Silicon carbonitride polishing composition and method

Abstract

A chemical-mechanical polishing composition for polishing a substrate including a silicon carbonitride layer, the composition comprising, consisting essentially of, or consisting of an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, a topography control agent, and having a pH within the range of about 2 to about 7.

Description

Technical Field

[0001] The disclosed embodiments relate to chemical mechanical polishing, and more particularly, to compositions and methods for polishing a substrate comprising a silicon carbonitride layer.

Background Art

[0002] Silicon carbonitride (SiCN) dielectrics are increasingly being used in semiconductor devices, such as, for example, as dielectric layers, diffusion barriers, and stop layers. The use of SiCN can provide a number of advantages, particularly as device sizes decrease. For example, SiCN generally has a lower dielectric constant than SiN, and thus the layer may be capable of having a lower capacitance.

[0003] One problem associated with the integration of SiCN is achieving appropriate chemical mechanical polishing (CMP) performance. For example, it can be a challenge to achieve an appropriate SiCN removal rate and to meet topography metrics. With the emergence of SiCN films in advanced semiconductor devices, polishing compositions and methods that provide both an appropriately high SiCN removal rate and appropriate topography control are sought in the art.

Summary of the Invention

[0004] A first chemical mechanical polishing composition for polishing a substrate comprising a silicon carbonitride layer is disclosed. The polishing composition comprises, consists essentially of, or consists of an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, bistris methane, and has a pH in the range of about 4 to about 7.

[0005] A second chemical mechanical polishing composition for polishing a substrate comprising a silicon carbonitride layer is disclosed. The polishing composition comprises, consists essentially of, or consists of an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, acetic acid, and has a pH in the range of about 2.5 to about 4.

[0006] A method for polishing a substrate containing a silicon carbonitride layer is further disclosed. The method may include polishing the wafer by bringing the wafer into contact with the first or second polishing composition described above (or any other composition disclosed herein), moving the polishing composition against the wafer, and abrading the wafer to remove the silicon carbonitride from the wafer. [Modes for carrying out the invention]

[0007] Chemical mechanical polishing compositions are disclosed. One polishing composition comprises, essentially or consisting of, an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, and bistrismethane, and has a pH in the range of about 4 to about 7. Another polishing composition comprises, essentially or consisting of, an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, and acetic acid, and has a pH in the range of about 2.5 to about 4. Methods using the disclosed compositions to polish silicon carbonitride-containing substrates are also disclosed.

[0008] The disclosed compositions and methods may offer various technical advantages and improvements compared to the prior art. For example, the disclosed compositions and methods may enable sufficiently high removal rates and improved topographic control during CMP operations of silicon carbonitride.

[0009] Abrasive compositions generally contain abrasive particles suspended in a liquid base. The liquid base is used to facilitate the application of the abrasive particles and any optionally included chemical additives to the surface of the substrate to be polished (e.g., planarized). The liquid base contains, preferably consists of, or is essentially composed of deionized water.

[0010] Abrasive particles may include silica particles (such as fumed silica particles and / or colloidal silica particles) dispersed in a liquid base. Preferred embodiments include colloidal silica particles. As used herein, the term colloidal silica particles means silica particles produced via a wet process rather than a heating or flame hydrolysis process used to produce fumed silica, which is a structurally different particle. Colloidal silica particles may be aggregated or not. Non-aggregated particles are individually separated particles that may be spherical or nearly spherical in shape, but may have other shapes (e.g., roughly elliptical, square, or rectangular cross-sections). Aggregated particles are particles in which multiple separated particles cluster or bond together to form aggregates that have an overall irregular shape. Aggregated colloidal silica particles are disclosed, for example, in U.S. Patent No. 9,309,442, assigned to the assignee of this application.

[0011] The most preferred embodiment advantageously includes anionic colloidal silica particles. "Anionic" means that the abrasive particles have a negative surface charge in the composition (e.g., at the pH of the composition). As is known to those skilled in the art, the charge on dispersed particles such as colloidal silica particles is commonly referred to in the art as the zeta potential (or interfacial potential). The zeta potential of a particle means the potential difference between the charge of ions surrounding the particle and the charge of the bulk solution of the abrasive composition (e.g., the liquid base and any other components dissolved therein). The zeta potential of a dispersion such as an abrasive composition can be obtained using commercially available instruments such as the Zetasizer® available from Malvern® Instruments, the ZetaPlus Zeta Potential Analyzer available from Brookhaven Instruments, and / or an ultrasonic spectrometer available from Dispersion Technologies, Inc.

