Etching solution composition with multi-film structure and application of etching solution composition

Abstract

The invention discloses a multi-film-layer structure etching liquid composition and application thereof. The multi-film-layer structure etching liquid composition is prepared from the following raw materials in percentage by weight: 10-23% of metal oxide, 0.1-6% of organic acid and salt thereof, 0.1-8% of inorganic strong acid and salt thereof, 0.01-2% of copper inhibitor, 0.001-0.5% of water-soluble silicon compound, 0.01-1% of etching inhibitor, 0.05-1.5% of fluoride, 0.1-5% of stabilizer and the balance of water. According to the invention, the fluoride is introduced, so that the corrosion to copper can be inhibited, and the damage to the lower-layer amorphous silicon film in the process of forming the wiring for connecting the source and the drain can be reduced. And the damage to the glass and amorphous silicon interface is reduced, so that the effect of minimizing poor etching is achieved.

Description

Technical Field

[0001] The invention relates to the field of corrosion inhibition of metal materials, and in particular to a multi-layer structure etching solution composition and application thereof. Background Art

[0002] In fields such as microelectronics, precision machinery, decorative crafts, and metal recycling, the precise etching of metal materials requires gradual optimization. In particular, as the precision of etching increases, etching solutions with more precise etching control are needed. Existing indium tin oxide etching solutions, when used in copper multi-layer structures, can damage the exposed copper metal film, leading to frequent wiring problems. Therefore, it is crucial to develop a composition that can effectively etch copper multi-layer structures and achieve excellent etching results for copper and multi-layer alloy films in the 4mask process.

[0003] Chinese invention patent CN112342547B discloses an etching solution composition that can selectively etch copper and molybdenum-containing films, and can provide metal wiring with good pattern linearity and taper angles by simply controlling the etching rate. However, when the thickness ratio of the copper film to the molybdenum-containing film is not large, it is easy to cause damage to the copper metal. Chinese invention patent application CN114540815A discloses a metal film etching solution composition containing hydrogen peroxide, a tertiary amine compound, and an N-heterocyclic condensed ring compound. It can uniformly achieve pattern linearity and low taper angles without damaging the underlying film. However, when the thickness difference between the copper film and the alloy metal film is small, it can still cause damage to the copper metal in a multi-layer structure. Summary of the Invention

[0004] In order to develop a composition that can effectively etch copper multi-layer structures and achieve excellent etching effects on copper and multi-layer alloy films in a 4-mask process, the first aspect of the present invention provides a multi-layer structure etching solution composition. The raw materials for preparation include, by weight percentage, 10-23% metal oxide, 0.1-6% organic acid and its salt, 0.1-8% inorganic strong acid and its salt, 0.01-2% copper inhibitor, 0.001-0.5% water-soluble silicon compound, 0.01-1% etching inhibitor, 0.05-1.5% fluoride, 0.1-5% stabilizer, and water is added to 100%.

[0005] As an embodiment, the weight percentage of the fluoride is 0.05-0.6%.

[0006] As an embodiment, the weight percentage of the fluoride includes one of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, and 0.6%.

[0007] As an embodiment, the weight percentage of the water-soluble silicon compound is 0.01-0.2%.

[0008] As an embodiment, the weight percentage of the water-soluble silicon compound includes one of 0.01%, 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.16%, 0.18%, and 0.2%.

[0009] As an embodiment, the raw materials prepared include, by weight percentage, 13-17% metal oxide, 0.5-4% organic acid and its salt, 2-4% inorganic strong acid and its salt, 0.1-6% copper inhibitor, 0.01-0.2% water-soluble silicon compound, 0.05-0.6% etching inhibitor, 0.05-0.6% fluoride, 0.05-2% stabilizer, and water is added to 100%.

[0010] As an embodiment, the weight percentage of the metal oxide is 13-17%.

[0011] As an embodiment, the weight percentage of the metal oxide includes one of 13%, 14%, 15%, 16%, and 17%.

[0012] As an embodiment, the weight percentage of the organic acid and its salt is 0.5-4%.

[0013] As an embodiment, the weight percentage of the organic acid and its salt is one of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, and 4%.

[0014] As an embodiment, the weight percentage of the inorganic strong acid and its salt is 2-4%.

[0015] As an embodiment, the weight percentage of the inorganic strong acid and its salt is one of 2%, 2.5%, 3%, 3.5% and 4%.

