JP2002280287A - Method and device for detecting position, method and device for exposure, and method of manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the positional information on an object with accuracy. SOLUTION: After background members 42a, 42b and 42c, respectively carrying such patterns that do not exist on the surface of the object W supported by a supporting member 36, are arranged on the back side of the object W, the object W and background members 42a-42c are irradiate with light. Successively, the images of the surface of the object W and the background members 42a-42c, formed of reflected light rays from the surface of the object W and members 42a-42c, are photographed up by means of imaging devices 40a, 40b and 40c. Then the positional information on the boundary between the object region and background member region is found, based on the difference between the image patterns in the areas. Consequently, the positional information on the object W can be detected with accuracy, without adopting transmitted-light illuminating system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a position detection method, a position detection device, an exposure method, an exposure device, and a device manufacturing method, and more particularly, to a position detection method and a position detection device for detecting position information of an object. The present invention relates to an exposure method and an exposure apparatus for detecting position information of an object to be exposed using the position detection method, and a device manufacturing method for performing exposure using the exposure method in a lithography process.

[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. An exposure apparatus for forming a wafer or a glass plate or the like (hereinafter, appropriately referred to as a “substrate or a wafer”) coated with a substrate or the like is used. 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 reason, the so-called enhanced global alignment (hereinafter referred to as “EG
A ”) is widely used. In this EGA, several fine alignment marks (detailed alignment marks transferred together with the circuit pattern) in the wafer are measured, and the arrangement coordinates of each shot area are obtained by least squares approximation or the like. Then, at the time of exposure, a stepping operation is performed by using the calculation result, depending on the accuracy of the wafer stage.

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.

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. In imaging for such pre-alignment, a wafer placed on a vertically movable and rotatable center table provided on the wafer stage is moved from the back side using a light source provided in the wafer stage. A transmissive illumination method of illuminating and imaging the wafer from the front side of the wafer has been employed.

[0007]

In the above-described conventional pre-alignment, since the light source inside the wafer stage is provided, the heat generated due to the light emission of the light source causes the deformation of the wafer stage. For this reason, the position detection accuracy of the wafer due to the pre-alignment has been reduced.

Further, if a light source and a vertically movable center table are provided in the wafer holder, it is necessary to house a light source and a vertically moving mechanism of the center table inside the wafer holder, which leads to an increase in the size of the wafer holder. . Further, in recent years, demands for obtaining pattern information drawn on the wafer surface have been increasing. Acquisition of such pattern information on the wafer surface has been extremely difficult to achieve by using a transmission illumination method.

For this reason, a new wafer position detection technique employing a method different from the transmitted light illumination method without lowering the wafer position detection accuracy 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 position detection method capable of accurately detecting the position of an object without employing a transmitted light illumination method. It is to provide a method and a position detecting device.

It is a second object of the present invention to provide an exposure method and an exposure apparatus which can form a predetermined pattern on a substrate surface with high accuracy.

A third object of the present invention is to provide a device manufacturing method capable of producing a highly integrated device having a fine pattern.

[0013]

A position detecting method according to the present invention is a position detecting method for detecting position information of an object (W), wherein the position information does not exist on the back side of the object and on the surface of the object. The background member (42a, 42) on which the pattern is formed
b, 42c); a second step of irradiating illumination light from the surface side of the object; and a position of an outer edge of the object based on light reflected from the surface of the object and the background member. A third step of obtaining information. Here, the “surface of the object” refers to the surface on the front side of the object. For example, in the above-described wafer, the surface of the wafer refers to a surface to which a pattern is to be transferred or a surface to which a pattern is transferred. In this specification, the term “surface” is used in this sense.

According to this, after the background member is arranged on the back side of the object in the first step, the object and the background member are irradiated with the illumination light from the front side of the object in the second step. Then, in a third step, position information of the outer edge of the object is obtained based on the reflected light from the surface of the object and the background member. That is, the surface of the object and the background member are observed by the epi-illumination method. At this time, since a pattern that does not exist on the surface of the object is formed on the background member, the surface region of the object and the background member region in the observation result can be distinguished, and the position information of the outer edge of the object is obtained. be able to. Therefore, the position information of the object can be accurately obtained without employing the transmitted light illumination method.

According to the position detecting method of the present invention, the surface of the object can be made substantially flat, and the illumination light can be made to enter the plane portion of the surface of the object almost perpendicularly. That is, in the position detection method of the present invention, a so-called vertical epi-illumination method can be adopted.

Further, in the position detecting method of the present invention, the surface of the object can be made substantially flat, and the illumination light can be obliquely incident on a plane portion of the surface of the object. That is,
In the position detecting method of the present invention, a so-called oblique incident illumination method can be adopted.

Further, according to the position detecting method of the present invention, the illumination light can be diffused light.

Further, in the position detecting method according to the present invention, the third step is a fourth step of capturing an image of the surface of the object and the background member formed by the reflected light; And image processing to obtain positional information of the outer edge of the object. Here, texture analysis processing can be performed as the image processing.

The position detecting device of the present invention is a position detecting device for detecting position information of an object (W), comprising a support member (36) for supporting the object; and a pattern not existing on the surface of the object. (42a, 42)
b, 42c); an irradiation system (51, 5) for irradiating illumination light from the front surface side of the object in which the background member is disposed on the back surface side.
2, 54); and a processing device (56, 57, 61) for processing reflected light from the surface of the object and the background member to obtain positional information of an outer edge of the object.

According to this, after the background member is arranged on the back side of the object supported by the support member, the illumination system irradiates the object and the background member with illumination light from the front side of the object. Then, the processing device obtains position information of the outer edge of the object based on the reflected light from the surface of the object and the background member. That is, the position detection device of the present invention detects the position information of the object using the position detection method of the present invention. Therefore, the position information of the object can be accurately obtained without employing the transmitted light illumination method.

