Dry etching residue removal liquid

Abstract

Provided is a dry etching residue removal liquid containing: one or more oxidizing agents selected from the group consisting of hypobromite ions, bromate ions, bromite ions, hypochlorite ions, chlorate ions, and chlorite ions; one or more metals selected from the group consisting of Mg, Ca, Na, and K; and water, the pH of the residue removal liquid at 25 DEG C is 9.5 or more and 14 or less, and the total content of Mg, Ca, Na and K in the dry etching residue removal liquid is 0.01 ppt or more and 1000 ppt or less.

Description

Technical Field

[0001] The present invention relates to a residue removing liquid for removing residues after dry etching in a manufacturing process of a semiconductor device. Background Art

[0002] In semiconductor devices, a wiring layer is formed for the purpose of taking out the electrical signal generated by the transistor to the outside. The miniaturization of semiconductor devices is advancing year by year. When using materials with low electromigration resistance or high resistance, the reliability of semiconductor devices is reduced and high-speed operation is hindered. Therefore, as wiring materials, materials with high electromigration resistance and low resistance are desired.

[0003] As such a material, aluminum and copper have been used so far, and recently tungsten, cobalt, molybdenum, ruthenium, etc. are being studied. When forming a wiring layer on a semiconductor device, a process of processing the wiring material is included, and this process uses dry etching or wet etching.

[0004] The aforementioned wiring material is ruthenium. When ruthenium is wet-etched under alkaline conditions, ruthenium, for example, in the form of RuO 4 - 、RuO 4 2- The RuO 4 - 、RuO 4 2- In the residue removal solution, RuO 4 changes, and part of it is vaporized and released into the gas phase. 4 It is a strong oxidizing agent, so it is not only harmful to the human body, but also easily reduced to produce RuO 2 Particles. Generally, particles lead to a decrease in yield, and thus become a very serious problem in the semiconductor manufacturing process. Based on this background, the inhibition of RuO 4 Gas production is very important.

[0005] Patent Document 1 proposes a method that exhibits a good etching rate and stability of the rate and can suppress the RuO 4 The gas generates a semiconductor wafer residue removal liquid containing hypochlorite ions.

[0006] Patent Document 2 proposes a method having a good etching rate and stability of the rate and capable of suppressing RuO 4 The gas generates a semiconductor wafer residue removal liquid containing hypobromite ions.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2019 / 142788

[0010] Patent Document 2: International Publication No. 2021 / 059666 Summary of the invention

[0011] Problem that the invention aims to solve

[0012] When dry etching is performed on wiring materials, etching residues are sometimes produced as byproducts of dry etching. It is known that impurities such as etching residues may cause adverse effects such as reduced yield and reduced reliability of manufactured semiconductor devices. The etching residues are removed by a wet etching solution, but conventional wet etching solutions have a problem of poor storage stability of the oxidant contained in the wet etching solution.

[0013] Therefore, an object of the present invention is to provide an etching residue removing liquid having a high etching residue removing effect and an oxidizing agent having good storage stability in the liquid.

[0014] Solutions for solving problems

[0015] The present inventors have conducted intensive studies in order to solve the above-mentioned problems.

[0016] That is, the technical solution of the present invention is as follows.

[0017] Item 1: A dry etching residue removing liquid, which is a dry etching residue removing liquid used to remove residues after dry etching.

[0018] It contains: one or more oxidants selected from the group consisting of hypobromite ion, bromite ion, bromate ion, hypochlorite ion, chlorite ion and chlorate ion; one or more metals selected from the group consisting of Mg, Ca, Na and K; and water,

[0019] The pH of the residue removing solution is 9.5 or more and 14 or less at 25° C., and the total content of Mg, Ca, Na, and K in the dry etching residue removing solution is 0.01 ppt or more and 1000 ppt or less.

[0020] Item 2 The dry etching residue removing solution according to Item 1, wherein the concentration of the oxidizing agent is 0.0001 mol / L or more and 0.40 mol / L or less.

[0021] Item 3 The dry etching residue removing liquid according to Item 1, wherein the oxidizing agent is hypochlorite ions, and the concentration of the hypochlorite ions is 0.001 mol / L or more and 0.40 mol / L or less.

[0022] Item 4 The dry etching residue removing liquid according to Item 2, wherein the oxidizing agent is a hypobromite ion, and a concentration of the hypobromite ion is 0.001 mol / L or more and 0.20 mol / L or less.

[0023] Item 5. The dry etching residue removing liquid according to any one of Items 1 to 4, further comprising onium ions, wherein the surface tension of the residue removing liquid is 60 mN / m or more and 75 mN / m or less.

[0024] Item 6: The dry etching residue removing liquid according to Item 5, wherein the onium ion is one or more selected from the group consisting of onium ions represented by formula (1) to formula (6),

[0025]

[0026]

[0027] In formula (1) to formula (6),

[0028] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are independently an alkyl group having 2 to 9 carbon atoms, an allyl group, an aralkyl group having an alkyl group having 1 to 9 carbon atoms, or an aryl group, and at least one hydrogen atom in the ring of the aryl group or the ring of the aryl group in the aralkyl group is optionally substituted with fluorine, chlorine, an alkyl group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkenyloxy group having 2 to 9 carbon atoms, and at least one hydrogen atom in these groups is optionally substituted with fluorine, chlorine, bromine or iodine,

[0029] A is an ammonium ion or a phosphonium ion,

[0030] Z is an aromatic group or an alicyclic group optionally containing nitrogen, sulfur or oxygen atoms, in which carbon or nitrogen optionally has chlorine, bromine, fluorine, iodine, at least one alkyl group having 1 to 9 carbon atoms, at least one alkenyloxy group having 2 to 9 carbon atoms, at least one aromatic group optionally substituted with an alkyl group having 1 to 9 carbon atoms, or at least one alicyclic group optionally substituted with an alkyl group having 1 to 9 carbon atoms,

[0031] R is chlorine, bromine, fluorine, iodine, an alkyl group having 1 to 9 carbon atoms, an allyl group, an aromatic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms, or an alicyclic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms, n is an integer of 1 or 2, indicating the number of R, when n is 2, R may be the same or different, and may form a ring,

[0032] a is an integer from 1 to 10.

[0033] Item 7 The dry etching residue removing liquid according to Item 5 or 6, wherein the concentration of the onium ions is 1 mass ppm or more and 10000 mass ppm or less.

[0034] Item 8 A method for removing dry etching residue from a semiconductor wafer, comprising the step of bringing the dry etching residue removing liquid according to any one of Items 1 to 7 into contact with a semiconductor wafer.

[0035] Item 9 is a method for manufacturing a semiconductor device, comprising: a step of dry etching a semiconductor wafer; and a step of removing dry etching residue using the dry etching residue removing solution according to any one of Items 1 to 7.

[0036] Item 10 is a method for manufacturing a semiconductor device according to Item 9, characterized in that the semiconductor wafer is a semiconductor wafer having a ruthenium-based metal.

[0037] Effects of the Invention

[0038] According to the present invention, a dry etching residue removing liquid can be provided which can efficiently remove residue on a substrate caused by dry etching in a semiconductor device manufacturing process, has excellent storage stability, and further maintains the smoothness of the surface of a processed object described later. DETAILED DESCRIPTION

[0039] Hereinafter, the present invention will be described in detail. The following description is an example (representative example) of the present invention, and the present invention is not limited to these. In addition, the present invention can be implemented by arbitrarily changing it within the scope of its main purpose. The dry etching residue removing liquid of the present invention is characterized in that it is a composition containing a specific metal described later. In addition, in the present invention, the dry etching residue removing liquid (i.e., a chemical solution for removing the residue after dry etching) is also recorded as a residue removing liquid.

[0040] (Object to be processed)

[0041] The object to be processed (the object to be etched) to which the residue removal liquid of the present invention is applied is a semiconductor wafer containing a transition metal. The method for manufacturing the object to be processed is not particularly limited. For example, the object to be processed is obtained by the following method. A substrate such as silicon is subjected to oxidation treatment to form a silicon oxide film on the substrate, and an interlayer insulating film is formed thereon. Furthermore, a photoresist film is formed on the interlayer insulating film, and a through hole is formed in the interlayer insulating film. A metal film is formed in the formed through hole.

[0042] If an example of a transition metal is given, tantalum, silicon, copper, hafnium, zirconium, aluminum, vanadium, cobalt, nickel, manganese, gold, rhodium, palladium, titanium, tungsten, molybdenum, platinum, iridium, ruthenium, etc. can be listed, and their oxides, nitrides, and silicides can also be included. From the perspective of high electromigration resistance and low resistance value, tungsten, cobalt, molybdenum or ruthenium is preferred, and ruthenium is particularly preferred.

[0043] The metal film included in the object to be processed can be formed by any method, for example, CVD, ALD, PVD, sputtering, plating, etc.

[0044] (Dry etching residue)

[0045] The dry etching residue is a byproduct generated by dry etching and is a part of the aforementioned processed object, and examples thereof include Si-containing residue, metal-containing residue, and residue containing organic matter derived from photoresist.

[0046] (Dry Etching Residue Remover)

[0047] The dry etching residue removing solution (residue removing solution) of the present invention is a chemical solution for removing residues generated on a substrate due to dry etching. The residue removing solution of the present invention contains one or more oxidants selected from the group consisting of hypobromite ions, bromite ions, hypochlorite ions and chlorate ions, a specific metal described later, and water.

