KR20190050106A - Etchant composition for silver thin layer and ehting method and mehtod for fabrication metal pattern using the same - Google Patents

Abstract

The present invention relates to a silver etchant composition, including: 40-70 wt% of phosphoric acid; 2-9 wt% of nitric acid; 0.1-9 wt% of organic acid except anhydride; 0.1-9 wt% of an inorganic acid or organic acid compound; a remainder consisting of water such that the total weight of the composition is 100 wt%, and an etching method and a method for forming a metal pattern using the same.

Description

TECHNICAL FIELD The present invention relates to an etchant composition, an etching method using the same, and a method for forming a metal pattern.

The present invention relates to a silver etching composition and an etching method using the silver etching composition, and more particularly, to a silver etching composition containing 40 to 70% by weight of phosphoric acid based on the total weight of the composition. 2 to 9% by weight of nitric acid; 0.1 to 9% by weight of an organic acid; 0.1 to 9% by weight of an inorganic acid salt or organic acid salt compound; And a remaining amount of water so that the total weight of the composition is 100 wt%, and an etching method using the same and a method of forming a metal pattern.

As the era of information technology becomes full-scale, the display field for processing and displaying a large amount of information has been rapidly developed, and various flat panel displays have been developed in response to this.

Examples of such flat panel display devices include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display (FED), an electroluminescence Display devices (ELD), organic light emitting diodes (OLED), and the like. These flat panel display devices are used for various applications such as computers and mobile phones as well as home appliances such as televisions and videos. These flat panel display devices are rapidly replacing the conventional cathode ray tube (NIT) due to their excellent performance such as reduction in thickness, weight, and power consumption.

In particular, since the OLED emits light by itself and can be driven at a low voltage, it is rapidly applied to a small display market such as a portable device. In addition, OLED is expected to commercialize large-sized TV beyond small-sized display.

On the other hand, conductive metals such as indium tin oxide (ITO) and indium zinc oxide (IZO) have relatively high transmittance to light and have conductivity. Therefore, the electrode of a color filter used in a flat panel display Is widely used. However, these metals also have a high resistance, which is an obstacle to the enlargement of the flat panel display device and the realization of high resolution through improvement of the response speed.

In the case of reflectors, past aluminum (Al) reflectors have been mainly used for products, but in order to realize low power consumption through improvement of luminance, materials are being sought for metal with higher reflectance. For this purpose, a silver (Ag: specific resistance: about 1.59 μΩcm) film having a lower resistivity and a higher luminance than the metals applied to a flat panel display device, a silver alloy or a multilayer film including the same, It is required to develop an etchant for application of this material in order to realize a large-sized flat panel display device and high resolution and low power consumption.

However, silver (Ag) is extremely poor in adhesion to an insulating substrate such as glass or a lower substrate such as a semiconductor substrate made of intrinsic amorphous silicon or doped amorphous silicon or the like, lifting or peeling is easily induced. Further, even when a silver (Ag) conductive layer is deposited on a substrate, an etchant is used to pattern the same. When a conventional etching solution is used as the etching solution, silver (Ag) is excessively etched or non-uniformly etched to cause lifting or peeling of the wiring, resulting in poor lateral profile of the wiring. In particular, silver (Ag) is a metal that can be easily reduced and must be etched at a high rate so that it is etched without causing residue. At this time, there is no difference in etch rate between the upper and lower portions due to the etching rate. It is difficult to secure the straightness of the etch pattern, and thus it has many limitations in utilizing it for wiring. Particularly, in the conventional etchant composition, it is difficult to control the etch rate between the multilayered multilayered films when the Ag film and the transparent conductive film of ITO or IZO are laminated, there was.

Due to the above problem, when the metal film is standing vertically without a taper angle, voids may be generated between the silver (Ag) and the insulating film or wiring at the time of forming an insulating film or a subsequent wiring in a subsequent process, Causing electrical shorts and other defects.

As a representative example thereof, Korean Patent Laid-Open No. 10-2008-0110259 discloses a method for improving etching properties by adding phosphoric acid, nitric acid, acetic acid, sodium monophosphate (NaH ₂ PO ₄ ) And an ionic liquid. However, there is still a need in the art for an etchant composition having improved etch characteristics for silver, and active research has been conducted in response to the demand. However, etchant compositions having etchant properties that are significantly improved compared to the prior art It is not present.