In the position detecting device of the present invention, the background member driving device (45a, 45b, 45b, 45b, 45b) moves the background member on the back side of the object supported by the support member in a direction approaching and moving away from the object. 45c).

In the position detecting device according to the present invention, the background member may be provided on the support member.

Further, in the position detecting device of the present invention, the irradiation system includes a light source for generating the illumination light and a light diffusion member for diffusing the illumination light. Can be.

In the position detecting device according to the present invention, the processing device may form an image forming optical system (56) for forming an image of the reflected light.
An imaging device (57) that captures an image formed by the imaging optical system; an image processing device (63) that performs image processing on an imaging result obtained by the imaging device to obtain positional information of an outer edge of the object. A configuration comprising:

An exposure method according to the present invention is an exposure method in which a predetermined pattern is formed on the substrate by irradiating the substrate (W) with an exposure beam. And a pattern forming step of controlling the position of the substrate based on the position information of the substrate detected in the position detecting step and forming the predetermined pattern on the substrate. Including.

According to this, the position information of the substrate is detected by using the position detecting method of the present invention. Then, a predetermined pattern is formed on the substrate while controlling the position of the substrate based on the detected position information of the substrate. Therefore,
A predetermined pattern can be accurately formed in the divided area.

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

According to this, the substrate whose position information is detected with high precision 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.

A device manufacturing method according to the present invention is characterized in that, in the device manufacturing method including the lithography step, exposure is performed in the lithography step using the exposure method according to the present invention. According to this, by performing exposure using the exposure method of the present invention, a predetermined pattern can be formed on a substrate with high accuracy, so that the productivity of a highly integrated device having a fine circuit pattern can be improved. Can be improved.

[0030]

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

FIG. 1 shows a 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 device on which a wafer W as a substrate is mounted, and a control system thereof.

The illumination system 12 comprises 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 uniform illumination distribution with a substantially uniform illuminance distribution by an illuminance uniforming 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, etc.) 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 illumination area IAR on R can be set to any shape and size.

Here, each of the above driving units in the illumination system, that is, the variable ND filter, the reticle blind, and the like are controlled by an illumination control instruction signal LCD from the main control system 20.

The reticle stage RST is disposed 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 provided with an optical system of an illumination system (hereinafter, referred to as an “illumination optical system”) for positioning reticle R by a reticle stage driving unit (not shown) including a magnetic levitation type two-dimensional linear actuator. In a plane perpendicular to the optical axis (coincident with the optical axis AX of the projection optical system PL described later)
Two-dimensionally (in the Y plane) (in the X axis direction, Y perpendicular to this direction)
In the axial direction and in the direction of rotation about the Z axis perpendicular to the XY plane)
In addition to being capable of minute driving, it can be driven at a designated scanning speed in a predetermined scanning direction (here, Y direction). This reticle stage RST has a reticle R
Has a movement stroke in the Y direction that can at least cross the optical axis of the illumination optical system. The reticle base 13 is provided with a main body column 93 described later.
The top 91 of the gantry 91 is configured.

The side surface of the reticle stage RST is mirror-finished and has a reflecting 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 (velocity information) RPV of the reticle stage RST from the reticle interferometer 16 is sent to the stage control device 19 and the main control system 20 via this. The stage control device 19 controls the reticle stage RST via a reticle stage driving unit (not shown) based on the position information (speed information) RPV of the reticle stage RST in response to an instruction from the main control system 20 based on the stage control data SCD. Drive.

The projection optical system PL is arranged below the reticle stage RST in FIG. The direction of the optical axis AX (coincident with the optical axis of the illumination optical system) of the projection optical system PL is defined as the Z-axis direction, and here, at predetermined intervals along the direction of the optical axis AX so as to provide a telecentric optical arrangement on both sides. A refractive optical system including a plurality of lens elements arranged 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 main body column 93 comprises a lens barrel base 92 horizontally supported by a vibration isolator 94 fixed to the floor,
And a gantry 91 fixed to the upper surface of the lens barrel base 92. The lens barrel base 92 has a circular opening in the center at the center thereof, and a projection optical system PL is formed in the opening.
Are inserted from above. A flange 98 is provided at the center of the projection optical system PL in the height direction. The projection optical system PL is supported by the lens barrel base 92 from below through the flange 98.

The gantry 91 has four legs arranged vertically on the upper surface of the lens barrel base 92 so as to surround the projection optical system PL, and a space between the upper ends of these four legs. , That is, a reticle base 13.

The wafer stage WST includes a wafer base plate 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.

The 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) is mirror-finished on each side.
The position of the wafer stage WST in the XY plane is always detected with a resolution of, for example, about 0.5 to 1 nm by the wafer interferometer 24 fixed to.

Here, actually, 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. In FIG. 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. Position information (or speed information) WPV of wafer stage WST is sent to stage control device 19 and main control system 20 via this. The stage control device 19 is configured to control the wafer driving device 1 based on the position information (or speed information) WPV in response to an instruction from the main control system 20 based on the stage control data SCD.
5, the wafer stage WST is controlled.

Further, in exposure apparatus 100 of the present embodiment, alignment marks (wafer marks) attached to each shot area on wafer W on the side surface of projection optical system PL.
Is provided with an off-axis type alignment system (not shown) for detecting the position. Such an alignment system includes, for example, an image-forming type alignment sensor of an image processing system. The measurement result data of the alignment sensor is sent to the main control system 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. An AF is provided.
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. Is used to drive the wafer holder 18 in the Z direction and the tilt direction so that the wafer W and the projection optical system PL maintain a predetermined distance from each other. The wafer position information from the multipoint focus position detection system AF is sent to the stage control device 19 via the main control system 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.

