POLISHING APPARATUS AND POLISHING METHOD

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Chinese Application No. 202410341620.5, filed on Mar. 22, 2024, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to the technical field of semiconductors and, in particular, to a polishing apparatus and a polishing method.

BACKGROUND

With the rapid development of semiconductor integrated circuit manufacturing technology, chemical-mechanical polishing (CMP) technology is more and more widely used. Chemical-mechanical polishing technology can perform a planarization treatment on a surface of a wafer, avoiding fluctuation of the surface of the wafer, and providing a flat interface for the subsequent process. Thus, a polishing apparatus used in the chemical-mechanical polishing has become one of the important pieces of the apparatus in semiconductor processes.

The polishing apparatus includes a polishing table, a polishing pad disposed on the polishing table, a polishing head disposed above the polishing pad and a pad conditioner (PC). Where, the polishing head sucks and fixes the wafer, and the surface of the wafer is in contact with the polishing surface of the polishing pad and moves relative to the polishing pad at a certain pressure and rotation speed for polishing. Meanwhile, polishing liquid continuously drops on the polishing pad, and the polishing effect is achieved under the dual effects of physical mechanical and chemical actions. The pad conditioner regularly polishes and tunes the surface of the polishing pad to adjust the flatness of the polishing pad, thereby maintaining the polishing performance of the polishing pad to control the surface morphology of the wafer.

However, the existing pad conditioner has a poor tuning effect on the polishing pad, and it is easy to damage the polishing pad, for example, the polishing pad could be worn out, and the wafer is thereby scratched or damaged.

SUMMARY

In view of the above problems, embodiments of the present application provide a polishing apparatus and a polishing method to improve the tuning effect of a pad conditioner on a polishing pad.

In order to achieve the above object, a first aspect of the embodiments of the present application provides a polishing apparatus, including: a polishing pad, a movable pad conditioner, a cleaning nozzle, a pressure detecting unit provided on the cleaning nozzle, and a control unit; the pad conditioner is movable on the pressure detecting unit and in contact with the pressure detecting unit, and the pad conditioner is configured to tune the polishing pad; the pressure detecting unit is configured to measure pressure data of the pad conditioner; the cleaning nozzle is configured to clean the pad conditioner; and the control unit is electrically coupled with both the pad conditioner and the pressure detecting unit, and sets a working state of the pad conditioner according to the pressure data; where the control unit is configured to acquire the pressure data of the pad conditioner when the cleaning nozzle cleans the pad conditioner.

In some possible embodiments, the pressure detecting unit further includes: a hollow base, provided on the cleaning nozzle; and a pressure sensing element, disposed at one end of the hollow base away from the cleaning nozzle, the pressure sensing element being configured to sense the pressure data.

In some possible embodiments, the pressure sensing element further includes a pressure sensing ring, and a shape of the pressure sensing ring is the same as that of one end of the hollow base away from the cleaning nozzle.

In some possible embodiments, the pressure sensing ring further includes a conductive material layer, a spacer layer and a pressure-sensitive material layer disposed in a stacked manner, where a material of the spacer layer includes a polyester material.

In some possible embodiments, where the pressure sensing element further includes a plurality of supporting legs which are disposed at intervals and are all disposed between the pressure sensing ring and the hollow base.

In some possible embodiments, where the plurality of supporting legs and the pressure sensing ring are an integral structure, and a material of the plurality of supporting legs includes a flexible material.

In some possible embodiments, the pad conditioner further includes: a tuning base, a surface of which has a central area and an edge area surrounding the central area, a shape of the edge area corresponding to a shape of the pressure sensing ring; and tuning particles, disposed in the central area.

In some possible embodiments, where the hollow base further includes a tubular structure, a plurality of cleaning nozzles are provided, and the tubular structure is provided outside at least one cleaning nozzle.

In some possible embodiments, where the hollow base further includes an outer edge, the outer edge is disposed on a radial side wall of one end of the tubular structure facing the pad conditioner, and a surface of the outer edge facing the pad conditioner is on a same level with a surface of the tubular structure facing the pad conditioner.

In some possible embodiments, the control unit is configured to: in response to the pressure data being out of a preset pressure range, set the pad conditioner in an idle state; and in response to the pressure data being within the preset pressure range, set the pad conditioner in a polishing state; and where in response to the pad conditioner being in a polishing state, the pad conditioner performs at least one tuning on the polishing pad.

