KR20180085353A - Estimation method, article manufacturing method, and program - Google Patents

Abstract

The present invention provides a technology which is advantageous to measure distortion of a reference substrate at high accuracy without using an absolute length measuring machine. According to the present invention, an evaluation method for evaluating the reference substrate including a plurality of regions which each have a reference mark, comprises: a preparation process of preparing a reticle which includes a first region and a second region disposed at an outer side of the first region, and in which a first mark for measuring an overlay error is disposed in the first region, and a second mark for measuring a step movement error of a substrate stage is disposed in the second region; an exposure process of performing exposure with respect to each of the plurality of regions of the reference substrate through step movements of the substrate stage by using the reticle; a mark forming process of forming a third mark corresponding to the first mark and a fourth mark corresponding to the second mark on the reference substrate; a first measuring process of measuring an overlay error of the reference mark and the third mark; a second measuring process of detecting the fourth mark formed on the reference substrate to measure the step movement error of the substrate stage; and a determination process of determining a distortion amount of the reference substrate based on the overlay error and the step movement error.

Description

TECHNICAL FIELD [0001] The present invention relates to an evaluation method, an article manufacturing method,

The present invention relates to an evaluation method, an article manufacturing method, and a program.

The correction for suppressing the characteristic difference between a plurality of exposure apparatuses within a predetermined level is called a mix-and-match. The mix-and-match can be accomplished using a reference substrate. However, the reference substrate may have an error due to an exposure apparatus (reference exposure apparatus) selected for manufacturing the substrate and a distortion caused by a process (for example, an etching process). The exposure apparatus corrected using the reference substrate having the distortion is corrected in a state of following the distortion. In addition, when the reference exposure apparatus is changed over time, it is necessary to follow another variation of the reference exposure apparatus with respect to time. It is also difficult to change the exposure apparatus determined as the reference exposure apparatus to another exposure apparatus thereafter.

Thus, in order to manage a plurality of exposure apparatuses using a reference exposure apparatus or a reference substrate that does not depend on a manufacturing process, a method of measuring distortion of a reference substrate and correcting a plurality of exposure apparatuses based on the measurement results is useful .

The absolute side organs can be used to measure the distortion of the reference substrate. However, the absolute side organs are expensive, and the manufacturers that manufacture semiconductor devices rarely own the absolute side organs. Therefore, it is convenient if the distortion of the reference substrate can be measured using an exposure apparatus or an existing overlapping error inspection apparatus or the like.

However, merely measuring the positions of a plurality of marks of the reference substrate by the exposure apparatus or the overlap error inspection apparatus involves the positioning error of the substrate stage in the measurement result, so that the distortion of the reference substrate can be accurately It can not be measured.

Japanese Patent Application Laid-Open No. 2000-299278 discloses an invention relating to correction of straightness and rotation in stage control. However, These do not disclose measuring the distortion of the reference substrate.

The present invention provides an advantageous technique for measuring the distortion of the reference substrate with high precision without using the absolute side organs.

One aspect of the present invention relates to an evaluation method for evaluating a reference substrate having a plurality of regions each having a reference mark, the evaluation method comprising a first region and a second region disposed outside the first region, A preparation step of preparing a reticle in which a first mark for measuring a superposition error is arranged in the first area and a second mark for measuring a step movement error of the substrate stage is arranged in the second area, And an exposure step of performing exposure on each of the plurality of areas of the reference substrate through step movement of the substrate stage using the reticle, A first marking step of measuring a superimposition error between the reference mark and the third mark and a second measurement step of measuring a superposition error of the reference mark and the third mark, A second measuring step of measuring a step movement error of the substrate stage by detecting the fourth mark formed on the quasi substrate, and a determining step of determining a distortion amount of the reference substrate based on the overlap error and the step movement error .

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an execution procedure of a reference substrate evaluation method according to a first embodiment of the present invention. Fig.
2 is a diagram illustrating a reference substrate;
3 is a view illustrating a reticle;
4 is a diagram illustrating a state in which a mark for evaluating a reference substrate is formed on a reference substrate.
Fig. 5 is a view showing part marks of Fig. 4; Fig.
6 is a view showing the procedure for carrying out the evaluation method and the article manufacturing method in the second embodiment of the present invention.
7 is a diagram illustrating a state in which a mark for evaluating an exposure apparatus is formed on a second reference substrate;
Fig. 8 is a diagram showing an executing procedure of an evaluation method and a product manufacturing method according to the third embodiment of the present invention. Fig.
9 is a view showing a schematic configuration of an exposure apparatus;
10 is a diagram showing a configuration of a computer and an evaluation method executed by a computer.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

Fig. 9 shows a schematic structure of the exposure apparatus EX. The exposure apparatus EX exposes the substrate S by illuminating the pattern area of the reticle R with the illumination system 30 and projecting the pattern area onto the substrate S by the projection optical system 40. [ When the substrate S is exposed, a latent image corresponding to the pattern of the pattern area of the reticle R is formed on the photosensitive member on the substrate S. The substrate having the photosensitive material on which the latent image is formed is subjected to development processing to form a physical pattern.

