Pad conditioner for delaying crevice corrosion

Abstract

Disclosed is a pad conditioner for delaying crevice corrosion, the pad conditioner being improved in characteristics such as polishing yield and polishing quality while preventing the detachment of abrasive particles. The conditioner comprises: a build-up plating layer that bonds to abrasive particles, thereby binding the abrasive particles; a corrosion-resistant layer which is positioned on the build-up plating layer and prevents crevice corrosion at the boundaries between the abrasive particles and the build-up plating layer; and a protective layer which is positioned on the corrosion-resistant layer and protects the corrosion-resistant layer.

Description

Pad conditioner for delaying crevice corrosion

[0001] The present invention relates to a pad conditioner, and more specifically, to a pad conditioner for maximally delaying crevice corrosion occurring at the interface between abrasive particles and a bonding layer.

[0002] Chemical Mechanical Polishing (CMP) technology flattens a wafer through the relative motion between a platen and a carrier while supplying a slurry to a polishing pad attached to a platen. However, since pressure and relative velocity are applied during polishing, the surface of the polishing pad deforms unevenly as processing time passes, and the pores in the polishing pad become clogged with polishing residues, rendering the polishing pad unable to perform its function. To resolve the uneven deformation and pore clogging of the polishing pad, a CMP pad conditioner is used. The CMP pad conditioner polishes the surface of the polishing pad to correct the deformation and form new micropores. Methods utilizing polishing particles for CMP pad conditioners have been presented, such as in Korean registered patents No. 10-1926449 and No. 10-2013383. In conventional pad conditioners, crevice corrosion occurs due to the CMP slurry when polishing the polishing pad, which can cause the polishing particles to detach.

[0003] FIG. 1 shows photographs of a conventional pad conditioner. In this case, (a) is a pad conditioner (P100) with a build-up plating layer (P10) such as Ni applied, and (b) is a pad conditioner (P110) with a corrosion-resistant layer (P12) coated with a material resistant to crevice corrosion, such as expensive palladium (Pd), on a build-up plating layer (P10) such as Ni. When the build-up plating layer (P10) is applied as in (a), crevice corrosion (A) occurs between the build-up plating layer (P10) and the abrasive particles (P20) due to the CMP slurry, and the abrasive particles (P20) may be detached.

[0004] When a corrosion-resistant layer (P10) is applied as in (b), even if the surface corrosion-resistant layer (P10) inhibits some corrosion, a nickel (Ni) / palladium (Pd) heterogeneous metal galvanic pair is formed, causing the internal build-up plating layer (P10) made of nickel (Ni) to become anodic in crevices, cracks, and exposed areas, thereby accelerating corrosion. In (b), the internal nickel (Ni) build-up plating layer (P10) corrodes, causing a portion of the upper corrosion-resistant layer (P12) adjacent to the abrasive to detach, resulting in crevice corrosion (A). Crevice corrosion (A) induces premature peeling of the corrosion-resistant layer (P12), and due to the acceleration of crevice corrosion (A), the abrasive particles (P20) may eventually detach. When the abrasive particles (P20) detach, characteristics such as polishing yield and polishing quality deteriorate.

[0005] The problem that the present invention aims to solve is to provide a pad conditioner for delaying crevice corrosion that prevents the detachment of abrasive particles while improving characteristics such as abrasive yield and abrasive quality.

[0006] A pad conditioner for delaying crevice corrosion to solve the problem of the present invention comprises abrasive particles, a build-up plating layer bonded to the abrasive particles and bonding the abrasive particles, a corrosion-resistant layer located on the build-up plating layer to prevent crevice corrosion at the boundary between the abrasive particles and the build-up plating layer, and a protective layer located on the corrosion-resistant layer to protect the corrosion-resistant layer.

[0007] In the conditioner of the present invention, the corrosion-resistant layer may be made of a material having a main component identical to that of the build-up plating layer and having a lower hardness than that of the build-up plating layer. The corrosion-resistant layer may be made of a material having a main component identical to that of the protective layer and having a lower hardness than that of the protective layer. The corrosion-resistant layer may be a heat-treatment-insensitive electrolytic nickel plating layer having a hardness value (Hv) increase rate of less than 10% before and after heat treatment. The protective layer may be a fine-grained hardened electrolytic nickel plating layer having a hardness value (Hv) increase rate of 15 to 40% before and after heat treatment.

