Optical element switching device

Abstract

The invention belongs to the technical field of semiconductor detection, and discloses an optical element switching device which comprises a vibration reduction support used for being installed on a preset carrier, and the vibration reduction support is provided with a vibration reduction assembly used for being installed on the preset carrier; the switching assembly is installed on the vibration reduction support, the switching assembly comprises a driving part and a seat body used for arranging one or more optical elements, the seat body is connected to the output end of the driving part and is arranged on a crossed plane of a preset light path, and the driving part is used for driving the seat body to deflect in the crossed plane; therefore, each optical element on the seat body can be cut into a preset light path. According to the optical detection equipment, the rapid switching requirement between the optical elements can be met to improve the switching efficiency, meanwhile, the influence of vibration of the driving part on the optical path is avoided, and the overall performance of the optical detection equipment can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor detection technology, and more specifically, to an optical element switching device. Background Art

[0002] To eliminate the effects of illumination, transmittance, and detector pixel sensitivity non-uniformity on overlay accuracy during EDBO (empirical DBO) measurements, a polarization module has been added to the device. This module adjusts the light source's polarization mode to different polarization modes. The diffracted light intensity signal from the marker is collected separately under each polarization mode. The ratio of the two measured intensities, known as the self-reference signal, is used to calculate the overlay error, achieving higher measurement accuracy. Since the polarization module must be constantly switched within the optical path during the measurement process, the switching speed significantly affects the device's measurement efficiency.

[0003] Existing switching devices typically use a rotating motor to drive a wheel. Specifically, a polarization module is mounted on the wheel, which is driven by a rotating motor to rotate 360 degrees, switching the polarization module within the optical path to enable measurement. The structural layout of existing switching devices only considers the switching function, but does not consider the need for rapid switching between optical components, significantly affecting the device's measurement efficiency.

[0004] Regarding the above-mentioned related technical means, there is a defect that the existing switching device causes low equipment measurement efficiency. Summary of the Invention

[0005] The embodiment of the present application provides an optical element switching device, which can meet the demand for rapid switching between optical elements and improve the measurement efficiency of the equipment.

[0006] The present application provides an optical element switching device that adopts the following technical solution:

[0007] An optical element switching device, comprising:

[0008] A vibration-damping bracket, used for being mounted on a preset carrier, wherein the vibration-damping bracket has a vibration-damping assembly for being mounted on the preset carrier;

[0009] A switching assembly is mounted on the vibration-damping bracket, comprising a driving member and a base for arranging one or more optical elements, wherein the base is connected to the output end of the driving member and is arranged along an intersection plane of a preset optical path, and the driving member is used to drive the base to perform a yaw motion within the intersection plane so that each optical element on the base can be cut into the preset optical path.

[0010] Optionally, the base has a fan-shaped layout area, and one or more mounting positions passing through the base are provided in the layout area, and the mounting positions are used to fix optical elements, which are polarizers, filters, attenuation plates, lenses or apertures.

[0011] Optionally, two of the plurality of mounting positions are used to fix a first polarizer and a second polarizer respectively, and the first polarizer and the second polarizer have different polarization directions for the light beam when they are respectively in the preset light path.

[0012] Optionally, when the area of the first polarizer and the second polarizer is smaller than the preset area, the position of the light spot entering the preset light path is the middle thereof; when the area of the first polarizer and the second polarizer is greater than or equal to the preset area, the position of the light spot entering the preset light path is the adjacent side thereof.

[0013] Optionally, the cross section of the seat body is fan-shaped, a weight-reducing hole is provided on the seat body, and a reinforcing rib is provided in the middle of the weight-reducing hole.

[0014] Optionally, the vibration damping bracket includes multiple cantilevers, one end of each of the multiple cantilevers is connected to a preset carrier through the corresponding vibration damping assembly, and the other ends of the multiple cantilevers converge from different directions to form a suspension part, which is used to connect the driving member.

[0015] Optionally, the vibration damping bracket also includes an adapter plate, the vibration damping assembly includes a first vibration damping unit and a second vibration damping unit, the cantilever is connected to the adapter plate through the first vibration damping unit, and the adapter plate is connected to the preset carrier through the second vibration damping unit, and the first vibration damping unit and the second vibration damping unit are used to cooperate to form a two-stage vibration damping structure to reduce the vibration transmission between the driving member and the preset carrier.

