Abrasive elements having precisely shaped features, abrasive articles made from the abrasive elements, and methods for making the abrasive articles - Patents.com

Abstract

The abrasive article includes a plurality of abrasive features disposed on one or more abrasive elements, each of which includes a base having a first major surface from which a plurality of abrasive features extend. The first set of the plurality of abrasive features has (i) an average height H 1avg , (ii) H 1avg and (iii) has a standard deviation of less than 10% of the number of polishing features.

Description

[Technical field]

[0001] The present disclosure relates generally to abrasives and abrasive articles. [Background technology]

[0002] Various abrasive articles are described, for example, in U.S. Pat. No. 9,956,664 and PCT Publication Nos. WO 2014 / 022462 and WO 2014 / 022465. [Summary of the Invention] In some embodiments, an abrasive article is provided. The abrasive article includes a plurality of abrasive features disposed on one or more abrasive elements. Each of the one or more abrasive elements includes a base having a first major surface from which a plurality of abrasive features extend. A first set of the plurality of abrasive features has (i) an average height H 1avg , (ii) H 1avg and (iii) comprises between 5 and 130 abrasive features. In some embodiments, a method of conditioning a polishing pad is provided that includes performing a CMP operation using the polishing pad and then contacting a working surface of the polishing pad with a working surface of an abrasive article as described above. [Brief description of the drawings]

[0003] [Figure 1A] FIG. 1 is a schematic top view of an abrasive article according to some embodiments of the present disclosure.

[0004] [Figure 1B] FIG. 1B is a schematic side view of the abrasive article of FIG. 1A.

[0005] [Figure 2A] FIG. 1 is a schematic top view of an abrasive article according to some embodiments of the present disclosure.

[0006] [Figure 2B] FIG. 2B is a schematic side view of the abrasive article of FIG. 2A.

[0007] [Figure 3A] 1A-1D are schematic top views of polishing elements according to some embodiments of the present disclosure.

[0008] [Figure 3B] FIG. 3B is a schematic side view of the polishing element of FIG. 3A.

[0009] [Figure 4] FIG. 13 is a scatter plot of CP4 average pad wear rate versus Log10 of number of primary polishing features.

[0010] These figures are not drawn to scale and are intended for illustrative purposes only. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The semiconductor and microchip industries rely on a number of chemical-mechanical planarization (CMP) processes during device manufacturing. These CMP processes are used to planarize the surface of wafers in the creation of integrated circuits. Typically, they utilize an abrasive slurry and a polishing pad. During the CMP process, material is removed from the wafer and polishing pad, and by-products are formed. These can accumulate on the surface of the polishing pad, smoothing its surface, reducing its performance, shortening its life, and increasing wafer defects. To address these issues, pad conditioners are designed to remove unwanted debris that has accumulated on the surface of the polishing pad, restoring the performance of the polishing pad through a polishing mechanism that reforms the irregularities.

[0012] Pad conditioners for CMP often include an abrasive element or elements affixed to a carrier. Different carriers are designed for convenient attachment to different configurations of CMP equipment. Several types of abrasive elements used in CMP pad conditioners utilize a CVD diamond film deposited on a suitable substrate. The substrate is often formed or machined to present macro- or microstructural features. Microreplication is utilized, for example, in 3M TRIZACT B6-1900-5S2 and B75-2990-5S2 pad conditioners. These conditioners include abrasive elements that present an array of pyramidal features coated with a CVD diamond film to a pad to be conditioned in a CMP process. Depending on the design details, it is possible to have features that are essentially coplanar at different discrete levels, such as the highest primary level, secondary level, tertiary level, etc. The areal density and height differences of primary, secondary, and lower level features are among the design parameters that affect pad wear rate, pad texture, and conditioner life for a particular CMP process.

[0013] As the nature of CMP polishing pads shifts toward very soft, easily conditioned polishing pads in some applications and toward very hard, not easily conditioned polishing pads in other applications, it becomes increasingly important that the surface texture that the pad conditioner creates can be decoupled from the polishing pad wear rate that it creates. Two opposing scenarios can be envisioned that make it difficult to create high-performance pad conditioners. In the first scenario, a very hard polishing pad may be used for high planarization and high removal rates. In such a scenario, the polishing pad may require a very aggressive pad conditioner that maintains a shallow surface texture for very high oxide removal rates using ceria slurries. In the second scenario, a very soft polishing pad may be used to reduce defects in advanced node applications. In this scenario, the polishing pad may require a less aggressive pad conditioner that maintains a higher surface texture to extend the polishing pad life of a very soft pad that needs to maintain a higher removal rate when using silica slurries.

[0014] It is known that for most conventional diamond grit and CVD coated conditioners, there is some correlation between the interplanar spacing of diamonds or abrasive features and the surface roughness produced on a given CMP pad (such that as the tip density decreases, both the pad wear rate and surface finish increase). The density of primary features in highly refined pad conditioners can be in a wide range, commercially varying from about 100 to 3300 primary features on a typical abrasive element of about 11-12 mm diameter. For most conventional pad conditioners, pad wear rates must be high to maintain a high surface roughness. This can be a cost of ownership issue when soft, easily conditioned pads are used. However, for primary feature areal densities of 0.008 / mm 2It has been found that abrasive articles with as little as 1 primary feature per element (e.g., about 11-12 mm diameter) provide low pad wear rates while maintaining high surface roughness. Moreover, such pad conditioners form less debris in the bin size range of 1-10 micrometers, reducing defects in CMP applications.