Base line measurement reference marks and other reference marks for measuring the relative positional relationship between the position of the detection center of the alignment sensor and the position of the projected image of the reticle pattern are formed on wafer stage WST. A reference plate (not shown) is provided.

As shown in FIGS. 2A to 2C, the lower part (side surface of the wafer stage) of the wafer holder 18 on the wafer stage WST has the arc-shaped portions at both ends in the X direction removed. It has a circular shape. Notches 30a and 30b are formed at the + X direction end on the upper surface (wafer mounting surface) side of the wafer holder 18, and-
A notch 30c is formed at the end in the X direction. Wafer stage WST below notches 30a, 30b
A groove 31a extending to the + Y direction to the edge of wafer stage WST is formed on the surface of
A groove 3 extending in the + Y direction to the edge of wafer stage WST on the surface of wafer stage WST below
1b is formed. This set of notches 30a, 3
Ob, 30c and a pair 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 is provided at the wafer transfer position. The wafer pre-alignment device 32 is attached to a lens barrel surface plate 92, and the imaging result of the wafer W is used as imaging data IMD as the main control system 20.
To supply.

FIG. 3 shows a wafer pre-alignment apparatus 32.
As shown in (A), a pre-alignment control device 34 fixed to the lens barrel surface plate 92 and a wafer carry-in arm (hereinafter, referred to as a “load-in arm”) provided below the pre-alignment control device 34 and serving as a support member. ), A vertical movement / rotation mechanism 38 that vertically moves and rotates while supporting the 36, and three CCD cameras 4 disposed above the carry-in arm 36.
0a, 40b, and 40c. Further, the wafer pre-alignment device 32 is shown in FIGS. 3 (A) and 3 (B).
The background plate 4 as a background member as generally shown in FIG.
2a, 42b, 42c and the background plates 42a, 42b,
And linear motors 45a, 45b, and 45c as background member driving devices for moving 42c in a direction to approach or separate from the wafer W 'in the XY plane on the back surface side of the wafer W' supported by the loading arm 36. Have.
The main control system 2 is provided inside the pre-alignment control device 34.
0, the CCD cameras 40a, 40b, 4
An image signal processing system that collects image signals from 0c and transmits the collected signals to the main control system 20, a control system of the vertical movement / rotation mechanism 38, a control system of the linear motors 45a, 45b, and 45c are built in.

The linear motor 45a includes a stator 46a
And a mover 47a. Stator 46a
Is fixed to a motor support member (not shown) that extends vertically downward from the lens barrel base 92, and extends in front of the wafer W ′ in the −Y direction. A background plate 42a is fixed to the mover 47a, and ± Y
With the movement in the direction, the background plate 42a also moves in the ± Y direction. And the mover 47a is most -Y
When the movable plate 47a is moved in the + Y direction, a part of the background plate 42a on the −Y direction side faces the back surface of the wafer W ′. It is retracted from the back side of W '.

The linear motor 45b includes a stator 46b
And a mover 47b. Stator 46b
Is fixed to the lens barrel surface plate 92, and is fixed to the motor support member 43b extending vertically downward, and extends in front of the wafer W 'along the + X direction. In addition, the mover 47
The background plate 42b is fixed to b, and the background plate 42b also moves in the ± X direction as the mover 47b moves in the ± X direction. When the mover 47b moves in the + X direction most, a part of the background plate 42b on the + X direction side faces the back surface of the wafer W '.
When b moves in the −X direction most, the background plate 42 b is completely retracted from the back surface side of the wafer W ′.

The linear motor 45c includes a stator 46c
And a mover 47c. Stator 46c
Is fixed to a lens barrel base 92 and is fixed to a motor support member 43c extending vertically downward, and extends in front of the wafer W ′ in the −X direction. In addition, the mover 47
A background plate 42c is fixed to c, and the background plate 42c also moves in the ± X direction as the mover 47c moves in the ± X direction. Then, when the mover 47c moves the most in the −X direction, a part of the background plate 42c on the −X direction side faces the back surface of the wafer W ′.
When b moves in the + X direction most, the background plate 42c is completely retracted from the back surface side of the wafer W '.

A periodic two-dimensional polka dot pattern is formed on the upper surface (front surface) of each of the background plates 42a, 42b, and 42c, as typically shown in FIG. 4A for the background plate 42a. Such a polka dot pattern is selected as a pattern that cannot be a circuit pattern formed on the upper surface (front surface) of the wafer W ′. In addition,
As a pattern that can never be a circuit pattern formed on the upper surface (front surface) of the wafer W ′, in addition to the polka dot pattern of FIG. 4A, a checker (checker flag) pattern shown in FIG. The oblique stripe pattern shown in FIG. 4C, the oblique line pattern shown in FIG. 4D, the oblique lattice pattern shown in FIG. The reason why the patterns shown in FIGS. 4C to 4E can be adopted is that a linear pattern in a circuit pattern generally formed on a wafer is parallel to the X direction or the Y direction.

The CCD cameras 40a, 40b, 40c
Are for detecting the outer edges of the wafer W supported by the carry-in arm 36, respectively. CCD camera 40a,
Here, as shown in the perspective view of FIG. 6, the outer edges 40b and 40c of the 12-inch wafer W 'supported by the loading arm 36 as a supporting device are arranged at positions where the outer edges including the notch N can be imaged. I have. Among them, the central CCD camera 40a detects the notch. Note that C
At the time of imaging by the CD cameras 40a, 40b, 40c,
A part of the background plates 42a, 42b, 42c is arranged so as to face the lower surface (back surface) of the wafer W '(see FIG. 6).

