Static pressure pad, polishing apparatus, and silicon wafer

Abstract

Embodiments of the present disclosure disclose a hydrostatic pad, a polishing apparatus, and a silicon wafer. The hydrostatic pad is configured to clamp both sides of a silicon wafer in a pair in a double-sided polishing apparatus for a silicon wafer, and the hydrostatic pad includes a base having a fixed plane facing the silicon wafer, a plurality of hydrostatic blocks uniformly distributed vertically on the fixed plane and protruding from the fixed plane, and a drive module, wherein the plurality of hydrostatic blocks provide hydrostatic pressure to the silicon wafer via a fluid to support one side of the silicon wafer non-contact, and the drive module is configured to drive each hydrostatic block to move along a direction perpendicular to the fixed plane so that the first plane formed by the end of each hydrostatic block and the target plane on which the silicon wafer is located become parallel when the first plane is not parallel to the target plane.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and particularly to a hydrostatic pad, a polishing apparatus, and a silicon wafer.

Background Art

[0002] The manufacturing process of semiconductor silicon wafers usually includes processing steps such as crystal pulling, wire cutting, grinding, and polishing. Double-sided polishing is used as a polishing process to simultaneously polish both main surfaces of a silicon wafer to give the silicon wafer a surface with high flatness. In the double-sided polishing process, it is necessary to use a dedicated device to hold the silicon wafer so that the grinding wheel can polish both main surfaces of the silicon wafer simultaneously. Usually, such a holding device includes a pair of hydrostatic support members arranged opposite to each other, and the silicon wafer is vertically arranged between these two hydrostatic support members. The hydrostatic support member can form a fluid barrier between itself and the main surface of the silicon wafer, so that the silicon wafer is held upright without contacting the two hydrostatic support members. At the same time, both main surfaces of the silicon wafer can be polished using opposing grinding wheels. Compared with physical clamping, the fluid clamping method by the hydrostatic support member reduces damage to the silicon wafer and also enables the silicon wafer to move (rotate) tangentially with little friction against the surface of the hydrostatic support member.

[0003] In a double-sided polishing machine, it is necessary to adjust the angle of the opposing pair of grinding machines to correct the flatness of the silicon wafer. If the deflection angle of the left and right pair of grinding machines is too large during the grinding machine adjustment process, the silicon wafer will tilt if the grinding machines come into direct contact with the silicon wafer. Alternatively, even when holding the silicon wafer using the aforementioned dedicated device, the silicon wafer may tilt due to instability in the mechanical structure. In such situations, since the distance between the pair of hydrostatic support members is fixed, and the distance between one hydrostatic support member and the silicon wafer is also fixed, the silicon wafer comes into contact with the hydrostatic support member, resulting in friction between the silicon wafer and the hydrostatic support member, which worsens the flatness of the silicon wafer and even causes the generation of fragments.

[0004] After polishing is complete, the silicon wafer is pressed against the hydrostatic support member by a material loading device and the material is loaded. A dedicated device for holding the silicon wafer is driven to move the silicon wafer until it contacts the hydrostatic support member. The side of the silicon wafer that contacts the hydrostatic support member is held in place by the hydrostatic support member. If processing residue is scattered onto the hydrostatic support member during the processing process, or if the silicon wafer surface is not clean enough, the silicon wafer surface will be contaminated when it comes into contact with the hydrostatic support member, causing numerous pit-like defects to appear on the silicon wafer surface. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] To solve the above technical problems, it is desirable that the embodiments of this disclosure provide a hydrostatic pad, polishing apparatus, and silicon wafer that improve product quality by adjusting the distance between the hydrostatic pad and the silicon wafer by changing the structure of the hydrostatic pad in real time during the double-sided polishing process, thereby ensuring the stability of the polishing process and improving product quality, and that reduce the area on which the hydrostatic pad adheres to the silicon wafer, thereby improving surface damage to the silicon wafer. [Means for solving the problem]

[0006] The technical solution of this disclosure is implemented as follows:

[0007] In a first embodiment, the present disclosure provides a hydrostatic pad. The aforementioned static pressure pads are configured to form a pair in a double-sided polishing apparatus for silicon wafers and clamp both sides of the silicon wafer. The aforementioned static pressure pad is A base having a fixed plane toward the silicon wafer, Multiple static pressure blocks are uniformly distributed vertically along the fixed plane and protrude from the fixed plane, Includes a drive module, The plurality of static pressure blocks provide static pressure to the silicon wafer via a fluid to support one side of the silicon wafer in a non-contact manner. The drive module is configured to drive each static pressure block along a direction perpendicular to the fixed plane so that the first plane formed by the end of each static pressure block and the target plane on which the silicon wafer is located become parallel when the first plane formed by the end of each static pressure block and the target plane are not parallel.

