JPH09329742A - Method for correcting aberration of optical system and projecting exposure device provided with aberration correcting optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and accurately execute fine adjustment for the rotational symmetry aberration of an optical system by changing the surface power of one surface of an aberration correcting optical system arranged in a telecentric optical path on the object side or image side of a J optical system. SOLUTION: The aberration correcting optical system 4 is arranged in a telecentric optical path between a lens surface most close to a projecting optical system 3 and an image surface. The aberration of the optical system is corrected by changing the surface power of one surface of the optical system 4. When it is defined that the synthetic power of a partial lens group in the optical system between an iris arranged in the optical system and the optical system 4 is ϕ1 and the synthetic power of the optical system 4 is ϕ2, a conditional relation |ϕ1/ϕ2|>80 is satisfied. Consequently rotational symmetry aberration to be finely adjusted can be corrected while suppressing the aberration not to be corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aberration correction method for an optical system and a projection exposure apparatus equipped with the aberration correction optical system.
In particular, it relates to correction of rotational symmetry aberration of a projection optical system in a projection exposure apparatus for semiconductor manufacturing.

[0002]

2. Description of the Related Art As semiconductor elements such as ultra LSIs are becoming finer year by year, the projection exposure apparatus used in the photolithography process is required to have higher precision. Therefore, in the manufacture of the projection optical system mounted on the projection exposure apparatus for manufacturing a semiconductor, in order to suppress the aberration due to the manufacturing error to a desired amount, each element of the projection optical system is finely adjusted after being assembled once.

At this time, the rotationally symmetric aberration of the projection optical system is finely adjusted by, for example, minutely changing the distance between the lens elements in the optical system or exchanging the lens elements with different powers (refractive powers). ing. However, it is known that fine adjustment of the spherical aberration of the projection optical system can be performed by changing the thickness of the plane-parallel plate. In this case, if the projection optical system is telecentric on the incident side, it is parallel to the optical path between the object plane and the projection optical system, and if it is telecentric on the exit side, it is parallel to the optical path between the projection optical system and the image plane. Insert the face plate.

[0004]

As described above, in the conventional aberration correction method for finely adjusting the rotationally symmetric aberration other than the spherical aberration, the lens interval is mainly finely changed. in this case,
Since the washers having different thicknesses are exchanged to adjust the lens interval, many types of adjusting washers having different thicknesses are required.

Particularly, in fine adjustment of the curvature of field, it is considered necessary to replace with a lens element whose power differs by a small amount. However, in this case, when the lens element is exchanged, the field curvature to be finely adjusted fluctuates, but other aberrations that have already been corrected well (aberrations that are not corrected) also fluctuate. As a result, it becomes necessary to make a minute change in the lens interval again, and the fine adjustment work cannot be performed efficiently. Further, after the projection optical system is mounted on the projection exposure apparatus, it becomes necessary to finely adjust the aberration of the projection optical system in order to optimize it for the installation environment of the apparatus. In this case, the conventional aberration correction method has a disadvantage in that many parts need to be adjusted over a long period of time.

The present invention has been made in view of the above problems, and an aberration correction method and a projection exposure apparatus equipped with the aberration correction optical system capable of finely adjusting the rotationally symmetric aberration of the optical system quickly and accurately. The purpose is to provide.

[0007]

In order to solve the above-mentioned problems, in the present invention, in an aberration correction method for correcting the aberration of an optical system telecentric on at least one of the object side and the image side, The aberration of the optical system is corrected by changing the surface power of at least one surface of the aberration correction optical system arranged in the telecentric optical path on the object side or the image side, and the aperture arranged in the optical system and the aberration. When the combined power of the partial lens group of the optical system with the correction optical system is Φ1 and the combined power of the aberration correction optical system is Φ2, | Φ1 / Φ2 |> 80 must be satisfied. Provided is a characteristic aberration correction method for an optical system.

According to a preferred aspect of the present invention, the aberration of the optical system is corrected by replacing the aberration correction optical system. In the present invention, for example, the field curvature of the optical system can be corrected by changing the synthetic power of the aberration correction optical system. In this case, when the distance from the object plane to the image plane of the synthetic optical system including the aberration correction optical system and the optical system is L and the synthetic power change amount of the aberration correction optical system is ΔΦ2, | L It is preferable that the condition of × ΔΦ2 | <0.4 is satisfied.

According to another aspect of the present invention, an illumination optical system for illuminating a mask on which a predetermined pattern is formed,
In a projection exposure apparatus including a projection optical system for forming a pattern image of the mask on a photosensitive substrate, the projection optical system includes an aperture and a front group disposed between the mask and the aperture. And a rear group disposed between the diaphragm and the substrate, and at least one of the mask side and the substrate side is telecentric, and the mask side of the projection optical system. Alternatively, an aberration correction optical system is provided in the telecentric optical path on the substrate side, and the combined power of the partial lens group of the projection optical system between the diaphragm and the aberration correction optical system in the projection optical system is Φ1. When the combined power of the aberration correction optical system is Φ2, the condition of | Φ1 / Φ2 |> 80 is satisfied, and at least one of the mask-side surface and the substrate-side surface of the aberration correction optical system is satisfied. A projection exposure apparatus, characterized in that the surface power of one surface is changed to correct the aberration of the projection optical system.

[0010]

As described above, according to the present invention, by changing the surface power of at least one surface of the aberration correction optical system arranged in the telecentric optical path on the object side or the image side of the optical system, Corrects rotationally symmetric aberration of the optical system. That is, when the optical system is telecentric on the object side, the aberration correction optical system is arranged in the optical path between the object-side surface of the optical system and the object. When the optical system is telecentric on the image side, an aberration correction optical system is arranged in the optical path between the image side surface of the optical system and the image surface. further,
When the optical system is telecentric on the object side and the image side, at least one of the optical path between the image-side surface of the optical system and the image surface and the optical path between the object-side surface of the optical system and the object. An aberration correction optical system is placed inside.

In the present invention, for example, the original aberration correction optical system may be replaced with another aberration correction optical system in which at least one surface has a different surface power. Further, the surface power of at least one surface of the aberration correction optical system may be changed without replacing the aberration correction optical system. Thus
According to the present invention, it is not necessary to prepare many kinds of adjustment washers as in the prior art, and the rotationally symmetric aberration of the optical system can be finely adjusted quickly and accurately.

