Polishing composition and method for selectively removing silicon nitride

Abstract

To provide a polishing composition and a method for selectively removing silicon nitride by use of the polishing composition.SOLUTION: A polishing composition contains abrasive particles and at least one glucose derivative and has a pH of less than 3. The inventive polishing composition can achieve the effect of efficiently and selectively removing silicon nitride.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polishing composition capable of selectively removing silicon nitride, and a method for selectively removing silicon nitride using the polishing composition. [Background technology]

[0002] In today's semiconductor industry, the development of semiconductor manufacturing process technology is constantly progressing. In recent years, as the requirements for wafer surface quality have become increasingly stringent, higher levels of smoothness and flatness are also required in wafer polishing. It is already known that chemical mechanical polishing (hereinafter referred to as "CMP") can improve wafer surface quality.

[0003] For example, Patent Document 1 discloses a composition for polishing bare silicon wafers, which contains abrasive particles, a basic compound, and two or more water-soluble polymers and has a pH of 8 to 12. The two or more water-soluble polymers have different affinities for the silicon wafer and can act on the relatively inner and outer regions of the wafer during polishing. This allows the composition of Patent Document 1 to achieve the goal of controlling the wafer shape at a higher level while maintaining the polishing rate.

[0004] Patent Document 2 discloses a CMP composition containing cerium oxide (CeO2) abrasive particles, glucoside, and water, and having a pH of 3 to 9. The composition of Patent Document 2 has the effect of being able to selectively remove silicon dioxide relative to polysilicon or silicon nitride.

[0005] Patent Document 3 discloses a method for manufacturing silicon wafers. The polishing slurry used in this manufacturing method contains abrasive particles, a water-soluble polymer, and a pH adjuster (pH adjuster), and has a pH of 9 to 12. Patent Document 3 also discloses a liquid composition for storing silicon wafers after polishing and before cleaning, which can prevent abrasive particles from being fixed to the wafer surface during this period and becoming difficult to remove in the cleaning process. An alkyl polyglucoside may be added to the liquid composition.

[0006] Patent Document 4 discloses a polishing composition containing abrasive particles, a water-soluble alkaline compound, a water-soluble polymer, an (alkyl)glucoside, and water. The composition of Patent Document 4 can reduce the haze value of wafers, improve the surface quality of wafers, and impart appropriate wettability to wafers.

[0007] Patent Document 5 discloses a metal polishing liquid containing abrasive particles, an organic acid, a heterocyclic compound, and an alkyl (poly)glucoside, and having a pH of 3 to 10. This polishing liquid has a rapid polishing rate and high polishing precision, and does not cause dishing even when used on high-purity materials, so it can suppress corrosion in fine wiring and also improve flatness. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2018 / 124230 [Patent Document 2] International Publication No. 2013 / 035034 [Patent Document 3] Japanese Patent Application Publication No. 2019-121795 [Patent Document 4] Japanese Patent Application Publication No. 2018-206956 [Patent Document 5] Japanese Patent Application Laid-Open No. 2010-129941 Summary of the Invention [Problem to be solved by the invention]

[0009] Semiconductor wafers may contain various components such as polysilicon, silicon oxide, and silicon nitride. Compared to silicon nitride, polysilicon and silicon oxide (silicon dioxide) are softer and generally react more readily with abrasives. While Patent Documents 1 to 5 above can improve the surface characteristics of the object to be polished, such as flatness and haze, and can achieve selective removal of silicon dioxide, selective removal of silicon nitride has not yet been investigated.

[0010] In view of the above, an object of the present invention is to provide a polishing composition and method capable of selectively removing silicon nitride. [Means for solving the problem]

[0011] As a result of extensive research, the inventors of the present application have found that the above problems can be solved by the following embodiments of the present invention (which are merely illustrative and not limiting).

[0012] The polishing composition according to the first embodiment of the present invention contains abrasive particles and at least one glucose derivative, and has a pH of less than 3.

[0013] A polishing composition according to a second embodiment of the present invention is the polishing composition according to the first embodiment, and contains at least two types of glucose derivatives.

[0014] A polishing composition according to a third embodiment of the present invention is the polishing composition of the first or second embodiment, wherein the glucose derivative has an alkyl chain.

[0015] A polishing composition according to a fourth embodiment of the present invention is the polishing composition according to any one of the first to third embodiments, wherein the glucose derivative has an oxyalkylene side chain.

[0016] A polishing composition according to a fifth embodiment of the present invention is the polishing composition according to any one of the first to fourth embodiments, wherein the abrasive particles are colloidal silica.

[0017] A polishing composition according to a sixth embodiment of the present invention is the polishing composition according to the fifth embodiment, wherein the colloidal silica is sulfonic acid-fixed colloidal silica.

[0018] A polishing composition according to a seventh embodiment of the present invention is the polishing composition according to any one of the first to sixth embodiments, and further contains a chelating agent.

[0019] The polishing composition according to an eighth embodiment of the present invention is the polishing composition according to the seventh embodiment, wherein the chelating agent is a phosphonate chelating agent.

[0020] A polishing composition according to a ninth embodiment of the present invention is the polishing composition according to any one of the first to eighth embodiments, and further contains a pH adjuster.

[0021] A method for selectively removing silicon nitride according to the tenth embodiment of the present invention is a method using the polishing composition according to any one of the first to ninth embodiments.

[0022] The surface treatment method according to the eleventh embodiment of the present invention is a surface treatment method including a step of performing surface treatment on an object to be treated using the polishing composition according to any one of the first to ninth embodiments.

[0023] A surface treatment method according to a twelfth embodiment of the present invention is the surface treatment method according to the eleventh embodiment, wherein the object to be treated contains at least silicon nitride.

[0024] A surface treatment method according to a thirteenth embodiment of the present invention is the surface treatment method according to the eleventh or twelfth embodiment, wherein the surface treatment is at least one selected from a planarization treatment, a selective removal treatment, and a cleaning treatment.

[0025] The surface treatment apparatus according to the fourteenth embodiment of the present invention is a surface treatment apparatus including a mechanism for performing surface treatment on an object to be treated using the polishing composition according to any one of the first to ninth embodiments.

[0026] A surface treatment device according to a fifteenth embodiment of the present invention is the surface treatment device according to the fourteenth embodiment, wherein the object to be treated contains at least silicon nitride.

[0027] A surface treatment apparatus according to a sixteenth embodiment of the present invention is the surface treatment apparatus according to the fourteenth or fifteenth embodiment, wherein the surface treatment is at least one selected from a planarization treatment, a selective removal treatment, and a cleaning treatment.

[0028] A semiconductor manufacturing method according to the seventeenth embodiment of the present invention is a semiconductor manufacturing method including a step using the surface treatment apparatus according to any one of the fourteenth to sixteenth embodiments.

[0029] A semiconductor manufacturing facility according to an eighteenth embodiment of the present invention is a semiconductor manufacturing facility including the surface treatment device according to any one of the fourteenth to sixteenth embodiments.

