High-precision photoetching lens with compensation type optical wedge lens group for focusing
By introducing a compensation module into the lithography lens and adjusting its inclination angle and position, the astigmatism error problem caused by the air-spaced wedge lens in the lithography lens is solved, the accuracy and flexibility of the lithography lens are improved, and the high Consistency of line width and line spacing of the accuracy pattern.
Patent Information
- Application Number
- CN202421147572.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-24
AI Technical Summary
The existing lithography lenses are directly placed in wedge-shaped mirror groups with air spacing. Due to the single direction of the air spacing, the positions of the meridian image plane and the sagittal image plane are not coplanar, causing astigmatism errors and affecting high accuracy. The line width and line spacing consistency of the pattern.
Design a high-precision lithography lens with compensating wedge mirror group focusing. By introducing a compensation module into the lens, it adjusts its inclination angle and distance from the first lens, which is opposite to the inclined angle of the wedge mirror group, so as to Solve astigmatism error problem. The compensation module can be set between the object surface and the lithographic lens or the front end inside the lens, with an adjustable inclination angle and a thickness of 2.0mm-3.0mm.
有效解决了像散误差问题,提高了光刻镜头的精准度和灵活度,使子午像面和弧矢像面成像点位置共面,确保高精度图案中横线和竖线的线宽、线 Distance consistency.
Smart Images
Figure CN222259685U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical process design, in particular to a high-precision photolithography lens with a compensating optical wedge lens group for focusing. Background Art
[0002] Direct write lithography is a maskless lithography technology that can achieve high-precision writing of arbitrary graphics by simply controlling the intensity of light and scanning the writing path. It is simpler and cheaper than other writing methods, and can achieve high-precision, high-flexibility, and low-cost production. Due to the characteristics of high resolution, low cost, and flexible control, digital micromirror devices (DMDs) have gradually been applied to the field of digital mask lithography. By loading arbitrary graphics on it by a computer and controlling it in real time, a digital mask of complex graphics can be realized. Therefore, digital mask lithography technology based on digital micromirror devices (DMDs) can produce micro-nano structures with complex structures and special shapes.
[0003] When using digital micromirror device (DMD) technology to produce micron-level high-precision patterns, the magnification of the photolithography lens is generally below 1x, that is, the reduction ratio will greatly reduce the working focal depth of the lens. In order to quickly solve the defocus problem caused by the unevenness of the photolithography substrate surface, the current industry practice is to set two wedge prism groups with consistent wedge angles and relative motion under the lens, and a distance of 0.1mm-0.5mm will be left between the two inclined surfaces of the wedge prism group. However, if a wedge lens group with an air spacer is directly placed in a conventional lens, the image point positions of the meridian image plane and the sagittal image plane will not be coplanar due to the single direction of the air spacer, that is, the astigmatism error is introduced, which in turn affects the consistency of the line width and line spacing of the horizontal and vertical lines in the high-precision pattern.
[0004] The utility model provides a high-precision photolithography lens with a compensating wedge lens group for focusing, so as to solve the problem in the prior art that a wedge lens group with an air spacer is directly placed in the lens, and the imaging point positions of the meridian image plane and the sagittal image plane are not coplanar due to the single direction of the air spacer, resulting in astigmatism aberration. Utility Model Content
[0005] The utility model aims to provide a high-precision lithography lens with a compensating wedge lens group for focusing, so as to solve the problem in the prior art that a wedge lens group with an air spacer is directly placed in the lens, and the positions of the imaging points on the meridional image plane and the sagittal image plane are not coplanar due to the single direction of the air spacer, resulting in astigmatism aberration.
[0006] The technical solution of the utility model is: a high-precision lithography lens with a compensating wedge lens group focusing, comprising: an object plane, a compensation module, a lithography lens, a wedge lens group, and an imaging plane; the object plane, the lithography lens, the wedge lens group and the imaging plane are arranged on the same ray and in sequence.
[0007] Preferably, the compensation module is arranged between the object plane and the photolithography lens or at the front end inside the photolithography lens.
[0008] Preferably, the compensation module is flat glass.
[0009] Preferably, when the compensation module is arranged between the object plane and the lithography lens, the distance between the compensation module and the first lens of the lithography lens is 20 mm-10 mm;
[0010] When the compensation module is disposed at the front end of the photolithography lens, the distance between the compensation module and the first lens of the photolithography lens is 20 mm-50 mm.
[0011] Preferably, the direction of the inclination angle of the compensation module is opposite to the direction of the inclined surface angle of the wedge-shaped mirror assembly.
