JPH10288567A - Photomask and coma-aberration measuring method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely measure the aberration of a lens by utilizing that the light intensity of sub-peak is differed between the areas opposed with a main pattern as the center according to lens aberration. SOLUTION: While the transmitted light of the main pattern 3 of a light transmitting part is a positive code, the phase of the transmitted light of a translucent phase shift membrane 2 is reversed and a negative code. In addition to a light intensity 4 transmitted by the main pattern 3, a second light intensity peak 5 or a so-called sub-peak is generated. Although the exposure of a resist is generally set so that the sub-peak is not transferred, the sub-peak is transferred to the resist on a wafer to evaluate the aberration of a lens in this invention. When the lens has no aberration the second light intensity peak 5 is generated with the same light intensity around the main pattern peak 4, and when the lens has a coma aberration, the light intensity is differed between sub-peaks 7, 8 opposed with the main pattern peak 6 as the center. The lens aberration is quantitatively determined by use of this phenomenon, whereby a precise aberration evaluation is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus used for manufacturing semiconductor devices and the like, and more particularly, to a method for evaluating a lens of a reduction projection exposure apparatus and a photomask used for the evaluation.

[0002]

2. Description of the Related Art In a lithography process for manufacturing a semiconductor device or the like, a reduced projection exposure apparatus is mainly used.
The miniaturization of semiconductor devices has been achieved by improving the performance of reduction projection exposure apparatuses. However, in order to further refine the pattern, it is necessary to reduce the aberration of the reduction projection lens. Conventionally, the aberration of a lens mounted in a reduction projection exposure apparatus has been evaluated using information obtained from the shape of a formed resist pattern. FIG. 9 shows an example of a change in the resist cross-sectional shape depending on the presence or absence of coma of the lens. When there is no aberration, as shown in FIG.
In contrast, when there is an aberration, the inclination angles of both side surfaces of the resist pattern 92 are different, as shown in FIG. The slope angle of the side is gentle. Normally, an evaluation is made empirically using the difference between the inclination angles on both sides or the difference between the inclination widths 93 and 94. However, in this evaluation method, the obtained value differs depending on the reflectance of the substrate, the resist film thickness, and the characteristics of the resist, and the amount of aberration cannot be measured accurately.

[0003]

In order to reduce the aberration of the lens, various kinds of aberration of the lens are measured with high accuracy, and corrected,
It is necessary to select. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem and to provide a means for accurately measuring the amount of aberration of a lens mounted on a reduction projection exposure apparatus.

[0004]

In order to achieve the above object, according to the present invention, a second light intensity peak which is generated when a pattern is formed using a translucent phase shift mask, that is, a light intensity of a so-called sub-peak is determined by a lens. The lens aberration is quantitatively obtained by utilizing the fact that the difference occurs in the region facing the main pattern as the center depending on the aberration amount.

[0005] Further, by arranging the measurement pattern over the entire surface of the mask, the lens aberration in the exposed area can be evaluated by one-shot exposure.

Further, by arranging a light-shielding pattern, it is possible to perform exposure at a fine pitch, and it is possible to reduce the influence of variations in resist coating in a wafer, the effect of a substrate, and the like, for evaluation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of the present invention will be described with reference to FIG.
FIG. 1A is a plan view of a translucent phase shift mask,
FIG. 1B is a cross-sectional view of the translucent phase shift mask.
1 is a glass substrate, 2 is a translucent phase shift film, and 3 is a main pattern formed in a transparent region. Translucent phase shift film 2
Used a CrON film. Further, the translucent phase shift film 2
Was 6% for the exposure light. Here, the CrON film is used as the translucent film, but the invention is not limited to this. Cr
It is sufficient that the phase of light passing through the translucent portion and the transparent portion is almost inverted, such as a multilayer film of a transparent film such as O, CrN, MoSiO, MoSiON, or SiO2. Structure is good. As shown in FIG. 1 (c), the amplitude distribution of the light passing through the mask is such that the light passing through the main pattern 3, which is the light transmitting portion, has a positive sign, while the light passing through the translucent phase shift film 2 has a positive sign. The phase of the transmitted light is inverted and has a negative sign. When this light is projected on the wafer through a lens, the phase is inverted at the boundary between the main pattern 3 which is a light transmitting portion and the translucent phase shift film 2 as shown in FIG. The light intensity becomes almost zero. Therefore, the spread of light intensity is suppressed, and a fine pattern with high contrast can be formed. However, in addition to the light intensity 4 passing through the main pattern 3, a second light intensity peak 5 or a so-called sub-peak occurs. Usually, when this mask is used, the exposure amount of the resist is set so that the second light intensity peak is not transferred. In the present invention, the sub-peak which is not normally transferred to the wafer is transferred to the resist on the wafer,
Evaluate the lens aberration.