[0048] Hypochlorite ions and hypobromite ions are oxidants having strong oxidizing properties. The residue removing liquid of the present invention containing hypochlorite ions, hypobromite ions, etc. can etch transition metals at a high speed under alkaline conditions.

[0049] When the workpiece is ruthenium, the RuO 4 This not only improves the wafer processing efficiency per unit time, but also suppresses the generation of RuO 2 The yield rate is reduced due to particles, and it can be handled safely for the human body, achieving a balance between manufacturing cost and safety. Furthermore, by appropriately selecting pH, the type and concentration of the oxidant, RuO 4 The gas is generated and ruthenium is etched at a stable etching rate.

[0050] (Oxidant)

[0051] By including an oxidant in the dry etching residue removing solution of the present invention, a function of removing metals contained in the dry etching residue can be added. Furthermore, by including an oxidant in the alkaline dry etching residue removing solution, an effect of decomposing and peeling off the residue containing organic matter is achieved. In addition, in the alkaline aqueous solution, the surface potential of the insoluble residue containing inorganic matter and the object to be processed is negatively charged, so due to the effect of electrostatic repulsion, an effect of preventing the insoluble residue containing inorganic matter from reattaching to the substrate or the like is achieved.

[0052] The type of oxidant is not particularly limited, and examples thereof include one or more selected from the group consisting of hydrogen peroxide, ozone, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid, perbromic acid, hypoiodous acid, iodous acid, iodic acid, periodic acid (orthoperiodic acid, metaperiodic acid), their salts and ions generated by dissociation of their salts, and hydrogen peroxide, ozone, fluorine, chlorine, bromine, iodine, permanganate, chromate, dichromate and cerium salts. Among them, in terms of the strength of oxidizing power, stability, and suitability for semiconductor applications, preferred are hypobromite ion, bromite ion, bromate ion, hypochlorite ion, chlorite ion, chlorate ion, hypoiodite ion, iodite ion, iodate ion, and periodate ion; more preferred are hypobromite ion, bromate ion, bromite ion, hypochlorite ion, chlorate ion, and chlorite ion; further preferred are hypobromite ion, bromite ion, hypochlorite ion, and chlorate ion.

[0053] The concentration of the oxidant in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and can be 0.0001 mol / L or more and 0.50 mol / L or less, preferably 0.0001 mol / L or more and 0.40 mol / L or less. When it is less than 0.0001 mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.50 mol / L, the oxidant is easily decomposed, so sometimes the dry etching residue removal efficiency becomes difficult to stabilize.

[0054] The oxidant contained in the residue removing liquid of the present invention may be one or more. In the case of containing more than one, the type of the second oxidant contained in the second oxidant different from the first is not particularly limited, and examples thereof include hydrogen peroxide, ozone, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid, perbromic acid, hypoiodous acid, iodous acid, iodic acid, periodic acid, their salts and ions generated by dissociation of their salts, and further one or more selected from the group consisting of hydrogen peroxide, ozone, fluorine, chlorine, bromine, iodine, permanganate, chromate, dichromate and cerium salts. It should be noted that as the first oxidant, hypobromite ion or hypochlorite ion can be listed.

[0055] By including multiple oxidants, sometimes the residue removal rate is stabilized or the stability when the residue removal liquid is reused is improved. For example, in the case of containing hypobromite ions as the first oxidant, the hypobromite ions consumed by the etching of the metal lose their oxidizing power and change into bromide ions. In this case, the more the amount of bromide ions that change into, the lower the residue removal ability. In the manufacturing site of semiconductor wafers, from the perspective of cost reduction, the treatment liquid is usually circulated and reused, but if the residue removal ability is reduced due to the reuse of the treatment liquid, it is difficult to stably manufacture semiconductor wafers. On the other hand, in the case of including multiple oxidants in the residue removal liquid, for example, if hypochlorite ions are included in addition to hypobromite ions, the bromide ions that lose their oxidizing power are oxidized by hypochlorite ions and change into hypobromite ions. Therefore, the reduction of the hypobromite ion concentration in the residue removal liquid can be suppressed, and even in the case of reusing the residue removal liquid, it is not easy to produce a reduction in etching speed. When the residue removing liquid of the present invention contains a plurality of oxidizing agents, the total concentration of the oxidizing agents is preferably 0.0001 mol / L or more and 0.40 mol / L or less.

[0056] (Counter cation of oxidant)

[0057] As the counter cation of the oxidant, there is no particular limitation, preferably a metal ion or an onium ion described below. As examples of metal ions, calcium ions, sodium ions, potassium ions, magnesium ions, iron ions, chromium ions, nickel ions, zinc ions, copper ions, aluminum ions, etc. can be listed. In semiconductor manufacturing, if metal or metal ions remain on the semiconductor wafer, it is possible to make electrical properties and processed shapes abnormal, so it is preferably not contained as much as possible, and as the counter cation of the oxidant, it is preferably an onium ion.

[0058] (Hypobromite ion)

[0059] Hypobromite ions may be generated in the residue removal solution or added to the residue removal solution as hypobromite. The hypobromite referred to herein refers to a salt containing hypobromite ions or a solution containing the salt. -, also recorded as BrO) is generated in the residue removing liquid, for example, bromine gas is blown into the residue removing liquid. In this case, from the viewpoint of efficiently generating hypobromite ions, the residue removing liquid is preferably below 50°C. When the residue removing liquid is below 50°C, not only can hypobromite ions be efficiently generated, but the generated hypobromite ions can also be stably used for dry etching residue removal. Furthermore, in order to dissolve more bromine in the residue removing liquid, the temperature of the residue removing liquid is more preferably below 30°C, and most preferably below 25°C. There is no particular restriction on the lower limit of the temperature of the residue removing liquid, and it is preferred that the residue removing liquid does not freeze. Therefore, the residue removing liquid is preferably above -35°C, more preferably above -15°C, and most preferably above 0°C. There is no particular restriction on the pH of the residue removing liquid into which the bromine gas is blown, and as long as the pH of the residue removing liquid is alkaline, it can be provided for dry etching residue removal immediately after the generation of hypobromite ions.

[0060] Furthermore, when hypobromite ions are generated by blowing bromine gas into the residue removing liquid, if the residue removing liquid contains bromide ions (Br - ), then bromine gas (Br 2 ) is improved. This is because Br dissolved in the residue removal solution 2 With Br - Br 3 - Reaction to form Br 3 - Br 5 - Such complex ions are stabilized in the residue removal solution. 2 Br - Br 3 - Br 5 - The residue removing liquid of the above type can generate more hypobromite ions and thus can be suitably used as the residue removing liquid of the present invention.

[0061] Alternatively, hypobromite ions may be formed in the residue removing liquid by oxidizing the bromine-containing compound with an oxidizing agent.

[0062] In order to add the hypobromite ion as a compound to the residue removing solution, hypobromous acid, bromine water and / or hypobromite may be added. As the hypobromite, sodium hypobromite, potassium hypobromite, tetraalkylammonium hypobromite is preferred, and hypobromous acid or tetraalkylammonium hypobromite is further preferred from the aspect of not substantially containing metal ions that are problematic in semiconductor manufacturing.

[0063] The aforementioned tetraalkylammonium hypobromite is easily obtained by passing bromine gas through a tetraalkylammonium hydroxide solution. Alternatively, it can be obtained by mixing hypobromous acid and a tetraalkylammonium hydroxide solution. Furthermore, tetraalkylammonium hypobromite can also be obtained by replacing cations contained in hypobromites such as sodium hypobromite with tetraalkylammonium ions using an ion exchange resin.

[0064] The concentration of the aforementioned hypobromite ion in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001mol / L or more and 0.20mol / L or less in terms of hypobromite ion. When it is less than 0.001mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.20mol / L, the decomposition of hypobromite ions is likely to occur, so the dry etching residue removal efficiency is difficult to stabilize. In order to stably remove dry etching residues at a sufficient speed, the concentration of the hypobromite ion is preferably 0.001mol / L or more and 0.20mol / L or less, more preferably 0.005mol / L or more and 0.20mol / L or less, and most preferably 0.01mol / L or more and 0.10mol / L or less.

[0065] In order to alleviate the decrease in dry etching residue removal ability and stabilize the dry etching residue removal efficiency, the ratio of hypobromite ions to 1 mol of bromine element contained in the residue removal solution is preferably more than 0.5 mol. As described above, hypobromite ions are easily converted to Br by oxidation reaction and decomposition reaction of ruthenium. - Change. - The metal-containing residue is not etched, so the Br in the residue removal solution is - Rapidly oxidized to hypobromite ion, the chemical species with high dry etching residue removal ability (hypobromite ion; BrO - ) concentration is important for stable dry etching residue removal. When the ratio of hypobromite ions to 1 mol of bromine contained in the residue removing solution of the present invention exceeds 0.5 mol, that is, more than half of the bromine in the residue removing solution is in the form of BrO - In the case where the dry etching residue exists in the form of , it can be considered that the concentration of the chemical species having the dry etching residue removal ability is sufficiently high and the dry etching residue removal efficiency is stabilized.

[0066] The concentration of hypobromite ions in the residue removal solution can be confirmed using a widely known method. For example, if ultraviolet-visible absorption spectrophotometry is used, it is easy to confirm the absorption caused by hypobromite ions, and the hypobromite ion concentration can be obtained by the intensity of its absorption peak (depending on the pH of the residue removal solution, hypobromite ion concentration, etc., but roughly around 330nm). Furthermore, the hypobromite ion concentration can also be obtained by iodine titration. In addition, the hypobromite ion concentration can be obtained by the redox potential (ORP) of the residue removal solution. From the viewpoint of non-contact and continuous measurement, it is most preferably determined by ultraviolet-visible absorption spectrophotometry. It should be noted that when the hypobromite ion concentration is measured by ultraviolet-visible absorption spectrophotometry, in the presence of absorption caused by other chemical species, the hypobromite ion concentration can be obtained with sufficient accuracy by performing data processing such as spectral segmentation and baseline correction, appropriate selection of references, etc.

