Chemical mechanical polishing composition and polishing method

Abstract

To provide: a chemical mechanical polishing composition capable of increasing the polishing rate of a molybdenum film while reducing corrosion of the molybdenum film; and a polishing method using the composition.SOLUTION: The chemical mechanical polishing composition according to the present invention comprises: (A) abrasive grains; (B) a compound represented by the general formula (1) in the figure; and (F) a liquid medium, and has a pH from 1 to 5 inclusive. In the formula (1), R1, R2, R4 and R6 each independently represent a hydrogen atom, an alkyl group, or an organic group having 1 to 3 carbon atoms with a hydroxy or carboxy group; R3 and R7 each independently represent an alkanediyl group; and R5 represents an alkyl group having 8 or more carbon atoms.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a composition for chemical mechanical polishing and a polishing method using the same.

Background Art

[0002] With the improvement of semiconductor integrated circuit manufacturing technology, higher integration and faster operation of semiconductor devices are required. Along with this, the flatness of the semiconductor substrate surface required in the manufacturing process of fine circuits in semiconductor devices has become increasingly strict, and chemical mechanical polishing (CMP) has become an indispensable technology in the manufacturing process of semiconductor devices.

[0003] Conventionally, tungsten, which has excellent embedding properties, has been frequently used for contact holes that electrically connect between wirings of a semiconductor substrate manufactured through CMP in the vertical and longitudinal directions. A composition for chemical mechanical polishing for polishing such a tungsten film has been proposed (see, for example, Patent Document 1). On the other hand, in recent years, in order to improve the increase in the resistance value of tungsten wirings due to miniaturization, the use of molybdenum instead of tungsten has been studied. A composition for chemical mechanical polishing for polishing such a molybdenum film has been proposed (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In CMP for forming contact holes using molybdenum, it is necessary to polish the molybdenum film deposited on a silicon oxide film at high speed, and remove the molybdenum portion other than the portion filled in the contact hole to achieve planarization. To achieve this, a chemical mechanical polishing composition with a high polishing rate for the molybdenum film is required. In addition, since molybdenum is more easily oxidized than tungsten, corrosion is more likely to occur during CMP, and there has been a problem that conventional tungsten polishing compositions cannot be used as they are.

[0006] Some aspects of the present invention provide a chemical mechanical polishing composition that can increase the polishing rate of a molybdenum film and reduce corrosion of the molybdenum film during CMP of a semiconductor wafer containing the molybdenum film, and a polishing method using the same. [Means for solving the problem]

[0007] One aspect of the chemical mechanical polishing composition of the present invention is (A) abrasive grains; (B) a compound represented by the following general formula (1), (F) a liquid medium; Contains The pH is between 1 and 5. [ka] (In formula (1), R 1 , R 2 , R 4 , and R 6 each independently represents a hydrogen atom, an alkyl group, or an organic group having 1 to 3 carbon atoms and a hydroxyl group or a carboxyl group; R 3 and R 7 each independently represents an alkanediyl group, R 5 represents an alkyl group having 8 or more carbon atoms.

[0008] In one embodiment of the chemical mechanical polishing composition, The composition may further contain at least one selected from the group consisting of (C) an iron (III) compound and (D) an oxidizing agent.

[0009] In one embodiment of the chemical mechanical polishing composition, it may further contain (C) an iron (III) compound and (E) a compound having 1 to 3 functional groups selected from the group consisting of an amino group and a salt thereof.

[0010] In one embodiment of the chemical mechanical polishing composition, the average secondary particle diameter of the component (A) may be 10 nm to 120 nm.

[0011] In one embodiment of the chemical mechanical polishing composition, when the total mass of the chemical mechanical polishing composition is 100% by mass, the content of the component (A) may be 0.1% by mass to 5% by mass.

[0012] One embodiment of the chemical mechanical polishing composition according to the present invention may be used for polishing a surface to be polished having a molybdenum film.

[0013] One embodiment of the polishing method according to the present invention includes a step of polishing a surface to be polished having a molybdenum film using the chemical mechanical polishing composition according to any of the above embodiments.

Advantages of the Invention

[0014] According to the chemical mechanical polishing composition of the present invention, in the CMP of a semiconductor wafer including a molybdenum film, the polishing rate of the molybdenum film can be increased, and the corrosion of the molybdenum film can be reduced.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and also includes various modified examples implemented without changing the gist of the present invention.

[0017] In this specification, a numerical range described as "X to Y" is interpreted as including the numerical value X as the lower limit value and including the numerical value Y as the upper limit value.

[0018] 1. Chemical Mechanical Polishing Composition The chemical mechanical polishing composition according to one embodiment of the present invention contains (A) abrasive grains (also referred to as "(A) component" in this specification), (B) a compound represented by the following general formula (1) (also referred to as "(B) component" in this specification), and (F) a liquid medium (also referred to as "(F) component" in this specification), and has a pH of 1 or more and 5 or less.

Chemical formula

[0019] Hereinafter, each component that can be included in the chemical mechanical polishing composition according to this embodiment will be described in detail.

[0020] 1.1. (A) Component The chemical mechanical polishing composition according to this embodiment contains (A) abrasive grains. Examples of the component (A) include inorganic particles such as silica, ceria, alumina, zirconia, and titania, with silica being preferred. Examples of silica include fumed silica and colloidal silica, with colloidal silica being preferred. As the colloidal silica, those produced by the methods described in, for example, JP-A-2003-109921 can be used.

[0021] When the component (A) is silica particles mainly composed of silica, other components may be further contained. Examples of other components include aluminum compounds and silicon compounds. By further containing an aluminum compound or a silicon compound in the silica particles, the surface hardness of the silica particles can be reduced, so that the occurrence of polishing scratches and dishing on the surface to be polished can be further reduced while maintaining a stable polishing rate in some cases.

[0022] Examples of the aluminum compound include aluminum hydroxide, aluminum oxide (alumina), aluminum chloride, aluminum nitride, aluminum acetate, aluminum phosphate, aluminum sulfate, sodium aluminate, potassium aluminate, etc. On the other hand, examples of the silicon compound include silicon nitride, silicon carbide, silicate, silicone, and silicone resin.

[0023] The shape of the component (A) is not particularly limited, and it may be spherical, cocoon-shaped, chain-spherical, or may have a plurality of protrusions on the surface. The abrasive grains having a plurality of protrusions on the surface can be produced, for example, by applying the methods described in JP-A-2007-153732 and JP-A-2013-121631.

[0024] The zeta potential of the component (A) is preferably -40 mV or more, more preferably -30 mV or more, still more preferably -20 mV or more, and particularly preferably - from the viewpoint of improving the dispersion stability by suppressing cross-linking aggregation with the component (B) in the chemical mechanical polishing composition. It is 10 mV or more. The zeta potential of component (A) is preferably 40 mV or less, more preferably 30 mV or less, still more preferably 20 mV or less, and particularly preferably 10 mV or less in the chemical mechanical polishing composition from the viewpoint of suppressing the number of defects in the molybdenum film.

[0025] From the viewpoints of improving dispersion stability and suppressing the number of defects in the molybdenum film, the absolute value of the zeta potential of component (A) is preferably 2 mV or more and 40 mV or less, more preferably 3 mV or more and 30 mV or less. Examples of the zeta potential measuring device include "ELSZ-2000ZS" manufactured by Otsuka Electronics Co., Ltd., "Zetasizer Ultra" manufactured by Malvern, and "DT300" manufactured by Dispersion Technology Inc.

[0026] At least a part of the surface of component (A) may be modified by a functional group. Component (A) whose at least a part of the surface is modified by a functional group has a larger absolute value of the zeta potential and an increased electrostatic repulsive force between component (A) molecules compared to component (A) whose surface is not modified by a functional group. As a result, the dispersion stability of component (A) in the chemical mechanical polishing composition is improved, and it becomes difficult for component (A) to localize on the surface of the molybdenum film. Therefore, a practical polishing rate for the molybdenum film can be obtained while reducing the dishing amount of the molybdenum film.

