Movable lens adjustment mechanism and photolithography equipment

Abstract

The application provides a movable lens adjusting mechanism and a lithographic apparatus, comprising: a lens group unit and a plurality of position adjusting units; wherein the lens group unit comprises: a lens seat, a lens barrel and a centering spring, the lens seat is used for fixing a lens, and the lens seat is flexibly connected with the lens barrel through the centering spring; a plurality of the position adjusting units are arranged along the circumference of the lens barrel, the position adjusting unit comprises: a driving motor and a transmission assembly, the transmission assembly comprises: a flexible connecting rod and a flexible transmission block with a parallelogram flexible hinge, the driving motor is used for providing a thrust force along the radial direction of the lens barrel to make the flexible connecting rod produce axial and vertical displacement, and the flexible transmission block is pushed to make the output end of the flexible transmission block drive the lens seat to produce displacement along the optical axis direction.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a movable lens adjustment mechanism and photolithography equipment. Background Art

[0002] In lithography projection exposure objective lenses, manufacturing and assembly errors, as well as environmental variations such as temperature, humidity, and pressure, affect image quality (optical aberrations, distortion, and field curvature). Therefore, a movable lens is required for precise positioning and vertical position adjustment in three degrees of freedom (RX / RY / DZ) to offset or compensate for optical errors. Current movable lens adjustment mechanisms suffer from a large vertical footprint, limited travel, low adjustment accuracy, low vertical first-order modal response, slow motion response, poor stability, and unreliable performance due to nonlinearities such as sliding friction.

[0003] The patent, with publication number CN101609193B and titled "A Movable Optical Element Adjustment and Positioning Device," uses a perturbation bearing as a rotation fulcrum, a rigid lever based on the lever principle to achieve one-stage transmission reduction, and a drive motor for vertical drive, achieving high-precision DZ / RX / RY three-degree-of-freedom position adjustment of the lens with a small stroke. However, it has the following problems: (1) It uses a perturbation bearing as a rotating fulcrum and a rigid lever transmission, and its non-functional direction stiffness is too large (radial and tangential). During the actual assembly movement, due to assembly errors and tilt adjustment errors, it will cause over-constraint, resulting in assembly stress concentration, leading to problems such as movement jamming or poor movement; (2) Since the spring sheet is used to provide rebound force to achieve movement reset, it cannot withstand high-frequency movement, and the overall stiffness of the mechanism depends on the stiffness of the spring sheet. Therefore, the overall stiffness of the structure is small, the modal is low, and the speed and stability of the structural movement response are poor; (3) The motor is arranged vertically, which makes installation inconvenient. The mechanism occupies a large axial space and is not suitable for objectives with high axial size constraints; (4) The rigid lever and the movable mirror group are provided with point contact through the ball head plunger. Transmission force, the driving motor driving rod and the rigid lever are also in point contact. Since the rigid lever movement is an approximately linear vertical movement, it will produce tangential and other parasitic movements, resulting in sliding friction between the ball head plunger point and the contact surface of the movable mirror group, and the contact surface between the dynamic motor driving rod and the rigid lever. Therefore, the effective driving force is reduced, nonlinear errors are introduced, which will increase the control difficulty, reduce the transmission efficiency, and affect the control accuracy; (5) The driving motor driving rod and the rigid lever, and the rigid lever and the movable mirror group are not fixed, so the reverse movement will cause a motion gap due to insufficient rebound tracking ability. The overall Z-direction stiffness is low, the modal is low, and it is easy to cause vibration, affecting the rapidity and stability of the structural motion response. It is not suitable for movable lenses with high-sensitivity motion performance requirements; (6) The friction between parts will cause particle contamination problems.

[0004] Publication number CN106547065B, titled "A Movable Lens Adjustment Device," and publication number CN108983381A, titled "A Movable Lens Adjustment Mechanism," both use similar flexible hinge mechanisms (four-link / four-link + lever amplification) for transmission to achieve high-precision DZ / RX / RY three-degree-of-freedom position adjustment of the lens with small stroke. However, it has the following problems: (1) The motor is arranged vertically, which makes installation inconvenient and the mechanism occupies a large axial space, which is not suitable for movable mirror groups with high axial size constraints; (2) The centering structure of the mirror seat is not involved, resulting in low radial and tangential stiffness of the mirror group, which is prone to large radial and tangential motion crosstalk (DX / DY / RZ); (3) The driving motor driving rod is in point contact with the flexible transmission mechanism and is not fixed, so in vertical drive, sliding friction will occur on the contact surface, reducing the effective driving force, introducing nonlinear errors, increasing the difficulty of control, reducing transmission efficiency, and affecting control accuracy; (4) The driving motor driving rod is not fixed to the flexible transmission mechanism, resulting in the vertical stiffness of the mirror group depending on the stiffness of the flexible transmission mechanism and the preload spring, resulting in low overall Z-direction stiffness and low modal, which is prone to vibration, affecting the rapidity and stability of the structural motion response, and is not suitable for movable lenses with high-sensitivity motion performance requirements.

