WO2018147148A1 - Polishing composition - Google Patents

Abstract

Provided are: a polishing composition which can achieve both of a high polishing rate and a reduced edge roll-off amount while reducing an abrasive grain content; and a polishing composition which can produce a polished surface having good flatness and having a small difference in thickness between a near-edge part of a polished object and the center part of the polished object. Each of the polishing compositions provided herein comprises abrasive grains, water and an amine compound containing no ether bond, wherein the amine compound satisfies at least one of requirements (1) and (2) as mentioned below and the abrasive grain content in the polishing composition is 2% by weight or less: (1) the compound has a hydrocarbon group having at least three carbon atoms between two primary amino groups in the molecule and has no ether bond; and (2) the compound has a primary amino group and at least one of a secondary amino group and a tertiary amino group and has no ether bond. Alternatively, the polishing composition provided herein comprises abrasive grains, water, a roll-up amine compound A and a roll-off compound B.

Description

Polishing composition

The present invention relates to a polishing composition. This application claims priority based on Japanese Patent Application No. 2017-21539 filed on Feb. 8, 2017 and Japanese Patent Application No. 2017-68256 filed on Mar. 30, 2017. The entire contents of these applications are hereby incorporated by reference.

The surface of a silicon wafer used as a component of a semiconductor product is generally finished to a high-quality mirror surface through a lapping process and a polishing process. The polishing process typically includes a preliminary polishing process and a final polishing process. Examples of technical documents relating to the polishing composition include Patent Documents 1 to 5.

Japanese Patent Application Publication No. 2007-53298 Japanese Patent Application Publication No. 2016-124943 International Publication No. 2011/135949 International Publication No. 2012/005289 Japanese Patent Application Publication No. 2014-216464

In recent years, there is a demand for reducing the amount of abrasive grains used in polishing compositions used for polishing semiconductor products such as silicon wafers and other products from the viewpoint of cost reduction. However, when the amount of abrasive grains used is reduced, there is a drawback that the polishing rate is greatly reduced. In this regard, Patent Literature 1 describes that the polishing rate of a silicon wafer is improved by adding a compound such as ethylenediamine to a polishing composition used for polishing a silicon wafer. However, if a compound such as ethylenediamine is included, the polishing rate can be improved, but the periphery of the edge of the silicon wafer is excessively polished compared to the center, so that the thickness of the outer periphery after polishing is reduced. An undesirably decreasing event (edge roll-off) may occur. Such an event is also observed when polishing with a polishing composition containing a general basic compound. Examples of common basic compounds include potassium hydroxide. Patent Document 2 describes that by adding a water-soluble polymer to the polishing composition, the water-soluble polymer is adsorbed on the peripheral portion of the silicon wafer and edge roll-off can be suppressed. However, the adsorbed water-soluble polymer protects the silicon wafer, thereby reducing the polishing rate.

The present invention has been made in view of the above circumstances, and as a first object, polishing capable of achieving both a high polishing rate and a reduced edge roll-off amount while keeping the content of abrasive grains low. It is an object to provide a composition for use.

On the other hand, in order to make maximum use of the area of the silicon wafer, there is a demand for a polishing composition that can realize a polished surface with good flatness with little difference in thickness between the vicinity of the edge and the center.

The present invention has been made in view of the above circumstances, and as a second object, a polishing composition capable of realizing a polished surface with good flatness with little thickness difference between the vicinity of the edge and the central portion. The purpose is to provide.

According to the present specification, a polishing composition is provided. This polishing composition has abrasive grains, water, and the following conditions: (1) a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule, and an ether bond. And (2) at least one of (1) a primary amino group, at least one of a secondary amino group and a tertiary amino group, and no ether bond; An ether compound containing no ether bond and a content of the abrasive is 2% by weight or less. According to this configuration, in a polishing composition containing a low concentration of abrasive grains, a high polishing rate and a reduced edge roll-off amount can be achieved at a higher level.

In a preferred embodiment of the polishing composition disclosed herein, the content of the amine compound not containing an ether bond is less than 1% by weight. Within the range of the content of such an amine bond-free amine compound, both the polishing rate and the ability to reduce the edge roll-off amount can be realized at a higher level.

In a preferred embodiment of the polishing composition disclosed herein, the content of the abrasive grains is less than 1% by weight. In the polishing composition containing such low-concentration abrasive grains, the effect of improving the polishing rate and the effect of reducing the edge roll-off amount are suitably realized at a lower cost.

In a preferred embodiment of the polishing composition disclosed herein, the abrasive grains are silica particles. By using silica particles as the abrasive grains, the effect of improving the polishing rate and the effect of reducing the edge roll-off amount due to the amine compound not containing an ether bond are more suitably exhibited.

Alternatively, in another preferred embodiment of the polishing composition disclosed herein, the polishing composition comprises abrasive grains, water, a roll-up amine compound A, and a roll-off compound B. Thus, by using the roll-up amine compound A and the roll-off compound B in combination, it is possible to realize a polished surface having good flatness with little difference in thickness between the vicinity of the edge and the central portion.

In a preferred embodiment of the polishing composition disclosed herein, the roll-up amine compound A has the following conditions:
(1) having a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule and having no ether bond; and
(2) having a primary amino group and at least one of a secondary amino group and a tertiary amino group, and having no ether bond;
An ether bond-free amine compound that satisfies at least one of the following. Such an ether bond-free amine compound can effectively contribute to edge flattening.

In a preferred embodiment of the polishing composition disclosed herein, the roll-off compound B includes the following compounds:
(B1) at least one basic compound selected from the group consisting of ammonia, ammonium hydroxide, phosphonium hydroxide and metal hydroxide;
(B2) an amine compound having at least one of a secondary amino group and a tertiary amino group and not having a primary amino group;
(B3) an amine compound containing an ether bond in the molecule; and (B4) an amine compound having a hydrocarbon group having 1 or 2 carbon atoms between two primary amino groups in the molecule;
At least one compound selected from the group consisting of: Such a roll-off compound B can effectively contribute to edge flattening.

In a preferred embodiment of the polishing composition disclosed herein, the molar concentration ratio of the roll-up amine compound A and the roll-off compound B (roll-up amine compound A: roll-off compound B) is 1: 500 to 200: 1 range. When it is within the range of the molar concentration ratio of the roll-up amine compound A and the roll-off compound B, the edge flattening effect can be more suitably exhibited.

In a preferred embodiment of the polishing composition disclosed herein, the abrasive grains are silica particles. By using silica particles as the abrasive grains, the edge flattening effect can be more suitably exhibited.

The polishing composition disclosed herein can be preferably applied to polishing of silicon, for example, polishing of silicon after lapping. As a particularly preferable application object, silicon preliminary polishing is exemplified.

Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

<Amine compound containing no ether bond>
The polishing composition according to the first aspect provided by this specification has the following conditions:
(1) having a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule and having no ether bond; and
(2) having a primary amino group and at least one of a secondary amino group and a tertiary amino group, and having no ether bond;
And an ether compound containing no ether bond. Thereby, in the polishing composition containing a low concentration of abrasive grains, the edge roll-off amount can be effectively reduced at the end face after polishing while maintaining a high polishing rate. The reason why such an effect is obtained is not particularly limited, but may be considered as follows, for example. That is, the ether bond-free amine compound has a plurality of amino groups exhibiting strong basicity in the polishing composition, so that chemical polishing of the surface of the polishing object is promoted and the surface is efficiently scraped. Further, it has a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule (or a primary amino group and at least one amino group of a secondary amino group and a tertiary amino group). And a primary amino group with little steric hindrance can exhibit a high adsorption ability to the object to be polished. For this reason, the amine compound is appropriately adsorbed on the outer peripheral portion of the object to be polished at the time of polishing to protect the outer peripheral portion, so that the outer peripheral portion is less likely to be scraped excessively than the central portion. This is considered to contribute to the reduction of the edge roll-off amount.

As the ether bond-free amine compound according to the first aspect disclosed herein, various materials having the above structure can be used alone or in appropriate combination. For example, the ether bond-free amine compound may be an aliphatic polyamine compound, a heterocyclic polyamine compound, or an aromatic polyamine compound having the above structure. In these polyamine compounds, one or more hydrogen atoms bonded to carbon atoms constituting the main chain are each independently a substituent other than a hydrogen atom (for example, a hydroxyl group, a halogen group (for example, F, Cl, You may use the amine compound substituted by Br) etc.). The number of amino groups in the amine compound not containing an ether bond (that is, the total number of primary amino groups, secondary amino groups, and tertiary amino groups) is, for example, 2 to 10, preferably 2 to 8, more preferably 2 to 6, more preferably 2 to 5 (eg 2 to 4). In the case of an amine compound that satisfies the above condition (1), the number of primary amino groups in the compound is not particularly limited as long as it is 2 or more per molecule, but it is typically 2 to 10, preferably It is 2 to 8, more preferably 2 to 6, and further preferably 2 to 4 (for example, 2 or 3). The number of carbon atoms of the hydrocarbon group between two primary amino groups in the molecule is not particularly limited as long as it is 3 or more, but typically 3 to 15, preferably 3 to 12, and more preferably 4 To 10, more preferably 4 to 8. In the case of an amine compound that satisfies the above condition (2), the number of primary amino groups in the compound is not particularly limited as long as it is 1 or more per molecule, but typically 1 to 8, The number is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3 (for example, 1 or 2). The total number of secondary amino groups and tertiary amino groups is not particularly limited as long as it is one or more per molecule, but is, for example, 1 to 8, preferably 1 to 6, more preferably 1 to 4, Preferably it is 1 to 3 (for example, 1 or 2).

As a particularly preferable example in the technique disclosed herein, an ether bond-free amine compound (hereinafter, also referred to as “amine compound a”) represented by the following general formula (a) can be given.
R ¹ —N (R ² ) — (CH ₂ ) _n —NH ₂ (a)
(Wherein R ¹ and R ² are each independently selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyalkyl group and an aminoalkyl group. R ¹ and R ² are bonded to each other to form a cyclic structure. N is an integer of 1 to 15. — (CH ₂ ) _n — may have a branched chain, provided that when both R ¹ and R ² are hydrogen atoms, n is It is an integer from 3 to 15.)

