Spatial position adjusting mechanism and adjusting method of light receiving device
By designing the spatial position adjustment mechanism of the light receiving device, multiple degrees of freedom adjustment according to a specific defect type are realized, and the problem of insufficient adjustment freedom of the existing light receiving device is solved, and the accuracy and flexibility of wafer defect detection are improved.
Patent Information
- Application Number
- CN202510569566.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-04
- Publication Date
- 2025-07-22
AI Technical Summary
The existing light-receiving devices lack the adjustment degree of freedom and adjustment amplitude in wafer defect detection, and the light-receiving angle cannot be adjusted in real time according to a specific defect type, resulting in insufficient detection accuracy.
A spatial position adjustment mechanism of a light receiving device is designed, including a circumferential adjustment module and a channel adjustment module. The circumferential adjustment module and a channel adjustment module are used to adjust the circumferential light receiving angle and tendency light receiving angle of the light receiving device, and combine the intersection adjustment component and the pitch adjustment component to achieve multiple degrees of freedom.
It improves the flexibility and accuracy of wafer defect detection, and can meet the flexible detection needs of semiconductor manufacturers for specific types of defects.
Smart Images
Figure CN120352350A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of wafer measurement, and particularly relates to a spatial position adjustment mechanism and an adjustment method for a light receiving device. 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, and 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 be concentrated in the forward and backward directions of the incident light; when the particle size is larger, 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 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] Therefore, if the scattered light collection system can adjust the light receiving angle of the light receiving device according to the defect type and collect in the area where the scattered light is concentrated, the detection accuracy can be greatly improved. In practical applications, semiconductor manufacturers sometimes need to detect specific types of defects, but the adjustment freedom and adjustment range of the existing light receiving device are limited and cannot be adjusted in real time according to requirements, resulting in insufficient adjustment flexibility. Therefore, how to design a spatial position adjustment mechanism for the light receiving device to meet the requirement of adjusting the light receiving angle according to specific defect types is a technical problem to be solved in this field. Summary of the Invention
[0004] In order to solve the above technical problems, the present invention proposes a spatial position adjustment mechanism and an adjustment method for a light receiving device, and a spatial position adjustment module is arranged on the light receiving device to realize multi-degree-of-freedom adjustment of the light receiving device for specific defect types.
[0005] To achieve the above object, the spatial position adjustment mechanism of the light receiving device of the present invention includes a circumferential adjustment module and a channel adjustment module. The circumferential adjustment module is installed on the measurement device frame, the channel adjustment module is installed on the circumferential adjustment module, and the light receiving device is installed on the channel adjustment module. According to the position and incident angle of the incident light on the measurement device frame and based on the scattering principle of specific types of defects, the above-mentioned circumferential adjustment module drives the light receiving device to move along the circumferential direction of the wafer, transferring the light receiving device to the circumferential area where the scattered light energy is concentrated, that is, adjusting the circumferential light receiving angle of the light receiving device. The channel adjustment module adjusts the inclination light receiving angle of the light receiving device within the space range where the inclination angle with the wafer surface is greater than 0° and less than or equal to 90°. The above range covers the wide and narrow channels of scattered light commonly understood in the art; and the channel adjustment module adjusts the intersection point of the optical axis of the light receiving device and the wafer surface, so that the optical axis of the light receiving device passes through the light spot formed by the incident light on the wafer surface.
[0006] The circumferential adjustment module includes an annular track, a circumferential carrier, and a circumferential drive assembly. The annular track is laid in a ring at the wafer measurement station. The circumferential carrier is mounted on the annular track, and the circumferential drive assembly drives the circumferential carrier to move along the annular track to adjust the circumferential light receiving angle of the light receiving device. The channel adjustment module is installed on the circumferential carrier and includes a pitch adjustment component and an intersection point adjustment component. The pitch adjustment component is used to adjust the inclination angle between the optical axis of the light receiving device and the wafer surface to adjust the inclination light receiving angle of the light receiving device. In the plane including the circumferential light receiving angle and the inclination light receiving angle, the intersection point adjustment component adjusts the intersection point position of the optical axis of the light receiving device and the wafer surface by moving the light receiving device, so that the optical axis of the light receiving device passes through the light spot formed by the incident light on the wafer surface.
