KR100224724B1 - Polishing pad conditioner its using method in CMP equipment - Google Patents

Abstract

The present invention relates to a polishing pad conditioner and a conditioning method of a CMP apparatus capable of conditioning a surface state of a polishing pad in a chemical mechanical polishing process. To this end, the present invention comprises a main body composed of an alloy of nickel and steel which is formed on top of the polishing pad and can cover an area corresponding to the radius of the polishing pad, and a surface in contact with the surface of the polishing pad in the body. It provides a polishing pad conditioner of CMP equipment characterized in that it comprises a conditioning means for varying the conditioning effect at the center and the edge of the polishing pad by varying the density of the diamond particles to be attached. It also provides a conditioning method using the same. Therefore, by maintaining the surface state of the polishing pad in a straight line, it is possible to implement a polishing pad conditioner and conditioning method of the CMP equipment that can solve the problem of the polishing rate drop in the center of the wafer.

Description

Polishing pad conditioner for chemical mechanical polishing equipment and its use method {Colishing pad conditioner its using method in CMP equipment}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical-mechanical polishing (hereinafter referred to as CMP) apparatus of a semiconductor manufacturing process, and more particularly, to a polishing pad of a CMP apparatus capable of conditioning the surface state of the polishing pad in a CMP process. A conditioner and a conditioning method.

As the degree of integration of semiconductor devices increases, the multi-layered wiring process is put to practical use, and accordingly, the importance of global planarization of the interlayer film is further emphasized. Recently, as a means of global flattening, the planarization method using CMP equipment has begun to attract attention.

CMP equipment is a chemical mechanical planarization method using both a mechanical method using a polishing pad and an abrasive and a chemical method of polishing a wafer by a chemical component in a slurry solution. In general, such a CMP apparatus attaches a polishing pad to a circular flat plate table rotating at the bottom, supplies an abrasive, that is, a slurry in a liquid state, to a predetermined area on the upper surface of the polishing pad, and applies the slurry to the upper portion of the polishing pad. The wafer fixed to the rotating wafer carrier has a working principle in that the surface of the wafer is flattened by friction by rotating in close contact with the surface.

In the planarization process using such a CMP device, the surface state of the CMP device polishing pad depends on characteristics such as uniformity, planarization rate, and evenness of surface particles to be polished. It is an important variable that affects a lot. That is, as the polishing pad is continuously polished, the polishing pad or other foreign matters are caught or damaged on the surface of the polishing pad, thereby deteriorating the surface of the polishing pad to a state different from the initial surface state and deteriorating the stability of the planarization process. It will work.

Accordingly, various types of polishing pad conditioners and conditioning methods using the same have been proposed in order to continuously maintain the surface state of the polishing pad when the wafer is continuously planarized using the CMP apparatus.

A representative polishing pad conditioning method recently used is a method of conditioning the surface of a polishing pad by attaching diamond particles to a circular flat plate made of an alloy of nickel and steel to rub the surface of the polishing pad.

The polishing pad conditioning apparatus and method in the prior art will be described with reference to the accompanying drawings.

1 to 6 are diagrams for explaining a polishing pad conditioner of the conventional CMP equipment.

Referring to FIG. 1, a process in which the surface of the wafer 3 is polished by the frictional effect while the wafer 3 closely attached to the upper end of the polishing pad 1 rotating clockwise 5 is rotated clockwise. Shows. Here, the part where the wafer 3 adheres to the polishing pad 1 was divided into A, B, and C areas. Here, region A and region C represent an edge portion of the wafer, and region B represents a central portion of the wafer.

Referring to FIG. 2, it is a graph for explaining the surface state of the polishing pads in areas A, B, and C shown in FIG. In detail, the Y axis represents the thickness of the polishing pad, and the X axis represents the distance from the center to the edge of the polishing pad. In the area A, the wear occurs less because the area of the wafer is attached to the polishing pad, but in the area B, the wear occurs more severely than the area A because the wafer is attached to the polishing pad. do. In addition, the area C wears to a thickness similar to that of the area A. As a result, the surface state of the 'V' shape is exhibited from the center to the edge of the polishing pad.

3 is a plan view showing that the circular polishing pad conditioner 7 is performing conditioning on the polishing pad 1. In detail, the circular polishing pad conditioner 7 is in close contact with the top of the polishing pad 1 to condition the surface state of the polishing pad 1 while reciprocating from the center to the edge of the polishing pad 1. . Reference numeral 11 denotes the direction in which the polishing pad conditioner is reciprocating. At this time, the polishing pad conditioner is supported by the polishing pad conditioner arm 9.

4 is a plan view when the circular polishing pad conditioner 7 described above is enlarged. In order to explain the structure of the polishing pad conditioner, a predetermined area 13 of the polishing pad conditioner 7 will be enlarged and described in detail with reference to a plan view and a cross-sectional view thereof.

