TWI510848B - Etchant composistion of etching a commper-based metal layer and method of fabricating an array substrate for a liquid crystal display - Google Patents

Description

Etchant composition, method of etching copper-based metal layer, and method for manufacturing array substrate for liquid crystal display device

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device.

Forming the metal wiring on the substrate of the semiconductor device includes forming a metal layer, applying a photoresist, performing exposure and development to form a photoresist on the selective region, and performing etching. Forming the metal wiring again includes performing a cleaning procedure before and after the respective programs. The etching process uses photoresist as a mask to form a metal layer on the selective regions, and the etching process generally includes dry etching using plasma or wet etching using an etchant composition.

In this semiconductor device, the resistance of the metal wiring has recently been regarded as important. This is because resistance is the main factor in inducing the delay of the RC signal. In particular, in the case of a thin film transistor-liquid crystal display device (TFT-LCD), related art has been developed to increase the size of the panel and achieve high resolution. Therefore, in order to achieve a reduction in the RC signal delay necessary to increase the size of the TFT-LCD, it is necessary to develop a material having a low resistance. Conventionally, chromium (Cr, resistivity: 12.7 × 10 ^-8 ohm meters), molybdenum (Mo, resistivity: 5 × 10 ^-8 ohm meters), aluminum (Al, resistivity: 2.65 × 10 ^-8 ohms) are mainly used. M), and its alloys, but in fact it is difficult to use for the gate and data wiring of large TFT-LCDs.

Accordingly, the present invention is intended to provide an etchant composition for a copper (Cu)-based metal layer in which a tapered shape having a high linearity is formed when etching a Cu-based metal layer, and there is no etching residue.

Further, the present invention is to provide an etchant composition for a Cu-based metal layer which etches a gate, a gate wiring, a source/drain, and a data wiring.

Still further, the present invention is to provide a method of etching a Cu-based metal layer, and a method of manufacturing an array substrate for a liquid crystal display device using the above etchant composition.

An embodiment of the present invention provides a method of manufacturing an array substrate for a liquid crystal display device, comprising: 1) etching a Cu-based metal layer disposed on a substrate using an etchant composition, thereby forming a gate; 2) forming a gate Insulating gate insulating layer; 3) forming a semiconductor layer on the gate insulating layer; 4) forming an insulating layer for insulating the semiconductor layer; 5) forming a Cu-based metal layer on the insulating layer insulating the semiconductor layer, and using etching The agent composition etches the copper-based metal layer, thereby forming the source/drain; and 6) forming the pixel electrode electrically connected to the drain, wherein the etchant compositions of 1) and 5) comprise a by weight of the total composition 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of an organic acid; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight of water-soluble a cyclic amine compound; e) 0.1 to 5% by weight of a water-soluble compound having one nitrogen atom and one carboxyl group per molecule; f) 0.01 to 1.0% by weight of a fluorine-containing (F) compound; g) 0.001 to 5% by weight a polyol surfactant; and h) the remainder being water.

Another embodiment of the present invention provides a method of etching a Cu-based metal layer, comprising: A) forming a Cu-based metal layer on a substrate; B) selectively disposing a photo-reactive material on the Cu-based metal layer; and C) The Cu-based metal layer is etched using an etchant composition, wherein the etchant composition comprises a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ), b) 0.1 to 5% by weight based on the total weight of the composition Organic acid; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight of a water-soluble cyclic amine compound; e) 0.1 to 5% by weight of each molecule having a nitrogen atom and a carboxyl group in water-soluble a compound; f) 0.01 to 1.0% by weight of the F-containing compound; g) 0.001 to 5% by weight of the polyol surfactant; and h) the balance being water.

A further embodiment of the present invention provides an etchant composition for a Cu-based metal layer, which comprises a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ), based on the total weight of the composition; b) 0.1 to 5% by weight of an organic acid; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight of a water-soluble cyclic amine compound; e) 0.1 to 5% by weight of each molecule having a nitrogen atom a water-soluble compound with one carboxyl group; f) 0.01 to 1.0% by weight of the F-containing compound; g) 0.001 to 5% by weight of a polyol surfactant; and h) the remainder being water.

