KR20180068545A - Etching solution composition and method of etching using the same - Google Patents

Abstract

The present invention relates to an etching solution composition which comprises: hydrogen peroxide; a phosphoric acid or a phosphate-based compound; a sulfate-based compound; a fluorine-based compound; a chelate agent; and an anticorrosive agent. The present invention improves an etching speed and an etching profile.

Description

TECHNICAL FIELD [0001] The present invention relates to an etching solution composition and an etching method using the etching solution composition.

The present invention relates to an etchant composition for etching a single film or multiple films containing copper and an etching method using the same.

Generally, a process of forming a circuit pattern on a substrate during semiconductor device fabrication includes a metal film forming process by sputtering or the like; A photoresist forming step in a selective region by photoresist application, exposure and development; And an etching process. The etching process is a process of leaving a metal film in a selective region using a photoresist as a mask, and dry etching using plasma or wet etching using an etching composition is used.

Korean Patent Publication No. 2007-0055259 discloses an etchant solution of a copper molybdenum alloy film containing hydrogen peroxide, organic acid, and a phosphate compound in relation to the etchant composition. However, when the etching solution is applied to a thick film of a copper-based metal film, there is a problem that a taper angle is increased due to a phosphate compound, thereby causing defects in the subsequent process.

In addition, an etchant composition containing hydrogen peroxide, a phosphate compound, and a sulfate compound has been disclosed. The etchant composition may exhibit an improved etch rate as it comprises a high content (e.g., 1 wt% or more) of phosphate compound and sulfate compound. However, when the etchant is stagnated for a certain period of time and then reused, a high concentration of metal remains in the etchant, resulting in a high taper angle resulting in a high failure rate. Therefore, . Further, in order to control the physical properties of the etchant composition, the content of other additives is also increased, resulting in poor economical efficiency.

Therefore, there is a demand for an etchant composition which is excellent in etching speed and etching profile and can secure economical efficiency.

An object of the present invention is to provide an etchant composition which is excellent in an etching rate, an etching profile, and the like, and which can secure economical efficiency.

The present invention also provides an etching method using the etching composition.

In order to solve the above-mentioned problems, Phosphoric acid or phosphate compounds; Sulfate compounds: fluorine compounds; Chelating agents; And an anticorrosive agent, wherein the phosphoric acid or phosphate compound is contained in an amount of 0.05 to 0.1 part by weight based on 100 parts by weight of the etchant composition, and the sulfate compound is contained in an amount of 0.1 to 0.4 part by weight do.

The present invention also provides an etching method comprising etching a metal film on a substrate with the etchant composition.

Since the etchant composition of the present invention contains a phosphoric acid or phosphate compound and a sulfate compound at an optimum ratio, they can exhibit a rapid etching rate and an excellent etching profile (for example, taper angle, CD bias, etc.) . In addition, the present invention can ensure economical efficiency of the etching composition by containing the phosphoric acid or phosphate compound and the sulfate compound in a low amount.

FIGS. 1 and 2 are scanning electron micrographs showing etching characteristics according to Example 1 and Comparative Example 7. FIG.

Hereinafter, the present invention will be described.

One. Etchant  Composition

The etching solution composition of the present invention includes hydrogen peroxide, a phosphoric acid or phosphate compound, a sulfate compound, a fluorine compound, a chelating agent and a corrosion inhibitor.

The hydrogen peroxide contained in the etchant composition of the present invention serves to oxidize the metal film.

Although the content of hydrogen peroxide is not particularly limited, it is preferably 15 to 25 parts by weight based on 100 parts by weight of the etching solution composition. If the amount of the hydrogen peroxide is less than 15 parts by weight, the metal film may not be sufficiently etched due to insufficient oxidizing ability. If the amount exceeds 25 parts by weight, the etching rate of the metal film may become excessively high, May increase the risk of explosion.

