An abrasive article with selective coating and methods of making thereof

Abstract

An abrasive article comprises a substrate, where the substrate comprises a working surface. The working surface has anon-abrasive surface interspersed with abrasive elements. A protective layer is disposed non-uniformly on the working surface. The protective layer forms a conformal coating on the non-abrasive surface and a partial coating on the abrasive elements. The present disclosure also provides methods of making the abrasive articles.

Description

AN ABRASIVE ARTICLE WITH SELECTIVE COATING AND METHODS OF MAKING THEREOFFIELD OF INVENTION

[0001] The present invention relates to abrasive articles. In particular, the present invention relates to abrasive articles with selective protective coating. The present invention also relates to methods of making the abrasive articles.BACKGROUND

[0002] Manufacturing of semiconductor devices and integrated circuits involves repeated deposition and etching of silicon wafers to form multilayered structures. These wafers are polished to remove surface irregularities by chemical mechanical planarization (CMP) polishing method. The polishing method includes use of an abrasive slurry and a polishing pad. During the CMP process, materials are removed from the wafer and these materials accumulate on the polishing pad surface, glazing its surface and degrading its performance, decreasing its lifetime, and increasing wafer defectivity. In order to restore and to remove the deposits on the polishing pad, pad conditioners are used during the CMP process. Pad conditioners are designed to regenerate the polishing pad through an abrading mechanism, which removes the undesirable waste accumulations and recreates asperities on the polishing pad surface.

[0003] However, these abrasive pad conditioners tend to be susceptible to chemical attacks in the highly corrosive environments used in the CMP process, leading to premature failure of the conditioner. Pad conditioners which have metal components, e.g., stainless steel, nichrome, can suffer from metal leaching due to the use of acid slurries during the CMP process. The metal leaching causes formation of defects / pores on the pad conditioners at the surface as well as at the subsurface level, which in turn accelerates corrosion, thereby destructing the integrity of the pad conditioners.

[0004] Accordingly, abrasive pad conditioners have to be designed to be resistant to metal leaching and to withstand corrosive environments. Hence, abrasive pad conditioners with improved stability, corrosion resistant, and reduced metal leaching are much desired.SUMMARY OF INVENTION

[0005] In one embodiment the present disclosure provides an abrasive article comprising a substrate comprising: a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; and a protective layer disposed non-uniformly on the working surface, the protective layer forming a conformal coating on the non-abrasive surface and a partial coating on the abrasive elements.

[0006] In another aspect the present disclosure provides a method of making an abrasive article. The method comprises a) providing a substrate comprising a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; b) laminating the working surface with a sheet to obtain an unmasked region that includes the non-abrasive surface and a first portion of the abrasive elements, and a masked region that masks a second portion of the abrasive elements; c) depositing a protective layer on the unmasked region, wherein the protective layer forms a conformal coating on the non-abrasive surface and the first portion of the abrasive elements; and d) peeling off the sheet from the masked region to expose the second portion of the abrasive elements and obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

[0007] In another aspect the present disclosure, a method of making an abrasive article comprises the steps of a) providing a substrate comprising a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; b) providing a coating over a portion of the abrasive elements to obtain coated abrasive elements having a capped portion and an uncapped portion; c) depositing a protective layer on the working surface, wherein the protective layer forms a conformal coating on the non-abrasive surface and the uncapped portion of the abrasive elements; and d) removing the coating from the capped portion of the abrasive elements to obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

[0008] The above summary of the present disclosure is not intended to describe each embodiment of the present disclosure. The details of one or more embodiments of the disclosure are also set forth in the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0009] The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying figures, in which:

[0010] FIGs. 1A, IB, and 1C depict a schematic diagram of an example abrasive article with a protective layer disposed selectively on the working surface.

[0011] FIGs. 2 A and 2B depict a schematic diagram of an example abrasive article with a protective layer disposed selectively on the working surface.

[0012] FIG. 3 depicts a schematic diagram of a process of manufacturing an abrasive layer with a protective layer disposed selectively on the working surface.

[0013] FIG. 4 depicts a schematic diagram of an abrasive article with capped and uncapped portions.

[0014] FIG. 5 is a chart showing coating loss over time for fully and selectively coated pad conditioner samples.