The polishing apparatus provided in the embodiments of the present application includes a polishing pad, a pad conditioner, a cleaning nozzle, a pressure detecting unit and a control unit, where the pad conditioner can be moved onto the pressure detecting unit and contact with the pressure detecting unit, the pressure detecting unit is used to measure a pressure data of the pad conditioner, the cleaning nozzle is used to clean the pad conditioner, and the control unit is electrically connected with both the pad conditioner and the pressure detecting unit, and controls a working state of the pad conditioner according to the pressure data. Use of the pressure detecting unit to monitor the pressure of the pad conditioner prevents the polishing pad from being damaged by an excessively large pressure of the pad conditioner or a by-product on the polishing pad from being difficult to be removed due to an excessively small pressure of the pad conditioner, thus ensuring the tuning effect. Compared with manual measurement and calibration, it can ensure the accuracy of measurement, reduce interference of human factors, reduce the occupation of labor hours and reduce labor costs.

A second aspect of the embodiments of the present application provides a polishing method, which is applied to the polishing apparatus as mentioned above, and the polishing method includes: step a, moving a pad conditioner of the polishing apparatus towards a pressure detecting unit and to contact with the pressure detecting unit, wherein the pressure detecting unit is provided on a cleaning nozzle of the polishing apparatus, and in response to the cleaning nozzle cleaning the pad conditioner, obtaining pressure data of the pad conditioner; step b, setting a working state of the pad conditioner according to the pressure data and a preset pressure range; and sequentially repeating the step a and step b until the pad conditioner finishes tuning for a polishing pad of the polishing apparatus or the pad conditioner is in an idle state.

In some possible embodiments, where setting the working state of the pad conditioner according to the pressure data and the preset pressure range includes: in response to the pressure data being out of the preset pressure range, setting the pad conditioner in an idle state; and in a response to the pressure data being within the preset pressure range, setting the pad conditioner in a polishing state; and in response to the pad conditioner being in a polishing state, performing, by the pad conditioner, at least one tuning on the polishing pad.

In the polishing method in the embodiments of the present application, the pressure data of the pad conditioner is obtained by controlling the pad conditioner to reach the pressure detecting unit and contact with the pressure detecting unit, and the working state of the pad conditioner is controlled according to the pressure data and the preset pressure range. The pressure data measurement of the pad conditioner and the control process of the working state of the pad conditioner are sequentially repeated until the pad conditioner finishes tuning of the polishing pads or the pad conditioner is in an idle state, so as to ensure that the pressure of the pad conditioner during tuning is within a normal range, avoiding damage to the polishing pad due to excessively large pressure of the pad conditioner or difficulty in removal of by-products on the polishing pad due to an excessively small pressure of the pad conditioner, thereby ensuring the tuning effect. In addition, by using the pressure detecting unit to obtain the pressure data of the pad conditioner, the cleaning nozzle can simultaneously clean the pad conditioner, thereby reducing the movement of the pad conditioner and reducing the complexity of the operation.

A third aspect of the embodiments of the present application provides a wafer processing system including a polishing pad, a movable pad conditioner, a cleaning nozzle, a pressure detecting unit provided on the cleaning nozzle, and a control unit; where the polishing pad is configured to polish the wafer; the pad conditioner is movable on the pressure detecting unit and in contact with the pressure detecting unit; the pressure detecting unit is configured to measure pressure data of the pad conditioner; the cleaning nozzle is configured to clean the pad conditioner; and the control unit is electrically coupled with both the pad conditioner and the pressure detecting unit, and sets a working state of the pad conditioner according to the pressure data; where the control unit is configured to acquire the pressure data of the pad conditioner when the cleaning nozzle cleans the pad conditioner.

In some possible embodiments, the pressure detecting unit further includes: a hollow base, provided on the cleaning nozzle; and a pressure sensing element, disposed at one end of the hollow base away from the cleaning nozzle, the pressure sensing element being configured to sense the pressure data.

In some possible embodiments, the pressure sensing element further includes a pressure sensing ring, and a shape of the pressure sensing ring is same as that of one end of the hollow base away from the cleaning nozzle.

