KR20100001623A - Etching solution composition - Google Patents

Abstract

PURPOSE: An etching solution composition is provided to implement uniform etching by increasing a etch rate without damage to lower film and equipment. CONSTITUTION: In a device, an etchant composites comprises includes H2O2 of 5-30wt%, fluorine containing of 0.1-2wt%, a compound containing the NH4+ salt of 0.55wt%, water. H2O2 oxidizes the surface of an aluminum layer and a titanium layer. A perfluorinated compound etches the oxidized surface of the aluminum layer and the titanium layer. The compound including the NH4+ salt controls the etching of the titanium layer and aluminum layer. The perfluorinated compound is dissociated into fluorine ion and a multi-element fluorine ion.

Description

Etch solution composition {ETCHING SOLUTION COMPOSITION}

According to an aspect of the present invention, an etching liquid composition capable of collectively wet-etching a single layer composed of titanium or a titanium alloy, aluminum or an aluminum alloy used in a gate, a source / drain electrode, and a multilayer of two or more layers including the metal in the configuration of a flat panel display device It is about.

In the liquid crystal display, the process of forming the metal wiring on the substrate is generally composed of a metal film forming process by sputtering, a photoresist forming process in a selective region by photoresist coating, exposure and development, and an etching process. do. Moreover, the washing | cleaning process, etc. before and after an individual unit process are included. The etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask, and typically, a dry etching using a plasma or the like and a wet etching using an etching solution are used.

In the construction of the liquid crystal display device, the metal layer uses aluminum having low resistance as the conductive layer. The aluminum layer is insulated by contact with the oxide layer and short-circuit with the other conductive layer by hillock in a subsequent process. There is a problem to form. Thus, as the insulating layer, molybdenum (Mo), titanium (Ti), chromium (Cr), and alloys containing these as main components are used. Recently, titanium having corrosion resistance, robustness, and high strength has been spotlighted. .

An electrode in which a titanium layer is used as an insulating layer was conventionally etched using a halogen gas in a dry etching process. However, despite the advantages of having an anisotropic profile and superior etching control compared to the wet etching process, it is difficult to construct expensive equipment and large area, and there is a problem that productivity is lowered because the etching speed is slow.

Accordingly, Korean Patent Application Nos. 10-1999-0005010, 10-1999-0043017, and the like disclose that HF is used as one component of an etchant composition for wet etching a titanium layer.

However, when HF is used for wet etching, a lot of constraints are placed on the process conditions due to damage to the underlying film and the equipment, which causes a decrease in productivity.

It is an object of the present invention to provide an etchant composition capable of collectively wet etching a single film composed of titanium or a titanium alloy, aluminum or an aluminum alloy, and multiple or more double films comprising the metal. In addition, the etching speed is fast, there is no damage to the lower layer and the equipment, expensive equipment configuration is not required, it is advantageous to large area, and to provide an etching liquid composition having excellent productivity by having a uniform etching characteristics.

In order to achieve the above object, the present invention, based on the total weight of the composition, H ₂ O ₂ 5-30% by weight; 0.1 to 2 wt% of a fluorine-containing compound; 0.5 to 5 weight percent of a compound comprising an NH ₄ ⁺ salt; And it provides an etching liquid composition comprising a residual amount of water.

The etchant composition of the present invention may batch wet etch a single layer composed of titanium or a titanium alloy, aluminum or an aluminum alloy, and multiple layers of a double layer or more including the metal. In addition, the etching speed is fast, there is no damage to the bottom film and equipment, and expensive equipment configuration is not necessary. In addition, it is advantageous for large area, has uniform etching characteristics and excellent productivity.

Hereinafter, the present invention will be described in detail.

The etchant composition of the present invention contains H ₂ O ₂ , a fluorine-containing compound, a compound including NH ₄ ⁺ salt and water.

H ₂ O ₂ contained in the etchant composition of the present invention serves to oxidize the surface of titanium and aluminum. The H ₂ O ₂ is preferably contained in 5 to 30% by weight based on the total weight of the composition. When the above-mentioned range is satisfied, the titanium oxide and the aluminum layer are prevented from decreasing the etch rate, so that a proper amount is etched, and the etching profile is excellent. Outside the above range, overetching of the titanium layer and the aluminum layer occurs, resulting in loss of pattern and loss of function as metal wiring.

