KR20140065618A - Method of manufacturing an array substrate for liquid crystal display device - Google Patents

Abstract

The present invention relates to an etchant composition of a silicon nitride layer which includes A) a fluorine-containing compound, B) inorganic acid, C) an azole-containing compound, and D) remaining water in the total weight of the composition. The etchant composition according to the present invention etches a silicon nitride layer without damaging a copper wire, reduces manufacturing costs, and improves productivity in an etching process of an insulation layer like the silicon nitride layer to connect a pixel electrode to the copper wire in a process for manufacturing an array substrate for a liquid crystal display device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device,

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display, and more particularly, to a method of manufacturing an array substrate for a liquid crystal display using a silicon nitride film etchant composition without damages in copper-based interconnects.

One of the most widely used flat panel displays is a liquid crystal display (LCD). The liquid crystal display device may include a substrate on which a plurality of pixel electrodes are arranged in a matrix form and a substrate on which one common electrode is covered. In such a liquid crystal display device, .

To this end, a thin film transistor for switching the voltage applied to the pixel electrode is connected to each pixel electrode, a gate line for transmitting a signal for controlling the thin film transistor, and a data line for transmitting a voltage to be applied to the pixel electrode a data line is formed on the substrate.

On the other hand, as the display area of the liquid crystal display device becomes larger and larger, the gate lines and data lines connected to the thin film transistors become longer, and accordingly the resistance of the wirings also increases. For this reason, the continuous use of chromium (Cr), molybdenum (Mo), aluminum (Al), and alloys thereof, which have been conventionally used, as gates and data wirings used in thin film transistors Which makes it difficult to make the flat panel display large-sized and high-resolution realization. Therefore, in order to solve such a problem of signal delay due to such an increase in resistance, it is necessary to form the gate line and the data line with a material having the lowest possible resistivity.

Korean Patent Publication No. 2007-0009329 discloses that a protective film of silicon nitride (SiNx), for example, amorphous silicon nitride or silicon oxide (SiO ₂ ), for example, low-temperature amorphous silicon oxide is formed on the data wiring, Discloses a thin film transistor substrate manufactured by using a method of forming a contact hole electrically connected to a drain electrode through a contact hole and forming a pixel electrode located in a pixel.

In the above technique, the gate wiring is formed of a silver conductive layer, but silver is vulnerable to heat, and a subsequent process for forming an insulating film or the like must proceed at a low temperature. However, the insulating film formed in such a low-temperature process is relatively harder than the film formed in the high-temperature process, and it is difficult to control the etch rate when the insulating film is patterned by a conventional dry etching method to form contact holes In addition, an undercut may occur and the etching profile may be formed as a reverse taper. Further, the gate wiring or the data wiring exposed by the etching process may be oxidized and discolored. In addition, the dry etching process is costly because it uses expensive equipment, and it can take a lot of time and thus be unproductive.

Therefore, when the gate wiring and the data wiring are formed of a material having the lowest resistivity and the silicon nitride film is used as the insulating film, the silicon nitride film is etched without damaging the data wiring by wet etching instead of dry etching in the silicon nitride film etching process Studies are underway to reduce manufacturing costs and improve productivity, and a suitable etching composition is required.

KR 2007-0009329 A

In the manufacturing process of the array substrate for a liquid crystal display device, the silicon nitride film is etched without damaging the copper-based wiring by wet etching in an etching process of an insulating film for connecting the pixel electrode and the copper- And to provide an etchant composition capable of reducing manufacturing costs and improving productivity.

In order to achieve the above object,

Based on the total weight of the composition, A) 0.1 to 10.0% by weight of a fluorine compound, B) 2.0 to 10.0% by weight of inorganic acid, 0.01 to 5.0% by weight of an azole compound, and D) Lt; / RTI >

In addition,

I) forming a gate layer having a gate electrode and a gate line on a substrate; II) forming a common line in parallel with the gate line at the center between two adjacent gate lines; III) forming a data layer having a drain electrode, a source electrode and a data line on the gate layer and the common line; (IV) forming a silicon nitride layer (passivation layer) to cover the data layer; Forming a contact hole in the silicon nitride layer and then forming a pixel electrode in contact with the drain electrode through the contact hole; and (VI) forming a contact hole, which is alternated with the pixel electrode and is in contact with the common line through the contact hole, A method of manufacturing an array substrate for a liquid crystal display, comprising the steps of:

 In the step (V), etching the silicon nitride layer with an etchant composition to form a contact hole connecting the pixel electrode and the copper-based wiring,

The step (VI) includes etching the silicon nitride film with an etchant composition to form a common electrode,

Wherein the etchant composition comprises, relative to the total weight of the composition, A) from 0.1 to 10.0% by weight of a fluorinated compound, B) from 2.0 to 10.0% by weight of inorganic acids, from 0.01 to 5.0% by weight of an azole compound, and D) And a plurality of pixel electrodes formed on the substrate.

In the etching liquid composition according to the present invention, in the process of manufacturing the array substrate for a liquid crystal display device, the silicon nitride film is etched without damaging the copper-based wiring in the etching process of the insulating film for connecting the pixel electrode and the copper- , The manufacturing cost can be reduced and the productivity can be improved.

1 is an SEM image of a drain copper-based wiring etched with the etching composition of Example 3. Fig.
2 is an SEM image of a drain copper-based wiring etched with the etchant composition of Comparative Example 1. Fig.
3 is an SEM image of a drain copper-based wiring etched with the etchant composition of Comparative Example 2. Fig.

Hereinafter, the present invention will be described in detail.

The present invention relates to a composition comprising: A) from 0.1 to 10.0% by weight of a fluorine compound, B) from 2.0 to 10.0% by weight of inorganic acid, from 0.01 to 5.0% by weight of an azole compound, and D) To an etchant composition for a nitride film.

The fluorine-containing compound (A) contained in the silicon nitride-based etchant composition of the present invention means a compound dissociated in water and capable of emitting fluorine ions. The A) fluorine compound is a main component that affects the etching rate of silicon, which is one of the components of the silicon nitride film, and controls the etching rate of the silicon nitride film.

The composition containing the fluorine-containing compound (A) in an amount of 0.1 to 10.0% by weight, preferably 3.0 to 5.0% by weight based on the total weight of the composition is particularly preferable. If it is contained within the above-mentioned range, the etching rate of the silicon nitride film becomes slow. If it exceeds the above-mentioned range, the etching performance of the silicon nitride film is improved, but it may lead to a process failure such as shorting the wiring by etching the copper-based wiring located under the silicon nitride film.

The A) fluorine compound is not particularly limited as long as it is used in the art. However, the A) fluorine compound is preferably one selected from the group consisting of HF, NaF, NH ₄ F, NH ₄ BF ₄ , NH ₄ FHF, KF, KHF ₂ , AlF ₃ and HBF ₄ , More preferable.

The B) inorganic acid contained in the silicon nitride film etchant composition of the present invention is preferably contained in an amount of 2.0 to 10.0% by weight, more preferably 3.0 to 5.0% by weight based on the total weight of the composition. If the content of the inorganic acid is less than 2.0 wt%, the etching rate of the silicon nitride film suitable for the process can not be provided. If the content of the inorganic acid exceeds 10.0 wt%, the copper wiring located below the silicon nitride film may be etched to shorten the wiring. have.

The B) inorganic acid is preferably one selected from the group consisting of phosphoric acid, hydrochloric acid, nitric acid and sulfuric acid, more preferably phosphoric acid.

The C) azole-based compound contained in the silicon nitride film etchant composition of the present invention protects the copper-based wiring located under the silicon nitride film etching process. In general, after the silicon nitride film is etched in the silicon nitride film etching process, the copper wiring is exposed to the etching solution. At this time, the etchant may cause a process failure such as shorting the wiring by etching the copper-based wiring located under the silicon nitride film. Therefore, the silicon nitride film etchant composition of the present invention contains an azole-based compound as a protective component of the copper-based wiring to minimize the damage of the copper-based wiring during the silicon nitride film etching process.

