KR200375396Y1 - Polishing pad for CMP - Google Patents

Abstract

The present invention relates to a polishing pad for CMP, in which an improved groove pattern is formed to smoothly polish the surface of an object including a semiconductor wafer or various substrates. A first groove pattern including a plurality of formed first X-axis grooves and a plurality of first Y-axis grooves formed at regular intervals in the X-axis direction while being perpendicular to the first X-axis grooves; A second X-axis groove formed at a plurality of intervals in the Y-axis direction and a plurality of second Y-axis grooves formed at a predetermined interval in the X-axis direction and orthogonal to the second X-axis groove, and interposed between the first groove patterns Second groove patterns forming mutually equal spacing; And a third X-axis groove pattern and the third X-axis groove pattern formed in a plurality of equal intervals between the first X-axis groove pattern of the first groove pattern and the second X-axis groove pattern of the second groove pattern. A third groove portion including a plurality of third X-axis groove patterns formed at equal intervals between the first Y-axis groove pattern of the first groove pattern and the second Y-axis groove pattern of the second groove pattern while being orthogonal to each other; The pattern is formed on the upper surface.

Description

Polishing pad for chemical mechanical polishing {Polishing pad for CMP}

The present invention relates to a polishing pad for CMP, and more particularly, to a polishing pad for CMP, in which an improved groove pattern is formed to smoothly polish the surface of an object including a semiconductor wafer or various substrates.

In general, semiconductor devices having a high integration trend require precisely overlaying the interlayer circuit patterns in response to a reduction in circuit line width. In this case, the circuit pattern between the layers is formed by partial deposition and repetitive performance of unit processes such as growth and etching. As a result, the surface layer of the circuit pattern has a partially stepped shape. As such, the stepped portion of the circuit pattern and the boundary portion thereof make it difficult to contact between circuit patterns that are subsequently stacked, resulting in deterioration or failure of the finished product due to alignment error.

Therefore, the wafer until fabrication of the semiconductor device has at least one planarization process in order to eliminate the cause of the defect.

The planarization process described above may include, for example, etch-back or chemical mechanical polishing (CMP).

Among these, the CMP process is a chemical-mechanical polishing (CMP) process in which the surface of the object is softened by a chemical reaction and simultaneously removed by a physical method.

As shown in FIG. 1, the polishing pad 10 performing the CMP process is fixedly installed on an upper surface of the surface plate 12 that rotates at a high speed in a horizontal state.

On the surface of the polishing pad 10, the continuous supply of the slurry S is made to the rotation center part. At this time, the supplied slurry (S) flows in a shape that is diffused to the surface layer of the polishing pad 10 by centrifugal force, and eventually leaves the edge portion.

The wafer W is opposed to the polishing pad 10 by the polishing head 14. The wafer W reciprocates the section between the center and the edge of the polishing pad 10 while rotating at a high speed while the target surface is pressed close to the surface of the polishing pad 10 or by a predetermined force. At this time, the wafer W is maintained in a horizontal state with respect to the surface of the polishing pad 10 by the gimbal (16) provided in the polishing head (14). By the above-described method, the target surface of the wafer W is polished by chemical and physical action.

Polishing process for the wafer (W) is intended to implement the flatness of the surface of the wafer (W), the condition for this is required to uniformly distribute the slurry (S) on the surface of the polishing pad (10).

As shown in FIGS. 1 and 2, the surface plate 12 rotates at a high speed so as to uniformly distribute the slurry S on the surface of the polishing pad 10, and compensates for the difference in centrifugal force due to the high speed rotation. Thus, grooves G are formed to control the flow rate of the slurry S. In addition, the polishing pad 10 includes pores in multiple layers, and the pores are continuously exposed to the surface in the conditioning process or the polishing process. The pores are involved in uniformly distributing the slurry S by temporarily receiving the slurry S flowing by the centrifugal force and letting it out again.

As a result, the result of the CMP process is affected by the polishing uniformity due to the material properties, surface conditions, and the like of the polishing pad 10 in contact with the target surface of the wafer W.