[0008] In the conditioner of the present invention, the corrosion-resistant layer may be a mixture of a water-repellent agent and a metal binder, and the water-repellent agent may be a fluorine-based water-repellent agent. The fluorine-based water-repellent agent is preferably PTFE, and the content of the PTFE may be 5 to 40 vol% with respect to the total volume of the corrosion-resistant layer. The metal binder is nickel (Ni), and the nickel (Ni) contains phosphorus (P), and the phosphorus (P) may be contained in an amount of 2 to 5 wt% with respect to the total weight of the corrosion-resistant layer, or 5 to 9 wt% with respect to the total weight of the corrosion-resistant layer, or 9 to 12 wt% with respect to the total weight of the corrosion-resistant layer.

[0009] In a preferred conditioner of the present invention, the corrosion-resistant layer may be formed by sequentially or in reverse order stacking a layer having a lower hardness than the build-up plating layer and a layer mixed with a water-repellent agent and a metal binder, wherein the main component is made of the same material as the build-up plating layer. A corrosion-resistant layer made of a platinum group metal or an alloy thereof may be added to the upper surface of the protective layer.

[0010] According to the pad conditioner for delaying crevice corrosion of the present invention, by delaying crevice corrosion, the detachment of abrasive particles is prevented, and characteristics such as abrasive yield and abrasive quality are improved.

[0011] Figure 1 shows photographs of a conventional pad conditioner.

[0012] FIG. 2 is a cross-sectional view showing the first conditioner according to the present invention and a photograph showing a part of the surface.

[0013] FIG. 3 is a cross-sectional view showing a second conditioner according to the present invention and a photograph showing a part of the surface.

[0014] FIG. 4 is a cross-sectional view showing a third conditioner according to the present invention and a photograph showing a part of the cross-section.

[0015]

[0016] FIG. 5 is a cross-sectional view showing a fourth conditioner according to the present invention and a photograph (b) showing a part of the cross-section.

[0017] Figure 6 shows surface SEM images of the first corrosion-resistant layer, the first protective layer, and the second corrosion-resistant layer before and after heat treatment according to the present invention.

[0018] Figure 7 is a graph showing the measurement results of the holding force of abrasive particles in a conventional conditioner and a conditioner according to the present invention.

[0019] Figure 8 shows photographs comparing the third conditioner according to the present invention with a conventional conditioner.

[0020]

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The embodiments described below may be modified in various different forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the invention to those skilled in the art. The drawings are exaggerated for convenience of explanation. Meanwhile, in the drawings, the thickness of the films (layers, patterns) and regions may be exaggerated for clarity. Also, where a film (layer, pattern) is described as being on the upper, upper, lower, or one surface of another film (layer, pattern), it may be formed directly on the other film (layer, pattern) or another film (layer, pattern) may be interposed between them.

[0022] Embodiments of the present invention present a pad conditioner for delaying crevice corrosion, which prevents the detachment of abrasive particles by delaying crevice corrosion and improves characteristics such as polishing yield and polishing quality. To this end, a method for delaying crevice corrosion will be examined in detail, and the effects related to delaying crevice corrosion will be explained in detail. Here, the crevice corrosion occurs at the interface between the abrasive particles and the build-up plating layer, and the build-up plating layer serves to support the abrasive particles. The pad conditioner according to the embodiment of the present invention is used to resolve non-uniform deformation and pore clogging of CMP polishing pads and to prevent the premature detachment of abrasive particles.

[0023] FIG. 2 is a cross-sectional view (a) showing a first conditioner (100) according to an embodiment of the present invention and a photograph (b) showing a part of the surface. However, it is not a drawing in the strict sense, and for convenience of explanation, there may be components not shown in the drawing. At this time, photograph (b) is a photograph of the first conditioner (100) after being immersed in Showa Denko slurry HS-7T915-3 raw solution for 7 days.

[0024] According to FIG. 2, the first conditioner (100) is a CMP pad conditioner comprising a shank (10), a build-up plating layer (12), a first corrosion-resistant layer (14), a first protective layer (16), and abrasive particles (20), and optionally comprising a second protective layer (18). The shank (10) is not limited to, but may be made of general steel, stainless steel, aluminum, magnesium, titanium, aluminum alloy, magnesium alloy, cemented carbide alloy, titanium alloy, or engineering plastic. Although not illustrated, the shank (10) is connected to a driving means that imparts rotational force and a control unit that precisely controls rotational force and movement.

