JP2002280288A - Reference wafer for calibration, method of calibration, method and device for detecting position, and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calibrate position detector with accuracy. SOLUTION: The image of a reference wafer SW for calibration, on which first reference marks (FSMa, FSMb and FSMc) including first marks (FTMa, FTMb and FTMc) having plural configuration feature points and second marks (STMa, STMb and STMc) for specifying the positions of the configurational feature points in the first marks (FTMa to FTMc) are formed is photographed with an imaging device which calibrates the position detector. Then the image magnification of the imaging device, the rotation amount of the imaging visual field of the device, center position of the visual field, etc., are calibrated with accuracy, by detecting the positions of a plurality of configurational feature points specified in the first marks (FTMa to FTMc) by means of the second marks (STMa to STMc).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration reference wafer, a calibration method, a position detecting method, a position detecting device, and an exposure device, and more particularly, to a position detecting method and a position detecting device for accurately detecting a position of a wafer. The present invention relates to a detection apparatus, a calibration method for the position detection apparatus, a calibration reference wafer used in the calibration method, and an exposure apparatus including the position detection apparatus.

[0002]

2. Description of the Related Art Conventionally, in a lithography 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 resisted through a projection optical system. There is used an exposure apparatus that transfers an image onto a substrate such as a wafer or a glass plate (hereinafter, referred to as a “substrate or wafer” as appropriate) coated with a substrate. As such an exposure apparatus, a stationary exposure type projection exposure apparatus such as a so-called stepper and a scanning exposure type projection exposure apparatus such as a so-called scanning stepper are mainly used. In such an exposure apparatus, it is necessary to perform high-precision alignment (alignment) between the reticle and the wafer prior to exposure.

For this reason, a highly accurate detection (detail (fine) alignment) of the positional relationship between a reference coordinate system defining the movement of the wafer and an array coordinate system (wafer coordinate system) relating to the arrangement of shot areas on the wafer is performed. For this purpose, several fine alignment marks (detailed alignment marks transferred together with the circuit pattern) in the wafer are measured. Then, after obtaining the array coordinates of each shot area by least squares approximation or the like, at the time of exposure, the calculation result is used,
Enhanced Global Alignment (hereinafter referred to as “EG”) that performs stepping depending on the accuracy of the wafer stage
A ”) is widely used.

For such EGA, it is necessary to observe a fine alignment mark formed at a predetermined position on a wafer at a high magnification.
The observation field of view is necessarily narrow. Therefore, in order to reliably capture the fine alignment mark in a narrow observation field of view, prior to fine alignment,
The positional relationship between the reference coordinate system and the array coordinate system is detected. When performing so-called search (rough) alignment before fine alignment, the positional relationship between the reference coordinate system and the array coordinate system is detected prior to the search alignment in order to capture the search mark in the observation field. Will be

First, the shape of the outer edge of a wafer to be subjected to position detection is observed. Then, the positional relationship between the reference coordinate system and the array coordinate system is detected with a predetermined accuracy based on the observed notch or orientation flat position of the wafer outer edge, the position of the wafer outer edge, or the like. This detection is hereinafter referred to as “pre-alignment”. Since a wafer used for manufacturing a semiconductor device is almost circular, three wafers necessary for defining a circular equation are used.
At least three outer edge positions necessary for deriving two parameters (two-dimensional position and radius of the center) are detected.

In such pre-alignment,
It is common practice to image the outer edge positions of at least three wafers and perform image processing to detect the outer edge positions of the wafer. However, in order to perform accurate position detection, it is used for imaging. It is necessary to accurately calibrate the imaging characteristics of an imaging device such as a CCD camera. That is,
Before imaging the wafer to be exposed, the magnification (X
(Direction magnification and Y direction magnification), the amount of rotation of the imaging visual field, and the center position of the imaging visual field must be accurately calibrated.

Conventionally, when performing imaging for pre-alignment, it is mounted on a vertically movable and rotatable center table provided on a stage whose position is detected very accurately by a laser interferometer or the like. It was common to image a wafer. For this reason, using the resources of position detection in pre-alignment, the center of rotation of the rotary table and the relationship between the amount of rotation and the amount of rotation measured by the rotation sensor are also calibrated.

FIG. 20A shows an example of a configuration conventionally used for performing the above-described calibration.
As shown in FIG. 20A, a laser interferometer IFX for measuring the X position and a laser interferometer IF for measuring the Y position
Wafer WST whose XY position is accurately detected by Y
The tool wafer JW held on the center table CT of the upper wafer holder WHL is imaged by CCD cameras 40a, 40b, and 40c as imaging devices. These CCD cameras 40a, 40b, 40c are arranged so as to image three outer edges of the tool wafer JW for calibration, and marks JMa, The position of the tool wafer JW is adjusted so that JMb and JMc enter. here,
As the marks JMa, JMb, and JMc, for example, FIG.
A so-called cross mark formed by arranging two rectangular patterns in the diagonal direction, as shown in FIG.

Then, by driving wafer stage WST in the XY directions, the position of the center position of each of cross marks JMa, JMb, JMc in the field of view is determined while moving tool wafer JW in the XY directions. The magnification of the CCD cameras 40a, 40b, 40c (X
(Direction magnification and Y direction magnification), the rotation amount of the imaging visual field, and the center position of the imaging visual field were calibrated. In addition, the center table CT is rotated within a range where the cross marks JMa, JMb, and JMc fall within the imaging field of view. At that time, the measurement result of the rotation amount by, for example, a rotary encoder, and the cross mark JMa by the CCD cameras 40a, 40b, and 40c. ,
Based on the detection results of the center positions of JMb and JMc, the relationship between the actual rotation amount and the rotation measurement amount of the rotation sensor, that is, the so-called rotation rate is calibrated.
The relationship between the XY position of wafer stage WST and the center of the rotational position of center table CT has been determined based on the detection result of the center position of cross marks JMa, JMb, and JMc.

[0010]

In the conventional calibration method described above, the calibration accuracy depends on the position detection accuracy of the wafer stage that moves integrally with the tool wafer. Therefore, high-precision calibration by the conventional calibration method is based on the precondition that a tool wafer is mounted on the center table of a wafer holder on a wafer stage whose position is detected by a high-precision position detection device such as a laser interferometer. .

When a vertically movable center table is provided on the wafer holder, the flatness of the surface of the wafer holder is inevitably reduced. In addition, when the center table is provided, the vertical movement mechanism of the center table needs to be housed inside the wafer holder, so that the size of the wafer holder is increased.

Further, if the procedure of performing pre-alignment after loading the wafer on the center table of the wafer holder on the wafer stage as in the prior art is as follows: wafer exchange → pre-alignment → [search (rough) alignment]
→ Fine alignment → Exposure was performed sequentially. As a result, the time required for processing one wafer was determined as wafer exchange time + pre-alignment time + [search (rough) alignment time +] fine alignment time + exposure time.

Therefore, in order to improve the throughput of the wafer processing, it is conceivable to perform the wafer alignment or the like and the pre-alignment in parallel. In such a case, the pre-alignment is performed without loading the wafer on the wafer stage. Need to be done. As a result, the conventional method for calibrating the pre-alignment apparatus that depends on the position measurement accuracy of the wafer stage cannot be adopted.

For this reason, a new technique for calibrating the imaging characteristics of the imaging device for pre-alignment and the rotation characteristics of the wafer support arm without relying on the position measurement accuracy of the wafer stage is now desired. .

The present invention has been made under the above circumstances, and a first object of the present invention is to provide a calibration reference wafer which can be used for accurate calibration of a wafer position detecting device. It is in.

A second object of the present invention is to provide a calibration method capable of accurately configuring a wafer position detecting device.

A third object of the present invention is to provide a position detecting method and a position detecting device capable of detecting a position of a wafer with high accuracy.

A fourth object of the present invention is to provide an exposure apparatus capable of transferring a predetermined pattern onto a substrate surface with high accuracy.

[0019]

According to the present invention, there is provided a calibration reference wafer, comprising: a position detecting device for detecting position information of a wafer (W) based on an imaging result of three or more imaging target areas near an outer edge of the wafer (W). A calibration reference wafer (SW) used for the calibration of
The first fiducial mark is formed of a substrate on which first fiducial marks (FSMa, FSMb, and FSMc) are formed, and each of the first fiducial marks has shape feature points arranged at a predetermined distance in each of two directions intersecting each other. A calibration reference wafer including a first mark (FTMa, FTMb, FTMc) and a second mark (STM) for specifying a position of each of the shape characteristic points in the first mark. . Here, in the “calibration”, in addition to adjusting the imaging characteristics and the like of the position detecting device to desired characteristic values, the characteristics of the position detecting device are stored, and various characteristics are taken with respect to the imaging result in consideration of the characteristics. This includes performing the processing to obtain the same result as the position detection result of the desired characteristic value by the position detection device. In this specification, the term “calibration” is used in this sense.

Each of the first reference marks on the calibration reference wafer is imaged by a corresponding imaging device, and in each of the imaging results, the positions of a plurality of shape feature points whose positions in the first mark are specified by the second marks. Is detected, the imaging magnification of each imaging device, the amount of rotation of the imaging visual field, the center position of the imaging visual field, etc.
Calibration according to the mark drawing accuracy can be performed.

For example, the imaging magnification of the imaging device can be calibrated based on the positional relationship between a plurality of shape feature points in the first mark in the imaging field of view. Further, the rotation amount of the imaging field of view can be calibrated based on the rotation amount of the first mark with respect to the imaging field of view obtained from the arrangement direction of the plurality of shape feature points in the first mark in the imaging field of view.
Further, based on the positions of a plurality of shape feature points in the first mark in the imaging field of view, the imaging magnification, and the amount of rotation of the imaging field of view, calibrating the center position of the imaging field of view in the coordinate system that defines the movement position of the wafer. Can be.

In the calibration reference wafer of the present invention, the first
The mark may be a mark in which a plurality of rectangular patterns are arranged in a checkered pattern.

In the calibration reference wafer according to the present invention, the first reference mark is a third reference mark for specifying a relationship between an imaging visual field position and the substrate when the second mark is outside the imaging visual field. Marks (TTM1, TTM2, TTM3) can be further included.

Further, in the calibration reference wafer of the present invention, the second reference marks (SSMa, SSMb, SS) serving as references for measuring the rotation amount around the central axis of the substrate are provided on the surface of the substrate.
Mc, SSMd) can be further formed.

The calibration method according to the present invention is arranged in accordance with each of three or more imaging target areas near the outer edge of the wafer (W) supported by the supporting device (36) rotatable about the normal to the wafer supporting surface. 3 or more imaging devices (40
a, 40b, 40c), a method of calibrating a position detecting device for detecting position information of the wafer based on the imaging result, wherein the calibration reference wafer (SW) of the present invention supported by the supporting device is A reference wafer position that is imaged by the imaging device and that adjusts the position of the calibration reference wafer based on the imaging result so that the first mark and the second mark fall within the corresponding visual field of the imaging device. Adjusting an at least one of the imaging device and the support device based on an imaging result of the first mark and the second mark on the calibration reference wafer whose position has been adjusted in the reference wafer position adjusting step. A calibration step.

According to this, in the reference wafer position adjusting step, the first mark and the second mark of the respective first reference marks on the calibration reference wafer of the present invention supported by the supporting device correspond to the imaging device. The position of the calibration reference wafer is adjusted so as to be within the imaging field of view. Here, as the position adjustment method, it is possible to adopt (a) manually placing the calibration reference wafer on the support device, and (b) two-dimensionally moving the calibration reference wafer by rotating the support device or the like. . Then, in the calibration step, at least one of the imaging device and the support device is calibrated based on the imaging results of the first mark and the second mark.

Therefore, calibration of the imaging device and the supporting device can be performed with high accuracy.

