KR20100038748A - Etchant, method of fabricating a metal interconnetion using the same and circuit board fabricated by using the same - Google Patents

Abstract

PURPOSE: An etchant is provided to implement a metal interconnection with a uniform and fine line width while not generating an undercut using existing wet etching equipment by forming an etching inhibition layer of a triazole-based compound on sidewalls of metal patterns. CONSTITUTION: An etchant(140) comprises ferric chloride(FeCl3) and a triazole-based compound. The triazole-based compound is included in the amount of 0.3-1.0% and the ferric chloride has the content of 5-25%. The triazole-based compound comprises at least one selected from the group consisting of benzotriazole, benzotriazole carboxylic acid, sodium benzotriazole, and potassium tolytriazole.

Description

Etch, method of fabricating a metal wiring using the same and a circuit board fabricated using the same {Etchant, method of fabricating a metal interconnetion using the same and circuit board fabricated by using the same}

The present invention relates to an etching solution, a wiring forming method and a circuit board, and more particularly, to an etching solution, a metal wiring forming method using the same, and a circuit board manufactured using the same.

Due to the trend toward high integration, miniaturization, and weight reduction of electronic devices and electronic components equipped with semiconductor chips, technologies that can realize high integration in the manufacturing process as well as the design of electronic circuits constituting them are being introduced. Such an electronic device may be implemented in the form of being electrically connected to a semiconductor chip and a printed circuit board (PCB) having multilayer wirings formed thereon. As the degree of integration of semiconductor chips increases, the spacing between external terminals of the semiconductor chips decreases. As a result, the spacings of the wirings that electrically connect these conductive pads formed on the printed circuit board to be reduced correspondingly to the external terminals of the chip.

On the other hand, the process of forming the wiring on the printed circuit board may be manufactured through a technique similar to the technique used in the wiring forming process in the semiconductor chip. For example, the wiring mounted on the printed circuit board may be formed to have a predetermined shape on the bulk substrate constituting the printed circuit board through a patterning process with respect to the metal film. The patterning process may be configured in the order of a deposition process, a photolithography process, an etching process, and a cleaning process, similarly to a manufacturing process applied to a semiconductor chip. In this case, the technique used in the etching process may be roughly classified into wet etching and dry etching, depending on the material used for etching.

1A to 1C are cross-sectional views illustrating a method of forming a metal wire according to a conventional wet etching method.

Referring to FIG. 1A, a conductive film such as a metal film 20 is deposited on the substrate 10. A photoresist film may be formed on the metal film 20. A photoresist pattern 30 having a predetermined pattern is formed through the photolithography process on the photoresist film.

Referring to FIG. 1B, a wet etching process is performed on the metal film 20 using the photoresist pattern 30 as an etching mask. The sidewall profile of the metal film pattern 22 formed during the progress of the wet etching does not match the sidewall profile of the photoresist pattern 30. This is a common phenomenon in wet etching due to the radial progression of the etching process. That is, the wet etching is performed by isotropic etching, so that etching is performed up to the metal layer 20 under the photoresist pattern 30 to generate an undercut (U).

Referring to FIG. 1C, after the photoresist pattern 30 is removed by a method such as an ashing process, the metal film pattern 22 remains. Due to the isotropic etching described above, the metal film pattern 22 is formed to be much smaller than 1 without having a top / bottom T / B ratio of 1 to the bottom width. As the degree of integration of wirings disposed on a printed circuit board increases, there is a limit to forming a fine pattern in a situation in which the width of the metal wiring is required to be reduced. In addition, since the pitch size set at the time of fabrication of the metal wire is reduced, the bottoms of the metal film patterns 22 may not be etched and may be shorted without being separated.

In order to overcome the above-described phenomenon, dry etching using plasma may be used, but this involves expensive equipment compared to wet etching. Therefore, various techniques for preventing the occurrence of undercuts in wet etching have been studied.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an etching solution that contributes to suppressing lateral etching by using an etching solution containing a triazole compound.

Another object of the present invention is to provide a metal wiring formation method that contributes to suppressing lateral etching by using an etchant containing a triazole-based compound.

Another object of the present invention is to provide a circuit board having a metal wiring having an etch inhibiting film by using an etchant containing a triazole-based compound.

According to an aspect of the present invention for achieving the above technical problem, an etchant is provided. The etchant contains ferric chloride (FeCl ₃ ) and triazole type compounds.

In some embodiments of the present invention, the triazole-based compound It may be contained at a concentration of 0.3 to 1.0%.

In other embodiments, the ferric chloride may have a content of 5 to 25%.

In another embodiment, the triazole-based compound is composed of benzotriazole (BTA), benzotriazole carboxylic acid, sodium benzotriazole, and potasium tolytriazole. It may contain at least one crowd.

