Substrate processing system, substrate processing method, and device manufacturing method

Abstract

The measuring device (100) of the present invention includes a slider (10) that can keep a substrate (W) moving parallel to the XY plane, a drive system that drives the slider, a position measuring system (30) that can illuminate a plurality of light beams from a reading head (32) onto a measuring surface provided on the slider with a grid section (RG1) and receive the return light beams from each of the plurality of light beams from the measuring surface to measure the position information of the slider in at least 3 degrees of freedom directions including absolute position coordinates, a mark detection system (MDS) that detects marks on the substrate, and a control device that controls the drive of the slider and uses the mark detection system to detect a plurality of marks on the substrate respectively, and calculates the absolute position coordinates of each mark based on the detection result of each mark and the measurement information of the position measuring system at the time of detection.

Description

Technical Field

[0001] The present invention relates to a measuring device, a lithography system and an exposure device, as well as a management method, an overlapping measurement method and a component manufacturing method, and in particular, to a measuring device for measuring position information of a plurality of marks formed on a substrate, and an exposure device having a substrate carrier for carrying a substrate on which position information measurement of a plurality of marks by the measuring device has been completed, and a lithography system comprising the above-mentioned measuring device, and an exposure device having the above-mentioned measuring device, as well as a management method for managing changes in the arrangement of a plurality of partitioned areas on a substrate, an overlapping measurement method using a substrate as a measurement object, and a component manufacturing method using the above-mentioned lithography system or exposure device. Prior Art

[0002] In the lithography process for manufacturing semiconductor devices, multiple layers of circuit patterns are overlapped on a substrate such as a wafer or a glass plate (hereinafter collectively referred to as a wafer). If the overlap accuracy between the layers is poor, the semiconductor device cannot exhibit the predetermined circuit characteristics and may sometimes become a defective product. Therefore, generally, a mark (alignment mark) is pre-formed on each of the multiple shot areas on the wafer to detect the position (coordinate value) of the mark on the stage coordinate system of the exposure device. Afterwards, based on the mark position information and the known position information of the newly formed pattern (such as a reticle pattern), wafer alignment is performed to align one shot area on the wafer with the position of the pattern.

[0003] As a method of wafer alignment, in order to take into account the production yield, the mainstream method is the full-wafer enhanced alignment (EGA) which only detects the alignment marks of several irradiation areas (also called sampling irradiation areas or alignment irradiation areas) on the wafer and calculates the arrangement of the irradiation areas on the wafer in a statistical way.

[0004] However, in the lithography process, when overlapping exposure is performed on a wafer, the wafer that has undergone the process steps of photoresist coating, development, etching, CVD (chemical vapor deposition), CMP (chemical mechanical polishing), etc. may be deformed in the arrangement of the irradiation area of the previous layer due to the process, and this deformation may become the cause of reduced overlapping accuracy. In view of this, recent exposure devices have a grid correction function that can correct not only the primary component of the wafer, but also the nonlinear component of the arrangement of the irradiation area generated by the process (for example, refer to Patent Document 1).

[0005] In the past, the management of wafer grid changes caused by devices, for example, was performed by overlapping exposure using a dedicated grid management reticle on a reference wafer engraved with marks. Here, the so-called wafer grid refers to a grid formed by connecting the centers of shot areas on the wafer arranged according to the shot area map (data on the arrangement of shot areas formed on the wafer). In this specification, the wafer grid is also referred to as a "grid" or described as "arrangement of shot areas (or shots)".

[0006] Originally, it would be ideal to perform grid management on each irradiation area map for all irradiation area maps, but this would require countless reticles and countless wafers, so a reference wafer and the above-mentioned special reticles are used.

[0007] However, no matter how fine the marks that can be engraved on the reference wafer are, there are still limits and they are discrete, so it is difficult to manage the wafer grid using the product exposure area map of the exposure device user. In addition, grid management using the reference wafer is generally based on the following premises (assumptions) and is accompanied by some compromises. a. The grid error depends on the coordinates, and the same location has the same error. If it is near the point where the marked position is measured and the grid error correction is performed, the error is considered to be small. b. Errors in scanning speed or scanning acceleration will not cause grid errors. Even if grid errors occur, they do not change during each scan, so they only need to be adjusted once, and regular maintenance is not required. [Prior technical literature] []

[0008] [Patent Document 1] U.S. Patent Application Publication No. 2002 / 0042664 Summary of the invention

[0009] [[] [Methods to solve the problem] []]The first aspect of the present invention provides a measuring device for measuring position information of a plurality of marks formed on a substrate, comprising: a stage capable of keeping the substrate moving; a driving system for driving the stage; an absolute position measuring system, wherein one of a measuring surface having a grid portion and a reading head for irradiating a light beam to the measuring surface is disposed on the stage, wherein the light beam from the reading head is irradiated to the measuring surface, and the position information of the stage is acquired by receiving a return light beam from the measuring surface; a mark detection system for detecting marks formed on the substrate; and a control device for controlling the movement of the stage by the driving system, wherein the mark detection system is used to respectively detect the plurality of marks formed on the substrate, and the absolute position coordinates of each of the plurality of marks are calculated based on the detection results of each of the plurality of marks and the position information of the stage obtained by using the absolute position measurement system when detecting each of the plurality of marks.

[0010] The second aspect of the present invention provides a lithography system, which comprises: a measuring device of the first aspect; and an exposure device, having a substrate carrier for carrying the substrate on which the position information of the plurality of marks measured by the measuring device has been completed, alignment measurement of the position information of a selected portion of the plurality of marks on the substrate carried on the substrate carrier, and exposure of the substrate with an energy beam.

[0011] The third aspect of the present invention provides a device manufacturing method, comprising: using the lithography system of the second aspect to expose a substrate, and developing the aforementioned substrate after exposure.

[0012] The fourth aspect of the present invention provides an exposure device having the measuring device of the first aspect, which exposes a substrate having position information of a plurality of marks obtained by using the aforementioned measuring device with an energy beam.

[0013] The fifth aspect of the present invention provides a method for manufacturing an element, comprising: exposing a substrate using the exposure device of the fourth aspect, and developing the aforementioned substrate after exposure.

[0014] The sixth aspect of the present invention provides a management method for managing the change of the arrangement of a plurality of divided areas arranged in a matrix on a substrate, which includes: using an exposure device to sequentially transfer a pattern and a mark formed on a mask to a substrate to form a plurality of divided areas on the substrate together with the mark; placing the substrate formed with the plurality of divided areas on a stage that is movable within a predetermined plane and has a measuring surface with a grid portion and a read head that irradiates a light beam to the measuring surface, and using the read head to irradiate a light beam to the measuring surface with a grid portion provided on the stage and receive a return light beam of the light beam from the measuring surface to measure the packet. The absolute position measurement system containing the position information of the absolute position coordinates of the carrier in the given plane measures the position information of the carrier while using a mark detection system to respectively detect the multiple marks corresponding to each of the multiple division areas on the substrate, and calculates the absolute position coordinates of the multiple marks corresponding to each of the multiple division areas on the substrate in the given plane based on the detection results of each of the multiple marks and the measurement information of the absolute position measurement system when each of the multiple marks is detected; and calculates the arrangement information of the multiple division areas based on the obtained absolute position coordinates of the multiple marks.

[0015] The seventh aspect of the present invention provides an overlapping measurement method, which is to use a plurality of substrates formed with a predetermined position relationship as a measurement object by exposing a first layer and exposing a second layer with the first layer as the bottom layer to form a group of second mark images corresponding to the first mark image, which includes: mounting the substrate of the measurement object on a carrier having one of a measurement surface with a grid portion and a read head for irradiating a light beam to the measurement surface, while using a light beam that can irradiate the measurement surface through the read head and receive the return light beams of each of the plurality of light beams from the measurement surface to measure the absolute position coordinates of the carrier in the predetermined plane. The position measurement system for position information in at least three degrees of freedom directions measures the position information of the carrier, while using a mark detection system to respectively detect the first mark image and the second mark image of the plurality of arrays on the substrate, and according to the detection results of each of the first mark image and the second mark image of the plurality of arrays and the measurement information of the position measurement system when each mark image is detected, the movement of the absolute position coordinates of each of the first mark image and the second mark image of the plurality of arrays on the substrate in the predetermined plane is obtained; and according to the absolute position coordinates of the first mark image and the second mark image grouped with each other, the movement of the overlapping error is obtained. Simple diagram description

[0016] [Fig. 1] is a perspective view schematically showing the structure of the measuring device of the first embodiment. [Figure 2] (A) is a front view of the measuring device of Figure 1 with a portion omitted (seen from the -Y direction), and Figure 2 (B) is a cross-sectional view of the measuring device with a portion omitted, with the XZ plane passing through the optical axis AX1 of the mark detection system as a cross-section. [Figure 3] is a partially omitted cross-sectional view of the measuring device with the YZ plane passing through the optical axis AX1 of the mark detection system as a cross-section. [Fig. 4] (A) is a three-dimensional view showing the read head portion of the first position measurement system, and Fig. 4 (B) is a top view (seen from the +Z direction) of the read head portion of the first position measurement system. [Fig. 5] is a diagram for explaining the structure of the second position measurement system. [Fig. 6] is a block diagram showing the input-output relationship of a control device constructed with the control system of the measuring device of the first embodiment as the center. [Fig. 7] is a flow chart of a processing algorithm of a control device corresponding to processing a batch of wafers. [Figure 8] is a diagram schematically showing the overall structure of the lithography system of the second embodiment. [Figure 9] is a diagram schematically showing the structure of the exposure device shown in Figure 8. [Figure 10] is a block diagram showing the input-output relationship of the exposure control device of the exposure device. [Figure 11] is a diagram schematically showing the processing flow when the management method of the wafer grid caused by the exposure device using the measurement device 100 is applied to the lithography system 1000. FIG. 12 is a diagram schematically showing a processing flow when the overlay measurement method using the measurement device 100 is applied to the lithography system 1000. [Figure 13] is a diagram schematically showing the overall structure of a lithography system of a modified example. Implementation

[0017] <<First embodiment>> Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 is a perspective view schematically showing the structure of a measuring device 100 of the first embodiment. The measuring device 100 shown in FIG. 1 is actually composed of a chamber and components contained in 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 set as the Z-axis direction, and in a plane orthogonal to this, the direction in which the movable stage described later moves with a long stroke is set as the Y-axis direction, the direction orthogonal to the Z-axis and the Y-axis is set as the X-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are set as the θx, θy, and θz directions, respectively, for description. Here, the mark detection system MDS has an L-shaped appearance when viewed from the side (e.g., viewed from the +X direction), and a cylindrical lens barrel 41 is provided at its lower end (front end), and an optical system (refractive optical system) composed of a plurality of lens elements having an optical axis AX1 in the Z-axis direction is accommodated inside the lens barrel 41. In this specification, for the sake of convenience, 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.

[0018] FIG2(A) shows a front view (viewed from the -Y direction) of the measuring device 100 of FIG1 in a partially omitted manner, and FIG2(B) shows a cross-sectional view of the measuring device 100 with the XZ plane passing through the optical axis AX1 as a cross-section in a partially omitted manner. FIG3 also shows a cross-sectional view of the measuring device 100 with the YZ plane passing through the optical axis AX1 as a cross-section in a partially omitted manner.

[0019] The measuring device 100, as shown in FIG. 1 , comprises: a platform 12 having an upper surface substantially parallel to an XY plane orthogonal to an optical axis AX1, a wafer slider (hereinafter referred to as a slider) 10 disposed on the platform 12 and capable of holding a wafer W movable relative to the platform 12 in the X-axis and Y-axis directions with a predetermined stroke and capable of slight movement (slight displacement) in the Z-axis, θx, θy and θz directions, a driving system 20 (not shown in FIG. 1 , refer to FIG. 6 ) for driving the slider 10, and a first position measuring system 30 (not shown in FIG. 1 , refer to FIG. 6 ) for measuring position information of the slider 10 relative to the platform 12 in each direction of the X-axis, Y-axis, Z-axis, θx, θy and θz (hereinafter referred to as the six-degree-of-freedom directions). 3 and 6 ), a measuring unit 40 having a mark detection system MDS for detecting marks on a wafer W mounted (held) on the slide 10, a second position measurement system 50 (not shown in FIG. 1 , refer to FIG. 6 ) for measuring relative position information between the mark detection system MDS (measurement unit 40) and the platform 12, and a control device 60 (not shown in FIG. 1 , refer to FIG. 6 ) for obtaining measurement information of the first position measurement system 30 and measurement information of the second position measurement system 50 while controlling the driving of the slide 10 by the driving system 20 and obtaining position information of a plurality of marks on the wafer W held on the slide 10 using the mark detection system MDS.

[0020] The platform 12 is composed of a rectangular (or square) cuboid member in a top view, and its top surface is processed to be extremely flat, forming a guide surface when the slider 10 moves. As the material of the platform 12, a material with a low thermal expansion coefficient, also known as a zero expansion material, such as invar type alloy, extremely low expansion cast steel, or extremely low expansion glass ceramics is used.

[0021] The platform 12 has three spaces 12a with a cutout shape and an open bottom, one at the center of the surface on the -Y side in the X-axis direction and one at each of the two ends of the surface on the +Y side in the X-axis direction. FIG. 1 shows the space 12a formed on the surface on the -Y side among the three spaces 12a. A vibration isolating device 14 is arranged inside each space 12a. The platform 12 is supported at three points by three vibration isolating devices 14 on the upper surface of a rectangular base 16 in a plan view provided on the ground F and parallel to the XY plane so that the upper surface thereof is substantially parallel to the XY plane. The number of vibration isolating devices 14 is not limited to three.

[0022] As shown in FIG. 3 , the slider 10 has four air static pressure bearings (air bearings) 18 installed at the four corners of the bottom surface, one each, in a state where the bearing surfaces of the four air bearings are substantially flush with the bottom surface of the slider 10. The slider 10 is suspended and supported on the top surface of the platform 12 through a predetermined gap (clearance, gap), for example, a gap of several μm, by the static pressure (internal gap pressure) between the bearing surfaces of the pressurized air ejected from the four air bearings 18 toward the platform 12 and the top surface (guide surface) of the platform 12. In this embodiment, the material of the slider 10 is zero expansion glass (for example, Zerodur (trade name) of Schott Corporation, etc.), which is a kind of zero expansion material.

[0023] A concave portion 10a of a predetermined depth in a circular shape with an inner diameter slightly larger than the diameter of the wafer W when viewed from above is formed on the upper portion of the slider 10, and a wafer holder WH having a diameter substantially the same as the diameter of the wafer W is arranged inside the concave portion 10a. Although a vacuum chuck, an electrostatic chuck, or a mechanical chuck can be used as the wafer holder WH, for example, a vacuum chuck of a pin chuck type is used. The wafer W is held by the wafer holder WH by suction in a state where its upper surface is substantially flush with the upper surface of the slider 10. A plurality of suction ports are formed on the wafer holder WH, and these plurality of suction ports are connected to a vacuum pump 11 (see FIG. 6 ) through a vacuum piping system (not shown). The on / off of the vacuum pump 11 is controlled by a control device 60. In addition, either or both of the slider 10 and the wafer holder WH may be referred to as a "first substrate holding member".

[0024] In addition, the slider 10 is provided with a vertical moving member (not shown) that moves up and down through, for example, three circular openings formed in the wafer holder WH, and cooperates with the wafer transport system 70 (not shown in FIG. 1 , refer to FIG. 6 ) to load the wafer onto the wafer holder WH and unload the wafer from the wafer holder WH. The driving device 13 that drives the vertical moving member is controlled by the control device 60 (refer to FIG. 6 ).

[0025] In this embodiment, as the wafer holder WH, for example, a wafer of a size capable of adsorbing a 12-inch wafer with a diameter of 300 mm is used. In addition, when 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, it is not necessary to provide a vertical moving member on the slider 10, and it is not necessary to form a circular opening for the vertical moving member on the wafer holder WH.

[0026] As shown in FIG. 2(B) and FIG. 3, a two-dimensional grating (hereinafter referred to as grating) RG1 is horizontally arranged (parallel to the surface of the wafer W) in an area under the slider 10 that is one circle larger than the wafer W. The grating RG1 includes a reflection-type diffraction grating (X diffraction grating) with the X-axis direction as a periodic direction and a reflection-type diffraction grating (Y diffraction grating) with the Y-axis direction as a periodic direction. The pitch of the grid lines of the X diffraction grating and the Y diffraction grating is set to 1 μm, for example.

[0027] The vibration isolation device 14 is an active vibration isolation system (so-called AVIS (Active Vibration Isolation System)), which is equipped with an accelerometer, a displacement sensor (such as an electrostatic capacitance sensor, etc.), an actuator (such as a voice coil motor, etc.), and an air shock absorber (air mount) having the function of an air damper. The vibration isolation device 14 can attenuate higher frequency vibrations with an air shock absorber (air damper) and eliminate vibrations (vibration control) with an actuator. Therefore, the vibration isolation device 14 can avoid the transmission of vibrations between the platform 12 and the base 16. In addition, a hydraulic damper can be used instead of an air shock absorber (air damper).

[0028] Here, the reason why an actuator is provided in addition to the air shock absorber is that the internal pressure of the gas in the air chamber of the air shock absorber is high, and the control response can only ensure the 20Hz level. Therefore, when a high response control is required, the output control actuator of the accelerometer, etc. (not shown) must be responded to. However, micro vibrations such as ground vibrations are eliminated by the air shock absorber.

