Optical system and method

Abstract

Techniques for magnification compensation and / or beam steering in optical systems are disclosed. An optical system may include a lens system for receiving first radiation associated with an object and directing second radiation associated with an image of the object toward an image plane. The lens system may include a set of lenses and an actuator system for selectively adjusting the set of lenses to symmetrically adjust magnification associated with the image in a first direction and a second direction. The lens system may also include a beam directing lens for directing the first radiation to provide the second radiation. In some examples, the lens system may also include a second set of lenses, where the actuator system may also selectively adjust the second set of lenses to adjust the magnification in the first direction or the second direction. Related methods are also disclosed.

Description

[0001] This application is a divisional application of the PCT international invention patent application with the application date of June 18, 2018, application number “201880052979.3” and invention name “Magnification compensation and / or beam guidance in optical systems”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 522,062, filed on June 19, 2017, and entitled “MAGNIFICATION COMPENSATION AND / ORBEAM STEERING IN OPTICAL SYSTEMS,” which is incorporated herein by reference in its entirety. Technical Field

[0004] One or more embodiments relate generally to optical systems, and more particularly, the invention relates to, for example, magnification compensation and beam steering in optical systems. Background Art

[0005] The projection system is used to project an object at the object plane onto the image plane. In semiconductor technology, a lithography system can project a pattern on a mask onto a wafer. In some cases, there will be defects between the desired pattern provided by the mask and the actual pattern formed on the wafer. Although some defects may occur randomly, other defects may be attributed to magnification errors. The magnification errors in the x-direction and the y-direction may be different and may be attributed to various reasons, such as one or more robots not placing the die correctly on the wafer, the expansion of the wafer and / or mask (e.g., thermal expansion), the sedimentation of the compound used to mold the die onto the carrier wafer, and / or other reasons. Conventional projection systems may attempt to reduce the magnification error by heating and / or cooling the mask or wafer to adjust (e.g., grow or shrink) the target image. However, this heating and / or cooling takes time (which adversely affects productivity) and cannot be applied to the magnification of different wafers. In addition, heating and cooling generally can only apply symmetrical compensation and are limited by the thermal expansion coefficient of the mask or wafer. Summary of the invention

[0006] In one or more embodiments, an optical system includes a lens system configured to receive first radiation associated with an object and direct second radiation associated with an image of the object toward an image plane. The lens system includes a first set of lenses configured to receive and selectively magnify the first radiation. The lens system also includes an actuator system configured to selectively adjust the first set of lenses to symmetrically adjust the magnification associated with the image along a first direction and a second direction. The lens system also includes a beam steering lens configured to direct the first radiation selectively magnified by the first set of lenses to provide the second radiation based at least on a tilt of the beam steering lens. The tilt of the beam steering lens can be adjusted by the actuator system. The first direction can be orthogonal to the second direction. In some cases, the image plane can be parallel to the object plane. In other cases, the image plane is not parallel to the object plane.

[0007] In one or more aspects, the optical system may also have a lens assembly including a plurality of lenses. The optical system may further include a first prism configured to pass the first radiation to the lens assembly, wherein the first set of lenses is configured to pass the first radiation to the first prism. The optical system may further include a reflector configured to receive the first radiation from the first prism via the plurality of lenses of the lens assembly and reflect the first radiation. The optical system may further include a second prism configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane.

[0008] In some embodiments, the optical system may further include a second set of lenses configured to receive and selectively magnify the first radiation. The actuator system may further be configured to selectively adjust the second set of lenses to adjust the magnification along the first direction or the second direction. The beam directing lens may be configured to direct the first radiation selectively magnified by the first set of lenses and the second set of lenses based at least on the tilt of the beam directing lens to provide the second radiation. The optical system may further have a lens assembly including a plurality of lenses. The optical system may further include a first prism configured to pass the first radiation to the lens assembly. The optical system may further include a reflector configured to receive the first radiation from the first prism through the plurality of lenses of the lens assembly and reflect the first radiation. The optical system may further include a second prism configured to receive the first radiation reflected from the reflector through the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane. The first set of lenses may be configured to pass the first radiation to the first prism. The second prism can be configured to pass the first radiation to the second set of lenses.

[0009] In one or more aspects, the actuator system can be configured to adjust the second set of lenses to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value to the magnification along the second direction. The first magnification compensation value can be different from the second magnification compensation value. The actuator system can be configured to move at least one lens in the first set of lenses from a first position to a second position and / or move at least one lens in the second set of lenses from a third position to a fourth position to adjust the magnification. In some cases, the second set of lenses is a single lens, wherein the actuator system can be configured to bend and / or rotate the single lens to adjust the magnification.

[0010] In one or more embodiments, the optical system is a lithography system. The object may include a pattern of a mask. The image plane may include a wafer. The image may include a projection of the object on the wafer. The optical system may further include a magnification controller configured to generate one or more control signals associated with an adjustment of the magnification based at least on a position of the mask relative to a position of the wafer. The actuator system may be configured to receive the one or more control signals and cause the magnification adjustment in response to the one or more control signals. The optical system may further include a wafer positioning controller configured to adjust a position of the wafer relative to a position of the mask to shift a position of the image on the wafer. In some aspects, the lens system may be configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer. The actuator system may be further configured to adjust the tilt of the beam steering lens in response to the one or more control signals, wherein each portion of the wafer is associated with a corresponding tilt of the beam steering lens.

[0011] In one or more embodiments, a method includes: receiving first radiation associated with an object. The method further includes: directing the first radiation through at least a first set of lenses to obtain selectively magnified first radiation, wherein during directing the first radiation, selectively adjusting the first set of lenses to symmetrically adjust the magnification associated with an image of the object along a first direction and a second direction. The method further includes: directing the selectively amplified first radiation to provide second radiation toward an image plane based at least on a tilt of a beam directing lens. In some aspects, the first set of lenses may include a plurality of lenses, wherein selectively adjusting the first set of lenses may include: adjusting a distance between at least two lenses of the plurality of lenses. The first direction may be orthogonal to the second direction. In some cases, the image plane may be parallel to the object plane. In other cases, the image plane is not parallel to the object plane.

[0012] In one or more aspects, directing the first radiation may include directing the first radiation through at least the first set of lenses and the second set of lenses to obtain the selectively magnified first radiation, wherein during directing the first radiation, the second set of lenses is selectively adjusted to adjust the magnification along the first direction or the second direction. Selectively adjusting the second set of lenses may include selectively adjusting the second set of lenses to apply a first magnification compensation value along the first direction to the magnification and a second magnification compensation value different from the first magnification compensation value along the second direction to the magnification.

[0013] In some embodiments, the method is for a lithography system. The object may include a pattern of a mask. The image plane may include a wafer. The image may include a projection of the object on the wafer. Directing the selectively amplified first radiation may include: projecting each portion of the pattern onto a corresponding portion of the wafer. In some aspects, the method may further include: generating one or more control signals associated with adjustment of the magnification based at least on a position of the mask relative to a position of the wafer, wherein selectively adjusting the first set of lenses is based on the one or more control signals. The method may further include: adjusting a tilt of a beam directing lens in response to the one or more control signals, wherein each portion of the wafer is associated with a corresponding tilt of the beam directing lens.

[0014] In one or more embodiments, an optical system includes a lens system configured to receive first radiation associated with an object and direct second radiation associated with an image of the object toward an image plane. The lens system includes a first set of lenses configured to receive and selectively magnify the first radiation. The lens system also includes a second set of lenses configured to receive and selectively magnify the first radiation. The lens system also includes an actuator system configured to selectively adjust the first set of lenses to adjust a magnification associated with the image symmetrically along a first direction and a second direction. The actuator system is also configured to selectively adjust the second set of lenses to adjust the magnification along at least one of the first direction or the second direction. In one or more aspects, the lens system may further include a beam steering lens configured to direct the first radiation to provide the second radiation based at least on a tilt of the beam steering lens. The tilt of the beam steering lens may be adjusted by the actuator system.

[0015] In some embodiments, the optical system further has a lens assembly including a plurality of lenses. The optical system further includes a first prism configured to pass the first radiation to the lens assembly. The optical system further includes a reflector configured to receive the first radiation from the first prism via the plurality of lenses of the lens assembly and reflect the first radiation. The optical system further includes a second prism configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane. The first set of lenses may be configured to pass the first radiation to the first prism, and the second prism may be configured to pass the first radiation to the second set of lenses.

[0016] In some aspects, the actuator system can be configured to adjust the second set of lenses to apply a first magnification compensation value along the first direction to the magnification and a second magnification compensation value along the second direction to the magnification. The first magnification compensation value can be different from the second magnification compensation value. In some cases, the first direction can be orthogonal to the second direction. In some implementations, the actuator system can be configured to move at least one lens in the first set of lenses from a first position to a second position and / or move at least one lens in the second set of lenses from a third position to a fourth position to adjust the magnification.

[0017] In some embodiments, the optical system may be a lithography system. The object may include a pattern of a mask. The image plane may include a wafer. The image may include a projection of the object on the wafer. The optical system may include a beam steering lens configured to provide the second radiation based at least on a tilt of the beam steering lens. The lens system may be configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer. The actuator system may be further configured to adjust the tilt of the beam steering lens in response to one or more control signals. Each portion of the wafer may be associated with a corresponding tilt of the beam steering lens.

[0018] In one or more embodiments, a method includes: receiving radiation associated with an object. The method includes: directing the radiation toward an image plane through at least a first set of lenses and a second set of lenses. The method includes: during the directing, selectively adjusting the first set of lenses to symmetrically adjust a magnification associated with an image of the object along a first direction and a second direction; and selectively adjusting the second set of lenses to adjust the magnification along the first direction or the second direction.

[0019] In some embodiments, such as for a lithography system, the object comprises a pattern of a mask, the image plane may comprise a wafer, the image may comprise a projection of the object on the wafer, and directing the radiation comprises: projecting each portion of the pattern onto a corresponding portion of the wafer. The method may further comprise: generating one or more control signals based at least on a position of the mask relative to a position of the wafer. The method may further comprise: adjusting a tilt of a beam directing lens in response to the one or more control signals. Each portion of the wafer may be associated with a corresponding tilt of the beam directing lens.

[0020] In one or more embodiments, a method includes providing a first group of lenses of a lens system and a second group of lenses of the lens system. The method further includes receiving, by the lens system, first radiation associated with an object. The method further includes directing the first radiation through the first group of lenses to symmetrically magnify the first radiation along a first direction and a second direction orthogonal to the first direction. The method further includes directing the first radiation through the second group of lenses to magnify the first radiation along the first direction or the second direction. The method further includes directing second radiation associated with an image of the object toward an image plane, wherein the second radiation is based on the first radiation that has passed through the first group of lenses and the second group of lenses.

[0021] The scope of the present invention is defined by the technical solutions incorporated into this section by reference. Those skilled in the art will more fully understand the embodiments of the present invention and realize additional advantages thereof by considering the following detailed description of one or more embodiments. Reference will be made to the accompanying drawings which will first be briefly described. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 An optical system according to one or more embodiments of the present invention is shown.

[0023] Figure 2A and Figure 2B Symmetrical magnifying lens sets, asymmetric magnifying lens sets, and associated mounting systems and actuator systems according to one or more embodiments of the present invention are shown.

[0024] FIG. 3A to FIG. 3C An example of relative positioning of lenses of a symmetric magnifying lens set according to one or more embodiments of the present invention is shown.

