Compositions and methods for reducing interaction of abrasive particles with a cleaning brush

Abstract

Methods of removing abrasive particles from a polymer surface, such as from a cleaning brush used in a post-chemical mechanical treatment cleaning step; and related cleaning solutions.

Description

Technical Field

[0001] This invention relates to a method for removing abrasive particles from polymer surfaces, such as those of cleaning brushes used in post-chemical mechanical cleaning steps. Background Technology

[0002] In the technical field related to the production (manufacturing) of microelectronic devices, which include integrated circuits, optical devices, memory devices, magnetoelectric components, and other microdevices or microdevice components for electronic, memory, optical, and similar applications, microelectronic devices are fabricated by including steps involving the precise removal of material from a substrate surface. Methods for fabricating certain devices may include a series of steps involving the deposition and selective removal of different materials from a substrate surface. The materials used during processing may be conductive materials, such as metals, semiconductor materials, such as silicon-based materials (e.g., silicon oxide), dielectric layers, or polymer materials. The materials may be selectively coated and selectively removed at the surface in a manner that constructs a microelectronic structure layer on the substrate. Materials may be removed by selective chemical means, abrasive means, or a combination of these means.

[0003] In the fabrication of these devices, a treatment step is typically used to planarize, smooth, or polish the substrate surface by abrasion. The surface is treated between steps of selectively coating and removing material from the surface to provide a highly refined finish (e.g., planarization, smoothing, or polishing). A standard technique for this treatment is chemical-mechanical processing (CMP). In CMP, the substrate surface is brought into contact with an abrasive slurry and a CMP pad, with relative movement between the pad and the surface. The slurry contains a liquid carrier (water or an organic solvent), dissolved chemicals (i.e., organic chemical materials), and dispersed abrasive particles. (The surface will typically include particulate byproducts, such as various types of metal oxides, which emerge from previous treatment steps.) The combination of slurry components and the movement between the pad and the substrate surface effectively removes material from the substrate surface and provides a planarized or polished surface for further processing.

[0004] Following the CMP step, various materials that were part of the slurry, as well as materials that have been removed from the substrate surface, remain on the substrate surface in the form of chemicals or abrasive residues. Chemical residues can be residual chemical components present on the substrate surface after CMP treatment, and they are chemical materials or their derivatives (e.g., reaction products) initially present in the CMP slurry. Abrasive particle residues refer to abrasive particles initially present in the CMP slurry and remaining on the substrate surface at the end of the CMP step. Other types of residues can be combinations of abrasive particles and chemical residues, such as aggregated, condensed, or precipitated organic and abrasive particle materials.

[0005] During the processing of microelectronic devices, for example, after or between CMP steps, significant effort is made to remove residues from the substrate surface. Specifically, residues in the form of residual abrasive particles must be removed from the substrate surface because these particles can cause surface defects such as scratches, as well as device defects in the form of embedded particles, which can negatively impact the quality of downstream substrate processing or downstream products. Methods for removing residues including residual abrasive particles include cleaning techniques, sometimes referred to as “post-CMP cleaning” techniques, methods, or steps. These methods involve using a cleaning solution coated on the substrate surface containing the residue, and contact with a moving polymer brush to chemically and mechanically remove the residue from the surface.

[0006] Various CMP post-cleaning equipment and solutions are commercially available. Example equipment includes a cleaning chamber containing a moving brush and a system that dispenses a cleaning solution onto a substrate surface within the chamber and provides movement and contact between the substrate and the brush. The chamber is typically heated to facilitate cleaning. In use, the cleaning solution is applied to the substrate surface, and the surface is brought into contact with the moving brush to remove residues. While examples of these types of equipment and methods are known, commercially applicable, and capable of efficient and effective CMP post-cleaning of a wide variety of substrates, there is always a need to improve existing technologies and develop new, and even more effective, cleaning solutions and methods to remove residues from CMP substrate surfaces. Summary of the Invention

[0007] This invention relates to methods and compositions for removing abrasive particles from polymer surfaces, such as those of cleaning brushes used in post-CMP cleaning steps, and related cleaning solutions. The applicant has determined that abrasive particles, particularly those with hydrogen-bonded groups on their surface, positive charges (positive zeta potential (ζ-potential)) in the cleaning solution used in post-CMP cleaning steps, or both, can be attracted by hydrogen-bonded groups present on the polymer surface of the cleaning brush during the post-CMP cleaning step.

[0008] During substrate processing in microelectronic devices, prior to the post-CMP cleaning step, the substrate may have residues, such as residual abrasive particles, on its surface. During the post-CMP cleaning step, these abrasive particles are removed (at least most) from the substrate surface and dispersed in the cleaning solution used for the post-CMP cleaning step. In the cleaning solution, especially under low pH conditions (e.g., below 6 or 7), the dispersed abrasive particles can exhibit a positive charge, i.e., a positive zeta potential. The surface of the abrasive particles may also include hydrogen-bonded groups, such as (-OH) groups, for example, silanol (-SiOH) groups in the case of silica particles. The positively charged particle surface with hydrogen-bonded groups is electrostatically attracted to the surface of the polymer brush used in the post-CMP cleaning step and can form hydrogen bonds with the hydrogen-bonded groups present there. The abrasive particles can be attracted to the surface of the polymer brush and can accumulate there, and especially in the presence of a cleaning solution with a low pH, the attraction to the surface can be maintained by hydrogen bonding. One potential consequence of the presence and accumulation of abrasive particles on the surface of the cleaning brush during the post-CMP cleaning step is the appearance of brush marks after the CMP cleaning step.

[0009] As used herein, a "hydrogen-bonding group," as characterized by its role as a particle remover, the polymer surface of a brush, or abrasive particles, is a polar compound or polar group capable of interacting with another hydrogen-bonding group to form a hydrogen bond. Examples include groups comprising hydrogen (H) atoms covalently bonded to highly electronegative atoms such as nitrogen (N), oxygen (O), sulfur (S), or fluorine (F). Certain specific hydrogen-bonding groups include: carboxylic acid groups, amino groups, alcohol groups, phosphin groups, phosphate ester groups, phosphonate ester groups, alkanolamine groups, carbamate groups, urea groups, carbamate groups, ester groups, betaine groups, silanol groups, or sulfur-containing groups.

[0010] According to the currently described cleaning solution and its usage, the cleaning solution includes a dissolved chemical component, called a particle remover, which effectively prevents the formation of hydrogen bonds between positively charged abrasive particles in the cleaning slurry and the polymer brush surface during the post-CMP cleaning step; inhibits or reduces the formation of hydrogen bonds between the abrasive particles and the polymer brush surface during the post-CMP cleaning step; or removes the abrasive particles that have been attracted to the surface of the polymer brush and have formed hydrogen bonds with the surface (during the post-CMP cleaning step, or in a separate brush cleaning step in the absence of a substrate).

