Chemical Mechanical Polishing Pad Dresser and Manufacturing Method Thereof

Abstract

The present invention provides a chemical mechanical polishing pad dresser, which comprises: a substrate having an upper surface; and an abrasive layer covering the upper surface of the substrate, and the abrasive layer including a bonding layer and a plurality of abrasive particles embedded in the bonding layer. Each of the abrasive particles has a tip height, which is a distance between the highest point of each abrasive particle and a surface of the bonding layer; wherein the chemical mechanical polishing pad dresser has an imaginary surface, which is a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles, and wherein the distance between the tip height of each of the abrasive particles and the imaginary surface is a value of the tip variation, which is less than 50 μm; besides, 80% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm. By controlling the distance between the tip heights of the plurality of abrasive particles and the imaginary surface, the present invention can effectively reduce the occurrence of killer diamond, thereby reducing the probability that the dresser will occur deep grooves on the polishing pad during polishing process, causing wafer scratches, and reducing the yield of the wafer.

Description

FIELD OF TECHNOLOGY

[0001] The present invention relates to a chemical mechanical polishing pad dresser, and in particular to a chemical mechanical polishing pad dresser having a leveling surface. However, the present invention is not limited to this.BACKGROUND

[0002] During polish or burnishing of a semiconductor wafer, in order to flatten the surface of the wafer, chemical mechanical polishing (CMP) is typically used to process the wafer. However, during the chemical mechanical polishing process, polishing debris will be produced, and the polishing slurry used will also accumulate in the holes of the polishing pad, which will not only wear away the polishing pad, but also reduce the polishing effect. Therefore, it is necessary to dress the polishing pad by using a polishing pad dresser to prolong the service life of the polishing pad.

[0003] A commonly used polishing pad dresser uses diamonds fixed to a metal disk to dress the polishing pad. However, with the increasing use of the polishing pad dresser, the diamonds on the surface will be worn, causing an uneven surface of the dresser, which will cause scratches and wear on the polishing pad when dressing the polishing pad.

[0004] In view of the increasing requirements for leveling wafer, the standards for polishing pad dressers have also increased. At present, there are many improved chemical mechanical polishing pad dressers. For example, in the prior art, Taiwan patent No. TWI487019B discloses a chemical mechanical polishing pad dresser with flattened tips and a related method thereof. The chemical mechanical polishing pad dresser includes: a substrate layer; and a single layer of super abrasive particles, which are a plurality of super abrasive particles embedded in the substrate layer. Each of the super abrasive particles protrudes from the substrate layer. The difference in protrusion distance between the highest protrusion tip and the second highest protrusion tip of the single layer of super abrasive particles is less than or equal to about 20 microns, and the difference in protrusion distance between the highest 1% protrusion tips of the single layer of super abrasive particles is about 80 microns or less. According to this invention, the protrusion distances of the highest protrusion tip and the second highest protrusion tip are controlled to obtain the super abrasive particles with substantially flattened tips, thereby preventing the protruding super abrasive particles from wearing away the surface of the polishing pad.

[0005] Taiwan patent No. TWI383860B1 discloses a combined dresser, which includes: a large substrate, having a bonding surface, a bottom surface, and a plurality of through holes or a plurality of accommodating grooves; and a plurality of polishing units, each having a plurality of abrasive particles respectively having a plurality of cutting ends. The plurality of through holes or the plurality of accommodating grooves respectively accommodate the plurality of polishing units, and the plurality of cutting ends respectively protrude from the bonding surface. The plurality of polishing units are bonded to the large substrate by a bonding agent. The height difference between the plurality of cutting ends of the plurality of abrasive particles and a plane is within 20 microns. According to the large-area combined dresser of this invention, the cutting ends of most of the abrasive particles can be easily made on the same height, and different abrasive particles can be used according to different needs. Moreover, the large-area dresser formed by combining a plurality of small polishing units is lower in cost.SUMMARY

[0006] As can be seen from the prior art, although there are many patents related to flattening the surface of the chemical mechanical polishing pad dresser, there is a big tip height difference between the abrasives of the chemical mechanical polishing pad dresser in these patents. For example, in Taiwan patent No. TWI487019B, the flatness of the dresser is measured by using only the highest protrusion tip and the second highest protrusion tip as the baseline. There is no big tip height difference between the highest protrusion tip and the second highest protrusion tip, but there is a big tip height difference between the highest protrusion tip and the lowest protrusion tip, so the most protruding tip is easily separated from the tips behind. Consequently, some protrusion tips will still cause abnormal deep grooves on the surface of the polishing pad, causing wafer scratches and producing defects.

