TWI662156B - Etching solution composition for metal layer and manufacturing method of an array substrate for liquid crystal display using the same - Google Patents

Abstract

The invention discloses an etchant composition, comprising: a metal layer oxidant; a fluoride; a nitrogen atom-containing compound; phosphoric acid; polyethylene glycol; and a remaining amount of water, wherein, relative to 1 g of the above-mentioned etchant composition, The millimolar amount of the repeating unit of polyethylene glycol is used to indicate the ethylene oxide level, and the ethylene oxide level of the etchant composition is 0.4 to 2; and a method for manufacturing a liquid crystal display using the composition is disclosed. Array substrate method.

Description

Etching liquid composition and method for manufacturing array substrate for liquid crystal display using the same

The present invention relates to an etchant composition for a metal layer and a method for manufacturing an array substrate for a liquid crystal display using the etchant composition.

As flat-panel display screens such as LCDs, PDPs, and OLEDs, and especially TFT-LCDs have become larger, the use of single layers made of copper or copper alloys, or copper or copper alloys / other metals, alloys of other metals, or Multiple layers of metal oxides greater than two to reduce wiring resistance and improve adhesion to the dielectric silicon layer. For example, a copper / molybdenum layer, a copper / titanium layer, or a copper / molybdenum-titanium layer can be formed as a gate line and a source / drain line constituting a data line of a TFT-LCD, and can help expand a display screen. Therefore, there is a need to develop a composition having excellent etching characteristics for etching these metal layers including a copper-based layer.

As the above-mentioned etching composition, hydrogen peroxide and amino acid-based etching solutions, hydrogen peroxide and phosphoric acid-based etching solutions, hydrogen peroxide and polyethylene glycol-based etching solutions, and the like are generally used.

As an example, Korean Patent Application Publication No. 10-2011-0031796 discloses an etching solution including a water-soluble compound having: A) hydrogen peroxide (H ₂ O ₂ ), B) persulfate, and C) having an amine group and Soluble compounds of carboxyl group as well as water.

Korean Patent Application Publication No. 10-2012-0044630 discloses an etching solution for a copper-containing metal layer, including: hydrogen peroxide, phosphoric acid, a cyclic amine compound, sulfate, fluoboric acid, and water.

Korean Patent Application Publication No. 10-2012-0081764 discloses an etching solution including: A) ammonium hydroxide, B) hydrogen peroxide, C) fluoride, D) polyol, and E) water.

However, for the copper-containing metal layer, in terms of CD loss, slope (taper), pattern straightness, metal residue, storage stability, number of sheets processed, etc., the above-mentioned etchant is not sufficient to meet the relevant Conditions required in the field.

(Prior technical literature) (Patent Literature)

Patent Document 1: Korean Patent Application Publication No. 10-2011-0031796.

Patent Document 2: Korean Patent Application Publication No. 10-2012-0044630.

Patent Document 3: Korean Patent Application Publication No. 10-2012-0081764.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide an etching solution composition having excellent work safety, excellent etching rate, and excellent processing ability for a large number of sheets, and in particular, to provide an etching solution Composition which has excellent etch rate The material has excellent processing ability while having an optimal etching profile; and a method for manufacturing an array substrate for a liquid crystal display using the composition.

To achieve the above object, one aspect of the present invention provides an etching solution composition including: a metal layer oxidant; a fluoride; a nitrogen atom-containing compound; phosphoric acid; polyethylene glycol of the following Chemical Formula 1; and a remaining amount of water, Here, the millimolar amount of the repeating unit of polyethylene glycol of the following Chemical Formula 1 with respect to 1 g of the aforementioned etching solution composition is used to indicate the ethylene oxide level, and the ethylene oxide level of the aforementioned etching solution composition is It is 0.4 ~ 2.

Wherein n is an integer of 2 to 100, and R ₁ and R ₂ are each independently hydrogen, an aliphatic hydrocarbon group of C1 to C4, or a phenyl group.

Another aspect of the present invention provides a method of manufacturing an array substrate for a liquid crystal display, including: a) a step of forming a gate electrode on a substrate; b) a step of forming a gate insulator on the aforementioned substrate including the aforementioned gate; c ) A step of forming a semiconductor layer on the aforementioned gate insulator; d) a step of forming a source / drain on the aforementioned semiconductor layer; and e) a step of forming a pixel electrode connected to the aforementioned drain; wherein steps a), d ) Or e) includes the steps of forming a metal layer and etching the aforementioned metal layer using the etchant composition according to the present invention to form an electrode.

The metal layer etchant composition of the present invention can increase the number of sheets processed by adjusting the repeating unit.

In addition, the metal layer etchant composition of the present invention provides an excellent etching rate.

