TWM459065U - Polishing pad and polishing system - Google Patents

Abstract

A polishing pad and a polishing system, suitable for polishing a workpiece, are provided. The workpiece has a central track on the polishing pad. The polishing pad includes a polishing layer, a plurality of annular grooves and at least one radial extending groove. The polishing layer has a rotating center and an arranging center, wherein the rotating center and the arranging center have a distance therebetween. The annular grooves, disposed in the polishing layer, are arranged concentrically around the arranging center. The radial extending groove, disposed in the polishing layer, has a plurality of intersections with the central track.

Description

Abrasive pad and grinding system

The present invention relates to a polishing pad and a polishing system, and more particularly to a polishing pad and a polishing system that provide better polishing uniformity.

As the industry advances, flattening processes are often adopted as processes for producing various components. In the flattening process, the chemical mechanical polishing process is often used by the industry. Generally, the chemical mechanical polishing process is performed by supplying a polishing liquid having a chemical mixture onto a polishing pad, applying a pressure to the abrasive article to press it onto the polishing pad, and allowing the abrasive article and the polishing pad to move relative to each other. . By the mechanical friction generated by the relative motion and the chemical action of the polishing liquid, the surface layer of the partially polished object is removed, and the surface thereof is gradually flattened to achieve the purpose of planarization.

The conventional polishing pad comprises a plurality of concentric grooves which are used to accommodate or exclude debris or by-products generated during the grinding process, and which make it easier to polish the object from the circular polishing pad when the grinding process is completed. Remove. Generally, when grinding is performed, the polishing pad rotates along the center of rotation, and the abrasive object that is in contact with the surface of the polishing pad rotates with the axis passing through the center point as a rotation axis. However, due to the concentric circular grooves on a conventional polishing pad, the center of the arrangement and the rotation of the polishing pad The center of the transfer overlaps. Therefore, during the grinding process, the center of the abrasive article is almost fixedly passed through the groove on the polishing pad or the abrasive surface. Therefore, the center of the abrasive article typically has the lowest or highest abrasive rate (depending on whether the center of the abrasive article is fixed at the groove or the abrasive surface) compared to the vicinity of the center of the abrasive article.

Concentric grooves on another conventional polishing pad have an arrangement center that does not overlap the center of rotation of the polishing pad and has a spacing therebetween. However, during the grinding process, due to the rotation of the abrasive article, the number of times the center of the abrasive article passes through the groove and the polished surface is less than the number of times the groove and the polished surface pass through the vicinity of the center of the abrasive article. Therefore, the uniformity of the grinding near the center portion of the abrasive article is still poor. The problem of uneven grinding rate of the abrasive article may further affect the reliability of the component.

The present invention provides a polishing pad and a polishing system that achieves better polishing uniformity on the surface of the abrasive article.

The present application proposes a polishing pad suitable for grinding abrasive articles having a central trajectory on the polishing pad. The polishing pad includes an abrasive layer, a plurality of annular grooves, and at least one radially extending groove. The polishing layer has a center of rotation and an arrangement center, and a space is provided between the center of rotation and the center of the arrangement. The annular groove is located in the abrasive layer and is arranged concentrically centered on the center of the arrangement. The radially extending trench is located in the abrasive layer and the radially extending trench has a plurality of intersections with the central track.

This creation proposes a grinding system suitable for grinding abrasive articles, grinding The object has a central trajectory on the polishing pad. The grinding system includes a carrier and a polishing pad. The carrier is used to hold the abrasive article. The polishing pad is attached to a grinding platform having a rotational direction. The polishing pad includes an abrasive layer, a plurality of annular grooves, and at least one radially extending groove. The polishing layer has a center of rotation and an arrangement center, and a space is provided between the center of rotation and the center of the arrangement. The annular groove is located in the abrasive layer and is arranged concentrically centered on the center of the arrangement. The radially extending trench is located in the abrasive layer and the radially extending trench has a plurality of intersections with the central track.

