TWI643703B - A polishing platen for chemical mechanical polishing - Google Patents

Abstract

The present invention provides a polishing pad carrier for chemical mechanical polishing, comprising: a carrier body having a rotation center, a body upper surface and a body side surface, wherein the body upper surface is adjacent to the body side surface; and a plurality of protrusions The portions are evenly distributed on the side surface of the body, wherein each of the protrusions has a convex upper surface, and the upper surface of each of the protrusions is coplanar with the upper surface of the body.

Description

Abrasive pad carrier for chemical mechanical polishing

This invention relates to a polishing pad carrier for chemical mechanical polishing, and more particularly to a polishing pad carrier for improved calibration of chemical mechanical polishing.

When manufacturing a semiconductor device, a process of forming a conductive film on the surface of the wafer, a process of forming a wiring layer by lithography, etching, or the like, and a process of forming an interlayer insulating film on the wiring layer are performed, and the process is performed on the surface of the wafer by these processes. Concavities and convexities formed by a conductor or insulator such as metal. In recent years, in order to increase the density of semiconductor integrated circuits, wiring is becoming finer or multilayer wiring is progressing. However, the technique of flattening the unevenness on the surface of wafers is becoming more and more important.

Generally, a method of flattening the unevenness on the surface of a wafer is a chemical mechanical polishing technique (hereinafter referred to as CMP). CMP is a technique in which a polishing surface of a wafer is pressed against a polishing surface of a polishing pad, and a slurry-like abrasive (hereinafter referred to as a slurry) in which abrasive grains are dispersed is used for polishing. Generally, in the polishing apparatus used in CMP, the polishing pad is adhered to the polishing pad carrier, and the size of the polishing pad is larger than the size of the carrier because the polishing pad is easily removed. However, the current practice is to determine the relative position of the polishing pad and the carrier by the human subject, and thus the center of the polishing pad cannot be accurately aligned with the center of the carrier, so that the polishing pad cannot be in a perfect circle during the grinding process. Rotation, which in turn causes the height between the dots in the wafer after the polishing process The gap increased, flatness was not as good as expected, and product quality was affected.

Therefore, how to improve the existing problems and improve the precision of the polishing process has become a subject of discussion in the present invention.

The present invention provides a polishing pad carrier for chemical mechanical polishing, comprising: a carrier body having a rotation center, a body upper surface and a body side surface, wherein the body upper surface is adjacent to the body side surface; and a plurality of protrusions The portions are evenly distributed on the side surface of the body, wherein each of the protrusions has a convex upper surface, and the upper surface of each of the protrusions is coplanar with the upper surface of the body.

In a preferred embodiment of the present invention, the plurality of protrusions include: a first protrusion, evenly distributed on the side surface of the body, having a first protrusion side surface away from the carrier body; The protrusions are evenly distributed on the body side surface, and have a second protrusion side surface away from the carrier body, wherein the farthest distance between the first side surface and the rotation center is greater than the second side surface and the rotation center The farthest distance.

In a preferred embodiment of the invention, the upper surface of each of the projections has a plurality of graduations.

In a preferred embodiment of the invention, the distance between each of the above scales is between 0.1 and 1 cm.

In a preferred embodiment of the invention, each of the above scales is the same distance.

In a preferred embodiment of the invention, the plurality of projections are integrally formed with the carrier body.

In a preferred embodiment of the invention, the carrier body has a diameter between 70 and 80 cm and a distance between the projection and the center of rotation is less than 43 cm.

Accordingly, the present invention provides a polishing pad carrier for chemical mechanical polishing that provides an easy-to-operate alignment between the polishing pad and the carrier, while also providing polishing pads of different sizes. Different The benchmark solves the problem that the polishing effect caused by the unevenness of the polishing pad or the uneven distribution of the slurry caused by the shaking in the CMP process in the conventional technology further improves the precision of the CMP process and the product yield.

