Wafer chemical mechanical polishing equipment and method

Abstract

The invention relates to wafer chemical mechanical polishing equipment and a wafer chemical mechanical polishing method. The wafer chemical mechanical polishing equipment comprises a transmission layer; the polishing layer is stacked on the transmission layer and is provided with a first polishing unit, a second polishing unit and a detachable third polishing unit; the cleaning layer is stacked on the polishing layer and used for cleaning the polished wafer, and the cleaning layer is provided with a cross-layer manipulator; the transmission layer is used for transmitting a wafer to be polished to the polishing layer, and the wafer polished by any polishing unit does not enter the transmission layer so as to avoid polluting the transmission layer; the cross-layer mechanical arm can extend to the polishing layer so as to be used for wafer transfer among the polishing units and is further used for transferring the wafers polished on the polishing layer to the cleaning layer, and the cross-layer mechanical arm rotates the wafers to be in a vertical state before carrying the wafers into the cleaning layer so that liquid on the wafers can drop.

Description

Technical Field

[0001] This application relates to the field of semiconductor wafer processing technology, specifically to a wafer chemical mechanical polishing equipment and method. Background Technology

[0002] In the production process of large-scale integrated circuits, the flatness requirements for wafers are extremely high. Currently, wafer flattening is achieved by using chemical mechanical polishing (CMP) technology, and CMP equipment is the main equipment for wafer flattening.

[0003] However, existing CMP equipment typically arranges its polishing and cleaning units on the same horizontal plane, resulting in a large overall footprint. In semiconductor manufacturing plants (Fabs), cleanroom costs are extremely high, and the equipment footprint directly impacts capacity layout and output per unit area. The limited number of existing CMP equipment units restricts economic efficiency. Furthermore, existing CMP equipment is usually designed for specific processes (such as single-pad, dual-pad, or triple-pad polishing), making it difficult to flexibly accommodate different process requirements within the same equipment architecture. When customers need to upgrade processes or change production flows due to wafer planarization requirements, equipment replacement or large-scale modifications are often necessary, leading to high equipment lifecycle costs. In addition, with increasingly stringent wafer planarization requirements, contamination issues during wafer chemical mechanical polishing are attracting growing attention. Splashing of polishing slurry and debris can cause surface contamination or scratches, affecting polishing accuracy and quality. Summary of the Invention

[0004] This application provides a wafer chemical mechanical polishing apparatus and method to solve or alleviate at least some of the problems mentioned above.

[0005] According to one aspect of this application, a wafer chemical mechanical polishing apparatus is provided, comprising:

[0006] Transport layer;

[0007] A polishing layer stacked on the transport layer is provided with a first polishing unit, a second polishing unit and a removable third polishing unit;

[0008] A cleaning layer stacked on the polishing layer is used to clean the polished wafer. The cleaning layer is equipped with a cross-layer robot.

[0009] The transport layer is used to transport the wafer to be polished to the polishing layer. The wafer polished by any polishing unit will not enter the transport layer again to avoid contaminating the transport layer and to avoid cross-contamination between polishing units.

[0010] The cross-layer robot can extend to the polishing layer for wafer transfer between polishing units, and also for transferring wafers polished in the polishing layer to the cleaning layer. Before carrying the wafer into the cleaning layer, the cross-layer robot rotates the wafer into a vertical position so that liquid on the wafer drips off.

[0011] Optionally, the cross-layer robot is configured such that, during the process of transferring the polished wafer from the polishing layer to the cleaning layer, the wafer is kept in a vertical position for a longer period than it is kept in a horizontal position.

[0012] Optionally, the multi-layer robotic arm includes a holding hand for gripping a wafer and an arm connected to the holding hand. The arm includes a multi-segment arm that is rotatably connected. The holding hand grips the wafer horizontally from any polishing unit. When the wafer is rotated to a vertical position, the arm is positioned above the holding hand to prevent polishing fluid dripping from the wafer from contaminating the arm.

[0013] Optionally, the bearing head of the polishing unit places the polished wafer horizontally on the loading mechanism. The loading mechanism is equipped with an upward-spraying rinsing nozzle to rinse the wafer. The cross-layer robot is configured such that: after rinsing the polished wafer in the loading mechanism of one polishing unit for a first preset time, the cross-layer robot horizontally clamps the wafer, vertically lifts the wafer, and flips the wafer so that the loading mechanism rinses the other side of the wafer. After a second preset time, the loading mechanism stops spraying liquid, the cross-layer robot rotates the wafer to a vertical position so that the liquid on the wafer surface drips off, and then horizontally transfers the wafer to the loading mechanism of another polishing unit.

[0014] Optionally, the bottom plate of the cleaning layer has an opening through which the cross-layer robot extends downward to the polishing layer. The opening is provided with a dynamic sealing device based on the wafer state to reduce cross-contamination between the polishing layer and the cleaning layer.

[0015] Optionally, the dynamic sealing device includes:

[0016] A gas sealer, positioned along the opening, is used to horizontally blow air to form a gas seal when the wafer does not pass through the opening;

[0017] The liquid sealer is disposed around the opening on the bottom surface of the base plate and includes two sets of retractable liquid seal plates symmetrically disposed about the vertical plane in which the wafer passes through the opening;

[0018] Two sets of liquid seal plates unfold downwards and spray liquid relative to each other after the wafer is rotated into a vertical position, so as to form a liquid seal between the polishing layer and the cleaning layer and rinse and moisturize the wafer passing through it, and retract when the cross-layer robot is not holding the wafer or the wafer is not vertical, so as to avoid interference.

[0019] Optionally, the inner walls of the two sets of liquid seal plates are provided with multiple liquid nozzles to spray liquid downwards at an angle; in the upper half of the inner wall of the liquid seal plate, the liquid nozzles are configured to spray liquid at an angle greater than or equal to 20 degrees and less than or equal to 45 degrees with the horizontal plane to reduce liquid splashing onto the cleaning layer; in the lower half of the inner wall of the liquid seal plate, the liquid nozzles are configured to spray liquid at an angle greater than 0 degrees and less than 20 degrees with the horizontal plane to provide a greater rinsing intensity compared to the upper half.

[0020] Optionally, when the two sets of liquid seal plates unfold, they form a curved surface that gradually tapers downward from the base plate, with a gap at the lower end to facilitate downward flow. When the horizontal diameter of the wafer has not yet entered the two sets of liquid seal plates, the length of the gap is greater than the wafer diameter, and the width is greater than the thickness of the holding hand of the cross-layer manipulator holding the wafer, so as to allow the wafer to pass vertically. After the horizontal diameter of the wafer enters the two sets of liquid seal plates, the liquid seal plates extend further downward and the size of the gap gradually shrinks. The extension speed of the liquid seal plates matches the rising speed of the wafer to avoid interfering with the wafer.

[0021] Optionally, the wafer chemical mechanical polishing equipment includes two cross-layer manipulators symmetrically arranged about its cross-section. The two cross-layer manipulators are arranged in parallel paths as they carry the wafer vertically through the opening. The two sets of liquid seals are shaped such that the curved surfaces formed when they are unfolded gradually contract, allowing either cross-layer manipulator to carry the wafer vertically through the opening.

[0022] Optionally, each set of liquid seal sheets has two independently controlled spray sections corresponding to the paths of two cross-layer robots carrying wafers vertically through the opening. When one cross-layer robot carries a wafer through the liquid seal sheet, the corresponding spray section sprays liquid onto the wafer at a first flow rate to rinse and moisturize it, while the other spray section sprays liquid at a second flow rate lower than the first flow rate to form a moisturizing liquid film on the inner wall of the liquid seal sheet to prevent contaminant crystallization.