[0011] In one aspect, the present invention relates to a method for removing abrasive particles from a post-chemical mechanical treatment (CMP) cleaning brush. The method includes: providing a post-CMP cleaning brush having a polymer surface and abrasive particle residue on the polymer surface; and providing a cleaning solution with a pH below 7. The cleaning solution contains a cleaning agent and a particle removal agent. The method further includes removing the abrasive particle residue from the polymer surface by contacting the polymer surface with the cleaning solution.

[0012] In another aspect, the present invention relates to a method for cleaning a substrate after chemical mechanical treatment (CMP). The method includes: providing a CMP post-cleaning brush having a polymer surface; and providing a cleaning solution comprising: a cleaning agent and a particle removal agent. The method further includes providing a substrate having a surface containing residues comprising abrasive particles; and removing the residues from the substrate surface by exposing both the substrate surface and the polymer surface to the cleaning solution, simultaneously contacting the substrate surface with the polymer surface and simultaneously moving the substrate surface relative to the polymer surface.

[0013] In another aspect, the present invention relates to a cleaning solution concentrate suitable for cleaning substrates in a post-chemical mechanical treatment step. The cleaning solution concentrate comprises a cleaning agent and at least 0.1% by weight of a particle remover comprising hydrogen-bonded groups. Attached Figure Description

[0014] Figure 1 The performance data of the wafer cleaned using the specific methods and materials discovered are shown.

[0015] Figure 2 The proposed printing formation mechanism is shown.

[0016] Figure 3 The FTIR spectral data of a brush with silica on a surface as described are shown.

[0017] Figure 4 The FTIR spectra of brushes with silica on their surfaces are shown under different cleaning materials.

[0018] Figure 5 The data shown is derived from the use of various cleaning solutions as described. Detailed Implementation

[0019] In various respects, this specification relates to: methods for removing abrasive particles from the surface of a cleaning brush used in a post-CMP cleaning step (the method being incorporated into the post-CMP cleaning process, or as a separate method or step for removing abrasive particles from the brush); methods for preventing the accumulation of abrasive particles on the surface of the cleaning brush during the post-CMP cleaning process to remove residues from the substrate surface; and cleaning solutions effective in these methods, wherein the cleaning solution contains a particle removal agent.

[0020] During chemical mechanical processing, or CMP or “CMP treatment,” a substrate is treated to planarize or polish its surface by controlled removal of small amounts of material from the surface. A microelectronic device substrate, or simply “substrate,” can be any type of microelectronic device or precursor, meaning a device or precursor containing any of the following: integrated circuits, optical devices, solid-state memory devices, hard disk memory devices, magnetoelectric components, or another type of microdevice or microdevice assembly suitable for electronic, memory, optical, or similar applications and prepared by a manufacturing process comprising one or more of the following steps: chemically mechanically treating the surface of the substrate, often involving multiple steps of depositing and selectively removing combinations of materials at the substrate surface.

[0021] The substrate used in the methods described may comprise any material or combination of materials on its surface that is part of an in-process microelectronic device, including: semiconductor materials (e.g., silicon), ceramics (e.g., silicon carbide, silicon nitride), glass materials, conductive materials (e.g., metals and metal alloys), electrically insulating (dielectric) materials, insulating materials, etc. Conductive materials may be metals or metal alloys including copper, tungsten, silver, aluminum, and cobalt, as well as other metals and their alloys. Electrically insulating dielectric materials may be any of a variety of currently known or under development insulating, low-k, or ultra-low-k dielectric materials, to name just a few examples, including various forms of doped or porous silica, thermal oxides, and TEOS. Examples of substrate materials that may exist in the form of an insulating layer include: tantalum, tantalum nitride, titanium nitride, cobalt, nickel, manganese, ruthenium, ruthenium nitride, ruthenium carbide, or ruthenium tungsten nitride.

[0022] CMP processing involves applying a slurry to a substrate surface and bringing the slurry and substrate into contact with a pad (i.e., a "CMP pad" or "CMP polishing pad"), with movement between the pad and the surface. The slurry contains abrasive particles designed to abrade (mechanically) remove material from the substrate surface. The slurry also typically contains various chemical components dissolved therein, which can effectively control (increase or decrease) the rate of removal of certain materials from the substrate surface; provide the desired selectivity for removing different materials; reduce the presence of defects and the amount of residue on the substrate surface during and after the CMP step; or otherwise promote improvements or desired results related to the efficiency of the CMP process or the quality of the substrate at the end of the CMP process.

[0023] Example slurries (“CMP slurries”) include a liquid carrier, which is primarily composed of water (preferably deionized water) in which chemical materials and abrasive particles are dissolved or dispersed. The chemical materials of the slurry can be selected to achieve the desired removal rate, removal selectivity, and final surface morphology of the finished substrate (e.g., smoothness, waviness, etc.). The specific type and amount of chemical materials in a particular slurry depend on various factors, such as one or more types of materials present on the substrate surface, CMP processing conditions, the type of CMP pad used in the CMP steps, and one or more types of abrasive particles in the slurry. Example chemical compositions include chemical materials that can act as solvents, surfactants, catalysts, stabilizers, oxidizers, organic inhibitors (to control removal rates), chelating agents, etc. Other possible chemical materials include pH adjusters (alkalis, acids), corrosion inhibitors, and biocides (as preservatives).

[0024] Abrasive particles can have size and compositional characteristics to achieve efficient, optionally selective, and uniform removal of specific materials from a substrate surface. Example abrasive particles may be made of or contain alumina, cerium oxide, cerium dioxide, zirconium, zirconia, silica (in various forms), titanium dioxide, zirconium dioxide, diamond, silicon carbide, or other metal, ceramic, or metal oxide materials. These types of abrasive particles, with various sizes, size distributions, particle shapes, and other physical or mechanical properties, are available and can be selected for use with various substrates or CMP processes. The amount of abrasive particles in the slurry can also be selected based on similar factors related to the type of substrate being treated and the characteristics of the CMP process.

[0025] To accommodate different types of substrates, abrasive particles dispersed in a CMP slurry can be selected to exhibit electrostatic charges that can be positive or negative. The charge intensity of the dispersed abrasive particles is commonly referred to as the particle's "zeta potential" (or zeta potential), which is the potential difference between the charge of the ions surrounding the particles and the charge of the bulk liquid in the slurry (e.g., the liquid carrier and any other components dissolved therein). The zeta potential of the dispersed particles typically depends on the pH of the liquid medium in which the particles are dispersed. For a given slurry or other liquid medium, the pH at which the zeta potential of the charged abrasive particles is zero is called the isoelectric point. As the pH of the solution containing the dispersed abrasive particles increases or decreases away from the isoelectric point, the surface charge (and therefore the zeta potential) decreases or increases accordingly (to higher negative or higher positive zeta potential values).