[0015] These figures are not drawn to scale and are intended merely for illustrative purposes.DETAILED DESCRIPTION

[0016] Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0017] The terms “a,” “an,” or “the” used herein, include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0018] In the methods described herein, the acts can be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0019] Unless otherwise indicated, all numbers expressing quantities or ingredients, measurement of properties and so forth used in the specification and embodiments are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached listing of embodiments can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claimed embodiments, eachnumerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0020] In chemical mechanical planarization (CMP) applications, a polishing system may include a polishing pad, often a polymeric based material, e.g. polyurethane; an abrasive article designed to abrade the pad, e.g. a pad conditioner; a substrate being polished, e.g. a semiconductor wafer; and a working liquid, e.g. a polishing slurry containing abrasive particles, designed to polish / abrade the substrate being polished. During polishing of the wafer with the polishing slurry and the polishing pad, the polishing pad can become glazed over with slurry particles from the slurry, which reduces the polishing pad’s ability to polish the wafer in a consistent manner. Pad conditioners, which may contain an abrading layer, such as a diamond particle abrading layer, a ceramic abrading layer, or a diamond coated ceramic abrading layer, are often used to abrade the polishing pad in order to remove the glaze and / or expose new polishing pad surface, thereby maintaining consistent polishing performance of the pad over long periods of polishing time. However, during use, the pad conditioner can be prone to swarf build-up, e.g. polishing pad material abraded from the polishing pad and / or abrasive particles from the slurry may adhere to the abrading surface of the pad conditioner. These abraded materials and the acids in the polishing slurry subject the conditioners to a corrosive environment. Therefore, the conditioners may be prone to corrosion causing material release in the slurry or polishing pad and then on the wafers. Thus, the abrasive articles, such as pad conditioners, should be corrosion resistant. Accordingly, the present invention provides an abrasive article for use in a corrosive environment and a method of making such an abrasive article.

[0021] The present invention provides an abrasive article with a protective coating. The protective coating on the abrasive article forms a selective conformal coating on the abrasive article such that a portion of the abrading particles stay uncoated, while the metal-based substrate of the abrasive article is covered by the coating. Such selective coating is achieved by the methods described herein. The selective conformal coating ensures that the conditioners retain their usual abrading performance and at the same time the non-abrading surface stays intact unaffected even in a corrosive environment. Accordingly, the present invention provides an abrasive article with a protective coating where the protective coating conforms to the substrate, reduces or hinders metal leaching, does not add expendable material / volume to the working surface, and provides corrosion resistance.Abrasive Articles

[0022] In an embodiment, the present disclosure provides an abrasive article. The abrasive article comprises a substrate. The substrate comprises a working surface and a protective layer disposed non-uniformly on the working surface. The working surface has a non-abrasive surface interspersed with abrasive elements. The protective layer disposed selectively on the working surface forms a conformal protective coating on the non-abrasive surface. The protective layer forms a partial conformal protective coating on the abrasive elements. At least one portion of the abrasive elements is coated with protective layer.

[0023] In some embodiments, the abrasive article comprises a working surface, a primer layer and a protective layer. The working surface has a non-abrasive surface interspersed with abrasive elements. The primer layer is coated on the working surface. The protective layer is disposed non-uniformly over the primer layer. The protective layer disposed selectively on the primer layer coated working surface forms a conformal protective coating on the non-abrasive surface and a partial conformal protective coating on the abrasive elements. At least one portion of the abrasive elements is coated with primer layer and the protective layer disposed on the primer layer.

[0024] In some embodiments, the substrate of the abrasive article is made of a metal or metal alloy. The substrate is made of metal selected from chromium, tungsten, cobalt, titanium, zinc, manganese, silicon, iron, nickel, and copper. The substrate is made of metal alloy comprising two or more metals selected from chromium, tungsten, cobalt, titanium, zinc, manganese, silicon, iron, nickel, and copper. The substrate includes a working surface and a protective layer. The working surface has a non-abrasive surface with abrasive elements. The abrasive elements are engineered features or abrasive particles.

[0025] In some embodiments, the abrasive elements are precisely shaped engineered features or abrasive particles embedded on the non-abrasive surface.

