CN221135467U - Chemical mechanical polishing system - Google Patents

Abstract

The utility model discloses a chemical mechanical polishing system, which comprises 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 part, the loading and unloading part is arranged at the side of the polishing disk, and a polishing and brushing assembly is arranged at the periphery of the loading and unloading part so as 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, and the first brush head and the second brush head are respectively arranged on the upper side and the lower side of the first swing arm so as to respectively pre-clean the front surface and the back surface of a wafer.

Description

Chemical mechanical polishing system

Technical Field

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

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 belongs to one of five main core processes in the wafer manufacturing process.

Chemical Mechanical Polishing (CMP) is a globally planarized ultra-precise surface finishing technique. After polishing the wafer, the residual liquid of the polishing liquid and the residual liquid of the grinding remain on the surface of the wafer and in the grooves of the polishing pad, even if the wafer is fully rinsed by using large-disc high-pressure water, the wafer is in frequent contact with the polishing pad, and the polishing liquid remained on the surface of the polishing pad is still unavoidable to be stained back on the surface of the wafer.

And the wafer subjected to chemical mechanical polishing is transmitted to a post-polishing cleaning module through a wafer transmission interaction system such as a mechanical arm and the like so as to carry out post-treatment such as cleaning, drying and the like on the surface of the wafer, further avoid 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 impurities stay on the surface of the wafer for a longer time, so that the particles falling to the surface of the wafer can be firmly attached to the surface of the wafer; this can result in residual impurities and residual liquids on the wafer surface being more difficult to clean and increasing the cleaning pressure, affecting the overall effectiveness of the post-polishing cleaning.

Disclosure of utility model

The embodiment of the utility model provides a chemical mechanical polishing system, which aims at solving at least one of the technical problems existing in the prior art.

A first aspect of an embodiment of the present utility model 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 part, the loading and unloading part is arranged at the side of the polishing disk, and a polishing and brushing assembly is arranged at the periphery of the loading and unloading part so as 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, and the first brush head and the second brush head are respectively arranged on the upper side and the lower side of the first swing arm so as to respectively pre-clean the front surface and the back surface of a wafer.

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

In some embodiments, the end surfaces of the first and second brush heads are configured with crisscrossed cross grooves.

In some embodiments, the first swing arm is rotatably connected to a pivot shaft, and the pivot shaft is disposed on the outer side of the loading and unloading portion and can drive the first swing arm to move along the vertical direction.

A first aspect of an embodiment of the present utility model 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 part, and the loading and unloading part is arranged at the side of the polishing disk; and a turnover mechanism is arranged between the polishing unit and the cleaning unit, and the turnover mechanism is provided with a turnover brushing assembly so as to pre-clean the surface of the wafer at a wafer turnover station.

In some embodiments, the flip brush assembly is configured with a second swing arm having a third brush head disposed at an end thereof; the third brush head can swing reciprocally around the central axis of the third brush head so as to remove particles on the surface of the wafer.

In some embodiments, the end of the third brush head is provided with a plurality of protruding structures, which are columnar structures, and the top of each 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 spray pipe located laterally of the suction plate to spray the cleaning solution toward the wafer.

The beneficial effects of the utility model 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, so that residues are prevented from being fixed on the surface of the wafer, and the difficulty of cleaning the wafer is reduced;

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 surface and the back surface 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 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.

Drawings

The advantages of the present utility model 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 utility model, wherein:

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

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

FIG. 3 is a schematic view of the positional relationship of the loading and unloading section and the polishing and brushing assembly in the present utility model;

FIG. 4 is a schematic view of a polishing and brushing assembly according to one embodiment of the present utility model;

FIG. 5 is an enlarged view of a portion of the front end of the first swing arm of FIG. 4;

FIG. 6 is a schematic end view of a second brush head according to an embodiment of the present utility model;

FIG. 7 is a schematic diagram of a chemical mechanical polishing system provided in accordance with another embodiment of the present utility model;

FIG. 8 is a schematic view of the positional relationship of the flipping mechanism and flipping brush assembly of the present utility model;

FIG. 9 is a schematic diagram of a cleaning unit according to an embodiment of the present utility model;

FIG. 10 is a schematic view of a flip brush assembly according to an embodiment of the present utility model;

fig. 11 is a partial enlarged view of the front end of the second swing arm of fig. 10.