In the calibration method according to the present invention, when the calibration reference wafer is further formed with a second reference mark serving as a reference for the amount of rotation of the calibration reference wafer around the central axis, the calibration step Observing the second reference mark of the calibration reference wafer whose position has been adjusted in the reference wafer position adjustment step, measuring the amount of rotation of the calibration reference wafer around the central axis, and measuring the rotation amount with the calibration reference wafer. The imaging device and the support device can be calibrated based on imaging results of the first mark and the second mark with respect to a reference wafer.

In the calibration method according to the present invention, the calibration of the imaging device may include at least one of an imaging magnification, an amount of rotation of an imaging visual field, and a center position of the imaging visual field in the imaging device. In the calibration method of the present invention, the calibration of the support device may include at least one of a relationship between a measured rotation amount and an actual rotation amount and a rotation center position of the support device.

In the calibration method of the present invention, in the reference wafer position adjusting step, the translation of the translation reference position of the calibration reference wafer along a plane substantially parallel to the surface of the calibration reference wafer is performed by the support device. The stage device (WST, 18), which receives the calibration reference wafer from the above, can adjust the rotational position of the calibration reference wafer around the central axis by the support device.

Here, in the calibrating step, a correction relating to a positional shift of the calibration reference wafer that may occur when the calibration reference wafer is transferred between the stage device and the support device is performed. Can be.

Further, in the calibration method of the present invention, prior to the reference wafer position adjusting step, a field-of-view adjustment mark is formed in each of the imaging target areas, and the tool wafer supported by the support device is moved by the imaging device. The method may further include a field-of-view region position adjusting step of taking an image and adjusting the position of the field of view of the image pickup device based on the image pickup result.

The position detecting method according to the present invention is arranged in accordance with each of three or more imaging target areas near the outer edge of a wafer (W) supported by a support device (36) rotatable around a normal line of the wafer supporting surface. Three or more imaging devices (4
0a, 40b, 40c), a position detecting method for detecting position information of the wafer based on the imaging result,
An apparatus calibration step of calibrating the imaging apparatus and the supporting apparatus by the calibration method of the present invention; a wafer supporting step of supporting the wafer by the supporting apparatus; and imaging the wafer supported by the supporting apparatus. A position detection method including: a wafer imaging step of capturing an image by an apparatus; and a wafer position information detection step of obtaining position information of the wafer based on an imaging result in the wafer imaging step.

According to this, the support device and the imaging device are calibrated in the device calibration step. Subsequently, in the wafer support step, after the wafer whose position is to be measured is supported by the calibrated support device, in the wafer imaging step,
The wafer is imaged by the calibrated imaging device.
Then, in the wafer position information detecting step, the position information of the wafer is obtained based on the image pickup result by the calibrated image pickup device. Therefore, the position information of the wafer (for example, the center position of the wafer) is accurately detected based on the imaging result of the accurately calibrated imaging device of the wafer supported by the precisely calibrated support device.

The position detecting device according to the present invention is a position detecting device for detecting the position of the wafer (W) on the basis of the results of imaging of three or more imaging target areas near the outer edge of the wafer (W). A support device (36) rotatable around a normal line of the wafer support surface; and three or more imaging devices arranged in accordance with the three or more imaging target regions near the outer edge of the wafer supported by the support device, respectively. Devices (40a, 40b, 40c); a field-of-view region position adjusting device for adjusting the position of the field of view of the image pickup device; A calibration device (53, 54) for calibrating the imaging device and the supporting device based on the calibration device;
It is a position detection device provided with.

According to this, an image of the calibration reference wafer of the present invention supported by the support device is taken using the image pickup device whose view position has been adjusted by the view region position adjusting device. The calibration device calibrates the imaging device and the support device based on the imaging result. That is, the imaging device and the supporting device are accurately calibrated by the calibration method of the present invention.

Then, the wafer for position information detection supported by the calibrated supporting device is imaged by the calibrated imaging device, and the position information of the wafer is detected based on the imaged result. That is, the position information of the wafer is detected by the position detection method of the present invention. Therefore, the position information of the position information detection target wafer can be accurately detected.

In the position detecting device of the present invention, the calibration device is calibrated by the calibration reference wafer position adjustment device (53) for adjusting the position of the calibration reference wafer; A calibration amount calculation device (54) for calculating a calibration amount for the imaging device and the supporting device based on an imaging result of the calibration reference wafer by the imaging device.

Here, when a second reference mark for measuring the amount of rotation of the calibration reference wafer around the central axis is further formed on the calibration reference wafer, the calibration device performs the calibration for the calibration reference wafer. The apparatus may further include a rotation amount measuring device that observes the second reference mark on the reference wafer and measures a rotation amount of the calibration reference wafer around a central axis.

An exposure apparatus according to the present invention is an exposure apparatus that irradiates an exposure beam onto a substrate to form a predetermined pattern on the substrate, and the position detection apparatus according to the present invention detects position information of the substrate. A stage device (WST, 18) having a stage (WST) on which the substrate whose position information has been detected by the position detection device is provided.

According to this, the substrate whose position has been measured with high accuracy by the position detecting device of the present invention is mounted on the stage of the stage device. As a result, the position of the substrate can be controlled with high accuracy, and the pattern can be transferred onto the substrate with high accuracy.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG.

FIG. 1 shows the configuration of an exposure apparatus 100 including a substrate transfer apparatus according to one embodiment. The exposure apparatus 100 is a step-and-scan type scanning projection exposure apparatus (a so-called scanning stepper).

The exposure apparatus 100 includes an illumination system 12 including an exposure light source, and a reticle stage RS for holding a reticle R.
T, a projection optical system PL, a wafer stage WST as a stage on which a wafer W as a substrate is mounted, and a control system therefor.

The illumination system 12 includes an exposure light source and an illumination optical system (neither is shown). The illumination optical system includes an illuminance uniforming optical system including a collimator lens, an optical integrator such as a fly-eye lens or a rod-type integrator, a relay lens, a variable ND filter, a reticle blind, a relay lens, and the like.

Here, the components of the illumination system will be described together with their operation. Illumination light IL generated by the exposure light source has a substantially uniform illuminance distribution with a uniform illuminance distribution optical system and a variable ND filter for controlling the illuminance. Is converted into a light flux having the illuminance of As the illumination light IL, for example, Kr
Excimer laser light such as F excimer laser light or ArF excimer laser light, F ₂ laser light (wavelength 157 nm), Ar ₂
Dimer laser such as dimer laser, copper vapor laser and Y
A harmonic line of an AG laser or a bright line (g line, i line, or the like) in an ultraviolet region from an ultra-high pressure mercury lamp is used.

The light beam emitted from the illumination uniforming optical system is
Reach the reticle blind via the relay lens.
The reticle blind is disposed on a surface optically conjugate with the pattern forming surface of the reticle R and the exposure surface of the wafer W.

The reticle blind adjusts the size of the opening (slit width and the like) by opening and closing a plurality of movable light shielding plates (for example, two L-shaped movable light shielding plates) by, for example, a motor. The slit-shaped illumination area IAR (see FIG. 1) for illuminating R can be set to any shape and size.

Here, the above-mentioned respective driving units in the illumination system, that is, the variable ND filter, the reticle blind, and the like are controlled by the illumination controller (exposure controller) 14 in accordance with an instruction from the main controller 20.

The reticle stage RST is arranged on a reticle base board 13 and has a reticle R on its upper surface.
Are fixed, for example, by vacuum suction. Here, reticle stage RST is driven by an optical axis of an illumination optical system (an optical axis of a projection optical system PL to be described later) for positioning of reticle R by a reticle stage driving unit (not shown) composed of a magnetic levitation type two-dimensional linear actuator. AX) (in the X-axis direction)
It is possible to drive minutely (in the direction of rotation about the Z-axis orthogonal to the Y-axis direction and the XY plane orthogonal to this direction) and to drive at a scanning speed designated in a predetermined scanning direction (here, Y-direction). Has become. This reticle stage RS
T has a movement stroke in the Y direction that allows the entire surface of the reticle R to cross at least the optical axis of the illumination optical system.

The side surface of the reticle stage RST is mirror-finished and has a reflection surface for reflecting an interferometer beam from a reticle laser interferometer (hereinafter, referred to as a “reticle interferometer”) 16. The reticle interferometer 16 causes the return light from the reflection surface and the return light from a reference unit (not shown) to interfere with each other based on a photoelectric conversion signal of the interference light.
The position in the stage movement plane of the reticle stage RST is
For example, it is always detected with a resolution of about 0.5 to 1 nm.

The position information of the reticle stage RST from the reticle interferometer 16 is sent to the stage controller 19 and to the main controller 20 via the same, and the stage controller 19
Then, in response to an instruction from main controller 20, reticle stage RST is driven via a reticle stage driving unit (not shown) based on position information of reticle stage RST.

Since the initial position of reticle stage RST is determined so that reticle R is accurately positioned at a predetermined reference position by a reticle alignment system (not shown), the position of the reflecting surface is determined by reticle interferometer 16. It is possible to control the position of the reticle R with sufficiently high accuracy only by measuring.

The projection optical system PL is disposed below the reticle stage RST in FIG. 1, and is held on a main body column (not shown) via a holding member (not shown). The optical axis AX of this projection optical system PL (coincides with the optical axis of the illumination optical system)
Is a Z-axis direction. Here, a refractive optical system including a plurality of lens elements arranged at predetermined intervals along the optical axis AX direction so as to have a telecentric optical arrangement on both sides is used. The projection optical system PL is a reduction optical system having a predetermined projection magnification, for example, 1/4, 1/5, or 1/6.

For this reason, when the illumination area IAR of the reticle R is illuminated by the illumination light IL from the illumination system 12, the illumination light IL passing through the reticle R causes the illumination area IAR to pass through the projection optical system PL. A reduced image (partially inverted image) of the circuit pattern of reticle R is formed on wafer W having a surface coated with a resist (photosensitive agent).

The wafer stage WST includes a wafer base board 1 disposed below the projection optical system PL in FIG.
7, and a wafer holder 18 as a substrate holding member is mounted on wafer stage WST. A wafer W having a diameter of 12 inches is vacuum-sucked on the wafer holder 18. The wafer holder 18 is moved by a driving unit (not shown) with respect to the best image forming plane of the projection optical system PL.
Optical axis AX of projection optical system PL that can be tilted in any direction
It is configured to be finely movable in the direction (Z direction). The wafer holder 18 is also capable of rotating around the Z axis. The wafer stage WST and the wafer holder 18 constitute a wafer stage device as a stage device.

The wafer stage WST moves not only in the scanning direction (Y direction) but also in the scanning direction so that a plurality of shot areas on the wafer W can be positioned in the exposure area IA conjugate with the illumination area IAR. It is configured to be movable also in a vertical non-scanning direction (X direction), and performs scanning (scanning) exposure of each shot area on the wafer W as described later, and scanning for exposing the next shot. A step-and-scan operation of repeating the operation of moving to the start position is performed.

Here, the wafer stage WST is moved in the X-axis and Y-axis directions by a wafer driving device 15 as a stage driving device composed of a magnetic levitation type two-dimensional linear actuator.
It is driven in the two-dimensional direction of the shaft. The wafer driving device 1
Reference numeral 5 is constituted by the two-dimensional linear actuator described above, but is shown as a block in FIG. 1 for convenience of illustration.

Wafer stage WST has one side in the Y direction (for example, + Y direction) and one side in the X direction (for example, -X
Direction) are mirror-finished, and the wafer stage WST is
Are constantly detected at a resolution of, for example, about 0.5 to 1 nm.

Here, in practice, the wafer interferometer 24 is provided with three or more axes in the scanning direction and three or more axes in the non-scanning direction. 24. Then, the wafer interferometer 2
Based on the measurement result by 4, the position information (or the speed information) of the wafer stage WST in the five degrees of freedom excluding the Z direction is detected. The position information (or speed information) WPV of wafer stage WST is sent to stage controller 19 and main controller 20 via the same, and stage controller 19 sends the position information (or speed information) in response to an instruction from main controller 20. Or speed information) on the basis of WPV, the wafer stage WS
Control T.

