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 the average value of positron lifetime measured by positron annihilation. A starting material for obtaining abrasive grains, said starting material containing cerium and having an average positron lifetime value of 285-360 ps as measured by positron annihilation. 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 a non-patterned non-patterned wafer.

[0009] One aspect of the present invention aims 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 can adjust the grinding speed of a material to be ground when the material to be ground is ground using the abrasive grains. Another aspect of the present invention aims to provide a raw material capable of obtaining abrasive grains with a high grinding speed of silicon oxide in a patternless wafer. Another aspect of the present invention aims to provide a method for manufacturing abrasive grains using the raw material. Another aspect of the present invention aims to provide a method for manufacturing a polishing liquid using abrasive grains obtained by the method for manufacturing the abrasive grains. Another aspect of the present invention aims to provide a polishing method using a polishing liquid obtained by the method for manufacturing the polishing liquid. Another aspect of the present invention aims to provide a method for manufacturing a part using a part to be ground by the grinding method. Another aspect of the present invention aims to provide a method for manufacturing a semiconductor part using a part to be ground by the grinding 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, the raw material comprising cerium, the raw material being selected based on an average value of a positron lifetime measured by a positron annihilation method.

[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 comprising cerium, wherein the average value of the positron lifetime measured by a positron annihilation method is 285 to 360 ps.

[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 cerium oxycarbonate.

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

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

[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 abrasive grains are used to grind the material to be ground. According to another aspect of the present invention, there can be provided a raw material capable of obtaining abrasive grains with a high grinding speed for silicon oxide in a patternless wafer. 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 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 abrasive 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 materials 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 materials and the selection method thereof involved in the present embodiment, the raw materials contain cerium. In the selection method of the raw materials involved in the present embodiment, the raw materials are selected according to the average value (average positron lifetime) of the positron lifetime measured by the positron annihilation method. The raw materials involved in the present embodiment have an arbitrary numerical value as the average value (average positron lifetime) of the positron lifetime (positron lifetime of the raw material) measured by the positron annihilation method according to the use. The shape of the raw materials 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 average value of the positron lifetime of the raw material measured by the positron annihilation method can be 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 average value of the positron lifetime measured by the positron annihilation method, and the abrasive grains are obtained by using the 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, the 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 average value of the positron lifetime in the raw material for obtaining the abrasive grains (the average value of the positron lifetime measured by the positron annihilation method).

[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 non-patterned wafer or the patterned 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 abrasive grains includes cerium (cerium element) and may also include cerium compounds. Examples of cerium compounds include cerium oxide, cerium hydroxide, cerium ammonium nitrate, cerium acetate, cerium sulfate (for example, 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 (polishing speed of silicon oxide in a non-patterned wafer, polishing speed of silicon oxide in a patterned wafer, etc.; the same below), the raw material for obtaining 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 (except cerium carbonate), cerium carbonate, 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 improving the grinding speed of the material to be ground, the raw material for obtaining the abrasive grains can include at least one selected from the group consisting of cerium oxide from cerium carbonate (for example, a calcined product of cerium carbonate), cerium oxide from cerium carbonate (for example, a calcined product of cerium carbonate) and cerium oxide from cerium complex of trimesic acid (for example, a calcined product of cerium complex of trimesic acid). That is, the raw material for obtaining the abrasive grains can be a method containing cerium oxide from cerium carbonate, a method containing cerium oxide from cerium carbonate, or a method containing cerium oxide from cerium complex of trimesic acid.

[0036] In the determination of positron lifetime, atomic-level defects, intermolecular voids, pore structures, etc. can be evaluated by measuring the time until the positrons incident on the material are annihilated. The average value of the positron lifetime is the component from the sample when a three-component analysis is performed using two components, namely, Kapton (heat-resistant plastic film) component and adhesive component, as line source components after the positron lifetime is determined by the positron annihilation method. The average value of the positron lifetime can be used as an indicator of the average value of the size of oxygen defects, for example. The average value of the positron lifetime can be determined by the method described in the experimental examples described later. The average value of the positron lifetime can be adjusted by the production conditions of the raw materials for obtaining the abrasive, etc. For example, there is the following tendency: the higher the calcination temperature of the cerium source, the smaller (shorter) the positron lifetime.

[0037] The inventors have found that by using a raw material having an average value of positron lifetime measured by positron annihilation method of 285 to 360 ps to obtain abrasive grains, it is easy to increase the polishing speed of silicon oxide. One form of the raw material involved in the present embodiment is a raw material for obtaining abrasive grains, which contains cerium, and the average value of the positron lifetime measured by positron annihilation method is 285 to 360 ps. According to these raw materials, it is easy to increase the polishing speed of silicon oxide in a patternless wafer. According to one form of the raw material involved in the present embodiment, in the evaluation method described in the experimental example described later, as the polishing speed of silicon oxide in a patternless wafer, for example, 50 nm / min or more (preferably 70 nm / min or more, 90 nm / min or more, 100 nm / min or more, 110 nm / min or more, 120 nm / min or more, etc.) can be obtained.

