JP6926596B2 - Exposure equipment and exposure method - Google Patents

Description

The present invention relates to an exposure apparatus and an exposure method. More specifically, the present invention relates to an exposure apparatus and an exposure method that perform alignment for each shot by a step-and-repeat method.

Conventionally, when the mask pattern formed on the mask is exposed to the work, the exposed area on the work is divided into a plurality of areas, and the work stage on which the work is placed is moved by a predetermined amount while being moved on the work. A method is adopted in which each divided area is exposed in order. This method is generally called sequential exposure or step-and-repeat exposure (hereinafter, referred to as "sequential exposure"). For example, Patent Document 1 discloses a method of sequentially exposing a pattern formed on a mask to a work.

Japanese Patent No. 4561291

By the way, in sequential exposure, the same pattern is divided into a plurality of shots, and the work stage is sequentially moved to expose the work. In such sequential exposure, alignment is performed for each shot (in the case of a wafer, it is called "die-by-die alignment"), and the overlay accuracy is the best. However, in this case, since it is necessary to sequentially search the alignment marks formed corresponding to each shot area on the work for each shot, the mark search takes time and the throughput is lowered. There is.
Therefore, an object of the present invention is to appropriately perform alignment for each shot in sequential exposure without lowering the throughput.

In order to solve the above problems, one aspect of the exposure apparatus according to the present invention is an exposure apparatus that sequentially transfers a pattern formed on a mask to a plurality of shot regions formed on a work piece via a projection optical system. The plurality of shot regions are arranged on the work along a first direction and a second direction different from the first direction, respectively, and are formed on the work. Alignment marks corresponding to the plurality of first shot regions, each of the plurality of shot regions belonging to the first column arranged along the first direction among the plurality of shot regions as the first shot region. a first detector for detecting each said workpiece on formed on the first second shot plurality of shot regions belonging to the second column adjacent to the second direction relative to the column as an area, comprising a second detector for detecting the alignment marks corresponding to the plurality of second shot areas respectively, and a control unit for controlling the transfer of said plurality of shot areas. Prior Symbol controller, for the first shot region and the second shot area belonging to the second one row adjacent in the direction of a detection of the alignment mark by the first detector, the second perform a detection of the alignment mark by the detecting unit at the same time, before SL on the basis of the first detector and the detection result by the second detector, the position of the position information and the second shot area of the first shot area information is calculated and stored, respectively, Subsequently, based on the position information of the calculated first shot regions, the alignment of the first shot area and the mask I line, the first said transfer in processing the first shot area, repeated sequentially one line along the first direction, performing the transfer to all of the first shot area belonging to the first row After that, the mask and the second shot area are aligned based on the position information of all the second shot areas belonging to the second row stored, and the second shot area is aligned. The transfer to all the second shot regions belonging to the row is continuously performed in the first direction in order.

In this way, a plurality of alignment marks corresponding to a plurality of different shot regions are simultaneously detected, and based on the detection results, sequential exposure is performed on the plurality of shot regions. As a result, the mark search time can be shortened as compared with the case where the alignment marks formed corresponding to each shot area are sequentially searched for each shot area. Therefore, the alignment for each shot can be appropriately performed without lowering the throughput.

Further , with respect to the first column and the second column, the first column is exposed while calculating the position information of the shot region based on the result of the simultaneous search of the alignment marks. Then, after the exposure of the first row is completed, the exposure of the second row is performed. At this time, since the position information is calculated and stored for each shot area in the second column at the time of exposure to the first column, shot exposure can be continuously performed using the stored position information. can. Therefore, the throughput can be appropriately improved.

Further, in the above-mentioned exposure apparatus, the control unit may sequentially perform the transfer in the opposite direction in the first direction in each row adjacent to each other in the second direction. In this case, the throughput can be further improved.
Further, in the above-mentioned exposure apparatus, the control unit performs the transfer to all the second shot regions belonging to the second row, and then the second direction with respect to the second row. A column adjacent to the side opposite to the first column in the above may be newly set as the first column. As a result, it is possible to accurately sequentially expose all shot areas on the work without reducing the throughput.

Furthermore, in the above-mentioned exposure apparatus, when the row newly set as the first row by the control unit is the endmost row in the second direction, the alignment mark by the first detection unit is used. It is not necessary to detect the alignment mark by the second detection unit. As a result, even when the number of columns in the shot area is not divisible by the total number of pairs of the first column and the second column, it is possible to appropriately deal with the case.
Further, in the above-mentioned exposure apparatus, the second shot region may be a plurality of shot regions adjacent to each other in the second direction. That is, the second detection unit may detect the alignment marks corresponding to the plurality of shot regions adjacent to each other in the second direction. As a result, alignment marks can be searched for in three or more columns at the same time, and the throughput can be further improved.

