JPH1123224A - Pattern coordinate measuring method and apparatus - Google Patents

Abstract

(57) Abstract: A method and an apparatus for measuring a pattern coordinate of a substrate, in which the influence of the deflection of the substrate is removed to accurately measure the pattern coordinate. An XY stage (11) for mounting a reticle (1) substantially vertically to a horizontal line via a holder (30),
A detection system 23 arranged on the side of the XY stage 11. The detection system 23 includes an objective lens 21 and a detection optical system 22 having a built-in light receiving element for detecting light directly reflected from the pattern.
And detectors 20a to 20d installed between the objective lens 21 and the stage in the X-axis and Y-axis directions. The reticle 1 is placed on the XY stage 11 with the pattern surface 1a facing sideways. The laser beam is focused on the pattern surface 1a from the side of the XY stage 11, and the pattern of the reticle 1 is detected by detecting the scattered light from the pattern edge by the detectors 20a to 20d. The position of the XY stage 11 when the pattern is detected is read by the X-axis interferometer 12a and the Y-axis interferometer 12b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the coordinate position of a pattern formed on the surface of a substrate such as a reticle.

[0002]

FIG. 8 is a view showing a conventional pattern coordinate measuring apparatus. As shown in FIG. 8, a conventional pattern coordinate measuring apparatus includes an XY stage 11 on which a reticle 1 is mounted.
A detection system 23 for detecting the pattern of the reticle 1;
X-axis interferometer 1 for detecting the position of Y stage 11
2a and a Y-axis interferometer 12b. Detection system 23
Is located above the XY stage 11 and the objective lens 2
1, a detection optical system 22 having a light receiving element for detecting light directly reflected from the pattern of the reticle 1, and an objective lens 21
And detectors 20a to 20d disposed in the space between the reticle 1 and the X and Y axes and receiving scattered light from the pattern of the reticle 1. The XY stage 11 is fixed on a surface plate (not shown), and has a detection system 23 and a detector 20a.
To 20d are fixed to a frame (not shown) fixed on the surface plate. In such a pattern coordinate measuring apparatus, the reticle 1 is
a is placed with its a facing upward. Then, the laser beam is focused on the pattern surface 1a and scanned, and the scattered light from the pattern edge is detected by the detectors 20a to 20d.
Alternatively, the reticle pattern is detected by receiving the directly reflected light by the light receiving element of the detection optical system 22. Alternatively, a method of providing a CCD camera in the detection optical system 22, forming a pattern image on the imaging surface of the CCD camera, obtaining an image signal representing the pattern image, and performing image processing on the image signal to perform detection. Are also mentioned.

[0003] Then, when this pattern is detected, X
The position of the Y stage 11 is read by the X-axis interferometer 12a and the Y-axis interferometer 12b. In this way,
The pattern information detected by the detection system 23 and the interferometer 1
A plurality of pattern coordinates on the reticle 1 are measured from the information on the position of the XY stage 11 read by 2a and 12b.

[0004]

However, in the above-described pattern coordinate measuring apparatus, when the reticle is placed on the XY stage, the reticle bends by its own weight, and the pattern surface expands and contracts due to the influence of the bend. An error will occur when measuring the pattern coordinates.

Therefore, in order to obtain pattern coordinates from which the influence of deflection has been removed, it is necessary to calculate the amount of deflection due to the weight of the reticle by structural analysis or the like, and to correct the measured pattern coordinates using the calculation results. is there. However, the amount of deflection of the reticle depends on the size of the reticle,
Since it differs depending on the thickness, the material, and the like, it is necessary to prepare various correction values corresponding to the reticle to be measured, and there is a problem that the system of the apparatus becomes complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and a method for measuring the pattern coordinates of a substrate such as a reticle, which can remove the influence of the deflection of the reticle and minimize the measurement errors of the pattern coordinates. It is to provide a device.

[0007]

FIG. 1 shows an embodiment of the present invention.
According to the first aspect of the present invention, the substrate 1 having a pattern formed on its surface is placed on the mounting table 11, and the pattern of the placed substrate 1 is detected by the pattern detection unit 23. The method is applied to a method of measuring the coordinates of a pattern. The substrate 1 is mounted on the mounting table 11 so that the pattern surface 1a of the substrate 1 is substantially perpendicular to the horizontal line, and the pattern is detected by the pattern detection unit 23. Achieve the above objectives.

According to a second aspect of the present invention, the mounting table is an XY stage 11, and a pattern is detected by a pattern detection unit 23 arranged on the side of the XY stage 11, and the position of the XY stage 11 is detected when the pattern is detected. By doing so, the coordinates of the pattern are measured.

