Hydrogen Peroxide Decomposition Inhibitors

Abstract

The present invention aims to provide a decomposition inhibitor for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching liquid composition. The present invention relates to a decomposition inhibitor for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching liquid composition, wherein the decomposition inhibitor comprises at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds as an active ingredient.

Description

Technical Field

[0001] The present invention relates to a decomposition inhibitor of hydrogen peroxide used in an etching solution composition containing hydrogen peroxide. Background Art

[0002] Conventionally, when etching a semiconductor substrate, an etching liquid composition containing hydrogen peroxide is known as an etching liquid composition. On the other hand, in an etching liquid composition containing hydrogen peroxide, the decomposition of hydrogen peroxide is accelerated by the dissolution of metal, resulting in a problem such as a shortened life of the etching liquid composition.

[0003] In order to prevent the decomposition of hydrogen peroxide, the addition of a phosphonic acid chelating agent to an etching solution composition has been studied (Patent Document 1). In this document, a titanium (Ti)-based metal film or a tungsten (W)-based metal film is taken as an object of etching.

[0004] In addition, an etching solution composition containing hydrogen peroxide is also known for etching titanium nitride (TiN). For example, a composition containing hydrogen peroxide, an alkali, a weak acid, an ammonium salt, a triazole, a long-chain organic amine or a polyalkylamine and a solvent for selectively removing PVD titanium nitride from a semiconductor device containing PVD titanium nitride and a second material such as Cu is disclosed (Patent Document 2), but there is no discussion on preventing the decomposition of hydrogen peroxide. In this document, triazole is added as a corrosion inhibitor for preventing copper loss.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 5343858

[0008] Patent Document 2: Japanese Patent Application Publication No. 2016-213461

[0009] Summary of the Invention

[0010] Technical problem to be solved by the invention

[0011] The present inventors have encountered a problem that when using an etching liquid composition containing hydrogen peroxide, the degree of promotion of decomposition of hydrogen peroxide greatly varies depending on the raw material of the etching target. Specifically, when using an etching liquid composition containing hydrogen peroxide and etching titanium nitride used as a hard mask in semiconductor device processing, the decomposition of hydrogen peroxide in the etching liquid composition is significantly promoted compared to when etching tungsten or silver, etc. The present inventors further speculate that this problem is because the influence of components such as metal ions dissolved in the etching target in the etching liquid composition greatly varies depending on the type of the component.

[0012] Therefore, the present inventors have studied the problem of providing a decomposition inhibitor for suppressing the decomposition of hydrogen peroxide in an etching solution composition in which titanium nitride is dissolved. That is, the problem of the present invention is to provide a decomposition inhibitor for suppressing the decomposition of hydrogen peroxide contained in an etching solution composition for titanium nitride.

[0013] Technical solutions adopted to solve technical problems

[0014] After intensive studies to solve the above problems, the present inventors found that a decomposition inhibitor containing at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds as an active ingredient inhibits the decomposition of hydrogen peroxide contained in the etching solution composition for titanium nitride. When the decomposition inhibitor contains an azole compound, not only the decomposition of hydrogen peroxide is inhibited, but also the corrosion of copper (Cu) and cobalt (Co) on the semiconductor element is prevented. After further studies, the present invention was finally completed.

[0015] That is, the present invention relates to the following contents.

[0016] [1] A decomposition inhibitor for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching solution composition, comprising at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds as an active ingredient.

[0017] [2] The decomposition inhibitor according to [1] above, further comprising water.

[0018] [3] The decomposition inhibitor according to [1] or [2] above, further comprising a water-soluble organic solvent.

[0019] [4] The decomposition inhibitor according to any one of [1] to [3] above, comprising at least two compounds selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds.

[0020] [5] The decomposition inhibitor according to any one of [1] to [4] above, wherein the azole compound comprises at least one compound selected from 1,2,4-triazole, 1,2,3-triazole, imidazole and benzimidazole.

[0021] [6] The decomposition inhibitor according to any one of [1] to [4] above, wherein the aminocarboxylic acid compound comprises at least one compound selected from the group consisting of trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid and triethylenetetraaminehexaacetic acid.