[0026] FIGs. 1A, IB, and 1C depict a schematic diagram of an example abrasive article with a protective layer disposed selectively on the working surface, where the abrasive elements are abrasive particles embedded in the non-abrasive surface. As shown, FIG. 1A depicts a top-view of the abrasive article (100a) comprising a substrate (102) comprising: a working surface (104) with a non-abrasive surface (106) interspersed with abrasive particles (108); and a protective layer (110) disposed non-uniformly on the working surface. FIG. IB depicts a cross-sectional view of the abrasive article (100b) comprising a substrate (102). The substrate (102) comprises a working surface (104). The working surface (104) includes a non-abrasive surface (106) embedded with abrasive particles (108). A protective layer (110) is disposed non-uniformly on the working surface (104). FIG. 1C depicts in particular the protective layer (110) of the abrasive articleforming a conformal coating on the non-abrasive surface (106) and a partial coating on the abrasive particles (108).

[0027] In some embodiments, the abrasive elements are formed of carbide and are about 99% carbide ceramic by weight. In one embodiment, the carbide ceramic is silicon carbide, boron carbide, zirconium carbide, titanium carbide, tungsten carbide or combinations thereof. In some embodiments, the 99% carbide ceramic by weight is substantially silicon carbide. In particular, the carbide ceramic is at least about 90% silicon carbide by weight. The abrasive elements are fabricated without the use of carbide formers and are substantially free of oxide sintering aides. In one embodiment, the abrasive elements include less than about 1% oxide sintering aides. The abrasive elements are also substantially free of silicon and, in particular, include less than about 1% elemental silicon.

[0028] FIGs. 2 A and 2B depict a schematic diagram of an example abrasive article with a protective layer disposed selectively on the working surface, where the abrasive elements are precisely shaped, engineered features. As shown, FIG. 2A depicts a top-view of the abrasive article (200a) comprising a substrate (202). The substrate (202) comprises a working surface (204) with a non-abrasive surface (206) interspersed with engineered features (208). A protective layer (210) is disposed non-uniformly on the working surface (204). FIG. 2B depicts a cross-sectional view of the abrasive article (200b) comprising a substrate (202). The substrate (202) comprises a working surface (204) with a non-abrasive surface (206) interspersed with engineered features (208). A protective layer (210) is disposed non-uniformly on the working surface which forms a conformal coating on the non-abrasive surface (206) and a partial coating on the engineered features (208).

[0029] In some embodiments, the abrasive elements include precisely shaped engineered features, or projections in the abrasive elements that protrude toward a workpiece. The abrasive elements can have any shape or shapes (polygonal or non-polygonal) and can have the same or varying heights. In addition, the abrasive elements can have the same base size or varying base sizes. The abrasive elements may be spaced in a regular or irregular array and may be made into patterns comprised of unit cells.

[0030] In one embodiment, the abrasive elements include a peripheral zone, or an area on the periphery of the abrasive element in which there are no abrasive features. %

[0031] In one embodiment, the engineered features include molded and sintered ceramics spaced in arrays on the non-abrasive surface. In one embodiment, the abrasive element is fabricated from a molded green body. In such cases, the abrasive element is considered a molded abrasive element. The precisely engineered abrasive is ceramic pressed into a mold and sintered. The mold itselfcan be used in the fabrication of the precisely engineered features. In some embodiments, when the abrasive element is molded, it is a subset of the precisely engineered features where the structure is conferred by a molding process. For example, the shape may be the inverse of the mold cavity such that the shape is retained after the abrasive element green body has been removed from the mold. Various ceramic shaping processes may be used, including but not limited to: injection molding, slip casting, die pressing, hot pressing, embossing, transfer molding, gel casting and the like. In one embodiment, the die pressing process is used at room temperature, followed by sintering. Typically, ceramic die pressing near room temperature is referred to as ceramic dry pressing. Ceramic dry pressing typically differs from ceramic injection molding in that it is done at lower temperature, a much smaller amount of binder is used, die pressing is used, and the materials suitable for use as binder are not necessarily limited to thermoplastics.

[0032] In some embodiments, the abrasive elements interspersed on the non-abrasive surface of the working surface of the polishing layer are abrasive particles. In some embodiments, the abrasive particles are embedded on the non-abrasive surface of the working surface. The abrasive particles are made of material including an oxide, a carbide, a nitride, a boride, an oxynitride, an oxyboride, diamond, or combinations thereof. In some embodiments, the abrasive particles can include diamond or cubic boron nitride. In a particular embodiment, the abrasive particles may include diamond.