[0029] The upper end surface of the vibration isolation device 14 is connected to the platform 12. Gas (e.g., compressed air) can be supplied to the air shock absorber through a gas supply port (not shown), and the air shock absorber can be extended and retracted 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 using the air shock absorbers respectively provided by the three vibration isolation devices 14 to individually move up and down the three positions of the platform 12 from below, the positions of the platform 12 and the slider 10 suspended and supported thereon in the Z-axis direction, the θx direction, and the θy direction can be arbitrarily adjusted. In addition, the actuator of the vibration isolation device 14 can drive the platform 12 not only in the Z-axis direction, but also in the X-axis direction and the Y-axis direction. Moreover, the driving amount in the X-axis direction and the Y-axis direction is smaller than the driving amount in the Z-axis direction. The three vibration isolation devices 14 are connected to the control device 60 (refer to FIG. 6 ). Furthermore, each of the three vibration isolation devices 14 may also be provided with an actuator capable of moving the platform 12 in not only the X-axis direction, the Y-axis direction, and the Z-axis direction, but also in, for example, the six-degree-of-freedom directions. The control device 60 controls the actuators of the three vibration isolation devices 14 in real time based on the relative position information between the mark detection system MDS (measurement unit 40) and the platform 12 measured by the second position measurement system 50, so that the six-degree-of-freedom direction position of the platform 12 to which the read head 32 of the first position measurement system 30 described later is fixed is maintained at a desired positional relationship relative to the mark detection system MDS. Furthermore, each of the three vibration isolation devices 14 may also be feedforward controlled. For example, the control device 60 may feedforward control each of the three vibration isolation devices 14 based on the measurement information of the first position measurement system 30. The control of the vibration isolation device 14 by the control device 60 will be described later.

[0030] As shown in FIG. 6 , the driving system 20 includes a first driving device 20A for driving the slide 10 in the X-axis direction, and a second driving device 20B for driving the slide 10 and the first driving device 20A together in the Y-axis direction.

[0031] As can be seen from FIG. 1 and FIG. 3 , a pair of movable members 22a composed of magnet units (or coil units) and in an inverted L shape in side view are fixed at a predetermined interval in the X-axis direction on the -Y side of the slider 10. As shown in FIG. 3 , a pair of movable members 22b composed of magnet units (or coil units) are fixed at a predetermined interval in the X-axis direction on the +Y side of the slider 10 (however, the movable members 22b on the +X side are not shown). The pair of movable members 22a and the pair of movable members 22b are arranged symmetrically on the left and right and have the same structure as each other.

[0032] As shown in FIGS. 1 to 3 , the movable members 22a and 22b are supported in a non-contact manner on the upper surfaces of a pair of plate members 24a and 24b that are substantially parallel to the XY plane and are arranged at a predetermined distance in the Y-axis direction and extend in the X-axis direction, respectively, which constitute a part of the movable stage 24 that is a rectangular frame in top view. That is, air bearings (not shown) are provided on the lower surfaces of the movable members 22a and 22b (the surfaces facing the plate members 24a and 24b, respectively), and the movable members 22a and 22b are supported in a non-contact manner from below by the movable stage 24 by the suspension force (static pressure of pressurized air) generated by these air bearings on the plate members 24a and 24b. In addition, the weight of the slider 10 to which each pair of movable members 22a and 22b is fixed is supported by the suspension force generated by the four air bearings 18 on the platform 12, as described above.

[0033] As shown in FIGS. 1 to 3 , stators 26a and 26b composed of coil units (or magnet units) are arranged on each of the pair of plate members 24a and 24b in the area other than the two end portions in the X-axis direction.

[0034] By electromagnetic interaction between the pair of movable members 22a and the stator 26a, a driving force (electromagnetic force) for driving the pair of movable members 22a in the X-axis direction and a driving force (electromagnetic force) for driving the pair of movable members 22a in the Y-axis direction are generated, and by electromagnetic interaction between the pair of movable members 22b and the stator 26b, a driving force (electromagnetic force) for driving the pair of movable members 22b in the X-axis direction and a driving force (electromagnetic force) for driving the pair of movable members 22b in the Y-axis direction are generated. That is, the pair of movable members 22a and the stator 26a constitute an XY linear motor 28A that generates driving forces in the X-axis direction and the Y-axis direction, and the pair of movable members 22b and the stator 26b constitute an XY linear motor 28B that generates driving forces in the X-axis direction and the Y-axis direction. The XY linear motor 28A and the XY linear motor 28B constitute a first driving device 20A (see FIG. 6 ) that drives the slide 10 in the X-axis direction at a predetermined stroke and slightly drives it in the Y-axis direction. The first drive device 20A can drive the slide 10 in the θz direction by making the magnitude of the driving force in the X-axis direction generated by the XY linear motor 28A and the XY linear motor 28B different. The first drive device 20A is controlled by the control device 60 (refer to FIG. 6 ). In this embodiment, the first drive device 20A, together with the second drive device described later, constitutes a coarse and fine motion drive system for driving the slide 10 in the Y-axis direction. It can be seen that the first drive device 20A can generate not only the driving force in the X-axis direction but also the driving force in the Y-axis direction, but the first drive device 20A does not necessarily have to generate the driving force in the Y-axis direction.

[0035] The movable stage 24 has a pair of plate members 24a, 24b, and a pair of connecting members 24c, 24d arranged at a predetermined distance in the X-axis direction and extending in the Y-axis direction. Steps are formed at both ends of the connecting members 24c, 24d in the Y-axis direction. The connecting members 24c, 24d are integrated with the plate member 24a in a state where one end and the other end in the long side direction of the plate member 24a are placed on the step on the -Y side of each of the connecting members 24c, 24d. In addition, the connecting members 24c, 24d are integrated with the plate member 24b in a state where one end and the other end in the long side direction of the plate member 24b are placed on the step on the +Y side of each of the connecting members 24c, 24d (refer to FIG. 2(B)). That is, in this manner, a pair of plate members 24a, 24b are connected by a pair of connecting members 24c, 24d to form a movable stage 24 in a rectangular frame shape.

[0036] As shown in FIG. 1 and FIG. 2(A), a pair of linear guides 27a and 27b extending in the Y-axis direction are fixed near both ends in the X-axis direction of the upper surface of the base 16. A stator 25a (see FIG. 2(B)) of a Y-axis linear motor 29A composed of a coil unit (or a magnet unit) extending substantially the entire length in the Y-axis direction near the upper surface and the -X side surface is accommodated inside the linear guide 27a located on the +X side. A movable member 23a composed of a magnet unit (or a coil unit) having an L-shaped cross section and constituting the Y-axis linear motor 29A together with the stator 25a is arranged facing the upper surface and the -X side surface of the linear guide 27a. Air bearings that eject pressurized air to the facing surfaces are fixed to the lower surface and the +X side surface of the movable member 23a that are not facing the upper surface and the -X side surface of the linear guide 27a. Among them, the air bearing fixed to the +X side surface of the movable member 23a is a vacuum preload type air bearing. This vacuum preload type air bearing maintains the X-axis direction gap (gap) between the movable member 23a and the linear guide 27a at a fixed value by balancing the static pressure of the pressurized air between the bearing surface and the -X side surface of the linear guide 27a and the vacuum preload.

[0037] On the upper surface of the movable member 23a, a plurality of X guides 19, for example, composed of two rectangular parallelepiped members, are fixed at predetermined intervals in the Y-axis direction. Each of the two X guides 19 is provided with a sliding member 21 having an inverted U-shaped cross section that forms a single-axis guide device together with the X guide 19, and is engaged in a non-contact manner. Air bearings are provided on the three surfaces of the sliding member 21 that face the X guide 19.

[0038] As shown in FIG. 1 , the two sliding members 21 are respectively fixed to the lower surface (the surface on the −Z side) of the connecting member 24c.

[0039] The other linear guide 27b located on the -X side has a stator 25b of a Y-axis linear motor 29B composed of a coil unit (or a magnet unit) stored therein, and is symmetrical with respect to the linear guide 27a (see FIG. 2(B)). A movable member 23b is arranged facing the upper surface and the +X side surface of the linear guide 27b, which is symmetrical with respect to the upper surface and the +X side surface and is composed of a magnet unit (or a coil unit) having the same L-shaped cross section as the movable member 23a, and which together with the stator 25b constitutes the Y-axis linear motor 29B. Air bearings are fixed to the lower surface and the -X side surface of the movable member 23b, respectively, facing the upper surface and the +X side surface of the linear guide 27b. In particular, a vacuum preload type air bearing is used as the air bearing fixed to the -X side surface of the movable member 23b. By means of this vacuum preload type air bearing, the gap (clearance, gap) in the X-axis direction between the mover 23b and the linear guide 27b is maintained at a fixed value.

[0040] Between the upper surface of the movable member 23b and the bottom surface of the connecting member 24d, similarly to the above, two single-axis guide devices consisting of an X guide 19 and a sliding member 21 engaged with the X guide 19 in a non-contact manner are provided.

[0041] The movable stage 24 is supported from below by the movable members 23a and 23b through two (four in total) single-axis guide devices on the +X side and the -X side, and can move on the movable members 23a and 23b in the X-axis direction. Therefore, when the slider 10 is driven in the X-axis direction by the first driving device 20A, the reaction force of the driving force acts on the movable stage 24 provided with the stators 26a and 26b, and the movable stage 24 moves in the opposite direction to the slider 10 according to the law of conservation of momentum. That is, the occurrence of vibration caused by the reaction force of the driving force in the X-axis direction of the slider 10 can be prevented (or effectively suppressed) by the movement of the movable stage 24. That is, the movable stage 24 functions as a counterweight when the slider 10 moves in the X-axis. However, it is not necessary to make the movable stage 24 function as a counterweight. In addition, since the slider 10 only moves slightly in the Y-axis direction relative to the movable carrier 24, although it is not specially provided, a balancing mass can be provided 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 carrier 24.

[0042] The Y-axis linear motor 29A generates a driving force (electromagnetic force) to drive the movable member 23a in the Y-axis direction through the electromagnetic interaction between the movable member 23a and the stator 25a, while the Y-axis linear motor 29B generates a driving force (electromagnetic force) to drive the movable member 23b in the Y-axis direction through the electromagnetic interaction between the movable member 23b and the stator 25b.

[0043] The driving force in the Y-axis direction generated by the Y-axis linear motors 29A and 29B acts on the movable stage 24 through the two single-axis guide devices on the +X side and the -X side. As a result, the slider 10 is driven in the Y-axis direction integral with the movable stage 24. That is, in this embodiment, the second driving device 20B (refer to FIG. 6 ) that drives the slider 10 in the Y-axis direction is composed of the movable stage 24, the four single-axis guide devices, and the pair of Y-axis linear motors 29A and 29B.

[0044] In this embodiment, the pair of Y-axis linear motors 29A and 29B are physically separated from the platform 12, and are also separated in vibration by the three vibration isolating devices 14. In addition, the linear guides 27a and 27b provided on the stators 25a and 25b of the pair of Y-axis linear motors 29A and 29B, respectively, can be made movable in the Y-axis direction relative to the base 16, so as to function as a counterweight when the slider 10 is driven in the Y-axis direction.

[0045] The measuring unit 40, as shown in FIG1 , comprises a unit body 42 having a notch-shaped space 42a with a bottom opening formed on the surface on the -Y side, the aforementioned mark detection system MDS connected to the unit body 42 with the base end portion inserted into the space 42a, and a connecting mechanism 43 connecting the lens barrel portion 41 at the front end of the mark detection system MDS to the unit body 42.

[0046] The connecting mechanism 43 includes a support plate 44 that supports the lens barrel portion 41 on the back side (+Y side) through a mounting member not shown in the figure, and a pair of support arms 45a, 45b that support the support plate 44 at each end and fix the other end to the bottom surface of the unit body 42.

[0047] In this embodiment, since the wafer held on the slider 10 is coated with a sensitive agent (resist), a detection beam of a wavelength that does not photosensitively affect the resist is used as the mark detection system MDS. As the mark detection system MDS, for example, a broadband detection beam that does not photosensitively affect the resist coated on the wafer is used to irradiate the target mark, and a photographic element (CCD, etc.) is used to photograph the image of the target mark formed on the light receiving surface by the reflected light from the target mark and the image of the index (index pattern provided on the internal index plate) not shown, and the FIA (Field Image Alignment) system of the image processing method of outputting these photographic signals. The photographic signal from the mark detection system MDS is supplied to the control device 60 (refer to FIG. 6) through the signal processing device 49 (not shown in FIG. 1, refer to FIG. 6). The mark detection system MDS has an alignment auto focus function for adjusting the focal position of the optical system.

[0048] As shown in FIG. 1 , a head mounting member 51 having a roughly equilateral triangle shape is disposed between the lens barrel 41 and the support plate 44. An opening portion penetrating in the Y-axis direction of FIG. 1 is formed in the head mounting member 51, and the lens barrel 41 is mounted (fixed) on the support plate 44 through a mounting member (not shown) inserted into the opening portion. In addition, the back side of the head mounting member 51 is also fixed to the support plate 44. In this way, the lens barrel 41 (mark detection system MDS), the head mounting member 51, and the support plate 44 are integrated with the unit body 42 through a pair of support arms 45a and 45b.

[0049] Inside the unit body 42, there is disposed the aforementioned signal processing device 49, etc., which processes the photographic signal outputted as the detection signal from the mark detection system MDS to calculate the position information of the target mark relative to the detection center and outputs it to the control device 60. The unit body 42 is supported from three points from below by a plurality of, for example, three, vibration isolation devices 48 on a support frame 46 which is provided on the base 16 and is in a door-shaped shape as viewed from the -Y side. Each vibration isolation device 48 is an active vibration isolation system (so-called AVIS (Active Vibration Isolation System)) and is equipped with an accelerometer, a displacement sensor (such as an electrostatic capacitance sensor, etc.), an actuator (such as a voice coil motor, etc.), and a mechanical damper such as an air damper or a hydraulic damper. The vibration isolation device 48 can attenuate higher frequency vibrations with a mechanical damper and can perform vibration isolation (vibration control) with an actuator. Therefore, each vibration isolation device 48 can avoid the transmission of higher frequency vibrations between the support frame 46 and the unit body 42.

[0050] Furthermore, the mark detection system MDS is not limited to the FIA system. For example, instead of the FIA system, a diffraction light interference type alignment detection system may be used, which emits coherent detection light to the target mark, causes two diffraction lights (for example, diffraction lights of the same order or diffraction lights diffracted in the same direction) generated from the target mark to interfere and detect and then output a detection signal. Alternatively, the diffraction light interference type alignment system may be used together with the FIA system to simultaneously detect two target marks. Furthermore, as the mark detection system MDS, a beam scanning type alignment system may be used, which scans the target mark in a predetermined direction with the measurement light while the slider 10 is moved in a predetermined direction. Furthermore, in the present embodiment, although the mark detection system MDS has an alignment autofocus function, it may be replaced or added with a focus position detection system provided in the measurement unit 40, for example, a multi-point focus position detection system of an oblique incidence method having the same structure as disclosed in the specification of U.S. Patent No. 5,448,332.

[0051] The first position measuring system 30, as shown in FIG. 2(B) and FIG. 3, includes a head section 32 disposed in a recess formed on the upper surface of the platform 12 and fixed to the platform 12. The upper surface of the head section 32 faces the lower surface (the surface on which the grating RG1 is formed) of the slider 10. A predetermined gap (clearance, gap), for example, a gap of several mm, is formed between the upper surface of the head section 32 and the lower surface of the slider 10.

[0052] As shown in FIG. 6 , the first position measurement system 30 includes an encoder system 33 and a laser interferometer system 35. The encoder system 33 provides a plurality of light beams from the head 32 to the measuring portion (the formation surface of the grating RG1) under the slider 10, and can receive a plurality of return light beams (for example, a plurality of diffracted light beams from the grating RG1) from the measuring portion under the slider 10 to obtain the 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 head having the same structure as the encoder head (hereinafter referred to as a head as appropriate) disclosed in, for example, U.S. Patent No. 7,238,931 and U.S. Patent Application Publication No. 2007 / 288,121. In addition, the reader includes a light source and a light receiving system (including a light detector), and an optical system. In this embodiment, as long as at least the optical system is arranged inside the housing of the reader head 32 opposite to the grating RG1, at least one of the light source and the light receiving system can be arranged outside the housing of the reader head 32.

[0053] FIG. 4(A) is a perspective view of the head section 32, and FIG. 4(B) is a top view of the head section 32 viewed from the +Z direction. The encoder system 33 measures the position of the slider 10 in the X-axis direction with one X head 37x, and measures the position in the Y-axis direction with a pair of Y heads 37ya, 37yb (see FIG. 4(B)). That is, the X head 37x that measures the position of the slider 10 in the X-axis direction using the X diffraction grating of the grating RG1 constitutes the X linear encoder 33x, and the pair of Y heads 37ya, 37yb that measure the position of the slider 10 in the Y-axis direction using the Y diffraction grating of the grating RG1 constitutes a pair of Y linear encoders 33ya, 33yb.

[0054] As shown in FIG. 4(A) and FIG. 4(B), the X head 37x irradiates the measuring beams LBx1 and LBx2 (shown by solid lines in FIG. 4(A)) to the same irradiation point on the grating RG1 from two points (refer to the white circle in FIG. 4(B)) which are equidistant on the straight line LX parallel to the X axis passing through the center of the head 32 and the straight line CL parallel to the Y axis passing through the center of the head 32. The irradiation point of the measuring beams LBx1 and LBx2, i.e., the detection point of the X head 37x (refer to the symbol DP in FIG. 4(B)), has the same position in the X-axis direction and the Y-axis direction as the detection center of the mark detection system MDS.