FIG. 10 shows a main configuration example of a reduction projection exposure apparatus for projecting a pattern on a resist. The light emitted from the light source 101 is a fly-eye lens 102, a condenser lens 1
The mask 106 is irradiated via the mirrors 03 and 105 and the mirror 104. In some cases, the mask 106 is provided with a pellicle 107 for preventing pattern transfer failure due to foreign matter adhesion. The mask pattern drawn on the mask 106 is projected via a projection lens 108 onto a wafer 109 as a sample substrate. The mask 106 is placed on a mask stage 118 controlled by the mask position control means 117, and the center of the mask 106 and the optical axis of the projection lens 108 are accurately aligned. The wafer 109 is vacuum-adsorbed on the sample stage 110. The sample stage 110 is mounted on a Z stage 111 movable in the optical axis direction of the projection lens 108, that is, in the Z direction.
12 is mounted. Since the Z stage 111 and the XY stage 112 are driven by the respective driving units 113 and 114 in accordance with a control command from the main control system 119, they can be moved to desired exposure positions. The position is accurately monitored by the laser length measuring device 115 as the position of the mirror 116 fixed to the Z stage 111. The projection lens 108 has various aberrations. However, at present, there is no method for accurately measuring the aberration of the projection lens mounted on the reduction projection exposure apparatus, which is a problem. Mask 1
06, using a translucent phase shift mask,
When the pattern is transferred to the resist on the lens 9, this lens 10
Due to the aberration of 8, the above-mentioned second light intensity peak 5 changes. FIGS. 1D and 1E are examples. FIG.
(D) is a light intensity distribution when there is no lens aberration.
The second light intensity peak 5 occurs at the same light intensity around the main pattern. FIG. 1E shows a light intensity distribution when the lens has a coma aberration. There is a difference between the light intensities of the sub-peaks 7 and 8 facing each other around the main pattern. In the present invention, using this phenomenon, the lens aberration is quantified, and the aberration is evaluated with high accuracy.

A first embodiment of the present invention will be described with reference to FIGS. 2 to 5 and FIGS. FIG. 2 shows the relationship between the coma aberration, one of the lens aberrations, and the light intensity of the second light intensity peaks 7 and 8 of the light intensity distribution shown in FIG. Here, for the pattern transfer, a stepper having an exposure wavelength λ = 0.248 μm and a numerical aperture NA of the lens = 0.55 was used. The transmittance of the translucent film is 6 when the transmittance of the transparent portion is 100%.
%, The phase difference between the transparent portion and the translucent portion is 180 °, and the design dimension W of the light transmitting portion corresponding to the main pattern 3 to be transferred is 0.40 μm square (since the magnification of the projection exposure optical system is １ ／, the A 2 μm square mask was used. The light intensity at the second light intensity peak 7 increases substantially in proportion to the increase in the amount of coma. On the other hand, the light intensity of the second light intensity peak 8 located at a position facing the center of the main pattern decreases as the coma aberration amount increases.

FIG. 3 shows the ratio of the light intensity of the second light intensity peak 8 to the light intensity of the second light intensity peak 7. It can be seen that the light intensity ratio increases in proportion to the coma. Therefore,
By obtaining the exposure ratio at which the second light intensity peaks 7 and 8 are respectively transferred, the coma aberration can be obtained using FIG.