Further, in the above exposure apparatus , the first detection unit is arranged on one side in the first direction with respect to the optical axis of the projection optical system, and the second detection unit is the first detection unit. It may be arranged apart from the above-mentioned second direction.
In this way, by configuring the configuration so that a plurality of alignment marks corresponding to a plurality of different shot areas can be detected at the same time, based on the result of simultaneously detecting a plurality of alignment marks corresponding to a plurality of different shot areas. Sequential exposure to these plurality of shot areas can be performed. Therefore, the alignment for each shot can be appropriately performed without lowering the throughput.

Further, one aspect of the exposure method according to the present invention is an exposure method in which a pattern formed on a mask is sequentially transferred to a plurality of shot regions formed on a work via a projection optical system, and the plurality of exposure methods are described above. The shot regions are arranged on the work along a first direction and a second direction different from the first direction, and among the plurality of shot regions formed on the work. A plurality of shot regions belonging to the first row arranged along the first direction of the above are designated as first shot regions, respectively, and the second row is formed on the work with respect to the first row. Each of the plurality of shot areas belonging to the second column adjacent to the second direction is defined as the second shot area, and the first shot area and the second shot area belonging to one row adjacent to the second direction are used. for, performs detection of the corresponding alignment mark at the same time on the basis of the alignment mark of the detection result, the position information of the position information and the second shot area of the first shot area is calculated and stored, respectively, followed by Te, based on the calculated position information of the first shot area, I row aligned with the first shot area and the mask, the transfer of the to the first shot area after the processing performed, was performed in the first transfer step intends repeating lines sequentially one line along the first direction, the transfer to the first of all the first shot area belonging to the column, Based on the position information of all the second shot regions belonging to the second row stored in the first transfer step, the mask and the second shot region are aligned with each other. Includes a second transfer step in which the transfer to all the second shot regions belonging to the second row is performed sequentially in the first direction.

According to the present invention, in sequential exposure, alignment can be performed for each shot without reducing the throughput.

It is a schematic block diagram which shows the exposure apparatus of this embodiment. This is an example of arranging work alignment marks. This is an example of the arrangement of the detection unit. It is a flowchart which shows the exposure processing procedure which a control part executes. It is a figure which shows the simultaneous search of the 1st work mark of the 1st column and 2nd column. It is a figure which shows the simultaneous search of the 2nd work mark of the 1st column and 2nd column. It is a figure which shows the exposure of the 1st shot area. It is a figure which shows the state which the exposure of the 1st column is completed. It is a figure which shows the exposure of the 7th shot area. It is a figure which shows the simultaneous search of the 1st work mark of the 3rd column and 4th column. It is a figure which shows the search of the 1st work mark of the last column. It is a figure which shows the example of the detection part which includes three cameras. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure explaining the operation when three cameras are provided. It is a figure which shows the example of the detection part which includes four cameras.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an exposure apparatus 100 of the present embodiment. The exposure apparatus 100 is an exposure apparatus that divides the work W into a plurality of shot regions and sequentially exposes each shot region.
(Structure of exposure equipment)
The exposure apparatus 100 includes a light irradiation unit 10, a mask stage 20, a projection optical system 30, and a work stage 40. Here, the work W can be, for example, a printed circuit board, a silicon wafer, a glass substrate, or the like. Further, the work W may be, for example, a work on which a chip is mounted.
The light irradiation unit 10 includes a lamp 11 as a light source and a condensing mirror 12 that reflects and condenses the light from the lamp 11 and emits the exposure light L.

The mask stage 20 holds the mask M on which the mask pattern to be exposed (transferred) to the work W is formed so as to maintain a horizontal state. The mask stage 20 is driven by a mask stage control unit (not shown) and can move in the XY directions (XY: directions parallel to the mask stage 20 plane and orthogonal to each other) and perpendicular to the XY plane. It is configured to be rotatable in the θ direction about the axis (Z axis). Further, a mask alignment mark (hereinafter, referred to as “mask mark”) MAM is formed on the mask M.

The projection optical system 30 has a projection lens and a magnification changing mechanism, and projects a mask pattern formed on the mask M onto the work W. Here, the magnification changing mechanism may be capable of changing the same ratio in the vertical and horizontal directions, for example, in the vertical direction and the horizontal direction, and in a specific angle direction.
The work stage 40 places the work W and holds the work W. The work stage 40 is driven by a work stage control unit 63, which will be described later, and can move in the XY directions. Further, a work alignment mark (hereinafter referred to as "work mark") WAM is formed on the work W.

