JP2013048263A - Aqueous dispersing material for chemical mechanical polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous dispersing material for chemical mechanical polishing which allows the suppression of erosion and its speed in execution of an overpolishing process in the step of chemical mechanical polishing.SOLUTION: An aqueous dispersing material for chemical mechanical polishing according to the invention is used for a technique such that a hole or a channel formed in a dielectric film on a wafer is filled with copper or copper alloy, and then excessive part of the copper or copper alloy is removed by chemical mechanical polishing, whereby a wiring line is formed. The aqueous dispersing material comprises: fumed silica or colloidal silica; water; hydrogen peroxide; and at least one material selected from the group consisting of potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate. The total amount of the potassium dodecylbenzenesulfonate and the ammonium dodecylbenzenesulfonate is 0.002 mass% or more to less than 1 mass%, and pH falls between 7.5 and 9.0 inclusive.

Description

  The present invention relates to an aqueous dispersion for chemical mechanical polishing. More particularly, the present invention relates to an aqueous dispersion particularly useful in chemical mechanical polishing of a metal layer in a semiconductor device manufacturing process.

  With the improvement of the degree of integration of semiconductor devices and the formation of multilayer wiring, a chemical mechanical polishing technique has been introduced for polishing a film to be processed. JP-A-62-2102543, JP-A-64-55845, JP-A-5-275366, JP-A-8-510437, JP-A-8-17831, JP-A-8-197414 As disclosed in JP-A-10-44047 and the like, chemical mechanical polishing is performed after a wiring material such as tungsten, aluminum, or copper is embedded in holes or grooves formed in an insulating film on a process wafer. Thus, a method of forming wiring by removing excess wiring material is employed.

  When polishing the initial excess film thickness X (Å) when the wiring material is embedded in the groove, etc. at the polishing rate V (Å / min), the purpose should be achieved by polishing only for the time of X / V (min). However, in the actual semiconductor device manufacturing process, excessive polishing (over polishing) is performed exceeding X / V (min) in order to remove the polishing residue other than the grooves. At this time, the wiring portion may be excessively polished, resulting in a concave shape. This concave wiring shape is called erosion, and is not preferable because it reduces the yield of the semiconductor device.

JP-A-62-102543 Japanese Patent Application Laid-Open No. 64-55845 JP-A-5-275366 Japanese translation of Japanese translation of PCT publication No. 8-510437 JP-A-8-17831 Japanese Patent Laid-Open No. 8-197414 JP 10-44047 A

  The present invention solves the above-described conventional problems, and an object thereof is to provide an aqueous dispersion for chemical mechanical polishing capable of suppressing erosion during overpolishing and its speed in the chemical mechanical polishing step.

  The chemical mechanical polishing aqueous dispersion of the present invention contains abrasive grains, water, and potassium dodecylbenzenesulfonate and / or ammonium dodecylbenzenesulfonate. Hereinafter, the present invention will be described in more detail.

As abrasive grains of the present invention, inorganic particles such as silica, alumina, titania, zirconia, ceria; polyvinyl chloride, polystyrene and styrene copolymers, polyacetal, saturated polyester, polyamide, polycarbonate, polyethylene, polypropylene, poly-1 Organic particles comprising a thermoplastic resin such as a polyolefin and an olefin copolymer such as butene and poly-4-methyl-1-pentene, a (meth) acrylic resin such as phenoxy resin and polymethylmethacrylate, and an acrylic copolymer; At least one or more of the above organic / inorganic composite particles composed of organic particles and inorganic particles can be used.

  As said inorganic particle, a highly purified inorganic particle is preferable. Specifically, the fumed method in which silicon chloride, aluminum chloride, titanium chloride, etc. are reacted with oxygen and hydrogen in the gas phase, the sol-gel method in which hydrolytic condensation is performed from a metal alkoxide such as tetraethoxysilane, and the impurities are purified by purification. Examples thereof include silica, alumina, titania and the like synthesized by the removed inorganic colloid method.

  Examples of the organic particles include (1) polystyrene and styrene copolymers, (2) (meth) acrylic resins such as polymethyl methacrylate, and (meth) acrylic copolymers, (3) polyvinyl chloride, polyacetal, From saturated polyesters, polyamides, polyimides, polycarbonates, phenoxy resins, and (4) polyolefins such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and thermoplastic resins such as olefin copolymers. Can be used. These can be produced by an emulsion polymerization method, a suspension polymerization method, an emulsion dispersion method, a pulverization method or the like. In addition, divinylbenzene, ethylene glycol dimethacrylate, and the like can coexist at the time of synthesizing the polymer and can be used as a copolymer having a crosslinked structure.

