Pad conditioner having reduced friction and method of manufacturing the same

10478941 ยท 2019-11-19

Assignee

Inventors

Cpc classification

International classification

Abstract

This invention relates to a conditioner for a chemical mechanical planarization pad, which is necessary for global planarization of a wafer in order to increase the degree of integration of a semiconductor device, and more particularly to a pad conditioner having a structure able to reduce friction with a pad so as to solve the problems caused by a lot of friction being generated upon conditioning, and to a method of manufacturing the same.

Claims

1. A pad conditioner having reduced friction, comprising: a substrate having a plurality of protrusions having different heights which are formed upwards and separated from each other by a same distance on part or all of one surface of the substrate, each of tops of the protrusions forming a plane parallel to the surface of the substrate; and a diamond layer disposed on the plurality of protrusions or on the entire surface having the protrusions, wherein a diamond crystalline structure of the diamond layer has a (1,0,0) growth plane, wherein the diamond layer is deposited using Chemical Vapor Deposition (CVD) under conditions including a filament temperature of 19002000 C. and a substrate temperature of 10001100 C., and wherein the plurality of protrusions comprise a first height group comprising a plurality of first protrusions having a first height, a second height group comprising a plurality of second protrusions having a second height, and a third height group comprising a plurality of third protrusions having a third height, in which the second height is lower than the first height, the third height is lower than the second height, and a difference between the first height and the second height is 1070 m, wherein each of the second protrusions of the second height group and each of the third protrusions of the third height group are formed such that only one of the second protrusions and only one of the third protrusions are disposed between a pair of first protrusions of the first height group in any direction.

2. The pad conditioner of claim 1, wherein the plurality of protrusions are formed separated by a distance of 0.125 mm.

3. The pad conditioner of claim 1, wherein the difference between the first height and the second height is 30 m and the difference between the second height and the third height is 30 m.

4. A method of manufacturing the pad conditioner having reduced friction, the pad conditioner comprising: a substrate having a plurality of protrusions having different heights which are formed upwards and separated from each other by a same distance on part or all of one surface of the substrate, each of tops of the protrusions forming a plane parallel to the surface of the substrate; and a diamond layer disposed on the plurality of protrusions or on the entire surface having the protrusions, wherein a diamond crystalline structure of the diamond layer has a (1,0,0) growth plane, wherein the diamond layer is deposited using Chemical Vapor Deposition (CVD) under conditions including a filament temperature of 19002000 C. and a substrate temperature of 10001100 C., and wherein the plurality of protrusions comprise a first height group comprising a plurality of first protrusions having a first height, a second height group comprising a plurality of second protrusions having a second height, and a third height group comprising a plurality of third protrusions having a third height, in which the second height is lower than the first height, the third height is lower than the second height, and a difference between the first height and the second height is 1070 m, wherein each of the second protrusions of the second height group and each of the third protrusions of the third height group are formed such that only one of the second protrusions and only one of the third protrusions are disposed between a pair of first protrusions of the first height group in any direction, the method comprising: preparing a substrate; forming a plurality of protrusions having a uniform height and separated from each other by a predetermined distance on a surface of the substrate, each of tops of the protrusions forming a plane parallel to the surface of the substrate; polishing the plurality of protrusions having the uniform height in a predetermined pattern so that the plurality of protrusions have different heights; and coating the surface of the substrate having the plurality of protrusions having different heights with a diamond layer, wherein the forming the plurality of protrusions is performed using a first step of etching and a second step comprising any one among an end mill, a milling cutter, a drill and a tap; the polishing the plurality of protrusions is performed using any one among an end mill, a milling cutter, a drill and a tap; and the coating is performed using CVD, wherein the diamond layer comprises a microcrystalline diamond coating layer having a thickness of 7090% of a total thickness and a nanocrystalline diamond coating layer having a thickness of 1030% which is a remainder of the total thickness formed on an upper surface of the microcrystalline diamond coating layer, and wherein the second step further comprises, when part of the height of the protrusions is formed, forming the remaining height of the protrusions using any one among a cutting wheel, an end mill, a milling cutter, a drill and a tap.

