JPH11186155A - Estimation method of exposure performance, scanning type exposure system using the method, and device manufacture using the system. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an estimation method of exposure performance capable of highly precisely calculating the optimum exposure condition at a high speed, a scanning type exposure system using the method, and a device manufacturing method using the system. SOLUTION: Exposure performance is estimated in a scanning type exposure system transferring the pattern of an original sheet R to a substrate W, by synchronously moving the original sheet R and the substrate. In this case, the original sheet R on which estimation patterns R1, R2 are formed and the substrate W are synchronously moved along the synchronous movement direction by using the exposure system. Thereby the estimation pattern R1, R2 are transferred to the substrate W, and transfer error of estimation patterns transferred to the substrate is obtained. On the basis of measured result, the exposure performance of the aligner is estimated. While the original sheet R and the substrate are synchronously moved, the transfer error of estimation patterns transferred to the substrate W is obtained, and the exposure performance of the exposure system is estimated on the basis of measured result, so that a lot of shots are not necessarily required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating an exposure operation, a scanning type exposure apparatus and a method for manufacturing a device, and more particularly, to evaluating the exposure operation by obtaining a transfer error of a predetermined pattern transferred by the exposure operation. The present invention relates to an evaluation method, a scanning exposure apparatus using the method, and a device manufacturing method using the apparatus.

[0002]

2. Description of the Related Art In a method of manufacturing a device such as a semiconductor integrated circuit, for example, in a process such as a scanning type exposure, a circuit pattern drawn on a reticle by a reduction projection exposure apparatus is mainly transferred to a wafer or the like through a projection lens. The pattern is transferred onto a substrate, and a circuit pattern is formed on the substrate. Here, in the scanning exposure method using a slit, it is necessary to scan at a constant speed during the exposure, and for that purpose, the image plane illuminance during the scanning exposure must be kept at a constant value.

At the time of the transfer, the optimum image plane of the projection lens is detected and the height and inclination of the substrate are adjusted in accordance with the scanning accuracy so that the substrate is accurately set on the optimum image plane of the projection lens. If the adjustment is inaccurate, the projected image of the pattern on the reticle is not accurately formed on the substrate, and a blurred pattern is formed on the substrate, causing a problem such as poor resolution.

On the other hand, if the synchronous scanning accuracy between the reticle side and the substrate side is not set accurately in order to set one exposure area, that is, the exposure amount for each shot, the line width of the circuit pattern formed on the substrate is reduced. An error occurs between the target design line width and the desired characteristics cannot be finally satisfied. As described above, when the pattern is projected and exposed by the exposure apparatus, unless the exposure conditions such as the optimal exposure focal plane position of the projection lens and the optimal exposure amount are set accurately, the yield will be reduced.

Conventionally, in order to accurately evaluate and set such an exposure condition or an exposure operation, first, before the main exposure, at least one of the exposure amount and the stage focus surface is changed while the minimum line near the limit resolution is changed. A reference pattern consisting of a rectangular pattern having a width is sequentially exposed on the substrate by a plurality of shots, and a reference resist pattern image R21 formed in a matrix on the reticle R as shown in FIG. 9 is formed on the substrate. . Next, for each shot, the pattern image R
The width of the line forming the line 21 or the length of the line of the pattern image was measured using an electron microscope, and the optimum exposure focal plane and the optimum exposure amount of the projection lens were calculated.

[0006]

According to the above prior art, the line width is detected using an electron microscope.
The measurement took a lot of time. Further, in the conventional method as described above, a plurality of shots are projected and exposed in a matrix on the substrate while changing the exposure condition of the reticle reference pattern, and the line width or pattern length of the resulting resist pattern image is determined. Since detection must be performed, it takes a long time to calculate the optimal exposure condition.

In view of the above problems, the present invention provides a highly accurate and high-speed method for evaluating an exposure operation, a scanning exposure apparatus using such a method, and a device manufacturing method using such an apparatus. The purpose is to do.

