WO2005008752A1

WO2005008752A1 - Exposure device, exposure method, and device manufacturing method

Info

Publication number: WO2005008752A1
Application number: PCT/JP2004/010472
Authority: WO
Inventors: Ayako Sukegawa
Original assignee: Nikon Corporation
Priority date: 2003-07-23
Filing date: 2004-07-23
Publication date: 2005-01-27
Also published as: JPWO2005008752A1; JP4251295B2

Abstract

Position shift amounts in the X direction and Y direction are detected between a transfer image of the mark formed by scan exposure under a low-speed scan condition and a transfer image of the mark formed by the scan exposure under a high-speed scan condition (steps 602 to 630). The reticle manufacturing error is removed from the position shift amount detected (step 632). Furthermore, a correction function is generated for correcting the measurement value of the interferometer measuring the wafer stage or the reticle stage according to the position shift amount from which the reticle manufacturing error is removed (step 634). When performing scan exposure in the actual process, the measurement value is corrected by the correction function generated and the stage control is performed according to the measurement value corrected.

Description

Specification

Exposure apparatus, exposure method, and device manufacturing method

Technical field

The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method. More specifically, a pattern formed on a mask and an object is synchronously moved with respect to illumination light by a projection optical system. The present invention relates to an exposure apparatus for performing scanning exposure for transferring onto an object by using the exposure apparatus, an exposure method using the exposure apparatus, and a device manufacturing method using the exposure method.

^ Scenic technology

In a lithographic process for manufacturing a semiconductor device, a liquid crystal display device, or the like, a pattern formed on a mask or a reticle (hereinafter, collectively referred to as a “reticle”) is coated with a resist or the like via a projection optical system. An exposure apparatus for transferring onto a substrate such as a wafer or a glass plate (hereinafter collectively referred to as a “wafer”), for example, a step-and-repeat type reduction projection exposure apparatus (a so-called stepper), Step-improved step-by-step projection exposure apparatus (hereinafter abbreviated as “exposure apparatus”) such as an 'and' scan type scanning projection exposure apparatus (so-called “scanning stepper”) is mainly used. RU

[0003] Particularly, in a scanning type exposure apparatus, exposure is performed by synchronously running a reticle (reticle stage) and a wafer (wafer stage) (ie, scanning exposure). The position control accuracy has a large effect on pattern transfer accuracy and overlay accuracy. For example, if the direction of movement of the reticle stage or wafer stage deviates from the running direction during synchronous operation, or if the reticle stage and the wafer stage are out of synchronization, the pattern transfer position will deviate from the desired position. Will be lost. Such a shift in the transfer position of the pattern directly appears in the exposure result as a shot distortion or a shift (that is, a normal / reverse difference) due to the scanning direction of the formation position of the shot area.

[0004] Therefore, conventionally, various techniques for improving the control accuracy of the wafer stage and the reticle stage during scanning exposure have been introduced. For example, correcting the measurement value of an interferometer that measures the position of both stages in consideration of the dynamic characteristics of synchronous scanning of both stages during scanning exposure is an example of such a technique. [0005] In the above technique, in order to correct the measurement value of the interferometer, it is necessary to accurately identify a model of a dynamic characteristic of synchronous scanning of both stages. However, the dynamic characteristics of synchronous scanning of both stages during scanning exposure are extremely complicated, and it is extremely difficult to accurately identify the dynamic characteristics.

[0006] In such an exposure apparatus, the dynamic characteristics of the synchronous scanning of the two stages differ from one apparatus to another. Therefore, the set values of the apparatus parameters that define the model of the dynamic characteristics can be adjusted for each apparatus. However, as described above, the model of the dynamic characteristics of an exposure apparatus is complicated, and the number of device parameters that define the dynamic characteristics becomes very large. It is very difficult to optimize due to 'and' errors. In addition, errors that cannot be seen by the interferometer and that are visible due to printing change due to differences in the dynamic characteristics of synchronous scanning, and parameter settings for correcting them are determined by trial and error. Is difficult,

Disclosure of the invention

Problems to be solved by the invention

The present invention has been made under vigorous circumstances, and a first object of the present invention is to provide an exposure apparatus capable of realizing high-precision exposure in a short time.

[0008] A second object of the present invention is to provide an exposure method capable of realizing highly accurate exposure in a short time.

[0009] A third object of the present invention is to provide a device manufacturing method capable of improving device productivity.

Means for solving the problem

[0010] According to a first aspect of the present invention, a pattern formed on a mask (R) and an object (W) is synchronously moved in a predetermined direction with respect to illumination light by a projection optical system (PL). An exposure apparatus (100) for performing scanning exposure for transferring onto the object through the scanning exposure, the plurality of marks arranged on the mask being subjected to a plurality of different scanning conditions by the scanning exposure. A transfer device (20) for transferring onto the body; a transfer device for transferring the plurality of marks by the scanning exposure under each of the scanning conditions, the transfer device being configured to transfer the mark on the object in a two-dimensional plane orthogonal to the optical axis of the projection optical system Acquisition device for acquiring information on the displacement of the transfer position of each mark. (20); based on the acquired information on the displacement of the transfer position of each mark and each of the scanning conditions, by using an optimization method, the scanning conditions and the two-dimensional plane A measurement of one of the position of the object and a position of the mask in a plane substantially parallel to the two-dimensional plane; A function creation device (20) for creating a correction function having a value correction amount as a dependent variable; when the transfer device performs scanning exposure to transfer the pattern onto an object under arbitrary scanning conditions. Then, the measurement value at one of the positions is corrected by using the correction function to which the arbitrary scanning condition is substituted, and based on the corrected measurement value, the position of one of the position and the deviation is determined. A control device (19) for controlling; a first exposure device comprising: A.

According to this, at least one mark formed on the mask by scanning exposure is transferred by the transfer device under a plurality of different running conditions, and the acquisition device transfers the mark from the reference position of the mark transfer position. The information about the deviation is obtained for each scanning condition. Then, based on each piece of information and each scanning condition obtained by the function creating device, the correction amount of the measurement value of one of the position of the object and the position of the mask in the two-dimensional plane is dependent on the optimization method. Create a correction function as a variable. Further, the measurement value of the position of the object is corrected by the control device, and the pattern is transferred onto the object by the transfer device while controlling the position of the object or the mask based on the corrected measurement value.

Therefore, according to the present invention, the measured value of the position of the object is corrected in consideration of the dynamic characteristic during the relative scanning between the mask and the object, using an optimization method that eliminates the try and error. Since it is possible to create a correction function used for the exposure, it is possible to realize high-precision exposure in a short time.

[0013] In this case, the control device may be configured to correct the plurality of running conditions based on the measured values of the one of the positions corrected using the correction function to which the respective running conditions are substituted. The transfer position of each mark acquired by the acquisition device as a result of performing the scanning exposure by the transfer device and transferring each mark onto the object while controlling one of the positions. Processing for correcting the correction function using the optimization technique based on the information on the positional deviation of the image and the respective scanning conditions. The apparatus may further include a function correction device that repeats until a predetermined condition is satisfied, and the control device may control one of the positions using a corrected correction function.

[0014] In this case, the predetermined condition may include a condition that a magnitude of a displacement of the transfer position of each mark is equal to or less than a predetermined amount.

[0015] In the first exposure apparatus of the present invention, the transfer apparatus performs the scanning exposure using an object in which a plurality of reference marks formed at positions corresponding to the marks on the mask are formed in advance. Then, the acquisition device may acquire a shift between the position of each of the reference marks and the transfer position of each of the marks as information on a position shift of the transfer position of each of the marks.

[0016] In the first exposure apparatus of the present invention, the transfer apparatus further transfers the plurality of marks onto the object by running exposure under predetermined running conditions. Information on the displacement of the transfer position of each mark due to the scanning exposure under each of the different scanning conditions with reference to the transfer position of each mark on the mask due to the scanning exposure under the predetermined scanning condition. Can be obtained.

[0017] In this case, the plurality of different scanning conditions include the same scanning condition as the predetermined scanning condition, and the acquisition device performs the scanning exposure under the different scanning condition. The amount of misalignment between the transfer position of each mark by light and the transfer position of each mark by scanning exposure under the predetermined scanning condition is determined by the scanning exposure under the same scanning condition. The amount obtained by subtracting the difference between the transfer position of each mark and the transfer position of each mark due to the scanning exposure under the predetermined scanning condition is acquired as information relating to the position shift of the transfer position of each mark. be able to.

[0018] In the first exposure apparatus of the present invention, the acquisition device may be configured to determine the plurality of marks based on a change between marks of a value of information on the displacement of the transfer positions of the plurality of marks. Part of the information on the displacement of the mark transfer position can be excluded or smoothed.

In this case, the value of the information about the displacement of the transfer position of the mark may be greater than the value of the information about the displacement of the transfer position of the surrounding mark by a predetermined degree or more. In this case, the information on the transfer position of the mark may be excluded from the information on the positional deviation of the transfer position of each mark, and the value of the information on the positional deviation of the transfer position may be removed. S, if there is a mark that protrudes by a predetermined degree or more with respect to the value of the information about the displacement of the transfer position of the surrounding mark, the value of the information about the displacement of the transfer position of the mark The value may be replaced with a value calculated by a predetermined interpolation calculation using information on the displacement of the transfer position of the mark.

[0020] In the first exposure apparatus according to the present invention, the acquisition apparatus may further include a position shift of the transfer position of each mark based on a statistic related to a position shift of each mark under the same scanning condition. Some of the information about may be excluded or smoothed.

[0021] In this case, the statistic is a variance of a value of information on a displacement of a transfer position of each of the marks under the same running condition, and the acquisition device is configured to obtain information on a displacement of the transfer position. If there is a mark whose value is outside the predetermined range based on the variance, the information on the displacement of the transfer position of the mark is obtained from the information on the displacement of the obtained transfer position of the mark. The statistic may be a variance of a value of information on a displacement of a transfer position of each mark under the same scanning condition, and the acquisition device may store information on a displacement of the transfer position. If there is a mark whose value is outside the predetermined range based on the variance, the value of the information on the displacement of the transfer position of the mark is determined in a plurality of scanning exposures under the same scanning condition. Each It is also good to substitute the average value of the information on the positional deviation of the acquired transfer position of the mark.

According to a second aspect of the present invention, a pattern formed on the mask is transferred onto the object via a projection optical system by synchronous scanning of the mask and the object in a predetermined direction with respect to illumination light. An exposure apparatus for performing scanning exposure, wherein the scanning exposure transfers a plurality of marks arranged on a mask onto an object under a plurality of different scanning conditions; An acquisition device for acquiring information on the synchronization accuracy between the mask and the object in the above; a running condition using an optimization technique based on the acquired information on the synchronization accuracy and each of the scanning conditions; Of the object in the two-dimensional plane At least one of a position and a measured value at one of the positions of the mask in a plane substantially parallel to the two-dimensional plane is a first term, and the measured value at one of the positions is at least one of the first and second terms. A function creation device for creating a correction function having a correction amount as a dependent variable; and the transfer device performs scan exposure under an arbitrary scan condition to transfer the pattern onto an object. Using the correction function to which the scanning condition is substituted, the measurement value at one of the position and the deviation is corrected, and based on the corrected measurement value, the position of the one of the deviation and the deviation is controlled. And a control device.

According to this, at least one mark formed on the mask by the scanning exposure is transferred by the transfer device under a plurality of different scanning conditions, and the mask and the object during the scanning exposure are transferred by the acquisition device. The information on the synchronization accuracy with is acquired for each scanning condition. Then, based on each information and each scanning condition acquired by the function creation device, a correction function for making a dependent variable the correction amount of the measured value of the position of the object in the two-dimensional plane using an optimization method. create. Further, the control device corrects the measured value of one of the position of the object and the mask, and controls the position of the object or the mask based on the corrected measured value, and transfers the pattern on the object by the transfer device. Transfer to

Therefore, according to the present invention, it is possible to use an optimization method that eliminates a try and error to correct the measured value of the position of an object so as to minimize the synchronization accuracy between the mask and the object. Since any correction function can be created, high-precision exposure can be realized in a short time.

[0025] In this case, the control device converts the measured value of one of the position and the position corrected using the correction function into which the respective scanning conditions are substituted under the plurality of different scanning conditions. The transfer device performs the scanning exposure to transfer each of the marks onto the object in a state where the one of the positions is controlled, and the mask obtained by the obtaining device. A function correction device that repeats a process of correcting the correction function using the optimization method based on information on synchronization accuracy with the object and the respective scanning conditions until a predetermined condition is satisfied. And the control device may use a corrected correction function.

[0026] In the second exposure apparatus of the present invention, the transfer apparatus performs the scanning exposure during the scanning exposure. The moving time average of the synchronization accuracy between the mask and the object can be acquired as information on the synchronization accuracy.

In the second exposure apparatus of the present invention, the information on the synchronization accuracy may include an error in synchronous scanning between the mask and the object.

[0028] In the second exposure apparatus of the present invention, the acquisition apparatus is configured to acquire the synchronization acquired based on statistics of information on synchronization accuracy corresponding to a plurality of sampling times during the scanning exposure. Some of the information on accuracy may be excluded or smoothed out.

[0029] In this case, the statistic is a variance of a value of information on synchronization accuracy at each of the sampling times under the same running condition, and the acquisition device determines a value outside a predetermined range based on the variance. Information on the synchronization accuracy at a certain sampling time may be excluded from the acquired information on the synchronization accuracy, and the statistic may be a value of the information on the synchronization accuracy at each sampling time under the same scanning condition. Wherein the acquisition device obtains a synchronization value at the same sampling point obtained in a plurality of scanning exposures under the same scanning condition. It may be replaced with the average value of the information on the accuracy.

In the first and second exposure apparatuses of the present invention, the first term may be a power function in which a measured value of the position of the object is an independent variable.

In the first and second exposure apparatuses according to the present invention, the scanning condition may include at least one of a scan length and a scan speed.

In the first and second exposure apparatuses of the present invention, the scanning condition can include a scanning direction.

[0033] In the first and second exposure apparatuses of the present invention, the correction function may further include a second term in which time during the scanning exposure is an independent variable.

[0034] In this case, the second term may be at least one of a sine function and a power function that uses the measured value of the position of the object as an independent variable.

[0035] In the first and second exposure apparatuses of the present invention, the correction function includes a correction function using a correction amount of a measured value of the position of the object in the scanning direction as an objective function, and the two-dimensional plane. And a correction function that uses the correction amount of the measured value of the position of the object in a direction orthogonal to the scanning direction as an objective function, and a correction function that uses the correction amount of the position of the object in the scanning direction as an objective function. May further include a third term including a linear function having a measured value of the position of the object in the scanning direction as an independent variable.

In the first and second exposure apparatuses of the present invention, the optimization method may be a least-squares method, or the optimization method may be a non-linear least-squares method. good.

According to a third aspect of the present invention, a pattern formed on the mask is transferred onto the object via a projection optical system by synchronously scanning the mask and the object in a predetermined direction with respect to illumination light. An exposure method for performing scanning exposure, which includes performing scanning exposure using the first and second exposure apparatuses of the present invention, and transferring a pattern on the mask to the object. In the case of high power, scanning exposure is performed using the first and second exposure apparatuses of the present invention, so that high-precision exposure can be realized in a short time.

According to a fourth aspect of the present invention, in a device manufacturing method including a lithographic process, in the lithographic process, exposure can be performed using the exposure method of the present invention. In the case of power, since exposure is performed using the exposure method of the present invention, high-precision exposure can be realized in a short time, so that the productivity of a highly integrated device can be improved. it can.

Brief Description of Drawings

FIG. 1 is a view showing a schematic configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a measurement reticle used for low-speed / high-speed overlapping.

FIG. 3 is a diagram showing an example of a mark formed on a measurement reticle.

FIG. 4 (A) is a view schematically showing an exposure result on wafer W when low-speed and high-speed superimposed scanning exposure is performed.

FIG. 4 (B) is an enlarged view of a transfer result of each mark M in low-speed and high-speed scanning exposure.

P

The

FIG. 4 (C) is an enlarged view of an L / S pattern image formed by low-speed / high-speed overlapping.

FIG. 5 is a flowchart (part 1) illustrating an exposure method according to an embodiment of the present invention. FIG. 6 is a flowchart (part 2) showing an exposure method according to one embodiment of the present invention.

FIG. 7 is a flowchart (part 3) showing an exposure method in one embodiment of the present invention.

FIG. 8 is a diagram showing an example of a pattern image formed on a wafer.

