Abrasive grain and method for selecting same, polishing liquid, multi-liquid polishing liquid, polishing method, method for manufacturing component, and method for manufacturing semiconductor component

Abstract

Provided is a method for selecting abrasive grains containing cerium, the abrasive grains being selected on the basis of the average value of positron lifetime measured by positron annihilation. The abrasive grain contains cerium, and the average value of positron lifetime measured by positron annihilation is 360 ps or less. And a polishing liquid containing the abrasive grains and water. A multi-liquid polishing liquid which is provided with: a first liquid that contains the abrasive grains and water; and a second liquid containing water and components other than the abrasive grains and water. And a polishing method for polishing a member to be polished using the polishing liquid.

Description

Technical Field

[0001] The present invention relates to an abrasive grain and a method for selecting the abrasive grain, a polishing liquid, a multi-liquid polishing liquid, a polishing method, a method for manufacturing a part, a method for manufacturing a semiconductor part, etc. 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] For a polishing liquid containing 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 a polishing liquid containing abrasive grains, it is sometimes required to increase the polishing speed of silicon oxide in a non-patterned wafer.

[0009] One aspect of the present invention aims to provide a method for selecting abrasive grains capable of adjusting the polishing speed of a material to be polished. Another aspect of the present invention aims to provide abrasive grains having a high polishing speed for silicon oxide in a patternless wafer. Another aspect of the present invention aims to provide a polishing liquid containing the abrasive grains. Another aspect of the present invention aims to provide a multi-liquid polishing liquid using the abrasive grains. Another aspect of the present invention aims to provide a polishing method using the polishing liquid. Another aspect of the present invention aims to provide a method for manufacturing a part using a part to be polished by the polishing method. Another aspect of the present invention aims to provide a method for manufacturing a semiconductor part using a part to be polished by the polishing method.

[0010] Means for solving technical problems

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

[17] and the like.

[0012] [1] A method for selecting abrasive grains, wherein the abrasive grains contain cerium and the abrasive grains are selected based on an average value of positron lifetimes measured by a positron annihilation method.

[0013] [2] The method for selecting abrasive grains according to [1], wherein the abrasive grains contain cerium oxide.

[0014] [3] An abrasive grain comprising cerium, wherein an average value of a positron lifetime measured by a positron annihilation method is 360 ps or less.

[0015] [4] The abrasive according to [3], wherein an average value of a positron lifetime measured by a positron annihilation method is 300 to 360 ps.

[0016] [5] The abrasive according to [3] or [4], wherein the crystallite diameter is 30 nm or more.

[0017] [6] The abrasive according to any one of [3] to [5], wherein the crystallite diameter is 36 to 50 nm.

[0018] [7] The abrasive grain according to any one of [3] to [6], comprising cerium oxide.

[0019] [8] The abrasive according to any one of [3] to [7], comprising cerium oxide derived from a cerium complex of trimesic acid.

[0020] [9] The abrasive grain according to any one of [3] to [8], comprising cerium oxide derived from cerium hydroxide.

[0021]

[10] The abrasive grain according to any one of [3] to [9], comprising cerium oxide derived from cerium carbonate.

[0022]

[11] The abrasive grain according to any one of [3] to

[10] , comprising cerium oxide derived from cerium oxycarbonate.

[0023]

[12] A polishing liquid comprising abrasive selected by the abrasive selection method described in [1] or [2], or the abrasive described in any one of [3] to

[11] , and water.

[0024]

[13] A multi-liquid polishing liquid comprising: a first liquid containing abrasive and water; and a second liquid containing components other than the abrasive and water and water, wherein the abrasive is abrasive selected by the abrasive selection method described in [1] or [2] or abrasive described in any one of [3] to

[11] .

[0025]

[14] A polishing method, comprising polishing a workpiece using the polishing liquid described in

[12] .

[0026]

[15] The polishing method according to

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

[0027]

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

[14] or

[15] .

[0028]

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

[14] or

[15] .

[0029] Effects of the Invention

[0030] According to one aspect of the present invention, a method for selecting abrasive grains capable of adjusting the polishing speed of a material to be polished can be provided. According to another aspect of the present invention, an abrasive grain having a high polishing speed for silicon oxide in a patternless wafer can be provided. According to another aspect of the present invention, a polishing liquid containing the abrasive grains can be provided. According to another aspect of the present invention, a multi-liquid polishing liquid using the abrasive grains can be provided. According to another aspect of the present invention, a polishing method using the polishing liquid can be provided. According to another aspect of the present invention, a method for manufacturing a part using a part to be polished by the polishing method can be provided. According to another aspect of the present invention, a method for manufacturing a semiconductor part using a part to be polished by the polishing method can be provided. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0032] 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.

