Optical devices and laser beam shape adjustment methods

Abstract

This invention belongs to the field of optical instrument technology, specifically relating to an optical device and a method for adjusting the shape of a laser beam. The optical device includes: a first cylindrical lens group, a second cylindrical lens group, a collimating lens, and a moving assembly. When the first cylindrical lens in the first cylindrical lens group moves relative to the second cylindrical lens, or vice versa, the divergence angle of the laser beam after focusing on the vertical plane is adjusted. When the third cylindrical lens in the second cylindrical lens group moves relative to the fourth cylindrical lens, or vice versa, the divergence angle of the laser beam after focusing on the horizontal plane is adjusted. This invention can independently change the divergence angle of the laser beam in the vertical and horizontal directions, thereby changing the diameter of the laser beam in both directions. It also enables the emission of parallel light, meeting different needs when detecting wafer defects and achieving optimal uniformity in detecting smaller defect signals.

Description

Technical Field

[0001] This invention belongs to the field of optical instrument technology, specifically relating to beam shaping devices, and more particularly to an optical device and a method for adjusting the shape of a laser beam. Background Technology

[0002] When inspecting wafer defects, the shape of the laser beam needs to be adjusted in order to perform a fast and accurate scan of the wafer. However, traditional optical devices can only adjust the divergence angle of the laser beam in the horizontal and vertical directions simultaneously through a single optical element. This results in the adjustment of the two directions being coupled together and unable to be optimized independently, which affects the quality of the laser beam.

[0003] Therefore, there is an urgent need to develop a new optical device and a laser beam shape adjustment method to solve the technical problem that the laser beam will couple with each other in the horizontal and vertical directions when the traditional optical device uses a single optical element to adjust the laser beam.

[0004] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0005] This disclosure provides at least one optical device and a method for adjusting the shape of a laser beam.

[0006] In a first aspect, embodiments of this disclosure provide an optical device comprising: a first cylindrical lens group, a second cylindrical lens group, a collimating lens, and a moving assembly; wherein the first cylindrical lens group and the second cylindrical lens group are respectively located between a laser and a collimating lens, and the first cylindrical lens group, the second cylindrical lens group, and the collimating lens are movably mounted on the moving assembly; when the laser emits a laser beam, the laser beam is focused on a vertical plane by the first cylindrical lens group, and the laser beam is focused on a horizontal plane by the second cylindrical lens group, until the laser beam reaches the collimating lens, so that the collimating lens collimates and corrects the laser beam; when the first cylindrical lens in the first cylindrical lens group is relative to the second cylindrical lens or the second cylindrical lens is relative to the first cylindrical lens on the moving assembly... During movement, to adjust the divergence angle of the laser beam after it is focused on the vertical plane, the first cylindrical lens group moves relative to the collimating lens on the moving assembly until the focusing point coincides with the focal length position of the collimating lens, and the size of the divergence angle is adjusted to change the diameter of the laser beam emitted from the collimating lens on the vertical plane; when the third cylindrical lens in the second cylindrical lens group moves relative to the fourth cylindrical lens or the fourth cylindrical lens relative to the third cylindrical lens on the moving assembly, to adjust the divergence angle of the laser beam after it is focused on the horizontal plane, the second cylindrical lens group moves relative to the collimating lens on the moving assembly until the focusing point coincides with the focal length position of the collimating lens, and the size of the divergence angle is adjusted to change the diameter of the laser beam emitted from the collimating lens on the horizontal plane.

[0007] In one optional embodiment, the cylindrical lens assembly includes: a first cylindrical lens and a second cylindrical lens; the first and second cylindrical lenses are horizontally arranged and movably mounted on a moving assembly, with the cylindrical surface of the first cylindrical lens facing the laser, the plane of the first cylindrical lens facing the plane of the second cylindrical lens, and the cylindrical surface of the second cylindrical lens facing the plane of the collimating lens; when the laser emits a laser beam toward the first cylindrical lens, the laser beam is focused on the vertical plane by the first and second cylindrical lenses until it reaches the collimating lens, so that the collimating lens collimates and corrects the laser beam; when the first cylindrical lens moves relative to the second cylindrical lens or the second cylindrical lens moves relative to the first cylindrical lens on the moving assembly, the divergence angle of the laser beam after focusing on the vertical plane is adjusted, and the first and second cylindrical lenses move relative to the collimating lens on the moving assembly until the focusing point coincides with the focal length position of the collimating lens, so that the laser beam emitted from the collimating lens is parallel to the laser beam emitted from the laser.

[0008] In one optional embodiment, the cylindrical lens assembly includes a third cylindrical lens and a fourth cylindrical lens. The third and fourth cylindrical lenses are vertically arranged and movably mounted on a moving assembly. The cylindrical surface of the third cylindrical lens faces the laser, the plane of the third cylindrical lens faces the plane of the fourth cylindrical lens, and the cylindrical surface of the fourth cylindrical lens faces the plane of the collimating lens. When the laser emits a laser beam toward the first cylindrical lens, the laser beam is focused horizontally by the first and second cylindrical lenses until it reaches the collimating lens, so that the collimating lens collimates and corrects the laser beam. When the third cylindrical lens moves relative to the fourth cylindrical lens or the fourth cylindrical lens moves relative to the third cylindrical lens on the moving assembly, the divergence angle of the laser beam after focusing on the horizontal plane is adjusted. When the third and fourth cylindrical lenses move together relative to the collimating lens on the moving assembly until the focusing point coincides with the focal length position of the collimating lens, the laser beam emitted from the collimating lens is parallel to the laser beam emitted from the laser.