FIG. 9 (A) is a view schematically showing an actual result of exposure on a wafer W in the case where low-speed and high-speed overlapping scanning exposure is actually performed.

[Fig. 9 (B)] The actual transfer result of each mark M in the low-speed and high-speed overlapping scanning exposure is enlarged.

P

FIG.

FIG. 9 (C) is an enlarged view of an actual L / S pattern image formed by low-speed high-speed overlapping

FIG. 10 (A) is a view schematically showing a shot area formed by scanning exposure in a plus scan.

FIG. 10 (B) is a view schematically showing a shot area formed by scanning exposure in a minus scan.

FIG. 11 is a flowchart showing an example of a process for realizing a method of removing an error classified as Α.

FIG. 12 is a flowchart showing an example of a process for realizing a method of removing an error classified as a category.

FIG. 13 is a flowchart illustrating an embodiment of a device manufacturing method according to the present invention.

FIG. 14 is a flowchart showing details of step 804 in FIG. 13.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a schematic configuration of an exposure apparatus 100 according to one embodiment to which the exposure method of the present invention is applied. The exposure apparatus 100 is a step-and-scan type projection exposure apparatus. The exposure apparatus 100 includes an illumination system 10, a reticle stage RST on which a reticle R as a mask is mounted, a projection optical system PL, a wafer stage WST on which a wafer W as an object is mounted, an alignment detection system AS, and the entire apparatus. It is equipped with a main control device 20, etc., that controls the entire system. [0042] The illumination system 10 includes, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-313250 and the corresponding US Patent Application Publication No. 2003/0025890, etc. The system includes an optical system, a relay lens, a variable ND filter, a variable field stop (also called a reticle blind or a masking blade), and a dichroic mirror (the displacement is not shown). As an optical 'integrator, a fly-eye lens, a rod integrator (internal reflection type integrator), a diffractive optical element, or the like is used.

In the illumination system 10, on a reticle R on which a circuit pattern or the like is drawn, a slit-shaped illumination area (a rectangular illumination area elongated in the X-axis direction) defined by a reticle blind is irradiated with illumination light ( Exposure light) Illuminate with almost uniform illuminance by IL. Here, as the illumination light IL, far ultraviolet light such as KrF excimer laser light (wavelength 248 nm) or ArF excimer laser light (wavelength 193 nm) or vacuum ultraviolet light such as F laser light (wavelength 157 nm) is used. Lighting

2

It is also possible to use an ultraviolet bright line (g-line, i-line, etc.) from an ultra-high pressure mercury lamp as the light IL.

A reticle R force S, for example, is fixed on the reticle stage RST by vacuum suction. The reticle stage RST is driven by a reticle stage drive unit (not shown) driven by a linear motor, a voice coil motor, or the like, and has a XY axis perpendicular to the optical axis of the illumination system 10 (which coincides with the optical axis AX of the projection optical system PL described later). In addition to being capable of micro-driving in a plane, it can be driven at a set scanning speed in a predetermined direction (here, the Y-axis direction, which is the horizontal direction in the plane of FIG. 1).

[0045] The reticle stage RST has a reflecting surface formed of a moving mirror or the like facing the X-axis direction and the Y-axis direction that reflects the laser light. The position of the reticle stage RST in the stage moving plane is A reticle laser interferometer (hereinafter, referred to as a “reticle interferometer”) 16 that irradiates a reflecting surface with laser light is constantly measured with a resolution of, for example, about 0.5 to lnm. Here, actually, a reticle X interferometer and a reticle Y interferometer are provided. In FIG. 1, these are typically shown as a reticle interferometer 16. At least one of the reticle Y interferometer and the reticle X interferometer, for example, the reticle Y interferometer is a two-axis interferometer having two measurement axes, and the reticle is determined based on the measurement value of the reticle Y interferometer. In addition to the Y position of the stage RST, the rotation amount (jowing amount) in the θζ direction (rotation direction around the Ζ axis) can be measured. Here, the reticle-interferometer is a two-axis interferometer. Position information of the reticle stage RST (including rotation information such as the amount of jogging) from the reticle interferometer 16 is supplied to the stage controller 19 and the main controller 20 via the stage controller 19. The stage control device 19 drives and controls the reticle stage RST via a reticle stage driving unit (not shown) based on the position information of the reticle stage RST in accordance with an instruction from the main control device 20. Controls the position of reticle R held. Note that the stage control device 19 has a function of correcting the measurement value of the position of the reticle stage RST measured by the reticle interferometer 16 using a correction function. During scanning exposure, whether or not to perform correction using this correction function is determined by an instruction from the main control device 20, and a correction function such as a coefficient of each term of the correction function is used. Can be set from the main control device 20 to the stage control device 19 as device parameters.

Above the reticle R, a pair of reticle alignment detection systems 22 (however, the reticle alignment detection system 22 on the back side of the paper is not shown in FIG. 1) is arranged at a predetermined distance in the X-axis direction. ing. Each reticle alignment detection system 22 includes an epi-illumination system for illuminating a mark to be detected with illumination light having the same wavelength as the exposure light IL, and an illumination system for illuminating the mark to be detected. And a detection system for capturing an image. The detection system includes an imaging optical system and an image sensor, and the imaging result of this detection system (that is, the detection result of the mark by the reticle alignment detection system 22) is supplied to the main control device 20. In this case, a mirror (not shown) for guiding the emitted illumination light onto the reticle R and guiding the detection light generated from the reticle R by the illumination to the detection system of the reticle alignment detection system 22 in this case. Mirror is placed on the optical path of the exposure light IL so that it can be removed. When the exposure sequence is started, before the irradiation of the exposure light IL for transferring the pattern on the reticle onto the substrate, The reflecting mirror is retracted out of the optical path of the exposure light IL by a driving device (not shown) based on a command from the main controller 20.

The projection optical system PL is arranged below the reticle stage RST in FIG. The direction of the optical axis AX is defined as the Z-axis direction. As the projection optical system PL, a refraction exp

Optical systems are used. For this reason, when the illumination area IL of the reticle scale is illuminated by the illumination light IL from the illumination system 10, a reduced image (partially inverted image) of the illumination area of the circuit pattern of the reticle R is formed on the wafer via the projection optical system PL. The light is projected onto a projection area in the field of view of the projection optical system conjugate to the illumination area on W, and is transferred to a resist layer on the surface of the wafer W.

[0048] The wafer stage WST is disposed on a base (not shown) below the projection optical system PL in Fig. 1. Wafer holder 25 is mounted on wafer stage WST. The wafer W is fixed on the wafer holder 25 by, for example, vacuum suction or the like.

The wafer stage WST is driven by the wafer stage drive unit 24 in FIG. 1 to have X, Υ, Ζ, θ ζ (rotation direction around the 軸 axis), θ χ (rotation direction around the Χ axis), and 0 y ( This is a single stage that can be driven in six degrees of freedom (rotation direction around the Y axis).

[0050] The wafer stage WST is provided with a reflecting surface such as a moving mirror or the like facing the X-axis direction and the Y-axis direction that reflects the laser light, and the position of the wafer stage WST is set at the reflecting surface. For example, a wafer laser interferometer (hereinafter, referred to as a “wafer interferometer”) 18 irradiating laser light is always measured with a resolution of about 0.5 to lnm. Actually, a force provided with an interferometer having a length measuring axis in the X-axis direction and an interferometer having a length measuring axis in the Y-axis direction is typically shown as a wafer interferometer 18 in FIG. Have been. These interferometers are composed of multi-axis interferometers having multiple measuring axes. In addition to the X and Y positions of the wafer stage WST, rotation (Z rotation, which is rotation around the Z axis), pitching (Rotation around the X-axis, θX rotation), and rolling (rotation around the Y-axis, Θy rotation)). The stage control device 19 drives and controls the wafer stage WST via the wafer stage drive unit 24 based on the position information of the wafer stage WST in accordance with an instruction from the main control device 20, and places it on the wafer stage WST. Controls the position of wafer W held.

[0051] A reference mark plate FM is fixed near wafer W on wafer stage WST. The surface of this reference mark plate FM is set at almost the same height as the surface of the wafer W. On this surface, at least a pair of reference marks for reticle alignment, a reference mark for baseline measurement of the alignment detection system AS, and the like are formed.

[0052] The alignment detection system AS is an off-axis type alignment sensor arranged on the side surface of the projection optical system PL. The alignment detection system AS, for example, irradiates the target mark with a broadband detection light beam that does not expose the resist on the wafer, and reflects the target mark image formed on the light receiving surface by the reflected light from the target mark. An image processing method FIA (Field Image) that captures an image of an index (an index pattern on an index plate provided in the alignment detection system AS) using an image sensor (CCD) and outputs an image signal of the image. Alignment) type sensors are used. Note that the alignment sensor of the alignment detection system AS is not limited to the FIA system, but irradiates a target mark with coherent detection light and detects scattered light or diffracted light generated from the target mark, or detects the target mark. It is of course possible to use an alignment sensor that detects two interferences (for example, diffraction light of the same order or diffraction light diffracted in the same direction) generated from the laser beam, alone or in appropriate combination. . The imaging result of the alignment detection system AS is output to the main controller 20.

The control system is mainly configured by a main controller 20 and a stage controller 19 under the main controller 20 in FIG. The main controller 20 includes a so-called microcomputer (or workstation) including a CPU (central processing unit), a main memory, and the like, and controls the entire apparatus.

The main controller 20 includes, for example, a storage device including a hard disk, an input device including a pointing device such as a keyboard and a mouse, and a display device such as a CRT display (or a liquid crystal display). (Not shown), and a drive device (not shown) for information recording media such as CD (compact disc), DVD (digital versatile disc), MO (magneto-optical disc), and FD (flexible disc). Connected with. An information recording medium (hereinafter, referred to as a CD) set in the drive device includes a program (hereinafter referred to as a “specific program” for convenience) corresponding to a processing algorithm in a measurement operation and an exposure operation shown in a flowchart described later. ), Other programs, and databases attached to these programs. [0055] Main controller 20 executes a process according to the above-mentioned specific program so that, for example, the exposure operation is properly performed. For example, when performing the scanning exposure, the operation is instructed to the stage control device 19 and information necessary for the operation is transmitted to the stage control device 19. The stage controller 19 includes a position-speed feedback control system as a feedback control system for controlling the position and speed of the reticle stage RST, and a feedback control system for controlling the position and speed of the wafer stage WST. All position-speed feedback control systems have been constructed. Upon receiving the instruction and the information, the stage controller 19 creates a position command per unit time to the position-one-speed feedback control system of both stages based on the information. Then, the drive amount of the reticle stage RST and the wafer stage WST corresponding to the position command is calculated. According to the calculated driving amount, the stage control device 19 performs, for example, synchronous scanning of the reticle R and the wafer W during scanning exposure and movement of the wafer W via the reticle stage driving unit and the wafer stage driving unit 24. (Stepping) and so on. In order to realize synchronous scanning of both stages, one of the position / velocity feedback control systems of the two stages may be in a main relationship and the other may be in a subordinate relationship. For example, a position command for the control system of wafer stage WST may be generated based on the feedback control amount of the control system of reticle stage RST, and the position command may be generated, or vice versa.

More specifically, the stage control device 19 sets, for example, at the time of scanning exposure, in the + Y direction or the Y direction based on the set scanning direction via the reticle R force S reticle stage RST. In synchronization with the scanning at the set scanning speed, the wafer W is moved via the wafer stage WST with respect to the projection area conjugate to the illumination area in the direction opposite to the moving direction of the reticle stage RST (scanning direction). ) At a speed of 3 (= 1 / M) times the speed of reticle R (13 is a projection magnification from reticle R to wafer W, for example, 1/4 or 1Z5). Create a position command value for the feedback control system. When the position command value is input to the feedback control system described above, the feedback control system calculates a deviation between the position command value and the feedback amount based on the measurement values of the reticle interferometer 16 and the wafer interferometer 18. Not shown so that the deviation is canceled The position and speed of reticle stage RST and wafer stage WST are controlled via reticle stage drive unit and wafer stage drive unit 24, respectively.

At the time of stepping, the stage control device 19 creates a position command value at the time of step movement based on the set step speed, and inputs the created position command value to the feedback control system. Then, in the feedback control system, the position of wafer stage WST is controlled via wafer stage drive unit 24 based on the deviation between the command value and the feedback amount based on the measured value of wafer interferometer 18. Hereinafter, the case where wafer stage WST is scanned in the + Y direction is referred to as “plus scan”, and the case where wafer stage WST is scanned in the −Y direction is referred to as “minus scan”.

Further, the exposure apparatus 100 of the present embodiment provides an image forming light beam for forming a plurality of slit images toward the best image forming plane of the projection optical system PL from an oblique direction with respect to the optical axis AX direction. An oblique incidence multi-point focus detection system, which includes an irradiation system (not shown) to supply and a light receiving system (not shown) that receives each reflected light beam of the imaging light beam from the surface of the wafer W through a slit, respectively. System. As the multi-point focus detection system, for example, one having the same configuration as that disclosed in Japanese Patent Application Laid-Open No. 6-283403 and U.S. Patent No. 5,448,332 corresponding thereto is used. The output of the multipoint focus detection system is supplied to main controller 20. The stage controller 19 sends the wafer stage WST to the Z stage via the stage controller 19 and the wafer stage driver 24 based on the wafer position information from the multipoint focus detection system in accordance with an instruction from the main controller 20. Drive in the direction and tilt direction.

Next, the exposure method of the present embodiment will be described. In the exposure apparatus 100, as described above, the reticle stage RST (reticle R) and the wafer stage WST (wafer W) are synchronously moved in the Y-axis direction to transfer the pattern on the reticle R onto the wafer W. I do. In such scanning exposure, the transfer accuracy of the pattern on the reticle R greatly depends on the dynamic characteristics of the synchronous scanning of the reticle stage RST and the wafer stage WST during relative scanning. For example, based on the measurement values of the wafer interferometer 18, the relative positional relationship between the two stages RST and WST gradually shifts in the X-axis direction during the relative movement of the two stages RST and WST in the Y-axis direction. If it has dynamic characteristics, it is transferred onto the wafer W The pattern image is distorted with respect to the pattern on the reticle R. Such distortion appears as an exposure result as a shot distortion component in the shot area or a shift in the formation position of the shot area due to the scan direction (hereinafter, the shift accompanying the scan direction is referred to as “forward / reverse difference”). .

In order to cope with such a problem of distortion, the exposure apparatus 100 of the present embodiment corrects a measurement value of the reticle interferometer 16 during scanning exposure. For example, if the reticle stage RST is shifted in the + Χ direction during the synchronous movement in the Y-axis direction, the reticle stage RST can be controlled by correcting the measurement value of the X interferometer of the reticle interferometer 16 in the + Χ direction. The feedback control system of the stage controller 19 drives the reticle stage RST to the opposite side (-(side). As a result, the reticle stage RST does not shift to the + Χ side and the 、 axis direction To move accurately.

Therefore, in the present embodiment, before performing the actual scanning exposure, a predetermined reticle (a measurement reticle R described later) is loaded on the reticle stage RST instead of the reticle R in FIG.

Τ

Scan exposure is performed, and the exposure result (printing result) transferred onto the wafer is measured by the scanning exposure to detect a shot distortion component and the like in the shot area. Based on the detected shot distortion component and the like, Then, a correction function that gives an appropriate correction amount to the measurement value of the reticle interferometer 16 or the wafer interferometer 18 during the scanning exposure is created, and the measurement function of the reticle interferometer 16 is used during the scanning exposure using the correction function. The value shall be corrected.

Usually, in exposure apparatus 100, the pattern of the reticle mounted on reticle stage RST is various, and the size of the pattern region in which the pattern is formed also differs depending on the reticle. That is, in the exposure apparatus 100, the moving distance (scan length) of the relative scanning between the two stages RST and WST during scanning exposure changes depending on the circuit pattern to be formed on the wafer W. In the exposure apparatus 100, the relative speed (scan speed) of both stages, the moving speed (step speed) in stepping movement before running exposure, and the like may be different depending on the process (exposure process). Therefore, the correction function for correcting the measurement value of the reticle interferometer 16 created by the exposure method of the present embodiment is not limited to any of the scan conditions such as scan length, scan speed, and step speed. Also apply Desirable functions are desirable. Therefore, in the present embodiment, scanning exposure is performed under a plurality of different scan lengths, scan speeds, and the like, that is, under a plurality of different scanning conditions, and based on an exposure result under each scanning condition, an arbitrary scanning condition is set. It is assumed that a correction function that can be applied to is created.