[0027] Component (A) can have, for example, a functional group represented by the following general formula (2). -SO3 - M + ·····(2) (M + represents a monovalent cation.)

[0028] In the above general formula (2), examples of the monovalent cation represented by M + include, but are not limited to, H + , Li + , Na + , K + , NH4 +include. That is, the functional group represented by the general formula (2) can also be paraphrased as "at least one functional group selected from the group consisting of a sulfo group and its salts". Here, the "salt of a sulfo group" refers to a functional group in which the hydrogen ion contained in the sulfo group (-SO3H) is replaced with a monovalent cation such as Li + Na + K + NH4 + and the like. The component (A) having the functional group represented by the general formula (2) is abrasive grains in which the functional group represented by the general formula (2) is fixed to the surface thereof via a covalent bond, and does not include abrasive grains to which a compound having the functional group represented by the general formula (2) is physically or ionically adsorbed.

[0029] The component (A) having the functional group represented by the general formula (2) can be produced, for example, as follows. First, silica particles produced by a known method and a mercapto group-containing silane coupling agent are sufficiently stirred in an acidic medium to covalently bond the mercapto group-containing silane coupling agent to the surface of the silica particles. Here, examples of the mercapto group-containing silane coupling agent include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Next, an appropriate amount of hydrogen peroxide is further added and left standing sufficiently to obtain the component (A) having the functional group represented by the general formula (2).

[0030] (A) The component can have, for example, a functional group represented by the following general formula (3). -COO - M + ·····(3) (M + represents a monovalent cation.)

[0031] In the general formula (3), the monovalent cation represented by M + is not limited to these, and examples include H + Li + Na + K + NH4+ include. That is, the functional group represented by the general formula (3) can also be paraphrased as "at least one functional group selected from the group consisting of a carboxy group and its salts". Here, the "salt of a carboxy group" refers to a functional group in which the hydrogen ion contained in the carboxy group (-COOH) is replaced with a monovalent cation such as Li + , Na + , K + , NH4 + , etc. The component (A) having the functional group represented by the general formula (3) is abrasive grains in which the functional group represented by the general formula (3) is fixed to the surface thereof via a covalent bond, and does not include abrasive grains to which a compound having the functional group represented by the general formula (3) is physically or ionically adsorbed on the surface thereof.

[0032] The component (A) having the functional group represented by the general formula (3) can be produced, for example, as follows. First, silica particles produced by a known method and a silane coupling agent containing a carboxylic anhydride are sufficiently stirred in a basic medium, and the silane coupling agent containing a carboxylic anhydride is covalently bonded to the surface of the silica particles, whereby abrasive grains having the functional group represented by the general formula (3) can be obtained. Here, examples of the silane coupling agent containing a carboxylic anhydride include 3-(triethoxysilyl)propyl succinic anhydride.

[0033] (A) The component may have, for example, a functional group represented by the following general formula (4) and / or the following general formula (5). -NR 8 R 9 ·····(4) -N + R 8 R 9 R 10 M - ·····(5) (In the above formula (4) and the above formula (5), R 8 , R 9 , and R 10 each independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M -represents a monovalent anion.)

[0034] The functional group represented by the general formula (4) represents an amino group, and the functional group represented by the general formula (5) represents a salt of an amino group. Therefore, the functional group represented by the general formula (4) and the functional group represented by the general formula (5) can be collectively rephrased as "at least one functional group selected from the group consisting of an amino group and its salts". The component (A) having a functional group represented by the general formula (4) and / or the general formula (5) is an abrasive grain having a functional group represented by the general formula (4) and / or the general formula (5) covalently fixed to its surface, and does not include abrasive grains to which a compound having a functional group represented by the general formula (4) and / or the general formula (5) is physically or ionically adsorbed on its surface.

[0035] In the general formula (5), M - Examples of the monovalent anion represented by include, but are not limited to, OH - , F - , Cl - , Br - , I - , CN - etc., and anions derived from acidic compounds are also included.

[0036] In the general formula (4) and the general formula (5), R 8 ~R 10 each independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and two or more of R 8 ~R 10 may combine to form a ring structure.

[0037] R 8 ~R 10The hydrocarbon group represented by [[ID=]] may be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an aralkyl hydrocarbon group, or an alicyclic hydrocarbon group. Further, the aliphatic groups of the aliphatic hydrocarbon group and the aralkyl hydrocarbon group may be saturated or unsaturated, and may be linear or branched. Examples of these hydrocarbon groups include linear, branched or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.

[0038] The component (A) having a functional group represented by the general formula (4) and / or the general formula (5) can be produced, for example, as follows. First, silica particles prepared by a known method and an amino group-containing silane coupling agent are sufficiently stirred in an acidic medium, and the amino group-containing silane coupling agent is covalently bonded to the surface of the silica particles, whereby the component (A) having a functional group represented by the general formula (4) and / or the general formula (5) can be produced. Here, examples of the amino group-containing silane coupling agent include 3-ami nopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and the like.

[0039] The average secondary particle diameter of the component (A) is obtained by measuring and converting the scattered light intensity of the chemical mechanical polishing composition with a particle size distribution measuring device using the dynamic light scattering method. The average secondary particle diameter of the component (A) measured by this method is preferably 120 nm or less, more preferably 110 nm or less, and particularly preferably 100 nm or less. Further, the average secondary particle diameter of the abrasive grains (A) is preferably 10 nm or more, more preferably 15 nm or more, and particularly preferably 20 nm or more. When the average secondary particle diameter of the component (A) is within the above range, a practical polishing rate for the molybdenum film is easily achieved. Examples of the particle size distribution measuring device include the model "Zetasizer Ultra" manufactured by Malvern. The average secondary particle diameter measured using the dynamic light scattering method represents the average particle diameter of the secondary particles formed by aggregation of the primary particles.

[0040] When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of the component (A) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. Further, when the total mass of the chemical mechanical polishing composition is 100% by mass, the content of the component (A) is preferably 5% by mass or less, more preferably 4% by mass or less. When the content of the component (A) is within the above range, the polishing rate of the molybdenum film can be increased, and the case where the molybdenum film is excessively polished and dishing occurs can be reduced.

[0041] 1.2. Component (B) The chemical mechanical polishing composition according to the present embodiment contains a compound represented by the following general formula (1) as the component (B).

Chemical formula

[0042] In the above general formula (1), R 1 , R 2 , R 4 , and R 6 are each independently preferably an alkyl group, a hydroxy group or an organic group having 1 to 3 carbon atoms having a carboxy group, and more preferably an alkyl group having 1 to 3 carbon atoms, a hydroxy group or an alkyl group having 1 to 3 carbon atoms having a carboxy group. That is, in the above general formula (1), R 1 , R 2 , R 4 , and R 6 are each independently -CH3, -(CH2) m CH3, -(CH2) n OH, and -(CH2) mIt is more preferable that it is a group selected from the group consisting of COOH (where m is an integer of 1 or 2 and n is an integer of 1 to 3).

[0043] In the above general formula (1), R 3 and R 7 are alkanediyl groups, and an alkanediyl group having 1 to 3 carbon atoms is preferable.

[0044] In the above general formula (1), R 5 is an alkyl group having 8 or more carbon atoms, preferably an alkyl group having 9 or more carbon atoms, more preferably an alkyl group having 10 or more carbon atoms. Examples of the alkyl group having 8 or more carbon atoms include an octyl group, an ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, and the like.

[0045] Since the surface potential of the molybdenum film becomes negative in the range where the pH is 1 or more and 5 or less, it is considered that the (B) component that becomes positively charged during CMP adsorbs in a large amount on the surface of the molybdenum film to form a protective film. As a result, it is considered that excessive corrosion of the molybdenum film is suppressed. On the other hand, when the pH is not 1 or more and 5 or less, the (B) component cannot adsorb on the surface of the molybdenum film to form a protective film, and the surface of the molybdenum film is likely to be corroded during CMP, so it is considered that polishing defects occur.