[0008]

According to a first aspect of the present invention, there is provided a method of evaluating an exposure operation of a scanning type exposure apparatus, comprising the steps of: moving an original and a substrate synchronously; A method for evaluating an exposure operation of a scanning type exposure apparatus 10 (see FIG. 8) for transferring a pattern onto the substrate; using the scanning type exposure apparatus 10, evaluate patterns R1 and R2 along the direction of the synchronous movement. The evaluation patterns R1 and R2 are transferred onto the substrate W by synchronously moving the original R on which the R2 (see FIG. 1) is formed and the substrate W; a transfer error of the evaluation pattern transferred onto the substrate W Seeking;
The exposure operation of the scanning exposure apparatus 10 is evaluated based on the measurement result. Here, the original is a concept including a mask and a reticle, and the substrate is a concept including a wafer for an integrated circuit and a glass plate for a liquid crystal display device. The exposure operation to be evaluated is typically the accuracy of synchronous scanning, such as an error of a synchronous speed from a target design value, an error of a ratio of a synchronous speed between an original and a substrate, or a pitch of a substrate stage and thus a substrate. 7 (A)), rolling (FIG. 7 (B)), yawing (FIG. 7 (C)), etc., and the relative displacement between the substrate and the original in the scanning direction (FIG. 7).
(D)) is also included.

With this configuration, the transfer errors of the evaluation patterns R1 and R2 transferred onto the substrate W are obtained while the master R and the substrate W are synchronously moved, and the scanning exposure apparatus 10 is controlled based on the measurement results. Since the exposure operation is evaluated, it is not always necessary to expose a large number of shots.

In the above method, as described in claim 2,
It is preferable that the evaluation pattern is a linear pattern R2 formed continuously along the direction of the synchronous movement.

In this case, the error of the exposure operation appears as a change or inclination of the line width of the linear pattern. By detecting the error, the exposure operation can be evaluated. A continuously formed straight line is a solid line having a substantially uniform thickness,
Such a solid line may be a broken line intermittently interrupted.

According to a third aspect of the present invention, in the evaluation method of the first aspect, it is preferable that the evaluation pattern is a plurality of marks R1 formed at predetermined intervals along the direction of the synchronous movement.

In this case, the error in the exposure operation is detected as a change in the vertical width and the horizontal width, particularly the horizontal width (in the direction perpendicular to the synchronous movement direction) of the plurality of marks formed at a predetermined interval. This makes it possible to evaluate the exposure operation.

[0014] In the above method, as set forth in claim 4,
The plurality of marks formed at predetermined intervals along the direction of the synchronous movement are preferably formed in a wedge shape or rhombus R1, R11, respectively.

With this configuration, the sharp wedge-shaped or diamond-shaped tip of the mark is sensitive to the limit resolution.
An error in the exposure operation appears in a form in which the portion is chipped or rounded.

In the above-described evaluation method, it is preferable that the evaluation patterns are formed in a plurality of rows along the direction of the synchronous movement. In this case, an error in the exposure operation appears as a difference in pattern deformation between the plurality of rows. Here, the column indicates the direction of the synchronous movement, and the row indicates the direction orthogonal to the direction of the synchronous movement.

Further, as described in claim 6, claim 1 is
In the evaluation method described in (1), the transfer error of the evaluation pattern formed on the substrate may be obtained in correspondence with the position of the mask. Here, the position of the mask can be represented, for example, by the coordinates of the mask measured by an interferometer when the pattern is being transferred.

With this configuration, since the transfer error of the evaluation pattern on the substrate is obtained in correspondence with the position of the mask, the exposure operation can be evaluated according to the position of the mask, and the synchronization accuracy can be known.

