Raw material for obtaining abrasive grains, method for selecting raw material for obtaining abrasive grains, method for producing abrasive grains, method for producing polishing liquid, polishing method, method for producing component, and method for producing semiconductor component

Abstract

A method for selecting a raw material for obtaining abrasive grains, the raw material including cerium, the raw material being selected on the basis of a peak top temperature in a differential curve of a thermogravimetric curve obtained by thermogravimetric analysis of the raw material. A starting material for obtaining abrasive grains, the starting material containing cerium, and having a peak top temperature in a differential curve of a thermogravimetric curve obtained by thermogravimetric analysis of the starting material of 300 DEG C or more. Also disclosed is a method for producing abrasive grains by pulverizing the raw material. Also provided is a method for producing a polishing liquid in which the abrasive grains obtained by the method for producing the abrasive grains and water are mixed. Also provided is a polishing method for polishing a member to be polished using the polishing liquid obtained by the method for producing the polishing liquid.

Description

Technical Field

[0001] The present invention relates to a raw material for obtaining abrasive grains and a method for selecting the same, a method for manufacturing abrasive grains, a method for manufacturing a polishing liquid, a polishing method, a method for manufacturing parts, a method for manufacturing semiconductor parts, and the like. Background Art

[0002] In recent years, the importance of processing technologies for high density and miniaturization has been increasing in the manufacturing process of electronic devices. CMP (chemical mechanical polishing) technology, which is one of the processing technologies, has become a technology required for the formation of shallow trench isolation (STI), planarization of pre-metal insulating materials or interlayer insulating materials, and formation of plugs or embedded metal wiring in the manufacturing process of electronic devices. As a polishing liquid used for CMP, a polishing liquid containing abrasive grains containing cerium is known (for example, refer to the following patent documents 1 and 2).

[0003] Previous technical literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 10-106994

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 08-022970 Summary of the invention

[0007] Technical issues to be solved by the invention

[0008] The abrasive grains used in the polishing liquid can be obtained by subjecting the raw material for obtaining the abrasive grains to a treatment such as pulverization. For the polishing liquid containing such abrasive grains, it is required to adjust the polishing speed of the material to be polished according to the application, and a new method for adjusting the polishing speed of the material to be polished is required. In addition, for the polishing liquid containing abrasive grains, it is sometimes required to increase the polishing speed of silicon oxide in the pattern wafer, for example, it is sometimes required to increase the polishing speed of silicon oxide in the pattern area having a linear silicon nitride pattern (Line: line) / silicon oxide pattern (Space: space) with a line width of 50μm / 50μm (a pattern area where a linear silicon nitride pattern with a line width of 50μm and a linear silicon oxide pattern with a line width of 50μm are alternately arranged).

[0009] An object of one aspect of the present invention is to provide a method for selecting a raw material, which is a method for selecting a raw material for obtaining abrasive grains, and the method is capable of adjusting the polishing speed of a material to be polished when the material to be polished is polished using the abrasive grains. An object of another aspect of the present invention is to provide a raw material, which is capable of obtaining abrasive grains having a high polishing speed of silicon oxide in a pattern area having a linear silicon nitride pattern / silicon oxide pattern with a line width of 50 μm / 50 μm. An object of another aspect of the present invention is to provide a method for manufacturing abrasive grains using the raw material. An object of another aspect of the present invention is to provide a method for manufacturing a polishing liquid using abrasive grains obtained by the method for manufacturing the abrasive grains. An object of another aspect of the present invention is to provide a polishing method using a polishing liquid obtained by the method for manufacturing the polishing liquid. An object of another aspect of the present invention is to provide a method for manufacturing a part using a part to be polished polished by the polishing method. An object of another aspect of the present invention is to provide a method for manufacturing a semiconductor part using a part to be polished polished by the polishing method.

[0010] Means for solving technical problems

[0011] Several aspects of the present invention relate to the following [1] to

[13] and the like.

[0012] [1] A method for selecting a raw material for obtaining abrasive grains, wherein the raw material contains cerium and the raw material is selected based on a peak top temperature in a differential curve of a thermogravimetric curve obtained by thermogravimetric analysis of the raw material.

[0013] [2] The method for selecting a raw material according to [1], wherein the raw material contains cerium oxide.

[0014] [3] A raw material for obtaining abrasive grains, the raw material containing cerium, wherein a peak top temperature in a differential curve of a thermogravimetric curve obtained by thermogravimetric analysis of the raw material is 300° C. or higher.

[0015] [4] The raw material according to [3], comprising cerium oxide.

[0016] [5] The raw material according to [3] or [4], comprising cerium oxide derived from a cerium complex of trimesic acid.

[0017] [6] The raw material according to any one of [3] to [5], comprising cerium oxide derived from cerium stearate.

[0018] [7] The raw material according to any one of [3] to [6], comprising cerium oxide derived from cerium hydroxide.

[0019] [8] A method for producing abrasive grains, comprising pulverizing a raw material selected by the raw material selection method described in [1] or [2], or a raw material described in any one of [3] to [7].

[0020] [9] A method for producing a polishing liquid, comprising mixing abrasive grains obtained by the method for producing abrasive grains according to [8] and water.

[0021]

[10] A polishing method comprising polishing a workpiece using the polishing liquid obtained by the method for producing a polishing liquid according to [9].

[0022]

[11] The polishing method according to

[10] , wherein the polished member contains silicon oxide.

[0023]

[12] A method for manufacturing a part, which obtains the part using a part to be ground by the grinding method described in

[10] or

[11] .