In still other embodiments, the etchant may further contain a surfactant. The surfactant may be contained at a concentration of 1.0 to 3.0%. In this case, the surfactant may contain at least one moiety consisting of an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant. The amphoteric surfactant may include at least one of a group consisting of a carboxybetaine type alkyl betaine, a fatty acid amidopropyl betaine, and an alkyl ester. The nonionic surfactant may contain at least one selected from the group consisting of rioxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene alkyl ether, polyoxypropylene and amine oxide. The cationic surfactant may contain at least one of the group consisting of dimethylalkylamine, cetyltrimethylammonium chloride and distearyldimethylammonium chloride.

In still other embodiments, the etchant may further contain an antioxidant stabilizer. In this case, the antioxidant stabilizer may be contained at a concentration of 5 to 20 ppm. The antioxidant stabilizer may contain at least one of a group consisting of phenolic, amine-based compounds, phosphorus-containing compounds, sulfur-containing compounds and butyl hydrooxyanisole (BHA) .

According to another aspect of the present invention for achieving the above technical problem, a metal wiring forming method is provided. The metal wiring forming method includes forming a metal film having a mask pattern on a substrate. A metal layer is etched using the mask pattern as an etch mask to form metal lines, and an etching solution containing ferric chloride (FeCl 3) and a triazole type compound is used during the etching.

In some embodiments of the present invention, the metal wire is formed to include an etch inhibiting film on the metal pattern and sidewalls of the metal pattern, wherein the etch inhibiting film is exposed below the mask pattern while etching the metal film. It can be formed on the sidewalls of the pattern.

In other embodiments, the metal film may be formed of a film including copper.

In still other embodiments, the etching may be performed at a temperature of 20 to 50 ℃.

In another embodiment, the etching may be performed by spraying the etchant toward the substrate, and the spraying pressure may be set to 1 to 5 kg / cm ² .

According to another aspect of the present invention for achieving the above technical problem, a circuit board is provided. The circuit board includes a first metal wire having a first metal pattern on at least one side of the first insulating substrate and a first etch inhibiting film on sidewalls of the first metal pattern. In this case, the first etch inhibiting film is formed of a metal complex containing a triazole compound.

In some embodiments of the present disclosure, a second insulating substrate positioned on at least one side of the first insulating substrate having the first metal wiring and a second metal wiring positioned on the second insulating substrate may be included. have. In this case, the second metal interconnection may include a second etching inhibiting film on the second metal pattern and sidewalls of the second metal pattern, and the second etching inhibiting film may be formed of a metal complex containing a triazole-based compound. Can be.

In other embodiments, the metal wires are formed using an etchant containing the ferric chloride (FeCl ₃ ) and a triazole type compound, and the etch inhibiting layer is exposed to the metal during etching of the metal film. It may be formed by reacting with the sidewalls of the pattern and the triazole-based compound.

According to the present invention, a metal wiring is formed on a substrate using an etchant containing ferric chloride and a triazole-based compound. As a result, an etch inhibiting film is formed in the form of a complex formed by reacting a triazole-based compound and a metal on sidewalls of the metal pattern forming the metal wiring during the etching process. Accordingly, the shape of the undercut may be prevented from occurring in the sidewall of the metal pattern in the wet etching process, so that the metal pattern may be formed to have a substantially vertical sidewall profile. As a result, it is possible to implement circuit wiring having a uniform and fine line width without undercutting using existing wet etching equipment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described below. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are being provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout. Also, an element or layer is referred to as "on" or "on" of another element or layer by interposing another layer or other element in the middle as well as directly above the other element or layer. Include all cases.

Hereinafter, an etching solution according to an embodiment of the present invention will be described.

The etchant contains ferric chloride (FeCl ₃ ) and triazole type compounds. Ferric chloride is contained in the aqueous solution and serves as a stock agent for the metal film, for example, the copper film. Ferric chloride has a good etching force in the vertical direction with respect to the metal film and an excellent etching rate. To have a better etching power, the ferric chloride may have a concentration of 5 to 25% in the total etching solution. When the concentration of ferric chloride is less than 5%, not only the etching rate is lowered but also the adjustment of the etching direction is not easy. Meanwhile, in addition to ferric chloride, a strong acid, for example, hydrochloric acid, sulfuric acid, or nitric acid, may be included in the etching solution to further improve the etching power.