[0046] Specific examples of the (B) component include N represented by the following formula (B-1) 1 -(2-(diethylamino)ethyl)-N 1 -dodecyl-N 2 ,N 2 -diethylethane-1,2-diamine, N represented by the following formula (B-2) 1 -(2-aminoethyl)-N 1 -dodecylethane-1,2-diamine, N represented by the following formula (B-3) 1-(2-(dimethylamino)ethyl)-N 1 -dodecyl-N 2 ,N 2 -dimethylethane-1,2-diamine, N represented by the following formula (B-4) 1 -(3-(dimethylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -dimethylpropane-1,3-diamine, N represented by the following formula (B-5) 1 -(3-(diethylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -diethylpropane-1,3-diamine, N represented by the following formula (B-6) 1 -(3-(dipropylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -dipropylpropane-1,3-diamine, 3,3’,3’’,3’’’-(((octylazanediyl)bis(ethane-2,1-diyl))bis(azanetriyl))tetrapropionic acid represented by the following formula (B-7), 2,2’,2’’,2’’’-(((tetradecylazanediyl)bis(ethane-2,1-diyl))bis(azanetriyl))tetrakis(ethan-1-ol) represented by the following formula (B-8), etc. may be mentioned. These (B) components may be used alone or in combination of two or more.

[0047]

Chemical formula

[0048] When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (B) is preferably 0.001% by mass or more, more preferably 0.002% by mass or more. When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (B) is preferably 0.1% by mass or less, more preferably 0.05% by mass or less. When the content of component (B) is within the above range, excessive corrosion of the molybdenum film may be effectively suppressed.

[0049] 1.3. Component (C) and Component (D) The chemical mechanical polishing composition according to the present embodiment preferably further contains at least one selected from the group consisting of (C) iron(III) compound (also referred to as “component (C)” in this specification) and (D) oxidizing agent other than component (C) (also referred to as “component (D)” in this specification).

[0050] 1.3.1. Component (C) The chemical mechanical polishing composition according to the present embodiment preferably contains component (C). Component (C) has an action of oxidizing the surface of the molybdenum film to create a fragile modified layer and promoting the polishing of the molybdenum film. In addition, the modified layer may have an action of suppressing the corrosion of the molybdenum film.

[0051] As component (C), any of iron(III) organic acid salts and iron(III) inorganic acid salts may be used as long as they have the above-described action.

[0052] Specific examples of component (C) include iron(III) nitrate, ammonium iron(III) sulfate, iron(III) perchlorate, iron(III) chloride, iron(III) sulfate, iron(III) citrate, ammonium iron(III) citrate, and ammonium iron(III) oxalate. Among these components (C), iron(III) nitrate is particularly preferred. Component (C) may be used alone or in combination of two or more. In addition, since component (C) has the same effect as component (D), it may be used alone without combination with component (D) or in combination with component (D).

[0053] (C) component content, when the total mass of the chemical mechanical polishing composition is 100% by mass, is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and particularly preferably 0.03% by mass or more. From the viewpoint of suppressing corrosion of the molybdenum film, the content of (C) component, when the total mass of the chemical mechanical polishing composition is 100% by mass, is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and particularly preferably 0.15% by mass or less. When the content of (C) component is within the above range, it may be possible to polish the molybdenum film at high speed while suppressing corrosion of the molybdenum film.

[0054] 1.3.2. (D) component The chemical mechanical polishing composition according to this embodiment may contain (D) component. By containing (D) component, the effect of creating a fragile modified layer on the surface of the molybdenum film may be promoted, and the polishing rate of the molybdenum film may be increased.

[0055] Examples of (D) component include hydrogen peroxide, peracetic acid, percarbonate, urea peroxide, perchloric acid, persulfates (e.g., sodium persulfate, potassium persulfate, ammonium persulfate), etc. Among these (D) components, hydrogen peroxide is particularly preferred considering oxidation power, compatibility with (C) component, and ease of handling. (D) component may be used alone or in combination of two or more. Also, since (D) component has the same effect as (C) component, it may be used alone without combination with (C) component or in combination with (C) component.

[0056] When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (D) is preferably 0.01% by mass or more, more preferably 0.02% by mass or more. When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (D) is preferably 1% by mass or less, more preferably 0.1% by mass or less. When the content of component (D) is within the above range, it may be possible to polish the molybdenum film at high speed while suppressing corrosion of the molybdenum film.

[0057] 1.4. Component (E) The chemical mechanical polishing composition according to the present embodiment preferably contains a compound having 1 to 3 functional groups selected from the group consisting of (E) an amino group and its salts (also referred to as “component (E)” in this specification). Since it is difficult to obtain a sufficient effect of reducing the corrosion of the molybdenum film even when component (E) is used alone, it is preferable to use component (B) and component (E) in combination. By using component (B) and component (E) in combination, it may be possible to obtain an effect of synergistically reducing the corrosion of the molybdenum film while maintaining a high polishing rate of the molybdenum film. Also, from the viewpoint of effectively improving the etching rate of the molybdenum film, it is also preferable to use component (C) and component (E) in combination.

[0058] Examples of the amino group and its salts include functional groups represented by the following general formula (6) or the following general formula (7). -NR 10 R 11 ·····(6) -N + R 10 R 11 R 12 M - ·····(7) (In the above formula (6) and the above formula (7), R 10 , R 11 , and R 12 each independently represent a hydrogen atom, or a substituted or unsubstituted hydrocarbon group. M - represents a monovalent anion.)

[0059] In the above general formula (6) and the above general formula (7), M- Examples of the monovalent anion represented by [the formula] include OH - 、F - 、Cl - 、Br - 、I - 、NO3 - 、HCO3 - and the like.

[0060] In the above general formula (6) and the above general formula (7), R 10 、R 11 、and R 12 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group, provided that two or more of R 10 *、R 11 、and R 12 may combine to form a ring structure. Further, when at least any one of R 10 、R 11 、and R 12 is a substituted hydrocarbon group, the substituent is preferably a carboxy group represented by the following general formula (8) or a salt thereof.

[0061] -COO - M + ·····(8) (M + represents a monovalent cation.)

[0062] In the above general formula (8), examples of the monovalent cation represented by M + include, but are not limited to, for example, H + *、Li + 、Na + 、K + 、NH4 + and the like.

[0063] R 10 ~R 12 *Note: There seems to be a redundant '*' in the translation of line 27 which might be a typo in the original text. Also, the line breaks are maintained as per the requirement.The hydrocarbon group represented by may be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an araliphatic hydrocarbon group, or an alicyclic hydrocarbon group. Further, the aliphatic groups of the aliphatic hydrocarbon group and the araliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. Examples of these hydrocarbon groups include linear, branched, or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups, etc.

[0064] As the alkyl group, a lower alkyl group having 1 to 6 carbon atoms is preferable, and a lower alkyl group having 1 to 4 carbon atoms is more preferable. Examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, a cyclopentyl group, a cyclohexyl group, etc.

[0065] As the alkenyl group, a lower alkenyl group having 1 to 6 carbon atoms is preferable, and a lower alkenyl group having 1 to 4 carbon atoms is more preferable. Examples of such an alkenyl group include a vinyl group, an n-propenyl group, an iso-propenyl group, an n-butenyl group, an iso-butenyl group, a sec-butenyl group, a tert-butenyl group, etc.

[0066] As the aralkyl group, those having 7 to 12 carbon atoms are preferable. Examples of such an aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, a phenylhexyl group, a methylbenzyl group, a methylphenethyl group, an ethylbenzyl group, etc.