Referring to FIG. 4, according to a third aspect of the present invention, a pattern detecting section 23 is mounted on an XY stage 11 disposed on a side of a mounting table, and a pattern is detected by the pattern detecting section 23. Then, the coordinates of the pattern are measured by detecting the position of the XY stage 11 when the pattern is detected.

Referring to FIG. 7, according to a fourth aspect of the present invention, a substrate 1 having a pattern formed on its surface is placed on an X stage 11a such that a pattern surface 1a is substantially perpendicular to a horizontal line. , A pattern detection unit 23 installed on a Y stage 11b arranged on the side of the X stage 11a
And the X stage 11a and the Y stage 11 when the pattern detection unit 23 detects the pattern.
The above object is achieved by measuring the coordinates of the pattern by detecting the position b.

Referring to FIG. 1, an XY stage 11 for mounting a substrate 1 having a pattern formed on its surface such that its pattern surface 1a is substantially perpendicular to a horizontal line. A pattern detection unit 23 installed on the side of the XY stage 11 for detecting a pattern; and position detection units 12a and 12b for detecting the position of the XY stage 11.
When the pattern detection unit 23 detects a pattern, the position detection units 12a and 12b
The above object is achieved by measuring the coordinates of the pattern by detecting the position of.

Referring to FIG. 4, the invention according to claim 6 comprises a mounting table for mounting a substrate 1 having a pattern formed on its surface such that its pattern surface 1a is substantially perpendicular to a horizontal line. XY stage 11 provided on the side of the mounting table
And a pattern detection unit 23 installed on the XY stage 11 for detecting a pattern, and position detection units 12a and 12b for detecting the position of the XY stage 11, and a position detection unit when the pattern detection unit 23 detects the pattern. 12a,
The above object is achieved by measuring the coordinates of the pattern by detecting the position of the XY stage 11 using 12b.

Referring to FIG. 7, the invention according to claim 7 is an X stage 11a for mounting a substrate 1 having a pattern formed on its surface such that its pattern surface 1a is substantially perpendicular to a horizontal line. A Y stage 11b provided on the side of the X stage 11a, a pattern detector 23 mounted on the Y stage 11b to detect a pattern, and a position detector for detecting the positions of the X stage 11a and the Y stage 11b, respectively. Units 12a and 12b, and when the pattern detection unit 23 detects a pattern, the position detection units 12a and 12b
X stage 11a and Y stage 11b
The above object is achieved by measuring the coordinates of the pattern by detecting the position of.

According to an eighth aspect of the present invention, in the measuring apparatus according to any one of the fifth to seventh aspects, a horizontal side of the substrate 1 in the direction of gravity and a vertical side adjacent to the horizontal side are respectively pressed. The positioning members 3A, 3B and the positioning members 3A,
3B is provided with biasing members 4A and 4B for pressing the substrate 1 via the pressing members 3C and 3D, and the positioning members 3A and 3B and the pressing members 3C and 3D are brought into contact with the edge on the front side of the substrate 1 and An inclined surface SP for pressing the substrate 1 toward the stage is formed.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to the embodiment.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a pattern coordinate measuring device according to a first embodiment of the pattern coordinate measuring method according to the present invention. In FIG. 1, FIG.
(A) and (b) do not show the holder shown in detail. As shown in FIG. 1, the pattern coordinate measuring apparatus according to the first embodiment of the present invention uses a holder 30 (FIGS. 2A and 2B) so that a reticle 1 is perpendicular to a horizontal line. An XY stage 11 for mounting, a detection system 23 arranged beside the XY stage 11 for detecting the pattern of the reticle 1, and an X-axis interferometer 12a for detecting the position of the XY stage 11 And Y-axis interferometer 1
2b. The detection system 23 includes an objective lens 21, a detection optical system 22 including a light receiving element that receives light directly reflected from the pattern of the reticle 1, and an X and Y axis in a space between the objective lens 21 and the XY stage 11. And detectors 20a to 20d provided in the respective directions and detecting scattered light from the pattern of the reticle 1. Interferometer 12
a and 12b irradiate a laser beam toward the mirrors 14X and 14Y on the stage 11, receive the reflected light, and detect the position. Detection system 23 and detector 20a
XY stage 1 is fixed on a surface plate (not shown).
The non-movable portion 1 is fixed to a frame (not shown) fixed on the surface plate.