[0023] Optionally, the gas seal includes a gas generator and a gas recoverer disposed opposite to each other; the gas generator includes multiple electrically actuated blades and multiple beam nozzles disposed on the side of the multiple blades facing the gas recoverer.

[0024] Multiple fan blades are arranged horizontally at intervals and can swing to generate turbulent airflow; the beam nozzles extend horizontally, opening toward the fan blades and gradually contracting away from the fan blades to integrate the turbulent airflow into a uniform horizontal airflow.

[0025] Optionally, the first polishing unit, the second polishing unit, and the third polishing unit each include two polishing tables, two loading mechanisms, an annular support track disposed above the polishing tables, and one or more bearing heads; the first polishing unit and the second polishing unit are symmetrically arranged about the mid-section of the wafer chemical mechanical polishing equipment, and the two polishing tables of each unit are longitudinally arranged side by side, one for rough polishing of wafers and the other for fine polishing of wafers; the third polishing unit is laterally disposed downstream of the first and second polishing discs.

[0026] In each polishing unit, one or more carrier heads are suspended from and movable along a support rail to polish the wafer at the polishing table and to transfer the wafer between the polishing table and the loading mechanism.

[0027] Optionally, chemical mechanical polishing (CMP) equipment can be configured to achieve polishing with nanometer-level and smaller precision for polishing wafers used to manufacture logic chips; and

[0028] Chemical mechanical polishing (CMP) equipment can be configured with multiple polishing routes to perform rough and fine polishing to improve polishing efficiency for polishing wafers used in the manufacture of memory chips.

[0029] Optionally, when the wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing logic chips, the two polishing stages of the third polishing unit are configured to both be used for ultra-fine polishing of the wafers to form two parallel polishing paths with the first polishing unit and the second polishing unit. In each polishing path, the wafers are rough polished, fine polished, and ultra-fine polished by passing through the two polishing stages of the first polishing unit or the second polishing unit and one polishing stage of the third polishing unit, respectively.

[0030] Optionally, when the wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing logic chips, in each polishing unit, the support track is configured to suspend two carrier heads, each carrier head dedicated to a polishing stage, to avoid uneven wafer polishing caused by the cross-use of carrier heads and polishing stages.

[0031] Optionally, when the wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing memory chips, the two polishing stations of the third polishing unit are configured as one for rough polishing of the wafer and the other for fine polishing of the wafer. The first polishing unit, the second polishing unit and the third polishing unit each form a polishing path, and the wafer is rough polished and fine polished in each polishing path.

[0032] Optionally, when the wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing memory chips, in each polishing unit, the support track is configured to suspend three or four carrier heads, which can be used alternately between two polishing tables and two loading mechanisms to reduce the idle time of the polishing tables.

[0033] Optionally, the wafer chemical mechanical polishing equipment may include a pre-cleaning module located downstream of the first and second polishing units after the third polishing unit is removed. The pre-cleaning module includes an adsorption stage configured to vacuum adsorb wafers and a polishing cleaning head disposed above the adsorption stage. The polishing cleaning head is configured with a polishing cleaning pad facing the adsorption stage. The adsorption stage adsorbs and fixes the wafer with the surface of the wafer polished by the first or second polishing unit facing the polishing cleaning head. The polishing cleaning pad is configured to press against the wafer and remove residual abrasive particles from the wafer surface. The polishing liquid released onto the polishing pad on the polishing stage during wafer rough polishing or fine polishing contains the abrasive particles.

[0034] The pre-cleaning module forms two parallel polishing routes with the first polishing unit and the second polishing unit. In each polishing route, the wafer undergoes rough polishing, fine polishing, and polishing cleaning by passing through the two polishing tables of the first polishing unit or the second polishing unit and the pre-cleaning module, respectively.

[0035] According to another aspect of this application, a wafer chemical mechanical polishing method is provided, which is performed using the wafer chemical mechanical polishing equipment described in the foregoing aspects.

[0036] According to the wafer chemical mechanical polishing (CMP) equipment and method of this application, through the layered arrangement of the transport layer and polishing layer and the unidirectional transfer from the transport layer to the polishing layer, once the wafer enters the polishing layer, after being polished by any polishing unit, it does not return to the transport layer for transfer again. Instead, a cross-layer robot extending to the polishing layer is used to transfer the wafer between polishing units. Therefore, polishing slurry and polishing debris adhering to the wafer surface due to polishing are not transferred to the transport layer with the wafer, reducing contamination within the transport layer space. This reduces the risk of the wafer being contaminated during subsequent polishing processes and also reduces contamination of the polishing unit itself by contaminants carried by the wafer from other polishing units, thus reducing cross-contamination between polishing units. Furthermore, the cross-layer robot is configured to rotate the wafer into a vertical position before carrying it into the cleaning layer, reducing the accumulation of polishing slurry on the wafer surface and allowing the slurry to drip off, ensuring the wafer enters the cleaning layer in a well-pre-cleaned state. This reduces the workload of the cleaning layer and improves the wafer cleaning effect. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0038] Figure 1This is a perspective view of a wafer chemical mechanical polishing apparatus according to one embodiment of this application;

[0039] Figure 2 for Figure 1 A three-dimensional cross-sectional view of the wafer chemical mechanical polishing equipment shown.

[0040] Figure 3 It shows Figure 1 A top view of the polished layer in the middle;

[0041] Figure 4 It shows Figure 3 A three-dimensional view of any polishing unit in the image;

[0042] Figure 5 It shows Figure 1 A top view of the cleaning layer in the middle;

[0043] Figure 6 for Figure 1 The diagram shows the wafer transport path during wafer polishing in a polishing unit of a wafer chemical mechanical polishing (CMP) apparatus.

[0044] Figure 7 for Figure 1 A schematic diagram of the geometry of a polishing unit in a wafer chemical mechanical polishing (CMP) apparatus is shown.

[0045] Figure 8 It shows Figure 4 A schematic diagram of one embodiment of the loading mechanism in the diagram;

[0046] Figure 9 for Figure 1 A schematic diagram of a multi-layer robotic arm;

[0047] Figure 10 It shows Figure 1 A schematic diagram of the base plate of the cleaning layer and the polishing layer in the middle;

[0048] Figure 11 It shows Figure 10 A top view of the air sealer and the multi-level manipulator in the middle;

[0049] Figure 12 It shows Figure 11 A schematic diagram of the gas generator in the gas seal device;

[0050] Figure 13 It shows Figure 11 A schematic diagram of the gas recovery unit in the gas seal device;

[0051] Figure 14 It shows Figure 1 A schematic diagram showing the liquid sealer and collector in the polished layer in an unfolded state;

[0052] Figure 15 It shows Figure 1 A schematic diagram showing the liquid sealer and collector in the polished layer in a retracted state;

[0053] Figure 16 It shows Figure 14 A magnified schematic diagram of a mid-span robotic arm vertically holding a wafer through a liquid sealer;

[0054] Figure 17 A flowchart showing the controller controlling the dynamic sealing device and the collector below it is shown. Detailed Implementation

[0055] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0056] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] In addition, in the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0058] Figure 1 This is a perspective view of a wafer chemical mechanical polishing apparatus according to one embodiment of this application; Figure 2 for Figure 1The diagram shows a three-dimensional cross-sectional view of the wafer chemical mechanical polishing (CMP) equipment. As can be seen, the equipment, in its overall architecture, comprises three parallel vertical units: a first vertical unit 1V, a second vertical unit 2V, and a third vertical unit 3V, arranged sequentially from front to back. The first vertical unit 1V includes a front unit 1 for storing wafers to be polished and those after polishing; the second vertical unit 2V includes a vertically arranged rotary cleaning module 33 and a drying module 34 (see...). Figure 2 The third vertical unit 3V can be further divided into three horizontally stacked structures, namely:

