KR20190084918A - Method for forming metal line - Google Patents

Abstract

The present invention relates to a method of forming a wiring of a copper metal film by using an etching liquid composition which etches only the copper metal film on the upper side while minimizing the attack on the metal oxide film on the lower side, in a double film composed of the metal oxide film and the copper metal film; and to the etching liquid composition of the copper metal film.

Description

[0001] METHOD FOR FORMING METAL LINE [0002]

The present invention relates to an etching solution composition of a copper-based metal film and a method of forming a wiring of a copper-based metal film using the etching solution composition.

The process of forming a metal wiring on a substrate in a liquid crystal display device is usually composed of a metal film forming process by sputtering or the like, a photoresist coating process, a photoresist forming process in an optional region by exposure and development, and a step by an etching process And a cleaning process before and after the individual unit process. This etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask. Typically, dry etching using plasma or wet etching using an etching composition is used.

Various wirings have been proposed according to the driving method and resolution to be implemented. A gate and a source / drain wiring using a lamination film of a molybdenum-based metal film and an aluminum-based metal film are most commonly used; a wiring using copper as the conductive film and a wiring using molybdenum or titanium as the barrier metal; and the like. In addition, in the FFS (Fringe Field Switching) mode or the partial transverse electric field system, a wiring for a multilayer film of copper and a metal oxide film (for example, an indium oxide film) is also used. However, in the case of the multilayer film, only the upper copper film is etched A multilayer film may be formed. However, there is no development of etchant for this.

Korean Patent Publication No. 2005-0067934 discloses an etchant for collectively etching a copper metal layer containing nitric acid, hydrochloric acid, hydrogen peroxide and an azole compound and a transparent conductive layer. However, the above-mentioned patent has a problem that not only the upper copper film but also the indium oxide film as the lower film is etched.

KR 10-2005-0067934 A (2005.07.05)

It is an object of the present invention to minimize the attack of a metal oxide film when a multi-layered metal layer made of a metal oxide film and a copper-based metal film is wet-etched and to form a taper profile having an excellent direct- And the residue of the metal film is not left after the etching.

It is another object of the present invention to provide a method for forming a wiring of a copper-based metal film using the etchant composition.

The present invention relates to a composition comprising: A) from 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); B) from 0.1 to 5% by weight of an azole compound, C) from 3 to 15% by weight of a phosphonic acid derivative and its salt; And D) the remaining amount of water.

The present invention also relates to a method for manufacturing a semiconductor device, comprising: (I) forming a metal oxide film on a substrate; II) forming a copper-based metal film on the metal oxide film; III) selectively leaving a photoreactive material on the copper-based metal film; And (IV) etching the upper copper-based metal film using the etchant composition of the present invention.

The etchant composition of the present invention is excellent in etching uniformity and straightness without etching the underlying metal oxide film when etching the copper-based metal film on the upper one of the double films made of the metal oxide film and the copper-based metal film Taper profile, and does not generate residues, so that it does not cause problems such as electrical shorts, poor wiring, and reduced luminance.

Therefore, the etchant composition of the present invention can be very usefully used in manufacturing an array substrate for a liquid crystal display device in which a circuit of a large screen and a high luminance is realized.

1 is a SEM photograph of a profile section of a copper-based metal film etched with the etchant composition according to Example 4. FIG.

Hereinafter, the present invention will be described more specifically.

A) from 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ), B) from 0.1 to 5% by weight of an azole compound, C) from 3 to 15% by weight of a phosphonic acid derivative or salt thereof; And D) the remaining amount of water.

In the present invention, the copper-based metal film includes copper as a constituent component of the film, and the copper-based metal film means pure copper, a nitride of copper, an oxide of copper, or an alloy of copper.

