Self-stopping polishing compositions and methods for high topography selectivity

Abstract

The invention provides a chemical mechanical polishing composition comprising: (a) an abrasive selected from ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stoppage agent selected from compounds of Formula (I); (c) optionally, a non-ionic polymer; (d) a cationic monomeric compound; and (e) water, wherein the pH of the polishing composition is from about 5.5 to about 8. The invention also provides a method of chemically mechanically polishing a substrate, especially a substrate comprising silicon oxide and optionally polysilicon, using the composition.

Description

BACKGROUND

[0001] In the fabrication of integrated circuits and other electronic devices, multiple layers of conductive, semiconductive, and dielectric materials are deposited onto or removed from a substrate surface. As layers of material are sequentially deposited onto and removed from the substrate, the topmost surface of the substrate can become non-planar and needs to be planarized. Planarizing or "polishing" a surface is a process in which material is removed from the surface of the substrate to form a substantially uniform, planar surface. Planarization can be used to remove undesirable surface topography and surface defects such as rough surfaces, agglomerated materials, lattice damage, scratches, and contaminated layers or materials. Planarization can also be used to form features on a substrate by removing excess deposited material used to fill the features, and to provide a uniform surface for subsequent metallization and processing.

[0002] Compositions and methods for planarizing or polishing a substrate surface are well known in the art. Chemical mechanical planarization or chemical mechanical polishing (CMP) is a common technique used to planarize a substrate. CMP utilizes a chemical composition, referred to as a CMP composition or more simply as a polishing composition (also referred to as a polishing slurry), to selectively remove material from a substrate. The polishing composition is typically applied to the substrate by contacting the substrate surface with a polishing pad (e.g., a polishing cloth or a polishing disk) saturated with the polishing composition. The polishing of the substrate is further aided by the chemical activity of the polishing composition and / or the mechanical activity of an abrasive suspended in the polishing composition or incorporated into the polishing pad (e.g., a fixed abrasive polishing pad).

[0003] As the size of integrated circuits decreases and the number of integrated circuits on a chip increases, the components making up the circuits must be placed closer together in order to fit within the limited space available on a typical chip. Effective isolation between circuits is important to ensure optimal semiconductor performance. To this end, shallow trenches are etched into the semiconductor substrate and filled with insulating material to isolate the active regions of the integrated circuits. More specifically, shallow trench isolation (STI) is a process in which a silicon nitride layer is formed on a silicon substrate, a shallow trench is formed via etching or photolithography, and a dielectric layer is deposited to fill the trench. Due to variations in the depth of the trenches formed in this manner, it is typically necessary to deposit an excess of dielectric material on top of the substrate to ensure complete filling of all trenches. The dielectric material (e.g., silicon oxide) conforms to the underlying topography of the substrate.

[0004] Accordingly, after the dielectric material has been disposed, the surface of the deposited dielectric material is characterized by an uneven combination of raised regions of dielectric material separated by trenches in the dielectric material, the raised regions of dielectric material and trenches aligned with corresponding raised regions and trenches of the underlying surface. The region of the substrate surface comprising the raised dielectric material and trenches is referred to as a patterned field of the substrate, e.g., as "patterned material," "patterned oxide," or "patterned dielectric." The patterned field is characterized by a "step height," which is the difference in height of the raised regions of dielectric material relative to the height of the trenches.

[0005] The excess dielectric material is typically removed by a CMP process, which additionally provides a planar surface for further processing. During removal of the raised region material, an amount of material is also removed from the trenches. This removal of material from the trenches is referred to as "trench erosion" or "trench loss." Trench loss is the amount (thickness, e.g., in Angstroms units) of material removed from the trenches in achieving planarization of the patterned dielectric material by eliminating the initial step height. Trench loss is calculated as the initial trench thickness minus the final trench thickness. Desirably, the rate of material removal from the trenches is much lower than the rate of material removal from the raised regions. Accordingly, as the material of the raised regions is removed (at a faster rate than material is removed from the trenches), the patterned dielectric becomes a highly planarized surface, which can be referred to as a "blanket" region of the processed substrate surface, e.g., a "blanket dielectric" or "blanket oxide."

[0006] A polishing composition can be characterized according to its polishing rate (i.e., removal rate) and its planarization efficiency. Polishing rate refers to the rate of material removal from a substrate surface and is typically expressed in units of length (thickness, e.g., in Angstroms Different removal rates associated with different areas of the substrate or with different stages of the polishing step can be important in assessing the effectiveness of the process. The "pattern removal rate" or "active removal rate" is the rate at which dielectric material is removed from the raised areas of the patterned dielectric layer at a stage of the process where the substrate exhibits a substantial step height. The "blanket removal rate" refers to the rate at which dielectric material is removed from the planarized (i.e., "blanket") areas of the patterned dielectric layer at the end of the polishing step, when the step height has been substantially (e.g., substantially completely) reduced. Planarization efficiency is related to the reduction in step height and the amount of material removed from the substrate (i.e., the reduction in step height divided by the trench loss). Specifically, the polishing surface (e.g., polishing pad) first contacts the "high points" of the surface and must remove material in order to form a planar surface. A process that achieves a planar surface with less material removal is considered more efficient than a process that requires more material removal to achieve planarity.

[0007] Often, for dielectric polishing steps in an STI process, the removal rate of the silicon oxide patterned material can be rate limiting, and thus a high silicon oxide pattern removal rate is desired to increase device productivity. However, if the blanket removal rate is too fast, overpolishing of the oxide in the exposed trench results in trench erosion and increased device defectivity. If the blanket removal rate is decreased, overpolishing and associated trench loss can be avoided.

[0008] In certain polishing applications, it is desirable for the CMP composition to exhibit a "self-stopping" behavior, such that the removal rate decreases when the majority of the "high points" (i.e., raised areas) of the surface have been removed. In a self-stopping polishing application, the removal rate is high when there is a substantial step height at the surface of the substrate, and then decreases as the surface becomes substantially planar. In various dielectric polishing steps (e.g., in various dielectric polishing steps of an STI process), the removal rate of the patterned dielectric material (e.g., dielectric layer) is typically the rate limiting factor for the overall process. Thus, a high patterned dielectric material removal rate is desired to increase productivity. Good efficiency in the form of relatively low trench loss is also desired. Furthermore, if the removal rate of the dielectric is still high after planarization is achieved, overpolishing occurs, resulting in additional trench loss.

[0009] Thus, there remains a need for self-stopping CMP compositions and chemical mechanical polishing methods that can exhibit a "self-stopping" behavior, such that the removal rate decreases when the majority of the "high points" (i.e., raised areas) of the surface have been removed, and that can remain stable when exposed to polishing conditions.

[0010] The present invention provides such polishing compositions and methods. These and other advantages of the invention, as well as additional features of the invention, will be apparent from the description of the invention provided herein. SUMMARY

[0011] The present invention provides a chemical mechanical polishing composition comprising, consisting essentially of, or consisting of: (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stopping agent selected from the group consisting of compounds of Formula (I):

[0012]

[0013] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) a cationic monomer compound; and (d) water, wherein the pH of the polishing composition is from about 5.5 to about 8.

[0014] The present invention further provides a method of chemically mechanically polishing a substrate comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical mechanical polishing composition comprising: (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stopping agent selected from the group consisting of compounds of Formula (I):

[0015]

[0016] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) a cationic monomer compound; and (d) water, wherein the pH of the polishing composition is from about 5.5 to about 8; (iv) contacting the substrate with the polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate, thereby polishing the substrate. DETAILED DESCRIPTION

[0017] The present invention provides a chemical mechanical polishing composition comprising, consisting essentially of, or consisting of: (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stopping agent selected from the group consisting of compounds of Formula (I):

[0018]

[0019] wherein R is selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) an optional nonionic polymer; (d) a cationic monomer compound; and (e) water, wherein the pH of the polishing composition is from about 5.5 to about 8.

[0020] The chemical mechanical polishing composition of the present application comprises an abrasive. The abrasive of the polishing composition desirably is suitable for polishing non-metallic portions of a substrate (e.g., patterned dielectric material, blanket dielectric material, patterned oxide material, blanket oxide material, etc.). Suitable abrasives include ceria abrasive (e.g., Ce02), zirconia abrasive (e.g., Zr02), and combinations thereof.

[0021] Both ceria abrasives and zirconia abrasives are well known in the CMP art and are commercially available. Examples of suitable ceria abrasives include wet ceria, calcined ceria, and metal-doped ceria, among others. Examples of suitable zirconia abrasives include metal-doped zirconia and non-metal-doped zirconia, among others. Metal-doped zirconia includes zirconia doped with elements whose weight percentage is preferably in the range of 0.1% to 25% of cerium, calcium, magnesium, or yttrium.

[0022] In some embodiments, the chemical mechanical polishing composition comprises a ceria abrasive. As used herein, the term "ceria abrasive" can be used interchangeably with "ceria abrasive particles," "ceria particles," or "abrasive." Ceria is well known to be an oxide of the rare earth metal cerium, and is also known as ceric oxide, oxide of cerium (e.g., oxide of cerium (IV)), or dioxide of cerium. The oxide of cerium (IV) (Ce02) can be formed by calcining cerium oxalate or cerium hydroxide. Cerium also forms oxide of cerium (III), such as Ce203. Ceria abrasive particles can comprise any one or more of these or other oxides of ceria.

[0023] The ceria abrasive particles can be of any suitable type. In embodiments, the ceria abrasive particles comprise, consist essentially of, or consist of calcined ceria particles, wet ceria particles, wet-process based ceria particles, or a combination thereof. Ceria abrasives suitable for use in the polishing compositions of the present application and methods of making the same are described in U.S. Patent Application Serial No. 14 / 639,564, filed March 5, 2015, entitled “Polishing Composition Containing Ceria Abrasive” (now U.S. Patent No. 9,505,952); and U.S. Patent Application Serial No. 15 / 207,973, filed July 12, 2016, entitled “Methods and Compositions for Processing Dielectric Substrate” (published as U.S. Patent Application Publication No. 2017 / 0014969), the disclosures of which are incorporated herein by reference.

[0024] In preferred embodiments, the ceria abrasive particles comprise wet ceria particles or wet-process based ceria particles. As used herein, “wet ceria particles” or “wet-process based ceria particles” (collectively referred to herein as “wet-process” ceria particles) refer to ceria prepared by precipitation, condensation-polymerization, or similar methods (as opposed to, for example, fumed or pyrogenic ceria). It has been found that the polishing compositions of the present application comprising wet-process ceria particles exhibit fewer defects when used to polish substrates according to the methods of the present application. Without wishing to be bound by a particular theory, it is believed that wet-process ceria comprises ceria particles that are approximately spherical and / or smaller ceria particle aggregates, thereby resulting in lower substrate defect rates when used in the methods of the present application. Illustrative examples of wet-process ceria are HC30 TM and HC60 TM ceria and Hybrid-30 available from ANP Co., Ltd.

