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 (H), which is a distance between the highest point of each abrasive particle and a surface of the bonding layer, and the abrasive particles have a particle size(S) of 40 m to 800 m; wherein the dresser has a leveling value (R) of 0.1 to 0.7 for the ratio of the tip height (H) to the particle size(S). The chemical mechanical polishing pad dresser of the present invention controls the ratio of the tip height to the particle size of the abrasive particles, thereby preventing the abrasive particles with different particle sizes referenced the same tip height as a baseline, and causing the polishing pad dresser to have incorrect working points of the abrasive particles, which further reduce defects such as scratch the wafer during processing.

Claims

1. 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, each of the abrasive particles has a tip height (H), which is a distance between the highest point of each abrasive particle and a surface of the bonding layer, and the abrasive particles have a particle size(S) of 40 m to 800 m; wherein the dresser has a leveling value (R) of 0.1 to 0.7 for the ratio of the tip height (H) to the particle size(S).

2. The chemical mechanical polishing pad dresser according to claim 1, wherein the tip height (H) is to of the particle size(S), and the tip height (H) is 8 m to 400 m.

3. The chemical mechanical polishing pad dresser according to claim 1, wherein the leveling value (R) is 0.2 to 0.5.

4. 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.

5. 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.

6. 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.

7. 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.

8. The chemical mechanical polishing pad dresser according to claim 7, wherein the tip of the abrasive particle is in a shape of a blade, a cone, an arc, a cylinder, a pyramid or a prism.

9. A manufacturing method of a chemical mechanical polishing pad dresser, 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 (H) of each of the abrasive particles and a particle size(S) of the plurality of abrasive particles; and (d) controlling a leveling value (R) obtained by a ratio of the tip height (H) to the particle size(S) of the abrasive particles to 0.1 to 0.7 to prepare the chemical mechanical polishing pad dresser.

10. The method according to claim 9, wherein the abrasive particles are arranged on the substrate in an array or a honeycomb.

11. The method according to claim 9, wherein the bonding layer is formed on the substrate by brazing, electroplating, ceramic sintering, metal curing or polymer curing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Embodiments of the present invention will be described only by way of example with reference to the accompanying drawings.

[0021] FIG. 1 shows a schematic view of a chemical mechanical polishing pad dresser according to an example of the present invention;

[0022] FIG. 2 shows a schematic view of a chemical mechanical polishing pad dresser having abrasive particles with a large particle size according to a comparative example of the present invention;

[0023] FIG. 3 shows a schematic view of a chemical mechanical polishing pad dresser having abrasive particles with a small particle size according to a comparative example of the present invention;

[0024] FIG. 4 shows SEM results of surfaces of polishing pads dressed by CMP dressers according to an example and a comparative example of the present invention;

[0025] FIG. 5 shows a cutting rate distribution diagram of CMP dressers according to an example and a comparative example of the present invention; and

[0026] FIG. 6 shows a wafer defect rate diagram according to an example and a comparative example of the present invention.

[0027] 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

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The terms abrasive particles, 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 particles 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.

[0037] Referring to FIG. 2 and FIG. 3, since the abrasive particles 122 with different particle sizes are covered by the bonding layer to different degrees, if only the tip height of the abrasive particles is used as the criterion for judging the polishing performance of the dresser, it will cause the problem of insufficient coverage of the abrasive particles. For example, under the restriction of the same tip height H, the exposed abrasive particle height H1 of the abrasive particle with a large particle size S1 is smaller than the particle size S1 (FIG. 2), and the exposed abrasive particle height H2 of the abrasive particle with a small particle size S2 is greater than one half of the particle size S2 (FIG. 3), which causes insufficient coverage of the abrasive particle with a small particle size S2, causing a high tendency to breakage during polishing.

[0038] Based on the above, if the abrasive particles with a large particle size S1 and the abrasive particles with a small particle size S2 that have the same tip height H difference range are further used to produce a dresser, due to insufficient coverage of the most protruding abrasive particles with a small particle size S2, the abrasive particles with a small particle size S2 may easily fall off when dressing the polishing pad, causing scratches on the wafer. Therefore, the tip height difference significantly magnifies the effect of the particle size difference. In view of this, the inventors of the present invention discover the effect of the particle size on the polishing pad dresser. Therefore, by combining different particle sizes of abrasive particles with different tip heights of abrasive particles, the abnormal polishing pad dresser produced due to the height difference can be avoided, and the effect of the dresser on the wafer defects during polishing can be further reduced. Still referring to FIG. 1, according to an example of the present invention, a ratio (H/S) of the tip height H to the particle size S of the abrasive particles forms a leveling value R, and the leveling value R is 0.1 to 0.7, for example, but not limited to, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.55, 0.57, 0.58, 0.6, 0.61, 0.63, 0.65, 0.68, 0.69, or 0.7. In a preferred embodiment, the leveling value R is 0.2 to 0.5. The particle size S herein refers to the maximum radius of the abrasive particle. Abrasive particles in different shapes, for example, abrasive particles that are circular, rhombic and elliptical, have different radii, so herein, the maximum radius of the shape is used to represent the particle size.

[0039] According to an example of the present invention, the abrasive particles 122 have a particle size S of 40 m to 800 m, for example, but not limited to, 40 m, 50 m, 60 m, 70 m, 75 m, 80 m, 90 m, 100 m, 110 m, 120 m, 130 m, 140 m, 150 m, 160 m, 170 m, 180 m, 190 m, 200 m, 210 m, 220 m, 230 m, 240 m, 250 m, 260 m, 270 m, 280 m, 290 m, 300 m, 310 m, 320 m, 330 m, 340 m, 350 m, 360 m, 370 m, 380 m, 390 m, 400 m, 500 m, 600 m, 700 m, or 800 m. The particle size of the abrasive particles 122 affects the polishing performance of the chemical mechanical polishing pad. When the abrasive particles 122 face the chemical mechanical polishing pad to be dressed, the abrasive particles 122 with different particle sizes form scores with different widths and densities on the polishing pad, thereby changing the roughness of the polishing pad and improving the polishing effect of the polishing pad.

