JPH088174A - Pattern position detection method - Google Patents

Abstract

(57) [Summary] (Correction) [Object] The present invention facilitates the position designation of a region near an arbitrary unit pattern on a substrate to be inspected in a pattern position detecting method. [Structure] An origin, which is a reference of a position to be detected, is set on a substrate 5, a two-dimensional coordinate system is set with the origin as a reference, and a first direction in the coordinate system is set based on a predetermined pitch. The first pitch Xp and the second direction in the second direction orthogonal to the first direction.
Pitch Yp is set and arbitrary unit pattern 2 from the origin
Up to 7B, the first quantity of the unit patterns 27B in the first direction and the second quantity of the unit patterns 27A in the second direction are counted, and the position of the area near an arbitrary unit pattern 27B is set to the first position.
Quantity and second quantity, first pitch Xp and second pitch Y
Specify based on p and.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern position detecting method, which is applied, for example, when a large-area large-sized liquid crystal display panel is formed by connecting small-area patterns on a large-sized photosensitive substrate and exposing them by a projection exposure apparatus. You can

[0002]

2. Description of the Related Art Conventionally, in an exposure apparatus for forming a large-sized liquid crystal display panel of this type, a desired pattern is finally obtained by exposing a plurality of layers of other patterns on the connected pattern. There is. When the patterns are overlapped and exposed as described above, the exposure position of the upper layer pattern is corrected according to the position of the lower layer pattern, so that the position of the lower layer pattern is measured.

When measuring the position of an arbitrary exposure region of the lower layer pattern, the user designates the position of the arbitrary exposure region by inputting coordinates having the center of the photosensitive substrate as an origin to a control device or the like. Was there. The user has calculated and calculated the coordinates of an arbitrary exposure area based on the design dimension value of the original image pattern formed on the reticle, and input the calculated coordinates.

[0004]

However, in the above-described conventional position designation method, a plurality of measurement points are actually set, and it is necessary to calculate the coordinates for each measurement point. Therefore, the designated position may differ from the desired position due to a calculation error. If the coordinates are incorrect, the user will have to recalculate and re-enter all the coordinates. Further, since it is necessary to calculate all of a plurality of measurement points, there is a problem that it takes a long time to measure and a manufacturing throughput is reduced.

Further, the shape and size of the photosensitive substrate and the pattern,
The arrangement, the number of joint exposures, and the like are various. For this reason, it is necessary to calculate and input the coordinates according to each case, and there is a drawback that it is complicated.

The present invention has been made in consideration of the above points, and is intended to propose a pattern position detection method that can easily specify the position of an area near an arbitrary unit pattern on a substrate to be inspected. is there.

[0007]

In order to solve such a problem, the present invention will be described in association with FIG. 1 to FIG. 3 showing an embodiment. In the exposure apparatus according to claim 1,
A substrate (5) having a plurality of predetermined unit patterns (27) arranged in a predetermined pitch is an object to be inspected. In the pattern position detecting method of relatively positioning by means of relative positioning to detect the position of an arbitrary unit pattern (27B) on the substrate (5), an origin serving as a reference of a position to be detected is set on the substrate (5). At the same time, a two-dimensional coordinate system based on the origin is set, and based on a predetermined pitch, a first pitch (Xp) in the first direction within the coordinate system and a first pitch (Xp) orthogonal to the first direction within the coordinate system. Two-way second pitch (Y
p) and set the arbitrary unit pattern (27
The first quantity of the unit pattern (27B) in the first direction up to B) and the second quantity of the unit pattern (27A) in the second direction are counted, and the position of the area near the arbitrary unit pattern (27B) is determined. Relative positioning is performed by designating based on the first quantity and the second quantity and the first pitch (Xp) and the second pitch (Yp).

In the exposure apparatus according to the second aspect, the object to be inspected is a first partial pattern region (24A) composed of a plurality of unit patterns (27) and a plurality of unit patterns (2).
The second partial pattern region (24B) configured in 7) is formed by connecting or overlapping each other, and as an arbitrary unit pattern (27B) to be detected,
Designate the pattern (27B) of the joined or overlapped portion (25A).