[0015] In general, in some embodiments, the present disclosure is directed to an abrasive article that is useful for conditioning a polishing pad for use in a CMP process, allowing both the wear rate of the polishing pad and the surface finish of the polishing pad to be individually controlled by the areal density of the primary polishing features and the height offset between the primary polishing features and the secondary polishing features (and any next level polishing features). In the abrasive articles of the present disclosure, the wear rate of the polishing pad is positively correlated with the number of primary polishing features, and this behavior is the opposite of the negative relationship between the pad wear rate and the number of primary polishing features of conventional highly refined pad conditioners. Moreover, in the abrasive articles of the present disclosure, the pad wear rate does not bear a relationship to the polishing pad surface roughness, and can be separately controlled by the offset height of the polishing features. For example, in the use of some embodiments of the abrasive articles of the present disclosure, only a small number of the primary polishing features engage the working surface of the polishing pad and form grooves or scratches on the working surface when removing a relatively large amount of the polishing pad material, while a large number of the secondary polishing features can contact the working surface of the polishing pad. The secondary polishing features are expected to achieve less material removal than the primary polishing features, and act primarily as a penetration stop depth for the primary polishing features. This allows the material removal and surface finish characteristics of the conditioner to be individually varied, for example, by varying the vertical / height offset of the primary polishing features to adjust the surface roughness, and by varying the number of primary polishing features to adjust the pad wear rate. Moreover, as a result of controlling the penetration depth, the sensitivity of the cutting rate and surface roughness of the polishing pad to the downward force of the pad conditioner can also be reduced. These aspects of the abrasive article of the present disclosure are in contrast to known abrasive articles with a high density of primary polishing features, where the number of primary polishing features is inversely related to both the wear rate of the polishing pad and the average surface roughness of the polishing pad. Furthermore, compared to conventional highly refined pad conditioners, the abrasive article of the present disclosure slows the decay of the pad wear rate over its lifetime, thereby enabling more consistent CMP performance.

[0016] In some embodiments, referring to FIGS. 1A-1B and 2A-2B, the present disclosure is directed to an abrasive article 10 (which may be considered a pad, i.e., a pad conditioner, for conditioning an abrasive pad for use in a CMP process) including a carrier element 15 and one or more abrasive elements 20 disposed on a major surface 15A of the carrier element 15 (the surface of the abrasive article 10 having one or more abrasive elements 20 may be considered the working surface of the abrasive article 10). As shown, the abrasive article may have multiple abrasive elements 20 (FIGS. 1A-1B) or a single abrasive element 20 (FIGS. 2A-2B). In some embodiments, the major surface 15A of the carrier element may be planar or substantially planar. In some embodiments, suitable materials for the carrier element 15 may include metals (e.g., stainless steel), ceramics, polymers (e.g., polycarbonates), cermets, silicon, and composites. The carrier element may have any shape, such as circular (as shown in FIG. 1). Alternatively, for example, the carrier element 15 may be non-circular or annular in shape.

[0017] 3A-3B, in some embodiments, the polishing element 20 of the present disclosure may include a plurality of polishing features 25 each extending from a base 30. In some embodiments, the base 30 may extend between a first major surface 30a and a second major surface 30b and may have a height (h) (or distance between the major surfaces) of 1-6 mm, 2-4 mm, or 3-3.5 mm. In some embodiments, the base 30 may have a uniform or substantially uniform height (h) throughout the polishing element 20 (i.e., the height (h) may vary by 200 micrometers or less, 100 micrometers or less, 20 micrometers or less, 10 micrometers or less, or 1 micrometer or less). In some embodiments, the polishing element 20 may have a height (h) of 30-9200 mm in terms of the projected area or footprint of the major surfaces. 2 , 30~2100mm 2 , or 30~120mm 2 As used herein, the term "projected area" of a surface refers to the area of ​​the surface viewed in a direction perpendicular to the surface, considering only the perimeter dimensions of the surface (without considering any surface contours (e.g., holes, irregularities, protrusions, etc.)).

[0018] As shown in Figure 3B, in some embodiments, each abrasive feature 25 can extend from the second major surface 30b of the base 30. As used herein, "abrasive feature" refers to a single object that (i) extends from a single feature base and terminates in a single feature peak in the form of a point, line, or facet, and (ii) has a Mohs hardness greater than 7, 8, 8.5, or 9. In some embodiments, each abrasive feature 25 can have a feature height (H), defined as the distance between the feature peak (e.g., feature peak 25b) and the feature base (e.g., feature base 25a), measured in a direction perpendicular to the second major surface 30b.

[0019] In embodiments in which the abrasive article 10 includes two or more abrasive elements 20, it should be understood that each abrasive element 20 may be the same as or different from any one or more of the other abrasive elements 20 (in terms of abrasive feature shape, size, amount, type of abrasive feature, size of abrasive feature, shape of abrasive feature, etc.).

[0020] In some embodiments, one or more abrasive elements 20 of the abrasive article 10, when viewed collectively, have a diameter of H 1avg Average feature height and H 1avg a first set of polishing features 25 (or primary polishing features) having a standard deviation of less than 10% of H 2avg (H 1avg >H 2avg ) feature average height and H 2avg a second set of features (or secondary polished features) having a standard deviation of less than 10% of H 3avg (H 1avg >H 2avg >H 3avg ) feature average height and H 3avg A third set of features (or tertiary polishing features) having a standard deviation of less than 10% of H. 1avg is H 2avgIn some embodiments, H is at least 5 micrometers, at least 10 micrometers, at least 20 micrometers, at least 50 micrometers, or at least 100 micrometers greater than H. 2avg is H 3avg 3A-3B, in terms of the primary and secondary polishing features, the polishing element 20 includes a single primary polishing feature 25' and a plurality of secondary polishing features 25".