[0030] Use according to the 19th embodiment of the present invention is use of the polishing composition of any one of the 1st to 9th embodiments for surface treatment.

[0031] The use according to the twentieth embodiment of the present invention is the use according to the nineteenth embodiment, wherein the object to be treated by the surface treatment includes at least silicon nitride.

[0032] A use according to a 21st embodiment of the present invention is the use according to the 19th or 20th embodiment, wherein the surface treatment is at least one selected from a planarization treatment, a selective removal treatment, and a cleaning treatment. [Effects of the Invention]

[0033] According to the present invention, a polishing composition and method capable of selectively removing silicon nitride can be provided. Furthermore, in some embodiments, a polishing composition and method capable of selectively removing silicon nitride relative to polysilicon can be provided. Specifically, polishing using the polishing composition of these embodiments can increase the removal rate of silicon nitride and decrease the removal rate of polysilicon, thereby effectively removing silicon nitride. Furthermore, since the removal rate of polysilicon can be significantly decreased, the effect of minimizing damage to polysilicon is also expected. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a schematic view illustrating the principle of action of a chelating agent in a polishing composition according to a seventh embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, embodiments of the present invention will be described in detail. "X~Y" means "X or more, Y or less." When multiple "X~Y" are listed, for example, "X1~Y1 or X2~Y2," the disclosure of each numerical value as an upper limit, the disclosure of each numerical value as a lower limit, and combinations of these upper and lower limits are all disclosed (i.e., legal basis for correction). Specifically, corrections of X1 or more, corrections of Y2 or less, corrections of X1 or less, corrections of Y2 or more, corrections of X1~X2, and corrections of X1~Y2 must all be considered legal. Unless otherwise specified, operations and measurements of physical properties, etc., are performed at room temperature (20~25°C) and a relative humidity of 40~50% RH.

[0036] [Polishing composition] The polishing composition of the present invention contains abrasive particles and at least one glucose derivative, and has a pH of less than 3.

[0037] [Abrasive particles] The material and shape of the abrasive particles of the present invention may be appropriately selected depending on the purpose and usage form of the polishing composition. The abrasive particles of the present invention may be at least one of inorganic particles, organic particles, or organic-inorganic composite particles. Examples of inorganic particles include oxide particles such as silica particles, alumina particles, cerium oxide particles, chromium oxide particles, titanium dioxide particles, zirconia particles, magnesium oxide particles, manganese dioxide particles, zinc oxide particles, and iron oxide (e.g., Fe3O2) particles, nitride particles such as silicon nitride particles and boron nitride particles, carbide particles such as silicon carbide particles and boron carbide particles, diamond particles, and carbonates such as calcium carbonate and barium carbonate. Examples of organic particles include polymethyl methacrylate (PMMA) particles, polyacrylic acid particles, polymethacrylic acid particles, and polyacrylonitrile particles. The above abrasive particles may be used alone or in combination of two or more.

[0038] In one embodiment of the present invention, the abrasive particles preferably contain silica particles, more preferably colloidal silica (colloidal silica particles). When the abrasive particles contain silica particles, the mass ratio of the silica particles to the entire abrasive particles is 80 mass% or more, 90 mass% or more, 95 mass% or more, 96 mass% or more, 97 mass% or more, 98 mass% or more, 99 mass% or more, or 100 mass%.

[0039] The colloidal silica that can be used in the present invention may be any that is commonly used in the technical field of CMP. Examples include colloidal silica prepared by an ion exchange method using water glass (sodium silicate) as a raw material, and alkoxide-process colloidal silica. The alkoxide-process colloidal silica is colloidal silica produced by the hydrolysis and condensation reaction of alkoxysilane. One type of colloidal silica can be used alone, or two or more types can be used in combination. The colloidal silica in the examples is prepared by the alkoxide method.

[0040] Since ordinary colloidal silica has a zeta potential value close to zero under acidic conditions, silica particles do not electrically repel each other under acidic conditions and tend to aggregate. In contrast, by surface-modifying colloidal silica so that the zeta potential of the colloidal silica has a relatively large positive or negative value even under acidic conditions, the colloidal silica particles strongly repel each other and disperse well even under acidic conditions, thereby improving the storage stability of the polishing composition.

[0041] As the surface-modified colloidal silica, colloidal silica with an organic acid immobilized on the surface can be used. The organic acid is immobilized on the surface of the colloidal silica by chemically bonding the functional group of the organic acid to the surface of the colloidal silica. The organic acid cannot be immobilized on the colloidal silica simply by allowing the colloidal silica and the organic acid to coexist. Specific examples of the organic acid include sulfonic acid, carboxylic acid, sulfinic acid, and phosphonic acid.

[0042] If sulfonic acid is immobilized on colloidal silica, for example, This can be done by the method described in "Acid-functionalized silica through quantitative oxidation of thiol groups", Chem. Commun. 246-247 (2003). Specifically, a silane coupling agent having a thiol group, such as 3-mercaptopropyltrimethoxysilane, is coupled to colloidal silica, and then the thiol group is oxidized with hydrogen peroxide to obtain colloidal silica having a sulfonic acid immobilized on its surface. The colloidal silica used in the following examples can be produced by the above method. Alternatively, if a carboxylic acid is to be immobilized on colloidal silica, for example, the method described in "Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel", Chemistry Letters, 3, 228-229 (2000). Specifically, a silane coupling agent containing a photoreactive 2-nitrobenzyl ester is coupled to colloidal silica, followed by light irradiation to obtain colloidal silica with a carboxylic acid immobilized on the surface.

[0043] As the colloidal silica having an organic acid fixed on the surface thereof, sulfonic acid-fixed colloidal silica is preferred.

[0044] The true specific gravity of the silica constituting the silica particles is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.7 or more. The polishing rate tends to increase as the true specific gravity of silica increases. From this perspective, silica particles having a true specific gravity of 2.0 or more (e.g., 2.1 or more) are particularly preferred. The upper limit of the true specific gravity of silica is not particularly limited, but is typically 2.3 or less, for example, 2.2 or less. The true specific gravity of silica can be measured by a liquid displacement method using ethanol as the displacement liquid. The true specific gravity is a value that can vary depending on the silica production method, etc. The true specific gravity of the silica used in the examples is 1.88.

[0045] The average primary particle size of the abrasive particles is not particularly limited and can be appropriately selected, for example, from a range of about 5 nm to 100 nm. From the viewpoint of improving the ability to eliminate bumps, the average primary particle size is preferably 5 nm or more, more preferably 7 nm or more, and even more preferably 10 nm or more. In some embodiments, it is 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, or 31 nm. Furthermore, from the viewpoint of preventing the occurrence of scratches, the average primary particle size is usually advantageously 200 nm or less, preferably 150 nm or less, more preferably 100 nm or less. In some embodiments, it is 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 45 nm or less, 40 nm or less, or 39 nm or less. The average primary particle size of the abrasive particles can be determined by first measuring the specific surface area of ​​the abrasive particles using the BET method, and then calculating the average primary particle size of the abrasive particles based on the measured specific surface area. Calculations are also made in this manner in the examples.