The triazole-based compound is etched and reacts with the metal remaining in the etchant to contribute to the formation of an organic metal complex. The metal complex containing the triazole-based compound is adsorbed on sidewalls of the exposed metal film during the etching process of the metal film to form an etch inhibiting film. An etch inhibiting layer formed of the complex may prevent the etching solution from penetrating into the metal film sidewalls. That is, the etch inhibiting film suppresses lateral etching and contributes to the progress of vertical etching. The triazole-based compound may be composed of at least one selected from the group consisting of benzotriazole (BTA) and derivatives thereof. Derivatives thereof may be at least one group consisting of benzotriazole carboxylic acid, sodium benzotriazole and sodium tolytriazole. In addition, the triazole-based compound may be contained at a concentration of 0.3% to 1%. When the concentration of the triazole compound is less than 0.3%, the lateral etching prevention function is remarkably reduced, and when the concentration of the triazole compound is greater than 1% , excessive inhibition of etching occurs, thereby decreasing the etching rate.

Meanwhile, a surfactant may be further contained in the etchant to disperse the above-described triazole-based metal complex as a crystal in a stable state. The surfactant may contain at least one moiety consisting of an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant. The amphoteric surfactant may contain at least one of a group consisting of carboxybetaine type alkylbetaine, fatty acid amidopropylbetaine, and alkylesters. The nonionic surfactant may be composed of at least one selected from the group consisting of reoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxypropylene and amine oxide. The cationic surfactant may also contain at least one of the group consisting of dimethylalkylamine, cetyltrimethylammonium chloride and distearyldimethylammonium chloride. The surfactant may be contained at a concentration of 1.0 to 3.0%. When the concentration of the surfactant is less than 1.0%, low surface tension, low wettability characteristics are induced, and bubble generation may not be easy. In addition, the etching characteristics in the vertical direction of the etching solution may be lowered. On the contrary, when it exceeds 3.0%, bubbles are excessively generated in the etching solution, which may cause difficulty in the etching solution and the etching process.

In addition, in order to prevent the surfactant from being deformed by reaction with oxygen in the air due to heat or mechanical friction for a long time, or the crosslinking reaction in the surfactant, the molecular weight and structure of the surfactant are prevented from being oxidized. More stabilizers may be added. In addition, the antioxidant stabilizer can prevent the generation of radicals in the etchant, and can suppress the chain propagation by hydroperoxide (hydroperoxide). Antioxidant stabilizers may contain at least one of a group consisting of phenolic, amine-based compounds, phosphorus-containing compounds, sulfur-containing compounds, and butylhydrooxyanisole (BHA). Antioxidant stabilizers may be included at a concentration of 5 to 20 ppm. If the concentration of the antioxidant stabilizer is less than 5ppm, the function of the surfactant may be reduced in a short time because it does not become a function of preventing degradation of the surfactant.

In addition, various other additives well known to those skilled in the art may be selected and used to improve the etching performance of the etchant according to an embodiment of the present invention.

The above-mentioned etching solution may be composed of residual amount of deionized water together with the above-mentioned ingredients, and the etching solution may be, for example, such that the triazole-based compound, the surfactant, and the antioxidant stabilizer are sufficiently mixed in the ferric chloride solution. It can be prepared by mixing over time. In addition to this, the aqueous solution of the above-described components may be prepared by mixing each other, and then mixing them, but the preparation method is not limited thereto. The mixing order is not particularly limited either.

Hereinafter, referring to FIGS. 2 to 4, a method of forming metal wires using an etchant according to an embodiment of the present invention as described above will be described. 2 to 4 are cross-sectional views illustrating a method of forming metal wirings performed using an etchant according to an embodiment of the present invention.

Referring to FIG. 2, a metal film 120 having a mask pattern 130 is deposited on a substrate, for example, an insulating substrate 110. In this case, the substrate may be a rigid circuit board or a flexible circuit board. The rigid circuit board may be, for example, a printed circuit board (PCB), and the flexible circuit board may be, for example, a flexible PCB (FPC), a flexible rigid PCB (FRPCB), a ceramic substrate, or the like. May be, but is not limited thereto. The substrate may be used as a package substrate, a substrate for a multi-chip module, a general motherboard, but is not limited thereto. Substrate is an insulating water formed of a polyimide, a glass fiber reinforced plastic (FRP), bisaleimide triazine (BT), poly phenylene ether (PPE), poly phenylene oxide (PPO) resin, etc. under the metal film 120 It may have a stratum layer, and in this specification, the term insulating substrate 110 is used. The metal film 120 may be, for example, a copper film or an aluminum film, but is preferably adopted as the copper film in order to have good conductivity. In addition, the mask pattern 130 performs a patterning process on the metal film 120 to contribute to transferring the same pattern as the mask pattern 130. The mask pattern 130 is formed of a material film having a wet etching selectivity with respect to the metal film 120, and may be typically formed of a photoresist, a silicon nitride film, and a silicon oxide film.