[0008] Selectively, the hydrostatic pad further includes a support block provided on the fixed plane, the support block moves along a direction perpendicular to the fixed plane and protrudes from the fixed plane, and the support block is configured such that the protrusion height of the support block relative to the fixed plane is greater than the protrusion height of any of the plurality of hydrostatic blocks relative to the fixed plane.

[0009] The end of the support block is optionally provided with a plurality of suction holes, which adsorb the silicon wafer by vacuum.

[0010] Optionally, the hydrostatic pad further includes a sensor and a controller, the sensor being configured to detect the spatial position of the target plane, the controller transmitting a control signal to the drive module based on the spatial position of the target plane, and the drive module driving the movement of the plurality of hydrostatic blocks based on the control signal so that the first plane and the target plane are parallel.

[0011] Selectively, the sensor is a pressure sensor, and the pressure sensor is configured to detect changes in the static pressure received by the silicon wafer and to obtain the spatial orientation of the silicon wafer.

[0012] Selectively, the sensor is a distance sensor, and the distance sensor is configured to detect the distance between the silicon wafer and the first plane to obtain the spatial orientation of the silicon wafer.

[0013] Selectively, each static pressure block is provided with multiple through-holes at its end, which are configured to allow the fluid to flow out and support the silicon wafer in a non-contact manner.

[0014] The drive module may optionally include a hydraulic drive unit or a pneumatic drive unit for driving the movement of the hydrostatic block.

[0015] In a second embodiment, the Disclosure provides a polishing apparatus configured for polishing both sides of a silicon wafer, the polishing apparatus comprising a holding member for holding the silicon wafer along a vertical direction, two grinding plates provided symmetrically with respect to the holding member, and two hydrostatic pads provided symmetrically with respect to the holding member.

[0016] In a third embodiment, the disclosure provides a silicon wafer, which is obtained using the polishing apparatus described above. [Effects of the Invention]

[0017] Embodiments of the present disclosure provide a hydrostatic pad, a polishing apparatus, and a silicon wafer. The hydrostatic pad includes a base, a plurality of expandable and contractible hydrostatic blocks protruding from the surface of the base, and a driving module for driving the movement of the hydrostatic blocks. A first plane formed by the ends of the plurality of hydrostatic blocks is used to provide a hydrostatic pressure to the silicon wafer to hold the silicon wafer. The hydrostatic pad can adjust the expansion and contraction lengths of the plurality of hydrostatic blocks according to the target plane where the silicon wafer is located so that the first plane and the target plane where the silicon wafer is located are parallel, thereby changing the spatial position of the first plane. Thereby, when a large inclination occurs in the silicon wafer, it is ensured that the hydrostatic pad does not contact the silicon wafer, and the occurrence of fragments and the situation of hydrostatic pad damage can be avoided. In addition, the adsorption area of the hydrostatic pad on the silicon wafer can be reduced by the support block, and the back surface damage of the silicon wafer can be improved.

Brief Description of the Drawings

[0018] [Figure 1] It is a schematic structural diagram of a vertical polishing apparatus in the related art. [Figure 2] It is a schematic structural diagram of a polishing pad according to an embodiment of the present disclosure. [Figure 3] It is a schematic diagram of clamping an inclined silicon wafer using the polishing pad according to an embodiment of the present disclosure. [Figure 4] It is a schematic shape diagram of a polishing pad according to an embodiment of the present disclosure.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, the technical solutions according to the embodiments of the present disclosure will be clearly and completely described with reference to the drawings in the embodiments of the present disclosure.

[0020] As silicon wafer diameters continue to increase and the feature sizes of integrated circuits decrease, higher requirements are placed on the flatness and cleanliness of the silicon wafer surface, as well as on the degree of damage to the silicon wafer surface. Double-sided polishing refers to the process of polishing both sides of a silicon wafer simultaneously to produce a silicon wafer with a highly flat surface. During double-sided polishing using a vertical polishing apparatus, the silicon wafer must be held upright using a silicon wafer clamping device. The clamping device typically includes a pair of fluid hydrostatic pads, which are configured to support the silicon wafer in a non-contact manner by simultaneously applying fluid pressure to the two sides of the silicon wafer positioned between them. In the vertical polishing apparatus, the polishing apparatus for polishing the silicon wafer includes a pair of polishing plates positioned opposite each other, which simultaneously polish the two sides of the silicon wafer according to a predetermined polishing trajectory while the silicon wafer is supported by the pair of fluid hydrostatic pads.

