JP2013526777A - Fixed polishing pad containing surfactant for chemical mechanical planarization - Google Patents

Abstract

A fixed abrasive pad (100) is provided in the form of a structured abrasive article having a structured abrasive layer (120) disposed on a backing (110). The structured abrasive layer (120) includes a polymer binder, abrasive particles dispersed in the binder, and a polyether type nonionic surfactant dispersed in the binder. The abrasive particles have an average particle size of less than about 200 nm and the surfactant is present in the binder in an amount of 0.75 to 2.2 weight percent, based on the total weight of the structured abrasive layer. A method of polishing a workpiece using the provided fixed polishing pad is also provided.
[Selection] Figure 1

Description

  The present invention relates generally to abrasive articles, methods for making the same, and uses in wafer planarization.

  Abrasive articles are often used in microfinishing applications such as semiconductor wafer polishing, microelectromechanical (MEMS) device fabrication, hard disk drive substrate finishing, optical fiber and connector polishing. For example, semiconductor wafers are typically subjected to a number of processing steps during the manufacture of integrated circuits, including deposition of metal and dielectric layers, layer patterning, and etching. In each processing step, it may be necessary or desirable to modify or improve the exposed surface of the wafer in preparation for subsequent fabrication or manufacturing steps. Surface modification processes are often used to modify deposited conductors (eg, metals, semiconductors and / or dielectric materials). A surface modification process is typically used to create a flat externally exposed surface on a wafer having areas where the conductor material, dielectric material or combination structure is exposed.

  One way to modify or improve the exposed surface of a structured wafer includes treating the wafer surface with a fixed abrasive article, and in use, the fixed abrasive article typically has a layer of material on the wafer. In an operation suitable for modifying the surface, often in contact with the semiconductor wafer surface in the presence of a working fluid, resulting in a flat and uniform wafer surface. The wafer surface can be chemically modified by applying a working fluid, or by applying a working fluid so that the material can be easily removed from the surface of the wafer under the action of the abrasive article. You can also.

  Fixed abrasive articles generally have an abrasive layer of abrasive particles bonded by a binder and fixed to a backing. In certain fixed abrasive articles, the abrasive layer is composed of discrete raised structure type elements (eg, columnar, bowl-shaped, cone-shaped, or truncated cone-shaped) called molded abrasive composites. . This type of fixed abrasive article is widely known in the art by the term "non-flat fixed abrasive article" or "structured abrasive article" (hereinafter the latter term will be used). The abrasive article includes abrasive particles and at least one polyether-type nonionic surfactant in a crosslinked polymer binder as disclosed in US patent application Ser. No. 12 / 560,797 (Woo et al.). It can be dispersed and contained.

  Various detection methods are generally implemented for the purpose of evaluating the progress during the planarization process. Of these, optical detection methods (for example, laser interferometry) are most widely used. In such techniques, the laser is typically directed through a platen and subpad window in contact with the structured abrasive article. A hole portion or a transparent (not covered with an abrasive layer) portion of the structured abrasive article is aligned with the beam.

  Chemical mechanical planarization (CMP) processes can result in non-uniform polished wafers. There is a need for a fixed abrasive article that provides a very uniform wafer and has a high polishing rate. There is a need for fixed abrasive articles useful for making electronic components with very small nodes. For example, dynamic random access memory (DRAM) and flash memory devices may have 32 nm and even 28 nm nodes. There is a need for a fixed abrasive article that can rapidly polish a semiconductor wafer having small nodes without causing defects that can short circuit between channels.

  It has been found that the use of very small abrasive particles and surfactants in a structured adhesive layer can improve wafer uniformity and increase the wafer polishing rate. . In one aspect, a structured abrasive article is provided, comprising a backing having first and second opposing major surfaces, and a structured abrasive layer disposed and secured to the first major surface. The abrasive layer includes a polymer binder, abrasive particles dispersed in the binder, and a polyether type nonionic surfactant dispersed in the binder, the average particle size of the abrasive particles being less than about 200 nm The polyether type nonionic surfactant does not covalently bond to the crosslinked polymer binder, and the polyether type nonionic surfactant is 0.75 to 2 based on the total weight of the structured adhesive layer. Present in an amount of 2 weight percent. Shaped abrasive composites can be precisely molded. The binder can include an acrylic polymer. Surfactants can include polyethylene oxide or polypropylene oxide segments. The backing can be a polyurethane elastomer film or a polymer foam.

  In another aspect, in the presence of an aqueous fluid, at least a portion of the structured abrasive article and the surface of the workpiece are in frictional contact, and at least one of the workpiece or the structured abrasive layer is moved relative to the other. Polishing a workpiece comprising at least a portion of a surface of the workpiece, wherein the structured abrasive article comprises a backing having first and second opposing major surfaces; and A structured abrasive layer disposed on and fixed to the first major surface, the structured abrasive layer comprising a polymer binder, abrasive particles dispersed in the binder, and a poly dispersed in the binder. An ether type nonionic surfactant is included, the average particle size of the abrasive particles is less than about 200 nm, the polyether type nonionic surfactant does not covalently bond to the crosslinked polymer binder, and the polyether type nonionic Surfactant is Based on the total weight of Zoka adhesive layer is present in an amount of from 0.75 to 2.2 weight percent. The aqueous fluid can include tap water.

As used herein,
The term “abrasive particle” refers to any particle having a hardness equal to or greater than that of ceria.
The terms “fixed polishing pad” and “structured abrasive article” are used interchangeably.
The term “at least translucent” means translucent or transparent.
The term “carboxylic acid (meth) acrylate” means a compound having a (meth) acrylate group covalently bonded to a carboxyl (—CO ₂ H) group or a carboxylate (—CO ₂ —) group.
The term “visible light” refers to light having a wavelength in the range of 400 nanometers to 700 nanometers (inclusive).
The term “(meth) acryl” includes acrylic and / or methacrylic.
The term “light transmittance” means the rate at which incident light is transmitted through an object.
The term “poly (meth) acrylate” means a compound having at least two (meth) acrylate groups.
The term “transparent” means that visible light can be transmitted so that an object or image can be seen as if substantially no intervening material is present.
The terms “cerium oxide” and “ceria” refer to Ce (IV) O ₂ .

  The above summary is not intended to describe each embodiment disclosed for each implementation of the invention. Illustrative embodiments are illustrated in more detail in the “Brief Description of the Drawings” and the subsequent “Modes for Carrying Out the Invention”.

1 is a perspective view of an exemplary structured abrasive article according to one embodiment of the present disclosure. FIG. 1 is a schematic side view of an exemplary wafer surface conditioning method in accordance with the present disclosure. FIG. 5 is a graph of oxide removal rate as a function of wafer cross-section diameter using the provided articles and methods.

  In the following description, reference is made to the accompanying series of drawings, which form a part hereof, and in which are shown by way of illustration several specific embodiments. It should be understood that other embodiments are possible and may be practiced without departing from the scope or spirit of the invention. The following detailed description is, therefore, not to be construed in a limiting sense.

  Unless otherwise indicated, numbers representing the size, quantity, and physical properties of features used in the specification and claims are understood to be modified by the term “about” in all examples. Should be. Accordingly, unless otherwise stated, the numerical parameters set forth in the foregoing specification and appended claims will depend on the desired characteristics sought by those skilled in the art using the teachings disclosed herein. It is an approximate value that can change. Citation of a numerical range using an endpoint is all within that range (eg 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Includes numbers and any range within that range.