[0016] As an embodiment, the weight percentage of the copper inhibitor is 0.1-0.6%.

[0017] As an embodiment, the weight percentage of the copper inhibitor is one of 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, and 0.6%.

[0018] As an embodiment, the weight percentage of the etching inhibitor is 0.05-0.6%.

[0019] As an embodiment, the weight percentage of the etching inhibitor is one of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, and 0.6%.

[0020] As an embodiment, the weight percentage of the stabilizer is 0.5-2%.

[0021] As an embodiment, the weight percentage of the stabilizer is one of 0.5%, 1%, 1.5%, and 2%.

[0022] As an embodiment, the metal oxide is hydrogen peroxide.

[0023] As an embodiment, the organic acid contains at least one carboxyl group and does not contain a nitrogen atom.

[0024] As an embodiment, the organic acid includes but is not limited to at least one of acetic acid, formic acid, butyric acid, citric acid, glycolic acid, oxalic acid, malonic acid, malic acid, valeric acid, propionic acid, tartaric acid, gluconic acid, and succinic acid.

[0025] As an embodiment, the organic acid salt includes but is not limited to at least one of acetate, formate, butyrate, citrate, glycolate, oxalate, malonate, malate, valerate, propionate, tartrate, gluconate, and succinate.

[0026] As an embodiment, the inorganic strong acid includes but is not limited to at least one of sulfuric acid, nitric acid, and hydrochloric acid.

[0027] As an embodiment, the inorganic strong acid salt includes but is not limited to at least one of sulfate, nitrate, and hydrochloride.

[0028] As an embodiment, the fluoride is a water-soluble fluoride, including at least one of HF, NaF, KF, AlF3, HBF4, NH4F, NH4HF2, NaHF2, KHF2, NH4BF4 or NaHF2.

[0029] As an embodiment, the water-soluble silicon compound includes at least one of metasilicate or fluorinated silicate.

[0030] As an embodiment, the metasilicate includes but is not limited to one of sodium metasilicate and potassium metasilicate.

[0031] As an embodiment, the fluorinated silicate includes but is not limited to one of sodium hexafluorosilicate, potassium hexafluorosilicate, and hexafluorosilicic acid.

[0032] As an embodiment, the etching inhibitor includes at least one of alkylamine thiol, amino acid derivatives, hydroxylamine, and etheramine.

[0033] As an embodiment, the alkylamine thiol includes but is not limited to at least one of 3-amino-4-octanol, 2-(diethylamino)ethanethiol, methylcystamine, 2-(tert-butylamino)ethanethiol, 3-butoxypropylamine, 2-(isopropylamino)ethanol, 2-(methylthioethyl)amine, 1-aminopropane-2-thiol, and aminomethylpropanol.

[0034] As an embodiment, the amino acid derivative includes but is not limited to at least one of safflower yellow, N-acetylcystamine, homocystamine, dimercaptoethylamine, leucinol, and L-threonine.

[0035] As an embodiment, the hydroxylamine includes but is not limited to at least one of diethylaminoethanol, 2,2'-dimethoxy-1,1-dimethyldiethylamine, N,N-dimethylhydroxylamine, and N,O-dimethylhydroxylamine.

[0036] As an embodiment, the copper inhibitor includes at least one of a heterocyclic aromatic compound or a heterocyclic aliphatic compound.

[0037] As an embodiment, the heterocyclic aromatic compound includes but is not limited to at least one of furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, 5-aminotetrazole or methyltetrazole.

[0038] As an embodiment, the heterocyclic aliphatic compound includes but is not limited to at least one of piperazine, methylpiperazine, hydroxyethylpiperazine, pyrrolidine or alloxan.

[0039] As an embodiment, the stabilizer is a polyol, and the polyol includes at least one of polyethylene glycol, polybutylene glycol, polypropylene glycol, and polytetramethylene ether glycol.

[0040] As an embodiment, the weight average molecular weight of the polyethylene glycol is 200-1500 Da.

[0041] As an embodiment, the preparation method of the multi-layer structure etching solution composition is: adding the raw materials for preparing the multi-layer structure etching solution composition into water in sequence and mixing them evenly to obtain the etching solution.

