Polishing additive and polishing composition containing the same

Abstract

(Problem) To provide a polishing additive capable of increasing the polishing selectivity of a metal film on an insulating film, and a polishing composition comprising said polishing additive. (Solution) A polishing additive comprising at least one selected from polyether-based amine compounds represented by formulas (1) and (2). Equation (1): [Chemical Formula 1] (In formula (1), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles of oxyalkylene groups from 1 to 60, n is from 1 to 4, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms) Formula (2): [Chemical Formula 2] (In formula (2), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles added to the oxyalkylene group, ranging from 1 to 60, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms)

Description

Technology Field

[0001] The present invention relates to a polishing additive and a polishing composition containing the same, and in particular to a polishing additive and a polishing composition applicable to chemical mechanical polishing (CMP). Background Technology

[0002] In the development of semiconductor devices, such as semiconductor integrated circuits, high density and high integration through the miniaturization and stacking of wiring are required due to miniaturization and high speed. Various technologies, such as CMP, have been used for this purpose. This CMP is an essential technology for surface planarization of films to be processed, such as interlayer insulating films, plug formation, and metal wiring formation, and it performs the smoothing of the substrate.

[0003] One method for forming metal wiring is the damascene method. In the damascene method, grooves of the wiring pattern are formed in an insulating film, a metal film is inserted, and the wiring is formed by removing unnecessary parts of the inserted metal film using CMP.

[0004] As metal wiring formed by the damascene process, aluminum was previously mainly used, but now that wiring has become more miniaturized, copper, which has lower resistance, is being used.

[0005] In the polishing composition used in the damascene method, a high polishing rate of the metal film is required to efficiently remove the metal film. On the other hand, if the insulating film that appears after the metal film is removed is polished and becomes excessively thin, there is concern about a decrease in insulating properties. Therefore, in such a polishing composition, it is required that the polishing rate of the metal film be high and the polishing rate of the insulating film be low, that is, that the polishing selectivity of the metal film for the insulating film be high.

[0006] Accordingly, Patent Document 1 reports that a metal film can be polished with high selectivity toward an insulating film by using a polishing composition containing silica abrasive particles controlled to a predetermined particle size. Prior art literature

[0007] Japanese Patent Publication No. 2023-90715 The problem to be solved

[0008] However, in cases where wiring has been further refined due to the recent miniaturization and high-speed increase of semiconductor devices, the selectivity of the above polishing composition was insufficient.

[0009] Furthermore, in the polishing of metal films, high polishing speeds are generally achieved by including oxidizers or metal dissolving agents in the polishing composition to dissolve the metal while polishing. On the other hand, additives that protect the polishing surface are used to suppress the polishing of the insulating film; however, there was a concern that if these additives inhibited the dissolution of the metal, the polishing speed of the metal film would also decrease. Therefore, there is a need for a polishing additive capable of increasing the polishing selectivity of the metal film relative to the insulating film by promoting the dissolution of the metal while suppressing the polishing of the insulating film.

[0010] The present invention has been made in consideration of the circumstances described above, and the problem to be solved is to provide a polishing additive capable of increasing the polishing selectivity of a metal film with respect to an insulating film, and a polishing composition comprising said polishing additive. means of solving the problem

[0011] The inventors, after careful consideration to solve the above problem, found that the problem can be solved by using a polyether-based amine compound having a specific structure. That is, the present invention relates to [1] and [2] below.

[0012] [1] A polishing additive comprising at least one selected from polyether-based amine compounds represented by the following formulas (1) and (2).

[0013] Equation (1):

[0014] [Chemical Formula 1]

[0015]

[0016] (In formula (1), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles of oxyalkylene groups from 1 to 60, n is from 1 to 4, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms)

[0017] Formula (2):

[0018] [Chemical Formula 2]

[0019]

[0020] (In formula (2), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles added to the oxyalkylene group, ranging from 1 to 60, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms)

[0021] [2] A polishing composition comprising the polishing additive and abrasive particles described in the preceding paragraph [1], wherein the polishing composition comprises 0.1 to 10 mass% of abrasive particles and 0.01 to 10 mass% of the polyether-based amine compound. Effects of the invention

[0022] According to the present invention, a polishing additive capable of increasing the polishing selectivity of a metal film for an insulating film and a polishing composition comprising said polishing additive can be provided. Specific details for implementing the invention

[0023] Hereinafter, embodiments of the present invention will be described sequentially.