The phosphoric acid or phosphate compound contained in the etchant composition of the present invention controls the etching rate of the metal film and the taper angle of the metal film.

The phosphate compound is not particularly limited, but may be selected from the group consisting of sodium phosphate NaH ₂ PO ₄ , Na ₂ HPO ₄ , potassium phosphate KH ₂ PO ₄ , potassium phosphate K ₂ HPO ₄ , It is preferably at least one selected from the group consisting of ammonium primary phosphate ((NH ₄ ) H ₂ PO ₄ ) and ammonium phosphite ((NH ₄ ) ₂ HPO ₄ ).

The content of the phosphoric acid or phosphate compound is 0.05 to 0.1 part by weight based on 100 parts by weight of the etchant composition. If the content of the phosphoric acid or phosphate compound is less than 0.05 part by weight, the etching rate of the metal film may be lowered. If it exceeds 0.1 part by weight, the etching rate of the metal film may become excessively high or the taper angle of the metal film may become too large. In addition, the use of an excessive amount of phosphoric acid or phosphate compound increases the content of the additive to control the amount of the phosphoric acid or phosphate compound, thereby decreasing the economical efficiency of the etchant composition.

The sulfate compound contained in the etching solution composition of the present invention plays a role of controlling the etching rate of the metal film and the taper angle of the metal film. Examples of the sulfate compound include, but are not limited to, potassium hydrogen sulfate (KHSO ₄ ), sodium hydrogen sulfate (NaHSO ₄ ), ammonium hydrogen sulfate ((NH ₄ ) HSO ₄ ), potassium sulfate (K ₂ SO ₄ ) ₂ SO ₄ ) and ammonium sulfate ((NH ₄ ) ₂ SO ₄ ).

The content of the sulfate compound is 0.1 to 0.4 parts by weight based on 100 parts by weight of the etchant composition. If the content of the sulfate compound is less than 0.1 parts by weight, the etching rate of the metal film is lowered and the taper angle of the metal film becomes too large, which may cause problems in the manufacturing process. If the content exceeds 0.4 parts by weight, As the metal concentration increases, the CD bias may become excessively large. Also, the use of an excessive amount of a sulfate compound increases the content of an additive for controlling the amount of the sulfate compound, which may reduce the economical efficiency of the etchant composition.

As described above, the etching solution composition of the present invention contains the phosphoric acid or phosphate compound and the sulfate compound in a specific ratio, that is, 0.05 to 0.1 part by weight and 0.1 to 0.4 part by weight, respectively, The etching rate is fast even when the etching rate is relatively low, and an excellent etching profile can be obtained. In addition, even when the etching solution composition has an increased metal concentration in the etchant composition when the etchant composition is stuck for a predetermined time and then reused due to the specific ratio, the taper angle of the metal film can be maintained constant and the replacement period of the etchant composition can be increased, .

Specifically, the etchant composition of the present invention contains 0.15 to 0.5 parts by weight, preferably 0.2 to 0.35 parts by weight, of a phosphoric acid or phosphate compound and a sulfate compound. The total etching amount of the phosphoric acid or phosphate compound and the sulfate compound is 0.15 to 0.5 part by weight, the etchant composition of the present invention has a high etch rate and a data angle in the range of 40 to 60 ° and a CD bias change of less than 0.2 μm , And it is possible to exhibit excellent eclipseability up to a cumulative number of substrate processing of 7000 ppm.

The fluorine-based compound contained in the etchant composition of the present invention serves to remove residues of the metal film that may occur during the etching process of the metal film. The fluorine-based compound is not particularly limited, but may be selected from the group consisting of hydrogen fluoride (HF), sodium fluoride (NaF), sodium hydrogen fluoride (NaHF ₂ ), ammonium fluoride (NH ₄ F), acid ammonium fluoride (NH ₄ HF ₂ ) It is preferably at least one selected from the group consisting of ammonium (NH ₄ BF ₄ ), potassium fluoride (KF), potassium hydrogen fluoride (KHF ₂ ) and aluminum fluoride (AlF ₃ ).

