TWI662155B - Etching solution composition for metal layer and manufacturing method of an array substrate for liquid crystal display using the same - Google Patents

Abstract

Disclosed herein is an etching solution composition comprising: a metal layer oxidant, a fluorine compound, phosphoric acid, a diol, and a balance of water, wherein the etching rate of the etching solution composition when the number of sheets to be processed is 5000 A ratio of an etching rate when the number of processed sheets is 100 is 0.9 to 1; and a method for manufacturing an array substrate for a liquid crystal display using the composition.

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 composition.

As screens for flat panel displays such as LCDs, PDPs, and OLEDs, especially TFT-LCDs become larger, the use of copper or copper alloys as a single layer, or copper or copper alloys / other metals, alloys of other metals, or Multiple layers of metal oxides larger than two layers in order 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 may be formed as a gate line and a source / drain line constituting a data line of a TFT-LCD, and may 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 containing a water-soluble compound having: A) a peroxide (H ₂ O ₂ ), B) a persulfate, and C) an amine group and Carboxyl soluble compounds and water.

Korean Patent Application Publication No. 10-2012-0044630 discloses an etching solution for a metal layer containing copper, 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) a fluorine compound, D) a polyol, and E) water.

However, in terms of CD loss, slope (taper), pattern straightness, metal residue, storage stability, number of sheets to be treated, etc. of the metal layer including the copper-based layer, the above-mentioned etchant cannot fully satisfy Conditions required in the relevant 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 designed to solve the above-mentioned problems, and an object of the present invention is to provide an etchant composition for a metal layer having excellent working safety, excellent etching rate, and ability to process a large number of substrates, and specifically having optimal etching Characteristics without etch rate degradation due to increasing number of processes An etching solution composition; and a method for manufacturing an array substrate for a liquid crystal display using the composition.

In order to achieve the above object, an aspect of the present invention provides an etching solution composition, including: a metal layer oxidant, a fluorine compound, phosphoric acid, a diol, and a balance of water, characterized in that when the number of sheets to be processed is 5000 The ratio of the etching rate to the etching rate when the number of sheets to be treated is 100 is 0.9 to 1.

Another aspect of the present invention provides a method for 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 a substrate including the foregoing gate electrode; 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 source / drain; wherein, the aforementioned steps a), d ) Or e) includes the steps of forming a metal layer and etching the aforementioned metal layer with the etchant composition according to the present invention to form an electrode.

Since the etching rate hardly decreases as the number of sheets to be processed increases, the etchant composition for a metal layer of the present invention can provide an excellent number of sheets to be processed.

Further, as an embodiment of the present invention, for example, an etchant composition for a metal layer including a copper-based layer contains a low content of hydrogen peroxide, and thus has excellent work safety, price competitiveness, and can dispose of the etchant economically. Effect.

Further, the method for manufacturing an array substrate for a liquid crystal display using the etching solution composition in the present invention can be applied to an array substrate for a liquid crystal display. An electrode having an excellent etching profile is formed thereon to manufacture an array substrate for a liquid crystal display having excellent driving characteristics.

The detailed description of the present invention is disclosed below.

The invention relates to an etching solution composition, comprising: a metal layer oxidant, a fluorine compound, phosphoric acid, a diol, and a balance of water. The etching solution composition is etched when the number of sheets to be processed is 5000. The ratio of the rate to the etching rate when the number of sheets to be processed is 100 is 0.9 to 1.

In the present invention, the ratio of the etching rate of the etchant composition when the number of sheets to be processed is 5,000 to the etching rate when the number of sheets to be processed is 100 is defined as the etching durability.

When using the etchant composition to etch a metal layer, there is a typical problem that the etching rate decreases as the number of sheets to be processed increases, so that a large number of metal layers cannot be etched.

However, the etching solution composition of the present invention has the advantage that more metal layers can be etched because the etching rate hardly decreases with an increase in the number of sheets to be treated due to excellent etching durability.

The above etching rate refers to a value obtained by dividing a thickness of a metal by a time (thickness / hour of the metal, μm / s), where the time is a time measured for completely etching a metal layer having a predetermined thickness.

The etching durability of the etching solution composition of the present invention cannot be greater than 1 and is in the range of less than 0.9, because the etching rate is the same under the same step conditions Differences in rate may cause problems such as etch residue and taper changes.

The metal layer oxidant is a main component for oxidizing the metal layer and is not particularly limited, but may typically include a material selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxides, nitric acid, persulfates, hydrohalic acids, and hydrohalates And so on.

The metal oxide refers to a metal that is oxidized, for example, Fe ³⁺ , Cu ²⁺ and the like, and includes compounds that dissociate into Fe ³⁺ , Cu ²⁺ and the like in a solution state.