  The organic / inorganic composite particles are not particularly limited as long as the organic particles and the inorganic particles are integrally formed to such an extent that they are not easily separated during polishing. The composite particles are those obtained by polycondensing alkoxysilane, aluminum alkoxide, titanium alkoxide, etc. in the presence of a polymer such as polystyrene, polymethylmethacrylate, etc., and at least the surface of the polymer particles is bonded with polysiloxane etc. Can be used. The produced polycondensate may be directly bonded to the functional group of the polymer particles, or may be bonded via a silane coupling agent or the like.

  Further, silica particles, alumina particles, or the like can be used instead of alkoxysilane or the like. These may be held in entanglement with polysiloxane or the like, or may be chemically bonded to the polymer particles by a functional group such as a hydroxyl group that they have.

  In addition, as the composite particles, an aqueous dispersion containing inorganic particles having different zeta potentials and organic particles having different signs can be used in which these particles are combined by electrostatic force. The zeta potential of organic particles is often negative over the entire pH range or a wide range excluding a low pH range, but it is more reliable by using organic particles having a carboxyl group, a sulfonic acid group, etc. Organic particles having a negative zeta potential can be obtained. Moreover, it can also be set as the organic particle which has a positive zeta potential in a specific pH range by setting it as the organic particle which has an amino group etc. On the other hand, the zeta potential of inorganic particles is highly pH-dependent and has an isoelectric point at which this potential becomes 0, and the sign of the zeta potential is reversed before and after that.

  Therefore, by combining specific inorganic particles and organic particles and mixing them in a pH range in which the zeta potential has an opposite sign, the inorganic particles and the organic particles can be combined together by electrostatic force. Further, even when the zeta potential has the same sign during mixing, the inorganic particles and the organic particles can be integrated by changing the pH and setting the zeta potential to the opposite sign.

  Further, as the organic / inorganic composite particles, alkoxysilane, aluminum alkoxide, titanium alkoxide and the like are polycondensed as described above in the presence of the particles integrally combined by electrostatic force as described above. It is also possible to use a material obtained by further combining polysiloxane or the like on the surface.

  The average particle diameter of the abrasive grains is preferably “0.005 to 3 μm”. If the average particle size is less than 0.005 μm, an aqueous dispersion having a sufficiently high polishing rate may not be obtained. On the other hand, when the average particle diameter exceeds 3 μm, the abrasive grains settle and separate, making it difficult to obtain a stable aqueous dispersion. The average particle diameter is particularly preferably 0.01 to 1.0 μm, more preferably 0.02 to 0.7 μm. An abrasive having an average particle diameter of secondary aggregates in this range can be a stable aqueous dispersion for chemical mechanical polishing that has a high polishing rate and does not cause sedimentation or separation of particles. it can. In addition, the average particle diameter of this secondary aggregate can be measured by observing with a laser scattering diffractometer or a transmission electron microscope.

  The content of the abrasive grains in the present invention can be 0.05 to 20% by mass, particularly 0.1 to 15% by mass, and further 0.1 to 10% by mass with respect to the total amount of the aqueous dispersion. It is preferable that If the content of abrasive grains is less than 0.05% by mass, the improvement in polishing performance is not sufficient. On the other hand, if the content exceeds 20% by mass, the cost increases and the stability of the aqueous dispersion decreases. Therefore, it is not preferable.

  The aqueous dispersion of the present invention contains water as the medium. If necessary, an organic solvent compatible with water, such as methanol, can be mixed and used, but it is preferable to use only water.

  The potassium dodecylbenzenesulfonate and ammonium used in the present invention can be prepared by neutralizing dodecylbenzenesulfonate with potassium hydroxide or ammonia. Content of the said potassium dodecylbenzenesulfonate and / or ammonium dodecylbenzenesulfonate can be 0.002-1 mass% with respect to the total amount of an aqueous dispersion, Preferably it is 0.005-0. 5 mass%, Furthermore, it can be set as 0.007-0.3 mass%. Moreover, both can also be used together. When the content of the surfactant exceeds 1% by mass, the polishing performance such as the polishing rate is lowered, which is not preferable. On the other hand, if it is less than 0.002% by mass, the effect of suppressing erosion is not sufficient.