[0067] (bromite ion)

[0068] The dry etching residue removing solution of the present invention contains bromite ions (also referred to as BrO 2 - BrO 2 ), when the concentration is 0.0001 mol / L or more and 0.40 mol / L or less, the storage stability of the chemical solution can be improved.

[0069] The concentration of the aforementioned bromite ions in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001 mol / L or more and 0.20 mol / L or less in terms of the amount of bromite ions. When it is less than 0.001 mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.20 mol / L, the decomposition of bromite ions is likely to occur, so the dry etching residue removal efficiency is difficult to stabilize. In order to stably remove dry etching residues at a sufficient speed, the concentration of the bromite ions is preferably 0.001 mol / L or more and 0.20 mol / L or less, more preferably 0.001 mol / L or more and 0.10 mol / L or less, and most preferably 0.001 mol / L or more and 0.05 mol / L or less.

[0070] Bromite ions may be generated in the residue removing liquid, or may be added to the residue removing liquid as bromite salt. The bromite salt referred to herein refers to a salt containing bromite ions or a solution containing the salt.

[0071] Furthermore, bromite ions can also be formed in the residue removing liquid by oxidizing the bromine-containing compound with an oxidizing agent.

[0072] In order to add the bromite ion as a compound to the residue removing liquid, it is sufficient to add bromous acid, bromine water and / or a bromite. As the bromite, sodium bromite, potassium bromite, or tetraalkylammonium bromite is preferred. From the aspect of substantially not containing metal ions that are problematic in semiconductor manufacturing, bromous acid or tetraalkylammonium bromite is more preferred.

[0073] The concentration of bromite ions in the residue removal solution can be confirmed using a widely known method. For example, if ultraviolet-visible absorption spectrophotometry is used, it is easy to confirm the absorption caused by bromite ions, and the bromite ion concentration can be obtained from the intensity of its absorption peak (depending on the pH of the residue removal solution, the bromite ion concentration, etc., but roughly around 298nm). Furthermore, the bromite ion concentration can also be obtained by iodine titration. In addition, the bromite ion concentration can be obtained from the oxidation-reduction potential (ORP) of the residue removal solution. From the point of view of non-contact and continuous measurement, it is most preferred to use ultraviolet-visible absorption spectrophotometry. It should be noted that when the bromite ion concentration is determined by ultraviolet-visible absorption spectrophotometry, in the presence of absorption caused by other chemical species, the bromite ion concentration can be obtained with sufficient accuracy by performing data processing such as spectral segmentation and baseline correction, appropriate selection of references, etc.

[0074] (Bromoate ion)

[0075] The dry etching residue removing solution of the present invention contains bromate ions (also referred to as BrO 3 - BrO 3 ), when the concentration is 0.0001 mol / L or more and 0.40 mol / L or less, the storage stability of the chemical solution can be improved.

[0076] The concentration of the above-mentioned bromate ions in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001mol / L or more and 0.20mol / L or less in terms of the amount of bromate ions. When it is less than 0.001mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.20mol / L, the decomposition of bromate ions is likely to occur, so the dry etching residue removal efficiency is difficult to stabilize. In order to stably remove dry etching residues at a sufficient speed, the concentration of the bromate ions is preferably 0.001mol / L or more and 0.20mol / L or less, more preferably 0.001mol / L or more and 0.10mol / L or less, and most preferably 0.001mol / L or more and 0.05mol / L or less.

[0077] Bromate ions may be generated in the residue removing liquid, or may be added to the residue removing liquid as bromate. Bromate as referred to herein means a salt containing bromate ions, or a solution containing the salt.

[0078] In addition, bromate ions can also be formed in the residue removing liquid by oxidizing the bromine-containing compound with an oxidizing agent.

[0079] In order to add bromate ions as a compound to the residue removing solution, bromic acid and / or bromate salts may be added. As bromate salts, sodium bromate, potassium bromate, and tetraalkylammonium bromate are preferred. Bromic acid or tetraalkylammonium bromate is more preferred from the aspect of substantially not containing metal ions that are problematic in semiconductor manufacturing.

[0080] The concentration of bromate ions in the residue removing solution can be confirmed using a widely known method. For example, if ion chromatography is used, the peak of bromate ions can be easily confirmed, and the bromate ion concentration in the liquid can be obtained from the intensity and peak area of ​​its absorption peak. In addition, the bromate ion concentration can also be obtained from the oxidation-reduction potential (ORP) of the residue removing solution, liquid chromatography-mass spectrometry (LC / MS), and tandem mass spectrometry (LC / MS / MS).

[0081] (Hypochlorite ion)

[0082] The dry etching residue removing solution of the present invention contains hypochlorite ions (also referred to as ClO - , ClO), when the concentration is 0.001 mol / L or more and 0.40 mol / L or less, the storage stability of the chemical solution can be improved.

[0083] Hypochlorite ions can be generated in the residue removing liquid, or they can be added to the residue removing liquid as hypochlorite. The hypochlorite mentioned here refers to a salt containing hypochlorite ions, or a solution containing the salt. In order to generate hypochlorite ions in the residue removing liquid, for example, chlorine gas can be blown into the residue removing liquid. In this case, from the viewpoint of efficiently generating hypochlorite ions, the residue removing liquid is preferably below 50°C. When the residue removing liquid is below 50°C, not only can hypochlorite ions be efficiently generated, but the generated hypochlorite ions can also be stably used for dry etching residue removal. Furthermore, in order to dissolve more chlorine in the residue removing liquid, the temperature of the residue removing liquid is more preferably below 30°C, and most preferably below 25°C. There is no particular restriction on the lower limit of the temperature of the residue removing liquid, and it is preferred that the residue removing liquid does not freeze. Therefore, the residue removing liquid is preferably above -35°C, more preferably above -15°C, and most preferably above 0°C. The pH of the residue removing liquid into which the chlorine gas is blown is not particularly limited. As long as the pH of the residue removing liquid is alkaline, the residue removing liquid can be used for dry etching residue removal immediately after the generation of hypochlorite ions.

[0084] Furthermore, when hypochlorite ions are generated by blowing chlorine gas into the residue removing liquid, if the residue removing liquid contains chloride ions (Cl - ), then chlorine (Cl 2 ) is improved. This is because the Cl dissolved in the residue removal solution 2 With Cl - , Cl 3 - Reaction to form Cl 3 - , Cl 5 - Such complex ions are stabilized in the residue removal solution. 2 , Cl - , Cl 3 - , Cl 5 - The residue removing liquid of the above type can generate more hypochlorite ions and thus can be suitably used as the residue removing liquid of the present invention.

[0085] Alternatively, hypochlorite ions may be formed in the residue removing liquid by oxidizing the chlorine-containing compound with an oxidizing agent.

[0086] In order to add hypochlorite ions as a compound to the residue removing liquid, hypochlorous acid, chlorine water and / or hypochlorite may be added. As the hypochlorite, sodium hypochlorite, potassium hypochlorite, tetraalkylammonium hypochlorite is preferred, and hypochlorous acid or tetraalkylammonium hypochlorite is more preferred from the aspect of substantially not containing metal ions that are problematic in semiconductor manufacturing.

[0087] The tetraalkylammonium hypochlorite can be easily obtained by passing chlorine gas through a tetraalkylammonium hydroxide solution. Alternatively, it can be obtained by mixing hypochlorous acid and a tetraalkylammonium hydroxide solution. Furthermore, tetraalkylammonium hypochlorite can also be obtained by replacing cations contained in hypochlorites such as sodium hypochlorite with tetraalkylammonium ions using an ion exchange resin.

[0088] The concentration of the hypochlorite ion in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001mol / L or more and 0.40mol / L or less in terms of hypochlorite ions. When it is less than 0.001mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.40mol / L, the decomposition of hypochlorite ions is likely to occur, so the dry etching residue removal efficiency is difficult to stabilize. In order to stably remove dry etching residues at a sufficient speed, the concentration of the hypochlorite ion is preferably 0.001mol / L or more and 0.40mol / L or less, more preferably 0.01mol / L or more and 0.30mol / L or less, and most preferably 0.1mol / L or more and 0.20mol / L or less.

[0089] The concentration of hypochlorite ions in the residue removal solution can be confirmed using a widely known method. For example, if ultraviolet-visible absorption spectrophotometry is used, it is easy to confirm the absorption caused by hypochlorite ions, and the hypochlorite ion concentration can be obtained by the intensity of its absorption peak (depending on the pH of the residue removal solution, hypochlorite ion concentration, etc., but roughly around 292nm). Furthermore, the hypochlorite ion concentration can also be obtained by iodine titration. In addition, the hypochlorite ion concentration can be obtained by the redox potential (ORP) of the residue removal solution. From the viewpoint of non-contact and continuous measurement, it is most preferred to measure using ultraviolet-visible absorption spectrophotometry. It should be noted that when the hypochlorite ion concentration is measured using ultraviolet-visible absorption spectrophotometry, in the presence of absorption caused by other chemical species, the hypochlorite ion concentration can be obtained with sufficient accuracy by performing data processing such as spectral segmentation and baseline correction, appropriate selection of references, etc.