In such a pattern coordinate measuring apparatus, the reticle 1 is arranged such that the pattern surface 1a on the XY stage 11 faces the detection system 23 and is perpendicular to a horizontal line, as shown in FIGS. 2 (a) and 2 (b). It is placed via a holder 30 as shown. The holder 30 is installed on the XY stage 11 by a fastening device (not shown). The holder 30 is provided with a reticle holding device. The holding device includes positioning members 3A and 3B for positioning the bottom side and one side of the reticle 1, and a positioning member 3 for positioning the upper side of the reticle 1.
A spring 4 for pressing toward A through the pressing member 3C
A and a spring 4B for pressing the other side toward the positioning member 3B via the pressing member 3D. The holder 30 holds the reticle 1 by pressing the reticle 1 against the positioning members 3A and 3B by the springs 4A and 4B so that the reticle 1 does not shift during measurement. The pressing members 3C and 3D are respectively guided by guide holes provided in the holder 30 so as to vertically move the reticle 1.

Positioning members 3A and 3B and pressing member 3
Each of C and 3D has an inclined surface SP as shown in FIG. 2B, and presses the edge of the surface of the reticle 1 with the inclined surface SP to press the reticle 1 against the XY stage 11.
As shown in FIGS. 3A and 3B, a vacuum suction pad is provided on a holder 30 fixed on the XY stage 11 so that the reticle 1 does not fall down in the vertical direction during measurement. 1 may be vacuum-adsorbed to the holder 40.
In this case, the positioning members 3A, 3B and the pressing members 3C, 3
It is not necessary to provide the inclined portion SP in D as shown in FIGS. 2 (a) and 2 (b).

Then, the laser beam projected in the horizontal direction is converged on the pattern surface 1a from the side of the XY stage 11, and the XY stage 11 is moved to scan the pattern surface 1a with the laser beam, and the pattern edge is scanned. The scattered light from the reticle 1 is detected by the detectors 20a to 20d, or the reflected light is detected by the light receiving element of the detection system 23 to detect the pattern of the reticle 1.

X when this pattern is detected
The position of the Y stage 11 is read by the X-axis interferometer 12a and the Y-axis interferometer 12b. In this way,
The pattern information detected by the detection system 23 and the interferometer 1
A plurality of pattern coordinates on the reticle 1 can be measured from the information on the position of the XY stage 11 read by 2a and 12b.

As described above, in the pattern coordinate measuring method according to the present invention, since the reticle 1 is mounted so as to be perpendicular to the horizontal line, the reticle 1 does not bend due to gravity. Therefore, by the pattern coordinate measuring method according to the present invention, it is possible to eliminate the error due to the influence of the deflection of the reticle 1 and accurately measure the pattern coordinates.

Next, a description will be given of a second embodiment of the pattern coordinate measuring method according to the present invention. FIG. 4 is a perspective view showing a pattern coordinate measuring device according to a second embodiment of the pattern coordinate measuring method according to the present invention. FIG.
In FIG. 5, illustration of the reticle holding device, which is shown in detail in FIGS. 5A and 5B, is omitted. As shown in FIG.
In the pattern coordinate measuring apparatus according to the embodiment, a holder 30 for holding the reticle 1 so as to be perpendicular to a horizontal line, and a reticle 1
Detection system 23 for detecting the pattern of
And an X-axis interferometer 12a and a Y-axis interferometer 12b for detecting the position of the XY stage 11. Detection system 23 is XY stage 1
The objective lens 21 is installed so as to move integrally with
A detection optical system 22 having a light receiving element for receiving light directly reflected from the pattern of the reticle 1; and a space between the objective lens 21 and the holder 30 in the X and Y axis directions. And detectors 20a to 20d for detecting scattered light from the pattern. The non-movable portion of the XY stage 11 is fixed on a platen (not shown) so as to be perpendicular to the horizontal line, and the holder 30 is perpendicular to the horizontal line with respect to a frame (not shown) fixed on the platen. It is fixed so that Then, FIGS. 5 (a) and 5 (b)
As shown in FIG. 2, a reticle 1 has positioning members 3A and 3B and pressing members 3C and 3C similar to those shown in FIGS. 2 (a) and 2 (b).
It is held on the holder 30 by 3D and a pressing mechanism similar to the springs 4A and 4B. As shown in FIGS. 6A and 6B, a vacuum suction pad may be provided on the holder 30 to perform vacuum suction.