[0024] (Abrasive additive)

[0025] The polishing additive according to an embodiment of the present invention is composed of at least one selected from polyether-based amine compounds represented by the following formulas (1) and (2). That is, the polishing additive may be at least one selected from polyether-based amine compounds represented by the following formulas (1) and (2), or it may be a composition comprising this and other components described later.

[0026] Equation (1):

[0027] [Chemical Formula 3]

[0028]

[0029] (In formula (1), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles of oxyalkylene groups from 1 to 60, n is from 1 to 4, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms)

[0030] Formula (2):

[0031] [Chemical Formula 4]

[0032]

[0033] (In formula (2), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles added to the oxyalkylene group, ranging from 1 to 60, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms)

[0034] The structure of equations (1) and (2) is explained in detail as follows.

[0035] In formulas (1) and (2), AO is an oxyalkylene group having 2 to 4 carbon atoms, and the form of AO may be a straight chain or a branched form. Also, AO may be one type or two or more types, and if AO is two or more types, the addition form may be a random form or a block form, but a block form is preferred.

[0036] Examples of AO include oxyethylene groups (EO), oxypropylene groups (PO), and oxybutylene groups (BO). Among these, it is preferable to use one or more selected from oxyethylene groups, oxypropylene groups, and oxybutylene groups, and it is more preferable to use oxyethylene groups and oxypropylene groups, and a diblock structure formed by blocks of oxyethylene groups and blocks of oxypropylene groups is more preferable. When having the above diblock structure, it is preferable that blocks of oxyethylene groups are bonded to N in formulas (1) and (2), and blocks of oxypropylene groups are bonded to R in formulas (1) and (2).

[0037] When using a combination of two or more types of AO, the ratio can be appropriately determined depending on the type of AO, etc. For example, when combining EO and PO, the compositional ratio of EO and PO in mole fraction (mol%) is preferably EO:PO = 10:90 to 90:10, more preferably 20:80 to 80:20, and more preferably 30:70 to 70:30. In addition, when combining EO and BO, the compositional ratio of EO and BO in mole fraction (mol%) is preferably EO:BO = 70:30 to 95:5, and more preferably 80:20 to 90:10.

[0038] In formulas (1) and (2), m is the average number of moles of oxyalkylene groups added, ranging from 1 to 60. m can be appropriately set according to the type of AO, but is preferably 5 to 40, more preferably 10 to 30, and even more preferably 15 to 20.

[0039] In formula (1), n ​​is a number from 1 to 4, preferably 2 to 3, and particularly preferably 2.

[0040] In formulas (1) and (2), each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. Examples of hydrocarbon groups include saturated hydrocarbon groups such as methyl, ethyl, propyl, and butyl groups, and unsaturated hydrocarbon groups such as allyl and metallyl groups. Among these, preferably, it is a hydrogen atom or a saturated hydrocarbon group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. If the number of carbon atoms of the hydrocarbon group represented by R exceeds 4, there is a risk that it will be difficult to manufacture.

[0041] In equations (1) and (2), each R may be the same or arbitrarily different. Also, when R is a hydrocarbon group, they may all be the same hydrocarbon group or two or more different hydrocarbon groups.

[0042] The molecular weight of the polyether-based amine compounds represented by formulas (1) and (2) is not particularly limited, but from the perspective of polishing selectivity, it is preferably 300 to 10,000, more preferably 500 to 9,000, and more preferably 4,000 to 8,000. In addition, the above molecular weight is a value calculated from the amine value. The amine value can be measured by the method described in the column of the examples described later.

[0043] The polyether-based amine compound represented by formula (1) can be synthesized, for example, as follows.

[0044] A polyether-based compound in which R in formula (1) is a hydrogen atom can be prepared by adding an alkylene oxide to a polyethylene polyamine having 2 to 5 nitrogen atoms. In addition, when multiple types of alkylene oxides are used, the structure of AO in formula (1) can be controlled, for example, by adjusting the order of addition of the alkylene oxides.

