Coaxial cage type structure of transmitting end of ellipsometer

Abstract

The utility model relates to an ellipsometer transmitting end coaxial cage type structure which comprises an adjusting mechanism which comprises a positioning plate, a movable plate arranged on one side of the positioning plate, a first elastic piece with the two ends connected to the positioning plate and the movable plate respectively, and a plurality of first threaded rods with one ends penetrating through the movable plate in a threaded mode and extending to the positioning plate; the support mechanism comprises a first support, a second support and a third support, wherein the first support and the second support are arranged on the two sides of the movable plate respectively, and the third support is arranged at the end of the first support and extends towards one side of the movable plate. And the collimation mechanism comprises a first plate body which moves on the third bracket and a second plate body which is arranged on the first plate body. Through the arrangement, the coaxial arrangement of the incident optical fiber, the collimator, the polarizer and the lens cone can be kept, the center of the plane where the polarizer and the collimator are located is perpendicular to the central axis of the whole transmitting end, and the light incidence and detection precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ellipsometers, in particular to a coaxial cage structure for the transmitting end of an ellipsometer. Background Art

[0002] An ellipsometer is a device that observes the change in the polarization state of light when it is reflected or transmitted through the surface of a sample, and can thereby measure and calculate the optical constants (refractive index, extinction coefficient, etc.) of the sample. For example, in the case where there is a thin film on the surface of a wafer product, the thickness and optical constants of the thin film can be measured. One type of ellipsometer uses a transmitting end to make a parallel beam from a laser source or a beam converted into a parallel beam by a lens incident on the surface of the sample at an angle of about 70 degrees near the Brewster angle. Then, by observing the change in the polarization state before and after reflection, the film thickness and optical constants on the surface of the wafer can be measured.

[0003] The existing transmitting end can only adjust the inclination angle of the polarizer to maintain the coaxiality of the overall polarizer and the transmitting end, while the lens barrel for focusing and the collimator for collimation are fixed on the transmitting end, resulting in the inability to adjust the optical path coaxiality of the entire ellipsometer after installation. Especially when it is necessary to detect wafers from different angles, it is necessary to adjust the installation angle of the transmitting end on the ellipsometer. After the angle of the transmitting end changes, its center of gravity position and the stress angle of the internal components also change, causing a deviation in coaxiality and resulting in a reduction in detection accuracy. Summary of the Utility Model

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the problem in the prior art that after the angle of the transmitting end changes, its center of gravity position and the stress angle of the internal components also change, causing a deviation in coaxiality and resulting in a reduction in detection accuracy, thereby providing a coaxial cage structure for the transmitting end of an ellipsometer.

[0005] To solve the above technical problem, the utility model provides a coaxial cage structure for the transmitting end of an ellipsometer, including:

[0006] An adjusting mechanism, which includes: a positioning plate, a movable plate arranged on one side of the positioning plate, a first elastic member with two ends respectively connected to the positioning plate and the movable plate, and a plurality of first threaded rods with one end threadedly passing through the movable plate and extending to the positioning plate;

[0007] A bracket mechanism, which includes: a first bracket and a second bracket respectively arranged on both sides of the movable plate, a third bracket arranged at the end of the first bracket and extending towards the movable plate, a polarizer arranged at the end of the third bracket, and a lens barrel arranged on the second bracket;

[0008] A collimating mechanism, which includes: a first plate body movable on the third bracket, a second plate body provided on the first plate body, and an optical fiber collimator provided on the first plate body. The second plate body is fixedly provided on the third bracket. The optical fiber collimator is used to be connected to an incident optical fiber. The collimator, the polarizer, and the lens barrel are coaxially arranged.

[0009] In an embodiment of the present invention, a second adjusting mechanism is provided between the first plate body and the second plate body, which includes: a threaded bushing embedded in the first plate body, a second threaded rod threadedly engaged with the threaded bushing and extending towards the second plate body, a positioning ball rotatably connected to the second threaded rod, at least two positioning shafts rotatably connected to the second plate body, and a second elastic member with two ends respectively connected to the first plate body and the second plate body.

[0010] In an embodiment of the present invention, the first threaded rod and the second threaded rod are threadedly adjusted along the axial direction of the emission end. A plane adjusting mechanism is further provided on the first plate body and the second plate body. The plane adjusting mechanism is perpendicular to the adjusting directions of the first threaded rod and the second threaded rod.