[0007] In the combined dresser disclosed in Taiwan patent No. TWI383860B1, by controlling the tip heights of the abrasive particles, the height difference between the cutting ends of the plurality of abrasive particles and a plane is controlled within 20 microns. However, different abrasive particles will be worn away to different degrees during polishing, and using the tip heights of the abrasive particles as a limit will still lead to a big height difference between different abrasive particles, so that the abrasive particles cannot be distributed uniformly.

[0008] In view of the shortcomings in the prior art, the present invention is aimed at improving the difference in the tip height distribution of the surface of the chemical mechanical polishing pad dresser. By controlling this difference within a specific range, the tip heights of the surface of the dresser are distributed uniformly, which reduces the probability that the dresser will occur deep grooves on the polishing pad during polishing process, thereby reducing scratch defects of the wafer and further improving the yield.

[0009] Therefore, the primary objective of the present invention is to provide a chemical mechanical polishing pad dresser, comprising: a substrate having an upper surface; and an abrasive layer covering the upper surface of the substrate, the abrasive layer comprising a bonding layer and a plurality of abrasive particles embedded in the bonding layer, and each of the abrasive particles having a tip height, which is a distance between the highest point of each abrasive particle and a surface of the bonding layer; wherein the chemical mechanical polishing pad dresser has an imaginary surface, which is a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles, and wherein the distance between the tip height of each of the abrasive particles and the imaginary surface is a value of the tip variation, which is less than 50 μm; and 80% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

[0010] In one aspect of the present invention, the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

[0011] In one aspect of the present invention, the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 15 μm.

[0012] In one aspect of the present invention, 95% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

[0013] In one aspect of the present invention, 99% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

[0014] In one aspect of the present invention, the tip height of each of the abrasive particles is 20 μm to 300 μm.

[0015] In one aspect of the present invention, a standard deviation of the tip heights is less than 20 μm.

[0016] In one aspect of the present invention, the abrasive particles are arranged on the substrate in an array or a honeycomb.

[0017] In one aspect of the present invention, the material of the substrate is selected from a group consisting of metals, ceramics and polymer resins.

[0018] In one aspect of the present invention, the material of the bonding layer is a brazing material, an electroplating material, a ceramic material, a metal material or a polymer material.

[0019] In one aspect of the present invention, the abrasive particles are selected from a group consisting of natural diamond, synthetic diamond, polycrystalline diamond, cubic boron nitride, aluminum oxide and silicon carbide.

[0020] Another aspect of the present invention is to provide a manufacturing method of a chemical mechanical polishing pad dresser with a leveling surface, comprising: (a) providing a substrate and an abrasive layer having a bonding layer and a plurality of abrasive particles, and the abrasive layer forming on an upper surface of the substrate; (b) heat-curing the bonding layer, and fixing the abrasive layer fixed on the upper surface of the substrate; (c) measuring a tip height of each of the abrasive particles, and obtaining a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles as an imaginary surface; and (d) adjusting the tip heights of the plurality of abrasive particles according to the imaginary surface such that the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 50 μm, thereby obtaining the chemical mechanical polishing pad dresser with a leveling surface.

[0021] In one aspect of the present invention, the abrasive particles are arranged on the substrate in an array or a honeycomb.

[0022] In one aspect of the present invention, the bonding layer is formed on the substrate by brazing, electroplating, ceramic sintering, metal curing or polymer curing.