Persulfates include ammonium persulfate, alkali metal persulfate, oxone persulfate, and the like, and hydrohalates include chlorate, perchlorate, bromate, perbromate, etc. .

With respect to the total weight of the composition, the etchant composition can be prepared to contain 1% to 40% by weight of a metal layer oxidant, 0.1% to 5% by weight of a fluorine compound, 0.01% to 10% by weight of phosphoric acid, 0.1 to 10% by weight of diol and the balance of water.

The content of the oxidant of the metal layer can be appropriately adjusted according to the type and characteristics of the oxidant, and if it is included in the above range, the etching rate of the metal layer can be appropriately adjusted.

The content of the fluorine compound may be 0.1% to 5% by weight, and preferably 0.1% to 2% by weight, relative to the total weight of the composition.

The above range is preferable because it prevents etching residues and does not cause etching of the glass substrate or the lower silicon layer.

However, if the above range is exceeded, stains are generated in the substrate due to uneven etching characteristics, an excessive etching rate may damage the lower layer, and etching rate control may become difficult during the step.

Preferably, the fluorine compound 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 at least one or plural kinds selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium hydrogen fluoride, and potassium hydride.

The content of phosphoric acid is 0.01 to 10% by weight, and preferably 0.01 to 1% by weight, with respect to the total weight of the composition. The expected function can be performed when the amount of phosphoric acid satisfies the above range, because the risk of over-etching and underlying corrosion of the metal layer caused by phosphoric acid can be avoided, and the etching rate of the copper metal layer does not cause a problem due to the too small content of phosphoric acid. .

As the diol, components known in the art can be used without any limitation, and polyethylene glycol is preferably used.

As the polyethylene glycol, an addition polymer of ethylene oxide having a hydroxyl group or an ether group at a terminal can be used, preferably having at least one hydroxyl group, and preferably having a molecular weight of 1,000 or less in order to suppress an excessive increase in solution viscosity.

The content of the diol is from 0.1 to 10% by weight, preferably from 1 to 5% by weight, with respect to the total weight of the composition.

If the content of the diol is less than 0.1% by weight, it is difficult to expect to increase the number of sheets to be processed for the substrate, and there may be a problem that the etching uniformity is lowered. Further, when it exceeds 10% by weight, a disadvantage of generating a large amount of foam may be caused.

The etching solution 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 a plurality of layers composed of these.

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

The plural layers include, for example, a double layer of a molybdenum-based metal layer / a copper-based metal layer, the copper-based metal layer is a lower layer and the molybdenum-based metal layer is an upper layer; the copper-based metal layer / molybdenum-based metal layer is a double layer, and 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 alloy layer; and a plurality of layers having more than three layers, the copper-based metal layer and the molybdenum-based metal layer are laminated on each other, for example, a molybdenum-based metal layer / Copper-based metal layer / molybdenum-based metal layer or 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, the copper metal layer is a lower layer and the titanium-based metal layer is an upper layer; the double layer of the copper-based metal layer / titanium-based metal layer, the titanium metal layer is A lower layer and a copper-based metal layer being an upper layer; a double layer of a copper-based metal layer / a titanium-based metal layer and a molybdenum-based alloy layer; and a plurality of layers having more than three layers, the copper-based metal layer and the titanium-based metal layer being laminated on each other, for example, a titanium-based layer Metal layer / copper-based metal layer / titanium-based metal layer or copper-based metal layer / titanium-based metal layer / copper-based metal layer.

Multiple considerations of the materials that make up the upper or lower layers, or the adhesion to the layers, etc., can determine the interlayer combination structure of multiple layers.

The copper, molybdenum or titanium alloy layer refers to a metal layer produced by using copper, molybdenum or titanium as a main component and using an alloy of other different metals according to 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). This alloy is produced in layers.

The etching solution composition of the present invention may additionally include a nitrogen atom-containing compound.

The nitrogen atom-containing compound contained in the etchant composition of the present invention functions to enhance the etching rate of the etchant composition and the number of sheets to be treated.

As the nitrogen atom-containing compound, a nitrogen atom-containing compound known in the art can be used without limitation, and a compound containing an amine group and a carboxylic acid group in a molecule can 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 and the amine group, and is typically: a monovalent amino acid such as glycine , Glutamine, glutamine, isoleucine, proline, tyrosine, arginine, etc .; and polyvalent amino acids, such as iminodiacetic acid, nitrilotriacetic acid, ethylenediamine Alcohol tetraacetic acid.

The nitrogen atom-containing compound may be used alone or in a combination of two or more.

The content of the nitrogen atom-containing compound with respect to the total weight of the composition is from 0.1% to 10% by weight, and preferably from 1% to 5% by weight.