The CCD cameras 40a, 40b, 40c
As typically shown in FIG. 5 for the CCD camera 40a, a light source 51, a collimator lens 52, a half mirror 54, a mirror 55, an imaging optical system 56, and a CCD
It is configured to include the imaging element 57. Here, this C
Each component of the CD camera 40a will be described together with its operation.

The observation illumination light emitted from the light source 51 is
The light is collimated through the collimator lens 52. A part of the parallel light is bent downward by the half mirror 54 and irradiated on the upper surface (pattern forming surface) of the wafer W ′ and the upper surface (pattern forming surface) of the background plate 42a.

The observation illumination light is reflected by the upper surface of the wafer W 'and the upper surface of the background plate 42a. Part of the reflected light passes through the half mirror 54 and is reflected by the mirror 55, and then passes through the imaging optical system 56, so that the upper surface image of the wafer W ′ and the background plate 42
A top image of a is formed. The CCD image pickup device 57 picks up the image thus formed on the light receiving surface, and sends out the image pickup result to the pre-alignment control device 34 as image data IMDa.

As the imaging optical system 56, a telecentric optical system on the object side is used. This is because the image height (the distance from the optical axis to the image point) changes when the object point moves in the optical axis direction in a general imaging system, but in the case of a telecentric optical system on the object side, the image height changes on the observation surface. This is because the image is blurred but the image height does not change.

By the way, when the principal ray is inclined, “(distance between wafer W ′ and background plate 42a) × (inclination of principal ray)”
(For example, a distance of 2 mm between the wafer W ′ and the background plate 42a,
When the inclination of the principal ray is 2.5 mrad, the detection result of the outer edge position of the wafer W 'shifts by 5 μm). For this reason,
It is necessary to adjust the telecentricity of the imaging optical system 56 according to the detection accuracy required for detecting the outer edge position of the wafer W ′. The same consideration is required for the inclination of the background plate. Note that each of the movers 47a to 47c may be provided with a tilt drive unit for tilting the background plates 42a to 42c.

The depth of focus of the imaging optical system 56 is deeper including the distance between the surface of the wafer W 'and the surface of the background plate 42a.

The focal position, the upper surface of the wafer W 'and the background plate 4 are determined in accordance with the depth of focus and the required detection accuracy.
It is preferable to be able to arbitrarily set the interval with 2a.
Usually, the focal position is adjusted to the upper surface of the wafer W ′.

In this embodiment, the loading arm 36
Has a T-shape in plan view, and 3 in the T-shape.
Three finger portions extend vertically downward from each of the two end portions. Then, a wafer W is placed on the lower end of the three fingers.
Is provided.

Further, as shown in FIG. 7, the exposure apparatus 100 of this embodiment has a wafer unloading arm (hereinafter, “unloading arm”) for unloading the wafer on 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. 7, 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.

The main control system 20 includes a main control device 60 and a storage device 70 as shown in FIG. Main controller 60 includes (a) position information (speed information) RPV of reticle R and position information (speed information) WPV of wafer W.
And a control device 69 for controlling the entire operation of the exposure apparatus 200 by supplying stage control data SCD to the stage control system 19 based on the imaging data IMD supplied from the wafer pre-alignment device 32. hand,
A wafer outline calculation device 61 that measures the outline of the wafer W and detects the center position and radius of the wafer W is provided. Here, the wafer outline calculation device 61 includes (i) an imaging data collection device 62 that collects imaging data IMD supplied from the wafer pre-alignment device 32, and (ii) imaging data collected by the imaging data collection device 62. An image processing device 63 for performing the image processing of (iii), and (iii) an image processing device 6
3 includes a parameter calculation device 66 for calculating the center position and radius of the wafer W, which are the shape parameters of the wafer W, based on the image processing result obtained by the step S3.

The image processing device 63 comprises: (i) a weight information calculating device 64 for obtaining the weight of each pixel data in the texture analysis window; and (ii) a texture analysis device based on the weight information and the image data of each pixel. A characteristic value calculating device 65 for calculating a texture characteristic value relating to the image in the window.

The storage device 70 has an image pickup data storage area 72 and a texture feature value storage area 73 therein.
, Boundary estimated position storage area 74, and measurement result storage area 7
5 is included.

In FIG. 8, the flow of data is indicated by solid arrows, and the flow of control is indicated by dotted arrows. The operation of each device of the main control system 20 configured as described above will be described later.

In the present embodiment, the main control device 60 is configured by combining various devices as described above. However, the main control system 20 is configured as a computer system, and the main control device 60
It is also possible to realize the function of each of the above-described devices constituting the above by a program built in the main control system 20.

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

In this exposure operation, first, in step 10
In 2, under the control of the main control system 20, a reticle R on which a pattern to be transferred is formed is loaded on a 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. 7).

Next, in step 103, the main control system 20 controls the vertical movement / rotation mechanism 38 via the pre-alignment control device 34, moves the carry-in arm 36 in the Z-axis direction, and Are the CCD cameras 40a, 4
0b, 40c is the height position of the observation surface. Further, the main control system 20 controls the linear motors 45a, 45b, 45c via the pre-alignment control device 34, and sets the background plates 42a, 42b, 42c at a position where a part of each of the background plates 42a, 42b, 42c faces the back surface of the wafer W. The plates 42a, 42b, 42c are moved.

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. An example of such an imaging result is shown in FIG.
(A) to (C). Here, FIG.
3 shows an image of the wafer W and an image of the background plate 42a in the imaging visual field VAA of the CCD camera 40a. FIG.
(B) shows an image of the wafer W and an image of the background plate 42b in the imaging visual field VAB of the CCD camera 40b. Also,
FIG. 10C shows the imaging visual field VA of the CCD camera 40c.
The image of the wafer W in C and the image of the background plate 42b are shown.