[0090] (Chlorite ion)

[0091] The dry etching residue removing solution of the present invention contains chlorite ions (also referred to as ClO 2 - , ClO 2 ), when the concentration is 0.0001 mol / L or more and 0.40 mol / L or less, the storage stability of the chemical solution can be improved.

[0092] The concentration of the chlorite ions in the residue removing solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001 mol / L or more and 0.20 mol / L or less in terms of the amount of chlorite ions. When it is less than 0.001 mol / L, the dry etching residue removal efficiency is low and the practicality is low. On the other hand, when it exceeds 0.20 mol / L, the decomposition of chlorite ions is likely to occur, so it is difficult to stabilize the dry etching residue removal efficiency. In order to stably remove dry etching residues at a sufficient speed, the concentration of chlorite ions is preferably 0.001 mol / L or more and 0.20 mol / L or less, more preferably 0.001 mol / L or more and 0.10 mol / L or less, and most preferably 0.001 mol / L or more and 0.05 mol / L or less.

[0093] Chlorite ions may be generated in the residue removing liquid, or may be added to the residue removing liquid as chlorite. The chlorite referred to herein refers to a salt containing chlorite ions or a solution containing the salt.

[0094] In addition, chlorite ions can also be formed in the residue removing liquid by oxidizing the chlorine-containing compound with an oxidizing agent.

[0095] In order to add chlorite ions as a compound to the residue removing liquid, chlorous acid, chlorine water and / or chlorite may be added. As the chlorite, sodium chlorite, potassium chlorite, or tetraalkylammonium chlorite is preferred, and chlorous acid or tetraalkylammonium chlorite is more preferred from the viewpoint of substantially not containing metal ions that are problematic in semiconductor manufacturing.

[0096] The concentration of chlorite ions in the residue removal liquid can be confirmed by a widely known method. For example, if ion chromatography is used, the peak of chlorite ions can be easily confirmed, and the chlorite ion concentration in the liquid can be calculated from the intensity and peak area of ​​the absorption peak.

[0097] (Chlorate ion)

[0098] The dry etching residue removing solution of the present invention contains chlorate ions (also referred to as ClO 3 - , ClO 3 ), when the concentration is 0.0001 mol / L or more and 0.40 mol / L or less, the storage stability of the chemical solution can be improved.

[0099] The concentration of the chlorate ions in the residue removal solution of the present invention is not particularly limited as long as it does not deviate from the purpose of the present invention, and is preferably 0.001 mol / L or more and 0.20 mol / L or less in terms of the amount of chlorate ions. When it is less than 0.001 mol / L, the dry etching residue removal efficiency is small and the practicality is low. On the other hand, when it exceeds 0.20 mol / L, the decomposition of chlorate ions is likely to occur, so the dry etching residue removal efficiency is difficult to stabilize. In order to stably remove dry etching residues at a sufficient speed, the concentration of the chlorate ions is preferably 0.001 mol / L or more and 0.20 mol / L or less, more preferably 0.001 mol / L or more and 0.10 mol / L or less, and most preferably 0.001 mol / L or more and 0.05 mol / L or less.

[0100] Chlorate ions may be generated in the residue removing liquid, or may be added to the residue removing liquid as chlorate. The chlorate referred to herein refers to a salt containing chlorate ions or a solution containing the salt.

[0101] Furthermore, chlorate ions can also be formed in the residue removing liquid by oxidizing the chlorine-containing compound with an oxidizing agent.

[0102] In order to add chlorate ions as a compound to the residue removing liquid, chloric acid and / or chlorate may be added. As the chlorate, sodium chlorate, potassium chlorate, or tetraalkylammonium chlorate is preferred, and chloric acid or tetraalkylammonium chlorate is more preferred from the aspect of substantially not containing metal ions that are problematic in semiconductor manufacturing.

[0103] The concentration of chlorate ions in the residue removing liquid can be confirmed by a widely known method. For example, if ion chromatography is used, the peak of chlorate ions can be easily confirmed, and the chlorate ion concentration in the liquid can be calculated from the intensity and peak area of ​​the absorption peak. In addition, the chlorate ion concentration can also be calculated from the oxidation-reduction potential (ORP) of the residue removing liquid.

[0104] (pH of dry etching residue removal solution)

[0105] Hypobromous acid (HBrO) and hypobromous ion (BrO - The acid dissociation constant (pK a ) is 8.6, hypochlorous acid (HClO) and hypochlorite ion (ClO - The acid dissociation constant (pK a ) is 7.5, so in the case of low pH, HBrO and BrO may be - , or HClO and ClO - Coexistence. The residue removal solution contains HBrO and BrO -In the case of HBrO and BrO - The total concentration of can be treated as the above hypobromite ion concentration. Similarly, the residue removing liquid contains HClO and ClO - In the case of HClO and ClO - The total concentration can be treated as the above-mentioned hypochlorite ion concentration.

[0106] In order to adjust the pH of the residue removal liquid, an acid or a base can be added to the residue removal liquid. As the acid, it can be any of an inorganic acid and an organic acid. If one example is given, it is a carboxylic acid such as hydrofluoric acid, hydrochloric acid, hydrobromic acid, nitric acid, acetic acid, sulfuric acid, peroxydisulfuric acid, formic acid, acetic acid, etc. In addition, it is also possible to use a widely known acid used in the residue removal liquid for semiconductors without any restrictions. As the base, from the aspect of not containing metal ions that become a problem in semiconductor manufacturing, it is preferred to use an organic base. If an example of an organic base is given, it is a tetraalkylammonium hydroxide containing tetraalkylammonium ions and hydroxide ions. If an example of the tetraalkylammonium hydroxide is given, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, ethyltrimethylammonium hydroxide, propyltrimethylammonium hydroxide, etc. can be listed. Among them, from the aspect of having a large number of hydroxide ions per unit weight and being able to easily obtain high-purity products, the organic base is preferably tetraalkylammonium hydroxide, and more preferably tetramethylammonium hydroxide.

[0107] The tetraalkylammonium ions contained in the residue removing liquid may be used alone or in combination of two or more.

[0108] (Metals contained in dry etching residue removing solution)

[0109] The dry etching residue removing liquid contains 0.01 ppt or more and 1000 ppt or less of one or more metals selected from the group consisting of Mg, Ca, Na, and K as specific metals, thereby further having an effect of maintaining the smoothness of the surface of the object to be processed.

[0110] Although the mechanism is not clear, it is believed that the target mixture is adsorbed on the surface of the transition metal-containing object to make the electronic state uniform, so the residue removing solution contains one or more metals selected from the group consisting of Mg, Ca, Na and K, which has the effect of maintaining the smoothness of the surface of the object to be treated. In addition, the total content of one or more metals selected from the group consisting of Mg, Ca, Na and K contained in the residue removing solution is 0.01 ppt or more and 1000 ppt or less, more preferably 0.01 ppt or more and 200 ppt or less, and further preferably 0.01 ppt or more and 50 ppt or less.

[0111] It should be noted that the dry etching residue removing solution may contain only Mg, only Ca, only Na, only K, only Mg, Ca, Na and K, only Mg, Ca and Na, only Mg, Ca and K, only Mg, Na and K, only Ca, Na and K, only Mg and Ca, only Mg and Na, only Mg and K, only Ca and Na, only Ca and K, or only Na and K. The content of the specific metal contained in the etching residue removing solution is the total content of all the metals contained.

[0112] In addition, the dry etching residue removing solution may contain one or more metals selected from the group consisting of alkali metals, alkaline earth metals, Fe, Cr, Ni, Zn, Cu and Al other than Mg, Ca, Na and K, depending on the manufacturing process. These metals do not contribute to the smoothness of the surface, but may be contained.

[0113] The dry etching residue removing solution of the present invention sometimes contains chloride ions, bromide ions, and iodide ions from its manufacturing process and raw materials. As long as their contents do not affect the removal of dry etching residues, they can be used without problems, and their respective concentrations are preferably not more than 1% by mass.

[0114] (Onium ion)

[0115] The residue removal liquid contains onium ions, which is effective in maintaining the smoothness of the surface. The surface of the object to be processed is also etched during the residue removal process, so it is required that the surface smoothness does not change before and after the treatment. In order to maintain the smoothness of the surface of the object to be processed within a preferred range, it is preferred to select one or more of the group consisting of onium ions having structures represented by the following formulas (1) to (6).

[0116]

[0117]

[0118] In formula (1) to formula (6),

[0119] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 They are independently an alkyl group having 2 to 9 carbon atoms, an allyl group, an aralkyl group having an alkyl group having 1 to 9 carbon atoms, or an aryl group. In addition, at least one hydrogen atom in the ring of the aryl group and the ring of the aryl group in the aralkyl group may be substituted with fluorine, chlorine, an alkyl group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkenyloxy group having 2 to 9 carbon atoms, and in these groups, at least one hydrogen atom may be substituted with fluorine, chlorine, bromine, or iodine.

[0120] Examples of counter anions for the onium ions include fluoride ion, chloride ion, bromide ion, iodide ion, hydroxide ion, nitrate ion, phosphate ion, sulfate ion, hydrogen sulfate ion, methylsulfate ion, perchlorate ion, chlorate ion, chlorite ion, hypochlorite ion, perbromate ion, bromate ion, bromite ion, hypobromite ion, orthoperiodate ion, metaperiodate ion, iodate ion, iodite ion, hypoiodite ion, acetate ion, carbonate ion, hydrogen carbonate ion, fluoroborate ion, or trifluoroacetate ion.