[0067] As the aryl group, those having 6 to 14 carbon atoms are preferable. Examples of such an aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2,3-xylyl group, a 2,4-xylyl group, a 2,5-xylyl group, a 2,6-xylyl group, a 3,5-xylyl group, a naphthyl group, an anthryl group, etc.

[0068] The aromatic rings of the aryl group and the aralkyl group may have, as substituents, for example, lower alkyl groups such as a methyl group and an ethyl group, a halogen atom, a nitro group, an amino group, a hydroxy group and the like.

[0069] The component (E) is not particularly limited as long as it is a compound having 1 to 3 functional groups selected from the group consisting of an amino group and its salts, but preferably has a structure represented by the following general formula (9) or the following general formula (10). -N(R 13 N + M - ) n (R 14 ) 2-n ·····(9) -N(R 13 COO - M + ) n (R 14 ) 2-n ·····(10) (In the above formula (9) and the above formula (10), each R 13 independently represents a substituted or unsubstituted divalent hydrocarbon group. Each R 14 independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M - represents a monovalent anion. M + represents a monovalent cation. n represents an integer of 1 to 2.)

[0070] In the above general formula (9) and the above general formula (10), examples of the divalent hydrocarbon group represented by R 13 include an alkanediyl group having 1 to 3 carbon atoms. In the above general formula (9) and the above general formula (10), the hydrocarbon group represented by R 14 is preferably an alkyl group having 10 or more carbon atoms. Examples of the alkyl group having 10 or more carbon atoms include a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group and the like. In the above general formula (9), M -Examples of the monovalent anion represented by include OH - , F - , Cl - , Br - , I - , NO3 - , HCO3 - and so on. In the above general formula (10), examples of the monovalent cation represented by M + include H + , Li + , Na + , K + , NH4 + .

[0071] (E) component has the structure represented by the above general formula (9) and / or the above general formula (10), so that the amino group in the (E) component is likely to adsorb on the surface of the molybdenum film, and thus the corrosion of the molybdenum site can be effectively reduced. In addition, by further having a carboxy group as in the structure represented by the above general formula (10), the (E) component can be effectively adsorbed on the surface of the molybdenum film, so that the corrosion may be more effectively reduced.

[0072] Specific examples of the (E) component include dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, N-methyloctadecylamine, N,N-dimethyldodecylamine, N-(2-{[2-(dodecylamino)ethyl]amino}ethyl)glycine, 2,6,10-trimethyl-2,6,10-triazadecane, ethylenediaminetetraacetic acid, lauryliminodipropionate, myristyliminodipropionate, stearyliminodipropionate, palmityliminodipropionate, cocamidopropylamine oxide, benzyldimethylhexadecylammonium chloride, benzalkonium chloride and the like. These (E) components may be used alone or in combination of two or more.

[0073] When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (E) is preferably 0.01% by mass or more, more preferably 0.02% by mass or more. When the total mass of the chemical mechanical polishing composition is 100% by mass, the content of component (E) is preferably 0.2% by mass or less, more preferably 0.15% by mass or less. When the content of component (E) is within the above range, while effectively reducing the corrosion of the molybdenum film, the dispersion stability of component (A) may be improved by suppressing cross-linking aggregation with component (A).

[0074] 1.5. (F) Liquid medium The chemical mechanical polishing composition according to the present embodiment contains a (F) liquid medium (also referred to as "( F) component" in this specification). Examples of the (F) component include water, a mixed medium of water and alcohol, and a mixed medium containing an organic solvent having compatibility with water and water. Among these, it is preferable to use water or a mixed medium of water and alcohol, and more preferable to use water. Pure water can be preferably used as the raw material of water. The (F) component may be blended as the balance of the above-mentioned respective components.

[0075] 1.6. Other components The chemical mechanical polishing composition according to the present embodiment may contain additives such as acidic compounds, surfactants, water-soluble polymers, corrosion inhibitors, and pH adjusters, as necessary, in addition to the above-mentioned respective components. Each additive will be described below.

[0076] 1.6.1. Acidic compound The chemical mechanical polishing composition according to the present embodiment may contain an acidic compound. Examples of the acidic compound include organic acids and inorganic acids. By containing an acidic compound, the polishing rate of the molybdenum film may be further increased due to the interaction with the (A) abrasive grains.

[0077] Examples of the organic acid include monocarboxylic acids such as lactic acid, glycolic acid, formic acid, acetic acid, benzoic acid, p-hydroxybenzoic acid, quinaldic acid, glycine, alanine, lysine, arginine, tryptophan; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, maleic acid, phthalic acid, tartaric acid, aspartic acid, glutamic acid; polycarboxylic acids such as citric acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, polyacrylic acid, polymaleic acid; diphosphonic acids such as 1-hydroxyethane-1,1-diphosphonic acid; aromatic amino acids and heterocyclic amino acids other than those described above; and amidosulfuric acid. These organic acids may form salts. These organic acids may be used alone or in combination of two or more in any ratio.

[0078] Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. These inorganic acids may form salts. These inorganic acids may be used alone or in combination of two or more in any ratio.

[0079] When the acidic compound is contained, the content of the acidic compound is preferably 0.001 to 3% by mass, more preferably 0.002 to 2% by mass, and particularly preferably 0.003 to 1% by mass, based on 100% by mass of the total mass of the chemical mechanical polishing composition.

[0080] 1.6.2. Surfactant The chemical mechanical polishing composition according to the present embodiment may contain a surfactant. By containing a surfactant, appropriate viscosity may be imparted to the chemical mechanical polishing composition.

[0081] Examples of surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, etc. Examples of anionic surfactants include carboxylates such as fatty acid soaps and alkyl ether carboxylates; sulfonates such as alkylbenzene sulfonates, alkylnaphthalene sulfonates, and α-olefin sulfonates; sulfates such as higher alcohol sulfates, alkyl ether sulfates, and polyoxyethylene alkyl phenyl ether sulfates; fluorine-containing surfactants such as perfluoroalkyl compounds, etc. Examples of cationic surfactants include aliphatic amine salts, aliphatic ammonium salts, etc. Examples of nonionic surfactants include nonionic surfactants having a triple bond such as acetylene glycol, ethylene oxide adduct of acetylene glycol, and acetylene alcohol; polyethylene glycol type surfactants, etc. These surfactants may be used alone or in combination of two or more.

[0082] When the surfactant is contained, the content of the surfactant is preferably 0.001 to 5% by mass, more preferably 0.001 to 3% by mass, and particularly preferably 0.01 to 1% by mass when the total mass of the chemical mechanical polishing composition is 100% by mass.

[0083] 1.6.3. Water-soluble polymer The chemical mechanical polishing composition according to this embodiment may contain a water-soluble polymer. When the water-soluble polymer adsorbs on the surface to be polished and reduces the polishing friction, it may be possible to reduce the occurrence of polishing defects such as dishing, erosion, and scratches on the surface to be polished.

[0084] Examples of such water-soluble polymers include polyacrylamide, polyvinyl alcohol, polyvinyl pyrrolidone, polyethyleneimine, polyvinyl methyl ether, polyallylamine, hydroxyethyl cellulose, etc.

[0085] The weight average molecular weight (Mw) of the water-soluble polymer is preferably from 1,000 to 1,500,000, more preferably from 10,000 to 500,000, and particularly preferably from 30,000 to 100,000. When the weight average molecular weight of the water-soluble polymer is within the above range, the water-soluble polymer is likely to adsorb to the surface to be polished, and the polishing friction is further reduced. As a result, it may be possible to reduce the occurrence of polishing defects such as dishing, erosion, and scratches on the surface to be polished. Note that the "weight average molecular weight (Mw)" in this specification refers to the weight average molecular weight in terms of polyethylene glycol measured by GPC (gel permeation chromatography).