If the nitrogen atom-containing compound is included in the above range, the etching rate of the etchant and the number of sheets to be processed can be increased.

The water used in the present invention refers to deionized water, water using a semiconductor step, and it is preferable to use water larger than 18 MΩ / cm.

In addition to the ingredients mentioned above, the etchant composition of the present invention may further include one or more selected from the group consisting of an etching control agent, a surfactant, a metal ion chelator, a corrosion inhibitor, and a pH adjuster.

As an embodiment of the present invention, hydrogen peroxide may be used as the metal layer oxidant, and in addition to fluorine compounds, phosphoric acid, glycols, and the balance of water, Compounds containing nitrogen atoms may be additionally included.

Specifically, the etchant composition is preferably used for etching a copper-based metal layer / molybdenum metal layer or a copper-based metal layer / titanium-based metal layer. However, the application of the composition is not limited to double layers.

Hydrogen peroxide is the main component of copper oxide, molybdenum, and titanium, and its content may be 1% to 25% by weight, preferably 1% to 10% by weight, and more relative to the total weight of the composition. It is preferably 1% to 5% by weight.

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 it is out of the above range, etching or excessive etching does not occur, and thus pattern loss and loss of function as a metal wiring may occur.

The components constituting the etchant composition of the present invention preferably have purity for semiconductor steps.

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 a substrate; b) a step of forming a gate insulator on a substrate including the gate electrode; c) A step of forming a semiconductor layer on an insulator; d) a step of forming a source / drain on the semiconductor layer; and e) a step of forming a pixel electrode connected to the source / drain; wherein step a), d) or e) includes The step of forming a metal layer and etching the metal layer with the aforementioned 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 according to the inclusion of an electrode having an excellent etch profile.

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

The present invention is explained in more detail below by the following examples, which are presented for explanation but are not to be construed as limiting the present invention. The scope of the present invention has been disclosed in the scope of the patent application, and in addition, it contains the meaning equivalent to the description of the scope of the patent application and all modifications within the scope.

(Example) <Manufacturing of Etching Solution Composition and Measurement of Etching Durability of Etching Solution Composition> (Examples 1-6 and Comparative Examples 1-3)

An etching solution composition was prepared by mixing the ingredients described in Table 1 below at a prescribed content (% by weight).

Then, the etching durability was observed after the Cu single layer was etched with the composition.

The etching of the Cu single layer was performed using the etchant compositions of Examples 1 to 6 and Comparative Examples 1 to 3 of Table 1.

The temperature of the etchant composition at the time of performing the etching was about 30 ° C, and the etching was performed for 100 seconds.

The etch durability is measured by measuring EPD (end point detection, timing of metal etching) with the naked eye when the number of processes is 100 and 5000, and obtaining the etching rate according to time, that is, the etchant composition on the wafer to be etched The ratio of the etching rate when the number of sheets is 5000 sheets to the etching rate when the number of sheets to be etched is 100 sheets.

[Table 1]

Claims (8)

An etching solution composition comprising: a metal layer oxidant, a fluorine compound, phosphoric acid, and a glycol; an amino acid and a balance of water; wherein the etching rate of the aforementioned etching solution composition when the number of sheets to be processed is 5000 The ratio to the etching rate when the number of sheets to be processed is 100 is 0.9 to 1. The etching solution composition according to claim 1, wherein the metal layer oxidant is selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxides, nitric acid, persulfates, hydrohalic acids, and hydrohalates. One or more. The etching solution composition according to claim 1, wherein the etching solution composition includes: 1% to 40% by weight of the foregoing metal layer oxidizer; 0.1% to 5% by weight of the foregoing fluorine compound; relative to the total weight of the foregoing composition; 0.01 The foregoing phosphoric acid in an amount of 10 to 10% by weight; the foregoing diol in an amount of 0.1 to 10% by weight; the foregoing amino acid in an amount of 0.1 to 10% by weight; and the balance of water. The etching solution composition according to claim 3, which contains hydrogen peroxide as the metal layer oxidant. The etching solution composition according to claim 4, wherein the composition contains 1 to 25% by weight of the hydrogen peroxide as the metal layer oxidizer with respect to the total weight of the composition. 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 6, wherein the plurality of layers are a copper-based metal layer / molybdenum-based metal layer, a copper-based metal layer / titanium-based metal layer, or a copper-based metal layer / molybdenum-titanium alloy layer. A method for manufacturing an array substrate for a liquid crystal display includes: a) a step of forming a gate electrode on a substrate; b) a step of forming a gate insulator on a substrate including the gate electrode; c) forming a semiconductor layer on the gate insulator Step; 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 source / drain; wherein the aforementioned step a), d) or e) includes forming a metal layer and The step of forming the electrode by etching the metal layer with the etchant composition according to any one of claims 1 to 7.