[0021] When polishing both sides of a silicon wafer using a vertical polishing apparatus, the silicon wafer may tilt as expected or unexpectedly. For example, if the flatness of the silicon wafer needs to be corrected, this can be achieved by adjusting the deflection angle of the pair of polishing discs. Specifically, Figure 1 shows a schematic diagram of a vertical polishing apparatus in the relevant technology. As shown in Figure 1, the vertical polishing apparatus 30 includes a pair of polishing discs 31 and a pair of fluid hydrostatic pads 32. The pair of fluid hydrostatic pads 32 provide non-contact support for the silicon wafer W via a fluid L. To adjust the surface flatness of the silicon wafer, the pair of polishing discs 31 need to be deflected in the same direction. In such a case, the pair of polishing discs 31 deflect the silicon wafer W at the same deflection angle, and at this time, the silicon wafer W comes into contact with the surface of the pair of fluid hydrostatic pads 32, affecting the quality of the silicon wafer W or causing the generation of fragments.

[0022] After the processing is completed, the pair of polishing pads 31 retreat to their initial positions away from the silicon wafer W along their own central axes. The silicon wafer W is adsorbed by the hydrostatic pad on one side of the pair of hydrostatic pads 32 by vacuum pressure. After the mechanical arm for material input adsorbs the silicon wafer W from the opposite side, the adsorption by the hydrostatic pad stops, and the extraction of the wafer is completed. However, a lot of residues scatter on the pair of hydrostatic pads 32 during the processing. Since the pair of hydrostatic pads 32 do not have a self-cleaning function, when the silicon wafer W contacts the hydrostatic pad, it may cause a large number of pit-shaped defects on the surface of the silicon wafer W. In addition, contaminants adhering to the surface of the silicon wafer W may also cause a similar situation.

[0023] <​​​​Specifically, as shown in Figures 2 and 3, the hydrostatic pad 10 includes a base 11, a plurality of hydrostatic blocks 12, and a drive module (not shown). The base 11 has a fixed plane A facing the silicon wafer W, the plurality of hydrostatic blocks 12 are uniformly distributed on the fixed plane A along the vertical direction, and the plurality of hydrostatic blocks 12 can be moved by the drive module along a direction perpendicular to the fixed plane A such that the first plane B formed by the ends of each hydrostatic block 12 is parallel to the target plane C on which the silicon wafer W is located. Here, the number of the plurality of hydrostatic blocks 12 is at least two. The hydrostatic pad 10 changes the spatial orientation of the first plane B by changing the height at which the plurality of hydrostatic blocks 12 protrude from the fixed plane A, and when the silicon wafer W tilts, the spatial orientation of the first plane B can be changed by the above structure so that the first plane B and the target plane C are parallel.

[0025] Optionally, the hydrostatic pad 10 further includes a support block (not shown) for supporting the silicon wafer W, the support block being able to protrude from the fixed plane A of the base 11 by the drive module. When the silicon wafer W is material-loaded by a mechanical arm, the silicon wafer W moves until it contacts the hydrostatic pad 10, the support block protrudes from the fixed plane A, and the protrusion height of the support block relative to the fixed plane A is greater than the protrusion height of the plurality of hydrostatic blocks 12 relative to the fixed plane A, so that the support block can contact the silicon wafer W before each of the plurality of hydrostatic blocks 12 and provide support force to the silicon wafer W, further reducing the area of ​​the hydrostatic pad 10 for supporting the silicon wafer W and preventing damage to the back surface of the silicon wafer W.

[0026] When the associated components for polishing the silicon wafer W move and the silicon wafer W tilts during polishing, in order to avoid any impact on the quality of the silicon wafer W or the generation of fragments due to contact between the silicon wafer W and the hydrostatic pad 10, the hydrostatic pad 10 according to the embodiment of this disclosure, unlike conventional fluid hydrostatic pads, can keep the surface of the hydrostatic pad 10 facing the silicon wafer W at all times parallel to the silicon wafer W by changing the structure of the associated components on the side of the hydrostatic pad 10 facing the silicon wafer W. At the same time, in order to avoid scratching the surface of the silicon wafer W and causing damage to the silicon wafer W during the removal process, the hydrostatic pad 10 can further reduce the area of ​​the associated components for supporting the silicon wafer W.