[0005] The patent, with publication number CN208432848U and titled "Movable Optical Element Adjustment and Positioning Device," uses a motor / screw to horizontally drive a deformable element (polygonal flexible hinge) for vertical transmission, achieving high-precision DZ / RX / RY three-degree-of-freedom position adjustment of the lens with a small stroke. However, it has the following problems: (1) The motor / screw is built into the lens barrel and is screwed or fixed to both ends of the deformable element. As a result, once the movable lens group is integrated into the objective lens, the motor cannot be replaced, resulting in poor repair and maintenance. (2) The deformable element has no lever transmission displacement reduction, making it impossible to achieve large displacement and high-precision movement at the same time. (3) The motor is built into the lens barrel, causing the heat source to be close to the deformable element and the lens, resulting in poor heat dissipation. The deformable element, which is sensitive to temperature changes, will undergo thermal deformation, affecting the transmission accuracy of the mechanism. At the same time, the temperature gradient change inside the objective lens will increase, affecting the imaging quality of the objective lens. Summary of the Invention

[0006] An object of the present invention is to provide a movable lens adjustment mechanism and a photolithography device to solve one or more problems in the prior art.

[0007] In order to solve the above technical problems, the present invention provides a movable lens adjustment mechanism, comprising: a lens group unit and a plurality of position adjustment units; wherein,

[0008] The lens assembly unit comprises: a lens seat, a lens barrel and a centering spring, wherein the lens seat is used to fix the lens and is flexibly connected to the lens barrel through the centering spring;

[0009] Multiple position adjustment units are arranged along the circumference of the lens barrel, and the position adjustment units include: a drive motor and a transmission assembly, and the transmission assembly includes: a flexible connecting rod and a flexible transmission block with a parallelogram flexible hinge. The drive motor is used to provide a radial thrust along the lens barrel to cause the flexible connecting rod to produce axial and vertical displacement, and push the flexible transmission block so that the output end of the flexible transmission block drives the lens holder to produce displacement along the optical axis.

[0010] Optionally, in the movable lens adjustment mechanism, the position adjustment unit also includes: a magnet fixed to the flexible transmission block; one end of the flexible connecting rod is connected to the working end of the drive motor, and the other end of the flexible connecting rod is fixedly connected to the magnet gap through a magnetic preload force.

[0011] Optionally, in the movable lens adjustment mechanism, the position adjustment unit further includes a removal component, the removal component including a baffle, one end of the baffle being fixed to the flexible transmission block, and the other end rotating around the axis of the flexible connecting rod, and when rotating to the gap between the flexible connecting rod and the magnet, the fixed connection between the flexible connecting rod and the magnet is released.

[0012] Optionally, in the movable lens adjustment mechanism, the disassembly component also includes a limit member, which is fixed to the flexible transmission block and is used to limit the rotation angle of the baffle. When the baffle rotates to contact the limit member, the baffle covers the end face of the magnet close to the flexible connecting rod.

[0013] Optionally, in the movable lens adjustment mechanism, the output end of the flexible connecting rod has a plurality of step surfaces arranged along the circumferential direction, and the plurality of step surfaces are in point contact with the flexible transmission block. The radial component force generated by the plurality of step surfaces relative to the lever input surface of the flexible transmission block is smaller than the maximum static friction force between the flexible connecting rod and the flexible transmission block.

[0014] Optionally, in the movable lens adjustment mechanism, the flexible connecting rod has two horizontal right-angle notch hinges and two vertical right-angle notch hinges. Under the drive of the driving motor, the flexible connecting rod generates axial displacement and radial displacement through the horizontal right-angle notch hinges, and generates displacement along the optical axis through the vertical right-angle notch hinges.

[0015] Optionally, in the movable lens adjustment mechanism, the position adjustment unit also includes an adjustment gasket, the flexible transmission block is fixed to the inner side of the lens barrel, and the output end of the flexible transmission block is connected to the lens seat along the optical axis through the adjustment gasket, and the adjustment gasket is used to adjust the initial height and inclination of the lens by changing the thickness.

[0016] Optionally, in the movable lens adjustment mechanism, the driving motor is fixed to the outside of the lens barrel, the flexible connecting rod is arranged along the radial direction of the lens barrel, and the flexible driving block is fixed to the inside of the lens barrel.

[0017] Optionally, in the movable lens adjustment mechanism, the position adjustment unit further includes a sleeve, and the output shaft of the drive motor is threadedly connected to the flexible connecting rod after passing through the sleeve, and the output shaft of the drive motor and the sleeve, as well as the sleeve and the lens barrel are sealed by sealing rings.

[0018] Optionally, in the movable lens adjustment mechanism, the movable lens adjustment mechanism also includes a plurality of position sensors, which are arranged along the circumference of the lens barrel and on the inner side of the lens barrel. The plurality of position sensors are used to realize the measurement of the three-degree-of-freedom relative motion position of the lens by detecting the relative position between the lens barrel and the bottom of the lens seat.

[0019] Optionally, in the movable lens adjustment mechanism, the movable lens adjustment mechanism further includes a plurality of pre-tightening support units sequentially arranged along the circumference of the lens barrel, and the plurality of pre-tightening support units are fixed to the lens barrel for performing gravity balancing and initial support on the lens seat.

[0020] Optionally, in the movable lens adjustment mechanism, the pre-tensioning support unit includes a pre-tensioning spring, a spring seat and an adapter plate, the pre-tensioning spring is arranged in the spring seat, and one end of the pre-tensioning spring is fixed to the inner side of the lens barrel through the adapter plate, and the other end is connected to the lens seat.