[0021] In some embodiments, the abrasive elements 20 of the abrasive article 10 may collectively include 5-130, 5-100, or 5-50 primary abrasive features, 20-4500, 200-4500, or 2500-3500 secondary abrasive features, and 20-1500, 100-1500, or 900-1200 tertiary abrasive features. It should be understood that the primary, secondary, tertiary (etc.) abrasive features need not be uniformly distributed within the abrasive elements 20. For example, in an embodiment of an abrasive article including five primary abrasive features and five abrasive elements, the five primary abrasive features may each be located on a single abrasive element or may be distributed within the five abrasive elements in any manner.

[0022] In some embodiments, the article has primary abrasive features of 0.01 to 0.30 per cm 2 , 0.04~1.30 pieces / cm 2 , or 0.8 to 23.0 pieces / cm 2 and the secondary polishing features may be present at an areal density of 0.2 to 33.0 features / cm 2 , 0.9~150.0 pieces / cm 2 , or 17 to 2655 pieces / cm 2 or the tertiary polishing features may be present at an areal density of 0.2 to 11.0 features / cm 2 , 0.9~50.0 pieces / cm 2 , or 17 to 885 pieces / cm 2For purposes of this application, the "area density" of a set of abrasive features refers to the total number of abrasive features present per cumulative unit projected area of ​​the abrasive elements of the abrasive article.

[0023] In some embodiments, the primary polishing features of the article have an average feature height (H) of 20 to 300 micrometers, 40 to 250 micrometers, or 60 to 160 micrometers. 1avg In some embodiments, the secondary polishing features of the article may have an average feature height (H ) of 5 to 250 micrometers, 20 to 150 micrometers, or 40 to 55 micrometers. 2avg In some embodiments, the tertiary abrasive features of the article may have an average feature height (H ) of 5 to 200 micrometers, 10 to 100 micrometers, or 30 to 45 micrometers. 3avg ).

[0024] In some embodiments, the secondary features of the article (if present) may function as a "stop layer" for the primary polishing features. That is, the secondary features may function to limit the penetration of the primary features into the polishing pad being conditioned by the article, thereby limiting the aggressiveness of the polishing elements. In this regard, a H plane taken (i) in a plane parallel to the first major surface of the base and (ii) along the second set of polishing features may be used to determine the extent to which the polishing features are in contact with the polishing pad. 2avg It has been found that secondary features (if present) that satisfy the condition that the cross-sectional area of ​​the abrasive features of the second set of abrasive features at 50% or less of the abrasive features cumulatively is at least 5%, at least 10%, or at least 15% of the cumulative projected area of ​​the abrasive elements of the abrasive article provide adequate performance of the "stop layer."

[0025] In some embodiments, the polishing features can have any one or more shapes. Examples of suitable shapes of polishing features include cylinders, hemispheres, cubes, rectangular prisms, hexagonal prisms, triangular pyramids, 4-, 5-, and 6-sided pyramids, truncated pyramids, cones, truncated cones, and the like.

[0026] In some embodiments, the abrasive features (of the article or abrasive element) can have the same base size or a variety of base sizes. The abrasive features can be spaced in regular or irregular arrays on the base of the abrasive element and can be spaced the same or different distances from each other. In some embodiments, the abrasive elements have a density of abrasive features (including primary features, secondary features, tertiary features, etc.) per mm (of projected area of ​​the abrasive element). 2 1 to 1000 features per mm 2 There can be anywhere from 10 to 300 features per sample.

[0027] In some embodiments, some (up to all) of the abrasive features may be formed as precisely shaped abrasive features. As used herein, precisely shaped features refer to topographical features (e.g., protrusions, indentations, etc.) that have a molded shape that is the inverse shape of the corresponding mold cavity, and that maintain the shape after removal from the mold. In some embodiments, precisely shaped abrasive features may be formed by refinement. As used herein, "refinement" refers to a fabrication technique in which precisely shaped topographical features are prepared by casting or molding a polymer (or a polymer precursor that is later cured to form a polymer) in a production tool, such as a mold or embossing tool, which production tool has a plurality of micrometer- to millimeter-sized topographical features. Upon removal of the polymer from the production tool, a series of topographical features are present on the polymer surface. The topographical features on the polymer surface have the inverse shape of the features of the original production tool.

[0028] In some embodiments, the abrasive element may include or be formed of a ceramic carbide or ceramic oxide (such as alumina or zirconia). Suitable ceramic carbides include silicon carbide, boron carbide, zirconium carbide, titanium carbide, tungsten carbide, or combinations thereof. In some embodiments, the abrasive element may include ceramic carbide in an amount of at least 80%, at least 90%, at least 95%, or at least 99% by weight of the total weight of the abrasive element. In some embodiments, the abrasive element may include silicon carbide in an amount of at least 80%, at least 90%, at least 95%, or at least 99% by weight of the total weight of the abrasive element.

[0029] In some embodiments, the polishing element may have a porosity of less than 5%, less than 3%, or less than 1%. As used herein, porosity (expressed as a percentage) refers to the total volume of voids in the object divided by the total volume of the object. In some embodiments, the polishing element also has an average grain size of less than 20 micrometers, less than 10 micrometers, less than 5 micrometers, or less than 3 micrometers. This low porosity and small grain size can be important in achieving replicated features that are robust and durable, thus resulting in a long life and low wear rate of the polishing element.