[0027] Specifically, the base 11 is usually made of metal in order to stably support each component of the hydrostatic pad 10 so that the hydrostatic pad 10 can stably support the silicon wafer W. As shown in Figures 2 and 3, the base 11 has a fixed plane A and a central axis (not shown), the fixed plane A is the surface of the base 11 facing the silicon wafer W, the fixed plane A is located in a vertical plane, the central axis is perpendicular to the fixed plane A, and the plurality of hydrostatic blocks 12 are uniformly distributed on the fixed plane A along the vertical direction and protrude from the fixed plane A. As shown in Figures 2 to 4, the plurality of hydrostatic blocks 12 are configured to be of equal length along the vertical direction, and as shown in Figure 4, the plurality of hydrostatic blocks 12 are joined on the fixed plane A so as to match the shape of the base 11.

[0028] Before the silicon wafer W is tilted, the plurality of hydrostatic blocks 12 support the silicon wafer W by providing hydrostatic pressure to the silicon wafer W in a manner that protrudes from the fixed plane A at the same height, and the first plane B is parallel to the target plane C. As shown in Figure 2, the first plane B is located in a vertical plane, where the plurality of hydrostatic blocks 12 non-contact support one side of the silicon wafer W via a fluid. When the silicon wafer W is tilted, the spatial orientation of the silicon wafer W changes, which in turn changes the target plane C on which the silicon wafer W is located. Exemplarily, as shown in Figure 3, when the silicon wafer W is tilted in a clockwise direction and a conventional fluid hydrostatic pad is used, the tilting of the silicon wafer W and contact with the hydrostatic pad can result in poor polishing quality of the silicon wafer W or the generation of fragments. However, in the embodiments of this disclosure, if the silicon wafer W is tilted in a clockwise direction, that is, if the first plane B and the target plane C are not parallel, the plurality of hydrostatic blocks 12 are driven by the drive module to extend along the central axis of the base 11 so that the first plane B and the target plane C are parallel, thereby avoiding contact between the silicon wafer W and the hydrostatic blocks and preventing any impact on the polishing quality of the silicon wafer W or the generation of fragments.

[0029] Specifically, when the first plane B and the target plane C are no longer parallel, the plurality of hydrostatic blocks 12 are driven by the drive module to protrude from the fixed plane A by different distances along the central axis, so that the ends of each hydrostatic block 12 move to different positions along the central axis, thereby changing the spatial position of the first plane B formed by the ends of each hydrostatic block. Exemplarily, as shown in Figures 2 and 3, the plurality of hydrostatic blocks 12 include a total of five hydrostatic blocks from top to bottom in the vertical direction, and before the silicon wafer W tilts, the five hydrostatic blocks are installed on the fixed plane A in such a manner that they protrude from the fixed plane A by the same height, and the first plane B formed by the ends of the five hydrostatic blocks is located in the vertical plane and supports one side of the silicon wafer W by injecting fluid into the side of the silicon wafer W with static pressure. When the silicon wafer W is tilted as shown in Figure 3, the five hydrostatic blocks extend toward the silicon wafer W along the central axis such that the protruding distance increases uniformly from top to bottom, and as a result, the first plane B formed by the ends of the five hydrostatic blocks also tilts in a clockwise direction. However, the five hydrostatic blocks are not limited to extending toward the silicon wafer W along the central axis when driven by the drive module; any of the five hydrostatic blocks can also contract toward the silicon wafer W along the central axis, thereby achieving the effect of changing the spatial position of the first plane B.

[0030] In a double-sided polishing apparatus, hydrostatic pads 10 are provided on different sides of the silicon wafer W to support the silicon wafer W by providing fluid hydrostatic pressure. To make it easier for those skilled in the art to understand, when the hydrostatic pads 10 on both sides of the silicon wafer W need to be inclined, the inclination direction and angle of the first plane B of the two hydrostatic pads 10 are the same, but the expansion and contraction states of the hydrostatic blocks required to achieve the inclination are different. For example, as shown in Figure 3, the first plane B formed by a plurality of hydrostatic blocks 12 provided on the right side of the silicon wafer W is inclined clockwise, and the first plane B formed by a plurality of hydrostatic blocks 12 provided on the left side of the silicon wafer W is similarly inclined clockwise, but the expansion and contraction states of the plurality of hydrostatic blocks 12 required to achieve the inclination of the two first planes B are different.