5. The method of claim 4, wherein subjecting at least one surface of the substrate to precise grinding and lapping is performed, before forming the protrusions.

6. The method of claim 4, wherein the difference between the first height and the second height is 30 m and the difference between the second height and the third height is 30 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

(2) FIG. 1 is an enlarged cross-sectional view showing a structure near the surface of the cutter of a conventional electroplated diamond conditioner;

(3) FIG. 2 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 1 of Example 1 according to the present invention;

(4) FIG. 3 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 1 of FIG. 2;

(5) FIG. 4 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 2 of Example 2 according to the present invention;

(6) FIG. 5 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 2 of FIG. 4;

(7) FIG. 6 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 3 of Example 3 according to the present invention;

(8) FIG. 7 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 3 of FIG. 6;

(9) FIG. 8 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 4 of Example 4 according to the present invention;

(10) FIG. 9 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 4 of FIG. 8;

(11) FIG. 10 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 5 of Example 5 according to the present invention;

(12) FIG. 11 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 5 of FIG. 10;

(13) FIG. 12 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 6 of Example 6 according to the present invention;

(14) FIG. 13 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 6 of FIG. 12;

(15) FIG. 14 is an enlarged cross-sectional view showing the structure of the cutting tip of the cutter of a pad conditioner 7 of Example 7 according to the present invention;

(16) FIG. 15 is an enlarged perspective view showing the surface structure of the cutting tip of the pad conditioner 7 of FIG. 14;

(17) FIGS. 16A to 16D are schematic views showing a process of manufacturing the pad conditioner according to the present invention; and

(18) FIG. 17 is a photograph showing the (1,0,0) growth plane of a diamond layer formed on the cutting tip of the pad conditioner according to the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

(19) Hereinafter, embodiments of the present invention will be described in detail while referring to the accompanying drawings, but the present invention is not limited thereto and may be embodied in other forms. Throughout the description, the same reference numerals are used to refer to the same or similar elements.

(20) Furthermore, the terms used in the present invention include as much as possible general terms which are currently widely used, but, in specific cases, may include optional terms chosen by the applicant, the meanings of which should be interpreted in consideration of the meanings described or used in the present specification instead of by simply using the names of such terms.

(21) The first technical feature of the present invention is that the structure of a cutting tip that forms a cutting surface of a CVD pad conditioner is changed, whereby friction upon conditioning is reduced and simultaneously slurry particles supplied onto a polishing pad may uniformly develop thus decreasing scratching due to the flocculation of the slurry.

(22) Based on the fact that pressure varies depending on the depth to which the cutting tip of the pad conditioner is inserted into a polishing pad which is a conditioning target and made of an elastically deforming material such as porous resin, rubber, polyurethane rubber, etc., the pad conditioner according to the present invention is configured such that protrusion groups having two or more different uniform heights (in lieu of having only one uniform height) are disposed in a predetermined pattern, thereby reducing friction, unlike a conventional CVD pad conditioner in which the entire cutting tip of a cutter has a uniform height. Further, the distances between the protrusions can be narrowed, thereby uniformly developing slurry particles.

(23) In order to embody the above technical features, the pad conditioner according to the present invention includes a substrate having a plurality of protrusions having different heights which are formed upwards and separated from each other by the same or different distances on part or all of one surface of the substrate, the tops of the protrusions forming a plane parallel to the surface of the substrate; and a diamond layer applied on the plurality of protrusions or on the entire surface having the protrusions. As such, the difference between the minimum height and the maximum height of the protrusion of the plurality of protrusions preferably falls in the range of 1070 m.

(24) In the case where the plurality of protrusions are separated from each other by the same distance, the plurality of protrusions include two protrusion groups comprising first protrusions having a first height and second protrusions having a second height or three protrusion groups comprising first protrusions having a first height to third protrusions having a third height, in which such protrusion groups are disposed in a predetermined pattern.

