Prism deviation adjusting device and prism deviation monitoring system
By using a prism biasing device in the elliptical polarization path, adjusting the alignment degree between the prism and the optical path, the problem that the prism alignment accuracy affects the measurement results is solved, and the effect of improving measurement accuracy and stability is achieved.
Patent Information
- Application Number
- CN202422026499.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-08-20
AI Technical Summary
In an elliptical polarization path, the alignment accuracy of the prism has a direct impact on the disturbance of the optical path, resulting in inaccuracy and instability of the measurement results. The prior art requires reinstalling the prism to adjust the alignment degree, increasing the complexity and possible offsets.
A prism biasing device is provided, including a rotating hollow motor, a prism mounting mechanism, a prism, a screw member and a top wire member. By adjusting the top pulling effect of the screw member and the top wire member, the perpendicularity of the flange ring end surface of the prism mounting mechanism and the rotation axis of the rotating hollow motor is adjusted to solve the problem of alignment of the prism in the optical path.
By adjusting the alignment degree of the prism, the optical path disturbance is reduced, the light reception quality is improved, the accuracy and stability of the measurement results are enhanced, and the inconsistency of measurement results during long-term operation is avoided.
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Figure CN222896307U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a prism deviation adjustment device and a prism deviation monitoring system. Background Art
[0002] Ellipsometry is a non-destructive optical characterization technology widely used in the field of semiconductor wafers to measure physical properties such as film thickness, refractive index, and roughness of wafer surfaces and films. This technology is based on the reflection and refraction characteristics of light waves on the surface of the medium, and obtains material information by analyzing the changes in the polarization state of the incident light and the reflected light.
[0003] Although ellipsometry has significant advantages, there are still some technical challenges in practical applications. Among them, the alignment accuracy in the optical path is a key factor affecting the accuracy of the measurement results. In the ellipsometry optical path, a device is usually used to install a polarizing prism in a rotating hollow motor. Since the prism rotates at high speed with the motor, its alignment in the optical path has a direct impact on the disturbance of the optical path, which in turn affects the quality of light reception and ultimately affects the measurement accuracy and stability.
[0004] In the prior art, it is generally necessary to reinstall the prism to adjust the alignment, which increases the difficulty and complexity of adjusting the alignment of the pipeline, and the reinstalled prism may produce a larger offset. Utility Model Content
[0005] The purpose of the embodiments of the present application is to provide a prism deflection adjustment device and a prism offset monitoring system, wherein the prism deflection adjustment device can adjust the alignment degree between the prism and the optical path to improve the quality of light reception and improve measurement accuracy and measurement stability.
[0006] In the first aspect, a prism deflection adjustment device is provided, comprising a rotating hollow motor, a prism mounting mechanism, a prism, a screw and a top screw. The rotating hollow motor has a hollow channel and an annular mounting end face arranged at one end of the hollow channel, and at least three threaded holes distributed circumferentially are arranged on the annular mounting end face. The prism mounting mechanism comprises a flange ring, an extension and a prism mounting channel, the extension is connected to one side of the flange ring, and the prism mounting channel runs through the flange ring and the extension; the flange ring is provided with mounting holes and at least three top screw holes distributed circumferentially with the same number as the threaded holes; the extension of the prism mounting mechanism is inserted into the hollow channel of the rotating hollow motor, the flange ring is fitted on the annular mounting end face, and the mounting holes correspond to the threaded holes one by one. The prism is installed in the prism mounting channel. In each pair of mounting holes and threaded holes, the screw passes through the mounting hole and is threadedly connected to the threaded hole to fasten the flange ring to the annular mounting end face. A top screw is installed in each top screw hole, and each top screw is pressed against the annular mounting end face.
[0007] In an implementable solution, the threaded holes on the annular mounting end surface are evenly distributed around the circumference; the mounting holes on the flange ring are evenly distributed around the circumference; and the top screw holes on the flange ring are evenly distributed around the circumference.
[0008] In an implementable solution, the number of the mounting holes and the top screw holes is the same, and the mounting holes and the top screw holes are distributed at intervals around the circumference of the flange ring.
[0009] In an implementable solution, the mounting hole and the top screw hole exist in pairs, and in the paired mounting hole and the top screw hole, the top screw hole is arranged adjacent to the mounting hole.