[0012] In the disclosed abrasive compositions, the anionic colloidal silica may have a negative charge (negative zeta potential) of about 5 mV or more (e.g., about 10 mV or more, about 15 mV or more, or about 20 mV or more). The colloidal silica particles in the abrasive composition may have a negative charge of about 50 mV or less. For example, the abrasive particles may have a zeta potential in the range of about -5 to about -50 mV (e.g., about -10 to about -50 mV, about -15 to about -45, or about -20 to about -40).

[0013] Colloidal silica particles may be anionic in their natural state at the pH of the abrasive composition. In preferred embodiments, colloidal silica particles are made anionic at the pH of the abrasive composition by surface metal doping and / or chemical or partial surface treatment using, for example, organic acids, sulfur-based acids, phosphorus-based acids, and / or anionic polymers. Such treatment methods are known to those skilled in the art (e.g., as disclosed in U.S. Patent No. 9,382,450).

[0014] Abrasive particles may have substantially appropriate particle sizes. The particle size of particles suspended in a liquid base can be determined in the industry by various means. For example, particle size can be determined as the diameter of the smallest sphere containing the particles, and can be measured using numerous commercially available instruments, including, for example, the CPS Disc Centrifuge, Model DC24000HR (available from CPS Instruments, Prairieville, Louisiana) or the Zetasizer® available from Malvern Instruments®. Abrasive particles may have an average particle size of about 25 nm or more (e.g., about 30 nm or more, about 40 nm or more, about 50 nm or more, or about 60 nm or more). Abrasive particles may have an average particle size of about 150 nm or less (e.g., about 125 nm or less, about 100 nm or less, or about 80 nm or less). Thus, abrasive particles may have an average particle size within a range with any two of the above endpoints as boundary values. For example, the abrasive particles may have an average particle size in the range of about 25 nm to about 150 nm (e.g., about 30 nm to about 125 nm or about 40 nm to about 100 nm). A preferred embodiment has a particle size in the range of about 50 nm to about 100 nm (most preferred range is about 60 nm to about 80 nm).

[0015] The abrasive composition may contain substantially appropriate amounts of colloidal silica particles. At the time of use, the abrasive composition may contain about 0.1% by weight or more (e.g., about 0.2% by weight or more, about 0.5% by weight or more, about 1% by weight or more, or about 2% by weight or more) of colloidal silica particles. The abrasive composition may also contain about 20% by weight or less (e.g., about 10% by weight or less, about 8% by weight or less, about 6% by weight or less, or about 4% by weight or less) of colloidal silica particles at the time of use. Therefore, the amount of silica particles in the abrasive composition at the time of use may be within a range with any two of the above endpoints as boundary values. For example, the amount of colloidal silica particles in the abrasive composition may be in the range of about 0.1% by weight to about 20% by weight (e.g., about 0.5% by weight to about 10% by weight or about 0.5% by weight to about 8% by weight). A preferred embodiment has about 1% to about 6% by weight of colloidal silica particles (the most preferred embodiment has about 2% to about 4% by weight of colloidal silica particles at the time of use).

[0016] The first abrasive composition generally has a mild acidic or neutral pH of about 9 or less at the time of use (e.g., about 8 or less, about 7 or less, or about 6 or less). The abrasive composition may also have a pH of about 3 or more at the time of use (e.g., about 4 or more, or about 5 or more). Therefore, the pH at the time of use may be within a range with any two of the above endpoints as boundary values, for example, about 4 to about 8 (e.g., about 4 to about 7 or about 5 to about 6). In a preferred embodiment, the pH is in the range of about 5 to about 6 (and most preferably about 5.5).

[0017] The second abrasive composition is acidic, having a pH of less than about 7 at the time of use (e.g., about 6 or less, about 5 or less, or about 4 or less). The abrasive composition may also have a pH of about 1 or more at the time of use (e.g., about 2 or more, or about 3 or more). Therefore, the pH at the time of use may be within a range with any two of the above endpoints as boundary values, for example, about 2 to about 6 (e.g., about 2 to about 5 or about 2.5 to about 4). In a preferred embodiment, the pH is in the range of about 3 to about 4 (and most preferably about 3.5).

