Etching composition for copper-based metal film, copper-based metal wiring and thin film transistor array substrate

Abstract

This invention provides an etching composition for copper-based metal films, copper-based metal wiring, and a thin-film transistor array substrate. The etching composition for copper-based metal films comprises hydrogen peroxide, a fluorine-containing compound, an azole compound, a water-soluble compound having nitrogen atoms and carboxyl groups, a phosphate compound, and a sulfate compound. The phosphate compound and sulfate compound are ammonium salts of phosphoric acid and sulfuric acid, respectively, and the Y value, defined by a specific mathematical formula 1, is less than 16. The etching composition of this invention does not produce precipitates and can simultaneously etch copper-based films, molybdenum alloy films, and silicon films with excellent etching characteristics.

Description

Technical Field

[0001] The present invention relates to an etching composition for a copper-based metal film, and more particularly to an etching composition for a copper-based metal film that does not generate precipitates and can etch a copper-based film, a molybdenum alloy film, and a silicon film simultaneously with excellent etching properties. Background Art

[0002] A liquid crystal layer and wiring for transmitting signals to OLED elements are formed on a thin film transistor (TFT) substrate of a liquid crystal display device (LCD) and an organic light emitting diode (OLED) display device. The wiring of the thin film transistor substrate includes gate wiring and data wiring. The gate wiring includes a gate line for applying a gate signal and a gate electrode of a thin film transistor, and the data wiring includes a data line connected to the gate wiring and applying a data signal, and a source electrode and a drain electrode constituting a data electrode of the thin film transistor.

[0003] As such wiring, copper metal, which has low resistance and no environmental problems, is generally used. However, copper has problems such as low adhesion to the glass substrate and diffusion to the lower film, so molybdenum is used as the lower barrier metal at the same time.

[0004] Such metal wiring is patterned into wiring by an etching process. Conventionally, an etching composition used for etching a multilayer metal film composed of a copper / molybdenum (alloy) film contains a fluorine-containing compound to etch the molybdenum (alloy) film and contains citric acid as a processing number increase agent [refer to Korean Patent Publication No. 10-2015-0004972].

[0005] However, the above etching composition cannot etch a silicon film, and thus there is a limitation in the process that a separate dry etching process is required.

[0006] In addition, when precipitates are generated during the etching process, problems such as an increase in the defect rate and the need for productive maintenance (PM) of equipment for removing the precipitates are caused.

[0007] Therefore, there is a need to develop an etching composition for a copper-based metal film that does not generate precipitates and can etch a copper-based film, a molybdenum alloy film, and a silicon film all at once with excellent etching properties. Summary of the invention

[0008] Issues to be solved

[0009] An object of the present invention is to provide an etching composition for a copper-based metal film which does not generate precipitates and can etch a copper-based film, a molybdenum alloy film, and a silicon film simultaneously with excellent etching properties.

[0010] Another object of the present invention is to provide a copper-based metal wiring formed using the above-mentioned etching composition.

[0011] Another object of the present invention is to provide a thin film transistor array substrate including the copper-based metal wiring.

[0012] Solution to the problem

[0013] In one aspect, the present invention provides an etching composition for copper-based metal films, comprising hydrogen peroxide, a fluorine-containing compound, an azole compound, a water-soluble compound having a nitrogen atom and a carboxyl group, a phosphate compound, and a sulfate compound.

[0014] The above-mentioned phosphate compound and sulfate compound are ammonium salts of phosphoric acid and sulfuric acid, respectively.

[0015] The Y value defined by the following mathematical formula 1 is less than 16.

[0016] [Mathematical formula 1]

[0017] Y=(A+B) / (C+D)

[0018] In the above formula,

[0019] A is the content of sulfate compounds,

[0020] B is the content of water-soluble compounds having nitrogen atoms and carboxyl groups,

[0021] C is the content of phosphate compounds,

[0022] D is the content of fluorine-containing compounds.

[0023] In one embodiment of the present invention, the copper-based metal film may be a single-layer film of copper or a copper alloy; or a multilayer film comprising one or more films selected from copper films and copper alloy films and one or more films selected from molybdenum films and molybdenum alloy films.

[0024] The etching composition for a copper-based metal film according to one embodiment of the present invention can etch a silicon film together with a copper-based metal film.

[0025] In one embodiment of the present invention, the above-mentioned silicon film can be one or more films selected from amorphous silicon film (a-Si), hydrogenated amorphous silicon film (a-Si:H), N-type doped amorphous silicon film (n+a-Si) and N-type doped hydrogenated amorphous silicon film (n+a-Si:H).