[0010] In an implementable solution, the position where the top screw piece hits the annular mounting end surface is called a top contact position, and multiple top screw pieces correspond to multiple top contact positions;
[0011] Inverted tapered grooves are provided at the annular mounting end surfaces corresponding to at least two of the top contact positions, and the annular mounting end surfaces corresponding to the other top contact positions are provided as planes or as top contact grooves extending in a predetermined direction.
[0012] In one feasible solution, the prism has a quadrangular prism shape.
[0013] In an implementable solution, the shape of the prism mounting channel is consistent with the appearance of the prism, and buffer channels extending along the prism mounting channel are provided at the four corners of the prism mounting channel.
[0014] In an implementable solution, the extension portion of the prism mounting mechanism includes four side wall structures surrounding the prism, and the four side wall structures are separated from each other.
[0015] In a second aspect, the present application provides a prism offset monitoring system, including the aforementioned prism deflection adjustment device, and also including an interferometer and a control device. The interferometer is arranged opposite to the prism mounting mechanism, and the interferometer is used to emit parallel light to the prism and receive reflected light, and display light and dark interference fringes. The control device is electrically connected to the rotating hollow motor of the prism deflection adjustment device, and the control device is used to control the rotation of the rotating hollow motor.
[0016] Compared with the prior art, the beneficial effects of this application include at least:
[0017] When the prism deviation adjustment device of the present application is used, the verticality of the prism end face and the rotating shaft of the rotating hollow motor can be obtained through a collimator, interferometer and other equipment to determine the deviation of the prism, and then all or part of the screws and top screws can be adjusted. Through the pulling action of the screws and top screws, the verticality of the end face of the flange ring of the prism mounting mechanism and the rotating shaft of the rotating hollow motor is adjusted, that is, the verticality of the prism end face and the rotating shaft of the rotating hollow motor is adjusted, which solves the alignment problem of the prism in the optical path, can reduce the optical path disturbance caused by the rotation of the prism, reduce the error caused by the optical path disturbance, ensure the quality of light reception, thereby improving the accuracy and repeatability of the measurement results, enhancing the stability of the measurement system, and ensuring the consistency of the measurement results during long-term operation.
[0018] Furthermore, the entire adjustment process only requires the use of screws and top screws to pull together to make adjustments within a small range, without the need to dismantle the prism and reinstall it, so the adjustment method is relatively easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 is a three-dimensional structural diagram of a prism deflection adjustment device according to an embodiment of the present application;
[0021] Figure 2 for Figure 1 Exploded structure diagram of the middle prism deflection adjustment device;
[0022] Figure 3 for Figure 1 A front view of the middle prism deflection adjustment device;
[0023] Figure 4 For along Figure 3 Sectional view of AA in the middle;
[0024] Figure 5 For along Figure 3 Cross-sectional view of the middle BB;
[0025] Figure 6 is a three-dimensional structural diagram of a prism mounting mechanism of a prism deflection adjustment device according to an embodiment of the present application;
[0026] Figure 7 A partial structural diagram of the mounting end surface of a hollow motor of a prism deflection adjustment device according to an embodiment of the present application;
[0027] Figure 8 is a structural diagram of a prism deviation monitoring system according to an embodiment of the present application;
[0028] Fig. 9 Schematic diagram of the prism being misaligned with the incident light path;
[0029] Fig.10 Schematic diagram of the prism being aligned with the incident light path.
[0030] In the figure: 1. rotating hollow motor; 11. hollow channel; 12. annular mounting end face; 121. threaded hole; 122. inverted conical groove; 123. top contact groove; 2. prism mounting mechanism; 21. flange ring; 211. mounting hole; 212. top screw hole; 22. extension; 23. prism mounting channel; 231. buffer channel; 3. prism; 4. screw; 5. top screw; 100. interferometer; 200. control device. DETAILED DESCRIPTION
[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0033] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, an embodiment of the present application provides a prism deviation adjustment device, including a rotating hollow motor 1, a prism mounting mechanism 2, a prism 3, a screw member 4 and a top screw member 5.
[0034] Among them, Figure 2 As shown, the rotating hollow motor 1 has a hollow channel 11 and an annular mounting end surface 12 arranged at one end of the hollow channel 11 , and at least three threaded holes 121 distributed circumferentially are arranged on the annular mounting end surface 12 .