[0025] The build-up plating layer (12) fixes the abrasive particles (20) and is typically formed on the shank (10) by a plating method such as electroplating or electroless plating. The thickness of the build-up plating layer (12) is sufficient to stably fix the abrasive particles (20) and is selected in the range of approximately 50 to 300 μm depending on the size of the abrasive particles. The metal binder in the build-up plating layer (12) may be composed of, for example, bronze, copper, zinc, cobalt, iron, nickel, silver, tin, aluminum, indium, phosphorus, antimony, titanium, tungsten, zirconium, chromium, hafnium, and alloys thereof or mixtures thereof. Among these, nickel and nickel compounds are more preferred. In all embodiments of the present invention below, once the main component of the build-up plating layer (12) is determined, the main components of the first corrosion-resistant layer (14), the second corrosion-resistant layer (30), and the first protective layer (16) are also the same as the main component of the build-up plating layer (12).

[0026] The abrasive particles (20) include alumina (Al2O3), silica (SiO2), silicon carbide (SiC), alumina-zirconia (Al2O3-ZrO2), titanium diboride (TiB2), boron carbide (B4C), cubic boron nitride (CBN), and diamond. Preferably, super abrasive particles such as high-hardness diamond particles or CBN particles are frequently used. These abrasive particles (20) may be used individually or as a mixture of two or more types of particles. Generally, diamond particles are used in the first conditioner (100). The shape of the diamond particles is polyhedral, mostly octahedral or cube octahedral, and recently, octahedral shapes are also used to improve the pad cut rate (PCR). The first corrosion-resistant layer (14) is located on the build-up plating layer (12) to delay crevice corrosion (A in FIG. 1) at the boundary between the abrasive particles (20) and the metal bonding layer (12).

[0027] The first corrosion-resistant layer (14) is formed by a plating method such as electroplating or electroless plating, and the material applied to the build-up plating layer (12), such as bronze, copper, zinc, cobalt, iron, nickel, silver, tin, aluminum, indium, phosphorus, antimony, titanium, tungsten, zirconium, chromium, hafnium, and alloys thereof or mixtures thereof, may be applied, but the corrosion resistance may be increased by making a difference in physical properties such as hardness. Specifically, the first corrosion-resistant layer (14) may have the same main components as the build-up plating layer (12), but the hardness, such as Vickers hardness, may be lower. In the process of manufacturing the first corrosion-resistant layer (14), the abrasive particles (20) form a boundary (14a) on the surface.

[0028] The first protective layer (16) is located on the first corrosion-resistant layer (14). The first protective layer (16) serves to extend the lifespan of the first corrosion-resistant layer (14) by delaying crevice corrosion (A). In other words, if the first protective layer (16) is not present, the lifespan of the first corrosion-resistant layer (14) is shorter compared to when the first protective layer (16) is present. If the lifespan of the first corrosion-resistant layer (14) is short, crevice corrosion (A) occurs relatively quickly, and the detachment of the abrasive particles (20) occurs rapidly. The first protective layer (16) is formed by a plating method such as electroplating or electroless plating, and may be made of the same material as the build-up plating layer (12), for example, bronze, copper, zinc, cobalt, iron, nickel, silver, tin, aluminum, indium, phosphorus, antimony, titanium, tungsten, zirconium, chromium, hafnium, and alloys thereof or mixtures thereof. Specifically, the first protective layer (16) has a higher hardness than the first corrosion-resistant layer (14).

[0029] In some cases, a second protective layer (18) made of platinum group metals such as ruthenium (Ru), rhodium (Rh), and palladium (Pd), or alloys thereof, which are stable against oxidation and crevice corrosion (A), may be added to the upper surface of the first protective layer (16). The second protective layer (18) may be combined with the first protective layer (16) which delays crevice corrosion (A). The second protective layer (18), such as palladium (Pd layer), has the characteristic of being a dense film of noble metal, and when it is necessary to suppress surface corrosion of the plating layer exposed to the outside in a very severe corrosive environment, it limits corrosion by the medium and suppresses initial wear and contamination, thereby slowing down the total corrosion rate. However, there is a possibility that galvanic corrosion may occur locally in sections where the underlying Ni plating layer is partially exposed due to defects, corners, or wear of the second protective layer (18). Accordingly, it is preferable to selectively apply the second protective layer (18) under conditions where the environment, working conditions, and wear level are managed.