In the amine compound a, the substituents R ¹ and R ² on the nitrogen atom constituting the amino group can be a hydrogen atom, an alkyl group, a hydroxyalkyl group, or an aminoalkyl group. The alkyl group, hydroxyalkyl group and aminoalkyl group may be linear, branched or cyclic. The total number of carbon atoms in the alkyl group, hydroxyalkyl group and aminoalkyl group may be 1 to 15 (preferably 1 to 12, more preferably 1 to 10, and even more preferably 2 to 6). R ¹ and R ² may be the same or different. R ¹ and R ² may be bonded to each other to form a cyclic structure. When R ¹ and R ² are alkyl groups, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Group, propyl group and butyl group are preferable, and ethyl group is particularly preferable. The term “butyl group” as used herein is a concept including various structural isomers (n-butyl group, isobutyl group, sec-butyl group and tert-butyl group). The same applies to other alkyl groups, hydroxyalkyl groups and aminoalkyl groups. The hydroxyalkyl group may be a group having a structure in which one or more hydrogen atoms of the alkyl group are substituted with a hydroxyl group. When R ¹ and R ² are hydroxyalkyl groups, examples thereof include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, and the like, and particularly preferably a hydroxyethyl group. The aminoalkyl group may be a group having a structure in which one or more hydrogen atoms of the alkyl group are substituted with an amino group. When R ¹ and R ² are aminoalkyl groups, for example, aminomethyl group, aminoethyl group, aminopropyl group, aminobutyl group, methylaminoethyl group, dimethylaminoethyl group, 2- (2-aminoethylamino) ethyl A 2- (2-aminoethylamino) ethyl group is particularly preferable. In the amine compound a, n represents the number of repetitions of (CH ₂ ). n is an integer of 1 to 15, preferably 1 to 10, more preferably 1 to 8, and still more preferably 1 to 6 (eg, 1 to 4, typically 2 or 3). However, when both R ¹ and R ² are hydrogen atoms, n is an integer of 3 to 15, preferably 3 to 10, more preferably 4 to 8, and further preferably 6 to 8.

A preferred example of the amine compound a is one in which both R ¹ and R ² are hydrogen atoms. For example, amine compound a1 in which both R ¹ and R ² are hydrogen atoms and (CH ₂ ) repeat number n is 3 to 10 is preferable. Specific examples of such an amine compound a1 include trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine; and the like. Of these, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine are preferable, and hexamethylenediamine is particularly preferable.

Other preferred examples of the amine compound a include those in which R ¹ and R ² are different from each other. For example, ^one of R ¹ and R ² is a hydrogen atom, the other is an alkyl group having 1 to 4 carbon atoms (preferably 1 to 3, typically 1 or 2), and (CH ₂ ) Is preferably an amine compound a2 having a repeating number n of 2-6. Specific examples of such amine compound a2 include N-methylethylenediamine, N-ethylethylenediamine, N-propylethylenediamine, N-methyltrimethylenediamine, N-ethyltrimethylenediamine, N-methyltetramethylenediamine, and N-ethyl. Tetramethylenediamine, N-methylpentamethylenediamine, N-ethylpentamethylenediamine, N-methylhexamethylenediamine, N-ethylhexamethylenediamine; and the like. Of these, N-methylethylenediamine, N-ethylethylenediamine, N-propylethylenediamine, and N-methyltrimethylenediamine are preferable, and N-ethylethylenediamine is particularly preferable.

As another example of the amine compound a, both R ¹ and R ² are alkyl groups having 1 to 4 carbon atoms (preferably 1 to 3, typically 1 or 2), and (CH ₂ ) Amine compound a3 having a repeating number n of 2-6. Specific examples of such amine compound a3 include N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N-ethylmethylethylenediamine, N, N-dipropylethylenediamine, N, N-dimethyltrimethylenediamine, Examples include N, N-diethyltrimethylenediamine, N, N-dimethyltetramethylenediamine, N, N-diethyltetramethylenediamine; and the like.

As another preferred example of the amine compound a, ^one of R ¹ and R ² is a hydrogen atom or an alkyl group, and the other is 1 to 4 carbon atoms (preferably 1 to 3, typically 1 or An amine compound a4 that is a hydroxyalkyl group of ₂ ) and that has a (CH ₂ ) repeat number n of 2 to 6. As specific examples of such amine compound a4, 2- (aminomethylamino) ethanol, 2- (2-aminoethylamino) ethanol, 2- [aminomethyl (methyl) amino] ethanol, 2- (aminomethylamino) Propanol, 2- (2-aminoethylamino) propanol, 2- [aminomethyl (methyl) amino] propanol, 2- (aminomethylamino) butanol, 2- (2-aminoethylamino) butanol, 2- [aminomethyl (Methyl) amino] butanol; Of these, 2- (aminomethylamino) ethanol, 2- (2-aminoethylamino) ethanol, and 2- [aminomethyl (methyl) amino] ethanol are preferable, and 2- (2-aminoethylamino) ethanol is particularly preferable. preferable.

As another preferred example of the amine compound a, ^one of R ¹ and R ² is a hydrogen atom or an alkyl group, and the other is an aminoalkyl group having 1 to 6 (preferably 1 to 4) carbon atoms. And an amine compound a5 in which the number n of (CH ₂ ) repeats is 2 to 6. Specific examples of such amine compound a5 include diethylenetriamine, triethylenetetramine, tetraethylpentamine, heptaethyleneoctamine, nonaethylenedecane, tris (2-aminoethyl) amine, tris (3-aminopropyl) amine; etc. Is exemplified. Of these, triethylenetetramine, tetraethylpentamine, and heptaethyleneoctamine are preferable, and triethylenetetramine is particularly preferable.

Other preferred examples of the amine compound a include an amine compound a6 in which R ¹ and R ² are bonded to each other to form a cyclic structure, and the (CH ₂ ) repeat number n is 2 to 6. Can be mentioned. Specific examples of such amine compound a6 include N-aminomethylpiperazine, N- (2-aminoethyl) piperazine, N- (2-amino-1-methylethyl) piperazine, N-aminopropylpiperazine, N-amino. Butylpiperazine, N-aminohexylpiperazine, N-aminooctylpiperazine, N- (4-amino-2,2-dimethylbutyl) piperazine, 1,4-bis (2-aminoethyl) piperazine, 1,4-bis ( 3-aminopropyl) piperazine, N- (2-aminoethyl) piperazine; and the like. Of these, N- (2-aminoethyl) piperazine is preferable.

It is appropriate that the content of the amine compound not containing an ether bond in the polishing composition is usually 0.01% by weight or more. From the viewpoint of the polishing rate, the content is preferably 0.05% by weight or more, and more preferably 0.1% by weight or more (for example, 0.15% by weight or more). In addition, the content of the amine bond-free amine compound is usually suitably less than 1% by weight and 0.9% by weight or less from the viewpoint of achieving both high polishing rate and reduced edge roll-off. Preferably, it is 0.8% by weight or less (for example, 0.7% by weight or less, or 0.6% by weight or less).

The polishing composition according to the second aspect provided by this specification includes a roll-up amine compound A and a roll-off compound B. Here, the roll-up amine compound A refers to a compound having an action of causing an edge roll-up in which the vicinity of the edge of the polished product becomes thicker than the central portion when added to the polishing composition. In addition, the roll-off compound B refers to a compound that exhibits an action of causing an edge roll-off in which the vicinity of the edge of the polished product becomes thinner than the center portion when added to the polishing composition. In the technique disclosed here, the roll-up amine compound A and the roll-off compound B having such a reciprocal action are used in combination, so that there is little difference in thickness between the vicinity of the edge and the center of the polished product after polishing. A polished surface with good flatness can be realized.

From the viewpoint of better exerting the effect of using roll-up amine compound A and roll-off compound B in combination, the molar ratio of roll-up amine compound A and roll-off compound B (roll-up amine compound A: roll-off compound) B) is preferably in the range of 1: 500 to 200: 1. By using the roll-up amine compound A and the roll-off compound B in combination at a specific molar concentration ratio, the edge flattening effect can be more suitably exhibited. In the technique disclosed herein, the molar ratio of roll-up amine compound A and roll-off compound B is 1: 100 to 100: 1, preferably 1:50 to 50: 1, more preferably 1:30 to 30. : 1, more preferably 1:20 to 20: 1.

<Roll-up amine compound A>
As described above, the roll-up amine compound A is a compound that exhibits an action of causing edge roll-up when added to the polishing composition. The roll-up amine compound A in the present application is a standard polishing in which a silicon wafer is polished under the following conditions using a polishing composition having a silica abrasive grain concentration of 0.5% by mass obtained by dissolving the compound A in water and adjusting the pH to 11.0. After the test, a relatively flat region at a position of 2.0 mm to 4.0 mm from the outer peripheral edge to the center of the silicon wafer is used as a reference point, and the silicon wafer shape displacement amount at the 0.5 mm position from the outer peripheral edge and the reference point described above. roll-off amount X _a calculated as the difference between the, shows the positive value (i.e. X _a> 0). The roll-off amount _{X A} is preferably 10nm or more, more preferably 30nm or more, more preferably 50nm or more. Roll off quantity _{X A} are, for example 70nm or more, and typically may be at 100nm or more, more may be 150nm or more. Further, the roll-off amount _{X A,} from the viewpoint of blending ratio easily adjusted with the roll-off compound B, for example 500nm or less, and typically may also be 400nm or less, and further may be 300nm or less.
[Standard polishing test conditions]
Polishing machine: Desktop polishing machine manufactured by Nippon Engis Co., Ltd. Model “EJ-380IN”
Polishing pad: Product name “MH S-15A” manufactured by Nittahs
Polishing pressure: 16.8 kPa
Surface plate rotation speed: 50 rotations / minute Head rotation speed: 40 rotations / minute Polishing allowance: 8 μm
Polishing liquid supply rate: 100 mL / min
Polishing liquid temperature: 25 ° C

The roll-up amine compound A is not particularly limited as long as it is an amine compound that can be added to the polishing composition to cause the edge roll-up. For example, the roll-up amine compound A is preferably an amine compound having at least one primary amino group. The number of primary amino groups in the roll-up amine compound A is, for example, 1 to 10, preferably 1 to 8, more preferably 1 to 6, and further preferably 1 to 4.