[0046] The average secondary particle size of the abrasive particles is preferably 25 nm or more, more preferably 30 nm or more, and even more preferably 35 nm or more, and in some embodiments, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, or 66 nm or more. As the average secondary particle size of the abrasive particles increases, the polishing rate for the polished object (e.g., a polished object containing a silicon or silicon germanium material) increases. circle.

[0047] The average secondary particle size of the abrasive particles is preferably 300 nm or less, more preferably 260 nm or less, and even more preferably 220 nm or less. In some embodiments, it is 200 nm or less, 180 nm or less, 160 nm or less, 140 nm or less, 120 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 75 nm or less, or 74 nm or less. As the average secondary particle size of the abrasive particles becomes smaller, it becomes easier to obtain a polished surface with fewer scratches when polishing an object to be polished using the polishing composition. The average secondary particle size of the abrasive particles can be measured by a suitable method, such as laser light scattering. Calculations are also made in the examples.

[0048] The shape (external shape) of the abrasive particles may be spherical or non-spherical. Specific examples of non-spherical particles include peanut-shaped particles, i.e., peanut shell-shaped particles, cocoon-shaped particles, projection-like shapes such as sugar candy shapes, and rugby ball-shaped particles. In the examples of the present application, cocoon-shaped particles are used. Using abrasive particles of such shapes has the effect of improving the polishing rate.

[0049] The average aspect ratio of the abrasive particles is not particularly limited. In principle, the average aspect ratio of the abrasive particles is 1.0 or more, and can be 1.05 or more, or 1.1 or more. Increasing the average aspect ratio generally tends to improve the ability to eliminate bumps. In addition, from the viewpoint of reducing scratches and improving polishing stability, the average aspect ratio of the abrasive particles is preferably 3.0 or less, more preferably 2.0 or less. In some embodiments, the average aspect ratio of the abrasive particles may be, for example, 1.5 or less, 1.4 or less, or 1.3 or less. The aspect ratio of the abrasive particles used in the examples is 1.24.

[0050] In some embodiments, the abrasive particles may have a volume fraction of particles with an aspect ratio of 1.2 or greater of 50%. The volume fraction may also be 60% or greater. When the volume fraction is 50% or greater, or even 60% or greater, the abrasive particles contain a relatively large number of particles with a size and aspect ratio that are particularly effective for eliminating bumps, thereby further improving the ability of the abrasive particles to eliminate bumps through mechanical action.

[0051] The content of abrasive particles is not particularly limited and can be appropriately set depending on the purpose. The content of abrasive particles relative to the total mass of the polishing composition may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more. Increasing the content of abrasive particles generally tends to improve the ability to eliminate bumps. In some embodiments, the content of abrasive particles may be 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, or 0.45% by mass or more. Furthermore, from the viewpoint of preventing scratches and saving the amount of abrasive particles used, in some embodiments, the content of abrasive particles may be, for example, 10% by mass or less, 5% by mass or less, 3% by mass or less, 2% by mass or less, 1.5% by mass or less, 1.0% by mass or less, 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, or 0.6% by mass or less. These contents can be preferably applied to the contents in the polishing liquid (working slurry) supplied to the object to be polished, for example.

[0052] [Glucose derivatives] The polishing composition of the present invention contains at least one glucose derivative, preferably at least two glucose derivatives. When the polishing composition of the present invention contains one glucose derivative, it is called the first glucose derivative. When two types of glucose derivatives are included, one is referred to as the first glucose derivative and the other is referred to as the second glucose derivative. When three or more types of glucose derivatives are included in the polishing composition of the present invention, they are referred to as the first glucose derivative, the second glucose derivative, the third glucose derivative, the fourth glucose derivative, etc. In some embodiments, the number of types of glucose derivatives is, for example, four or less, three or less, or two.

[0053] Surprisingly, when a glucose derivative is used in the polishing composition of the present invention, the polishing composition exhibits an inhibitory effect on the polishing of components other than silicon nitride (e.g., polysilicon), resulting in selective removal of silicon nitride. Furthermore, in some embodiments, the use of two or more glucose derivatives in the polishing composition not only inhibits the polishing of components other than silicon nitride, but also improves the removal rate of silicon nitride. It is speculated (without being limited by theory) that at least part of this is due to the glucose derivative's relatively high affinity for components other than silicon nitride in the workpiece, forming a thin film thereon during polishing and inhibiting the polishing of those components.

[0054] The glucose derivative used in the present invention may be any known glucose derivative without limitation, but does not include glucose itself. Examples include polysaccharides such as cellulose and starch, glucosides, and oxyalkylene derivatives of methyl glucoside disclosed in U.S. Patent Application Publication No. 2018 / 305580, the entire contents of which are incorporated herein by reference. In some embodiments, the glucose derivative used is a product obtained by chemical reaction (e.g., esterification or etherification) of hydroxy groups in glucose. The glucose derivative has an alkyl chain and / or an oxyalkylene side chain. The oxyalkylene may be derived from, for example, oxyethylene and / or oxypropylene, but is not limited thereto.

[0055] According to some embodiments, the glucose derivative having an alkyl chain is preferably a glucose derivative having an alkyl chain of 1 to 20 carbon atoms (2 to 19 carbon atoms, 3 to 18 carbon atoms, 4 to 17 carbon atoms, 5 to 16 carbon atoms, 6 to 15 carbon atoms, 7 to 14 carbon atoms, 8 to 13 carbon atoms, 9 to 12 carbon atoms, or 10 or 11 carbon atoms), or a mixture thereof. For example, lauryl glucoside, decyl glucoside, hexyl glucoside, coco glucoside, caprylyl / myristyl glucoside, glucoside, caprylyl / capryl glucoside, lauryl / myristyl glucoside, C9-11 alkyl glucoside mixture, C10-16 alkyl glucoside mixture, C8-16 alkyl glucoside mixture, etc.

[0056] According to some embodiments, the glucose derivative used is a glucose derivative having an alkyl chain represented by the following formula (1):

[0057] [ka]

[0058] In formula (1), R1 is a C1 to C20 alkyl group, preferably a C4 to C20 alkyl group, more preferably a C6 to C16 alkyl group, and in some embodiments, a C2 to C19 alkyl group, a C3 to C18 alkyl group, a C4 to C17 alkyl group, a C5 to C16 alkyl group, a C6 to C15 alkyl group, a C7 to C14 alkyl group, a C8 to C13 alkyl group, a C9 to C12 alkyl group, or a C10 to 11 alkyl group.

[0059] According to some embodiments, the glucose derivative having an alkyl chain represented by formula (1) is in the form of a mixture of multiple types of alkyl groups represented by R. The alkyl groups may be linear or branched.