[0024]

[13] A method for manufacturing a semiconductor component, which obtains a semiconductor component using a polished member polished by the polishing method described in

[10] or

[11] .

[0025] Effects of the Invention

[0026] According to one aspect of the present invention, there can be provided a method for selecting a raw material, which is a method for selecting a raw material for obtaining abrasive grains, and the method can adjust the grinding speed of a material to be ground when the material to be ground is ground using the abrasive grains. According to another aspect of the present invention, there can be provided a raw material that can obtain abrasive grains with a high grinding speed of silicon oxide in a pattern area having a linear silicon nitride pattern / silicon oxide pattern with a line width of 50 μm / 50 μm. According to another aspect of the present invention, there can be provided a method for manufacturing abrasive grains using the raw material. According to another aspect of the present invention, there can be provided a method for manufacturing a polishing liquid using abrasive grains obtained by the method for manufacturing the abrasive grains. According to another aspect of the present invention, there can be provided a method for polishing using a polishing liquid obtained by the method for manufacturing the polishing liquid. According to another aspect of the present invention, there can be provided a method for manufacturing a part using a part to be ground by the grinding method. According to another aspect of the present invention, there can be provided a method for manufacturing a semiconductor part using a part to be ground by the grinding method. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0028] In this specification, the numerical range represented by "~" indicates a range including the numerical values ​​recorded before and after "~" as the minimum and maximum values, respectively. "Above A" in the numerical range refers to A and the range exceeding A. "Below A" in the numerical range refers to A and the range less than A. In the numerical range recorded in stages in this specification, the upper limit or lower limit of the numerical range of a certain stage can be arbitrarily combined with the upper limit or lower limit of the numerical range of another stage. In the numerical range recorded in this specification, the upper limit or lower limit of the numerical range can be replaced by the value shown in the experimental example. "A or B" can include either A or B, or both. The materials exemplified in this specification can be used alone or in combination of two or more unless otherwise specified. Regarding the content of each component in the composition, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition. The term "process" is included in this term in addition to independent processes, even if it cannot be clearly distinguished from other processes, as long as the intended effect of the process can be achieved. The term "abrasive grain" refers to a plurality of particles aggregated together, but for convenience, one particle constituting the abrasive grain may be referred to as an abrasive grain.

[0029] The raw material and the selection method thereof involved in the present embodiment are raw materials and the selection method thereof for obtaining abrasive grains (abrasive grains used in polishing liquid). In the raw material and the selection method thereof involved in the present embodiment, the raw material contains cerium. In the selection method of the raw material involved in the present embodiment, the raw material is selected according to the peak top temperature in the differential curve (DTG curve) of the thermogravimetric curve (TG curve) obtained by thermogravimetric analysis (TGA) of the raw material. The raw material involved in the present embodiment has an arbitrary numerical value as the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material according to the use. The shape of the raw material involved in the present embodiment is not particularly limited, for example, it can be granular, fibrous, flaky, liquid (for example, a highly viscous liquid), etc.

[0030] The inventors have found that, as a raw material for obtaining abrasive grains by performing a pulverization treatment or the like, focusing on a raw material containing cerium, the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material is adjusted, thereby adjusting the grinding speed of the material to be ground when the abrasive grains are used to grind the material to be ground. According to the raw material and the selection method thereof involved in the present embodiment, the raw material is selected according to the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material, and the abrasive grains are obtained using such raw material, thereby adjusting the grinding speed of the material to be ground when the abrasive grains are used to grind the material to be ground. According to the raw material and the selection method thereof involved in the present embodiment, when the raw material is subjected to a pulverization treatment (after the pulverization treatment, a specific particle size can be made uniform by a classification treatment) to obtain abrasive grains, the grinding speed of the material to be ground when the abrasive grains are used to grind the material to be ground can be adjusted. According to the present embodiment, a method for adjusting the grinding speed of the material to be ground can be provided, which adjusts the grinding speed of the material to be ground according to the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material for obtaining the abrasive grains.

[0031] According to one aspect of the raw material and the method for selecting the same in the present embodiment, the polishing speed of the material to be polished in the pattern wafer can be adjusted. According to one aspect of the raw material and the method for selecting the same in the present embodiment, the polishing speed of the material to be polished can be adjusted to increase the polishing speed of the material to be polished, and the polishing speed of the material to be polished can be adjusted to decrease the polishing speed of the material to be polished. According to one aspect of the raw material and the method for selecting the same in the present embodiment, the polishing speed of the insulating material can be adjusted, and the polishing speed of silicon oxide can be adjusted.

[0032] The raw material for obtaining the abrasive grains includes cerium (cerium element) and may also include cerium compounds. Examples of cerium compounds include cerium oxide, cerium hydroxide, ammonium cerium nitrate, cerium acetate, cerium sulfate (e.g., cerium sulfate hydrate), cerium bromate, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, cerium carbonate, and the like. From the perspective of easily adjusting the polishing speed of the material to be polished or easily increasing the polishing speed of the material to be polished (the polishing speed of silicon oxide in a pattern wafer, etc.; the same below), the raw material for obtaining the abrasive grains may include cerium oxide. Cerium oxide may be CeO2 (cerium (IV) oxide, cerium dioxide) or Ce2O3 (cerium (III) oxide).

[0033] The raw material for obtaining the abrasive grains can be obtained by oxidizing a cerium source containing cerium. As the oxidation method, there can be cited a calcination method in which the cerium source is calcined at 600 to 900°C or the like; a chemical oxidation method in which the cerium source is oxidized using an oxidant such as hydrogen peroxide, etc. The raw material for obtaining the abrasive grains may include cerium oxide from a cerium source, or may include a calcined product of a cerium source. As the cerium source, a cerium salt may be used, or a cerium complex may be used. The raw material for obtaining the abrasive grains may include cerium oxide from a cerium salt, or may include cerium oxide from a cerium complex.

