KR102437875B1 - Measuring method, measuring apparatus, exposing apparatus, and method of manufacturing article - Google Patents

Abstract

[Problem] To provide a measurement method advantageous for reducing measurement error of distortion.
[Solutions] The measurement method comprises: shot exposure for transferring to a substrate a first pattern having a plurality of first marks arranged at predetermined intervals in the row and column directions, respectively, arranged on an object plane of the projection optical system, onto a substrate; a first step of forming a plurality of first patterns in the row and column directions, respectively, by performing a plurality of times while shifting them in the row and column directions so as not to cause overlap with the object; In a shot exposure in which a second pattern having a plurality of second marks arranged at predetermined intervals in each direction and a plurality of peripheral marks positioned on the periphery of the plurality of second marks is transferred to a substrate, a partial region of the adjacent shot is performed. A second step of forming a plurality of second patterns in the row and column directions, respectively, by performing a plurality of times while shifting them in the row and column directions so as to overlap, and the amount and part of the shift between the first mark and the second mark transferred to the substrate A third step of obtaining distortion is provided based on the amount of displacement between the peripheral marks in the region.

Description

A measurement method, a measurement apparatus, an exposure apparatus, and an article manufacturing method TECHNICAL FIELD

The present invention relates to a measurement method, a measurement apparatus, an exposure apparatus, and an article manufacturing method for measuring distortion representing distortion of an image projected on a substrate through a projection optical system.

A method for obtaining distortion of a projection optical system of an exposure apparatus using a plurality of main scale marks and a plurality of minor scale marks formed on a test mask is disclosed in Japanese Patent Laid-Open No. 2004-063905 (Patent Document 1). Moreover, the method of solving the fall of the distortion measurement precision by the time-dependent change of the relative distance between marks which generate|occur|produces during implementation of the method is disclosed by Unexamined-Japanese-Patent No. 2011-35009 (patent document 2).

(1) Distortion measurement method disclosed in Patent Document 1

In this measurement method, for example, the first mark and the second mark are a minor mark and a major mark corresponding to the respective patterns. In the first process, a shot in which the first marks 10 are arranged in m ₁ row n ₁ column (m ₁ =n ₁ =3 in the drawing) as shown in FIG. m ₂ rows and n ₂ columns are exposed as shown (m ₂ =n ₂ =2 in the drawing).

Subsequently, in the second process, as shown in FIG. 7(c), a shot in which second marks 11 having the same spacing as the first marks 10 in m ₁ row n ₁ column are arranged in m ₂ row n ₂ columns, as shown in FIG. As in (d) of 7, m ₁ row and n ₁ column are exposed. Thereby, N=m ₁ x n ₁ x m ₂ x n ₂ overlapping marks are generated.

Thereafter, the amount of deviation of the generated overlapping marks is measured, and distortion is calculated based on the amount of deviation.

(2) Distortion measurement method disclosed in Patent Document 2

This measurement method is based on the measurement method of patent document 1. In this measurement method, a shot in which the second marks 11 are arranged in m ₂ rows and n ₂ columns is exposed once as a third process before the execution of the second process. Further, after the second step is executed, as a fourth step, a shot in which the second marks 11 are arranged in m ₂ rows and n ₂ columns is exposed once. Further, as a fifth step, a shot in which the second marks 11 in the m ₂ row and the n ₂ column and the third marks are arranged in the same number and the same spacing are exposed twice.

Subsequently, (m 2 ×n 2 ×2) second marks formed in the third and fourth steps and (m ₂ ×n ₂ × ₂ ) third marks formed in the fifth step ( _{m 2} ) The amount of deviation of xn ₂ x 2) overlapping marks is measured. Then, based on the measured shift amount, the relative position change between the marks of each exposure shot in the second step is estimated. In addition, distortion is calculated by adding the shift amount obtained from the overlapping marks generated in the first process and the second process with the estimated change in the relative position between the marks.

Japanese Patent Laid-Open No. 2004-063905 Japanese Patent Laid-Open No. 2011-035009

In the distortion measurement method described in Patent Document 1, it is a prerequisite that the relative positions between the plurality of minor scale marks and the relative positions between the plurality of major scale marks are constant. In Patent Document 2, it is explained that the change in the relative position between the main scale marks cannot be ignored and countermeasures are necessary. .

However, the temporal change of the relative position between marks is due to various factors such as exposure heat generated during exposure, deformation of the projection system, and motor heat of the stage. Therefore, in the conventional measurement method, the measurement error of distortion increases due to a change in the relative position between marks, and good measurement accuracy cannot be obtained.