[0025] The ceria abrasive can be manufactured by any suitable method. As an example, the ceria abrasive can be wet-process ceria particles made according to the following method. Typically, the first step in synthesizing wet-process ceria particles is to dissolve a ceria precursor in water. The ceria precursor can be any suitable ceria precursor and can include ceria salts having any suitable charge (e.g., Ce 3+ or Ce 4+ ). Suitable ceria precursors include, for example, cerium III nitrate, cerium IV ammonium nitrate, cerium III carbonate, cerium IV sulfate, and cerium III chloride. Preferably, the ceria precursor is cerium III nitrate.

[0026] Typically, the pH of the ceria precursor solution is increased to form amorphous Ce(OH)3. The pH of the solution can be increased to any suitable pH. For example, the pH of the solution can be increased to a pH of about 10 or greater, such as a pH of about 10.5 or greater, a pH of about 11 or greater, or a pH of about 12 or greater. Typically, the solution will have a pH of about 14 or less, such as a pH of about 13.5 or less, or a pH of about 13 or less. Any suitable base can be used to increase the pH of the solution. Suitable bases include, for example, KOH, NaOH, NH4OH, and tetramethylammonium hydroxide. Organic bases, such as ethanolamine and diethanolamine, are also suitable. As the pH is increased and amorphous Ce(OH)3forms, the solution will become white and cloudy.

[0027] Typically, the ceria precursor solution is mixed for several hours. For example, the solution can be mixed for about 1 hour or more, such as about 2 hours or more, about 4 hours or more, about 6 hours or more, about 8 hours or more, about 12 hours or more, about 16 hours or more, about 20 hours or more, or about 24 hours or more. Typically, the solution is mixed for about 1 hour to about 24 hours, such as about 2 hours, about 8 hours, or about 12 hours. When mixing is complete, the solution can be transferred to a pressurized vessel and heated.

[0028] The ceria precursor solution can be heated to any suitable temperature. For example, the solution can be heated to a temperature of about 50°C or greater, such as about 75°C or greater, about 100°C or greater, about 125°C or greater, about 150°C or greater, about 175°C or greater, or about 200°C or greater. Alternatively or additionally, the solution can be heated to a temperature of about 500°C or less, such as about 450°C or less, about 400°C or less, about 375°C or less, about 350°C or less, about 300°C or less, about 250°C or less, about 225°C, or about 200°C or less. Thus, the solution can be heated to a temperature within a range bounded by any two of the foregoing endpoints. For example, the solution can be heated to a temperature of about 50°C to about 300°C, such as about 50°C to about 275°C, about 50°C to about 250°C, about 50°C to about 200°C, about 75°C to about 300°C, about 75°C to about 250°C, about 75°C to about 200°C, about 100°C to about 300°C, about 100°C to about 250°C, or about 100°C to about 225°C.

[0029] Typically, the ceria precursor solution is heated for several hours. For example, the solution can be heated for about 1 hour or more, such as about 5 hours or more, about 10 hours or more, about 25 hours or more, about 50 hours or more, about 75 hours or more, about 100 hours or more, or about 110 hours or more. Alternatively or additionally, the solution can be heated for about 200 hours or less, such as about 180 hours or less, about 165 hours or less, about 150 hours or less, about 125 hours or less, about 115 hours or less, or about 100 hours or less. Thus, the solution can be heated for a period of time defined by any two of the foregoing endpoints. For example, the solution can be heated for about 1 hour to about 150 hours, such as about 5 hours to about 130 hours, about 10 hours to about 120 hours, about 15 hours to about 115 hours, or about 25 hours to about 100 hours.

[0030] After heating, the ceria precursor solution can be filtered to isolate the precipitated ceria particles. The precipitate can be rinsed with an excess of water to remove unreacted ceria precursor. The mixture of the precipitate and excess water can be filtered after each rinsing step to remove impurities. Once sufficiently rinsed, the ceria particles can be dried for additional processing (e.g., sintering), or the ceria particles can be directly redispersed.

[0031] The ceria particles optionally can be dried and sintered prior to redispersion. The terms“sintering” and“calcining” are used interchangeably herein to refer to the heating of the ceria particles under conditions described below. Sintering the ceria particles affects the resulting crystallinity thereof. Without wishing to be bound by any particular theory, it is believed that sintering the ceria particles at high temperatures and for extended periods of time will reduce defects in the lattice structure of the particles. The ceria particles can be sintered using any suitable method. As an example, the ceria particles can be dried, and then, can be sintered at elevated temperatures. The drying can be performed at room temperature or at elevated temperatures. In particular, the drying can be performed at a temperature of about 20 °C to about 40 °C, such as about 25 °C, about 30 °C, or about 35 °C. Alternatively or additionally, the drying can be performed at an elevated temperature of about 80 °C to about 150 °C, such as about 85 °C, about 100 °C, about 115 °C, about 125 °C, or about 140 °C. After the ceria particles have been dried, they can be milled to form a powder. The milling can be performed using any suitable milling material, such as zirconia.

[0032] The ceria particles can be sintered in any suitable oven and at any suitable temperature. For example, the ceria particles can be sintered at a temperature of about 200°C or more, such as about 215°C or more, about 225°C or more, about 250°C or more, about 275°C or more, about 300°C or more, about 350°C or more, or about 375°C or more. Alternatively or additionally, the ceria particles can be sintered at a temperature of about 1000°C or less, such as about 900°C or less, about 750°C or less, about 650°C or less, about 550°C or less, about 500°C or less, about 450°C or less, or about 400°C or less. Thus, the ceria particles can be sintered at a temperature defined by any two of the foregoing endpoints. For example, the ceria particles can be sintered at a temperature of about 200°C to about 1000°C, such as about 250°C to about 800°C, about 300°C to about 700°C, about 325°C to about 650°C, about 350°C to about 600°C, about 350°C to about 550°C, about 400°C to about 550°C, about 450°C to about 800°C, about 500°C to about 1000°C, or about 500°C to about 800°C.

[0033] The ceria particles can be sintered for any suitable length of time. For example, the ceria particles can be sintered for about 1 hour or more, such as about 2 hours or more, about 5 hours or more, or about 8 hours or more. Alternatively or additionally, the ceria particles can be sintered for about 20 hours or less, such as about 18 hours or less, about 15 hours or less, about 12 hours or less, or about 10 hours or less. Thus, the ceria particles can be sintered for a period of time defined by any two of the foregoing endpoints. For example, the ceria particles can be sintered for about 1 hour to about 20 hours, such as about 1 hour to about 15 hours, about 1 hour to about 10 hours, about 1 hour to about 5 hours, about 5 hours to about 20 hours, or about 10 hours to about 20 hours.

[0034] The ceria particles can also be sintered at various temperatures and for various lengths of time within the ranges described above. For example, the ceria particles can be sintered in a zone furnace that exposes the ceria particles to one or more temperatures for various lengths of time. As an example, the ceria particles can be sintered at a temperature of about 200°C to about 1000°C for about 1 hour or more, and then can be sintered at a different temperature within the range of about 200°C to about 1000°C for about 1 hour or more.

[0035] The ceria particles are typically re-dispersed in a suitable carrier, such as an aqueous carrier, especially water. If the ceria particles are sintered, the ceria particles are re-dispersed after sintering is complete. Any suitable method can be used to re-disperse the ceria particles. Typically, the ceria particles are re-dispersed by lowering the pH of a mixture of the ceria particles and water using a suitable acid. As the pH is lowered, the surface of the ceria particles develops a positive zeta potential. This positive zeta potential creates a repulsive force between the ceria particles, which promotes re-dispersion of the ceria particles. Any suitable acid can be used to lower the pH of the mixture. Suitable acids include, for example, hydrochloric acid and nitric acid. Organic acids having a high water solubility and having a hydrophilic functional group are also suitable. Suitable organic acids include, for example, acetic acid. Acids having polyvalent anions, such as H3PO4 and H2SO4, are generally not preferred. The pH of the mixture can be lowered to any suitable pH. For example, the pH of the mixture can be lowered to about 2 to about 5, such as about 2.5, about 3, about 3.5, about 4, or about 4.5. Typically, the pH of the mixture is not lowered to less than about 2.

[0036] Typically, the re-dispersed ceria particles are milled to reduce their particle size. Preferably, the ceria particles are milled while re-dispersed. Milling can be performed using any suitable milling material, such as zirconium oxide. Milling can also be performed using ultrasonic treatment or a wet jet milling procedure. After milling, the ceria particles can be filtered to remove any remaining large particles. For example, the ceria particles can be filtered using a filter having a pore size of about 0.3 μιη or more, such as about 0.4 μιη or more, or about 0.5 μιη or more.

[0037] The ceria abrasive can have any suitable average particle size (i.e., average particle diameter). If the ceria abrasive has an average particle size that is too small, the polishing composition can not exhibit a sufficient removal rate. In contrast, if the ceria abrasive has an average particle size that is too large, the polishing composition can exhibit undesirable polishing performance, such as poor substrate defectivity. Thus, the ceria abrasive particles can have an average particle size of about 10 nm or greater, such as about 15 nm or greater, about 20 nm or greater, about 25 nm or greater, about 30 nm or greater, about 35 nm or greater, about 40 nm or greater, about 45 nm or greater, or about 50 nm or greater. Alternatively or additionally, the ceria abrasive particles can have an average particle size of about 1,000 nm or less, such as about 750 nm or less, about 500 nm or less, about 250 nm or less, about 150 nm or less, about 100 nm or less, about 75 nm or less, or about 50 nm or less. Thus, the ceria abrasive particles can have an average particle size defined by any two of the foregoing endpoints. For example, the ceria abrasive particles can have an average particle size of about 10 nm to about 1,000 nm, such as about 10 nm to about 750 nm, about 15 nm to about 500 nm, about 20 nm to about 250 nm, about 20 nm to about 150 nm, about 25 nm to about 150 nm, about 25 nm to about 100 nm, about 50 nm to about 150 nm, or about 50 nm to about 100 nm. For spherical ceria abrasive particles, the size of the particle is the diameter of the particle. For non-spherical ceria particles, the size of the particle is the diameter of the smallest sphere that encompasses the particle. The particle size of the ceria abrasive particles can be measured using any suitable technique, such as using laser diffraction techniques. Suitable particle size measuring instruments are available from, for example, Malvern Instruments (Malvern, UK).

