A multi-channel optical path installation mechanism

Abstract

The present invention provides a multi-channel optical path installation mechanism, which includes a measurement device frame and one or two light-emitting devices and a plurality of light-receiving devices arranged on the measurement device frame. The plurality of light-receiving devices are arranged within a space range with an inclination angle greater than 0° and less than 180° with respect to the wafer surface. Adjusting mechanisms are respectively provided on the light-emitting device and the light-receiving device. The adjusting mechanism includes a support base and a floating disk. The support base is fixed on the measurement device frame, the floating disk is floatingly connected to the support base, and the lens barrel is installed on the floating disk. The floating disk drives the lens barrel to move to adjust the light-emitting and light-receiving angles. A driving part is provided on the front side and the end side of the adjusting mechanism. The driving part includes a lateral driving part and a vertical driving part. The lateral driving part drives at least a part of the floating disk to move along the end face of the support base, and the vertical driving part is used to adjust the distance and inclination of the floating disk relative to the support base to change the height of the floating disk in the normal direction of the end face of the support base and the swing angle of the floating disk.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer measurement, and particularly to a multi-channel optical path installation mechanism. Background Art

[0002] One of the current wafer surface measurement technologies is to use a laser to scan a rapidly rotating wafer, and a light receiving device is used to collect the reflected light (specular reflection or diffuse reflection) on the wafer surface. Defect detection or size measurement is performed based on the collected reflected light. When used for wafer surface defect detection, the distribution of scattered light of different types of defects is different. For example, when the surface defect is a particle, the smaller the particle size, the lower the scattered energy. When the defect radius r satisfies 2πr / λ < 0.3 (where λ is the wavelength of the incident light), it shows Rayleigh scattering, and the scattered light energy tends to concentrate in the forward and reverse directions of the incident light; when the particle size is large, the scattered light intensity is large. When the defect radius r satisfies 2πr / λ > 1, it shows Mie scattering, which is usually concentrated in the forward direction of the incident light. The part of the scattered light close to the wafer surface is called wide-channel scattered light, and the part close to the normal line of the wafer surface is called narrow-channel scattered light. According to the different incident angles of the incident light, the scattered light of different types of defects is concentrated in the wide channel or the narrow channel.

[0003] For the scattered light collection system, it is necessary to collect as much wide-channel scattered light and narrow-channel scattered light as possible to comprehensively characterize the defect characteristics and achieve the purpose of accurately identifying the defect type. For this reason, it is usually required that the objective lens has a large light collection angle, that is, a large numerical aperture (Na). However, when the numerical aperture is above 0.9, it requires a complex optical component structure to simultaneously achieve a high focusing resolution for the wide and narrow channel scattered lights on the same focal plane, and the wide and narrow channel scattered lights are prone to interfere with each other, and at the same time, the signal-to-noise ratio is low, affecting the detection accuracy.

[0004] In order to avoid the interference between the wide and narrow channel scattered lights and improve the signal-to-noise ratio, using a multi-channel optical collection system is one of the solutions. Due to the precision errors in processing and assembly, after the installation is completed, it is necessary to adjust the optical paths of the light emitting and light receiving devices to meet the angular requirements of the measurement light. However, the multi-channel optical path structure results in a compact installation space for the wafer measurement device, and it is impossible to adjust the light emitting and light receiving devices from multiple directions, resulting in poor adjustability degrees of freedom. Moreover, the existing adjustment mechanisms have complex structures and large occupied spaces, and are not suitable for the narrow installation environment of the wafer measurement device. Therefore, how to design the adjustment mechanisms for the light emitting and light receiving devices to meet the multi-degree-of-freedom adjustment requirements in a narrow space is a technical problem that needs to be solved in this field. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a multi-channel optical path installation mechanism, which optimizes the internal structure of the adjustment mechanism and arranges the driving part of the adjustment mechanism on an easily operable end surface, so as to achieve multi-degree-of-freedom adjustment of the light-emitting and light-receiving devices in the narrow space of the measurement device frame.

[0006] To achieve the above object, the multi-channel optical path installation mechanism of the present invention includes a measurement device frame, one or two light-emitting devices and a plurality of light-receiving devices, wherein the light-emitting devices and the light-receiving devices are installed on the measurement device frame; the light-emitting device is installed in the normal direction of the wafer surface and / or in an inclined direction close to the wafer surface; the plurality of light-receiving devices are arranged in a space range with an inclination angle to the wafer surface greater than 0° and less than 180°, covering the wide and narrow channel scattering optical paths commonly understood in the art.

