Projection imaging optical system with adjustable multiplying power and photoetching equipment with projection imaging optical system

Abstract

The invention discloses a projection imaging optical system with adjustable multiplying power and photoetching equipment, a first lens group, an aperture diaphragm and a second lens group are sequentially arranged in a direction from an object plane to an image plane, a cylindrical lens group is arranged between the object plane and the first lens group, or the cylindrical lens group is arranged between the image plane and the second lens group; the cylindrical lens group is composed of a first cylindrical lens with positive focal power and a second cylindrical lens with negative focal power, the generatrix of the first cylindrical lens and the generatrix of the second cylindrical lens are arranged in parallel, and the generatrix of the first cylindrical lens and the generatrix of the second cylindrical lens extend in the first direction; by adjusting the distance between the first cylindrical lens and the second cylindrical lens along the optical axis, the projection magnification of the image plane along the second direction is changed, the projection magnification of the image plane along the first direction is not changed, the first direction and the second direction are both parallel to the image plane, and the second direction is perpendicular to the first direction.

Description

Technical Field

[0001] The invention relates to the field of optical systems, and in particular to a projection imaging optical system with adjustable magnification and a photolithography device having the same. Background Art

[0002] Many substrates such as printed circuit boards, liquid crystal panels, and color filters for liquid crystals require photolithography for processing. With the development of short, light, thin, high-density, and multi-layered, photolithography equipment is required to have high-resolution and high-precision multi-layer alignment functions. Since some substrates are prone to expansion and contraction in terms of material properties, especially some substrate materials have different structural characteristics in the width and length directions, and the expansion and contraction in different directions after multiple process treatments are also different, under the conditions of high resolution and high precision, the expansion and contraction of these substrates and the anisotropic expansion and contraction have become factors that cannot be ignored, requiring the use of projection photolithography equipment with projection magnification adjustment and anisotropic projection magnification adjustment functions to cope with and absorb them. Summary of the invention

[0003] The object of the present invention is to provide a projection imaging optical system with adjustable magnification and a photolithography device having the same, which has the function of adjusting the projection magnification.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] According to a first aspect of the present invention, there is provided a projection imaging optical system with adjustable magnification, wherein a first lens group, an aperture stop, and a second lens group are sequentially arranged from the object plane to the image plane, a cylindrical lens group is arranged between the object plane and the first lens group, or the cylindrical lens group is arranged between the image plane and the second lens group, the cylindrical lens group consists of a first cylindrical lens with positive focal length and a second cylindrical lens with negative focal length, a generatrix of the first cylindrical lens is arranged parallel to a generatrix of the second cylindrical lens, and the generatrix of the first cylindrical lens and the generatrix of the second cylindrical lens both extend along a first direction, by adjusting the spacing between the first cylindrical lens and the second cylindrical lens along the optical axis, the projection magnification of the image plane along the second direction is changed, and the projection magnification of the image plane along the first direction remains unchanged, the first direction and the second direction are both parallel to the image plane, and the second direction is perpendicular to the first direction;

[0006] The projection imaging optical system with adjustable magnification satisfies the relationship:

[0007] 0.2 <WD / Hy<10;

[0008] |(fy1+fy2)| / (fy1-fy2)<0.1;

[0009] fy1 / Hy>15;

[0010] t / (fy1-fy2)<0.005;

[0011] NA*Hy / (fy1-fy2)<0.004;

[0012] Wherein WD is the distance from the cylindrical lens group to the adjacent object plane or the image plane, Hy is the maximum height of the object plane or the image plane adjacent to the cylindrical lens group along the first direction, fy1 and fy2 are the focal lengths of the first cylindrical lens and the second cylindrical lens respectively, t is the spacing between the first cylindrical lens and the second cylindrical lens along the optical axis, when the cylindrical lens group is arranged between the object plane and the first lens group, NA is the numerical aperture of the object plane, and when the cylindrical lens group is arranged between the image plane and the second lens group, NA is the numerical aperture of the image plane.

[0013] In one embodiment, the first cylindrical lens has a first plane and a first curved surface, the second cylindrical lens has a second plane and a second curved surface, the first curved surface and the second curved surface are both quadratic surfaces, and the first curved surface and the second curved surface are adjacent to each other.