The copper alloy may be one selected from the group consisting of pure copper, a nitride of copper, and an oxide of copper, and at least one selected from the group consisting of aluminum (Al), magnesium (Mg), calcium (Ca), titanium (Ti) (Hf), tantalum (Ta), and tungsten (W), which is a group consisting of Cr, Cr, Mn, Fe, Zr, Nb, Mo, Pd, ≪ RTI ID = 0.0 > and / or < / RTI >

In the present invention, the etchant composition of the copper-based metal film refers to an etchant composition that etches only copper as the upper layer while minimizing the attack of the metal oxide film as a lower layer in the double-layered film made of the copper-based metal film and the metal oxide film.

In the present invention, the 'metal oxide film' generally has a composition of AxByCzO (where A, B and C are zinc, cadmium, gallium, indium, tin, hafnium, (Zr) and tantalum (Ta), and combinations of x, y, and z? 0, the oxide semiconductor layer being referred to as an oxide semiconductor layer Or a film constituting the oxide semiconductor layer.

The A) hydrogen peroxide contained in the etchant composition of the present invention is a main component for etching the copper-based metal film, and the content thereof is preferably 5 to 25 wt%, more preferably 15 to 23 wt% .

If the hydrogen peroxide is contained in an amount of less than 5% by weight based on the total weight of the composition, the etching rate is very slow. If the hydrogen peroxide is more than 25% by weight, the etching rate is accelerated.

The B) azole compound contained in the etchant composition of the present invention controls the etch rate of the copper-based metal and reduces the CD loss of the pattern, thereby enhancing the process margin. The content of the azole compound is preferably 0.1 to 5 wt%, more preferably 0.5 to 1.5 wt% based on the total weight of the composition. If the content of the azole compound is less than 0.1 wt%, the etch rate may become too high and the seed loss may be too large. If the content of the azole compound is more than 5 wt%, the etching rate of copper may become too slow, Can be.

The azole compounds include, for example, aminotetrazole, benzotriazole, tolyltriazole, pyrazole, pyrrole, imidazole, 2-methyl And one kind selected from the group consisting of 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-aminoimidazole, Or two or more of them may be used together, but the present invention is not limited thereto.

The C) phosphonic acid derivatives and salts thereof inhibit the decomposition reaction of hydrogen peroxide by chelating the copper ions dissolved in the etching solution by etching the copper film to inhibit the activity of the copper ions. If the activity of the copper ion is lowered as described above, the process can be stably performed while using the etching solution. The phosphonic acid derivatives and salts thereof are preferably contained in an amount of 3 to 15% by weight, more preferably 5 to 10% by weight based on the total weight of the composition.

When the content of the phosphonic acid derivative and its salt is less than 3% by weight based on the total weight of the composition, the etching uniformity is lowered and the decomposition of hydrogen peroxide is accelerated, and the treatment capacity is not large. If the content of the phosphonic acid derivative or its salt is more than 15.0% by weight based on the total weight of the composition, the etching rate of the copper film becomes too high, which makes process control difficult. Also, .

The phosphonic acid derivatives and salts thereof may be any of those conventionally used in the art. For example, 2-aminoethylphosphonic acid (2-AEP), dimethyl methylphosphonate (DMMP) (1-hydroxyethylidene-1,1-diphosphonic acid, HEDP), aminotris (methylene phosphonic acid) (ATMP) (Ethylenediamine tetra (methylene phosphonic acid), EDTMP), tetraethylene diamine tetra (methylene phosphonic acid), TDTMP, hexamethylenediamine tetra (methylene phosphonic acid ), Hexamethylenediamine tetra (methylene phosphonic acid), HDTMP), diethylenetriamine penta (methylene phosphonic acid), DTPMP), phosphonobutane-tricarboxylic acid (Pho phosphonomethyl iminodiacetic acid (PMIDA), 2-carboxyethyl phosphonic acid (CEPA), 2-hydroxy-2-hydroxybenzoic acid 2-Hydroxyphosphonocarboxylic acid (HPAA) and Amino-tris- (methylene-phosphonic acid) (AMP); And a salt thereof, and it is preferable that the salt is a sodium salt or a potassium salt. More preferably, the phosphonic acid derivative salt may be a sodium salt or potassium salt of 1-hydroxyethylidene-1,1-diphosphonic acid.