FIG. 5 is a plan view when the predetermined area of the polishing pad conditioner of FIG. 4 is enlarged. FIG. In detail, amorphous diamond particles 17 made by crushing diamond are attached to the polishing pad conditioner main body 15 having a material composed of an alloy of nickel and steel, by electroplating.

FIG. 6 is a sectional view when the predetermined area of the polishing pad conditioner of FIG. 4 is enlarged. The diamond particles 17 are attached to the main body 15 made of an alloy of nickel and steel in an electroplated form, and protrude from the main body 15 to a predetermined height. It is a means for conditioning the surface of the pad.

The problem in the above-mentioned prior art is that the polishing pad conditioner performs conditioning without considering the state of the polishing pad, so that the wear of the polishing pad due to the polishing of the wafer is 'V' shaped from the center to the edge of the polishing pad. Because of this, the polishing rate is dropped in the center of the wafer in close contact with the recessed region of the 'V' shape, the process stability is reduced.

An object of the present invention is to provide a polishing pad conditioner of the CMP equipment that can improve the shape of the polishing pad conditioner to improve the problem that the polishing rate is reduced in the center of the wafer to be polished on the polishing pad.

Another object of the present invention is to provide a conditioning method using a polishing pad conditioner of the CMP apparatus.

1 to 6 are diagrams for explaining a polishing pad conditioner and conditioning method of a conventional CMP equipment.

7 to 9 are diagrams for explaining a polishing pad conditioner of the CMP apparatus according to a preferred embodiment of the present invention.

10 is a view illustrating a polishing pad conditioning method of a CMP apparatus according to a preferred embodiment of the present invention.

11 and 12 are views for explaining a polishing pad conditioner of the CMP apparatus according to a modification of the present invention.

In order to achieve the above technical problem, in the first embodiment, a main body composed of an alloy of nickel and steel which is configured on an upper portion of a polishing pad and can cover an area corresponding to a radius of the polishing pad, and the main body CMP equipment characterized in that it comprises a conditioning means for varying the conditioning effect at the center and the edge of the polishing pad by varying the density of the diamond particles attached to the surface in contact with the surface of the polishing pad in A polishing pad conditioner is provided.

Preferably, the density of the diamond particles of the conditioning means is suitably configured to be lower than the density at both ends, and the difference in density is suitably in the range of 1 to 80%.

According to a preferred embodiment of the present invention, the main body is preferably in the shape of a rod, and the diamond particles are suitably having a size of 1 to 999 µm.

In order to achieve the above technical problem, the present invention, in a modification, may be configured on the polishing pad and cover an area corresponding to the radius of the polishing pad, and the area of the surface contacting the polishing pad is wide at both ends and the central portion. In the main body composed of a narrow alloy of nickel and steel, the density of diamond particles attached to the surface in contact with the surface of the polishing pad in the body is uniform, so that the conditioning effect is different at the center and the edge of the polishing pad. It provides a polishing pad conditioner of CMP equipment characterized in that it comprises a conditioning means capable of.

Preferably, the difference between the areas of both ends and the center portion in the surface in contact with the polishing pad of the main body is in the range of 1 to 80%.

In accordance with another aspect of the present invention, there is provided a second embodiment, in which a wafer is adhered and polished on a rotating polishing pad, and a polishing pad conditioner is conditioned on the polishing pad on the polishing pad. In the polishing pad conditioning method of the CMP equipment having a second step of performing (conditioning), The polishing pad conditioner of the second step, the rod-shaped polishing pad condition that can cover the length of the radius of the polishing pad It provides a polishing pad conditioning method characterized in that the condition of the conditioning (conditioning) at the center and the edge of the polishing pad by varying the density of the diamond particles attached to the surface to be adhered to you using different .

It is suitable to use the density of the diamond particles attached to the center of the polishing pad conditioner to be lower than the density of both ends to change the density of the diamond particles for each part of the conditioner in close contact with the polishing pad. Is preferably in the range of%

According to the present invention, it is possible to implement a polishing pad conditioner of the CMP equipment and a polishing pad conditioning method using the same, which can improve the shape of the polishing pad conditioner to improve the problem of the polishing rate falling at the center of the wafer polished on the polishing pad. Can be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example 1

7 to 9 are diagrams for explaining a polishing pad conditioner of the CMP apparatus according to a preferred embodiment of the present invention.

7 is a cross-sectional view when the polishing pad conditioner 102 according to the present invention is positioned on the polishing pad 100. Here, when the wafer is polished, the polishing pad conditioner 102 is intended to be in close contact with the polishing pad 100, but will be described with a slight distance for better understanding.

The polishing pad 100 is initially a flat shape having no center, but as described in the related art, the wafer is continuously polished to have a 'V' shape and the center portion has a recessed surface.