[0007] Due to the multi-channel design of the measurement device, the installation space is narrow. To facilitate the adjustment of the spatial angles of the light-emitting device and the light-receiving device, adjustment mechanisms are respectively provided on the light-emitting device and the light-receiving device. The adjustment mechanism includes a support seat and a floating disk. The support seat is fixed on the measurement device frame, the floating disk is floatingly connected to the support seat, and the lens barrel is installed on the floating disk. The floating disk drives the lens barrel to move to adjust the light-emitting and light-receiving angles. An operation space is left on the front side (the front side in the present invention refers to the side that is not interfered by other components and is convenient for operation) and the end side of the adjustment mechanism, and the driving part is arranged on the front side and the end side of the adjustment mechanism. The driving part includes a transverse driving part and a vertical driving part. The transverse driving part drives at least a part of the floating disk to move along the end surface of the support seat, and the vertical driving part is used to adjust the distance and inclination of the floating disk relative to the support seat, so as to change the height of the floating disk in the normal direction of the end surface of the support seat and the swing angle of the floating disk.

[0008] As one of the preferred ways of the adjustment mechanism, the transverse driving part is arranged on the front side of the support seat, and the vertical driving part is arranged on the end side of the floating disk. A receiving cavity is provided in the middle of the support seat. The floating disk includes a top plate and a contact sleeve located on the end surface of the top plate. The contact sleeve is inserted into the receiving cavity, and a vertical driving part is provided between the top plate and the end surface of the support seat. The transverse driving part includes two transverse driving members, the two transverse driving members are spaced apart along the circumferential direction of the support seat, and the transverse driving members are in contact with the contact sleeve for driving the contact sleeve; an elastic support member is provided at a position in the receiving cavity where the force applied by the transverse driving member is balanced, and the elastic support member abuts against the contact sleeve to provide elastic support for the contact sleeve, ensuring that when the transverse driving member drives the contact sleeve, the contact sleeve can move in the receiving cavity and can maintain stability. The vertical driving part includes a vertical driving member, and the vertical driving member drives the top plate to move along the normal direction of the end surface of the support seat or adjusts the swing angle of the top plate relative to the above normal line.

[0009] As another preferred embodiment of the adjustment mechanism, the lateral drive part is arranged on the front side of the floating disk, and the vertical drive part is arranged on the front side of the support base and the end side of the floating disk. The floating disk includes a floating body and a lens barrel carrier. An accommodation cavity is provided in the middle of the floating body, and at least part of the lens barrel carrier is located in the accommodation cavity. The lens barrel is installed on the lens barrel carrier. The lateral drive part includes two lateral drive members located on the front side of the floating body. The two lateral drive members are spaced apart along the circumferential direction of the floating body. The lateral drive member abuts against the lens barrel carrier to drive the lens barrel carrier. An elastic support member is provided at a position in the accommodation cavity where the force applied by the lateral drive member is balanced. The elastic support member abuts against the lens barrel carrier to provide elastic support for the lens barrel carrier, ensuring that when the lateral drive member drives the lens barrel carrier, the lens barrel carrier can move in the accommodation cavity and remain stable.

[0010] The vertical drive part includes two front vertical drive parts located on the front side of the support base and one end vertical drive member located on the end side of the floating body, or one front vertical drive part located on the front side of the support base and two end vertical drive members located on the end side of the floating body. The front vertical drive part includes a front vertical drive member and a steering member located inside the support base. The front vertical drive member drives the steering member, and the steering member abuts against the end face of the floating body. The steering member converts the movement of the front vertical drive member into an abutting movement against the floating body. The end vertical drive member is installed on the end side of the floating body and passes through the floating body to abut against the end face of the support base. The above-mentioned front vertical drive part and end vertical drive member are arranged at intervals along the circumferential direction of the adjustment mechanism.

[0011] The above-mentioned drive member can be an electric drive member, such as an electric telescopic rod, or a manual drive member, such as a tightening screw, or a hydraulic drive member, such as a hydraulic telescopic rod, as long as it can be placed in the space on the front side and end side of the adjustment mechanism, which is within the technical concept of the present invention.

[0012] The technical effects of the present invention are as follows:

[0013] The adjustment mechanism of the multi-channel optical path installation mechanism of the present invention arranges the drive part on the front side and the end side, and can perform multi-degree-of-freedom adjustment of the lens barrel from both sides, solving the drawback of the need to adjust from multiple sides in the prior art. Moreover, the drive part has a simple structure, reducing the volume of the adjustment module and facilitating installation in the narrow space of the measurement device rack. Description of the Drawings

[0014] Figure 1 is the overall structure diagram of the multi-channel optical path installation mechanism in the first embodiment.