[0030] In some embodiments, the abrasive element (including the base and abrasive features of the abrasive element) can be a monolithic abrasive element. As used herein, "monolithic" refers to a single object or part having a uniform or substantially uniform composition throughout the object or part. Monolithic elements are contrasted with composite abrasive elements in that monolithic elements have abrasive features and areas between the abrasive features that are continuous and comprise a primary abrasive material with no intervening matrix, while composite abrasive elements include abrasive particles embedded in a matrix.

[0031] In some embodiments, the abrasive element may further include one or more coatings that function to provide additional wear resistance and durability, reduce the coefficient of friction, protect against corrosion, and change surface properties. Useful coatings include, for example, chemical vapor deposited (CVD) or physical vapor deposited (PVD) diamond, doped diamond, silicon carbide, cubic boron nitride (CBN), fluorine-based coatings, non-hydrophilic or hydrophilic coatings, surface modification coatings, corrosion-resistant coatings, diamond-like carbon (DLC), diamond-like glass (DLG), tungsten carbide, silicon nitride, titanium nitride, particle coatings, polycrystalline diamond, microcrystalline diamond, nanocrystalline diamond, and the like. In some embodiments, the coating may be a composite material, such as, for example, a composite of fine diamond particles and a deposited diamond matrix. In one embodiment, these coatings are conformal, allowing precise surface features to be visible below the coating surface. The coatings can be deposited by any suitable method known in the art, including chemical or physical vapor deposition, spraying, dipping, and roll coating.

[0032] In some embodiments, the abrasive elements can be coated with a non-oxide coating. When using CVD diamond coatings, the use of silicon carbide ceramic has the added advantage of a good thermal expansion coefficient match between silicon carbide and CVD diamond films. Thus, these diamond-coated abrasives additionally have the excellent adhesion and durability of diamond films.

[0033] In some embodiments, referring again to FIG. 1A, the polishing elements 20 may be arranged on the major surface 15A of the carrier plate 15 in any desired configuration. For example, as shown in FIG. 1A, the polishing elements 20 may be arranged on the major surface 15A in a circular configuration. Alternatively, the polishing elements 20 may be arranged on the major surface 15A in a non-circular, annular, or spiral pattern. The number of polishing elements 20 on the carrier element 15 is not particularly limited. In some embodiments, the polishing elements 20 are arranged in a density range of 0.011 to 0.175 pieces / cm (based on the projected area of ​​the major surface 15A). 2 , 0.022~0.110 pieces / cm 2 , or 0.055 to 0.110 pieces / cm 2 For purposes of this application, the "area density" of abrasive elements refers to the total number of abrasive elements present per unit surface area of ​​a reference region (e.g., major surface 15A of carrier element 15).

[0034] In some embodiments, the polishing element 20 may be coupled (directly or indirectly) to the carrier element by any conventional fastening mechanism. Suitable fastening mechanisms include, for example, two-part epoxies, pressure sensitive adhesives, structural adhesives, hot melt adhesives, B-stageable adhesives, mechanical fasteners, and mechanical locking devices.

[0035] In some embodiments, a resilient element may be disposed between the polishing element 20 and the major surface 15A of the carrier element 15. In general, the resilient element may function to provide flexibility in positioning the height of one of the polishing elements relative to the height of one or more of the polishing elements. For example, during assembly of the abrasive article 10, the resilient element may elastically deform under compression and be locked in a compressed position by a fixing element, thereby fixing the height of the polishing element relative to the height of one or more of the polishing elements. In some embodiments, the resilient element may be segmented, continuous, discontinuous, or gimbaled. Examples of suitable resilient elements include, for example, mechanical spring-like devices, flexible washers, foams, polymers, or gels. The resilient element may also have a fixing feature, such as a foam with an adhesive backing.

[0036] In some embodiments, the abrasive features of the abrasive element may be aligned to a reference plane. The reference plane may be a theoretical plane passing through the highest point of a selected feature of the abrasive element or abrasive article. The feature highest point may also be referred to as the tip or apex of the feature. The selected feature is a set of working features that have a common maximum height D0.

[0037] In some embodiments, the alignment process can be used to reproducibly create a defined support area or presentation for the abrasive article. In some embodiments, the polishing elements are aligned to a planar surface (e.g., an "alignment plate") that contacts the highest points of the polishing features. The planar surface of the alignment plate preferably has a tolerance of at least about + / - 2.5 micrometers per 4 inches (10.2 cm) length, or even smaller, i.e., is planar. Resilient and fixed elements can be used in the assembly process to precisely align the polishing elements on the carrier element. In this case, the polishing elements are aligned such that there is coplanarity of the tips of the highest features. The non-coplanarity is the average absolute value of the distance of the set of tips from an ideal reference plane that passes through the set of selected tips. The non-coplanarity is expressed as a percentage of the height D0 of the selected features.

[0038] The abrasive article also has little or controlled distortion or warping of each abrasive element due to temperature mismatch with the processed or coated material, resulting in good element planarity. "Element planarity" refers to the planarity of the tips of selected features within a precisely structured abrasive element relative to a reference plane. For a single abrasive element, planarity refers to the variation in the distance of the set of feature tips relative to a reference plane. The set of tips used to calculate planarity includes the tips of all features that have a common maximum design height D0. The reference plane is defined as the plane with the best linear regression fit of the tips of all selected features with height D0. The non-planarity is the average of the absolute values ​​of the distances of the selected tips from the reference plane. Planarity can be measured by standard topology tools including carbon paper imprint testing, or laser profile measurements, confocal imaging, and confocal scanning microscopy in combination with image analysis software (e.g., MOUNTAINSMAP V5.0 image analysis software (Digital Surf, Besansson, France)). Element topology can also be characterized by skew, sharpness, etc. In some embodiments, the abrasive elements of the present disclosure can have a non-planarity of less than 20%, less than 10%, less than 5%, or less than 2% of the feature height.