(25) In addition, in the case where the plurality of protrusions are separated from each other by different distances, the plurality of protrusions include a high height group comprising a plurality of high protrusions having a maximum first height which are formed separated by a predetermined distance, and a low height group comprising low protrusions having a height lower than the first height which are formed in a predetermined pattern in all or parts of the separation spaces between the high protrusions of the high height group, in which six or fewer low protrusions having the same or different heights per separation space are formed separated from each other, or the high height group and the low height group provide a plurality of unit groups each comprising two or more protrusions that are separated from each other, in which the plurality of unit groups may be formed such that a high height unit group and a low height unit group are alternately disposed. As such, each of the plurality of low height unit groups may have low protrusions having the same height.

(26) Among the plurality of protrusions which form the cutting tip of the cutter of the pad conditioner according to the present invention, protrusions having the same height have the same width, but protrusions having different heights may have the same or different widths.

(27) Also, in the case where the plurality of protrusions are separated from each other by the same distance, such a distance is preferably 0.12.5 mm. On the other hand, in the case where the plurality of protrusions are separated from each other by different distances, the separation distances between the high protrusions of the high height group having at least the maximum height are preferably the same as each other, in particular, 0.55.0 mm.

(28) The predetermined pattern of the plurality of protrusions is specified in the examples which will be described later and in the appended drawings.

(29) Also, the pad conditioner according to the present invention may have a variety of structures having various shapes depending on the shape of a substrate having the cutter and/or the body to which the substrate is attached, and the variety of structures of the substrate and/or the body are illustrated below.

(30) In the present invention, the shape of the substrate is not limited so long as there is a predetermined plane on which the plurality of protrusions may be formed. For example, the substrate may have the various shapes of the cutters of known pad conditioners, including not only a polygonal or circular flat panel, but also a cup-shaped structure the surface height of the middle of one surface of which is lower than the surface height of the outer periphery thereof so that a cross-section thereof is cup-shaped (not shown in the Figures), an angled doughnut-shaped structure, or a segment structure in which a plurality of valleys that extend in a radial direction from the center is formed on the surface of the periphery of the angled doughnut-shaped structure.

(31) However, in a typical pad conditioner including a cutter and a body, the body mainly plays a role in securely bonding the cutter thereto so that the cutter is connected to the motor rotating shaft of a conditioning device, and thus the body is not regarded as an essential element. Hence, the body of the pad conditioner according to the present invention may have various shapes, such as a cup shape, an angled doughnut shape or other shapes, so long as it is configured such that the cutter is bonded thereto so that the cutting tip of the cutter is exposed from the upper surface of a main body. Furthermore, if the pad conditioner according to the present invention is structurally changed so that the substrate thereof is directly bound to the motor rotating shaft, the body may be excluded.

(32) The substrate on which the cutter is formed is preferably made of a known ceramic or hard metal. In particular, ceramic is preferably composed mainly of silicon carbide, silicon nitride or alumina. When the substrate is prepared using such a material, wear resistance and corrosion resistance may be imparted to the cutting tip, and the cutting ability cannot deteriorate after extended use.

(33) In addition, the second technical feature of the present invention is that friction upon conditioning is further reduced because of the crystalline structure of the diamond layer formed on the surface of the cutting tip that forms the cutting surface of the CVD pad conditioner.

(34) In order to reduce friction upon conditioning as much as possible, the (1,0,0) plane of the diamond layer deposited using CVD is grown, and at least the surface coating is performed using nanocrystalline diamond so that the surface in contact with the polishing pad becomes smooth, in relation to the grain size of diamond used upon coating, thereby further reducing the friction upon conditioning.