Referring to FIG. 3, a wet etching process is performed on the metal layer 120 with the above-described etching solution 140 using the mask pattern 130 as an etching mask. As described above, the etching solution 140 may contain a strong acid such as ferric chloride, hydrochloric acid, a triazole compound, a surfactant, an antioxidant stabilizer, and a residual amount of pure water. Specific components constituting the etchant and its concentration are described above and will be omitted. The wet etching process using the etchant 140 may be performed by various known methods. For example, at least one nozzle is installed on the insulating substrate 110 to spray toward the insulating substrate 110 through the nozzles. It can be performed as. In this case, the injection pressure may be set to 1 to 5 kg / cm ² , the temperature involved in the etching process may be adjusted to 20 to 50 ℃. When the etching progress temperature exceeds 50 ° C., the function of the surfactant may be drastically lowered by thermal decomposition of the surfactant.

Through the aforementioned method, the ferric chloride and hydrochloric acid contained in the etching solution 140 may etch the exposed metal film 120 between the mask patterns 130. In this case, as shown in the drawing, the metal film 120 exposed in the wet etching process is etched while being recessed in the vertical direction, and the etched metal ions may be etched with ferric chloride in the etching solution 140. React to form a metal chloride film.

Specifically, the case where the metal film 120 is formed of copper will be described as an example. The copper ions remaining in the etchant 140 by etching the metal film 120 may react with ferric chloride to form cuprous chloride during etching. Cuprous chloride may be reacted with hydrochloric acid to form cupric chloride. Subsequently, the cupric chloride reacts with a triazole-based compound such as benzotriazole, which is contained in the etchant 140, to form a triazole-based copper complex, which can be brought into a stable state by the action of a surfactant. . This triazole-based copper complex can be seen to be better formed near the sidewalls of the exposed metal film 120 than near the bottom surface to be etched. This is presumed to be due to the short time that the etchant 140 stays on the bottom surface and the time for reacting the components of the etchant 140 with copper is not sufficient.

The triazole-based copper complex repeats the adsorption and growth processes along sidewalls exposed in the etching process to form the etch inhibiting layers 122 having a thin thickness. On the other hand, the triazole-based copper complex adsorbed in a small amount on the bottom surface may be peeled off and removed by the injection pressure and the liquid flow of the etchant 140. As a result, the etch inhibiting layers 122 are formed only on the sidewalls of the metal layer 120 exposed during the etching process to prevent the etching solution 140 from penetrating into the metal layer 120 under the mask pattern 130. The undercut can be prevented. In addition, the main direction of the wet etching may be controlled to be vertical due to the etching suppression layers 122.

 Referring to FIG. 4, the wet etching is performed until the bottom surface of the insulating substrate 110 is exposed to form the metal patterns 124. Accordingly, the etch stop layers 122 may be formed on the entire sidewalls of the metal patterns 124. As a result, the metal wires 126 composed of the metal pattern 124 and the etching suppression layer 122 can be completed. After the etching process is completed, the mask pattern 130 is removed. When the mask pattern 130 is formed of photoresist, the photoresist pattern may be removed through an ashing process.

The metal wires 126 formed using the etchant according to the present exemplary embodiment may be manufactured without the occurrence of an undercut, and may be formed to have almost no difference between the upper and lower portions, and may have a vertical width and have a uniform width. have. Therefore, the etching liquid of this embodiment is suitable for the manufacturing process of the metal wiring in which high integration degree is calculated | required.

Hereinafter, referring to FIG. 5, a circuit board including metal wires manufactured by using an etchant according to an exemplary embodiment of the present invention will be described. 5 is a cross-sectional view of a circuit board manufactured using an etchant according to an embodiment of the present invention.

The circuit board 200 may include wirings stacked in at least one layer therein. Specifically, the first metal wirings 220a having a predetermined pattern on the first insulating substrate 210 and both sides thereof may be formed. 220b). The first insulating substrate 210 may be substantially the same substrate as the insulating substrate described with reference to FIG. 2. The first metal wires 220a and 220b may be formed of power wires, signal wires, and ground wires according to the function of the designed circuit. Accordingly, the first upper metal lines 220a and the first lower metal lines 220b constituting the first metal lines may be different from each other, and each of them may be formed in various arrangements. The first metal wires 220a and 220b may be disposed only on one side, unlike those shown in the drawing. Each of the first metal wires 220a and 220b includes first metal patterns 222a and 222b and first etch inhibitor layers 224a and 224b positioned on sidewalls thereof. The first metal wires 220a and 220b may be formed using the etchant according to the present embodiment and the method described with reference to FIGS. 2 to 4. In the case of using the etching solution of the present embodiment, the metal complex containing the triazole-based compound as one component of the etching solution is composed of the first etching suppressing films 224a and 224b. For example, when the copper pattern and the benzotriazole are used as the metal patterns 222a and 222b and the triazole-based compound, the first etching suppression layers 224a and 224b may be formed of a benzotriazole copper complex. Can be.