For example, the roll-up amine compound A has the following conditions:
(1) having a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule and having no ether bond; and
(2) having a primary amino group and at least one of a secondary amino group and a tertiary amino group and having no ether bond;
An ether bond-free amine compound satisfying at least one of the above can be used. The ether bond-free amine compound has a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule (or a primary amino group, a secondary amino group and a tertiary amino group). The primary amino group having high hydrophobicity and less steric hindrance can exhibit a high adsorption ability to the object to be polished. For this reason, the amine compound is appropriately adsorbed on the outer peripheral portion of the object to be polished at the time of polishing to protect the outer peripheral portion, so that the outer peripheral portion is less likely to be scraped excessively than the central portion. This is considered to contribute to the roll-up near the edge.

As the ether bond-free amine compound according to the second aspect disclosed herein, the same compound as the ether bond-free amine compound according to the first aspect may be used, and thus detailed description thereof is omitted.

<Roll-off compound B>
As described above, the roll-off compound B is a compound that exhibits an effect of causing edge roll-off when added to the polishing composition. The roll-off compound B in the present application is a standard for polishing a silicon wafer under the above-mentioned standard polishing conditions using a polishing composition having a silica abrasive grain concentration of 0.5 mass% prepared by dissolving the compound B in water and adjusting the pH to 11.0. After the polishing test, a relatively flat region at a position of 2.0 mm to 4.0 mm from the outer peripheral edge to the center of the silicon wafer is used as a reference point, and the silicon wafer shape displacement amount at the 0.5 mm position from the outer peripheral edge and the above reference roll off quantity X _B which is calculated as the difference between the points, showing a negative value (i.e. X _{B <0).} The roll off quantity _{X B} is preferably -10nm or less, more preferably -50nm, more preferably not more than -100 nm. Further, the roll-off amount X _B may be, for example, −1000 nm or more, typically −300 nm or more, more preferably −200 nm or more, from the viewpoint of ease of adjusting the blending ratio with the roll-up amine compound A. Further, it is preferably −150 nm or more, particularly −120 nm or more.

(Basic compound B1)
The roll-off compound B is not particularly limited as long as it is a compound that can cause the edge roll-off when added to the polishing composition.
For example, the roll-off compound B may be at least one basic compound B1 selected from the group consisting of ammonia, ammonium hydroxide, phosphonium hydroxide, and metal hydroxide. The basic compound as used herein refers to a basic compound that generates hydroxide ions when dissolved in water, and may have a function of increasing the pH of the composition when added to the polishing composition. . Such a basic compound B1 may be an organic basic compound or an inorganic basic compound. Basic compound B1 can be used individually by 1 type or in combination of 2 or more types.

Examples of organic basic compounds include quaternary ammonium hydroxides such as tetraalkylammonium hydroxide. For example, quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide can be preferably used. Of these, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferable.
Other examples of organic basic compounds include quaternary phosphonium hydroxides. For example, tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrapropylphosphonium hydroxide, tetrabutylphosphonium hydroxide can be preferably used.

Examples of inorganic basic compounds include ammonia; ammonia, alkali metal or alkaline earth metal hydroxides. Specific examples of the hydroxide include potassium hydroxide and sodium hydroxide.

Preferred examples of the basic compound B1 include potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide. Of these, potassium hydroxide, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferred. More preferred are potassium hydroxide and tetramethylammonium hydroxide.

(Amine compound B2)
Other suitable examples of the roll-off compound B disclosed herein include an amine compound B2 having a secondary amino group and / or a tertiary amino group and having no primary amino group. The amine compound B2 is preferably an amine compound having at least one tertiary amino group. The total number of secondary amino groups and tertiary amino groups in the amine compound B2 is, for example, 1 to 12, preferably 1 to 10, more preferably 1 to 8, and further preferably 1 to 4.

Examples of the amine compound B2 that is particularly preferable in the technology disclosed herein include an amine compound b2 represented by the following general formula (b2).
R ³ —NR ⁴ —R ⁵ (b2)
(Wherein R ³ , R ⁴ and R ⁵ are each independently selected from a hydrogen atom, an alkyl group having 1 to 15 carbon atoms and an aminoalkyl group having no primary amino group, provided that at least two of R ^{3, R} 4, ^{R 5 are, .R 3, R 4, R} 5 is a group other than a hydrogen atom, have a double bond between C-C or between C-N R ³ and R ⁵ may be bonded to each other to form a cyclic structure.)

In the amine compound b2, the substituents R ³ , R ⁴ , and R ⁵ on the nitrogen atom constituting the amino group can be a hydrogen atom, an alkyl group, and an aminoalkyl group that does not have a primary amino group. The alkyl group and aminoalkyl group may be linear, branched or cyclic. The total number of carbon atoms in the alkyl group and aminoalkyl group may be 1 to 15 (preferably 1 to 12, more preferably 1 to 10, and even more preferably 2 to 6). R ³ , R ⁴ and R ⁵ may be the same or different. When R ³ , R ⁴ or R ⁵ is an alkyl group, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Of these, a methyl group, an ethyl group, a propyl group, and a butyl group are preferable, and an ethyl group is particularly preferable. The alkyl group may have a double bond between C—C. When R ³ , R ⁴ , and R ⁵ are aminoalkyl groups, examples thereof include a methylaminomethyl group, a dimethylaminomethyl group, a methylaminoethyl group, a dimethylaminoethyl group, an ethylaminomethyl group, and a diethylaminomethyl group. The aminoalkyl group may have a double bond between C—N or C—C.

A preferred example of the amine compound b2 is one in which all of R ³ , R ⁴ and R ⁵ are alkyl groups. For example, it is preferred that all of R ³ , R ⁴ and R ⁵ are alkyl groups having 1 to 8 carbon atoms (preferably 1 to 3, typically 1 or 2). Specific examples of such amine compound b2 include trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tricyclohexylamine, N, N-dimethylethylamine, N , N-diethylmethylamine, N, N-dimethylbutylamine, N, N-diethylbutylamine, N, N-dimethylpentylamine, N, N-diethylpentylamine, N, N-dimethylhexylamine, N, N-di Examples include ethylhexylamine, N, N-dimethylcyclohexylamine, N, N-diethylcyclohexylamine, N, N-diisopropylethylamine; and the like. Of these, trimethylamine, triethylamine, and tripropylamine are preferable, and triethylamine is particularly preferable.

As another example of the amine compound b2, R ³ and R ⁵ are alkyl groups having 1 to 8 carbon atoms (preferably 1 to 3, typically 1 or 2), and R ⁴ is hydrogen. What is an atom is mentioned. Specific examples of such amine compound b2 include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dicyclohexylamine, N-ethylmethylamine, N-methylpropylamine, N -Ethylpropylamine, N-butylmethylamine, N-butylethylamine, N-methylpentylamine, N-ethylpentylamine, N-hexylmethylamine, N-ethylhexylamine;

As another example of the amine compound b2, R ³ is an alkyl group having 1 to 8 carbon atoms (preferably 1 to 3, typically 1 or 2), and R ⁴ is a hydrogen atom or a carbon atom number. 1 to 8 (preferably 1 to 3, typically 1 or 2) alkyl group, and R ⁵ has 1 to 6 carbon atoms (preferably 1 to 3, typically 1 or 2). And those having an aminoalkyl group. Specific examples of such amine compound b2 include N, N′-dimethylethylenediamine, trimethylethylenediamine, tetramethylethylenediamine, N, N′-diethylethylenediamine, triethylethylenediamine, tetraethylethylenediamine, N-ethyl-N′-methylethylenediamine, N, N-dimethyl-N'-ethylethylenediamine, N, N-diethyl-N'-methylethylenediamine, N, N-diethyl-N'N'-dimethylethylenediamine, N, N'-dimethyltrimethylenediamine, trimethyltri Methylenediamine, tetramethyltrimethylenediamine, N, N′-diethyltrimethylenediamine, triethyltrimethylenediamine, tetraethyltrimethylenediamine, N-ethyl-N′-methyltrimethylenediamine; Etc. are exemplified.

As another example of the amine compound b2, R ³ and R ⁵ are an alkyl group or an aminoalkyl group having 1 to 6 carbon atoms (preferably 1 to 3, typically 1 or 2), and Examples thereof include nitrogen-containing heterocyclic compounds in which R ³ and R ⁵ are bonded to each other to form a cyclic structure. Specific examples of such amine compound b2 include imidazole, 1-methylimidazole, 4-methylimidazole, 1,2-dimethylimidazole, 2,4-dimethylimidazole, 1-ethylimidazole, 4-ethylimidazole, 1,2 -Diethylimidazole, 2-ethyl-4-methylimidazole, 1-propylimidazole, 4-propylimidazole, 1-butylimidazole, 4-butylimidazole, pyrazole, imidazoline, piperazine, 1-methylpiperazine, 2-methylpiperazine, 1 -Ethylpiperazine, 2-ethylpiperazine, 1-ethyl-4-methylpiperazine, 1- (2-dimethylaminoethyl) piperazine, 1- (2-dimethylaminoethyl) -4-methylpiperazine, 1-propylpiperazine, 2 - B pills piperazine, 1-butyl piperazine, 4-butyl piperazine; and the like. Of these, imidazole, 1-methylimidazole, 4-methylimidazole, 1-ethylimidazole, 4-ethylimidazole are preferable, and imidazole is particularly preferable.

