CN117325072A - Chemical mechanical polishing system and polishing method - Google Patents

Abstract

The invention discloses a chemical mechanical polishing system and a polishing method, wherein the chemical mechanical polishing system comprises a front unit, a polishing unit and a cleaning unit which are arranged in a modularized manner; the polishing unit comprises a polishing disk and a loading and unloading mechanism, wherein the loading and unloading mechanism is arranged at the side of the polishing disk and is used for loading and unloading wafers; a turnover mechanism is arranged between the polishing unit and the cleaning unit and is used for turnover of the wafer; the wafer pre-cleaning device is configured at the loading and unloading station and/or the overturning station to pre-clean the surface of the wafer.

Description

Chemical mechanical polishing system and polishing method

Technical Field

The invention belongs to the technical field of chemical mechanical polishing, and particularly relates to a chemical mechanical polishing system and a polishing method.

Background

The integrated circuit industry is the core of the information technology industry and plays a key role in the process of converting and upgrading the boosting manufacturing industry into digital and intelligent conversion. The chip is a carrier of an integrated circuit, and the chip manufacturing involves the process flows of integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, dicing packaging, testing, and the like. Among them, chemical mechanical polishing (Chemical Mechanical Polishing, CMP) is one of five main core processes in the wafer manufacturing process.

Chemical mechanical polishing is an ultra-precise surface machining technique for global planarization. Chemical mechanical polishing typically pulls a wafer against the bottom surface of a carrier head, the surface of the wafer having a deposited layer abutting against the upper surface of a polishing pad, the carrier head rotating in the same direction as the polishing pad under actuation of a drive assembly and imparting a downward load to the wafer; the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer is subjected to chemical mechanical polishing under the combined action of chemistry and machinery.

After the wafer is polished, polishing residual liquid and grinding residual liquid stay on the surface of the wafer and in the grooves of the polishing pad, and even if the wafer is fully rinsed by high-pressure water and is frequently contacted with the polishing pad, residual liquid remained on the surface of the polishing pad cannot be prevented from being stained back to the surface of the wafer.

And the wafer transmission interaction system such as a mechanical arm transmits the polished wafer to the post-polishing cleaning module so as to clean, dry and the like the wafer, further avoid the pollution of trace ions, metal particles and other particles to semiconductor devices, and ensure the performance and qualification rate of the semiconductor devices.

Because the transmission path from the polishing module to the cleaning module after polishing is longer, the wafer transmission consumes more time, and the residence time of the particles on the surface of the wafer is longer, so that the particles falling onto the surface of the wafer can be firmly attached to the surface of the wafer; this increases the difficulty of cleaning the wafer surface of residual contaminants, which affects the overall effectiveness of the wafer post-processing.

Disclosure of Invention

The embodiment of the invention provides a chemical mechanical polishing system and a polishing method, which aim to at least solve one of the technical problems in the prior art.

A first aspect of an embodiment of the present invention provides a chemical mechanical polishing system, including a front unit, a polishing unit, and a cleaning unit, which are arranged in a modularized manner; the polishing unit comprises a polishing disk and a loading and unloading mechanism, wherein the loading and unloading mechanism is arranged at the side of the polishing disk and is used for loading and unloading wafers; a turnover mechanism is arranged between the polishing unit and the cleaning unit and is used for turnover of the wafer; the wafer pre-cleaning device is configured at the loading and unloading station and/or the overturning station to pre-clean the surface of the wafer.

In some embodiments, the wafer pre-cleaning apparatus includes a polishing brush assembly disposed outside of the handling mechanism to clean a polished wafer; the polishing and brushing assembly comprises a first swing arm, wherein the end part of the first swing arm is provided with a first brush head and a second brush head which are respectively arranged above and below the first swing arm; when the carrying head loaded with the wafer moves to the upper side of the loading and unloading mechanism, the first brush head of the first swing arm is abutted against the front surface of the wafer and swings back and forth so as to pre-clean the front surface of the wafer; when the wafer is unloaded to the loading and unloading mechanism, the second brush head of the first swing arm is abutted against the back surface of the wafer and swings back and forth so as to pre-clean the back surface of the wafer.

In some embodiments, the first and second brush heads are rotatable about their axes, the interiors of the first and second brush heads being configured with at least one passage for supplying cleaning liquid via the passage toward the wafer surface.