[0040] According to an example of the present invention, the tip height H of the abrasive particle 122 is to , for example, but not limited to, , , , , or , of the particle size(S), and the tip height His 8 m to 400 m, for example, but not limited to, 8 m, 9 m, 10 m, 11 m, 12 m, 13 m, 14 m, 15 m, 20 m, 25 m, 30 m, 35 m, 40 m, 45 m, 50 m, 55 m, 60 m, 65 m, 70 m, 75 m, 80 m, 85 m, 90 m, 95 m, 100 m, 105 m, 110 m, 115 m, 120 m, 125 m, 130 m, 135 m, 140 m, 145 m, 150 m, 155 m, 160 m, 165 m, 170 m, 175 m, 180 m, 185 m, 190 m, 195 m, 200 m, 250 m, 300 m, 350 m, or 400 m. The tip height of the abrasive particle 122 will also affect the polishing performance of the chemical mechanical polishing pad, and the abrasive particles with different tip heights will form scores of different depths on the polishing pad, which will also form different roughnesses, thereby improving the polishing effect of the polishing pad.

[0041] Specifically, the leveling value R used herein is defined by the tip height H and the particle size S of the abrasive particles. The tip height H is calculated on the basis of the protrusion rate of the particle size S. For example, if the particle size S of the abrasive particle is 800 m and the abrasive particle protrudes of the bonding layer, the tip height H is particle size S*, that is, 800*, so that the tip height His 400 m. If the particle size S is 800 m, then the leveling value R is 400/800=0.5. Additionally, if the abrasive particle has a particle size S of 40 m and the abrasive particle protrudes of the bonding layer, the tip height His 8 m. If the particle size S is 40 m, then the leveling value R is 8/40=0.2. However, it should be noted that although the tip height H is defined in the present invention according to different protrusion rates of the particle size S, when the tip height His measured in practice, the actual tip height H is not exactly to of the particle size S as defined by the present invention, and there may be some differences due to the height deviation of the dresser during production. Therefore, the present invention determines whether the dresser conforms to an ideal surface by measuring the leveling value R.

[0042] Another aspect of the present invention provides a manufacturing method of a chemical mechanical polishing pad dresser, 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 of each of the abrasive particles and a particle size of the plurality of abrasive particles; and (d) controlling a leveling value R obtained by a ratio of the tip height H to the particle size S of the abrasive particles to 0.1 to 0.7 to prepare the chemical mechanical polishing pad dresser.

[0043] 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.

[0044] After the fixation of the abrasive particles is completed, a tip height H of each of the abrasive particles and a particle size S of the plurality of abrasive particles are measured, and a ratio (H/S) of the tip height H to the particle size S is calculated to obtain a leveling value R. Finally, the leveling value R is controlled to 0.1 to 0.7 so as to obtain the chemical mechanical polishing pad dresser, thereby preparing the chemical mechanical polishing pad dresser with a leveling surface. The abrasive particles have a particle size of 40 m to 800 m. The tip height of each of the abrasive particles is 8 m to 400 m. The obtained chemical mechanical polishing pad dresser has good accuracy, which prevents the polishing pad dresser from having incorrect working points of the abrasive particles and can further reduce defects such as scratch the wafer during processing.

Examples

[0045] 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. Preparation of Chemical Mechanical Polishing Pad Dressers with Different H/S Ratios

[0046] 3 chemical mechanical polishing pad dressers (Examples 1 to 3) and 3 chemical mechanical polishing pad dressers (Comparative Examples 1 to 3) with different tip heights H and different particle sizes S of abrasive particles are used for testing. The calculation results of tip heights H, particle sizes S of abrasive particles, and H/S ratios are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Chemical mechanical polishing pad dressers with different tip heights and different particle sizes Example Example Example Comparative Comparative Comparative 1 2 3 Example 1 Example 2 Example 3 Tip height 200 150 10 5 30 640 (m) Particle 400 325 65 52 35 890 size (m) H/S ratio 0.2 0.46 0.15 0.096 0.85 0.72

2. Performance of Polishing Pad

[0047] After the polishing pad is dressed by the CMP dressers of the examples and the comparative examples, the result is shown in FIG. 4. FIG. 4(A) shows an undressed polishing pad, FIG. 4(B) shows a polishing pad dressed by the CMP dresser of the example, and FIG. 4(C) shows a polishing pad dressed by the CMP dresser of the comparative example. The result shows that in a case that a CMP dresser has different tip heights and different particle sizes of abrasive particles, when the H/S ratio is within the range of 0.1 to 0.7, the dressed polishing pad has fewer holes blocked, and thus has better polishing performance for the wafer. In contrast, when the H/S ratio or the particle size S of the abrasive particles is not within the range defined by the present invention, the dressed polishing pad has more holes blocked, and thus has poor polishing performance.

3. Cutting Rate Distribution

[0048] Referring to FIG. 5, 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.

4. Wafer Defect Rate

[0049] Referring to FIG. 6, 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.

[0050] Based on the above, the chemical mechanical polishing pad dresser of the present invention controls the ratio of the tip height to the particle size of the abrasive particles, thereby preventing the abrasive particles with different particle sizes referenced the same tip height as a baseline, and causing the polishing pad dresser to have incorrect working points of the abrasive particles. Moreover, different tip height differences are set according to different particle sizes, which further reduce defects such as scratch the wafer during processing.

[0051] 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.

[0052] 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.

[0053] 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.