[0035] like Figure 2 and Figure 4As shown, the prism mounting mechanism 2 includes a flange ring 21, an extension 22 and a prism mounting channel 23, the extension 22 is connected to one side of the flange ring 21, and the prism mounting channel 23 runs through the flange ring 21 and the extension 22; the flange ring 21 is provided with mounting holes 211 having the same number as the threaded holes 121 and at least three top screw holes 212 distributed circumferentially; the extension 22 of the prism mounting mechanism 2 is inserted into the hollow channel 11 of the rotating hollow motor 1, the flange ring 21 is attached to the annular mounting end face 12, and the mounting holes 211 correspond to the threaded holes 121 one by one. Among them, the prism 3 is generally mounted in the prism mounting channel 23 by bonding with some adhesive.
[0036] like Figure 2 and Figure 5 As shown, in each pair of mounting holes 211 and threaded holes 121, screws 4 pass through mounting holes 211 and are threadedly connected with threaded holes 121 to fasten flange ring 21 to annular mounting end surface 12. A top screw 5 is installed in each top screw hole 212, and each top screw 5 is pressed against the annular mounting end surface 12.
[0037] When the prism deviation adjustment device of the embodiment of the present application is used, the verticality of the end face of the prism 3 and the rotating axis of the rotating hollow motor 1 can be obtained through a collimator, an interferometer and other equipment to determine the deviation of the prism 3, and then all or part of the screws 4 and the top screws 5 are adjusted. Through the pulling action of the screws 4 and the top screws 5, the verticality of the end face of the flange ring 21 of the prism mounting mechanism 2 and the rotating axis of the rotating hollow motor 1 is adjusted, that is, the verticality of the end face of the prism 3 and the rotating axis of the rotating hollow motor 1 is adjusted, which solves the alignment problem of the prism 3 in the optical path, can reduce the optical path disturbance caused by the rotation of the prism 3, reduce the error caused by the optical path disturbance, ensure the quality of light reception, thereby improving the accuracy and repeatability of the measurement results, enhancing the stability of the measurement system, and ensuring the consistency of the measurement results during long-term operation.
[0038] Furthermore, the entire adjustment process only requires the use of the screw member 4 and the top screw member 5 to adjust within a small range by pulling and pushing, and there is no need to dismantle the prism and reinstall it, so the adjustment method is relatively easy to operate.
[0039] like Fig. 9 As shown, if the vertical accuracy between the end face of the prism 3 and the optical path is not enough (the degree of collimation does not meet the requirements), that is, the prism 3 is not aligned with the optical path. During the rotation of the rotating hollow motor 1, the offset of the output optical axis meets the following formula:
[0040] D=L*sin(a-arcsin(sin(a) / N));
[0041] Where D is the optical axis offset;
[0042] L is the prism length;
[0043] a is the verticality, i.e. the angle of incidence, and the ideal value is 0;
[0044] N is the refractive index of the prism.
[0045] When a=0, D=0, that is, there is no offset.
[0046] When the alignment of the prism in the optical path deviates greatly, the a value moves away from the minimum value 0, which in turn causes a larger D value, thus affecting the measurement stability.
[0047] The prism deviation adjustment device of the present application adjusts the verticality of the end face of the prism 3 and the rotating axis of the rotating hollow motor 1 through the pulling action of the screw member 4 and the top screw member 5, that is, the value of a is adjusted to be as close to 0 as possible, so that a is within an acceptable error range, so that the optical axis offset D is as close to 0 as possible, and the optical axis offset D is within an acceptable offset range, thereby improving the alignment of the prism 3 in the optical path.
[0048] In this embodiment, if Figure 7 As shown, the threaded holes 121 on the annular mounting end surface 12 are evenly distributed around the circumference. Figure 6 As shown, the mounting holes 211 on the flange ring 21 are evenly distributed around the circumference, and the top screw holes 212 on the flange ring 21 are evenly distributed around the circumference.
[0049] In this embodiment, if Figure 6 As shown, the number of the mounting holes 211 and the top screw holes 212 can be the same, and the mounting holes 211 and the top screw holes 212 are spaced apart around the circumference of the flange ring 21 so that the top pulling force is applied to the flange ring 21 in a balanced manner.
[0050] In this embodiment, if Figure 6 As shown, the mounting hole 211 and the top screw hole 212 may exist in pairs. In the paired mounting hole 211 and the top screw hole 212 , the top screw hole 212 is disposed adjacent to the mounting hole 211 to further balance the top pulling force applied to the flange ring 21 .