FIG. 2 is an example of the work mark WAM. _{On the work W shown in FIG. 2, a plurality of shot regions A i} are formed, which are arranged at predetermined intervals along the X direction and the Y direction orthogonal to the X direction. Here, the subscript i is a number indicating the order of exposure (shot exposure) of each shot region in the sequential exposure, and in the case of the work W shown in FIG. 2, i = 1 to 30.
For example, the work W is carried into the exposure apparatus 100 in the X direction (from the left side to the right side in FIG. 2), and the exposure apparatus 100 first applies shot exposure to _{the upper right shot region A 1 in FIG.} Will be done. Next, the work W is moved in the Y direction (from the lower side to the upper side in FIG. 2), and shot exposure is applied to _{the shot area A 2.} In this way, the exposure apparatus 100 performs shot exposure on _{all the shot regions A 1 to} A ₆ belonging to the first row while moving the work W in the Y direction.

Then, when the exposure in the first row is completed, the exposure apparatus 100 moves the work W in the X direction (from the left side to the right side in FIG. 2) and performs shot exposure on the _{shot area A 7 belonging to the second row.} After that, the exposure apparatus 100 performs shot exposure on the _{remaining shot areas A 8 to} A ₁₂ belonging to the second row while moving the work W in the Y direction (from the upper side to the lower side in FIG. 2). The exposure apparatus 100 repeats the above processing, and while moving the work W in the XY directions, sequentially exposes _{all the shot regions A i on the work W.} Then, when the shot exposure in the final row is completed, the work W is carried out from the exposure apparatus 100.
In the following description, the X direction is also referred to as the transport direction of the work W, and the Y direction is also referred to as the exposure direction. Here, the Y direction corresponds to the first direction, and the X direction corresponds to the second direction.

In the present embodiment, a case where two work marks WAM are formed in _{each shot area A i will be described.} Here, it is assumed that the two work marks WAM are _{formed at substantially the center position of each shot region A i in} the X direction, separated from each other in the Y direction. In the following description, of the two work mark WAMs, the work mark WAM formed on the downstream side in the exposure direction (upper side in FIG. 2) in the first row is the first work mark WAM, and the work mark WAM is upstream in the exposure direction in the first row. The work mark WAM formed on the side (lower side of FIG. 2) is referred to as a second work mark WAM.

Further, as shown in FIG. 1, the exposure apparatus 100 in the present embodiment includes a plurality of (two in the present embodiment) detection units 51 and 52 for detecting the work mark WAM. The detection units 51 and 52 are provided in the projection optical system 30 and can move in the XY directions together with the projection optical system 30. As shown in FIG. 3, the detection unit 51 includes a camera 51a and a leveler 51b, and the detection unit 52 includes a camera 52a and a leveler 52b. The cameras 51a and 52a can be, for example, CMOS cameras. Further, the levelers 51b and 52b can be, for example, a laser displacement meter.

The camera 51a and the camera 52a are arranged on the front side (upstream side in the exposure direction in the first row) of the exposure apparatus 100 with respect to the optical axis of the projection optical system 30. Further, the position of the camera 51a in the X direction can be matched with the position of the optical axis of the projection optical system 30 in the X direction. Further, the distance between the camera 51a and the camera 52a in the X direction may be variable. In this case, the camera 51a may be fixed and the camera 52a may be variably configured, or both the camera 51a and the camera 52a may be variably configured.

Returning to FIG. 1, the image processing unit 61 processes the images output by the cameras 51a and 52a and detects the position of the work mark WAM. The control unit 62 calculates and calculates the position information of each shot area (for example, the deviation of the mark detection system from the detection reference position) based on the position information of the work mark WAM detected by the image processing unit 61. Stores the position information of the shot area. The work stage control unit 63 moves the work stage 40 to the exposure position of each shot area based on the position information of each shot area calculated and stored by the control unit 62. As a result, the alignment of each shot region and the mask M is performed, and the exposure apparatus 100 performs shot exposure in this state.

In the present embodiment, the distance between the camera 51a and the camera 52a in the X direction is set to the distance between shots in two rows (nth row, n + 1th row) adjacent to each other in the X direction of the work W. In this embodiment, n is an odd number (n = 1,3,5, ...). Then, the camera 51a and the camera 52a simultaneously detect the work marks WAM formed in the two shot regions adjacent to each other in the X direction in the nth column and the n + 1th column. Here, the detection unit 51 corresponds to the first detection unit, and the detection unit 52 corresponds to the second detection unit. Further, the nth column corresponds to the first column, and the n + 1 column corresponds to the second column.

