JP2001135559A - Position measuring method and exposing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to increase a throughput by reducing a measuring time while a plurality of positional measuring marks are measured. SOLUTION: In a measuring method, positional information of second fine alignment marks on a substrate are measured to calculate positional information of manufacturing points after a first searching alignment mark formed on the substrate is detected. The second mark nearest to the manufacturing point to be processed at first is set as the last one in measurement order out of the manufacturing points in the position information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sequentially transferring a mask pattern image to each shot area on a photosensitive substrate (such as a wafer) based on array coordinates predicted using, for example, a statistical method. The present invention relates to a position measurement method and an exposure method suitable for use in measuring the position of an area.

[0002]

2. Description of the Related Art When a semiconductor device or a liquid crystal display device is manufactured by a photolithography process, a pattern image of a photomask or a reticle (hereinafter collectively referred to as a "reticle") is formed on a photosensitive substrate through a projection optical system. A projection exposure apparatus that projects onto a shot area is used. recent years,
In this type of projection exposure apparatus, a photosensitive substrate is placed on a two-dimensionally movable stage, and the photosensitive substrate is step-moved by this stage so that a reticle pattern image is projected onto each shot area on the photosensitive substrate. An exposure apparatus of a so-called step-and-repeat system, for example, an exposure apparatus (stepper) of a reduction projection type, which repeats an operation of sequentially exposing, is frequently used.

[0003] For example, a semiconductor device is formed as a photosensitive substrate by laminating a large number of circuit patterns on a wafer coated with a photosensitive material. In such a method, it is necessary to precisely align each shot area on which a circuit pattern has already been formed on the wafer with the pattern image of a reticle to be exposed, that is, the alignment (alignment) between the wafer and the reticle.

For example, Japanese Patent Application Laid-Open No. 61-44429 discloses a method of aligning wafers when performing overlay exposure on one wafer on which circuit patterns (shot areas) are arranged in a matrix. The so-called enhanced global alignment (EGA) disclosed in US Pat. The EGA method designates at least three regions (hereinafter referred to as EGA shots) among a plurality of shot regions (partition regions) formed on a wafer, and coordinates of alignment marks (marks) attached to each shot region. The position is measured with an off-axis alignment system. Then, based on the measured values and the design values, error parameters (offset, scale,
(Rotation, orthogonality) is determined by statistical calculation using the least squares method or the like. Then, based on the determined parameter values, the design coordinate values of all shot areas on the wafer are corrected, and the wafer stage is moved off-axis with the projection optical system according to the corrected coordinate values. In this method, a wafer is positioned by performing stepping using a baseline amount that is a distance from an alignment system. As a result, the projected image of the reticle pattern and each of the plurality of shot areas on the wafer are processed points (reference points whose coordinate values are measured or calculated;
For example, the exposure is performed while being superposed accurately at the center of the shot area.

The wafer loaded on the wafer stage is placed in a pre-aligned state, but is not positioned at a level at which EGA measurement as fine alignment can be performed. For this reason, usually, so-called search alignment, in which the wafer is roughly adjusted to the extent that it does not interfere with the EGA measurement, is performed before the EGA measurement is performed. In the search alignment, a search alignment mark is measured in a predetermined shot area (for example, two places, hereinafter referred to as a search shot), and the coordinate value of the shot area is corrected based on the measurement result.

[0006]

However, the conventional position measurement method and exposure method as described above have the following problems. Search alignment and E
The GA measurement involves movement of the wafer stage for each shot area, but the measurement order does not take into account the movement distance of the wafer stage, and the path is not always the shortest distance. Therefore, the time required for position measurement including the time required for the wafer stage to move to the measurement position increases, and there is a problem in that the throughput is deteriorated.

In particular, when transitioning from search alignment to EGA measurement, the positional relationship between the search shot and the EGA shot should be taken into consideration. Conventionally, special consideration has been given to these positional relationships. And there was room for improvement in productivity. Further, when the sensor for performing the search alignment and the sensor for performing the EGA measurement are different from each other, a time for moving the wafer between the two sensors and a time for moving the wafer to the exposure position after the end of the EGA measurement are generated. Was not reflected in deciding.

[0008] The present invention has been made in consideration of the above points, and can be used to measure a plurality of position measurement marks.
It is an object of the present invention to provide a position measurement method and an exposure method that minimize the time required for measurement and contribute to an improvement in throughput.

[0009]

In order to achieve the above-mentioned object, the present invention employs the following structure corresponding to FIGS. 1 to 3 showing an embodiment. According to the position measurement method of the present invention, after detecting a first mark (XSM, YSM) for search alignment formed on a substrate (W), position information on a plurality of processing points (PA) on the substrate (W) is detected. Are calculated, a plurality of fine alignment second marks (XEM, YE) formed on the substrate (W).
M) In the position measurement method for measuring the position information, the second mark (XEM, YEM) closest to the processing point to be processed first among the plurality of processing points is set last in the measurement order of the position information, and The second mark (XEM, YEM) closest to one mark (XSM, YSM) is set first in the measurement order of position information.

Therefore, in the position measuring method of the present invention, the first
After the mark (XSM, YSM) is detected and search alignment is performed, the distance by which the substrate (W) is moved to perform fine alignment using the second mark (XEM, YEM) can be minimized. Also, the second
After the fine alignment is performed using the marks (XEM, YEM), the distance for moving the substrate (W) to the processing point to be processed first can be minimized.

The position measuring method of the present invention calculates a plurality of marks (XSM) formed on the substrate (W) in order to calculate position information on a plurality of processing points (PA) on the substrate (W). , YSM, XEM, YEM) in a position measurement method for measuring position information, when a processing point to be processed first among a plurality of processing points among a plurality of marks is arranged at the processing position or its preparation position, The mark (XEM, YE
M) is set at the end of the measurement order of the position information.

Therefore, in the position measuring method of the present invention, after measuring the position information of the mark (XEM, YEM), the processing point to be processed first is set to the processing position or its preparation position by moving the substrate (W). Can be as short as possible.

The position measuring method according to the present invention relates to a method for detecting a plurality of processing points on a substrate (W) after detecting first search alignment marks (XSM, YSM) formed on the substrate (W). In order to calculate position information, in a position measurement method for measuring position information of a plurality of second marks (XEM, YEM) for fine alignment formed on a substrate (W), a first of a plurality of processing points is used. Mark (XEM, YE) closest to the processing point to be processed
M) is set at the end of the position information measurement order, and the second mark (X
EM, YEM) are set first in the order of measurement of position information, and all measurement paths of a plurality of second marks (XEM, YEM) for measuring position information are obtained, and the shortest of all measurement paths is obtained. One of the second measurement modes in which the measurement path is the measurement order of the position information is selected according to the number of the plurality of second marks (XEM, YEM) for measuring the position information,
The position information is measured based on the one measurement mode.

Therefore, according to the position measuring method of the present invention, for example, when the number of the second marks (XEM, YEM) for measuring the position information is large, the first mark (XSM, YSM) is changed to the second mark (XEM, YEM). ), Second mark (XEM, Y
Since the distance to move between the second marks is longer than the distance to move from the EM) to the processing point, the second measurement mode is selected. Conversely, when the number of the second marks (XEM, YEM) is small, the second measurement mode is selected. Since the distance from the first mark to the second mark and the distance from the second mark to the processing point are longer than the distance between the two marks, the first measurement mode is selected, so that the movement distance of the substrate (W) Can be minimized.

The exposure method according to the present invention is directed to claim 23.
In order to transfer the pattern of the mask (R) to each of the divided areas on the substrate (W) by measuring the position information of at least three divided areas on the substrate (W) using the position measurement method described in Using the measured position information, the position information of each partitioned area on the substrate (W) is calculated, and the mask (R) and the substrate (W) are relatively moved based on the calculated position information, The method is characterized in that each divided area is exposed through a mask (R).

Therefore, according to the exposure method of the present invention, it is possible to measure the position information of each partitioned area in a short time before exposing each partitioned area of the substrate (W), thereby improving the throughput of the exposure processing. Can be done.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a position measuring method and an exposure method according to the present invention will be described below with reference to FIGS. Here, for example, when exposing a circuit pattern on a reticle to a plurality of shot areas (partition areas) on a wafer for manufacturing semiconductor devices, position information of each shot area on the wafer is calculated. It will be described using FIG. At this time, after the search alignment marks in the two search shots formed on the wafer are measured and the wafer is roughly adjusted, the six EGAs are adjusted.
It is assumed that EGA measurement (fine alignment) is performed using a fine alignment mark in a shot.