In the present invention, the following conditional expression (1) is satisfied. | Φ1 / Φ2 |> 80 (1) Here, Φ1: power of combining partial lens groups of the optical system between the diaphragm arranged in the optical system and the aberration correcting optical system Φ2: combining of the aberration correcting optical system By satisfying the range defined by the upper limit value and the lower limit value of the conditional expression (1), the aberration that is not to be corrected (the aberration that has already been corrected well) without affecting the telecentricity of the optical system. It is possible to satisfactorily correct one or more rotationally symmetric aberrations to be finely adjusted while suppressing the fluctuation of

In the present invention, the field curvature of the optical system can be corrected by changing the synthetic power of the aberration correction optical system. In this case, it is desirable to satisfy the following conditional expression (2). | L × ΔΦ2 | <0.4 (2) where, L: distance from the object plane to the image plane of the combined optical system including the aberration correction optical system and the optical system ΔΦ2: change in combined power of the aberration correction optical system By satisfying the range defined by the upper limit value and the lower limit value of the conditional expression (2), it is possible to satisfactorily correct only the field curvature while suppressing fluctuations of other aberrations. On the contrary, when the conditional expression (2) is not satisfied, the telecentricity of the optical system is affected.

In the present invention, the surface power of the object side surface and the surface power of the image side surface of the aberration correction optical system are changed without changing the combined power of the aberration correction optical system. It is possible to correct coma aberration of the optical system. In this case, it is desirable to satisfy the following conditional expressions (3) and (4). | L × ΔΦ3 | <4 (3) | L × ΔΦ4 | <4 (4) where ΔΦ3: surface power change amount of the object side surface of the aberration correction optical system ΔΦ4: image side surface of the aberration correction optical system Surface power change amount

The surface power MP of the lens surface is expressed by the following equation (a). MP = (n2-n1) / r (a) Here, r: radius of curvature of lens surface n2: medium refractive index after refraction n1: medium refractive index before refraction Conditional expressions (3) and (4) are satisfied. As a result, it is possible to favorably correct only the coma aberration while suppressing fluctuations in other aberrations. On the contrary, when the conditional expressions (3) and (4) are not satisfied, the occurrence of aberrations that are not corrected increases,
It also affects the telecentricity of the optical system.

Further, in the present invention, the optical power is changed by changing the combined power of the aberration correction optical system and by changing the surface power of the object-side surface and the surface power of the image-side surface of the aberration correction optical system. It is possible to correct field curvature and coma of the system. In this case, the above conditional expressions (2) to (4) may be satisfied in order to finely adjust only the field curvature and coma of the optical system without affecting the telecentricity of the optical system. desirable.

Further, according to the present invention, the combined power of the aberration correction optical system is changed, the surface power of the object side surface and the surface power of the image side of the aberration correction optical system are changed, and the aberration correction is performed. By changing the axial thickness of the optical system, it is possible to correct spherical aberration and at least one of field curvature and coma of the optical system. In this case, it is desirable to satisfy the following conditional expression (5). | BF / Δd |> 30 (5) Here, BF: Back focus of the combined optical system including the aberration correction optical system and Δd: Amount of change in axial thickness of the aberration correction optical system

By satisfying the range defined by the upper limit value and the lower limit value of the conditional expression (5), correction of field curvature and spherical aberration, coma aberration and spherical aberration are suppressed while suppressing fluctuations of other aberrations. Can be favorably corrected, or the field curvature, the coma aberration and the spherical aberration can be favorably corrected. On the other hand, if the conditional expression (5) is not satisfied, the aberrations that are not the object of correction increase, which also affects the telecentricity of the optical system.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a main configuration of a projection exposure apparatus having an aberration correction optical system according to each embodiment of the present invention. FIG. 2 is a diagram showing a lens configuration of the projection optical system and the aberration correction optical system in each example. As described above, each embodiment shows an example in which the aberration correction method of the present invention is applied to a projection optical system that is telecentric on the image side. Therefore, in each embodiment, the aberration correction optical system 4 is arranged in the telecentric optical path between the most image-side lens surface of the projection optical system 3 and the image surface.

The projection exposure apparatus of FIG. 1 includes an illumination optical system 1 for illuminating a mask 2 having a predetermined pattern formed thereon with exposure light. The light transmitted through the pattern of the mask 2 forms a pattern image on the wafer 5, which is a photosensitive substrate, via the projection optical system 3 and the aberration correction optical system 4.
Here, the illumination optical system 1 includes a KrF laser as an excimer laser that supplies light having an exposure wavelength of 248.4 nm. The mask 2 is held by a mask stage (not shown), and the wafer 5 as a photosensitive substrate is held by a wafer stage (not shown). As the light source for exposure, not only a KrF laser but also an ArF laser as an excimer laser that supplies light with an exposure wavelength of 193 nm, mercury that supplies light with an exposure wavelength of g-line (436 nm) or i-line (365 nm). A lamp may be used.

In FIG. 2, the diaphragm S constitutes a pupil on the aberration correction optical system side of the projection optical system 3. That is, the projection optical system 3 is composed of a diaphragm S, a front group GF arranged between the mask 2 and the diaphragm S, and a rear group GR arranged between the diaphragm G and the wafer 5. . Here, the front group GF
Is a first lens group G1 having a positive refractive power and a second lens group G having a negative refractive power in order from the object side (mask 2 side).
2, the third lens group G3 having a positive refracting power, and the fourth lens group G4 having a negative refracting power, and the rear group GR has positive refraction in order from the object side (mask 2 side). A fifth lens group G5 having a power and a sixth lens group G6 having a positive refractive power
And

The first lens group G1 is provided on the object side (mask 2
Side), two positive lenses (L11, L12) and a negative meniscus lens L13 having a convex surface facing the image side (substrate 5 side).
And a positive lens L14, and the second lens group G2
Is a front lens L2F that is arranged closest to the object side (mask 2 side) and has a negative refractive power with a concave surface facing the image side (substrate 5 side).
And a rear lens L2R arranged on the most image side (substrate 5 side) and having a negative refractive power with a concave surface facing the object side (mask 2 side).
And an intermediate lens group L2M disposed between the front lens L2F in the second lens group and the rear lens L2R in the second lens group.
It is comprised so that it may have. The intermediate lens group L2M includes, in order from the object side (mask 2 side), a positive lens L21, three negative lenses (L22, L23, L24),
It is composed of a positive lens L25.

The third lens group G3 is composed of four positive lenses (L31, L32, L33, L34), and the fourth lens group G4 is arranged in order from the object side (mask 2 side) toward the image side (mask 2 side). It is composed of a negative lens L41 having a concave surface toward the substrate 5 side) and two negative lenses (L42, L43). The fifth lens group G5 includes, in order from the object side (mask 2 side), a negative lens L51 having a concave surface facing the object side (mask 2 side), three positive lenses (L52, L53, L54), and a negative lens. L55 is composed of three positive lenses (L56, L57, L58) and a negative lens L59 having a concave surface facing the image side (substrate 5 side), and the sixth lens group G6 is on the object side (mask 2 side). In order from, a positive lens L61 having a convex surface facing the object side (mask 2 side) and a thick negative lens L62. The sixth lens group G6
Can also be composed of a single lens.