[0026] During the CMP processing steps, the slurry contains various materials, including dissolved and dispersed (e.g., suspended) components of the slurry, as well as other dissolved or dispersed materials generated during the CMP process, such as those removed from the substrate surface. Additional materials present may be derivatives, reaction products, agglomerates, coagulations, and precipitates of any of these materials. Any of the aforementioned materials present in the slurry during the CMP processing steps may become residues remaining on the substrate surface at the end of the CMP processing steps. Therefore, residues on the substrate surface after the CMP steps may include: dissolved chemical materials or solid abrasive particles initially present in the CMP slurry; materials removed from the substrate surface during processing (e.g., metal ions) or materials generated during processing through reactions or chemical modifications (e.g., oxidation or reduction) of the slurry's chemical materials; or combinations of these, including precipitates, agglomerates, and coagulations.

[0027] As is well known, following the CMP treatment step, various CMP post-cleaning steps are suitable for removing residues present on the surface of microelectronic devices. These cleaning steps may involve, and often do involve, the use of specialized CMP post-cleaning equipment, which may include cleaning devices comprising a cleaning chamber in which a cleaning solution is delivered to the substrate surface, and the application of a movable polymer brush to the surface to mechanically remove residues from the substrate surface. Conditions and cleaning time (meaning the amount of time the substrate surface is exposed to the movable brush and cleaning solution) can be selected based on factors such as substrate type, brush type, type and amount of residue at the surface, type of cleaning solution, etc.

[0028] Various CMP post-cleaning tools using polymer brushes are known and commercially available. These devices typically include a cleaning chamber comprising movable cleaning brushes (usually multiple brushes); a source of cleaning solution; a heat source; and systems, mechanisms, and devices, including a control system adapted to contact the cleaning solution with the substrate and the movable brushes under conditions (time and temperature) that effectively allow for the mechanical removal of residues from the surface. Companies that sell such equipment include, in particular: Entegris, Inc.; AION; Ceiba Technologies, Inc.; Rippey Corp.; Applied Materials; and Ebarra.

[0029] Polymer cleaning brushes used in CMP post-cleaning equipment and methods according to this specification comprise polymer surfaces containing hydrogen-bonded groups (e.g., hydroxyl groups (-OH) attached to the polymer backbone). Cleaning brushes comprising polymer surfaces and suitable for CMP post-cleaning treatments are well known. Examples of cleaning brushes containing polymer surfaces with hydroxyl groups attached to the polymer backbone include brushes made of polymers at least partially derived from vinyl alcohol, i.e., polymers of homopolymers or copolymers of vinyl alcohol, such polymers (copolymers and homopolymers) are commonly referred to as polyvinyl alcohol (also known as "PVOH" or "PVA").

[0030] Examples of cleaning brushes for post-CMP cleaning steps are described in U.S. Patent Application 20013 / 0048018, which is incorporated herein by reference in its entirety. As described therein, cleaning brushes can be prepared by using polyvinyl alcohol as a starting material, which can then be treated to form a polyvinyl acetal elastic material. The polyvinyl alcohol starting material can be treated with an aldehyde, such as formaldehyde, to produce a polyvinyl alcohol brush material. Other polymers, substituted for or other than polyvinyl alcohol, are suitable as polymeric materials for the brush and may include hydrogen-bonded groups. Examples of such other polymers include polymers and copolymers of nylon, polyurethane, and combinations thereof, which can form cleaning brushes suitable for removing residues from a substrate in commercial post-CMP cleaning processes, as described herein.

[0031] Example brushes include cylindrical polymer (as described) foam brushes having a first end and a second end, and an outer surface having a plurality of nodules extending from the bottom surface of the brush. The nodules are located along the length of the brush between the first and second ends and are separated from each other by gaps or openings. The nodules can have any shape and typically include a rounded top surface and a surface height extending from the bottom of the brush to the top surface of the nodule. When the brush rotates about an axis extending between the first and second ends, the outer cylindrical surface of the brush rotates, and the nodules on the surface also rotate. A substrate surface having a cleaning solution coated thereon can be brought into contact with the moving surface of the brush and the brush nodules to allow the nodules to contact the surface, facilitating the removal of residue from the surface.

[0032] The cleaning process should be timed and conditions appropriate to effectively remove most of the total amount of residue (e.g., as measured by abrasive particle residue) from the substrate surface in an efficient manner. For example, by using typical CMP post-cleaning equipment and methods, a cleaning solution can be brought into contact with the substrate surface, and the surface will be brought into contact with a polymer brush (with movement between the substrate surface and the brush) for a sufficient time to remove a high percentage of residue (e.g., abrasive particle residue) present on the surface before the cleaning step. Ideally, a suitable CMP post-cleaning step should result in the removal of at least 85% of the residue (e.g., abrasive particle residue) present on the substrate surface before further removal of the residue. More preferably, at least 90%, even more preferably at least 95%, and most preferably at least 99%. Methods and equipment suitable for measuring the amount of residue (e.g., particle residue) remaining on the substrate surface are well known and commercially available.

[0033] To achieve the desired level of residue removal, an example cleaning time for the substrate by the cleaning equipment can be from about 1 second to about 20 minutes, preferably from about 5 seconds to 10 minutes, at a temperature ranging from about 20 degrees Celsius to about 90 degrees Celsius, preferably from about 20 to about 50 degrees Celsius, for example, from about 15 seconds to about 5 minutes. These processing times within these time and temperature ranges are illustrative, and any other suitable time and temperature conditions can be used if CMP residues can be effectively removed at least partially from the substrate surface.

[0034] According to the present invention, the applicant has now clearly confirmed that abrasive particles, especially abrasive particles having hydrogen-bonded groups on the surface of the particles, positive charges (positive ζ potential) in the cleaning solution used in the post-CMP cleaning step, or both, can be attracted by hydrogen-bonded groups present on the polymer surface of the cleaning brush during the post-CMP cleaning step.

[0035] Prior to the post-CMP cleaning step, the microelectronic device substrate may have abrasive particle residue on its surface. During the cleaning step, these abrasive particles are removed (at least largely) from the substrate surface and dispersed in the cleaning solution used for the post-CMP cleaning step. In the cleaning solution, especially under low pH conditions (e.g., below 6 or 7), the dispersed abrasive particles may exhibit a positive charge, i.e., a positive zeta potential. The surface of the abrasive particles may also include hydrogen-bonded groups, such as (-OH) groups, for example, silanol (-SiOH) groups in the case of silica particles. The positively charged particles with hydrogen-bonded groups are electrostatically attracted to the surface of the polymer brush used in the post-CMP cleaning step and can form hydrogen bonds with the hydrogen-bonded groups present there. The abrasive particles can be attracted to the surface of the polymer brush and can accumulate there, and especially in the presence of a cleaning solution with a low pH, the attractive force with the surface can be maintained by hydrogen bonding.