Based on the above, the polishing pad of the present invention has an annular groove that is non-concentrically arranged with the center of rotation, and the radially extending groove has a plurality of intersections with the center track, so that the center of the abrasive object can be increased during the grinding process. The number of times at the groove and the abrasive surface to provide better grinding uniformity.

In order to make the above features and advantages of the present invention more comprehensible, the following embodiments are described in detail with reference to the accompanying drawings.

100‧‧‧ grinding system

102‧‧‧ Vehicles

104‧‧‧Abrased objects

110‧‧‧ polishing pad

112‧‧‧Abrasive layer

114‧‧‧Loading station

116‧‧‧Round groove

118‧‧‧radial extension groove

118a, 118b‧‧‧ endpoint

A-A’‧‧‧ cut line

B‧‧‧ spacing

C1‧‧‧ Rotation Center

C2‧‧‧ alignment center

C3‧‧‧Abrasion Object Center

T‧‧‧Center track of abrasive objects

Radius of R‧‧‧ polishing pad

D‧‧‧Rotation direction

1A is a top plan view of a polishing system in accordance with an embodiment of the present invention.

Fig. 1B is a schematic cross-sectional view taken along line A-A' of Fig. 1A.

2 is a top plan view of a polishing system of another embodiment of the present invention.

3 is a top plan view of a polishing system of another embodiment of the present invention.

1A is a top plan view of a polishing system in accordance with an embodiment of the present invention. Fig. 1B is a schematic cross-sectional view taken along line A-A' of Fig. 1A. In order to clearly show the polishing pad of the present embodiment, FIG. 1A only marks the polishing layer and the groove, and FIG. 1B details the polishing pad and all of the constituent members. Referring to FIG. 1A and FIG. 1B, the polishing system 100 of the present embodiment is used for grinding the abrasive article 104. The polishing system 100 includes a carrier 102 and a polishing pad 110. The carrier 102 is disposed above the polishing pad 110 for holding the abrasive article 104 above the polishing pad 110. The grinding system 100 further includes a carrier 114 for carrying the polishing pad 110. The polishing pad 110 is fixed to the stage 114 having the rotational direction D, for example, by adhesive means or by suction.

In this embodiment, the carrier 114 is a circular turntable. When the stage 114 rotates, the polishing pad 110 fixed to the surface of the stage 114 is driven to rotate the polishing pad 110 at the same time. The carrier 102 is used to press the abrasive article 104 against the surface of the polishing pad 110, and a relative movement between the polishing pad 110 and the abrasive article 104 is generated by the rotation of the carrier 114. The abrasive article 104 having a relatively flat surface is produced by the abrasive pad 110 rubbing against the surface to be abraded of the abrasive article 104 to remove the uneven skin of the abrasive article 104.

In the present embodiment, the polishing pad 110 includes an abrasive layer 112, a plurality of annular grooves 116, and at least one radially extending groove 118. The polishing layer 112 has a rotation center C1 and an arrangement center C2. The rotation center C1 is, for example, located at the center point of the polishing layer 112, and the polishing layer 112 is rotated in the rotation direction D around the rotation center C1.

The polishing layer 112 is composed, for example, of a polymer substrate, and the polymer substrate can be Either polyester, polyether, polyurethane, polycarbonate, polyacrylate, polybutadiene, or the rest via a suitable thermosetting resin (thermosetting) A resin substrate or the like synthesized from a thermoplastic resin. The abrasive layer 112 may comprise, in addition to the polymeric substrate, a conductive material, abrasive particles, or a dissolvable additive in the polymeric substrate.

In the present embodiment, a plurality of annular grooves 116 are located in the polishing layer 112, with the center C2 as the center point of the distribution, and distributed outward from the center of the alignment C2 toward the edge of the polishing layer 112. The annular groove 116 can be a circular groove, an elliptical groove, a polygonal groove, a wavy annular groove, an irregularly shaped annular groove, or a combination thereof. According to this embodiment, the annular groove 116 is a concentric groove, and the spacing between the adjacent two annular grooves 116 is substantially equal, but does not limit the scope of the present invention. The annular groove 116 is primarily used to provide transport and distribution of the slurry.

