore, the measurement device 100i used to acquire the absolute position coordinates of the first marker image (or the wafer marker of the first layer) and the measurement device 100i used to acquire the absolute position coordinates of the second marker image (or the wafer marker of the second layer) can also be different.

[0273] Furthermore, in order to perform the exposure process of the layer below the second layer, the wafer W11 can also be moved into the measurement system 500 before it is moved into the C / D device 300 (or other C / D device) after undergoing various processes (including etching and film deposition). The measurement device 100i of the measurement system 500 can be used to obtain both the absolute position coordinates of the first mark image (or the wafer mark of the first layer) and the absolute position coordinates of the second mark image (or the wafer mark of the second layer) of the wafer W11, or the absolute position coordinates of the second mark image (or the wafer mark of the second layer) of the wafer W11. In this situation, the overlay error (positional deviation between the first and second layers) of the first layer can be determined using the measurement system 500, or the absolute position coordinates information acquired by the measurement system 500 can be provided, and the overlay error (positional deviation between the first and second layers) of the first layer can be determined by other devices (such as the host computer 2000). Alternatively, the information on the overlay error (positional deviation between the first and second layers) of the first layer obtained by the measurement system 500, or the information on the absolute position coordinates acquired by the measurement system 500, can be provided to the exposure apparatus 200 or other exposure apparatuses.

[0274] Furthermore, as described above, the measurement system 500 is used to obtain information on the overlap error between the first and second layers. However, it is not limited to this; it can also obtain the overlap error between the m-th layer (lower layer, where m is an integer greater than or equal to 1) and the n-th layer (upper layer, where n is an integer greater than m and greater than 2). In this case, the n-th layer may not necessarily be the layer below the m-th layer.

[0275] Furthermore, in the second embodiment described above, the measuring device 100i for managing changes in the wafer lattice and the measuring device 100i for overlay measurement may also be different.

[0276] Furthermore, in the substrate processing system 1000 of the second embodiment described above, both the wafer lattice change management and the stacking measurement are performed, but only one of them may be performed.

[0277] Furthermore, in the substrate processing system 1000 of the second embodiment described above, the measurement system 500 is not connected to either the exposure apparatus 200 or the C / D apparatus 300, but it can be connected to one or both of them. For example, the C / D apparatus 300 can be positioned between the exposure apparatus 200 and the measurement system 500 to connect them. Alternatively, the measurement system 500 can be positioned between the exposure apparatus 200 and the C / D apparatus 300 to connect to both. In this case, the measurement system 500 may not have the carrier system 510.

[0278] Furthermore, in the first and second embodiments described above, the measurement system 500 may not have a plurality of measuring devices 100i. That is, the measurement system 500 may also have only one measuring device, for example, only measuring device 1001.

[0279] Furthermore, in the first and second embodiments described above (hereinafter referred to as the above embodiments), the following situation is explained: the signal processing device 49, which processes the detection signal of the Mark Detection System (MDS) of the measuring device 100i (i=1 to 4), only sends the measurement results of wafer marks whose waveforms are good, obtained as the detection result of the Mark Detection System (MDS), to the control device 60i. The control device 60i then uses these wafer mark measurement results to perform EGA calculations. As a result, the exposure control device 220 uses a portion of the position information of the wafer mark selected from the plurality of wafer marks whose waveforms are good, obtained as the detection result of the Mark Detection System (MDS), to perform EGA calculations. However, it is not limited to this; the signal processing device 49 may also send the measurement results of the remaining wafer marks, excluding wafer marks whose waveforms are bad, obtained as the detection result of the Mark Detection System (MDS), to the control device 60i. Alternatively, the control device 60i can replace the signal processing device 49 in determining whether the detection signal obtained from the mark detection system MDS is good. In this case, the control device 60i only uses the measurement results of the remaining wafer marks other than those whose detection signals are determined to be good or bad to perform the aforementioned EGA calculation. Furthermore, ideally, the exposure control device 220 uses a portion of the wafer marks selected from the measurement results of the wafer marks used for the EGA calculation of the control device 60i to perform the aforementioned EGA calculation.

