CN111203800B

CN111203800B - Grinding pad dresser and chemical mechanical grinding equipment

Info

Publication number: CN111203800B
Application number: CN202010104099.5A
Authority: CN
Inventors: 杨俊铖
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2020-02-20
Filing date: 2020-02-20
Publication date: 2021-11-05
Anticipated expiration: 2040-02-20
Also published as: CN111203800A

Abstract

The invention relates to a grinding pad dresser, which is provided with a dressing surface, wherein the dressing surface is provided with a plurality of areas with different heights, and a plurality of dressing particles are distributed on each area, wherein the height difference of the areas ensures that when the grinding pad dresser dresses a grinding pad, the time for the dressing particles on each area to contact the grinding pad is different.

Description

Grinding pad dresser and chemical mechanical grinding equipment

Technical Field

The present invention relates to a polishing pad dresser having a longer service life and lower cost.

Background

Chemical Mechanical Polishing (CMP) is a process used in integrated circuit manufacturing to achieve global planarization, and is commonly used in processes below 0.35 um. The general method of chemical mechanical polishing is as follows: first, the surface material of the device is chemically reacted with an oxidizing agent, a catalyst, and the like in the polishing slurry to form a soft layer which is relatively easy to remove. And then, removing the soft layer under the mechanical action of the grinding material and the grinding pad in the grinding liquid, so that the surface of the device is exposed again. Then, the chemical reaction is carried out. In this way, the device surface grinding is accomplished in the alternating of the chemical action process and the mechanical action process.

Disclosure of Invention

The present invention is directed to a pad dresser having a longer service life and a lower cost.

The present invention has been made to solve the above problems, and an aspect of the present invention is to provide a polishing pad dresser having a dressing surface, wherein the dressing surface has a plurality of regions with different heights, and a plurality of dressing particles are distributed on each region, and the height difference between the plurality of regions makes the time for the dressing particles in each region to contact the polishing pad different when the polishing pad dresser dresses the polishing pad.

In an embodiment of the invention, at least one of the plurality of regions includes a plurality of unconnected sub-regions, respectively.

In an embodiment of the invention, the plurality of zones comprises concentric annular zones around the center of the dressing face.

In one embodiment of the invention, the plurality of regions includes a plurality of fan-shaped regions or arc-shaped regions that diverge outwardly from a center of the dressing face.

In one embodiment of the present invention, the grain size of the conditioning grains in the conditioning surface is uniform.

In an embodiment of the invention, the dressing particles on different dressing surfaces have different particle sizes.

In an embodiment of the invention, a ratio of a first region with the highest height among the plurality of regions to an area of the dressing surface is the largest.

In an embodiment of the invention, the plurality of regions includes a first region and a second region having successively lower heights, and when the conditioning particles in the first region are worn to make the conditioning particles in the second region contact the polishing pad, the cutting rate of the polishing pad dresser is above 70%.

In an embodiment of the invention, the plurality of regions includes a first region, a second region and a third region having sequentially decreasing heights, the cutting rate of the dresser of the polishing pad is above 70% when the dressing particles of the first region are worn to make the dressing particles of the second region contact the polishing pad, and the cutting rate of the dresser of the polishing pad is above 50% when the dressing particles of the second region are worn to make the dressing particles of the third region contact the polishing pad.

Another aspect of the present invention provides a chemical mechanical polishing apparatus comprising a polishing pad and a polishing pad dresser as described above.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following remarkable advantages:

the grinding pad dresser provided by the invention has the advantages that the dressing surface is divided into a plurality of areas with different heights, and a plurality of dressing particles are distributed on each area, so that the service life of the grinding pad dresser is prolonged, and the cost is lower.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

FIG. 1 is a schematic view of a polishing pad dresser;

FIG. 2 is a schematic illustration of conditioning particles of a polishing pad conditioner;

FIG. 3 is a schematic side view of a side view distribution of conditioning particles for a pad dresser;

FIG. 4 is a schematic side view of a distribution of conditioning particles of a pad dresser in accordance with one embodiment of the present invention;

FIG. 5 is a schematic top view of a distribution of conditioning particles of a polishing pad dresser in accordance with one embodiment of the present invention;

FIG. 6 is a schematic top view of a distribution of conditioning particles for another pad dresser in accordance with one embodiment of the present invention;

FIG. 7 is a schematic top view of a distribution of conditioning particles for another polishing pad dresser in accordance with one embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

In describing the embodiments of the present invention in detail, the cross-sectional views illustrating the structure of the device are not enlarged partially in a general scale for convenience of illustration, and the schematic drawings are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary words "below" and "beneath" can encompass both an orientation of up and down. The device may have other orientations (rotated 90 degrees or at other orientations) and the spatial relationship descriptors used herein should be interpreted accordingly. Further, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.