[0033] The abrasive particles are affixed to the substrate using a matrix material. The matrix material includes a brazing alloy and a sintered corrosion resistant powder selected from at least one of stainless steel, nickel, nichrome, titanium, zirconium, tungsten carbide, and silicon carbide. The brazing alloy comprises at least one of aluminum, boron, carbon, chromium, tungsten, cobalt, titanium, zinc, iron, manganese, or silicon. When heated to a predetermined temperature, the brazing alloy becomes liquid and flows around the abrasive particles. In addition, the brazing alloy reacts with and forms a chemical bond with the abrasive particles. In order to form the chemical bond, the composition of the brazing alloy includes a pre-selected element known to react with the particular abrasive particle, thereby forming the chemical bond. For example, if diamond abrasive particles are used, the brazing alloy may include at least one of the following elements which may react and form a chemical bond with the diamond: chromium, tungsten, cobalt, titanium, zinc, iron, manganese, or silicon. By way of further example, if cubic boron nitride abrasive particles are used, the brazing alloy may include at least one of aluminum, boron, carbon and silicon which may form the chemical bond with the abrasive particles, and if aluminum oxide abrasive particles are used, the brazing alloy may include at least one of aluminum, boron, carbon, and silicon. It will be recognized, however, that the brazing alloy may also contain variousinert elements in addition to the element or elements which react with and form the chemical bond with the abrasive particles.

[0034] A quantity of corrosion resistant powder is admixed with the brazing alloy to improve the bonding properties, enhance the strength, improve the corrosion resistant properties, and reduce the cost of the matrix material. The corrosion resistant powder may include metals and metal alloys including stainless steel, titanium, titanium alloys, zirconium, zirconium alloys, nickel, and nickel alloys. More specifically, the nickel alloy can include nichrome, a nickel alloy including 80% nickel and 20% chrome by weight. Alternatively, the corrosion resistant powder can be formed of ceramics including carbides, such as silicon or tungsten carbide.

[0035] It will thus be understood that the abrasive article may have various kinds of abrasive elements. The examples of abrasive particles as discussed above with reference to FIGs 1A-1C and engineered features as discussed above with reference to FIGs 2A-2B are merely provided for illustration and not as a limitation. There can be other ways of providing abrasive elements on the abrasive article, which are also included within the scope of the present description as will be understood by a person skilled in the art.

[0036] In some embodiments, the abrasive article comprising the substrate comprises a protective layer disposed non-uniformly on the working surface to selectively coat the non-abrasive surface and portions of the abrasive elements. The protective layer comprises a material selected from a polyethylene oxide), polypropylene oxide), silicone-based polymers, methane-based polymers, polytetrafluoroethylene, polytetramethyldisiloxane, electrically conductive polymers, poly(p- xylylene) polymer, or a polymer derived from photopolymerizable, electron beam or thermally curable monomers or oligomers. Examples of methane-based polymers can be found in Wang, Jia, et al. ‘Microbial polymers produced from methane: Overview of recent progress and new perspectives’, Chapter 6 (Microbial and Natural Macromolecules. https: / / doi.org / 10.1016 / B978- 0-12-820084-1.00006-5) (2021). In some embodiments, the protective layer is preferably selected from poly(p-xylylene)N, poly(p-xylylene)C, poly(p-xylylene)D, poly(p-xylylene)F, poly(p- xylylene)HT or derivatives thereof, more preferably is selected from poly(p-xylylene)N, poly(p- xylylene)C, and poly(p-xylylene)D. In some embodiments, the protective layer comprises an inorganic oxide. The inorganic oxide is preferably selected from aluminium oxide, titanium oxide, silicon dioxide or combinations thereof.

[0037] In some embodiments, the abrasive article comprises a working surface coated with a primer layer and a protective layer disposed non-uniformly over the primer layer. In some embodiments, the primer layer comprises a binding material. The binding materials are silicones or non-silicones. The binding material is selected from methacryloxypropyl trimethoxy silane,methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxy silane, methyltriisopropoxysilane, ethyltrimethoxy silane, ethyltriethoxysilane, propyltrimethoxysilane, vinyltrimethoxy silane, vinyltriethoxysilane, modified silanes, non-silicones or combinations thereof. The modified silanes include silane-adhesion promoters containing functional groups including but not limited to acrylate and methacrylate, vinyl and olefin, epoxy, amino, amine, halogen, hydride, carboxylate, phosphonate and sulfonate, hydroxyl, sulfur, phosphine and phosphate, ester, anhydride, azide, aldehyde or combinations thereof. Non-silicones can include, but are not limited to, zinc, phosphate, epoxy, polyester, acrylate and methacrylate -based primers. These non-silicones can be useful as binding material to form a primer layer. The primer layer provides improved adhesion of protective layer on the abrasive article, thereby providing improved stability to the protective layer. The inclusion of primer layer helps in increased adherence of protective layer and hence the abrasive article remains unaffected under harsh corrosive environments for a longer period. Exemplary primer layers are described in US Pat. No. 6,923,840.Methods