[0036] A potential consequence of the presence and accumulation of abrasive particles on the surface of the cleaning brush during the post-CMP cleaning step is the appearance of brush marks after the CMP cleaning step. Brush marks (or “brush imprints”) are visible patterns of residual abrasive particles remaining on the substrate surface after the CMP cleaning step. These patterns may include shapes or features (e.g., sizes) that match the surface shape or characteristics of the cleaning brush used to clean the substrate surface, such as the circular surface of a cleaning brush nodule. Examples of brush mark patterns formed by residual abrasive particles include circular marks matching the shape and size of the nodule, and line patterns of distinct lines formed by residual abrasive particles, where the length of the lines corresponds to the diameter of the circular brush nodule. Brush marks can be constituted by and formed by patterns of abrasive particles remaining on the substrate after the CMP cleaning step (i.e., abrasive particle residue). The preferred CMP cleaning process described in this specification results in a reduction or minimization, or preferably absence, of brush marks on the substrate surface after the CMP cleaning step.

[0037] According to an example method of the present invention, the post-CMP cleaning step involves an apparatus comprising a scrubbing brush having a polymer surface containing hydrogen-bonded groups. Additionally, the cleaning solution used in the cleaning step may have a low pH, such as below about 7, for example in the range of about 1 to about 5 or 6, or about 1 or 2 to about 3, 3.5 or 4. These factors cause the presence of positively charged abrasive particles (having hydrogen-bonded groups) in the cleaning solution during the post-CMP cleaning step, wherein the positively charged abrasive particles are attracted by the hydrogen-bonded groups at the brush surface, thereby causing the positively charged abrasive particles to be attracted to the polymer brush surface by hydrogen bonding.

[0038] According to the applicant's novelty and the present invention, the cleaning solution and its method of use comprise a dissolved chemical component, referred to as a particle remover, which effectively: prevents the formation of hydrogen bonds between positively charged abrasive particles in the cleaning slurry and the polymer brush surface during a post-CMP cleaning step; inhibits or reduces the formation of hydrogen bonds between the abrasive particles and the polymer brush surface during a post-CMP cleaning step; or removes the abrasive particles attracted to the surface of the polymer brush and having formed hydrogen bonds with the surface (during a post-CMP cleaning step, or in a separate step of cleaning the brush in the absence of a substrate).

[0039] Therefore, the cleaning solution of this specification includes a solution or in solution form, the solution comprising an aqueous medium (preferably deionized water) containing dissolved components, the dissolved components including: a particulate remover, optionally one or more components that act as a cleaning agent (e.g., chelating agents, organic solvents); and optionally, small or trace amounts of other optional adjuvants, such as acids, surfactants, biocides, etc.

[0040] The particulate remover is a chemical compound (including oligomers or polymers) comprising at least one hydrogen-bonded group, and when present in a cleaning solution as described, and in the presence of positively charged abrasive particles and the polymer surface of a cleaning brush, the chemical compound can effectively bind to: the hydrogen-bonded groups on the polymer brush surface, the hydrogen-bonded groups on the positively charged abrasive particles, or both, in a manner and extent that the particulate remover will reduce the amount of abrasive particles present on the cleaning brush surface and attracted to the cleaning brush surface by hydrogen bonding.

[0041] In a cleaning solution containing, for example, positively charged dispersed abrasive particles (carried as residue to the substrate surface) at low pH, the particle removal agent can inhibit or prevent the positively charged particles from binding to the hydrogen-bonded groups of the positively charged particles in a manner that attracts them to the hydrogen-bonded groups present on the surface of the polymer cleaning brush. Additionally, in the presence of a cleaning brush containing hydrogen-bonded groups, and at low pH, the particle removal agent can also inhibit or prevent the cleaning brush from attracting positively charged abrasive particles present in the cleaning solution in a manner associated with the hydrogen-bonded groups present on the cleaning brush surface. More generally, the particle removal agent can prevent or disrupt the hydrogen bonds between the positively charged abrasive particles containing hydrogen-bonded groups and the polymer surface of the cleaning brush containing hydrogen-bonded groups. These effects and interactions (alone or in combination) between the particle removal agent and the cleaning brush surface, and between the particle removal agent and the positively charged abrasive particles present in the cleaning solution (e.g., during a post-CMP cleaning step), effectively reduce the amount of interaction between the hydrogen-bonded groups on the cleaning brush surface and the hydrogen-bonded groups of the positively charged abrasive particles. The result is that fewer abrasive particles will be present on the surface of the cleaning brush and bonded to the surface through hydrogen bonding.

[0042] Therefore, the cleaning solution of the present invention includes a certain amount of particle remover, the amount and type of which can effectively reduce the amount (e.g., concentration) of positively charged abrasive particles present on the polymer surface of the cleaning brush when the abrasive particles are present and the cleaning solution is exposed to the cleaning brush at a low pH.

[0043] Examples of ingredients suitable as particulate removers as described include organic compounds, polymers, oligomers, etc., containing one or more hydrogen-bonded groups (when present in the cleaning solution and at low pH), and which may be included in the cleaning solution to effectively reduce the presence of positively charged abrasive particles on the surface of the polymer cleaning brush as described. Example compounds typically include nitrogen-containing compounds; amino acids; groups containing mono, di, or polycarboxylic acids; alcohols (e.g., polyols); acids, etc.

[0044] Specific examples of particulate removers include nonionic, anionic, cationic, and zwitterionic small molecules, and polymers that can act as polyelectrolytes at neutral pH. Anionic polymers or anionic polyelectrolytes can be natural, modified natural polymers, or synthetic polymers. Exemplary natural and modified natural anionic polymers that may be included in the cleaning solutions described include, but are not limited to: alginic acid (or its salts), carboxymethyl cellulose, dextran sulfate, poly(galacturonic acid), and their salts. Exemplary synthetic anionic polyelectrolytes include, but are not limited to: homopolymers or copolymers of (meth)acrylic acid (or its salts), poly(acrylic acid), maleic acid (or its anhydride), styrene sulfonic acid (or its salts), vinyl sulfonic acid (or its salts), allyl sulfonic acid (or its salts), acryloylaminopropyl sulfonic acid (or its salts), etc., wherein the salts of carboxylic acids and sulfonic acids are preferably neutralized with ammonium or alkylammonium cations. The preferred cation of the polyelectrolyte anionic polymer is an ammonium cation (NH4+). + ), cholinium ions + N(CH3)3(CH2CH2OH) and + N(CH3)4. Therefore, preferred examples of combined synthetic and natural polyelectrolyte anionic polymers are homopolymers or copolymers of (meth)acrylic acid, maleic acid (or anhydride), styrene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, vinyl phosphonic acid, acryloylaminopropyl sulfonic acid, alginic acid, carboxymethyl cellulose, dextran sulfate, poly(galacturonic acid) and its salts.