[0025] Figure 4A An exemplary cross-sectional view of a symmetrical magnifying lens assembly according to one or more embodiments of the present invention is shown.

[0026] Figure 4B An exemplary cross-sectional view of an asymmetric magnifying lens assembly according to one or more embodiments of the present invention is shown.

[0027] Figure 5A lens binary of an optical system according to one or more embodiments of the present invention is shown.

[0028] Figure 6 An asymmetric magnifying lens according to one or more embodiments of the present invention is shown.

[0029] Figure 7 A beam directing lens of an optical system is shown in accordance with one or more embodiments of the present invention.

[0030] Figure 8 A beam directing lens and associated components are shown in accordance with one or more embodiments of the present invention.

[0031] Fig. 9 A lithography system according to one or more embodiments of the present invention is shown.

[0032] Fig.10 A scanning lithography machine or a portion thereof according to one or more embodiments of the present invention is shown.

[0033] Fig.11A and Fig. 11B An example of an exposure field of a scanning lithography machine is shown.

[0034] Fig.12 The actual and desired die sizes and locations of various dies on the wafer are shown.

[0035] Fig.13A and Fig. 13B supply Fig.12 Magnified image of the grains.

[0036] FIG. 14A to FIG. 14C The tilt of the beam-directing lens of the optical system is shown while the wafer is being moved in accordance with one or more embodiments of the present invention.

[0037] FIG. 15A to FIG. 15D The positions of the scanner exposure fields and the associated wafer position shifts are shown in accordance with one or more embodiments of the present invention.

[0038] Embodiments of the present invention and their advantages are best understood by referring to the following detailed description.It should be appreciated that like reference numerals are used to identify like components illustrated in one or more of the figures. DETAILED DESCRIPTION

[0039] The detailed description to be described below is intended as a description of various configurations of the present technology and is not intended to represent the only configuration in which the present technology can be practiced. The accompanying drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for providing a thorough understanding of the present invention. However, it should be clear and understood by those skilled in the art that the present invention is not limited to the specific details described herein, but can be practiced using one or more embodiments. In one or more instances, structures and components are shown in block diagram form so as not to make the concept of the present invention unclear. One or more embodiments of the present invention are illustrated by one or more figures and / or described in conjunction with one or more figures and described in the claims.

[0040] Various techniques are provided to facilitate magnification compensation and beam steering in an optical system. Magnification compensation can be used to compensate for magnification errors such as due to incorrect placement of a die on a wafer, wafer and / or mask expansion, and / or other situations. In some embodiments, an optical system may include a lens group for providing magnification compensation (e.g., also referred to as magnification correction or magnification adjustment). The lens group used for magnification compensation may be collectively referred to as a magnification compensation lens. Magnification compensation can be used to adjust (e.g., change, correct, compensate) the nominal magnification of the optical system. In this regard, the nominal magnification of the optical system may refer to the magnification of the optical system without any magnification compensation provided by the magnification compensation lens. In one aspect, since the magnification compensation lens effectively magnifies the object, the magnification compensation provided by the magnification compensation lens may be simply referred to as magnification. As used herein, the magnification provided by the magnification compensation lens may be a positive magnification (e.g., making the image larger relative to a situation where no magnification is provided), a negative magnification (e.g., making the image smaller relative to a situation where no magnification is provided), or a zero magnification (e.g., the magnification compensation lens does not magnify or reduce). In one aspect, magnification may refer to the ratio of the image size at the image plane (eg, also referred to as the focal plane) to the object size at the object plane.

[0041] The first group of lenses can provide the same magnification compensation along both the x-direction and the y-direction orthogonal to the x-direction. This magnification compensation can be referred to as symmetric magnification compensation or rotationally symmetric magnification compensation. The first group of lenses can be referred to as a symmetric magnification lens group or can be implemented by a symmetric magnification lens group. The symmetric magnification lens group can include one or more symmetric lenses, such as one or more spherical lenses. The second group of lenses can provide different magnification compensation along the x-direction and / or the y-direction. This magnification compensation can be referred to as single-axis magnification compensation or asymmetric magnification compensation. The second group of lenses can be referred to as an asymmetric magnification lens group. The asymmetric magnification lens group can include one or more asymmetric lenses, such as one or more cylindrical lenses. Although the optical system described in various embodiments of the present invention includes a group of lenses for symmetric magnification compensation and another group of lenses for asymmetric magnification compensation, in other embodiments, the optical system may include fewer lens groups, additional lens groups, and / or a combination of different lens groups to provide symmetric magnification compensation and / or asymmetric magnification compensation. For example, in one embodiment, the optical system may include a single group of lenses for symmetric magnification compensation (e.g., without a group of lenses for asymmetric magnification compensation).

[0042] Each set of lenses may include one or more lenses (e.g., one or more convex lenses and / or one or more concave lenses). In one aspect, the first set of lenses may include three lenses (e.g., also referred to as a lens triplet). For example, the three lenses may include two plano-concave lenses and one bi-convex lens. For another example, the three lenses may include two plano-convex lenses and one bi-concave lens.

[0043] The optical system may include an actuator system to facilitate adjustment of the magnification compensation provided by the magnification compensation lens. For example, if a set of lenses includes two or more lenses, the magnification compensation provided by the set of lenses may be adjusted by adjusting the size of a gap (e.g., an air gap) between at least two lenses in the lens set. In this regard, the actuator system may move one or more lenses of the lens set to adjust the size of the gap. For another example, if a set of lenses includes a single lens, the magnification compensation provided by the single lens may be adjusted by bending (e.g., deforming) the single lens (e.g., by applying a force using an actuator system).

[0044] In one or more embodiments, the optical system may include one or more beam guiding components to guide a beam to the image plane. The beam guiding component may be or may be referred to as a beam guiding lens, a beam guiding window, a tilting lens, a tilting window, and / or variations thereof. The beam guiding component(s) may receive the beam that has propagated through the first set of lenses and the second set of lenses.

[0045] Various embodiments may be used to control the magnification of an optical system, such as a telecentric optical system. In some embodiments, the optical system may be, may include, or may be part of a semiconductor lithography system, such as a Wynn-Dyson 1:1 (e.g., unity magnification) scanning projection system and / or other lithography image system; and / or substantially any projection lens system for projecting an image of an object at an object plane onto an image plane. In some aspects, for a projection lens system in which the object and image are telecentric, the magnification cannot be changed by changing the object or image distance. In some cases, large radius convex and concave lenses may be employed in the projection lens object telecentric space or the image telecentric space to provide magnification compensation. Using a magnification compensation lens in a projection lens system allows for adjustment of the magnification provided by the optical system. In some cases, adding a large radius magnification compensation lens to a projection lens system has a smaller impact on image performance (e.g., relative to adding a smaller magnification compensation lens). Magnification compensation and beam steering may be performed quickly to maintain productivity and reduce magnification errors. Furthermore, these techniques allow for asymmetric magnification compensation, where different magnification compensation is provided for different directions.

[0046] Now turning to the attached figure, Figure 1 An optical system 100 is shown in accordance with one or more embodiments of the present invention. However, not all depicted components are necessarily required, and one or more embodiments may include Figure 1 Additional components not shown in the drawings. Changes may be made to the configuration and type of components without departing from the spirit or scope of the claims set forth herein. Additional, fewer and / or different components may be provided. In one embodiment, the optical system 100 may be used to provide optical asymmetric magnification and beam steering.

[0047] The various optical components of the optical system 100 reflect and / or refract radiation that is incident on or propagates through the optical components. In some aspects, the radiation is electromagnetic (EM) radiation. EM radiation may generally refer to any radiation in the EM spectrum and may be referred to as an EM radiation beam, an EM beam, light, a light beam, or variations thereof (e.g., an EM beam). The term "light" may include visible light, infrared light, ultraviolet (UV) light, or substantially any portion of the EM spectrum. In some cases, light-transmitting surfaces of the various components of the optical system 100 may be coated with a material to increase their light transmittance. Alternatively and / or in addition, reflective surfaces of the various components of the optical system 100 may be coated to increase reflectivity.

[0048] In one embodiment, such as Figure 1 As shown in FIG. 1 , the object plane 105 is parallel to the image plane 110 and is along the z direction (eg, Figure 1The object plane 105 and the image plane 110 are spaced apart in the vertical direction in the optical system 100. An example distance between the object plane 105 and the image plane 110 is about 8.58 inches. The object plane 105 and the image plane 110 are disposed on opposite sides of the optical system 100. The radiation source ( Figure 1 105 to the optical system 100. For example, the radiation source may be a light source, such as a UV light source. The light beam 115 may propagate through various components of the optical system 100 and be output as a light beam 120 to the image plane 110. In this manner, an image of an object at the object plane 105 may be projected onto the image plane 110. In other embodiments, the object plane and the image plane are at a defined angle to each other (e.g., the object plane and the image plane are not parallel to each other).

[0049] In one embodiment, for example, when optical system 100 is configured as part of a lithography system (e.g., a semiconductor lithography system), a reticle, mask, or substantially any structure having a microelectronic pattern defined thereon (e.g., on a sheet / film of material) may be configured as an object at object plane 105 for projection onto image plane 110. A wafer on which the structure is to be fabricated may be configured at image plane 110 to receive a projection of the microelectronic pattern. In this regard, light beam 115 propagates through the object (e.g., reticle, mask, etc.) at object plane 105 and is directed to image plane 110 by optical system 100. In some cases, optical system 100 may apply a magnification (e.g., positive or negative magnification) to light beam 115. In one aspect, magnification may refer to a ratio of an image size at image plane 110 to an object size at object plane 105.

[0050] In some embodiments, optical system 100 includes symmetrical magnifying lens group 125, asymmetrical magnifying lens group 130, beam guiding lens 135, prisms 140 and 145, lens assembly 150, and reflector 155. In some cases, Figure 1 The dashed box in can represent a housing for optical system 100. For example, the housing can include windows and / or materials that allow light beam 115 to pass into (e.g., couple into) optical system 100. In some aspects, asymmetric magnifying lens set 130 is optional, as will be further described herein.

[0051] Lens assembly 150 includes lenses 160, 165, 170, and 175. Lenses 160, 165, 170, and 175 may be plano-convex lenses, concave-convex lenses, concave-convex lenses, and meniscus lenses, respectively. In one aspect, reflector 155 and lenses 160, 165, 170, and 175 are positioned (e.g., mounted) along an optical axis of optical system 100. The optical axis of optical system 100 may refer to an axis through which a light beam may pass without refraction. In one aspect, lenses 160, 165, 170, and 175 are made of materials and / or positioned to jointly correct for chromatic aberration, field aberration, and / or astigmatism. Lenses 160, 165, 170, and 175 may be made of the same or different glass types.

[0052] Lens 160 has a flat surface facing away from reflector 155 and a convex surface facing reflector 155. The convex surface of lens 160 may face the concave surface of lens 165. In some cases, the convex surface of lens 160 may be nested into the concave surface of lens 165. For example, lenses 160 and 165 may be bonded together to form a doublet. Lens 165 has a convex surface facing reflector 155. The curvature of the convex surface of lens 165 may be less than the curvature of the concave surface of lens 165 and less than the curvature of the convex surface of lens 160.

[0053] Lens 170 has a convex surface facing away from reflector 155 and facing lens 160 and a concave surface facing reflector 155. Lens 175 has a convex surface facing reflector 155 and a concave surface facing away from reflector 155 and facing lens 160. In some cases, the curvature of the surface of lens 175 is less than the curvature of the surface of lens 165 and the curvature of the surface of lens 170.

