Cleaning liquid composition

Abstract

The problem addressed by the present invention is to provide a cleaning liquid composition that can favorably clean residue after CMP, such as organic residue that includes slurry-derived abrasive grains or molybdenum (Mo), on both molybdenum (Mo)-containing films and insulating films of substrates that comprise the molybdenum (Mo)-containing films and the insulating films.　The present invention is a cleaning liquid composition for cleaning a substrate that comprises a molybdenum (Mo)-containing film and an insulating film, wherein: the cleaning composition includes one or more types of reducing agents, two or more types of surfactants, and water; and at least one type of the surfactant is a polycarboxylic compound that has a pH of 7 or less.

Description

Cleaning composition

[0001] The present invention relates to a cleaning liquid composition used for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film.

[0002] In recent years, with the advancement of miniaturization of devices and the development of multilayer wiring structures, there has been a demand for more precise planarization of substrate surfaces at each stage of semiconductor substrate manufacturing. To address this demand, a new technology called chemical mechanical polishing (CMP) has been introduced. This involves pressing a wafer against an abrasive cloth called a buff while supplying a slurry mixture of abrasive particles and chemicals, and then rotating the buff to combine chemical and physical actions to polish and planarize insulating films and metal materials.

[0003] Chemical mechanical polishing (CMP) is performed using a slurry containing abrasive particles made of silicon compounds such as alumina and silicon oxide, or cerium compounds such as cerium oxide. After chemical mechanical polishing (CMP), the substrate surface is contaminated by particles, typically alumina, silica, or cerium oxide particles, contained in the slurry, as well as metal impurities derived from the constituent materials of the surface being polished and the chemicals contained in the slurry. These post-CMP residues can cause pattern defects, poor adhesion, and poor electrical properties, and therefore must be completely removed before the next process.

[0004] Conventionally, tungsten (W) has been used for contact plugs that raise electrodes such as the gate, source, and drain of transistors above the insulating film, but as wiring becomes finer, problems such as increased wiring resistance and wiring defects due to electromigration (EM) have emerged. For advanced devices, molybdenum (Mo), which has a high melting point, high EM resistance, and low resistance, is being considered as an alternative material to tungsten (W).

[0005] When a chemical mechanical polishing (CMP) process is performed after embedding molybdenum (Mo) wiring, post-CMP residues, such as abrasive particles from the slurry and organic residues containing molybdenum (Mo), remain on the wafer surface. Because these post-CMP residues, such as remaining abrasive particles, can cause wiring defects, they are removed in a post-CMP (p-CMP) cleaning process. Furthermore, the surface after cleaning must be highly clean, and deformation due to corrosion of the molybdenum (Mo) wiring must be minimized.

[0006] Patent Document 1 discloses a cleaning liquid composition used for treating a molybdenum-containing substrate, which contains an organic acid and two or more organic amine compounds.

[0007] International Publication No. WO2023 / 189432A1

[0008] In one embodiment, a substrate using molybdenum (Mo) wiring is manufactured by the following procedure: (1) forming a transistor on a substrate; (2) forming an insulating film thereon; (3) dry-etching the insulating film down to each electrode of the transistor to form contact holes; (4) forming a molybdenum (Mo) film by a method such as chemical vapor deposition (CVD); and (5) polishing the excess portion of the molybdenum (Mo) film to the height of the insulating film by chemical mechanical polishing (CMP). The present inventors have found that in the chemical mechanical polishing (CMP) step (5), post-CMP residues such as abrasive particles derived from the slurry and organic residues containing molybdenum (Mo) remain on the surface of a substrate having a molybdenum (Mo)-containing film and an insulating film, and that when such a substrate is washed, the cleanability differs between the molybdenum (Mo)-containing film and the insulating film. The present inventors have conducted research aimed at providing a cleaning solution composition that effectively removes post-CMP residues, such as abrasive particles derived from a slurry and organic residues containing molybdenum (Mo), not only from molybdenum (Mo)-containing films but also from insulating films. That is, an object of the present invention is to provide a cleaning solution composition that effectively removes post-CMP residues, such as abrasive particles derived from a slurry and organic residues containing molybdenum (Mo), from both a molybdenum (Mo)-containing film and an insulating film on a substrate having the molybdenum (Mo)-containing film and the insulating film ( FIG. 1 ).

[0009] The present inventors have conducted extensive research to solve the above problems, and have found that a cleaning liquid composition containing one or more reducing agents, two or more surfactants, and water, wherein at least one of the surfactants is a polycarboxylic acid compound, and having a pH of 7 or less, can effectively remove post-CMP residues, such as abrasive grains derived from the slurry and organic residues containing molybdenum (Mo), from both molybdenum (Mo)-containing films and insulating films. As a result of further research, the present inventors have completed the present invention.