FIG. 1 is a schematic configuration diagram of the exposure apparatus 1.
Illumination light emitted from a light source 2 such as an ultra-high pressure mercury lamp or excimer laser is reflected by a reflecting mirror 3 and enters a wavelength selection filter 4 that transmits only light having a wavelength required for exposure. The illumination light transmitted through the wavelength selection filter 4 is an optical integrator (fly-eye lens or rod)
The light beam is adjusted to have a uniform intensity distribution by 5 and reaches a reticle blind (field stop) 6. In the reticle blind 6, a plurality of blades defining the opening S are driven by a drive system 6a, respectively, and the size of the opening S is changed to set an illumination area on the reticle R by the illumination light.

The illumination light passing through the opening S of the reticle blind 6 is reflected by a reflecting mirror 7 and enters a lens system 8. The image of the opening S of the reticle blind 6 is formed on the reticle R held on the reticle stage 20 by the lens system 8, and a desired area of the reticle R is illuminated. In FIG. 1, an illumination optical system is configured by the wavelength selection filter 4, the optical integrator 5, the reticle blind 6, and the lens system 8. The reticle stage 20 can be moved two-dimensionally in a plane perpendicular to the optical axis of the projection optical system 9, and
The position and the rotation amount of the (reticle R) are detected by a laser interferometer (not shown), and the measurement value (position information) of the laser interferometer is transmitted to a stage control system 14 and a main control system 1 described later.
5 and the alignment control system 19.

The image of the circuit pattern and / or alignment mark existing in the illumination area of the reticle R is formed on the wafer (substrate) W coated with the resist by the projection optical system 9. Thereby, the wafer stage (stage)
The pattern image and / or alignment mark image of the reticle R is exposed on a specific area (shot area) on the wafer W mounted on the wafer 10.

The wafer stage 10 has a wafer holder (not shown) for vacuum-sucking the wafer W, and is driven by a driving device 11 such as a linear motor in an X direction and a Y direction perpendicular to the optical axis of the projection optical system 9 and orthogonal to each other. (First and second directions). Thereby, the wafer W is two-dimensionally moved on the image plane side with respect to the projection optical system 9, and a reticle is formed on each shot area on the wafer W by, for example, a step-and-repeat method (or a step-and-scan method). The R pattern image is transferred.

A stage movement coordinate system (orthogonal coordinate system)
The position of the wafer stage 10 (wafer W) in the X and Y directions on XY, and the amount of rotation (the amount of yawing, the amount of pitching,
The rolling amount is detected by a laser interferometer 13 that irradiates a movable mirror (reflecting mirror) 12 provided at an end of the wafer stage 10 with laser light. The measurement value (position information) of the laser interferometer 13 is transmitted to the stage control system 14, the main control system 1
5 and the alignment control system 19. The stage control system 14 controls the driving device 11 based on position information from the main control system 15 and the laser interferometer 13 and the like.
The movement of the reticle stage 20 and the movement of the wafer stage 10 are respectively controlled via such as. The main control system 15 controls the size and shape of the opening S of the reticle blind 6 via the drive system 6a, and performs EGA calculation based on the position information of the alignment mark on the wafer W output from the alignment control system 19. In addition to this, it controls the entire system.

The exposure apparatus 1 includes, for example, a reticle alignment sensor 16 of a TTR (through-the-reticle) type and a wafer alignment sensor 17 of an off-axis type in order to align the reticle R with the wafer W. Is provided.

The reticle alignment sensor 16 detects a reference mark on the reference mark member 18 via an alignment mark formed on the reticle R and the projection optical system 9 using, for example, exposure illumination light. In the exposure light alignment method, the positional relationship can be directly observed by displaying an alignment mark and a reference mark of the reticle R on a monitor using an image sensor (CCD). The reference mark member 18 is fixed on the wafer stage 10, and has a reference mark formed at the same height as the surface of the wafer W.

The reticle alignment sensor 16 outputs an image signal of the alignment mark and the reference mark of the reticle R to the alignment control system 19. The alignment control system 19 detects the amount of displacement between the two marks based on the imaging signal, and also inputs the measurement values of the laser interferometer 13 and the like for detecting the positions of the reticle stage 20 and the wafer stage 10, respectively. Reticle stage 20 when the displacement amount of the reticle becomes a predetermined value, for example, zero
And each position of the wafer stage 10. Thereby, the position of reticle R on wafer stage movement coordinate system XY is detected. In other words, the correspondence between reticle stage movement coordinate system and wafer stage movement coordinate system XY (that is, detection of relative positional relationship) is performed. The alignment control system 19 outputs the result (position information) to the main control system 15.

As an alignment method of the off-axis type wafer alignment sensor 17, an FIA method,
An LSA method, an LIA method, or an exposure light alignment method using exposure light can be applied. As the wafer alignment sensor 17, a photoelectric conversion element such as an SPD is used in the LSA method and the LIA method, and an imaging element such as a CCD camera is used in the FIA method. Of these methods, the present embodiment employs the FIA method.

That is, the wafer alignment sensor 17 uses an objective optical system provided separately from the projection optical system 9 to provide illumination light in a wavelength range in which the resist on the wafer W is not exposed, for example, a wavelength of about 550 to 750 nm. The alignment mark on the wafer W is irradiated with the broadband light (broadband light), and the image sensor (CC) is passed through the objective optical system.
The image of the alignment mark is formed together with the image of the index mark on the light receiving surface of D), and the imaging signals (image signals) of both mark images are output to the alignment control system 19. Further, the wafer alignment sensor 17 has an AF (auto focus) function, that is, a function of detecting position information of the wafer W in a direction along the optical axis of the objective optical system described above, and based on the position information, By driving the stage 10, the alignment marks on the wafer W can be arranged on the focal plane of the objective optical system.

The alignment control system 19 detects the amount of displacement between the two marks based on the image pickup signal from the wafer alignment sensor 17 and also inputs the measured value of the laser interferometer 13 so that the amount of displacement is a predetermined value. For example, the position of the wafer stage 10 when it becomes zero is determined as the coordinate value of the alignment mark on the wafer stage movement coordinate system XY, and the position information is output to the main control system 15. The main control system 15 gives an instruction regarding the signal processing conditions and the like to the alignment control system 19, and performs the EGA calculation based on the position information (coordinate values) of the alignment mark output from the alignment control system 19, that is, The position information (coordinate value) of each shot area (a reference point, for example, a shot center) on the wafer W is calculated. Further, the main control system 15 corrects the calculated coordinate values based on the baseline amount of the wafer alignment sensor 17 and outputs the corrected coordinate values to the stage control system 14. The stage control system 14 controls the movement of the wafer stage 10 via the driving device 11 based on the position information from the main control system 15. Thus, for example, in a step-and-repeat method (or a step-and-scan method)
The pattern image of the reticle R is transferred to each shot area on the wafer W.

The wafer alignment sensor 17 is not limited to the off-axis type, but may be a TTL (through-the-lens) type for detecting an alignment mark on the wafer W via the projection optical system 9 or a reticle R. A TTR (through-the-reticle) system for detecting an alignment mark on a wafer through the projection optical system 9 and the projection optical system 9 may be used. Further, the wafer alignment sensor 17
Is a TTL system or a TTR system, a single-wavelength laser beam (He-Ne) is used as alignment illumination light.
Laser, etc.), multi-wavelength light, broadband light, exposure light, etc. may be used.
PD or the like may be used.

An input unit 21 for inputting various exposure data is connected to the main control system 15. As the exposure data, the positions of a plurality of shot areas, the order of exposure, the positions of search shots and EGA shots, the positions of search marks and alignment marks, and the like are input. Then, the main control system 15 determines a measurement order for performing the search alignment and the EGA measurement using the input exposure data.

Next, the wafer W of the present embodiment will be described. A plurality of shot areas (partition areas, processing points) are arranged in a matrix on the wafer W, and a chip pattern is formed in each shot area by exposure (processing) and development in a previous process. . In FIG. 2A, six EGs in these shot areas are used.
Only the A shots ES1 to ES6 and the two search shots SS1 and SS2 are shown as representatives.