An object of the present invention is to provide a measurement method advantageous for reducing measurement errors of, for example, distortion.

According to one aspect of the present invention, there is provided a measurement method for measuring distortion indicating distortion of an image projected on a substrate through a projection optical system, arranged on an object plane of the projection optical system and arranged at predetermined intervals in the row and column directions, respectively. The first pattern is formed by performing shot exposure for transferring a first pattern having a plurality of first marks onto the substrate a plurality of times while shifting each in the row direction and the column direction so that overlap with adjacent shots does not occur. A first step of forming a plurality of marks in the row direction and the column direction, respectively; By performing a shot exposure for transferring a second pattern having a plurality of peripheral marks positioned on the periphery of the two marks onto the substrate a plurality of times while shifting each in the row direction and the column direction so that a partial region of an adjacent shot overlaps, a second step of forming a plurality of the second patterns in the row direction and the column direction, respectively; A measurement method is provided, comprising a third step of calculating the distortion based on the amount of shift.

ADVANTAGE OF THE INVENTION According to this invention, the measuring method advantageous for reduction of the measuring error of, for example of distortion can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the exposure apparatus in embodiment.
Fig. 2 is a diagram showing an example of a mark disposed on a mask used for measurement of distortion;
Fig. 3 is a flowchart showing distortion measurement processing according to the embodiment;
Fig. 4 is a diagram for explaining a distortion measurement process in the embodiment;
Fig. 5 is a view showing an example of an overlap mark formed on a substrate;
Fig. 6 is a diagram for explaining distortion measurement processing in the second embodiment;
Fig. 7 is a view for explaining a conventional distortion measurement method;

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to drawings. In addition, the following embodiment only shows the specific example of implementation of this invention, and this invention is not limited to the following embodiment. In addition, not all combinations of features described in the following embodiments are essential for solving the problems of the present invention.

<First embodiment>

1 : is a figure which shows the schematic structure of the exposure apparatus which concerns on this embodiment. The exposure apparatus 40 is a lithographic apparatus that exposes a substrate through a projection optical system, and includes a measurement apparatus that measures distortion representing distortion of an image projected onto the substrate through the projection optical system. Here, the optical axis direction of the projection optical system 45 is the Z axis, and the direction along the substrate surface orthogonal thereto is the XY direction.

The mask stage 43 holds the mask 48 which is an original plate. The mask 48 is disposed on the object plane of the projection optical system 45 by the mask stage 43 . The substrate stage 46 is configured to be movable while holding the substrate 49 . The illumination optical system 42 illuminates the mask 48 held by the mask stage 43 with light from the light source 41 .

The light shielding plate 44 restricts the light from the illumination optical system 42 so that a predetermined area in the mask 48 is one shot. In FIG. 1 , the light blocking plate 44 is disposed below the mask stage 43 , but there may be a configuration in which the light blocking plate 44 is disposed inside the illumination optical system 42 . The projection optical system 45 projects the image of the mark or the pattern of the mask 48 illuminated by the illumination optical system 42 .

The detection unit 47 includes, for example, a microscope, and detects a mark formed on the substrate. The control unit 50 controls the operation of each unit in the exposure apparatus 40 . The control unit 50 may be configured as a computer device including a CPU 51 and a memory 52 . The CPU 51 executes various controls in accordance with the control program 52d stored in the memory 52 . The memory 52 stores a measurement processing program 52a for performing distortion measurement. The CPU 51 controls the substrate stage 46 and the detection unit 47 to measure the marks on the substrate 49 by executing the measurement processing program 52a, and calculates the distortion amount and the correction value 52b. Therefore, the measurement apparatus in this embodiment can be comprised by the detection part 47 and the control part 50 (processing part). The correction value 52b is stored in the memory 52 . In addition, the exposure operation 52c is also stored in the memory. The exposure operation 52c may include various parameters in the exposure processing at the time of distortion measurement and the exposure processing at the time of device production. The control unit 50 controls the exposure process for exposing the substrate so as to reduce the measured distortion.

Next, with reference to FIG. 2, the mask 48 used for distortion measurement is demonstrated. Here, the X direction is referred to as a row direction (first direction), and the Y direction orthogonal to the X direction is referred to as a column direction (second direction). As shown in Fig. 2, the mask 48 has a plurality of first marks 1 arranged at a predetermined interval Px1 in the X direction and a predetermined interval Py1 in the Y direction, in m ₁ rows and n ₁ columns. has been In the example of Fig. 2, m ₁ =n ₁ =3. Moreover, on the mask 48, the some _2nd mark ₂ of more than m2 row n2 columns arrange|positioned at the same space|interval as the some 1st mark 1 is arrange|positioned. In the example of Fig. 2, m ₂ =n ₂ =2. In addition, the arrangement position of the some 2nd mark 2 is made into the to-be-exposed surface of the mask 48 arbitrarily. In this embodiment, the 1st mark 1 and the 2nd mark 2 are demonstrated as a minor mark and a main scale mark, respectively.