Second insulating substrates may be disposed on both surfaces of the first insulating substrate 210 having the first metal wires 220a and 220b. The second insulating substrates may include a second upper insulating substrate 230a and a second lower insulating substrate 230b. Unlike the first insulating substrate 210, the second insulating substrates 230a and 230b may be formed only of an insulating resin layer such as polyimide described with reference to FIG. 2. The second insulating substrates 230a and 230b may be formed through conventional methods known to those skilled in the art. Meanwhile, the wiring holes 240 may pass through the first insulating substrate 210 and the second upper and lower insulating substrates 230a and 230b. The conductive lines 242 may be disposed along the sidewalls of the wiring holes 240, and the conductive lines 242 may be positioned to be electrically connected to the first metal lines 220a and 220b. The conductive lines 242 may be formed of, for example, a copper film. In this case, the conductive lines 242 may be formed using a method such as electrolytic plating or electroless plating.

Second metal wires 250a and 250b may be provided on the second upper and lower insulating substrates 230a and 230b to be electrically connected to the conductive lines 242. The second metal wires 250a and 250b may have second upper metal wires 250a and second lower metal wires 250b. The second upper metal wires 250a may be formed in a pad shape having a predetermined shape so that the semiconductor chip manufactured separately may be mounted, and these may be classified into a power pad, a signal pad, and a ground pad. The second lower metal lines 250b may be electrically connected to the outside through the solder bumps 260, and may transmit an electrical signal to the semiconductor chip through the conductive lines 242. Like the first metal wires 220a and 220b, the second metal wires 250a and 250b may include second metal patterns 252a and 252b and second etching suppression layers 254a and 254b. . The second metal wires 250a and 250b may be manufactured using the etchant according to the present embodiment substantially the same as the method of manufacturing the first metal wires 220a and 220b. In this case, second etch inhibiting layers 254a and 254b formed of triazole-based metal complexes are provided on sidewalls of the second metal patterns 252a and 252b. Meanwhile, the coating layers 256a and 256b may be formed on the second insulating substrates 230a and 230b having the second metal lines 250a and 250b to prevent external exposure of the second metal lines 250a and 250b. This can be arranged.

In the above, the circuit board including the metal wires stacked in four layers has been described as an example, but the inventive concept may be applied to a circuit board including the metal wires having an even layer that is not limited thereto. .

Hereinafter, the present invention will be described in more detail through experimental examples. However, the following experimental examples are for illustrating the present invention, it should be understood that the present invention is not limited by the following experimental examples.

Experimental Examples

Experimental Example 1

(1) Preparation of etching solution

To a ferric chloride solution (ferric chloride: 2 mol / L, hydrochloric acid: 3 mol / L), benzotriazole was added at a concentration of 1% as a triazole compound, and 1.5% of amine oxide as a nonionic surfactant was added. An etchant was prepared by adding in concentration.

(2) photoresist film pattern formation

After forming a copper film having a thickness of 8 μm on a substrate with a polyimide resin layer having a width of 100 mm on the substrate, a photoresist is applied on the copper film, and a photomask having a shape of a fine circuit pattern through an exposure and development process. A photoresist substrate having a pattern was prepared. In this case, the line width of the photoresist pattern was 25 μm, and the space between the photoresist patterns was adjusted to 20 μm.

(3) etching and peeling of photoresist pattern

A substrate having a photoresist pattern was placed in a horizontal etching apparatus of a top-down two-row spray method, and the etching solution was sprayed toward the substrate under the following conditions.

Tip distance: 200mm, Injection pressure: 3kg / cm ² ,

Etching Temperature: 48 ℃, Etching Time: 50sec

After etching under the above-described conditions, a copper wiring having a fine circuit pattern was manufactured by removing the photoresist pattern with acetone or caustic soda solution after washing with pure water.

Experimental Example 2

A triazole-based compound was mixed with the ferric chloride solution at the concentration of (1) of Experimental Example 1, but an etching solution without adding a surfactant was prepared, and copper wiring was carried out under the same conditions as mentioned in (3) of Experimental Example 1. Was prepared.

Experimental Example 3

Triazole-based compound was mixed with the ferric chloride solution at the concentration of (1) of Experimental Example 1, and a surfactant was prepared by adding a surfactant (amine oxide concentration as a nonionic surfactant) at a concentration of 1.3%. Copper wirings were manufactured under the same conditions as mentioned in (3).

Experimental Example 4

The triazole-based compound was mixed with the ferric chloride solution at the concentration of (1) of Experimental Example 1, and a surfactant was added at a concentration of 1.1% to prepare an etching solution, and the conditions mentioned in (3) of Experimental Example 1 Copper wiring was similarly manufactured.