[0030] FIG. 3 is a cross-sectional view (a) showing a second conditioner (200) according to an embodiment of the present invention and a photograph (b) showing a part of the surface. At this time, the second conditioner (200) is identical to the first conditioner (100) except for the second corrosion-resistant layer (30). At this time, photograph (b) is a photograph of the second conditioner (200) after being immersed in Showa Denko slurry HS-7T915-3 raw material for 7 days.

[0031] According to FIG. 3, the second conditioner (200) is a CMP pad conditioner and comprises a shank (10), a build-up plating layer (12), a second corrosion-resistant layer (30), a first protective layer (16), and abrasive particles (20), and optionally comprises a second protective layer (18). The second corrosion-resistant layer (30) is preferably formed by a plating method such as electroplating or electroless plating, and is a layer mixed with a water-repellent agent and a metal binder. The water-repellent agents are broadly classified into wax-based, higher alcohol-based, silicone-based, and fluorine-based water-repellent agents. Among these, the fluorine-based water-repellent agent is the most useful because it has the best water-repellent properties due to the basic physical properties of fluorine and can also achieve oil-repellent properties.

[0032] The above-mentioned fluorine-based water repellent includes PTFE (Poly Tetra Fluoro Ethylene), FEP (Fluorinated Ethylene Propylene Copolymer), ETFE (Ethylene Tetra Fluoro Ethylene), PVDF (Poly Vinylidene Fluoride), PVF (Polyvinyl Fluoride), PCTFE (Poly Chloro Trifluoro Ethylene), etc. Among these, the above-mentioned PTFE is most preferable as it is resistant to heat, has an extremely low coefficient of friction, and has excellent chemical resistance. The content of the above-mentioned PTFE is preferably 5 to 40 vol% with respect to the total volume of the second corrosion-resistant layer (30).

[0033] If the content of the above PTFE is less than 5 vol%, the corrosion resistance effect, which is the delay of crevice corrosion (A) by the above PTFE, is significantly reduced. If the content of the above PTFE exceeds 40 vol%, the adhesion between the build-up plating layer and the above PTFE is reduced, making it difficult to maintain the second corrosion-resistant layer (30) stably. In addition, to ensure a uniform distribution of the above PTFE, the average particle size of the above PTFE powder is preferably between tens of nm and 10 µm. If the above average particle size is smaller than tens of nm, the cost of manufacturing the above PTFE powder is excessively high because the average particle size is too small, and it is difficult to secure uniform dispersion due to aggregation, etc. At this time, tens of nm is a lower limit value determined for uniform dispersion. If the above average particle size is larger than 10 µm, the thickness of the corrosion-resistant layer is determined according to the PTFE particle size, and the use of larger particles is restricted.

[0034] The metal binder in the second corrosion-resistant layer (30) may be composed of, for example, bronze, copper, zinc, cobalt, iron, nickel, silver, tin, aluminum, indium, phosphorus, antimony, titanium, tungsten, zirconium, chromium, hafnium, and alloys thereof or mixtures thereof. Among these, nickel and nickel compounds are more preferred. At this time, during the process of manufacturing the second corrosion-resistant layer (30), a boundary (30a) is formed on the surface of the abrasive particle (20).

[0035] FIG. 4 is a cross-sectional view (a) showing a third conditioner (300) according to an embodiment of the present invention and a photograph (b) showing a part of the cross-section. At this time, the third conditioner (300) is identical to the first and second conditioners (100, 200) except for the third corrosion-resistant layer (40). At this time, photograph (b) is an observation by SEM of the third conditioner (300) after it has been immersed in Showa Denko slurry HS-7T915-3 raw solution for 7 days, then cut in cross-section and polished.

[0036] According to FIG. 4, the third conditioner (300) is a CMP pad conditioner and comprises a shank (10), a build-up plating layer (12), a third corrosion-resistant layer (40), a first protective layer (16), and abrasive particles (20), and optionally includes a second protective layer (18). The third corrosion-resistant layer (40) is formed by sequentially stacking the first and second corrosion-resistant layers (14, 30). Specifically, the first protective layer (16) is in contact with the second corrosion-resistant layer (30). As previously described, the second corrosion-resistant layer (30) is preferably formed by a plating method such as electroplating or electroless plating, and is a layer mixed with a water-repellent agent and a metal binder. When the first and second corrosion-resistant layers (14, 30) are stacked sequentially, the effect of delaying crevice corrosion (A) is increased compared to the case where the first and second corrosion-resistant layers (14, 30) exist alone.