FIGS. 4 and 12 show the cross-sectional shape and the planar shape of the resist pattern actually tested. A resist 10 is applied on a substrate 9 as shown in FIG. 4A and exposed and developed in a usual process to form a mask pattern on the resist. Here, what differs from the related art is that the amount of exposure is adjusted so that the second light intensity peaks 7 and 8 are transferred to the resist when a pattern is formed. As shown in FIG. 4B, a pattern 11 formed by light passing through the main pattern
In addition, an exposure amount E1 at which the resist starts to be reduced in film thickness is determined by the second light intensity peak 7. Under this condition, the second light intensity peak 8 is not transferred to the position 12 facing the pattern 11 as a center. Next, as shown in FIG. 4C, an exposure amount E2 at which the resist starts to be reduced in thickness at the position 12 facing the resist film reduced portion 14 with the pattern 11 as a center is determined by the second light intensity peak 8. The coma aberration amount can be obtained by converting the exposure amount ratio between the exposure amount E2 and the exposure amount E1 into the light intensity ratio of the sub-peak and applying the result to FIG. The actual measurement result is E1 = 7
It was 6.8 mJ / cm2 and E2 was 48.0 mJ / cm2. The light intensity ratio in this case is E2 / E1 =
76.8 / 48.0 = 1.6, and the coma aberration amount was about 0.11 × λ. Alternatively, a method may be used in which the second light intensity peaks 7 and 8 are simultaneously transferred to the resist, and the reduced amount of each resist film is converted into light intensity using a sensitivity characteristic curve of the resist.

The main pattern is not limited to a square, but may be a polygon such as a hexagon or an octagon. By using a polygon pattern, the direction of coma aberration can be measured simultaneously with the amount of coma aberration. FIG. 11 is a plan view of a mask when an octagonal pattern is used. Reference numeral 122 denotes a translucent phase shift area, and 123 denotes a main pattern formed of a transparent area. Here, the design dimension W of one side of the main pattern 123 is not particularly limited, but W = a · λ / NA (however, the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ, and a ≧ 0.4). It is desirable to set conditions. Here, for pattern transfer, the exposure wavelength λ = 0.248 μm and the numerical aperture NA of the lens = 0.55
Stepper was used. The transmissivity of the translucent film is 6% when the transmissivity of the transparent portion is 100%, the phase difference between the transparent portion and the translucent portion is 180 °, one side design dimension of the light transmitting portion of the main pattern 123 to be transferred. A mask having a W of 0.50 μm (2.5 μm square on the mask because the magnification of the projection exposure optical system is ５) was used. FIG. 12 shows the plan shape of the resist pattern actually tested. As shown in the figure, exposure and development are performed in a normal process to form a mask pattern on a resist. Here, the difference from the related art is that the amount of exposure is adjusted so that the second light intensity peak is transferred to the resist when a pattern is formed. As shown in FIG. 12A, in addition to the pattern 131 formed by the light that has passed through the main pattern, an exposure amount E1 at which the resist starts to be reduced in thickness by the second light intensity peak is obtained. Under this condition, the second light intensity peak is not transferred to 132, which is a position facing the pattern 131 as a center. Next, as shown in FIG. 12B, an exposure amount E2 at which the resist starts to be reduced by the second light intensity peak is obtained at a position 132 facing the resist reduced portion 134 with the pattern 131 as a center. This exposure amount E2
The coma aberration amount can be obtained by converting the exposure amount ratio of the exposure amount E1 to the light intensity ratio of the sub-peak and comparing the calculated value with the calculated value. The actual measurement result is E1 = 76.8 mJ
/ Square cm, and E2 = 48.0 mJ / square cm. The light intensity ratio in this case is E2 / E1 = 76.8 /
48.0 = 1.6, and the coma aberration amount is about 0.11 × λ.
Met. In addition, the regular octagon made it possible to determine the direction of coma with high accuracy.