[0060] According to some embodiments, the glucose derivative having an alkyl chain represented by formula (1) is in the form of a mixture of glucose derivatives in which R1 is a C3-18 alkyl group, R1 is a C4-C17 alkyl group, R1 is a C5-C16 alkyl group, R1 is a C6-C15 alkyl group, R1 is a C7-C15 alkyl group, R1 is a C8-C15 alkyl group, or R1 is a C9-C15 alkyl group. Here, for example, the form of a mixture of glucose derivatives in which R1 is a C9-C15 alkyl group means that the glucose derivative having an alkyl chain represented by formula (1) is in the form of a mixture of glucose derivatives in which R1 is a C9 alkyl group (R2-R5, n is optional) in formula (1), glucose derivatives in which R1 is a C10 alkyl group (R2-R5, n is optional) in formula (1), and glucose derivatives in which R1 is a C11 alkyl group (R2-R5, n is optional) in formula (1). and at least two endpoint compounds selected from the group consisting of glucose derivatives of formula (1) in which R1 is a C12 alkyl group (R2 to R5, n is any), glucose derivatives of formula (1) in which R1 is a C13 alkyl group (R2 to R5, n is any), glucose derivatives of formula (1) in which R1 is a C14 alkyl group (R2 to R5, n is any), and glucose derivatives of formula (1) in which R1 is a C15 alkyl group (R2 to R5, n is any). In other words, the mixture of glucose derivatives in which R1 is a C9 to C15 alkyl group contains, as endpoint compounds, glucose derivatives of formula (1) in which R1 is a C9 alkyl group (R2 to R5, n is any), and glucose derivatives of formula (1) in which R1 is a C15 alkyl group (R2 to R5, n is any). The same is considered throughout this specification.

[0061] According to some embodiments, the glucose derivative having an alkyl chain represented by formula (1) is in the form of a mixture in which R1 is a C3-13 alkyl group, R1 is a C4-C12 alkyl group, R1 is a C5-C11 alkyl group, R1 is a C6-C11 alkyl group, R1 is a C7-C11 alkyl group, or a C8-C11 alkyl group, or a C9-C11 alkyl group. In some embodiments, the glucose derivative in the form of a mixture is substantially free of glucose derivatives in which R1 is an alkyl group of C12 or more, C13 or more, C14 or more, or C15 or more. Here, "substantially free" means that the excluded component is not included, except in cases where it is inevitably included, for example, due to its origin in raw materials. The term "substantially free" used herein is interpreted accordingly.

[0062] According to some embodiments, the glucose derivative having an alkyl chain represented by formula (1) is in the form of a mixture in which R1 is a C8-18 alkyl group, R1 is a C9-C17 alkyl group, R1 is a C10-C16 alkyl group, R1 is a C11-C15 alkyl group, R1 is a C11-C14 alkyl group, or R1 is a C12-C14 alkyl group. In some embodiments, the glucose derivative in the form of a mixture is substantially free of glucose derivatives in which R1 is an alkyl group of C12 or less, C11 or less, C10 or less, C9 or less, or C8 or less.

[0063] In formula (1), R2, R3, R4, and R5 are each independently a hydrogen atom or a C1-C4 alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom. According to some embodiments, in formula (1), R2, R3, R4, and R5 are each independently a C1-C3 alkyl group or a C1 or C2 alkyl group.

[0064] In the formula (1), n ​​is, for example, 1 to 5.

[0065] According to some embodiments, the glucose derivative having an oxyalkylene side chain is preferably a glucose derivative having an oxyethylene, an oxypropylene, or both side chains. For example, a glucose derivative having an oxyethylene side chain, a glucose derivative having an oxypropylene side chain, or a glucose derivative having an oxyethylene / oxypropylene side chain may be included. In the glucose derivative having an oxyethylene / oxypropylene side chain, the oxyethylene and oxypropylene may be located on the same side chain or on different side chains.Examples of glucose derivatives having an oxyalkylene side chain include methyl glucose caprylate / caprate, methyl glucose dioleate, methyl glucose isostearate, methyl glucose laurate, methyl glucose sesquicaprylate / sesquicaprate, methyl glucose sesquicocoate, methyl glucose sesquiisostearate, methyl glucose sesquilaurate, methyl glucose sesquioleate, methyl glucose sesquistearate, methyl glucose polyether-10, methyl glucose polyether-20, PPG-10 methyl glucose polyether (PPG-10 methyl glucose polyether). ether, PPG-20 methyl glucose ether, PPG-25 methyl glucose ether, PPG-20 methyl glucose ether acetate, PPG-20 methyl glucose ether distearate, PEG-120 methyl glucose dioleate. glucose dioleate, PEG-20 methyl glucose distearate, PEG-80 methyl glucose laurate, PEG-20 methyl glucose sesquicaprylate / sesquicaprate, PEG-20 methyl glucose sesquilaurate Examples of suitable PEG-120 methyl glucose trioleate include PEG-120 methyl glucose sesquilaurate, PEG-20 methyl glucose sesquistearate, PEG-120 methyl glucose triisostearate, PEG-120 methyl glucose trioleate, PEG-20 methyl glucose trioleate, and PEG-120 ethyl glucose trioleate propanediol.

[0066] According to some embodiments, the glucose derivative used has a structure represented by formula (2):

[0067] [ka]

[0068] In formula (2), each AO is independently an oxyalkylene group, preferably an oxyethylene group and / or an oxypropylene group, and may be an oxytrimethylene group.

[0069] Each R is independently a hydrogen atom or a C1-C18 alkyl group. According to some embodiments, each R is a C1-C15 alkyl group, a C1-C12 alkyl group, a C1-C10 alkyl group, a C1-C8 alkyl group, a C1-C6 alkyl group, a C1-C4 alkyl group, or a C1, C2, or C3 alkyl group. At least a portion of R may be at least one of a C2-21 alkenyl group, a C3-21 alkenylcarbonyl group, and a C2-C21 alkylcarbonyl group.

[0070] a, b, c, and d each independently represent an integer from 1 to 150, an integer from 1 to 140, an integer from 1 to 130, an integer from 1 to 120, or an integer from 1 to 100, preferably an integer from 1 to 50, and more preferably an integer from 1 to 30. According to some embodiments, a, b, c, and d each independently represent an integer of 2 or greater, an integer of 3 or greater, an integer of 4 or greater, an integer of 5 or greater, an integer of 6 or greater, an integer of 7 or greater, an integer of 8 or greater, an integer of 9 or greater, an integer of 10 or greater, an integer of 12 or greater, an integer of 14 or greater, an integer of 16 or greater, or an integer of 18 or greater. According to some embodiments, a, b, c, and d each independently represent an integer of 30 or less, an integer of 28 or less, an integer of 26 or less, an integer of 24 or less, an integer of 22 or less, an integer of 20 or less, an integer of 18 or less, an integer of 16 or less, an integer of 14 or less, or an integer of 12 or less. Some of a, b, c, and d may be 0.