[0023] By controlling the distance between each of the tip heights of the plurality of abrasive particles and the imaginary surface, the chemical mechanical polishing pad dresser of the present invention can effectively reduce the occurrence of killer diamonds so as to obtain the chemical mechanical polishing pad dresser having abrasive particles that are uniformly distributed and have similar tip heights, thereby reducing the probability that the dresser will occur deep grooves on the polishing pad during polishing process, causing wafer scratches, and reducing the yield of the wafer.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the present invention will be described only by way of example with reference to the accompanying drawings.

[0025] FIG. 1 shows a schematic view of a chemical mechanical polishing pad dresser according to an example of the present invention;

[0026] FIG. 2A to FIG. 2C show tip height distribution diagrams according to examples and comparative examples of the present invention;

[0027] FIG. 3 shows SEM results of surfaces of polishing pads dressed by CMP dressers according to an example and a comparative example of the present invention, where FIG. 3(A) shows an undressed polishing pad, FIG. 3(B) shows a polishing pad dressed by the CMP dresser of the example, and FIG. 3(C) shows a polishing pad dressed by the CMP dresser of the comparative example;

[0028] FIG. 4 shows a cutting rate distribution diagram of CMP dressers according to an example and a comparative example of the present invention; and

[0029] FIG. 5 shows a wafer defect rate diagram according to an example and a comparative example of the present invention.

[0030] It should be understood that aspects of the present invention are not limited to the configurations, means and characteristics shown in the accompanying drawings.DESCRIPTION OF THE EMBODIMENTS

[0031] According to the usual operation mode, various features and components in the drawings are not drawn to actual scale, but are drawn in such a manner as to best present the specific features and components related to the present invention. In addition, in different drawings, the same or similar component symbols are used to denote similar components and parts.

[0032] The following implementations should not be regarded as unduly limiting the present invention. Those of ordinary skill in the art to which the present invention belongs can modify and change the examples discussed herein without departing from the spirit or scope of the present invention, and these modifications and changes still fall within the scope of the present invention.

[0033] As used herein, unless otherwise specified in the context, the term “comprise”, “include”, “have” or “contain” is inclusive or open-ended, and does not exclude other unstated elements or method steps. The terms “a” and “the” may be interpreted as singular or plural. The term ‘one or more’ means ‘at least one’, and may therefore include a single feature or a mixture / combination. In addition, in this specification and the appended claims, unless otherwise specified, “formed on something” may be regarded as directly or indirectly contacting the surface of something by attachment or other forms, and the definition of the surface should be judged according to the meaning of the preceding / following paragraphs of the specification and the common knowledge of the art to which this specification belongs.

[0034] The “chemical mechanical polishing pad dresser”, “CMP dresser”, “polishing pad dresser”, “dresser”, and “conditioner” described herein may be used interchangeably, and refer to tools for polishing and burnishing the surface of the polishing pad to remove residues on the surface of the polishing pad, so as to maintain a certain roughness of the polishing pad.

[0035] The terms “abrasive particle”, “polishing grain” and “abrasive” described herein may be used interchangeably, and refer to an object with a tip for polishing and burnishing the surface of the polishing pad.

[0036] Referring to FIG. 1, one aspect of the present invention provides a chemical mechanical polishing pad dresser 100, including: a substrate 110 having an upper surface; and an abrasive layer 120, the abrasive layer 120 covering the upper surface of the substrate 110, and the abrasive layer 120 including a bonding layer 121 and a plurality of abrasive particles 122 embedded in the bonding layer 121. Each of the abrasive particles 122 has a tip 1221, and a tip height H with a surface of the chemical mechanical polishing pad dresser. As used herein, the so-called “tip” refers to the abrasive particle protruding from the bonding layer, which is the highest point of the abrasive particle and has a sharp point that can be used to polish an object. The so-called “tip height H” refers to the distance of the highest point of the abrasive particle relative to the surface of the chemical mechanical polishing pad dresser. In detail, the tip height H refers to the distance between the sharp point part of the abrasive particle protruding from the bonding layer and the surface of the bonding layer, which varies according to the size of the abrasive particle and the degree of coverage by the bonding layer. The term “protrusion” refers to the height of the tip of an object relative to a reference point, and the reference point includes the upper surface of the substrate, the surface of the bonding layer, the surface of the chemical mechanical polishing pad dresser, etc., but the present invention is not limited thereto.

