Measuring apparatus and methods, photolithography systems, exposure apparatus and methods

Abstract

The present invention provides a measuring apparatus and method, a photolithography system, an exposure apparatus and method, the measuring apparatus (100) comprising a slider (10) capable of maintaining a substrate (W) and moving parallel to the XY plane, a driving system for driving the slider, a position measuring system (30) capable of illuminating a plurality of light beams from a reading head (32) onto a measuring surface provided on the slider having a grid portion (RG1) and receiving return beams from each of the plurality of light beams from the measuring surface to measure the position information of the slider in at least three degrees of freedom directions including absolute position coordinates, a mark detection system (MDS) for detecting marks on the substrate, and a control device for controlling the driving of the slider and using the mark detection system to detect a plurality of marks on the substrate respectively, and determining the absolute position coordinates of each mark based on the detection results of each mark and the measurement information of the position measuring system during detection.

Description

[0001] This application is a divisional application of the invention patent application filed on February 23, 2016, with application number 201680012129.1, entitled "Measuring device, lithography system and exposure device, and management method, overlay measurement method and component manufacturing method". Technical Field

[0002] This invention relates to a measuring device, a lithography system and an exposure apparatus, as well as management methods, overlay measurement methods and component manufacturing methods. In particular, it relates to a measuring device for measuring the position information of multiple marks formed on a substrate, an exposure apparatus having an exposure apparatus having a substrate stage having completed the measurement of the position information of multiple marks performed by the measuring device, a lithography system having the measuring device, an exposure apparatus having the measuring device, a management method for managing changes in the arrangement of multiple regions on a substrate, an overlay measurement method for measuring a substrate, and a component manufacturing method using the lithography system or exposure apparatus. Background Technology

[0003] In the photolithography process for manufacturing semiconductor components, multiple layers of circuit patterns are superimposed on a substrate such as a wafer or glass plate (hereinafter collectively referred to as a wafer). However, when the superposition accuracy between layers is poor, the semiconductor components cannot perform their intended circuit characteristics and may sometimes become defective products. Therefore, marks (alignment marks) are typically pre-formed in each of the multiple irradiation (shot) areas on the wafer, and 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 these marks and the known position information of the newly formed pattern (e.g., a scribe line pattern), wafer alignment is performed to position one irradiation area on the wafer relative to the pattern.

[0004] As a wafer alignment method, in order to balance yield, the mainstream approach is to detect the alignment marks of only a few irradiated areas (also known as sampling irradiated areas or alignment irradiated areas) on the wafer and calculate the arrangement of the irradiated areas on the wafer in a statistical manner, which is called full wafer enhancement alignment (EGA).

[0005] However, when overlapping exposures are performed on a wafer during the photolithography process, the wafer, which has undergone processes such as photoresist coating, development, etching, CVD (chemical vapor deposition), and CMP (chemical mechanical polishing), may experience deformation in the arrangement of the irradiated areas of the previous layer due to these processes. This deformation can potentially lead to a decrease in overlapping accuracy. In view of this, recent exposure apparatuses have incorporated grid correction functions that not only correct the primary composition of the wafer but also correct nonlinear components of the irradiated arrangement caused by the process (for example, see Patent Document 1).

[0006] Traditionally, wafer grid variations caused by the equipment have been managed, for example, by using a special grid management sheet for overlapping exposures on a marked reference wafer. Here, a wafer grid refers to a grid formed by linking the centers of the irradiated areas on the wafer, arranged according to an irradiation zoning map (data regarding the arrangement of irradiated areas formed on the wafer). In this specification, the wafer grid is also simply referred to as a "grid" or described as "arrangement of irradiated areas (or irradiation)".

[0007] Ideally, grid management would be used for each illumination zone map, but this would require countless marking sheets and countless wafers. Therefore, a reference wafer and the aforementioned dedicated marking sheets are used.

[0008] However, the markings that can be etched onto a reference wafer, no matter how fine, are limited and discrete, making wafer lattice management difficult using the irradiation pattern of the exposure equipment user's workpiece. Furthermore, lattice management using a reference wafer generally involves certain compromises based on the following assumptions.

[0009] The error of the grid is dependent on the coordinates, and the same error exists in the same location. If the point is near a point where the marked position has been measured and the grid error correction has been made, the error is considered to be small.

[0010] Errors in scanning speed or scanning acceleration will not cause grid errors. Even if grid errors were to occur, since these errors do not change with each scan, they only require adjustment once and do not necessitate regular maintenance.

[0011] Prior art literature

[0012] [Patent Document 1] U.S. Application Publication No. 2002 / 0042664. Summary of the Invention

[0013] A first embodiment of the present invention provides a measuring apparatus for measuring the position information of a plurality of marks formed on a substrate, comprising: a stage for holding the substrate and being movable; a driving system for driving the stage; an absolute position measuring system having a measuring surface having a grid portion and a reading head for irradiating a light beam onto the measuring surface on the stage, wherein a light beam from the reading head irradiates the measuring surface and a return light beam returning from the measuring surface is received to obtain the position information of the stage; a mark detection system for detecting marks formed on the substrate; and a control device for controlling the movement of the stage performed by the driving system, using the mark detection system to detect the plurality of marks formed on the substrate respectively, and calculating the absolute position coordinates of the plurality of marks based on the detection results of the plurality of marks and the position information of the stage obtained by the absolute position measuring system when the plurality of marks were detected.

[0014] A second embodiment of the present invention provides a photolithography system comprising: a measuring device of the first embodiment; and an exposure device having a substrate stage on which the substrate after the measuring device has measured the position information of a plurality of marks is placed, and for the substrate placed on the substrate stage, an alignment measurement is performed to measure the position information of a selected portion of the plurality of marks on the substrate, and an exposure is performed to expose the substrate with an energy beam.

[0015] A third embodiment of the present invention provides a component manufacturing method, comprising: exposing a substrate using a photolithography system of the second embodiment; and developing the exposed substrate.

[0016] The fourth embodiment of the present invention provides an exposure apparatus having the measuring device of the first embodiment, for exposing a substrate for which position information of a plurality of marks has been obtained using the measuring device with an energy beam.

[0017] A fifth embodiment of the present invention provides a component manufacturing method, comprising: exposing a substrate using an exposure apparatus of a fourth embodiment; and developing the exposed substrate.

[0018] A sixth embodiment of the present invention provides a management method for managing changes in the arrangement of multiple regions configured in a matrix on a substrate, comprising: sequentially transferring a pattern and markings formed on a mask onto the substrate using an exposure apparatus, thereby forming multiple regions on the substrate together with the markings; mounting the substrate having the multiple regions on a stage provided on one of a measurement surface having a grid and a read head irradiating the measurement surface with a light beam and movable within a predetermined plane; using an absolute position measurement system to measure the position information of the stage while using a mark detection system to detect the markings corresponding to the multiple regions on the substrate. Multiple markers are used to determine the absolute position coordinates of the multiple markers corresponding to the multiple division areas on the substrate in a predetermined plane based on the detection results of the multiple markers and the measurement information of the absolute position measurement system at the time of detection of the multiple markers. The absolute position measurement system can measure the position information including the absolute position coordinates of the stage in the predetermined plane by irradiating a light beam through a reading head on a measurement surface with a grid portion disposed on the stage and receiving the return light beam from the measurement surface of the light beam. The system also determines the arrangement information of the multiple division areas based on the determined absolute position coordinates of the multiple markers.

[0019] A seventh embodiment of the present invention provides an overlay measurement method. The method uses a substrate on which a first mark image and a corresponding second mark image are formed in a predetermined positional relationship through exposure of a first layer and exposure of a second layer with the first layer as the bottom layer. The substrate is used as the measurement object. The method includes: mounting the substrate on a stage having a measurement surface with a grid and a read head that irradiates the measurement surface with a light beam; measuring the position information of the stage using a position measurement system; and detecting the multiple groups of first and second mark images on the substrate using a mark detection system. The method then determines the measurement based on the multiple groups of first and second mark images. The detection results of each of the two marker images and the measurement information of the position measurement system during the detection of each marker image are used to determine the absolute position coordinates of the first and second marker images in the predetermined plane of the plurality of groups on the substrate. The position measurement system illuminates the measurement surface with a plurality of light beams via the read head and receives the return beams of the plurality of light beams from the measurement surface. It is capable of measuring position information in at least three degrees of freedom directions of the absolute position coordinates in the predetermined plane including the stage. The system also determines the overlap error based on the absolute position coordinates of the first and second marker images that are grouped together. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 This is a perspective view that schematically shows the configuration of the measuring device according to the first embodiment.

[0022] Figure 2 (A) is omitted Figure 1 A front view of a portion of the measuring device (viewed from the -Y direction). Figure 2 (B) is a cross-sectional view of the measuring device, with the XZ plane of the optical axis AX1 of the mark detection system as the section, omitting a part of the measuring device.

[0023] Figure 3 This is a cross-sectional view with a portion of the measuring device omitted, using the YZ plane of the optical axis AX1 of the mark detection system as the cross-section.

[0024] Figure 4 Image A is a three-dimensional view showing the read head of the first position measurement system. Figure 4 (B) is a top view of the read head of the first position measurement system (viewed from the +Z direction).

[0025] Figure 5 This is a diagram used to illustrate the configuration of the second position measurement system.

[0026] Figure 6 This is a block diagram showing the input-output relationship of a control device centered on the control system of the measuring device in the first embodiment.

[0027] Figure 7 This is a flowchart of the processing algorithm of the control device when processing a batch of wafers.

[0028] Figure 8 This is a diagram that roughly shows the overall configuration of the lithography system according to the second embodiment.

[0029] Figure 9 It is a summary display Figure 8 The diagram shows the configuration of the exposure apparatus.

[0030] Figure 10 It is a block diagram showing the input-output relationship of the exposure control device of the exposure apparatus.

[0031] Figure 11This is a diagram that roughly illustrates the process flow when the wafer lattice management method caused by the exposure device using the measuring device 100 is applied to the lithography system 1000.

[0032] Figure 12 This is a diagram that roughly shows the processing flow when the overlapping measurement method using the measuring device 100 is applied to the lithography system 1000.

[0033] Figure 13 This is a diagram that roughly shows the overall configuration of the photolithography system in the modified example.

[0034] Symbol Explanation

[0035] 10: Slider; 10a: Recess; 12: Platform; 14: Vibration damping device; 16: Base; 18: Air bearing; 20: Drive system; 20A: First drive device; 20B: Second drive device; 22a, 22b: Movable element; 23a, 23b: Movable element; 24: Movable platform; 25a, 25b: Fixed element; 26a, 26b: Fixed element; 28A, 28B: X-axis linear motor; 29A, 29B: Y-axis linear motor; 30: First position measurement system; 32: Reader head; 33: Encoder system; 35a-35d: Laser interferometer; 37x: X-axis reader head; 37 ya, 37yb: Y read head; 40: Measurement unit; 48: Vibration damping device; 50: Second position measurement system; 52A, 52B: Read head; 58X1, 58X2: XZ read head; 58Y1, 58Y2: YZ read head; 60: Control device; 100: Measurement device; 100a, 100b: Measurement device; 200: Exposure device; 300: C / D converter; 330: Temperature control unit; 1000: Photolithography system; AX1: Optical axis; MDS: Mark detection system; RG1: Grating; RG2a, RG2b: Grating; W: Wafer; WH: Wafer holder; WST: Wafer stage. Detailed Implementation

[0036] Implementation Method 1

[0037] Hereinafter, based on the first embodiment... Figures 1 to 7 Please provide an explanation. Figure 1 This is a perspective view that schematically shows the configuration of the measuring device 100 according to the first embodiment. Figure 1The measuring device 100 shown is actually composed of a chamber and constituent parts housed inside the chamber, but in this embodiment, the description of the chamber is omitted. In this embodiment, as described later, a mark detection system MDS is provided. Hereinafter, the direction of the optical axis AX1 of the mark detection system MDS is defined as the Z-axis direction, the direction of the movable stage moving with a long stroke (described later) in a plane orthogonal to it is defined as the Y-axis direction, the direction orthogonal to the Z-axis and Y-axis is defined as the X-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are defined as θx, θy, and θz directions, respectively. Here, the mark detection system MDS has an L-shaped shape when viewed from the side (e.g., from the +X direction), and a cylindrical lens section 41 is provided at its lower end (apex). Inside the lens section 41, an optical system (refractive optical system) composed of multiple lens assemblies having an optical axis AX1 in the Z-axis direction is housed. In this specification, for ease of explanation, the optical axis AX1 of the refractive optical system inside the lens barrel 41 is referred to as the optical axis AX1 of the mark detection system MDS.

[0038] exist Figure 2 (A) shows partial omissions. Figure 1 The front view of the measuring device 100 (viewed from the -Y direction), in Figure 2 (B) shows a cross-sectional view of the measuring device 100 with the XZ plane passing through the optical axis AX1 as the section, albeit with partial omission. Additionally, in Figure 3 The cross-sectional view of the measuring device 100 with the YZ plane passing through the optical axis AX1 as the section is also shown in a partially omitted manner.

[0039] Measuring device 100 Figure 1 The device includes: a platform 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 the slider) 10 disposed on the platform 12, capable of maintaining the wafer W relative to the platform 12 with a predetermined stroke in the X and Y axis directions and capable of slight movement (micro-displacement) in the Z, θx, θy, and θz directions; and a drive system 20 for driving the slider 10. Figure 1 Not shown in the image, please refer to the diagram. Figure 6 The first position measurement system 30 (in) measures the position information of the slider 10 relative to the platform 12 in each direction (hereinafter referred to as the 6-DOF directions) along the X-axis, Y-axis, Z-axis, θx, θy, and θz. Figure 1 Not shown in the image, please refer to the diagram. Figure 3 , Figure 6 ), a measurement unit 40 of a mark detection system MDS that detects marks mounted (held) on a wafer W of a slide 10, and a second position measurement system 50 that measures the relative position information of the mark detection system MDS (measurement unit 40) and the platform 12. Figure 1 Not shown in the image, please refer to the diagram. Figure 6 ), and a control device 60 that, while controlling the drive of the slider 10 by the drive system 20, acquires measurement information from 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 multiple marks held on the wafer W of the slider 10. Figure 1 Not shown in the image, please refer to the diagram. Figure 6 ).

[0040] Platform 12 is composed of a rectangular (or square) cuboid component viewed from above, the surface of which is machined to have an extremely high degree of flatness, forming a guiding surface for the movement of slider 10. The material used for platform 12 is a material with a low thermal expansion rate, also known as a zero-expansion material, such as invar alloy, ultra-low expansion cast steel, or ultra-low expansion glass ceramic.

[0041] On platform 12, a total of three openings 12a with bottom openings are formed, one at the center of the -Y side surface in the X-axis direction and one at each of the two ends of the +Y side surface in the X-axis direction. Figure 1 The image shows one of the three vacancy 12a located on the surface on the -Y side. A vibration damping device 14 is disposed inside each of the vacancy 12a. On a rectangular base 16 positioned on the ground F and parallel to the XY plane, the platform 12 is supported at three points by the three vibration damping devices 14, ensuring that its surface is approximately parallel to the XY plane. Furthermore, the number of vibration damping devices 14 is not limited to three.

[0042] like Figure 3 The slide 10 shown has four air static pressure bearings (air bearings) 18 installed at each of its four corners on its bottom surface, with each bearing surface approximately flush with the bottom surface of the slide 10. The slide 10 is suspended above the platform 12 by the static pressure (pressure within the gap) between the bearing surfaces of the pressurized air ejected from these four air bearings toward the platform 12 and the top surface (guide surface) of the platform 12. This suspension is achieved through a predetermined gap (or void), for example, a gap of several μm. In this embodiment, the slide 10 is made of zero-expansion glass (e.g., Zerodur from Schott Corporation).

[0043] A recess 10a of predetermined depth, slightly larger in inner diameter than the diameter of the wafer W, is formed on the upper part of the slide member 10. A wafer holder WH, with a diameter approximately the same as that of the wafer W, is disposed inside the recess 10a. The wafer holder WH can be a vacuum chuck, an electrostatic chuck, or a mechanical chuck; as an example, a pin chuck is used. The wafer W is held by the wafer holder WH with the top surface of the wafer W approximately flush with the top surface of the slide member 10. Multiple suction ports are formed in the wafer holder WH, and these ports are connected to a vacuum pump 11 (see reference 11) via a vacuum piping system (not shown). Figure 6 The vacuum pump 11 is controlled by the control device 60 to turn on and off. Furthermore, either or both of the slider 10 and the wafer holder WH may be referred to as the "first substrate holding member".