[0026] The copper-based metal film etching composition according to one embodiment of the present invention may further include one or more of a polyol-type surfactant and an acetate compound.

[0027] The etching composition for copper-based metal films according to one embodiment of the present invention may contain 5 to 25 wt% of hydrogen peroxide, 0.001 to 0.4 wt% of a fluorine-containing compound, 0.1 to 5 wt% of an azole compound, 0.1 to 3.5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2 wt% of a phosphate compound, and 0.1 to 2 wt% of a sulfate compound, relative to the total weight of the composition, and may contain water in an amount that makes the total weight of the composition 100 wt%.

[0028] In another aspect, the present invention provides a copper-based metal wiring formed using the above-mentioned copper-based metal film etching composition.

[0029] In another aspect, the present invention provides a thin film transistor array substrate including the copper-based metal wiring.

[0030] A thin film transistor array substrate according to an embodiment of the present invention may include a silicon semiconductor layer.

[0031] Effects of the Invention

[0032] The copper-based metal film etching composition of the present invention does not generate precipitates and can etch a copper-based film, a molybdenum alloy film, and a silicon film simultaneously with excellent etching properties. DETAILED DESCRIPTION

[0033] Hereinafter, the present invention will be described in more detail.

[0034] One embodiment of the present invention relates to an etching composition for copper-based metal films, which comprises hydrogen peroxide (A), a fluorine-containing compound (B), an azole compound (C), a water-soluble compound having a nitrogen atom and a carboxyl group (D), a phosphate compound (E) and a sulfate compound (F), wherein the phosphate compound and the sulfate compound are ammonium salts of phosphoric acid and sulfuric acid, respectively, and the Y value defined by the following mathematical formula 1 is less than 16.

[0035] [Mathematical formula 1]

[0036] Y=(A+B) / (C+D)

[0037] In the above formula,

[0038] A is the content of sulfate compounds,

[0039] B is the content of water-soluble compounds having nitrogen atoms and carboxyl groups,

[0040] C is the content of phosphate compounds,

[0041] D is the content of fluorine-containing compounds.

[0042] The copper-based metal film etching composition according to one embodiment of the present invention has a Y value defined by the above formula 1 of less than 16, for example, 3 or more and less than 16, preferably 4 or more and less than 14, and more preferably 5 or more and less than 12.

[0043] If the Y value defined by the above mathematical formula 1 satisfies the above range, even if the number of processed sheets increases, the skew uniformity is excellent, the taper angle (T / A) change rate is small, the residue generation can be suppressed, and the etching characteristics for the lower silicon film can be ensured, so that wet etching can be performed instead of the dry etching process.

[0044] When the Y value defined by the above-mentioned Mathematical Formula 1 is 16 or more, as the number of processed sheets increases, the offset uniformity may decrease, the taper angle variation rate may increase, residue may be generated, or it may be difficult to ensure the etching characteristics for the lower silicon film.

[0045] In one embodiment of the present invention, the copper-based metal film contains copper in the constituent components of the film and may be a single-layer film of copper or a copper alloy; or a multilayer film comprising one or more films selected from copper films and copper alloy films and one or more films selected from molybdenum films and molybdenum alloy films.

[0046] The above-mentioned copper alloy refers to an alloy of copper and one or more metals selected from aluminum (Al), magnesium (Mg), calcium (Ca), titanium (Ti), silver (Ag), chromium (Cr), manganese (Mn), iron (Fe), zirconium (Zr), niobium (Nb), molybdenum (Mo), palladium (Pd), hafnium (Hf), tantalum (Ta) and tungsten (W), and is a concept that also includes copper nitride or copper oxide.

[0047] The above-mentioned molybdenum alloy refers to an alloy of molybdenum and one or more metals selected from aluminum (Al), niobium (Nb), tungsten (W), titanium (Ti) and nickel (Ni), and is a concept that also includes molybdenum nitride or molybdenum oxide.

