KR20180009682A - Etching solution composition for metal layers and manufacturing method of display device using the same - Google Patents

Abstract

The present invention relates to an etching composition for metal layers comprising persulfate, a fluorine compound, inorganic acid, methyltetrazole, a chlorine compound, and water, and to a manufacturing method of a display device using the same. An objective of the present invention is to provide an etching solution composition having an excellent etching profile for a metal film. Another objective of the present invention is to provide an etching composition which does not generate precipitates with copper ions produced by copper wiring etching.

Description

[0001] The present invention relates to a metal film etchant composition and a method of manufacturing a display device using the same,

The present invention relates to a metal film etchant composition and a method of manufacturing a display using the same, and more particularly, to a metal film etchant composition comprising persulfate, fluorine compound, inorganic acid, methyltetrazole, chlorine compound and water, And a manufacturing method thereof.

A typical example of an electronic circuit for driving a semiconductor device and a flat panel display device is a thin film transistor (TFT). In the manufacturing process of a TFT-LCD, a metal film is usually formed as a wiring material for gate and source / drain electrodes on a substrate, a photoresist is formed in a selective region of the metal film, and the upper metal film is etched using the photoresist as a mask Process.

A metal film in which aluminum or an alloy thereof and another metal are laminated is used as a wiring material for a gate and a source / drain electrode. Aluminum is inexpensive and has low resistance, but it is not chemically stable and causes a short-circuit with other conductive layer due to defects such as hillock in the post-process, or an insulating layer due to contact with the oxide layer Thereby causing a malfunction of the liquid crystal panel.

Taking this into consideration, a double metal film of a copper film and a titanium film has been proposed as a wiring material for a gate and a source / drain electrode.

However, in order to etch the double metal film of the copper film and the titanium film, it is necessary to use two different etching solutions for etching each metal film. Particularly, in order to etch a copper film containing copper, a hydrogen peroxide-based etchant or an oxhene etchant is mainly used.

Korean Patent Publication No. 10-2010-0040352 discloses a hydrogen peroxide type etching solution containing hydrogen peroxide, phosphoric acid, phosphate, chelating agent and cyclic amine compound. However, such a hydrogen peroxide etching solution has disadvantages such as disproportionation reaction, which is disadvantageous in that the composition itself is decomposed or is unstable due to a rapid compositional change with time, and the Oxhene etching solution has a disadvantage in that the etching rate is slow and unstable over time.

Particularly, the cyclic amine compound binds to the copper ion generated when the copper film is etched. In this case, when chlorine ions are present in the etching solution, there arises a problem that a poorly soluble precipitate is generated when the chloride ion and the above-mentioned bond react.

Korean Patent Publication No. 10-2010-0040352

An object of the present invention is to provide an etching solution composition having an excellent etching profile for a metal film.

It is another object of the present invention to provide an etchant composition which does not generate precipitates with copper ions produced by copper wiring etching.

Another object of the present invention is to provide an etchant composition excellent in stability over time.

It is another object of the present invention to provide a method of manufacturing a display device using the etchant composition.

In order to achieve the above object,

The present invention provides a metal film etchant composition comprising a persulfate, a fluorine compound, an inorganic acid, methyltetrazole, a chlorine compound, and water.

The present invention also provides a method of manufacturing a display device including a step of etching a metal film with the etchant composition.

The metal film etchant composition of the present invention does not generate precipitates with copper ions, thereby providing a clean process environment and increasing process efficiency.

In addition, the metal film etchant composition of the present invention does not generate precipitates with copper ions, so that the performance deterioration and the defect rate due to precipitates can be reduced.

In addition, the metal film etchant composition of the present invention can be usefully used for manufacturing display devices.

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

The present invention relates to a metal film etchant composition comprising a persulfate, a fluorine compound, an inorganic acid, a methyltetrazole, a chlorine compound and water.

Aminotetrazole (ATZ), one of the constituents of the conventional metal film etchant composition, produced a precipitate (Cu-Cl-ATZ complex) by reactivity with a copper salt and a chlorine compound. The stability of the etchant composition with time was lowered due to the precipitates, and etching failure occurred. Therefore, it is necessary to remove the precipitate, but it is not easy, and the precipitate can not be completely removed owing to the positive effect of the etching property caused by the precipitate.