The C) azole-based compound is contained in an amount of 0.01 to 5.0% by weight, preferably 0.05 to 0.5% by weight, based on the total weight of the composition. If it is included within the above-mentioned range, the copper-based wiring located at the bottom may be etched to cause defective wiring. If it exceeds the above range, the reduction of the etching rate of the silicon nitride film and the damage of the copper-based wiring do not occur, but it is preferable that the above range is not taken into account when considering the high price of 1,2,3 benzotriazole Do.

The C) azole-based compound is not particularly limited as long as it is used in the art. However, the azole-based compound is preferably an azole-based compound having 1 to 30 carbon atoms. The azole compound may be a benzotriazole compound, an aminotetrazole compound, an imidazole compound, an indole compound, a purine compound, a pyrazole compound, a pyridine compound, a pyrimidine compound, a pyrrole compound, Compound and a pyrrole-based compound. Among them, examples of the aminotetrazole-based compounds include aminotetrazole, 5-amino-1-phenyltetrazole, 5-amino-1 (1-naphthyl) tetrazole, , 1,5-diaminotetrazole, and the like. Of these, 1,2,3 benzotriazole is preferable.

The water (C) contained in the silicon nitride film etchant composition of the present invention is contained in such an amount that the total weight of the composition is 100% by weight. The water is not particularly limited, but it is preferable to use deionized water. Further, it is more preferable to use deionized water having a specific resistance of water of 18 M OMEGA. Or more to show the degree of removal of ions in water.

The present invention also provides a method of manufacturing a semiconductor device, comprising the steps of: I) forming a gate layer having a gate electrode and a gate line on a substrate; II) forming a common line in parallel with the gate line at the center between two adjacent gate lines; III) forming a data layer having a drain electrode, a source electrode and a data line on the gate layer and the common line; (IV) forming a silicon nitride layer (passivation layer) to cover the data layer; Forming a contact hole in the silicon nitride layer and then forming a pixel electrode in contact with the drain electrode through the contact hole; and (VI) forming a contact hole, which is alternated with the pixel electrode and is in contact with the common line through the contact hole, A method of manufacturing an array substrate for a liquid crystal display, comprising the steps of:

 In the step (V), etching the silicon nitride layer with an etchant composition to form a contact hole connecting the pixel electrode and the copper-based wiring,

The step (VI) includes etching the silicon nitride film with an etchant composition to form a common electrode,

Wherein the etchant composition comprises, relative to the total weight of the composition, A) from 0.1 to 10.0% by weight of a fluorinated compound, B) from 2.0 to 10.0% by weight of inorganic acids, from 0.01 to 5.0% by weight of an azole compound, and D) The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device.

The array substrate for a liquid crystal display may be a thin film transistor (TFT) array substrate. The array substrate for a liquid crystal display includes a silicon nitride film etched using the etching liquid composition of the present invention.

The step of etching the silicon nitride film with the etchant composition may be performed according to a well-known method in the art, and examples thereof include immersion and shedding. The temperature in the etching process is generally 20 to 50 ° C, preferably 30 to 45 ° C, and the optimum process temperature is determined as necessary depending on other process conditions and factors.

The time for etching the silicon nitride film with the etchant composition may vary depending on the temperature and the thickness of the thin film, but is usually several seconds to several tens of minutes.

The present invention also provides an array substrate for a liquid crystal display comprising a silicon nitride film etched using the etchant composition.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

<Examples>

Etchant  Preparation of composition

The etchant compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were prepared according to the compositions shown in Table 1 below.

Unit: wt% HF Phosphoric acid 1,2,3 benzotriazole Deionized water Example 1 1.0 3.0 0.5 Balance Example 2 3.0 3.0 0.5 Balance Example 3 5.0 3.0 0.5 Balance Comparative Example 1 1.0 20.0 0.1 Balance Comparative Example 2 15.0 3.0 0.5 Balance

Test Example : Etchant  Evaluation of composition characteristics

A SiNx / Cu bilayer was formed on the substrate, and the specimen was prepared by cutting it to 10 x 10 mm using a diamond knife. (ETCHER (TFT), manufactured by SEMES) was used as the etchant, and the temperature of the etchant composition was set to about 40 ° C during the etching process. However, the optimum temperature was determined according to other process conditions and other factors can be changed. The etching time may vary depending on the etching temperature, but usually proceeds to about 100 seconds.