The coma is distributed in the plane of one shot of the reduction projection exposure apparatus. Therefore, it is desirable that the entire surface within a shot can be measured at once. FIG. 5 shows an arrangement in which a measurement pattern is arranged in an effective exposure area of a mask for measuring the amount of coma aberration of a lens. FIG. 5A is a plan view of the mask, and FIG. 5B is an enlarged view of one of the evaluation patterns. Reference numeral 52 denotes a translucent phase shift area, which is arranged in an effective exposure area of the mask. Reference numeral 53 denotes a main pattern formed of a transparent area, and reference numeral 56 denotes an area outside the effective exposure area of the mask. Here, the design dimension W of the main pattern 3 is not particularly limited, but under the condition of W = a · λ / NA (where the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ, and a ≧ 0.4). It is desirable to do. Here, the pattern is a 0.40 μm square pattern. A stepper having an exposure wavelength λ = 0.248 μm and a numerical aperture NA of the lens = 0.55 was used. A photomask having a transmittance of 6% in the translucent portion of the mask and a phase difference of 180 ° between the transparent portion and the translucent portion was used. If the arrangement pitch P of the main pattern is less than 0.78 μm, the accuracy of measurement is reduced due to the influence of the adjacent pattern. Therefore, the arrangement pitch of the main pattern is set to 0.78 μm or more. Arrangement pitch P of main pattern
Is represented by P = b · λ / NA. Here, the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ, and b ≧ 1.72. Using this mask, the amount of coma aberration on the entire surface of the lens could be measured. In addition, the pattern is transferred to the wafer by changing the exposure time in a step-and-repeat manner, and the presence or absence of the transfer of the sub-peak pattern is recognized as a pattern defect using a normal pattern defect inspection apparatus, so that the exposure amount of the sub-peak transfer is reduced. As a result, the sub-peak light intensity ratio could be efficiently obtained. Note that the pattern defect inspection apparatus compares a transfer shape between a reference pattern and an inspection pattern and recognizes a portion different from the reference pattern as a defect.

A second embodiment will be described with reference to FIG. First
In Example 1, the substrate was moved in substantially the same step as the exposure area of one shot, and the exposure was repeated while changing the exposure amount, and the symmetry of the second light intensity was evaluated. In this case, an error in the film thickness of the substrate or the resist as the material to be processed, an error in the focal position caused by the apparatus, and the like cause a decrease in measurement accuracy. However, if the substrate moving step is smaller than the exposure shot size, the translucent portion is double-exposed, so that the intensity ratio of the light intensity peak cannot be obtained accurately.

The second embodiment relates to a mask structure and an exposure method for avoiding double exposure. FIG. 6 shows the pattern arrangement of the mask. In order to move the substrate at a pitch that is ultimately smaller than the exposure shot size and perform exposure,
An r film was placed. FIG. 6A is a plan view of the pattern,
FIG. 6B is an enlarged view of the pattern. 62 is a translucent phase shift section, 63 is a transparent section, and 64 is a light shielding section. Exposure conditions, transmittance of the translucent portion, phase difference, and the like are the same as in the first embodiment. This mask structure is a structure in which a light-shielding portion is formed around a translucent portion. Even if a pattern is transferred by step-and-repeat in very small steps, double exposure is not performed. However, preferably, the width of the translucent portion between the transparent portion 63 and the light shielding portion 64 needs to be ≧ 0.4 μm. If the width of the translucent portion is <0.4 μm, the sub-peak may not be transferred due to the effect of the light-shielding pattern, and the measurement accuracy is reduced. When the transfer optical systems are different, the arrangement position W1 of the light-shielding pattern is represented by W1 = c · λ / NA. However, the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ,
c ≧ 0.89. Further, the pitch of the step and repeat needs to be a step larger than the size of the translucent portion so that the translucent portion is not subjected to multiple exposure. The mask pattern arrangement can be applied to any arrangement other than that shown in FIG. 6 as long as it can prevent multiple exposure. For example,
As shown in FIG. 7, a structure in which the light shielding portion is arranged in the step and repeat direction may be adopted. 72 is a translucent phase shift section, 73 is a transparent section, and 74 is a light shielding section. By setting the width W1 of the translucent portion to 0.4 μm or more, the light shielding portion 74 is formed.
The second light intensity peak value is obtained without being affected by the above, and the present invention can be applied. The width W1 of the translucent portion is W
1 = c · λ / NA. Here, the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ, and c ≧ 0.89. The light-shielding pattern 74 is disposed at a position facing at least the direction of the exposure step with the main pattern 73 as a center. The dimension W2 of one side of the light shielding pattern 74 needs to be set according to the number of steps and repeats and the pitch. The dimension W2 of one side of the light shielding pattern 74 is W2 = d · λ
/ NA. Here, the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ, and d ≧ 2.66.