The control unit 62 calculates the position information of the shot area belonging to the nth column and the position information of the shot area belonging to the n + 1 column from the detection results of the cameras 51a and 52a, respectively, and the position of the shot area belonging to the nth column. The exposure of the shot area belonging to the nth column is controlled based on the information. At this time, the control unit 62 stores the position information of the shot area belonging to the n + 1th column. The control unit 62 repeatedly calculates the position information of the shot areas in the nth and n + 1 columns and exposes the shot areas in the nth column, and when the exposure of all the shot areas belonging to the nth column is completed. , Based on the stored position information of the shot area belonging to the n + 1 column, the exposure to all the shot areas belonging to the n + 1 column is continuously performed.
As described above, in the present embodiment, the time required for the mark search of the work mark WAMs formed in all the shot areas is reduced by simultaneously detecting the work mark WAMs in the plurality of shot areas by the plurality of cameras.

Hereinafter, the exposure processing procedure for the work W will be specifically described.
FIG. 4 is a flowchart showing an exposure processing procedure for the work W. Here, as shown in FIGS. 5 to 11, seven shot regions in the X direction and six shot regions in the Y direction are formed on the work W, and the first work as shown in FIG. 2 is formed in each shot region. The case where the mark WAM and the second work mark WAM are formed will be described.

First, in step S1, the exposure apparatus 100 performs an exchange process for exchanging the work W. As a result, the work W before the exposure process is placed and held on the work stage 40. Next, in step S2, the exposure apparatus 100 performs pre-measurement. Here, the pre-measurement includes a reference height measurement, a baseline search, and a work PA (prealignment) mark search.
In the reference height measurement, the exposure apparatus 100 measures the height of the reference plane set in advance by the levelers 51b and 52b, respectively. Here, the reference plane can be, for example, the surface of a gauge block (block gauge) provided on the work stage 40. Further, in the baseline search, the exposure apparatus 100 performs baseline measurement by the cameras 51a and 52a using reference members provided with reference marks in advance. Here, the reference member can be, for example, a reference mark plate provided on the work stage 40. Further, in the PA mark search, the exposure apparatus 100 searches for a plurality of (for example, two) PA marks formed on the work W by, for example, the camera 51a to detect the deviation (center deviation, rotation, etc.) of the work W. taking measurement. This PA mark search result can be used for position correction on the mask M side.

Next, in step S3, the exposure apparatus 100 detects the mask mark MAM. The mask mark MAM can be detected using, for example, a mask microscope provided on the work stage 40.
In step S4, the control unit 62 determines whether or not there is an adjacent n + 1 column with respect to the nth column to be exposed. Here, n = 1 in the initial state. That is, in this step S4, it is determined whether or not the nth column is the last column (the endmost column). Then, when the control unit 62 determines that the n + 1th column exists (the nth column is not the final column), the process proceeds to step S5, and determines that the n + 1th column does not exist (the nth column is the final column). Then, the process proceeds to step S17.

In step S5, the control unit 62 controls the work stage control unit 63 and moves the work stage 40 to a position where the camera 51a can detect the first work mark WAM in _{the i-th shot area A i in the nth row.} do. Here, i = 1 in the initial state. At this time, in the field of view of the camera 52a, the first work mark WAM of the shot region of the n + 1 row adjacent to the _{i-th shot region A i in the X direction is inserted.} Then, it detects the first workpiece mark WAM of the i-th shot area A _i by the camera 51a, the camera 52a, the first work of the n + 1 row of shot regions adjacent in the X direction to the i th shot area A _i Mark WAM is detected.

For example, if it is n = 1, i = 1, as shown in FIG. 5, by a camera 51a and camera 52a, and the first shot area A ₁ of the first row first workpiece mark WAM, second column The first work mark WAM of the twelfth shot area A ₁₂ of the above is detected at the same time. Further, in step S5, the control unit 62, simultaneously with the detection of the first workpiece mark WAM, as well as measuring the height position of the i-th shot area A _i of the n-th column by leveler 51b, i th the leveler 52b The height position of the shot area in the n + 1 column adjacent to the shot area A _{i is measured.} Then, the control unit 62 calculates and stores the thickness of the work W in each shot region based on the measurement result of the height position.

