JP2016025321A - Etchant composition and etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etchant composition which makes possible to collectively etch, of a metal multilayer film including a Ti-containing layer made of Ti or an alloy including Ti as a primary component, an Al-containing layer made of Al or an alloy including Al as a primary component, and an In-containing metal oxide layer, the Ti-containing layer and the Al-containing layer, and to reduce the damage to the In-containing metal oxide layer in etching; and an etching method using the etchant composition.SOLUTION: An etchant composition of the present invention is an etchant composition for collectively etching, of a metal multilayer film including a Ti-containing layer made of Ti or an alloy including Ti as a primary component, an Al-containing layer made of Al or an alloy including Al as a primary component, and an In-containing metal oxide layer, the Ti-containing layer and the Al-containing layer. The etchant composition comprises one or more selected from a group consisting of a fluorine compound, an oxo acid of phosphorus, a metal salt, an organic solvent, an ammonium salt, and a quaternary ammonium compound. The etchant composition is acid.SELECTED DRAWING: None

Description

  The present invention relates to an etching solution composition, and more particularly to an etching solution composition used for etching a metal laminated film used for gate, source and drain electrodes of a flat panel display.

  Conventionally, in the field of flat panel displays (FPD), amorphous silicon (a-Si) has been used as a channel material for thin film transistors (TFTs) for liquid crystal panels (LCDs) for large televisions, small high definition LCDs and organic ELs. Low-temperature polysilicon (LT p-Si) has been used for displays (OLED) and the like. However, in recent years, as electronic devices have been reduced in size, weight, and power consumption, introduction of oxide semiconductors as channel materials in place of these amorphous silicon and low-temperature polysilicon has been studied.

As an oxide semiconductor, for example, IGZO composed of indium (In), gallium (Ga), and zinc (Zn) has been put into practical use. IGZO exhibits high electron mobility (−10 cm ² / (V · S)), excellent driving stability, and uniformity even in an amorphous state formed at a low temperature. In addition, since a film composed of IGZO can be formed at 200 ° C. or lower, it can be formed on a plastic substrate, and a flexible display can be realized by using the film as a channel material of an OLED TFT. Is shown in Non-Patent Document 1.

  In addition to IGZO, metal oxide semiconductors containing In, such as IZO and ITO, are expected to be applied to solar cell materials, light-emitting diode materials, wide band gap materials, and resistance change memory materials according to their characteristics. It is a material that has received much attention.

  Also, Al is often used as an electrode wiring for the gate, source and drain electrodes in the FPD. When using Al as an electrode wiring, titanium (Ti) or molybdenum (Mo) is mainly used as a barrier metal for the purpose of preventing oxidation or diffusion of Al. A film is formed and arranged on both lower portions. As the barrier metal, Ti is preferable from the viewpoint of cost merit.

  As etching methods for patterning the gate, source, and drain electrodes, two types of methods are known: wet etching and dry etching. The dry etching process is effective for processing a high-definition pattern, but there are problems such as high cost due to the introduction of the apparatus and a decrease in yield due to generation of dust after the etching process. On the other hand, for wet etching, it is difficult to process a high-definition pattern, but it does not require an expensive device as much as dry etching, so there is a cost merit and an improvement in yield can be expected.

  A chemical used for wet etching of a metal laminated film having a layer made of Ti or a Ti-based alloy and a layer made of Al or an Al-based alloy, and an etching method using the chemical are patented It is shown in documents 1-3.

JP 2007-67367 A JP 2008-53374 A JP 2010-199121 A

Kentaro Miura, Tomomasa Ueda, Hajime Yamaguchi, "Oxide Semiconductor TFT Realizing Light and Thin Sheet Display", Toshiba Review, 2012, Vol. 67, No. 1, pp. 34-37

  By the way, as described above, IGZO is often used instead of a-Si as a channel material of a thin film transistor (TFT), and in this case, the thin film transistor has a structure in which IGZO is present on the base of the source and drain electrodes. Have The etching solutions disclosed in Patent Documents 1 to 3 do not erode the underlying layer of the stacked film to be etched when the underlying layer is a-Si. However, while IGZO has a property of being easily dissolved in an acidic region, Patent Documents 1 to 3 do not examine the case where IGZO is present as a base.

  In the case where IGZO is present on the base of the source and drain electrodes, that is, when the thin film transistor has a laminated film structure such as Ti / Al / Ti / IGZO, Al / Ti / IGZO, the thin film transistor is formed on the Ti / Al film on the IGZO. When processing the Al / Ti layer and the Al / Ti layer using wet etching, the IGZO is easily damaged by the etching solution. Therefore, when the Ti / Al / Ti layer and the Al / Ti layer on the IGZO are processed by wet etching, a cap film is required on the IGZO, and the process and cost increase. Although thin film transistors can also be manufactured by dry etching processing, as described above, there are problems such as high cost due to the introduction of the apparatus and a decrease in yield due to dust generation after the etching processing.

  In order to solve these problems, there is a need for a chemical solution and method capable of collectively etching only the upper metal laminated film without damaging the underlying metal oxide film containing In.