[0059] The transport layer is used to receive wafers from the front unit 1 and transfer the wafers to be polished to the polishing layer. The transport layer may be equipped with a front robot arm 11 (see...). Figure 3 , Figure 5 ), transfer module 4, horizontal transmission module 5, the horizontal transmission module 5 may include horizontal transmission guide rail 52 and clamping and moving mechanism 51;

[0060] A polishing layer stacked on the transport layer, the polishing layer including a polishing module 2, the polishing module 2 including a first polishing unit 2A, a second polishing unit 2B and a removable third polishing unit 2C; and

[0061] A cleaning layer, stacked on the polishing layer, is used to clean the polished wafer and includes a portion of cleaning unit 3. It should be understood that cleaning unit 3 is arranged in an L-shape and includes a cleaning device in the cleaning layer and a rotary cleaning module 33 and a drying module 34 in the second vertical unit 2V. By vertically arranging the rotary cleaning module 33 and the drying module 34 in the second vertical unit 2V, the impact of vibrations generated during the operation of these two modules on the operation of the polishing unit in the third vertical unit 3V can be reduced, improving the stability of the polishing unit and thus improving wafer processing accuracy.

[0062] In addition, the wafer chemical mechanical polishing equipment may also include a control layer for controlling the operation of the equipment. The control layer may be located above or below the overall structure of the three vertical units mentioned above, and may include electrical structures, gas-liquid devices, etc.

[0063] Figure 3 for Figure 1 A top view of the polishing layer of a wafer chemical mechanical polishing (CMP) device, wherein, for clarity, the bearing head 22 is shown as a gray circle. Figure 4 It shows Figure 3A perspective view of any polishing unit in the equipment. It can be seen that the first polishing unit 2A, the second polishing unit 2B, and the third polishing unit 2C each include two polishing tables 23, two loading mechanisms 6, an annular support rail 21 disposed above the polishing table 23, and one or more carrier heads 22. A humidification device 24 may also be included. In each polishing unit, one or more carrier heads 22 are suspended from and movable along the support rail 21 to carry the wafer, polish the wafer at the polishing table 23, and transfer the wafer between the polishing table 23 and the loading mechanism 6. The first polishing unit 2A and the second polishing unit 2B are symmetrically arranged about the mid-section of the wafer chemical mechanical polishing equipment. Each of their two polishing tables 23 can be used for rough polishing of wafers and fine polishing of wafers, where "mid-section" is used... Figure 1 The dashed box shown indicates a vertical plane (i.e., the XZ plane) perpendicular to the width direction of the wafer chemical mechanical polishing (CMP) equipment, passing through the midpoint of the width of the CMP equipment (the midpoint of the Y-axis dimension). For example... Figure 3 As shown, in the first polishing unit 2A and the second polishing unit 2B, the two polishing stages 23 of each are arranged at intervals along their length direction, that is, along the X direction shown in the figure. One stage located upstream (closer to the front unit 1) is used for rough polishing of the wafer, and the other stage located downstream (farther from the front unit 1) is used for fine polishing of the wafer. The third polishing unit 2C is located downstream of the first polishing unit 2A and the second polishing unit 2B, that is, on the side of the first polishing unit 2A and the second polishing unit 2B that is farthest from the front unit 1. The two polishing stages 23 of the third polishing unit 2C can be arranged along the Y direction.

[0064] Figure 5 for Figure 1The diagram shows a top view of the cleaning layer of the wafer chemical mechanical polishing (CMP) apparatus, which is stacked on top of the polishing layer. Two symmetrical sets of cleaning units 3 can exist, also symmetrical about the mid-section of the wafer CMP apparatus. According to the cleaning sequence, the cleaning unit 3 includes: a pre-cleaning module 31, a first brushing module 32A, a second brushing module 32B, a rotary cleaning module 33, and a drying module 34. The pre-cleaning module 31 and the first brushing module 32A are located on either side of the cross-layer robot 7 to accommodate wafer transfer using the cross-layer robot 7. The first cleaning robot 81 is used to transport the wafer from the first brushing module 32A to the second brushing module 32B. A cleaning buffer section 83 is provided on one side of the second brushing module 32B to buffer the wafer and serve as an intermediate transfer point from the second brushing module 32B to the rotary cleaning module 33. Specifically, the first cleaning robot 81 can transport the wafer from the second brushing module 32B to the cleaning buffer section 83, and the second cleaning robot 82 can transport the wafer from the cleaning buffer section 83 to the rotary cleaning module 33. Therefore, it is not necessary to set up a robotic arm between the second scrubbing module 32B and the rotary cleaning module 33, which shortens the overall length of the cleaning unit 3 and reduces its volume.

[0065] Back Figure 2 The dashed lines represent the wafer transport direction. Below is a brief overview of one wafer transport path in a wafer chemical mechanical polishing (CMP) system:

[0066] First, the front-end robot 11 transfers the wafer of the front-end unit 1 to the transfer clamping mechanism (not shown) of the transfer module 4.

[0067] Next, the transfer clamping mechanism rotates around the axis of the transfer clamping fixture to flip the clamped wafer toward the side where the polishing unit 2 is located, and flips the wafer to be polished so that the bearing head 22 can polish the wafer.

[0068] After the transfer clamping mechanism completes the wafer flipping, the clamping and moving mechanism of the horizontal transmission module 5 moves toward the direction of the front unit 1 until it moves to the bottom of the wafer.

[0069] Next, the transfer clamping mechanism moves downward along the vertical transfer track to place the wafer on the clamping mechanism of the horizontal transfer module 5.

[0070] Next, the clamping and moving mechanism moves along the horizontal transfer guide to the polishing interaction position (i.e., the loading mechanism) of the polishing unit 2; when the clamping and moving mechanism 51 moves to the polishing interaction position, the loading cup of the loading mechanism 6 is located below the clamping and moving mechanism 51, and the loading cup moves upward under the drive of the loading adapter, so that the loading cup supports the wafer on the clamping and moving mechanism 51.

[0071] Next, the carrier head 22 moves along the support track 21 to above the loading mechanism 6 with the wafer, so as to adsorb the wafer of the loading cup under the carrier head 22.

[0072] Next, the wafer-loaded carrier head 22 moves above the polishing stage 23 to perform chemical mechanical polishing on the wafer. The polishing stage 23 includes a polishing disk with a polishing pad on its surface. It is also equipped with a dressing device, a liquid supply device, and a rinsing device. The dressing device is responsible for dressing the surface of the polishing pad to maintain its polishing properties. The liquid supply device has a fixed base on the outer periphery of the polishing disk, and its supply arm can swing above the polishing pad to supply polishing fluid between the polishing pad and the wafer. The rinsing device has a similar structure to the liquid supply device; it is mainly responsible for rinsing contaminants from the surface of the polishing pad and can also adjust the temperature of the polishing pad surface to adjust the material removal rate on the wafer surface.

[0073] After the carrier head 22 finishes polishing on one of the polishing stages 23, it moves along the support track 21 to the holding position. The moisturizing device 24 is usually equipped with a rinsing nozzle to spray chemical liquid and / or deionized water toward the wafer surface and the bottom of the carrier head 22 to clean the wafer surface and moisturize it.

[0074] After the wafer loaded on the carrier head 22 has completed cleaning and moisturizing, the wafer loaded on the carrier head 22 is moved to another polishing stage 23 to continue chemical mechanical polishing on the other polishing stage.