[0054] Reflector 155 has a concave surface 180 centered on the optical axis of optical system 100 and facing lens 160. Concave surface 180 may be spherical or slightly aspherical (e.g., also referred to as substantially spherical). Concave surface 180 may be slightly spherical (e.g., slightly ellipsoidal) to help correct high-order chromatic aberrations of a large field. In one aspect, the shape of concave surface 180 and lenses 160, 165, 170, and 175 of lens assembly 150 and their positioning / arrangement may facilitate correction of chromatic aberrations. It should be noted that example properties of lenses 160, 165, 170, and 175 are provided above. Other combinations of lenses and / or lens properties may be utilized. In an embodiment, lenses 160, 165, 170, and 175 may be spherical or aspherical. Other embodiments of Dyson lenses are known to those skilled in the art and may be used with the limited magnification and beam steering described in the present invention.

[0055] Prism 140 (also referred to as a roof prism, for example) and prism 145 (also referred to as a folding prism, for example) are located between object plane 105 and image plane 110. An example distance between the object plane and the top surface of prism 140 is about 1.41 inches. In some cases, such as Figure 1 , prisms 140 and 145 are mounted adjacent to each other and adjacent to lens 160. In this regard, prisms 140 and 145 are adjacent to a side of lens 160 that is farther from reflector 155. Prisms 140 and 145 each have a planar surface adjacent to the plane of lens 160. This plane of prisms 140 and 145 lies in a plane that is perpendicular to object plane 150, image plane 110, and the optical axes of lens assembly 150 and reflector 155.

[0056] The prism 140 has a top edge 142 extending toward the object plane 105 at an angle of 45° to the object plane 105 and at an angle of 45° to the plane of the lens 160. The prism 140 has a roof surface that is planar and extends to the top edge 142. The roof surfaces may be at a 90° angle to each other. The prism 145 has a plane that is parallel to and faces the object plane 105. The prism 145 has a surface 147 that is at a 45° angle to the object plane 105 and the image plane 110. The surface 147 is perpendicular to the plane containing the top edge 142 of the prism 140 and is perpendicular to the object plane 105 and the image plane 110. The surface 147 and the top edge 142 of the prism 140 converge relative to each other in a direction toward the reflector 155. The prisms 140 and 145 are generally adjacent to each other in a plane that is approximately halfway between the object plane 105 and the image plane 110 and is parallel to the object plane 105 and the image plane 110. In some cases, such as Figure 1 As shown in , prisms 140 and 145 have planar faces adjoining each other at this midpoint.

[0057] Prisms 140 and 145 and lenses 160, 165, 170, and 175 are appropriately sized (e.g., large enough) to receive and deliver a specific field size and shape to be projected from object plane 105 to image plane 110. Symmetrical magnification lens set 125 and asymmetric magnification lens set 130 may be used to provide a specific field size and shape. Figure 11 , a symmetrical magnifying lens group 125 is positioned between the object plane 105 and the prism 140, and an asymmetrical magnifying lens group 130 is positioned between the prism 145 and the image plane 110. The symmetrical magnifying lens group 125 can magnify the light beam 115 received from the object plane 105. The asymmetrical magnifying lens group 130 can magnify the light beam passing through the prism 145 to provide the light beam 120 to the image plane 110. In aspects in which the asymmetrical magnifying lens group 130 is not disposed in the optical system 100, the prism 145 can provide the light beam 120 to the image plane 110. For example, in an embodiment without the asymmetrical magnifying lens group 130, except that a surface of the prism 145 faces a surface of the light beam guiding lens 135 and the prism 145 provides the light beam 120 to the image plane 110 via the light beam guiding lens 135, Figure 1 The remaining components can remain as Figure 1 As shown in the general.

[0058] Symmetrical magnification lens group 125 provides symmetric magnification compensation along the x-direction and the y-direction. Symmetrical magnification lens group 125 includes lenses 125A to 125C. Lenses 125A to 125C may be or may collectively provide one or more spherical lenses. In one example, lenses 125A, 125B, and 125C may be plano-concave lenses, bi-convex lenses, and concave-planar lenses, respectively. In another example, lenses 125A, 125B, and 125C may be plano-convex lenses, bi-concave lenses, and convex-planar lenses, respectively. In one aspect, at least one of lenses 125A to 125C may be actuated by an actuator system ( Figure 1 125A-125C) to adjust the symmetrical magnification compensation provided by symmetrical magnification lens group 125. For example, the actuator system can be provided as part of optical system 100 or otherwise coupled to optical system 100. In some cases, one or two of lenses 125A-125C are movable, while the remaining lenses of lenses 125A-125C are expected to remain in a fixed position. In another embodiment, all lenses 125A-125C are movable.

[0059] Asymmetric magnifying lens group 130 provides magnification compensation adjustment along one or both of the x-direction or the y-direction. Asymmetric magnifying lens group 130 includes lenses 130A to 130C. Lenses 130A to 130C may be or may provide one or more cylindrical lenses together. In one example, lenses 130A, 130B and 130C may be plano-convex lenses, bi-concave lenses and convex-planar lenses. In another example, lenses 130A to 130C may be plano-concave lenses, bi-convex lenses and concave-planar lenses, respectively. The thickest portion of lenses 130A to 130C may be about 2 mm to about 10 mm. In one example, lenses 130A to 130C may be manufactured using round, square or rectangular glass. In some cases, a rectangular shape may be easier to produce and align. In one aspect, at least one of lenses 130A-130C can be moved (e.g., via translational motion) by an actuator system associated with optical system 100 to adjust the asymmetric magnification compensation provided by asymmetric magnification lens group 130. In some cases, one or two of lenses 130A-130C are movable, while the remaining lenses of lenses 130A-130C are expected to remain in a fixed position. In another embodiment, all lenses 130A-130C are movable.

[0060] In one aspect, the asymmetric magnification compensation range provided by the asymmetric magnification lens set 130 can be smaller (e.g., can be designed to be smaller) than the symmetric magnification compensation range provided by the symmetric magnification lens set 125, due to the effect of greater asymmetric magnification compensation on system astigmatism. As an example, the symmetric magnification lens set 125 can be used to provide a symmetric magnification compensation range of -250 parts per million (ppm) to +250 ppm in both the x-direction and the y-direction, while the asymmetric magnification lens set 130 can be used to provide a magnification compensation range of -50 ppm to +50 ppm in one or both of the x-direction or the y-direction. In one aspect, positive magnification compensation provides a magnification increase (e.g., relative to the case of no magnification compensation lens), negative magnification compensation provides a magnification decrease, and zero magnification compensation maintains magnification. In this example, the optical system 100 can provide a compensation range of approximately ±250 ppm symmetric compensation and a single-axis compensation range of approximately ±50 ppm.

[0061] In one aspect, the symmetrical magnifying lens group 125 can be or can be considered as two pairs of lenses. For example, the size of the gap (e.g., air gap) between the first pair of lenses can provide a magnification compensation range of 0 to +250 ppm, and the size of the gap between the second pair of lenses can provide a magnification compensation range of -250 ppm to 0. In this regard, the first pair of lenses can include lenses 125A and 125B, and the second pair of lenses can include lenses 125B and 125C.

[0062] Optionally, beam-directing lens 135 can receive the output of asymmetric magnifying lens group 130 and direct light beam 120 to image plane 110. In some cases, beam-directing lens 135 can have an adjustable tilt to direct light beam 120 in the x-direction and / or the y-direction (e.g., relative to a situation without beam-directing lens 135). In aspects where asymmetric magnifying lens group 130 is not disposed in optical system 100, prism 145 can provide light beam 120 to beam-directing lens 135 and beam-directing lens 135 can direct light beam 120 to image plane 110.

[0063] The optical path of the optical system 100 is the path of the light beam 115 provided from the object plane 105 through the optical system 100 to be directed onto the image plane 110 as the output light beam 120. It should be noted that when the light beam 115 passes through the optical path, passes through various components (e.g., lenses, mirrors) along the optical path, and / or impinges on a mirror surface, the intensity of the light beam 115 may be attenuated, such as due to absorption and / or scattering losses.

[0064] While passing through the optical path of the optical system 100, the light beam 115 passes through the object at the object plane 105 and enters the optical system 100. After entering the optical system 100, the light beam 115 passes through the symmetrical magnification lens group 125. The symmetrical magnification lens group 125 can apply symmetrical magnification compensation to the light beam 115. The resulting light beam leaves the symmetrical magnification lens group 125, passes through the prism 140, and is reflected by the prism 140 (such as the top edge 142) to different directions. The light beam reflected by the prism 140 passes through lenses 160, 165, 170, and 175 in sequence and hits different parts of the concave surface 180 of the reflector 155. The concave surface 180 of the reflector 155 reflects the incident light beam. The light beam reflected by the concave surface 180 passes through lenses 175, 170, 165, and 160 in sequence to the prism 145, after which the prism 145 directs the light beam to the asymmetrical magnification lens group 130. Asymmetric magnification lens set 130 can apply asymmetric magnification compensation to the light beam. The resulting light beam can be provided to beam steering lens 135 to be directed by beam steering lens 135 to image plane 110. The output of beam steering lens 135 is light beam 120, which can be considered as the output beam of optical system 100.

[0065] It should be noted that Figure 1Example combinations of prisms 140 and 145, lenses 160, 165, 170, and 175 of lens assembly 150, and mirror 155 and their arrangement (e.g., relative to object plane 105 and image plane 110) are shown. In some cases, fewer, more, and / or different components may be employed in optical system 100. For example, although symmetric magnification lens group 125 and asymmetric magnification lens group 130 are each depicted as having three lenses, symmetric magnification lens group 125 and asymmetric magnification lens group 130 may each have different Figure 1 , such as one lens, two lenses, or more than three lenses. Symmetrical magnification lens group 125 can have a different number of lenses than asymmetric magnification lens group 130. As another example, in some cases, beam steering lens 135 is not employed in optical system 100. As another example, one or more of lenses 160, 165, 170, and 175 of lens assembly 150 are not employed in optical system 100.

[0066] Other combinations of components and / or their configurations may be used in the optical system. As a variant, the positions of prisms 140 and 145 may be reversed without affecting the operation of prisms 140 and 145. As another variant, symmetrical magnifying lens group 125 and / or asymmetrical magnifying lens group 130 may be disposed at locations different from those of prisms 140 and 145. Figure 1 . For example, in one embodiment, the symmetrical magnifying lens group 125 can be placed between the prism 140 and the lens 160. In another example, the lens groups 125 and 130 can be placed between the lens 160 and either or both of the prisms 140 and 145. In another example, the lens groups 125 and 130 can be placed relative to Figure 1 140 and 145 and lens 160. In a variation of this example, asymmetric magnifying lens group 130 may be placed above prism 140 and symmetric magnifying lens group 125 may be placed below prism 145. In other words, asymmetric magnifying lens group 130 is located at an optical path point ahead of prism 140 and symmetric magnifying lens group 125 is located at an optical path point behind prism 145. In another configuration, lens groups 125 and 130 may be combined into a single lens group and placed in any of the previously defined positions. Various combinations of these examples and / or other arrangements may be utilized to place lens groups 125 and / or 130 relative to prisms 140 and 145 and lens 160. Additional examples of component combinations and / or arrangements thereof are provided in U.S. Pat. No. 5,559,629, which is incorporated herein by reference in its entirety.