  Accordingly, an object of the present invention includes a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. Etching solution composition capable of collectively etching Ti-containing layer and Al-containing layer of metal laminated film and capable of reducing damage of metal oxide layer containing In during etching, and the etching An object of the present invention is to provide an etching method using a liquid composition.

  In order to solve the above-mentioned problems, the inventors of the present invention have made an oxidative solution of phosphorus oxoacid in an acidic aqueous solution containing a fluorine compound that can suitably collectively etch a metal laminated film composed of a Ti-based metal and an Al-based metal. By adding one or more selected from the group consisting of metal salts, organic solvents, ammonium salts and quaternary ammonium compounds, damage to the metal oxide layer containing In can be suppressed, and When it contains oxo acid, it is found that the above-mentioned damage suppression effect becomes remarkable by combining with other components, and the etching performance for Ti-based metal layer and Al-based metal layer is not impaired, and the present invention is completed. It came to do.

That is, the present invention relates to the following.
(1) Ti of a metal laminated film including a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. An etching solution composition for collectively etching the containing layer and the Al-containing layer,
A fluorine compound;
Including one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds,
The etching solution composition which is acidic.
(2) The fluorine compound includes one or more selected from the group consisting of hydrofluoric acid, ammonium fluoride, sodium fluoride, hexafluorosilicic acid and tetrafluoroboric acid. Etching solution composition.
(3) The metal salt includes one or more selected from the group consisting of iron salts, zirconium salts, tin salts, alkali metal salts, and alkaline earth metal salts, as described in (1) or (2) Etching solution composition.
(4) The etching solution composition according to (3), wherein the alkali metal salt is sodium acetate and / or potassium acetate.
(5) The etching solution composition according to any one of (1) to (4), which contains an alcohol compound and / or a carboxylic acid compound as the organic solvent.

(6) The etching solution composition according to any one of (1) to (5), wherein the ammonium salt includes one or more selected from the group consisting of ammonium nitrate, ammonium phosphate, ammonium sulfate, and ammonium acetate. .
(7) The etching solution composition according to any one of (1) to (6), wherein the metal oxide layer contains at least one element selected from the group consisting of Zn, Al, Ga, and Sn.
(8) The etching solution composition according to any one of (1) to (7), wherein the pH is 4.0 or less.
(9) Furthermore, any one or two or more acids selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid and perchloric acid are included. Etching solution composition.
(10) Ti of a metal laminated film including a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. A step of etching the containing layer and the Al-containing layer at once using an etching solution composition;
Here, the etching solution composition comprises a fluorine compound and one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds, A method for etching a metal laminate film, which is acidic.

  According to the present invention, a metal laminate including a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. Etching solution composition capable of collectively etching Ti-containing layer and Al-containing layer of film, and capable of reducing damage of metal oxide layer containing In during etching, and the etching solution composition An etching method using an object can be provided.

  Since the conventional etching liquid for metal laminated films exhibits acidity, there has been a problem that the metal oxide layer containing In caused by the etching liquid is significantly damaged. However, by adding a specific additive, it is possible to suppress the damage, and as a result, the influence of the etching process on the semiconductor properties of the metal oxide as the thin film semiconductor layer can be minimized. The characteristics desired for the metal oxide can be sufficiently exhibited in the display of the panel display. In addition, since the etching solution composition of the present invention to which the additive is added has the same etching performance as that of the conventional etching solution, the Ti-containing layer and the Al-containing layer can be sufficiently etched together. For this reason, by using the etching solution composition of the present invention, it is possible to avoid complication and lengthening of the manufacturing process such as a combination with dry etching and a plurality of etching processes, and contribute to cost reduction of the manufacturing process.

Hereinafter, the present invention will be described in detail based on preferred embodiments.
An etching solution composition of the present invention comprises a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. An etching solution composition for collectively etching a Ti-containing layer and an Al-containing layer of a metal laminate film comprising:
A fluorine compound;
Including one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds,
The etching solution composition is acidic.
Hereinafter, each component of the etching solution composition will be described in detail.

  Examples of the fluorine compound contained in the etching solution composition include hydrofluoric acid, hexafluorosilicic acid and tetrafluoroboric acid, or a metal salt or an ammonium salt thereof, and one or more of them. Can be used. When the fluorine compound is a metal salt, the metal salt can be, for example, an alkali metal salt such as lithium, sodium, or potassium, or an alkaline earth metal salt such as magnesium or calcium. More specifically, as the fluorine compound, hydrofluoric acid, ammonium fluoride, potassium fluoride, calcium fluoride, ammonium hydrogen fluoride, potassium hydrogen fluoride, sodium fluoride, magnesium fluoride, lithium fluoride, Examples include hexafluorosilicate, ammonium hexafluorosilicate, sodium hexafluorosilicate, potassium hexafluorosilicate, tetrafluoroborate, ammonium tetrafluoroborate, sodium tetrafluoroborate, and potassium tetrafluoroborate.