[0016] Optionally, an exhaust cover is further included, which covers the output end of the driving component, and the exhaust cover is provided with an exhaust hole connected to the exhaust pipe, and the exhaust hole is used to absorb pollutants in the exhaust cover.

[0017] Optionally, it further includes a lens barrel placed in the preset optical path, the lens barrel is provided with an avoidance groove for avoiding the movement trajectory of the base body, and when the base body is swung into the avoidance groove, any optical element can be cut into the optical path.

[0018] Optionally, a protective cover is provided on the outer wall of the lens barrel, and the protective cover is provided with an avoidance opening for avoiding the movement trajectory of the base body, and the protective cover is used to partially cover the avoidance groove.

[0019] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0020] The driving member arranged on the vibration-damping bracket drives the base body to perform a yaw motion in the intersection plane along the preset optical path, so that each optical element on the base body can be cut into the preset optical path, meeting the application requirements of rapid switching of optical elements and improving the optical detection efficiency of the equipment; at the same time, the setting of the vibration-damping component reduces the vibration generated by the operation of the driving member and the vibration transmission caused by acceleration and deceleration during the start and stop of the driving member, thereby minimizing the impact of vibration on the optical path and improving the overall performance of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall structure of an optical element switching device disclosed in an embodiment of the present application installed on a preset carrier;

[0022] Figure 2 A schematic structural diagram of an optical element switching device disclosed in an embodiment of the present application from another perspective;

[0023] Figure 3 This is a structural disassembly diagram of an optical element switching device disclosed in an embodiment of the present application, highlighting a vibration-damping bracket;

[0024] Figure 4 This is a disassembly diagram of an optical element switching device disclosed in an embodiment of the present application, highlighting the lens barrel and the base;

[0025] FIG5 is a schematic structural diagram of a protruding base of an optical element switching device disclosed in an embodiment of the present application, wherein: Figure 5a A schematic diagram of the seat. Figure 5b Another schematic diagram of the seat.

[0026] Description of reference numerals:

[0027] 1. Vibration-damping bracket; 11. Cantilever; 12. Adapter plate; 13. Suspension part; 2. Lens barrel; 21. Preset optical path; 22. Avoidance groove; 3. Driving part; 31. Extraction cover; 32. Extraction hole; 33. Motor mounting seat; 4. Base; 41. Mounting position; 42. Weight-reducing hole; 43. Reinforcement rib; 5. Vibration-damping assembly; 51. First vibration-damping unit; 52. Second vibration-damping unit; 6. Protective cover; 61. Avoidance. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the accompanying drawings.

[0029] An embodiment of the present application provides an optical element switching device.

[0030] See also Figure 1 and Figure 2In an embodiment of the present application, an optical element switching device includes a vibration-damping bracket 1 and a switching component. The vibration-damping bracket 1 is used to be installed on a preset carrier, and the switching component is installed on the vibration-damping bracket. The vibration-damping bracket 1 is used to reduce the vibration generated during the operation of the switching component and transmit it to the preset carrier, so as to reduce the impact of the switching component on the optical imaging of the system, and also reduce the switching action time of the switching component, thereby improving the measurement efficiency of the equipment.

[0031] In actual installation, the preset carrier can be the mounting backplane of the optical-mechanical assembly, and the preset carrier is usually arranged vertically or horizontally. The vibration-damping bracket 1 includes a vibration-damping assembly 5, a plurality of cantilevers 11, and a plurality of adapter plates 12. One end of each of the plurality of cantilevers 11 is connected to the preset carrier through the corresponding vibration-damping assembly 5, and the other ends of the plurality of cantilevers 11 converge from different directions to form a suspension portion 13. The suspension portion 13 is used to connect the switching assembly to place the switching assembly in the desired position. The adapter plate 12 is arranged in a one-to-one correspondence with the cantilever 11, and the adapter plate 12 is located between the preset carrier and the cantilever 11. The vibration-damping assembly 5 is installed on the adapter plate 12, and the corresponding vibration-damping assembly 5 is used to reduce the vibration transmission between the switching assembly and the preset carrier.

