WO2007074734A1 - Abrasive grain-free polishing liquid and cmp polishing method - Google Patents

Abstract

Disclosed is a CMP polishing liquid which is mixed with an oxidizing agent when used for polishing. This CMP polishing liquid contains a copper antirust agent, a water-soluble polymer, a pH-adjusting agent and water, and does not substantially contain abrasive grains. By using such a CMP polishing liquid, dishing in chemical polishing of copper can be effectively suppressed, thereby forming a wiring with high reliability. It is preferable that the contents of the antirust agent, water-soluble polymer and oxidizing agent are respectively 0.1-5% by weight, 0.05-5% by weight and 0.01-5M per 1 liter of the CMP polishing liquid, and the pH-adjusting agent is contained in such an amount necessary for adjusting the pH of the CMP liquid to 1.5-2.5.

Description

 Specification

 Abrasive-free polishing liquid and CMP polishing method

 Technical field

 [0001] This application claims the priority of Japanese Patent Application No. 2005-371858 filed on Dec. 26, 2005, and is incorporated herein by reference. The present invention relates to an abrasive-free polishing liquid and a CMP polishing method (a mechanical polishing method), and more particularly to a polishing liquid used for CMP polishing used in a wiring formation process of an electronic circuit such as a semiconductor device and the like. The present invention relates to a CMP polishing method.

 Background art

 [0002] Along with the higher performance of LSIs, as a microfabrication technology in the LSI manufacturing process, copper is embedded in an insulating film in which grooves have been formed in advance by the electroplating method, and then there is an excess other than the grooves for wiring formation. V, the so-called damascene method, is mainly used in which wiring is formed by removing the copper using chemical mechanical polishing CMP.

 [0003] In general, the polishing liquid used in CMP has an oxidizing agent and solid particle force, and a protective film forming agent, a metal oxide dissolving agent, and the like are added as necessary. As solid particles, fine particles such as silica, alumina, zirconium, and ceria of about several tens of nm are known as described in Patent Document 1 and the like. As the oxidizing agent, as described in Patent Document 2, hydrogen peroxide, iron nitrate, potassium ferricyanide, ammonium persulfate, and the like are known.

 [0004] Perspective of productivity improvement Improvement of the polishing rate of copper by CMP is required. Conventionally, as a method of improving the polishing rate, it is effective to add a metal oxide dissolving agent. This is thought to be due to the fact that the effect of scraping with solid barrels is increased by dissolving the particles of metal oxides scraped with solid barrels in the polishing liquid. It is also known to increase the concentration of other oxidizing agents by adding V.

[0005] In Patent Document 3, a water-insoluble copper compound and a soluble copper compound are formed on a copper wiring, Patent Document 4 adds an amino acid, and Patent Document 5 describes iron ( III) It describes that it contains compounds. Patent Document 6 describes aluminum, titanium, chromium, iron, edge It is described that the polishing rate can be increased by containing a polyvalent metal such as copper, nickel, copper, zinc, germanium and zirconium.

 [0006] On the other hand, if the polishing rate is improved, a dishing phenomenon occurs in which the center of the metal wiring portion is depressed like a dish, resulting in a problem of poor flatness. In order to prevent this, compounds containing a surface protecting action are usually added. This is because a dense protective film is formed on the copper surface to suppress copper ionization caused by the oxidizing agent and prevent excessive dissolution of the copper in the polishing liquid. In general, chelating agents such as benzotriazole (BTA) are known as compounds that exhibit this action. This is described in Patent Document 7 and the like.

 [0007] Generally, when a chelating agent such as BTA is added for the purpose of reducing dating, a protective film is also formed on a portion to be polished, so that the polishing rate is extremely reduced. In order to solve this, various additives have been studied. For example, as described in Patent Document 8, there is a substance containing a heteropolyacid and an organic polymer. Since this heteropoly acid has a high dissolution rate, an organic polymer compound is added to suppress the dissolution rate and prevent the occurrence of dating. Examples of the organic polymer include polybulal alcohol, polyacrylamide, polyacrylic acid such as polyacrylic acid, acrylate, polybutyl ester such as polyvinyl acetate, and polyallylamine.

 [0008] Patent Document 4 uses a method in which an inhibitor and an amino acid are used in combination. Patent Document 9 uses an aminoacetic acid or amidosulfuric acid and a protective film forming agent such as BTA. It describes a method for taking a non-oxy acid having a boxyl group and a protective film forming agent. In Patent Document 11, a heterocyclic compound (first complexing agent) that forms a water-insoluble complex with copper and copper forms a poorly water-soluble or soluble complex with copper, and one or more ligands are formed after complex formation. Those containing extra heterocyclic compounds (second complexing agents) are described.

 Patent Document 1: Japanese Patent Application Laid-Open No. 2001-210611

 Patent Document 2: Japanese Patent Laid-Open No. 2001-269859

 Patent Document 3: Japanese Patent Laid-Open No. 2001-110759

 Patent Document 4: Japanese Unexamined Patent Publication No. 2000-133621

Patent Document 5: Japanese Patent Laid-Open No. 10-163141 Patent Document 6: Japanese Patent Application Laid-Open No. 2001-269859

 Patent Document 7: JP-A-11-195628

 Patent Document 8: Japanese Patent Laid-Open No. 2002-299292

 Patent Document 9: Japanese Patent Laid-Open No. 08-083780

 Patent Document 10: Japanese Unexamined Patent Publication No. 2000-336345

 Patent Document 11: Japanese Unexamined Patent Publication No. 2003-168660

 Disclosure of the invention

 Problems to be solved by the invention

 [0010] In CMP, high speed is required to improve productivity. In addition, flatness of wiring is required for miniaturization and multilayering of wiring. However, both are in a trade-off relationship as described above, and it is extremely difficult to achieve both. As described above, generally, when a chelating agent such as BTA is added for the purpose of reducing dating, a protective film is also formed on the portion to be polished, so that the polishing rate is extremely reduced. In order to alleviate this, it has been studied to adjust the amount of the solubilizing agent and the chelating agent to optimize, but it is difficult to find a satisfactory condition. Although it may be possible to increase the polishing pressure to remove the protective film, this method is not appropriate in view of the fact that porous low dielectric constant insulating films will become the mainstream in the future. Various additives and methods for achieving both high speed and flatness as described above have been studied. Nothing has yet been developed that satisfies all conditions such as power performance, cost, and ease of use.

 An object of the present invention is to provide a CMP polishing liquid that suppresses dating and has a high polishing rate.