[0063] Table 1 below shows an example of running conditions set at the time of running exposure trial.

[Table 1]

Table 1 above has two columns, low speed (fast) and high speed (second). These two columns have three items, scan length, scan speed, and step speed. Listed as conditions. The high-speed (second) column is divided into condition 0 to condition 9 items.

In the present embodiment, first, scanning exposure is performed at a very low scan speed that is not employed in a normal process. The running conditions in the running exposure (hereinafter referred to as “low-speed running conditions” or “standard running conditions”) are described in the low-speed (fast) column of Table 1. That is, the scan length, scan speed, and step speed described in the low-speed (first) column indicate the respective set values when performing the low-speed scanning exposure. Speed and step speed They are set to 33mm, 30mm / s and 30mm / s respectively. Under these low-speed running conditions, scanning exposure is performed while both stages are kept almost completely synchronized by the position-one-speed control by the feedback control system of both stages. Can be regarded as an exposure result which is hardly affected by the dynamic characteristics of the synchronous scanning of the reticle stage RST and the wafer stage WST. Therefore, in the present embodiment, as described later, the exposure result (the exposure result when the above-described “reference scanning condition” is used) is used as the “reference exposure result”.

Further, in the present embodiment, after the running exposure is performed under the low-speed running conditions, the running is performed at a relatively high scanning speed that is used in the normal running exposure. Perform exposure. In the high-speed (second) column of Table 1, the scan length, scan speed, and step speed under a plurality of different running conditions, that is, condition 0 to condition 9 (hereinafter abbreviated as “high-speed running conditions”) are shown. Are set, respectively. As can be seen from Table 1, in the present embodiment, the scan length (33 mm, 25 mm, 17 mm), scan speed (30 mmZs, 170 mm / s, 240 mm / s, 300 mm / s), step speed (30 mm / s, 495 mm / s) Combined force of scan length, scan speed, and step speed obtained by selecting one set value from each set value of each set value in conditions 1 to 9 in high-speed scan conditions ing. The condition 0 (*) is the same as the low-speed scanning condition.

As described above, in the present embodiment, as a plurality of different scanning conditions, for example, under the scanning conditions from condition 0 to condition 9 shown in Table 1 (hereinafter, abbreviated as “high-speed scanning condition”). In this way, scanning exposure is performed, and the same pattern as the pattern transferred on the wafer selected by scanning exposure under low-speed scanning conditions is transferred so as to be superimposed on the wafer, so-called "low speed-high speed". Overlay "exposure (hereinafter, abbreviated as" low speed-high speed overlap ") is performed. Note that the exposure amount (dose) when performing a running exposure under “low-speed (reference) running conditions” and the exposure amount (dosing) when performing a running exposure under “high-speed running conditions” The main controller 20 controls the exposure amount for each running condition so that the exposure amount is the same as the exposure amount (predetermined exposure amount).

Next, an example of the measurement reticle used for the above-described low-speed / high-speed overlapping will be described. To do.

FIG. 2 shows an example of a measurement reticle R used in low-speed / high-speed overlapping.

T

. FIG. 2 shows the reticle R for measurement as viewed from the pattern surface side (the lower surface side in FIG. 1).

T

It is a top view.

In this measurement reticle R, one surface (pattern surface) of the square glass substrate 42 is

T

A pattern area PA, which is a light-shielding band indicated by, is formed, and is arranged in a matrix at a predetermined mark M force and a predetermined interval in the pattern area PA. In Figure 2,

P

A predetermined mark M force 3 rows and 5 columns (rows in the Y-axis direction) are shown only in a total of 15 (M-M) in Figure p 1 15. Formed in PA. As shown in Table 1 above, under high-speed running conditions, since the scan length is set within the range of 17 mm and 33 mm, the distance between the marks M at both ends in the Y-axis direction on the pattern area PA (mark) The distance between M, M, M and the mark M, M, M) is 33mm XM p 1 6 11 5 10 15

17 exp in the Y-axis direction with respect to the center of the pattern area PA.

exp p needs to have a sufficient number of marks M within the range of mm X M to calculate the correction function.

In the low-speed and high-speed scanning exposure according to the present embodiment, scanning exposure is performed under low-speed scanning conditions using the measurement reticle R shown in FIG. 2, and the wafer stage WST is driven.

T

The position of the wafer (actually, the wafer for measurement w described later) in the X and γ directions.

T

The scanning exposure is performed again under a high-speed scanning condition (for example, any one of the conditions 0 to 9 in Table 1) while being shifted by a predetermined distance L.

FIG. 3 shows an example of the predetermined mark M. As shown in Figure 3, mark M

P P

L / S pattern MX and MX extending in the X-axis direction and L / S pattern extending in the Y-axis direction

1 2

MY and MY are formed. In Fig. 3, the chrome part of mark M is oblique.

1 2 p

The light transmission part is shown by a solid line. As shown in Fig. 3, in the LZS patterns MX, MX, MY, and MY, the lines serve as light transmission parts,

1 2 1 2

Part. The LZS pattern MX and MY have three lines at both ends in the array direction.

1 1

A pattern is formed and L / S patterns MX and MY can be included near the center.

twenty two

A pattern having a space (chrome portion) having a region is formed. L / S pattern MX and MY are the L / S patterns MX and MY, respectively, and the reticle R on the X axis.

1 1 2 2 T

It is provided at a distance of M XL in the direction and the Y-axis direction. This is because the scanning exposure is performed by shifting the position of the wafer in the X direction and the 距離 direction by a predetermined distance L as described above.

FIG. 4 (A) shows the exposure result on wafer W when low-speed and high-speed overlapping scanning exposure was performed.

Τ

Is schematically shown. A negative photoresist is applied on the wafer w.

Shall be. As shown in FIG. 4 (A), each mark formed on the reticle R is obtained by shifting the wafer stage WST by L in the X direction and the X direction and performing low-speed and high-speed scanning exposure. The superimposed image MP of MP is represented by L (

T P P

It is shifted by 1 / M times on the reticle R by the projection magnification / 3)

T exp

Transfer formation.

[0074] Fig. 4 (B) shows an enlarged transfer result of each mark M in low-speed and high-speed scanning exposure.

P

Shown. As shown in FIG. 4 (B), as a result of the overlapping scanning exposure, the L / S pattern MX and the L / S pattern MX are transferred so as to overlap, and the L / S pattern MY and

1 2 1

, And L / S pattern MY are transferred so as to overlap. Note that the wafer W

2 T is actually exposed on the wafer W because the negative type photoresist is applied,

T

What remains after development is the line pattern of each L / S pattern MX, MX, MY, MY.

1 2 1 2

It is only the part to be copied. As a result, as shown in FIG. 4 (B), the L / S pattern MX

1 The L / S pattern image MXP is formed by the image and the L / S pattern MX image, and the L / S pattern

2 P

The MY image and the L / S pattern MY image form the L / S pattern image MYP.

1 2 p

FIG. 4 (C) shows an enlarged L / S pattern image MXP force. As shown in Fig. 4 (C)

P

As shown, in the low-speed and high-speed superimposed scanning exposure,

P

The center of the image MX, of the L / S pattern MX and the center of the image MX, of the L / S pattern MX

1 1 2 2 The L / S pattern image MX,

1

The distance between the center and the center of the L / S pattern image MX is a predetermined distance Ll, L2, respectively.

2

The Note that the distance between the L / S pattern MY and the L / S pattern MY is

1 2

As with the relationship between the S pattern MX and the LZS pattern MX, the center of

1 2 It is assumed that the positional relationship between the images of the respective patterns when they are matched and superimposed is known.

In FIG. 4C, the L / S pattern image MX ′ and the L / S pattern image MX ′ are integrated.

1 2

The force shown is as if a LZS pattern with a duty ratio of 50% is formed. Rather, the center of the L / S pattern MX image MX 'and the LZS pattern MX image

1 1 2

Even if the center of MX is slightly deviated, the line pattern image of L / S pattern MX

2

Of the LZS pattern MX so that the line pattern image of the L / S pattern MX does not overlap

It is desirable to make the central chrome part wide enough. This is because the LZS pattern MX and L / S pattern MX formed on the measurement reticle R

Τ 1 2 is transferred so as to be superimposed as shown in FIG. 4 (C), and in the transfer result of the superimposition, the image MX of the L / S pattern MX and the image MX ′ of the LZS pattern MX are obtained. The two

It is necessary to detect the distance force from each of the line patterns L1 and L2, and to accurately calculate the deviation, each line pattern is placed on the wafer W.

T

This is because it must be completely reproduced.

Returning to FIG. 2, the center of pattern area PA, that is, the center of reticle R (reticle center) τ

A pair of reticle alignment marks R Ml, RM2 are formed on both sides in the X-axis direction of the pattern area PA passing through. Note that FIG. 2 shows only one pair of the reticle alignment marks RM 1 and RM 2, but actually, a plurality of pairs are provided along the Y-axis direction.

Next, the operation of the exposure apparatus 100 configured as described above when performing the exposure method of the present embodiment will be described with reference to FIGS. The description will be given along the flowchart with reference to other drawings as appropriate. In Table 1, the specific numerical values of the running conditions are shown, but for the sake of generalization, the following description will be made assuming that the running conditions shown in Table 2 below are used. In Table 2 below, it is assumed that the number of high-speed running conditions is N + 1 and each of the conditions is represented by (j = 0-N). In Table 2 below, the running conditions under condition j, that is, the scan length, scan speed, and step speed, are referred to as HSc, HVSc, and HVSt, respectively. This HSc, HVSc, HVSt,

Are (33mm, 25mm, 17mm), (30mm / s, 170mm / s, 2 Either 40mm / s, 300mm / s) or (30mm / s, 495mm / s).

Further, in Table 2, unlike in Table 1, the scanning direction is added to the scanning conditions. There are two scan directions, the + Y direction (ie, plus scan direction) and the one Y direction (ie, minus scan direction). In the present embodiment, plus scan and minus scan scan exposures are performed for the same combination of the scan length, scan speed, and step speed, respectively, so that the forward / reverse difference correction in the scan exposure can be corrected. A correction function for the plus scan and a correction function for the minus scan are created separately. Here, the forward / reverse difference means an offset generated between the formation position of the shot region formed by the plus scan and the formation position of the shot region formed by the minus scan. Therefore, as will be described later, an offset term for canceling the offset is given to one of the correction function at the time of the plus scan and the correction function at the time of the negative scan.

As shown in Table 2, in the present embodiment, for the above-described forward / reverse difference correction, the condition j as a combination of the scan length, the scan speed, the step speed, and the like, the scan in the plus scan and the minus scan, respectively. Each exposure must be performed. In low-speed running conditions, the scan length, scan speed, step speed, and scan direction are set to A and L w_def, respectively.

VSc, LVSt, Ld. The scanning direction Ld in the low-speed scanning condition is plus scanning (w w w w

+). HSc, HVSc, and HVSt as the scan length, scan speed, and step speed of condition 0 are the same values as A, LVSc, and LVSt, respectively, w, 0 w, 0 w, and 0 w_def w w

Suppose there is.

[0081] [Table 2]

FIG. 5 shows a flowchart showing the operation of main controller 20. First, in step 502, a wafer W for measurement is loaded onto a wafer stage τ by a wafer loader (not shown).

The reticle R is loaded on the reticle stage RST by the reticle loader (not shown) while being loaded on the WST.

τ

In the next step 504, preparation work such as alignment of the reticle is performed. Specifically, the reference mark plate FM on the wafer stage WST is positioned at a predetermined position directly below the projection optical system PL (hereinafter, referred to as “reference position” for convenience) via the wafer stage drive unit 24, and the reference mark The relative position between the pair of first fiducial marks on the plate FM and the pair of reticle alignment marks on the reticle R corresponding to the first fiducial mark is detected using the pair of reticle alignment detection systems 22 described above. . Then, main controller 20 stores in main memory the detection result of reticle alignment detection system 22 and the measurement values of reticle interferometer 16 and wafer interferometer 18 obtained through stage controller 19 at the time of detection. I do. Next, main controller 20 moves wafer stage WST and reticle stage RST in the opposite directions along the Y-axis direction by a predetermined distance, respectively, to form another pair of first fiducial marks on fiducial mark plate FM. And a pair of reticle alignment marks on reticle R corresponding to the first reference mark are detected using paired reticle alignment detection system 22 described above. Main controller 20 includes a reticle alignment detection system 22 And the measured values of the interferometers 16 and 18 at the time of the detection obtained through the stage controller 19 are stored in a storage device (not shown). Next, in the same manner as above, the relative positional relationship between another pair of first fiducial marks on the fiducial mark plate FM and the reticle alignment mark corresponding to the first fiducial mark is further measured. good.

[0083] Then, in main controller 20, information on the relative positional relationship between at least two pairs of the first reference marks obtained in this way and the corresponding reticle alignment marks, and the interferometer at the time of each measurement. Using the measured values of 16 and 18, the relative positional relationship between the reticle stage coordinate system defined by the length measurement axis of the interferometer 16 and the wafer stage coordinate system defined by the length measurement axis of the interferometer 18 is determined. Thus, the reticle alignment is completed. In the following scanning exposure, the scanning exposure is performed by synchronously moving the reticle stage RST and the wafer stage WST in the Y-axis direction of the wafer stage coordinate system. In this case, the reticle stage coordinate system is used. The reticle stage RST is scanned based on the relative positional relationship between the reticle stage and the wafer stage coordinate system.

Then, main controller 20 performs baseline measurement. Specifically, the wafer stage WST is returned to the above-described reference position, and is moved in the XY plane by a predetermined amount, for example, the design value of the baseline from the reference position, and the reference mark plate FM is used by using the alignment detection system AS. The upper second reference mark is detected (the measured value of the wafer interferometer 18 obtained via the stage controller 19 is stored in the main memory). Main controller 20 obtains information on the relative positional relationship between the detection center of alignment detection system AS and the second fiducial mark obtained at this time, and a pair of first and second wafers measured when wafer stage WST was previously positioned at the reference position. Information on the relative positional relationship between the fiducial mark and a pair of reticle alignment marks corresponding to the first fiducial mark, the measured values of the wafer interferometer 18 at the time of each measurement, the design values of the baseline, and the known values Based on the positional relationship between the first fiducial mark and the second fiducial mark, the distance (position) between the baseline of the alignment detection system AS, ie, the projection center of the reticle pattern and the detection center (index center) of the alignment detection system AS Relation). If this baseline is calculated, the wafer W (or wafer W) to be imaged by the alignment detection system AS

T

The upper mark and the like can be accurately positioned in the imaging field of view of the alignment detection system AS. In the next step 506, the counter value j is initialized to 0, and the first shot area (condition j (= 0) (plus scan) -th shot area) is set as an exposure target area. At this time, the minus scan flag is initialized (cleared). As described later, the main controller 20 refers to the minus scan flag for the scan direction when setting the high-speed running condition, and if the flag is cleared, the main controller 20 performs the plus scan. If it is set and set, a minus scan will be set.

[0086] In the next step 508, the running conditions for the stage controller 19 and the like are changed to the low-speed running conditions (low speed (fast), ie, scan length A, scan speed LVSc, and step speed LVSt shown in Table 2. , Scan direction Ld (+)). Then, in step 510, the stage controller 19 is instructed to position the wafer stage WST and the reticle stage RST at the running start position of the condition j (condition 0) (plus scan) shot area. As a result, the wafer stage WST and the reticle stage RST force are each positioned at the scanning start position. Then, in step 512, the stage controller 19 is instructed to perform scanning exposure under the set running conditions. As a result, the pattern on reticle R shown in FIG.

T T

(Scan) shot area.

In the next step 514, the scanning conditions are set to high-speed scanning conditions (scan length HSc, scan speed HVSc, and step speed HVSt of condition j). At this time, the scanning direction

'J

設定 Set as one of the conditions, this scan direction is set with reference to the minus scan flag. That is, if this minus scan flag is cleared, plus scan (+) is set, and if it is set, minus scan (1) is set. Here, since the minus scan flag has been cleared in step 506, plus scan is set as one of the high-speed running conditions. In step 516, the stage controller 19 is instructed to position the wafer stage WST and the reticle stage RST at the scanning start position. The scan start position is determined by taking into account the scan length HSc set as the scan condition j and the scan direction (here, plus scan), and taking a low speed scan at step 512 in the shot area force formed by the scan exposure.ショット With respect to the shot area formed on the wafer W under the conditions, + X direction and + Y

T Position (ie, the wafer stage WST is shifted by L in the X and Y directions from the acceleration start position in scanning exposure under low-speed scanning exposure conditions). ). In step 518, the stage controller 19 is instructed to start scanning exposure under a high-speed scanning condition (condition j (here, j = 0)). By the series of steps 508 to 518, a superposed shot area force is formed on the wafer W under the condition j (= 0) as shown in FIG.

