CN113103151A

CN113103151A - Polishing solution conveying device with polarization function and chemical mechanical polishing equipment

Info

Publication number: CN113103151A
Application number: CN202110499294.7A
Authority: CN
Inventors: 路新春; 郑鹏杰; 赵德文; 李长坤; 刘远航
Original assignee: Tsinghua University; Huahaiqingke Co Ltd
Current assignee: Tsinghua University; Huahaiqingke Co Ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2021-07-13

Abstract

The invention discloses a polishing solution conveying device with a polarization function and chemical mechanical polishing equipment, wherein the polishing solution conveying device comprises: the base is provided with a base hole; the rotating shaft is arranged in the base hole and can selectively rotate in the base hole; the cantilever is rotatably connected to the rotating shaft relative to the rotating shaft, and the interior of the cantilever is hollow; the polishing liquid pipe penetrates through the base hole and then extends into the cantilever to convey polishing liquid or gas; the nozzle assembly is communicated with the polishing liquid pipe and comprises a nozzle seat and at least one nozzle arranged below the nozzle seat; and the polarization unit is used for carrying out polarization treatment on the polishing solution.

Description

Polishing solution conveying device with polarization function and chemical mechanical polishing equipment

Technical Field

The invention relates to the technical field of chemical mechanical polishing, in particular to a polishing solution conveying device with a polarization function and chemical mechanical polishing equipment.

Background

Wafer fabrication is a critical link that restricts the development of the ultra/very large scale Integrated Circuit (i.e., chip) industry. With the continuation of moore's law, the feature size of integrated circuits continues to shrink and approach the theoretical limit, and the requirements for the surface quality of wafers are increasingly strict, so that the control of the wafer manufacturing process on the size and number of defects is increasingly strict. Chemical Mechanical Polishing (CMP) is a very important step in the wafer manufacturing process. The polishing process is to press the wafer on the surface of the polishing pad by using the bearing head, and realize the polishing of the surface of the wafer by means of the relative motion between the wafer and the polishing pad and the abrasive particles in the polishing solution.

The polishing solution contains solid polishing solution particles, which can generate particle clusters and can generate ions to deposit on the surface of the wafer in some processes to influence the polishing effect.

Disclosure of Invention

The embodiment of the invention provides a polishing solution conveying device with a polarization function and chemical mechanical polishing equipment, and aims to at least solve one of the technical problems in the prior art.

A first aspect of embodiments of the present invention provides a polishing liquid conveying apparatus having a polarization function, including:

the base is provided with a base hole;

the rotating shaft is arranged in the base hole and can selectively rotate in the base hole;

the cantilever is rotatably connected to the rotating shaft relative to the rotating shaft, and the interior of the cantilever is hollow;

the polishing liquid pipe penetrates through the base hole and then extends into the cantilever to convey polishing liquid or gas;

the nozzle assembly is communicated with the polishing liquid pipe and comprises a nozzle seat and at least one nozzle arranged below the nozzle seat;

and the polarization unit is used for carrying out polarization treatment on the polishing solution.

In one embodiment, the polarization unit is disposed upstream of the nozzle.

In one embodiment, the polarization unit is integrated inside the cantilever.

In one embodiment, the polarization unit includes a first electrode and an oppositely disposed second electrode.

In one embodiment, the polarization unit operates in a fixed voltage mode or a fixed current mode.

In one embodiment, the polishing solution comprises water, polishing solution particles, a corrosion inhibitor, an oxidizing agent, and a complexing agent.

In one embodiment, the nozzle holder is fixed to the lower surface of the cantilever.

In one embodiment, the polishing liquid delivery device further comprises a sleeve rotatably disposed outside the rotating shaft.

In one embodiment, a bearing is provided between the sleeve and the shaft.

A second aspect of an embodiment of the present invention provides a chemical mechanical polishing apparatus, including: the polishing device comprises a polishing disk, a polishing pad adhered on the polishing disk, a bearing head for adsorbing a wafer and driving the wafer to rotate, a trimmer for trimming the polishing pad, and a polishing liquid conveying device for supplying polishing liquid to the surface of the polishing pad.