[0075] After the wafer has completed the polishing operation on the two polishing stages 23, the carrier head 22 moves to the polishing interaction position close to the cross-layer robot 7 to unload the polished wafer onto the loading cup of the loading mechanism 6.

[0076] Next, the cross-layer robot 7 transfers the wafer from the loading mechanism 6 to the pre-cleaning module 31 of the cleaning unit 3 to complete the pre-cleaning of the wafer;

[0077] After the wafer in the pre-cleaning module 31 has finished cleaning, the cross-layer robot 7 transfers the wafer to the first brushing module 32A to complete the brushing of the wafer surface.

[0078] After the wafer completes the first step of brushing, the first cleaning robot 81 transfers the wafer in the first brushing module 32A to the second brushing module 32B to continue brushing the wafer surface.

[0079] After the wafer in the second washing module 32B has finished washing, the first cleaning robot 81 will transfer the wafer to the cleaning buffer section 83.

[0080] Next, the second cleaning robot 82 transfers the wafer from the cleaning buffer section 83 to the rotary cleaning module 33. The second cleaning robot 82 is equipped with a vertical guide rail, which can move vertically to transfer the wafer that has completed rotary cleaning to the drying module 34.

[0081] Finally, the front-end robotic arm 11 transfers the dried wafer to the front-end unit 1, thereby completing the "dry-in, dry-out" process of the wafer and obtaining a wafer that meets the process requirements.

[0082] The technical solution of this application enables the modularization and flexible adjustment of wafer CMP equipment, facilitating adaptation to different wafer processing types and processing route requirements. For example, this wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing logic chips and wafers used for manufacturing memory chips, or to polish other types of wafers. Wafers used for manufacturing logic chips require uniformity with nanometer-level or even smaller precision (approaching atomic level) after polishing, thus requiring high stability during the polishing process, including the stability of the carrier head movement and the consistency of the polishing contact state between the carrier head and the polishing stage. Wafers used for manufacturing memory chips typically require high polishing efficiency.

[0083] When the wafer chemical mechanical polishing (CMP) equipment is configured to polish wafers used for manufacturing logic chips, the two polishing stages 23 of the third polishing unit 2C are configured to both be used for ultra-fine polishing of the wafers, forming two parallel polishing paths with the first polishing unit 2A and the second polishing unit 2B. In each polishing path, the wafer undergoes rough polishing, fine polishing, and ultra-fine polishing respectively through the two polishing stages 23 of the first polishing unit 2A or the second polishing unit 2B and one polishing stage 23 of the third polishing unit 2C. Furthermore, in a preferred embodiment, in each polishing unit, the support rail 21 can be configured to suspend two carrier heads 22, each carrier head 22 dedicated to one polishing stage 23. That is, a one-to-one correspondence between the carrier head 22 and the polishing stage 23 is established to avoid uneven wafer polishing caused by inconsistent polishing contact states between the carrier head 22 and the polishing stage 23 due to cross-use of the carrier head 22 and the polishing stage 23.

[0084] like Figure 6 This diagram illustrates a wafer transport process within a polishing unit (e.g., the second polishing unit 2B). Figure 6 (a) The No. 1 bearing head 22 takes a piece from the loading mechanism 6 on the left, while the No. 2 bearing head 22 is unloaded; Figure 6 (b) The No. 1 carrier head 22 carries the wafer to the P1 polishing stage 23 for rough polishing, while the No. 2 carrier head 22 is unloaded; Figure 6 (c) The No. 1 carrier head 22 moves the rough polished wafer to the loading mechanism 6 on the right, while the No. 2 carrier head 22 is unloaded; Figure 6(d) The No. 1 carrier head 22 moves to the left loading mechanism to pick up the wafer, and the No. 2 carrier head 22 moves to the right loading mechanism to pick up the rough polished wafer; Figure 6 (e) The No. 1 carrier head 22 carries the wafer to be polished, and the No. 2 carrier head 22 moves to the P2 polishing stage 23 for fine polishing of the wafer; Figure 6 (f) Carrying head 1 22 carries the wafer to polishing stage P1 23 for rough polishing, while carrying head 22 22 places the finely polished wafer at the loading mechanism on the right for delivery out of the polishing unit. Alternatively, when a high degree of one-to-one correspondence between carrying heads 22 and polishing stages 23 is required during wafer polishing, both polishing stages 23 of the first polishing unit 2A and the second polishing unit 2B can be configured for rough polishing, ensuring a one-to-one correspondence between the two carrying heads 22 and the two polishing stages 23. In this case, the two carrying heads 22 can carry two wafers simultaneously for rough polishing, avoiding one carrying head 22 waiting. In this scenario, the third polishing unit 2C is configured for two fine polishing stages. It should be understood that carrying head 3 in the diagram can be suspended on a support rail for load balancing, or it can be omitted.

[0085] When the wafer chemical mechanical polishing (CMP) equipment is configured to polish wafers used for manufacturing memory chips, the two polishing stages 23 of the third polishing unit 2C are configured such that one is used for rough polishing of the wafer and the other for fine polishing. The first polishing unit 2A, the second polishing unit 2B, and the third polishing unit 2C each form a polishing path, for a total of three polishing paths. The wafer undergoes both rough and fine polishing in each polishing path. Furthermore, in each polishing unit, the support rail 21 is configured to suspend three or four carrier heads 22. The three or four carrier heads 22 can be used alternately between the two polishing stages 23 and the two loading mechanisms 6 to reduce the idle time of the polishing stages 23 and improve polishing efficiency.

[0086] In an alternative embodiment, the wafer chemical mechanical polishing equipment can also have the following different modular configurations depending on the processing requirements:

[0087] For example, in cases where the precision requirements for wafer polishing are extremely high, the two polishing stations 23 of the third polishing unit 2C are configured such that one is used for first-stage ultra-fine polishing of the wafer and the other is used for second-stage ultra-fine polishing of the wafer; one of the first polishing unit 2A and the second polishing unit 2B, together with the third polishing unit 2C, form a polishing route that sequentially performs rough polishing, fine polishing, first-stage ultra-fine polishing of the wafer, and second-stage ultra-fine polishing, thereby achieving higher precision wafer polishing.

[0088] In another embodiment, the wafer chemical mechanical polishing (CMP) apparatus may include a pre-cleaning module 31 located downstream of the first polishing unit 2A and the second polishing unit 2B after the third polishing unit 2C has been removed. The pre-cleaning module 31 includes an adsorption stage configured to vacuum-adsorb the wafer and a polishing cleaning head positioned above the adsorption stage. The polishing cleaning head has a polishing cleaning pad facing the adsorption stage. The adsorption stage adsorbs and fixes the wafer with the surface polished by the first polishing unit 2A or the second polishing unit 2B facing the polishing cleaning head. The polishing cleaning pad is configured to press against the wafer and remove residual abrasive particles from the wafer surface. The polishing fluid released onto the polishing pad on the polishing stage 23 during rough or fine polishing contains abrasive particles. The pre-cleaning module 31 forms two parallel polishing paths with the first polishing unit 2A and the second polishing unit 2B. In each polishing path, the wafer passes through the two polishing stages 23 of the first polishing unit 2A or the second polishing unit 2B and the pre-cleaning module 31 for rough polishing, fine polishing, and polishing cleaning, respectively. The pre-cleaning module 31 may be a pre-cleaning module 31 in an upper cleaning unit 3 that has been moved from the upper layer to the lower layer. In an optional embodiment, the third polishing unit 2C may not be removed. Instead, the polishing pad of the polishing table 23 of the third polishing unit 2C may be adjusted to be softer, and the downward pressure of the bearing head 22 may be reduced, thereby allowing the third polishing unit 2C to be used for polishing and cleaning. This polishing and cleaning process can effectively remove abrasive particles, including cerium dioxide.