According to a seventh aspect of the present invention, in the scanning exposure apparatus, the original R and the substrate W are synchronously moved to thereby make the original R
Is a scanning type exposure apparatus for transferring a pattern on a substrate W; evaluation patterns R1, R along the direction of the synchronous movement.
An exposure system for transferring the evaluation patterns R1 and R2 onto the substrate W by synchronously moving the original R on which the substrate 2 is formed and the substrate W; and the evaluation patterns R1 and R transferred onto the substrate W
2; measuring systems 11 and 12 for obtaining a transfer error; and an evaluation system 13 for evaluating an exposure operation of the scanning type exposure system based on the measurement results.

With this configuration, the exposure system can
Since the master and the substrate on which the evaluation pattern is formed are synchronously moved along the direction of the synchronous movement and the evaluation pattern is transferred onto the substrate, it is not necessary to expose a large number of shots. The operation error is reflected on the pattern image.

According to an eighth aspect of the present invention, there is provided a device manufacturing method, wherein the device is manufactured using the scanning exposure apparatus according to the seventh aspect.

With this configuration, the master on which the evaluation pattern is formed and the substrate are synchronously moved along the direction of the synchronous movement to transfer the evaluation pattern onto the substrate.
Since the errors in the exposure operation of the scanning exposure system are reflected in the pattern image without necessarily exposing a large number of shots, errors in the exposure operation can be detected and corrected in a short period of time. Can be manufactured.

According to the ninth aspect of the present invention, there is provided the evaluation method according to the first aspect.
The evaluation patterns R1 and R transferred to different positions on the substrate W with respect to the direction of the synchronous movement.
The exposure operation is evaluated based on each transfer error of No. 2.

According to a tenth aspect of the present invention, in the method of the fifth aspect, each of the evaluation patterns R1 and R2 transferred to different positions on the substrate W in a direction orthogonal to the direction of the synchronous movement. The exposure operation is evaluated based on the transfer error.

In the evaluation method according to the eleventh aspect, in the method according to the first aspect, the evaluation of the exposure operation includes at least one of a speed error and a focus error during the synchronous movement of the original R and the substrate W. To evaluate.

In the scanning exposure apparatus according to the twelfth aspect,
The apparatus according to claim 7, wherein the exposure system comprises:
The evaluation system includes an original stage RST that synchronously moves while supporting the original R and a substrate stage STG that synchronously moves while supporting the substrate W; the evaluation system performs the original stage RST during the synchronous movement between the original R and the substrate W And substrate stage STG
At least one of pitching, rolling, and yawing is evaluated.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding members are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows an example of an evaluation pattern used in the present invention. Here, the reticle R has a vertical direction in the drawing, that is, a direction along a linear pattern R2 described later is the scanning direction of the exposure apparatus. In the example of FIG. 1, a rhombus R1 as a plurality of marks formed at predetermined intervals is formed along the scanning direction, that is, the direction of the synchronous movement. The plurality of rhombic patterns R1 are formed such that the long sides of the rhombus are perpendicular to the scanning direction, and the short sides of the rhombus are superimposed on a virtual straight line facing the scanning direction. In FIG. 1, a virtual straight line directed in the scanning direction is indicated by a broken line. The predetermined interval may be an interval such that an appropriate number of rhombic patterns can be obtained for evaluating the exposure operation of the exposure apparatus in the scanning direction, for example, a length corresponding to one to five short sides of the rhombus. Good. Generally, it is preferable to use about three.

In the example of FIG. 1, a linear pattern R2 continuously formed in the scanning direction is arranged along a row of a plurality of rhombic patterns R1. In the example of FIG. 1, this pattern is shown as a straight line having a uniform thickness. Further, a linear pattern R2 formed continuously with a row of the pair of a plurality of rhombic patterns R1 is arranged at a predetermined interval in a plurality of pairs in a direction perpendicular to the scanning direction. As a result, these plural pairs of patterns cover almost the entire surface of the reticle R.

FIG. 2 is an enlarged view showing one rhombic pattern out of the evaluation patterns. FIG. 2A shows a pattern R1 formed as a diamond itself.
(B) is a graphic pattern R11 in which the bottom sides of two isosceles triangles (so-called wedges) formed by cutting the rhombus of (A) at the short sides are arranged facing each other at an interval. In the present invention, the graphic pattern R11 of (B) can be used in the same manner as the rhombic graphic pattern R1 of (A).

