KR20110113902A - Etchant for thin film transistor-liquid crystal display - Google Patents

Abstract

The present invention relates to a patterning of multiple films made of a copper film and another metal, which is a metal wiring material for a gate, a source, and a drain electrode, which constitute a thin film transistor (TFT) of a thin film transistor liquid crystal display device. It relates to a composition of the etchant for.
The present invention is 3-20% by weight of hydrogen peroxide, 0.1-5% by weight of sulfate, 0.001-2% by weight of fluorine compound, 0.1-5% by weight of chelating agent, 0.1-5% by weight of inorganic acid, 0.01-1% by weight of boron-based compound, additives An etch composition comprising water such that 0.1 to 5% by weight and total weight is 100% by weight can provide an etch rate, a suitable etch amount and an appropriate taper tilt angle suitable for the process. In addition, by increasing the stability aspect, which is a problem of the conventional fruit-based etchant is characterized in that the purchase capacity of the treatment increased.

Description

Etch Composition for Thin Film Transistor Liquid Crystal Display {ETCHANT FOR THIN FILM TRANSISTOR-LIQUID CRYSTAL DISPLAY}

The present invention relates to an etching composition of a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, a molybdenum alloy film or a multilayer film in which they are laminated.

According to an embodiment of the present invention, a photoresist is coated and exposed on a metal wiring material for a gate, a source, and a drain electrode constituting a thin film transistor (TFT) of a liquid crystal display, and then etched to obtain a desired pattern ( It is about the etchant to obtain a pattern).

The resistance of the metal film used at this time is a factor that causes the electrical signal delay of the thin film transistor liquid crystal display device and has a direct effect on the high resolution and the panel size. In recent years, copper (Cu) has been in the spotlight as a metal wiring material having a low resistance value and having no large environmental problems in order to reduce the electrical signal delay of a thin film transistor liquid crystal display device.

However, copper has a disadvantage of poor adhesion with glass and silicon films, and thus it is difficult to use copper as a single copper film. Accordingly, a multilayer film using copper as a main wiring metal film and excellent copper alloy, titanium, molybdenum or molybdenum alloy as a buffer metal film is used to compensate for the shortcomings of a single copper film. In order to etch such a multi-layer, the permeate-based etchant is mainly used, as disclosed in Patent Publication No. 10-2006-0099089. Since the permeate-etched solution is decomposed into water and oxygen very quickly by promoting decomposition of the fruit water when the metal ion is above a certain concentration, it is exothermic. There is a problem in terms of stability in the case of high content of fruit or high concentration of metal ions due to the rapid change in composition.

The present invention is capable of batch etching multiple layers consisting of a copper film and another metal film with a low hydrogen peroxide content, and has an etching composition having an etching speed, an appropriate etching amount, and an appropriate taper angle suitable for the process. We want to develop an etching solution with a higher purchase capacity.

The present invention relates to an etching composition of a multilayer film composed of a copper film and another metal film, wherein the multilayer film of the copper film and another metal is a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, or a molybdenum alloy. Refers to a film or multiple films in which they are laminated. In general, an etching solution using a high concentration of hydrogen peroxide is used when etching a copper film or a multi-layer. However, when using a high concentration of fruit water, if the transition metal is dissolved in the etching solution, hydrogen peroxide is rapidly decomposed, so stability problems may occur. .

The present invention relates to an etching composition comprising hydrogen peroxide, sulfates, fluorine compounds, chelating agents, inorganic acids, boron-based compounds, additives and water. More specifically, the present invention is 3-20% by weight of hydrogen peroxide, 0.1-5% by weight of sulfate, 0.001-2% by weight of fluorine compound, 0.1-5% by weight of chelating agent, 0.1-5% by weight of inorganic acid, 0.01-1% by weight of boron compound It relates to an etching composition comprising water so that the%, the additive 0.1 to 5% by weight and the total weight is 100% by weight.

The etching composition according to the present invention provides an appropriate etching rate, etching amount and taper tilt angle when mixed in the above composition and range.

