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 a 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 there is an average pitch (P) between these abrasive particles; wherein the dresser has a leveling value (R), which is a ratio (H/P) of the tip height (H) to the average pitch (P) of 0.05 to 0.3. The chemical mechanical polishing pad dresser of the present invention can be adjusted for different roughness requirements by controlling the ratio between the tip height and the pitch between the abrasive particles, and different dressers can be manufactured using tip height differences at different pitch, thereby dressing the polishing pad to the appropriate surface roughness.

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 there being an average pitch (P) between these abrasive particles; wherein the dresser has a leveling value (R), which is a ratio (H/P) of the tip height (H) to the average pitch (P) of 0.05 to 0.3.

2. The chemical mechanical polishing pad dresser according to claim 1, wherein the abrasive particles have a particle size(S) of 40 m to 800 m.

3. The chemical mechanical polishing pad dresser according to claim 2, wherein the tip height (H) is 2/7 to of the particle size(S), and the tip height (H) is 11 m to 400 m.

4. The chemical mechanical polishing pad dresser according to claim 1, wherein the average pitch (P) is 200 m to 1500 m.

5. The chemical mechanical polishing pad dresser according to claim 1, wherein the leveling value (R) is 0.076 to 0.215.

6. 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.

7. 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.

8. 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.

9. 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.

10. The chemical mechanical polishing pad dresser according to claim 9, 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.

11. A manufacturing method of a chemical mechanical polishing pad dresser, comprising: (a) providing a substrate and a 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 an average pitch (P) between the plurality of abrasive particles; and (d) controlling a leveling value (R) obtained by a ratio of the tip height (H) to the average pitch (P) to 0.05 to 0.3 to prepare the chemical mechanical polishing pad dresser.

12. The method according to claim 11, wherein the abrasive particles are arranged on the substrate in an array or a honeycomb.

13. The method according to claim 11, 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

[0022] Embodiments of the present invention will be described only by way of example with reference to the accompanying drawings.

[0023] FIG. 1 shows a schematic view of a chemical mechanical polishing pad dresser according to an example of the present invention;

[0024] FIG. 2 shows a schematic view of a large pitch between abrasive particles according to a comparative example of the present invention;

[0025] FIG. 3 shows a schematic view of a small pitch between abrasive particles according to a comparative example of the present invention;

[0026] 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;

[0027] FIG. 5 shows a cutting rate distribution diagram of CMP dressers according to an example and a comparative example of the present invention; and

[0028] FIG. 6 shows a wafer defect rate diagram according to an example and a comparative example of the present invention.

[0029] 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

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] In the prior art, the improvements are made in the tip heights of the abrasive particles. However, the inventors of the present invention have found that when the dresser has a large pitch P1 between abrasive particles (as shown in FIG. 2), the polishing pad dresser has good cutting rate, but may easily form scratches on the polishing pad. When the dresser has a small pitch P2 between abrasive particles (as shown in FIG. 3), the polishing pad dresser may not easily form scratches on the polishing pad, but the polishing pad has a poor surface roughness. In view of the effects of the pitch between abrasive particles on the roughness, the present invention defines a ratio of the tip height H of the abrasive particles to the pitch P between abrasive particles, so that the polishing pad dresser can have a good cutting force and make the polishing pad have a good surface roughness. Referring to FIG. 1, according to an example of the present invention, there is an average pitch P between the abrasive particles 122, and a ratio (H/P) of the tip height H to the average pitch P forms a leveling value R. The leveling value R is 0.05 to 0.3, for example, but not limited to, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a preferred embodiment, the leveling value R is 0.07 to 0.22, for example, but not limited to, 0.071, 0.075, 0.076, 0.08, 0.082, 0.084, 0.09, 0.093, 0.1, 0.14, 0.16, 0.175, 0.18, 0.192, 0.2, 0.21, 0.214, 0.219, 0.2, 0.21, or 0.22. In a more preferred embodiment, the leveling value R is 0.076 to 0.214. The average pitch P used herein refers to an average distance between a plurality of abrasive particles.