Detailed Description

The following describes the technical scheme of the present utility model in detail with reference to specific embodiments and drawings thereof. The examples described herein are specific embodiments of the present utility model for illustrating the concept of the present utility model; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the utility model 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 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 utility model, 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 utility model, the drawings are not drawn to the same scale and like reference numerals are used to designate like parts in the drawings.

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 utility model, 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.

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 turning the polished wafer circumference 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/unloading section 25, and as shown in fig. 1, the loading/unloading section 25 is provided on a side of the polishing platen 21, and is capable of interacting with the wafer transfer device such as the carrier head 22 and the transfer robot 4.

In the embodiment shown in fig. 1, the polishing and brushing unit 6 is disposed on the outer peripheral side of the loading and unloading section 25, and the polishing and brushing unit 6 is capable of pre-cleaning the polished wafer to clean the particles remaining on the surface of the wafer.

Further, the polishing and brushing assembly 6 is disposed on the outer side of each polishing group near 225 of the turnover manipulator 4, i.e. after each polishing group finishes polishing, the polishing and brushing assembly 6 can substantially clean the surface of the wafer to control the flow of contaminants such as polishing liquid, particulate matters, etc. to the next process.

Fig. 3 is a schematic view showing a positional relationship between the polishing and brushing unit 6 and the loading and unloading portion 25 according to an embodiment of the present utility model, wherein the polishing and brushing unit 6 is disposed at a side of the loading and unloading portion 25.

Further, the polishing and brushing assembly 6 includes a first swing arm 61 and a pivot shaft 62, the pivot shaft 62 is vertically disposed at the outer side of the loading and unloading portion 25, and the first swing arm 61 is disposed 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.

Fig. 4 is a schematic view of the polishing and brushing assembly 6 of the embodiment of fig. 3, the end of the first swing arm 61 being configured 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 on the upper side and the lower side of 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. 5, 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 as to facilitate the discharge of contaminants including polishing liquid, particulate matter, and the like.

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 to the edges of the brush head to facilitate the discharge of contaminants outwardly along the helical grooves.

As an embodiment of the present utility model, at least one channel 60b is configured inside the first brush head 63 and the second brush head 64, so that the cleaning liquid is supplied to the surface of the wafer through the channel 60b, thereby obtaining a good cleaning effect.

Fig. 6 is a schematic end view of a second brush head 64 according to the present utility model, wherein a plurality of channels 60b are disposed in the second brush head 64, and the channels 60 are disposed along the length direction of the second brush head 64 to deliver cleaning liquid to the wafer surface.

In the utility model, the first brush head 63 and the second brush head 64 are made of polyurethane so as to ensure the wear resistance of the brush heads and the flexibility of the brush heads, further prevent the friction force between the brush heads and the surface of a wafer and prevent the scratch defect caused by the pre-cleaning of the brush heads. In some embodiments, first brush head 63 and second brush head 64 may be made of a Politex ^TM CMP Pad.

When the carrier head 22 loaded with the wafer moves above the loading and unloading portion 25, the first brush head 63 of the first swing arm 61 (shown in fig. 4) abuts against the front surface of the wafer and swings reciprocally, at the same time, the first brush head 63 is driven by the driving motor to rotate around its central axis, and the cleaning liquid is conveyed to the passing surface through the channel 60b, so as to pre-clean the front surface of the wafer in a contact manner.

When the wafer is unloaded from the loading and unloading portion 25, the second brush head 64 of the first swing arm 61 (shown in fig. 4) abuts against the back surface of the wafer and swings reciprocally, and at the same time, 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 through-surface via the channel 60b, so as to pre-clean the back surface of the wafer in a contact manner.