The substrate S is held by a substrate chuck (not shown) of the substrate stage 10. The substrate stage 10 can be supported by the stage base 70. The substrate stage 10 can be driven by the substrate stage driving mechanism 50. The position of the substrate stage 10 can be measured by a position measuring instrument 60 (for example, a laser interferometer, an encoder). The control unit 80 can perform the feedback control of the substrate stage driving mechanism 50 so that the substrate stage 10 is positioned at the target position based on the measurement result of the position measuring instrument 60. [ The reticle R is held by a reticle chuck of the reticle stage 20. When the exposure apparatus EX is configured as a scanning exposure apparatus, the reticle stage 20 can be driven in synchronism with the substrate stage 10 by a reticle stage driving mechanism (not shown).

The exposure apparatus EX may include a scope 90 (measuring instrument) such as an off-axis scope. The scope 90 may include, for example, a camera and an optical system for picking up a mark or the like of the substrate S, and a processor for processing an image picked up by the camera. All or some of the functions executed by the processor may be built in the control unit 80. [ The scope 90 can be used, for example, to measure the position of a mark or the relative position between a plurality of marks. By using the scope 90, the overlap error can be measured.

The control unit 80 may be configured to control the illumination system 30, the projection optical system 40, the substrate stage driving mechanism 50, the position measuring instrument 60, the scope 90, and the like. The control unit 80 can execute processing for evaluating the amount of distortion of the reference substrate. The control unit 80 can execute processing for evaluating the overlap error of the exposure apparatus EX. The control unit 80 includes a PLD (abbreviation of Programmable Logic Device) such as an FPGA (abbreviation of Field Programmable Gate Array) or an ASIC (abbreviation of Application Specific Integrated Circuit) A computer, or a combination of some or all of them. The program 82 may be stored, for example, in a memory medium.

Fig. 1 shows the procedure for executing the evaluation method of the reference substrate in the first embodiment of the present invention. In this evaluation method, the reference substrate 201 and the reticle 301 described below can be used. 2, a reference substrate 201 is illustrated. 3 shows a reticle 301 for evaluating the reference substrate 201 and evaluating the overlapping error of the exposure apparatus EX to be corrected. The reticle for evaluating the reference substrate 201 and the reticle for evaluating the overlapping error of the exposure apparatus EX to be corrected may be separately prepared.

First, the reference substrate 201 will be described with reference to FIG. The reference substrate 201 is formed by applying a light-sensitive material on a material substrate, exposing the light-sensitive material using an arbitrary exposure apparatus (for example, the above-described exposure apparatus EX) For example. The reference substrate 201 has a plurality of regions (shot regions) SR, and each of the regions SR may have one or a plurality of reference marks 202. When the above-described exposure apparatus EX is used to expose the photosensitive material on the material substrate, the material substrate as the substrate S is disposed on the substrate stage 10. [ The substrate stage 10 is positioned by the substrate stage driving mechanism 50 while the position of the substrate stage 10 is measured by the position measuring instrument 60 so that the plurality of regions SR of the material substrate are sequentially Can be exposed. In this case, the position of the reference mark 202 of the manufactured reference substrate 201 is determined by the characteristics of the projection optical system 40 of the exposure apparatus EX, the positioning accuracy of the substrate stage 10, An error according to positioning accuracy and the like may be included.

Next, the reticle 301 will be described with reference to FIG. The reticle 301 has a first region 302 and a second region 306 disposed outside the first region 302. In the first area 302, a first mark 303 for measuring the overlap error is arranged. In the second area 306, a first partial mark 304 and a second partial mark 305 are arranged as a second mark for measuring the step movement error of the substrate stage 10. [ Hereinafter, the first partial mark 304 and the second partial mark 305 are also referred to as the second marks 304 and 305. [ The first region 302 is an area for exposing the region SR of the reference substrate 201 and the second region 306 is a region for exposing the region SR exposed by the first region 302 And is an area for exposing the region SR. The step movement error is generated by sequentially driving the substrate S (substrate stage 10) on the basis of the measurement result by the position measuring instrument 60 in order to sequentially expose a plurality of areas (shot areas) Is a positioning error of the substrate S that occurs when the substrate 50 is moved stepwise by the mechanism 50. The positions of the first mark 303 and the second marks 304 and 305 are guaranteed to meet the tolerance requirement. Alternatively, information indicating the position of the first mark 303, the second mark 304, 305 may be provided together with the reticle 301.