The D) 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 specific resistance value of water (that is, a degree of removal of ions in water) of 18 M OMEGA. Or more can be used. The water content is such that the total weight of the etchant composition of the present invention is 100% by weight.

In addition, the etchant composition may further comprise a surfactant. The surfactant serves to lower the surface tension and increase the uniformity of the etching. The surfactant is not particularly limited as long as it can withstand the etching composition of the present invention and is compatible with the surfactant. However, the surfactant may be an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and a polyhydric alcohol surfactant , Or a combination thereof.

In addition to the above-described components, conventional additives may be further added. Examples of the additive include a metal ion blocking agent and a corrosion inhibitor.

In the present invention, A) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ), B) 0.1 to 5% by weight of an azole compound, C) 3 to 15% by weight of a phosphonic acid derivative and its salt; And D) the remaining amount of water can be manufactured by a conventionally known method, and preferably has a purity for semiconductor processing.

According to the present invention,

I) forming a metal oxide film on the substrate;

II) forming a copper-based metal film on the metal oxide film;

III) selectively leaving a photoreactive material on the copper-based metal film; And

IV) etching the copper-based metal film on the upper portion using the etchant composition of the present invention.

In the wiring forming method of the present invention, the photoreactive material is preferably a conventional photoresist material, and can be selectively left by a conventional exposure and development process.

In the present invention, the copper-based metal film includes copper as a constituent component of the film, and the copper means pure copper or an alloy of copper.

Wherein the copper-based metal film comprises one selected from the group consisting of pure copper, a nitride of copper, and an oxide of copper, or one selected from the group consisting of pure copper, a nitride of copper, and an oxide of copper, aluminum (Al) (Mg), Ca (Ca), Ti (Ti), Ag, Cr, Mn, Refers to an alloy of at least one metal selected from the group consisting of palladium (Pd), hafnium (Hf), tantalum (Ta), and tungsten (W).

The metal oxide film is usually made of a material selected from the group consisting of AxByCzO (where A, B and C are zinc, cadmium, gallium, indium, tin, hafnium, zirconium, (Ta), and combinations of x, y, and z? 0, wherein the film is formed of an oxide semiconductor layer or an oxide semiconductor layer It can be a membrane to constitute.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Examples 1 to 7 and Comparative Examples 1 to 3: Preparation of etching compositions

The etchant compositions of Examples 1 to 7 and Comparative Examples 1 to 3 were prepared according to the compositions and contents shown in Table 1 below.

Unit: wt% Hydrogen peroxide (H ₂ O ₂ ) Aminotetrazole 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) Deionized water Example 1 5 0.2 3.0 Balance Example 2 10 0.5 5.0 Balance Example 3 15 0.8 7.0 Balance Example 4 18 1.0 10.0 Balance Example 5 22 1.5 12.0 Balance Example 6 25 3.0 15.0 Balance Example 7 20 1.5 10.0 Balance Comparative Example 1 15 0.8 - Balance Comparative Example 2 15 0.8 1.0 Balance Comparative Example 3 15 0.8 18.0 Balance

Test Example 1: Evaluation of characteristics of the etching liquid composition

After depositing a metal oxide film on a glass substrate (100 mm x 100 mm) and depositing a copper film on the film, a photoresist having a predetermined pattern was formed on the substrate through a photolithography process, The copper-based metal films (Cu / ITO double films and Cu / IGZOx double films) were etched using the compositions of Comparative Examples 1 to 3, respectively. (ETCHER (TFT), manufactured by SEMES) was used as the etchant, and the temperature of the etchant composition was set at about 30 ° 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 is usually about 100 seconds. The profile of the copper-based metal film etched in the etching process was examined using a cross-sectional SEM (product of Hitachi, model name: S-4700).

After the etching process was performed using the etching solution compositions of Examples 1 to 7 and Comparative Examples 1 to 3 as described above, the etching profile, the etching straightness, the metal oxide film attack, the presence / absence of residue And the results are shown in Table 2 below.