Using this mask, the aberration of the projection lens was measured. The exposure step was determined so that the translucent portions did not overlap twice. FIG. 8 shows a sectional view and a plan view of the pattern formed on the resist. Here, 85 is a substrate, 86 is a resist, 81, 82, 83 and 84 are patterns to which the transparent pattern 3 has been transferred, and 81, 82, 83 and 84 are portions where the resist is reduced in film thickness by the second light intensity 7. , 81, 8
Reference numerals 2, 83 and 84 denote portions where the resist is reduced in film thickness by the second light intensity 8. Exposure is exposure step 1,
Step exposure was performed while increasing the exposure amount in the order of 2, 3, and 4. The sub-peak 82 began to be transferred to the left of the main pattern 82 in the exposure step 2, and the sub-peak was transferred to the right of the main pattern 84 in the exposure step 4. As a result of an actual experiment, the exposure amount in the exposure step 2 and the exposure amount step 4 was set to 48.0 mJ in the exposure step E1.
/ Square cm, and the exposure amount E2 = 7 in the exposure amount step 4
It was 6.8 mJ / square cm. Therefore, the light intensity ratio is E1 / E2 = 76.8 / 48.0 = 1.6.
When the coma aberration amount is obtained from this value using FIG. 3, it is easily understood that the coma aberration amount is about 0.11 × λ. Also,
Since the exposure step was reduced by arranging the light-shielding pattern, variations in the resist film thickness and the influence of the substrate were reduced, so that quantitative coma aberration could be evaluated with high accuracy. Further, even when the main pattern was changed to a polygon and a circle, the same effect as in the first embodiment was obtained.

Although the dimensions and coefficients of the main pattern and the light-shielding pattern are limited as described above, the optimal values of the size and shape of the main pattern and the light-shielding pattern differ depending on the transmittance of the translucent region. For example, when the transmittance changes, the light intensity passing through the translucent region changes. For example, when the transmittance is changed to 4%, the light intensity passing through the translucent region becomes small. As a result, the main pattern size, the light shielding pattern arrangement position, and the like are changed. However, if each is optimized, the lens aberration measurement can be performed with almost no problem. Therefore, it is necessary to optimize the light shielding pattern position and the like in accordance with the transmittance of the translucent region and the main pattern. The shapes of the main pattern and the light-shielding pattern are not limited to rectangles and hole patterns. It is applicable when sub-peaks such as a line pattern, a cross-shaped pattern, a polygonal pattern such as a hexagon and an octagon, and a circular pattern are generated around the main pattern. However, the hole patterns shown in this embodiment can be evaluated regardless of the direction of the aberration of the lens, and are practical. The transmissivity of the translucent region is not limited to this embodiment, but can be applied by using a coefficient suitable for the transmissivity. Although the light-shielding region is provided with the light-shielding film, it is not limited to this. 0 light intensity on wafer
Any method such as a method of arranging transparent patterns having a resolution equal to or less than the resolution limit at a predetermined pitch can be used. However, since the formation of the mask is simple, it is practical to arrange a light-shielding film as shown in this embodiment. Further, the structure and material of the mask are not limited to the materials used in this embodiment. That is, in the present invention, the structure of the mask used includes a transparent region, a translucent region, and a light-shielding region, and the phase difference between light passing through the transparent region and the translucent region is 180 °, and the periphery of the main pattern to be projected is If the pattern is arranged so that the second light intensity is transferred, the object can be achieved. Further, when the lens was selected and corrected in the reduction projection exposure apparatus using the present measurement method, the individual difference of the lens could be reduced to half of the conventional one. Further, as a result of forming a pattern of an VLSI using a reduced projection exposure apparatus in which a lens was selected using this measurement method,
The displacement of the pattern due to the coma of the lens is reduced by 1 /
3, and as a result, a higher density pattern arrangement was realized. Further, the defect rate of the VLSI product was reduced to 2/3.