[0034] From the viewpoint of easily increasing the polishing speed of the material to be polished, the cerium complex may include a cerium complex of compound A having a carbon chain (a complex having a ligand of compound A and cerium). From the viewpoint of easily increasing the polishing speed of the material to be polished, compound A may include at least one selected from the group consisting of a carboxyl group and a carboxylate group. In this case, from the viewpoint of easily increasing the polishing speed of the material to be polished, the number of carboxyl groups or the total number of carboxyl groups and carboxylate groups may be 1 to 4, 1 to 3, 2 to 4, 2 to 3 or 3 to 4. From the viewpoint of easily increasing the polishing speed of the material to be polished, compound A may have at least one selected from the group consisting of a chain (non-cyclic) carbon chain and a cyclic carbon chain, and may also have a cyclic carbon chain. The cyclic carbon chain may be an alicyclic ring, a heterocyclic ring or an aromatic ring. From the viewpoint of easily increasing the polishing speed of the material to be polished, compound A may have an aromatic ring. From the viewpoint of easily increasing the polishing speed of the material to be polished, the cerium complex may include a cerium complex of an aromatic carboxylic acid, a cerium complex of trimesic acid, or a cerium complex of trimesic acid. The cerium complex may contain metal organic frameworks.

[0035] As the cerium source, cerium carbonate (excluding cerium oxycarbonate), cerium oxycarbonate, cerium complex of trimesic acid, cerium acetate, cerium stearate, cerium nitrate, cerium sulfate, cerium oxalate, cerium hydroxide, etc. can be cited. From the viewpoint of easily increasing the polishing speed of the material to be polished, the raw material for obtaining the abrasive grains may include at least one selected from the group consisting of cerium oxide from cerium complex of trimesic acid (for example, a calcined product of cerium complex of trimesic acid), cerium oxide from cerium stearate (for example, a calcined product of cerium stearate), and cerium oxide from cerium hydroxide (for example, a calcined product of cerium hydroxide). That is, the raw material for obtaining the abrasive grains may be a form containing cerium oxide from cerium complex of trimesic acid, a form containing cerium oxide from cerium stearate, or a form containing cerium oxide from cerium hydroxide.

[0036] The inventors have found that by using abrasive grains obtained from a raw material having a peak top temperature of 300°C or more in a differential curve as a thermogravimetric curve, it is easy to increase the polishing rate of silicon oxide in a pattern wafer, and it is found that it is particularly easy to increase the polishing rate of silicon oxide in a pattern region having a linear silicon nitride pattern / silicon oxide pattern with a line width of 50μm / 50μm (a pattern region where a linear silicon nitride pattern with a line width of 50μm and a linear silicon oxide pattern with a line width of 50μm are alternately arranged). One form of the raw material involved in the present embodiment is a raw material for obtaining abrasive grains, which contains cerium, and the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material is 300°C or more. According to this raw material, it is easy to increase the polishing rate of silicon oxide in a pattern wafer, and it is particularly easy to increase the polishing rate of silicon oxide in a pattern region having a linear silicon nitride pattern / silicon oxide pattern with a line width of 50μm / 50μm. According to one mode of the raw material involved in the present embodiment, in the evaluation method described in the experimental examples described later, the polishing speed of silicon oxide in the pattern area of ​​a linear silicon nitride pattern / silicon oxide pattern having a line width of 50μm / 50μm can be, for example, 13nm / min or more (preferably 15nm / min or more, 20nm / min or more, 25nm / min or more, 30nm / min or more, 35nm / min or more, etc.).

[0037] According to one aspect of the raw material involved in the present embodiment, it is easy to increase the polishing speed of silicon oxide in a pattern area having a linear silicon nitride pattern / silicon oxide pattern with a line width of 20 μm / 80 μm (a pattern area where a linear silicon nitride pattern with a line width of 20 μm and a linear silicon oxide pattern with a line width of 80 μm are alternately arranged). According to one aspect of the raw material involved in the present embodiment, in the evaluation method described in the experimental example described later, the polishing speed of silicon oxide in the pattern area having a linear silicon nitride pattern / silicon oxide pattern with a line width of 20 μm / 80 μm can be, for example, 25.5 nm / min or more (preferably 30 nm / min or more, 35 nm / min or more, 40 nm / min or more, 45 nm / min or more, 50 nm / min or more, etc.).

[0038] As an example of the reason why a high polishing rate can be easily obtained by a high peak temperature, the following reasons can be cited. However, the reason why a high polishing rate can be easily obtained is not limited to this content. That is, if the peak temperature in the raw material used to obtain the abrasive is high, it is easy to maintain the reaction field (reaction field) in which the crystallinity of the abrasive obtained using these raw materials becomes high, and it is easy to obtain abrasives with few oxygen defects. In this way, if there are few oxygen defects inside the abrasive, the abrasive is not easy to break during grinding. Therefore, it is easy to obtain sufficient mechanical grinding force of the abrasive, so it is easy to obtain a high polishing rate.

[0039] The method for selecting a raw material according to the present embodiment includes a selection step of selecting a raw material (a raw material for obtaining abrasive grains) based on a peak top temperature in a differential curve of a thermogravimetric curve obtained by thermogravimetric analysis of the raw material. In the selection step, the raw material can be selected based on whether the peak top temperature is within any of the following ranges (for example, whether the peak top temperature is 300° C. or above).