[0038] According to one mode of the raw material involved in the present embodiment, it is easy to increase the polishing speed of silicon oxide in the pattern wafer. According to one mode of the raw material involved in the present embodiment, in the evaluation method described in the experimental example described later, as the polishing speed of silicon oxide in the pattern area where L / S=50 / 50, for example, 18nm / min or more (preferably 20nm / min or more, 25nm / min or more, 30nm / min or more, 35nm / min or more, etc.) can be obtained. According to one mode of the raw material involved in the present embodiment, in the evaluation method described in the experimental example described later, as the polishing speed of silicon oxide in the pattern area where L / S=20 / 80, for example, 26nm / min or more (preferably 27nm / min or more, 30nm / min or more, 35nm / min or more, 40nm / min or more, 45nm / min or more, 50nm / min or more, etc.) can be obtained.

[0039] As an example of the reason why a high polishing speed is easily obtained, the following reasons can be cited. However, the reason why a high polishing speed is easily obtained is not limited to this content. That is, the smaller the average value of the positron lifetime in the raw material used to obtain the abrasive, the smaller the oxygen defects in the interior of the raw material, and the smaller the oxygen defects in the interior of the abrasive obtained using these raw materials. Moreover, the oxygen defects in the interior of the abrasive are so small that the abrasive is not easy to break during grinding, and it is easy to obtain sufficient mechanical grinding force of the abrasive. On the other hand, the larger the average value of the positron lifetime in the raw material used to obtain the abrasive, the larger the oxygen defects in the interior of the raw material, and the larger the oxygen defects in the interior of the abrasive obtained using these raw materials. Moreover, the oxygen defects in the interior of the abrasive are so large that the abrasive is easy to break during grinding, but it is easy to obtain sufficient chemical grinding force of the abrasive. Therefore, when the average value of the positron lifetime is within a specific range, a high polishing speed is easily obtained by obtaining sufficient mechanical grinding force and chemical grinding force.

[0040] The method for selecting a raw material according to the present embodiment includes a step of selecting a raw material (a raw material for obtaining abrasive grains) based on an average value of a positron lifetime measured by a positron annihilation method. In the selection step, the raw material can be selected based on whether the average value of the positron lifetime is within any of the following ranges (for example, whether the average value of the positron lifetime is 285 to 360 ps).

[0041] In the raw material and the selection method thereof involved in the present embodiment, from the viewpoint of easily adjusting the polishing speed of the polished material, the average value of the positron lifetime (positron lifetime of the raw material) measured by the positron annihilation method can be within the following range. The average value of the positron lifetime can be 200 ps or more, 250 ps or more, or 280 ps or more. The average value of the positron lifetime can be 500 ps or less, 450 ps or less, 400 ps or less, 390 ps or less, 380 ps or less, or 370 ps or less.

[0042] In the raw materials and the selection method thereof involved in the present embodiment, from the viewpoint of easily adjusting the polishing speed of the polished material or easily increasing the polishing speed of the polished material (polishing speed of silicon oxide in a patternless wafer, polishing speed of silicon oxide in a patterned wafer, etc.), the average value of the positron lifetime (positron lifetime of the raw material) measured by the positron annihilation method can be within the following range. The average value of the positron lifetime can be 285ps or more, 290ps or more, 295ps or more, 300ps or more, 305ps or more, 310ps or more, 315ps or more, 320ps or more, 325ps or more, or 330ps or more. The average value of the positron lifetime can be 360ps or less, 355ps or less, 350ps or less, 345ps or less, 340ps or less, 335ps or less, 330ps or less, 325ps or less, 320ps or less, 315ps or less, 310ps or less, 305ps or less, 300ps or less, or 295ps or less.

[0043] From these viewpoints, the average value of the positron lifetime can be 200-500 ps, ​​200-360 ps, ​​200-330 ps, ​​200-300 ps, ​​285-500 ps, ​​285-360 ps, ​​285-330 ps, ​​285-300 ps, ​​300-500 ps, ​​300-360 ps, ​​300-330 ps, ​​330-500 ps, ​​330-360 ps or 360-500 ps.

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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 %.

[0049] 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 %.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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 %.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The polishing method involved in the present embodiment includes a polishing process, in which 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 part to be polished. The polishing liquid used in the polishing process can be a polishing liquid obtained by mixing liquid A (first liquid) and liquid B (second liquid) of the multi-liquid polishing liquid involved in the present embodiment. In the polishing process, the polished surface of the part to be polished can be polished. In the polishing process, at least a part of the material to be polished in the part to be polished can be polished and removed. As the material to be polished, insulating materials such as silicon oxide and silicon nitride can be cited. The part to be polished can contain silicon oxide, or it can contain silicon oxide and silicon nitride. In the grinding process, a non-patterned wafer without a pattern can be ground, 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, or 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 are alternately arranged. The abrasive particles, grinding liquid, grinding method, etc. involved in this embodiment are not limited to the grinding of these parts to be ground, for example, they can be used for grinding other pattern areas. The parts to be ground are not particularly limited, and can be a wafer (such as a semiconductor wafer) or a chip (such as a semiconductor chip). The parts to be ground can be a wiring board or a circuit substrate.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] Example

[0067] Hereinafter, the present invention will be specifically described based on experimental examples, but the present invention is not limited to these experimental examples.

