KR102456623B1 - Additive for etchant composition and etchant composition comprising the same - Google Patents

Abstract

The present invention relates to an etchant additive and an etchant composition comprising the same. An objective of the present invention is to provide an etchant additive capable of preventing phenomena such as undercut and circuit lifting while increasing the squareness of a formed circuit pattern during the etching process of the remaining metal seed layer. The etchant additive includes a metal compound containing at least one selected from a group consisting of Au, Ag, Al, Cu, Fe, Mo, Zn, Mg, Ni, Co K, Na, Ca and Bi.

Description

An etchant additive and an etchant composition comprising the same

The present invention relates to an etchant composition for etching a residual metal seed layer in a circuit pattern process of a circuit board and an etchant additive included in the etchant composition.

A circuit board used in the manufacture of electric/electronic devices is generally manufactured through a process of patterning a metal film on a substrate into a microstructure. A technique for patterning the microstructure may include a lithography process using a photocurable resin. However, the lithography process has a minimum achievable pitch of 35 μm, and there is a limit to forming a circuit pattern having a finer structure in response to an increase in demand for high-functionality and high-integration circuits.

Accordingly, the SAP (Semi Additive Process) process and the mSAP (Modified Semi-Additive Process) process have been introduced to form a microstructured circuit pattern by improving the lithography process. In these processes, a pattern is formed using a photocurable resin on a substrate on which a metal seed layer is thinly formed, a metal component is plated on the formed pattern, and then the photocurable resin is removed and the metal seed layer is etched through processes such as etching. to form a structural circuit pattern.

Although the implementation of microstructured circuit patterns has been realized to some extent through the SAP process and the mSAP process, undercuts occur due to non-uniform etching of the metal seed layer or circuit floatation occurs due to the metal seed layer falling off. A problem is emerging. In addition, an etchant containing phosphoric acid, nitric acid, acetic acid, hydrochloric acid, sulfuric acid, or hydrogen peroxide is used as an etchant for etching the metal seed layer. This etchant over-etches the circuit pattern during the process of etching the metal seed layer. There is also the problem of reducing the uniformity (perpendicularity).

Japanese Laid-Open Patent Publication No. 2006-009122

An object of the present invention is to provide an etchant additive capable of preventing phenomena such as undercut and circuit floatation from occurring while increasing the perpendicularity of a formed circuit pattern during an etching process of a residual metal seed layer.

In addition, the present invention is to provide an etchant composition comprising the etchant additive.

In order to solve the above problems, the present invention provides a metal containing at least one metal selected from the group consisting of Au, Ag, Al, Cu, Fe, Mo, Zn, Mg, Ni, Co, K, Na, Ca and Bi. An etchant additive comprising a compound is provided.

The metal compound is copper sulfate, copper oxide, zinc chloride, zinc sulfide, zinc nitrate, zinc acetate, zinc acetate, ammonium molybdate (Ammonium) molybdate), molybdenum disulfide, molybdenum nitride, molybdenum oxide, magnesium carbonate, magnesium sulfide, magnesium chloride, potassium oxalate ), potassium chloride, potassium citrate, sodium citrate, sodium chloride, sodium phosphate, sodium dodecyl sulfate, sodium carbonate, It may be at least one selected from the group consisting of sodium bicarbonate and sodium acetate.

The etchant additive of the present invention may further include at least one selected from the group consisting of an organic acid, an alcohol-based compound, and a nitrogen-containing compound.

The organic acid may be at least one selected from the group consisting of oxalic acid, citric acid, malonic acid, succinic acid, acetic acid, maleic acid, propionic acid, glycolic acid, and glycolic acid.

The alcohol-based compound is methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol (Polyethylene glycol) , may be at least one selected from the group consisting of polypropylene glycol and EO-PO copolymer.

The nitrogen-containing compound is 5-amino-1H-tetrazole, 1H-tetrazole, 1-methyltetrazole, 1,5-diethyltetrazole, 5-phenyl-1H-tetrazole, benzothiazole, sodium tolyltria It may be at least one selected from the group consisting of sol, benzotriazole, imidazole, 3-amino-1,2,4-triazolesulfathiazole and carboxytriazole.

The mixing ratio (a:b:c:d) of the metal compound (a), the organic acid (b), the alcohol-based compound (c), and the nitrogen-containing compound (d) is 1:10 to 20:10 to 20 : It may be a weight ratio of 0.5 to 1.

Meanwhile, the present invention provides an etchant composition comprising the etchant additive.