[0037] The “substrate” referred to herein is selected from a group consisting of metals, ceramics and polymer resins, as long as it can carry the abrasive layer in practice. A preferred material may be a metal substrate or a metal alloy substrate. More specifically, the metal substrate includes, but not limited to, copper, iron, aluminum, titanium, tin, or the like. The metal alloy substrate includes, but not limited to, an iron alloy, a copper alloy, an aluminum alloy, a titanium alloy, a magnesium alloy or the like.

[0038] The “bonding layer 121” referred to herein is used to carry a layer of the plurality of abrasive particles 122 and is attached to the substrate 110. The abrasive particles 122 are mainly embedded and fixed in the bonding layer 121. Specifically, the material of the bonding layer 121 includes a brazing material, an electroplating material, a ceramic material, a metal material or a polymer material, but the present invention is not limited thereto. Further, the brazing material, the electroplating material or the metal material are selected from a group consisting of iron, cobalt, nickel, chromium, manganese, silicon and aluminum. The polymer material includes epoxy resins, polyester resins, polyacrylic resins or phenolic resins. In addition, the ceramic material includes various metal oxides, nitrides, carbides, borides, silicides or combinations thereof, such as silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, titanium carbide, titanium boride or boron carbide. The bonding layer 121 is formed on the substrate 110 in a manner which is not limited in the present invention, such as resin organic bonding, electroplating, brazing, electrodeposition, ceramic sintering, metal curing or polymer curing.

[0039] The “abrasive layer 120” referred to herein refers to an object that is formed on a substrate (or baseplate) and has a certain hardness so that the polishing pad can be dressed. The “abrasive particles 122” referred to herein are selected from a group consisting of natural diamond, synthetic diamond, polycrystalline diamond (PCD), cubic boron nitride (cBN), aluminum oxide and silicon carbide. The diamonds may be monocrystalline or polycrystalline. The shape of the abrasive particle 122 may be, but not limited to, a pyramid, a cone, an arc, a cylinder, a blade or a prism. The cone and the cylinder include, but not limited to, a cone, a cylinder, an elliptic cone and an elliptic cylinder. The pyramid and the prism include, but not limited to, a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid, a hexagonal pyramid, a heptagonal pyramid, an octagonal pyramid, a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, a heptagonal prism and an octagonal prism. According to an example of the present invention, the form of the abrasive particles 122 includes particles, grits, layers, flakes, fragments and the like, but the present invention is not limited thereto. In addition, the arrangement method of the abrasive particles 122 is not limited in the present invention, and the abrasive particles may be arranged in an array, concentric circles, a honeycomb or a pattern or randomly. In a preferred embodiment, the abrasive particles 122 are arranged on the substrate 110 in an array or a honeycomb.

[0040] After a period of use, the abrasive particles on the surface of the polishing pad dresser will be worn, and different abrasive particles are worn to different degrees, which causes nonuniform heights of the surface of the dresser and further increase the possibility of forming killer diamonds, thus affecting the polishing effect. The “killer diamonds” refer to the diamonds that penetrate into the polishing pad the deepest. Since the abrasive particles are worn during polishing, some abrasive particles on the same plane have larger tip heights, and some abrasive particles have smaller tip heights, thus resulting in great height differences. The killer diamonds are the abrasive particles with extremely large tip heights. Therefore, during the polishing of the dresser, the killer diamonds will penetrate deeper into the polishing pad than other abrasive particles with smaller tip heights, thereby generating deep grooves on the polishing pad and affecting the yield of the subsequent wafer process.