Korean Registered Patent Korean Patent Publication No. 10-2008-0110259

The present invention relates to a method for manufacturing a semiconductor device, which comprises the steps of forming a silver or silver alloy having an etching property that is excellent in etch straightness and uniformity without occurrence of a problem of loss of lower wiring, residue (for example, silver residue and / or indium oxide film residue) And an etching solution composition for etching a multilayer film composed of the single film or the single film and the indium oxide film.

The present invention also provides an etching method using the above silver etching composition.

Further, there is provided a metal pattern forming method using the silver etchant composition.

In order to achieve the above object,

The present invention relates to a composition comprising 40 to 70% by weight phosphoric acid based on the total weight of the composition; 2 to 9% by weight of nitric acid; 0.1 to 9% by weight of an organic acid not containing acetic acid; 0.1 to 9% by weight of an inorganic acid salt or organic acid salt compound; And a remaining amount of water such that the total weight of the composition is 100% by weight.

The present invention also provides a method of manufacturing a semiconductor device, comprising: forming a single layer of silver or silver alloy on a substrate; or a multi-layered film composed of the single layer and the indium oxide layer; Selectively leaving a photoreactive material on the single layer of silver or silver alloy, or on the multi-layered film composed of the single layer and the indium oxide layer; And etching the multilayer film composed of the single film made of silver or silver alloy or the single film and the indium oxide film using the silver etching solution composition.

Forming a single film made of silver or silver alloy, or a multilayer film composed of said single film and an indium oxide film; Selectively leaving a photoreactive material on the single layer of silver or silver alloy, or on the multi-layered film composed of the single layer and the indium oxide layer; And etching the multi-layered film composed of the single film made of silver or silver alloy, or the single film and the indium oxide film using the silver etchant composition.

The silver etching solution composition of the present invention is a silver etching solution composition which is used for etching a single film made of silver or silver alloy or a multilayer film composed of the single film and the indium oxide film at the time of etching, Film residue) and silver have etch characteristics that are excellent in straightness and uniformity of etching without causing re-adsorption problems.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a composition comprising 40 to 70% by weight phosphoric acid based on the total weight of the composition; 2 to 9% by weight of nitric acid; 0.1 to 9% by weight of an organic acid not containing acetic acid; 0.1 to 9% by weight of an inorganic acid salt or organic acid salt compound; And a balance amount of water such that the total weight of the composition is 100% by weight. The present inventors have found that when the single layer made of silver or silver alloy or the multilayer composed of the single layer and the indium oxide layer is etched using the etching composition as described above, And / or an indium oxide film residue), and exhibits excellent etching straightness and uniformity without the occurrence of silver re-adsorption, thereby completing the present invention.

The silver etching solution composition of the present invention is characterized by being able to etch a single layer made of silver (Ag) or a silver alloy, or a multi-layered film composed of the single layer and the indium oxide layer, and the multi-layered film can be simultaneously etched.

The silver alloy contains silver as a main component and is in the form of an alloy containing other metals such as Nd, Cu, Pd, Nb, Ni, Mo, Ni, Cr, Mg, W and Ti and a nitride of silver, silicide, carbide and oxide And the like, but the present invention is not limited thereto.

The indium oxide is at least one selected from the group consisting of indium tin oxide (ITO), zinc indium oxide (IZO) and gallium indium zinc oxide (IGZO).

The multilayered film may be a multilayer film formed of indium oxide / silver, indium oxide / silver alloy, indium oxide / silver / indium oxide, indium oxide / silver alloy / indium oxide, In the case of using the composition, problems such as the problem of the loss of the lower wiring, the occurrence of the residue (for example, silver residue and indium oxide film residue) and the etching characteristic of the etching apparatus It does not cause browning problems and can be usefully used for wet etching.

Phosphoric acid (H ₃ PO ₄ ) contained in the silver etching solution composition of the present invention is used as a stocking agent and performs a redox reaction with silver (Ag) or a silver alloy when a single film or a multilayer film is etched and dissolves the indium oxide film to perform wet etching .

The phosphoric acid is included in an amount of 40 to 70% by weight, and preferably 50 to 60% by weight based on the total weight of the silver etching composition.