In order to solve the above problems, the present invention intends to fundamentally control the generation of precipitates by using methyltetrazole (MTZ) instead of the conventional aminotetrazole.

The methyltetrazole does not react with the chlorine compound to generate a precipitate, and accordingly, there is no need to additionally use an inhibitor to control the precipitate. In addition, since precipitates are not generated, a clean process environment can be provided, and the process yield can be improved.

The metal film of the metal film etchant composition is a multilayer film, and the multilayer film is preferably a multilayer film including a titanium film and a copper film.

The multi-layer film including the titanium film and the copper film means a multi-metal film in which a titanium film and a copper film are laminated. Specifically, it includes a double metal film in which a copper film / titanium film is stacked in this order, a titanium film / copper film, and a double metal film in this order. Also, a multi-metal film in which a copper film and a titanium film are alternately stacked in three or more layers such as a ternary metal film of a copper film / titanium film / copper film, a ternary metal film of a titanium film / copper film / titanium film, a copper film / A copper film / a titanium film / a copper film, and the like. At this time, the thickness of the copper film and the titanium film is not particularly limited.

In the present invention, the copper film may be a copper single film composed only of copper, and may be formed of aluminum, magnesium, manganese, beryllium, hafnium, And a copper alloy including at least one selected from the group consisting of tungsten (W) and vanadium (V).

In the present invention, the titanium film may be a single titanium film composed only of titanium, and aluminum, Al, Mg, Mn, beryllium, hafnium, niobium, And a titanium alloy film composed of a titanium alloy including at least one selected from the group consisting of tungsten (W) and vanadium (V).

Hereinafter, the constituent components of the etchant composition of the present invention will be described in more detail.

(A) Persulfate

The persulfate contained in the metal film etchant composition of the present invention is a peroxidizing agent for etching the copper film among the metal films.

Wherein the persulfate is at least one selected from the group consisting of potassium persulfate (K ₂ S ₂ O ₈ ), sodium persulfate (Na ₂ S ₂ O ₈ ) and ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) .

The persulfate is contained in an amount of 0.5 to 20% by weight, preferably 5 to 15% by weight based on the total weight of the etchant composition of the present invention.

When the amount of the persulfate is less than 0.5% by weight, the etching rate is decreased to insufficient etching. If the persulfate is contained in an amount exceeding 20% by weight, the etching rate is too fast to control the etching degree. ).

(B) Fluorine compound

The fluorine compound contained in the metal film etchant composition of the present invention plays a role of etching the titanium film and removing the residues that may be generated by the etching, particularly in the metal film.

The fluorine compound may be a compound that dissociates fluorine ions or polyatomic fluorine ions in a solution. Preferably, the fluorine compound is selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride, and potassium bifluoride.

The fluorine compound is contained in an amount of 0.01 to 2% by weight, preferably 0.01 to 1% by weight based on the total weight of the etchant composition of the present invention.

If the amount of the fluorine compound is less than 0.01% by weight, the etch rate of the titanium film may be lowered to cause residues. If the amount of the fluorine compound exceeds 2% by weight, The insulating film may be damaged.

(C)

The inorganic acid included in the metal film etchant composition of the present invention serves as a co-oxidant of the metal film, that is, the etching rate can be controlled according to the content of the inorganic acid.

In addition, it can react with copper ions in the etchant composition, thereby preventing an increase in copper ion and preventing a decrease in the etching rate.

The inorganic acid includes at least one selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid and perchloric acid.

The inorganic acid is contained in an amount of 1 to 10% by weight, preferably 1 to 5% by weight based on the total weight of the etching solution composition of the present invention.

If the amount of the inorganic acid is less than 1% by weight, the etching rate may decrease to cause etching profile defects and residues. When the amount of the inorganic acid is more than 10% by weight, cracks may develop in the overeating angle and the photoresist, The wiring may be short-circuited.

(D) Methyl tetrazole

The methyl tetrazole contained in the metal film etchant composition of the present invention plays a role of controlling the etching rate of the copper film particularly in the metal film.

In addition, unlike aminotetrazole, which combines with a chlorine compound to generate a precipitate, the methyltetrazole does not form a precipitate, and thus the above problem can be fundamentally blocked.

Since the precipitates are not generated, the storage stability of the etchant composition can be increased, and deterioration of the performance and defective rate can be prevented.