[0037] FIG. 5 is a cross-sectional view (a) showing a fourth conditioner (400) according to an embodiment of the present invention and a photograph (b) showing a part of the cross-section. At this time, the fourth conditioner (400) is identical to the first and second conditioners (100, 200) except for the fourth corrosion-resistant layer (50). At this time, photograph (b) is a photograph of the fourth conditioner (400) after being immersed in Showa Denko slurry HS-7T915-3 raw material for 7 days.

[0038] According to FIG. 5, the fourth conditioner (400) is a CMP pad conditioner and comprises a shank (10), a build-up plating layer (12), a fourth corrosion-resistant layer (50), a first protective layer (16), and abrasive particles (20), and optionally includes a second protective layer (18). The fourth corrosion-resistant layer (50) is formed by sequentially stacking the second and first corrosion-resistant layers (30, 14). Specifically, the first protective layer (16) is in contact with the first corrosion-resistant layer (14). The second corrosion-resistant layer (30) is preferably formed by a plating method such as electroplating or electroless plating as described above, and is a layer mixed with a water-repellent agent and a metal binder. When the second and first corrosion-resistant layers (30, 14) are stacked sequentially, the effect of delaying crevice corrosion (A) is increased compared to the case where the second and first corrosion-resistant layers (30, 14) exist alone.

[0039] When the total plating layer forming the conditioner (100-400) of the present invention is 130-160 μm, the abrasive particles (20) are exposed to the plating layer by approximately 20-50 μm. The plating layer refers to the build-up plating layer (12), the first to fourth corrosion-resistant layers (14, 30, 40, 50), the first to second protective layers (16, 18), etc., in the conditioner (100-400) of the present invention. The first protective layer (16) has wear resistance that substantially prevents wear of the first to fourth corrosion-resistant layers (14, 30, 40, 50). The second protective layer (18) has corrosion resistance that substantially suppresses surface corrosion of the first protective layer (16) in a selective environment.

[0040] Meanwhile, when nickel (Ni) is used as a metal binder in the second corrosion-resistant layer (30), a material containing phosphorus (P) or boron (B) in the nickel (Ni) is preferred. When the nickel (Ni) contains phosphorus (P), there are differences in physical properties depending on the phosphorus (P) content. Specifically, in the case of high phosphorus (P) with a phosphorus (P) content of 9 to 12 wt% relative to the total weight of the second corrosion-resistant layer (30), the corrosion resistance is relatively excellent, but the possibility of dissimilar metal corrosion may increase because the potential difference with the nickel (Ni) in other plating layers excluding the second corrosion-resistant layer (30) is relatively larger. However, even in the case of high phosphorus (P), since the main components are the same as those of the build-up plating layer (12) and the first protective layer (16), crevice corrosion does not occur to a degree that is relatively less severe than when conventional palladium (Pd) is used as the corrosion-resistant layer (P12).

[0041] Relatively speaking, in the case of low phosphorus (P) content of 2 to 5 wt% relative to the total weight of the second corrosion-resistant layer (30), the corrosion resistance is relatively poor. In addition, in the case of low phosphorus (P), there is almost no potential difference with nickel (Ni) in other plating layers excluding the second corrosion-resistant layer (30), so heterogeneous metal corrosion hardly occurs, and the hardness is higher compared to high phosphorus (P). Accordingly, a fluorine-based water repellent can be added. The content of the fluorine-based water repellent in the second corrosion-resistant layer (30) can be adjusted according to the content of phosphorus (P). When nickel (Ni) contains boron (B), the toughness is excellent, but the plating layer is not properly formed.

[0042] In the case of a medium phosphorus content (P) of 5 to 9 wt% relative to the total weight of the second corrosion-resistant layer (30), it has an intermediate value of corrosion resistance and hardness between the high phosphorus content (P) and the low phosphorus content (P). Therefore, when selecting low phosphorus, medium phosphorus, or high phosphorus content depending on the purpose of use, it is desirable to select them by considering the hardness of the second corrosion-resistant layer (30) and constraints when plating. Here, 5 wt%, 9 wt%, and 12 wt% represent upper limits.