In such a pattern coordinate measuring apparatus, the reticle 1 has a pattern surface 1a on the holder 30.
To the detection system 23 in the same manner as in the first embodiment. The XY stage 11 is moved while the laser beam projected from the light source in the horizontal direction is focused on the pattern surface 1a from the side of the holder 30 to scan the pattern surface 1a with the laser beam, and scattering from the pattern edge is performed. The pattern of the reticle 1 is detected by detecting light with the detectors 20a to 20d or detecting light directly reflected from the pattern with the light receiving element of the detection optical system 22.

X when this pattern is detected
The position of the Y stage 11 is read by the X-axis interferometer 12a and the Y-axis interferometer 12b. In this way,
The pattern information detected by the detection system 23 and the interferometer 1
A plurality of pattern coordinates on the reticle 1 can be measured from the information on the position of the XY stage 11 read by 2a and 12b.

Next, a description will be given of a third embodiment of the pattern coordinate measuring method according to the present invention. FIG. 7 is a perspective view showing a pattern coordinate measuring device according to a third embodiment of the pattern coordinate measuring method according to the present invention. In the measuring apparatus shown in FIG. 7, the reticle 1 is held on the stage by the holder 30 shown in FIGS. 2 (a) and 2 (b), but the illustration of the holder 30 is omitted in FIG. As shown in FIG. 7, the pattern coordinate measuring apparatus according to the third embodiment of the present invention includes an X stage 11a for placing a reticle 1 vertically on a horizontal line via a holder 30, and an X stage 1a.
1a, a detection system 23 for detecting the pattern of the reticle 1, a Y stage 11b to which the detection system 23 is fixed, and an X-axis interferometer 12a for detecting the position of the X stage 11a. And a Y-axis interferometer 12b for detecting the position of the Y stage 11b. Detection system 2
Reference numeral 3 denotes a detection optical system 22 that is installed so as to move integrally with the Y stage 11b, and includes an objective lens 21 and a light receiving element that receives light directly reflected from the pattern of the reticle 1.
And detectors 20a to 20a provided in the X and Y axis directions in a space between the objective lens 21 and the X stage 11a to detect scattered light from the pattern of the reticle 1.
0d. The non-movable portion of the Y stage 11b is fixed vertically to a horizontal line on a platen (not shown), and the non-movable portion of the X stage 11a is fixed to a horizontal line with a frame (not shown) fixed on the platen. Fixed vertically.

In such a pattern coordinate measuring apparatus, the reticle 1 is provided on the X stage 11a.
a is placed via the holder 30 toward the detection system 23 in the same manner as in the first embodiment. The laser beam projected in the horizontal direction from the light source is focused on the pattern surface 1a from the side of the X stage 11a while the X stage 11a
And the Y stage 11b is moved to scan the pattern surface 1a with a laser beam, and the scattered light from the pattern edge is detected by the detectors 20a to 20 or the light reflected directly from the pattern is detected by the detection optical system 22. The pattern of the reticle 1 is detected by detecting with the light receiving element.

X when this pattern is detected
The position of the stage 11a is determined by the X-axis interferometer 12a.
The position of the stage 11b is read by the Y-axis interferometer 12b. Thus, a plurality of pattern coordinates on the reticle 1 are measured from the pattern information detected by the detection system 23 and the position information of the X stage 11a and the Y stage 11b read by the interferometers 12a and 12b. It is possible.

In the third embodiment of the present invention, the reticle 1 is mounted on the X stage 11a via the holder 30.
And the detection system 23 is fixed to the Y stage 11b, but the X stage 11a and the Y stage 1
The positional relationship of 1b may be reversed, that is, the detection system 23 may be fixed to the X stage 11a, and the reticle 1 may be placed on the Y stage 11b via the holder 30.

In each of the above embodiments, a laser beam is focused on the pattern surface 1a, and scattered light from a pattern edge is detected by the detectors 20a to 20 or light reflected directly from the pattern is detected. The pattern of the reticle 1 is detected by detecting the light with the light receiving element of the detection optical system 22. A CCD camera is provided in the detection optical system 22, and the pattern image is formed on the imaging surface of the CCD camera. The pattern may be detected by a method of detecting the image signal by obtaining an image signal representing the image signal and performing image processing on the image signal. Further, any other pattern detection method may be used.

In the correspondence between the above embodiment and the claims, the reticle 1 is a substrate, the XY stage 11 and the X stage 11a are a mounting table, the detection system 23 is a pattern detection section, the X-axis interferometers 12a and Y The axis interferometer 12b constitutes a position detecting unit.

[0031]

As described above in detail, the method and apparatus for measuring pattern coordinates according to the present invention measure the pattern coordinates by placing the pattern surface of a substrate such as a reticle so as to be substantially perpendicular to the horizontal line. As a result, the substrate does not bend due to gravity. Therefore, the measured coordinate values of the pattern are those in which the influence of the bending of the substrate due to gravity is removed, and thus the coordinate values of the pattern can be accurately measured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a pattern coordinate measuring device according to a first embodiment of the present invention.