In some embodiments, the end surfaces of the first brush head and the second brush head are provided with crisscrossed cross grooves, so that peeled particles can move to the outside of the brush body along the cross grooves.

In some embodiments, the first swing arm is rotatably connected to a pivot shaft, where the pivot shaft is disposed on the outer side of the loading and unloading mechanism and is capable of driving the first swing arm to move in a vertical direction so as to change the vertical positions of the first brush head and the second brush head.

In some embodiments, the wafer precleaning apparatus further includes a flip brush assembly disposed adjacent the flip mechanism to preclean the wafer surface at the wafer flip station; the overturning brushing assembly is provided with a second swing arm, and the end part of the second swing arm is provided with a third brush head; the third brush head can rotate around the central axis of the third brush head to remove particles on the surface of the wafer.

In some embodiments, the third brush head is made of polyvinyl alcohol, the ends of which are configured with a plurality of raised structures; the protruding structure is a columnar structure, and the top of the protruding structure is provided with an inclined plane.

In some embodiments, the inclined surface of the convex structure extends downwards from top to bottom, and the inclined direction of the inclined surface is deflected in the rotation direction of the third brush head in sequence.

In some embodiments, the flipping mechanism comprises a suction disc for sucking in the wafer to be flipped; the turnover mechanism is also provided with a turnover motor which is connected with the suction disc to drive the suction disc and the wafer on the suction disc to turn over.

In some embodiments, the wafer flipping station is further configured with a liquid spray pipe located laterally of the suction plate; when the suction disc and the wafer on the suction disc are turned to be in a vertical state, the liquid spraying pipe sprays cleaning liquid towards the wafer, and meanwhile, the third brush head of the turning and brushing assembly pre-cleans the surface of the wafer.

A second aspect of an embodiment of the present invention provides a chemical mechanical polishing method using the chemical mechanical polishing system described above, comprising:

s1, transmitting a wafer of the front unit to a polishing unit and performing chemical mechanical polishing;

s2, the bearing head moves the polished wafer to the upper side of the loading and unloading mechanism, the first swing arm of the polishing and brushing assembly swings to a position between the loading and unloading mechanism and the wafer, and the first brush head of the first swing arm pre-cleans the front surface of the wafer;

s3, the first swing arm of the polishing and brushing assembly swings to the outer side of the loading and unloading mechanism, and the bearing head unloads the wafer to the loading and unloading mechanism; the first swing arm of the polishing and brushing assembly swings to the upper side of the loading and unloading mechanism, and the second brush head of the first swing arm pre-cleans the back surface of the wafer;

s4, the wafer of the loading and unloading mechanism is transmitted to a wafer overturning station by the turnover manipulator, then is transferred to the cleaning unit and is subjected to wafer post-treatment, and the post-treatment is transmitted to the front unit.

A third aspect of embodiments of the present invention provides a chemical mechanical polishing method using the chemical mechanical polishing system described above, comprising:

s10, transmitting the wafer of the front unit to a polishing unit and performing chemical mechanical polishing;

s20, the bearing head moves the polished wafer to the loading and unloading mechanism;

s30, the turnover manipulator transmits the wafer of the loading and unloading mechanism to an attracting disc of a wafer overturning station, the attracting disc drives the wafer to overturn to the vertical direction, a second swing arm of the overturning and brushing assembly swings to the front side of the wafer, and a third brush head of the second swing arm abuts against the surface of the pre-cleaned wafer;

and S40, transmitting the wafer after the pre-cleaning to a cleaning unit, performing wafer post-treatment, and transmitting the wafer after the post-treatment to a front unit.

The beneficial effects of the invention include:

the CMP system is provided with a polishing brushing assembly and/or a turnover brushing assembly so as to pre-clean the surface of the wafer between the cleaning units, prevent residual pollutants from being fixed on the surface of the wafer, and be favorable for reducing the difficulty of cleaning the wafer;

b. the first swing arm of the polishing and brushing assembly is provided with a first brush head and a second brush head, so that the front and the back of the wafer are cleaned step by step in the process of loading and unloading the wafer by the bearing head, and the residual pollutants on the surface of the wafer are effectively removed;

c. the first brush head and the second brush head are made of polyurethane, the end faces of the first brush head and the second brush head are provided with cross grooves, and particles stripped from the surface of the wafer can be discharged through the cross grooves, so that the pre-cleaning effect is guaranteed;

d. the second swing arm of the turnover brushing assembly is provided with a third brush head which is made of polyvinyl alcohol, and the end face of the third brush head is provided with a protruding structure with an inclined plane, so that the contact area between the brush head and a wafer is increased, and efficient cleaning is realized.

e. The overturning and brushing assembly pre-cleans the wafer which is overturned to a vertical state, and stripped particles can be separated from the surface of the wafer under the action of gravity.

