KR102584044B1 - 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 containing the same, wherein the etchant additive is selected from the group consisting of Au, Ag, Al, Cu, Fe, Mo, Zn, Mg, Ni, Co K, Na, Ca and Bi. It includes a metal compound containing one or more of the following.

Description

Etch additive and etchant composition containing the same {ADDITIVE FOR ETCHANT COMPOSITION AND ETCHANT COMPOSITION COMPRISING THE SAME}

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

Circuit boards used in the manufacture of electrical/electronic devices are generally manufactured through a process of patterning the metal film on the board into a microstructure. A technique for patterning the microstructure includes a lithography process using photocurable resin. However, the lithography process has a minimum pitch of 35 ㎛, which limits the ability to form circuit patterns with finer structures to meet the increasing demand for high-performance and highly integrated circuits.

Accordingly, the SAP (Semi Additive Process) process and the mSAP (Modified Semi-Additive Process) process, which enable the formation of fine-structured circuit patterns by improving the lithography process, have been introduced. These processes involve forming a pattern using a photocurable resin on a substrate with a thin metal seed layer, plating a metal component on the formed pattern, and then going through processes such as removing the photocurable resin and etching the metal seed layer to form a fine layer. Forming a structural circuit pattern.

Although the implementation of microstructured circuit patterns has been realized to some extent through SAP processes, mSAP processes, etc., undercuts occur due to uneven etching of the metal seed layer or circuit lifting occurs due to the removal of the metal seed layer. A problem is emerging. In addition, etchants containing phosphoric acid, nitric acid, acetic acid, hydrochloric acid, sulfuric acid, or hydrogen peroxide are used as etchants to etch the metal seed layer. These etchants cause overetching of the circuit pattern during the process of etching the metal seed layer. There is also a problem of lowering uniformity (squareness).

Japanese Patent Publication No. 2006-009122

The present invention seeks to provide an etchant additive that can prevent phenomena such as undercut and circuit lifting while increasing the perpendicularity of the formed circuit pattern during the etching process of the remaining metal seed layer.

Additionally, the present invention seeks to provide an etchant composition containing the above 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. Provided is an etchant additive containing a compound.

The metal compounds include copper sulfate, copper oxide, zinc chloride, zinc sulfide, zinc nitrate, zinc acetate, and ammonium molybdate. 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 one or more selected from the group consisting of sodium bicarbonate and sodium acetate.

The etchant additive of the present invention may further include one or more selected from the group consisting of organic acids, alcohol-based compounds, and nitrogen-containing compounds.

The organic acid may be one or more 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 compounds include Methanol, Ethanol, Propyl alcohol, Isopropyl alcohol, Butyl alcohol, Ethylene glycol, and Polyethylene glycol. , polypropylene glycol, and EO-PO copolymer.

The nitrogen-containing compounds include 5-amino-1H-tetrazole, 1H-tetrazole, 1-methyltetrazole, 1,5-diethyltetrazole, 5-phenyl-1H-tetrazole, benzothiazole, sodium tolyltriazole It may be one or more 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 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 containing the above etchant additive.

The present invention provides an etchant additive that can prevent phenomena such as undercut and circuit lifting while increasing the perpendicularity of the formed circuit pattern during the etching process of the remaining metal seed layer, and an etchant composition containing the same. can be provided.

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

Terms or words used in the description and claims of the present invention should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately use the concepts of terms to explain his invention in the best way. Based on the principle of definability, it must be interpreted with meaning and concept consistent with the technical idea of the present invention.

The present invention relates to an etchant additive that allows selective etching of a metal seed layer while preventing overetching of the circuit pattern during the process of etching the remaining metal seed layer, and to an etchant composition containing the same, see FIG. 1. To explain in detail, it is 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 one or more selected from the group consisting of organic acids, alcohol-based compounds, and nitrogen-containing compounds.

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 can function as an etch inhibitor to prevent overetching of the circuit pattern by protecting the surface of the circuit pattern. there is.

These metal compounds may contain one or more metals 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 one or more metals selected from the group consisting of Cu, Mo, Zn, Mg, K, and Na are ionized. Here, considering the above-described etching inhibitor function, 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. .