[0048] As examples of the above-mentioned multilayer film, there can be cited two-layer films such as copper / molybdenum film, copper / molybdenum alloy film, copper alloy / molybdenum alloy film, etc.; three-layer films such as molybdenum / copper / molybdenum film, molybdenum alloy / copper / molybdenum alloy film, etc. The above-mentioned copper / molybdenum film refers to a film comprising a molybdenum layer and a copper layer formed on the above-mentioned molybdenum layer, the above-mentioned copper / molybdenum alloy film refers to a film comprising a molybdenum alloy layer and a copper layer formed on the above-mentioned molybdenum alloy layer, the above-mentioned copper alloy / molybdenum alloy film refers to a film comprising a molybdenum alloy layer and a copper alloy layer formed on the above-mentioned molybdenum alloy layer, the above-mentioned molybdenum / copper / molybdenum film refers to a film comprising a molybdenum layer, a copper layer formed on the above-mentioned molybdenum layer, and a molybdenum layer formed on the above-mentioned copper layer, the above-mentioned molybdenum alloy / copper / molybdenum alloy film refers to a film comprising a molybdenum alloy layer, a copper layer formed on the above-mentioned molybdenum alloy layer, and a molybdenum alloy layer formed on the above-mentioned copper layer, and the above-mentioned molybdenum alloy / copper / molybdenum alloy film refers to a film comprising a molybdenum alloy layer, a copper alloy layer formed on the above-mentioned molybdenum alloy layer, and a molybdenum alloy layer formed on the above-mentioned copper layer.

[0049] In particular, the etching composition of the present invention can be applied to a multilayer film including one or more films selected from copper films and copper alloy films and one or more films selected from molybdenum films and molybdenum alloy films.

[0050] The thickness of the copper film and the copper alloy film can be The range of The thickness of the molybdenum film and the molybdenum alloy film can be The range of range.

[0051] In one embodiment of the present invention, the copper-based metal film may be formed on a glass substrate or a silicon film.

[0052] The etching composition for a copper-based metal film according to one embodiment of the present invention can etch a silicon film together with a copper-based metal film.

[0053] Therefore, the copper-based metal film etching composition according to one embodiment of the present invention can etch the gate electrode, gate wiring, source / drain electrodes, data wiring, and underlying silicon film of a display device composed of a copper-based metal film and a silicon film all at once.

[0054] The above-mentioned silicon film can be one or more films selected from amorphous silicon film (a-Si), hydrogenated amorphous silicon film (a-Si:H), N-type doped amorphous silicon film (n+a-Si) and N-type doped hydrogenated amorphous silicon film (n+a-Si:H).

[0055] Hereinafter, the constituent components of the etching composition according to one embodiment of the present invention will be described in more detail.

[0056] Hydrogen peroxide (A)

[0057] In one embodiment of the present invention, the hydrogen peroxide (H 2 O 2 ) (A) is a main oxidant that affects etching of the copper-based metal film.

[0058] The content of the hydrogen peroxide may be 5 to 25% by weight, preferably 13 to 23% by weight, relative to the total weight of the composition. When the content of the hydrogen peroxide is less than 5% by weight, the copper-based metal film may not be etched or the etching speed may become very slow. When the content of the hydrogen peroxide is greater than 25% by weight, the etching speed may be accelerated as a whole, so it may be difficult to control the process, and the thermal stability may be greatly reduced due to the increase in copper ions.

[0059] Fluorinated compounds (B)

[0060] In one embodiment of the present invention, the fluorine-containing compound (B) is an oxidant that affects the etching rate of the molybdenum (alloy) film, and plays a role in adjusting the etching rate of the molybdenum (alloy) film and suppressing the generation of residues.

[0061] The above-mentioned fluorine-containing compound refers to a compound that can dissociate in water or the like to provide fluorine ions or polyatomic fluorine ions. As the above-mentioned fluorine-containing compound, a fluorine-containing compound commonly used in the art can be used, for example, hydrogen fluoride (HF), sodium fluoride (NaF), ammonium fluoride (NH4F), ammonium bifluoride (NH4F2), ammonium fluoride borate (NH4BF4), ammonium bifluoride (NH4FHF), potassium fluoride (KF), potassium bifluoride (KHF2), aluminum fluoride (AlF3), tetrafluoroboric acid (HBF4), etc., which can be used alone or in a mixture of two or more.

[0062] The content of the fluorine-containing compound may be 0.001 to 0.4 weight %, preferably 0.1 to 0.35 weight %, relative to the total weight of the composition. When the content of the fluorine-containing compound is less than 0.001 weight %, the etching rate of the molybdenum (alloy) film may be slowed down, resulting in residues. When the content of the fluorine-containing compound is greater than 0.4 weight %, the etching rates of the molybdenum (alloy) film and the silicon film may be too fast, resulting in significant etching of the glass substrate and making it difficult to apply to the rework process.

[0063] In addition, when the content of the fluorine-containing compound is greater than 0.4 wt%, Si precipitates may be generated. For example, the Si precipitates may be generated in the form of Na2[SiF6] or K2[SiF6], which may cause precipitates to be generated on the etching equipment (etcher), increase the defect rate during etching, and require PM of the equipment.