[0038] In an embodiment the present disclosure provides a method of making an abrasive article (300), for example, as shown in FIG. 3. The method includes step 300A, which comprises obtaining a substrate (302) as described herein, wherein the substrate comprises a working surface with a non-abrasive surface interspersed with abrasive elements (308). The method includes step 300B, which comprises adhesive laminating (304) the working surface with a sheet, which can be a porous sheet. The sheet may comprise a perforated sheet or a non-perforated sheet. In one embodiment, the sheet comprises a perforated sheet. The perforated sheet is formed by a polymeric or non-polymeric film along with an adhesive. The adhesive used for the purpose of making perforated sheet includes, but is not limited to, silicone, rubber and acrylic based adhesives or hot melt adhesives like polyethlyene, ethylene vinyl acetate copolymers, polyolefins, polypropylene, and ethylene -acrylate. The film of perforated sheet comprises one of polymeric or non-polymeric material selected from paper, polyethylene terephthalate, polyethylenes, nylon, polyvinyl chloride, polypropylene, polycarbonates or any thermoset films. The perforated sheet preferably are made of polymeric film with an adhesive. The perforated sheet has perforations such that on adhesive laminating the working surface, the adhesive end of the perforated sheet masks the top-portion of the abrasive elements. On lamination using the perforated sheet, the nonabrasive surface and a first portion of the abrasive elements are unmasked and a second or top portion of the abrasive elements are masked.

[0039] The method further includes step 300C, which comprises depositing a protective layer (306) on the unmasked region. Deposition of protective layer is carried out by any of the known methods which include but not limited to laser deposition, chemical vapor deposition, physical vapor deposition, plating, spin-coating, dip coating and multi -laminate coating. The protective layer comprises a polymer or an inorganic oxide. The protective layer is coated on the unmasked region using a material selected from comprises a polyethylene oxide), polypropylene oxide), silicone -based polymers, methane-based polymers, polytetrafluoroethylene, polytetramethyldisiloxane, electrically conductive polymers, poly(p-xylylene) polymer, or a polymer derived from photopolymerizable, electron beam or thermally curable monomers or oligomers. In an alternate embodiment, the protective layer comprises an inorganic oxide selected from aluminum oxide, titanium oxide silicon dioxide or combinations thereof.

[0040] The method further includes step 300D, which comprises peeling off the perforated sheet from the masked region to expose the second portion of the abrasive elements.

[0041] The method optionally includes applying a binding material to form a primer layer prior to laminating the working surface with the perforated sheet. The binding material is selected from methacryloxypropyl trimethoxy silane, methyltrimethoxy silane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxy silane, ethyltriethoxy silane, propyltrimethoxysilane, vinyltrimethoxy silane, vinyltriethoxysilane, modified silanes, nonsilicones or combinations thereof. The modified silanes include silane-adhesion promoters containing functional groups including but not limited to acrylate and methacrylate, vinyl and olefin, epoxy, amino, amine, halogen, hydride, carboxylate, phosphonate and sulfonate, hydroxyl, sulfur, phosphine and phosphate, ester, anhydride, azide, aldehyde or combinations thereof. Nonsilicones include, but are not limited to, zinc, phosphate, epoxy, polyester, and acrylate and methacrylate-based primers. Non silicones are useful as binding material to form a primer layer.

[0042] In one embodiment, the method of making an abrasive article includes the following steps. Coating a substrate comprising working surface having a non-abrasive surface interspersed with abrasive elements, using a binding material to form a primer layer on the working surface. Laminating the working surface using a perforated sheet to obtain an unmasked region that includes the non-abrasive surface and a first portion of the abrasive elements, and a masked region that masks a second portion of the abrasive elements. Depositing a protective layer on the unmasked region, wherein the protective layer forms a conformal coating on the non-abrasive surface and the first portion of the abrasive elements and subsequently peeling off the perforated sheet from the masked region to expose the second portion of the abrasive elements and therebyto obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