  Referring to FIG. 1, the structured abrasive article 100 comprises at least a translucent film backing 110. The abrasive layer 120 is disposed on at least a translucent film backing 110 and includes a plurality of shaped abrasive composites 130. The shaped abrasive composite 130 contains abrasive particles (not shown) dispersed in a binder (not shown). The abrasive particles consist essentially of ceria particles having an average primary particle size of less than 100 nanometers. The binder includes a polyether acid and a reaction product of components including carboxylic acid (meth) acrylate and poly (meth) acrylate, and the abrasive particles are in an amount of at least 70% by weight, based on the total weight of the polishing layer. Exists.

  The translucent film backing may be flexible, rigid, or properties in between. A variety of backing materials are suitable for this purpose, including both flexible backings and stiffer backings. Useful translucent film backings include backing films selected from polymer films, processed ones, and combinations thereof. Typical translucent backing films are made from polyester (eg, polyethylene terephthalate or polycaprolactone), copolyester, polycarbonate, polyimide, polyamide, polypropylene, polyurethane, polyethylene, cellulosic polymers, and blends and combinations thereof. Film. In some embodiments, the backing includes a urethane elastomer or foam.

  The thickness of the translucent film backing is typically about 20 to about 1000 micrometers, more typically about 50 micrometers to about 500 micrometers, more typically about 60 micrometers. In the range of ~ 200 micrometers. At least one surface of the backing may be coated with an abrasive layer. In general, the backing is of a substantially uniform thickness. If the thickness of the backing is not sufficiently uniform, the wafer polishing uniformity variation may become larger during wafer planarization.

  The polishing layer includes a plurality of molded abrasive composites. As used herein, the term “shaped abrasive composite” refers to a plurality of shaped bodies comprising abrasive particles dispersed in a binder, the shaped bodies collectively being non-planar three-dimensional. A polishing layer is formed. In some embodiments, the shaped abrasive composite is “precisely shaped”. The term “precisely shaped abrasive composite” refers to an abrasive composite whose shaped shape is a substantially inverted shape of the mold cavity used to create it. Typically, a precisely shaped abrasive composite is substantially free of abrasive particles protruding from the exposed surface of the abrasive composite before the structured abrasive article is used.

  The provided structured abrasive article may contain a high weight of shaped abrasive particles in the abrasive layer. For example, the shaped abrasive composite may comprise at least 70%, at least 75%, 80%, or even 90% by weight or more of the polishing layer. Typically, the amount of cutting increases as the proportion (wt%) of abrasive particles in the shaped abrasive composite increases.

  Abrasive particles can include ceria (ie, cerium oxide) particles having an average particle size of less than 250 nanometers, less than 150 nanometers, less than 100 nanometers, and even less than 50 nanometers, based on volume. The abrasive particles can be substantially composed of ceria particles. The phrase “substantially” as used herein refers to an amount of other (ie non-ceria) polishing that significantly affects the polishing characteristics of the structured abrasive article when used in wafer planarization of silicon-containing wafers. The particles are intended to be excluded. It will be appreciated that the ceria particles may comprise agglomerates and / or aggregates of smaller primary ceria particles. For example, ceria particles (whether present as primary particles, agglomerates, particle clusters, or combinations thereof) are from 1, 5, 10, 20, 30, or 40 nanometers to 50, on a volume basis, It may have an average particle size in the range of 60, 70, 80, 90, 95 nanometers or more.

  The ceria particles may be supplied, for example, in the form of a powder, dispersion, or sol, and are typically supplied as a dispersion or sol. Methods and sources for obtaining ceria sols having an average particle size of less than 250 nanometers are well known in the art. Suitable ceria dispersions and sols for use in the present disclosure include, for example, Evonik Degussa Corp. (Parsippany, NJ), Rhodia, Inc. (Cranberry, NJ), Ferro Corporation (Independence, OH), and Ceria sols and dispersions commercially available from suppliers such as Umicore SA (Brussels, Belgium).

  The abrasive particles can be uniformly or non-uniformly dispersed in the polymer binder. The term “dispersed” refers to the distribution of abrasive particles throughout the polymeric binder. Dispersing the ceria particles substantially uniformly in the binder typically improves the performance of the structured abrasive article. Accordingly, it is typically useful to treat ceria particles with carboxylic acid (meth) acrylates to promote dispersion and / or suppress agglomeration and enhance subsequent binding to the binder. Typical carboxylic acid (meth) acrylates include (meth) acrylic acid, maleic acid monoalkyl ester, fumaric acid, fumaric acid monoalkyl ester, maleic acid, itaconic acid, isocrotonic acid, crotonic acid, citraconic acid, And β-carboxyethyl (meth) acrylate.

  In one exemplary method of treating ceria particles with carboxylic acid (meth) acrylate, a dispersion (eg, sol) of ceria particles in an aqueous medium (eg, water) is converted to polyether acid and carboxylic acid (meth) acrylate. Combined with a water miscible organic solvent (both sufficient to treat the surface and stabilize the ceria particles), as well as a boiling point higher than water. Typically, the ratio of polyether acid to carboxylic acid (meth) acrylate is in the range of about 3: 5 to 5: 3, although other ratios may be used. Examples of useful solvents include 1-methoxy-2-propanol, dimethylformamide, and diglyme. These are combined, evaporated under reduced pressure, and water is substantially removed to obtain a ceria dispersion. In this dispersion, the ceria particles are associated with carboxylic acid (meth) acrylate molecules, resulting in agglomeration. It is stable against conversion. The resulting ceria dispersion is typically easy with poly (meth) acrylate and any mono (meth) acrylate monomer, and any additional carboxylic acid (meth) acrylate that can be included in the binder precursor. Can be combined.

Carboxylic acid (meth) acrylates typically have the function of promoting adhesion of ceria particles to the binder, while polyether acids are primarily used in binders (or their precursor components) and / or solvents. Included to increase the dispersion stability of the ceria particles therein. As used herein, the term “polyether acid” refers to a compound having a polyether segment covalently bonded to an acidic group or salt thereof. Exemplary polyether segments include polyethylene glycol segments, polyethylene glycol segments, and mixed poly (ethylene glycol / propylene glycol) segments. Representative acidic _{group, -CO 2 H, -PO 2 H} , -PO 3 H, -SO 3 H, and salts thereof. In certain embodiments, the polyether acid has up to 12 carbon atoms and is represented by the following formula:

_{^{R 1 - (R 2 -O)}} n -X-A
Wherein R ¹ is H, an alkyl group having 1 to 6 carbon atoms (eg, methyl, ethyl, or propyl), or an alkoxy group having 1 to 6 carbon atoms (eg, methoxy, ethoxy, or Each R ² independently represents a divalent alkylene group having 1 to 6 carbon atoms (eg, ethylene, propylene, or butylene), and n is a positive integer (eg, 1 2 or 3), X represents a divalent organic linking group or a covalent bond, and A represents an acidic group (for example, the above description). Representative examples of such polyether acids include ethyl 2 ′-(2 ″ -methoxyethoxy) succinate (monoester), methoxyethoxyethoxyacetic acid, and methoxyethoxyacetic acid. The binder is a carboxylic acid (meth). The reaction product of an element comprising acrylate and poly (meth) acrylate may further be included, as described above, at least a portion of the carboxylic acid (meth) acrylate is typically combined with abrasive particles and then obtained. This dispersion is combined with the remaining binder components, but this is not essential.