[0055] Here, the measuring beams LBx1 and LBx2 are beams from a light source that are polarized and separated by a polarizing beam splitter (not shown). When the measuring beams LBx1 and LBx2 are irradiated on the grating RG1, these measuring beams LBx1 and LBx2 are diffracted a predetermined number of times by the X-diffraction grating, for example, the first diffracted beam (the first diffracted beam) passes through a lens and a quarter-wave plate (not shown) respectively and are reflected by a reflector. The polarization direction is rotated 90 degrees by passing through the second quarter-wave plate, and they are incident on the polarizing beam splitter again through the original optical path and synthesized into a coaxial beam. Then, the interference light of the first diffracted beams of the measuring beams LBx1 and LBx2 is received by a photodetector (not shown), and the position of the slider 10 in the X-axis direction is measured accordingly.

[0056] As shown in FIG4(B), a pair of Y heads 37ya and 37yb are arranged on the +X side and -X side of the straight line CL, respectively. As shown in FIG4(A) and FIG4(B), the Y head 37ya irradiates the common irradiation point on the grating RG1 from two points on the straight line LYa that are equidistant from the straight line LX (see the white circles in FIG4(B)) with the measuring beams LBya1 and LBya2 shown by the dotted lines in FIG4(A). The irradiation points of the measuring beams LBya1 and LBya2, i.e., the detection points of the Y head 37ya, are indicated by the symbol DPya in FIG4(B).

[0057] The Y head 37yb irradiates the measuring beams LByb 1 and LByb 2 to the common irradiation point DPyb on the grating RG1 from two points symmetrical to the irradiation points of the measuring beams LBya 1 and LBya 2 of the Y head 37ya (see the white circle in FIG4(B)). As shown in FIG4(B), the detection points DPya and DPyb of the Y heads 37ya and 37yb are arranged on the straight line LX parallel to the X axis.

[0058] The measuring beams LBya 1 and LBya 2 are also the same beams polarized and separated by a polarizing beam splitter. The interference lights of the measuring beams LBya 1 and LBya 2 are detected by a photodetector (not shown) for a predetermined number of diffracted beams (for example, the first diffracted beams) through the Y diffraction grating in the same manner as described above, so as to measure the position of the slider 10 in the Y-axis direction. For the measuring beams LByb 1 and LByb 2, the interference lights of the first diffracted beams (the second diffracted beams) are detected by a photodetector (not shown) for a photodetector (not shown) in the same manner as the measuring beams LBya 1 and LBya 2, so as to measure the position of the slider 10 in the Y-axis direction.

[0059] 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 of the two Y reading heads 37ya and 37yb. Therefore, in this embodiment, the position of the slider 10 in the Y-axis direction is measured by taking the midpoint DP of the detection points DPya and DPyb as the actual measurement point. The midpoint DP coincides with the irradiation point of the measurement beams LBx1 and LBX2 on the grating RG1.

[0060] That is, in this embodiment, the measurement of the position information of the slider 10 in the X-axis direction and the Y-axis direction has a common detection point, and this detection point is controlled by the control device 60 in real time based on the relative position information of the mark detection system MDS (measurement unit 40) and the stage 12 measured by the second position measurement system 50, so that the actuators of the three vibration isolation devices 14 are consistent with the position of the detection center of the mark detection system MDS in the XY plane. Therefore, in this embodiment, 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 (the back side of the slider 10) when measuring the alignment mark on the wafer W placed on the slider 10 by using the encoder system 33. 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 the pair of Y readers 37ya and 37yb.

[0061] The laser interferometer system 35 can emit a length measuring beam into the measuring portion (the surface where the grating RG1 is formed) on the bottom surface of the slider 10, and receive its return beam (for example, reflected light from the surface where the grating RG1 is formed) to obtain the position information of the slider 10. As shown in FIG4(A), the laser interferometer system 35 emits four length measuring beams LBz 1, LBz 2, LBz 3, and LBz 4 into the bottom surface of the slider 10 (the surface where the grating RG1 is formed). The laser interferometer system 35 includes laser interferometers 35a to 35d (see FIG6) that respectively irradiate these four length measuring beams LBz 1, LBz 2, LBz 3, and LBz 4. In this embodiment, the laser interferometers 35a to 35d constitute four Z heads.

[0062] In the laser interferometer system 35, as shown in FIG. 4(A) and FIG. 4(B), four length measuring beams LBz 1, LBz 2, LBz 3, and LBz 4 are emitted in parallel with the Z axis from four points corresponding to the vertices of a square having two sides parallel to the X axis and two sides parallel to the Y axis with the detection point DP as the center. In this case, the emission points (irradiation points) of the length measuring beams LBz 1 and LBz 4 are on the straight line LYa and are equidistant from the straight line LX, and the emission points (irradiation points) of the remaining length measuring beams LBz 2 and LBz 3 are on the straight line LYb and are equidistant from the straight line LX. In this embodiment, the surface on which the grating RG1 is formed also serves as a reflection surface for each length measuring beam from the laser interferometer system 35. The control device 60 uses the laser interferometer system 35 to measure the information of the position of the slider 10 in the Z axis direction and the rotation amount in the θx direction and the θy direction. Furthermore, it can be seen from the above description that although the slider 10 is not actively driven by the aforementioned driving system 20 relative to the platform 12 in the directions of the Z axis, θx, and θy, it is suspended and supported on the platform 12 by four air bearings 18 disposed at the four corners of the bottom surface. Therefore, in fact, the position of the slider 10 on the platform 12 in the directions of the Z axis, θx, and θy will change. That is, the slider 10 is actually movable relative to the platform 12 in the directions of the Z axis, θx, and θy. In particular, the displacement of the slider 10 in the directions of θx and θy will generate measurement errors (Abbe errors) of the encoder system 33. Considering this point, the first position measurement system 30 (laser interferometer system 35) is used to measure the position information of the slider 10 in the directions of the Z axis, θx, and θy.

[0063] Furthermore, in order to measure the Z-axis position of the slider 10 and the rotation information in the θx direction and the θy direction, it is sufficient to allow the light beam to enter three different points on the surface on which the grating RG1 is formed, so only three Z readers, such as laser interferometers, are required. In addition, a protective glass for protecting the grating RG1 may be provided under the slider 10, and a wavelength selective filter may be provided to prevent the penetration of each length measurement beam from the laser interferometer system 35 while allowing each measurement beam from the encoder system 33 to pass through the surface of the protective glass.

[0064] As can be seen from the above description, the control device 60 can measure the position of the slider 10 in the six degrees of freedom direction by using the encoder system 33 and the laser interferometer system 35 of the first position measurement system 30. In this case, in the encoder system 33, the optical path length of the measuring light beam in the air is extremely short and substantially equal, so the influence of air fluctuations can be almost ignored. Therefore, the encoder system 33 can measure the position information of the slider 10 in the XY plane (including the θz direction) with high accuracy. In addition, the detection point of the encoder system 33 on the actual grating RG1 in the X-axis direction and the Y-axis direction, and the detection point of the laser interferometer system 35 on the bottom surface of the slider 10 in the Z-axis direction are respectively consistent with the detection center of the mark detection system MDS in the XY plane. Therefore, the occurrence of the so-called Abbe error caused by the offset between the detection point and the detection center of the mark detection system MDS in the XY plane will be suppressed to a substantially negligible level. Therefore, the control device 60, by using the first position measurement system 30, can measure the position of the slide 10 in the X-axis direction, Y-axis direction and Z-axis direction with high precision without the Abbe error caused by the deviation of the detection point and the detection center of the mark detection system MDS in the XY plane.

[0065] However, as far as the Z-axis direction of the mark detection system MDS parallel to the optical axis AX1 is concerned, the position on the surface of the wafer W is not the position information in the XY plane of the slider 10 measured by the encoder system 33, that is, the Z position of the configuration surface of the grating RG1 is not consistent with the Z position of the surface of the wafer W. Therefore, when the grating RG1 (that is, 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) reflecting the tilt of the grating RG1 relative to the XY plane due to the difference ΔZ between the Z position of the configuration surface of the grating RG1 and the surface of the wafer W (that is, the positional offset in the Z-axis direction between the detection point using the encoder system 33 and the detection center (detection point) using the mark detection system MDS). However, this positioning error (position control error) can be obtained by simple calculation using the difference ΔZ and the pitching amount θx and the rolling amount θy, and this is used as an offset. The positioning of the slider 10 is performed based on the position information corrected by correcting the measured value of the encoder system 33 (each encoder) by this offset, which will not be affected by the above-mentioned Abbe error. Alternatively, instead of correcting the measured value of the encoder system 33 (each encoder), one or more information for moving the slider, such as the target position of the slider 10 to be positioned, can be corrected based on the above-mentioned offset.

[0066] Furthermore, when the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the read head 32 may be moved to avoid the generation of positioning errors caused by the tilt. That is, when the first position measurement system 30 (e.g., the interferometer system 35) measures that the grating RG1 (i.e., the slider 10) is tilted relative to the XY plane, the stage 12 holding the read head 32 may be moved based on the position information obtained using the first position measurement system 30. The stage 12 may be moved using the vibration isolation device 14 as described above.

[0067] Furthermore, when the grating RG1 (ie, the slider 10) is tilted relative to the XY plane, the positioning error caused by the tilt can be corrected using the position information of the mark obtained by the mark detection system MDS.

[0068] The second position measurement system 50, as shown in FIG. 1 , FIG. 2 (A) and FIG. 2 (B), comprises a pair of read heads 52A, 52B respectively disposed below one end and the other end in the long side direction of the read head mounting member 51, and scale members 54A, 54B disposed opposite to the read heads 52A, 52B. The top surfaces of the scale members 54A, 54B are set to be at the same height as the surface of the wafer W held on the wafer holder WH. Reflective two-dimensional gratings RG2a, RG2b are formed on the top surfaces of the scale members 54A, 54B. The two-dimensional gratings (hereinafter referred to as gratings) RG2a, RG2b both include a reflective diffraction grating (X diffraction grating) with the X-axis direction as a periodic direction, and a reflective diffraction grating (Y diffraction grating) with the Y-axis direction as a periodic direction. The pitch of the grating lines of the X diffraction grating and the Y diffraction grating is set to, for example, 1 μm.

[0069] The scale members 54A and 54B are made of a material with a low thermal expansion coefficient, such as the aforementioned zero expansion material, and are fixed to the platform 12 through the support member 56, as shown in FIG. 2(A) and FIG. 2(B). In this embodiment, the sizes of the scale members 54A and 54B and the support member 56 are determined in such a way that the gratings RG2a and RG2b face the read heads 52A and 52B with a gap of several mm.

[0070] As shown in Fig. 5, a head 52A fixed to the lower side of the +X side end of the head mounting member 51 includes an XZ head 58X1 with the X-axis and Z-axis directions as the measuring directions, and a YZ head 58Y1 with the Y-axis and Z-axis directions as the measuring directions, which are housed in the same housing. The XZ head 58X1 (more precisely, the irradiation point of the measuring beam emitted by the XZ head 58X1 on the grating RG2a) and the YZ head 58Y1 (more precisely, the irradiation point of the measuring beam emitted by the YZ head 58Y1 on the two-dimensional grating RG2a) are arranged on the same straight line parallel to the Y axis.

[0071] The other head 52B is symmetrically arranged with the head 52A with respect to the straight line (hereinafter referred to as the reference axis) LV parallel to the optical axis AX1 passing through the mark detection system MDS and the Y axis, and its structure is the same as that of the head 52A. That is, the head 52B has the XZ head 58X2 and the YZ head 58Y2 arranged symmetrically with the XZ head 58X1 and the YZ head 58Y1 with respect to the reference axis LV, and the irradiation points of the measuring light beams irradiated on the grating RG2b from the XZ head 58X2 and the YZ head 58Y2 are set on the same straight line parallel to the Y axis. Here, the reference axis LV coincides with the aforementioned straight line CL.

[0072] Each of the XZ heads 58X1 and 58X2, and the YZ heads 58Y1 and 58Y2 can use an encoder head having the same structure as the displacement measurement sensor head disclosed in the specification of U.S. Patent No. 7,561,280.

[0073] The read heads 52A and 52B respectively use scale members 54A and 54B to form an XZ linear encoder for measuring the X-axis position (X position) and Z-axis position (Z position) of the gratings RG2a and RG2b, and a YZ linear encoder for measuring the Y-axis position (Y position) and Z position. Here, the gratings RG2a and RG2b are formed on the scale members 54A and 54B respectively fixed to the platform 12 through the support member 56, and the read heads 52A and 52B are provided on the read head mounting member 51 integrated with the mark detection system MDS. As a result, the 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). In the following, for convenience, the XZ linear encoder, the YZ linear encoder, and the XZ heads 58X1, 58X2, and the YZ heads 58Y1, 58Y2 are denoted by the same symbols and are recorded as XZ linear encoders 58X1, 58X2, and YZ linear encoders 58Y1, 58Y2 (see FIG. 6 ).

[0074] In this embodiment, the XZ linear encoder 58X1 and the YZ linear encoder 58Y1 constitute a four-axis encoder 581 (see FIG6 ) for measuring the position information of the platform 12 relative to the mark detection system MDS in the X-axis, Y-axis, Z-axis and θx directions. Similarly, the XZ linear encoder 58X2 and the YZ linear encoder 58Y2 constitute a four-axis encoder 582 (see FIG6 ) for measuring the position information of the platform 12 relative to the mark detection system MDS in the X-axis, Y-axis, Z-axis and θx directions. In this case, based on the position information of the platform 12 relative mark detection system MDS in the Z-axis direction measured by the 4-axis encoders 58 1 and 58 2 respectively, the position information of the platform 12 relative mark detection system MDS in the θy direction is calculated (measured). Based on the position information of the platform 12 relative mark detection system MDS in the Y-axis direction measured by the 4-axis encoders 58 1 and 58 2 respectively, the position information of the platform 12 relative mark detection system MDS in the θz direction is calculated (measured).

[0075] Therefore, the 4-axis encoder 581 and the 4-axis encoder 582 constitute the second position measurement system 50 for measuring the position information of the platform 12 in the 6-DOF direction relative to the mark detection system MDS, that is, for measuring the relative position of the mark detection system MDS and the platform 12 in the 6-DOF direction. The relative position information of the mark detection system MDS and the platform 12 in the 6-DOF direction measured by the second position measurement system 50 is supplied to the control device 60 at any time. The control device 60 controls the actuators of the three vibration isolation devices 14 in real time according to the relative position information so that the detection point of the first position measurement system 30 is in a desired positional relationship with the detection center of the mark detection system MDS. Specifically, the detection point of the first position measurement system 30 and the detection center of the mark detection system MDS are made to coincide with each other in the XY plane, for example, at the nm level, and the surface of the wafer W on the slide 10 is made to coincide 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 have a desired positional relationship with respect to the detection center of the mark detection system MDS, the second position measurement system 50 may not measure the relative position information in all directions of the six degrees of freedom.

[0076] FIG6 shows a block diagram of the input-output relationship of the control device 60 which is constructed with the control system of the measuring device 100 of this embodiment as the center. The control device 60 includes a workstation (or a microcomputer) and the like, and comprehensively controls the components of the measuring device 100. As shown in FIG6, the measuring device 100 is provided with a wafer transfer system 70 which is arranged in the chamber together with the components shown in FIG1. The wafer transfer system 70 is composed of, for example, a horizontal multi-joint type robot.

[0077] Next, a series of operations when a batch of wafers is processed in the measurement device 100 of the present embodiment constructed as described above will be described based on the flowchart of FIG. 7 of the processing algorithm of the corresponding control device 60.

[0078] As a premise, the wafer W to be measured by the measuring device 100 is a 300 cm wafer. On the wafer W, a plurality of, for example, 1 (for example, 1=98) partition areas called irradiation areas (hereinafter, also referred to as irradiation areas) are formed in a matrix arrangement by exposure before the front layer. On the dicing streets (street lines) surrounding each irradiation area or the dicing streets inside each irradiation area (when one irradiation area takes a plurality of wafers), a plurality of types of marks, for example, search alignment marks (search marks) for search alignment, wafer alignment marks (wafer marks) for precision alignment, etc., are provided. These plurality of types of marks are formed together with the partition areas. In this embodiment, two-dimensional marks are used as search marks and wafer marks.

[0079] Furthermore, the measuring device 100 can set a plurality of measurement modes with different conditions for mark detection by the mark detection system MDS. For example, the plurality of measurement modes can be set to detect one wafer mark in each irradiation area of all wafers, and to detect a plurality of wafer marks in all irradiation areas for the first predetermined number of wafers in a batch, and to determine a wafer mark to be detected for each irradiation area for the remaining wafers in the batch based on the detection results of the wafer marks and detect the determined wafer marks.

[0080] Furthermore, the operator of the measuring device 100 inputs information required for alignment measurement of the wafer W in advance through 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 thickness information of the wafer W, flatness information of the wafer holder WH, and design information of the arrangement of the irradiation area and alignment marks on the wafer W. In addition, the setting information of the measurement mode is input in advance by the operator through an input device (not shown), for example.

[0081] The processing algorithm corresponding to the flowchart of FIG. 7 starts, for example, when an operator instructs the start of measurement. At this time, a batch of wafers are 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 to a substrate processing device (such as a coating, developing device, etc.) in an inline manner, it can also be started when a request for permission to start the transfer of a batch of wafers is received from the control system of the substrate processing device, and the first wafer is moved to a predetermined delivery position in response to the request. In addition, the so-called inline connection refers to the state of connecting different devices to each other in a state of being connected by the transfer path of the wafer (substrate). In this specification, the terms "connected in an inline manner" or "online" are used in this sense.

[0082] First, in step S102, the count value i of the counter showing the wafer number within the lot is initialized to 1 (i←1).