[0040] In the raw materials and the selection method thereof involved in the present embodiment, the peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw materials can be within the following range. From the viewpoint of easily adjusting the polishing speed of the polished material, the peak top temperature can be above 250°C, above 260°C, above 270°C, above 280°C, or above 290°C. From the viewpoint of easily increasing the polishing speed of the polished material (polishing speed of silicon oxide in the pattern wafer, etc.), the peak top temperature can be above 300°C, above 310°C, above 320°C, above 330°C, above 340°C, above 350°C, above 360°C, or above 370°C. From the viewpoint of easily adjusting the polishing speed of the polished material, the peak top temperature can be below 500°C, below 450°C, below 400°C, below 390°C, below 380°C, below 370°C, below 360°C, or below 350°C. From these viewpoints, the peak top temperature may be 250 to 500°C, 300 to 500°C, 350 to 500°C, 250 to 400°C, 300 to 400°C, 350 to 400°C, 250 to 380°C, 300 to 380°C, or 350 to 380°C.

[0041] The peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material can be measured using a thermogravimetric differential thermal analyzer (TG-DTA) under air flow, a measurement temperature range of 27 to 920°C, and a heating rate of 10°C / minute, and can be measured by the method described in the experimental examples described later. In thermogravimetric analysis, the weight change when the raw material is heated can be measured. The peak top temperature can be the peak top temperature of the exothermic peak or the peak top temperature of the endothermic peak. The peak top temperature can be the peak top temperature of the peak accompanied by the glass transition. The peak top temperature can be adjusted by the production conditions of the raw material for obtaining the abrasive, etc. In the case where multiple peaks appear in the differential curve of the thermogravimetric curve, the peak top temperature in the highest temperature peak (for example, a peak below 500°C) is used as the peak top temperature.

[0042] The abrasive grains and the manufacturing method thereof involved in the present embodiment are abrasive grains containing cerium and the manufacturing method thereof. In the manufacturing method of the abrasive grains involved in the present embodiment, the abrasive grains can be obtained by processing the raw materials involved in the present embodiment, for example, the abrasive grains can be obtained by crushing the raw materials involved in the present embodiment. In the manufacturing method of the abrasive grains involved in the present embodiment, the abrasive grains can be obtained by processing the raw materials selected by the raw material selection method involved in the present embodiment, for example, the abrasive grains can be obtained by crushing the raw materials selected by the raw material selection method involved in the present embodiment. The abrasive grains involved in the present embodiment can be abrasive grains obtained by processing the raw materials involved in the present embodiment (abrasive grains obtained by the manufacturing method of the abrasive grains involved in the present embodiment), for example, they can be abrasive grains obtained by crushing the raw materials involved in the present embodiment. The abrasive grains involved in the present embodiment can be abrasive grains obtained by processing the raw materials selected by the raw material selection method involved in the present embodiment, for example, they can be abrasive grains obtained by crushing the raw materials selected by the raw material selection method involved in the present embodiment. The pulverized material according to the present embodiment may be a pulverized material of the raw material according to the present embodiment, or may be a pulverized material of the raw material selected by the method for selecting a raw material according to the present embodiment.

[0043] The abrasive grains contain cerium (cerium element) and may contain cerium compounds. Examples of cerium compounds include cerium oxides, cerium hydroxides, cerium ammonium nitrate, cerium acetate, cerium sulfate (e.g., cerium sulfate hydrate), cerium bromate, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, cerium carbonate, and the like. From the viewpoint of easily increasing the polishing speed of the polished material, the abrasive grains may contain cerium oxides. The cerium oxide may be CeO2 (cerium (IV) oxide, cerium dioxide) or Ce2O3 (cerium (III) oxide).

[0044] The manufacturing method of the abrasive grains involved in the present embodiment may include a processing step of processing the raw material involved in the present embodiment, for example, it may include a pulverizing step of obtaining a pulverized product by pulverizing the raw material involved in the present embodiment. The manufacturing method of the abrasive grains involved in the present embodiment may include a processing step of processing the raw material selected by the raw material selection method involved in the present embodiment, for example, it may include a pulverizing step of obtaining a pulverized product by pulverizing the raw material selected by the raw material selection method involved in the present embodiment. The manufacturing method of the abrasive grains involved in the present embodiment may include a classification step of classifying the pulverized product after the pulverizing step. In the classification step, coarse materials (such as coarse particles) can be removed. There is no particular limitation on the pulverizing method in the pulverizing step, and various pulverizing methods such as wet pulverizing and dry pulverizing can be used. There is no particular limitation on the classification method in the classification step, and centrifugal separation can be cited.

[0045] The polishing liquid involved in this embodiment contains the abrasive involved in this embodiment and water. In addition to abrasive and water, the polishing liquid involved in this embodiment may also contain components other than abrasive and water (for example, various components described later). The multi-liquid polishing liquid involved in this embodiment has a liquid A (first liquid) containing the abrasive involved in this embodiment and water, and a liquid B (second liquid) containing components other than abrasive and water (for example, various components described later) and water. Liquid A may contain components other than abrasive and water (for example, various components described later), or may not contain components other than abrasive and water (for example, various components described later). In the manufacturing method of the polishing liquid involved in this embodiment, the polishing liquid can be obtained by mixing the abrasive involved in this embodiment (for example, the abrasive obtained by the manufacturing method of the abrasive involved in this embodiment) and water, and the polishing liquid can be obtained by mixing the liquid A and liquid B of the multi-liquid polishing liquid involved in this embodiment with each other. Liquid A can be obtained by mixing the abrasive grains involved in this embodiment (for example, abrasive grains obtained by the method for producing abrasive grains involved in this embodiment) and water. Liquid A can be a plurality of liquids, for example, a plurality of liquids having different types of abrasive grains. Liquid B can be a plurality of liquids, for example, a plurality of liquids having different types of components other than abrasive grains and water.