 Other objects, features and advantages of the present invention will become apparent from the following description of the present invention.

 Means for solving the problem

[0012] According to the present invention, a CMP polishing liquid used by mixing with an oxidizing agent during polishing, comprising a copper antifungal agent, a water-soluble polymer, a pH adjusting agent capable of forming a complex with copper, and water. A CMP polishing liquid characterized by being substantially free of abrasive grains is provided. In addition, the present invention includes an acid proofing agent, a copper antifungal agent, a water-soluble polymer, a pH adjusting agent capable of forming a complex with copper, and water. Do free of grain substantially, per cent during CMP polishing liquid Te, a step of polishing I copper spoon science under a load of LOgZcm ² below, the step of I匕学polishing under a load of more than LOG / cm ² The present invention provides a chemical polishing method for an electronic circuit containing copper, which is characterized by the inclusion. As used herein, “article” means “substantially does not contain the barrel” means alumina barrel (eg, brown alumina abrasive, white alumina abrasive, single crystal alumina) Abrasive grains), carbonized abrasive grains (eg, black carbide abrasive grains, green carbonized abrasive grains), zirconia alumina abrasive grains and super-abrasive grains (eg, diamond, CBN).

 The invention's effect

 [0013] According to the present invention, it is possible to effectively suppress dating and to form highly reliable wiring.

 BEST MODE FOR CARRYING OUT THE INVENTION

According to a preferred embodiment of the present invention, (i) dishing when forming embedded wiring, erosion reduction (mouth) high-speed polishing (c) simplification of cleaning after CMP can be achieved. A significant effect is achieved. A representative embodiment of the present invention will be described as follows.

 (Example embodiment)

 (1) The CMP polishing liquid of the present invention comprises a copper antifungal agent, a pH adjusting agent capable of forming a complex with copper, a water-soluble compound and water, and is mixed with an oxidizing agent at the time of use. If this abrasive is substantially free of gun particles, and preferably completely free of gun particles, problems such as erosion due to particles scraped off by the gun particles, which has been a problem with conventional CMP polishing liquids, are eliminated. It can be solved.

 [0015] (2) When pH is 2.5 or less, particularly 1.5 to 2.5, it is possible to balance dating suppression and polishing rate, and perform efficient CMP polishing.

[0016] (3) A preferred composition of the CMP polishing liquid of the present invention is such that the content of the antifungal agent, the water-soluble polymer and the acidic agent is 0.1 to 5 per liter of the CMP polishing liquid. % By weight, 0.05-5%

% And 0.01 to 5 M, and the amount of the pH adjusting agent is adjusted to the pH of the CMP polishing liquid from 1.5 to

2. This is the amount needed to adjust to 5.

[0017] (4) More preferably, the composition of the polishing liquid contains the antifungal agent, the water-soluble polymer and the oxidizing agent. The force is 0.3 to 1% by weight, 0.1 to 2% by weight and 0.01 to 5M per liter of the CMP polishing liquid, and the amount of the pH adjusting agent is the pH of the CMP polishing liquid 1. This is the amount necessary to adjust to 5 to 2.5.

 [0018] (5) The water-soluble polymer is preferably at least one selected from a polymer having a carboxyl group, a polymer having a sulfone group, and a polymer containing nitrogen. In particular, polyacrylic acid, polyacrylic acid salt, copolymer of acrylic acid and acrylate ester, and copolymer power of acrylic acid and acrylamide are also at least one selected. The water-soluble polymer having a sulfone group is at least one selected from the salt strength of an amine compound polymer having a sulfone group and an amine compound polymer having a sulfone group. The water-soluble polymer containing nitrogen is at least one selected from polyvinylpyrrolidone, polyethyleneimine, and polyacrylamide power.

 [0019] (6) Preferably, the copper antifungal agent is an unsaturated heterocyclic compound containing nitrogen. In particular, at least one of quinoline, benzotriazole, benzimidazole, indole, isoindole and quinaldic acid is preferred! /.

 [0020] (7) The pH adjuster is preferably an organic acid, an inorganic acid or a mixed solution thereof. It is preferable that the concentration (% by weight) of the copper antifungal agent is higher than the concentration (% by weight) of the water-soluble polymer.

 [0021] (8) The logarithm of the formation constant of the complex of the organic acid or inorganic acid and copper is preferably 3 or more.

 [0022] (9) The water-soluble polymer is preferably at least one water-soluble polymer selected from a polymer having a carboxyl group, a polymer having a sulfone group, and a polymer power containing nitrogen.

[0023] (10) Due to the water-soluble polymer, the exchange current density of copper does not substantially increase under a load rotation of load lOgZcm ² or less, and under a load rotation exceeding load lOgZcm ^2. CMP polishing fluids that increase copper exchange current density are preferred

(11) The load on the copper to be polished is 0 to: Under the CMP polishing condition of LOgZcm ² , the exchange current density does not substantially increase, and the replacement is performed under the CMP polishing condition under a load exceeding lOgZcm ^2. Current density force 0 ~: Interchange in CMP polishing under load rotation of LOgZcm ² More than twice the exchange current density and substantially free of abrasive grains are preferred.

[0025] (12) The load on the copper to be polished is 0 to: Under CMP polishing conditions of LOgZcm ²

, Without increasing substantially the exchange current density, the exchange current density strength under CMP polishing conditions under load of more than lOgZcm ² 0~: the exchange altering current density in the CMP polishing under load rotation LOgZcm ² at 5 times or more Preferably there is.

[0026] (13) The water-soluble polymer exhibits an effect of suppressing dissolution of copper at a load of lOgZcm ² or less, and exhibits an effect of promoting the dissolution of copper at a load exceeding lOg / cm ^2. Is preferred.

[0027] (14) The exchange current density of copper under no load rotation is 30 AZcm ² or less, and the exchange current density of copper under load rotation with a load lOgZ cm ² is twice that under no load rotation. It is as follows. Moreover, the exchange current density of copper under load rotation imparted with load 150GZcm ² is approximately 5 times or more when the Muni heavy rotation under substantially Do contain guns grains, preferred is CMP polishing liquid.

[0028] (15) The chemical polishing method according to the present invention includes an oxidizing agent, a copper antifungal agent, a water-soluble polymer, a pH adjusting agent capable of forming a complex with copper, and water, and substantially does not contain abrasive grains. ! / ヽ Chemical polishing of copper under a load of 10g / cm ² or less and chemical polishing under a load exceeding 10g / cm ² in CMP polishing liquid. In particular, it is desirable to polish while adjusting the load so as to minimize dating.