The following is a detailed description of the invention.

The present invention relates to an etchant composition for a Cu-based metal layer comprising a) hydrogen peroxide (H ₂ O ₂ ), b) an organic acid, c) a phosphate compound, d) a water-soluble cyclic amine compound, e) Each molecule has a water-soluble compound of a nitrogen atom and a carboxyl group, f) an F-containing compound, g) a polyol surfactant, and h) water.

In the present invention, the Cu-based metal layer (including Cu) may have a single layer structure, or a multilayer structure including a double layer or the like, and examples thereof include a single layer of Cu or a Cu alloy, and a multilayer thereof (such as Cu-Mo) Layer or Cu-Mo alloy layer). The Cu-Mo layer includes a Mo layer and a Cu layer formed on the Mo layer, and the Cu-Mo alloy layer includes a Mo alloy layer and a Cu layer formed on the Mo alloy layer. Further, the Mo alloy layer is composed of Mo and one or more selected from the group consisting of titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), niobium (Nd), and indium (In). .

In the etchant composition according to the present invention, a) hydrogen peroxide (H ₂ O ₂ ) is a main component for etching a Cu-based metal layer. a) Hydrogen peroxide (H ₂ O ₂ ) is used in an amount of 5 to 25% by weight, and preferably 10 to 20% by weight, based on the total mass of the composition. If the amount is less than the lower limit of the above range, the Cu-based metal layer cannot be etched or the etching rate may be too slow. Conversely, if the amount exceeds the upper limit of the above range, the total etching rate may become faster, making it difficult to control the program.

In the etchant composition according to the present invention, b) the function of the organic acid is to appropriately adjust the pH of the etchant composition to form a condition in which the etchant composition is very suitable for etching the Cu-based metal layer. b) The organic acid is used in an amount of 0.1 to 5% by weight, and preferably 1 to 3% by weight, based on the total weight of the composition. If the amount is less than the lower limit of the above range, the ability to adjust the pH may be insufficient, so it is difficult to maintain the pH at about 0.5 to 4.5. Conversely, if the amount exceeds the upper limit of the above range, the Cu etching rate may become faster, and the Mo or Mo alloy etching rate may become slow, so CD loss may increase. In addition, the probability of producing Mo or Mo alloy residues may increase.

b) The organic acid may comprise one or more selected from the group consisting of acetic acid, butyric acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, valeric acid, and oxalic acid.

In the etchant composition according to the present invention, c) the phosphate compound is a component which makes the shape of the tapered shape of the pattern good. If the c) phosphate compound is not included in the etchant composition according to the present invention, the etching profile may be poor. c) The phosphate compound is used in an amount of from 0.1 to 5% by weight, based on the total weight of the composition, and preferably from 0.5 to 3% by weight. If the amount is less than the lower limit of the above range, the etching profile may be poor. Conversely, if the amount exceeds the upper limit of the above range, the etching rate may become slow.

c) the phosphate compound is not particularly limited as long as it is selected from phosphates in which a hydrogen atom of phosphoric acid is replaced by a monovalent or divalent cation, and may include a group selected from the group consisting of sodium phosphate, potassium phosphate and ammonium phosphate. One or more.

In the etchant composition according to the present invention, d) the function of the water-soluble cyclic amine compound is to control the Cu metal etch rate and reduce the CD loss of the pattern, increasing the process margin. d) The water-soluble cyclic amine compound is used in an amount of 0.1 to 5% by weight, and preferably 1 to 3% by weight, based on the total weight of the composition. If the amount is less than the lower limit of the above range, too much CD loss may occur. Conversely, if the amount exceeds the upper limit of the above range, the Cu etching rate may increase, and the etching rate of Mo or Mo alloy may decrease, so CD loss may increase. In addition, the probability of producing Mo or Mo alloy residues may increase.

d) the water-soluble cyclic amine compound may comprise one or more selected from the group consisting of aminotetrazole, imidazole, hydrazine, hydrazine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine, and pyrroline. .