Moreover, the some periphery mark located in the periphery of the some 2nd mark 2 is arrange|positioned on the mask 48. As shown in FIG. In the present embodiment, the plurality of peripheral marks include a third mark 3 , a fourth mark 4 , a fifth mark 5 and It may include a sixth mark (6). For example, the mask 48 has m ₃ third marks 3 and m ₃ third marks 3 at a constant interval (Py1×n ₂ ) in the Y direction from each of the m ₃ third marks 3 . 4 marks 4 are placed. In addition, the mask 48 has m ₄ fifth marks 5 and m ₄ 6th marks at regular intervals (Px1×m ₂ ) in the X direction from each of the m ₄ fifth marks 5 . (6) is placed. The arrangement method and arrangement position of the 3rd mark 3 of m ₃ , and the arrangement method and arrangement position of the m ₄ piece 5th mark 5 are arbitrary. In the present embodiment, m ₃ =m ₄ =4. In addition, the arrangement method of the m ₃ 3rd marks 3 and the arrangement method of the m ₄ 5th marks 5 are set as 2 rows, 2 columns arrangement|positioning which respectively became constant space|interval in the X and Y directions.

Here _{, the} relationship between m1, m2, _m3 , _m4 , _n1 , _n2 is demonstrated. In the present embodiment, let m ₁ and m ₂ be mutually prime natural numbers having a relationship of m ₁ >m ₂ . Similarly, let n ₁ and n ₂ be mutually prime natural numbers having a relationship of n ₁ >n ₂ . _In addition, let _m3 and m4 be a natural number, respectively. In addition, as described above, in this embodiment, m ₁ =n ₁ =3, m ₂ =n ₂ =2, m ₃ =m ₄ =4.

In addition, in this embodiment, the center point of the straight line which connects the center position of the 3rd mark 3 of m ₃ and the center position of the 4th mark 4 of m ₃ is m2xn _{2 2nd} mark ( 2), m ₃ 3rd marks 3 and m ₃ 4th marks 4 are arrange|positioned so that it may overlap with the center position. Similarly, in this embodiment, the center point of the straight line connecting the center position of the m ₄ 5th mark 5 and the center position of the m ₄ 6th mark 6 is m ₂ x n ₂ 2nd mark ( 2), m ₄ 5th marks 5 and m ₄ 6th marks 6 are arrange|positioned so that it may overlap with the center position. In addition, let the 3rd mark 3 and the 4th mark 4 be a main scale mark, and let the 5th mark 5 and the 6th mark 6 be a minor scale mark. Furthermore, in this embodiment, let the 3rd mark 3 and the 5th mark 5 be the marks of the same pattern, and let the 4th mark 4 and the 6th mark 6 be the marks of the same pattern.

In addition, in this embodiment, the 1st mark 1, the 2nd mark 2, the 3rd mark 3, the 4th mark 4, the 5th mark 5, and the 6th mark 6 are the same It was placed on the mask 48 . However, the first mask on which the first mark 1 is disposed, the second mark 2 , the third mark 3 , the fourth mark 4 , the fifth mark 5 and the sixth mark 6 . You may prepare separately the 2nd mask in which is arrange|positioned. In addition, in this embodiment, as will be described later, the second mark 2 is a Box-in-Box pattern transferred within the range of the first mark 1, and the third mark 3 is the fourth mark ( It has a box-in-box pattern that is transferred within the range of 4). Likewise, the fifth mark 5 has a pattern of Box-in-Box which is transferred within the range of the sixth mark 6 . However, the present invention is not limited thereto, and any pattern in which the relative position of the mark can be measured may be sufficient.

Next, the distortion measurement method will be described in order. 3 is a flowchart illustrating a distortion measurement process. The program corresponding to this flowchart is included in the measurement processing program 52a, and is executed by the control part 50 (CPU 51).