The fluorine-containing compound contained in the etchant composition of the present invention serves to etch the surface of the oxidized titanium and aluminum. The fluorine-containing compound is preferably contained in 0.1 to 2% by weight based on the total weight of the composition. If the above-mentioned range is satisfied, the upper and lower titanium and aluminum layers are etched at an appropriate speed to implement uniform etching characteristics and prevent residue. Outside the above-described range, uneven etching characteristics may cause stains in the substrate, damage of the lower layer may occur due to excessive etching speed, and the etching rate may be difficult to control during the process. The fluorine-containing compound is preferably a compound capable of dissociating into fluorine ions or polyatomic fluorine ions. The compound that can be dissociated into fluorine ions or polyatomic fluorine ions is preferably one or two or more selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium bifluoride, and potassium bifluoride.

Compound containing NH ₄ ⁺ salt contained in the etchant composition of the present invention serves as an etch inhibitor for the aluminum layer and serves as a regulator for improving the etching uniformity for the titanium layer. The compound containing the NH ₄ ⁺ salt is preferably contained in 0.5 to 5% by weight based on the total weight of the composition. If the above range is satisfied, the etching uniformity is excellent. Outside the above-described range, the etching uniformity may be lowered to cause an etching difference in the substrate, thereby causing staining. In addition, it may cause an uneven etching characteristic in which the etching of the aluminum layer and the tip d occurs in the titanium layer. The compound containing the NH ₄ ⁺ salt is CH ₃ COONH ₄ , NH ₄ NO ₃ , (NH ₄ ) ₂ SO ₄ NH ₄ C ₆ H ₅ O ₂ , (NH ₄ ) ₂ S ₂ O ₈ NH ₄ Cl, NH ₄ H ₂ PO ₄ , NH ₄ OOCH, NH ₄ HCO ₃ , H ₄ NO ₂ CCH ₂ C (OH) (CO ₂ NH ₄ ) CH ₂ CO ₂ NH ₄ , NH ₄ PF ₆ , HOC (CO ₂ H) ( _{CH 2 CO 2 NH 4) 2} , and H ₂ NSO ₃ is preferably NH or greater one or two or _four selected from the group consisting of.

The water contained in the etchant composition of the present invention means deionized water and is used for the semiconductor process, and preferably water of 18 μs / cm or more is used.

The etchant composition of the present invention may contain one or two or more selected from the group consisting of an etch regulator, a surfactant, a metal ion sequestrant, a corrosion inhibitor and a pH regulator in addition to the above-mentioned components.

The etchant composition of the present invention is an etchant capable of collectively etching a single film made of titanium or a titanium alloy, aluminum or an aluminum alloy, and a multilayer film of a bilayer or more including the metal. Here, the multilayer film includes a double film in which a titanium or titanium alloy film is laminated on or under an aluminum or aluminum alloy film, and for example, a titanium or titanium alloy film and a triple metal or more of a triple film in which an aluminum or aluminum alloy film is alternately stacked. The concept also includes the case of acts. In particular, the etchant composition of the present invention, the upper layer is titanium or titanium alloy film; The intermediate layer is aluminum or an aluminum alloy film; The lower layer can be preferably used in a triple film made of titanium or titanium alloy film. The titanium or titanium alloy film is a concept including a metal film made of an alloy using titanium as a main component and another metal according to the properties of the titanium film or the film. The aluminum or aluminum alloy film is a concept including a metal film made of an alloy using aluminum as a main component and another metal depending on the characteristics of the aluminum film or the film.

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

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

To the etchant composition according to the component and composition ratio shown in Table 1 to 180kg was prepared.

H ₂ O ₂ (% by weight) Fluorine-containing compound (% by weight) Compound containing NH4 ⁺ salt (% by weight) Water (wt%) HF NH ₄ FHF Sum NH ₄ NO ₃ CH ₃ COONH ₄ Sum Example 1 20 0.5 0.5 1.0 2 One 3 Remaining amount Example 2 17 0.2 1.0 1.2 One One 2 Remaining amount Example 3 15 0.2 1.0 1.2 One 0.5 1.5 Remaining amount Example 4 15 0.1 0.5 0.6 0.5 0.5 1.0 Remaining amount Example 5 10 0.3 1.0 1.3 0.5 0.5 1.0 Remaining amount Example 6 15 0 1.0 One One 0 1.0 Remaining amount Example 7 20 0.3 0 0.3 2 0.5 2.5 Remaining amount Example 8 25 0 0.7 0.7 0.5 0.5 1.0 Remaining amount Comparative Example 1 15 0.5 2.0 2.5 0 2 2.0 Remaining amount Comparative Example 2 20 0.3 1.0 1.3 2 7 9.0 Remaining amount Comparative Example 3 4 0.1 0.5 0.6 3 3 6.0 Remaining amount Comparative Example 4 0 0.2 1.0 1.2 One 0.5 1.5 Remaining amount

Test Example : Etching  Property evaluation

SiNx layer is deposited on glass, Ti / Al / Ti triple layer is stacked on SiNx layer, and photoresist patterned substrate is cut into 550 × 650mm using diamond knife on the triple layer. Prepared.