[0046] Based on the total mass of the polishing liquid or the total mass of water, the content of the abrasive grains can be within the following ranges. From the viewpoint of easily increasing the polishing speed of the polished material, the content of the abrasive grains can be 0.01 mass % or more, 0.05 mass % or more, 0.1 mass % or more, 0.2 mass % or more, 0.3 mass % or more, 0.4 mass % or more, or 0.5 mass % or more. From the viewpoint of easily suppressing the increase in the viscosity of the polishing liquid, the agglomeration of the abrasive grains, etc., the content of the abrasive grains can be 10 mass % or less, 8 mass % or less, 5 mass % or less, 3 mass % or less, 1 mass % or less, 0.8 mass % or less, or 0.5 mass % or less. From these viewpoints, the content of the abrasive grains can be 0.01-10 mass %, 0.01-5 mass %, 0.01-1 mass %, 0.05-10 mass %, 0.05-5 mass %, 0.05-1 mass %, 0.1-10 mass %, 0.1-5 mass % or 0.1-1 mass %.

[0047] Water can be contained as the remainder of other components removed from the polishing liquid. Based on the gross mass of the polishing liquid, the content of water can be within the following range. The content of water can be more than 90 mass %, more than 91 mass %, more than 92 mass %, more than 93 mass %, more than 94 mass %, more than 95 mass %, more than 96 mass %, more than 97 mass %, more than 98 mass % or more than 99 mass %. The content of water can be less than 100 mass %, less than 99.9 mass %, less than 99.8 mass %, less than 99.7 mass %, less than 99.6 mass % or less than 99.5 mass %. From these viewpoints, the content of water can be more than 90 mass % and less than 100 mass %, more than 95 mass % and less than 100 mass %, or more than 98 mass % and less than 100 mass %.

[0048] The polishing liquid involved in this embodiment can contain a phosphate compound as needed. The phosphate compound can be used as a dispersant for abrasive particles. As the phosphate compound, at least one selected from the group consisting of phosphates and their derivatives (phosphate derivatives) can be used. As the hydrogen phosphate compound, at least one selected from the group consisting of hydrogen phosphates and their derivatives (hydrogen phosphate derivatives) can be used.

[0049] Examples of the phosphate include potassium phosphate, sodium phosphate, ammonium phosphate, calcium phosphate, and more specifically tripotassium phosphate, trisodium phosphate, ammonium phosphate, tricalcium phosphate, etc. Examples of the phosphate derivative include sodium pyrophosphate, potassium pyrophosphate, potassium polyphosphate, ammonium polyphosphate, calcium polyphosphate, and the like.

[0050] Examples of hydrogen phosphate include potassium hydrogen phosphate, sodium hydrogen phosphate, ammonium hydrogen phosphate, and calcium hydrogen phosphate. Specifically, examples include dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, calcium hydrogen phosphate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, and calcium dihydrogen phosphate. Examples of hydrogen phosphate derivatives include potassium dodecyl hydrogen phosphate, sodium dodecyl hydrogen phosphate, and dodecyl ammonium hydrogen phosphate.

[0051] From the viewpoint of easily increasing the polishing rate of the material to be polished, the polishing liquid according to the present embodiment may contain hydrogen phosphate or diammonium phosphate.

[0052] The content of the phosphate compound may be within the following ranges based on the total mass of the polishing liquid or the total mass of water. From the viewpoint of easily increasing the polishing speed of the polished material, the content of the phosphate compound may be 0.0001 mass % or more, 0.0005 mass % or more, 0.001 mass % or more, 0.002 mass % or more, 0.003 mass % or more, 0.004 mass % or more, 0.005 mass % or more, 0.008 mass % or more, or 0.01 mass % or more. From the viewpoint of easily suppressing the aggregation of abrasive grains, the content of the phosphate compound may be 1 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.08 mass % or less, 0.05 mass % or less, 0.04 mass % or less, 0.03 mass % or less, 0.02 mass % or less, or 0.01 mass % or less. From these viewpoints, the content of the phosphate compound may be 0.0001 to 1 mass %, 0.0001 to 0.1 mass %, 0.0001 to 0.05 mass %, 0.001 to 1 mass %, 0.001 to 0.1 mass %, 0.001 to 0.05 mass %, 0.005 to 1 mass %, 0.005 to 0.1 mass % or 0.005 to 0.05 mass %.

[0053] The content of the phosphate compound may be within the following range relative to 100 parts by mass of the abrasive. From the viewpoint of easily increasing the polishing speed of the polished material, the content of the phosphate compound may be 0.01 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, 0.8 parts by mass or more, 1 parts by mass or more, 1.2 parts by mass or more, 1.5 parts by mass or more, 1.8 parts by mass or more, or 2 parts by mass or more. From the viewpoint of easily suppressing the aggregation of the abrasive, the content of the phosphate compound may be 50 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, 5 parts by mass or less, 4 parts by mass or less, 3 parts by mass or less, 2.5 parts by mass or less, or 2 parts by mass or less. From these viewpoints, the content of the phosphate compound can be 0.01 to 50 parts by mass, 0.01 to 10 parts by mass, 0.01 to 5 parts by mass, 0.1 to 50 parts by mass, 0.1 to 10 parts by mass, 0.1 to 5 parts by mass, 0.5 to 50 parts by mass, 0.5 to 10 parts by mass, 0.5 to 5 parts by mass, 1 to 50 parts by mass, 1 to 10 parts by mass or 1 to 5 parts by mass.