[0038] In some embodiments, the ceria abrasive particles of the polishing composition exhibit a multimodal particle size distribution. As used herein, the term "multimodal" means that the ceria abrasive particles exhibit an average particle size distribution having at least 2 maxima (e.g., 2 or more maxima, 3 or more maxima, 4 or more maxima, or 5 or more maxima). Preferably, in these embodiments, the ceria abrasive particles exhibit a bimodal particle size distribution, i.e., the ceria abrasive particles exhibit a particle size distribution having 2 maxima of average particle size. The term "maxima" means one or more peaks in the particle size distribution. The one or more peaks correspond to the average particle sizes described herein for the ceria abrasive particles. Thus, for example, a plot of the number of particles versus particle size would reflect a bimodal particle size distribution with a first peak in the particle size range of about 75 nm to about 150 nm, e.g., about 80 nm to about 140 nm, about 85 nm to about 130 nm, or about 90 nm to about 120 nm, and a second peak in the particle size range of about 25 nm to about 70 nm, e.g., about 30 nm to about 65 nm, about 35 nm to about 65 nm, or about 40 nm to about 60 nm. Ceria abrasive particles having a multimodal particle size distribution can be obtained by combining two different ceria abrasive particles each having a unimodal particle size distribution.

[0039] The ceria abrasive particles are preferably colloidally stable in the polishing compositions of the present application. The term colloid refers to a suspension of the ceria abrasive particles in an aqueous carrier, such as water. Colloidal stability refers to the retention of the suspension over time. In the context of the present application, the abrasive is considered to be colloidally stable if the difference between the concentration of particles in the bottom 50 mL of a 100 mL graduated cylinder ([B], in g / mL) and the concentration of particles in the top 50 mL of the graduated cylinder ([T], in g / mL) divided by the initial concentration of particles in the abrasive composition ([C], in g / mL) is less than or equal to 0.5 (i.e., {[B]-[T]} / [C] < 0.5) when the abrasive is placed in the graduated cylinder and allowed to stand for a period of 2 hours without agitation. More preferably, the value of [B]-[T] / [C] is less than or equal to 0.3, and most preferably less than or equal to 0.1.

[0040] The polishing composition can include any suitable amount of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof). If the polishing composition of the present application includes too little abrasive, the composition can fail to exhibit a sufficient removal rate. In contrast, if the polishing composition includes too much abrasive, the polishing composition can exhibit undesirable polishing performance and / or can not be cost effective and / or can lack stability. The polishing composition includes about 10 wt.% or less, for example, about 9 wt.% or less, about 8 wt.% or less, about 7 wt.% or less, about 6 wt.% or less, about 5 wt.% or less, about 4 wt.% or less, about 3 wt.% or less, about 2 wt.% or less, about 1 wt.% or less, about 0.9 wt.% or less, about 0.8 wt.% or less, about 0.7 wt.% or less, about 0.6 wt.% or less, or about 0.5 wt.% or less, of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof). Alternatively or additionally, the polishing composition includes about 0.001 wt.% or more, for example, about 0.005 wt.% or more, about 0.01 wt.% or more, about 0.05 wt.% or more, or about 0.1 wt.% or more, of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof). Thus, the abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof) can be present in the polishing composition in an amount defined by any two of the foregoing endpoints. For example, the polishing composition can include about 0.001 wt.% to about 10 wt.% for example, about 0.001 wt.% to about 9 wt.%, about 0.005 wt.% to about 8 wt.%, about 0.01 wt.% to about 7 wt.%, about 0.05 wt.% to about 6 wt.%, about 0.1 wt.% to about 5 wt.%, about 0.5 wt.% to about 5 wt.%, about 0.5 wt.% to about 4 wt.%, about 1 wt.% to about 3 wt.%, or about 1.5 wt.% to about 2.5 wt.% of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof). In embodiments, the polishing composition can include about 0.1 wt.% to about 1 wt.% or about 0.1 wt.% to about 0.5 wt.% of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof) at the point of use. In another embodiment, the polishing composition includes about 1 wt.% to 3 wt.% (e.g., about 1.2 wt.% or about 1.6 wt.%) of abrasive (e.g., ceria abrasive, zirconia abrasive, or a combination thereof) in the form of a concentrate.

[0041] The polishing composition includes a self-stopping agent. The self-stopping agent can be any suitable compound capable of reducing the removal rate of one or more of silicon oxide and polysilicon. In some embodiments, the self-stopping agent has the formula (I):

[0042]

[0043] wherein R is selected from the group consisting of: hydrogen, alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, each of which can be substituted or unsubstituted.

[0044] As used herein, the term "alkyl" refers to a straight-chain or branched-chain, saturated or unsaturated aliphatic radical having the indicated number of carbon atoms. Alkyl groups can include any number of carbon atoms, such as C 1-2 , C 1-3 , C 1-4 , C 1-5 , C 1-6 , C 1-7 , C 1-8 , C 1-9 , C 1-10 , C 2-3 , C 2-4 , C 2-5 , C 2-6 , C 3-4 , C 3-5 , C 3-6 , C 4-5 , C 4-6 , and C 5-6 . For example, C 1-6 alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, hexyl, and the like. Alkyl groups can also refer to alkyl groups having up to 30 carbon atoms, such as, but not limited to, heptyl, octyl, nonyl, decyl, and the like. Alkyl groups can be substituted or unsubstituted. "Substituted alkyl" can be substituted with one or more groups selected from halo, hydroxyl, amino, oxo (=0), alkylamino, acylamino, acyl, nitro, cyano, and alkoxy.

[0045] As used herein, the term "heteroalkyl" refers to an alkyl group as described herein in which one or more carbon atoms are optionally and independently replaced with a heteroatom selected from N, O, and S.

[0046] As used herein, the term "cycloalkyl" refers to a saturated or partially unsaturated, monocyclic, fused-bicyclic, or bridged polycyclic assembly of 3 to 12 ring atoms or the indicated number of atoms. Cycloalkyl groups can include any number of carbon atoms, such as C 3-6 , C 4-6 , C 5-6 , C 3-8 , C 4-8 , C 5-8 , C 6-8 , C 3-9 , C 3-10 , C 3-11 , and C 3-12Saturated monocyclic carbocyclic rings include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl. Saturated bicyclic and polycyclic carbocyclic rings include, for example, norbornane, [2.2.2]bicyclooctane, decalin, and adamantane. Carbocyclic groups can also be partially unsaturated, having one or more double or triple bonds in the ring. Representative partially unsaturated carbocyclic groups include, but are not limited to, cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclohexadienyl (1,3- and 1,4-isomers), cycloheptenyl, cycloheptadienyl, cyclooctenyl, cyclooctadienyl (1,3-, 1,4-, and 1,5-isomers), norbornenyl, and norbornadienyl.

[0047] As used herein, the term "heteroalkyl" refers to an alkyl group as described herein in which one or more carbon atoms are optionally and independently replaced with a heteroatom selected from N, O, and S.

[0048] As used herein, the term "aryl" refers to an aromatic ring system having any suitable number of ring atoms and any suitable number of rings. An aryl group can include any suitable number of ring atoms, such as 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 ring atoms, as well as 6 to 10, 6 to 12, or 6 to 14 ring members. An aryl group can be monocyclic, fused to form a bicyclic or tricyclic group, or linked through a bond to form a biaryl group. Representative aryl groups include phenyl, naphthyl, and biphenyl. Other aryl groups include benzyl groups having a methylene linker. Some aryl groups have 6 to 12 ring members, such as phenyl, naphthyl, or biphenyl. Other aryl groups have 6 to 10 ring members, such as phenyl or naphthyl.

[0049] As used herein, the term "heteroaryl" refers to an aryl group as described herein in which one or more carbon atoms are optionally and independently replaced with a heteroatom selected from N, O, and S.

[0050] In certain embodiments, the stopper is selected from the group consisting of hydroxamic acid, acetylhydroxamic acid, benzhydroxamic acid (benzohydroxamic acid), salicylhydroxamic acid, and combinations thereof.

[0051] The polishing composition can include any suitable amount of the self- stopping agent. The polishing composition can include about 10 ppm or more, such as about 15 ppm or more, about 20 ppm or more, about 25 ppm or more, about 30 ppm or more, about 35 ppm or more, or about 40 ppm or more of the self-stopping agent. Alternatively or additionally, the polishing composition can include about 5000 ppm or less, such as about 3000 ppm or less, about 1000 ppm or less, about 800 ppm or less, about 600 ppm or less, about 400 ppm or less, about 200 ppm or less, or about 100 ppm or less of the self-stopping agent. Thus, the polishing composition can include an amount of the self-stopping agent defined by any two of the foregoing endpoints. For example, the polishing composition can include about 10 ppm to about 5000 ppm, such as about 10 ppm to about 3000 ppm, about 10 ppm to about 1000 ppm, about 10 ppm to about 800 ppm, about 10 ppm to about 600 ppm, about 10 ppm to about 400 ppm, about 10 ppm to about 200 ppm, about 10 ppm to about 100 ppm, about 25 ppm to about 5000 ppm, about 25 ppm to about 3000 ppm, about 25 ppm to about 1000 ppm, about 25 ppm to about 800 ppm, about 25 ppm to about 600 ppm, about 25 ppm to about 400 ppm, about 25 ppm to about 200 ppm, or about 25 ppm to about 100 ppm of the self-stopping agent.

[0052] Without wishing to be bound by any particular theory, it is believed that the self-stopping agent facilitates a non-linear response to a given downforce (DF) on a blanket TEOS dielectric material. During polishing, the patterned dielectric material experiences an effective downforce (DF) that is higher than the downforce on the blanket dielectric material because contact is distributed only on portions of the patterned dielectric material that are in contact with the pad. The higher effective DF applied to the TEOS patterned dielectric material results in a polishing regime where the TEOS removal rate is about a "high" removal rate (e.g., pattern removal rate) for lower effective DFs resulting in a "stop" polishing regime where the TEOS removal rate is about or less (e.g., blanket removal rate). The difference between the "high" regime and the "stop" regime is typically pronounced, such that for a given DF, either a "high" removal rate or a "stop" removal rate is observed. Thus, it is believed that the self-stopping agent desirably enables a "high" removal rate (i.e., pattern removal rate) even when the applied DF is in the "stop" regime as determined with a blanket wafer.