[0045] The cationic polymers and cationic polyelectrolytes can be natural, modified natural polymers, or synthetic polymers. Exemplary natural and modified natural cationic polymers include, but are not limited to, chitosan, cationic starch, polylysine, and their salts. Exemplary cationic synthetic polyelectrolytes include, but are not limited to, homopolymers or copolymers of: diallyl dimethyl ammonium chloride (DADMAC), diallyl dimethyl ammonium bromide, diallyl dimethyl ammonium sulfate, diallyl dimethyl ammonium phosphate, dimethyl dimethyl ammonium chloride, diethylpropenyl dimethyl ammonium chloride, diallyl di(β-hydroxyethyl) ammonium chloride, diallyl di(β-ethoxyethyl) ammonium chloride, dimethylaminoethyl (meth) acrylate acid addition salts and quaternary salts, diethylaminoethyl (meth) acrylate acid addition salts and quaternary salts, 7-amino-3,7-dimethyloctyl (meth) acrylate acid addition salts and quaternary salts, N,N'-dimethylaminopropylacrylamide acid addition salts and quaternary salts, wherein the quaternary salts include alkyl and benzyl quaternary salts; allylamine; diallylamine; ethyleneamine (obtained by hydrolysis of vinylalkylamide polymers); vinylpyridine; chitosan; cationic starch; polylysine and its salts.

[0046] Other examples include 2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone (HEP), glycerol, 1,4-butanediol, butylene sulfone (sulfolane), dimethyl sulfone, ethylene glycol, propylene glycol, dipropylene glycol, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, glycol ethers (e.g., diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether). DEGBE, triethylene glycol monobutyl ether (TEGBE), ethylene glycol monohexyl ether (EGHE), diethylene glycol monohexyl ether (DEGHE), ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPGME), tripropylene glycol methyl ether (TPGME), dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether (DOWANOL PnB), dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether (DOWANOL PPh), n-ethylpyrrolidone, n-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, and combinations thereof. Alternatively, or additionally, cleaning additives may include hydroxypropyl cellulose; hydroxyethyl cellulose; hydroxyethyl methyl cellulose; hydroxypropyl methyl cellulose; carboxymethyl cellulose; sodium carboxymethyl cellulose (Na CMC); polyvinylpyrrolidone (PVP); any polymer made using N-vinylpyrrolidone monomers, polyacrylates, and polyacrylate analogs; polyamino acids (e.g., polyalanine, polyleucine, polyglycine); polyamide hydroxycarbamates; polylactones; polyacrylamide; succinate; chitosan; polyethylene oxide; polyvinyl alcohol (PVA); polyvinyl acetate; polyacrylic acid; polyethyleneimine (PEI); sugar alcohols such as sorbitol, sucrose, fructose, and lactose. Galactose, maltose, erythritol, maltitol, threitol, arabinol, ribitol, mannitol, galactitol, inositol, and xylitol; esters of desorbitol; secondary alcohol ethoxylates, such as TERGITOL; multifunctional alcohols, including pentaerythritol, dipentaerythitol, trimethylolpropane, dimethylpropionic acid, and xylic acid; nucleobases, such as uracil, cytosine, guanine, thymine, and combinations thereof.

[0047] Other examples include lactic acid, maleic acid, urea, glycolic acid, sorbitol, borax (i.e., sodium borate), proline, betaine, glycine, histidine, tris(hydroxymethyl)aminomethane (TRIS), dimethyl sulfoxide, sulfolane, glycerol, SDS (sodium dodecyl sulfate), dodecylphosphonic acid, or combinations thereof. Among these, certain particulate removers are preferably used in the post-CMP cleaning step of microelectronic device substrates, such as maleic acid, borax (i.e., sodium borate), dimethyl sulfoxide, glycerol, or combinations thereof.

[0048] According to certain example cleaning solutions, the total amount of one or more particulate removers in the cleaning solution during use (during post-CMP cleaning) may be at least about 0.01% by weight, more preferably at least about 0.02% by weight, such as at least 0.05% by weight, based on the total weight of the cleaning solution. Example amounts may be at most about 1% by weight, more preferably at most about 0.3% by weight, such as at most about 0.2% by weight of particulate removers, based on the total weight of the cleaning solution.

[0049] According to certain example cleaning solutions in concentrated form before being diluted into a point-of-use composition, the total amount of one or more particulate removers in the cleaning solution concentrate may be at least about 7% by weight of the total cleaning solution, such as at least about 10% by weight, but not more than 20% by weight of the total cleaning solution, preferably not more than 8% by weight, for example, not more than 7% by weight of particulate removers.

[0050] In addition to particulate removers, the cleaning compositions described may preferably include one or more other dissolved chemical components, which, for example, act as cleaning agents during the post-CMP cleaning step to help remove residues from the substrate surface. One or more cleaning agents may function through various known cleaning or isolating mechanisms, such as by dissolving residues as organic materials, by dispersing solid or particulate residues, or by otherwise interacting with or separating residues present on the substrate surface after the CMP step, or present in the cleaning solution used to clean the substrate during the post-CMP cleaning step.

[0051] Examples of suitable organic solvents used in CMP post-cleaning solutions and methods are known. Example solvents may particularly be polar organic solvents, alcohols, glycols, and amines. Non-limiting examples include lower molecular weight alcohols (such as C1 to C4 alkyl alcohols), alkylene glycols, ethanolamines (e.g., monoethanolamine), N,N'-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone, etc.

[0052] Illustrative examples of organic amines include those with the general formula NR. 1 R 2 R 3 The types, of which R 1 R 2 and R 3 They may be the same as or different from each other, and are selected from the group consisting of: hydrogen, straight-chain or branched C1-C6 alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl), straight-chain or branched C1-C6 alcohols (e.g., methanol, ethanol, propanol, butanol, pentanol, and hexanol), and those having the formula R. 4 -OR 5 Straight-chain or branched-chain ethers, wherein R 4 and R 5They may be the same as or different from each other, and are selected from the group consisting of C1-C6 alkyl groups as defined above. When the amine includes an ether component, the amine may be considered an alkoxyamine. Most preferably, R 1 R 2 and R 3 At least one of them is a straight-chain or branched-chain C1-C6 alcohol. Examples include, but are not limited to, alkanolamines such as aminoethylethanolamine, N-methylaminoethanol, aminoethoxyethanol, dimethylaminoethoxyethanol, diethanolamine, N-methyldiethanolamine, monoethanolamine, triethanolamine, 1-amino-2-propanol, 3-amino-1-propanol, diisopropylamine, isopropylamine, 2-amino-1-butanol, isobutanolamine, diisopropanolamine, tris(hydroxymethyl)aminomethane (TRIS), tris(hydroxyethyl)aminomethane, other C1-C8 alkanolamines and combinations thereof; amines such as triethylenediamine, ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylamine, trimethylamine and combinations thereof; diethylene glycolamine; morpholine; and combinations of amines and alkanolamines. Preferably, the organic amine comprises monoethanolamine.

[0053] Generally, organic solvents can be included in the cleaning solution in a useful amount, said amount being effective as a cleaning agent in the manner described herein, for example, by dissolving organic residues. The specific type and amount of organic solvent included in a given cleaning solution can be selected based on factors including: the type of substrate being cleaned, the type and amount of residue present on the substrate surface, other components in the cleaning solution, and the conditions (time, temperature, etc.) used in the post-CMP cleaning process.

