A projection imaging optical system with adjustable magnification and a lithographic apparatus having the same

Abstract

The application discloses a projection imaging optical system with adjustable magnification and a photoetching device, wherein a first lens group, an aperture diaphragm and a second lens group are sequentially arranged from an object plane to an image plane, a cylindrical lens group is arranged between the object plane and the first lens group or 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 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 along a second direction is changed, the projection magnification of the image plane along the first direction is 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.

Description

Technical Field

[0001] This invention relates to the field of optical systems, and more specifically to a magnified adjustable projection imaging optical system and a photolithography apparatus having the same. Background Technology

[0002] Many substrates, such as printed circuit boards (PCBs), LCD panels, and color filters for LCDs, require photolithography for processing. With the increasing demands for miniaturization, thinness, high density, and multilayer construction, photolithography equipment must possess high resolution and high-precision multilayer alignment capabilities. Because some substrates are prone to stretching due to their material properties, especially since certain substrate materials have different structural characteristics in the width and length directions, the amount of stretching varies in different directions after multiple processing steps. Therefore, under the requirements of high resolution and high precision, the stretching and anisotropic stretching of these substrates become significant factors, necessitating the use of projection lithography equipment with projection magnification adjustment and anisotropic projection magnification adjustment capabilities to address and absorb these variations. Summary of the Invention

[0003] The purpose of this 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 projection magnification.

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

[0005] The first aspect of this invention provides a magnification-adjustable projection imaging optical system, comprising a first lens group, an aperture stop, and a second lens group arranged sequentially from the object plane to the image plane. A cylindrical lens group is disposed between the object plane and the first lens group, or between the image plane and the second lens group. The cylindrical lens group consists of a first cylindrical lens with positive optical power and a second cylindrical lens with negative optical power. The generatrix of the first cylindrical lens and the generatrix of the second cylindrical lens are parallel to each other and both extend along a first direction. By adjusting the distance between the first and second cylindrical lenses along the optical axis, the projection magnification of the image plane along a second direction changes, while the projection magnification of the image plane along the first direction remains unchanged. Both the first and second directions are parallel to the image plane, and the second direction is perpendicular to the first direction.

[0006] The adjustable magnification projection imaging optical system satisfies the following 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] 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 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 distance between the first cylindrical lens and the second cylindrical lens along the optical axis, NA is the numerical aperture of the object plane when the cylindrical lens group is disposed between the object plane and the first lens group, and NA is the numerical aperture of the image plane when the cylindrical lens group is disposed between the image plane and the second lens group.

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

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

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

[0016] In one embodiment, the magnification-adjustable projection imaging optical system comprises 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 disposed between the object plane and the first lens group, the distance between the cylindrical lens group and the first lens group is less than the distance between the cylindrical lens group and the object plane; when the cylindrical lens group is disposed between the image plane and the second lens group, the distance between the cylindrical lens group and the second lens group is less than the distance between the cylindrical lens group and the image plane.

[0019] In one embodiment, when the lens in the first or second lens group moves along the optical axis, the projection magnification of the image plane along the first and second directions is changed by an equal amount, thereby allowing it to be used in conjunction with a cylindrical lens group to change the projection magnification of the image plane.

[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 effects brought by the technical solution provided by the present invention are 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 the different stretching characteristics of the substrate, and the functions of high resolution and high-precision multi-layer alignment of the lithography apparatus can be achieved. 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 the description of the embodiments or the prior art. Obviously, the drawings in the following description 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 by an embodiment of the present invention;

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

[0026] Figure 3 A rear view schematic diagram of the cylindrical lens group provided by 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] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0031] In one embodiment of the present invention, a magnification-adjustable projection imaging optical system is provided. This magnification-adjustable projection imaging optical system consists of 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 disposed between the image plane P2 and the second lens group G2. The light beam emitted from the object plane P1 passes through the first lens group G1, the second lens group G2, and the cylindrical lens group in sequence 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 less than the distance between the cylindrical lens group and the image plane P2. In other embodiments, the cylindrical lens group can also be disposed 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 less than the distance between the cylindrical lens group and the object plane P1.

[0032] The cylindrical lens group consists of a first cylindrical lens C1 with positive optical power and a second cylindrical lens C2 with negative optical power. The generatrix of the first cylindrical lens C1 is parallel to the generatrix of the second cylindrical lens C2. The first cylindrical lens C1 has a first plane and a first curved surface, and the second cylindrical lens C2 has a second plane and a second curved surface. In other embodiments, the first cylindrical lens C1 may be configured to have two curved surfaces, and / or the second cylindrical lens C2 may be configured to have two curved surfaces. Both the first and second curved surfaces are quadratic surfaces, and the first and second curved surfaces are adjacent to each other, with the first and second curved surfaces having the same equation or being proportional. Both the first and second planes 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, 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 generatrix of the first cylindrical lens C1 and the generatrix of 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 rotation axis line direction, 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 relational expressions:

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

[0038] 0 < |(fy1 + fy2)| / (fy1 - fy2) < 0.1; by restricting this relational expression, the first cylindrical lens C1 and the second cylindrical lens C2 will not have significant phase differences, and the optical performance will not degrade.

[0039] fy1 / Hy > 15, preferably, 200 > fy1 / Hy > 35; by restricting this relational expression, the first cylindrical lens C1 and the second cylindrical lens C2 will not have significant phase differences, and the optical performance will not degrade.