(35) In order to embody the above technical features, the diamond layer of the pad conditioner according to the present invention is formed using CVD under conditions including a filament temperature of 19002000 C. and a substrate temperature of 10001100 C. As such, the diamond layer comprises a microcrystalline diamond coating layer having a grain size of 12 m and a nanocrystalline diamond coating layer having a grain size of 0.1 m (=100 nm) formed thereon, or is composed exclusively of a nanocrystalline diamond coating layer.

(36) However, because the coating rate of nanocrystalline diamond is slower than the coating rate of microcrystalline diamond, the diamond layer preferably comprises a microcrystalline diamond coating layer having a thickness of 7090% of the total thickness and a nanocrystalline diamond coating layer having a thickness of 1030% which is the remainder of the total thickness formed on the upper surface of the microcrystalline diamond coating layer.

(37) The diamond layer is deposited so that the thickness is actually uniform over the plurality of protrusions formed on the substrate or over the entire surface having the protrusions formed thereon. In particular, the layer thickness is set to fall in the range that imparts wear resistance to the cutting tip and neither breaks the coating layer nor causes cracks.

(38) In addition, the third feature of the present invention is that the plurality of protrusions are formed on the substrate using a method that decreases chipping, thus increasing dimensional reproducibility and productivity.

(39) Specifically, in the method of manufacturing the pad conditioner according to the present invention, portions of or all of the protrusions are formed on the surface of the substrate using etching, thereby enabling the formation of the upper surface of cutting tip units, namely, protrusions, without chipping.

(40) As such, in the case where portions of the protrusions are formed using etching, it is preferred that the protrusions preferably have a height of 150% of the total height (h), and it is more preferred that the surface of the substrate on which the protrusions are formed be subjected to precise grinding and lapping before the protrusions are formed on the surface of the substrate.

Example 1

(41) FIGS. 2 and 3 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 1 according to the present invention.

(42) With reference to FIGS. 2 and 3, the cutter of the pad condition 1 is configured such that the cutter 100 includes a substrate 110, a cutting tip 120 comprising a plurality of protrusions formed upwards and separated from each other by the same distance on all of one surface of the substrate, and a diamond layer 130 formed on the entire surface of the substrate having the cutting tip formed thereon. In some cases, the cutting tip 120 may be formed only on part of the surface of the substrate 110, and a body may be bonded to the other surface of the substrate 110, and the diamond layer may be formed only on the cutting tip 120.

(43) In the present invention, the cutting tip 120 refers to a group comprising a plurality of protrusions that respectively correspond to cutting tip units.

(44) As shown in the drawings, the cutting tip 120 comprises a first height group 121 comprising a plurality of first protrusions 121a having a first height and a second height group 122 comprising a plurality of second protrusions 122a having a second height. In particular, the cutting tip 120 of the pad conditioner 1 has a structure in which each of the second protrusions 122 of the second height group 122 is formed such that the second protrusion 122 is disposed between a pair of first protrusions 121a of the first height group 121 in any direction, and thus the cutting tip units are entirely arranged separated by the same distance in the repeating sequence of first height-second height-first height-second height. As such, the separation distance is 1.0 mm, and the difference between the first height and the second height is 50 m.

(45) In the drawings, the protrusions which are the cutting tip units are shown in the form of a square pillar, but the shape thereof is not limited so long as the tops thereof form a plane parallel to the surface of the substrate 110 and the lower surface thereof forms the surface of the substrate 110.

(46) The plane parallel to the surface of the substrate 110 refers not to points but to a surface and the area thereof is not limited. All of the tops of the protrusions may define a plane parallel to the surface of the substrate 110, or only parts of the tops thereof may define a plane parallel to the surface of the substrate 110. The shape of the tops of the protrusions may be variously changed, as needed. The protrusions are preferably provided in the form of any one among truncated polypyramids, truncated cones, polyprisms, and cylinders.

(47) As shown in the drawings, the diamond layer 130 is formed on the entire surface of the cutter 100, or may be formed only on the cutting tip 120. The technique for depositing the diamond layer 130 using CVD is known and a detailed description thereof is omitted.