The following table (1) shows the values of the specifications of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the comparative example. In Table (1), d0 is the axial distance between the mask 2 and the lens surface closest to the mask, and β is the imaging magnification,
NA represents the numerical aperture on the wafer side, and L represents the distance from the object plane of the synthetic optical system to the image plane (that is, the axial distance between the mask 2 and the wafer 5). The leftmost number is the order of the lens surfaces from the mask side, 1 / r is the curvature of each lens surface, d is the distance between the lens surfaces, and n is the refraction to the KrF laser beam (λ = 248.4 nm). Shows the rate. Each lens is made of quartz (SiO ₂ ).

[0025]

[Table 1] d0 = 104.850 β = 1/5 NA = 0.57 L = 1200 Curvature (1 / r) dn 1 1.02270 × 10 ^-3 23.000 1.50839 2 -1.48643 × 10 ^-3 18.112 3 1.26933 × 10 ^-3 24.000 1.50839 4 -3.10683 × 10 ^-3 6.550 5 -3.83799 × 10 ^-3 20.000 1.50839 6 -1.66547 × 10 ^-3 1.000 7 2.92685 × 10 ^-3 27.000 1.50839 8 -1.65798 × 10 ^-3 1.458 9 4.52305 × 10 ^-3 24.000 1.50839 10 8.86 100 × 10 ^-3 25.000 11 4.26389 × 10 ^-3 23.000 1.50839 12 -2.40357 × 10 ^-3 1.000 13 -3.22588 × 10 ^-4 17.000 1.50839 14 8.31529 × 10 ^-3 19.107 15 -1.72920 × 10 ^-3 12.900 1.50839 16 6.93930 × 10 ^-3 28.519 17 -9.18920 × 10 ^-3 15.000 1.50839 18 1.56485 × 10 ^-3 52.304 19 6.06956 × 10 ^-4 35.000 1.50839 20 -5.92997 × 10 ^-3 14.652 21 -8.27367 × 10 ^-3 22.800 1.50839 22 -5.31606 × 10 ^{-3 2.654 23 -3.21943 × 10 -4 27.000} 1.50839 24 -3.36922 × 10 -3 4.072 25 1.42664 × 10 -3 28.000 1.50839 26 -1.48796 × 10 -3 1.307 27 2.78126 × 10 -3 27.000 1.50839 28 -3.28246 × 10 - ⁴ 1.000 29 4.47287 × 10 ^-3 31.000 1.50839 30 -6.499 29 × 10 ^-4 8.386 31 -2 .78019 × 10 ^-4 21.000 1.50839 32 7.03659 × 10 ^-3 8.487 33 5.11892 × 10 ^-3 17.000 1.50839 34 6.32574 × 10 ^-3 34.681 35 -4.77206 × 10 ^-3 15.900 1.50839 36 3.28295 × 10 ^-3 42.000 37 0.0000 14.471 ( Aperture S) 39 -5.71193 × 10 ^-3 18.000 1.50839 40 -8.59404 × 10 ^-4 6.327 41 -1.98742 × 10 ^-3 23.000 1.50839 42 -4.68062 × 10 ^-3 1.092 43 3.12303 × 10 ^-4 23.000 1.50839 44 -2.94899 × 10 ^{-3 3.383 45 2.15591 × 10 -3 40.000} 1.50839 46 -3.07410 × 10 -3 11.393 47 -4.28570 × 10 -3 27.000 1.50839 48 -2.69640 × 10 -3 1.000 49 2.56771 × 10 -3 28.000 1.50839 50 -5.16650 × 10 - ⁴ 4.144 51 5.47938 × 10 ^-3 29.000 1.50839 52 1.88943 × 10 ^-3 3.108 53 7.18271 × 10 ^-3 39.900 1.50839 54 3.17639 × 10 ^-3 9.801 55 2.00685 × 10 ^-3 23.000 1.50839 56 1.23099 × 10 ^-2 6.676 57 1.06409 × 10 ^-2 33.995 1.50839 58 9.83246 × 10 ^-4 2.000 59 1.25289 × 10 ^-3 35.001 1.50839 60 7.95720 × 10 ^-4 19.070 61 0.00000 6.000 1.50839 62 0.00000 BF = 5.900 (Conformance value) Φ1 = 0.00808 Φ2 = 0 (1) ｜ Φ1 / Φ2 ｜ ＝ ∞

FIG. 3 is a diagram showing various aberrations of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the comparative example with respect to the KrF laser light (λ = 248.4 nm). In each aberration diagram, NA indicates the numerical aperture, and Y indicates the image height. In the aberration diagram showing astigmatism, the solid line shows the sagittal image plane and the broken line shows the meridional image plane. As is clear from each aberration diagram, in the comparative example,
It can be seen that the spherical aberration is satisfactorily corrected by the action of the aberration correction optical system 4 including the plane-parallel plate. Further, as shown in Table (1), in the comparative example, the combined power Φ1 of the rear group GR is 0.00808. The combined power Φ2 of the plane-parallel plates (61st and 62nd surfaces) forming the aberration correction optical system 4 is zero. Therefore, in the comparative example, | Φ1 / Φ2 | which is the value of the conditional expression (1) is infinite (∞). In Table (1), the projection optical system has 1 to 60 surfaces.

[First Embodiment] In the first embodiment, in order to correct the field curvature of the projection optical system 3, the plane parallel plate in the comparative example is replaced with a plano-convex lens having a flat surface facing the wafer. . That is, in the first embodiment, the combined power of the aberration correction optical system 4 is changed to the positive side by a small amount. Table (2) below lists values of specifications of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the first example.
However, since the values of the specifications of the projection optical system 3 are the same as those of the comparative example, duplicate description will be omitted. In Table (2), d
0 is the axial distance between the mask 2 and the lens surface closest to the mask, β is the imaging magnification, NA is the numerical aperture on the wafer side, and L is the distance from the object plane to the image plane of the synthetic optical system. Shows. Further, the numbers on the left end are the order of the lens surfaces from the mask side, 1 / r is the curvature of each lens surface, d is the distance between the lens surfaces, and n is the KrF laser light (λ = 248.4n).
The refractive index for m) is shown.