The content of such a fluorine-based compound is not particularly limited, but is preferably 0.01 to 1 part by weight based on 100 parts by weight of the etchant composition. If the content of the fluorine-based compound is less than 0.01 part by weight, it may be difficult to effectively remove the residue of the metal film. If the amount is more than 1 part by weight, the substrate on which the metal film is formed or the insulating film may be damaged.

The chelating agent contained in the etchant composition of the present invention binds ligands with metal ions generated during the etching of the metal film to inactivate the metal ions, thereby inhibiting the decomposition reaction of hydrogen peroxide contained in the etchant composition.

The chelating agent is not particularly limited and may be selected from the group consisting of iminodiacetic acid, diglycolic acid, thioglycolic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, Diethylenetrinitrileacetic acid, aminotris (methylenephosphonic acid), (1-hydroxyethane-1,1-diyl) bis (phosphonic acid), (1-hydroxyethane- 1,1-diyl bis (phosphonic acid), ethylenediamine tetra (methylene phosphonic acid), diethylenetriamine penta (methylene phosphonic acid), diethylenetriamine penta (methylene phosphonic acid) It is preferably at least one selected from the group consisting of alanine, glutamic acid, aminobutyric acid and glycin.

The content of the chelating agent is not particularly limited, but is preferably 1 to 5 parts by weight based on 100 parts by weight of the etching solution composition. If the amount of the chelating agent is less than 1 part by weight, it may be difficult to control the decomposition reaction of hydrogen peroxide. If the amount is more than 5 parts by weight, the CD bias may become larger as the concentration of metal ions increases in the etchant composition.

The corrosion inhibitor contained in the etchant composition of the present invention serves to control the etching rate of the metal film. Examples of the corrosion inhibitor include, but are not limited to, furane, thiophene, pyrrole, oxazole, imidazole, methylimidazole, pyrazole, Triazole, aminotriazole, tetrazole, 5-aminotetrazole, methyltetrazole, piperazine, methylpiperazine, and the like. , Hydroxyethylpiperazine, pyrrolidine, alloxan, benzofurane, benzothiophene, indole, benzimidazole, benzpyrazole, It is preferably at least one selected from the group consisting of benzopyrazole, tolutriazole, hydrotolutriazole and hydroxytolutriazole.

The content of such a corrosion inhibitor is not particularly limited, but is preferably 0.01 to 1 part by weight based on 100 parts by weight of the etchant composition. If the content of the corrosion inhibitor is less than 0.01 part by weight, excessive etching may occur or the etching profile (CD bias, taper angle) may become poor. If the amount exceeds 1 part by weight, Time can be long.

In addition, the etchant composition of the present invention may further comprise stabilizers that stabilize the above components. Specifically, the stabilizer controls the decomposition reaction of hydrogen peroxide which may occur as the concentration of metal ions in the etchant composition increases due to the repeated etching process. The stabilizer may include alcohols, glycols, amines, and the like, and the content thereof may be 0.1 to 5 parts by weight based on 100 parts by weight of the etchant composition.

The etchant composition of the present invention may further comprise a solvent for dissolving or dispersing the above components. The solvent is not particularly limited, but may be water, ionized water, pure water, or ultrapure water.

2. Etching  Way

The present invention provides a method of etching a metal film using the above-described etchant composition, which will be described in detail as follows.

a) Substrate preparation

First, a substrate on which a metal film is formed is prepared. The substrate is not particularly limited as long as it is well known in the art, but it may be a glass substrate.