(Amine compound B3)
Another preferred example of the roll-off compound B disclosed herein is an amine compound B3 containing an ether bond in the molecule. The series of amino groups in the amine compound B3 is not particularly limited, but preferably has at least one primary amino group. The total number of amino groups in the amine compound B3 can be, for example, 1 to 12, typically 1 to 10. The total number of amino groups in the amine compound B3 may be, for example, 1 to 8, and typically 1 to 4. The number of ether bonds in the amine compound B3 is, for example, 1 to 10, and typically 1 to 8. The number of ether bonds in the amine compound B3 may be, for example, 1 to 6, and typically 1 to 4.

An example of the amine compound B3 that is particularly preferable in the technology disclosed herein is an amine compound b3 represented by the following general formula (b3).
R ⁶ —N (R ⁷ ) — (CH ₂ ) _n —O—R ⁸ (b3)
(Wherein R ⁶ and R ⁷ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkyl group having an ether bond, and an aminoalkyl group. R ⁶ and R ⁷ are bonded to each other to form a ring. N may be an integer of 1 to 15. (CH ₂ ) _n may have a branched chain, R ⁸ is an alkyl group, an alkyl group having an ether bond, an aminoalkyl Selected from the group consisting of a group, an aminoalkyl group having an ether bond, and an amino group.

In the amine compound b3, the substituents R ⁶ and R ⁷ on the nitrogen atom constituting the amino group can be a hydrogen atom, an alkyl group, an alkyl group having an ether bond, or an aminoalkyl group. The alkyl group, the alkyl group having an ether bond, and the aminoalkyl group may be linear, branched, or cyclic. The total number of carbon atoms in the alkyl group, the alkyl group having an ether bond, and the aminoalkyl group may be 1 to 15 (preferably 1 to 12, more preferably 1 to 10, more preferably 2 to 6). R ⁶ and R ⁷ may be the same or different. R ⁶ and R ⁷ may be bonded to each other to form a cyclic structure. When R ⁶ and R ⁷ are alkyl groups, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. An alkyl group having an ether bond refers to an alkyl group having at least one ether bond. When R ⁶ and R ⁷ are alkyl groups having an ether bond, examples thereof include a methoxymethyl group, a methoxyethyl group, and a 2-methoxyethoxymethyl group. When R ⁶ and R ⁷ are aminoalkyl groups, for example, aminomethyl group, aminoethyl group, aminopropyl group, aminobutyl group, methylaminoethyl group, dimethylaminoethyl group, 2- (2-aminoethylamino) ethyl Groups and the like. In the amine compound b3, n represents the number of repetitions of (CH ₂ ). n is an integer of 1 to 15, preferably 1 to 10, more preferably 1 to 8, and still more preferably 1 to 6 (eg, 1 to 4, typically 2 or 3). (CH ₂ ) _n may have a branched chain. R ⁸ may be an alkyl group, an alkyl group having an ether bond, an aminoalkyl group, an aminoalkyl group having an ether bond, or an amino group. The alkyl group, the alkyl group having an ether bond, the aminoalkyl group, and the aminoalkyl group having an ether bond may be linear, branched, or cyclic. The total number of carbon atoms in the alkyl group, the alkyl group having an ether bond, the aminoalkyl group and the aminoalkyl group having an ether bond is 1 to 10 (preferably 1 to 6, more preferably 1 to 4, more preferably 1 to 3). ). An aminoalkyl group having an ether bond refers to an aminoalkyl group having at least one ether bond. When R ⁸ is an aminoalkyl group having an ether bond, examples thereof include a 2-aminoethoxyethyl group, a 2-aminopropoxyethyl group, a 3-aminoethoxypropyl group, a 3-aminopropoxypropyl group, and the like.

A preferred example of the amine compound b3 is one in which both R ⁶ and R ⁷ are hydrogen atoms. For example, both R ⁶ and R ⁷ are hydrogen atoms, the number of repetitions (CH ₂ ) n is 1 to 6 (preferably 1 to 4, typically 1 to 3), and R ⁸ is Those which are aminoalkyl groups or aminoalkyl groups having an ether bond are preferred. Specific examples of such amine compound b3 include bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, ethylene glycol bis (2-aminoethyl) ether, and ethylene glycol bis. (3-aminopropyl) ether, 1,3-propanediol bis (2-aminoethyl) ether, 1,3-propanediol bis (3-aminopropyl) ether, 1,4-butanediol bis (2-aminoethyl) ) Ether, 1,4-butanediol bis (3-aminopropyl) ether, 1,5-pentanediol bis (2-aminoethyl) ether, 1,5-pentanediol bis (3-aminopropyl) ether, diethylene glycol bis (3-Aminopropyl) ether, 1,11-di Mino 3,6,9 trio key sound decane and the like. Of these, 1,4-butanediol bis (3-aminopropyl) ether is preferable.

As another example of the amine compound b3, for example, both R ⁶ and R ⁷ are alkyl groups having 1 to 4 carbon atoms, and the number n of (CH ₂ ) repeats is 1 to 6 (preferably 1 to 4). , Typically 1 to 3), and R ⁸ is preferably an aminoalkyl group or an aminoalkyl group having an ether bond. Specific examples of such amine compound b3 include bis (dimethylaminomethyl) ether, bis (2-dimethylaminoethyl) ether, bis (3-dimethylaminopropyl) ether, ethylene glycol bis (2-dimethylaminoethyl) ether. , Ethylene glycol bis (3-dimethylaminopropyl) ether, 1,3-propanediol bis (2-dimethylaminoethyl) ether, 1,3-propanediol bis (3-dimethylaminopropyl) ether, 1,4-butane Examples thereof include diol bis (2-dimethylaminoethyl) ether, 1,4-butanediol bis (3-dimethylaminopropyl) ether, bis (diethylaminomethyl) ether, bis (2-diethylaminoethyl) ether;

As another example of the amine compound b3, both of R ⁶ and R ⁷ are hydrogen atoms, and the number of repetitions (CH ₂ ) n is 1 to 6 (preferably 1 to 4, typically 1 to 3). And R ⁸ is an alkyl group having 1 to 6 (preferably 1 to 4, typically 1 to 3) carbon atoms. Specific examples of such amine compound b3 include 2-methoxyethylamine, 2-ethoxyethylamine, 2-propoxyethylamine, 2-butoxyethylamine, 2-pentyloxyethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3 -Propoxypropylamine, 3-butoxypropylamine, 3-pentyloxypropylamine; and the like.

Other examples of the amine compound b3 include those in which R ⁶ and R ⁷ are different from each other. For example, one of R ⁶ and R ⁷ is a hydrogen atom, the other is an alkyl group having 1 to 4 carbon atoms, and R ⁸ is an aminoalkyl group or an aminoalkyl group having an ether bond. preferable. Specific examples of such amine compound b3 include bis (methylaminomethyl) ether, bis (2-methylaminoethyl) ether, bis (3-methylaminopropyl) ether, ethylene glycol bis (2-methylaminoethyl) ether. , Ethylene glycol bis (3-methylaminopropyl) ether, 1,3-propanediol bis (2-methylaminoethyl) ether, 1,3-propanediol bis (3-methylaminopropyl) ether, 1,4-butane Examples include diol bis (2-methylaminoethyl) ether, 1,4-butanediol bis (3-methylaminopropyl) ether, bis (ethylaminomethyl) ether, bis (2-ethylaminoethyl) ether; .

As another example of the amine compound b3, one of R ⁶ and R ⁷ is a hydrogen atom, the other is an alkyl group having 1 to 4 carbon atoms, and the repeating number n of (CH ₂ ) is 1 to 1 6 (preferably 1 to 4, typically 1 to 3), and R ⁸ is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4, typically 1 to 3). Things. Specific examples of such amine compound b3 include N-methyl-2-methoxyethylamine, N-methyl-2-ethoxyethylamine, N-methyl-2-propoxyethylamine, N-methyl-2-butoxyethylamine, and N-methyl. -2-pentyloxyethylamine, N-methyl-2-hexyloxyethylamine, N-methyl-2-heptyloxyethylamine, N-methyl-2-octyloxyethylamine, N-methyl-3-ethoxypropylamine, N- Methyl-3-propoxypropylamine, N-methyl-3-butoxypropylamine, N-methyl-3-pentyloxypropylamine, N-methyl-3-hexyloxypropylamine, N-methyl-3-heptyloxypropyl And the like;

(Amine compound B4)
Another preferred example of the roll-off compound B disclosed herein is an amine compound B4 having a hydrocarbon group having 1 or 2 carbon atoms between two primary amino groups in the molecule. Specific examples of such amine compound B4 include methylenediamine, ethylenediamine, 1-methylethylenediamine, 1-ethylethylenediamine, 1-propylethylenediamine, 1,1-dimethylethylenediamine, 1,1-diethylethylenediamine, 1,2-dimethyl. Examples include ethylenediamine, 1-ethyl-1-methylethylenediamine, 1-ethyl-2-methylethylenediamine; and the like. Of these, ethylenediamine is preferred.

A suitable ratio of the molar concentration of the roll-up amine compound A and the roll-off compound B may vary depending on the type of the roll-up amine compound A, the type of the roll-off compound B, a combination thereof, and the like. The concentration ratios listed below are examples and are not limited to these concentration ratios. When the amine compound a2 is used as the roll-up amine compound A, the molar concentration ratio of the amine compound a2 and the roll-off compound B (amine compound a2: roll-off compound B) is 1:10 to 100: 1. preferable. The molar concentration ratio is more preferably 1: 5 to 50: 1, and further preferably 1: 1 to 10: 1. When the amine compound a4 is used as the roll-up amine compound A, the molar concentration ratio of the amine compound a4 and the roll-off compound B (amine compound a4: roll-off compound B) is 1:10 to 200: 1. preferable. The molar concentration value is more preferably 1: 5 to 100: 1, and further preferably 1: 1 to 50: 1. When the amine compound a5 is used as the roll-up amine compound A, the molar concentration ratio of the amine compound a5 and the roll-off compound B (amine compound a5: roll-off compound B) is 1: 500 to 5: 1. preferable. The molar concentration ratio is more preferably 1:50 to 2: 1, and further preferably 1:25 to 1: 2. When the amine compound a6 is used as the roll-up amine compound A, the molar concentration ratio of the amine compound a6 and the roll-off compound B (amine compound a6: roll-off compound B) is 1:10 to 100: 1. preferable. The molar concentration ratio is more preferably 1: 5 to 50: 1, still more preferably 1: 2 to 25: 1.