[0045] The addition reaction of alkylene oxide may or may not use a catalyst. Alkaline catalysts are suitable for use in the addition reaction of alkylene oxide, for example, oxides of alkali metals or alkaline earth metals, hydroxides of alkali metals or alkaline earth metals, alcoholates, alkylamines such as triethylamine, and alkanolamines such as triethanolamine may be used. In addition to the alkaline catalysts mentioned above, Lewis acid catalysts such as boron trifluoride or tin tetrachloride may be used. The amount of catalyst used is generally 0.01 to 5.0 mass% relative to the mass after the completion of the addition reaction.

[0046] More specifically, the addition reaction of alkylene oxide can be carried out by adding the desired alkylene oxide to the desired polyethylene polyamine raw material under continuous pressure, for example, at 50 to 200 degrees and 0.02 to 1.0 MPa in an inert gas atmosphere such as argon or nitrogen gas, in the presence of a catalyst if necessary (unless otherwise specified in the present invention, the unit of temperature is Celsius).

[0047] A polyether compound in which R in formula (1) is a hydrocarbon group having 1 to 4 carbon atoms can be prepared by adding an alkylene oxide to a polyethylene polyamine having 2 to 5 nitrogen atoms, and then reacting a halogenated hydrocarbon such as an alkyl halide or an alkenyl halide having 1 to 4 carbon atoms in the presence of an alkali catalyst as needed, thereby alkyletherifying or alkenyletherifying the hydroxyl terminal of the oxyalkylene group.

[0048] Examples of alkyl halides include methyl chloride, ethyl chloride, propyl chloride, butyl chloride, methyl bromide, ethyl bromide, methyl iodide, and ethyl iodide, and examples of alkenyl halides include allyl chloride and metallyl chloride.

[0049] As alkali catalysts applicable when reacting halogenated hydrocarbons, oxides of alkali metals or alkaline earth metals, hydroxides of alkali metals or alkaline earth metals, alcoholates, etc., can be used.

[0050] The amount of halogenated hydrocarbon added is usually 100 to 400 mol% relative to the reacting hydroxyl groups, and the amount of alkali catalyst added is usually 100 to 500 mol% relative to the reacting hydroxyl groups. In addition, the reaction is generally carried out at a reaction temperature of 60 to 180 degrees.

[0051] The polyether-based amine compound represented by formula (2) can be synthesized, for example, as follows.

[0052] A polyether compound in which R in formula (2) is a hydrogen atom can be prepared by adding an alkylene oxide to aminoethylpiperazine. In addition, when multiple types of alkylene oxide are used, the structure of AO in formula (2) can be controlled by adjusting the order of addition of the alkylene oxides. In addition, the conditions can be the same as those for the polyether amine compound of formula (1) above.

[0053] A polyether compound in which R in formula (2) is a hydrocarbon group having 1 to 4 carbon atoms can be prepared by adding an alkylene oxide to aminoethylpiperazine, and then reacting a halogenated hydrocarbon, such as an alkyl halide or alkenyl halide having 1 to 4 carbon atoms, in the presence of an alkali catalyst as needed, thereby alkyletherifying or alkenyletherifying the hydroxyl terminal of the oxyalkylene group. In addition, the conditions can be the same as those for the polyether amine compound of formula (1) above.

[0054] The polishing additive according to the embodiment of the present invention may include, in addition to the polyether-based amine compound represented by Formula (1) or Formula (2) above, other components as needed within a range that does not impair the effects of the present invention. Examples of other components include acids, solvents, etc. Acids are used as needed for the purpose of neutralizing the polyether-based amine compound. The applicable acid may be either an organic acid or an inorganic acid, and one or more selected from organic acids and inorganic acids may be used.

[0055] Examples of organic acids include acetic acid, glycolic acid, oxalic acid, citric acid, lactic acid, and malic acid. Examples of inorganic acids include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid.

[0056] The type of solvent can be appropriately selected depending on the polishing target, etc. In the case of CMP, water such as ion-exchanged water or ultrapure water is preferred.

[0057] (Abrasive composition)

[0058] The polishing composition according to an embodiment of the present invention comprises the above-mentioned polishing additive and abrasive particles. The content of the polishing additive is 0.01 to 10 mass% as the above-mentioned polyether-based amine compound in the polishing composition. The content of the abrasive particles is 0.1 to 10 mass% in the polishing composition.