[0014] In one embodiment, the surface equations of the first curved surface and the second curved surface are the same or in a proportional relationship.

[0015] In one embodiment, the first plane and the second plane are parallel to the object plane and the image plane.

[0016] In one embodiment, the projection imaging optical system with adjustable magnification is an object-side telecentric optical path and an image-side telecentric optical path.

[0017] In one embodiment, the first cylindrical lens and the second cylindrical lens are made of the same optical material, and both the first cylindrical lens and the second cylindrical lens satisfy Vd>50, where Vd is the dispersion coefficient.

[0018] In one embodiment, when the cylindrical lens group is arranged between the object plane and the first lens group, the distance between the cylindrical lens group and the first lens group is smaller than the distance between the cylindrical lens group and the object plane; when the cylindrical lens group is arranged between the image plane and the second lens group, the distance between the cylindrical lens group and the second lens group is smaller than the distance between the cylindrical lens group and the image plane.

[0019] In one embodiment, when the lens in the first lens group or the second lens group moves along the optical axis, the projection magnification of the image plane along the first direction and the second direction is changed by the same amount, so that the projection magnification of the image plane can be changed in conjunction with the cylindrical lens group.

[0020] In one embodiment, the magnification-adjustable projection imaging optical system satisfies the relational expression: 0.5 < WD / Hy < 5, and / or, the magnification-adjustable projection imaging optical system satisfies the relational expression: 200 > fy1 / Hy > 35.

[0021] The second aspect of the present invention provides a lithography apparatus, including the magnification-adjustable projection imaging optical system as described above, an optical mask located at the object plane position, and a substrate coated with a photosensitive material located at the image plane position. The lithography apparatus uses the magnification-adjustable projection imaging optical system to project the image on the optical mask onto the substrate.

[0022] The beneficial effect brought by the technical solution provided by the present invention is to provide a magnification-adjustable projection imaging optical system and a lithography apparatus having the same. By adjusting the distance between the first cylindrical lens and the second cylindrical lens along the optical axis, the projection magnification in the second direction of the image plane can be changed, and the projection magnification in the first direction of the image plane remains unchanged. Therefore, the projection magnification can be adjusted according to different substrate expansion and contraction characteristics, realizing the functions of high resolution and high-precision multi-layer alignment of the lithography apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 A top view schematic diagram of the magnification-adjustable projection imaging optical system provided in an embodiment of the present invention;

[0025] Figure 2 A three-dimensional schematic diagram of the cylindrical lens group provided in an embodiment of the present invention;

[0026] Figure 3 A rear view schematic diagram of the cylindrical lens group provided in an embodiment of the present invention;

[0027] Figure 4 A modulation transfer function (MTF) diagram of the magnification-adjustable projection imaging optical system provided in Embodiment 1 of the present invention;

[0028] Figure 5 A modulation transfer function (MTF) diagram of the magnification-adjustable projection imaging optical system provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0031] In one embodiment of the present invention, a projection imaging optical system with adjustable magnification is provided. The projection imaging optical system with adjustable magnification comprises an object-side telecentric optical path and an image-side telecentric optical path. A first lens group G1, an aperture stop AS, a second lens group G2 and a cylindrical lens group are sequentially arranged from the object plane P1 to the image plane P2, that is, the cylindrical lens group is arranged between the image plane P2 and the second lens group G2. A light beam emitted from the object plane G1 sequentially passes through the first lens group G1, the second lens group G2 and the cylindrical lens group and then converges to form an image on the image plane P2. The distance between the cylindrical lens group and the second lens group G2 is smaller than the distance between the cylindrical lens group and the image plane P2. In other embodiments, the cylindrical lens group may also be arranged between the object plane P1 and the first lens group G1, and the distance between the cylindrical lens group and the first lens group G1 is smaller than the distance between the cylindrical lens group and the object plane P1.

[0032] The cylindrical lens group is composed of a first cylindrical lens C1 with positive focal power and a second cylindrical lens C2 with negative focal power. The generatrix of the first cylindrical lens C1 is arranged in parallel with the generatrix of the second cylindrical lens C2. The first cylindrical lens C1 has a first plane and a first curved surface. The second cylindrical lens C2 has a second plane and a second curved surface. In other embodiments, the first cylindrical lens C1 can also be arranged to have two curved surfaces, and / or the second cylindrical lens C2 can be arranged to have two curved surfaces. Both the first curved surface and the second curved surface are quadratic curved surfaces. The first curved surface and the second curved surface are arranged adjacently, and the equations of the first curved surface and the second curved surface are the same or in a proportional relationship. The first plane and the second plane are parallel to the object plane P1 and the image plane P2.