In step S6, the control unit 62 controls the work stage control unit 63, and moves the work stage 40 to a position where the camera 51a can detect the second work mark WAM in the _{i-th shot area A i.} At this time, the second work mark WAM of the shot region of the n + 1 row adjacent to the _{i-th shot region A i} in the X direction is included in the field of view of the camera 52a. Then, detects the second workpiece mark WAM of the i-th shot area A _i of the n-th column by the camera 51a, the camera 52a, the i-th shot area A _i of the n + 1 row of shot regions adjacent in the X direction The second work mark WAM is detected. For example, if it is n = 1, i = 1, as shown in FIG. 6, by the camera 51a and camera 52a, and the first shot area A ₁ of the first row first workpiece mark WAM, second column _{The second work mark WAM of the 12th} shot area A 12 of the above is detected at the same time.

In step S7, the control unit 62 based on the detection result in step S5 and S6, the position information of the i th shot area A _i of the n-th column, the (n + 1) -th column adjacent to the X direction in the i-th shot area A _i The position information of the shot area of is calculated and stored. Then, the control unit 62 controls the work stage control unit 63 and moves the work stage 40 to the exposure position of _{the i-th shot area A i.} At this time, the control unit 62 based on the position information of the i th shot area A _i performs positioning of the i-th shot area A _i and the mask M, also the leveler measurement results of the i-th shot area A _i Adjust the focus to and.
Then, in step S8, the control unit 62 shot-exposes the _{i-th shot region A i.} For example, when i = 1, in this step S8, as shown in FIG. 7, the first shot area A ₁ is shot-exposed. In step S9, the control unit 62 increments the shot exposure number i.

In step S10, the control unit 62 determines whether or not the exposure has been completed for all the shot regions belonging to the nth column. Then, when the control unit 62 determines that the exposure of all the shot areas belonging to the nth column has not been completed, the control unit 62 returns to step S5 and determines that the exposure of all the shot areas belonging to the nth column has been completed. If so, the process proceeds to step S11.
For example, when n = 1, the control unit 62 determines in step S10 whether or not the exposure of _{all the shot areas A 1 to} A _{6 belonging to the first row has been completed.} Then, when the control unit 62 _{determines that the exposure has not been completed up to the shot area A 6} , the process of steps S5 to S10 is repeated. As a result, the shot exposure in the first row is performed in the direction indicated by the arrow in FIG. 7, and as shown in FIG. 8, all the shot regions A _{1 to} A ₆ belonging to the first row are exposed.

In step S11, the control unit 62 controls the work stage control unit 63 and moves the work stage 40 to the exposure position of _{the i-th shot area A i.} The i-th shot area A _i is a shot area belonging to the n + 1th column. _{The control unit 62 aligns the i-th shot area A i} with the mask M based on the position information of the shot area in the n + 1 column stored in step S7, and the i-th shot stored in step S5. Focus adjustment is performed based on the leveler measurement result of region A _i. Next, in step S12, the i-th shot region A _i is exposed, and the process proceeds to step S13 to increment the shot exposure number i. For example, immediately after the shot exposure in the first row is completed, n = 1 and i = 7, so in step S12, the shot region A ₇ in the second row is exposed as shown in FIG.

In step S14, the control unit 62 determines whether or not the exposure has been completed for all the shot regions belonging to the n + 1th column. Then, when the control unit 62 determines that the exposure of all the shot regions belonging to the n + 1 column has not been completed, the control unit 62 returns to step S11 and determines that the exposure of all the shot regions belonging to the n + 1 column has been completed. If so, the process proceeds to step S15.
For example, when n = 1, the control unit 62 determines in step S14 whether or not the exposure of _{all the shot areas A 7 to} A _{12 belonging to the second row has been completed.} Then, when the control unit 62 _{determines that the exposure has not been completed up to the shot area A 12} , the processing of steps S11 to S13 is repeated. As a result, the shot areas A _{7 to} A ₁₂ belonging to the second row are exposed in order in the direction of the arrow shown in FIG.
By the process up to step S14, for example, when n = 1, the shot exposure of the first row and the second row is completed. At this time, in the first row and the second row adjacent to each other, shot exposure is performed in order in the opposite directions in the Y direction. That is, in the first row and the second row, the upstream side in the exposure direction is the opposite side in the Y direction.

In step S15, the control unit 62 determines whether or not the n + 1th column is the final column. Then, when the control unit 62 determines that the n + 1 column is the final column, it determines that the exposure processing for all the shot areas on the work W has been completed, and proceeds to step S23. If it is determined that there is no such thing, the process proceeds to step S16. In step S16, the control unit 62 sets the column number n = n + 2 to be exposed, and returns to step S4.