[0053] Furthermore, it should also be noted that the mechanism does not depend solely on DF, as the trench oxide removal rate on patterned dielectric material is higher than the blanket removal rate, despite having a lower effective DF in the trench compared to on the blanket wafer. For example, in some polishing applications, the concentration of the self-stop agent plays a role in the observed effects, as at low concentrations, the self-stop agent can act as a rate enhancer (e.g., a "high" removal rate is observed), and at higher concentrations, a self-stop behavior is observed (e.g., a "stop" removal rate is observed). Thus, some rate enhancers can have a dual role. For example, when the polishing composition includes a lower concentration of picolinic acid, the picolinic acid can act as a rate enhancer. However, when the polishing composition includes a higher concentration of picolinic acid, the picolinic acid can act as a self-stop agent. Typically, picolinic acid acts as a rate enhancer at concentrations less than about 1000 ppm by weight (e.g., about 500 ppm, about 250 ppm, etc.).

[0054] The chemical mechanical polishing composition includes a cationic monomer compound. The cationic monomer compound can be any suitable cationic (e.g., ammonium) compound that is believed by those skilled in the art to be capable of undergoing polymerization (e.g., via free radical polymerization, addition polymerization, displacement polymerization, or the like). For example, the cationic monomer compound can be 2-(dimethylamino)ethyl acrylate ("DMAEA"), 2-(dimethylamino)ethyl methacrylate ("DMAEM"), 3-(dimethylamino)propyl methacrylamide ("DMAPMA"), 3-(dimethylamino)propyl acrylamide ("DMAPA"), 3-methacrylamidopropyl-trimethylammonium chloride ("MAPTAC"), 3-acrylamidopropyl-trimethylammonium chloride ("APTAC"), diallyldimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEM.MCQ"), N,N-dimethylaminoethyl acrylate benzyl chloride ("DMAEA.BCQ"), N,N-dimethylaminoethyl methacrylate benzyl chloride ("DMAEM.BCQ"), salts thereof, and combinations thereof. In certain embodiments, the cationic monomer compound is selected from diallyldimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEM.MCQ"), salts thereof, and combinations thereof. In preferred embodiments, the cationic monomer compound is diallyldimethylammonium chloride ("DADMAC") or a salt thereof.

[0055] The polishing composition can include the cationic monomer compound in any suitable amount. The polishing composition can include about 10 ppm or more, for example, about 15 ppm or more, about 20 ppm or more, about 25 ppm or more, about 30 ppm or more, about 35 ppm or more, or about 40 ppm or more of the cationic monomer compound. Alternatively or additionally, the polishing composition can include about 1000 ppm or less, for example, about 800 ppm or less, about 600 ppm or less, about 400 ppm or less, about 200 ppm or less, or about 100 ppm or less of the cationic monomer compound. Thus, the polishing composition can include the cationic monomer compound in an amount defined by any two of the foregoing endpoints. For example, the polishing composition can include about 10 ppm to about 1000 ppm, for example, about 10 ppm to about 800 ppm, about 10 ppm to about 600 ppm, about 10 ppm to about 400 ppm, about 10 ppm to about 200 ppm, about 10 ppm to about 100 ppm, about 25 ppm to about 1000 ppm, about 25 ppm to about 800 ppm, about 25 ppm to about 600 ppm, about 25 ppm to about 400 ppm, about 25 ppm to about 200 ppm, or about 25 ppm to about 100 ppm of the cationic monomer compound.

[0056] In some embodiments, the polishing composition further includes a non-ionic polymer. Thus, in some aspects, the present application provides a chemical mechanical polishing composition including, consisting essentially of, or consisting of: (a) an abrasive selected from ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stopping agent selected from compounds of Formula (I):

[0057]

[0058] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) a non-ionic polymer; (d) a cationic monomer compound; and (e) water, wherein the pH of the polishing composition is about 5.5 to about 8.

[0059] The non-ionic polymer can be any suitable polymer that is not cationic or anionic charged at a pH of about 5.5 to about 8. In some embodiments, the non-ionic polymer is selected from the group consisting of polyalkylene glycols, polyether amines, polyethylene oxide / polypropylene oxide copolymers, polyacrylamides, polyvinylpyrrolidones, silicone polyalkylene oxide copolymers, hydrophobically modified polyacrylate copolymers, hydrophilic non-ionic polymers, polysaccharides, and combinations thereof. In certain embodiments, the non-ionic polymer is a polyvinylpyrrolidone, a polyalkylene glycol (e.g., polyethylene glycol (PEG) or polypropylene oxide (PPO)), a polyethylene oxide / polypropylene oxide copolymer, or a combination thereof. In preferred embodiments, the non-ionic polymer is a polyethylene glycol (PEG).

[0060] The nonionic polymer can have any suitable weight average molecular weight. The nonionic polymer can have a weight average molecular weight of about 400 g / mol or more, for example, about 500 g / mol or more, about 600 g / mol or more, about 750 g / mol or more, about 1,000 g / mol or more, about 1,500 g / mol or more, about 2,000 g / mol or more, about 2,500 g / mol or more, about 3,000 g / mol or more, about 3,500 g / mol or more, about 4,000 g / mol or more, about 4,500 g / mol or more, about 5,000 g / mol or more, about 5,500 g / mol or more, about 6,000 g / mol or more, about 6,500 g / mol or more, about 7,000 g / mol or more, or about 7,500 g / mol or more. Alternatively or additionally, the nonionic polymer can have a weight average molecular weight of about 20,000 g / mol or less, for example, about 10,000 g / mol or less, about 9,000 g / mol or less, about 8,000 g / mol or less, about 7,500 g / mol or less, about 7,000 g / mol or less, about 6,500 g / mol or less, about 6,000 g / mol or less, about 5,500 g / mol or less, about 5,000 g / mol or less, about 4,500 g / mol or less, about 4,000 g / mol or less, about 3,500 g / mol or less, about 3,000 g / mol or less, about 2,500 g / mol or less, or about 2,000 g / mol or less. Thus, the nonionic polymer can have a weight average molecular weight defined by any two of the foregoing endpoints. For example, the nonionic polymer can have a weight average molecular weight of about 400 g / mol to about 20,000 g / mol, for example, about 400 g / mol to about 10,000 g / mol, about 400 g / mol to about 9,000 g / mol, about 400 g / mol to about 8,000 g / mol, about 400 g / mol to about 7,000 g / mol, about 400 g / mol to about 6,000 g / mol, about 400 g / mol to about 5,000 g / mol, about 1000 g / mol to about 20,000 g / mol, about 1000 g / mol to about 10,000 g / mol, about 1000 g / mol to about 9,000 g / mol, about 1000 g / mol to about 8,000 g / mol, about 1000 g / mol to about 7,000 g / mol, about 1000 g / mol to about 6,000 g / mol, or about 1000 g / mol to about 5,000 g / mol.

[0061] When present, the polishing composition can include any suitable amount of nonionic polymer. The polishing composition can include about 25 ppm or more, such as about 50 ppm or more, about 100 ppm or more, or about 200 ppm or more, of nonionic polymer. Alternatively or additionally, the polishing composition can include about 5000 ppm or less, such as about 4000 ppm or less, about 3000 ppm or less, about 2000 ppm or less, or about 1000 ppm or less, of nonionic polymer. Thus, the polishing composition can include an amount of nonionic polymer defined by any two of the foregoing endpoints. For example, the polishing composition can include about 25 ppm to about 5000 ppm, such as about 25 ppm to about 4000 ppm, about 25 ppm to about 3000 ppm, about 25 ppm to about 2000 ppm, about 25 ppm to about 1000 ppm, about 50 ppm to about 5000 ppm, about 50 ppm to about 4000 ppm, about 50 ppm to about 3000 ppm, about 50 ppm to about 2000 ppm, about 50 ppm to about 1000 ppm, about 100 ppm to about 5000 ppm, or about 100 ppm to about 1000 ppm, of nonionic polymer.

[0062] The polishing composition includes an aqueous carrier. The aqueous carrier includes water (e.g., deionized water) and can contain one or more water-miscible organic solvents. Examples of organic solvents that can be used include alcohols such as propenol, isopropyl alcohol, ethanol, 1-propanol, methanol, 1-hexanol, and the like; aldehydes such as acetaldehyde and the like; ketones such as acetone, diacetone alcohol, methyl ethyl ketone, and the like; esters such as ethyl formate, propyl formate, ethyl acetate, methyl acetate, methyl lactate, butyl lactate, ethyl lactate, and the like; ethers including sulfoxides such as dimethyl sulfoxide (DMSO), tetrahydrofuran, dioxane, diglyme, and the like; amides such as N,N-dimethylformamide, dimethylimidazolidinone, N-methylpyrrolidinone, and the like; polyols and derivatives thereof such as ethylene glycol, glycerol, diethylene glycol, diethylene glycol monomethyl ether, and the like; and nitrogen-containing organic compounds such as acetonitrile, pentylamine, isopropylamine, imidazole, dimethylamine, and the like. Preferably, the aqueous carrier is water only, i.e., no organic solvent is present.

[0063] The chemical mechanical polishing composition can include one or more compounds capable of adjusting (i.e., adjusting) the pH of the polishing composition (i.e., pH adjusting compounds). The pH of the polishing composition can be adjusted using any suitable compound capable of adjusting the pH of the polishing composition. The pH adjusting compounds desirably are water soluble and compatible with the other components of the polishing composition. Typically, the chemical mechanical polishing composition has a pH at the point of use of from about 5.5 to about 8 (e.g., a pH of from about 5.5 to about 7.5, from about 5.5 to about 7, from about 5.5 to about 6.5, from about 5.5 to about 6, from about 6 to about 8, from about 6 to about 7.5, from about 6 to about 7, from about 6 to about 6.5, from about 7 to about 8, or from about 7 to about 7.5). In certain embodiments, the chemical mechanical polishing composition has a pH at the point of use of from about 5.5 to about 7. Preferably, the chemical mechanical polishing composition has a pH at the point of use of from about 6 to about 6.5.

[0064] Compounds capable of adjusting and buffering the pH can be selected from the group consisting of alkyl amines, ammonium salts, alkali metal salts, carboxylic acids, alkali metal hydroxides, alkali metal nitrates, alkali metal carbonates, alkali metal bicarbonates, borates, and mixtures thereof.

[0065] The chemical mechanical polishing composition optionally further includes one or more additives. Exemplary additives include conditioning agents, acids (e.g., sulfonic acids), complexing agents, chelating agents, biocides, scale inhibitors, and dispersants.

[0066] When present, the biocide can be any suitable biocide and can be present in the polishing composition in any suitable amount. Suitable biocides are isothiazolinone biocides. The biocide can be present in the polishing composition at a concentration of from about 1 to about 750 ppm, preferably from about 20 to about 200 ppm.

[0067] The polishing composition can be produced by any suitable technique, many of which are known to those skilled in the art. The polishing composition can be prepared in a batch or continuous process. Generally, the polishing composition is prepared by combining the components of the polishing composition. The term "component" as used herein includes an individual ingredient (e.g., abrasive, self-stop agent, cationic monomer compound, optional nonionic polymer, and / or any other optional additive) as well as any combination of ingredients (e.g., abrasive, self-stop agent, cationic monomer compound, optional nonionic polymer, and / or any other optional additive, etc.).