[0051] In this embodiment, if Figure 7 As shown, the position where the top screw 5 is pressed against the annular mounting end surface 12 is called the top contact position, and multiple top screws 5 correspond to multiple top contact positions. An inverted tapered groove 122 can be provided at the annular mounting end surface 12 corresponding to at least two top contact positions to achieve the top holding and positioning of the top screw 5, and the annular mounting end surface 12 corresponding to other top contact positions is set as a plane or set as a top contact groove 123 extending in a predetermined direction, so that the top screw 5 can produce a certain displacement at the top contact position, thereby releasing the unexpected stress.
[0052] In this embodiment, if Figure 1As shown, the prism 3 has a quadrangular prism shape, for example, the cross section of the prism 3 may be a square or a rectangle. Preferably, the prism 3 has a regular quadrangular prism shape.
[0053] In this embodiment, if Figure 6 As shown, the shape of the prism installation channel 23 is consistent with the appearance of the prism 3, and the four corners of the prism installation channel 23 are provided with buffer channels 231 extending along the prism installation channel 23, which is convenient for installing the prism 3 on the one hand and filling the adhesive on the other hand.
[0054] In this embodiment, if Figure 6 As shown, the extension portion 22 of the prism mounting mechanism 2 includes four side wall structures surrounding the prism 3, and the four side wall structures are separated from each other.
[0055] like Figure 8 As shown, an embodiment of the present application also provides a prism offset monitoring system, including the prism offset adjustment device in the aforementioned scheme, and also including an interferometer 100 and a control device 200.
[0056] The interferometer 100 is arranged opposite to the prism mounting mechanism 2, and the interferometer 100 is used to emit parallel light to the prism 3 and receive reflected light, and display light and dark interference fringes. The control device 200 is electrically connected to the rotating hollow motor 1 of the prism deflection adjustment device, and the control device 200 is used to control the rotation of the rotating hollow motor 1.
[0057] The prism offset monitoring system of the present application monitors prism offset, which can actually be understood as monitoring the incident angle a.
[0058]
[0059] Right now:
[0060]
[0061] Where n is the number of interference fringes;
[0062] M is the side length of the prism end face. The prism end face is generally square. If the prism end face is rectangular, it refers to the short side.
[0063] a is the perpendicularity between the incident parallel light and the end face of the prism (the ideal perpendicularity is 0), which is generally a minimum value;
[0064] λ is the wavelength of the interferometer.
[0065] It can be seen that the value of the incident angle a can be obtained by the number of interference fringes on the interferometer 100, and the degree of deviation of the prism 3 can be determined to facilitate adjustment.
[0066] The embodiment of the present application also provides a method for adjusting the prism deviation based on the prism deviation monitoring system. Before the adjustment, installation is first performed, including:
[0067] Install and adjust the angle of the rotating hollow motor 1 so that the annular mounting end surface 12 of the rotating hollow motor 1 is aligned with the interferometer 100;
[0068] The prism 3 is fixed to the prism mounting mechanism 2 and mounted to the rotating hollow motor 1 .
[0069] After installation, the following methods are available for adjustment:
[0070] S1, the control device 200 controls the rotating hollow motor 1 to drive the prism 3 to rotate; preferably, the prism 3 rotates at a uniform speed;
[0071] S2, the interferometer 100 emits parallel light to the prism 3 and receives the reflected light reflected by the prism 3;
[0072] S3, observe the number of interference fringes on the interferometer 100. If the number of interference fringes is consistent with the number of interference fringes during emission, it means that the rotation axis of the rotating hollow motor 1 is substantially parallel to the incident parallel light, that is, the rotation axis of the rotating hollow motor 1 is substantially perpendicular to the end face of the prism 3; if the number of interference fringes is inconsistent with the number of interference fringes during emission, it means that the rotation axis of the rotating hollow motor 1 is not parallel to the incident parallel light, that is, the verticality of the rotation axis of the rotating hollow motor 1 and the end face of the prism 3 intersects, resulting in the reflected light forming new interference fringes on the interferometer 100, and thus the prism mounting mechanism 2 needs to be adjusted;
[0073] S4, stop the rotating hollow motor 1, for example, keep the rotating hollow motor 1 Figure 8 In the state shown, the tilt direction of the end face of the prism 3 can be known according to the imaging on the interferometer 100. At this time, the top pull of the adjustment screw 4 and the top wire 5 is coordinated to reduce the number of interference fringes, preferably making the number of interference fringes consistent with the number of incident parallel light fringes;
[0074] S5, repeating steps S1-S5, when the number of interference fringes reaches a predetermined index, the adjustment ends; when the number of fringes still cannot meet the requirement, further repeating steps S1-S5.