In FIG. 2, the ratio of the long side to the short side of the diamond is 3: 1.
The degree is not limited to this, but may be 4: 1 or 5: 1. The larger the ratio, the sharper the tip of the long side of the rhombus becomes, the more sensitive it becomes to the limit resolution of the projection optical system of the exposure apparatus, and the chipping or rounding of that portion becomes remarkable. Also, typically, the length of the short side of the diamond is set to be larger than the limit resolution. The end of the long side of the rhombus may be cut off, so to speak, a shape in which two trapezoids are joined at the bottom side. In this case, the length of the cut end of the long side along the scanning direction is set to be smaller than the limit resolution. .

Here, an example of the scanning exposure apparatus according to the present embodiment will be described with reference to FIG. In FIG. 8, light from the illumination optical system IU uniformly illuminates a reticle R, which is an original placed on a reticle stage RST.

Thus, an illumination area on the slit is formed on the reticle R. The Z axis is set in parallel with the optical axis of the projection optical system PL described later, and the Y axis is set in the scanning direction of the reticle R with respect to the illumination area (parallel to the paper) in a plane perpendicular to the optical axis. The X-axis is perpendicular to the scanning direction of the reticle R (perpendicular to the plane of the drawing) in a plane perpendicular to.

The reticle stage RST is provided movably along the Y direction, and a movable mirror 16 is fixed to one end of the reticle stage RST in the Y direction. The measuring beam from the laser interferometer 18 is reflected by the movable mirror 16, and the position of the reticle stage RST in the Y direction is constantly monitored by the laser interferometer 18. The position information of the reticle stage RST measured by the laser interferometer 18 is supplied to the control unit 14 that controls the entire apparatus. The control unit 14 drives the reticle stage driving device 20 to control the movement of the reticle stage RST.

A projection optical system PL is disposed on the side opposite to the illumination optical system IU with respect to the reticle stage RST.
Wafer stage S on which wafer W is mounted so that the exposure surface of wafer W, which is a substrate, is set at a position conjugate to the surface on which pattern of reticle R is formed with respect to projection optical system PL.
TG is arranged.

The wafer stage STG is provided so as to be movable at least in the Y direction, and a movable mirror 22 is fixed to one end of the wafer stage STG in the Y direction. The measurement beam from the laser interferometer 24 is reflected by the movable mirror 22, and the position of the wafer stage STG in the Y direction is constantly monitored. Wafer stage S measured by laser interferometer 24
The TG position information is supplied to the control unit 14. Control unit 14 drives wafer stage driving device 26 to control the movement of wafer stage STG.

When the wafer W is exposed by the scanning exposure method, the reticle R is moved in the + Y direction (−Y direction) by the reticle stage RST, and in synchronism with the −Y direction (or by the wafer stage STG). + Y direction). The projection magnification of the projection optical system PL is β (for example, 1 /
If the control unit 14 receives the position information of the reticle stage RST from the laser interferometer 18, the control unit 14 controls the reticle driving device 20 to move the reticle R to +.
The wafer W is moved in the Y direction by V / β, and while receiving the position information of the wafer stage STG from the laser interferometer 24, the wafer driving device 26 is controlled to move the wafer W in the −Y direction in synchronization with the movement of the reticle R. Move with V.

On the other hand, the exposure evaluation optical system 11 is so arranged that the wafer W mounted on the wafer stage STG can be observed.
Are provided above the wafer stage STG, on the same side as the projection optical system PL, and near the projection optical system PL. The exposure evaluation optical system 11 includes a two-dimensional sensor (not shown) inside. The exposure evaluation optical system 11 includes the optical system 1
An image processing unit 12 that processes the image captured by the first unit 1 is connected (for example, electrically) by a signal transmission line.
The image processing unit 12 is further connected with an image calculation unit 13 for measuring the shape of the processed image by a signal transmission line (for example, electrically (hereinafter, the same applies)). A control unit 14 that controls the movement of the reticle stage RST and the wafer stage STG is connected to the image calculation unit 13 via a signal transmission line.