[0068] For example, the polishing composition can be prepared by: (i) providing all or a portion of the liquid carrier; (ii) dispersing the abrasive, the self-stopping agent, the cationic monomer compound, the optional non-ionic polymer, and / or any other optional additives using any suitable means for preparing such dispersions; (iii) adjusting the pH of the dispersion, as appropriate; and (iv) optionally adding to the mixture an appropriate amount of any other optional components and / or additives.

[0069] Alternatively, the polishing composition can be prepared by: (i) providing one or more components (e.g., the self-stopping agent, the cationic monomer compound, the optional non-ionic polymer, and / or any other optional additives) in an abrasive slurry; (ii) providing one or more components (e.g., the self-stopping agent, the cationic monomer compound, the optional non-ionic polymer, and / or any other optional additives) in an additive solution; (iii) combining the abrasive slurry and the additive solution to form a mixture; (iv) optionally adding to the mixture an appropriate amount of any other optional additives; and (v) adjusting the pH of the mixture, as appropriate.

[0070] The polishing composition can be supplied in a single-pouch system comprising the abrasive, the self-stopping agent, the cationic monomer compound, the optional non-ionic polymer, any other optional additives, and water. Alternatively, the polishing composition of the present application can be supplied in a dual-pouch system comprising an abrasive slurry in a first pouch and an additive solution in a second pouch, wherein the abrasive slurry consists essentially of or consists of abrasive particles and water, and wherein the additive solution consists essentially of or consists of the self-stopping agent, the cationic monomer compound, the optional non-ionic polymer, and / or any other optional additives. The dual-pouch system allows for adjustment of the characteristics of the polishing composition by varying the blend ratio of the two pouches, i.e., the abrasive slurry and the additive solution.

[0071] Different methods can be used to utilize such a dual-pouch polishing system. For example, the abrasive slurry and the additive solution can be delivered to the polishing table through different tubes that are joined and connected at the outlet of the supply pipe. The abrasive slurry and the additive solution can be mixed shortly before or just prior to polishing, or can be supplied simultaneously on the polishing table. In addition, deionized water can be added as needed to adjust the polishing characteristics of the polishing composition and the resulting substrate when mixing the two pouches.

[0072] Similarly, a three-pouch, four-pouch, or more pouch system can be utilized in conjunction with the present application, wherein each of the plurality of containers contains a different component of the chemical mechanical polishing composition of the present application, one or more optional components, and / or one or more of the same components in different concentrations.

[0073] To mix the components contained in two or more storage devices at or near the point of use to produce a polishing composition, the storage devices are typically equipped with one or more flow lines leading from each storage device to the point of use of the polishing composition (e.g., a platen, polishing pad, or substrate surface). As used herein, the term "point of use" refers to the site at which the polishing composition is applied to a substrate surface (e.g., a polishing pad or the substrate surface itself). The term "flow line" means a flow path from an individual storage container to the point of use of the component stored therein. The flow lines can each lead directly to the point of use, or two or more flow lines can merge at any point into a single flow line leading to the point of use. In addition, any of the flow lines (e.g., individual flow lines or merged flow lines) can lead to one or more other devices (e.g., pumping devices, metering devices, mixing devices, etc.) before reaching the point of use of the components.

[0074] The components of the polishing composition can be delivered to the point of use independently (e.g., delivering the components to the substrate surface, after which the components are mixed during the polishing process), or one or more components can be combined prior to delivery to the point of use, e.g., shortly before or just before delivery to the point of use. Components are "combined just before delivery to the point of use" if the components are combined about 5 minutes or less before addition to the platen in a mixed form, e.g., about 4 minutes or less, about 3 minutes or less, about 2 minutes or less, about 1 minute or less, about 45 seconds or less, about 30 seconds or less, about 10 seconds or less, before addition to the platen in a mixed form, or at the same time as delivery of the components at the point of use (e.g., combining the components at the dispenser). Components are also "combined just before delivery to the point of use" if the components are combined within 5 m of the point of use, such as within 1 m of the point of use or even within 10 cm of the point of use (e.g., within 1 cm of the point of use).

[0075] When the two or more components of the polishing composition are combined prior to reaching the point of use, the components can be combined in a flow line and delivered to the point of use without the use of a mixing device. Alternatively, one or more flow lines can pass into a mixing device to facilitate the combination of the two or more components. Any suitable mixing device can be used. For example, the mixing device can be a nozzle or jet (e.g., a high pressure nozzle or jet) through which the two or more components flow. Alternatively, the mixing device can be a vessel-type mixing device that includes one or more inlets through which the two or more components of the polishing slurry are introduced into the mixer and at least one outlet through which the mixed components exit the mixer for delivery to the point of use either directly or via other elements of the apparatus (e.g., via one or more flow lines). Further, the mixing device can include more than one chamber, each chamber having at least one inlet and at least one outlet, with the two or more components being combined in each chamber. If a vessel-type mixing device is used, the mixing device preferably includes a mixing mechanism to further facilitate the combination of the components. Mixing mechanisms are generally known in the art and include agitators, blenders, stirrers, paddle baffles, gas sparger systems, vibrators, and the like.

[0076] The polishing composition can also be provided in a concentrate form, which is intended to be diluted with an appropriate amount of water prior to use. In such embodiments, the polishing composition concentrate includes amounts of the components of the polishing composition such that upon dilution of the concentrate with an appropriate amount of water, each component of the polishing composition will be present in the polishing composition in an amount within the appropriate range described above for each component. For example, the abrasive, the self-stopping agent, the cationic monomer compound, the optional nonionic polymer, and / or any other optional additives can each be present in the concentrate in an amount that is about 2 times (e.g., about 3 times, about 4 times, or about 5 times) the concentration described above for each component, such that when the concentrate is diluted with an equal volume of water (e.g., 2 times the volume of water, 3 times the volume of water, or 4 times the volume of water, respectively), each component will be present in the polishing composition in an amount within the range described above for each component. Further, one of ordinary skill in the art will appreciate that the concentrate can contain water in a suitable ratio to be present in the final polishing composition in order to ensure that the abrasive particles, the self-stopping agent, the cationic monomer compound, the optional nonionic polymer, and / or any other optional additives are at least partially or completely dissolved in the concentrate.

[0077] The present disclosure further provides a method of chemically-mechanically polishing a substrate comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical-mechanical polishing composition comprising: (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stoppage agent selected from the group consisting of compounds of Formula (I):

[0078]

[0079] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) an optional non-ionic polymer; (d) a cationic monomeric compound; and (e) water, wherein the pH of the polishing composition is from about 5.5 to about 8; (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate, thereby polishing the substrate.

[0080] The chemical-mechanical polishing composition can be used to polish any suitable substrate and is particularly useful for polishing a substrate comprising at least one low dielectric material-containing layer, typically a surface layer. Suitable substrates include wafers used in the semiconductor industry. The wafers typically comprise or consist of, for example, a metal, a metal oxide, a metal nitride, a metal composite, a metal alloy, or combinations thereof. The methods of the present disclosure are particularly useful for polishing a substrate comprising silicon oxide and / or polysilicon, such as any or all of the foregoing materials. In some embodiments, the substrate comprises silicon oxide and polysilicon on a surface of the substrate, and at least a portion of the silicon oxide and / or polysilicon on the surface of the substrate is abraded to polish the substrate.

[0081] In certain embodiments, the substrate comprises silicon oxide and polysilicon. The polysilicon can be any suitable polysilicon, many of which are known in the art. The polysilicon can have any suitable phase, and can be amorphous, crystalline, or combinations thereof. The silicon oxide similarly can be any suitable silicon oxide, many of which are known in the art. Suitable types of silicon oxide include, but are not limited to, borophosphosilicate glass (BPSG), high-density plasma (HDP) oxide, and / or plasma-enhanced tetraethylorthosilicate (PETEOS) and / or tetraethylorthosilicate (TEOS), thermal oxide, and undoped silicate glass.

[0082] The chemical mechanical polishing compositions of the present application can be tailored to provide effective polishing within a desired polishing range selective to a particular thin layer material while minimizing surface imperfections, defects, corrosion, erosion, and removal of stop layers. Selectivity can be controlled to some extent by varying the relative concentrations of the components of the polishing composition. As used herein, the term "selectivity" refers to the ratio of the removal rates of two different target materials. For example, selectivity can refer to the ratio of the removal rates of two different materials or the ratio of the removal rates of two different topographies (e.g., blanket removal versus active removal).

[0083] When desired, the chemical mechanical polishing compositions of the present application can provide an active silicon oxide removal rate of at least For example, at least at least at least or at least active silicon oxide removal rate. Alternatively or additionally, the chemical mechanical polishing compositions of the present application can provide a selectivity of active silicon oxide removal rate to blanket silicon oxide removal rate of at least 20: 1, for example, at least 25: 1, at least 30: 1, at least 35: 1, or at least 40: 1. In certain embodiments, the chemical mechanical polishing compositions of the present application provide an active silicon oxide removal rate of at least active silicon oxide removal rate and a selectivity of active silicon oxide removal rate to blanket silicon oxide removal rate of at least 25: 1. In preferred embodiments, the chemical mechanical polishing compositions of the present application provide an active silicon oxide removal rate of at least active silicon oxide removal rate and a selectivity of active silicon oxide removal rate to blanket silicon oxide removal rate of at least 30: 1.

[0084] Similarly, in certain aspects, the present application further provides a method of chemically mechanically polishing a substrate comprising, consisting essentially of, or consisting of: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical mechanical polishing composition comprising: (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof; (b) a self-stopping agent selected from the group consisting of compounds of Formula (I):

[0085]

[0086] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted; (c) a non-ionic polymer; (d) a cationic monomer compound; and (e) water, wherein the pH of the polishing composition is from about 5.5 to about 8; (iv) contacting a substrate with the polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate, thereby polishing the substrate.

[0087] When desired, the chemical mechanical polishing composition of the present application can provide selective chemical mechanical polishing of a substrate comprising silicon oxide and polysilicon to selectively remove silicon oxide at an increased rate relative to polysilicon. In this regard, the method can remove silicon oxide at a selectivity of greater than about 20: 1 as measured by the number of Angstroms removed per minute relative to polysilicon. In some embodiments, the method can remove silicon oxide at a selectivity of greater than about 40: 1 as measured by the number of Angstroms removed per minute relative to polysilicon. In certain embodiments, the method can remove silicon oxide at a selectivity of greater than about 80: 1 as measured by the number of Angstroms removed per minute relative to polysilicon.