[0064] SiO2+6F-→SiF6 2- +O2

[0065] SiF62- +2Na→Na2[SiF6]

[0066] SiF6 2- +2K→K2[SiF6]

[0067] Azole compound (C)

[0068] In one embodiment of the present invention, the azole compound (C) adjusts the etching rate of the copper-based metal film, reduces the critical dimension loss (CD loss) of the pattern, that is, side etch, and improves the margin in the process.

[0069] As the above-mentioned azole compound, any azole compound used in the art can be used without particular limitation, and for example, an azole compound having 1 to 30 carbon atoms is preferred. As the above-mentioned azole compound, triazole compounds, aminotetrazolyl compounds, imidazole compounds, indole compounds, purine compounds, pyrazole compounds, pyridine compounds, pyrimidine compounds, pyrrole compounds, pyrrolidine compounds, pyrroline compounds, etc. can be used, and specifically, 5-aminotetrazole (5-aminotetrazole), benzotriazole (benzotriazole), tolyltriazole (tolyltriazole), pyrazole (pyrazole), pyrrole (pyrrole), imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-aminoimidazole, 4-methylimidazole, 4-ethylimidazole, methyltriazole, methyltetrazolyl, 4-propylimidazole, etc. can be used. These can be used alone or in a mixture of two or more.

[0070] The content of the azole compound may be 0.1 to 5% by weight, preferably 0.1 to 1.5% by weight, relative to the total weight of the composition. When the content of the azole compound is less than 0.1% by weight, the etching rate may increase and a significant loss of critical dimensions may occur. When the content of the azole compound is greater than 5% by weight, the etching rate may be too slow and there may be a loss of process time, and etching residues may be generated.

[0071] Water-soluble compound having nitrogen atom and carboxyl group (D)

[0072] In one embodiment of the present invention, the water-soluble compound (D) having a nitrogen atom and a carboxyl group prevents the self-decomposition reaction of hydrogen peroxide that may occur when the etching composition is stored and prevents the etching characteristics from changing when etching a large number of substrates. Generally speaking, in the case of an etching composition using hydrogen peroxide, hydrogen peroxide will self-decompose during storage, so that its storage time is not long, and it may explode. On the other hand, in the case of the water-soluble compound having a nitrogen atom and a carboxyl group, the decomposition rate of hydrogen peroxide is reduced by nearly 10 times, which is conducive to ensuring storage time and stability. In particular, in the case of a copper layer, when a large amount of copper ions remain in the etching composition, a passivation film may be formed and further etching cannot be performed after oxidation and blackening, but such a phenomenon can be prevented when the above-mentioned compound (D) is added.

[0073] Examples of the water-soluble compound having a nitrogen atom and a carboxyl group include alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrilotriacetic acid and sarcosine, and these can be used alone or in combination of two or more.

[0074] The content of the water-soluble compound having a nitrogen atom and a carboxyl group may be in the range of 0.1 to 3.5% by weight, preferably in the range of 0.5 to 3.0% by weight, relative to the total weight of the composition. When the content of the above-mentioned compound is less than 0.1% by weight, a passivation film may be formed after etching a large number of substrates (about 500 sheets) and sufficient process margin may not be easily obtained. When the content is greater than 3.5% by weight, the etching speed of the molybdenum-containing film may be slowed down to generate residues, resulting in loss of process time.

[0075] Phosphate compounds (E)

[0076] In one embodiment of the present invention, the phosphate compound (E) is a component that improves the tapered profile of the pattern, and an ammonium salt of phosphoric acid is used. In particular, in the present invention, by using an ammonium salt as the phosphate compound, the solubility in water is high and the generation of precipitates can be suppressed. For example, when a metal salt is used instead of an ammonium salt as the phosphate compound, Al precipitation is generated from MoAlTi in the molybdenum (alloy) film. The precipitate can be generated in the form of Na3AlF6 or K3AlF6, and there is a disadvantage that precipitates are generated on the etching equipment and the defective rate increases during the etching process, and PM of the equipment is required.

[0077] Al3+ +6F-→AlF6 3-

[0078] AlF6 3- +3Na + →Na3AlF6 (precipitate is generated)

[0079] AlF6 3- +3K + →K3AlF6 (precipitate is generated)

[0080] AlF6 3- +NH4 + →(NH4)3AlF6 (no precipitate)

[0081] The ammonium salt of phosphoric acid is a salt in which one or two hydrogen ions of phosphoric acid are replaced by ammonium ions. Examples thereof include ammonium dihydrogen phosphate and diammonium hydrogen phosphate, which can be used alone or in a mixture of two or more.