[0040] According to an example of the present invention, the abrasive particles 122 have a particle size of 40 m to 800 m, for example, but not limited to, 40 m, 50 m, 60 m, 70 m, 75 m, 80 m, 86 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, 399 m, 400 m, 500 m, 600 m, 700 m, or 800 m. The tip height His 2/7 to , for example, but not limited to, 2/7, 3/7, , , or , of the particle size(S), and the tip height His 11 m to 400 m, for example, but not limited to, 11 m, 15 m, 20 m, 30 m, 40 m, 50 m, 60 m, 70 m, 80 m, 90 m, 100 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 average pitch P between the abrasive particles is 200 to 1500 m, for example, but not limited to, 200 m, 250 m, 300 m, 350 m, 400 m, 450 m, 500 m, 550 m, 600 m, 650 m, 700 m, 750 m, 800 m, 850 m, 900 m, 950 m, 1000 m, 1050 m, 1100 m, 1150 m, 1200 m, 1250 m, 1300 m, 1350 m, 1400 m, 1450 m, or 1500 m.

[0041] Specifically, the leveling value R used herein is defined by the tip height H and the average pitch P between abrasive particles. The tip height H is calculated on the basis of the protrusion rate of the particle size S of the abrasive particle. For example, if the abrasive particle has a particle size S of 399 m and the abrasive particle protrudes 2/7 of the bonding layer, the tip height His S* 2/7, that is, 399* 2/7, so that the tip height His 114 m. If the average pitch P is 1500 m, then the leveling value R is 114/1500=0.076. Additionally, if the abrasive particle has a particle size S of 86 m and the abrasive particle protrudes of the bonding layer, the tip height His 43 m. If the average pitch P is 200 m, then the leveling value R is 43/200=0.215. 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 H is measured in practice, the actual tip height H is not exactly to 2/7 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] By controlling the H/P ratio within the above range, the polishing pad dressed by the polishing pad dresser may have different surface roughnesses, for example, different arithmetical mean roughnesses (Ra) or maximum height roughnesses (Rz). As used herein, the so-called arithmetical mean roughness (Ra) is a parameter defining the surface roughness, and for its definition, reference may be made to JIS B 0601; and specifically, it may be understood as the average absolute value of a contour curve on a reference length. The so-called maximum height roughnesses (Rz) is a parameter for the surface roughness, and for its definition, reference may be made to JIS B 0601; and specifically, it may be understood as the distance between the highest peak and the lowest trough of a contour curve relative to a reference length.

[0043] 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 H of each of the abrasive particles and an average pitch P between the plurality of abrasive particles; and (d) controlling a leveling value R obtained by a ratio of the tip height H to the average pitch P to 0.05 to 0.3 to prepare the chemical mechanical polishing pad dresser.

[0044] 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.

[0045] After the fixation of the abrasive particles is completed, a tip height H of each of the abrasive particles and an average pitch P between the plurality of abrasive particles are measured, and a ratio (H/P) of the tip height H to the average pitch P is calculated to obtain a leveling value R. Finally, the leveling value R is controlled to 0.05 to 0.3 so as to obtain the chemical mechanical polishing pad dresser, thereby preparing the chemical mechanical polishing pad dresser with a leveling surface. The tip height of each of the abrasive particles is 11 m to 400 m. The pitch between the abrasive particles is 200 m to 1500 m. The obtained chemical mechanical polishing pad dresser can be adjusted for different roughness requirements, and different dressers can be manufactured using tip height differences at different pitches, thereby dressing the polishing pad to the appropriate surface roughness.

EXAMPLES

[0046] 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/P Ratios

[0047] 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 and different pitches between abrasive particles are used for testing. The calculation results of tip heights H, average pitches P between abrasive particles, and H/P ratios are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Chemical mechanical polishing pad dressers with different tip heights and different pitches between abrasive particles Example Example Example Comparative Comparative Comparative 1 2 3 Example 1 Example 2 Example 3 Tip height (m) 200 150 37.5 275 9 450 Average pitch (m) 1500 700 200 300 1650 1000 H/P ratio 0.133 0.15 0.214 0.917 0.005 0.45

[0048] 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 pitches between abrasive particles, when the H/P ratio is within the range of 0.05 to 0.3, the dressed polishing pad has fewer holes blocked, and thus has better polishing performance for the wafer. In contrast, when the H/P ratio 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

2. Performance of Polishing Pad

[0049] 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

[0050] 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.

[0051] Based on the above, the chemical mechanical polishing pad dresser of the present invention can be adjusted for different roughness requirements by controlling the ratio between the tip height and the pitch between the abrasive particles, and different dressers can be manufactured using tip height differences at different pitches, thereby dressing the polishing pad to the appropriate surface roughness.

[0052] 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.

[0053] 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.

[0054] 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.