The methyltetrazole is contained in an amount of 0.1 to 5% by weight, preferably 0.3 to 3% by weight based on the total weight of the etchant composition of the present invention.

If the content of the methyltetrazole is less than 0.1 wt%, the etching rate of the copper film is increased and there is a risk of overeating. If the content of the methyltetrazole is more than 5 wt%, the etching rate of the copper film is lowered and the process time becomes excessively long.

(E) Chlorine compound

The chlorine compound contained in the metal film etchant composition of the present invention is a co-oxidizing agent particularly for etching a copper film among the metal films and serves to adjust the taper angle.

The chlorine compound means a compound capable of dissociating into chlorine ions, and preferably includes at least one selected from the group consisting of hydrochloric acid, sodium chloride, potassium chloride and ammonium chloride.

The chlorine compound is contained in an amount of 0.1 to 5% by weight, preferably 0.1 to 3% by weight based on the total weight of the etchant composition of the present invention.

If the content of the chlorine compound is less than 0.1 wt%, the etching rate of the copper film is lowered and the etching profile becomes poor. If the chlorine compound is contained in an amount exceeding 5 wt%, overcorrection may occur and metal wiring may be lost.

(F) Water

Water contained in the metal film etchant composition of the present invention is contained in a residual amount such that the total weight of the etchant composition is 100% by weight. The water is not particularly limited, but it is preferable to use deionized water.

(G) Copper salt

The metal film etchant composition of the present invention may further include a copper salt, and the copper salt serves to control CD skew.

The copper salt includes at least one selected from the group consisting of copper nitrate (Cu (No ₃ ) ₂ ), copper sulfate (CuSO ₄ ) and ammonium copper phosphate (NH ₄ CuPO ₄ ).

The copper salt is included in an amount of 0.05 to 3% by weight, preferably 0.05 to 1% by weight based on the total weight of the etchant composition of the present invention.

If the amount of the copper salt is less than 0.05% by weight, the deviation of the CD skew is greatly increased according to the number of treatments. If the copper salt content is more than 3% by weight, the oxidizing power of the main oxidizing agent is decreased.

(H) an organic acid or Organic acid salt

The metal film etchant composition of the present invention may further comprise an organic acid or an organic acid salt, and the organic acid or organic acid salt may prevent an etching composition from being affected by a chelating action with the etched metal ion, .

The organic acid may be selected from the group consisting of acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, sulfosuccinic acid, sulfophthalic acid, salicylic acid, sulfosalicylic acid, benzoic acid, lactic acid, And at least one selected from the group consisting of acetic acid, acetic acid, malic acid, tartaric acid, isocitric acid, propenoic acid, iminodiacetic acid and ethylenediaminetetraacetic acid.

In addition, the organic acid salt includes at least one selected from the group consisting of potassium salts, sodium salts and ammonium salts of the organic acid.

The organic acid or the organic acid salt is contained in an amount of 0.1 to 10% by weight, preferably 0.1 to 5% by weight based on the total weight of the etchant composition of the present invention.

If the content of the organic acid or the organic acid is less than 0.1% by weight, the effect of increasing the number of treatments is not exhibited. If the organic acid or the organic acid salt is contained more than 10% by weight,

In addition, the metal film etchant composition of the present invention may further include at least one selected from the group consisting of a sequestering agent and a corrosion inhibitor. In addition, the additives are not limited thereto, and various other additives known in the art may be selected and added for better effect of the present invention.

The components of the metal film etchant composition of the present invention can be prepared by a conventionally known method and are preferably used for purity for semiconductor processing.

The metal film etchant composition of the present invention can be performed by an etching method commonly known in the art. For example, a method using deposition, spraying, or immersion and spraying may be used, in which case the temperature as an etching condition is usually 30 to 80, preferably 50 to 70, and the deposition, spraying, Usually 30 seconds to 10 minutes, preferably 1 minute to 5 minutes. However, these conditions are not strictly applied and can be selected by those skilled in the art as being convenient or suitable.

The present invention also relates to a method of manufacturing a display device including a step of etching a metal film by the etching solution composition of the present invention.

The metal film is a multilayer film, and the multilayer film is preferably a multilayer film including a titanium film and a copper film.