Although the polishing pad conditioner 102 is configured in a small circle in the prior art, in the present invention, the polishing pad conditioner 102 may cover the radius of the wafer or may cover the radius area of the polishing pad 100 with an error range of ± 1 inch. It is a standard that can be. The reason for the error range of ± 1 inch is to improve the flatness of the wafer by conditioning the polishing pad 100, which is intended in the present invention, even if the conditioner 102 of the polishing pad is configured to such an error range. This is because the effect can be achieved. And the shape is also composed of a rod shape, not circular. Here, the polishing pad conditioner 102 covering the radius area of the polishing pad is one of the key ideas for achieving the object of the present invention. It adjusts the density of the diamond particles attached to each of the parts (A, B, C, D, E in the figure) to the polishing pad conditioner 102 having the improved shape by the central portion (C) of the polishing pad. This is because different polishing effects can be achieved at the edges A and E which are both ends. That is, in the A and E regions, the density of the diamond particles is densified to increase the conditioning, and the C region reduces the density of the diamond particles, thereby slightly suppressing the conditioning. Thus, the surface state of the polishing pad 100 is generally reduced. Because it can be made into a flat plane. Due to the above action, the problem of lowering the polishing rate at the center of the wafer in the related art can be solved.

8 is a plan view illustrating a polishing pad conditioner according to the present invention. For reference, A, B, C, D, and E, which represent predetermined portions of the polishing pad conditioner, correspond to those in FIG. In detail, an amorphous diamond particle 108 made by grinding diamond in conditioning means constituted on the surface in contact with the polishing pad in the main body 106 of the polishing pad conditioner composed of an alloy of nickel and steel is formed. It is attached in the form of electroplating or the like. Here, it is suitable to use the size 114 of the diamond particles in the range of 1 to 999 mu m. In addition, the preferred size of the polishing pad conditioner according to the present invention is that the length of the short side, that is, width 110 is 1 ~ 99mm, length 112 may be equal to the radius of the polishing pad or have an error of ± 1 inch. have.

9 is a cross-sectional view when the polishing pad conditioner shown in FIG. 8 is cut in the longitudinal direction. For reference, here again, A, B, C, D, and E, which indicate predetermined portions of the polishing pad conditioner, correspond to those in FIG. In detail, the diamond particles 108 are attached to the polishing pad conditioner main body 106 composed of an alloy of nickel and steel to form the protrusion 116 having a predetermined height. The protrusion 116 in which the diamond particles 108 have a predetermined height serves as a means for conditioning the surface of the polishing pad.

Here, the density difference of the diamond particles 108 in the A, B, C, D, and E portions of the figure is one of other important means for achieving the object of the present invention. That is, the C portion that is in close contact with the polishing pad in the area where the wear is relatively high and is recessed is a low density of the diamond particles 108, so the conditioning is weak, and the A and E areas that are in contact with the polishing pad in the area where the wear is reduced. The diamond particles 108 are formed with a high density to sufficiently condition, and at the B and D sites, the condition is performed with an intermediate density, so that the polishing pad has a flat surface shape with a uniform thickness as a whole. It acts to improve the problem of falling polishing rate at the center. The density difference of diamond grains in the A, B, C, D, and E regions is compared with the highest A and E, so that the lowest C region is comprised in the range of 1 to 80%, effectively achieving the object of the present invention. It's a range that can be done.

Example 2

10 is a plan view illustrating a polishing pad conditioning method of the CMP equipment using the polishing pad conditioner of the CMP equipment according to the preferred embodiment of the present invention.

Referring to FIG. 10, a polishing pad conditioner 102 of the CMP apparatus according to the present invention is installed on the polishing pad 100, and is a plan view when the conditioning is performed while polishing the wafer 104. In the conventional polishing pad conditioning method, a wafer is adhered to and polished on an upper portion of a rotating polishing pad, and a circular polishing pad conditioner reciprocates from the center to the edge of the polishing pad at the top of the polishing pad, thereby removing the polishing pad. Conditioning methods have been used.

However, in the present invention, a rod-shaped polishing pad conditioner 102 capable of covering the radius of the non-circular polishing pad on the top of the rotating polishing pad 100 is supported by the polishing pad conditioner arm 103. It can be said that it is fixed and operated without reciprocating motion. The fixed operation of the polishing pad conditioner 102 is due to the size of the polishing pad conditioner having the size of the radius of the polishing pad.

In addition, since the polishing pad conditioner of the present invention varies the density of the diamond particles adhered to each part of the surface in close contact with the polishing pad, the polishing pad conditioner may adhere to the surface (C) of the polishing pad conditioner that is in close contact with the surface where the wear of the polishing pad occurs a lot. The diamond particles have a low density, which increases or decreases the conditioning effect. On the surface (A, E) of the polishing pad conditioner in close contact with the center and the edges, the diamond particles have a high density. To increase the conditioning effect. The difference in density of the diamond grains can be effectively achieved in the range of 1 to 80% compared with the lowest one where the lowest difference is high.