[0022] [7] The decomposition inhibitor according to any one of [1] to [4] above, wherein the phosphonic acid compound comprises at least one compound selected from 1-hydroxyethane-1,1-diphosphonic acid and ethylenediaminetetramethylenephosphonic acid.

[0023] [8] The decomposition inhibitor according to any one of [1] to [7] above, wherein the decomposition inhibitor is added to the etching solution composition so that the ratio of at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds is 2 mmol / L or more relative to 100 ppm of titanium nitride in the etching solution composition.

[0024] [9] A method for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching solution composition, comprising using the decomposition inhibitor according to any one of [1] to [8] above.

[0025]

[10] A titanium nitride etching solution composition comprising the decomposition inhibitor according to any one of [1] to [8] and hydrogen peroxide.

[0026]

[11] The titanium nitride etching solution composition according to

[10] above, wherein the composition contains at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds at a ratio of 2 mmol / L or more relative to 100 ppm of titanium nitride.

[0027]

[12] The titanium nitride etching solution composition according to

[10] or

[11] , further comprising a chelating agent other than the azole compound, the aminocarboxylic acid compound and the phosphonic acid compound.

[0028]

[13] The titanium nitride etching solution composition according to any one of

[10] to

[12] above, wherein the pH is 4.0 to 8.0.

[0029] Effects of the Invention

[0030] The decomposition inhibitor of the present invention can inhibit the decomposition of hydrogen peroxide contained in the etching solution composition for titanium nitride, thereby extending the solution life of the etching solution composition.

[0031] Furthermore, when the decomposition inhibitor of the present invention contains an azole compound, it not only suppresses the decomposition of hydrogen peroxide contained in the titanium nitride etching solution composition, but also prevents corrosion of copper and cobalt on the semiconductor element, thereby enabling good processing of the semiconductor element.

[0032] Brief description of the attached figure

[0033] Figure 1 It is a figure which shows the removal of titanium nitride used as a hard mask.

[0034] Figure 2 This is a diagram showing the results of Evaluation 1.

[0035] Figure 3 This is a graph showing the results in Evaluation 2 when 1,2,4-triazole was used as the decomposition inhibitor.

[0036] Figure 4 This is a graph showing the results when CyDTA was used as the decomposition inhibitor in Evaluation 2.

[0037] Figure 5 This is a graph showing the results in Evaluation 2 when HEDP was used as the decomposition inhibitor.

[0038] Figure 6 This is a diagram showing the results of Evaluation 3.

[0039] Figure 7 This is a diagram showing the results of Evaluation 4.

[0040] Figure 8 This is a diagram showing the results of Evaluation 5.

[0041] Fig. 9 This is a graph showing the results of Evaluation 6 of the Co etching rate.

[0042] Fig.10 This is a graph showing the results of Evaluation 6 for the Cu etching rate.

[0043] Modes for Carrying Out the Invention

[0044] Hereinafter, the present invention will be described in detail based on preferred embodiments of the present invention.

[0045] The present invention relates to a decomposition inhibitor for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching solution composition, wherein the decomposition inhibitor contains at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds as an active ingredient.

[0046] The azole compound contained in the decomposition inhibitor of the present invention is not particularly limited, and examples thereof include 1,2,4-triazole, 1,2,3-triazole, imidazole, benzimidazole, benzotriazole (BTA), pyrazole, tetrazole, oxazole, thiazole, isothiazole, 5-amino-1H-tetrazole (ATZ), 3-amino-1H-1,2,4-triazole (ATA), adenine, guanine, 5-phenyltetrazole and 5-mercapto-1-methyltetrazole, among which 1,2,4-triazole, 1,2,3-triazole, imidazole and benzimidazole are preferred, and 1,2,4-triazole and 1,2,3-triazole are more preferred.

[0047] The azole compounds can be used alone or in combination. In addition, they can also be used in combination with aminocarboxylic acid compounds and / or phosphonic acid compounds as other active ingredients.