(48) As such, the pad conditioner 1 may have any known shape and thus the entire shape of the pad conditioner is not shown.

Example 2

(49) FIGS. 4 and 5 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 2 according to the present invention.

(50) With reference to FIGS. 4 and 5, the cutter of the pad conditioner 2 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(51) As shown in the drawings, the cutting tip 120 of the pad conditioner 2 includes a first height group 121 comprising a plurality of first protrusions 121a having a first height and a second height group 122 comprising a plurality of second protrusions 122a having a second height, which are the same as in the pad conditioner 1 of Example 1. Furthermore, this cutting tip has a structure in which each of the second protrusions 122a of the second height group 122 is formed such that the second protrusion 122a is disposed between two pairs of first protrusions 121a of the first height group 121 in any direction, and thus the cutting tip units are entirely arranged separated by the same distance in the repeating sequence of first height-first height-second height-first height-first height-second height. As such, the separation distance is 1.0 mm, and the difference between the first height and the second height is 50 m.

Example 3

(52) FIGS. 6 and 7 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 3 according to the present invention.

(53) With reference to FIGS. 6 and 7, the cutter of the pad conditioner 3 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(54) As shown in the drawings, the cutting tip 120 of the pad conditioner 3 includes a first height group 121 comprising a plurality of first protrusions 121a having a first height and a second height group 122 comprising a plurality of second protrusions 122a having a second height, which are the same as in the pad conditioner 1 of Example 1. Furthermore, this cutting tip has a structure in which each of the first protrusions 121a of the first height group 121 is formed such that the first protrusion 121a is disposed between two pairs of second protrusions 122a of the second height group 122 in any direction, and thus the cutting tip units are entirely arranged separated by the same distance in the repeating sequence of second height-second height-first height-second height-second height-first height. As such, the separation distance is 1.0 mm, and the difference between the first height and the second height is 50 m.

Example 4

(55) FIGS. 8 and 9 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 4 according to the present invention.

(56) With reference to FIGS. 8 and 9, the cutter of the pad conditioner 4 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(57) As shown in the drawings, the cutting tip 120 of the pad conditioner 4 includes a first height group 121 comprising a plurality of first protrusions 121a having a first height, a second height group 122 comprising a plurality of second protrusions 122a having a second height, and a third height group 123 comprising a plurality of third protrusions 123a having a third height, and is thus different from the pad conditioners 13 having two height groups of Examples 13. However, these cutting tip units are formed separated from each other by the same distance, as in Examples 13. Thus, the cutting tip 120 of the pad conditioner 4 has a structure in which each of the second protrusions 122a of the second height group 122 and each of the third protrusions 123a of the third height group 123 are formed such that the second protrusion 122a and the third protrusion 123a are disposed between a pair of first protrusions 121a of the first height group 121 in any direction, and thus the cutting tip units are entirely arranged separated by the same distance in the repeating sequence of first height-second height-third height-first height-second height-third height. Although not shown, the array of cutting tip units in the repeating sequence of first height-third height-second height-first height-third height-second height is possible. As such, the separation distance is 0.7 mm, and the difference between the first height and the second height is 30 m, and the difference between the second height and the third height is 30 m.

Example 5

(58) FIGS. 10 and 11 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 5 according to the present invention.

(59) With reference to FIGS. 10 and 11, the cutter of the pad conditioner 5 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(60) As shown in the drawings, the cutting tip 120 of the pad conditioner 5 has an array of protrusions separated by different distances, unlike the pad conditioners 13 of Examples 13 having the protrusions separated by the same distance.

(61) Specifically, a plurality of high protrusions 124a of a high height group 124 having a maximum first height are separated from each other by the same distance, whereas a plurality of low protrusions 125a of a low height group 125 having a height lower than the first height may be formed so that six or fewer low protrusions having the same or different heights per separation space between the high protrusions 124a of the high height group 124 are formed separated from each other by different distances. These low protrusions may also be formed on all of the separation spaces between the high protrusions 124a, or may be formed only on parts of the separation spaces as shown in the drawings.