[0033] The abrasive grains and the method for selecting the same according to the present embodiment are abrasive grains and the method for selecting the same according to the present embodiment for use in a polishing liquid. In the abrasive grains and the method for selecting the same according to the present embodiment, the abrasive grains contain cerium. In the method for selecting the abrasive grains according to the present embodiment, the abrasive grains are selected based on the average value (average positron lifetime) of the positron lifetime measured by the positron annihilation method. The abrasive grains according to the present embodiment have an arbitrary numerical value as the average value (average positron lifetime) of the positron lifetime (positron lifetime of the abrasive grains) measured by the positron annihilation method, depending on the application.

[0034] The inventors of the present invention have found that, focusing on abrasive grains containing cerium, by adjusting the average value of the positron lifetime of the abrasive grains measured by the positron annihilation method, the grinding speed of the material to be ground can be adjusted when the abrasive grains are used to grind the material to be ground. According to the abrasive grains and the method for selecting the abrasive grains involved in the present embodiment, the abrasive grains can be selected based on the average value of the positron lifetime measured by the positron annihilation method, and the grinding speed of the material to be ground can be adjusted when the abrasive grains are used to grind the material to be ground. 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 based on the average value of the positron lifetime in the abrasive grains (the average value of the positron lifetime measured by the positron annihilation method).

[0035] According to one mode of the abrasive grains and the method for selecting the same according to the present embodiment, the polishing speed of the material to be polished in the plain wafer or the patterned wafer can be adjusted. According to one mode of the abrasive grains and the method for selecting the same according to 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 mode of the abrasive grains and the method for selecting the same according to the present embodiment, the polishing speed of the insulating material can be adjusted, and the polishing speed of silicon oxide can be adjusted.

[0036] The abrasive grains contain cerium (cerium element) and may also contain cerium compounds. Examples of cerium compounds include cerium oxide, cerium hydroxide, 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 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 non-patterned wafer, the polishing speed of silicon oxide in a patterned wafer, etc.; the same below), the abrasive grains may contain cerium oxide. Cerium oxide may be CeO2 (cerium (IV) oxide, cerium dioxide) or Ce2O3 (cerium (III) oxide).

[0037] The abrasive grains may contain cerium oxide derived from a cerium source or a calcined product of a cerium source. As the cerium source, a cerium salt or a cerium complex may be used. The abrasive grains may contain cerium oxide derived from a cerium salt or a cerium complex.

[0038] 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.

[0039] As the cerium source, cerium carbonate (except 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 improving the polishing speed of the polished material, 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 oxycarbonate (for example, a calcined product of cerium oxycarbonate), cerium oxide from cerium complex of trimesic acid (for example, a calcined product of cerium complex of trimesic acid) and cerium oxide from cerium hydroxide (for example, a calcined product of cerium hydroxide). That is, the abrasive grains can be in the form of cerium oxide from cerium carbonate, in the form of cerium oxide from cerium carbonate, in the form of cerium oxide from cerium complex of trimesic acid, or in the form of cerium oxide from cerium hydroxide.

[0040] The abrasive grains involved in this embodiment can be obtained by treating a raw material containing cerium (a raw material for obtaining abrasive grains), for example, by crushing the raw material containing cerium (a raw material for obtaining abrasive grains). The method for manufacturing abrasive grains involved in this embodiment may include a treatment step for treating a raw material containing cerium (a raw material for obtaining abrasive grains), for example, it may include a crushing step for obtaining a crushed product by crushing the raw material containing cerium (a raw material for obtaining abrasive grains). The shape of the raw material containing cerium is not particularly limited, for example, it can be granular, fibrous, flaky, liquid (for example, a highly viscous liquid), etc. The method for manufacturing abrasive grains involved in this embodiment may include a classification step for classifying the crushed product after the crushing step. In the classification step, coarse matter (for example, coarse particles) can be removed. There is no particular limitation on the crushing method in the crushing step, and various crushing methods such as wet crushing and dry crushing can be used. There is no particular limitation on the classification method in the classification step, and centrifugal separation can be cited.