[0021] The present invention also provides a photolithography device, comprising: the movable lens adjustment mechanism as described above.

[0022] In summary, the movable lens adjustment mechanism and lithography equipment provided by the present invention include: a lens group unit and multiple position adjustment units; wherein the lens group unit includes: a lens seat, a lens barrel and a centering spring, the lens seat is used to fix the lens and is flexibly connected to the lens barrel through the centering spring; multiple position adjustment units are arranged along the circumference of the lens barrel, and the position adjustment unit includes: a drive motor and a transmission assembly, the transmission assembly includes: a flexible connecting rod and a flexible transmission block with a parallelogram flexible hinge, the drive motor is used to provide a radial thrust along the lens barrel to cause the flexible connecting rod to produce axial and vertical displacement, and push the flexible transmission block to rotate with the parallelogram flexible hinge as a rotation fulcrum to produce axial and vertical displacement, thereby causing the output end of the flexible transmission block to drive the lens seat to produce displacement along the optical axis. Compared with the prior art, it has the following beneficial effects:

[0023] (1) A flexible connecting rod + lever + parallelogram flexible hinge type transmission mechanism is used to realize radial drive input and vertical transmission output, thereby improving the linear proportional motion scaling ratio and achieving large stroke and high precision motion;

[0024] (2) Furthermore, a magnet pre-tightening method is used to realize the kinematic connection between the motor drive rod and the transmission block, eliminating the introduction of nonlinear characteristics such as relative sliding friction at the driving point, improving the transmission efficiency, increasing the overall vertical stiffness, and improving the first-order mode;

[0025] (3) Furthermore, the magnetic preload force between the motor flexible rod and the transmission mechanism is temporarily isolated by the rotation of the baffle, thereby realizing online replacement and maintenance of the motor and the flexible connecting rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A top view of a movable lens adjustment mechanism provided by an embodiment of the present invention;

[0027] Figure 2 A top axonometric view of a movable lens adjustment mechanism provided by an embodiment of the present invention;

[0028] Figure 3 A bottom-up isometric view of a movable lens adjustment mechanism provided by an embodiment of the present invention;

[0029] Figure 4 The movable lens adjustment mechanism provided in the embodiment of the present invention is along Figure 1 Radial partial cross-sectional view of the middle BB;

[0030] Figure 5 The movable lens adjustment mechanism provided in the embodiment of the present invention is along Figure 1 Middle AA radial partial cross-sectional view;

[0031] Figure 6 is a first axonometric view of the flexible connecting rod in an embodiment of the present invention;

[0032] Figure 7 Schematic diagram of the structure of the position adjustment unit in an embodiment of the present invention;

[0033] Figure 8 Schematic diagram of the disassembly and assembly components in the normal working state of the motor and the online disassembly and replacement state according to the embodiment of the present invention;

[0034] Figure 9 is a second axonometric view of the flexible connecting rod in an embodiment of the present invention;

[0035] Figure 10 is an axial cross-sectional view of a transmission assembly according to an embodiment of the present invention;

[0036] Figure 11 A schematic diagram of the motion of a transmission assembly in an embodiment of the present invention;

[0037] The descriptions of the reference numerals are as follows:

[0038] 1-lens group; 2-lens barrel; 3-centering spring; 4-position adjustment unit; 5-position sensor; 6-preload support unit;

[0039] 101- lens; 102- lens base;

[0040] 401-driving motor; 402-first sealing ring; 403-sleeve; 404-second sealing ring; 405-transmission assembly; 406-disassembly assembly; 407-adjustment gasket;

[0041] 501-position sensor; 502-mounting plate;

[0042] 601-preload spring; 602-spring seat; 603-adapter plate;

[0043] 4051-fastening nut; 4052-flexible connecting rod; 4053-magnet; 4054-flexible transmission block; 4055-fastening bolt;

[0044] 4052e, 4052f, 4052g - three stepped surfaces at the output end of the flexible connecting rod; 4052h - pre-tightening surface of the flexible connecting rod;

[0045] 4054e-flexible transmission block lever input surface; 4054f-flexible transmission block output end;

[0046] 4052a, 4052b - horizontal right-angle notch hinges; 4052c, 4052d - vertical right-angle notch hinges;

[0047] 4054a, 4054b, 4054c, 4054d - flexible transmission block hinges;

[0048] 4061-Adjusting screw; 4062-Connecting block; 4063-Baffle; 4064-Nut; 4065-Pin. DETAILED DESCRIPTION

[0049] In order to make the objects, advantages and features of the present invention clearer, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis required to be shown in each drawing is different, and sometimes different proportions are used. It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third" and the like in the specification are only used to distinguish between the various components, elements, steps, etc. in the specification, and are not used to represent the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0050] Please refer to Figures 1 to 3 The embodiment of the present invention provides a movable lens adjustment mechanism, which includes a lens group unit and a plurality of position adjustment units 4, wherein:

[0051] The lens assembly unit includes: a lens base 102, a lens barrel 2 and a centering spring 3. The lens base 102 is used to fix the lens 101 and is flexibly connected to the lens barrel 2 via the centering spring 3. Specifically, the lens 101 is fixed to the lens base 102 by gluing at multiple points to form the lens assembly 1. The lens base 102 is flexibly connected to the lens barrel 2 via the centering spring 3, and the center position of the lens 101 is defined by the centering spring 3.