[0011] In an embodiment of the present invention, the plane adjusting mechanism includes: a sleeve body embedded in the first plate body, plane through holes respectively opened on the first side and the second side of the first plate body, threaded bushings respectively embedded in the plane through holes, and third threaded rods threadedly engaged with the threaded bushings and abutting against the sleeve body. The axial directions of the third threaded rods on both sides are perpendicular to each other. The optical fiber collimator is fixed inside the inner ring of the sleeve body. The corresponding movable plate is also embedded with a threaded bushing adapted to the first threaded rod.

[0012] In an embodiment of the present invention, third elastic members are respectively abutted against the sleeve body away from the third threaded direction, and the first plate body is provided with receiving grooves for receiving the third elastic members.

[0013] In an embodiment of the present invention, positioning balls are also respectively rotatably connected to the ends of the first threaded rod and the third threaded rod. The first plate body is provided with an axial blind hole. A gasket is arranged in the axial blind hole. The positioning ball at the end of the first threaded rod abuts against the gasket, and the positioning ball at the end of the third threaded rod abuts against the sleeve body.

[0014] In an embodiment of the present invention, the first elastic member and the second elastic member are tension springs, and the third elastic member is a compression spring.

[0015] In an embodiment of the present utility model, the movable plate and the second plate body are respectively provided with first axial through holes penetrating the thickness. Two groups of the axial through holes are respectively provided with first locking members on the sides away from the positioning plate and the first plate body, and the positioning plate and the first plate body are provided with second locking members. Both ends of the first elastic member and the second elastic member are respectively connected to the first locking member and the second locking member.

[0016] In an embodiment of the present utility model, a locking plate is further provided between the positioning plate and the movable plate, and both ends of the locking plate are respectively fixedly connected to the positioning plate and the movable plate.

[0017] In an embodiment of the present utility model, the first plate body is provided with a second axial through hole for the third bracket to pass through, the movable plate is provided with a coaxial mounting plate, and the end of the second bracket is fixedly connected to the coaxial mounting plate.

[0018] The above technical solution of the present utility model has the following advantages compared with the prior art:

[0019] For the coaxial cage structure of the transmitting end of the ellipsometer described in the present utility model, the coaxial cage structure of the transmitting end is supported and installed on the ellipsometer through the positioning plate. The movable plate is movably connected to the positioning plate in an adjustable manner. The first elastic member provides an elastic pulling force between the positioning plate and the movable plate, so that the movable plate is tightly abutted against the positioning plate to maintain the assembly accuracy. The first bracket and the second bracket are respectively used to support the polarizer and the lens barrel, so that they are aligned on the same straight line, and the polarizer is arranged between the collimator and the lens barrel. The first threaded rod is threadedly connected to the movable plate and its end abuts against the positioning plate. Thus, by rotating, the rotation of the thread is converted into a linear motion to respectively adjust the inclination angles around the movable plate. Through a plurality of first threaded rods, fine adjustment of alignment and calibration is realized. The plurality of first threaded rods are distributed around the positioning plate, so that the base plane of the movable plate is perpendicular to the axis of the coaxial cage structure of the transmitting end. By changing the polarization state of the light through the polarizer, a fixed phase difference is formed. The incident optical fiber is refracted and focused through the lens barrel, so as to keep the incident optical fiber, the collimator, the polarizer and the lens barrel coaxially arranged, and the center of the plane where the polarizer and the collimator are located is perpendicular to the central axis of the entire transmitting end, improving the light incident and detection accuracy. Description of the Drawings

[0020] In order to make the content of the present utility model easier to be clearly understood, the following further details the present utility model according to the specific embodiments of the present utility model in conjunction with the drawings, where

[0021] Figure 1 is a schematic structural diagram of the transmitting end of the present utility model;

[0022] Figure 2 is the present utility model Figure 1 cross-sectional view;

[0023] Figure 3 is the perspective view of the collimating mechanism of the present utility model;

[0024] Figure 4 is the present utility model Figure 3 semi-sectional view;

[0025] Figure 5 is the sectional view of the adjusting mechanism of the present utility model;

[0026] Figure 6 is the perspective view of the support mechanism of the present utility model.