In S101, the control unit 50 performs the shot exposure for transferring the first pattern having the plurality of first marks 1 to the substrate a plurality of times while shifting the shot exposure in the row direction and the column direction so as not to overlap with adjacent shots. do Thereby, a plurality of first patterns are respectively formed in the row direction and the column direction. Specifically, as shown in FIG. 4A , the control unit 50 controls the light blocking plate 44 so that the first pattern having the first marks 1 of m ₁ rows and n ₁ columns arranged on the mask 48 is exposed. ) is driven Then, as shown in FIG. 4B , the control unit 50 drives the substrate stage 46 in the XY direction and repeats the shot exposure for transferring the first pattern to the substrate m ₂ ×n ₂ times. As a result, first marks 1 of (m1×m2) rows (n1×n2) columns are formed on the substrate (exposure treatment of the first layer (first step)).

In S102, the control unit 50 performs a shot exposure for transferring a second pattern having a plurality of second marks 2 and a plurality of peripheral marks positioned on the periphery thereof onto the substrate, in a matrix such that some regions of adjacent shots overlap. This is performed a plurality of times while shifting each direction in each direction. Thereby, a plurality of second patterns are respectively formed in the matrix direction. Specifically, as shown in FIG. 4(c), the control unit 50 includes the second mark 2 of m ₂ rows and n ₂ columns, m ₃ third marks 3, and m ₃ fourth marks ( The light blocking plate 44 is driven so that an area including 4) and m ₄ fifth marks 5 and m ₄ sixth marks 6 can be exposed. Then, as shown in FIGS. 4(d) and 5 , the control unit 50 repeats the shot exposure for transferring the second pattern onto the substrate (m ₁ ×n ₁ ) times. In Fig. 5, an example of an overlap mark formed on the substrate 49 by this process is shown. Although this shows the same result as FIG. 4(d), in FIG. 5, the image of the board|substrate which left only the overlap mark 30, the overlap mark 31, and the overlap mark 32 is shown for easy understanding. Accordingly, ((m ₁ −1)×n ₁ ) first overlapping regions R1 and (m ₁ ×(n ₁ −1 )) second overlapping regions R2 are formed in the substrate. Then, the control unit 50 forms the second mark 2 of the (m ₁ × m ₂ ) row (n ₁ × n ₂ ) column on the first mark 1 . In addition, the control unit 50 forms m _{3 third marks 3 and m 3 fourth} marks 4 in each of the first overlapping regions R1 . In addition, the control unit 50 forms m _{4 fifth marks 5 and m 4 sixth} marks 6 in each of the second overlapping regions R2 (exposure treatment of the second layer (second process)) ).

In addition, the developing process is not interposed between the exposure processes of S101 and S102. In addition, the processing order of S101 and S102 may be interchanged.

In S103, the control unit 50 takes out the substrate 49 and develops it in a developing machine outside the exposure apparatus. As a result, m ₁ × n ₁ × m ₂ × n ₂ overlapping marks 30 are formed by the first mark 1 exposed in S101 and the second mark 2 exposed in S102. In addition, (m ₃ × (m ₁ −1) × n ₁ ) overlapping marks 31 by the third mark 3 and the fourth mark 4 exposed in S102, the fifth mark 5 and the second mark (m ₄ x m ₁ x (n ₁ -1)) overlapping marks 32 by 6 marks 6 are formed.

In S104 , the control unit 50 measures the overlap mark formed on the substrate 49 using the detection unit 47 . In addition, you may perform this measurement using not the detection part 47 mounted in the exposure apparatus 40 but the measuring instrument outside the exposure apparatus.

In S105, the control part 50 calculates|requires a distortion based on the shift amount of the 1st mark and 2nd mark transferred to the board|substrate, and the shift|offset|difference amount of the peripheral marks in the said partial area|region (3rd process). Specifically, the control unit 50 solves the equation by substituting the measured values of the overlap marks into the equations shown in equations 1 to 25 described below.

here,

δ _x (n), δ _y (n): the measured value of the overlap mark of the n-th first layer exposure shot and the second layer exposure shot;

dx ₁ (i), dy ₁ (i): misalignment of the ith distortion evaluation (first mark),

dx ₂ (j), dy ₂ (j): misalignment of the j-th main scale (second mark) for measurement,

ex ₁ (k), ey ₁ (k), t ₁ (k): alignment error of the k-th shot of the first layer (x-direction shift, y-direction shift, common rotation in x-direction and y-direction)

ex ₂ (l), ey ₂ (l): alignment error (x-direction shift, y-direction shift) of the l-th shot of the second layer,

tx ₂ (l), ty ₂ (l), mx ₂ (l), my ₂ (l): shape change of the lth shot of the second layer (rotation in x direction, rotation in y direction, magnification in x direction, magnification in y direction) and corresponds to a change in the relative position between marks)

X ₁ (i), Y ₁ (i): In-shot coordinates of the i-th mark of the first layer (mark position relative to the shot center)