[0009] In one alternative embodiment, the collimating lens is provided with a spherical surface to collimate and correct the laser beam emitted from the collimating lens, and the laser beam emitted from the collimating lens is parallel to the laser beam emitted from the laser.

[0010] In one optional implementation, the position of the collimating lens on the moving assembly and the focal length of the collimating lens are determined; the diameter of the laser beam emitted from the collimating lens on the vertical plane is determined to obtain the divergence angle of the laser beam after focusing on the vertical plane; the diameter of the laser beam emitted from the laser on the vertical plane is determined to obtain the focal length of the first cylindrical lens group; and the optical parameters of the first cylindrical lens and the position of the second cylindrical lens on the moving assembly are configured based on the focal length of the first cylindrical lens group.

[0011] In one optional implementation, the position of the collimating lens on the moving assembly and the focal length of the collimating lens are determined; the diameter of the laser beam emitted from the collimating lens on the horizontal plane is determined to obtain the divergence angle of the laser beam after focusing on the horizontal plane; the diameter of the laser beam emitted from the laser on the horizontal plane is determined to obtain the focal length of the second cylindrical lens group; and the optical parameters of the third cylindrical lens and the fourth cylindrical lens and their positions on the moving assembly are configured based on the focal length of the second cylindrical lens group.

[0012] In one optional embodiment, the moving component includes: a moving track; the first cylindrical lens group, the second cylindrical lens group, and the collimating lens are respectively snapped onto the moving track.

[0013] Secondly, this disclosure also provides a laser beam shape adjustment method as described above, comprising: when a laser emits a laser beam, the laser beam is focused on a vertical plane by a cylindrical lens group one, and the laser beam is focused on a horizontal plane by a cylindrical lens group two, until the laser beam reaches a collimating lens, so that the collimating lens collimates and corrects the laser beam; when the first cylindrical lens in the cylindrical lens group one moves relative to the second cylindrical lens or the second cylindrical lens relative to the first cylindrical lens on a moving assembly, the divergence angle of the laser beam after focusing on the vertical plane is adjusted, and the cylindrical lens group one moves relative to the collimating lens. The moving assembly moves until the focal point coincides with the focal length of the collimating lens, and the divergence angle is adjusted to change the diameter of the laser beam emitted from the collimating lens on the vertical plane. When the third cylindrical mirror in the second cylindrical mirror assembly moves relative to the fourth cylindrical mirror or the fourth cylindrical mirror moves relative to the third cylindrical mirror on the moving assembly, the divergence angle of the laser beam after focusing on the horizontal plane is adjusted. The second cylindrical mirror assembly moves relative to the collimating lens on the moving assembly until the focal point coincides with the focal length of the collimating lens, and the divergence angle is adjusted to change the diameter of the laser beam emitted from the collimating lens on the horizontal plane.

[0014] In one optional implementation, the position of the collimating lens on the moving assembly and the focal length of the collimating lens are determined; the diameter of the laser beam emitted from the collimating lens on the vertical plane is determined to obtain the divergence angle of the laser beam after focusing on the vertical plane; the diameter of the laser beam emitted from the laser on the vertical plane is determined to obtain the focal length of the first cylindrical lens group; and the optical parameters of the first cylindrical lens and the position of the second cylindrical lens on the moving assembly are configured based on the focal length of the first cylindrical lens group.

[0015] In one alternative implementation, the position of the collimating lens on the moving assembly and the focal length of the collimating lens are determined; the diameter of the laser beam emitted from the collimating lens on the horizontal plane is determined to obtain the divergence angle of the laser beam after focusing on the horizontal plane; the diameter of the laser beam emitted from the laser on the horizontal plane is determined to obtain the focal length of the second cylindrical lens group; and the optical parameters of the third cylindrical lens and the fourth cylindrical lens and their positions on the moving assembly are configured based on the focal length of the second cylindrical lens group.

[0016] The beneficial effects of this invention are that, by changing the positions of the first and second cylindrical mirrors in cylindrical mirror group one and the third and fourth cylindrical mirrors in cylindrical mirror group two, the divergence angle of the laser beam in the vertical and horizontal directions can be changed independently. Furthermore, by adjusting the positions of cylindrical mirror group one, cylindrical mirror group two, and collimating lens, the diameter of the laser beam in the vertical and horizontal directions can be changed, while also achieving parallel light emission. This meets different requirements when detecting wafer defects and enables the laser beam to detect smaller defect signals with optimal uniformity.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A structural diagram of an optical device provided in an embodiment of this disclosure;

[0021] Figure 2 This is a schematic diagram illustrating the adjustment of a laser beam in the vertical direction, as provided in an embodiment of this disclosure.

[0022] Figure 3 This is a schematic diagram illustrating the adjustment of a laser beam in the horizontal direction, as provided in an embodiment of this disclosure.

[0023] Figure 4 This is a schematic diagram illustrating a change in a laser beam, provided as an embodiment of this disclosure.