Further, the etchant composition for a metal layer containing a copper-based layer contains, for example, a low content of hydrogen peroxide, so it has the advantages of excellent work safety, price competitiveness, and the ability to dispose of the etchant economically.

Further, the method for manufacturing an array substrate for a liquid crystal display using the etchant composition in the present invention enables a liquid crystal display having excellent driving characteristics to be manufactured by forming an electrode having an excellent etching profile on an array substrate for a liquid crystal display. Use an array substrate.

The present invention is described in detail below.

The invention relates to an etching solution composition, comprising: a metal layer oxidant; a fluoride; a compound containing a nitrogen atom; a phosphoric acid; a polyethylene glycol of the following chemical formula 1; The millimolar amount of the repeating unit of polyethylene glycol of the following chemical formula 1 of the composition is used to indicate the ethylene oxide level, and the ethylene oxide level of the above-mentioned etching solution composition is 0.4 to 2.

Wherein n is an integer of 2 to 100, and R ₁ and R ₂ are each independently hydrogen, an aliphatic hydrocarbon group of C1 to C4, or a phenyl group.

More preferably, R ₁ and R ₂ are each independently hydrogen or methyl.

The present invention can provide an etching solution composition having an ethylene oxide level of 0.4 to 2 by adjusting the repeating unit of Chemical Formula 1, thereby improving the etching rate and the number of sheets processed, and finally can provide an Metal layer etching solution composition.

In the present invention, the ethylene oxide level is preferably 0.4 to 2, and more preferably 0.8 to 1.5. If the ethylene oxide level is less than 0.4, the improvement in the number of sheets processed is insufficient, and if it exceeds 2, there is a problem that the etching rate decreases due to an increase in viscosity.

The metal layer oxidant is a main component for oxidizing the metal layer. It is not particularly limited, but may be selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxide, nitric acid, persulfate, hydrohalic acid, and halide. One or more of the group.

The oxidized metal refers to a metal that is oxidized, such as Fe ³⁺ , Cu ²⁺ , and the like, and it includes compounds that dissociate into Fe ³⁺ , Cu ²⁺ , and the like in a solution state. Persulfate salts include ammonium persulfate, alkali metal persulfate, oxone, and the like, and halates include chlorate, perchlorate, bromate, perbromate, and the like.

The metal layer etchant composition can be prepared by including the following composition components: 1% to 40% by weight of the metal layer oxidant relative to the total weight of the composition; 0.1% to 5% by weight of fluoride; 0.1% to 10% by weight Nitrogen atom-containing compound; 0.01% to 10% by weight of phosphoric acid; polyethylene glycol of Chemical Formula 1 The amount of wt% makes the aforementioned ethylene oxide level 0.4 to 2; and the remaining amount of water.

The content of the metal layer oxidant may be appropriately controlled according to the type and nature of the oxidant, and when the amount of the metal layer oxidant falls within the above range, the etching rate of the metal layer may be appropriately adjusted.

The polyethylene glycol of Chemical Formula 1 of the present invention is an addition polymer of ethylene oxide, and its repeating unit is ethylene oxide. The weight% amount of the polyethylene glycol of the chemical formula 1 is 0.4 to 2 and preferably 0.8 to 1.5 with respect to the total weight of the composition. Therefore, by adjusting the repeating unit of Chemical Formula 1, it is possible to prepare a metal layer etchant composition in which the number of processed sheets is increased without reducing the etching rate.

The fluoride contained in the etching solution composition of the present invention is used to remove etching residues, and is used to etch a titanium-based metal layer.

Relative to the total weight of the composition, the amount of fluoride may be 0.1 wt% to 5 wt%, preferably 0.1 wt% to 2 wt%.

The above range is preferred because the etching residue is prevented and the glass substrate or the underlying silicon layer is not etched.

However, if the amount of fluoride exceeds the above range, stains are generated in the substrate due to uneven etching characteristics, the lower layer may be damaged due to an excessively fast etching rate, and it is difficult to control the etching rate during processing.

Preferably, the fluoride may be a compound capable of dissociating into a fluoride ion or a polyatomic fluorine ion.

The compound capable of dissociating into a fluoride ion or a polyatomic fluoride ion may be one or more selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium hydride, and potassium hydride.

The nitrogen atom-containing compound contained in the etching solution composition of the present invention is used to increase the etching rate of the etching solution and the number of sheets processed.

A nitrogen atom-containing compound known in the art may be used without limitation, and a compound containing an amine group and a carboxylic acid group in a molecule may be typically used.

The compound containing an amine group and a carboxylic acid group in the molecule may include, for example, an α-amino acid containing one carbon atom between the carboxylic acid group and the amine group, and is typically: a monovalent amino acid such as glycine Acids, glutamine, glutamine, isoleucine, proline, tyrosine, arginine, etc .; and polyvalent amino acids, such as iminodiacetic acid, nitrilotriacetic acid, ethyl Glycol tetraacetic acid. The nitrogen atom-containing compound may be used alone or in a combination of two or more.