[0083] In the next step S104, the wafer W is loaded onto the slide 10. The loading of the wafer W is performed by the wafer transport system 70 and the up-and-down moving member on the slide 10 under the control of the control device 60. Specifically, the wafer W is transported from the wafer carrier (or the delivery position) to the top of the slide 10 at the loading position by the wafer transport system 70, and the up-and-down moving member is driven to rise by a predetermined amount by the driving device 13, thereby delivering the wafer W to the up-and-down moving member. Then, after the wafer transport system 70 withdraws from the top of the slide 10, the up-and-down moving member is driven to descend by the driving device 13, thereby placing the wafer W on the wafer holder WH on the slide 10. Then, the vacuum pump 11 is turned on, and the wafer W loaded on the slide 10 is vacuum-absorbed by the wafer holder WH. Furthermore, when the measuring device 100 is connected to the substrate processing device in an online manner, wafers are sequentially carried in from the wafer transport system of the substrate processing device and placed at the delivery position.

[0084] In the next step S106, the Z-axis position (Z position) of the wafer W is adjusted. Before this Z position adjustment, the control device 60 controls the internal pressure of the air shock absorbers of the three vibration isolation devices 14 (the driving force in the Z-axis direction generated by the vibration isolation device 14) according to the relative position information of the mark detection system MDS and the platform 12 in the Z-axis direction, θy direction, and θx direction measured by the second position measurement system 50. The platform 12 is set so that its top surface is parallel to the XY plane and the Z position is at a predetermined reference position. The thickness of the 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 isolation devices 14, such as the internal pressure of the air shock absorber (the amount of compressed air), according to the thickness information of the wafer W in the memory, so that the surface of the wafer W is set in a range where the focus position of the optical system can be adjusted by the autofocus function of the mark detection system MDS, and drives the platform 12 in the Z-axis direction to adjust the Z position of the surface of the wafer W. Furthermore, when the measurement unit 40 is provided with a focus position detection system, the control device 60 may also adjust the Z position of the wafer surface according to the detection result (output) of the focus position detection system. For example, the mark detection system MDS may be provided with a focus position detection system that detects the Z-axis position of the surface of the wafer W through the optical element (object optical element) at the front end. In addition, the Z position adjustment of the surface of the wafer W performed according to the detection result of the focus position detection system may be performed by moving the stage 12 using the vibration isolation device 14 and moving the slider 10 together with the stage 12. Furthermore, a drive system 20 that can drive the slider 10 not only in the direction within the XY plane but also in the Z-axis direction, the θx direction, and the θy direction may be used to move the slider 10. Furthermore, the Z position adjustment of the wafer surface may also include the tilt adjustment of the wafer surface. When the drive system 20 is used to adjust the tilt of the wafer surface, and there is a possibility that an error (an Abbe error) may occur due to the difference ΔZ between the Z position of the configuration surface of the grating RG1 and the surface of the wafer W, at least one of the above-mentioned countermeasures can be implemented.

[0085] In the next step S108, search alignment of the wafer W is performed. Specifically, for example, at least two search marks located at the periphery approximately symmetrically with respect to the center of the wafer W are detected using the mark detection system MDS. The control device 60 controls the drive of the slider 10 by the drive system 20, and while positioning each search mark within the detection area (detection field of view) of the mark detection system MDS, the measurement information of the first position measurement system 30 and the measurement information of the second position measurement system 50 are obtained, and the position information of each search mark is obtained based on the detection signal when the search mark formed on the wafer W is detected using the mark detection system MDS and the measurement information of the first position measurement system 30 (and the measurement information of the second position measurement system 50).

[0086] More specifically, the control device 60 obtains the position coordinates of the two search marks on the reference coordinate system based on the detection result of the mark detection system MDS output from the signal processing device 49 (the relative position relationship between the detection center (index center) of the mark detection system MDS obtained from the detection signal and each search mark), and the measurement value of the first position measurement system 30 and the measurement value of the second position measurement system 50 when each search mark is detected. Here, the reference coordinate system is an orthogonal coordinate system defined by the major axis of the first position measurement system 30.

[0087] After that, the residual rotation error of the wafer W is calculated from the position coordinates of the two search marks, and the slider 10 is slightly rotated so that the rotation error is substantially zero. Thus, the search alignment of the wafer W is completed. In addition, since the wafer W is actually loaded on the slider 10 in a pre-aligned state, the center position deviation of the wafer W is small enough to be ignored, and the residual rotation error is very small.

[0088] In the next step S110, it is determined whether the set measurement mode is mode A. If the determination in this step S110 is affirmative, that is, if the mode A has been set, the process proceeds to step S112.

[0089] In step S112, alignment measurement is performed on the entire wafer (1-point measurement of the entire irradiation area, in other words, measurement of the entire irradiation area EGA), that is, one wafer mark is measured for each of the 98 irradiation areas. Specifically, the control device 60 obtains the position coordinates of the wafer mark on the wafer W in the reference coordinate system, that is, the position coordinates of the irradiation area, in the same manner as the measurement of the position coordinates of each search mark in the aforementioned search alignment. However, in this case, unlike 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 for this is that, as described above, the control device 60 controls the actuators of the three vibration isolation devices 14 in real time based on the measurement information of the second position measurement system 50, so that 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, for example, at the nm level, and the surface of the wafer W on the slider 10 is consistent with the detection position of the mark detection system MDS. However, when detecting the wafer mark, since there is no compensation for 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 to be consistent with each other at the level of, for example, nm, the positional offset between the two must be considered as a misalignment to calculate the position coordinates of the irradiation area. For example, by using the detection result of the mark detection system MDS or the measurement value of the first position measurement system 30 corrected by the above-mentioned misalignment, the calculated position coordinates of the wafer mark on the wafer W on the reference coordinate system can be corrected.

[0090] Here, when measuring one point in the entire irradiation area, the control device 60 moves the slider 10 (wafer W) in at least one direction of the X-axis direction and the Y-axis direction through the driving system 20 to position 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-and-repeat manner to perform one point measurement in the entire irradiation area.

[0091] Furthermore, when the measurement unit 40 is equipped with a focus position detection system, the control device 60 can also adjust the Z position of the wafer surface according to the detection result (output) of the focus position detection system, similar to the description in step S106.

[0092] During the alignment measurement of the entire wafer (one-point measurement of the entire irradiation area) in step S112, when the slider 10 moves in the XY plane, an eccentric load will be applied to the platform 12 as the slider moves. In this embodiment, the control device 60 responds to the X and Y coordinate positions of the slider contained in the measurement information of the first position measurement system 30, and performs feedforward control on each of the three vibration isolation devices 14 in a manner that can offset the influence of the eccentric load, thereby individually controlling the driving force in the Z-axis direction generated by each vibration isolation device 14. Alternatively, the control device 60 may predict the eccentric load applied to the platform 12 based on the known moving 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 isolation devices 14 in a manner that can offset the influence of the eccentric load. Furthermore, in the present embodiment, since the concavo-convex information (hereinafter referred to as holder flatness information) of the wafer holding surface (a surface defined by the upper end surfaces of the plurality of pins of the pin chuck) of the wafer holder WH is obtained in advance by experiments, when the slider 10 is moved during alignment measurement (e.g., one-point measurement of the entire irradiation area), the control device 60 performs feedforward control on the three vibration isolation devices 14 based on the holder flatness information, thereby adjusting the Z position of the stage 12 so that the area including the wafer mark of the measurement object on the surface of the wafer W can be quickly located within the focal depth range of the optical system of the mark detection system MDS. Furthermore, either or both of the feedforward control for offsetting the above-mentioned influence of the eccentric load acting on the stage 12 and the feedforward control based on the holder flatness information may not be implemented.

[0093] Furthermore, when the magnification of the mark detection system MDS can be adjusted, it can be set to a low magnification during search alignment and to a high magnification during alignment measurement. In addition, when the center position deviation and residual rotation error of the wafer W loaded on the slide 10 are small enough to be ignored, step S108 can also be omitted.

[0094] The measurement at one point in the full irradiation area in step S112 detects the measured values of the position coordinates of the sampling irradiation area (sampling irradiation area) in the reference coordinate system used for the subsequent EGA operation. The sampling irradiation area refers to a specific plurality (at least 3) of irradiation areas that are predetermined as those used for the subsequent EGA operation among all the irradiation areas on the wafer W. Also, in the measurement at one point in the full irradiation area, the full irradiation area on the wafer W is the sampling irradiation area. After step S112, proceed to step S124.

[0095] On the other hand, when the determination in step S110 is negative, that is, when setting the B mode, move 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 < I, a predetermined number, for example, 4). Also, the count value i is incremented in step S128 described later. When the determination in this step S114 is affirmative, move to step S120 to perform multi-point measurement of the full irradiation area. Here, the multi-point measurement of the full irradiation area means measuring a plurality of wafer marks for each of all the irradiation areas on the wafer W. The plurality of wafer marks to be measured are predetermined. For example, a plurality of wafer marks arranged in a configuration that can statistically calculate the shape of the irradiation area (shape error compared to the ideal lattice) can be used as the measurement objects. The measurement order is the same as that in the case of the one-point measurement of the full irradiation area in step S112 except for the number of measurement object marks, so the detailed description is omitted. After step S120, move to step S124.

[0096] On the other hand, when the determination in step S114 is negative, move to step S116 to determine whether the count value i is less than K + 1. Here, when the determination in this step S116 is affirmative, the case where the count value i is i ≧ K and i < k + 1 becomes the case where i = K.

[0097] When the judgment in step S116 is affirmative, the process proceeds to step S118, and the wafer mark to be measured for each irradiation area is determined based on the detection results of the wafer marks of K-1 wafers (for example, 3 wafers when K=4) W that have been measured so far. Specifically, for each irradiation area, it is determined whether the detection of one wafer mark is sufficient or whether multiple wafer marks should be detected. If it is the latter, it is also determined which wafer mark is the detection object. For example, the difference (absolute value) between the measured position and the designed position of each of the multiple wafer marks is calculated for each irradiation area, and whether the difference between the maximum value and the minimum value of the difference exceeds a certain threshold value is determined to determine whether multiple wafer marks should be detected for each irradiation area, or the detection of one wafer mark is sufficient. If it is the former, the wafer mark to be detected is determined in a manner that includes, for example, the wafer mark with the largest difference (absolute value) between the measured position and the designed position and the wafer mark with the smallest difference. After step S118, the process proceeds to step S122.

[0098] On the other hand, when the judgment in step S116 is negative, the process moves to step S122. Here, the judgment in step S116 is negative when the count value i satisfies K+1≦i, and the count value must be i=K before, and the wafer mark to be measured for each irradiation area is determined in step S118.

[0099] In step S122, the wafer marks to be measured for each irradiation area determined in step S118 are measured. The order of measurement is the same as the case of measuring one point in the entire irradiation area in step S112, except for the number of measurement target marks. Therefore, detailed description is omitted. After step S122, the process moves to step S124.

[0100] From the description so far, it can be seen that in mode B, multi-point measurement of the entire irradiation area is performed on the wafers from the 1st to the K-1th (for example, the 3rd) wafers in the batch, and measurement of the wafer marks determined for each irradiation area is performed on the wafers from the Kth (for example, the 4th) to the Ith (for example, the 25th) wafers based on the results of the multi-point measurement of the entire irradiation area of the initial K-1 wafers (for example, the 3rd) wafers.

[0101] In step S124, the position information of the wafer mark measured in any one of step S112, step S120 and step S122 is used to perform EGA operation. The so-called EGA operation refers to the statistical operation of the coefficient of the pattern representing the relationship between the position coordinates of the irradiation area and the correction amount of the position coordinates of the irradiation area using the least squares or other statistical operation based on the difference between the design value and the measured value of the position coordinates of the sampled irradiation area after the measurement of the wafer mark (EGA measurement).

[0102] In this embodiment, for example, the correction amount of the position coordinates of the irradiation area compared to the design value is calculated using the following model.

[0103] [Formula 1]

[0104] Here, dx and dy are the correction amounts of the position coordinates of the irradiation area in the X-axis direction and the Y-axis direction compared to the design value, and X and Y are the design position coordinates of the irradiation area in the wafer coordinate system with the center of the wafer W as the origin. That is, the above formula (1) is a polynomial about the design position coordinates X and Y of each irradiation area in the wafer coordinate system with the center of the wafer as the origin, and is a pattern that expresses 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 of the reference coordinate system and the wafer coordinate system is offset by the above-mentioned search alignment, the reference coordinate system and the wafer coordinate system are not particularly distinguished below, and the whole is explained as the reference coordinate system.

[0105] If mode (1) is used, the correction value of the position coordinates of the irradiation area can be obtained from the position coordinates X and Y of the irradiation area of the wafer W. However, in order to calculate this correction value, the coefficients a0, a1, ..., b0, b1, ... must be obtained. After EGA measurement, the coefficients a0, a1, ..., b0, b1, ... of the above formula (1) are obtained using statistical calculations such as the least square method based on the data of the difference between the design value and the measured value of the position coordinates of the sampled irradiation area.

[0106] After determining the coefficients a0, a1, ..., b0, b1, ... of mode (1), the designed position coordinates X and Y of each irradiation area (division area) in the wafer coordinate system are substituted into the mode (1) after the coefficients are determined to obtain the correction values dx and dy of the position coordinates of each irradiation area, thereby obtaining the true arrangement of the plurality of irradiation areas (division areas) on wafer W (including not only linear components but also nonlinear components as deformation components).

[0107] In the case of wafer W that has been exposed, the waveform of the detection signal obtained as a measurement result may not be good for all wafer marks due to the influence of the process up to this point. When the position of the wafer mark with a bad measurement result (waveform of the detection signal) is included in the above EGA calculation, the position error of the wafer mark with a bad measurement result (waveform of the detection signal) will have an adverse effect on the calculation results of the coefficients a0, a1, ..., b0, b1, ...

[0108] Therefore, in this embodiment, the signal processing device 49 sends only the measurement results of the wafer marks with good measurement results to the control device 60, and the control device 60 uses the positions of all wafer marks for which the measurement results are received to perform the above-mentioned EGA operation. In addition, the degree of the polynomial in the above-mentioned formula (1) is not particularly limited. The control device 60 makes the result of the EGA operation and the information related to the mark used for the operation correspond to the identification information of the wafer (such as the wafer number, the lot number), and creates an alignment history data file, which is stored in an internal or external memory device.

[0109] After the EGA calculation of step S124 is completed, the process proceeds to step S126 to unload the wafer W from the slide 10. This unloading is performed by the wafer transfer system 70 and the up-and-down moving components on the slide 10 under the control of the control device 60 in the reverse order of the loading order in step S104.

[0110] In the next step S128, after adding 1 to the count value i of the counter (i←i+1), the process proceeds to step S130 to determine whether the count value i is greater than the total number of wafers in the batch I. If the determination in step S130 is negative, it is determined that the processing of all wafers in the batch has not been completed, and the process returns to step S104 until the determination in step S130 becomes positive, and the process (including the determination) of steps S104 to S130 is repeated.

[0111] When the determination in step S130 is positive, it is determined that the processing of all wafers in the batch has been completed, and a series of processing in this conventional procedure ends.

[0112] As described in detail above, according to the measuring device 100 of the present embodiment, the first position measuring system 30 for measuring the position information in the six-degree-of-freedom direction of the slider 10 that carries and holds the wafer W detects at least the wafer mark on the wafer W by the mark detection system MDS, so that the measuring beam can be continuously irradiated to the grating RG1 from the reading head 32 within the range where the slider 10 moves. Therefore, the first position measuring system 30 can continuously measure the position information within the entire range within the XY plane where the slider 10 moves for the mark detection. Therefore, in the manufacturing stage of the measuring device 100 (including the device startup stage in the semiconductor manufacturing factory), for example, the absolute coordinate position of the slider 10 can be obtained in the XY plane by measuring the long axis of the first position measuring system 30, that is, finding the origin of the orthogonal coordinate system (reference coordinate system) defined by the grid of the grating RG1, and then the absolute position of the mark (not limited to the search mark and wafer mark, but also including other marks, such as the overlap measurement mark (registration mark), etc.) on the wafer W held by the slider 10 obtained by the position information of the slider 10 measured by the first position measuring system 30 and the detection result of the mark detection system MDS in the XY plane can be obtained. In addition, the so-called "absolute position coordinate" in this specification refers to the position coordinate on the above-mentioned reference coordinate system.

[0113] Furthermore, according to the measuring device 100 of the present embodiment, since the position coordinates of the mark on the wafer in the XY plane can be measured, the bare wafer can be exposed in a step-scanning method or a step-and-repeat method using a product reticle formed with an alignment mark with a known positional relationship with the pattern area together with the rectangular pattern area by an exposure device such as a scanner or a stepper, and the absolute coordinates of the alignment mark image on the wafer after exposure are measured by the measuring device 100, that is, the change of the wafer grid (for example, the change of the wafer grid compared to the design) can be managed without using a reference wafer. Moreover, the management of the wafer grid change caused by the device will be described in detail later.

[0114] Furthermore, according to the measuring device 100 of the present embodiment, the control device 60 controls the movement of the slider 10 by the driving system 20, and uses 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 stage 12 and the relative position information of the mark detection system MDS and the stage 12, and uses the mark detection system MDS to obtain the position information of the plurality of marks formed on the wafer W. Therefore, by using the measuring device 100, the position information of the plurality of marks formed on the wafer W can be obtained with good accuracy.