[0043] While the primary purpose of a conventional corrosion-resistant layer (P12) is surface protection for the nickel (Ni) plating layer, which is the build-up plating layer (P10), the present invention is intended to protect the interface between the abrasive particles (20) and the plating layer. For example, when palladium (Pd), which is the corrosion-resistant layer (P12), is plated on a conventional nickel (Ni) plating layer, if even a small gap occurs between the abrasive particles (20), which have a physically weak structure, and the nickel (Ni) plating layer, the corrosion of the nickel (Ni), which is exposed in only a very small portion, accelerates due to selective corrosion because the exposed surface area is small.

[0044] On the other hand, in the embodiment of the present invention, since the potential difference of each plating layer is small, corrosion proceeds at a generally slow rate over a wide area. In addition, in the embodiment of the present invention, even if the blockage of the slurry liquid flowing in through the gaps of the first protective layer (16), which is the upper nickel (Ni) plating layer, by capillary action is insufficient, the path of the electrolyte is blocked by the nickel (Ni)-PTFE layer of the second corrosion-resistant layer (30). When the path of the electrolyte is blocked, further corrosion is suppressed, thereby reliably preventing the detachment of abrasive particles (20) during the service period. That is, the second corrosion-resistant layer (30) eliminates the heterogeneous metal galvanic mechanism and weakens the electrolytic and electron paths, thereby delaying the rate of corrosion progression and allowing for use without problems for a guaranteed lifespan.

[0045] The embodiment of the present invention has a synergistic effect of inhibiting corrosion due to the stacking plating of the main component being a metal of the same system, such as nickel (Ni), and inhibiting mechanical wear due to the plating of the first protective layer (16). In addition, the main component refers to the main component of the build-up plating layer (12), the first to fourth corrosion-resistant layers (14, 30, 40, 50), and the first protective layer (16). In particular, since the second corrosion-resistant layer (30) contains 5 to 40 vol% of a water-repellent agent, the main component is a metal binder.

[0046] Table 1 shows the Vickers hardness values ​​(Hv) before and after heat treatment for the first corrosion-resistant layer (14), the second corrosion-resistant layer (30), and the first protective layer (16) according to an embodiment of the present invention, and FIG. 6 shows surface photographs of the first corrosion-resistant layer (14), the second corrosion-resistant layer (30), and the first protective layer (16) before (a) and after (b) the heat treatment. Vickers hardness was measured under a load of 0.01 kgf to reduce the influence of the lower layer, and 30 μm plating was applied on a stainless steel substrate to minimize the influence of the lower substrate. However, since the plating thickness is not sufficient, the absolute value of the Vickers hardness may vary due to the influence of the stainless steel used as the substrate, but it is at a level that does not pose a problem in determining the trend of hardness change due to heat treatment.

[0047] At this time, the heat treatment was carried out at 200°C for 2 hours (hr), and the average size of the PTFE powder was less than 1 μm, e.g. 100 to 500 nm, and was 30 vol% of the total volume of the second corrosion-resistant layer (30). In addition, the first corrosion-resistant layer (14) and the first protective layer (16) were formed by electroplating, and the second corrosion-resistant layer (30) was formed by electroless plating. In the second corrosion-resistant layer (30), NiP was used as the metal binder and contained 10 wt% of the total weight of the second corrosion-resistant layer (30).

[0048] Classification Heat Treatment Pre-heat Treatment Post-heat Treatment Change Value Hardness Increase Rate First Protective Layer (16) 479.260 3.712 4.43 0.0 % First Corrosion Resistant Layer (14) 352.2352.60 30.1 % Second Corrosion Resistant Layer (30) 394.449 5.910 1.52 5.7 %

[0049] According to Table 1, the hardness value (Hv) of the first protective layer (16) was 479.2 before heat treatment and 603.7 after heat treatment, and the change value before and after heat treatment was 124.4. The hardness value (Hv) of the first corrosion-resistant layer (14) was 352.2 before heat treatment and 352.6 after heat treatment, and the change value before and after heat treatment was 0.3. The hardness value (Hv) of the second corrosion-resistant layer (30) was 394.4 before heat treatment and 495.9 after heat treatment, and the change value before and after heat treatment was 101.5. That is, the change in hardness value (Hv) of the first protective layer (16) was 124.4, which increased by 30.0% after heat treatment, the change in hardness value (Hv) of the first corrosion-resistant layer (14) was 0.3, which showed almost no change, and the change in hardness value (Hv) of the second corrosion-resistant layer (30) was 101.5, which increased by 25.7% after heat treatment.