Further, in the exposure apparatus 100 of the present embodiment, as shown in FIG.
An off-line for detecting the position of an alignment mark (wafer mark) attached to each shot area on the wafer W
An alignment microscope of an Axis system, for example, an imaging type alignment sensor ALG of an image processing system is provided. Measurement result data I of this alignment sensor ALG
MD2 is supplied to main controller 20.

In this exposure apparatus 100, an image forming beam (detection beam FB) for forming a plurality of slit images toward the best image forming plane of the projection optical system PL is oblique to the optical axis AX. An oblique incidence type multi-point focal position detection system comprising an irradiation optical system AF ₁ supplied from the optical system and a light receiving optical system AF ₂ for receiving each reflected light beam of the image forming light beam on the surface of the wafer W through a slit. AF is the projection optical system PL
Is fixed to a holding member (not shown) that supports As the multi-point focal position detection system AF (AF ₁ , AF ₂ ), for example, one having the same configuration as that disclosed in Japanese Patent Application Laid-Open No. Hei 5-190423 is used. Of the wafer holder 18 so that the wafer W and the projection optical system PL are kept at a predetermined distance.
For driving in the Z direction and the tilt direction. The wafer position information from the multipoint focus position detection system AF is sent to the stage controller 19 via the main controller 20. The stage control device 19 drives the wafer holder 18 in the Z direction and the tilt direction based on the wafer position information.

The irradiation optical system AF ₁ and the light receiving optical system AF ₂
Actually, the detection beam FB is irradiated on the wafer surface from a direction inclined at 45 degrees with respect to the X direction and the Y direction. However, in FIG. 1, for convenience of drawing, both ends of the projection optical system PL in the X direction are used. ₂ shows a state in which the irradiation optical system AF ₁ and the light receiving optical system AF ₂ are arranged.

A reference mark for baseline measurement and other reference marks for measuring the relative positional relationship between the position of the detection center of alignment sensor ALG and the position of the projected image of the reticle pattern are formed on wafer stage WST. A reference plate (not shown), a deviation of the wafer surface from a conjugate position with respect to the reticle pattern surface, an AIS reference plate (not shown) having a built-in sensor for measuring image quality and various aberrations of a projected image of the reticle pattern, and An illuminance non-uniformity sensor (not shown) for measuring illuminance non-uniformity in the exposure area IA is provided.

As shown generally in FIGS. 2A to 2C, the wafer holder 18 on the wafer stage WST has a circular shape in which both ends in the X direction are removed on the lower surface (side surface of the wafer stage). have. A notch 30 is formed at the end of the + X direction on the upper surface (wafer mounting surface) side of the wafer holder 18 so as to communicate the upper space and the lower space.
a and 30b are formed, and a notch 30c is formed at an end in the −X direction. Such a notch 30a,
A groove 31a is formed on the surface of wafer stage WST below 30b toward the + Y direction and extends to the edge of wafer stage WST, and on the surface of wafer stage WST below notch 30c in the + Y direction. Groove 31b extending to the edge of wafer stage WST is formed. The set of notches 30a, 30b, 30c and the set of grooves 31a, 31b are for inserting a carry-in arm described later.

Returning to FIG. 1, the exposure apparatus 100 further includes a wafer pre-alignment device 32 arranged at a wafer transfer position. The wafer pre-alignment device 32 is provided with a pre-alignment control device 34 and a relative position that is provided below the pre-alignment control device 34 and supports a wafer loading arm (hereinafter, referred to as a “loading arm”) 36 to vertically move and rotate. A vertical movement / rotation mechanism 38 as a drive mechanism, and three CCD cameras 40a, 40b, 40 as measurement devices disposed above the carry-in arm 36.
c. Under the control of the main controller 20, an image signal processing system for collecting image signals from the CCD cameras 40a, 40b, and 40c and transmitting the collected signals to the main controller 20 is provided inside the pre-alignment controller 34. A control system and the like for the rotation mechanism 38 are built in.

The CCD cameras 40a, 40b, 40c
This is for detecting the outer edge of the wafer W supported by the loading arm 36, respectively. CCD cameras 40a, 40
Here, as shown in the perspective view of FIG. 3, the b and 40c are 12 supported by the carry-in arm 36 as a support device.
The outer edge including the notch N of the inch wafer W ′ is arranged at a position where an image can be taken. Among them, the central CCD camera 40
a is for detecting a notch. In the present embodiment, the loading arm 36 has a T-shape in plan view,
Three fingers extend vertically downward from each of the three end points in the T-shape. A claw portion for supporting the wafer W is provided at a lower end of the three finger portions.

As shown in the plan view of FIG. 4, the position of the notch N on the wafer W 'is the position of the CCD camera 40a, and therefore the direction is the + Y direction (6 o'clock direction) when viewed from the center of the wafer W'. However, a state rotated by 90 ° from this state, that is, the −X direction (3
The wafer W ′ may be placed on the wafer holder 18 in a state where the notch comes in the (time direction). In such cases,
For example, as described in JP-A-9-36202, CCD cameras may be arranged at positions corresponding to both the three o'clock direction and the six o'clock direction, or the CCD cameras 40a, 40b, and 40c may be arranged at different positions. After detecting the outer shape, the wafer may be rotated by 90 ° using the vertical movement / rotation mechanism 38 of the wafer pre-alignment apparatus 32.

Further, as shown in FIG. 4, the exposure apparatus 100 of this embodiment has a wafer unloading arm (hereinafter, “unloading arm”) for unloading a wafer from the wafer holder 18.
), A wafer transfer arm 44 for transferring a wafer into the transfer arm 36, and an arm drive mechanism 46 for driving these. Here, the carry-out arm 42 and the wafer transfer arm 44 are driven by the arm drive mechanism 46 at a predetermined stroke along the Y-axis direction.

As is apparent from FIG. 4, the carry-out arm 42 is configured in exactly the same manner as the carry-in arm 36 described above. The difference is that the carry-in arm 36 is held at the lower end of the vertical movement / rotation mechanism 38, whereas the carry-out arm 42 is held by a vertical movement / slide mechanism 48 including a mover of a linear motor.

Returning to FIG. 1, the main controller 20 includes a CCD
A display device 21 such as a CRT display for displaying the results of imaging by the cameras 40a, 40b, 40c and the alignment sensor ALG, and an input device 22 such as a keyboard and a mouse for inputting operation instructions and the like by an operator are connected.

As shown in FIG. 5, main controller 20 determines (a) position information (speed information) RPV of reticle R and position information (speed information) WPV of wafer W based on:
A controller 59 for controlling the entire operation of the exposure apparatus 100 by supplying stage control data SCD to the stage controller 19, and (b) imaging data collection for collecting the imaging data IMD1 supplied from the wafer pre-alignment apparatus 32 The apparatus 51 and (c) a calibration reference wafer 3 described later.
Based on the imaging result data obtained by the CCD cameras 40a, 40b, 40c at the outer edge of the location, the CCD cameras 40a, 40b,
A reference wafer position adjusting device 53 for detecting position information of a first reference mark formed on the calibration reference wafer in the visual field area of 40b and 40c; and (d) three outer edge portions of the calibration reference wafer described later. CCD cameras 40a, 40
b, 40c, a calibration amount calculating device 54 for obtaining calibration information on the CCD cameras 40a, 40b, 40c and the loading arm 36, and (e) storing the image data collected by the image data collecting device 51. And an imaging data storage device 55. Further, main controller 20 performs calibration based on (f) an imaging data collection device 56 that collects imaging data IMD2 supplied from alignment sensor ALG, and (g) an imaging result of a calibration reference wafer by alignment sensor ALG. Reference wafer rotation amount detection device 5 for obtaining rotation amount of reference wafer around the central axis
7 and (h) an imaging data storage device 58 for storing the imaging data collected by the imaging data collection device 56.

In the present embodiment, the main controller 20 is configured by combining various devices as described above. However, the main controller 20 is configured as a computer system, and
It is also possible to realize the function of each of the above-described devices constituting the main controller 0 by a program and a memory area built in the main controller 20.

Hereinafter, the exposure operation of the exposure apparatus 100 according to the present embodiment will be described with reference to the flowchart shown in FIG.
Description will be made with reference to other drawings as appropriate.

First, in step 109 of FIG. 6, it is determined whether or not to calibrate the pre-alignment device 32. If a positive determination is made in step 109, the process proceeds to subroutine 101. The calibration of the pre-alignment apparatus 32 is performed at the time of installation or maintenance of the exposure apparatus 100, and a positive determination is made in such a case. On the other hand, if a negative determination is made in step 109, the process proceeds to step 102. In the case of normal lot processing, since the calibration of the pre-alignment device 32 is not performed, a negative determination is made. Hereinafter, description will be made assuming that the determination in step 109 is affirmative.

Next, in a subroutine 101, the CCD cameras 40a,
The magnification of 40b and 40c, the rotation amount of the visual field, the center position of the visual field at the normal time, and the rotation characteristics of the loading arm 36 are calibrated. In this subroutine 101, as shown in FIG.
The visual field positions of a, 40b, and 40c are adjusted.

It is assumed that the CCD camera 40a,
The fields of view of the wafers 40b and 40c are approximately 6 o'clock, 7:30 o'clock, and 4 o'clock of the wafer W mounted on the loading arm 36, respectively.
It is assumed that it is adjusted to be the outer edge in the half-hour direction.

The CCD cameras 40a, 40b, 40
c The coordinate system of the monitor screen (hereinafter referred to as “monitor coordinate system” or “camera optical coordinate system”) for each imaging result (XMa, YMa), (XMb, YMb), (XM
c, YMc) and a coordinate system (hereinafter, referred to as “stage coordinate system”) (X, Y) that defines the movement of the stage, as shown in FIGS. 8A to 8C. There is. That is, as shown in FIG.
+ XMa in the monitor coordinate system for the D camera 40a
Direction and + YMa direction are + X in the stage coordinate system.
Direction and the + Y direction. Also, as shown in FIG. 8B, the + XMb direction and + YMb direction in the monitor coordinate system for the CCD camera 40b correspond to the + X direction and + Y direction in the stage coordinate system. Also, as shown in FIG. 8C, the + XMc direction and + YMc direction in the monitor coordinate system for the CCD camera 40c correspond to the + X direction and + Y direction in the stage coordinate system.

In the subroutine 111, as shown in FIG. 9, first, in step 121, the tool wafer JW used in the above-described conventional pre-alignment is placed on the carry-in arm 36. This tool wafer JW
Is calibrated similarly to the one used in the conventional pre-alignment described above. On the surface of the tool wafer JW, as shown in FIG.
On its surface, three cross marks JMa, JMb, JMc are formed at the outer edge. These cross marks JMa,
JMb and JMc are cross marks J in FIG.
As typically shown for Ma, two rectangular patterns SP are obliquely arranged so as to be in contact at one point. Then, as shown in FIG. 10A, a line connecting the center of the cross mark JMa and the center O _J of the tool wafer JW and a line connecting the center of the cross mark JMb and the center of the tool wafer JW are formed. The angle is almost exactly 45 °, and
A line connecting the center of the cross mark JMa and the center O _J of the tool wafer JW, the center of the cross mark JMc and the tool wafer JW
Angle between the line connecting the center O _J of match almost exactly. In step 121, the tool wafer JW is placed on the carry-in arm 36 so that the cross mark JMa is substantially at the 6 o'clock position at the rotation position where the carry-in arm 36 is rotating.

Returning to FIG. 9, next, at step 122, the main controller 20 (more specifically, the controller 59) controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34 of the wafer pre-alignment device 32. By controlling, the carry-in arm 36 is fixed at a rotation position in the middle of the rotation stroke. Subsequently, in step 123, main controller 2
0 moves up and down via the pre-alignment control device 34.
By controlling the rotation mechanism 38 and moving the loading arm 36 in the Z-axis direction, the surface of the tool wafer JW is
a, 40b, and 40c are the height positions of the observation surface. FIG. 11 is a perspective view showing the vicinity of the tool wafer JW in this state.