The embodiment of the invention has the beneficial effects that: can prevent the cluster of the polishing solution particles, avoid the ion deposition and further improve the polishing effect.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only and do not limit the scope of protection of the invention, wherein:

FIG. 1 is a schematic structural diagram of a chemical mechanical polishing apparatus according to an embodiment of the present invention;

FIG. 2 is a perspective view of a polishing solution delivery apparatus according to an embodiment of the present invention;

FIG. 3 is a front view of a polishing solution delivery apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an internal structure of a polishing solution delivery apparatus according to an embodiment of the present invention;

fig. 5 shows the operation of the slurry delivery apparatus of fig. 4.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention for the purpose of illustrating the concepts of the invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In addition to the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious based on the disclosure of the claims and the specification thereof, and these technical solutions include technical solutions which make any obvious replacement or modification of the embodiments described herein. It should be understood that, unless otherwise specified, the following description of the embodiments of the present invention is made for the convenience of understanding, and the description is made in a natural state where relevant devices, apparatuses, components, etc. are originally at rest and no external control signals and driving forces are given.

Further, it is also noted that terms used herein such as front, back, up, down, left, right, top, bottom, front, back, horizontal, vertical, and the like, to denote orientation, are used merely for convenience of description to facilitate understanding of relative positions or orientations, and are not intended to limit the orientation of any device or structure.

In order to explain the technical solution of the present invention, the following description is made with reference to the accompanying drawings in combination with the embodiments.

In the present application, Chemical Mechanical Polishing (Chemical Mechanical Planarization) is also called Chemical Mechanical Planarization (Chemical Mechanical Planarization), and wafer (wafer) is also called substrate (substrate), which means and actually functions equally.

As shown in fig. 1, a chemical mechanical polishing apparatus 1 according to an embodiment of the present invention includes a polishing disk 10, a polishing pad 20 adhered to the polishing disk 10, a carrier head 30 for absorbing a wafer and driving the wafer to rotate, a dresser 40 for dressing the polishing pad 20, and a slurry delivery device 50 for providing a slurry to a surface of the polishing pad 20.

Before polishing starts, the robot carries the wafer to the wafer storage portion, and the carrier head 30 moves from the wafer storage portion to above the polishing disk 10 in the radial direction of the polishing disk 10 after loading the wafer. During chemical mechanical polishing, the carrier head 30 presses the wafer against the polishing pad 20 covered by the surface of the polishing disk 10, and the size of the polishing pad 20 is larger than the size of the wafer to be polished, for example, 1.2 times or more the size of the wafer, thereby ensuring that the wafer is uniformly polished. The carrier head 30 performs a rotating motion and reciprocates in a radial direction of the polishing platen 10 so that the surface of the wafer contacting the polishing pad 20 is gradually polished while the polishing platen 10 rotates, and the polishing liquid delivery device 50 sprays the polishing liquid onto the surface of the polishing pad 20. Under the chemical action of the polishing liquid, the wafer is rubbed against the polishing pad 20 by the relative movement of the carrier head 30 and the polishing platen 10 to perform polishing. Polishing liquid consisting of submicron or nanometer abrasive particles and chemical solution flows between a wafer and a polishing pad 20, the polishing liquid is uniformly distributed under the action of transmission and rotation centrifugal force of the polishing pad 20 to form a layer of liquid film between the wafer and the polishing pad 20, chemical components in the liquid and the wafer generate chemical reaction to convert insoluble substances into easily soluble substances, then the chemical reactants are removed from the surface of the wafer through micro-mechanical friction of the abrasive particles and dissolved into the flowing liquid to be taken away, namely surface materials are removed in the alternate process of chemical film forming and mechanical film removing to realize surface planarization treatment, thereby achieving the purpose of global planarization. The dresser 40 is used to dress and activate the topography of the polishing pad 20 during polishing. The dresser 40 can remove foreign particles remaining on the surface of the polishing pad 20, such as abrasive particles in the slurry and waste materials released from the surface of the wafer, and can also flatten the surface deformation of the polishing pad 20 caused by abrasion, thereby ensuring the consistency of the surface topography of the polishing pad 20 during polishing and stabilizing the removal rate of polishing. After the polishing is completed, the carrier head 30 adsorbs the wafer to place it on the wafer holding section, and the robot arm takes the wafer from the wafer holding section and transports the wafer to the post-processing unit.

An embodiment of the present invention provides a polishing liquid delivery apparatus 50 having a polarization function, which is described below with reference to fig. 2 to 5.

As shown in fig. 2 to 5, the slurry delivery apparatus 50 according to the embodiment of the present invention includes a base 51, a rotation shaft 52, a cantilever 53, a slurry tube 54, a nozzle assembly 56, and a polarization unit 85.

As shown in fig. 3, a base hole 511 is formed in the base 51, a supporting step for supporting the rotating shaft 52 is provided in the base 51, the supporting step has a supporting function, the supporting step is provided around the center of the base hole 511, when the rotating shaft 52 is supported on the supporting step, the supporting step can support the rotating shaft 52, the rotating shaft 52 can be well assembled in the base hole 511, and therefore the operational reliability of the rotating shaft 52 can be ensured. In addition, the susceptor 51 may be cylindrical having a lower end surface and an upper end surface, and the susceptor hole 511 penetrates the lower end surface and the upper end surface.

