KR101453088B1 - Etchant composition and method for forming metal pattern using the same - Google Patents

Abstract

The present invention relates to a composition comprising 0.1 to 7% by weight of nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ) or a mixture thereof, From 0.5 to 20 wt.% _{(NH 4) 2 S 2 O} 8; And 73 to 99.4% by weight of water, and a method of forming a metal pattern using the same.

Copper, molybdenum, etchant

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etchant composition and a method for forming a metal pattern using the same,

The present invention relates to a wet etchant composition related to copper and molybdenum and to the formation of metal patterns using the same.

Generally, the process of forming a metal wiring on a substrate in a semiconductor device and a flat panel display device is usually performed by a metal film forming process by sputtering, a photoresist coating process, a photoresist forming process in an optional region by exposure and development, And includes a cleaning process before and after the individual unit process, and the like.

This etching process refers to a process of leaving a metal film in a selective region by using a photoresist mask. Dry etching using plasma or wet etching using an etching solution is usually used.

The copper-related film and the molybdenum-related film in the semiconductor device and the flat panel display device have been widely studied as wiring and are now being commercialized.

In addition, various etchant compositions have been proposed in order to form a copper-related film and a molybdenum power film using a wet etching method.

Initially, a mixture of phosphoric acid, nitric acid (HNO ₃ ), acetic acid, a chlorinated compound and a fluorinated compound was used depending on the constitution conditions of the thin film. However, when the copper-molybdenum film is etched using the mixed solutions, the etching speed of the copper located at the upper portion is too fast, so that the copper is over-deflected at the time when the molybdenum film located at the bottom is etched, . As a result, when the external driving voltage is applied, the resistance value inherent to copper can not be shown, which makes it difficult to apply to the process. In addition, the straightness of the wiring is not excellent in view of etching characteristics, and the taper angle is more than 90 degrees, which may cause problems in the subsequent process. Due to such a problem, there are many disadvantages in the practical process, and it is difficult to apply the mixed solutions to the copper-molybdenum film etching.

In addition, recently, the case of the mixed aqueous solution of the fruit has received much attention in the flat panel display. However, in the case of the above-mentioned hydrous mixed solution, the concentration changes with time, which causes a problem that affects the number of treatments, that is, the amount of the substrate to be etched. More specifically, in the case of an aqueous mixed solution, when copper is wet-etched, the etched copper is present in the fruit juice. When the amount of copper is saturated, the temperature rises rapidly when the copper reaches the apex. As a result, a large accident can be caused in the actual process, and the amount of the process is limited. In addition, in the case of an aqueous mixed solution, an auxiliary equipment is required when the process is carried out, which raises a problem that the manufacturing cost is increased

Accordingly, in order to solve such problems in this field, there is a need to develop a novel etching composition having no reaction with copper, which is a residue due to wet etching, and having excellent properties in etching.

In order to solve the problems of the prior art as described above, the present invention can etch a first single film including copper and a second single film including molybdenum respectively, and at the same time, It is an object of the present invention to provide an etchant composition and a method of forming a metal pattern using the etchant composition, which are capable of performing batch wet etching of multiple films including a single film, as well as excellent etching properties and stability.

In order to accomplish the above object, the present invention provides a method for producing an organic electroluminescent device, comprising: 0.1 to 7 wt% of nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), or a mixture thereof; 0.5 to 20% by weight of (NH ₄ ) ₂ S ₂ O and 73 to 99.4% by weight of water.

The present invention also provides a method of manufacturing a semiconductor device, comprising: forming a first metal film containing copper on a substrate, a second metal film containing molybdenum, and a plurality of these films;

And etching at least one of the first metal film, the second metal film, and the multiple film using the etching solution composition of the present invention.

The etchant composition of the present invention can etch a first monolayer comprising copper and a second monolayer comprising molybdenum respectively, and at the same time a batch etch of the multilayer including the first monolayer and the second monolayer It is possible. In addition, the stability of the chemical liquid is ensured in the process, side etching, residue generation and damage to the lower film are less and uniform etching characteristics are obtained. In addition, it can be applied to a large area substrate and provides excellent productivity because there is no damage to the equipment.

The invention compositions, based on the total weight, of 0.1 to 7% by weight of nitric acid (HNO _3), sulfuric acid (H ₂ SO _4), or mixtures thereof; 0.5 to 20% by weight of (NH ₄ ) ₂ S ₂ O and 73 to 99.4% by weight of water.

The nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), or a mixture thereof contained in the etchant composition of the present invention serves to oxidize copper and molybdenum. The nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), or a mixture thereof is preferably contained in an amount of 0.1 to 7% by weight based on the total weight of the composition. When the content of the nitric acid is less than 0.1% In the case of a double film comprising a first single film containing copper and a second single film containing molybdenum which can not obtain the desired etching characteristics due to the reduced etching rate or uneven etching, It is not etched. If it exceeds 7% by weight, excessive etching of copper occurs and peeling of the copper film occurs, which is not suitable for use in the process.