[0044] Additionally, the slide 10 is provided with, for example, three circular openings formed on the wafer holder WH, which allow it to move up and down, in conjunction with the wafer transport system 70. Figure 1 Not shown in the image, please refer to the diagram. Figure 6 A moving member (not shown) that coordinates the loading and unloading of the wafer onto and from the wafer holder WH. The drive unit 13 that drives the moving member is controlled by the control unit 60 (see reference). Figure 6 ).

[0045] In this embodiment, the wafer holder WH is, for example, a 300 mm wafer with a diameter of 300 mm. Furthermore, if the wafer transport system 70 has a non-contact holding member that attracts and holds the wafer on the wafer holder WH from above in a non-contact manner, such as a Bernoulli chuck, then there is no need to provide a vertical movement member on the slide 10, nor is it necessary to form a circular opening for the vertical movement member in the wafer holder WH.

[0046] like Figure 2 (B) and Figure 3 As shown, in a region slightly larger than wafer W below the slider 10, a two-dimensional grating (hereinafter referred to as the grating) RG1 is horizontally arranged (parallel to the surface of wafer W). The grating RG1 includes a reflective diffraction grating (X-diffraction grating) with a periodic direction along the X-axis and a reflective diffraction grating (Y-diffraction grating) with a periodic direction along the Y-axis. The pitch of the grid lines of the X-diffraction grating and the Y-diffraction grating is, for example, set to 1 μm.

[0047] The vibration damping device 14 is an active vibration isolation system (AVIS), which includes an accelerometer, a displacement sensor (such as a capacitance sensor), an actuator (such as a voice coil motor), and an air mount with air damping function. The vibration damping device 14 attenuates higher-frequency vibrations through the air mount and further dampens (contains) vibrations through the actuator. Therefore, the vibration damping device 14 can prevent the transmission of vibrations between the platform 12 and the base 16. Alternatively, a hydraulic damper can be used instead of an air mount.

[0048] The reason for installing an actuator separately from the air damper is that the internal pressure of the gas in the air damper's gas chamber is high, and the control response can only be ensured at around 20Hz. Therefore, in situations requiring high-response control, the actuator must be controlled according to the output of an accelerometer (not shown). However, micro-vibrations such as ground vibrations are eliminated by the air damper.

[0049] The upper end face of the vibration damping device 14 is connected to the platform 12. Gas (e.g., compressed air) can be supplied to the air damper via 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) according to the amount of gas filled inside (pressure change of the compressed air). Therefore, by individually moving the air damper of each of the three vibration damping devices 14 up and down at three points on the platform 12 from below, the positions of the platform 12 and the slider 10 suspended and supported thereon can be arbitrarily adjusted in the Z-axis, θx, and θy directions, respectively. Furthermore, the actuator of the vibration damping device 14 can drive the platform 12 not only in the Z-axis direction but also in the X-axis and Y-axis directions. Additionally, 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 60 (see reference 60). Figure 6 The other three vibration damping devices 14 are not limited to the X-axis, Y-axis, and Z-axis directions; for example, they may have actuators for moving the platform 12 in six degrees of freedom. The control device 60 constantly and in real-time controls the actuators of the three vibration damping devices 14 based on the relative position information between the marker detection system MDS (measuring unit 40) and the platform 12 measured by the second position measurement system 50, so that the position of the platform 12 in the six degrees of freedom direction, which is fixed to the reading head 32 of the first position measurement system 30 (described later), is maintained in a desired positional relationship relative to the marker detection system MDS. Alternatively, feedforward control can be performed on each of the three vibration damping devices 14. For example, the control device 60 can perform feedforward control on each of the three vibration damping devices 14 based on the measurement information from the first position measurement system 30. The control of the vibration damping devices 14 by the control device 60 will be described later.

[0050] like Figure 6 As shown, the drive system 20 includes a first drive device 20A that drives the slider 10 in the X-axis direction, and a second drive device 20B that drives the slider 10 and the first drive device 20A together in the Y-axis direction.

[0051] Depend on Figure 1 and Figure 3 It can be seen that on the -Y side of the slider 10, a pair of movable parts 22a, composed of magnetic units (or coil units) and shaped like an inverted L, are fixed at predetermined intervals in the X-axis direction. On the +Y side of the slider 10, as... Figure 3 As shown, a pair of movable elements 22b, composed of magnetic units (or coil units), are fixed at predetermined intervals along the X-axis (however, the movable element 22b on the +X side is not shown). The pair of movable elements 22a and the pair of movable elements 22b are arranged symmetrically from left to right and have the same structure.

[0052] Motionless units 22a and 22b, such as Figures 1-3 As shown, a pair of plate members 24a and 24b, which are arranged at predetermined distances in the Y-axis direction and extend in the X-axis direction respectively, are supported non-contactly on the upper surface of a movable platform 24 that forms part of a rectangular frame in plan view. Specifically, air bearings (not shown) are provided on the underside of the movable members 22a and 22b (the surfaces opposite to 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 on 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 on the platform 12, as described above.

[0053] On top of each of the pair of plate members 24a and 24b, as Figures 1-3 As shown, the fixing elements 26a and 26b, which are composed of coil units (or magnet units), are arranged in the region outside the two ends in the X-axis direction.

[0054] The electromagnetic interaction between a pair of movable elements 22a and fixed elements 26a generates a driving force (electromagnetic force) that drives the movable elements 22a in the X-axis direction and a driving force (electromagnetic force) that drives them in the Y-axis direction. Similarly, the electromagnetic interaction between a pair of movable elements 22b and fixed elements 26b generates a driving force (electromagnetic force) that drives the movable elements 22b in the X-axis direction and a driving force (electromagnetic force) that drives them in the Y-axis direction. In other words, the pair of movable elements 22a and fixed elements 26a constitute an XY linear motor 28A that generates driving forces in the X-axis and Y-axis directions; the pair of movable elements 22b and fixed elements 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 driving device 20A that drives the slider 10 with a predetermined stroke in the X-axis direction and slightly drives it in the Y-axis direction (see reference). Figure 6 The first drive unit 20A drives the slider 10 in the θz direction by making the X-axis driving forces generated by the XY linear motors 28A and 28B different in magnitude. The first drive unit 20A is controlled by the control unit 60 (see reference). Figure 6 In this embodiment, according to the relationship that the first drive device 20A together with the second drive device described later constitutes a coarse and fine motion drive system for driving the slider 10 in the Y-axis direction, the first drive device 20A generates not only driving force in the X-axis direction but also driving force in the Y-axis direction, but the first drive device 20A does not necessarily have to generate driving force in the Y-axis direction.

[0055] 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 in the X-axis direction and extending in the Y-axis direction respectively. Height differences are formed at both ends of the connecting structural members 24c and 24d in the Y-axis direction. With one end of the long side of the plate member 24a placed on the height difference on the -Y side of each connecting structural member 24c and 24d, the connecting structural members 24c and 24d are integrated with the plate member 24a. Furthermore, with one end of the long side of the plate member 24b placed on the height difference on the +Y side of each connecting structural member 24c and 24d, the connecting structural members 24c and 24d are integrated with the plate member 24b (see reference). Figure 2 (B) In this manner, a pair of plate members 24a and 24b are connected by a pair of connecting structural members 24c and 24d to form a rectangular frame-shaped movable platform 24.

[0056] like Figure 1 and Figure 2As shown in (A), a pair of linear conductors 27a and 27b extending in the Y-axis direction are fixed near both ends of the base 16 in the X-axis direction. Inside the linear conductor 27a on the +X side, a fixture 25a (see reference) is housed for a Y-axis linear motor 29A composed of coil units (or magnet units) extending approximately the entire length of the Y-axis near the surfaces on the upper and -X sides. Figure 2 (B) A movable element 23a, consisting of L-shaped cross-section magnet units (or coil units), is arranged opposite to the upper and -X side surfaces of the linear conductor 27a. Together with the fixed element 25a, it forms the Y-axis linear motor 29A. Air bearings that eject pressurized air to the opposing surfaces are fixed to the lower and +X side surfaces of the movable element 23a, which are not respectively opposite to the upper and -X side surfaces of the linear conductor 27a. In particular, the air bearing fixed to the +X side surface of the movable element 23a is a vacuum preload type air bearing. This vacuum preload type air bearing maintains the X-axis clearance (gap) between the movable element 23a and the linear conductor 27a at a fixed value by balancing the static pressure of the pressurized air between the bearing surface and the -X side surface of the linear conductor 27a.

[0057] On the upper part of the movable element 23a, multiple X-guide members 19, for example composed of two cuboid components, are fixed at predetermined intervals along the Y-axis. Each of the two X-guide members 19 engages non-contactly with a sliding member 21 that, together with the X-guide member 19, forms a single-axis guide device with an inverted U-shaped cross-section. Air bearings are provided on the three faces of the sliding member 21 opposite to the X-guide members 19.

[0058] Two sliding components 21, such as Figure 1 As shown, they are fixed to the underside (on the -Z side) of the connecting member 24c.

[0059] Another linear conductor 27b located on the -X side houses a retainer 25b for a Y-axis linear motor 29B composed of coil units (or magnet units). It is symmetrical about the left and right and has the same configuration as the linear conductor 27a (see reference). Figure 2 (B) Opposite to the upper and +X side surfaces of the linear guide 27b, a movable element 23b is arranged symmetrically and is composed of L-shaped magnet units (or coil units) with the same cross-section as the movable element 23a. Together with the fixed element 25b, it forms the Y-axis linear motor 29B. Opposite to the upper and +X side surfaces of the linear guide 27b, air bearings are fixed to the lower and -X side surfaces of the movable element 23b, respectively. In particular, a vacuum preload type air bearing is used for the air bearing fixed to the -X side surface of the movable element 23b. This vacuum preload type air bearing maintains the X-axis gap (clearance, gap) between the movable element 23b and the linear guide 27b at a fixed value.

[0060] Between the upper surface of the movable part 23b and the bottom surface of the connecting member 24d, two single-axis guide devices are provided, similar to those described above, consisting of an X-guide 19 and a sliding member 21 that engages with the X-guide 19 in a non-contact manner.

[0061] The movable platform 24 is supported from below by movable elements 23a and 23b via two single-axis guide devices on the +X side and two on the -X side (a total of four), and can move along the X-axis direction on the movable elements 23a and 23b. Therefore, when the slider 10 is driven in the X-axis direction by the first drive device 20A, the reaction force of the drive force acts on the movable platform 24 on which the fixed elements 26a and 26b are mounted, and the movable platform 24 moves in the opposite direction to the slider 10 according to the law of conservation of momentum. That is, the vibration caused by the reaction force of the drive force on the slider 10 in the X-axis direction can be prevented (or effectively suppressed) by the movement of the movable platform 24. In other words, the movable platform 24 functions as a balancing mass when the slider 10 moves in the X-axis direction. However, it is not always necessary for the movable platform 24 to function as a balancing mass. In addition, since the slider 10 moves only slightly in the Y-axis direction relative to the movable stage 24, although it is not specially provided, it can also be provided with a balancing mass to prevent (or effectively suppress) the vibration caused by the driving force that drives the slider 10 in the Y-axis direction relative to the movable stage 24.

[0062] Y-axis linear motor 29A generates a driving force (electromagnetic force) that drives the movable element 23a in the Y-axis direction through the electromagnetic interaction between the movable element 23a and the fixed element 25a. Y-axis linear motor 29B generates a driving force (electromagnetic force) that drives the movable element 23b in the Y-axis direction through the electromagnetic interaction between the movable element 23b and the fixed element 25b.

[0063] The driving force in the Y-axis direction generated by the Y-axis linear motors 29A and 29B acts on the movable platform 24 via two single-axis guide devices on the +X and -X sides. Accordingly, the slider 10, integral with the movable platform 24, is driven in the Y-axis direction. That is, in this embodiment, the movable platform 24, four single-axis guide devices, and a pair of Y-axis linear motors 29A and 29B constitute the second driving device 20B for driving the slider 10 in the Y-axis direction (see reference). Figure 6 ).

[0064] In this embodiment, the pair of Y-axis linear motors 29A and 29B are physically separated from the platform 12, and are also separated from vibration by three vibration damping devices 14. Alternatively, the linear guides 27a and 27b, respectively provided on the fixing elements 25a and 25b of the pair of Y-axis linear motors 29A and 29B, can be made movable relative to the base 16 in the Y-axis direction, so as to function as a balancing mass when the slider 10 is driven in the Y-axis direction.

[0065] Measurement unit 40, such as Figure 1 As shown, the unit body 42 has a notch-shaped cavity 42a with a bottom opening formed on the surface on the -Y side, the mark detection system MDS connected to the unit body 42 with its base end inserted into the cavity 42a, and the connecting mechanism 43 connecting the lens barrel portion 41 of the front end of the mark detection system MDS to the unit body 42.

[0066] The connecting mechanism 43 includes a support plate 44 that supports the lens barrel 41 on the back side (+Y side) via a mounting member not shown, and a pair of support arms 45a, 45b that support the support plate 44 at one end and fix the other end to the bottom surface of the unit body 42.

[0067] In this embodiment, a photoresist is coated on the wafer held on the slider 10. A detection beam of a wavelength that will not expose the photoresist is used as the mark detection system (MDS). For example, the MDS uses a broadband detection beam that will not expose the photoresist on the wafer to illuminate the target mark. An image of the target mark and an image of an unmarked pointer (a pointer pattern on an internal pointer plate) are captured by an imaging component (CCD, etc.) on the illuminated surface. The image is then processed using an FIA (Field Image Alignment) system that outputs these photographic signals. The photographic signals from the mark detection system (MDS) are transmitted via a signal processing device 49. Figure 1 Not shown in the image, please refer to the diagram. Figure 6 ) is supplied to control device 60 (refer to Figure 6 The Mark Detection System (MDS) features alignment autofocus, which adjusts the focal position of the optical system.

[0068] Between the lens barrel 41 and the support plate 44, such as Figure 1 As shown, a reader mounting member 51 with a roughly isosceles triangular shape is configured. The reader mounting member 51 has a... Figure 1 The lens barrel 41 is mounted (fixed) to the support plate 44 via a mounting member (not shown) inserted into the opening along the Y-axis. Additionally, the back of the read head mounting member 51 is also fixed to the support plate 44. In this manner, the lens barrel 41 (mark detection system MDS), the read head mounting member 51, and the support plate 44 are integrated with the unit body 42 via a pair of support arms 45a and 45b.

[0069] Inside the unit body 42, there is a signal processing device 49, etc., that processes the photographic signal output as a detection signal from the marker detection system MDS to calculate the position information of the object marker relative to the detection center, and outputs it to the control device 60. The unit body 42 is supported from below at three points via multiple, for example, three, vibration damping devices 48 on a portal-shaped support frame 46 located on the base 16 from the -Y side. Each vibration damping device 48 is an active vibration isolation system (AVIS), equipped with an accelerometer, a displacement sensor (e.g., a capacitance sensor), an actuator (e.g., a voice coil motor), and a mechanical damper such as an air damper or a hydraulic damper. The vibration damping device 48 can attenuate higher-frequency vibrations through mechanical damping and can perform vibration damping (vibration control) through the actuator. Therefore, each vibration damping device 48 can prevent higher-frequency vibrations from being transmitted between the support frame 46 and the unit body 42.

[0070] Furthermore, the mark detection system MDS is not limited to the FIA ​​system. For example, instead of the FIA ​​system, a diffraction interferometry type alignment detection system can be used to illuminate the object mark with coherent detection light, causing two diffracted lights (e.g., diffracted lights of the same order or diffracted lights diffracting in the same direction) generated from the object mark to interfere, and then outputting a detection signal. Alternatively, a diffraction interferometry type alignment system can be used in conjunction with the FIA ​​system to simultaneously detect two object marks. In addition, the mark detection system MDS can also be a beam scanning type alignment system that scans the object mark with measurement light in a predetermined direction while the slider 10 is moved in a predetermined direction. In addition, although the mark detection system MDS has an autofocus function, the measurement unit 40 can also be equipped with a focal position detection system, such as a multi-point focal position detection system with the same configuration as that disclosed in U.S. Patent No. 5,448,332, which uses an oblique incidence method.