(62) In particular, the cutting tip 120 of the pad conditioner 5 has a structure in which each pair of the low protrusions 125a of the low height group 125 having the height (which is referred to as a second height) lower than the first height are formed such that the two low protrusions 125a are disposed in parts of the separation spaces between the high protrusions 124a of the high height group 124 which are separated from each other by the same distance, and thus the cutting tip units are entirely arranged separated by different distances in the repeating sequence of first height-first height-second height-second height-first height. As such, the separation distance between the high protrusions 124a is 2 mm, and the difference between the first height and the second height is 50 m.

Example 6

(63) FIGS. 12 and 13 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 6 according to the present invention.

(64) With reference to FIGS. 12 and 13, the cutter of the pad conditioner 6 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(65) As shown in the drawings, the cutting tip 120 of the pad conditioner 6 has three height groups of protrusions unlike the pad conditioners 13 of Examples 13 having only two height groups and protrusions separated by the same distance, and it has an array of protrusions separated by different distances as in the pad conditioner 5.

(66) Specifically, the cutting tip 120 of the pad conditioner 6 has a structure in which each of low protrusions 125b having a second height lower than a first height and each pair of low protrusions 125a having a third height lower than the second height of a low height group 125 are formed such that the low protrusion 125b and the two low protrusions 125a are disposed in parts of the separation spaces between high protrusions 124a of a high height group 124 which are separated from each other by the same distance so as to form a protruding contour in which the center is high and both sides are low, and thus the cutting tip units are entirely arranged separated by different distances in the repeating sequence of first height-third height-second height-third height-first height. As such, the separation distance between the high protrusions 124a is 2.0 mm, and the difference between the first height and the second height and the difference between the second height and the third height are each 30 m.

(67) Although not shown, even when five low protrusions are provided in the separation space between the high protrusions 124a, they are disposed to form a protruding contour in which the center is high and both sides are low as in the pad conditioner 6, which is considered to be preferable in terms of the generation of friction upon conditioning.

Example 7

(68) FIGS. 14 and 15 are respectively a cross-sectional view and a perspective view showing the enlarged structure of part of the cutting tip of the cutter of a pad conditioner 7 according to the present invention.

(69) With reference to FIGS. 14 and 15, the cutter of the pad conditioner 7 has the same structure as the pad conditioner 1 of Example 1, with the exception of the array of the cutting tip units of the cutting tip 120, and only the array of the cutting tip units of the cutting tip 120 is described below.

(70) As shown in the drawings, the cutting tip 120 of the pad conditioner 7 includes a high height group 124 comprising a plurality of high protrusions 124a and a low height group 125 comprising a plurality of low protrusions 125b having the same height lower than the height of the high protrusions 124a, in which the high height group 124 and the low height group 125 respectively provide a plurality of unit groups 124c, 125c each comprising twelve protrusions that are separated from each other. In particular, two high height unit groups 124c and two low height unit groups 125c are alternately disposed. As such, the width and the separation distance between the protrusions of the high height unit group 124c and the low height unit group 125c, and the separation distance between the unit groups are shown to be the same. In some cases, however, the width and the separation distance may become different. Hence, the cutting tip units are entirely arranged separated by different distances in the repeating sequence of first height group-first height group-second height group-second height group. As such, the separation distance between the high protrusions 124a is 1.0 mm, and the difference between the first height group and the second height group is 30 m.

Example 8

(71) Manufacturing of Pad Conditioner 1 of Example 1

(72) With reference to FIGS. 16A to 16D, the method of manufacturing the pad conditioner 1 of Example 1 is specified.

(73) As shown in FIG. 16A, portions of the surface of a substrate 110 on which protrusions will be formed are subjected to photolithography, and thus a photo mask 110a is formed on such a pattern.