[0018]

According to the present invention, various aberrations of a lens mounted on a reduction projection exposure apparatus can be measured with high accuracy. Thereby, the lens can be corrected and selected, and the individual difference of the lens can be made smaller than before. In particular, the pattern displacement due to the coma aberration of the lens can be reduced as compared with the related art, and as a result, a higher-density pattern arrangement can be realized, and the manufacture of the VLSI can be realized using optical lithography. Further, the defect rate of the VLSI product can be reduced, which is industrially advantageous.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention.

FIG. 2 is an explanatory diagram of the principle of the present invention.

FIG. 3 is an explanatory diagram of the principle of the present invention.

FIG. 4 is an explanatory diagram of a main embodiment of the present invention.

FIG. 5 is a plan view of a main embodiment of the present invention.

FIG. 6 is a plan view of a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a second embodiment of the present invention.

FIG. 8 is an explanatory view of a second embodiment of the present invention.

FIG. 9 is an explanatory diagram of a conventional technique.

FIG. 10 is an explanatory diagram of the principle of the present invention.

FIG. 11 is an explanatory view of a main embodiment of the present invention.

FIG. 12 is an explanatory diagram of a main embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2, 52, 62, 72, 122 ... Translucent phase shift film, 3, 53, 63, 73, 123 ... Transparent main pattern, 4 ... Light intensity peak of transparent main pattern, 5 ... Transparent main pattern , A light intensity peak of the transparent main pattern when there is a coma of the lens, a first subpeak when there is a coma of the lens, a second subpeak when there is a coma of the lens , 9, 85, 90 ... substrate, 10, 86, 13 ... resist, 11, 81, 8
2, 83, 84, 131: pattern transferred with a transparent main pattern, 12, 81, 82, 83, 84, 132: reduced portion of resist film due to second light intensity peak, so-called sub-peak 8.
14, 81, 82, 83, 84, 134... A resist film reduced portion due to a second light intensity peak, so-called sub-peak 7, 5
6, 76: outside the effective exposure area, 64, 74: light shielding pattern,
106: mask, 108: projection lens, 109: wafer.

Claims (20)