[0042] During experiments, the inventors discovered that using a conventional single-agent etchant in etching multi-layer structures like Cu-ITO and Cu-MoNb can damage the exposed copper after etching the copper and then the ITO or MoNb, leading to poor wiring. The present invention introduces a fluorine-containing component to avoid damage to the exposed copper. The addition of a soluble silicon salt further suppresses damage to the glass substrate. This is likely due to the competitive reaction between the dissolved and dispersed silicon ions in the composition and the fluorine ions, which inhibits damage to the interface between the glass and amorphous silicon. This minimizes poor etching and enables integrated etching of Cu-ITO and Cu-MoNb multi-layer structures, resulting in excellent etching results.

[0043] A second aspect of the present invention provides an application of a multi-layer structure etching solution composition, which is applied to etching a multi-layer structure of Cu-ITO or Cu-MoNb.

[0044] As an embodiment, the thickness of the Cu film in the Cu-ITO and Cu-MoNb is The thickness of the ITO film in the Cu-ITO is The thickness of the MoNb film in the Cu-MoNb is

[0045] As an embodiment, the thickness of the Cu film in the Cu-ITO or Cu-MoNb is The thickness of the ITO film in the Cu-ITO is The thickness of the MoNb film in the Cu-MoNb is

[0046] As an embodiment, the etching temperature of the Cu-ITO is 30-35° C., and the etching time is 90-95 s.

[0047] As an embodiment, the etching temperature of the Cu-ITO is 33° C., and the etching time is 90 s.

[0048] As an embodiment, the etching temperature of the Cu-MoNb is 30-35° C., and the etching time is 95-100 s.

[0049] As an embodiment, the etching temperature of the Cu-MoNb is 32° C., and the etching time is 100 s.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] (1) The multi-layer structure etching solution composition of the present invention can inhibit the corrosion of copper by introducing fluoride, and reduce the damage to the underlying amorphous silicon film during the formation of the source-drain wiring.

[0052] (2) The multi-layer structure etching solution composition of the present invention reduces damage to the interface between glass and amorphous silicon through the combined action of fluoride and water-soluble silicon compound, thereby achieving the effect of minimizing etching defects.

[0053] (3) The multi-layer structure etching solution composition of the present invention reduces damage to the glass substrate by using a combination of metal oxides, acids and their salts, and etching inhibitors.

[0054] (4) The multi-layer structure etching solution composition of the present invention can effectively etch the multi-layer structure of Cu-ITO and Cu-MoNb, and can also achieve excellent etching effect on copper, indium tin oxide film, and molybdenum niobium alloy film in the 4mask process.

[0055] (5) The multi-layer structure etching solution composition of the present invention has low residue, no cracks, critical dimension loss (CD-loss) of 0.50-0.65 μm, taper angle of 40-50°, no side etching, and can achieve integrated etching of Cu-ITO and Cu-MoNb after etching the multi-layer structure of Cu-ITO and Cu-MoNb. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 These are SEM images of Cu-ITO and Cu-MoNb etched by the etching solution composition prepared in Example 1. In the figure, left: Cu-ITO; right: Cu-MoNb.

[0057] Figure 2 These are SEM images of Cu-ITO and Cu-MoNb etched by the etching solution composition prepared in Comparative Example 1. In the figure, left: Cu-ITO; right: Cu-MoNb.

[0058] Figure 3 These are SEM images of Cu-ITO and Cu-MoNb etched by the etching solution composition prepared in Comparative Example 2. In the figure, left: Cu-ITO; right: Cu-MoNb.

[0059] Figure 4 These are SEM images of Cu-ITO and Cu-MoNb etched by the etching solution composition prepared in Comparative Example 3. In the figure, left: Cu-ITO; right: Cu-MoNb. DETAILED DESCRIPTION

[0060] Example

[0061] A multi-layer structure etching solution composition, prepared by raw materials in weight percentage as shown in Table 1:

[0062] Table 1

[0063]

[0064]

[0065] Comparative Example

[0066] A multi-layer structure etching solution composition, prepared by raw materials in weight percentage as shown in Table 2:

[0067] Table 2

[0068]

[0069] The preparation method of the multi-layer structure etching liquid composition comprises the following steps: adding raw materials for preparing the multi-layer structure etching liquid composition into water in sequence and mixing the mixture evenly.

[0070] The invention discloses an application of a multi-layer structure etching solution composition. The etching solution compositions prepared in the embodiment and the comparative example are both used for etching Cu-ITO and Cu-MoNb.

[0071] The thickness of the Cu film in the Cu-ITO is The thickness of the ITO film is The etching temperature of the Cu-ITO is 33° C., and the etching time is 90 s.