X ₂ (j), Y ₂ (j): the coordinates in the shot of the j-th mark of the second layer

ε _x (n), ε _y (n), : quantization error due to rounding

δ _xv (p), δ _yv (p): measured value of the p-th overlap mark in the y-direction adjacent region of the second layer exposure shot

dx ₃ (j _v ), dy ₃ (j _v ): misalignment of the j _v -th overlapping minor mark (third mark) in the y-direction adjacent area of the second layer exposure shot;

dx ₄ (j _v ), dy ₄ (j _v ): misalignment of the j _v -th overlapping principal scale mark (fourth mark) in the y-direction adjacent area of the second layer exposure shot;

X ₃ (j _v ), Y ₃ (j _v ): In-shot coordinates of the j _v -th overlapping minor mark (third mark) in the y-direction adjacent area of the second layer exposure shot,

X ₄ (j _v ), Y ₄ (j _v ): in-shot coordinates of the j _v -th overlapping principal scale mark (fourth mark) of the second layer exposure shot y-direction adjacent area;

ε _xv (p), ε _yv (p): quantization error due to rounding,

δ _xh (q), δ _yh (q): the measured value of the q-th overlap mark in the x-direction adjacent region of the second layer exposure shot,

dx ₅ (j _h ), dy ₅ (j _h ): misalignment of the j _h -th overlapping minor mark (fifth mark) in the x-direction adjacent area of the second layer exposure shot;

dx ₆ (j _h ), dy ₆ (j _h ): misalignment of the j _h -th overlapping principal scale mark (sixth mark) in the x-direction adjacent area of the second layer exposure shot;

X ₅ (j _h ), Y ₅ (j _h ): the coordinates within the shot of the j _h -th overlapping subordinate mark (fifth mark) in the x-direction adjacent area of the second layer exposure shot,

X ₆ (j _h ), Y ₆ (j _h ): In-shot coordinates of the j _h -th overlapping principal scale mark (sixth mark) in the x-direction adjacent area of the second layer exposure shot;

ε _xh (q), ε _yh (q): quantization error due to rounding

indicates

Also, if ε _x (n), ε _y (n), ε _xv (p), ε _yv (p), ε _xh (q), and ε _yh (q) are sufficiently small to be ignored, the unknown variable is becomes like

(m ₁ ×n ₁ ) dx ₁ (i), dy ₁ (i), ex ₂ (l), ey ₂ (l), tx ₂ (l), ty ₂ (l), mx ₂ (l) , my ₂ (l),

(m ₂ ×n ₂ ) dx ₂ (j), dy ₂ (j), ex ₁ (k), ey ₁ (k), t ₁ (k),

m _three dx _u (j _v ), dy _u (j _v ), dx _d (j _v ), dy _d (j _v ),

m _four dx _l (j _h ), dy _l (j _h ), dx _r (j _h ), dy _r (j _h ).

Therefore, the number of unknowns is (8×m ₁ ×n ₁ +5×m ₂ ×n ₂ +4×m ₃ +4×m ₄ ).

On the other hand, the overlapping marks of the first layer and the second layer are formed from the following.

·(m ₁ × n ₁ ) minor marks i,

·(m ₂ × n ₂ ) main scale marks j,

(m ₂ ×n ₂ ) first layer exposure shots k,

· (m ₁ ×n ₁ ) second layer exposure shots l.

i, j, k, and l for each superimposed mark are different combinations for all marks.

Next, the overlap marks in the area adjacent to the second layer exposure shot in the y direction are m ₃ subscale marks/main scale marks j _v , ((m ₁ −1)×n ₁ ) second layer exposure shots (l) and the second It is formed from the y-direction adjacent region of the layer exposure shot (l+m ₁ ). j _v , l for each superimposed mark is a different combination in all marks.

In addition, the overlap marks in the area adjacent to the second layer exposure shot x-direction are m ₄ subscale marks/main scale marks j _h , (m ₁ ×(n ₁ −1)) second layer exposure shot (l) and the second layer exposure shot (l) It is formed from the x-direction adjacent region of the two-layer exposure shot (l+1). j _h , l for each overlap mark is a different combination for all marks.

That is, Equations 1 to 6 sum to (2×(m ₁ ×n ₁ ×m ₂ ×n ₂ )+2×m ₃ ×(m ₁ -1)×n ₁ +2×m ₄ ×m ₁ ×( n ₁ -1)) simultaneous equations.

At this time, if the conditions of Expressions 7 to 25 shown below are added, this simultaneous equation becomes non-negative, and ε _x (n), ε _y (n), ε _xv (p), ε _yv (p), ε A solution is obtained that minimizes the square function of _xh (q) and ε _yh (q).