[0024] In the picture:

[0025] 1. Cylindrical mirror group one; 11. First cylindrical mirror; 111. First side view; 112. Second side view; 12. Second cylindrical mirror; 121. Third side view; 122. Fourth side view;

[0026] 2. Cylindrical mirror group two; 21. Third cylindrical mirror; 211. Fifth side view; 212. Sixth side view; 22. Fourth cylindrical mirror; 221. Seventh side view; 222. Eighth side view;

[0027] 3. Collimating lens; 31. Ninth side view; 32. Tenth side view;

[0028] 4. Moving components; 41. Moving tracks. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0031] In this document, when an element or layer is referred to as “located,” “joined to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly located, joined, connected, attached to, or coupled to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as “directly on another element or layer,” “directly joined to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items.

[0032] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0033] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0034] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0035] Research has revealed that as semiconductor manufacturing processes evolve towards smaller feature sizes, the demands on wafer defect detection technology are increasing. To ensure chip production yield and improve chip inspection productivity, rapid and accurate scanning of chips is required, ensuring the detection of defects at the nanometer scale within a short time. Currently, the primary method for accurately detecting nanometer-scale defects is dark-field detection, which detects nanometer-scale defects by collecting stray light generated when an illumination beam illuminates the wafer surface. Therefore, the ellipticity of the illumination beam is crucial. Higher ellipticity results in greater uniformity across the beam direction and higher system resolution, enabling the detection of even finer defect signals. Conversely, lower ellipticity affects the beam size and divergence angle in the horizontal and vertical directions, impacting the stray light signals collected after passing through a complex optical system.

[0036] Based on the above research, this disclosure provides an optical device and a laser beam shape adjustment method, which can improve the ellipticity of the laser beam and thus improve the uniformity of the beam in all directions to obtain higher system resolution, making the detection of small features and defects more sensitive. Cylindrical lens group one and cylindrical lens group two are used to control the beam size and beam waist position of the laser beam in the vertical and horizontal directions respectively. The divergence angles of the laser beam in the vertical and horizontal directions can be collimated and coincided by a collimating lens.

[0037] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventor's contribution to this disclosure.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] like Figures 1 to 4As shown, at least one embodiment provides an optical device comprising: a first cylindrical lens group 1, a second cylindrical lens group 2, a collimating lens 3, and a moving assembly 4; wherein the first cylindrical lens group 1 and the second cylindrical lens group 2 are respectively located between a laser and the collimating lens 3, and the first cylindrical lens group 1, the second cylindrical lens group 2, and the collimating lens 3 are respectively movably mounted on the moving assembly 4; when the laser emits a laser beam 5, the laser beam 5 is focused on the vertical plane by the first cylindrical lens group 1, and the laser beam 5 is focused on the horizontal plane by the second cylindrical lens group 2, until the laser beam 5 reaches the collimating lens 3, so that the collimating lens 3 collimates and corrects the laser beam 5; when the first cylindrical lens 11 in the first cylindrical lens group 1 is relative to the second cylindrical lens 12 or the second cylindrical lens 12 is relative to the first cylindrical lens 11 in the moving assembly 4, the device is positioned such that the first cylindrical lens 11 is positioned relative to the second cylindrical lens 12 or the second cylindrical lens 12 is positioned relative to the first cylindrical lens 11 in the moving assembly 4. When the cylindrical lens group 1 moves relative to the collimating lens 3 on the moving assembly 4, the divergence angle of the laser beam 5 after focusing on the vertical plane is adjusted. The cylindrical lens group 1 moves relative to the collimating lens 3 on the moving assembly 4 until the focusing point coincides with the focal length position of the collimating lens 3, and the divergence angle is adjusted to change the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane. When the third cylindrical lens 21 in the cylindrical lens group 2 moves relative to the fourth cylindrical lens 22 or the fourth cylindrical lens 22 moves relative to the third cylindrical lens 21 on the moving assembly 4, the divergence angle of the laser beam 5 after focusing on the horizontal plane is adjusted. The cylindrical lens group 2 moves relative to the collimating lens 3 on the moving assembly 4 until the focusing point coincides with the focal length position of the collimating lens 3, and the divergence angle is adjusted to change the diameter of the laser beam 5 emitted from the collimating lens 3 on the horizontal plane.

[0041] Specifically, the vertical component of the laser beam 5 can be focused by cylindrical mirror group 1, while the vertical component of the laser beam 5 will pass directly through cylindrical mirror group 2. Similarly, the horizontal component of the laser beam 5 can be focused by cylindrical mirror group 2, while the horizontal component of the laser beam 5 will pass directly through cylindrical mirror group 1, thereby enabling cylindrical mirror group 1 and cylindrical mirror group 2 to control the laser beam 5 in one direction respectively.

[0042] Specifically, a collimating lens 3 is used to collimate the laser beam 5 in two directions, and it can collimate the laser beam 5 with different divergence angles and produce laser beam 5 of different sizes.

[0043] In at least one embodiment, by changing the positions of the first cylindrical mirror 11 and the second cylindrical mirror 12 in cylindrical mirror group 1 and the third cylindrical mirror 21 and the fourth cylindrical mirror 22 in cylindrical mirror group 2, the divergence angle of the laser beam 5 in the vertical and horizontal directions can be changed individually. Furthermore, by adjusting the positions of cylindrical mirror group 1, cylindrical mirror group 2 and collimating lens 3, the diameter of the laser beam 5 in the vertical and horizontal directions can be changed, and parallel light can be emitted to meet different requirements when detecting wafer defects, so that the laser beam 5 can detect smaller defect signals with optimal uniformity.