Experimental Example 5

Triazole-based compound was mixed in the ferric chloride solution at the concentration of (1) of Experimental Example 1, and the surfactant was added at a concentration of 1.9% to prepare an etching solution, and copper was prepared in the same manner as in (3) of Experimental Example 1. Wiring was prepared.

Experimental Example 6

The triazole compound was mixed with the ferric chloride solution at the concentration of (1) of Experimental Example 1, and the surfactant was added at a concentration of 1.7% to prepare an etching solution, and copper was prepared in the same manner as in (3) of Experimental Example 1 Wiring was prepared.

Experimental Example 7

Triazole-based compound was mixed in the ferric chloride solution at the concentration of (1) of Experimental Example 1, and the surfactant was added at a concentration of 2.5% to prepare an etching solution, and copper was prepared in the same manner as in (3) of Experimental Example 1. Wiring was prepared.

Experimental Example 8

Triazole-based compound was mixed in the ferric chloride solution at the concentration of (1) of Experimental Example 1, and a surfactant was added at a concentration of 3.0% to prepare an etching solution, and copper was prepared in the same manner as in (3) of Experimental Example 1. Wiring was prepared.

Experimental Example 9

Benzotriazole and surfactant were added to the ferric chloride solution at concentrations of 0.8% and 1.5%, respectively, to prepare an etching solution, and copper wirings were prepared in the same manner as in (3) of Experimental Example 1.

Experimental Example 10

Benzotriazole and surfactant were added to the ferric chloride solution at concentrations of 0.6% and 1.5%, respectively, to prepare an etching solution, and copper wirings were prepared in the same manner as in (3) of Experimental Example 1.

Experimental Example 11

Benzotriazole and a surfactant were added to the ferric chloride solution at concentrations of 0.4% and 1.0%, respectively, to prepare an etching solution, and copper wiring was prepared in the same manner as in (3) of Experimental Example 1.

Experimental Example 12

Benzotriazole and surfactant were added to the ferric chloride solution at concentrations of 0.3% and 1.0%, respectively, to prepare an etching solution, and copper wirings were prepared in the same manner as in (3) of Experimental Example 1.

Experimental Example 13

A triazole-based compound and a surfactant were added to the ferric chloride solution at the concentrations of (1) of Experimental Example 1 to prepare an etching solution, and a copper pressure was prepared by setting the injection pressure to 1 kg / cm ² .

Experimental Example 14

A triazole-based compound and a surfactant were added to the ferric chloride solution at the concentrations of (1) of Experimental Example 1 to prepare an etching solution, and a copper wiring was prepared by setting the injection pressure to 2 kg / cm ² .

Experimental Example 15

A triazole-based compound and a surfactant were added to the ferric chloride solution at the concentrations of (1) of Experimental Example 1 to prepare an etching solution, and a copper wire was prepared by setting the spray pressure to 4 kg / cm ² .

Experimental Example 16

A triazole-based compound and a surfactant were added to the ferric chloride solution at the concentrations of (1) of Experimental Example 1 to prepare an etching solution, and a copper wiring was prepared by setting an injection pressure of 5 kg / cm ² .

Experimental Example 17

An etchant was prepared by adding a triazole compound and a surfactant to the ferric chloride solution at the concentrations of Experiment (1) and adding an antioxidant stabilizer (butylhydrooxyanisole) at a concentration of 5 ppm. Copper wirings were manufactured under the same conditions as described in Experimental Example (3).

Experimental Example 18

An etching solution was prepared by adding a triazole compound and a surfactant to the ferric chloride solution at the concentrations of (1) of Experimental Example 1, and adding an antioxidant stabilizer (butylhydrooxyanisole) at a concentration of 10 ppm. Copper wirings were manufactured under the same conditions as described in Experimental Example (3).

Experimental Example 19

An etching solution was prepared by adding a triazole compound and a surfactant to the ferric chloride solution at the concentrations of Experiment (1) and adding an antioxidant stabilizer (butylhydrooxyanisole) at a concentration of 15 ppm. Copper wirings were manufactured under the same conditions as described in Experimental Example (3).

Experimental Example 20

An etching solution was prepared by adding a triazole compound and a surfactant to the ferric chloride solution at the concentrations of (1) of Experimental Example 1, and adding an antioxidant stabilizer (butylhydrooxyanisole) at a concentration of 20 ppm. Copper wirings were manufactured under the same conditions as described in Experimental Example (3).