The present invention relates to an etchant additive capable of preventing phenomena such as undercut and circuit floatation from occurring while increasing the perpendicularity of a formed circuit pattern in the process of etching a residual metal seed layer, and an etchant composition comprising the same can provide

1 is a schematic diagram for explaining the mechanism of action of the etchant additive according to the present invention.
2 is an image for explaining Experimental Example 1 according to the present invention.
3 is an image for explaining Experimental Example 2 according to the present invention.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

The present invention relates to an etchant additive capable of selectively etching a metal seed layer while preventing over-etching of a circuit pattern in the process of etching a residual metal seed layer, and an etchant composition comprising the same, see FIG. 1 Thus, it is described in detail as follows.

The etchant additive according to the present invention includes a metal compound. The etchant additive according to the present invention may further include at least one selected from the group consisting of an organic acid, an alcohol-based compound, and a nitrogen-containing compound.

The metal compound included in the etchant additive according to the present invention provides metal ions to the etchant composition, and the provided metal ions protect the surface of the circuit pattern, thereby preventing over-etching of the circuit pattern. It can function as an etch inhibitor. have.

The metal compound may contain at least one metal selected from the group consisting of Au, Ag, Al, Cu, Fe, Mo, Zn, Mg, Ni, Co, K, Na, Ca and Bi. Specifically, the metal compound may contain a metal ion in which at least one metal selected from the group consisting of Cu, Mo, Zn, Mg, K and Na is ionized. Here, the content of the metal (metal ion) contained in the metal compound may be 0.1 to 3.0 g/L, specifically 0.1 to 1.0 g/L, based on the total concentration of the metal compound, in consideration of the above-described etch inhibitor function. .

More specifically, the metal compound is copper sulfate, copper oxide, zinc chloride, zinc sulfide, zinc nitrate, zinc nitrate, zinc acetate, molybdic acid. Ammonium molybdate, Molybdenum disulfide, Molybdenum nitride, Molybdenum oxide, Magnesium carbonate, Magnesium sulfide, Magnesium chloride, Potassium oxalate (Potassium oxalate), potassium chloride, potassium citrate, sodium citrate, sodium chloride, sodium phosphate, sodium dodecyl sulfate, sodium carbonate carbonate), sodium bicarbonate (Sodium bicarbonate), and sodium acetate (Sodium acetate) may be at least one selected from the group consisting of. As the metal compound is the compound, the surface protection of the circuit pattern made of the metal component can be efficiently made to increase the squareness of the circuit pattern, and thus the pitch interval is 30 μm or less (specifically, 20 μm or less) of the microstructure. A circuit pattern can be implemented.

The organic acid further included in the etchant additive according to the present invention may function as an etch rate regulator to control the etch rate of the remaining metal seed layer. Specifically, the organic acid may serve to increase the etching rate of the metal seed layer so that the remaining metal seed layer can be etched faster than the circuit pattern.

In consideration of etching efficiency, the organic acid may be at least one selected from the group consisting of oxalic acid, citric acid, malonic acid, succinic acid, acetic acid, maleic acid, propionic acid, glycolic acid, and glycolic acid.

The alcohol-based compound further included in the etchant additive according to the present invention may function as an etchant by increasing the penetration of the etchant composition into the metal seed layer to prevent the metal seed layer residue from remaining on the substrate. Specifically, the alcohol-based compound activates the interface between the substrate and the metal seed layer (a surfactant function), thereby increasing the etching rate of the metal seed layer, thereby minimizing the remaining metal seed layer components on the surface of the substrate.

When considering the penetration of these alcohol-based compounds into the metal seed layer, methanol, ethanol, propyl alcohol (Propyl alcohol), isopropyl alcohol (Isopropyl alcohol), butyl alcohol (Butyl alcohol), ethylene glycol ( Ethylene glycol), polyethylene glycol (Polyethylene glycol), polypropylene glycol (Polypropylene glycol), and may be at least one selected from the group consisting of EO-PO copolymer.

The nitrogen-containing compound further included in the etchant additive according to the present invention may serve as an auxiliary function of protecting the circuit pattern while increasing the etching rate of the metal seed layer. Specifically, the nitrogen-containing compound increases the etching rate of the metal seed layer and decreases the surface etching rate of the circuit pattern formed through electroplating, thereby minimizing the residual metal seed layer component on the surface of the substrate. .