T

In the next step 520, it is determined whether or not the counter value is j force ¾. If the determination is negative, the process proceeds to step 522, and if the determination is affirmative, the process proceeds to step 528. Here, since j = 0, the determination is affirmative and the routine proceeds to step 528. In step 528, the counter value j is incremented by 1 and the minus scan flag is cleared. After the completion of the step 528, the process returns to the step 508.

[0089] Thereafter, step 508, the processing of step 518 is executed again, the counter value j becomes 1, and the minus scan flag is cleared, so that an overlap exposure area related to condition 1 (plus scan) is formed. Then, in step 520, it is determined whether or not the counter value is j power SO. Since j = 1 here, the determination is negative, and the flow proceeds to step 522.

In step 522, it is determined whether or not a superimposed shot area related to condition j (minus scan) has been formed. If this determination is denied, the process proceeds to step 524, and if this determination is affirmed, the process proceeds to step 526. Here, since a superimposed shot area relating to the condition j (minus scan) has not been formed yet, the judgment is denied, and the routine proceeds to step 524. In step 524, the minus scan flag is set, and in step 508

[0091] Thereafter, since j = l and the minus scan flag is set, the processing of step 508 and step 518 is executed again, and an overlap shot area relating to condition 1 (minus scan) is formed. . Then, in step 520, it is determined whether or not the counter value is j force ¾. Here, since j = l, the determination is negative and the process proceeds to step 522.

[0092] In step 522, it is determined whether or not a superimposed shot area related to the condition j (minus scan) has been formed. Here, the overlapping shot area is already created As a result, the determination is affirmative and the process proceeds to step 526.

[0093] In the next step 526, it is determined whether or not the scanning exposure under all the scanning conditions has been completed (that is, it is determined whether or not the counter value j has become equal to or more than N. The determination is negative. For example, proceed to step 528, and if the judgment is affirmative, proceed to step 530. Here, since j = 1, the decision is denied and proceed to step 528. In step 528, j is incremented by 1 At the same time, the minus scan flag is cleared, and the process returns to step 508.

[0094] Thereafter, until the judgment is affirmed in Step 526, that is, until the counter value j becomes N or more, Step 508 → Step 510 → Step 512 → Step 514 → Step 516 → Step 518 → Step 520 → The overlap exposure region of the condition j (plus scan) is formed on the wafer W by the processing of Step 522 → Step 524, and further, Step 508 → Scan

τ

Step 510-> Step 512-> Step 514-> Step 516-> Step 518-> Step 5 20-> Step 522-> Step 526-> Step 528, the latent image of the overlap exposure area of condition j (minus scan) is placed on wafer W. Will be formed.

T

FIG. 8 shows an example of a pattern image (latent image) formed on wafer W. Fig. 8

T

In, the shot area formed by the scanning exposure under the high-speed scanning condition j is indicated by oblique lines. Since the correction function has not been created yet, the stage control device 19 is set so as not to correct the measurement value of the reticle interferometer 16 during the scanning exposure in steps 512 and 518.

[0096] If the determination is affirmative in step 526, that is, if it is determined that scanning exposure under all scanning conditions has been completed, the process proceeds to step 530. In step 530, the reticle loader (not shown) is instructed to unload the reticle R for measurement, and the wafer loader (not shown) is instructed.

T

On the other hand, an instruction is given to unload the wafer w. As a result, the reticle R

T T

The wafer W is unloaded from the RST and the wafer W is unloaded from the wafer holder 25

τ

The wafer is transferred to a coater (not shown) connected to the exposure apparatus 100 by a wafer transfer system (not shown). Thus, the exposure operation of the overlay exposure for measurement ends.

[0097] Then, main controller 20 executes the above-mentioned after the transfer of wafer W to the coater and the developer.

T

Then, the process proceeds to step 532 to wait until the development of the wafer W is completed. In this step 532

τ During the waiting time, the wafer W is developed by the coater / developer. This current τ

With the end of the image, 2N + 1 low-speed and 1-speed superimposed shot area

T

Is formed. The wafer w on which this resist image was formed

T Detects the dynamic characteristics of synchronous scanning of RST and WST, and serves as a sample for creating the above correction function. In the above-described embodiment, a plurality of conditions (condition 0

The present invention is not limited to this, and shows a mode in which printing is performed in the plus scan direction and the minus scan direction, respectively. For each condition (Condition 0-N), one wafer may be used, and several shots may be printed on one wafer in the plus scan direction and several shots in the minus scan direction under each condition. (For example, alternately print 11 shots of plus scan and 10 shots of minus scan). In this case, a wafer with a profile is used for each condition j (including plus scan and minus scan).

When baking 0-N, N + 1 wafers are used. The use of such a method (one wafer per condition) can increase the number of measurement data.

[0098] In the waiting state of the above step 532, when it is confirmed that the development of the wafer W has been completed by the notification from the control system of the coater and the developer (not shown), the process proceeds to step 534,

T

Instruct the wafer loader to load wafer W again on wafer holder 25, and

T

Proceed to step 602 of. Note that, in order to accurately detect the amount of displacement in the X-axis direction and the Y-axis direction, which will be described later, the wafer W is reloaded, and so-called raffamentation is performed.

T

, The shot coordinate system defined by the superimposed shot area formed on the wafer w

T

And the force required to match the wafer stage coordinate system Here, the description of the process is omitted, and the discussion proceeds assuming that the shot coordinate system and the wafer stage coordinate system match.

In step 602, the counter value j is initialized to 0, ρ is initialized to 1, and the minus scan flag is cleared. The minus scan flag is referred to when selecting a superimposed shot area for detecting a mark image, as described later. In other words, when the minus scan flag is cleared, the overlap shot area of the condition j (plus scan) is selected as a detection target, and when it is set, the overlap shot area of the condition j (minus scan) is set. The region is selected as a detection target. [0100] In the next step 604, since the minus scan flag has been cleared, the superposition shot area formed by the scanning exposure under the condition j (plus scan) is placed under the condition j. To determine whether or not the p-th mark image MP has been formed. Fig. 9 (

As shown in A), not all marks M on all reticles R are transferred to the wafer w as mark images MP, and the shot area with a short scan length is not always used.

τ

In some cases, the mark images MP of the marks M at both ends in the Y-axis direction are not formed (in FIG. 9 (A), a force indicating a shot area with a scan length of 17 mm is shown at both ends in the Y-axis direction). The mark image MP is not formed as shown by the dotted line). Therefore, in this step 604, it is determined whether or not the mark image MP is formed based on the scan length HSc of the condition j. Here, if the determination is affirmative, the process proceeds to step 606, where the determination is, j

If not, proceed to step 620. Here, it is assumed that the determination is denied and the process proceeds to step 620. At step 620, the counter value p is incremented by 1 and the process returns to step 604 again. Thereafter, the loop processing from step 604 to step 620 is repeated until the determination in step 604 is affirmative.

[0101] If the determination is affirmative in step 604, the process proceeds to step 606. In step 606, the wafer stage for matching the imaging field of view of the alignment detection system AS with the pattern image MXP (FIG. 9B) of the mark image MP in the superimposed shot area for the condition j (here, j = 0) The stage controller 19 is instructed to position the WST. At this time, it is determined based on the minus scan flag whether a force to detect the overlap shot area under the condition j (plus scan) and a detection target from the overlap shot area under the condition j (minus scan) are used. Is done. That is, when the minus scan flag is cleared, the condition j (plus scan) is set as the detection target, and when the minus scan flag is set, the condition j (minus scan) is set as the detection target. Here, since the minus scan flag has been cleared, the overlap shot area of the condition j (plus scan) is selected. Here, j = 0, and the overlap shot area of the plus scan is naturally selected. In this case, the baseline measured in advance is taken into account. Then, in step 608, imaging is instructed to the alignment detection system AS, and the imaging result is acquired from the alignment detection system AS. [0102] In the next step 610, the X-axis direction of the mark image MXP is obtained from the obtained imaging result.

P

Detect the displacement amount. FIG. 9C shows an enlarged view of the pattern image MXP.

P

As shown in FIG. 9 (C), the mark M formed by scanning exposure under low-speed scanning conditions

P

If the image of mark M formed by running exposure under high-speed running conditions is displaced in the X-axis direction, the L / S at both ends of pattern image MX 'and pattern image MX'

twenty one

Each distance from the pattern is different from LI and L2. In FIG. 9 (C), the displacement amount is indicated as dx. In the present embodiment, the respective center distances are calculated from the image data of the acquired imaging results based on the mirror symmetry positions of the LZS patterns, and the average of the differences between them and Ll and L2 and the alignment detection system AS Based on the imaging magnification of, the amount of displacement dx of the mark image MP in the X-axis direction is calculated. Then, the calculated displacement amount dx is stored in a storage device (not shown).

[0103] In the next step 612, the imaging field of view of the alignment detection system AS is changed to the pattern image MYP (Fig. 9 (B)) of the mark image MP of the superimposed shot area under the condition j (here, j = 0). In order to make them coincide, the controller instructs the stage controller 19 to position the wafer stage WST. In step 614, the imaging is instructed to the alignment detection system AS, and the imaging result is obtained from the alignment detection system AS.

[0104] In the next step 616, the L / S pattern image M related to the mark image MYP from the imaging result acquired in the step 614, similarly to the positional deviation amount dx in the X-axis direction detected in the step 610.

P

Detects the amount of displacement dy in the Y-axis direction between Y 'and the L / S pattern image MY'. And calculate

1 2

The position shift amount dy is stored in a storage device (not shown).

[0105] In the next step 618, it is determined whether or not the imaging of all the mark images MP in the superimposed shot area for the condition j (here, j = 0) has been completed. If the determination is negative, the process proceeds to step 620, and if the determination is positive, the process proceeds to step 622. Here, the imaging of all the marks M has not been completed yet, the judgment is denied, and the process proceeds to step 620.

P

Shall be considered. After p is incremented by one at step 620, the process returns to step 604.

[0106] Thereafter, until the judgment is affirmed in step 618, step 604 (if there is no mark image MP formed under the high-speed running conditions, the steps from step 604 to step 620 are repeated. Step 606 → Step 608 → Step 610 → Step 612 → Step 614 → Step 616 → Step 618 → Step 620 are repeatedly executed.

[0107] When the measurement for all the mark images MP is completed and the determination in step 618 is affirmative, the process proceeds to step 622, where it is determined whether or not the counter value j = 0. If this determination is affirmative, the process proceeds to step 624, and if negative, the process proceeds to step 626. Since j = 0 here, the judgment is affirmative and the routine proceeds to step 624.

At step 624, the counter value j indicating the shot area number is incremented by 1, the counter value p indicating the mark image MP number is initialized to 1, and the minus scan flag is cleared. Then, after the end of step 624, the process returns to step 604.

[0109] Thereafter, the processing of step 604 and step 620 is executed again, and in step 618, each mark image MP in the superimposed shot area in condition j (here, condition 1 (plus scan)) is superimposed until the determination is affirmed. The displacements dx and dy are detected. Then, when the determination is affirmed in the next step 618, it is determined in step 622 whether or not j is 0. Here, since j = l, the determination is negative and the process proceeds to step 626.

[0110] In step 626, it is determined whether or not the measurement for the condition j (minus scan) has been completed. If this determination is denied, the process proceeds to step 628, and if this determination is affirmed, the process proceeds to step 630. Here, since the measurement relating to the condition j (minus scan) has not been completed, the determination is denied, and the process proceeds to step 628.

[0111] In step 628, the counter value p is substituted for 1, and the minus scan flag is set. After step 628, the process returns to step 604.

[0112] Thereafter, step 604 (or step 604 → loop processing of step 620) → step 606 → step 608 → step 610 → step 6 12 → step 614 → step 616 → step until the determination in step 618 is affirmed 618 → Step 620 is executed repeatedly

In the superimposed shot area under the condition j (minus scan), the positional shift amount dx in the X-axis direction and the positional shift amount dy in the Y-axis direction in the formed mark image MP are detected. If the determination in step 618 is affirmative, the flow advances to step 626 via step 622, and the measurement of the superimposed shot area under the condition j (minus scan) has already been completed. Therefore, the determination is affirmative, and the routine proceeds to step 630.

[0113] In step 630, it is determined whether or not the value of the counter value j has become N or more.

If the judgment is denied, the process proceeds to step 624, and if the judgment is affirmed, the process proceeds to step 626. Here, since j = l, the determination is negative and the process proceeds to step 624. In step 624, the counter value j is incremented by one, the counter value p is initialized to one, and the minus scan flag is cleared. After step 624, the process returns to step 604.

[0114] Thereafter, in step 630, until the determination is affirmed, step 604 (or step 604 → loop processing of step 620) → step 606 → step 608 → step 610 → step 6 12 → step 614 → step 616 → Step 618 → Step 620 are repeatedly executed, and the positional deviation amounts dx and dy of the mark image MP in the overlay exposure area for the condition j (positive scan) are detected. Further, Step 622 → Step 626 → Step 628 are executed. Then, step 604 (or the loop processing of step 604 → step 620) → step 606 → step 608 → step 610 → step 612 → step 614 → step 616 → step 618 → step 620 is repeatedly executed, and the condition j (minus The position shift amounts dx and dy of the mark image MP in the overlay exposure area for (scan) are detected. And stet

P

Steps 622 → Step 626 → Step 630 → Step 624 are executed, and thereafter, the positional deviation amounts dx and dy of the mark image MP in the overlapping exposure area for the next condition j (plus scan) are detected.

[0115] When the measurement for all the superimposed shot areas is completed, the determination in step 630 is affirmed, and the flow proceeds to step 632.

[0116] In the next step 632, a reticle manufacturing error is removed from the displacement amount dx in the X-axis direction and the displacement amount dy in the Y-axis direction in each mark image MP in each superimposed shot area. Here, the reticle manufacturing error refers to the reticle R shown in FIG.

T

This is an error that occurs when the mark M shown in FIG. 3 is not formed as designed. When such a reticle manufacturing error is large, a component of the reticle manufacturing error may be included in the positional deviation amounts dx and dy detected in steps 610 and 616 to an extent that cannot be ignored.

Thus, in the present embodiment, the reticle manufacturing error component is canceled from the displacement amounts dx and dy. In order to perform celling, scanning exposure is performed on one superposed shot area under the same scanning condition (the above condition 0 (plus scan)) as that under the low-speed scanning condition. In this way, the positional deviation amount dx detected in each mark image MP on the superimposed shot area is obtained.

P

, Dy can be regarded as a component due to a reticle manufacturing error. Therefore, from the misalignment amounts dx and dy of each mark image MP detected under the other conditions

P

By subtracting the positional deviation amounts dx and dy of the mark images MP, the condition 1

P

In this case, the amount of positional deviation from which the influence of the reticle manufacturing error has been removed can be detected. In the following, the displacement amounts in the X-axis direction and the Y-axis direction in which the influence of the reticle manufacturing error has been removed are given by subscripting the number p corresponding to each mark and the number j of the shot area, respectively. , Dx and dy.

P.j P, j

[0118] As described above, the positional deviation amounts dx and dy are formed by running exposure under running condition j.

P.J P, J

It can be considered that the shot distortion component is the shot distortion component of the shot region j (the forward / reverse difference component is also included in the condition j (minus scan)). Therefore, the correction function created below is created as a function for correcting shot distortion components and the like.

[0119] << Method of creating correction function >>

In the next step 634, a correction function for correcting the measurement value of the reticle interferometer 16 is created. Hereinafter, a method of creating the correction function will be described in detail.

First, a description will be given of a dynamic characteristic model of synchronous scanning of both stages, which is a premise for creating a correction function. FIGS. 10A and 10B schematically show shot areas formed by scanning exposure. FIG. 10 (A) shows a shot area at the time of a plus scan, and FIG. 10 (B) shows a shot area at the time of a minus scan. The coordinate axes X and y of the shot coordinate system on the wafer W are coordinate axes having the origin at the center of the shot area.

T w'j w'j

And the directions are the same as the X axis and the Y axis, respectively. The width of the shot area in the X-axis direction is B at both the plus scan and the minus scan.