  The polyether type nonionic surfactant is dispersed in the binder. Typically, there are no covalent bonds between the surfactant and the binder. The binder can be cross-linked to contain a surfactant and to help regulate its release, as further described. The amount of the polyether type nonionic surfactant present in the shaped abrasive composite is 0.75 to 2.2% by weight, 1.0 to 2.2% by weight based on the total weight of the shaped abrasive composite. %, 1.3-2.2% by weight, typically in the range of 1.5-2.0% by weight. As used herein, the term “polyether-type nonionic surfactant” typically refers to a poly that forms at least a portion of the surfactant backbone (but this property is not essential). Refers to one or more nonionic (ie, having no persistent charge) surfactants having an ether segment. As is the case with common surfactants, polyether-type nonionic surfactants should not be covalently bonded to cross-linked polymer-type binders. In order to facilitate dissolution in aqueous fluids, polyether type nonionic surfactants will typically have a molecular weight in the range of 300-1200 grams per mole, although higher molecular weights and Lower molecular weight polyether type nonionic surfactants may be used.

  Examples of polyether type nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl-phenyl ether, polyoxyethylene acyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene lauryl Ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol laurate, polyethylene glycol stearate, polyethylene glycol distearate, Polyethylene glycol oleate, oxyethylene-oxypropylene block copolymer, polyoxy Chile Nso sorbitan monolaurate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan oleate, and polyoxyethylene lauryl amides.

  Further, useful polyether type nonionic surfactants include, for example, condensation products of higher aliphatic alcohols and about 3 equivalents to about 100 equivalents of ethylene oxide (for example, trade name TERGITOL 15-S from Dow Chemical Co.). And those sold under the trade name BRIJ from ICI Americas (Bridgewater, NJ), such as BRIJ 58, BRIJ 76, and BRIJ 97). . Surfactant BRIJ 97 is polyoxyethylene (10) oleyl ether, surfactant BRIJ 58 is polyoxyethylene (20) cetyl ether, and surfactant BRIJ 76 is polyoxyethylene (10) stearyl. Ether.

  Further, useful polyether type nonionic surfactants include, for example, a polyethylene oxide condensation product of alkylphenol and about 3 equivalents to about 100 equivalents of ethylene oxide (for example, Rhodia (Cranbury, NJ) under the trade name IGEPAL CO and And those sold as IGEPAL CA). IGEPAL CO surfactant includes nonylphenoxy poly (ethyleneoxy) ethanol. IGEPAL CA surfactant includes octylphenoxy poly (ethyleneoxy) ethanol. Examples of useful polyether type nonionic surfactants include block copolymers of ethylene oxide and propylene oxide or butylene oxide (for example, BASF Corp (Mount Olive, NJ) to PLURONIC (for example, PLURONIC L10)). And those sold as TETRONIC). PLURONIC surfactants may include propylene oxide polymers, ethylene oxide polymers, and ethylene oxide-propylene oxide block copolymers. TETRONIC surfactants include ethylene oxide-propylene oxide block copolymers.

In some embodiments, polyether-type nonionic surfactants include, for example, 20 ethylene oxide units per molecule (eg, sold as TWEEN 60) or 20 ethylene oxide units per molecule (eg, TWEEN). By polyoxyethylene sorbitan fatty acid esters (eg, polyoxyethylene sorbitan monooleate), and polyoxyethylene stearate (eg, Uniqema (New Castle, DE)), which can have various degrees of ethoxylation, such as sold as 80) And those sold under the trade names TWEEN and MYRJ). Surfactant TWEEN includes poly (ethylene oxide) C ₁₂ -C ₁₈ sorbitan monoester. Surfactant MYRJ includes poly (ethylene oxide) stearate.

  In some embodiments, the polyether-type nonionic surfactant is the only surfactant present in the shaped abrasive composite or in the aqueous fluid during polishing. In some cases, Dow Chemical Co. It may be desirable to add a smaller amount of anionic surfactant such as anionic phosphate polyether ester available as TRITON H55.

  The abrasive layer includes abrasive particles dispersed in a binder. Suitable binder precursors are typically uncured or non-crosslinked and flowable at or near ambient conditions. The binder precursor is then typically exposed to conditions (typically an energy source) that at least partially cure or crosslink (ie, free radical polymerization) the binder precursor to disperse. Converted to a binder capable of holding the polished particles. Typical energy sources include electron beams, ultraviolet rays, visible rays, infrared rays, gamma rays, heat, and combinations thereof.

  Useful poly (meth) acrylates include monomers and / or oligomers having at least two (meth) acrylate groups, such as tri (meth) acrylate and tetra (methacrylate). Exemplary poly (methacrylates) include: di (meth) acrylates such as 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1,6-hexanediol mono (meth) acrylate mono (meth) acrylate, ethylene glycol di (meth) acrylate, alkoxylated aliphatic di (meth) acrylate, alkoxylated cyclohexanedimethanol Di (meth) acrylate, alkoxylated hexanediol di (meth) acrylate, alkoxylated neopentyl glycol di (meth) acrylate, caprolactone modified neopentyl glycol hydroxypivalic acid di (meth) acrylate, caprolactone Decorated neopentyl glycol hydroxypivalic acid di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, ethoxylated (10) bisphenol A di (meth) Acrylate, ethoxylated (3) bisphenol A di (meth) acrylate, ethoxylated (30) bisphenol A di (meth) acrylate, ethoxylated (4) bisphenol A di (meth) acrylate, hydroxypivalaldehyde modified trimethylolpropane di (Meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol (200) di (meth) acrylate, polyethylene glycol (400) di (meth) a Relate, polyethylene glycol (600) di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, triethylene glycol di ( Meth) acrylate, tripropylene glycol di (meth) acrylate; tri (meth) (meth) acrylate such as glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated tri (meth) acrylate (eg ethoxylated) (3) Trimethylolpropane tri (meth) acrylate, ethoxylated (6) trimethylolpropane tri (meth) acrylate, ethoxylated (9) trimethylolpropane tri (Meth) acrylate, ethoxylated (20) trimethylolpropane tri (meth) acrylate), pentaerythritol tri (meth) acrylate, propoxylated tri (meth) acrylate (eg propoxylated (3) glyceryl tri (meth) acrylate) , Propoxylated (5.5) glyceryl tri (meth) acrylate, propoxylated (3) trimethylolpropane tri (meth) acrylate, propoxylated (6) trimethylolpropane tri (meth) acrylate), trimethylolpropane Tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; and high functionality (meth) acryl-containing compounds such as ditrimethylolpropane tetra (meth) acrylate, dipentaeth Thritol penta (meth) acrylate, ethoxylated (4) pentaerythritol tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate; oligomer (meth) acrylic compound such as polyester ( (Meth) acrylates, epoxy (meth) acrylates; and combinations thereof. Such compounds are described, for example, by Sartomer Co. (Exton, PA); UCB Chemicals Corporation (Smyrna, GA); and Aldrich Chemical Company (Milwaukee, Wis.).