[0121] A is an ammonium ion or a phosphonium ion.

[0122] Z is an aromatic group or an alicyclic group optionally containing nitrogen, sulfur or oxygen atoms, in which carbon or nitrogen optionally has chlorine, bromine, fluorine, iodine, at least one alkyl group having 1 to 9 carbon atoms, at least one alkenyloxy group having 2 to 9 carbon atoms, at least one aromatic group optionally substituted with an alkyl group having 1 to 9 carbon atoms, or at least one alicyclic group optionally substituted with an alkyl group having 1 to 9 carbon atoms.

[0123] R is chlorine, bromine, fluorine, iodine, an alkyl group having 1 to 9 carbon atoms, an allyl group, an aromatic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms, or an alicyclic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms. n is an integer of 1 or 2, and indicates the number of R. When n is 2, R may be the same or different, and may form a ring.

[0124] a is an integer from 1 to 10.

[0125] The longer the hydrocarbon chain represented by R in the formula is, the higher the hydrophobicity is. Therefore, the more the residue removal liquid contains onium ions having long hydrocarbon chains, the lower the surface tension tends to be. On the other hand, if the hydrocarbon chain is too short, the improvement in surface smoothness as an effect of onium ions, the RuO 4 For such reasons, the carbon number of the hydrocarbon group is preferably within the above range.

[0126] The residue removing solution contains onium ions, which can suppress the generation of gas caused by metal oxides. For example, when the object to be treated is ruthenium, ruthenium is oxidized by the oxidant in the residue removing solution to generate RuO 4 - 、RuO 4 2- The RuO produced 4 - 、RuO 4 2- etc. interact with onium ions, thereby inhibiting the RuO 4 Gas production.

[0127] (Onium ion concentration)

[0128] The concentration of onium ions in the residue removing solution of the present invention is preferably 1 mass ppm or more and 10000 mass ppm or less. 4 - The interaction between the treated substances is weakened, such as RuO 4 The gas suppression effect is reduced, and the amount of onium ions attached to the metal surface during residue removal becomes insufficient, so there is a tendency for the surface smoothness to decrease. On the other hand, if the amount added is too much, the amount of onium ions adsorbed on the metal surface becomes too much, and the residue removal rate decreases. In addition, sometimes the concentration of the oxidant in the residue removing solution decreases due to the reaction between the oxidant and the onium ions. Therefore, the residue removing solution of the present invention preferably contains onium ions in an amount of 1 mass ppm or more and 10,000 mass ppm or less, more preferably 10 mass ppm or more and 5,000 mass ppm or less, and further preferably 50 mass ppm or more and 2,000 mass ppm or less. It should be noted that when adding onium ions, only one type may be added, or two or more types may be added in combination. Even when two or more onium ions are included, as long as the total concentration of the onium ions is within the above-mentioned concentration range, the RuO can be effectively suppressed. 4 Gas production.

[0129] Examples of such onium ions include choline chloride ion, choline bromide, trans-2-butene-1,4-bis(triphenylphosphonium ion), 1-hexyl-3-methylimidazolium ion, allyltriphenylphosphonium ion, tetraphenylphosphonium ion, benzyltriphenylphosphonium ion, methyltriphenylphosphonium ion, (2-carboxyethyl)triphenylphosphonium ion, (3-carboxypropyl)triphenylphosphonium ion, (4-carboxybutyl)triphenylphosphonium ion, (5-carboxypentyl)triphenylphosphonium ion, cinnamyltriphenylphosphonium ion, (2-hydroxybenzyl)triphenylphosphonium ion, (1-naphthylmethyl)triphenylphosphonium ion, butyltriphenylphosphonium ion, (tert-butoxycarbonylmethyl)triphenylphosphon ...hydroxybenzyl)triphenylphosphonium ion, (1-naphthylmethyl)triphenylphosphonium ion, butyltriphenylphosphonium ion, (tert-butoxycarbonylmethyl)triphenylphosphon Phenylphosphonium ion, (3-methoxybenzyl)triphenylphosphonium ion, (methoxymethyl)triphenylphosphonium ion, (1-ethoxy-1-oxopropane-2-yl)triphenylphosphonium ion, (3,4-dimethoxybenzyl)triphenylphosphonium ion, methoxycarbonylmethyl (triphenyl)phosphonium ion, (2,4-dichlorobenzyl)triphenylphosphonium ion, (2-hydroxy-5-methylphenyl)triphenylphosphonium ion, (4-chlorobenzyl)triphenylphosphonium ion, (3-chloro-2-hydroxypropyl)trimethylammonium ion, methacryloylcholine ion, benzoylcholine ion, benzyldimethylphenylammonium ion, (2-methoxyethoxymethyl)triethylammonium ion, carbamoylcholine ion, 1 ,1'-difluoro-2,2'-bipyridinium bis(tetrafluoroborate), benzyltributylammonium ion, trimethylphenylammonium ion, 5-azoniaspiro[4.4]nonane ion, tributylmethylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrabutylphosphonium ion, diallyldimethylammonium ion, 1,1-dimethylpiperidinium ion, (2-hydroxyethyl)dimethyl(3-sulfopropyl)ammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium ion, 1,1'-(decane-1,10-diyl)bis[4-aza-azoniabicyclo[2.2.2]octane] diion, (3-bromopropyl)trimethylammonium ion, vinylbenzyltrimethylammonium ion, allyltrimethyl The phosphonium ion is preferably selected from the group consisting of a benzyldimethylphenylammonium ion, a (1-ethoxy-1-oxopropane-2-yl)triphenylphosphonium ion, a 1,1'-(decane-1,10-diyl)bis[4-aza-azoniabicyclo[2.2.2]octane] diion, a butyltriphenylphosphonium ion, a (2-carboxyethyl)triphenylphosphonium ion, a (3-carboxypropyl)triphenylphosphonium ion, a (4-carboxybutyl)triphenylphosphonium ion, an allyltriphenylphosphonium ion, a tetraphenylphosphonium ion and a benzyltriphenylphosphonium ion.

[0130] As described above, the effects of onium ions include suppression of surface roughness during residue removal, RuO 4In addition to the suppression of gas, it also has the effect of increasing the number of times it is reused when used as a semiconductor residue removal liquid. In the manufacturing site of semiconductor wafers, from the perspective of cost reduction, the used residue removal liquid is sometimes recycled and filtered for reuse. In this case, for example, after the residue is removed, the metal is dissolved into the residue removal liquid, so the composition of the residue removal liquid is different before and after use. Taking the use of hypobromite ions to remove ruthenium residue as an example, ruthenium is converted into RuO under alkaline conditions. 4 - In this case, if the RuO 4 - or RuO 4 - RuO 4 2- 、RuO 4 The reaction with hypobromite ions reduces the concentration of hypobromite ions, which are chemical species effective for residue removal. Therefore, the more times the residue removal liquid is reused, and the longer the reuse time, the lower the residue removal rate.

[0131] However, by including onium ions in the residue removing solution, the stability during recycling can sometimes be improved. 4 - etc. react actively with onium ions, thereby suppressing the RuO 4 - As the onium ion that can be used for such a purpose, the phosphonium ion is preferably used. In the case of the ammonium ion, an amine may be generated due to the reaction with the hypobromite ion, so the amine may decompose the hypobromite ion. In addition, generally speaking, the molecular size of the phosphonium ion is larger than that of the ammonium ion, and it is easy to react with the RuO generated by dissolution. 4 - Forming ion pairs, thus binding RuO 4 - , RuO 4 - Effect of reaction with hypobromite ion.

[0132] In addition, it is preferred that the residue removing liquid contains onium ions, and the surface tension of the residue removing liquid is 60 mN / m or more and 75 mN / m or less. The surface tension is a value at 25°C.

[0133] By making the surface tension of the residue removing liquid 60mN / m or more, the onium ions interact with the metal surface of the semiconductor wafer, thereby suppressing the roughness of the metal surface. On the other hand, since the residue removing liquid of the present invention contains an oxidant, in order to prevent the stability of the oxidant from being reduced or the generation of obstacles to residue removal, the surface tension is preferably 75mN / m or less.

[0134] As one method of increasing the surface tension of the residue removing liquid, a method of adding a salt containing an anion with a high degree of hydration can be cited. By adding anions with a high degree of hydration, the neutralization of the charge of the onium ions caused by the anions is hindered, and the electrical repulsion between the onium ions is maintained, thereby increasing the surface tension. Examples of anions with a high degree of hydration include fluoride ions, chloride ions, and bromide ions.

[0135] The surface tension can be measured in accordance with JIS2241 "Test method using a Wilhelmy surface tension meter".

[0136] Examples of such onium ions include allyltriphenylphosphonium ion, tetraphenylphosphonium ion, trans-2-butene-1,4-bis(triphenylphosphonium ion), benzyltriphenylphosphonium ion, tetrabutylphosphonium ion, tributylhexylphosphonium ion, heptyltriphenylphosphonium ion, cyclopropyltriphenylphosphonium ion, (bromomethyl)triphenylphosphonium ion, and (chloromethyl)triphenylphosphonium ion.

[0137] (When the object to be processed is ruthenium)

[0138] In the present invention, ruthenium (Ru) as an example of the object to be processed may be a ruthenium-based metal or a ruthenium alloy.

[0139] When the treated material is a ruthenium-based metal and the pH is 9.5 or more and 14 or less at 25°C, harmful RuO is less likely to be generated. 4 Gas, due to RuO 2 There are also fewer particles caused.