[0088] Without wishing to be bound by any particular theory, it is believed that the addition of a non-ionic polymer can selectively reduce the removal rate of polysilicon such that the selectivity for removing silicon oxide relative to polysilicon is increased. In other words, the non-ionic polymer can reduce the removal rate of polysilicon while having little to no effect on the removal rate of silicon oxide.

[0089] Generally, the chemical mechanical polishing composition of the present application is stable when exposed to the polishing process as evidenced by the abrasive particle size growth during polishing. For example, in some embodiments, the average abrasive particle size (i.e., average particle diameter) after polishing is less than 100% greater than the average abrasive particle size (i.e., average particle diameter) before polishing. In certain embodiments, the average abrasive particle size (i.e., average particle diameter) after polishing is less than 50% greater than the average abrasive particle size (i.e., average particle diameter) before polishing. In preferred embodiments, the average abrasive particle size (i.e., average particle diameter) after polishing is less than 20% greater than the average abrasive particle size (i.e., average particle diameter) before polishing.

[0090] Without wishing to be bound by any particular theory, it is believed that the use of a cationic monomer compound in place of a cationic polymer and / or a lower pH (e.g., from about 6 to about 6.5) can result in a more stable polishing composition. As demonstrated by Example 4 provided herein, a polishing composition containing a cationic polymer and having a pH of 7.8 at the point of use can increase the particle size by more than 400% from before polishing to after polishing.

[0091] The polishing compositions of the present application desirably exhibit low particle defects when polishing a substrate, as determined by suitable techniques. In preferred embodiments, the chemical mechanical polishing compositions of the present application include wet ceria that contribute to low defectivity. Particle defects on a substrate polished with the polishing compositions of the present application can be determined by any suitable technique. For example, laser light scattering techniques such as dark field normal beam compounding (DCN) and dark field oblique beam compounding (DCO) can be used to determine particle defects on a polished substrate. Suitable instruments for evaluating particle defectivity are available from, for example, KLA-Tencor (SURFSCAN® SPI instruments) operating at a 120 nm threshold or at a 160 nm threshold. TM SPI instruments) operating at a 120 nm threshold or at a 160 nm threshold.

[0092] The DCN values for substrates (especially silicon comprising silicon oxide and / or polysilicon) polished with the polishing compositions of the present application are desirably about 20,000 counts or less, for example, about 17,500 counts or less, about 15,000 counts or less, about 12,500 counts or less, about 3,500 counts or less, about 3,000 counts or less, about 2,500 counts or less, about 2,000 counts or less, about 1,500 counts or less, or about 1,000 counts or less. Preferably, the DCN values for substrates polished according to embodiments of the present application are about 750 counts or less, for example, about 500 counts or less, about 250 counts or less, about 125 counts or less, or even about 100 counts or less. Alternatively or additionally, substrates polished with the chemical mechanical polishing compositions of the present application desirably exhibit few scratches, as determined by suitable techniques. For example, silicon wafers polished according to embodiments of the present application desirably have about 250 scratches or less, or about 125 scratches or less, as determined by any suitable method known in the art.

[0093] The chemical mechanical polishing compositions and methods of the present application are particularly suitable for use in conjunction with a chemical mechanical polishing apparatus. Typically, the apparatus includes a platen that is in motion when in use and has a velocity resulting from orbital, linear, or circular motion; a polishing pad in contact with the platen and moving therewith as the platen moves; and a carrier holding a substrate that is polished by contacting and moving the substrate relative to the surface of the polishing pad. Polishing of the substrate is carried out by placing the substrate in contact with the polishing pad and the polishing composition of the present application, and then moving the polishing pad relative to the substrate so as to abrade at least a portion of the substrate to polish the substrate.

[0094] The substrate can be polished with the chemical mechanical polishing composition using any suitable polishing pad (e.g., polishing surface). Suitable polishing pads include, for example, woven and non-woven polishing pads. In addition, suitable polishing pads can comprise any suitable polymer having different densities, hardnesses, thicknesses, compressibilities, abilities to rebound after compression, and compressive moduli. Suitable polymers include, for example, polyvinyl chloride, polyfluorovinyl, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, co-forms thereof, and mixtures thereof. Soft polyurethane polishing pads are particularly suitable for use in connection with the polishing method of the present application. Exemplary pads include, but are not limited to, SURFIN TM 000、SURFIN TM SSW1, SPM 3100 (Eminess Technologies), POLITEX available from Dow Chemical Company (Newark, DE) TM and POLYPAS available from Fujibo (Osaka, JP) TM 27, and EPIC TM D100 pads or NEXPLANAR TM E6088. A preferred polishing pad is the rigid, microcellular polyurethane pad (IC1010 TM

[0095] Desirably, the chemical mechanical polishing apparatus further comprises an in-situ polishing endpoint detection system, of which there are many known in the art. Techniques for detecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of the substrate being polished are known in the art. Such methods are described, for example, in U.S. Patent 5,196,353, U.S. Patent 5,433,651, U.S. Patent 5,609,511, U.S. Patent 5,643,046, U.S. Patent 5,658,183, U.S. Patent 5,730,642, U.S. Patent 5,838,447, U.S. Patent 5,872,633, U.S. Patent 5,893,796, U.S. Patent 5,949,927, and U.S. Patent 5,964,643. Desirably, detection or monitoring of the progress of the polishing process for a substrate being polished enables determination of the polishing endpoint, i.e., determination of when to terminate the polishing process for a particular substrate.

[0096] Embodiments

[0097] (1) In embodiment (1) is presented a chemical mechanical polishing composition comprising:

[0098] ​(a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof;

[0099] (b) a self-stopping agent selected from the group consisting of compounds of Formula (I):

[0100]

[0101] wherein R is selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted;

[0102] (c) a cationic monomeric compound; and

[0103] (d) water,

[0104] wherein the pH of the polishing composition is from about 5.5 to about 8.

[0105] (2) In embodiment (2), there is presented a polishing composition as in embodiment (1), wherein the polishing composition comprises from about 0.001 wt.% to about 10 wt.% of the abrasive.

[0106] (3) In embodiment (3), there is presented a polishing composition as in embodiment (1) or embodiment (2), wherein the polishing composition comprises from about 0.05 wt.% to about 5 wt.% of the abrasive.

[0107] (4) In embodiment (4), there is presented a polishing composition as in any one of embodiments (1) to (3), wherein the abrasive is a ceria abrasive.

[0108] (5) In embodiment (5), there is presented a polishing composition as in any one of embodiments (1) to (3), wherein the abrasive is a zirconia abrasive.

[0109] (6) In embodiment (6), there is presented a polishing composition as in any one of embodiments (1) to (5), wherein the pH of the polishing composition is from about 5.5 to about 7.

[0110] (7) In embodiment (7), there is presented a polishing composition as in any one of embodiments (1) to (6), wherein the pH of the polishing composition is from about 6 to about 6.5.

[0111] (8) In embodiment (8), there is presented a polishing composition as in any one of embodiments (1) to (7), wherein the self-stopping agent is selected from the group consisting of hydroxamic acid, acetyl hydroxamic acid, phenyl hydroxamic acid, salicyl hydroxamic acid, and combinations thereof.

[0112] (9) In embodiment (9), there is presented a polishing composition as in any one of embodiments (1) to (8), wherein the self-stopping agent is a hydroxamic acid.

[0113] (10) In embodiment (10) is presented a polishing composition as in any one of embodiments (1) to (8), wherein the self-stoppage agent is a phenyl hydroxamic acid.

[0114] (11) In embodiment (11) is presented a polishing composition as in any one of embodiments (1) to (8), wherein the self-stoppage agent is a salicyl hydroxamic acid.

[0115] (12) In embodiment (12) is presented a polishing composition as in any one of embodiments (1) to (11), wherein the chemical mechanical polishing composition further comprises a non-ionic polymer.

[0116] (13) In embodiment (13) is presented a polishing composition as in embodiment (12), wherein the non-ionic polymer is selected from the group consisting of a polyalkylene glycol, a polyetheramine, a polyethylene oxide / polypropylene oxide copolymer, a polyacrylamide, a polyvinyl pyrrolidone, a siloxane polyalkylene oxide copolymer, a hydrophobically modified polyacrylate copolymer, a hydrophilic non-ionic polymer, a polysaccharide, and combinations thereof.

[0117] (14) In embodiment (14) is presented a polishing composition as in embodiment (12) or embodiment (13), wherein the non-ionic polymer is a polyvinyl pyrrolidone.

[0118] (15) In embodiment (15) is presented a polishing composition as in embodiment (12) or embodiment (13), wherein the non-ionic polymer is a polyalkylene glycol.

[0119] (16) In embodiment (16) is presented a polishing composition as in embodiment (12) or embodiment (13), wherein the non-ionic polymer is a polyethylene oxide / polypropylene oxide copolymer.

[0120] (17) In an embodiment (17) is presented a polishing composition as in any one of embodiments (1) to (16), wherein the cationic monomer compound is selected from the group consisting of 2-(dimethylamino)ethyl acrylate ("DMAEA"), 2-(dimethylamino)ethyl methacrylate ("DMAEM"), 3-(dimethylamino)propyl methacrylamide ("DMAPMA"), 3-(dimethylamino)propyl acrylamide ("DMAPA"), 3-methacrylamidopropyl-trimethylammonium chloride ("MAPTAC"), 3-acrylamidopropyl-trimethylammonium chloride ("APTAC"), diallyldimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylammonium ethyl chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylammonium ethyl chloride ("DMAEM.MCQ"), N,N-dimethylaminoethyl acrylate benzyl chloride ("DMAEA.BCQ"), N,N-dimethylaminoethyl methacrylate benzyl chloride ("DMAEM.BCQ"), salts thereof, and combinations thereof.

[0121] (18) In an embodiment (18) is presented a polishing composition as in any one of embodiments (1) to (17), wherein the cationic monomer compound is diallyldimethylammonium chloride ("DADMAC") or a salt thereof.

[0122] (19) In an embodiment (19) is presented a method of chemically mechanically polishing a substrate, comprising:

[0123] (i) providing a substrate,

[0124] (ii) providing a polishing pad,

[0125] (iii) providing a chemical mechanical polishing composition, the chemical mechanical polishing composition comprising:

[0126] (a) an abrasive selected from the group consisting of ceria abrasive, zirconia abrasive, and combinations thereof;

[0127] (b) a self-stoppage agent selected from the group consisting of compounds of Formula (I):

[0128]

[0129] wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocyclic aryl, each of which can be substituted or unsubstituted;

[0130] (c) a cationic monomer compound; and

[0131] (d) water,

[0132] wherein the pH of the polishing composition is from about 5.5 to about 8,

[0133] (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition, and

[0134] (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate, thereby polishing the substrate.