[0044] In at least one embodiment, please refer to Figure 1 , Figure 2 The cylindrical lens assembly 1 includes a first cylindrical lens 11 and a second cylindrical lens 12. The first cylindrical lens 11 and the second cylindrical lens 12 are horizontally arranged and movably mounted on the moving assembly 4. The cylindrical surface of the first cylindrical lens 11 faces the laser, the plane of the first cylindrical lens 11 faces the plane of the second cylindrical lens 12, and the cylindrical surface of the second cylindrical lens 12 faces the plane of the collimating lens 3. When the laser emits a laser beam 5 towards the first cylindrical lens 11, the laser beam 5 is focused on the vertical plane by the first cylindrical lens 11 and the second cylindrical lens 12. The laser beam 5 is directed until it reaches the collimating lens 3, so that the collimating lens 3 collimates and corrects the laser beam 5. When the first cylindrical mirror 11 moves relative to the second cylindrical mirror 12 or the second cylindrical mirror 12 moves relative to the first cylindrical mirror 11 on the moving assembly 4, the divergence angle of the laser beam 5 after focusing on the vertical plane is adjusted. The first cylindrical mirror 11 and the second cylindrical mirror 12 move relative to the collimating lens 3 on the moving assembly 4 until the focusing point coincides with the focal length position of the collimating lens 3, so that the laser beam 5 emitted from the collimating lens 3 is parallel to the laser beam 5 emitted from the laser.

[0045] Specifically, the cylindrical surface of the first cylindrical mirror 11 is the first side surface 111, and the plane of the first cylindrical mirror 11 is the second side surface 112.

[0046] Specifically, the direction of the vertical portion of the laser beam 5 changes when it passes through the first side 111, while the direction of the vertical portion of the laser beam 5 does not change when it passes through the second side 112.

[0047] Specifically, the direction of the horizontal portion of the laser beam 5 does not change when it passes through the first side 111, and the direction of the horizontal portion of the laser beam 5 does not change when it passes through the second side 112.

[0048] Specifically, the plane of the second cylindrical mirror 12 is the third side surface 121, and the cylindrical surface of the second cylindrical mirror 12 is the fourth side surface 122.

[0049] Specifically, the direction of the vertical portion of the laser beam 5 does not change when it passes through the third side 121, while the direction of the vertical portion of the laser beam 5 changes when it passes through the fourth side 122.

[0050] Specifically, the direction of the horizontal portion of the laser beam 5 does not change when it passes through the third side 121, and the direction of the horizontal portion of the laser beam 5 does not change when it passes through the fourth side 122.

[0051] In at least one embodiment, please refer to Figure 1 , Figure 3 The cylindrical lens assembly 2 includes a third cylindrical lens 21 and a fourth cylindrical lens 22. The third cylindrical lens 21 and the fourth cylindrical lens 22 are vertically arranged and movably mounted on the moving assembly 4. The cylindrical surface of the third cylindrical lens 21 faces the laser, and the plane of the third cylindrical lens 21 faces the plane of the fourth cylindrical lens 22. The cylindrical surface of the fourth cylindrical lens 22 faces the plane of the collimating lens 3. When the laser emits a laser beam 5 towards the first cylindrical lens 11, the laser beam 5 is focused horizontally by the first cylindrical lens 11 and the second cylindrical lens 12. Until the laser beam 5 is directed to the collimating lens 3, so that the collimating lens 3 collimates and corrects the laser beam 5; when the third cylindrical mirror 21 moves relative to the fourth cylindrical mirror 22 or the fourth cylindrical mirror 22 moves relative to the third cylindrical mirror 21 on the moving assembly 4, the divergence angle of the laser beam 5 after focusing on the horizontal plane is adjusted, and when the third cylindrical mirror 21 and the fourth cylindrical mirror 22 move relative to the collimating lens 3 on the moving assembly 4 until the focusing point coincides with the focal length position of the collimating lens 3, so that the laser beam 5 emitted from the collimating lens 3 is parallel to the laser beam 5 emitted from the laser.

[0052] Specifically, the cylindrical surface of the third cylindrical mirror 21 is the fifth side surface 211, and the plane of the first cylindrical mirror 11 is the sixth side surface 212.

[0053] Specifically, the direction of the vertical portion of the laser beam 5 does not change when it passes through the fifth side 211, and the direction of the vertical portion of the laser beam 5 does not change when it passes through the sixth side 212.

[0054] Specifically, the direction of the horizontal portion of the laser beam 5 changes when it passes through the fifth side 211, while the direction of the horizontal portion of the laser beam 5 does not change when it passes through the sixth side 212.

[0055] Specifically, the plane of the fourth cylindrical mirror 22 is the seventh side surface 221, and the cylindrical surface of the second cylindrical mirror 12 is the eighth side surface 222.

[0056] Specifically, the direction of the vertical portion of the laser beam 5 does not change when it passes through the seventh side 221, and the direction of the vertical portion of the laser beam 5 does not change when it passes through the eighth side 222.

[0057] Specifically, the direction of the horizontal portion of the laser beam 5 does not change when it passes through the seventh side 221, while the direction of the horizontal portion of the laser beam 5 changes when it passes through the eighth side 222.

[0058] In at least one embodiment, the collimating lens 3 is provided with a spherical surface to collimate and correct the laser beam 5 emitted from the collimating lens 3, and the laser beam 5 emitted from the collimating lens 3 is parallel to the laser beam 5 emitted from the laser.

[0059] Specifically, the plane of the collimating lens 3 is the ninth side surface 31, and the spherical surface of the collimating lens 3 is the tenth side surface 32.