[0071] According to some embodiments, a+b+c+d is an integer greater than or equal to 2, greater than or equal to 3, greater than or equal to 4, greater than or equal to 5, greater than or equal to 6, greater than or equal to 7, greater than or equal to 8, greater than or equal to 9, greater than or equal to 10, greater than or equal to 12, greater than or equal to 14, greater than or equal to 16, or greater than or equal to 18. According to some embodiments, a+b+c+d is an integer less than or equal to 30, less than or equal to 28, less than or equal to 26, less than or equal to 24, less than or equal to 22, less than or equal to 20, less than or equal to 18, less than or equal to 16, less than or equal to 14, or less than or equal to 12. According to some embodiments, a+b+c+d is an integer between 6 and 14. According to some embodiments, a+b+c+d is an integer between 16 and 24.

[0072] As described above, at least one glucose derivative may be used, or at least two glucose derivatives may be used. From the viewpoint of more suitably exhibiting the effect of selectively removing silicon nitride, it is preferable to use at least two glucose derivatives in combination, and it is more preferable to use at least a glucose derivative having an alkyl chain and a glucose derivative having an oxyalkylene side chain in combination. It is also more preferable to use two or more glucose derivatives having alkyl chains in combination.

[0073] According to some embodiments, the glucose derivative comprises at least a glucose derivative having an alkyl chain.

[0074] According to some embodiments, the glucose derivative comprises at least a glucose derivative having an oxyalkylene side chain.

[0075] According to some embodiments, the glucose derivative is in the form of a mixture that is substantially free of glucose derivatives of formula (1) in which R1 has an alkyl group of C11 or less, C10 or less, C9 or less, or C8 or less. According to some embodiments, the mass proportion of the glucose derivatives in this mixture is 40 mass% or more, or 50 mass% or more, based on the total amount of the glucose derivatives.

[0076] According to some embodiments, the glucose derivatives are in the form of a mixture substantially free of glucose derivatives in which R1 in formula (1) has an alkyl group of C11 or more, C12 or more, C13 or more, C14 or more, or C15 or more, and glucose derivatives in the form of a mixture in which R1 in formula (1) has an alkyl group of C8 to C14. According to some embodiments, the total mass proportion of these glucose derivatives is 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, 95 mass% or more, or 100 mass% based on the total amount of glucose derivatives.

[0077] According to some embodiments, the glucose derivative comprises a glucose derivative in which A0 in formula (2) is each independently an oxyethylene group and a+b+c+d is an integer of 6 to 14, a glucose derivative in formula (1) in which R1 is a mixture of C8 to C14, and a chelating agent, wherein the chelating agent is a compound represented by the following formula (3) or a salt thereof, in which R1 to R5 in formula (3) are phosphonic acid groups or alkyl groups substituted with phosphonic acid groups, or a compound represented by the following formula (4) or a salt thereof. In these embodiments, the total mass proportion of these glucose derivatives relative to the total amount of the glucose derivatives is 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass.

[0078] According to some embodiments, the glucose derivatives include a glucose derivative in which a+b+c+d in formula (2) is an integer of 16 to 24, and a glucose derivative in the form of a mixture in which R1 in formula (1) is C8 to C14. According to some embodiments, the total mass proportion of these glucose derivatives is 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, 95 mass% or more, or 100 mass% with respect to the total amount of the glucose derivatives.

[0079] According to some embodiments, the glucose derivatives substantially comprise glucose derivatives in which a+b+c+d in formula (2) is an integer of 16 to 24, and glucose derivatives in formula (1) in which R1 has an alkyl group of C11 or less, C10 or less, C9 or less, or C8 or less. and glucose derivatives in the form of a mixture thereof. According to some embodiments, the total mass proportion of these glucose derivatives is 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass based on the total amount of glucose derivatives.

[0080] According to some embodiments, when the glucose derivatives include glucose derivatives having alkyl chains (where the glucose derivatives do not have oxyalkylene side chains), the amount of the glucose derivatives having alkyl chains is 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight of the total amount of the glucose derivatives.

[0081] According to some embodiments, when the glucose derivative comprises a glucose derivative having an oxyalkylene side chain (wherein the glucose derivative does not have an alkyl chain), the amount of the glucose derivative having an oxyalkylene side chain is 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight of the total amount of the glucose derivative.

[0082] According to some embodiments, when the glucose derivatives include a glucose derivative having an alkyl chain and a glucose derivative having an oxyalkylene side chain, the amount of the glucose derivative having an alkyl chain and the glucose derivative having an oxyalkylene side chain is 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight of the total amount of the glucose derivatives.

[0083] The upper limit of the total content of glucose derivatives relative to the total mass of the polishing composition is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 2% by mass or less, and most preferably 1% by mass or less. According to some embodiments, the upper limit of the total content of glucose derivatives relative to the total mass of the polishing composition is 0.8% by mass or less, 0.6% by mass or less, 0.4% by mass or less, 0.2% by mass or less, 0.1% by mass or less, 0.09% by mass or less, or 0.06% by mass or less.

[0084] Furthermore, the lower limit of the total content of glucose derivatives relative to the total mass of the polishing composition is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, and most preferably 0.02% by mass or more. According to some embodiments, the lower limit of the total content of glucose derivatives relative to the total mass of the polishing composition is 0.03% by mass or more, 0.04% by mass or more, 0.05% by mass or more, 0.06% by mass or more, or 0.07% by mass or more.

[0085] [Chelating agent] According to some embodiments, the polishing composition further comprises a chelating agent.

[0086] Typically, chelating agents are added to polishing compositions to form complex ions with impurities generated by chemical mechanical polishing, thereby removing the impurities and preventing them from remaining on the surface of the workpiece after polishing and causing contamination. However, research has shown that the use of a specific chelating agent in the polishing composition of the present invention can further improve the polishing / removal rate of silicon nitride, and therefore can be used as a silicon nitride removal accelerator. (Without being limited by theory, it is speculated that at least part of this is due to the fact that the chelating agent contained in the polishing composition of the present invention generates a weak adsorption force with silicon nitride during polishing, forming a hydrophilic layer on the surface of the silicon nitride, and the affinity between this hydrophilic layer and colloidal silica (as shown in Figure 1) increases the probability of contact between silica (especially colloidal silica) abrasive particles and silicon nitride. Therefore, it is useful for improving the polishing rate of silicon nitride. It is thought that this is the case.

[0087] Examples of chelating agents that can be used in the present invention include aminocarboxylic acid chelating agents and phosphonate chelating agents.

[0088] The chelating agent that can be used in the present invention is, for example, a compound represented by the following formula (3) or a salt thereof:

[0089] [ka]

[0090] In the formula (3), Y 1 and Y 2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, n is an integer of 0 to 4, and R 1 ~R 5 are each independently a phosphonic acid group, a carboxyl group, an alkyl group substituted with a phosphonic acid group, or an alkyl group substituted with a carboxyl group.

[0091] In some embodiments, in the above formula (3), Y 1 and Y 2 The linear or branched alkylene group having 1 to 5 carbon atoms as the alkylene group is not particularly limited and includes linear or branched alkylene groups such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a propylene group, etc. Among these, a linear or branched alkylene group having 1 to 4 carbon atoms is preferred, a linear or branched alkylene group having 1 to 3 carbon atoms is more preferred, an alkylene group having 1 or 2 carbon atoms, i.e., a methylene group or an ethylene group, is even more preferred, and an ethylene group is particularly preferred.