[0135] (20) In an embodiment (20) is presented a polishing composition as in embodiment (19), wherein the polishing composition comprises about 0.001 wt.% to about 10 wt.% of the abrasive.

[0136] (21) In an embodiment (21) is presented a polishing composition as in embodiment (19) or embodiment (20), wherein the polishing composition comprises about 0.05 wt.% to about 5 wt.% of the abrasive.

[0137] (22) In an embodiment (22) is presented a polishing composition as in any one of embodiments (19) to (21), wherein the abrasive is a ceria abrasive.

[0138] (23) In an embodiment (23) is presented a polishing composition as in any one of embodiments (19) to (21), wherein the abrasive is a zirconia abrasive.

[0139] (24) In an embodiment (24) is presented a polishing composition as in any one of embodiments (19) to (23), wherein the pH of the polishing composition is about 5.5 to about 7.

[0140] (25) In an embodiment (25) is presented a polishing composition as in any one of embodiments (19) to (24), wherein the pH of the polishing composition is about 6 to about 6.5.

[0141] (26) In an embodiment (26) is presented a polishing composition as in any one of embodiments (19) to (25), wherein the self-stop agent is selected from the group consisting of hydroxamic acid, acetyl hydroxamic acid, phenyl hydroxamic acid, salicyl hydroxamic acid, and combinations thereof.

[0142] (27) In an embodiment (27) is presented a polishing composition as in any one of embodiments (19) to (26), wherein the self-stop agent is hydroxamic acid.

[0143] (28) In an embodiment (28) is presented a polishing composition as in any one of embodiments (19) to (26), wherein the self-stop agent is phenyl hydroxamic acid.

[0144] (29) In an embodiment (29) is presented a polishing composition as in any one of embodiments (19) to (26), wherein the self-stop agent is salicyl hydroxamic acid.

[0145] (30) In an embodiment (30) is presented a polishing composition as in any one of embodiments (19) to (29), wherein the chemical mechanical polishing composition further comprises a non-ionic polymer.

[0146] (31) In an embodiment (31) is presented a method as in embodiment (30), wherein the non-ionic polymer is selected from the group consisting of polyalkylene glycols, polyether amines, polyethylene oxide / polypropylene oxide copolymers, polyacrylamides, polyvinylpyrrolidones, siloxane polyalkylene oxide copolymers, hydrophobically modified polyacrylate copolymers, hydrophilic non-ionic polymers, polysaccharides, and combinations thereof.

[0147] (32) In an embodiment (32) is presented a method as in embodiment (30) or embodiment (31), wherein the non-ionic polymer is a polyvinylpyrrolidone.

[0148] (33) In an embodiment (33) is presented a method as in embodiment (30) or embodiment (31), wherein the non-ionic polymer is a polyalkylene glycol.

[0149] (34) In an embodiment (34) is presented a method as in embodiment (30) or embodiment (31), wherein the non-ionic polymer is a polyethylene oxide / polypropylene oxide copolymer.

[0150] (35) In an embodiment (35) is presented a method as in any one of embodiments (19) to (34), wherein the cationic monomer compound is selected from the group consisting of 2-(dimethylamino)ethyl acrylate (“DMAEA”), 2-(dimethylamino)ethyl methacrylate (“DMAEM”), 3-(dimethylamino)propyl methacrylamide (“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”), 3-methacrylamidopropyl-trimethylammonium chloride (“MAPTAC”), 3-acrylamidopropyl-trimethylammonium chloride (“APTAC”), diallyldimethylammonium chloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylammonium ethyl chloride (“DMAEA.MCQ”), 2-(methacryloyloxy)-N,N,N-trimethylammonium ethyl chloride (“DMAEM.MCQ”), N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”), N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), salts thereof, and combinations thereof.

[0151] (36) In an embodiment (36) is presented a method as in any one of embodiments (19) to (35), wherein the cationic monomer compound is diallyldimethylammonium chloride (“DADMAC”) or a salt thereof.

[0152] (37) In an embodiment (37) is presented a method as in any one of embodiments (19) to (36), wherein the substrate comprises silicon oxide, and wherein at least a portion of the silicon oxide is abraded to polish the substrate.

[0153] (38) In an embodiment (38) is presented a method as in embodiment (37), wherein the substrate further comprises polysilicon, and wherein at least a portion of the polysilicon is abraded to polish the substrate.

[0154] (39) In an embodiment (39) is presented a method as in embodiment (38), wherein the substrate is polished to remove silicon oxide with a selectivity to polysilicon of greater than about 20: 1 as determined by angstroms removed per minute.

[0155] (40) In an embodiment (40) is presented a method as in embodiment (39), wherein the substrate is polished to remove silicon oxide with a selectivity to polysilicon of greater than about 40: 1 as determined by angstroms removed per minute.

[0156] Examples

[0157] The following examples further illustrate the application but, of course, should not be construed as in any way limiting its scope.

[0158] The following abbreviations are used throughout the examples: removal rate (RR); tetraethyl orthosilicate (TEOS); and polysilicon (polySi); polyethylene glycol (PEG); point of use (POU); and weight average molecular weight (MW).

[0159] In the following examples, substrates TEOS (i.e., silicon oxide) and / or polySi were coated on patterned wafers and polished using MIRRA TM (Applied Materials, Inc.) polishing tool, AP-300 TM (CTSCo., Ltd) polishing tool or REFLEXION TM (Applied Materials, Inc.) polishing tool. For all compositions, IC 1010 TM polishing pad (Rohm and Haas Electronic Materials) or NEXPLANAR TM E6088 polishing pad (Cabot Microelectronics, Aurora, IL) was used with the same polishing parameters. Unless otherwise noted, standard REFLEXION TM polishing parameters were as follows: IC 1010TM Pad, down force = 20.68 kPa (3 psi), head speed = 110 rpm, table speed = 120 rpm, total flow rate = 200 mL / min. Standard MIRRA TM Polishing parameters were as follows: IC1010 TM Pad, down force = 20.68 kPa (3 psi), head speed = 110 rpm, table speed = 120 rpm, total flow rate = 200 mL / min. Standard MIRRA TM Polishing parameters were as follows: IC1010 TM Pad, down force = 20.68 kPa (3 psi), head speed = 110 rpm, table speed = 120 rpm, total flow rate = 200 mL / min; or NEXPLANAR TM E6088 Pad, down force = 20.68 kPa (3 psi), head speed = 110 rpm, table speed = 120 rpm, total flow rate = 200 mL / min. Removal rate was calculated by measuring film thickness using spectroscopic elipsometry and subtracting the final thickness from the initial thickness.

[0160] Example 1

[0161] This example demonstrates the preparation of a polishing composition according to the present application containing: (a) ceria abrasive, zirconium oxide abrasive, or a combination thereof; (b) a stopper; (c) an optional non-ionic polymer; and (d) a cationic monomeric compound. Polishing compositions used in Examples 2-4 below were prepared using abrasive formulations Al and A2 and additive formulations Bl to B13 to demonstrate the efficiency of the claimed polishing method.

[0162] For each of the polishing compositions used in Examples 2-4, abrasive formulations Al and A2 were prepared using Hybrid-30 ceria particles (available from ANP Co., Ltd.) or zirconium oxide (available from Saint Gobain) and picolinic acid (500 ppm). The pH of the resulting mixture was adjusted to 4.2. The abrasive formulations are summarized in Table 1.

[0163] Table 1. Abrasive Formulations

[0164] Abrasive preparation Cerium oxide or zirconia (wt%) Picolinic acid (ppm) pH value A1 Hybrid-30 (0.29) 500 4.2 A2 Zirconium oxide (0.30) 500 4.2

[0165] For each of the polishing compositions used in Examples 2 through 4, diallyl dimethyl ammonium chloride (“DADMAC”) or poly(2-methacryloyloxyethyltrimethylammonium chloride”) (“polyMADQUAT”) is used as a cationic additive, phenyl hydroxamic acid or salicyl hydroxamic acid as a self-stopping agent, and polyvinylpyrrolidone (“PVP”), Brij TM S20 (available from Sigma Aldrich) or Pluronic TM L31 (available from Sigma Aldrich) is used as a nonionic polymer to prepare additive formulations B1 to B13. The additive formulations optionally further contain Bis-Tris. TM (Available from Sigma-Aldrich) as a buffer, and pH adjusted with nitric acid or triethanolamine (“TEA”). An overview of the additive formulation is shown in Table 2.

[0166] Table 2. Additive Formulation

[0167]

[0168] Example 2

[0169] This embodiment demonstrates the beneficial topographical selectivity provided by the polishing composition according to the invention, which contains (a) a cerium oxide abrasive, a zirconium oxide abrasive, or a combination thereof; (b) a self-stopping agent; (c) an optional nonionic polymer and (d) a cationic monomer compound.

[0170] It will contain 250μm TEOS features with a pattern density of 50% (approximately A single patterned wafer (200×300mm wafer) with a thickness of approximately On a patterned silicon substrate with stepped height, and using IC1010 TM Pads, using comparative polishing compositions 2A to 2D and the polishing compositions 2E to 2J of the present invention in Mirra TM or Reflexion TM Polishing was performed on the tool. The polishing compositions 2A to 2D and the polishing compositions 2E to 2J of the present invention were prepared by combining abrasive formulations and additive formulations in a 7:3 volume ratio. Active removal rate (active RR) and blanket removal rate (blanket RR) were measured, and the results are presented in Table 3.

[0171] Comparative polishing compositions 2A to 2D are different from the polishing compositions 2E to 2J of the present application because the polishing compositions 2E to 2J of the present application contain a cationic monomer compound.

[0172] Table 3. Polishing removal rates and topography selectivity

[0173]

[0174] As evident from Table 3, comparative polishing composition 2A, which contains ceria abrasive, a stopper (hydroxamic acid), and a pH of 4.2, exhibits a low active:blanket RR ratio. In other words, comparative polishing composition 2A, which does not contain a cationic monomer compound, exhibits limited selectivity between active and blanket removal rates.

[0175] Table 3 also shows that comparative polishing compositions 2B to 2D, which contain ceria abrasive, a stopper, and a cationic polymer, exhibit improved active:blanket RR ratios relative to comparative polishing composition 2A. However, as demonstrated by comparative polishing composition 2C, if the pH is not increased to 7.7, the active removal rate is significantly reduced (see comparative polishing compositions 2B and 2D).

[0176] In contrast, the polishing compositions 2E to 2J of the present application, which contain ceria abrasive, a stopper, and a cationic monomer compound, exhibit high active removal rates and high topography selectivity at a pH as low as 6.2. These results demonstrate the improved topography selectivity exhibited by the polishing compositions 2E to 2J of the present application relative to comparative polishing compositions 2A to 2D.