[0050] The first corrosion-resistant layer (14) is a heat-treatment-insensitive electrolytic nickel plating layer with a hardness value (Hv) increase rate of less than 10% before and after heat treatment. In contrast, the first protective layer (16) is a fine-grained hardened electrolytic nickel plating layer formed by being in an amorphous or pre-crystalline state before heat treatment and then having fine-grained crystal grains after heat treatment. The hardness value (Hv) of the first protective layer (16) after heat treatment can increase by 15 to 40%, and the average crystal grain size is 10 nm or less. The surfaces of the first protective layer (16), the first corrosion-resistant layer (14), and the second corrosion-resistant layer (30) are confirmed by FIG. 6. As the hardness value (Hv) of the conditioner with the first protective layer (16) added increases, the first protective layer (16) can more effectively protect the first to fourth corrosion-resistant layers (14, 30, 40, 50).

[0051] The increase in hardness due to fine graining occurs in the heat treatment temperature range of 100 to 300℃, and preferably the highest increase in hardness due to fine graining occurs in the range of 150 to 250℃.

[0052] FIG. 7 is a graph showing the measurement results of the holding force of abrasive particles of a conventional conditioner (P110) and a conditioner (100-400) according to an embodiment of the present invention. At this time, the conventional conditioner (P110) and the conditioner (100-400) according to an embodiment of the present invention are as described above.

[0053] According to FIG. 7, the conditioner (100-400) of the present invention and the conventional conditioner (P110) were immersed for 7 days in a corrosive slurry, specifically Showa Denko slurry HS-7T915-3, to induce crevice corrosion (A), and then the holding force was measured using a push-pull gauge while pushing the abrasive particles (20) from the side. This is called a dipping test. At this time, Showa Denko slurry HS-7T915-3 is a slurry in which the problem of abrasive particles (20) falling off frequently occurs. If abrasive particles (20) fall off due to crevice corrosion (A) caused by the slurry used in the conditioner (100-400), a fatal defect may occur if the fallen abrasive particles flow into the wafer polishing location. Accordingly, it is desirable to delay the crevice corrosion (A) as much as possible to prevent the abrasive particles from falling off.

[0054] Before the dipping test, both the conventional conditioner (P110) and the conditioners (100 to 400) according to the embodiment of the present invention had a constant holding power of 2.4 N. However, after the dipping test, the holding power of the conventional conditioner (P110) was 0.2 N, the first conditioner (100) was 1.6 N, the second conditioner (200) was 1.9 N, and the third and fourth conditioners (300, 400) were 2.4 N. In the case of the conventional conditioner (P110), the holding power decreased rapidly, causing the abrasive particles (20) to detach easily. The reason for the rapid decrease in holding power is that gap corrosion (A) occurs between the build-up plating layer (12) and the abrasive particles (P20), causing the abrasive particles (20) to detach.

[0055] In the case of the first and second conditioners (100, 200), the holding power was slightly reduced, but it exhibited a much higher holding power than the conventional conditioner (P110). That is, the first and second conditioners (100, 200) can have sufficient corrosion resistance depending on the state of the slurry and the application thereof. In the case of the third and fourth conditioners (300, 400), the abrasive particles (20) are firmly bonded without a reduction in the holding power, thus showing relatively excellent corrosion resistance. The reason the abrasive particles (20) did not detach is that crevice corrosion (A) was delayed.

[0056] FIG. 8 is a series of photographs comparing a third conditioner (300) according to an embodiment of the present invention with a conventional conditioner (P110). In this case, (a) shows the third conditioner (300) of the present invention, and (b) shows the conventional conditioner (P110).

[0057] According to FIG. 8, the third conditioner (300) of the present invention and the conventional conditioner (P110) are SEM images taken after immersing them in a corrosive slurry, specifically Showa Denko slurry HS-7T915-3 raw material, for 7 days, and then performing a CMP process for 15 minutes while varying the applied pressure. At this time, Showa Denko slurry HS-7T915-3 is a slurry in which the problem of detachment of abrasive particles (20) frequently occurs. As shown, in the third conditioner (300) of the present invention, the abrasive particles (20) are firmly attached without detachment, whereas in the conventional conditioner (P110), there was a part (B) where some abrasive particles (P20) had detached. Specifically, the conventional conditioner (P110) fell off after about 15 minutes at 15 pounds (lbf), but the third conditioner (300) of the present invention did not fall off even after 15 minutes at 30 pounds (lbf). Accordingly, crevice corrosion (A) was delayed by the third corrosion-resistant layer (40) described above, and the present invention actually confirmed more stable adhesion of the abrasive particles (20).

