CN118219147A

CN118219147A - Polishing bearing table and polishing method

Info

Publication number: CN118219147A
Application number: CN202410651342.3A
Authority: CN
Inventors: 朱亮; 李阳健; 郑猛; 黄金涛
Original assignee: Zhejiang Jingsheng Mechanical and Electrical Co Ltd; Zhejiang Qiushi Semiconductor Equipment Co Ltd
Current assignee: Zhejiang Jingsheng Mechanical and Electrical Co Ltd; Zhejiang Qiushi Semiconductor Equipment Co Ltd
Priority date: 2024-05-24
Filing date: 2024-05-24
Publication date: 2024-06-21
Anticipated expiration: 2044-05-24
Also published as: CN118219147B

Abstract

The application provides a polishing bearing table and a polishing method, belonging to the technical field of silicon wafer processing; comprising the following steps: the device comprises a bearing disc, a polishing pad and a detection assembly, wherein the bearing disc has a rotation degree of freedom, the polishing pad is arranged at one end of the bearing disc, which is close to a silicon wafer, and the polishing pad comprises a polishing surface for polishing the silicon wafer; the bearing disc is provided with a fluid channel, the fluid channel comprises a first section and a second section, one end of the first section extends towards the direction of the polishing pad and penetrates through the polishing pad to form a first outlet positioned on the polishing surface, the second section is communicated with the first section, and the second section is positioned on the bearing disc and connected with an external air supply piece; a detection assembly at least partially housed within the first section for detecting a fluid condition within the first section and/or the second section; the technical problems that the abnormal condition of the silicon wafer cannot be accurately identified and timely handled in the polishing process are solved, and the technical effects of accurately identifying and timely handling the abnormal condition of the silicon wafer are achieved.

Description

Polishing bearing table and polishing method

Technical Field

The application relates to the technical field of optical silicon wafer processing, in particular to a polishing bearing table and a polishing method.

Background

Silicon wafers are the main substrate material for modern very large scale integrated circuits (INTEGRATED CIRCUIT, ICs) and are typically manufactured by single crystal growth, barreling, slicing, chamfering, grinding, etching, backside processing (one or more of sand blasting, poly-or silicon dioxide), polishing, cleaning, inspection and packaging, and final polishing is the final machining process, and is also the key process for preparing high quality surface planarized silicon wafers.

The final polishing is a process of polishing the front surface of the wafer, the wafer is pressed on the polishing pad by CDA (condensed dry air, compressed dry air) pressure, and the polishing process is completed by relative rotation of the polishing pad, but in the process, the situation of flying chips, fragments and the like can occur, under the situation of flying chips, if the polishing equipment continues to operate, even larger losses can be caused, such as damage to the polishing head, the polishing pad and the like, the situation of the fragments, the flying chips and the like can be detected by the conventional polishing equipment in a general optical mode, but the optical detection generally only detects the flying chips in one direction, the situation of ignoring the flying chips in a certain direction can exist, and meanwhile, the situation of a bearing disc positioned inside the bearing disc is difficult to detect.

Thus, the prior art has problems in that: abnormal conditions of the silicon wafer cannot be accurately identified and timely dealt with in the polishing process.

Disclosure of Invention

The application provides a polishing bearing table and a polishing method, which solve the technical problem that abnormal conditions of a silicon wafer cannot be accurately identified and timely handled in the polishing process, and achieve the technical effects of accurately identifying and timely handled abnormal conditions of the silicon wafer.

The application provides a polishing bearing table, which adopts the following technical scheme that: the device comprises a bearing disc, a polishing pad and a detection assembly, wherein the bearing disc has a rotation degree of freedom, the polishing pad is arranged at one end of the bearing disc, which is close to a silicon wafer, and the polishing pad comprises a polishing surface for polishing the silicon wafer; the bearing disc is provided with a fluid channel, the fluid channel comprises a first section and a second section, one end of the first section extends towards the direction of the polishing pad and penetrates through the polishing pad to form a first outlet positioned on the polishing surface, the second section is communicated with the first section, and the second section is positioned on the bearing disc and connected with an external air supply piece; a detection assembly is at least partially housed within the first section for detecting a fluid condition within the first section and/or the second section.

Preferably, the fluid channel further comprises a third section, the third section is disposed at an end of the carrier plate away from the polishing pad, the third section is in communication with the second section, and the third section forms a second outlet on the carrier plate.

Preferably, the fluid channel comprises at least one buffer zone, the buffer zone comprises a containing cavity, and the diameter of the containing cavity is larger than the inner diameter of the fluid channel.

Preferably, the carrier platter further comprises a boss located at an end of the carrier platter remote from the polishing pad, and the third section is at least partially located within the boss.

Preferably, the bulge is sleeved with a supporting sleeve, and the inner wall of the supporting sleeve and the outer wall of the bulge are arranged at intervals; the bulge is provided with at least one air outlet channel, the air outlet channel is communicated with the third section, compressed air can flow out from the air outlet channel, and a supporting air film is formed between the outer wall of the bulge and the inner wall of the supporting sleeve.

Preferably, the fluid channel comprises more than two groups of first sections, and multiple groups of first sections are arranged on the bearing disc at intervals along the radial direction of the bearing disc; and/or, a plurality of groups of first sections are arranged on the bearing disc in a circumferential array around the axis of the bearing disc.