Returning to FIG. 9, next, at step 124, the CCD 40 is controlled under the control of the main controller 20.
The tool wafer JW is imaged by a, 40b, and 40c. This imaging result is supplied to main controller 20 as imaging data IMD1. In the main controller 20, the imaging data collection device 51 receives the imaging data IMD1 and stores it in the imaging data storage area 55. Then, the control device 59
Reads out the imaging data stored in the imaging data storage area 55 and displays the imaging result on the display device 21 on the monitor.

Based on the display result on the monitor screen displayed as described above, the cross marks JMa, JMb, J in the respective imaging fields of view of the CCDs 40a, 40b, 40c.
Specify whether Mc exists. Cross mark JMa, JMb,
When any of the images of JMc is displaced from the center of the monitor screen beyond the allowable range, the cross marks JMa, JMb, JMc are determined based on the direction and the magnitude of the displacement.
Each of the CCDs 40a, 40b,
The tool wafer JW is positioned so as to be near the center of each imaging field of view 40c, that is, near the center of each monitor screen.
To move. Such movement of the tool wafer JW can be performed manually, and if the tool wafer JW is rotationally moved around the central axis, the main control device 20 is controlled in accordance with the rotation amount instruction input from the input device 22. However, it is also possible to control the vertical movement / rotation mechanism 38 via the pre-alignment control device 34.

Thus, the CCDs 40a, 40b, 40c
Cross marks JMa, JM near the center of each imaging field of view
The position of the tool wafer JW (including the rotational position around the central axis) is adjusted so that b and JMc are located.

Next, at step 125, the CCD
The optical systems of the CCD cameras 40a, 40b, and 40c are adjusted so that the center of the imaging field of view of each of the cameras 40a, 40b, and 40c matches the center position of the cross marks JMa, JMb, and JMc. Thus, the CCD cameras 40a, 4
The fields of view 0b and 40c are substantially in the directions of 6 o'clock, 7:30 o'clock, and 4:30 o'clock of the wafer (here, the tool wafer JW) supported by the loading arm 36, and the positional relationship between the viewing areas. Is the cross mark JMa, JMb, J
It is accurately adjusted based on the positional relationship between the Mcs.

As described above, the CCD camera 40a,
When the adjustment of the visual field position of each of 40b and 40c ends, the processing of subroutine 111 ends, and the processing shifts to subroutine 112 of FIG.

In the subroutine 112, as shown in FIG. 12, first, in step 131, a reference wafer SW as a reference wafer for calibration is placed on the wafer holder 18. The reference wafer SW has a first reference mark FSMa, FSMB, FSMC and a second reference mark SSMa, SSMB, SSMC, SSMd as shown in FIG. I have.

First fiducial marks FSMa, FSMb, FS
Mc indicates that the mark center position indicated by ◆ of the basic mark FSM shown in FIG. 14 is in the wafer coordinate system (X _W , Y _W ) at the 6 o'clock direction, the 7:30 o'clock direction, and the 4:30 o'clock direction of the reference wafer SW. Is formed by drawing on the surface of the reference wafer SW so as to be positioned at the outer edge of the reference wafer SW. As shown in FIG. 14, the basic mark FSM has rectangular deposition portions CP arranged in a checkerboard pattern, so that rectangular deposition portions CP and rectangular non-deposition portions CS are two-dimensionally and alternately arranged. The first basic mark FTM. In the first basic mark FTM, the vapor deposition portion CP and the non-vapor deposition portion C at the central portion (that is, other than the peripheral portion)
S is the length LX of one side (for example, 2.5 mm),
The rectangular shape has a length LY (for example, 1 mm) of a side orthogonal to the one side. Then, on the same straight line that extends in the vertical (and horizontal) direction on the paper passing through the contact point between the one vapor deposition unit CP at the center and the obliquely adjacent vapor deposition unit CP, extends from the contact point in the vertical (and horizontal) direction on the paper. One deposition unit CP in the center
And the side of the vapor deposition section CP obliquely adjacent thereto. That is, the boundary between the vapor deposition unit CP and the non-vapor deposition unit CS forms a lattice over the entire area of the first basic mark FTM. As a result, the intersection point of the lattice, that is, the contact point between one vapor deposition unit CP in the center and the vapor deposition unit CP obliquely adjacent thereto is
By detecting the boundary between the vapor deposition unit CP and the non-vapor deposition unit CS in the image of the captured result, the shape feature point is a shape feature point at which a two-dimensional position can be detected with high accuracy. In the following description, a contact point between one vapor deposition unit CP at the center and a vapor deposition unit CP obliquely adjacent thereto is referred to as a “grid point”.

The basic mark FSM has two first small circle patterns STM1 and two second small circle patterns STM2 formed in the area of the first basic mark FTM. In the following description, the first small circle pattern S
When TM1 and the two second small circle patterns STM2 are collectively referred to, they are referred to as “second basic marks STM”. Further, the basic mark FSM is the first basic mark FT
Two first great circle patterns TTM formed outside the area of M
1, two second great circle patterns TTM2 and two third great circle patterns TTM2
It has a great circle pattern TTM3. In the following description, when the two first great circle patterns TTM1, the two second great circle patterns TTM2, and the two third great circle patterns TTM3 are collectively referred to as "third basic mark TT"
M ”.

The basic mark FSM composed of the first basic mark FTM, the second basic mark STM, and the third basic mark TTM has a 180 ° rotational symmetry about its center (◆). The size of the formation area of the first basic mark FTM is determined by the CCD cameras 40a, 40b, 40c.
And the size of the imaging field of view.

In FIG. 14, symbols * and * for specifying the direction of the basic mark are shown in other figures, but these symbols * and * do not constitute the basic mark FSM.

Returning to FIG. 13, on the surface of the reference wafer SW, the above-mentioned basic mark FSM is positioned at the center position (中心) of the outer edge portion of the reference wafer SW in the 6 o'clock direction, the 7:30 direction, and the 4:30 direction. , And is drawn in the direction specified by the above-mentioned symbols ★, ☆. As a result, the first reference marks FSMa, FSMa actually formed on the surface of the reference wafer SW.
b and FSMc are marks including a little more than half of the area including the center of the basic mark FSM. Also, the basic mark F
First reference mark FS on which center position (◆) of SM is formed
The positional relationship between the respective positions of Ma, FSMb, and FSMC (hereinafter, referred to as “center positions of first reference marks FSMa, FSMb, and FSMC”) is based on the positions of the center positions of cross marks JMa, JMb, and JMc on tool wafer JW described above. The positional relationship is almost the same as the relationship.

The first fiducial marks FSMa, F formed by drawing approximately half the area of the basic mark FSM are drawn.
SMb and FSMC have the shapes shown in FIGS. 15 (A) to 15 (C). These FIGS. 15A to 1
5 (C), the first fiducial marks FSMa,
FSMb and FSMc are each a first basic mark FTM.
(Hereinafter referred to as “first marks FTMa, FTMb,
FTMc ”), 1 in the second basic mark STM.
The second marks STMa, STMb, and the second marks STMa, STMb, and STM1 each include one first small circle pattern STM1 and one second small circle pattern STM2.
STMc and one first great circle pattern TTM1 and one second great circle pattern TT in the third basic mark TTM
M2 and third marks TTMa, TTMb, and TTMc composed of one third great circle pattern TTM3.

Here, the CCD cameras 40a, 40b, 4
0c, the second mark STMa, ST
If Mb and STMC can be detected, the position detection point where the contact point between one vapor deposition unit CP in the captured image and the vapor deposition unit CP obliquely adjacent thereto is located in the first marks FTMa, FTMb, and FTMc. Can be uniquely specified. In the following, the second marks STMa, S
TMb and STMC are referred to as “Unique Mark STMa, STM
b, STMc ".

The CCD cameras 40a, 40b, 40
c and the first fiducial marks FSMa, F
When the unique marks STMa, STMb, and STMC are not detected in the captured image because the centers of SMb and FSMC are displaced from each other, a large circle that constitutes the third marks TTMa, TTMb, and TTMc up to a certain amount of displacement. At least one of the patterns TTM1, TTM2, and TTM3 can be detected. In such a case, the CCD is determined based on the position of at least one of the detected great circle patterns TTM1, TTM2, and TTM3 in the captured image.
A correction amount for a deviation between the center of the field of view of the camera 40a, 40b, 40c and the center of the first reference marks FSMa, FSMb, FSMC is obtained, and the position of the reference wafer SW (including the rotational position around the central axis) is determined by the correction amount. ), The unique marks STMa, STMb, STMC
Can be obtained with such an accuracy that it can be included in the captured image. In the following, the third marks TTMa,
Great circle pattern TTM1, TTMb in TTMb, TTMc
Each of TM2 and TTM3 is referred to as "large deviation mark TTM1,
TTM2, TTM3 ".

Referring back to FIG. 13, the second fiducial marks SSMa,
SSMb, SSMc, SSMd respectively, at the surface of the reference wafer SW, is formed to have a rectangular top position with a parallelogram to X _W axis or Y _W axis. Also, the second fiducial marks SSMa, SSMb, SSMC, SSMd are 2
This is a two-dimensional mark, such as a dimensional line and space mark, whose two-dimensional position can be accurately detected.

Returning to FIG. 12, next, at step 132, main controller 20 sets the wafer pre-alignment device 3
The vertical movement / rotation mechanism 38 is controlled via the second pre-alignment control device 34, and the carry-in arm 36 is fixed at the middle rotation position. Subsequently, in step 133,
Design position of the wafer loading position on the wafer holder 18 by the loading arm 36 (hereinafter, referred to as “design loading position”)
Is moved to the reference wafer SW. Such reference wafer SW
The main controller 20 moves the wafer driving device 15 based on the position information (or speed information) WPV of the wafer stage WST (and, consequently, the wafer W) from the wafer interferometer 24.
Is performed by controlling the drive of the wafer stage WST through the interface.

Next, at step 134, the main controller 20 controls the vertical movement / rotation mechanism 38 via the pre-alignment controller 34, and picks up the reference wafer SW from the wafer holder 18 by the loading arm 36.
Subsequently, at step 135, main controller 20
However, the vertical movement / rotation mechanism 38 is controlled via the pre-alignment control device 34, and the carry-in arm 36 is moved in the Z-axis direction so that the surface of the reference wafer JW is
The height position of the observation surface is defined by 40b and 40c. FIG.
FIG. 2 is a perspective view showing the vicinity of the tool wafer JW in this state.

Returning to FIG. 12, next, in step 136, the reference wafer SW is imaged by the CCD cameras 40a, 40b, and 40c under the control of the main controller 20. This imaging result is supplied to main controller 20 as imaging data IMD1. In the main controller 20, the imaging data collection device 51 receives the imaging data IMD1 and stores it in the imaging data storage area 55. Continued
In step 137, the reference wafer position adjusting device 53
Reads the imaging data from the imaging data storage area 55 and determines whether any of the unique marks STMa, STMb, and STMC was detected in the images captured by the CCD cameras 40a, 40b, and 40c. Here, if a positive determination is made, the process proceeds to step 144. On the other hand, if a negative determination is made, the process proceeds to step 138. At this stage, the following description will be given assuming that a negative determination has been made.

In step 138, the reference wafer position adjusting device 53 sets the large misalignment marks TTM1, TTM in one of the images captured by the CCD cameras 40a, 40b, 40c.
It is determined whether one of TM2 and TTM3 has been detected. Here, if a positive determination is made, the process proceeds to step 139. On the other hand, if a negative judgment is made, the reference wafer position adjusting device 53 informs the control device 5 of that fact.
9 and then the process proceeds to step 142. At this stage, the following description will be given assuming that a negative determination has been made.