[0060] Specifically, the direction of the vertical portion of the laser beam 5 does not change when it passes through the ninth side surface 31, while the direction of the vertical portion of the laser beam 5 changes when it passes through the tenth side surface 32.

[0061] Specifically, the direction of the horizontal portion of the laser beam 5 does not change when it passes through the ninth side 31, while the direction of the horizontal portion of the laser beam 5 changes when it passes through the tenth side 32.

[0062] In at least one embodiment, the position of the collimating lens 3 on the moving component 4 and the focal length of the collimating lens 3 are determined; the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane is determined to obtain the divergence angle of the laser beam 5 after focusing on the vertical plane; the diameter of the laser beam 5 emitted from the laser on the vertical plane is determined to obtain the focal length of the cylindrical lens group 1; and the optical parameters of the first cylindrical lens 11 and the second cylindrical lens 12 and their positions on the moving component 4 are configured based on the focal length of the cylindrical lens group 1.

[0063] Specifically, please refer to Figure 2 According to the focal length of collimating lens 3 f 1 And the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane d 2 It can be derived from the formula θ 1 =arctan (d 2 / 2) / f 1 The divergence angle of the laser beam 5 after it is focused on the vertical plane can be calculated as follows: θ 1 Based on the diameter of the laser beam 5 emitted from the laser in the vertical plane... d 1 It can be derived from the formula f 2 = d 1 / 2tan θ 1 The focal length of cylindrical lens group 1 was calculated. f 2 The focal length of cylindrical lens group 1 f 2 It is possible to configure the optical parameters of the first cylindrical mirror 11 and the second cylindrical mirror 12 and their positions on the moving component 4.

[0064] Specifically, the optical parameters of the first cylindrical mirror 11 and the second cylindrical mirror 12 refer to the radius of curvature of the first side surface 111 and the radius of curvature of the fourth side surface 122.

[0065] In at least one embodiment, the position of the collimating lens 3 on the moving component 4 and the focal length of the collimating lens 3 are determined; the diameter of the laser beam 5 emitted from the collimating lens 3 on the horizontal plane is determined to obtain the divergence angle of the laser beam 5 after focusing on the horizontal plane; the diameter of the laser beam 5 emitted from the laser on the horizontal plane is determined to obtain the focal length of the second cylindrical lens group 2; and the optical parameters of the third cylindrical lens 21 and the fourth cylindrical lens 22 and their positions on the moving component 4 are configured based on the focal length of the second cylindrical lens group 2.

[0066] Specifically, please refer to Figure 3 According to the focal length of collimating lens 3 f 1 And the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane d 4 It can be derived from the formula θ 2 =arctan (d 4 / 2) / f 1 The divergence angle of the laser beam 5 after it is focused on the vertical plane can be calculated as follows: θ 2 Based on the diameter of the laser beam 5 emitted from the laser in the vertical plane... d 3 It can be derived from the formula f 3 = d 3 / 2tan θ 2 The focal length of cylindrical lens group 1 was calculated. f 3 The focal length of cylindrical lens group 1 f 3 It is possible to configure the optical parameters of the third cylindrical mirror 21 and the fourth cylindrical mirror 22 and their positions on the moving component 4.

[0067] Specifically, the optical parameters of the third cylindrical mirror 21 and the fourth cylindrical mirror 22 refer to the radius of curvature of the fifth side surface 211 and the radius of curvature of the eighth side surface 222.

[0068] Specifically, the ratio (beam expansion factor) between the diameter of the laser beam 5 emitted by the laser on the horizontal plane and the diameter of the laser beam 5 emitted by the collimating lens 3 on the horizontal plane is 0.75 to 1.25.

[0069] Specifically, the ratio (beam expansion factor) between the diameter of the laser beam 5 emitted by the laser in the vertical plane and the diameter of the laser beam 5 emitted by the collimating lens 3 in the vertical plane is 0.75 to 1.25.

[0070] Specifically, when the beam expansion factor of the laser beam 5 is 0.75 in both the horizontal and vertical planes, the radius of curvature of the first side 111 is 22.92 mm, the second side 112 is a plane, the third side 121 is a plane, and the radius of curvature of the fourth side 122 is 18.32 mm; the center thickness of the first cylindrical mirror 11 is 2.55 mm, and the center thickness of the second cylindrical mirror 12 is 2.7 mm; the center distance between the first cylindrical mirror 11 and the second cylindrical mirror 12 is 82.39 mm; the cylindrical mirror group 1 composed of the first cylindrical mirror 11 and the second cylindrical mirror 12 can independently control the divergence angle of the laser beam 5 in a single direction. The radius of curvature of the fifth side 211 is 45.85 mm, the sixth side 212 is a plane, the seventh side 221 is a plane, and the radius of curvature of the eighth side 222 is 11.45 mm; the center thickness of the third cylindrical mirror 21 is 2.27 mm, and the center thickness of the fourth cylindrical mirror 22 is 3.15 mm; the center distance between the third cylindrical mirror 21 and the fourth cylindrical mirror 22 is 115.33 mm; the cylindrical mirror group 2 composed of the third cylindrical mirror 21 and the fourth cylindrical mirror 22 can independently control the divergence angle of the laser beam 5 in another direction. The center-to-center distance between cylindrical mirror group 1 and cylindrical mirror group 2, i.e., the distance between the second cylindrical mirror 12 and the third cylindrical mirror 21, is 161.85 mm; at the same time, in order to accommodate the range of changes in beam size, the aperture of all cylindrical mirrors is 10 mm; the ninth side 31 is a plane, and the radius of curvature of the tenth side 32 is 183.39 mm; the center distance of collimating mirror 3 is 2.44 mm, and the center-to-center distance between collimating mirror 3 and the fourth cylindrical mirror 22 is 510.49 mm; in order to ensure that the divergence angle of the light is within the aperture of collimating mirror 3, the aperture of collimating mirror 3 is 25.4 mm.