[0086] When containing a water-soluble polymer, the content of the water-soluble polymer is preferably from 0.001 to 1% by mass, more preferably from 0.002 to 0.1% by mass, based on 100% by mass of the total mass of the chemical mechanical polishing composition. Note that the content of the water-soluble polymer also depends on the weight average molecular weight (Mw) of the water-soluble polymer, but it is preferably adjusted so that the viscosity of the chemical mechanical polishing composition is less than 10 mPa·s. When the viscosity of the chemical mechanical polishing composition is less than 10 mPa·s, it is easy to polish the molybdenum film at high speed, and since the viscosity is appropriate, the chemical mechanical polishing composition can be stably supplied onto the polishing cloth.

[0087] 1.6.4. Corrosion inhibitor The chemical mechanical polishing composition according to the present embodiment may contain a corrosion inhibitor. Examples of the corrosion inhibitor include benzotriazole and its derivatives. Here, the benzotriazole derivative refers to a compound in which one or more hydrogen atoms of benzotriazole are substituted with a carboxy group, a methyl group, an amino group, a hydroxy group, or the like. Examples of the benzotriazole derivative include 4-carboxybenzotriazole and its salts, 7-carboxybenzotriazole and its salts, benzotriazole butyl ester, 1-hydroxymethylbenzotriazole, 1-hydroxybenzotriazole, and the like.

[0088] When containing an anticorrosive agent, the content of the anticorrosive agent is preferably 1% by mass or less, more preferably 0.001 to 0.1% by mass, based on 100% by mass of the total mass of the chemical mechanical polishing composition.

[0089] 1.6.5. pH Adjusting Agent The chemical mechanical polishing composition according to the present embodiment may further contain a pH adjusting agent in order to adjust the pH of the chemical mechanical polishing composition to a desired value. Examples of the pH adjusting agent include acidic compounds such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and monocarboxylic acid described above, and basic compounds such as sodium hydroxide, potassium hydroxide, TMAH (tetramethylammonium hydroxide), and ammonia.

[0090] Note that the pH of the chemical mechanical polishing composition according to the present embodiment can be appropriately adjusted to be strongly acidic within the recommended pH range by the action of a catalyst such as the component (C). And by adjusting the addition amount of the additive according to the object to be polished, a polished surface with higher flatness can be obtained.

[0091] 1.7. pH The pH of the chemical mechanical polishing composition according to the present embodiment is 1 or more, preferably 1.5 or more, more preferably 2 or more, from the viewpoint of the storage stability of the component (A). The pH of the chemical mechanical polishing composition according to the present embodiment is 5 or less, preferably 4 or less, more preferably 3 or less, from the viewpoint of effectively expressing the etching action of the molybdenum film. When the pH of the chemical mechanical polishing composition is within the above range, a chemical mechanical polishing composition capable of achieving both the storage stability of the component (A) and the effective etching action of the molybdenum film can be obtained.

[0092] Note that the pH of the chemical mechanical polishing composition can be adjusted, for example, by adding the above-mentioned pH adjusting agent or the like, and one or more of these can be used.

[0093] In the present invention, pH refers to the hydrogen ion exponent, and its value can be measured using a commercially available pH meter (for example, a desktop pH meter manufactured by Horiba, Ltd.).

[0094] 1.8. Use The chemical mechanical polishing composition according to this embodiment can be mainly used as an abrasive for polishing a polished surface having a molybdenum film among a plurality of substrates constituting a semiconductor device. For example, in a workpiece having an insulating film having contact holes and a molybdenum film provided in the contact holes and on the insulating film, it can be used in a process of polishing the molybdenum film on the insulating film to form a molybdenum plug (Mo-plug) embedded in the contact holes in the insulating film.

[0095] 1.9. Method for preparing the chemical mechanical polishing composition The chemical mechanical polishing composition according to this embodiment can be prepared by dissolving or dispersing each of the above components in a liquid medium such as water. The method of dissolving or dispersing is not particularly limited, and any method can be applied as long as it can be uniformly dissolved or dispersed. Also, the mixing order and mixing method of each of the above components are not particularly limited.

[0096] Further, the chemical mechanical polishing composition according to this embodiment can be prepared as a concentrated stock solution and diluted with a liquid medium such as water at the time of use.

[0097] 2. Polishing method The polishing method according to an embodiment of the present invention includes a step of polishing a polished surface having a molybdenum film using the above-described chemical mechanical polishing composition. According to the chemical mechanical polishing composition of the present invention, the polishing rate of the molybdenum film can be increased, and the occurrence of corrosion on the molybdenum surface can be reduced, so that a molybdenum plug of good quality can be formed. Hereinafter, the polishing method according to this embodiment will be described in detail with reference to FIGS. 1 to 3.

[0098] 2.1. Workpiece FIG. 1 shows an example of a workpiece 100 to which the polishing method according to the present embodiment is applied. The workpiece 100 is produced, for example, through the following steps (1) to (4).

[0099] (1) First, as shown in FIG. 1, a substrate 10 is prepared. The substrate 10 may be composed of, for example, a silicon substrate and a silicon oxide film formed thereon. Further, functional devices such as transistors may be formed on the substrate 10. Functional devices such as transistors may be formed on the substrate 10.

[0100] (2) Next, a silicon oxide film 12, which is an insulating film, is formed on the substrate 10 by a CVD method using silane gas and oxygen gas. Thereafter, the silicon oxide film 12 is polished halfway by CMP to planarize the surface.

[0101] (3) Next, a resist pattern is formed on the silicon oxide film 12. Using this as a mask, the silicon oxide film 12 is etched to form a contact hole 14. After the contact hole 14 is formed, the resist pattern is removed.

[0102] (4) Next, by applying the CVD method, a molybdenum film 16 is deposited on the surface of the silicon oxide film 12 and inside the contact hole 14.

[0103] The workpiece 100 is formed through the above steps.

[0104] 2.2 Chemical Mechanical Polishing Step In the chemical mechanical polishing step, as shown in FIG. 2, the molybdenum film 16 is polished using the chemical mechanical polishing composition of the present invention until the silicon oxide film 12 is exposed. According to the chemical mechanical polishing composition of the present invention, the polishing rate of the molybdenum film is high, and the occurrence of corrosion on the molybdenum surface can be reduced, so that a molybdenum plug of good quality can be formed.

[0105] After the chemical mechanical polishing process, it is preferable to remove the abrasive grains remaining on the polished surface. This removal of the abrasive grains can be performed by ordinary cleaning methods. For example, after brush scrub cleaning, cleaning is performed with an alkaline cleaning solution having a mass ratio of ammonia: hydrogen peroxide: water of about 1:1:5, whereby the abrasive grains adhering to the polished surface can be removed. Further, as a cleaning solution for impurity metal species adsorbed on the polished surface, for example, an aqueous citric acid solution, a mixed aqueous solution of hydrofluoric acid and citric acid, a mixed aqueous solution of hydrofluoric acid and ethylenediaminetetraacetic acid (EDTA), etc. can be used.

[0106] 2.3. Chemical Mechanical Polishing Apparatus In the above chemical mechanical polishing process, for example, a chemical mechanical polishing apparatus 200 as shown in FIG. 3 can be used. FIG. 3 is a perspective view schematically showing the chemical mechanical polishing apparatus 200. The slurry (chemical mechanical polishing composition) 44 is supplied from the slurry supply nozzle 42, and while rotating the turntable 48 to which the polishing pad 46 is attached, the carrier head 52 holding the semiconductor substrate 50 is brought into contact therewith. In addition, a water supply nozzle 54 and a dresser 56 are also shown in FIG. 3.

[0107] The polishing load of the carrier head 52 can be selected within the range of 10 to 980 hPa, preferably 30 to 490 hPa. Also, the rotation speeds of the turntable 48 and the carrier head 52 can be appropriately selected within the range of 10 to 400 rpm, preferably 30 to 150 rpm. The flow rate of the slurry (chemical mechanical polishing composition) 44 supplied from the slurry supply nozzle 42 can be selected within the range of 10 to 1,000 mL / min, preferably 50 to 400 mL / min.