1‧‧‧ Grinding platform

2‧‧‧Substrate platform

3‧‧‧ bracket

11‧‧‧ polishing pad carrier

12‧‧‧ polishing pad

13‧‧‧Brush supply pipe

21‧‧‧Substrate carrier

22‧‧‧Substrate

111‧‧‧ Vehicle body

111a‧‧‧Revolution Center

111s‧‧‧ body side surface

111t‧‧‧ body upper surface

112‧‧‧ protruding parts

112t‧‧‧Upper surface of the projection

121‧‧‧ trench

131‧‧‧Blurry

1121‧‧‧First bulge

1121s‧‧‧First bulge side surface

1122‧‧‧second bulge

1122s‧‧‧Second bulge side surface

1121p, 1122p‧‧‧ endpoint

S12‧‧‧Grinding surface

The above and other objects, features, and advantages of the present invention will become more apparent from the aspects of the invention. FIG. 2 is a schematic view showing the structure of a CMP machine according to the embodiment shown in FIG. 1 when the CMP process is performed; FIG. 3A is a polishing pad according to an embodiment of the present invention. Figure 3B-3C is a side view of the relative position of the different size polishing pads placed in the polishing pad carrier according to the embodiment of Figure 3A; and Figures 4A-4B are drawn in accordance with different embodiments of the present invention A schematic view of the polishing pad carrier in a top view.

The invention provides a polishing pad carrier for chemical mechanical polishing, which has an easy-to-operate alignment reference between the polishing pad and the carrier, thereby enabling the polishing pad and the carrier to rotate stably and smoothly during the grinding process. The slurry is evenly distributed on the polishing pad to achieve a better grinding effect. The above and other objects, features, and advantages of the present invention will become more apparent and understood.

As shown in FIG. 1 , the CMP machine includes a polishing platform 1 and a substrate platform 2 . The polishing pad carrier 11 is located on the polishing platform 1 , and each polishing pad carrier 11 is provided with a polishing pad 12 corresponding to each polishing. The pad 12 is provided with a slurry supply tube 13 for supplying the slurry 131 required in the CMP process between the polishing pad 12 and the surface of the substrate to be polished. Polishing pad 12 and polishing pad The strips 11 are fixed by adhesion. The polishing surface S12 of the polishing pad 12 has a plurality of grooves 121 for allowing the slurry 131 to stay and evenly distributed on the polishing surface S12 of the polishing pad 12. The substrate platform 2 includes a substrate carrier 21 for fixing the substrate in the CMP process, and the bracket 3 is located at approximately the center of the polishing platform 1 and the substrate platform 2 and corresponding to each other for supporting the substrate platform 2 including the substrate carrier 21 on the polishing platform. 1 on. The CMP machine has other component structures, such as waste water recovery tanks, drainage lines, detection holes, wafer changers, etc., which are similar to the prior art and therefore are not described or illustrated.

In the CMP process, as shown in FIG. 2, after the substrate carrier 21 is loaded with the substrate 22, the surface of the substrate 22 to be polished is in contact with the polishing surface S12 of the polishing pad 12, on the polishing surface S12 covered with the slurry 131. Perform CMP. 3A and 4A-4B are top plan views of a polishing pad carrier 11 according to various embodiments of the present invention, and FIGS. 3B and 3C are polishing pads 12 of different sizes drawn according to the embodiment of FIG. 3A. A side view of the relative position of the pad carrier 11 afterwards.