[0010] That is, the present invention relates to the following: [1] A cleaning liquid composition for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, the cleaning liquid composition comprising one or more reducing agents, two or more surfactants, and water, wherein at least one of the surfactants is a polycarboxylic acid compound, and the cleaning liquid composition has a pH of 7 or less. [2] The cleaning liquid composition according to [1] above, wherein the polycarboxylic acid compound is a polyacrylic acid compound. [3] The cleaning liquid composition according to [1] or [2] above, wherein at least one of the surfactants is a polysulfonic acid compound.

[0011] [4] The cleaning liquid composition according to any one of [1] to [3] above, wherein the reducing agent is selected from the group consisting of hydroxylamine derivatives, gallic acid, ascorbic acid, and pyrogallol. [5] The cleaning liquid composition according to [4] above, wherein the hydroxylamine derivative is selected from the group consisting of N,N-diethylhydroxylamine, N-methylhydroxylamine, and N,N-dimethylhydroxylamine. [6] The cleaning liquid composition according to any one of [1] to [5] above, further comprising one or more pH adjusters.

[0012] [7] The cleaning liquid composition according to [6], wherein the pH adjuster is a quaternary ammonium compound or an inorganic acid. [8] The cleaning liquid composition according to [7], wherein the quaternary ammonium compound is trimethyl-2-hydroxyethylammonium hydroxide. [9] The cleaning liquid composition according to [7], wherein the inorganic acid is selected from the group consisting of nitric acid, sulfuric acid, hydrofluoric acid, and hydrochloric acid.

[0013]

[10] The cleaning liquid composition according to any one of [1] to [9] above, further comprising one or more anticorrosive agents.

[11] The cleaning liquid composition according to

[10] above, wherein the anticorrosive agent is a nitrogen-containing ring compound or a thiol compound.

[12] The cleaning liquid composition according to

[11] above, wherein the nitrogen-containing ring compound is selected from the group consisting of 1,2,4-triazole, 3-mercapto-1,2,4-triazole, and bismuthiol.

[13] The cleaning liquid composition according to

[11] above, wherein the thiol compound is cysteine ​​or thiosalicylic acid.

[0014]

[14] The cleaning liquid composition according to any one of [1] to

[13] above, wherein the insulating film is a tetraethoxysilane (TEOS) film or a silicon nitride (SiN) film.

[15] The stock solution composition for the cleaning liquid composition according to any one of [1] to

[14] above, which is used to obtain the cleaning liquid composition by diluting it 10 to 1000 times.

[16] A method for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, comprising the step of contacting the cleaning liquid composition according to any one of [1] to

[14] above with the substrate having the molybdenum (Mo)-containing film and the insulating film.

[0015]

[17] A method for producing a semiconductor substrate, comprising a step of contacting a substrate having a molybdenum (Mo)-containing film and an insulating film with the cleaning liquid composition according to any one of [1] to

[14] above.

[18] A method for producing a semiconductor substrate according to

[17] above, comprising a step of chemically mechanically polishing (CMP) the substrate having a molybdenum (Mo)-containing film and an insulating film before the step of contacting the substrate having a molybdenum (Mo)-containing film and an insulating film.

[19] A method for producing a semiconductor substrate according to

[17] or

[18] above, wherein the step of contacting the substrate having a molybdenum (Mo)-containing film and an insulating film is a step of cleaning the substrate having a molybdenum (Mo)-containing film and an insulating film.

[0016] The cleaning solution composition of the present invention can effectively remove metal impurities and fine particles, particularly abrasive grains derived from the slurry, and post-CMP residues such as organic residues containing molybdenum (Mo), in a short time when cleaning metal materials such as molybdenum (Mo) and insulating film surfaces on substrates subjected to polishing, etching, chemical mechanical polishing (CMP), etc., in the manufacturing process of electronic devices such as semiconductor elements. Furthermore, when the reducing agent is a hydroxylamine derivative, the cleaning solution composition of the present invention exhibits high pH stability over time. By further containing an anticorrosion agent, the cleaning solution composition of the present invention can inhibit corrosion of metal materials such as molybdenum (Mo) on substrates having a molybdenum (Mo)-containing film and insulating film.

[0017] Fig. 1 is a diagram showing the state before and after cleaning of a substrate having a Mo-containing film and an insulating film. Fig. 2 is a diagram showing the cleaning performance of the cleaning liquid compositions of Comparative Examples 1 to 3 and Example 1 for removing post-CMP residues on a Mo chip and the solubility of Mo. Fig. 3 is a diagram showing the cleaning performance of the cleaning liquid compositions of Comparative Example 3 and Example 1 for removing post-CMP residues on a substrate having a TEOS film or a substrate having a silicon nitride film.