[0028]

[Table 2] d0 = 104.850 β = 1/5 NA = 0.57 L = 1200 Curvature (1 / r) dn 61 9.83500 × 10 ^-5 6.000 1.50839 62 0.00000 BF = 5.895 (Values corresponding to conditions) Φ1 = 0.00808 Φ2 = 5.0 × 10 ^-5 ΔΦ2 = 5.0 × 10 ^-5 (1) | Φ1 / Φ2 | = 162 (2) | L × ΔΦ2 | = 0.06

As shown in Table (2), in the first embodiment,
The combined power Φ1 of the rear group GR is 0.0080 as in the comparative example.
8 Further, the combined power Φ2 of the plano-convex lens forming the aberration correction optical system 4 is 5.0 × 10 ⁻⁵ . Therefore, the combined power change amount ΔΦ2 of the aberration correction optical system
Is 5.0 × 10 ⁻⁵ . At this time, the maximum image height = 15.6
The correction amount ΔCU of the curvature of field at −0.004 is −0.004. In the following table (3), when the combined power Φ2 of the aberration correction optical system 4 in the first example is changed, the change of | Φ1 / Φ2 | which is the value of the conditional expression (1), the conditional expression ( The change of | L × ΔΦ2 | which is the value of 2) and the change of the correction amount ΔCU of the curvature of field at the maximum image height = 15.6 are shown. As shown in Table (3), in the first example, by replacing the plane-parallel plate in the comparative example with a lens having an appropriate synthetic power, the telecentricity of the projection optical system 3 is not affected, Only the field curvature can be corrected well.

[0030]

[Table 3] Φ2 | Φ1 / Φ2 | | L × ΔΦ2 | ΔCU +10.1 × 10 ^-5 80 0.121 -0.008 +5.0 × 10 ^-5 162 0.06 -0.004 +2.50 × 10 ^-5 324 0.03 -0.002 -2.50 × 10 ^-5 324 0.03 +0.002 -5.0 × 10 ^-5 162 0.06 +0.004 -10.1 × 10 ^-5 80 0.121 +0.008

Second Example In the second example, in order to correct the coma aberration of the projection optical system 3, the parallel plane plate in the comparative example is replaced with a no-power lens having a convex surface facing the wafer. That is, in the second embodiment, the surface power of the mask-side surface and the surface power of the wafer-side surface of the aberration correction optical system 4 are changed without changing the combined power of the aberration correction optical system 4. .

The following table (4) shows the values of specifications of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the second embodiment. However, since the values of the specifications of the projection optical system 3 are the same as those of the comparative example, duplicate description will be omitted. In Table (4), d0 is the axial distance between the mask 2 and the lens surface closest to the mask, β is the imaging magnification, NA is the numerical aperture on the wafer side, and L is the image from the object plane of the combining optical system. The distance to each surface is shown. The leftmost number is the order of the lens surfaces from the mask side, 1 / r is the curvature of each lens surface, d is the distance between the lens surfaces, and n is the KrF laser light (λ
= 248.4 nm).

[0033]

[Table 4] d0 = 104.850 β = 1/5 NA = 0.57 L = 1200 Curvature (1 / r) dn 61 -4.10745 × 10 ^-5 6.000 1.50839 62 -4.10745 × 10 ^-5 BF = 5.901 (Values corresponding to conditions) Φ1 = 0.00808 Φ2 = 0 ΔΦ3 = -2.088 × 10 ^-5 ΔΦ4 = 2.088 × 10 ^-5 (1) | Φ1 / Φ2 | = ∞ (3) | L × ΔΦ3 | = 0.0251 (4) | L × ΔΦ4 | = 0.0251

As shown in Table (4), in the second embodiment,
The combined power Φ1 of the rear group GR is 0.0080 as in the comparative example.
8 In addition, the combined power Φ2 of the no-power lens that constitutes the aberration correction optical system 4 is zero. Furthermore, the surface power on the mask side of the aberration correction optical system 4 is -2.088 ×
Since it is 10 ⁻⁵ , the amount of change ΔΦ3 is −2.088 × 10 ⁻⁵ . On the other hand, since the surface power on the wafer side is 2.088 × 10 ⁻⁵ , the amount of change ΔΦ4 is 2.088 × 10 ⁻⁵ . At this time, the coma aberration correction amount ΔC at the maximum image height = 15.6.
M is 0.002.

The following table (5) shows the value of | L × ΔΦ3 | which is the conditional expression (3) when the surface power change amounts ΔΦ3 and ΔΦ4 of the aberration correction optical system 4 in the second embodiment are changed. , The change of the value of | L × ΔΦ4 | which is the conditional expression (4), and the change of the coma aberration correction amount ΔCM at the maximum image height = 15.6. It should be noted that | Φ which is the conditional expression (1)
The value of 1 / Φ2 | is the surface power change amount ΔΦ3 and ΔΦ4.
It is always infinite without change depending on. As shown in Table (5), in the second example, by replacing the plane-parallel plate in the comparative example with a no-power lens having an appropriate surface power, the telecentricity of the projection optical system 3 is not affected, and Only the coma aberration can be corrected well.

[0036]

[Table 5] ΔΦ3 ΔΦ4 │L × ΔΦ3 ｜ │L × ΔΦ4 ｜ ΔCM + 333.3 × 10 ^-5 -333.3 × 10 ^-5 4 4 -0.260 + 33.33 × 10 ^-5 -33.33 × 10 ^-5 0.4 0.4 -0.031 + ^{2.088 × 10 -5 -2.088 × 10 -5} 0.0251 0.0251 -0.002 -2.088 × 10 -5 + 2.088 × 10 -5 0.0251 0.0251 +0.002 -33.33 × 10 -5 + 33.33 × 10 -5 0.4 0.4 +0.031 -333.3 × 10 ^-5 +33 3.3 x 10 ^-5 4 4 +0.260

[Third Embodiment] In the third embodiment, in order to correct the field curvature and the coma of the projection optical system 3, the parallel plane plate in the comparative example is a positive meniscus lens having a convex surface facing the wafer. Is replaced with. That is, in the third embodiment, the combined power of the aberration correction optical system 4 is changed, and the surface power of the mask-side surface and the surface power of the wafer-side surface of the aberration correction optical system 4 are changed.

The following table (6) lists the values of specifications of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the third embodiment. However, since the values of the specifications of the projection optical system 3 are the same as those of the comparative example, duplicate description will be omitted. In Table (6), d0 is the axial distance between the mask 2 and the lens surface closest to the mask, β is the imaging magnification, NA is the numerical aperture on the wafer side, and L is the image from the object plane of the combining optical system. The distance to each surface is shown. The leftmost number is the order of the lens surfaces from the mask side, 1 / r is the curvature of each lens surface, d is the distance between the lens surfaces, and n is the KrF laser light (λ
= 248.4 nm).