[0115] Furthermore, according to the measuring device 100 of the present embodiment, the control device 60 obtains the measurement information (relative position information of the platform 12 and the mark detection system MDS) measured by the second position measurement system 50 at any time, and controls the position of the platform 12 in the 6-degree-of-freedom direction in real time through the three vibration isolation devices 14 (actuators), so that the position relationship between the detection center of the mark detection system MDS and the measurement point of the first position measurement system that detects the position information of the slide 10 relative to the platform 12 in the 6-degree-of-freedom direction is maintained at a desired relationship at the nm level. Furthermore, the control device 60 controls the driving of the slider 10 by the driving system 20, and obtains the measurement information (position information of the slider 10 relative to the platform 12) measured by the first position measurement system 30 and the measurement information (relative position information of the platform 12 and the mark detection system MDS) measured by the second position measurement system 50, and obtains the position information of the plurality of wafer marks based on the detection signal when the mark detection system MDS is used to detect the mark formed on the wafer W, the measurement information of the first position measurement system 30 obtained when the mark detection system MDS is used to detect the mark formed on the wafer W, and the measurement information of the second position measurement system 50 obtained when the mark detection system MDS is used to detect the mark formed on the wafer W. Therefore, by using the measurement device 100, the position information of the plurality of marks formed on the wafer W can be obtained with good accuracy.

[0116] Furthermore, for example, when the position control of wafer W (wafer stage WST) during exposure described later is performed based on the position information of the measured mark without performing EGA calculation using the position information of the measured mark, the measurement information measured by the second position measurement system 50 may not be used to calculate the position information of the mark. However, in this case, the measurement information of the second position measurement system 50 obtained when the mark formed on wafer W is detected using the mark detection system MDS may be offset and used to correct information of wafer W such as the positioning target value for moving wafer W (wafer stage WST). Alternatively, the movement of reticle R (reticle stage RST) described later during exposure may be controlled by taking the offset into consideration.

[0117] Furthermore, according to the measuring device 100 of the present embodiment, during alignment measurement, the position information of at least one wafer mark is measured for each of I (for example, 98) irradiation areas on the wafer W, and the coefficients a0, a1, ..., b0, b1, ... of the above formula (1) are obtained by using this position information through statistical calculation such as the least square method. Therefore, not only the linear component but also the nonlinear component of the deformation component of the wafer grid can be accurately obtained. Here, the so-called wafer grid refers to a grid formed by connecting the centers of the irradiation areas on the wafer W arranged according to the irradiation area map (data on the arrangement of the irradiation areas formed on the wafer W).

[0118] The correction amount of the position coordinates of the irradiation area of the wafer W obtained by the measuring device 100 (the coefficients a0, a1, ..., b0, b1, ... of the above formula (1)) can be used, for example, to align the wafer position relative to the exposure position when the wafer W is exposed by the exposure device. However, in order to expose the wafer W whose position coordinates have been measured by the measuring device 100 by the exposure device, the wafer W must be loaded onto the wafer stage of the exposure device after being unloaded from the slider 10. Even if the wafer holder WH on the slider 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 difference of the wafer holder. Therefore, even if the position coordinate correction amount of the irradiation area of the wafer W is obtained by the measuring device 100 (the coefficients a0, a1, ..., b0, b1, ... of the above formula (1)), all of these coefficients a0, a1, ..., b0, b1, ... cannot be used directly. However, the low-order components (linear components) below the first order of the position coordinate correction amount of the irradiation area are considered to be affected by the different holding states of the wafer W of each wafer holder, and the high-order components above the second order are almost not affected. The reason is that the high-order components above the second order are mostly considered to be components mainly caused by the deformation of the wafer W caused by the process, and are irrelevant to the wafer holding state of the wafer holder and have no effect.

[0119] According to the above idea, the coefficients a3, a4, ..., a9, ..., and b3, b4, ..., b9, ... of the higher-order components obtained by the measuring device 100 for the wafer W can be directly used as the coefficients of the higher-order components of the position coordinate correction amount of the wafer W in the exposure device. Therefore, on the wafer stage of the exposure device, only a simple EGA measurement (for example, measurement of 3 to 16 wafer marks) is required to obtain the linear component of the position coordinate correction amount of the wafer W. Since the measuring device 100 is another device different from the exposure device, it does not cause a decrease in the yield in the exposure process of the substrate, and the position information of more marks on the substrate can be obtained.

[0120] Furthermore, if alignment measurement of other wafers is performed by the measurement device 100 in parallel with wafer processing using an exposure device including the aforementioned simple EGA measurement and exposure, efficient processing can be performed with almost no reduction in the throughput of wafer processing.

[0121] In the above embodiment, for the sake of simplicity, any one of the A mode and the B mode is set as the measurement mode, but the present invention is not limited thereto. A C mode may be set to detect two or more first-number wafer marks for the entire irradiation area on all wafers in a batch, and a mode (called a D mode) may be set to detect two or more second-number wafer marks for a predetermined irradiation area located at the periphery of the wafer for a partial irradiation area of all wafers in a batch, for example, and detect one wafer mark for each of the remaining irradiation areas. Furthermore, an E mode may be set to select any one of the A mode, the C mode, and the D mode for the remaining wafers in the batch based on the detection results of the wafer marks for the first predetermined number of wafers in the batch.

[0122] In addition, as a measurement mode of the measuring device 100, a partial irradiation area can be measured for all wafers in a batch, for example, one or more wafer marks in 90% or 80% of the irradiation areas, and for the irradiation area located in the center of the wafer, one or more wafer marks in the irradiation area separated by an interval can be measured.

[0123] Furthermore, in the above-mentioned embodiment, although the case where the gratings RG1, RG2a, and RG2b have the X-axis direction and the Y-axis direction as the periodic directions is described, it is not limited to this. As long as the grid portions (two-dimensional gratings) respectively provided in the first position measurement system 30 and the second position measurement system 50 have the two directions intersecting each other in the XY plane as the periodic directions, it will suffice.

[0124] Furthermore, the configuration of the head unit 32 of the first position measurement system 30 and the arrangement of the detection points described in the above embodiment are, of course, only examples. For example, the detection point of the mark detection system MDS and the detection center of the head unit 32 may not coincide in at least one of the X-axis direction and the Y-axis direction. In addition, the arrangement of the head unit of the first measurement system 30 and the grating RG1 (grid unit) may be opposite. That is, the head unit may be provided on the slider 10 and the grid unit may be provided on the platform 12. Furthermore, the first position measurement system 30 does not necessarily have to include the encoder system 33 and the laser interferometer system 35, and the first position measurement system 30 may be configured only with the encoder system. The first position measurement system may be configured using an encoder system that irradiates a beam from the head unit to the grating RG1 of the slider 10 and receives a return beam (diffracted beam) from the grating to measure the position information of the slider 10 in the 6-degree-of-freedom direction relative to the platform 12. In this case, the head configuration of the head unit is not particularly limited. For example, a pair of XZ readers may be provided to irradiate detection beams to two points at the same distance in the X-axis direction relative to a predetermined point on the grating RG1, and a pair of YZ readers may be provided to irradiate detection beams to two points at the same distance in the Y-axis direction relative to a predetermined point. Alternatively, a pair of three-dimensional readers may be provided to irradiate detection beams to two points separated in the X-axis direction of the grating RG1, and an XZ reader or YZ reader may be provided to irradiate detection beams to points at different positions in the Y-axis direction from the above two points. The first position measurement system 30 does not necessarily have to be able to measure the position information of the slide 10 relative to the platform 12 in the six-degree-of-freedom direction, and may be able to measure position information in the X, Y, and θz directions only, for example. In addition, the first position measurement system for measuring the position information of the slide 10 relative to the platform 12 may be arranged between the platform 12 and the slide 10.

[0125] Similarly, the configuration of the second position measurement system 50 described in the above embodiment is only an example. For example, the read heads 52A and 52B may be fixed on the side of the platform 12, and the scales 54A and 54B may be integrally provided with the mark detection system MDS. In addition, although the second measurement system 50 is provided with a pair of read heads 52A and 52B, the second measurement system 50 may only have one read head or may have three or more read heads. 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 the six degrees of freedom. However, the second measurement system 50 does not necessarily have to be able to measure the positional relationship in all six degrees of freedom.

[0126] Furthermore, the above-mentioned embodiment is directed to the case where the slider 10 is suspended and supported on the platform 12 by a plurality of air bearings 18, and the drive system 20 for driving the slider 10 in a non-contact state relative to the platform 12 is composed of a first drive device 20A for driving the slider 10 in the X-axis direction and a second drive device 20B for driving the slider 10 and the first drive device 20A in the Y-axis direction. However, the present invention is not limited thereto, and as the drive system 20, a drive system for driving the slider 10 in six degrees of freedom directions on the platform 12 may be adopted. Such a drive system may be composed of, for example, a magnetic levitation type planar motor. In this case, the air bearings 18 are not required. In addition, the measuring device 100 may be provided with a drive system for driving the platform 12 separately from the vibration isolation device 14.

[0127] In addition, a structure in which the slide 10 can be driven relative to the platform 12 in the X, Y, or θz directions by a magnetically levitated or air-levitated planar motor may be used. In this case, the aforementioned second position measurement system 50 is not necessarily required.

[0128] <<Second Implementation Form>> Next, the second implementation form of the lithography system including the above-mentioned measuring device 100 is explained based on Figures 8 to 10.

[0129] The lithography system 1000 of the second embodiment, as shown in FIG8, comprises an exposure device 200, a measurement device 100, and a substrate processing device 300 connected to each other. Here, a coating and developing device (C / D) is used as the substrate processing device 300, and therefore, it is appropriately described as C / D300 in the following description. The lithography system 1000 is installed in a clean room.

[0130] In a general lithography system, such as disclosed in the specification of U.S. Patent No. 6,698,944, an inline interface section having a wafer transfer system for connecting the two is arranged between the exposure device and the substrate processing device (C / D) in the chamber. On the other hand, as shown in FIG. 8 , the lithography system 1000 of the second embodiment is provided with a measurement device 100 between the exposure device 200 and the C / D 300 instead of the inline interface section.

[0131] The exposure device 200, C / D 300 and measuring device 100 of the lithography system 1000 all have chambers, and the chambers are arranged adjacent to each other. The exposure control device 220 of the exposure device 200, the coating and development control device 320 of the C / D 300, and the control device 60 of the measuring device 100 are connected to each other through a local area network (LAN) 500, and the three communicate with each other. The memory device 400 is also connected to the LAN 500.

[0132] The exposure device 200 is, for example, a projection exposure device (scanner) of a step & scan method. FIG. 9 shows the interior of the chamber of the exposure device 200 with some of the components omitted.

[0133] As shown in FIG9 , exposure device 200 includes an illumination system IOP, a reticle stage RST for holding a reticle R, a projection unit PU for projecting an image of a pattern formed on reticle R onto a wafer W coated with a sensor (resist), a wafer stage WST for holding wafer W and moving it in an XY plane, and a control system thereof. Exposure device 200 includes a projection optical system PL having an optical axis AX in the Z-axis direction parallel to the optical axis AX1 of the mark detection system MDS.

[0134] The illumination system IOP includes a light source and an illumination optical system connected to the light source through a light-transmitting optical system, and illuminates a slit-shaped illumination area IAR extending in the X-axis direction (the direction perpendicular to the paper surface in FIG. 9 ) on the reticle R set (limited) by a reticle blind (shielding system) with illumination light (exposure light) IL at a substantially uniform illumination. The configuration of the illumination system IOP is disclosed in, for example, the specification of U.S. Patent Application Publication No. 2003 / 0025890. Here, as an example of illumination light IL, ArF excimer laser light (wavelength 193 nm) is used.

[0135] Reticle stage RST is disposed below illumination system IOP in FIG9 . Reticle stage RST can be driven slightly in a horizontal plane (XY plane) and in a scanning direction (Y-axis direction of the left-right direction in the paper plane of FIG9 ) within a predetermined travel range on a reticle stage platform (not shown) by, for example, a reticle stage driving system 211 (not shown in FIG9 , refer to FIG10 ) including a linear motor.

[0136] A reticle R is mounted on the -Z side surface (pattern surface) of reticle stage RST, and a pattern area is formed thereon, and a plurality of marks are formed thereon, whose positional relationship with the pattern area is known. The position information (including the rotation information in the θz direction) of reticle stage RST in the XY plane is detected at any time by a reticle laser interferometer (hereinafter referred to as "reticle interferometer") 214 through a movable mirror 212 (or a reflection surface formed on the end surface of reticle stage RST) with a resolution of, for example, about 0.25 nm. The measurement information of reticle interferometer 214 is supplied to exposure control device 220 (refer to FIG. 10 ). In addition, the position information in the XY plane of reticle stage RST can also be measured by an encoder instead of reticle laser interferometer 214.

[0137] Projection unit PU is arranged below reticle stage RST in FIG9 . Projection unit PU includes lens barrel 240 and projection optical system PL held in lens barrel 240 . Projection optical system PL is, for example, bilaterally telecentric and has a predetermined projection magnification (e.g., 1 / 4, 1 / 5, or 1 / 8). Reticle R is arranged in such a manner that the first surface (object surface) of projection optical system PL is substantially consistent with the pattern surface, and wafer W coated with a resist (sensing agent) on the surface is arranged on the second surface (image surface) side of projection optical system PL. Therefore, when illumination area IAR on reticle R is illuminated by illumination light IL from illumination system IOP, a reduced image (reduced image of a part of the circuit pattern) of reticle R in illumination area IAR is formed through projection optical system PL in an area (hereinafter also referred to as exposure area) IA on wafer W conjugate with illumination area IAR. By synchronously driving reticle stage RST and wafer stage WST, reticle R is moved in the scanning direction (Y-axis direction) relative to illumination area IAR (illumination light IL), and wafer W is moved in the scanning direction (Y-axis direction) relative to exposure area IA (illumination light IL), thereby performing scanning exposure on an irradiation area (division area) on wafer W, and transferring the pattern of reticle R to the irradiation area.

[0138] As the projection optical system PL, a refractive system is used, for example, which is composed of a plurality of refractive optical elements (lens elements) arranged only along the optical axis AX parallel to the Z-axis direction, for example, about 10 to 20 pieces. Among the plurality of lens elements constituting this projection optical system PL, the plurality of lens elements on the object surface side (the reticle R side) are movable lenses that can be displaced and driven in the Z-axis direction (the optical axis direction of the projection optical system PL) and the tilt direction relative to the XY plane (that is, the θx direction and the θy direction) by a driving element not shown in the figure, such as a piezoelectric element. The imaging characteristic correction controller 248 (not shown in FIG. 9, refer to FIG. 10) independently adjusts the voltage applied to each driving element according to the instruction from the exposure control device 220, and drives each movable lens individually accordingly, so as to adjust various imaging characteristics (magnification, distortion, astigmatism, coma aberration, field curvature, etc.) of the projection optical system PL. Furthermore, instead of moving the movable lens, an airtight chamber may be provided between adjacent specific lens elements in the lens barrel 240, and the pressure of the gas in the airtight chamber may be controlled by the imaging characteristic correction controller 248, or a configuration may be adopted in which the central wavelength of the illumination light IL can be switched by the imaging characteristic correction controller 248. With such configurations, the imaging characteristics of the projection optical system PL can also be adjusted.

[0139] The wafer stage WST is driven on the wafer stage platform 222 in the X-axis direction and the Y-axis direction with a predetermined stroke by a stage driving system 224 (in FIG. 9 , for convenience, it is represented by a block) including a planar motor or a linear motor, and is slightly driven in the Z-axis direction, the θx direction, the θy direction, and the θz direction. The wafer W is held on the wafer stage WST by a wafer holder (not shown) by vacuum adsorption or the like. In this second embodiment, the wafer holder can adsorb and hold a 300 mm wafer. In addition, a stage device can be used that replaces the wafer stage WST and has a first stage that moves in the X-axis direction, the Y-axis direction, and the θz direction, and a second stage that slightly moves in the Z-axis direction, the θx direction, and the θy direction on the first stage. In addition, either or both of the wafer stage WST and the wafer holder of the wafer stage WST can be referred to as a "second substrate holding member."

[0140] The position information (rotation information (including the yaw amount (rotation amount θz in the θz direction), pitch amount (rotation amount θx in the θx direction), and roll amount (rotation amount θy in the θy direction)) of wafer stage WST in the XY plane is detected at any time by a laser interferometer system (hereinafter referred to as the interferometer system) 218 through a movable mirror 216 (or a reflective surface formed on the end face of wafer stage WST) with a resolution of, for example, about 0.25 nm. In addition, the position information of wafer stage WST in the XY plane can also be measured by an encoder system instead of interferometer system 218.

[0141] The measurement information of interferometer system 218 is supplied to exposure control device 220 (see FIG. 10 ). Exposure control device 220 controls the position of wafer stage WST in the XY plane (including rotation in the θz direction) through stage drive system 224 based on the measurement information of interferometer system 218 .

[0142] Although omitted in FIG9 , the position and tilt of the surface of the wafer W in the Z-axis direction are measured by a focus sensor AFS (see FIG10 ) composed of a multi-point focus position detection system of an oblique incidence method disclosed in, for example, U.S. Patent No. 5,448,332. The measurement information of the focus sensor AFS is also supplied to the exposure control device 220 (see FIG10 ).

[0143] Furthermore, a reference plate FP is fixed on wafer stage WST, the surface of which is at the same height as the surface of wafer W. On the surface of this reference plate FP, a first reference mark for base line measurement of alignment detection system AS and a pair of second reference marks for detection by reticle alignment detection system AS described later are formed.

[0144] An alignment detection system AS for detecting the alignment mark or the first reference mark formed on the wafer W is provided on the side of the lens barrel 240 of the projection unit PU. As the alignment detection system AS, a FIA (Field Image Alignment) system is used, which is a type of image processing type alignment sensor (Alignment sensor) that uses broadband light such as a halogen lamp to illuminate the mark and performs image processing on the image of the mark to measure the mark position. In addition, a diffraction light interference type alignment system may be used instead of the image processing type alignment detection system AS or together with the alignment detection system AS.