Drawings

The advantages of the present invention will become more apparent and more readily appreciated from the detailed description given in conjunction with the following drawings, which are meant to be illustrative only and not limiting of the scope of the invention, wherein:

FIG. 1 is a schematic diagram of a chemical mechanical polishing system provided in accordance with one embodiment of the present invention;

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

FIG. 3 is a schematic view of the positional relationship of the polishing brush assembly and the handling mechanism in the present invention;

FIG. 4 is an enlarged view of a portion of the front end of a first swing arm according to an embodiment of the present invention;

FIG. 5 is a schematic view of a turnover mechanism and a turnover brushing member according to an embodiment of the present invention;

FIG. 6 is an enlarged view of a portion of the front end of a second swing arm according to an embodiment of the present invention;

FIG. 7 is a flow chart of a chemical mechanical polishing method according to an embodiment of the present invention;

fig. 8 is a flow chart of a chemical mechanical polishing method according to another embodiment of the present invention.

Detailed Description

The following describes the technical scheme of the present invention in detail with reference to specific embodiments and drawings thereof. The examples described herein are specific embodiments of the present invention for illustrating the concept of the present invention; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the invention in its aspects. In addition to the embodiments described herein, those skilled in the art can adopt other obvious solutions based on the disclosure of the claims of the present application and the specification thereof, including those adopting any obvious substitutions and modifications to the embodiments described herein.

The drawings in the present specification are schematic views, which assist in explaining the concept of the present invention, and schematically show the shapes of the respective parts and their interrelationships. It should be understood that for the purpose of clearly showing the structure of various parts of embodiments of the present invention, the drawings are not drawn to the same scale and like reference numerals are used to designate like parts in the drawings.

In the present invention, "chemical mechanical polishing (Chemical Mechanical Polishing, CMP)" is also referred to as "chemical mechanical planarization (Chemical Mechanical Planarization, CMP)", and Wafer (W) is also referred to as Substrate (Substrate), the meaning and actual function are equivalent. The term "comprising" and its like are to be construed as open-ended, i.e., including, but not limited to. The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first," "second," and the like, may refer to different or the same object and are used solely to distinguish one from another without implying a particular spatial order, temporal order, order of importance, etc. of the referenced objects. In some embodiments, the values, processes, selected items, determined items, devices, means, parts, components, etc. are referred to as "best," "lowest," "highest," "smallest," "largest," etc. It should be understood that such description is intended to indicate that a selection may be made among many available options of functionality, and that such selection need not be better, lower, higher, smaller, larger, or otherwise preferred in further or all respects than other selections.

Embodiments of the present disclosure relate generally to Chemical Mechanical Polishing (CMP) units used in the semiconductor device manufacturing industry. When in chemical mechanical polishing, polishing solution composed of submicron or nanometer abrasive particles and chemical solution flows between a wafer and a polishing pad, the polishing solution is uniformly distributed under the action of transmission and rotation centrifugal force of the polishing pad to form a layer of liquid film between the wafer and the polishing pad, chemical components in the liquid react with the wafer to convert insoluble substances into soluble substances, then the chemical reactants are removed from the surface of the wafer through micro-mechanical friction of the abrasive particles and dissolved in the flowing liquid to be taken away, namely surface materials are removed in the alternating process of chemical film forming and mechanical film removing to realize surface planarization treatment, so that the aim of global planarization is achieved.

Fig. 1 is a schematic view of a chemical mechanical polishing system according to an embodiment of the present invention, wherein the chemical mechanical polishing system includes a front unit 1, a polishing unit 2, and a cleaning unit 3, which are arranged in a modularized manner.

Specifically, the head unit 1 is disposed at an end of a Chemical Mechanical Polishing (CMP) system, and includes four front opening unified pods (Front Opening Unified Pod, FOUPs) for storing wafers. One side of the front opening unified pod is provided with a front robot (not shown) for wafer transfer between the front unit 1 and other functional modules. The front-end robot is generally configured with an upper clamping jaw and a lower clamping jaw to respectively grasp the wafer after finishing processing and the wafer to be processed, so as to avoid cross contamination in the wafer clamping process.