[0067] although Figure 1The optical system 100 of FIG. 1 illustrates an example in which the object plane 105 is parallel to the image plane 110, but in another embodiment (not shown), the object plane 105 and the image plane 110 are not parallel to each other. In such an embodiment, the surface of the prism 140 closest to the object plane 105 is parallel to the object plane 105 and the surface of the prism 145 closest to the image plane 110 is parallel to the image plane 110. The planes of the prisms 140 and 145 closest to the lens 160 are parallel. For example, in such an embodiment, both the prisms 140 and 145 may be internally reflecting folding prisms.

[0068] Figure 2A and Figure 2B A diagram of a symmetrical magnifying lens group 125 and an asymmetrical magnifying lens group 130 of an optical system 100 and associated mounting systems and actuator systems are depicted in accordance with one or more embodiments of the present invention. However, not all depicted components are necessarily required, and one or more embodiments may include Figure 2A and Figure 2B Additional components not shown. Changes may be made to the arrangement and type of components without departing from the spirit or scope of the claims set forth herein. Additional, fewer and / or different components may be provided. For purposes of explanation, Figure 2A and Figure 2B Other components of the optical system 100, such as prisms 140 and 145 and lenses 160, 165, 170, and 175, are not shown. Figure 2A and Figure 2B As shown in FIG. 1 , the optical system 100 may include a housing 202 (eg, also referred to as an enclosure) in which a Figure 1 The various components and associated mounting systems and actuator systems shown in .

[0069] The mounting system may include structural features / components (e.g., screws, adhesives, clips, receiving interfaces, etc.) that help support (e.g., hold in place) lens groups 125 and 130 (and other possible components of optical system 100). The actuator system may include actuator 205, actuator 210, actuator controller 215, feedback device 220, and feedback device 225. Actuator 205 may be configured to move one or more lenses in symmetrical magnification lens group 125. For example, one, two, or all three lenses in symmetrical lens group 125 may be moved by actuator 205, while the remaining lenses in symmetrical lens group 125 (if present) remain fixed in position. Similarly, actuator 210 may be configured to move one or more lenses in asymmetrical lens group 130. Actuator controller 215 may receive information and generate control signals for actuators 205 and 210 based on the received information. Feedback devices 220 and 225 may each be, may each include, or may each be part of an encoder, a capacitive, inductive or laser sensor, a strain gauge, and / or substantially any device that can be used to verify the respective positions of lenses 125A-125C and 130A-130C before, during, and after movement. In this regard, actuator controller 215 and feedback devices 220 and 225 may operate in conjunction (e.g., exchange appropriate information) to help ensure that lenses 125A-125C and 130A-130C are in proper positions before, during, and after moving one or more of lenses 125A-125C and one or more of lenses 130A-130C.

[0070] In one embodiment, the actuator controller 215 may receive information associated with the relative positioning of the mask and the wafer. In a lithography system, images of the mask and the wafer may be captured by a camera system to determine an expected projection of the mask (e.g., a pattern of the mask) onto the wafer. The expected projection may be used to determine the magnification compensation and / or beam steering required to adjust from the expected projection to the desired projection. For example, if the image of the wafer target taken at one or more locations on the wafer is farther away from the center of the wafer than the mask target, then the wafer is determined to have positive magnification and positive magnification and steering may be appropriately applied. If the image of the wafer target is closer to the center of the wafer than the mask target, then the wafer is determined to have negative magnification and negative magnification and steering may be appropriately applied. It should be noted that the above examples are limited to situations where the mask does not have a magnification deviation. If the mask has a magnification deviation, then appropriate calculations may be applied to provide the desired magnification. In general, it is desired that the printed mask image matches the magnification of the wafer image (referred to as zero magnification) so that the new printed features are appropriately overlaid onto the previously printed features of all components of the wafer. In this regard, the various embodiments may be used to print zero magnification, positive magnification, or negative magnification as desired. Additionally, beam steering may be used to correct for positional offsets of the wafer target relative to the mask target.

[0071] In some aspects, multiple points are detected on the wafer relative to the mask to determine proper alignment. In some cases, for symmetric magnification compensation, a minimum of two points are required to determine whether symmetric magnification compensation should be utilized, and for asymmetric magnification compensation, at least three points and preferably four points are required to determine whether asymmetric magnification compensation should be utilized. However, more points on the wafer may be detected to give an overall better alignment and magnification performance.

[0072] Additional use of beam steering or micro-wafer positioning can be used to compensate for small translational and / or rotational differences between the mask and the wafer that are identified during the alignment routine. For example, if the wafer is translated relative to the mask, the wafer can be repositioned to be directly under the mask or beam steering can be used to compensate for the offset. This repositioning and / or beam steering can also be applied to rotational differences. It can also be applied in situations where the alignment requires different corrections in the x-direction and the y-direction.

[0073] In some cases, the control signal may indicate magnification compensation provided by lens groups 125 and / or 130. In these cases, actuators 205 and 210 may determine (e.g., using a processor) the distance to move one or more movable lenses to achieve the magnification compensation indicated in the control signal and move one or more appropriate lenses the determined distance. In other cases, alternatively and / or in combination, the control signal may directly indicate a distance to actuators 205 and / or 210 to move one or more movable lenses in their respective lens groups.

[0074] As previously discussed, changes in the magnification of the image projected onto image plane 110 may be achieved by adjusting one or both of symmetric magnification lens group 125 and asymmetric magnification lens group 130 . FIG. 3A to FIG. 3C An example of the relative positioning of lenses 125A-125C in the symmetrical magnifying lens set 125 is shown in accordance with one or more embodiments of the present invention. FIG. 3A to FIG. 3C In the embodiment, lenses 125A to 125B remain in fixed position, while lens 125C is movable along the propagation direction of light 305 (eg, z direction).

[0075] FIG. 3A to FIG. 3C Dashed line 310 in pictorial diagram depicts the optical path of the portion of light 305 that passes through the optical axis of symmetric magnifying lens group 125. Lenses 125A-125C in symmetric magnifying lens group 125 are positioned so that their respective optical axes overlap. The portion of 305 that passes through the optical axis of symmetric magnifying lens group 125 is not refracted (e.g., bent) by lenses 125A-125C. FIG. 3A to FIG. 3C The dashed line 315 in FIG. 3 is parallel to the optical axis and is displaced from the optical axis by a distance r along the x-axis. Figure 3A , Figure 3B and Figure 3CSolid lines 320 , 325 , and 330 in FIG. 3 are optical paths of a portion of light 305 entering lens 125A from the z direction at a distance r from line 310 , respectively.

[0076] To adjust the magnification compensation provided by symmetrical magnifying lens set 125, the distance between the uppermost surface of lens 125A and the lowermost surface of lens 125C is adjusted by moving lens 125C in the z direction (e.g., by an actuator) and keeping lenses 125A and 125B in a fixed position ( Figure 3A , Figure 3B and Figure 3C In the A , D B and D C ). For example, in FIG. 3A to FIG. 3C Middle, D A <D B <D C In other cases, alternatively and / or additionally, lenses 125A and / or 125B may be movable to adjust the distance between the uppermost surface of lens 125A and the lowermost surface of lens 125C. In some cases, a smaller number of movable lenses may be associated with a reduced number of actuators and / or complexity.

[0077] exist FIG. 3A to FIG. 3C Since only lens 125C is movable in this example, the different distances D A , D B and D C Due to the different gap sizes (e.g., air gap sizes) between lenses 125B and 125C. With respect to a light beam having an optical path away from the optical axis (which is represented by line 310), lenses 125A and 125B refract the light beam. Due to the different gaps between lenses 125B and 125C to be passed by the light beam, the optical paths of the light beam (shown by solid lines 320, 325, and 330) deviate from each other relative to line 315 during the portion of the optical path after exiting lens 125B. Figure 3A In FIG. 1 , the light beam leaves lens 125B and converges toward line 315, but does not reach line 315. At the output of lens 125C, a distance between line 310 and line 320 is given by r. A In this regard, the gap between lenses 125B and 125C causes r <r A , which indicates that the symmetrical magnifying lens group 125 increases the magnification. The increase in magnification can be referred to as positive magnification compensation.

[0078] exist Figure 3B In FIG. 1 , the light beam leaves lens 125B and converges toward line 315, overlapping line 315. At the output of lens 125C, the distance between line 310 and line 325 is given by r BIn this regard, the gap between lenses 125B and 125C results in r=r B , which indicates that the symmetrical magnifying lens group 125 provides no magnification (e.g., provides zero magnification compensation). Figure 3C In FIG. 1 , the light beam leaves lens 125C and converges toward line 315 and then passes through line 315. At the output of lens 125C, the distance between line 310 and line 330 is given by r c In this regard, the gap between lenses 125B and 125C results in r>r C , which indicates that the symmetrical magnification lens group 125 reduces the magnification. The magnification reduction can be quantified by the negative magnification compensation.

[0079] although FIG. 3A to FIG. 3C The description of 125A to 125C in symmetrical magnifying lens group 125 is with reference to lenses 125A to 125C in symmetrical magnifying lens group 125 , but a similar description is generally applicable to lenses 130A to 130C in asymmetrical magnifying lens group 130 .

[0080] Figure 4A Example cross-sectional views of lenses 125A- 125C are shown in accordance with one or more embodiments of the present invention. Figure 4B Example cross-sectional views of lenses 130A- 130C are shown in accordance with one or more embodiments of the present invention.

[0081] In one embodiment, the magnifying lens group (e.g., 125, 130) can be designed so that the magnifying lens group can selectively add a controllable amount of magnification to the optical system (e.g., 100) to change the magnification associated with the optical system, as is known to those of ordinary skill in the art. For example, for a thin lens group of two lenses, the combination of the thin lens magnifications (expressed as ) can be calculated as follows:

[0082]

[0083] in is the first lens magnification, is the second lens magnification, and d is the distance between the first lens and the second lens. but Therefore, in this case, when the lens gap (eg, lens air gap) is zero (ie, d=0), the thin magnifying lens group has zero magnification. When the lens gap increases, the magnification of the magnifying lens group increases.

[0084] Since d is a positive value, this magnifying lens group produces positive magnification. In one aspect, to produce positive or negative magnification correction for the magnifying lens, another thin lens group with opposite (e.g., and equal) lens magnification can be employed, so the magnifying lens group magnification of the two lens groups is as follows:

[0085]

[0086] where d 1 is the distance between the two lenses in the first thin lens group and d 2 is the distance between the two lenses in the second thin lens group. 1 =d 2 hour, When 1 >d 2 hour, When 1 <d 2 hour, In this case, the magnifying lens group has four thin lenses. If the middle two lenses are combined into a biconvex or biconcave lens, the four thin lenses can be three lenses. In one embodiment, the magnifying lens group 125 and / or 130 can include the first thin lens group and the second thin lens group provided above. For example, in the case of the magnifying lens group 130, the distance d 1 may represent the gap between lenses 130A and 130B, and the distance d 2 may represent the gap between lenses 130B and 130C.

[0087] In the above, In other cases, (e.g., the magnitude of the first lens power is not equal to the second lens power.) In these cases, when hour, when hour, when hour,

[0088] In some cases, a magnification lens group with more lenses may allow for a larger magnification correction range (e.g., also referred to as a magnification compensation range). In this regard, when a larger magnification correction range is desired (e.g., a magnification correction range of about or greater than ±250 ppm), three, four, or more lenses may be used in the magnification lens group. For example, magnification lens group 125 includes lenses 125A-125C and may provide a magnification correction range of about ±250 ppm in some cases. In some cases, two lenses in the magnification lens group may be selected when the magnification correction is generally within a relatively small range (e.g., a magnification correction range of about or less than 70 ppm (e.g., between -70 ppm to +70 ppm, between -70 ppm to 0, between 0 to +70 ppm, etc.). For example, additional lenses in a four-lens group (e.g., relative to a two-lens group) may introduce additional distortion into the optical system. Thus, fewer lenses may be used within a smaller desired magnification correction range to reduce distortion.