In some possible embodiments, the pressure sensing ring further includes a conductive material layer, a spacer layer and a pressure-sensitive material layer disposed in a stacked manner, where a material of the spacer layer comprises a polyester material.

In some possible embodiments, the pressure sensing element further includes a plurality of supporting legs, which are disposed at intervals and are all disposed between the pressure sensing ring and the hollow base.

In some possible embodiments, the plurality of supporting legs and the pressure sensing ring are an integral structure, and a material of the plurality of supporting legs includes a flexible material.

In some possible embodiments, the pad conditioner further includes: a tuning base, a surface of which has a central area and an edge area surrounding the central area, a shape of the edge area corresponding to a shape of the pressure sensing ring; and tuning particles, disposed in the central area.

In some possible embodiments, the control unit is configured to: in response to the pressure data being out of a preset pressure range, set the pad conditioner in an idle state; and in response to the pressure data being within the preset pressure range, set the pad conditioner in a polishing state; where in response to the pad conditioner being in the polishing state, the pad conditioner performs at least one tuning on the polishing pad.

In addition to the technical problems solved by the embodiment of the present application, the technical features constituting the technical solution and the beneficial effects brought by the technical features of these technical solutions described above, other technical problems solved by the polishing apparatus and the polishing method provided in the embodiments of the present application, other technical features included in the technical solutions and the beneficial effects brought by these technical features will be further explained in detail in specific embodiments.

BRIEF DESCRIPTION OF DRAWINGS

In order to more clearly explain the technical solutions in embodiments of the present application or in the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following descriptions are some embodiments of the present application. For those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

FIG. 1 is a schematic diagram of a partial structure of a polishing apparatus in an embodiment of the present application.

FIG. 2 is a sectional view of a partial structure of the polishing apparatus in an embodiment of the present application.

FIG. 3 is a schematic diagram of a tuning base and tuning particles in an embodiment of the present application.

FIG. 4 is a sectional view of a structure of a pressure detecting unit in an embodiment of the present application.

FIG. 5 is a top view of FIG. 4.

FIG. 6 is a sectional view of another structure of the pressure detecting unit in an embodiment of the present application.

FIG. 7 is a sectional view of still another structure of the pressure detecting unit in an embodiment of the present application.

DESCRIPTION OF REFERENCE NUMERALS

• • 11—base; 12—adjusting arm;
  • 13—tuning base; 14—edge area;
  • 15—central area; 16—tuning particle;
  • 21—cleaning base; 22—pipeline;
  • 23—cleaning nozzle; 30—pressure detecting unit;
  • 31—hollow base; 32—second accommodating space;
  • 33—tubular structure; 34—outer edge;
  • 35—pressure sensing element; 36—first accommodating space;
  • 37—supporting leg; 38—pressure sensing ring.

DESCRIPTION OF EMBODIMENTS

In the related art, there exists a problem that the pad conditioner has poor tuning effect of the polishing pad. The inventor found after research that the reason is that the pad conditioner will exert a certain pressure on the polishing pad when tuning the polishing pad, and this pressure data is provided by a factory's compressor dry air (CDA). Where, the CDA is used to supply a power gas source for a pneumatic apparatus in FAB (Fabrication, FAB) and is for the purpose of purge, and the pressure data reflect the pressure of compressed air on the pad conditioner, not the real pressure of the pad conditioner, and it is difficult to monitor the pressure of the pad conditioner in real time, which makes the pad conditioner has poor tuning effect on the polishing pad. If the pressure of the pad conditioner deviates, it will cause the polishing pad to be abnormal, for example, the polishing pad will be worn out, and then the profile of the wafer will be abnormal, broken or scratched, and even the wafer will be scrapped. In addition, the pad conditioner requires manual measurement and calibration of pressure, which is labor-consuming.

Therefore, an embodiment of the present application provides a polishing apparatus, which includes a polishing pad, a pad conditioner, a cleaning nozzle, a pressure detecting unit and a control unit. The pad conditioner can be moved to the pressure detecting unit and come into contact with the pressure detecting unit. The pressure detecting unit measures the pressure data of the pad conditioner. The cleaning nozzle is used for cleaning the pad conditioner, and the control unit controls the working state of the pad conditioner according to the pressure data. Use of the pressure detecting unit to monitor the pad conditioner may prevent the polishing pad from damage due to an excessively large pressure of the pad conditioner or by-products on the polishing pad from being difficult to be removed due to an excessively small pressure of the pad conditioner, and ensure the tuning effect.