[0145] In exposure device 200, further, a pair of reticle alignment detection systems 213 (not shown in FIG. 9 , refer to FIG. 10 ) are provided above reticle stage RST at a predetermined distance in the X-axis direction, which can simultaneously detect a pair of reticle marks on reticle R mounted on reticle stage RST at the same Y position. The detection result of the marks of reticle alignment detection system 213 is supplied to exposure control device 220.

[0146] FIG10 shows the input / output relationship of the exposure control device 220 in a block diagram. As shown in FIG10, in addition to the above-mentioned components, the exposure device 200 also includes a wafer transfer system 270 connected to the exposure control device 220 for transferring wafers. The exposure control device 220 includes a microcomputer or a workstation, etc., and coordinates and controls the entire device including the above-mentioned components. The wafer transfer system 270 is composed of, for example, a horizontal multi-joint robot.

[0147] Returning to FIG. 8, although not shown in the figure, C / D 300 has, for example, a coating section for coating the wafer with an inductive agent (resist), a developing section for developing the wafer, a baking section for performing pre-baking (PB) and post-exposure baking (PEB), and a wafer transport system (hereinafter, for convenience, referred to as the C / D internal transport system). C / D 300 further has a temperature control section 330 for regulating the temperature of the wafer. The temperature control section 330 is generally a cooling section, for example, having a flat plate (temperature control device) called a cooling plate. The cooling plate is cooled, for example, by circulating cooling water. In addition to this, there are also cases where electronic cooling using the Peltier effect is used.

[0148] The memory device 400 includes a management device connected to the LAN 500 and an external memory element connected to the management device via a communication path such as SCSI (Small Computer System Interface).

[0149] In the lithography system 1000 of the second embodiment, the measurement device 100, the exposure device 200 and the C / D 300 are all equipped with a barcode reader (not shown), and the identification information of each wafer, such as the wafer number, the lot number, etc., is appropriately read by the barcode reader during wafer transportation in each of the wafer transportation system 70 (refer to FIG. 6 ), the wafer transportation system 270 (refer to FIG. 10 ) and the C / D internal transportation system (not shown). In the following, for the sake of simplicity, the description of the reading of the identification information of each wafer using the barcode reader is omitted.

[0150] In the lithography system 1000, a plurality of wafers are processed continuously by each of the exposure device 200, the C / D 300 and the measurement device 100 (hereinafter, appropriately referred to as the three devices 100, 200, 300). In the lithography system 1000, in order to maximize the throughput of the entire system, the entire processing sequence is determined, for example, in such a way that the processing time of other devices completely overlaps the processing time of the device that requires the most processing time.

[0151] The following describes the operation flow of the lithography system 1000 for continuously processing a plurality of wafers.

[0152] First, the first wafer (W 1) is taken out from the wafer carrier arranged in the chamber of C / D 300 by the C / D internal transport system (e.g., a horizontal multi-jointed robot) and moved into the coating section. Accordingly, the coating section starts the coating of the resist. When the coating of the resist is completed, the C / D internal transport system takes the wafer W 1 out of the coating section and moves it into the baking section. Accordingly, the heating treatment (PB) of the wafer W 1 is started in the baking section. Next, when the PB of the wafer is completed, the C / D internal transport system takes the wafer W 1 out of the baking section and moves it into the temperature control section 330. Accordingly, the cooling of the wafer W 1 is started by the cooling plate inside the temperature control section 330. This cooling is performed at a temperature that does not affect the exposure device 200, generally, for example, the target temperature of the air conditioning system of the exposure device 200 determined in the range of 20 to 25°C as the target temperature. Generally speaking, at the time of being transported into the temperature control unit 330 , the wafer temperature is within the range of ±0.3[° C.] relative to the target temperature, and the temperature is controlled by the temperature control unit 330 to within the range of ±10[mK] of the target temperature.

[0153] Next, when cooling (temperature control) is completed in the temperature control unit 330 , the wafer W1 is placed on the first substrate transfer unit provided between the C / D 300 and the measurement device 100 by the C / D internal transfer system.

[0154] In C / D300, a series of processes similar to the above, such as resist coating, PB, cooling, and wafer transfer operations accompanying such a series of processes, are sequentially performed, and the wafers are sequentially placed on the first substrate transfer unit. In fact, more than two coating units and C / D internal transfer systems can be respectively arranged in the chamber of C / D300 to perform parallel processing on multiple wafers, thereby shortening the time required for pre-exposure processing.

[0155] In the measuring device 100, the wafer W1 before exposure, which is sequentially placed on the first substrate conveying part by the C / D inner conveying system, is loaded onto the slide 10 by the cooperation of the wafer conveying system 70 and the up-and-down moving member on the slide 10 in the order previously described in the first embodiment. After loading, the measuring device 100 performs wafer alignment measurement in the set measurement mode, and the control device 60 obtains the position coordinate correction amount of the irradiation area of the wafer W (the coefficients a0, a1, ..., b0, b1, ... of the above formula (1)).

[0156] The control device 60 matches the correction amount of the calculated position coordinates (the coefficients a0, a1, ..., b0, b1, ... of the above formula (1)), the information of the wafer mark using the mark position information in the calculation of the correction amount, the information of the measurement mode, and the information of all wafer marks with good detection signals, etc., with the identification information of the wafer W1 (wafer number, batch number) to create alignment history data (file), and stores it in the memory device 400.

[0157] After that, the wafer W1 after the alignment measurement is placed by the wafer transfer system 70 on the loading side substrate placement part of the second substrate transfer part provided inside the chamber of the exposure device 200 and near the measurement device 100. Here, the second substrate transfer part is provided with a loading side substrate placement part and an unloading side substrate placement part.

[0158] Afterwards, in the measurement device 100, alignment measurement, creation of alignment history data (file), and wafer transportation are repeatedly performed on the second and subsequent wafers in the same order as the wafer W1.

[0159] The wafer W1 placed on the loading side substrate placement section is transferred to a predetermined standby position inside the exposure device 200 by the wafer transfer system 270. However, the first wafer W1 is not placed on standby at the standby position, but is immediately placed on the wafer stage WST by the exposure control device 220. The loading of the wafer is performed by the exposure control device 220 in the same manner as that performed in the measurement device 100, using the up-and-down moving member (not shown) on the wafer stage WST and the wafer transfer system 270. After loading, the wafer on the wafer stage WST is subjected to the same search alignment as described above, and wafer alignment of the EGA method using, for example, 3 to 16 degree irradiation areas as the alignment irradiation areas is performed using the alignment detection system AS. During wafer alignment in this EGA method, the exposure control device 220 of the exposure device 200 searches the alignment history data file stored in the memory device 400 using the identification information (e.g., wafer number, lot number) of the wafer (target wafer) to be aligned and exposed as a key to obtain the alignment history data of the target wafer. Furthermore, after the predetermined preparation operation, the exposure control device 220 performs the following wafer alignment based on the information of the measurement mode contained in the acquired alignment history data.

[0160] First, the case of information including mode A is described. In this case, wafer marks corresponding to the number of alignment irradiation areas are selected as detection targets from wafer marks included in the alignment history data and whose position information is measured by the measuring device 100 (position information of the mark is used in the calculation of the correction amount), and the alignment detection system AS is used to detect the wafer marks of the detection targets, and the position information of each wafer mark of the detection target is calculated based on the detection result and the position of the wafer stage WST during the detection (measurement information measured by the interferometer system 218), and the EGA operation is performed using the position information to calculate the coefficients of the equation (2).

[0161] [Formula 2]

[0162] Next, 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) included in the alignment history data, and uses a polynomial related to the position coordinates X, Y of each exposure area design in the wafer coordinate system represented by the equation (3) containing the replaced coefficients as the origin to obtain the correction amount (alignment correction component) dx, dy of the position coordinates of each exposure area. Based on this correction amount, a target position (hereinafter referred to as the positioning target position for convenience) for correcting the wafer grid and for aligning the exposure position (projection position of the reticle pattern) when exposing each exposure area is determined. In addition, although the present embodiment is not a static exposure method, but a scanning exposure method is used for exposure, for convenience, it is called the positioning target position.

[0163] [Formula 3]

[0164] Furthermore, in the exposure device 200, the rotation of the reference coordinate system (stage coordinate system) that specifies the movement of the wafer stage WST and the wafer coordinate system are offset by search alignment, so there is no need to specifically distinguish between the reference coordinate system and the wafer coordinate system.

[0165] Next, the case of setting the B mode is described. In this case, the exposure control device 220 determines the positioning target position for correcting each shot area of the wafer grid in the same order as the above-mentioned A mode. However, in this case, the alignment history data includes a plurality of wafer marks for a plurality of shot areas and one wafer mark for each of the remaining shot areas, and the wafer mark with a good detection signal is used as the wafer mark of the mark position information used in calculating the correction amount.

[0166] Therefore, in addition to determining the positioning target position of each of the above-mentioned irradiation areas, the exposure control device 220 selects the number of wafer marks required for obtaining the shape of the irradiation area from the plurality of wafer marks for the above-mentioned plurality of irradiation areas, and uses the position information (measured values) of these wafer marks to perform a statistical operation (also called multi-point EGA operation in the irradiation area) using the least square method in the model of [Formula 7] disclosed in the specification of U.S. Patent No. 6,876,946, for example, to obtain the shape of the irradiation area. Specifically, the wafer rotation (θ), the orthogonality error (w) of the wafer, and the wafer calibration (rx) in the x direction and the wafer calibration (ry) in the y direction are obtained from the 10 parameters in the model of [Formula 7] disclosed in the specification of U.S. Patent No. 6,876,946. In addition, the multi-point EGA operation in the irradiation area has been disclosed in detail in the above-mentioned U.S. Patent No. 6,876,946, so a detailed description thereof is omitted.

[0167] Next, exposure control device 220 performs position control of wafer stage WST according to the positioning target position, while performing exposure of each irradiation area on wafer W1 in a step & scan manner. Here, when the shape of the irradiation area is obtained by using multi-point EGA measurement in the irradiation area, at least one of the relative scanning angle between reticle stage RST and wafer stage WST, the scanning speed ratio, the relative position of at least one of reticle stage RST and wafer stage WST to the projection optical system, the imaging characteristics (aberration) of projection optical system PL, and the wavelength of illumination light (exposure light) IL is adjusted during scanning exposure to deform the projection image of the pattern of reticle R through projection optical system PL in accordance with the shape of the irradiation area. Here, the adjustment of the imaging characteristics (aberration) of projection optical system PL and the adjustment of the center wavelength of illumination light IL are performed by exposure control device 220 through imaging characteristics correction controller 248.

[0168] In parallel with the EGA wafer alignment and exposure of the wafer (wafer W1 in this case) on the wafer stage WST, the measuring device 100 performs wafer alignment measurement and creates alignment history data on the second wafer (wafer W2) in the set mode in the above-mentioned sequence.

[0169] Before the exposure of the wafer (in this case, wafer W1) on the wafer stage WST is completed, the measurement processing of the measurement device 100 is completed, and the second wafer W2 is placed on the loading side substrate placement portion by the wafer transfer system 70, and is transferred to a predetermined standby position inside the exposure device 200 by the wafer transfer system 270, and waits at the standby position.

[0170] When the exposure of wafer W1 is completed, wafer W1 and wafer W2 are replaced on the wafer stage, and the replaced wafer W2 is subjected to the same wafer alignment and exposure as described above. In addition, if the action of transporting wafer W2 to the standby position is not completed before the exposure of the wafer on the wafer stage (wafer W1 in this case) is completed, the wafer stage will stand by near the standby position while holding the exposed wafer.

[0171] The wafer W2 after the replacement is aligned with the wafer and the wafer transfer system 270 transfers the exposed wafer W1 to the unloading side substrate placement portion of the second substrate transfer portion.

[0172] Afterwards, the wafer transfer system 70, as described above, performs the wafer alignment measurement performed by the measuring device 100 in parallel, and repeatedly performs the actions of transferring the exposed wafer from the unloading side substrate mounting portion and placing it on the first substrate transfer portion, and of removing the wafer after measurement but before exposure from the slide 10 and transferring it to the loading side substrate mounting portion in a predetermined order.

[0173] As mentioned above, the exposed wafer which is transported by the wafer transport system 70 and placed on the first substrate transport unit is transported into the baking unit by the C / D inner transport system, and PEB is performed by the baking device in the baking unit. In the baking unit, multiple wafers can be accommodated at the same time.

[0174] 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, and development begins using the developing device in the developing section.

[0175] When the development of the wafer is completed, the wafer is taken out of the development section by the C / D transport system and moved into a predetermined storage layer in the wafer carrier. After that, in C / D 300, the second and subsequent wafers that have completed exposure are repeatedly subjected to PEB, development, and wafer transport in the same order as wafer W1.

[0176] As described above, according to the lithography system 1000 of the second embodiment, the wafer alignment measurement using the measuring device 100 can be performed in parallel with the operation of the exposure device 200, and the full irradiation area EGA using the full irradiation area as the sample irradiation area can be performed in parallel with the wafer alignment and exposure operation of the exposure device 200. In addition, since the coefficients of the high-order components in the pattern obtained by the full irradiation area EGA can also be directly used in the exposure device 200, the exposure device 200 only needs to perform alignment measurement using several irradiation areas as the irradiation area to obtain the coefficients of the low-order components of the above pattern. By using the low-order component coefficients and the high-order component coefficients obtained by the measuring device 100, the positioning target position when each irradiation area is exposed can be calculated with the same good accuracy as when the low-order and high-order component coefficients of the pattern (1) are obtained by the exposure device 200. Therefore, the overlap accuracy between the image of the reticle pattern during exposure and the pattern formed in each exposure area on the wafer can be improved without reducing the throughput of the exposure device 200.

[0177] Furthermore, in the lithography system 1000 of the second embodiment, the case where the coefficients of the first-order and lower-order components of the above-mentioned pattern are obtained by the exposure device 200, and the coefficients of the first-order and lower-order components and the coefficients of the second-order and higher-order components of the above-mentioned pattern obtained by the measuring device 100 are used is described. However, the invention is not limited thereto, and for example, the coefficients of the second-order and lower-order components of the above-mentioned pattern may be obtained from the detection results of the alignment mark in the exposure device 200, and the coefficients of the second-order and lower-order components and the coefficients of the third-order and higher-order components of the above-mentioned pattern obtained by the measuring device 100 may be used. Alternatively, for example, the coefficients of the third-order and lower-order components of the above-mentioned pattern may be obtained from the detection results of the alignment mark in the exposure device 200, and the coefficients of the third-order and lower-order components and the coefficients of the fourth-order and higher-order components of the above-mentioned pattern obtained by the measuring device 100 may be used. That is, the coefficients of the (N-1)th order (N is an integer greater than or equal to 2) or less components of the above-mentioned pattern can be obtained from the detection results of the alignment mark in the exposure device 200, and the coefficients of the (N-1)th order or less components and the coefficients of the Nth order or higher components of the above-mentioned pattern obtained by the measuring device 100 can be used.

[0178] Furthermore, in the lithography system 1000, when the measurement unit 40 of the measurement device 100 is equipped with the aforementioned multi-point focus position detection system, the measurement device 100 can perform flatness measurement (also called focus mapping) of the wafer W together with the wafer alignment measurement. In this case, by using the flatness measurement result, it is not necessary to perform flatness measurement with the exposure device 200, and the focus and leveling control of the wafer W during exposure can be performed.

[0179] In the second embodiment, the target is a 300 mm wafer, but it is not limited thereto and may be a 450 mm wafer with a diameter of 450 mm. Since the wafer alignment can be performed by the measuring device 100 separately from the exposure device 200, even if it is a 450 mm wafer, it will not cause a decrease in the exposure processing yield, and it is possible to perform, for example, full-point EGA measurement.

[0180] Although not shown in the figure, in the lithography system 1000, the exposure device 200 and the C / D 300 can be connected in series, and the measuring device 100 can be arranged on the opposite side of the C / D 300 from the exposure device 200. In this case, the measuring device 100 can be used for the same alignment measurement as described above, for example, on a wafer before resist coating (hereinafter referred to as pre-measurement). Alternatively, the measuring device 100 can be used for positional offset measurement of the overlay offset measurement mark on a wafer after development (overlay offset measurement), and can also be used for pre-measurement and overlay offset measurement.

[0181] <<Change Management of Wafer Grid>> Next, the wafer grid management method caused by the exposure device using the measurement device 100 is described by taking the case of being applied to the lithography system 1000 as an example. FIG11 schematically shows the processing flow in the wafer grid management method at this time.

[0182] First, in step S202, the bare wafer (for convenience, wafer W0) is exposed by exposure device 200 using product reticle R in a step & scan manner. Here, on reticle R, a mark (transferred to the wafer to form a wafer mark) is formed on its pattern surface together with the rectangular pattern area, in its surrounding area or inside the pattern area (when multiple wafers are taken for one irradiation area), etc. Here, wafer W0 is an unexposed wafer, and its surface is coated with a resist (photoresist) with C / D300. Therefore, when wafer W0 is exposed, alignment is not performed, and the drive control of reticle stage RST and wafer stage WST is performed by exposure control device 220 according to the design value. By the exposure in step S202, a transfer image (latent image) of I (for example, 98) rectangular pattern areas arranged in a matrix and marks of each irradiation area known in the design corresponding to the positional relationship of each irradiation area is formed on the photoresist layer on the surface of the wafer W0.

