CHEMICAL MECHANICAL POLISHING FASTENING DEVICE

Abstract

A chemical mechanical polishing fastening device includes an annular base and a fastening ring. The annular base has a first combining plane, a first inner annular plane, a first jointing plane, and a second inner annular plane. The diameter of the first inner annular plane is greater than that of the second inner annular plane. Two sides of the first inner annular base are connected to the first combining plane and the first jointing plane. Two sides of the first jointing plane are connected to the first inner annular plane and the second inner annular plane. The fastening ring has a second combining plane and an inner annular flange protruded from the second combining plane. The inner annular flange has an outer annular wall to be combined with the first inner annular plane and a top plane to be combined with the first jointing plane.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 103221659 filed in Taiwan, R.O.C. on 2014 Dec. 5, the entire contents of which are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The instant disclosure relates to a chemical mechanical fastening ring, in particular, to a chemical mechanical polishing fastening device applied for polishing semiconductor wafers.

2. Related Art

Chemical mechanical polishing is an essential procedure during manufacturing the semiconductors. If the wafers cannot be polished properly or if scratches left on the wafers, process error would occur during the subsequent lithography procedure like exposure, develop, and etching. In some situation, unrecoverable defects may be formed on the wafers.

In a traditional chemical mechanical polishing device, a fastening ring with a specific thickness faces and is adhered to a base whose shape is corresponding to the ring. In general, the fastening ring is made of polymers and provided for securing a wafer to be polished. During the chemical mechanical polishing procedure, the fastening ring has to sustain the wearing from the high-rotational-speed polishing pad, and fastening ring also has to suffer the erosion from the chemical mechanical polishing liquid. Therefore, after the fastening ring is used for a certain times, the fastening ring has to be replaced by another.

In practice, with a certain possibility, the fastening ring may be failure ahead of the predicted life time (early life failure). The reason is described as follows. During polishing procedure, the chemical mechanical polishing liquid may enter into the interface between the fastening ring and the base, the adhesive in the interface would become small particles by reacting with the polishing liquid and then the particles spread in the polishing liquid. Therefore, during the polishing procedure, the small particles in the polishing liquid would rub against the surface of the wafer to produce scratches on the wafer. As a result, the fastening ring would be failure ahead of the schedule. Accordingly, the replacement times of the fastening ring and the downtime of the production line are increased. Consequently, the material cost and the manufacturing cost of the wafer subcontractors would be increased at the same time.

Therefore, the chemical mechanical polishing liquid would enter the interface between the fastening ring and the base so as to make the fastening ring be early life failure and to cause the increasing of the material cost and the manufacturing cost of the wafer subcontractors.

SUMMARY

In view of these, an exemplary embodiment of the instant disclosure provides a chemical mechanical polishing fastening device comprising an annular base and a fastening ring. The annular base comprises a first combining plane, a first inner annular plane, a first jointing plane, and a second inner annular plane. The first combining plane is parallel to the radial direction of the annular base. The diameter of the first inner annular plane is greater than the diameter of the second inner annular plane. Two sides of the first inner annular base are connected to the first combining plane and the first jointing plane, respectively. Two sides of the first jointing plane are connected to the first inner annular plane and the second inner annular plane, respectively. The fastening ring comprises a second combining plane and an inner annular flange. The second combining plane is parallel to the radial direction of the fastening ring. The second combining plane is combined with the first combining plane of the annular base. The inner annular flange is protruded from the second combining plane. The inner annular flange has an outer annular wall and a top plane. The outer annular wall is combined with the first inner annular plane of the annular base, and the top plane is combined with the first jointing plane.

In one implementation aspect according to the instant disclosure, the distance between the top plane of the inner annular flange and the second combining plane of the fastening ring is defined in the range from 5 mm to 15 mm.

In one implementation aspect according to the instant disclosure, the thickness of the inner annular flange along the radial direction of the fastening ring is defined in the range from 1 mm to 5 mm.

In one implementation aspect according to the instant disclosure, the inner annular flange has an inner annular wall. The inner annular wall of the inner annular flange and the second inner annular plane are aligned at the same level.

In one implementation aspect according to the instant disclosure, a nominal fillet radius of 1.5 mm is defined at the connection between the first jointing plane and the first inner annular plane.

In one implementation aspect according to the instant disclosure, the annular base further comprises a first outer annular plane, a second jointing plane, and a second outer annular plane. The diameter of the first outer annular plane is less than that of the second outer annular plane. Two sides of the first outer annular plane are connected to the first combining plane and the second jointing plane, respectively. Two sides of the second jointing plane are connected to the first outer annular plane and the second outer annular plane, respectively.

In one implementation aspect according to the instant disclosure, the fastening ring comprises an outer annular flange protruded from the second combining plane. The outer annular flange has an inner annular wall and a second top plane. The inner annular wall is combined with the first inner annular plane of the annular base, and the second top plane is combined with the first jointing plane.

In one implementation aspect according to the instant disclosure, the distance between the second top plane of the outer annular flange and the second combining plane of the fastening ring is defined in the range from 4 mm to 10 mm.