Preferably, an included angle between the first section central axis and the bearing disc central axis is alpha, and the included angle alpha gradually increases in a direction away from the bearing disc center.

Preferably, when the included angle α is greater than or equal to 10 °, at least one pressure relief opening is disposed at the first outlet of the first section, and the pressure relief opening is located at a side close to the center of the bearing disc.

The application also provides a polishing method for the polishing equipment, which comprises the following steps: pre-venting the first segment; placing the silicon wafer on a bearing plate; starting the bearing disc to carry out polishing operation; and keeping the air flow in the first section stable, and detecting the state of the fluid in the first section until the polishing operation is completed.

Preferably, the method further comprises: after the polishing operation is started, when the fluid is stable, the fluid state in the first section is obtained regularly, wherein the fluid state comprises flow Q and/or pressure p, and an array { Q1, Q2, Q3...Qn } and/or { p1, p2, p3...pn } is obtained according to the time arrangement; acquiring real-time parameters delta Q and/or delta p, wherein delta Q= |Qn-qk|, delta p= |pn-pk|; if Qmax is less than or equal to DeltaQ, or pmax is less than or equal to Deltap, the chip or flyer is judged.

In summary, the present application includes at least one of the following beneficial technical effects:

1. The first section is arranged in the bearing disc, the first section can penetrate through the polishing pad to form a first outlet, the first outlet can be completely closed or semi-closed under the sealing effect of the silicon wafer, and when the silicon wafer is polished, compressed gas is introduced into the polishing pad, so that a relatively stable environment can be formed in the first section under the blocking of the silicon wafer by the compressed gas; by monitoring and analyzing the state of the fluid flowing through the first section, when the first outlet cannot be continuously closed due to the broken piece or the flying piece, the situation of the flying piece is judged to occur and fed back in time, corresponding stopping measures are taken, the technical problem that the flying piece situation cannot be accurately identified and timely handled in the polishing process is solved, and the technical effects of accurately identifying and timely handling the flying piece and the broken piece situation are achieved.

2. The radial direction is provided with a plurality of groups of first sections, the processing conditions of different positions of the silicon wafer can be obtained by detecting the states of the fluids in different first sections in real time, and the processing conditions can be detected when the wafer is broken at any position, so that the technical effects of accurately identifying and timely coping with the broken wafer conditions are achieved.

3. Partial first section slope sets up, and the first section exit that the slope set up is equipped with the pressure release mouth for compressed gas can flow towards the direction that is close to the loading disc center through the pressure release mouth, can offset partial polishing liquid under the blowing of gas and because rotatory centrifugal force that receives, make the polishing liquid on the whole polishing pad divide and present even state, reduce the polishing liquid centrifugation and splash, guarantee the polishing effect.

Drawings

FIG. 1 is a schematic view of a polishing carrier of the present invention;

FIG. 2 is a schematic view of a polishing carrier according to an embodiment of the invention;

FIG. 3 is a front view of a polishing carrier of the present invention;

FIG. 4 is a cross-sectional view taken along the direction A-A in FIG. 3;

FIG. 5 is an enlarged view of portion B of FIG. 3;

FIG. 6 is a schematic view of a polishing carrier according to yet another embodiment of the invention;

FIG. 7 is a top view of a polishing platen according to the present invention;

FIG. 8 is a top view of another polishing platen of the present invention;

FIG. 9 is a top view of yet another polishing platen of the present invention;

FIG. 10 is a schematic view of an air inlet channel in a polishing carrier of the present invention;

FIG. 11 is an enlarged view of portion B of FIG. 8;

FIG. 12 is a flow chart of a polishing method of the present invention;

Fig. 13 is a flowchart for detecting abnormal processing in the polishing method of the present invention.

Reference numerals illustrate: 100. a carrying tray; 110. a boss; 111. an air outlet channel; 200. a polishing pad; 200A, polishing surface; 300. a fluid channel; 310. a first section; 311. a first outlet; 312. a pressure relief port; 320. a second section; 330. a third section; 331. a second outlet; 340. a buffer area; 341. a receiving chamber; 400. a silicon wafer; 500. an air duct; 510. a first end of the airway tube; 520. a second end of the airway tube; 521. an air outlet channel; 600. a support sleeve; 700. a detection assembly; 800. and a polishing head.

Detailed Description

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The term "coupled" as used herein includes both direct and indirect coupling (coupling), unless otherwise indicated. In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

The final polishing is a process of polishing the front surface of the wafer, the wafer is pressed on the polishing pad 200 by the pressure of CDA (condensed dry air, compressed dry air), and the polishing process is completed by the relative rotation of the polishing pad 200, but in this process, the silicon wafer 400 may itself have the conditions of flying chips, fragments, etc., and in the case of flying chips, if the polishing apparatus continues to operate, even greater loss may be caused, such as damage to the polishing head 800, the polishing pad 200, etc.; the existing polishing device generally detects the conditions of fragments, flyers and the like in an optical manner, but the optical detection generally detects the flyers only in one direction, and the condition that the flyers in a certain direction are ignored can exist, and meanwhile, the condition of the carrier tray 100 positioned inside the carrier tray 100 is difficult to detect.