[0039]

[Table 6] d0 = 104.850 β = 1/5 NA = 0.57 L = 1200 Curvature (1 / r) dn 61 -3.53418 x 10 ^-4 6.000 1.50839 62 -4.51000 x 10 ^-4 BF = 5.910 (value corresponding to the condition) Φ1 = 0.00808 Φ2 = 5.0 × 10 ^-5 ΔΦ2 = 5.0 × 10 ^-5 ΔΦ3 = -17.97 × 10 ^-5 ΔΦ4 = 22.93 × 10 ^-5 (1) | Φ1 / Φ2 | = 162 (2) | L × ΔΦ2 | = 0.06 (3) | L × ΔΦ3 | = 0.216 (4) | L × ΔΦ4 | = 0.275

As shown in Table (6), in the third embodiment,
The combined power Φ1 of the rear group GR is 0.0080 as in the comparative example.
8 The combined power Φ2 of the positive meniscus lens forming the aberration correction optical system 4 is 5.0 × 10 ⁻⁵ . Therefore, the combined power change amount ΔΦ2 of the aberration correction optical system is 5.0 × 10 ⁻⁵ . Furthermore, the amount ΔΦ3 of change in the surface power of the aberration correction optical system 4 on the mask side is −17.97 × 10
^-5 , and the variation ΔΦ4 of the surface power on the wafer side is 22.
It is 93 x 10 ^-5 . At this time, the correction amount ΔCU of the field curvature at the maximum image height = 15.6 is −0.004, and the correction amount ΔCM of the coma aberration is 0.004. Thus, in the third embodiment, only the field curvature and the coma aberration can be satisfactorily corrected without affecting the telecentricity of the projection optical system 3.

[Fourth Embodiment] In the fourth embodiment, in order to correct the spherical aberration, the field curvature and the coma of the projection optical system 3, the parallel plane plate in the comparative example is set to the thickness of the parallel plane plate. It is replaced by a positive meniscus lens having a different axial thickness and having a convex surface facing the wafer. That is, in the third example, the combined power of the aberration correction optical system 4 is changed, the surface power of the mask-side surface and the surface power of the wafer-side surface of the aberration correction optical system 4 are changed, and the aberration correction is performed. The axial thickness of the optical system 4 is changed.

Table (7) below lists the values of the parameters of the synthetic optical system including the projection optical system 3 and the aberration correction optical system 4 in the fourth embodiment. However, since the values of the specifications of the projection optical system 3 are the same as those of the comparative example, duplicate description will be omitted. In Table (7), d0 is the axial distance between the mask 2 and the lens surface closest to the mask, β is the imaging magnification, NA is the numerical aperture on the wafer side, and L is the image from the object plane of the combining optical system. The distance to each surface is shown. The leftmost number is the order of the lens surfaces from the mask side, 1 / r is the curvature of each lens surface, d is the distance between the lens surfaces, and n is the KrF laser light (λ
= 248.4 nm).

[0043]

[Table 7] d0 = 104.850 β = 1/5 NA = 0.57 L = 1200 Curvature (1 / r) dn 61 -2.59654 × 10-4 6.077 1.50839 62 -3.32907 × 10-4 BF = 5.856 (conditional value) Φ1 = 0.00808 Φ2 = 3.73 × 10 ^-5 ΔΦ2 = 3.73 × 10 ^-5 ΔΦ3 = -13.20 × 10 ^-5 ΔΦ4 = 16.92 × 10 ^-5 BF = 5.856 Δd = 0.077 (1) | Φ1 / Φ2 | = 217 (2) ) | L × ΔΦ2 | = 0.0447 (3) | L × ΔΦ3 | = 0.158 (4) | L × ΔΦ4 | = 0.203 (5) | BF / Δd | = 76.05

As shown in Table (7), in the fourth embodiment,
The combined power Φ1 of the rear group GR is 0.0080 as in the comparative example.
8 In addition, the combined power Φ2 of the positive meniscus lens that constitutes the aberration correction optical system 4 is 3.73 × 10 ⁻⁵ . Therefore, the combined power change amount ΔΦ2 of the aberration correction optical system is 3.73 × 10 ⁻⁵ . Furthermore, the variation ΔΦ3 of the surface power on the mask side of the aberration correction optical system 4 is −13.20 × 10
^-5 , and the variation ΔΦ4 of the surface power on the wafer side is 16.
It is 92 × 10 ^-5 . At this time, the correction amount ΔCU of the field curvature at the maximum image height = 15.6 is −0.003, the correction amount ΔCM of the coma aberration is 0.003, and the correction amount ΔSA of the spherical aberration is ΔSA.
Is 0.01. Thus, in the fourth example, only spherical aberration, field curvature, and coma can be corrected well without affecting the telecentricity of the projection optical system 3.

In the above embodiments, various correction optical systems 4 as aberration correction optical elements are arranged in the telecentric optical path of the projection optical system 3 to correct aberrations well. In, the optimum configuration of the projection optical system 3 that can sufficiently exert the correction effect by the correction optical system 4 will be described.

The projection optical system 3 shown in FIG. 1 and Table 1 has a front lens group GF having a positive refractive power, which is arranged on the object side (mask 2 side) of the diaphragm S, and on the image side of the diaphragm S ( A rear lens group GR having a positive refractive power, which is disposed on the substrate 5 side), and a front lens group GF of the first lens group G1 having a positive refractive power in order from the object side (mask 2 side). , A second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power, and a rear lens group GR.
Has a fifth lens group G5 having a positive refractive power and a sixth lens group G6 having a positive refractive power.

Based on this basic structure, the focal length of the first lens group is f ₁ , the focal length of the second lens group is f ₂ , the focal length of the third lens group is f ₃ , and the fourth lens is The focal length of the group is f ₄ , the focal length of the fifth lens group is f ₅ , the focal length of the sixth lens group is f ₆ , and the distance between the object images in the combined optical system of projection optical system 3 and aberration correction optical system 4 is When the distance (distance from the mask 2 to the substrate 5) is L, it is preferable to satisfy the following conditions (11) to (14). (11) 0.1 <f ₁ / f ₃ <17 (12) 0.1 <f ₂ / f ₄ <14 (13) 0.01 <f ₅ /L<0.9 (14) 0.02 < f ₆ /L<1.6

With the projection optical system 3 having the above construction, first, the first lens group having a positive refractive power mainly contributes to distortion correction while maintaining the telecentricity. A positive distortion is generated in the lens group, and the negative distortion generated in the plurality of lens groups located closer to the second object side (substrate 5 side) than the first lens group is corrected in a well-balanced manner. Second lens group having negative refracting power and fourth lens group having negative refracting power
The lens group mainly contributes to the Petzval sum correction and aims to flatten the image plane. In the second lens group having negative refracting power and the third lens group having positive refracting power, an inverse telephoto system is formed by these two lens groups, and the projection optical system 3
Back focus (the distance from the optical surface such as the lens surface of the projection optical system closest to the substrate 5 to the substrate 5) is ensured. The fifth lens group having a positive refractive power and the sixth lens group having a positive refractive power also have a spherical aberration particularly to suppress the generation of distortion and to sufficiently cope with a high NA on the second object side. It mainly contributes to minimizing the occurrence.