<Water>
The polishing composition disclosed herein typically contains water in addition to the ether bond-free amine compound. As water, ion exchange water (deionized water), pure water, ultrapure water, distilled water and the like can be preferably used. The water to be used preferably has, for example, a total content of transition metal ions of 100 ppb or less in order to avoid as much as possible the action of other components contained in the polishing composition. For example, the purity of water can be increased by operations such as removal of impurity ions with an ion exchange resin, removal of foreign matter with a filter, distillation, and the like.
The polishing composition disclosed herein may further contain an organic solvent (lower alcohol, lower ketone, etc.) that can be uniformly mixed with water, if necessary. Usually, 90% by volume or more of the solvent contained in the polishing composition is preferably water, and 95% by volume or more (typically 99 to 100% by volume) is more preferably water.

<Abrasive>
The polishing composition disclosed herein contains abrasive grains in addition to an ether bond-free amine compound and water. In the technology disclosed herein, the material and properties of the abrasive grains are not particularly limited, and can be appropriately selected according to the purpose of use or the mode of use of the polishing composition. Examples of the abrasive grains include inorganic particles, organic particles, and organic-inorganic composite particles. Specific examples of the inorganic particles include silica particles, alumina particles, cerium oxide particles, chromium oxide particles, titanium dioxide particles, zirconium oxide particles, magnesium oxide particles, manganese dioxide particles, zinc oxide particles, oxide particles such as bengara particles; Examples thereof include nitride particles such as silicon nitride particles and boron nitride particles; carbide particles such as silicon carbide particles and boron carbide particles; diamond particles; carbonates such as calcium carbonate and barium carbonate. Specific examples of the organic particles include polymethyl methacrylate (PMMA) particles and poly (meth) acrylic acid particles (here, (meth) acrylic acid is a generic term for acrylic acid and methacrylic acid). And polyacrylonitrile particles. Such abrasive grains can be used singly or in combination of two or more.

As the abrasive, inorganic particles are preferable, and particles made of metal or metalloid oxide are particularly preferable. As a suitable example of abrasive grains that can be used in the technique disclosed herein, silica particles can be mentioned. For example, when the technique disclosed herein is applied to a polishing composition that can be used for polishing a silicon wafer, it is particularly preferable to use silica particles as abrasive grains. The reason is that when the object to be polished is a silicon wafer, if silica particles consisting of the same elements and oxygen atoms as the object to be polished are used as abrasive grains, a metal or metalloid residue different from silicon is generated after polishing. This is because there is no possibility of contamination of the silicon wafer surface or deterioration of electrical characteristics as a silicon wafer due to diffusion of a metal or semimetal different from silicon into the object to be polished. Furthermore, since the hardness of silicon and silica is close, polishing can be performed without undue damage to the silicon wafer surface. A polishing composition containing only silica particles as an abrasive is exemplified as a preferred embodiment of the polishing composition from this viewpoint. Silica has a property that it can be easily obtained in high purity. This is also cited as the reason why silica particles are preferable as the abrasive grains. Specific examples of the silica particles include colloidal silica, fumed silica, precipitated silica and the like. Colloidal silica and fumed silica are preferable as silica particles from the viewpoint that scratches are hardly generated on the surface of the object to be polished and a surface having a lower haze can be realized. Of these, colloidal silica is preferred. For example, colloidal silica can be preferably employed as abrasive grains of a polishing composition used for polishing a silicon wafer (at least one of preliminary polishing and final polishing, preferably preliminary polishing).

The true specific gravity of silica constituting the silica particles is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.7 or more. By increasing the true specific gravity of silica, the polishing rate (amount for removing the surface of the object to be polished per unit time) can be improved when polishing a silicon wafer. From the viewpoint of reducing scratches generated on the surface of the object to be polished (surface to be polished), silica particles having a true specific gravity of 2.2 or less are preferable. As the true specific gravity of silica, a measured value by a liquid substitution method using ethanol as a substitution liquid can be adopted.

In the technique disclosed herein, the abrasive grains contained in the polishing composition may be in the form of primary particles or may be in the form of secondary particles in which a plurality of primary particles are associated. Further, abrasive grains in the form of primary particles and abrasive grains in the form of secondary particles may be mixed. In a preferred embodiment, at least a part of the abrasive grains is contained in the polishing composition in the form of secondary particles.

There is no particular average primary particle diameter D _P1 of the abrasive grains limited, from the viewpoint of polishing rate, preferably 5nm or more, more preferably 10nm or more, particularly preferably 20nm or more. From the viewpoint of obtaining a higher polishing effect, the average primary particle diameter _{D P1} is preferably at least 25 nm, further preferably not less than 30 nm. Abrasive grains having an average primary particle diameter _DP1 of 40 nm or more may be used. Further, from the viewpoint of storage stability (for example, dispersion stability), the average primary particle diameter of the abrasive grains is preferably 100 nm or less, more preferably 80 nm or less, still more preferably 70 nm or less, for example 60 nm or less.
In the technology disclosed herein, the average primary particle diameter D _P1 of the abrasive grains is, for example, from the specific surface area (BET value) measured by the BET method, D _P1 (nm) = 6000 / (true density (g / Cm ³ ) × BET value (m ² / g)). For example, in the case of silica particles, it can be calculated by the formula of D _P1 (nm) = 2727 / BET value (nm). The specific surface area can be measured using, for example, a surface area measuring device manufactured by Micromeritex Corporation, a trade name “Flow Sorb II 2300”.

But not limited abrasive grains having an average secondary particle diameter D _P2 in particular, from the viewpoint of polishing rate is preferably 15nm or more, and more preferably 25nm or more. From the viewpoint of obtaining a higher polishing effect, the average secondary particle diameter _DP2 is preferably 40 nm or more, and more preferably 50 nm or more. From the viewpoint of storage stability (e.g., dispersion stability), average secondary particle diameter _{D P2} of the abrasive grains is appropriately 200nm or less, preferably 150nm or less, more preferably 100nm or less. Average abrasive grain of the secondary particle diameter D _P2, for example, can be measured by a dynamic light scattering method using a Nikkiso Co. Model "UPA-UT151".

The average secondary particle diameter D _P2 of the abrasive grains is generally equal to or greater than the average primary particle diameter D _P1 of the abrasive grains (D _P2 / D _P1 ≧ 1) and is typically larger than D _P1 (D _P2 / D _P1 > 1). Although not particularly limited, in view of the polishing effect and the surface smoothness after polishing, the D _P2 / D _P1 of the abrasive grains is usually suitably in the range of 1.05 to 3, and The range of 1 to 2.5 is preferable, and the range of 1.2 to 2.3 (for example, more than 1.3 and 2.2 or less) is more preferable.

The shape (outer shape) of the abrasive grains may be spherical or non-spherical. Specific examples of non-spherical abrasive grains include a peanut shape (that is, a peanut shell shape), a bowl shape, a confetti shape, and a rugby ball shape.

Although not particularly limited, the average value (average aspect ratio) of the major axis / minor axis ratio of the primary particles of the abrasive grains is preferably 1.05 or more, more preferably 1.1 or more. Higher polishing rates can be achieved by increasing the average aspect ratio of the abrasive grains. The average aspect ratio of the abrasive grains is preferably 3.0 or less, more preferably 2.0 or less, and still more preferably 1.5 or less, from the viewpoint of reducing scratches.

The shape (outer shape) and average aspect ratio of the abrasive grains can be grasped by, for example, observation with an electron microscope. As a specific procedure for grasping the average aspect ratio, for example, a predetermined number (for example, 200) of abrasive particles capable of recognizing the shape of independent particles using a scanning electron microscope (SEM) is used. Draw the smallest rectangle that circumscribes the image. For the rectangle drawn for each particle image, the value obtained by dividing the length of the long side (major axis value) by the length of the short side (minor axis value) is the major axis / minor axis ratio (aspect ratio). ). An average aspect ratio can be obtained by arithmetically averaging the aspect ratios of the predetermined number of particles.

The content of abrasive grains in the polishing composition is typically 0.01 wt% or more, preferably 0.05 wt% or more, more preferably 0.1 wt% or more, More preferably, it is 0.15 weight% or more. Higher polishing rates can be achieved by increasing the abrasive content. Further, from the viewpoint of dispersion stability of the polishing composition, cost reduction, etc., the content is usually suitably 2% by weight or less, preferably 1.5% by weight or less, more preferably 1% by weight. Hereinafter, it is more preferably less than 1% by weight, particularly preferably 0.5% by weight or less.

<Other ingredients>
The polishing composition disclosed herein is a water-soluble polymer, surfactant, buffering agent, chelating agent, organic acid, organic acid salt, inorganic acid, inorganic acid as long as the effects of the present invention are not significantly hindered. Further containing known additives as needed, which can be used for polishing compositions (typically, polishing compositions used in the polishing process of silicon wafers) such as salts, preservatives, and fungicides. May be.

As an example of the chelating agent, it functions to suppress contamination of an object to be polished by metal impurities by forming and capturing complex ions with metal impurities that can be contained in the polishing composition. A chelating agent can be used individually by 1 type or in combination of 2 or more types.
Examples of chelating agents include aminocarboxylic acid chelating agents and organic phosphonic acid chelating agents. Examples of aminocarboxylic acid chelating agents include ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid sodium, nitrilotriacetic acid, nitrilotriacetic acid sodium, nitrilotriacetic acid ammonium, hydroxyethylethylenediaminetriacetic acid, hydroxyethylethylenediamine sodium triacetate, diethylenetriaminepentaacetic acid Diethylenetriamine sodium pentaacetate, triethylenetetramine hexaacetic acid and sodium triethylenetetramine hexaacetate. Examples of organic phosphonic acid chelating agents include 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic). Acid), ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid Ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid and α-methylphospho Nosuccinic acid is included. Of these, organic phosphonic acid-based chelating agents are more preferable, and aminotri (methylenephosphonic acid), ethylenediaminetetrakis (methylenephosphonic acid), and diethylenetriaminepenta (methylenephosphonic acid) are particularly preferable.