In the present invention, the hydrogen peroxide serves to oxidize copper to form copper oxide (CuO ₂ ). If the content is less than 3% by weight, the effect is insignificant. If the content is more than 20% by weight, the etching rate is too fast to control, and the hydrogen peroxide content is high.

In particular, the present invention by using the hydrogen peroxide in the above content range, it is possible to batch etching of a multi-layer consisting of a copper film and another metal film, an etching having an etching speed, a suitable etching amount and a suitable taper angle suitable for the process The composition may provide an etching solution having a higher purchase yield than a conventional permeate etching solution.

Preferred examples of the sulfate according to the present invention include, but are not limited to, ammonium sulfate, ammonium persulfate, potassium sulfate, potassium persulfate, sodium sulfate, sodium persulfate, and the like. The sulfate replaces copper oxide produced by hydrogen peroxide with copper sulfate (CuSO ₄ ), wherein the compound is water soluble and can be dissolved in an etching composition. Sulfate may comprise 0.1 to 5% by weight relative to the total weight of the total composition, less than 0.1% by weight may not be a smooth etching when etched in a copper film, copper alloy film or a multilayer film they are laminated, When it exceeds 5% by weight, the activity of the fluorine ions contained in the fluorine compound may be increased to cause damage to the glass substrate.

In the present invention, the fluorine compound may be at least one selected from the group consisting of acidic ammonium fluoride, silicic acid fluoride, potassium hydrogen fluoride and hydrofluoric acid. The fluorine compound may include 0.001 to 2% by weight based on the total weight of the total composition, when the content of the fluorine compound exceeds 2% by weight, the glass substrate or silicon film may be excessively etched, and the content of the fluorine compound may be less than 0.001% by weight. When the etching rate is significantly reduced, residues and tails are generated, making it difficult to apply the post process. Accordingly, the fluorine compound is preferably included in a range in which the glass substrate or the silicon film is not etched.

In the present invention, the chelating agent is an organic chelating agent containing an amino group and a carboxyl group. The organic chelating agent is characterized by consisting of at least one of EDTA, Iminodiacetic Acid, Nitrilotriacetic acid (Nitrilotriacetic acid) and Diethylene Trinitrilo Pentaacetic Acid (DTPA). When the chelating agent increases the number of etching treatments of the metal wiring to be etched, copper ions or metal ions increase in the etching solution to prevent the etching ability from deteriorating. The chelating agent may include 0.1 to 5% by weight with respect to the total weight of the total composition, when exceeding 5% by weight leads to a threshold that no longer affects, and also has a poor solubility to precipitate It may have, if contained in less than 0.1% by weight does not prevent the phenomenon that the etching ability is lowered when the treatment proceeds. Therefore, the preferred composition range is 0.1 to 5% by weight is appropriate.

In the present invention, the inorganic acid may be used to adjust the etch rate (etching rate) of the etchant, and may be selected from one or more of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, perchloric acid, and the like. The inorganic acid may include 0.1 to 5% by weight based on the total weight of the total composition, and when the inorganic acid is less than 0.1% or more than 5% by weight, the etch rate may not be controlled. Etching is not uniform.

In the present invention, the boron-based compound serves to suppress damage to the glass substrate and may be selected from one or more of boric acid, boric acid salts, boron oxide and borazole. The boron-based compound may include 0.01 to 1% by weight based on the total weight of the total composition, when containing less than 0.01% by weight of the glass substrate damage is greater than 1% by weight of titanium, titanium alloy film, Since the etching rate of the molybdenum film, the molybdenum alloy film, or the multilayer film in which they are laminated is significantly lowered, it is preferable to control the content within the residue and tail.

The present invention may include an additive, without being particularly limited, various kinds are possible, and as the preferred example, an azole compound which may be used as an etching inhibitor of a copper film may be used. The azole compound may be added in an amount of 0.1 to 5% by weight based on the total weight of the total composition, and may be used for controlling the etching rate and etching amount of copper or copper alloy. Examples of the azole compound include 5-aminotetrazole, 1,2,3-benzotriazole, methylbenzotriazole, imidazole and the like. If the additive contains less than 0.1% by weight, the loss due to etching (CD, Critical Dimension) may be large, and if it contains more than 5% by weight, the etching rate of copper or copper alloy may only be slowed. But the taper inclination angle can be uneven. In the present invention, the remaining amount of the total composition may be mixed with deionized water, and may serve to dilute the etching composition.