[Claims] 1. A photomask including at least a translucent area and a transparent area with respect to exposure light, wherein a phase difference between light passing through the translucent area and the transparent area is approximately 180 °. The pattern transferred by the reduction projection exposure device
Formed at a part of the position corresponding to the translucent area on the mask around the main pattern corresponding to the transparent pattern on the mask,
A lens aberration measurement method characterized by evaluating the amount of aberration of a lens by using the fact that the light intensity of a so-called sub-peak differs in a region facing the main pattern as a center. 2. The method according to claim 1, further comprising an opaque area, a translucent area, and a transparent area with respect to the exposure light, wherein the phase difference between the light passing through the translucent area and the transparent area is approximately 180 °. The light intensity of the so-called sub-peak, which is formed at a part of the pattern transferred by the reduced projection exposure apparatus using the photomask and corresponding to the translucent area on the mask around the main pattern corresponding to the transparent pattern on the mask However, utilizing the fact that it is different in the area facing the main pattern as a center,
A lens aberration measuring method characterized by evaluating an amount of aberration of a lens. 3. The method for measuring lens aberration according to claim 1, wherein the light intensity of the sub-peak is determined from an exposure amount necessary for transferring the sub-peak to the resist. 4. The apparatus according to claim 1, wherein the shape of the main pattern corresponding to the transparent pattern on the mask is a polygon.
3. The method for measuring lens aberration according to claim 2. 5. The shape of a main pattern corresponding to a transparent pattern on the mask is provided for determining the direction of aberration,
3. The method for measuring lens aberration according to claim 1, wherein the lens is octagonal. 6. A shape of a main pattern corresponding to a transparent pattern on the mask is provided for determining a direction of aberration,
3. The method for measuring lens aberration according to claim 1, wherein the lens aberration is a dodecagon. 7. The main pattern corresponding to the transparent pattern on the mask is provided for determining the direction of aberration,
3. The method for measuring lens aberration according to claim 1, wherein the lens aberration is circular. 8. A pattern transferred by the reduction projection exposure apparatus is subjected to a first exposure on a substrate coated with a resist using a photomask on which a plurality of lens aberration measurement patterns are arranged. 3. The method for measuring lens aberration according to claim 2, wherein the step of performing the second exposure after moving the substrate at a pitch smaller than the distance is performed in a plurality of steps. 9. A photomask used for forming the pattern,
At least the periphery of the transparent main pattern consists of translucent parts,
A light-shielding region is arranged at least in the moving direction and the reverse direction of the substrate around the translucent portion, and the width of the translucent region between the transparent main pattern and the light-shielding region is adjusted to be equal to or less than １ ／ of the moving distance of the substrate. The method for measuring lens aberration according to claim 8, wherein: 10. A photomask used for forming the pattern, wherein at least a periphery of the transparent main pattern is formed of a translucent portion, and a light-shielding region is arranged at least in the direction of movement of the substrate and in the opposite direction around the translucent portion. The width W1 of the translucent region between the transparent main pattern and the light-shielding region is W1 = c · λ / NA (where the numerical aperture of the projection exposure optical system is NA, the exposure wavelength is λ,
9. The method for measuring lens aberration according to claim 8, wherein c ≧ 0.89). 11. A method comprising: at least an opaque area, a translucent area, and a transparent area with respect to exposure light, such that a phase difference between light passing through the translucent area and the transparent area is approximately 180 °. In the photomask, at least the periphery of the transparent main pattern is composed of a translucent portion, and a light-shielding region is arranged in a linear direction centered on at least the main pattern around the translucent portion. A mask for measuring lens aberration, wherein the width of the translucent region is 0.89 × λ / NA or more (where NA is the numerical aperture of the lens and λ is the exposure wavelength). 12. The width W2 of the light-shielding region is W2 = d.lamda. /
11. The method for measuring lens aberration according to claim 9, wherein the numerical aperture of the projection exposure optical system is adjusted to NA, the exposure wavelength is set to λ, and c ≧ 2.66. 13. At least an opaque area, a translucent area, and a transparent area with respect to exposure light, wherein the phase difference between light passing through the translucent area and the transparent area is approximately 180 °. In the photomask described above, at least the periphery of the transparent main pattern is composed of a translucent portion, and the light shielding region is arranged in a linear direction centered on at least the main pattern around the translucent portion, and the width of the light shielding region is 2.66 × A lens aberration measuring mask characterized by being at least λ / NA (where NA is the numerical aperture of the lens and λ is the exposure wavelength). 14. A reduction projection exposure apparatus comprising a lens selected by using the lens aberration measurement method according to claim 1. 15. A step of forming a resist film on a substrate, wherein the reduction projection exposure apparatus includes at least an opaque area, a translucent area, and a transparent area with respect to exposure light, wherein the translucent area and the transparent area are A step of mounting a photomask including a region where the phase difference of light passing therethrough is approximately 180 °,
A step of transferring a pattern of a photomask to a resist by exposure and development processing, and measuring a lens aberration amount using transfer information of a sub-peak pattern generated around a transfer pattern corresponding to a transparent region on the mask. How to measure aberrations. 16. A semiconductor device produced by using a reduction projection exposure apparatus equipped with a lens selected by using the lens aberration measuring method according to claim 1, 2, 3 or 15. 17. The method according to claim 15, wherein the transfer information of the sub-peak pattern is an exposure amount at which the sub-peak pattern is transferred to the resist. 18. The method according to claim 15, wherein the transfer information of the sub-peak pattern is a light intensity obtained from a transfer depth of the sub-peak pattern to the resist. 19. The method according to claim 15, wherein the presence or absence of the transfer of the sub-peak pattern is performed by using a so-called defect inspection apparatus for inspecting the deformation of the pattern and the adhesion of foreign matter by comparing the shape with the reference pattern. How to measure lens aberration. 20. The method for measuring lens aberration according to claim 1, wherein the lens aberration is coma.