[0059] The abrasive particles available for use can be appropriately selected depending on the polishing target. For example, in the case of CMP applications, abrasive particles generally used in CMP can be appropriately selected depending on the polishing target, such as particles of alumina, ceria (cerium oxide), colloidal silica, and manganese oxide. The size of the abrasive particles can be a size generally used in this technical field, such as those with an average particle size of 10 to 1,000 nm, which can be appropriately selected depending on the application.

[0060] The polishing composition according to an embodiment of the present invention may further include other components in addition to the polishing additive and abrasive particles described above, to the extent that the function of each component is not impaired. Examples of such other components include a dispersion medium, a dispersant, a pH adjuster, a surfactant, an antifoaming agent, an oxidizing agent, an organic acid, an anti-corrosion agent, etc.

[0061] The available dispersion medium can be appropriately selected depending on the application, etc. For example, aqueous solvents and organic solvents may be used. Examples of aqueous solvents include water, such as ion-exchanged water and ultrapure water. Examples of organic solvents include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, glycol ether solvents, terpene solvents, and alcohol solvents. For CMP applications, aqueous solvents are preferred, and water is more preferred. The content of the dispersion medium is preferably 75 to 99.8 mass% in the polishing composition. In addition, if a solvent is included in the polishing additive, the total amount is taken as the sum of the two.

[0062] As for the dispersant, a general type capable of dispersing abrasive particles within the polishing composition can be appropriately selected depending on the type of abrasive particles. Examples include anionic dispersants, nonionic dispersants, cationic dispersants, and amphoteric dispersants. Furthermore, for CMP applications, water-soluble dispersants are preferred.

[0063] Specific examples of dispersants include, for instance, phosphate compounds; hydrogen phosphate compounds; homopolymers of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid (polyacrylic acid, etc.); ammonium salts or amine salts of said polymers; copolymers of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid with monomers such as alkyl acrylate (methyl acrylate, ethyl acrylate, etc.), hydroxyalkyl acrylate (hydroxyethyl acrylate, etc.), alkyl methacrylate (methyl methacrylate, ethyl methacrylate, etc.), hydroxyalkyl methacrylate (hydroxyethyl methacrylate, etc.), vinyl acetate, vinyl alcohol, etc. (copolymers of acrylic acid and alkyl acrylate, etc.); and ammonium salts or amine salts of said copolymers.

[0064] It is acceptable to use a single type of dispersant, or to use a combination of two or more types.

[0065] The content of the dispersant is preferably 0.1 to 10 parts by mass as solid content per 100 parts by mass of abrasive particles.

[0066] As for the oxidizing agent, it can be appropriately selected depending on the object to be polished; examples include ammonium persulfate, potassium persulfate, hydrogen peroxide, ferric nitrate, and cerium ammonium nitrate. These may be used individually or in combination of two or more types. The content of the oxidizing agent is preferably 0.01 to 5 mass% in the polishing composition.

[0067] As for the organic acid, one having an oxidation-inhibiting effect may be used. Examples of organic acids having this function include quinaldic acid, quinolinic acid, malonic acid, oxalic acid, succinic acid, etc. The content of the organic acid in the polishing composition is preferably 0.01 to 5 mass%.

[0068] The properties of the abrasive composition can be appropriately adjusted by the composition of the components contained therein, taking into account the application, etc. Generally, it is a slurry.

[0069] The abrasive composition according to the embodiment can be prepared by known methods. For example, a method may be used in which the above-mentioned abrasive particles and abrasive additives, and other components added as needed, are added to a container and then dispersed at room temperature. There is no particular limitation on the order of addition of each component. Known dispersers may be used as the dispersion apparatus for the dispersion treatment. Examples include a roll mill, a ball mill, a beads mill, a sand mill, a homogenizer, a disperser, and a self-rotating mixer. In addition, the dispersion treatment may be performed in an ultrasonic generating bath.

[0070] The polishing composition described above can be widely used as a polishing slurry for CMP. In particular, because it contains the polishing additive described above, it is preferred for polishing slurries for polishing insulating materials, metal materials, and various substrates composed of these materials.

