KR19980040061A - Polishing pad conditioner for chemical mechanical polishing equipment and its use method - 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 flat plate composed of an alloy of nickel and steel and having a length in the range of ± 1 inch compared to the radius of the polishing pad, and by varying the density of adhesion according to the portion of the flat plate, It provides a polishing pad conditioner of the CMP equipment, characterized in that it comprises a diamond particles that can improve the conditioning effect at the edge portion. 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 of chemical mechanical polishing equipment and method of using the same.

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. Among these, a new technology has attracted attention as a planarization method using CMP equipment.

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 lower part thereof, and supplies an abrasive, that is, a slurry in a liquid state to a predetermined area of the upper surface of the polishing pad, and applies the slurry by rotating centrifugal force. The wafer fixed by the rotating wafer carrier on the upper part of the polishing pad has a working principle in which the surface of the wafer is flattened by its frictional effect.

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, the polishing pad has a stable stability of the planarization process using the CMP equipment as the polishing pad is continuously polished and the abrasive pad or other kinds of foreign substances are caught or damaged on the surface of the polishing pad, thereby changing to a different state from the initial surface state. It acts as a cause of deterioration.

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

A typical polishing pad conditioning method used recently is a method of conditioning the surface state of a polishing pad by attaching diamond particles to a circular flat plate made of an alloy of nickel and steel and rubbing 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 portion in which the wafer is in close contact with the rotating polishing pad 1 was divided into A, B, and C regions. 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 plate 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 flat plate 15 made of an alloy of nickel and steel in an electroplated form to protrude from the flat plate 15 to a predetermined height, and the diamond particles 17 having these raised heights are provided. Is a means for conditioning the surface of the polishing 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 polishing pad conditioning method of a CMP apparatus using a polishing pad conditioner of the CMP apparatus according to the present invention.

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.

* Description of the main symbols in the drawing

100: polishing pad, 102: polishing pad conditioner,

104: wafer, 106: polishing pad conditioner plate,

106: diamond particles, 108: the size of the diamond particles,

110: width of the polishing pad conditioner plate, 112: length of the polishing pad conditioner plate,

In order to achieve the above technical problem, in the first embodiment, the present invention is made of an alloy of nickel and steel and has a length of ± 1 inch compared to the radius of the polishing pad, and according to the part of the plate. It provides a polishing pad conditioner of CMP equipment, characterized in that it comprises a diamond particles that can improve the conditioning effect in the center and the edge of the polishing pad by varying the density to be attached.

Preferably, varying the density to be adhered to according to the portion of the plate is preferably configured such that the central portion of the polishing pad conditioner is lower than the density of both ends.

It is preferable to comprise the said center part lower than the density of both ends in 1 to 80% of range.

The polishing pad conditioner is preferably in the form of a rectangle.

It is preferable that the said rectangular shape is 1-99 mm in length of a short side (width).

The diamond particles preferably have a size of 1 to 999 µm.

In order to achieve the above technical problem, the present invention is a modification, a flat plate composed of an alloy of nickel and steel, the length is ± 1 inch compared to the radius of the polishing pad, the width of both ends is wide and the width of the center is narrow And diamond particles which can improve the conditioning effect at the center and the edge of the polishing pad by using diamond particles which are attached to the flat plate at a constant density. to provide.

The width of both ends is wide and the width of the center is narrow, but the ratio of the width is preferably changed in the range of 1 to 80%.

In accordance with another aspect of the present invention, a wafer is adhered and polished on a rotating polishing pad in a second embodiment, and the polishing pad conditioner is polished while reciprocating from the top to the edge of the polishing pad. A polishing pad conditioning method of a CMP apparatus comprising conditioning a pad, wherein the polishing pad conditioner uses a non-circular polishing pad conditioner having a length in a range of ± 1 inch of the polishing pad radius. In addition, the polishing pad conditioner is a polishing characterized in that to improve the conditioning (conditioning) characteristics in the center portion and the edge portion of the polishing pad by varying the density of diamond particles for each part of the conditioner in close contact with the polishing pad in a fixed state A pad conditioning method is provided.

To vary the density of the diamond particles for each part of the conditioner in close contact with the polishing pad, the density of the diamond particles adhering to the center portion of the polishing pad conditioner is preferably lower than the density of both ends.

The density of the diamond particles adhering to the center portion of the polishing pad conditioner is lower than the density of both ends, and it is preferable to use the formed particles with a difference in the range of 1 to 80%.

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 polishing is performed, the polishing pad conditioner is in close contact with the polishing pad 100, but is illustrated with a slight distance for better understanding.

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

The polishing pad conditioner 102 has a circular shape smaller than the radius of the polishing pad 100 in the related art. However, in the present invention, the polishing pad conditioner 102 has a circular shape equal to the radius of the wafer or has an error range of ± 1 inch. It is constructed in the form of a rectangle. It is one of the key ideas to achieve the object of the present invention to configure the polishing pad conditioner 102 to a length equal to the radius of the polishing pad or having an error range of ± 1 inch. By adjusting the density of the diamond particles attached to the polishing pad conditioner (102, A, B, C, D, E in the figure) to the improved shape of the polishing pad conditioner, By somewhat suppressing the conditioning in the C region, as a whole it plays an important role to make the surface state of the polishing pad 100 in a constant plane.