[0018] The abrasive composition may optionally contain a pH adjuster, such as potassium hydroxide, ammonium hydroxide, and / or nitric acid (for example, depending on the desired pH). The abrasive composition may also optionally contain a pH buffer system, many of which are known in the art. The abrasive composition may contain any appropriate amount of pH adjuster and / or pH buffer (in either the concentrate or the composition at the time of use, or both) for the purpose of achieving and / or maintaining the desired pH. The second abrasive composition may, advantageously, contain acetic acid.

[0019] The disclosed polishing compositions further comprise a topography control agent. In preferred embodiments, the topography control agent is a tertiary amine (a compound in which a nitrogen atom is directly bonded to three carbon atoms). The most preferred topography control agent is bistrismethane (also referred to herein as bistris). Surprisingly, it has been found that the use of bistrismethane can improve the SiCN removal rate and also significantly improve topography control during CMP work. Acetic acid has also been found to be a suitable topography control agent in certain acidic embodiments (e.g., having a pH in the range of about 2.5 to about 4).

[0020] The disclosed embodiments may include any substantially appropriate amount of a topography control agent (e.g., bistrismethane). The polishing composition may contain at least about 50 ppm by weight of the topography control agent at the time of use (e.g., at least about 100 ppm, at least about 200 ppm, at least about 400 ppm, or at least about 600 ppm). The polishing composition may also contain at least about 5000 ppm by weight of the topography control agent at the time of use (e.g., at least about 2000 ppm, at least about 1600 ppm, at least about 1400 ppm, or at least about 1200 ppm). Therefore, the amount of the topography control agent in the polishing composition at the time of use may be within a range with any two of the above endpoints as boundary values. For example, the amount of topography control agent in the polishing composition may be in the range of about 50 ppm by weight to about 5000 ppm by weight (e.g., about 100 ppm to about 2000 ppm, about 200 ppm to about 1600 ppm, about 400 ppm to about 1400 ppm, or about 600 ppm to about 1200 ppm).

[0021] The abrasive composition may further contain a biocide, if desired. The biocide may be any suitable biocide, such as isothiazolinone biocides. The amount of biocide in the abrasive composition is typically in the range of about 1 ppm to about 50 ppm, preferably about 1 ppm to about 20 ppm, at the time of use or in the concentrate.

[0022] Abrasive compositions may be manufactured using any suitable technique, many of which are known to those skilled in the art. Abrasive compositions may be manufactured by batch or continuous processes. Generally, abrasive compositions may be manufactured by combining their components in any order. The term "components," as used herein, includes individual raw materials (e.g., silica particles, topography control agents, and any other compounds that may be included as desired).

[0023] For example, a topography control agent may be added directly to a dispersion containing suspended silica abrasive. The components may be blended together using any appropriate technique to achieve sufficient mixing. Such blending / mixing techniques are known to those skilled in the art. The abrasive composition may be supplied as a one-package system, advantageously containing colloidal silica having the physical properties described above and other components that may be included as desired.

[0024] The abrasive compositions of the present invention may also be provided as concentrates intended to be diluted with an appropriate amount of water before use. In such embodiments, the abrasive composition concentrate may contain abrasive particles, a topography control agent, and other components that may be optionally included, in amounts such that each component of the abrasive composition is present in the abrasive composition in the appropriate range described above relative to each component after the concentrate has been diluted with an appropriate amount of water. For example, each component may be present in the abrasive composition in an amount about twice (e.g., about three times, about four times, about five times, or about ten times) more than the concentration at the time of use described above relative to each component, so that each component is present in the abrasive composition in the appropriate range described above relative to each component when the concentrate has been diluted with an equal volume (or mass) of water (e.g., two equal volumes (or mass) of water, three equal volumes (or mass) of water, four equal volumes (or mass) of water, or nine equal volumes (or mass) of water). Furthermore, as will be understood by those skilled in the art, the concentrate may contain an appropriate proportion of water present in the final polishing composition for the purpose of ensuring that other components are at least partially or completely dissolved in the concentrate.

[0025] In one exemplary embodiment, the polishing concentrate may comprise an aqueous liquid base, at least 10 wt percent of anionic silica particles, and bistrismethane as a topography control agent, and may have a pH in the range of about 4 to about 7 (or about 5 to about 6). The polishing concentrate may be diluted with deionized water before use to obtain a polishing composition containing appropriate concentrations of anionic silica particles and bistrismethane.