When performing the etching process with the etching composition of the present invention, a loss due to the etching 1.0㎛ or less, there is a taper angle of inclination can be efficiently etched by more than 30 ^o.

The etching composition according to the present invention is a pattern of a copper film which is a main wiring material of a gate electrode and a source / drain which constitutes a thin film transistor liquid crystal display (TFT-LCD). It can be used for patterning.

The etching composition according to the present invention can uniformly etch a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, a molybdenum alloy film, or a multilayer film in which these layers are stacked, and by changing the content of hydrogen peroxide and additives, Increasing margins and restraining heat generation and rapid compositional changes to secure stability has the effect of improving the purchase capacity.

1 is a photograph of observing a profile of a titanium film / copper film after etching with an etching composition according to Example 1 of the present invention with an electron microscope.
FIG. 2 is a photograph illustrating observation of a tail and a residue with an electron microscope after PR is removed from a titanium film / copper film after etching using a PR (photoresist) stripper as an etching composition according to Example 1 of the present invention.
FIG. 3 is a photograph illustrating observing a profile of molybdenum alloy / copper film after etching with an etching composition according to Example 1 of the present invention. FIG.
FIG. 4 is a photograph illustrating observing the tail and the residue with an electron microscope after PR removal of the molybdenum alloy / copper film after etching using an PR (photoresist) stripper with an etching composition according to Example 1 of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below.

Example 1

10% by weight of hydrogen peroxide, 1% by weight of sulfate, 1% by weight of inorganic acid (using HNO3), 1% by weight of chelating agent (iminodiacetic acid), 0.2% by weight of fluorine compound (ammonium fluoride), boric acid (Boric acid) 0.1 An etching composition was prepared by mixing deionized water with a weight%, 0.5 weight% of an additive (5-aminotetrazole), and 100 weight%.

Components and contents of the etching composition are shown in Table 1 below.

[Examples 2 to 5]

Was carried out in the same manner as in Example 1, it was prepared by mixing in the ingredients and contents shown in Table 1.

[Comparative Examples 1 to 5]

Was carried out in the same manner as in Example 1, it was prepared by mixing in the ingredients and contents shown in Table 2.

[Test Example]

Etching process

Using the etching compositions of Examples 1 to 5 and Comparative Examples 1 to 5 prepared above, an etching process was performed on a multilayer film in which a copper film and a titanium film were laminated at a temperature of 30 ° C., respectively. Next, a method of manufacturing a liquid crystal display device using the etching solution according to the present invention for forming gate wirings, gate electrodes, data wirings, and source / drain electrodes will be described.

After depositing a first copper / titanium film on the substrate, a first photoresist pattern was formed on the first copper / titanium film by a photolithography process. Next, the first copper / titanium film was etched using the first photoresist pattern as a mask to form a gate line having one direction, a gate electrode protruding from the gate line, and then a gate insulating film was deposited on the entire surface of the substrate. . Thereafter, the semiconductor layer was deposited on the entire surface including the gate insulating layer and then patterned to form an active layer.

Next, after depositing a second copper / titanium film on the entire surface of the substrate, a second photoresist film pattern is formed on the second copper / titanium film by a photolithography process, and the second copper / titanium film is etched by the etching solution according to the present invention. Data lines defining pixel regions perpendicular to the gate lines to define pixel regions, source electrodes protruding from one side of the data lines, and drain electrodes spaced apart from the source electrodes by a predetermined distance are formed.

In the etching process, the physical properties of the glass substrate were exceeded by 100% from the end point detection (EPD, End Point Detect). At this time, the reason for the excess etching exceeding 100% is that the etching rate of the other metal film is relatively slow compared to the copper film so that the tail and the residue of the other metal film can be sufficiently removed.

Property evaluation

In Examples 1 to 4 and Comparative Examples 1 to 4 by the following method, the etching loss, the inclination angle and the stability were measured and the results are shown in Table 1 and Table 2. Etch loss (CD skew) is shown to be excellent when the 0.5㎛ ± 0.2㎛ or less, Taper angle is shown to be excellent when more than 30 degrees.