In the etchant composition according to the present invention, e) a water-soluble compound having one nitrogen atom and one carboxyl group per molecule functions to prevent self-decomposition of the hydrogen peroxide solution when storing the etchant composition, and also to etch more The sheet substrate is prevented from changing in etching properties. The etchant composition is typically stored using a hydrogen peroxide solution, the storage time of which is not long due to the self-decomposition of the hydrogen peroxide solution, and the risk of explosion of the container. However, if a water-soluble compound having one nitrogen atom and one carboxyl group per molecule is contained, the rate of decomposition of the hydrogen peroxide solution is reduced by about 10 times, which advantageously ensures the removal time and stability. In particular, in the case of the Cu layer, if Cu ions are present in a large amount in the etchant composition, it may occur that the oxidation is blackened due to the formation of the passivation layer, and then the etching is no longer performed. However, this phenomenon can be prevented if a water-soluble compound having one nitrogen atom and one carboxyl group per molecule is contained.

e) The water-soluble compound having one nitrogen atom and one carboxyl group per molecule is contained in an amount of from 0.1 to 5% by weight, and preferably from 0.5 to 2% by weight, based on the total mass of the composition. If the amount is less than the lower limit of the above range, a passivation layer may be formed after etching a plurality of substrates (about 500 substrates), thus making it difficult to obtain a sufficient program margin. Conversely, if the amount exceeds the upper limit of the above range, the Cu etching rate may be lowered, and the etching rate of the Mo or Mo alloy may increase, so the taper angle may become large when the Cu-Mo layer or the Cu-Mo alloy layer is used. .

e) a water-soluble compound having one nitrogen atom and one carboxyl group per molecule may be selected from the group consisting of alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrostriacetic acid, and muscle One or more of the groups consisting of amino acids.

f) The compound containing F is a compound which dissociates in water to produce F ions. f) The function of the F-containing compound is to remove the etching residue inevitably generated from the etchant which simultaneously etches the Cu layer and the Mo layer. f) The compound containing F is contained in an amount of from 0.01 to 1.0% by weight, based on the total weight of the composition, and preferably from 0.1 to 0.5% by weight. If the amount is less than the lower limit of the above range, an etching residue may be generated. Conversely, if the amount exceeds the upper limit of the above range, the rate at which the glass substrate is etched may increase.

f) The F-containing compound may include any material used in the art without limitation as long as it dissociates into a F ion or a polyatomic F ion in a solution, and may include a selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, One or more of the group consisting of ammonium hydrofluoride, sodium hydrofluoride, and potassium hydrofluoride.

In the etchant composition according to the present invention, the function of the g) polyol surfactant is to reduce the surface tension to increase the etching uniformity. Further, g) the polyol surfactant is formed by eluting the Cu layer to the vicinity of Cu ions in the etchant after etching the Cu layer, thereby suppressing the activity of Cu ions and suppressing decomposition of hydrogen peroxide. When the activity of Cu ions is lowered in this manner, an etching agent is used to stabilize the etching process. g) The polyol surfactant comprises 0.001 to 5% by weight, and preferably 0.1 to 3% by weight, based on the total weight of the composition. If the amount is less than the lower limit of the above range, the etching uniformity may be lowered, and the decomposition of hydrogen peroxide may be accelerated. Conversely, if the amount exceeds the upper limit of the above range, a large amount of foam may be generated.

g) The polyol surfactant may comprise one or more selected from the group consisting of glycerol, triethylene glycol and polyethylene glycol.

In the etchant composition according to the present invention, h) the amount remaining in the water system, and the kind thereof is not particularly limited, but deionized water is preferred. Particularly useful is deionized water having a resistivity of 18 million ohms/cm or greater, which is the extent to which ions are removed from water.

In addition to the above ingredients, the etchant composition according to the present invention may further comprise a typical additive. Examples of the additive may include a chelating agent, an anticorrosive agent, and the like.

Further, the additive is not limited thereto, and in order to make the effect of the present invention better, other additives known in the art may be used.