The rotation center C1 and the arrangement center C2 of the polishing layer 112 are not offset from each other, and a pitch b is provided between the rotation center C1 and the arrangement center C2. Thus, during the grinding process, the annular groove 116 and the abrasive layer 112 exhibit a non-concentric relative motion state with each other. In this way, it can be reduced that the center of the abrasive article C3 is fixedly in contact with the groove on the polishing pad 110 or the abrasive surface. Therefore, the polishing rate of the center of the abrasive article C3 and the vicinity of the center of the abrasive article can be made uniform to provide better polishing uniformity. In the present embodiment, the pitch b is, for example, 2 to 20 mm. When the pitch b is larger, the degree to which the surface alignment center C2 deviates from the rotation center C1 is larger.

The polishing pad 110 of the present embodiment further includes at least one radially extending trench 118 in the polishing layer 112. The abrasive article 104 has a central track T on the polishing pad 110 that is the trajectory that the abrasive article center C3 passes through the polishing pad 110 and passes over the polishing pad 110. In other words, when the abrasive article 104 is rotationally polished on the polishing pad 110, the center of the abrasive article C3 where it passes over the polishing pad 110 forms a central trajectory T. The radially extending groove 118 has a plurality of intersections with the center track T. That is, the radially extending groove 118 corresponds at least to the position of the center of the abrasive article C3, and the distribution area of the radially extending groove 118 is, for example, a region corresponding to the center of the abrasive article C3 ± 40 mm. In one embodiment, the radius of the polishing pad 110 is R, and the position of the center of the abrasive article C3 is, for example, at least corresponding to a radius (R/2) of the one-half of the polishing pad 110, and the distribution area of the radially extending groove 118 is, for example. It is R/2±40 mm. During the grinding process, through the rotation of the polishing pad 110, the radially extending groove 118 increases the number of times the center of the abrasive article C3 passes through the groove and the polishing surface, and reduces the groove passing through the vicinity of the center of the abrasive article. And the difference in the number of times of the polished surface, so that a better polishing uniformity can be obtained.

The radially extending trench 118 can be an open trench having two end points (118a, 118b), such as a curved trench, as shown in Figure 1A. One end of the radially extending groove 118 is located at a smaller radius of the polishing pad 110 and the other end is located at a larger radius of the polishing pad 110. The radially extending grooves 118 are spirally distributed outward from the center of rotation C1 of the polishing layer 112. In one embodiment, the radially extending grooves 118 have a curved direction from the inside to the outside, and the direction of the bending is the same as the direction of rotation D of the polishing pad 110. For example, the rotation direction D of the polishing pad 100 is positive (ie, counterclockwise), and the diameter The direction of the bend to the extension groove 118 is also positive (i.e., counterclockwise). However, this creation is not limited to this. According to other embodiments, the direction of curvature of the radially extending grooves 118 may also be selected to be negative (i.e., clockwise) to provide a different flow field distribution for the slurry, as shown in FIG. The aforementioned open radial extending groove 118 is illustrated by a curved shape. However, this creation is not limited to this. According to other embodiments, the open radial extension grooves 118 may also be linear grooves, polygonal grooves, undulating grooves, irregular open grooves, or combinations thereof.