At step 142, main controller 20
Controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34, and places the reference wafer SW on the wafer holder 18 by the carry-in arm 36. Then, the carry-in arm 36 is retracted upward. Subsequently, the main controller 20
Controls the driving of the wafer stage WST via the wafer driving device 15 based on the position information (or speed information) WPV of the wafer stage WST from the wafer interferometer 24, and retracts the reference wafer SW from immediately below the loading arm 36. .

Next, in step 143, the reference wafer SW on the wafer holder 18 is replaced. Then, the process proceeds to step 132.

Thereafter, in the same manner as described above, main controller 20
Under the above control, the carry-in arm 36 is fixed at the middle rotation position (Step 132), and the reference wafer SW is moved to the design load position (Step 133). Subsequently, the reference wafer SW is picked up by the loading arm 36 (step 134), and the surface thereof is
a, 40b, 40c are set on the observation plane (step 13
5), the reference wafer SW is imaged by the CCD cameras 40a, 40b, 40c (step 136).

Next, at step 137, the CCD
It is determined whether any one of the unique marks STMa, STMb, and STMC is detected in the captured images of the cameras 40a, 40b, and 40c. At this stage, a negative determination is made as in the previous case, and the process proceeds to step 138, and the following description will be made.

At step 138, the CCD camera 4
0a, 40b, 40c,
It is determined whether any of the large displacement marks TTM1, TTM2, and TTM3 has been detected. At this stage, an affirmative determination is made unlike the previous time, and the process proceeds to step 139.
The following description will be made assuming that the process proceeds to.

In step 139, the reference wafer position adjusting device 53 detects the large misalignment marks TTM1 and TTM1 based on the images captured by the CCD cameras 40a, 40b and 40c.
The positions of the TTM2 and TTM3 in the detected imaging visual field are obtained. Subsequently, in step 140, the reference wafer position adjusting device 53 sets the obtained large deviation mark TT
Based on the positions of M1, TTM2, and TTM3, the X direction, Y direction, and θ of the position of the reference wafer SW from the adjustment target position for the reference wafer SW in the stage coordinate system
The deviation in the direction (around the center axis of the reference wafer SW parallel to the Z axis) is calculated with an accuracy corresponding to the detection accuracy of the positions of the large deviation marks TTM1, TTM2, and TTM3, and is notified to the control device 59. Hereinafter, the calculation result of the positional deviation is represented by (ΔX _R ,
ΔY _R , θ _R ).

Next, in step 141, the position of the reference wafer SW is roughly adjusted by correcting the calculated positional deviations (ΔX _R , ΔY _R , θ _R ). In the coarse adjustment, first, the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34, and the reference wafer SW is
Place on 8. Then, the carry-in arm 36 is retracted upward. Subsequently, control device 59 drives and controls wafer stage WST via wafer driving device 15 based on position information (or speed information) WPV from wafer interferometer 24,
Reference wafer SW in X-axis direction -ΔX _R and Y-axis direction-
Move by ΔY _R. Next, the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34.
, And the reference arm SW is picked up from the wafer holder 18 by the carry-in arm 36. And the control device 5
9 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34 to rotate the carry-in arm 36 by −θ _R. Thus, the displacement (Δ
_{X R, ΔY R, θ R} ) is corrected.

Next, in step 136, under the control of the main controller 20, the CCD cameras 40a, 40
The reference wafer SW is imaged by b and 40c, and the imaging result is stored in the imaging data storage area 55. Subsequently, the reference wafer position adjusting device 53 reads out the image data from the image data storage area 55 and
It is determined whether any one of the unique marks STMa, STMb, and STMc has been detected in the captured images a, 40b, and 40c. At this stage, an affirmative determination is made and the process proceeds to step 144, and the following description will be made.

In step 144, the reference wafer position adjusting device 53 determines the positions of the unique marks STMa, STMb, and STMC in the field of view. Then, the obtained unique marks STMa, STMb, S
Based on the position of TMc, the position of the reference wafer SW from the adjustment target position with respect to the reference wafer SW in the X direction, the Y direction, and the θ (around the center axis of the reference wafer SW parallel to the Z axis) in the stage coordinate system. The shift is calculated and notified to the control device 59. Hereinafter, the calculation result of the positional deviation is referred to as (ΔX _F , ΔY _F , θ _F ).

Next, at step 145, the control device
59 is the calculated displacement (ΔX _F, ΔY_F, Θ_F)But
The value of the reference wafer SW depends on whether the value is within the allowable range.
Determine whether the position is appropriate. Where positive
When the determination is made, the processing of the subroutine 112 is completed.
And return. On the other hand, if a negative decision is made,
The process proceeds to step 146. Negative at this stage
The following description will be made on the assumption that such a judgment has been made.

In step 146, the control device 59
But positional deviation above _{(ΔX R, ΔY R, θ} R) as in the case of, by controlling the vertical movement and rotation mechanism 38 and the wafer drive apparatus 15, the positional deviation _{(ΔX F, ΔY F, θ} F) , The position of the reference wafer SW is finely adjusted. Then, the process proceeds to step 136.

Thereafter, steps 136, 137, and 137 are repeated until a positive determination is made in step 145.
Step 144, step 145, and step 146
Is executed. Then, the reference wafer SW is adjusted to a position suitable for imaging of the first reference marks FSMa, FSMb, FSMC by the CCD cameras 40a, 40b, 40c with a predetermined tolerance. Reference wafer S
The position of W in the stage coordinate system (X, Y) is _{equal to} the actual load position (X _L0 ,
Y _L0 ). Then, the subroutine 112
Is completed, and the process proceeds to step 113 in FIG.

In step 113, the control device 59
, The rotation amount of the reference wafer SW in the stage coordinate system (X, Y), that is, the rotation amount of the wafer coordinate system (X _W , Y _W ) with respect to the stage coordinate system (X, Y) is measured. . In such measurement, first, the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34, and places the reference wafer SW on the wafer holder 18 by the carry-in arm 36. Then, the carry-in arm 36 is retracted upward. Subsequently, control device 59 drives and controls wafer stage WST via wafer driving device 15 based on position information (or speed information) WPV from wafer interferometer 24, and outputs second reference marks SSMa, SSMa on reference wafer SW. SSMb, SSMc, SSMd
Are sequentially moved below the alignment sensor ALG, and the second reference marks SSMa, SSMb, SSMC, S are moved by the alignment sensor ALG.
Image SMd. This imaging result is obtained from the imaging data IMD
2 is supplied to the main controller 20. Main controller 2
0, the imaging data collection device 56 sets the imaging data IMD2
Is received and stored in the imaging data storage area 58.

Next, the reference wafer rotation amount detection device 57
The imaging data storage area 58 is read out, and the second reference marks SSMa, SSMa,
Detect the two-dimensional position of SSMb, SSMc, SSMd,
The detection result is notified to the control device 59. Subsequently, the control device 59 compares the detection result with the second fiducial marks SSMa, S
Position information W in imaging of SMb, SSMC, and SSMd
From PV, the second fiducial marks SSMa, SSMb, SS
The XY position in the stage coordinate system of Mc, SSMd is obtained. Then, the control device 59 transmits the mark SSMa,
The rotation amount of the reference wafer SW in the stage coordinate system (X, Y) is calculated based on the positions of SSMb, SSMc, and SSMd. Note that the rotation amount calculated in this manner is represented by α. The control device 59 notifies the rotation amount α to the calibration amount calculation device 54.

Next, the control device 59 controls the wafer interferometer 2
The wafer stage WST is driven and controlled via the wafer driving device 15 on the basis of the position information (or speed information) WPV from the reference wafer SW and the reference wafer SW is moved to the load point position (X _L0 ,
Y _L0 ). Subsequently, after the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34 and scoops the reference wafer SW from the wafer holder 18 by the loading arm 36,
The surface of the reference wafer SW is moved by CCD cameras 40a, 40b,
It is set to the observation plane by 40c.

Next, at step 114, the CCD camera
The magnification in the X-axis direction of each of the cameras 40a, 40b, 40c
And the magnification in the Y-axis direction are calibrated. With such a magnification calibration
First, under the control of the main controller 20, the CCD camera
The reference wafer SW is changed by the cameras 40a, 40b and 40c.
An image is captured, and the image data IMD1 is stored in the image data storage area.
It is stored in area 55. Such CCD cameras 40a, 40
FIGS. 17A to 17C show the imaging results of FIGS.
It is shown in (C). That is, FIG.
The imaging result by the CD camera 40a is displayed in the monitor coordinate system (XM
_a, YM_a), And FIG. 17B shows a CCD camera.
The image pickup result by the monitor coordinate system (XM _b, YM_b)
In FIG. 17C, a CCD camera 40c is used.
Imaging results are displayed on the monitor coordinate system (XM_c, YM_c)
ing.

Subsequently, the calibration amount calculating device 54 reads out the image data from the image data storage area 55, and
(A) Four grid points Pm indicated by “○”
_{m a, Ppm a, Pmp a} , Ppp a monitor coordinate system (XM
_a , YM _a ) at positions (Xmm _a , Ymm _a ), (Xp
m _a , Ypm _a ), (Xmp _a , Ymp _a ), (Xpp _a ,
Ypp _a ) is detected. Here, the grid point P mm _a lattice point Ppm _a have a relationship spaced along the XM _a-axis direction, spaced along the XM _a-axis direction to the lattice point Pmp _a lattice point Ppp _a In a relationship. Also, the lattice point Pm
The m _a and the lattice point Pmp _a have a relationship spaced along the YM _a-axis direction, the grid point Ppm _a lattice point Ppp _a in a relationship spaced along the YM _a-axis direction.

The lattice points Pmm _a , Ppm _a , P
In detecting the positions of mp _a and Ppp _a , first, an observation window having a size that can enter only one grid point is set around the design position of each of the grid points Pmm _a , Ppm _a , Pmp _a , and Ppp _a . Based on the image data in the observation window, the positions of the lattice points Pmm _a , Ppm _a , Pmp _a , and Ppp _a are obtained. Next, the lattice point Pm thus obtained is
m _a, set the Ppm _a, Pmp _a, sufficiently large observation window around the position of Ppp _a, on the basis of the image data in the observation in the window, the grid point P mm _a, Ppm _a, Pm
The positions of p _a and Ppp _a are obtained again. Then, the obtained re lattice point _{Pmm a, Ppm a, Pmp a} , position above the position of _{Ppp a (Xmm a, Ymm a} ), (Xpm a, Yp
m _a ), (Xmp _a , Ymp _a ), (Xpp _a , Ypp _a )
To be adopted. Thereby, the vapor deposition part CP and the non-vapor deposition part S
Regarding detection of a grid point position by detecting a boundary with P,
It is possible to detect the position of the lattice point with high accuracy by overcoming the deterioration of the image processing accuracy in the case of the small observation window in the previous stage.

The grid points Pmm _a , Ppm _a , Pm
In detecting the positions of p _a and Ppp _a , first, a unique mark is detected, and as a result, the position of the grid point to be detected is calculated from STMa. Then, a sufficiently large observation is performed with the calculated grid point position as the center. A window is set, and lattice points Pmm _a , Pmm _a are set based on image data in the observation window.
pm _a , Pmp _a , Ppp _a position (Xmm _a , Ym
m _a ), (Xpm _a , Ypm _a ), (Xmp _a , Ym
p _a ) and (Xpp _a , Ypp _a ) can be obtained again. Even in such a case, the position of the grid point can be detected with high accuracy.

Further, a grid composed of the boundary between the vapor deposition section CP and the non-vapor deposition section SP in the entire field of view of the CCD camera 40a is detected, and the lattice point Pmm _a , Ppm _a , Pmp _a , Ppp _a
Position of _{(Xmm a, Ymm a),} (Xpm a, Ypm a),
_(Xm p, Ymp _a), it can also be determined (Xpp _a, Ypp _a). In such a case, it takes time to detect the grid, but since the positional relationship of all grid points is analyzed, it is effective in preventing misregistration and erroneous detection of the mark, and the position of the grid point to be detected can be obtained with high accuracy. it can.