The polishing units 2 are disposed laterally of the front unit 1 in four numbers, namely, a first polishing unit 20A, a second polishing unit 20B, a third polishing unit 20C, and a fourth polishing unit 20D. The configuration of each polishing element is the same, and the polishing elements are arranged in a line along the length direction of the CMP system; wherein, the adjacent polishing units are a group for performing chemical mechanical polishing, for example, the first polishing unit 20A and the second polishing unit 20B are a first polishing group, and the third polishing unit 20C and the fourth polishing unit 20D are a second polishing group, so as to perform chemical mechanical polishing step by step.

The cleaning unit 3 is disposed laterally of the head unit 1 and along the length direction of the CMP system. The cleaning unit 3 includes a plurality of cleaning chambers to perform megasonic cleaning, roll brush cleaning, marangoni drying, and the like.

In fig. 1, the end of the cleaning unit 3 is provided with an turnaround robot 4 capable of transferring the polished wafer to the cleaning unit 3.

Further, the chemical mechanical polishing system further includes a flipping mechanism 5 to perform a flipping operation of the wafer. Specifically, the number of the turnover mechanisms 5 is a pair, one turnover mechanism 5 is disposed between the cleaning unit 3 and the turnover manipulator 4, and the other turnover mechanism 5 is disposed between the cleaning unit 3 and the front unit 1.

Fig. 2 is a schematic view of the polishing unit 2 in the embodiment of fig. 1, the polishing unit 2 including a polishing disk 21, a polishing pad, a carrier head 22, a dressing device 23, and a liquid supply portion 24. Wherein a polishing pad is provided on the upper surface of the polishing disk 21, the polishing pad rotating together with the polishing disk 21; the bearing head 22 capable of horizontally moving is arranged above the polishing pad, and the bottom of the bearing head 22 is sucked with a wafer to be polished; the dressing device 23 swings around a fixed point, and the dressing head disposed thereon rotates itself and applies a downward load to dress the surface of the polishing pad; the liquid supply portion 24 is disposed above the polishing pad to spread the polishing liquid on the surface of the polishing pad.

During polishing operation, the carrier head 22 abuts the surface to be polished (front surface) of the wafer against the surface of the polishing pad, and the carrier head 22 makes rotary motion and reciprocates along the radial direction of the polishing disk 21 so that the surface of the wafer contacted with the polishing pad is gradually polished; while the polishing disk 21 is rotated, the liquid supply portion 24 sprays the polishing liquid to the surface of the polishing pad. The wafer is rubbed against the polishing pad by the relative motion of the carrier head 22 and the polishing platen 21 under the chemical action of the polishing liquid to perform polishing.

The dressing device 23 is used for dressing and activating the surface of the polishing pad. Impurity particles remaining on the surface of the polishing pad, such as abrasive particles in the polishing liquid, and waste material detached from the wafer surface, etc., can be removed using the dressing device 23 to dress and activate the surface of the polishing pad.

Further, the polishing unit 2 further includes a loading and unloading mechanism 25, as shown in fig. 1, the loading and unloading mechanism 25 is disposed at a side of the polishing disk 21, and can interact with the wafer transfer device such as the carrier head 22 and the transfer robot 4 to realize transfer and transfer of the wafer.

In the present invention, the cmp system further includes a pre-cleaning device configured at the loading and unloading station and/or the turning station to perform pre-cleaning of the wafer before the wafer enters the cleaning unit 3, so as to reduce the cleaning difficulty of the cleaning unit 3 to a certain extent.

The pre-cleaning device includes a polishing and brushing assembly 6 provided on the outer peripheral side of the loading and unloading mechanism 25, as shown in fig. 1; the polishing brush assembly 6 is capable of pre-cleaning the polished wafer to clean the surface of the wafer of residual particles.

Further, the polishing and brushing assembly 6 is disposed on the outer side of each polishing group near the loading and unloading mechanism 25 of the turnover manipulator 4, that is, after each polishing group finishes polishing, the polishing and brushing assembly 6 can perform pre-cleaning on the surface of the wafer, so as to control the flow of contaminants such as polishing liquid, particulate matters and the like to the next process.