[0012] Preferably, the inclination angle of the compensation module is adjustable;
[0013] When the compensation module is arranged between the object plane and the photolithography lens, the inclination angle of the compensation module is 1.0°-18.50°;
[0014] When the compensation module is arranged at the front end of the photolithography lens, the inclination angle of the compensation module is 7.75°-29.26°.
[0015] Preferably, when the compensation module is arranged between the object plane and the photolithography lens, the inclination angle of the compensation module is 4.79°-10.65°;
[0016] When the compensation module is arranged at the front end of the photolithography lens, the inclination angle of the compensation module is 12.77°-21.58°.
[0017] Preferably, the thickness of the compensation module is 2.0 mm-3.0 mm.
[0018] Preferably, the thickness of the compensation module is 2.5 mm.
[0019] Compared with the prior art, the advantages of the utility model are:
[0020] (1) The utility model provides a high-precision photolithography lens with a compensating wedge lens group for focusing. A wedge lens group is added to a conventional lens, and a compensation module is introduced to solve the problem of astigmatism and aberration caused by directly placing a wedge lens group with an air spacer in the lens in the prior art, thereby improving the accuracy and flexibility of the photolithography lens.
[0021] (2) The utility model provides a high-precision lithography lens with a compensating wedge lens group for focusing. The compensation module is arranged between the object plane and the lithography lens or at the front end inside the lithography lens. By adjusting the inclination angle of the compensation module and the distance between the compensation module and the first lens, the problem of directly placing a wedge lens group with an air spacer in a conventional lens, which causes the positions of the imaging points on the meridian image plane and the sagittal image plane to be non-coplanar due to the single direction of the air spacer, and causes astigmatism error, is solved. This is conducive to improving the consistency of the line width and line spacing of horizontal and vertical lines in high-precision patterns. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The utility model is further described below in conjunction with the accompanying drawings and embodiments:
[0023] Figure 1 This is a schematic diagram of the structure in which the compensation module of the utility model is arranged between the object plane and the photolithography lens;
[0024] Figure 2 It is a structural schematic diagram of the wedge-shaped mirror assembly of the utility model;
[0025] Figure 3 A field curvature diagram when the compensation module of the utility model is arranged between the object plane and the photolithography lens;
[0026] Figure 4 This is a schematic diagram of the structure in which the compensation module of the utility model is arranged at the front end inside the lithography lens;
[0027] Figure 5 A field curvature diagram when the compensation module of the utility model is arranged at the front end inside the lithography lens;
[0028] Figure 6 This is a schematic diagram of the structure of the utility model without the compensation module;
[0029] Figure 7 This is a field curvature diagram when the compensation module is not provided in the utility model;
[0030] Among them: 1. object plane; 2. compensation module; 3. photolithography lens; 4. wedge-shaped lens group; 5. imaging plane; 31. first lens. DETAILED DESCRIPTION
[0031] The following is a further detailed description of the present invention in conjunction with specific embodiments:
[0032] Example 1
[0033] like Figure 1 As shown, a high-precision lithography lens with a compensating wedge lens group focusing includes: an object plane 1, a compensation module 2, a lithography lens 3, a wedge lens group 4 and an imaging plane 5; the object plane 1, the lithography lens 3, the wedge lens group 4 and the imaging plane 5 are arranged on the same ray and arranged in sequence. Figure 2 As shown, an air gap of 0.1-0.5 mm is left between the two inclined surfaces of the wedge-shaped lens group. The compensation module 2 is arranged between the object plane 1 and the photolithography lens 3. The thickness of the compensation module is 2.0 mm-3.0 mm; the distance between the compensation module 2 and the object plane 1 is 90-100 mm, and the distance between the compensation module 2 and the first lens 31 is 20-10 mm; the inclination angle of the compensation module is 1.0°-18.50°, and the direction of the inclination angle of the compensation module is opposite to the direction of the angle of the inclined surface of the wedge-shaped lens group.
[0034] Table 1: Basic parameters of Example 1
[0035]
[0036]
[0037] Under the parameter conditions shown in Table 1, the imaging effect of the high-precision lithography lens with compensating wedge lens group focusing is tested. The thickness, tilt angle of the compensation module 2 and the distance between the compensation module and the first lens are adjusted to make the image points on the meridian image plane and the sagittal image plane coplanar. When the thickness of the compensation module 2 is 2.5mm, the tilt angle is 4.79°-10.65°, and the distance between the compensation module 2 and the first lens 31 is 20mm-10mm, the astigmatism error of the lithography lens can be made smaller and the accuracy is higher. Figure 3 As shown, the dotted line is the field curvature in the sagittal direction, and the solid line is the field curvature in the meridional direction. The field curvature in the sagittal direction coincides with the field curvature in the meridional direction, that is, the imaging point positions of the meridional image plane and the sagittal image plane are coplanar, and there is no astigmatism error; and the field curvature value is less than 10um, which is within the range of parameter requirements.