Next, the calibration amount calculating device 54 calculates the grid point Pm
_{m a, Ppm a, Pmp a} , the position of Ppp _a (Xmm _a, Y
mm _a ), (Xpm _a , Ypm _a ), (Xmp _a , Ym
p _a ), (Xpp _a , Ypp _a ) and the reference wafer S described above.
Based on the W rotation amount α of, magnification MX _a and Y-axis direction of the X-axis direction of the CCD camera 40a magnification MY _a (unit: [pixel
/ Mm]) is calculated by the following equations (1) and (2) using β as a parameter.

MX _a = {(Xpp _a −Xmp _a ) / (2 · LX · cos (α + β)) + (Xpm _a −Xmm _a ) / (2 · LX · cos (α + β))} / 2 (1) )

[0122] _{MY a = {(Ypp a -Ypm} a) / (LY · cos (α + β)) + (Ymp a -Ymm a) / (LY · cos (α + β))} / 2 ... (2)

Here, the parameter β is the reference wafer SW
Is the amount of rotation deviation that may occur when the wafer is loaded on the carry-in arm 36 from the wafer holder 18. The method for determining the parameter β will be described later.

Next, the calibration amount calculating device 54 uses the grid
Point Pmm_a, Ppm_a, Pmp_a, Ppp_aPosition (Xmm
_a, Ymm_a), (Xpm_a, Ypm_a), (Xmp_a, Y
mp _a), (Xpp_a, Ypp_a),
Based on the imaging data from the imaging data storage area 55, FIG.
17 (B), three grid points Pc indicated by “○”
p_b, Ppm_b, Ppp_bMonitor coordinate system (XM_b, Y
M_b) (Xcp)_b, Ycp_b), (Xpm_b,
Ypm_b), (Xpp_b, Ypp_b) Is detected. here
And the lattice point Pcp_bAnd the lattice point Ppp_bIs XM_bAlong the axis
They are separated from each other. Also, the grid point Ppm_bWhen
Lattice point Ppp_bIs YM_bPositions separated along an axis
In charge.

Then, the calibration amount calculating device 54 calculates the grid point position.
(Xcp_b, Ycp_b), (Xpm _b, Ypm_b), (X
pp_b, Ypp_b) And the rotation amount α of the reference wafer SW described above.
, The magnification MX of the CCD camera 40b in the X-axis direction_b
And magnification MY in the Y-axis direction_b(Unit: [pixel / mm])
Using β as a parameter, the following equations (3) and (4)
Is calculated.

MX _b = (Xpp _b −Xcp _b ) / (LX · cos (α + β)) (3) MY _b = (Ypp _b −Ypm _b ) / (2 · LY · cos (α + β)) (4) )

Subsequently, the calibration amount calculating device 54 calculates the positions (X X) of the lattice points Pmm _a , Ppm _a , Pmp _a , and Ppp _{a.
mm a, Ymm a), (} Xpm a, Ypm a), (Xm
_{p a, Ymp a), (} Xpp a, Ypp case of _a) and in the same manner, based on the imaging data from the imaging data storage area 55, three lattice points P mm _c indicated by "○" in Fig. 17 (C) , Pmp _c , Pcp _c monitor coordinate system (XM _c ,
YM _c ), (Xmm _c , Ymm _c ), (Xm
p _c, Ymp _c), to detect the (Xcp _c, Ycp _c). Here, the lattice point Pmp _c and the lattice point Pcp _c are in a relationship separated along the XM _c axis. The lattice point Pmm _c and the lattice point Pmp _c are separated from each other along the YM _c axis.

Then, the calibration amount calculating device 54 calculates the grid point position.
(Xmm_c, Ymm_c), (Xmp _c, Ymp_c), (X
cp_c, Ycp_c) And the rotation amount α of the reference wafer SW described above.
, The magnification MX of the CCD camera 40c in the X-axis direction_c
And magnification MY in the Y-axis direction_c(Unit: [pixel / mm])
Using β as a parameter, the following equations (5) and (6)
Is calculated.

[0129] _{MX c = (Xcp c -Xmp c} ) / (LX · cos (α + β)) ... (5) MY c = (Ymp c -Ymm c) / (2 · LY · cos (α + β)) ... (6 )

Next, in step 115, the amount of rotation of the field of view of the CCD cameras 40a, 40b, 40c is calibrated. This rotation amount of the calibration, an origin load point position, parallel to X _L and X axes, load point coordinate system defined by the Y-axis parallel to Y _L axis (hereinafter, referred to as "LP coordinate system" ) (X _L, CCD camera 40 for Y _L)
The rotation amounts of the imaging fields of view a, 40b, and 40c are calibrated. In the calibration of the rotation amount of the imaging field of view, X _i (i
= A, b, c) two collinear on a line parallel to the axis and the rotation amount of the X _L direction standards required in accordance with the difference between the Y _i coordinate values for grid points, Y _i collinear parallel to axis obtaining an average value of the rotation amount of the Y _L direction standards required in accordance with the difference between the X _i coordinate values for the two grid points.

That is, the CCD cameras 40a, 40b,
Rotation of the imaging field of view _{40c θ a, θ b, θ} c ( unit: [ra
d]), the rotation amounts θ _a , θ _b , θ _c are sufficiently small and tan
Assuming that θ = θ is in a range that can be satisfied with high accuracy, it is calculated by the following equations (7) to (9).

[0132] _{θ a = {- ((Ypp} a -Ymp a) + (Ypm a -Ymm a)) / (2 · 2 · LX · cos (α + β) · MX a) + ((Xpp a -Xpm a) + (Xmp _a −Xmm _a )) / (2 · LY · cos (α + β) · MY _a )｝ / 2+ (α + β) (7)

Θ _b = {− (Ypp _b −Ycp _b ) / (LX · cos (α + β) · MX _b ) + (Xpp _b −Xpm _b ) / (2 · LY · cos (α + β) · MY _b )} / 2 + (α + β) (8)

Θ _c = {(Ycp _c −Ymp _c ) / (LX · (cos α + β) · MX _c ) − (Xmp _c −Xmm _c ) / (2 · LY · cos (α + β) · MY _c )} / 2 − (Α + β)… (9)

Subsequently, in step 116, the calibration amount calculating device 54 sets the CCD cameras 40a, 40b, 40
Calibrate the center position of the imaging field of view c. The calibration of the center position is performed in the following manner as described below.
This is performed by obtaining the center position of the imaging field of view b, 40c.

In detecting the center position of the field of view, first, C
The design value (X _si0 , Y _si0 ) of the center position of the first mark FTMi in the imaging field of view of the CD camera 40i (i = a, b, c) is defined as (X _si0 , Y _si0 ), and the reference wafer SW is loaded from the wafer holder 18 into the loading arm 36. X _L direction and the Y _L direction deviation amount when put on as D _X and D _Y, the expected center location in LP coordinates of the first mark FTMi (X _si,
Y _si ) is _expressed by: X _si = X _si0 · cos (α + β) −Y _si0 · sin (α + β) + D _X (10) Y _si = X _si0 · sin (α + β) + Y _si0 · cos (α + β) + D _Y ( 11) Obtain by Incidentally, the deviation amount D _X, will be described later determination of D _Y.

Next, the center position of the first mark FTMi (X ′ _0i ,
Y ′ _0i ) (unit: [pixel]) is represented by the following (12) to (1).
Calculated by equation 7).

[0138] [If the 6 o'clock direction of the CCD camera _{40a] X '0a = (Xpm} a + Xmm a) / 2 -LY · MX i · sin (θ a - (α + β)) ... (12) Y' 0a = ( _{Ypm a + Ymm a) / 2} -L Y · MY i · cos (θ a - (α + β)) ... (13)

[0139] [For 7:30 direction of the CCD camera _{40b] X '0b = Xcp b} -2 · LY · MX i · sin (θ b - (α + β)) ... (14) Y' 0b = Ycp b -2・ LY ・ MY _i・ cos (θ _a − (α + β))… (15)

[0140] [For 4:30 direction of the CCD camera _{40c] X '0c = Xcp c} +2 · LY · MX i · sin (θ c + (α + β)) ... (16) Y' 0c = Ycp c -2 · LY ・ MY _i・ cos (θ _c + (α + β)) (17)

Subsequently, the obtained first mark FTMi is obtained.
Center position of the _{(X '0i, Y' 0i} ) to correct the magnification MX _i and the rotation amount theta _i of the CCD camera 40i and is converted into a value of LP coordinate system. Then, the predicted center position (X _si , Y _si ) of the first mark in the above-described LP coordinate system is corrected using the converted value, thereby obtaining the center position (X _ci , Y _ci ) of the field of view of the CCD camera 40i. . That is, the visual field center position (X _ci , Y _ci ) (i = a, b, c) is calculated by the following (18) to
It is calculated by equation (23).

[CCD camera 40a in 6 o'clock direction]

[CCD camera 40b in the 7:30 direction]

[Case of CCD camera 40c in the direction of 4:30]

Next, in step 117, the calibration amount calculating device 54 determines the rotation rate and LP of the carry-in arm 36.
Calibrate the rotation center position in the coordinate system. The calibration of the loading arm 36 is performed by detecting the rotation rate of the loading arm 36 and the rotation center position in the LP coordinate system as described below.

First, assuming that the middle rotation position (the count value of the rotary encoder is “0”) is a rotation angle of 0 °, a total of 5 positions of 0 ° and two positions in the positive rotation direction and two positions in the negative rotation direction.
At that point, the count value of the rotary encoder at that time and the center position of the first mark FTMi in the monitor coordinate system at that time are detected. In the following description, the rotational positions of the five loading arms 36 are set to j (j = j).
−2, −1, 0, 1, 2), the count value of the rotary encoder is represented by N _j , and the first mark FTM
The center position of i in the monitor coordinate system is represented by (XR _ij , Y
R _ij ).

At this time, the center position (XR _ij , YR _ij ) (unit: [pixel]) is shown in FIG.
17C based on the detection results of the positions of the lattice points shown in FIG. 17C. Incidentally, [psi in (24) - (32) _i (i =
The unit of a, b, c) is [rad].

[In the case of the CCD camera 40a in the 6 o'clock direction] XR _aj = Xcp _a −2 · LY · MX _a · sin (ψ _a − (α + β)) (24) YR _aj = Ycp _a −2 · LY · _{MY a · cos (ψ a -} (α + β)) ... (25) ψ a = {- ((Ypp a -Ymp a) + (Ypm a -Ymm a)) / ((Xpp a -Xmp a) + (Xpm _{a -Xmm a)) + ((} Xpp a -Xpm a) + (Xmp a -Xmm a)) / ((Ypp a -Ypm a) + (Ymp a -Ymm a))} / 2 + (α + β) ... (26)

[0149] [For 7:30 direction of the CCD camera _{40b] XR bj = Xcp b -2} · LY · MX b · sin (ψ b - (α + β)) ... (27) YR bj = Ycp b -2 · LY _{· MY b · cos (ψ b} - (α + β)) ... (28) ψ b = {- (Ypp b -Ycp b) / (Xpp b -Xcp b) + (Xpp b -Xpm b) / (Ypp b - Ypm _b )｝ / 2+ (α + β) (29)

[In the case of the CCD camera 40c in the direction of 4:30] XR _cj = Xcp _c + 2 · LY · MX _c · sin (ψ _c + (α + β)) (30) YR _cj = Ycp _c −2 · LY · _{MY c · cos (ψ c +} (α + β)) ... (31) ψ c = {(Ycp c -Ymp c) / (Xcp c -Xmp c) - (Xmp c -Xmm c) / (Ymp c -Ymm c )｝ / 2− (α + β) (32)

[0151] Subsequently, the calibration amount calculation device 54, taking into account the field center position of the CCD camera 40i described above (X _ci, Y _ci), center position in the monitor coordinate system (XR _ij, YR
_ij ) to the center position (XL _ij , YL _ij ) in the LP coordinate system
Is converted using the following equations (33) and (34).