(NH ₄ ) ₂ S ₂ O ₈ contained in the etching solution composition of the present invention improves etching uniformity as a component for oxidizing copper. It also serves as an etch inhibitor of molybdenum to enable batch wet etching of the multiple films when etching multiple films comprising the first single film and the second single film.

The _{(NH 4) 2 S 2 O} 8 is, 0.5 to 20% by weight based on the total weight of the composition. (NH ₄ ) ₂ S ₂ O ₈ is contained in an amount of less than 0.5 wt%, the etching rate of copper is lowered or unevenness occurs due to uneven etching phenomenon, and when it exceeds 20 wt% Occurs.

The water contained in the etchant composition of the present invention is not particularly limited, but deionized water is preferred. More preferably, deionized water having a resistivity value of water of 18 M / cm or more (that is, the degree of removal of ions in water) is used. The water content is in the range of 73 to 99.4% by weight based on the total weight of the composition, and the content is the sum of water contained in the other components added in the form of an aqueous solution and water alone.

In addition to the above-mentioned components, conventional additives may further be added to the etchant composition of the present invention. Surfactants, sequestering agents, corrosion inhibitors, pH adjusters, and the like can be used as additives.

Surfactants decrease the surface tension and increase the uniformity of etching. As such a surfactant, a surfactant which is resistant to an etching solution and has compatibility with the surfactant is preferable. Examples thereof include any of anionic, cationic, amphoteric or nonionic surfactants and the like. Further, a fluorine-based surfactant can be used as a surfactant.

In addition, the additives are not limited thereto, and various other additives known in the art may be selected and added for better effect of the present invention.

The present invention also relates to

(a) forming one or more of a first metal film including copper on a substrate, a second metal film containing molybdenum, and a plurality of these films;

(b) etching the at least one of the first metal film, the second metal film and the multiple film using the etching solution composition of the present invention.

In the method of forming a metal pattern, the step (a) may include the steps of providing a substrate, and forming one or more of the first single film, the second single film, and the multiple film on the substrate . The substrate may be subjected to a conventional cleaning process, and a wafer, a glass substrate, a stainless steel substrate, a plastic substrate, or a quartz substrate may be used. As the method of forming the first monolayer, the second monolayer, and the multilayer on the substrate, various methods known to those skilled in the art can be used, and it is preferable to form the first monolayer, the second monolayer, and the multilayer using a vacuum evaporation method or a sputtering method.

The step (b) may include forming a photoresist on the first monolayer, the second monolayer, and the multilayer, selectively exposing the photoresist using a mask, and exposing the exposed photoresist after Baked, and the post-baked photoresist is developed to form a photoresist pattern. The first monolayer, the second monolayer, and the multilayer having the photoresist pattern formed thereon are etched using the etchant composition of the present invention to complete the metal pattern.

Such an etching process can be performed according to a method well known in the art, and examples thereof include a method of dipping, a method of spraying, and the like. During the etching process, the temperature of the etching solution may be in the range of 30 to 50 ° C., and the optimum temperature may be changed as necessary in consideration of other processes and other factors.

Here, the first monolayer, the second monolayer, and the multilayer thereof may be any one or more of a data line, a scan line, a gate electrode, and a source / drain electrode of a flat panel display device.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the scope of the present invention is not limited by the following examples and comparative examples.

Example  1 to 5 and Comparative Example 1 to  3: Etchant  Preparation of composition

The etchant compositions were prepared according to the ingredients and composition ratios shown in Table 1 below.

HNO ₃
(weight%) H ₂ SO ₄
(weight%) (NH4) ₂ S ₂ O ₈
(weight%) water
(weight%) Example 1 3.0 0.5 10 86.5 Example 2 3.0 1.1 10 85.9 Example 3 2.0 1.0 16 81.0 Example 4 1.5 0.1 15 83.4 Example 5 1.0 1.0 15 83.0 Comparative Example 1 0.3 6.0 0.1 93.6 Comparative Example 2 10.0 0.3 15 74.7 Comparative Example 3 3.0 0.5 30 66.5

Test Example : Etch characteristics  evaluation

The etching solution of Examples 1 to 5 and Comparative Examples 1 to 3 was put into an experimental apparatus (manufactured by SEMES) of a substrate on which a Cu single layer and a Cu / Mo double layer were deposited on a substrate, respectively, After heating, the etching process was performed when the temperature reached 30 ± 0.1 ° C. The total etch time was set to 40% over etch based on EPD (End Point Detection). After the substrate was injected and the etching was completed, the substrate was taken out, washed with deionized water, dried using a hot air dryer, and photoresist was removed using a photoresist stripper. After washing and drying, Side Etch loss, bottom film damage and etching residue were evaluated using an electron microscope (SEM; model: S-4700, manufactured by HITACHI Corporation)