[0071] Examples of applicable insulating materials include silicon-based insulating materials and organic polymer-based insulating materials. Examples of silicon-based insulating materials include silicon oxide and silicon nitride. Examples of applicable metal materials include aluminum, copper, tungsten, cobalt, and ruthenium, and copper is particularly preferred.

[0072] Examples of applicable substrates include substrates used in a wiring formation process by the damascene method. Specifically, examples include a substrate comprising an insulating material and a metal material installed on the insulating material. The polishing composition is preferred as a polishing slurry used in a wiring formation process by the damascene method because it provides good polishing selectivity of the metal film toward the insulating film by including the polishing additive above.

[0073] (Example)

[0074] The embodiments of the present invention will be described in more detail below based on the examples.

[0075] (Measurement of amine value)

[0076] The method for measuring the amine value of polyether compounds 1 to 8 synthesized in the following Examples 1 to 8 is as follows.

[0077] Each sample of polyether compounds 1 to 8 was weighed into a beaker, and neutral ethanol (ethyl alcohol (99.5 V / V%), neutralized with N / 2 standard hydrochloric acid solution using bromocresol green indicator immediately before use) was added to dissolve it. Next, a few drops of bromocresol green indicator were added, and the solution was titrated with N / 2 standard hydrochloric acid solution, with the endpoint set when the green color of the solution turned yellow. The amine value was calculated from the following formula.

[0078] Amine value = (28.05×F×A) / W

[0079] However, A: Amount of N / 2 hydrochloric acid standard solution (mL), F: Factor of N / 2 hydrochloric acid standard solution, W: Sample amount (g)

[0080] (Example 1: Synthesis of Polyether-based Amine Compound 1)

[0081] 103.2 g (1 mol) of diethylenetriamine (product name: DETA, manufactured by Tosoh) was added to a 5-liter stainless steel pressure vessel equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the system was replaced with nitrogen gas. After raising the temperature to 120°C under stirring, 220.3 g (5 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas, under conditions of 120°C and 0.05–0.50 MPa (gauge pressure). After the addition was completed, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40°C, 11.8g of potassium hydroxide was added, and the system was replaced with nitrogen gas. Subsequently, 1431.6g (32.5mol) of ethylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. Subsequently, 2178.8g (37.5mol) of propylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. After cooling to 30°C, the reaction product was removed from the pressure vessel, neutralized with hydrochloric acid to a pH of 9 to 10, subjected to reduced pressure treatment at 100°C for 1 hour to remove contained moisture, and finally, the salt was removed by filtration to obtain polyether-based amine compound 1. The amine number of the obtained polyether-based compound 1 was 35.1, and the molecular weight calculated from the amine number was 4,796.

[0082] (Example 2: Synthesis of Polyether-based Amine Compound 2)

[0083] 103.2 g (1 mol) of diethylenetriamine (product name: DETA, manufactured by Dosho Co., Ltd.) was added to a stainless steel pressure vessel with a capacity of 5 liters equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the inside of the system was replaced with nitrogen gas. After raising the temperature to 120 degrees under stirring, 220.3 g (5 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas under conditions of 120 degrees and 0.05 to 0.50 MPa (gauge pressure). After the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40 degrees, 10.2 g of potassium hydroxide was added, and the inside of the system was replaced with nitrogen gas. Continuing, 3083.5 g (70 mol) of ethylene oxide was added according to the above method, and after the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 30 degrees, the reaction product was removed from the pressure vessel and neutralized with hydrochloric acid to a pH of 9 to 10. To remove the contained moisture, a reduced pressure treatment was performed at 100 degrees for 1 hour, and finally, the salt was removed by filtration to obtain polyether-based amine compound 2. The amine number of the obtained polyether-based compound 2 was 45.0, and the molecular weight calculated from the amine number was 3,740.