[0038] Example 2
[0039] like Figure 4As shown, a high-precision lithography lens with a compensating wedge lens group focusing includes: an object plane 1, a compensation module 2, a lithography lens 3, a wedge lens group 4 and an imaging plane 5; the object plane 1, the lithography lens 3, the wedge lens group 4 and the imaging plane 5 are arranged on the same ray and arranged in sequence; the compensation module 2 is arranged at the front end of the inside of the lithography lens 3. The thickness of the compensation module is 2.0mm-3.0mm, and the distance between the compensation module 2 and the first lens 31 is 20-50mm; the inclination angle of the compensation module is 7.75°-29.26°, and the direction of the inclination angle of the compensation module is opposite to the direction of the inclined angle of the wedge lens group.
[0040] Under the same parameter conditions as in Example 1, the imaging effect of the high-precision lithography lens with compensating wedge lens group focusing is tested. When the thickness of the compensation module 2 is 2.0 mm-3.0 mm, the tilt angle is 12.77°-21.58°, and the distance between the compensation module 2 and the first lens 31 is 20 mm-50 mm, the astigmatism error of the high-precision lithography lens can be made smaller and the accuracy is higher. Figure 5 As shown, the field curvature in the sagittal direction is basically consistent with the field curvature in the meridional direction, that is, the imaging point positions of the meridional image plane and the sagittal image plane are coplanar, and there is no astigmatism error; and the field curvature value is less than 10um, which is within the range of parameter requirements.
[0041] Comparative Example 1
[0042] like Figure 6 As shown, a high-precision lithography lens comprises: an object plane 1, a lithography lens 3, a wedge-shaped lens group 4 and an imaging plane 5; and the object plane 1, the lithography lens 3, the wedge-shaped lens group 4 and the imaging plane 5 are arranged on the same ray and arranged in sequence.
[0043] Under the same parameter conditions as in Example 1, the imaging effect of the high-precision photolithography lens was tested. Figure 7 As shown, the dotted line is the field curvature in the sagittal direction, and the solid line is the field curvature in the meridional direction. The field curvature in the sagittal direction does not coincide with the field curvature in the meridional direction, that is, the imaging point positions of the meridional image plane and the sagittal image plane are not coplanar, and there is an obvious astigmatism error.
[0044] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.
Claims
1. A high-precision lithography lens with a compensating wedge lens group for focusing, characterized in that: include: Object plane (1), compensation module (2), photolithography lens (3), wedge lens group (4), imaging plane (5); The object plane (1), the photolithography lens (3), the wedge-shaped lens group (4) and the imaging plane (5) are arranged on the same ray and arranged in sequence; the compensation module (2) is arranged between the object plane (1) and the photolithography lens (3) or at the front end inside the photolithography lens (3); The direction of the inclination angle of the compensation module (2) is opposite to the direction of the inclined surface angle of the wedge-shaped mirror group (4); the inclination angle of the compensation module (2) is adjustable; When the compensation module (2) is arranged between the object plane (1) and the photolithography lens (3), the distance between the compensation module (2) and the first lens (31) of the photolithography lens (3) is 20 mm-10 mm; the inclination angle of the compensation module (2) is 1.0°-18.50°; When the compensation module (2) is arranged at the front end of the photolithography lens (3), the distance between the compensation module and the first lens (31) of the photolithography lens (3) is 20 mm-50 mm; and the inclination angle of the compensation module (2) is 7.75°-29.26°.
2. The high-precision lithography lens with compensating wedge lens group focusing according to claim 1, characterized in that: The compensation module (2) is flat glass.
3. The high-precision lithography lens with compensating wedge lens group focusing according to claim 1, characterized in that: When the compensation module (2) is arranged between the object plane (1) and the photolithography lens (3), the tilt angle of the compensation module (2) is 4.79°-10.65°; When the compensation module (2) is arranged at the front end inside the photolithography lens (3), the inclination angle of the compensation module (2) is 12.77°-21.58°.
4. The high-precision lithography lens with compensating wedge lens group focusing according to claim 1, characterized in that: The thickness of the compensation module (2) is 2.0 mm-3.0 mm.
5. The high-precision lithography lens with compensating wedge lens group focusing according to claim 4, characterized in that: The thickness of the compensation module (2) is 2.5 mm.