In order to make the above objectives, features and advantages of the embodiments of the present application more obvious and easy to be understood, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

Referring to FIG. 1 to FIG. 7, an embodiment of the present application provides a polishing apparatus, which includes a polishing pad, a pad conditioner, a cleaning nozzle 23, a pressure detecting unit 30 and a control unit. The polishing pad may polish, for example, a wafer, and the pad conditioner is movable, for example, the pad conditioner may be moved onto the polishing pad to polish and tune the polishing pad. The pressure detecting unit 30 is used to measure the pressure of the pad conditioner, and the cleaning nozzle 23 is used to clean the pad conditioner and clean a by-product adhered to the pad conditioner. The control unit is electrically connected with the pad conditioner and the pressure detecting unit 30, to control the working state of the pad conditioner according to the pressure data.

In some further embodiments, the polishing pad is disposed on a polishing disk, and the polishing pad is supported and fixed by the polishing disk. The polishing surface of the polishing pad is opposite to the surface of the wafer. The polishing pad can be a round pad, and the polishing surface of the polishing pad is provided with a plurality of protrusions, which are used for rubbing against the wafer when the polishing pad is rotating, and the material of the protrusions can be polyurethane fiber, and so on.

The pad conditioner polishes the polishing surface of the polishing pad and takes away by-products (such as polishing products and polishing liquid crystals) to keep the polishing surface of the polishing pad active and ensure the stability of the polishing speed rate. The pad conditioner includes a tuning base 13 and tuning particles 16 disposed on a surface of the tuning base 13, and the tuning base 13 and the tuning particles 16 form a tuning disk.

Referring to FIG. 3, the tuning particles 16 can be diamond particles, which are disposed on a surface (e.g., lower surface) of the tuning base 13 facing the polishing pad, that is, the diamond particles are disposed at one end of the tuning base 13 close to the polishing pad, and the tuning disk rubs against the polishing pad by the rotation and reciprocating motion of the pad conditioner, thus tuning the polishing surface of the polishing pad.

The surface of the tuning base 13 has a central area 15 and an edge area 14 surrounding the central area 15. The edge area 14 is the edge of the tuning base 13 as shown by the black ring in FIG. 3. The surface of the tuning base 13 refers to the surface of the tuning base 13 facing the polishing pad. The central area 15 is provided with tuning particles 16, which are shown as the black dots in FIG. 3, while the edge area 14 is not provided with the tuning particles 16. When detecting the pressure data of the pad conditioner, the edge area 14 is in contact with the pressure detecting unit 30.

In some possible embodiments, referring to FIG. 1 and FIG. 2, the pad conditioner further includes a base 11 and an adjusting arm 12, where the base 11 is disposed at a side of the polishing disk, and one end of the adjusting arm 12 is rotatably connected to the base 11, and the other end thereof is connected to the tuning base 13. The adjusting arm 12 can swing back and forth around the base 11 within a preset angle range, so as to drive the pad conditioner to swing back and forth within a preset angle range. A driving unit can be disposed in the base 11, and the driving unit is electrically connected with the adjusting arm 12 and the control unit to control the pressure of the adjusting arm 12 and the rotating speed of the tuning base 13.

The pad conditioner has a variety of working states. For example, the working states of the pad conditioner include a polishing state and an idle state. When the pad conditioner is in the polishing state, the pad conditioner performs at least one tuning on the polishing pad. When the pad conditioner is in the idle state, it is stationary to achieve shutdown, and does not tune the polishing pad. At this time, the pad conditioner may still be in contact with the polishing pad, or the pad conditioner may be away from the polishing pad for a certain distance.

The working states of the pad conditioner may also include a cleaning state. When the pad conditioner is in the cleaning state, the pad conditioner is cleaned to clean off the polishing product and polishing liquid crystal adhered to the pad conditioner.