For example, when n = 1, n = 3 is set in this step S16. Therefore, in the processing after S4, the same alignment processing and exposure processing as those in the first and second columns are performed for the third and fourth columns. That is, for example, in step S5, as shown in FIG. 10, the control unit 62 uses the camera 51a and the camera 52a to form the first work mark WAM of the _{13th shot area A 13 in the third row and the fourth row. The first work mark WAM of the 24th} shot area A 24 of the above is detected at the same time. _{Further, in step S5, the control unit 62 measures the height position in the 13th} shot area A 13 by the leveler 51b at the same time as the detection of the first work mark WAM, and the leveler 52b measures the height position in the 24th shot area A _24. Measure the height position in.

The processing of steps S17 to S22 is processing for the final column when the nth column (odd number column in the present embodiment) is the final column. In step S17, the control unit 62 controls the work stage control unit 63, and moves the work stage 40 to a position where the camera 51a can detect the first work mark WAM in the _{i-th shot area A i.} Then, it detects the first workpiece mark WAM of the i-th shot area A _i by the camera 51a, for measuring the height position of the i-th shot area A _i by leveler 51b. Since the nth column is the final column, in this step S17, as shown in FIG. 11, the simultaneous search of the first work mark WAM is not performed.
In step S18, the control unit 62 controls the work stage control unit 63, and moves the work stage 40 to a position where the camera 51a can detect the second work mark WAM in the _{i-th shot area A i.} Then, the camera 51a detects the second work mark WAM in the i-th shot area A _i. Also in this case, the simultaneous search of the second work mark WAM is not performed.

In step S19, the control unit 62 controls the workpiece stage control unit 63, the workpiece carrier 40, to move the exposure position of the i-th shot area A _i, in step S20, exposure of the i-th shot area A _i. In step S21, the control unit 62 increments the shot exposure number i. In step S22, the control unit 62 determines whether or not the exposure has been completed for all the shot regions belonging to the nth column. Then, when the control unit 62 determines that the exposure of all the shot regions belonging to the nth column has not been completed, the control unit 62 returns to step S17 and determines that the exposure of all the shot regions belonging to the nth column has been completed. If this is the case, it is determined that the exposure process for all the shot areas on the work W has been completed, and the process proceeds to step S23.
In step S23, the control unit 62 controls the work stage control unit 63 and moves the work stage 40 to a position where the work W can be exchanged. As a result, the exposed work W is in a replaceable state.

As described above, the exposure apparatus 100 in the present embodiment simultaneously detects a plurality of work mark WAMs corresponding to a plurality of different shot regions, and sequentially exposes the plurality of shot regions based on the detection results. .. As a result, the mark search time can be shortened as compared with the case where the work mark WAM formed corresponding to each shot area is sequentially searched for each shot area. Therefore, the alignment for each shot can be appropriately performed without lowering the throughput.

Specifically, the exposure apparatus 100 includes a camera 51a that detects a work mark WAM in a shot region (first shot region) belonging to the nth row arranged along the Y direction, and X with respect to the nth row. It includes a camera 52a that detects a work mark WAM in a shot area (second shot area) belonging to the n + 1th column adjacent to the direction. Then, the camera 51a detects the work mark WAM in the first shot area and the camera 52a detects the work mark WAM in the second shot area at the same time, and based on the detection result, the first shot area is detected. The position information and the position information of the second shot area are calculated and stored. At this time, the exposure apparatus 100 exposes the shot region belonging to the nth column based on the position information of the shot region belonging to the nth column.
The exposure apparatus 100 repeatedly calculates the position information of the first shot area and the position information of the second shot area, and exposes the shot area belonging to the nth column in order along the Y direction. In this way, the exposure apparatus 100 sequentially exposes the shot regions belonging to the nth column while calculating the position information of the shot regions for the nth column and the n + 1th column, respectively.

When the exposure to all the shot areas belonging to the nth column is completed, the exposure apparatus 100 calculates and stores the position information of the shot areas belonging to the n + 1 column when the shot areas belonging to the nth column are exposed. , The shot area belonging to the n + 1th column is exposed. At this time, since the position information is calculated and stored at the time of exposure to the nth column for each shot area in the n + 1 column, shot exposure can be continuously performed using the stored position information. In this way, by simultaneously searching a plurality of work mark WAMs corresponding to a plurality of different shot areas, the tact time can be shortened and the throughput can be appropriately improved.
Further, the exposure apparatus 100 performs shot exposure in order in the opposite direction in the Y direction in the nth row and the n + 1th row adjacent to each other in the X direction. Therefore, after the exposure of the nth row is completed, the exposure of the n + 1th row can be started by minimizing the movement of the work stage 40. Therefore, the takt time can be effectively shortened.