[0082] The content of the phosphate compound may be in the range of 0.01 to 0.2 weight %, preferably in the range of 0.02 to 0.15 weight %, relative to the total weight of the composition. When the content of the phosphate compound is less than 0.01 weight %, the etching profile may be deteriorated, and when it is greater than 0.2 weight %, the taper angle of the copper-based metal film may increase, the etching rate of the copper-based metal film may increase, or the etching rate of the molybdenum (alloy) film may slow down. In addition, if the content of the phosphate compound deviates from the above range, the etching rate of the lower silicon film may slow down.

[0083] Sulfate compounds (F)

[0084] In one embodiment of the present invention, the sulfate compound (F) is an ammonium salt of sulfuric acid as a component that improves the tapered profile of the pattern and adjusts the etching rate of the copper-based metal film. In particular,

[0085] In the present invention, by using ammonium salt as the sulfate compound, the solubility in water is high and the generation of precipitates can be suppressed. For example, when a metal salt is used instead of an ammonium salt as the sulfate compound, Al precipitation is generated from MoAlTi in the molybdenum (alloy) film. The precipitate can be generated in the form of Na3AlF6 or K3AlF6, and there is a disadvantage that the precipitate is generated on the etching equipment, the defect rate increases during the etching process, and PM of the equipment is required.

[0086] Al 3+ +6F- →AlF6 3-

[0087] AlF6 3- +3Na + →Na3AlF6 (precipitate is generated)

[0088] AlF6 3- +3K + →K3AlF6 (precipitate is generated)

[0089] AlF6 3- +NH4 + →(NH4)3AlF6 (no precipitate)

[0090] The ammonium salt of sulfuric acid is a salt in which one or two hydrogen ions of sulfuric acid are replaced by ammonium ions. Examples thereof include ammonium sulfate and ammonium bisulfate, which can be used alone or in a mixture of two or more.

[0091] The content of the sulfate compound may be in the range of 0.1 to 2 wt %, preferably in the range of 0.1 to 1.6 wt %, relative to the total weight of the composition. When the content of the sulfate compound is less than 0.1 wt %, the etching force is insufficient and sufficient etching may not be achieved, and when the content is greater than 2 wt %, the etching speed is accelerated as a whole, so process control may be difficult.

[0092] Polyol surfactant (G)

[0093] The etching composition for copper-based metal films of one embodiment of the present invention may further contain a polyol-type surfactant (G) to reduce surface tension and improve etching uniformity. In addition, the polyol-type surfactant (G) can play a role in suppressing the activity of copper ions and decomposition reaction of hydrogen peroxide by surrounding the copper ions dissolved from the etching composition after copper film etching. If the activity of copper ions is reduced in this way, a stable process can be performed without heat generation during the use of the etching composition.

[0094] Examples of the polyol surfactant include glycerol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, etc. These may be used alone or in combination of two or more.

[0095] The content of the polyol surfactant may be in the range of 0.001 to 5% by weight, preferably in the range of 1.0 to 3.0% by weight, relative to the total weight of the composition. When the content of the polyol surfactant is less than 0.001% by weight, the decomposition of hydrogen peroxide may be accelerated, and when the content is greater than 5% by weight, a large amount of foam may be generated.

[0096] Acetate compounds (H)

[0097] The etching composition for copper-based metal films according to one embodiment of the present invention may further contain an acetate compound (H) to adjust the etching rate. The acetate compound (H) serves to increase the pH and adjust the etching rate of the copper-based metal film so that it does not become too high.

[0098] The acetate compound may be a salt in which the hydrogen ions of acetic acid are replaced by alkali metal ions, alkaline earth metal ions or ammonium ions, but is not limited thereto. Specific examples include sodium acetate, potassium acetate, ammonium acetate, etc., which may be used alone or in a mixture of two or more.

[0099] The content of the acetate compound may be 0.1 to 2% by weight, preferably 0.2 to 1.0% by weight, relative to the total weight of the composition. When the content of the acetate compound is less than 0.1% by weight, the etching rate is increased as a whole, so it may be difficult to control the process. When the content of the acetate compound is greater than 2% by weight, the etching rate is slow and the production efficiency may be reduced.

[0100] In addition, the etching composition of one embodiment of the present invention may contain water in an amount that makes the total weight of the composition 100 wt%. In the present invention, the water is not particularly limited, but is preferably deionized water, and more preferably deionized water having a resistivity of 18 MΩ·cm or more, indicating the degree of ion removal in water.