According to the third aspect of the exposure apparatus, the first partial pattern region (24A) and the second partial pattern are formed on the basis of the detection result of the arbitrary unit pattern (27B) when they are connected or overlapped. The correction amount of the position with respect to the pattern area (24B) is determined.

[0010]

In the exposure apparatus method according to the first aspect, the origin serving as the reference of the position to be detected is set on the substrate (5), and the two-dimensional coordinate system based on the origin is set to the predetermined position. Based on the pitch, a first pitch (Xp) in the first direction and a second pitch (Yp) in the second direction orthogonal to the first direction in the coordinate system are set, and an arbitrary unit pattern (2
7B) of the first unit pattern (27B) in the first direction
The quantity and the second quantity of the unit pattern (27A) in the second direction are counted, and the position of the area near the arbitrary unit pattern (27B) is determined by the first quantity and the second quantity and the first pitch (Xp).
And the second pitch (Yp), it is possible to easily specify the area in the vicinity of an arbitrary unit pattern (27B) on the substrate (5) to be inspected.

In the exposure apparatus according to the second aspect, the first partial pattern area (24A) composed of a plurality of unit patterns (27) and the second partial pattern area composed of a plurality of unit patterns (27). By designating the pattern of the portion in which (24B) is connected or overlapped with each other as the inspection target, it is possible to detect the shift amount of the pattern in this combined or overlapped portion (25A). .

In the exposure apparatus according to the third aspect, the first partial pattern region (24) at the time of forming the patterns by joining or overlapping based on the detection result of an arbitrary unit pattern.
By determining the correction amount of the positions of (A) and the second partial pattern area (24B), it is possible to improve the alignment accuracy of the aligned or superposed portion (25A).

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Configuration of the Embodiment (1-1) Overall Configuration of Projection Exposure Apparatus In FIG. 1, reference numeral 1 denotes a projection exposure apparatus for manufacturing a large-sized liquid crystal display panel which is aligned by image processing as a whole, and is an ultrahigh pressure mercury. The exposure light emitted from the light source 2 such as a lamp is condensed by the elliptical mirror 3 and then incident on the condenser lens system 4 via an optical integrator or the like.

The exposure light properly condensed by the condenser lens system 4 illuminates the reticle R with a substantially uniform illuminance.
By the exposure light, the pattern of the reticle R is projected onto each shot area on the photosensitive substrate 5 via the projection optical system PL. After that, a large-sized liquid crystal display panel is manufactured by sequentially exposing a plurality of layers of circuit patterns on the photosensitive substrate 5 and exposing them.

The photosensitive substrate 5 is held on the Z stage 6,
The Z stage 6 is placed on the XY stage 7. X
The Y stage 7 mounts the photosensitive substrate 5 on the optical axis (Z
The Z stage 6 positions the photosensitive substrate 5 in the Z-axis direction by positioning in a plane (XY plane) perpendicular to the axis. A θ table (not shown) for rotating the photosensitive substrate 5 is interposed between the Z stage 6 and the photosensitive substrate 5. A reference mark assembly 8 having various alignment marks formed thereon is fixed near the photosensitive substrate 5 on the Z stage 6.
A movable mirror 9 for distance measurement in the X and Y directions is fixed near the reference mark assembly 8.

The moving mirror 9 is irradiated with a laser beam from a laser interferometer 10. The laser interferometer 10 receives the reflected light reflected by the mirror surface of the movable mirror 9 to constantly measure the position of the XY stage 6, and sends a position signal S1 to the device control computer 11. The device control computer 11 sends a drive signal S2 based on the position signal S1 to the drive device 12 to drive the XY stage 7.

The alignment microscope 13 has a reticle R
At the time of alignment, the alignment mark RM in the vicinity of the pattern area of the reticle R is irradiated with the alignment light via the mirror 14. The reflected light from the alignment mark RM is reflected by the mirror 14 and returned to the microscope 13. For example, the reticle R is aligned by adjusting the position of the reticle R based on the position of the image of the alignment mark RM that is re-imaged inside the alignment microscope 13.