The first mark 303 is formed by a lithography process (a mark formation process to be described later) including a light exposure process and a reference mark 202 of each region SR of the reference substrate 201, And is transferred onto the reference substrate 201 as a third mark so as to form a mark. In other words, a third mark corresponding to the first mark 303 is formed in each region SR of the reference substrate 201 by the lithography process. The first partial mark 304 and the second partial mark 305 as the second marks are respectively formed by a lithography process (a mark formation process to be described later) including a light exposure process as a third partial mark, And transferred onto the substrate 201. Hereinafter, the third partial mark and the fourth partial mark are also referred to as a fourth mark. In other words, a fourth mark corresponding to the second marks 304 and 305 is formed on the reference substrate 201 by the lithography process. Further, a third mark corresponding to the first mark 303 and a fourth mark corresponding to the second mark 304, 305 are formed on the reference substrate 201 by a single lithography process.

Here, the third partial mark corresponding to the first partial mark 304 and the fourth partial mark corresponding to the second partial mark 305 may be a box-like mark for measuring the step movement error of the substrate stage 10 · Construct a box mark. Further, the respective latent images of the third partial marks and the fourth partial marks constituting each box-in-box mark are formed by different exposure processes (i.e., by multiple exposures). The box-in-box mark is, as is well known, a mark in which a box is placed in a box.

Hereinafter, the procedure for performing the evaluation method of the reference substrate 201 in the first embodiment of the present invention will be described with reference to Fig. In step S101 (preparation step), the reticle 301 illustrated in Fig. 3 is prepared. A third mark corresponding to the first mark 303 of the reticle 301 is formed on the reference substrate 201 by using the reticle 301 and the optional exposure apparatus EX in step S102 A fourth mark corresponding to the second marks 304 and 305 of the first mark 301 is formed. As a result, a sample for evaluating the reference substrate 201, that is, a sample on which the third mark and the fourth mark are formed on the reference substrate 201 is formed. Step S102 is an exposure process for exposing each of the plurality of regions SR of the reference substrate 201 through the step movement of the substrate stage 10 of the exposure apparatus EX using the reticle 301 . In the exposure process, in the exposure apparatus EX, the substrate stage 10 is moved stepwise such that another region SR is positioned in the exposure region below the projection optical system 40 after a certain region SR is exposed, The operation in which the other region SR is exposed is repeated until all the regions SR are exposed. Step S102 includes a step of disposing a photosensitive material (photoresist) on the reference substrate 201 before the exposure processing, and a developing step after the exposure step. It is assumed that the shape of the exposure area (shot area) of the exposure apparatus EX used in step S101 is adjusted in advance to a target shape (for example, a rectangle).

Fig. 4 shows four regions SR of the reference substrate 201 after the step S102. In Fig. 4, the region 401 is an area exposed using the reticle 301 in one exposure. In the area SR exposed through the first area 302 of the reticle 301, a reference mark 202 and a box-in-box mark (not shown) composed of a third mark corresponding to the first mark 303 403 are formed. The reference substrate 201 has a region that is multiple exposed through the second region 306 of the reticle 301. In this area, a fourth mark corresponding to the first partial mark 304 as one of the second marks and a fourth mark corresponding to the second partial mark 305 as another one of the second marks, Marks 402 are formed.

In step S103 (first measuring process), the overlapping error Err ₄₀₃ is measured by detecting the reference mark 202 and the box-in-box mark 403 constituted by the third mark corresponding to the first mark 303 do. This measurement may be performed, for example, by using the scope 90 with the reference substrate 201 after development disposed on the substrate stage 10 of the exposure apparatus EX, or by using an inspection apparatus for inspecting the overlap error . The nesting error can be represented by the relative position of the third mark and the reference mark 202 constituting one box-in-box mark 403.

In the step S104 (second measuring process), the fourth mark corresponding to the first partial mark 304 and the box-in-box mark 402 composed of the fourth mark corresponding to the second partial mark 305, The step movement error Err _Step is measured. This measurement may be performed, for example, by using the scope 90 by placing the developed reference substrate on the substrate stage 10 of the exposure apparatus EX, or by using an inspection apparatus for inspecting the overlap error . Step S103 and step S104 may be executed in parallel, or step S103 may be executed after step S104.

In step S105, the distortion amount of the reference substrate 201 is determined based on the overlap error obtained in step S103 and the step movement error obtained in step S104. More specifically, in step S105, the distortion amount of the reference substrate 201 can be determined by subtracting the step movement error obtained in step S104 from the overlap error obtained in step S103.

