A micro-motion platform

Abstract

The present invention relates to the field of semiconductor technology, and in particular to a micro-motion platform, comprising: a carrying platform, wherein a through hole and a mounting groove are provided on the upper surface of the carrying platform, wherein the through hole is located at the center of the mounting groove, and a first driving mechanism for driving the carrying platform to rise and fall is provided on the lower surface of the carrying platform; a detection platform, which is located on the carrying platform and is used to adsorb wafers placed on the surface of the detection platform; a guide portion, wherein the guide portion comprises a fixed portion and at least one elastic portion, wherein the fixed portion is located in the through hole and fixed on a beam crossing the bottom of the carrying platform, wherein the elastic portion is located in the mounting groove and is arranged around the circumference of the fixed portion, wherein one end is connected to the fixed portion and the other end is fixed in the mounting groove, wherein when the first driving mechanism drives the carrying platform to rise and fall, the elastic portion undergoes elastic deformation around its connection position with the fixed portion so that the carrying platform moves only in one direction.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a micro-motion platform. Background Art

[0002] In the field of wafer adsorption and precision processing, the fine-tuning platform plays a vital role, which is directly related to the accuracy of wafer positioning and the quality of subsequent processing. However, when faced with the need for wafer fine-tuning, the traditional rail-based fine-tuning platform has exposed some significant limitations, especially in terms of accuracy, stability and operational flexibility.

[0003] First, the inherent clearance problem of the rail adjustment method limits the accuracy of the fine-tuning platform. Due to the clearance between the rail and the slider, even in precision machining, a small displacement may cause deviation in wafer positioning, which is unacceptable for semiconductor manufacturing that requires extremely high precision. In addition, the wear of the rail increases over time, further exacerbating the problem of reduced accuracy.

[0004] Secondly, the guide rail system allows the wafer to move freely in multiple directions, which brings instability and control difficulty to wafer fine-tuning. The wafer needs to precisely control its rotation angle and position during the fine-tuning process, and the possibility of multi-directional movement increases the complexity of operation and the source of error, making it difficult to maintain stability and repeatability during the fine-tuning process.

[0005] Furthermore, the friction problem during the fine-tuning process cannot be ignored. The friction between the guide rail and the slider will not only reduce the response speed of the system, but also cause precision loss in long-term operation due to friction heat and wear. For wafers, a material that requires extremely high surface quality and dimensional accuracy, any slight friction effect may have a negative impact on the performance of the final product.

[0006] Therefore, the present application develops a micro-motion platform to solve the problems existing in the prior art. Summary of the invention

[0007] The purpose of the present invention is to provide a micro-motion platform to solve the problem in the prior art that when a wafer is fine-tuned, the wafer adjustment is inaccurate due to tiny displacements in different degrees of freedom.

[0008] The technical solution of the present invention is: a micro-motion platform, comprising:

[0009] A carrying platform, wherein a through hole and a mounting groove are formed on the upper surface of the carrying platform, wherein the through hole is located at the center of the mounting groove, and a first driving mechanism for driving the carrying platform to rise and fall is formed on the lower surface of the carrying platform;

[0010] A detection platform, located on the carrying platform, used for adsorbing the wafer placed on the surface of the detection platform;

[0011] The guide portion includes a fixed portion and at least one elastic portion, wherein the fixed portion is located in the through hole and fixed on a beam crossing the bottom of the supporting platform, and the elastic portion is located in the mounting groove and is arranged around the circumference of the fixed portion, with one end connected to the fixed portion and the other end fixed in the mounting groove. When the first driving mechanism drives the supporting platform to rise and fall, the elastic portion undergoes elastic deformation around the connection position between the elastic portion and the fixed portion to limit the supporting platform to move in only one direction.

[0012] Preferably, the elastic part is in the shape of a thin plate, and when the elastic part moves with the carrying platform, the elastic part enables the carrying platform to move only along the z-axis direction through elastic deformation.

[0013] Preferably, a groove is provided at a connection position between the elastic portion and the fixing portion, and a width of the elastic portion gradually increases along a direction approaching the fixing portion.

[0014] Preferably, the detection platform includes a suction cup and a vent cup, the surface of the suction cup is penetrated by at least three groups of vent holes, each group of vent holes is connected to the outside and are spaced apart from each other, at least three first channels and one second channel are surrounded by the vent cup, multiple first channels are respectively connected to multiple vent holes, and the suction cup is fixed to the vent cup through the second channel.