[0071] Specifically, when the laser beam 5 has a beam expansion factor of 1.25 in both the horizontal and vertical planes, the radius of curvature of the first side 111 is 22.92 mm, the second side 112 is a plane, the third side 121 is a plane, and the radius of curvature of the fourth side 122 is 18.32 mm; the center thickness of the first cylindrical mirror 11 is 2.55 mm, and the center thickness of the second cylindrical mirror 12 is 2.7 mm; the center distance between the first cylindrical mirror 11 and the second cylindrical mirror 12 is 84.72 mm; the cylindrical mirror group 1 composed of the first cylindrical mirror 11 and the second cylindrical mirror 12 can independently control the divergence angle of the laser beam 5 in a single direction. The radius of curvature of the fifth side 211 is 45.85 mm, the sixth side 212 is a plane, the seventh side 221 is a plane, and the radius of curvature of the eighth side 222 is 11.45 mm; the center thickness of the third cylindrical mirror 21 is 2.27 mm, and the center thickness of the fourth cylindrical mirror 22 is 3.15 mm; the center distance between the third cylindrical mirror 21 and the fourth cylindrical mirror 22 is 118.21 mm; the cylindrical mirror group 2 composed of the third cylindrical mirror 21 and the fourth cylindrical mirror 22 can independently control the divergence angle of the laser beam 5 in another direction. The center-to-center distance between cylindrical mirror group 1 and cylindrical mirror group 2, i.e., the distance between the second cylindrical mirror 12 and the third cylindrical mirror 21, is 51.66 mm; at the same time, in order to accommodate the range of changes in beam size, the aperture of all cylindrical mirrors is 10 mm; the ninth side 31 is a plane, and the radius of curvature of the tenth side 32 is 183.39 mm; the center distance of collimating mirror 3 is 2.44 mm, and the center-to-center distance between collimating mirror 3 and the fourth cylindrical mirror 22 is 461.61 mm; in order to ensure that the divergence angle of the light is within the aperture of collimating mirror 3, the aperture of collimating mirror 3 is 25.4 mm.

[0072] Specifically, please refer to Figure 4 , Figure 4 The left image shows laser beam 5 with a horizontal beam expansion ratio of 1.25 and a vertical beam expansion ratio of 0.75, while the right image shows laser beam 5 with a horizontal beam expansion ratio of 1 and a vertical beam expansion ratio of 1.

[0073] In at least one embodiment, the moving component 4 includes: a moving track 41; the cylindrical lens group 1, the cylindrical lens group 2, and the collimating lens 3 are respectively snapped onto the moving track 41.

[0074] Based on the same technical concept, at least one embodiment also provides a laser beam shape adjustment method as described above, comprising: when the laser emits a laser beam 5, the laser beam 5 is focused on a vertical surface by a cylindrical lens group 1, and the laser beam 5 is focused on a horizontal surface by a cylindrical lens group 2, until the laser beam 5 reaches a collimating lens 3, so that the collimating lens 3 collimates and corrects the laser beam 5; when the first cylindrical lens 11 in the cylindrical lens group 1 moves relative to the second cylindrical lens 12 or the second cylindrical lens 12 moves relative to the first cylindrical lens 11 on the moving assembly 4, the divergence angle of the laser beam 5 after being focused on the vertical surface is adjusted, and the cylindrical lens group 1 moves relative to the collimating lens 3. The straight lens 3 moves on the moving assembly 4 until its focal point coincides with the focal length of the collimating lens 3, and the divergence angle is adjusted to change the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane. When the third cylindrical lens 21 in the cylindrical lens group 2 moves relative to the fourth cylindrical lens 22 or the fourth cylindrical lens 22 moves relative to the third cylindrical lens 21 on the moving assembly 4, the divergence angle of the laser beam 5 after focusing on the horizontal plane is adjusted. The cylindrical lens group 2 moves relative to the collimating lens 3 on the moving assembly 4 until its focal point coincides with the focal length of the collimating lens 3, and the divergence angle is adjusted to change the diameter of the laser beam 5 emitted from the collimating lens 3 on the horizontal plane.

[0075] In at least one embodiment, the position of the collimating lens 3 on the moving component 4 and the focal length of the collimating lens 3 are determined; the diameter of the laser beam 5 emitted from the collimating lens 3 on the vertical plane is determined to obtain the divergence angle of the laser beam 5 after focusing on the vertical plane; the diameter of the laser beam 5 emitted from the laser on the vertical plane is determined to obtain the focal length of the cylindrical lens group 1; and the optical parameters of the first cylindrical lens 11 and the second cylindrical lens 12 and their positions on the moving component 4 are configured based on the focal length of the cylindrical lens group 1.

[0076] In at least one embodiment, the position of the collimating lens 3 on the moving component 4 and the focal length of the collimating lens 3 are determined; the diameter of the laser beam 5 emitted from the collimating lens 3 on the horizontal plane is determined to obtain the divergence angle of the laser beam 5 after focusing on the horizontal plane; the diameter of the laser beam 5 emitted from the laser on the horizontal plane is determined to obtain the focal length of the second cylindrical lens group 2; and the optical parameters of the third cylindrical lens 21 and the fourth cylindrical lens 22 and their positions on the moving component 4 are configured based on the focal length of the second cylindrical lens group 2.