The method of forming the metal film on the substrate is not particularly limited as long as it is well known in the art. At this time, the metal film may be a copper film or a copper alloy film. Specifically, the metal film may be a single film of copper, a single film of an alloy of copper and molybdenum, a multiple film of single films of copper and molybdenum, or a multiple film of single films of copper and molybdenum have.

b) Etching

Next, the metal film is etched by contacting the above-mentioned etchant composition with the substrate on which the metal film is formed. At this time, when a metal circuit pattern is to be formed on the metal film through etching, a metal circuit pattern can be formed by forming a photoresist pattern on the metal film and contacting the metal film with the etchant composition.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  1 to 11]

The etchant compositions having the compositions shown in Tables 1 and 2 were prepared. The unit of each content is% by weight and adjusted to 100% by weight with ionized water.

ingredient Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Hydrogen peroxide 23.0 23.0 23.0 23.0 23.0 23.0 Phosphoric acid or phosphate compound (x) Phosphoric acid 0.1 0.1 0.1 0.05 0.05 0.05 Ammonium phosphate monobasic - - - - - - Sodium primary phosphate - - - - - - The sulfate compound (y) Potassium hydrogen sulphate 0.1 0.2 0.4 0.1 0.3 0.4 Ammonium sulfate - - - - - - Sodium sulfate - - - - - - Potassium sulfate - - - - - - Fluorine compound Ammonium fluoride 0.2 0.2 0.2 0.2 0.2 0.2 Chelating agent Iminodiacetic acid 3.0 3.0 3.0 3.0 3.0 3.0 Corrosion inhibitor Methylimidazole 0.7 0.7 0.7 0.4 0.4 0.4 Methyl tetrazole 0.1 0.1 0.1 0.1 0.1 0.1 Ion water Honey. Honey. Honey. Honey. Honey. Honey. (X + y) of phosphoric acid or phosphate compound and sulfate compound, 0.20 0.30 0.50 0.15 0.35 0.45

ingredient Example 7 Example 8 Example 9 Example 10 Example 11 Hydrogen peroxide 23.0 23.0 23.0 23.0 23.0 Phosphoric acid or phosphate compound (x) Phosphoric acid - - 0.05 0.05 0.05 Ammonium phosphate monobasic 0.05 - - - - Sodium primary phosphate - 0.05 - - - The sulfate compound (y) Potassium hydrogen sulphate 0.3 0.3 - - - Ammonium sulfate - - 0.3 - - Sodium sulfate - - - 0.3 - Potassium sulfate - - - - 0.3 Fluorine compound Ammonium fluoride 0.2 0.2 0.2 0.2 0.2 Chelating agent Iminodiacetic acid 3.0 3.0 3.0 3.0 3.0 Corrosion inhibitor Methylimidazole 0.4 0.4 0.4 0.4 0.4 Methyl tetrazole 0.1 0.1 0.1 0.1 0.1 Ion water Honey. Honey. Honey. Honey. Honey. (X + y) of phosphoric acid or phosphate compound and sulfate compound, 0.35 0.35 0.35 0.35 0.35

[ Comparative Example  1 to 7]

Each of the etchant compositions having the composition shown in Table 3 below was prepared. The unit of each content is% by weight and adjusted to 100% by weight with ionized water.

ingredient Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Hydrogen peroxide 23.0 23.0 23.0 23.0 23.0 23.0 23.0 Phosphoric acid or phosphate compound (x) Phosphoric acid 0.01 0.01 0.15 0.15 0.1 0.05 0.5 Ammonium phosphate monobasic - - - - - - - Sodium primary phosphate - - - - - - - The sulfate compound (y) Potassium hydrogen sulphate 0.1 0.4 0.1 0.35 0.05 0.45 0.5 Ammonium sulfate - - - - - - - Sodium sulfate - - - - - - - Potassium sulfate - - - - - - 0 Fluorine compound Ammonium fluoride 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Chelating agent Iminodiacetic acid 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Corrosion inhibitor Methylimidazole 0.4 0.4 0.7 0.7 0.7 0.4 1.2 Methyl tetrazole 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Ion water Honey. Honey. Honey. Honey. Honey. Honey. Honey. (X + y) of phosphoric acid or phosphate compound and sulfate compound, 0.11 0.41 0.25 0.5 0.15 0.5 1.0