As shown in FIGS. 10A to 10C, the image of the wafer W is a substantially uniform bright area. On the other hand, the background plates 42a, 42b, 42 outside the wafer image
In the area of the image c (hereinafter referred to as “background plate image area”),
Polka dot patterns are periodically arranged as relatively dark images. Here, the brightness of the wafer image region and the bright region around the polka dot pattern in the background plate image region may have substantially the same brightness. In such a case, it is impossible to accurately estimate the outer edge of the wafer image area based on only the brightness distribution. The image data IMD of the wafer W thus imaged is supplied to the main control system 20. In the main control system 20, the imaging data collection device 62 receives the imaging data IMD, and stores the reception data in the imaging data storage area 72.

Returning to FIG. 9, next, in a subroutine 105, the shape of the wafer W is measured, that is, the center position Q _W and the radius R _W which are the shape parameters of the wafer W are measured. In this subroutine 105, texture analysis is performed to calculate a texture feature value for an image in the texture analysis window while moving the texture analysis window of a predetermined size, and analyze the distribution of the texture feature value.
Here, as the texture feature value, an average value or a variance of the pixel data in the texture analysis window may be adopted, but in the following description, the texture feature value corresponds to the average value of the pixel data in the texture analysis window. It is assumed to be dispersion.

That is, in the subroutine 105, FIG.
As shown in FIG. 1, first, in step 131,
The feature value calculation device 64 of the image processing device 63 sequentially moves the texture analysis window from the initial position, and as a texture feature value when the texture analysis window is at each position (X, Y), a pixel in the texture analysis window Data variance V (X,
Y) is calculated. In calculating the variance V (X, Y), first, the average value μ (X, Y) of the pixel data in the texture analysis window is calculated, and the average value μ (X, Y) in the texture analysis window is calculated. The variance V (X, Y) is calculated.

Subsequently, the characteristic value calculation device 64 stores the variance V (X, Y) at each position from the initial position to the end position of the texture analysis window calculated as described above in the texture characteristic value storage area 73. . Thus, the process of step 131 ends.

Next, at step 132, the boundary estimating device 65 reads the variance V (X, Y) which is the texture feature value from the texture feature value storage area 73. Here, for example, when a change in the variance V (X, Y) when the texture analysis window is moved along an axis parallel to the X axis,
It looks like this: That is, when the texture analysis window is in the background plate image area, the variance V (X, Y) has a uniform and relatively small value. When the texture analysis window is at the boundary between the background plate image area and the wafer image area, the variance V
(X, Y) is a large value. When the texture analysis window is located in the wafer image area, the variance V (X, Y) has a small value because the wafer image area is almost uniformly bright as described above.

FIG. 12A shows a graph of the change in the variance V (X, Y). This FIG.
As shown in (A), when the texture analysis window is at the boundary between the background image area and the wafer image area, the variance V
(X, Y) is larger than when the texture analysis window is in the background plate image region or the wafer image region, and is maximum when the texture analysis window is near the boundary between the background plate image region and the wafer image region. Becomes The nature of this change is similar at any boundary, and the distribution of the variance V (X, Y) is
FIG. 12B shows a dimensional change.

Using the property of the variance V (X, Y) at the boundary between the wafer image area and the background plate image area, the boundary estimating device 55 determines the point at which the variance V (X, Y) is maximal. Is estimated as the boundary between the wafer image region and the background plate image region.

As described above, by estimating the boundary between the background plate image region and the wafer image region, the imaging visual field VAC
As shown by the solid line in FIG. 12C representatively shown in FIG. 12, the actual wafer outer edge shown by the two-dot chain line can be estimated. The boundary estimation device 65 stores the estimated boundary position in the estimated boundary position storage area 74.

Returning to FIG. 11, step 133 is continued.
In the parameter calculation device 66, the wafer image area W
The center position Q _W and the radius R _{W of the} AR are calculated using a statistical method such as the least square method based on the estimated boundary position. The parameter calculation device 66 stores the center position Q _W and the radius R _W thus obtained in the measurement result storage area 75. Thus, the process of the subroutine 105 is completed, and the process returns to the main routine of FIG.

Next, in step 106, the control device 69 performs measurement for exposure preparation other than the shape measurement of the wafer W obtained above. That is, the control device 69 detects the position of the notch N on the wafer W based on the image data near the outer edge of the wafer W stored in the image data storage area 72. Thus, the rotation angle of the loaded wafer W about the Z axis is detected. Then, based on the detected rotation angle of the wafer W about the Z axis, the control device 69 may, if necessary,
The vertical movement / rotation mechanism 38 is controlled via the pre-alignment control device 34 to rotate the carry-in arm 36. Subsequently, the control device 69 operates the pre-alignment control device 34.
The vertical movement / rotation mechanism 38 is controlled via the
6 is driven to load the wafer W into the wafer holder 18.

Thereafter, when the exposure for the wafer W is the exposure for the second and subsequent layers, the control device 69 sets the above-described wafer for the purpose of forming a circuit pattern with a high degree of registration accuracy with the already formed circuit pattern. The movement of the wafer W, that is, the wafer stage W
The positional relationship between the reference coordinate system defining the movement of the ST and the arrangement coordinate system of the arrangement of the circuit patterns on the wafer W, that is, the arrangement of the chip area (shot area) is detected with high accuracy using the wafer alignment sensor. You.