  Although the aqueous dispersion of the present invention contains potassium dodecylbenzenesulfonate and / or ammonium dodecylbenzenesulfonate within the above range, it exhibits an excellent effect on erosion and the suppression of its speed. The potassium dodecyl benzene sulfonate and ammonium dodecyl benzene sulfonate used have a content of alkali metals (excluding potassium) and polyvalent metals in each metal species from the viewpoint of reducing contamination of the polished surface after polishing. It is preferably 10 ppm or less, more preferably 3 ppm or less.

  When the metal content exceeds 10 ppm, these metals may adhere to and remain on the polished wiring, which may lead to a decrease in yield due to deterioration of the electrical characteristics of the device.

  Here, the metal whose content should be limited varies depending on the type of the surface to be polished and its purpose. From the viewpoint of suppressing adverse effects on the device characteristics of the wiring after polishing, when the surface to be polished is copper, it is preferable to reduce the contents of Na, Fe, Al, Ni, and Cr. Similarly, the content of Na, Fe, Cu, Ni, Cr when the surface to be polished is aluminum, and Na, Fe, Al, Cu, Ni, Cr when the surface to be polished is tungsten. It is preferable to reduce the content of.

As a means for achieving these metal contents, an appropriate method can be adopted. For example, metals can be removed by an ion exchange method. Specifically, it is achieved by bringing dodecylbenzenesulfonic acid into contact with a cation exchange resin, sufficiently removing the impure metal content contained in dodecylbenzenesulfonic acid, and then neutralizing with potassium hydroxide or ammonia. it can. At this time, it is preferable to use commercially available high-purity potassium hydroxide and ammonia used for neutralization.

  In particular, when the content of impure metals in the raw material is large, the above-described metal content can be achieved by repeating these treatments several times.

  The impure metal content can be measured by atomic absorption analysis, total reflection X-ray fluorescence analysis, or the like.

  In addition, potassium dodecylbenzenesulfonate and / or a portion of ammonium dodecylbenzenesulfonate can be replaced with other surfactants. Examples of other surfactants that can be used at this time include cationic, anionic and nonionic surfactants. These surfactants are also preferably those in which the amount of contained metal is reduced by the above method.

  Examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts. Examples of anionic surfactants include fatty acid soaps, carboxylates such as alkyl ether carboxylates, alkylbenzene sulfonates, alkyl naphthalene sulfonates, sulfonates such as 瘁 | olefin sulfonates, higher alcohol sulfates. Examples thereof include ester salts, sulfuric acid ester salts such as alkyl ether sulfates, and phosphoric acid ester salts such as alkyl phosphoric acid esters. Examples of the nonionic surfactant include ether types such as polyoxyethylene alkyl ether, ether ester types such as glycerol ester polyoxyethylene ether, and ester types such as polyethylene glycol fatty acid ester, glycerol ester and sorbitan ester. .

  When these surfactants are used in combination, the amount used may be less than 10% by mass based on the total amount of potassium dodecylbenzenesulfonate and / or ammonium dodecylbenzenesulfonate and other surfactants. it can.

  The aqueous dispersion of the present invention can further contain an oxidizing agent. As the oxidizing agent that can be used in the present invention, an appropriate one can be selected and used according to, for example, a Pourbaix diagram depending on the electrochemical properties of the metal film that is the surface to be polished. Examples of the oxidizing agent include organic peroxides such as hydrogen peroxide, peracetic acid, perbenzoic acid, and tert-butyl hydroperoxide; permanganic acid compounds such as potassium permanganate; heavy ions such as potassium dichromate; Chromic acid compounds; halogen acid compounds such as potassium iodate; nitrate compounds such as nitric acid and iron nitrate; perhalogen compounds such as perchloric acid; persulfates such as ammonium persulfate; silicomolybdic acid, phosphotungstic acid, phosphomolybdenum Examples thereof include heteropolyacids such as acid and silicon tungsten molybdate.

  The content of the oxidizing agent can be 15% by mass or less, particularly 0.1 to 10% by mass, more preferably 0.3 to 8% by mass, when the aqueous dispersion is 100% by mass. It is preferable. If the content exceeds 15% by mass, the surface to be polished may be corroded or dangerous in handling, which may be undesirable.