[0032] To ensure the compactness and reliability of the optical machine's overall structure, in this embodiment, the vibration-damping bracket 1 is connected to a pre-set carrier in both the X and Y directions to reduce the stress on the cantilever 11. Specifically, the cantilever 11 includes an X-direction cantilever 11 and a Y-direction cantilever 11, and the adapter plate 12 includes an X-direction adapter plate 12 and a Y-direction adapter plate 12. The X-direction cantilever 11 and the Y-direction cantilever 11 correspond to the X-direction adapter plate 12 and the Y-direction adapter plate 12, respectively. The X-direction adapter plate 12 and the Y-direction adapter plate 12 are located on two adjacent and mutually perpendicular end surfaces of the pre-set carrier.

[0033] The vibration damping assembly 5 includes a first vibration damping unit 51 and a second vibration damping unit 52. The first vibration damping unit 51 is located between the cantilever 11 and the adapter plate 12, that is, between the X-axis cantilever 11 and the X-axis adapter plate 12, and between the Y-axis cantilever 11 and the Y-axis adapter plate 12. The cantilever 11 is connected to the adapter plate 12 via the first vibration damping unit 51. The second vibration damping unit 52 is located between the adapter plate 12 and the predetermined carrier, that is, between the X-axis adapter plate 12 and the predetermined carrier, and between the Y-axis adapter plate 12 and the predetermined carrier. The adapter plate 12 is connected to the predetermined carrier via the second vibration damping unit 52. The first vibration damping unit 51 and the second vibration damping unit 52 cooperate to form a two-stage vibration damping structure to reduce vibration transmission between the switching assembly and the predetermined carrier. In this example, because the primary vibration damping structure must adopt a cantilever structure, this structural support (cantilever 11) is minimized in weight, ignoring its rigidity. The secondary vibration damping structure, in conjunction with the primary vibration damping structure, utilizes a fixed-beam structure, ensuring the structural rigidity of the secondary structure (adapter plate 12). In this embodiment, both the first and second vibration damping units 51, 52 utilize shouldered vibration damping pads made of high-damping material. The connection between the first vibration damping unit 51 and the X- and Y-axis adapter plates 12 is a simply supported beam, enhancing the installation stability between the first vibration damping unit 51 and the X- and Y-axis adapter plates 12. The first vibration reduction unit 51 and the second vibration reduction unit 52 respectively isolate the cantilever 11 and the adapter plate 12, and the adapter plate 12 and the preset carrier, absorb the impact energy generated by the acceleration and deceleration during the operation and start-stop process of the switching component, and convert the mechanical vibration energy into heat energy dissipation, thereby achieving the vibration reduction effect. The vibration reduction component 5 also reduces the vibration transmitted to other optical modules in the switching component, reduces the setting time of the overall device, and thus improves the measurement efficiency.

[0034] See also Figure 3 and Figure 4 The switching assembly includes a driver 3 and a base 4 for arranging one or more optical elements. The base 4 is connected to the output end of the driver 3 and is arranged along the intersection plane of the preset optical path. The driver 3 is used to drive the base 4 to perform a yaw motion in the intersection plane so that each optical element on the base 4 can be cut into the preset optical path. The driver 3 serves as a motion driving device to achieve the effect of each optical element on the base 4 being cut into the preset optical path. The driver 3 is a rotating motor. A low-mass, small-inertia driver 3 is preferably used as the motion driving device to reduce the impact input to the whole. The driver 3 is installed at the suspension part 13 of the vibration-damping bracket 1. In order to increase the installation stability of the driver 3, in this embodiment, the suspension part 13 is provided with a motor mounting seat 33, and the driver 3 is fixedly mounted on the motor mounting seat 33.

[0035] See also Figure 2Furthermore, in order to remove the particles generated instantly during the movement of the driving member 3 and prevent the particles generated by the driving member 3 from contaminating other optical components, an exhaust cover 31 is provided at the shaft end of the driving member 3. The exhaust cover 31 covers the output end of the driving member 3, and an exhaust hole 32 connected to the exhaust pipe is provided on the exhaust cover 31. The exhaust hole 32 is used to absorb the pollutants in the exhaust cover 31, ensuring that the polarization module fast switching device still meets the cleanliness requirements of the semiconductor equipment during high-speed operation.