(74) Next, as shown in FIG. 16B, the upper portions of the pattern are formed separated by a predetermined distance using etching, so that the upper portions 121a, 122a of protrusions are provided.

(75) Examples of the gas used for etching include CF.sub.4, CHF.sub.3, SF.sub.6, O.sub.2, N.sub.2, Ar, etc. The etching usable in the present invention may be either wet etching or dry etching, and dry etching is preferable considering the etching rate.

(76) Next, as shown in FIG. 16C, the remaining portions of the protrusions are processed thus forming a plurality of protrusions 121a having a uniform height.

(77) For example, in the case where the total height (h) of the protrusions is 100 m, portions about 150 m high are formed using etching, and the remaining portions 9950 m high are formed using processing.

(78) As such, processing after etching may be performed using grinding and/or cutting (hereinafter, simply referred to as cutting), and a cutting tool preferably used for cutting includes a cutting wheel, an end mill, a milling cutter, a drill, and a tap.

(79) Subsequently, the plurality of protrusions 121a having a uniform height are polished in a predetermined pattern, so that a plurality of protrusions 121a, 122a having different heights are formed. Specifically, in order to form the pattern of the pad conditioner 1 in which a low protrusion 122a is formed between two high protrusions 121a, portions of the plurality of protrusions 121a having a uniform height are cut using the above cutting tool so that their height is processed, thereby forming low protrusions 122a.

(80) Subsequently, the substrate having the plurality of protrusions having different heights is pretreated, and is then coated with a diamond layer. The process of coating the surface of the substrate with the diamond layer includes but is not limited to CVD. As such, the CVD process conditions are preferably controlled so that the filament temperature is set to 19002000 C. and the substrate temperature is set to 10001100 C. in order to grow a (1,0,0) plane of diamond as shown in FIG. 17.

(81) Meanwhile, it is preferred that the surface of the substrate be subjected to precise grinding and lapping before the plurality of protrusions are formed on the substrate. Specifically, when precise grinding and lapping are performed on the surface of the substrate, the surface of the substrate is imparted with an actually uniform flatness, and both surfaces of the substrate are actually maintained parallel to each other.

(82) As mentioned above, the cutting tip of the cutter of the pad conditioner according to the present invention includes a plurality of protrusions having different heights. Thus, when the pad conditioner according to the present invention is manufactured, etching is partially or exclusively used as above instead of using only a diamond wheel device, or a CNC which is not specified herein is partially or exclusively used, thereby obtaining a desired pattern.

Comparative Example 1

(83) A diamond electroplated disk was manufactured by sprinkling diamond particles on a main body made of stainless steel and electroplating the diamond particles using a conventional known method.

Comparative Example 2

(84) Using a method disclosed in Korean Patent No. 100387954, a CVD disk was manufactured by depositing a diamond layer using CVD on a cutter of a pad conditioner comprising truncated pyramids having almost a uniform height.

Comparative Example 3

(85) Under CVD process conditions including a filament temperature of 19002000 C. and a substrate temperature of 10001100 C., the (1,0,0) plane of diamond was grown upon deposition of the diamond layer of Comparative Example 2, thus manufacturing a CVD disk having the (1,0,0) growth plane. The photograph of the growth plane is shown in FIG. 17.

Test Example 1

(86) In order to measure the torque of a pad conditioner, a test for measuring the load applied to the motor of a disk arm was performed. The average torque applied to the disk rotating motor was uniform depending on the type of disk (i.e., pad conditioner) and changes in pressure, and thus the results from the type of disk and the pressure could not be checked by the average torque. However, because the torque amplitude varies depending on the type of disk and the changes in pressure, the results from the type of disk and the pressure could be checked. Specifically, as the load becomes larger, the torque range is increased. In contrast, as the load is smaller, the torque range is decreased. Thereby, the degree of load of the disk can be detected with the torque range.