[ Experimental Example  One]

A Cu / Mo alloy film (5000 Å / 100 Å) was deposited on the glass substrate, and then a photolithography process was performed to form a pattern to prepare a sample. Next, etching was performed using the etchant compositions prepared in the examples and comparative examples using a sprayable equipment (Mini-etcher). In order to confirm the etch characteristics, the cumulative number of Cu ions was 300 ppm and the total etch time was 7000 ppm, and the over etch was 100% based on EPD (End Point Detection) for the substrate. The measured results are shown in Table 4 below.

1. Etching speed: The EPD of the metal film was measured with a stopwatch and then the etching rate was calculated (when the measured value is in the range of 140 to 170 Å / s: ◯, in the case of less than 140 Å / s or more than 170 Å / s: ×).

2. Change in CD bias: CD bias change was analyzed by scanning electron microscope (SU-8010, manufactured by Hitachi, Ltd.) (when the measured value is 0.2 탆 or less: ∘, when it exceeds 0.2 탆: x).

3. Taper angle: The taper angle was analyzed by observation with a scanning electron microscope (SU-8010, manufactured by Hitachi, Ltd.) (when the measured value was in the range of 40 to 60 占 ◯, when it was less than 40 or more than 60 : X).

ingredient Etching rate CD bias change Taper angle 300 ppm 7000 ppm Example 1 ○ ○ ○ ○ Example 2 ○ ○ ○ ○ Example 3 ○ ○ ○ ○ Example 4 ○ ○ ○ ○ Example 5 ○ ○ ○ ○ Example 6 ○ ○ ○ ○ Example 7 ○ ○ ○ ○ Example 8 ○ ○ ○ ○ Example 9 ○ ○ ○ ○ Example 10 ○ ○ ○ ○ Example 11 ○ ○ ○ ○ Comparative Example 1 × × × ○ Comparative Example 2 × ○ × ○ Comparative Example 3 ○ ○ ○ × Comparative Example 4 × × ○ × Comparative Example 5 × ○ ○ × Comparative Example 6 ○ ○ ○ ×

Referring to Table 4, it can be seen that Examples 1 to 11 corresponding to the etching composition of the present invention have excellent evaluation results on the etching rate, CD bias change, and taper angle.

[ Experimental Example  2]

The time-dependent evaluation of the etchant composition was carried out through the following procedure. The CD bias change and the taper angle were measured during each process and are shown in Table 5 and FIGS. 1 and 2, respectively.

1. 300 ppm of Cu, 21 ppm of Mo and 9 ppm of Ti were dissolved in the etchant composition of Example 1 and Comparative Example 7,

Next, the metal powder was further dissolved so that the content of the metal ion was 3000 ppm of Cu, 210 ppm of Mo, and 90 ppm of Ti, and the mixture was maintained in a thermostat at 32 ° C and spray

3. Evaluation of etch after 6 hours

Next, the metal powder is further dissolved so that the content of the metal ion is 5000 ppm of Cu, 350 ppm of Mo and 150 ppm of Ti, and the mixture is maintained in a thermostat at 32 ° C and spray

5. Evaluation of etch after 6 hours

6. Finally, the metal powder is further dissolved so that the content of metal ions is 7000 ppm of Cu, 490 ppm of Mo and 210 ppm of Ti, and is maintained in a thermostat at 32 ° C and spray

7. Evaluation of etch after 6 hours

Evaluation time 0 hours 6 hours 12 hours 18 hours Cu content 300ppm 3000ppm 5000ppm 7000ppm Mo content 21 ppm 210 ppm 350ppm 490 ppm Ti content 9ppm 90ppm 150ppm 210 ppm Example 1 1.09 占 퐉 / 52.05 占 1.08 mu m / 53.97 DEG 1.07 mu m / 55.11 DEG 1.06 占 퐉 / 56.19 占 Comparative Example 7 1.47 占 퐉 / 52.13 占 1.44 占 퐉 / 64.70 占 1.54 [mu] m / 80.54 [ 1.56 m / 83.61