[0121] During scanning exposure, both stages WST and RST are synchronously scanned in directions opposite to each other. The wafer stage WST, in the case of plus scan, moves in the + Y direction (+ y direction)

In the case of the eggplant scan, since scanning is performed in the Y direction (_y direction), FIGS. 10 (A) and 10 (B) As a result, the exposure area (the width in the Y-axis direction (slit width) is S) is ゥ w

On the wafer W, it moves in one y direction during the plus scan, and

T w'j

Move in + y direction. Figures 10 (A) and 10 (B) show the acceleration start position and w, j

The exposure region at the time when the scanning speed is reached and the scanning speed is reached, the exposure region at the time when the shot region j is reached, and the exposure region at the time when the shot region is exited are indicated by oblique lines.

[0122] In the scanning exposure, the damped oscillation generated on the wafer stage WST due to the overshoot when the wafer stage WST accelerates and then starts moving at the scan speed (constant speed) is used. Considering this, a section (also referred to as a margin or settling section) is provided between the position at which the scan speed is reached (the scan speed reached position) and the exposure start position to sufficiently converge the vibration. . Assuming that the settling time until the damped oscillation converges is T and the scan speed of the wafer stage WST is V, the length of the section is T X w, j

V. Also, w, j from the center of the shot area to the center of the exposure area at the exposure start position

The distance is (S + HSc) / 2.

, J

In the present embodiment, a function model of a correction function is defined based on a shot coordinate system as shown in FIGS. 10 (A) and 10 (B).

[0124] As described above, the positional deviation amounts dx and dy to be canceled by this correction function are determined by the shot

J P

The distortion components dx and dy are included in the shot coordinate system.

P, J

Can be considered to be dependent on the position coordinates within. Therefore, it is necessary to model the correction function for canceling the above-mentioned positional deviation so as to include the coordinate values of the shot coordinate system as independent variables as shown in FIGS. 10 (A) and 10 (B). is there.

From the above, for example, when a correction function is created, the coordinate values of the wafer stage coordinate system (the coordinate values on this coordinate system are _x and _y ) are the coordinates on the shot coordinate system. Must be converted to a value. This conversion can be easily performed by subtracting the X position and the γ position on the wafer coordinate system of the center of the measured value X, y force in the shot area.

Further, since the correction function of the present embodiment is a function for correcting the measurement value of the reticle interferometer 16 that defines the reticle stage coordinate system, the position coordinates handled by the correction function are It must be position coordinates on the shot coordinate system in tickle conversion. Let X and Y be the coordinate axes of the shot coordinate system in reticle conversion. The directions of the coordinate axes X and Y are assumed to be the same as the coordinate axes x and y of the shot coordinate system in wafer conversion. Since the projection magnification is 1 / M, as described above, by executing the following equations (1) and (2), the measured values X and Y of the reticle coordinate system in the reticle coordinate system can be calculated. Can be converted c

r r, j

[0127] [Number 1]

^X ri ⁼ one, ^M " _P … hi)

Here, both equations (1) and (2) are negatively converted because the relation S between the pattern on the reticle and the pattern image on the wafer is an inverted relation. is there.

[0128] In addition, the above-described positional deviation amounts dx and dy also need to be converted into reticle-converted positional deviation amounts dx, dw, jw'jr'jy. Direction (r, J must be corrected)

Is positive, the following expressions (3) and (4) are obtained.

[ _Equation 2] dx _rj = dx _W χ M _exp '

Also, the scan speed V of the wafer stage WST and the scan w, j of the reticle stage RST

The relationship with the speed V is as follows.

[Equation 3] vw ^{= vx M} " _P ^/ vi>,... ( ⁵ ) where V is a normalized speed in reticle conversion.

Β

As described above, a settling time is provided between the time when the scanning speed is reached and the time when the exposure is started, in order to converge the damped oscillation due to the overshoot, but this settling time is short. If the exposure is started without sufficient attenuation of the vibration, the displacements dx. And dy will include a component of the displacement due to the vibration. So, the scanning speed Set the time axis h with the time of arrival at the origin as the origin, and make the correction function include the time h during the scanning exposure as an independent variable. Note that the stage control device 19 includes scanning exposure,

It is assumed that a timer for measuring the middle time h is provided.

,

In the present embodiment, a correction function for correcting the measurement value of reticle interferometer 16 for measuring the position of reticle R (actually, reticle stage RST) is created based on the scanning exposure model described above. I do. Note that the correction function for correcting the measurement value of the X interferometer of the reticle interferometer 16 is dx (Y, h), and the correction function for correcting the measurement value of the Y interferometer is dy (Y, h).

Further, in the present embodiment, as described above, the correction functions are separately created for the plus scan and the minus scan. First, regarding the correction function dx (Y, h) in the X-axis direction and the correction function dy (Y, h) in the Y-axis direction during plus scan, the following equation (6) is used.

, Defined as in equation (7).

[Equation 4] dx _r Y _r , h _r ) = v ∑ ;: f, (, _t χ f (Y _r , k))

+ (, _A ,,,, xg (^, ri)-(6)

[0135] [Number 5]

In the above equations (6) and (7), f (Y, k) is the coordinates Y and k of the shot coordinate system in reticle conversion (in equation (6), k = 1 P, and the equation (6) In (7), k = l-q for terms containing X, and k = and q for terms not containing X). In Equations (6) and (7), the term including f (Y, k) is called the position term (first term). C, C, and C are coefficients of a term including f (Y, k), respectively,,,,

The subscripts Y and XY indicate the position where the coefficient C includes the coordinate value Y or the coordinate values Υ and χ,

It indicates that it is the coefficient of the term. Also, the subscript f indicates that the coefficient is Means the coefficient of the correction function. In the following, when referring to all the coefficients of each term of the correction function, these coefficients are simply referred to as “coefficient c”. When a correction function is created under one condition of low-speed and high-speed superposition, Equation (6) is a function of only the first term on the right side or only the second term on the right side. Equation (7) is a function up to the second term on the right side.

In the above equations (6) and (7), g (h, 1) is the time h and 1 during scanning exposure (equations (6,

), 1 = 1-1 p, and in equation (7), 1 = 1-q) is a function with independent variables.

. The term containing g (h, 1) is called the time term (second term). C in equation (6) and C in equation (7) are,,

g is a coefficient of a term containing (h, 1), and the subscript h indicates that the coefficient is a coefficient of a time term containing time h.

In the present embodiment, the correction function dx (Y, h) in the X-axis direction does not include the first-order and function terms of X, and the correction function dy (Y, For h), the term of the linear function of X (third term) is included. By doing so, the shift of the Θz component between reticle stage RST and wafer stage WST can be corrected by correcting the correction function in both axial directions. Note that the correction function dy (Y, h) in the Y-axis direction

The reason that the first-order term of the Y-interferometer is included in the reticle interferometer 16 is that the Y-interferometer is a two-axis interferometer. This is because it is easy to correspond to the correction function of the interferometer. In this embodiment, the components that can be corrected by correcting the measurement values of each interferometer of the Y interferometer are limited to the first-order components of X. , X does not include functions of second order or higher. Correcting the measurement values of each interferometer of the Y interferometer (two-axis interferometer) also means that the shape of the shot to be transferred is deformed in the Y-axis direction. It also means to correct the rotation error component (jewing error component) in the Y-axis direction. The above-described correction function in the Y-axis direction (Equation (7)) is applied to each axis of the Y interferometer, and the measured values of each interferometer of the two-axis interferometer are corrected. .

In the present embodiment, the function f (Y, k) and the function g (h, 1) are represented by the following equations, respectively.

Equations (8) and (9) can be used.

[0139] [Number 6] f (Y _r , k) = 0, / — '(8)

[0140] [Equation 7] g (h _r ) = sin ( _{|| g} „), 0 ≤ h _r ≤ H

(9)

₈ (, 0 = 0, Η- _p h h _{r In} other words, as shown in the above equation (8), f (Y, k) is a power function of the Y position Y in the shot.

,, And numbers. As can be seen from equation (8), k in f (Y, k) indicates the power function multiplier. Therefore, if this multiplier is 1 (first order), the correction function dy (Y, h

,

) Is a function for correcting the scaling in the Y-axis direction. If this multiplier is 0 (0th order), the correction function dy (Y, h) expressed by the equation (7) is viewed from the Y-axis direction. It is a function to correct the rotation error component of the stage at the time.

[0141] Further, as shown in the above equation (9), it is assumed that g (h, 1) is a sine function. From equation (9)

,

As can be seen, H is the time required for the damped oscillation of the stage due to the overshoot occurring at the stage to converge when the stage switches from acceleration to constant speed, and g (h, 1) 1 is a number corresponding to the frequency of the damped oscillation. Once H and 1 are determined, g (h, 1) will be determined.

On the other hand, the correction function dx (Y, h) in the X-axis direction and the correction function dy (Y, h) in the Y-axis direction at the time of the minus scan are defined as follows.

[Equation 8] x _r (Y _r j =, ∑, / (y _r ))

[0144] [Number 9] ^ r (Yr, j, j = V _r ,, XX _rJ X Σ (-f {Y _r , k))

⁺ ∑ :: '(, / (1))

+ ^ ∑ (,)) + ^ ,. ,-(11) That is, in the above equations (10) and (11), the point force plus dx, 0, b, 0, c is provided as the offset term in the dy, 0, b, 0 Equations (6) and (7), which are the time correction functions, are different. This offset term is a term corresponding to the above-described forward / reverse difference correction.

When a correction function is created under one condition, Expression (10) is a combination of the first and third terms on the right side or a combination of the second and third terms. Equation (11) is a function of the combination of the first, second, and fourth terms on the right side. As the f (Y, k) in the expressions (10) and (11), the expression (8), that is, the “power function” can be applied. For this reason, similarly to the correction function at the time of the plus scan described above, the correction function dy (Y

r, j r, j

, h) is a function for correcting the scaling in the Υ-axis direction or a function for correcting the rotation of the stage. The suffix b of the coefficient C indicates that the coefficient is a coefficient of the correction function at the time of the minus scan, and the meanings of the other suffixes are the same as in the above equations (8) and (9). It is. The function g (h, 1) of the time term at the time of the minus scan is represented by the following equation.

[0146] [Equation 10] g (,., /) = Sin (--)> tmn_ m <A .. <0

(12)

, /) 0 where H is the stage change from acceleration to constant speed during minus scan mm—m

Is the time until the damped oscillation of the wafer stage WST caused by the overshoot generated in the control system of the reticle stage RST or the wafer stage WST converges, and 1 of g (h, 1) is the damping This is a number corresponding to the frequency during vibration.

r, J

[0147] The dx (Y, h) shown in the above equation (8) is converted into a matrix r'J r, j r'j for each scanning condition j (j = l-N).

Expressed as follows, [0148] [Number 11]

ax.,

dx.

That is, the correction function dx (Y, h) is determined by the scan speed ν and the function f (Y, k) or the function

We can express S by the product of the matrix with the product of the numbers g (h, 1) and the column vector of the coefficient C. The above equation (13) is summarized as follows.

[0149] [Number 12]

(14) where ξ is a column vector with the elements of the correction function dx (Y, h) under each scanning condition j as elements, and Ψ is a matrix with elements such as vxf (Y) And Θ is the column vector of the coefficient C for each term.

[0150] Further, the correction function dy (, Y, h) is also defined by the matrix r, J r'j as shown in the above equation (14) for each scanning condition j (j = l-N).

Can be expressed by Here, let 要素 be the element of row j of ξ, Θ be the element of row m of Θ, and Θ be the element of row j and m of Ψ. mj, mmjj, m

Can be

[0151] [Equation 13] = ^ r • (15)

[0152] [Number 14]

C, 0 is m <q _XY

Y, m- _ixr + ι ¾ _Χ1 , <m <q _XY + q _Y ■■■ (16) y, h, m- _qx y- _qi +1 ¾ _xr + <m <q _XY + q _r + q _h

[ _Equation 15] v _rj X _rj f (Y _rj , m + l) ≤m <q _XY

Ψ — = ^v r, jf (y _r > mq _XY + l) q _XY ≤ <q _xy + q _y … (17) vr S (K, w- _{? Xy} +1) q _XY + q _Y ≤m <q _XY + q _Y + q _h Further, the correction function dx (Y, h) in the X-axis direction at the time of the negative scan shown in the above equation (10) is calculated using the above equation for each scanning condition j (j = l-N). It can be expressed by a matrix as shown in (14), and its elements Θ,, Ψ can be expressed as follows.

m j j, m

[0154] [Number 16]

• (18)

[0155] [Number 17]

C dx, Y, m + \ 0≤

C, m = p _Y + p _h [ _Equation 18] v _rj f (Y _r , m + l) 0 <m <p _Y

Ψ.

+ 1) p _Y ≤m p _Y + p _h (20)

1 rn = p _Y + p _h Further, the correction function dy (Y, h) in the X-axis direction at the time of the minus scan shown in the above equation (11) is calculated with respect to each running condition j (j = l-N). The matrix r, J r'j as shown in the above equation (14)

The elements θ, Ψ, and 表す can be expressed as follows.

m j j, m

[0157] [Number 19]

[0158] [Number 20]

C 0 <m <q _XY

cg _xy ≤ q q _XY + q _Y

,(twenty two)

C i.fy, A, Wl-y

C m = q _XY + q _Y ⁺ q _h

[0159] [ _Equation 21] v _r; X _rJ / (y _rJ , m + l) 0≤m <q _XY

v _r f {Y _r > mq _XY + l) q _XY ≤m <q _XY + q _Y

• (23) v _r , jg ( ^h _r j, ^m- 1 9χγ-¾ ⁺ !) 9 _xr + ¾y ≤ m <q _XY + q _r + q _h

In _{_{1 m = q XY + q y}} + q step 634 _h 6, finally, the equation (6), equation (7), equation (10), but to create a correction function of Equation (11), As described above, these correction functions are functions for transferring the pattern by scanning exposure without positional deviation, and for canceling the positional deviation amounts dx and dy derived in step 632. It is. Therefore, no position

P, j P.j

The quantities dx and dy can be applied as the value of each element of ξ.

P'J PJ

[0160] Also, the values of the elements of the matrix 式 are calculated by the above equations (8) and (9), It is clear from the position coordinates in the design of the coordinate system and V in each scanning condition j. As a result, the correction functions dx (Y, h) and dy (Y, h

r'j r'j r, j r, j r'j

In equation (14) above, the value of each element is unknown because the columns r and J of the coefficient C of each term

Vectonore only. Therefore, for example, with respect to the correction functions dx (Y, h) and dy (Y, h) at the time of plus scan and minus scan,

r, J r'j r, j r'j r, j r'j

If so, the coefficient C of each term for each function can be obtained.

In step 634 of FIG. 6, the least square method is applied to the correction function (Y, h) and dy (Y, h) at the time of plus scan and minus scan by applying the least square method to r, jr. , jr, jr, jr, jr, j

To find the coefficient C for each term. That is, the above equation (14) can be transformed into the following equation to obtain an estimated value of Θ.

[0162] [Equation 22] θ ^ (Ψ ^τ Ψ) ' ^ι Ψ ^τ ξ' · · (24)

Where β is an estimated value of 0, where Ψ is the transpose of Ψ, and (Ψ Ψ) is the inverse of (Ψ Ψ).

[0163] Actually, in the present embodiment, it is easy to obtain an estimated value of Θ by LU-decomposition of expression (14) instead of obtaining the estimated value of から from the above expression (24). is there.

[0164] Therefore, in step 634 of FIG. 6, by LU decomposition, the correction function dx (Y, h) and dy (Y, h) for the plus scan and the correction function dx (Y, h) for the minus scan are obtained. r'j r, j r'j r, j r'j r, j r'j r, j r'j

, Dy (Y, h) can be obtained by calculating the coefficient C of each term. R, j r'j r, j

Each coefficient C is set in the stage control device 19 as a parameter of a correction function used in the stage control device 19. After completing step 634, the process proceeds to step 702 in FIG.

In step 702 of FIG. 7, reticle R is loaded on reticle stage RST using a reticle loader (not shown).

[0166] In the next step 704, a reticle alignment is performed by, for example, the reticle alignment detection system 22 in the same manner as in step 504 described above. Also, here, the main controller 20 uses the correction function at the time of scanning exposure to the reticle Instruct to correct using the measurement value of interferometer 16.

Next, in step 706, main controller 20 instructs a control system of a wafer loader (not shown) to unload wafer W and load wafer W. This allows the wafer port

T

The wafer W from the wafer holder 25 on the wafer stage WST.