[0089] In another embodiment, the two polishing stations 23 of the third polishing unit 2C are configured such that one is used for rough polishing of the wafer and the other is used for fine polishing of the wafer. The wafer chemical mechanical polishing equipment includes two symmetrically arranged third polishing units 2C. The two third polishing units 2C are respectively located downstream of the first polishing unit 2A and the second polishing unit 2B. The first polishing unit 2A, the second polishing unit 2B and the two third polishing units 2C together form four parallel polishing routes including rough polishing and fine polishing.

[0090] Regarding the specific setup of the polishing unit, the geometric position and movement of each structure within the polishing unit can be more precisely defined based on the overall size requirements of the equipment and the requirements for polishing stability.

[0091] like Figure 3In each polishing unit, two polishing tables 23 are spaced apart along the length of the polishing unit, and a support rail 21 is centered about the two polishing tables 23 along the length of the polishing unit. The first polishing unit 2A and the second polishing unit 2B are configured such that their lengths are aligned with the length of the wafer chemical mechanical polishing (CMP) equipment, and the third polishing unit 2C is configured such that its length is perpendicular to the length of the wafer CMP equipment. The centers of the support rails 21 of the first polishing unit 2A, the second polishing unit 2B, and the third polishing unit 2C form an isosceles triangle (e.g., ...). Figure 3 (As shown by the dashed line in the middle), the vertex angle of the isosceles triangle is set, for example, between 30° and 60°. The vertex angle and side length of the isosceles triangle can be adjusted according to the size design requirements of the wafer chemical mechanical polishing equipment, such as the length and width configuration of the factory, in order to optimize the internal structural layout of the wafer chemical mechanical polishing equipment and achieve the best arrangement in the factory.

[0092] In each polishing unit, two loading mechanisms 6 are spaced apart along the length of the polishing unit and are positioned on one side of the two polishing stages 23 facing the mid-section. The line connecting the centers of the two loading mechanisms 6 and the two polishing stages 23 forms an isosceles trapezoid, with the line connecting the centers of the two loading mechanisms 6 forming the shorter side of the isosceles trapezoid. Near the longer side of the isosceles trapezoid, between the two polishing stages 23, a moisturizing device 24 can be provided to clean and moisturize the wafer on the carrier head 22 while it is waiting.

[0093] like Figure 7 As shown, the double-dotted line in the figure represents the movement path of the carrier head 22 along the support track 21. In each polishing unit, the carrier head 22 carries the wafer for polishing on the polishing pad of the polishing table 23. The carrier head 22 is configured to rotate and reciprocate along the support track 21 to oscillate relative to the polishing pad. Figure 7 The dashed circle in the diagram represents the swing range of the bearing head 22. The path of the bearing head 22 reciprocating along the support rail 21 is the line connecting the center of the support rail 21 and the center of the polishing table 23. Figure 7 The dotted lines in the diagram are roughly symmetrical to make the polishing range more symmetrical and improve polishing uniformity. The maximum swing angle v of the bearing head 22 is 40° to 70°. Alternatively, the path of the bearing head 22 reciprocating along the support rail 21 is more biased towards the support rail 21 in the Y direction by the line connecting the center of the support rail 21 and the center of the polishing table 23, so that the weight of the two bearing heads 22 is more evenly distributed on the support rail 21 and the stability of the support rail 21 is improved.

[0094] When the two support heads 22 polish the wafer on the two polishing tables 23 respectively, the centers of the two support heads 22 form an angle between 90° and 180° with the line connecting the center of the support track 21. Preferably, during polishing, the two support heads 22 move asynchronously towards or away from the loading mechanism, that is, in the width direction (Y direction), the two support heads 22 move asynchronously towards or away from the center of the wafer chemical mechanical polishing equipment. This avoids the two support heads 22 converging towards one side at the same time, which would cause the support track 21 to tilt or oscillate, affecting the stability of the polishing process and reducing the polishing accuracy.

[0095] On the other hand, in the layered structure of this application, interlayer and intralayer cross-contamination is also a significant factor affecting wafer processing accuracy and quality. To address this, the wafer chemical mechanical polishing (CMP) equipment of this application is configured such that the transport layer only transports wafers to be polished within its own layer and unidirectionally supplies wafers to be polished to the polishing layer. Once a wafer enters the polishing layer, after being polished by any polishing unit, it does not return to the transport layer for further transport. Instead, a cross-layer manipulator 7 extending to the polishing layer is used for wafer transport between polishing units. Wafer transport between two polishing stages within each polishing unit is performed by a moving carrier head 22 and a loading mechanism 6. Thus, polishing fluid and polishing debris adhering to the wafer surface due to polishing are not transferred to the transport layer along with the wafer, reducing contamination within the transport layer space. This reduces contamination of the wafer transported through the transport layer, thus minimizing its impact on subsequent polishing processes, i.e., reducing interlayer contamination between the transport layer and the polishing layer. Furthermore, it reduces contaminants carried by the wafer from other polishing units from the wafer itself, i.e., reducing cross-contamination between polishing units.

[0096] In one polishing unit, the carrier head 22 picks up the wafer to be polished from the loading mechanism 6 and carries the wafer to the polishing table 23 for polishing. After polishing, the carrier head 22 horizontally unloads the wafer onto the loading mechanism 6. Then, the cross-layer robot 7 picks up the wafer from the loading mechanism 6 to transfer it to the loading mechanism 6 of another polishing unit, so that the carrier head 22 of the other polishing unit can pick up the wafer for the next polishing process. Figure 8A schematic diagram of a loading mechanism 6 is shown, which is equipped with an upward-spraying rinsing nozzle 61 (specifically disposed in a cup-shaped loading cup of the loading mechanism 6) to rinse the wafer placed therein. When the cross-layer robot 7 is used for wafer transfer between polishing units, it is configured as follows: after rinsing the polished wafer in the loading mechanism 6 of one polishing unit for a first preset time, the cross-layer robot horizontally picks up the wafer from the loading mechanism 6, vertically lifts the wafer, and flips the wafer so that the loading mechanism rinses the other side of the wafer. After a second preset time, the loading mechanism 6 stops spraying liquid, the cross-layer robot 7 rotates the wafer to a vertical position so that the liquid on the wafer surface drips off, and then horizontally transfers the wafer to the loading mechanism 6 of another polishing unit. Therefore, through the effective cooperation of the flipping function of the cross-layer robot 7 and the rinsing function of the loading mechanism 6, the polished wafers can be rinsed on both sides, and the rinsing residue can be fully dripped off before the wafers are transferred to another polishing unit. This reduces the risk of contaminants adhering to the wafers while they are polished in one polishing unit being transferred to another polishing unit, reduces cross-contamination between polishing units, and reduces the dripping of rinsing residue during wafer transfer, ensuring the cleanliness of the transfer process.

[0097] The cross-layer robotic arm 7 is also configured to rotate the wafer into a vertical position before carrying it into the cleaning layer, allowing the polishing slurry on the wafer to drip off. Furthermore, during the transfer of the polished wafer from the polishing layer to the cleaning layer, the wafer is kept in a vertical position for a longer period than it is kept in a horizontal position, ensuring sufficient dripping of the slurry. Figure 9 The multi-layer robotic arm 7 includes a holding hand 71 for holding a wafer and an arm portion 72 connected to the holding hand 71. The arm portion 72 includes a multi-segment arm that is rotatably connected. The holding hand 71 horizontally grips the wafer from any polishing unit. When the wafer is rotated into a vertical position, the arm portion 72 is positioned above the holding hand 71 to prevent polishing liquid dripping from the wafer from contaminating the arm portion 72.