[0040] 0 < t / (fy1 - fy(2)) < 0.005; by restricting this relational expression, the first cylindrical lens C1 and the second cylindrical lens C2 will not have significant phase differences, the optical performance will not degrade, and a large zoom effect can be achieved.

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

[0042] Where WD is the distance from the cylindrical lens group to the adjacent image plane P2 in mm, Hy is the maximum height of the adjacent image plane P2 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 in mm, respectively, t is the distance 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 adjacent image plane P2 of the cylindrical lens group.

[0043] In other embodiments, when the cylindrical lens group is positioned 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 adjacent object plane P1 along the first direction X, and NA is the numerical aperture of the adjacent object plane P1.

[0044] In the adjustable projection imaging optical system 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 an equal 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 adjustable projection imaging optical system of the present invention can be applied in a photolithography device. The photolithography device includes an optical mask located at the object plane P1 and a substrate coated with photosensitive material located at the image plane P2. The photolithography device uses the adjustable projection imaging optical system to project the image on the optical mask onto the substrate. Thus, the projection magnification can be adjusted according to the different material properties of the substrate by adjusting the distance between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis. It can also rotate the cylindrical lens group around the optical axis according to the expansion and contraction direction of the substrate to ensure that the direction of magnification correction is consistent with the actual required direction.

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

[0047] Example 1

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

[0049] Table 1

[0050] Optical parameters numerical values 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 adjustable projection imaging optical system in this embodiment is shown in Table 2 below:

[0052] Table 2

[0053]

[0054] In Table 2, the negative sign indicates that the distance between the first cylindrical lens and the second cylindrical lens has decreased.

[0055] Based on the optical parameters in Tables 1 and 2, the numerical values ​​of the relationships 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 The image shows the MTF (Modulation Transfer Function) plot of the magnification-adjustable projection imaging optical system in Example 1. The distance between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis changes by -4 mm. The horizontal axis represents spatial frequency, measured in line pairs per millimeter (lp / mm), where the number of line pairs that can be resolved per millimeter is the resolution value. The vertical axis represents the modulation transfer function (MTF), a quantitative description of lens resolution. It indicates the magnitude of contrast; a smaller modulation degree indicates smaller contrast, and if the contrast is completely eliminated, the modulation degree is 0. The closer the MTF value is to 1, the better the lens performance. Figure 4 As can be seen, in the field of view of the magnification-adjustable projection imaging optical system in this embodiment, the MTF values ​​of the 0 field of view, 0.5 field of view, and the maximum field of view are all close to the diffraction limit (e.g., Figure 4 As shown in TSDIFF LIMIT, this means that the magnification-adjustable projection imaging optical system of this embodiment can achieve an MTF value close to the diffraction limit of physical optics in most fields of view over a wide visible light spectrum, meaning that 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 specific configuration of the magnification-adjustable projection imaging optical system in this embodiment is as follows: Figure 1 As shown, the specific optical parameters are listed in Table 4 below:

[0061] Table 4

[0062] Optical parameters numerical values 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 adjustable projection imaging optical system in this embodiment is shown in Table 2 below:

[0064] Table 5

[0065]

[0066]

[0067] In Table 5, the negative sign indicates that the distance between the first cylindrical lens and the second cylindrical lens has decreased.

[0068] Based on the optical parameters in Tables 4 and 5, the numerical values ​​of the relationships 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 The image shows the MTF (Modulation Transfer Function) plot of the magnification-adjustable projection imaging optical system in Example 2. The distance between the first cylindrical lens C1 and the second cylindrical lens C2 along the optical axis changes by -4 mm. The horizontal axis represents spatial frequency, measured in line pairs per millimeter (lp / mm), where the number of line pairs that can be resolved per millimeter is the resolution value. The vertical axis represents the modulation transfer function (MTF), a quantitative description of lens resolution. It indicates the magnitude of contrast; a smaller modulation degree indicates smaller contrast, and if the contrast is completely eliminated, the modulation degree is 0. The closer the MTF value is to 1, the better the lens performance. Figure 5 As can be seen, in the field of view of the magnification-adjustable projection imaging optical system in this embodiment, the MTF values ​​of the 0 field of view, 0.5 field of view, and the maximum field of view are all close to the diffraction limit (e.g., Figure 5 As shown in TSDIFF LIMIT, this means that the magnification-adjustable projection imaging optical system of this embodiment can achieve an MTF value close to the diffraction limit of physical optics in most fields of view over a wide visible light spectrum, meaning that 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 document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this 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 consists 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 generatrix of the first cylindrical lens and the generatrix of 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 magnification-adjustable projection imaging optical system 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. The first curved surface and the second curved surface are both aspherical surfaces. The first curved surface and the second curved surface are arranged adjacent to each other.

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

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

8. The magnification-adjustable projection imaging optical system 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 magnification-adjustable projection imaging optical system 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. The cylindrical lens group is arranged on the rotating platform.

10. A photolithography apparatus, characterized in that: The lithography apparatus includes a magnified projection imaging optical system as described in any one of claims 1-9, an optical mask located at the object plane, and a substrate coated with a photosensitive material located at the image plane. The lithography apparatus uses the magnified projection imaging optical system to project an image on the optical mask onto the substrate.

Images