In one implementation aspect according to the instant disclosure, the thickness of the outer annular flange along the radial direction of the fastening ring is defined in the range from 1 mm to 4 mm.

In one implementation aspect according to the instant disclosure, the outer annular flange has an outer annular wall. The outer annular wall of the outer annular flange and the second outer annular plane of the annular base are aligned at the same level.

Detailed description of the characteristics and the advantages of the disclosure is shown in the following embodiments, the technical content and the implementation of the disclosure should be readily apparent to any person skilled in the art from the detailed description, and the purposes and the advantages of the disclosure should be readily understood by any person skilled in the art with reference to content, claims and drawings in the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The instant disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus not limitative of the instant disclosure, wherein:

FIG. 1 is a perspective view of a traditional chemical mechanical polishing fastening device;

FIG. 2 is a sectional view along line 1-1 of FIG. 1;

FIG. 3 is an exploded view of a chemical mechanical polishing fastening device of an exemplary embodiment of the instant disclosure;

FIG. 4 is a perspective view of the chemical mechanical polishing fastening device;

FIG. 5 is a sectional view along line 2-2- of FIG. 4; and

FIG. 6 is an operational view of the chemical mechanical polishing fastening device.

DETAILED DESCRIPTION

Please refer to FIG. 1 and FIG. 2, illustrating a perspective view and a sectional view of a typical chemical mechanical polishing fastening device 9 including a base 91, a fastening ring 92, and a jointing plane 93 between the base 91 and the fastening ring 92. Typically, the base 91 and the fastening ring 92 are combined with each other by sticks. Nevertheless, the chemical mechanical polishing liquid would enter into the space between the base 91 and the fastening ring 92 from the jointing plane 93, such that the fastening ring 92 made of polymers (e.g., Polyphenylene sulfide, PPS), may be failed ahead of the predicted time. Therefore, one of the important concepts of the embodiment is to provide a technical solution to prevent the chemical mechanical polishing liquid from entering into the space between the base 91 and the fastening ring 92 during the chemical mechanical polishing procedure.

Please refer to FIG. 3, FIG. 4, and FIG. 5, which provide an exploded view, a perspective view, and a sectional view of a chemical mechanical polishing fastening device 1 according to an exemplary embodiment of the instant disclosure. The chemical mechanical polishing fastening device 1 comprises an annular base 11 and a fastening ring 12. When a wafer is processing the chemical mechanical polishing procedure, the fastening ring 12 faces down to frame the wafer within the fastening ring 12.

The annular base 11 comprises a first combining plane 111, a first inner annular plane 112, a first jointing plane 113, a second inner annular plane 114, a plurality of engaging blocks 118, and a plurality of lock holes 119. The first combining plane 111 is parallel to the radial direction of the annular base 11. The diameter of the first inner annular plane 112 is greater than the diameter of the second inner annular plane 114. As shown in FIG. 3, two sides of the first inner annular plane 112 are connected to the first combining plane 111 and the first jointing plane 113, respectively. In other words, two sides of the first inner annular plane 112 are connected, in a one-to-one relationship, to the first combining plane 111 and the first jointing plane 113. The first jointing plane 113 is substantially parallel to the first combining plane 111, and two sides of the first jointing plane 113 are connected to the first inner annular plane 112 and the second inner annular plane 114, respectively. In other words, two sides of the first jointing plane 113 are connected, in a one-to-one relationship, to the first annular plane 112 and the second inner annular plane 114. Besides, a nominal fillet radius of 1.5 mm to 2.0 mm is defined at the connection between the first jointing plane 113 and the first inner annular plane 112. The engaging blocks 118 are fastened on the first combining plane 111 of the annular base 11 via screws passing through the lock holes 119.

The fastening ring 12 comprises a second combining plane 121, a plurality of engaging holes 128, and an inner annular flange 129. The second combining plane 121 is parallel to the radial direction of the fastening ring 12. The second combining plane 121 is combined with the first combining plane 111 via the engagements between the engaging blocks 118 and the engaging holes 128. Alternatively, the combination between the fastening ring 12 and the annular base 11 may be further enhanced by applying adhesive to the interface between the first combining plane 111 and the second combining plane 121.

The inner annular flange 129 is protruded from the second combining plane 121. The inner annular flange 129 has an outer annular wall 129a and a top plane 129b. As shown in FIG. 5, the outer annular wall 129a is combined with the first inner annular plane 112 of the annular base 11, and the top plane 129b is combined with the first jointing plane 113.