[0041] The manufacturing method of the abrasive grains involved in this embodiment may include the following raw material preparation process: before the treatment process (for example, the pulverization process), the cerium source (for example, the cerium salt) is oxidized to obtain a raw material containing cerium (a raw material for obtaining the abrasive grains). As the oxidation method, a calcination method of calcining the cerium source at 600 to 900° C. or the like; a chemical oxidation method of oxidizing the cerium source using an oxidant such as hydrogen peroxide, etc. can be cited.

[0042] In the determination of positron lifetime, atomic-level defects, intermolecular voids, pore structures, etc. can be evaluated by measuring the time until the positron incident on the material is 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 abrasive, etc. For example, there is a tendency that the higher the calcination temperature of the cerium source when obtaining the raw material containing cerium (the raw material for obtaining abrasives), the smaller (shorter) the positron lifetime.

[0043] The inventors have found that by using abrasives having an average value of positron lifetime of 360 ps or less as measured by the positron annihilation method, it is easy to increase the polishing speed of silicon oxide. One form of the abrasives involved in the present embodiment includes cerium, and the average value of the positron lifetime measured by the positron annihilation method is 360 ps or less. According to these abrasives, it is easy to increase the polishing speed of silicon oxide in a patternless wafer. According to one form of the abrasives 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, 25 nm / min or more (preferably 30 nm / min or more, 50 nm / min or more, 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.

[0044] According to one mode of the abrasive particles 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 abrasive particles 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, 15nm / 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 abrasive particles 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, 25.5nm / 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.

[0045] As an example of the reason for easily obtaining a high polishing rate, the following reasons can be cited. However, the reason for easily obtaining a high polishing rate is not limited to this content. That is, the smaller the average value of the positron lifetime in the abrasive grains, the smaller the oxygen defects in the abrasive grains. In this way, if the oxygen defects in the abrasive grains are small, the abrasive grains are not easy to break during polishing. Therefore, the mechanical polishing force of the abrasive grains is easily maintained high, so it is easy to obtain a high polishing rate.

[0046] In the abrasive and the selection method thereof involved in this embodiment, from the viewpoint of easily adjusting the grinding speed of the material to be ground, the average value of the positron lifetime (positron lifetime of the abrasive) measured by the positron annihilation method can be less than 500 ps, ​​less than 450 ps, ​​less than 400 ps, ​​less than 390 ps, ​​less than 380 ps or less than 370 ps.

[0047] In the abrasive and the method for selecting the abrasive grains 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 non-patterned wafer, polishing speed of silicon oxide in a patterned wafer, etc.), the average value of the positron lifetime (positron lifetime of the abrasive grains) measured by the positron annihilation method can be within the following range. The average value of the positron lifetime can be 360ps or less, 355ps or less, 353ps or less, 350ps or less, 345ps or less, 340ps or less, 335ps or less, or 330ps or less. The average value of the positron lifetime can be 200ps or more, 250ps or more, 280ps or more, 300ps or more, 310ps or more, 320ps or more, 325ps or more, 330ps or more, 335ps or more, 340ps or more, 345ps or more, 350ps or more, or 353ps or more.

[0048] From these viewpoints, the average value of the positron lifetime may be 200 to 500 ps, ​​200 to 360 ps, ​​200 to 350 ps, ​​200 to 330 ps, ​​300 to 500 ps, ​​300 to 360 ps, ​​300 to 350 ps, ​​300 to 330 ps, ​​330 to 500 ps, ​​330 to 360 ps, ​​330 to 350 ps, ​​350 to 500 ps or 350 to 360 ps.

[0049] The method for selecting abrasive grains according to the present embodiment includes a step of selecting abrasive grains based on an average value of positron lifetimes measured by a positron annihilation method. In the selection step, abrasive grains can be selected based on whether the average value of the positron lifetime is within any of the above ranges (e.g., whether the average value of the positron lifetime is less than 360 ps).

[0050] The abrasive grains involved in this embodiment have an arbitrary value as the crystallite diameter according to the purpose. In the selection process of the abrasive grain selection method involved in this embodiment, in addition to the average value of the positron lifetime, the abrasive grains can also be selected based on the crystallite diameter. In the selection process, in addition to the average value of the positron lifetime, the abrasive grains can also be selected based on whether the crystallite diameter is within any range described later (for example, whether the crystallite diameter is 30 nm or more).