[0108] Examples of commercially available chemical mechanical polishing apparatuses include those manufactured by Ebara Corporation, models "EPO-112", "EPO-222", "F-REX300SII"; those manufactured by Lapmaster SFT, models "LGP-510", "LGP-552"; those manufactured by Applied Materials, models "Mirra", "Reflexion"; those manufactured by G&P TECHNOLOGY, model "POLI-762", etc.

[0109] 3. Examples Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in this example are based on mass unless otherwise specified.

[0110] 3.1. Preparation of silica particle aqueous dispersion 3.1.1. Preparation of aqueous dispersion A 100 parts by mass of methanol, 11 parts by mass of ultrapure water, and 6 parts by mass of 28% aqueous ammonia were mixed to prepare a mother liquor. 50 parts by mass of tetramethoxysilane and 14 parts by mass of methanol were mixed with respect to 100 parts by mass of methanol used in the mother liquor to obtain an alkoxysilane solution. 34 parts by mass of ultrapure water and 5 parts by mass of 28% aqueous ammonia were mixed to obtain an alkali catalyst solution. The raw material solution and the alkali catalyst solution were injected into the mother liquor at a constant rate over 60 minutes while maintaining the temperature of the mother liquor at 25°C to obtain a reaction solution. The alkali catalyst concentration in the mother liquor was 0.68 mol / L. The alcohol concentration in the alkoxysilane solution was 6.5 mol / L. The total amount of water charged in the reaction system was 8.9 mol per 1 mol of the injection amount of tetramethoxysilane. While heating the obtained 100 parts by mass of the reaction solution to distill off the solvent, 190 parts by mass of ultrapure water was added to completely replace the solvent component with water while maintaining a constant volume, and a colloidal silica dispersion was obtained. This colloidal silica dispersion was used as aqueous dispersion A. When the average secondary particle diameter of the silica particles in aqueous dispersion A was measured, it was 98 nm. In addition, the average secondary particle diameter of each silica particle in aqueous dispersions A to E was converted from the scattered light intensity measured by a particle size distribution measuring device (manufactured by Malvern, model "Zetasizer Ultra").

[0111] 3.1.2. Preparation of aqueous dispersion B PL-1 (manufactured by Fuso Chemical Industry Co., Ltd., 12% colloidal silica dispersion) was used as aqueous dispersion B. When the average secondary particle diameter of the silica particles in aqueous dispersion B was measured, it was 42 nm.

[0112] 3.1.3. Preparation of Aqueous Dispersion C PL-3 (manufactured by Fuso Chemical Industry Co., Ltd., 19.5% colloidal silica dispersion) was used as Aqueous Dispersion C. When the average secondary particle diameter of the silica particles in Aqueous Dispersion C was measured, it was 71 nm.

[0113] 3.1.4. Preparation of Aqueous Dispersion D 25% aqueous ammonia (manufactured by Fujifilm Wako Pure Chemical Corporation) was added to 3250 g of PL-1 (manufactured by Fuso Chemical Industry Co., Ltd., 12% colloidal silica dispersion) and adjusted to pH 9. Then, 3.9 g of a (3-triethoxysilyl) mercapto group-containing silane coupling agent (trade name "KBM-803", manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise and stirred at 60 °C for 2 hours. Then, 50 g of hydrogen peroxide (manufactured by Fujifilm Wako Pure Chemical Corporation) was added and refluxed for 8 hours to obtain Aqueous Dispersion D containing silica particles surface-modified with sulfonic groups. When the average secondary particle diameter of the silica particles in Aqueous Dispersion D was measured, it was 42 nm.

[0114] 3.1.5. Preparation of Aqueous Dispersion E According to Example 3 described in International Publication No. WO2008 / 123373, an aqueous dispersion E with a pH of 7.6 containing 15.5% by mass of silica particles was obtained. When the average secondary particle diameter of the silica particles in Aqueous Dispersion E was measured, it was 15 nm.

[0115] 3.2. Preparation of Component (B) 3.2.1. Preparation of IFVM-003 N 1 -(2-(diethylamino)ethyl)-N 1 -dodecyl-N 2 ,N 2 -diethylethane-1,2-diamine (also referred to as "IFVM-003" in this specification) was synthesized as follows.

Chemical formula

[0116] 7.26 g (33.7 mmol) of N,N,N’,N’-tetraethyldiethylenetriamine (manufactured by Merck) and 3.88 g (28 mmol) of potassium carbonate (manufactured by Fujifilm Wako Pure Chemical Corporation) were added to 30 mL of acetone (manufactured by Tokyo Chemical Industry Co., Ltd.), and the mixture was heated under reflux. To this refluxing liquid, a solution prepared by dissolving 7.0 g (28 mmol) of 1-bromododecane (manufactured by Tokyo Chemical Industry Co., Ltd.) in 30 mL of acetone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1 hour, and the mixture was stirred for 8 hours under heating under reflux. After completion of the reaction, the mixture was returned to room temperature and 20 mL of water was added to the filtered filtrate. Then, 30 mL of dichloromethane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added thereto, and the operation of recovering the organic layer was performed 3 times. Anhydrous sodium sulfate (manufactured by Fujifilm Wako Pure Chemical Corporation) was added to the recovered organic layer, and the filtered filtrate was concentrated under reduced pressure to obtain IFVM-003.

[0117] 3.2.2. Preparation of IFVM-007 N represented by the following formula (B-2) 1 -(2-aminoethyl)-N 1 -dodecylethane-1,2-diamine (also referred to as "IFVM-007" in this specification) was synthesized as follows.

Chemical formula

[0118] In a 500 mL three-necked flask, 21.20 g (200 mmol) of benzaldehyde (manufactured by Fujifilm Wako Pure Chemical Corporation), 20.63 g (200 mmol) of diethylenetriamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 250 mL of tetrahydrofuran were added, and the mixture was stirred for 1 hour under a nitrogen atmosphere and heating under reflux. 13.8 g (100 mmol) of potassium carbonate, 24.9 g (100 mmol) of bromododecane (manufactured by Tokyo Chemical Industry Co., Ltd.), and 250 mL of tetrahydrofuran were added thereto, and the mixture was further stirred for 6 hours. After completion of the reaction, the mixture was returned to room temperature, the salt was removed with a pleated filter paper, and the filtrate was collected. The filtrate was concentrated under reduced pressure using an evaporator. 100 mL of ultrapure water and 30 mL of concentrated hydrochloric acid were added to the concentrate. After further adding ultrapure water, liquid-liquid purification was performed with diisopropyl ether (manufactured by Fujifilm Wako Pure Chemical Corporation), and the aqueous layer was collected. After adding an aqueous solution of potassium hydroxide (manufactured by Fujifilm Wako Pure Chemical Corporation), extraction was performed with methylene chloride to collect the organic layer, and dehydration with anhydrous sodium sulfate, solvent distillation, and vacuum drying were carried out to obtain IFVM-007.

[0119] 3.2.3. Preparation of IFVM-005 N represented by the following formula (B-3) 1 -(2-(dimethylamino)ethyl)-N 1 -dodecyl-N 2 ,N 2 -dimethylethane-1,2-diamine (also referred to as "IFVM-005" in this specification) was synthesized as follows.

[0120]

Chemical formula

[0121] 3.2.4. Preparation of IFVM-006 N represented by the following formula (B-4) 1 -(3-(dimethylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -dimethylpropane-1,3-diamine (hereinafter also referred to as "IFVM-006" in this specification) was synthesized as follows.

Chemical formula

[0122] The same operations as the preparation of IFVM-005 were performed except that 2.99 g (10 mmol) of N-(3-Aminopropyl)-n-dodecylpropane-1,3-diamine (manufactured by combi-Blocks) was used instead of IFVM-007 to obtain IFVM-006.