[0071] Position measurement system 30, such as Figure 2 (B) and Figure 3 The image shows a read head 32 fixed to the platform 12 within a recess formed on the platform 12. The upper surface of the read head 32 is opposite to the lower surface of the slider 10 (the forming surface of the grating RG1). A predetermined gap (or void, gap) is formed between the upper surface of the read head 32 and the lower surface of the slider 10, for example, a gap of several millimeters.

[0072] The first position measurement system 30, such as Figure 6As shown, the system includes an encoder system 33 and a laser interferometer system 35. The encoder system 33 provides multiple beams from the read head 32 to the measuring section (forming surface of the grating RG1) below the slider 10, and can receive multiple return beams (e.g., multiple diffracted beams from the grating RG1) from the measuring section below the slider 10 to obtain position information of the slider 10. The encoder system 33 includes an X linear encoder 33x for measuring the X-axis position of the slider 10, and a pair of Y linear encoders 33ya and 33yb for measuring the Y-axis position of the slider 10. The encoder system 33 uses a diffraction interferometer type read head with the same configuration as the encoder read heads (hereinafter appropriately referred to as read heads) disclosed in, for example, U.S. Patent No. 7,238,931 and U.S. Patent Application Publication No. 2007 / 288,121. In addition, the read head includes a light source and a light receiving system (including a photodetector), as well as an optical system. In this embodiment, as long as at least the optical system is disposed inside the housing of the read head 32 opposite to the grating RG1, at least one of the light source and the light receiving system can be disposed outside the housing of the read head 32.

[0073] Figure 4 (A) is a stereoscopic image of the head section 32. Figure 4 Image B is a top view of the read head 32 as seen from the +Z direction. The encoder system 33 measures the position of the slider 10 in the X-axis direction using one X read head 37x, and measures the position in the Y-axis direction using a pair of Y read heads 37ya and 37yb (see reference). Figure 4 (B) That is, the X-reader 37x, which measures the X-axis position of the slider 10 by using the X-diffraction grating of grating RG1, constitutes the X-linear encoder 33x, and a pair of Y-readers 37ya and 37yb, which measure the Y-axis position of the slider 10 by using the Y-diffraction grating of grating RG1, constitute a pair of Y-linear encoders 33ya and 33yb.

[0074] like Figure 4 (A) and Figure 4 As shown in (B), the X-head 37x is equidistant from two points on the straight line LX parallel to the X-axis passing through the center of the read head 32 and the straight line CL parallel to the Y-axis passing through the center of the read head 32 (refer to...). Figure 4 The white circle in (B) will measure beams LBx1 and LBx2. Figure 4 The same illumination point on the grating RG1 is shown by a solid line in (A). The illumination points of the measurement beams LBx1 and LBx2 are the detection points of the X-reader 37x (refer to...). Figure 4 The symbol DP in (B) is positioned in the X-axis and Y-axis directions, which are consistent with the detection center of the mark detection system MDS.

[0075] Here, the measurement beams LBx1 and LBx2 are polarized and separated by a beam splitter (not shown) from the light source. When the measurement beams LBx1 and LBx2 illuminate the grating RG1, these measurement beams LBx1 and LBx2 are diffracted at a predetermined number, such as the first diffracted beam (first diffracted beam), by passing through a lens (not shown) and a quarter-wave plate, and are reflected by a mirror. Because the polarization direction is rotated by 90 degrees by the second quarter-wave plate, they are injected again into the beam splitter through the original optical path and combined into a coaxial beam. The position of the slider 10 in the X-axis direction is measured by receiving the interference light of the first diffracted beams of measurement beams LBx1 and LBx2 with a photodetector (not shown).

[0076] like Figure 4 As shown in (B), a pair of Y-reading heads 37ya and 37yb are respectively configured on the +X side and -X side of the straight line CL. Figure 4 (A) and Figure 4 As shown in (B), the Y-reader 37ya is located on the straight line LYa from two points equidistant from the straight line LX (refer to...). Figure 4 The white circle in (B) illuminates the common illumination point on grating RG1 as follows: Figure 4 In diagram (A), the measurement beams LBya1 and LBya2 are shown by dashed lines. The illumination points of the measurement beams LBya1 and LBya2 are the detection points of the Y-reading head 37ya. Figure 4 In (B), the symbol DPya is used.

[0077] Y-reader 37yb, about the straight line CL, from the two points symmetrical to the emission points of the measurement beams LBya1 and LBya2 of Y-reader 37ya (refer to...). Figure 4 The white circle in (B) illuminates the common illumination point DPyb on the grating RG1 with measurement beams LByb1 and LByb2. Figure 4 As shown in (B), the detection points DPya and DPyb of the Y-readers 37ya and 37yb are arranged on the straight line LX parallel to the X-axis.

[0078] The measurement beams LBya1 and LBya2 are also the same beam that has been polarized and separated by a beam splitter. The interference light of these measurement beams LBya1 and LBya2 after a predetermined number of diffractions, such as the first diffraction beam (the second diffraction beam), is photoelectrically detected by a photodetector (not shown) to measure the position of the slider 10 in the Y-axis direction. Similarly, the interference light of the first diffraction beam (the second diffraction beam) of measurement beams LByb1 and LByb2 is photoelectrically detected by a photodetector (not shown) to measure the position of the slider 10 in the Y-axis direction.

[0079] Here, the control device 60 determines the position of the slider 10 in the Y-axis direction based on the average of the measurement values ​​from the two Y-reading heads 37ya and 37yb. Therefore, in this embodiment, the midpoint DP of the detection points DPya and DPyb is used as the actual measurement point to measure the position of the slider 10 in the Y-axis direction. The midpoint DP coincides with the illumination point of the measurement beams LBx1 and LBx2 on the grating RG1.

[0080] 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. This detection point is controlled by the control device 60 based on the relative position information of the mark detection system MDS (measurement unit 40) and the platform 12 measured by the second position measurement system 50, so that the actuators of the three vibration damping devices 14 are aligned with the detection center of the mark detection system MDS in the XY plane. Therefore, in this embodiment, when measuring the alignment marks on the wafer W mounted on the slider 10 by using the encoder system 33, the control device 60 can always measure the position information of the slider 10 in the XY plane below the detection center of the mark detection system MDS (on the back side of the slider 10). In addition, the control device 60 measures the rotation amount of the slider 10 in the θz direction based on the difference between the measurement values ​​of a pair of Y read heads 37ya and 37yb.

[0081] The laser interferometer 35 can direct a length-measuring beam into the measuring section (the surface on which the grating RG1 is formed) below the slider 10 and receive its reflected beam (e.g., reflected light from the surface on which the grating RG1 is formed) to obtain the position information of the slider 10. Figure 4 As shown in (A), the laser interferometer system 35 directs four length-measuring beams LBz1, LBz2, LBz3, and LBz4 onto the underside of the slider 10 (the surface on which the grating RG1 is formed). The laser interferometer system 35 includes laser interferometers 35a to 35d (see reference) that respectively illuminate these four length-measuring beams LBz1, LBz2, LBz3, and LBz4. Figure 6 In this embodiment, four Z-reading heads are formed by laser interferometers 35a to 35d.

[0082] In the laser interferometer system 35, such as Figure 4 (A) and Figure 4As shown in (B), four length-measuring beams LBz1, LBz2, LBz3, and LBz4 are emitted from four points corresponding to the vertices of a square with two sides parallel to the X-axis and two sides parallel to the Y-axis, centered on the detection point DP, and parallel to the Z-axis. In this case, the emission points (irradiation points) of length-measuring beams LBz1 and LBz4 are on the line LYa and equidistant from the line LX, while the emission points (irradiation points) of the remaining length-measuring beams LBz2 and LBz3 are on the line LYb and equidistant from the line LX. In this embodiment, the surface on which the grating RG1 is formed also serves as the reflecting surface for each length-measuring beam from the laser interferometer system 35. The control device 60 uses the laser interferometer system 35 to measure information about the position of the slider 10 in the Z-axis direction and the rotation in the θx and θy directions. Furthermore, as explained above, although the slider 10 is not actively driven relative to the platform 12 in the Z-axis, θx, and θy directions by the drive system 20, its position on the platform 12 actually changes in each of these directions because it is suspended and supported on the platform 12 by the four air bearings 18 located at the four corners of the bottom surface. That is, the slider 10 is actually movable relative to the platform 12 in each of 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, the position information of the slider 10 in each of the Z-axis, θx, and θy directions is measured by the first position measurement system 30 (laser interferometer system 35).

[0083] Furthermore, to measure the Z-axis position, θx direction, and θy direction rotation information of the slider 10, it is sufficient to direct the light beam to three distinct points on the surface where the grating RG1 is formed. Therefore, only three Z-readers, such as a laser interferometer, are needed. Additionally, a wavelength-selective filter can be provided under the slider 10 to protect the grating RG1, allowing each measurement beam from the encoder system 33 to pass through the surface of the protective glass while blocking the passage of each length-measuring beam from the laser interferometer system 35.

[0084] As explained above, the control device 60 measures the position of the slider 10 in six degrees of freedom directions using the encoder system 33 and the laser interferometer system 35 of the first position measurement system 30. In this case, the optical path length of the measurement beam in the air is extremely short and approximately equal in the encoder system 33, so the influence of air fluctuations can be almost 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. In addition, the detection points of the encoder system 33 on the actual gratings RG1 in the X-axis and Y-axis directions, and the detection point of the laser interferometer system 35 on the slider 10 in the Z-axis direction, are respectively aligned with the detection center of the mark detection system MDS in the XY plane. Therefore, the so-called Abbe error caused by the offset between the detection points and the detection center of the mark detection system MDS in the XY plane will be suppressed to a substantially negligible level. Therefore, by using the first position measurement system 30, the control device 60 can measure the position of the slider 10 in the X-axis, Y-axis and Z-axis directions with high precision without Abbe error caused by the deviation of the detection point from the detection center of the mark detection system MDS in the XY plane.

[0085] However, the position of the Z-axis direction of the mark detection system MDS, which is parallel to the optical axis AX1, on the surface of the wafer W is not based on the position information of the slider 10 in the XY plane measured by the encoder system 33. 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, when the slider 10 is positioned according to the measurement values ​​of each encoder of the encoder system 33, the result will be a positioning error (a kind of Abbe error) that reflects 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 positional offset 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 pitching θx and rolling θy with simple calculations. This is taken as the offset. Based on the position information after correcting this offset by adjusting the measurement values ​​of the encoder system 33 (each encoder), the slider 10 is positioned, thus avoiding the influence of 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, can be corrected based on the aforementioned offset.

[0086] Furthermore, in the case where the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the read head 32 can be moved to avoid positioning errors caused by this tilt. That is, if 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 platform 12 holding the read head 32 can be moved according to the position information obtained using the first position measurement system 30. As described above, the platform 12 can be moved using the vibration damping device 14.

[0087] In addition, 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 used to correct the positioning error caused by the tilt.

[0088] like Figure 1 , Figure 2 (A) and Figure 2 As shown in (B), the second position measurement system 50 has a pair of read heads 52A and 52B respectively disposed below one end and the other end of the read head mounting member 51 along its long side, and scale members 54A and 54B disposed relative to the read heads 52A and 52B. The top surfaces of the scale members 54A and 54B are set at the same height as the surface of the wafer W held in the wafer holder WH. Reflective two-dimensional gratings RG2a and RG2b are formed on the top surfaces of each scale member 54A and 54B. The two-dimensional gratings (hereinafter simply referred to as gratings) RG2a and RG2b each include a reflective diffraction grating (X-diffraction grating) with a periodic direction along the X-axis and a reflective diffraction grating (Y-diffraction grating) with a periodic direction along the Y-axis. The pitch of the grid lines of the X-diffraction grating and the Y-diffraction grating is set to, for example, 1 μm.

[0089] The scale components 54A and 54B are made of a material with a low coefficient of thermal expansion, such as the zero-expansion material described above. Figure 2 (A) and Figure 2 As shown in (B), they are fixed to the platform 12 via support members 56. In this embodiment, the dimensions of the scale members 54A, 54B and the support members 56 are determined by the gap between the gratings RG2a, RG2b and the read heads 52A, 52B, which is a few millimeters apart.

[0090] like Figure 5As shown, a reading head 52A fixed below the +X side end of the reading head mounting member 51 includes an XZ reading head 58X1 with the X-axis and Z-axis as the measurement directions, and a YZ reading head 58Y1 with the Y-axis and Z-axis as the measurement directions, both housed inside the same housing. 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 two-dimensional grating RG2a) are arranged on the same straight line parallel to the Y-axis.

[0091] Regarding the reference axis LV, which is parallel to the optical axis AX1 and the Y-axis of the mark detection system MDS, another read head 52B is symmetrically arranged with read head 52A, and its configuration is the same as that of read head 52A. That is, with respect to the reference axis LV, read head 52B has XZ read head 58X2 and YZ read head 58Y2 symmetrically arranged with XZ read head 58X1 and YZ read head 58Y1, and the illumination points of the measurement beams illuminating the grating RG2b from XZ read head 58X2 and YZ read head 58Y2 are set on the same straight line parallel to the Y-axis. Here, the reference axis LV coincides with the straight line CL.

[0092] Each of the XZ reader heads 58X1 and 58X2, and the YZ reader heads 58Y1 and 58Y2, can use an encoder reader head with the same configuration as, for example, the displacement measurement sensor reader head disclosed in U.S. Patent No. 7,561,280.

[0093] Read heads 52A and 52B are configured using scale members 54A and 54B to form XZ linear encoders for measuring the X-axis position (X position) and Z-axis position (Z position) of gratings RG2a and RG2b, respectively, and YZ linear encoders for measuring the Y-axis position (Y position) and Z position. Here, gratings RG2a and RG2b are formed on top of scale members 54A and 54B, which are respectively fixed to the platform 12 via support members 56. Read heads 52A and 52B are mounted on a read head mounting member 51 integrated with the mark detection system MDS. As a result, read heads 52A and 52B measure the position of the platform 12 relative to the mark detection system MDS (the positional relationship between the mark detection system MDS and the platform 12). For convenience, the XZ linear encoder, YZ linear encoder, and XZ reader 58X1, 58X2, and YZ reader 58Y1, 58Y2 will all use the same symbols, referred to as XZ linear encoder 58X1, 58X2 and YZ linear encoder 58Y1, 58Y2 (see reference). Figure 6 ).

[0094] In this embodiment, an XZ linear encoder 58X1 and a YZ linear encoder 58Y1 are used to construct a 4-axis encoder 581 that measures the position information of the marker detection system MDS relative to the platform 12 in each of the X, Y, Z axes and θx directions (see reference). Figure 6 Similarly, using XZ linear encoder 58X2 and YZ linear encoder 58Y2, a 4-axis encoder 582 is constructed to measure the position information of the marker detection system MDS relative to platform 12 in each of the X, Y, Z axes and θx directions (see reference). Figure 6 In this case, based on the position information of platform 12 relative to the mark detection system MDS in the Z-axis direction as measured by the 4-axis encoders 581 and 582 respectively, the position information of platform 12 relative to the mark detection system MDS in the θy direction is obtained. Based on the position information of platform 12 relative to the mark detection system MDS in the Y-axis direction as measured by the 4-axis encoders 581 and 582 respectively, the position information of platform 12 relative to the mark detection system MDS in the θz direction is obtained.

[0095] Therefore, the 4-axis encoders 581 and 582 constitute a second position measurement system 50, which measures the position information of the measurement platform 12 relative to the mark detection system MDS in the 6 degrees of freedom, i.e., the relative position information of the mark detection system MDS and the platform 12 in the 6 degrees of freedom. The relative position information of the mark detection system MDS and the platform 12 in the 6 degrees of freedom measured by the second position measurement system 50 is supplied to the control device 60 in real time. The control device 60 controls the actuators of the three vibration damping devices 14 in real time according to this relative position information, so that the detection point of the first position measurement system 30 is in a desired positional relationship relative to the detection center of the mark detection system MDS. Specifically, the positions of the detection point of the first position measurement system 30 and the detection center of the mark detection system MDS in the XY plane are consistent to a certain degree (e.g., nm), 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 time, the straight line CL is consistent with, for example, the reference axis LV. Furthermore, if the detection point of the first position measurement system 30 can be controlled to a desired positional relationship relative to the detection center of the marker detection system MDS, the second position measurement system 50 may not need to measure relative position information in all directions of the 6 degrees of freedom.