[0039] In some embodiments, the abrasive article may also have precise alignment of the precisely shaped abrasive elements so that substantial coplanarity exists. For multiple abrasive elements, coplanarity refers to the variation in the distance of the set of feature tips from the multiple elements to a reference plane. This reference plane is defined as the plane with the best linear regression fit of the tips of all selected features with maximum height D0. Non-coplanarity is the average of the absolute value of the distance of the selected tips from the reference plane. If the separate abrasive elements are not aligned, non-coplanarity results. Non-coplanarity can be seen by uneven pressure distribution, for example, by carbon imprint testing. For multiple abrasive elements with uniform distribution in carbon imprint testing, the degree of coplanarity can be further quantified by standard topology tools including laser profile measurement, confocal imaging, and confocal scanning microscopy. Using image software (e.g., MOUNTAINSMAP), multiple topography maps can be combined into a composite topography map for analysis. In some embodiments, a collective group of abrasive features of all abrasive elements of an abrasive article having a common maximum feature design height D0 may have a non-coplanarity of less than 20%, less than 10%, less than 5%, or less than 2% of the feature height.

[0040] In some embodiments, the abrasive elements of the present disclosure can be formed by machining, micromachining, micro-finishing, molding, extrusion, injection molding, ceramic press molding, and the like, such that the abrasive features are made and repeatable from part to part and within a part, reflecting the ability to replicate designs. In some embodiments, a ceramic die pressing process (e.g., ceramic dry pressing) may be used.

[0041] In some embodiments, the polishing element may be made from a molded green body. In such cases, the polishing element is considered a molded polishing element. When the polishing element is molded, it is a subset of precisely structured polishing elements that are given structure by the molding process. For example, the shape may be the inversion of the mold cavity so that the shape is retained after the green body of the polishing element is removed from the mold. A variety of ceramic molding 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 some embodiments, the die pressing process is used at room temperature, followed by sintering. Typically, ceramic die pressing at around room temperature is referred to as ceramic dry pressing. Ceramic dry pressing is different from ceramic injection molding in that it is typically performed at a lower temperature, much less binder is used, die pressing is used, and materials suitable for use as binders are not necessarily limited to thermoplastics.

[0042] In some embodiments, the abrasive elements can be made without the use of carbide formers and are substantially free of oxide sintering aids. In some embodiments, the abrasive elements can contain less than about 1% of oxide sintering aids. The abrasive elements can also be substantially free of silicon, and in particular, can contain less than about 1% elemental silicon.

[0043] In some embodiments, the shaped ceramic green bodies can be sintered to achieve high density, stiffness, fracture toughness, and good feature fidelity. Green bodies, as those skilled in the art would normally refer to, are unsintered consolidated ceramic elements.

[0044] In some embodiments, the green body comprises a plurality of inorganic particles and a binder, the plurality of inorganic particles being at least about 99% by weight ceramic carbide. In one embodiment, the inorganic particles are ceramic particles and may be silicon carbide, boron carbide, zirconium carbide, tungsten carbide, or combinations thereof.

[0045] In some embodiments, the binder of the green body can be a thermoplastic binder. Examples of suitable binders include, but are not limited to, thermoplastic polymers. In one embodiment, the binder is a T g below about 25° C., particularly below about 0° C. In one embodiment, the binder is a polyacrylate binder.

[0046] In some embodiments, the green body may also include a carbon source. Suitable carbon sources include, for example, phenolic resins, cellulose compounds, sugars, graphite, carbon black, and combinations thereof. In some embodiments, the green body may include 0.5% to 10% by weight of the carbon source, particularly 2% to 7% by weight of the carbon source. The carbon compounds in the green body composition result in lower porosity after sintering. The green body may also include additional functional materials, such as release agents or lubricants. In one embodiment, the green body contains 0.5% to 10% by weight of the lubricant.

[0047] In some embodiments, the green body is an abrasive element precursor and may be fabricated by first mixing a plurality of inorganic particles, a binder, and a carbon source to form a mixture, hi one embodiment, the mixture aggregates are formed by a spray drying process.

[0048] In some embodiments, a mold having a number of precisely shaped cavities is placed into the die cavity such that the mixture fills most of the precisely shaped cavities of the mold. The mold may be formed of a metal, ceramic, cermet, composite, or polymeric material. In one embodiment, the mold is a polymeric material such as polypropylene. In another embodiment, the mold is nickel. Pressure is then applied to the mixture to force the mixture into the precisely shaped cavities to form a green body ceramic element having first and second major surfaces. Pressure may be applied at ambient or elevated temperature. Also, two or more pressing steps may be used.

[0049] In some embodiments, the mold or production tool has on its surface a predetermined array of abrasive features of the abrasive elements and a predetermined array of at least one designated shape that is the inverse of the designated shape.

[0050] In addition to the techniques described above, in some embodiments, a mold can be formed by preparing a positive master with a predetermined arrangement and specified shape of the polishing features of the polishing elements. A mold is then created with a surface topography that is the inverse of the positive master. The positive master may be created by direct machining techniques such as diamond turning as disclosed in U.S. Patent No. 5,152,917 (Pieper et al.) and U.S. Patent No. 6,076,248 (Hoopman et al.), the disclosures of which are incorporated herein by reference. These techniques are further described in U.S. Patent No. 6,021,559 (Smith), the disclosures of which are incorporated herein by reference.