Examples of water-soluble polymers include cellulose derivatives, starch derivatives, polymers containing oxyalkylene units, polymers containing nitrogen atoms, vinyl alcohol polymers, and the like. Specific examples include hydroxyethyl cellulose, pullulan, random copolymer or block copolymer of ethylene oxide and propylene oxide, polyvinyl alcohol, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyisoamylene sulfonic acid. Polystyrene sulfonate, polyacrylate, polyvinyl acetate, polyethylene glycol, polyvinyl pyrrolidone, polyacryloylmorpholine, polyacrylamide and the like. A water-soluble polymer can be used singly or in combination of two or more. The polishing composition disclosed herein may be a composition that does not substantially contain the water-soluble polymer.

Examples of organic acids include fatty acids such as formic acid, acetic acid and propionic acid, aromatic carboxylic acids such as benzoic acid and phthalic acid, citric acid, oxalic acid, tartaric acid, malic acid, maleic acid, fumaric acid, succinic acid, organic Examples include sulfonic acid and organic phosphonic acid. Examples of organic acid salts include alkali metal salts (sodium salts, potassium salts, etc.) and ammonium salts of organic acids. Examples of inorganic acids include sulfuric acid, nitric acid, hydrochloric acid, carbonic acid and the like. Examples of inorganic acid salts include alkali metal salts (sodium salts, potassium salts, etc.) and ammonium salts of inorganic acids. An organic acid and its salt, and an inorganic acid and its salt can be used individually by 1 type or in combination of 2 or more types.
Examples of antiseptics and fungicides include isothiazoline compounds, paraoxybenzoates, phenoxyethanol and the like.

It is preferable that the polishing composition disclosed here contains substantially no oxidizing agent. When an oxidizing agent is contained in the polishing composition, the composition is supplied to an object to be polished (for example, a silicon wafer), whereby the surface of the object to be polished is oxidized to produce an oxide film. This is because the required polishing time becomes long. Specific examples of the oxidizing agent herein include hydrogen peroxide (H ₂ O ₂ ), sodium persulfate, ammonium persulfate, sodium dichloroisocyanurate, and the like. In addition, that polishing composition does not contain an oxidizing agent substantially means not containing an oxidizing agent at least intentionally. Therefore, a trace amount (for example, the molar concentration of the oxidant in the polishing composition is 0.0005 mol / L or less, preferably 0.0001 mol or less, more preferably 0.00001 mol / A polishing composition inevitably containing an oxidizing agent of L or less, particularly preferably 0.000001 mol / L or less) is included in the concept of a polishing composition substantially containing no oxidizing agent. Can be done.

The pH of the polishing composition is preferably 8.0 or more (for example, 8.5 or more), more preferably 9.0 or more, and further preferably 9.5 or more (for example, 10.0 or more). When the pH of the polishing composition increases, the polishing rate tends to improve. The upper limit of the pH of the polishing composition is not particularly limited, but is preferably 12.0 or less (for example, 11.8 or less), and more preferably 11.5 or less. As a result, the object to be polished can be better polished. The pH can be preferably applied to a polishing composition used for polishing a silicon wafer.

<Preparation of polishing composition>
The manufacturing method of polishing composition disclosed here is not specifically limited. For example, each component contained in the polishing composition may be mixed using a well-known mixing device such as a blade-type stirrer, an ultrasonic disperser, or a homomixer. The aspect which mixes these components is not specifically limited, For example, all the components may be mixed at once and may be mixed in the order set suitably.

The polishing composition disclosed herein may be a one-part type or a multi-part type including a two-part type. For example, the liquid A containing a part of the constituents of the polishing composition (typically, components other than the aqueous solvent) and the liquid B containing the remaining components are mixed to form a polishing object. You may be comprised so that it may be used for grinding | polishing.

<Polishing liquid>
The polishing composition disclosed herein is supplied to a polishing object typically held in a processing carrier made of epoxy glass resin in the form of a polishing liquid containing the polishing composition, and the polishing object Used for polishing. The polishing liquid may be prepared, for example, by diluting (typically diluting with water) any of the polishing compositions disclosed herein. Or you may use this polishing composition as polishing liquid as it is. That is, the concept of the polishing composition in the technology disclosed herein is used as a polishing liquid diluted with a polishing liquid (working slurry) that is supplied to a polishing object and used for polishing the polishing object. Both concentrated liquid (polishing liquid stock solution) are included. Another example of the polishing liquid containing the polishing composition disclosed herein is a polishing liquid obtained by adjusting the pH of the composition.

The molar concentration of the roll-up amine compound A in the polishing liquid disclosed herein is not particularly limited, but is typically 0.00005 mol / L or more, preferably 0.0001 mol / L or more, and 0 More preferably, it is 0.00000 mol / L or more, and further more preferably 0.0002 mol / L or more. In general, the molar concentration is suitably 1 mol / L or less, preferably 0.5 mol / L or less, more preferably 0.3 mol / L or less, and still more preferably 0.1 mol / L. Hereinafter, for example, it is 0.05 mol / L or less.

The molar concentration of the roll-off compound B in the polishing liquid disclosed herein is not particularly limited, but is typically 0.00005 mol / L or more, preferably 0.0001 mol / L or more, and It is more preferably 001 mol / L or more, and further preferably 0.002 mol / L or more. In general, the molar concentration is suitably 1 mol / L or less, preferably 0.5 mol / L or less, more preferably 0.3 mol / L or less, and still more preferably 0.1 mol / L. Hereinafter, for example, it is 0.05 mol / L or less.

The content of abrasive grains in the polishing liquid disclosed herein is not particularly limited, but is typically 0.01% by weight or more, preferably 0.03% by weight or more, and 0.05% by weight or more. It is more preferable that it is 0.1% by weight or more. Higher polishing rates can be achieved by increasing the abrasive content. From the viewpoint of dispersion stability of the polishing composition, the content is usually suitably 15% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, and still more preferably. 3% by weight or less, for example 1.2% by weight or less.

The pH of the polishing liquid is preferably 8.0 or more (for example, 8.5 or more), more preferably 9.0 or more, still more preferably 9.5 or more, and particularly preferably 10.0 or more (for example, 10. 5 or more). When the pH of the polishing liquid increases, the polishing rate tends to improve. The upper limit of the pH of the polishing liquid is not particularly limited, but is preferably 12.0 or less (for example, 11.8 or less), and more preferably 11.5 or less. As a result, the object to be polished can be better polished. The pH can be preferably applied to a polishing liquid used for polishing a silicon wafer.

<Concentrate>
The polishing composition disclosed herein may be in a concentrated form (that is, in the form of a polishing liquid concentrate) before being supplied to the object to be polished. The polishing composition in such a concentrated form is advantageous from the viewpoints of convenience, cost reduction, etc. during production, distribution, storage and the like. The concentration rate can be, for example, about 2 to 60 times in terms of volume.

Thus, the polishing composition in the form of a concentrated liquid can be used in such a manner that a polishing liquid is prepared by diluting at a desired timing and the polishing liquid is supplied to an object to be polished. The dilution can be typically performed by adding and mixing the above-mentioned aqueous solvent to the concentrated solution. In addition, when the aqueous solvent is a mixed solvent, only a part of the components of the aqueous solvent may be added for dilution, and a mixture containing these components in a different ratio from the aqueous solvent. A solvent may be added for dilution. In addition, as will be described later, in a multi-component polishing composition, a part of them may be diluted and then mixed with another agent to prepare a polishing liquid, or a plurality of agents may be mixed. Later, the mixture may be diluted to prepare a polishing liquid.

The content of abrasive grains in the concentrated liquid can be, for example, 50% by weight or less. From the viewpoint of the stability of the polishing composition (for example, dispersion stability of abrasive grains) and filterability, the content is usually preferably 45% by weight or less, more preferably 40% by weight or less. . In a preferred embodiment, the abrasive content may be 30% by weight or less, or 20% by weight or less (eg, 15% by weight or less). From the viewpoint of convenience, cost reduction, etc. during production, distribution, storage, etc., the content of the abrasive grains can be, for example, 1.0% by weight or more, preferably 3.0% by weight or more, More preferably, it is 5.0 weight% or more, More preferably, it is 7.0 weight% or more.

<Application>
The polishing composition disclosed herein can be applied to polishing a polishing object having various materials and shapes. The material of the object to be polished is, for example, a metal or semimetal such as silicon, aluminum, nickel, tungsten, copper, tantalum, titanium, stainless steel, germanium, or an alloy thereof; quartz glass, aluminosilicate glass, glassy carbon, etc. A glassy substance; ceramic material such as alumina, silica, sapphire, silicon nitride, tantalum nitride, titanium carbide; compound semiconductor substrate material such as silicon carbide, gallium nitride, gallium arsenide; resin material such as polyimide resin; obtain. Of these, a polishing object composed of a plurality of materials may be used. Especially, it is suitable for grinding | polishing of the grinding | polishing target object provided with the surface which consists of silicon | silicone. The technique disclosed here is, for example, a polishing composition containing silica particles as abrasive grains (typically, a polishing composition containing only silica particles as abrasive grains), and the object to be polished is silicon. It can be particularly preferably applied to a certain polishing composition.
The shape of the object to be polished is not particularly limited. The polishing composition disclosed herein can be preferably applied to, for example, a polishing object having a flat surface such as a plate shape or a polyhedron shape, or polishing of an end portion of the polishing object (for example, polishing of a wafer edge).