[0054] According to certain example cleaning solutions, when used (during post-CMP cleaning), the total amount of one or more organic solvents in the cleaning solution may be less than about 1 wt%, more preferably less than about 0.33 wt%, and most preferably not more than 0.13 wt%, for example, not more than 0.067 wt% or not more than 0.033 wt% of the total weight of the cleaning solution. Preferably, if present, the amount of organic solvent may be at least 0.0003 wt%, more preferably at least 0.001 wt%, for example, at least 0.015 or 0.025 wt% of the total weight of the cleaning solution.

[0055] According to certain example cleaning solutions in concentrated form before dilution into a point-of-use composition, the total amount of one or more organic solvents in the cleaning solution concentrate may be no more than 20% by weight, more preferably no more than 10% by weight, most preferably no more than 7% by weight, for example no more than 2% by weight, or no more than 1% by weight, based on the total weight of the cleaning solution. Preferably, if present, the applicable amount may be at least 0.005% by weight, more preferably at least 0.01% by weight, such as at least 0.05% by weight or at least 0.2 or 0.35% by weight, based on the total weight of the cleaning solution.

[0056] The cleaning solution may optionally contain at least one chelating agent. Generally, the chelating agent used in post-CMP cleaning compositions is a compound that typically forms a complex molecule with metal ions, usually iron ions, to deactivate the ions in the cleaning solution and prevent chemical reactions or activity by said ions. Various chelating agents are known to be used in post-CMP cleaning compositions and can be used in the cleaning compositions and methods described in this specification. Some specific examples include acid-containing organic molecules, especially carboxylic acid-containing organic molecules, such as straight-chain or branched C1-C6 carboxylic acid compounds, including phthalic acid, succinic acid, citric acid, tartaric acid, malic acid, gluconic acid, aspartic acid or combinations thereof, and glycine, amino acids, etc. Citric acid can be used to chelate iron ions (e.g., Fe). +2 Fe +3 Preferred chelating agents for metal ions include sugar alcohols such as arabinitol, erythritol, glycerol, hydrogenated starch hydrolysate (HSH), isomalt, lactitol, maltitol, mannitol, sorbitol, and xylitol.

[0057] Other metal chelating agents covered in this article include, but are not limited to, acetic acid, acetone oxime, acrylic acid, adipic acid, alanine, arginine, asparagine, aspartic acid, betaine, dimethylglyoxime, formic acid, fumaric acid, gluconic acid, glutamic acid, glutamine, glutamate, glyceric acid, glycerol, glycolic acid, glyoxylic acid, histidine, iminodiacetic acid, isophthalic acid, itaconic acid, lactic acid, leucine, lysine, maleic acid, maleic anhydride, malic acid, malonic acid, mandelic acid, 2,4-pentanedione, phenylacetic acid, phenylalanine, phthalic acid, proline, propionic acid, catechol, pyromellitic acid, quinic acid, serine, sorbitol, succinic acid, tartaric acid, terephthalic acid, trimellitic acid, and trimesic acid. (acid), tyrosine, valine, xylitol, ethylenediamine, oxalic acid, tannic acid, pyridinecarboxylic acid, 1,3-cyclopentanedione, catechol, gallol, resorcinol, hydroquinone, cyanuric acid, barbituric acid, 1,2-dimethylbarbituric acid, pyruvic acid, propanethiol, benzoyl hydroxyxamic acid, tetraethylenepentamine (TEPA), 4-(2-hydroxyethyl)morpholine (HEM), N-aminoethylpiperazine (N-AEP), ethylenediaminetetraacetic acid (EDTA), 1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid (CDTA), N-(hydroxyethyl)-ethylenediaminetetraacetic acid (HEdTA), iminodiacetic acid (IDA), 2-(hydroxyethyl)iminodiacetic acid (HIDA), azotriacetic acid, aminotris(methylene phosphate), hydroxyethylidine diphosphonic acid, ethylenediaminotetra(methylene phosphate), ethylenediaminopenta(methylene phosphate), thiourea, 1,1,3,3-tetramethylurea, urea, urea derivatives, glycine, cysteine, glutamic acid, isoleucine, methionine, piperidine, N-(2-aminoethyl)piperidine, pyrrolidine, threonine, tryptophan, salicylic acid, dipyridinecarboxylic acid, p-toluenesulfonic acid, 5-sulfosalicylic acid and combinations thereof.

[0058] Other examples of suitable chelating agents include carboxylic acid-containing oligomers and polymers derived from monomers, said monomers may include one or more of the following: acrylic acid, methacrylic acid, maleic acid, succinic acid, aspartic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, acrylamide, phosphonomethacrylamidopropyltrimethylammonium chloride, allyl halides, or combinations thereof. Polyacrylic acid may be a preferred chelating agent for chelating silicon nitride (SiN). Further examples include: propane-1,2,3-tricarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, pentane-1,2,3,4,5-pentacarboxylic acid, trimellitic acid, trimesinic acid, pyrocalcite, benzenehexacarboxylic acid, and combinations thereof.

[0059] Generally, chelating agents can be included in a useful amount in the cleaning solution, and said amount can be effective in the manner described herein with respect to chelating agents. The specific type and amount of chelating agent included in a given cleaning solution can be selected based on factors including: the type of substrate being cleaned, the type of residue present on the substrate surface, other components in the cleaning solution, and the conditions of the post-CMP cleaning process.

[0060] According to certain example cleaning solutions, when used (during post-CMP cleaning treatment), the total amount of one or more chelating agents in the cleaning solution may be up to about 5% by weight, such as up to about 2% by weight, and most preferably up to about 1% by weight. Preferably, if present, the amount may be at least 0.0005% by weight, more preferably at least 0.001% by weight, such as at least 0.007% by weight, based on the total weight of the cleaning solution.

[0061] According to certain example cleaning solutions in concentrated form before dilution into a point-of-use composition, the total amount of one or more chelating agents in the cleaning solution concentrate may be no more than 20% by weight, more preferably no more than 13% by weight, and most preferably no more than 10% or 7% by weight, for example, no more than 3% by weight, or no more than 1.5% by weight, based on the total weight of the cleaning solution. Preferably, the amount may be at least 0.008% by weight, more preferably at least 0.015% by weight, such as at least 0.1% by weight or at least 0.3% by weight, based on the total weight of the cleaning solution.

[0062] The cleaning solution may optionally contain other ingredients or adjuvants to improve the cleaning effect or efficiency of the post-CMP cleaning step using the cleaning solution. Optionally, for example, the cleaning solution may include a pH adjuster or buffer system to control the pH of the cleaning solution concentrate or the point-of-use composition. Examples of suitable pH adjusters include organic and inorganic acids that effectively lower pH, such as nitric acid, sulfuric acid, phosphoric acid, phthalic acid, citric acid, adipic acid, oxalic acid, methanesulfonic acid, hydrochloric acid, malonic acid, maleic acid, etc. Other optional ingredients include surfactants (of any type) or biocides.