[0027] Explanation of the reference numerals in the drawings of the specification: 1. positioning plate; 2. movable plate; 3. first threaded rod; 4. first support; 5. second support; 6. mounting seat; 7. lens barrel; 8. third support; 9. first plate body; 10. second plate body; 11. second threaded rod; 12. third threaded rod; 13. incident optical fiber; 14. polarizer; 15. collimator; 16. second axial through hole; 17. receiving groove; 18. third elastic member; 19. positioning ball; 20. sleeve; 21. first axial through hole; 22. threaded bushing; 23. first locking member; 24. coaxial mounting plate; 25. second locking member. Detailed implementation manners

[0028] The present utility model will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present utility model and be able to implement it, but the embodiments cited do not limit the present utility model.

[0029] Embodiment

[0030] Referring to Figures 1-6 as shown, a coaxial cage structure of the transmitting end of an ellipsometer of the present utility model includes:

[0031] An adjusting mechanism, which includes: a positioning plate 1, a movable plate 2 disposed on one side of the positioning plate 1, a first elastic member with two ends respectively connected to the positioning plate 1 and the movable plate 2, and a plurality of first threaded rods 3 with one end threadedly passing through the movable plate 2 and extending to the positioning plate 1;

[0032] A support mechanism, which includes: a first support 4 and a second support 5 respectively disposed on both sides of the movable plate 2, a third support 8 disposed at the end of the first support 4 and extending towards the movable plate 2, a polarizer 14 disposed at the end of the third support 8, and a lens barrel 7 disposed on the second support 5;

[0033] A collimating mechanism, comprising: a first plate body 9 movable on the third bracket 8, a second plate body 10 provided on the first plate body 9, and an optical fiber collimator 15 provided on the first plate body 9. The second plate body 10 is fixedly provided on the third bracket 8. The optical fiber collimator 15 is used to be connected to the incident optical fiber 13. The collimator 15, the polarizer 14 and the lens barrel 7 are coaxially arranged.

[0034] A coaxial cage structure for the transmitting end of an ellipsometer according to the present invention. The coaxial cage structure for the transmitting end is supported and installed on the ellipsometer through a positioning plate 1. A movable plate 2 is movably connected to the positioning plate 1 in an adjustable manner. A first elastic member provides an elastic tension between the positioning plate 1 and the movable plate 2, so that the movable plate 2 is tightly abutted against the positioning plate 1 to maintain the assembly accuracy. A first bracket 4 and a second bracket 5 are respectively used to support the polarizer 14 and the lens barrel 7 to align them on the same straight line. And the polarizer 14 is arranged between the collimator 15 and the lens barrel 7. A first threaded rod 3 is threadedly connected to the movable plate 2 and its end abuts against the positioning plate 1. Thus, by rotating, the rotation of the thread is converted into a linear motion to respectively adjust the inclination angles around the movable plate 2. Through a plurality of first threaded rods 3, fine adjustment of alignment and calibration is realized. The plurality of first threaded rods 3 are distributed around the positioning plate 1, so that the base plane of the movable plate 2 is perpendicular to the axis of the coaxial cage structure of the transmitting end. By changing the polarization state of light through the polarizer 14, a fixed phase difference is formed. The incident optical fiber 13 is refracted and focused through the lens barrel 7. Thus, the incident optical fiber 13, the collimator 15, the polarizer 14 and the lens barrel 7 are coaxially arranged. And the center of the plane where the polarizer 14 and the collimator 15 are located is perpendicular to the central axis of the entire transmitting end, improving the light incident and detection accuracy.

[0035] Refer to Figures 1-2 、 Figure 5As shown, a second adjustment mechanism is provided between the first plate body 9 and the second plate body 10, which includes: a threaded bushing 22 embedded in the first plate body 9, a second threaded rod 11 threadedly engaged with the threaded bushing 22 and extending towards the second plate body 10, a positioning ball 19 rotatably connected to the second threaded rod 11, at least two positioning shafts rotatably connected to the second plate body 10, and a second elastic member with two ends respectively connected to the first plate body 9 and the second plate body 10. The second plate body 10 maintains a relative position with the first plate body 9 through the second threaded rod 11, the positioning ball 19 and the positioning shafts. When it is necessary to adjust the position of the second plate body 10, the operator can rotate the second threaded rod 11. Since there is a threaded engagement between the second threaded rod 11 and the threaded bushing 22, rotation will cause the second threaded rod 11 to move along its axial direction. The movement of the second threaded rod 11 will drive the second plate body 10 to move along the direction of the second threaded rod 11, thereby realizing the adjustment of the axial inclination angle of the fiber collimator 15, so that the emitted light ray remains on the axis of the emitting end. During the movement of the second plate body 10, the positioning ball 19 and the positioning shafts ensure that the movement of the second plate body 10 is smooth and stable. The positioning ball 19 reduces friction as the connection point between the second threaded rod 11 and the second plate body 10, and the positioning shafts provide support for the second plate body 10 to prevent it from tilting or swaying during the movement. The function of the second elastic member is similar to that of the first elastic member, pulling the second plate body 10 and the first plate body 9 to keep them in close fit.