As shown in FIG. 2B, in each of the shot areas ES1 to ES6 and SS1 to SS2, the first mark for search alignment is located at the outer corner of each pattern area (working point) PA. A Y search mark YSM for the Y direction (second direction) and an X search mark XSM for the X direction (first direction) are formed, and an alignment mark (second mark) for EGA measurement as fine alignment. As Y mark YEM for Y direction and X for X direction
A mark XEM is formed for each region.

The search marks YSM and XSM are one-dimensional marks arranged in parallel with a plurality of line patterns (three in FIG. 2B) consisting of a plurality of dots, spaced in the Y and X directions. Has become. The distance between the line patterns in each search mark is set asymmetrically so as to be different from each other so as to be distinguishable from a circuit pattern or the like. Note that these search marks YSM, X
SM can be applied even when the wafer alignment sensor 17 is an alignment system of a two-beam interference type or an alignment system of a laser step alignment type. In the search marks XSM and YSM, for example, a linear bar pattern may be used instead of a line pattern composed of a plurality of dots. Furthermore, search mark X
A mark configuration for two-dimensional direction detection combining SM and YSM may be used. In FIG. 2A, the number of search marks XSM and YSM is three, but any number may be used as long as it is one or more. In addition, search mark XS
Instead of making the mark interval of M and YSM different, the mark interval may be made uniform and the pattern length in the longitudinal direction (the direction orthogonal to the arrangement direction) may be made partially different.

The Y mark YEM and the X mark XEM are line-and-line, which are one-dimensional marks in which lines extending in the X direction and the Y direction are arranged in parallel in the Y direction and the X direction at equal distances. It is composed of space patterns. The search marks YSM and XSM are formed to be longer than the Y mark YEM and the X mark XEM so that they can be detected even if the pre-alignment accuracy of the wafer W is rough.

Next, a procedure for determining the measurement order of the search mark and the alignment mark will be described with reference to the flowchart shown in FIG. Here, among all the shot areas on the wafer W, the ES
It is assumed that six (m) of 1 to ES6 are set. The number of EGA shots is six if three or more.
It is not limited to an individual.

When the operator finishes inputting and editing the shot area size, step pitch (shot interval), search shot and EGA shot positions, search mark and alignment mark positions, etc. from the input unit 21 (step S1). The main control system 15 immediately starts the measurement sequence determination sequence. First, when the first shot area to be first exposed (processed) is at the exposure position (processing position) or its preparation position, the EGA shot at the position detected by the wafer alignment sensor 17 or the closest EGA shot is taken as the first shot. And the measurement order N is set to 1 (step S2). Here, for example, it is assumed that the first shot area is set on the −Y side in FIG. 2A, and the measurement order N = 1 is set for the EGA shot ES1 closest to the wafer alignment sensor 17.

Next, in this example, five EGA shots are used in determining the measurement path, so the EGs whose order is not determined
It is determined whether there are four or more A shots (five including the EGA shot in which the measurement order is set) (step S3). If this is the case, five shots of the EGA shot ES1
The EGA shots including the shot ES1 whose order is not determined are selected (step S4). Here, as is clear from FIG. 2A, EGA shots ES1 to ES5 are selected. Note that the number of shots to be selected in an undetermined order is not limited to four shots, and at least two shots may be used.

Next, the first EGA shot ES1 in the order
, The total length of the route that passes through the selected EGA shots ES2 to ES5 is calculated for all 24 patterns (step S5). Then, a measurement order N = 1 + 1 = 2 is set as a shot to be measured immediately after the EGA shot ES1 with respect to the second EGA shot (ES2) of the route having the shortest overall length among the calculated routes ( Step S6). Thereafter, it is determined whether the measurement order has been set for all EGA shots by comparing whether the measurement order N has reached 6 (step S).
7) If there is an EGA shot whose order is not determined, the process returns to step S3. If there are four or more EGA shots for which the order has not been determined, steps S3 to S6 are repeated while replacing the EGA shot for which the measurement order has been determined.

In this case, since the EGA shots whose order has not been determined are four ES3 to ES6, the process proceeds to step S4, where the EGA shots whose measurement order has been determined are shot ES
After replacing the shot ES2 with the shot ES2, the EGA shot ES2 and the four EGA shots whose order is not determined, that is, shots ES3 to ES6 are selected in the order close to the shot ES2. Then, in step S5, EGA shot E
Four EGA shots ES3 to ES6 starting from S2
Are calculated, and in step S6, the measurement order N is set to N = 2 + 1 = 3 for the second EGA shot (ES3) of the path having the shortest overall length. As a result, the EGA shot whose order is not determined is ES4
To ES6, so in this example, step S
The process proceeds to step S8 via 7, S3.

On the other hand, if there are less than four EGA shots whose order is not determined in step S3, the Nth EG
Five shots close to the A shot are selected from the remaining EGA shots including the Nth EGA shot and the search shots (step S8). For example, the measurement order N = 3
After the EGA shot ES3 is set, the number of EGA shots whose order is undetermined is ES4 to ES6. Therefore, in the search shots SS1 and SS2, E
Search shots SS2 and ES close to GA shot ES3
Select 5 shots from 3 to ES6. When the measurement order is determined and the number of shots including the search shot is less than five, all the Es whose order is undetermined including the search shot are included.
Select GA shot.

Next, with the N-th EGA shot ES3 as the starting point and the search shot SS2 as the ending point, the selected E
GA shot ES4 to ES6 and search shot SS
The total length of the route passing through No. 2 is calculated for all the routes (step S9). Then, in step S6, the EGA shot ES with respect to the second EGA shot (hereinafter referred to as ES4) of the route having the shortest overall length among the calculated routes.
Measurement order N = 3 + 1 as a shot to be measured immediately after 3
= 4 is set. Thereafter, steps S8, S9, S6
Are repeatedly executed to set measurement orders N = 1 to 6 for all EGA shots ES1 to ES6 (assuming that ES5 is set for measurement order N = 5 and ES6 is set for N = 6).

Then, N = 6th EGA shot ES
6 (starting point 6), all the paths (two patterns) passing through the search shots SS1 and SS2 are calculated (step S10), and the second search shot SS1 of the path having the shortest overall length is measured in the measurement order N = N + 1 = 7, third Search Shot SS2
Are set to the measurement order N = N + 2 = 8 (step S1).
1). Thereafter, the measurement order N = 1 to 8 obtained is set in reverse (step S12).

Thus, the measurement order is as follows: search shot SS2 → SS1 → EGA shot ES6 → ES5 → ES
The sequence is set to 4 → ES3 → ES2 → ES1, and the sequence for determining the measurement order ends, and the main control system 15 stores the determined measurement order. Each shot SS1, SS2, E
Y search mark YSM, X search mark XSM or Y mark YEM, X mark XEM in S1 to ES6
Is set so as to follow the shortest path in shot units (processing point units) separately from the EGA shot measurement order. Therefore, between the EGA shots, the X mark XEM
And the order of measurement of the Y mark YEM may be reversed.

When the wafer W for which the pre-process has been completed is loaded on the wafer stage 10 in a pre-aligned state, alignment is performed in accordance with the determined measurement order (step S13). Specifically, the stage control system 14 drives the wafer stage 10 via the driving device 11 to first move the Y search mark YSM of the first search shot SS2 in the measurement order to the detection position of the wafer alignment sensor 17. Let it. The position of the wafer W is determined by the laser interferometer 13 via the wafer stage 10.
Is monitored with high precision by the stage control system 1
4 can position the wafer W with high accuracy based on the monitoring result.

When the Y search mark YSM is set at the detection position, the focus of the wafer W is adjusted using the wafer alignment sensor 17, and then the Y search mark YSM is adjusted.
Measure the position of the SM. Similarly, the wafer W is moved to X
The position of the search mark XSM is measured. Thereafter, the positions of the Y search mark YSM and the X search mark XSM of the search shot SS1 are sequentially measured with the movement of the wafer W. Then, the positions of the Y mark YEM and the X mark XEM of the EGA shots ES1 to ES6 set on the wafer W are corrected based on the obtained measurement results.

That is, the main control system 15 determines the EGA based on the coordinate values of the measured X search mark XSM and Y search mark YSM on the wafer stage moving coordinate system XY and the corresponding design coordinate values. For each shot, the design coordinate values of the X mark XEM and the Y mark YEM on the wafer stage movement coordinate system XY are corrected, and the stage control system 14 uses the corrected coordinate values as target values and sets the laser interferometer 13 Then, the wafer stage 10 is moved on the basis of the measured values, and the X mark XEM and the Y mark YEM are respectively positioned within the detection area of the wafer alignment sensor 17 for each EGA shot. In this example, correcting design coordinate values of the X mark XEM and the Y mark YEM based on position information obtained by detecting a search mark for each search shot is called search alignment.