[0152] _{XL ij = X ci + XR ij} · cosψ i / MX i -YR ij · sinψ i / MY i ... (33) YL ij = Y ci + XR ij · sinψ i / MX i + YR ij · cosψ i / MY i … (34)

Next, the calibration amount calculating device 54 calculates each rotational position.
j (Estimated value of each rotation: φ_j’(Unit: [rad]), rotary
Encoder count value: N_j, Φ₀'= 0, N₀= 0)
1st mark F between each CCD camera 40i
The difference between the center positions of TMi (ΔX _kj, ΔY_kj) (K = 1,
2, 3) is calculated by the following equations (35) to (37).
You.

(ΔX _1j , ΔY _1j ) = (XL _bj −XL _cj , YL _bj −YL _cj ) (35) (ΔX _2j , ΔY _2j ) = (XL _cj −XL _aj , YL _cj −YL _aj ) (36) (ΔX _3j , ΔY _3j ) = (XL _aj −XL _bj , YL _aj −YL _bj ) (37)

[0155] Then, the calibration amount calculation device 54, rotating each estimate phi _j 'of the loading arm 36 at each rotational position j,
It is calculated by the following equation (38).

[0156]

(Equation 1)

Subsequently, the calibration amount calculating device 54 calculates the rotation rate R _{j according} to the following equation _: R _j = φ _j ′ / N _j (39)

Next, the calibration amount calculating device 54 calculates the rotational center position (Xc, Yc) of the carry-in arm 36 by the following equations (40) and (41).

[0159]

(Equation 2)

[0160]

(Equation 3)

Note that C _j and S _j in the equations (42) and (43) are as follows: C _j = cos φ _j ′ (42) S _j = sin φ _j ′ (43)

As described above, the calibration amount calculating device 54
Regarding the obtained CCD camera 40i (i = a, b, c)
Magnification MX_i, MY_i, Rotation of imaging field of view with respect to LP coordinate system
Quantity θ _i, And the center position of the field of view in the LP coordinate system
(X_ci, Y_ci), And the rotation rate R of the loading arm 36.
_jAnd the rotation center position (Xc, Yc) in the LP coordinate system
Is supplied to the control device 59. The control device 59
Thereafter, the reference wafer is transferred from the wafer holder 18 to the carry-in arm 36.
While the SW is turned on several times, the calibration amount
Investigate the reproducibility of the calibration results. And the best reproducibility
Parameters β, D_X, D_YDetermine the value of. This way
Fixed parameters β, D_X, D_YUsing the value of CC
Magnification M for D camera 40i (i = a, b, c)
X_i, MY_iOf the field of view with respect to the, LP coordinate system
θ_i, And the center position (X
_ci, Y_ci), And the rotation rate R of the loading arm 36._jPassing
Of the rotation center position (Xc, Yc) in the LP and LP coordinate systems
A positive value is specifically calculated. Then, the calculated calibration value is
Set as a device constant.

As described above, when the calibration of the CCD camera 40i and the carry-in arm 36 is completed, the subroutine 101 is completed. Then, step 1 of the main routine of FIG.
The process shifts to 02.

In step 102, under the control of main controller 20, reticle R on which a pattern to be transferred is formed is loaded on reticle stage RST by a reticle loader (not shown). Further, the wafer W to be exposed is loaded on the carry-in arm 36 by the transfer arm 44 (see FIG. 4).

Next, in step 103, the main controller 20 controls the vertical movement / rotation mechanism 38 via the pre-alignment controller 34 to move the carry-in arm 36 in the Z-axis direction, Is the CCD camera 40a,
The height position of the observation surface is defined by 40b and 40c.

Subsequently, at step 104, CC
The vicinity of the outer edge of the wafer W is imaged by the D cameras 40a, 40b, and 40c. The image data IMD <b> 1 of the wafer W thus imaged is supplied to the main controller 20. In the main control device 20, the imaging data collection device 51 receives the imaging data IMD1, and stores the received data in the imaging data storage area 55.

Next, at step 105, the control device 59 reads out the image data relating to the wafer W from the image data storage area 55 and processes the read data.
Wafer W including orientation flat described later)
And the position of the notch N (or the orientation flat) are detected, and the center position Q _W , the radius R _W , and the center position offset (Δ) which are the shape parameters of the wafer W are detected.
X _W , ΔY _W ) and the rotation angle θ _W about the Z axis.
Then, based on the measured rotation angle θ _W of the wafer W about the Z axis, the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34 as necessary, and Is driven to rotate. Subsequently, the control device 59 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34, drives the loading arm 36, and loads the wafer W into the wafer holder 18.

The correction of the center position offset (ΔX _W , ΔY _W ) measured as described above may be reflected on the load position of the wafer W, or may be reflected upon fine alignment described later. .

Next, in step 106, control device 59 performs reticle alignment using a reference mark plate (not shown) arranged on wafer stage WST, and measurement of a baseline amount using wafer alignment sensor ALG. Perform preparatory work. Further, when the exposure on the wafer W is the exposure of the second layer or later, in order to form a circuit pattern with high accuracy of superimposition with the already formed circuit pattern, based on the shape measurement result of the wafer W described above, Fine alignment is performed. That is, the positional relationship between the reference coordinate system that regulates the movement of the wafer W, ie, the movement of the wafer stage WST, and the arrangement coordinate system related to the arrangement of the circuit patterns on the wafer W, that is, the arrangement of the shot areas, is determined using the wafer alignment sensor ALG. Detected with high accuracy.

Next, in step 107, the first layer is exposed. In this exposure operation, first,
Wafer stage WST is moved so that the XY position of wafer W becomes the scanning start position for exposing the first shot area (first shot) on wafer W.
This movement is based on the result of the above-described shape measurement of the wafer W, position information (speed information) from the wafer interferometer 24, and the like (for the exposure of the second and subsequent layers, the positional relationship between the reference coordinate system and the array coordinate system) Is performed by the main controller 20 via the stage controller 19 and the wafer driving device 15 based on the detection result (position information (speed information) and the like from the wafer interferometer 24). At the same time, reticle stage RST is moved such that the XY position of reticle R becomes the scanning start position. This movement is performed by the main controller 20 by the stage controller 19.
And a reticle driving unit (not shown).

Next, the stage controller 19 responds to an instruction from the main controller 20 so that the Z position information of the wafer detected by the multipoint focus position detecting system and the reticle R measured by the reticle interferometer 16 are obtained. XY location information,
Based on the XY position information of the wafer W measured by the wafer interferometer 24, the reticle R and the wafer W are moved while adjusting the surface position of the wafer W via a reticle driving unit and a wafer driving device 15 (not shown). Scanning exposure is performed by relative movement.

When the exposure of the first shot area is completed, wafer stage WST is moved so that the scanning start position for the exposure of the next shot area is moved, and the XY position of reticle R is changed to the scanning start position. Reticle stage RST is moved to a position. Then, the scanning exposure for the shot area is performed in the same manner as the above-described first shot area. Thereafter, scanning exposure is performed for each shot area in the same manner, and the exposure is completed.

Then, in step 108, the wafer W that has been exposed is unloaded from the wafer holder 18 by the carry-out arm 42.

As described above, according to the present embodiment, the first reference mark FSM on the calibration reference wafer SW is provided.
a, FSMb, and FSMc are captured, and the first mark FT is determined by the unique mark STM in each captured image.
By detecting the positions of a plurality of grid points whose positions in M are specified, the CCD cameras 40a, 40b, 40
c Each of the imaging magnification, the rotation amount of the imaging visual field, the center position of the imaging visual field, the rotation center and the rotation rate of the transfer arm 36, and the like can be calibrated according to the drawing accuracy of the first mark FTM.

Since the first pattern FTM is a checkerboard pattern, grid points (contact points between the vapor deposition portions CP)
Is used as a shape feature point, the position can be detected easily and accurately.

The first reference marks FSMa, FSMa
b, FSMC are large deviation marks TTM1, TTM2, T
Because we decided to have TM3, unique mark STM
Is not within the field of view of the CCD cameras 40a, 40b, 40c, the large displacement marks TTM1, TTM
If TM2 and TTM3 are in the field of view, the large displacement marks TTM1, TTM2, and TTM3 in the field of view.
Field of view and unique mark ST based on the detection position of
The positional relationship with M can be specified. Therefore, by moving the reference wafer SW relatively to the imaging field of view based on the specified positional relationship, the first reference mark F is placed in a state where the unique mark STM is within the imaging field of view.
SMa, FSMb, and FSMc can be imaged.

The second fiducial marks SSMa, SSM
By measuring b, SSMc, and SSMd, the rotation amount of the reference wafer SW about the central axis can be measured. Therefore, the calibration can be performed with high accuracy by considering the measured rotation amount of the reference wafer SW around the central axis. In adjusting the position of the reference wafer SW, the XY position is adjusted by controlling the drive of the wafer stage WST, and the rotational movement of the reference wafer SW about the central axis is performed by controlling the rotation of the loading arm 36. The position of the SW in the direction of three degrees of freedom can be adjusted.

Also, the wafer holder 18 and the loading arm 36
Since the reference position of the displacement of the wafer SW reference wafer SW that may occur during transfer of (X-direction displacement D _X, Y-direction displacement D _Y, rotational displacement beta) relating to correction between the very accurate Can be calibrated well.

Also, the cross marks JMa, JMb, JMc for adjusting the visual field area on the tool wafer JW are displayed on the CCD camera 40.
Images are taken by the cameras 40a, 40b, and 40c, and the positions of the visual field regions of the CCD cameras 40a, 40b, and 40c are adjusted based on the image pickup results, so that the calibration operation can proceed smoothly.

Since the position information of the wafer W is detected using a CCD camera or the like calibrated using the reference wafer SW, the position information of the wafer W (for example, the center position of the wafer) is detected with high accuracy. be able to.

The wafer W whose position is measured with high accuracy
Is mounted on the wafer holder 18 on the wafer stage WST, so that the position of the wafer W can be controlled with high accuracy, and the pattern can be transferred onto the substrate with high accuracy.

In the above embodiment, the wafer diameter is 1
Although the case where the wafer is loaded with 2 inches and the notch in the direction of 6 o'clock has been described, the present invention is also applied to the case where the wafer is 12 inches in diameter and loaded with the notch in the direction of 3 o'clock. can do. In such a case, as shown in FIG.
And the first fiducial marks FTMd, FTM on the outer edge in the 4:30 direction.
Using the reference wafer on which TMe and FTMc are formed, calibration for the corresponding CCD camera and carry-in arm is performed.

Further, in order to correspond to the notch positions in the 6 o'clock direction and the 3 o'clock direction, the 6 o'clock direction, the 7:30 o'clock direction,
First reference marks FTMa, FTMb, FTMc, and FT are provided at five outer edges in the half-hour direction, the three-hour direction, and the half-hour direction.
Using the reference wafer on which Md and FTMe are formed, calibration for the corresponding CCD camera and loading arm can also be performed.

In the above embodiment, the wafer diameter is set to 1
Although 2 inches is used, the present invention can be applied to a case where the wafer diameter is 8 inches. Here, the notch position is 6
In the hour direction, as shown in FIG. 19A, first reference marks FSMa ′, FSMb ′, and FSMc ′ are formed at the outer edges of the 6 o'clock direction, the 10:30 direction, and the 1:30 direction. The reference wafer SW ′ may be used. When the notch position is in the 3 o'clock direction, as shown in FIG. 19B, the first reference marks FSMd 'and FSMb' are located at the outer edges of the 3 o'clock direction, the 10:30 o'clock direction, and the 7:30 o'clock direction. , FSMe '
May be used. Furthermore, in order to correspond to the notch positions of either the 6 o'clock direction and the 3 o'clock direction, the 6 o'clock direction, the 10:30 direction, the 1:30 direction,
The first fiducial mark F is located at the outer edge of the direction of 3 o'clock and 7:30.
SMa ', FSMb', FSMc ', FSMd', FS
What is necessary is just to use the reference wafer SW 'in which Me' was formed. And a CCD provided in accordance with the first fiducial mark.
Calibration for the camera and the loading arm may be performed.