[0077] In summary, this invention, by changing the positions of the first and second cylindrical mirrors in cylindrical mirror group one and the third and fourth cylindrical mirrors in cylindrical mirror group two, can individually change the divergence angle of the laser beam in the vertical and horizontal directions. Furthermore, by adjusting the positions of cylindrical mirror group one, cylindrical mirror group two, and the collimating lens, it can change the diameter of the laser beam in the vertical and horizontal directions, while also achieving parallel beam emission. This meets different requirements when detecting wafer defects and enables the laser beam to detect smaller defect signals with optimal uniformity.

[0078] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0079] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.

[0080] Spatially relative terms, such as “inside,” “outside,” “below,” “below,” “down,” “above,” “up,” etc., may be used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. In addition to the orientations depicted in the figures, spatially relative terms may be intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “below” other elements or features would be oriented as “above” other elements or features. Thus, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0081] In the above discussion, unless otherwise stated, when used to describe numerical values, the terms “about,” “approximately,” “basically,” etc., indicate a change of + / - 10% in that value.

[0082] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An optical device, characterized in that, include: Cylindrical lens group one (1), cylindrical lens group two (2), collimating lens (3), and moving assembly (4); among which The first cylindrical lens group (1) and the second cylindrical lens group (2) are located between the laser and the collimating lens (3), and the first cylindrical lens group (1), the second cylindrical lens group (2), and the collimating lens (3) are movably mounted on the moving component (4); When the laser emits a laser beam (5), the laser beam (5) is focused on the vertical plane by the first cylindrical lens group (1), and the laser beam (5) is focused on the horizontal plane by the second cylindrical lens group (2) until the laser beam (5) hits the collimating lens (3) so that the collimating lens (3) collimates and corrects the laser beam (5). When the first cylindrical mirror (11) in the cylindrical mirror group (1) moves relative to the second cylindrical mirror (12) or the second cylindrical mirror (12) moves relative to the first cylindrical mirror (11) on the moving assembly (4), the divergence angle of the laser beam (5) after focusing on the vertical plane is adjusted. The cylindrical mirror group (1) moves relative to the collimating mirror (3) on the moving assembly (4) until the focusing point coincides with the focal length position of the collimating mirror (3), and the size of the divergence angle is adjusted to change the diameter of the laser beam (5) emitted from the collimating mirror (3) on the vertical plane. When the third cylindrical mirror (21) in the second cylindrical mirror group (2) moves relative to the fourth cylindrical mirror (22) or the fourth cylindrical mirror (22) moves relative to the third cylindrical mirror (21) on the moving component (4), the divergence angle of the laser beam (5) after focusing on the horizontal plane is adjusted. The second cylindrical mirror group (2) moves relative to the collimating mirror (3) on the moving component (4) until the focusing point coincides with the focal length position of the collimating mirror (3), and the size of the divergence angle is adjusted to change the diameter of the laser beam (5) emitted from the collimating mirror (3) on the horizontal plane.

2. The optical device as claimed in claim 1, characterized in that, The cylindrical mirror assembly (1) includes: a first cylindrical mirror (11) and a second cylindrical mirror (12); The first cylindrical mirror (11) and the second cylindrical mirror (12) are horizontally arranged and movably mounted on the moving assembly (4), and the cylindrical surface of the first cylindrical mirror (11) is arranged facing the laser, the plane of the first cylindrical mirror (11) is arranged facing the plane of the second cylindrical mirror (12), and the cylindrical surface of the second cylindrical mirror (12) is arranged facing the plane of the collimating lens (3). When the laser emits a laser beam (5) toward the first cylindrical mirror (11), the laser beam (5) is focused on the vertical plane by the first cylindrical mirror (11) and the second cylindrical mirror (12) until the laser beam (5) hits the collimating mirror (3) so that the collimating mirror (3) collimates and corrects the laser beam (5); When the first cylindrical mirror (11) moves relative to the second cylindrical mirror (12) or the second cylindrical mirror (12) moves relative to the first cylindrical mirror (11) on the moving assembly (4), the divergence angle of the laser beam (5) after focusing on the vertical plane is adjusted. The first cylindrical mirror (11) and the second cylindrical mirror (12) move relative to the collimating mirror (3) on the moving assembly (4) until the focusing point coincides with the focal length position of the collimating mirror (3), so that the laser beam (5) emitted from the collimating mirror (3) is parallel to the laser beam (5) emitted from the laser.

3. The optical device as claimed in claim 1, characterized in that, The cylindrical mirror group two (2) includes: a third cylindrical mirror (21) and a fourth cylindrical mirror (22); The third cylindrical mirror (21) and the fourth cylindrical mirror (22) are vertically arranged and movably mounted on the moving assembly (4). The cylindrical surface of the third cylindrical mirror (21) faces the laser, the plane of the third cylindrical mirror (21) faces the plane of the fourth cylindrical mirror (22), and the cylindrical surface of the fourth cylindrical mirror (22) faces the plane of the collimating mirror (3). When the laser emits a laser beam (5) towards the first cylindrical mirror (11), the laser beam (5) is focused horizontally by the first cylindrical mirror (11) and the second cylindrical mirror (12) until the laser beam (5) hits the collimating mirror (3) so that the collimating mirror (3) collimates and corrects the laser beam (5). When the third cylindrical mirror (21) moves relative to the fourth cylindrical mirror (22) or the fourth cylindrical mirror (22) moves relative to the third cylindrical mirror (21) on the moving assembly (4), the divergence angle of the laser beam (5) after focusing on the horizontal plane is adjusted. When the third cylindrical mirror (21) and the fourth cylindrical mirror (22) move relative to the collimating mirror (3) on the moving assembly (4) until the focusing point coincides with the focal length position of the collimating mirror (3), the laser beam (5) emitted from the collimating mirror (3) is parallel to the laser beam (5) emitted from the laser.