[0033] The first cylindrical lens C1 and the second cylindrical lens C2 are made of the same optical material, specifically, it can be crown optical glass with a large dispersion coefficient, and both the first cylindrical lens C1 and the second cylindrical lens C2 satisfy Vd>50, where Vd is the dispersion coefficient.

[0034] The generatrices of the first cylindrical lens C1 and the second cylindrical lens C2 both extend along the first direction X. By adjusting the distance between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis, the projection magnification of the image plane P2 along the second direction Y is changed, and the projection magnification of the image plane P2 along the first direction X remains unchanged. The first direction X and the second direction Y are both parallel to the image plane P2, and the second direction Y is perpendicular to the first direction X.

[0035] Specifically, by setting a rotating platform with the optical axis direction as the axis of rotation, the cylindrical lens group is arranged on the rotating platform, so that the cylindrical lens group can rotate around the optical axis direction, thereby adjusting the direction of magnification correction of the image plane according to actual needs, such as Figure 3 shown, the arrow direction in the figure is the rotation direction of the cylindrical lens group.

[0036] The magnification-adjustable projection imaging optical system of the present invention satisfies the following relationship:

[0037] 0.2 < WD / Hy < 10, preferably, 0.5 < WD / Hy < 5; by restricting this relationship, the magnification-adjustable projection imaging optical system of the present invention can maintain a large working distance, which is convenient for operation, and can also maintain the optical performance without significant decline.

[0038] 0 < |(fy1 + fy2)| / (fy1 - fy2) < 0.1; by restricting this relationship, the first cylindrical lens C1 and the second cylindrical lens C2 will not have a large phase difference, and the optical performance will not decline.

[0039] fy1 / Hy > 15, preferably, 200 > fy1 / Hy > 35; by restricting this relationship, the first cylindrical lens C1 and the second cylindrical lens C2 will not have a large phase difference, and the optical performance will not decline.

[0040] 0 < t / (fy1 - fy2) < 0.005; by restricting this relationship, the first cylindrical lens C1 and the second cylindrical lens C2 will not have a large phase difference, the optical performance will not decline, and a large zoom effect can be produced.

[0041] NA*Hy / (fy1 - fy2) < 0.004; by restricting this relationship, the first cylindrical lens C1 and the second cylindrical lens C2 will not have a large phase difference, the optical performance will not decline, and a large zoom effect can be produced.

[0042] Wherein WD is the distance from the cylindrical lens group to the adjacent image plane P2, in mm, Hy is the maximum height of the image plane P2 adjacent to the cylindrical lens group along the first direction X, in mm, fy1 and fy2 are the focal lengths of the first cylindrical lens C1 and the second cylindrical lens C2, respectively, in mm, t is the spacing between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis, in mm, and NA is the numerical aperture of the image plane P2 adjacent to the cylindrical lens group.

[0043] In other embodiments, when the cylindrical lens group is arranged between the object plane P1 and the first lens group G1, WD is the distance from the cylindrical lens group to the adjacent object plane P1, Hy is the maximum height of the object plane P1 adjacent to the cylindrical lens group along the first direction X, and NA is the numerical aperture of the object plane P1 adjacent to the cylindrical lens group.

[0044] In the projection imaging optical system with adjustable magnification of the present invention, when the lens in the first lens group G1 or the second lens group G2 moves along the optical axis, the projection magnification of the image plane P2 along the first direction X and the second direction Y is changed by the same amount, so that it can be used in conjunction with the cylindrical lens group to change the projection magnification of the image plane P2.

[0045] The projection imaging optical system with adjustable magnification of the present invention can be applied to a lithography device, which includes an optical mask located at an object plane P1 and a substrate coated with a photosensitive material located at an image plane P2. The lithography device uses the projection imaging optical system with adjustable magnification to project the image on the optical mask onto the substrate, so that the projection magnification can be adjusted by adjusting the spacing between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis according to the different material properties of the substrate. The cylindrical lens group can also be rotated around the optical axis according to the telescopic direction of the substrate to ensure that the direction of the magnification correction is consistent with the actual required direction.