[0063] According to this specification, a post-CMP cleaning method, as described, is applicable to cleaning substrates after a CMP step, except that the cleaning solution of the comparable cleaning method does not contain the particulate remover (including the amount thereof) as described herein. This is applicable to cleaning substrates after a CMP step, with the cleaning solution containing the particulate remover as described herein, in a manner that preferably and advantageously reduces the occurrence of brush marks on the substrate surface at the end of the post-CMP cleaning step, compared to a otherwise identical post-CMP cleaning method performed on the same substrate (with the same or comparable residue) using a cleaning solution that is otherwise identical but does not contain the particulate remover.

[0064] Also according to this specification, compared to a comparable cleaning method performed in the same manner (using the same cleaning equipment, brush, cleaning solution volume, cleaning time, cleaning temperature, etc.) on the same substrate (with comparable residue), except that the cleaning solution of the comparable cleaning method does not contain a particulate remover (e.g., in the amount described herein), a post-CMP cleaning method having a cleaning solution as described, wherein the cleaning solution contains a particulate remover as described (including the amount described), will result in a reduction in the amount of abrasive particles present on the surface of the polymer cleaning brush during or at the end of the cleaning step. According to embodiments of the post-CMP substrate cleaning method of this specification, compared to a otherwise identical post-CMP cleaning method performed on the same substrate using a cleaning solution that is otherwise identical but does not contain a particulate remover, using a cleaning solution as described can reduce the presence of abrasive particles present (e.g., attracted by hydrogen bonding) on ​​the surface of the polymer cleaning brush during or at the end of the post-CMP cleaning process (e.g., a reduction of at least 50%, 75%, 90%, 95%, or 99%).

[0065] Example cleaning solutions are suitable for removing residues present on the substrate surface, or reducing the presence (i.e., removal) or accumulation of abrasive particles on the polymer surface of a cleaning brush. In treating a substrate or brush for any of these purposes, the cleaning solution is not intended to be a cleaning solution or for removing (as described herein) materials constituting the substrate surface layer. Therefore, the cleaning solutions described do not require and preferably may not include any large quantities of applicable chemical or abrasive materials that have the effect of removing material from the substrate surface, including abrasive particles, oxidants, surfactants, catalysts, etc., typically present in CMP slurries designed for use in CMP processes to remove material from the substrate surface.

[0066] The cleaning solution described herein (in its initial form prior to use in the methods described herein) may not contain abrasive particles of the type that may be present in the CMP processing steps. These are solid particles (e.g., nanoparticles) present in the CMP slurry intended for use to mechanically remove material from the substrate surface during the CMP processing steps. Examples include silica particles, cerium oxide particles, zirconium oxide, alumina particles, and other metal and metal oxide abrasive particles present in the slurry in solid (non-dissolved) form. The cleaning solution of this specification (in its initial form prior to use in the cleaning steps) may contain no more than 1, 0.1, 0.01, 0.001, or 0.0001% by weight of solid abrasive particles based on the total weight of the cleaning solution. These amounts represent the cleaning solution and concentrate composition as used.

[0067] Similarly, the preferred cleaning solutions described do not require and may optionally exclude chemical materials that function by chemically interacting with the material constituting the surface layer of the CMP substrate or with another material of the slurry, in order to effectively remove the surface layer material from the substrate surface. Examples of such chemical materials include surfactants, catalysts (e.g., metal ion catalysts, especially iron ion catalysts), and oxidants, etc. An example cleaning solution may contain no more than 1, 0.1, 0.01, 0.001, or 0.0001% by weight of any one or a combination of surfactants, catalysts, or oxidants, based on the total weight of the cleaning solution. These amounts represent the cleaning solution and concentrate composition as used.

[0068] For the purpose of removing catalysts, oxidants, and surfactants as components from cleaning solutions as described, a "surfactant" is an organic compound that reduces the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. It is typically an amphiphilic organic compound containing both a hydrophobic group (e.g., a hydrocarbon "tail") and a hydrophilic group. Surfactants can have any HLB (hydrophilic-lipophilic balance) value and can be charged, uncharged, etc. Many diverse examples of surfactants are well-known in the fields of chemistry and CMP.

[0069] A "catalyst" is a material that, especially in the presence of an oxidant, can effectively provide metal ions to a solution (e.g., a liquid carrier of a CMP slurry). It is capable of reversibly oxidizing and reducing metal materials, particularly those removed from the substrate surface during the CMP processing steps using the slurry, where the metal ions of the catalyst facilitate removal. Examples of metal ion catalysts are well known in the CMP field and can provide metal ions to the slurry, such as ions of iron, cobalt, copper, europium, manganese, tungsten, molybdenum, rhenium, or iridium. Examples of iron ion catalysts are soluble in a liquid carrier and may include iron (iron III) or ferrous (iron II) compounds, such as ferric nitrate, ferric sulfate, ferric halides (including ferric fluoride, ferric chloride, ferric bromide, and ferric iodide, as well as ferric perchlorate, ferric perbromate, and ferric periodate), and organoferric compounds, such as ferric acetate, ferric acetylacetonate, ferric citrate, ferric gluconate, ferric malonate, ferric oxalate, ferric phthalate, and ferric succinate, and mixtures thereof.

[0070] Oxidizing agents are compounds that include, or include, inorganic or organic peroxides. Peroxides can be understood as compounds containing at least one peroxy group (-OO-), or compounds containing an element in its highest oxidation state. Examples of compounds containing at least one peroxy group include hydrogen peroxide and its adducts, such as urea peroxide and percarbonates; organic peroxides, such as benzoyl peroxide, peracetic acid, and di-tert-butyl peroxide; and monoperoxide sulfate (SO₅₅). ＝ ); Dispersulfate (S2O8) ＝ And sodium peroxide. Examples of compounds containing elements in their highest oxidation state include periodic acid, periodate, perbromic acid, perbromate, perchloric acid, perchlorate, perboric acid, perborate, and permanganate. Hydrogen peroxide is generally the preferred oxidant for CMP slurries.

[0071] In use, the cleaning composition as described and in concentrated form can be diluted to form a cleaning solution for use in post-CMP cleaning steps. The concentrate may include the chemical components as described, in amounts that, upon dilution, will provide a point-of-use composition with the desired concentration of each component. The pH of the concentrate may be lower than the pH of the composition used; for example, the pH of the concentrate may be lower than 2.5 or lower than 2. The amount of water added to the concentrate to form the composition used, i.e., the dilution ratio, may be determined as needed. Example concentrates can be diluted using factors of 10, 50, 100, or 200, for example, by combining a certain volume of concentrate with a volume of water that is 10, 50, 100, or 200 times the volume of said concentrate.

[0072] According to various examples of methods using the cleaning solution as described, microelectronic device substrates can be cleaned, for example, using a post-CMP cleaning apparatus, in a post-CMP cleaning step to remove residues, including abrasive particle residues, from the substrate surface. The substrate may be a microelectronic device substrate, generally a planar wafer that may include a substrate having a material selectively deposited on and selectively removed from the substrate to produce a microelectronic feature layer including a surface layer. The surface layer may be made of the deposited material, which includes one or more metals (e.g., copper, tungsten, silver, cobalt, nickel, etc.), insulating or dielectric materials (e.g., TEOS, silicon nitride), and semiconductor materials. Residues as described, including abrasive particles used in the CMP step, may be present on, but not in, portions of, the deposited material constituting the substrate surface layer.