Please refer to FIG. 6, which provides an operational view of the chemical mechanical polishing fastening device 1 according to the exemplary embodiment of the instant disclosure. The chemical mechanical polishing fastening device 1 is fixed to a chemical mechanical polishing apparatus 6 so as to be rotatable relative to a polishing pad (not shown) therebeneath, and a wafer 7 is framed within the fastening ring 12. During the polishing procedure, the chemical mechanical polishing liquid may possibly pass through the space between the wafer 7 and the fastening ring 12 to be accumulated at the back of the wafer 7. In the exemplary embodiment of the instant disclosure, since the fastening ring 12 further comprises the inner annular flange 129, the second combining plane 121 is combined with the first combining plane 111 of the annular base 11, the outer annular wall 129a is combined with the first inner annular plane 112 of the annular base 11, and the top plane 129b is combined with the first jointing plane 113 of the annular base 11. Accordingly, when the wafer 7 is polishing, the chemical mechanical polishing liquid 8 accumulated at the back of the wafer 7 may solely enter the space between the annular base 11 and the fastening ring 12 from the connection between the first jointing plane 113 and the top plane 129b of the inner annular flange 129. However, since the connection between the first jointing plane 113 and the top plane 129b of the inner annular flange 129 is so distant from the back of the wafer 7, the chemical mechanical polishing liquid 8 will generally not enter into the space between the fastening ring 12 and the annular base 11.

As compared with the traditional chemical mechanical polishing device, the fastening ring 12 according to the exemplary embodiment of the instant disclosure would not be failure ahead of the predicted life time. Therefore, the problems in increasing of the material cost and the manufacturing cost of the wafer subcontractors can be solved.

Experiments verify that when the distance between the top plane 129b of the inner annular flange 129 and the second combining plane 121 of the fastening ring 12 is equal to or greater than 5 mm (for example 15 mm), the early failure of the fastening ring 12 can be apparently reduced. When the distance is equal to or greater than 10 mm, the fastening ring 12 is not failure ahead of the scheduled time anymore.

In addition, when the thickness of the inner annular flange 129 along the radial direction of the fastening ring 12 is defined to be equal to or greater than 1 mm, the structural strength of the inner annular flange 129 can be enhanced, and the inner annular flange 129 would not be broken easily. Therefore, the connection between the first jointing plane 113 of the annular base 11 and the top plane 129b of the inner annular flange 129 would have a certain structural strength to bear the shearing stress generated at the connection between the first jointing plane 113 and the top plane 129b during the chemical mechanical polishing procedure. Experiments further verify that when the thickness of the inner annular flange 129 along the radial direction of the fastening ring 12 is defined in the range from 1 mm to 5 mm, the structural strength of the inner annular flange 129 can be enhanced.

In one implementation of the exemplary embodiment, as shown in FIG. 5, the inner annular flange 129 has an inner annular wall 129c. The inner annular wall 129c of the inner annular flange 129 and the second inner annular plane 114 of the annular base 11 are aligned at the same level. If the inner annular wall 129c and the second inner annular plane 114 does not align at the same level, for example, if the area of the top plane 129b is greater than that of the first jointing plane 113, a few chemical mechanical polishing liquids 8 would be accumulated at the top plane 129b of the inner annular flange 129 with an extremely small possibility. Then, with the centrifugal force generated upon the rotation, the chemical mechanical polishing liquid 8 would enter inside the fastening ring 12 through the space between the top plane 129b and the first jointing plane 113. Conversely, in the case that the inner annular wall 129c and the second inner annular plane 114 are aligned at the same level, even when a small amount of chemical mechanical polishing liquid 8 has already been spread to the space between the top plane 129b and the first jointing plane 113, the chemical mechanical polishing liquid 8 does not enter inside the fastening ring 12.

While the instant disclosure has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. For anyone skilled in the art, various modifications and improvements within the spirit of the instant disclosure are covered under the scope of the instant disclosure. The covered scope of the instant disclosure is based on the appended claims.

Claims

1. A chemical mechanical polishing fastening device, comprising:

an annular base, comprising a first combining plane, a first inner annular plane, a first jointing plane, and a second inner annular plane, wherein the first combining plane is parallel to the radial direction of the annular base, the diameter of the first inner annular plane is greater than the diameter of the second inner annular plane, two sides of the first inner annular plane are connected to the first combining plane and the first jointing plane, respectively, two sides of the first jointing plane are connected to the first inner annular plane and the second inner annular plane, respectively; and

a fastening ring, comprising a second combining plane and an inner annular flange, wherein the second combining plane is parallel to the radial direction of the fastening ring, the second combining plane is combined with the first combining plane of the annular base, the inner annular flange is protruded from the second combining plane, the inner annular flange has an outer annular wall and a top plane, the outer annular wall is combined with the first inner annular plane of the annular base, and the top plane is combined with the first jointing plane.

2. The chemical mechanical polishing fastening device according to claim 1, wherein the distance between the top plane of the inner annular flange and the second combining plane of the fastening ring is defined in the range from 5 mm to 15 mm.

3. The chemical mechanical polishing fastening device according to claim 2, wherein the thickness of the inner annular flange along the radial direction of the fastening ring is defined in the range from 1 mm to 5 mm.

4. The chemical mechanical polishing fastening device according to claim 3, wherein the inner annular flange has an inner annular wall, the inner annular wall of the inner annular flange and the second inner annular plane are aligned at the same level.

5. The chemical mechanical polishing fastening device according to claim 4, wherein a nominal fillet radius of 1.5 mm to 2.0 mm is defined at the connection between the first jointing plane and the first inner annular plane.