[0051] For example, a mold containing a thermoplastic material can be made by replicating a metal master tool. A thermoplastic sheet material can be optionally heated along with the metal master, so that the thermoplastic material is embossed with the surface pattern exhibited by the metal master by pressing the two surfaces together. Thermoplastic materials can also be extruded or cast onto a metal master and then pressed. Other suitable methods of producing tooling and metal masters are discussed in U.S. Pat. No. 5,435,816 (Spurgeon et al.), which is incorporated herein by reference.

[0052] In some embodiments, the green ceramic element is removed from the mold and heated to sinter the inorganic particles to form the abrasive element. In some embodiments, the green ceramic element is heated during a pyrolysis process of the binder and carbon source in an oxygen-poor atmosphere at a temperature range of about 300 to about 900° C. In some embodiments, the green ceramic element is sintered in an oxygen-poor atmosphere at about 1900 to about 2300° C. to form the abrasive element. In some embodiments, the abrasive element may then be washed, after which any of the coatings described above may be optionally deposited on the abrasive element.

[0053] In some embodiments, the abrasive article of the present disclosure (which may also be referred to as a polishing pad conditioner or pad conditioner) may be used in a conventional chemical mechanical planarization (CMP) process. In such a conventional CMP process, a variety of materials may be polished or planarized, 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, silicon dioxide, silicon oxide, hafnium oxide, low dielectric constant materials, and combinations thereof. In some embodiments, the polishing pad (or at least the working surface of the polishing pad) conditioned by the abrasive article of the present disclosure may include a thermoplastic material, a thermoplastic elastomer (TPE), such as a TPE based on a block copolymer, or a thermoset, such as an elastomer, and combinations thereof. In some embodiments, the polishing pad (or at least the working surface of the polishing pad) may comprise or be formed of polyurethane, polyamide, polybutadiene, or polyolefin, as are commonly used in commercially available polishing pads for substrate planarization. In some embodiments, the hardness of the working surface of the polishing pad may be greater than about 20 Shore D, greater than about 30 Shore D, or greater than about 40 Shore D; less than about 90 Shore D, less than about 80 Shore D, or less than about 70 Shore D; 20-90 Shore D, 30-80 Shore D, or 40-70 Shore D. In some embodiments, the hardness of the working surface of the polishing pad may be greater than about 20 Shore A, greater than about 30 Shore A, or greater than about 40 Shore A; less than about 95 Shore A, less than about 80 Shore A, or less than about 70 Shore A; or 20-95 Shore A, 30-80 Shore A, or 40-70 Shore A.

[0054] In some embodiments, the pad conditioner may be implemented in a conventional CMP tool and configured to operate under conventional operating conditions. In some embodiments, the CMP process may sweep back and forth across the polishing pad at a rate of about 1 to about 25 sweeps per minute utilizing a conventional sweep profile, such as a sinusoidal or linear sweep, at a rotational speed ranging from about 20 RPM to about 150 RPM, and at an applied load ranging from about 1 pound to about 90 pounds. LIST OF EMBODIMENTS 1. An abrasive article comprising: a plurality of abrasive features disposed on one or more abrasive elements, each of the one or more abrasive elements including a base having a first major surface with a plurality of abrasive features extending from the first major surface; The first set of the plurality of abrasive features has (i) an average height H 1avg (ii) H 1avg and (iii) comprising 5 to 130 abrasive features. 2. A second set of the plurality of abrasive features has (i) an average height H 2avg and (ii) H 2avg with a standard deviation of less than 10% of H 1avg But, H 2avg 2. The abrasive article of embodiment 1, wherein the abrasive surface area is at least 5 micrometers larger than 3. The abrasive article of embodiment 2, wherein the second set of the plurality of abrasive features comprises at least 100 abrasive features. 4. (i) a plane taken parallel to the first major surface of the base and (ii) along the second set of polishing features; 2avg 4. The abrasive article of claim 2 or 3, wherein the cross-sectional area of ​​each of the features of the second set of abrasive features at 50% or less of the abrasive elements is cumulatively at least 5% of the cumulative projected area of ​​the one or more abrasive elements. 5. An abrasive article according to any one of the preceding embodiments, wherein the features of the first set of abrasive features and the bases of their corresponding abrasive elements are monolithic as a collection. 6. The abrasive article of any one of embodiments 1-5, wherein the first set of abrasive features are precisely shaped features. 7. The areal density of the first set of abrasive features is between 0.01 and 0.30 features / cm 2 The abrasive article according to any one of embodiments 1 to 6, wherein 8. The areal density of the second set of abrasive features is between 0.2 and 33.0 features / cm 2 The abrasive article according to any one of embodiments 2 to 7, wherein 9. The abrasive article of any one of the preceding claims, wherein the abrasive elements comprise a ceramic carbonizer. 10. The abrasive article of embodiment 9, wherein the carbide ceramic is silicon carbide, boron carbide, zirconium carbide, titanium carbide, tungsten carbide, or a combination thereof. 11. An abrasive article according to any one of the preceding embodiments, wherein the abrasive element is at least 99% by weight of the total weight of the base and abrasive features is silicon carbide. 12. The abrasive article of any one of the preceding embodiments, wherein the porosity of the abrasive elements is less than about 3%. 13. The abrasive article of any one of the preceding claims, further comprising a chemical vapor deposition or physical vapor deposition coating disposed on the abrasive features. 14. An abrasive article described in any one of embodiments 1 to 13, further comprising a carrier plate having a first major surface, and one or more abrasive elements bonded to the first major surface of the carrier plate. 15. A method for conditioning a polishing pad, comprising: performing a CMP operation using a polishing pad; contacting a working surface of an abrasive pad with a working surface of the abrasive article of any one of embodiments 1-14. Working Example