Used in the present invention a) hydrogen peroxide (H ₂ O ₂ ), b) organic acid, c) phosphate compound, d) water-soluble cyclic amine compound, e) water-soluble one molecule per molecule with one carboxyl group The compound, f) the F-containing compound, and g) the polyol surfactant are preferably of a purity suitable for use in a semiconductor process.

According to the etchant composition for a Cu-based metal layer of the present invention, the gate, the gate wiring, the source/drain, and the data wiring of the liquid crystal display device made of a Cu-based metal can be etched together.

Furthermore, the present invention relates to a method of etching a Cu-based metal layer, which comprises

A) forming a Cu-based metal layer on the substrate,

B) selectively arranging a photoreactive material on the Cu-based metal layer, and

C) Etching the Cu-based metal layer using the etchant composition in accordance with the present invention.

In the etching method according to the present invention, the photoreactive material may be a typical photoresist and may be selectively disposed using typical exposure and development.

Furthermore, the present invention relates to a method of manufacturing an array substrate for a liquid crystal display device, which comprises

1) etching a Cu-based metal layer disposed on the substrate using an etchant composition, thereby forming a gate;

2) forming a gate insulating layer that insulates the gate;

3) forming a semiconductor layer on the gate insulating layer;

4) forming an insulating layer that insulates the semiconductor layer;

5) forming a Cu-based metal layer on the insulating layer that insulates the semiconductor layer, and etching the copper-based metal layer using the etchant composition, thereby forming a source/drain, and

6) forming a pixel electrode electrically connected to the drain,

The etchant compositions of 1) and 5) are etchant compositions in accordance with the present invention.

The array substrate for the liquid crystal display device may be a TFT array substrate.

The invention may be better understood by the following description, which is not to be construed as limiting.

Examples 1 to 6: Preparation of an etchant composition for a Cu-based metal layer

The etchant compositions of Examples 1 to 6 were prepared in accordance with the ingredients shown in Table 1 below.

Test case: Evaluation of the properties of the etchant composition

Etching of a Cu-based metal layer (Cu single layer and Cu/Mo-Ti double layer) was carried out using the etchant compositions of Examples 1 to 6. The temperature of the etchant composition is set to about 30 ° C at the time of etching, but it may be appropriately changed in accordance with other program conditions and factors. Further, although the etching time may vary depending on the etching temperature, it is usually set to about 30 to 180 seconds. The cross-sectional profile of the etched Cu-based metal layer was observed using an SEM (S-4700, available from Hitachi) in an etching procedure. The results are shown in Table 2 below.

As shown in Table 2, the Cu-based metal etching rate using the etchant compositions of Examples 1 to 6 was appropriate. As shown in Figures 1 and 2, the Cu layer etched using the etchant composition of Example 1 exhibited a good etch profile. As shown in Fig. 3, there was no etching residue when the Cu layer was etched using the etchant composition of Example 1.

Therefore, the etchant composition according to the present invention is advantageous in providing an excellent tip shape, pattern linearity, and a suitable etching rate of the Cu-based metal layer, and particularly, no etching residue remains after the etching.

As described above, the present invention provides a method of manufacturing an array substrate for a liquid crystal display device. According to the present invention, the etchant composition can form a tapered shape having an excellent linearity when etching the Cu-based metal layer. Further, when the Cu-based metal layer is etched using the etchant composition according to the present invention, no etching residue is generated, so that occurrence of electrical short-circuit, wiring failure, or low lightness is prevented. Further, if an array substrate for a liquid crystal display device is manufactured using the etchant composition according to the present invention, the etching process can be greatly simplified and the program yield can be maximized because the gate, the gate wiring, the source/drainage can be etched together , and data wiring. Further, the Cu or Cu alloy wiring having low resistance is etched using the etchant composition according to the present invention, thereby fabricating an array substrate for a liquid crystal display device having a large screen and high luminance circuit and being environmentally friendly.

Although the preferred embodiment of the present invention has been disclosed for purposes of illustration, it will be understood by those skilled in the art that various modifications, additions and substitutions can be made without departing from the scope and spirit of the invention disclosed in the appended claims. .

The features and advantages of the present invention will be more clearly understood from the description of the appended claims.