[0007] The intersection point adjustment component is connected to the pitch adjustment component. One of them is installed on the circumferential carrier, and the other is equipped with the light receiving device. When the intersection point adjustment component is installed on the circumferential carrier, the intersection point adjustment component drives the pitch adjustment component and the light receiving device to move as a whole, thereby adjusting the intersection point position of the optical axis of the light receiving device and the wafer surface. The pitch adjustment component is only used to adjust the pitch angle of the light receiving device. When the pitch adjustment component is installed on the circumferential carrier, the pitch adjustment component adjusts the overall pitch angle of the intersection point adjustment component and the light receiving device. The intersection point adjustment component is only used to adjust the intersection point position of the optical axis of the light receiving device and the wafer surface.
[0008] The intersection adjustment component or the pitch adjustment component and the circumferential bearing member can be installed together at a preset relative position. However, in order to increase the installation freedom between the intersection adjustment component or the pitch adjustment component and the circumferential bearing member and reduce the requirements for machining and installation accuracy, preferably, a swing adjustment component is provided between the intersection adjustment component or the pitch adjustment component and the circumferential bearing member. The swing adjustment component is used to adjust the swing angle of the intersection adjustment component or the pitch adjustment component relative to the circumferential bearing member so that the two reach the preset relative position, thereby reducing the requirements for machining and installation accuracy, or flexibly adjusting the circumferential light collection angle of the light collection device according to the position of the light spot of the incident light on the wafer surface.
[0009] Another object of the present invention is to provide a method for adjusting the spatial position of a light collection device. Using the aforementioned spatial position adjustment mechanism, it includes the following steps: a) Based on the scattering light principle of a specific type of defect and the incident angle of the incident light, determine the circumferential light collection angle and the inclined light collection angle of the light collection device; b) The above-mentioned circumferential drive component drives the circumferential bearing member to move along the annular track, and transfers the light collection device to the circumferential area where the scattering light energy is concentrated to adjust the circumferential light collection angle of the light collection device: c) The above-mentioned pitch adjustment component adjusts the inclination angle between the optical axis of the light collection device and the wafer surface to adjust the inclined light collection angle of the light collection device; d) In the plane including the circumferential light collection angle and the inclined light collection angle, the above-mentioned intersection adjustment component moves the light collection device to adjust the intersection position between the optical axis of the light collection device and the wafer surface, so that the optical axis of the light collection device passes through the light spot formed by the incident light on the wafer surface.
[0010] The technical effects of the present invention are as follows: The spatial position adjustment mechanism of the light collection device of the present invention can, based on the scattering light principle of a specific type of defect, transfer the light collection device to the circumferential area on the wafer surface where the scattering light energy is concentrated through the circumferential adjustment module, and in the above-mentioned circumferential area, adjust the inclination angle between the optical axis of the light collection device and the wafer surface through the pitch adjustment component to select an appropriate light collection angle within the wide and narrow channels of the scattering light. In addition, the intersection adjustment component adjusts the intersection position between the optical axis of the light collection device and the wafer surface, so that the optical axis of the light collection device passes through the light spot formed by the incident light on the wafer surface, thereby ensuring that the scattering light of the wafer defect smoothly enters the light collection device. The spatial position adjustment mechanism of the light collection device of the present invention improves the pertinence of wafer defect detection and can meet the flexible detection requirements of semiconductor manufacturers for specific types of defects. Description of the Drawings
[0011] Figure 1 It is the overall structure diagram of the spatial position adjustment mechanism of the light collection device.
[0012] Figure 2 It is the structure diagram of the circumferential adjustment module.
[0013] Figure 3 It is a structural diagram of a traction member.
[0014] Figure 4 It is a structural diagram of a circumferential load-bearing member and an annular track.
[0015] Figure 5 It is a structural diagram of a channel adjustment module.
[0016] Figure 6 It is a structural diagram of a pitch adjustment assembly.
[0017] Figure 7 It is a structural diagram of a swing adjustment assembly. Specific Embodiments
[0018] The following will describe in detail the specific embodiments of the present invention in conjunction with 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 intended to limit the present invention.
[0019] See Figures 1-6 , a spatial position adjustment mechanism of a light receiving device, including a circumferential adjustment module and a channel adjustment module, wherein the channel adjustment module is installed on the circumferential adjustment module, the circumferential adjustment module is installed on the measuring device frame 1, and the light receiving device 2 is installed on the channel adjustment module. The circumferential adjustment module includes an annular track 3, a circumferential load-bearing member 4, and a circumferential drive assembly. The annular track 3 is annularly laid on the measuring device frame 1, and the circumferential load-bearing member 4 is erected on the annular track 3.