 [0029] In order to improve the flatness, the details will be described later. First, the dissolution of copper in the part where the load is applied (under load rotation), that is, the part where the copper is in contact with the node In addition to improving the speed, it is important to suppress the dissolution rate of copper in the part where the load is not applied (under no-load rotation), that is, when the copper is in direct contact with the node. Secondly, the low load dependency of the copper dissolution rate is also an important factor in the low load region, that is, the region where the pad slightly contacts the copper. Thirdly, a polishing liquid having the above first and second characteristics is prepared without containing any barrels.

In view of this, in order to solve the above-mentioned problems, the composition of the polishing slurry for CMP of the present invention is at least (1) an oxidizing agent (peroxide-hydrogen, etc.) and (2) copper is dissolved. Compound (organic acid and Z or inorganic acid) that forms a complex with copper together with (3) Under load rotation and under no load rotation! / Dissolution inhibitor that suppresses copper dissolution (such as BTA Copper antifungal agent) and (4) under load rotation, The basic composition is to contain a compound (water-soluble polymer) that promotes copper dissolution and suppresses copper dissolution under no-load rotation. The above solutions (1) and (2) to (4) are prepared separately and mixed immediately before use.

 [0031] As the metal oxidizing agent in the present invention, peroxides represented by hydrogen peroxide, hypochlorous acid, peracetic acid, dichromate compounds, permanganate compounds, persulfate compounds, iron nitrate, ferricia There is a compound. Of these, hydrogen peroxide, which is harmless to decomposition products, is preferably a persulfate represented by ammonium persulfate. In particular, hydrogen peroxide is preferred. The content of the oxidizing agent varies depending on the oxidizing agent used. For example, it is about 0.5 to 3M when using hydrogen peroxide and 0.05 to 0 when ammonium persulfate is used. About 2M is preferred. Usually, a solution containing a copper antifungal agent, a pH adjusting agent capable of forming a complex with copper, a water-soluble polymer and water is prepared, and the solution and the oxidizing agent are mixed before use.

 [0032] Examples of the inorganic acid include phosphoric acid and pyrophosphoric acid, and examples of the organic acid include carboxylic acid. The carboxylic acids include monocarboxylic acid, formic acid, acetic acid, dicarboxylic acid, oxalic acid, maleic acid, malonic acid, succinic acid, oxycarboxylic acid, tartaric acid, citrate, malic acid, and benzoic acid, which is an aromatic carboxylic acid. There are acid, phthalic acid, etc., especially oxy power rubonic acid is effective. In addition, amino acids, aminoamino sulfates and their salts, glycine, and aspartic acid are also effective. These contents vary depending on the pH to be adjusted. That is, in order to adjust the pH depending on the amount of added acid of these acids, the amount of added acid varies depending on the type of acid used. The pH to be adjusted is preferably 2.5 or less, more preferably between 5 and 2.5, and most preferably between 1.5 and 2. These acids can obtain the same effect when used alone or in combination. As the acid used here, it is important to form a complex with copper, and it is particularly desirable that the logarithm value of the formation constant is 3 or more.

 [0033] The amount of inorganic acid or organic acid, which is a pH adjusting agent capable of forming a complex with copper, depends on the pH of the solution (water-soluble polymer, copper antifungal agent and water) before mixing with the oxidizing agent. Less than 5, especially 1.5 to 2.5. The amount of acid required for pH adjustment varies depending on the type of acid added.

[0034] In the present invention, a solution that suppresses dissolution of copper under load rotation and no-load rotation. Anti-depressants include compounds that form insoluble complexes with copper, that is, triazoles represented by benzotriazole, triazole derivatives, quinaldates, compounds having a heterocyclic ring such as oxine, benzoinoxime, anthrallic acid, It has been found that salicylaldoxime, nitrosonaphthol, cuperone, haloacetic acid, cysteine and the like have such properties. These concentrations are preferably from 0.005M to 0.2M (0.06 to 2.4% by weight), and most preferably about 0.02 to 0.1M (0.25 to: L 2% by weight). These can be used to obtain the same effect even when used alone or in combination.

 [0035] When the load in the present invention is applied, the part (under load rotation), that is, the copper comes into contact with the pad, improves the dissolution rate of copper in the part, and the load is applied! Contains a polymer having a carboxyl group, a polymer having a sulfone group, and nitrogen as a compound that inhibits the dissolution rate of copper in the / ヽ part (under no-load rotation), that is, where the copper is not in direct contact with the pad It has been found that it is at least one water-soluble polymer selected from polymers. Examples of the polymer having a carboxyl group include polyacrylic acid and salts thereof (potassium salt, ammonium salt), a copolymer of acrylic acid and an acrylate ester, a copolymer of acrylic acid and acrylamide, and the like. Yes, these can be used alone or in combination. Examples of the water-soluble polymer having a sulfone group include amine compound polymers having a sulfone group and salts thereof. These can be used alone or in combination. Examples of the water-soluble polymer containing nitrogen include polybulurpyrrolidone, polyethyleneimine, and polyacrylamide. These can be used alone or in combination.

 [0036] Any water-soluble polymer can be used, but an ionic polymer is particularly preferable. These concentrations are preferably 0.05 to 10% by weight, particularly 0.1 to 1% by weight. The upper limit of the concentration is particularly preferred depending on the concentration of the copper antifungal agent as described below. .

[0037] In the present invention, an important point is the concentration balance between (3: copper antifungal agent) and (4: water-soluble polymer). The action of these copper antifungal agents and water-soluble polymers both suppress the dissolution of copper under no-load rotation. However, copper antifungal agents suppress dissolution even under load rotation (inhibition effect is reduced by applying a load), but water-soluble In addition to being adjusted to the above-mentioned concentration ranges in order to promote the dissolution of copper and to suppress the dissolution of copper under the rotation of the load, the polymer (3) and ( 4) Controlling the concentration ratio is necessary to achieve low date. In the present invention, it has been found that the concentration (wt%) of the compound (3) needs to be larger than the compound concentration (wt%) of (4). Even if the concentrations of (3) and (4) are within the above-mentioned concentration range, if the concentration is not controlled within this relationship, low dicing cannot be achieved.

 [0038] In the present invention, the abrasive grain is as small as possible, preferably S, and even if included, it is 0.5% by weight or less, preferably 0.3% by weight or less, and most preferably not contained at all. Nothing is good. The reason for this is to avoid obstacles such as erosion caused by the barrel. In addition, in the polishing liquid 5 of the present invention, various additives can be added as necessary in addition to the four main components. For example, there are surfactants such as water-soluble monomers such as methanol and ethanol and potassium dodecylbenzenesulfonate.