[0101] The "balance" of the present invention refers to the balance that makes the total weight of the composition containing the essential components of the present invention and other additional components 100% by weight, and the meaning of the above "balance" does not limit the composition of the present invention to not containing additional components.

[0102] The etching composition for copper-based metal films according to one embodiment of the present invention may contain 5 to 25 wt% of hydrogen peroxide, 0.001 to 0.4 wt% of a fluorine-containing compound, 0.1 to 5 wt% of an azole compound, 0.1 to 3.5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2 wt% of a phosphate compound, and 0.1 to 2 wt% of a sulfate compound, relative to the total weight of the composition, and may contain water in an amount that makes the total weight of the composition 100 wt%.

[0103] The etching composition for copper-based metal films according to one embodiment of the present invention may contain 5 to 25 wt% of hydrogen peroxide, 0.001 to 0.4 wt% of a fluorine-containing compound, 0.1 to 5 wt% of an azole compound, 0.1 to 3.5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2 wt% of a phosphate compound, 0.1 to 2 wt% of a sulfate compound, and 0.001 to 5 wt% of a polyol-type surfactant, relative to the total weight of the composition, and may contain water in an amount that makes the total weight of the composition 100 wt%.

[0104] The etching composition for copper-based metal films according to one embodiment of the present invention may contain 5 to 25 wt% of hydrogen peroxide, 0.001 to 0.4 wt% of a fluorine-containing compound, 0.1 to 5 wt% of an azole compound, 0.1 to 3.5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2 wt% of a phosphate compound, 0.1 to 2 wt% of a sulfate compound, and 0.1 to 2 wt% of an acetate compound, relative to the total weight of the composition, and may contain water in an amount that makes the total weight of the composition 100 wt%.

[0105] The etching composition for copper-based metal films according to one embodiment of the present invention may contain 5 to 25 wt% of hydrogen peroxide, 0.001 to 0.4 wt% of a fluorine-containing compound, 0.1 to 5 wt% of an azole compound, 0.1 to 3.5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2 wt% of a phosphate compound, 0.1 to 2 wt% of a sulfate compound, 0.001 to 5 wt% of a polyol-type surfactant, and 0.1 to 2 wt% of an acetate compound, relative to the total weight of the composition, and may contain water in an amount that makes the total weight of the composition 100 wt%.

[0106] The etching composition according to one embodiment of the present invention may further contain additives commonly used in the art, such as a sequestering agent, an anticorrosive agent, and the like, in addition to the above-mentioned components.

[0107] The above-mentioned components used in the etching composition according to one embodiment of the present invention can be produced by a generally known method, and preferably have a purity that can be used in semiconductor processes.

[0108] The etching composition of one embodiment of the present invention can achieve a tapered profile with excellent etching uniformity and straightness when etching a copper-based metal film. In addition, the etching composition of one embodiment of the present invention does not produce residue, so there are no problems such as electrical short circuits, poor wiring or reduced brightness. In addition, the etching composition of one embodiment of the present invention can etch the gate electrode, gate wiring, source electrode / drain electrode, data wiring and the silicon film at the bottom together. Therefore, the etching composition of one embodiment of the present invention can perform a wet etching process with only one etching composition instead of using several etching compositions, so the process can be simplified and the process yield can be maximized, and since it can replace the dry etching process, the process time and cost can be reduced.

[0109] Therefore, the copper-based metal film etching composition according to one embodiment of the present invention can be used very effectively in manufacturing a thin film transistor array substrate having a large screen and / or high brightness circuit, particularly a thin film transistor array substrate for a liquid crystal display device.

[0110] One embodiment of the present invention relates to a copper-based metal wiring formed using the above-mentioned etching composition for a copper-based metal film.

[0111] The copper-based metal wiring according to one embodiment of the present invention can be produced by using the above-mentioned etching composition and performing an etching process generally known in the art.

[0112] For example, the copper-based metal wiring according to one embodiment of the present invention can be manufactured by performing an etching process including the following steps: forming a copper-based metal film on a substrate; forming a photoresist film on the copper-based metal film and then patterning the film; and etching the copper-based metal film using the etching composition. Optionally, the step of forming a silicon film before forming the copper-based metal film on the substrate may be further included.

[0113] One embodiment of the present invention relates to a thin film transistor array substrate including the above-mentioned copper-based metal wiring. For example, the thin film transistor array substrate of the present invention can be a thin film transistor array substrate for a display device, and in particular, can be a thin film transistor array substrate for a display device including a silicon semiconductor layer.