[0140] The details of the mechanism by which hypobromite ions and hypochlorite ions dissolve ruthenium are not necessarily clear, but it is presumed that hypobromite ions or hypobromous acid generated from hypobromite ions, or hypochlorite ions or hypochlorous acid generated from hypochlorite ions in the residue removing solution oxidize ruthenium to form RuO 4 、RuO 4 - or RuO 4 2- , and thus dissolve in the residue removing solution. 4 - or RuO 4 2- dissolve in the form of RuO 4 The amount of gas generated inhibits RuO 2 Particle generation. In order to convert ruthenium into RuO 4 - or RuO 4 2-The pH of the residue removing solution is preferably 9.5 or more and 14 or less, more preferably 12 or more and 14 or less, and most preferably 12 or more and less than 13. If the pH of the residue removing solution is 12 or more and less than 13, ruthenium is dissolved in the form of RuO 4 - or RuO 4 2- It dissolves in the residue removal liquid in the form of RuO, thus significantly reducing 4 The amount of gas generated inhibits RuO 2 On the other hand, when the pH of the residue removing solution is less than 8, ruthenium is easily oxidized to RuO 2 、RuO 4 , so there is RuO 2 The amount of particles increases, and RuO 4 The amount of gas generated tends to increase. In addition, when the pH exceeds 14, it is difficult for ruthenium to dissolve and it is difficult to obtain a sufficient ruthenium etching rate, so the production efficiency in semiconductor manufacturing is reduced. It should be noted that the pH values ​​​​exemplified above are all values ​​at 25°C.

[0141] Here, the term "ruthenium-based metal" refers to ruthenium metal containing 70 atomic % or more of ruthenium, ruthenium oxide (RuO X ), nitride (RuN), nitrogen oxide (RuNO), etc. Here, the oxide of ruthenium is ruthenium dioxide, ruthenium trioxide (trihydrate). In addition, in the present invention, "ruthenium alloy" refers to an alloy containing ruthenium of more than 70 atomic % and less than 99.99 atomic % and containing a metal other than ruthenium at a concentration higher than the concentration inevitably contained. In the present invention, when there is no need to specifically distinguish between ruthenium-based metals and ruthenium alloys, they are recorded as ruthenium.

[0142] Ruthenium alloys may contain any metal other than ruthenium. Examples of metals contained in ruthenium alloys include tantalum, silicon, copper, hafnium, zirconium, aluminum, vanadium, cobalt, nickel, manganese, gold, rhodium, palladium, titanium, tungsten, molybdenum, platinum, iridium, etc., and may also contain oxides, nitrides, and silicides thereof.

[0143] These rutheniums may be intermetallic compounds, ionic compounds, or complexes. In addition, ruthenium may be exposed on the surface of the wafer or covered by other metals, metal oxide films, insulating films, resists, etc. Even when covered by other materials, when ruthenium contacts the residue removing solution of the present invention and dissolves ruthenium, the RuO 4 Furthermore, the residue removing solution of the present invention can suppress the generation of RuO from the minimally dissolved ruthenium even when the ruthenium is not actively dissolved, that is, even when the ruthenium is treated as a protected object. 4 gas.

[0144] (Method for manufacturing semiconductor device)

[0145] The method for manufacturing a semiconductor device of the present invention includes a step of dry etching a semiconductor wafer and a step of removing dry etching residue using the above-mentioned dry etching residue removing solution. Furthermore, before the step of dry etching the semiconductor wafer, a metal film forming step of forming a semiconductor wafer by forming a metal film on a semiconductor substrate may be included, and before and / or after the step of removing the dry etching residue, a step of rinsing the semiconductor wafer and a step of drying the semiconductor wafer may be included.

[0146] By using a dry etching residue removing liquid after the process of dry etching a semiconductor wafer (the process of dry etching a metal film on a semiconductor substrate), residues can be removed more efficiently than when only dry etching is used. Furthermore, the surface smoothness of the metal film surface can be processed without damaging it compared to when only wet etching is used.

[0147] In the process of washing the semiconductor wafer, the semiconductor wafer can be cleaned by contacting the washing liquid with the semiconductor wafer. The washing liquid can be selected from the group consisting of water, ozone water, free radical water, functional water such as electrolytic ion water, organic solvents such as 2-propanol, ammonia hydrogen peroxide mixture, hydrochloric acid hydrogen peroxide mixture, sulfuric acid hydrogen peroxide mixture, nitric acid hydrofluoric acid mixture, hydrofluoric acid, sulfuric acid, phosphoric acid, nitric acid, buffered hydrofluoric acid, ammonia, hydrogen peroxide, hydrochloric acid, tetramethylammonium hydroxide (TMAH) and mixtures thereof with water.

[0148] The step of drying the semiconductor wafer is not particularly limited, and the semiconductor wafer may be dried by spin drying, IPA drying, Marangoni drying, Rotagoni drying, or the like.

[0149] In addition, the method for manufacturing a semiconductor device may include one or more steps selected from a wafer manufacturing step, an oxide film forming step, a transistor forming step, a wiring forming step, and a CMP step, etc., which are known steps for manufacturing a semiconductor device.

[0150] The substrate subjected to the dry etching is a semiconductor wafer containing a transition metal. The transition metal film can be formed on the substrate by any method, for example, CVD, ALD, PVD, sputtering, plating, etc.

[0151] When the semiconductor wafer containing transition metals prepared by the above method is dry-etched, the dry-etching method is not particularly limited and can be performed by a known method, preferably using O 2 / Cl 2 The mixed gas performs dry etching.

[0152] The dry etching is preferably reactive ion etching. In addition, as a method for generating plasma for reactive ion etching, capacitive coupled plasma-RIE, inductive coupled plasma-RIE, and electron cyclotron resonance (ECR) are preferred.

[0153] When dry etching is performed by the above method, dry etching residues such as Si-containing residues, metal-containing residues, and residues containing organic matter derived from photoresists are generated. The residue removing liquid of the present invention is suitable for removing these dry etching residues.

[0154] (Method for removing dry etching residue from semiconductor wafer, method for cleaning semiconductor wafer)

[0155] The residue removing solution of the present invention can remove dry etching residues of a semiconductor wafer by contacting the semiconductor wafer. That is, the method for removing dry etching residues of a semiconductor wafer of the present invention includes the step of contacting the residue removing solution with the semiconductor wafer.

[0156] In addition, the dry etching residue removal method of the present invention can also be used as a semiconductor wafer cleaning method. The semiconductor wafer cleaning method also includes the step of bringing the residue removing liquid into contact with the semiconductor wafer, similarly to the dry etching residue removal method.

[0157] In the dry etching residue removal method or the semiconductor wafer cleaning method, the method of bringing the residue removal liquid into contact with the semiconductor wafer is not particularly limited, and can be appropriately selected according to the cleaning conditions of the cleaning device used and the semiconductor wafer used. Examples thereof include a method of spraying the residue removal liquid on the semiconductor wafer, a method of immersing the semiconductor wafer in a container containing the residue removal liquid, a method of dripping the residue removal liquid on the semiconductor wafer, a method of bringing the residue removal liquid into contact with the semiconductor wafer and applying ultrasonic waves to promote residue removal, and any combination thereof.

[0158] The temperature at which the residue removing liquid of the present invention is used is in the range of 10 to 80° C., preferably 20 to 70° C., and may be appropriately selected depending on the cleaning conditions of the cleaning apparatus used and the semiconductor wafer used.

[0159] The time for using the residue removing solution of the present invention is 0.1 to 120 minutes per wafer, preferably 0.5 to 60 minutes, and can be appropriately selected depending on the cleaning conditions of the cleaning apparatus used and the semiconductor wafer used.

[0160] (storage container)

[0161] The container for storing the residue removing liquid of the present invention is not particularly limited, but is preferably a container with high cleanliness from which impurities are less eluted. From the perspective of less elution of metal components, the inner surface of the container in contact with the liquid is preferably an organic polymer material. As the organic polymer material used for the inner surface of the container, vinyl chloride resin (soft and hard vinyl chloride resin), nylon resin, silicone resin, polyolefin resin (polyethylene, polypropylene), fluororesin, etc. can be used. Among them, polyolefin resin or fluororesin is preferred in view of ease of molding, solvent resistance, less elution of impurities, etc.

[0162] Example

[0163] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0164] (Manufacturing of semiconductor devices)

[0165] First, a substrate made of silicon is prepared. The prepared substrate is oxidized to form a 500nm silicon oxide film on the silicon. Then, an interlayer insulating film made of a low dielectric constant (Low-k) film is formed to form a 50nm thick film, a photoresist film is formed on the interlayer insulating film, and a through hole is formed in the interlayer insulating film. A 20nm thick ruthenium film is formed in the formed through hole.

[0166] The object to be processed (semiconductor substrate) on which the ruthenium film was formed by the above method was subjected to dry etching using a reactive ion etching apparatus (RIE-400IPC manufactured by Samco Corporation).

[0167] The dry-etched object was cut into pieces of 10×20 mm. 60 mL of dry-etching residue removal solution was prepared in a fluororesin container with a lid (AsOne, PFA container 94.0 mL). The dry-etched object prepared by the above method was immersed in the dry-etching residue removal solution at 30° C. for 1 minute.

[0168] 60 mL of ultrapure water was prepared in a fluororesin container with a lid (manufactured by AsOne, PFA container 94.0 mL). The semiconductor wafer after the dry etching residue removal treatment prepared by the above method was immersed in the ultrapure water at 30° C. for 1 minute.

[0169] Dry nitrogen gas is blown to the semiconductor object to be processed obtained by the above method, thereby removing ultrapure water.