[0096] Figure 6 A block diagram showing the input-output relationships of a control device 60 configured around the control system of the measuring device 100 of this embodiment. The control device 60 includes a workstation (or microcomputer), etc., and coordinates the control of all components of the measuring device 100. Figure 6 As shown, the measuring device 100 is equipped with... Figure 1The components shown are arranged together in a wafer transport system 70 within the cavity. The wafer transport system 70 is composed of, for example, a horizontal articulated robot.

[0097] Secondly, regarding the series of actions performed when processing a batch of wafers in the measuring apparatus 100 of this embodiment configured as described above, the processing algorithm of the corresponding control device 60 is used... Figure 7 The flowchart is used to illustrate this.

[0098] As a premise, the wafer W to be measured by the measuring device 100 is a 300 cm wafer. On the wafer W, multiple, for example, I (e.g., I=98), irradiation regions (hereinafter also referred to as irradiation areas) are formed in a matrix configuration by exposure prior to the previous layer. Various types of marks are provided on the dicing lines surrounding each irradiation region or on the dicing lines within each irradiation region (in the case where multiple chips are taken from one irradiation region), such as search alignment marks (search marks) for search alignment and wafer alignment marks (wafer marks) for precision alignment. These various types of marks are formed together with the dicing regions. In this embodiment, two-dimensional marks are used as search marks and wafer marks.

[0099] Furthermore, the measuring device 100 can be set to multiple measurement modes with different mark detection conditions performed by the mark detection system MDS. As one example of multiple measurement modes, mode A can be set to detect one wafer mark in each of all irradiated areas of the entire wafer, and mode B can be set to detect multiple wafer marks in all irradiated areas for the initial predetermined number of wafers in the batch, and based on the detection results of the wafer marks, determine the wafer mark to be detected for each irradiated area of ​​the remaining wafers in the batch and detect the determined wafer mark.

[0100] Additionally, the operator of the measuring device 100 inputs the information required for alignment measurement of the wafer W in advance via an input device (not shown), and stores it in the memory of the control device 60. Here, the information required for alignment measurement includes various information such as the thickness of the wafer W, the flatness information of the wafer holder WH, the design information of the irradiation area on the wafer W, and the configuration of alignment marks. Furthermore, the measurement mode setting information is also input in advance by the operator, for example, via an input device (not shown).

[0101] correspond Figure 7The processing algorithm of the flowchart begins, for example, when an operator instructs the start of measurement. At this time, a batch of wafers is stored in a wafer carrier located at a predetermined position. However, it is not limited to this. For example, when the measurement device 100 is connected inline to a substrate processing apparatus (e.g., coating, developing apparatus, etc.), it may also begin when a request for permission to start the transport of a batch of wafers is received from the control system of the substrate processing apparatus, and the first wafer is moved to a predetermined delivery position in response to the request. In addition, the term "inline connection" refers to a state of connection along the wafer (substrate) transport path, meaning that different devices are connected to each other. In this specification, the terms "inline connection" or "inline" are used in this sense.

[0102] First, in step S102, the count value i of the counter for displaying the wafer number in the batch is initialized to 1 (i←1).

[0103] In the next step S104, the wafer W is loaded onto the slide 10. This loading of the wafer W is performed under the control of the control device 60 via the wafer transport system 70 and the up-and-down moving member on the slide 10. Specifically, the wafer transport system 70 transports the wafer W from the wafer carrier (or delivery position) to above the slide 10 at the loading position, and the drive device 13 drives the up-and-down moving member to rise a predetermined amount, thereby delivering the wafer W to the up-and-down moving member. Next, after the wafer transport system 70 retracts from above the slide 10, the drive device 13 drives the up-and-down moving member to descend, thereby placing the wafer W onto the wafer holder WH on the slide 10. Then, the vacuum pump 11 is activated, and the wafer W loaded on the slide 10 is vacuum-adsorbed by the wafer holder WH. In addition, when the measuring device 100 is connected to the substrate processing device in an online manner, the wafers are sequentially transported from the wafer transport system on the substrate processing device side and placed in the delivery position.

[0104] In the next step S106, the Z-axis position (Z position) of wafer W is adjusted. Before this Z position adjustment, the control device 60 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) based on the relative position information of the mark detection system MDS and the platform 12 in the Z-axis, θy, and θx directions measured by the second position measurement system 50. The platform 12 is set so that its surface is parallel to the XY plane and the Z position is located at a predetermined reference position. The thickness of wafer W is the same. Therefore, in step S106, the control device 60 adjusts the driving force in the Z-axis direction generated by the three vibration damping devices 14, such as the internal pressure of the air dampers (the amount of compressed air), in a way that the surface of wafer W is set within a range that allows the autofocus function of the mark detection system MDS to adjust the focal position of the optical system, based on the thickness information of wafer W stored in memory, to drive the platform 12 in the Z-axis direction, thereby adjusting the Z position of the surface of wafer W. Furthermore, if the measurement unit 40 is equipped with a focal position detection system, the control device 60 can also adjust the Z position of the wafer surface based on the detection result (output) of the focal position detection system. For example, the mark detection system MDS can be equipped with a focal position detection system that detects the Z-axis position of the wafer W surface via an optical component (object optical component) at the front end. In addition, the vibration damping device 14 can be used to move the platform 12, and the slider 10 can be moved together with the platform 12 to perform the Z position adjustment of the wafer W surface based on the detection result of the focal position detection system. Alternatively, a drive system 20 configured to drive the slider 10 not only in the XY plane but also in the Z-axis direction, θx direction, and θy direction can be used to move the slider 10. In addition, the Z position adjustment of the wafer surface can also include the tilt adjustment of the wafer surface. When the drive system 20 is used to adjust the tilt of the wafer surface, there is a possibility that an error (an Abbe error) may occur due to the difference ΔZ between the Z position of the arrangement surface of the grating RG1 and the surface of the wafer W. It is sufficient to implement at least one of the above countermeasures.

[0105] In the next step S108, wafer W is searched and aligned. Specifically, for example, a marker detection system MDS is used to detect at least two search markers located on the periphery that are approximately symmetrical to the center of wafer W. The control device 60 controls the drive of the slider 10, which is driven by the drive system 20, to position each search marker within the detection area (detection field of view) of the marker detection system MDS, while acquiring measurement information from the first position measurement system 30 and the second position measurement system 50. Based on the detection signal 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 measurement information from the second position measurement system 50), the position information of each search marker is determined.

[0106] More specifically, the control device 60 calculates the position coordinates of the two search marks on the reference coordinate system based on the detection results of the mark detection system MDS (the relative positional relationship between the detection center (index center) of the mark detection system MDS obtained from the detection signal and each search mark), the measurement values ​​of the first position measurement system 30 and the second position measurement system 50 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.

[0107] Next, 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 this rotational error approximately zero. Based on this, the search and alignment of wafer W is completed. Furthermore, since wafer W is actually mounted on slider 10 in a pre-aligned state, the center position offset of wafer W is negligible, and the residual rotational error is very small.

[0108] 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 has been set, then proceed to step S112.

[0109] In step S112, the alignment measurement of the entire wafer (one-point measurement of the entire irradiation area, in other words, EGA measurement of the entire irradiation area) is performed, that is, measuring a wafer mark for each of the 98 irradiation areas. Specifically, the position coordinates of the wafer marks on the wafer W in the reference coordinate system are calculated by the control device 60 and the measurement of the position coordinates of each search mark during the search alignment, that is, the position coordinates of the irradiation area are calculated. However, in this case, unlike during the search alignment, the measurement information of the second position measurement system 50 must be used when calculating the position coordinates of the irradiation area. The reason is that, as mentioned above, the control device 60 controls the actuators of the three vibration damping devices 14 in real time according to the measurement information of the second position measurement system 50, so that the detection point of the first position measurement system 30 and the detection center of the mark detection system MDS are aligned in the XY plane, for example, at the nm level, and the surface of the wafer W on the slider 10 is aligned with the detection position of the mark detection system MDS. However, during wafer mark detection, since there is no compensation in the XY plane between the detection point of the first position measurement system 30 and the detection center of the mark detection system MDS at the nanometer level, the positional offset between the two must be considered as a bias to calculate the position coordinates of the irradiated area. For example, by using the above-mentioned bias, the calculated position coordinates of the wafer mark on the wafer W in the reference coordinate system can be corrected by correcting the detection result of the mark detection system MDS or the measurement value of the first position measurement system 30.

[0110] Here, during the measurement at one point in the full irradiation area, the control device 60 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-repeat manner to perform the measurement at one point in the full irradiation area.

[0111] In addition, if the measurement unit 40 is equipped with a focal position detection system, the control device 60 can also adjust the Z position of the wafer surface based on the detection result (output) of the focal position detection system, similar to the description in step S106.

[0112] During the alignment measurement of the entire wafer (one-point measurement of the full irradiation area) in step S112, when the slider 10 moves in the XY plane, an off-center load is applied to the platform 12. In this embodiment, the control device 60 performs feedforward control on each of 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, in a manner that can offset the effect of the off-center load. Each vibration damping device 14 individually controls the driving force generated in the Z-axis direction. Alternatively, the control device 60 may predict the off-center load acting on the platform 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 each of the three vibration damping devices 14 individually in a manner that can offset the effect of the off-center load. Furthermore, in this embodiment, since the unevenness information (hereinafter referred to as the holder flatness information) of the wafer holding surface (defined by the upper end surfaces of the majority of pins of the pin chuck) of the wafer holder WH is determined in advance through experiments, etc., when the slider 10 is moved during alignment measurement (e.g., full illumination area 1-point measurement), the control device 60 performs feedforward control on the three vibration damping devices 14 based on the holder flatness information, thereby adjusting the Z position of the platform 12 so that the area of ​​the wafer mark containing the measurement object on the wafer W surface can be quickly located within the focal depth range of the optical system of the mark detection system MDS. Additionally, either or both of the feedforward control used to counteract the eccentric load effect acting on the platform 12 and the feedforward control based on the holder flatness information may not be implemented.

[0113] Furthermore, if the magnification of the mark detection system MDS can be adjusted, it can be set to a low magnification during search alignment and a high magnification during alignment measurement. In addition, if the center position offset of the wafer W mounted on the slider 10 and the residual rotation error are small enough to be negligible, step S108 can be omitted.

[0114] 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 for the subsequent EGA calculation are detected. The sampled illumination area refers to a predetermined plurality (at least 3) of illumination areas on the wafer W, which are used for the subsequent EGA calculation. Furthermore, in the full illumination area 1-point measurement, the full illumination area on the wafer W is the sampled illumination area. After step S112, the process proceeds to step S124.

[0115] On the other hand, if the judgment in step S110 is negative, i.e., when setting to mode B, the process moves to step S114 to determine whether the count value i is less than a predetermined number K (K is a natural number satisfying 1 < K < 1, which is a predetermined number, for example, 4). Additionally, the count value i is incremented in step S128, which will be described later. If the judgment in step S114 is positive, the process moves to step S120 to perform multi-point measurement of the full irradiation area. Here, multi-point measurement of the full irradiation area refers to measuring multiple wafer markers for all irradiation areas on the wafer W. The multiple wafer markers to be measured are predetermined. For example, multiple wafer markers configured such that the shape of the irradiation area (shape error relative to an ideal lattice) can be used as measurement objects through statistical calculations. The measurement order is the same as in the case of single-point measurement of the full irradiation area in step S112, except for the number of measurement object markers, so a detailed explanation is omitted. After step S120, the process moves to step S124.

[0116] On the other hand, if the judgment in step S114 is negative, the process moves to step S116 to determine whether the count value i is less than K+1. Here, the judgment in step S116 is positive if the count value i is i≧K and i<k+1, therefore it is the case of i=K.

[0117] If the determination in step S116 is affirmative, proceed to step S118. Based on the detection results of the wafer marks on K-1 wafers (e.g., 3 wafers when K=4) of wafer W measured up to this point, determine the wafer mark to be measured in each irradiated area. Specifically, for each irradiated area, determine whether detecting one wafer mark is sufficient or whether multiple wafer marks should be detected. If the latter, determine which wafer mark to use as the detection object. For example, for each irradiated area, calculate the difference (absolute value) between the measured position and the designed position of each of the multiple wafer marks, and determine whether multiple wafer marks or one wafer mark should be detected in each irradiated area based on whether the difference between the maximum and minimum values ​​of this difference exceeds a certain threshold. If the former, determine the wafer mark to be detected by, for example, including the wafer mark with the largest and smallest difference (absolute value) between the measured position and the designed position. After step S118, proceed to step S122.

[0118] 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. Prior to this, the count value i=K, and in step S118, the wafer marker that should be used as the measurement object for each irradiated area was determined.

[0119] In step S122, the wafer markers determined in step S118 for each irradiated area to be used as the measurement objects are measured. The measurement order is the same as in step S112 for the full irradiated area measurement (1 point measurement), except for the number of measurement object markers; therefore, detailed explanation is omitted. After step S122, proceed to step S124.

[0120] As can be seen from the description so far, in mode B, the full-irradiation area multi-point measurement is performed on wafers from the 1st to the K-1th (e.g., the 3rd) in the batch, and the wafer marking determined for each irradiation area is measured on wafers from the Kth (e.g., the 4th) to the I (e.g., the 25th) based on the results of the full-irradiation area multi-point measurement of the initial K-1th (e.g., the 3rd) wafers.

[0121] In step S124, EGA calculation is performed using the wafer marker position information measured in any of steps S112, S120, and S122. EGA calculation refers to the statistical calculation, after the wafer marker measurement (EGA measurement), using the difference between the designed and measured values ​​of the position coordinates of the sampled irradiation area, and employing least squares and other statistical operations to determine the coefficients representing the relationship between the position coordinates of the irradiation area and the correction amount of those coordinates.

[0122] In this embodiment, for example, the correction amount based on the design value of the location coordinates of the irradiated area is calculated using the following model.

[0123] Formula 1

[0124]

[0125] Here, dx and dy are the correction amounts in the X-axis and Y-axis directions of the design values ​​of the position coordinates away from the irradiation area, respectively, and X and Y are the position coordinates of the irradiation area in the design of the wafer coordinate system with the center of wafer W as the origin. That is, the above equation (1) is a polynomial relating the position coordinates X and Y of each irradiation area in the design of the wafer coordinate system with the center of wafer as the origin, and is a pattern representing the relationship between the position coordinates X and Y and the correction amounts (alignment correction components) dx and dy of the position coordinates of the irradiation area. In addition, in this embodiment, since the rotation between the reference coordinate system and the wafer coordinate system is offset by the search alignment, the reference coordinate system and the wafer coordinate system are not specifically distinguished below, and will be described using the reference coordinate system as the entirety.

[0126] Using mode (1), the correction amount of the position coordinates of the irradiated area can be obtained from the position coordinates X and Y of the irradiated area of ​​the wafer W. However, in order to calculate this correction amount, the coefficients a0, a1, ..., b0, b1, ... must be obtained. After EGA measurement, based on 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 using statistical operations such as the least squares method.

[0127] After determining the coefficients a0, a1, ..., b0, b1, ... of mode (1), the position coordinates X and Y of each irradiation area (region) in the wafer coordinate system are substituted into mode (1) after the coefficients are determined, so as to obtain the correction amount dx and dy of the position coordinates of each irradiation area, that is, the true arrangement of multiple irradiation areas (regions) on the wafer W can be obtained (as a deformation component, it includes not only linear components but also nonlinear components).

[0128] If a wafer W has already been exposed, the waveform of the detection signal obtained as a measurement result may not be good for all wafer marks due to the effects of the steps up to this point. When the positions of wafer marks with poor measurement results (detection signal waveforms) are included in the above EGA calculation, the positional error of these wafer marks with poor measurement results (detection signal waveforms) will adversely affect the calculation results of coefficients a0, a1, ..., b0, b1, ...

[0129] 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 60. The control device 60 uses the positions of all wafer markers that have received the measurement results to perform the above-mentioned EGA operation. In addition, there is no particular limitation on the degree of the polynomial in the above equation (1). The control device 60 combines the result of the EGA operation with the information related to the markers used in the operation, and corresponds it to the wafer identification information (e.g., wafer number, batch number) to create an alignment history data file, which is stored in an internal or external memory device.

[0130] After the EGA calculation in step S124 is completed, proceed to step S126 to remove the wafer W from the slide 10. Under the management of the control device 60, this removal is performed by the wafer transport system 70 and the up-and-down moving components on the slide 10 in the reverse order of loading in step S104.