The polishing pad 10 shown in FIG. 2 is a plan view of a polishing pad according to the prior art, in which concentric grooves G having different diameters are formed on the surface of the polishing pad 10 at regular intervals.

As the concentric grooves G are formed as shown in FIG. 2, the slurry supplied to the polishing pad 10 moves along the grooves G by the action of centrifugal force to friction between the target surface of the wafer W and the polishing pad 10. It is supplied between the surfaces to perform the polishing on the wafer (W). These grooves G are arranged at a constant width and depth and at regular intervals between each other to influence the supply, discharge and distribution of the slurry.

However, the center portion and the edge portion of the polishing pad 10 corresponding to the target surface of the wafer W and the intermediate portion therebetween not only have a difference in physical polishing action due to the centrifugal force but also the flow of the slurry S. There is also a significant difference in the distribution. Here, assuming that the slurry is uniformly distributed over the entire surface of the polishing pad 10, the respective portions of the polishing pad 10 have different physical forces acting on the surface to be polished of the wafer W. Therefore, in order for the polished surface of the wafer W to be uniformly polished as a whole, the physical action at each part of the polishing pad 10 and the distribution of the slurry thereof need to be managed efficiently.

3 is a Republic of Korea Utility Model Registration No. 273586 has been filed and disclosed by the present applicant. The polishing pad 20 of FIG. 3 has an edge portion of the wafer W due to a difference in slurry flow for each section of the polishing pad 10 and its distribution density by concentric grooves G in the conventional polishing pad 10. In order to solve the problem of grinding more than the center and the problem of oversupply of the slurry (S).

The polishing pad 20 of FIG. 3 forms a first groove G1 having an orthogonal shape in the X-axis and Y-axis directions on the polishing surface, and again in the X-axis and Y-axis directions, ie, between the first grooves G1. A second groove G2 orthogonal to the first groove G1 in a shape parallel to the first groove G1 and having a depth different from that of the first groove G1 is formed.

The above-described polishing pad 20 of FIG. 2 is provided with a groove pattern for efficiently managing the physical action and the distribution of the slurry thereof over the entire surface, but requires detailed management in response to a more miniaturized semiconductor technology, Accordingly, the groove pattern of the polishing pad 20 is required to be improved.

An object of the present invention is to improve the groove pattern formed on the polishing pad to control the flow of slurry so that the surface of an object such as a wafer is polished uniformly.

A characteristic configuration of the polishing pad for chemical mechanical polishing according to the present invention for achieving the above object, the X-axis while orthogonal to the first X-axis groove and the plurality of first X-axis groove formed at regular intervals in the Y-axis direction A first groove pattern including a plurality of first Y-axis grooves formed at regular intervals in a direction; A second X-axis groove formed at a plurality of intervals in the Y-axis direction and a plurality of second Y-axis grooves formed at a predetermined interval in the X-axis direction and orthogonal to the second X-axis groove, and interposed between the first groove patterns Second groove patterns forming mutually equal spacing; And a third X-axis groove pattern and the third X-axis groove pattern formed in a plurality of equal intervals between the first X-axis groove pattern of the first groove pattern and the second X-axis groove pattern of the second groove pattern. A third groove portion including a plurality of third X-axis groove patterns formed at equal intervals between the first Y-axis groove pattern of the first groove pattern and the second Y-axis groove pattern of the second groove pattern while being orthogonal to each other; The pattern is formed on the upper surface.

At least one end of the second and third groove patterns may be formed to be inside a predetermined area at an edge.

Hereinafter, a polishing pad for CMP according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 4, a first groove pattern 40, a second groove pattern 42, and a third groove pattern 44 are formed in the polishing pad 30 of the CMP facility for a semiconductor wafer according to the present invention.

First, the first groove pattern 40 of the polishing pad 30 described above is a first X-axis groove 40X formed at regular intervals in the Y-axis direction along the polishing surface and a first gap formed at a constant interval in the X-axis direction. Y-axis groove 40Y is included. The first X-axis groove 40X and the first Y-axis groove 40Y are perpendicular to each other to form a grid shape.