[0048] The aminocarboxylic acid compounds used in the decomposition inhibitor of the present invention are not particularly limited, and examples thereof include trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol diethyl ether diaminetetraacetic acid (GEDTA), triethylenetetraaminehexaacetic acid (TTHA), hydroxyethyliminediacetic acid (HIDA) and ethylenediamine-N,N'-disuccinic acid (EDDS), etc. Preferably, CyDTA, EDTA, DTPA, GEDTA and TTHA are used, and more preferably, CyDTA.

[0049] The aminocarboxylic acid compounds can be used alone or in combination. In addition, they can also be used in combination with other azole compounds and / or phosphonic acid compounds as active ingredients.

[0050] The phosphonic acid compound contained in the decomposition inhibitor of the present invention may be any compound having a structure derived from phosphonic acid, and examples thereof include 1-hydroxyethane-1,1-diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMP), nitrilotri(methylenephosphonic acid) (NTMP), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) and glycine-N,N-bis(methylenephosphonic acid) (glyphosphine), but are not limited thereto. HEDP and EDTMP are preferred.

[0051] The phosphonic acid compounds can be used alone or in combination, and can also be used in combination with other azole compounds and / or aminocarboxylic acid compounds as active ingredients.

[0052] In one embodiment, the decomposition inhibitor of the present invention comprises at least two compounds selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds.

[0053] The decomposition inhibitor of the present invention is preferably added to the etching solution composition in a ratio of 2 mmol / L or more of at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds relative to 100 ppm of titanium nitride in the etching solution composition, more preferably added in a ratio of 2 to 10 mmol / L relative to 100 ppm, and further preferably added in a ratio of 4 to 10 mmol / L.

[0054] The decomposition inhibitor of the present invention may further contain water.

[0055] Furthermore, when the decomposition inhibitor of the present invention further contains a water-soluble organic solvent, organic residues and the like generated during dry etching of titanium nitride can be removed, which is preferred.

[0056] The water-soluble organic solvent is not particularly limited, and examples thereof include alcohols having an ether group such as furfuryl alcohol and tetrahydrofurfuryl alcohol, glycol ethers such as methylene glycols, ethylene glycols, diethylene glycols, triethylene glycols, propylene glycols, dipropylene glycols, and tripropylene glycols, esters such as carboxylates, carbonates, lactones, phosphates, and sulfates, amides such as acetamide, N-methylacetamide, isobutylamide, propionamide, N-ethylacetamide, and N,N-dimethylacetamide, lactams such as N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone, etc. In addition, examples thereof include sulfur-containing compounds such as dimethyl sulfoxide and sulfolane.

[0057] The water-soluble organic solvents may be used alone or in combination.

[0058] The reason why the decomposition inhibitor of the present invention can inhibit the decomposition of hydrogen peroxide contained in the etching solution composition for titanium nitride is not certain, but it is considered that at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds forms a chelate together with titanium dissolved in the etching solution composition, which is dissolved in water or a water-soluble organic solvent, thereby preventing titanium from contacting with hydrogen peroxide, and the decomposition of hydrogen peroxide is inhibited.

[0059] The decomposition inhibitor of the present invention can be used to inhibit the decomposition of hydrogen peroxide contained in an etching solution composition for titanium nitride. As long as the etching solution composition contains titanium nitride, even if the etching solution composition also contains other metals such as tungsten, cobalt or copper on the device structure, the decomposition inhibitor of the present invention can inhibit the decomposition of hydrogen peroxide in the etching solution composition.

[0060] On the other hand, the decomposition inhibitor of the present invention is not suitable for inhibiting the decomposition of hydrogen peroxide in an etching solution composition containing only a metal other than titanium nitride as a metal. For example, when the etching solution composition contains only tungsten, cobalt, silver or copper on the device structure as a metal, it has no effect on inhibiting the decomposition of hydrogen peroxide.

[0061] Furthermore, the present invention also relates to a method for suppressing the decomposition of hydrogen peroxide contained in a titanium nitride etching solution composition using the decomposition inhibitor of the present invention.