[0092] In some embodiments, n in the above formula (3) is (-Y 1 -N(R 5)-) and is an integer of 0 to 4. According to some embodiments, n is an integer of 0 to 3, an integer of 0 to 2, or 0 or 1. When n is 2 or more, n (-Y 1 -N(R 5 )-) may be the same or different.

[0093] In some embodiments, R 1 ~R 4 two or more of R are phosphonic acid groups, carboxyl groups, alkyl groups substituted with phosphonic acid groups, or alkyl groups substituted with carboxyl groups; 1 ~R 4 three or more of which are phosphonic acid groups, carboxyl groups, alkyl groups substituted with phosphonic acid groups, or alkyl groups substituted with carboxyl groups, or R 1 ~R 4 In some embodiments, four of R are phosphonic acid groups or carboxyl groups, or alkyl groups substituted with phosphonic acid groups or alkyl groups substituted with carboxyl groups. 5 is a phosphonic acid group, a carboxyl group, an alkyl group substituted with a phosphonic acid group, or an alkyl group substituted with a carboxyl group. 1 ~R 5 (or R 1 ~R 4 ) may be the same or different. The alkyl groups in the alkyl group substituted with a phosphonic acid group or the alkyl group substituted with a carboxyl group each independently have 1 to 4, 1 to 3, or 1 or 2 carbon atoms.

[0094] The chelating agent that can be used in the present invention is, for example, a compound represented by the following formula (4) or a salt thereof:

[0095] [ka]

[0096] In the formula (4), R 6 ~R 9are each independently a hydrogen atom, a phosphonic acid group, an alkyl group having 1 to 4 carbon atoms substituted with a phosphonic acid group, a hydroxy group, or an alkyl group having 1 to 4 carbon atoms, and in this case, R 6 ~R 9 At least one of the groups is a phosphonic acid group or an alkyl group having 1 to 4 carbon atoms and substituted with a phosphonic acid group. Examples of the alkyl group having 1 to 4 carbon atoms (including those substituted with a phosphonic acid group) include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0097] In some embodiments, R 6 ~R 9 At least two of R are phosphonic acid groups or alkyl groups having 1 to 4 carbon atoms substituted with phosphonic acid groups. 6 ~R 9 and R 6 ~R 9 are phosphonic acid groups. In some embodiments, R 6 ~R 9 is independently a hydroxy group or an alkyl group having 1 to 4 carbon atoms. 6 ~R 9 One of the groups is a hydroxy group, and R 6 ~R 9 One of them is an alkyl group having 1 to 4 carbon atoms (1 to 3 carbon atoms, or 1 or 2 carbon atoms).

[0098] The chelating agent that can be used in the present invention is, for example, a compound represented by the following formula (5) or a salt thereof:

[0099] [ka]

[0100] In the formula (5), R 10 ~R12 are each independently a hydrogen atom, a hydroxy group, a phosphonic acid group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms substituted with a phosphonic acid group, an alkyl group having 1 to 4 carbon atoms substituted with a hydroxy group, an alkyl group having 1 to 4 carbon atoms substituted with a carboxyl group, or an alkyl group having 1 to 4 carbon atoms, and in this case, R 6 ~R 9 At least one of the groups is a phosphonic acid group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms and substituted with a phosphonic acid group, or an alkyl group having 1 to 4 carbon atoms and substituted with a carboxyl group. Examples of the alkyl group having 1 to 4 carbon atoms (including those substituted with a phosphonic acid group, a carboxyl group, or a hydroxy group) include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0101] In some embodiments, R 10 ~R 12 At least two of R are a phosphonic acid group, a carboxyl group, a C alkyl group substituted with a phosphonic acid group, or a C alkyl group substituted with a carboxyl group. 6 ~R 9 One of them is an alkyl group having 1 to 4 carbon atoms substituted with a hydroxy group.

[0102] Examples of aminocarboxylic acid chelating agents include hydroxyethyliminodiacetic acid, ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetate, hydroxyethylethylenediaminetriacetic acid, sodium hydroxyethylethylenediaminetriacetate, diethylenetriaminepentaacetic acid (DTPA), sodium diethylenetriaminepentaacetate, triethylenetetraminehexaacetic acid, and sodium triethylenetetraminehexaacetate.

[0103] Phosphonate chelating agents include 2-aminoethylphosphonic acid, 1-hydroxyethylphosphonic acid, methylidene-1,1-diphosphonic acid, aminotris(methylenephosphonic acid), ethylenediaminetetrakis(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid, and α-methylphosphonosuccinic acid. Of these chelating agents, preferred are hydroxyethyliminodiacetic acid, diethylenetriaminepenta(methylenephosphonic acid), ethylenediaminetetrakis(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, aminotris(methylenephosphonic acid), and ethylenediaminetetraacetic acid.

[0104] The content of the chelating agent relative to the total mass of the polishing composition is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, and even more preferably 0.001% by mass or more. In some embodiments, the content of the chelating agent relative to the total mass of the polishing composition is 0.003% by mass or more, 0.005% by mass or more, 0.007% by mass or more, 0.009% by mass or more, 0.011% by mass or more, 0.013% by mass or more, 0.015% by mass or more, 0.017% by mass or more, 0.019% by mass or more, 0.021% by mass or more, or 0.023% by mass or more. Increasing the content of the chelating agent can increase the removal rate of silicon nitride. Furthermore, the content of the chelating agent in the polishing composition is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. In some embodiments, the content of the chelating agent is 0.04 mass % or less, or 0.03 mass % or less, based on the total mass of the polishing composition. By reducing the content of the chelating agent, the storage stability of the polishing composition can be better maintained.

[0105] In some embodiments, when the chelating agent includes an aminocarboxylic acid chelating agent and / or a phosphonate chelating agent, the proportion of the aminocarboxylic acid chelating agent and / or the phosphonate chelating agent in the chelating agent is 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 98% by weight or more.

[0106] [pH adjuster (pH adjuster)] The polishing composition of the present invention contains a pH adjuster. The pH of the polishing composition can be adjusted to a desired value by the pH adjuster. Known acidic or basic compounds can be used as the pH adjuster.

[0107] The acidic compound may be an inorganic acid or an organic acid. Examples of inorganic acids include hydrochloric acid (HCl), sulfuric acid (HSO), nitric acid (HNO), hydrofluoric acid (HF), boric acid (HBO), carbonic acid (HCO), hypophosphorous acid (HPO), phosphorous acid (HPO), and phosphoric acid (HPO). Among these inorganic acids, hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid are preferred.