[0131] 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 means that the processing of all wafers in the batch has not ended, and the process returns to step S104 until the determination in step S130 becomes positive. The processing (including the determination) of steps S104 to S130 is repeated.

[0132] When the judgment in step S130 is affirmative, it means that the processing of all wafers in the batch has been completed, thus ending the series of processes in this conventional procedure.

[0133] As detailed above, according to the measurement apparatus 100 of this embodiment, the first position measurement system 30, which measures the position information of the slider 10, which mounts and holds the wafer W, in six degrees of freedom directions, detects wafer marks on the wafer W at least by the mark detection system MDS. Therefore, within the range of movement of the slider 10, a measurement beam can be continuously irradiated onto the grating RG1 from the read head 32. Thus, the first position measurement system 30 can continuously measure its position information within the full range of the XY plane in which the slider 10 moves for mark detection. Therefore, during the manufacturing stage of, for example, the measuring device 100 (including the device startup stage within a semiconductor manufacturing plant), the origin of the orthogonal coordinate system (reference coordinate system) defined by the lattice of the grating RG1 is determined by the length measuring axis of the first position measuring system 30. The absolute coordinate position of the slider 10 in the XY plane can then be obtained. Furthermore, the absolute position of the mark (not limited to search marks, wafer marks, but also including other marks, such as registration marks, etc.) on the wafer W held by the slider 10, determined by the position information of the slider 10 measured by the first position measuring system 30 and the detection results of the mark detection system MDS, can be calculated in the XY plane. In addition, the term "absolute position coordinates" in this specification refers to the position coordinates in the aforementioned reference coordinate system.

[0134] Furthermore, the measuring apparatus 100 according to this embodiment can measure the position coordinates of the marks on the wafer in the XY plane. Therefore, it can expose the bare wafer in a step-scanning or step-repeating manner using an exposure apparatus such as a scanner or stepper, which has a product marker sheet with alignment marks formed together with a rectangular pattern area and whose positional relationship with the pattern area is known. The absolute coordinates of the alignment mark image on the exposed wafer are measured by the measuring apparatus 100, which means that wafer lattice variations (e.g., variations compared to the designed wafer lattice) can be managed without using a reference wafer. The management of wafer lattice variations caused by the apparatus will be described in detail later.

[0135] Furthermore, according to the measuring apparatus 100 of this embodiment, the control device 60 controls the movement of the slider 10 driven by the drive system 20 while using the first position measuring system 30 and the second position measuring system 50 to obtain the position information of the slider 10 relative to the platform 12 and the relative position information of the mark detection system MDS with the platform 12, and uses the mark detection system MDS to obtain the position information of multiple marks formed on the wafer W. Therefore, by using the measuring apparatus 100, the position information of multiple marks formed on the wafer W can be obtained with good accuracy.

[0136] Furthermore, according to the measuring device 100 of this embodiment, the control device 60 continuously acquires the measurement information (relative position information of platform 12 and mark detection system MDS) measured by the second position measuring system 50 and controls the position of platform 12 in the 6-degree-of-freedom direction in real time via the actuators of the three vibration damping devices 14, so that the position relationship between the detection center of mark detection system MDS and the measurement point of the first position measuring system relative to the position information of detection slider 10 in the 6-degree-of-freedom direction of platform 12 is maintained at the desired level at the nm level. Furthermore, while controlling the drive of the slider 10 by the drive system 20, the control device 60 acquires measurement information (position information of the slider 10 relative to the platform 12) measured by the first position measurement system 30 and measurement information (relative position information of the platform 12 and the mark detection system MDS) measured by the second position measurement system 50. Based on the detection signal when the mark formed on the wafer W is detected using the mark detection system MDS, the measurement information obtained by the first position measurement system 30 when the mark formed on the wafer W is detected using the mark detection system MDS, and the measurement information obtained by the second position measurement system 50 when the mark formed on the wafer W is detected using the mark detection system MDS, the position information of multiple wafer marks is calculated. Therefore, by using the measurement device 100, the position information of multiple marks formed on the wafer W can be calculated with good accuracy.

[0137] Furthermore, for example, if EGA calculation is not performed using the measured mark position information, but the wafer W (wafer stage WST) position control during exposure is performed based on the measured mark position information, the measurement information obtained by the second position measurement system 50 may not be used to calculate the mark position information. However, in this case, the measurement information obtained by the second position measurement system 50 when detecting the mark formed on the wafer W using the mark detection system MDS can be offset and used to correct information about the wafer W, such as the positioning target value used to move the wafer W (wafer stage WST). Alternatively, the aforementioned offset can be considered to control the movement of the tracing plate R (tracing plate stage RST) during exposure.

[0138] Furthermore, according to the measuring apparatus 100 of this embodiment, during alignment measurement, for each of the I (e.g., 98) irradiation areas on the wafer W, the 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 obtained through statistical calculations such as the least squares method. Therefore, for the deformation components of the wafer grid, not only the linear components but also the nonlinear components can be correctly obtained. Here, the wafer grid refers to a grid formed by linking the centers of the irradiation areas on the wafer W arranged according to the irradiation partition map (data regarding the arrangement of irradiation areas formed on the wafer W).

[0139] The correction amount of the position coordinates of the irradiation area of ​​the wafer W obtained by the measuring device 100 (coefficients a0, a1, ..., b0, b1, ... in the above formula (1)) can, for example, be used for wafer positioning relative to the exposure position when the wafer W is exposed by the exposure device. However, in order to expose the wafer W with the correction amount of the position coordinates measured by the measuring device 100 by the exposure device, the wafer W must be mounted on the wafer stage of the exposure device after being removed from the slide 10. Even if the wafer holder WH on the slide 10 and the wafer holder on the wafer stage of the exposure device are of the same type, the holding state of the wafer W will 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 specifically obtained by the measuring device 100 (coefficients a0, a1, ..., b0, b1, ... in the above formula (1)), it is not possible to directly use all of these coefficients a0, a1, ..., b0, b1, ... However, the components affected by the different holding states of the wafer W in each wafer holder are considered to be low-order components (linear components) of the position coordinate correction amount of the irradiated area, which are below the first order. Higher-order components (above the second order) are hardly affected. The reason is that higher-order components are mostly considered to be components generated mainly by the deformation of the wafer W caused by the steps, and are components that are independent of the wafer holding state of the wafer holder.

[0140] Based on the above idea, the coefficients a3, a4, ..., a9, ... and b3, b4, ..., b9, ... of the higher-order components obtained by the measuring device 100 for wafer W can be directly used as the higher-order component coefficients for the position coordinate correction of wafer W in the exposure apparatus. Therefore, on the wafer stage of the exposure apparatus, only a simple EGA measurement (e.g., measurement of wafer marks at levels 3 to 16) is required to determine the linear components for the position coordinate correction of wafer W. Since the measuring device 100 is a separate device from the exposure apparatus, it does not lead to a decrease in yield during the substrate exposure process, and more position information of the marks on the substrate can be obtained.

[0141] Furthermore, if the wafer processing using the exposure apparatus, which includes the aforementioned simple EGA measurement and exposure, is performed in parallel with the wafer processing using the exposure apparatus, and the measurement apparatus 100 is used to align and measure other wafers, efficient processing can be performed with almost no reduction in wafer processing yield.

[0142] Furthermore, in the above embodiments, although either mode A or mode B is set as the measurement mode for the sake of simplicity, it is not limited to this. Mode C, which detects two or more first-order wafer marks on the full illumination area of ​​all wafers in a batch, and mode D, which detects two or more second-order wafer marks on a predetermined illumination area located at the periphery of all wafers in a batch, and detects one wafer mark for each of the remaining illumination areas, are also possible. Additionally, mode E, which selects any one of mode A, mode C, or mode D for the remaining wafers in the batch based on the detection results of the wafer marks on the first predetermined number of wafers in the batch, is also possible.

[0143] In addition, as a measurement mode of the measuring device 100, it can measure one or more wafer marks for all wafer measurement portions of the irradiated area in the batch, such as 90% or 80% of the irradiated areas, and measure one or more wafer marks for the irradiated area located in the center of the wafer that are separated by an interval.

[0144] Furthermore, although the above embodiments have described the cases where each of the gratings RG1, RG2a, and RG2b has a periodic direction in the X-axis direction and the Y-axis direction, they are not limited thereto. As long as the grid portion (two-dimensional grating) provided by the first position measurement system 30 and the second position measurement system 50 has a periodic direction in two directions that intersect each other in the XY plane.

[0145] 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 embodiments are, of course, only one example. For instance, the detection points of the marker detection system MDS and the detection center of the read head 32 may not be in the same position in at least one of the X-axis and Y-axis directions. Additionally, the configuration of the read head and the grating RG1 (grid section) of the first measurement system 30 may be reversed. That is, the read head can be provided on the slider 10, and the grid section can be provided on the platform 12. Furthermore, the first position measurement system 30 does not necessarily need to include both the encoder system 33 and the laser interferometer system 35; it can be configured using only an encoder system. An encoder system can be used to irradiate the grating RG1 of the slider 10 with a light beam from the read head and receive the returned light beam (diffracted beam) from the grating to measure the position information of the slider 10 relative to the platform 12 in six degrees of freedom directions. In this case, the configuration of the read head is not particularly limited. For example, a pair of XZ read heads can be set up to illuminate a detection beam at two points equidistant from a predetermined point on the grating RG1 along the X-axis, and a pair of YZ read heads can be set up to illuminate a detection beam at two points equidistant from a predetermined point along the Y-axis. Alternatively, a pair of 3D read heads can be set up to illuminate a detection beam at two points separated along the X-axis of the grating RG1, and an XZ read head or YZ read head can be set up to illuminate a detection beam at a point whose position is different from the above two points along the Y-axis. The first position measurement system 30 does not necessarily have to be able to measure the position information of the slider 10 relative to the platform 12 in the 6-DOF directions; it may only be able to measure position information in, for example, the X, Y, and θz directions. Furthermore, the first position measurement system for measuring the position information of the slider 10 relative to the platform 12 may be configured between the platform 12 and the slider 10.

[0146] Similarly, the configuration of the second position measurement system 50 described in the above embodiment is only one example. For example, the read heads 52A and 52B may be fixed to the side of the platform 12, while the scales 54A and 54B may be integrally provided with the mark detection system MDS. Furthermore, although the example shown is of the second position measurement system 50 having a pair of read heads 52A and 52B, it is not limited to this; the second position measurement system 50 may have only one read head, or it may have three or more. In any case, it is preferable that the second position measurement system 50 can measure the positional relationship between the platform 12 and the mark detection system MDS in six degrees of freedom. However, the second position measurement system 50 does not necessarily have to be able to measure the positional relationship in all six degrees of freedom.

[0147] Furthermore, in the above embodiment, a drive system 20 was described in which the slider 10 is suspended and supported on the platform 12 by multiple air bearings 18, and includes a first drive device 20A that drives the slider 10 in the X-axis direction and a second drive device 20B that drives the slider 10 and the first drive device 20A together in the Y-axis direction, thereby driving the slider 10 relative to the platform 12 in a non-contact state. However, it is not limited to this; the drive system 20 may also be a drive system configured to drive the slider 10 on the platform 12 in 6 degrees of freedom directions. Such a drive system may, for example, be composed of a magnetic levitation type planar motor. In this case, the air bearings 18 are not required. In addition, the measuring device 100 may not have a separate drive system for driving the platform 12 along with the vibration damping device 14.

[0148] Alternatively, a configuration can be adopted in which the slider 10 can be driven relative to the platform 12 in, for example, the X, Y, or θz directions by a planar motor of magnetic or air levitation type. In this case, it is not necessary to set up the second position measurement system 50.

[0149] Implementation Method 2

[0150] Next, regarding the second embodiment of the lithography system including the aforementioned measuring device 100, according to... Figures 8-10 Please provide an explanation.

[0151] like Figure 8 As shown, the lithography system 1000 of this second embodiment includes an exposure apparatus 200, a measuring apparatus 100, and a substrate processing apparatus 300 connected to each other. Here, the substrate processing apparatus 300 is a coating and developing apparatus (C / D), and therefore, it will be appropriately referred to as C / D 300 in the following description. The lithography system 1000 is installed in a cleanroom.

[0152] For example, as disclosed in U.S. Patent No. 6,698,944, a typical photolithography system has an inline interface between the exposure apparatus and the substrate processing apparatus (C / D), which has a wafer transport system inside the chamber for connecting the two. On the other hand, by Figure 8 As can be seen, in this second embodiment, the photolithography system 1000 replaces the online interface section and a measuring device 100 is arranged between the exposure device 200 and the C / D 300.

[0153] The lithography system 1000 includes an exposure unit 200, a C / D converter 300, and a measurement unit 100, all of which have adjacent chambers. The exposure control unit 220 of the exposure unit 200, the coating and development control unit 320 of the C / D converter 300, and the control unit 60 of the measurement unit 100 are interconnected via a local area network (LAN) 500, enabling communication between them. A memory device 400 is also connected to the LAN 500.

[0154] Exposure device 200 is, for example, a projection exposure device (scanner) using a step-scan method. Figure 9 The omitted portion constitutes the interior of the display exposure device 200.

[0155] Exposure device 200 Figure 9 The apparatus shown includes an illumination system IOP, a mark plate stage RST for holding the mark plate R, a projection unit PU for projecting an 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 these components. 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 mark detection system MDS.

[0156] The illumination system IOP includes a light source and an illumination optics system connected to the light source via a light-transmitting optics system. The optics system uses a caliper screen (masking system) to set (limit) the caliper strip R along the X-axis direction. Figure 9 The slit-shaped illumination area IAR (exposed to the paper) extends elongatedly in a direction perpendicular to the paper surface and is illuminated with approximately uniform illuminance by an illumination light (exposure light) IL. The configuration of the illumination system IOP has been 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.

[0157] The marking plate platform RST is configured in the lighting system IOP. Figure 9 Below. The marking plate stage RST can be driven by, for example, a marking plate stage drive system 211 including a linear motor, etc. Figure 9 Not shown in the image, please refer to the diagram. Figure 10 On a caliper stage platform (not shown), the device is driven slightly in the horizontal plane (XY plane) and in the scanning direction (…). Figure 9 The Y-axis direction (left and right within the paper) is driven within a predetermined travel range.

[0158] A patterned area is formed on the -Z side surface (pattern surface) of a grading plate stage RST, and a plurality of grading plates R with known positional relationships to the patterned area are formed thereon. The positional information (including rotational information in the θz direction) of the grading plate stage RST in the XY plane is continuously detected by a grading plate laser interferometer (hereinafter referred to as "grading plate interferometer") 214 via a moving mirror 212 (or a reflecting surface formed on the end face of the grading plate stage RST) with a resolution of, for example, 0.25 nm. The measurement information from the grading plate interferometer 214 is supplied to the exposure control device 220 (see reference 220). Figure 10 In addition, the position information of the above-mentioned marking plate stage RST in the XY plane can also be measured by an encoder instead of the marking plate laser interferometer 214.

[0159] The projection unit PU is configured on the grading plate stage RST. Figure 9 Below the projection unit PU. 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 tracing sheet R is arranged such that the first surface (object surface) of the projection optical system PL is substantially aligned with the pattern surface, and a wafer W coated with resist (sensor) is arranged on the second surface (image surface) side of the projection optical system PL. Therefore, when the illumination light IL from the illumination system 1OP illuminates the illumination area IAR on the tracing sheet R, a reduced image (a reduced image of a portion of the circuit pattern) of the circuit pattern of the tracing sheet R within the illumination area IAR is formed by the projection optical system PL on the area (hereinafter also referred to as the exposure area) IA on the wafer W conjugate to the illumination area IAR. By synchronously driving the scribe plate stage RST and the wafer stage WST, the scribe plate R moves relative to the illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction), and the wafer W moves relative to the exposure area IA (illumination light IL) in the scanning direction (Y-axis direction), thereby performing scanning exposure on an irradiated area (region) on the wafer W, and transferring the pattern of the scribe plate R in the irradiated area.