 [0039] The principle of the present invention will be described below. As described above, in order to improve the flatness, the copper dissolution rate is improved at the portion where the load is applied (under load rotation), that is, the portion where the copper is in contact with the pad, and the load is applied. It is important to suppress the dissolution rate of copper in the part (under no-load rotation), ie where the copper is not in direct contact with the pad. Another important factor is that the dissolution rate does not change drastically due to load fluctuations in the low load region.

[0040] As shown in Fig. 1 (a), when the copper electroplating 2 is applied on the insulating film 1 having a groove formed on the substrate surface, a shape 3 in which a portion corresponding to the normal wiring portion is depressed is shown. . During polishing, a polishing liquid 5 (polishing liquid) is supplied from the nozzle 6 between the pad 4 and the copper film 2. In the state where CMP is performed (Fig. 1 (b)), the copper 2 and the pad 4 are not in contact with each other in the recessed wiring part, and the pad 4 and the copper 2 are not in the part other than the wiring part. In contact. If the polishing rate at the portion that is in contact with copper is the same as the polishing rate at the portion that is not in contact with the copper, the shape after polishing is maintained as it is before polishing. On the other hand, when the polishing rate at the contacted part is slower than the polishing rate at which the contacted part is not, the depth of the recess in the wiring part becomes shallow as the polishing progresses, as shown in FIG. Therefore, it shows such characteristics The polishing liquid can achieve both high-speed polishing and low dateing. Even if the polishing rate of the copper in the part V is low when it contacts the node, if the polishing rate of the part that is in contact with the pad is slow, it takes time to polish to reduce the copper polishing residue. In the meantime, contact with the pad will cause the copper elution of the part to proceed, and low dating cannot be achieved.

 [0041] Further, when a slight load is applied, or when the dissolution rate increases rapidly, in other words, when the load dependency of the dissolution rate of copper is large in the low load region, polishing is performed. At the stage where the near nora near the end begins to appear on the surface, if the load is applied even a little, if the dissolution rate increases rapidly, the dissolution of copper will increase rapidly while maintaining the nora metal. Therefore, it is difficult to achieve flatness (even if the load is strong and the load is strong, even if the difference in solubility between the parts is large).

 [0042] In order to investigate the load dependence of the dissolution rate of copper in various polishing liquids, Fig. 2 (a),

 The device shown in (b) was devised. In the figure, (a) shows the overall configuration of the apparatus, and (b) is an enlarged view of part A of (a). The dissolution rate of copper was determined as the exchange current density. The rotating shaft 20 of the rotating electrode 19 having the copper electrode 13 is attached to the motor 10 having the rotating speed control mechanism 11 and pressed against the pad. The load applied to the pad is measured using a scale 14, and the load applied to the copper electrode 13 is adjusted using a link mechanism 16 fixed to a stand 17 installed under the scale.

 [0043] The dissolution rate of copper was measured by the electrochemical measurement system 12 using the reference electrode 15 under the condition of presence or absence of load (under no load rotation and under load rotation) in the rotated state. The measurement was obtained as an exchange current density by Tafel measurement. Using Tafel's relational expression, that is, the potential range is overvoltage (potential difference from immersion potential) between 70 mV and 135 mV, the logarithm of the current and the potential become a straight line. The current value was defined as the exchange current density.

[0044] For the measurement of the exchange current density, a commercially available rotating ring disc electrode with a ring platinum electrode on which copper was electroplated to a thickness of 10 to 20 m was used (the disc was similarly subjected to copper plating). However, only the ring electrode is used for measurement). Before measuring the exchange current density, after polishing with a load rotation of 150 gZcm ² for a certain period of time, under no load rotation and under any load Polarization measurements were carried out under the applied load rotation conditions. The rotation speed was 2000 rpm so that it was almost the same as the peripheral speed during actual polishing. The scanning speed of the potential was 30 mVZ min, and the potential was scanned from the immersion potential to the anode side.

 [0045] As a result of evaluation using this apparatus, when an organic acid or inorganic acid, and an oxidizing agent are added, a copper antifungal agent is added, so that no load rotation and no load rotation occur. In either case, the copper dissolution rate was found to decrease. However, the inhibitory effect of copper antifungal agents decreases with increasing load under load rotation. This is thought to be because BTA is adsorbed on copper and is peeled off by mechanical force.

 [0046] Further, in the present invention, the addition of a water-soluble polymer that is one of the components of the CMP polishing liquid makes it possible to significantly reduce the amount of dishing. The function of this water-soluble polymer is that when a load is applied and under no-load rotation (corresponding to the case where copper is not in contact with the node), as with the antifungal agent, The dissolution of copper is suppressed by the key. However, under load rotation (corresponding to the case where copper is in contact with the node), it has been found that the copper dissolution rate is improved at the part where copper is in contact with the pad. As a water-soluble polymer having such a function, it has been found that at least one water-soluble polymer selected from a polymer having a carboxyl group, a polymer having a sulfone group, and a polymer containing nitrogen is effective. It was. Another feature of such a water-soluble polymer is that it suppresses the dissolution of copper when there is no load, but suppresses the dissolution of copper by the copper antifungal agent when coexisting with the copper antifungal agent. It has also become clear that it has the effect of reducing the effect. It is not clear why such characteristics appear in water-soluble polymers, especially ionic polymers.

 [0047] From these characteristics, if the concentration of the water-soluble polymer is increased too much, the effect of the copper dissolution inhibitor is killed, and as a result, the amount of dissolved copper cannot be reduced, and the dating is increased. Become. On the other hand, since these characteristics are intertwined in a complicated manner, it can be seen that dating can be suppressed if the concentration balance between the water-soluble polymer and the copper dissolution inhibitor is appropriately controlled.

[0048] The CMP polishing liquid of the present invention makes it possible to achieve both a high CMP polishing rate and suppression of dicing, and to form a highly reliable wiring. [0049] Hereinafter, the present invention will be described in detail by way of examples. The following evaluations were performed for Examples 1 to 14 and Comparative Examples 1 to 6.