[0046] The lithography system of the present invention can be specifically applied to lithography systems such as micro-electro-mechanical systems (MEMS), liquid crystals, and printed circuit boards. The projection imaging optical system with adjustable magnification of the present invention can also be applied to the projection imaging optical system of photolithography.

[0047] Example 1

[0048] The magnification-adjustable projection imaging optical system in this embodiment is specifically configured as follows: Figure 1 As shown, the specific optical parameters are as follows Table 1:

[0049] Table 1

[0050] Optical parameters Numeric WD(mm) 65 Hy(mm) 100 NA 0.04 fy1(mm) 17387 fy2(mm) -18666 T(mm) 5 Vd 64.2

[0051] The magnification adjustment effect of the projection imaging optical system with adjustable magnification in this embodiment is shown in Table 2 below:

[0052] Table 2

[0053]

[0054] In Table 2, the negative sign represents that the distance between the first cylindrical lens and the second cylindrical lens becomes smaller.

[0055] According to the optical parameters in Table 1 and Table 2, the values ​​of the relationship in Table 3 are calculated:

[0056] Table 3

[0057] WD / Hy 0.62 |(f1+f2)| / (f1-f2) 0.03547555 f1 / Hy 173.87 t / (f1-f2) 0.000138685 NA*Hy / (f1-f2) 0.000110948

[0058] Figure 4 This is the transfer function MTF diagram of the projection imaging optical system with adjustable magnification of Example 1, where the spacing between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis is -4mm, the horizontal axis is the spatial frequency, the unit is line pair / millimeter (lp / mm), and the number of line pairs that can be distinguished per millimeter is the value of the resolution; the vertical axis is the modulation transfer function MTF (Modulation Transfer Function), which is a quantitative description of the resolution of the lens, and is used to represent the size of the contrast. The smaller the modulation, the smaller the contrast. If the contrast disappears completely, the modulation is 0. The closer the MTF value is to 1, the better the performance of the lens. Figure 4 It can be seen that in the field of view of the projection imaging optical system with adjustable magnification in this embodiment, the MTF values ​​of 0 field of view, 0.5 field of view and maximum field of view are close to the diffraction limit value (such as Figure 4 TSDIFF LIMIT in the figure), which means that the projection imaging optical system with adjustable magnification in this embodiment can have an MTF value close to the diffraction limit of physical optics in most of the fields of view within a wide visible light spectrum range, that is, the imaging quality index is close to the limit value under ideal conditions, and the imaging quality is very good.

[0059] Example 2

[0060] The magnification-adjustable projection imaging optical system in this embodiment is specifically configured as follows: Figure 1 As shown, the specific optical parameters are as follows Table 4:

[0061] Table 4

[0062] Optical parameters Numeric WD(mm) 134 Hy(mm) 100 NA 0.04 fy1(mm) 18011 fy2(mm) -18781 T(mm) 6 Vd 64.2

[0063] The magnification adjustment effect of the projection imaging optical system with adjustable magnification in this embodiment is shown in Table 2 below:

[0064] Table 5

[0065]

[0066]

[0067] In Table 5, the negative sign represents that the distance between the first cylindrical lens and the second cylindrical lens becomes smaller.

[0068] According to the optical parameters in Table 4 and Table 5, the values ​​of the relationship in Table 6 are calculated:

[0069] Table 6

[0070] WD / Hy 1.34 |(f1+f2)| / (f1-f2) 0.02093 f1 / Hy 180.11 t / (f1-f2) 0.00016 NA*Hy / (f1-f2) 0.00011