The multi-layer film including the titanium film and the copper film means a multi-metal film in which a titanium film and a copper film are laminated. Specifically, it includes a double metal film in which a copper film / titanium film is stacked in this order, a titanium film / copper film, and a double metal film in this order. Also, a multi-metal film in which a copper film and a titanium film are alternately stacked in three or more layers such as a ternary metal film of a copper film / titanium film / copper film, a ternary metal film of a titanium film / copper film / titanium film, a copper film / A copper film / a titanium film / a copper film, and the like. At this time, the thickness of the copper film and the titanium film is not particularly limited.

In the present invention, the copper film may be a copper single film composed only of copper, and may be formed of aluminum, magnesium, manganese, beryllium, hafnium, And a copper alloy including at least one selected from the group consisting of tungsten (W) and vanadium (V).

In the present invention, the titanium film may be a single titanium film composed only of titanium, and aluminum, Al, Mg, Mn, beryllium, hafnium, niobium, And a titanium alloy film composed of a titanium alloy including at least one selected from the group consisting of tungsten (W) and vanadium (V).

Further, the display device may be a thin film transistor (TFT) array substrate.

The present invention also relates to a display device manufactured by the above manufacturing method.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

< Metal film Etchant  Composition Preparation>

Example  1 to 10 and Comparative Example  1 to 6.

The metal film etchant compositions of Examples 1 to 10 and Comparative Examples 1 to 6 were prepared according to the composition shown in Table 1 below.

(Unit: wt%) division SPS ABF HNO ₃ Tetrazole Taper angle adjusting agent CuSO ₄ AcOH water Kinds content Kinds content Example 1 10 0.5 3 MTZ 0.1 NaCl One - - Balance Example 2 10 0.5 3 MTZ 0.5 NaCl One - - Balance Example 3 10 0.5 3 MTZ One NaCl One - - Balance Example 4 10 0.5 3 MTZ 3 NaCl One - - Balance Example 5 10 0.5 3 MTZ 5 NaCl One - - Balance Example 6 10 0.5 3 MTZ 0.1 NaCl One 0.2 3 Balance Example 7 10 0.5 3 MTZ 0.5 NaCl One 0.2 3 Balance Example 8 10 0.5 3 MTZ One NaCl One 0.2 3 Balance Example 9 10 0.5 3 MTZ 3 NaCl One 0.2 3 Balance Example 10 10 0.5 3 MTZ 5 NaCl One 0.2 3 Balance Comparative Example 1 10 0.5 3 ATZ 0.5 NaCl One - - Balance Comparative Example 2 10 0.5 3 MTZ 0.5 NaBr One 0.2 3 Balance Comparative Example 3 10 0.5 3 ATZ 0.5 NaCl One 0.2 3 Balance Comparative Example 4 10 0.5 3 TZ 0.5 NaCl One 0.2 3 Balance Comparative Example 5 10 0.5 3 MTZ 0.5 NaNO ₃ One 0.2 3 Balance Comparative Example 6 10 0.5 3 ETZ 0.5 NaCl One 0.2 3 Balance

SPS: Sodium persulfate

ABF: Ammonium bifluoride

MTZ: Methyltetrazole

ATZ: 5-Aminotetrazole

TZ: Tetrazole

ETZ: Ethyltetrazole

AcOH: Acetic acid

Experimental Example  One. Metal film Etchant  Of the composition Etching  Characteristic and storage stability assessment

1-1. Etching  Character rating

The etching characteristics of the etching solutions according to Examples 1 to 10 and Comparative Examples 1 to 6 were evaluated as follows.

A SiNx layer is deposited on the glass, a titanium film is deposited on the SiNx layer, and a copper film is deposited on the titanium film. On the copper film, the substrate having the pattern of the photoresist patterned in a predetermined shape was cut into 550 × 650 mm using a diamond knife to prepare a specimen.

The etching composition compositions of Examples 1 to 10 and Comparative Examples 1 to 6 were put into an experimental apparatus of a spray-type etching system and the temperature was raised to 25 ° C. Thereafter, after the temperature reached 30 +/- 0.1 DEG C, the etching process was performed. Total etch time was 200% over etch based on EPD. When the etching was completed, the specimen was injected. After the etching was completed, the substrate was washed with deionized water, dried using an air gun, and photoresist was removed using a photoresist stripper. After washing and drying, etching characteristics (presence or absence of data open) were evaluated using an electron microscope, and the results are shown in Table 2 below.