In the first embodiment of the present invention, as shown in the top view of the polishing pad carrier 11 shown in FIG. 3A, the polishing pad carrier 11 has a carrier body 111 and a plurality of projections 112. The carrier body 111 is circular and has a diameter of between 70 and 80 cm, and has a rotation center 111a (in this embodiment, the rotation center 111a of the carrier body 111 is its center), and a body upper surface 111t. And a body side surface 111s, wherein the body upper surface 111t is adjacent to the body side surface 111s, and the body upper surface is 111t is a surface to which the polishing pad 12 is adhered. The radius of the polishing pad carrier 11 will be smaller than the radius of the polishing pad 12 to facilitate unloading and replacing the polishing pad 12. The plurality of protrusions 112 are evenly distributed on the body side surface 111s of the carrier body 111, and each of the protrusions 112 has a protrusion upper surface 112t, the protrusion upper surface 112t and the body upper surface 111t Coplanar. In order to enable the polishing pad carrier 11 to avoid sloshing during rotation during the CMP process, the distribution of the slurry 131 is affected, and the polishing effect is poor. Therefore, the protrusions 112 are formed in pairs on the diameter of the carrier body 111. Both ends, And it is formed in a plurality of and/or symmetrically on the body side surface 111s of the carrier body 111. In this embodiment, in order to cooperate with the use of different sizes of the polishing pad 12, and at the same time achieve the purpose of effectively aligning and adhering the polishing pad carrier 11 and the polishing pad 12, as shown in FIG. 3A, the projections 112 have different sizes. The first plurality of protrusions 1121 and the plurality of second protrusions 1122 are sized, wherein the size of the first protrusions 1121 is smaller than the size of the second protrusions 1122.

In this embodiment, each of the first protrusions 1121 has a first protrusion side surface 1121 s away from the body side surface 111s, and the first protrusion side surface 1121s has a rotation with the carrier body 111. The distal end point 1121p of the center 111a, the size of the first protrusion portion 1121 is determined by the shortest linear distance from the end surface 1121p and the body side surface 111s; likewise, each second protrusion 1122 has a distance from the body side surface 111s. The second protrusion side surface 1122s, and the second protrusion side surface 1122s has a most distal point 1122p with the center 111a of the carrier body 111, and the second protrusion 1122 is dimensioned via the body side surface The shortest straight line distance of 111s is determined. Therefore, the size of the first protruding portion 1121 is smaller than the size 1122 of the second protruding portion, that is, the shortest linear distance from the end point 1121p of the first protruding portion 1121 to the body side surface 111s is smaller than the end point of the second protruding portion 1122. The shortest linear distance from 1122p to the body side surface 111s. The sizes of the first protrusions 1121 and the second protrusions 1122 can be adjusted as needed. For example, the minimum size can be between 0.1 and 1 cm, and the difference of the size of the different protrusions can be between 0.1 and 1 cm. between. In this embodiment, the first projection 1121 has a size of 0.5 cm, and the second projection 1122 has a size of 1 cm. In various embodiments of the present invention, the protrusions 112 may include third protrusions that are formed on the body side surface 111s of the carrier body 111 on average and/or symmetrically, and have different from the first protrusions 1121 and The size of the second protrusion 1122. Although the present embodiment uses the circular arc shape as the shape of the convex portion 112, the shape thereof can be adjusted depending on the condition, and in another embodiment of the present invention, the shape is rectangular.

In addition, the first protruding portion 1121 and the second protruding portion 1122 are respectively The average portion is on the body side surface 111s, so that sloshing when the polishing pad carrier 11 is rotated during the CMP process can be avoided, and different calibration standards can be provided for the different sizes of the polishing pad 12. 3B-3C is a side view of the polishing pad 12 adhered to the polishing pad carrier 11, according to the size of the polishing pad 12, the side of the polishing pad 12 and the first protruding side of the polishing pad carrier 11 The surface 1121s or the second protrusion side surface 1122s are aligned, and the polishing pad 12 is simply and effectively adhered to the polishing pad carrier 11 to solve the problems of the prior art and effectively improve the precision of the CMP process. And the convex upper surface 112t of the structural protrusion 112 is coplanar with the upper surface 111t of the body, so in the CMP process, when the polishing slurry 131 is pulled out by the polishing pad 12 and the polishing pad carrier 11, it will not It remains between the projection 112 and the carrier body 12, affecting the CMP effect.