[0015] Preferably, a plurality of balancing components are fixed on the supporting platform, and the plurality of balancing components are evenly distributed around the detection platform. When air is ventilated to the balancing components, the balancing components generate air pressure along the radial direction of the detection platform, so that the detection platform is in a balanced position.

[0016] Preferably, there is a gap between the inner wall surface of the balancing component and the outer wall surface of the detection platform.

[0017] Preferably, a suspension component is provided between the carrying platform and the detection platform, and the suspension component includes a metal block, an air foot and a pair of magnets. A plurality of the metal blocks are respectively fixed on the lower surface of the detection platform, and the magnet and the air foot are both fixed on the carrying platform and correspond to the positions of the metal blocks. When the air foot is ventilated, a thrust is generated on the detection platform, and the magnet generates suction on the metal block, so that the detection platform is in a suspended state.

[0018] Preferably, the pair of magnets are respectively located on both sides of the air foot, and the orthographic projection of the metal block on the supporting platform covers the pair of magnets.

[0019] Preferably, a second driving mechanism is provided on the carrying platform, and the second driving mechanism drives the suspended detection platform to rotate around its own center.

[0020] Preferably, a positioning groove is provided on the edge of the detection platform for initial positioning of the detection platform, and a plurality of lifting holes are penetrated through the middle of the upper surface of the detection platform for avoiding the E-pin when it is lifted or lowered.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] (1) The voice coil motor provides support and drive at the four corners to ensure the stable operation of the carrier platform while avoiding the beam below. The precise control of the voice coil motor enables the carrier platform to perform a small lifting movement on the z-axis, thereby achieving a small adjustment of the wafer. The guide structure formed by the elastic part and the fixed part guides the carrier platform to move on the predetermined lifting path to prevent it from deviating from the predetermined trajectory, effectively limiting the small displacement of the carrier platform in the horizontal direction, and further improving the stability and alignment accuracy of the wafer.

[0023] (2) The inspection platform adopts the design of suction cup and ventilation cup. The ventilation holes are evenly distributed on the surface of the suction cup to ensure the uniformity of suction force on the entire suction cup action surface, which can adsorb the wafer faster and more effectively, while maintaining the stable adsorption of the wafer to avoid displacement or tilt caused by uneven suction force. The ventilation holes are distributed at intervals along the radial direction of the suction cup, which can generate suction force on the wafer in different directions at the same time, ensuring that large diameter wafers can also be stably adsorbed;

[0024] (3) The detection platform is air-floating, and the arc motor controls the rotation of the detection platform by adjusting the current. During the movement, the detection platform has no direct contact with the surroundings, which avoids damage to the detection platform due to physical factors such as friction and collision, and also avoids the detection platform affecting the wafer detection due to collision or friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0026] Figure 1 It is a structural schematic diagram of a micro-motion platform according to the present invention;

[0027] Figure 2 It is a structural schematic diagram of the guide part of the present invention;

[0028] Figure 3 It is a structural schematic diagram of the carrying platform of the present invention;

[0029] Figure 4 A top view of the suction cup of the present invention;

[0030] Figure 5A top view of the vent plate of the present invention;

[0031] Figure 6 This is a schematic diagram of the installation of the guide portion of the present invention on a bearing platform.

[0032] Among them: 1. Carrying platform; 11. Through hole; 12. Mounting slot; 13. First driving mechanism; 2. Detection platform; 21. Suction cup; 22. Ventilation plate; 23. Ventilation hole; 24. First channel; 25. Second channel; 26. Positioning slot; 27. Lifting hole; 3. Guide part; 31. Fixing part; 32. Elastic part; 33. Groove; 4. Balance component; 5. Suspension component; 51. Metal block; 52. Air foot; 53. Magnet; 6. Second driving mechanism. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with specific embodiments:

[0034] like Figure 1-Figure 3 As shown, a micro-motion platform includes a carrying platform 1, a detection platform 2 and a guide part 3. The upper surface of the carrying platform 1 is provided with a through hole 11 and a mounting groove 12. The guide part 3 includes a fixing part 31 and a plurality of elastic parts 32. The detection platform 2 is suspended on the carrying platform 1. The wafer is placed on the detection platform 2 and adsorbed on the surface of the detection platform 2. The through hole 11 provides an installation space for the fixing part 31. In actual application scenarios, the fixing part 31 can be installed on a beam crossing the bottom of the carrying platform 1. The plurality of elastic parts 32 are evenly distributed on the peripheral side of the fixing part 31. One end of the elastic part 32 is connected to one end face of the fixing part 31, and the other end is connected to the fixing part 31. Fixed on the mounting groove 12, the first driving mechanism 13 is a voice coil motor, and four voice coil motors are arranged at the four corners of the carrying platform 1, which not only provides support capacity to ensure the stable operation of the carrying platform 1, but also avoids the beam running through the bottom. Moreover, because the fixing part 31 is fixed on the beam and does not move, when the wafer needs to be fine-tuned in the vertical direction (z-axis), the voice coil motor operates to make the carrying platform 1 perform a small lifting movement on the z-axis. At this time, the elastic part 32 is deformed to guide the carrying platform 1 during the lifting process. At the same time, the detection platform 2 moves with the movement of the carrying platform 1 to achieve a small adjustment of the wafer.