Hereinafter, the process for obtaining the step movement error Err _Step in step S104 will be described in more detail. First, the box-in-box mark 402 is detected, and the relative position Err ₄₀₂ of the fourth mark corresponding to the first partial mark 304 and the fourth mark corresponding to the second partial mark 305 is Is obtained. Fig. 5 is an excerpt of the box-in-box marks 402 of the multiple exposed areas in the three adjacent areas 401 from which the box-in-box marks 402 Are labeled with reference numerals 501 to 506 in order to distinguish them from each other.

The amount of misalignment in the X-axis direction and the Y-axis direction detected based on the box-in-box mark 501 is (xx1, xy1). Similarly, the amount of misalignment in the X-axis direction and the Y-axis direction detected based on the box-in-box mark 502 is (xx2, xy2). Likewise, the amount of deviation in the X-axis direction and the Y-axis direction detected based on the box-in-box mark 503 is (xx3, xy3). Likewise, the amount of deviation in the X-axis direction and the Y-axis direction detected based on the box-in-box mark 504 is (yx1, yy1). Likewise, the amount of deviation in the X-axis direction and the Y-axis direction detected based on the box-in-box mark 505 is (yx2, yy2). Likewise, the displacement amounts of the detected X-axis direction and Y-axis direction based on the box-in-box mark 506 are (yx3, yy3).

In order to distinguish the three regions 401 from each other, their regions 401 are referred to as regions i, j, and k. Is referred to a position error of the X-axis direction of the area i, the position error in the Y-axis direction, the attitude error (ESx _{i, i} ESy, ESθ _i). Likewise, the positional error in the X-axis direction, the positional error in the Y-axis direction, and the posture error of the region _j are (ESx _j , ESy _j , ES? _J ). Similarly, the positional error in the X-axis direction, the positional error in the Y-axis direction, and the posture error of the region _k are (ESx _k , ESy _k , ESθ _k ). Further, the error caused by a measurement error of the reticle 301 is projected image distortion or the substrate stage 10 of the Δ _xx1, Δ _xx2, Δ _xx3, Δ _xy1, Δ _xy2, Δ _xy3, Δ _yx1, Δ _yx2, It is referred to as Δ _yx3, Δ _{yy1, yy2} Δ, Δ _yy3. Further, the irregular errors when measuring the marks _{ε xx1 (i, j),} ε xx2 (i, j), ε xx3 (i, j), ε xy1 (i, j), ε xy2 (i, j) _{, ε xy3 (i, j)} , ε yx1 (i, j), ε yx2 (i, j), ε yx3 (i, j), ε yy1 (i, j), ε yy2 (i, j), ε _{yy3 (i, j)} . In this definition, the relationship of the formulas (1) to (12) is established.

_{xx 1 (i (i, j} ) = ESx j -ESx i -RyESθ j + RyESθ i + Δ xx1 + ε xx1 (i (i, j) (1)

_{xx 2 (i (i, j} ) = ESx j -ESx i + Δ xx2 + ε xx2 (i (i, j) (2)

_{xx 3 (i (i, j} ) = ESx j -ESx i + RyESθ j -RyESθ i + Δ xx3 + ε xx3 (i (i, j) (3)

_{xy 1 (i (i, j} ) = ESy j -ESy i -RxESθ j -RxESθ i + Δ xy1 + ε xy1 (i (i, j) (4)

_{xy 2 (i (i, j} ) = ESy j -ESy i -RxESθ j -RxESθ i + Δ xy2 + ε xy2 (i (i, j) (5)

_{xy 3 (i (i, j} ) = ESy j -ESy i -RxESθ j -RxESθ i + Δ xy3 + ε xy3 (i (i, j) (6)

_{yx 1 (i, k) =} ESx k -ESx i -RyESθ k -RyESθ i + Δ yx1 + ε yx1 (i, k) (7)

_{yx 2 (i, k) =} ESx k -ESx i -RyESθ k -RyESθ i + Δ yx2 + ε yx2 (i, k) (8)

_{yx 3 (i, k) =} ESx k -ESx i -RyESθ k -RyESθ i + Δ yx3 + ε yx3 (i, k) (9)

_{yy 1 (i, k) =} ESy k -ESy i -RxESθ k + RxESθ i + Δ yy1 + ε yy1 (i, k) (10)

_{yy 2 (i, k) =} ESy k -ESy i + Δ yy2 + ε yy2 (i, k) (11)

yy_{3 (i, k)}= ESy_k-ESy_i+ RxES?_k-RxES?_i+ Δ_yy3+ ε_{yy3 (i, k)} (12)

(7) to (12) are formed for each portion overlapping in the Y direction for each of the portions overlapping in the X direction, the number of overlapping portions in the X direction is Nx, (Nx + Ny) simultaneous equations are generated when the number of nodes is Ny. Since the position error of all the regions 401 and the average value of the posture errors ESx _i , ESy _i , and ES? _I can not be obtained unless they are set to constant values, the three equations (13) through 15) is added.