[0183] Next, in step S204, the exposed wafer W0 is unloaded from the wafer stage WST and moved into the developing section of the C / D 300. Specifically, the wafer W0 is transported by the wafer transport system 270 and the wafer transport system 70 and placed on the first substrate transport section provided between the C / D 300 and the measuring device 100. Next, the wafer W0 is moved into the developing section of the C / D 300 by the C / D internal transport system.

[0184] Next, in step S206, the wafer W0 is developed by the developing device of the developing section of the C / D 300. After the development, a photoresist image of a wafer mark of each irradiation area (hereinafter referred to as a wafer mark) having a positional relationship corresponding to each irradiation area and known in the design and arranged in a matrix is formed on the wafer W0.

[0185] Next, in step S208, the wafer W0 after development is taken out from the C / D 300 and loaded on the slider 10 of the measuring device 100. Specifically, the wafer W0 is taken out from the developing part by the C / D internal transfer system and placed on the first substrate transfer part. The wafer W0 is transferred from the first substrate transfer part to the top of the slider 10 located at the loading position by the wafer transfer system 70 of the measuring device 100 and loaded on the slider 10.

[0186] Next, in step S210, the control device 60 performs the aforementioned one-point measurement of the entire irradiation area on the wafer W0 that has completed development, and obtains the absolute position coordinates of each wafer mark. That is, 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 respectively detect one wafer mark corresponding to each of I (for example, 98) irradiation areas, and obtains the absolute position coordinates (X, Y) of each wafer mark corresponding to each of I irradiation areas on the wafer W0 based on the detection results of each of I wafer marks and the absolute position coordinates (X, Y) of the slider 10 when each of I wafer marks is detected. At this time, the control device 60 uses the Abbe errors in the X-axis direction and the Y-axis direction of the first position measurement system 30 and the measurement values in the X-axis direction and the Y-axis direction of the second position measurement system 50 as offsets based on the measurement values in the θx direction and the θy direction of the slide 10 measured by the first position measurement system 30, and calculates the absolute position coordinates (X, Y) of I wafer mark.

[0187] Next, in step S212, the control device 60 uses the obtained absolute position coordinates of the I marks to obtain the change information of the arrangement (wafer grid) of the I irradiation areas on the wafer W0. For example, the control device 60 obtains the measured value of the absolute position coordinates (X, Y) of each of the I irradiation areas from the absolute position coordinates of the I wafer marks according to the known positional relationship between the wafer marks and the centers of the irradiation areas, and obtains the coefficients a0, a1, ..., b0, b1, ... of the above formula (1) based on the measured value of the absolute position coordinates (X, Y) of each of the I irradiation areas and the difference between the position coordinates (X, Y) of each irradiation area and the design value by using statistical calculations such as the least square method. Here, the obtained coefficients a0, a1, ..., b0, b1, ... are substituted into formula (1), and the formula (1) after the coefficients are determined is used as the variation information of the wafer grid and stored in the internal memory (or memory device 400).

[0188] Alternatively, the control device 60 obtains the measured values of the absolute position coordinates (X, Y) of each of I irradiation areas from the absolute position coordinates of I wafer mark based on the known positional relationship between the wafer mark and the center of the irradiation area, and creates a graph consisting of data on the measured values of the absolute position coordinates (X, Y) of each of the I irradiation areas and the difference between the position coordinates (X, Y) of each irradiation area and the design values, and stores this graph in the memory (or memory device 400) as wafer grid change information.

[0189] In this way, the variation between the wafer grid and the design value can be calculated at any time to manage the variation.

[0190] The next step S214 is performed as needed. In step S214, the control device 60 compares the change information of the difference between the wafer grid and the design value obtained in step S210 with the change information of the wafer grid as a reference stored in advance in the memory (or the memory device 400) to obtain the change amount of the wafer grid from the change of the wafer grid as a reference. Through the processing of this step S214, it is possible to manage the error of the arrangement of the irradiation area caused by the error of the stage grid between different exposure devices, or the error of the arrangement of the irradiation area caused by the error of the stage grid between different time points of the same exposure device.

[0191] If it is the former, before the processing of step S214, a scanning stepper different from the exposure device 200 is used to use a reticle R to expose another bare wafer different from the wafer W0 in the same way as the aforementioned step S202, and the exposed wafer is processed in the same way as steps S204~S212 to obtain the change information of the wafer grid serving as a reference and store it in the memory (or memory device 400).

[0192] If it is the latter, before the processing of step S214, another wafer different from wafer W0 is processed in the same way as steps S202 to S208 to obtain the variation information of the wafer grid serving as a reference and store it in the memory (or memory device 400).

[0193] As can be seen from the above description, the management method of this embodiment can manage the change of the wafer grid caused by the device without using the reference wafer. Therefore, the following undesirable situations that occur when using the reference wafer can be avoided.

[0194] That is, the use of the reference wafer is a struggle because the reference wafer is used in turn by multiple exposure devices. The reference wafer is generally not made in one piece but in multiple pieces, so the individual differences between the reference wafers must be guaranteed. In addition, the reference wafer may be damaged or gradually deteriorate after use. Furthermore, the management method of the wafer grid using the reference wafer is to expose the reference wafer after coating the surface of the reference wafer with a resist, and then remove the resist and clean the reference wafer after completing the necessary treatment. After repeating this procedure, scratches may appear on the surface. In addition, marks of the clamping member (pin chuck, etc.) of the wafer holder may also appear on the back of the reference wafer, thereby causing the reference wafer to be adsorbed and deformed, resulting in deformation of the wafer grid.

[0195] On the other hand, not using a reference wafer also has the following advantages. a. There is no need to worry about the lack of reference wafers and serial numbers, and measurements (corrections) can be performed when changes in the wafer grid are to be measured (corrections are to be made). b. Since bare wafers can be used instead of reference wafers, quality management can be easily performed. c. The wafer grid can be managed using the product exposure area map and product reticle. That is, the wafer grid can be managed using the overlap measurement marks or alignment marks attached to the product reticle. As a result, there is no need for a dedicated reticle for quality management. In addition, since the product exposure area map itself can be used for quality management, not only can the errors dependent on the location be measured, but also the scanning speed and acceleration, and the variation of the wafer grid caused by all the errors caused by the product exposure action can be measured. Therefore, corrections can be made based on the measurement results to completely eliminate the compromise described previously.

[0196] In the lithography system 1000 of the second embodiment, for example, when the overall wafer processing throughput of the lithography system 1000 is not reduced to an excessively low level, the wafer after development can be loaded again on the slide 10 of the measurement device 100 in the same order as the wafer before exposure after the PB, and the position offset measurement of the overlay offset measurement mark (such as the box in box mark, etc.) formed on the wafer can be performed. That is, since the measurement device 100 can perform absolute value measurement of the mark on the wafer (using the first position measurement system 30 on the reference coordinate system), it is not only suitable as a measurement device for wafer alignment measurement, but also for position offset measurement of the overlay offset measurement mark, which is a type of relative position measurement.

[0197] <<Overlay Measurement>> Next, the overlay measurement method using the measuring device 100 is described by taking the case where it is applied to the lithography system 1000 as an example. FIG12 schematically shows the processing flow in the overlay measurement method at this time.

[0198] First, in step S302, in the coating section of C / D300, resist (photoresist) is coated on a wafer (referred to as wafer W11) that has been exposed to the first layer (bottom layer) by an exposure device different from the exposure device 200, such as a scanner or a stepper. On the wafer W11 before resist coating, wafer marks whose design positional relationship with the exposure region is known and the first mark for measuring overlap offset (to be more precise, the photoresist image of the first mark (also appropriately referred to as the first mark image)) are formed in a manner corresponding to each exposure region by exposure of the bottom layer together with a plurality of, for example, I (I is, for example, 98) exposure regions. In this case, the design positional relationship of each of the I first mark images is also known.

[0199] Next, in step S304, the wafer W11 coated with the photoresist is loaded onto the wafer stage WST of the exposure device 200 after undergoing the same predetermined processing as the wafer W1. Specifically, the wafer W11 is loaded onto the wafer stage WST after undergoing the heating treatment (PB) in the baking section, the temperature adjustment in the temperature adjustment section 330, and the alignment measurement (here, the measurement is set as the A mode) performed by the measurement device 100.

[0200] Next, in step S306, the exposure control device 220 of the exposure device 200 uses the alignment detection system AS to perform the same search alignment as described above on the wafer W11 on the wafer stage WST, and performs wafer alignment in an EGA manner using, for example, 3 to 16 degree irradiation areas as alignment irradiation areas.

[0201] Next, in step S308, the exposure control device 220 calculates the correction values (alignment correction components) dx and dy of the position coordinates of each exposure area expressed by the aforementioned formula (3) based on the result of wafer alignment, and determines the positioning target position for correcting the wafer grid during exposure of each exposure area based on this correction value.

[0202] Next, in step S310, exposure device 200 performs exposure of the second layer (the upper layer with the first layer as the bottom layer) on each irradiation area on wafer W11 by step & scan while controlling the position of wafer stage WST according to the positioning target position. At this time, exposure device 200 uses a reticle (for convenience, reticle R11) with a second mark formed corresponding to the first mark image on wafer W11 for exposure. Therefore, by exposing the second layer, the pattern area of reticle R11 is overlapped and transferred to one irradiation area on wafer W11, and a transfer image of one second mark arranged in a positional relationship corresponding to the positional relationship of one first mark is formed.

[0203] Next, in step S312, the wafer W11 after the second layer exposure is carried into the developing section of the C / D300 after the same processing as the wafer W1 after the exposure. Specifically, the wafer W11 is carried by the wafer conveying system 270 to the unloading side substrate loading section of the second substrate conveying section, and is carried from the unloading side substrate loading section to the first substrate conveying section by the wafer conveying system 70, and then carried into the baking section of the C / D300 by the C / D internal conveying system, and PEB is performed by the baking device in the baking section. After the PEB is completed, the wafer W11 is taken out of the baking section by the C / D internal conveying system and carried into the developing section.

[0204] Next, in step S314, the developing device in the developing section develops the wafer W11 on which the transfer images of the plurality of second marks are formed. By this development, a group of second mark images corresponding to the first mark images is formed on the wafer W11 together with one irradiation area at a predetermined positional relationship, and becomes a substrate to be measured during overlap measurement. That is, a substrate to be measured during overlap measurement (overlap measurement target substrate) is produced in this way. Here, as the group of second mark images corresponding to the first mark images, for example, a photoresist image of a stacked box (box in box) mark composed of an outer box mark and an inner box mark arranged inside the outer box mark can be used.

[0205] Next, in step S316, the wafer W11 (substrate to be measured) after development is taken out from the developing section by the C / D inner transfer system and is placed on the first substrate transfer section.

[0206] In the next step S318, the control device 60 of the measuring device 100 loads the wafer W11 (overlapping measurement target substrate) which has been developed and placed on the first substrate conveying unit onto the slider 10 in the above-mentioned order, and obtains the absolute position coordinates of each of the first mark image and the second mark image of the group I in the XY plane in the following manner. That is, 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 the first mark image and the second mark image of the group I on the wafer W11, and obtains the absolute position coordinates of each of the first mark image and the second mark image of the group I on the wafer W11 in the XY plane based on the detection results of each of the first mark image and the second mark image of the group I and the absolute position coordinates (X, Y) of the slider 10 when each mark image is detected. At this time, the control device 60 uses the Abbe errors of the first position measurement system 30 in the X-axis direction and the Y-axis direction and the measurement values of the second position measurement system 50 in the X-axis direction and the Y-axis direction as offsets based on the measurement values of the slide 10 in the θx direction and the θy direction measured by the first measurement system 30, and calculates the absolute position coordinates of each of the first marker image and the second marker image of group I in the XY plane.

[0207] In the next step S320, the control device 60 calculates the overlap error (overlap offset) between the first layer and the second layer based on the absolute position coordinates of the first marker image and the absolute position coordinates of the second marker image that are grouped together.

[0208] In the next step S322, the control device 60 determines whether the overlay error is mainly caused by the exposure of the first layer or the exposure of the second layer, based on the absolute position coordinates of the first marker image and the absolute position coordinates of the second marker image, for example, in the following manner. That is, the control device 60 obtains the offset (ΔX1 i, ΔY1 i) (i=1 to I) of the absolute position coordinates of the first marker image compared to the designed position coordinates, and the offset (ΔX2 i, ΔY2 i) (i=1 to I) of the absolute position coordinates of the second marker image compared to the designed position coordinates, and obtains the sum ΣX1 i, ΣX2 i, ΣY1 i, ΣY2 i of ΔX1 i, ΔX2 i, and ΔY1 i, ΔY2 i, i=1 to I for each of ΔX1 i, ΔX2 i. The control device 60 determines that the overlay error in either the X-axis direction or the Y-axis direction is mainly caused by the exposure of the first layer when ΣX1 i>ΣX2 i and ΣY1 i>ΣY2 i, and determines that the overlay error in either the X-axis direction or the Y-axis direction is mainly caused by the exposure of the second layer when ΣX1 i<ΣX2 i and ΣY1 i<ΣY2 i. Furthermore, the control device 60 determines that the overlay error in either the X-axis direction or the Y-axis direction is mainly caused by the exposure of the first layer and in the Y-axis direction is mainly caused by the exposure of the second layer when ΣX1 i>ΣX2 i and ΣY1 i<ΣY2 i, and determines that the overlay error in either the X-axis direction or the Y-axis direction is mainly caused by the exposure of the second layer when ΣX1 i<ΣX2 i and ΣY1 i>ΣY2 i is mainly caused by the exposure of the second layer and in the Y-axis direction is mainly caused by the exposure of the first layer.

[0209] Furthermore, the above judgment method is only an example. As long as the control device 60 judges whether the overlapping error is mainly caused by the exposure of the first layer or the exposure of the second layer based on the absolute position coordinates of I first mark images and the absolute position coordinates of I second mark images, the specific judgment method is not required.

[0210] From the above description, it can be seen that according to the overlap measurement method of this embodiment, the control device 60 of the measuring device 100 can respectively measure the absolute position coordinates of the first mark image and the absolute position coordinates of the second mark image. Based on these absolute position coordinates, it can be determined whether the overlap error is caused mainly by the exposure of the bottom layer or the exposure of the upper layer, thereby obtaining this kind of excellent effect that has not been achieved before.

[0211] Furthermore, although the above description is for a case where the exposure device used for bottom layer exposure is different from the exposure device used for upper layer exposure, it is not limited to this. For example, even when the bottom layer and the upper layer are exposed by the exposure device 200, the overlap accuracy can be managed with high precision through a series of processing of one of the above steps S302~S322.

[0212] Furthermore, in the above step S320, since the overlap error (overlap offset) between the first layer and the second layer has been calculated, step S322 only needs to be performed as needed.

[0213] In addition, in the lithography system 1000 of FIG. 8 , although only one measuring device 100 is provided, a plurality of measuring devices, for example, two measuring devices may be provided as in the following modified example.

[0214] 11 schematically shows the structure of a lithography system 2000 of a modified example. The lithography system 2000 includes an exposure device 200, a C / D 300, and two measuring devices 100a and 100b having the same structure as the aforementioned measuring device 100. The lithography system 2000 is installed in a clean room.

[0215] In the lithography system 2000 , two measuring devices 100 a and 100 b are arranged in parallel between the exposure device 200 and the C / D 300 .

[0216] The exposure device 200, C / D 300 and measuring devices 100a and 100b of the lithography system 2000 are arranged in a chamber adjacent to each other. The exposure control device 220 of the exposure device 200, the coating and development control device 320 of the C / D 300, and the control device 60 of the measuring devices 100a and 100b are connected to each other through a LAN 500 and communicate with each other. The memory device 400 is also connected to the LAN.

[0217] In the lithography system 2000 of this variation, since the same action sequence setting as the aforementioned lithography system 1000 can be performed, the same effect as the lithography system 1000 can be obtained.

[0218] In addition, in the lithography system 2000, both the measuring devices 100a and 100b can be used for alignment measurement of the wafer after PB (hereinafter referred to as post-measurement) and alignment measurement (pre-measurement) of the wafer before resist coating. In this case, the pre-measurement of a certain wafer is carried out in parallel with the aforementioned series of wafer processing of a different wafer, so that the overall system throughput is hardly reduced. However, for the first wafer, the time of pre-measurement cannot overlap with the time of a series of wafer processing.

[0219] By comparing the position of the same wafer mark on the same wafer measured by the pre-measurement and the position measured by the post-measurement, the position measurement error of the wafer mark caused by the resist coating can be obtained. Therefore, by correcting the position measurement error of the wafer mark caused by the resist coating for the position of the same wafer mark measured during the wafer alignment of the same wafer by the exposure device 200, a high-precision EGA measurement can be performed that offsets the position measurement error of the wafer mark caused by the resist coating.

[0220] In this case, regardless of whether it is pre-measurement or post-measurement, the measurement result of the position of the wafer mark will be affected by the holding state of the wafer holder. Therefore, for the same wafer, it is best to use the same measurement device 100a or 100b for both pre-measurement and post-measurement.

[0221] However, one of the measuring devices 100a and 100b may be used exclusively for pre-measurement, while the other may be used exclusively for post-measurement. In this case, when the measuring devices 100a and 100b are activated one by one, a reference wafer is mounted on each slider 10, and the position of the slider 10 is measured by the first position measuring system 30, while the mark on the reference wafer is detected by the mark detection system MDS, and based on the detection result, the grid of the reference wafer is obtained by each of the measuring devices 100a and 100b in the same manner as in the case of the aforementioned wafer W0. In this case, as the reference wafer, for example, a wafer having marks (line and space marks, two-dimensional grid marks, and box marks) that can be measured with resolution by the mark detection system MDS, formed on the entire surface by etching or the like at a specific pitch, for example, a pitch of 1 mm, may be used.