[0160] The projection optical system PL uses, for example, a refractive system consisting of multiple refractive optical components (lens assemblies) arranged along an optical axis AX parallel to the Z-axis, for example, 10 to 20 pieces. Among the multiple lens assemblies constituting this projection optical system PL, the multiple lens assemblies on the object surface side (the R side of the caliper) are movable lenses that can be displaced and driven by a drive component (not shown), such as a piezoelectric component, in the Z-axis direction (the optical axis direction of the projection optical system PL) and in the tilt direction relative to the XY plane (i.e., the θx and θy directions). An imaging characteristic correction controller 248 (…) Figure 9 Not shown in the image, please refer to the diagram. Figure 10Based on instructions from the exposure control device 220, each movable lens is individually driven by independently adjusting the applied voltage to each drive component, thereby adjusting various imaging characteristics (magnification, distortion, astigmatism, coma, field curvature, etc.) of the projection optical system PL. Alternatively, instead of moving the movable lenses, an airtight chamber can be provided between adjacent specific lens assemblies inside the lens barrel 240, with the gas pressure within the airtight chamber controlled by the imaging characteristic correction controller 248. Another configuration can be used where the center wavelength of the illumination light IL can be switched by the imaging characteristic correction controller 248. These configurations also allow for adjustment of the imaging characteristics of the projection optical system PL.

[0161] The wafer stage WST is driven by a stage drive system 224, which includes a planar motor or a linear motor, etc. Figure 9 (For convenience, indicated by blocks) The wafer stage platform 222 is driven with a predetermined stroke in the X-axis and Y-axis directions, and slightly driven in the Z-axis, θx, θy, and θz directions. The wafer W is held on the wafer stage WST by a wafer holder (not shown) via vacuum adsorption or other means. In this second embodiment, the wafer holder can hold a 300mm wafer. Alternatively, a stage device can be used that replaces the wafer stage WST and includes a first stage that moves in the X-axis, Y-axis, and θz directions, and a second stage that slightly moves in 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 the "second substrate holding member".

[0162] The position information (rotation information, including yaw (rotation θz in the θz direction), pitch (rotation θx in the θx direction), and roll (rotation θy in the θy direction)) of the wafer stage WST in the XY plane is continuously detected by a laser interferometer system (hereinafter referred to as the interferometer system) 218 ​​via a moving mirror 216 (or a reflecting surface formed on the end face of the wafer stage WST) with a resolution of, for example, 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.

[0163] The measurement information from the interferometer system 218 is supplied to the exposure control device 220 (see reference). Figure 10 The exposure control device 220 controls the position (including rotation in the θz direction) of the wafer stage WST in the XY plane via the stage drive system 224 based on the measurement information of the interferometer system 218.

[0164] in addition, Figure 9Although omitted in the text, the position and tilt of the wafer's W surface in the Z-axis direction are determined using a focal sensor AFS (refer to, for example, a multi-point focal position detection system based on oblique incidence disclosed in U.S. Patent No. 5,448,332). Figure 10 The measurement information from this focus sensor AFS is also supplied to the exposure control unit 220 (see reference). Figure 10 ).

[0165] Additionally, a reference plate FP is fixed on the wafer stage WST, with its surface at the same height as the surface of the wafer W. On the surface of this reference plate FP, a first reference mark is formed for base line measurement of the alignment detection system AS, and a pair of second reference marks are formed for detection by the caliper alignment detection system described later.

[0166] On the side of the lens barrel 240 of the projection unit PU, an alignment detection system AS is provided for detecting alignment marks or first reference marks formed on the wafer W. The alignment detection system AS is an image-processing type alignment sensor (FIA) that uses broadband light, such as a halogen lamp, to illuminate the mark and measures the mark position by image processing of the image of the mark. Alternatively, an image-processing type alignment detection system AS can be used instead of the image-processing type alignment detection system AS, or a diffraction interferometry type alignment system can be used in conjunction with the alignment detection system AS.

[0167] Above the grading stage RST, the exposure apparatus 200 is further provided with a pair of grading plate alignment detection systems 213, which are spaced at predetermined distances in the X-axis direction and capable of simultaneously detecting a pair of grading plate marks located at the same Y position on the grading plate R placed on the grading plate stage RST. Figure 9 Not shown in the image, please refer to the diagram. Figure 10 The detection results of the markings in the marking plate alignment detection system 213 are supplied to the exposure control device 220.

[0168] Figure 10 The block diagram illustrates the input-output relationship of the exposure control device 220. For example... Figure 10 As shown, in addition to the aforementioned components, the exposure apparatus 200 also includes a wafer transport system 270 connected to the exposure control device 220 for transporting wafers. The exposure control device 220, including a microcomputer or workstation, comprehensively controls the entire apparatus including the aforementioned components. The wafer transport system 270 is, for example, a horizontal articulated robot.

[0169] Back Figure 8Although not illustrated, 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 30 also includes a temperature control section 330 for wafer temperature adjustment. The temperature control section 330 is generally a cooling section, for example, having a flat plate (temperature control device) called a cool plate. The cool plate is cooled, for example, by circulating cooling water. Alternatively, electronic cooling utilizing the Peltier effect may be employed.

[0170] The memory device 400 includes a management device connected to the LAN 500 and an external memory component connected to the management device via a communication path such as SCSI (Small Computer System Interface).

[0171] In the lithography system 1000 of this second embodiment, the measuring device 100, the exposure device 200, and the C / D 300 are all equipped with barcode readers (not shown), and the wafer transport system 70 (see reference) Figure 6 ), wafer transport system 270 (reference) Figure 10 In the wafer transport of both the C / D internal transport system (not shown), barcode readers are used to appropriately read the identification information of each wafer, such as wafer number and batch number. For simplicity, the explanation of reading the identification information of each wafer using barcode readers is omitted below.

[0172] In the lithography system 1000, multiple wafers are processed consecutively by the exposure apparatus 200, the C / D apparatus 300, and the measurement apparatus 100 (hereinafter, also appropriately referred to as the three apparatuses 100, 200, and 300). In the lithography system 1000, in order to maximize the overall throughput of the system, the overall processing sequence is determined, for example, in a manner in which the processing times of other apparatuses completely overlap with the processing times of the apparatus that requires the most processing time.

[0173] The following describes the operation flow when the lithography system 1000 continuously processes multiple wafers.

[0174] First, the first wafer (W1) is removed from the wafer carrier located in the C / D 300 chamber by a C / D internal transport system (e.g., a horizontal articulated robot) and transported to the coating section. Thereupon, the coating section begins applying resist. When the resist coating is complete, the C / D internal transport system removes wafer W1 from the coating section and transports it to the baking section. Thereon, heat treatment (PB) of wafer W1 begins in the baking section. Next, when PB is complete, wafer W1 is removed from the baking section by the C / D internal transport system and transported to the temperature control section 330. Thereon, cooling of wafer W1 begins via a cooling plate inside the temperature control section 330. This cooling is performed at a temperature that will not affect the exposure apparatus 200, generally, for example, the target temperature of the air conditioning system of the exposure apparatus 200, which is determined in the range of 20 to 25°C. Generally, at the point when the wafer is moved into the temperature control unit 330, the wafer temperature system is within ±0.3 [°C] relative to the target temperature, and the temperature control unit 330 adjusts the temperature to within ±10 [mK] of the target temperature.

[0175] Next, when cooling (temperature adjustment) is completed in the temperature adjustment unit 330, the wafer W1 is placed by the C / D internal transfer system onto the first substrate transfer unit located between the C / D 300 and the measuring device 100.

[0176] Within the C / D300, the same series of processes described above—resist coating, photopolymerization (PB), cooling, and wafer transport—are performed sequentially, with the wafers being placed onto the first substrate transport unit. Furthermore, by providing two or more coating units and an in-C / D transport system within the C / D300 chamber, parallel processing of multiple wafers can be performed, thereby shortening the time required for pre-exposure processing.

[0177] In the measuring apparatus 100, the pre-exposure wafer W1, which is sequentially placed on the first substrate transport section by the C / D internal transport system, is loaded onto the slide 10 in the order previously described in the first embodiment through the joint operation of the wafer transport system 70 and the up-and-down moving members on the slide 10. After loading, the measuring apparatus 100 performs wafer alignment measurement in the set measurement mode, and the control device 60 calculates the position coordinate correction amount of the irradiation area of ​​the wafer W (coefficients a0, a1, ..., b0, b1, ... in the above formula (1)).

[0178] The control device 60 associates the correction amount of the calculated position coordinates (coefficients a0, a1, ..., b0, b1, ... in the above formula (1), the information of the wafer markers that used the marked position information to calculate the correction amount, the information of the measurement mode, and the information of all wafer markers with good detection signals, with the identification information (wafer number, batch number) of the wafer W1 to form alignment history data (file), and stores it in the memory device 400.

[0179] Subsequently, the wafer W1, after alignment measurement, is placed by the wafer transport system 70 into the loading-side substrate placement section of the second substrate transport section near the measurement device 100 inside the chamber of the exposure apparatus 200. Here, the second substrate transport section is provided with a loading-side substrate placement section and a removal-side substrate placement section.

[0180] Subsequently, in the measuring device 100, the second and subsequent wafers are repeatedly aligned, aligned history data (files) are generated, and wafers are transferred in the same order as wafer W1.

[0181] The wafer W1, placed on the mounting side substrate mounting section, is transported by the wafer transport system 270 to a predetermined standby position inside the exposure apparatus 200. However, the first wafer W1 is not in standby position but is immediately loaded onto the wafer stage WST by the exposure control device 220. The exposure control device 220 loads this wafer using a (not shown) up-and-down moving member on the wafer stage WST and the wafer transport system 270 in the same manner as described in the measurement apparatus 100. After loading, the wafer on the wafer stage WST is aligned using the alignment detection system AS in the same way as described above, and wafer alignment is performed, for example, using an EGA method with an irradiation area of ​​degree 3 to 16 as the alignment irradiation area. During wafer alignment in this EGA mode, the exposure control device 220 of the exposure apparatus 200 searches the alignment history data file stored in the memory device 400, using the wafer alignment and the identification information (e.g., wafer number, batch number) of the wafer to be exposed (target wafer) as keywords to obtain the alignment history data of the target wafer. Furthermore, after a predetermined preparation operation, the exposure control device 220 performs the following wafer alignment based on the measurement mode information contained in the obtained alignment history data.

[0182] First, the case containing information of mode A will be explained. In this case, the wafer marker corresponding to the number of alignment irradiation areas is selected as the detection object from the wafer markers whose position information was measured by the measuring device 100 (the position information of the marker was used in the calculation of the correction amount) included in the alignment history data. The wafer markers of the detection object are detected by the alignment detection system AS, and the position information of each wafer marker of the detection object is obtained based on the detection result and the position of the wafer stage WST during the detection (measurement information measured by the interferometer system 218). The EGA operation is performed using the position information to obtain the coefficients of equation (2).

[0183] Formula 2

[0184]

[0185] 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 alignment history data, and uses a polynomial related to the position coordinates X and Y of each irradiation area in the wafer coordinate system with the wafer center as the origin, expressed by the equation (3) containing the replaced coefficients, to calculate the correction amount (alignment correction component) dx and dy of the position coordinates of each irradiation area. Based on this correction amount, the target position (hereinafter, for convenience, the positioning target position) used to correct the wafer lattice for positioning the exposure position (projection position of the tracing pattern) during exposure in each irradiation area is determined. In addition, in this embodiment, exposure is performed by scanning exposure instead of static exposure, and for convenience, it is referred to as the positioning target position.

[0186]

Formula 3

[0187]

[0188] In addition, by searching and aligning in the exposure apparatus 200, the rotation of the reference coordinate system (stage coordinate system) and the wafer coordinate system that determine the movement of the wafer stage WST is offset, so there is no need to distinguish between the reference coordinate system and the wafer coordinate system.

[0189] Next, the case of setting mode B will be explained. In this case, the exposure control device 220 determines the positioning target position of each irradiation area of ​​the wafer lattice to be corrected in the same order as in mode A. However, in this case, the wafer markers whose detection signals are good, which are among the multiple wafer markers for several irradiation areas and one wafer marker for each of the remaining irradiation areas, are used as the position information of the markers used when calculating the correction amount.

[0190] Therefore, in addition to determining the positioning target position of each of the aforementioned irradiation areas, the exposure control device 220 selects from multiple wafer markers for the aforementioned irradiation areas the number of wafer markers required to determine the shape of the irradiation area. Using the position information (measured values) of these wafer markers, it performs a statistical calculation using the least squares method (also known as multi-point EGA calculation within the irradiation area) in the mode disclosed in, for example, [Equation 7] of U.S. Patent No. 6,876,946, to determine the shape of the irradiation area. Specifically, it determines the chip rotation (θ), chip orthogonality error (w), and chip calibration (rx) in the x-direction and chip calibration (ry) in the mode of [Equation 7] disclosed in U.S. Patent No. 6,876,946, among the 10 parameters. Furthermore, since the multi-point EGA calculation within the irradiation area has been disclosed in detail in the aforementioned U.S. Patent, a detailed description is omitted.

[0191] Next, the exposure control device 220 controls the position of the wafer stage WST while exposing each irradiated area on the wafer W1 in a step-scan manner based on the positioning target position. Here, when the shape of the irradiated area has been determined using multi-point EGA measurement within the irradiated 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 with respect 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 done to deform the projected image of the pattern on the tracing plate R generated by the projection optical system PL in accordance with the determined irradiated area shape. 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 via the imaging characteristic correction controller 248.

[0192] In parallel with the EGA wafer alignment and exposure of the wafer (wafer W1) on the wafer stage WST, the measuring device 100 performs wafer alignment measurement and alignment history data generation on the second wafer (wafer W2) in the sequence set in the predefined mode.

[0193] Before the exposure of the wafer (W1) on the wafer stage WST is completed, the measurement processing of the measurement device 100 is completed. The second wafer W2 is placed on the loading side substrate placement part by the wafer transport system 70 and transported to the predetermined standby position inside the exposure device 200 by the wafer transport system 270, where it stands still.

[0194] When the exposure of wafer W1 is finished, wafer W1 and wafer W2 are swapped on the wafer stage, and the same wafer alignment and exposure are performed on the swapped wafer W2. Furthermore, if wafer W2 is not moved to the standby position before the exposure of the wafer on the wafer stage (in this case, wafer W1) is finished, the wafer stage remains in standby position near the standby position while holding the exposed wafer.

[0195] In parallel with the wafer alignment of the replaced wafer W2, the exposed wafer W1 is transported by the wafer transport system 270 to the removal side substrate placement section of the second substrate transport section.

[0196] Subsequently, as described above, the wafer transport system 70 and the measuring device 100 perform wafer alignment measurements in parallel and in a predetermined sequence, repeatedly performing actions such as transporting the exposed wafer from the removal-side substrate mounting section and placing it on the first substrate transport section, and removing the measured wafer from the slide 10 and transporting it to the loading-side substrate mounting section.

[0197] As described above, the exposed wafer, transported by the wafer transport system 70 and placed on the first substrate transport section, is transported into the baking section by the C / D internal transport system, where PEB is performed by the baking apparatus. Multiple wafers can be stored simultaneously in the baking section.

[0198] On the other hand, the wafer that has completed PEB is taken out of the baking section by the C / D internal transport system and moved into the developing section, where the developing device begins development.

[0199] Once the development of the wafer is complete, the wafer is removed from the developing section by the C / D internal transport system and placed into a designated storage layer within the wafer carrier. Subsequently, within the C / D300, subsequent wafers that have completed exposure undergo PEB, development, and wafer transport in the same sequence as wafer W1.

[0200] As explained above, the lithography system 1000 and the exposure apparatus 200 of this second embodiment can perform wafer alignment measurements using the measuring device 100 in parallel, and the wafer alignment and exposure operations of the full illumination area EGA (with the full illumination area as the sampling illumination area) and the exposure apparatus 200 can be performed in parallel. Furthermore, since the coefficients of the higher-order components in the pattern obtained from the full illumination area EGA can also be directly used in the exposure apparatus 200, the exposure apparatus 200 only needs to perform alignment measurements with several illumination areas as alignment illumination areas to obtain the coefficients of the lower-order components of the above pattern. By using these lower-order component coefficients and the higher-order component coefficients obtained by the measuring device 100, the positioning target position during exposure of each illumination area can be calculated with the same good accuracy as when the exposure apparatus 200 obtains the lower-order and higher-order component coefficients of pattern (1). Therefore, without reducing the throughput of the exposure apparatus 200, the overlap accuracy between the image of the tracing pattern during exposure and the pattern formed in each illumination area on the wafer can be improved.