Types of Thin Films Etch characteristics results Types of Thin Films Etch characteristics results EPD
(sec) S / E
(탆) Residue EPD
(sec) S / E
(탆) Residue Example 1 Cu 35 0.22 X Cu / Mo 52 0.50 X Example 2 32 0.25 X 51 0.47 X Example 3 31 0.32 X 42 0.55 X Example 4 30 0.29 X 46 0.41 X Example 5 42 0.39 X 59 0.51 X Comparative Example 1 Not etched Not etched Comparative Example 2 12 2.7 X 16 3.5 X Comparative Example 3 6 2.5 X Pattern Loss X

Referring to Table 2, etching the Cu mono film and the Cu / Mo bilayer using the etching solution compositions of Examples 1 to 5 according to the present invention provides very good etching in terms of side etching loss and etch residue. And the etching characteristics are shown. As in the case of Comparative Example 1, when (NH ₄ ) ₂ S ₂ O ₈ is less than the content range defined in the present invention, there arises a problem that copper is not etched. As in the case of Comparative Example 2, when the mixture of HNO ₃ and H ₂ SO ₄ exceeds the content range defined in the present invention, the side etching loss becomes large. Also, as in the case of Comparative Example 3, when the content of (NH ₄ ) ₂ S ₂ O ₈ exceeds the content range defined in the present invention, the etching rate is greatly increased and the wiring is lost due to the overeating angle.

FIG. 1B is a SEM photograph of a substrate on which a Cu single layer is deposited by the etchant composition of Example 4, FIG. 1B is a cross-sectional view of a substrate on which a Cu single layer is deposited by etching the etchant composition of Example 4, Is an SEM photograph after peeling.

Referring to FIGS. 1A and 1B, when the etchant composition according to an embodiment of the present invention is used, it can be confirmed that the pattern of copper is excellent and the damage of the bottom film does not occur.

FIG. 2A is a SEM photograph of a substrate on which a Cu / Mo double film is deposited by the etching composition of Example 4, FIG. 2B is a SEM image after etching a substrate on which a Cu / Mo double film is deposited using the etching composition of Example 4 , And SEM photographs after peeling off the photoresist.

Referring to FIGS. 2A and 2B, it can be seen that the galvanic phenomenon does not occur in the Cu / Mo bilayer, so that the pattern profile is excellent and the lower film damage does not occur.

FIG. 1A is an SEM photograph of a substrate on which a Cu single layer is deposited using the etchant composition of Example 4. FIG.

FIG. 1B is an SEM photograph of a substrate on which a Cu single layer is deposited by etching using the etchant composition of Example 4, and then removing the photoresist. FIG.

2A is an SEM photograph of a substrate on which a Cu / Mo double film is deposited using the etchant composition of Example 4. FIG.

FIG. 2B is a SEM photograph of a substrate on which a Cu / Mo double film is deposited using the etchant composition of Example 4, and the photoresist is peeled off.

Claims (7)

The composition of the total mixture, by weight based on the weight, of 0.1 to 7% by weight of nitric acid (HNO ₃₎ and sulfuric acid (H ₂ SO _4); Of 10 to 20% _{(NH 4) 2 S 2 O} 8; And 73 to 89.9% by weight of water. A single film comprising copper, a single film comprising molybdenum, and a single film comprising copper and a single film comprising molybdenum. Etchant composition for a film. The method of claim 1, wherein the water is deionized water. The method of claim 1, wherein the water is deionized water, wherein the water comprises a single membrane comprising copper, a single membrane comprising molybdenum and a single membrane comprising copper and a single membrane comprising molybdenum Etchant composition for a film. The etchant composition of claim 1, wherein the etchant composition further comprises at least one additive selected from an etch control agent, a surfactant, a sequestering agent, a corrosion inhibitor, and a pH adjuster. A single film comprising silicon, a single film comprising silicon, and a single film comprising molybdenum. Forming one or more of a first monolayer comprising copper on the substrate, a second monolayer comprising molybdenum and multilayers thereof; And etching at least one of the first monolayer, the second monolayer, and the multilayer using the etching liquid composition of any one of claims 1 to 3. 5. The method of claim 4, wherein the first monolayer, the second monolayer, and the multilayer are formed using a vacuum evaporation method or a sputtering method. 5. The method of forming a metal pattern according to claim 4, wherein a photoresist pattern is formed on any one of the first single film, the second single film and the multiple film. [6] The method of claim 4, wherein in the etching step, the multiple layers are etched in a batch.

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