As shown in fig. 4, the rotation shaft 52 is provided in the base hole 511, and the rotation shaft 52 is provided to be selectively rotatable in the base hole 511.

As shown in fig. 1 and fig. 2, the polishing liquid delivery device 50 may further include a sleeve 57, the sleeve 57 may be rotatably disposed outside the rotating shaft 52, it should be noted that the rotating shaft 52 and the sleeve 57 may rotate relatively, the upper end of the sleeve 57 is connected to the cantilever 53, and the sleeve 57 and the cantilever 53 are relatively stationary, when the position of the cantilever 53 needs to be adjusted, the sleeve 57 may be rotated around the rotating shaft 52, thereby driving the cantilever 53 to rotate simultaneously, so as to adjust the position of the cantilever 53, and this configuration may further simplify the adjusting step, thereby making the operation simpler and more convenient.

As shown in fig. 3, a bearing 58 is disposed between the sleeve 57 and the rotating shaft 52, the bearing 58 is disposed on the upper portion and/or the lower portion of the sleeve 57, it should be explained that the bearing 58 can be disposed on the upper portion of the sleeve 57, the bearing 58 can also be disposed on the lower portion of the sleeve 57, and the bearing 58 can also be disposed on both the upper portion and the lower portion of the sleeve 57, wherein the sleeve 57 is mounted on the rotating shaft 52 via the bearing 58.

As shown in fig. 4, the rotating shaft 52 may further have a central through hole, the rotating shaft 52 may also have an upper end surface and a lower end surface, furthermore, the outer contour of the rotating shaft 52 may be cylindrical, the portion of the outer cylindrical surface of the rotating shaft 52 near the lower end surface of the rotating shaft 52 is a rotating surface, two ends of the outer cylindrical surface other than the rotating surface of the rotating shaft 52 are bearing 58 mounting positions, and the bearing 58 is mounted at the bearing 58 mounting position, so that the assembling quality of the sleeve 57 and the rotating shaft 52 can be improved, the relative rotation between the sleeve 57 and the rotating shaft 52 can be better realized, and the position of the cantilever 53 can be further conveniently adjusted.

As shown in fig. 3, the cantilever 53 is rotatably coupled to the rotating shaft 52 with respect to the rotating shaft 52, and has a hollow interior. The suspension arm 53 may include a fixed portion and a suspended portion connected to each other. The fixing portion is used for connecting with the sleeve 57, and the shape of the fixing portion is adapted to the shape of the upper end surface of the sleeve 57, so that the cantilever 53 and the sleeve 57 are well fitted together.

As shown in fig. 3, the polishing liquid pipe 54 sequentially passes through the base 51, the rotating shaft 52 and the cantilever 53 and then is connected to the nozzle holder 60, and the polishing liquid pipe 54 is communicated with the water through hole of the nozzle holder 60, so that the arrangement of the polishing liquid pipe 54 is more reasonable, the working performance of the polishing liquid pipe 54 can be improved, and the working performance of the polishing liquid delivery device 50 can be further improved.

A slurry pipe 54 extends through the base hole 511 into the cantilever 53 for delivering slurry or gas. Wherein the gas may be steam, helium, nitrogen, or the like, for supplying to the surface of the polishing pad 20 to adjust the temperature of the polishing pad 20 without affecting the polishing process. In addition, the slurry tube 54 may be made of a corrosion-resistant material, such as glass, silicon rubber, or plastic, to prevent corrosion of the slurry.

As shown in fig. 3, the nozzle assembly 56 communicates with the slurry pipe 54, and the nozzle assembly 56 includes a nozzle holder 60 and a plurality of nozzles 61 disposed below the nozzle holder 60; specifically, the nozzle 61 may be made of a material resistant to corrosion, such as glass, silicone rubber, plastic, etc., to prevent the slurry from corroding.

A nozzle assembly 56 is secured to the lower surface of the cantilever 53. The nozzle assembly 56 includes a nozzle holder 60 and a nozzle 61, the nozzle holder 60 being fixed to a lower surface of the cantilever 53, and a plurality of nozzles 61 being provided under the nozzle holder 60. The nozzle holder 60 is disposed at the bottom of the hanging part, and it should be noted that the nozzle holder 60 is fixed to the lower surface of the hanging part, the nozzle holder 60 has an upper surface and a lower surface, the upper surface of the nozzle holder 60 has a water passage hole, the lower surface of the nozzle holder 60 has a set of nozzle mounting holes, and the water passage hole is communicated with the nozzle mounting holes. The nozzle holder 60 communicates with the nozzle 61 through a nozzle mounting hole.