[0108] Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, hydroxyacetic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid. ipic acid, pimelic acid, maleic acid, phthalic acid, malic acid Examples of suitable sulfuric acids include 2-furancarboxylic acid, tartaric acid, citric acid, lactic acid, glyoxylic acid, 2-furancarboxylic acid, 2,5-furandicarboxylic acid, 3-furancarboxylic acid, 2-tetrahydrofurancarboxylic acid, methoxyacetic acid, methoxyphenylacetic acid, and phenoxyacetic acid. Organic sulfuric acids such as methanesulfonic acid, ethanesulfonic acid, and 2-hydroxyethanesulfonic acid may also be used. Of these organic acids, preferred are monocarboxylic acids such as acetic acid; dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, and tartaric acid; and tricarboxylic acids such as citric acid.

[0109] Examples of basic compounds include hydroxides or salts of alkali metals, hydroxides or salts of Group 2 elements, quaternary ammonium hydroxide or its salts, ammonia, amines, etc. Examples of alkali metals include potassium, sodium, etc.

[0110] The pH of the polishing composition of the present invention is less than 3. If the pH is too high (for example, if the pH is 3 or higher), the removal rate of portions of the same object with a relatively low surface height may increase, and the difference (ratio) in the removal rate of portions of the same object with different surface heights may decrease. As a result, this is disadvantageous for reducing or eliminating steps. The upper limit of the pH is preferably 2.8 or less, more preferably 2.6 or less, and even more preferably 2.4 or less. The upper limit of the pH may be 2.7 or less, 2.5 or less, 2.3 or less, or even 2.2 or less. The lower limit of the pH of the polishing composition of the present invention is not particularly limited. However, considering the safety of the manufacturing process and the burden of wastewater treatment, it is preferably 0.8 or more, more preferably 1 or more, and even more preferably 1.5 or more. The lower limit of the pH may be 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, or even more than 2.0. The pH of the polishing composition of the present invention is preferably in the range of 0.8 or more and less than 3. The pH in the present invention refers to the pH at 25° C. The pH at 25° C. can be measured with a pH meter, and is the value after immersing an electrode in the polishing composition for 1 minute.

[0111] The content of the pH adjuster (pH regulator) in the polishing composition of the present invention is not particularly limited, and may be such that the desired pH is obtained.

[0112] [Other ingredients] The polishing composition of the present invention may contain other components (components different from the components specifically mentioned above) as long as the effects of the present invention are not impaired. Examples of other components include surfactants, organic acids, organic acid salts, inorganic acids, inorganic acid salts, preservatives, fungicides, and other well-known additives used in polishing compositions.

[0113] Examples of surfactants include polyethylene glycol (polyoxyethylene), polypropylene glycol (poly-1,2-epoxypropane), random copolymers of oxyethylene and 1,2-epoxypropane, block copolymers of oxyethylene and 1,2-epoxypropane, polyoxyethylene alkyl ethers, and polyoxyethylene sorbitan fatty acid esters, among which polyethylene glycol and polypropylene glycol are particularly preferred. is particularly preferred. One or more of these surfactants may be used, or two or more of the same surfactants with different molecular weights may be mixed and used. The average molecular weight of the surfactant is preferably 300 to 50,000.

[0114] According to some embodiments, the other components comprise 10% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.001% by weight or less, or 0.0005% by weight or less, based on the total weight of the components excluding the dispersion medium.

[0115] [Dispersion medium] The polishing composition of the present invention contains a dispersion medium (which may also be referred to as a "solvent"). The dispersion medium can be used to disperse or dissolve each component in the polishing composition. In the present invention, the polishing composition may contain water as a dispersion medium. From the viewpoint of suppressing the effect on other components, water that contains as few impurities as possible is preferred. More specifically, pure water or ultrapure water, which has been subjected to removal of impurity ions with an ion exchange resin and then passed through a filter to remove foreign matter, or distilled water is preferred.

[0116] In some embodiments, the water content in the dispersion medium is 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 96% by weight or more, 97% by weight or more, 98% by weight or more, 99% by weight or more, or 100% by weight.

[0117] In some embodiments, when the polishing composition contains abrasive particles, a pH adjuster, a chelating agent, at least one glucose derivative, and a dispersion medium, the total proportion of the abrasive particles, the pH adjuster, the chelating agent, and the at least one glucose derivative, among the components excluding the dispersion medium, is 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 96% by mass or more, 97% by mass or more, 98% by mass or more, 99% by mass or more, or 99.5% by mass or more.

[0118] [Application] The polishing composition of the present invention is used for treating a specific object. There are no particular limitations on the treatment method, and for example, planarization, selective removal, or cleaning can be performed. The treatment method is preferably chemical mechanical polishing. The polishing process may be a single-step polishing process or a multi-step polishing process. Examples of multi-step polishing processes include a process in which a preliminary polishing step (rough polishing step) is followed by a finish polishing step, or a process in which a primary polishing step is followed by one or more secondary polishing steps, and then a finish polishing step is performed.

[0119] [Materials to be processed] There is no particular limitation on the object to be treated using the polishing composition of the present invention, and examples thereof include semiconductor materials such as wafers and substrates, and optical elements such as lenses and glass substrates, and preferably materials or elements from which silicon nitride needs to be removed or from which silicon nitride needs to be selectively removed. Preferably, the material contains silicon nitride or polysilicon and silicon nitride. More preferred are those comprising polysilicon and silicon nitride.

[0120] [Surface treatment equipment (polishing equipment)] There are no particular limitations on the surface treatment device using the polishing composition of the present invention, and examples thereof include devices that perform planarization treatment, selective removal treatment, and cleaning treatment on an object to be treated.

[0121] The surface treatment equipment (polishing equipment) consists of a holder for holding a substrate or the like having an object to be polished, A general polishing device can be used that is equipped with a motor or the like that can change the rotation speed and has a polishing platen to which a polishing pad (polishing cloth) can be attached.

[0122] The polishing pad may be made of any material, including, without limitation, a general nonwoven fabric, polyurethane, porous fluororesin, etc. The polishing pad is preferably provided with grooves for accumulating the polishing composition.

[0123] The polishing conditions are not particularly limited, and for example, the rotation speed of the polishing platen is preferably 10 to 500 rpm, the rotation speed of the carrier is preferably 10 to 500 rpm, and the pressure (polishing pressure) applied to the substrate having the object to be polished is preferably 0.1 to 10 psi. The method of supplying the polishing composition to the polishing pad is also not particularly limited, and for example, a method of continuously supplying it using a pump or the like is used. There is no limit to the amount of supply, but it is preferable that the surface of the polishing pad is always covered with the polishing composition of the present invention.

[0124] [Method for selectively removing silicon nitride] The present invention also provides a method for selectively removing silicon nitride using the above polishing composition.

[0125] The method of the present invention for selectively removing silicon nitride is not particularly limited as long as a polishing composition such as that of the present invention is used, and may be carried out in conjunction with known manufacturing or processing methods for semiconductor materials or optical elements, etc.