1-2. Storage stability evaluation

Cu 3000 ppm powder was added to the etchant compositions of Examples 1 to 10 and Comparative Examples 1 to 6, and completely dissolved in a Stirrer for about 30 minutes. Then, it was put into a prepared P.E bottle and kept at a low temperature (-9 캜 or less) under severe conditions to observe whether or not precipitation occurred in real time, and the results are shown in Table 2 below.

division Data open Yes / No Occurrence of precipitation 1 day 7 days 15th Example 1 radish radish radish radish Example 2 radish radish radish radish Example 3 radish radish radish radish Example 4 radish radish radish radish Example 5 radish radish radish radish Example 6 radish radish radish radish Example 7 radish radish radish radish Example 8 radish radish radish radish Example 9 radish radish radish radish Example 10 radish radish radish radish Comparative Example 1 radish U U U Comparative Example 2 U radish radish radish Comparative Example 3 radish U U U Comparative Example 4 radish U U U Comparative Example 5 U radish radish radish Comparative Example 6 radish U U U

From the results of Table 2, it was confirmed that the data of the etchant compositions of Examples 1 to 10 of the present invention did not cause data open, and that storage stability was excellent due to no precipitate.

On the other hand, in the etchant compositions of Comparative Examples 1, 3, 4, and 6, the use of different tetrazoles instead of methyltetrazole did not cause data opening, but resulted in precipitation and poor storage stability.

Further, by using bromine and nitric acid compounds instead of a chlorine compound as the taper angle adjusting agent in the etching solution compositions of Comparative Examples 2 and 5, the storage stability was excellent, but data overexposure data was opened.

Therefore, the etching solution composition of the present invention is not over-cooked and does not generate precipitates, so that it is excellent in storage stability, thereby maintaining a clean process environment and increasing process efficiency.

Claims (12)

A metal film etchant composition comprising persulfate, fluorine compound, mineral acid, methyltetrazole, chlorine compound and water. The metal film etchant composition of claim 1, wherein the persulfate comprises at least one selected from the group consisting of potassium persulfate, sodium persulfate, and ammonium persulfate. The metal film etchant composition of claim 1, wherein the fluorine compound comprises at least one selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, sodium fluoride, and potassium fluoride. The metal film etchant composition of claim 1, wherein the inorganic acid comprises at least one selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, and perchloric acid. The metal film etchant composition according to claim 1, wherein the chlorine compound comprises at least one selected from the group consisting of hydrochloric acid, sodium chloride, potassium chloride, and ammonium chloride. The etching composition according to claim 1, wherein 0.5 to 20% by weight of persulfate, 0.01 to 2% by weight of fluorine compound, 1 to 10% by weight of inorganic acid, 0.1 to 5% by weight of methyltetrazole and 0.1 to 5% %, And the remaining amount of water is such that the total weight of the etchant composition is 100% by weight. The metal film etchant composition of claim 1, wherein the etchant composition further comprises at least one selected from the group consisting of an organic acid or an organic acid salt, and a copper salt. [Claim 7] The method of claim 7, wherein the organic acid is selected from the group consisting of acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, sulfosuccinic acid, sulfophthalic acid, salicylic acid, sulfosalicylic acid, At least one member selected from the group consisting of glyceric acid, succinic acid, malic acid, tartaric acid, isocitric acid, propenoic acid, iminodiacetic acid and ethylenediaminetetraacetic acid,
Wherein the organic acid salt comprises at least one selected from the group consisting of potassium salts, sodium salts and ammonium salts of the organic acid. [Claim 7] The composition of claim 7, wherein the copper salt comprises at least one selected from the group consisting of copper nitrate, copper sulfate and ammonium copper phosphate. The metal film etchant composition according to claim 7, comprising 0.1 to 10% by weight of an organic acid or an organic acid salt and 0.05 to 3% by weight of a copper salt based on the total weight of the etchant composition. The method according to claim 1, wherein the metal film is a multilayer film,
Wherein the multilayer film is a multilayer film including a titanium film and a copper film. A method of manufacturing a display device comprising a step of etching a metal film by the etching liquid composition of any one of claims 1 to 11.