 [0050] (Actual polishing evaluation)

A silicon substrate on which a 1 μm thick copper foil was formed was used as the substrate. A polyurethane resin having closed cells was used as a polishing pad. The relative speed between the substrate and the polishing surface plate was set to 36 mZmin. Load, it was 300gZcm ^2. The polishing rate during CMP was determined by converting the difference in film thickness of copper foil before and after CMP from the electrical resistance value. For the amount of dipping, a groove with a depth of 0.5 m is formed on the insulating film, and copper is embedded by a known sputtering method and electroplating method (Fig. La). The amount of reduction of the wiring metal part relative to the insulating part was calculated from the surface shape of the stripe pattern part in which the wiring metal part width of 100 m and the insulating part width of 100 m were alternately arranged using a step gauge.

 [0051] (Polishing evaluation)

 The dissolution rate under load rotation and no load rotation was determined as an exchange current density by Tafel measurement using an electrochemical method using the apparatus shown in FIG. The rotation speed was 2000 rpm. Details are described in Means for Solving Problems.

 [0052] (Example 1)

Malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidant, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), and 0.2wt% polyvinyl chloride as a water-soluble polymer -CMP was carried out using a polishing liquid that also has lepyrrolidone strength. The amount of the copper solubilizer added is adjusted so that the predetermined pH (pH 2.0) is obtained. As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 10 .: AZcm ² and less than twice the exchange current density of copper under no-load rotation (5.55 AZcm ² ) It is. On the other hand, the exchange current density of copper under a load rotation of 150 g / cm ² is 195 AZcm ^2, which is more than 5 times the dissolution rate under no load.

 [0053] (Example 2)

Maleic acid instead of malic acid used in Example 1 as copper solubilizer, 2.5M hydrogen peroxide as oxidizing agent, 0.5wt% benzotriazole as antifungal agent (protective film forming agent) Then, CMP was performed using a polishing liquid having a polyvinyl pyrrolidone power of 0.2 wt% as a water-soluble polymer. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0).

V, ru. As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 5

91 AZcm ² , less than twice the exchange current density of copper under no-load rotation (6.41 ^ A / cm ² ). In contrast, the exchange current density of copper under load rotation 150GZcm ² is 138 μ AZcm ^2, is more than five times greater than the dissolution rate under no load.

 [Example 3]

Instead of malic acid used in Example 1 as the copper solubilizer, oxalic acid was used as the oxidizing agent, 2.5M hydrogen peroxide, and 0.8 wt% benzotriazole (B TA as the antifungal agent (protective film forming agent)). ), And CMP was performed using a polishing liquid having a polyacrylic acid strength of 0.4 wt% as a water-soluble polymer. The addition amount of the copper solubilizer is adjusted so as to be a predetermined ρΗ (ρΗ1.8). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under a load rotation of lOgZcm ² in this polishing liquid is 5.23 AZcm ^2, which is less than twice the exchange current density of copper under no load rotation (4.68 AZcm ² ). . In contrast, the exchange current density of copper under load rotation 150GZcm ² is 63. a ² AZcm 2, is more than five times greater than the dissolution rate under no load.

 [Example 4]

 Instead of malic acid used in Example 1 as a copper solubilizer, phosphoric acid, which is an inorganic acid, is used as an acidifying agent, 2.5M hydrogen peroxide, and 0.7 wt% as an antifungal agent (protective film forming agent). CMP was performed using a benzotriazole of 0.4 wt% polyacrylic acid as a water-soluble polymer. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0).

V, ru. As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 4

64 AZcm ² , less than twice the exchange current density of copper under no-load rotation (5.59 ^ A / cm ² ). In contrast, the exchange current density of copper under load rotation 150GZcm ² is 42. AZcm ^2, is dissolution rate five times or more under no load.

[Example 5] Instead of malic acid used in Example 1 as the copper solubilizer, pyrophosphoric acid, which is an inorganic acid, is used as an oxidizing agent, 2.5M hydrogen peroxide, and as an antifungal agent (protective film forming agent), 0.3 wt% CMP was performed using zotriazole, a polishing solution with 0.2 wt% polyacrylic acid as a water-soluble polymer. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.3). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOg / cm ² in this polishing liquid is 35.1 AZcm ^2, which is ² of the exchange current density of copper (20.7 μ AZcm ² ) under no load rotation. Is less than double. In contrast, exchange altering current density of copper under load rotation 150GZcm ² is 267 AZcm ^2, is the dissolution rate of 5 times or more under no load

[0057] (Example 6)

Malic acid was used as the copper solubilizer, 2.5M hydrogen peroxide as the oxidizing agent, and 0.5wt% quinaldic acid as the antifungal agent (protective film forming agent) instead of the BTA shown in Example 1 in water. CMP was carried out using 0.2 wt% of a polyacrylamide polishing solution as a high molecular weight polymer. The addition amount of the copper solubilizer is adjusted so as to be a predetermined ρΗ (ρΗ1.50). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 10. δ μΑ / cm ² , twice the exchange current density of copper under no load rotation (8.09 AZcm ² ) It is as follows. In contrast, the exchange current density of copper under load rotation 150GZcm ² is 124 μ AZcm ^2, is more than five times greater than the dissolution rate under no load.

 [Example 7]

 Instead of malic acid used in Example 1 as a copper solubilizer, oxalic acid was used as an oxidizing agent, and 2.5 M potassium persulfate (KSO) was used as an oxidizing agent in place of peroxyhydrogen as shown in Example 1.鲭

2 2 8 CMP was performed using 0.4 wt% benzotriazole (BTA) as the agent (protective film forming agent) and 0.1 lwt% polyvinylpyrrolodon-powered polishing liquid as the water-soluble polymer. . The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 11.8 AZcm ² , Less than twice the exchange current density (10.5 AZcm ² ) of copper under no-load rotation. On the other hand, the exchange current density of copper under a load rotation of 150 gZcm ² is 240 / z AZcm ^2, which is more than 5 times the dissolution rate under no load.

 [Example 8]

Instead of malic acid used in Example 1 as the copper solubilizer, phosphoric acid, which is an inorganic acid, was used as the acid solubilizing agent. (Fe (N03) 3), 0.5 wt% salicylaldoxime as an antifungal agent (protective film forming agent), and 0.3% polyethyleneimine as a water-soluble polymer CMP was conducted. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.1). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 8.40 AZcm ^2, which is less than twice the exchange current density of copper under no load rotation (5. AZcm ² ). The On the other hand, the exchange current density of copper under a load rotation of 150 gZcm ² is 50. Ο μ cm Zcm ^2, which is more than 5 times the dissolution rate under no load.