[0036] Referring to Figures 1-5 As shown, the first threaded rod 3 and the second threaded rod 11 are adjusted threadedly along the axial direction of the emitting end. The first plate body 9 and the second plate body 10 are also provided with a planar adjustment mechanism. The adjustment direction of the planar adjustment mechanism is perpendicular to that of the first threaded rod 3 and the second threaded rod 11. Through the axial threaded adjustment of the first threaded rod 3 and the second threaded rod 11, the inclination angle adjustment of the optical component in the axial direction of the emitting end can be realized. By rotating the fine adjustment screw in the planar adjustment mechanism, the first plate body 9 and the second plate body 10 can be moved in the plane, thereby realizing the precise alignment of the optical component in the plane. By combining the axial adjustment and the in-plane fine adjustment, the precise position control of the optical component in the three-dimensional space can be realized, ensuring the collimation of the light beam and the precision of the optical path.

[0037] Referring to Figures 3-4As shown, the planar adjustment mechanism includes: a sleeve body 20 embedded in the first plate body 9, planar through holes respectively opened on the first side and the second side of the first plate body 9, threaded bushings 22 respectively embedded in the planar through holes, a third threaded rod 12 threadedly engaged with the threaded bushing 22 and abutted against the sleeve body 20. The axial directions of the two third threaded rods 12 are perpendicular to each other. The fiber collimator 15 is fixed inside the inner ring of the sleeve body 20. Threading the third threaded rod 12 into the threaded bushing 22, since the axial directions of the two third threaded rods 12 are perpendicular to each other, the collimator 15 can be adjusted in the plane, and this plane is perpendicular to the axis of the emitting end. By rotating the third threaded rod 12, the threaded rod squeezes the sleeve body 20 to displace and deform. The sleeve body 20 is made of a metal with certain elasticity, such as stainless steel or brass alloy, etc., and the position of the sleeve body 20 can be finely adjusted in the plane, so as to precisely adjust the position of the fiber collimator 15.

[0038] Referring to Figure 4 As shown, third elastic members 18 are respectively abutted against the sleeve body 20 away from the third threaded direction. The first plate body 9 is provided with a receiving groove 17 for receiving the third elastic member 18. In the traditional adjustment mechanism, the deformation of the sleeve body 20 itself can already provide the basic adjustment force. By introducing the third elastic member 18 and the receiving groove 17 of the first plate body 9, more precise optical alignment and collimation of parallel light beams can be achieved. This improved adjustment mechanism can provide a stable adjustment force during the whole measurement process, ensuring the collimation of the light beam and the measurement accuracy.

[0039] Referring to Figures 3-4 As shown, positioning balls 19 are also respectively rotatably connected to the ends of the first threaded rod 3 and the third threaded rod 12. The first plate body 9 is provided with an axial blind hole, and a gasket is arranged in the axial blind hole. The positioning ball 19 at the end of the first threaded rod 3 abuts against the gasket, and the positioning ball 19 at the end of the third threaded rod 12 abuts against the sleeve body 20. The gasket provides a support point for the positioning ball 19, and its hardness and wear resistance are higher than those of each plate body.

[0040] The first elastic member and the second elastic member are tension springs, and the third elastic member 18 is a compression spring. The first elastic member and the second elastic member are respectively used to tension the positioning plate 1 and the movable plate 2, the first plate body 9 and the second plate body 10, and the third elastic member 18 is used to make the sleeve body 20 elastically float.

[0041] Continuing to refer to Figures 3-4 As shown, the movable plate 2 and the second plate body 10 are respectively provided with first axial through holes 21 penetrating through the thickness. Two groups of the axial through holes are respectively provided with first locking members 23 on the sides away from the positioning plate 1 and the first plate body 9, and the positioning plate 1 and the first plate body 9 are provided with second locking members 25. The two ends of the first elastic member and the second elastic member are respectively connected to the first locking member 23 and the second locking member 25.