[0280] Furthermore, in the above embodiments, the case where the C / D 300 is connected to the exposure apparatus 200 has been described. However, instead of the C / D 300, a coating apparatus (coating machine) for applying resist to the substrate (wafer) can be connected to the exposure apparatus 200. In this case, the exposed wafer will be transferred to a developing apparatus (developing machine) that is not connected to the exposure apparatus. Alternatively, instead of the C / D 300, a developing apparatus (developing machine) for developing the exposed substrate (wafer) can be connected to the exposure apparatus 200. In this case, a wafer pre-coated with resist in another location will be transferred to the exposure apparatus.

[0281] In the above embodiments, the case where the exposure apparatus is a scanning stepper has been described, but it is not limited to this. The exposure apparatus can also be a stationary exposure apparatus such as a stepper, or a reduction projection exposure apparatus that combines irradiated areas by stepping and stitching. Furthermore, the above embodiments can also be applied to multi-stage exposure apparatuses having a plurality of wafer stages, as disclosed in, for example, U.S. Patent No. 6,590,634, U.S. Patent No. 5,969,441, and U.S. Patent No. 6,208,407. Furthermore, the exposure apparatus is not limited to the aforementioned dry exposure apparatus that exposes wafer W without the use of liquid (water). For example, it can also be an immersion exposure apparatus that exposes a substrate through liquid, as described in European Patent Application Publication No. 1420298, International Patent Application Publication No. 2004 / 055803, International Patent Application Publication No. 2004 / 057590, U.S. Patent Application Publication No. 2006 / 0231206, U.S. Patent Application Publication No. 2005 / 0280791, and U.S. Patent No. 6,952,253. Moreover, the exposure apparatus is not limited to semiconductor manufacturing exposure apparatuses; for example, it can also be a liquid crystal exposure apparatus for transferring patterns of liquid crystal display elements onto a square glass plate.

[0282] Semiconductor devices are manufactured through a lithography process. This lithography process utilizes an exposure apparatus, which is part of the substrate processing system described above, to expose a photosensitive object using a patterned tracing film (photomask), and then develop the exposed photosensitive object. This allows for the production of high-density devices with excellent yield.

[0283] Furthermore, in addition to lithography, the manufacturing process of semiconductor devices may also include steps such as designing the function and performance of the device, making a lithography mask based on the design, device assembly (including cutting, bonding and packaging), and inspection.

[0284] 10: Sliding parts 12: Finalization 14: Vibration damping device 16: Base Frame 18: Air bearing 20: Drive System 20A: First drive unit 20B: Second drive unit 22a, 22b: Movable parts 23a, 23b: Movable parts 24: Movable platform 25a, 25b: Fasteners 26a, 26b: Fasteners 28A, 28B: X-axis linear motors 29A, 29B: Y-axis linear motors 30: First Position Measurement System 32: Read the head 33: Encoder System 35a~35d: Laser interferometer 37x:X Reader 37ya, 37yb:Y readhead 40: Measurement Unit 48: Vibration damping device 50: Second position measurement system 52A, 52B: Read the head 58X1, 58X2: XZ Reader 58Y1, 58Y2: YZ Reader 60i: Control device 70i: Wafer Transfer System 530: Measurement system control device 100i: Measuring device 200: Exposure device 300:C / D 330: Temperature Control Section 500: Measurement System 510: EFEM System 512:EFEM ontology 514: Loading port 516: Robot 521: Transport System 524: Loading and transporting components 526: Unloading and transporting components 1000: Substrate Processing System MDS: Marking Detection System RG1: Grating RG2a, RG2b: gratings W: Wafer WST: Wafer Stage

Claims

1. A measuring apparatus for measuring the positions of a plurality of marks formed on a substrate, comprising: a slider capable of holding the substrate and moving it on a movable plane; a mark detection system for detecting marks formed on the substrate held by the slider; and a position measuring system for acquiring position information and tilt information of the slider; acquiring mark position information by detecting the marks by the mark detection system and acquiring the position information of the slider by the position measuring system; and correcting the mark position information by acquiring the tilt information by the position measuring system.