[0020] Preferably, rollers 4-1 are installed at the bottom of the circumferential load-bearing member 4. The rollers 4-1 are located on both sides of the annular track 3. Flanges 3-1 are respectively provided on both sides of the annular track 3. Roller grooves 4-11 are provided on the circumferential surface of the rollers 4-1. The flanges 3-1 are embedded in the roller grooves 4-11. The circumferential load-bearing member 4 is erected on the annular track 3 by means of the flanges 3-1 and the roller grooves 4-11. The rollers 4-1 also play a guiding role for the circumferential load-bearing member 4 to facilitate its smooth movement on the annular track 3.
[0021] The circumferential drive assembly includes a drive member 5 and a traction member 6 mounted on the measuring device frame 1. The drive member 5 drives the traction member 6 to move linearly, and the traction member 6 drives the circumferential bearing member 4 to move along the annular track 3. The drive member 5 is selected from a linear motor, an electric push rod, a hydraulic rod, etc. The transmission type of the electric push rod is selected from a ball screw, a trapezoidal screw or a rack and pinion. The traction member 6 includes a fixed seat 6-1 and a sliding plate 6-2. The fixed seat 6-1 is fixed on the drive member 5, the sliding plate 6-2 is rotatably connected to the circumferential bearing member 4, and the sliding plate 6-2 is slidably connected to the fixed seat 6-1. When adjusting the circumferential light collection angle of the light collection device 2, the drive member 5 drives the fixed seat 6-1 to move linearly, and the sliding plate 6-2 pulls the circumferential bearing member 4 to move along the annular track 3. At the same time, as the distance between the circumferential bearing member 4 and the fixed seat 6-1 changes, the sliding plate 6-2 slides on the fixed seat 6-1.
[0022] Preferably, a slide rail 6-3 is provided between the sliding plate 6-2 and the fixed seat 6-1. The slide rail 6-3 is selected as two crossed roller guides, which are respectively located on both sides of the sliding plate 6-2. A groove is provided on the top surface of the fixed seat 6-1. The fixed part of the crossed roller guide is installed in the above groove, and the sliding part is installed on both sides of the sliding plate 6-2.
[0023] The channel adjustment module includes an intersection adjustment component 7 and a pitch adjustment component 8. The intersection adjustment component 7 is installed on the circumferential bearing member 4, the pitch adjustment component 8 is installed on the intersection adjustment component 7, and the light collection device 2 is installed on the pitch adjustment component 8. The intersection adjustment component 7 drives the pitch adjustment component 8 and the light collection device 2 to move as a whole, so as to adjust the intersection position of the optical axis of the light collection device 2 and the wafer surface. The pitch adjustment component 8 is used to adjust the pitch angle of the light collection device 2, so as to adjust the inclined light collection angle of the light collection device 2.
[0024] The intersection point adjustment component 7 drives the overall movement of the pitch adjustment component 8 and the light collection device 2 in the form of vertical displacement in this embodiment, so as to adjust the intersection point position between the optical axis of the light collection device 2 and the wafer surface, so that the optical axis of the light collection device 2 passes through the light spot formed by the incident light on the wafer surface. Based on the working principle of the intersection point adjustment component 7 described above, those skilled in the art can know that it is also feasible for the intersection point adjustment component 7 to move the light collection device in other directions within the plane including the circumferential light collection angle and the inclination light collection angle, and it still falls within the protection scope of this technical concept. The intersection point adjustment component 7 includes an intersection point component bracket 7-1 and a vertical displacement component 7-2. Among them, the intersection point component bracket 7-1 is installed on the circumferential carrier 4, the vertical displacement component 7-2 is installed on the intersection point component bracket 7-1, and the pitch adjustment component 8 is installed on the vertical displacement component 7-2. The vertical displacement component 7-2 is used to adjust the vertical position of the pitch adjustment component 8. The vertical displacement component 7-2 adopts a precision translation stage in the optical industry, including an electric translation stage or a manual translation stage. In this embodiment, the OMTOOLS manual translation stage series products are selected. The specific structure is briefly introduced here. It includes two opposite translation plates. The translation plates make relative translation with the help of crossed roller guides. A tension spring is also connected between the two translation plates. A micrometer head is installed on one translation plate. The micrometer head drives the other translation plate to translate against the tension of the tension spring, so as to adjust the vertical position of the pitch adjustment component 8. In addition, a locking component is also provided between the two translation plates to lock the relative positions of the two translation plates after the adjustment is in place.