The chemical mechanical polishing apparatus mainly comprises a polishing pad (pad), a pad conditioner (pad conditioner) and a polishing head (head). The polishing pad is generally a soft pad made of a polymer porous material with grooves engraved thereon. The polishing pad dresser is used for dressing the polishing pad. The polishing head is used for fixing an object to be polished. For example, in chemical mechanical polishing of a silicon wafer, the back surface of the silicon wafer is pressed by a polishing head so that the front surface thereof contacts a polishing pad. At the same time, a slurry (slurry) is flowed through the conduit over the polishing pad to provide lubrication.

FIG. 1 is a schematic view of a pad dresser. Fig. 2 is a schematic illustration of conditioning particles of a polishing pad dresser. Referring to fig. 1 and 2, a polishing pad dresser embeds synthetic diamonds as dressing particles on a substrate. When a polishing pad is dressed by a polishing pad dresser, vitrification (pad glass) of the polishing pad during polishing can be prevented by cutting the polishing pad with diamond on the surface of the polishing pad dresser.

Fig. 3 is a schematic side view of a distribution of conditioning particles of a pad dresser. Referring to fig. 3, for a pad dresser 300 having only one polishing area, as it is used, the diamonds on the surface of the pad dresser 300 gradually wear, resulting in a decrease in the shearing force of the pad dresser 300, requiring frequent replacement, and being costly.

In view of the above, the following embodiments of the present invention provide a pad dresser having a longer service life and a lower cost.

It is to be understood that the following description is merely exemplary, and that variations may be made by those skilled in the art without departing from the spirit of the invention.

The grinding pad dresser is provided with a dressing surface, the dressing surface is provided with a plurality of areas with different heights, and a plurality of dressing particles are distributed on each area, wherein the height difference of the areas ensures that when the grinding pad dresser dresses the grinding pad, the time for the dressing particles on each area to contact the grinding pad is different. In an embodiment of the present invention, the number of the plurality of regions is at least 3.

FIG. 4 is a schematic side view of a distribution of conditioning particles of a pad dresser in accordance with one embodiment of the present invention. Referring to fig. 4, a polishing pad dresser 400 has a dressing surface having a plurality of zones, such as zone 410, zone 420, and zone 430, of different heights. A plurality of conditioning particles are distributed on each area. Illustratively, a plurality of conditioning particles 411 may be distributed over area 410, a plurality of conditioning particles 421 may be distributed over area 420, and a plurality of conditioning particles 431 may be distributed over area 430. The shape of the conditioning particles 431 may be any shape such as a cone, a cylinder, a sphere, and the like.

Wherein the height difference of the plurality of zones (e.g., zone 410, zone 420, and zone 430) is such that when the polishing pad dresser 400 dresses the polishing pad (not shown), the time at which the dressing particles (e.g., dressing particles 411, dressing particles 421, or dressing particles 431) on each zone (e.g., zone 410, zone 420, or zone 430) contact the polishing pad is different.

In some examples, the dressing surface of the pad dresser may also have more than 3 regions of different heights. For example, the polishing pad dresser 400 shown in fig. 4 may have more than 3 regions with different heights, but the embodiment is not limited thereto.

It is understood that the conditioning particles in the conditioning face may be the same or different in size. The grain diameters of the dressing particles in the same dressing surface may be the same or different, and the grain diameters of the dressing particles in different dressing surfaces may be the same or different from each other. Preferably, in the following examples of the present invention, the particle diameters of the conditioning particles in the conditioning face are uniform. For example, the dressing particles 411, the dressing particles 421 and the dressing particles 431 in the polishing pad dresser 400 shown in fig. 4 may be diamonds having the same size, but the present application is not limited thereto.

In an embodiment of the invention, at least one of the plurality of regions includes a plurality of unconnected sub-regions, respectively. For example, for the pad conditioner 400 shown in fig. 4, at least one of the

regions

410, 420, and 430 may each include two or more unconnected sub-regions (not shown).

In one embodiment of the present invention, the plurality of regions of the polishing pad dresser having different heights of the dressing surface include concentric annular regions around a center of the dressing surface.