[0018] The present invention will be described in detail below based on preferred embodiments of the present invention.

[0019] The present invention relates to a cleaning liquid composition for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, the cleaning liquid composition comprising one or more reducing agents, two or more surfactants, and water, wherein at least one of the surfactants is a polycarboxylic acid compound, and the cleaning liquid composition has a pH of 7 or less.

[0020] The reducing agent used in the present invention is not particularly limited, but examples thereof include hydroxylamine derivatives, gallic acid, ascorbic acid, and pyrogallol.

[0021] Hydroxylamine derivatives include hydroxylamine (NH ２ Hydroxylamine derivatives are compounds in which one or two hydrogen atoms (H) bonded to nitrogen atoms (N) in the hydroxylamine (NH OH) are substituted with alkyl groups, preferably alkyl groups having 1 to 2 carbon atoms. ２Hydroxylamine derivatives are more stable than hydroxylamine derivatives (OH). Hydroxylamine derivatives have the property of increasing reactivity through the formation of a complex with a metal (ion). In other words, in a cleaning solution composition for molybdenum (Mo), the reactivity is selectively increased at the interface between molybdenum (Mo) and the cleaning solution composition, resulting in reduction. Therefore, the cleaning solution composition of the present invention containing the hydroxylamine derivative maintains high stability while exhibiting excellent reduction at the interface between molybdenum (Mo) and the cleaning solution composition during use, thereby achieving effective cleaning. Examples of hydroxylamine derivatives include N,N-diethylhydroxylamine, N-methylhydroxylamine, and N,N-dimethylhydroxylamine, with N,N-diethylhydroxylamine being preferred.

[0022] In one embodiment, the reducing agent is selected from the group consisting of hydroxylamine derivatives, gallic acid, ascorbic acid, and pyrogallol. From the viewpoint of pH stability, the reducing agent is preferably a hydroxylamine derivative. One or more reducing agents can be used. The concentration of the reducing agent in the cleaning solution composition is not limited thereto, but is preferably 0.1 mM to 100 mM, and particularly preferably 1 mM to 10 mM. In one embodiment, the cleaning solution composition of the present invention does not contain gallic acid.

[0023] The cleaning liquid composition of the present invention contains two or more surfactants, and by containing two or more surfactants, the cleaning liquid composition of the present invention can effectively remove post-CMP residues, such as abrasive grains derived from the slurry and organic residues containing molybdenum (Mo), from a substrate having a molybdenum (Mo)-containing film and an insulating film.

[0024] At least one surfactant is a polycarboxylic acid compound. By including a polycarboxylic acid compound, the cleaning liquid composition of the present invention can more effectively remove post-CMP residues, such as abrasive grains derived from the slurry and organic residues containing molybdenum (Mo), particularly from substrates having an insulating film. The polycarboxylic acid compound is not particularly limited as long as it is a polymeric compound having a repeating unit containing a carboxy group, and may also contain other acid groups such as sulfo groups and hydroxy groups. Examples of polycarboxylic acid compounds include polyacrylic acid compounds, polymaleic acid compounds, polymethacrylic acid compounds, and salts thereof. From the viewpoint of removing post-CMP residues from substrates having an insulating film, polyacrylic acid compounds or salts thereof are preferred. The weight-average molecular weight of the polycarboxylic acid compound is 1,000 to 10,000, preferably 3,000 to 5,000. One or more polycarboxylic acid compounds may be included. The concentration of the polycarboxylic acid compound in the cleaning liquid composition is not limited thereto, but is preferably 1 ppm to 1,000 ppm, and particularly preferably 50 ppm to 300 ppm.

[0025] The polyacrylic acid compound is not particularly limited as long as it is a polymer compound having a repeating unit containing an acrylic acid group. It may be a polymer obtained by polymerizing a single monomer containing an acrylic acid group, or a copolymer obtained by polymerizing one or more monomers containing an acrylic acid group with one or more monomers containing an acid group other than an acrylic acid group. A polymer obtained by polymerizing a single monomer containing an acrylic acid group is polyacrylic acid. Examples of acid groups other than an acrylic acid group include methacrylic acid groups, sulfonic acid groups, and maleic acid groups. In the case of a copolymer obtained by polymerizing one or more monomers containing an acrylic acid group with one or more monomers containing an acid group other than an acrylic acid group, the molar ratio of the one or more monomers containing an acrylic acid group to the one or more monomers containing an acid group other than an acrylic acid group is not particularly limited, but may be, for example, 1:1 to 4:1. The polyacrylic acid compound is preferably polyacrylic acid.