The control of the density of the diamond particles by maintaining the surface state of the polishing pad as a straight line having a uniform thickness as a whole, it is possible to solve the problem of the prior art that the polishing rate at the center of the wafer to improve the stability of the process.

Variant

11 and 12 are diagrams for explaining the modified example according to the present invention.

In the first embodiment of the present invention, the shape of the polishing pad conditioner is configured in the shape of a rod, and each part is separated into A, B, C, D, and E to be conditioned at the center and the edge of the polishing pad by varying the density. Although the object of the present invention was achieved by increasing the effect, the effect sought in the present invention can be achieved even by modifying the shape of the polishing pad conditioner without modifying the density to adjust the density.

That is, the length may be left as it is, and the width of the conditioning means, which is the surface in contact with the polishing pad, may be adjusted for each part (A, B, C, D, E). At this time, the density of the diamond particles is kept uniform. Briefly, it is a method of adjusting the area while maintaining a uniform density of diamond particles for each part of the polishing pad conditioner.

Referring to Figure 11, the size of the polishing pad conditioner body 200 is configured so that the length is equal to the radius of the polishing pad or have an error range of ± 1 inch, the area in contact with the polishing pad as the conditioning means, That is, it is the top view when the diamond particle 202 which has a fixed density is affixed after setting width differently by site | part (A, B, C, D, E).

In this case, by varying the conditioning effect at the center and the edge of the polishing pad, which is an object of the present invention, the polishing rate is reduced at the center of the wafer by maintaining the surface state of the polishing pad as a flat straight line. Can be.

12 is a cross-sectional view when the polishing pad conditioner shown in FIG. 11 is cut in the longitudinal direction. In this case, the conditioning is controlled by the area to which the diamond particles are attached, not the density of the diamond particles, so that the diamond particles attached to the main body are constant for each part (A, B, C, D, E).

The present invention is not limited to the above-described embodiments, and it is apparent that many modifications are possible by those skilled in the art within the technical spirit to which the present invention belongs.

Therefore, according to the present invention, by maintaining the surface state of the polishing pad in a flat flat shape having a constant thickness, it is possible to implement the polishing pad conditioner and conditioning method of the CMP equipment that can solve the problem of the polishing rate is dropped at the center of the wafer .

Claims (10)

A main body composed of an alloy of nickel and steel which is formed on an upper portion of the polishing pad and can cover an area corresponding to a radius of the polishing pad; And And a conditioning means for varying the conditioning effect at the center and the edge of the polishing pad by varying the density of the diamond particles attached to the surface in contact with the surface of the polishing pad in the main body. Conditioning pad conditioner for equipment. The polishing pad conditioner of claim 1, wherein the density of the diamond particles of the conditioning means is lower than the density of both ends. 3. The polishing pad conditioner of claim 2, wherein the center portion of the conditioning means is configured to have a density lower than the density of both ends thereof at a difference of 1 to 80%. The polishing pad conditioner of claim 1, wherein the main body has a rod shape. The polishing pad conditioner of claim 1, wherein the diamond particles have a size of 1 to 999 µm. A main body configured at an upper portion of the polishing pad and covering an area corresponding to a radius of the polishing pad, the area of the surface contacting the polishing pad having a wide area at both ends and a narrow alloy at the center thereof; And CMP, characterized in that it comprises a conditioning means that the density of the diamond particles attached to the surface in contact with the surface of the polishing pad in the main body is uniform to vary the conditioning effect at the center and the edge of the polishing pad Conditioning pad conditioner for equipment. 7. The polishing pad conditioner of claim 6, wherein a difference between the areas of both ends and the center portion in a surface in contact with the polishing pad of the main body is in a range of 1 to 80%. A first step in which the wafer is adhered and polished on the rotating polishing pad, A polishing pad conditioning method of a CMP apparatus, comprising: a polishing pad conditioner performing a conditioning on the polishing pad on the polishing pad; The polishing pad conditioner of the second step, Using a rod-shaped polishing pad conditioner that can cover the length of the radius of the polishing pad, Polishing pad conditioning method, characterized in that by varying the density of the diamond particles attached to the surface to be in close contact with the conditioning (conditioning) effect in the center portion and the edge portion of the polishing pad. The polishing pad conditioning method of claim 8, wherein the changing of the density of the diamond particles forms a density of the diamond particles formed at the center of the polishing pad conditioner lower than the density of both ends. 9. The polishing pad conditioning method of claim 8, wherein the difference of the density of the diamond particles is 1 to 80% lower than the density of both ends in the rod shape.