[0036] See also Figure 2 and Figure 4 In this embodiment, the preset optical path is provided by the lens barrel 2, which is rigidly connected to the preset carrier through a component and is arranged horizontally. The driving member 3 is located directly above or to the side of the lens barrel 2. The lens barrel 2 is provided with a avoidance groove 22 to avoid the movement trajectory of the base body 4. When the base body 4 is swung into the avoidance groove 22, any optical element can be cut into the preset optical path, so that the optical element performs corresponding optical processing on the light beam in the preset optical path. The outer wall of the lens barrel 2 is provided with a protective cover 6. The protective cover 6 is provided with a avoidance opening 61 to avoid the movement trajectory of the base body 4. The protective cover 6 is used to partially block the avoidance groove 22. On the one hand, the protective cover 6 seals the preset optical path to prevent stray light from entering the lens barrel 2, and on the other hand, it prevents particles from falling into the lens barrel 2 during movement. The protective cover 6 is circular and is enclosed by a first mounting portion and a second mounting portion. The two ends of the first mounting portion and the second mounting portion are connected by bolts. Since the initial position of the polarizer needs to be calibrated, the protective cover 6 can be removed without removing the base body 4, facilitating structural decoupling and avoiding repeated position calibration.

[0037] See also Figure 4 As shown in Figure 5, the base 4 has a fan-shaped layout area, within which one or more mounting positions 41 extending through the base 4 are provided. The mounting positions 41 are used to secure optical elements, such as polarizers, filters, attenuators, lenses, or apertures. In this embodiment, multiple mounting positions 41 are spaced apart, and two of the multiple mounting positions 41 are used to secure a first polarizer and a second polarizer, respectively. The first polarizer and the second polarizer, when in a predetermined optical path, polarize the light beam in different directions. The first polarizer and the second polarizer are both bonded to the base 4, adjacent to each other, and their wire grid directions are perpendicular to each other. The operation of the driver 3 causes the base 4 to perform a yaw motion within the intersecting plane, so that the first and second polarizers on the base 4 are sequentially inserted into the predetermined optical path, thereby satisfying the requirement for switching between different polarization directions of the light beam. The yaw rotation of the driver 3 enables switching between the vertical phase polarizers, i.e., switching between the first and second polarizers. The rational structural layout reduces the time required to switch between the vertical phase polarizers, further improving the measurement efficiency of the device.

[0038] In some embodiments, the first polarizer and the second polarizer are made of custom small-sized polarizers, such as Figure 5a As shown, the use of customized small-sized polarizers reduces the rotation angle required by the driver 3 to switch between the first and second polarizers. By rationally arranging the polarizers, the travel distance of the two polarizers is minimized when they are in the preset optical path, thereby reducing the movement time of the base body and further improving detection efficiency. In this case, the configuration can be arranged from left to right to sequentially represent the first polarizer, the second polarizer, and the equivalent polarizer. The arrows on the polarizers indicate the direction of the wire grid, and the circle indicates the location of the optical spot when the polarizer switches to the optical path. The operation of the driver 3 causes the base body 4 to deflect by a certain angle, thereby controlling the first or second polarizer to switch to the preset optical path. The optical spot is located at the center of the customized small-sized polarizer when it switches to the optical path.

[0039] In some other embodiments, the transmittance of the customized polarizer is lower than that of the standard polarizer due to factors such as size limitations. Therefore, for a slightly larger standard polarizer, it can be configured from left to right to be the first polarizer, the second polarizer, and the equivalent polarizer, with the first polarizer and the second polarizer being standard size polarizers. Figure 5b As shown, the driving member operates, driving the base 4 to deflect by a corresponding angle, controlling the first polarizer or the second polarizer to switch to a preset optical path. When the standard-sized polarizer switches to the optical path, the light spot position is located on the adjacent side of the standard-sized polarizer. The intersection of the line stacks of the two polarizers and the line connecting the vertical line stacks is controlled to be located above the center of the rotation axis of the base 4, so as to reduce the impact of the increase in the required rotation angle caused by the large size of the polarizer.

[0040] It should be noted that the equivalent sheet provided on the base 4 can be considered as an optical element with other functions, such as a lens, a filter, etc., or can even be a lensless structure. When the equivalent sheet is configured as a lensless structure, the light beam can pass directly through the structure when it cuts into the light path.