In the embodiment shown in fig. 1, the polishing brush unit 6 is configured at the position corresponding to the loading and unloading portion 25 to perform pre-cleaning of the wafer, thereby avoiding adhesion of contaminants such as particles and reducing the operation difficulty of the subsequent cleaning unit 3.

Fig. 7 is a schematic view of a chemical mechanical polishing system according to another embodiment of the present utility model, wherein the flipping mechanism 5 is configured with a flipping brush assembly 7 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.

The flipping mechanism 5 includes a chuck 51, and as shown in fig. 8, a wafer to be flipped is placed concentrically 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 section of the turnover motor 52 is connected with the suction disc 51 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 the vertical state, the liquid spray pipe 53 sprays the cleaning liquid toward the wafer while flipping the third brush head 71 (shown in fig. 7) of the brush assembly 7 to pre-clean the wafer surface.

Fig. 9 is a schematic diagram of a cleaning unit 3 according to an embodiment of the present utility model, where the cleaning unit 3 includes a frame structure formed by splicing profiles, a plurality of cleaning chambers are configured above the frame structure, a turnover mechanism 5 and a turnover brushing assembly 7 are disposed at a side of the cleaning unit 3, and the turnover mechanism 5 is disposed adjacent to the turnover robot 4, so as to pre-clean a surface of a wafer at a turnover station before the wafer is transferred to the cleaning chambers.

In the utility model, the turnover brushing assembly 7 is provided with a second swing arm 71, and as shown in fig. 10, the end part of the second swing arm 71 is provided with a third brush head 72; 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 post 73, and as shown in fig. 10, the driving post 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 post 73. The driving post 73 can move along the length direction, and the driving post 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 utility model, 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 third brush head 72 is provided at an end thereof with a plurality of projection structures 72a as shown in fig. 11; the protruding structure 71a is a columnar structure, and the top thereof is provided with an inclined surface.

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. 11, 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 the present utility model, the CMP system may also be provided with a pre-cleaning device for both the loading and unloading section 25 and the inverting mechanism 5 to pre-clean contaminants from the wafer surface before the wafer enters the cleaning unit 3, which reduces the difficulty of cleaning the wafer to some extent.

While embodiments of the present utility model 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 utility model, the scope of which is defined by the claims and their equivalents.

Claims (10)

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 part, the loading and unloading part is arranged at the side of the polishing disk, and a polishing and brushing assembly is arranged at the periphery of the loading and unloading part so as 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, and the first brush head and the second brush head are respectively arranged on the upper side and the lower side of the first swing arm so as to respectively pre-clean the front surface and the back surface of a wafer.

2. The chemical mechanical polishing system of claim 1 wherein the first and second brush heads are rotatable about their central axes, the first and second brush heads being internally configured with at least one channel for supplying cleaning fluid toward the wafer surface.

3. The chemical mechanical polishing system of claim 1, wherein the end surfaces of the first and second brush heads are configured with crisscrossed cross grooves.

4. The chemical mechanical polishing system of claim 1, wherein the first swing arm is rotatably coupled to a pivot shaft that is disposed outside the loading and unloading section and that is capable of driving the first swing arm to move in a vertical direction.

5. 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 part, and the loading and unloading part is arranged at the side of the polishing disk; and a turnover mechanism is arranged between the polishing unit and the cleaning unit, and the turnover mechanism is provided with a turnover brushing assembly so as to pre-clean the surface of the wafer at a wafer turnover station.

6. The chemical mechanical polishing system of claim 5, wherein the flip brush assembly is configured with a second swing arm having a third brush head disposed at an end thereof; the third brush head can swing reciprocally around the central axis of the third brush head so as to remove particles on the surface of the wafer.

7. The chemical mechanical polishing system of claim 6 wherein the end of the third brush head is configured with a plurality of raised structures that are columnar structures with beveled tops.

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 tube positioned laterally of the suction plate to spray cleaning liquid toward the wafer.