The substrates were taken out after etching, washed with deionized water, dried using a hot air drying apparatus, and photoresist was removed using a photoresist (PR) stripper. After cleaning and drying, the etching state of the silicon nitride film and the copper-based wiring etched in the etching process was examined using an electron microscope (SEM; model name: S-4700, manufactured by Hitachi, Ltd.) .

Composition Silicon nitride film etching rate (Å / sec) Copper-based wiring Damage Test Example 1 Example 1 9.1 radish Test Example 2 Example 2 31.7 radish Test Example 3 Example 3 50.0 radish Comparative Test Example 1 Comparative Example 1 9.2 U Comparative Test Example 2 Comparative Example 2 180.2 U

As can be seen from the above Table 2, it was confirmed that the etching rate of the silicon nitride films of the etching solutions of Examples 1 to 3 was increased as the HF composition content was increased. As can be seen from FIG. 1, when the HF composition was less than 10.0 wt%, damage was not generated in the copper-based wiring. However, as shown in Table 2 and FIG. 2, the etchant of Comparative Example 1 was found to cause damages in the copper-based wiring when the phosphoric acid composition content exceeded 10.0% by weight (FIG. 2). As can be seen from FIG. 3, in the etching solution of Comparative Example 2, the etching rate of the silicon nitride film was increased when the fluorinated compound content was more than 10.0 wt%, but damages were observed in the copper wiring.

Claims (8)

I) forming a gate layer having a gate electrode and a gate line on a substrate;
II) forming a common line in parallel with the gate line at the center between two adjacent gate lines;
III) forming a data layer having a drain electrode, a source electrode and a data line on the gate layer and the common line;
(IV) forming a silicon nitride layer (passivation layer) to cover the data layer;
(V) forming a pixel electrode in contact with the drain electrode through the contact hole after forming a contact hole in the silicon nitride film; and
And forming a common electrode alternating with the pixel electrode and in contact with the common line through the contact hole, the method comprising the steps of:
In the step (V), etching the silicon nitride layer with an etchant composition to form a contact hole connecting the pixel electrode and the copper-based wiring,
The step (VI) includes etching the silicon nitride film with an etchant composition to form a common electrode,
Wherein the etchant composition comprises, relative to the total weight of the composition, A) from 0.1 to 10.0% by weight of a fluorinated compound, B) from 2.0 to 10.0% by weight of inorganic acids, from 0.01 to 5.0% by weight of an azole compound, and D) Wherein the first substrate and the second substrate are bonded to each other. The method of manufacturing an array substrate for a liquid crystal display according to claim 1, wherein the array substrate for a liquid crystal display is a thin film transistor (TFT) array substrate. Based on the total weight of the composition, A) 0.1 to 10.0% by weight of a fluorine compound, B) 2.0 to 10.0% by weight of inorganic acid, 0.01 to 5.0% by weight of an azole compound, and D) Composition. [4] The method of claim 3, wherein the A) fluorine compound is one selected from the group consisting of HF, NaF, NH ₄ F, NH ₄ BF ₄ , NH ₄ FHF, KF, KHF ₂ , AlF ₃ and HBF ₄ Wherein the etching solution composition is a silicon nitride film.  The etching composition of claim 3, wherein the inorganic acid (B) is one selected from the group consisting of phosphoric acid, hydrochloric acid, nitric acid, and sulfuric acid.  [4] The method according to claim 3, wherein the C) azole compound is at least one selected from the group consisting of a benzotriazole compound, an aminotetrazole compound, an imidazole compound, an indole compound, a purine compound, a pyrazole compound, a pyridine compound, Wherein the silicon nitride compound is one selected from the group consisting of a compound, a pyrrolidine compound, and a pyrrole compound.  7. The method of claim 6, wherein the aminotetrazole-based compound is selected from the group consisting of an aminotetrazole, a 5-amino-1-phenyltetrazole, a 5-amino- , 5-diaminotetrazole, and the like. An array substrate for a liquid crystal display device comprising a silicon nitride film etched using the etchant composition of claim 3.

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