Test Example 2

(87) The torque range of each of the electroplated disk of Comparative Example 1, the CVD disk of Comparative Example 2, the disk having the (1,0,0) growth plane of Comparative Example 3, and the pad conditioner 1 of Example 1 was measured. The results are shown in Table 1 below.

(88) TABLE-US-00001 TABLE 1 C. Ex. 1 C. Ex. 2 Ex. 1 C. Ex. 3 Max 30.9 33.4 30.4 31.8 Min 18.7 16.8 17.5 18.6 Range 12.2 16.6 12.9 13.2 Average 24.4 24.4 22.5 23.5

(89) As is apparent from Table 1, the pad conditioner 1 of Example 1 according to the present invention has the torque range smaller than those of the conventionally known pad conditioners, from which friction can be seen to be significantly reduced. Also, when the (1,0,0) plane of the diamond layer is grown, the torque range is small even under conditions in which the cutting tip includes protrusions that are almost uniform in height, thus effectively reducing the friction. Hence, when the cutting tip includes protrusions having different heights and the (1,0,0) plane of the diamond layer is grown, the degree to which the friction is reduced is expected to be much higher.

Test Example 3

(90) In order to evaluate the degree of friction reduction in relation to a predetermined pattern of a cutting tip, the torque range of each of the pad conditioner 1 of Example 1, the pad conditioner 2 of Example 2, and the pad conditioner 3 of Example 3 was measured. The results are shown in Table 2 below.

(91) TABLE-US-00002 TABLE 2 C. Ex. 2 Ex. 1 Ex. 2 Ex. 3 Max 33.4 31.4 31.3 31.8 Min 16.8 17.3 16.3 16.4 Range 16.6 14.1 15 15.4 Average 24.4 23.8 23.7 25.4

(92) As is apparent from Table 2, even when the pattern of the cutting tip is changed, the degree of friction reduction becomes remarkably superior compared to Comparative Example 2 having uniform protrusions. Among the pad conditioners according to the present invention, the pattern of the pad conditioner 1 of Example 1 can be more effective in friction reduction, compared to the other patterns.

Test Example 4

(93) In order to evaluate the degree of friction reduction in relation to a difference between the first height and the second height when using a cutting tip comprising two different height groups of a plurality of protrusions, the pattern of Example 1 is provided but the height of the low cutting tip units is changed, thus manufacturing four pad conditioners in which the difference between the first height and the second height is 10 m, 30 m, 50 m, and 70 m. The torque ranges of such pad conditioners in relation to the height were measured. The results are shown in Table 3 below.

(94) As shown in Table 3 below, as the height difference increases, the torque range tends to decrease. However, taking into consideration the conditioning effect, when the height difference is 50 m, the optimal effect can be obtained.

(95) TABLE-US-00003 TABLE 3 Height Height Height Height Difference Difference Difference Difference 10 m 30 m 50 m 70 m Max 30.4 31.2 31.4 32.4 Min 17.5 11.5 17.3 16.6 Range 12.9 13.7 14.1 15.8 Average 22.5 23.1 23.8 23.3

(96) As described hereinbefore, the present invention provides a pad conditioner having reduced friction and a method of manufacturing the same. According to the present invention, the pad conditioner is configured such that friction upon conditioning can be reduced, and thus the lifespan of a polishing pad can be prolonged.

(97) Also in the pad conditioner according to the present invention, slurry particles supplied onto the polishing pad can be uniformly developed, and thus scratching due to the flocculation of the slurry can be decreased.

(98) Also the pad conditioner according to the present invention is configured such that surface uniformity of the polishing pad can be ensured upon conditioning, and thus the quality of a workpiece which is processed using the polishing pad can be improved.

(99) Also the method of manufacturing the pad conditioner according to the present invention enables the dimensional reproducibility of the pad conditioner to increase thus decreasing defective rates, and also the manufacturing rate to increase, resulting in high productivity.

(100) Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that a variety of different modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, such modifications, additions and substitutions should also be understood as falling within the scope of the present invention.