[0042] Referring to Figures 1-5 As shown, a locking plate is further provided between the positioning plate 1 and the movable plate 2. Both ends of the locking plate are fixedly connected to the positioning plate 1 and the movable plate 2 respectively. By providing the locking plate, after the positions of the positioning plate 1 and the movable plate 2 are adjusted, the relative movement between the positioning plate 1 and the movable plate 2 is prevented, and the positioning plate 1 and the movable plate 2 are locked. They are detachably locked by means such as bolt insertion and pin insertion. Since the positioning plate 1 is directly externally connected to the ellipsometer and the substrate as the transmitting end is subjected to greater force, a locking plate is provided for fixation.

[0043] Referring to Figure 5 As shown, the first plate body 9 is provided with a second axial through hole 16 for the third bracket 8 to pass through. The movable plate 2 is provided with a coaxial mounting plate 24. The end of the second bracket 5 is fixedly connected to the coaxial mounting plate 24, and the lens barrel 7 is mounted on the mounting seat 6.

[0044] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present utility model.

Claims

1. A coaxial cage structure at the transmitting end of an ellipsometer, characterized in that: include: The adjustment mechanism comprises: a positioning plate, a movable plate arranged on one side of the positioning plate, a first elastic member connected to the positioning plate and the movable plate at both ends, and a plurality of first threaded rods with one end threadedly penetrating the movable plate and extending to the positioning plate; A bracket mechanism, comprising: a first bracket and a second bracket respectively arranged on both sides of the movable plate, a third bracket arranged at an end of the first bracket and extending toward one side of the movable plate, a polarizer arranged at an end of the third bracket, and a lens barrel arranged at the second bracket; The collimation mechanism comprises: a first plate body movable on the third bracket, a second plate body arranged on the first plate body, and a fiber collimator arranged on the first plate body, the second plate body is fixedly arranged on the third bracket, the fiber collimator is used to be connected to the incident optical fiber, and the collimator, polarizer and lens barrel are coaxially arranged.

2. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 1, characterized in that: A second adjustment mechanism is arranged between the first plate body and the second plate body, and includes: a threaded bushing embedded in the first plate body, a second threaded rod threadedly engaged with the threaded bushing and extending toward the second plate body, a positioning ball rotatably connected to the second threaded rod, at least two positioning shafts rotatably connected to the second plate body, and a second elastic member whose two ends are respectively connected to the first plate body and the second plate body.

3. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 2, characterized in that: The first threaded rod and the second threaded rod are adjusted along the axial thread of the launch end. The first plate body and the second plate body are also provided with a plane adjustment mechanism. The plane adjustment mechanism is perpendicular to the adjustment direction of the first threaded rod and the second threaded rod.

4. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 3, characterized in that: The plane adjustment mechanism includes: a sleeve body embedded in the first plate body, planar through holes respectively opened on the first side and the second side of the first plate body, threaded bushings respectively embedded in the planar through holes, and a third threaded rod threadedly matched with the threaded bushing and abutting against the sleeve body, the directions of the axes of the third threaded rod on both sides are perpendicular, and the optical fiber collimator is fixed in the inner ring of the sleeve body.

5. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 4, characterized in that: The sleeve body is respectively in contact with third elastic members in a direction away from the third thread, and the first plate body is provided with a receiving groove for receiving the third elastic member.

6. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 1, characterized in that: The ends of the first threaded rod and the third threaded rod are also rotatably connected with positioning balls respectively. The first plate body is provided with an axial blind hole, and a gasket is arranged in the axial blind hole. The positioning ball at the end of the first threaded rod abuts against the gasket, and the positioning ball at the end of the third threaded rod abuts against the sleeve.

7. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 5, characterized in that: The first elastic member and the second elastic member are tension springs, and the third elastic member is a compression spring.

8. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 1, characterized in that: The movable plate and the second plate body are respectively provided with a first axial through hole that penetrates the thickness, and the two groups of axial through holes are respectively provided with a first locking piece on the side away from the positioning plate and the first plate body, and the positioning plate and the first plate body are provided with a second locking piece, and the two ends of the first elastic piece and the second elastic piece are respectively connected to the first locking piece and the second locking piece.

9. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 1, characterized in that: A locking plate is further arranged between the positioning plate and the movable plate, and two ends of the locking plate are respectively fixedly connected to the positioning plate and the movable plate.

10. The coaxial cage structure at the transmitting end of an ellipsometer according to claim 1, characterized in that: The first plate body is provided with a second axial through hole for the third bracket to pass through, the movable plate is provided with a coaxial mounting plate, and the end of the second bracket is fixedly connected to the coaxial mounting plate.

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