[0123] 3.2.5. Preparation of IFVM-008 N represented by the following formula (B-5) 1 -(3-(diethylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -diethylpropane-1,3-diamine (hereinafter also referred to as "IFVM-008" in this specification) was synthesized as follows.

Chem.

[0124] In a 300 mL three-necked flask, 1.50 g (5 mmol) of N-(3-Aminopropyl)-n-dodecyl 1,3-diaminopropane, 5.40 g (50 mmol) of bromoethane, 1.38 g (10 mmol) of potassium carbonate, and 40 mL of N,N-dimethylformamide were added. The mixture was stirred for 7 hours under a nitrogen atmosphere with heating under reflux. After the reaction was completed, the mixture was returned to room temperature, and the salts were removed with a pleated filter paper, and the filtrate was collected. The filtrate was washed with hexane (manufactured by FUJIFILM Wako Pure Chemical Corporation), then dichloromethane was added, and the mixture was washed with water. The organic layer was collected, dehydrated with anhydrous sodium sulfate, the solvent was distilled off, and vacuum drying was performed to obtain IFVM-008.

[0125] 3.2.6. Preparation of IFVM-010 N represented by the following formula (B-6) 1 -(3-(dipropylamino)propyl)-N 1 -dodecyl-N 3 ,N 3 -dipropylpropane-1,3-diamine (also referred to as "IFVM-010" in this specification) was synthesized as follows.

Chem.

[0126] The same operations as those for the preparation of IFVM-008 were carried out except that 6.10 g (50 mmol) of bromopropane was used instead of 5.40 g (50 mmol) of bromoethane to obtain IFVM-010.

[0127] 3.2.7. Preparation of IFVM-013 3,3',3'',3'''-(((octylazanediyl)bis(ethane-2,1-diyl))bis(azanetriyl))tetrapropionic acid (also referred to as "IFVM-013" in this specification) represented by the following formula (B-7) was synthesized as follows. [ka]

[0128] A 500 mL three-neck flask was charged with 21.20 g (200 mmol) of benzaldehyde (Fujifilm Wako Pure Chemical Industries, Ltd.), 20.63 g (200 mmol) of diethylenetriamine (Tokyo Chemical Industry Co., Ltd.), and 250 mL of tetrahydrofuran, and the mixture was stirred for 1 hour under reflux in a nitrogen atmosphere. 13.8 g (100 mmol) of potassium carbonate, 19.3 g (100 mmol) of bromooctane (Tokyo Chemical Industry Co., Ltd.), and 250 mL of tetrahydrofuran were added, and the mixture was stirred for an additional 6 hours. After the reaction was completed, the mixture was returned to room temperature, the salt was removed using pleated filter paper, and the filtrate was collected. The filtrate was concentrated under reduced pressure using an evaporator. 100 mL of ultrapure water and 30 mL of concentrated hydrochloric acid were added to the concentrate. Further ultrapure water was added, and then diisopropyl ether (Fujifilm Wako Pure Chemical Industries, Ltd.) was added. The mixture was purified liquid-liquid using a solvent-based filtration system (manufactured by Wako Pure Chemical Industries, Ltd.), and the aqueous layer was collected. After adding an aqueous solution of potassium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), the mixture was extracted with methylene chloride, dehydrated using anhydrous sodium sulfate, the solvent evaporated, and dried under vacuum to obtain a yellow viscous liquid. 2.15 g (10 mmol) of the yellow viscous liquid, 5.42 g (50 mmol) of 3-chloropropionic acid (manufactured by SIGMA-ALDRICH), 1.38 g (10 mmol) of potassium carbonate, and 40 mL of N,N-dimethylformamide were placed in a 300 mL three-neck flask and stirred under nitrogen atmosphere for 7 hours under reflux. After the reaction was complete, the mixture was returned to room temperature, the salt was removed using pleated filter paper, and the filtrate was collected. The filtrate was washed with hexane, followed by the addition of dichloromethane and washing with water. The organic layer was collected, dehydrated using anhydrous sodium sulfate, the solvent evaporated, and dried under vacuum to obtain IFVM-013.

[0129] Preparation of IFVM-014 2,2’,2’’,2’’’-(((Tetradecylazanediyl)bis(ethane-2,1-diyl))bis(azanetriyl))tetrakis(ethan-1-ol) (also referred to as "IFVM-014" in this specification) was synthesized as follows. [Chemical formula] The same procedures as those for the preparation of IFVM-013 were carried out, except that 27.7 g (100 mmol) of bromotetradecane (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 19.3 g (100 mmol) of bromooctane, and 4.03 g (50 mmol) of 2-chloroethanol (manufactured by SIGMA-ALDRICH) was used instead of 5.42 g (50 mmol) of 3-chloropropionic acid, to obtain IFVM-014.

[0130] 3.3. Preparation of Chemical Mechanical Polishing Compositions Each component was mixed to obtain the compositions shown in Tables 1 to 3, and nitric acid (manufactured by Kanto Chemical Co., Inc., trade name "Nitric Acid 1.38") was added in Examples 1 to 4, 8 to 15, and Comparative Examples 2 to 6, malonic acid (manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Malonic Acid") was added in Example 5, maleic acid (manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Maleic Acid") was added in Example 6, citric acid (manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Citric Acid") was added in Example 7, and an aqueous potassium hydroxide solution (manufactured by Kanto Chemical Co., Inc., trade name "48% Aqueous Potassium Hydroxide Solution") was added in Comparative Example 1 to adjust the pH so that the pH values shown in Tables 1 to 3 were obtained. Then, pure water was added so that the total amount of all components was 100 parts by mass, to prepare the chemical mechanical polishing compositions of each Example and each Comparative Example.

[0131] The results of measuring the zeta potential of the abrasive grains using a zeta potential measuring device (manufactured by Dispersion Technology Inc., model "DT300") for each of the thus-obtained chemical mechanical polishing compositions are shown together in Tables 1 to 3.

[0132] 3.4. Evaluation Methods 3.4.1. Polishing Rate Evaluation Using the composition for chemical mechanical polishing prepared above, a wafer with a 12-inch molybdenum film of 5000 Å was used as the object to be polished, and a chemical mechanical polishing test was conducted under the following conditions. (Polishing conditions) · Polishing apparatus: Applied Materials, model "Reflexion-LK" · Polishing pad: Fuji Spinning Co., Ltd., "Porous polyurethane pad; H800-type1(3-1S)775" · Supply rate of the composition for chemical mechanical polishing: 300 mL / min · Platen rotation speed: 93 rpm · Head rotation speed: 90 rpm · Head pressing pressure: 2.0 psi · Polishing time: 60 seconds · Polishing rate (Å / min) = (Thickness of the film before polishing (Å) - Thickness of the film after polishing (Å)) / Polishing time (min)

[0133] The thickness of the molybdenum film was measured by the four-probe DC method using a resistivity measuring instrument (manufactured by Keysight Technologies, model "RS-100"), and calculated from this sheet resistance value and the volume resistivity of molybdenum by the following formula. Thickness of the film (Å) = (Volume resistivity of the molybdenum film (Ω·m) ÷ Sheet resistance value (Ω)) × 10 10

[0134] The evaluation criteria for the polishing rate of the molybdenum film are as follows. The evaluation results of the polishing rate of the molybdenum film are shown together in Tables 1 to 3. (Evaluation criteria) A: The polishing rate of the molybdenum film was 150 Å / min or more, and it was judged to be very good. B: The polishing rate of the molybdenum film was 100 Å / min or more and less than 150 Å / min, and it was judged to be good. C: The polishing rate of the molybdenum film was less than 100 Å / min, and it was judged to be defective and not suitable for practical use.