[0054] The polishing liquid involved in this embodiment can contain a polymer as needed. As the polymer, there can be mentioned a single polymer (polyacrylic acid, etc.) of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc.; ammonium salts or amine salts of the single polymer; copolymers of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and monomers such as alkyl acrylates (methyl acrylate, ethyl acrylate, etc.), hydroxyalkyl acrylates (hydroxyethyl acrylate, etc.), alkyl methacrylates (methyl methacrylate, ethyl methacrylate, etc.), hydroxyalkyl methacrylates (hydroxyethyl methacrylate, etc.), styrene compounds (styrene, alkyl styrene, styrene sulfonic acid, etc.), vinyl acetate, vinyl alcohol, etc.; ammonium salts or amine salts of the copolymer, etc. The polishing liquid involved in this embodiment can contain a copolymer having at least one selected from the group consisting of acrylic acid and methacrylic acid and a styrene compound as a monomer unit, and can also contain a copolymer having styrene and acrylic acid as monomer units (styrene / acrylic acid copolymer).

[0055] The polishing liquid involved in this embodiment can contain an acid component (except compounds equivalent to phosphate compounds) as needed. Examples of the acid component include organic acids such as propionic acid and acetic acid (except compounds equivalent to amino acids); inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid; and amino acids such as glycine.

[0056] The polishing liquid according to the present embodiment may contain components other than the abrasive according to the present embodiment, water, a phosphate compound, a polymer, and an acid component. Such components are not particularly limited, and examples thereof include abrasives not containing cerium, and basic compounds.

[0057] From the viewpoint of easily increasing the polishing speed of the polished material, the pH of the polishing liquid involved in this embodiment can be within the following range. The pH of the polishing liquid can be above 1.0, above 1.5, above 2.0, above 2.5, above 3.0, above 3.5, above 4.0, above 4.5, above 5.0, above 5.5, above 6.0, above 6.5, above 7.0, above 7.0, above 7.5, above 8.0 or above 8.5. The pH of the polishing liquid can be below 12.0, below 11.5, below 11.0, below 10.5, below 10.0, below 9.5 or below 9.0. From these viewpoints, the pH of the polishing liquid may be 1.0 to 12.0, 1.0 to 10.0, 1.0 to 9.0, 5.0 to 12.0, 5.0 to 10.0, 5.0 to 9.0, 7.0 to 12.0, 7.0 to 10.0, or 7.0 to 9.0. The pH of the polishing liquid according to the present embodiment can be measured by the method described in the experimental examples described below.

[0058] The polishing method involved in the present embodiment includes a polishing process, wherein the polishing process uses the polishing liquid involved in the present embodiment (for example, the polishing liquid obtained by the manufacturing method of the polishing liquid involved in the present embodiment) to polish the polished part. The polishing liquid used in the polishing process can be a polishing liquid obtained by mixing liquid A (the first liquid) and liquid B (the second liquid) of the multi-liquid polishing liquid involved in the present embodiment. In the polishing process, the polished surface of the polished part can be polished. In the polishing process, at least a part of the polished material in the polished part can be polished and removed. As the polished material, insulating materials such as silicon oxide and silicon nitride can be cited. The polished part can contain silicon oxide, or silicon oxide and silicon nitride. In the polishing process, a pattern area in which a linear silicon nitride pattern with a line width of 50 μm and a linear silicon oxide pattern with a line width of 50 μm are alternately arranged can be polished, and a pattern area in which a linear silicon nitride pattern with a line width of 20 μm and a linear silicon oxide pattern with a line width of 80 μm can be alternately arranged can also be polished. The abrasive particles, polishing liquid, polishing method, etc. involved in this embodiment are not limited to use in the polishing of these polished parts. For example, they can be used in the polishing of other pattern areas, and can also be used in the polishing of non-patterned wafers without patterns. The polished parts are not particularly limited, and can be wafers (such as semiconductor wafers) or chips (such as semiconductor chips). The polished parts can be wiring boards or circuit substrates.

[0059] The manufacturing method of the part involved in the present embodiment includes a part manufacturing process, and the part manufacturing process uses the part to be ground by the grinding method involved in the present embodiment to obtain the part. The part involved in the present embodiment is a part obtained by the manufacturing method of the part involved in the present embodiment. The part involved in the present embodiment is not particularly limited, but can be an electronic part (such as a semiconductor part such as a semiconductor package), a wafer (such as a semiconductor wafer), or a chip (such as a semiconductor chip). As one mode of the manufacturing method of the part involved in the present embodiment, in the manufacturing method of the electronic part involved in the present embodiment, the electronic part is obtained by using the part to be ground by the grinding method involved in the present embodiment. As one mode of the manufacturing method of the part involved in the present embodiment, in the manufacturing method of the semiconductor part involved in the present embodiment, a semiconductor part (such as a semiconductor package) is obtained by using the part to be ground by the grinding method involved in the present embodiment. The manufacturing method of the part involved in the present embodiment may have a grinding process for grinding the part to be ground by the grinding method involved in the present embodiment before the part manufacturing process.