Meanwhile, it should be noted that, with the development of the silicon wafer 400 manufacturing technology and the improvement of the chip yield requirement, the duty ratio of the large-sized silicon wafer 400 is higher and higher, and in the previous final polishing process, in order to improve the polishing efficiency, a plurality of silicon wafers 400 may be polished simultaneously on the same polishing pad 200; however, when polishing large-sized silicon wafer 400, as the size of silicon wafer 400 increases, the sizes of polishing pad 200 and the carrier table correspondingly increase, as the size of polishing pad 200 increases, the requirement for flatness of polishing pad 200 increases, and the requirement for smoothness of the rotating device for rotating carrier plate 100 increases, which results in a great increase in production cost, but rather, in a cost-effective manner, so that during the final polishing of large-sized silicon wafer 400, the preferred manner is as shown in fig. 1, i.e. only one silicon wafer 400 is processed on one polishing pad 200, while the number of silicon wafers 400 that can be processed on one carrier plate 100 decreases, but the processing requirement of materials decreases, and the overall manner is more cost-effective; the solution of the present application is provided on the basis of this, because only one silicon wafer 400 can be placed on one carrier table in the present application, the present application is more practical than the existing polishing apparatus in the case that the silicon wafer 400 is increased in size in the future.

Referring to fig. 1-2, the polishing carrier provided by the application adopts the following technical scheme that: the polishing device comprises a bearing disc 100, a polishing pad 200 and a detection assembly 700, wherein the bearing disc 100 has a rotation degree of freedom, the polishing pad 200 is arranged at one end of the bearing disc 100 close to a silicon wafer 400, and the polishing pad 200 comprises a polishing surface 200A for polishing the silicon wafer 400; wherein, the carrier plate 100 is provided with at least one fluid channel 300, the fluid channel 300 comprises a first section 310 and a second section 320, one end of the first section 310 extends towards the polishing pad 200 and penetrates through the polishing pad 200 to form a first outlet 311 positioned on the polishing surface 200A, and the second section 320 is positioned on the carrier plate 100 and connected with an external air supply part; the sensing assembly 700 includes a pressure sensor and/or a flow sensor housed within the first section 310 for sensing a fluid condition within the first section 310 and/or the second section 320.

In the present application, referring to fig. 1, the shape of the carrier plate 100 is the same as that of the silicon wafer 400, preferably cylindrical, and the diameter of the carrier plate 100 is larger than that of the silicon wafer 400 to be polished, the carrier plate 100 has a rotational degree of freedom, and can rotate around its axis under the drive of an external rotating member, and the rotational speed can be selected and adjusted according to actual needs. The polishing pad 200 is disposed at one end of the carrier 100 near the silicon wafer 400, and the polishing pad 200 is fixedly connected with the carrier 100, preferably in an adhesive manner; the shape of the polishing pad 200 is the same as that of the silicon wafer 400, the diameter of the polishing pad 200 is larger than or equal to that of the silicon wafer 400 and smaller than or equal to that of the bearing disc 100, the polishing pad 200 is preferably made of an abrasion-resistant material, the bearing disc 100 is preferably made of a plastic material, the thickness of the polishing pad 200 is generally smaller than that of the bearing disc 100, and the polishing pad 200 can be replaced as a consumption material; the polishing pad 200 includes at least one polishing surface 200A, the polishing surface 200A being positioned at an end of the polishing pad 200 adjacent to the silicon wafer 400, the polishing surface 200A being adapted to abut the silicon wafer 400 to complete polishing of the surface of the silicon wafer 400.

Referring to fig. 2-4, in the fluid channel 300, the fluid channel 300 is a channel through which compressed gas flows, in the present application, the fluid channel 300 is at least partially located in the carrier plate 100, the fluid channel 300 includes at least one first segment 310 and at least one second segment 320, the first segment 310 extends toward the polishing pad 200 and penetrates the polishing pad 200, and a first outlet 311 is formed on the polishing surface 200A; the second section 320 is an air inlet section, one end of the second section 320 is connected with the first section 310, the other end of the second section 320 is connected with an external air supply member, the second section 320 is preferably arranged at the center of the bottom of the carrier plate 100, and external compressed air can flow in through the second section 320, so that even if the carrier plate 100 needs to rotate at a high speed, the inflow of partial compressed air of the second section 320 is not influenced; the compressed gas provided by the external gas supply flows into the fluid channel 300 through the first section 310 and is discharged through the first outlet 311, forming a complete fluid path in the fluid channel 300, and when the first outlet 311 is closed or partially closed, a dynamic balance of the compressed gas is formed in the fluid channel 300.

A detection assembly 700, in the present application, the detection assembly 700 includes a pressure sensor or a flow sensor, or both, which may be disposed in the fluid channel 300 for detecting a fluid state in the fluid channel 300, a pressure and a flow rate; the flow rate detection device can be arranged at any position in the fluid channel 300, preferably at the inlet position of the fluid channel 300, and can detect the change condition of the flow rate in a short time; the pressure detection device is preferably arranged at the position of the first outlet 311, and the processing condition of the silicon wafer can be obtained by detecting the pressure change in the position in a short time; it is contemplated that detection assembly 700 may also be disposed within fluid channel 300 to detect a fluid condition within second section 320.