Fig. 3 is a schematic view showing a positional relationship between the polishing and brushing assembly 6 and the handling mechanism 25 according to an embodiment of the present invention, wherein the polishing and brushing assembly 6 is disposed at a side of the handling mechanism 25.

Further, the polishing and brushing assembly 6 comprises a first swing arm 61 and a pivot shaft 62, the pivot shaft 62 is vertically arranged at the outer side of the loading and unloading mechanism 25, and the first swing arm 61 is arranged above the pivot shaft 62; the first swing arm 61 is capable of swinging along the central axis of the pivot shaft 62, and at the same time, the first swing arm 61 is capable of moving up and down along the length direction of the pivot shaft 62 to change the vertical position of the first swing arm 61.

The end of the first swing arm 61 is provided with a first brush head 63 and a second brush head 64; the first brush head 63 and the second brush head 64 are respectively disposed above and below the first swing arm 61 to remove the residual particles on the surface of the wafer.

Further, the first brush head 63 and the second brush head 64 are substantially identical in structure and are configured with independent driving motors, so that the first brush head 63 and the second brush head 64 can rotate around their central axes, thereby brushing out the residual contaminants on the wafer surface in a contact manner.

Further, the end surface of the first brush head 63 is provided with crisscrossed cross grooves 60a, as shown in fig. 4, so that the peeled particles can move to the outside of the brush body along the cross grooves 60 a. As one aspect of the present embodiment, the width of the cross groove 60a is 0.3-2mm, and the depth of the cross groove 60a is 1-2mm, so that contaminants including polishing liquid, particulate matter, etc. are discharged along the cross groove 60 a.

It will be appreciated that the end surfaces of the first and second brush heads 63, 64 may be other grooved structures, such as helical grooves, which extend outwardly from the center of the brush head and are formed to the edges of the brush head to facilitate the discharge of contaminants outwardly along the helical grooves.

As an embodiment of the present invention, at least one channel is configured inside the first brush head 63 and the second brush head 64, so that the cleaning liquid can flow to the surface of the wafer through the channel, and thus a good cleaning effect can be obtained.

In the present invention, the first brush head 63 and the second brush head 64 are made of polyurethane to ensure the wear resistance of the brush heads and the flexibility of the brush heads, thereby preventing the brush headsThe friction force with the surface of the wafer is overlarge, so that scratch defects caused by pre-cleaning of the brush head are avoided. In some embodiments, the first brush head 63 and the second brush head 64 may use Politex ^TM The materials from which the CMP Pad is made are formed.

When the carrier head 22 loaded with the wafer moves to the upper side of the loading and unloading mechanism 25, the first brush head 63 of the first swing arm 61 (shown in fig. 3) abuts against the front surface of the wafer and swings reciprocally, meanwhile, the first brush head 63 is driven by the driving motor to rotate around the central axis of the first brush head 63, and the cleaning liquid is conveyed to the surface of the wafer through the channel, so that the front surface of the wafer is pre-cleaned in a contact mode.

When the wafer is unloaded to the loading and unloading mechanism 25, the second brush head 64 of the first swing arm 61 (shown in fig. 3) abuts against the back of the wafer and swings reciprocally, meanwhile, the second brush head 64 is driven by the driving motor to rotate around its central axis, and the cleaning solution is conveyed to the surface of the wafer through the channel, so that the back of the wafer is pre-cleaned in a contact manner.

In the embodiment shown in fig. 1, the polishing unit 2 is configured with a polishing and brushing assembly 6 to perform pre-cleaning of the wafer at a position corresponding to the loading and unloading mechanism 25, so as to avoid adhesion of contaminants such as particulate matters and reduce the operation difficulty of the subsequent cleaning unit 3.

As one embodiment of the present invention, the flipping mechanism 5 of the cmp system is configured with a flipping brush assembly 7, as shown in fig. 5, to pre-clean the wafer surface at the wafer flipping station. It will be appreciated that the flip brush assembly 7 is configured to pre-clean the wafer surface before the wafer enters the cleaning unit 3, and therefore the flip brush assembly 7 should be disposed in the flipping mechanism 5 between the cleaning unit 3 and the transfer robot 4.

In fig. 5, the flipping mechanism 5 includes a chuck 51, and a wafer to be flipped is placed on the chuck 51. Further, the chuck plate 51 has a circular disk-like structure, and a plurality of suction holes are disposed above the chuck plate to hold the wafer to be flipped by vacuum suction.