[0055] The present disclosure is described in more detail in the following examples, which are for purposes of illustration only, since numerous modifications and variations within the scope of the present disclosure will become apparent to those of ordinary skill in the art. Unless otherwise noted, all parts, percentages, and ratios reported in the following examples are by weight. Test Method Feature Height Measurement Test Method

[0056] The feature heights of the precisely shaped abrasive features on each abrasive element were measured using a Brunker Contour GT 3D optical profiler in combination with MOUNTAINSMAP Universal V6.1 image analysis software (Digital Surf, Besansson, France). The magnification (5X x 0.55X) and scan speed settings (5X) of the optical profiler were adjusted to provide sufficient resolution to accurately locate the tip of the features and accurately measure their respective heights. A group of features were selected for the abrasive elements that all had the same feature maximum design height D0, and their peak heights were measured relative to the saddle point of their local course line, respectively. The peak heights, course lines, and saddle points are defined by the watershed algorithm of MOUNTAINSMAP Universal V6.1. Testing method for CMP pad wear rate and pad surface roughness using a benchtop tribometer

[0057] Pad wear rate and pad surface roughness measurements were performed on pads conditioned with the abrasive articles (described below) using a CP4 Micro Tribometer benchtop friction polishing tool available from Center for Tribology, Inc. (now available through Brunker Corporation) in conjunction with the 3D optical profiler and software analysis tools described above in the Feature Height Measurement Test Method. Two different CMP pads were used to amplify either the pad wear rate or the pad surface finish. All of the abrasive article examples and comparative examples were performed on a relatively hard, but easily conditioned pad to amplify the pad wear rate results. The pad was available from JSR Micro, Inc. (Sunnyvale, CA) under the trade name 9006FPJ (part number CMP9006FPJ). A second industry standard hard pad was used to collect the surface roughness values ​​for Examples 1, 2, 4, 6, and 8, and Comparative Examples A-G. These pads were available from The Dow Chemical Company (Midland, MI) under the trade name Dow IC1010 (material number 10261135). As received pads were die cut to a diameter of 9 inches (23 cm) and mounted on the platen of the CP4. For example, an abrasive article of an embodiment or comparative example of the present disclosure was mounted on the spindle of the CP4 using a universal 3-screw mounting device for the pad conditioner. For the duration of the test, the conditioner spindle rotated at a speed of 29 rpm and the pad spindle rotated at a speed of 61 rpm while the spindle moved downwards (the up and down motion is considered to be in the z-direction) so that the abrasive article was in contact with the pad and maintained with a downward force of 6 pounds (6.7 kg). The conditioner spindle swept back from 55 mm to 69 mm at a rate of 10 cycles per minute. A typical test lasted for 30 minutes with the first 5 minutes considered as the break-in period. The tribometer tracks the vertical position of the mounted abrasive article as a function of time. The height change of the abrasive article over the test time gives the pad wear rate. The slope of the best fit line of z-height position over time, excluding the first 5 minutes of the test (the break-in period), was defined as the individual pad wear rate.Each abrasive article was measured at least three times, but not more than six times, and the pad wear rate was reported as the average of the individual test results. After the pad wear rate test was completed, the 9 inch (23 cm) diameter platen was removed from the tribometer. 3D optical profiler scans were performed over a 2 mm x 4 mm area of ​​the conditioned pad at 0.5 inches (1.3 cm), 2.25 inches (5.7 cm), and 3.0 inches (7.6 cm) from the pad center. The average surface roughness (Ra) at these different pad locations was obtained using MOUNTAINSMAP software, and the average roughness value of the three locations was reported as the surface roughness. Test method for pad wear rate and pad surface roughness of CMP tools

[0058] Measurements were performed on conditioned pads on an Applied Materials 200 mm REFLEXION polishing tool. Conditioning cycles were performed with a conditioner speed of 87 rpm and a pad speed of 93 rpm with a down force of 6 lbs (2.7 kg). The conditioner arm sweep recipe had a start position of 1.00 in. (2.5 cm) and an end position of 12.75 in. (32.4 cm). The sweep was divided into 13 zones with relative dwell times of 1.20, 1.10, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.20, and 1.55, respectively. The cycle time was 13 sweeps per minute. Pad wear rates were determined by measuring the depth of each groove on the initial surface of the pad from 3 in. (7.6 cm) to 14 in. (35.6 cm) from the center of the pad using a laser profilometer. The initial groove depth of the pad was defined as the average of all groove depths located between 3 inches (7.6 cm) and 14 inches (35.6 cm). After the pad was abraded for 1 hour, the initial average groove depth of the pad was compared to the average groove depth of the pad over the same length. The difference in average groove depth divided by the test time was reported as the pad wear rate. To determine the pad surface roughness, a contact profilometer was used to measure Ra at distances of 2 inches (5.1 cm), 4 inches (10.2 cm), 6 inches (15.2 cm), 8 inches (20.3 cm), 10 inches (25.4 cm), 12 inches (30.5 cm), and 14 inches (35.6 cm) from the center of the freshly conditioned pad. Ra was reported as the average of these seven locations. Examples and Comparative Examples (CE)