[0072] The thickness of the Cu film in the Cu-MoNb is The thickness of the MoNb film is The etching temperature of the Cu-MoNb is 32° C., and the etching time is 100 s.

[0073] Performance Testing

[0074] 1. After etching Cu-ITO and Cu-MoNb using the etching solutions of the examples and comparative examples, the test results for Cu-ITO are shown in Table 3, and the test results for Cu-MoNb are shown in Table 4. Figure 1-4 .

[0075] Table 3

[0076]

[0077] Table 4

[0078]

[0079]

[0080] Conditions for excellent etching performance: CD-loss 0.50-0.65μm, Taper angle 40-50°, no residue, no cracks, and no side erosion.

[0081] The maximum copper loading (ppm) was measured starting from a copper concentration of 500 ppm and continued until a change of 10% or more in CD bias and taper angle was observed, or until residual concentration was observed.

[0082] The SEM images of Example 1 and Comparative Examples 1-3 after etching are shown in FIG. Figure 1-4 .

[0083] Depend on Figure 1 Excellent etching performance is evident. The Cu-ITO test piece (left) exhibits no residue and meets the target CD bias and tapering values. The Cu-MoNb test piece (right) exhibits no residue and no undercut, achieving the target CD bias and tapering values.

[0084] Depend on Figure 2 The etching characteristics are poor. The Cu-ITO test piece (left) shows no residue, but the CD bias and taper angle targets are not met. The Cu-MoNb test piece (right) shows no residue, but minor undercutting is observed. The CD bias and taper angle targets are also not met.

[0085] Depend on Figure 3 Poor etching characteristics are evident. The ITO layer of the Cu-ITO test piece (left) was not etched, and the CD bias and taper angle targets were not achieved. The Cu-MoNb test piece (right) showed no residue, but minor undercutting was observed. The CD bias and taper angle targets were also not achieved.

[0086] Depend on Figure 4 Poor etching characteristics are evident. The ITO layer of the Cu-ITO test piece (left) was not etched, and the target CD bias and taper angle values were not achieved. The Cu-MoNb test piece (right) showed no residue, but undercutting was observed. The target CD bias and taper angle values were also not achieved.

Claims

1. A multi-layer structure etching solution composition, characterized in that The raw materials include, by weight percentage, 10-23% of metal oxide, 0.1-6% of organic acid and its salt, 0.1-8% of inorganic strong acid and its salt, 0.01-2% of copper inhibitor, 0.001-0.5% of water-soluble silicon compound, 0.01-1% of etching inhibitor, 0.05-1.5% of fluoride, 0.1-5% of stabilizer, and water is added to 100%.

2. The multi-layer structure etching solution composition according to claim 1, wherein The weight percentage of the fluoride is 0.05-0.6%.

3. The multi-layer structure etching solution composition according to claim 1, wherein The weight percentage of the water-soluble silicon compound is 0.01-0.2%.

4. The multi-layer structure etching solution composition according to claim 2, wherein The fluoride is a water-soluble fluoride, including at least one of HF, NaF, KF, AlF3, HBF4, NH4F, NH4HF2, NaHF2, KHF2, NH4BF4 or NaHF2.

5. The multi-layer structure etching solution composition according to claim 3, wherein The water-soluble silicon compound includes at least one of metasilicate or fluorinated silicate.

6. The multi-layer structure etching solution composition according to claim 1, wherein The etching inhibitor includes at least one of alkylamine thiol, amino acid derivatives, hydroxylamine, and etheramine.

7. The multi-layer structure etching solution composition according to claim 1, wherein The copper inhibitor includes at least one of a heterocyclic aromatic compound or a heterocyclic aliphatic compound.

8. The multi-layer structure etching solution composition according to claim 1, wherein The stabilizer is a polyol, and the polyol includes at least one of polyethylene glycol, polybutylene glycol, polypropylene glycol, and polytetramethylene ether glycol.

9. An application of the multi-layer structure etching solution composition according to any one of claims 1 to 8, characterized in that: Applicable to etching multi-layer structures of Cu-ITO or Cu-MoNb.

10. The use of the multi-layer structure etching solution composition according to claim 9, characterized in that: The Cu film thickness in Cu-ITO and Cu-MoNb is The thickness of the ITO film in the Cu-ITO is The thickness of the MoNb film in the Cu-MoNb is

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