With continued reference to FIG. 3, the pressure detecting unit 30 measures the pressure data of the pad conditioner to prevent the pressure of the pad conditioner from being too large or too small. When the pressure of the pad conditioner is too large, the pad conditioner may damage the polishing pad or even wear it out when tuning the polishing pad. When the pressure of the pad conditioner is too small, it is difficult to remove the by-products on the polishing pad when the pad conditioner polishes and tunes the polishing pad, and the tuning effect is poor.

In some possible embodiments, referring to FIG. 4 and FIG. 5, the pressure detecting unit 30 includes a hollow base 31 and a pressure sensing element 35 disposed on the hollow base 31. The hollow base 31 is provided on the cleaning nozzle 23, and the cleaning nozzle 23 can clean the pad conditioner through the hollow base 31. The pressure sensing element 35 is disposed on the hollow base 31, and the pressure sensing element 35 is used for sensing pressure data. When the pressure detecting unit 30 measures the pressure data of the pad conditioner, the pressure sensing element 35 abuts against the edge area 14 of the tuning base 13.

As shown in FIG. 4 and FIG. 5, the hollow base 31 is provided with a pressure sensing element 35 at one end away from the cleaning nozzle 23 so that the hollow base 31 supports the pressure sensing element 35, and the hollow base 31 and the pressure sensing element 35 can be detachably connected, such as clamping, bonding and the like. The pressure sensing element 35 faces the pad conditioner, and is closer to the pad conditioner, and thus is convenient to perform pressure measurement on the pad conditioner.

When the pressure detecting unit 30 measures the pressure data of the pad conditioner, the pressure sensing element 35 abuts against the edge of the tuning base 13, i.e., contacting with the edge area 14 of the tuning base 13. In this way, the pressure sensing element 35 is not in contact with the tuning particles 16, avoiding the tuning particles 16 being damaged or falling due to friction.

In some possible embodiments, the pressure sensing element 35 includes a pressure sensing ring 38, which has the same shape as an end of the hollow base 31 away from the cleaning nozzle 23. When the pressure detecting unit 30 measures the pressure data of the pad conditioner, the pressure sensing ring 38 abuts against the edge area 14 of the tuning base 13, and the tuning particles 16 are located in an area surrounded by the pressure sensing ring 38.

As shown in FIG. 4 and FIG. 5, the pressure sensing ring 38 is in a shape of ring, for example, annular or elliptical, and may be the same shape as the shape of the edge area 14 of the tuning base 13, so as to abut against the edge area 14 of the tuning base 13 to measure the pressure data of the pad conditioner. Where, the edge area 14 can be larger than the pressure sensing ring 38, so as to prevent the central area 15 from contacting with the pressure sensing ring 38 during operation, which would otherwise affect the cleaning effect.

The pressure sensing ring 38 is enclosed to form a first accommodating space 36 to accommodate the tuning particles 16 and to ensure a certain space between the tuning particles 16 and the hollow base 31. With this arrangement, the contact between the pressure sensing ring 38 and the tuning particles 16 can be avoided, and also the contact between the hollow base 31 and the tuning particles 16 can be avoided, thus reducing damage to the tuning particles 16.

The pressure sensing ring 38 converts a pressure signal into an electrical signal for transmission. In some possible embodiments, the pressure sensing ring 38 includes a conductive material layer, a spacer layer and a pressure-sensitive material layer, which are disposed in a stacked manner. A material of the spacer layer include a polyester material, so as to make the pressure sensing ring 38 flexible and avoid damage to the tuning base 13. The spacer layer has a gap. When the pressure sensing ring 38 is pressed, the conductive material layer and the pressure-sensitive material layer are bonded to establish electrical conduction, causing change in resistance of the pressure sensing ring 38. According to the change in resistance of the pressure sensing ring 38, the pressure data of the polishing pad can be obtained.

In order to further avoid the contact between the hollow base 31 and the tuning particles 16, in some possible embodiments, referring to FIG. 6, the pressure sensing element 35 further includes a plurality of supporting legs 37, which are disposed at intervals and are all disposed between the pressure sensing ring 38 and the hollow base 31. By arranging a plurality of supporting legs 37 between the pressure sensing ring 38 and the hollow base 31, the distance between the pressure sensing ring 38 and the hollow base 31 is increased, and thus the distance between the tuning particles 16 and the hollow base 31 is increased, thereby avoiding the contact between the hollow base 31 and the tuning particles 16.