[0089] In one embodiment, the optical system 100 (and / or other optical systems) can be used in a stepper lithography tool or a scanner lithography tool. For example, the optical system 100 can be used in a Dyson lens system used in a stepper or scanner. In one aspect, when used in a stepper, a full field is exposed at a time. In a stepper, the field generally has a rectangular shape. The symmetric magnification lens group 125 and the asymmetric magnification lens group 130 can be used to adjust the magnification of the field (e.g., applying magnification compensation to the field). As the field steps to the next site, the step size changes to achieve magnification across the wafer. In a stepper tool, the field of view (FOV) is smaller than the wafer, so the stepper tool makes the FOV span the wafer. Each step is considered as a point. In some cases, when this magnification adjustment is used in a stepper tool, the magnification can be set according to the average magnification across the entire wafer. In other cases, when this magnification adjustment is used in a stepper tool, the magnification setting can be adjusted to the average magnification of the field being exposed, and the magnification setting can be adjusted as the wafer moves from one site to another.

[0090] Asymmetric magnification lens set 130 may be used to achieve asymmetric magnification. Asymmetric magnification lens set 130 may be oriented to provide magnification compensation along an axis of the FOV of the scanner (e.g., magnification compensation along the x-direction or the y-direction). In one embodiment, asymmetric magnification lens set 130 is oriented to produce asymmetric magnification normal to the scanning direction. For example, the scanning direction may be the x-direction, and magnification compensation may be applied in the y-direction.

[0091] In operation, the symmetric magnification lens set 125 can provide symmetric magnification compensation in both the x-direction and the y-direction across the FOV of the scanner, while the asymmetric magnification lens set 130 can provide magnification compensation in the y-direction. An example range for symmetric magnification compensation can be about ±250 ppm, and an example range for asymmetric magnification compensation can be about ±50 ppm (e.g., in the y-direction). In this regard, any symmetric magnification compensation between +250 ppm and -250 ppm can be achieved, and any asymmetric magnification compensation between +50 ppm and -50 ppm can be achieved. These example ranges provide the following extremes, where X and Y are the nominal x-direction magnification and nominal y-direction magnification of the optical system 100 (e.g., including zero magnification compensation in the x-direction and the y-direction):

[0092] Extreme value 1: Maximum symmetrical magnification compensation + maximum asymmetrical magnification compensation

[0093] X+250ppm, Y+300ppm

[0094] Extreme value 2: Maximum symmetrical magnification compensation + minimum asymmetrical magnification compensation

[0095] X+250ppm, Y+200ppm

[0096] Extreme value 3: minimum symmetrical magnification compensation + maximum asymmetrical magnification compensation

[0097] X-250ppm, Y-200ppm

[0098] Extreme value 4: minimum symmetrical magnification compensation + minimum asymmetrical magnification compensation

[0099] X-250ppm, Y-300ppm

[0100] In some cases, the amount of symmetric magnification and / or asymmetric magnification can be adjusted with minor modifications to the optical and mechanical design without changing the primary design of the optical system. For example, the amount of symmetric and asymmetric magnification can be increased or decreased with minor modifications to the optical and mechanical design without changing the primary design. These minor modifications can include adjusting the radius of the magnification compensation lens and increasing or decreasing the stroke of the lens. In some cases, an order of magnitude of about two to about three times the design magnification can be achieved.

[0101] although Figure 1 4 are described with reference to two lens groups each having three lenses, but each lens group may have less than, more than and / or different from Figure 1 to the lens shown in FIG4. In addition, although Figure 1 4 provide example embodiments in which one set of lenses may be configured (e.g., designed) to provide symmetric magnification and another set of lenses may be configured to provide asymmetric magnification, although more and / or different lens sets may be utilized in other embodiments to provide symmetric and / or asymmetric magnification. As an example, in another embodiment, the optical system may include two asymmetric cylindrical lens assemblies. In some cases, such an optical system would ideally align two lens sets that are orthogonal to each other, with one set of lenses along X for ±250 ppm magnification along the x-direction and a second set of lenses along Y for ±250 ppm magnification along the y-direction.

[0102] Figure 5 A lens binary 500 of an optical system according to one or more embodiments of the present invention is shown. Lens binary 500 includes lens 505 and lens 510. Lenses 505 and 510 may be aligned such that lenses 505 and 510 share an optical axis. Lenses 505 and 510 are spaced a distance d along the z-axis (e.g., separated by air). Figure 5 In the embodiment, the lens binary 500 forms a symmetrical magnifying lens group to provide rotationally symmetrical magnification compensation. For example, lenses 505 and 510 can be a plano-convex lens and a plano-concave lens, respectively. In one embodiment, the lens binary 500 can be used as Figure 1The symmetrical magnifying lens group 125 shown in FIG.

[0103] Dashed line 515 depicts the optical path of a beam of light that passes through the optical axis of lens binary 500 (e.g., the optical axes of lenses 505 and 510). Dashed line 520 is parallel to the optical axis and displaced from the optical axis by a distance r in the x-direction. Solid line 525 depicts the optical path of a beam of light that enters through lens 505 at a distance r from line 515, converges toward line 515 when passing through the air gap between lenses 505 and 510, and passes through lens 510 at a distance r1=r-(Δx / Δy) from the optical axis. Since r>r1, lens binary 500 reduces magnification (e.g., provides negative magnification compensation). To adjust the magnification compensation provided by lens binary 500, one or both of lenses 505 or lenses 510 may be moved. For example, lenses 505 and / or 510 may be moved in the z-direction by one or more actuators of an actuator system to adjust the distance d between lenses 505 and 510.

[0104] In one aspect, Figure 5 The lens binary 500 generates negative or positive magnification compensation by only one gap. This magnification compensation can be as previously described for That is, in this case, when hour, when hour, when hour, When lenses 505 and 510 have different radii, the magnification of the two lens groups (expressed as ) can change from positive to negative due to the change in the value of the gap d between lenses 505 and 510. In some cases, using a lens dyad can be cheaper and / or result in a simpler product than using a lens triplet or more than three lenses.

[0105] although Figure 5The lens dyad 500 of symmetrical magnification lens group is formed, but the optical system may employ the lens dyad for asymmetrical magnification lens group instead of lens dyad 500 and / or in addition to lens dyad 500. In this regard, the number of lenses in the symmetrical magnification lens group may be the same as or different from the number of lenses in the asymmetrical magnification lens group. The number of lenses used in the optical system may be based on considerations such as cost, manufacturing complexity, performance specifications, and / or other considerations. In some cases, the lens dyad may be associated with lower monetary cost and manufacturing complexity (e.g., compared to a lens group having three or more lenses). In some cases, when the symmetrical magnification lens group and the asymmetrical magnification lens group each include a lens dyad, the mask may be asymmetrically undersized and / or oversized. For example, relative to a reference size mask, the mask may have different portions of the mask undersized and / or oversized by different factors.

[0106] In one embodiment, an asymmetric magnifying lens set can be used to provide asymmetric magnification compensation and only one of positive or negative magnification compensation along only one direction (e.g., the x-direction or the y-direction). For example, instead of having one of the axes corrected to any value between -50 ppm and +50 ppm for an asymmetric magnifying lens set having three (or more) lenses, an asymmetric magnifying lens set having two lenses can be used to have one of the axes corrected to any value between 0 and +50 ppm or 0 and -50 ppm. In some cases, using two lenses can be easier to manufacture (e.g., each lens of the two-lens system can be made thicker). In some cases, the lens binary can be rotated to allow for magnification compensation along one axis. For example, in one orientation of the lens binary, the lens binary can provide asymmetric magnification correction along only the x-axis. This lens binary can be rotated 90° to provide magnification correction along only the y-axis.

[0107] In some embodiments, lenses 130A, 130B, and 130C in asymmetric magnifying lens group 130 may be plano-convex cylindrical lenses, bi-concave cylindrical lenses, and convex-plano lenses, wherein the thickest portion of lenses 130A to 130C is about 2 mm to about 10 mm. In one aspect, a single lens may be used to replace lenses 130A, 130B, and 130C. Figure 6 An asymmetric magnifying lens 600 according to one or more embodiments of the present invention is shown. In one embodiment, the asymmetric magnifying lens set 130 may be the asymmetric magnifying lens 600. In other embodiments, the asymmetric magnifying lens set 130 may include the asymmetric magnifying lens 600 and one or more other lenses.

[0108] The asymmetric magnifying lens 600 may be a flat window such as Figure 6. The actuator can bend the asymmetric magnifying lens 600 to cause the planar window to deform into a meniscus lens that can produce magnification compensation (e.g., along its bending axis). Depending on the direction in which the asymmetric magnifying lens 600 is bent, the asymmetric magnifying lens 600 can produce positive or negative magnification compensation. In some cases, the asymmetric magnifying lens 600 can be selectively bent (e.g., deformed) in the x-direction, the y-direction, or both as needed to produce a desired magnification compensation (e.g., asymmetric magnification compensation) in one or both of the x-direction or the y-direction.

[0109] In one aspect, an actuator system may be provided to control the magnification provided by the asymmetric magnifying lens 600. The actuator system may include an actuator 620, an actuator controller 625, and a feedback device 630. The actuator 620 may be configured to apply a force on the asymmetric magnifying lens 600 in a set direction to provide magnification compensation in the x-direction, the y-direction, or both, according to a control signal provided to the actuator 620 by the actuator controller 625. The actuator controller 625 may receive information and generate these control signals for the actuator 620 based on the received information. The information may indicate the desired magnification provided by the asymmetric magnifying lens 600. In some cases, the control signal generated by the actuator controller 625 may indicate the force (if any) applied by the actuator 620 on the asymmetric magnifying lens 600 and the direction of the applied force. As a result of applying the force on the asymmetric magnifying lens 600, the actuator 620 may cause the asymmetric magnifying lens 600 to provide the desired magnification. Feedback device 630 may be, include, or be part of an encoder, a capacitive, inductive or laser sensor, a strain gauge, and / or substantially any device that can be used to verify the configuration (e.g., amount of bend, direction of bend, associated magnification) of asymmetric magnifying lens 600 before, during, and / or after force is applied by actuator 620. In this regard, actuator controller 625 and feedback device 630 may operate in coordination (e.g., exchange appropriate information) to help ensure that asymmetric magnifying lens 600 is properly configured. In some cases, actuator 620 or other actuators may rotate asymmetric magnifying lens 600 instead of or in addition to bending asymmetric magnifying lens 600 to achieve desired magnification compensation along the x-direction, y-direction, or both.

[0110] For example, the asymmetric magnifying lens 600 can be bent by the actuator 620 (e.g., based on an appropriate control signal from the actuator controller 625) to provide a lens 605 that causes positive magnification compensation when the light 615 travels in a direction opposite to the bending direction. As another example, the asymmetric lens 600 can be bent by the actuator 620 to provide a lens 610 that causes negative magnification compensation when the light 615 travels in a direction that is the same as the bending direction. When the asymmetric magnifying lens 600 is not bent, the asymmetric magnifying lens 600 does not provide magnification compensation. In one aspect, using a single lens (such as the asymmetric magnifying lens 600) can involve mechanical design and / or control complexity (e.g., associated with bending) and can allow for easier manufacturing, smaller optical thickness, and occupying less space in the optical system. In some cases, alternatively and / or additionally, a single symmetric magnifying lens that can be deformed to provide symmetric positive magnification compensation or symmetric negative magnification compensation can be used as a symmetric magnifying lens set.