  The binder precursor may comprise an effective amount, for example, 0.1, 1, or 3% by weight up to 5, 7, or even 10% by weight, or more of at least one photoinitiator. . Useful photoinitiators include those known to be useful for photocuring (meth) acrylates with free radicals. Representative photoinitiators include benzoin and its derivatives, such as alpha-methyl benzoin; alpha-phenyl benzoin; alpha-allyl benzoin; alpha-benzyl benzoin; benzoin ethers such as benzyl dimethyl ketal (Ciba Specialty Chemicals, Tarrytown). , NY available as IRGACURE 651), benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether; acetophenone and its derivatives, such as 2-hydroxy-2-methyl-1-phenyl-1-propanone (from Ciba Specialty Chemicals) DAROCUR 1173) and 1-hydroxycyclohexyl phenyl ketone (C available from Ba Specialty Chemicals as IRGACURE 184); 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone (available from Ciba Specialty Chemicals as IRGACURE 907); 2 -Benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone (available from Ciba Specialty Chemicals as IRGACURE 369); and (phenylbis (2,4,6-trimethyl) Benzoyl) phosphine oxide (available as IRGACURE 819 from Ciba Specialty Chemicals, NY) Other useful photoinitiators It is mono - and bis - acyl phosphine (e.g., IRGACURE 1700 from Ciba Specialty Chemicals, IRGACURE 1800, IRGACURE 1850, and available as DAROCUR 4265) can be mentioned.

  The binder precursor may comprise an effective amount, eg, 0.1, 1, or 3% by weight up to 5, 7, or even 10% by weight, or more of at least one thermal initiator. Good. Typical thermal free radical initiators include azo compounds such as 2,2-azo-bisisobutyronitrile, dimethyl 2,2′-azobis (isobutyrate), azobis (diphenylmethane), 4,4′- Azobis- (4-cyanopentanoic acid), (2,2′-azobis (2,4-dimethylvaleronitrile), available as VAZO 52 from EI du Pont de Nemours and Co. (Wilmington, DE); Peroxides such as benzoyl peroxide, cumyl peroxide, t-butyl peroxide, cyclohexanone peroxide, glutaric acid peroxide and dilauroyl peroxide; hydrogen peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene Hydroperoxides; peracids such as peracetic acid and perbenzoate ; Potassium persulfate; and peresters, for example, diisopropyl percarbonate.

  In some embodiments, one or more monoethylenically unsaturated free radical polymerizable compounds in the binder precursor, for example, to reduce the viscosity of the resulting binder and / or to reduce crosslink density. It may be desirable to include. Typical monoethylenically unsaturated free radical polymerizable compounds include hexyl (meth) acrylate, 2-ethylhexyl acrylate, isononyl (meth) acrylate, isobornyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxyethyl. (Meth) acrylate, dodecyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-octyl (meth) acrylate, isobutyl (meta ) Acrylates, cyclohexyl (meth) acrylates, or mono (meth) acrylates including octadecyl (meth) acrylate; N-vinyl compounds such as N-vinylformamide, N-vinylpyrrolidinone Or N- vinylcaprolactam; and combinations thereof.

  In some embodiments, the polishing layer may include one additive. Additives can include one or more of antioxidants, colorants, heat and light stabilizers, or fillers (fillers that do not substantially affect polishing performance). Thus, a binder is typically prepared from a binder precursor that includes abrasive particles, a surfactant, and additives, in which the abrasive particles are dispersed (eg, as a slurry).

  Provided structured abrasive articles comprising shaped abrasive composites can be made from common methods known in the art. For example, in one embodied method, a binder precursor and abrasive particles in slurry form can be placed in complementary cavities of a production tool having the desired shaped abrasive composite dimensions. The translucent film backing can then be brought into contact with the production tool and the slurry precursor and binder precursor can be cured to a degree sufficient to at least remove the shaped abrasive composite from the production tool. Alternatively, the production tool, at least translucent film backing, and slurry can be fed simultaneously through the nip. If desired, further curing (eg, thermal post-curing) can be performed at this stage to further advance the degree of curing and improve the properties of the binder. Further details regarding methods of forming shaped abrasive composites can be found, for example, in US Pat. No. 5,152,917 (Pieper et al.).

  The individual shaped abrasive composites can be in the form of various geometric solids or irregular shapes. Typically, the shaped abrasive composite is precisely shaped (as defined above). Typically, the shaped abrasive composite is formed such that the base of the shaped abrasive composite, eg, a portion of the shaped abrasive composite, is in contact with and secured to at least a translucent film backing. The proximal portion of the shaped abrasive composite typically has the same or greater surface area as the portion of the shaped abrasive composite distal to the base or backing. Precision molded abrasive composites have cubes, cylinders, prisms (eg hexagonal prisms), rectangular pyramids, truncated pyramids, cones, hemispheres, truncated cones, crosses, or distal ends It may be selected from many geometric solids such as columnar cross sections. The pyramid composite material may have four, five, or six sides. The shaped abrasive composite may also be a mixture of various shapes. The shaped abrasive composites may be arranged in a row, arranged in concentric circles, spirally, in a lattice shape, or randomly placed.

  The side that forms the shaped abrasive composite may be perpendicular to the backing, inclined with respect to the backing, or tapered so that the width gradually decreases toward the distal end. Good. However, when the sides are tapered, the shaped abrasive composite can be more easily removed from the mold or the cavity of the production tool. A substantially vertical angle is preferred because a nominal contact area can be consistently obtained when the composite is worn away.

  The height of each shaped abrasive composite is typically substantially the same, but it is also envisioned to have composites that vary in height in a single structured abrasive article. The height of the composite with respect to the lands between the backing or composite is generally less than about 2,000 micrometers, for example, may range from about 10 micrometers to about 250 micrometers. The base dimensions of individual molded abrasive composites may be about 5,000 micrometers or less, typically about 1,000 micrometers or less, more typically less than 500 micrometers. The base dimensions of individual molded abrasive composites are typically greater than about 50 micrometers, more typically greater than about 100 micrometers. The bases of the shaped abrasive composite may be in contact with each other or may be separated from each other by some specific distance.

  Adjacent molded composites may share a common molded abrasive composite land or bridge-like structure that contacts and extends between opposite sidewalls of the composite. Typically, the land structure has a height that is no more than about 33% of the vertical height dimension of each adjacent composite. The shaped abrasive composite land may be formed from the same slurry used to form the shaped abrasive composite. Composites are “adjacent” in the sense that there is no intervening composite that can be located on a straight imaginary line drawn between the centers of the composites. At least some of the shaped abrasive composites may be separated from each other to provide a recessed region between the raised portions of the composite.

  The linear spacing of the shaped abrasive composite may range from about 1 shaped abrasive composite per 1 cm straight line to about 200 shaped abrasive composites per 1 cm straight line. The linear interval may be changed so that the concentration of the composite material is greater at one location than at other locations. For example, the concentration can be maximum at the center of the abrasive article. The areal density of the composite may range from about 1 to about 40,000 composites per square centimeter in some embodiments. One or more regions of the backing may be exposed, i.e., the region does not have an abrasive coating in contact with at least a translucent film backing.