Where, the plurality of supporting legs 37 can be disposed at intervals along the circumferential direction of the pressure sensing ring 38, for example, the plurality of supporting legs 37 are disposed at equal intervals along the circumferential direction of the pressure sensing ring 38, so as to improve the supporting uniformity of the plurality of supporting legs 37. In some possible embodiments, the plurality of supporting legs 37 can be screwed with the hollow base 31, and clamped and bonded with the pressure sensing ring 38. In some other possible embodiments, the plurality of supporting legs 37 and the pressure sensing ring 38 form an integral structure, and the material of the plurality of supporting legs 37 is a flexible material.

In some possible embodiments, as shown in FIG. 5 to FIG. 7, the hollow base 31 includes a tubular structure 33, and the tubular structure 33 is enclosed to form a second accommodating space 32, which can reduce the space occupied by the hollow base 31, facilitate the placement and assembly of the hollow base 31, avoid other structures, and improve the flexibility of the installation of the hollow base 31, and at the same time, the discharge of the cleaning nozzle 23 is not blocked, which ensures the cleaning ability of the cleaning nozzle 23, thereby ensuring the cleaning effect. Furthermore, the hollow base can prevent the cleaning liquid from splashing and causing pollution.

On the basis of the above embodiment, in order to facilitate the arrangement of the pressure sensing ring 38 on the hollow base 31, in some possible embodiments, referring to FIG. 7, the hollow base 31 further includes an outer edge 34, the outer edge 34 is disposed on a radial side wall of one end of the tubular structure 33 facing the pressure detecting unit 30, and a surface of the outer edge 34 facing the pad conditioner is flush with the surface of the tubular structure 33 facing the pad conditioner.

As shown in FIG. 7, the surface of the outer edge 34 facing the pad conditioner is a top surface of the outer edge 34, and the surface of the tubular structure 33 facing the pad conditioner is a top surface of the tubular structure 33. These two top surfaces are flush to form the top surface of the hollow base 31, which increases the total area of the top surface of the hollow base 31, facilitates the support of the pressure sensing element 35, and can increase the size of the pressure sensing element 35 to increase the first accommodating space 36 of the pressure sensing element 35. The thickness of the outer edge 34 is smaller than that of the tubular structure 33, and the outer edge 34 and the tubular structure 33 can be an integral structure.

Referring to FIG. 1 and FIG. 2, on the basis that the pressure detecting unit 30 includes a hollow base 31, the hollow base 31 is provided outside the cleaning nozzle 23. In this way, on one hand, the hollow base 31 is integrated outside the cleaning nozzle 23, which is convenient to realize embedded measurement, ensures the timeliness of measurement, and can track the pressure change of the pad conditioner in the long-term processes; on the other hand, the hollow base 31 is provided on the cleaning nozzle 23, which will not block the liquid discharging from the cleaning nozzle 23, thereby ensuring the cleaning ability of the cleaning nozzle 23 and thus ensuring the cleaning effect, and the hollow base can prevent the cleaning liquid from splashing and causing pollution.

In order to improve the cleaning efficiency, in some possible embodiments, there are a plurality of cleaning nozzles 23, and the tubular structure 33 is provided outside at least one cleaning nozzle 23. In this way, the tubular structure 33 can be flexibly disposed according to the number, size and spacing of the cleaning nozzles 23 and the size of the tubular structure 33, so as to avoid interference between the tubular structure 33 and the cleaning nozzles 23 and ensure that the cleaning liquid sprayed from the cleaning nozzles 23 can wash the pad conditioner.

The polishing apparatus further includes a cleaning base 21 and a pipeline 22, where the pipeline 22 is disposed in the cleaning base 21, and the cleaning nozzle 23 is disposed on the cleaning base 21 and communicates with the pipeline 22. The cleaning liquid (such as water) enters the cleaning nozzle 23 through the pipeline 22 and is sprayed on the pad conditioner through the cleaning nozzle 23 to clean the pad conditioner. Exemplarily, the cleaning liquid cleans the adjusting arm 12 and the tuning disk of the pad conditioner.

In some possible embodiments, the control unit is electrically connected with both the pad conditioner and the pressure detecting unit 30, and controls the working state of the pad conditioner according to the pressure data. When the pressure data exceeds a preset pressure range, the control unit controls the pad conditioner to be in an idle state; and when the pressure data is within the preset pressure range, the control unit controls the pad conditioner to be in a polishing state, and the pad conditioner performs at least one tuning on the polishing pad.