[0111] Figure 7 A beam directing lens 135 of the optical system 100 is shown in accordance with one or more embodiments of the present invention. The beam directing lens 135 may also be referred to as a tilting lens. The beam directing lens 135 may be appropriately tilted (e.g., by an actuator of an actuator system) to redirect the beam to a desired location (e.g., on the image plane 110). For example, the beam directing lens 135 may be coupled to an actuator system that may control the tilt of the beam directing lens 135. The actuator system may include an actuator 705, an actuator controller 710, and a feedback device 715, which may be implemented in the same or similar manner as described above. Figure 2A , Figure 2B and Figure 6 The tilt can be represented by one or more angles. An angle α can provide the amount of tilt along the x-direction. Another angle (not shown) can provide the amount of tilt along the y-direction. Figure 7 In FIG. 1 , the tilt of the beam guiding lens 135 causes the light beam to be displaced by a distance (Δx / Δy) relative to the case where the beam guiding lens 135 is not tilted. Figure 7 As shown in , the displacement of the light beam due to the beam guiding lens 135 is based on one or more tilt angles of the beam guiding lens 135 and the size of the beam guiding lens 135 (eg, the distance within the beam guiding lens 135 that the light beam needs to propagate through).

[0112] Figure 8 A beam directing lens 800 and associated components are shown in accordance with one or more embodiments of the present invention. However, not all depicted components are necessarily required, and one or more embodiments may include Figure 8Additional components not shown in the drawings. The arrangement and types of components may be changed without departing from the spirit or scope of the claims set forth herein. Additional, fewer and / or different components may be provided. In one embodiment, the optical system 100 may be used to provide optical asymmetric magnification and beam steering. In one embodiment, the beam steering lens 800 may be the beam steering lens 135.

[0113] The beam steering lens 800 may be supported in annular housings 805 and 825. The annular housing 805 has a pivot 810 that allows the beam steering lens 800 to rotate in a first direction (e.g., the x-direction). A flexure 812 is connected to the annular housing 805. A linear drive 815 includes a voice coil actuator 820, a ball guide assembly (not shown), and a linear encoder. The voice coil actuator 820 may be coupled to the flexure 812 and may displace the flexure 812 through a linear axis to cause the beam steering lens 800 to rotate. The linear encoder of the linear drive 815 may provide feedback to the voice coil actuator 820 and / or the ball guide assembly to control the displacement and / or rotation of the beam steering lens 800 achieved by the linear drive 815.

[0114] Annular housing 825 of beam steering lens 800 may facilitate tilting of beam steering lens 800 along a second axis. For example, the second axis may be orthogonal to the first axis. Annular housing 825 is coupled to annular housing 805. Annular housing 825 has a pivot 830. Pivot 830 is attached to flexure member 835 and linear drive 840. Linear drive 840 includes voice coil actuator 845, ball guide assembly (not shown), and linear encoder 850. Voice coil actuator 845 may be coupled to flexure member 835 and may displace flexure member 835 through a linear axis to cause beam steering lens 800 to rotate. Linear encoder 850 may provide feedback to voice coil actuator 845 and / or ball guide assembly of linear drive 840 to control displacement and / or rotation of beam steering lens 800 achieved by linear drive 840.

[0115] although Figure 8 An example of a beam steering lens and associated components (e.g., for mechanically displacing and / or rotating the beam steering lens) is depicted, but other beam steering lenses and / or associated components may be employed. For example, voice coil actuators 820 and / or 845 may be replaced with mechanical or pneumatic linear actuators and / or piezoelectric stepper actuators or voice coil actuators 820 and / or 845 and mechanical or pneumatic linear actuators and / or piezoelectric stepper actuators may be used. As another example, the ball guide assembly may be a crossed roller guide. In some aspects, a cam attached to a rotary motor may be used to tilt the beam steering lens. In some aspects, a rotary motor and / or a gear motor may be used to directly drive the axis of the beam steering lens.

[0116] In some embodiments, the beam directing lens (e.g., 135, 700, 800) may be combined with one or more lens groups described herein (e.g., Figures 1 to 6 In some aspects, the beam steering lens can be used with one or more lens groups such as one or more symmetrical magnifying lens groups (e.g., 125) and / or one or more asymmetrical magnifying lens groups (e.g., 130). For example, referring to Figure 1 , the beam directing lens 135 can be used with the symmetrical magnifying lens group 125 (e.g., without the asymmetrical magnifying lens group 130), or the beam directing lens 135 can be used with the asymmetrical magnifying lens group 130 (e.g., without the symmetrical magnifying lens group 125).

[0117] Removing one of the magnifying lens groups 125 or 130 Figure 1 Such modification of optical system 100 may be associated with appropriate adjustment (e.g., positioning) of one or more associated components, such as prisms 140 and 145 and lenses 160, 165, 170, and 175, or no adjustment of any of these components. As an example, consider removing asymmetric magnifying lens group 130 from optical system 100. In one case, symmetric magnifying lens group 125, prisms 140 and 145, lenses 160, 165, 170, and 175, and mirror 155 may remain as described previously. Figure 1 The output beam from prism 145 may be provided to beam directing lens 135 (eg, as beam 120) and directed onto image plane 110. In another case, symmetrical magnifying lens set 125 may be positioned at Figure 1 , while the prisms 140 and 145, the lenses 160, 165, 170 and 175 and the reflector 155 can be kept as shown in FIG. Figure 1 The output beam from the symmetrical magnifying lens set 125 may be provided to the beam steering lens 135 and directed onto the image plane 110. In yet another case, the symmetrical magnifying lens set 125 may be positioned at other locations, such as between the prisms 140 and 145. Other means may be utilized to provide the symmetrical magnifying lens set 125 and not provide the asymmetrical magnifying lens set 130.

[0118] In one or more embodiments, the optical system may be, may include, or may be a part of a projection lens system for use in a lithography system. Fig. 9 A lithography system 900 is shown in accordance with one or more embodiments of the present invention. However, not all depiction components are required, and one or more embodiments may include Fig. 9Additional components not shown in the drawings. The arrangement and types of components may be changed without departing from the spirit or scope of the claims set forth herein. Additional, fewer and / or different components may be provided. In one embodiment, the optical system 100 may be used to provide optical asymmetric magnification and beam steering.

[0119] The photolithography system 900 includes a radiation source 905, mirrors 910 and 915, a mask 925, an optical system 930, a wafer 935, and an air flotation platform 940. Fig. 9 925 , mirrors 910 and 915 are used to direct radiation (e.g., UV light) from radiation source 905 to optical components of mask 925. Fewer, more, and / or different optical components may be provided between radiation source 905 and mask 925. For example, additional optical components such as optical waveguides, lenses, and mirrors may be located between mirrors 910 and 915. In some cases, mirrors 910 and 915 and / or other optical components may adjust beam characteristics of radiation from radiation source 905, such as optical path length (e.g., distance traveled by radiation from radiation source 905 to reach mask 925), beam shape, beam size, beam polarization, and the like. Mask 925 may be disposed at an object plane of lithography system 900, and wafer 935 may be disposed at image plane 110 of lithography system 900, wherein lithography system 900 is used to project a pattern on mask 925 onto wafer 935 using optical system 930. In this regard, the optical system 930 can provide symmetric and / or asymmetric magnification. In one embodiment, the optical system 930 can be Figure 1 The optical system 100 may include Figure 1 The optical system 100 may be Figure 1 In this embodiment, the mask 925 is disposed at the object plane 105 and the wafer 935 is disposed at the image plane 110.

[0120] In some embodiments, the lithography system 900 may be a scanning lithography machine, may include a scanning lithography machine, or may be a part of a scanning lithography machine. Fig.10 A scanning lithography machine or portion thereof is depicted in accordance with one or more embodiments of the present invention. In this embodiment, both wafer 935 and mask 925 may be mounted to a carriage that is scanned by optical system 930 at a translation stage. Wafer 935 and mask 925 may be aligned with each other prior to the scanning process. The alignment process may involve translating and / or rotating wafer 935 relative to mask 925 and may be performed using a wafer positioning stage.

[0121] Fig.11A and Fig. 11BAn example of an exposure field of a scanning lithography machine is shown. The exposure field represents the FOV of the scanner of the lithography system 900. The exposure field moves across the wafer 935 in the x-direction and is displaced in the y-direction, and reverses the x-direction after reaching a turning point, as shown in FIG. Fig.11A and Fig. 11B In some cases, temporally adjacent scans may overlap to help produce uniform exposure across the wafer 935. Fig.11A In , the exposure field (e.g., 1105) has a diamond shape. Fig. 11B In the embodiment of the present invention, the exposure field has a hexagonal shape. In some cases, using a hexagonal exposure field can reduce the time required to scan the wafer 935 due to an increased step size between scans. In this regard, the hexagonal shape allows for a reduced overlap area, which allows for a reduced number of scans, higher machine productivity. Although the following description is provided with respect to a diamond-shaped exposure field, other exposure field shapes such as hexagonal, rectangular, etc. can be utilized.

[0122] In some embodiments, it is desirable to adjust the size of the exposure field (eg, diamond, hexagon, etc.) during scanning across the wafer 935 and / or it is desirable to manipulate the location on the wafer 935 where the exposure field is illuminated. Fig.12 The actual and desired die sizes and locations of various dies on the wafer 935 are shown. Fig.12 935, the same magnification is associated with each portion of wafer 935 and the same (or no) beam guide is associated with wafer 935. The actual grain size and location overlaps with the desired grain size and location. Die 1205 (e.g., the center die of wafer 935) is the actual grain size and location, while die 1210 is the corresponding desired grain size and location for die 1205. Similarly, die 1215 is the actual grain size and location, while die 1220 is the corresponding desired grain size and location for die 1215.

[0123] Fig.13A supply Fig.12 FIG. 1 is a magnified view of die 1205 and die 1210. To obtain die 1210, die 1205 may remain at the same location, but positive magnification compensation may be applied to provide a larger projection on wafer 935. Fig. 13B supply Fig.12 1215 and 1220. To obtain the grain 1220, positive magnification compensation and image shifting can be applied. Figure 1 , positive power compensation can be provided by the symmetric lens group 125 and / or the asymmetric lens group 130, and the shift can be applied by the beam steering lens 135.

[0124] In some cases, this magnification compensation and / or image steering can be adjusted as the wafer 935 is translated back and forth in the exposure field. As previously indicated, one or more beam steering lenses can be utilized to manipulate the position of the image formed at the image plane (e.g., formed at the wafer 935). This technique may be referred to as beam steering. For photolithography applications, beam steering can be used to coordinate the projected image of the tilted mask 925 using the beam steering lenses and the wafer position. FIG. 14A to FIG. 14C FIG. 9 is an illustration of the tilting of the beam directing lens of the optical system 900 when the wafer 935 is moved according to one or more embodiments of the present invention. Fig.12 and FIG. 14A to FIG. 14C , when scanning the wafer 935 from left to right, the beam can be tilted to project the image further toward the left extreme of the wafer 935. Fig.14A As wafer 935 is scanned rightward from position 925 in FIG. 1 , the tilt provided by the beam steering lens may be continuously adjusted in synchronization with the motion of wafer 935 and mask 925 (which are locked together in a scanner system, for example). Fig. 14B As shown in , the beam steering lens can provide zero tilt when the wafer 935 is directly below the beam steering lens (e.g., at the center die). Fig. 14C As shown in FIG. 9A , as the wafer 935 continues to the right, the beam steering lens is tilted to project the image to the right extreme of the wafer 935. Return to Reference Figure 7 The beam steering lens may allow for tilting along one or both of the x-axis and the y-axis. For example, if scanning occurs along the x-direction, then x-axis tilting of the beam steering lens is performed synchronously with the wafer scanning motion along the x-direction. The y-axis tilting may be performed during stepping between scan rows.