[0015] Figure 2 is the structure diagram of the adjustment mechanism of the light-emitting device in the first embodiment.

[0016] Figure 3 is Figure 2 the cross-sectional view along the cutting line A-A in

[0017] Figure 4 It is a structural diagram of the adjustment mechanism of the light-receiving device in the first embodiment.

[0018] Figure 5 It is another view of the adjustment mechanism of the light-receiving device in the first embodiment.

[0019] Figure 6 It is a structural diagram of the second support base in the first embodiment.

[0020] Figure 7 It is a structural diagram of the second floating disk in the first embodiment.

[0021] Figure 8 It is a structural diagram of the adjustment mechanism of the light-emitting device in the second embodiment. Specific embodiments

[0022] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0023] Embodiment 1 Refer to Figures 1-7 , a multi-channel optical path installation mechanism, including a measurement device frame 3, a light-emitting device 14, and a light-receiving device 15. The light-emitting device 14 is located in the normal direction of the wafer surface, and 4 light-receiving devices 15 are arranged on both sides of the light-emitting device 14. Among them, the two light-receiving devices 15 close to the normal of the wafer surface are used to collect narrow-channel scattered light, and the two light-receiving devices 15 close to the wafer surface are used to collect wide-channel scattered light. The light-emitting device 14 and the light-receiving device 15 are provided with an adjustment mechanism for adjusting the angle of the measurement light.

[0024] The adjustment mechanism of the light-emitting device 14 includes a support base 1 and a floating disk 2. The support base 1 is fixed on the measurement device frame 3, and a light-emitting lens barrel 8 is connected to the floating disk 2. A lateral driving part is provided on the front side of the support base 1, and a vertical driving part is provided on the end side of the support base 1. An accommodation cavity 4 is provided in the middle of the support base 1. The floating disk 2 includes a top plate 5 and an abutting sleeve 6 located at the end face of the top plate 5. The abutting sleeve 6 is inserted into the accommodation cavity 4, and an incident hole 7 penetrating the top plate 5 and the abutting sleeve 6 is provided in the middle of the floating disk 2.

[0025] In the first embodiment, the driving members of the lateral driving portion and the vertical driving portion are selected as pressing screws. The lateral driving portion includes two lateral pressing screws 9 screwed to the front side of the support base 1. The lateral pressing screws 9 extend into the accommodating cavity 4 and abut against the abutting sleeve 6. The lateral pressing screws 9 move axially to drive the abutting sleeve 6 to move. An elastic support member 10 is provided at a position behind the support base 1 in the accommodating cavity 4. The elastic support member 10 abuts against the other side of the abutting sleeve 6. The two lateral pressing screws 9 cooperate to approach the abutting sleeve 6 simultaneously, or one approaches the abutting sleeve 6 while the other departs from the abutting sleeve 6 or remains stationary. Correspondingly, the elastic support member 10 is compressed or elongated to cooperate with the lateral pressing screws 9 to change the position of the floating disk 2 on the end face of the support base 1, thereby driving the light-emitting lens barrel 8 to move.

[0026] The vertical driving portion includes three vertical pressing screws 11. The three vertical pressing screws 11 are arranged at intervals along the circumferential direction of the support base 1. Among them, the vertical pressing screws 11 are screwed to the top plate 5, and the bottom ends of the vertical pressing screws 11 abut against the end face of the support base. The three vertical pressing screws 11 cooperate to approach or move away from the support base 1 simultaneously to change the height of the floating disk 2 in the normal direction of the end face of the support base; or some approach the support base 1 while some move away from the support base 1 or remain stationary to change the swing angle of the floating disk 2 relative to the normal of the end face of the support base. Correspondingly, the elastic support member 10 is compressed or elongated to cooperate with the inclination change of the floating disk 2. As one of the alternative ways, the three vertical pressing screws 11 are screwed to the side of the end of the support base, and the vertical pressing screws 11 are rotatably connected to the top plate 5 to drive the top plate 5 to move and change the swing angle of the top plate 5.

[0027] To increase the stability of the movement of the floating disk 2, preferably, an elastic connecting member is provided between the top plate 5 and the support base 1. The elastic connecting member includes two rod bodies 121 and an elastic body 122 located between the rod bodies 121. Among them, the rod bodies 121 are located in the grooves 13 on the opposite faces of the top plate 5 and the support base 1, and the elastic body 122 is located in the through holes of the top plate 5 and the support base 1. The elastic connecting member applies a pulling force to the floating disk 2 towards the support base 1 to facilitate the stable operation of the floating disk 2 under the drive of the lateral driving portion and the vertical driving portion.