[0031] The drive module includes a drive unit for driving the movement of each hydrostatic block, the drive unit may be selected as a hydraulic drive, a pneumatic drive, or other drive capable of moving the hydrostatic block. Exemplarily, the drive unit may be a motor-driven screw device, the screw device provided within the base 11, the end of the screw in the screw device connected to one end of the hydrostatic block 12 away from the silicon wafer W, the screw device being extendable and retractable along the central axis by the drive of the motor, and moving the hydrostatic block along the central axis.

[0032] To accurately acquire the specific spatial position of the target plane C and use it as a reference for the expansion and contraction of the hydrostatic block, the hydrostatic pad 10 further includes a sensor (not shown) and a controller (not shown), the sensor being configured to detect the spatial orientation of the silicon wafer W and acquire specific positional information of the target plane C, and the controller transmitting a control signal to the drive module based on the positional information of the target plane C so that the first plane B is tilted and the first plane B and the target plane C are parallel, thereby causing each drive unit of the drive module to expand and contract its corresponding hydrostatic block.

[0033] Specifically, the sensor is a pressure sensor, and is configured to detect the static pressure acting on the silicon wafer W, which is stably supplied by the plurality of static pressure blocks 12. In other words, the fluid flowing out from the plurality of static pressure blocks 12 applies static pressure to one side of the silicon wafer W, acting as a supporting force for the silicon wafer W. When the first plane B and the target plane C are parallel, the magnitude of the static pressure acting on each point on the silicon wafer W is equal and the direction is the same. When the silicon wafer W tilts, the pressure sensor detects the change in the static pressure acting on the silicon wafer W. The pressure sensor determines that the silicon wafer W has tilted by detecting the distribution of static pressures of different magnitudes, and grasps the change from the previous position of the silicon wafer W based on the distribution of static pressures of different magnitudes on the silicon wafer W, thereby obtaining the new spatial position of the target plane C after the silicon wafer W has tilted. The controller transmits a control signal to the drive module based on the new target plane C, and the drive module controls the expansion and contraction of each drive unit in accordance with the control signal so that the first plane B is tilted parallel to the target plane C, thereby expanding and contracting each corresponding hydrostatic block along the central axis direction.

[0034] In another embodiment of the present disclosure, the sensor is a distance sensor used to directly measure the distance between each point on the silicon wafer W and the fixed plane A of the base 11. Here, the distance refers to the straight-line distance between each point on the silicon wafer W and the fixed plane A, and the straight line is a horizontal line. If the distance between each point on the silicon wafer W and the fixed plane A does not match, it is determined that the silicon wafer W is tilted. The distance sensor obtains the angle between the target plane C and the fixed plane A based on the distance between each point on the silicon wafer W and the fixed plane A, the controller transmits a control signal to the drive module based on the angle, and the drive module controls the expansion and contraction of each drive unit in accordance with the control signal to expand and contract each corresponding hydrostatic block along the central axis direction so that the first plane B is tilted parallel to the target plane C.

[0035] Selectively, as shown in Figure 4, a plurality of through-holes T are uniformly provided on each hydrostatic block. The through-holes T are used to allow fluid to pass through the end face of the hydrostatic block under pressure and be injected toward the side of the silicon wafer W toward the hydrostatic block, thereby enabling the silicon wafer W to be supported by fluid hydrostatic pressure. In a double-sided polishing apparatus, fluid hydrostatic pressure is supplied to different sides of the silicon wafer W, and as shown in Figure 3, the hydrostatic pad 10 of the embodiment of this disclosure and another hydrostatic pad 20 are provided on different sides of the silicon wafer W, and together they provide fluid hydrostatic pressure to the silicon wafer W.