[0073] Specific examples of substrates with residues are post-CMP microelectronic device substrates containing metallic features (e.g., tungsten, copper, or cobalt in the form of pads or interconnects (e.g., plugs)) and one or more non-metallic materials, such as dielectric materials or insulating layers (e.g., TEOS, silicon nitride, etc.), at their surfaces. The substrate contains residues at its surface, such as abrasive particles. These abrasive particles can be of any suitable type, such as alumina, silica, cerium oxide, zirconium oxide, or related oxides. The abrasive particles will typically be of a type suitable for processing a specific type of wafer and the material on the wafer surface. For example, a substrate including tungsten features and dielectric material at its surface can be pre-treated using a CMP step that includes silica abrasive particles.

[0074] According to the cleaning steps, the CMP substrate with residue on its surface is brought into contact with a polymer cleaning brush, and a cleaning solution as described is dispensed onto the cleaning brush and the substrate surface. Relative motion between the brush and the substrate surface is provided at the required pressure. The post-CMP cleaning step effectively reduces the amount of residue, including abrasive particles, present on the substrate surface after the CMP step.

[0075] Example

[0076] Table 1 lists examples illustrating the concepts of the invention described herein, as well as comparative examples:

[0077] Table 1

[0078]

[0079] PETEOS wafers were polished on IC 1010 pads using a colloidal silica-based CMP slurry and cleaned with five formulations of different pH values: control, pH 6; cleaners 1, 2, and 3 (pH = 2); and commercial dAmmonia, pH 10. Polishing was performed on an AMAT Reflexion LK polishing tool, and defect inspection was performed on a KLAT SP-3 tool with defect sizes ≥0.1 / 0.065 / 0.060 μm and a KLAT eDR-7100 defect inspection tool (microscope, SEM, EDX).

[0080] Without a mega-sonic step, cleaning is performed using an Integ brush (PVP1ARXR1).

[0081] Figure 1 Defect data are shown on PETEOS wafers cleaned at pH < 6 and pH > 6, where brush marks were detected only at pH ~ 2 when cleaning agents 1, 2 and 3 were used.

[0082] Figure 2The mechanism of brush printing based on silica brush hydrogen bonding is shown at low pH.

[0083] Brushes loaded with silica can also be detected using FTIR spectroscopy, where a clear distinction can be made at approximately 1100 cm⁻¹. -1 The silica Si-O-Si peak at approximately 10¹⁶ cm⁻¹ -1 The characteristic peak of the brush (COC) Figure 3 ).

[0084] Table 2 presents a list of H-bonded silica brush cleaning additives used in this experiment:

[0085] Table 2

[0086] Mixtures additive 1 Glycerol + K2S2O5 4 Glycerol + Formic Acid 8 Glycerol + 3 MPa 13 Glycerol + Urea 15 Glycerol + DMSO 16 Glycerol + Oxalic Acid 18 maleic acid 19 glycolic acid 20 Sorbitol 21 Sulfolane

[0087] Figure 4 The following are FTIR spectra of silica-contaminated brushes cleaned with pH 2 formulations containing these additives:

[0088] Figure 5 The defect rate on PETEOS wafers is shown in a direct comparative form, presenting the present invention (using abundant silica-H-bonding additives or brush-H-bonding additives) and a comparative example without these additives.

Claims

1. A method for removing abrasive particles from a cleaning brush after chemical mechanical treatment (CMP), the method comprising: A CMP post-cleaning brush is provided having a polymer surface with abrasive particle residue on the polymer surface, wherein the polymer surface comprises a polymer containing hydrogen-bonded groups, and wherein the hydrogen-bonded groups are: alcohol, phosphine, phosphate ester, phosphonate, alkanolamine, carbamate, urea, carbamate, ester, betaine, silanol, or sulfur-containing groups. A cleaning solution with a pH of 1 to 3.5 is provided, the cleaning solution comprising: The cleaning agent comprises an organic solvent and a chelating agent, wherein, based on the total weight of the cleaning solution, the organic solvent is at least 0.35% by weight and not more than 7% by weight, and the chelating agent is at least 0.3% by weight and not more than 7% by weight, wherein the organic solvent is selected from the group consisting of C1 to C4 alkyl alcohols, alkylene glycols, ethanolamines, N,N'-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and N-ethylpyrrolidone, and wherein the chelating agent is selected from the group consisting of phthalic acid, succinic acid, citric acid, tartaric acid, malic acid, gluconic acid, and amino acids. The cleaning solution contains at least 0.01% by weight and no more than 8% by weight of a particulate remover, the particulate remover comprising one or more hydrogen-bonded groups, the particulate remover being selected from the group consisting of sugar alcohols, poly(acrylic acid), glycerol, and polydextrose. Abrasive particle residues are removed from the polymer surface by bringing the polymer surface into contact with the cleaning solution.

2. A method for cleaning a substrate after chemical mechanical treatment (CMP), the method comprising: A post-CMP cleaning brush is provided, wherein the polymer surface comprises a polymer containing hydrogen-bonded groups, and wherein the hydrogen-bonded groups are: alcohol, phosphine, phosphate ester, phosphonate, alkanolamine, carbamate, urea, carbamate, ester, betaine, silanol, or sulfur-containing groups. A cleaning solution with a pH of 1 to 3.5 is provided, comprising: The cleaning agent comprises an organic solvent and a chelating agent, wherein, based on the total weight of the cleaning solution, the organic solvent is at least 0.35% by weight and not more than 7% by weight, and the chelating agent is at least 0.3% by weight and not more than 7% by weight, wherein the organic solvent is selected from the group consisting of C1 to C4 alkyl alcohols, alkylene glycols, ethanolamines, N,N'-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and N-ethylpyrrolidone, and wherein the chelating agent is selected from the group consisting of phthalic acid, succinic acid, citric acid, tartaric acid, malic acid, gluconic acid, and amino acids. The cleaning solution contains at least 0.01% by weight and no more than 8% by weight of a particulate remover, the particulate remover comprising one or more hydrogen-bonded groups, and the particulate remover being selected from the group consisting of sugar alcohols, poly(acrylic acid), glycerol, and polydextrose. A substrate is provided comprising a surface having residue at the surface of the substrate, the residue comprising abrasive particles, and Residues are removed from the substrate surface by exposing the substrate surface and the polymer surface to the cleaning solution, while simultaneously bringing the substrate surface into contact with the polymer surface and moving the substrate surface relative to the polymer surface.

3. The method according to claim 1, wherein the abrasive particles are selected from: silica particles, cerium clay particles, cerium dioxide particles, alumina particles, titanium dioxide, zirconium oxide, diamond or silicon carbide particles or combinations thereof.

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