[0125] In some embodiments, microchip positioning may be utilized in lieu of and / or in addition to beam steering using one or more beam steering lenses. In microchip positioning, the position of the wafer relative to the mask may be finely adjusted as the wafer 935 is scanned across an optical system (e.g., with or without beam steering lenses). While the wafer positioning stage maintains the relative positioning of the mask 925 and the wafer 935 during scanning exposures, the position of the wafer 935 may be driven along the scan axis as the translation stage performs its scan path. Microchip positioning may cause the wafer 935 to shift relative to the mask 925 in a coordinated manner with the translation stage as the wafer 935 is scanned in the +x direction (e.g., to the right). In this manner, the wafer 935 is continuously moved relative to the mask 925 during a scan column. When the translation stage steps to the next column, the translation stage may perform microstepping to shift the wafer 935 relative to the mask 925 to adjust for offsets in the y direction. In some cases, micro-wafer positioning may be performed by a wafer positioning controller, which may adjust the position of the wafer relative to the position of the mask to shift the position on the wafer 935 where the image is formed on the wafer 935 as a result of moving the wafer 935. It should be noted that although the above description of the present invention refers to the x-axis and the y-axis as the scanning axis and the stepping axis, respectively, it should be understood that the x-axis may also be referred to as the stepping axis and the y-axis as the scanning axis.

[0126] Return to reference Fig.10 The wafer positioning stage may have accurate and very fine positioning actuators that can be used to achieve the micro wafer positioning described above. In some cases, mechanical piezoelectric actuators with strain gauge feedback acting on a mechanical flexure system can be used to adjust the position of the wafer relative to the mask while the translation stage is in motion to scan and step the wafer under the lens FOV.

[0127] For example, FIG. 15A to FIG. 15D The position of the scanner exposure FOV and the associated wafer position shift are shown in accordance with one or more embodiments of the present invention. Fig.15A The microchip positioning at the start of a scan is shown, with the chip 935 shifted in the -x direction (eg, left) and the -y direction (eg, downward). Fig. 15B The microchip positioning at the end of the scan is shown, with the chip 935 shifted in the +x direction (eg, to the right). Fig. 15C The microchip positioning at the beginning of a scan is shown, with the chip 935 shifted in the -x direction and the +y direction. Fig.15D The microchip positioning at the end of the scan is shown, with the chip 935 displaced in the +x direction.

[0128] In one embodiment, an actuator controller (e.g., 215 in FIG. 2 ) may receive information associated with the relative positioning of the mask 925 and the wafer 935. In a lithography system, images of the mask 925 and the wafer 935 may be captured by a camera system to determine an expected projection of the mask 925 (e.g., a pattern of the mask 925) onto the wafer 935. The expected projection may be used to determine the magnification compensation, beam steering, and / or microchip positioning required to adjust from the expected projection to the desired projection. The actuator controller may generate control signals associated with magnification compensation, beam steering, and / or microchip positioning and provide these control signals to relevant components to achieve magnification compensation (e.g., actuators 205 and 210 of lens groups 125 and 130), beam steering (e.g., actuators of beam steering lens 135), and / or microchip positioning. FIG. 14A to FIG. 14C and FIG. 15A to FIG. 15D Describes the implementation of magnification compensation, beam steering and / or microchip positioning.

[0129] In one embodiment, for example, the wafer 935 may be moved (e.g., using an actuator system) at a constant speed relative to the mask 925 in an alternating manner for each scan. Figure 2A and Fig. 9 , to achieve a target magnification of 200 ppm, actuator 205 may move symmetrical magnifying lens set 125 to a position associated with providing a magnification of 200 ppm, and wafer 935 will then scan an amount equal to 200 ppm across wafer 935 relative to mask 925 on each pass. For smaller magnification amounts, the shift may generally be smaller. The associated speed may be defined by the amount of shift (e.g., based on the magnification amount) divided by the time to complete the pass. In this regard, a smaller target magnification (e.g., 50 ppm) may utilize a smaller shift and therefore a smaller speed relative to a larger target magnification (e.g., 200 ppm) having a larger shift and therefore a higher speed. For a given magnification, the speed is constant.

[0130] In one embodiment, additional use of beam steering and / or micro-wafer positioning can be used to compensate for small translational and / or rotational differences between the mask and the wafer identified during the alignment routine. For example, if the wafer is translated relative to the mask, the wafer can be repositioned to be directly under the mask or beam steering can be used to compensate for the offset. This can also be applied to rotational differences. It can also be applied in situations where different alignment corrections are needed in the x-direction and the y-direction.

[0131] This specification also discloses the following items (embodiments):

[0132] 1. An optical system, comprising:

[0133] A lens system configured to receive first radiation associated with an object and to direct second radiation associated with an image of the object toward an image plane, the lens system comprising:

[0134] a first set of lenses configured to receive and selectively amplify the first radiation;

[0135] an actuator system configured to selectively adjust the first set of lenses to symmetrically adjust a magnification associated with the image along a first direction and a second direction; and

[0136] A beam steering lens is configured to direct the first radiation selectively magnified by the first set of lenses to provide the second radiation based at least on a tilt of the beam steering lens, wherein the tilt of the beam steering lens is adjustable by the actuator system.

[0137] 2. The optical system according to item 1, further comprising:

[0138] A lens assembly comprising a plurality of lenses;

[0139] a first prism configured to pass the first radiation to the lens assembly, wherein the first set of lenses is configured to pass the first radiation to the first prism;

[0140] a reflector configured to receive the first radiation from the first prism through the plurality of lenses of the lens assembly and reflect the first radiation; and

[0141] A second prism is configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane.

[0142] 3. An optical system as described in item 1, further comprising a second group of lenses configured to receive and selectively magnify the first radiation, wherein the actuator system is further configured to selectively adjust the second group of lenses to adjust the magnification along the first direction or the second direction, and wherein the beam guiding lens is configured to guide the first radiation selectively magnified by the first group of lenses and the second group of lenses to provide the second radiation based at least on the tilt of the beam guiding lens.

[0143] 4. The optical system according to item 3, further comprising:

[0144] A lens assembly comprising a plurality of lenses;

[0145] a first prism configured to transmit the first radiation to the lens assembly;

[0146] a reflector configured to receive the first radiation from the first prism through the plurality of lenses of the lens assembly and reflect the first radiation; and

[0147] a second prism configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane,

[0148] The first set of lenses is configured to pass the first radiation to the first prism, and the second prism is configured to pass the first radiation to the second set of lenses.

[0149] 5. The optical system of item 3, wherein:

[0150] the actuator system being configured to adjust the second group of lenses to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value to the magnification along the second direction,

[0151] The first magnification compensation value is different from the second magnification compensation value, and

[0152] The first direction is orthogonal to the second direction.

[0153] 6. The optical system of item 3, wherein the actuator system is configured to move at least one lens of the first set of lenses from a first position to a second position and / or to move at least one lens of the second set of lenses from a third position to a fourth position to adjust the magnification.

[0154] 7. The optical system of item 3, wherein the second set of lenses comprises a single lens, and wherein the actuator system is configured to bend and / or rotate the single lens to adjust the magnification.

[0155] 8. An optical system as described in item 1, wherein:

[0156] The optical system is a photolithography system;

[0157] The object includes a pattern of a mask;

[0158] The image plane includes the wafer;

[0159] The image includes a projection of the object on the wafer;

[0160] The optical system further includes a magnification controller configured to generate one or more control signals associated with adjustment of the magnification based at least on a position of the mask relative to a position of the wafer; and

[0161] The actuator system is configured to receive the one or more control signals and to cause the amplification adjustment in response to the one or more control signals.

[0162] 9. The optical system of item 8, further comprising a wafer positioning controller configured to adjust the position of the wafer relative to the position of the mask to shift the position of the image on the wafer.

[0163] 10. The optical system of item 8, wherein:

[0164] The lens system is configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer,

[0165] The actuator system is further configured to adjust the tilt of the beam directing lens in response to the one or more control signals, and

[0166] Each portion of the wafer is associated with a respective tilt of the beam steering lens.

[0167] 11. A method comprising:

[0168] receiving first radiation associated with an object;

[0169] directing the first radiation through at least a first set of lenses to obtain selectively magnified first radiation, wherein during directing the first radiation, the first set of lenses is selectively adjusted to symmetrically adjust a magnification associated with an image of the object along a first direction and a second direction; and

[0170] The selectively amplified first radiation is directed based at least on a tilt of the beam steering lens to provide second radiation toward an image plane.

[0171] 12. A method as described in item 11, wherein guiding the first radiation includes: guiding the first radiation through at least the first group of lenses and the second group of lenses to obtain the selectively amplified first radiation, wherein during guiding the first radiation, the second group of lenses is selectively adjusted to adjust the magnification along the first direction or the second direction.

[0172] 13. The method of item 12, wherein selectively adjusting the second group of lenses comprises selectively adjusting the second group of lenses to apply a first magnification compensation value along the first direction to the magnification and to apply a second magnification compensation value different from the first magnification compensation value along the second direction to the magnification.

[0173] 14. The method of item 11, wherein the first group of lenses comprises a plurality of lenses, and wherein selectively adjusting the first group of lenses comprises: adjusting a distance between at least two lenses of the plurality of lenses.

[0174] 15. The method according to item 11, wherein:

[0175] The object includes a pattern of a mask,

[0176] The image plane includes the wafer,

[0177] The image includes a projection of the object on the wafer, and

[0178] Directing the selectively amplified first radiation includes projecting each portion of the pattern onto a corresponding portion of the wafer.

[0179] 16. The method according to item 15, further comprising:

[0180] generating one or more control signals associated with adjustment of the magnification based at least on a position of the mask relative to a position of the wafer, wherein the first group of lenses is selectively adjusted based on the one or more control signals; and

[0181] A tilt of a beam directing lens is adjusted in response to the one or more control signals, wherein each portion of the wafer is associated with a respective tilt of the beam directing lens.

[0182] 17. A method comprising:

[0183] receiving radiation associated with the object;

[0184] The radiation is directed toward an image plane by at least a first lens group and a second lens group, wherein during the directing:

[0185] selectively adjusting the first group of lenses to symmetrically adjust a magnification associated with an image of the object along a first direction and a second direction; and

[0186] The second lens group is selectively adjusted to adjust the magnification along the first direction or the second direction.

[0187] 18. The method according to item 17, wherein:

[0188] The object includes a pattern of a mask,

[0189] The image plane includes the wafer,

[0190] The image includes a projection of the object on the wafer, and

[0191] Directing the radiation includes projecting each portion of the pattern onto a corresponding portion of the wafer.

[0192] 19. The method according to item 18, further comprising:

[0193] generating one or more control signals based at least on a position of the mask relative to a position of the wafer; and

[0194] A tilt of a beam directing lens is adjusted in response to the one or more control signals, wherein each portion of the wafer is associated with a respective tilt of the beam directing lens.