Next, in step 107, exposure is performed. In this exposure operation, first, the wafer holder 18 is moved such that the XY position of the wafer W becomes the scanning start position for exposing the first shot area (first shot) on the wafer W. This movement includes the above-described shape measurement result of the wafer W read from the measurement result storage area 75, position information (speed information) WPV from the wafer interferometer 24, and the like (in the case of exposure of the second and subsequent layers, Based on the detection result of the positional relationship between the reference coordinate system and the array coordinate system, the position information (speed information) WPV from the wafer interferometer 24, etc., the main control system 20 transmits the information via the stage control system 19, the wafer driving device 15, and the like. Done. At the same time, reticle R
The reticle stage RST is moved such that the XY position of the reticle becomes the scanning start position. This movement is performed by the main control system 20
Is performed via the stage control system 19 and a reticle driving unit (not shown).

Next, the stage control system 19 controls the main control system 2
0, the multi-point focus position detection system (A
F ₁ , AF ₂ ), Z position information of the wafer detected by
X of reticle R measured by reticle interferometer 16
Based on the Y position information RPV and the XY position information WPV of the wafer W measured by the wafer interferometer 24, the reticle R and the wafer are adjusted while adjusting the surface position of the wafer W via the reticle driving unit and the wafer driving device 15. W is relatively moved to perform scanning exposure.

When the exposure of the first shot area is completed, wafer stage WST is moved so as to be at the scanning start position for exposure of the next shot area, 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. Thus, the exposure processing of the wafer W is completed.

As described above, according to the present embodiment, the epi-illumination method is employed, and the background plates 42a, 42 on which the patterns which do not exist on the surface of the wafer W are formed.
The wafer W is imaged with b and 42c as backgrounds. Then, the boundary between the wafer image region and the background plate image region is accurately estimated from the difference in image characteristics between the wafer image region and the background plate image region in the imaging result. Therefore, it is possible to accurately detect the position information of the wafer W while avoiding the complicated structure of the wafer stage WST and the incorporation of a heat source such as a light source into the wafer stage WST due to the adoption of the conventional transmissive illumination method. Can be. Further, it is possible to open a way to realize the observation of the surface of the wafer W, which is impossible in the case of the transmission illumination method.

In addition, since the position information of the wafer W is detected by the texture analysis technique by focusing on the difference in the pattern between the wafer image area and the background plate image area, the boundary may be determined only by the brightness distribution of the raw data of the imaging result. Is estimated as a continuous line, the position information of the wafer W can be accurately detected.

In the above embodiment, the pattern formed on the background plate is fixed, but the pattern may be variable using a liquid crystal substrate as the background plate. Further, a method of projecting a pattern on a plain background plate may be adopted. As a pattern of the background plate, a pattern other than the patterns shown in FIGS. 4A to 4E described above is used as long as it has an image processing characteristic which is known in advance and does not exist on the wafer W. Can also be used. For example, an arabesque pattern or a regular polygon pattern can be used.

Further, if an appropriate contrast can be secured between the wafer image (especially, the image of the outer edge of the wafer) and the background plate image, a background plate having no pattern (plain color) can be used as the background plate. Good.

In the above embodiment, as shown by the dotted line in FIG. 5, the diffusion plate 53 is arranged between the collimator lens 52 and the wafer W and the background plate 52a, and diffuses as incident illumination light. It is also possible to use light. In such a case, the reflected light from the outer edge of the wafer W, whose shape cannot be predicted in advance, can be reliably captured, so that the outer edge position of the wafer can be detected with high accuracy.

In the above embodiment, the vertical epi-illumination method is used for the imaging by the CCD cameras 40a, 40b, 40c, but it is also possible to use the oblique-light epi-illumination method. In the case of adopting the oblique light incident illumination method, the CCD cameras 40a, 40b, and 40c are provided with an observation illumination system including a light source 51 and a diffusion plate 53, as typically shown in FIG. With this configuration, the observation illumination system performs diffuse illumination that is more oblique and uniform. Then, an image by the reflected light from the surface of the wafer W and the background plate 42 a via the mirror 55 and the imaging optical system 56 is captured by the CCD image sensor 57. Also in this case, since the reflected light from the outer edge of the wafer W whose shape cannot be predicted in advance can be reliably captured, the outer edge position of the wafer can be detected with high accuracy.

In the above embodiment and the like, it is desirable to perform illumination according to the state of the outer edge of the wafer W. For this reason, it is preferable that the conditions such as the illumination direction, the type and position of the diffusing plate (or reflecting mirror), the type and position of the background plate (the distance between the background plate and the wafer), and the inclination be variable.

When the above-mentioned diffuse illumination light is employed, the background plate may be plain, and the reflection amount is sufficiently smaller than the amount of reflected light at the outer edge of the wafer reaching the image pickup device, for example, as a black semimic. Any material having a low reflectance that generates only light can be used.

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 visual field VA of the CCD camera at the outer edge in the direction of 4:30.
D, VAE, and VAC may be set.

Further, in order to correspond to the notch positions in both the 6 o'clock direction and the 3 o'clock direction,
It is also possible to set the imaging visual fields VAD, VAB, VAC, VAD, and VAE at five outer edges in the half-hour direction, the three-hour direction, and the half-hour direction.

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 case of the hour direction, as shown in FIG. 15 (A), the imaging visual fields VAD ', VAB', and VAC 'may be set at the outer edges of the 6 o'clock direction, the 10:30 direction, and the 1:30 direction. . When the notch position is in the 3 o'clock direction, as shown in FIG. 15B, the imaging visual fields VAD ', VAB', and VAE are provided at the outer edges of the 3 o'clock direction, the 10:30 direction, and the 7:30 direction. 'Should be set. Furthermore, in order to correspond to the notch positions of either the 6 o'clock direction or the 3 o'clock direction, images are taken at the outer edges of the 6 o'clock direction, the 10:30 direction, the 1:30 direction, the 3 o'clock direction, and the 7:30 direction. Field of view VAA ', VAB', VAC ', VA
D 'and VAE' may be set.