In some further embodiments, the preset pressure range can be standard pressure value ±0.3 pound force (lbf), and when an absolute value of the difference between the pressure data and the standard pressure value is greater than 0.3 lbf, the control unit controls the pad conditioner to be in an idle state to avoid poor tuning effect. Exemplarily, when the pressure data exceeds the preset pressure range, the control unit controls the polishing apparatus to stop and gives an alarm. Where, the preset pressure range can be set in an user event of the polishing apparatus, and the alarm can be set as P1 (2, 3, 4, . . . ) Downforce Out Of Tolerance, PLS Check Tool, and the alarm action can be set as shutdown.

When the pressure data is within a preset pressure range, for example, the absolute value of the difference between the pressure data and the standard pressure value is less than or equal to 0.3 lbf, the control unit controls the pad conditioner to be in a polishing state, and the pad conditioner performs at least one tuning on the polishing pad. In some embodiments, it may be set in the execution sequence (Sequence) of the polishing apparatus that the pad conditioner measures the pressure data once by the pressure detecting unit 30 before each time of tuning (Process).

In some possible embodiments, the control unit includes an I/O signal board, and the pressure detecting unit 30 is connected with the I/O signal board through a signal line, so that the pressure data measured by the pressure detecting unit 30 can be fed back in real time through the I/O signal board, and a real-time alarm can be issued after adding a user event. At the same time, the pressure data measured by the pressure detecting unit 30 can be added to fault detection and classification (Fault Detection & Classification, FDC) by using the I/O signal board for detection, which ensures the effectiveness of measurement and strengthens the parameter management for the polishing apparatus.

To sum up, the polishing apparatus in the embodiments of the present application includes a polishing pad, a pad conditioner, a cleaning nozzle 23, a pressure detecting unit 30 and a control unit, where the pad conditioner can be moved onto the pressure detecting unit 30 and contact with the pressure detecting unit 30, the pressure detecting unit 30 is used to measure the pressure data of the pad conditioner, the cleaning nozzle 23 is used to clean the pad conditioner, the control unit is electrically connected with both the pad conditioner and the pressure detecting unit 30, and controls the working state of the pad conditioner according to the pressure data. By monitoring the pressure data of the pad conditioner using the pressure detecting unit 30, it is possible to prevent the polishing pad from being damaged by an excessively large pressure of the pad conditioner or the by-products on the polishing pad from being difficult to be removed caused by an excessively small pressure of the pad conditioner, thereby ensuring the tuning effect. Compared with manual measurement and calibration, it can ensure the accuracy of measurement, reduce interference of human factors, reduce the occupation of labor hours and reduce labor costs.

An embodiment of the present application further provides a polishing method, applied to the above polishing apparatus. For the polishing apparatus, please refer to the above description, as well as FIG. 1 to FIG. 7, and it will not be repeated herein. The polishing method includes the following steps: step a: moving a pad conditioner of the polishing apparatus onto a pressure detecting unit and contacting with a pressure detecting unit to obtain pressure data of the pad conditioner, where the pressure detecting unit is provided on a cleaning nozzle of the polishing apparatus, and the cleaning nozzle can simultaneously clean the pad conditioner; step b: controlling a working state of the pad conditioner according to the pressure data and a preset pressure range; and sequentially repeating the step a and step b until the pad conditioner finishes tuning for a polishing pad or the pad conditioner is in an idle state.

Where, before polishing the polishing pad by the pad conditioner, the pressure data of the pad conditioner is detected by the pressure detecting unit 30 to obtain the pressure data of the pad conditioner. In some possible embodiments, the control unit controls the pad conditioner to move onto the pressure detecting unit 30 and abut against the pressure detecting unit 30 to obtain the pressure data therefrom.

The working state of the pad conditioner includes a polishing state, an idle state, and so on. When the pad conditioner is in the polishing state, the pad conditioner performs at least one time tuning on the polishing pad. When the pad conditioner is in the idle state, it is stationary to achieve shutdown and does not perform tuning on the polishing pad. At this time, the pad conditioner may still be in contact with the polishing pad, or the pad conditioner may be away from the polishing pad for a certain distance.