Referring to fig. 2 to 4, the arrows indicate the gas flowing direction, in the present application, when polishing is performed on a silicon wafer 400, the silicon wafer 400 will abut against a polishing pad 200 under the pressure of a polishing head 800, and the surface to be polished of the silicon wafer 400 will abut against a polishing surface 200A, so that the first outlet 311 is completely or partially closed, so that the compressed gas cannot flow out through the first outlet 311 completely, and the state of the compressed gas in the fluid channel 300 will gradually tend to be stable along with the stable rotation speed of the carrier disc 100, and the state of the compressed gas can be detected by the detecting assembly 700 under the stable state; if during this process, the silicon wafer 400 is broken or flying, the sealing condition at the first outlet 311 is changed, so that the fluid state in the first section 310 is changed. By monitoring and analyzing the fluid state flowing through the first section 310, when the first outlet 311 cannot be continuously closed due to broken or flying pieces, the flying piece condition is judged and fed back in time, corresponding stopping measures are taken, the technical problem that the flying piece condition cannot be accurately identified and timely handled in the polishing process is solved, and the technical effects of accurately identifying and timely handling the flying piece and broken piece condition are achieved.

Referring to fig. 2, the fluid channel 300 further includes a third section 330, the third section 330 is disposed at an end of the carrier plate 100 away from the polishing pad 200, the third section 330 is in communication with the second section 320, and a second outlet 331 is formed in the carrier plate 100; in one embodiment, the third section 330 is disposed at one end of the carrier plate 100 far away from the silicon wafer, the third section 330 has a second outlet 331 located outside the carrier plate 100, the second outlet 331 is preferably provided with a detachable cover to control the opening and closing of the second outlet 331, and the third section 330 and the second outlet 331 communicated with the outside are disposed, so that the third section 330 and the second section 320 can be simultaneously communicated, and the compressed gas in the fluid channel 300 can be directly detected at the second outlet 331 during testing, and meanwhile, the polishing solution may flow into the fluid channel 300, so that the fluid channel can be cleaned more conveniently by disposing the third section 330 and the second outlet 331.

Referring to fig. 4, the fluid channel 300 includes at least one buffer area 340, the buffer area 340 includes a receiving chamber 341, and the diameter of the receiving chamber 341 is larger than that of the fluid channel 300; specifically, by setting the buffer area 340, the gas in the fluid channel 300 can be buffered, that is, when the compressed gas circulates in the fluid channel 300, the gas can be buffered at the position of the buffer area 340, and the stability and accuracy of the detection assembly 700 when detecting the compressed gas are improved by setting the buffer area 340; the buffer zone 340 comprises at least one receiving chamber 341, the diameter of the receiving chamber 341 being larger than the diameter of the fluid channel 300, so that the compressed gas can be pooled at the location of the receiving chamber 341 to balance the pressure and flow rate of the compressed gas in the third section 330; the buffer zone 340 may further include a curved portion, i.e. there are a plurality of curved portions in the fluid channel 300, and the compressed gas can be buffered when flowing through the curved portion, and the receiving chamber is preferably disposed on the third section 330, so as to facilitate processing and measurement.

The carrier platter 100 further includes a boss 110, the boss 110 being located at an end of the carrier platter 100 remote from the polishing pad 200, and the third section 330 being located at least partially within the boss 110; the carrier plate 100 is generally cylindrical in shape having a bottom planar surface, and in one embodiment, the carrier plate 100 protrudes outwardly from the end of the wafer 400 to form a boss 110, the boss 110 having a fluid channel 300 disposed therein, the portion of the fluid channel 300 defining a third section 330; by providing the protruding portion 110, the third section 330 may be located outside the main body of the carrier tray 100, which facilitates the processing of the third section 330 and the detection of the gas state inside the third section, and the protruding portion 110 may be integrally manufactured with or detachably connected to the main body of the carrier tray 100.

The polishing bearing table further comprises a supporting sleeve 600, the supporting sleeve 600 is sleeved outside the protruding portion 110, the inner wall of the supporting sleeve 600 is arranged at intervals with the outer wall of the protruding portion 110, the protruding portion 110 is further provided with at least one air outlet channel 111, compressed air can flow out of the air outlet channel 111, and a supporting air film is formed between the outer wall of the protruding portion 110 and the inner wall of the supporting sleeve 600; specifically, the protruding portion 110 is disposed outside the main body portion of the carrier disc 100, a sleeve-shaped supporting sleeve 600 is sleeved outside the protruding portion 110, the supporting sleeve 600 and the protruding portion 110 are disposed at intervals, the interval is smaller, at least one air outlet channel 111 is disposed on the third section 330, the air outlet channel 111 enables air to flow out of the third section 330, the flowing compressed air keeps high flowing speed, a supporting air film is formed between the outer wall of the third section 330 and the inner wall of the supporting sleeve 600, and vibration of the carrier disc 100 can be reduced through the formed supporting air film.