If the phosphoric acid content is less than 40% by weight based on the total weight of the composition, the etching ability is insufficient and sufficient etching may not be performed. Further, if the silver (Ag) is dissolved in the silver etching composition after a certain amount of the process is performed, re-adsorption of silver or silver (Ag) precipitate may occur and electrical short-circuit may occur in a subsequent process, .

If the content of phosphoric acid is more than 70% by weight based on the total weight of the composition, the etching rate of the indium oxide film is lowered and the etching rate of the silver or silver alloy is too fast to cause an overeating angle, It is possible to cause an etching amount that can not be performed. Further, in the case of a multilayer film in which an indium oxide film is laminated on a silver or silver alloy, a tip due to a difference in etching rate between the silver alloy and the indium oxide film is generated, which may cause a problem in a subsequent process.

The nitric acid (HNO ₃ ) contained in the silver etchant composition of the present invention serves as an auxiliary etchant and acts to wet-etch silver (Ag) or a silver alloy and an indium oxide film in a single-layer or multi- do.

The silver nitrate is included in an amount of 2 to 9% by weight, preferably 4 to 7% by weight based on the total weight of the etchant composition.

If the content of nitric acid is less than 2% by weight based on the total weight of the composition, the etching rate of the silver or silver alloy and the indium oxide film is lowered, thereby causing unevenness of the etch in the substrate. have.

If the content of nitric acid is more than 9% by weight based on the total weight of the composition, the etching speed of the upper and lower indium oxide films is accelerated, and over-etching of the upper and lower indium oxide films may cause problems in the subsequent process.

The organic acid contained in the silver etching solution composition of the present invention is characterized in that it does not contain acetic acid. In the case of acetic acid, it is vulnerable over time, and there is a disadvantage that wiring loss occurs.

On the contrary, other organic acids which do not contain nitric acid serve to control the etching rate with time and control the residue of the indium oxide film when wet etching.

As to the total weight of the composition, the organic acid is included in an amount of 0.1 to 9% by weight, preferably 1 to 3% by weight based on the total weight of the silver etching composition.

If the content of the organic acid is less than 0.1% by weight based on the total weight of the composition, the etching ability may degrade over time.

If the content of the organic acid is more than 9 wt% based on the total weight of the composition, the etch rate may increase over time, and wiring loss may occur.

The organic acid contained in the etchant of the present invention may be any organic acid other than acetic acid and may be selected from the group consisting of citric acid, glycine, butanoic acid, isocitric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, Salicylic acid, benzoic acid, lactic acid, glyceric acid, and propenoic acid. Preferably citric acid or glycine.

The inorganic acid salt or organic acid salt compound contained in the silver etching solution composition of the present invention is a component used as an Ag ligand. It is a component that reduces the adsorption of silver (Ag) on the thin film upon wet etching, It controls the etching rate.

As to the total weight of the composition, the inorganic acid salt and the organic acid salt compound are contained in an amount of 0.1 to 9 wt%, preferably 1.0 to 3 wt%, based on the total weight of the silver etching composition.

If the content of the inorganic acid salt or the organic acid salt compound is less than 0.1% by weight based on the total weight of the composition, the ability to prevent Ag adsorption and the ability to remove indium oxide film residue may be deteriorated.

If the content of the inorganic acid salt and the organic acid salt compound is more than 9% by weight based on the total weight of the composition, the action of phosphoric acid or nitric acid may be impaired and the etching rate may be excessively inhibited.

The inorganic acid salt compound of the inorganic acid salt or organic acid salt compound contained in the etchant of the present invention may be one or more of a salt of nitric acid, a salt of sulfuric acid and a salt of phosphoric acid. The organic acid salt compound may be acetic acid, , Malonic acid, malic acid, citric acid, tartaric acid, succinic acid, salicylic acid, sulfosalicylic acid, benzoic acid, lactic acid, glyceric acid, malic acid, Potassium salt, sodium salt or ammonium salt of tartaric acid and propenoic acid.

The water contained in the silver etching solution composition of the present invention uses deionized water for semiconductor processing, preferably water of 18 M? / Cm or more, and is contained in a balance such that the total weight of the composition is 100% by weight.

The silver etchant composition of the present invention can be used for a display (OLED, LCD, etc.) TFT array substrate, a TSP trace wiring, and a single film using silver or silver alloy, It can be used as structural etching solution. In addition to the above-mentioned display and TSP, it can be used for an electronic component material using a metal film such as a semiconductor.