[0036] Selectively, the hydrostatic block includes a fluid pressure drive unit, the fluid pressure drive unit being configured to control the pressure of the fluid in each hydrostatic block so that, when the hydrostatic block applies hydrostatic pressure to the surface of the silicon wafer W in the target plane C, each hydrostatic block always applies a constant and equal amount of hydrostatic pressure to the surface of the silicon wafer W in the target plane C. Specifically, the fluid pressure drive unit includes a pressure cylinder for containing the fluid, a pressurizing unit, and a sensor. Here, the pressurizing unit is configured to eject the fluid from the through-hole T at a constant set pressure, the sensor is configured to detect the reaction force of the silicon wafer W to the fluid, and the pressurizing unit is configured to be able to control the pressure at which the fluid is ejected from the through-hole T based on the detection result of the sensor so that each hydrostatic block always applies a constant hydrostatic pressure to the surface of the silicon wafer W in the target plane C.

[0037] After the silicon wafer W completes the polishing process by the hydrostatic pad 10, the silicon wafer W is loaded into the material by being held between mechanical arms. The mechanical arms are driven to bring the silicon wafer W closer to the hydrostatic pad 10, and the wafer is held in place by vacuum suction when it comes into contact with the hydrostatic pad 10. To avoid physical scratch defects occurring on the surface of the silicon wafer W that comes into contact with the hydrostatic pad 10 due to scratches or friction from foreign matter, the hydrostatic pad 10 further includes a support block, which is used to protrude from the fixed plane A and contact the silicon wafer W when the silicon wafer W comes into contact with the hydrostatic pad 10. The support block is provided on the side of the base 11 closer to the silicon wafer W, i.e., on the fixed plane A, and the support block is expandable and contractible along the central axis direction by the drive module. When the plurality of hydrostatic blocks 12 hold the silicon wafer W, the support block contracts into the base 11, avoiding affecting the fluid stability for fixing the position of the plurality of hydrostatic blocks 12 and reducing the adhesion of residue and / or waste to the end faces of the support block.

[0038] When it is necessary to load the silicon wafer W, the support block extends and protrudes from the fixed plane A of the base 11 to contact the silicon wafer W. To ensure that the support block can contact the silicon wafer W before the plurality of hydrostatic blocks 12, the support block is configured such that, with respect to the fixed plane A, the height to which the support block protrudes from the fixed plane A is greater than the height to which any of the hydrostatic blocks 12 protrudes from the fixed plane A.

[0039] To further enhance the contact stability between the support block and the silicon wafer W, a vacuum device is connected to one end of the support block away from the silicon wafer W, and a plurality of suction holes are provided at the other end of the support block closer to the silicon wafer W, and the support block adsorbs the silicon wafer W through the suction holes using a vacuum suction method.

[0040] Optionally, one end of the support block closest to the silicon wafer W is made of rubber or another flexible material, or is wrapped in such material, thereby further avoiding scratching the surface of the silicon wafer W.

[0041] An embodiment of the present disclosure discloses a hydrostatic pad 10. The hydrostatic pad 10 comprises a base 11, a plurality of hydrostatic blocks 12, and a drive module, wherein each of the plurality of hydrostatic blocks 12 has a through hole T at the end of the hydrostatic block closest to the silicon wafer W, the through hole T is used to allow fluid to flow out and support the silicon wafer W in a non-contact manner, the drive module comprises a drive unit for driving the movement of each drive hydrostatic block, each hydrostatic block can move closer to or away from the silicon wafer W by the drive unit, and the hydrostatic pad 10 further comprises a sensor and a controller, which detect when the silicon wafer W is tilted for desired or undesirable reasons In this case, the target plane C in which the silicon wafer W is located in space is characterized by a change, the sensor is used to detect the change occurring in the silicon wafer W and to obtain the new spatial position of the target plane C, the controller transmits a control signal to the drive module based on the new spatial position of the target plane C, and the drive module drives the plurality of hydrostatic blocks 12 to move horizontally in accordance with the control signal until the first plane B formed by the ends of each hydrostatic block and the target plane C in which the silicon wafer W is located after tilting become parallel.

[0042] The above-described hydrostatic pad 10 allows for real-time adjustment of the distance between the hydrostatic pad 10 and the silicon wafer W, ensuring that the hydrostatic pad 10 and the silicon wafer W are always parallel, thereby ensuring stability during the polishing process and improving product quality. When using the above-described hydrostatic pad 10, hydrostatic pads 10 are also provided on different sides of the silicon wafer W to provide fluid hydrostatic pressure and support the silicon wafer W. The adjustment principle of the hydrostatic pads 10 located on both sides of the silicon wafer W is the same, and the resulting technical effect is that the hydrostatic pad 10 and the silicon wafer W are both able to be parallel.