[0051] In the abrasive and the method for selecting the abrasive according to the present embodiment, the crystallite diameter of the abrasive may be 10 nm or more, 15 nm or more, 20 nm or more, or 25 nm or more from the viewpoint of easily adjusting the polishing speed of the polished material.

[0052] The inventors have found that by using abrasive grains having a crystallite diameter of more than 30 nm, it is further easy to increase the polishing rate of silicon oxide. It is speculated that the mechanical grinding force of the abrasive grains is high and easy to maintain high due to the large crystallite diameter of the abrasive grains, so it is easy to obtain a high polishing rate. However, the reason for easily obtaining a high polishing rate is not limited to this content.

[0053] In the abrasive grains and the method for selecting the abrasive grains according to the present embodiment, from the viewpoint 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 non-patterned wafer, the polishing speed of silicon oxide in a patterned wafer, etc.), the crystallite diameter of the abrasive grains may be within the following range. The crystallite diameter may be greater than 30 nm, greater than 33 nm, greater than 35 nm, greater than 36 nm, greater than 38 nm, or greater than 40 nm. The crystallite diameter may be less than 100 nm, less than 90 nm, less than 80 nm, less than 70 nm, less than 60 nm, less than 55 nm, less than 50 nm, less than 45 nm, less than 42 nm, less than 40 nm, less than 38 nm, less than 36 nm, or less than 35 nm.

[0054] From these viewpoints, the crystallite diameter can be 10-100nm, 10-50nm, 10-40nm, 20-100nm, 20-50nm, 20-40nm, 30-100nm, 30-50nm, 30-40nm, 35-100nm, 35-50nm, 35-40nm, 36-100nm, 36-50nm, 36-40nm, 40-100nm or 40-50nm.

[0055] As the crystallite diameter of the abrasive grains, the average crystallite diameter of the abrasive grains can be used. The crystallite diameter of the abrasive grains can be measured by the method described in the experimental examples described later. The crystallite diameter of the abrasive grains can be adjusted by the manufacturing conditions of the abrasive grains. For example, there is a tendency that the higher the calcination temperature of the cerium source when obtaining the raw material containing cerium (the raw material for obtaining the abrasive grains), the larger the crystallite diameter.

[0056] The polishing liquid involved in the present embodiment may contain the abrasive and water involved in the present embodiment, and may contain the abrasive and water selected by the abrasive selection method involved in the present embodiment. In addition to abrasive and water, the polishing liquid involved in the present embodiment may also contain components other than abrasive and water (for example, various components described later). The multi-liquid polishing liquid involved in the present embodiment comprises a liquid A (first liquid) containing the abrasive and water involved in the present embodiment, and a liquid B (second liquid) containing components other than abrasive and water (for example, various components described later) and water. The abrasive of liquid A may be abrasive selected by the abrasive selection method involved in the present embodiment. 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 method for manufacturing the polishing liquid involved in the present embodiment, the polishing liquid can be obtained by mixing the abrasive particles involved in the present embodiment (for example, the abrasive particles obtained by the method for manufacturing the abrasive particles involved in the present embodiment) and water, and the polishing liquid can be obtained by mixing the liquid A and the liquid B of the multi-liquid polishing liquid involved in the present embodiment. Liquid A can be obtained by mixing the abrasive particles involved in the present embodiment (for example, the abrasive particles obtained by the method for manufacturing the abrasive particles involved in the present embodiment) and water. Liquid A can be a plurality of liquids, for example, a plurality of liquids having different types of abrasive particles. Liquid B can be a plurality of liquids, for example, a plurality of liquids having different types of components other than abrasive particles and water.

[0057] 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 %.

[0058] 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 %.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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 %.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] Example

[0076] Hereinafter, the present invention will be specifically described based on experimental examples, but the present invention is not limited to these experimental examples.

[0077] (Preparation of Cerium Oxide Particles)

[0078] 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).

[0079] 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.

[0080] (Manufacturing of Abrasive Grains)

[0081] 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.

[0082] 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.

[0083] 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.

[0084] (Measurement of Positron Lifetime of Abrasive Particles)

[0085] The average value of the positron lifetime of the abrasive grains was measured by the following procedure. The measurement results are shown in Table 1.