The grid shape described above may be selectively applied in a square shape or a rectangular shape in consideration of polishing efficiency according to a manufacturer's intention.

The width and depth of the first X-axis groove 40X and the first Y-axis groove 40Y of the first groove pattern 40 are approximately 0.8 to 2.0 mm, and the width is preferably 1.5 ± 0.05 mm. To form, the depth can be made by forming 0.8 ~ 1.5mm.

The second groove pattern 42 of the polishing pad 30 has a second X-axis groove 42X formed at regular intervals in the Y-axis direction and a second Y-axis groove 42Y formed at regular intervals in the X-axis direction. It includes. The second X-axis groove 42X and the second Y-axis groove 42Y are perpendicular to each other to form a grid shape.

On the other hand, at least one or more of the above-described second groove pattern 42 includes the first groove pattern 40 at equal intervals between the first groove patterns 40. Accordingly, at least one arrangement of the second X-axis grooves 42X of the second groove pattern 42 is formed between the adjacent first X-axis grooves 40X, and the first Y-axis grooves 40Y adjacent to each other. The second Y-axis groove 42Y of the second groove pattern 42 forms at least one or more arrangements between the holes.

Each second groove pattern 42 forms a rectangular or square grid pattern, as described above, in parallel with each of the first groove patterns 40.

In addition, the width and depth of the second X-axis groove 42X and the second Y-axis groove 42Y of the second groove pattern 42 are formed about 0.5 to 1.2 mm, and preferably the width is 1.0 ± 0.05 mm. The depth can be set to about 0.5-1.0 mm.

In addition, the distances P1 and P2 of the grooves of the first groove pattern 40 and the second groove pattern 42 may be variously determined according to the manufacturer's intention.

In addition, at the intersection of the second X-axis groove 42X and the second Y-axis groove 42Y of the second groove pattern 42, the through hole 46 through which the slurry supplied to the polishing surface of the polishing pad 30 is eluted. ) Is formed, the through hole 46 may be formed to have a diameter of 0.8mm ~ 1.2mm, preferably a diameter of 1 ± 0.05mm.

On the other hand, the third groove pattern 44 of the polishing pad 30 is formed between the above-described first groove pattern 40 and the second groove pattern 42 or between the second groove pattern 42 adjacent to each other. Specifically, the third groove pattern 44 is formed between the first X-axis groove 40X of the first groove pattern 40 and the second X-axis groove 42X of the second groove pattern 42 or adjacent to each other. A plurality of third X-axis grooves 44X are formed between the two X-axis grooves 42X so as to be maintained at a constant interval therebetween. In addition, the third groove pattern 44 may be formed between the first Y-axis groove 40Y of the first groove pattern 40 and the second Y-axis groove 42Y of the second groove pattern 42 or adjacent to each other. A plurality of third Y-axis grooves 44Y are formed between the Y-axis grooves 42Y so as to be maintained at a constant interval therebetween.

Preferably, the third X-axis groove 44X and the third Y-axis groove 44Y of the third groove pattern 44 are orthogonal to each other. On the other hand, like the first groove 40 and the second groove 42 described above, it can be formed to have a rectangular or square grid shape.

In addition, the width and depth of the third X-axis groove 44X and the third Y-axis groove 44Y of the third groove pattern 44 are about 0.1 to 0.3 mm, and preferably the width and depth are 0.1 ±. It is formed in 0.05 mm, Preferably the above-mentioned depth is about 0.4-0.8 mm.

The spacing distance P3 of each groove of the third groove pattern 44 may be variously determined according to the manufacturer's intention.

When the slurry is supplied to the polishing pad 30 by the same configuration as in the embodiment of FIG. 4 described above, the slurry described above is formed by the first groove pattern 40, the second groove pattern 42, and the third groove pattern 44. It is spread along the supply side.