The polarizing unit 85 for polarizing the polishing liquid will be described with reference to fig. 4 and 5. The polishing solution mainly contains water, polishing solution particles, a corrosion inhibitor, an oxidant, a complexing agent and the like.

As shown in fig. 4 and 5, the polarization unit 85 is disposed upstream of the nozzle.

In one embodiment, the polarization unit 85 is integrated inside the cantilever with high integration without affecting other device structures. It will be appreciated that the polarization unit 85 may also be disposed outside the cantilever.

In one embodiment, the polarization unit 85 includes a first electrode 86 and an oppositely disposed second electrode 88.

The polarization unit 85 includes a first electrode 86, a first current collector 87, a second electrode 88, and a second current collector 89. The first electrode 86 and the second electrode 88 may be formed of a porous material, for example, may be formed of activated carbon, mesoporous carbon, graphene, or the like. One of the first electrode 86 and the second electrode 88 may be a positive electrode, and the other may be a negative electrode. Positive ions can be removed from the polishing solution and stored in the negative electrode, and negative ions can be removed from the polishing solution and stored in the positive electrode. A potential difference may be applied between the first current collector 87 and the second current collector 89 to charge the first electrode 86 and the second electrode 88. In particular, the electrodes of the polarization unit 85 of the polishing solution delivery apparatus according to the embodiment of the invention, including the first electrode and the second electrode, are made of non-metallic materials, so as to prevent the damage or damage of the features on the wafer surface caused by the metal ions penetrating during the delivery of the polishing solution. Further, although fig. 4 and 5 illustrate a scheme in which the polarizing unit 85 is provided at the middle portion of the polishing liquid tube 54 in the cantilever, in order to prevent a loss of polarity (loss of potential) of the polishing liquid during the delivery, it is preferable to provide the polarizing unit 85 near the end portion of the polishing liquid tube 54 closest to the nozzle 61 so that the polishing liquid is applied to the polishing pad as soon as possible after being polarized.

In one embodiment, the polarization unit 85 operates in a fixed voltage mode or a fixed current mode. In the fixed voltage mode, a fixed voltage is applied across the polarization unit 85. In the fixed current mode, a fixed current is applied across the polarization unit 85.

Fig. 5 shows the operation principle of the polarization unit 85, which changes the polarity of the polishing liquid by polarization pressurization.

In one embodiment, the polishing liquid delivery apparatus 50 further comprises an electrical signal monitoring unit connected to the polarization unit 85 for monitoring an electrical signal, such as a voltage drop or a current change, between the first electrode 86 and the second electrode 88, so as to monitor an operation state of the polarization unit 85.

The embodiment of the invention provides a polishing solution polarization scheme, which can enable the polishing solution to have a certain polarity or remove ions from the polishing solution, can avoid ion deposition, prevent the clustering of polishing solution particles, has a certain positive effect on a polishing process, and can improve the polishing effect.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of respective portions and their mutual relationships. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly show the structure of the elements of the embodiments of the invention.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

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

Claims

1. A polishing solution delivery device with a polarization function is characterized by comprising:

the base is provided with a base hole;

2. The polishing liquid feeding apparatus according to claim 1, wherein the polarization unit is disposed upstream of the nozzle.

3. The polishing solution delivery apparatus according to claim 1, wherein the polarization unit is integrated inside the cantilever.

4. The polishing solution delivery apparatus according to claim 1, wherein the polarization unit includes a first electrode and an oppositely disposed second electrode.

5. The polishing solution delivery apparatus according to claim 1, wherein the polarization unit operates in a fixed voltage mode or a fixed current mode.

6. The polishing solution delivery apparatus according to claim 1, wherein the polishing solution contains water, polishing solution particles, a corrosion inhibitor, an oxidizing agent, and a complexing agent.

7. The slurry delivery apparatus according to claim 1, wherein the nozzle holder is fixed to a lower surface of the cantilever.

8. The slurry delivery apparatus according to claim 1, further comprising a sleeve rotatably provided outside the rotary shaft.

9. The slurry delivery apparatus according to claim 8, wherein a bearing is provided between said sleeve and said shaft.

10. A chemical mechanical polishing apparatus, comprising: a polishing disk, a polishing pad adhered on the polishing disk, a carrier head for absorbing the wafer and driving the wafer to rotate, a dresser for dressing the polishing pad, and a polishing liquid delivery device according to any one of claims 1 to 9 for supplying a polishing liquid to the surface of the polishing pad.