Among the above-mentioned, the etching liquid composition contains one or more selected from the group consisting of hydrofluoric acid, ammonium fluoride, sodium fluoride, hexafluorosilicic acid, and tetrafluoroboric acid as the fluorine compound. It is preferable to include.
Furthermore, it is preferable that hydrofluoric acid and / or ammonium fluoride is contained as the fluorine compound contained in the etching solution composition. In particular, ammonium fluoride more reliably damages the metal oxide layer containing In during etching. Therefore, it is preferable.

  Although the density | concentration of the fluorine compound in an etching liquid composition is not specifically limited, For example, 0.01-5.0 mass%, Preferably it is 0.05-1.0 mass%, More preferably, it is 0.05-0. It can be 35 mass%. When the concentration of the fluorine compound in the etching solution composition is 5.0% by mass or less, it is possible to more reliably suppress damage to the material of the substrate carrying the metal laminated film, for example, glass. On the other hand, when the concentration of the fluorine compound in the etching solution composition is 0.05% by mass or more, the etching rate of the Ti-containing layer is sufficient, and there is no problem of increasing the etching time of the metal laminated film.

  The etching solution composition contains one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts, and quaternary ammonium compounds. Thereby, the etching rate with respect to the metal oxide layer containing In by an etching liquid composition can be reduced, and damage to the metal oxide layer containing In during etching can be suitably prevented.

The phosphorus oxo acid that can be contained in the etching solution composition is not particularly limited, and examples thereof include phosphoric acid, phosphorous acid, hypophosphorous acid, phosphinic acid, phosphonic acid, peroxomonophosphoric acid, pyrophosphoric acid, and the like. It is done. Among these, phosphoric acid is preferable as the oxo acid of phosphorus because the etching performance of the metal laminated film can be improved.
Although the density | concentration of the oxo acid of phosphorus in an etching liquid composition is not specifically limited, It is preferable that it is 0.001-1.0 mass%, and it is more preferable that it is 0.005-0.4 mass%. When the concentration of the oxoacid of phosphorus is within the above range, the damage prevention effect of the metal oxide layer containing In can be sufficiently obtained, and the etching uniformity of the Ti-containing layer is not greatly impaired.

Although it does not specifically limit as a metal salt which can be contained in an etching liquid composition, What melt | dissolves in an etching liquid composition and discharge | releases a metal ion can be used suitably. Metal ions that may be contained in the metal salt is not particularly limited, for ^{example, Li +, Na +, K} +, Rb +, Cs +, Fr + , etc. of the alkali metal ^{ions, Be 2+, Mg 2+, Ca} 2+, Alkaline earth metal ions such as Sr ²⁺ , Ba ²⁺ , Ra ²⁺ , metal ions including transition metals such as Fe ²⁺ , Fe ³⁺ , Zr ⁴⁺ , ZrO ²⁺ , metals including group 12-14 metal elements such as Sn ²⁺ And ions.
Further, the counter ion of the metal ion in the metal salt is not particularly limited, but for example, organic acid ions such as acetate ion, oxalate ion, formate ion, citrate ion, lactate ion, carbonate ion, nitrate ion, sulfate Ion, hydrochloric acid ion, perchlorate ion, chlorate ion, chlorite ion, hypochlorite ion, hydrofluoric acid ion, bromate ion, hydrobromide ion, hydroiodide ion, iodate ion, peroxygen ion Iodate ion, orthoperiodate ion, sulfite ion, thiosulfate ion, methanesulfonate ion, phosphate ion, phosphite ion, hypophosphite ion, phosphinate ion, phosphonate ion, peroxomonophosphate ion Inorganic anions such as pyrophosphate ion, silicate ion, orthosilicate ion, metasilicate ion, borate ion, etc. It is.

Moreover, it is preferable that an etching liquid composition contains the 1 type (s) or 2 or more types selected from the group which consists of an iron salt, a zirconium salt, a tin salt, an alkali metal salt, and an alkaline-earth metal salt as a metal salt. In particular, an iron salt is preferable because it can improve the etching uniformity and etching rate of the Ti-containing layer and is effective in improving the etching characteristics of the metal laminated film.
Specifically, examples of the iron salt include iron nitrate such as iron acetate, iron chloride, iron phosphate, and iron sulfate. Examples of the zirconium salt include zirconium nitrate oxide, zirconium chloride oxide, and zirconium oxide oxide. Examples of the tin salt include tin acetate, tin chloride, and tin sulfate. Examples of the alkali metal salt include sodium acetate, sodium nitrate, sodium sulfate, sodium chloride, trisodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, sodium perchlorate, potassium acetate, potassium nitrate, potassium sulfate, Examples include potassium chloride, potassium phosphate, and potassium perchlorate. Examples of the alkaline earth metal salt include calcium acetate, magnesium acetate, calcium nitrate, magnesium nitrate, calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, calcium phosphate, and magnesium phosphate.