[0075] If the predetermined index is still not reached after repeating steps S1-S5 for many times, it is possible to check whether the rotating shaft of the rotating hollow motor 1 is stable. If it is unstable, there may be a problem with the rotating hollow motor 1, and the rotating hollow motor 1 needs to be replaced and the adjustment process of steps S1-S5 needs to be repeated.
[0076] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A prism deflection adjustment device, characterized in that: include: A rotating hollow motor (1) comprises a hollow channel (11) and an annular mounting end surface (12) arranged at one end of the hollow channel (11), wherein at least three threaded holes (121) distributed circumferentially are arranged on the annular mounting end surface (12); A prism mounting mechanism (2) comprises a flange ring (21), an extension portion (22) and a prism mounting channel (23), wherein the extension portion (22) is connected to one side of the flange ring (21), and the prism mounting channel (23) passes through the flange ring (21) and the extension portion (22); the flange ring (21) is provided with mounting holes (211) having the same number as the threaded holes (121) and at least three top screw holes (212) distributed circumferentially; the extension portion (22) of the prism mounting mechanism (2) is inserted into the hollow channel (11) of the rotating hollow motor (1), the flange ring (21) is attached to the annular mounting end surface (12), and the mounting holes (211) correspond one-to-one with the threaded holes (121); A prism (3) installed in the prism installation channel (23); a screw member (4), in each pair of the mounting hole (211) and the threaded hole (121), the screw member (4) passing through the mounting hole (211) and being threadedly connected with the threaded hole (121) so as to fasten the flange ring (21) and the annular mounting end surface (12) together; A top screw member (5) is installed in each of the top screw holes (212), and each of the top screw members (5) is pressed against the annular mounting end surface (12).
2. The prism deflection adjustment device according to claim 1, characterized in that: The threaded holes (121) on the annular mounting end surface (12) are evenly distributed around the circumference; The mounting holes (211) on the flange ring (21) are evenly distributed around the circumference, and the top screw holes (212) on the flange ring (21) are evenly distributed around the circumference.
3. The prism deflection adjustment device according to claim 2, characterized in that: The number of the mounting holes (211) and the number of the top screw holes (212) are the same, and the mounting holes (211) and the top screw holes (212) are distributed at intervals around the circumference of the flange ring (21).
4. The prism deflection adjustment device according to claim 2, characterized in that: The mounting hole (211) and the top screw hole (212) exist in pairs, and in the pair of the mounting hole (211) and the top screw hole (212), the top screw hole (212) is arranged adjacent to the mounting hole (211).
5. The prism deflection adjustment device according to claim 1, characterized in that: The position where the top screw member (5) presses against the annular mounting end surface (12) is called a top contact position, and a plurality of the top screw members (5) correspond to a plurality of the top contact positions; An inverted tapered groove (122) is provided at the annular mounting end surface (12) corresponding to at least two of the top contact positions, and the annular mounting end surface (12) corresponding to the other top contact positions is provided as a plane or as a top contact groove (123) extending in a predetermined direction.
6. The prism deflection adjustment device according to any one of claims 1 to 5, characterized in that: The prism (3) has a quadrangular prism shape.
7. The prism deflection adjustment device according to claim 6, characterized in that: The shape of the prism installation channel (23) is consistent with the appearance of the prism (3), and buffer channels (231) extending along the prism installation channel (23) are provided at the four corners of the prism installation channel (23).
8. The prism deflection adjustment device according to claim 6, characterized in that: The extension portion (22) of the prism mounting mechanism (2) comprises four side wall structures surrounding the prism (3), and the four side wall structures are separated from each other.
9. A prism deviation monitoring system, characterized in that: The prism deflection adjustment device comprises the prism deflection adjustment device as claimed in any one of claims 1 to 8, and further comprises an interferometer (100) and a control device (200): The interferometer (100) is arranged opposite to the prism mounting mechanism (2), and the interferometer (100) is used to emit parallel light to the prism (3) and receive reflected light, and display bright and dark interference fringes; The control device (200) is electrically connected to the rotating hollow motor (1) of the prism deflection adjustment device, and the control device (200) is used to control the rotation of the rotating hollow motor (1).