[0052] The plurality of position adjustment units 4 are arranged along the circumference of the lens barrel 2, and the position adjustment unit 4 includes: a driving motor 401 and a transmission assembly 405, Figure 10 The transmission assembly 405 includes: a flexible connecting rod 4052 and a flexible transmission block 4054 with a parallelogram flexible hinge. The drive motor 401 is used to provide a radial thrust along the lens barrel 2 to cause the flexible connecting rod 4052 to produce axial and vertical displacements, and push the flexible transmission block 4054 so that the output end of the flexible transmission block 4054 drives the lens holder 102 to produce displacement along the optical axis. Specifically, the flexible transmission block 4054 is pushed to use the parallelogram flexible hinge as a rotation fulcrum to rotate to produce axial and vertical displacements, thereby causing the output end of the flexible transmission block 4054 to drive the lens holder 102 to produce displacement along the optical axis.

[0053] The movable lens 101 adjustment mechanism provided in this embodiment adopts a flexible connecting rod + lever + parallelogram flexible hinge type transmission mechanism to realize radial drive input and vertical transmission output, thereby improving the linear proportional motion scaling ratio and achieving large stroke and high-precision motion.

[0054] Depend on Figure 1The X / Y direction is horizontal radial direction, and the Z direction is vertical direction (optical axis direction). The X, Y and Z directions are orthogonal to each other.

[0055] Please refer to Figure 2 The number of the position adjusting units 4 can be 3, and the three position adjusting units 4 are uniformly arranged along the circumference of the lens barrel 2, i.e. arranged at intervals of 120°, to drive the three-degree-of-freedom movement of the lens holder 102 RX / RY / DZ, so as to realize the relative position adjustment of the lens 101 in the vertical translation and tilt relative to the optical axis.

[0056] The centering spring sheet 3 can be an annular sheet, and the lens barrel 2 and the lens holder 102 are connected together through a plurality of uniformly distributed bolts, so as to provide certain axial load stiffness and large enough radial and tangential stiffness (>1000 times the axial stiffness), to ensure that the radial and tangential motion crosstalk of the lens 101 is negligible (DX / DY / RZ <±10 nm), the vertical motion displacement is ≥±0.2mm, and the stiffness meets the overall structural modal requirement of the objective lens (>200Hz), so as to realize the centering function of the lens 101. That is, the lens holder 102, the lens barrel 2 and the centering spring sheet 3 are concentrically arranged.

[0057] Please refer to Figure 3 The movable lens 101 adjusting mechanism can further include a plurality of position sensors 5, and the plurality of position sensors 5 are arranged along the circumference of the lens barrel 2 and arranged on the inner side of the lens barrel 2. The plurality of position sensors 5 are used to measure the three-degree-of-freedom relative motion position of the lens 101 by detecting the relative position between the lens holder 102 and the bottom. Specifically, the number of the position sensors 5 can be 3, each position sensor 5 is installed on the inner side of the lens barrel 2 through a mounting plate 502, the effective detection distance of the position sensor 5 relative to the bottom of the lens holder 102 is 0.2mm-0.5mm, and the three position sensors 5 are uniformly arranged along the circumference of the lens barrel 2, i.e. arranged at intervals of 120°, to realize the three-point Z direction relative position measurement of the lens holder 102, and finally realize the three-degree-of-freedom relative motion position measurement of the lens 101 RX / RY / DZ through coordinate system matrix transformation.

[0058] Please refer to Figure 4 and combine with Figure 3The movable lens 101 adjustment mechanism may further include a plurality of pre-tightening support units 6 sequentially arranged along the circumference of the lens barrel 2. The plurality of pre-tightening support units 6 are fixed to the lens barrel 2 and are used to provide gravity balance and initial support for the lens base 102. The number of the pre-tightening support units 6 may be 6, and the 6 pre-tightening support units 6 are evenly arranged along the circumference of the lens barrel 2, that is, arranged at intervals of 60°, to achieve gravity balance and initial support for the lens base 102, reduce driving force and ensure the vertical initial position of the lens 101. Specifically, the pre-tightening support unit 6 may include a pre-tightening spring 601, a spring seat 602 and an adapter plate 603. The pre-tightening spring 601 is arranged in the spring seat 602, and one end of the pre-tightening spring 601 is fixed to the inner side of the lens barrel 2 through the adapter plate 603, and the other end is connected to the lens base 102.

[0059] Due to vertical space limitations, in this embodiment, when there are three position adjustment units 4, three position sensors 5, and six preload support units, the positions of the position adjustment units 4, the position sensors 5, and the preload support units 6 can be arranged as follows: along the circumference of the lens barrel 2, one position adjustment unit 4 is provided on one side of each preload support unit 6 and one position sensor 5 is provided on the other side, with each position adjustment unit 4 and position sensor 5 spaced 30° apart. That is, between every two adjacent position adjustment units 4, one position sensor 5 and two preload support units 6 are provided, and two preload support units 6 are separated by one position sensor 5; between every two adjacent position sensors 5, one position adjustment unit 4 and two preload support units 6 are provided, and two preload support units 6 are separated by one position adjustment unit 4.

[0060] Due to vertical space limitations, the drive motor 401 can be fixed to the outside of the lens barrel 2 by fasteners, the flexible connecting rod 4052 is arranged along the radial direction of the lens barrel 2, and the flexible transmission block 4054 is fixed to the inside of the lens barrel 2.