Further, the position of each stage measured by the laser interferometers 18 and 24 can be input to the image calculation unit 13 via a signal transmission line (not shown).

With reference to FIG. 8, a method for evaluating the exposure operation of the above-described scanning type exposure apparatus will be described. The reticle R on which the evaluation pattern is formed and the wafer W are synchronously moved with respect to the slit exposure light irradiated by the illumination optical system IU. Thus, the evaluation pattern drawn on reticle R is projected and exposed on wafer W via projection optical system PL.

The wafer W exposed by the scanning exposure apparatus is carried out of the apparatus, and after being developed, is again mounted on the wafer stage STG of the scanning exposure apparatus. Then, the exposure evaluation pattern is measured by the exposure evaluation optical system 11.

In such an exposure evaluation optical system, the wafer W is illuminated with light from a light source, for example, a halogen lamp, and reflected light from the evaluation pattern transferred onto the wafer W is formed on a two-dimensional sensor. The image of the pattern is taken into the image processing unit 12, and the shape of the evaluation pattern is measured by the image calculation unit 13.

FIGS. 3 and 4 show the pattern of FIG.
An example of a pattern image when exposed above is shown. Ideally, the same reduced exposure pattern image as the pattern in FIG. 1 should be formed on the wafer W. 3 and 4 show a pattern image and a detection signal in such an ideal case.

FIG. 3 shows three pairs of rhombus pattern R1 and straight line pattern R2 extracted. One rhombus pattern image R1 is extracted in the column direction and three in the row direction. The upper and lower portions of the linear pattern R2 are omitted. FIG. 3 shows three rhombic patterns R
In this case, one long side is arranged on the same straight line A1-A2 in a direction (row direction) orthogonal to the scanning direction of the exposure device, that is, in a direction orthogonal to the linear pattern R2. A1-A2
When the pattern image is measured in accordance with, the pattern image is an ideal case, and therefore, becomes a regular signal as shown as an A1-A2 detection signal. Here, for convenience, the code of the image of the pattern formed on the substrate W is the same as the code of the pattern on the corresponding original R
1, R2 is used.

FIG. 4 shows three rhombic patterns R1 which are continuous in the scanning direction (column direction). Here, the short sides of the three rhombuses are straight lines D1-
It is on D2. The straight line B1-B2 is drawn at a position slightly away from the left end of the long side of the rhombus in FIG.
It is a straight line parallel to D2, and the straight line F1-F2 is drawn at a position slightly away from the right end of the long side of the diamond in the figure.
This is a straight line parallel to the straight line D1-D2. Also, a straight line C1-
C2 is a straight line parallel to the straight line D1-D2, drawn in the middle between the straight line D1-D2 and the straight line B1-B2, and the straight line E1
-E2 is a straight line parallel to the straight line D1-D2, drawn in the middle between the straight line D1-D2 and the straight line F1-F2.

FIG. 4 shows detection signals B1-B2, C1-C2, D1-D2, E when the pattern image is measured.
1-E2 and F1-F2. These are regular signals because the pattern image is shown in the ideal case in the figure.

If the synchronization accuracy between the reticle R and the wafer W does not match, the shape of the pattern that should be formed on the wafer W is lost.

FIGS. 5 and 6 show an example of such a case where the pattern is broken. FIG. 5 shows two pairs of images of the diamond-shaped pattern R1 and the linear pattern R2 (R1
a, R2a, R1b, R2b) are extracted and shown. FIG. 5 shows that the long sides of the two rhombic patterns R1 are arranged on the same straight line H1-H2 in the direction orthogonal to the scanning direction of the exposure device, that is, the direction orthogonal to the linear pattern R2. If it is. In the case of FIG. 5, the tip of the long side of the diamond-shaped pattern image R1a is rounded. The next linear pattern image R2a is missing the right side in the figure, and the straight line is narrow at that portion. The next rhombus pattern image R1b keeps a shape almost close to the ideal shape. Similarly, the next straight-line pattern image R2b also keeps a shape almost similar to the ideal shape.