Forming a single film made of silver or silver alloy on the substrate, or a multilayer film composed of the single film and the indium oxide film;

Selectively leaving a photoreactive material on the single layer of silver or silver alloy, or on the multi-layered film composed of the single layer and the indium oxide layer; And

And etching the multi-layered film composed of the single film made of silver or silver alloy, or the single film and the indium oxide film using the silver etching solution composition.

The present invention also provides a method of manufacturing a semiconductor device, comprising: forming a single film made of silver or silver alloy, or a multilayer film composed of the single film and the indium oxide film; And

Etching the multi-layered film composed of the single film made of silver or silver alloy, or the single film and the indium oxide film using the silver etchant composition described above.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

< Etchant  Composition Preparation>

Example  1 to 12 and Comparative Example  1 to 8

The ingredients shown in Table 1 below were mixed in the respective amounts to prepare silver etching composition.

[Table 1]

(Unit: wt%)

Experimental Example  1. Silver Etchant  Performance testing of the composition

An ITO / Ag / ITO triple layer was formed on the substrate on the substrate, and the unloading etching process was carried out using an injection type etching equipment (model name: ETCHER (TFT), manufactured by SEMES). The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were respectively put into the autoclave and the temperature was raised to 40 ° C. After the temperature reached 40 ± 0.1, the etching process of the ITO / Ag / ITO triplet was performed Respectively. The total etching time was 60 seconds. In the experiment, the initial use time (0 hour) was evaluated with the etchant composition, and after 12 and 24 hours after the evaluation, the same etchant composition was reevaluated.

1. Wiring loss measurement

The loss of wiring (or reflection film) was measured by one side etching distance (S / E, Side Etch) to measure wiring loss. The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were placed in an experimental equipment (model name: ETCHER (TFT), SEMES) of a spray-type etching system, the temperature was set to 40 ° C, When the temperature reached 40 ± 0.1 ° C, the etching process of the above specimens was carried out. When the etching time of the EPD standard over etch was reached, the substrates were taken out and rinsed with deionized water, And dried. After cleaning and drying, the substrate was cut and its cross-section was measured using an electron microscope (SEM; model: SU-8010, manufactured by Hitachi). As a standard for measuring the unilateral etching distance, the width of the inside of the photoresist was measured from the end of the photoresist. The results are shown in Table 2 below.

<Evaluation Criteria of Unilateral Etching Distance Measurement>

O: Good [S / E: less than 0.5 占 퐉]

X: poor [S / E: 0.5 탆 or more]

2. Silver adsorption

The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were placed in an experimental equipment (model name: ETCHER (TFT), SEMES) of a spray-type etching system, the temperature was set to 40 ° C, When the temperature reached 40 ± 0.1 ° C, the etching process of the above specimens was carried out. When the etching time of the EPD standard over etch was reached, the substrates were taken out and rinsed with deionized water, And dried. After cleaning and drying, the substrate was cut and the cross section was taken on the top surface of the specimen using an electron microscope (SEM; model: SU-8010, manufactured by Hitachi).

&Lt; Silver re-adsorption evaluation standard &

O: Good [less than 50]

X: Bad [more than 50]

3. Silver Residue Measurement measurement

The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were placed in an experimental equipment (model name: ETCHER (TFT), manufactured by SEMES) of a spray-type etching system, the temperature was set at 40 ° C, When the temperature reached 40 ± 0.1 ° C, the sample was etched and the substrate was injected. When the etching time of the EPD standard over etch was over, the substrate was taken out, washed with deionized water, , And the photoresist was removed using a photoresist stripper (PR stripper). After cleaning and drying, residual silver halide (Ag) was left unetched in a portion not covered with photoresist using an electron microscope (SEM; model name: SU-8010, manufactured by Hitachi) The results are shown in Table 2 below.

< Residue  Measurement evaluation criteria>

O: Good [no residue left]

X: Bad [Residual occurrence]

4. Indium oxide film (ITO) Residue  Measure

The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were placed in an experimental equipment (model name: ETCHER (TFT), manufactured by SEMES) of a spray-type etching system, the temperature was set at 40 ° C, When the temperature reached 40 +/- 0.1 DEG C, the etching process of the specimen was performed. The total etching time was 60 seconds.