The turnover mechanism 5 is further provided with a turnover motor 52, and an output end of the turnover motor 52 is connected with the suction disc 51 so as to drive the suction disc 51 and the wafer thereon to turn over.

Further, the wafer flipping station is further provided with a liquid spraying pipe 53, which is located at the side of the suction disc 51; when the chuck 51 and the wafer thereon are flipped to a vertical state, the liquid spray pipe 53 sprays the cleaning liquid toward the wafer surface, and simultaneously the third brush head 72 (shown in fig. 6) of the flip-brush assembly 7 moves on the wafer surface to achieve pre-cleaning of the wafer.

In some embodiments, the cleaning unit 3 comprises a frame structure formed by splicing profiles, a plurality of cleaning chambers are configured above the frame structure, the turnover mechanism 5 and the turnover brushing assembly 7 are arranged at the side of the cleaning unit 3, and the turnover mechanism 5 is arranged adjacent to the turnover manipulator 4 so as to pre-clean the surface of the wafer at the turnover station before the wafer is transferred to the cleaning chambers.

In the invention, the turnover brushing assembly 7 is provided with a second swing arm 71, and as shown in fig. 5, the end part of the second swing arm 71 is provided with a third brush head 72 (shown in fig. 6); the third brush head 72 can rotate around the central axis under the drive of the driving motor to remove particles on the surface of the wafer.

Further, the flip brush assembly 7 is further provided with a driving shaft 73, the driving shaft 73 is fixed to the frame structure, and at the same time, the second swing arm 71 is provided at an end of the driving shaft 73. The driving shaft 73 can move along the length direction, and the driving shaft 73 can drive the second swing arm 71 to swing along the central axis of the second swing arm, so that the third brush head 72 moves on the surface of the wafer.

In the present invention, the third brush head 72 is made of polyvinyl alcohol, which can absorb a certain amount of cleaning liquid, so that the third brush head 72 abutting against the surface of the wafer can remove the particles on the surface of the wafer with high efficiency.

Further, the end of the third brush head 72 is provided with a plurality of protruding structures 72a, as shown in fig. 6; the protruding structure 72a is a columnar structure, and an inclined plane is configured at the top of the protruding structure to improve the contact state between the third brush head 72 and the wafer.

Further, the inclined surface of the protrusion structure 72a extends downwards from top to bottom, and the inclined direction of the inclined surface of the protrusion structure 72a deflects along the rotation direction of the third brush head 72, so that the contact area between the protrusion structure 72a and the wafer surface becomes larger, thereby ensuring good cleaning effect.

In the embodiment shown in fig. 6, the inclined surface at the upper end of the protruding structure 72a is slightly deflected by a corresponding angle along the circumferential direction, so as to increase the contact state between the protruding structure 72a and the wafer, and improve the cleaning capability of the third brush head 72. In some embodiments, the inclined surfaces of adjacent raised structures 72a are deflected by an angle of 5-20 °.

In some embodiments, the CMP system may also configure the flip brush assembly 7 only at the wafer flip station to pre-clean the wafer surface of residual contaminants before the wafer enters the cleaning unit 3, which reduces the difficulty of cleaning the wafer to a certain extent, so as to obtain a wafer with surface cleanliness meeting the process requirements.

Meanwhile, the present invention also provides a chemical mechanical polishing method using the above-described chemical mechanical polishing system, wherein the loading and unloading mechanism 25 is provided with the polishing and brushing assembly 6. The following describes the specific steps of the chemical mechanical polishing method briefly with reference to fig. 1, a flow chart of the chemical mechanical polishing method, as shown in fig. 7, comprising:

s1, conveying a wafer of the front unit 1 to the polishing unit 2 and performing chemical mechanical polishing;

specifically, the front-end robot in the front-end unit 1 transfers the wafer to the loading and unloading mechanism 25 in the polishing unit 2, the carrier head 22 loads the wafer from the loading and unloading mechanism 25 and moves to the polishing pad on the polishing disk 21, and the liquid supply section 24 supplies the polishing liquid toward the polishing pad, and the dressing device 23 dresses the surface of the polishing pad to effect removal of the wafer surface material under the action of chemistry and machinery.