[0071] Figure 5 This is the transfer function MTF diagram of the projection imaging optical system with adjustable magnification of Example 2, where the spacing between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis is -4mm, the horizontal axis is the spatial frequency, the unit is line pair / millimeter (lp / mm), and the number of line pairs that can be distinguished per millimeter is the value of the resolution; the vertical axis is the modulation transfer function MTF (Modulation Transfer Function), which is a quantitative description of the resolution of the lens, and is used to represent the size of the contrast. The smaller the modulation, the smaller the contrast. If the contrast disappears completely, the modulation is 0. The closer the MTF value is to 1, the better the performance of the lens. Figure 5 It can be seen that in the field of view of the projection imaging optical system with adjustable magnification in this embodiment, the MTF values ​​of 0 field of view, 0.5 field of view and maximum field of view are close to the diffraction limit value (such as Figure 5 TSDIFF LIMIT in the figure), which means that the projection imaging optical system with adjustable magnification in this embodiment can have an MTF value close to the diffraction limit of physical optics in most of the fields of view within a wide visible light spectrum range, that is, the imaging quality index is close to the limit value under ideal conditions, and the imaging quality is very good.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0073] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A projection imaging optical system with adjustable magnification, characterized in that: A first lens group, an aperture stop, and a second lens group are sequentially arranged in the direction from the object plane to the image plane. The cylindrical lens group is arranged between the object plane and the first lens group, or the cylindrical lens group is arranged between the image plane and the second lens group. The cylindrical lens group is composed of a first cylindrical lens with a positive optical power and a second cylindrical lens with a negative optical power. The generatrix of the first cylindrical lens is arranged parallel to the generatrix of the second cylindrical lens. The generatrices of the first cylindrical lens and the second cylindrical lens both extend along a first direction. By adjusting the distance between the first cylindrical lens and the second cylindrical lens along the optical axis, the projection magnification of the image plane in the second direction changes, and the projection magnification of the image plane in the first direction remains unchanged. The first direction and the second direction are both parallel to the image plane, and the second direction is perpendicular to the first direction; The projection imaging optical system with adjustable magnification satisfies the relationship: 0.2 < WD / Hy < 10; |(fy1 + fy2)| / (fy1 - fy2) < 0.1; fy1 / Hy > 15; t / (fy1 - fy2) < 0.005; NA*Hy / (fy1 - fy2) < 0.004; where WD is the distance from the cylindrical lens group to the adjacent object plane or image plane, Hy is the maximum height of the adjacent object plane or image plane of the cylindrical lens group in the first direction, fy1 and fy2 are the focal lengths of the first cylindrical lens and the second cylindrical lens respectively, t is the distance between the first cylindrical lens and the second cylindrical lens along the optical axis. When the cylindrical lens group is arranged between the object plane and the first lens group, NA is the numerical aperture of the object plane. When the cylindrical lens group is arranged between the image plane and the second lens group, NA is the numerical aperture of the image plane.

2. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: The first cylindrical lens has a first plane and a first curved surface. The second cylindrical lens has a second plane and a second curved surface. Both the first curved surface and the second curved surface are aspherical surfaces, and the first curved surface and the second curved surface are arranged adjacent to each other.

3. The projection imaging optical system with adjustable magnification according to claim 2, characterized in that: The surface equations of the first curved surface and the second curved surface are the same or in a proportional relationship.

4. The projection imaging optical system with adjustable magnification according to claim 2, characterized in that: Both the first plane and the second plane are parallel to the object plane and the image plane.

5. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: The projection imaging optical system with adjustable magnification is an object-side telecentric optical path and an image-side telecentric optical path.

6. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: The first cylindrical lens and the second cylindrical lens are made of the same optical material, and both the first cylindrical lens and the second cylindrical lens satisfy Vd > 50, where Vd is the dispersion coefficient.

7. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: When the lenses in the first lens group or the second lens group move along the optical axis direction, the projection magnifications of the image plane in the first direction and the second direction change equally.

8. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: The projection imaging optical system with adjustable magnification satisfies the relationship: 0.5 < WD / Hy < 5, and / or, the projection imaging optical system with adjustable magnification satisfies the relationship: 200 > fy1 / Hy > 35.

9. The projection imaging optical system with adjustable magnification according to claim 1, characterized in that: The projection imaging optical system with adjustable magnification further includes a rotating platform with the optical axis direction as the rotation axis direction, and the cylindrical lens group is arranged on the rotating platform.

10. A lithography apparatus, characterized in that: It comprises a projection imaging optical system with adjustable magnification as described in any one of claims 1 to 9, an optical mask located at an object plane position, and a substrate coated with a photosensitive material located at an image plane position, and the lithography equipment uses the projection imaging optical system with adjustable magnification to project the image on the optical mask onto the substrate.

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