^{_{Σ i = 1 Ns · ESx i}} = 0 ... (13)

Σ _{i = 1} ^Ns · ESy _i = 0 ... (14)

_{I = 1} ^Ns ES? _I = 0 ... (15)

In addition, (ESx _i, ESy _i, ESθ _i) a does not include the measurement error of the reticle 301 is projected image distortion or the substrate stage 10 of the additional four equations (16) to (19), formula do.

Σ _{i = 1} ^Ns · XiESx _i = 0 ... (16)

? _{I = 1} ^Ns? YiESx _i = 0 ... (17)

Σ _{i = 1} ^Ns · XiESy _i = 0 ... (18)

? _{I = 1} ^Ns? YiESy _i = 0 ... (19)

Here, X _i and Y _i represent the coordinates of the center of each region 401 in the reference substrate 201, and are elements of a vector adjusted such that the sum of all the regions 401 becomes zero.

From the above, 3 (Nx + Ny) + 7 simultaneous equations are constructed.

On the other hand, if the number of area 401 Ns individual, and (ESx _{i, i} ESy, ESθ _i) the unknown of the system of equations, each area 401,

Δ is _{xx1, xx2} Δ, Δ _xx3, Δ _{xy1, xy2} Δ, Δ _{xy3, yx1} Δ, Δ _{yx2, yx3} Δ, Δ _{yy1, yy2} Δ, Δ _yy3. Therefore, there are 3Ns + 12 unknowns in total.

_{ε xx1 (i (i, j} ), ε xx2 (i (i, j), ε xx3 (i (i, j), ε xy1 (i (i, j), ε xy2 (i (i, j), _{ε xy3 (i (i, j} ), ε yx1 (i (i, j), ε yx2 (i (i, j), ε yx3 (i (i, j), ε yy1 (i (i, j), _{Assuming that the} expected value is 0 and the variance is equal to a variable having a probability distribution, it is assumed that the values of _{(i, j)} and _{(y (i, j)} ESx _i , ESy _i , ESθ _i ) is obtained, and it is referred to as a step movement error Err _Step .

Hereinafter, overlapping error Err ₄₀₃ and step movement error in the step S105 Err _Step (i.e., (ESx _i, ESy _i, ESθ _i)), more specifically, a process for determining the distortion Dist _wafer of the reference substrate 201, on the basis of . Here, the shift amount of the reference substrate 201. Box is, boxes, Mark l (coordinate = (x _il, y _il)) in the coordinates of the center of region i (X _i, Y _i), the area i of the (Ex _il , Ey _il ). In addition, the LA coordinates (x _{il, il} y) based on the distortion Dist substrate _{wafer (il} Dx, Dy _il) of 201 in. In this definition, (Dx _il , Dy _il ) is given by equations (20) and (21).

Dx _il = Ex _il -ESx _i -ESθ _i x y _il ... (20)

Dy? _Il = Ey _? -ESy _i -ES? _I x x _il ... (21)

The amount of distortion Dist _wafer of the reference substrate 201 obtained may be maintained in the form of a table for each mark coordinate as it is or may be maintained as a coefficient approximated by a polynomial in a plurality of mark coordinates, .

The calculation in the evaluation method of the reference substrate as described above can be carried out by a computer. The function of the computer may be embedded in the control unit 80 of the exposure apparatus EX, for example. FIG. 10A schematically shows the calculation by the computer 1100. FIG. The computer 1100 executes an operation in accordance with the evaluation program 1102 embedded therein. 10B shows a case where the computer 1100 calculates the distortion amount Dist of the reference substrate 201 based on the measurement results measured by the exposure apparatus EX or the inspection apparatus in the sample formed through the steps S101 and S102 in Fig. _A procedure for obtaining a _wafer is illustrated.

Hereinafter, a method of evaluating the Dist _wafer distortion amount of the reference substrate 201 by the computer 1100 will be described with reference to FIG. 10 (b). In step S1001, the computer 1100 displays the measurement result obtained by the exposure apparatus EX or the inspection apparatus, more specifically, the box-in-box marks 403, 402, respectively. This measurement result includes the measurement result (first information) of the box-in-box mark 403 and the measurement result (second information) of the box-in-box mark 402. The first information includes information indicating the relative position of the reference mark 202 and the third mark corresponding to the first mark 303. [ The second information includes information indicating a relative position of a third partial mark corresponding to the first partial mark 304 and a fourth partial mark corresponding to the second partial mark 305. [

Step S103 '(first step) corresponds to the arithmetic processing in step S103 in Fig. In step S103 '(first step), the computer 1100 obtains the overlapping error Err ₄₀₃ based on the reference mark 202 and the first information. Step S104 '(second step) corresponds to the arithmetic processing in step S104 in Fig. In step S104 ', the computer 1100 obtains a step movement error Err _Step based on the second information.