In this example, the one-dimensional X search mark X
Although the SM and the Y search mark YSM are used, a two-dimensional XY search mark may be used as a search alignment mark. In this case, it is not necessary to move the wafer W by one search shot, and the position information in the X and Y directions can be simultaneously detected at the same stage position, thereby shortening the alignment time, that is, improving the throughput. Becomes possible.

The one-dimensional search marks XSM, YS
Even when M is used, it is not necessary to detect both the X search mark XSM and the Y search mark YSM in each search shot, and the X search mark XSM is used to shorten the alignment time (improve the throughput). , And one of the Y search marks YSM are detected by only one of the two search shots. That is, only one of the X search mark XSM and the Y search mark YSM may be detected in one search shot. . It should be noted that which of the X search mark XSM and the Y search mark YSM is used as the search mark to be detected by only one search shot may be determined according to the arrangement of the two search shots on the wafer W. In each search shot, X search mark XSM and Y search mark YSM
May be detected, but three search shots are required.

Further, the number of search shots is not limited to two, but may be one or three or more.
The number of search shots (search marks) may be determined according to the number of pieces of position information (coordinate values) in the direction. The number of pieces of position information to be detected is determined according to, for example, the pre-alignment accuracy of the loaded wafer W.

When the search alignment is completed, the EGA
Perform measurement. That is, the wafer alignment sensor 1
7, the Y mark YE of the EGA shot ES6
Move M. At this time, the position information of the Y mark YEM and the X mark XEM has been corrected by the search alignment described above, so that the Y mark YEM can be placed on the wafer without any trouble.
It can move to a position where the alignment sensor 17 can detect.
After the focus is adjusted by the wafer alignment sensor 17, the position of the Y mark YEM is measured. Next, the position of the X mark XEM is measured by moving the wafer W. Thereafter, the wafer W is processed in the same procedure as described above.
, The positions of the Y marks YEM and X marks XEM of the EGA shots ES5 to ES1 are sequentially measured in accordance with the previously determined measurement order.

Y in EGA shots ES1 to ES6
When the position measurement of the mark YEM and the X mark YEM is completed, a statistical operation such as a least-squares method is performed based on the obtained measured value and the design value to obtain X Shift, Y shift,
Six error parameters of X scale, Y scale, rotation, and orthogonality are calculated. Then, based on these error parameters, the design coordinate position is corrected for all shot areas on the wafer W.

It should be noted that, instead of calculating the above-mentioned six error parameters, for example, as disclosed in Japanese Patent Laid-Open Publication No. Sho 61-44429, the arrangement characteristics of the shot area including these six error parameters are disclosed. The coefficient (element) of a model function (for example, determinant) representing
Substituting the design coordinate values into the model function for which this coefficient has been calculated for each shot area, the wafer stage movement coordinate system X
The coordinate value on Y may be calculated. When it is necessary to obtain at least one of the above-described six error parameters, the at least one error parameter may be obtained using the previously calculated coefficients.

Subsequently, in accordance with at least one of the six calculated error parameters, the distance between the lens groups constituting the projection optical system 9 is controlled, or the pressure in the projection optical system 9 is controlled by controlling the air pressure in the lens chamber. The imaging characteristics (projection magnification, distortion, etc.) are adjusted, and the corrected (calculated) coordinate position and the baseline amount, which is the distance between the projection optical system 9 and the wafer alignment sensor 17, are used. Then, the wafer stage 10 is sequentially moved stepwise, and the pattern on the reticle R is sequentially exposed to each shot area on the wafer W by a step-and-repeat method.

In the position measurement method and the exposure method of the present embodiment, at the time of EGA measurement, the Y mark YEM and the X mark XEM in the EGA shot ES6 closest to the search shot SS1 are measured first, and the first exposure processing is performed. Y in EGA shot ES1 closest to one shot area
Since the measurement order is set so that the mark YEM and the X mark XEM are measured last, the wafer stage 1 when shifting from search alignment to fine alignment and when shifting from fine alignment to exposure processing
0 can be minimized. Therefore, the position measurement time of the wafer W including the movement time of the wafer stage 10 can be shortened, and the throughput can be improved. In particular, in the present embodiment, when the first shot area is located at the exposure position (or its preparation position), the Y mark and the X mark in the EGA shot closest to the detection position of the wafer alignment sensor 17 are placed last. By setting the measurement order, the transition time from fine alignment to exposure processing is shortened.

In the present embodiment, the projection exposure apparatus shown in FIG.
A scanning method, that is, a scanning exposure type may be used. In this case, when the first shot area on the wafer W to be exposed first is located at the exposure preparation position, the fine alignment X mark and Y mark in the EGA shot closest to the detection position of the wafer alignment sensor 17 are set. The mark will be set in the order in which the marks are measured last. Here, in the scanning exposure apparatus, the reticle R
And the wafer W are moved relative to each other, and the wafer W (shot area) is irradiated with illumination light via the reticle R and the projection optical system 9.
Is exposed by scanning. At this time, the scanning exposure is started after the reticle R and the wafer W each reach a predetermined scanning speed and the alignment error between the reticle R and the wafer W becomes equal to or less than a predetermined allowable value. period)
Need to be set. Therefore, in the scanning exposure apparatus, when the first shot area is arranged at the exposure preparation position, not the exposure position, that is, the approach start position (acceleration start position), the EG closest to the detection position of the wafer alignment sensor 17 is set.
The A shot is set at the end of the measurement order.

In the position measurement method and the exposure method according to the present embodiment, when determining a path for performing EGA measurement,
By selecting shots and finding the shortest path starting from the EGA shot in which the measurement order is determined, the EGA shot to be measured immediately after the EGA shot in which the order is determined is determined, and the distance from the EGA shot as the start point is short. Since five shots are selected in order, the intermediate path between the beginning and end of the measurement order is also minimized. Therefore, the position measurement time of the wafer W including the movement time of the wafer stage 10 can be minimized, and the throughput can be greatly improved. Further, in the present embodiment, the determination processing of the measurement order is executed not immediately before the exposure processing but at the time when the input and editing of the parameters necessary for the determination of the order are completed, so that the exposure processing can be started quickly. And further improvement in throughput is realized.

The present invention is not limited to the above embodiment, but can be applied to the following embodiments. (1) Two or more sets of Y marks and X marks are provided as second marks for EGA measurement in each shot area, or two-dimensional X for measuring positional information in the X direction and the Y direction.
Two or more Y marks can be provided as second marks (so-called multipoint measurement within a shot). In this case, the position information of each shot area can be obtained by measuring these marks. Specifically, 3 for each EGA shot
By detecting more than a set of X marks and Y marks (three or more XY marks in the case of a two-dimensional mark) and obtaining their position information, the X scale, Y scale, rotation, and orthogonality of each shot area are obtained. Can be calculated, and 10 error parameters can be obtained in addition to the 6 error parameters (related to the wafer) relating to the arrangement characteristics of the shot areas, and the superposition of the shot areas can be further improved. It can be performed with high accuracy. It is not necessary to calculate all four error parameters of the shot area, and the number of error parameters may be any one to three. For example, by detecting two sets of X marks and Y marks (two XY marks in the case of a two-dimensional mark) in each EGA shot and obtaining the position information, the X scale, Y scale, and rotation of the shot area are obtained. May be calculated. The X scale and the Y scale are magnification errors of the shot area in the X direction and the Y direction, respectively.

(2) A plurality of measurement points (alignment marks) are included in an EGA shot, such as detecting a one-dimensional X mark and a Y mark in each EGA shot or detecting two or more two-dimensional XY marks. In some cases, as in the above embodiment, after setting the shortest path for each EGA shot, the measurement order of the Y mark and the X mark or the plurality of XY marks is determined so as to follow the shortest path in each EGA shot. Alternatively, for example, in the state where the framework of the shot is removed, as in the above-described embodiment, after determining the marks to be measured first and last, the intermediate path for all the marks is minimized. The measurement order may be determined on a mark-by-mark basis. in this case,
The time required for mark measurement can be strictly minimized, and the throughput can be further improved.