τ

And the wafer W is loaded on the wafer holder 25. Here, it is assumed that the wafer W is a bare wafer on which a shot area has not yet been formed.

[0168] In the next step 708, by detecting the outer edge of the wafer including the notch (or orientation) on the wafer W, the deviation of the direction and center position of the wafer W on the wafer stage WST is roughly detected. The wafer W is adjusted according to the deviation, so-called raffamentation is performed.

In the next step 710, for example, the scan speed (V) and the scan speed registered in the process program for the wafer W transmitted from the host computer or the like of the lithography system on which the exposure apparatus 100 operates are registered. The scanning conditions such as length and scanning direction are set in the stage controller 19. As a result, the stage control device 19 substitutes the scan speed V for V of the correction function of the above equations (6), (7), (10), and (11).

[0170] In the next step 712, the counter g indicating the array number of the shot area is set to 1, and the first shot area is set as an exposure target area.

[0171] In step 714, wafer stage WST is moved so that the position of wafer W becomes an acceleration start position for exposing the shot area, and reticle stage RST is moved so that the position of reticle R becomes the acceleration start position. To move.

[0172] At step 716, the stage controller 19 is instructed to start the relative movement between the reticle stage RST and the wafer stage WST. Under the control of the stage controller 19, when the two stages reach their respective target scanning speeds and reach a constant-speed synchronization state, the pattern area of the reticle R starts to be illuminated by the illumination light IL from the illumination system 10, and scanning exposure is started. Be started. That is, the relative movement is performed by controlling the wafer stage drive system 24 and the reticle stage drive system while monitoring the measurement values of the wafer interferometer 18 and the reticle interferometer 16 by the stage controller 19. Then, different areas of the pattern area of the reticle R are sequentially illuminated with the illumination light IL to illuminate the entire pattern area. Is completed, the scanning exposure ends. Thereby, the pattern of the reticle R is reduced and transferred to the exposure target area on the wafer W via the projection optical system PL.

[0173] During this scanning exposure, the stage controller 19 converts the measurement values of the reticle interferometer 16 into coordinate values of the in-shot coordinate system, and converts the converted coordinate values X, Yr, J of the shot coordinate system. r'J and the time h during scanning exposure obtained from a timer (not shown) are corrected by a correction function (plus scan r, J

In the case of, the above equations (6) and (7) are used, and in the case of a minus scan, the above equations (10) and (11) are substituted), and the correction function calculated by the substitution is used. Is subtracted from the measured force of the reticle interferometer 16 (since the correction amount is calculated as positive, in other words, the direction in which the correction is effective (the direction in which correction is required) is positive), and the subtraction is performed. The value is used as the current reticle stage RST position for reticle stage position control (feedback control system). In this way, the position of reticle stage RST is corrected, and the shift of the transfer position of the pattern due to the dynamic characteristics during the scanning exposure of both stages is canceled. Note that the X position of the in-shot coordinates of each axis interferometer of the two-axis interferometer is substituted for X of the correction function for the Y-axis direction. Also, when applying the correction function, it is necessary to convert the measured value of the reticle interferometer 16 into the shot coordinate system, and to use the measured value corrected by the correction function as the feedback control amount, Needless to say, the values need to be converted into position coordinates in the reticle stage coordinate system. As described above, the use of the correction function (particularly the correction function in the Y-axis direction) used during scanning exposure is different between the plus scan and the minus scan, in other words, the plus scan and the minus scan. It means that the scaling correction value in the Y-axis direction can be used properly. In addition, the use of the correction function applied to each of the two-axis interferometers in the Y-axis direction for plus scan and minus scan means that, in other words, the yaw correction value in the Y-axis direction for plus scan and minus scan. That is to use properly.

[0174] In the next step 718, by referring to the counter value g, it is determined whether or not all shot areas have been exposed. If this determination is denied, the process proceeds to step 722; otherwise, the process proceeds to step 724. In this case, since g = l, that is, only the first shot area is exposed, the determination in step 718 is denied, and the process proceeds to step 720. In step 720, the value of the counter g is incremented (gg + 1), the next shot area is set as an exposure target area, and the flow returns to step 714.

[0176] Thereafter, the processing and determination of Step 714 → Step 716 → Step 718 → Step 720 are repeated until the determination in Step 718 is affirmed, and the scanning exposure is performed on all shot areas on the wafer W. Transfer the pattern. If the running conditions are changed for each shot area, the running conditions such as scan speed, scan length, and scan direction must be changed before each shot area is exposed. At the time of step movement), it is necessary to set the stage controller 19.

[0177] When the transfer of the pattern to all the shot areas on wafer W is completed, the determination in step 718 is affirmative, and the flow proceeds to step 722.

At step 722, an unloading of the wafer W is instructed to a wafer loader (not shown). As a result, the wafer W is unloaded from above the wafer holder 25 by a wafer loader (not shown) and then connected inline to the exposure apparatus 100 by a wafer transfer system (not shown). Transported to Then, a series of exposure processing operation ends.

In the present embodiment, after step 634 in FIG. 6, the process may return to step 502 in FIG. 5 and repeat step 502—step 634. In this case, when performing the scanning exposure in steps 512 and 518, the coefficient C of the created correction function is set in the stage controller 19, and during the scanning exposure in steps 512 and 518, The measured value of the reticle interferometer 16 shall be corrected. Then, after performing Step 512 and Step 518 while performing scanning exposure in the case where the correction function is applied, the displacement amounts detected in Step 610 and Step 616 in FIG. 6 are dx ′ and dy ′. .

[0180] These dx 'and dy' are shot distortion components that are generated even when the value of the reticle interferometer 16 is corrected by the correction functions dx (Y, h) and dy (Y, h). , Including the inverse difference component). Therefore, after that, the correction function newly created in step 634 is added to the correction functions dx (Y, h) and dy (Y, h) previously created, and the addition result is added to the new correction function dx (Y.h). , h), dy (Y, h ), It is possible to create a correction function that cancels the remaining shot distortion components.

[0181] As described above, in the present embodiment, by performing Step 502 to Step 634 a plurality of times, the correction functions dx (Y, h) and dy (Y, h) can be controlled with higher accuracy. Function

r, J r'j r'j r, j

Correcting power S can. At this time, the number of executions of step 502 and step 634, that is, the number of corrections of the correction function can be a predetermined number. Further, the displacement amounts dx and dy in the X-axis direction or the Y-axis direction detected in steps 610 and 616 are determined.

P.J It is good to repeat the process of step 502 and step 634 until the value decreases by P, J and becomes equal to or less than the predetermined amount.

In the present embodiment, it is assumed that the condition 0 is the same as the low-speed running condition, and the position shift amount as the overlay exposure result under this condition is calculated. Was used as a reticle manufacturing error, but the present invention is not limited to this. That is, the mark formed on the reticle R has a sufficiently small manufacturing

T

When it can be considered that the image is formed in the same manner, it is not necessary to perform the step 632 which is not necessary to perform the overlapping scanning exposure under the same scanning condition as the low-speed scanning condition. In this case, the positional deviation amounts dx and dy detected under the respective conditions j can be made to correspond to the column vectors の of the above equation (14) and the like.

[0183] Even when such a reticle manufacturing error exists, if the value of the error is known, it is not necessary to perform the overlay scanning exposure under the same conditions as the low-speed scanning conditions. In this case, in step 632, the value of the known reticle manufacturing error may be subtracted from the positional deviation detected under each condition j.

[0184] Also, the stage controller 19 corrects the measured value of the position of the wafer stage WST measured by the wafer interferometer 18 by setting the direction in which correction is effective (the direction in which correction is required) to be positive by the correction function. Even if it has a function to do. Also in this case, similarly to the control of reticle stage RST, whether or not to correct the measurement value of wafer interferometer 18 using this correction function during scanning exposure is determined by an instruction from main controller 20. The parameters that define the correction function, such as the coefficients of each term of the correction function, can be set from the main controller 20 to the stage controller 19. Thus, the correction with the correction function This can be done by using either the measured value of the reticle interferometer 16 or the measured value of the wafer interferometer 18. Note that, depending on the degree of the correction function by the correction function, the correction amount is distributed to both the reticle interferometer 16 and the wafer interferometer 18 (the direction in which the correction is effective is positive), and the measured values of both interferometers are measured. The correction may be made.

As is clear from the above description, in the present embodiment, main controller 20 corresponds to the transfer device, the acquisition device, the function creation device, and the function correction device of the exposure apparatus of the present invention. . That is, the function of the transfer device is realized by the processing of Step 508 and Step 526 (FIG. 5) performed by the CPU of the main control device 20, and the function of the acquisition device is realized by the processing of Step 602 and Step 632 (FIG. 6). 634 (Fig. 6) realizes the function of the function creation device. In the case where Step 502-Step 634 is executed a plurality of times, the function of the function correction device is realized by the processing of Step 502 and Step 634 for the second and subsequent times. Further, in the present embodiment, the stage control device 19 corresponds to the control device of the exposure apparatus of the present invention. However, it goes without saying that the present invention is not limited to this. For example, the functions of the main controller 20 and the stage controller 19 may be realized by one CPU.

[0186] As described above, according to the exposure apparatus 100 of the present embodiment, at least one mark M formed on the reticle R by the scanning exposure is each subjected to a plurality of different scanning conditions (condition j). Transferred, and information on the deviation of the mark transfer position from the reference position (dx, dy

) Is acquired for each scanning condition, and the correction amount of the measurement value of the position of the wafer w in the XY plane is determined as a dependent variable using an optimization method based on the acquired information and each scanning condition. Create correction functions dx (Y, h) and dy (Y, h) to correct the measured value of the position of wafer W.

,

Then, the pattern on the reticle R is transferred onto the wafer W while controlling the position of the wafer W or the reticle R based on the corrected measurement value.

[0187] Therefore, according to exposure apparatus 100, a correction function dx (Y

, h) and dy (Y, h) can be created, so that high-precision exposure can be realized in a short time.

In the above embodiment, the independent variables of the correction functions dx (Y, h) and dy (Y h) When the time h during scanning exposure is used, but the time h during scanning exposure is unknown, the time h is converted into the in-shot coordinate y as in the following equation, and the correction function is calculated using only the shot coordinate value. Is r, J w'j

The function may be set as an independent variable.

[0189] [Number 23]

K = iy _W + (5 _W + _{-ώ /} ) / 2 + Τ v _Wi .) ^ • (25)

(26) In the above embodiment, the function f (Y, k) and the function g (Y, 1) are exponential functions or positive r, J r, j

Although a chord function was used, the present invention is not limited to this, and any function can be applied as long as the function uses the Y position Y within the shot as an independent variable.

Further, in the correction function dy (Y, h) in the Y-axis direction in the above-described embodiment, only the position term including the linear function of the X position X in the shot is set to 1 of the X position X in the shot. A time term including the following function may be newly added. Further, the speed V included in the right side of Expressions (6), (7), (10), and (11) may be replaced with a function using the speed V as an independent variable.

r, J r'j

Further, a position term and a time term that do not include the velocity V may be added. That is, the function model of the correction function can be appropriately modified.

Further, the marks used in the low-speed / high-speed overlapping exposure of the above embodiment are not limited to the marks M as shown in FIG. For example, the L / S pattern MX, MY is just one L

1 1

It may be a / S pattern. Also, the LZS patterns MX, MX, MY,

1 2 1

In addition to MY, other LZS patterns and the results of box-in-box

2

It's okay to use a mark that contains a pattern that becomes a box 'pattern. Even with such a pattern, it is possible to detect the misalignment between the outer pattern and the inner pattern as a positional shift amount in the X-axis direction and the Y-axis direction. In addition, if a plurality of patterns for measuring the amount of misalignment are provided in one mark, a plurality of misalignments can be detected in each axis direction in one mark. Therefore, it is possible to improve the detection accuracy of the positional deviation amount by using the average value of the detected plural positional deviation amounts as the positional deviation amount at the mark. In the above embodiment, the coefficient C of each term of the correction function was obtained by applying the least squares method. However, if the nonlinearity of the function model with respect to the parameter to be obtained is high, the coefficient C may be obtained by applying a nonlinear least squares method such as the steepest descent method.

[0193] Further, in the above-described embodiment, the displacement amount in the X-axis direction and the Y-axis direction is detected using the alignment detection system AS. However, the present invention is not limited to this. It may be possible to detect the amount of positional deviation of.

[0194] << Method using reference wafer >>

In the above-described embodiment, the correction function is obtained by so-called low-speed / high-speed scanning exposure. However, the method of obtaining the transfer result for creating the correction function is not limited to this. For example, the same pattern as the pattern formed when the pattern formed on the reticle R is ideally transferred is formed on the surface of the wafer, that is, the reference position is the position corresponding to the mark on the reticle R. Scanning exposure is performed on the pattern under each scanning condition j using the “reference wafer” on which the mark is formed, and the existing reference mark on the reference wafer is scanned and exposed under each scanning condition j. In this case, the amount of positional deviation from the mark formed by the transfer may be obtained as information relating to the positional deviation of the transfer position of those marks. In this case, an offset can be added to the plus scan correction function. Equation (6) or (10) can be used as the plus scan correction function dx, and the plus scan correction function dy can be given by the equation Equation (7) or equation (11) can be used.

In the above embodiment, the measurement value of the reticle interferometer 16 is corrected, but the measurement value of the wafer interferometer 18 may be corrected. In this case, it goes without saying that the coordinate system corresponding to the correction function is a shot coordinate system in wafer conversion.

[0196] << Exclusion or smoothing of measurement data >>

In the above embodiment, in step 632 in FIG. 6, the mark image MP is formed under the low-speed running condition from the displacement amount (dx, dy) of each mark image MP formed under the different running conditions. By subtracting the displacements (dx, dy) of the respective mark images MP, the displacements (dx, dy) used for creating the correction function were detected. In this way, the reticle, which is originally irrelevant to shot distortion, forward / reverse This is because a manufacturing error can be eliminated.

As described above, in order to make the correction function created in the above embodiment highly accurate, the amount of misalignment caused only by the shot distortion and the forward / reverse difference is determined by the amount of misalignment related to the misalignment of the mark transfer position. It is desirable to detect it as information, regard the component due to other components as an error, and remove it from the amount of displacement. The errors included in the displacement amount in the above embodiment can be classified as follows from the nature thereof.

A. An error caused by a reticle, such as the reticle manufacturing error described above or an error caused by a foreign substance attached to the reticle, and often appears regularly.

B. Measurement error, so-called random error (probability error), which appears randomly according to a predetermined probability distribution

Regarding errors classified as A., as in the above-described embodiment, running exposure is performed under low-speed running conditions, and the positional deviation amount of the mark at that time is regarded as a reticle manufacturing error or the like. By performing some kind of measurement processing, such as measurement, the error can be removed from the measured displacement.However, even if the error is not actually measured, the error can be classified as A. Errors can be removed. On the other hand, it is difficult to actually measure errors classified as B. Therefore, in the following, another method for removing errors classified as A. and a method for removing errors classified as B. will be described.

[0200] «Other methods to remove errors classified as ΑΑ»

FIG. 11 is a flowchart illustrating an example of a process for implementing a method of removing an error classified as A. It is assumed that the processing of step 502 to step 534 in FIG. 5 and step 602 to step 630 in FIG.

S scanning exposures have been performed under different running conditions j, respectively.

The shot area formed by each scan exposure is referred to as a shot area s (s = ls), and the mark image MP formed in the shot end area s is referred to as a mark image MP. And the measured X axis

P P.s

Let the displacement amount in the direction and the Y-axis direction be (dx ', dy'), respectively. Also, show p, s p, s

Let (X, Y) be the design position coordinates of the mark image MP in the coordinate system within the unit, and mark images p, s p p

Let p be the number of MPs. These data are stored in a storage device (not shown) of the main storage device 20.

It is assumed that it is stored in advance. As shown in FIG. 11, first, in step 302, an allowable change amount d which is an allowable value of a change amount of a positional shift amount of a transfer position of a mark image between adjacent mark images is set. This allowable change amount d is input to main controller 20 via an input device (not shown). In the next step 304, the value of the counter p (hereinafter referred to as the counter value p) is initialized to 1. In the next step 306, the counter value p is determined by the number p of the mark images MP in one shot area.

p's end is greater or less ^ Judge. If this determination is affirmed, the process is terminated, and if denied, the process proceeds to step 308. Here, p = l, the result is negative, and the routine proceeds to step 308.