[0170] (Evaluation of dry etching residue removal rate using residue removing liquid)

[0171] Use a transmission electron microscope (TEM) to observe the object after dry etching produced by the above method. Count the number of dry etching residues α from the obtained image. Next, prepare 60 mL of dry etching residue removing solution in a fluororesin container with a lid (manufactured by AsOne, PFA container 94.0 mL). Immerse the object produced by the above method in the dry etching residue removing solution at 30°C for 1 minute. Next, use TEM to observe the object treated by dry etching residue removal. Count the number of dry etching residues β from the obtained image. Based on the number of dry etching residues α and β obtained by the observation, the residue removal rate X (%) is calculated by the formula X = (α-β) / α×100, and evaluated according to the following criteria. Evaluations A to C are all acceptable levels, and evaluation D is an unacceptable level.

[0172] evaluate:

[0173] A: More than 90%

[0174] B: 70% or more and less than 90%

[0175] C: 50% or more and less than 70% (tolerable level)

[0176] D: less than 50%

[0177] (RuO 4 Quantitative analysis of gases

[0178] RuO 4 The amount of gas generated was measured using ICP-OES. 5 mL of dry etching residue removal solution was taken into a sealed container, and a 10×20 mm ruthenium film with a film thickness of 120 nm was immersed at 30°C until the ruthenium was completely dissolved. Then, air was introduced into the sealed container, and the gas phase in the sealed container was blown into a container containing an absorption liquid (1 mol / L NaOH), and the RuO generated during the immersion was removed. 4 The gas was captured in the absorption liquid. The sheet resistance before and after immersion was measured using a four-probe resistance meter (Loresta-GP, manufactured by Mitsubishi Chemical Analytech) and converted to film thickness, thereby confirming that all ruthenium on the Si wafer immersed in the dry etching residue removal solution was dissolved. The amount of ruthenium in the absorption liquid was measured using ICP-OES (iCAP6500 DUO, manufactured by Thermo Fisher Scientific) and converted to RuO 4 The gas volume was evaluated according to the following criteria: Evaluations A to C were all acceptable levels, and evaluation D was an unacceptable level.

[0179] evaluate:

[0180] A: <5 μg / cm2

[0181] B: 5μg / cm 2 Above and less than 10μg / cm 2

[0182] C: 10 μg / cm 2 ~40 μg / cm 2 Below (allowable level)

[0183] D:>40μg / cm 2

[0184] (Evaluation of Storage Stability of Oxidant in Residue Removing Liquid)

[0185] The storage stability of the oxidant in the residue removal solution was evaluated using an ultraviolet visible spectrophotometer (UV-2600, manufactured by Shimadzu Corporation). 5L of the dry etching residue removal solution was prepared in a light-shielding clean bottle (Pure Bottle) (manufactured by KODAMA PLASTICS Co., Ltd., PFA container 5L) and stored at 25°C while shielding from light. Then, the oxidant concentration in the dry etching residue removal solution was measured regularly for 6 months using an ultraviolet visible spectrophotometer (UV-2600, manufactured by Shimadzu Corporation). The oxidant concentration just after manufacture was set to 100%, and the oxidant concentration in the dry etching residue removal solution after 6 months was evaluated according to the following criteria. Evaluations A to C are all acceptable levels, and evaluation D is an unacceptable level.

[0186] evaluate:

[0187] A: More than 95%

[0188] B: 90% or more and less than 95%

[0189] C: 85% or more and less than 90% (tolerable level)

[0190] D: less than 85%

[0191] (Evaluation of surface smoothness after etching)

[0192] Prepare 60mL of dry etching residue removal solution in a fluororesin container with a lid (AsOne company, PFA container 94.0mL), immerse the processed object before the dry etching treatment made by the above method in the dry etching residue removal solution at 30°C for 1 minute, and etch. Then, observe the ruthenium surface before and after etching using a field emission scanning electron microscope (JSM-7800F Prime, Japan Electronics Co., Ltd.), confirm whether the surface is rough, and evaluate according to the following criteria. In order of less surface roughness, A to D, evaluation A to C are all acceptable levels, and evaluation D is unacceptable.

[0193] A: No surface roughness was observed

[0194] B: Some surface roughness observed

[0195] C: The surface is rough but the roughness is shallow

[0196] D: The surface is rough and deep.

[0197] (Manufacturing of residue removing liquid)

[0198] In a 2 L glass three-necked flask (manufactured by Cosmos Bead Co., Ltd.), 209 g of a 25 mass % aqueous solution of tetramethylammonium hydroxide and 791 g of ultrapure water were mixed to obtain a CO 2 The content of the tetramethylammonium hydroxide aqueous solution was 0.5 ppm, 5.2 mass %. The pH at this time was 13.8.

[0199] Next, a rotor (manufactured by AsOne, total length 30 mm × diameter 8 mm) was placed in the three-necked flask, a thermometer protection tube (manufactured by Cosmos Bead, bottom seal type) and a thermometer were placed in one opening, and a chlorine gas bottle and a nitrogen gas bottle were connected to the other opening, so that the tip of a PFA tube (manufactured by FLON INDUSTRY, F-8011-02) capable of switching the state of chlorine gas / nitrogen gas at will was immersed in the bottom of the solution, and the remaining opening was connected to a gas cleaning bottle (manufactured by AsOne, gas cleaning bottle, model 2450 / 500) filled with a 5 mass % sodium hydroxide aqueous solution. Next, nitrogen gas with a carbon dioxide concentration of less than 1 ppm was introduced from the PFA tube at a rate of 0.289 Pa·m 3 / sec (at 0°C) for 20 minutes, thereby discharging carbon dioxide in the gas phase. At this time, the carbon dioxide concentration in the gas phase was 1 ppm or less.

[0200] Then, a magnetic stirrer (AsOne, C-MAG HS10) was placed at the bottom of the three-necked flask and rotated and stirred at 300 rpm. The outer periphery of the three-necked flask was cooled with ice water and the pressure was maintained at 0.059 Pa·m 3 Chlorine gas (manufactured by Fujiox Co., Ltd., with a standard purity of 99.4%) was supplied at 1 / sec (at 0°C conversion) for 180 minutes to obtain a mixed solution of an aqueous solution of tetramethylammonium hypochlorite (oxidant; equivalent to 3.51 mass %, 0.28 mol / L) and tetramethylammonium hydroxide (equivalent to 0.09 mass %, 0.0097 mol / L). At this time, the liquid temperature during the reaction was 11°C.

[0201] Then, 0.1 g of an aqueous sodium hydroxide solution (0.1 mol / L, Wako Pure Chemical Industries, Ltd.) was weighed in a 100 ml PFA bottle (AsOne, ACPFA100-N) and diluted to 100 ml. Furthermore, 0.1 g of the dilution obtained by the above operation was weighed in a 100 ml PFA bottle (AsOne, ACPFA100-N) and diluted to 100 ml. Thus, a metal-containing liquid was obtained.

[0202] The tetramethylammonium hypochlorite solution obtained by the above operation, ultrapure water, onium salt, tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), hydrochloric acid, and the metal-containing solution obtained by the above operation were added and mixed so as to have the concentrations described in Tables 1 to 3, thereby obtaining residue removing solutions having the compositions described in Examples 19 to 29 and 40 to 42. It should be noted that the metal contained in the residue removing solution is the metal described in the metal contained in the above dry etching residue removing solution, and the metal concentration in the residue removing solution is the concentration calculated from the total content of Mg, Ca, Na, and K contained in the residue removing solution.

[0203] 0.04 g of the tetramethylammonium hypochlorite solution obtained by the above operation, 0.01 g of tetramethylammonium bromide (97% by mass, manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of (1-ethoxy-1-oxopropane-2-yl)triphenylphosphonium bromide (98% by mass, manufactured by Tokyo Chemical Industry Co., Ltd.), 1.14 g of tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), and 1.74 g of the metal-containing liquid obtained by the above operation were added to 97.02 g of ultrapure water and mixed to obtain a residue removing liquid having the composition described in Example 1. Examples 2 to 12 and 36 to 38 were also prepared and evaluated by the same method. It should be noted that the metal contained in the residue removing liquid is the metal described in the metal contained in the above dry etching residue removing liquid, and the metal concentration in the residue removing liquid is the concentration calculated from the total content of Mg, Ca, Na and K contained in the residue removing liquid.

[0204] 200 mL of a strongly acidic ion exchange resin (Amberlite IR-120BNa, manufactured by ORGANO CORPORATION) was placed in a glass column with an inner diameter of 45 mm (manufactured by AsOne). Then, 1 L of 1N hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd., for volumetric analysis) was passed through the ion exchange resin column to exchange it into the hydrogen form, and 1 L of ultrapure water was passed through the ion exchange resin column to wash the ion exchange resin. Furthermore, 2 L of a 2.38% tetramethylammonium hydroxide solution was passed through the ion exchange resin exchanged into the hydrogen form to exchange ions from the hydrogen form to the tetramethylammonium form. After the ion exchange, 1 L of ultrapure water was passed through the ion exchange resin to wash the ion exchange resin.

[0205] Commercially available sodium bromite is added to ultrapure water to obtain a sodium bromite solution, and the sodium bromite solution is passed through an ion exchange resin that has been ion-exchanged to a tetramethylammonium type to replace sodium ions with tetramethylammonium ions, thereby obtaining a tetramethylammonium bromite solution.