(3) In the above embodiment, since the EGA shot is not included in the first shot area to be exposed first and the search shot, the EGA shot closest to the search shot
The GA shot (Y mark, X mark) is set at the beginning of the measurement order, and the EGA shot (Y mark, X mark) closest to the first shot area is set at the end of the measurement order. If the EGA shot is included in the EGA shot, the EGA shot is set at the beginning of the EGA measurement, and if the first shot area is included in the EGA shot, the EGA shot is set at the end of the measurement order. Good. Thereby, particularly when shifting from the search alignment to the fine alignment, the mark measurement is performed in the same shot area, so that the movement time of the wafer W can be further reduced.

(4) Although both the search mark and the alignment mark for EGA measurement are detected by the wafer alignment sensor 17, the sensor for search mark detection and the sensor for fine alignment mark detection are individually separated from each other. When the search mark of the search shot is positioned at the detection position (first detection position) of the search mark detection sensor, the detection position of the alignment mark detection sensor (second detection position) or the nearest position is set. E first measures the alignment mark placed on
It may be set as a GA shot mark. This allows
Even when different sensors are arranged, the measurement order can be set so that the time required for the measurement time is minimized according to the position of the sensor, which contributes to an improvement in throughput. In addition, these sensors are not limited to the FIA method that measures the position of a mark by image processing, and may use a laser step alignment method (LSA method), an LIA method, or the like as appropriate by using a grating mark or a diffraction grating mark as a mark. Can be adopted. Note that both the search mark detection sensor and the fine mark detection sensor are not limited to the off-axis type, and a TT using a single-wavelength laser beam, multi-wavelength light, broadband light, or exposure light is used.
An L system, a TTR system, or the like can be appropriately employed.

(5) Further, the focus is adjusted by the wafer alignment sensor 17, but when the wafer alignment sensor 17 does not have the AF function, it is not shown in FIG. The main AF mechanism used to match the wafer (shot area) to the image forming plane may be used instead.
In this case, the search alignment may be performed by adjusting the focus of the search shot by the main AF mechanism, and then moving the search mark to the mark detection position. However, since the accuracy required for the search alignment is lower than that of the EGA measurement, it is not always necessary. It is not necessary to perform the focus adjustment in the search shot, and the focus adjustment may be performed at an arbitrary position on the wafer W during the movement from the loading position to the mark detection position. The focus adjustment in the EGA measurement by the main AF mechanism may be performed at the center of the wafer W after performing the mark measurement, or may be performed at the focus position set at the time of the search alignment as well as at the EGA shot. Mark measurement may be performed. Further, at the time of EGA measurement,
Focus adjustment may be performed for each shot (AF
→ X mark measurement → Y mark measurement), focus adjustment may be performed for each mark measurement (AF → X mark measurement → A
F → Y mark measurement).

Further, focus adjustment may be performed only for at least one EGA shot, instead of performing focus adjustment for all EGA shots on the wafer. At this time, it is desirable that at least one EGA shot for performing focus adjustment includes an EGA shot from which position information should be detected first. This is particularly effective when focus adjustment is not performed on a search shot. Further, the at least one EGA shot may include, for example, one EGA shot selected for each quadrant of the orthogonal coordinate system having the coordinate origin at the wafer center, for example, or the measurement order is nth, and n + α.
, The (n + 2α) -th EGA shot may be included. Note that n is a natural number and α is a natural number of 2 or more. In addition, when performing focus adjustment on a part of a search shot or an EGA shot, settings such as how to perform the focus adjustment and which shot to perform the focus adjustment can be set in advance as an apparatus constant for each exposure apparatus. For each process program, it is set according to the process layer to be exposed. Further, the height position is detected at each of a plurality of points on the wafer, the average plane of the wafer is calculated, and focus adjustment (including leveling adjustment) is performed so that the average plane matches the focal plane of the wafer alignment sensor 17.
And then search alignment and E
GA measurement may be performed. At this time, the plurality of points at which the height position is detected may be any point on the wafer,
For example, it may be set on a street line that divides a shot area on a wafer. In addition, the AF
Either the mechanism or the main AF mechanism may be used. In addition,
When the main AF mechanism is provided as described above, the measurement order is determined so that the mark measurement time including the moving distance and the moving time of the wafer W from the focus adjustment position to the mark measuring position is minimized.

(6) For example, when the distance between the projection optical system 9 and the wafer alignment sensor 17 is short, the EG closest to the first shot area to be exposed first
A procedure may be adopted in which the EGA measurement is performed last for the A shot.
As described above, the last EGA shot for performing the EGA measurement depends on the distance between the projection optical system 9 and the wafer alignment sensor 17, that is, the wafer amount when the first shot area is at the exposure position according to the baseline amount. -It is preferable to select an object having a short distance from the detection position of the alignment sensor 17 or a short distance from the first shot area.

(7) After determining the alignment marks to be measured first and last, the procedure for determining the intermediate path is, as in the above embodiment, a unit of a plurality of shots (5 shots in the above-described embodiment). In addition to calculating the total lengths of all the paths in (1), the total lengths of all the measurement paths may be calculated in EGA shot units or alignment mark units, and the shortest path may be set as the measurement order.
Further, both the first measurement mode for calculating the entire length of the path in units of 5 shots as in the former and the second measurement mode for calculating the entire length of the measurement path as in the latter are set, and the EGA is set.
One of the first and second measurement modes may be selected according to the number of EGA shots to be measured. As a result, an optimal measurement order can be obtained in the shortest calculation time according to the number of EGA shots. In this case, a table for automatically determining whether to select the first measurement mode or the second measurement mode according to the number of EGA shots is set in the main control system 15, and the number of EGA shots is set as exposure data. The mode selection may be performed at the time of input / edit.

In the first measurement mode, the calculation order may not be calculated at the time of editing the exposure data, but may be calculated immediately before the EGA measurement is performed. This is particularly necessary when the measurement order of search shots is determined from the wafer loading position or the like as in (10) to be described later, or depending on the measurement result of search alignment, it is necessary to repeat search alignment. If you don't know what will be measured last,
More effective. Further, in the first measurement mode, the measurement order of the EGA shots is determined from the end as described in the above-described embodiment. Conversely, the measurement order of the EGA shots may be determined from the beginning. That is,
A search shot to be measured last and a plurality of EGA shots (four in the above embodiment, but at least two) are selected in the order closest to the search shot, and the plurality of EGA shots starting from the search shot are selected. The entire path of the EGA shot is calculated, and the EGA shot measured next to the search shot on the path having the shortest overall length is defined as the EGA shot.
This is set as the first EGA shot to be measured first in the measurement. Next, the first EGA shot and a plurality of EGA shots are selected in the order closest to the first EGA shot, and the first EGA shot is selected.
All the paths of the plurality of EGA shots starting from the shot are calculated, and the EGA shot to be measured second in the path having the shortest overall length is set as the second EGA shot. The measurement order may be determined. At this time, when the first shot area to be exposed first is an EGA shot, the first shot area is used. When the first shot area is not an EGA shot, the EGA shot closest to the first shot area is used. When the last set or the first shot area is arranged at the exposure position or its preparation position, the EGA shot arranged at the detection position of the wafer alignment sensor 17 or the nearest EGA shot is defined as E
It may be set at the end of the GA measurement order.
Alternatively, the measurement order of the search shots may be determined as in (8) described later. Here, EGA
Although the measurement order is determined for each shot, the measurement order may be similarly determined for each fine alignment mark. Further, when fine alignment (EGA measurement) is performed without performing search alignment after loading the wafer W on the wafer stage 10, based on the loading position of the wafer W as described in (8) described later. An EGA shot (first EGA shot) to be measured first may be determined.

(8) The search mark (search shot) to be measured first, and the EGA can be performed without performing the search alignment because the pre-alignment is performed with high precision.
The alignment mark (EGA shot) to be measured first when measuring is performed by using the wafer W on the wafer stage 10.
(Ie, when the wafer stage 10 is at the wafer loading position), the wafer alignment sensor 17 (alignment sensor for search mark detection or fine mark detection) is positioned at or closest to the mark detection position. The mark (shot) to be set can also be set. In this case, the time required from the loading of the wafer W to the mark measurement can be reduced, and the effect of improving the throughput at the start of measurement can be obtained. Similarly,
It is not necessary to consider the optimization of the search alignment path, and when the search alignment is not performed, as described above, only the measurement order of the fine alignment marks (EGA shots) to be measured last by the first shot area or the like. Is determined, and the measurement order from the fine alignment mark (EGA shot) to the fine alignment mark (EGA shot) to be measured first retroactively by the method described in the above embodiment is determined,
Alternatively, a fine alignment mark (EGA shot) to be measured last is determined first from the first shot area or the like, and a fine alignment mark (EG) to be measured first based on the loading position of the wafer W is determined.
A shot) may be determined, and then the measurement order of the fine alignment marks (EGA shots) between these marks may be optimized.