Due to the above operation, the problem of lowering the polishing rate at the center of the wafer in the prior 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, amorphous diamond particles 108 made by crushing diamond are attached to a flat plate 106 of a polishing pad conditioner made of an alloy of nickel and steel, 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 specification of the polishing pad conditioner according to the present invention is that the length of the short side, that is, the width 110 is 1 to 99 mm, and the length 112 is preferably in the range of ± 1 inch of the polishing pad length.

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 protrusion 116 having a predetermined height on a polishing pad conditioner plate made of an alloy of nickel and steel. 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. That's the range you can do

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, the polishing pad conditioner 102, which is not circular at the top of the rotating polishing pad 100 and has a length of ± 1 inch compared to the radius of the polishing pad, is the polishing pad conditioner arm 103. It is supported by) and can be characterized as operating fixedly 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 particles is in a range that can be achieved differently in the range of 1 to 80%, as compared with the lowest point is a range that can effectively achieve the object of the present invention.

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 formed in a rectangular shape, and each part is separated into A, B, C, D, and E, and the density is varied to condition at the center and the edge of the polishing pad. Although the object of the present invention has been achieved by increasing, the shape of the polishing pad conditioner can be adjusted without changing the density, and the width can be adjusted for each part (A, B, C, D, E). . At this time, the density of diamond grains is kept constant.

That is, the area of the polishing pad conditioner is adjusted while keeping the density of the diamond particles uniform for each part of the polishing pad conditioner.

Referring to FIG. 11, the size of the polishing pad conditioner plate 200 is ± 1 inch in length compared to the polishing pad, and the width is different for each portion of the plate (A, B, C, D, E). It is a top view at the time of attaching the diamond particle 202 which has a fixed density after a structure.

In this case, the diamond particles on the surface of the polishing pad conditioner that are in close contact with the center and the edge of the polishing pad are increased, thereby increasing the conditioning effect at the center and the edge of the polishing pad to achieve the present invention. Maintaining the flat shape in the shape of a child can solve the problem of dropping the polishing rate at the center of the wafer.

12 is a cross-sectional view when the polishing pad conditioner shown in FIG. 11 is cut in the longitudinal direction. In this case, since the conditioning is controlled by the area to which the diamond particles are attached, not the density of the diamond particles, the diamond particles attached to the flat plate 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 (11)

A plate composed of an alloy of nickel and steel and having a length in the range of ± 1 inch compared to the radius of the polishing pad; And Polishing pad conditioner of the CMP equipment characterized in that it comprises a diamond particles that can improve the conditioning effect in the center and the edge portion of the polishing pad by varying the density to be attached according to the portion of the plate. 2. The polishing pad conditioner of claim 1, wherein a different density of adhesion depending on a portion of the flat plate is lower than a density at both ends of the polishing pad conditioner. 3. The polishing pad conditioner of claim 2, wherein the center portion is formed to have a density lower than both ends at a difference of 1 to 80%. The polishing pad conditioner of claim 1, wherein the polishing pad conditioner has a rectangular shape. The polishing pad conditioner of claim 4, wherein the rectangular shape has a short side length of 1 to 99 mm. The polishing pad conditioner of claim 1, wherein the diamond particles have a size of 1 to 999 µm. A flat plate composed of an alloy of nickel and steel, the length of which is in the range of ± 1 inch compared to the radius of the polishing pad, the width of both ends is wide, and the width of the center is narrow; And Polishing pad condition of the CMP device, characterized in that it comprises diamond particles that can improve the conditioning effect at the center and the edge of the polishing pad by using a diamond particle attached to one side of the flat plate at a certain density you. 8. The polishing pad conditioner of claim 7, wherein the width of the edge portion is wide and the width of the narrow portion of the center portion is varied between 1% and 80%. On top of the rotating polishing pad, the wafer is brought into close contact with the polishing pad, and the polishing pad conditioner of the CMP apparatus includes conditioning the polishing pad while the polishing pad conditioner reciprocates from the top to the edge of the polishing pad. In the ning method, The polishing pad conditioner uses a conditioner having a length in a range of ± 1 inch of the polishing pad radius, The polishing pad conditioner is a polishing pad condition characterized in that to improve the conditioning (conditioning) characteristics at the center and the edge of the polishing pad by varying the density of diamond particles for each part of the conditioner in close contact with the polishing pad in a fixed state Ning method. The method of claim 7, wherein the density of the diamond particles for each part of the conditioner in a fixed state in close contact with the polishing pad is characterized in that the density of the diamond particles formed in the center portion of the polishing pad conditioner to form lower than the density of both ends Polishing pad conditioning method of CMP equipment. [8] The polishing pad of claim 7, wherein the density of the diamond particles formed at the center of the polishing pad conditioner is lower than the density at both ends thereof so as to be formed with a difference in the range of 1 to 80%. Conditioning method.