In this case, the depth and the width of the first groove pattern 40, the second groove pattern 42, and the third groove pattern 44 described above are the first groove pattern 40, the second groove pattern 42, and the third groove. It is preferable to form the pattern 44 in the same or gradually smaller in each order. According to the difference described above, the first groove pattern 40 constitutes the main flow passage of the slurry, and the second groove pattern 42 constitutes the secondary flow passage of the slurry.

The third groove pattern 44 having a smaller depth and width than the first groove pattern 40 and the second groove pattern 42 forms a detailed flow passage of the slurry.

As described above, the flow of the slurry may be effectively controlled by the groove patterns 40, 42, and 44 formed on the polishing pad 30, and an improvement in the flatness of an object surface such as a wafer may be expected. have.

On the other hand, in the edge portion of the polishing pad 30 in order to control the outflow of the slurry, the end of the third groove pattern 44 from the upper edge of the polishing pad 30 to the inner portion of a predetermined range as shown in FIG. It may be implemented to limit the madness, or to limit the end of the second groove pattern 42 in a predetermined range from the edge of the polishing pad 30 in addition to the third groove pattern 44 as shown in FIG. 6. Do.

Each of these embodiments is not limited to performing an operation on one side of the object from the rotational center of the polishing pad as in the CMP facility illustrated in FIG. 1 described in the prior art, so that the supply of slurry is eluted from the surface plate to the upper side. Of course, it can be applied more effectively in response to a sheet-fed CMP equipment having a diameter of about 0.5 to 30 mm larger than the equipment or wafer.

According to the present invention, the polishing pad is provided with a first groove, a second groove, and a third groove to ensure uniformity and fluidity of the slurry supplied to the polishing surface, thereby reducing waste of the slurry, and uniformly smoothing the polishing surface. It can be effective.

1 is a cross-sectional view schematically illustrating a state in which a polishing pad is applied to a general CMP facility.

FIG. 2 is a plan view illustrating a groove pattern according to the related art formed on an upper surface of the polishing pad illustrated in FIG. 1.

3 is a plan view for explaining the technology disclosed in the Utility Model Registration No. 20-0273586 filed and registered by the present applicant.

4 is a plan view showing a preferred embodiment of a polishing pad according to the present invention.

5 is a plan view showing another embodiment of a polishing pad according to the present invention.

Figure 6 is a plan view showing another embodiment of a polishing pad according to the present invention.

Explanation of symbols on the main parts of the drawings

10, 20, 30: polishing pad

12: surface plate 14: polishing head

16: gimbal 18: conditioning head

40: first groove pattern 42: second groove pattern

44: third groove pattern 46: through hole

Claims (3)

A first groove pattern including a plurality of first X-axis grooves formed at a predetermined interval in the Y-axis direction and a plurality of first Y-axis grooves formed at regular intervals in the X-axis direction and orthogonal to the first X-axis grooves; A second X-axis groove formed at a plurality of intervals in the Y-axis direction and a plurality of second Y-axis grooves formed at a predetermined interval in the X-axis direction and orthogonal to the second X-axis groove, and interposed between the first groove patterns Second groove patterns forming mutually equal spacing; And Orthogonal to the third X-axis groove pattern and the third X-axis groove pattern formed in a plurality of equal intervals between the first X-axis groove pattern of the first groove pattern and the second X-axis groove pattern of the second groove pattern. And a third groove pattern including a plurality of third X-axis groove patterns formed at equal intervals between the first Y-axis groove pattern of the first groove pattern and the second Y-axis groove pattern of the second groove pattern. Polishing pad for CMP, characterized in that formed on the upper surface respectively. The method of claim 1, The second groove pattern is a polishing pad for CMP, characterized in that the through-hole is further formed at the intersection of the second X-axis groove and the second Y-axis groove to the elution of the slurry from the bottom. The method of claim 1, At least one of the second and third groove patterns is a polishing pad for the CMP, characterized in that the end end is limited to extend from the edge of the upper surface to a predetermined range.