[0084] (Example 3: Synthesis of Polyether-based Amine Compound 3)

[0085] 51.6 g (0.5 mol) of diethylenetriamine (product name: DETA, manufactured by Dosho Co., Ltd.) was added to a stainless steel pressure vessel with a capacity of 5 liters equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the inside of the system was replaced with nitrogen gas. After raising the temperature to 120 degrees under stirring, 110.1 g (2.5 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas under conditions of 120 degrees and 0.05 to 0.50 MPa (gauge pressure). After the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40 degrees, 9.7 g of potassium hydroxide was added, and the inside of the system was replaced with nitrogen gas. Next, 1266.4 g (28.8 mol) of ethylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. Next, 1815.6 g (31.3 mol) of propylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. After cooling to 30 degrees, the reaction product was removed from the pressure vessel, neutralized with hydrochloric acid to a pH of 9 to 10, subjected to reduced pressure treatment at 100 degrees for 1 hour to remove the contained moisture, and finally, the salt was removed by filtration to obtain polyether-based amine compound 3. The amine number of the obtained polyether-based compound 3 was 21.1, and the molecular weight calculated from the amine number was 7,978.

[0086] (Example 4: Synthesis of Polyether-based Amine Compound 4)

[0087] 309.5 g (3 mol) of diethylenetriamine (product name: DETA, manufactured by Doso Co., Ltd.) was added to a 5-liter stainless steel pressure vessel equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the system was purged with nitrogen gas. After raising the temperature to 120°C under stirring, 3303.8 g (75 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas, under conditions of 120°C and 0.05–0.50 MPa (gauge pressure). After the addition was completed, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 30 degrees, the reaction product was removed from a pressure vessel and neutralized with hydrochloric acid to a pH of 9 to 10. To remove the contained moisture, reduced pressure treatment was performed at 100 degrees for 1 hour, and finally, the salt was removed by filtration to obtain polyether-based amine compound 4. The amine number of the obtained polyether-based compound 4 was 227, and the molecular weight calculated from the amine number was 742.

[0088] (Example 5: Synthesis of Polyether-based Amine Compound 5)

[0089] 117.0 g (0.8 mol) of triethylenetetramine (product name: TETA, manufactured by Dosho Co., Ltd.) was added to a 5-liter stainless steel pressure vessel equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the inside of the system was replaced with nitrogen gas. After raising the temperature to 120 degrees under stirring, 211.4 g (4.8 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas under conditions of 120 degrees and 0.05 to 0.50 MPa (gauge pressure). After the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40 degrees, 11.4 g of potassium hydroxide was added, and the inside of the system was replaced with nitrogen gas. Next, 1374.4 g (31.2 mol) of ethylene oxide was added according to the above method, and after the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. Next, 2091.6 g (36 mol) of propylene oxide was added according to the above method, and after the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 30 degrees, the reaction product was removed from the pressure vessel, neutralized with hydrochloric acid to a pH of 9 to 10, subjected to reduced pressure treatment at 100 degrees for 1 hour to remove the contained moisture, and finally, the salt was removed by filtration to obtain polyether-based amine compound 5. The amine number of the obtained polyether-based compound 5 was 47.3, and the molecular weight calculated from the amine number was 4,743.

[0090] (Example 6: Synthesis of Polyether-based Amine Compound 6)

[0091] 193.8 g (1.5 mol) of 2-aminoethylpiperazine (product of Tokyo Chemical Industry; TCI) was added to a stainless steel pressure vessel with a capacity of 5 liters equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the system was replaced with nitrogen gas. After raising the temperature to 120 degrees under stirring, 198.2 g (4.5 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas under conditions of 120 degrees and 0.05 to 0.50 MPa (gauge pressure). After the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40 degrees, 10.9 g of potassium hydroxide was added, and the system was replaced with nitrogen gas. Next, 1288.5 g (29.3 mol) of ethylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. Next, 1960.9 g (33.8 mol) of propylene oxide was added according to the above method, and the reaction was carried out under the same conditions until the internal pressure became constant after the addition was finished. After cooling to 30 degrees, the reaction product was removed from the pressure vessel, neutralized with hydrochloric acid to a pH of 9 to 10, subjected to reduced pressure treatment at 100 degrees for 1 hour to remove the contained moisture, and finally, the salt was removed by filtration to obtain polyether-based amine compound 6. The amine number of the obtained polyether-based compound 6 was 69.3, and the molecular weight calculated from the amine number was 2,428.