[0195] 20. An optical system comprising:

[0196] A lens system configured to receive first radiation associated with an object and to direct second radiation associated with an image of the object toward an image plane, the lens system comprising:

[0197] a first set of lenses configured to receive and selectively amplify the first radiation;

[0198] a second set of lenses configured to receive and selectively amplify the first radiation; and an actuator system configured to:

[0199] selectively adjusting the first set of lenses to symmetrically adjust a magnification associated with the image along a first direction and a second direction; and

[0200] The second lens group is selectively adjusted to adjust the magnification along the first direction or the second direction.

[0201] 21. An optical system as described in item 20, wherein the lens system further includes a beam guiding lens, which is configured to guide the first radiation to provide the second radiation based at least on a tilt of the beam guiding lens, and wherein the tilt of the beam guiding lens is capable of being adjusted by the actuator system.

[0202] 22. The optical system according to item 20, further comprising:

[0203] A lens assembly comprising a plurality of lenses;

[0204] a first prism configured to transmit the first radiation to the lens assembly;

[0205] a reflector configured to receive the first radiation from the first prism through the plurality of lenses of the lens assembly and reflect the first radiation; and

[0206] A second prism is configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane.

[0207] 23. The optical system of item 22, wherein the first set of lenses is configured to pass the first radiation to the first prism, and wherein the second prism is configured to pass the first radiation to the second set of lenses.

[0208] 24. The optical system of item 20, wherein:

[0209] the actuator system being configured to adjust the second group of lenses to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value to the magnification along the second direction,

[0210] The first magnification compensation value is different from the second magnification compensation value, and

[0211] The first direction is orthogonal to the second direction.

[0212] 25. The optical system of item 20, wherein the actuator system is configured to move at least one lens of the first set of lenses from a first position to a second position and / or to move at least one lens of the second set of lenses from a third position to a fourth position to adjust the magnification.

[0213] 26. The optical system of item 20, wherein:

[0214] The optical system is a photolithography system;

[0215] The object includes a pattern of a mask;

[0216] The image plane includes the wafer; and

[0217] The image includes a projection of the object on the wafer.

[0218] 27. The optical system of item 26, further comprising:

[0219] a beam steering lens configured to provide the second radiation based at least on a tilt of the beam steering lens,

[0220] in:

[0221] The lens system is configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer,

[0222] The actuator system is further configured to adjust the tilt of the beam directing lens in response to one or more control signals, and

[0223] Each portion of the wafer is associated with a respective tilt of the beam steering lens.

[0224] Software according to the present invention (such as non-transitory instructions, program code and / or data) may be stored on one or more non-transitory machine-readable media. It is also contemplated that the software identified herein may be implemented using one or more general or special purpose computers and / or computer systems (networked and / or otherwise). If applicable, the ordering of the various steps described herein may be changed, combined into composite steps and / or separated into sub-steps to provide the features described herein.

[0225] The above description is not intended to limit the invention to the precise form disclosed or to the specific field of use. The embodiments described above illustrate but do not limit the invention. It is contemplated that various alternative embodiments and / or modifications of the invention (whether or not explicitly described or illustrated herein) may be made in view of the invention. Therefore, the scope of the invention is limited only by the appended claims.

Claims

1. An optical system, comprising: A lens system configured to receive first radiation associated with an object and direct second radiation associated with an image of the object toward an image plane, wherein the object comprises a pattern of a mask, the image plane is disposed on a wafer, and the image comprises a projection of the object on the wafer, the lens system comprising: a first set of lenses configured to receive and selectively amplify the first radiation, wherein the first set of lenses comprises three lenses; First Prism; a second set of lenses configured to receive and selectively amplify the first radiation; An actuator system configured to: selectively adjusting the first set of lenses to symmetrically adjust a magnification associated with the image along a first direction and a second direction; selectively adjusting the second lens group to asymmetrically adjust the magnification along the first direction and the second direction; and In response to one or more control signals, adjusting a tilt of a beam directing lens as the wafer is scanned; The beam directing lens is configured to direct the first radiation selectively magnified by the first and second lens groups to provide the second radiation based at least on the tilt of the beam directing lens; and The first set of lenses is configured to transmit the first radiation to the first prism.

2. The optical system of claim 1, further comprising: a lens assembly comprising a plurality of lenses, wherein the first prism is configured to transmit the first radiation to the lens assembly; a reflector configured to receive the first radiation from the first prism via the plurality of lenses of the lens assembly and reflect the first radiation; and A second prism is configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the beam directing lens and the image plane.

3. The optical system of claim 1, further comprising: a lens assembly comprising a plurality of lenses, wherein the first prism is configured to transmit the first radiation to the lens assembly; a reflector configured to receive the first radiation from the first prism via the plurality of lenses of the lens assembly and reflect the first radiation; and a second prism configured to receive the first radiation reflected from the reflector directly from the plurality of lenses of the lens assembly via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane, The second prism is configured to transmit the first radiation to the second set of lenses.

4. The optical system of claim 1, wherein: the actuator system being configured to adjust the second group of lenses to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value to the magnification along the second direction, The first magnification compensation value is different from the second magnification compensation value, and The first direction is orthogonal to the second direction.

5. The optical system of claim 1, wherein the actuator system is configured to move at least one lens in the first set of lenses from a first position to a second position and / or move at least one lens in the second set of lenses from a third position to a fourth position to adjust the magnification.

6. The optical system of claim 1, wherein the second set of lenses comprises a single lens, and wherein the actuator system is configured to bend and / or rotate the single lens to adjust the magnification.

7. The optical system of claim 1, wherein: The optical system is a photolithography system; The optical system further includes a magnification controller configured to generate the one or more control signals based at least on a position of the mask relative to a position of the wafer, wherein the one or more control signals are associated with adjustment of the tilt of the beam directing lens and with adjustment of the magnification; and The actuator system is configured to receive the one or more control signals and to cause adjustment of the amplification in response to the one or more control signals.

8. The optical system of claim 7, further comprising a wafer positioning controller configured to adjust the position of the wafer relative to the position of the mask to shift the position of the image on the wafer.

9. The optical system of claim 7, wherein: The lens system is configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer, the actuator system is configured to adjust the tilt of the beam directing lens in response to the one or more control signals further coordinated with movement of the wafer, and Each portion of the wafer is associated with a respective tilt of the beam steering lens.

10. A method comprising: receiving first radiation associated with an object, wherein the object comprises a pattern of a mask; directing the first radiation through at least a first set of lenses to obtain selectively magnified first radiation, wherein the first set of lenses includes three lenses, wherein during directing the first radiation, the first set of lenses is selectively adjusted to symmetrically adjust a magnification associated with an image of the object along a first direction and a second direction, wherein the image includes a projection of the object on a wafer, and wherein an image plane is disposed on the wafer; and directing the selectively amplified first radiation to provide second radiation toward the image plane by adjusting the tilt of a beam directing lens as the wafer is scanned, wherein directing the first radiation comprises: directing the first radiation through at least the first lens group, the first prism, and the second lens group to obtain the selectively amplified first radiation, wherein during directing the first radiation, the second lens group is selectively adjusted to asymmetrically adjust the magnification along the first direction and the second direction; The first lens group is positioned between the object and the first prism.

11. The method of claim 10, wherein selectively adjusting the second set of lenses comprises: The second group of lenses is selectively adjusted to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value different from the first magnification compensation value to the magnification along the second direction.

12. The method of claim 10, wherein the first set of lenses comprises a plurality of lenses, and wherein selectively adjusting the first set of lenses comprises: A distance between at least two lenses of the plurality of lenses is adjusted.

13. The method of claim 10, wherein: Directing the selectively amplified first radiation includes projecting each portion of the pattern onto a corresponding portion of the wafer.

14. The method of claim 13, further comprising: generating one or more control signals associated with adjustment of the magnification based at least on a position of the mask relative to a position of the wafer, wherein the first group of lenses is selectively adjusted based on the one or more control signals, wherein the adjustment is performed in response to the one or more control signals, Each portion of the wafer is associated with a corresponding tilt of the beam steering lens.

15. A method comprising: receiving radiation associated with the object; The radiation is directed toward an image plane by at least a first lens group, a first prism, and a second lens group, wherein during the directing: selectively adjusting the first set of lenses to symmetrically adjust a magnification associated with an image of the object along a first direction and a second direction; selectively adjusting the second lens group to asymmetrically adjust the magnification along the first direction and the second direction; and The first lens group includes three lenses, and the first lens group is positioned between the object and the first prism.

16. The method of claim 15, wherein: The object includes a pattern of a mask, The image plane includes the wafer, The image includes a projection of the object on the wafer, and Directing the radiation includes projecting each portion of the pattern onto a corresponding portion of the wafer.

17. The method of claim 16, further comprising: generating one or more control signals based at least on a position of the mask relative to a position of the wafer; and A tilt of a beam directing lens is adjusted in response to the one or more control signals, wherein each portion of the wafer is associated with a respective tilt of the beam directing lens.

18. An optical system comprising: A lens system configured to receive first radiation associated with an object and to direct second radiation associated with an image of the object toward an image plane, the lens system comprising: a first set of lenses configured to receive and selectively amplify the first radiation, wherein the first set of lenses comprises three lenses; a first prism configured to receive the selectively magnified first radiation from the first set of lenses, wherein the first set of lenses is positioned between the object and the first prism; a second set of lenses configured to receive and selectively amplify the first radiation; and An actuator system configured to: selectively adjusting the first set of lenses to symmetrically adjust a magnification associated with the image along a first direction and a second direction; and The second lens group is selectively adjusted to asymmetrically adjust the magnification along the first direction and the second direction.

19. The optical system of claim 18, wherein the lens system further comprises a beam steering lens configured to direct the first radiation to provide the second radiation based at least on a tilt of the beam steering lens, and wherein the tilt of the beam steering lens is adjustable by the actuator system.

20. The optical system of claim 18, further comprising: a lens assembly comprising a plurality of lenses, wherein the first prism is configured to transmit the first radiation to the lens assembly; a reflector configured to receive the first radiation from the first prism via the plurality of lenses of the lens assembly and reflect the first radiation; and A second prism is configured to receive the first radiation reflected from the reflector via the plurality of lenses of the lens assembly and direct the first radiation on an optical path toward the image plane.

21. The optical system of claim 20, wherein the first set of lenses is configured to pass the first radiation to the first prism, and wherein the second prism is configured to pass the first radiation to the second set of lenses.

22. The optical system of claim 18, wherein: the actuator system being configured to adjust the second group of lenses to apply a first magnification compensation value to the magnification along the first direction and a second magnification compensation value to the magnification along the second direction, The first magnification compensation value is different from the second magnification compensation value, and The first direction is orthogonal to the second direction.

23. The optical system of claim 18, wherein the actuator system is configured to move at least one lens in the first set of lenses from a first position to a second position and / or move at least one lens in the second set of lenses from a third position to a fourth position to adjust the magnification.

24. The optical system of claim 18, wherein: The optical system is a photolithography system; The object includes a pattern of a mask; The image plane includes the wafer; and The image includes a projection of the object on the wafer.

25. The optical system of claim 24, further comprising: a beam steering lens configured to provide the second radiation based at least on a tilt of the beam steering lens, in: The lens system is configured to project a corresponding portion of the pattern onto a corresponding portion of the wafer, The actuator system is further configured to adjust the tilt of the beam directing lens in response to one or more control signals, and Each portion of the wafer is associated with a respective tilt of the beam steering lens.

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