[0114] A thin film transistor array substrate according to one embodiment of the present invention can be manufactured as follows, that is, in a common process in the art, such as including a) the step of forming a gate electrode on a substrate; b) the step of forming a gate insulating layer on a substrate including the gate electrode; c) the step of forming a semiconductor layer (silicon film) on the gate insulating layer; d) the step of forming a source electrode / drain electrode on the semiconductor layer; and e) the step of forming a pixel electrode connected to the drain electrode, in the above steps a), c) and / or d), etching is performed using the etching composition to form each electrode.

[0115] In one embodiment of the present invention, the display device may be a liquid crystal display device or an OLED, but is not limited thereto.

[0116] The present invention will be described in more detail below by way of examples, comparative examples and experimental examples. It will be apparent to those skilled in the art that these examples, comparative examples and experimental examples are only used to illustrate the present invention, and the scope of the present invention is not limited thereto.

[0117] Embodiment and comparative example:

[0118] As shown in Table 1 below, the components were mixed and the remainder of water was added to make the whole 100 wt %, thereby producing an etching composition (unit: wt %).

[0119] [Table 1]

[0120]

[0121] B-1: Ammonium bifluoride

[0122] C-1: 5-aminotetrazole

[0123] D-1: Iminodiacetic acid

[0124] E-1: ammonium dihydrogen phosphate

[0125] E-2: Sodium dihydrogen phosphate

[0126] E-3: Potassium dihydrogen phosphate

[0127] F-1: ammonium sulfate

[0128] F-2: Sodium sulfate

[0129] F-3: Potassium sulfate

[0130] G-1: triethylene glycol

[0131] H-1: ammonium acetate

[0132] Experimental Example 1:

[0133] For the produced etching compositions, the Y value defined by the following Mathematical Formula 1 was calculated and shown in Table 2 below.

[0134] [Mathematical formula 1]

[0135] Y=(A+B) / (C+D)

[0136] In the above formula,

[0137] A is the content of sulfate compounds,

[0138] B is the content of water-soluble compounds having nitrogen atoms and carboxyl groups,

[0139] C is the content of phosphate compounds,

[0140] D is the content of fluorine-containing compounds.

[0141] In order to evaluate the etching performance of the produced etching composition, copper-based metal wiring was produced as follows, and the etching properties at that time were measured.

[0142] <Manufacturing of Copper Metal Wiring>

[0143] On a glass substrate (100mm×100mm) N-type doped amorphous silicon film (n+a-Si) is evaporated with a thickness of 1000 mm, and Cu / MoAlTi is evaporated on the above film in sequence. The double-layer film is then subjected to a photolithography process to form a pattern, followed by an etching process.

[0144] At this time, the etching step uses a spray etching experimental device (model name: ETCHER (TFT), SEMES), and the temperature of the etching composition during the etching step is set to about 33° C. The etching time varies depending on the etching temperature, but is usually about 90 seconds.

[0145] (1) Etching rate of copper metal film

[0146] The etching rate was calculated by dividing the thickness of the copper (Cu) metal film by the etching time required for the copper metal film to disappear due to etching, and was evaluated according to the following evaluation criteria.

[0147] <Etching Rate Evaluation Criteria>

[0148] ○: Good, / Second

[0149] ×: Defective, / Second, / Second

[0150] (2) Offset change and cone angle change

[0151] After etching, the etched cross section was observed using SEM (S-4700, Hitachi), and the offset change and taper angle change were evaluated according to the following evaluation criteria. At this time, the offset change and taper angle change were measured while increasing the number of processed sheets and the copper concentration in the etching composition from 0 ppm to 5000 ppm.

[0152] <Offset Change Evaluation Criteria>

[0153] ○: Good, less than Δ0.15 μm

[0154] ×: Defective, Δ0.15 μm or more

[0155] <Cone Angle Change Evaluation Criteria>

[0156] ○: Good, Δ10° or less

[0157] ×: Defective, greater than Δ10°

[0158] (3) Molybdenum alloy film residue

[0159] After etching, it was observed whether or not residue of the MoAlTi film was generated.

[0160] (4) Glass substrate damage

[0161] The glass substrate was etched for 100 seconds, and the thickness after etching was measured to measure the etching rate.