4. The optical device as claimed in claim 1, characterized in that, The collimating mirror (3) is provided with a spherical surface to collimate and correct the laser beam (5) emitted from the collimating mirror (3), and the laser beam (5) emitted from the collimating mirror (3) is parallel to the laser beam (5) emitted from the laser.

5. The optical device as claimed in claim 1, characterized in that, Determine the position of the collimating lens (3) on the moving component (4) and the focal length of the collimating lens (3); Determine the diameter of the laser beam (5) emitted from the collimating lens (3) on the vertical plane in order to obtain the divergence angle of the laser beam (5) after it is focused on the vertical plane; Determine the diameter of the laser beam (5) emitted by the laser in the vertical plane to obtain the focal length of the cylindrical mirror group (1); The optical parameters of the first cylindrical lens (11) and the second cylindrical lens (12) and their positions on the moving assembly (4) are configured by the focal length of the cylindrical lens group (1).

6. The optical device as claimed in claim 1, characterized in that, Determine the position of the collimating lens (3) on the moving component (4) and the focal length of the collimating lens (3); Determine the diameter of the laser beam (5) emitted from the collimating lens (3) on the horizontal plane to obtain the divergence angle of the laser beam (5) after it is focused on the horizontal plane; Determine the diameter of the laser beam (5) emitted by the laser on the horizontal plane in order to obtain the focal length of the cylindrical mirror group two (2); The optical parameters of the third cylindrical lens (21) and the fourth cylindrical lens (22) and their positions on the moving assembly (4) are configured by the focal length of the second cylindrical lens group (2).

7. The optical device as claimed in claim 1, characterized in that, The moving component (4) includes: a moving track (41); The cylindrical mirror group one (1), cylindrical mirror group two (2), and collimating mirror (3) are respectively snapped onto the moving track (41).

8. A method for adjusting the shape of a laser beam using the optical device as described in any one of claims 1-7, characterized in that, include: When the laser emits a laser beam (5), the laser beam (5) is focused on the vertical plane by the first cylindrical lens group (1), and the laser beam (5) is focused on the horizontal plane by the second cylindrical lens group (2) until the laser beam (5) hits the collimating lens (3) so that the collimating lens (3) collimates and corrects the laser beam (5); When the first cylindrical mirror (11) in the cylindrical mirror group (1) moves relative to the second cylindrical mirror (12) or the second cylindrical mirror (12) moves relative to the first cylindrical mirror (11) on the moving assembly (4), the divergence angle of the laser beam (5) after focusing on the vertical plane is adjusted. The cylindrical mirror group (1) moves relative to the collimating mirror (3) on the moving assembly (4) until the focusing point coincides with the focal length position of the collimating mirror (3), and the size of the divergence angle is adjusted to change the diameter of the laser beam (5) emitted from the collimating mirror (3) on the vertical plane. When the third cylindrical mirror (21) in the cylindrical mirror group 2 (2) moves relative to the fourth cylindrical mirror (22) or the fourth cylindrical mirror (22) moves relative to the third cylindrical mirror (21) on the moving component (4), the divergence angle of the laser beam (5) after focusing on the horizontal plane is adjusted. The cylindrical mirror group 2 (2) moves relative to the collimating mirror (3) on the moving component (4) until the focusing point coincides with the focal length position of the collimating mirror (3), and the size of the divergence angle is adjusted to change the diameter of the laser beam (5) emitted from the collimating mirror (3) on the horizontal plane.

9. The laser beam shape adjustment method as described in claim 8, characterized in that, Determine the position of the collimating lens (3) on the moving component (4) and the focal length of the collimating lens (3); Determine the diameter of the laser beam (5) emitted from the collimating lens (3) on the vertical plane in order to obtain the divergence angle of the laser beam (5) after it is focused on the vertical plane; Determine the diameter of the laser beam (5) emitted by the laser on the vertical plane in order to obtain the focal length of the cylindrical mirror assembly (1); The optical parameters of the first cylindrical lens (11) and the second cylindrical lens (12) and their positions on the moving assembly (4) are configured by the focal length of the cylindrical lens group (1).

10. The laser beam shape adjustment method as described in claim 8, characterized in that, Determine the position of the collimating lens (3) on the moving component (4) and the focal length of the collimating lens (3); Determine the diameter of the laser beam (5) emitted from the collimating lens (3) on the horizontal plane in order to obtain the divergence angle of the laser beam (5) after it is focused on the horizontal plane; Determine the diameter of the laser beam (5) emitted by the laser on the horizontal plane in order to obtain the focal length of the cylindrical mirror group two (2); The optical parameters of the third cylindrical lens (21) and the fourth cylindrical lens (22) and their positions on the moving assembly (4) are configured by the focal length of the second cylindrical lens group (2).

Images