The etching liquid prepared in Examples and Comparative Examples was placed in an experimental equipment of a spray etching method (manufactured by SEMES, model name: ETCHER (TFT)), and warmed by setting the temperature to 25 ° C. Thereafter, after the temperature reached 25 ± 0.1 ℃, the etching process was performed. Total etch time was given at 40% based on EPD. Insert the specimen, start spraying, and when the etching is complete, taken out, washed with deionized water, dried using a hot air drying apparatus, and removed the photoresist using a photoresist stripper (PR) stripper. After cleaning and drying, an electron scanning microscope (SEM; manufactured by HITACHI, model name: S-4700) was used to evaluate the inclination angle, side etching, critical dimension (CD), etching residue and underlying film damage of the etching profile. The results are shown in Table 2.

[Evaluation Criteria of Etch Profile]

◎: very good (CD Skew: ≤1 μm, taper angle: 40 ° to 90 °

○: Excellent (CD Skew: ≤1.5 µm, Taper angle: 40 ° to 90 °

(Triangle | delta): Good (CD skew: ≤2 micrometer, taper angle: 40 degrees-90 degrees)

×: defective (pattern loss and residue)

Type of thin film Etch profile Lower membrane damage Residue Example 1 Ti / Al / Ti ◎ none none Example 2 ◎ none none Example 3 ◎ none none Example 4 ◎ none none Example 5 ○ none none Example 6 ◎ none none Example 7 ◎ none none Example 8 ◎ none none Comparative Example 1 × has exist none Comparative Example 2 × none has exist Comparative Example 3 × none has exist Comparative Example 4 × none has exist

Referring to Table 2, it can be seen that the characteristics having excellent performance when etching in Examples 1 to 8. On the other hand, in the case of etching in Comparative Examples 1 to 4 showed that the lower film damage and residues occur. Specifically, when the amount of the fluorine-containing compound is exceeded as in the case of Comparative Example 1, a lower film attack occurs. As in the case of Comparative Example 2, when the amount of the compound containing the NH ₄ ⁺ salt is exceeded, residues are generated due to the decrease in the etching rate. As in the case of Comparative Example 3, when the amount of H ₂ O ₂ is contained in a small amount, poor etching and residues are left due to uneven etching. And in the case of Comparative Example 4 does not contain H ₂ O ₂ , the etching rate is very low, the etching profile is very non-uniform and the residue was severely appeared.

1 is a SEM photograph after etching Ti / Al / Ti using Example 6. FIG.

FIG. 2 is a SEM photograph after etching Ti / Al / Ti and stripping a photoresist using Example 6. FIG.

Claims (6)

Regarding the total weight of the composition, H ₂ O ₂ 5-30 weight percent; 0.1 to 2 wt% of a fluorine-containing compound; 0.5 to 5 weight percent of a compound comprising an NH ₄ ⁺ salt; And An etchant composition comprising a residual amount of water. The method according to claim 1, The fluorine-containing compound is an etchant composition, characterized in that the compound can be dissociated into fluorine ions or polyatomic fluorine ions. The method according to claim 2, The fluorine-containing compound is an etching solution composition, characterized in that one or two or more selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium bifluoride, and potassium bifluoride. The method according to claim 1, The compound containing the NH ₄ ⁺ salt is CH ₃ COONH ₄ , NH ₄ NO ₃ , (NH ₄ ) ₂ SO ₄ NH ₄ C ₆ H ₅ O ₂ , (NH ₄ ) ₂ S ₂ O ₈ NH ₄ Cl, NH ₄ H ₂ PO ₄ , NH ₄ OOCH, NH ₄ HCO ₃ , H ₄ NO ₂ CCH ₂ C (OH) (CO ₂ NH ₄ ) CH ₂ CO ₂ NH ₄ , NH ₄ PF ₆ , HOC (CO ₂ H) ( CH ₂ CO ₂ NH ₄ ) ₂ and H ₂ NSO ₃ NH _{4 The} etchant composition characterized in that one or two or more selected from the group consisting of. The method according to claim 1, The etchant composition is an etchant composition, characterized in that the wet wet etching a single layer consisting of titanium or titanium alloys, aluminum or aluminum alloy and multiple layers or more of the double layer comprising the metal. The method according to claim 1, The etchant composition is an etchant composition, characterized in that it contains one or two or more selected from the group consisting of etch regulators, surfactants, metal ion blocking agents, corrosion inhibitors and pH regulators.

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