When a search mark (search shot) or an alignment mark (EGA shot) to be measured first is determined as described above, step S in FIG.
In FIG. 8, the search shot is excluded from the selection, and FIG.
In step 4, the EGA shot is excluded from the selection targets until m−N ≦ 4. Also, as described above, the search mark (search shot) to be measured first is determined, and when there are two search shots, the measurement order of the search shots is uniquely determined. S11 will be omitted. However,
When the first search shot to be measured as described above is selected as the second search shot in step S11, the path having the shortest overall length may be selected. Also,
As a result of repeatedly executing steps S4 to S6, as described above, the first EGA shot to be measured is the second or subsequent EGA shot.
In the case of a GA shot, a path having the shortest overall length may be selected.

(9) Further, in the case where the wafer stage 10 is not shown, but has an X stage movable in the X direction and a Y stage movable in the Y direction,
If the stages have different weights, the acceleration and the moving speed during the movement will be different. In other words, even when the wafer W is moved by the same distance, the movement times in the X direction and the Y direction are different from each other. Therefore, when determining the measurement order of the marks, by using such drive characteristics of the wafer stage 10, even when the measurement path is long and the moving distance of the stage is long, the time required for the mark measurement is reduced. It is possible to make it as short as possible.

That is, when the wafer W is moved from the point A to the point B and when the wafer W is moved from the point A to the point C,
For example, even if the distance between ABs is shorter than the distance between ACs, considering the driving characteristics (maximum speed, maximum acceleration, etc.) of the wafer stage 10 in the X and Y directions, the movement time between ACs is shorter than the movement time between ABs. May be shorter. In this case, instead of selecting the route from the point A to the point B as the route having the shortest overall length in the above-described embodiment, selecting the route from the point A to the point C having the shortest travel time. Is desirable. The wafer stage 10 is not limited to a configuration having an X stage and a Y stage.
Any configuration may be used, such as a configuration in which the movable body on which is mounted is two-dimensionally moved.

(10) In the above embodiment, the measurement order of EGA shots (fine alignment marks) is determined, and then the measurement order of search shots (search marks) is determined according to the measurement order. However, when there are two or more search shots (search marks), the wafer stage 10 is moved from the loading position of the wafer W to a wafer alignment sensor for detecting a search mark (in FIG. 1, an alignment sensor also used as a fine alignment mark). The measurement order may be determined such that the search shot (search mark) in which the distance to move to the detection position of 10) is the shortest is measured first. At this time, in consideration of the driving characteristics of the wafer stage 10 described in (9) above, the search shot (search mark) in which the moving time from the loading position to the detection position is the shortest is measured first so as to be measured. The measurement order may be determined.

The substrate of the present embodiment is not limited to a semiconductor wafer W for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin-film magnetic head, a mask or a mask used in an exposure apparatus. Reticle master (synthetic quartz, silicon wafer)
Etc. are applied.

The exposure apparatus 1 exposes the pattern of the reticle R while the reticle R and the wafer W are stationary,
Step and move the wafer W step by step
In addition to a repeat type projection exposure apparatus (stepper), a step-and-scan type scanning type exposure apparatus (scanning stepper; USP5, US Pat. 47
3,410). The present invention is also applicable to a step-and-stitch type exposure apparatus that transfers at least two patterns on a wafer W while partially overlapping each other. This exposure apparatus may be either a static exposure type or a scanning exposure type.

In the above-described embodiment, a rectangular area (partition area) on the wafer W which is partitioned by street lines (scribe lines) and on which the pattern of the reticle R is transferred is called a shot area. In the AND stitch method, position information may be calculated using a large area where at least two patterns are transferred as one shot area, or a small area where at least two patterns are respectively transferred as shot areas. The position information may be calculated. Particularly in the latter case, for example, when two patterns A and B are partially overlapped and transferred onto a wafer, a large number of shot areas on the wafer are grouped, that is, a first group including shot areas to which pattern A is transferred is used. , And a second group of shot areas to which the pattern B is transferred, and the above-described EGA calculation may be performed for each group. Further, one reticle pattern may be superimposed and transferred collectively on a plurality of, for example, two or four shot areas on a wafer. In this case, the plurality of shot areas are regarded as one. Alternatively, the position information may be calculated by the above-described EGA calculation. Further, in the above-described embodiment, the reference point defined in the shot area (partition area) on the wafer, for example, the center corresponds to the processing point in the present invention, and the processing point (reference point) is defined by the fine alignment mark. The coordinate value is uniquely set. Further, the position measurement method according to the present invention can be applied to an apparatus for inspecting a circuit pattern formed on a wafer, and the processing point in the present invention is a concept including an inspection point (measurement point) on a wafer. It is. The present invention can be applied not only to an exposure apparatus and an inspection apparatus but also to, for example, a laser repair apparatus for cutting a part (fuse) of a circuit pattern formed on a wafer. Applicable to various devices.

The type of the exposure apparatus 1 is not limited to an exposure apparatus for manufacturing a semiconductor element for exposing a semiconductor element pattern onto a wafer W, but may be an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an imaging apparatus, or the like. Element (CC
D) or an exposure apparatus for manufacturing a reticle or a mask.

As the light source 2, bright lines (g-line (436 nm), h-line (404.
nm), i-line (365 nm)), KrF excimer laser (248 nm), ArF excimer laser (193n)
m), F ₂ laser (157 nm), Ar ₂ laser (126
nm) as well as charged particle beams such as electron beams and ion beams. For example, when an electron beam is used, a thermionic emission type lanthanum hexaborite (LaB ₆ ) or tantalum (Ta) can be used as an electron gun. Further, a harmonic such as a YAG laser or a semiconductor laser may be used. For example, a single-wavelength laser in the infrared or visible region oscillated from a DFB semiconductor laser or a fiber laser is amplified by, for example, a fiber amplifier doped with erbium (or both erbium and yttrium), and a nonlinear optical crystal is used. Alternatively, a harmonic converted to ultraviolet light may be used as exposure light. The oscillation wavelength of the single-wavelength laser is 1.544 to 1.553 μm.
, The eighth harmonic within the range of 193 to 194 nm, that is, ultraviolet light having substantially the same wavelength as the ArF excimer laser is obtained, and the oscillation wavelength is set to 1.57 to 1.58 μm.
Within the range of 157 to 158 nm.
The second harmonic, that is, ultraviolet light having substantially the same wavelength as the F2 laser is obtained.

A soft X-ray region having a wavelength of about 5 to 50 nm generated from a laser plasma light source or SOR, for example, an EUV (Extreme) having a wavelength of 13.4 nm or 11.5 nm.
Ultra Violet) light may be used as the exposure light.
In the exposure apparatus, a reflection type reticle is used, and the projection optical system is a reduction system including only a plurality of (for example, about 3 to 6) reflection optical elements (mirrors). Furthermore, hard X
A line (for example, a wavelength of about 1 nm or less) may be used as the exposure light, and this exposure apparatus employs a proximity method.

The projection optical system 9 may be not only a reduction system but also an equal magnification system or an enlargement system. Further, the projection optical system 9 may be any one of a refraction system, a reflection system, and a catadioptric system. When the wavelength of the exposure light is about 200 nm or less, it is desirable to purge the optical path through which the exposure light passes with a gas that absorbs less exposure light (an inert gas such as nitrogen or helium). When an electron beam is used, an electron optical system including an electron lens and a deflector may be used as the optical system. It is needless to say that the optical path through which the electron beam passes is in a vacuum state. Further, the present invention can also be applied to a proximity exposure apparatus that exposes the pattern of the reticle R by bringing the reticle R and the wafer W close to each other without using the projection optical system 9.

The wafer stage 10 and the reticle stage 2
When a linear motor (see US Pat. No. 5,623,853 or US Pat. No. 5,528,118) is used for the motor 0, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. In addition, each stage 1
0, 20 may be of the type that moves along the guide,
A guideless type without a guide may be used.