[0126] In some embodiments, under the conditions for measuring the polishing rate described in the examples, the silicon nitride / polysilicon selectivity is 10 or more, greater than 14.8, 15 or more, 20 or more, greater than 23.5, 25 or more, 30 or more, greater than 34.9, 35 or more, 40 or more, 45 or more, 46.2 or more, 50 or more, 55 or more, 56.3 or more, or 60 or more. [Example]

[0127] The present invention will be further explained below with reference to examples and comparative examples, but the scope of the present invention is not limited to the examples described below. Furthermore, unless otherwise specified in the examples described below, the polishing operation conditions are room temperature (20 to 25°C) and a relative humidity of 40 to 50% RH.

[0128] [Preparation of Polishing Composition] Polishing compositions were prepared by mixing abrasive particles, a chelating agent, a first glucose derivative, and a second glucose derivative in a dispersion medium (ultrapure water) while adjusting the pH with a pH adjuster (mixing temperature: about 25°C, mixing time: about 10 minutes) according to the composition shown in Table 1 below. The pH of the polishing composition was confirmed using a pH meter (manufactured by Horiba, Ltd., model number: LAQUA) (the temperature of the polishing composition during pH measurement was 25°C). In Table 1, "-" indicates that the component was not added. Each component and number in Table 1 are explained below. As shown in Table 1, some examples and comparative examples do not contain at least some of the chelating agent, the first glucose derivative, and the second glucose derivative.

[0129] SiO2: Colloidal silica with sulfonic acid fixed on the surface [average primary particle size: 35 nm, average secondary particle size: 70 nm], DTPMP: diethylenetriaminepenta(methylenephosphonic acid), ATMP: aminotris(methylenephosphonic acid); HEDP: 1-hydroxyethylidene-1,1-diphosphonic acid; HIDA: hydroxyethyliminodiacetic acid; EDTA: ethylenediaminetetraacetic acid; G1-1: Caprylyl / Myristyl Glucoside In the following formula, n = 7 to 13 in alkyl chain (R) (DP: 1-5), G1-2: Caprylyl / capryl glucoside In the following formula, n=7-9 in alkyl chain (R) (DP: 1-5), G1-3: Lauryl / myristyl glucoside In the following formula, n = 11 to 13 in alkyl chain (R) (DP: 1-5),

[0130] [ka]

[0131] G1-4: glucose,

[0132] G2-1: Methyl glucose polyether-10: [ka] (a+b+c+d=10)

[0133] G2-2: Methyl glucose polyether-20: [ka] (a+b+c+d=20)

[0134] G2-3: PPG-10 methyl glucose polyether: [ka] (a+b+c+d=10)

[0135] RR[Å / min]: Polishing rate.

[0136] [Measurement of polishing speed] Each wafer was polished under the following conditions using the polishing composition obtained in the above-mentioned preparation of polishing composition, and the removal rate was measured.

[0137] Polishing equipment: Ebara Corporation FREX 300E Polishing pad: Rohm and Haas IC1010 Dresser: 3M Corp. A188 Silicon nitride polishing time: 60 seconds Polysilicon polishing time: 120 seconds Polishing pressure: 1 psi (1 psi = 6894.76 Pa) Platen rotation speed: 90 rpm Head (carrier) rotation speed: 90 rpm Polishing composition supply rate: 300 ml / min.

[0138] [Table 1]

[0139] As shown in Table 1, when polishing is performed using the polishing compositions of Examples 1 and 2 containing one glucose derivative, the polishing rate for polysilicon is reduced and the polishing rate for silicon nitride is increased, compared to Comparative Examples 1 and 2. In Examples 3 to 15, the polishing rate for polysilicon containing two glucose derivatives is reduced. By using such a compound, the protective effect on the polysilicon substrate surface can be further enhanced. As can be seen from the experimental results, among Examples 1 to 11 using the same chelating agent, the polishing rates for polysilicon in Examples 3 to 11 are lower than those in Examples 1 and 2, but the polishing rates for silicon nitride are equal to or higher than those in Examples 1 and 2. Furthermore, the polishing compositions of Examples 1 to 13 using a phosphonate-based chelating agent and Examples 14 and 15 using an aminocarboxylic acid-based chelating agent all have the effect of efficiently and selectively removing silicon nitride from polysilicon.

[0140] As can be seen from Comparative Examples 2 and 3, the addition of a phosphonate-based chelating agent helps improve the removal rate of silicon nitride. However, although silicon nitride can be polished at a high removal rate, the removal rate of polysilicon also increases, which may affect the effect of selectively removing silicon nitride relative to polysilicon. Furthermore, as can be seen from Comparative Examples 2 and 3, although glucose was separately added to the polishing composition of Comparative Example 3, the removal rate of silicon nitride and the removal rate of polysilicon were roughly the same as those of Comparative Example 2, indicating that glucose does not exert any significant effect on the polishing composition. Furthermore, compared to Examples 1 to 15, which used glucose derivatives, Comparative Example 3, which used glucose, showed poor effect of selectively removing silicon nitride.

[0141] This application is based on Japanese Patent Application No. 2021-57279, filed on March 30, 2021, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. abrasive particles and at least one glucose derivative, and a pH of less than 3; The at least one glucose derivative is at least one of a glucoside having an alkyl chain having 3 to 20 carbon atoms or a mixture thereof, and a glucose derivative represented by the following formula (2): 【Chemistry 2】 In formula (2), Each AO is independently an oxyalkylene group; Each R is independently a hydrogen atom or a C1 to C18 alkyl group; A polishing composition wherein a+b+c+d is an integer of 4 or more and 30 or less.

2. The polishing composition according to claim 1 , comprising at least two glucose derivatives.

3. The polishing composition according to claim 1 or 2, having a pH of greater than 1.

8.

4. 4. The polishing composition according to claim 1, wherein the abrasive particles have an average secondary particle size of more than 45 nm.

5. 5. The polishing composition according to claim 1, wherein the abrasive particles are silica particles.

6. 6. The polishing composition according to claim 5, wherein the silica particles are sulfonic acid-fixed colloidal silica.

7. The polishing composition according to any one of claims 1 to 6, further comprising a chelating agent.

8. The polishing composition according to claim 7 , wherein the chelating agent comprises a phosphonate-based chelating agent.

9. The polishing composition according to any one of claims 1 to 8, further comprising a pH adjuster.

10. 10. The polishing composition according to claim 1, which is used for polishing silicon nitride and polysilicon, and has a selectivity, which is the polishing rate (Å / m) for silicon nitride to the polishing rate (Å / m) for polysilicon, of 10 or more.

11. The glucoside or mixture thereof may be selected from the group consisting of lauryl glucoside, decyl glucoside, hexyl glucoside, coco glucoside, caprylyl / myristyl glucoside, caprylyl / capryl glucoside, lauryl / myristyl glucoside, C9-11 alkyl glucoside, 11. The polishing composition according to claim 1, wherein the polishing composition is a mixture of C10-16 alkyl glucosides, a mixture of C10-16 alkyl glucosides, or a mixture of C8-16 alkyl glucosides.

12. A method for selectively removing silicon nitride, comprising using the polishing composition according to any one of claims 1 to 11.

Images