  The shaped abrasive composites are typically arranged on the backing in a predetermined pattern, or arranged in a predetermined position on the backing. For example, in an abrasive article made by supplying a slurry between a backing and a production tool having cavities therein, the predetermined pattern of the composite material corresponds to the pattern of the cavities of the production tool. Thus, the pattern can be reproducible from article to article. In one embodiment, the shaped abrasive composites may form an array or arrangement that is a rule such as rows and columns in which the composite is aligned and columns or alternately offset. May mean a typical sequence. If desired, the first row of shaped abrasive composites may be directly aligned before the second row of shaped abrasive composites. Typically, the first row of shaped abrasive composites may be offset from the second row of shaped abrasive composites.

  In another embodiment, the shaped abrasive composites may be arranged in a “random” arrangement or pattern. This may mean that the composite material is not a regular array of rows and columns as described above. For example, the shaped abrasive composites can be arranged by methods as disclosed in US Pat. Nos. 5,672,097 and 5,681,217 (both from Hopman et al.). However, this “random” arrangement is a predetermined pattern in that the position of the composite on the abrasive article is predetermined and can correspond to the position of the cavity in the production tool used to create the abrasive article. It is understood that this is possible.

  Typical production tools include rolls, endless belts, and webs, made from suitable materials such as, for example, metals (eg, in the case of rolls) or polymer films (eg, in the case of endless belts and webs). obtain.

  Provided structured abrasive articles may generally be round in shape, for example in the form of an abrasive disc. The outer edge of the abrasive disc is typically smooth or may be wavy. The structured abrasive article may be in the form of an ellipse or any polygonal shape such as a triangle, square, rectangle or the like. Alternatively, the abrasive article may be in the form of a belt. The abrasive article may be provided in the form of a roll commonly referred to in the abrasive art as an abrasive tape roll. In general, the abrasive tape roll may be indexed or moved continuously during the wafer planarization process. The abrasive article can be perforated to create an opening through the abrasive coating and / or backing, allowing hydraulic fluid to pass through before, during and / or after use. Structured abrasive articles have substantially or even no such perforations.

  The precisely molded abrasive composite may have any three-dimensional shape as long as at least one of a convex portion or a concave portion is formed on the exposed surface of the polishing layer. Examples of useful shapes include a cube, a prism, a pyramid (for example, a square pyramid or a hexagonal pyramid), a truncated pyramid, a circular cone, and a truncated cone. Combinations of abrasive composites of different shapes and / or sizes may be used. The abrasive layer of the structured abrasive may be continuous or discontinuous. Further details regarding structured abrasive articles having precisely shaped abrasive composites and methods of making the same can be found in, for example, U.S. Pat. Nos. 5,435,816 (Spurgeon et al.), 5,454,844 (Hibbard). Et al., 5,851,247 (Stoetzel et al.), And 6,139,594 (Kincaid et al.).

  Typically, the shaped abrasive composite is placed on the backing according to a predetermined pattern or arrangement, but this is not essential. The shaped abrasive composite may be arranged such that a part of the workpiece is recessed by polishing the surface of the abrasive layer.

  The translucent film backing of the structured abrasive article can typically be brought into contact with the subpad during use. In some cases, the structured abrasive article can be secured to the subpad. The abrasive layer may be applied to the front surface of at least a translucent film backing, and an adhesive, such as a pressure sensitive adhesive (or mechanical fastening device) is applied to the opposing surface of the at least translucent film backing. Can be applied. Suitable subpads are disclosed, for example, in US Pat. Nos. 5,692,950 and 6,007,407, both of which are Rutherford et al. When using an optical detection method, the subpad and any platen on which it is placed are provided with at least one appropriately sized window (eg, an opening or transparent insert) and a light source (eg, a laser) A continuous light path through the platen and subpad should be obtained.

The provided structured abrasive articles can be fabricated to have sufficient light transmission suitable for use in optical detection methods such as, for example, laser interferometry. For example, the structured abrasive article has at least 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, over any wavelength range, for example, a range corresponding to the output wavelength of the laser. It may have a light transmission of 4.5 or even 5.0 percent or more. Typical laser wavelengths include 694 nm (ruby), 676.4 nm (Kr-ion), 647.1 nm (Kr-ion), 635-660 nm (InGaAlP semiconductor), 633 nm (HeNe), 628 nm (ruby), 612 nm. (HeNe), 578 (Cu vapor), 568.2 nm (Kr-ion), 543 nm (HeNe), 532 nm (DPSS semiconductor), 530.9 nm (Kr-ion), 514.5 nm (Ar-ion), 511 nm ( Cu vapor), 501.7 nm (Ar), 496.5 nm (Ar), 488.0 nm (Ar), 476.5 nm (Ar), 457.9 nm (Ar), 442 nm (HeCd), or 428 nm (N ₂ ⁺ ).

  Provided structured abrasive articles include workpieces such as silicon containing wafers (eg, silicon wafers, glass wafers, etc.), or other metal containing wafers, and wafers having an oxide layer on the outer surface thereof. It can be used for polishing and / or polishing. For example, the structured abrasive article may be useful for polishing and / or polishing dielectric material deposited on the wafer and / or on the wafer itself. Further, the provided abrasive articles can be useful for polishing or polishing other materials such as sapphire or other minerals. Variables affecting wafer polishing speed and properties include, for example, selection of an appropriate contact pressure between the wafer surface and the abrasive article, type of hydraulic fluid, relative speed and relative motion between the wafer surface and the abrasive article. As well as the flow rate of the working fluid. These variables are independent and are typically selected based on the individual wafer surface being processed.

  Structured abrasive articles according to the present disclosure may use a pad conditioner (eg, including coarse diamond grains held in a metal matrix) prior to and / or intermittently during the wafer planarization process. Conditioning can be achieved by polishing the surface. One useful conditioner is a CMP pad conditioner (typically mounted on a rigid backing plate), model number CMP-20000TS (available from Morgan Advanced Ceramics, Hayward, Calif.).

  In general, since a large number of process steps can exist for one semiconductor wafer, a process with a relatively high material removal rate is expected in the semiconductor manufacturing industry. The material removal rate obtained with a particular abrasive article typically varies with machine conditions and the type of wafer surface being processed. However, although it is typically desirable to have a high conductor or dielectric material removal rate, the conductor or dielectric material removal rate can be achieved with a desired surface finish and / or topography of the wafer surface. Can be selected so as not to damage.

  Referring to FIG. 2, in an exemplary method for conditioning the surface of a wafer, structured abrasive article 100 is in contact with and secured to subpad 210 and then secured to platen 220. Subpad 210, which may include foam (eg, polyurethane foam) or other compressible material, has a first window 212 therein and platen 220 has a second window 222 therein. Wafer holder 233 is mounted on head unit 231 connected to a motor (not shown). The gimbal chuck 232 extends from the head unit 231 to the wafer holder 233. The wafer holder 233 assists in fixing the wafer 240 to the head unit 231 and prevents the semiconductor wafer from coming off during planarization. The wafer holder 233 extends in parallel with the wafer 240 at the annular portion 233a. The annular portion 233a (optional) may be a separate part or may be integrated with the wafer holder 233. Wafer 240 is brought into contact with polishing layer 120 of structured abrasive article 100, and wafer 240 and polishing layer 120 move relative to each other. The progress of polishing / polishing is monitored using a laser beam 250 that passes through the second window 222, the first window 212, and the structured abrasive article 100, is reflected from the oxide surface 242 wafer 240, and then returns the path. Is done. Optional hydraulic fluid 260 may be used to facilitate the polishing process. The reservoir 237 holds any working fluid 260 that is pumped through the tube 238 at the interface between the semiconductor wafer and the polishing layer. Useful hydraulic fluids include, for example, those listed in US Pat. No. 5,958,794 (Bruxvoort et al.).