[0043] In another embodiment the present disclosure provides a method of making an abrasive article. The method includes the steps of a) providing a substrate comprising a working surface having a non-abrasive surface interspersed with abrasive elements; b) providing a coating over a portion of the abrasive elements to obtain coated abrasive elements having a capped portion and an uncapped portion; c) depositing a protective layer on the working surface, wherein the protective layer forms a conformal coating on the non-abrasive surface and the uncapped portion of the abrasive elements; and d) removing the coating from the capped portion of the abrasive elements to obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

[0044] In some embodiments, the method of making an abrasive article comprises a) providing a substrate comprising a working surface having a non-abrasive surface interspersed with abrasive elements; b) applying a silane primer over the working surface to form a primer layer; c) providing a coating over a portion of the abrasive elements to obtain coated abrasive elements having a capped portion and an uncapped portion; d) depositing a protective layer on the working surface; and e) removing the coating from the capped portion of the abrasive elements to obtain the abrasive article. The protective layer is disposed selectively on the working surface and forms a conformal coating on the non-abrasive surface and the uncapped portion of the abrasive elements.

[0045] In some embodiments, the method includes applying a silane primer over the working surface, where the silane primer is selected from methacryloxypropyl trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxy silane, methyltriisopropoxysilane, ethyltrimethoxy silane, ethyltriethoxysilane, propyltrimethoxysilane, vinyltrimethoxy silane, vinyltriethoxysilane, modified silanes, non-silicones or combinations thereof. The modified silanes include silane-adhesion promoters containing functional groups including but not limited to acrylate and methacrylate, vinyl and olefin, epoxy, amino, amine, halogen, hydride, carboxylate, phosphonate and sulfonate, hydroxyl, sulfur, phosphine and phosphate, ester, anhydride, azide, aldehyde or combinations thereof. Non-silicones include, but are not limited to, zinc, phosphate, epoxy, polyester, and acrylate and methacrylate-based primers. Non-silicones are useful as binding material to form a primer layer.

[0046] In one embodiment, as shown in FIG. 4, in an alternative method 400, plastic or non-plastic end caps can be directly coated or capped onto abrasive articles (408). This capping step can be carried out over portions of the abrasive elements to obtain coated abrasive elements (408) with a capped portion (402) and an uncapped portion (404). The coating comprises one or more layersof siloxane polymer, polyethylene terephthalate, an epoxy, an acrylate, ethyl vinyl acetate, polypropylene and polyethylene. In some embodiments, the coating can be transferred from a removable laminating transfer sheet.

[0047] In some embodiments, the method includes depositing a protective layer on the working surface by any of the known methods which include but not limited to laser deposition, chemical vapor deposition, physical vapor deposition, plating, spin-coating, dip coating and multi-laminate coating. The protective layer comprises a polymer or an inorganic oxide. The protective layer is coated on the on the working surface using a material selected from comprises a polypropylene oxide), silicone -based polymers, methane-based polymers, polytetrafluoroethylene, polytetramethyldisiloxane, electrically conductive polymers, poly(p-xylylene) polymer, polyethylene oxide), or a polymer derived from photopolymerizable, electron beam or thermally curable monomers or oligomers. In an alternate embodiment, the protective layer comprises an inorganic oxide selected from aluminum oxide, titanium oxide silicon dioxide or combinations thereof. The protective layer is coated such that it forms conformal coating selectively on the nonabrasive surface and the uncapped portion of the abrasive elements. After depositing the protective layer, the coating on the capped portion of the abrasive elements can be removed. In some embodiments, removing the coating on the capped portion includes buffing the capped portion of the abrasive elements with a buffing pad. In some embodiments, removing the coating on the capped portion includes stripping or removing the capped portion with a tape. Thus, an abrasive article with a selective conformal coating of the protective layer formed on the non-abrasive surface and on the sides of the abrasive elements can be obtained.Applications

[0048] Abrasive articles of the present disclosure having a protective layer of conformal coating on the non-abrasive surface and a partial coating on the abrasive elements may be used in conventional Chemical Mechanical Planarization (CMP) processes. Various materials may be polished or planarized in such conventional CMP processes, including, but not limited to: copper, copper alloys, aluminum, tantalum, tantalum nitride, tungsten, titanium, titanium nitride, nickel, nickel-iron alloys, nickel-silicide, germanium, silicon, silicon nitride, silicon carbide, silicondioxide, oxides of silicon, hafnium oxide, materials having a low dielectric constant, and combinations thereof. The pad conditioners may be configured to mount onto conventional CMP tools in such CMP processes and run under conventional operating conditions. In one embodiment, the CMP process is run at a range of rotational speeds between about 20 RPM and about 150 RPM, at a range of applied load of between about 1 lb and about 90 lbs, and sweeping back and forthacross the pad at a rate of between about 1 and about 25 sweeps per minute, utilizing conventional sweep profiles, such as sinusoidal sweeps or linear sweeps. As would be apparent to one of ordinary skill in the art given the present disclosure, other CMP processing speeds and loads can also be applied.EXAMPLES