When such a pattern image is measured along a straight line H1-H2 in a direction orthogonal to the scanning direction, the pattern image is deformed as described above.
As shown in the -H2 detection signal, the length of the portion corresponding to the rhombic pattern image R1a is
The length is shorter than the length of the portion corresponding to 1b. This is because the tip of the long side is cut off and the long side is shortened. Similarly, the length of the portion corresponding to the linear pattern image R2a is shorter than the length of the portion corresponding to the linear pattern image R2b. This is because the right side of the straight line pattern image R2a sags and the width of the straight line becomes narrow.

As described above, by performing the shape measurement of the patterns arranged in the direction orthogonal to the scanning direction, it is possible to know the pattern transfer error corresponding to the position of the reticle R during the synchronous movement.

FIG. 6 shows the extracted images of four rhombic patterns R1 which are continuous in the scanning direction (R1c, R1).
d, R1e, R1f). Here, the short sides of the four rhombic images are
It is on a straight line K1-K2 substantially oriented in the scanning direction. Straight line I
1-I2 is a straight line parallel to the straight line K1-K2 drawn at a position slightly away from the left end of the long side of the diamond in the figure, and the straight line M1-M2 is a straight line of the long side of the diamond in the figure. This is a straight line parallel to the straight line K1-K2, which is drawn at a position slightly away from the right end. The straight line J1-J2 is a straight line K1-K
2 and the straight line K1-K drawn between the straight lines I1-I2.
2 and a straight line L1-L2 is a straight line K1-
A straight line K1- drawn between K2 and a straight line M1-M2.
This is a straight line parallel to K2.

The rhombus pattern image R1c of FIG. 6 has a shape almost ideal. In the pattern image R1d below the figure, the left end on the long side is close to ideal but the right end is rounded. The next pattern image R1e keeps a figure that is almost ideal. The next pattern image R1f lacks the left end on the long side. However, the portion up to the straight line J1-J2 is the same as the ideal figure. The right end is rounded.

FIG. 6 shows the detection signals when the pattern image is measured as I1-I2, J1-J2, K1-K2, L
1-L2, M1-M2. The pattern image shown in the figure is deformed as described above. Straight line I
In any case, the detection signal along 1-I2 is a straight line I1
-It is flat because I2 does not cover the rhombus figure. Since the detection signal along the straight line J1-J2 is not applied to the deformed portion of the rhombus, the signal changes regularly. The detection signal along the straight line K1-K2, that is, the short side of the rhombus has a substantially regular signal change. The detection signal along the straight line L1-L2 is the pattern R1
c has a normal signal level because there is no deformation,
The tip of the long side of the pattern R1d is rounded, and the straight line L
Since 1-L2 glides through it, the signal level is low. Since the next pattern R1e has an almost ideal shape, the signal level indicates a normal value. In the next pattern R1f, the right end of the long side is straightened and straight line L1 is formed.
Since the portion related to -L2 is missing, the signal is flat. Since the straight line M1-M2 does not overlap the rhombus figure, the signal is entirely flat.

Next, referring to FIG. 7, the transfer error of the linear pattern, that is, the change of the linear pattern image is obtained, and the reticle R
Reticle R out of synchronization errors during synchronous movement between wafer and wafer W
The relative pitch between the wafer and the wafer W, pitching, rolling, yawing, and skew (when the synchronous movement direction of the reticle R and the wafer W is relatively inclined with respect to the original direction), and Explain how to evaluate the behavior.

FIG. 7A shows a case where the wafer stage STG on which the wafer W is mounted is pitched during the synchronous movement. The direction of scanning is indicated by Y1. Due to this pitching, the linear pattern periodically repeats thick and thin. In this case, since it is assumed that a transfer error other than pitching has not occurred, the two parallel linear pattern images transferred in the drawing have the same change.