[0202] In step 308, the mark image MP (here, MP) in the shot area 11s is obtained.

end p, sls Calculates the average value (μ, μ) of the displacement amount (dx 'dy').

p, s p, s p, dx p, dy

Next, in step 310, the mark image MP is determined. The mark image MP is

XL XL

Assuming that the position coordinates of the accounting are (X, Υ), the current mark image MP (here, the mark image M

XL XL p s

P), the value of the designed Y-axis coordinate Y is the same (that is, Υ = Υ), and the mark image having the designed X coordinate X that satisfies the condition shown as l, sp X p in the following equation. And here, that

P

Is replaced with mark image MP (p = l

XL p, s — p).

end

[0204] [Equation 24] XL < _P and X _P -X _XL = mini X p-. One X q „■ (27) where q is p ≠ in 1, 2, ···, p q is an integer, that is, the mark image M

end

P is the nearest mark image on the X side of mark image MP. In addition,

XL p's

Mark image MP is at the end of shot area s, and there is no mark image MP that satisfies the above conditional expression

XL

There may be cases. In this case, assuming that there is no mark image MP, the processing in step 310 is performed.

XL

To end.

[0205] In this step 310, when there is a mark image MP satisfying the above conditional expression,

XL

In the shot area 11 s, the displacement amount dx ′ of the mark image MP in the X-axis direction

ena XL L, s Average value is calculated.

dx

[0206] Next, in step 312, the average amount of misalignment between the mark images MP and the mark images MP is calculated.

XL p s

The variation (gradient) Δ 均 of the average value is calculated using the following equation.

[0207] [Number 25] p _t dx L, • (28)

Next, in step 314, a mark image MP is determined. Mark image MP

X X

Assuming that the position coordinates are (X, Υ), this mark image MP (here, the mark image MP)

XR XR p, s l, s and the mark image MP and the design Y-axis coordinate Y value are the same and expressed by the following formula

P.s P

A mark image MP having a design X coordinate X that satisfies the condition.

P P.s

The mark image MP is selected from the mark images MP.

XR p, s

[0209] [Number 26]

X „X XR and X-X„-X

(29) where q is an integer such that p ≠ q among 1, 2, ···, p. That is, the mark image M

end

P is the nearest mark image on the + X side of the mark image MP. In addition,

XL p's

When the mark image MP is at the end of the shot area and there is no mark image MP that satisfies the above condition, p, s XR

It is possible. In this case, assuming that there is no mark image MP, step 314 is left as it is.

XR

Is completed.

[0210] In this step 314, when there is a mark image MP satisfying the above conditional expression,

XR

Calculate the average value μ of the displacement dx 'of the mark image MP in the X-axis direction.

XR R, s R, dx

[0211] Next, in step 316, the amount of displacement between the mark images MP and the mark images MP is changed.

p, s XR

The amount of change (gradient) Δ Χ is calculated using the following equation.

R

[0212] [Number 27]

• (30)

Χ χϋ 一^Λ ρ

[0213] In the next step 318, it is determined whether or not the product of Δ 上記 calculated in step 312 and ΔΧ calculated in step 314 is negative. If this judgment is affirmed,

R

Proceed to step 320; if not, proceed to step 324. The product of Δ Χ and Δ Χ is negative

R In other words, the average value of the displacement of the mark image MP in the X-axis direction is positive compared to the average value of the displacement of the mark images MP on both sides adjacent in the X-axis direction in the X-axis direction. It indicates that it protrudes in the direction or the negative direction. One of the mark images MP and MP

XL XR

If not, the process proceeds to step 320 without making this determination.

In step 320, it is determined whether ΔΧ> d or ΔΧ> d. Here,

L R

If Δ で has not been calculated in step 312, it is only determined whether Δ Χ> d.

R

If Δ Χ has not been calculated in step 314, only whether or not Δ Χ> d

R

To be judged. If this judgment is affirmed, the process proceeds to step 322, and if not, the process proceeds to step 324. Δ Χ> d or Δ Χ> d means that the mark image MP

R p, s

Variation force of the average value of the positional deviation amount Indicates that the average value of the positional deviation amount in the X-axis direction of the mark images on both sides adjacent in the X-axis direction is steep enough to exceed the allowable range d. .

[0215] That is, if the determination in step 318 is affirmative and the determination in step 320 is affirmative, step 322 is executed. In step 322, mark image MP and mark image MP

XL

Using the average value of the amount of misregistration with

XR p, s

The interpolation value of the amount is calculated, and the interpolation value is replaced with the average value of the displacement amount in the mark image MP.

[0216] [Number 28]

Υ-V ^{r /} one Χχι (31)

[0217] In the above steps 308-322, the average value of the displacement amount of the mark image MP in the X-axis direction was smoothed. In the subsequent steps 324-step 336, the mark image MP Smooths the average value of the displacement of the MP in the Y-axis direction. Each step

P.s

Since the specific processing is performed in the same manner as in step 308 and step 322 described above, detailed description will be omitted. For the amount of displacement in the X-axis direction, the gradient between mark images (MP, MP, MP) arranged in the X-axis direction is calculated, and the average is calculated based on the gradient.

XL p, s XR

Smoothing force The amount of misalignment in the Y-axis direction is Three mark images (MP

YL, MP

p, s, MP) based on the gradient between

Of course, it is necessary to perform lubrication.

[0218] If the determination is negative in step 332, or if the determination is negative in step 334, or if step 336 is completed, the process proceeds to step 338. In step 338, the counter value p is incremented by 1 (p-p + 1), and the process returns to step 306.

[0219] In step 306, it is determined whether or not the counter value p has exceeded p. Where p = 2 end

, And the determination is denied, and the routine proceeds to step 308. After that, for the mark image MP,

2

Step 308—The processing of step 322 smoothes the average value of the displacement in the X-axis direction, and the processing of step 324 and step 336 smoothes the average value of the displacement in the Y-axis direction Is done.

[0220] Thereafter, until the judgment is affirmed in step 306, that is, until the counter value p exceeds p, the mark image MP

3. Position in the X-axis direction and Y-axis direction with respect to MP, ... 4

The smoothing of the average value of the shift amount is performed.

[0221] If the determination in step 306 is affirmative, the process ends. In this way, if the processing shown in FIG. 11 described above is performed for each of the s shot areas for each of the scanning conditions j (j = l-N), the positional deviation of each shot area can be obtained. From the amount, systematic errors such as reticle manufacturing errors classified in A. above can be removed. In Steps 322 and 336, the average value of the mark image having a prominent average value with respect to the peripheral mark image is calculated by using the average value of the positional shift amount of the peripheral mark image by the above formula ( Although the value is replaced by the value calculated by the interpolation calculation of 31), the measurement data of the mark image may be excluded from the measurement data for creating the correction function. Also, some of the mark image misregistration amounts are set so that the average value of the mark image misregistration amounts is within an allowable range with respect to the average value of the peripheral mark image misregistration amounts. Alternatively, in step 634 of FIG. 6, the correction function may be excluded from the measurement data. In other words, when the average value of the amount of misregistration in the mark image MP of the shot area 11 s is used as the measurement data for creating the correction function, the average value is calculated as

P.s

If you don't use the excluded data, it's good.

[0222] Further, in the process shown in Fig. 11, the average value of the displacement amount of each mark is smoothed. As in the above embodiment, the scanning exposure is performed once for each of the scanning conditions 1 to N, one shot area is formed for each of the conditions, and the positional shift amount of each mark image in the shot area is set to the peripheral area. Needless to say, the smoothing may be performed in comparison with the positional deviation amount of the mark image.

[0223] << Other methods for removing errors classified as B. >>

FIG. 12 is a flowchart showing an example of processing for realizing a method for removing an error (accidental error such as a measurement error) classified as B. Also in this case, as a precondition, a plurality of (s) times of scanning exposures under different scanning conditions j on the wafer W are performed.

end

And the shot area formed by each scanning exposure is defined as a shot area s (s = ls). The mark image MP formed in the shot area s is replaced with the mark image M

end p

Let P be the measured displacement in the X-axis and Y-axis directions, respectively (dx'p, sp, s, dy '). Also, the design position coordinates of the mark image MP in the in-shot coordinate system are p, s p, s

(X, Y). These data are stored in a storage device (not shown) of the main storage device 20 in advance.

Ρ Ρ

It is assumed that

As shown in FIG. 12, first, in step 402, the values of the variance σ in the X-axis direction and the variance σ in the Υ-axis direction are set. Here, the variance σ σ

Υ X Υ

And is set in main controller 20. As the value of the variance σ σ,

X Υ

Exposure results obtained by multiple scanning exposures under scanning condition j, i.e., sample variance as a statistic obtained from measurement data of the amount of displacement in the X-axis direction and Y-axis direction of each mark image MP. Although it is desirable to set the values, if those values are known empirically, or if the value of the variance of the measurement error as the design value is known, the values may be set. good. When calculating the value of the sample variance from the measured data, it is desirable to exclude from the calculation any measurement data that is clearly deviated from the true value.

[0225] In the next step 404, the counter value p is initialized to 1. Then, in step 406, it is determined whether or not the counter value p is larger than p. In step 408, s mark images M

end end

The average value μ, μ p, s 1 dx ay of the displacement amount of P (here, MP) in the X-axis direction and the Y-axis direction is calculated. [0226] In the next step 410, the value of the counter s (hereinafter, referred to as the counter value s) is initialized to 1. Then, in a step 412, it is determined whether or not the counter value s is larger than s. This case end

If the disconnection is denied, proceed to step 414; if affirmative, proceed to step 424.

[0227] In step 414, the position of the mark image MP in the shot area s (here, 1) in the X-axis direction is not determined.

P

P's dx X is determined whether the amount dx is within ± 3σ of the mean μ.

I do. If this determination is denied, the process proceeds to step 416, and if affirmed, the process proceeds to step 418. In step 416, the displacement amount dx 'of the mark image MP is replaced with the average value / z, and p, sp, sdx is used.

[0228] In step 418, the position p, s of the mark image MP in the shot area s (here, 1) is not set in the Y axis direction.

P, s dY Y to determine whether the amount dy 'is within ± 3σ of the mean μ

I do. If this determination is denied, the process proceeds to step 420, and if affirmed, the process proceeds to step 422. In step 420, the displacement dy 'of the mark image MP is replaced with the average value.

P's p, s dy

[0229] At step 422, the counter value s is incremented by 1 (s s + 1), and the process returns to step 412.

In step 412, it is determined whether the counter value s is greater than s. Here, s = 2 and end

Therefore, the determination is denied, and the routine proceeds to step 414.

[0230] Thereafter, until the determination in step 412 is affirmed, in step 414 and step 422, the displacement amount dx of the mark image MP in the shot areas 2, 3, 4,.

1 l, s ,, dy '(s l, s

= 2, 3, 4, · · · ·).

[0231] If the determination is affirmative in step 412, the counter value p is incremented by 1 in step 424, and the process returns to step 406. At step 406, it is determined whether or not the counter value p is larger than p by end. Here, since p = 2, the determination is negative, and the routine proceeds to step 408.

[0232] Thereafter, in step 408 and step 422, the positional deviation amount dx in the mark image MP

2

', Dy' is smoothed. And if the judgment is affirmed in step 412,

P's p, s

Then, the process proceeds to step 424, where the counter value p is incremented by 1 (p-p + 1), and the process returns to step 406.

[0233] Thereafter, steps 406—step 424 The processing is repeatedly executed, and the order of the mark image MP in the shot area 11 s,.

4, s displacement amount (dx, dy,), (dx

4, s, dy '), ... are smoothed.

3's 3, s 4's

[0234] If the determination in step 406 is affirmative, the process ends. In this way, if the processing shown in FIG. 12 described above is performed for all running conditions, accidental errors such as measurement errors classified in B. above are removed from the positional deviation amounts of the shot areas. be able to. In Steps 416 and 420, the force obtained by replacing the displacement with the average value.Here, the displacement is excluded from the measurement data for creating the correction function in Step 634 in FIG. May be. That is, when the average value of the mark image MP in the shot area 11 s is used as the measurement data for creating the correction function, end p, s

, The excluded data should not be used for calculating the average value.

In the smoothing process as shown in FIG. 12, when the average value μ, a force of the displacement amount of the mark image MP in the running exposure under the running condition j is known, The sp, s dx dy

It is not necessary to form multiple shot areas. Assuming that s = 1, the above step 402—step end end

Step 424 is good.

[0236] It should be noted that the smoothing processing shown in FIGS. 11 and 12 is also effective in smoothing the measured values when a correction function is created using a reference wafer. Absent. Further, various smoothing processes other than the process shown in FIG. 12 can be applied. For example, it is possible to apply the statistical methods currently used in wafer alignment such as the EGA method and the rejection of sample marks to the above-mentioned positional deviation smoothing. In addition, it is of course possible to apply both the processes performed in FIGS. 11 and 12. For example, the smoothing shown in FIG. 11 can be performed on the measurement data on which the smoothing shown in FIG. 12 has been performed.

[0237] << Correction function for synchronization accuracy during scanning exposure >>

Further, in the above embodiment, the correction function for correcting the measurement value of the wafer interferometer 18 is created based on the exposure result of the actual scanning exposure (the displacement amount of the transfer position of each mark). However, based on the synchronization accuracy of both stages during scanning exposure, which is not based on such exposure results, a correction function for correcting the measurement value of the wafer interferometer 18 for the purpose of reducing the synchronization accuracy is provided. It can also be created. [0238] The synchronization accuracy of both stages is determined by the relative deviation of synchronous scanning during scanning exposure between wafer stage WST and reticle stage RST. The closer the relative deviation is to zero, the closer the synchronization accuracy becomes. Will be good. For example, as an index value of the synchronization accuracy of the two stages, the theoretical relative positional relationship between the reticle stage RST and the wafer stage WST during scanning exposure, the reticle interferometer 16 during scanning exposure, and the reticle stage WST during scanning exposure. The difference between the actual relative positional relationship between the two stages RST and WST calculated from the measured value of the interferometer 18 is used. This difference is, for example, ex and ey. Where i is

i i

Ex and ey are the sampling numbers during exposure, both stages during scanning exposure RST, WST i i

It is assumed that the sampling period coincides with the sampling period of the feedback control system.

[0239] Main controller 20 acquires ex and ey during the scanning exposure for each sampling cycle, and calculates the average moving time (so-called MEAN value) of ex and eyiiiii as information relating to synchronization accuracy. The moving averages are defined as dx and dy (in this case, p is

P, j P.j

As with the processing in step 634 in FIG. 6, if an optimization method such as the least squares method is performed, the above equations (6), (7), and (10) can be obtained. , The coefficient C of each term in equation (11) can be obtained. In this case, an offset can be added to the plus scan correction function, and equation (6) or (10) can be used as the plus scan correction function dx, and as the plus scan correction function dy, Equation (7) or Equation (11) can be used

[0240] Note that it is unlikely that this synchronization error includes a systematic error such as a reticle manufacturing error classified in the above A. Therefore, the smoothing process shown in FIG. Although it is not necessary to do so, it is quite possible that accidental errors such as measurement errors are included, so when creating a correction function for this synchronization error, the X-axis and Y-axis Can be applied to the measurement data smoothing process.

[0241] In other words, based on statistics such as the variance of the moving time average of the synchronization error corresponding to each of a plurality of sampling points during scanning exposure, a predetermined multiple of the standard deviation is performed in the same manner as the processing shown in Fig. 12. A part of the moving average of the synchronization error that is out of the range is excluded from the measurement data used for the correction function, or smoothed to the average of the moving average of the synchronization error at the same sampling point. Or you can. [0242] In the above embodiment, the FIA-type alignment sensor is used as the alignment detection system AS. However, as described above, the laser beam is applied to the dot-shaped alignment marks on the wafer W. , An LSA (Laser St Mark Alignment) type alignment sensor that detects the mark position using light diffracted or scattered by the mark, or an alignment sensor that appropriately combines the alignment sensor with the FIA method described above. It is also possible to apply the present invention. In addition, for example, an alignment sensor that irradiates a coherent detection light onto a mark on a surface to be detected and interferes with two diffracted lights (for example, the same order) generated from the mark can be used alone or in the FIA method described above. Of course, the present invention can be applied to an alignment sensor appropriately combined with the LSA method or the like.

[0243] The alignment detection system may be an on-axis system (for example, a TTL (Through The Lens) system). In addition, the alignment detection system is not limited to one that detects the alignment mark in a state where the alignment mark is almost stationary in the detection field of view of the alignment detection system, but detects the detection light emitted from the alignment detection system and the alignment mark. May be moved relative to each other (for example, the above-mentioned LSA system, homodyne LIA system, etc.). In the case of such a method in which the detection light and the alignment mark are relatively moved, it is desirable that the relative movement direction is the same as the movement direction of the wafer stage WST when detecting each of the above-mentioned alignment marks.