Further, one or more air outlet channels 521 are provided at the bottom or on the inner wall of the accommodating cavity 341, the air outlet channels 521 may be air flow holes, etc., the compressed air may flow out from the third section 330 and then flow out through the outlet between the supporting sleeve 600 and the carrying disc 100, and a supporting air film is formed between the outer wall of the protruding portion 110 and the inner wall of the supporting sleeve 600; in the polishing process, since the carrier plate 100 needs to rotate at a high speed and pressure needs to be applied during the rotation process, it is inevitable that the carrier plate 100 itself vibrates, the existence of the vibration affects the processing effect of the silicon wafer 400, and the vibration of the carrier plate 100 itself can be reduced by the formed supporting air film.

Referring to fig. 6, in an embodiment, the polishing pad further includes an air duct 500, the air duct 500 is disposed in the fluid channel 300, an outer wall of the air duct 500 is at least partially attached to an inner wall of the fluid channel 300, a first end 510 of the air duct may extend to the polishing pad 200 and be partially located in the polishing pad 200, a second end 520 of the air duct may extend to the outside of the carrier plate 100 to form a protruding portion 110, a material of the air duct 500 is different from a material of the carrier plate 100, the polishing pad 200 in the present application is generally made of a porous material, and the compressed gas may be dispersed through the porous material, and by disposing the third section 330, a dispersing position and dispersing efficiency of the compressed gas may be controlled, and meanwhile, an inner surface of the third section 330 is smooth, which is more beneficial to a flow of the compressed gas, and meanwhile, the third section 330 is a replaceable member, and the third section 330 may be replaced in time after the polishing liquid flows into the third section 330; in one embodiment, the second end 520 of the air duct is located within the carrier tray 100, and the second end 520 of the air duct may be directly connected to an external air intake.

In one embodiment, the protruding portion 110 includes a detachable portion, the accommodating cavity 341 is located on the detachable portion, the supporting sleeve 600 may be sleeved on the outer side of the protruding portion 110 in a semi-wrapping manner, and the protruding portion 110 is communicated with the accommodating cavity 341. The accommodating cavity 341 is communicated with the protruding part 110, which is equivalent to forming an accommodating cavity 341 capable of accommodating gas in the supporting sleeve 600, and the accommodating cavity 341 is arranged to buffer the injected compressed gas, so that the pressure and the flow rate of the compressed gas can be kept stable, and meanwhile, the detection accuracy can be improved; part of the sensing device of the sensing assembly 700 may be disposed in the receiving chamber 341, and since the receiving chamber 341 is disposed in a detachable portion, the installation and replacement of the sensing assembly are facilitated.

Further, the polishing pad 200 is generally made of a porous material, and the silicon wafer 400 is a brittle material, and a large amount of tiny particles are easily generated when the silicon wafer is broken, and the tiny particles may be hidden in the gaps of the porous polishing pad 200 and cause the silicon wafer 400 to be scratched when the silicon wafer is exposed in a subsequent polishing process; in this embodiment, by providing the first segment 310, the first segment of the first segment 310 can be limited, so that the gas flows out from the inner wall of the first segment 310, and the fragments of the silicon wafer 400 and the crystallized material in the gap are pushed to move or be discharged, and the subsequent cleaning device can be matched, so that deep cleaning of the polishing pad 200 can be realized.

Referring to fig. 7-9, the polishing carrier comprises more than two sets of first segments 310, the first segments 310 being radially spaced apart on the carrier plate 100. Specifically, in one embodiment, the carrier plate 100 is provided with a plurality of first segments 310, and the plurality of first segments 310 are disposed along the radial direction of the carrier plate 100, that is, the center lines of the cross sections of the plurality of first segments 310 are located on the same straight line, preferably, the connecting line of the graphic centers of the cross sections of the plurality of first segments 310 passes through the center of the circle of the carrier plate 100; in the application, each first section 310 can be independently detected, the pressure and the flow rate of compressed gas in any first section 310 can be detected, the states of the fluid in different first sections 310 can be detected in real time through a plurality of groups of first sections 310 arranged along the radial direction, the processing conditions of different positions of the silicon wafer 400 can be obtained, and when fragments or flying fragments occur in any position, the processing conditions can be detected, so that the technical effects of accurately identifying and timely coping with the fragments are achieved; meanwhile, the pressure condition of the polishing head 800 can be correspondingly adjusted according to the change condition of the fluid state in the first section 310 at different positions, and after the silicon wafer 400 at a certain position is broken, the pressure of the polishing head 800 in a corresponding area can be correspondingly adjusted, so that the damage of the polishing head 800 caused by the fact that the polishing head 800 still maintains the same pressure is avoided; it is contemplated that in other embodiments, as shown in fig. 9, the arrangement of the first segments 310 may also be irregular.

In one embodiment, the contact surface of the polishing head 800 is elastic, when the silicon wafer 400 is broken, the broken silicon wafer 400 will be overlapped at a part of positions, and no silicon wafer 400 exists at another part, which corresponds to the thickness of the silicon wafer 400 being changed, at this time, even the elastic polishing head 800 cannot completely reproduce the situation when the silicon wafer 400 is overlapped due to the thickness of the silicon wafer 400 after being overlapped, so that the detection of the processing state of the silicon wafer 400 is feasible.