[0098] In a more preferred embodiment, such as Figure 10 The diagram shows the base plate of the cleaning layer and the polishing layer. A cross-layer robot 7 extends downwards through an opening 35 in the base plate of the cleaning layer to the polishing layer. To reduce cross-contamination between the polishing and cleaning layers caused by contaminants passing through this opening 35, a dynamic sealing device based on the wafer state is provided at the opening 35. This dynamic sealing device mainly includes a gas seal 91 and a liquid seal 92. Figure 11 A top view of the gas sealer 91 and the cross-layer robot 7 is shown. In the illustrated embodiment, the opening 35 is circular. The gas sealer 91 is positioned along the opening 35, for example, along the inner wall of the opening 35, to horizontally blow air to form a gas seal when the wafer does not pass through the opening 35. The dashed lines in the figure schematically show the gas seal curtain formed by the airflow. The gas seal curtain allows the cross-layer robot 7 to pass freely and perform cleaning by blowing air through it. Figure 14A schematic diagram is shown of the liquid sealer 92 in the polished layer in the deployed state. Figure 15 A schematic diagram is shown with the sealant in the polished layer in the retracted state. Figure 16 An enlarged schematic diagram shows a cross-layer robot 7 vertically holding a wafer W through a liquid sealer 92. The liquid sealer 92 is positioned around an opening 35 on the bottom surface of the cleaning layer's base plate and includes two retractable sets of liquid seal plates 921 symmetrically arranged about the vertical plane (e.g., the YZ plane perpendicular to the length direction of the device) where the wafer passes through the opening 35. The two sets of liquid seal plates 921 extend downwards and spray liquid relative to each other after the wafer is rotated into an upright position, forming a liquid seal between the polishing layer and the cleaning layer and rinsing and moisturizing the wafer passing through it. They also retract when the cross-layer robot 7 is not holding the wafer or when the wafer is not vertical to avoid interference. Multiple liquid nozzles (not shown) are distributed on the inner walls of the two sets of liquid seal plates 921 to spray liquid downwards at an angle greater than 0 degrees and less than or equal to 45 degrees with respect to the horizontal plane, thereby creating a downward rinsing force on contaminants on the wafer while simultaneously moisturizing the wafer surface to prevent contaminants from drying and crystallizing. Figure 16 The diagram illustrates the liquid flow from two opposing liquid nozzles, shown in blue dashed lines.

[0099] By setting up gas sealer 91 and liquid sealer 92, and dynamically controlling their opening and closing based on the wafer's transfer status, the polishing layer and cleaning layer can be effectively sealed and isolated. This reduces the amount of contaminants attached to the wafer that can be transferred into the cleaning layer, improving the cleanliness of the wafer transferred to the cleaning layer. This is beneficial for improving the subsequent cleaning effect of the wafer in the cleaning layer. Furthermore, the opening and closing sequence of gas sealer 91 and liquid sealer 92 can also ensure the wettability of the wafer surface, preventing contaminants on the wafer from drying and crystallizing due to air blowing by gas sealer 91, which would increase the difficulty of wafer cleaning or cause scratches on the wafer surface.

[0100] In an optional embodiment, the gas seal 91 includes a gas generator 911 and a gas recovery unit 912 disposed opposite to each other. For example... Figure 12 As shown, the gas generator 911 includes multiple electrically actuated fan blades 9111 and multiple beam nozzles 9112 disposed on the side of the fan blades 9111 facing the gas recoverer 912. The fan blades 9111 can be disposed inside the bottom plate of the cleaning layer, with only the beam nozzles 9112 exposed on the opening sidewall. The fan blades 9111 are horizontally spaced and can oscillate to generate turbulent airflow; the beam nozzles 9112 extend horizontally, opening towards the fan blades 9111 and gradually contracting away from them to integrate the turbulent airflow into a uniform horizontal airflow. The resulting air seal curtain itself has a uniform and stable airflow, providing good isolation; and the gas generator produces airflow through the fan blades 9111, eliminating the need for additional gas supply pipelines and simplifying the equipment structure. Figure 13A three-dimensional schematic diagram of a gas recovery unit 912 is shown. The gas recovery unit 912 is provided with a plurality of recovery holes 9121 that open toward the gas generator 911. The distribution of the plurality of recovery holes 9121 corresponds to the distribution of the plurality of beam nozzles 9112, in order to recover the airflow and prevent the airflow from hitting the wall of the opening 35 and returning to avoid turbulence disturbance.

[0101] Regarding the specific configuration of the liquid sealer 92, in the upper half of the inner wall of the liquid seal plate 921, the liquid nozzle is configured such that the angle between the sprayed liquid and the horizontal plane is greater than that in the lower half of the inner wall of the liquid seal plate 921. For example, in the upper half of the inner wall of the liquid seal plate 921, the liquid sprayed by the liquid nozzle forms an angle greater than or equal to 20 degrees and less than or equal to 45 degrees with the horizontal plane to reduce liquid splashing onto the cleaning layer; in the lower half of the inner wall of the liquid seal plate 921, the liquid nozzle is configured such that the sprayed liquid forms an angle greater than 0 degrees and less than 20 degrees with the horizontal plane to provide a greater rinsing intensity and better rinse the wafer surface compared to the upper half.

[0102] When the two sets of liquid seal plates 921 unfold, they form a curved surface that gradually tapers downwards from the base plate, with a gap at the lower end to facilitate downward flow and reduce liquid splashing. Before the wafer's horizontal diameter enters the two sets of liquid seal plates 921, the length of the gap is greater than the wafer diameter, and the width is greater than the thickness of the holding hand 71 of the cross-layer manipulator 7 holding the wafer, allowing the wafer to pass vertically. After the wafer's horizontal diameter enters the two sets of liquid seal plates 921, the liquid seal plates 921 extend further downwards, and the size of the gap gradually shrinks. The extension speed of the liquid seal plates 921, or the shrinkage speed of the gap, matches the rising speed of the wafer to avoid interfering with the wafer.

[0103] In an embodiment of a wafer chemical mechanical polishing (CMP) apparatus with two symmetrically arranged cross-section manipulators 7, the opening 35 may be designed to be relatively large. The paths of the two manipulators 7 carrying the wafer vertically through the opening 35 may not coincide, but rather be symmetrically offset from the cross-section and arranged parallel to each other. In this case, the shapes of the two sets of liquid seal plates 921 are also correspondingly large, configured to form gradually contracting curved surfaces when unfolded, and their gradually contracting shape allows either manipulator 7 to carry the wafer vertically through the opening 35. Preferably, each set of liquid seal plates 921 has two independently controlled parallel spray sections corresponding to the paths of the two manipulators 7 carrying the wafer vertically through the opening 35. When one manipulator 7 carries the wafer past the liquid seal plate 921, the corresponding spray section sprays liquid onto the wafer at a first flow rate for rinsing and moisturizing, while the other spray section sprays liquid at a second flow rate lower than the first flow rate to form a moisturizing liquid film on the inner wall of the liquid seal plate 921 to prevent contaminant crystallization and also reduce the amount of rinsing liquid used.

[0104] Optionally, each set of liquid seal sheets 921 may include a single sheet structure or multiple sheet structures. The contraction and expansion of the liquid seal sheets 921 can be achieved through a top-to-bottom layered nesting form, a top-to-bottom interconnected stepped form, or other stretchable structural methods. Since the polishing units are located on both sides of the curved shape of the two sets of liquid seal sheets 921, that is, the lateral gaps of the two sets of liquid seal sheets 921 after unfolding do not face the polishing units, the small amount of liquid splashing at the lateral gaps will not have a significant impact on the polishing units. To simplify the structure and reduce manufacturing costs, sealing treatment can be omitted. Of course, in a preferred embodiment, sealing strips or shielding strips can also be provided at the lateral gaps of the two sets of liquid seal sheets 921 so that the two sets of liquid seal sheets 921 leave a gap only at the lower end after unfolding.