[0206] Ultrapure water, tetramethylammonium bromide solution, onium salt, tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), hydrochloric acid, and the metal-containing solution obtained by the above operation were added and mixed in such a manner as to have the concentrations described in Tables 1 and 3, thereby obtaining residue removing solutions having the compositions described in Examples 13 to 15 and 39. It should be noted that the metals contained in the residue removing solution are the metals described in the metals contained in the above-mentioned dry etching residue removing solution, and the metal concentration in the residue removing solution is the concentration calculated from the total content of Mg, Ca, Na, and K contained in the residue removing solution.

[0207] Commercially available sodium bromate is added to ultrapure water to obtain a sodium bromate solution, and the sodium bromate solution is passed through an ion exchange resin that has been ion-exchanged to a tetramethylammonium type to replace sodium ions with tetramethylammonium ions, thereby obtaining a tetramethylammonium bromide solution.

[0208] Ultrapure water, tetramethylammonium bromide solution, onium salt, tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), hydrochloric acid, and the metal-containing solution obtained by the above operation were added and mixed so as to have the concentrations described in Table 1, thereby obtaining residue removing solutions having the compositions described in Examples 16 to 18. It should be noted that the metals contained in the residue removing solution are the metals described in the metals contained in the above dry etching residue removing solution, and the metal concentration in the residue removing solution is the concentration calculated from the total content of Mg, Ca, Na, and K contained in the residue removing solution.

[0209] Commercially available sodium chlorite is added to ultrapure water to obtain a sodium chlorite solution, and the sodium chlorite solution is passed through an ion exchange resin that has undergone ion exchange to a tetramethylammonium type to replace sodium ions with tetramethylammonium ions, thereby obtaining a tetramethylammonium chlorite solution.

[0210] Ultrapure water, tetramethylammonium chlorite solution, onium salt, tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), hydrochloric acid, and the metal-containing liquid obtained by the above operation were added and mixed in such a manner as to have the concentrations described in Table 2, thereby obtaining residue removing liquids having the compositions described in Examples 37 to 39. It should be noted that the metals contained in the residue removing liquids are the metals described in the metals contained in the above-mentioned dry etching residue removing liquids, and the metal concentrations in the residue removing liquids are the concentrations calculated from the total contents of Mg, Ca, Na, and K contained in the residue removing liquids.

[0211] Commercially available sodium chlorate is added to ultrapure water to obtain a sodium chlorate solution, and the sodium chlorate solution is passed through an ion exchange resin that has been ion-exchanged to a tetramethylammonium type to replace sodium ions with tetramethylammonium ions, thereby obtaining a tetramethylammonium chlorate solution.

[0212] Ultrapure water, tetramethylammonium chlorate solution, onium salt, tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), hydrochloric acid, and the metal-containing solution obtained by the above operation were added and mixed so as to have the concentrations described in Tables 2 and 3, thereby obtaining residue removing solutions having the compositions described in Examples 33 to 35 and 43. It should be noted that the metals contained in the residue removing solution are the metals described in the metals contained in the above-mentioned dry etching residue removing solution, and the metal concentration in the residue removing solution is the concentration calculated from the total content of Mg, Ca, Na, and K contained in the residue removing solution.

[0213] An equimolar amount of tetramethylammonium bromide was added to the tetramethylammonium hypochlorite solution obtained by the above operation to obtain a tetramethylammonium hypobromite solution. The tetramethylammonium hypochlorite solution obtained by the above operation, the tetramethylammonium bromide solution, the tetramethylammonium chlorate solution, the onium salt, the tetramethylammonium hydroxide (25% by mass, manufactured by Tokuyama Corporation), the hydrochloric acid, and the metal-containing liquid obtained by the above operation were added to the tetramethylammonium hypobromite solution in a manner to obtain the concentrations described in Table 4, and the mixture was mixed to obtain a residue removing liquid having the composition described in Examples 44 to 46. It should be noted that the metal contained in the residue removing liquid is the metal described in the metal contained in the above dry etching residue removing liquid, and the metal concentration in the residue removing liquid is the concentration calculated from the total content of Mg, Ca, Na and K contained in the residue removing liquid.

[0214] (Measurement of Metal Amount in Treatment Liquid)

[0215] The amount of metal was measured using a triple quadrupole inductively coupled plasma mass spectrometer (ICP-8900, manufactured by Agilent Technologies, Inc.) A calibration curve was prepared using element standard solutions for ICP analysis containing Mg, Ca, Na, K, Fe, Cr, Ni, Zn, Cu, and Al, and the metal concentration in the treatment solution was measured.

[0216] (evaluate)

[0217] The residue removal rate of dry etching residue and RuO 4 Evaluation of the amount of gas generated, the stability of the oxidant concentration in the residue removing solution, and the surface smoothness after etching.

[0218] Tables 1 to 4 show the compositions of the residue removing liquids and the evaluation results.

[0219] (Onium salt)

[0220] A: benzyldimethylphenylammonium ion

[0221] B: (1-ethoxy-1-oxopropan-2-yl)triphenylphosphonium ion

[0222] C: 1,1'-(Decane-1,10-diyl)bis[4-aza-azoniabicyclo[2.2.2]octane] diion

[0223] D: Butyltriphenylphosphonium ion

[0224] E: (2-carboxyethyl)triphenylphosphonium ion

[0225] F: (3-carboxypropyl)triphenylphosphonium ion

[0226] G: (4-carboxybutyl)triphenylphosphonium ion

[0227] H: Allyltriphenylphosphonium ion

[0228] I: Tetraphenylphosphonium ion

[0229] J: benzyltriphenylphosphonium ion

[0230] [Table 1]

[0231]

[0232] Note: Metal concentration is the concentration calculated from the total amount of Mg, Ca, Na and K.

[0233] [Table 2]

[0234]

[0235] Note: Metal concentration is calculated from the total content of Mg, Ca, Na and K.

[0236] [Table 3]

[0237]

[0238] Note: Metal concentration is calculated from the total content of Mg, Ca, Na and K.

[0239] [Table 4]

[0240]

[0241] Note: Metal concentration is calculated from the total content of Mg, Ca, Na and K.

Claims

1. A dry etching residue removing liquid, which is a dry etching residue removing liquid for removing residues after dry etching, It contains: one or more oxidants selected from the group consisting of hypobromite ion, bromate ion, bromite ion, hypochlorite ion, chlorate ion and chlorite ion; one or more metals selected from the group consisting of Mg, Ca, Na and K; and water, The pH of the residue removing solution is 9.5 or more and 14 or less at 25° C., and the total content of Mg, Ca, Na, and K in the dry etching residue removing solution is 0.01 ppt or more and 1000 ppt or less.

2. The dry etching residue removing solution according to claim 1, wherein: The concentration of the oxidant is greater than or equal to 0.0001 mol / L and less than or equal to 0.40 mol / L.

3. The dry etching residue removing solution according to claim 1, wherein: The oxidant is hypochlorite ions, and the concentration of the hypochlorite ions is greater than or equal to 0.001 mol / L and less than or equal to 0.40 mol / L.

4. The dry etching residue removing solution according to claim 2, wherein: The oxidant is a hypobromite ion, and the concentration of the hypobromite ion is greater than or equal to 0.001 mol / L and less than or equal to 0.20 mol / L. 5 . The dry etching residue removing liquid according to claim 1 , further comprising onium ions, wherein the surface tension of the residue removing liquid is 60 mN / m or more and 75 mN / m or less.

6. The dry etching residue removing solution according to claim 5, wherein: The onium ion is one or more selected from the group consisting of onium ions represented by formula (1) to formula (6), In formula (1) to formula (6), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are independently an alkyl group having 2 to 9 carbon atoms, an allyl group, an aralkyl group having an alkyl group having 1 to 9 carbon atoms, or an aryl group, and at least one hydrogen atom in the ring of the aryl group or the ring of the aryl group in the aralkyl group is optionally substituted with fluorine, chlorine, an alkyl group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkenyloxy group having 2 to 9 carbon atoms, and at least one hydrogen atom in these groups is optionally substituted with fluorine, chlorine, bromine or iodine, A is an ammonium ion or a phosphonium ion, Z is an aromatic group or an alicyclic group optionally containing nitrogen, sulfur or oxygen atoms, in which carbon or nitrogen optionally has chlorine, bromine, fluorine, iodine, at least one alkyl group having 1 to 9 carbon atoms, at least one alkenyloxy group having 2 to 9 carbon atoms, at least one aromatic group optionally substituted with an alkyl group having 1 to 9 carbon atoms, or at least one alicyclic group optionally substituted with an alkyl group having 1 to 9 carbon atoms, R is chlorine, bromine, fluorine, iodine, an alkyl group having 1 to 9 carbon atoms, an allyl group, an aromatic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms, or an alicyclic group optionally substituted with at least one alkyl group having 1 to 9 carbon atoms, n is an integer of 1 or 2, indicating the number of R, when n is 2, R may be the same or different, and may form a ring, a is an integer from 1 to 10.

7. The dry etching residue removing solution according to claim 5 or 6, wherein: The onium ion concentration is 1 mass ppm or more and 10000 mass ppm or less. 8 . A method for removing dry etching residue from a semiconductor wafer, comprising the step of bringing the dry etching residue removing solution according to claim 1 into contact with a semiconductor wafer.

9. A method for manufacturing a semiconductor device, comprising: The process of dry etching semiconductor wafers; and a step of removing the dry etching residue using the dry etching residue removing solution according to any one of claims 1 to 7.

10. The method for manufacturing a semiconductor device according to claim 9, wherein: The semiconductor wafer is a semiconductor wafer containing ruthenium-based metals.

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