[0244] The projection optical system PL may be any of a refraction system, a catadioptric system, and a reflection system, and may be any of a reduction system, an equal magnification system, and an enlargement system.

Further, the light source of the exposure apparatus to which the present invention is applied may be a KrF excimer laser, an ArF excimer laser, a force S used as an F laser, or another pulsed laser light source in the vacuum ultraviolet region.

2

In addition, as illumination light for exposure, for example, a single-wavelength laser beam in the infrared or visible range oscillated from a DFB semiconductor laser or a fiber laser is doped with, for example, erbium (or both erbium and ytterbium). A harmonic that is amplified by a fiber amplifier and wavelength-converted to ultraviolet light using a nonlinear optical crystal may be used.

[0246] The illumination optical system, the projection optical system, and the alignment detection system AS, which are composed of a plurality of lenses, are incorporated into the exposure apparatus main body, and optical adjustment is performed. Attach the stage to the exposure tool body and connect wiring and piping The exposure apparatus according to the above embodiment can be manufactured by connecting them and further performing overall adjustment (electrical adjustment, operation confirmation, etc.). It is desirable to manufacture the exposure apparatus in a clean room in which the temperature, cleanliness, etc. are controlled.

[0247] The present invention is not limited to an exposure apparatus for manufacturing a semiconductor, but also includes an exposure apparatus for transferring a device pattern onto a glass plate and a method for manufacturing a thin film magnetic head, which are used for manufacturing a display including a liquid crystal display element and the like. It can also be applied to exposure equipment used for the manufacture of exposure devices that transfer device patterns used for lithography onto ceramic wafers, imaging devices (such as CCDs), organic ELs, micromachines, and DNA chips. In addition, glass substrates or silicon wafers are used to manufacture reticles or masks used in optical exposure equipment, EUV exposure equipment, X-ray exposure equipment, electron beam exposure equipment, etc. that can only be used with micro devices such as semiconductor devices. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern to a substrate. Here, a transmissive reticle is generally used in an exposure apparatus using DUV (far ultraviolet) light or VUV (vacuum ultraviolet) light, and quartz glass, fluorine-doped quartz glass, or firefly is used as a reticle substrate. Stone, magnesium fluoride, quartz or the like is used. In a proximity type X-ray exposure apparatus or an electron beam exposure apparatus, a transparent mask (stencil mask, membrane mask) is used, and a silicon wafer or the like is used as a mask substrate.

In addition, the present invention is not limited to an exposure apparatus, and mounts an object on a stage movable in a two-dimensional plane, and processes the object while moving the stage in a predetermined direction in the two-dimensional plane. The present invention can be applied to any device that applies the method.

[0249] << Device manufacturing method >>

Next, an embodiment of a device manufacturing method using the above-described exposure apparatus 100 in a lithographic process will be described.

FIG. 13 shows a flowchart of an example of manufacturing devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). As shown in FIG. 13, first, in step 801 (design step), the function of the device and the performance design (for example, the circuit design of a semiconductor device) are performed, and the pattern for realizing the function is designed. . Then, in step 802 (mask manufacturing step), the designed circuit A mask with a turn is manufactured. On the other hand, in step 803 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step 804 (wafer processing step), using the mask and wafer prepared in step 801—step 803, an actual circuit or the like is placed on the wafer by lithography technology or the like as described later. Form. Next, in step 805 (device assembly step), device assembly is performed using the wafer processed in step 804. Step 805 includes steps such as a dicing step, a bonding step, and a packaging step (chip sealing) as necessary.

[0252] Finally, in step 806 (detection step), inspections such as an operation confirmation test and an endurance test of the device created in step 805 are performed. After these steps, the device is completed and shipped.

FIG. 14 shows a detailed flow example of step 804 in the semiconductor device. In FIG. 14, in step 811 (oxidation step), the surface of the wafer is oxidized. Step 812 (CVD step) forms an insulating film on the wafer surface. Step 813 (electrode formation step) forms electrodes on the wafer by vapor deposition. In step 814 (ion implantation step), ions are implanted into the wafer. Each of the above steps 811 to 814 constitutes a pre-processing step of each stage of the wafer processing, and is selected and executed according to a necessary process in each stage.

[0254] In each stage of the wafer process, when the above-described pre-processing step is completed, a post-processing step is executed as follows. In this post-processing step, first, in step 815 (resist forming step), a photosensitive agent is applied to the wafer. Subsequently, in step 816 (exposure step), the circuit pattern of the mask is transferred to the wafer using the exposure apparatus 100 of the above embodiment. Next, in step 817 (development step), the exposed wafer is developed, and in step 818 (etching step), the exposed members other than the portion where the resist remains are removed by etching. Then, in step 819 (resist removing step), unnecessary resist after etching is removed.

[0255] By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the wafer. With the use of the device manufacturing method of the present embodiment described above, the exposure apparatus 100 of the above embodiment is used in the exposure step (step 816), so that it is possible to realize high-precision exposure. As a result, it becomes possible to produce a device with a higher degree of integration. Industrial applicability

[0257] The exposure apparatus and the exposure method of the present invention are suitable for a lithographic process for manufacturing a semiconductor element, a liquid crystal display element, and the like. Further, the device manufacturing method of the present invention is suitable for the production of micro devices.

Claims

The scope of the claims

[1] An exposure apparatus that performs scanning exposure for transferring a pattern formed on the mask onto the object via a projection optical system by synchronously moving the mask and the object in a predetermined direction with respect to illumination light. hand,

A transfer device for transferring a plurality of marks arranged on a mask onto an object under a plurality of different running conditions by the scanning exposure;

From the transfer result of the plurality of marks by the scanning exposure under each of the scanning conditions, information on the displacement of the transfer position of each mark on the object in a two-dimensional plane orthogonal to the optical axis of the projection optical system is obtained. An acquisition device for acquiring;

Based on the acquired information on the displacement of the transfer position of each mark and each of the running conditions, the scanning condition, the position and the position of the object in the two-dimensional plane are determined using an optimization method. A measurement value at any one of the positions of the mask in a plane substantially parallel to the two-dimensional plane; and a first term as an independent variable, and correction of the measurement value at the one of the positions. A function creation device for creating a correction function with the quantity as a dependent variable;

When the transfer device performs the scanning exposure under an arbitrary scanning condition to transfer the pattern onto an object, the transfer function uses the correction function to which the arbitrary scanning condition is substituted, and A control device that corrects the measured value at one of the positions and controls the position based on the corrected measured value.

[2] In the exposure apparatus according to claim 1,

The controller is configured to correct one of the one or more positions under the plurality of different scanning conditions based on the measured value of the one of the positions corrected using the correction function in which the respective scanning conditions are substituted. As a result of performing the scanning exposure by the transfer device and transferring each mark onto the object in a state where the position is controlled, information on a positional shift of a transfer position of each mark acquired by the acquisition device as a result of transferring each mark onto the object. A function correcting device that repeats a process of correcting the correction function using the optimization method based on each of the scanning conditions until a predetermined condition is satisfied;

The controller is Controlling one of the positions by using a corrected correction function.

[3] In the exposure apparatus according to claim 2,

The predetermined condition is:

An exposure apparatus, wherein a magnitude of a positional shift of a transfer position of each mark is equal to or less than a predetermined amount.

[4] The exposure apparatus according to claim 1,

The transfer device,

A plurality of reference marks formed at positions corresponding to the respective marks on the mask are formed in advance, and the scanning exposure is performed using an object.

The acquisition device,

An exposure apparatus, wherein a deviation between a position of each of the reference marks and a transfer position of each of the marks is acquired as information on a positional deviation of a transfer position of each of the marks.

[5] In the exposure apparatus according to claim 1,

The transfer device,

The plurality of marks are further transferred onto the object by scanning exposure under predetermined scanning conditions,

The acquisition device,

Information on the displacement of the transfer position of each mark due to scanning exposure under each of the different scanning conditions with reference to the transfer position of each mark on the mask due to scanning exposure under the predetermined scanning condition. An exposure apparatus characterized in that an exposure is obtained.

[6] The exposure apparatus according to claim 5,

The plurality of different running conditions include the same running condition as the predetermined running condition,

The acquisition device,

The displacement amount between the transfer position of each mark by running exposure under the different running conditions and the transfer position of each mark by running exposure under the predetermined running conditions is the same. The transfer position of each mark by running exposure under running conditions of An exposure apparatus, wherein an amount obtained by subtracting the amount of displacement from the transfer position of each mark due to scanning exposure under predetermined scanning conditions is acquired as information relating to the displacement of the transfer position of each mark. .

[7] The exposure apparatus according to claim 1,

The acquisition device,

Based on a change in the value of the information on the displacement of the transfer positions of the plurality of marks obtained between the marks, a part of the information on the displacement of the transfer positions of the plurality of marks is excluded or smoothed. An exposure apparatus, comprising:

[8] The exposure apparatus according to claim 7,

Value of the information about the displacement of the transfer position If there is a mark protruding by a predetermined degree or more with respect to the value of the information about the displacement of the transfer position of the surrounding mark, the information about the transfer position of the mark is given. An exposure apparatus that excludes the acquired information from the information on the positional shift of the transfer position of each of the marks.

[9] The exposure apparatus according to claim 7,

The value of the information about the positional deviation of the transfer position If there is a mark that protrudes by a predetermined degree or more from the value of the information about the positional deviation of the transfer position of the surrounding mark, the positional deviation of the transfer position of the mark An exposure apparatus that replaces a value of the information on the position information with a value calculated by a predetermined interpolation operation using the information on the displacement of the transfer position of the peripheral mark.

[10] The exposure apparatus according to claim 1,

The acquisition device,

An exposure apparatus comprising: removing or smoothing a part of information relating to a positional shift of a transfer position of each mark based on a statistic regarding a positional shift of each mark under the same scanning condition.

[11] The exposure apparatus according to claim 10, wherein

The statistic is a variance of a value of information on a displacement of a transfer position of each mark under the same scanning condition,

The acquisition device, If there is a mark in which the value of the information about the displacement of the transfer position is out of the predetermined range based on the variance, the information about the displacement of the transfer position of the mark is transferred to the transfer of the mark acquired above. An exposure apparatus characterized in that it is excluded from information on positional displacement.

[12] The exposure apparatus according to claim 10,

The acquisition device,

In the case where there is a mark in which the value of the information about the displacement of the transfer position is outside the predetermined range based on the dispersion, the value of the information about the displacement of the transfer position of the mark is changed under the same running condition. Characterized in that the information is replaced with an average value of information on a positional shift of a transfer position of a mark obtained in each of a plurality of scanning exposures.

[13] The exposure apparatus according to claim 1, wherein

The exposure apparatus according to claim 1, wherein the first term is a power function that uses a measured value of the position of the object as an independent variable.

[14] The exposure apparatus according to claim 1,

The scanning conditions are:

An exposure apparatus comprising at least one of a scan length and a scan speed.

[15] The exposure apparatus according to claim 1, wherein

The scanning conditions are:

An exposure apparatus comprising a scanning direction.

[16] The exposure apparatus according to claim 1, wherein

The exposure apparatus, wherein the correction function further includes a second term in which time during the scanning exposure is an independent variable.

[17] The exposure apparatus according to claim 16, wherein

The exposure apparatus according to claim 2, wherein the second term is at least one of a sine function and an exponential function using the measured value of the position of the object as an independent variable.

[18] The exposure apparatus according to claim 1,

The correction function includes:

A correction function using the correction amount of the measured value of the position of the object in the scanning direction as an objective function, and a correction amount of the measured value of the position of the object in a direction orthogonal to the running direction in the two-dimensional plane. There is a correction function as an objective function,

The correction function using the correction amount of the position of the object in the scanning direction as an objective function further includes a third term including a linear function using a measured value of the position of the object in the scanning direction as an independent variable. An exposure apparatus, comprising:

[19] The exposure apparatus according to claim 1,

An exposure apparatus, wherein the optimization method is a least squares method.

[20] The exposure apparatus according to claim 1,

An exposure apparatus, wherein the optimization method is a nonlinear least squares method.

[21] An exposure method for performing a scanning exposure in which a pattern formed on the mask is transferred onto the object via a projection optical system by synchronously scanning the mask and the object in a predetermined direction with respect to illumination light. ,

An exposure method, comprising: performing scanning exposure using the exposure apparatus according to claim 1, and transferring a pattern on the mask to the object.

[22] An exposure apparatus that performs scanning exposure for transferring a pattern formed on the mask onto the object via a projection optical system by synchronously scanning the mask and the object in a predetermined direction with respect to illumination light. ,

A transfer device for transferring the pattern formed on the mask onto the object under a plurality of different scanning conditions by the scanning exposure;

An acquisition device for acquiring information on synchronization accuracy between the mask and the object during running exposure under each of the running conditions;

Based on the acquired information on the synchronization accuracy and each of the scanning conditions, using an optimization method, the running condition, the position of the object in the two-dimensional plane, and substantially parallel to the two-dimensional plane. Correction of the measurement value at one of the positions of the mask at least including the first term as an independent variable with the measurement value at one of the positions of the mask in a simple plane A function creation device for creating a correction function having a quantity as a dependent variable;

When the transfer device performs the scanning exposure under an arbitrary scanning condition to transfer the pattern onto an object, the transfer device uses the correction function to which the arbitrary scanning condition is substituted, and uses the correction function. A control device that corrects the measured value of the position, and controls one of the position and the deviation based on the corrected measured value.

[23] The exposure apparatus according to claim 22, wherein

The controller is configured to correct one of the one or more positions under the plurality of different scanning conditions based on the measured value of the one of the positions corrected using the correction function in which the respective scanning conditions are substituted. While the position is controlled, during the scanning exposure under the scanning conditions by the transfer device, information on synchronization accuracy between the mask and the object acquired by the acquisition device, the scanning conditions, and A function correcting device that repeats a process of correcting the correction function using the optimization method based on the above until a predetermined condition is satisfied,

The control device includes:

An exposure apparatus using a corrected correction function.

[24] The exposure apparatus according to claim 22, wherein

The transfer device,

An exposure apparatus, wherein an average of a moving time of synchronization accuracy between the mask and the object during the scanning exposure is acquired as the information on the synchronization accuracy.

[25] The exposure apparatus according to claim 22, wherein

The information on the synchronization accuracy is:

An exposure apparatus including an error in synchronous scanning between the mask and the object.

[26] The exposure apparatus according to claim 22, wherein

The acquisition device,

A part of the acquired information on the synchronization accuracy is excluded or smoothed based on statistics of the information on the synchronization accuracy respectively corresponding to a plurality of sampling points during the scanning exposure. Exposure equipment.

[27] The exposure apparatus according to claim 26,

The statistic is a variance of information values regarding synchronization accuracy at each of the sampling times under the same scanning condition,

The acquisition device,

An exposure apparatus, wherein information relating to synchronization accuracy at a sampling time point at which a value outside a predetermined range based on the variance is excluded from the acquired information relating to synchronization accuracy.

[28] The exposure apparatus according to claim 26,

The statistic is a variance of a value of information on synchronization accuracy at each sampling time under the same running condition,

The acquisition device,

The value of the information on the synchronization accuracy outside the predetermined range based on the variance is replaced with the average value of the information on the synchronization accuracy at the same sampling point respectively obtained in the plurality of scanning exposures under the same scanning condition. An exposure apparatus comprising:

[29] The exposure apparatus according to claim 22, wherein

[30] The exposure apparatus according to claim 22, wherein

The scanning conditions are:

[31] The exposure apparatus according to claim 22, wherein

The scanning conditions are:

An exposure apparatus comprising a scanning direction.

[32] The exposure apparatus according to claim 22, wherein

[33] The exposure apparatus according to claim 32,

[34] The exposure apparatus according to claim 22, wherein

The correction function includes:

[35] The exposure apparatus according to claim 22, wherein

[36] The exposure apparatus according to claim 22, wherein

[37] An exposure method for performing scanning exposure in which a pattern formed on the mask is transferred onto the object via a projection optical system by synchronously scanning the mask and the object in a predetermined direction with illumination light. ,

23. An exposure method, comprising performing scanning exposure using the exposure apparatus according to claim 22, and transferring a pattern on the mask to the object.

[38] In a device manufacturing method including a lithographic process,

38. A device manufacturing method, wherein in the lithographic process, exposure is performed using the exposure method according to claim 21.