  In general, it is desirable that the surface finish of the wafer be substantially free from scratches and defects. The finish of the wafer surface can be evaluated by known methods. One method is to provide a measure of roughness and measure an Rt value that can indicate scratches or other surface defects. The wafer surface typically has an Rt value of about 0.4 nanometers or less, more typically about 0.2 nanometers or less, and even more typically about 0.05 nanometers or less. To be modified. Rt is typically measured using a laser interferometer such as a Wyko RST PLUS interferometer (Wyko Corp., Tucson, AZ) or a Tencor surface meter (KLA-Tencor Corp., San Jose, Calif.). Scratch detection can be measured by a dark field microscope. The scratch depth can be measured by an atomic force microscope.

  Wafer surface processing may be performed in the presence of a working fluid that can be selected based on the composition of the wafer surface. For some applications, the hydraulic fluid typically includes water. The hydraulic fluid may be combined with the abrasive article to assist in processing by a chemical mechanical polishing process. During the polishing chemical step, the hydraulic fluid may react with the outer or exposed surface of the wafer. And during the mechanical steps of processing, the abrasive article can remove this reaction product.

  Currently, memory storage devices and other electronic devices tend to be miniaturized. There is a need for an abrasive article that can polish a wafer having very small nodes without causing defects. Some typical devices are only as large as 32 nm and even 28 nm. In order to polish these wafers, it is important that the abrasive article can produce a smooth surface with few defects at a relatively high speed. There is a need for an abrasive article that can polish a wafer having very small nodes without causing defects. Some typical devices are only as large as 32 nm and even 28 nm. In order to polish these wafers, it is important that the abrasive article can produce a smooth surface with few defects at a relatively high speed. Furthermore, after polishing, wafers that can be 100 mm or more in diameter should have a uniform profile with minimal step (edges are more worn than the center). Surprisingly, structured abrasive articles comprising a polymeric binder in which abrasive particles and a nonionic surfactant are dispersed have an average particle size of the abrasive particles of less than about 200 nm, less than about 150 nm, less than 140 nm, or even Less than 130 nm, polyether type nonionic surfactant is 0.75% to 2.2%, 1.0% to 2.2%, 1.3% by weight of the structured adhesive It has been found to remove material from a thermal oxide wafer at a rate in excess of 1500 liters / minute when present in an amount of -2.2 wt%, or even 1.5 wt% to 2.0 wt%. Table 1 in the Examples section shows this result. The provided abrasive article has a polishing particle size, an amount of a polyether type nonionic surfactant, and an appropriate amount of the surfactant dispersed in the cross-linking agent so that there are few defects and cross-wafer uniformity. It has a structure that is good and has a high wafer removal rate in a special combination.

  The purpose and advantages of this disclosure are further illustrated by the following non-limiting examples, but the specific materials and amounts thereof, as well as other conditions and details cited in these examples, unduly limit this disclosure. Should not be construed to do.

Example 1 Preparation of Fixed Abrasive Web-containing Ceria Dispersion 1 with 1% Surfactant Ceria Dispersion 1 (11.4045 kg, 51.06% solids in water, average particle size 132 nm, Ferro Corporation (Independence, OH)) 703 grams of 2- (2-methoxyethoxy) ethoxyacetic acid, 568 grams of β-carboxyl while mixing with a polytetrafluoroethylene coated blade. Ethyl acrylate (acid # 5.9-6.0) and 2.7907 kg of 1-methoxy-2-propanol were added slowly. The mixture was heated to 50 ° C. and mixed overnight. The mixture was then transferred to a rotary evaporator and excess water was removed under reduced pressure. The resulting dispersion had a solids content of 49.32 percent.

Preparation of Slurry 1 45.000 kg of ceria dispersion 1,665.8 grams of DISPERBYK-111 wetting and dispersing additive (available from BYK-Chemie USA, Inc. (Wallingford, Conn.)) Was mixed in a mixing vessel. To this mixture was added 125.9 grams 2-hydroxyethyl methacrylate (available from Rohm and Haas Co. (Philadelphia, PA)), 318.7 grams 2-phenoxyethyl acrylate (Sartomer Co. (Exton, PA)). (Available as SR 339), 2.445 kg of trimethylolpropane triacrylate (available as SR 351 from Sartomer Co.), 137.1 grams of β-carboxyethyl acrylate (available from Bimax Inc. (Cockeysville, MD)) ), 256.1 grams of TERGITAL 15-7-S (available from Sigma Aldrich Inc.) and 15.13 grams of phenoxyazine dissolved Lamb 1-methoxy-2-propanol was added. The mixture was mixed for 30 minutes using a polytetrafluoroethylene coated blade and then transferred to a rotary evaporator to remove 1-methoxy-2-propanol. The slurry was cooled to room temperature and then 26.16 grams of free radical photoinitiator (Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide available from Ciba Specialty Chemicals (Tarrytown, NY) as IRGACURE 819 ), 26.16 grams of thermal free radical initiator (2,2′-azobis (2,4-dimethylvaleronitrile) (available as VAZO 52 from EI du Pont de Nemours and Co. (Wilmington, DE)) Possible) and 6.54 grams of hydroquinone monomethyl ether and added for an additional 2 hours.

Example 1
A 30 inch (76 cm) wide polypropylene production tool roll was provided. The polypropylene production tool was a polypropylene film with a hexagonal array (350 μm between centers) of hexagonal column cavities (125 μm wide, 30 μm deep) corresponding to 10 percent of the cavitation area. The production tool was essentially the inverse of the shape, dimensions, and arrangement desired for the abrasive composite of the final structured abrasive article. Method 4 disclosed in US Pat. No. 7,497,885 (Kollodge) describes the tool and its use in more detail. Using a casting roll and nip roll (nip force of 1300 pounds (5.78 kN)), a roll of production tool cavity and translucent polycarbonate / PBT based film backing material (7 mil (0.18 mm) thick) , Available as BAYFOL CR6-2 from Bayer Corp. (Pittsburgh, Pa.), Then slurry 1 and then a line speed of 10 ft / min (3.0 m / min) and 6.0 kW A UV source (V bulb, EPIQ model available from Fusion Systems) was passed through at a total exposure of / inch (2.36 kJ / hr / cm). After UV curing, the resulting structured abrasive article (SA1) was removed from the production tool.

The wafer pressure was 3.0 lb / in ² (20.7 kPa), the platen speed was 30 revolutions / minute, and the web index speed was 8 millimeters per minute, and Applied Materials, Inc. Using a CMP polisher available from (Santa Clara, Calif.) Under the trade name Reflexion polisher, SA1 is used to polish thermal oxide blanket wafers (having a micrometer film thickness of silicon oxide on the surface and a diameter of 200 mm). used. As shown in the graph above, the average removal rate measured on the thermal oxide wafer is 1625 liters / minute, with an unexpectedly fast center, which regulates the pressure on the wafer. This provides an option to get the wafer profile in good condition and optimal uniformity.