<Polishing method>
The polishing composition disclosed herein can be preferably used as a polishing composition for polishing silicon (for example, a single crystal or polycrystalline silicon wafer). Hereinafter, a preferred embodiment of a method for polishing a polishing object using the polishing composition disclosed herein will be described.
That is, a polishing liquid (slurry) containing any of the polishing compositions disclosed herein is prepared. Preparing the polishing liquid may include preparing a polishing liquid by adding operations such as concentration adjustment (for example, dilution) to the polishing composition. Or you may use the said polishing composition as polishing liquid as it is. Further, in the case of a multi-drug type polishing composition, to prepare the polishing liquid, mixing those agents, diluting one or more agents before the mixing, and after the mixing Diluting the mixture, etc. can be included.

Next, the polishing liquid is supplied to the object to be polished and polished by a conventional method. For example, when performing a primary polishing process (typically a double-side polishing process) of an object to be polished, the object to be polished that has undergone the lapping process is set in a general polishing apparatus, and the above-mentioned is passed through a polishing pad of the polishing apparatus A polishing liquid is supplied to the surface of the object to be polished (surface to be polished). Typically, while supplying the polishing liquid continuously, the polishing pad is pressed against the surface of the object to be polished, and both are relatively moved (for example, rotated). Thereafter, if necessary, a further secondary polishing step (typically a single-side polishing step) is performed, and finally final polishing is performed to complete polishing of the object to be polished.
In addition, the polishing pad used in the polishing process using the polishing composition disclosed herein is not particularly limited. For example, any of non-woven fabric type, suede type, polyurethane type, those containing abrasive grains, and those not containing abrasive grains may be used.

According to this specification, there is provided a method for producing a polished article comprising a step of polishing an object to be polished using the polishing composition disclosed herein. The method for producing a polished product disclosed herein may further include a step of subjecting a polishing object that has undergone a polishing step using the polishing composition to a final polishing. Here, final polishing refers to the final polishing step in the manufacturing process of the object (that is, a step in which no further polishing is performed after that step). The final polishing step may be performed using the polishing composition disclosed herein, or may be performed using another polishing composition.
In a preferred embodiment, the polishing step using the polishing composition is a polishing step upstream of final polishing. Especially, it can apply preferably to the preliminary | backup polishing which finished the lapping process. For example, a double-side polishing process (typically a primary polishing process) that has undergone a lapping process, or an initial single-side polishing process (typically an initial secondary polishing process) that is performed on a substrate that has undergone the double-side polishing process. Can be preferably used. In the double-side polishing step and the first single-side polishing step, a required polishing rate is larger than final polishing. Therefore, the polishing composition disclosed herein is suitable as a polishing composition used for polishing a polishing object in at least one (preferably both) of the double-side polishing step and the first single-side polishing step.

Note that the polishing composition may be used in a disposable form (so-called “running”) once used for polishing, or may be repeatedly used after circulation. As an example of a method of circulating and using the polishing composition, there is a method of collecting a used polishing composition discharged from the polishing apparatus in a tank and supplying the recovered polishing composition to the polishing apparatus again. . When the polishing composition is used in a circulating manner, the environmental load can be reduced by reducing the amount of the used polishing composition to be treated as a waste liquid, as compared with the case where the polishing composition is used by pouring. Moreover, cost can be suppressed by reducing the usage-amount of polishing composition. When the polishing composition disclosed herein is used in a circulating manner, a new component, a component reduced by use, or a component desired to increase may be added to the polishing composition in use at any timing. Good.

Hereinafter, some examples relating to the present invention will be described. However, the present invention is not intended to be limited to the examples shown in the examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

≪Test A≫
<Preparation of polishing composition>
Example 1A
A polishing composition was prepared by mixing abrasive grains, an amine bond-free amine compound and deionized water. Silica particles (average primary particle size 50 nm) were used as the abrasive grains. Triethylenetetramine (hereinafter referred to as “TETA”) was used as the amine compound not containing an ether bond. The abrasive grain content in the polishing composition was 0.5%, and the TETA content was such that the polishing composition had a pH of 11.2 (less than 1%).

(Example 2A)
Instead of TETA, N-ethylethylenediamine (hereinafter referred to as “NEDA”) was used. The NEDA content in the polishing composition was such that the pH of the polishing composition was 11.2 (less than 1%). The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Example 3A)
Instead of TETA, N- (2-aminoethyl) piperazine (hereinafter referred to as “AEP”) was used. The content of AEP in the polishing composition was such that the pH of the polishing composition was 11.2 (less than 1%). The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Example 4A)
Instead of TETA, 1,6-diaminohexane (hereinafter referred to as “DAH”) was used. The content of DAH in the polishing composition was such that the pH of the polishing composition was 11.2 (less than 1%). The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Example 5A)
Instead of TETA, 2- (2-aminoethylamino) ethanol (hereinafter referred to as “AEAE”) was used. The content of AEAE in the polishing composition was such that the pH of the polishing composition was 11.2 (less than 1%). The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 1A)
Instead of TETA, potassium hydroxide (hereinafter referred to as “KOH”) was used. The content of KOH in the polishing composition was such an amount that the pH of the polishing composition was 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 2A)
Tetraethylammonium hydroxide (hereinafter referred to as “TEAH”) was used in place of TETA. The content of TEAH in the polishing composition was such that the polishing composition had a pH of 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 3A)
Instead of TETA, triethylamine (hereinafter referred to as “TEA”) was used. The TEA content in the polishing composition was such that the polishing composition had a pH of 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 4A)
Instead of TETA, 3-ethoxypropylamine (hereinafter referred to as “EPA”) was used. The content of EPA in the polishing composition was such that the pH of the polishing composition was 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 5A)
Instead of TETA, ethylenediamine (hereinafter referred to as “en”) was used. The en content in the polishing composition was such that the pH of the polishing composition was 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

(Comparative Example 6A)
Instead of TETA, 1,4-butanediol bis (3-aminopropyl) ether (hereinafter referred to as “BBAE”) was used. The content of BBAE in the polishing composition was such that the pH of the polishing composition was 11.2. The other points were the same as Example 1A, and a polishing composition according to this example was prepared.

<Evaluation of polishing rate of silicon>
The polishing composition according to each example was directly used as a polishing liquid, and a silicon wafer was subjected to a polishing test to evaluate the silicon polishing rate and the edge roll-off amount. As a test piece, a 6 cm × 6 cm silicon wafer (conduction type: P type, crystal orientation: <100>) was used. This specimen was polished under the following conditions. The polishing rate was calculated according to the following calculation formulas (a) and (b). The results are shown in the corresponding column of Table 1.
(A) Polishing allowance [cm] = difference in weight of silicon wafer before and after polishing [g] / silicon density [g / cm ³ ] (= 2.33 g / cm ³ ) / polishing target area [cm ² ] ( = 36cm ² )
(B) Polishing rate [nm / min] = polishing allowance [μm] × 10 ³ / polishing time [min]
[Polishing conditions]
Polishing machine: Desktop polishing machine manufactured by Nippon Engis Co., Ltd. Model “EJ-380IN”
Polishing pad: Product name “MH S-15A” manufactured by Nittahs
Polishing pressure: 16.8 kPa
Surface plate rotation speed: 50 rotations / minute Head rotation speed: 40 rotations / minute Polishing allowance: 8 μm
Polishing liquid supply rate: 100 mL / min
Polishing liquid temperature: 25 ° C

<Edge roll-off amount evaluation>
The edge roll-off amount at the outer peripheral portion of the polished silicon wafer was evaluated. The evaluation of the edge roll-off amount was performed by measuring the shape displacement amount of the silicon wafer surface by using “New View 5032” manufactured by Zygo (USA). Specifically, a straight line (reference straight line) that approximates the amount of shape displacement in this area is defined as a relatively flat area at a position of 2.0 mm to 4.0 mm from the outer peripheral edge of the silicon wafer toward the center. Is subtracted using the method of least squares. Next, using the point on the reference straight line as a reference point, the difference between the silicon wafer shape displacement amount at the outer peripheral end position and the reference point was measured, and this was used as the roll-off value of the silicon wafer. If the outer peripheral edge of the silicon wafer has a sag shape, the roll-off value is negative. On the other hand, if the silicon wafer is bounced up, the roll-off value is positive. The obtained results are shown in the “roll-off value (nm)” column of Table 1.

As shown in Table 1, according to the polishing compositions of Examples 1A to 5A using an ether bond-free amine compound that satisfies any of the conditions (1) and (2), Comparative Examples 1A to 4A, Compared with 6A, the polishing rate of silicon could be remarkably improved. In addition, the polishing compositions of Examples 1A to 5A were more effective in reducing the edge roll-off amount because the sagging of the end face of the silicon wafer was suppressed as compared with Comparative Examples 1A to 6A. From this result, it was confirmed that by using the amine compound not containing an ether bond, a high polishing rate and a reduction in the edge roll-off amount can be achieved at a high level while suppressing the content of abrasive grains low.