  In addition to the above, the chemical mechanical polishing aqueous dispersion of the present invention may contain other additives such as organic acids, complexing agents and bases, depending on the purpose.

Examples of the organic acid include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, isoprenesulfonic acid, gluconic acid, lactic acid, citric acid, tartaric acid, malic acid, glycolic acid, malonic acid, formic acid, oxalic acid, succinic acid, fumaric acid, Examples include maleic acid and phthalic acid. Preferably, it is an organic acid having two or more carboxyl groups in one molecule. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, malic acid , Tartaric acid and citric acid. These organic acids may be used alone or in combination of two or more. These acids can be contained in an amount of 10% by mass or less, particularly 0.01 to 8% by mass, based on 100% by mass of the aqueous dispersion. If the content of the organic acid is within this range, it is preferable because it is excellent in dispersibility and can be a sufficiently stable aqueous dispersion, and the effect of suppressing etching is increased.

  As the complexing agent, a compound containing a skeleton selected from quinoline, isoquinoline, benzimidazole, benzotriazole, indole, isoindole, quinazoline, cinnoline, quinoxaline, phthalazine, and acridine is particularly preferable.

  The content of these complexing agents can be 3% by mass or less when the aqueous dispersion is 100% by mass.

  The chemical mechanical polishing aqueous dispersion of the present invention may further contain a “base” and control the pH to further improve the dispersibility, corrosion prevention, stability and polishing rate of the aqueous dispersion. This base is not particularly limited, and either an organic base or an inorganic base can be used. Examples of the organic base include ethylenediamine and ethanolamine. Examples of the inorganic base include ammonia, potassium hydroxide and the like, and only one kind of these bases may be used, or two or more kinds may be used in combination. These bases can be contained in an amount of 10% by mass or less, particularly 0.001 to 8% by mass, based on 100% by mass of the aqueous dispersion. The base content plays an important role in controlling the pH, and the preferred pH varies depending on the type of film to be polished. For example, in the case of copper, neutral or basic is better than acidic, and when polishing tungsten or aluminum, acidic is preferred. If the content of the base is in the range of 10% by mass or less, it is preferable because it is excellent in dispersibility and can be a sufficiently stable aqueous dispersion.

  As a film to be polished having a metal layer that is polished using the chemical mechanical polishing aqueous dispersion of the present invention, a pure tungsten film or a pure aluminum film provided on a semiconductor substrate in the process of manufacturing a semiconductor device such as a VLSI Alternatively, a polished surface having a film made of an alloy of tungsten, aluminum, copper, or the like and other metal may be used in addition to a pure copper film. This polished surface may contain a layer made of tantalum, titanium, tantalum nitride, titanium nitride or the like used for the barrier metal in addition to the above metal layer.

  When the chemical mechanical polishing of the surface to be polished is performed using the chemical mechanical polishing aqueous dispersion of the present invention, a commercially available chemical mechanical polishing apparatus (EPO-112, EPO-222, lap, manufactured by Ebara Seisakusho Co., Ltd.) It is possible to polish under a predetermined polishing condition using Master SFT, model “LGP-510, LGP-552”, Applied Materials “Mirra”, etc.).

  After polishing, it is preferable to remove the abrasive grains remaining on the surface to be polished. The removal of the abrasive grains can be performed by a normal cleaning method. For example, after the brush scrub cleaning, the abrasive particles adhering to the surface to be polished can be removed by cleaning with an alkaline cleaning solution of ammonia: hydrogen peroxide: water of about 1: 1: 5 (weight ratio). . Further, as the cleaning solution for the 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), or the like can be used. .

When the abrasive grains are only organic particles, the surface to be polished can be removed by burning the organic abrasive grains by increasing the temperature in the presence of oxygen. Specific methods of combustion include ashing treatment by plasma such as exposure to oxygen plasma or supply of oxygen radicals in a downflow, which makes it easy to remove residual organic abrasive grains from the surface to be polished. Can be removed.

  The chemical mechanical polishing aqueous dispersion of the present invention can suppress erosion during overpolishing and its speed, and if this is used to polish a surface to be polished having a metal layer, a highly accurate polished surface can be obtained. it can.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Preparation Example 1
Preparation of potassium dodecylbenzenesulfonate Dodecylbenzenesulfonate was added to ion-exchanged water to prepare a dodecylbenzenesulfonate solution. Thereafter, the alkali metal and polyvalent metal were sufficiently removed by passing through a column filled with a hydrogen-type strongly acidic cation exchange resin (Amberlite IR120BHAG manufactured by Organo Corporation).