Example 2-Fixed abrasive web containing -2% surfactant Preparation of ceria dispersion 2 Ceria dispersion (102.195 kg, 51.56% solids in water, average particle size 135 nm, Ferro Corporation (Independence, OH) 622 grams of 2- (2-methoxyethoxy) ethoxyacetic acid, 503 grams of β-carboxyl while mixing with a polytetrafluoroethylene-coated blade. Ethyl acrylate and 2.44752 1-methoxy-2-propanol were slowly added. The mixture was heated to 50 ° C. and mixed overnight. The mixture was then transferred to a rotary evaporator and excess water was removed under reduced pressure. The resulting dispersion had a solid content of 49.13 percent.

Preparation of slurry 2 45.000 kg of ceria dispersion, 2,733.8 grams of DISPERBYK-111 wetting and dispersing additive (available from BYK-Chemie USA, Inc. (Wallingford, Conn.)) Were mixed in a mixing vessel. . To this mixture, 125.4 grams of 2-hydroxyethyl methacrylate (available from Rohm and Haas Co. (Philadelphia, PA)), 317.5 grams of 2-phenoxyethyl acrylate (Sartomer Co. (Exton, PA)). (Available as SR 339), 2.435 kg trimethylolpropane triacrylate (available as SR 351 from Sartomer Co.), 136.6 grams β-carboxyethyl acrylate (available from Bimax Inc. (Cockeysville, MD)) ), 464.3 grams of 502.5 grams of TERGITOL 15-7-S (available from Sigma Aldrich Inc.) and 15.07 grams of phenoxyazine. Lamb 1-methoxy-2-propanol was added. The mixture was mixed for 30 minutes using a polytetrafluoroethylene coated blade and then transferred to a rotary evaporator to remove 1-methoxy-2-propanol. Cool the slurry to room temperature and then obtain 27.0 grams of free radical photoinitiator (Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Ciba Specialty Chemicals (Tarrytown, NY) as Ciba IRGACURE 819) 27.0 grams of thermal free radical initiator (2,2′-azobis (2,4-dimethylvaleronitrile) (EI Du Pont de Nemours and Co. (Wilmington, DE) to VAZO 52) And 6.75 grams of hydroquinone monomethyl ether were added and mixed for an additional 2 hours.

(Example 2)
A 30 inch (76 cm) wide polypropylene production tool roll was provided. The polypropylene production tool was a polypropylene film with a hexagonal array of hexagonal column cavities (125 micrometers wide, 30 micrometers deep) (350 micrometers between centers), corresponding to 10 percent of the cavitation area. The production tool was essentially the inverse of the shape, dimensions, and arrangement desired for the abrasive composite of the final structured abrasive article. Using a casting roll and nip roll (nip force of 1300 pounds (5.78 kN)), a roll of production tool cavity and translucent polycarbonate / PBT based film backing material (7 mil (0.18 mm) thick) , Available as a BAYFOL CR6-2 from Bayer Corp. (Pittsburgh, Pa.), Then slurry 2 and then a line speed of 10 feet / minute (3.0 m / minute) and 6000 watts / inch A UV source (V bulb, EPIQ model available from Fusion Systems) was passed through with a total exposure (2.36 kJ / hr / cm). After UV curing, the resulting structured abrasive article (SA2) was removed from the production tool.

The wafer pressure was 3.0 lb / in ² (20.7 kPa), the platen speed was 30 revolutions / minute, and the web index speed was 8 millimeters per minute, and Applied Materials, Inc. SA2 to polish thermal oxide blanket wafers (having a micrometer film thickness of silicon oxide on the surface and a diameter of 200 mm) using a CMP polisher available under the trade name REFLEXION polisher from (Santa Clara, CA) used. As shown in the graph above, the average removal rate measured on the thermal oxide wafer is 2011 Å / min, and unexpectedly has a fast center profile, which regulates the pressure on the wafer. This provides an option to get the wafer profile in good condition and optimal uniformity.

Comparative Example 1-Preparation of Surfactant-Free Fixed Abrasive Web Slurry 3 45.000 kg Ceria Dispersion 2,663.3 grams DISPERBYK-111 Wetting and Dispersing Additive (BYK-Chemie USA, Inc. (Wallingford, CT)) was mixed in a mixing vessel. To this mixture, 125.4 grams of 2-hydroxyethyl methacrylate (available from Rohm and Haas Co. (Philadelphia, PA)), 317.5 grams of 2-phenoxyethyl acrylate (Sartomer Co. (Exton, PA)). (Available as SR 339), 2.4354 kg of trimethylolpropane triacrylate (available as SR 351 from Sartomer Co.), 136.6 grams of β-carboxyethyl acrylate (available from Bimax Inc. (Cockeysville, MD)) ), And 464.3 grams of 15.07 grams of phenothiazine dissolved therein was added to 1-methoxy-2-propanol. The mixture was mixed for 30 minutes using a polytetrafluoroethylene coated blade and then transferred to a rotary evaporator to remove 1-methoxy-2-propanol. Cool the slurry to room temperature and then obtain 20.04 grams of free radical photoinitiator (Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Ciba Specialty Chemicals (Tarrytown, NY) as Ciba IRGACURE 819) Possible)) 20.04 grams of thermal free radical initiator (2,2′-azobis (2,4-dimethylvaleronitrile) (EI du Pont de Nemours and Co. (Wilmington, DE) to VAZO 52) And 5.01 grams of hydroquinone monomethyl ether were added and mixed for an additional 2 hours.

Comparative Example 1
A 30 inch (76 cm) wide polypropylene production tool roll was provided. The polypropylene production tool was a polypropylene film with a hexagonal array (350 μm between centers) of hexagonal columnar cavities (width 125 μm, depth 30 μm) corresponding to 10 percent of the cavitation area. The production tool was essentially the inverse of the shape, dimensions, and arrangement desired for the abrasive composite of the final structured abrasive article. Using a casting roll and nip roll (nip force of 1300 pounds (5.78 kN)), a roll of production tool cavity and translucent polycarbonate / PBT based film backing material (7 mil (0.18 mm) thick) , Available as BAYFOL CR6-2 from Bayer Corp. (Pittsburgh, Pa.), And then coated with slurry 3 and then a line speed of 10 feet / minute (3.0 m / minute) and 6000 watts / inch A UV source (V bulb, EPIQ model available from Fusion Systems) was passed through with a total exposure (2.36 kJ / hr / cm). After UV curing, the resulting structured abrasive article (SA3) was removed from the production tool.

The wafer pressure was 3.0 lb / in ² (20.7 kPa), the platen speed was 30 revolutions / minute, and the web index speed was 5 millimeters per minute, and Applied Materials, Inc. Using a CMP polisher available from (Santa Clara, CA) under the trade name REFLEXION polisher, SA3 is used to polish thermal oxide blanket wafers (having a micrometer film thickness of silicon oxide on the surface and a diameter of 200 mm). used. As shown in the graph above, the average removal rate measured on a thermal oxide wafer is 742 Å / min, typically having a cross-wafer profile with a slow center and fast edges, It is difficult to overcome.