[0222] The coordinate systems of the first position measurement systems 30 are made consistent with each other to eliminate the differences between the grids of the reference wafers obtained. 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 reference wafers obtained, it should be because the reference coordinate systems used to define the movement of the sliders 10 of the measuring devices 100a and 100b have errors.

[0223] In this case, since the reference wafer is required for the calibration of the coordinate systems of the sliders of the specified measuring devices, the required scene is only when each measuring device is started. Compared with the conventional technology, the number of wafers and the frequency required are overwhelmingly reduced, and each measuring device only needs to measure the mark on the reference wafer, and there is no need to expose the reference wafer. In other words, since there is no need to apply or peel off the photoresist, there is no damage to the reference wafer. It is only necessary to carefully store the reference wafer as a standard. In addition, after each measuring device is started, the reference wafer is not required in principle.

[0224] In the lithography system 2000, the aforementioned overlay offset measurement can be performed on the wafer after development instead of the aforementioned pre-measurement. In this case, a given one of the measurement devices 100a and 100b can be used exclusively for the aforementioned post-measurement, and the other can be used exclusively for the overlay offset measurement. Alternatively, for the same wafer, the post-measurement and the overlay offset measurement can be performed in the same order by the same measurement device 100a or 100b. In the latter case, for the same wafer, the pre-measurement can be further performed by the same measurement device.

[0225] Although not shown in the figure, in the lithography system 2000, a predetermined one of the measuring devices 100a and 100b, for example, the measuring device 100a can be arranged on the opposite side of the C / D 300 from the exposure device 200. In this case, the measuring device 100a is suitable for performing the aforementioned overlay shift measurement of the wafer after development, if the process of wafer transfer is taken into consideration. In addition, if the individual difference in the holding state of the holders between the measuring devices 100a and 100b is not a problem, the measuring device 100a can be used for pre-measurement instead of overlay shift measurement, or can be used for overlay shift measurement and pre-measurement.

[0226] In addition, three or more measuring devices 100 may be provided in addition to the exposure device 200 and the C / D 300, and all the devices may be connected online, and two of the three measuring devices 100 may be used for pre-measurement and post-measurement, and the remaining one may be used exclusively for overlay offset measurement. Alternatively, the first two may be used exclusively for pre-measurement and post-measurement, respectively.

[0227] Furthermore, in the second embodiment and the modified example, the signal processing device 49 for processing the detection signal of the mark detection system MDS provided in the measuring devices 100, 100a, and 100b sends only the measurement results of the wafer marks whose detection signal waveforms are good as the detection results of the mark detection system MDS to the control device 60, and the control device 60 performs the EGA operation using the measurement results of the wafer marks, and the exposure control device 220 performs the EGA operation using part of the position information of the wafer marks selected from the plurality of wafer marks whose detection signal waveforms are good as the detection results of the mark detection system MDS. However, the present invention is not limited to this, and the signal processing device 49 may also send the measurement results of the remaining wafer marks after removing the wafer marks whose waveforms are bad from the detection signal obtained as the detection results of the mark detection system MDS to the control device 60. In addition, the control device 60 may be used to judge whether the detection signal obtained as the detection result of the mark detection system MDS is good or not, instead of the signal processing device. In this case, the control device 60 also performs the aforementioned EGA operation using only the wafer mark whose detection signal is judged to be good, or the measurement results of the remaining wafer marks after removing the wafer mark whose detection signal is judged to be bad. Furthermore, it is preferred that the exposure control device 220 performs the aforementioned EGA operation using the measurement results of a portion of the wafer marks selected from the measurement results of the wafer marks used for the EGA operation performed by the control device 60.

[0228] Furthermore, in the second embodiment and the modified example, although the measurement devices 100, 100a, 100b are arranged between the exposure device 200 and the C / D 300 instead of the online interface part, the measurement device (100, 100a, 100b) may be a part of the exposure device. For example, the measurement device may be set in the loading part of the exposure device 200 where the wafer before exposure is loaded. Furthermore, when the measurement device (100, 100a, 100b) is a part of the exposure device 200 and is arranged in the chamber of the exposure device 200, the measurement device may or may not be provided with a chamber. Furthermore, when the measurement device (100, 100a, 100b) is a part of the exposure device, the measurement device may be provided with a control device, or may not be provided with a control device and be controlled by the control device of the exposure device. In any case, the measurement device is connected to the exposure device.

[0229] Furthermore, in the above-mentioned embodiment, although the case where the substrate processing device is C / D is described, the substrate processing device can be any device as long as it is connected to the exposure device and the measuring device. It can be a coating device (coater) that coats a sensitive agent (resist) on a substrate (wafer), or a developing device (developer) that develops the substrate (wafer) after exposure, or it can be a coating device (coater) and a developing device (developer) that are respectively connected to the exposure device and the measuring device.

[0230] When the substrate processing device is a coater, the measuring device can be used only for the aforementioned post-measurement, or pre-measurement and post-measurement. In this case, the wafer after exposure is moved into a developing device that is not connected to the exposure device.

[0231] When the substrate processing device is a developer, the measuring device may be used only for the aforementioned post-measurement, or post-measurement and overlay offset measurement. In this case, a wafer pre-coated with a resist at another location is carried into the exposure device.

[0232] In the above second embodiment and modified examples (hereinafter referred to as the second embodiment, etc.), although the exposure device is described as a scanning stepper, it is not limited to this. The exposure device can be a static exposure device such as a stepper, or a reduced projection exposure device of a step & stitch method that synthesizes the irradiation area and the irradiation area. Furthermore, the above second embodiment, etc. can also be applied to a multi-stage exposure device with a plurality of wafer stages, such as disclosed in the specification of U.S. Patent No. 6,590,634, the specification of U.S. Patent No. 5,969,441, and the specification of U.S. Patent No. 6,208,407. In addition, the exposure device is not limited to the aforementioned dry exposure device that performs exposure of the wafer W without passing through liquid (water), and may also be, for example, a liquid immersion exposure device that exposes a substrate through liquid as described in European Patent Application Publication No. 1420298, International Publication No. 2004 / 055803, International Publication No. 2004 / 057590, U.S. Patent Application Publication No. 2006 / 0231206, U.S. Patent Application Publication No. 2005 / 0280791, U.S. Patent No. 6,952,253, etc. Furthermore, the exposure device is not limited to an exposure device for semiconductor manufacturing, and may also be, for example, a liquid crystal exposure device that transfers a liquid crystal display element pattern on a square glass plate.

[0233] In addition, the disclosures of all publications, international publications, U.S. patent application publication specifications, and U.S. patent specifications related to the exposure device cited in the above-mentioned embodiment are cited as part of the description of this specification.

[0234] Semiconductor components are manufactured by using an exposure device constituting the lithography system of the above-mentioned embodiment, through a lithography step of exposing a photosensitive object using a reticle (photomask) formed with a pattern and developing the exposed photosensitive object. In this case, high-integration components can be manufactured with a high yield.

[0235] In addition, the manufacturing process of semiconductor components may also include, in addition to the lithography steps, steps for designing the functions and performances of the components, steps for making reticle (mask) according to the design steps, component assembly steps (including cutting steps, bonding steps, packaging steps), inspection steps, etc.

[0236] 10: Slide 10a: concave part 12: Platform 14: Vibration isolation device 16: Base 18: Air bearing 20: Drive system 20A: 1st drive unit 20B: Second drive unit 22a, 22b: Movable 23a,23b: Movable 24: Movable stage 25a,25b: stator 26a,26b: stator 28A, 28B: X-axis linear motor 29A, 29B: Y-axis linear motor 30:1st position measurement system 32: Read the header 33: Encoder system 35: Laser interferometer system 35a~35d: Laser interferometer 37x:X Reader 37ya, 37yb:Y reader 40: Measurement unit 48: Vibration isolation device 50: Second position measurement system 52A, 52B: Read the header 58X 1, 58X 2: XZ reader 58Y 1, 58Y 2: YZ reader 60: Control device 100: Measuring device 100a, 100b: measuring device 200: Exposure device 300:C / D 330: Temperature Control Department 1000:Lithography System AX1: Optical axis MDS: Marker Detection System RG1: Grating RG2a, RG2b: Grating W: Wafer WH: Wafer Holder WST: Wafer Stage

Claims

1. A substrate processing system for processing a substrate having a plurality of zoned regions formed together with a plurality of marks, comprising: a measuring device having a first stage for holding the substrate and acquiring position information of the plurality of marks held on the substrate on the first stage; and an exposure device having a second stage for holding the substrate after the measuring device has acquired the position information of the plurality of marks, and performing an exposure operation to expose the plurality of zoned regions on the substrate placed on the second stage with an energy beam; the measuring device having a plurality of measuring modes corresponding to the position information acquired from a portion of substrates in a batch, selecting a measuring mode from the plurality of measuring modes to apply to the remaining substrates in the batch, and acquiring the position information of the plurality of marks on the remaining substrates according to the selected measuring mode; and the exposure device performing the exposure operation based on the position information acquired by the measuring device.

2. The substrate processing system as described in claim 1, wherein, One of the plurality of measurement modes includes an action of acquiring position information of a marker corresponding to each of the plurality of division regions formed on the substrate by means of the measurement device.

3. The substrate processing system as described in claim 1, wherein, One of the plurality of measurement modes includes the action of selecting a portion of the plurality of regions formed on the substrate, obtaining position information of a plurality of marks corresponding to the selected region by means of the measuring device, and obtaining position information of one mark corresponding to the unselected region by means of the measuring device.

4. The substrate processing system as described in claim 1, wherein, One of the plurality of measurement modes includes the action of acquiring position information of a plurality of marks corresponding to each of all the division areas on the substrate by means of the measuring device.

5. The substrate processing system as described in claim 1, wherein, One of the plurality of measurement modes includes, based on the obtained position information, determining, for the remaining substrate, a mark that should be used as the measurement object according to a plurality of marks corresponding to the plurality of division areas, and obtaining the position information of the mark by the measurement device.

6. The substrate processing system as described in claim 5, wherein, The location information obtained from the substrate of that part is the location information of a plurality of markers corresponding to all the division areas formed on the substrate of that part.

7. The substrate processing system as described in any of claims 3 to 5, wherein, Select from the plurality of marks corresponding to the zone area to calculate the shape information of the zone area.

8. The substrate processing system as described in claim 7, wherein, The shape information of the zone is calculated by statistically analyzing the location information of multiple markers within the zone.

9. The substrate processing system as described in claim 7, wherein, The exposure apparatus includes a detection device that acquires position information of a plurality of marks formed on the substrate held by the second stage; the exposure apparatus performs an exposure operation based on the shape information of each of the zoned areas and the position information of the plurality of marks measured using the detection device.

10. The substrate processing system as described in claim 9, wherein, The detection device acquires location information from a portion of the plurality of markers whose location information is measured by the measuring device.

11. The substrate processing system as described in claim 9, wherein, The exposure apparatus is a scanning exposure apparatus that enables a photomask stage capable of moving while holding a patterned photomask and a second stage to move synchronously relative to a projection optics system, thereby exposing the substrate with a projected image of the pattern; In the scanning exposure of one of the plurality of zone regions, at least one of the photomask stage and the second stage adjusts at least one of the following based on the shape information of the zone region: scanning angle, scanning speed, relative position, imaging characteristics of the projection optics system, and exposure wavelength.

12. The substrate processing system of claim 10, further comprising a substrate processing apparatus for performing a predetermined processing on the substrate.

13. The substrate processing system as described in claim 12, wherein, The substrate processing apparatus is a coating apparatus for applying a sensing agent onto a substrate.

14. The substrate processing system as described in claim 13, wherein, The measuring device is used for at least one of the following: a pre-measurement to measure the position information of a plurality of marks on the substrate before the coating of the inductor, and a post-measurement to measure the position information of the plurality of marks on the substrate after the coating of the inductor.

15. The substrate processing system as described in claim 14, wherein, The measuring device is provided in a plurality of units; the first measuring device and the second measuring device among the plurality of measuring devices are used for both pre-measurement of measuring the position information of the plurality of marks on the substrate before the coating of the inductive agent and post-measurement of measuring the position information of the plurality of marks on the substrate after the coating of the inductive agent. The first measuring device and the second measuring device are used for the pre-measurement and the post-measurement of the same substrate when the plurality of substrates are processed continuously.

16. The substrate processing system as described in claim 14, wherein, The measuring device is provided in a plurality of units; the second measuring device among the plurality of measuring devices is used for pre-measurement of the position information of the plurality of marks on the substrate before the coating of the inductive agent; the first measuring device among the plurality of measuring devices is used for post-measurement of the position information of the plurality of marks on the substrate after the coating of the inductive agent.

17. The substrate processing system as described in claim 12, wherein, The substrate processing apparatus is a coating and developing apparatus that coats a sensing agent onto a substrate and develops the substrate after exposure.

18. The substrate processing system of claim 17, wherein, This measuring device is capable of measuring the overlap offset of the overlap offset measurement marks on the substrate after the measurement and development process is completed.

19. The substrate processing system as described in claim 18, wherein, The measuring device is provided in a plurality of units; the first measuring device among the plurality of measuring devices is used for post-measurement of the position information of the plurality of marks on the substrate after the inductor is coated; the second measuring device among the plurality of measuring devices is used for measuring the overlap offset of the overlap offset measurement marks on the substrate after exposure by the exposure device and development by the substrate processing device.

20. The substrate processing system as claimed in claim 1, wherein, The measuring device acquires height distribution information of the substrate surface held on the first stage; the exposure device performs an exposure operation by means of an energy beam on the plurality of zoned areas on the substrate placed on the second stage, based on the height distribution information acquired by the measuring device.

21. The substrate processing system as described in claim 20, wherein, The measuring device includes a first detection system for detecting the mark formed on the substrate and a second detection system for detecting the surface height of the substrate; it obtains the position information of the mark based on the detection result of the first detection system and the position information of the first stage, and obtains the height distribution information of the substrate based on the detection result of the second detection system and the position information of the first stage.

22. The substrate processing system as claimed in claim 21, wherein, The second detection system is a multi-point position detection system capable of simultaneously detecting height information at multiple locations on the surface of the substrate.

23. The substrate processing system as described in claim 20, wherein, Before the exposure operation, the exposure device acquires the position information and height distribution information obtained by the measurement device.

24. The substrate processing system as described in claim 20, wherein, The exposure apparatus uses the position information and height distribution information obtained by the measuring device to control the position of the second stage during the exposure of the substrate.

25. The substrate processing system as claimed in claim 20, wherein, The exposure apparatus utilizes the height distribution information of the substrate surface obtained by the measuring device to control the position of the second stage during the exposure of the substrate in a direction orthogonal to the mounting surface of the second stage on which the substrate is mounted.

26. A substrate processing method, taking a substrate having a plurality of zoned regions formed together with a plurality of marks as the processing object, comprising: an operation of acquiring position information of a plurality of marks held on a substrate on a first stage capable of holding the substrate; and an exposure operation of transferring the substrate after acquiring the position information of the plurality of marks to a second stage different from the first stage, and exposing the plurality of zoned regions on the substrate placed on the second stage by an energy beam; the operation of acquiring the position information of the plurality of marks includes an operation of preparing a plurality of measurement modes, an operation of acquiring the position information from a portion of the substrates in a batch, an operation of selecting a measurement mode from the plurality of measurement modes to apply to the remaining substrates in the batch corresponding to the acquired position information, and an operation of acquiring the position information of the plurality of marks on the remaining substrates according to the selected measurement mode; the exposure operation is performed based on the position information.

27. The substrate processing method as described in claim 26, wherein, One of the plurality of measurement modes includes an action of acquiring position information of a marker corresponding to each of the plurality of regions formed on the substrate.

28. The substrate processing method as described in claim 26, wherein, One of the plurality of measurement modes includes the action of selecting a portion of the plurality of regions formed on the substrate, obtaining position information of a plurality of markers corresponding to each of the selected regions, and obtaining position information of one marker corresponding to the unselected regions.

29. The substrate processing method as described in claim 26, wherein, One of the plurality of measurement modes includes the action of acquiring position information of a plurality of marks corresponding to each of all the division areas on the substrate.

30. The substrate processing method as described in claim 26, wherein, One of the plurality of measurement modes includes, based on the obtained position information, determining, for the remaining substrate, a mark that should be used as the measurement object according to a plurality of marks corresponding to the plurality of division areas, and obtaining the position information of the mark.

31. The substrate processing method as described in claim 30, wherein, The location information obtained from the substrate of that part is the location information of a plurality of markers corresponding to all the division areas formed on the substrate of that part.

32. The substrate processing method of any one of claims 28 to 30, wherein, Select from the plurality of marks corresponding to the zone area to calculate the shape information of the zone area.

33. The substrate processing method as described in claim 32, wherein, The shape information of the zone is calculated by statistically analyzing the location information of multiple markers within the zone.

34. The substrate processing method as described in claim 32, wherein, The exposure operation is performed by synchronously moving the photomask stage holding the patterned photomask and the second stage relative to the projection optics system, thereby scanning and exposing the substrate with the projected image of the pattern. In the scanning exposure of one of the plurality of zoned regions, the relative scanning angle, scanning speed, position of the photomask stage and the second stage, and at least one of the imaging characteristics of the projection optics system and the exposure wavelength are adjusted according to the shape information of the zoned region.

35. The substrate processing method of claim 34 further includes: obtaining height distribution information of the surface of the substrate held on the first stage; and performing an exposure operation by an energy beam on the plurality of zoned areas on the substrate placed on the second stage, based on the height distribution information.

36. A method for manufacturing a component, comprising: processing a substrate using a substrate processing method as described in any one of claims 26 to 31; and assembling a component using the processed substrate.

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