[0086] The aqueous dispersion was centrifuged using a centrifuge (manufactured by Eppendorf Himac Technologies Co., Ltd., product name: CF-15R) to obtain a solid component by removing the supernatant. The centrifugation was performed by placing 50 g of the suspension in a centrifuge tube and centrifuging for 8000 min. -1 The solid content was dried at 30° C. for 15 hours using a vacuum constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., product name: ADP200), and then the solid content was cracked in a mortar to obtain abrasive grains.

[0087] The above-mentioned abrasive grains 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 strength of the Kapton and binder contained in the source were performed. It is known that the lifetime τ1 of the Kapton contained in the source is 0.38ns, and 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 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 source, and I2 corresponding to this lifetime represents the strength of the binder contained in the 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%).

[0088] {Measurement conditions}

[0089] Measuring device: manufactured by TOYO SEIKO CO., LTD., product name "PSA Type L-II"

[0090] Positron source: Thin-film positron source (manufactured by the Japan Isotope Association)

[0091] Total count: 1000000 counts

[0092] (Measurement of crystallite diameter of abrasive grains)

[0093] In the same manner as the above-mentioned determination of the positron lifetime, abrasive grains were obtained from the above-mentioned aqueous dispersion. Next, a powder X-ray diffraction apparatus (XRD, manufactured by Rigaku Corporation, Ultima IV, divergence upper limit slit 10 mm, divergence slit 1°, scattering slit 1°, absorber Cukβ, receiving slit 0.15 mm, output 40 kV / 20 mA) was used to obtain the diffraction spectrum of the abrasive grains in the range of 2θ=27 to 30°. The measurement was performed under the conditions of a measurement interval of 0.02° / step and a scanning speed of 4 steps / s, and the crystallite diameter (average value) was calculated from the half-value width of the CeO2 (111) peak and the Scherrer formula. As the Scherrer constant, 0.89 was used. The measurement results are shown in Table 1.

[0094] (Preparation of polishing liquid)

[0095] 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.

[0096] 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.

[0097] (Evaluation of polishing characteristics)

[0098] A blank wafer (BKW) was produced by the following steps. First, a φ200 mm blank wafer having a silicon oxide film (SiO2, initial film thickness: 2000 nm) on the surface was prepared. Next, the blank wafer for grinding was obtained by cutting the wafer into 20 mm×20 mm.

[0099] 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.

[0100] 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 NITTA DuPont 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.

[0101] 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.

[0102] 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.

[0103] [Table 1]

[0104]

Claims

1. A method for selecting abrasive particles, wherein: The abrasive grains contain cerium, The abrasive grains are selected based on the average value of the positron lifetime measured by positron annihilation method.

2. The method for selecting abrasive particles according to claim 1, wherein: The abrasive grains contain cerium oxide.

3. An abrasive grain comprising cerium, The average value of the positron lifetime measured by the positron annihilation method is 360 ps or less.

4. The abrasive grain according to claim 3, wherein The average lifetime of a positron measured by the positron annihilation method is 300 to 360 ps. The abrasive grain according to claim 3 , wherein the crystallite diameter is 30 nm or more. The abrasive grain according to claim 3 , wherein the crystallite diameter is 36 to 50 nm. The abrasive grain according to claim 3 , comprising cerium oxide. The abrasive grain according to claim 3 , comprising cerium oxide derived from a cerium complex of trimesic acid. 9 . The abrasive grain according to claim 3 , comprising cerium oxide derived from cerium hydroxide.

10. The abrasive grain according to claim 3, comprising cerium oxide derived from cerium carbonate. The abrasive grain according to claim 3 , comprising cerium oxide derived from cerium oxycarbonate. 12 . A polishing liquid comprising the abrasive according to claim 3 and water. 13 . A multi-liquid polishing liquid comprising: a first liquid containing the abrasive according to claim 3 and water; and a second liquid containing a component other than the abrasive and water and water.

14. A polishing method, comprising polishing a workpiece using the polishing liquid according to claim 12.

15. The grinding method according to claim 14, wherein: The polished member includes silicon oxide. 16 . A method for manufacturing a part, comprising obtaining the part by using a member to be ground by the grinding method according to claim 14 . 17 . A method for producing a semiconductor component, comprising obtaining a semiconductor component by using a member to be ground by the grinding method according to claim 14 .

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