Referring to Table 5, Example 1 corresponding to the etchant composition of the present invention shows a range in which the CD bias and taper angle are required, and the change is small. This supports the fact that when the etchant composition of the present invention is applied to an LCD or OLED wet etch process, it is not often necessary to replace the etchant composition even if the etch process is repeated after a certain period of time has stagnated, And economical efficiency can be secured.

Claims (9)

Hydrogen peroxide; Phosphoric acid or phosphate compounds; Sulfate compounds: fluorine compounds; Chelating agents; And an etchant composition comprising a corrosion inhibitor,
Based on 100 parts by weight of the etchant composition,
0.05 to 0.1 part by weight of the phosphoric acid or phosphate compound is contained,
And 0.1 to 0.4 parts by weight of the sulfate compound. The method according to claim 1,
The phosphate compound is selected from the group consisting of NaH ₂ PO ₄ , Na ₂ HPO ₄ , KH ₂ PO ₄ , K ₂ HPO ₄ , NH ₄ ) H ₂ PO ₄ ) and ammonium diphosphate ((NH ₄ ) ₂ HPO ₄ ). The method according to claim 1,
The sulfate-based compound is potassium hydrogen sulfate (KHSO _4), sodium bisulfate (NaHSO _4), hydrogen sulfate ammonium _{((NH 4) HSO 4)} , potassium sulfate (K ₂ SO _4), sodium sulfate (Na ₂ SO _4), and the etching liquid composition of ammonium sulfate is at least one member selected from the group consisting of _{((NH 4) 2 SO 4} ). The method according to claim 1,
The fluorine-containing compound is hydrogen fluoride (HF), sodium fluoride (NaF), hydrogen fluoride Sodium (NaHF _2), ammonium fluoride (NH ₄ F), acidic ammonium fluoride (NH ₄ HF _2), boron trifluoride ammonium (NH ₄ BF ₄ ), potassium fluoride (KF), potassium hydrogen fluoride (KHF ₂ ) and aluminum fluoride (AlF ₃ ). The method according to claim 1,
Wherein the chelating agent is selected from the group consisting of iminodiacetic acid, diglycolic acid, thioglycolic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetri nyl pentaacetic acid, diethylenetrinitrilacetic acid, aminotris (methylenephosphonic acid), (1-hydroxyethane-1,1-diyl) bis (phosphonic acid) ((1-hydroxyethane- bis (phosphonic acid), ethylenediamine tetra (methylene phosphonic acid), diethylenetriamine penta (methylene phosphonic acid), alanine, alanine, glutamic acid at least one selected from the group consisting of glutamic acid, aminobutyric acid, and glycin. The method according to claim 1,
Wherein the corrosion inhibitor is selected from the group consisting of furane, thiophene, pyrrole, oxazole, imidazole, methylimidazole, pyrazole, triazole, ), Aminotriazole, tetrazole, 5-aminotetrazole, methyltetrazole, piperazine, methylpiperazine, hydroxylethylpiperazine, But are not limited to, hydroxyethylpiperazine, pyrrolidine, alloxan, benzofurane, benzothiophene, indole, benzimidazole, benzpyrazole, Wherein the at least one selected from the group consisting of tolutriazole, hydrotolutriazole and hydroxytolutriazole is at least one selected from the group consisting of: The method according to claim 1,
Wherein the total content of the phosphoric acid or phosphate compound and the sulfate compound is 0.2 to 0.35 parts by weight. And etching the metal film on the substrate with the etchant composition according to any one of claims 1 to 7. The method of claim 8,
Wherein the metal film is a copper film or a copper alloy film.

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