Under the condition (11), the optimum ratio between the focal length f ₁ of the first lens unit having a positive refractive power and the focal length f ₃ of the third lens unit having a positive refractive power, that is, the first lens unit And the optimum distribution of the refractive power of the third lens group.
This condition (11) is mainly for correcting distortion in a well-balanced manner, and if the lower limit of this condition (11) is exceeded, the refractive power of the third lens group will be greater than that of the first lens group. Since it becomes relatively weak, a large amount of negative distortion occurs. On the other hand, when the value exceeds the upper limit of the condition (11), the refractive power of the first lens group becomes relatively weaker than that of the third lens group, so that large negative distortion occurs.

Under the condition (12), the optimum ratio between the focal length f ₂ of the second lens unit having a negative refractive power and the focal length f ₄ of the fourth lens unit having a negative refractive power, that is, the second lens unit And the optimum distribution of the refractive power between the fourth lens group and the fourth lens group.
This condition (12) mainly reduces Petzval sum,
This is to satisfactorily correct the field curvature while ensuring a wide exposure field. If the lower limit of this condition (12) is exceeded, the refractive power of the fourth lens group will be greater than that of the second lens group. As a result, the positive Petzval sum is large. If the upper limit of condition (12) is exceeded,
Since the refractive power of the second lens group is relatively weaker than the refractive power of the fourth lens group, a large positive Petzval sum is generated. In order to make the refracting power of the fourth lens group relatively strong with respect to the refracting power of the second lens group and correct Petzval sum in a wider exposure field with a better balance, the above condition (12 ), The lower limit value of 0.8 is 0.8.
It is preferable that 8 <f ₂ / f ₄ .

Under the condition (13), the focal length f ₅ of the fifth lens group having a positive refractive power and the distance between the mask 2 and the photosensitive substrate 5 such as a wafer (the projection optical system 3 and the aberration correction optical system 4 And the object-image distance in the synthetic optical system of L) is defined as the optimum ratio. This condition (13) is for correcting spherical aberration, distortion, and Petzval sum in good balance while maintaining a large numerical aperture. When the value goes below the lower limit of the condition (13), the refracting power of the fifth lens group becomes too large, and negative spherical aberration as well as negative distortion is significantly generated in the fifth lens group. If the upper limit of this condition (13) is exceeded, the refracting power of the fifth lens group will become too weak, and the refracting power of the fourth lens group having a negative refracting power will inevitably weaken accordingly. As a result, the Petzval sum Cannot be corrected well.

Under the condition (14), the focal length f ₆ of the sixth lens unit having a positive refractive power and the distance between the mask 2 and the photosensitive substrate 5 such as a wafer (the projection optical system 3 and the aberration correction optical system 4 And the object-image distance in the synthetic optical system of L) is defined as the optimum ratio. This condition (14) is for suppressing the generation of high-order spherical aberration and negative distortion while maintaining a large numerical aperture. If the lower limit of this condition (14) is exceeded,
A large negative distortion occurs in the sixth lens group itself, and if the upper limit of this condition (14) is exceeded, high-order spherical aberration will occur.

In order to achieve a sufficient aberration function in each of the above lens groups, it is desirable to have the following constructions. First, in order for the first lens group to have a function of suppressing the generation of high-order distortion and spherical aberration of the pupil, it is preferable that the first lens group has at least two positive lenses, and the third lens group In order to have a function of suppressing deterioration of spherical aberration and Petzval sum in the above, it is preferable that the third lens group has at least three positive lenses, and further, while correcting the Petzval sum in the fourth lens group. In order to have a function of suppressing the occurrence of coma, it is preferable that the fourth lens group has at least three negative lenses. Further, in order to have a function of suppressing the occurrence of negative distortion and spherical aberration in the fifth lens group, it is preferable that this fifth lens group has at least five positive lenses, and further, in the fifth lens group, In order to have the function of correcting the negative distortion and Petzval sum, it is preferable that the fifth lens group has at least one negative lens. Further, in order to focus light on the second object so that spherical aberration is not largely generated in the sixth lens group, it is preferable that the sixth lens group has at least one positive lens.

Further, preferably, the second lens group G2 is
It is arranged on the most object side (mask 2 side) and is on the image side (substrate 5).
Front lens L2F with negative refractive power with concave surface facing
And a rear lens L2R arranged on the most image side (substrate 5 side) and having a negative refractive power with a concave surface facing the object side (mask 2 side).
And an intermediate lens group L2M disposed between the front lens L2F in the second lens group and the rear lens L2R in the second lens group.
The intermediate lens unit L2M includes an object side (mask 2
Side), a first lens L21 having a positive refracting power, a second lens L22 having a negative refracting power, a third lens L23 having a negative refracting power, and a fourth lens having a negative refracting power. L24 and at least a composite focal length from the second lens to the fourth lens in the second lens group is f _n ,
It is desirable to satisfy the following condition (15). (15) 0.01 <f _n / f ₂ <2.0

In the case of this configuration, the image side (the substrate 5 side) is arranged on the most object side (mask 2 side) in the second lens group.
The front lens L2F having a negative refracting power with the concave surface facing to contributes to the correction of the field curvature and the coma aberration, is arranged on the most image side (substrate 5 side) in the second lens group, and is arranged on the object side (mask 2
Rear lens L2R with a negative refractive power facing the side)
Contributes to correction of field curvature, coma and astigmatism. In addition, in the intermediate lens unit L2M disposed between the front lens L2F and the rear lens L2R, the first lens L21 having a positive refractive power has a negative refractive power that greatly contributes to correction of field curvature. It contributes to the correction of the negative distortion generated in the second to fourth lenses (L22 to L24).