[0201] Furthermore, in the lithography system 1000 of the second embodiment described above, the case where the low-order component coefficients of the above-described pattern (order 1 or less) are obtained for the exposure apparatus 200, and the case where these low-order component coefficients are used together with the high-order component coefficients of the above-described pattern (order 2 or more) obtained by the measurement apparatus 100 has been described. However, it is not limited to this. For example, the coefficients of the low-order components of the above-described pattern can be obtained from the detection results of the alignment marks in the exposure apparatus 200, and these low-order component coefficients can be used together with the high-order component coefficients of the above-described pattern (order 3 or more) obtained by the measurement apparatus 100. Alternatively, for example, the coefficients of the low-order components of the above-described pattern can be obtained from the detection results of the alignment marks in the exposure apparatus 200, and these low-order component coefficients can be used together with the high-order component coefficients of the above-described pattern (order 4 or more) obtained by the measurement apparatus 100. That is, the coefficients of the components of the above-mentioned pattern at order (N-1) (where N is an integer greater than or equal to 2) can be obtained from the detection results of the alignment marks in the exposure apparatus 200, and the coefficients of the components of the above-mentioned pattern at order (N-1) and above can be used together with the coefficients of the components of the above-mentioned pattern at order N and above obtained by the measuring apparatus 100.

[0202] Furthermore, in the lithography system 1000, when the measurement unit 40 of the measurement device 100 is equipped with the multi-point focus position detection system, the flatness measurement (also known as focus mapping) of the wafer W can be performed by the measurement device 100 together with the wafer alignment measurement. In this case, by using the flatness measurement result, the focus and leveling control of the wafer W during exposure can be performed without performing flatness measurement by the exposure device 200.

[0203] Furthermore, although the object is set to a 300mm wafer in the second embodiment described above, it is not limited to this and can also be a 450mm wafer with a diameter of 450mm. Since the wafer can be aligned separately from the exposure apparatus 200 using the measurement apparatus 100, even with a 450mm wafer, there will be no reduction in exposure processing yield, and it is possible to perform, for example, full-spot EGA measurements.

[0204] Furthermore, although the illustration is omitted, in the lithography system 1000, the exposure apparatus 200 and the C / D 300 can be connected, and the measuring apparatus 100 can be positioned on the opposite side of the C / D 300 from the exposure apparatus 200. In this case, the measuring apparatus 100 can be used, for example, for the same alignment measurement (hereinafter referred to as pre-measurement) on the wafer before resist coating. Alternatively, the measuring apparatus 100 can be used for the position offset measurement of the overlap offset measurement mark on the wafer after development (overlap offset measurement), and can also be used for both pre-measurement and overlap offset measurement.

[0205] Change management of wafer lattice

[0206] Secondly, the method for managing the wafer lattice caused by the exposure apparatus using the measuring device 100 will be explained using the lithography system 1000 as an example. Figure 11 The image briefly illustrates the processing flow in the wafer lattice management method at this time.

[0207] First, in step S202, the bare wafer (referred to as wafer W0 for convenience) is exposed using a step-scan method with a product marking sheet R by the exposure apparatus 200. Here, on the marking sheet R, markings (which are transferred onto the wafer to become wafer marks) are formed in the surrounding area or inside the pattern area (when multiple chips are taken in one irradiation area) along with the patterned surface and rectangular patterned area. Here, wafer W0 is an unexposed wafer, and its surface is coated with resist (photoresist) with C / D300. Therefore, during the exposure of wafer W0, no alignment is performed, and the exposure control device 220 drives the marking sheet stage RST and the wafer stage WST according to the design values. Through the exposure in step S202, a latent image is formed on the photoresist layer on the surface of wafer W0, consisting of I (e.g., 98) rectangular patterned areas arranged in a matrix, and the positional relationship of each irradiation area corresponds to the marks of each irradiation area known in the design.

[0208] Next, in step S204, the exposed wafer W0 is removed 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 the wafer transport system 70 and placed on the first substrate transport section located between the C / D 300 and the measuring device 100. Then, the wafer W0 is moved into the developing section of the C / D 300 by the C / D internal transport system.

[0209] Next, in step S206, the wafer WO is developed by the developing apparatus of the developing section of C / D300. After this development, a photoresist image (hereinafter referred to as wafer mark) of each of the wafer WO, consisting of I (e.g., 98) rectangular irradiation areas arranged in a matrix and corresponding to wafer marks of each irradiation area in a design known in terms of positional relationship, is formed on the wafer WO.

[0210] Next, in step S208, the developed wafer WO is removed from the C / D 300 and loaded onto the slider 10 of the measuring device 100. Specifically, the wafer WO is removed from the developing section by the C / D internal transport system and placed on the first substrate transport section. The wafer WO is then transported from the first substrate transport section to above the slider 10 at the loading position by the wafer transport system 70 of the measuring device 100, and loaded onto the slider 10.

[0211] Next, in step S210, the control device 60 performs a full-area measurement of the developed wafer W0 to determine the absolute position coordinates of each wafer mark. Specifically, the control device 60 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 one wafer mark corresponding to each of the I (e.g., 98) irradiation areas. Based on the detection results of each wafer mark and the absolute position coordinates (X, Y) of the slider 10 at the time of detection of each wafer mark, the absolute position coordinates (X, Y) of each wafer mark in each of the I irradiation areas on the corresponding wafer W0 are determined. At this time, the control device 60 calculates the absolute position coordinates (X, Y) of I wafer marks by 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 offsets based on the θx and θy directions of the slider 10 measured by the first position measurement system 30.

[0212] Next, in step S212, the control device 60 uses the obtained absolute position coordinates of the I markers to calculate the variation information of the arrangement (wafer lattice) of the I irradiation areas on the wafer W0. For example, based on the known positional relationship between the wafer markers and the center of the irradiation area, the control device 60 calculates 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 uses statistical operations such as the least squares method to calculate the coefficients a0, a1, ..., b0, b1, ... of the equation (1) 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. Here, the calculated coefficients a0, a1, ..., b0, b1, ... are substituted into the equation (1), and the equation (1) after the coefficients are determined is stored in the internal memory (or memory device 400) as the variation information of the wafer lattice.

[0213] Alternatively, the control device 60 calculates 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 based on the known positional relationship between the wafer marks and the center of the irradiation area. It then creates a graph of the difference between the measured values ​​of the absolute position coordinates (X, Y) of each of the I irradiation areas and the designed values ​​of the position coordinates (X, Y) of each irradiation area. This graph is stored in memory (or memory device 400) as the change information of the wafer lattice.

[0214] In this way, the variation between the wafer lattice and the design value can be calculated at any time, and the variation can be managed.

[0215] The next step, S214, is performed as needed. In step S214, the control device 60 compares the variation information of the wafer lattice difference between the design value obtained in step S210 with the variation information of the wafer lattice as a reference stored in memory (or memory device 400) beforehand, and calculates the amount of wafer lattice variation due to the variation of the reference wafer lattice. Through this step S214, errors in the arrangement of irradiation areas caused by errors in the stage lattice between different exposure devices, or errors in the arrangement of irradiation areas caused by errors in the stage lattice at different times within the same exposure device, can be managed.

[0216] If it is the former, before the processing in step S214, another bare wafer different from wafer W0 is exposed using a caliper R with a scanning stepper different from the exposure device 200, in the same way as step S202. The exposed wafer is then processed in the same way as steps S204 to S212 to obtain the change information of the wafer lattice as a reference and store it in the memory (or memory device 400).

[0217] If it is the latter, before the processing in step S214, the same processing as steps S202 to S208 is performed on another wafer that is different from wafer W0 to obtain the change information of the wafer lattice as a reference and store it in the memory (or memory device 400).

[0218] As can be seen from the above description, in the management method of this embodiment, the changes in the wafer lattice caused by the management device can be managed without using a reference wafer. Therefore, the following adverse situations that occur when using a reference wafer can be avoided.

[0219] In other words, the use of reference wafers involves rotating them across multiple exposure units, thus requiring coordination. Reference wafers are typically fabricated in multiple units, not just one, necessitating strict control over their individual characteristics. Furthermore, reference wafers can be damaged or gradually degrade over time. Moreover, in the management methods for wafer lattices using reference wafers, the surface of the reference wafer is coated with resist before exposure, followed by stripping the resist and cleaning the wafer after necessary processing. Repeating this process can potentially create scratches on the surface. Additionally, traces of the chuck components (pin chuck, etc.) used in wafer holding devices may appear on the back of the reference wafer, causing adhesion deformation and resulting in wafer lattice deformation.

[0220] On the other hand, not using a reference wafer also has the following advantages.

[0221] A. It eliminates the need to consider the absence and serial number of the reference wafer, allowing measurement (correction) to be performed when changes in the wafer lattice need to be measured (to make corrections).

[0222] B. Because it can replace the reference wafer and use a bare wafer, quality management can be easily carried out.

[0223] C. Wafer lattice management is possible using the product illumination zoning map and product marker pieces. That is, the wafer lattice can be managed using overlapping measurement marks or alignment marks attached to the product marker pieces. As a result, dedicated marker pieces for quality management are unnecessary. Furthermore, since quality management can be performed through the product illumination zoning map itself, it is possible to measure not only location-dependent errors but also variations in the wafer lattice caused by scanning speed, acceleration, and all other errors resulting from the product exposure process. Therefore, corrections can be made based on these measurement results, completely eliminating any compromises previously mentioned.

[0224] In the lithography system 1000 of this second embodiment, for example, without excessively reducing the overall wafer processing yield of the lithography system 1000, the developed wafer can be reloaded onto the slider 10 of the measuring device 100 in the same order as the pre-exposure wafer after PB, and the position offset measurement of the overlapping offset measurement marks (e.g., box-in-box marks) formed on the wafer can be performed. That is, since the measuring device 100 can perform absolute value measurement of the marks on the wafer (in the reference coordinate system based on the first position measurement system 30), it is suitable not only for wafer alignment measurement, but also for measuring devices used to perform position offset measurement of overlapping offset measurement marks as a type of relative position measurement.

[0225] Overlap Measurement

[0226] Next, the overlapping measurement method using the measuring device 100 will be explained using the case of the lithography system 1000 as an example. Figure 12 The diagram briefly illustrates the processing flow in the overlapping measurement method at this point.

[0227] First, in step S302, in the coating section of C / D300, a wafer (let's call it wafer W) that has undergone the first layer (bottom layer) exposure by an exposure device different from the exposure device 200, such as a scanner or a stepper, is coated. 11 The photoresist (resist) is applied to the wafer before photoresist coating. 11 In this process, through the exposure of the underlying layer and together with multiple, for example, I (I being 98) irradiation areas, wafer markers with known design positional relationships to the irradiation areas and a first marker for overlapping offset measurement (more precisely, a photoresist image of the first marker (also appropriately called a first marker image)) are formed in a manner corresponding to each irradiation area. In this case, the design positional relationships of each of the I first marker images are also known.

[0228] Secondly, in step S304, the wafer W coated with photoresist is...11 After undergoing the same predetermined processing as the wafer W1, it is mounted on the wafer stage WST of the exposure apparatus 200. Specifically, after heat treatment (PB) in the baking section, temperature adjustment in the temperature control section 330, and alignment measurement (here, A-mode measurement) performed by the measuring device 100, the wafer W1... 11 It is loaded onto the wafer stage (WST).

[0229] Next, in step S306, the exposure control device 220 of the exposure apparatus 200 exposes the wafer W on the wafer stage WST. 11 The same search alignment as described above is performed using an alignment detection system AS, and wafer alignment in the EGA manner, for example, with an irradiation area of ​​degree 3 to 16 as the alignment irradiation area.

[0230] Secondly, in step S308, the exposure control device 220 calculates the correction amount (alignment correction component) dx, dy of the position coordinates of each irradiation area expressed by the formula (3) based on the wafer alignment result, and determines the positioning target position of the wafer lattice during exposure in each irradiation area based on this correction amount.

[0231] Secondly, in step S310, the exposure apparatus 200 simultaneously controls the position of the wafer stage WST according to the positioning target position and simultaneously exposes the wafer W... 11 The second layer (the layer above the first layer) is exposed in each irradiation area using a step-scan method. At this time, the exposure apparatus 200 uses the corresponding wafer W. 11 The first mark on the image forms a caliper patch with the second mark (for convenience, let's call it caliper patch R). 11 The wafer W is exposed through this second layer of exposure. 11 The I irradiation areas overlap the transfer marking sheet R 11 The pattern area is formed and a transfer image of the second mark is formed in a positional relationship corresponding to the positional relationship of the first mark.

[0232] Secondly, in step S312, the wafer W that has completed the second layer exposure is... 11 After undergoing the same processing steps as the exposed wafer W1, it is transferred into the developing section of the C / D300. Specifically, wafer W... 11 The wafer is transported by wafer transport system 270 to the removal-side substrate placement section of the second substrate transport section, then transported by wafer transport system 70 from the removal-side substrate placement section to the first substrate transport section, and then transported by the C / D internal transport system into the baking section of C / D 300, where it undergoes PEB (Pre-Earnings Embedding) using the baking apparatus. The wafer W after PEB is completed... 11The material is removed from the baking section and moved into the developing section by the C / D internal transport system.

[0233] Next, in step S314, the wafer W on which the transfer image with multiple second marks is formed is processed by the developing apparatus in the developing section. 11 The development. Through this development, on the wafer W 11 Together with the I irradiation areas, a group of I second marker images corresponding to the first marker image is formed in a predetermined positional relationship, thus becoming the substrate to be measured during overlay measurement. That is, the substrate to be measured during overlay measurement (overlay measurement object substrate) is manufactured in this manner. Here, as the group of second marker images corresponding to the first marker image, a photoresist image of a stacked box marker, such as one consisting of an outer box marker and an inner box marker disposed inside it, can be used.

[0234] Next, in step S316, the developed wafer W 11 The substrate (of the object to be measured) is taken out from the developing section by the C / D internal transport system and placed on the first substrate transport section.

[0235] In the next step S318, the control device 60 of the measuring device 100 transports the developed wafer W placed on the first substrate transport section. 11 The (overlapping measurement target substrate) is loaded onto the slider 10 in the aforementioned order, and the absolute position coordinates in the XY plane of each of the first and second mark images in Group I are determined in the following manner. That is, the control device 60 measures the position information of the slider 10 using the first position measurement system 30 (and the second position measurement system 50), and simultaneously uses the mark detection system MDS to detect the wafer W. 11 The first and second marker images of group I are used, and based on the detection results of each of the first and second marker images of group I and the absolute position coordinates (X, Y) of the slider 10 during the detection of each marker image, the wafer W is calculated. 11 The absolute position coordinates in the XY plane of each of the first and second marker images in Group I are calculated. At this time, the control device 60 uses the Abbe errors of the first position measurement system 30 in the X and Y directions and the measurement values ​​of the second position measurement system 50 in the X and Y directions as biases to calculate the absolute position coordinates in the XY plane of each of the first and second marker images in Group I.

[0236] In the next step S320, the control device 60 calculates the overlap error (overlap offset) between the first and second layers based on the absolute position coordinates of the first and second marker images that are grouped together.

[0237] In the next step S322, the control device 60 determines, for example, whether the overlap error is caused by the exposure of the first layer or the exposure of the second layer, based on the absolute position coordinates of the I first marker images and the I second marker images. Specifically, the control device 60 calculates the offset (ΔX1) of the designed position coordinates from the absolute position coordinates of the first marker image. i ΔY1 i (i=1~I), the offset (ΔX2) from the design position coordinates of the absolute position coordinates away from the second marker image. i ΔY2 i (i=1~I), ΔX1 i ΔX2 i Regarding ΔY1 i ΔY2 i Calculate the sum ΣX1 of each i = 1 to I. i ΣX2 i ΣY1 i ΣY2 i Control device 60 in ΣX1 i >ΣX2 i And ΣY1 i >ΣY2 i In the case where it is determined that the overlap error in either the X-axis or Y-axis direction is mainly caused by the exposure of the first layer, in ΣX1 i <ΣX2 i And ΣY1 i <ΣY2 i In this case, it is determined that the overlap error in either the X-axis or Y-axis direction is mainly caused by the exposure of the second layer. Additionally, the control device 60 in ΣX1 i >ΣX2 i And ΣY1 i <ΣY2 i In the case of overlapping error, it is determined that the overlap error in the X-axis direction is caused by the exposure of the first layer being dominant, and in the Y-axis direction it is caused by the exposure of the second layer being dominant. In ΣX1 i <ΣX2 i And ΣY1 i >ΣY2 i In this case, it is determined that the overlap error is mainly caused by the exposure of the second layer in the X-axis direction, and mainly caused by the exposure of the first layer in the Y-axis direction.