Here, C _x (l) and C _y (l) represent the arrangement coordinates (the shot center position with respect to the plate center) of the l-th exposure shot of the second layer.

When the above simultaneous equations are solved, not only the distortion evaluation amounts dx ₁ and dy ₁ but also the following are obtained simultaneously.

Arrangement error of stage ex ₁ , ey ₁ , t ₁ , ex ₂ , ey ₂ ,

・Shape change of the exposure shot of the second layer tx ₂ , ty ₂ , mx ₂ , my ₂ ,

・Error in mask manufacturing dx ₂ , dy ₂ , dx ₃ , dy ₃ , dx ₄ , dy ₄ , dx ₅ , dy ₅ , dx ₆ , dy ₆ .

Therefore, the distortion evaluation amount does not include the stage arrangement error and the shape change of the exposure shot of the second layer.

<Second embodiment>

With reference to FIG. 6, as 2nd Embodiment, the method of substituting 3rd mark, 4th mark, 5th mark, and 6th mark with a 2nd mark is demonstrated.

As shown in FIG. 6A , the first layer exposure shot by the first mark 1 in the m ₁ column and n ₁ column is the same as in the first embodiment, m ₁ is 3 and n ₁ is 3 do.

As shown in FIG. 6B , the second mark 2 in the (m ₂ +2) row (n ₂ +2) column is used as the second layer exposure shot. Here, similarly to the first embodiment, m ₂ is 2 and n ₂ is 2. In addition, the second mark 2 of the m ₂ row n ₂ at a position close to the center of the second mark 2 of the (m ₂ +2) row (n ₂ +2) column is the second mark of the first embodiment It corresponds to (2).

Next, as in the first embodiment, the exposure shot of the first layer and the exposure shot of the second layer are respectively exposed to m ₂ row n ₂ column and m ₁ row n ₁ column, and (m ₁ ×n ₁ ×m ₂ ) xn ₂ ) overlapping marks are formed. However, as in the first embodiment, when exposure is performed with the target position at an ideal position where the centers of the sub-scale mark and the main-scale mark of each overlapping mark overlap each other, the main-scale marks from the shots of the second layer different from each other will be covered and measured. There is a possibility that it will not be possible. Therefore, as shown in Fig. 6(c), the exposure shot of each first layer is left at the abnormal position, and the exposure shot of each second layer is exposed by offsetting the abnormal position by a certain distance along different directions from the abnormal position. . Thereby, it is possible to prevent the principal-scale marks from exposure shots of different second layers from covering each other. Each of the (m ₁ × n ₁ × m ₂ × n ₂ ) overlapping marks is a mark group formed of one minor mark and one or more main scale marks, and these are the measurement objects in the present embodiment.

Then, from each of the (m ₁ × n ₁ × m ₂ × n ₂ ) mark groups, one minor mark and all of the one or more main scale marks are each measured, and distortion is calculated.

<Embodiment of article manufacturing method>

The article manufacturing method in the embodiment of the present invention is suitable for manufacturing articles such as microdevices such as semiconductor devices and elements having a microstructure, for example. The article manufacturing method of the present embodiment comprises a step of transferring a pattern of an original plate onto a substrate using the lithographic apparatus (exposure apparatus, imprint apparatus, drawing apparatus, etc.) include In addition, this manufacturing method includes other well-known processes (oxidation, film-forming, vapor deposition, doping, planarization, etching, resist peeling, dicing, bonding, packaging, etc.). The article manufacturing method of the present embodiment is advantageous compared to the conventional method in at least one of performance, quality, productivity, and production cost of the article.

40: exposure device
41: light source
42: illumination optical system
45: projection optical system
46: substrate stage
47: detection unit
48: mask
49: substrate
50: control unit

Claims (15)