[0041] Therefore, in order to avoid the formation of killer diamonds, the present invention defines an imaginary surface, which is a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles. By controlling the distance between each of the tip heights of the plurality of abrasive particles and the imaginary surface, the abrasive particles are uniformly distributed on the surface of the dresser and have a small tip height difference, thereby improving the effective dressing ratio of the dresser and further increasing the wafer removal rate and the service life of the chemical mechanical polishing pad dresser.

[0042] Still referring to FIG. 1, according to an example of the present invention, the chemical mechanical polishing pad dresser 100 has an imaginary surface T. The imaginary surface T is a plane calculated on the basis of the average of each of the tip heights H of the plurality of abrasive particles 122, and the distance between the tip height H of each of the abrasive particles 122 and the imaginary surface T is a value of the tip variation. The value of the tip variation is less than 50 μm, for example, but not limited to, less than 50 μm, less than 48 μm, less than 45 μm, less than 41 μm, less than 40 μm, less than 39 μm, less than 35 μm, less than 33 μm, less than 32 μm, less than 30 μm, less than 29 μm, less than 25 μm, less than 23 μm, less than 20 μm, less than 18 μm, less than 16 μm, less than 15 μm, less than 12 μm, less than 10 μm, less than 9 μm, less than 8 μm, less than 7 μm, less than 6 μm, less than 5 μm, less than 4 μm, less than 3 μm, less than 2 μm, or less than 1 μm. In a preferred embodiment, the abrasive particles 122 have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 30 μm. In a more preferred embodiment, the value of the tip variation is less than 15 μm. When the value of the tip variation between the tip height H of the abrasive particle 122 and the imaginary surface T is within the above range, the tip height difference between the abrasive particles can be reduced, so that when the polishing pad dresser dresses the polishing pad, a polishing pad with fine scores can be generated, thereby increasing the wafer removal rate.

[0043] According to an example of the present invention, the tip height of each of the abrasive particles 122 is 20 μm to 300 μm, for example, but not limited to, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, or 300 μm. In the plurality of abrasive particles 122, a standard deviation of the tip heights is less than 20 μm, for example, but not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0044] According to an example of the present invention, 80% or more of the abrasive particles of the chemical mechanical polishing pad dresser of the present invention have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 30 μm, for example, but not limited to, less than 1 μm, less than 2 μm, less than 3 μm, less than 4 μm, less than 5 μm, less than 6 μm, less than 7 μm, less than 8 μm, less than 9 μm, less than 10 μm, less than 11 μm, less than 12 μm, less than 13 μm, less than 14 μm, less than 15 μm, less than 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, or 30 μm. More preferably, 95% or more of the abrasive particles have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 30 μm. Most preferably, 99% or more of the abrasive particles have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 30 μm. By controlling the tip height H difference between the abrasive particles on the surface of the dresser, all the abrasive particles have an average tip height H, so that the dresser has a concentrated cutting rate and good polishing performance.

[0045] The imaginary surface may be obtained by measuring differences in the tip height by various methods and averaging the differences in the tip height. The method includes direct measurement or indirect measurement. The direct measurement includes optical scanning, FRT scanning, etc. The optical scanning uses an optical scanner to scan the surface of the chemical mechanical polishing pad dresser to measure the tip heights of the plurality of abrasive particles. Specifically, the optical scanner locates the largest tip height by scanning the whole space of the polishing pad dresser, and then uses the largest tip height as a reference point to define the distance from the reference point to the tip of each abrasive particle on the whole surface of the polishing pad dresser, so as to calculate the tip height difference between the abrasive particles. The FRT scanning measures the tip heights of all the abrasive particles on the surface of the polishing pad dresser, and then defines a plane suitable for all tip heights by the least square method; or may define the largest tip height on the surface, and then decide the tip heights of the remaining abrasive particles based on the largest tip height.

[0046] The indirect measurement uses the tips of a plurality of, such as 1000 or 1500, highest abrasive particles to construct a defined plane, and then measures the relative tip height difference of the remaining abrasive particles based on the defined plane; or may arrange the abrasive particles on a deformed substrate, and indirectly infer the degree of deformation of the substrate based on the scratches formed by the abrasive particles on the deformed substrate so as to calculate the tip heights of the abrasive particles.