[0025] The pitch adjustment component 8 includes a pitch adjustment plate 8-1 and a light collection device mounting bracket 8-2. The pitch adjustment plate 8-1 is installed on the vertical displacement component 7-2, and the light collection device 2 is installed on the light collection device mounting bracket 8-2. Among them, an arc-shaped groove 8-11 is opened on the pitch adjustment plate 8-1, and a guide post 8-21 is provided on the light collection device mounting bracket 8-2. The guide post 8-21 is embedded in the arc-shaped groove 8-11 and slides. Under the cooperation of the guide post 8-21 and the arc-shaped groove 8-11, the light collection device mounting bracket 8-2 rotates along the pitch adjustment plate 8-1, so as to drive the light collection device 2 to adjust its inclination light collection angle.
[0026] Preferably, two sets of light collection devices are provided on the measurement device frame 1 to improve the collection efficiency of the scattered light of the wafer defect.
[0027] See Figure 1 、 7, in order to increase the adjustment freedom degree between the intersection adjustment component 7 and the circumferential load-bearing component 4, preferably, a swing adjustment component 9 is provided between the intersection adjustment component 7 and the circumferential load-bearing component 4, which is used to adjust the swing angle of the intersection adjustment component 7 relative to the circumferential load-bearing component 4, so that the two reach a preset relative position, so as to reduce the requirements for processing and installation accuracy, or flexibly adjust the circumferential light collection angle of the light collection device 2 according to the spot position of the incident light on the wafer surface.
[0028] The swing adjustment component 9 adopts a precision rotary table in the optical industry, including an electric rotary table or a manual rotary table, and a manual rotary table is selected in the second embodiment. The swing adjustment component 9 includes a swing plate 9-1, and the swing plate 9-1 is rotatably connected to the circumferential load-bearing component 4 through a rotating shaft, and the intersection adjustment component 7 is installed on the swing plate 9-1. A top screw 9-2 is installed on one side of the circumferential load-bearing component 4, and the end of the top screw 9-2 abuts against the side surface of the swing plate 9-1, and the top screw 9-2 drives the swing plate 9-1 to rotate around the rotating shaft. A tension spring assembly is provided between the circumferential load-bearing component 4 and the swing plate 9-1. The tension spring assembly includes a tension spring 9-3 and a pull rod 9-4. The two ends of the tension spring 9-3 are respectively connected to the pull rod 9-4 on the circumferential load-bearing component 4 and the swing plate 9-1, and the top screw 9-2 drives the swing plate 9-1 to rotate relative to the circumferential load-bearing component 4 by overcoming the tension of the tension spring 9-3.
[0029] Preferably, a translation component 10 is further provided between the swing adjustment component 9 and the intersection adjustment component 7 to further optimize the adjustment freedom degree of the intersection adjustment component 7. The translation component 10 drives the intersection adjustment component 7 to move in a plane parallel to the circumferential load-bearing component 4. The translation component 10 adopts a precision translation stage in the optical industry, including an electric translation stage or a manual translation stage. In this embodiment, the OMTOOLS manual translation stage series products are selected. For the specific structure, see the above text, and two sets of OMTOOLS manual translation stages are stacked and installed to achieve translation adjustment in two mutually perpendicular directions.
[0030] The basic principle, main features and its advantages in the explored field of the present invention are described in detail above, and some usage examples are elaborated. Finally, it should be noted that: the above examples are only used to explain this patent 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 relevant technical parts. Therefore, any modification and equivalent replacement made within the spirit and principle of the present invention are within the protection scope of the claims of this invention patent.
Claims
1. Spatial position adjustment mechanism of a light collection device, comprising a circumferential adjustment module and a channel adjustment module. The circumferential adjustment module is installed on the measurement device frame, the channel adjustment module is installed on the circumferential adjustment module, and the light collection device is installed on the channel adjustment module. The circumferential adjustment module includes an annular track, a circumferential carrier, and a circumferential drive assembly. The annular track is laid on the measurement device frame, the circumferential carrier is mounted on the annular track, and the circumferential drive assembly drives the circumferential carrier to move along the annular track to adjust the circumferential light collection angle of the light collection device. The channel adjustment module includes a pitch adjustment assembly and an intersection point adjustment assembly. The pitch adjustment assembly is used to adjust the pitch light collection angle of the light collection device. In the plane including the circumferential light collection angle and the pitch light collection angle, the intersection point adjustment assembly is used to adjust the intersection point position of the optical axis of the light collection device and the wafer surface, so that the optical axis of the light collection device passes through the light spot formed by the incident light on the wafer surface. The intersection point adjustment assembly is connected to the pitch adjustment assembly, and one of them is installed on the circumferential carrier, and the other is equipped with the light collection device.