The amount of the nitrogen atom-containing compound relative to the total weight of the composition is 0.1 wt% to 10 wt%, preferably 1 wt% to 5 wt%. The above preferable range is because the etching rate of the etchant and the number of sheets processed can be improved.

Phosphoric acid promotes the etching of copper by the metal layer oxidant by supplying hydrogen ions to the etchant. In addition, by combining with the oxidized copper ions to form phosphate, the solubility in water is increased, and the residue of the metal layer after the etching is eliminated.

The amount of phosphoric acid is 0.01 wt% to 10 wt%, and preferably 0.01 wt% to 1 wt% with respect to the total weight of the composition. When the amount of phosphoric acid satisfies the above range, an expected function can be performed because the risk of excessively etching the metal layer and corroding the underlying layer caused by the phosphoric acid can be avoided, and the etching rate of the copper metal layer does not change due to the too low content of phosphoric acid Low problem.

The water used in the present invention refers to deionized water. Water, and preferably more than 18 MΩ / cm.

In addition to the above-mentioned constituents, the etchant composition of the present invention may further include at least one selected from an etching control agent, a surfactant, a chelating agent, a corrosion inhibitor, and a pH adjuster.

The metal layer etched with the etchant composition of the present invention is not particularly limited, but the etchant composition of the present invention can be preferably used to etch a copper-based metal layer, a molybdenum-based metal layer, a titanium-based metal layer, or consist of these layers. Plural layers.

The copper-based metal layer refers to a copper layer or a copper alloy layer, the molybdenum-based metal layer refers to a molybdenum layer or a molybdenum alloy layer, and the titanium-based metal layer refers to a titanium layer or a titanium alloy layer.

The plurality of layers include, for example, a double layer of a molybdenum-based metal layer / a copper-based metal layer, wherein the copper-based metal layer is a lower layer and a molybdenum-based metal layer is an upper layer; a double layer of a copper-based metal layer / molybdenum-based metal layer, wherein, The molybdenum metal layer is a lower layer and the copper-based metal layer is an upper layer; a copper-based metal layer / a double layer of a molybdenum-based and a titanium-based metal layer; and a plurality of layers having more than three layers, wherein the copper-based metal layer and the molybdenum-based metal layer are alternately laminated For example, a molybdenum-based metal layer / copper-based metal layer / molybdenum-based metal layer, or a copper-based metal layer / molybdenum-based metal layer / copper-based metal layer.

In addition, the plural layers include, for example, a double layer of a titanium-based metal layer / a copper-based metal layer, wherein the copper metal layer is a lower layer and a titanium-based metal layer is an upper layer; a double layer of a copper-based metal layer / titanium-based metal layer, wherein The titanium metal layer is a lower layer and the copper-based metal layer is an upper layer; and a plurality of layers of more than three layers, wherein the copper-based metal layer and the titanium-based metal layer are alternately laminated, for example, a titanium-based metal layer / a copper-based metal layer / a titanium-based metal Layer, or copper-based metal layer / titanium-based metal layer / copper-based metal layer.

By considering the materials constituting the upper layer or the lower layer or the adhesion to the layers, etc., the interlayer combination structure of a plurality of layers can be determined.

The copper alloy layer, the molybdenum alloy layer, or the titanium alloy layer refers to a metal layer produced as an alloy. In the alloy, copper, molybdenum, or titanium is a main component and other different metals are used depending on the properties of the film. For example, the molybdenum alloy layer refers to molybdenum as a main component and contains one or more selected from titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), neodymium (Nd), and indium (In). A layer produced by a plurality of alloys.

As a specific embodiment of the etching solution composition of the present invention, hydrogen peroxide may be used as a metal layer oxidant, and may include fluoride, a nitrogen atom-containing compound, phosphoric acid, polyethylene glycol of Chemical Formula 1, and a remaining amount of water.

Hydrogen peroxide is the main component for oxidizing copper, molybdenum, and titanium, and its amount may be 1 wt% to 25 wt%, preferably greater than 1 wt% and less than or equal to 10 wt%, relative to the total weight of the composition. It is preferably more than 1 wt% and less than or equal to 5 wt%.

When the amount of hydrogen peroxide falls within the above range, the deterioration of the etching rates of copper, molybdenum, and titanium is prevented, an appropriate amount of etching can be achieved, and an excellent etching profile can be obtained.

However, if the amount of hydrogen peroxide is out of the above range, etching will not occur or excessive etching will occur, so pattern loss and loss of function as a metal wiring may occur.