[0047] Another aspect of the present invention provides a manufacturing method of a chemical mechanical polishing pad dresser with an leveling surface, including: (a) providing a substrate and an abrasive layer having a bonding layer and a plurality of abrasive particles, and the abrasive layer forming on an upper surface of the substrate; (b) heat-curing the bonding layer, and the abrasive layer fixed on the upper surface of the substrate; (c) measuring a tip height H of each of the abrasive particles, and obtaining a plane calculated on the basis of the average of each of the tip heights H of the plurality of abrasive particles as an imaginary surface T; and (d) adjusting the tip heights H of the plurality of abrasive particles according to the imaginary surface T such that the abrasive particles have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 50 μm, thereby obtaining the chemical mechanical polishing pad dresser with a leveling surface.

[0048] In detail, the manufacturing method includes: First, a substrate is provided. The substrate is preferably circular, but the invention is not limited thereto. Then, a bonding layer formed on an upper surface of the substrate is provided. The bonding layer may be formed by various methods, such as resin organic bonding, electroplating, brazing, electrodeposition, ceramic sintering, metal curing or polymer curing, but the present invention is not limited thereto. Further, a plurality of abrasive particles embedded in the surface of the bonding layer are provided, and the bonding layer is heat-cured such that the plurality of abrasive particles are fixed on the upper surface of the substrate. The formation method of the abrasive particles is not limited in the present invention, and the abrasive particles may be arranged in an array, concentric circles or a honeycomb or randomly. In a preferred embodiment, the abrasive particles are arranged on the substrate in an array or a honeycomb.

[0049] After the fixation of the abrasive particles is completed, a tip height H of each of the abrasive particles is measured, and a plane calculated on the basis of the average of each of the tip heights H of the plurality of abrasive particles is obtained as an imaginary surface T. Finally, each of the tip heights H of the plurality of abrasive particles is adjusted according to the imaginary surface T such that the abrasive particles have a value of the tip variation between the tip height H of each of the abrasive particles and the imaginary surface T which is less than 50 μm, thereby obtaining the chemical mechanical polishing pad dresser with a leveling surface. The tip height H of each of the abrasive particles is 20 μm to 300 μm, and a standard deviation of the tip heights is less than 20.EXAMPLES

[0050] Hereinafter, the present invention will be further described with detailed description and examples. However, it should be understood that these examples are merely intended to help make the present invention easier to understand and are not intended to limit the scope of the present invention.1. Use of Different Height Baselines to Distinguish Killer Diamonds of Chemical Mechanical Polishing Pad Dresser

[0051] A chemical mechanical polishing pad dresser containing about 10,000 abrasive particles is taken. The abrasive particles have a particle size of 350 μm, and the tip height of the highest abrasive particle is 160 μm. A tip height distribution diagram shown as FIG. 2A is drawn based on each of the tip heights of the abrasive particles of the dresser. Point A indicates the abrasive particles with larger tip heights, which protrude from the surface of the bonding layer to a great extent (about 160 μm); and these abrasive particles are the killer diamonds described herein, and there are about 20 such abrasive particles. Point B indicates the abrasive particles with an average height, which are working abrasive particles (about 130 μm) that can perform polishing without damaging the polishing pad, and there are about seven to eight thousands such abrasive particles. Point C indicates the abrasive particles with smaller tip heights (about 0 μm to 10 μm), and there are about tens of such abrasive particles.Example: Use of Imaginary Surface as Baseline

[0052] Referring to FIG. 2B, a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles of the chemical mechanical polishing pad dresser is used as a baseline, i.e., the imaginary surface described herein is used as a baseline for measuring the tip height difference, so that the tip height distribution diagram shown in FIG. 2B can be obtained.Comparative Example: Use of Tip of Abrasive Particle as Baseline (No. TWI383860B1 in the Prior Art)

[0053] Referring to FIG. 2C, the chemical mechanical polishing pad dresser described above is used for testing. However, in the comparative example, the abrasive particle with the highest tip is used as the baseline to measure the tip height difference from the other abrasive particles so as to obtain the tip height distribution diagram shown in FIG. 2C.