In another embodiment, the radially extending trenches 118 can be closed trenches without end points, such as circular radially extending trenches 118, as shown in FIG. A circular radially extending groove 118 is located in the abrasive layer 112 and has a plurality of intersections with the central trajectory T of the abrasive article 104. That is, the circular radially extending groove 118 corresponds at least to the position of the center of the abrasive article C3, and the distribution of the circular radially extending groove 118 is, for example, a region corresponding to the center of the abrasive article C3 ± 40 mm. In one embodiment, the radius of the polishing pad 110 is R, and the position of the center of the abrasive article C3 is, for example, at least corresponding to a radius (R/2) of the polishing pad 110, the circular radially extending groove 118. The distribution area is, for example, R/2±40 mm. During the grinding process, through the rotation of the polishing pad 110, the circular radially extending groove 118 increases the number of times the grinding object center C3 passes through the groove and the grinding surface, and reduces the passage of the vicinity of the center of the abrasive article. The difference in the number of times between the groove and the polished surface makes it possible to obtain a better polishing uniformity. The aforementioned closed radial extending groove 118 is exemplified by a circular shape. However, this creation is not limited to this. According to other embodiments, the enclosed radially extending grooves 118 may also be elliptical grooves, polygonal grooves, wavy annular grooves, irregular shapes Enclosed grooves, or a combination thereof.

The comparison between the polishing pad 110 and the conventional polishing pad in the present embodiment is as follows. Under the same grinding conditions, the difference in the polishing rate of the polishing pad 110 of the present invention is greatly improved. The polishing pad 110 of the present invention is superior to the conventional polishing pad. Has a better uniformity.

The number of annular grooves 116 and radially extending grooves 118 illustrated in the foregoing embodiments is for illustrative purposes only, and the present disclosure does not limit the number of annular grooves 116 and radially extending grooves 118. Further, the radially extending grooves 118 are distributed outwardly around the center of rotation C1, and may be selected to be distributed outwardly around the center C2 of the arrangement, or may be centered on another point that does not overlap the center of rotation C1 and the center of arrangement C2. Outward distribution. Moreover, if there are a plurality of radially extending grooves 118, the radially extending grooves 118 are not limited to have the same extension length, and may have different extension lengths, and even these radial extension grooves 118 may be selected as An extension of the same inner and outer diameter or an extension of different inner and outer diameters.

The groove in the polishing pad of this creation can be selected mechanically (for example) If using a milling machine equipped with a drill or saw blade, mold transfer method, or etching method (for example, using chemical etching or laser processing), but not limiting the scope of this creation, you can also choose other forms of formation. Make grooves.

The polishing system 100 of the present embodiment is used for grinding abrasive articles, and can be applied to the manufacture of components such as semiconductors, integrated circuits, MEMS, energy conversion, communication, optics, storage disks, and displays. Grinding process. Therefore, the abrasive article 104 used for fabricating the above-mentioned components may be a semiconductor wafer, a IIIV wafer, a storage component carrier, a ceramic substrate, a polymer substrate, a glass substrate, etc., but is not intended to limit the scope of the present invention. .

In summary, the polishing pad of the present invention has an annular groove arranged in a non-concentric circle with the center of rotation, and the radially extending groove has a plurality of intersection points with the center track, so that the grinding object can be added during the grinding process. The number of passes through the groove and the surface of the center to provide better grinding uniformity.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any person having ordinary knowledge in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of protection of this creation is subject to the definition of the scope of the patent application.

100‧‧‧ grinding system

104‧‧‧Abrased objects

110‧‧‧ polishing pad

112‧‧‧Abrasive layer

116‧‧‧Round groove

118‧‧‧radial extension groove

118a, 118b‧‧‧ endpoint

A-A’‧‧‧ cut line

B‧‧‧ spacing

C1‧‧‧ Rotation Center

C2‧‧‧ alignment center

C3‧‧‧Abrasion Object Center

T‧‧‧Center track of abrasive objects

Radius of R‧‧‧ polishing pad

D‧‧‧Rotation direction

Claims (28)