Further, since the exposure apparatus 100 detects two work marks (first work mark WAM and second work mark WAM) for each shot area, alignment including rotation of each shot area is possible. For example, in a work W on which a chip is mounted, when a pattern is further transferred onto the chip, the orientation of the chip differs depending on the mounting accuracy of the chip, and the inclinations of a plurality of shot regions on the work W are different. It may be different. Even in such a case, appropriate alignment can be performed for each shot region, and the superposition accuracy can be improved.

Further, as shown in FIG. 2, if the distances of the two work marks WAM to be simultaneously searched in the X direction are constant in the nth column and the n + 1th column, the position of the camera 52a in the X direction each time the mark is searched. There is no need to adjust, and the tact time can be shortened accordingly.
Further, in the exposure apparatus 100 of the present embodiment, the camera 51a is arranged at the position of the optical axis of the projection optical system in the X direction. Therefore, as shown in FIG. 2, if the work mark WAM corresponding to the shot area belonging to the nth column is arranged in a row in the Y direction at the center position in the X direction of the shot area, the simultaneous search of the work mark WAM and the second work mark WAM can be performed. The tact time when performing n-row shot exposure can be shortened as much as possible.
As described above, the exposure apparatus 100 according to the present embodiment can appropriately perform alignment for each shot and perform high-precision sequential exposure without lowering the throughput.

(Modification example)
In the above embodiment, the work mark WAM shown in FIG. 2 has been described as an example, but the work mark WAM is not limited to the arrangement shown in FIG. The work mark WAM corresponding to each shot area may be one or three or more. Further, the work mark WAM is not limited to that formed in each shot region as shown in FIG. 2, and may be formed outside each shot region. Further, the work mark WAM may be shared by a plurality of shot areas.
Further, in the above embodiment, the case where a plurality of shot areas are formed in a grid pattern on the work W has been described, but the arrangement of the shot areas is not limited to the above, and may be an arbitrary arrangement. be able to.

Further, in the above embodiment, the case where two detection units 51 and 52 are provided for detecting the work mark WAM has been described, but as shown in FIG. 12, for example, three detection units 51 to 53 are provided. You may. The detection unit 53 can have the same configuration as the detection units 51 and 52. In this case, the exposure apparatus 100 can detect the work mark WAM in three rows at the same time by the cameras provided by the three detection units 51 to 53, respectively. The operation when performing a three-column simultaneous search will be described below.
For example, as shown in FIG. 13, when 6 shot regions are formed on the work W in the X direction and 6 shot regions in the Y direction, first, the arrows in the drawings in the first to third rows are simultaneously formed. Mark search is performed in order in the direction of. At this time, as shown in FIG. 14, the first column is subjected to shot exposure while performing a mark search. After the exposure to all the shot regions belonging to the first column is completed, the shot exposure to the shot regions belonging to the second column is then performed as shown in FIG. At this time, for the second row, shot exposure is continuously performed in the direction of the arrow in FIG.

As shown in FIG. 16, when the exposure to all the shot areas belonging to the second column is completed, then the shot areas belonging to the third column are continuously shot exposed in the same manner as in the second column. conduct. However, in the second row and the third row, the upstream side in the exposure direction is opposite in the Y direction. That is, for the third column, shot exposure is performed in the direction indicated by the arrow in FIG. Then, when the exposure to all the shot areas belonging to the third row is completed, the work W is moved in the Y direction, and the position of each camera with respect to the work W is returned to the position shown in FIG.
After that, the same alignment processing and exposure processing as those in the first to third columns described above are performed on the fourth to sixth columns. That is, first, as shown in FIG. 19, mark search is performed in the direction of the arrow in the figure at the same time in the three columns of the fourth column to the sixth column.

Further, as shown in FIG. 20, four detection units 51 to 54 may be provided. In this case, the exposure apparatus 100 can detect the work mark WAM in four rows at the same time by the cameras provided by the four detection units 51 to 54, respectively. When the number of detection units (cameras) is an even number in this way, the work W is moved in the Y direction as shown in FIG. 18 after the exposure to all the shot areas belonging to the fourth column is completed (the camera is moved). The operation of returning) is not necessary, and it is possible to directly shift to the mark search in the fifth and subsequent columns.
As described above, the number of detection units (cameras) may be three or more. As the number of columns for simultaneous search of work mark WAM increases, the time required for searching all work mark WAM on the work W can be shortened, and the throughput can be improved accordingly.

Further, in the above embodiment, in the exposure of the nth column, the first work mark WAM and the second work mark WAM are detected in order, the position information of the shot area is calculated, and then the shot is shot with respect to the shot area. The case where the first work mark WAM corresponding to the next shot region is detected after the exposure is applied has been described. However, when the second work mark WAM is detected, if the first work mark WAM corresponding to the next shot area is in the camera field of view, the first work mark WAM is also detected at the same time. You may. As a result, the time required for the mark search can be further shortened, and the throughput can be improved.