FIG. 1 is a photograph illustrating observing a profile by electron microscopy after etching a copper / titanium film with an etching composition according to Example 1 of the present invention.

[Etch Loss Measurement]

The profile of the multilayer film (copper / titanium film) in which the etched titanium film and the copper film are laminated by the etching method is observed using an electron microscope (SEM, Hitachi S-4700), and the photoresist ends and The distance of the tip of the copper film was measured and represented by the etching loss measurement.

[Inclination angle measurement]

The profile of the multilayer film (copper / titanium film) in which the etched titanium film and the copper film are laminated by the etching method is observed using an electron microscope (SEM, Hitachi S-4700), The value of the inclination angle was measured to indicate the inclination angle.

 [Tail measurement]

After removing the PR using the PR (photoresist) stripper on the multilayer film (copper / titanium film) on which the etched titanium film and the copper film are laminated by the etching method, the profile is electron microscope (SEM, Hitachi, Ltd.). S-4700) was used to measure the distance between the tip of the copper film and the tip of the titanium film is represented by the tail measurement.

[Stability Measurement]

In the stability evaluation, after preparing 5kg of the etching solution, the Cu powder was added so that the Cu ion content was 4000ppm in the etching solution, and after completely dissolving, the temperature change was measured for 48 hours.

As shown in Table 2, when the content of the hydrogen peroxide is out of the range of the present invention shows a sudden CD change rate and it can be seen that the problem occurred in terms of stability.

Claims (8)

Etch composition of copper peroxide, sulfate, fluorine compound, chelating agent, inorganic acid, boron-based compound, additives and water, copper film, copper alloy film, titanium film, titanium alloy film, molybdenum film, molybdenum alloy film or multilayers in which they are laminated .
The method of claim 1,
The etching composition is 3 to 20% by weight of hydrogen peroxide, 0.1 to 5% by weight of sulfate, 0.001 to 2% by weight of fluorine compound, 0.1 to 5% by weight of chelating agent, 0.1 to 5% by weight of inorganic acid, 0.01 to 1% by weight of boron compound, An etching composition of a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, a molybdenum alloy film, or a multilayer film including these so as to have an additive of 0.1 to 5% by weight and a total weight of 100% by weight.
The method according to claim 2, wherein
The sulfate may be any one or a mixture of two or more selected from ammonium sulfate, ammonium persulfate, potassium sulfate, potassium persulfate, sodium sulfate, sodium persulfate, copper alloy film, titanium film, titanium alloy film, molybdenum film, molybdenum alloy Etch composition of a film or multiple films in which they are laminated.
The method of claim 2,
The fluorine compound is any one or a mixture of two or more selected from acidic ammonium fluoride, silicic acid, potassium hydrogen fluoride, hydrofluoric acid, copper alloy film, titanium film, titanium alloy film, molybdenum film, molybdenum alloy film or multiple stacked them Etch Composition of Membranes.
The method of claim 2,
The chelating agent is any one or a mixture of two or more selected from EDTA, imino diacetic acid, nitrilotriacetic acid, diethylene trinitrolopentaacetic acid, copper alloy film, titanium film, titanium alloy film, molybdenum film, molybdenum alloy Etch composition of a film or multiple films in which they are laminated.
The method of claim 2,
The inorganic acid is an etching composition of a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, a molybdenum alloy film, or a multilayer film in which they are one or two or more selected from hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and perchloric acid. .
The method of claim 2,
The boron-based compound may be a copper film, a copper alloy film, a titanium film, a titanium alloy film, a molybdenum film, a molybdenum alloy film, or a multilayer film of these, which is one or a mixture of two or more selected from boric acid, borate, boron oxide, and borazole. Etch composition.
The method of claim 2,
The additive is any one or two or more azole compounds selected from 5-aminotetrazole, 1,2,3-benzotriazole, methylbenzotriazole, imidazole, copper alloy film, titanium film, titanium alloy An etching composition of a film, a molybdenum film, a molybdenum alloy film, or a multilayer film in which they are laminated.

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