FIG. 5 is a schematic top view of a distribution of conditioning particles of a polishing pad dresser, in accordance with one embodiment of the present invention. Referring to fig. 5, the dressing surface of the pad dresser 500 has a plurality of regions with different heights, namely, a region 510, a region 520, a region 530, a region 540, and a region 550. Wherein

regions

510, 520, 530, 540, and 550 are each concentric annular regions around the center of the conditioning face.

In one example shown in fig. 5, region 510 includes 2 unconnected sub-regions, sub-region 510a and sub-region 510b, respectively. The region 520 includes 3 unconnected sub-regions, sub-region 520a, sub-region 520b, and sub-region 520 c. Region 530 includes 2 unconnected sub-regions, sub-region 530a and sub-region 530b, respectively. Region 540 includes 2 unconnected sub-regions, sub-region 540a and sub-region 540b, respectively.

The trim surfaces of the sub-areas of the same area have the same height. For example, region 510, region 520, region 530, region 540, and region 550 each have a different height. For region 510, sub-region 510a and sub-region 510b have the same height. For region 520, sub-region 520a, sub-region 520b, and sub-region 520c have the same height, and so on.

In one embodiment of the invention, the plurality of regions comprises a plurality of fan-shaped regions that diverge outwardly from the center of the conditioning face.

FIG. 6 is a schematic top view of a distribution of conditioning particles for another polishing pad dresser in accordance with one embodiment of the present invention. Referring to fig. 6, the dressing surface of the pad dresser 600 has a plurality of regions,

regions

610, 620, and 630, having different heights. Wherein

regions

610, 620, and 630 are a plurality of fan-shaped regions that diverge outwardly from the center of the conditioning face.

In one example shown in fig. 6, region 610 includes 8 unconnected sub-regions, sub-region 610a, sub-region 610b, sub-region …, sub-region 610 h. Region 620 includes 12 unconnected sub-regions,

sub-regions

620a, 620b, …, sub-region 620l, respectively. The region 630 includes 12 unconnected sub-regions,

sub-regions

630a, 630b, …, sub-region 630l, respectively.

Similarly, the trim surfaces of multiple sub-regions of the same region have the same height. For example, the area 610, the area 620, and the area 630 have different heights, respectively. For the region 610, its

sub-regions

610a, 610b, …, sub-region 610h have the same height. For region 620,

sub-regions

620a, 620b, … sub-region 620l have the same height. For region 630,

sub-regions

630a, 630b, …, sub-region 630l have the same height.

FIG. 7 is a schematic top view of a distribution of conditioning particles for another polishing pad dresser in accordance with one embodiment of the present invention. Referring to fig. 7, the dressing surface of the pad dresser 700 has a plurality of regions, i.e., a region 710, a region 720, and a region 730, having different heights. Wherein

regions

710, 720, and 730 are a plurality of arcuate regions that diverge outwardly from the center of the conditioning face.

In one example shown in fig. 7, region 710 includes 2 unconnected sub-regions, sub-region 710a and sub-region 710b, respectively. Region 720 includes 2 unconnected sub-regions, sub-region 720a and sub-region 720b, respectively. Region 730 includes 2 unconnected sub-regions, sub-region 730a and sub-region 730b, respectively.

Similarly, the trim surfaces of multiple sub-regions of the same region have the same height. For example, the

regions

710, 720, and 730 have different heights, respectively. For region 710, sub-region 710a and sub-region 710b have the same height. For the region 720, the sub-region 720a and the sub-region 720b have the same height. For region 730, sub-region 730a and sub-region 730b have the same height.

It should be appreciated that when a polishing pad dresser having a plurality of arc-shaped regions as shown in fig. 7 is used to dress a polishing pad, the rotation direction of the polishing pad dresser can be made to coincide with the bending direction of the plurality of arc-shaped regions (e.g., in fig. 7, the polishing pad dresser is rotated in a counterclockwise direction). Thus, the rotation of the pad dresser can be smoother, and particles and liquid generated during the polishing process can be more smoothly thrown out along the rotation direction of the pad dresser.

In an embodiment of the invention, a ratio of an area of a first region with a highest height among the plurality of regions to the dressing surface is largest.

Illustratively, referring to fig. 4, among the plurality of regions of the pad dresser 400, the area ratio of the region 410 (first region) having the highest height to the dressing surface may be the largest.