[0061] For further information, see Figure 5 The position adjustment unit 4 also includes a sleeve 403. The output shaft of the drive motor 401 is connected to the flexible connecting rod 4052 after passing through the sleeve 403. The output shaft of the drive motor 401 and the sleeve 403, as well as the sleeve 403 and the lens barrel 2 are sealed by sealing rings. A first sealing ring 402 is provided on the output shaft of the drive motor 401, and a second sealing ring 404 is sleeved in the sealing groove of the sleeve 403. The motor end can be sealed by the first sealing ring 402 and the second sealing ring 404 to prevent pollution to the internal environment of the objective lens.

[0062] In this embodiment, the drive motor 401 can be a stacked piezoelectric ceramic motor or a linear actuator that meets the requirements for dimensions, motion resolution, displacement range, and thrust. It provides axial thrust as the driving force, without shear force output. Due to constraints such as overall dimensions, load capacity, displacement range, and adjustment accuracy, the axial thickness and radial cross-sectional area of ​​the piezoelectric ceramic drive motor 401 are significantly limited, resulting in a typical maximum thrust of 25N-40N.

[0063] In this embodiment, preferably, the position adjustment unit 4 also includes an adjustment gasket 407, the flexible transmission block 4054 is fixed on the inner side of the lens barrel 2, and the output end of the flexible transmission block 4054 is connected to the lens holder 102 along the optical axis direction through the adjustment gasket 407, and the adjustment gasket 407 is used to adjust the initial height and inclination of the lens 101 by changing the thickness.

[0064] The output shaft of the drive motor 401 can be connected to the flexible connecting rod 4052 by a threaded connection. In one embodiment, the input end of the flexible connecting rod 4052 is an externally threaded screw, and the output shaft of the drive motor 401 has an internal thread. After the two are threadedly connected, the axial position is adjusted and locked by a tightening nut.

[0065] In addition, preferably, the position adjustment unit 4 also includes: a magnet 4053 fixed to the flexible transmission block 4054; one end of the flexible connecting rod 4052 is connected to the working end of the drive motor 401, and the other end of the flexible connecting rod 4052 is fixedly connected to the magnet 4053 through a magnetic pre-tightening force. That is, the magnetic pre-tightening force of the surface of the magnet 4053 on the pre-tightening surface of the flexible connecting rod 4052 is used to achieve the magnetic pre-tightening connection between the flexible connecting rod 4052 and the flexible transmission block 4054, that is, the fixed connection between the drive motor 401 and the flexible transmission block 4054 is achieved. The magnet 4053 can specifically be a magnet with a seat, and the flexible transmission block 4054 has a mounting groove, and the magnet with a seat is installed in the mounting groove by a fastening bolt.

[0066] See Figure 6 and Figure 10 , further preferably, the output end of the flexible connecting rod 4052 has a plurality of stepped surfaces arranged along the circumferential direction, and the plurality of stepped surfaces are in point contact with the flexible transmission block 4054. The radial component force generated by the plurality of stepped surfaces relative to the lever input surface 4054e of the flexible transmission block 4054 is smaller than the maximum static friction force between the flexible connecting rod 4052 and the flexible transmission block 4054, thereby ensuring that there is no relative friction displacement between the flexible connecting rod 4052 and the flexible transmission block 4054. Figure 6As shown in the example, the number of the step surfaces may be three, namely step surface 4052e, step surface 4052f and step surface 4052g.

[0067] In addition, since the movable lens 101 moves at a high frequency, in order to meet the high life requirements of the lithography machine, the drive motor 401 needs to have an online replacement and maintenance function, so please refer to Figure 7 Combined with Figure 8 Preferably, in this embodiment, the position adjustment unit 4 also includes a dismantling component, which includes a baffle 4063, one end of which is fixed to the flexible transmission block 4054, and the other end rotates around the axis of the flexible connecting rod 4052. When it rotates to the gap between the flexible connecting rod 4052 and the magnet 4053, the fixed connection between the flexible connecting rod 4052 and the magnet 4053 is released.

[0068] The blocking piece 4063 can be made of a relatively thin thickness of 0.2mm-0.3mm, and its shielding surface is semicircular with a circular arc transition connection surface. The blocking piece 4063 is formed by punching austenitic stainless steel sheet with weak magnetism, high strength and high rigidity to ensure that its thickness is small enough and static deformation is small, so as to shield the magnetic attraction.

[0069] The baffle 4063 can be fixed to the flexible transmission block 4054 via a connecting block 4062 and rotated by an adjustment screw 4061. Specifically, the adjustment screw 4061 has external threads that pass through the motor adjustment hole, the lens barrel threaded hole, and the flexible transmission block through-hole, and then threadedly engage with the lens barrel threaded hole. The connecting block 4062 is inserted from one end of the adjustment screw 4061, and the axial position of the baffle 4063 is adjusted and locked by a double nut 4064 at the front and back. The baffle 4063 can be fixed to the connecting block 4062 by gluing.