[0054] The result shows that the distance between the imaginary surface calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles in the example and the surface of the bonding layer is 130 μm, and the imaginary surface can be used as the baseline to obtain a value of the tip variation of point A1 which is 30 μm, a value of the tip variation of point B1 which is 0 μm, and a value of the tip variation of point C1 which is-130 μm. Therefore, as can be seen from the data above, the dresser of the example can effectively distinguish the tip height difference between the killer diamonds and the working abrasive particles, so that the existence of the killer diamonds can be easily identified. In contrast, the comparative example uses the highest tip of the abrasive particles as the baseline (i.e., the height of point A2 is 0 μm) for measuring the heights of the abrasive particles, so the dresser of the comparative example can only distinguish the working abrasive particles and the abrasive particles with smaller tip heights (the height of point B2 is-30 μm, and the height of point C2 is-160 μm), and cannot effectively identify the existence of the killer diamonds (point A2)2. Performance and Efficacy of Chemical Mechanical Polishing Pad Dressers with Different Values of the Tip Variation

[0055] In this test, the effects of different values of the tip variation on the performance, cutting rate and wafer defect rate of the polishing pad are tested. This test uses the imaginary surface as the baseline to measure the tip heights and the distance between the tip height of each of the abrasive particles and the imaginary surface so as to prepare the examples and the comparative examples. The result is shown in Table 1 below.TABLE 1Chemical mechanical polishing pad dressers with different tip heightsExampleExampleExampleComparativeComparativeComparative123Example 1Example 2Example 3Tip height20150300100200500(μm)Value of the51325635275tip variationbetween tipheight andimaginarysurface (μm)2-1. Performance of Polishing Pad

[0056] After the polishing pad is dressed by the CMP dressers of the examples and the comparative examples, the result is shown in FIG. 3. FIG. 3(A) shows an undressed polishing pad, FIG. 3(B) shows a polishing pad dressed by the CMP dresser of the example, and FIG. 3(C) shows a polishing pad dressed by the CMP dresser of the comparative example. The result shows that when the value of the tip variation between the tip height of the CMP dresser and the imaginary surface is less than 50 μm, since the tip height differences between the abrasive particles are uniform, the polishing pad can be effectively processed, so that the dressed polishing pad has fewer holes blocked, and thus has better polishing performance for the wafer. In contrast, when the value of the tip variation between the tip height and the imaginary surface is greater than 50 μm, since there are big tip height differences, the abrasive particles process the polishing pad to different degrees, so that residues in the holes of the polishing pads cannot be effectively removed, and thus, the polishing pad has more holes blocked and thus has poor polishing performance.2-2. Cutting Rate Distribution

[0057] Referring to FIG. 4, as can be seen from the measurement result of the cutting rate distributions of the CMP dressers of the example and the comparative example, since the cutting rate distribution of the CMP dresser of the example is relatively concentrated, the abrasive particles have better cutting rates, so that a polishing pad with a certain roughness can be obtained during dressing. In contrast, the cutting rate distribution of the CMP dresser of the comparative example is relatively loose, so this CMP dresser has poor cutting rates, and the dressed polishing pad has a poor roughness.2-3. Wafer Defect Rate

[0058] Referring to FIG. 5, the polishing pads dressed by the CMP dressers of the example and the comparative example above are further used to polish wafers. In the example and the comparative example, 12 wafers are respectively used for testing, and the defects of these wafers are recorded. The result shows that the wafers polished by the polishing pad of the example have fewer scratches, thus having fewer defects. The wafers polished by the polishing pad of the comparative example have more scratches, and thus, have more defects than the example.

[0059] Based on the above, by controlling the distance between each of the tip heights of the plurality of abrasive particles and the imaginary surface, the chemical mechanical polishing pad dresser of the present invention can effectively reduce the occurrence of killer diamonds so as to obtain the chemical mechanical polishing pad dresser having abrasive particles that are uniformly distributed and have similar tip heights, thereby reducing the probability that the dresser will occur deep grooves on the polishing pad during polishing process, causing wafer scratches, and reducing the yield of the wafer.