TABLE 1

Triazole Compound (%) Surfactants (%) Antioxidant Stabilizer (ppm) Etching liquid injection pressure (kg / cm2) Etching temperature (C) result Top / Bottom Ratio (%) Experimental Example 1 1.0 1.5 - 3 48 85.6 Excellent 2 1.0 - - 3 48 48.0 Building 3 1.0 1.3 - 3 48 78.8 Excellent 4 1.0 1.1 - 3 48 70.4 Good 5 1.0 1.9 - 3 48 76.3 Good 6 1.0 1.7 - 3 48 78.4 Good 7 1.0 2.5 - 3 48 65.8 Inadequate 8 1.0 3.0 - 3 48 63.5 Inadequate 9 0.8 1.5 3 48 89.0 Excellent 10 0.6 1.5 - 3 48 57.4 Building 11 0.4 1.0 - 3 48 51.1 Building 12 0.3 1.0 - 3 48 54.9 Building 13 1.0 1.5 - One 48 78.2 Good 14 1.0 1.5 - 2 48 84.3 Excellent 15 1.0 1.5 - 4 48 74.8 Good 16 1.0 1.5 - 5 48 70.7 Good 17 1.0 1.5 5 3 48 76.6 Good 18 1.0 1.5 10 3 48 76.1 Good 19 1.0 1.5 15 3 48 70.8 Good 20 1.0 1.5 20 3 48 63.5 Building

In the evaluation item of [Table 1], as shown in FIG. 4, the top / bottom ratio means the upper width T of the bottom width B of the copper wiring. As the top / bottom ratio is closer to 100%, not only the width of the etched copper wiring is formed uniformly, but also the vertical sidewall profile close to the bottom without the undercut. As shown in Table 1, when comparing the experimental examples while adjusting the concentration of benzotriazole to 0.3 to 1.0%, Top / bottom ratio appears to be high when 0.7 or more and 1.0% or less. When the surfactant concentration is 1.0%, the top / bottom ratio is low due to the low surface tension and low dispersion of the complex. In addition, it is assumed that the antioxidant stabilizer interferes with the formation of the etch inhibiting film when it exceeds 20 ppm.

On the other hand, Figure 6a is a SEM (Scanning Electron Microscope) of the metal wiring fabricated according to the conventional wet etching, Figure 6b is a SEM photo of the fabricated metal wiring according to an embodiment of the present invention. 7A to 7C are micrographs showing top, bottom, and cross-sections of metal wires fabricated using an etchant according to an embodiment of the present invention, respectively. The micrographs of FIGS. 7A to 7C are photographs enlarged at 500 magnification.

The etching in FIG. 6a was performed on the copper film with an etchant prepared by mixing ferric chloride and hydrochloric acid excluding the triazole compound and the surfactant. Specifically, the conventional etchant of Figure 6a was prepared by mixing 2 mol / L ferric chloride and 3 mol / L hydrochloric acid in pure water. 6B and 7A to 7C illustrate the copper wires etched by the etching solution and the conditions of Experimental Example 14. Specifically, the triazole-based compound and the surfactant were added to the ferric chloride solution at concentrations of 1% and 1.5% to prepare an etching solution, and the injection pressure was set at ² kg / cm ² .

Comparing them, in the copper wiring of FIG. 6A, an undercut is formed at the upper end so that the difference between the upper and lower widths is prominent. However, the formation of the undercut is significantly reduced in the copper wiring of FIG. Smaller than the wiring can be seen. 7A to 7C, it can be observed that the bottoms of the copper wires (lead lines) of FIG. 7A and the upper portions of the copper wires of FIG. 7B have substantially the same width. In addition, in the cross-sections of the copper wirings of FIG. 7C, the widths of the upper and the bottom may be substantially the same, and the line widths of the wirings may be uniform. That is, by using the etchant according to the present invention, the metal lines can be formed with a high top / bottom ratio.

1A to 1C are cross-sectional views illustrating a method of forming a metal wire according to a conventional wet etching method.

2 to 4 are cross-sectional views illustrating a method of forming metal wirings performed using an etchant according to an embodiment of the present invention.

5 is a cross-sectional view of a circuit board manufactured using an etchant according to an embodiment of the present invention.

6A is a scanning electron microscope (SEM) photograph of a metal wiring manufactured by a conventional wet etching, and FIG. 6B is a SEM photograph of a metal wiring manufactured using an etchant according to an embodiment of the present invention.

7A to 7C are micrographs showing top, bottom, and cross-sections of metal wires fabricated using an etchant according to an embodiment of the present invention, respectively.