With continued reference to fig. 4, the plurality of zones of the pad dresser 400 include a zone 410 (first zone) and a zone 420 (second zone) of successively decreasing height. The cutting rate of the polishing pad dresser 400 is above 70% when the conditioning particles 411 in the region 410 wear down such that the conditioning particles 421 in the region 420 contact the polishing pad.

In other examples, the plurality of zones includes a first zone, a second zone, and a third zone having successively decreasing heights, the cutting rate of the polishing pad dresser being greater than 70% when the conditioning particles in the first zone are worn to cause the conditioning particles in the second zone to contact the polishing pad, and the cutting rate of the polishing pad dresser being greater than 50% when the conditioning particles in the second zone are worn to cause the conditioning particles in the third zone to contact the polishing pad.

For example, the polishing pad dresser 400 shown in fig. 4 has a region 410 (first region), a region 420 (second region), and a region 430 (third region) that are successively lower in height. The cutting rate of the polishing pad dresser 400 is above 70% when the conditioning particles 411 in the region 410 wear down such that the conditioning particles 421 in the region 420 contact the polishing pad. When the conditioning particles 421 in the region 420 are worn away to make the conditioning particles 431 in the region 430 contact the polishing pad, the cutting rate of the polishing pad dresser 400 is above 50%.

Thus, by dividing the conditioning surface into a plurality of regions of different heights and distributing a plurality of conditioning particles over each region, the conditioning particles in the next higher height region will gradually contact the polishing pad and exert a conditioning effect after the conditioning particles in the higher height region are worn. For example, in one example shown in fig. 4, as the conditioning particles 411 in the highest height region 410 wear away, the conditioning particles 421 in the next highest height region 420 may contact the polishing pad. As the conditioning particles 421 in the next highest region 420 wear away, the conditioning particles 431 in the lowest height region 430 contact the polishing pad, thereby extending the useful life and reducing the cost of the polishing pad dresser 400.

The above embodiments of the present invention provide a polishing pad dresser having a longer service life and a lower cost.

Another aspect of the present invention is to provide a chemical mechanical polishing apparatus having a long service life and a low cost.

The chemical mechanical polishing apparatus may include a polishing pad and a polishing pad dresser as described above (e.g., the polishing pad dresser 400, the polishing pad dresser 500, and the polishing pad dresser 600 shown in fig. 4 to 6).

Other implementation details of the cmp apparatus of the present embodiment can refer to the embodiments described in fig. 4 to 6, and are not further expanded herein.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.

Claims

1. A pad dresser having a dressing surface, comprising:

the trimming surface is provided with a plurality of areas with different heights, a plurality of trimming particles are distributed on each area, the trimming surface is positioned at the bottoms of the trimming particles, and the areas continuously cover the trimming surface;

wherein the height differences of the plurality of regions are such that when the polishing pad dresser dresses the polishing pad, the time for which the dressing particles on each region contact the polishing pad is different;

the plurality of regions include a plurality of fan-shaped or arc-shaped regions that diverge outwardly from a center of the dressing face, the plurality of regions including a first region, a second region, and a third region that are sequentially reduced in height, and the dressing particles on the first region, the second region, and the third region gradually decrease in time to contact the polishing pad.

2. The pad conditioner of claim 1 wherein at least one of said plurality of regions includes a plurality of disconnected sub-regions, respectively.

3. The dresser of claim 1, wherein the dressing particles in the dressing surface are uniform in size.

4. The dresser of claim 1, wherein the dressing surfaces have dressing particles of different sizes on different dressing surfaces.

5. The dresser of claim 1, wherein a first region of the plurality of regions having a highest elevation has a greatest proportion of area of the dressing surface.

6. The pad dresser of claim 1, wherein the plurality of zones include a first zone and a second zone of successively decreasing height, the pad dresser having a cut rate of 70% or greater when dressing particles in the first zone wear to cause dressing particles in the second zone to contact the pad.

7. The dresser of claim 1, wherein the plurality of zones include a first zone, a second zone, and a third zone having successively lower heights, wherein the dresser has a cut rate of 70% or greater when the dressing particles in the first zone are worn to cause the dressing particles in the second zone to contact the polishing pad, and wherein the dresser has a cut rate of 50% or greater when the dressing particles in the second zone are worn to cause the dressing particles in the third zone to contact the polishing pad.

8. A chemical mechanical polishing apparatus comprising a polishing pad and the polishing pad dresser of any one of claims 1-7.