More specifically, the metal compounds include copper sulfate, copper oxide, zinc chloride, zinc sulfide, zinc nitrate, zinc acetate, and 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, and sodium acetate. As the metal compound is the above-described compound, the surface protection of the circuit pattern made of the metal component can be efficiently protected, thereby increasing the perpendicularity of the circuit pattern, resulting in a fine structure with a pitch interval of 30 ㎛ or less (specifically, 20 ㎛ or less). Circuit patterns can be implemented.

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

Considering etching efficiency, such organic acid may be one or more 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 can function as an etch penetrant to increase the penetration of the etchant composition into the metal seed layer and prevent 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 (surfactant function) and increases the etching rate of the metal seed layer, thereby minimizing the remaining metal seed layer components on the substrate surface.

Considering the ability to penetrate the metal seed layer, these alcohol-based compounds include Methanol, Ethanol, Propyl alcohol, Isopropyl alcohol, Butyl alcohol, and ethylene glycol ( It may be one or more selected from the group consisting of ethylene glycol, polyethylene glycol, polypropylene glycol, and EO-PO copolymer.

The nitrogen-containing compound further included in the etchant additive according to the present invention can serve an auxiliary function of protecting the circuit pattern while increasing the etching rate of the metal seed layer. Specifically, nitrogen-containing compounds increase the etching rate of the metal seed layer and reduce the surface etching rate of the circuit pattern formed through electroplating, thereby minimizing the remaining metal seed layer components on the substrate surface. .

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

Considering the etching efficiency of the metal seed layer, the mixing ratio of the metal compound, organic acid, alcohol compound, and nitrogen-containing compound included in the etchant additive according to the present invention is a weight ratio of 1:10 to 20:10 to 20:0.5 to 1. (Specifically, it may be 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 that, by containing the etchant additive, allows the formation of a circuit pattern with a fine structure having a pitch interval of 30 ㎛ or less (specifically, 20 ㎛ or less) and allows the formation of a circuit pattern with a perpendicularity of 90% or more. provides. As this etchant composition contains the etchant additive, it is possible to minimize the occurrence of undercut in the circuit pattern and the phenomenon of circuit lifting, which will be described in detail as follows.

The etchant composition according to the present invention includes a metal compound and, optionally, an etchant additive further comprising at least one selected from the group consisting of an organic acid, an alcohol-based compound, and a nitrogen-containing compound. Here, detailed descriptions of metal compounds, organic acids, alcohol-based compounds, and nitrogen-containing compounds are the same as described above and will therefore 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). If 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, which may cause overetching of the circuit pattern and a decrease in perpendicularity, and if it exceeds 2 g/L, the metal ion may not protect the surface of the circuit pattern smoothly. The etch rate of the seed layer may be reduced and the metal seed layer may remain.

The concentration of the organic acid contained 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 organic acid is less than 5 g/L, the ability to increase the etching rate of the metal seed layer may be reduced, and if it exceeds 15 g/L, the etching rate of the metal seed layer becomes excessively high, causing circuit excitation. It 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). If 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 decrease, and if it exceeds 20 g/L, the etching amount of the metal seed layer becomes excessively high, resulting in undercut. It 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). If the concentration of nitrogen-containing compounds is less than 0.05 g/L, the metal seed layer may remain and the uniformity of the circuit pattern (reduction in flatness of the top part of the circuit pattern) may deteriorate, and if it exceeds 0.5 g/L, the metal seed layer may remain. If the etching amount of the seed layer becomes excessively high, undercut may occur.

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

Additionally, the etchant composition according to the present invention may further include commonly known additives (eg, etch stabilizers).

The etchant composition according to the present invention can be mainly used in the process of etching a metal seed layer in a SAP process or mSAP process for forming a circuit pattern on a substrate, but is not limited to this and can be used in a variety of ways as long as it is a process that requires etching of metal components. You can. Additionally, the metal seed layer or metal component to be etched may include one or more selected from the group consisting of copper, gold, silver, and nickel.

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

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to illustrate the present invention, and it is obvious 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 to these alone.