Claims (33)

An etchant containing ferric chloride (FeCl ₃ ) and a triazole type compound. The method of claim 1, The triazole-based compound is an etching solution contained in a concentration of 0.3 to 1.0%. The method of claim 1, The ferric chloride is an etching solution having a content of 5 to 25%. The method of claim 1, The triazole-based compound contains at least one selected from the group consisting of benzotriazole (BTA), benzotriazole carboxylic acid, sodium benzotriazole (sodium BTA), and potasium tolytriazole. Etch solution. The method of claim 1, Etching solution further containing a surfactant in the etching solution. The method of claim 5, The surfactant is an etchant containing at a concentration of 1.0 to 3.0%. The method of claim 5, The surfactant is an etchant containing at least one selected from the group consisting of an amphoteric surfactant, a cationic surfactant and a nonionic surfactant. The method of claim 7, wherein The amphoteric surfactant is an etchant containing at least one selected from the group consisting of carboxybetaine type alkyl betaine, fatty acid amidopropyl betaine and alkyl ester. The method of claim 7, wherein The nonionic surfactant is an etching solution containing at least one selected from the group consisting of reoxyethylene nonyl phenyl ether, polyoxyethylene stearyl ether, polyoxyethylene, polyoxypropylene and amine oxide. The method of claim 7, wherein The cationic surfactant is an etchant containing at least one selected from the group consisting of dimethylalkylamine, cetyltrimethylammonium chloride and distearyldimethylammonium chloride. The method of claim 1, An etchant further comprising an antioxidant stabilizer in the etchant. The method of claim 11, The antioxidant stabilizer is an etching solution contained in a concentration of 5 to 20ppm. The method of claim 11, The antioxidant stabilizer is an etching solution containing at least one selected from the group consisting of phenolic, amine-based compounds, phosphorus-containing compounds, sulfur-containing compounds and butyl hydrooxyanisole (BHA). Forming a metal film having a mask pattern on the substrate, Forming a metal wiring by etching the metal film using the mask pattern as an etching mask, and forming metal wiring using an etchant containing ferric chloride (FeCl 3) and a triazole-type compound during the etching Way. The method of claim 14, The triazole-based compound is a metal wiring forming method contained in a concentration of 0.3 to 1.0%. The method of claim 14, The ferric chloride has a content of 5 to 25% metal wiring forming method. The method of claim 14, The triazole-based compound contains at least one selected from the group consisting of benzotriazole (BTA), benzotriazole carboxylic acid, sodium benzotriazole (sodium BTA), and potasium tolytriazole. Metal wiring formation method. The method of claim 14, Metal wiring forming method further containing a surfactant in the etching solution. The method of claim 18, The surfactant is a metal wiring forming method which is contained in a concentration of 1.0 to 3.0%. The method of claim 18, And the surfactant contains at least one selected from the group consisting of amphoterci surfactants, cationic surfactants, and nonionic surfactants. The method of claim 20, And the amphoteric surfactant comprises at least one selected from the group consisting of carboxybetaine type alkyl betaine, fatty acid amidopropyl betaine, and alkyl ester. The method of claim 20, And the nonionic surfactant contains at least one selected from the group consisting of lyoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene, polyoxypropylene and amine oxide. The method of claim 20, Wherein said cationic surfactant contains at least one selected from the group consisting of dimethylalkylamine, cetyltrimethylammonium chloride and distearyldimethylammonium chloride. The method of claim 14, The metal wiring forming method further comprising an antioxidant stabilizer in the etchant. The method of claim 24, The antioxidant stabilizer is metal wiring forming method is contained in a concentration of 5 to 20ppm. The method of claim 24, The antioxidant stabilizer is a metal wiring forming method containing at least one selected from the group consisting of phenolic, amine-based compound, phosphorus-containing compound, containing sulfur-based compound and butylhydrooxyanisole (BHA). The method of claim 14, The metal wiring is formed to include an etch inhibiting film on a metal pattern and sidewalls of the metal pattern, wherein the etch inhibiting film is formed on sidewalls of the metal pattern exposed under the mask pattern while etching the metal film. How to form metal wiring. The method of claim 14, And the metal film is formed of a film containing copper. The method of claim 14, The etching is a metal wire forming method is performed at a temperature of 20 to 50 ℃. The method of claim 14, The etching is performed by spraying the etchant toward the substrate, wherein the injection pressure is set to 1 to 5 kg / cm ² metal wiring. A first metal wire having a first metal pattern on at least one side of the first insulating substrate and a first etch inhibiting film on sidewalls of the first metal pattern; The first etch inhibiting film is formed of a metal complex containing a triazole-based compound. The method of claim 31, wherein A second insulating substrate positioned on at least one side of the first insulating substrate having the first metal wiring and a second metal wiring positioned on the second insulating substrate, And the second metal wire has a second etch inhibiting film on a second metal pattern and sidewalls of the second metal pattern, and the second etch inhibiting film is formed of a metal complex containing a triazole-based compound. 33. The method of any of claims 31 and 32, The metal wires are formed using an etchant containing the ferric chloride (FeCl ₃ ) and a triazole type compound, and the etch inhibiting layer is formed on sidewalls of the metal patterns exposed during the etching of the metal layer and the etching patterns. A circuit board formed by reacting with a triazole compound.

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