[0026] In another exemplary embodiment, the polishing concentrate may include an aqueous liquid base, at least 10 weight percent anionic silica particles, acetic acid, and may have a pH in the range of about 2.5 to about 4 (or about 3 to about 4). The polishing concentrate may be diluted with deionized water prior to use to obtain a polishing composition containing an appropriate concentration of anionic silica particles.

[0027] The polishing method of the present invention is particularly suitable for use in combination with a chemical mechanical polishing (CMP) apparatus. Typically, the apparatus includes a platen that operates during use and has a velocity resulting from orbital, linear, or circular motion, a polishing pad in contact with the platen and moving with the platen during operation, and a carrier that holds a substrate to be polished by contacting and moving relative to the surface of the polishing pad. Polishing of the substrate is performed by disposing the substrate in contact with the polishing pad and the polishing composition of the present invention, and then moving the polishing pad relative to the silicon carbonitride layer on the substrate so as to abrade at least a portion of the silicon carbonitride layer, thereby polishing the substrate.

[0028] The substrate may be planarized or polished using any suitable polishing pad (e.g., polishing surface) with the chemical mechanical polishing composition. Suitable polishing pads include, for example, woven and non-woven polishing pads. Further, suitable polishing pads may include any suitable polymer having various densities, hardnesses, thicknesses, compressibilities, abilities to rebound upon compression, and compression coefficients. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, co-formed products thereof, and mixtures thereof.

[0029] It is understood that the present disclosure includes numerous embodiments. These embodiments include, but are not limited to, the following embodiments.

[0030] In the first embodiment, the chemical mechanical polishing composition for polishing the silicon carbonitride layer comprises an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, bistrismethane, and a pH in the range of about 4 to about 7.

[0031] The second embodiment may include the first embodiment, wherein the anionic colloidal silica particles have a zeta potential greater than about -10 in the polishing composition.

[0032] A third embodiment may include any one of the first and second embodiments and may contain about 1 weight percent to about 6 weight percent of anionic colloidal silica abrasive particles.

[0033] The fourth embodiment may include any one of the first to third embodiments and contains about 2% to 4% by weight of anionic colloidal silica abrasive particles.

[0034] The fifth embodiment may include any one of the first to fourth embodiments, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm.

[0035] The sixth embodiment may include any one of the first to fifth embodiments, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm.

[0036] The seventh embodiment may include any one of the first to sixth embodiments and contains approximately 200 ppm by weight to approximately 2000 ppm by weight of bistrismethane.

[0037] The eighth embodiment may include any one of the first to seventh embodiments and contains approximately 600 ppm by weight to approximately 1200 ppm by weight of bistrismethane.

[0038] The ninth embodiment may include any one of the first to eighth embodiments and has a pH of about 5 to about 6.

[0039] The tenth embodiment may comprise any one of the first to ninth embodiments and comprises about 1% to about 6% by weight anionic colloidal silica abrasive particles and about 200 ppm to about 2000 ppm by weight bistrismethane, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm.

[0040] The eleventh embodiment may comprise any one of the first to tenth embodiments and comprises about 2% to about 4% by weight anionic colloidal silica abrasive particles, about 600 ppm to about 1200 ppm by weight bistrismethane, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm, and the composition has a pH of about 5 to about 6.

[0041] In the twelfth embodiment, the chemical mechanical polishing composition for polishing the silicon carbonitride layer comprises an aqueous liquid base, anionic colloidal silica particles dispersed in the liquid base, acetic acid, and a pH in the range of about 2.5 to about 4.

[0042] The thirteenth embodiment may include the twelfth embodiment, wherein the anionic colloidal silica particles have a zeta potential greater than about -10 in the polishing composition.

[0043] The fourteenth embodiment may include one of the twelfth and thirteenth embodiments and contains about 1 weight percent to about 6 weight percent of anionic colloidal silica abrasive particles.

[0044] The fifteenth embodiment may include any one of the twelfth to fourteenth embodiments and contains about 2% to 4% by weight of anionic colloidal silica abrasive particles.

[0045] The sixteenth embodiment may include any one of the twelfth to fifteenth embodiments, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm.

[0046] The seventeenth embodiment may include any one of the twelfth to sixteenth embodiments, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm.

[0047] The eighteenth embodiment may include any one of the twelfth to seventeenth embodiments and has a pH of about 3 to about 4.