 [Example 9]

Instead of malic acid used in Example 1 as a copper solubilizer, pyrophosphoric acid, an inorganic acid, 2.5M hydrogen peroxide as an oxidizing agent, and 0.8 wt% as an antifungal agent (protective film forming agent) CMP was performed using BTA as a water-soluble polymer and a polishing liquid composed of 0.3 wt% polyacrylamide. Adjust the amount of copper solubilizer so that it reaches the specified pH (pH 2.0). As shown in Table 1, good results were obtained for both the polishing rate and dishing. Exchange current density of copper under load rotation of LOgZcm ² in the polishing liquid is 4.18 is AZcm ^{2, 2} times the exchange current density of copper in no-load rotation under ^{(3. 68 ^ A / cm 2} ) It is as follows. In contrast, the exchange current density of copper under load rotation 150GZcm ² is 58. a ² / z AZcm 2, is more than five times greater than the dissolution rate under no load.

 [Example 10]

Instead of malic acid used in Example 1 as the copper solubilizer, maleic acid was used as the oxidizing agent, 2.5M hydrogen peroxide as the oxidizing agent, and 0.9 wt% BTA as the antifungal agent (protective film forming agent). CMP is carried out using a polishing liquid composed of 0.8% by weight polyethyleneimine as a polymer. It was. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOgZcm ² in this polishing liquid is 4.18 ^ A / cm ^2, which is less than twice the exchange current density of copper under no load rotation (1. AZcm ² ) It is. In contrast, the exchange current density of copper under load rotation 150GZcm ² is 62. a 3 μ AZcm ^2, is more than five times greater than the dissolution rate under no load.

 [Example 11]

Malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidizing agent, 0.4wt% benzotriazole as an antifungal agent (protective film forming agent), and 0.1wt% polyvinyl chloride as a water-soluble polymer -Lepyrrolidone as additive as 0.01 wt. CMP was performed using a polishing liquid consisting of / c ^ methanol power. Adjust the amount of copper solubilizer so that it reaches the specified pH (pH 2.0). As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under load rotation of lOgZcm ² in this polishing liquid is 10.9 AZcm ^2, which is ² of the exchange current density of copper under non-load rotation (9.82 ^ A / cm ² ). Is less than double. In contrast, the exchange current density of copper under load rotation 150GZcm ² is 234 AZcm ^2, is more than five times greater than the dissolution rate under no load.

 [0063] (Example 12)

Malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidizing agent, 0.4wt% benzotriazole as an antifungal agent (protective film forming agent), and 0.1wt% polyvinyl chloride as a water-soluble polymer -CMP was performed using a polishing fluid consisting of 0.01% by weight of potassium decylbenzenesulfonate as an additive. Adjust the amount of copper dissolving agent so that it reaches the specified pH (pH 2.0)! RU As shown in Table 1, good results were obtained for both the polishing rate and dishing. The exchange current density of copper under the load rotation of lOg / cm ² in this polishing liquid is 3.59 AZcm ² , and the exchange current density of copper under the no-load rotation (2. 09 A / cm ² ) Less than 2 times. In contrast, the exchange current density of copper under a load rotation of 150 g / cm ² is 201 μAZcm ^2, which is more than 5 times the dissolution rate under no load.

[0064] (Comparative Example 1) Nitric acid that does not form a complex with copper as a copper solubilizer, 2.5M hydrogen peroxide as an oxidizing agent, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), 0 as a water-soluble polymer CMP was performed using a polishing solution consisting of 2 wt% polybulurpyrrolidone. The addition amount of the copper solubilizer is adjusted so as to achieve a predetermined pH (pH 2.0). A different part from an Example is the kind of copper dissolving agent. As shown in Table 2, the force when polishing speed was good Dating was large and the force did not satisfy the specified value. The exchange current density of copper under no-load rotation in this polishing liquid was 37.4 / z AZcm ^{2 When} a slight load (lgZcm ² ) was applied, the exchange current density of copper under load rotation was 95.5 / z AZcm ² and rapidly increased to more than twice the exchange current density of copper under no-load rotation. Exchange current density of copper under load rotation 150GZcm ² is 274 AZcm ² or more, 5 times or more of the exchange current density of copper in no-load rotation under.

[0065] (Comparative Example 2)

As a copper dissolving agent, hydrochloric acid that does not form a complex with copper, 2.5M hydrogen peroxide as an oxidizing agent, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), 0 as a water-soluble polymer CMP was performed using a polishing solution consisting of 2 wt% polybulurpyrrolidone. The addition amount of the copper solubilizer is adjusted so as to achieve a predetermined pH (pH 2.0). A different part from an Example is the kind of copper dissolving agent. As shown in Table 2, the force when polishing speed was good Dating was large and the force did not satisfy the specified value. The exchange current density of copper under no-load rotation in this polishing liquid was 28.2 / z AZcm ^{2 When} a slight load (lgZcm ² ) was applied, the exchange current density of copper under load rotation was 84.5 / z AZcm ² and rapidly increased to more than twice the exchange current density of copper under no-load rotation. The exchange current density of copper under a load rotation of 150 gZcm ² is 288 μAZcm ² or more, more than 5 times the exchange current density of copper under no load rotation.

[0066] (Comparative Example 3)

Malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidant, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), and 0.2wt% polyvinyl chloride as a water-soluble polymer -CMP was carried out using a polishing liquid that also has lepyrrolidone strength. The amount of copper solubilizer added is adjusted to achieve the specified pH (pH 2.6). The difference from Example 1 is that the pH is high. It is in. For this reason, the polishing rate was strong enough to satisfy the slow specified value. When a slight load (lgZ cm ² ) was applied, the exchange current density of copper under load rotation was small, but it was more than twice the exchange current density of copper under no load rotation. Dating did not satisfy the large specified value.

 [0067] (Comparative Example 4)

Malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidant, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), and 0.2wt% polyvinyl chloride as a water-soluble polymer -CMP was carried out using a polishing liquid that also has lepyrrolidone strength. The amount of copper solubilizer added is adjusted to achieve a predetermined pH (pH 3.0). The difference from Example 1 is that the pH is high. For this reason, the polishing rate was strong enough to satisfy the slow specified value. When a slight load (lgZ cm ² ) was applied, the exchange current density of copper under load rotation was small, but it was more than twice the exchange current density of copper under no load rotation. Dating did not satisfy the large specified value.