Further, in the above-described 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, FIG.
As shown in FIG. 16B, the imaging field of view is set at both ends of the orientation flat and another location (for example, when the orientation flat is at 6 o'clock, the outer edge at 3 o'clock). do it.

In the above embodiment, the wafer image and the background plate image are picked up, and the wafer image and the background plate image are distinguished by the image processing method to obtain the outer edge position information. It is also possible to separate the reflected light from the wafer and the reflected light from the background plate by a conventional method. As such an optical method, when the pattern on the background plate is periodic, for example, through a Fourier transform lens after image formation, from the black point corresponding to the pattern period of the background plate, which is arranged on the Fourier transform surface An optical filter blocks a reflected light component from the background plate. Thereafter, the image is re-formed by passing through an inverse Fourier transform lens to obtain an image based on the reflected light component from the wafer.

In the above embodiment, the background plate 42
Although a, 42b, and 42c are configured to be independently driven, the background plates 42a, 42b, and 42c may be attached to the loading arm. In this case, the outer edge of the wafer W and the background plate 42a,
Consideration of the focus difference between 42b and 42c and the background plate 4
There is no need to consider independent driving of 2a, 42b and 42c. In this case, the background plates 42a, 42b, 4
It is preferable that the pattern forming portion 2c does not directly contact the back surface of the wafer W. Also, the wafer holder 1
It is also possible to form a pattern that does not exist on the surface of the wafer W on the upper surface of the wafer 8.

In the above embodiment, the position detection method of the present invention is applied to the detection of the position information of the wafer W. However, the position detection method of the present invention can be applied to the detection of the position information of the reticle R. .

In the above embodiments, the case of a scanning type exposure apparatus has been described. However, the present invention relates to a reduction projection exposure apparatus using ultraviolet light as a light source, and a reduction 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.

In the above embodiments, the exposure apparatus has been described. However, the apparatus other than the exposure apparatus, for example, an apparatus for observing an object using a microscope or the like, the position of an object on a factory assembly line, a processing line, or an inspection line. It can also be used for information detection.

Further, in the above-described embodiment, the shape of the position detection target is substantially a circle. However, any other shape (for example, an ellipse, a square, etc.) can be applied.

<< Production of Device >> Next, production of a device using the exposure apparatus and the exposure method of the above embodiment will be described.

FIG. 17 shows devices (semiconductor chips such as IC and LSI, liquid crystal panels, CCs) in this embodiment.
D, thin-film magnetic head, micromachine, etc.). As shown in FIG.
First, in step 201 (design step), a function design of a device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in step 202 (mask manufacturing step), a mask on which the designed circuit pattern is formed is manufactured. On the other hand, in step 203 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step 204 (wafer processing step), actual circuits and the like are formed on the wafer by lithography using the mask and the wafer prepared in steps 201 to 203, as described later. Next, step 205 (device assembling step)
In step, chips are formed using the wafer processed in step 204. This step 205 includes processes such as an assembly process (dicing, bonding) and a packaging process (chip encapsulation).

Finally, step 206 (inspection step)
In step, inspections such as an operation confirmation test and a durability test of the device manufactured in step 205 are performed. After these steps, the device is completed and shipped.

FIG. 18 shows a detailed flow example of step 204 in the case of a semiconductor device. In FIG. 18, step 211 (oxidation step)
In, the surface of the wafer is oxidized. Step 212
In the (CVD step), an insulating film is formed on the wafer surface. In step 213 (electrode formation step), electrodes are formed on the wafer by vapor deposition. Step 2
At 14 (ion implantation step), ions are implanted into the wafer. Steps 211 to 214 described above
Each of them constitutes a pre-processing step of each stage of the wafer process, and is selected and executed according to a necessary process in each stage.

In each stage of the wafer process, when the pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, step 215
In (resist forming step), a photosensitive agent is applied to the wafer, and subsequently, in step 216 (exposure step), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus and the exposure method of the embodiment described above. Next, in Step 217 (development step), the exposed wafer is developed, and subsequently, Step 218 is performed.
In the (etching step), the exposed member other than the portion where the resist remains is removed by etching. Then, in step 219 (resist removing step), unnecessary resist after etching is removed.

By repeating these pre-processing and post-processing steps, multiple circuit patterns are formed on the wafer.

As described above, a device in which a fine pattern is accurately formed is manufactured.

[0121]

As described above in detail, according to the position detecting method of the present invention, the surface of an object and a background member on which a pattern not existing on the surface of the object is formed by the incident illumination method. Is performed, and the surface region and the background member region of the object in the observation result are distinguished, so that the position information of the object can be accurately obtained without employing the transmitted light illumination method.

Further, according to the position detecting device of the present invention, the position information of the object is detected by using the position detecting method of the present invention. Therefore, the position information of the object can be accurately obtained without employing the transmitted light illumination method. It can be detected well.

According to the exposure method of the present invention, the position information of the substrate is detected with high accuracy by using the position detecting method of the present invention, and the position of the substrate is controlled based on the detection result. Since the pattern is transferred to the substrate, the pattern can be transferred to the partitioned area with high accuracy.

Further, according to the exposure apparatus of the present invention, since the position information of the substrate is measured with high accuracy by the position detecting device of the present invention, the position control of the substrate can be performed with high accuracy.
As a result, the pattern can be accurately transferred to the substrate.

According to the device manufacturing method of the present invention, in the lithography step, a predetermined pattern is transferred onto a substrate by using the exposure method of the present invention. Can be manufactured.

[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;

FIGS. 3A and 3B are diagrams for explaining a configuration of a pre-alignment system of FIG. 1;

4 (A) to 4 (E) are diagrams for explaining patterns formed on the background plate of FIG. 3;

FIG. 5 is a diagram for explaining a configuration of the CCD camera of FIG. 3;

FIG. 6 is a perspective view showing the vicinity of a wafer supported by a loading arm during pre-alignment.