[0035] Specifically, Figure 2As shown, when the carrying platform 1 is lifted and lowered along with the voice coil motor, the elastic part 32 is elastically deformed around the position where it is connected to the fixed part 31. The elastic part 32 is in the shape of a thin plate. After being connected to the fixed part 31, it can form a stable guiding structure to guide the carrying platform 1 to move on a predetermined lifting path and prevent it from deviating from a predetermined trajectory. Since the elastic part 32 can only move in the direction of its deformation and other directions are restricted, it can effectively limit the slight displacement of the carrying platform 1 in the horizontal direction, thereby improving the stability and alignment accuracy of the wafer during the processing. At the same time, the elastic part 32 has a certain elasticity and can play a role in buffering and shock absorption during the lifting and lowering of the carrying platform 1.

[0036] Preferably, three elastic portions 32 are arranged around the fixed portion 31, so that each elastic portion 32 has a certain width in the horizontal plane, which not only plays a guiding role, but also can prevent the carrying platform 1 from moving in other directions. When there are fewer elastic portions 32, the stability of the guidance is affected, resulting in the possibility that the carrying platform 1 may still move slightly in other directions. When there are more elastic portions 32, the width of each elastic portion 32 will be reduced due to the limited arrangement space of the carrying platform 1, and the narrower width will cause the elastic portion 32 to have insufficient bearing capacity. When subjected to force, it will not only cause deformation on the z-axis, but also generate torsion or deformation force in other directions, thereby causing the carrying platform 1 to be displaced in other directions, affecting the detection accuracy of the wafer.

[0037] In this embodiment, a groove 33 is provided at the connection position between the elastic portion 32 and the fixed portion 31, and the width of the elastic portion 32 in the direction close to the fixed portion 31 gradually increases. The groove 33 provides space for elastic deformation of the elastic portion 32, so that it can be elastically deformed when subjected to external force without being excessively restricted, allowing the elastic portion 32 to freely expand or contract when squeezed or stretched, thereby absorbing and dispersing external force, reducing stress and strain at the connection position, reducing friction and wear at the connection position between the fixed portion 31 and the elastic portion 32, thereby extending the service life of the overall structure. The width of the elastic portion 32 in the direction close to the fixed portion 31 gradually increases, which helps to optimize stress distribution. During the deformation process, the wider elastic portion 32 can better disperse stress and reduce stress concentration, thereby extending the service life of the elastic portion 32 and the fixed portion 31.

[0038] It should be noted that in actual application scenarios, the elastic part 32 is a leaf spring, and the deformation stroke of the leaf spring is relatively short, but the guiding accuracy is very high. This application is used to achieve micro-adjustment of the platform, so the leaf spring can fully meet the use requirements. At the same time, after meeting the guidance and accuracy requirements, the elastic part 32 can also be arranged in a limited space, and the space utilization rate is higher.

[0039] Initially, if Figure 1 and Figure 4As shown, the detection platform 2 needs to be positioned first, so a positioning groove 26 is provided on the edge of the detection platform 2 to provide a precise reference point to ensure that the detection platform 2 can be accurately placed in the predetermined position. In order to facilitate the replacement of the wafer, a plurality of lifting holes 27 are penetrated in the middle of the upper surface of the detection platform 2. During the wafer replacement process, the E-pin is inserted through the lifting hole 27 to lift the wafer from the detection platform 2, thereby facilitating the replacement of the wafer. Therefore, the holes reserved in the middle of the carrying platform 1 and the guide part 3 also provide convenience for the E-pin to lift the wafer, and the overall structural design is ingenious.