[0026] The surfactant other than the polycarboxylic acid compound is appropriately selected depending on the particulate matter and substrate to be removed, and is not particularly limited. Examples include polymeric compounds having repeating units with groups selected from sulfonic acid groups, phosphonic acid groups, and sulfate ester groups, or salts thereof. Preferred are polysulfonic acid compounds, polyphosphonic acid compounds, polysulfuric acid ester compounds, and salts thereof. From the viewpoints of defoaming properties and environmental toxicity, polysulfonic acid compounds and salts thereof are particularly preferred. Examples of polysulfonic acid compounds include naphthalenesulfonic acid formaldehyde condensates, polystyrene sulfonic acid, lignin sulfonic acid, and salts thereof. Preferred is naphthalenesulfonic acid formaldehyde condensates. The concentration of the surfactant other than the polycarboxylic acid compound in the cleaning liquid composition is not limited thereto, but is preferably 1 ppm to 1000 ppm, and particularly preferably 10 ppm to 100 ppm. The concentration of the two or more surfactants (including the polycarboxylic acid compound) in the cleaning liquid composition is not limited to this, but is preferably 2 ppm to 2000 ppm, and particularly preferably 60 ppm to 400 ppm.

[0027] The cleaning liquid composition of the present invention contains water in an amount of 50 wt % or more, preferably 90 wt % or more, based on the cleaning liquid composition.

[0028] The hydrogen ion concentration (pH) of the cleaning liquid composition of the present invention is 7 or less.

[0029] In one embodiment, the cleaning liquid composition of the present invention may contain a pH adjuster. The pH adjuster is not particularly limited as long as it can adjust the pH to a predetermined level, and examples thereof include quaternary ammonium compounds, inorganic acids, potassium hydroxide, sodium hydroxide, and aqueous ammonium solutions, with quaternary ammonium compounds and inorganic acids being preferred.

[0030] Examples of quaternary ammonium compounds include, but are not limited to, tetramethylammonium hydroxide (TMAH), trimethyl-2-hydroxyethylammonium hydroxide (choline hydroxide), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylphenylammonium hydroxide, benzyltrimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, and methyltris(2-hydroxyethyl)ammonium hydroxide. Preferred are trimethyl-2-hydroxyethylammonium hydroxide (choline hydroxide), tetraethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, and methyltris(2-hydroxyethyl)ammonium hydroxide. Particularly preferred is trimethyl-2-hydroxyethylammonium hydroxide (choline hydroxide).

[0031] Examples of inorganic acids include, but are not limited to, nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid, etc., and are preferably selected from the group consisting of nitric acid, sulfuric acid, hydrofluoric acid, and hydrochloric acid, with nitric acid being particularly preferred.

[0032] The cleaning liquid composition of the present invention preferably does not contain tetramethylammonium hydroxide (TMAH), which is a quaternary ammonium compound, from the viewpoint of suppressing toxicity to the human body.

[0033] In one embodiment, the cleaning liquid composition of the present invention may contain a corrosion inhibitor. By containing the corrosion inhibitor, the cleaning liquid composition of the present invention can suppress corrosion of metal materials such as molybdenum (Mo) on a substrate having a molybdenum (Mo)-containing film and an insulating film. In particular, it is believed that the corrosion inhibitor can suppress even slight corrosion of molybdenum (Mo) that may be caused by polycarboxylic acid compounds, enabling the production of substrates with higher precision. Examples of the corrosion inhibitor include, but are not limited to, nitrogen-containing ring compounds, thiol compounds, sulfur-containing ring compounds, etc., and preferably nitrogen-containing ring compounds and thiol compounds.

[0034] Examples of the nitrogen-containing ring compound include, but are not limited to, pyrrole, pyrazoline, pyrazole, imidazole, triazole, imidazoline, oxazoline, oxazole, isoxazole and derivatives thereof, and specific examples thereof include 1H-pyrrole, 1-pyrroline, 2-pyrroline, 3-pyrroline, pyrrolidine, pyrrolidone, γ-butyrolactam, γ-valerolactam, proline, prolyl, hygric acid, hygroyl, minalin, 1H-pyrazole, 1-pyrazoline, 2-pyrazoline, pyrazolidine, pyrarizolidone, 3-pyrazolone, 4-pyrazolone, 5-pyrazolone, 1H-pyrazole-4-carboxylic acid, 1-methyl-1H-pyrazole-5-carboxylic acid, 5-methyl-1H-pyrazole-3-carboxylic acid, 3,5-pyrazoledicarboxylic acid, 3-amino-5-hydroxypyrazole, 1H-imidazole, 2-imidazoline, 3-imidazoline, 4-imidazoline, imidazolidine, imidazolidone, 1,3,4-thiadiazole , 5-mercapto-1,3,4-thiadiazole, 2-amino-5-mercapto-1,3,4-thiadiazole, bismuthiol, ethylene urea, hydantoin, allantoin, histidine, histidyl, histamine, 1,2,3-triazole, 1,2,4-triazole, 1-hydroxybenzotriazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 4-ano-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, and the like. As the nitrogen-containing ring compound, from the viewpoints of industrial availability and high water solubility, preferred are pyrazole, 3,5-pyrazoledicarboxylic acid, 3-amino-5-hydroxypyrazole, imidazole, triazole, 3-mercapto-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, histidine, and histamine, and particularly preferred are 1,2,4-triazole, 3-mercapto-1,2,4-triazole, 5-mercapto-1,3,4-thiadiazole, and bismuthiol.