Among the above, the etching solution composition preferably contains iron nitrate, iron acetate and / or iron chloride as the iron salt. Thereby, damage to the metal oxide layer containing In can be suppressed, and the etching characteristics of the metal laminated film made of Ti-based metal and Al-based metal can be improved.
Among the above-mentioned, it is preferable that especially an etching liquid composition contains a zirconium nitrate oxide as a zirconium salt. Thereby, damage to the metal oxide layer containing In can be suppressed.
Among the above-mentioned, it is preferable that an etching liquid composition contains tin acetate especially as a tin salt. Thereby, damage to the metal oxide layer containing In can be suppressed.

Moreover, it is preferable that an etching liquid composition contains especially sodium acetate and / or potassium acetate as an alkali metal salt. Thereby, damage to the metal oxide layer containing In can be suppressed.
Moreover, it is preferable that an etching liquid composition contains especially calcium acetate and / or magnesium acetate as alkaline-earth metal salt. Thereby, damage to the metal oxide layer containing In can be suppressed.

  Although the density | concentration of the metal salt in an etching liquid composition is not specifically limited, For example, 0.005-5.0 mass%, Preferably it is 0.02-1.0 mass%, More preferably, it is 0.02-0.5. More preferably, it is mass%. Within the above range, it is possible to prevent the metal oxide layer containing In from being damaged while preventing precipitation of the metal salt in the etching solution composition.

  In particular, when an alkali metal salt or an alkaline earth metal salt is used as the metal salt, the concentration of the metal salt in the etching solution composition is, for example, 0.01 to 5.0% by mass, preferably 0.05 to 1.%. It is more preferable that it is 0 mass%, More preferably, it is 0.1-0.5 mass%. Within the above range, it is possible to prevent damage to the metal oxide layer containing In, while making the etching time between the metal stacks relatively short.

  The organic solvent that can be included in the etching solution composition is not particularly limited as long as it is compatible with water, and any organic solvent may be used alone or in combination of two or more. Examples of the organic solvent include alcohol compounds, carboxylic acid compounds, ketone compounds, ether compounds, organic sulfur compounds, nitrogen-containing five-membered ring compounds, amide compounds, amine compounds, and imide compounds.

  Although it does not specifically limit as an alcohol compound, For example, C1-C10, Preferably the alcohol which is 1-6 is mentioned. These may be saturated or unsaturated, linear, branched or cyclic structures, and may be monohydric or polyhydric alcohols. Preferred examples of the alcohol compound include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, n-amyl alcohol, sec-amyl alcohol, 3-pentanol, 2 -Linear or branched monohydric alcohol having 1 to 10, preferably 2 to 6 carbon atoms, such as methyl-1-butanol, isoamyl alcohol, tert-amyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, hexanol and the like Cyclic alcohols such as 1-cyclopentanol and 1-cyclohexanol; ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol Straight chain or branched alkylene glycol having 2 to 6 carbon atoms such as 1,6-hexanediol; oligomer of the alkylene glycol such as diethylene glycol and dipropylene glycol (for example, degree of polymerization 2 to 10, preferably 2 to 4); 1 , 2,4-butanetriol, 1,2,3-propanetriol (glycerin), 1,2,3-hexanetriol and other triol compounds.

  The carboxylic acid compound is not particularly limited as long as it is liquid and compatible with water, and examples thereof include aliphatic carboxylic acids having 1 to 5 carbon atoms. Specific examples of the carboxylic acid compound include formic acid, acetic acid, propionic acid, butyric acid, and valeric acid.

  Although it does not specifically limit as a ketone compound, For example, a C3-C10 ketone compound is mentioned, As a preferable specific example of a ketone compound, chain | strands, such as acetone, methyl ethyl ketone, 4-hydroxy-2-methylpentanone, are mentioned. And cyclic ketone compounds such as cyclohexanone, cyclic ester compounds such as γ-butyrolactone, and carbonate ester compounds such as ethylene carbonate and propylene carbonate.

  Although it does not specifically limit as an ether compound, For example, a water-soluble ether compound is mentioned, For example, tetrahydrofuran, a dioxane, ethylene glycol dimethyl ether etc. are mentioned as a preferable specific example of an ether compound.

  The organic sulfur compound is not particularly limited, and examples thereof include dialkyl sulfoxides such as dimethyl sulfoxide, mercapto group-containing compounds such as mercaptosuccinic acid, and 2,2'-thiodiacetic acid.

  The nitrogen-containing five-membered ring compound is not particularly limited, and examples thereof include pyrrolidinone, imidazolidinone, oxazole, thiazole, oxadiazole, thiadiazole, tetrazole, triazole, and derivatives thereof. Preferable specific examples of the nitrogen-containing five-membered ring compound include pyrrolidinone compounds such as N-methyl-2-pyrrolidinone (NMP), 2-pyrrolidinone, polyvinylpyrrolidinone, 1-ethyl-2-pyrrolidinone, 1,3-dimethyl- 2-imidazolidinone, 2-imidazolidinone, 2-imino-1-methyl-4-imidazolidinone, 1-methyl-2-imidazolidinone, 2,5-bis (1-phenyl) -1,1 , 3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -4,3,4-oxadiazole, 2,5 -Bis (1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxa) Diazolyl -4-tert-butylbenzene], 2,5-bis (1-naphthyl) -1,3,4-thiadiazole, 2,5-bis (1-naphthyl) -1,3,4-thiadiazole, 1,4 -Bis [2- (5-phenylthiadiazolyl)] benzene, 2,5-bis (1-naphthyl) -4,3,4-triazole, 1,4-bis [2- (5-phenyltriazolyl) )] Benzene and the like.