Further, in the above embodiment, the description has been made of a wafer having a notch, but the present invention can be applied to a wafer having an orientation flat. In such a case, a reference wafer having a first reference mark formed at both ends of the orientation flat and at another location (for example, when the orientation flat is in the 6 o'clock direction, the outer edge in the 3 o'clock direction) is used. Calibration for the corresponding CCD camera and carry-in arm may be performed.

In the above embodiment, a checkered pattern mark is used as the first mark. However, if the mark is a mark in which shape characteristic points whose two-dimensional positions can be detected are distributed two-dimensionally,
Other marks can be employed.

Although two small circle marks are used as unique marks, any other mark can be used as long as the position of the shape characteristic point in the first mark can be specified.

Although the three large circle marks are used as the large displacement marks, other marks can be used as long as the positional relationship with the unique mark is fixed.

It is also possible to repeatedly load the reference wafer and adjust the load position of the wafer stage so that the average of the loading positions falls within the allowable value.

In order to optimize the rotation angle correction amount β at the time of delivery and to analyze the calibration data, one set of images used for calibration (for example, 6 images at one location × 3 cameras = 18)
Sheets: Six images at one location, one image at the time of measuring the camera magnification, rotation, and center position, and five images at the rotation center and rotation rate measurement of the loading arm (when the rotation measurement position is at five points) And the measurement result of each image may be saved as a log file. In such a case, only the calibration calculation can be performed by changing the β value and using the measurement result of the grid point of the first mark in each image. The image log file can be used for image quality evaluation. Thereby, optimization of β and data analysis at the time of trouble can be performed without operating the actual machine.

In the above-described embodiment, the shift amounts D _X , D _Y , and β which may occur when the reference wafer SW is transferred from the wafer holder 18 to the carry-in arm 36 are determined by optimizing the shift amounts. It is also possible to use a default value predetermined by design or rule of thumb.
For example, when design values are used, D _X = 0,
D _Y = 0 and β = 0 can be set as default values.

In the above embodiments, the case of a scanning type exposure apparatus has been described. However, the present invention relates to a reduced projection exposure apparatus using ultraviolet light as a light source, and a reduced projection exposure apparatus using soft X-rays having a wavelength of about 10 nm as a light source. X with light source around 1nm wavelength
It can be applied to any wafer exposure apparatus such as a line exposure apparatus, an exposure apparatus using an EB (electron beam) or an ion beam, and a liquid crystal exposure apparatus. Also, step and repeat machines,
It does not matter whether it is a step-and-scan machine or a step-and-stitch machine.

[0193]

As described above, by using the calibration reference wafer of the present invention, it is possible to accurately calibrate an imaging device or the like.

Further, according to the calibration method of the present invention, since the imaging device and the like are calibrated by the calibration reference wafer of the present invention,
It is possible to calibrate an imaging device or the like with high accuracy.

Further, according to the position detecting method of the present invention, since the position of the wafer is detected by an image pickup device or the like calibrated by using the calibration method of the present invention, the position of the wafer can be detected with high accuracy. .

Further, according to the position detecting device of the present invention, the position of the object is detected by using the position detecting method of the present invention, so that the position of the wafer can be accurately detected.

Further, according to the exposure apparatus of the present invention, the position of the substrate can be accurately measured by the position detecting apparatus of the present invention, so that the position of the substrate can be controlled with high accuracy, and thus the pattern can be accurately detected. It can be transferred to a substrate.

[Brief description of the drawings]

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

FIGS. 2A to 2C are diagrams for explaining the configurations of a wafer stage and a wafer holder of FIG. 1;

FIG. 3 is a perspective view showing the vicinity of a wafer supported by a loading arm during pre-alignment.

FIG. 4 is a diagram for explaining an arrangement of components relating to loading and unloading of a wafer.

FIG. 5 is a block diagram illustrating a configuration of a main control device.

FIG. 6 is a flowchart for explaining the exposure operation of FIG. 1;

FIG. 7 is a flowchart illustrating a process in a calibration subroutine of FIG. 6;

FIGS. 8A to 8C are views for explaining the relationship between a monitor coordinate system and a stage coordinate system.

FIG. 9 is a flowchart illustrating a process of a camera visual field position adjustment subroutine of FIG. 7;

FIGS. 10A and 10B are views for explaining a cross mark on a tool wafer.

FIG. 11 is a perspective view showing the vicinity of the tool wafer when imaging the tool wafer.

FIG. 12 is a flowchart illustrating a process of a reference wafer position adjustment subroutine of FIG. 7;

FIG. 13 is a diagram for explaining mark positions on a reference wafer.

FIG. 14 is a diagram for explaining a configuration of a basic mark.

FIGS. 15A to 15C are diagrams showing a first fiducial mark formed on a fiducial wafer.

FIG. 16 is a perspective view showing the vicinity of a tool wafer when imaging a reference wafer.

FIGS. 17A to 17C are diagrams for explaining an imaging result of a reference wafer.

FIG. 18 is a diagram showing a formation position of a first fiducial mark on a fiducial wafer to be calibrated for a 12-inch wafer having a notch at 3 o'clock.

FIGS. 19A and 19B are diagrams showing positions where first reference marks are formed on a reference wafer to be calibrated for an 8-inch wafer. FIGS.

FIG. 20A and FIG. 20B are views for explaining a conventional calibration method.

[Explanation of symbols]

18 wafer holder (part of stage device), 36 carry-in arm (support device), 40a, 40b, 40c CC
D camera (imaging device), 53 ... reference wafer position adjustment device (reference wafer position adjustment device for calibration: part of calibration device),
54: Calibration amount calculating device (part of the calibrating device), 59: Control device (viewing area position adjusting device), FSMa, FSMb,
FSMC: First fiducial mark, FTMa, FTMb, FT
Mc: first mark, SSMa, SSMb, SSMC, S
SMd: second reference mark, STM: unique mark (second mark), SW: reference wafer (reference wafer for calibration),
TTM1, TTM2, TTM3: large deviation mark (third mark), W: wafer, WST: wafer stage (part of stage device).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA12 BB03 BB27 CC19 FF04 JJ03 JJ05 JJ09 JJ26 QQ31 5F046 AA20 DB05 DB10 EB01 EC05 FA10 FC06 FC08

Claims (16)

[Claims] 1. A calibration reference wafer used for calibrating a position detection device that detects position information of the wafer based on imaging results of three or more imaging target areas near an outer edge of the wafer, The first reference mark is formed of a substrate having a first fiducial mark formed in each of the target areas, and each of the first fiducial marks has a shape feature point arranged at a predetermined distance in each of two directions intersecting each other. A mark and a second for specifying a position of each of the shape feature points in the first mark.
And a reference wafer for calibration. 2. The calibration reference wafer according to claim 1, wherein the first mark has a plurality of rectangular patterns arranged in a checkered pattern. 3. The method according to claim 2, wherein the first reference mark further includes a third mark for specifying a positional relationship between the imaging field of view and the substrate when the second mark is outside the imaging field of view. The calibration reference wafer according to claim 1. 4. The substrate according to claim 1, further comprising a second reference mark on a surface of the substrate, the second reference mark being a reference for a rotation amount about a central axis of the substrate. 2. The reference wafer for calibration according to 1. 5. A semiconductor device according to claim 3, wherein said wafer is supported by a supporting device rotatable about a normal to said wafer supporting surface.
A method of calibrating a position detection device that detects position information of the wafer based on imaging results of three or more imaging devices arranged in accordance with each of the above imaging target regions, the method being supported by the support device. The calibration reference wafer according to any one of Items 1 to 3, the imaging device captures an image, and based on a result of the imaging, the first mark and the second mark correspond to a visual field of the imaging device. A reference wafer position adjusting step of adjusting the position of the calibration reference wafer so as to fall within the range; and imaging the first mark and the second mark relating to the calibration reference wafer adjusted in the reference wafer position adjusting step. Calibrating at least one of the imaging device and the support device based on the result. 6. The calibration reference wafer further includes a second reference mark serving as a reference for an amount of rotation of the calibration reference wafer about a central axis, wherein the calibration step adjusts the reference wafer position. Observing the second reference mark of the calibration reference wafer whose position has been adjusted in the step, measuring the amount of rotation of the calibration reference wafer around the central axis, and measuring the measurement result and the first reference regarding the calibration reference wafer. The calibration method according to claim 5, wherein the imaging device and the support device are calibrated based on a mark and an imaging result of the second mark. 7. The imaging device according to claim 5, wherein the calibration of the imaging device is at least one of an imaging magnification, a rotation amount of an imaging visual field, and a center position of the imaging visual field in the imaging device. Calibration method. 8. The method according to claim 5, wherein the calibration of the support device is at least one of a relationship between a measured rotation amount and an actual rotation amount and a rotation center position of the support device. The calibration method according to claim 1. 9. In the reference wafer position adjusting step, adjusting the translation position of the calibration reference wafer along a plane substantially parallel to the surface of the calibration reference wafer includes adjusting the calibration reference wafer from the support device. The calibration method according to any one of claims 5 to 8, wherein the adjustment is performed by the received stage device, and the adjustment of the rotational position of the calibration reference wafer around the central axis is performed by the support device. . 10. In the calibration step, it is preferable that the calibration step corrects a positional shift of the calibration reference wafer that may occur when the calibration reference wafer is transferred between the stage device and the support device. The calibration method according to claim 9, wherein: 11. Prior to the reference wafer position adjusting step, a field-of-view adjustment mark is formed in each of the imaging target areas, and a tool wafer supported by the support device is imaged by the imaging device. 11. A visual field position adjusting step of adjusting a position of a visual field of the imaging device based on the image data.
The calibration method according to any one of claims 1 to 4. 12. An imaging apparatus according to claim 1, wherein said at least three imaging devices are arranged in accordance with at least three imaging target regions near an outer edge of the wafer supported by a supporting device rotatable around a normal line of the wafer supporting surface. And a position detection method for detecting position information of the wafer, wherein the calibration method according to any one of claims 5 to 11 performs a calibration of the imaging device and the support device. A wafer supporting step of supporting the wafer by the supporting device; a wafer imaging step of imaging the wafer supported by the supporting device by the imaging device; and a process of imaging the wafer based on an imaging result in the wafer imaging step. A wafer position information detecting step of obtaining position information. 13. A position detecting device for detecting a position of the wafer based on an imaging result of three or more imaging target regions near an outer edge of the wafer, the device supporting the wafer, and a position detecting device which rotates around a normal line of a wafer supporting surface. A rotatable supporting device; three or more imaging devices arranged in accordance with each of three or more imaging target regions near an outer edge of the wafer supported by the supporting device; and a position of a visual field region of the imaging device. A visual field region position adjusting device to be adjusted; and the imaging device and the support based on an imaging result of the calibration reference wafer according to any one of claims 1 to 3 supported by the support device. A calibration device for calibrating the device. 14. The calibration device, comprising: a calibration reference wafer position adjustment device for adjusting a position of the calibration reference wafer; and the imaging of the calibration reference wafer adjusted by the calibration reference wafer position adjustment device. 14. The position detecting device according to claim 13, further comprising: a calibration amount calculating device that calculates a calibration amount for the imaging device and the support device based on a result of imaging by the device. 15. The calibration reference wafer further includes a second reference mark for measuring an amount of rotation of the calibration reference wafer around a central axis, wherein the calibration device is configured to: The position detecting device according to claim 14, further comprising a rotation amount measuring device that observes the second reference mark on the wafer and measures a rotation amount of the calibration reference wafer around a central axis. 16. An exposure apparatus for irradiating a substrate with an exposure beam to form a predetermined pattern on the substrate, wherein the position information of the substrate is detected. An exposure apparatus comprising: a position detecting device; and a stage device having a stage on which the substrate whose position information has been detected by the position detecting device is mounted.