[0059] Twenty-four designs of abrasive elements were prepared as described in Example 10 of U.S. Pat. No. 9,956,664 (which differed only in the geometry of the abrasive features as described in Table 1). U.S. Pat. No. 9,956,664 is incorporated herein by reference in its entirety. Each abrasive element had at least one precisely shaped feature with a primary feature height that was higher than and offset relative to any secondary level features or flat base areas between features. Five abrasive elements were prepared for each example and comparative example and assembled into an abrasive article. An assembly process was developed so that the highest precisely shaped features on each element, all with the same feature design height, were planar. A planar sapphire surface was used as the alignment plate. The segments were placed (facing down) on the alignment plate such that the major surfaces with the precisely shaped features were in direct contact with the alignment plate with their second flat major surfaces facing up. The abrasive elements were arranged in a circular pattern such that their center points were spaced about 72° apart along the circumference of a circle with a radius of about 1.75 inches (44.5 mm). A fastening element was then applied to the exposed surfaces of the abrasive elements in the central region. The fastening element was an epoxy adhesive available from 3M Company, St. Paul, Minnesota, under the trade designation 3M SCOTCH-WELD EPOXY ADHESIVE DP420. A circular stainless steel carrier having a diameter of 4.25 inches (108 mm) and a thickness of 0.22 inches (5.64 mm) was then placed face down on top of the fastening elements (the backside of the carrier was machined so that it could be attached to the carrier arm of a REFLEXION polisher). A load of 10 pounds (4.54 kg) was applied evenly across the exposed surface of the carrier, and the adhesive was allowed to cure at room temperature for about 4 hours. In some cases, when there were only one or two primary polishing features on the polishing element, specially positioned small holes were placed in the sapphire alignment plate to allow the secondary polishing features to contact the sapphire surface while keeping the primary polishing features out of contact with the sapphire surface in order to maintain the planarity of the polishing surfaces of the different elements.The offset height between the primary and secondary abrasive features is defined as the height difference between the primary feature and the secondary feature, or, if no secondary feature is present, the height difference between the primary feature and the base region. The aspect ratio is defined as the feature height divided by its base width. The truncated depth of the primary feature is defined by the depth at which the theoretical apex would be formed if the sides of the pyramid were converged to a point. The primary feature height was measured as described in the Feature Height Measurement Test Method. The number of primary features is the number of primary features found in a fully constructed abrasive article (including all five elements). The feature areal density is defined as the number of primary features per element divided by the surface area of ​​the abrasive article. The surface of the abrasive article is defined as the greater of the entire working surface of one or more abrasive elements of the abrasive article or the surface area of ​​the first major surface of the carrier plate to which the abrasive elements may be attached. Comparative Examples 1, 2, and 4-7 are all pyramids with hexagonal bases. Comparative Examples 3, 8, 9 and Examples 1-15 are all pyramids with rectangular or square bases. The pyramids were arranged in a rectangular grid pattern. See, for example, Figures 3A and 3B. [Table 1]

[0060] Using the CMP Pad Wear Rate and Pad Surface Roughness by Benchtop Tribometer test method, pad wear rates and pad surface roughness were determined for Examples 1-15 and Comparative Examples 1-9 in Table 2. The results showed that the pad wear rate of an abrasive article increases with its surface roughness as the number or areal density of abrasive features on the element decreases (see FIG. 4). This is a well-known and documented relationship in the abrasives industry. However, as the number and areal density of tips per abrasive article decreases to the ultra-low areal density region (26 features / element or 0.24 features / mm 2 At 0.25 mm (<0.05 mm), this relationship was reversed and the pad wear rate began to decrease, and at this point the surface roughness was no longer correlated to the feature count and areal density of the primary features, but rather to the offset height between the primary and secondary features. [Table 2] CMP tool testing using examples

[0061] Using the CMP Tool Pad Wear Rate and Pad Surface Roughness test method, the pad wear rate and pad surface roughness for an industry standard hard pad (Dow IC1010) were determined for the Examples and Comparative Examples shown in Table 3. The results are shown in Table 3. The data gives similar results to the benchtop tribometer data. [Table 3]

Claims

1. 1. An abrasive article comprising: a plurality of abrasive features disposed on one or more abrasive elements, each of the one or more abrasive elements including a base having a first major surface from which the plurality of abrasive features extend; The first set of the plurality of abrasive features has (i) an average height H １ａｖｇ (ii) H １ａｖｇ (iii) comprises 5 to 130 abrasive features; and (iv) has an areal density of 0.01 to 0.30 features / cm 2 .

2. The second set of the plurality of abrasive features has (i) an average height H ２ａｖｇ and (ii) H ２ａｖｇ has a standard deviation of less than 10% of H １ａｖｇ But, H ２ａｖｇ 2. The abrasive article of claim 1, wherein the abrasive layer is at least 5 micrometers larger than

3. The abrasive article of claim 2 , wherein the second set of the plurality of abrasive features comprises at least 100 abrasive features.

4. (i) a plane taken parallel to the first major surface of the base, and (ii) along the second set of abrasive features; ２ａｖｇ 3. The abrasive article of claim 2, wherein the cross-sectional area of ​​each of the features of the second set of abrasive features at 50% or less of the abrasive features is cumulatively at least 5% of the cumulative projected area of ​​the one or more abrasive elements.

5. 10. The abrasive article of claim 1, wherein the features of the first set of abrasive features and their corresponding abrasive element bases are collectively monolithic.

6. The abrasive article of claim 1 , wherein the first set of abrasive features are precisely shaped features.

7. The abrasive article of claim 1 , wherein the abrasive elements comprise a ceramic carbide.

8. 10. The abrasive article of claim 1, wherein the abrasive elements have a porosity of less than about 3%.

9. 10. The abrasive article of claim 1, further comprising a chemical vapor deposition or physical vapor deposition coating disposed on the abrasive features.

10. 1. A method for conditioning a polishing pad, comprising: performing a CMP operation using a polishing pad; and contacting the working surface of the polishing pad with the working surface of the abrasive article of claim 1.

Images