  The amide compound is not particularly limited as long as it has an amide group. The amide compound may further have a substituent such as a nitro group, a phenyl group, or a halogen. Preferable specific examples of the amide compound include N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, acrylamide, adipamide, Acetamide, 2-acetamidoacrylic acid, 4-acetamidobenzoic acid, methyl 2-acetamidobenzoate, ethyl acetamidoacetate, 4-acetamidophenol, 2-acetamidofluorene, 6-acetamidohexanoic acid, p-acetamidobenzaldehyde, 3-acetamido Diethyl malonate, 4-acetamidobutyric acid, amidosulfuric acid, ammonium amidosulfate, amidol, 3-aminobenzamide, p-aminobenzenesulfonamide, anthranilamido, isonico Namide, N-isopropylacrylamide, N-isopropyl-1-piperazineacetamide, ureaamide lyase, 2-ethoxybenzamide, erucylamide, oleic acid amide, 2-chloroacetamide, glycinamide hydrochloride, succinic acid amide, succinic acid diamide, salicyl Amide, 2-cyanoacetamide, 2-cyanothioacetamide, diacetamide, diacetone acrylamide, diisopropylformamide, N, N-diisopropylisobutyramide, N, N-diethylacetoacetamide, N, N-diethylacetamide, N, N- Diethyldodecanoic acid amide, N, N-diethylnicotinamide, dicyanodiamide, N, N-dibutylformamide, N, N-dibromoacetamide, N, N-dimethylpropionami , N, N-dimethylbenzamide, stearic acid amide, sulfanilamide, sulfabenzamide, sulfamic acid, dansylamide, thioacetamide, thioisonicotinamide, thiobenzamide, 3-nitrobenzamide, 2-nitrobenzamide, 2-nitrobenzenesulfone Amide, 3-nitrobenzenesulfonamide, 4-nitrobenzenesulfonamide, pyrrolinamide, pyrazineamide, 2-phenylbutyramide, N-phenylbenzamide, phenoxyacetamide, phthalamide, phthaldiamide, fumaramide, N-butylacetamide, n-butyramide, Propanamide, propionamide, hexanoic acid amide, benzamide, benzenesulfonamide, formamide, malonamide, malondiamide, Examples thereof include tansulfonamide, N-methylbenzamide, N-methylmaleamic acid, iodoacetamide and the like.

  Preferable specific examples of the amine compound are not particularly limited. For example, urea, glycine, iminoacetic acid, N-acetylethanolamine, N-acetyldiphenylamine, allylamine, allylamine hydrochloride, allylcyclohexylamine, isoallylamine, isobutylamine, isopropanol Amine, isopropylamine, ethanolamine, ethanolamine hydrochloride, ethylamine hydrochloride, N-ethylethanolamine, N-ethylethylenediamine, N-ethyldiisopropylamine, N-ethyldiethanolamine, N-ethyldicyclohexylamine, N-ethyl-n -Butylamine, 2-ethylhexylamine, N-ethylbenzylamine, N-ethylmethylamine, ethylenediamine sulfate, ethylenediaminetetraacetic acid, Range amine tetraacetic acid tripotassium trihydrate, ethylenediaminetetraacetic acid trisodium dihydrate, ethylenediamine, ethoxyamine hydrochloride, diallylamine, diisobutylamine, diisopropanolamine, diisopropylamine, diethanolamine, diethanolamine hydrochloride, diethylamine, diethylamine hydrochloride Salt, diethylenetriamine, dicyclohexylamine, diphenylamine, diphenylamine hydrochloride, dimethylamine hydrochloride, N, N-dimethylallylamine, succiamic acid, stearylamine, stearylamine hydrochloride, sulfamic acid, thiamine hydrochloride, thiamine sulfate, triisopropanolamine , Triisopentylamine, triethylenediamine, triphanylamine, tribenzylamine, trimethylenedi Min, monoethanolamine, monoethanolamine hydrochloride and the like.

  Preferable specific examples of the imide compound are not particularly limited. For example, succinimide, hydroxysuccinimide, N-iodosuccinimide, N-acryloxysuccinimide, N-acetylphthalimide, 3-aminophthalimide, 4-aminophthalimide, N- Aminophthalimide, imidourea, N-ethylphthalimide, N-ethylmaleimide, N-carbethoxyphthalimide, carbodiimide, N-chlorosuccinimide, cycloxyimide, 2,6-dichloroquinone chloroimide, 3,3-dimethylglutarimide 1,8-naphthalimide, 3-nitrophthalimide, 4-nitrophthalimide, N-hydroxyphthalimide, potassium phthalimide, maleic acid imide, N-methylsuccinimide, iodosuccinimide, etc. Chain or cyclic imide compounds, and the like.