[0162] <Glass Substrate Damage Evaluation Criteria>

[0163] ○: Good, / second or less

[0164] ×: Defective, greater than / Second

[0165] (5) Silicon film etching speed

[0166] After the copper-based metal film was etched from the surface of the substrate, the above-mentioned substrate was etched at intervals of 10 seconds from the time when the silicon film was exposed. Then, using SEM (manufactured by Hitachi, model name S-4700), the etching thickness after etching was divided by the etching time to calculate the etching rate, and evaluation was performed according to the following evaluation criteria.

[0167] <Silicon film etching rate evaluation criteria>

[0168] ○: Good, / second or more, / second or less

[0169] ×: Defective, less than / second, greater than / Second

[0170] (6) Precipitate Generation

[0171] The presence or absence of precipitates was observed before and after the etching step.

[0172] The results of the measured etching properties are shown in Table 2 below.

[0173] [Table 2]

[0174]

[0175] As shown in the above Table 2, it was confirmed that the copper-based metal film etching compositions of Examples 1 to 7 in which the Y value defined by Mathematical Formula 1 was less than 16 and the phosphate compound and the sulfate compound were ammonium salts of phosphoric acid and sulfuric acid, respectively, did not produce precipitates and exhibited excellent etching rate characteristics for copper-based metal films. Even if the number of processed sheets increased, the changes in offset and taper angle were small, and the etching rate characteristics of silicon films were also excellent.

[0176] In addition, it was confirmed that the copper-based metal film etching compositions of Comparative Examples 1 to 4 and 7 to 10 in which the Y value defined by Mathematical Formula 1 was 16 or more or the phosphate compound or sulfate compound was a metal salt of phosphoric acid or sulfuric acid could not simultaneously ensure the precipitate generation characteristics, the etching rate characteristics for the copper-based metal film, the change in the offset and taper angle with the increase in the number of processed sheets, and the etching rate characteristics for the silicon film.

[0177] On the other hand, even though the Y value was less than 16, the copper-based metal film etching composition of Comparative Example 5 in which the water-soluble compound having nitrogen atoms and carboxyl groups was excessive produced molybdenum alloy film residues, and even though the Y value was less than 16, the copper-based metal film etching composition of Comparative Example 6 in which the fluorine-containing compound was excessive could not be used in the process because the glass substrate was severely damaged.

[0178] The above describes in detail certain parts of the present invention, but it is obvious to those skilled in the art that such specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. Those skilled in the art should be able to make various applications and modifications within the scope of the present invention based on the above contents.

[0179] Accordingly, the actual scope of the invention should be determined by the appended claims and their equivalents.

Claims

1. An etching composition for a copper-based metal film, comprising hydrogen peroxide, a fluorine-containing compound, an azole compound, a water-soluble compound having a nitrogen atom and a carboxyl group, a phosphate compound, and a sulfate compound, The phosphate compound and the sulfate compound are ammonium salts of phosphoric acid and sulfuric acid, respectively, The Y value defined by the following mathematical formula 1 is less than 16, The composition comprises 5 to 25% by weight of hydrogen peroxide, 0.001 to 0.4% by weight of a fluorine-containing compound, 0.1 to 5% by weight of an azole compound, 0.1 to 3.5% by weight of a water-soluble compound having a nitrogen atom and a carboxyl group, 0.01 to 0.2% by weight of a phosphate compound, and 0.1 to 2% by weight of a sulfate compound, and contains water in an amount such that the total weight of the composition is 100% by weight. Mathematical formula 1 Y=(A+B) / (C+D) In the formula, A is the content of sulfate compounds, B is the content of water-soluble compounds having nitrogen atoms and carboxyl groups, C is the content of phosphate compounds, D is the content of fluorine-containing compounds.

2. The etching composition for copper-based metal film according to claim 1, wherein the copper-based metal film is a single-layer film of copper or a copper alloy; or a multi-layer film comprising one or more films selected from copper films and copper alloy films and one or more films selected from molybdenum films and molybdenum alloy films. 3 . The etching composition for a copper-based metal film according to claim 1 , which etches a silicon film together with the copper-based metal film. 4 . The etching composition for copper-based metal film according to claim 3 , wherein the silicon film is one or more films selected from amorphous silicon film, hydrogenated amorphous silicon film, N-type doped amorphous silicon film and N-type doped hydrogenated amorphous silicon film. 5 . The etching composition for copper-based metal films according to claim 1 , further comprising at least one of a polyol-type surfactant and an acetate compound. 6 . A copper-based metal wiring formed using the etching composition for a copper-based metal film according to claim 1 . 7 . A thin film transistor array substrate comprising the copper-based metal wiring according to claim 6 . The thin film transistor array substrate according to claim 7 , comprising a silicon semiconductor layer.

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