[0105] In an optional embodiment, a temperature sensor may be provided on the holding hand 71 of the cross-layer robot 7 to monitor the temperature of the wafer in real time. The temperature sensor is communicatively connected to the liquid supply device of the liquid sealer. Based on the wafer temperature sensed by the temperature sensor, the liquid supply device of the liquid sealer adjusts the temperature of the liquid sprayed by the liquid sealer to be within ±1°C of the wafer temperature, so as to prevent stress damage to the wafer surface caused by sudden temperature changes and ensure good surface quality of the wafer.

[0106] The opening 35 can be circular, and the top of the liquid seal plate 921 can be a semi-circle matching the opening 35. The tops of the two sets of liquid seal plates 921 form a circle matching the opening 35. The gap formed at the lower end by the downward contraction of the two sets of liquid seal plates 921 can be a horizontally circular, elliptical, or roughly elongated gap. In other embodiments, in order to match the structural arrangement of each polishing unit, the opening 35 can also be set to a suitable shape such as a semi-circle or ellipse. In this case, one or both of the two sets of liquid seal plates 921 can be adapted to the shape.

[0107] In alternative implementations, such as Figure 14 , Figure 15 As shown, a collector 93 can be installed in the polishing layer, located directly below the dynamic sealing device, on the substrate at the bottom of the polishing layer. This collector collects liquid dripping from the wafer and / or the liquid sealer 92 during wafer transfer to the cleaning layer, reducing contamination of the polishing layer, especially the polishing unit. The collector can also be retractable or height-adjustable to avoid obstacles when the cross-layer robot transfers the wafer through the polishing layer. Figure 14 A schematic diagram showing the collector in its deployed state is provided. Figure 15 A schematic diagram is shown of the collector in a retracted state, whose unfolded and retracted states match those of the liquid seal.

[0108] The wafer chemical mechanical polishing equipment may also include a controller for timing control of the dynamic sealing device and / or the collector 93 below it, such as... Figure 17A flowchart showing the controller controlling the dynamic sealing device and / or the collector 93 below it is shown, including:

[0109] S1: Blow air horizontally through the air sealer 91 to form an air seal between the cleaning layer and the polishing layer;

[0110] S2: The cross-layer robot 7 extends from the cleaning layer down to the polishing layer to pick up the wafer, and the collector 93 retracts to avoid the cross-layer robot 7.

[0111] S3: After the cross-layer robotic arm grips the wafer and lifts it above collector 93, collector 93 unfolds;

[0112] S4: After the cross-layer robot rotates the wafer into a vertical position, the two sets of liquid sealing plates 921 of the liquid sealer 92 unfold downwards and spray liquid.

[0113] S5: When the upper part of the wafer exceeds the liquid sealer 92, the gas sealer 91 stops blowing air;

[0114] S6: The cross-layer robot arm carries the wafer upward until the wafer completely passes through the opening 35. Then, the liquid seal 92 retracts while the gas seal 91 blows air again, and the collector 93 discharges the collected liquid and puts it away.

[0115] This application achieves a synergistic effect through the cooperation of a gas sealer, a liquid sealer, a vertical transport mechanism for cross-layer robotic arms, and / or a collector: the gas seal provides "static isolation," remaining effective even without transport, consuming low energy, and not hindering the passage of the cross-layer robotic arm; the vertical transport combined with the liquid seal provides "dynamic cleaning and hydration," as the wafer passes vertically through the liquid sealer, its surface is washed away by the liquid flow, not only removing contaminants but also preventing them from drying and crystallizing on the wafer surface, providing an ideal pre-cleaning state for subsequent cleaning layer operations; the collector and dynamic sealer achieve "closed-loop management," effectively capturing and discharging the liquid used for the liquid seal and the liquid dripping from the wafer through the expanding collection device below, achieving controllable management of contaminated liquid and avoiding secondary contamination of the polishing layer. This not only solves the fundamental problem of interlayer sealing but also achieves pre-cleaning and hydration of the wafer, realizing the dual goals of contamination control and process quality improvement.

[0116] This application also relates to a wafer chemical mechanical polishing method using the aforementioned wafer chemical mechanical polishing equipment, which may include:

[0117] According to another aspect of this application, a wafer chemical mechanical polishing method is also provided, which is performed using the aforementioned wafer chemical mechanical polishing equipment, and includes:

[0118] The wafer to be polished is transferred to the polishing layer through the transport layer;

[0119] The wafer is polished in a polishing layer;

[0120] Transferring the wafer from the polishing layer to the cleaning layer includes performing the aforementioned steps S1-S6 to transfer the wafer from the polishing layer to the cleaning layer.

[0121] The wafer is cleaned in the cleaning layer.

[0122] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

[0123] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A wafer chemical mechanical polishing device, characterized in that, include: Transport layer; A polishing layer stacked on the transport layer is provided with a first polishing unit, a second polishing unit and a removable third polishing unit; A cleaning layer stacked on the polishing layer is used to clean the polished wafer. The cleaning layer is equipped with a cross-layer robot. The transport layer is used to transport the wafer to be polished to the polishing layer. The wafer polished by any polishing unit will not enter the transport layer again to avoid contaminating the transport layer and to avoid cross-contamination between polishing units. The cross-layer robot can extend to the polishing layer for wafer transfer between polishing units, and also for transferring wafers polished in the polishing layer to the cleaning layer. Before carrying the wafer into the cleaning layer, the cross-layer robot rotates the wafer into a vertical position so that liquid on the wafer drips off.

2. The wafer chemical mechanical polishing equipment as described in claim 1, characterized in that, The cross-layer robot is configured such that, during the process of transferring the polished wafer from the polishing layer to the cleaning layer, the wafer is kept in a vertical position for a longer period than it is kept in a horizontal position.

3. The wafer chemical mechanical polishing equipment as described in claim 1, characterized in that, The multi-layer robotic arm includes a holding hand for gripping a wafer and an arm connected to the holding hand. The arm includes a multi-segment arm that is rotatably connected. The holding hand grips the wafer horizontally from any polishing unit. When the wafer is rotated to a vertical position, the arm is positioned above the holding hand to prevent polishing fluid dripping from the wafer from contaminating the arm.

4. The wafer chemical mechanical polishing equipment according to any one of claims 1-3, characterized in that, The bearing head of the polishing unit places the polished wafer horizontally on the loading mechanism. The loading mechanism is equipped with an upward-spraying rinsing nozzle to rinse the wafer. The cross-layer robot is configured such that: after rinsing the polished wafer in the loading mechanism of one polishing unit for a first preset time, the cross-layer robot horizontally clamps the wafer, lifts it vertically, and flips it over so that the loading mechanism can rinse the other side of the wafer. After a second preset time, the loading mechanism stops spraying liquid, the cross-layer robot rotates the wafer to a vertical position so that the liquid on the wafer surface drips off, and then the wafer is horizontally transferred to the loading mechanism of another polishing unit.

5. The wafer chemical mechanical polishing equipment according to any one of claims 1-3, characterized in that, The bottom plate of the cleaning layer has an opening, through which the cross-layer robot extends downward to the polishing layer. The opening is equipped with a dynamic sealing device based on the wafer state to reduce cross-contamination between the polishing layer and the cleaning layer.