[0060] All the ranges provided herein are intended to include each specific range within the given range and the combination of subranges within the given range. In addition, unless otherwise specified, all ranges provided herein include the endpoints of the range. Thus, the range of 1 to 5 specifically includes 1, 2, 3, 4 and 5, and subranges such as 2 to 5, 3 to 5, 2 to 3, 2 to 4, and 1 to 4.

[0061] All publications and patent applications cited in this specification are incorporated herein by reference, and each individual publication or patent application is expressly and individually indicated to be incorporated herein by reference for any and all purposes. In case of any inconsistency between this specification and any publication or patent application incorporated by reference, this specification shall prevail.

[0062] The present invention has been described in detail above, but the above description is merely preferred examples of the present invention and cannot be used to limit the scope of the present invention. That is, all equivalent changes and modifications made according to the claims of the present invention shall still be within the scope of the present invention.

Claims

1. A chemical mechanical polishing pad dresser, comprising:a substrate having an upper surface; andan abrasive layer covering the upper surface of the substrate, the abrasive layer comprising a bonding layer and a plurality of abrasive particles embedded in the bonding layer, and each of the abrasive particles having a tip height, which is a distance between the highest point of each abrasive particle and a surface of the bonding layer;wherein the chemical mechanical polishing pad dresser has an imaginary surface, which is a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles, and wherein the distance between the tip height of each of the abrasive particles and the imaginary surface is a value of the tip variation, which is less than 50 μm; and80% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

2. The chemical mechanical polishing pad dresser according to claim 1, wherein the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

3. The chemical mechanical polishing pad dresser according to claim 1, wherein the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 15 μm.

4. The chemical mechanical polishing pad dresser according to claim 1, wherein 95% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

5. The chemical mechanical polishing pad dresser according to claim 4, wherein 99% or more of the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 30 μm.

6. The chemical mechanical polishing pad dresser according to claim 1, wherein the tip height of each of the abrasive particles is 20 μm to 300 μm.

7. The chemical mechanical polishing pad dresser according to claim 6, wherein a standard deviation of the tip heights is less than 20 μm.

8. The chemical mechanical polishing pad dresser according to claim 1, wherein the abrasive particles are arranged on the substrate in an array or a honeycomb.

9. The chemical mechanical polishing pad dresser according to claim 1, wherein the material of the substrate is selected from a group consisting of metal, ceramic and polymer resin.

10. The chemical mechanical polishing pad dresser according to claim 1, wherein the material of the bonding layer is a brazing material, an electroplating material, a ceramic material, a metal material or a polymer material.

11. The chemical mechanical polishing pad dresser according to claim 1, wherein the abrasive particles are selected from a group consisting of natural diamond, synthetic diamond, polycrystalline diamond, cubic boron nitride, aluminum oxide and silicon carbide.

12. A manufacturing method of a chemical mechanical polishing pad dresser with a leveling surface, comprising:(a) providing a substrate and an abrasive layer having a bonding layer and a plurality of abrasive particles, and the abrasive layer forming on an upper surface of the substrate;(b) heat-curing the bonding layer, and the abrasive layer fixed on the upper surface of the substrate;(c) measuring a tip height of each of the abrasive particles, and obtaining a plane calculated on the basis of the average of each of the tip heights of the plurality of abrasive particles as an imaginary surface; and(d) adjusting the tip heights of the plurality of abrasive particles according to the imaginary surface such that the abrasive particles have a value of the tip variation between the tip height of each of the abrasive particles and the imaginary surface which is less than 50 μm, thereby obtaining the chemical mechanical polishing pad dresser with a leveling surface.

13. The method according to claim 12, wherein the abrasive particles are arranged on the substrate in an array or a honeycomb.

14. The method according to claim 12, wherein the bonding layer is formed on the substrate by brazing, electroplating, ceramic sintering, metal curing or polymer curing.

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