FIG. 7B shows a case where wafer stage STG on which wafer W is mounted is rolling during synchronous movement. The direction of scanning is indicated by Y2. Because of the rolling, the straight line pattern repeats thick and thin, but the two parallel straight line pattern images transferred in the figure change when one is thick, the other becomes thin.

FIG. 7C shows a case where wafer stage STG on which wafer W is mounted is yawing during synchronous movement. The direction of scanning is indicated by Y3. Although the straight line pattern meanders due to yawing, the two parallel straight line pattern images transferred in the figure have the same change in parallel.

FIG. 7D shows a case where the reticle R and the wafer W are relatively skewed and synchronously moved. The direction of the scan is indicated by X4. Although the straight line pattern is inclined due to the skew, the two parallel straight line pattern images transferred in the figure are skewed in parallel in exactly the same direction.

As described above, the image signal is linked to the shape of the collapsed pattern image and becomes an asymmetric shape. Actually, pitching, rolling, yawing, and skew rarely appear completely alone as described above, but appear in combination. However, by observing and analyzing a plurality of pattern images, it is possible to determine what abnormality has occurred in the synchronous movement of the reticle R and the wafer W, and to evaluate the exposure operation.

In the diamond-shaped pattern shown in FIG. 10, the vertical width a and the horizontal width b of the pattern transferred onto the wafer W depend on the speed error during the synchronous movement of the reticle R and the wafer W and the focus state. Changes. Therefore, by measuring these widths by the image calculation unit 13, it is possible to detect a speed error and a furcus error during the synchronous movement.

By measuring or obtaining the above-described transfer error, the transfer error is compared with the relation data between the evaluation pattern width and the scan speed / focus position by the image calculation unit 13, and the difference from the initially set apparatus parameter is determined. A new device parameter is added.

At the same time, the exposure amount may be controlled by controlling the amount of exposure light and the synchronous movement speed as one of the apparatus parameters. This makes it possible to easily and quickly measure the offset amount of the exposure apparatus, set preferable exposure conditions, and obtain a stable line width.

As described above, the evaluation reticle used in the present invention is generally a test reticle for inspecting the exposure conditions of the scanning type exposure apparatus, and is close to the limit resolution of the inspection type scanning exposure apparatus. It can be said that a predetermined pattern having a plurality of predetermined portions having a thickness is such that the predetermined portions are arranged in a predetermined direction on the reticle.
Further, the predetermined pattern may be a graphic having a taper, wherein a minimum width part of the taper is smaller than the limit resolution and a maximum width part is larger than the limit resolution.

Further, the predetermined pattern may include a plurality of straight lines having a substantially uniform thickness and extending over substantially the entire length of the reticle in the scanning direction.

Placing the evaluation reticle on the reticle stage such that the predetermined direction substantially matches the scanning direction of the scanning exposure apparatus to be inspected; and And performing a scanning exposure of the predetermined pattern on the substrate through the method.

Further, a semiconductor device can be manufactured by subjecting a product pattern to scanning exposure using a scanning exposure apparatus inspected by this inspection method.

[0067]

As described above, according to the present invention, the transfer error of the evaluation pattern transferred onto the substrate is determined while moving the original and the substrate synchronously, and the exposure of the scanning type exposure apparatus is performed based on the measurement result. Since the operation is evaluated, the exposure operation can be evaluated with high accuracy and high speed without necessarily exposing a large number of shots. In addition, a device can be manufactured by evaluating an exposure operation at high accuracy and at high speed, correcting an error if any, and performing exposure.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a pattern used for carrying out the present invention.

FIG. 2 is a diagram showing an example of a plurality of marks formed at predetermined intervals in a pattern used for implementing the present invention.

3 is a diagram showing a signal obtained by detecting an image transferred with high synchronization accuracy using the pattern shown in FIG. 1 in a direction orthogonal to a scanning direction by an exposure evaluation optical system.