[0070] The dismantling assembly may further include a limiting member 4065, which is fixed to the flexible transmission block 4054 and is used to limit the rotation angle of the blocking piece 4063. When the blocking piece 4063 rotates until it contacts the limiting member 4065, the blocking piece 4063 covers the end surface of the magnet 4053 near the flexible connecting rod 4052. In one specific embodiment, the blocking piece 4063 has a limiting groove, and the limiting member 4065 is a pin. The blocking piece 4063 rotates around the pin. When the pin is engaged in the limiting groove, the blocking piece 4063 covers the end surface 4052h of the magnet 4053 near the flexible connecting rod 4052 (i.e., the magnetic pre-tightening surface of the magnet 4053).

[0071] The specific working process of the dismantling assembly is as follows:

[0072] When the adjustment mechanism of the movable lens 101 is in normal working condition, the flexible connecting rod 4052 is fixedly connected to the flexible transmission block 4054 by a magnetic pre-tightening force; at this time, the adjustment screw 4061 is in close contact with the mounting surface of the lens barrel 2. That is, when the adjustment screw 4061 is tightened, the blocking piece 4063 is just outside the flexible transmission block 4054, and the connecting block 4062 forms a certain angle with respect to the transmission center of the pre-tightening surface of the flexible connecting rod 4052, and the angle can be, for example, 65°-70°.

[0073] When it is necessary to remove and replace the drive motor 401 and the flexible connecting rod 4052 online, the adjusting screw 4061 is rotated counterclockwise at a certain angle of 65°-70° from the motor end to loosen the adjusting screw 4061 relative to the mounting surface of the lens barrel 2, and at the same time, the connecting block 4062 and the blocking piece 4063 are driven to rotate, so that the blocking piece 4063 is rotated and inserted into the magnetic pre-tightening gap between the flexible connecting rod 4052 and the magnet 4053, and under the contact and limiting constraint of the limiting groove of the connecting block 4062 and the pin, it is ensured that the shielding surface of the blocking piece 4063 just completely covers the magnetic pre-tightening surface of the magnet 4053, isolates the magnetic attraction of the magnet 4053 to the flexible connecting rod 4052, eliminates the fixed connection state of the magnet 4053 and the drive motor 401, and then removes the fastener at the end of the drive motor 401. It is easy to achieve online removal and replacement of the drive motor 401 and the flexible connecting rod 4052 by a small removal force.

[0074] When it is necessary to restore the fixed connection state between the drive motor 401 and the flexible connecting rod 4052, tighten the adjustment screw 4061 clockwise to ensure that the baffle 4063 rotates out of the magnetic attraction area, restore the magnetic preload force between the flexible connecting rod preload surface 4052h and the flexible transmission block lever input surface 4054e, and achieve fixed connection.

[0075] The disassembly component structure provided in this embodiment is simple and easy to operate, which can greatly shorten the disassembly and replacement time of the motor in a fixed state and reduce maintenance time.

[0076] See Figure 9 Combined with Figure 10 In this embodiment, the flexible connecting rod 4052 has two horizontal right-angle notch hinges 4052a and 4052b and two vertical right-angle notch hinges 4052c and 4052d. Under the drive of the driving motor 401, the flexible connecting rod 4052 generates axial displacement and radial displacement through the horizontal right-angle notch hinges 4052a and 4052b, and generates displacement along the optical axis through the vertical right-angle notch hinges 4052c and 4052d.

[0077] The flexible connecting rod 4052 can be made of martensitic stainless steel with strong magnetism, high strength and good comprehensive mechanical properties, and the right-angle notch groove in the middle is processed by precision wire cutting. The flexible connecting rod 4052 has a large axial rigidity, which ensures the transmission of the axial driving force of the drive motor 401; and processing two horizontal right-angle notch hinges 4052a and 4052b on the flexible connecting rod 4052 can make it have a certain RY direction flexibility, produce RY direction bending deformation, and produce a certain axial and radial displacement, so that when the lever input surface 4054e of the flexible transmission block 4054 is pushed to rotate around the rotation center RY direction, the three step surfaces 4052e, 4052f, 4052g at the output end of the flexible connecting rod 4052 relative to the radial distribution generated by the lever input surface 4054e of the flexible transmission block 4054 The force is less than the maximum static friction force (under the action of magnetic preload, the static friction coefficient of general metal surface is less than 0.5), thereby ensuring that there is no relative friction displacement between the flexible connecting rod 4052 and the flexible transmission block 4054; by changing the thickness, width (equivalent shaft diameter), length and other structural parameters of the horizontal right-angle notch hinges 4052a, 4052b, the RY-direction bending stiffness and strength of the flexible connecting rod 4052 can be changed, thereby meeting the constraints of the maximum vertical output displacement, input force and other constraints of the flexible transmission block 4054, avoiding the introduction of nonlinear disturbance forces such as sliding friction, reducing stress concentration damage to the structure and the jamming of the mechanism transmission.