[0060] In the manufacturing method of the part involved in the present embodiment, as one mode of the part manufacturing process, there may be a singulation process of singulating the polished part polished by the polishing method involved in the present embodiment. The singulation process may be, for example, a process of cutting a wafer (e.g., a semiconductor wafer) polished by the polishing method involved in the present embodiment to obtain a chip (e.g., a semiconductor chip). As one mode of the manufacturing method of the part involved in the present embodiment, the manufacturing method of the electronic part involved in the present embodiment may have a process of obtaining an electronic part (e.g., a semiconductor part) by singulating the polished part polished by the polishing method involved in the present embodiment. As one mode of the manufacturing method of the part involved in the present embodiment, the manufacturing method of the semiconductor part involved in the present embodiment may have a process of obtaining a semiconductor part (e.g., a semiconductor package) by singulating the polished part polished by the polishing method involved in the present embodiment.

[0061] In the manufacturing method of the parts involved in the present embodiment, as one mode of the parts manufacturing process, there may be a connection process for connecting (for example, electrically connecting) the part to be ground by the grinding method involved in the present embodiment and other connected bodies. The connected body connected to the part to be ground by the grinding method involved in the present embodiment is not particularly limited, and may be the part to be ground by the grinding method involved in the present embodiment, or may be a connected body different from the part to be ground by the grinding method involved in the present embodiment. In the connection process, the part to be ground and the connected body may be directly connected (the part to be ground and the connected body are connected in a state of contact), or the part to be ground and the connected body may be connected via other components (conductive components, etc.). The connection process can be performed before the singulation process, after the singulation process, or before and after the singulation process.

[0062] The connecting step may be a step of connecting the polished surface of the polished component polished by the polishing method involved in the present embodiment and the connected body, or may be a step of connecting the connecting surface of the polished component polished by the polishing method involved in the present embodiment and the connecting surface of the connected body. The connecting surface of the polished component may be the polished surface polished by the polishing method involved in the present embodiment. Through the connecting step, a connected body having a polished component and a connected body can be obtained. In the connecting step, when the connecting surface of the polished component has a metal part, the connected body can be brought into contact with the metal part. In the connecting step, when the connecting surface of the polished component has a metal part, and when the connecting surface of the connected body has a metal part, the metal parts can be brought into contact with each other. The metal part may, for example, contain copper.

[0063] The device according to the present embodiment (for example, an electronic device such as a semiconductor device) includes at least one selected from the group consisting of a member to be polished by the polishing method according to the present embodiment and the component according to the present embodiment.

[0064] Example

[0065] Hereinafter, the present invention will be specifically described based on experimental examples, but the present invention is not limited to these experimental examples.

[0066] (Preparation of Cerium Oxide Particles)

[0067] The cerium source in Table 1 was calcined in air at 800° C. for 1 hour using an electric furnace to obtain cerium oxide particles (ceria particles).

[0068] The cerium complex (metal organic framework) of trimesic acid is prepared by the following steps. First, a trimesic acid solution is prepared by adding 34.7g (165mmol) of trimesic acid (1,3,5-BTC: 1,3,5-benzenetricarboxylic acid (1,3,5-benzenetricarboxylic acid), manufactured by Tokyo Chemical Industry Co., Ltd.) to 480mL of a water / ethanol mixed solvent (mass ratio 1:1). In addition, an aqueous solution of cerium nitrate was prepared by adding 71.2g (164mmol) of cerium nitrate hexahydrate (manufactured by FUJIFILM Wako Pure Chemical Corporation) to 20mL of water. After obtaining a mixed solution A by adding the above-mentioned cerium nitrate aqueous solution to the above-mentioned trimesic acid solution, the mixed solution A was stirred at 25°C and 400rpm for 5 hours using a magnetic stirrer. After a solid component (white precipitate) was generated in the mixed solution A, the mixed solution A was allowed to stand for 15 hours. After the solid component was redispersed by stirring the mixed solution A, the mixed solution A was placed in a 50mL centrifuge tube and centrifuged at 5000rpm for 5 minutes. After the supernatant after centrifugation was moved to another container, the supernatant was stirred at 25°C and 700rpm, and 25.4g (251mmol, 35mL) of triethylamine (manufactured by FUJIFILM Wako Pure Chemical Corporation) was slowly added to the supernatant to raise pH from 1.0 to 8.4, thereby obtaining a mixed solution B producing a solid component (white precipitate). After the solid component was redispersed by stirring the mixed solution B, the mixed solution B was placed in a 50mL centrifuge tube and centrifuged at 5000rpm for 5 minutes. The supernatant was removed after centrifugation, and 35mL of a water / ethanol mixed solvent (mass ratio 1:1) was placed in a centrifuge tube. After the solid component (white precipitate) was redispersed, centrifugation was carried out for 5 minutes at 5000rpm. After the washing operation (adding a water / ethanol mixed solvent and centrifuging after removing the supernatant) was performed twice, the solvent (washing liquid) was removed. The white solid of the cerium complex of trimesic acid (Ce(1,3,5-BTC)·6H2O) 21.5 g (44.3 mmol) was obtained by drying in a heated vacuum dryer for 39 hours.

[0069] About 10 mg of the cerium oxide particles were subjected to thermogravimetric analysis using a thermogravimetric differential thermal analyzer (TG-DTA, manufactured by Hitachi High-Tech Corporation, product name: TG / DTA7220) under air flow, a measurement temperature range of 27 to 920°C, and a heating rate of 10°C / min, to obtain a differential curve of the thermogravimetric curve. Thereafter, the peak top temperature of the peak in the differential curve was determined. The results are shown in Table 1.