The etching solution composition preferably includes an alcohol compound and / or a carboxylic acid compound among the above-described components.
In particular, the etchant composition preferably contains a linear or branched alkylene glycol having 2 to 6 carbon atoms, an oligomer of the alkylene glycol and / or a triol compound as the alcohol compound, and has 2 to 6 carbon atoms. More preferably, it contains a linear or branched alkylene glycol, and more preferably contains ethylene glycol. Such a compound hardly dissolves the resist and is excellent in stability when nitric acid or the like acting as an oxidizing agent coexists.
Moreover, it is preferable that an etching liquid composition contains an acetic acid especially as a carboxylic acid compound.

  The concentration of the organic solvent in the etching solution composition is preferably 5 to 60% by mass, and more preferably 15 to 50% by mass. When the concentration of the organic solvent is not more than the above upper limit, problems such as resist damage, an increase in processing time of the metal laminated film, and a reaction with an acid acting as an oxidizing agent such as nitric acid can be avoided. Moreover, if the density | concentration of an organic solvent is more than the said lower limit, the damage prevention effect of the metal oxide layer containing In can fully be acquired.

  The ammonium salt that can be contained in the etching solution composition is not particularly limited, and examples thereof include ammonium nitrate, ammonium phosphate, ammonium sulfate, and ammonium acetate, and one or more selected from these can be used. In particular, ammonium nitrate is preferable because it hardly affects the etching rate even when added in a large amount, and as a result, the etching time of the metal laminated film does not change.

  Although the density | concentration of the ammonium salt in an etching liquid composition is not specifically limited, It is preferable that it is 5-40 mass%. Within the above range, the etching rate is affected to increase the etching time of the metal laminated film, and the damage of the metal oxide layer containing In can be prevented while preventing the generation of solids. it can.

The quaternary ammonium compound that can be included in the etching solution composition is not particularly limited. For example, tetraalkylammonium hydroxide, tetraalkylammonium fluoride, tetraalkylammonium chloride, tetraalkylammonium bromide, and tetraiodide iodide. Examples thereof include tetraalkylammonium halides such as alkylammonium. The carbon number of the alkyl group of the tetraalkylammonium hydroxide and the tetraalkylammonium halide can be, for example, 1 to 5, preferably 1 to 3. In particular, as the quaternary ammonium, tetraalkylammonium hydroxide is preferable, and tetramethylammonium hydroxide is more preferable.
Although the density | concentration of the quaternary ammonium compound in an etching liquid composition is not specifically limited, It is preferable that it is 1.0-40.0 mass%, and it is more preferable that it is 10.0-15.0 mass%. . Within the above range, the amount of acid added for pH adjustment can be relatively reduced, and damage to the metal oxide layer containing In can be prevented.

  Further, as described above, the etching solution composition contains one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds. When two or more additives are included, two or more components may be included from the same type of compound, or different types of components may be included.

  In particular, when different types of components are included, the etchant composition comprises phosphorus oxo acid and one or more selected from the group consisting of metal salts, organic solvents, ammonium salts, and quaternary ammonium compounds. Are preferably included in combination.

  The etching solution composition may contain an acid other than phosphorus oxoacid. Thereby, it is possible to adjust the pH of the etching solution composition. The acid is not particularly limited, but nitric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid, perchloric acid, chloric acid, chlorous acid, hypochlorous acid, hydrobromic acid, bromic acid, hydroiodic acid. Iodic acid, periodic acid, orthoperiodic acid, sulfurous acid, thiosulfuric acid, peroxodisulfuric acid, silicic acid, orthosilicic acid, metasilicic acid, carbonic acid, boric acid and the like. Among the above-mentioned, it is preferable that an etching liquid composition contains any 1 type, or 2 or more types of acids selected from the group which consists of nitric acid, hydrochloric acid, a sulfuric acid, methanesulfonic acid, and perchloric acid. Nitric acid is particularly preferable because it also acts as an oxidizing agent and can contribute to uniformly etching the Ti-containing layer.

  Although the density | concentration of acids other than the oxo acid of phosphorus in an etching liquid composition is not specifically limited, It is preferable that it is 0.1-10 mass%, and it is preferable that it is 0.1-3.0 mass%. If the acid concentration exceeds the upper limit, depending on the composition of the etching solution composition, not only the damage of the metal oxide containing In may increase, but also the etching characteristics for the metal laminated film may deteriorate. On the other hand, when the acid concentration is less than the lower limit, the etching rate for the Ti-containing layer and the Al-containing layer may decrease, and the processing time for etching the metal laminated film may increase.

  In addition, the etching liquid composition contains water in addition to the components described above. Although content of the water in an etching liquid composition can be made into the remainder of each component mentioned above, it is 40.00-99.9 mass%, for example.

  Moreover, although an etching liquid composition should just be acidic, it is preferable that pH is 4 or less, and it is more preferable that it is 1-4. Thereby, a dissolution rate of Ti above a certain level can be obtained, and etching of the metal laminated film becomes possible. The pH is measured at room temperature, for example, 25 ° C.