[0062] The present invention also relates to a titanium nitride etching solution composition comprising the decomposition inhibitor of the present invention and hydrogen peroxide.

[0063] The titanium nitride etching solution composition of the present invention preferably contains at least one compound selected from azole compounds, aminocarboxylic acid compounds and phosphonic acid compounds at a ratio of 2 mmol / L or more relative to 100 ppm of titanium nitride, more preferably contains it at a ratio of 2 to 10 mmol / L relative to 100 ppm of titanium nitride, and further preferably contains it at a ratio of 4 to 10 mmol / L.

[0064] The titanium nitride etching solution composition of the present invention may further contain a chelating agent other than the azole compound, the aminocarboxylic acid compound and the phosphonic acid compound.

[0065] The chelating agent is not particularly limited, and examples thereof include organic acids such as glycine, malic acid, citric acid, glycolic acid, tartaric acid, and lactic acid.

[0066] Chelating agents may be used alone or in combination.

[0067] The titanium nitride etching solution composition of the present invention may further contain a pH adjuster.

[0068] As the pH adjuster, ammonia, primary amine, secondary amine, tertiary amine, quaternary ammonium hydroxide, inorganic acid, organic acid or the like is used.

[0069] The pH adjusters may be used alone or in combination.

[0070] The titanium nitride etching solution composition of the present invention may further contain a buffer for stabilizing pH.

[0071] Examples of the buffer include ammonium salts such as ammonium acetate, ammonium oxalate, ammonium citrate, ammonium tartrate, ammonium sulfate, triammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium chloride and ammonium fluoride, preferably diammonium hydrogen phosphate.

[0072] Buffers can be used alone or in combination.

[0073] The titanium nitride etching composition of the present invention may contain any additional components other than the chelating agent, pH adjuster, and pH buffer, as long as they do not hinder the inhibition of decomposition of hydrogen peroxide in the etching solution composition, and examples thereof include copper corrosion inhibitors and cobalt corrosion inhibitors. Examples of the copper corrosion inhibitor and the cobalt corrosion inhibitor include nitrogen-containing ring compounds such as 1,2,4-triazole, 1,2,3-triazole, imidazole, benzimidazole, BTA, pyrazole, tetrazole, oxazole, thiazole, isothiazole, ATZ, ATA, adenine, guanine, 5-phenyltetrazole, 5-mercapto-1-methyltetrazole, hexamethylenetetramine, 3,4-dihydro-3-hydroxy-4-oxo-1,2,4-triazine, 3H-1,2,3-triazolo[4,5-b]pyridin-3-ol, 5-amino-1H-tetrazole, 3-hydroxypyridine, and anhydrous caffeine, and BTA is more preferred.

[0074] The pH of the titanium nitride etching solution composition of the present invention is not particularly limited, but is preferably from 4.0 to 8.0, more preferably from 6.0 to 7.5, from the viewpoint of suppressing the decomposition of hydrogen peroxide in the etching solution composition.

[0075] When etching titanium nitride using the titanium nitride etching solution composition of the present invention, the temperature of the composition is preferably from 40 to 80°C, more preferably from 50 to 60°C, from the viewpoint of ensuring a high etching rate for titanium nitride. Example

[0076] Hereinafter, the etching solution composition of the present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0077] <Evaluation 1: H2O2 decomposition inhibition ability>

[0078] (Determination of H2O2 (initial))

[0079] 50 mL of a pH 6 H2O2 aqueous solution of the composition shown in Table 1 was prepared. When preparing the aqueous solution, phosphoric acid was used as a pH adjuster to lower the pH value, and tetraethylammonium hydroxide was used to increase the pH value. Then, the H2O2 concentration (initial) of the aqueous solution was measured by redox titration using potassium permanganate.

[0080] (Decomposition of H2O2)

[0081] While stirring, dissolve TiN powder in the H2O2 aqueous solution to 400 ppm and leave it at 60°C for 6 hours. As water evaporates, add water appropriately to adjust the H2O2 aqueous solution to 50 mL.