[0078] Processing two vertical right-angle notch hinges 4052c and 4052d on the flexible connecting rod 4052 can make it have a certain RZ-direction flexibility, produce RZ-direction bending deformation, and produce a certain axial and radial displacement, ensuring that the radial component force generated by the three step surfaces 4052e, 4052f, and 4052g at the output end of the flexible connecting rod 4052 relative to the lever input surface 4054e of the flexible transmission block 4054 is less than the maximum static friction force (under the action of magnetic preload, the static friction coefficient of general metal surfaces is less than 0.5), thereby ensuring that there is no relative friction displacement between the flexible connecting rod 4052 and the flexible transmission block 4054; at the same time, it can absorb non-functional The deformation stress caused by actual processing errors, assembly errors or movement inclination in the DY / RZ direction can be reduced to avoid the mechanism from being stuck due to structural stress damage; the RZ direction bending stiffness and strength of the flexible connecting rod 4052 can be changed by changing the thickness, width (equivalent shaft diameter), length and other structural parameters of the vertical right-angle notch hinges 4052c and 4052d; in order to improve the transmission energy efficiency and the overall modality of the mechanism, in principle, under the premise of meeting the constraints of strength, maximum output displacement, maximum output, spatial size, maximum static friction, etc., the axial and RY / RZ direction stiffness of the flexible connecting rod 4052 should be increased as much as possible to reduce the parasitic displacement in the non-functional direction.

[0079] The stiffness / strength of the flexible connecting rod 4052 was simulated. Under the constraints of the maximum vertical output displacement of the flexible transmission block 4054 being 0.185 mm, the maximum radial component force being less than the maximum static friction force being 15.6 N, and the strength (equivalent stress) being less than 250 MPa, the equivalent linear stiffness in the RY direction is K1 = 190.5 N, the equivalent linear stiffness in the RZ direction is K2 = 419.7 N, and the maximum equivalent stress at the hinge is 238.7 MPa.

[0080] The flexible transmission block 4054 is made of a metal material with weak magnetism or no magnetism and high strength / elastic modulus ratio, which ensures that it has greater flexibility, high strength and good fatigue resistance, meets the requirements of stiffness, deformation displacement and strength, and has magnetic isolation characteristics and is not affected by magnetic attraction; through precision wire cutting processing, it is Figure 10 Holes and slots are punched through the positions 4054a, 4054b, 4054c, and 4054d shown to form four parallel and opposite circular arc-shaped notched hinges. The four hinges 4054a, 4054b, 4054c, and 4054d are equivalent to a plane rotation pair, and their rigid parts are connected to form a parallelogram linkage mechanism. The rotation of the four hinges can realize two-dimensional vertical approximate linear motion; by punching holes and slots through the output part 4054g of the flexible transmission block 4054, the radial stiffness of the output end 4054f of the flexible transmission block 4054 is reduced, thereby avoiding machining and assembly errors and stress concentration caused by excessive radial stiffness of the centering spring 3 and radial parasitic displacement of the flexible transmission block 4054 during tilting movement, thereby preventing the mechanism from getting stuck;

[0081] like Figure 11 From the simplified motion diagram of the transmission assembly 405, it can be seen that the hinges 4052a, 4052b, 4054a, 4054b, 4054c, and 4054d of the transmission assembly 405 can be approximately represented as a revolute pair; the output shaft of the driving motor 401 is threadedly fixedly connected to the flexible connecting rod 4052, and its driving force pushes the hinges 4052a and 4052b of the flexible connecting rod 4052 to bend and deform, generating axial and vertical displacements, pushing the lever 4054h of the flexible transmission block 4054 to use the flexible hinges 4054a and 4054b as rotation fulcrums based on the lever principle to perform displacement scaling (L2 / L1), and the rotation generates higher-resolution axial and vertical small displacements, prompting the output end 4054f of the flexible transmission block 4054 to perform approximately vertical linear motion, generating vertical micro-displacement;

[0082] Calculation shows that the degree of freedom of motion of the transmission component 405 is F=3*5-7*2=1, ensuring that the transmission component 405 has only one planar motion degree of freedom, namely, the vertical linear motion of the output end 4054f of the flexible transmission block 4054 without overconstraint.

[0083] A large-displacement static simulation was performed on the flexible transmission block 4054. At a stroke of 0.185 mm, that is, when the vertical output displacement of the output end of the flexible transmission block 4054 is 0.185 mm, the driving displacement reaction force of the driving motor 401 is 28.5 N, the parasitic displacement crosstalk in the non-functional direction (DX / DY) is less than 150 nm, and the maximum equivalent stress is 249.2 MPa.

[0084] The flexible transmission block 4054 was subjected to a small displacement static simulation parameter table. As shown in the table, at a stroke of 0.01 mm, that is, when the vertical output displacement of the output end 4054f of the flexible transmission block 4054 is 0.01 mm, the parasitic displacement crosstalk in the non-functional direction (DX / DY) is less than 10 nm, and the maximum equivalent stress is 13.5 MPa.

[0085] In summary, the movable lens adjustment mechanism and lithography equipment provided by the embodiments of the present invention include: a lens group unit and multiple position adjustment units; wherein, the lens group unit includes: a lens seat, a lens barrel and a centering spring, the lens seat is used to fix the lens, and is flexibly connected to the lens barrel through the centering spring; multiple position adjustment units are arranged along the circumference of the lens barrel, and the position adjustment unit includes: a drive motor and a transmission assembly, the transmission assembly includes: a flexible connecting rod and a flexible transmission block with a parallelogram flexible hinge, the drive motor is used to provide a radial thrust along the lens barrel to cause the flexible connecting rod to generate axial and vertical displacement, and push the flexible transmission block to rotate with the parallelogram flexible hinge as a rotation fulcrum to generate axial and vertical displacement, thereby causing the output end of the flexible transmission block to drive the lens seat to generate displacement along the optical axis. Compared with the existing technology, it has the following advantages:

[0086] (1) The motor is placed radially outward to increase the vertical space size, improve the vertical leverage ratio of the transmission mechanism, increase the motion scaling ratio, and improve the transmission accuracy;

[0087] (2) The transmission mechanism strictly moves in a single-degree-of-freedom plane without redundant constraints, and the radial flexible hinge of the double-Hooker hinge flexible rod can absorb the stress generated by assembly in non-functional directions or movement tilt, avoiding stress damage and causing the mechanism to jam, thereby improving movement reliability;

[0088] (3) The motor drive rod and the transmission block are fixedly connected by pre-tightening with magnet 4053, eliminating the nonlinear characteristics and low transmission efficiency caused by relative sliding friction.