[0048] The nineteenth embodiment may include any one of the twelveth to eighteenth embodiments and comprises about 1% to about 6% by weight of anionic colloidal silica abrasive particles, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm.

[0049] The 20th embodiment may comprise any one of the 12th to 19th embodiments and comprises about 2% to about 4% by weight of anionic colloidal silica abrasive particles, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm, and the composition has a pH of about 3 to about 4.

[0050] In the 21st embodiment, a method for chemically and mechanically polishing a substrate having at least one silicon carbonitride layer comprises (a) bringing the substrate into contact with any one of the polishing compositions disclosed in the first to 20th embodiments, (b) moving the polishing composition with respect to the substrate, and (c) abrading the substrate to remove a portion of the silicon carbonitride layer from the substrate, thereby polishing the substrate.

[0051] The following examples further illustrate the present invention, but should not be construed as limiting the scope of the invention in any way. [Examples]

[0052] Example 1 This example demonstrates the effect of the packing amount and average size of anionic colloidal silica particles on the removal rate of SiCN and silicon dioxide. In this example, six polishing compositions were evaluated. Each polishing composition contained anionic colloidal silica particles, 1500 ppm by weight of acetic acid, and 75 ppm of Kordex MLX biocide at a pH of 3.5. The anionic colloidal silica particles had a zeta potential of -36 to -39 mV in the composition. The average particle size of colloidal silica in compositions 1A and 1D was 70 nm. The average particle size of colloidal silica in compositions 1B and 1E was 100 nm. The average particle size of colloidal silica in compositions 1C and 1F was 120 nm. Compositions 1A to 1C contained 1% by weight of anionic colloidal silica, while compositions 1D to 1F contained 6% by weight of anionic colloidal silica.

[0053] SiCN wafers and FCVD silicon oxide wafers (available from Silyb) were polished on a GNP POLI-500 polishing apparatus for 60 seconds at a platen speed of 113 rpm, a head speed of 87 rpm, a downward force of 2 psi (approximately 13.8 kPa), and a slurry flow rate of 150 ml / min. The removal rates of blanket SiCN and FCVD oxides are shown in Table 1. Table 1 [Table 1]

[0054] As is readily apparent from the results shown in Table 1, the highest SiCN removal rate and the highest SiCN-to-FCVD Ox selectivity were achieved by using colloidal silica with an average particle size of 70 nm. In this composition, the SiCN removal rate was largely unaffected by the silica content, but the selectivity for FCVD Ox clearly increased with increasing silica content.

[0055] Example 2 This example demonstrates the effect of pH and additive type on the removal rate of SiCN and silicon dioxide. In this example, nine polishing compositions were evaluated. Each polishing composition contained 1 wt percent anionic colloidal silica particles with an average particle size of 70 nm and 100 ppm of Kordex MLX biocide. Compositions 2A-2E further contained 1500 wt ppm of acetic acid. Compositions 2F-2I further contained 872 wt ppm of bistrismethane. The pH values ​​of the compositions were in the range of 2.3-7, as shown in Table 2. The anionic colloidal silica particles had a zeta potential of -36--39 mV in the compositions.

[0056] SiCN wafers and FCVD silicon oxide wafers were polished on a GNP POLI-500 polishing apparatus for 60 seconds at a platen speed of 113 rpm, a head speed of 87 rpm, a downward force of 1 psi (approximately 6.89 kPa), and a slurry flow rate of 150 ml / min. The removal rates of blanket SiCN and FCVD oxides are shown in Table 2. Table 2 [Table 2]

[0057] As is readily apparent from the data shown in Table 2, the SiCN removal rate decreases overall with increasing pH. Compositions containing bistrismethane were also observed to have improved SiCN removal rates, reduced FCVD oxide removal rates, and significantly improved SiCN:FCVD selectivity compared to compositions containing acetic acid (particularly at pH 5.5 and 6).

[0058] Example 3 This example demonstrates the effectiveness of the disclosed compositions on the erosion performance of patterned wafers. In this example, eight polishing compositions were evaluated. Compositions 3A to 3H were the same as compositions 2A to 2H in Example 2 described above.