[0082] (Determination of H2O2 concentration (final))

[0083] The H2O2 concentration (final) was measured by redox titration using potassium permanganate for the H2O2 aqueous solution after standing. Then, H2O2 (final) / H2O2 (initial) × 100 [%] was calculated. The results are shown in Table 1 and Figure 2 .

[0084] [Table 1]

[0085]

[0086]

[0087] ※NMO: N-methylmorpholine N-oxide

[0088] BDG: Diethylene glycol butyl ether

[0089] PVP: Polyvinylpyrrolidone

[0090] The etching solution composition containing an azole compound, an aminocarboxylic acid compound, or a phosphonic acid compound as a decomposition inhibitor shows a good H2O2 decomposition inhibition effect compared with an etching solution composition not containing a decomposition inhibitor and an etching solution composition containing a decomposition inhibitor other than the above.

[0091] <Evaluation 2: Concentration dependence of H2O2 decomposition inhibition ability>

[0092] In Evaluation 1, the H2O2 decomposition inhibitors 1,2,4-triazole, CyDTA and HEDP, which were confirmed to have high H2O2 decomposition inhibitory ability, were evaluated for their H2O2 decomposition inhibitory ability when the concentration of each decomposition inhibitor was changed. The H2O2 concentration (initial), H2O2 decomposition and H2O2 concentration (final) were measured by the same method as Evaluation 1, except that the H2O2 aqueous solution with the composition shown in Tables 2 to 4 was used, and H2O2 (final) / H2O2 (initial) × 100 [%] was calculated. The results are shown in Tables 2 to 4 and Figures 3 to 5 .

[0093] [Table 2]

[0094]

[0095] [Table 3]

[0096]

[0097]

[0098] [Table 4]

[0099]

[0100] The etching solution composition using an azole compound, an aminocarboxylic acid compound, or a phosphonic acid compound as a decomposition inhibitor exhibits a higher H 2 O 2 decomposition inhibitory effect than the case where no decomposition inhibitor is contained, regardless of the concentration of the decomposition inhibitor.

[0101] <Evaluation 3: pH dependence of H2O2 decomposition inhibition ability>

[0102] The ability to inhibit the decomposition of H2O2 was evaluated by changing the pH in an aqueous H2O2 solution containing 1,2,4-triazole as an H2O2 decomposition inhibitor. As a pH adjuster, phosphoric acid was used when the pH was lowered, and tetraethylammonium hydroxide was used when the pH was increased. In addition to using an aqueous H2O2 solution with a pH shown in Table 5, the H2O2 concentration (initial), the decomposition of H2O2, and the H2O2 concentration (final) were measured by the same method as in Evaluation 1, and H2O2 (final) / H2O2 (initial) × 100 [%] were calculated. The results are shown in Tables 5 and Figure 6 .

[0103] [Table 5]

[0104]

[0105] The etching solution composition containing 1,2,4-triazole as a decomposition inhibitor showed a higher H 2 O 2 decomposition inhibitory effect than the etching solution composition not containing the decomposition inhibitor at any pH.

[0106] <Evaluation 4: Temperature dependence of H2O2 decomposition inhibition ability>

[0107] The ability to inhibit H2O2 decomposition when the temperature was changed in an H2O2 aqueous solution containing 1,2,4-triazole as an H2O2 decomposition inhibitor was evaluated. The H2O2 concentration (initial), H2O2 decomposition, and H2O2 concentration (final) were measured in the same manner as in Evaluation 1, except that the H2O2 aqueous solution at the temperature shown in Table 7 was used, and H2O2 (final) / H2O2 (initial) × 100 [%] was calculated. The results are shown in Tables 6 and Figure 7 .

[0108] [Table 6]

[0109]

[0110] The etching solution composition containing 1,2,4-triazole as a decomposition inhibitor showed a higher H 2 O 2 decomposition inhibitory effect than the etching solution composition not containing the decomposition inhibitor at any temperature.