A measurement method for measuring distortion indicating distortion of an image projected on a substrate through a projection optical system,
Shot exposure for transferring to the substrate a first pattern having a plurality of first marks arranged at predetermined intervals in the row and column directions arranged on the object plane of the projection optical system on the substrate, overlap with adjacent shots does not occur a first step of forming a plurality of the first patterns in the row direction and the column direction by performing a plurality of times while shifting them in the row direction and the column direction, respectively;
a second pattern having a plurality of second marks arranged at the predetermined intervals in the row direction and the column direction, respectively, disposed on the object plane, and a plurality of peripheral marks positioned around the plurality of second marks; forming a plurality of the second patterns in the row direction and the column direction by performing the shot exposure transferred to the substrate a plurality of times while shifting each in the row direction and the column direction so that partial regions of adjacent shots overlap a second process;
a third step of obtaining the distortion based on the amount of deviation between the first mark and the second mark transferred to the substrate and the amount of deviation between the peripheral marks in the partial region;
wherein the plurality of peripheral marks include a third mark, a fourth mark, a fifth mark, and a sixth mark, respectively disposed at different positions around the plurality of second marks;
In the second process, the third mark and the fourth mark are formed in a first overlapping area in which a portion of two shots adjacent in a column direction among the partial areas overlap, and the third mark and the fourth mark are formed adjacent to each other in a row direction among the partial areas. forming a plurality of the second patterns in the row direction and the column direction so that the fifth mark and the sixth mark are formed in a second overlapping area where a portion of the two shots overlap;
The third process includes a first shift amount that is a shift amount between the first mark formed on the substrate in the first process and the second mark formed on the substrate in the second process, and the first offset by the second process. A second shift amount that is a shift amount between the third mark and the fourth mark formed in the overlapping region, and a third shift amount that is a shift amount between the fifth mark and the sixth mark formed in the second overlap region by the second step Based on , to obtain the distortion
A measurement method, characterized in that. According to claim 1,
Let m ₁ and m ₂ be mutually prime natural numbers having a relationship of m ₁ >m ₂ ,
Let n ₁ and n ₂ be mutually prime natural numbers having a relationship of n ₁ >n ₂ , and
When m ₃ and m ₄ are each a natural number,
The first step is performed by repeating shot exposure for transferring the first pattern having the first marks in m ₁ rows and n ₁ columns to the substrate (m ₂ × n ₂ ) times, whereby (m ₁ × m ₂ ) rows (n ₁ × n ₂ ) forming the first marks in a column on the substrate,
The second process is
By repeating the shot exposure for transferring the second pattern to the substrate (m ₁ ×n ₁ ) times, ((m ₁ −1)×n ₁ ) overlapping regions and (m ₁ ×(n ₁ ) 1)) forming the second overlapping regions on the substrate;
the second mark in the (m ₁ ×m ₂ ) row (n ₁ ×n ₂ ) column;
m ₃ of the third marks and m ₃ of the fourth marks in each of the first overlapping regions;
m ₄ of the fifth marks and m ₄ of the sixth marks in each of the second overlapping regions
is formed on the substrate,
The third process is
The first deviation with respect to each of the (m ₁ ×m ₂ ×n ₁ ×n ₂ ) overlapping marks formed on the substrate by the first mark formed in the first step and the second mark formed in the second step save the sheep,
The second deviation amount for each of the (m ₃ ×(m ₁ −1) × n ₁ ) overlapping marks formed by the third mark and the fourth mark formed in the first overlapping region by the second step to save
The third misalignment amount for each of the (m ₄ × m ₁ ×(n ₁ −1)) overlapping marks formed by the fifth mark and the sixth mark formed in the second overlapping region by the second step to save,
A measurement method, characterized in that. 3. The method of claim 2,
The center point of a straight line connecting the center positions of the m ₃ 3rd marks and the center positions of the m ₃ 4th marks overlaps the center positions of the m ₂ ×n ₂ 2nd marks, the 3rd mark and the fourth mark is disposed. 3. The method of claim 2,
The center point of a straight line connecting the center positions of m ₄ of the fifth marks and the center positions of m ₄ of the sixth marks overlaps with the center positions of m ₂ × n ₂ of the second marks, the fifth mark and the sixth mark is disposed. 3. The method of claim 2,
The third mark and the fifth mark are marks of the same pattern, and the fourth mark and the sixth mark are marks of the same pattern. According to claim 1,
The said 1st mark, the said 2nd mark, the said 3rd mark, the said 4th mark, the said 5th mark, and the said 6th mark are arrange|positioned in the same mask, The measurement method characterized by the above-mentioned. According to claim 1,
The first mark is disposed on a first mask, and the second mark, the third mark, the fourth mark, the fifth mark and the sixth mark are disposed on a second mask different from the first mask A measurement method, characterized in that According to claim 1,
wherein the second mark has a pattern transferred within the frame of the first mark. According to claim 1,
The third mark has a pattern transferred within the frame of the fourth mark. According to claim 1,
The fifth mark has a pattern transferred within the frame of the sixth mark. According to claim 1,
The third mark, the fourth mark, the fifth mark, and the sixth mark are substituted for the second mark. A measurement device having a processing unit that measures distortion representing distortion of an image projected on a substrate through a projection optical system,
The processing unit,