Further, in the above embodiment, the case where the first work mark WAM and the second work mark WAM are searched in order with one camera has been described. However, if there are no restrictions on the arrangement space or maintenance, a camera for detecting the first work mark WAM and a camera for detecting the second work mark WAM are provided, and the first work mark WAM and the second work are provided. The mark WAM and the mark WAM may be detected at the same time. In this case as well, the time required for the mark search can be further shortened, and the throughput can be further improved.

100 ... exposure device, 10 ... light irradiation unit, 20 ... mask stage, 30 ... projection optical system, 40 ... work stage, 51, 52 ... detection unit, 51a, 52a ... camera, 51b, 52b ... leveler, M ... mask, MAM ... Mask alignment mark, W ... Work, WAM ... Work alignment mark

Claims (7)

An exposure apparatus that sequentially transfers a pattern formed on a mask to a plurality of shot regions formed on a work piece via a projection optical system.
The plurality of shot regions are arranged on the work along a first direction and a second direction different from the first direction, respectively.
A plurality of the first shot regions formed on the work and belonging to the first row arranged along the first direction among the plurality of shot regions are used as the first shot region, respectively . a first detector for detecting each alignment mark corresponding to one shot area,
A plurality of the second shots formed on the work, each of which is a plurality of shot regions belonging to the second row adjacent to the first row in the second direction as the second shot region. a second detector for detecting each alignment mark corresponding to the area,
A control unit that controls the transfer of the plurality of shot regions is provided .
The control unit
With respect to the first shot region and the second shot region belonging to one row adjacent to the second direction, the first detection unit detects the alignment mark and the second detection unit detects the alignment mark. perform detection at the same time, pre-SL based on the first detection unit and the detection result by the second detection unit, and positional information of the position information and the second shot area of the first shot region is calculated respectively stored, subsequently, on the basis of the position information of the calculated first shot area, the alignment of the first shot area and the mask I line, the to first shot area The process of performing the transfer is repeated line by line along the first direction.
After performing the transfer to all the first shot regions belonging to the first row, based on the location information of all the second shot regions belonging to the second row stored, Aligning the mask with the second shot region, and performing the transfer to all the second shot regions belonging to the second row in order in the first direction. An exposure apparatus characterized by. The control unit
The exposure apparatus according to claim 1, wherein the transfer is sequentially performed in the opposite directions in the first direction in each row adjacent to each other in the second direction. The control unit
After performing the transfer to all the second shot regions belonging to the second row, the second row is adjacent to the second row on the opposite side of the first row. The exposure apparatus according to claim 1 or 2, wherein the column is newly set as the first column. The control unit
When the row newly set as the first row is the endmost row in the second direction, only the alignment mark is detected by the first detection unit, and the alignment by the second detection unit is performed. The exposure apparatus according to claim 3, wherein the mark is not detected. The exposure apparatus according to any one of claims 1 to 4, wherein the second shot region is a plurality of shot regions adjacent to each other in the second direction. The first detection unit is arranged on one side in the first direction with respect to the optical axis of the projection optical system.
The exposure apparatus according to any one of claims 1 to 5, wherein the second detection unit is arranged apart from the first detection unit in the second direction. An exposure method in which a pattern formed on a mask is sequentially transferred to a plurality of shot regions formed on a work piece via a projection optical system.
The plurality of shot regions are arranged on the work along a first direction and a second direction different from the first direction, respectively.
A plurality of shot regions formed on the work and belonging to the first row arranged along the first direction among the plurality of shot regions are designated as the first shot regions, respectively.
A plurality of shot regions formed on the work and belonging to the second row adjacent to the first row in the second direction are designated as the second shot regions, respectively.
The corresponding alignment marks are simultaneously detected for the first shot region and the second shot region belonging to one row adjacent to the second direction, and based on the detection result of the alignment marks, the second shot region is detected. 1 of the position information and the position information of the second shot area of the shot area is calculated and stored, respectively, Subsequently, based on the position information of the calculated first shot area, the said mask first What line alignment between the first shot area, a first transfer step of the transfer performs processing, intends repeated lines sequentially one line along the first direction of said to first shot area When,
After performing the transfer to all the first shot regions belonging to the first row, all the second shot regions belonging to the second row stored in the first transfer step Based on the position information, the mask and the second shot region are aligned, and the transfer to all the second shot regions belonging to the second row is performed in the first direction. An exposure method comprising a second transfer step, which is continuously performed in order of.

Images