2. The spatial position adjusting mechanism of a light receiving device according to claim 1, characterized in that: The circumferential drive assembly includes a drive member and a traction member. The drive member is installed on the measurement device frame, the drive member drives the traction member to move linearly, and the traction member drives the circumferential carrier to move along the annular track. The drive member is selected from a linear motor, an electric push rod, or a hydraulic rod.
3. The spatial position adjusting mechanism of a light receiving device according to claim 2, characterized in that: The traction member includes a fixed seat and a sliding plate. The fixed seat is fixed on the drive member, the sliding plate is rotatably connected to the circumferential carrier, and the sliding plate is slidably connected to the fixed seat.
4. The spatial position adjustment mechanism of a light receiving device according to claim 1, characterized in that: The intersection point adjustment assembly is installed on the circumferential carrier. The intersection point adjustment assembly includes an intersection point assembly bracket and a displacement member. The intersection point assembly bracket is installed on the circumferential carrier, the displacement member is installed on the intersection point assembly bracket, and the pitch adjustment assembly is installed on the displacement member.
5. The spatial position adjusting mechanism of a light receiving device according to claim 4, characterized in that: The displacement member is selected as a vertical displacement member, and the vertical displacement member uses an electric translation stage or a manual translation stage.
6. The spatial position adjustment mechanism of a light receiving device according to claim 5, characterized in that: The pitch adjustment assembly includes a pitch adjustment plate and a light collection device mounting bracket. The pitch adjustment plate is installed on the vertical displacement member, and the light collection device is installed on the light collection device mounting bracket. An arc-shaped groove is formed on the pitch adjustment plate, and a guide post is provided on the light collection device mounting bracket. The guide post is embedded in the arc-shaped groove and is slidably connected.
7. The spatial position adjustment mechanism of a light receiving device according to claim 1, characterized in that: A swing adjustment assembly is provided between the intersection point adjustment assembly or the pitch adjustment assembly and the circumferential carrier. The swing adjustment assembly is used to adjust the swing angle of the intersection point adjustment assembly or the pitch adjustment assembly relative to the circumferential carrier. The swing adjustment assembly uses an electric rotary table or a manual rotary table.
8. The spatial position adjusting mechanism of a light receiving device according to claim 7, characterized in that: The swing adjustment assembly includes a swing plate, and the swing plate is rotatably connected to the circumferential carrier. A tightening screw is installed on one side of the circumferential carrier, and the end of the tightening screw abuts against the side surface of the swing plate. A tension spring assembly is provided between the circumferential carrier and the swing plate. The tension spring assembly includes a tension spring and tie rods located at both ends of the tension spring. The tie rods are respectively arranged on the circumferential carrier and the swing plate.
9. The spatial position adjustment mechanism of a light receiving device according to claim 7, characterized in that: A translation component is provided between the swing adjustment component and the intersection point adjustment component or the pitch adjustment component. The translation component drives the intersection point adjustment component or the pitch adjustment component to move in a plane parallel to the circumferential bearing member. The translation component uses an electric translation stage or a manual translation stage.
10. A method for adjusting the spatial position of a light receiving device, characterized in that: The spatial position adjustment mechanism of the light receiving device adopting the light receiving device according to any one of claims 1-9 includes the following steps: a) Based on the scattering light principle of a specific type of defect and the incident angle of the incident light, determine the circumferential light receiving angle and the inclined light receiving angle of the light receiving device; b) The circumferential driving component drives the circumferential bearing member to move along the annular track, and transfers the light receiving device to the circumferential area where the scattering light energy is concentrated, so as to adjust the circumferential light receiving angle of the light receiving device: c) The pitch adjustment component adjusts the inclination angle between the optical axis of the light receiving device and the wafer surface, so as to adjust the inclined light receiving angle of the light receiving device; d) In the plane including the circumferential light receiving angle and the inclined light receiving angle, the intersection point adjustment component moves the light receiving device to adjust the intersection position between the optical axis of the light receiving device and the wafer surface, so that the optical axis of the light receiving device passes through the light spot formed by the incident light on the wafer surface.