S2, the carrying head 22 moves the polished wafer to the upper side of the loading and unloading mechanism 25, the first swing arm 61 of the polishing and brushing assembly 6 swings to a position between the loading and unloading mechanism 25 and the wafer, and the first brush head 63 of the first swing arm 61 pre-cleans the front surface of the wafer;

when the first swing arm 61 swings to the loading and unloading mechanism 25, the pivot shaft 62 can move vertically, so that the first brush head 63 can be abutted against the surface of the wafer, and further the residual pollutants on the surface of the wafer can be cleaned in a contact manner. It should be noted that, when the first brush head 63 is used to brush the wafer, the carrier head 22 rotates at a certain speed, so that the first brush head 63 can cover the surface of the wafer, so as to ensure the pre-cleaning effect of the wafer.

S3, the first swing arm 61 of the polishing and brushing assembly 6 swings to the outer side of the loading and unloading mechanism 25, and the carrier head 22 unloads the wafer to the loading and unloading mechanism 25; the first swing arm 61 of the polishing and brushing assembly 6 swings to the upper side of the loading and unloading mechanism 25, and the second brush head 64 of the first swing arm 61 pre-cleans the back surface of the wafer;

step S3 is similar to step S2 in that when the first swing arm 61 is moved to the loading and unloading mechanism 25, the pivot shaft 62 can be moved vertically so that the second brush head 64 can abut against the wafer surface.

S4, the wafer of the loading and unloading mechanism 25 is transmitted to the wafer overturning station 5 by the turnover manipulator 4, then is transferred to the cleaning unit 3, is subjected to wafer post-treatment, and is transmitted to the front unit 1 after the post-treatment is completed.

Meanwhile, the invention also provides a chemical mechanical polishing method, wherein the turnover station of the chemical mechanical polishing system is provided with the turnover brushing assembly 7, and the loading and unloading mechanism 25 is provided with the polishing brushing assembly 6, and the flow chart is shown in fig. 8. The specific steps of the chemical mechanical polishing method are briefly described below:

s10, conveying the wafer of the front unit 1 to the polishing unit 2 and performing chemical mechanical polishing;

s20, the carrying head 22 moves the polished wafer to the upper side of the loading and unloading mechanism 25;

s30, the turnover manipulator 4 transmits the wafer of the loading and unloading mechanism 25 to the suction disc 51 of the wafer overturning station 5, the suction disc 51 drives the wafer to overturn to the vertical direction, the second swing arm 71 of the overturning and brushing assembly 7 swings to the front side of the wafer, and the third brush head 72 of the second swing arm 71 abuts against the surface of the pre-cleaned wafer;

the wafer to be cleaned is arranged vertically, and the pollutant peeled from the surface of the wafer can fall off from the lower edge of the wafer under the action of gravity so as to clean the surface of the wafer efficiently.

S40, the wafer after the pre-cleaning is transferred to the cleaning unit 3 and is subjected to wafer post-treatment, and the wafer after the post-treatment is transferred to the pre-unit 1.

It can be understood that the chemical mechanical polishing method provided by the invention can also be used for respectively configuring the polishing brushing assembly 6 and the overturning brushing assembly 7 at the loading and unloading station and the overturning station so as to pre-clean the wafer subjected to chemical mechanical polishing at the two stations, thereby reducing the operation difficulty of the cleaning process to a certain extent and being beneficial to guaranteeing the overall cleaning effect of the wafer.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. The chemical mechanical polishing system is characterized by comprising a front unit, a polishing unit and a cleaning unit, wherein the front unit, the polishing unit and the cleaning unit are arranged in a modularized manner; the polishing unit comprises a polishing disk and a loading and unloading mechanism, wherein the loading and unloading mechanism is arranged at the side of the polishing disk and is used for loading and unloading wafers; a turnover mechanism is arranged between the polishing unit and the cleaning unit and is used for turnover of the wafer; the wafer pre-cleaning device is configured at the loading and unloading station and/or the overturning station to pre-clean the surface of the wafer.

2. The chemical mechanical polishing system of claim 1, wherein the wafer pre-cleaning apparatus comprises a polishing brush assembly disposed outside of the handling mechanism to clean the polished wafer; the polishing and brushing assembly comprises a first swing arm, wherein the end part of the first swing arm is provided with a first brush head and a second brush head which are respectively arranged above and below the first swing arm; when the carrying head loaded with the wafer moves to the upper side of the loading and unloading mechanism, the first brush head of the first swing arm is abutted against the front surface of the wafer and swings back and forth so as to pre-clean the front surface of the wafer; when the wafer is unloaded to the loading and unloading mechanism, the second brush head of the first swing arm is abutted against the back surface of the wafer and swings back and forth so as to pre-clean the back surface of the wafer.