In the prior art, the silicon wafer 400 is abutted to the polishing pad 200 under the compression action of the compressed gas, and is limited by the structure of the compressed gas cushion, and the center of the polishing head 800 is more protruded relative to the edge, so that the stress of the center part of the silicon wafer 400 is larger, the stress of the edge is smaller, and the grinding degree of the center part is different from the grinding degree of the edge; in the present application, when the compressed gas flows out through the first outlet 311 of the fluid passband, a certain jacking force is provided, and because the silicon wafer 400 rotates at a high speed relative to the first section 310, the first section 310 can be approximately seen as a circular ring, which is equivalent to providing an upward pressure on a circular ring, and different forces can be provided by adjusting the air outlet states of the fluids at different positions, so as to counteract uneven stress caused by the polishing head 800; the changing method includes changing the diameter of the first segment 310, in particular, the diameter of the first segment 310 may be gradually decreased in a direction away from the center of the susceptor while the initial state of the compressed gas in each first segment 310 is the same, so that the pressure provided at the first outlet 311 of the first segment 310 is gradually increased in a direction away from the center of the susceptor 100; in one embodiment, the arrangement of the plurality of first segments 310 may be presented on the same carrier tray 100, and the specific configuration is selected according to actual needs.

Further, referring to fig. 10, an included angle α between the central axis of the first section 310 and the central axis of the carrier plate 100 is gradually increased in a direction away from the center of the carrier plate 100; specifically, in the present application, when polishing the silicon wafer 400, a polishing solution needs to be dripped on the polishing pad 200, the polishing pad 200 is preferably a porous material, and the polishing solution can be diffused on the whole polishing surface 200A after being dripped on the polishing pad 200, so that the whole polishing surface 200A is full of the polishing solution, and the polishing solution on the polishing pad 200 can diffuse towards the edge of the polishing pad 200 under the action of centrifugal force due to the rotation of the polishing pad 200, so that the polishing solution at the central part of the silicon wafer 400 has less influence on the polishing effect; in the application, by obliquely arranging the first section 310, the blown gas and the provided pressure are also oblique, and the oblique pressure enables the silicon wafer 400 to deform at a certain angle to counteract deformation caused by the compression of the polishing head 800, so that the possibility of cracking or uneven polishing of the silicon wafer 400 is reduced, and meanwhile, the silicon wafer 400 performs semi-sealing on part of the first section 310, so that the first section can blow out some gas with directions, and the part of gas can counteract the centrifugal force suffered by part of polishing liquid, so that the influence on polishing of the silicon wafer 400 caused by the centrifugal force is eliminated.

In the conventional polishing process, the polishing method is to drop the polishing liquid onto the polishing disk in advance, then abut the polishing head 800 against the polishing pad 200, spread the polishing liquid onto the entire polishing pad 200 under the dual action of pressure and porous polishing pad 200, and then start the carrier disk 100 and polishing pad 200 to finish the polishing process, and the above method is applicable to the case where a plurality of silicon wafers 400 are provided on one polishing pad 200 because a gap is left between the silicon wafers 400 and 400 in this case, but the size of the polishing pad 200 is substantially similar to the size of the silicon wafer 400 in the present application, so there is no function of continuing to supplement the polishing liquid. Referring to fig. 10-11, in one embodiment, the third section 330 further includes a third section 330, and the inlet of the third section 330 may be disposed between two adjacent first sections 310, preferably on the side with the pressure relief port, so that the polishing liquid enters the polishing pad 200 through the third section 330 and then spreads over the polishing of the entire polishing pad 200. By providing the aforementioned first segment 310, the output of the inclined gas can push the polishing liquid to flow on the polishing pad 200, increasing the flow rate of the polishing liquid, and improving the processing efficiency.

Still further, referring to FIGS. 10-11, when the included angle α is greater than or equal to 10 °, at least one pressure relief opening 312 is disposed at the first outlet 311 of the first section 310, and the pressure relief opening 312 is disposed at a side near the center of the carrier tray 100; in one embodiment, when the included angle α is greater than or equal to 10 °, the pressure relief opening 312 is disposed at a side of the first outlet 311 of the first section 310 near the central portion of the carrier plate 100, and the pressure relief opening 312 is preferably a circular arc notch, and a notch is formed between the polishing pad 200 and the surface of the silicon wafer 400, so that a part of the air flow can flow out through the pressure relief opening 312, on the basis of the inclined first section 310, the air flow and the inclination angle are further increased, and the centrifugal force applied by the polishing liquid is further counteracted, so that the outward diffusion speed of the polishing liquid is prevented, and the concentration of the polishing liquid on the whole polishing pad 200 is kept at an average level, thereby ensuring the flatness of the whole silicon wafer 400.

Referring to fig. 8, the polishing carrier comprises more than two groups of first segments 310, wherein the groups of first segments 310 are arranged on the carrier 100 in a circumferential array around the axis of the carrier 100; in one embodiment, the plurality of first segments 310 are arranged in a circumferential array on the carrier plate 100 around the axis of the carrier plate 100, and the first segments 310 are arranged circumferentially to uniformly force the polishing pad; meanwhile, in this embodiment, the detection assembly 700 is disposed in any first segment 310 and is used for detecting the state of the fluid in the first segment 310, so that the first segments 310 disposed in the circumferential array can improve the accuracy of detection, and even if occasional abnormal states occur in a certain first segment 310, the situation of erroneous judgment cannot occur on the premise that other first segments 310 keep the original state, thereby improving the accuracy of detection.