In the second and third embodiments of the present invention, as shown in the top view of the polishing pad carrier 11 shown in Figs. 4A and 4B, the same reference numerals will be used for the same elements as those of the foregoing embodiment for simplicity of explanation. The polishing pad carrier 11 has a carrier body 111, a plurality of protrusions 112, a rotation center 111a (in this embodiment, the rotation center 111a of the carrier body 111 is a center thereof), a body upper surface 111t, and a body side. The relative position of each element is the same as that of the previous embodiment, and will not be described herein. The plurality of protrusions 112 are evenly distributed on the body side surface 111s of the carrier body 111, and each of the protrusions 112 has a protrusion upper surface 112t, the protrusion upper surface 112t and the body upper surface 111t Coplanar. In order to enable the polishing pad carrier 11 to avoid sloshing during rotation during the CMP process, the distribution of the slurry 131 is affected, and the polishing effect is poor. Therefore, the protrusions 112 are formed in pairs on the diameter of the carrier body 111. Both ends, and a plurality of them are symmetrically formed on the body side surface 111s of the carrier body 111. The polishing pad carriers 11 provided in the second and third embodiments each have four evenly distributed projections 112, and the projections 112 can have different graduations for use with different sizes of the polishing pads 12. As shown in FIG. 4A, the protrusions 112 are marked or marked with a plurality of scales of different sizes, and each scale can be represented by different colors, and the same color represents the same research. The size of the sanding pad; or as shown in FIG. 4B, the projections 112 are depicted or marked with different numbers, and the same reference numerals represent the same polishing pad size. The shape and the scale pitch of the projections 112 can be adjusted as appropriate, as shown in the embodiment of FIG. 4A as a circular arc, and FIG. 4B is nearly square compared to FIG. 4A. The scale spacing can be between 0.1 and 1 cm. In the second embodiment, the minimum scale represents the size of the polishing pad 12 having a radius of 0.5 cm more than the polishing pad carrier 11, and the scale pitch is 0.5 cm; in the third embodiment, the minimum scale (the scale in Fig. 4B) 1) The size of the polishing pad 12 representing a radius of more than a half of the polishing pad carrier 11 is a half turn.

The polishing pad carrier provided by the present invention may be integrally formed between the protruding portion 112 and the carrier body 111, or the protruding portion may be additionally formed on the carrier body 111. And in order to achieve a better effect in the grinding process, the size of the protruding portion 112 is preferably less than 8 cm. For example, the carrier body 111 having a diameter of 70 cm is used in combination with the most distal point of the protruding portion 112. The linear distance of the center 111a of the carrier body 111 is preferably less than 43 cm.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an abrasive pad carrier for chemical mechanical polishing that provides an easy alignment of the polishing pad to the carrier while providing different polishing pads of different sizes. The benchmark is to solve the problem that the polishing effect caused by the unevenness of the polishing pad caused by the rotation offset or the sloshing of the polishing pad in the CMP process in the conventional technology is further improved, and the precision and product yield of the CMP process are further improved.

Although the present invention has been disclosed above by way of example, it is not intended to limit the invention. Anyone having ordinary knowledge in the field can make some changes and refinements without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (7)

A polishing pad carrier for chemical mechanical polishing, comprising: a carrier body having a rotation center, a body upper surface and a body side surface, wherein the body upper surface is adjacent to the body side surface; and a plurality of The protrusions are evenly distributed on the side surface of the body, wherein each of the plurality of protrusions has a convex upper surface, and each of the protrusion upper surfaces is coplanar with the upper surface of the body. The polishing pad carrier of claim 1, wherein the plurality of protrusions comprise: a first protrusion, evenly distributed on the side surface of the body, having a first distance away from the carrier body a protrusion side surface; a second protrusion portion evenly distributed on the body side surface, having a second protrusion side surface away from the carrier body, wherein the first side surface and the rotation center are the most The distance is greater than the furthest distance of the second side surface from the center of rotation. The polishing pad carrier of claim 1, wherein the upper surface of each of the plurality of protrusions has a plurality of scales. The polishing pad carrier of claim 3, wherein the distance between each of the plurality of scales is between 0.1 and 1 cm. The polishing pad carrier of claim 3, wherein each of the plurality of scales has the same distance between them. The polishing pad carrier of claim 1, wherein the plurality of protrusions are integrally formed with the carrier body. The polishing pad carrier of claim 1, wherein the carrier body has a diameter of between 70 and 80 cm and a distance between the projection and the rotation center is less than 43 cm.