[0068] (Preparation of Cerium Oxide Particles)

[0069] 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).

[0070] 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.

[0071] (Measurement of Positron Lifetime of Cerium Oxide Particles)

[0072] The average value of the positron lifetime of the cerium oxide particles was measured by the following procedure. The measurement results are shown in Table 1.

[0073] The above-mentioned cerium oxide particles were filled in a cell for powder measurement to a height of 5 mm, and the positron lifetime (positron annihilation lifetime) was measured by the positron annihilation method under the following conditions. Using the measured value of the positron lifetime, three component analyses including the lifetime and intensity of the Kapton and binder contained in the line source were performed. It is known that the lifetime τ1 of the Kapton contained in the line source is 0.38ns, and it is close to the positron lifetime of the sample. Therefore, in order to accurately measure the positron lifetime of the sample, it is necessary to fix the intensity I1 of the Kapton contained in the line source. It is known that I1 is about 20 to 35%, so it is fixed to 30% in this measurement. τ2 is the lifetime of the binder contained in the line source, and I2 corresponding to this lifetime represents the intensity of the binder contained in the line source. The lifetime from cerium oxide obtained by the three component analyses is taken as the average value of the positron lifetime (τ3), and the corresponding intensity is obtained as I3 (I1+I2+I3=100%).

[0074] {Measurement conditions}

[0075] Measuring device: manufactured by TOYO SEIKO CO., LTD., product name "PSA Type L-II"

[0076] Positron source: Thin-film positron source (manufactured by the Japan Isotope Association)

[0077] Total count: 1000000 counts

[0078] (Preparation of polishing liquid)

[0079] 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.

[0080] 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.

[0081] After the above-mentioned pulverization treatment, a centrifuge (manufactured by EppendorfHimac 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.

[0082] 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.

[0083] 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.

[0084] (Evaluation of polishing characteristics)

[0085] A blank wafer (BKW) was produced by the following steps. First, a silicon oxide film (SiO2, initial film thickness: 2000 nm) was prepared on the surface. Next, the wafer was cut into pieces of 20 mm×20 mm to obtain a non-patterned wafer for grinding.

[0086] 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. Then, 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.

[0087] In a grinding device (manufactured by NANOFACTOR Co., Ltd., product name: FACT-200), the above-mentioned wafer (unpatterned wafer or patterned wafer) is mounted on a bracket for mounting a substrate to which an adsorption pad is attached. On a fixed plate to which a grinding pad (manufactured by NITTADuPont Incorporated., product name: IC1010) is attached, the bracket is placed in a manner such that the grinding surface and the grinding pad are opposite to each other. The above-mentioned grinding liquid is supplied to the grinding pad at a supply rate of 5 mL / min, and the 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 substrate were rotated together, thereby polishing for 60 seconds. The polished wafer was fully rinsed with pure water and then dried.

[0088] In the case of the non-patterned wafer, the film thickness was measured using a film thickness measuring device (manufactured by Toho Technology Corporation, product name: TohoSpec3100) at a total of five measuring points, namely, the center point of the polished wafer and four points 7.1 cm away from the center point in the diagonal direction. The polishing speed of the non-patterned wafer was obtained by obtaining the difference between the average value of these film thicknesses and the film thickness at the center point of the wafer before polishing as the film thickness variation. The results are shown in Table 1.

[0089] In the pattern wafer, a film thickness measuring device (manufactured by Toho Technology Corporation, product name: TohoSpec3100) was used to measure the thickness change of SiO2 (one site) on SiN in the pattern area with L / S=50 / 50 and the pattern area with L / S=20 / 80 before and after polishing, thereby obtaining the polishing rate of silicon oxide. The results are shown in Table 1.

[0090] [Table 1]

[0091]

Claims

1. A method for selecting a raw material, which is a method for selecting a raw material for obtaining abrasive grains, The raw material comprises cerium, The raw material is selected based on the average value of the positron lifetime measured by the positron annihilation method.

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 average positron lifetime measured by the positron annihilation method is 285 to 360 ps. The raw material according to claim 3 , comprising cerium oxide. The feedstock according to claim 3 , comprising cerium oxide derived from cerium oxycarbonate. The raw material according to claim 3 , comprising cerium oxide derived from cerium carbonate. 7 . The raw material according to claim 3 , comprising cerium oxide derived from a cerium complex of trimesic acid. 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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