2. The measuring device as claimed in claim 1, wherein, The aforementioned position measurement system has a first grid portion irradiated by a plurality of measurement beams, and a first reading head that irradiates the aforementioned first grid portion with the aforementioned measurement beams and receives return beams from the aforementioned first grid portion. One of the aforementioned first grid portion and the aforementioned first reading head is disposed on the aforementioned slider. The aforementioned tilt information is the tilt of the aforementioned slider relative to the aforementioned moving plane obtained based on the plurality of aforementioned return beams.

3. The measuring device as described in claim 2, wherein, The aforementioned slider can move along the first direction of the aforementioned moving plane, along the second direction of the aforementioned moving plane and intersecting the aforementioned first direction, and in the third direction intersecting the aforementioned first and second directions; the aforementioned tilt information includes the amount of rotation about the aforementioned first direction and the amount of rotation about the aforementioned second direction; based on the aforementioned tilt information of the aforementioned slider and the distance between the surface of the aforementioned substrate with the aforementioned mark and the aforementioned first grid portion and the aforementioned third direction, the aforementioned mark position information is corrected.

4. The measuring device of claim 3 further includes a reference member; the aforementioned position measuring system includes: a first position measuring system having the aforementioned first grid portion and the aforementioned first reading head, and acquiring relative position information of the aforementioned slider relative to the aforementioned reference member; and a second position measuring system acquiring relative position information of the aforementioned mark detection system relative to the aforementioned reference member.

5. The measuring device as described in claim 4, wherein, In the aforementioned reference component, one of the aforementioned first grid portion and the aforementioned first reading head is provided, as well as one of the aforementioned second grid portion and the aforementioned second reading head provided in the aforementioned second position measurement system; In the aforementioned mark detection system, the other of the aforementioned second grid portion and the aforementioned second reading head is provided.

6. The measuring device as described in claim 5, wherein, The aforementioned reference component has a fixed plate on the surface of the aforementioned moving plane.

7. The measuring device according to claim 3, comprising: a height detection system that detects the height of the surface of the aforementioned substrate; and a drive system that, based on the detection result of the aforementioned height detection system, adjusts the position of the aforementioned slider in the aforementioned third direction, the amount of rotation about the aforementioned first direction, and the amount of rotation about the aforementioned second direction; and corrects the aforementioned mark position information using the tilt information of the aforementioned slider obtained by the aforementioned position measurement system after adjustment.

8. The measuring device as claimed in claim 7, wherein, The height distribution information of the substrate is obtained from the detection results of the aforementioned height detection system and the position information of the aforementioned slider obtained by the aforementioned position measurement system.

9. The measuring device as claimed in claim 3, wherein, The aforementioned position measurement system comprises: a first measurement system that measures the position of the aforementioned slider in the aforementioned third direction at at least three locations; and a second measurement system that measures the position of the aforementioned slider in the aforementioned second and third directions.

10. The measuring device as claimed in claim 9, wherein, The first measurement system is a laser interferometer that measures the position in the third direction by reflecting the measurement beam through the first grid section. The second measurement system is an encoder that measures the position in the second and third directions by diffracting the measurement beam through the first grid section.

11. The measuring device as claimed in claim 10, wherein, The aforementioned first grid section includes: a grid layer that diffracts the aforementioned measurement beam of the aforementioned second measurement system; and a filter disposed on the side of the aforementioned grid layer where the aforementioned measurement beam is incident, allowing the aforementioned measurement beam of the aforementioned second measurement system to pass through, while preventing the aforementioned measurement beam of the aforementioned first measurement system from passing through.

12. A method for measuring the position of a mark, comprising measuring the position of a plurality of marks formed on a substrate, wherein, The mark formed on the substrate held by the slider that can move on the movable plane is detected, and the position information and tilt information of the slider are obtained. The mark position information is obtained by using the detection result of the mark and the position information of the slider. The tilt information is used to correct the mark position information.

13. A substrate processing system comprising: a measuring device as described in claim 1; and an exposure device for exposing a substrate; wherein the exposure device exposes the substrate based on position information of a mark measured and corrected by the measuring device.

14. An exposure method comprising obtaining position information of a plurality of marks formed on a substrate by means of a mark position measurement method as described in claim 12, and exposing the substrate based on the obtained position information of the plurality of marks.

Images