Shot exposure for transferring to the substrate a first pattern having a plurality of first marks arranged at predetermined intervals in the row and column directions arranged on the object plane of the projection optical system on the substrate, overlap with adjacent shots does not occur a first process of forming a plurality of the first patterns in the row direction and the column direction by performing a plurality of times while shifting them in the row direction and the column direction, respectively;
a second pattern having a plurality of second marks arranged at the predetermined intervals in the row direction and the column direction, respectively, disposed on the object plane, and a plurality of peripheral marks positioned around the plurality of second marks; forming a plurality of the second patterns in the row direction and the column direction by performing the shot exposure transferred to the substrate a plurality of times while shifting each in the row direction and the column direction so that partial regions of adjacent shots overlap a second processing;
a third process for obtaining the distortion is performed based on the amount of deviation between the first mark and the second mark transferred to the substrate and the amount of deviation between the peripheral marks in the partial region;
wherein the plurality of peripheral marks include a third mark, a fourth mark, a fifth mark, and a sixth mark, respectively disposed at different positions around the plurality of second marks;
In the second process, the third mark and the fourth mark are formed in a first overlapping area in which a portion of two shots adjacent in a column direction among the partial areas overlap in a row direction forming a plurality of the second patterns in the row direction and the column direction so that the fifth mark and the sixth mark are formed in a second overlapping area where a portion of the two shots overlap;
The third process includes a first shift amount that is a shift amount between the first mark formed on the substrate in the first process and the second mark formed on the substrate in the second process, and the first offset by the second process. A second shift amount that is a shift amount between the third mark and the fourth mark formed in the overlapping region, and a third shift amount that is a shift amount between the fifth mark and the sixth mark formed in the second overlap region by the second process Based on , to obtain the distortion
A measurement device, characterized in that. An exposure apparatus for exposing a substrate through a projection optical system,
a stage for holding the substrate;
The measuring device according to claim 12, which measures the distortion of the projection optical system by projecting a pattern of a mask onto a substrate held by the stage through the projection optical system;
A control unit for controlling an exposure process for exposing the substrate so as to reduce the distortion measured by the measuring device
It is characterized in that it has, the exposure apparatus. An article manufacturing method for manufacturing an article,
exposing the substrate using an exposure apparatus;
developing the exposed substrate;
a process for making the article from the developed substrate
including,
The exposure apparatus,
An exposure apparatus for exposing a substrate through a projection optical system,
a stage for holding the substrate;
a measuring device for measuring distortion of the projection optical system by projecting a pattern of a mask onto a substrate held by the stage through the projection optical system;
A control unit for controlling an exposure process for exposing the substrate so as to reduce the distortion measured by the measuring device
including,
The measuring device is a measuring device having a processing unit that measures distortion representing distortion of an image projected on a substrate through the projection optical system;
The processing unit,
Shot exposure for transferring to the substrate a first pattern having a plurality of first marks arranged at predetermined intervals in the row and column directions arranged on the object plane of the projection optical system on the substrate, overlap with adjacent shots does not occur a first process of forming a plurality of the first patterns in the row direction and the column direction by performing a plurality of times while shifting them in the row direction and the column direction, respectively;
a second pattern having a plurality of second marks arranged at the predetermined intervals in the row direction and the column direction, respectively, disposed on the object plane, and a plurality of peripheral marks positioned around the plurality of second marks; forming a plurality of the second patterns in the row direction and the column direction by performing the shot exposure transferred to the substrate a plurality of times while shifting each in the row direction and the column direction so that partial regions of adjacent shots overlap a second processing;
a third process for obtaining the distortion is performed based on the amount of deviation between the first mark and the second mark transferred to the substrate and the amount of deviation between the peripheral marks in the partial region;
wherein the plurality of peripheral marks include a third mark, a fourth mark, a fifth mark, and a sixth mark, respectively disposed at different positions around the plurality of second marks;
In the second process, the third mark and the fourth mark are formed in a first overlapping area in which a portion of two shots adjacent in a column direction among the partial areas overlap in a row direction forming a plurality of the second patterns in the row direction and the column direction so that the fifth mark and the sixth mark are formed in a second overlapping area where a portion of the two shots overlap;
The third process includes a first shift amount that is a shift amount between the first mark formed on the substrate in the first process and the second mark formed on the substrate in the second process, and the first offset by the second process. A second shift amount that is a shift amount between the third mark and the fourth mark formed in the overlapping region, and a third shift amount that is a shift amount between the fifth mark and the sixth mark formed in the second overlap region by the second process Based on , to obtain the distortion
A method of manufacturing an article, characterized in that delete

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