[0111] <Evaluation 5: Ability to inhibit decomposition of H2O2 in H2O2 aqueous solution containing metals other than TiN>

[0112] The ability to inhibit the decomposition of H2O2 was evaluated when W, Ag or Cu was added to an aqueous H2O2 solution containing 1,2,4-triazole as a H2O2 decomposition inhibitor instead of TiN. The H2O2 concentration (initial), the decomposition of H2O2 and the H2O2 concentration (final) were measured by the same method as in Evaluation 1, except that the metals shown in Table 7 were added and 5 wt% malonic acid was added to promote the dissolution of Cu when dissolving Cu. H2O2 (final) / H2O2 (initial) × 100 [%] were calculated. The results are shown in Tables 7 and Figure 8 .

[0113] [Table 7]

[0114]

[0115] The etching solution composition containing 1,2,4-triazole as a decomposition inhibitor showed an H2O2 decomposition inhibitory effect when TiN was dissolved in the composition, but did not show an H2O2 decomposition inhibitory effect when only W, Ag or Cu was dissolved as a metal in the etching solution composition.

[0116] <Evaluation 6: Corrosion resistance of Co and Cu>

[0117] (Wafer production)

[0118] A Co film having a thickness of 40 nm was formed on a Si substrate having a diameter of 300 mm by a CVD method to obtain a Co wafer.

[0119] A Cu film having a thickness of 2000 nm was formed on a Si substrate having a diameter of 200 mm by a plating method to obtain a Cu wafer.

[0120] (Wafer Pretreatment)

[0121] Co and Cu have natural oxides on the surface, so pretreatment to remove them was performed.

[0122] Cut the Cu substrate into 1.5×1.5 cm 2 , allowed to stand in an aqueous solution of oxalic acid (1 wt %) at 25° C. for 1 minute, and rinsed with ultrapure water (DIW) for 1 minute, thereby obtaining a Cu wafer (after pretreatment).

[0123] The Co substrate was cut into 1.5 × 1.5 cm 2 , standing in an oxalic acid (10 wt %) aqueous solution at 25° C. for 10 seconds, and rinsed with ultrapure water (DIW) for 10 seconds to obtain a Co wafer (after pretreatment).

[0124] (Destructive evaluation of Co and Cu)

[0125] The Co wafer (after pretreatment) and Cu wafer (after pretreatment) were immersed in 50 mL of the etching solution composition having the composition of Table 8 and allowed to stand at 60° C. for 1 minute. Then, the wafers were taken out to obtain etching solution compositions (after Co and Cu immersion).

[0126] (Measurement of Etching Rate of Etching Solution Composition)

[0127] 1 mL of the solution was taken out from the above-mentioned etching solution composition (after Co and Cu were impregnated) and the volume was fixed to 50 mL. The concentration of Co and Cu in the etching solution composition after the volume was fixed was measured by ICP-MS (Agilent, model: 7500cs), and the etching rate (ER) of Co and Cu in the etching solution composition was calculated based on the surface area of ​​Co of the wafer and the concentration of Co and Cu in the etching solution composition. The results are shown in Table 8. Fig. 9 and Fig.10 .

[0128] [Table 8]

[0129]

[0130] The etching solution composition containing 1,2,4-triazole as a decomposition inhibitor not only suppresses the decomposition of H 2 O 2 contained in the etching solution composition for titanium nitride, but also exhibits an anti-corrosion effect on Cu and Co.

Claims

1. A method for inhibiting the decomposition of hydrogen peroxide contained in a titanium nitride etching solution composition using a decomposition inhibitor, comprising: adding a decomposition inhibitor to a titanium nitride etching solution composition containing hydrogen peroxide; The decomposition inhibitor comprises an azole compound as an active ingredient; Furthermore, the decomposition inhibitor is added to the titanium nitride etching solution composition in a ratio of 2 mmol / L to 10 mmol / L of the azole compound relative to 100 ppm of titanium nitride in the etching solution composition.

2. The method according to claim 1, wherein: The decomposition inhibitor also contains water.

3. The method according to claim 1, wherein: The decomposition inhibitor further comprises a water-soluble organic solvent.

4. The method according to claim 1, wherein: The azole compound includes at least one compound selected from the group consisting of 1,2,4-triazole, 1,2,3-triazole, imidazole and benzimidazole.

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