≪Test B≫
<Rolloff amount _{X A} and roll off quantity _{X B} Evaluation>
The roll-off amount X _B of the roll-off amount X _A and roll-off compound B rollup amine compound A was evaluated as follows. First, the compounds described in Table 2 and Table 3 were each dissolved in water and adjusted to pH 11.0. Then, polishing composition was prepared so that it might become a silica abrasive grain density | concentration of 0.5 mass%. A silicon wafer was polished under the following standard polishing test conditions using the polishing composition. The reference point is a relatively flat area from 2.0 mm to 4.0 mm from the outer peripheral edge to the center of the silicon wafer, and the difference between the silicon wafer shape displacement at the 0.5 mm position from the outer peripheral edge and the reference point It was calculated as a roll-off amount X _A and roll off quantity X _B. The results are shown in Tables 2 and 3. In Table 2, “NEDA” is N-ethylethylenediamine, “AEAE” is 2- (2-aminoethylamino) ethanol, “TETA” is triethylenetetramine, and “AEP” is N- (2-aminoethyl) piperazine and “DETA” is diethylenetriamine. In Table 3, “KOH” is potassium hydroxide, “TMAH” is tetramethylammonium hydroxide, “en” is ethylenediamine, “TEA” is triethylamine, “DEA” is diethylamine, “M-DACy” is 1,2-diaminocyclohexane, “EPA” is 3-ethoxypropylamine, “AMB” is 2-amino-1-methoxybutane, and “BBAE” is 1,4- Butanediol bis (3-aminopropyl) ether.
[Standard polishing test conditions]
Polishing machine: Desktop polishing machine manufactured by Nippon Engis Co., Ltd. Model “EJ-380IN”
Polishing pad: Product name “MH S-15A” manufactured by Nittahs
Polishing pressure: 16.8 kPa
Surface plate rotation speed: 50 rotations / minute Head rotation speed: 40 rotations / minute Polishing allowance: 8 μm
Polishing liquid supply rate: 100 mL / min
Polishing liquid temperature: 25 ° C

<Preparation of polishing composition>
(Example 1B)
Abrasive grains, a roll-up amine compound A, a roll-off compound B, and deionized water were mixed to prepare a polishing composition. Silica particles (average primary particle size 50 nm) were used as the abrasive grains. As the roll-up amine compound A, N-ethylethylenediamine (hereinafter referred to as “NEDA”) was used. As the roll-off compound B, potassium hydroxide (hereinafter referred to as “KOH”) was used. The abrasive content in the polishing composition was 0.5%, the molar concentration of NEDA was 0.01 mol / L, and the molar concentration of KOH was 0.002 mol / L. The pH of the polishing composition was adjusted to 11.0.

(Example 2B)
Instead of NEDA, 2- (2-aminoethylamino) ethanol (hereinafter referred to as “AEAE”) was used. The molar concentration of AEAE in the polishing composition was 0.02 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Example 3B)
Instead of NEDA, triethylenetetramine (hereinafter referred to as “TETA”) was used. The molar concentration of TETA in the polishing composition was 0.0003 mol / L, and the molar concentration of KOH was 0.004 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Example 4B)
Instead of NEDA, N- (2-aminoethyl) piperazine (hereinafter referred to as “AEP”) was used. Instead of KOH, tetramethylammonium hydroxide (hereinafter referred to as “TMAH”) was used. The molar concentration of AEP in the polishing composition was 0.0021 mol / L, and the molar concentration of TMAH was 0.006 mol / L. The content of abrasive grains in the polishing composition was 1.1%. As other components, 0.035% potassium carbonate (K ₂ CO ₃ ) and 0.0025% ethylenediaminetetrakis (methylenephosphonic acid) hydrate were added. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Example 5B)
AEAE was used instead of NEDA. TMAH was used instead of KOH. The molar concentration of AEAE in the polishing composition was 0.0026 mol / L, and the molar concentration of TMAH was 0.006 mol / L. The content of abrasive grains in the polishing composition was 1.1%. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Example 6B)
TETA was used instead of NEDA. Instead of KOH, ethylenediamine (hereinafter referred to as “en”) was used. The molar concentration of TETA in the polishing composition was 0.0013 mol / L, and the molar concentration of en was 0.013 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Example 7B)
TETA was used instead of NEDA. Instead of KOH, triethylamine (hereinafter referred to as “TEA”) was used. The molar concentration of TETA in the polishing composition was 0.003 mol / L, and the molar concentration of TEA was 0.003 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Comparative Example 1B)
NEDA was not used. The molar concentration of KOH in the polishing composition was 0.004 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Reference Example 2B)
KOH was not used. The molar concentration of NEDA in the polishing composition was 0.018 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Reference Example 3B)
AEAE was used instead of NEDA, which did not use KOH. The molar concentration of AEAE in the polishing composition was 0.035 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Reference Example 4B)
TETA was used instead of NEDA, which did not use KOH. The molar concentration of TETA in the polishing composition was 0.025 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Comparative Example 5B)
NEDA was not used. In addition to KOH, TMAH was used. The molar concentration of KOH in the polishing composition was 0.0007 mol / L, and the molar concentration of TMAH was 0.006 mol / L. The content of abrasive grains in the polishing composition was 1.1%. As other components, 0.035% potassium carbonate (K ₂ CO ₃ ) and 0.0025% ethylenediaminetetrakis (methylenephosphonic acid) hydrate were added. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Comparative Example 6B)
NEDA was not used. Instead of KOH, TMAH and imidazole (hereinafter referred to as “imd”) were used. In the polishing composition, the molar concentration of TMAH was 0.006 mol / L, and the molar concentration of imd was 0.004 mol / L. The content of abrasive grains in the polishing composition was 1.1%. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

(Comparative Example 7B)
NEDA was not used. Instead of KOH, en and TEA were used. The molar concentration of en in the polishing composition was 0.0084 mol / L, and the molar concentration of TEA was 0.0014 mol / L. Otherwise, the polishing composition according to this example was prepared in the same manner as in Example 1B.

Table 4 summarizes the types and molar concentrations of the roll-up amine compound A and the types and molar concentrations of the roll-off compound B used for the polishing composition according to each example.

<Evaluation of polishing rate of silicon>
The polishing composition according to each example was directly used as a polishing liquid, and a silicon wafer was subjected to a polishing test to evaluate the silicon polishing rate and the edge roll-off amount. As a test piece, a 6 cm × 6 cm silicon wafer (conduction type: P type, crystal orientation: <100>) was used. This specimen was polished under the following conditions. The polishing rate was calculated according to the following calculation formulas (a) and (b). The results are shown in the corresponding column of Table 4.
(A) Polishing allowance [cm] = difference in weight of silicon wafer before and after polishing [g] / silicon density [g / cm ³ ] (= 2.33 g / cm ³ ) / polishing target area [cm ² ] ( = 36cm ² )
(B) Polishing rate [nm / min] = polishing allowance [μm] × 103 / polishing time [min]
[Polishing conditions]
Polishing machine: Desktop polishing machine manufactured by Nippon Engis Co., Ltd. Model “EJ-380IN”
Polishing pad: Product name “MH S-15A” manufactured by Nittahs
Polishing pressure: 16.8 kPa
Surface plate rotation speed: 50 rotations / minute Head rotation speed: 50 rotations / minute Polishing allowance: 8 μm
Polishing liquid supply rate: 100 mL / min
Polishing liquid temperature: 25 ° C

<Edge roll-off amount evaluation>
The edge roll-off amount at the outer peripheral portion of the polished silicon wafer was evaluated. The evaluation of the edge roll-off amount was performed by measuring the shape displacement amount of the silicon wafer surface by using “New View 5032” manufactured by Zygo (USA). Specifically, a straight line (reference straight line) that approximates the amount of shape displacement in this area is defined as a relatively flat area at a position of 2.0 mm to 4.0 mm from the outer peripheral edge of the silicon wafer toward the center. Is subtracted using the method of least squares. Next, using the point on the reference straight line as a reference point, the difference between the silicon wafer shape displacement at the position of 0.5 mm from the outer peripheral edge and the reference point was measured, and this was used as the roll-off amount of the silicon wafer. Note that the roll-off amount is negative if the outer peripheral edge of the silicon wafer is bent, while the roll-off amount is positive if the silicon wafer is flipped up. The obtained results are shown in the column of “Roll-off amount (nm)” in Table 4.

As shown in Table 4, each of the polishing compositions of Examples 1B to 7B using a combination of roll-up amine compound A and roll-off compound B had a roll-off amount within ± 70 nm, and Comparative Example 1B, Compared to Reference Examples 2B to 4B and Comparative Examples 5B to 7B, the flatness of the surface after polishing was good. From this result, it can be confirmed that by using a combination of the roll-up amine compound A and the roll-off compound B, it is possible to realize a polished surface with good flatness with little thickness difference between the edge and the center. It was.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

Claims (11)

1. Abrasive grains, water, and the following conditions:
   (1) having a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule and having no ether bond; and
   (2) having a primary amino group and at least one of a secondary amino group and a tertiary amino group, and having no ether bond;
   An ether bond-free amine compound that satisfies at least one of
   Polishing composition whose content of the said abrasive grain is 2 weight% or less.
2. The polishing composition according to claim 1, wherein the content of the amine bond-free amine compound is less than 1% by weight.
3. The polishing composition according to claim 1 or 2, wherein the content of the abrasive grains is less than 1% by weight.
4. The polishing composition according to any one of claims 1 to 3, wherein the abrasive grains are silica particles.
5. The polishing composition according to any one of claims 1 to 4, which is used for polishing silicon.
6. Polishing composition containing abrasive grains, water, roll-up amine compound A, and roll-off compound B.
7. As the roll-up amine compound A, the following conditions:
   (1) having a hydrocarbon group having 3 or more carbon atoms between two primary amino groups in the molecule and having no ether bond; and
   (2) having a primary amino group and at least one of a secondary amino group and a tertiary amino group, and having no ether bond;
   The polishing composition according to claim 6, comprising an ether compound not containing an ether bond that satisfies at least one of the following.
8. As the roll-off compound B, the following compounds:
   (B1) at least one basic compound selected from the group consisting of ammonia, ammonium hydroxide, phosphonium hydroxide and metal hydroxide;
   (B2) an amine compound having at least one of a secondary amino group and a tertiary amino group and not having a primary amino group;
   (B3) an amine compound containing an ether bond in the molecule; and (B4) an amine compound having a hydrocarbon group having 1 or 2 carbon atoms between two primary amino groups in the molecule;
   The polishing composition according to claim 6 or 7, comprising at least one compound selected from the group consisting of:
9. The ratio of the molar concentration of the roll-up amine compound A and roll-off compound B (roll-up amine compound A: roll-off compound B) is in the range of 1: 500 to 200: 1. The polishing composition according to item.
10. The polishing composition according to any one of claims 6 to 9, wherein the abrasive grains are silica particles.
11. The polishing composition according to any one of claims 6 to 10, which is used for polishing silicon.