After the substrate was injected and spraying was started, when the etching time of 60 seconds had elapsed, the substrate was taken out, washed with deionized water, dried using a hot air drier, and photoresist was removed using a photoresist stripper. After cleaning and drying, residues of ITO remaining unetched in a portion not covered with photoresist were measured using an electron microscope (SEM; model: SU-8010, manufactured by Hitachi), and the residue was evaluated according to the following criteria The results are shown in Table 2 below.

< Residue  Measurement evaluation criteria>

O: Good [no residue left]

X: Bad [Residual occurrence]

5. Etching  Straightness measurement of pattern

The silver etching compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were placed in an experimental equipment (model name: ETCHER (TFT), manufactured by SEMES) of a spray-type etching system, the temperature was set at 40 ° C, When the temperature reached 40 +/- 0.1 DEG C, the etching process of the specimen was performed. The total etching time was 60 seconds.

After the substrate was injected and spraying was started, when the etching time of 60 seconds had elapsed, the substrate was taken out, washed with deionized water, dried using a hot air drier, and photoresist was removed using a photoresist stripper. After cleaning and drying, residue remaining as a phenomenon in which TIO was not etched was measured at a portion where the photoresist was not covered using a scanning electron microscope (SEM; model: SU-8010, manufactured by Hitachi). The residue was evaluated according to the following criteria The results are shown in Table 2 below.

O: Good [Maximum S / E value of wiring - minimum S / E value less than 0.1 mu m]

X: bad [maximum S / E value of wiring - minimum S / E value of 0.1 탆 or more]

[Table 2]

 [Table 3]

From the above experimental results, it can be seen that the etchant composition of the present invention has excellent effects in all aspects of wiring loss, Ag re-adsorption, Ag residue, Ag residue, ITO residue, there was. In addition, it was confirmed that the etchant composition containing acetic acid (Comparative Example 8) had a problem of wiring loss.

Claims (8)

With respect to the total weight of the composition,
From 40 to 70% by weight of phosphoric acid;
2 to 9% by weight of nitric acid;
0.1 to 9% by weight of an organic acid not containing acetic acid;
0.1 to 9% by weight of an inorganic acid salt or organic acid salt compound; And
Wherein the total weight of the composition is 100% by weight.
The method of claim 1, wherein the organic acid is selected from the group consisting of citric acid, glycine, butanoic acid, isocitric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, sulphonic acid, salicylic acid, Glyceric acid, propenoic acid, and combinations thereof.
The method according to claim 1,
The inorganic acid salt compound is at least one selected from the group consisting of salts of nitric acid, salts of sulfuric acid, salts of phosphoric acid,
The organic acid salt compound may be at least one selected from the group consisting of acetic acid, iminodiacetic acid, ethylenediaminetetraacetic acid, butanoic acid, citric acid, isocitric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, Wherein the salt is at least one selected from the group consisting of salicylic acid, sulfosalicylic acid, benzoic acid, lactic acid, glyceric acid, malic acid, tartaric acid and propenoic acid in the form of potassium salt, sodium salt or ammonium salt.
The silver etching composition according to claim 1, wherein the silver etching composition is capable of simultaneously etching a single film made of silver or silver alloy, or a multilayer film composed of the single film and the indium oxide film.
[4] The method of claim 4, wherein the indium oxide is at least one selected from the group consisting of indium tin oxide (ITO), zinc oxide indium (IZO), zinc tin oxide indium (ITZO), and gallium indium gallium indium (IGZO) Wherein
[5] The method according to claim 4, wherein the multilayer film composed of the single film and the indium oxide film is at least one selected from the group consisting of indium oxide / silver, indium oxide / silver alloy, indium oxide / silver / indium oxide, indium oxide / silver alloy / &Lt; / RTI &gt;
Forming a single film made of silver or silver alloy on the substrate, or a multilayer film composed of the single film and the indium oxide film;
Selectively leaving a photoreactive material on the single layer of silver or silver alloy, or on the multi-layered film composed of the single layer and the indium oxide layer; And
Comprising the step of etching a single film made of silver or silver alloy using the composition of claim 1, or a multilayer film composed of said single film and an indium oxide film.
Forming a single film made of silver or silver alloy, or a multilayer film composed of the single film and the indium oxide film; And
A method of forming a metal pattern using the composition of claim 1, comprising etching a single film made of silver or silver alloy, or a multilayer film composed of said single film and an indium oxide film.