[0058] Meanwhile, as the corrosiveness of the slurry increases, the conventional conditioner (P110) applies a corrosion-resistant layer (P12 in FIG. 1) made of palladium (Pd), etc. To obtain greater corrosion resistance, if the thickness of the conventional corrosion-resistant layer (P12) is increased, more expensive palladium (Pd) is used, thus increasing the cost burden. Even if the thickness of the conventional corrosion-resistant layer (P12) is increased, the conventional conditioner (P110) cannot fundamentally block crevice corrosion (A), so it is difficult to prevent the detachment of abrasive particles (P20). If the abrasive particles (P20) detach, characteristics such as the polishing yield and polishing quality deteriorate. However, the third conditioner (300) of the present invention can prevent crevice corrosion (A) and prevent the detachment of abrasive particles (20) to the maximum extent without using expensive materials such as palladium (Pd). If the abrasive particles (20) do not fall off, characteristics such as abrasive yield and abrasive quality are relatively superior.

[0059] Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art within the scope of the technical concept of the present invention.

[0060] Explanation of the symbols

[0061] 10; Shank 12; Build-up plating layer

[0062] 14, 30, 40, 50; 1st to 4th corrosion-resistant layers

[0063] 16, 18; 1st and 2nd protective layers

[0064] 20; abrasive particles

[0065] 100, 200, 300, 400; 1st to 4th conditioners

Claims

1. Abrasive particles; A plating layer that is bonded to the abrasive particles and binds the abrasive particles; A corrosion-resistant layer positioned on the above-mentioned build-up plating layer to prevent crevice corrosion at the boundary between the abrasive particles and the above-mentioned build-up plating layer; and A pad conditioner for delaying crevice corrosion, characterized by including a protective layer positioned on the corrosion-resistant layer and protecting the corrosion-resistant layer.

2. A pad conditioner for delaying crevice corrosion according to claim 1, characterized in that the corrosion-resistant layer is composed of a material having the same main component as the build-up plating layer and has a lower hardness than the build-up plating layer.

3. A pad conditioner for delaying crevice corrosion according to claim 1, characterized in that the corrosion-resistant layer is made of a material having the same main component as the protective layer and has a lower hardness than the protective layer.

4. A pad conditioner for delaying crevice corrosion according to claim 1, characterized in that the corrosion-resistant layer is a heat-treatment-insensitive electrolytic nickel plating layer having a hardness value (Hv) increase rate of 10% or less before and after heat treatment.

5. A pad conditioner for delaying crevice corrosion according to claim 1, characterized in that the protective layer is a finely atomized hardened electrolytic nickel plating layer having a hardness value (Hv) increase rate of 15 to 40% before and after heat treatment.

6. A pad conditioner for delaying crevice corrosion according to claim 1, wherein the corrosion-resistant layer is characterized by being a mixture of a water-repellent agent and a metal binder.

7. A pad conditioner for delaying crevice corrosion according to claim 6, characterized in that the water repellent is a fluorine-based water repellent.

8. A pad conditioner for delaying crevice corrosion according to claim 7, characterized in that the fluorine-based water repellent is PTFE.

9. A pad conditioner for delaying crevice corrosion according to claim 8, characterized in that the content of the PTFE is 5 to 40 vol% with respect to the total volume of the corrosion-resistant layer.

10. A pad conditioner for delaying crevice corrosion according to claim 6, wherein the metal binder used is nickel (Ni), and the nickel (Ni) contains phosphorus (P).

11. In paragraph 1, the corrosion-resistant layer A layer whose main component is made of the same material as the above-mentioned build-up plating layer and has lower hardness than the above-mentioned build-up plating layer; and A layer mixed with a water-repellent and a metal binder Pad conditioner for delaying crevice corrosion, characterized by being formed by stacking in sequential or reverse order.

12. A pad conditioner for delaying crevice corrosion according to claim 1, characterized in that a corrosion-resistant layer made of a platinum group metal or an alloy thereof is added to the upper surface of the protective layer.

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