The present application also provides a polishing method for the polishing carrier, please refer to fig. 12, comprising: pre-venting the first segment 310; placing the silicon wafer on a bearing plate; starting the carrier plate 100 to perform polishing operation; detecting the fluid state in the first section 310 and monitoring the processing condition of the silicon wafer 400; if the processing conditions are consistent, the current situation is maintained until the polishing operation is completed; if an abnormal condition occurs, the processing is stopped.

Specifically, in one embodiment, the polishing process includes: the compressed gas is introduced into the first section 310 through the air inlet component, the compressed gas is preferably inert gas, the inert gas does not react with polishing solution or the surface of the silicon wafer 400, the processing process of the silicon wafer 400 is not affected, sundries possibly remained in the first section 310 can be blown out through pre-ventilation, the damage to the silicon wafer 400 is avoided, and the speed of the pre-ventilated compressed gas is higher than that in actual use; then, the polishing head 800 moves to a designated position above the first outlet 311 of the polishing pad 200, a certain distance exists between the polishing pad 200 and the surface to be polished of the silicon wafer 400, and the gas sprayed from the first section 310 can blow off impurities on the surface to be polished of the silicon wafer 400; after the blowing of the surface of the silicon wafer 400 is completed, the polishing head 800 drives the silicon wafer 400 to press down, so that the silicon wafer 400 can be abutted against the polishing surface 200A, meanwhile, the polishing head 800 applies a certain pressure to the silicon wafer 400, and the carrier plate 100 is started to enable the carrier plate 100 to rotate relative to the silicon wafer 400, so that the polishing operation of the silicon wafer 400 is completed; after the air flow is stable, detecting and monitoring the fluid state in the first section 310, and if the monitoring result is always in the result meeting the requirement, keeping the current state until the polishing operation is completed; if the abnormal condition occurs, so that the judging result does not accord with the standard in the judging unit, the judging unit judges that the abnormal condition occurs and stops processing.

Further, referring to fig. 13, detecting the processing condition of the silicon wafer 400 further includes the following steps: after the fluid stabilizes, fluid states in the first section 310, including the flow Q and/or the pressure p, are periodically acquired, and an array { Q1, Q2, Q3...qn } and/or { p1, p2, p3...pn } is obtained according to the time arrangement; acquiring real-time parameters delta Q and/or delta p, wherein delta Q= |Qn-qk|, delta p= |pn-pk|; if Qmax is less than or equal to DeltaQ, or pmax is less than or equal to Deltap, the chip or flyer is judged.

Specifically, the polishing device further comprises a judging unit, wherein the judging unit is respectively connected with the flow sensor and the pressure sensor and is used for acquiring real-time data of flow Q and/or pressure p, the flow Q is the change of air flux, the change of external input air flow or the change of air flow at any position in the fluid channel 300 can be obtained, preferably, the flow rate at the second section position is measured and combined with the pipeline cross section at the position to obtain the real-time value of the flow Q, and the value is transmitted to the judging unit; the pressure p is the pressure in the flow channel, can be measured at any position in the flow channel 300, preferably at the position of the first outlet 311, the polishing condition is monitored and controlled by the acquired data, specifically, the arrays { Q1, Q2, Q3...Qn } and { p1, p2, p3...pn } are obtained by time arrangement, and the parameters (delta Q, delta p) are obtained by calculation, wherein the calculation formula is delta Q= |Qn-qk|, delta p= |pn-pk|; if Qmax is less than or equal to DeltaQ, or pmax is less than or equal to Deltap, fragments or flying chips are judged, qmax is a flow limit value, the flow is the amount of gas passing through in a certain time, the flow limit value can be obtained through experiments, when the silicon wafer 400 is pressed on the first outlet 311, the flow is kept in a rough range, when abnormal conditions occur, abrupt change occurs, and the flow is rapidly increased; pmax is a pressure limit value, the pressure limit value can be obtained through experiments, the principle of the pressure limit value is similar to that of the flow detection, qk and pk are constants, the constants are average values which are thorough after the fluid state tends to be stable, the tendency is judged through a timing variation, and the timing variation is in a stable state within a specified range.

Principle/procedure

Firstly, cleaning the surface of the polishing pad 200 through the fluid channel 300 and other external components, dripping polishing solution, then, driving the silicon wafer 400 to move above the polishing pad 200 by the polishing head 800, cleaning the surface to be processed of the silicon wafer 400 by the fluid channel 300, then closing the air inlet part in the fluid channel 300, abutting the silicon wafer 400 on the polishing surface 200A by the polishing head 800, abutting the polishing head 800 with the polishing surface 200A, enabling the silicon wafer 400 to partially or completely seal the first outlet 311, then ventilating the first section 310, and enabling the silicon wafer 400 to rotate relative to the carrier plate 100, wherein the sealing at the outlet disappears when the silicon wafer 400 breaks and flies, the fluid state in the first section 310 can be changed greatly, and the processing condition of the silicon wafer 400 can be obtained by detecting the fluid state, so that the processing is stopped in time, and larger damage is avoided.