[Example 1]

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

[Comparative Example 1]

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

[Experimental Example 1]

A commonly known SAP process was applied to form a copper seed layer by plating chemical copper with a thickness of 0.3 to 0.6 ㎛ on the lower insulating layer, and then pattern electroplating was performed to form a circuit pattern (Bare).

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

division Top length (㎛) Bottom length (㎛) circuit layer thickness Perpendicularity (%) Before etching 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 Figure 2, it was confirmed that by etching the copper seed layer with Example 1, which is the etchant composition according to the present invention, a circuit pattern was formed with high perpendicularity, uniformity, and fine spacing between patterns.

[Experimental Example 2]

The circuit pattern was etched in the same process as Experimental Example 1, except that the etching amount (etch thickness) was 0.5 ㎛, 1.0 ㎛, and 2.0 ㎛, respectively. The results of undercut after etching are shown in Table 2 and Figure 2 below. It is shown in 3.

Etch amount 0.5 ㎛ 1.0 ㎛ 2.0 ㎛ Before etching
Under cut length 0.9㎛ 0.9㎛ 0.9㎛ Comparative Example 1
Under cut length 0.9㎛ 1.4 ㎛ 2.1 ㎛ Example 1
Under cut length 0.7 ㎛ 0.3㎛ 0.1 ㎛

Referring to Table 2 and Figure 3, when applying Example 1, which is the etchant composition according to the present invention, it was confirmed that undercut was controlled even when the etching amount increased.

[Experimental Example 3]

The circuit pattern was etched in the same process as Experiment 1 above, except that the etching amount (etch thickness) was 0.6 ㎛, 0.8 ㎛, 1.0 ㎛, 1.2 ㎛, 1.4 ㎛, and 1.6 ㎛, respectively. The results are as follows. It is shown in Table 3.

Etch amount 0.6 ㎛ 0.8 ㎛ 1.0 ㎛ 1.2 ㎛ 1.4 ㎛ 1.6 ㎛ copper
Seed layer removal Comparative Example 1 Jandong has Jandong has No jangdong No jangdong No jangdong No jangdong Example 1 Jandong has Jandong has Jandong has No jangdong No jangdong No jangdong circuit excitation
generation Comparative Example 1 No restlessness No restlessness Excited and excited Excited and excited Excited and excited Excited and excited Example 1 No restlessness No restlessness No restlessness No restlessness No restlessness No restlessness

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

Claims (11)

Included in an etchant composition for removing the remaining metal seed layer for etching the remaining metal seed layer on a substrate with a circuit pattern formed by a semi-additive process or a modified semi-additive process. As an etchant additive,
The metal seed layer of the substrate is chemically plated with copper, and the circuit pattern is electroplated,
The etchant composition includes at least one etchant selected from the group consisting of phosphoric acid, nitric acid, acetic acid, hydrochloric acid, sulfuric acid, and hydrogen peroxide, and the etchant additive,
The etchant additive includes metal ions as an etch inhibitor to prevent overetching of the metal seed layer; And one or more additives selected from the group consisting of organic acids, alcohol-based compounds, and nitrogen-containing compounds to assist in etching the remaining metal,
The content of the metal ion is 0.1 to 3.0 g/L,
The etchant additive wherein the metal of the metal ion is Mo. delete In claim 1,
The organic acid functions as an etch rate controller to increase the etch rate of the remaining metal seed layer,
The alcohol-based compound functions as an etching penetrant to increase the penetration power of the etchant composition into the metal seed layer,
The nitrogen-containing compound is an etchant additive that serves an auxiliary function to protect the circuit pattern while increasing the etching rate of the metal seed layer. delete In claim 1,
The etchant additive wherein the nitrogen-containing compound is an azole-based compound. delete An etchant composition for removing a residual metal seed layer comprising the etchant additive according to any one of claims 1, 3, and 5. In claim 7,
An etchant composition for removing a residual metal seed layer, wherein when the etchant composition is applied to the substrate, the perpendicularity of the circuit pattern is increased compared to before etching. In claim 8,
An etchant composition for removing a residual metal seed layer, wherein the perpendicularity is 85% or more. delete delete