3. The chemical mechanical polishing system of claim 2, wherein the first and second brush heads are rotatable about their central axes, the interiors of the first and second brush heads being configured with at least one passage for supplying cleaning liquid toward the wafer surface via the passage.

4. The chemical mechanical polishing system of claim 2, wherein the end surfaces of the first and second brush heads are configured with crisscrossed cross grooves such that stripped particulate matter can move along the cross grooves to the exterior of the brush body.

5. The chemical mechanical polishing system of claim 2, wherein the first swing arm is rotatably coupled to a pivot shaft that is disposed outside the handling mechanism and that is capable of driving the first swing arm to move in a vertical direction to change the vertical position of the first brush head and the second brush head.

6. The chemical mechanical polishing system of claim 1 wherein the wafer precleaner further comprises a flip brush assembly disposed adjacent the flip mechanism to preclean the wafer surface at the wafer flip station; the overturning brushing assembly is provided with a second swing arm, and the end part of the second swing arm is provided with a third brush head; the third brush head can rotate around the central axis of the third brush head to remove particles on the surface of the wafer.

7. The chemical mechanical polishing system of claim 6 wherein the third brush head is made of polyvinyl alcohol and has an end configured with a plurality of raised structures; the protruding structure is a columnar structure, and the top of the protruding structure is provided with an inclined plane.

8. The chemical mechanical polishing system of claim 7 wherein the sloped surface of the raised structure extends from top to bottom with the sloped direction sequentially deflecting in the direction of rotation of the third brush head.

9. The chemical mechanical polishing system of claim 5, wherein the flipping mechanism comprises an engaging plate for engaging a wafer to be flipped; the turnover mechanism is also provided with a turnover motor which is connected with the suction disc to drive the suction disc and the wafer on the suction disc to turn over.

10. The chemical mechanical polishing system of claim 9 wherein the wafer flipping station is further configured with a liquid spray pipe located laterally of the suction plate; when the suction disc and the wafer on the suction disc are turned to be in a vertical state, the liquid spraying pipe sprays cleaning liquid towards the wafer, and meanwhile, the third brush head of the turning and brushing assembly pre-cleans the surface of the wafer.

11. A chemical mechanical polishing method, characterized by using the chemical mechanical polishing system according to any one of claims 1 to 5, comprising:

s1, transmitting a wafer of the front unit to a polishing unit and performing chemical mechanical polishing;

s2, the bearing head moves the polished wafer to the upper side of the loading and unloading mechanism, the first swing arm of the polishing and brushing assembly swings to a position between the loading and unloading mechanism and the wafer, and the first brush head of the first swing arm pre-cleans the front surface of the wafer;

s3, the first swing arm of the polishing and brushing assembly swings to the outer side of the loading and unloading mechanism, and the bearing head unloads the wafer to the loading and unloading mechanism; the first swing arm of the polishing and brushing assembly swings to the upper side of the loading and unloading mechanism, and the second brush head of the first swing arm pre-cleans the back surface of the wafer;

s4, the wafer of the loading and unloading mechanism is transmitted to a wafer overturning station by the turnover manipulator, then is transferred to the cleaning unit and is subjected to wafer post-treatment, and the post-treatment is transmitted to the front unit.

12. A chemical mechanical polishing method, characterized by using the chemical mechanical polishing system according to any one of claims 6 to 10, comprising:

s10, transmitting the wafer of the front unit to a polishing unit and performing chemical mechanical polishing;

s20, the bearing head moves the polished wafer to the loading and unloading mechanism;

s30, the turnover manipulator transmits the wafer of the loading and unloading mechanism to an attracting disc of a wafer overturning station, the attracting disc drives the wafer to overturn to the vertical direction, a second swing arm of the overturning and brushing assembly swings to the front side of the wafer, and a third brush head of the second swing arm abuts against the surface of the pre-cleaned wafer;

and S40, transmitting the wafer after the pre-cleaning to a cleaning unit, performing wafer post-treatment, and transmitting the wafer after the post-treatment to a front unit.