FIGS. 2A and 2B are views showing a holder for mounting a reticle on a stage, wherein FIG. 2A is a top view and FIG.

3A and 3B are diagrams illustrating another example of a holder for placing a reticle on a stage, wherein FIG. 3A is a top view and FIG. 3B is a side view.

FIG. 4 is a perspective view of a pattern coordinate measuring device according to a second embodiment of the present invention.

FIG. 5 is a view showing a holder for holding a reticle;
(A) is a top view, (b) is a side view

6A and 6B are diagrams showing another example of a holder for holding a reticle, wherein FIG. 6A is a top view, and FIG. 6B is a side view.

FIG. 7 is a perspective view of a pattern coordinate measuring device according to a third embodiment of the present invention.

FIG. 8 is a perspective view of a conventional pattern coordinate measuring device.

[Explanation of symbols]

 Reference Signs List 1 reticle (substrate) 1a pattern surface 3A, 3B positioning member 3C, 3D pressing member 4A, 4B spring 11 XY stage 11a X stage 11b Y stage 12a, 12b interferometer 14X, 14Y mirror 20a-20d detector 21 objective lens 22 detection Optical system 23 Detection system 30 Holder

Claims (8)

[Claims] 1. A method for measuring a coordinate of a pattern having a pattern formed on a surface thereof by mounting the substrate on a mounting table and detecting a pattern of the mounted substrate by a pattern detector. A pattern coordinate measuring method, wherein the substrate is mounted on the mounting table so that the pattern surface is substantially perpendicular to a horizontal line, and the pattern is detected by the pattern detection unit. 2. The apparatus according to claim 1, wherein the mounting table is an XY stage, wherein the pattern is detected by the pattern detection unit arranged on a side of the XY stage, and the position of the XY stage is detected when the pattern is detected. 2. The pattern coordinate measuring method according to claim 1, wherein the coordinates of the pattern are measured. 3. The XY stage disposed on the side of the mounting table, wherein the pattern detection unit is mounted, the pattern detection unit detects the pattern, and detects the position of the XY stage when the pattern is detected. 2. The pattern coordinate measuring method according to claim 1, wherein the coordinate of the pattern is measured by performing the following. 4. A substrate having a pattern formed on its surface is placed on an X stage such that the pattern surface is substantially perpendicular to a horizontal line, and is placed on a Y stage disposed on a side of the X stage. Detecting the pattern by a detected pattern detecting unit, and detecting the position of the X stage and the Y stage at the time of detecting the pattern by the pattern detecting unit, thereby measuring the coordinates of the pattern. . 5. An XY stage for mounting a substrate having a pattern formed on its surface such that the pattern surface is substantially perpendicular to a horizontal line, and an XY stage installed on a side of the XY stage to detect the pattern. A pattern detection unit; and a position detection unit that detects the position of the XY stage. The position of the XY stage is detected by the position detection unit when the pattern is detected by the pattern detection unit. A pattern coordinate measuring device characterized by measuring the following. 6. A mounting table for mounting a substrate having a pattern formed on its surface such that the pattern surface is substantially perpendicular to a horizontal line; an XY stage provided on a side of the mounting table; A pattern detection unit that is installed on an XY stage and detects the pattern; and a position detection unit that detects the position of the XY stage. The position detection unit detects the XY stage when the pattern detection unit detects the pattern. A pattern coordinate measuring device for measuring coordinates of the pattern by detecting a position of the pattern. 7. An X stage for mounting a substrate having a pattern formed on its surface such that the pattern surface is substantially perpendicular to a horizontal line; a Y stage provided on a side of the X stage; A pattern detection unit that is mounted on a Y stage and detects the pattern; and a position detection unit that detects the positions of the X stage and the Y stage. The position detection unit detects the pattern when the pattern detection unit detects the pattern. A pattern coordinate measuring device, wherein a coordinate of the pattern is measured by detecting a position of the X stage and a position of the Y stage by a detection unit. 8. A positioning member for pressing a horizontal side of the substrate in the direction of gravity and a vertical side adjacent to the horizontal side, and a biasing member for pressing the substrate against the positioning member via a pressing member. The positioning member and the pressing member are provided with an inclined surface which comes into contact with an edge on the front side of the substrate and presses the substrate toward the stage. A pattern coordinate measuring device according to any one of the preceding claims.