[0041] To achieve rapid switching of the vertical phase polarizer, the base 4 is designed to be as lightweight as possible. In this embodiment, the base 4 has a fan-shaped cross-section and is provided with a weight-reducing hole 42, which further reduces the impact energy on the entire device when the base 4 deflects. A reinforcing rib 43 is located in the middle of the weight-reducing hole 42. The length of the rib 43 aligns with the deflection direction of the base 4. At the expense of a small amount of weight, the rib 43 increases the rigidity of the base 4 in the deflection direction, reducing the resonant energy at the source of the vibration.

[0042] The above are all preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. The same components are represented by the same figure marks, and any equivalent changes made based on the structure, shape, and principle of the present application should be covered within the scope of protection of the present application.

Claims

1. An optical element switching device, characterized in that: include: A vibration-damping bracket (1) for being mounted on a predetermined carrier, wherein the vibration-damping bracket (1) has a vibration-damping assembly (5) for being mounted on the predetermined carrier; A switching assembly is mounted on the vibration-damping bracket (1), comprising a driving member (3) and a base (4) for arranging one or more optical elements, wherein the base (4) is connected to the output end of the driving member (3) and is arranged on a cross plane along a preset optical path, and the driving member (3) is used to drive the base (4) to perform a yaw motion within the cross plane, so that each optical element on the base (4) can be cut into the preset optical path.

2. The optical element switching device according to claim 1, wherein: The base (4) has a fan-shaped layout area, and one or more mounting positions (41) passing through the base (4) are provided in the layout area. The mounting positions (41) are used to fix optical elements, and the optical elements are polarizers, filters, attenuation plates, lenses or diaphragms.

3. The optical element switching device according to claim 2, wherein: Two of the plurality of mounting positions (41) are used to fix a first polarizer and a second polarizer respectively, and the polarization directions of the light beam are different when the first polarizer and the second polarizer are respectively in the preset light path.

4. The optical element switching device according to claim 3, wherein: When the area of the first polarizer and the second polarizer is smaller than the preset area, the position of the light spot entering the preset light path is the middle thereof; when the area of the first polarizer and the second polarizer is greater than or equal to the preset area, the position of the light spot entering the preset light path is the adjacent side thereof.

5. The optical element switching device according to claim 2, wherein: The cross section of the seat body (4) is fan-shaped. A weight-reducing hole (44) is provided on the seat body (4), and a reinforcing rib (45) is provided in the middle of the weight-reducing hole (44).

6. The optical element switching device according to claim 1, characterized in that: The vibration-damping bracket (1) comprises a plurality of cantilevers (11), one end of each of the cantilevers (11) is connected to the preset carrier via the corresponding vibration-damping assembly (5), and the other ends of the cantilevers (11) converge from different directions to form a suspension portion (13), and the suspension portion (13) is used to connect to the driving member (3).

7. The optical element switching device according to claim 6, characterized in that: The vibration-damping bracket (1) further includes an adapter plate (12); the vibration-damping assembly (5) includes a first vibration-damping unit (51) and a second vibration-damping unit (52); the cantilever (11) is connected to the adapter plate (12) via the first vibration-damping unit (51); the adapter plate (12) is connected to the preset carrier via the second vibration-damping unit (52); the first vibration-damping unit (51) and the second vibration-damping unit (52) are used to cooperate to form a two-stage vibration-damping structure to reduce vibration transmission between the driving member (3) and the preset carrier.

8. The optical element switching device according to claim 1, wherein: The invention also comprises an exhaust cover (31), the exhaust cover (31) covers the output end of the driving member (3), and the exhaust cover (31) is provided with an exhaust hole (32) connected to an exhaust pipe, and the exhaust hole (32) is used to absorb pollutants in the exhaust cover (31).

9. The optical element switching device according to claim 1, wherein: The invention also includes a lens barrel (2) placed in the preset optical path, wherein the lens barrel (2) is provided with an avoidance groove (22) for avoiding the movement trajectory of the seat body (4), and when the seat body (4) is swung into the avoidance groove (22), any of the optical elements can be cut into the preset optical path.

10. The optical element switching device according to claim 9, characterized in that: The outer wall of the lens barrel (2) is provided with a protective cover (6), the protective cover (6) is provided with an escape opening (61) for avoiding the movement trajectory of the seat body (4), and the protective cover (6) is used to partially cover the escape groove (22).

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