 [0068] (Comparative Example 5)

CMP was performed using malic acid as a copper solubilizer, 2.5M hydrogen peroxide as an oxidizing agent, and a polishing solution having a polyacrylic acid power of 0.4wt% as a water-soluble polymer. The addition amount of the copper dissolution agent so that the predetermined _P H (pH2. 0) is adjusted. Since no antifungal agent is added, the exchange current density of copper under no-load rotation is significantly higher than in other comparative examples and examples. In this comparative example, unlike the case where other antifungal agents are added, the exchange current density of copper is reduced by applying a load (under load rotation). Therefore, the polishing rate was considerably larger than the specified value and showed a value, but the dateing was large and did not satisfy the specified value.

 [0069] (Comparative Example 6)

CMP is performed using malic acid as a copper dissolving agent, 2.5M hydrogen peroxide as an oxidizing agent, 0.5wt% benzotriazole as an antifungal agent (protective film forming agent), and a powerful polishing liquid. did. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0). The difference from Example 1 is that no water-soluble polymer is added. Under no-load rotation, VTA suppresses copper dissolution, so the exchange current density of copper is small! /, Under load rotation with a kana load (lgZcm ² ) applied, BTA easily desorbs from the copper force, so the exchange current density of copper increases rapidly as the applied load increases.

 [0070] With this polishing liquid, as shown in Table 2, the polishing rate was good. The force dating was large and the specified value was not satisfied.

 [Example 13]

Instead of malic acid used in Example 1 as a copper solubilizer, oxalic acid, 2.5M hydrogen peroxide as an oxidizing agent, 0.2wt% benzotriazole as an antifungal agent (protective film forming agent), CMP was performed using 0.2 wt% of a polyacrylic acid polishing solution as a water-soluble polymer. The addition amount of the copper solubilizer is adjusted so as to be a predetermined ρΗ (ρΗ1.8). The difference from Example 3 is that the concentration of the water-soluble polymer is higher than the concentration of the antifungal agent. In such a system, as shown in Table 2, when a slight load (lgZcm ² ) is applied, the exchange current density of copper under load rotation increases rapidly. This is because the water-soluble polymer has the effect of promoting the dissolution of copper under load rotation, so that the concentration of the water-soluble polymer is relatively higher than the concentration of the antifungal agent. The exchange current density of copper increases when a strong load is applied. In such a case, the polishing rate is good, but the amount of dishing is slightly increased.

 [Example 14]

Instead of malic acid used in Example 1 as a copper solubilizer, phosphoric acid, 2.5M hydrogen peroxide as an oxidant, 0.7 wt% benzotriazole as an antifungal agent (protective film forming agent), CMP was performed using a 0.7 wt% polyacrylic acid polishing solution as the water-soluble polymer. The amount of copper solubilizer added is adjusted to a predetermined pH (pH 2.0). The difference from Example 4 is that the concentration of the water-soluble polymer is the same as the concentration of the antifungal agent. In such a system, as shown in Table 2, when a slight load (lgZcm ² ) is applied, the exchange current density of copper under load rotation increases rapidly. This is because the water-soluble polymer has an effect of promoting the dissolution of copper under a load rotation, so that if the water-soluble polymer concentration is relatively higher than the concentration of the antifungal agent, it is not so powerful. Application of load increases the exchange current density of copper. In such a case, the polishing rate is good, but the amount of dishing is slightly increased. [0073] The load dependence of the exchange current density in the examples and the comparative examples in Tables 1 and 2 and, as shown in Fig. 3 in which it is illustrated, in an example with a small amount of dying, up to lOgZcm ² In the load range, the exchange current density of copper hardly changes. Beyond lOgZcm ² , the exchange current density of copper increases rapidly. On the other hand, in the case of the comparative example, the amount of dating is large, the load is 0, the exchange current density of copper is small! /, Even in this case, lgZcm ² is suddenly applied when a slight load is applied. The exchange current density increases.

[0074] [Table 1]

表 1

table 1

 Date Thing Evaluation ○: 1000A or less A: 1000 ~ 2000A x: 2000A or more

Polishing rate evaluation O: 3000 A / min or more △: 1000 to 2000 A / min x 1000 A / min or less

Table 2

 Dishing evaluation O: 1000 A or less Δ: 1000 to 2000 mm x: 2000 A or more

Polishing rate evaluation ○: 3000 A / min or more 厶: 1000 to 2000 A / min x: 1000 A / min or less

The composition that reduces the rate of change of the exchange current density of copper in the low load range is (1) an organic acid or inorganic acid that has the effect of dissolving copper and can form a complex with copper, (

2) Copper antifungal agents represented by BTA, quinaldic acid, salicylaldoxime (protective film forming agent), (3) High water-solubility represented by polybulurpyrrolidone, polyacrylic acid, polyacrylamide, polyethyleneimine A molecule is essential.

[0076] As shown in Comparative Examples 1 and 2, when the copper solubilizer is an acid that does not form a complex with copper, such as nitric acid or hydrochloric acid (or when the logarithm of the formation constant is small), the polishing rate is specified. Even if the value is satisfied, the amount of date increases. The logarithmic value of the formation constant of copper ion and hydrochloric acid ion is 0.08. Although not specifically shown in the comparative example, the sulfate ion (j8 1: 2.36) has a large dating as well. Acetic acid ions (j8 1: 1.83, j8 2: 3.09) were evaluated as △ with slightly large datesing. The phosphoric acid (j8 1: 3. 2) and maleic acid (1: 3.90), which have a slightly larger logarithm of the production constant than that, have less dating and are evaluated as ◯. Considering these, at least the logarithm of the generation constant must be 3 or more. In addition, as shown in Comparative Examples 3 and 4, even if the components (1) to (3) are contained, if the amount of copper solubilizer added is small and the pH is greater than 2.50, the polishing rate is also below the specified value. The amount of slow desiccation increases. As shown in Comparative Example 6, when no copper antifungal agent is added, the polishing rate is increased, but the amount of dishing is also increased. As shown in Examples 13 and 14, even when the components (1) to (3) are contained and the pH is 2.0 or more, the concentration of the water-soluble polymer is If it is higher than the concentration, the amount of dishing will be slightly higher even if the polishing rate is satisfactory. These relationships are illustrated in FIG. 4, and high flatness can be obtained in a region above a certain ratio.

 While the above description has been made with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention and the appended claims.

 Brief Description of Drawings

 [0077] FIG. 1 is a process diagram for removing an excess copper layer on a wiring trench formed on a silicon substrate by CMP;

 (a) shows before CMP, (b) shows during CMP, and (c) shows after CMP.