Comparative Example 2-3 Preparation of Fixed Abrasive Web Slurry 4 Containing Surfactant 1.0747 kg Ceria Dispersion 2, 15.8 grams DISPERBYK-111 Wetting and Dispersing Additive (BYK-Chemie USA, Inc. (Wallingford , CT)) in a mixing vessel. To this mixture was added 3.00 grams of 2-hydroxyethyl methacrylate (available from Rohm and Haas Co. (Philadelphia, PA)), 7.58 grams of 2-phenoxyethyl acrylate (Sartomer Co. (Exton, PA)). SR 339), 58.16 grams of trimethylolpropane triacrylate (available as SR 351 from Sartomer Co.), 3.26 grams of β-carboxyethyl acrylate (Bimax Inc. (Cockeysville, MD)) Possible), 18.0 grams of TERGITAL 15-7-S (available from Sigma Aldrich Inc.) and 20 grams of 1-methoyl in which 0.36 grams of phenoxyazine is dissolved. Xyl-2-propanol was added. The mixture was mixed for 30 minutes using a polytetrafluoroethylene coated blade and then transferred to a rotary evaporator to remove 1-methoxy-2-propanol. The slurry is cooled to room temperature and then 0.65 grams of free radical photoinitiator (Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide available from Ciba Specialty Chemicals (Tarrytown, NY) as IRGACURE 819 )), 0.65 grams of thermal free radical initiator (2,2′-azobis (2,4-dimethylvaleronitrile) (EI du Pont de Nemours and Co. (Wilmington, DE) as VAZO 52) Available) and 0.16 grams of hydroquinone monomethyl ether and added for an additional 2 hours.

  A 30 inch (76 cm) wide polypropylene production tool roll was provided. The polypropylene production tool was a polypropylene film with a hexagonal array of hexagonal column cavities (125 micrometers wide, 30 micrometers deep) (350 micrometers between centers), corresponding to 10 percent of the cavitation area. The production tool was essentially the inverse of the shape, dimensions, and arrangement desired for the abrasive composite of the final structured abrasive article. Using a casting roll and nip roll (nip force of 1300 pounds (5.78 kN)), a roll of production tool cavity and translucent polycarbonate / PBT based film backing material (7 mil (0.18 mm) thick) , Available from Bayer Corp. (available from Pittsburgh, PA) as BAYFOL CR6-2, and then line speed of 10 ft / min (3.0 m / min) and 6000 watt / inch A UV source (V bulb, EPIQ model available from Fusion Systems) was passed through with a total exposure (2.36 kJ / hr / cm). After UV curing, the resulting structured abrasive article (SA4) was removed from the production tool.

The wafer pressure was 3.0 lb / in ² (20.7 kPa), the platen speed was 30 revolutions / minute, and the web index speed was 8 millimeters per minute, and Applied Materials, Inc. Using a CMP polisher available from (Santa Clara, Calif.) Under the trade name REFLEXION polisher, SA4 is used to polish thermal oxide blanket wafers (having a micrometer film thickness of silicon oxide on the surface and a diameter of 200 mm). used. Damage to the film was observed during polishing, making it impossible to polish the wafer.

Comparative Example 3-Surfactant Added to Polishing Liquid Applied Materials with a wafer pressure of 3.0 lb / in ² (20.7 kPa), a platen speed of 30 revolutions / minute, and a web index speed of 5 millimeters per minute. , Inc. Using a CMP polisher available from (Santa Clara, CA) under the trade name REFLEXION polisher, SA3 is used to polish thermal oxide blanket wafers (having a micrometer film thickness of silicon oxide on the surface and a diameter of 200 mm). used. Based on the calculation, an amount of TERGITOL equivalent to the FA web in Example 2 was added to the polishing liquid. As shown in FIG. 3, the average removal rate measured on the thermal oxide wafer was 793 ７９ / min, typically having a cross-wafer profile with a slow center and fast edges.

  The removal rates in Examples and Comparative Examples are shown in Table 1.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope and spirit of the invention. The present invention is not intended to be unnecessarily limited by the exemplary embodiments and examples described herein, and these examples and embodiments are given by way of example only, and It should be understood that the scope of the invention is limited only by the "claims" set forth herein below. All references cited in this disclosure are hereby incorporated by reference in their entirety.

Claims (17)

A structured abrasive article comprising:
A structured abrasive layer disposed on and secured to the first major surface, the structured abrasive layer comprising: a backing having first and second opposing major surfaces; and
Polymer binders;
Abrasive particles dispersed in the binder; and a polyether type nonionic surfactant dispersed in the binder;
The abrasive particles have an average particle size of less than about 200 nm;
The polyether-type nonionic surfactant is not covalently bonded to the crosslinked polymer binder;
A structured abrasive article wherein the polyether-type nonionic surfactant is present in an amount of 0.75 to 2.2 wt%, based on the total weight of the structured adhesive layer.   The structured polishing according to claim 1, wherein the polyether-type nonionic surfactant is present in an amount of 1.0 wt% to 2.2 wt%, based on the total weight of the structured adhesive layer. Goods.   The structured abrasive article of claim 1, wherein the shaped abrasive composite is precisely shaped.   The structured abrasive article of claim 1, wherein the crosslinked polymer binder comprises an acrylic polymer.   The structured abrasive article of claim 1, wherein the surfactant comprises a polyethylene oxide segment.   The structured abrasive article of claim 1, wherein the surfactant comprises a polypropylene oxide segment. The shaped abrasive composite further comprises a nonionic phosphate polyether ester;
The structured abrasive article of claim 1, wherein the nonionic phosphate polyether ester is present in a smaller amount than a polyether type nonionic surfactant.   The structured abrasive article of claim 1, wherein the backing comprises a polymer film.   The structured abrasive article of claim 8, wherein the polymer film comprises an elastomeric polyurethane.   The structured abrasive article of claim 1, wherein the backing comprises a polymer foam.   The structured abrasive article of claim 1, further comprising an attachment interface layer directly bonded to the second major surface.   The structured abrasive article of claim 11, wherein the attachment interface layer comprises a pressure sensitive adhesive disposed on the second major surface.   The structured abrasive article of claim 11, wherein the attachment interface layer comprises a looped fabric. A method for polishing a workpiece,
Frictionally contacting at least a portion of the structured abrasive article and the surface of the workpiece in the presence of an aqueous fluid, and moving at least one of the workpiece or the structured abrasive layer relative to the other, Polishing at least a portion of the surface of the workpiece;
The structured abrasive article comprises:
A backing having first and second opposing main surfaces; and a structured polishing layer disposed on and secured to the first main surface, the structured polishing layer comprising:
Polymer binders;
Abrasive particles dispersed in the binder; and a polyether type nonionic surfactant dispersed in the binder;
The abrasive particles have an average particle size of less than about 200 nm;
The polyether-type nonionic surfactant is not covalently bonded to the cross-linked polymer binder, and the polyether-type nonionic surfactant is 0.75, based on the total weight of the structured adhesive layer. A process present in an amount of -2.2% by weight.   The method of polishing a workpiece according to claim 14, wherein the workpiece is an oxide wafer.   15. A method for polishing a workpiece according to claim 14, wherein the workpiece comprises silicon.   The method for polishing a workpiece according to claim 14, wherein the aqueous fluid includes tap water.

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