As a driving mechanism of each stage 10, 20, a magnet unit having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil are opposed to each other, and each stage 10, 20 is driven by an electromagnetic force. A planar motor may be used. In this case, one of the magnet unit and the armature unit is connected to the stages 10 and 20, and the other of the magnet unit and the armature unit is connected to the stages 10 and 20.
May be provided on the moving surface side.

The reaction force generated by the movement of the wafer stage 10 is not transmitted to the projection optical system 9 so that the
As described in 166475 (US Pat. No. 5,528,118), a frame member may be used to mechanically escape to the floor (ground). As described in JP-A-8-330224 (US S / N 08 / 416,558), a frame member is used so that the reaction force generated by the movement of the reticle stage 20 is not transmitted to the projection optical system 9. May be mechanically released to the floor (ground).

As described above, the exposure apparatus 1 of the present embodiment
Is a system that includes various components including the components listed in the claims of the present application, with predetermined mechanical accuracy, electrical accuracy,
It is manufactured by assembling to maintain optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the manufacture of the exposure apparatus be performed in a clean room in which the temperature, cleanliness, and the like are controlled.

As shown in FIG. 4, for a semiconductor device, a step 201 for designing the function and performance of the device, a step 202 for manufacturing a mask (reticle) based on the design step, a step 203 for manufacturing a wafer from a silicon material A wafer processing step 204 of exposing a reticle pattern to a wafer by the exposure apparatus 1 of the above-described embodiment, a device assembling step (a dicing step,
(Including a bonding step and a package step) 205, an inspection step 206, and the like.

[0083]

As described above, in the position measuring method according to the first aspect, the second mark closest to the processing point to be processed first is set at the end of the measurement order, and the second mark closest to the first mark is set. The procedure is to set the mark at the beginning of the measurement order. As a result, in this position measurement method, the time required to shift from search alignment to fine alignment and the time required to shift from fine alignment to processing can be reduced, and the effect of improving throughput and productivity can be obtained.

The position measuring method according to claim 2 is a procedure for calculating position information of each processing point based on position information obtained by detecting a second mark provided at least at each of a plurality of processing points. ing. As a result, in this position measurement method, it is possible to reduce the time required to calculate the arrangement characteristics of the processing points by performing so-called EGA measurement, and to obtain the effect of improving the throughput.

The position measuring method according to the third aspect is a procedure for measuring position information of a plurality of second marks at at least three processing points. Thus, in this position measurement method, by performing so-called multi-point measurement within a shot, there is an effect that more accurate position information regarding each processing point and the arrangement characteristics of the processing points can be obtained.

In the position measuring method according to the fourth aspect, the second mark includes at least one one-dimensional X mark and one Y mark. Accordingly, in this position measurement method, by performing multi-point measurement within a shot using a one-dimensional mark, there is an effect that more accurate position information regarding each processing point and the arrangement characteristics of the processing points can be obtained.

According to a fifth aspect of the present invention, the second mark includes at least one two-dimensional XY mark. Accordingly, in this position measurement method, by performing multi-point measurement within a shot using a two-dimensional mark, there is an effect that more accurate position information regarding each processing point and the arrangement characteristics of the processing points can be obtained.

The position measuring method according to claim 6 is configured such that the second mark to be measured last is provided corresponding to the processing point to be processed first or the processing point closest to the processing point to be processed first. . As a result, in this position measurement method, regardless of whether the processing point to be processed first includes the second mark, the effect of improving the throughput by shortening the transition time from fine alignment to processing is obtained. Can be

According to a seventh aspect of the present invention, there is provided a position measuring method, in which the measuring path between the second mark to be measured first and the second mark to be measured last is the shortest. The procedure is to determine the measurement order. As a result, in this position measurement method, the intermediate path between the beginning and the end of the measurement order is also shortest in the processing point unit or the second mark unit, so that the position measurement time is the shortest, and the throughput is greatly improved. The effect that can be obtained is obtained.

In the position measuring method according to the eighth aspect, the measuring order is determined for each processing point, and when a plurality of second marks corresponding to each processing point are provided, a plurality of second marks are provided for each processing point. 2
This is a procedure for setting the measurement order of marks. As a result, in this position measurement method, even when the measurement order is determined for each processing point, the time required for the measurement of the second mark can be reduced, and the effect of improving the throughput can be obtained.

In the position measuring method according to the ninth aspect, when the detection positions of the first mark and the second mark are different, when the first mark is at the detection position, the detection position of the second mark or the nearest position is detected. Is a procedure for setting the second mark arranged at the beginning of the measurement order. As a result, in this position measurement method, even when the detection positions are different, there is an effect that the throughput is improved by shortening the transition time from the search alignment to the fine alignment.

According to a tenth aspect of the present invention, when the processing point to be processed first is arranged at the processing position or its preparation position, the second mark arranged at the detection position of the second mark or the nearest position is determined. The procedure is to set at the end of the measurement order. As a result, in this position measurement method, the time required to shift from fine alignment to processing can be reduced, and the effect of improving throughput can be obtained.

According to the position measuring method of the present invention, at least three second marks including the second mark to be measured last are selected, and all the measurement paths having the second mark to be measured last as the end point are obtained. The step of determining the second mark to be measured immediately before the second mark to be measured last in the measurement path is repeatedly executed while replacing the second mark to set the measurement order. As a result, in this position measurement method, the intermediate path between the beginning and end of the measurement order can be shortened, so that the effect of greatly improving the throughput can be obtained.

The position measuring method according to the twelfth aspect has a procedure of selecting at least two second marks in order of decreasing distance from the second mark to be measured last. As a result, in this position measurement method, the intermediate path can be minimized, and the throughput can be greatly improved.

In the position measuring method according to the thirteenth aspect, all measurement paths having the second mark to be measured first as a start point and the second mark to be measured last as an end point are obtained, and the shortest measurement path is determined as a measurement order. It is a procedure to set. As a result, in this position measurement method, the shortest intermediate path can be selected, and the effect of greatly improving the throughput can be obtained.

According to a fourteenth aspect of the present invention, when the processing point to be processed is first placed at the processing position or its preparation position, the mark located at the detected position of the mark or the mark located closest thereto is placed at the end of the measurement order. This is the procedure to set. As a result, in this position measurement method, the time required to shift from mark measurement to processing can be reduced, and the effect of improving throughput can be obtained.

The position measuring method according to claim 15 is a procedure for calculating the position information of each processing point based on the position information obtained by detecting the marks provided on at least three of the plurality of processing points. . As a result, in this position measurement method, it is possible to reduce the time required to calculate the arrangement characteristics of the processing points by performing so-called EGA measurement, and to obtain the effect of improving the throughput.

The position measuring method according to claim 16 is a procedure for measuring position information of a plurality of marks at at least three processing points. Thus, in this position measurement method, by performing so-called multi-point measurement within a shot, there is an effect that more accurate position information regarding each processing point and the arrangement characteristics of the processing points can be obtained.

The position measuring method according to the seventeenth aspect is a procedure for setting a mark detection position or a mark arranged closest thereto when a substrate is placed on a stage, first in a measurement order. As a result, in this position measuring method, the time required from the loading of the substrate to the mark measurement can be reduced, and the effect of improving the throughput can be obtained.

In the position measuring method according to the eighteenth aspect, the measuring order is determined for each processing point or each mark such that the measuring path between the first measured mark and the last measured mark is the shortest. It is a procedure. This allows
In this position measurement method, the intermediate path between the beginning and the end of the measurement order is also made the shortest in the processing point unit or the mark unit, so that the position measurement time becomes the shortest and the effect that the throughput can be greatly improved is obtained. Can be

A position measuring method according to a nineteenth aspect is a method of obtaining all measurement paths starting from a mark to be measured first and an end to a mark to be measured last, and setting the shortest measurement path as a measurement order. Has become. This allows
In this position measurement method, the shortest intermediate path can be selected, and the effect that the throughput can be greatly improved can be obtained.

According to a twentieth aspect of the present invention, in the position measuring method, at least three marks including the mark to be measured last are selected, all the measurement paths ending with the mark to be measured last are determined, and the last measurement path is selected. The step of determining the mark to be measured immediately before the mark to be measured is repeatedly executed while replacing the mark to set the measurement order. This allows the position measurement method to minimize the intermediate path between the beginning and end of the measurement order,
The effect that the throughput can be greatly improved is obtained.