Further, in order to evaluate the degree of overheat due to a chain decomposition reaction of hydrogen peroxide in the presence of a metal ion (in particular, copper ion), in the etching solutions corresponding to Examples 1 to 7 and Comparative Examples 1 to 3, After the Cu powder was eluted, And the temperature was measured. The results are shown in Table 2 below. At this time, the maximum temperature in Table 2 is the highest value of the temperature change of the etchant due to the hydrogen peroxide chain decomposition reaction at the elution of 3000 ppm of Cu.

Etch characteristics Residual occurrence Metal oxide film attack Temperature change due to Cu 3000ppm dissolution (℃) Initial temperature Maximum temperature Example 1 ○ none None (ITO film) 30.1 34.2 Example 2 ○ none None (ITO film) 30.6 33.1 Example 3 ○ none None (ITO film) 30.1 33.0 Example 4 ○ none None (ITO film) 30.2 32.4 Example 5 ○ none None (ITO film) 30.1 32.6 Example 6 ○ none None (ITO film) 30.0 32.1 Example 7 ○ none None (IGZOx) 29.9 32.5 Comparative Example 1 Cu Unetch - - Does not melt Does not melt Comparative Example 2 ○ none None (ITO film) 44.5 99.7 Comparative Example 3 X none None (ITO film) 30.3 31.7 * Etch characteristics
○: Good linearity and excellent taper profile when etching
△: Forms excellent taper profile at etching but not good linearity
Ⅹ: Taper profile and straightness due to deformation of interfacial profile at etching is not good at all

As shown in Table 2 above, the etching solutions of Examples 1 to 7 all exhibited good etching properties and did not attack the underlying metal oxide film of the copper layer. As can be seen from FIG. 1, when the copper-based metal film was etched with the etchant composition of Example 4, a satisfactory taper profile was exhibited, and the etching straightness was excellent. The etching residue and the metal oxide film attack phenomenon There was no.

In addition, as shown in Table 2, in the case of the etching solutions of Examples 1 to 7, it was shown that even when 3000 ppm of Cu was released, the temperature rose only up to 34.2 ° C, and the superheat stability characteristics were greatly improved. On the other hand, the etchant of Comparative Example 1, which did not contain 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), exhibited Cu unetch phenomenon, HEDP is essential for etching. On the other hand, when the copper-based metal film was etched with the etchant composition according to Comparative Example 2, a satisfactory taper profile was exhibited, but overheat stability could not be ensured upon elution of 3000 ppm of Cu. In addition, when the copper-based metal foil was etched with the etchant composition according to Comparative Example 3, the etch characteristics were not good due to a too high etch rate, but it was confirmed that the overheat stability was secured.

Test Example 2: Evaluation of the number of treatments of the etching composition according to the Cu concentration

Cu powder was sequentially eluted to the Cu concentration (0 to 7000 ppm) shown in Table 3 in the etchant composition of Example 3 according to the present invention to evaluate etchability and stability of the etchant composition.

Therefore, evaluation was made with respect to changes in temperature depending on the Cu concentration, presence / absence of residue, etching profile, etching straightness, presence / absence of metal oxide film attack, etc., and the results are shown in Table 3. The maximum temperature in Table 3 below represents the highest temperature change of the etchant due to the hydrogen peroxide chain decomposition reaction as the Cu concentration increases. In this evaluation, it was determined that the etchant composition can be continuously used in the etching process in the case where the superheat stability is secured and the etching conditions are satisfied while the residue is not generated.