  Moreover, the etching liquid composition as described above can be prepared by mixing the above-described constituent components.

  The etching solution composition as described above includes a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. It is possible to collectively etch the Ti-containing layer and the Al-containing layer of the metal laminated film containing In, and it is possible to reduce damage to the metal oxide layer containing In during etching.

Next, a preferred embodiment of the etching method of the present invention will be described.
The etching method of the present invention includes a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. A step of collectively etching the Ti-containing layer and the Al-containing layer of the laminated film using an etching solution composition;
Here, the etching solution composition comprises a fluorine compound and one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds, This is an etching method for a metal laminate film that is acidic.

  As the etching solution composition used in this method, the etching solution composition of the present invention as described above can be used.

Further, the metal laminated film to be etched in this method includes a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal containing In. And an oxide layer.
Moreover, such a metal laminated film is normally carried on a substrate made of glass, silicon, a resin film or the like.

Here, “having Ti as the main component” means that the Ti content is 50% by mass or more, preferably 90% by mass or more, and “having Al as the main component” The content is 50% by mass or more, preferably 90% by mass or more. Each Ti-containing layer and / or Al-containing layer may contain a metal other than the main component. Here, the metal other than the main component is not particularly limited, and examples thereof include Zr, Ni, W, Nb, Zn, Mg, Cu, Mn, and Si.
In addition, the metal oxide layer containing In is not particularly limited, but includes, for example, at least one element selected from the group consisting of Zn, Al, Ga, and Sn, and two or more elements. Specific examples of such a metal oxide layer containing In include IZO (In—Zn—O), ITO (In—Sn—O), and IGZO (In—Ga—Zn—O).

As the layer structure of the metal laminated film, the Ti-containing layer or Al-containing layer to be etched is exposed to the outside as a surface layer, while the metal oxide layer containing In is disposed on the substrate side, for example. Preferably it is not exposed.
As a specific layer structure of the metal laminated film, from the surface layer to the substrate supporting the metal laminated film, an Al-containing layer / Ti-containing layer / In-containing metal oxide layer, Ti-containing layer / Al-containing layer / In It can be arranged in the order of a metal oxide layer containing, a Ti-containing layer / Al-containing layer / Ti-containing layer / In-containing metal oxide layer, and the like.

Moreover, the thickness of the Ti-containing layer in the metal laminated film is not particularly limited, but is, for example, 10 to 500 nm, and preferably 30 to 100 nm.
Moreover, the thickness of the Al-containing layer in the metal laminated film is not particularly limited, but is, for example, 50 to 10,000 nm, and preferably 200 to 500 nm.
Moreover, the thickness of the metal oxide layer containing In in the metal laminated film is not particularly limited, but is, for example, 1 to 500 nm, and preferably 30 to 100 nm.

Moreover, the etching conditions in this method are not specifically limited, For example, it can carry out according to the conditions of a well-known etching method.
Examples of the contact method between the metal laminated film and the etching solution composition include a dipping method in which the container is filled with the etching solution composition and the metal laminated film is immersed.
Alternatively, a spray method in which the etching solution composition is attached to the etching target by spraying, a spin method in which the etching solution composition is discharged from a nozzle onto the rotating etching target, or the like may be used. These and the dip method may be used in combination.
The etching time is not particularly limited, and can be, for example, 30 seconds to 240 seconds, preferably 60 to 150 seconds.
Further, the etching temperature (the temperature of the etching solution composition in the dip method, the temperature of the etching solution composition or the temperature of the metal laminated film in the spray method and the spin method) is not particularly limited, and is, for example, 20 to 50 ° C. , Preferably, it can be 30-40 degreeC. At this time, if necessary, the temperature of the etching solution composition, metal laminated film, etc. may be adjusted by a heating means such as a heater or a cooling means.

  As described above, the present invention includes a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In. The Ti-containing layer and the Al-containing layer of the metal laminated film can be collectively etched, and damage to the metal oxide layer containing In during etching can be reduced. For this reason, when a semiconductor is formed according to the present invention, the desired characteristics of the metal oxide layer containing In in the formed semiconductor can be sufficiently exhibited.

Therefore, the etching solution composition and the etching method according to the present invention are suitable for use in a semiconductor manufacturing process. In particular, the present invention is suitable for forming the gate, source and drain electrodes of a thin film transistor.
The thin film transistor thus formed can be suitably used as a display element of a display device, for example, a flat panel display.

  Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to this. In the present invention, each component can be replaced with any component that can exhibit the same function, or any component can be added.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in detail, this invention is not limited by these Examples.
[Examples 1 to 38, Etching Characteristics of Ti / Al / Ti Laminated Film]
A substrate in which Ti (100 nm) / Al (360 nm) / Ti (50 nm) was sequentially formed on a glass substrate by a sputtering method was prepared. Next, it patterned using a resist on the Ti / Al / Ti metal laminated film board | substrate, and the said board | substrate was immersed in the etching liquid as described in Examples 1-38 described in Tables 1-3 (temperature: 40 degreeC). , Stirring speed: 500 rpm, beaker volume: 100 ml, immersion time: JET (just etching time) +30 seconds, substrate size: 1 cm × 1.5-2 cm. Thereafter, the substrate was washed with ultrapure water, dried by nitrogen blowing, and the substrate shape was observed with an electron microscope. The results are shown in Tables 1-3. In addition, pH is measured about the etching liquid of room temperature. In Tables 1 to 3, the remaining component of each etching solution was water.