6. The wafer chemical mechanical polishing equipment as described in claim 5, characterized in that, The dynamic sealing device includes: A gas sealer, positioned along the opening, is used to horizontally blow air to form a gas seal when the wafer does not pass through the opening; A liquid sealer is provided around an opening on the bottom surface of a base plate, comprising two sets of retractable liquid seal plates symmetrically arranged about the vertical plane in which the wafer passes through the opening; Two sets of liquid seal plates unfold downwards and spray liquid relative to each other after the wafer is rotated into a vertical position, so as to form a liquid seal between the polishing layer and the cleaning layer and rinse and moisturize the wafer passing through it, and retract when the cross-layer robot is not holding the wafer or the wafer is not vertical, so as to avoid interference.

7. The wafer chemical mechanical polishing equipment as described in claim 6, characterized in that, The inner walls of the two sets of liquid seal plates are equipped with multiple liquid nozzles to spray liquid downwards at an angle. In the upper half of the inner wall of the liquid seal plate, the liquid nozzles are configured to spray liquid at an angle greater than or equal to 20 degrees and less than or equal to 45 degrees with the horizontal plane to reduce liquid splashing onto the cleaning layer. In the lower half of the inner wall of the liquid seal plate, the liquid nozzles are configured to spray liquid at an angle greater than 0 degrees and less than 20 degrees with the horizontal plane to achieve a greater rinsing intensity compared to the upper half.

8. The wafer chemical mechanical polishing equipment as described in claim 6, characterized in that, When the two sets of liquid seal plates unfold, they form a curved surface that gradually tapers downwards from the base plate, with a gap at the lower end to facilitate downward flow. Before the horizontal diameter of the wafer enters the two sets of liquid seal plates, the length of the gap is greater than the wafer diameter, and the width is greater than the thickness of the holding hand of the cross-layer manipulator holding the wafer, so as to allow the wafer to pass vertically. After the horizontal diameter of the wafer enters the two sets of liquid seal plates, the liquid seal plates extend further downwards and the size of the gap gradually shrinks. The extension speed of the liquid seal plates matches the rising speed of the wafer to avoid interfering with the wafer.

9. The wafer chemical mechanical polishing equipment as described in claim 6, characterized in that, The wafer chemical mechanical polishing equipment includes two cross-layer manipulators symmetrically arranged about its cross-section. The two cross-layer manipulators are arranged in parallel paths as they carry the wafer vertically through the opening. The two sets of liquid seals are shaped such that the curved surfaces formed when they are unfolded gradually contract, allowing either cross-layer manipulator to carry the wafer vertically through the opening.

10. The wafer chemical mechanical polishing equipment as described in claim 9, characterized in that, Each set of liquid seal sheets has two independently controlled spray sections corresponding to the paths of two cross-layer robotic arms carrying wafers vertically through the opening. When one cross-layer robotic arm carries a wafer through the liquid seal sheet, the corresponding spray section sprays liquid onto the wafer at a first flow rate to rinse and moisturize it, while the other spray section sprays liquid at a second flow rate lower than the first flow rate to form a moisturizing liquid film on the inner wall of the liquid seal sheet to prevent contaminant crystallization.

11. The wafer chemical mechanical polishing equipment as described in claim 6, characterized in that, The gas seal includes a gas generator and a gas recovery unit arranged opposite each other; the gas generator includes multiple electrically actuated blades and multiple beam nozzles located on the side of the multiple blades facing the gas recovery unit. Multiple fan blades are arranged horizontally at intervals and can swing to generate turbulent airflow; the beam nozzles extend horizontally, opening toward the fan blades and gradually contracting away from the fan blades to integrate the turbulent airflow into a uniform horizontal airflow.

12. The wafer chemical mechanical polishing apparatus according to any one of claims 1-3, characterized in that, The first polishing unit, the second polishing unit, and the third polishing unit each include two polishing tables, two loading mechanisms, an annular support track set above the polishing tables, and one or more bearing heads; the first polishing unit and the second polishing unit are symmetrically arranged about the mid-section of the wafer chemical mechanical polishing equipment, and the two polishing tables of each unit are arranged longitudinally side by side, one for rough polishing of wafers and the other for fine polishing of wafers; the third polishing unit is arranged laterally downstream of the first and second polishing discs. In each polishing unit, one or more carrier heads are suspended from and movable along a support rail to polish the wafer at the polishing table and to transfer the wafer between the polishing table and the loading mechanism.

13. The wafer chemical mechanical polishing equipment as described in claim 12, characterized in that, Chemical mechanical polishing (CMP) equipment can be configured to achieve polishing with nanometer-level and even smaller precision for polishing wafers used in the manufacture of logic chips; and Chemical mechanical polishing (CMP) equipment can be configured with multiple polishing routes to perform rough and fine polishing to improve polishing efficiency for polishing wafers used in the manufacture of memory chips.

14. The wafer chemical mechanical polishing equipment as described in claim 13, characterized in that, When a wafer chemical mechanical polishing (CMP) equipment is configured to polish wafers used for manufacturing logic chips, the two polishing stages of the third polishing unit are configured to both be used for ultra-fine polishing of the wafers, forming two parallel polishing routes with the first and second polishing units. In each polishing route, the wafers are rough polished, fine polished, and ultra-fine polished by passing through the two polishing stages of the first or second polishing unit and one polishing stage of the third polishing unit, respectively.

15. The wafer chemical mechanical polishing equipment as described in claim 13, characterized in that, When a wafer chemical mechanical polishing (CMP) machine is configured to polish wafers used for manufacturing logic chips, in each polishing unit, a support track is configured to suspend two carrier heads, each carrier head dedicated to a polishing stage, to avoid uneven wafer polishing caused by the cross-use of carrier heads and polishing stages.

16. The wafer chemical mechanical polishing equipment as described in claim 13, characterized in that, When a wafer chemical mechanical polishing (CMP) equipment is configured to polish wafers used for manufacturing memory chips, the two polishing stations of the third polishing unit are configured as one for rough polishing of the wafer and the other for fine polishing of the wafer. The first polishing unit, the second polishing unit, and the third polishing unit each form a polishing path, and the wafer undergoes rough polishing and fine polishing in each polishing path.

17. The wafer chemical mechanical polishing equipment as described in claim 13, characterized in that, When the wafer chemical mechanical polishing equipment is configured to polish wafers used for manufacturing memory chips, in each polishing unit, the support rail is configured to suspend three or four carrier heads, which can be used alternately between two polishing tables and two loading mechanisms to reduce the idle time of the polishing tables.

18. The wafer chemical mechanical polishing equipment as described in claim 12, characterized in that, The wafer chemical mechanical polishing (CMP) equipment may include a pre-cleaning module located downstream of the first and second polishing units after the third polishing unit is removed. The pre-cleaning module includes an adsorption stage configured to vacuum adsorb wafers and a polishing cleaning head disposed above the adsorption stage. The polishing cleaning head is configured with a polishing cleaning pad facing the adsorption stage. The adsorption stage adsorbs and fixes the wafer with the surface of the wafer polished by the first or second polishing unit facing the polishing cleaning head. The polishing cleaning pad is configured to press against the wafer and remove residual abrasive particles from the wafer surface. The polishing liquid released onto the polishing pad on the polishing stage during wafer rough polishing or fine polishing contains the abrasive particles. The pre-cleaning module forms two parallel polishing routes with the first polishing unit and the second polishing unit. In each polishing route, the wafer undergoes rough polishing, fine polishing, and polishing cleaning by passing through the two polishing tables of the first polishing unit or the second polishing unit and the pre-cleaning module, respectively.

19. A method for chemical mechanical polishing of wafers, characterized in that, It is performed using the wafer chemical mechanical polishing equipment as described in any one of claims 1-18.

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