The position measuring method according to claim 21 is a procedure for selecting one of the first measuring mode and the second measuring mode according to the number of second marks for measuring position information.
Thus, this position measurement method has an effect that an optimum measurement order can be obtained in the shortest calculation time according to the number of second marks.

The position measuring method according to the twenty-second aspect is a procedure for determining the measuring order using the driving characteristics of the stage for moving the substrate. As a result, this position measurement method has an effect that the measurement order in the shortest time can be determined even when the moving distance is long depending on the driving characteristics.

The position measuring method according to the twenty-third aspect is configured such that a processing point is set in a divided area to be exposed. Accordingly, in this position measurement method, when the position information of a plurality of divided areas is measured in the exposure processing,
The time required for the measurement can be reduced, and the effect of improving the throughput can be obtained.

The exposure method according to a twenty-fourth aspect is a procedure in which, when exposing each of the divided areas of the substrate, the position information of each of the divided areas is measured using the position measuring method according to the twenty-third aspect. . Thus, in this exposure method, the exposure processing can be started quickly, and the effect of further improving the throughput is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an exposure apparatus showing an embodiment of the present invention.

FIG. 2A is a plan view of a wafer on which a plurality of EGA shots and search shots are set, and FIG. 2B is an enlarged view of each shot area.

FIG. 3 is a view showing an embodiment of the present invention, and is a flowchart for determining a mark measurement order.

FIG. 4 is a flowchart illustrating an example of a semiconductor device manufacturing process.

[Explanation of symbols]

 PA pattern area (processing point) R reticle (mask) XSM X search mark (first mark) YSM Y search mark (first mark) XEM X mark (alignment mark, second mark) YEM Y mark (alignment mark, second mark) Mark) W Wafer (substrate) 10 Wafer stage (stage)

Claims (24)

[Claims] After detecting a first mark for search alignment formed on a substrate, a plurality of processing marks formed on the substrate are calculated in order to calculate position information on a plurality of processing points on the substrate. In a position measuring method for measuring position information of a second mark for fine alignment, a second mark closest to a processing point to be processed first among the plurality of processing points is set at the end of a measurement order of the position information. And a second mark closest to the first mark is set at the beginning of the measurement order of the position information. 2. The second mark is provided in correspondence with each of the plurality of processing points, and based on position information obtained by detecting the second marks provided in at least three of the plurality of processing points. The position measuring method according to claim 1, wherein position information of each of the processing points is calculated. 3. The method according to claim 2, wherein a plurality of the second marks are provided corresponding to the respective processing points, and each position information of the plurality of second marks is measured at each of the at least three processing points. The position measurement method according to claim 2. 4. A one-dimensional X used for measuring position information in orthogonal first and second directions.
4. The position measuring method according to claim 3, wherein at least one mark and one Y mark are included. 5. The two-dimensional X mark used for measuring position information in orthogonal first and second directions.
The position measuring method according to claim 3, wherein at least one Y mark is included. 6. The second mark to be measured last is provided corresponding to the first processing point when the at least three processing points include the first processing point, and the at least three second points are provided. When the processing point does not include the processing point to be processed first, the processing point is provided corresponding to the processing point closest to the processing point to be processed first among the at least three processing points. 6. The position measuring method according to any one of 5. 7. The measurement order of the plurality of second marks for measuring the position information is such that the measurement path between the first measured second mark and the last measured second mark is the shortest. The position measurement method according to claim 2, wherein the position is determined in units of the processing points or the units of the second marks. 8. The processing order is determined for each processing point, and when a plurality of the second marks are provided corresponding to the processing points, the processing is performed separately from the processing order of the processing points. The position measuring method according to claim 7, wherein a measuring order of the plurality of second marks is set for each point. 9. When the first detected position of the first mark is different from the second detected position of the plurality of second marks, the first mark of the plurality of second marks for measuring the position information is provided.
When the mark is placed at the first detection position, the second
The position measurement method according to any one of claims 1 to 8, wherein a detection position or a second mark disposed closest to the detection position is set first in the measurement order of the position information. 10. A plurality of second sensors for measuring the position information
Of the marks, when the first processing point to be processed is located at the processing position or its preparation position, the second mark that is located at the detection position of the second mark or the nearest position thereof is located at the end of the measurement order of the position information. The position measurement method according to any one of claims 1 to 9, wherein 11. A plurality of second sensors for measuring the position information
Among the marks, at least three second marks including the last measured second mark are selected, and all measurement paths of the at least three second marks having the last measured second mark as an end point are obtained. Determining the second mark for measuring the position information immediately before the second mark to be measured last in the shortest measurement path of all the measurement paths; and determining the second mark to be measured last. The position measurement method according to any one of claims 1 to 10, wherein the measurement order is set by repeatedly executing the measurement order while replacing the second mark. 12. The position measuring method according to claim 11, wherein at least two second marks are selected in ascending order of a distance from the second mark to be measured last. 13. All measurement paths of the plurality of second marks having the second mark to be measured first as a start point and the second mark to be measured last as an end point are obtained, and among all the measurement paths, The position measurement method according to claim 1, wherein a shortest measurement path is set as the measurement order. 14. A position measuring method for measuring position information of a plurality of marks formed on the substrate in order to calculate position information on a plurality of processing points on the substrate, respectively. When the processing point to be processed first among the plurality of processing points is arranged at the processing position or its preparation position, the mark detected position or the mark arranged closest thereto is set at the end of the measurement order of the position information. A position measuring method characterized in that: 15. The processing device according to claim 1, wherein the marks are provided corresponding to the plurality of processing points, respectively, and the processing is performed based on position information obtained by detecting marks provided in at least three of the plurality of processing points. The position measurement method according to claim 14, wherein position information of the point is calculated. 16. The apparatus according to claim 15, wherein a plurality of said marks are provided corresponding to said respective processing points, and position information of said plurality of marks is measured at each of said at least three processing points. Position measurement method described in. 17. A plurality of marks for measuring the position information, the plurality of marks being arranged at a detection position of the mark or the closest when the substrate is mounted on a stage moving in first and second directions orthogonal to each other. The mark to be set is set at the beginning of the measurement order of the position information.
17. The position measuring method according to any one of 16). 18. The measurement order of the plurality of marks for measuring the position information is such that the processing point unit is such that a measurement path between the first measured mark and the last measured mark is the shortest. The position measurement method according to any one of claims 14 to 17, wherein the position is determined in units of the mark. 19. A measurement path of the plurality of marks having the mark to be measured first as a start point and the mark to be measured last as an end point is obtained, and the shortest measurement path among all the measurement paths is determined. The position measurement method according to claim 17, wherein the measurement order is set. 20. At least three marks including the last measured mark are selected from the plurality of marks for measuring the position information, and the at least three marks having the last measured mark as an end point are measured. Finding all paths, the step of determining a mark for measuring the position information immediately before the last measured mark in the shortest measurement path among all the measurement paths, the last measured mark is determined 2. The measurement order is set by executing repeatedly while replacing the mark.
The position measurement method according to any one of claims 4 to 19. 21. After detecting a first mark for search alignment formed on the substrate, a plurality of marks formed on the substrate are calculated in order to calculate position information on a plurality of processing points on the substrate. In a position measuring method for measuring position information of a second mark for fine alignment, a second mark closest to a processing point to be processed first among the plurality of processing points is set at the end of a measurement order of the position information. A first measurement mode in which a second mark closest to the first mark is set first in the measurement order of the position information, and measurement paths of a plurality of second marks for measuring the position information are all obtained. One of the second measurement modes in which the shortest measurement path among the measurement paths is set as the measurement order of the position information is selected according to the number of a plurality of second marks for measuring the position information. The position measuring method characterized by measuring the position information based on the one measurement mode. 22. The method according to claim 1, wherein the determination of the measurement order uses a drive characteristic of a stage for moving the substrate in first and second directions orthogonal to each other. Position measurement method. 23. The apparatus according to claim 1, wherein the substrate has a plurality of divided areas to be exposed, and the processing point is set in each of the divided areas. Position measurement method. 24. Using the position measurement method according to claim 23, measuring position information of at least three divided areas on the substrate, and transferring a mask pattern to each divided area on the substrate. Using the measured position information to calculate the position information of each partitioned area on the substrate, and relatively moving the mask and the substrate based on the calculated position information, via the mask An exposure method, wherein each of the divided areas is exposed.