FIG. 2 is a conceptual diagram of an exchange current density measuring device under a polishing load. FIG. 3 is a graph showing the load dependence of the dissolution rate of copper in various CMP polishing liquids.圆 4] Graph showing the relationship between copper antifungal concentration and water-soluble polymer concentration and flatness. Explanation of symbols

 1 Interlayer insulation film

 2 Copper electrical plating

 3 depression

 4 Polishing pad

 5 Polishing liquid

 10 Motor

 11 Rotation control system

 12 Electrochemical measurement system

 13 Copper electrode

 14 Scale

 15 Reference electrode

 16 Link mechanism

 17 Stand

 19 Rotating electrode

 20 axis of rotation

Claims

The scope of the claims  [1] A CMP polishing liquid used in admixture with an oxidant during polishing, including a copper antifungal agent, a water-soluble polymer, a PH adjusting agent capable of forming a complex with copper, and water. CMP polishing liquid characterized by V, not included in  [2] The CMP polishing liquid according to claim 1, which does not contain abrasive grains.  [3] The CMP polishing liquid according to claim 1, wherein the pH is 2.5 or less.  [4] The content of the antifungal agent, the water-soluble polymer and the oxidizing agent is 0.1 to 5% by weight, 0.05 to 5% by weight and 0.01 to 5M per liter of the CMP polishing liquid. The CMP polishing liquid according to claim 1, wherein the amount of the pH adjusting agent is an amount necessary for adjusting the pH of the CMP polishing liquid to 1.5 to 2.5.  [5] The content of the antifungal agent, the water-soluble polymer and the oxidizing agent is 0.3 to 1% by weight, 0.1 to 2% by weight and 0.01 to 5M per liter of the CMP polishing liquid. The CMP polishing liquid according to claim 1, wherein the amount of the pH adjusting agent is an amount necessary for adjusting the pH of the CMP polishing liquid to 1.5 to 2.5.  6. The CMP polishing according to claim 1, wherein the water-soluble polymer is at least one selected from a polymer having a carboxyl group, a polymer having a sulfone group, and a polymer containing nitrogen. liquid.  [7] The polymer having a carboxyl group is at least one selected from polyacrylic acid, polyacrylate, an ester copolymer of acrylic acid and acrylic acid, and a copolymer of acrylic acid and acrylamide, The water-soluble polymer having a sulfone group is at least one selected from an amine compound polymer having a sulfone group and a salt of the amine compound polymer having a sulfone group, and the water-soluble polymer containing nitrogen is 7. The CMP polishing liquid according to claim 6, wherein the polishing liquid is at least one selected from polybutyrolidone, polyethyleneimine, and polyacrylamide.  [8] The CMP polishing liquid according to claim 1, wherein the copper antifungal agent is an unsaturated heterocyclic compound containing nitrogen. [9] The nitrogen-containing unsaturated heterocyclic compound is at least one of quinoline, benzotriazole, benzimidazole, indole, isoindole and quinaldic acid. The CMP polishing liquid according to claim 8, wherein  10. The CMP polishing liquid according to claim 1, wherein the pH adjuster is an organic acid, an inorganic acid, or a mixed solution thereof.  11. The CMP polishing liquid according to claim 1, wherein the concentration (% by weight) of the copper antifungal agent is higher than the concentration of the water-soluble polymer (% by weight).  12. The CMP polishing liquid according to claim 10, wherein the logarithm of the formation constant of the complex of the organic acid or inorganic acid and copper is 3 or more. [13] The water-soluble polymer does not substantially increase the exchange current density of copper under a load rotation of load lOgZcm ² or less, and increases the exchange current density of copper under a load rotation exceeding load lOgZcm ^2. The CMP polishing liquid according to claim 1, wherein [14] In the CMP polishing under a load is 0～10GZcm ² to copper to be polished, substantive exchange current density does not increase, the exchange current density force in CMP polishing conditions under load of more than LOgZcm ² 0 to: Exchange in CMP polishing under load rotation of LOgZcm ² CMP polishing liquid characterized in that it is at least twice the current density and does not substantially contain a barrel [15] In the CMP polishing under a load is 0～10GZcm ² to copper to be polished, substantive exchange current density does not increase, the exchange current density force in CMP polishing conditions under load of more than LOgZcm ² 15. The CMP polishing liquid according to claim 14, wherein the CMP polishing liquid is 5 times or more the exchange current density in CMP polishing under load rotation of LOgZcm ² . [16] lOgZcm ² below shows the dissolution inhibiting effect of copper at the time of loading, CMP polishing liquid according to claim 1, wherein a shows the dissolution-promoting effect of copper at the time of load exceeding the lOgZcm ^2. [17] The exchange current density of copper under no-load rotation is 30 μ AZcm ² or less, and the exchange current density of copper under load rotation with load lOgZcm ² is less than twice that under no-load rotation. A CMP polishing liquid characterized in that the exchange current density of copper under load rotation with a load of 150 gZcm ² is more than five times that under no-load rotation and substantially contains no abrasive grains. [18] The CMP polishing liquid contains a copper antifungal agent, a water-soluble polymer, an oxidizing agent, and an acid. The water-soluble polymer includes a polymer having a carboxyl group, a polymer having a sulfone group, and 18. The CMP polishing liquid according to claim 17, wherein the polishing liquid is at least one water-soluble polymer selected from polymer power containing nitrogen. [19] The polymer having a carboxyl group is at least one selected from polyacrylic acid, polyacrylate, a copolymer of acrylic acid and an acrylate ester, and a copolymer of acrylic acid and acrylamide. The water-soluble polymer having a sulfone group is at least one selected from an amine compound having a sulfone group and an amine compound salt salt having a sulfone group, and the water-soluble polymer containing nitrogen is 19. The CMP polishing liquid according to claim 18, wherein polyburpyrrolidone, polyethyleneimine, and polyacrylamide are also selected. [20] The CMP polishing liquid according to claim 18, wherein the copper antifungal agent is an unsaturated heterocyclic compound containing nitrogen. [21] The nitrogen-containing unsaturated heterocyclic compound contains at least one of quinoline, benzotriazole, benzoimidazole, indole, isoindole, and quinaldic acid. CMP polishing liquid. [22] In a CMP polishing solution containing an oxidizing agent, copper antifungal agent, water-soluble polymer, pH adjusting agent capable of forming a complex with copper, and water, and substantially free of barrels, it is less than lOgZcm ² A method for chemically polishing an electronic circuit containing copper, comprising: a step of chemically polishing copper under a load; and a step of chemically polishing copper under a load exceeding lOgZcm ² .