  Next, an aqueous potassium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) aqueous solution was gradually added to prepare a potassium dodecylbenzenesulfonate solution having a pH of 8.

  When the concentrations of Na, Fe, Cu, Al, Ni, and Cr were measured by the atomic absorption method, they were 1.5, 1, 2.1, 1.6, 0.5, and 0.8 ppm, respectively.

Preparation Example 2
Preparation of untreated potassium dodecylbenzenesulfonate In Preparation Example 1, the treatment with hydrogen-type strongly acidic cation exchange resin was carried out in the same manner as in Preparation Example 1, but untreated potassium potassium dodecylbenzenesulfonate having a pH of 8 A solution was prepared.

  When the concentrations of Na, Fe, Cu, Al, Ni, and Cr were measured by the atomic absorption method, they were 27, 12, 6, 9, 3, and 7 ppm, respectively.

Preparation Example 3
Preparation of ammonium dodecylbenzenesulfonate Ammonium dodecylbenzenesulfonate was prepared in the same manner as in Preparation Example 1 except that potassium hydroxide was changed to ammonia water (25% by mass ammonia, manufactured by Wako Pure Chemical Industries, Ltd. for the electronics industry). Was prepared.

  When the concentrations of Na, Fe, Cu, Al, Ni, and Cr were measured by the atomic absorption method, they were 0.7, 1, 5.1, 3, 0.9, 0.9, and 1.1 ppm, respectively.

Preparation Example 4
Preparation of untreated ammonium dodecylbenzenesulfonate The same procedure as in Preparation Example 2 was carried out except that the potassium hydroxide was changed to ammonia water (ammonia content 25% by mass, manufactured by Wako Pure Chemical Industries, Ltd. for electronic industry). An ammonium sulfonate solution was prepared.

  When the concentrations of Na, Fe, Cu, Al, Ni, and Cr were measured by the atomic absorption method, they were 20, 16, 7, 10, 5, and 8 ppm, respectively.

Example 1
1% by mass of fumed silica (manufactured by Nippon Aerosil Co., Ltd. # 90, average particle diameter after dispersion of 223 nm) was dispersed, and the potassium dodecylbenzenesulfonate solution of Preparation Example 1 (potassium dodecylbenzenesulfonate 0.03% by mass) And 100% by mass of a chemical mechanical polishing aqueous dispersion prepared by dissolving 1% by mass of hydrogen peroxide and adjusting the pH to 8.5 with KOH.

A wafer with wiring (SKW6-2 manufactured by SKW) is set in a chemical mechanical polishing apparatus (Ebara Manufacturing Co., Ltd., model “EPO-112”), and a porous polyurethane polishing pad (Rodel Nitta, product name “ using ICl000 "), polishing was carried out with a load 300 g / cm ^2. While supplying the aqueous dispersion to the surface of the urethane pad at a speed of 200 cc / min, the table was polished at 50 rpm, the head at 50 rpm and 30% over. Then, when the erosion of the wiring width of 100 micrometers was evaluated by the level | step difference and surface roughness meter (KLA Tencor Co., Ltd. model; P-10), it was 500 mm.

  Further, the polished wafer was washed in a 10% aqueous citric acid solution at 40 ° C. for 3 minutes, washed with water, dried, and then subjected to Fe on the surface with a total reflection X-ray fluorescence apparatus (device name: TREX-610T manufactured by Technos). , Al, Ni, Cr concentrations were measured. For Na, the wafer surface was treated with a hydrofluoric acid aqueous solution, and the amount of Na in the hydrofluoric acid aqueous solution was measured by atomic absorption.

As a result, Na was 0.3 ppm, Fe was 2 × 10 ¹⁰ atoms / cm ² , Al was 1 × 10 ¹⁰ atoms / cm ² , Ni was 1 × 10 ¹⁰ atoms / cm ² , and Cr was 1 × 10 ¹⁰ atoms / cm ² . cm ² .

Examples 2 to 5, Comparative Examples 1 and 2
The composition of the blend was changed as shown in Table 1, and the copper film polishing performance evaluation and metal analysis of the polished surface after polishing were performed in the same manner as in Example 1. The results are shown in Table 1.