[0059] For compositions 3A to 3E, SiCN patterned wafers were polished for 120 seconds, followed by over-polishing for an additional 30 seconds to achieve complete removal from the wafer. For compositions 3F to 3H, SiCN patterned wafers were polished for 120 seconds, followed by over-polishing for an additional 120 seconds to achieve complete removal from the wafer. Polishing was performed on a GNP POLI-500 polishing apparatus with a platen speed of 113 rpm, a head speed of 87 rpm, a downward force of 1 psi (approximately 6.89 kPa), and a slurry flow rate of 150 ml / min. Oxide erosion was evaluated at several locations of varying pitches and widths (locations 1, 2, 3, and 4 in Table 3). The oxide erosion performance at each location is summarized on an A, B, and C scale, where A represents the lowest erosion (most desirable performance), C represents the highest erosion (least desirable performance), and B represents the intermediate range of performance. Table 3 [Table 3]

[0060] As is evident from the results shown in Table 3, compositions 3F, 3G, and 3H containing the topography control agent bistrismethane consistently achieved excellent oxide erosion performance. Furthermore, from Examples 2 and 3, it is clear that compositions 3F, 3G, and 3H (2F, 2G, and 2H) are superior in that they provide high SiCN removal rates, low FCVD oxide removal rates, and most preferred topography. Furthermore, compositions 3B and 3C were also observed to achieve preferred erosion performance. Furthermore, from Examples 2 and 3, it is clear that compositions 3B and 3C (2B and 2C) also provide high SiCN removal rates in addition to preferred topography. Given the high removal rates achieved with these compositions, it is understood that compositions 3B and 3C may advantageously provide process flexibility, and that erosion performance can be further improved by adjusting various process parameters (such as platen speed and downward force).

[0061] In the context describing this invention (particularly in the context of the following claims), the terms “a,” “an,” “the,” and similar referents should be interpreted as including both singular and plural, unless otherwise indicated herein or unless clearly inconsistent with the context. The terms “comprising,” “having,” “including,” and “containing” should be interpreted as non-restrictive terms (i.e., “including, but not limited to”), unless otherwise indicated herein. The enumeration of value ranges herein is intended merely as a concise way to refer individually to each of the separate values ​​contained within that range, unless otherwise indicated herein, and each of the separate values ​​is incorporated herein as if it were individually enumerated herein. All methods described herein may be performed in any appropriate order, unless otherwise indicated herein or unless clearly inconsistent with the context. The use of any examples or illustrative language provided herein (e.g., "etc.") is solely intended to better illustrate the invention and, unless otherwise claimed, does not limit the scope of the invention. No language herein should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0062] Preferred embodiments of the present invention are described herein, including the best modes known to the inventors for carrying out the invention. Variations of these preferred embodiments will become apparent to those skilled in the art by reading the foregoing description. The inventors expect that those skilled in the art will appropriately utilize such variations, and they intend that the invention may be carried out in ways other than those specifically described herein. Accordingly, the invention includes all modifications and equivalents of the subject matter described in the claims appended herein, where permitted by applicable law. Furthermore, any combination of the above elements, with respect to all conceivable variations thereof, is incorporated into the invention unless otherwise shown herein or unless it is clearly inconsistent with the context. The following embodiments can be cited as examples of the present invention. (Note 1) A chemical mechanical polishing composition for polishing a silicon carbonitride layer, aqueous liquid base, Anionic colloidal silica particles dispersed in the liquid base, Bistrismethane, and pH in the range of approximately 4 to 7. A composition containing the following: (Note 2) The composition according to Appendix 1, wherein the anionic colloidal silica particles have a zeta potential greater than about -10 in the polishing composition. (Note 3) The composition according to Appendix 1, comprising approximately 1% to approximately 6% by weight of the anionic colloidal silica abrasive particles. (Note 4) The composition according to Appendix 1, comprising approximately 2% to 4% by weight of the anionic colloidal silica abrasive particles. (Note 5) The composition according to Appendix 1, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm. (Note 6) The composition according to Appendix 1, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm. (Note 7) The composition described in Appendix 1, comprising approximately 200 ppm by weight to approximately 2000 ppm by weight of the bistrismethane. (Note 8) The composition according to Appendix 1, comprising approximately 600 ppm by weight to approximately 1200 ppm by weight of the bistrismethane. (Note 9) The composition described in Appendix 1, having a pH of approximately 5 to approximately 6. (Note 10) Approximately 1 weight percent to approximately 6 weight percent of the anionic colloidal silica abrasive particles, The bistrismethane in a concentration of approximately 200 ppm by weight to approximately 2000 ppm by weight, Includes, The composition according to Appendix 1, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm. (Note 11) Approximately 2% to 4% by weight of the anionic colloidal silica abrasive particles, The bistrismethane in a concentration of approximately 600 ppm by weight to approximately 1200 ppm by weight, Includes, The anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm, and The composition according to Appendix 1, wherein the composition has a pH of about 5 to about 6. (Note 12) A chemical mechanical polishing composition for polishing a silicon carbonitride layer, aqueous liquid base, Anionic colloidal silica particles dispersed in the liquid base, Acetic acid, and pH within the range of approximately 2.5 to 4. A composition containing the following: (Note 13) The composition according to Appendix 12, wherein the anionic colloidal silica particles have a zeta potential greater than about -10 in the polishing composition. (Note 14) The composition according to Appendix 12, comprising approximately 1 weight percent to approximately 6 weight percent of the anionic colloidal silica abrasive particles. (Note 15) The composition according to Appendix 12, comprising approximately 2% to 4% by weight of the anionic colloidal silica abrasive particles. (Note 16) The composition according to Appendix 12, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm. (Note 17) The composition according to Appendix 12, wherein the anionic colloidal silica abrasive particles have an average particle size in the range of about 60 to about 80 nm. (Note 18) The composition described in Appendix 12, having a pH of approximately 3 to approximately 4. (Note 19) Approximately 1 weight percent to approximately 6 weight percent of the anionic colloidal silica abrasive particles, The composition according to Appendix 12, wherein the anionic colloidal silica abrasive particles have an average particle size of less than 100 nm. (Note 20) Approximately 2% to 4% by weight of the anionic colloidal silica abrasive particles, The anionic colloidal silica abrasive particles include having an average particle size in the range of about 60 to about 80 nm, and The composition according to Appendix 12, wherein the composition has a pH of about 3 to about 4. (Note 21) A method for chemically and mechanically polishing a substrate having at least one silicon carbonitride layer, (a) The substrate is brought into contact with the polishing composition described in Appendix 1. (b) Moving the polishing composition with respect to the substrate, and (c) abrading the substrate to remove a portion of the silicon carbonitride layer from the substrate, thereby polishing the substrate. Methods that include... (Note 22) A method for chemically and mechanically polishing a substrate having at least one silicon carbonitride layer, (a) The substrate is brought into contact with the polishing composition described in Appendix 12. (b) Moving the polishing composition with respect to the substrate, and (c) abrading the substrate to remove a portion of the silicon carbonitride layer from the substrate, thereby polishing the substrate. Methods that include...