[0028] The adjusting mechanism of the light-receiving device 15 includes a second support base 16 and a second floating disk. The second support base 16 is fixed on the measuring device frame 3, and the second floating disk is floatingly connected to the second support base 16. The second floating disk includes a floating body 17 and a lens barrel carrier 18. The lens barrel carrier 18 is movably installed on the floating body 17. A through light-receiving hole 19 is provided in the second support base 16, the floating body 17 and the lens barrel carrier 18. The light-receiving lens barrel 20 is installed on the lens barrel carrier 18, and the lens barrel carrier 18 drives the light-receiving lens barrel 20 to move to adjust the light-receiving angle.

[0029] Among them, the vertical driving part is arranged on the front side of the second support base 16 and the end side of the floating body 17, and includes two front vertical driving parts located on the front side of the second support base 16 and one end vertical driving part located on the end side of the floating body 17. The driving parts of the vertical driving part are selected as jacking screws. The two front vertical jacking screws 21 are spaced apart along the circumferential direction of the second support base 16 and are respectively screwed on the second support base 16. The end of the front vertical jacking screw 21 abuts against the steering part located inside the second support base 16. The steering part is selected as the steering ball 22. The steering ball 22 is driven by the front vertical jacking screw 21 to abut against the end face of the floating body 17. The moving direction of the steering ball 22 forms a 90° angle with the moving direction of the front vertical jacking screw 21. The end of the front vertical jacking screw 21 presses the steering ball 22, and the steering ball 22 moves toward the end face of the floating body 17 under extrusion to drive the floating disc.

[0030] One end vertical jacking screw 23 is installed on the end side of the floating body 17 and forms a triangular arrangement with the two front vertical jacking screws 21. The end vertical jacking screw 23 is screwed on the floating body 17. The end of the end vertical jacking screw 23 passes through the floating body 17 and abuts against the end face of the second support base 16 to drive the floating disc. The front vertical jacking screw 21 and the end vertical jacking screw 23 cooperate to change the height of the floating disc in the normal direction of the end face of the second support base 16 or change the swing angle of the floating disc. As one of the alternative methods, the end vertical jacking screw 23 is screwed on the end side of the second support base 16, and there is a rotational connection between the end vertical jacking screw 23 and the floating body 17, driving the floating body 17 to move and capable of changing the swing angle of the floating body 17.

[0031] The lateral driving part is arranged on the front side of the floating body 17 and includes two lateral driving parts located on the front side of the floating body 17. The lateral driving parts are selected as jacking screws. The two lateral jacking screws two 24 are spaced apart along the circumferential direction of the floating body 17 and are respectively screwed on the floating body 17. There is an accommodation cavity 25 in the middle of the floating body 17. One end of the lens barrel carrier 18 is located in the accommodation cavity 25. The end of one of the lateral jacking screws two 24 abuts against the lens barrel carrier 18, and the other lateral jacking screw two 24 abuts against the lateral steering part located inside the floating body 17. The lateral steering part is selected as the lateral steering ball 26. The lateral steering ball 26 is driven by the lateral jacking screw two 24 to abut against the lens barrel carrier 18. The moving direction of the lateral steering ball 26 forms a 90° angle with the moving direction of the lateral jacking screw two 24. An elastic support part two 27 is arranged at a position in the accommodation cavity 25 where the force applied by the lateral jacking screw two 24 is balanced. The elastic support part two 27 abuts against the lens barrel carrier 18 to provide elastic support for the lens barrel carrier 18, ensuring that the lens barrel carrier 18 can move stably in the accommodation cavity 25 when the lateral jacking screw two 24 drives the lens barrel carrier 18.

[0032] Since the driving part uses a tightening screw, in order to increase the stability of the movement of the second floating plate, especially in the first embodiment where the second floating plate is located below the second support base 16, an elastic connecting member II is provided between the floating body 17 and the second support base 16. The elastic connecting member II includes two rod bodies II 281 and an elastic body II 282 located between the rod bodies II 281. Among them, the rod bodies II 281 are located in the groove II 29 on the opposite side of the floating body 17 and the second support base 16, and the elastic body II 282 is located in the through hole of the floating body 17 and the second support base 16. The elastic connecting member II gives the second floating plate a pulling force towards the second support base 16, which is beneficial to the stable operation of the second floating plate driven by the tightening screw.