[0040] like Figure 4-Figure 5 As shown, when the wafer is fine-tuned by the carrying platform 1, it is necessary to ensure that the wafer is stably located on the detection platform 2 and will not shift in position as the detection platform 2 moves. Therefore, the detection platform 2 includes a suction cup 21 and a vent plate 22. A plurality of groups of vent holes 23 are penetrated through the surface of the suction cup 21, and a plurality of first channels 24 connected to the vent holes 23 are surrounded and arranged in the vent plate 22. Each group of vent holes 23 is evenly distributed on the surface of the suction cup 21, and the plurality of first channels 24 correspond one by one to the corresponding plurality of groups of vent holes. When negative pressure is generated by the vent plate 22 to generate suction on the surface of the vent holes 23, the uniform distribution of the vent holes 23 ensures the uniformity of the suction on the entire action surface of the suction cup 21, maintains stable adsorption of the wafer, avoids the displacement or tilt of the wafer due to uneven suction, and reduces the detection error caused by movement or shaking. At the same time, the evenly distributed vent holes 23 mean more suction points, which can adsorb the wafer faster and more effectively, and can significantly improve work efficiency. The multiple groups of vent holes 23 are provided to achieve adsorption of wafers of different sizes. In this embodiment, three groups of vent holes 23 and first channels 24 are provided respectively to achieve adsorption of 6-inch, 8-inch, and 12-inch wafers. Based on the size of the wafer to be adsorbed, it is only necessary to pass negative pressure in the corresponding first channel 24.

[0041] As for the method of fixing the suction cup 21 on the ventilation disc 22, the present embodiment also adopts the method of vacuum adsorption, so a second channel 25 is also provided on the ventilation disc 22, and the second channel 25 is provided on the outermost side of the ventilation disc 22. When ventilation is performed, the suction cup 21 is adsorbed on the ventilation disc 22 to prevent the suction cup 21 from detaching and shaking during movement, thereby improving the stability of the suction cup 21 and avoiding the generation of excess stress on the suction cup 21 when fixedly connected by fasteners, thereby affecting the final detection result.

[0042] Furthermore, each group of air holes 23 is distributed at radial intervals along the suction cup 21 and do not affect each other. A group of air holes 23 close to the center of the suction cup 21 is used to adsorb the suction cup 21 with a smaller diameter, and a group of air holes 23 farther from the center of the suction cup 21 cooperates with a closer group of air holes 23 to adsorb the suction cup 21 with a larger diameter, and generate suction on the wafer in different directions, so that the suction cup 21 can generate suction on the wafer in different directions at the same time, ensuring that large-diameter wafers can also be stably adsorbed. Since the air holes 23 are distributed at radial intervals and do not affect each other, it can be ensured that the wafer is subjected to uniform and stable suction during the adsorption process, which helps to reduce the deviation and shaking of the wafer during the detection process, thereby improving the accuracy and stability of the detection.

[0043] During the inspection process, the wafer usually needs to be rotated, which not only helps to find tiny defects on the surface of the wafer, but also improves the efficiency and accuracy of the inspection. When the wafer rotates, its guide rail system will generate friction, resulting in precision loss that affects the inspection of the wafer. Therefore, a suspension component 5 is provided between the carrier platform 1 and the inspection platform 2, and a second drive mechanism 6 and a balancing component 4 are provided on the side of the inspection platform 2. The balancing components 4 are evenly distributed on the circumference of the inspection platform 2. The balancing components 4 are constructed to be air-filled. When air is ventilated to the balancing components 4, the air flow generates air pressure along the radial direction of the inspection platform 2 through the balancing components 4. Specifically, the length of the ventilation pipe connected to each balancing component 4 is kept consistent to avoid attenuation and differences in air pressure during the transmission process, thereby achieving uniform distribution of air pressure on the inspection platform 2 and ensuring that the wafer is stably supported and fixed.

[0044] Specifically, Figure 6 As shown, the second driving mechanism 6 is an arc motor, which controls the rotation of the detection platform 2 by adjusting the current and changing the direction and size of the electromagnetic force. The balance of the detection platform 2 is maintained by the balance component 4, and the balance component 4 has no direct contact with the detection platform 2. The suspension component 5 includes a metal block 51, an air foot 52 and a pair of magnets 53. The multiple metal blocks 51 are evenly fixed on the lower surface of the ventilation disk 22, and the pair of magnets 53 and the air foot 52 are fixed on the supporting platform 1 and correspond to the positions of the metal blocks 51 respectively. The magnet 53 generates suction on the metal block 51 to generate a downward force on the detection platform 2. When the air foot 52 is ventilated, the air foot 52 will generate an upward force on the detection platform 2, thereby achieving the purpose of suspending the detection platform 2. At this time, the detection platform 2 has no direct contact with the surroundings, avoiding damage to the detection platform 2 due to physical factors such as friction and collision, and also avoiding the detection platform 2 affecting the detection of wafers due to collision or friction.