Step S105 '(third step) corresponds to step S105 in Fig. In step S105 '(third process), the computer 1100 determines the amount of distortion of the reference substrate 201 based on the overlap error obtained in step S103' and the step movement error obtained in step S104 '. More specifically, in step S105 ', the distortion amount Dist _wafer of the reference substrate 201 is determined by subtracting the step movement error obtained in step S104 from the overlap error obtained in step S103'.

Fig. 6 shows the procedure for carrying out the evaluation method and the article manufacturing method according to the second embodiment of the present invention. The second embodiment is carried out after the distortion amount Dist _wafer of the reference substrate 201 is obtained by the implementation of the first embodiment. The second embodiment differs from the first embodiment in that the second reference substrate having the same identity as the reference substrate 201 to be evaluated in the first embodiment is the exposure apparatus EX (to be subjected to the mix-and-match) ). ≪ / RTI > The second reference substrate has the same structure as that of the reference substrate 201 because the second reference substrate has the same in tolerance with respect to the reference substrate 201 illustrated in Fig.

In step S501 (second mark forming step), the fifth mark is formed on the second reference substrate using the exposure apparatus EX to be corrected. Thereby, a sample for evaluating the exposure apparatus EX to be corrected is formed. In step S501, the same reticle as the reticle 301 illustrated in Fig. 3, that is, the reticle 301 for evaluating the reference substrate 201, can be used. However, in step S501, a reticle different from the reticle 301 may be used. When the reticle 301 is used in step S501, the second marks 304 and 305 may be shielded by a masking blade (not shown) so that the second marks 304 and 305 are not transferred to the second reference substrate . When the reticle 301 is used, the fifth mark formed in step S501 is a mark formed by the transfer of the first mark 303 of the reticle 301. [

The step S501 is a step of performing exposure to each of the plurality of shot regions SR of the second reference substrate through a step movement of the substrate stage 10 of the exposure apparatus EX by using a reticle such as the reticle 301 And an exposure process to be performed. In this exposure process, in the exposure apparatus EX to be corrected, the substrate stage 10 (not shown) is positioned such that the other shot region SR is positioned in the exposure region below the projection optical system 40 after a certain shot region SR is exposed Is moved stepwise, and the other shot area is exposed. This operation is repeated until all shot areas are exposed. Step S501 includes a step of disposing a photosensitive material (photoresist) on the second reference substrate before the exposure process, and a developing process after the exposure process.

Fig. 7 shows four shot regions 701 of the second reference substrate after the process S501. In each shot area, a box-in-box mark 702 is formed by a reference mark 202 of the second reference substrate and a fifth mark formed by using the reticle 301. [

In step S502 (the third measuring process), by detecting the box-in-box mark 702, the amount of misalignment Err ₇₀₂ of the fifth mark with respect to the reference mark 202 is measured. This measurement may be performed using the scope 90 by, for example, disposing the developed second reference substrate on the substrate stage 10 of the exposure apparatus EX to be corrected, and performing inspection for checking the overlap error Device. ≪ / RTI > The amount of misalignment can be indicated by the relative positions of the reference mark 202 constituting one box-in-box mark 702 and the fifth mark formed by using the reticle 301. [

In step S503 (correction amount determining step), the amount of misalignment Err ₇₀₂ is corrected based on the distortion amount Dist _wafer of the reference substrate 201 determined in step S105 (evaluation step) of the first embodiment, The correction amount Comp _mm is determined. For example, the center coordinates of the shot areas i (X _i, Y _i), the box, in the shot region i of, boxes, Mark l (coordinate _{= (x il, y il)} ) discrepancy amount Err ₇₀₂ in (E'x _il , E'y _il ). Further, as the coordinates (x _{il, il} y) the amount of distortion Dist _wafer of the reference substrate (201) _(il Dx, Dy _il) according to. Further, as the coordinates (x _{il, il} y) the amount of correction Comp _mm in an exposure apparatus (EX) of the calibration target (Cx _{il, il} Cy) in the. In this definition, (Cx _il , Cy _il ) is given by equations (22) and (23).

Cx _il = E'x _il -Dx _il ... (22)

Cy _il = E'y _il -Dy _il ... (23)

The obtained Comp _mm may hold the value of each mark coordinate as it is in the form of a table, or may hold the value in a plurality of mark coordinates as a coefficient approximated by a polynomial or may be maintained in a different form.