A polishing pad adapted to grind a polishing object, the abrasive article having a central track on the polishing pad, the polishing pad comprising: an abrasive layer having a center of rotation and an alignment center, the center of rotation and the center of the arrangement Having a spacing; a plurality of annular grooves in the polishing layer, the annular grooves are arranged concentrically centered on the center of the arrangement; and at least one radially extending groove is located in the polishing layer, and the The radially extending groove has a plurality of intersections with the central trajectory. The polishing pad of claim 1, wherein the spacing is between 2 and 20 mm. The polishing pad of claim 1, wherein the annular groove is a circular groove, an elliptical groove, a polygonal groove, a wavy annular groove, an irregular annular groove, or combination. The polishing pad of claim 1, wherein the radially extending groove is an open radially extending groove. The polishing pad of claim 4, wherein the open radial extending groove is a linear groove, a polygonal groove, a wave groove, an irregular open groove, or a combination thereof. The polishing pad of claim 1, wherein the radially extending groove is a closed radial extending groove. The polishing pad of claim 6, wherein the closed radial The extension grooves are circular grooves, elliptical grooves, polygonal grooves, wavy annular grooves, irregular closed grooves, or a combination thereof. The polishing pad of claim 1, wherein the radially extending groove is outwardly distributed centering on the center of rotation, the center of the arrangement, or another point that does not overlap the center of rotation and the center of the arrangement. The polishing pad of claim 1, wherein the radially extending groove corresponds at least to a center of the abrasive article. The polishing pad of claim 9, wherein the radially extending groove is a region corresponding to a center of the abrasive article by ±40 mm. The polishing pad of claim 1, wherein the radially extending groove is at least corresponding to a radius of one half of the polishing pad. The polishing pad of claim 11, wherein the radially extending groove is a region corresponding to a radius of ±40 mm of the polishing pad. The polishing pad of claim 1, wherein the radially extending grooves are plural, and each of the radially extending grooves has the same extension length or has a different extension length. The polishing pad of claim 1, wherein the radially extending grooves are plural, and each of the radially extending grooves has an extension of the same inner diameter and outer diameter or has different inner diameters and outer diameters. The extension of the path. A grinding system suitable for grinding an abrasive article, the polishing system comprising: a carrier for holding the abrasive article: a polishing pad fixed on a polishing platform having a rotation direction, the abrasive article having a central track on the polishing pad, the polishing pad comprising: an abrasive layer having a center of rotation and an arrangement center, the center of rotation Between the alignment centers, a plurality of annular grooves are disposed in the polishing layer, the annular grooves are arranged concentrically around the center of the arrangement; and at least one radially extending groove is located in the polishing In the layer, and the radially extending trench has a plurality of intersections with the central track. The grinding system of claim 15 wherein the spacing is between 2 and 20 mm. The grinding system of claim 15, wherein the annular groove is a circular groove, an elliptical groove, a polygonal groove, a wavy annular groove, an irregularly shaped annular groove, or combination. The grinding system of claim 15 wherein the radially extending groove is an open radially extending groove. The grinding system of claim 18, wherein the open radial extending groove is a linear groove, a polygonal groove, a wavy groove, an irregular open groove, or a combination thereof. The grinding system of claim 15 wherein the radially extending groove is a closed radially extending groove. The grinding system of claim 20, wherein the closed radial extending groove is a circular groove, an elliptical groove, a polygonal groove, a wavy ring A groove, an irregularly shaped closed groove, or a combination thereof. The polishing system of claim 15, wherein the radially extending groove is outwardly distributed centering on the center of rotation, the center of the arrangement, or another point that does not overlap the center of rotation and the center of the arrangement. The grinding system of claim 15 wherein the radially extending groove is at least corresponding to a center of the abrasive article. The grinding system of claim 23, wherein the radially extending groove is a region corresponding to a center of the abrasive article by ±40 mm. The grinding system of claim 15 wherein the radially extending groove is at least corresponding to a radius of the one half of the polishing pad. The grinding system of claim 25, wherein the radially extending groove is a region corresponding to a radius of one-half of a radius of the polishing pad of ±40 mm. The grinding system of claim 15, wherein the radially extending grooves are plural, each of the radially extending grooves having the same extension length or having different extension lengths. The grinding system of claim 15, wherein the radially extending grooves are plural, each of the radially extending grooves having an extension of the same inner diameter and outer diameter or having different inner diameters and outer diameters The extension of the path.