It is preferable that the component which comprises the etching solution composition of this invention has purity for semiconductor processing.

Further, the present invention relates to a method for manufacturing an array substrate for a liquid crystal display, including: a) a step of forming a gate electrode on the substrate; b) a step of forming a gate insulator on a substrate including a gate electrode; c) a step of forming a semiconductor layer on the gate insulator; d) a step of forming a source / drain electrode on the semiconductor layer; and e) forming a connection to the drain electrode A step of a pixel electrode; wherein step a), d) or e) includes a step of forming a metal layer and etching the metal layer using the etchant composition according to the present invention to form an electrode.

The array substrate for a liquid crystal display produced by the above method has excellent driving characteristics because it includes an electrode having an excellent etching profile.

The array substrate for a liquid crystal display may be a thin film transistor (TFT) array substrate.

The invention is described in more detail below by means of the embodiments provided. However, the following examples are used to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples. The following embodiments can be appropriately modified by those having ordinary skill in the art within the scope of the present invention.

(Example)

<Preparation of Etching Liquid Composition>

Examples 1 to 6 and Comparative Examples 1 to 6:

An etching solution composition was prepared by mixing the constituents at the contents described in Table 1 below.

[Chemical Formula 5]

Experimental Example 1: Evaluation of etching profile of etching solution composition for Cu / Mo-Ti double layer

Cu / Mo-Ti double-layer etching was performed using the etching solution compositions of Examples 1 to 6 and Comparative Examples 1 to 6. When the etching is performed, etching is performed for 100 seconds using an etchant composition having a temperature of about 30 ° C. The EPD (End Point Detection, Metal Etching Timing) was measured by the naked eye to obtain an etching rate according to time. The profile section of the etched Cu / Mo-Ti double layer was examined using a SEM (Hitachi, Model S4700), and the results are shown in Table 2 below.

Experimental example 2: Evaluation of the number of sheets processed

Reference tests were performed using the etchant compositions of Examples 1 to 6 and Comparative Examples 1 to 6, and 4000 ppm of copper powder was added to the etchant used for the reference test and completely dissolved. After that, the etching was performed again using the etching solution that was subjected to the reference test, and the reduction rate of the etching rate was evaluated.

<Evaluation criteria>

○: Excellent (less than 10% reduction in etching rate)

△: Good (reduction rate of etching rate is 10% to 20%)

×: Poor (reduction rate of etching rate is greater than 20%)

Claims (5)

An etchant composition comprising: hydrogen peroxide; a fluoride; a compound containing a nitrogen atom; phosphoric acid; polyethylene glycol of the following chemical formula 1; and a remaining amount of water relative to the total weight of the aforementioned etchant composition Including: 1 wt% to 25 wt% of the aforementioned hydrogen peroxide; 0.1 wt% to 5 wt% of the aforementioned fluoride; 0.1 wt% to 10 wt% of the aforementioned nitrogen atom-containing compound; 0.01 wt% to 10 wt% of the aforementioned phosphoric acid; The wt% amount of the polyethylene glycol of Chemical Formula 1 is such that the foregoing ethylene oxide level is 0.4 to 2; and the remaining amount of water relative to 1 g of the polyethylene glycol of the following Chemical Formula 1 of the aforementioned etching solution composition The millimolar amount of the repeating unit is used to indicate the ethylene oxide level, and the ethylene oxide level of the aforementioned etching solution composition is 0.4 to 2; wherein the aforementioned nitrogen atom-containing compound is an amino acid; Wherein n is an integer of 2 to 100, and R ₁ and R ₂ are each independently hydrogen, an aliphatic hydrocarbon group of C1 to C4, or a phenyl group. The etching solution composition according to claim 1, wherein R ₁ and R ₂ are each independently hydrogen or methyl. The etching solution composition according to claim 1, wherein the etching solution composition is used to etch a copper-based metal layer, a molybdenum-based metal layer, a titanium-based metal layer, or a plurality of these layers. The etching solution composition according to claim 3, wherein the plurality of layers are a copper-based metal layer / molybdenum metal layer, a copper-based metal layer / titanium-based metal layer, or a copper-based metal layer / molybdenum-titanium alloy layer. A method of manufacturing an array substrate for a liquid crystal display, comprising: a) a step of forming a gate electrode on a substrate; b) a step of forming a gate insulator on the aforementioned substrate including the gate electrode; c) forming on the aforementioned gate insulator A step of forming a semiconductor layer; d) a step of forming a source / drain on the aforementioned semiconductor layer; and e) a step of forming a pixel electrode connected to the aforementioned drain; wherein step a), d) or e) includes forming a metal And forming the electrode by etching the aforementioned metal layer using the etchant composition as described in any one of claims 1 to 4.