[0089] Furthermore, it should be recognized that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. Any person skilled in the art can utilize the above disclosed technical content to make many possible changes and modifications to the technical solution of the present invention without departing from the scope of the technical solution of the present invention, or modify the technical solution of the present invention into equivalent embodiments with equivalent changes. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A movable lens adjustment mechanism, characterized in that: include: A lens unit and a plurality of position adjustment units; wherein, The lens assembly unit comprises: a lens seat, a lens barrel and a centering spring, wherein the lens seat is used to fix the lens and is flexibly connected to the lens barrel through the centering spring; A plurality of position adjustment units are arranged along the circumference of the lens barrel, each comprising a drive motor and a transmission assembly, wherein the transmission assembly comprises a flexible connecting rod and a flexible transmission block having a parallelogram-shaped flexible hinge, wherein the drive motor is configured to provide a radial thrust along the lens barrel to cause the flexible connecting rod to generate axial and vertical displacements, thereby pushing the flexible transmission block so that the output end of the flexible transmission block drives the lens holder to generate displacement along the optical axis. The position adjustment unit further includes: a magnet fixed to the flexible transmission block; one end of the flexible connecting rod is connected to the working end of the drive motor, and the other end of the flexible connecting rod is fixedly connected to the magnet gap through a magnetic preload force; The position adjustment unit also includes a dismantling component, which includes a baffle, one end of which is fixed to the flexible transmission block, and the other end of which rotates around the axis of the flexible connecting rod. When it rotates to the gap between the flexible connecting rod and the magnet, the fixed connection between the flexible connecting rod and the magnet is released.

2. The movable lens adjustment mechanism according to claim 1, wherein: The dismantling assembly also includes a limiter, which is fixed to the flexible transmission block and is used to limit the rotation angle of the baffle. When the baffle rotates to contact the limiter, the baffle covers the end surface of the magnet close to the flexible connecting rod.

3. The movable lens adjustment mechanism according to claim 1, wherein: The output end of the flexible connecting rod has a plurality of step surfaces arranged along the circumferential direction, and the plurality of step surfaces are in point contact with the flexible transmission block. The radial component force generated by the plurality of step surfaces relative to the lever input surface of the flexible transmission block is less than the maximum static friction force between the flexible connecting rod and the flexible transmission block.

4. The movable lens adjustment mechanism according to claim 1, wherein: The flexible connecting rod has two horizontal right-angle notch hinges and two vertical right-angle notch hinges. Under the drive of the driving motor, the flexible connecting rod generates axial displacement and radial displacement through the horizontal right-angle notch hinges, and generates displacement along the optical axis through the vertical right-angle notch hinges.

5. The movable lens adjustment mechanism according to claim 1, wherein: The position adjustment unit also includes an adjustment gasket, the flexible transmission block is fixed on the inner side of the lens barrel, and the output end of the flexible transmission block is connected to the lens seat along the optical axis through the adjustment gasket, and the adjustment gasket is used to adjust the initial height and inclination of the lens by changing the thickness.

6. The movable lens adjustment mechanism according to claim 1, wherein: The driving motor is fixed on the outside of the lens barrel, the flexible connecting rod is arranged along the radial direction of the lens barrel, and the flexible driving block is fixed on the inside of the lens barrel.

7. The movable lens adjustment mechanism according to claim 6, wherein: The position adjustment unit also includes a sleeve. The output shaft of the drive motor is connected to the flexible connecting rod after passing through the sleeve. The output shaft of the drive motor and the sleeve, as well as the sleeve and the lens barrel are sealed by sealing rings.

8. The movable lens adjustment mechanism according to claim 1, wherein: The movable lens adjustment mechanism also includes multiple position sensors, which are arranged along the circumference of the lens barrel and on the inner side of the lens barrel. The multiple position sensors are used to measure the three-degree-of-freedom relative motion position of the lens by detecting the relative position between the lens and the bottom of the lens seat.

9. The movable lens adjustment mechanism according to claim 1, wherein: The movable lens adjustment mechanism further comprises a plurality of pre-tightening support units sequentially arranged along the circumference of the lens barrel. The plurality of pre-tightening support units are fixed to the lens barrel and are used for performing gravity balancing and initial support on the lens seat.

10. The movable lens adjustment mechanism according to claim 9, wherein: The preload support unit includes a preload spring, a spring seat and an adapter plate. The preload spring is arranged in the spring seat, and one end of the preload spring is fixed to the inner side of the lens barrel through the adapter plate, and the other end is connected to the lens seat.

11. A lithographic apparatus, characterized in that: include: The movable lens adjustment mechanism according to any one of claims 1 to 10.

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