[0092] (Example 7: Synthesis of Polyether-based Amine Compound 7)

[0093] 479.6 g (0.1 mol) of polyether-based amine compound 1 and 100.7 g of potassium hydroxide were introduced into a 5-liter stainless steel pressure vessel equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the system was purged with nitrogen gas. Under stirring, 40.3 g of methyl chloride was injected at 80–130°C and reacted until the internal pressure became constant. After cooling to 30°C, the reaction product was removed from the pressure vessel and neutralized with hydrochloric acid to a pH of 9–10. To remove the contained moisture, a reduced pressure treatment was performed at 100°C for 1 hour, and finally, the salt was removed by filtration to obtain polyether-based amine compound 7. The amine number of the obtained polyether compound 7 was 34.5, and the molecular weight obtained from the amine number was 4,879.

[0094] (Example 8: Synthesis of Polyether-based Amine Compound 8)

[0095] 103.2 g (1 mol) of diethylenetriamine (product name: DETA, manufactured by Dosho Co., Ltd.) was added to a stainless steel pressure vessel with a capacity of 5 liters equipped with a stirrer, pressure gauge, thermometer, safety valve, gas injection pipe, exhaust pipe, cooling coil, and steam jacket, and the inside of the system was replaced with nitrogen gas. After raising the temperature to 120 degrees under stirring, 220.3 g (5 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas injection pipe while pressurizing with nitrogen gas under conditions of 120 degrees and 0.05 to 0.50 MPa (gauge pressure). After the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 40 degrees, 11.8 g of potassium hydroxide was added, and the inside of the system was replaced with nitrogen gas. Next, 2532.9 g (57.5 mol) of ethylene oxide was added according to the above method, and after the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. Next, 901.4 g (12.5 mol) of butylene oxide was added according to the above method, and after the addition was finished, the reaction was carried out under the same conditions until the internal pressure became constant. After cooling to 30 degrees, the reaction product was removed from the pressure vessel, neutralized with hydrochloric acid to a pH of 9 to 10, subjected to reduced pressure treatment at 100 degrees for 1 hour to remove the contained moisture, and finally, the salt was removed by filtration to obtain polyether-based amine compound 8. The amine number of the obtained polyether-based compound 8 was 41.2, and the molecular weight calculated from the amine number was 4,086.

[0096] The composition of polyether-based amine compounds 1 to 8 obtained in Examples 1 to 8 is shown in Table 1.

[0097] [Table 1]

[0098]

[0099] (Comparative Example 1)

[0100] Polyethylene glycol (molecular weight 2000) was used instead of a polyether-based amine compound.

[0101] (Comparative Example 2)

[0102] Diethylenetriamine (product name: DETA, manufactured by Doso Co., Ltd.) was used instead of polyether-based amine compounds.

[0103] (Copper leaching assessment)

[0104] <Preparation of Solution for Elution Test>

[0105] 0.3 mass% hydrogen peroxide, 0.1 mass% malonic acid, 0.1 mass% polyether-based amine compounds of Examples 1 to 8 or compounds of Comparative Examples 1 and 2 as polishing additives, and the remainder being ion-exchanged water were mixed. For each of the obtained solutions, the pH was adjusted to 2 ± 0.5 with nitric acid to prepare solutions 1 to 10 for the elution test. In addition, since polishing was not performed, abrasive particles were not added to the solutions for the elution test. Table 2 shows the composition of solutions 1 to 10.

[0106] [Table 2]

[0107]

[0108] <Dissolution Test>

[0109] Copper plates cut to 1×2 cm were immersed in solutions 1 to 10 for the leaching test and left to stand at room temperature for 2 hours, after which the copper plates were removed and washed. Before and after immersion, the weight of the copper plates was measured using a micro electronic balance BM-20 (manufactured by A&D Company). The amount of copper leached was calculated from the following formula.

[0110] Copper leaching amount (wt%) = [[Weight of copper plate before immersion (g) - Weight of copper plate after immersion (g)] / Weight of copper plate before immersion (g)] × 100

[0111] The amount of copper leaching was evaluated according to the following criteria.