Under the condition (15), the combined focal length f _n from the second lens L22 having a negative refractive power to the fourth lens L24 having a negative refractive power in the intermediate lens group L2M in the second lens group and the second lens It defines the optimum ratio with the focal length f _{2 of the} group. However, the intermediate lens group L2M of the second lens group referred to here
The composite focal length f _n from the second lens L22 having a negative refractive power to the fourth lens L24 having a negative refractive power in is the composite focal length of the three lenses from the second lens L22 to the fourth lens L24. Not only does this mean that when there are a plurality of lenses between the second lens and the fourth lens, a combination of three or more lenses from the second lens L22 to the fourth lens L24 is included. It means the focal length.

This condition (15) is for keeping the Petzval sum small while suppressing the occurrence of distortion. When the lower limit of this condition (15) is exceeded, the negative sub-lens group including at least three negative lenses from the negative second lens L22 to the negative fourth lens L24 in the intermediate lens group in the second lens group is included. Since the combined refractive power becomes too strong, a large amount of negative distortion occurs. Note that in order to sufficiently correct distortion and coma, the lower limit of condition (15) above is set to 0.1 and 0.1 <
It is preferably f _n / f ₂ .

If the upper limit of this condition (15) is exceeded, the negative second lens L in the intermediate lens unit L2M in the second lens unit will be used.
Since the refractive power of the negative sub-lens group including at least three negative lenses from 22 to the negative fourth lens L24 becomes too weak, not only a large positive Petzval sum occurs but also the refraction of the third lens group. The force becomes weak, and it becomes difficult to make the projection optical system 3 compact. It should be noted that in order to make the Petzval sum well corrected and to achieve a more compact size,
Setting the upper limit of condition (15) above to 1.3, f _n / f ₂ <
It is preferably 1.3. In order to correct Petzval's sum better, it is preferable that the intermediate lens unit L2M in the second lens unit has a negative refractive power.

In addition, from the object (mask 2) to the projection optical system 3
Is the on-axis distance to the entire object side (mask 2 side) focus
Then, it is preferable that the following conditions are satisfied. (16) 1.0 <I / L Under the condition (16), the axial distance from the object (mask 2) to the focal point of the entire projection optical system on the object side (mask 2 side), the projection optical system 3, and the aberration correction optical system. The optimum ratio with the distance L between the object and the image (distance from the mask 2 to the substrate 5) in the synthetic optical system with the system 4 is defined. Here, the first object-side focus of the entire projection optical system means that parallel light in a paraxial region with respect to the optical axis of the projection optical system 3 is incident from the image side (substrate 5 side) of the projection optical system 3.
It means a point at which the emitted light intersects the optical axis when the light in the paraxial region exits the projection optical system 3.

If the lower limit of this condition (16) is exceeded, the telecentricity on the object side (mask 5 side) of the projection optical system will be greatly impaired, and the magnification due to the displacement of the object (mask 5) in the optical axis direction will be reduced. And the fluctuation of distortion become large, and as a result, it becomes difficult to faithfully project the image of the object (mask 5) on the substrate 5 under a desired magnification.
In order to more sufficiently suppress the fluctuation of the magnification and the fluctuation of the distortion due to the displacement of the object (mask 5) in the optical axis direction, the lower limit of the condition (16) is set to 1.7 and 1.7 < It is preferably I / L. Further, in order to correct the spherical aberration and the distortion of the pupil in a well-balanced manner while maintaining the compactness of the projection optical system 3, the upper limit of the condition (16) is set to 6.8 and I /
It is preferable that L <6.8.

[0061] Further, the focal length of the third lens L23 having a negative refractive power in the second lens group and f _23, the focal length of the fourth lens L24 having a negative refractive power in the second lens group f _{When it is 24} , it is more preferable to satisfy the following condition (17). (17) 0.07 <f ₂₄ / f ₂₃ <7

When the lower limit of the condition (17) is exceeded, the refracting power of the negative fourth lens L24 becomes relatively strong with respect to the refracting power of the negative third lens L23, and at the negative fourth lens L24, Large coma and negative distortion occur. In order to satisfactorily correct the coma aberration while correcting the negative distortion, it is preferable that the lower limit value of the condition (17) is 0.14 and 0.14 <f ₂₄ / f ₂₃ . When the upper limit of this condition (17) is exceeded, the refracting power of the negative third lens L23 becomes relatively strong with respect to the refracting power of the negative fourth lens L24, resulting in coma at the negative third lens L23. Large negative distortion occurs. While correcting coma aberration,
To better compensate for negative distortion,
Assuming that the upper limit of condition (17) is 3.5, f ₂₄ / f ₂₃ <
It is preferably 3.5.

The intermediate lens group L2M in the second lens group
The focal length of the second lens L ₂₂ having a negative refractive power and f _22, the focal length of the third lens L ₂₃ having a negative refractive power in the intermediate lens group L2M in the second lens group and f ₂₃ in At this time, it is more desirable to satisfy the following condition (8). (18) 0.1 <f ₂₂ / f ₂₃ <10

[0064] Condition (18) exceeds the lower limit of the refractive power of the negative second lens L ₂₂ becomes relatively resistant to the refractive power of the third negative lens L _23, a negative second lens L ₂₂ At, large coma aberration and negative distortion occur. To correct more negative distortion in a well-balanced manner, the lower limit of condition (18) is set to 0.2, and 0.2 <f ₂₂ /
It is preferably f ₂₃ . Above the upper limit of this condition (18), at the negative refractive power of the third lens L ₂₃ becomes relatively resistant to the refractive power of the negative second lens L _22, a negative third lens L ₂₃ Large coma and negative distortion occur. In order to correct more negative distortion in a well-balanced manner while satisfactorily correcting coma aberration, it is preferable to set the upper limit of condition (18) to 5 and set f ₂₄ / f ₂₃ <5.

Further, from the image side (substrate 5 side) lens surface of the fourth lens L _{22 having} negative refractive power in the intermediate lens group of the second lens group to the object side of the rear lens L 2 R in the second lens group ( The on-axis distance to the lens surface (on the mask 2 side) is D, and the object-image distance (distance from the mask 2 to the substrate 5) L in the combined optical system with the projection optical system 3 and the aberration correction optical system 4 is L. At this time, it is more desirable to satisfy the following condition (19). (19) 0.05 <D / L <0.4

When the lower limit of the condition (19) is exceeded, it becomes difficult not only to secure a sufficient back focus on the image side (substrate 5 side) but also to correct the Petzval sum satisfactorily. . If the upper limit of condition (19) is exceeded, large coma and negative distortion will occur. Furthermore, for example, the mask 2 (or reticle) as an object
It may be preferable to secure a sufficient space between the mask 2 and the first lens group in order to avoid mechanical interference between the mask stage holding the lens and the first lens group, but the condition (19) When the upper limit of is exceeded, there is a problem that it is difficult to secure this space sufficiently.