[0238] In addition, the above-mentioned judgment method is just one example. As long as the control device 60 determines whether the overlap error is caused by the exposure of the first layer or the exposure of the second layer based on the absolute position coordinates of the first and second marker images, the specific judgment method is irrelevant.

[0239] As can be seen from the above description, according to the overlapping measurement method of this embodiment, the control device 60 of the measuring device 100 can measure the absolute position coordinates of the first marker image and the absolute position coordinates of the second marker image respectively. Based on these absolute position coordinates, it can be determined whether the overlapping error is caused by the exposure of the bottom layer or the exposure of the top layer, and excellent results that have not been achieved before can be obtained.

[0240] Furthermore, although the above description addresses the different situations of the exposure apparatus used for bottom layer exposure and the exposure apparatus used for top layer exposure, it is not limited to this. For example, even when the bottom layer and top layer exposure are performed by the exposure apparatus 200, the overlapping accuracy can be managed with high precision through the series of processes in steps S302 to S322 described above.

[0241] Furthermore, since the overlap error (overlap offset) between the first and second layers has already been calculated in step S320, step S322 only needs to be performed as needed.

[0242] In addition, Figure 8 In the lithography system 1000, although only one measuring device 100 is provided, multiple measuring devices can be provided as in the following variant example, such as two measuring devices.

[0243] Variations

[0244] Figure 13 The diagram schematically illustrates the configuration of a modified lithography system 2000. The lithography system 2000 includes an exposure unit 200, a C / D converter 300, and two measuring devices 100a and 100b with the same configuration as the measuring device 100. The lithography system 2000 is housed in a cleanroom.

[0245] In the lithography system 2000, two measuring devices 100a and 100b are arranged side by side between the exposure device 200 and the C / D 300.

[0246] The lithography system 2000 includes an exposure unit 200, a C / D converter 300, and measurement units 100a and 100b, which are arranged adjacent to each other in a chamber configuration. The exposure control unit 220 of the exposure unit 200, the coating and development control unit 320 of the C / D converter 300, and the control units 60 of the measurement units 100a and 100b are interconnected via a LAN 500 and communicate with each other. A memory device 400 is also connected to the LAN.

[0247] In this modified lithography system 2000, since the same sequence of operations as the lithography system 1000 can be set, the same effect as the lithography system 1000 can be obtained.

[0248] In addition, the lithography system 2000 can also employ a sequence in which both measurement devices 100a and 100b are used for alignment measurements (hereinafter referred to as post-measurement) on the wafer after PB and for the same alignment measurements (pre-measurement) on the wafer before resist coating. In this case, the pre-measurement on a specific wafer and the series of wafer processing on wafers different from that wafer are performed in parallel, so the overall system yield is hardly reduced. However, for the initial wafer, the time for pre-measurement cannot overlap with the time for the series of wafer processing.

[0249] By comparing the positions of the same wafer mark measured before and after the experiment on the same wafer, the measurement error of the wafer mark position caused by the resist coating can be determined. Therefore, by correcting the aforementioned measurement error of the wafer mark position caused by the resist coating on the positions of the same wafer marks measured when the exposure apparatus 200 aligns wafers with the same wafer, high-precision EGA measurements can be performed that compensate for the measurement error of the wafer mark position caused by the resist coating.

[0250] In this case, the measurement result of the wafer mark position will be affected by the holding state of the wafer holder, regardless of whether it is a pre-measurement or a post-measurement. Therefore, for the same wafer, it is best to use the same measurement device 100a or 100b for both pre-measurement and post-measurement.

[0251] However, one of the measuring devices 100a and 100b can be used exclusively for pre-measurement, while the other can be used exclusively for post-measurement. In this case, when the measuring devices 100a and 100b are each started, a reference wafer is mounted on each of the sliders 10. While the position of the slider 10 is measured by the first position measuring system 30, the marks on the reference wafer are detected by the mark detection system MDS. Based on the detection result, the grid of the reference wafer is determined by each of the measuring devices 100a and 100b in the same manner as in the case of the wafer WO. In this case, the reference wafer can be a wafer formed by etching or other methods with marks (any one of line and space marks, 2D grid marks, and box marks) that can be measured by the resolution of the mark detection system MDS at a specific spacing, for example, 1 mm spacing.

[0252] The coordinate systems of each of the first position measurement systems 30 are made consistent with each other to eliminate the differences between the grids of the obtained reference wafer. The reason is that the grids of the same reference wafer are originally the same, so if there is an error between the grids of the obtained reference wafer, it should be because there is an error between the reference coordinate systems of the sliders 10 of each of the measuring devices 100a and 100b.

[0253] In this case, since the coordinate systems of the reference wafers are aligned with each other during the movement of the sliders of the specified measuring devices, the required setup is only required when each measuring device is started. Compared with conventional techniques, the number of wafers required and the frequency are overwhelmingly reduced, and each measuring device only needs to measure the marks on the reference wafers, without exposing the reference wafers. That is, since there is no need to coat or strip photoresist, there is no damage to the reference wafers. The reference wafers can simply be carefully stored as standards. Furthermore, after each measuring device is started, reference wafers are generally not required.

[0254] In the lithography system 2000, the overlap offset measurement of the wafer after development can be performed instead of the pre-measurement described above. In this case, one of the measuring devices 100a and 100b can be designated for the post-measurement and the other for the overlap offset measurement. Alternatively, the post-measurement and overlap offset measurement can be performed sequentially using the same measuring device 100a or 100b for the same wafer. In the latter case, the pre-measurement can be further performed using the same measuring device for the same wafer.

[0255] Furthermore, although the icons are omitted, in the lithography system 2000, one of the measuring devices 100a and 100b can be selected, for example, measuring device 100a can be positioned on the opposite side of the C / D 300 from the exposure device 200. In this case, considering the wafer transport process, measuring device 100a is suitable for performing the overlap offset measurement of the wafer after development. Moreover, if the individual differences in the holding state of the holders between measuring devices 100a and 100b are negligible, measuring device 100a can replace overlap offset measurement for pre-measurement, or it can be used for both overlap offset measurement and pre-measurement.

[0256] In addition, three or more measuring devices 100 can be set up in addition to the exposure device 200 and C / D 300, all devices can be connected together, and two of the three measuring devices 100 can be used for pre-measurement and post-measurement, while the remaining measuring device can be used exclusively for overlap offset measurement. Alternatively, the first two can be used exclusively for pre-measurement and post-measurement, respectively.

[0257] Furthermore, in the second embodiment and its variations described above, the signal processing device 49, which processes the detection signal of the Mark Detection System MDS and includes measuring devices 100, 100a, and 100b, sends only the measurement results of wafer marks with good waveforms from the detection signal obtained as the Mark Detection System MDS to the control device 60. The control device 60 then performs EGA calculations using these wafer mark measurement results, and the exposure control device 220 performs EGA calculations using partial position information of the position information of a wafer mark selected from a plurality of wafer marks with good waveforms from the detection signal obtained as the Mark Detection System MDS. However, this is not a limitation; the signal processing device 49 may also send the measurement results of the remaining wafer marks from the detection signal obtained as the Mark Detection System MDS, after removing wafer marks with poor waveforms, to the control device 60. Alternatively, the determination of whether the detection signal obtained from the mark detection system MDS is good or bad can be performed by the control device 60 instead of the signal processing device. In this case, the control device 60 performs the EGA operation using only the measurement results of wafer marks whose detection signals are judged to be good, or the measurement results of wafer marks remaining after removing wafer marks whose detection signals are judged to be bad. Furthermore, it is preferable that the exposure control device 220 performs the EGA operation using the measurement results of a subset of wafer marks selected from the wafer mark measurement results used in the EGA operation performed by the control device 60.

[0258] Furthermore, in the second embodiment and its variations described above, the example illustrates a case where the measuring devices 100, 100a, and 100b are arranged between the exposure apparatus 200 and the C / D 300, replacing the connection interface section. However, this is not a limitation; the measuring devices (100, 100a, 100b) can be part of the exposure apparatus. For example, the measuring devices can be installed in the wafer loading section of the exposure apparatus 200 before exposure. Additionally, when the measuring devices (100, 100a, 100b) are provided as part of the exposure apparatus 200 within its chamber, the measuring devices may or may not have a chamber. Furthermore, when the measuring devices (100, 100a, 100b) are part of the exposure apparatus, the measuring devices may or may not have a control device and may be controlled by the exposure apparatus's control device. In any case, the measuring devices are connected to the exposure apparatus.

[0259] Furthermore, in the above embodiments, the case where the substrate processing apparatus is a C / D converter has been described. However, the substrate processing apparatus can be any apparatus connected to the exposure apparatus and the measurement apparatus. It can be a coating apparatus (coater) that coats a sensitizer (resist) on the substrate (wafer), or a developing apparatus (developer) that develops the substrate (wafer) after exposure. It can also be a coating apparatus (coater) and a developing apparatus (developer) that are connected to the exposure apparatus and the measurement apparatus respectively.

[0260] When the substrate processing apparatus is a coating apparatus, the measuring apparatus may be used only for the aforementioned post-measurement, or for both pre-measurement and post-measurement. In this case, the exposed wafer is transferred to a developing apparatus that is not connected to the exposure apparatus.

[0261] When the substrate processing apparatus is a developer, the measuring apparatus can be used only for the post-measurement, or for post-measurement and overlap offset measurement. In this case, the wafer, pre-coated with resist in other locations, is moved into the exposure apparatus.

[0262] In the second embodiment and its variations described above (hereinafter referred to as the second embodiment, etc.), the case where the exposure apparatus is a scanning stepper was described, but it is not limited thereto. The exposure apparatus can be a stationary type exposure apparatus such as a stepper, or it can be a reduction projection exposure apparatus of the step and stitch method that combines the irradiation areas. Furthermore, 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, the second embodiment described above can also be applied to multi-stage type exposure apparatuses having multiple wafer stages. Furthermore, the exposure apparatus is not limited to the dry exposure apparatus that exposes the wafer W without using liquid (water), but can also be an immersion exposure apparatus that exposes the substrate using 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. Additionally, the exposure apparatus is not limited to semiconductor manufacturing exposure apparatuses, but can also be, for example, liquid crystal exposure apparatuses for transferring patterns of liquid crystal display components onto square glass plates.

[0263] Furthermore, all publications, international publications, U.S. patent application publications, and U.S. patent specifications related to the exposure apparatus used in the above embodiments are incorporated herein by reference as part of this specification.

[0264] By using an exposure apparatus constituting the photolithography system described above, semiconductor components are manufactured via a photolithography step that exposes a photosensitive object using a patterned marker sheet (mask) and then develops the exposed photosensitive object. In this case, highly integrated components can be manufactured with high efficiency.

[0265] In addition to the photolithography step, the semiconductor component manufacturing process may also include steps such as designing the component's functions and performance; making a marking sheet (mask) based on this design; component assembly steps (including cutting, bonding, and packaging steps); and inspection steps.

Claims

1. A measuring apparatus for acquiring positional information of marks formed on a substrate by exposure processing of a substrate held on a substrate holder of an exposure apparatus, characterized in that, include: The first detection system detects the mark formed on the substrate; A stage that holds the substrate on a different holding member than the substrate holder and is movable; An absolute position measurement system includes a measuring surface with a grid section and a reading head that illuminates the measuring surface with a light beam. One of the measuring surface and the reading head is disposed on the stage. The reading head illuminates the measuring surface with a light beam and receives a return beam that returns from the measuring surface to obtain the position information of the stage. The control device, based on the detection results of the first detection system and the position information of the stage obtained using the absolute position measurement system, determines the position information of multiple marks corresponding to each of the multiple regions formed on the substrate through a predetermined exposure process. as well as Memory device; and The difference between the position information of the plurality of zoning regions obtained from the position information of the plurality of markers based on the known positional relationship between the plurality of markers and the center of the zoning regions, and the design position information of the zoning regions, is stored in the memory device as variation information of the wafer lattice based on each predetermined exposure process.

2. The measuring device according to claim 1, characterized in that, The difference between the position information of multiple partitioned regions formed on the other substrate, obtained from the position information of the marks formed on the other substrate that underwent the predetermined exposure process through other exposure devices different from the exposure device, and the design position information of the multiple partitioned regions formed on the other substrate, and the difference between the change information of the reference wafer lattice stored in the memory device, is used as the change information of the wafer lattice between the other exposure device and the exposure device in the predetermined exposure process.

3. The measuring device according to claim 1, characterized in that, The difference between the position information of the plurality of partitioned regions obtained from the position information of the marks formed on the substrate by the exposure apparatus at a time point different from the predetermined exposure process and the design position information of the partitioned regions, and the difference between the change information of the reference wafer lattice stored in the memory device, is used as the change information of the wafer lattice in the predetermined exposure process between the time point when the predetermined exposure process was performed and the different time points.

4. The measuring device according to claim 1, characterized in that, The variation information of the wafer lattice used as a reference is a chart composed of the difference between the location information of the plurality of zoning regions and the design location information of the zoning regions.

5. The measuring device according to claim 1, characterized in that, The variation information of the wafer lattice used as a reference is obtained by statistical calculation from the difference between the location information of the plurality of partitioned regions and the design location information of the partitioned regions.

6. The measuring device according to claim 1, characterized in that, The measuring device further includes a multi-point focal position detection system, which detects the height of the substrate surface; The control device calculates the flatness of the substrate based on the detection results of the multi-point focal position detection system and the position information of the stage obtained by using the absolute position measurement system.

7. An exposure apparatus, characterized in that, include: A substrate stage that holds the substrate on a substrate holder and is movable; as well as An exposure control device controls the substrate stage based on the change information of the wafer lattice obtained by the measuring device according to any one of claims 2 to 6. and The substrate held on the substrate holder is exposed with an energy beam.

8. A photolithography system, characterized in that, include: An exposure apparatus that forms multiple zoned areas on a substrate through an exposure process; as well as The measuring device of claim 1 measures and stores the variation information of the wafer lattice as a reference for the arrangement of the plurality of zoned regions, i.e., the wafer lattice. The wafer lattice variation information, which serves as a reference, is used for wafer lattice variation management.

9. A measurement method for obtaining positional information of marks formed on a substrate by a predetermined exposure process performed on a substrate held on a substrate holder of an exposure apparatus, characterized in that: The markings formed on the substrate are detected by the first detection system; The substrate is held on the holding member and moved by a stage having a holding member different from the substrate holding member; An absolute position measurement system is used, which has a measuring surface with a grid section and a reading head that illuminates the measuring surface with a light beam. The reading head illuminates the measuring surface with a light beam, and the system receives the return beam that returns from the measuring surface with the light beam, so as to obtain the position information of the stage on which one of the measuring surface and the reading head is provided. Based on the detection results of the first detection system and the position information of the stage obtained using the absolute position measurement system, the position information of multiple marks in each of the multiple division areas formed on the substrate is determined; and The difference between the position information of the multiple zones obtained from the position information of the multiple markers based on the known positional relationship between the multiple markers and the center of the zoned zone, and the design position information of the zoned zone, is stored as the variation information of the wafer lattice used as a reference in the predetermined exposure process.

10. The measurement method according to claim 9, characterized in that, For a substrate on which the predetermined exposure process was performed by the exposure apparatus at a time point different from the predetermined exposure process, the difference between the position information of the zoned region and the design position information of the zoned region is calculated. The difference between the difference and the variation information of the wafer lattice used as a reference is recorded as the variation information of the wafer lattice in the predetermined exposure process.

11. The measurement method according to claim 9, characterized in that, For each substrate that has undergone the predetermined exposure process in multiple exposure devices, the difference between the position information of the zoned region and the designed position information of the zoned region is calculated. The difference between the difference and the difference between the wafer lattice variation information used as a reference is recorded as the wafer lattice variation information among the plurality of exposure devices in the predetermined exposure process.

12. The measurement method according to claim 9, characterized in that, A chart is generated, consisting of the difference between the location information of the multiple zoned regions and the design location information of the zoned regions, and stored as the variation information of the wafer lattice used as a reference.

13. The measurement method according to claim 9, characterized in that, The height of the substrate surface is detected by a multi-point focal position detection system; The flatness of the substrate is determined based on the detection results of the multi-point focal position detection system and the position information of the stage obtained using the absolute position measurement system.

14. An exposure method, characterized in that, The variation information of the wafer lattice is obtained by the measurement method according to any one of claims 10 to 13; The substrate is exposed based on the changes in the wafer lattice.

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