[0177] Example 3

[0178] This example demonstrates the effect on selectivity exhibited by the polishing compositions of the present application containing a non-ionic polymer.

[0179] Using IC1010 TM Pads were polished patterned substrates containing TEOS and polySi on Mirra TM or Reflexion TM tools using comparative polishing compositions 3A and 3B and the polishing compositions 3C to 3K of the present application. Comparative polishing compositions 3A and 3B and the polishing compositions 3C to 3K of the present application were prepared by combining 7:3 volume of abrasive formulation and additive formulation. Active removal rates (TEOS) and polySi removal rates were measured and the results are set forth in Table 4.

[0180] Comparative polishing compositions 3A and 3B and the polishing composition 3C of the present application are different from the polishing compositions 3D to 3K of the present application because the polishing compositions 3D to 3K of the present application contain a non-ionic polymer.

[0181] Table 4. Polishing removal rates and selectivity

[0182]

[0183] As evident from Table 4, the polishing compositions of the present application 3C to 3K containing (a) ceria abrasive or zirconia abrasive, (b) a self-stopping agent, and (c) a cationic monomeric compound exhibited higher active removal rates (i.e., TEOS removal rates) at the same pH (i.e., pH of 6.2) relative to comparative polishing composition 3A containing ceria abrasive, a self-stopping agent, and a cationic polymer. Polishing compositions 3H to 3K of the present application were so effective that the active removal rates (i.e., TEOS removal rates) were not measured.

[0184] Table 4 also shows that the addition of non-ionic polymers, such as polyvinylpyrrolidone ("PVP"), Brij TM S20 (commercially available from Sigma Aldrich), or Pluronic TM L31 (commercially available from Sigma Aldrich) significantly reduced the polySi removal rates without affecting the active removal rates (i.e., TEOS removal rates), as evidenced by the comparison of polishing compositions 3D to 3K of the present application with comparative polishing compositions 3A and 3B or polishing composition 3C of the present application. These results indicate that the polishing compositions according to the present application have high active removal rates (i.e., TEOS removal rates), and can be made selective for polishing TEOS over polishing polySi by the addition of non-ionic polymers without significantly reducing the TEOS removal rates.

[0185] Example 4

[0186] This example shows the effect on stability exhibited by the polishing compositions of the present application containing a cationic monomeric compound instead of a cationic polymer.

[0187] IC1010 TM pads with comparative polishing composition 4A and polishing compositions 4B and 4C of the present application were used to polish patterned substrates containing TEOS and polySi on Mirra TM or Reflexion TM tools. Comparative polishing composition 4A and polishing compositions 4B and 4C of the present application were prepared by combining 7:3 volume of abrasive formulation and additive formulation. The abrasive particle size before polishing and the abrasive particle size after polishing were measured, and the results are set forth in Table 5.

[0188] Comparative polishing composition 4A is different from the polishing compositions 4B and 4C of the present application because the polishing compositions 4B and 4C of the present application contain cationic monomer compounds instead of cationic polymers and have a lower pH value. Polishing was performed for 60 seconds using each polishing composition.

[0189] Table 5. Particle size after polishing

[0190]

[0191] As is clear from Table 5, the polishing compositions 4B and 4C of the present application, which contain diallyldimethylammonium chloride ("DADMAC") as a cationic monomer compound and have a pH value of 6.2, maintain the same particle size before and after polishing. In contrast, the comparative polishing composition 4A, which contains poly(2-methacryloyloxyethyltrimethylammonium chloride) ("polyMADQUAT") and has a pH value of 7.8, exhibits more than a 4-fold increase in particle size after polishing. These results indicate that polishing compositions containing cationic monomer compounds and having a lower pH value (e.g., from about 5.5 to about 7) are more stable than polishing compositions containing cationic polymers and having a higher pH value (e.g., about 7.5 and above).

[0192] All references cited herein, including publications, patent applications, and patents, are hereby incorporated by reference to the same extent as if each reference were individually and specifically incorporated by reference and were specifically stated to be incorporated by reference herein in its entirety.

[0193] The use of the terms "one" and "the" and "a" and "at least one" and similar referents in the context of describing the application (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term "at least one" followed by a list of one or more items (for example, "at least one of A and B") is to be construed to mean one item from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated in the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the application and does not pose a limitation on the scope of the application unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.

[0194] Preferred embodiments of this application are described herein, including the best mode known to the inventors of practicing the application. Variations of those preferred embodiments as would be obvious to those of ordinary skill in the art are not to be excluded from the scope of the application, which is defined by the claims. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors expect the application to be practiced otherwise than as specifically described herein. Accordingly, this application includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the elements described above in all possible variations thereof is encompassed by the application unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A chemical mechanical polishing composition comprising: (a) Abrasives selected from cerium oxide abrasives, zirconium oxide abrasives, and combinations thereof; (b) Self-stopping agents selected from compounds of formula (I): ， R is selected from: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl and heterocycloaryl, each of which may be substituted or unsubstituted; (c) cationic monomeric compounds; and (d) Water, The polishing composition has a pH value of 5.5 to 8, and The cationic monomer compound is selected from 2-(dimethylamino)ethyl acrylate ("DMAEA"), 2-(dimethylamino)ethyl methacrylate ("DMAEM"), 3-(dimethylamino)propylmethacrylamide ("DMAPMA"), 3-(dimethylamino)propylacrylamide ("DMAPA"), 3-methacryloylaminopropyltrimethylammonium chloride ("MAPTAC"), 3-acryloylaminopropyltrimethylammonium chloride ("APTAC"), diallyl dimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEM.MCQ"), N,N-dimethylaminoethyl acrylate benzyl chloride ("DMAEA.BCQ"), N,N-dimethylaminoethyl methacrylate benzyl chloride ("DMAEM.BCQ"), and combinations thereof.

2. The polishing composition of claim 1, wherein the polishing composition comprises 0.001% by weight to 10% by weight of the abrasive.

3. The polishing composition of claim 1, wherein the polishing composition comprises 0.05% by weight to 5% by weight of the abrasive.

4. The polishing composition of claim 1, wherein the abrasive is a cerium oxide abrasive.

5. The polishing composition of claim 1, wherein the pH value of the polishing composition is from 5.5 to 7.

6. The polishing composition of claim 5, wherein the pH value of the polishing composition is 6 to 6.

5.

7. The polishing composition of claim 1, wherein the self-stopping agent is selected from isohydroxamic acid, acetyl isohydroxamic acid, phenyl isohydroxamic acid, salicyl isohydroxamic acid, and combinations thereof.

8. The polishing composition of claim 7, wherein the self-stopping agent is phenylhydroxamic acid.

9. The polishing composition of claim 1, wherein the chemical mechanical polishing composition further comprises a nonionic polymer.

10. The polishing composition of claim 9, wherein the nonionic polymer is selected from polyalkylene glycols, polyetheramines, polyethylene oxide / polypropylene oxide copolymers, polyacrylamide, polyvinylpyrrolidone, siloxane polyalkylene oxide copolymers, hydrophobically modified polyacrylate copolymers, hydrophilic nonionic polymers, polysaccharides, and combinations thereof.

11. The polishing composition of claim 10, wherein the nonionic polymer is a polyethylene oxide / polypropylene oxide copolymer.

12. The polishing composition of claim 1, wherein the cationic monomer compound is selected from diallyl dimethyl ammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEM.MCQ"), and combinations thereof.

13. The polishing composition of claim 12, wherein the cationic monomer compound is diallyl dimethyl ammonium chloride ("DADMAC").

14. A method for chemically and mechanically polishing a substrate, comprising: (i) Provide a substrate. (ii) Provide polishing pads (iii) Providing a chemical mechanical polishing composition comprising: (a) Abrasives selected from cerium oxide abrasives, zirconium oxide abrasives, and combinations thereof; (b) Self-stopping agents selected from compounds of formula (I): ， R is selected from: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl and heterocycloaryl, each of which may be substituted or unsubstituted; (c) cationic monomeric compounds; and (d) Water, The polishing composition has a pH value of 5.5 to 8, and The cationic monomer compound is selected from 2-(dimethylamino)ethyl acrylate ("DMAEA"), 2-(dimethylamino)ethyl methacrylate ("DMAEM"), 3-(dimethylamino)propylmethacrylamide ("DMAPMA"), 3-(dimethylamino)propylacrylamide ("DMAPA"), 3-methacryloylaminopropyltrimethylammonium chloride ("MAPTAC"), 3-acryloylaminopropyltrimethylammonium chloride ("APTAC"), diallyl dimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEM.MCQ"), N,N-dimethylaminoethyl acrylate benzyl chloride ("DMAEA.BCQ"), N,N-dimethylaminoethyl methacrylate benzyl chloride ("DMAEM.BCQ"), and combinations thereof. (iv) Bring the substrate into contact with the polishing pad and the chemical mechanical polishing composition, and (v) The polishing pad and the chemical mechanical polishing composition are moved relative to the substrate to grind at least a portion of the substrate, thereby polishing the substrate.

15. The method of claim 14, wherein the polishing composition comprises 0.001% by weight to 10% by weight of the abrasive.

16. The method of claim 15, wherein the polishing composition comprises 0.05% by weight to 5% by weight of the abrasive.

17. The method of claim 14, wherein the abrasive is a cerium oxide abrasive.

18. The method of claim 14, wherein the pH of the polishing composition is from 5.5 to 7.

19. The method of claim 18, wherein the pH of the polishing composition is 6 to 6.

5.

20. The method of claim 14, wherein the self-stopping agent is selected from hydroxamic acid, acetyl hydroxamic acid, phenyl hydroxamic acid, salicyl hydroxamic acid, and combinations thereof.

21. The method of claim 20, wherein the self-stopping agent is phenylhydroxamic acid.

22. The method of claim 14, wherein the chemical mechanical polishing composition further comprises a nonionic polymer.

23. The method of claim 22, wherein the nonionic polymer is selected from polyalkylene glycols, polyetheramines, polyethylene oxide / polypropylene oxide copolymers, polyacrylamide, polyvinylpyrrolidone, siloxane polyalkylene oxide copolymers, hydrophobically modified polyacrylate copolymers, hydrophilic nonionic polymers, polysaccharides, and combinations thereof.

24. The method of claim 14, wherein the cationic monomer compound is selected from diallyl dimethyl ammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethylammonium chloride ("DMAEM.MCQ"), and combinations thereof.

25. The method of claim 24, wherein the cationic monomer compound is diallyl dimethyl ammonium chloride ("DADMAC").

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