[0035] Examples of thiol compounds include, but are not limited to, methanethiol, 2-aminoethanethiol, 2-mercaptoethanol, 1-thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, allyl mercaptan, propanethiol, cyclopentanethiol, 2-methyl-1-butanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, benzenethiol, 4-aminobenzenethiol, 2-hydroxybenzenethiol, thiosalicylic acid, 1,4-benzenedithiol, 2-mercaptopyridine, 2-mercaptopyrimidine, 2-mercaptopyrazine, 3-furanthiol, 2-mercaptoimidazole, 2-thiophenethiol, cyclohexanethiol, 2-mercaptothiazole, 2-mercaptothiazoline, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, cysteine, homocysteine, and N-acetylcysteine. Particularly preferred are cysteine ​​and thiosalicylic acid. Examples of sulfur-containing ring compounds include, but are not limited to, thiophene, 2-methylthiophene, 3-methylthiophene, 3-fluorothiophene, 2-aminomethylthiophene, 2-thiophenemethanol, 3-thiophenemethanol, 2-thiophenecarboxylic acid, and 3-thiophenecarboxylic acid.

[0036] The concentration of the anticorrosive agent in the cleaning liquid composition is not limited to, but is preferably 0.01 mM to 100 mM, and particularly preferably 0.1 mM to 10 mM.

[0037] In one embodiment, the cleaning liquid composition of the present invention does not contain a combination of gallic acid and cysteine.

[0038] The substrate having a molybdenum (Mo)-containing film and an insulating film in the present invention is not limited to a substrate obtained after chemical mechanical polishing (CMP), but is preferably a substrate immediately after CMP.

[0039] The chemical mechanical polishing (CMP) in the present invention can be carried out in accordance with known chemical mechanical polishing methods, and is not limited thereto, for example, silicon oxide (SiO２ ) and alumina (Al ２ O ３ ), and abrasive-less polishing method using electrolytic water. Among these, silicon oxide (SiO ２ ) and alumina (Al ２ O ３ This is a polishing method that uses abrasive grains such as

[0040] The cleaning liquid composition of the present invention can be obtained by diluting the concentrate composition of the present invention. The cleaning liquid composition of the present invention can be obtained by diluting the concentrate composition, for example, but not limited to, 10 times or more, preferably 10 to 1000 times, more preferably 50 to 200 times, and the dilution amount is appropriately determined depending on the composition of the concentrate composition.

[0041] Since the cleaning liquid composition of the present invention is mostly composed of water, when a dilution and mixing apparatus is installed in the production line of electronic devices, the cleaning liquid composition of the present invention can be supplied as an undiluted liquid composition and diluted with a diluting liquid containing water (including a diluting liquid consisting only of ultrapure water) immediately before use. This has the advantage of contributing to reduced transportation costs, reduced carbon dioxide gas emissions during transportation, and reduced production costs for electronic device manufacturers.

[0042] The cleaning liquid composition of the present invention is suitable for use with substrates having a molybdenum (Mo)-containing film and an insulating film. Examples of the molybdenum (Mo)-containing film include a molybdenum (Mo) contact plug, a molybdenum (Mo) wiring, and a molybdenum (Mo) via. The cleaning liquid composition of the present invention is suitable for use with substrates having a molybdenum (Mo)-containing film, particularly a molybdenum (Mo) contact plug and / or a molybdenum (Mo) wiring.