Table (8) below shows the values corresponding to the conditions (11) to (19) of the projection optical system 3 shown in Table 1.

[Table 8] f ₁ / f ₃ = 1.53 f ₂ / f ₄ = 0.956 f ₅ /L=0.124 f ₆ /L=0.160 f _n / f ₂ = 0.576 I / L = 2.89 f ₂₄ / f ₂₃ = 0.805 f _{22 / f 23 = 1.01 D /} L = 0.0850

In each of the above-described embodiments, the correction optical member 4 as the aberration correction optical system is arranged in the optical path of the projection optical system 3 on the telecentric image side. It may be arranged in the optical path of the system 3 on the telecentric object side, or the present invention can be applied to a one-side telecentric optical system in which either the object side or the image side is telecentric. In each of the above-described embodiments, the present invention is applied to the projection optical system of the projection exposure apparatus, but the present invention can be applied to other suitable telecentric optical systems.

In the above embodiments, the projection optical system 3 and the aberration correction optical system 4 are all made of quartz (SiO ₂ ), but the present invention is not limited to this, and only fluorite or quartz and fluorite is used. It may be configured in combination with. Furthermore, the optical members that form the projection optical system 3 and the aberration correction optical system 4 are not limited to quartz and fluorite, and may be any combination of optical materials that transmit light of the exposure wavelength. Further, in the above-described embodiments, the projection optical system 3 is configured by only the refracting optical member as a refracting system. However, this is a reflecting system only by a reflecting member or a catadioptric system combining a refracting member and a reflecting member. You may comprise.

[0070]

As described above, according to the present invention, the optical power is changed by changing the surface power of at least one surface of the aberration correction optical system arranged in the telecentric optical path on the object side or the image side of the optical system. The rotational symmetry aberration of is corrected. Therefore, unlike the related art, it is not necessary to prepare many kinds of adjustment washers, and the rotationally symmetric aberration of the optical system can be finely adjusted quickly and accurately. When the present invention is applied to the projection exposure apparatus, rotational symmetry aberration of the projection optical system can be finely adjusted quickly and accurately to improve transfer accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing a main configuration of a projection exposure apparatus including an aberration correction optical system according to each embodiment of the present invention.

FIG. 2 is a diagram showing a lens configuration of a projection optical system and an aberration correction optical system in each example.

FIG. 3 shows KrF laser light (λ = 24) of a synthetic optical system including a projection optical system 3 and an aberration correction optical system 4 in a comparative example.
FIG. 8 is a diagram of various aberrations for 8.4 nm).

[Explanation of symbols]

 1 Illumination Optical System 2 Mask 3 Projection Optical System 4 Aberration Correction Optical System 5 Wafer S Aperture GR Rear Group (Partial Lens Group)

Claims (11)

[Claims] 1. An aberration correction method for correcting an aberration of an optical system telecentric on at least one of an object side and an image side, wherein an aberration correction optical system arranged in a telecentric optical path on the object side or the image side of the optical system. To correct the aberration of the optical system by changing the surface power of at least one surface of the optical system, and to combine the partial lens group of the optical system between the diaphragm disposed in the optical system and the aberration correction optical system. Power Φ1
And a combined power of the aberration correction optical system is Φ2, the condition of | Φ1 / Φ2 |> 80 is satisfied. 2. The aberration correction method for an optical system according to claim 1, wherein the aberration of the optical system is corrected by replacing the aberration correction optical system. 3. The aberration correction method for an optical system according to claim 1, wherein the field curvature of the optical system is corrected by changing the synthetic power of the aberration correction optical system. 4. A distance from an object plane to an image plane of a synthetic optical system including the aberration correction optical system and the optical system is L,
The aberration correction method for an optical system according to claim 3, wherein a condition of | L × ΔΦ2 | <0.4 is satisfied, where ΔΦ2 is a combined power change amount of the aberration correction optical system. 5. The optical power is changed by changing the surface power of the object-side surface and the surface power of the image-side surface of the aberration correction optical system without changing the combined power of the aberration correction optical system. The aberration correction method for an optical system according to claim 1, wherein the coma aberration of the system is corrected. 6. The aberration correction optical system, wherein L is the total length of a combined optical system including the aberration correction optical system and the optical system, and ΔΦ3 is the surface power change amount of the object side surface of the aberration correction optical system. The aberration correction of the optical system according to claim 5, wherein the condition of | L × ΔΦ3 | <4 | L × ΔΦ4 | <4 is satisfied, where ΔΦ4 is the surface power change amount of the image-side surface. Method. 7. The optical system by changing the combined power of the aberration correction optical system and by changing the surface power of the object side surface and the surface power of the image side surface of the aberration correction optical system, respectively. 3. The aberration correction method for an optical system according to claim 1, wherein the field curvature and the coma aberration are corrected. 8. A distance from the object plane to the image plane of a synthetic optical system including the aberration correction optical system and the optical system is L,
The surface power change amount of the object side surface of the aberration correction optical system is Δ
8. When Φ3 and the surface power change amount of the image-side surface of the aberration correction optical system is ΔΦ4, the condition of | L × ΔΦ3 | <4 | L × ΔΦ4 | <4 is satisfied. The aberration correction method for an optical system described in. 9. The optical system according to claim 3, wherein spherical aberration of the optical system is further corrected by changing an axial thickness of the aberration correction optical system. System aberration correction method. 10. When the back focus of a synthetic optical system including the aberration correction optical system and the optical system is BF and the variation amount of the axial thickness of the aberration correction optical system is Δd, | BF / Δd The aberration correction method for an optical system according to claim 9, wherein the condition of |> 30 is satisfied. 11. A projection exposure apparatus comprising an illumination optical system for illuminating a mask on which a predetermined pattern is formed, and a projection optical system for forming a pattern image of the mask on a photosensitive substrate, The projection optical system is configured to have a diaphragm, a front group arranged between the mask and the diaphragm, and a rear group arranged between the diaphragm and the substrate. At least one of the side and the substrate side is configured to be telecentric, an aberration correction optical system is provided in a telecentric optical path on the mask side or the substrate side of the projection optical system, and the diaphragm and the diaphragm in the projection optical system. The composite power of the partial lens group of the projection optical system between the aberration correction optical system and
1 and the combined power of the aberration correction optical system is Φ2, the condition of | Φ1 / Φ2 |> 80 is satisfied, and at least one of the mask-side surface and the substrate-side surface of the aberration correction optical system is satisfied. The projection exposure apparatus is characterized in that the surface power of the surface is changed to correct the aberration of the projection optical system.