In step S504 (exposure step), the exposure apparatus EX to be corrected is corrected on the basis of the correction amount Comp _mm determined in step S503, the corrected exposure apparatus EX, and the manufacture- do. The correction amount Comp _mm may be, for example, a correction amount for controlling the characteristics of the projection optical system 40, a correction amount for controlling the substrate stage 10, and the like.

Fig. 8 shows the procedure for carrying out the evaluation method and the article manufacturing method according to the third embodiment of the present invention. The third embodiment is carried out after the distortion amount Dist _wafer of the reference substrate 201 is obtained by the implementation of the first embodiment. In the third embodiment, a second reference substrate having the same consistency within the tolerance with respect to the reference substrate 201 to be evaluated in the first embodiment is used as the exposure apparatus EX (to be subjected to the mix-and-match) ). ≪ / RTI > The second reference substrate has the same structure as that of the reference substrate 201 because the second reference substrate has the same in tolerance with respect to the reference substrate 201 illustrated in Fig.

In the step S801 (the second mark forming step), the fifth mark is formed on the second reference substrate having the same consistency with respect to the reference substrate 201 in the exposure apparatus EX to be corrected. Thereby, a sample for evaluating the exposure apparatus EX to be corrected is formed. In step S801, the same reticle as the reticle 301 illustrated in Fig. 3, that is, the reticle 301 for evaluating the reference substrate 201, can be used. However, in step S801, a reticle different from the reticle 301 may be used. When the reticle 301 is used in step S801, the second marks 304 and 305 may be shielded by a masking blade (not shown) so that the second marks 304 and 305 are not transferred to the second reference substrate . When the reticle 301 is used, the fifth mark formed in step S801 is a mark formed by the transfer of the first mark 303 of the reticle 301. [

In step S801, exposure is performed for each of the plurality of shot areas SR of the second reference substrate through the step movement of the substrate stage 10 of the exposure apparatus EX using a reticle such as the reticle 301 And an exposure process to be performed. In this exposure process, in the exposure apparatus EX to be corrected, after a certain shot area SR is exposed, the other shot area SR is positioned in the exposure area below the projection optical system 40 10 are moved stepwise, and the other shot area is exposed. This operation is repeated until all shot areas are exposed. Step S801 includes a step of disposing a photosensitive material (photoresist) on the second reference substrate before the exposure processing, and a developing step after the exposure step. In step S801, the exposure apparatus EX to be corrected is controlled so that a pattern area having a distortion according to the distortion amount Dist _wafer of the reference substrate 201 determined in step S105 (evaluation step) of the first embodiment is transferred onto the second reference substrate. Is adjusted. The control parameter value may be, for example, a control parameter value for controlling the characteristics of the projection optical system 40, a control parameter value for controlling the substrate stage 10, and the like.

In step S802 (third measuring process), the box-in-box mark of the sample formed in step S801 is detected, and the amount of deviation of the fifth mark with respect to the reference mark 202 is measured. This measurement may be performed, for example, by arranging the developed second reference substrate on the substrate stage 10 of the exposure apparatus EX to be corrected and using the scope 90, Device. ≪ / RTI > The amount of misalignment can be indicated by the relative positions of the reference mark 202 constituting one box-in-box mark and the fifth mark formed by using the reticle 301. [

Step S803 (the correction amount determining step) In, the corrected exposure by correcting on the basis of the shift amount measured by the step S802 to the distortion Dist _wafer of the reference substrate 201 determined in the first embodiment of the step S105 (Assessment step) device The correction amount Comp _mm of the projection optical system EX is determined. In step S804 (exposure step), the exposure apparatus EX to be corrected is corrected on the basis of the correction amount Comp _mm determined in step S803, the corrected exposure apparatus EX, and the manufacture- do. The correction amount Comp _mm may be, for example, a correction amount for controlling the characteristics of the projection optical system 40, a correction amount for controlling the substrate stage 10, and the like.

Hereinafter, an article manufacturing method to which the second or third embodiment is applied will be described. The article can be, for example, a semiconductor device or a display device. Semiconductor devices are manufactured by carrying out a preliminary process of forming an integrated circuit on a wafer and a process after the integrated circuit chip on the wafer is completed as a product. The entire process includes a step of exposing a wafer (substrate) coated with a photosensitizer using the above-described exposure apparatus, and a step of developing the wafer. Subsequent processes include assembly processes (dicing and bonding) and packaging processes (encapsulation). The liquid crystal display device is manufactured through a process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate having a transparent conductive film deposited thereon, a step of exposing the glass substrate coated with the photosensitive agent using the above exposure apparatus, and a step of developing the glass substrate do. According to the device manufacturing method of the present embodiment, a device of higher quality than the conventional device can be manufactured.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes may be made within the scope of the present invention.