[0043] The insulating film may be made of tetraethoxysilane (TEOS), silicon nitride (SiN), or silicon oxide (SiO ２), low-k materials, etc. Here, the low-k material is a material having a low dielectric constant that is used for interlayer insulating films, etc., and includes, but is not limited to, porous silicon, silicon-containing organic polymers, fluorine-doped silicon oxide films (SiOF films), carbon-doped silicon oxide films, etc. Specific examples include Black Diamond (manufactured by Applied Materials, Inc.) and Aurora (manufactured by ASM International). The cleaning liquid composition of the present invention is particularly suitable for substrates having tetraethoxysilane (TEOS) or silicon nitride (SiN) as an insulating film. In one embodiment, the cleaning liquid composition of the present invention may be used for substrates that do not have copper (Cu).

[0044] The cleaning liquid composition of the present invention is also suitable for use on a substrate after chemical mechanical polishing (CMP). Here, the substrate surface after chemical mechanical polishing (CMP) contains various wirings on the substrate surface, as well as barrier metal materials (CoTi-based compounds, Ta-based compounds, Ru, etc.) and insulating film materials (TEOS, SiN, SiO ２ In addition to the low-k metals (Mo, Low-k), fine particles and metal impurities may be present in the slurry. The various wiring materials include one or more of molybdenum (Mo), cobalt (Co), copper (Cu), tungsten (W), and ruthenium (Ru).

[0045] Barrier metal materials include cobalt (Co), titanium (Ti)-based compounds, tantalum (Ta)-based compounds, ruthenium (Ru), etc., and are used in layers (barrier metal layers) formed between contact plugs or wiring on a semiconductor substrate and an insulating film to prevent the metal in the contact plugs or wiring from diffusing into the insulating film.

[0046] The fine particles are mainly, for example, alumina, silica, and cerium oxide, and the metal impurities include Mo (molybdenum) that dissolves in the slurry during polishing and re-adheres, iron (Fe) derived from the oxidizing agent in the slurry, and molybdenum (Mo) organometallic complexes formed by the reaction of molybdenum (Mo) with a molybdenum (Mo) corrosion inhibitor contained in the slurry.

[0047] The present invention also relates to a method for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, which comprises the step of contacting the substrate having the molybdenum (Mo)-containing film and the insulating film with the cleaning liquid composition of the present invention.

[0048] The present invention still further relates to a method for producing a semiconductor substrate, which comprises a step of contacting a substrate having a molybdenum (Mo)-containing film and an insulating film with the cleaning liquid composition of the present invention. In one embodiment, the method for producing a semiconductor substrate comprises a step of chemical mechanical polishing (CMP) the substrate having the molybdenum (Mo)-containing film and the insulating film before the step of contacting the substrate having the molybdenum (Mo)-containing film and the insulating film with the cleaning liquid composition of the present invention.

[0049] Examples of contacting steps include, but are not limited to, a cleaning step after chemical mechanical polishing (CMP), preferably a cleaning step after chemical mechanical polishing (CMP) after forming contact holes by dry etching and depositing a molybdenum (Mo) film. Examples of contacting methods include, but are not limited to, a single-wafer cleaning method that also uses brush scrubbing, a single-wafer cleaning method in which a cleaning solution is sprayed from a spray or nozzle, a batch spray cleaning method, and a batch immersion cleaning method. Of these, preferred are the single-wafer cleaning method that also uses brush scrubbing and the single-wafer cleaning method in which a cleaning solution is sprayed from a spray or nozzle, and particularly preferred is the single-wafer cleaning method that also uses brush scrubbing.

[0050] The atmosphere in which the contact is performed includes, but is not limited to, air, a nitrogen atmosphere, and a vacuum. Of these, air and a nitrogen atmosphere are preferred. The contact time is appropriately selected depending on the purpose and is not particularly limited. For single-wafer cleaning methods that use brush scrubbing in combination and single-wafer cleaning methods in which a cleaning solution is sprayed from a spray or nozzle, it is 0.5 to 5 minutes, and for batch-type spray cleaning and batch-type immersion cleaning methods, it is 0.5 to 30 minutes. The temperature is appropriately selected depending on the purpose and is not particularly limited. For single-wafer cleaning methods that use brush scrubbing in combination and single-wafer cleaning methods in which a cleaning solution is sprayed from a spray or nozzle, it is 20°C to 50°C, and for batch-type spray cleaning and batch-type immersion cleaning methods, it is 20°C to 100°C. The above-mentioned contact conditions can be combined appropriately depending on the purpose.

[0051] Examples of semiconductor substrates include, but are not limited to, silicon, silicon carbide, silicon nitride, gallium arsenide, gallium nitride, gallium phosphide, indium phosphide, etc. Among these, silicon, silicon carbide, gallium arsenide, and gallium nitride are preferred, and silicon and silicon carbide are particularly preferred.

[0052] Next, the cleaning liquid composition of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these.