[Comparative Examples 1-3, Etching Characteristics of Ti / Al / Ti Laminated Film]
The substrate was etched and observed in the same manner as in Examples 1-38, except that the composition of the etching solution was changed to the compositions described in Comparative Examples 1-3 described in Tables 1-3. The results are shown in Tables 1-3.

[Examples 1 to 38, solubility of metal oxide film containing In]
Various metal oxide substrates in which ITO (60 nm), IZO (100 nm), and IGZO (70 nm) were formed on a glass substrate by a sputtering method were prepared. Next, it patterned using the resist on the metal oxide board | substrate, and the metal oxide board | substrate was immersed in the etching liquid of Examples 1-38 of Tables 1 and 2 (temperature: 40 degreeC, stirring speed: 500 rpm). , Beaker volume: 100 ml, immersion time: 10-15 seconds (Examples 1-15), 10-15 seconds (Examples 17-25), 30-60 (Examples 26-38), substrate size: 1 cm × 1 .5 to 2 cm). Thereafter, the substrate was washed with ultrapure water, dried by nitrogen blowing, the resist was peeled off, and the etching amount of each metal oxide film was measured with a step gauge. The results are shown in Tables 1 to 3 as the etching rate (nm / min) of the metal oxide film.

[Comparative Examples 1 to 3, solubility of In-containing metal oxide film]
The composition of the etching solution was changed to the composition described in Comparative Examples 1 to 3 described in Tables 1 to 3, and the immersion time was 10 seconds (Comparative Example 1), 30 seconds (Comparative Example 2), and 5 to 10 seconds (Comparative Example). Except for 3), the measurement was performed by etching the metal oxide film on the substrate in the same manner as in Examples 1-38. The results are shown in Tables 1-3.

  As is apparent from Tables 1 to 3, by etching using the etching solution containing the predetermined additive of the present invention, damage to the metal oxide film can be suppressed, and Ti etching can be performed without reducing the etching performance of the etching solution. It was possible to perform batch etching of / Al / Ti. Therefore, when four layers of Ti / Al / Ti / metal oxide film are laminated using the etching solution of the present invention, the metal oxide film has high selectivity with respect to the underlying metal oxide film. Ti / Al / Ti can be satisfactorily etched while preventing dissolution of the oxide layer.

  The etching solution composition of the present invention can be used as an etching solution for a metal laminate film in forming a gate, a source and a drain electrode in a semiconductor manufacturing process, particularly in a flat panel display manufacturing process. It is.

Claims (10)

A Ti-containing layer of a metal laminated film including a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In; An etching solution composition for collectively etching an Al-containing layer,
A fluorine compound;
Including one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds,
The etching solution composition which is acidic.   The etching solution according to claim 1, comprising one or more selected from the group consisting of hydrofluoric acid, ammonium fluoride, sodium fluoride, hexafluorosilicic acid and tetrafluoroboric acid as the fluorine compound. Composition.   The etching solution composition according to claim 1 or 2, comprising one or more selected from the group consisting of iron salts, zirconium salts, tin salts, alkali metal salts, and alkaline earth metal salts as metal salts. .   The etching solution composition according to claim 3, wherein the alkali metal salt is sodium acetate and / or potassium acetate.   The etching liquid composition as described in any one of Claims 1-4 containing an alcohol compound and / or a carboxylic acid compound as an organic solvent.   The etching liquid composition as described in any one of Claims 1-5 containing 1 type, or 2 or more types selected from the group which consists of ammonium nitrate, ammonium phosphate, ammonium sulfate, and ammonium acetate as ammonium salt.   The etching solution composition according to any one of claims 1 to 6, wherein the metal oxide layer contains at least one element selected from the group consisting of Zn, Al, Ga, and Sn.   The etching solution composition according to any one of claims 1 to 7, wherein the pH is 4.0 or less.   Furthermore, the etching liquid composition as described in any one of Claims 1-8 containing any 1 type, or 2 or more types of acids selected from the group which consists of nitric acid, hydrochloric acid, a sulfuric acid, methanesulfonic acid, and perchloric acid. object. A Ti-containing layer of a metal laminated film including a Ti-containing layer made of Ti or an alloy containing Ti as a main component, an Al-containing layer made of Al or an alloy containing Al as a main component, and a metal oxide layer containing In; A step of batch etching the Al-containing layer with an etchant composition;
Here, the etching solution composition comprises a fluorine compound and one or more selected from the group consisting of phosphorus oxoacids, metal salts, organic solvents, ammonium salts and quaternary ammonium compounds, A method for etching a metal laminate film, which is acidic.