[0043] Based on the hydrostatic pad 10 described above, embodiments of the present disclosure further provide a polishing apparatus configured to polish both sides of a silicon wafer W, and the polishing apparatus includes a holding member, a pair of grinding plates, and a pair of the hydrostatic pads 10. The holding member is used to hold the silicon wafer W along the vertical direction, the pair of grinding plates are provided symmetrically on both sides of the silicon wafer W with respect to the holding member, and the pair of hydrostatic pads 10 are provided symmetrically on both sides of the silicon wafer W with respect to the holding member. Specifically, as shown in Figure 4, the outer shape of the hydrostatic pad 10 is crescent-shaped, which is for positioning the polishing plate in a circular defect area in a double-sided polishing apparatus for silicon wafer W. The pair of polishing plates rotate around a common axis of rotation to polish the two main surfaces of the silicon wafer W, which is held by the holding member and supported by the pair of hydrostatic pads 10. The polishing plates can be retracted into the circular defect area of ​​the polishing pad when not polishing the silicon wafer W.

[0044] Based on the polishing apparatus described above, the embodiments of this disclosure further provide a silicon wafer W, the silicon wafer W being obtained using the polishing apparatus described above.

[0045] Furthermore, the technical solutions described in the embodiments of this disclosure can be combined in any way if there are no conflicts.

[0046] The foregoing describes only the specific methods of implementing this disclosure, but the scope of protection of this disclosure is not limited thereto. Any modifications or substitutions that a person skilled in the art could easily conceive within the technical scope disclosed herein should be included in the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be based on the scope of protection of the claims.

[0047] (Cross-reference of related applications) This disclosure claims priority under Chinese Patent Application No. 202310340170.3, submitted to China on March 31, 2023, and all its contents are incorporated herein by reference.

Claims

1. It is a static pressure pad, The aforementioned static pressure pads are configured to form a pair in a double-sided polishing apparatus for silicon wafers and clamp both sides of the silicon wafer. The aforementioned static pressure pad is A base having a fixed plane facing the silicon wafer, Multiple static pressure blocks are uniformly distributed vertically along the fixed plane and protrude from the fixed plane, Includes a drive module, The plurality of static pressure blocks provide static pressure to the silicon wafer via a fluid to support one side of the silicon wafer in a non-contact manner. The drive module is configured to drive each hydrostatic pad so that, when the first plane formed by the ends of each hydrostatic block is not parallel to the target plane on which the silicon wafer is located, the first hydrostatic block is moved along a direction perpendicular to the fixed plane so that the first plane and the target plane become parallel.

2. The hydrostatic pad further includes a support block provided on the fixed plane, the support block moves along a direction perpendicular to the fixed plane and protrudes from the fixed plane, and the support block is configured such that the protruding height of the support block relative to the fixed plane is greater than the protruding height of any of the plurality of hydrostatic blocks relative to the fixed plane. The static pressure pad according to claim 1, wherein a plurality of adsorption holes are provided at the end of the support block, and the adsorption holes adsorb the silicon wafer by vacuum.

3. The hydrostatic pad according to claim 1, further comprising a sensor and a controller, wherein the sensor is configured to detect the spatial position of the target plane, the controller transmits a control signal to the drive module based on the spatial position of the target plane, and the drive module drives the movement of the plurality of hydrostatic blocks based on the control signal so that the first plane and the target plane are parallel.

4. The static pressure pad according to claim 3, wherein the sensor is a pressure sensor, and the pressure sensor is configured to detect a change in the static pressure acting on the silicon wafer and to obtain the spatial orientation of the silicon wafer.

5. The static pressure pad according to claim 3, wherein the sensor is a distance sensor, and the distance sensor is configured to detect the distance between the silicon wafer and the first plane and to obtain the spatial orientation of the silicon wafer.

6. The static pressure pad according to claim 1, wherein each static pressure block has a plurality of through holes at its end, and the through holes are configured to allow the fluid to flow out and support the silicon wafer in a non-contact manner.

7. The static pressure pad according to claim 1, wherein the drive module includes a hydraulic drive unit or a pneumatic drive unit for driving the movement of the static pressure block.

8. A polishing device, The polishing apparatus is configured to polish both sides of a silicon wafer. The polishing apparatus is A holding member for holding the silicon wafer along the vertical direction, Two grinding machines are provided symmetrically with respect to the aforementioned holding member, A polishing apparatus comprising two static pressure pads according to any one of claims 1 to 7, provided symmetrically with respect to the holding member.

Images