The technical effects are as follows:

1. The first section 310 is arranged in the bearing disc 100, the first section 310 can penetrate through the polishing pad 200 to form a first outlet 311, the first outlet 311 can be completely or semi-closed under the sealing action of the silicon wafer 400, and when the silicon wafer 400 performs polishing operation, a relatively stable environment can be formed in the first section 310 by introducing compressed gas into the polishing pad 200 under the barrier of the silicon wafer 400; by monitoring and analyzing the fluid state flowing through the first section 310, when the first outlet 311 cannot be continuously closed due to broken or flying pieces, the flying piece condition is judged and fed back in time, corresponding stopping measures are taken, the technical problem that the flying piece condition cannot be accurately identified and timely handled in the polishing process is solved, and the technical effects of accurately identifying and timely handling the flying piece and broken piece condition are achieved.

2. The plurality of groups of first sections 310 are arranged along the radial direction, and the processing conditions of different positions of the silicon wafer 400 can be obtained by detecting the states of the fluid in different first sections 310 in real time, so that the processing conditions can be detected when fragments occur at any position, and the technical effects of accurately identifying and timely coping with the fragments are achieved.

3. The first section 310 of part slope sets up, and the first section 310 exit that the slope set up is equipped with pressure release mouth 312 for compressed gas can flow towards the direction of the loading disc 100 center that is close to through pressure release mouth 312, can offset partial polishing liquid and receive centrifugal force because of the rotation under the blowing of gas, makes the polishing liquid subsection on the whole polishing pad 200 appear even state, guarantees the polishing effect.

While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A polishing carrier comprising:

-a carrier disc (100), the carrier disc (100) having a rotational degree of freedom;

A polishing pad (200), the polishing pad (200) being disposed on the carrier plate (100), the polishing pad (200) comprising a polishing surface (200A);

a fluid channel (300), the fluid channel (300) being disposed within a carrier tray (100), comprising:

a first segment (310), wherein one end of the first segment (310) extends towards the polishing pad (200) and penetrates through the polishing pad (200) to form a first outlet (311) positioned on a polishing surface (200A);

A second section (320), the second section (320) being in communication with the first section (310), the second section (320) being located on the carrier tray (100) connected to an external air supply portion; and

-A detection assembly (700), the detection assembly (700) being at least partially arranged within the fluid channel (300), the detection assembly (700) being adapted to detect a fluid state within the first section (310) and/or the second section (320).

2. The polishing platen of claim 1, wherein the fluid channel (300) further comprises a third segment (330), the third segment (330) being disposed at an end of the carrier plate (100) remote from the polishing pad (200), the third segment (330) being in communication with the second segment (320), the third segment (330) forming a second outlet (331) on the carrier plate (100).

3. The polishing platen of claim 2, wherein the fluid channel (300) includes at least one buffer zone (340), the buffer zone (340) including a receiving chamber (341), the receiving chamber (341) having a diameter greater than an inner diameter of the fluid channel (300).

4. The polishing platen of claim 2, wherein the carrier plate (100) further comprises a protrusion (110), the protrusion (110) being located at an end of the carrier plate (100) remote from the polishing pad (200), the third segment (330) being located at least partially within the protrusion (110).

5. The polishing carrier according to claim 4, characterized in that the protruding portion (110) is sleeved with a supporting sleeve (600), and the inner wall of the supporting sleeve (600) is spaced from the outer wall of the protruding portion (110); the air outlet channel (111) is arranged on the protruding portion (110), the air outlet channel (111) is communicated with the third section (330), compressed air can flow out from the air outlet channel (111), and a supporting air film is formed between the outer wall of the protruding portion (110) and the inner wall of the supporting sleeve (600).

6. The polishing platen according to claim 1, wherein the fluid channel (300) includes two or more sets of first segments (310), the sets of first segments (310) being spaced apart on the platen (100) along a radial direction of the platen (100);

and/or, a plurality of groups of the first sections (310) are arranged on the bearing disc (100) around the axis circumference array of the bearing disc (100).

7. The polishing platen according to claim 1, wherein an angle α between the central axis of the first segment (310) and the central axis of the carrier plate (100) is α, the angle α gradually increasing in a direction away from a center of the carrier plate (100).

8. The polishing carrier table according to claim 7, characterized in that when the included angle α is equal to or greater than 10 °, at least one pressure relief opening (312) is provided at the first outlet (311) of the first section (310), and the pressure relief opening (312) is located at a side near the center of the carrier plate (100).

9. A polishing method for the polishing carrier as claimed in any one of claims 1 to 8, comprising the steps of:

pre-venting the first segment (310);

placing a silicon wafer (400) on a bearing disc (100);

starting the bearing disc (100) to carry out polishing operation;

detecting the fluid state in the first section (100), and monitoring the processing condition of the silicon wafer (400) until the polishing operation is completed;

If an abnormal condition occurs, the processing is stopped.

10. The polishing method as set forth in claim 9, for detecting the presence or absence of a processing abnormality during polishing, comprising:

after the fluid stabilizes, the fluid state in the fluid channel (300) is acquired at fixed time, and the method comprises the following steps: flow Q and/or pressure p;

Obtaining an array { Q1, Q2, Q3...Qn } and/or { p1, p2, p3...pn } according to the time arrangement;

acquiring real-time parameters delta Q and/or delta p, wherein delta Q= |Qn-qk|, delta p= |pn-pk|;

If Qmax is less than or equal to DeltaQ or pmax is less than or equal to Deltap, the processing abnormality is judged.