Cu elution amount (ppm) Maximum temperature Etch characteristics Residual occurrence Presence or absence of metal oxide film 0 30.1 O radish radish 100 30.2 O radish radish 500 30.6 O radish radish 1000 31.1 O radish radish 2000 32.1 O radish radish 3000 32.5 O radish radish 4000 33.1 O radish radish 5000 33.5 O radish radish 6000 34.1 O radish radish 7000 35.4 △ radish radish * Etch characteristics
○: Good linearity and excellent taper profile when etching
△: Forms excellent taper profile at etching but not good linearity
Ⅹ: Taper profile and straightness due to deformation of interfacial profile at etching is not good at all

As shown in Table 3, the etching solution of Example 3 did not cause an overheating phenomenon even when Cu was released for 7000 ppm, did not cause residue and metal oxide film attack, and had an etching profile and straightness Lt; / RTI > Therefore, it was confirmed that the etching composition of Example 3 was usable until 7000 ppm of Cu was eluted.

Claims (8)

I) forming a metal oxide film on the substrate;
II) forming a copper-based metal film on the metal oxide film;
III) selectively leaving a photoreactive material on the copper-based metal film; And
IV) etching the copper-based metal film on the upper portion using the etchant composition,
Wherein the etchant composition comprises A) from 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ), B) from 0.1 to 5% by weight of an azole compound, C) from 3 to 15% by weight of a phosphonic acid derivative or salt thereof and D ) ≪ / RTI > residual water. The metal oxide film according to claim 1, wherein the metal oxide film is formed of a material selected from the group consisting of AxByCzO (where A, B and C are zinc, cadmium, gallium, indium, tin, hafnium, (Zr) and tantalum (Ta), and combinations of x, y, and z? 0). The copper-based metal film according to claim 1, wherein the copper-based metal film comprises one selected from the group consisting of pure copper, a nitride of copper, and an oxide of copper, or one selected from the group consisting of pure copper, a nitride of copper, (Al), magnesium, calcium, titanium, silver, chromium, manganese, iron, zirconium, niobium, molybdenum, Is an alloy of at least one metal selected from the group consisting of molybdenum (Mo), palladium (Pd), hafnium (Hf), tantalum (Ta) and tungsten (W). With respect to the total weight of the composition,
A) 5 to 25% by weight hydrogen peroxide (H ₂ O ₂ );
B) from 0.1 to 5% by weight of an azole compound;
C) from 3 to 15% by weight of phosphonic acid derivatives and salts thereof; And
D) water of the copper-based metal film. The method of claim 4, wherein the azole compound is selected from the group consisting of aminotetrazole, benzotriazole, tolyltriazole, pyrazole, pyrrole, imidazole, Is one or more compounds selected from the group consisting of 2-ethylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-aminoimidazole, 4-methylimidazole, Wherein the copper-based metal film is a mixture of two or more copper-based metal films. The phosphonic acid derivative or salt thereof according to claim 4, wherein the phosphonic acid derivative and its salt are selected from the group consisting of 2-aminoethylphosphonic acid (2-AEP), dimethylmethylphosphonate (DMMP), 1-hydroxyethylidene-1,1-diphosphonic acid ), Aminotris (methylenephosphonic acid) (ATMP), ethylenediaminetetra (methylenephosphonic acid) (EDTMP), tetraethylene diamine tetra (methylenephosphonic acid) (TDTMP), hexamethylenediamine tetra ), Diethylenetriaminepenta (methylenephosphonic acid) (DTPMP), phosphonobutane-tricarboxylic acid (PBTC), N- (phosphonomethyl) iminodiacetic acid (PMIDA), 2-carboxyethylphosphonic acid ) And 2-hydroxyphosphonocarboxylic acid (HPAA), amino-tris- (methylene-phosphonic acid) (AMP); And a salt thereof, wherein the copper-based metal film is one or a mixture of two or more thereof . 5. The etchant composition of claim 4, wherein the etchant composition further comprises a surfactant. [6] The method of claim 4, wherein the copper-based metal film comprises one selected from the group consisting of pure copper, a nitride of copper, and an oxide of copper, or one selected from the group consisting of pure copper, a nitride of copper, (Al), magnesium, calcium, titanium, silver, chromium, manganese, iron, zirconium, niobium, molybdenum, Is an alloy of at least one metal selected from the group consisting of molybdenum (Mo), palladium (Pd), hafnium (Hf), tantalum (Ta) and tungsten (W).

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