1 is a scanning electron microscope (SEM) image showing a cross section of a Cu/Mo-Ti layer etched using an etchant composition according to Embodiment 1 of the present invention;

2 is an SEM image showing the overall shape of a Cu/Mo-Ti layer etched using the etchant composition according to Embodiment 1 of the present invention;

Fig. 3 is a SEM image showing the vicinity of the Cu wiring of the Cu/Mo-Ti layer etched using the etchant composition according to Example 1 of the present invention in order to confirm the absence of etching residue.

Claims (10)

A method of manufacturing an array substrate for a liquid crystal display device, comprising: 1) etching a copper-based metal layer disposed on a substrate using an etchant composition, thereby forming a gate; 2) forming a gate insulating the gate insulating a layer; 3) forming a semiconductor layer on the gate insulating layer; 4) forming an insulating layer insulating the semiconductor layer; 5) forming a copper-based metal layer on the insulating layer insulating the semiconductor layer, and using the etching The agent composition etches the copper-based metal layer, thereby forming a source/drain; and 6) forming a pixel electrode electrically connected to the drain, wherein the etchant composition of 1) and 5) is based on the total weight of the composition Containing a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of an organic acid; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight a water-soluble cyclic amine compound; e) 0.1 to 5% by weight of a water-soluble compound having one nitrogen atom and one carboxyl group per molecule; f) 0.01 to 1.0% by weight of a fluorine-containing compound; g) 0.001 to 5% by weight Triethylene glycol; and h) the rest is water. The method of claim 1, wherein the array substrate for the liquid crystal display device is a thin film transistor (TFT) array substrate. A method of etching a copper-based metal layer, comprising: A) forming a copper-based metal layer on a substrate; B) selectively disposing a photo-reactive material on the copper-based metal layer; and C) etching using an etchant composition The copper-based metal layer, wherein the etchant composition comprises a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of an organic acid, based on the total weight of the composition; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight of a water-soluble cyclic amine compound; e) 0.1 to 5% by weight of a water-soluble compound having one nitrogen atom and one carboxyl group per molecule; ) 0.01 to 1.0% by weight of a fluorine-containing compound; g) 0.001 to 5% by weight of triethylene glycol; and h) the balance being water. An etchant composition for a copper-based metal layer, which comprises, based on the total weight of the composition, a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of organic Acid; c) 0.1 to 5% by weight of a phosphate compound; d) 0.1 to 5% by weight of a water-soluble cyclic amine compound; e) 0.1 to 5% by weight of a water-soluble compound having one nitrogen atom and one carboxyl group per molecule ; f) 0.01 to 1.0% by weight of the fluorine-containing compound; g) 0.001 to 5% by weight of triethylene glycol; and h) the balance being water. An etchant composition according to claim 4, wherein b) the organic acid comprises a group selected from the group consisting of acetic acid, butyric acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, valeric acid, and oxalic acid. One or more. An etchant composition according to claim 4, wherein the c) phosphate compound comprises one or more selected from the group consisting of sodium phosphate, potassium phosphate and ammonium phosphate. Such as the etchant composition of claim 4, wherein d) water soluble The cyclic amine compound comprises one or more selected from the group consisting of aminotetrazole, imidazole, indole, indole, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine, and pyrroline. An etchant composition as claimed in claim 4, wherein e) the water-soluble compound having one nitrogen atom and one carboxyl group per molecule comprises selected from the group consisting of alanine, aminobutyric acid, glutamic acid, glycine, and sub One or more of the group consisting of aminodiacetic acid, nitrostriacetic acid, and sarcosine. The etchant composition of claim 4, wherein the f) fluorine-containing compound comprises one or more selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, NH ₄ F, KF, and NaF. The etchant composition of claim 4, wherein the copper-based metal layer is a single layer of copper or a copper alloy, a copper-molybdenum layer comprising a molybdenum layer and a copper layer formed on the molybdenum layer, or a molybdenum alloy A copper-molybdenum alloy layer of a layer and a copper layer formed on the molybdenum alloy layer.