Claims

1. A chemical mechanical polishing composition for polishing a silicon carbonitride layer, aqueous liquid base, Anionic colloidal silica particles dispersed in the liquid base, the anionic colloidal silica abrasive particles having an average particle size in the range of about 60 to about 80 nm. Bistrismethane, and pH in the range of approximately 5 to 6. A composition containing the following:

2. The composition according to claim 1, wherein the anionic colloidal silica particles have a zeta potential greater than about -10 mV in the polishing composition.

3. The composition according to claim 1, comprising approximately 1% by weight to approximately 6% by weight of the anionic colloidal silica abrasive particles.

4. The composition according to claim 1, comprising approximately 2% to approximately 4% by weight of the anionic colloidal silica abrasive particles.

5. The composition according to claim 1, comprising approximately 200 ppm by weight to approximately 2000 ppm by weight of bistrismethane.

6. The composition according to claim 1, comprising approximately 600 ppm by weight to approximately 1200 ppm by weight of bistrismethane.

7. Approximately 1 weight percent to approximately 6 weight percent of the anionic colloidal silica abrasive particles, The bistrismethane in a concentration of approximately 200 ppm by weight to approximately 2000 ppm by weight, The composition according to claim 1, comprising:

8. Approximately 2% to 4% by weight of the anionic colloidal silica abrasive particles, The bistrismethane in a concentration of approximately 600 ppm by weight to approximately 1200 ppm by weight, The composition according to claim 1, comprising:

9. A method for chemically and mechanically polishing a substrate having at least one silicon carbonitride layer, (a) The substrate is brought into contact with the polishing composition described in claim 1. (b) Moving the polishing composition with respect to the substrate, and (c) Abrading the substrate to remove a portion of the silicon carbonitride layer from the substrate, thereby polishing the substrate. Methods that include...

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