[0053] 1. Preparation of Cleaning Liquid Compositions First, cleaning liquid compositions according to Example 1 and Comparative Examples 1 to 3 were prepared. Specifically, as shown in Table 1, the cleaning liquid compositions according to Example 1 and Comparative Examples 1 to 3 were prepared by adding and mixing a reducing agent, a surfactant (polysulfonic acid compound), a surfactant (polycarboxylic acid compound), an anticorrosive, a pH adjuster, and / or water (the balance). In Table 1, DEHA is N,N-diethylhydroxylamine, the surfactant (polysulfonic acid compound) is a naphthalenesulfonic acid formaldehyde condensate, mTAZ is 3-mercapto-1,2,4-triazole, and the surfactant (polycarboxylic acid compound) is polyacrylic acid (average molecular weight 5000, manufactured by Toagosei).

[0054] 2. Evaluation of cleaning ability of cleaning liquid composition for molybdenum (Mo) substrate 2.1. Preparation of CMP polishing liquid Hydrogen peroxide was added to a slurry using silicon oxide (W2000-V WIN, manufactured by Cabot) so that the concentration became 4.5 wt %, to obtain a CMP polishing liquid.

[0055] 2.2 Preparation of substrate to be polished A molybdenum (Mo) substrate with the following configuration was prepared (ALD-Mo 30 nm / Si, manufactured by Global Net Co., Ltd.) The molybdenum (Mo) substrate was chipped to 2.0 cm x 2.0 cm to obtain molybdenum (Mo) chips to be polished.

[0056] 2.3. Polishing and Cleaning of Molybdenum (Mo) Chips Using the above CMP polishing solution, the above molybdenum (Mo) chips to be polished were polished for 30 seconds using a polishing machine (manufactured by MAT Corporation, model number BC-15CN). After polishing, the wafer was rinsed for 10 seconds with ultrapure water (DIW) while rotating. The chips were immersed in 100 mL of each of the cleaning liquid compositions listed in Table 1, stirred at 200 rpm, and cleaned for 1 minute. The molybdenum (Mo) chips after cleaning were then rinsed with N ２ After drying by blowing, a molybdenum (Mo) chip for measurement was obtained.

[0057] 2.4. Measurement of the number of defects on the molybdenum (Mo) chip surface The number of defects on the molybdenum (Mo) chip surface for the above measurement was determined by observing the molybdenum (Mo) chip surface at 10,000x magnification using an FE-SEM (Reegulus) and counting the number of deposits observed within an area of ​​12.7 μm × 9.5 μm. The post-CMP residue removal rate was calculated using the following formula. The post-CMP residue removal rate for each cleaning composition is shown in Table 2 and Figure 2.

[0058] 3. Evaluation of Corrosivity of Cleaning Liquid Compositions to Molybdenum (Mo) 3.1. Preparation of Molybdenum (Mo) Chips A molybdenum (Mo) substrate with the following configuration was prepared (PMD-Mo 500 nm / Si, manufactured by Advanced Materials Technology Co., Ltd.). The molybdenum (Mo) substrate was chipped to 1.5 cm x 1.5 cm to obtain molybdenum (Mo) chips for evaluation. 3.2. Preparation of Evaluation Solution The molybdenum (Mo) chips for evaluation were immersed in a 1.0 mM aqueous solution of tetramethylhydroxyammonium hydroxide (TMAH) for 2 minutes and then rinsed with running ultrapure water (DIW). They were then immersed in 50 mL of each cleaning composition listed in Table 1 for 1 minute while stirring at 200 rpm. The molybdenum (Mo) chips were removed, and the cleaning compositions after immersion were used as evaluation solutions. 3.3. Measurement of Etching Rate The molybdenum (Mo) concentration in the evaluation solution was measured using an ICP-MS (Agilent, model number: 7900). The etching rate (ER) of molybdenum (Mo) was calculated from the obtained molybdenum (Mo) concentration using the following formula. The evaluation results are shown in Table 2 and Figure 2.

[0059] 4. Evaluation of cleaning properties of cleaning liquid compositions for insulating film substrates 4.1. Preparation of CMP polishing liquid Hydrogen peroxide was added to a slurry using silicon oxide (W2000-V WIN, manufactured by Cabot) so that the concentration became 4.5 wt %, thereby obtaining a CMP polishing liquid.

[0060] 4.2. Preparation of Substrate to be Polished A TEOS film substrate (plasma CVD 500 nm, manufactured by Global Net Co., Ltd.) and a silicon nitride film substrate (LP-CVD 100 nm, manufactured by Advanced Materials Technology Co., Ltd.) having the following configurations were prepared as insulating film substrates to be polished.