[0070] (Preparation of polishing liquid)

[0071] The cerium oxide particles, ammonium dihydrogen phosphate and water were mixed to obtain a suspension in which the cerium oxide particles contained 5% by mass and the ammonium dihydrogen phosphate contained 2 parts by mass based on the total mass of the suspension.

[0072] The suspension was dispersed for 30 minutes using an ultrasonic dispersing device (manufactured by SND Co., Ltd., product name "US-105"). Then, the cerium oxide particles in the suspension were pulverized (wet pulverized) using a bead mill (manufactured by Ashizawa Finetech Ltd., product name: LaboStarMini, model: DMS65) until the particle size reached about 200 nm.

[0073] After the above-mentioned pulverization treatment, a centrifuge (manufactured by Eppendorf Himac Technologies Co., Ltd., product name: CF-15R) was used to perform classification treatment, thereby removing the coarse particles in the above-mentioned suspension and adjusting the particle size to about 150 nm to obtain an aqueous dispersion of abrasive particles. The classification treatment was performed by placing 50 g of the suspension into a centrifuge tube and centrifuging for 1500 to 3700 min. -1 This was done by centrifugation for 5 minutes.

[0074] The aqueous dispersion was diluted with water to obtain a polishing liquid. The content of the abrasive grains was 0.5% by mass and the content of the diammonium phosphate was 0.01% by mass based on the total mass of the polishing liquid.

[0075] The pH of the polishing liquid was measured using a compact pH meter (manufactured by HORIBA, Ltd., product name: LAQUA twin). Two pH buffers (pH 4.01 and pH 6.86) were used as standard buffers. After two-point calibration of the pH meter, the sensor of the pH meter was placed in the polishing liquid, and the pH was measured after the pH stabilized. The liquid temperature of the standard buffer and the polishing liquid was 25°C. The measurement results are shown in Table 1.

[0076] (Evaluation of polishing characteristics)

[0077] A pattern wafer (PTW) was produced by the following steps. First, a product named "8" SEMATECH864 (Stop on Nitride) manufactured by SEMATECH was prepared. The wafer was a wafer in which a SiN film was formed as a stopper film on a portion of a silicon substrate having a diameter of 200 mm, and a recess was formed by etching the portion of the silicon substrate without the SiN film by 350 nm. Then, a 600 nm SiO2 film was formed on the stopper film and in the recess by a plasma CVD method. Next, by cutting the wafer into 20 mm × 20 mm pieces, a pattern wafer having a pattern area with a line width (L / S; unit μm) of 50 / 50 for the SiN pattern (Line) and the SiO2 pattern (Space), and a pattern area with a line width (L / S; unit μm) of 20 / 80 for the SiN pattern (Line) and the SiO2 pattern (Space) was obtained.

[0078] In a grinding device (manufactured by NANOFATOR Co., Ltd., product name: FACT-200), the pattern wafer is mounted on a bracket for mounting a substrate to which an adsorption pad is attached. The bracket is placed on a fixed plate to which a grinding pad (manufactured by NITTA DuPont Incorporated., product name: IC1010) is attached, so that the grinding surface and the grinding pad face each other. The grinding liquid is supplied to the grinding pad at a supply rate of 5 mL / min, and the pattern wafer is pressed onto the grinding pad at a grinding load of 7 psi (1 psi = 6.9 kPa). At this time, the grinding is continued for 120 min. -1 The platen was rotated at a speed of , and the holder and the substrate were rotated together, thereby polishing for 60 seconds. The polished pattern wafer was fully rinsed with pure water and dried.

[0079] Using a film thickness measuring device (manufactured by Toho Technology Corporation, product name: TohoSpec3100), the thickness change of SiO2 (one site) on SiN in the pattern area of ​​L / S=50 / 50 and the pattern area of ​​L / S=20 / 80 before and after polishing was measured, thereby obtaining the polishing rate of silicon oxide. The results are shown in Table 1.

[0080] [Table 1]

[0081]

Claims

1. A method for selecting a raw material, which is a method for selecting a raw material for obtaining abrasive grains, wherein: The raw material comprises cerium, The raw material is selected based on the peak top temperature in a differential curve of a thermogravimetric curve obtained by subjecting the raw material to thermogravimetric analysis.

2. The method for selecting a raw material according to claim 1, wherein: The raw material includes cerium oxide.

3. A raw material for obtaining abrasive grains, The raw material comprises cerium, The peak top temperature in the differential curve of the thermogravimetric curve obtained by thermogravimetric analysis of the raw material is 300° C. or higher. The raw material according to claim 3 , comprising cerium oxide. The raw material according to claim 3 , comprising cerium oxide derived from a cerium complex of trimesic acid. The raw material according to claim 3 , comprising cerium oxide derived from cerium stearate. The raw material according to claim 3 , comprising cerium oxide derived from cerium hydroxide. 8 . A method for producing abrasive grains, comprising pulverizing a raw material selected by the method for selecting a raw material according to claim 1 or 2 , or a raw material according to any one of claims 3 to 7 . 9 . A method for producing a polishing liquid, comprising mixing abrasive grains obtained by the method for producing abrasive grains according to claim 8 and water. 10 . A polishing method comprising polishing a workpiece using the polishing liquid obtained by the method for producing the polishing liquid according to claim 9 .

11. The grinding method according to claim 10, wherein: The polished member includes silicon oxide. 12 . A method for manufacturing a part, comprising obtaining the part by using a part to be ground by the grinding method according to claim 10 . 13 . A method for producing a semiconductor component, comprising obtaining a semiconductor component by using a component to be polished by the polishing method according to claim 10 .

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