The autofocus detection system comprises a light transmitting system 15 and a light receiving system 16. The light transmitting system 15 directs an image of a detection pattern such as a slit pattern toward the photosensitive substrate 5 along the optical axis AX of the projection optical system PL. Project it diagonally. The image of the detection pattern is re-imaged in the light receiving system 16 by the reflected light of the image of the detection pattern. The height of the exposed surface of the photosensitive substrate 5 is determined from the amount of positional deviation of the image of the re-formed detection pattern, and the height of the exposed surface of the photosensitive substrate 5 is determined by the Z stage 6 with respect to the projection optical system PL. It is set to the waste position.

An alignment optical system for image processing is arranged on the side of the projection optical system PL. The alignment optical system relays the reflected light reflected from the observation area on the photosensitive substrate 5 via the objective lens 17 and the mirror 18 to the relay lens 1
Lead to 9. Then, this reflected light is converted into a charge imaging type image pickup device (C
A CCD is used to focus on the image pickup surface of the CCD camera 20, and an image of the pattern of the observation region is formed on the image pickup surface.

The pattern matching device 21 takes in a video signal (imaging signal) S3 output from the CCD camera 20 as an image to be processed. The pattern matching device 21 stores the template image in the memory and obtains the coordinates of the pattern that matches the template by pattern matching. The pattern matching device 21 sends a coordinate signal S4 representing this coordinate value to the device controlling computer 11.

The device controlling computer 11 obtains the amount of deviation generated during joint exposure or overexposure based on the coordinate signal S4, and when the next or subsequent pattern areas are joined or overlaid for exposure. Is given to the drive unit 12 as a correction parameter to improve the alignment accuracy. Further, the apparatus control computer 11 can correct the image forming characteristics of the projection optical system PL and feed back the reticle alignment system with the correction parameters obtained here.

The image stored as the template image is a part of the image pattern formed on the photosensitive substrate 5. An input device (here, keyboard) 22 and an output device (here, cathode ray tube) 23 are connected to the device control computer 11.

(1-2) Structure of Pattern on Photosensitive Substrate As shown in FIG. 2, four reticle pattern images 24A, 24B, 24C and 24D are formed on the photosensitive substrate 5 by, for example, joint exposure as the first layer. Has been done. The reticle pattern images 24A and 24B are connected by a boundary line 25A. Similarly, reticle pattern images 24B and 24C, 2
4C and 24D, 24D and 24A are connected by boundary lines 25B, 25C and 25D, respectively.

The reticle pattern image 24A is shown in FIG.
As shown in FIG. 3, a series of pixel patterns 2 extending in the X direction of the photosensitive substrate 5 (on the left and right in the plane of the paper of FIGS. 2 and 3).
7 are arranged regularly and repeatedly in the Y direction (upward and downward direction toward the paper surface) with constant pitch Yp. The pixel pattern 27 includes a trunk portion 27A extending in the X direction and a plurality of branch portions 27B slightly protruding from the trunk portion 27A in the Y direction (vertical direction toward the paper surface).

The branch portion 27B has a constant pitch Xp in the X direction.
Are regularly repeated in the array. The reticle pattern images 24B to 24D are formed in the same manner as the reticle pattern image 24A. Note that the pitches Xp and Yp in the X and Y directions are the pitches Xp and Yp when enlarged on the photosensitive substrate 5.
It is determined based on the pitch values in the X and Y directions of the original image pattern designed to be p and formed on the reticle R, and the enlargement ratio of the original image pattern.

(2) Operation of the embodiment In the above configuration, for example, when a region near the arbitrary branch portion 27B on the boundary line 25A is designated as a measurement point and the arbitrary branch portion 27B is measured by pattern matching. , The measurement procedure step SP0 shown in FIG. 4 is executed.