[0049] The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those skilled in the art.Materials used

[0050] For the purpose of the present disclosure the following materials are used for preparing the abrasive article.Example 1Makins of Abrasive articles-Method 1

[0051] Sintered abrasive (SA) conditioner (substrate) comprising diamond abrasive particles was adhesive laminated using a perforated sheet. A sheet of 2 mils thick VHB (Very High Bond) adhesive laminated to a 5 mil thick PET (polyethylene terephthalate) film was perforated using a laser to have perforations of 100- 150pm average size. This perforated sheet was then laminated to the conditioner using hydraulic press at 500 - 20001b Lamination using the perforated sheet resulted in the conditioner comprising masked regions and unmasked regions. The top portion of the diamond particles were masked with perforated sheet. The sides of diamond particles and the non-abrasive portion of the conditioner were unmasked and were exposed for further coating. The adhesive laminated conditioner was then subjected to deposition of protective layer. Poly(p- xylylene) coating was deposited using a vapor deposition polymerization (VDP) process in a Labcoater 2 PDS 2010 system (Specialty coating systems, Indianapolis, IN). After completion of poly(p-xylylene) coating, the perforated sheet was removed by peeling off. Thus, the conditioner was selectively coated with poly(p-xylylene) such the non-abrasive parts and the portion of diamond particles have the conformal coating.

[0052] In another example, the protective layer was formed by depositing aluminum oxide with titanium oxide by vapor deposition method.

[0053] In another example, prior to adhesive lamination, a silane primer was applied on the conditioner. The silane primer aided in increased adhesion of the polymer coating on the conditioner.Example 2Makins of Abrasive articles-Method 2

[0054] An abrasive article with selective conformal coating of the protective layer was made by the method described herein. In this method, the conditioner comprising diamond abrasive particles was selectively masked with polyvinyl siloxane, wherein the coating of siloxane was transferred and applied only on the tips of the diamond particles to form a capped portion. Then a layer of poly(p-xylylene) was vapor deposited on the conditioner such that poly(p-xylylene) layer covered the non-abrasive surface and the uncapped portion of diamond particles. The siloxane cap on the diamond particles was then removed by buffing the capped portion with a buffing pad. The buffing pad was able to clean off all of the capped tips of diamond particles and did not destroy the poly(p-xylylene) coating on the base of the diamonds (uncapped portion). Thus, the obtained conditioner had protective poly(p-xylylene) covering the non-abrasive surface and the uncapped portion of the diamond particles.

[0055] In another example, the protective layer was formed by depositing aluminum oxide with titanium oxide by vapor deposition method.

[0056] In another example, prior to depositing poly(p-xylylene), a silane primer was applied on the conditioner. The silane primer aided in increased adhesion of the poly(p-xylylene) coating on the conditioner.Example 3Corrosion resistance of the abrasive articles

[0057] The as-prepared selectively coated conditioner as mentioned in Example 1 above, were immersed inside a glass or plastic container filled with AGC 5003 chemical mechanical planarization slurry for 24 hours at 25 °C. The slurry was then analysed using Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (I CP -MS) for leaching metals from the conditioners. The same experiment was carried out for uncoated and uniformly coated conditioners and the results are shown in Table 1 below.Table 1

[0058] From Table 1 it could be observed that depositing a coating on the conditioner provided protection against metal leaching, as compared to an uncoated conditioner. It was also observed that the measured metal leaching results experienced by a conditioner with a uniform coating and a conditioner with a non-uniform (or selective) coating were both below detection limit.

[0059] In addition to the metal leaching tests, Fig. 5 provides a chart comparing changes in coating coverage over time for uniformly vs non-uniformly coated conditioners. Using a benchtop scale version of a standard CMP processing technique, a uniformly coated conditioner was compared to a non-uniformly coated conditioner to determine the loss of coating over time when using the same CMP polishing process. As was observed under magnification, the uniformly coated conditioner experienced much higher loss of coating over time. One potential advantage of the non-uniformly coated pad condition is that the abrasive particles of the non-uniformly coated pad conditioner can directly touch the polishing pad without the need for any pre-conditioning time to remove the coating.