Such nitrogen-containing compounds include 5-amino-1H-tetrazole, 1H-tetrazole, 1-methyltetrazole, 1,5-diethyltetrazole, 5-phenyl-1H-tetrazole, benzothiazole, sodium tolyltria It may be at least one selected from the group consisting of sol, benzotriazole, imidazole, 3-amino-1,2,4-triazolesulfathiazole and carboxytriazole.

The mixing ratio of the metal compound, the organic acid, the alcohol-based compound and the nitrogen-containing compound included in the etchant additive according to the present invention is 1:10 to 20:10 to 20:0.5 to 1 by weight in consideration of the etching efficiency of the metal seed layer. (specifically, 1:10:10:1, 1:10:20:0.5, 1:15:20:0.5, or 1:20:20:0.5).

The present invention is an etchant composition capable of forming a circuit pattern having a microstructure having a pitch interval of 30 µm or less (specifically, 20 µm or less) by including the etchant additive and forming a circuit pattern having a perpendicularity of 90% or more provides Since the etchant composition includes the etchant additive, it is possible to minimize the occurrence of undercutting of the circuit pattern and the circuit lifting phenomenon, which will be described in detail as follows.

The etchant composition according to the present invention includes an etchant additive further comprising at least one selected from the group consisting of a metal compound and, optionally, an organic acid, an alcohol-based compound, and a nitrogen-containing compound. Here, a detailed description of the metal compound, the organic acid, the alcohol-based compound, and the nitrogen-containing compound is the same as described above, and thus will be omitted.

The concentration of the metal compound included in the etchant composition according to the present invention may be 0.1 to 2 g/L (specifically, 0.1 to 1.0 g/L). When the concentration of the metal compound is less than 0.1 g/L, the surface protection of the circuit pattern by metal ions is not smooth, and over-etching of the circuit pattern and lowering of squareness may occur. The etch rate of the seed layer may be reduced so that the metal seed layer may remain.

The concentration of the organic acid included in the etchant composition according to the present invention may be 5 to 15 g/L (specifically, 7 to 12 g/L). If the concentration of the organic acid is less than 5 g/L, the ability to increase the etching rate of the metal seed layer may be deteriorated. can be

The concentration of the alcohol-based compound included in the etchant composition according to the present invention may be 10 to 20 g/L (specifically, 12 to 18 g/L). When the concentration of the alcohol-based compound is less than 10 g/L, the penetration ability of the etchant composition into the metal seed layer may be reduced. can be

The concentration of the nitrogen-containing compound included in the etchant composition according to the present invention may be 0.05 to 0.5 g/L (specifically, 0.05 to 0.2 g/L). When the concentration of the nitrogen-containing compound is less than 0.05 g/L, the metal seed layer remains and the uniformity of the circuit pattern (reduction in flatness of the top portion of the circuit pattern) may decrease. The etch amount of the seed layer may become excessively high, and undercut may occur.

The etchant composition according to the present invention may further include a conventionally known etchant. Specifically, the etchant composition according to the present invention may further include at least one selected from the group consisting of phosphoric acid, nitric acid, acetic acid, hydrochloric acid, sulfuric acid, and hydrogen peroxide.

In addition, the etchant composition according to the present invention may further include a commonly known additive (eg, an etchant stabilizer).

The etchant composition according to the present invention may be mainly used in the process of etching the metal seed layer in the SAP process or mSAP process for forming a circuit pattern on a substrate, but is not limited thereto, and can be used in various ways if the etching of the metal component is required. can In addition, the metal seed layer or metal component to be etched may include at least one selected from the group consisting of copper, gold, silver, and nickel.

On the other hand, the etching conditions for etching the metal seed layer with the etchant composition according to the present invention are not particularly limited, but in the case of the SAP process, an etching amount of 0.5 to 0.8 μm/min can be applied at 30 ° C., and in the case of the mSAP process, etching at 35 ° C. An amount of 3.0 to 4.0 μm/min may be applied.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

[Example 1]

Mo-containing metal compound 0.1 to 2.0 g/L, citric acid 5 to 15 g/L, polyethylene glycol 10 to 20 g/L, and 5-amino-1H-tetrazole 0.05 to 0.5 g/L mixed etchant additive , 95% sulfuric acid 30 to 60 g / L and 35% hydrogen peroxide 20 to 40 g / L of an etchant composition having a composition was prepared.

[Comparative Example 1]

An etchant composition having a composition of 40 g/L of 95% sulfuric acid and 30 g/L of 35% hydrogen peroxide was prepared.