(Other Embodiments)

The present invention can be implemented by supplying a program or a program for realizing one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and by causing one or more processors in the computer of the system or apparatus to read and execute the program It can also be realized by processing. It can also be realized by a circuit (for example, an ASIC) that realizes one or more functions.

Claims (10)

An evaluation method for evaluating a reference substrate having a plurality of regions each having a reference mark,
A first mark for measuring a superposition error is disposed in the first area, and a second mark for measuring a step movement error of the substrate stage, the second mark having a first area and a second area disposed outside the first area, A preparation step of preparing a reticle arranged in the second region,
And an exposure step of performing exposure on each of the plurality of regions of the reference substrate through step movement of the substrate stage using the reticle, wherein a third mark corresponding to the first mark is formed on the reference substrate, And a fourth mark corresponding to the second mark,
A first measurement step of measuring a superimposition error between the reference mark and the third mark,
A second measuring step of measuring a step movement error of the substrate stage by detecting the fourth mark formed on the reference substrate,
A determination step of determining a distortion amount of the reference substrate based on the overlap error and the step movement error
And an evaluation step of evaluating the evaluation method. The method according to claim 1, wherein the first measuring process and the second measuring process are performed using an exposure apparatus that has performed the exposure process
. The method according to claim 1, wherein the first measurement step and the second measurement step are carried out using an inspection apparatus for inspecting the overlap error
. 2. The method according to claim 1, wherein, in the determining step, the distortion amount is obtained by subtracting the step movement error from the overlapping error
. The apparatus according to claim 1, wherein the second mark includes a first partial mark and a second partial mark, the fourth mark includes a third partial mark corresponding to the first partial mark, And a corresponding fourth partial mark,
The third partial mark and the fourth partial mark are formed so as to overlap with each other by the exposure process to the adjacent regions of the reference substrate
. The exposure apparatus according to claim 1, further comprising a second exposure step of exposing a second reference substrate having an identicality to the reference substrate with respect to the reference substrate in the exposure apparatus to be corrected, A second mark forming step of forming a second mark,
A third measurement step of measuring a displacement amount between the reference mark of the second reference substrate and the fifth mark formed on the second reference substrate,
A correction amount determining step of determining a correction amount by correcting the amount of misalignment obtained in the third measuring step based on a distortion amount of the reference substrate determined in the determining step
And an evaluation step of evaluating the evaluation method. The exposure apparatus according to claim 1, further comprising a second exposure step of exposing a second reference substrate having an identicality to the reference substrate with respect to the reference substrate in the exposure apparatus to be corrected, A second mark forming step of forming a second mark,
And a third measurement step of measuring a displacement amount between the reference mark of the second reference substrate and the fifth mark formed on the second reference substrate,
In the exposure step, the control parameter value of the exposure apparatus to be corrected is adjusted such that a pattern area having a distortion corresponding to the distortion amount of the reference substrate determined in the determination step is transferred to the second reference substrate
. A correction amount determining step of determining a correction amount of the exposure apparatus to be corrected by the evaluation method according to claim 6;
An exposure step of correcting the exposure apparatus to be corrected based on the correction amount and processing the substrate using the corrected exposure apparatus
And an article is manufactured from the substrate subjected to the exposure process. An evaluation step of determining the amount of misalignment by the evaluation method according to claim 7;
An exposure step of correcting the exposure apparatus to be corrected based on the amount of misalignment and processing the substrate using the corrected exposure apparatus
And an article is manufactured from the substrate subjected to the exposure process. There is provided an evaluation program stored in a computer-readable recording medium for causing a computer to execute a process for evaluating a reference substrate having a plurality of regions each having a reference mark,
An acquisition step of acquiring a measurement result of the reference substrate that has been subjected to a lithography process including an exposure process using an exposure apparatus and a reticle;
And a determining step of determining a distortion amount of the reference substrate based on the measurement result,
Wherein the reticle has a first region and a second region disposed outside the first region, a first mark for measuring a superposition error is disposed in the first region, and a step movement error of the substrate stage is measured A second mark for the second area is arranged in the second area,
Wherein the exposure step is a step of performing exposure for each of the plurality of regions of the reference substrate through step movement of the substrate stage and performing, by the lithography step, A third mark and a fourth mark corresponding to the second mark are formed,
Wherein the measurement result includes first information on the reference mark and the third mark and second information on the fourth mark,
The above-
A first step of obtaining an overlapping error between the reference mark and the third mark based on the first information,
A second step of obtaining a step movement error of the substrate stage based on the second information,
A third step of obtaining a distortion amount of the reference substrate based on the overlap error and the step movement error
Containing
And an evaluation program stored in the computer-readable recording medium.

Images