  “DBK” and “DBA” in the table represent “potassium dodecylbenzenesulfonate” and “ammonium dodecylbenzenesulfonate”, respectively.

The unit of the amount of residual metal on the surface to be polished is ppm for Na and 10 ¹⁰ atoms / cm ² for Fe, Al, Ni, and Cr.

  The # 50 fumed silica used in Examples 2, 3, and 5 and the colloidal silica used in Example 4 and Comparative Example 2 were obtained as follows.

# 50 fumed silica Nippon Aerosil Co., Ltd. # 50 (average particle diameter after dispersion of 215 nm) was dispersed and used.

Preparation Example 5
Synthesis of colloidal silica Colloidal silica is based on J. of Colloid and Interface Science 26, 62-69 (1968), and is obtained by condensing tetraethoxysilane and ethanol in water and using ammonia as a catalyst to replace the solvent with water. Used. By adjusting the composition ratio of ethanol and water, the particle size was controlled, and colloidal silica having an average particle size of 67 nm was synthesized.

  According to the results of Table 1, in Examples 2 to 5, the erosion was 750 mm or less. On the other hand, Comparative Examples 1 and 2 have a problem of large erosion.

Example 6
2% by mass of fumed alumina (trade name “Alumina C”, manufactured by Degussa, average particle diameter of 127 nm after dispersion) is dispersed, 1% by mass of hydrogen peroxide and the potassium dodecylbenzenesulfonate solution of Preparation Example 1 ( 100 wt% chemical mechanical polishing aqueous dispersion prepared by adding potassium dodecylbenzenesulfonate 0.05 equivalent to 0.05 wt%) and adjusting the pH to 3.5 with KOH was prepared.

In addition, the wafer with wiring is set in a chemical mechanical polishing apparatus (Ebara Seisakusho, model “EPO-112”), and a porous polyurethane polishing pad (Rodel Nitta, trade name “ICl000”) is used with a weight of 300 g. Polishing was performed so as to be / cm ² . While supplying the aqueous dispersion to the surface of the urethane pad at a speed of 200 cc / min, the table was polished at 100 rpm and the head at 100 rpm with 30% over. Then, when the erosion of the wiring width of 100 micrometers was evaluated with the level | step difference and surface roughness meter (KLA Tencor Co., Ltd. model; P-10), it was 600 mm.

  Further, similarly to Example 1, the Na, Fe, Cu, Ni, and Cr concentrations on the polished wafer surface were measured.

As a result, Na is 1.3 ppm, Fe is 3 × 10 ¹⁰ atoms / cm ² , Cu is 1 × 10 ¹⁰ atoms / cm ² , Ni is 1 × 10 ¹⁰ atoms / cm ² , and Cr is 1 × 10 ¹⁰ atoms / cm ² . cm ² .

Examples 7 to 9, Comparative Examples 3 and 4
The compounding composition was changed as shown in Table 2, and the aluminum film polishing performance and the amount of residual metal were evaluated in the same manner as in Example 5.

  The results are shown in Table 2. In addition, KOH was added as needed for pH adjustment.

  “DBK” and “DBA” in the table represent “potassium dodecylbenzenesulfonate” and “ammonium dodecylbenzenesulfonate”, respectively.

The unit of residual metal amount on the surface to be polished is ppm for Na, and 10 ¹⁰ atoms / cm ² for Fe, Cu, Ni, and Cr.

  According to the results in Table 2, in Examples 7 to 9, the erosion was 800 mm or less. On the other hand, Comparative Examples 3 and 4 have a problem of large erosion.

Claims (2)

Chemical mechanical polishing aqueous dispersion used in the technique of forming wiring by removing excess copper or copper alloy by chemical mechanical polishing after embedding copper or copper alloy in holes or grooves formed in the insulating film on the wafer Body,
Fumed silica or colloidal silica, water, hydrogen peroxide, and at least one selected from potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate,
The total amount of potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate is 0.002% by mass or more and less than 1% by mass,
A chemical mechanical polishing aqueous dispersion having a pH of 7.5 or more and 9.0 or less. In claim 1,
Chemical mechanical polishing, wherein the content of alkali metal (excluding potassium) and polyvalent metal in at least one selected from potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate is 10 ppm or less for each metal species Aqueous dispersion.