[0033] A sealing plate 29 is provided on the end face of the floating body 17. The sealing plate 29 blocks the end of the lens barrel carrier 18 in the accommodating cavity 25 to prevent it from detaching from the accommodating cavity 25.

[0034] Embodiment 2 Refer to Figure 8 , which is different from the first embodiment in that the floating plate 2 further includes an adjusting cylinder 30. The adjusting cylinder 30 is screwed in the incident hole 7, and the light-emitting lens barrel 8 is connected to the adjusting cylinder 30. In this way, the adjusting cylinder 30 moves up and down in the incident hole 7, and then drives the light-emitting lens barrel 8 to move up and down, increasing the stroke of the light-emitting lens barrel 8.

[0035] The basic principles, main features and its advantages in the explored field of the present invention have been described in detail above, and some usage examples have been elaborated. Finally, it should be noted that: the above examples are only used to explain the present invention and not to limit the present invention. Although we have described the present invention in detail with reference to the examples, those skilled in the art can still modify the described examples and solutions, or replace the relevant technical parts. Therefore, any modifications and equivalent replacements made within the spirit and principle of the present invention are within the protection scope of the claims of the present invention.

Claims

1. A multi-channel optical path installation mechanism, characterized in that: It includes a measurement device frame, one or two light-emitting devices, and multiple light-receiving devices, where the light-emitting devices and the light-receiving devices are installed on the measurement device frame; the light-emitting devices are installed in the normal direction of the wafer surface and / or in the inclined direction close to the wafer surface; multiple of the light-receiving devices are arranged within a space range with an inclination angle to the wafer surface greater than 0° and less than 180°; adjustment mechanisms are respectively provided on the light-emitting devices and the light-receiving devices, and the adjustment mechanism includes a support base and a floating disk. The support base is fixed on the measurement device frame, the floating disk is floatingly connected to the support base, and the lens barrel is installed on the floating disk; drive parts are provided on the front side and the end side of the adjustment mechanism; the drive part includes a lateral drive part and a vertical drive part. The lateral drive part drives at least a part of the floating disk to move along the end face of the support base; the vertical drive part is used to adjust the distance and inclination of the floating disk relative to the support base. The lateral drive part is arranged on the front side of the support base, and the vertical drive part is arranged on the end side of the floating disk; a receiving cavity is provided in the middle of the support base. The floating disk includes a top plate and an abutting sleeve located on the end face of the top plate. The abutting sleeve is inserted into the receiving cavity, and a vertical drive part is provided between the top plate and the end face of the support base; the lateral drive part includes two lateral drive members, and the two lateral drive members are spaced apart along the circumferential direction of the support base. The lateral drive member abuts against the abutting sleeve; an elastic support member is provided at a position in the receiving cavity where the force applied by the lateral drive member is balanced, and the elastic support member abuts against the abutting sleeve; the vertical drive part includes a vertical drive member, and the vertical drive member drives the top plate to move along the normal direction of the end face of the support base, or adjusts the swing angle of the top plate relative to the normal.

2. The multi-channel optical path installation mechanism according to claim 1, characterized in that: The end of one of the lateral drive members abuts against the abutting sleeve, and the other lateral drive member drives a lateral steering member located inside the support base. The lateral steering member abuts against the abutting sleeve, and the lateral steering member converts the movement of the lateral drive member into an abutting movement against the abutting sleeve.

3. The multi-channel optical path installation mechanism according to claim 1 or 2, characterized in that: The floating disk further includes an adjustment cylinder. A through incident hole is provided in the top plate and the abutting sleeve, and the adjustment cylinder is screwed into the incident hole, and the lens barrel is connected to the adjustment cylinder.

4. A multi-channel optical path installation mechanism according to claim 1 or 2, characterized in that: The lateral drive member and the vertical drive member are selected as set screws. The set screw located on the front side of the support base is screwed on the front side of the support base; the set screw located on the end side of the floating disk is screwed on the support base or the top plate. When the set screw is screwed on the end side of the support base, the set screw is rotatably connected to the top plate; when the set screw is screwed on the top plate, the set screw passes through the top plate and abuts against the end face of the support base.

5. The multi-channel optical path installation mechanism according to claim 4, characterized in that: An elastic connecting member is provided between the top plate and the support base. The elastic connecting member includes two rod bodies and an elastic body located between the rod bodies. The rod bodies are respectively located in the grooves on the opposite sides of the top plate and the support base, and the elastic body is located in the through holes of the top plate and the support base.

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