[0112] ◎: Dissolution amount 0.9 wt% or more

[0113] ○: Dissolution amount 0.6wt% or more and less than 0.9wt%

[0114] ×: Dissolution amount less than 0.6 wt%

[0115] (Grinding evaluation)

[0116] <Preparation of Slurry for Grinding Evaluation>

[0117] Ultrapure water was added to a colloidal silica abrasive (Compol 80, manufactured by Musashino Denshi Co., Ltd., solvent: water) to adjust the powder (silica abrasive particles) concentration to 5 mass%, and a polishing evaluation slurry was prepared by adding the polyether-based amine compounds of Examples 1 to 8 or the compounds of Comparative Examples 1 and 2 as polishing additives to the polishing evaluation slurry (polishing composition) to a concentration of 0.1 mass%.

[0118] Grinding Test

[0119] A test specimen of silicon oxide film was obtained by cutting a 20mm × 20mm test specimen from a 12-inch silicon wafer having silicon oxide (SiO2) films with a thickness of 2000nm formed on both sides.

[0120] The MA-200e manufactured by Musashino Electronics Co., Ltd. was used as the polishing device. The IC1000 (manufactured by Nitta DuPont) was used as the polishing pad. The polishing pad was attached to the platen of the polishing device, the test specimen was set in the polishing holder, and the polishing holder was placed on the polishing pad. Additionally, a weight was placed on the polishing holder so that the pressure applied to the test specimen was 7.5 kPa. Polishing of the test specimen was performed by dripping a polishing evaluation slurry onto the center of the polishing pad at a rate of 10 mL / min, while rotating the platen and the polishing holder in the same direction at 120 rpm / min for 5 minutes. After polishing, the specimen was washed with ultrapure water and dried with nitrogen gas.

[0121] Before and after polishing, the weight of the test specimen was measured using a micro electronic balance BM-20 (manufactured by A&D Co., Ltd.). The polishing rate of the silicon oxide film was calculated by the following formula.

[0122] Polishing rate of silicon oxide film (nm / min) = [Weight of specimen before polishing (g) - Weight of specimen after polishing (g)] / Density of silicon oxide (cm³) 3 / g) / Area of ​​the test specimen (cm²) 2 ) / Grinding time (min) / 10000000

[0123] The grinding speed was evaluated according to the following criteria.

[0124] ◎: Polishing speed less than 10 nm / min

[0125] ○: Polishing speed 10 nm / min or more and less than 15 nm / min

[0126] ×: Polishing speed is 15 nm / min or higher

[0127] The results of each evaluation are shown in Table 3. In Table 3, the column to the left of each evaluation item represents the calculated value, and the units are as described above.

[0128] [Table 3]

[0129]

[0130] From Table 3, the following points were observed.

[0131] When polyether-based amine compounds 1 to 8 obtained in Examples 1 to 8 are used as polishing additives, the amount of copper leaching is greater compared to when polyethylene glycol of Comparative Example 1 is used as a polishing additive, so polishing of the copper film can be promoted.

[0132] In addition, when polyether-based amine compounds 1 to 8 are used as polishing additives, the polishing speed of the silicon oxide film is slower compared to when diethylenetriamine of Comparative Example 2 is used as a polishing additive.

[0133] As described above, a polishing composition comprising a predetermined polyether-based amine compound as a polishing additive can promote polishing by promoting the dissolution of the metal film, and also, because the polishing speed of the insulating film is slow, it is possible to increase the polishing selectivity of the metal film toward the insulating film. For this reason, the polishing composition is preferred, for example, as a polishing slurry for CMP applications. In addition, the polishing additive is effective as a component of the polishing composition.

Claims

Claim 1 A polishing additive comprising at least one selected from polyether-based amine compounds represented by formulas (1) and (2). Formula (1): [Chemical Formula 1] (In Formula (1), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles of oxyalkylene groups from 1 to 60, n is from 1 to 4, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms) Formula (2): [Chemical Formula 2] (In formula (2), AO represents an oxyalkylene group having 2 to 4 carbon atoms, m is the average number of moles added to the oxyalkylene group, ranging from 1 to 60, and each R is independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms) Claim 2 A polishing composition comprising the polishing additive and abrasive particles described in claim 1, wherein the polishing composition comprises 0.1 to 10 mass% of abrasive particles and 0.01 to 10 mass% of the polyether-based amine compound.

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