FIG. 7 is a diagram for explaining the arrangement of components relating to loading and unloading of a wafer.

FIG. 8 is a block diagram illustrating a configuration of a main control device.

FIG. 9 is a flowchart for explaining an exposure operation by the exposure apparatus of FIG. 1;

FIGS. 10A to 10C are diagrams for explaining an imaging result by a pre-alignment detection system.

FIG. 11 is a flowchart illustrating a process of a wafer outline measurement subroutine of FIG. 9;

FIGS. 12A to 12C are diagrams for explaining distribution of variance in wafer outer shape measurement and estimation results of the outer edge of the wafer.

FIG. 13 is a diagram illustrating a configuration of a modified example of the CCD camera.

FIG. 14 is a diagram showing another example of the imaging visual field position of a 12-inch wafer.

FIGS. 15A and 15B are diagrams illustrating an example of an imaging visual field position of a notched 8-inch wafer.

FIG. 16A and FIG. 16B are diagrams showing examples of the position of the imaging visual field of an 8-inch wafer with an orientation flat.

FIG. 17 is a flowchart illustrating a device manufacturing method.

FIG. 18 is a flowchart of a process in a wafer processing step of FIG. 17;

[Explanation of symbols]

36 ... Carry-in arm (support member), 42a, 42b, 42
c: background plate (background member), 45a, 45b, 45c: linear motor (background member driving device), 51: light source (part of irradiation system), 52: collimator lens (part of irradiation system),
53: diffusion plate (diffusion member), 54: half mirror (part of irradiation system), 56: imaging optical system (part of processing device), 5
7 ... CCD imaging device (part of imaging device and processing device), 6
3: Image processing device, W: Wafer (substrate, object), WST
… Wafer stage (stage equipment)

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) H01L 21/30 502M 520A (72) Inventor Akira Takahashi 3-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikonai F term (reference) 2F065 AA12 AA17 AA26 AA37 AA39 AA51 BB02 BB03 BB27 CC19 FF42 HH03 HH13 JJ03 JJ05 JJ09 JJ26 LL00 LL04 LL10 LL12 LL21 LL49 LL59 NN20 PP12 PP13 QQ21 QQ23 QQ24 QQ29 QQ36 QQ41 QQ42 TT01 2H051 AA10 BB17 BB25 CB05 CC07 5F031 CA02 CA07 FA01 FA07 FA12 FA14 GA02 GA30 GA47 GA48 GA49 HA13 HA53 JA02 JA04 JA06 JA14 JA15 JA17 JA22 JA28 JA29 JA30 JA32 JA34 JA35 JA36 JA38 KA06 KA07 KA08 KA10 KA13 KA14 LA04 LA08 MA27 5F046 DB05 DB10 EB01 EB10 FA10 FA20 FC08

Claims (14)

[Claims] 1. A position detection method for detecting position information of an object, comprising: a first step of arranging a background member having a pattern not present on the surface of the object on a back side of the object;
A second step of irradiating illumination light from the surface side of the object; and a third step of obtaining position information of an outer edge of the object based on reflected light from the surface of the object and the background member. Method. 2. The position detecting method according to claim 1, wherein the surface of the object is substantially flat, and the illumination light is substantially perpendicularly incident on a plane portion of the surface of the object. 3. The surface of the object is substantially flat, and the illumination light is obliquely incident on a plane portion of the surface of the object.
The position detecting method according to claim 1, wherein: 4. The position detecting method according to claim 1, wherein the illumination light is diffused light. 5. The method according to claim 5, wherein the third step is a step of capturing an image of the surface of the object and the background member formed by the reflected light; 5. A position detecting method according to any one of claims 1 to 4, further comprising: a fifth step of obtaining position information of an outer edge of the image. 6. The position detecting method according to claim 5, wherein the image processing is a texture analysis processing. 7. A position detecting device for detecting position information of an object, comprising: a support member for supporting the object; a background member on which a pattern not existing on the surface of the object is formed; An irradiation system that irradiates illumination light from the front surface side of the object disposed on the back surface side; and a processing device that processes reflected light from the surface of the object and the background member to obtain positional information of an outer edge of the object. A position detection device comprising: 8. The apparatus according to claim 1, further comprising a background member driving device configured to move the background member on the back side of the object supported by the support member in a direction to approach and separate from the object. 8. The position detecting device according to 7. 9. The position detection device according to claim 7, wherein the background member is provided on the support member. 10. The illumination system according to claim 7, wherein the illumination system includes: a light source that generates the illumination light; and a light diffusion member that diffuses the illumination light.
The position detecting device according to claim 1. 11. An image processing apparatus comprising: an image forming optical system configured to form the reflected light; an image capturing apparatus configured to capture an image formed by the image forming optical system; An image processing device for obtaining position information of an outer edge of the object, the position detection device according to any one of claims 7 to 10. 12. An exposure method for irradiating a substrate with an exposure beam to form a predetermined pattern on the substrate, wherein the position information of the substrate is provided as the position according to any one of claims 1 to 6. A position detecting step of detecting by a detecting method; a pattern forming step of controlling the position of the substrate based on the position information of the substrate detected in the position detecting step, and forming the predetermined pattern on the substrate. An exposure method comprising: 13. An exposure apparatus that irradiates an exposure beam onto a substrate to form a predetermined pattern on the substrate, and detects positional information of the substrate. An exposure apparatus comprising: a position detecting device; and a stage device having a stage on which the substrate whose position is detected by the position detecting device is mounted. 14. A device manufacturing method including a lithography step, wherein exposure is performed using the exposure method according to claim 12 in the lithography step.