[0061] 4.3. Polishing and Cleaning of Insulating Film Substrates Using the above CMP polishing solution, the above TEOS film substrate and silicon nitride film substrate were each polished for 30 seconds using a polishing device (model number: Poli-762, manufactured by G&P TECHNOLOGY). After polishing was completed, brush scrubbing cleaning was performed using a cleaning device (model number: Cleaner 812L, manufactured by G&P TECHNOLOGY) using the cleaning solution composition of Example 1 or Comparative Example 3 listed in Table 1, to obtain TEOS film substrates and silicon nitride film substrates for measurement.

[0062] 4.4. Measurement of the number of defects on the surface of insulating film substrates The number of defects (0.1 μm or larger) on the TEOS film substrates and silicon nitride film substrates used for the measurements described above was counted using a surface inspection device (model number: WM-10, manufactured by Takano Corporation). The number of defects after cleaning using the cleaning composition of Example 1 or Comparative Example 3 is shown in Table 2 and Figure 3.

[0063] 5. result

[0064] 2 and 3, it was confirmed that the cleaning liquid composition of Example 1, in which at least one of the surfactants is a polycarboxylic acid compound, exhibits cleaning performance and corrosion-inhibiting performance for a molybdenum (Mo) film equivalent to those of the cleaning liquid composition of Comparative Example 3, which does not contain a polycarboxylic acid compound as a surfactant, and further exhibits cleaning performance for a TEOS film and a silicon nitride film higher than those of the cleaning liquid composition of Comparative Example 3, which does not contain a polycarboxylic acid compound as a surfactant.

Claims

1. A cleaning liquid composition for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, the cleaning liquid composition comprising one or more reducing agents, two or more surfactants, and water, wherein at least one of the surfactants is a polycarboxylic acid compound, and the cleaning liquid composition has a pH of 7 or less.

2. The cleaning liquid composition according to claim 1, wherein the polycarboxylic acid compound is a polyacrylic acid compound.

3. The cleaning liquid composition according to claim 1, wherein at least one of the surfactants is a polysulfonic acid compound.

4. The cleaning solution composition of claim 1, wherein the reducing agent is selected from the group consisting of hydroxylamine derivatives, gallic acid, ascorbic acid, and pyrogallol.

5. The cleaning liquid composition according to claim 4, wherein the hydroxylamine derivative is selected from the group consisting of N,N-diethylhydroxylamine, N-methylhydroxylamine, and N,N-dimethylhydroxylamine.

6. The cleaning liquid composition of claim 1, further comprising one or more pH adjusters.

7. The cleaning liquid composition according to claim 6, wherein the pH adjuster is a quaternary ammonium compound or an inorganic acid.

8. The cleaning composition according to claim 7, wherein the quaternary ammonium compound is trimethyl-2-hydroxyethylammonium hydroxide.

9. The cleaning solution composition of claim 7, wherein the inorganic acid is selected from the group consisting of nitric acid, sulfuric acid, hydrofluoric acid, and hydrochloric acid.

10. The cleaning solution composition of claim 1, further comprising one or more corrosion inhibitors.

11. The cleaning liquid composition according to claim 10, wherein the corrosion inhibitor is a nitrogen-containing ring compound or a thiol compound.

12. The cleaning composition according to claim 11, wherein the nitrogen-containing ring compound is selected from the group consisting of 1,2,4-triazole, 3-mercapto-1,2,4-triazole, and bismuthiol.

13. The cleaning liquid composition according to claim 11, wherein the thiol compound is cysteine ​​or thiosalicylic acid.

14. The cleaning liquid composition according to claim 1, wherein the insulating film is a tetraethoxysilane (TEOS) film or a silicon nitride (SiN) film.

15. A concentrate composition for a cleaning liquid composition according to claim 1, which is used to obtain the cleaning liquid composition by diluting it 10 to 1000 times.

16. A method for cleaning a substrate having a molybdenum (Mo)-containing film and an insulating film, comprising the step of contacting the substrate having the molybdenum (Mo)-containing film and the insulating film with the cleaning liquid composition of claim 1.

17. A method for producing a semiconductor substrate, comprising the step of contacting the cleaning liquid composition according to claim 1 with a substrate having a molybdenum (Mo)-containing film and an insulating film.

18. The method for producing a semiconductor substrate according to claim 17, further comprising chemically mechanically polishing (CMP) the substrate having the molybdenum (Mo)-containing film and insulating film prior to the step of contacting the substrate having the molybdenum (Mo)-containing film and insulating film.

19. The method for producing a semiconductor substrate according to claim 17, wherein the step of contacting the substrate having the molybdenum (Mo)-containing film and the insulating film is a step of cleaning the substrate having the molybdenum (Mo)-containing film and the insulating film.

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