[Experimental Example 1]

A copper seed layer was formed by plating chemical copper with a thickness of 0.3 to 0.6 μm on the lower insulating layer by applying a conventionally known SAP process, followed by pattern electroplating to form a circuit pattern (Bare).

Next, the circuit pattern was confirmed by FE-SEM after etching the substrate on which the circuit pattern was formed with the etchant composition of Example 1 and Comparative Example 1 by 1.4 μm (etching temperature 30° C.), and the results are shown in Table 1 and FIG. 2 below. It was.

division Top length (㎛) Bottom length (㎛) circuit layer thickness Squareness (%) Before etching (Bare) 14.9 17.9 17.2 83.2 Comparative Example 1 12.3 15.3 15.5 80.4 Example 1 11.5 12.6 15.3 91.3

Referring to Table 1 and FIG. 2, it was confirmed that as the copper seed layer was etched with Example 1, which is the etchant composition according to the present invention, a circuit pattern having a high degree of perpendicularity and uniformity and fine spacing between the patterns was formed.

[Experimental Example 2]

The circuit pattern was etched in the same manner as in Experimental Example 1, except that the etching amount (etched thickness) was etched to 0.5 μm, 1.0 μm, and 2.0 μm, respectively, and the results for the under cut after etching are shown in Table 2 and FIG. 3 is shown.

etch amount 0.5 μm 1.0 μm 2.0 μm Before etching (Bare)
Under cut length 0.9 μm 0.9 μm 0.9 μm Comparative Example 1
Under cut length 0.9 μm 1.4 μm 2.1 μm Example 1
Under cut length 0.7 μm 0.3 μm 0.1 μm

Referring to Tables 2 and 3, when Example 1, which is the etchant composition according to the present invention, was applied, it was confirmed that the under cut was controlled even if the etching amount was increased.

[Experimental Example 3]

The circuit pattern was etched in the same manner as in Experimental Example 1, except that the etching amount (etch thickness) was 0.6 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.4 μm, and 1.6 μm, respectively. Table 3 shows.

etch amount 0.6 μm 0.8 μm 1.0 μm 1.2 μm 1.4 μm 1.6 μm Copper
Remove the seed layer Comparative Example 1 leftover leftover no residue no residue no residue no residue Example 1 leftover leftover leftover no residue no residue no residue circuit excitation
Occur Comparative Example 1 no lift no lift exhilaration exhilaration exhilaration exhilaration Example 1 no lift no lift no lift no lift no lift no lift

Referring to Table 3, it was confirmed that when Example 1, which is the etchant composition according to the present invention, was applied, the copper seed layer did not remain and the circuit lifting phenomenon did not occur even if the etching amount was increased.

Claims (11)

A metal compound containing Mo as an etch inhibitor, an organic acid as an etch rate regulator, an alcohol compound as an etch penetrant, and a nitrogen-containing compound in a weight ratio of 1:10 to 20:10 to 20:0.5 to 1 by weight In the copper etchant composition comprising a phosphorus etchant additive,
The metal compound containing Mo is at least one selected from the group consisting of ammonium molybdate, molybdenum disulfide, molybdenum nitride and molybdenum oxide,
The organic acid is at least one selected from the group consisting of oxalic acid, citric acid, malonic acid, succinic acid, acetic acid, maleic acid, propionic acid, glycolic acid and glycolic acid,
The alcohol-based compound is methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol (Polyethylene glycol) , at least one selected from the group consisting of polypropylene glycol and EO-PO copolymer,
The nitrogen-containing compound is 5-amino-1H-tetrazole, 1H-tetrazole, 1-methyltetrazole, 1,5-diethyltetrazole, 5-phenyl-1H-tetrazole, benzothiazole, sodium tolyltria It is at least one selected from the group consisting of sol, benzotriazole, imidazole, 3-amino-1,2,4-triazolesulfathiazole and carboxytriazole,
The etching solution composition has a rate of etching the copper seed layer during the process to which the semi-additive method is applied is 0.5 to 0.8 μm/min at 30° C.,
The copper seed layer etchant composition of the semi-additive method, characterized in that the undercut length of the circuit pattern is reduced in the process that the copper etch thickness at 30°C to which the semi-additive method is applied is changed from 0.5 to 2.0 µm. delete delete delete delete delete delete According to claim 1,
The metal compound is a copper seed layer etchant composition of a semi-additive method to prevent over-etching of the metal layer by protecting the surface of the metal layer. delete According to claim 1,
The copper seed layer etchant composition of the semi-additive method in which the concentration of the metal compound is 0.1 to 2 g/L. delete

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