That is, in step SP1, the user determines, for example, the upper left corner of the reticle pattern image 24A as the reference origin of the position of the area near the arbitrary branch 27B, and this position is input from the input device 22 to the device controlling computer. Set to 11. As a result, the apparatus control computer 11 sets an XY orthogonal coordinate system in which the upper left corner of the reticle pattern image 24A is the origin (that is, (X, Y) = (0,0)) in the plane of the photosensitive substrate 5.

Subsequently, the user sets the pitches Xp and Yp in the X and Y directions in the device control computer 11 at step SP2 and moves to step SP3. In step SP3, the user selects an arbitrary branch 27 from the origin.
The arrangement up to B, that is, the number of branch portions 27B in the X direction (hereinafter referred to as the number of columns) and the number of trunk portions 27A in the Y direction (hereinafter referred to as the number of rows) are counted, and the device control computer 11
Set to. By counting only the number of columns and rows,
Compared with the case where the user himself calculates and sets the coordinates, the time until the user sets the coordinates in the device control computer 11 can be further reduced.

The device controlling computer 11 is a step S
In P4, the calculation is performed based on the number of columns and the pitch Xp in the X direction, and the calculation is performed based on the number of rows and the pitch Yp in the Y direction to be converted into coordinates (X, Y) of the arbitrary branch portion 27B. . Subsequently, the device control computer 11 sends a drive signal S2 corresponding to the coordinates (X, Y) to the drive device 12 to drive the XY stage 7. As a result, a region near the arbitrary branch portion 27B is positioned relatively to the optical axis of the alignment optical system.

In step SP5, the pattern matching device 21 measures the coordinates of the arbitrary branch portion 27B by pattern matching, and moves to step SP6 to end the measurement. In this way, the boundary line 2 generated during exposure
The amount of pattern deviation in the area near the arbitrary branch portion 27B on 5A is obtained. This makes it possible to improve the alignment accuracy in the vicinity of the boundary line 25A by using the correction parameter according to the amount of deviation when exposing the pattern on and after the next time.

(3) Effects of the Embodiments According to the above configuration, the origin that serves as the reference for the position of the area near the arbitrary branch 27B is set at the upper left corner of the reticle pattern image 24A, and this origin is used as the reference. XY Cartesian coordinate system is set, and based on the pitches in the X and Y directions of the original image pattern, the pitch X in the X and Y directions in the XY Cartesian coordinate system is set.
p and Yp are set, the number of columns and rows from the origin to the arbitrary branch 27B is counted, and the position of the area near the arbitrary branch 27B is determined based on the number of columns and rows and the pitches Xp and Yp. The arbitrary branch portion 2 on the photosensitive substrate 5 can be specified by
It is possible to easily specify the area near 7B.

Further, since the measurement points need only be specified by counting the number of columns and rows and no calculation by the user is required, the time until measurement can be further shortened, and manufacturing throughput can be improved. Furthermore, since the measurement points need only be specified by counting the number of columns and rows, the setting of the measurement points can be changed easily and erroneous input can be reduced. In addition, even if the measurement point is specified incorrectly, most of the time it is only necessary to change the origin and pitch.

(4) Other Embodiments In the above embodiment, the case where four reticle pattern images 24A, 24B, 24C and 24D are connected and exposed to detect the position of an arbitrary branch portion 27B will be described. However, the present invention is not limited to this, and can also be applied to the case where one reticle pattern image having a large area is exposed to detect the position of an arbitrary branch portion. Also in this case, the same effect as described above can be obtained.

Further, in the above-mentioned embodiment, the case has been described in which the origin serving as the reference of the position of the area near the arbitrary branch portion 27B is set at the upper left corner of the reticle pattern image 24A, but the present invention is not limited to this. For example, it may be set at an arbitrary position such as the upper right corner of the reticle pattern image 24B, the boundary lines 25A to 25D, the center of the substrate 5, and the like.

Further, in the above-mentioned embodiment, the case of exposing the photosensitive substrate 5 for manufacturing the liquid crystal display device is described, but the present invention is not limited to this, and for example, a photosensitive substrate for manufacturing a plasma display or Semiconductor substrates, etc.
It can be widely applied to the case of exposing an arbitrary exposure object.