[0135] 3.4.2. Evaluation of etching rate The composition for chemical mechanical polishing prepared above was heated to 60°C, and a wafer piece with a 200-nm molybdenum film cut into 30 mm × 10 mm was immersed for 10 minutes. Then, the wafer piece was taken out and washed with running water, and the thickness of the molybdenum film was measured by the same method as in the above "3.4.1. Polishing Rate Evaluation". And the etching rate was calculated from the change in the thickness of the molybdenum film before and after immersion by the following formula. Etching rate of molybdenum film (Å / min) = (Thickness of molybdenum film before etching (Å) - Thickness of molybdenum film after etching (Å)) / Etching time (min)

[0136] The evaluation criteria for the etching rate of the molybdenum film are as follows. The evaluation results of the etching rate of the molybdenum film are shown together in Tables 1 to 3. (Evaluation Criteria) A: The etching rate is less than 1 Å / min, and it was judged to be very good. B: The etching rate is 1 Å / min or more and less than 4 Å / min, and it was judged to be good. C: The etching rate is 4 Å / min or more, and it was judged to be defective and not suitable for practical use.

[0137] 3.4.3. Stability Evaluation Generally, after polishing using a composition for chemical mechanical polishing containing abrasive grains, the polished surface is washed with a cleaning agent. This cleaning agent contains a water-soluble polymer such as polyacrylic acid in order to enhance the removal effect of the abrasive grains. Therefore, in the cleaning process, the composition for chemical mechanical polishing remaining on the polished surface is mixed with the water-soluble polymer, which may cause the abrasive grains to aggregate and generate coarse particles, or the water-soluble polymer may be mixed with the composition for chemical mechanical polishing and precipitate and remain on the polished surface. Even if cleaning is performed after the polishing process, it may not be possible to obtain a clean polished surface, resulting in a poor yield in semiconductor manufacturing and sometimes making it impossible to be used practically. In order to evaluate the generation of foreign substances resulting from the mixing of the cleaning agent and the composition for chemical mechanical polishing in such a cleaning process, the following model evaluation was carried out. It may not be possible, and the yield in semiconductor manufacturing may deteriorate and it may not be possible to be used practically. In order to evaluate the generation of foreign substances resulting from the mixing of the cleaning agent and the composition for chemical mechanical polishing in such a cleaning process, the following model evaluation was carried out.

[0138] To the composition for chemical mechanical polishing prepared above, polyacrylic acid (manufactured by Toagosei Co., Ltd., product name: Aron A-30SL, Mw 3000) was added to a concentration of 0.01% to prepare a test composition. After storing this test composition in a constant temperature storage at 20°C for 1 day, the test composition was evaluated using a particle size distribution measuring device (manufactured by Malvern, model "Zetasizer Ultra"), and the average secondary particle size based on the scattered light intensity of the particles contained in the test composition was measured. The particle size change rate was calculated by the following formula. Particle size change rate (%) = (Average secondary particle size (Å) obtained by measuring the test composition after storing in a constant temperature storage at 20°C for 1 day) / (Average secondary particle size (Å) obtained by measuring the composition for chemical mechanical polishing) × 100

[0139] The evaluation criteria for stability are as follows. The evaluation results are shown together in Tables 1 to 3. (Evaluation criteria) A: The particle size change rate was 95% or more and 105% or less, no foreign matter was generated, and it was judged to be very good. B: The particle size change rate was more than 105% and 150% or less, the generation of foreign matter was very small, and it was judged to be good because it could be used in practice. C: The particle size change rate was more than 150%, or precipitation was visually confirmed, the generation of foreign matter such as coarse particles was recognized, and it was judged to be poor because it was difficult to use in practice.

[0140] 3.5. Evaluation results The following Tables 1 to 3 show the composition of the composition for chemical mechanical polishing used in each example and each comparative example and each evaluation result.

[0141]

Table 1

[0142]

Table 2

[0143]

Table 3

[0144] For each component in Table 1 to Table 3 above, the following products or reagents were used respectively. <(C) component> · Iron(III) nitrate nonahydrate: manufactured by Fujifilm Wako Pure Chemical Corporation, product name "Iron(III) nitrate nonahydrate" <(D) component> · Hydrogen peroxide: manufactured by Fujifilm Wako Pure Chemical Corporation, 30% aqueous solution <(E) component> · EDTA: manufactured by Tokyo Chemical Industry Co., Ltd., ethylenediaminetetraacetic acid, product name "Ethylenediaminetetraacetic Acid" · Dimethyldodecylamine: manufactured by Tokyo Chemical Industry Co., Ltd., product name "N,N-Dimethyldodecylamine" · Dodecylamine: manufactured by Fujifilm Wako Pure Chemical Corporation · Levon S: manufactured by Sanyo Chemical Industries, Ltd., N-(2-{[2-(dodecylamino)ethyl]amino}ethyl)glycine, product name "Levon S" · 2,6,10-Trimethyl-2,6,10-triazaundecane: manufactured by Tokyo Chemical Industry Co., Ltd., product name "2,6,10-Trimethyl-2,6,10-triazaundecane"

[0145] According to the chemical mechanical polishing compositions of Examples 1 to 15, since the polishing rate of the molybdenum film is sufficiently high, it can be seen that the molybdenum film can be polished at high speed. Also, according to the chemical mechanical polishing compositions of Examples 1 to 15, it can be seen that excessive corrosion of molybdenum is suppressed by the adsorption of the (B) component on the surface of the molybdenum film.

[0146] On the other hand, according to the chemical mechanical polishing composition of Comparative Example 1, it can be seen that when the pH is greater than 5, etching on the molybdenum surface cannot be effectively suppressed. According to the chemical polishing compositions of Comparative Examples 2 to 6, since they do not contain the (B) component, it can be seen that the performance of polishing rate, etching suppression, and stability cannot be expressed in a well-balanced manner, and it is difficult to use in practice.

[0147] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiments (for example, a configuration having the same functions, methods, and results, or a configuration having the same objectives and effects). Further, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiments is replaced. Further, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiments or a configuration that can achieve the same objective. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiments.

Explanation of Reference Numerals

[0148] 10... Substrate, 12... Silicon oxide film, 14... Contact hole, 16... Molybdenum film, 42... Slurry supply nozzle, 44... Slurry (composition for chemical mechanical polishing), 46... Polishing pad, 48... Turntable, 50... Semiconductor substrate, 52... Carrier head, 54... Water supply nozzle, 56... Dressing tool, 100... Object to be processed, 200... Chemical mechanical polishing apparatus

Claims

1. (A) abrasive grains, (B) a compound represented by the following general formula (1), (F) a liquid medium, and containing, a chemical mechanical polishing composition having a pH of 1 or more and 5 or less. 【Chemical Formula 1】 (In formula (1), R １ , R ２ , R ４ , and R ６ each independently represent a hydrogen atom, an alkyl group, or an organic group having 1 to 3 carbon atoms with a hydroxy group or a carboxy group, and R ３ and R ７ each independently represent an alkanediyl group, and R ５ represents an alkyl group having 8 or more carbon atoms.)

2. The chemical mechanical polishing composition according to claim 1, further containing at least one selected from the group consisting of (C) an iron (III) compound and (D) an oxidizing agent.

3. The chemical mechanical polishing composition according to claim 1, further containing (C) an iron (III) compound and (E) a compound having 1 to 3 functional groups selected from the group consisting of an amino group and its salts.

4. The chemical mechanical polishing composition according to claim 1, wherein the average secondary particle diameter of the component (A) is 10 nm to 120 nm.

5. The chemical mechanical polishing composition according to claim 1, wherein the content of the component (A) is 0.1% by mass to 5% by mass when the total mass of the chemical mechanical polishing composition is 100% by mass.

6. The chemical mechanical polishing composition according to claim 1, which is used for polishing a surface to be polished having a molybdenum film.

7. A polishing method, comprising a step of polishing a surface to be polished having a molybdenum film using the chemical mechanical polishing composition according to any one of claims 1 to 6.

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