Claims

What is claimed is:

1. An abrasive article comprising a substrate, wherein the substrate comprises: a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; and a protective layer disposed non-uniformly on the working surface, the protective layer forming a conformal coating on the non-abrasive surface and a partial coating on the abrasive elements.

2. The abrasive article of claim 1 comprising a primer layer coated on the working surface, wherein the protective layer is disposed non-uniformly over the primer layer.

3. The abrasive article of claim 2, wherein the primer layer comprises a binding material selected from methacryloxypropyl trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxy silane, ethyltriethoxysilane, propyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, modified silanes, non-silicones, or combinations thereof.

4. The abrasive article of claim 1, wherein the abrasive elements comprise one or more of engineered features and abrasive particles.

5. The abrasive article of claim 4, wherein the engineered features include molded and sintered ceramics spaced in arrays on the non-abrasive surface.

6. The abrasive article of claim 4, wherein the abrasive particles are embedded in the non-abrasive surface.

7. The abrasive article of claim 1, wherein the abrasive elements are formed by a material selected from diamond, carbides, oxides, nitrides, or combinations thereof.

8. The abrasive article of claim 1, wherein the protective layer comprises a polyethylene oxide), polypropylene oxide), silicone-based polymers, methane-based polymers, polytetrafluoroethylene, polytetramethyldisiloxane, electrically conductive polymers, poly(p-xylylene) polymer, or a polymer derived from photopolymerizable, electron beam or thermally curable monomers or oligomers.

9. The abrasive article of claim 1, wherein the protective layer comprises an inorganic oxide, preferably selected from aluminum oxide, titanium oxide silicon dioxide or combinations thereof.

10. The abrasive article of claim 1, wherein the substrate is made of a metal or a metal alloy, selected from chromium, tungsten, cobalt, titanium, zinc, manganese, silicon, iron, nickel, copper, or combinations thereof.

11. A method of making an abrasive article, the method comprising: a. providing a substrate comprising a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; b. laminating the working surface with a perforated sheet to obtain an unmasked region that includes the non-abrasive surface and a first portion of the abrasive elements, and a masked region that masks a second portion of the abrasive elements; c. depositing a protective layer on the unmasked region, wherein the protective layer forms a conformal coating on the non-abrasive surface and the first portion of the abrasive elements; and d. peeling off the perforated sheet from the masked region to expose the second portion of the abrasive elements and obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

12. The method of claim 11, comprising applying a binding material over the working surface prior to laminating the working surface to form a primer layer.

13. The method of claim 11, wherein the perforated sheet is formed by a polymeric film, a non-polymeric film or combinations thereof.

14. The method of claim 11, wherein depositing the protective layer comprises depositing a polymer or an inorganic oxide by laser deposition, vapor deposition, plating, spin-coating, dip coating or multi-laminate coating.

15. The method of claim 14, wherein the polymer comprises poly(p-xylylene), and the inorganic oxide is selected from titanium oxide or silicon dioxide.

16. A method of making an abrasive article, the method comprising: a. providing a substrate comprising a working surface, the working surface having a non-abrasive surface interspersed with abrasive elements; b. providing a coating over a portion of the abrasive elements to obtain coated abrasive elements having a capped portion and an uncapped portion; c. depositing a protective layer on the working surface, wherein the protective layer forms a conformal coating on the non-abrasive surface and the uncapped portion of the abrasive elements; and d. removing the coating from the capped portion of the abrasive elements to obtain the abrasive article comprising the protective layer disposed selectively on the working surface.

17. The method of claim 16 comprising applying a silane primer over the working surface, prior to providing the coating, to form a primer layer.

18. The method of claim 17, wherein the coating comprises a siloxane polymer, polyethylene terephthalate, an epoxy, an acrylate, ethyl vinyl acetate, polypropylene, polyethylene, or combinations thereof.

19. The method of claim 16, wherein removing the coating comprises buffing the capped portion of the abrasive elements with a buffing pad.

20. The method of claim 16, wherein removing the coating comprises removing the capped portion of the abrasive elements with a tape.

21. The method of claim 16, wherein depositing the protective layer comprises depositing a polymer or an inorganic oxide by laser deposition, vapor deposition, plating, spin-coating, dip coating or multi-laminate coating.

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