[0037]

As described above, in the pattern position detecting method according to the first aspect, the origin serving as the reference of the position to be detected is set on the substrate and the two-dimensional coordinate system based on the origin is used. The first pitch in the first direction and the second pitch in the second direction orthogonal to the first direction in the coordinate system are set based on the predetermined pitch, and the first pitch from the origin to the arbitrary unit pattern is set. The first quantity of the unit pattern in the one direction and the second quantity of the unit pattern in the second direction are counted, and the position of the area near the arbitrary unit pattern is set to the first quantity and the second quantity.
By specifying based on the pitch and the second pitch, it is possible to realize a pattern position detecting method that can easily specify the area in the vicinity of an arbitrary unit pattern on the substrate to be inspected.

In the pattern position detecting method according to the second aspect, a first partial pattern area formed of a plurality of unit patterns and a second partial pattern area formed of a plurality of unit patterns are connected to each other, or By designating the pattern of the overlapped portion as the inspection target, it is possible to detect the deviation amount of the pattern of the matched or overlapped portion.

In the pattern position detecting method according to the third aspect of the present invention, the first partial pattern area and the second partial pattern area are formed on the basis of the detection result of an arbitrary unit pattern when they are connected or overlapped. By determining the correction amount of the position, it is possible to improve the alignment accuracy of the aligned or superposed portions.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram for explaining a projection exposure apparatus.

FIG. 2 is a schematic diagram showing a photosensitive substrate that has been jointly exposed.

FIG. 3 is a plan view showing a pixel pattern.

FIG. 4 is a flowchart showing a pattern position measuring procedure according to an embodiment of a pattern position detecting method according to the present invention.

[Explanation of symbols]

1 ... Projection exposure device, 2 ... Light source, 3 ... Elliptical mirror, 4 ...
... condenser lens system, 5 ... photosensitive substrate, 6 ... Z stage, 7 ... XY stage, 8 ... reference mark assembly,
9 ... moving mirror, 10 ... laser interferometer, 11 ... device control computer, 12 ... driving device, 13 ... alignment microscope, 14 ... mirror, 15 ... light transmission system, 1
6 ... Light receiving system, 17 ... Objective lens, 18 ... Mirror,
19 ... Relay lens, 20 ... CCD camera, 21 ...
... Pattern matching device, 22 ... Input device, 23 ...
... Output device, 24A to 24D ... Reticle pattern image,
25A to 25D ... Boundary line, 26A to 26D ... Vernier pattern, 27 ... Pixel pattern, 27A ... Executive,
27B ... Branch, R ... Reticle, PL ... Projection optical system.

Claims (3)

[Claims] 1. A substrate in which a plurality of predetermined unit patterns are arrayed at predetermined pitches is an object to be inspected, and an arbitrary region in the vicinity of the unit pattern on the substrate is relatively positioned with respect to a position detecting means. In a pattern position detecting method for detecting a position of an arbitrary unit pattern on the substrate, an origin serving as a reference of the position to be detected is set on the substrate, and a two-dimensional coordinate system based on the origin is set. Is set, based on the predetermined pitch, the first pitch in the first direction in the coordinate system, and the second pitch in the second direction orthogonal to the first direction in the coordinate system, A first quantity of the unit pattern in the first direction from the origin to the arbitrary unit pattern and a second quantity of the unit pattern in the second direction are counted, and a region near the arbitrary unit pattern is counted. position The pattern position detecting method is characterized in that the relative positioning is performed by designating based on the first quantity and the second quantity and the first pitch and the second pitch. 2. The object to be inspected is formed by connecting or overlapping a first partial pattern area composed of a plurality of the unit patterns and a second partial pattern area composed of a plurality of the unit patterns. The pattern position detecting method according to claim 1, wherein the pattern of the connected or superposed portions is designated as the arbitrary unit pattern to be detected. 3. A correction amount of a position between the first partial pattern region and the second partial pattern region when forming the joint or the overlapping is determined based on a detection result of the arbitrary unit pattern. The pattern position detecting method according to claim 1 or 2, wherein