The working state of the pad conditioner may also include a cleaning state. When the pad conditioner is in the cleaning state, the pad conditioner is cleaned to clean the polishing products and polishing liquid crystal adhered to the pad conditioner.

The preset pressure range can be set and changed, for example, the preset pressure range is standard pressure value ±0.3 lbf. When the pressure data is within the preset pressure range, the pressure data is greater than or equal to standard pressure value −0.3 lbf and less than or equal to standard pressure value +0.3 lbf. When the pressure data is out of the preset pressure range, the pressure data is less than standard pressure value −0.3 lbf or greater than standard pressure value +0.3 lbf.

In some possible embodiments, the control unit controls the working state of the pad conditioner according to the pressure data and the preset pressure range. When the pressure data exceeds the preset pressure range, the control unit controls the pad conditioner to be in an idle state, and when the pressure data is within the preset pressure range, the control unit controls the pad conditioner to be in a polishing state. When the pad conditioner is in the polishing state, the pad conditioner performs tuning on the polishing pad for at least one time.

The measurement of the pressure data for the pad conditioner and the control process for the working state of the pad conditioner are sequentially repeated, so that the pad conditioner acquires the pressure data before the tuning at least once, making the pad conditioner maintain a good tuning effect.

The tuning of the pad conditioner can include multiple tuning. For example, the pad conditioner conducts reciprocating motions on the polishing pad, with one reciprocating motion being defined as one tuning. The pad conditioner finishing the tuning of the polishing pad means that the pad conditioner finishes all the tuning of the polishing pad, and the polished surface of the polishing pad meets a preset requirement.

When the pad conditioner finishes tuning of the polishing pad, the polishing pad does not need to be polished and tuned, and when the pad conditioner is in an idle state, the pressure of the pad conditioner needs to be calibrated. In the above two cases, the polishing method ends. After the pressure of the pad conditioner is calibrated, the polishing method can be used to continue tuning for the polishing pad.

To sum up, in the polishing method in the embodiments of the present application, the pressure data of the pad conditioner is obtained by controlling the pad conditioner onto the pressure detecting unit 30 and contacting with the pressure detecting unit 30, and the working state of the pad conditioner is controlled according to the pressure data and the preset pressure range. The pressure data measurement of the pad conditioner and the control process of the working state of the pad conditioner are sequentially repeated until the pad conditioner finishes all tunings of the polishing pads or the pad conditioner is in an idle state. In this way, it is possible to ensure that the pressure of the pad conditioner during tuning is within a normal range, which avoids damage to the polishing pad due to an excessively large pressure of the pad conditioner or avoids the by-products on the polishing pad being difficult to be removed by an excessively small pressure of the pad conditioner, and thus, the tuning effect is ensured. In addition, the pressure detecting unit 30 is used to obtain the pressure data of the pad conditioner, and the cleaning nozzle 23 can simultaneously clean the pad conditioner, thereby reducing the movement of the pad conditioner and reducing the complexity of the operation.

Embodiments of the present application further provide a wafer processing system including a polishing pad, a movable pad conditioner, a cleaning nozzle, a pressure detecting unit provided on the cleaning nozzle, and a control unit; where the polishing pad is configured to polish the wafer; the pad conditioner is movable on the pressure detecting unit and in contact with the pressure detecting unit; the pressure detecting unit is configured to measure pressure data of the pad conditioner; the cleaning nozzle is configured to clean the pad conditioner; and the control unit is electrically coupled with both the pad conditioner and the pressure detecting unit, and sets a working state of the pad conditioner according to the pressure data; where the control unit is configured to acquire the pressure data of the pad conditioner when the cleaning nozzle cleans the pad conditioner. The specific arrangement manners of the polishing pad, the pad conditioner, the cleaning nozzle, the pressure detecting device and the control unit in the wafer processing system are detailed in the aforementioned embodiments of the present application, and are not repeated here.

The embodiments or implementations in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can refer to each other.

In the description of this specification, descriptions referring to the terms “one embodiment”, “some embodiments”, “exemplary embodiments”, “examples”, “specific examples” or “some examples” mean that specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

Finally, it should be explained that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features therein can be replaced equivalently. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of various embodiments of the present application.