FIG. 4 is a diagram showing a signal obtained by detecting an image transferred with high synchronization accuracy using the pattern shown in FIG. 1 in a scanning direction by an exposure evaluation optical system.

FIG. 5 shows an image transferred by being deformed by a synchronization accuracy error using the pattern shown in FIG.
FIG. 4 is a diagram illustrating a signal detected in a direction orthogonal to a scanning direction.

FIG. 6 illustrates an image transferred by being deformed by the synchronization accuracy error using the pattern shown in FIG.
FIG. 4 is a diagram illustrating a signal detected in a scanning direction.

FIG. 7 is a diagram illustrating an example of an image transferred using a linear pattern oriented in a scanning direction and deformed by pitching, rolling, yawing, skew, or the like.

FIG. 8 is a schematic side view of a scanning exposure apparatus according to an embodiment of the present invention.

FIG. 9 is a diagram showing a shot pattern used in a conventional synchronization accuracy evaluation method.

FIG. 10 is a plan view showing extracted rhombic patterns used in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Scanning exposure apparatus 11 Exposure evaluation optical system 12 Image processing unit 13 Image calculation unit 14 Control unit IU Illumination optical system PL Projection optical system R Reticle R1, R2, R11 Evaluation pattern RST Reticle stage W Wafer STG stage

Claims (12)

[Claims] 1. A method for evaluating an exposure operation of a scanning exposure apparatus for transferring a pattern of an original onto a substrate by synchronously moving an original and a substrate; Transferring the evaluation pattern onto the substrate by synchronously moving the master on which the evaluation pattern is formed and the substrate along the direction of the synchronous movement; obtaining a transfer error of the evaluation pattern transferred onto the substrate; An evaluation method, comprising: evaluating an exposure operation of the scanning exposure apparatus based on a measurement result. 2. The evaluation method according to claim 1, wherein the evaluation pattern is a linear pattern formed continuously along the direction of the synchronous movement. 3. The evaluation method according to claim 1, wherein the evaluation pattern is a plurality of marks formed at predetermined intervals along a direction of the synchronous movement. 4. The evaluation method according to claim 3, wherein the plurality of marks formed at predetermined intervals along the direction of the synchronous movement are each formed in a wedge shape or a rhombus shape. 5. The evaluation method according to claim 1, wherein the evaluation patterns are formed in a plurality of rows along the direction of the synchronous movement. 6. The evaluation method according to claim 1, wherein a transfer error of the evaluation pattern formed on the substrate is obtained in correspondence with a position of the mask. 7. A scanning exposure apparatus for transferring a pattern of an original onto the substrate by synchronously moving the original and a substrate; and an original on which an evaluation pattern is formed along the direction of the synchronous movement. An exposure system for synchronously moving the substrate and transferring the evaluation pattern onto the substrate;
A scanning exposure apparatus, comprising: a measurement system for obtaining a transfer error of an evaluation pattern transferred onto the substrate; and an evaluation system for evaluating an exposure operation of the exposure system based on the measurement result. 8. A device manufacturing method using the scanning exposure apparatus according to claim 7. 9. The evaluation according to claim 1, wherein the evaluation of the exposure operation is performed based on a transfer error of each of the evaluation patterns transferred to different positions on the substrate with respect to the direction of the synchronous movement. Method. 10. The exposure operation is evaluated based on transfer errors of evaluation patterns transferred to different positions on the substrate in a direction orthogonal to the direction of the synchronous movement. Evaluation method described in. 11. The evaluation method according to claim 1, wherein the evaluation of the exposure operation evaluates at least one of a speed error and a furcus error during the synchronous movement between the original and the substrate. 12. The exposure system includes an original stage that supports the original and moves synchronously, and a substrate stage that supports the substrate and moves synchronously. The scanning exposure apparatus according to claim 7, wherein at least one of pitching, rolling, and yawing of at least one of the original stage and the substrate stage during the synchronous movement is evaluated.