[0045] Furthermore, a pair of magnets 53 are respectively located on both sides of the air foot 52, and the orthographic projection of the metal block 51 on the supporting platform 1 covers the magnet 53, so that the magnetic force on the metal block 51 remains stable and the balance of the metal block 51 is ensured. Therefore, during the movement or rotation of the detection platform 2, slight vibrations or deviations are generated due to uneven magnetic force, thereby affecting the detection accuracy of the wafer.

[0046] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A micro-motion platform, characterized in that: include: A carrying platform (1), wherein the upper surface of the carrying platform (1) is provided with a through hole (11) and a mounting groove (12), the through hole (11) is located at the center of the mounting groove (12), and the lower surface of the carrying platform (1) is provided with a first driving mechanism (13) for driving the carrying platform (1) to rise and fall; A detection platform (2), located on the carrying platform (1), and used for adsorbing a wafer placed on the surface of the detection platform (2); A guide portion (3), the guide portion (3) comprising a fixed portion (31) and three elastic portions (32), the fixed portion (31) being located in the through hole (11) and fixed on a beam that crosses the bottom of the support platform (1), the elastic portion (32) being located in the mounting groove (12) and arranged around the circumference of the fixed portion (31), with one end connected to the fixed portion (31) and the other end fixed in the mounting groove (12), when the first driving mechanism (13) drives the support platform (1) to rise or fall, the elastic portion (32) undergoes elastic deformation around its connection position with the fixed portion (31), so that the support platform (1) moves in only one direction.

2. A micro-motion platform according to claim 1, characterized in that: The elastic part (32) is in the shape of a thin plate, and when the elastic part (32) moves with the carrying platform (1), the elastic part (32) enables the carrying platform (1) to move only along the z-axis direction through elastic deformation.

3. A micro-motion platform according to claim 2, characterized in that: A groove (33) is provided at a connection position between the elastic portion (32) and the fixing portion (31), and the width of the elastic portion (32) gradually increases in a direction approaching the fixing portion (31).

4. The micro-motion platform according to claim 1, characterized in that: The detection platform (2) comprises a suction cup (21) and a ventilation cup (22); at least three groups of ventilation holes (23) are formed through the surface of the suction cup (21); each group of ventilation holes (23) is connected to the outside and are arranged at intervals from each other; at least three first channels (24) and one second channel (25) are arranged around the ventilation cup (22); a plurality of the first channels (24) are respectively connected to a plurality of ventilation holes (23); and the suction cup (21) is fixed to the ventilation cup (22) via the second channel (25).

5. The micro-motion platform according to claim 1, characterized in that: A plurality of balancing components (4) are fixed on the support platform (1), and the plurality of balancing components (4) are evenly distributed in the circumference of the detection platform (2). When air is ventilated to the balancing components (4), the balancing components (4) generate air pressure along the radial direction of the detection platform (2), so that the detection platform (2) is in a balanced position.

6. A micro-motion platform according to claim 5, characterized in that: There is a gap between the inner wall surface of the balancing component (4) and the outer wall surface of the detection platform (2).

7. The micro-motion platform according to claim 1, characterized in that: A suspension component (5) is provided between the carrying platform (1) and the detection platform (2), the suspension component (5) comprising a metal block (51), an air foot (52) and a pair of magnets (53), a plurality of the metal blocks (51) are respectively fixed on the lower surface of the detection platform (2), the magnets (53) and the air foot (52) are both fixed on the carrying platform (1) and correspond to the positions of the metal blocks (51), when the air foot (52) is ventilated, a thrust is generated on the detection platform (2), and the magnets (53) generate a suction force on the metal blocks (51), so that the detection platform (2) is in a suspended state.

8. The micro-motion platform according to claim 7, characterized in that: The pair of magnets (53) are respectively located on both sides of the air foot (52), and the orthographic projection of the metal block (51) on the supporting platform (1) covers the pair of magnets (53).

9. The micro-motion platform according to claim 7, characterized in that: The carrying platform (1) is provided with a second driving mechanism (6), and the second driving mechanism (6) drives the suspended detection platform (2) to rotate around its own center.

10. The micro-motion platform according to claim 1, characterized in that: The edge of the detection platform (2) is provided with a positioning groove (26) for initial positioning of the detection platform (2), and a plurality of lifting holes (27) are penetrated through the middle of the upper surface of the detection platform (2) for avoiding the E-pin when it is lifted or lowered.

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