CN114438495A

CN114438495A - Metal etching solution and metal etching method

Info

Publication number: CN114438495A
Application number: CN202011209219.4A
Authority: CN
Inventors: 许靖惟
Original assignee: Xuancheng Hengwang New Material Co ltd
Current assignee: Xuancheng Hengtai Electronic Chemical Material Co ltd
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2022-05-06

Abstract

The invention provides a metal etching solution, which comprises: 5 to 30 wt% of an oxidizing agent; 2.5 to 15 wt% of an amino acid; 2.5 to 15 wt% of a phosphate; 2 to 15 wt% of a non-amino acid carboxylic acid; and the balance water. In the invention, hydrogen peroxide and persulfate are selected as oxidants, and the use weight ratio of the hydrogen peroxide to the persulfate is controlled to be 1: 1.5 to 1: 5, the metal etching solution has good etching efficiency, service life and safety.

Description

Metal etching liquid and metal etching method

Technical Field

The present invention relates to an etching solution and an etching method, and more particularly, to a metal etching solution and a metal etching method.

Background

With the increasing size of semiconductors and flat panel displays, copper metal is often used as a wiring material on a semiconductor substrate in order to reduce the resistance of the device and increase the current conduction rate thereof. However, because copper metal is not well bonded to a semiconductor substrate (e.g., a glass substrate), a molybdenum metal bonding layer is generally disposed between the copper metal layer and the substrate to enable the copper metal to be well bonded to the semiconductor substrate.

Generally, a metal multilayer film having a metal such as copper or molybdenum is mainly treated by wet etching. Wet etching is a technique of oxidizing and dissolving a target metal not shielded by a mask by an oxidizing agent in an etching solution, and forming a predetermined pattern by the undissolved metal.

In the prior art, the oxidant of the etching solution is mainly hydrogen peroxide. Although the etchant containing hydrogen peroxide has a high theoretical life, in practical applications, for example, metal ions generated after metal is oxidized and dissolved catalyze the decomposition of hydrogen peroxide, which leads to a reduction in the life. Moreover, the use of hydrogen peroxide in too high a concentration as an oxidizing agent may create a risk of combustion or explosion. In addition, in order to prolong the service life of the etching solution, hydrogen peroxide stabilizers are often added, the pH is adjusted, or the reaction temperature is controlled.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a metal etchant, including: 5 to 30 wt% of an oxidizing agent; 2.5 to 15 wt% of an amino acid; 2.5 to 15 wt% of a phosphate; 2.5 to 15 wt% of a non-amino acid carboxylic acid; and the balance water; wherein the oxidant comprises hydrogen peroxide and persulfate, and the use weight ratio of the hydrogen peroxide to the persulfate is 1: 1.5 to 1: 5.

preferably, the persulfate salt comprises: at least one selected from the group consisting of sodium persulfate, potassium persulfate, ammonium persulfate, sodium persulfate, oxone, and oxone.

Preferably, the amino acids include: at least one selected from the group consisting of iminodiacetic acid, iminodibutyric acid, nitrilotriacetic acid, carbamic acid, aminobutyric acid, ethylenediaminetetraacetic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentaacetic acid, aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, leucine, isoleucine, sarcosine, alanine, glutamic acid, lysine, methionine, phenylalanine, glutamine, glycine, cystine, serine, arginine, aspartic acid, and asparagine.

Preferably, the phosphate salt comprises: at least one selected from the group consisting of sodium phosphate, potassium phosphate, ammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate.

Preferably, the non-amino acid carboxylic acids include: at least one selected from the group consisting of 2-hydroxysuccinic acid, oxalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, dodecanoic acid, hexadecanoic acid, tetradecanoic acid, stearic acid, glycolic acid, succinic acid, diglycolic acid, adipic acid, aconitic acid, salicylic acid, malonic acid, propane-1, 2, 3-tricarboxylic acid, pyruvic acid, glutaric acid, lactic acid, itaconic acid, linoleic acid, linolenic acid, oleic acid, mandelic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, tartaric acid, maleic acid, fumaric acid, hydroxybutyric acid, and citric acid.

Preferably, the metal etching solution further includes 0.01 to 0.1 wt% of an azole compound.

Preferably, the azole compound includes: at least one selected from the group consisting of pyrazole, imidazole, oxazole, benzopyrazole, benzimidazole, 1,2, 4-triazole, 3-amino-1, 2, 4-triazole, benzotriazole, methylbenzotriazole, hydroxymethylbenzotriazole, tetrazole, 5-methyltetrazole, 5-phenyltetrazole, 5-aminotetrazole, and triphenyltetrazole chloride.

Another object of the present invention is to provide an etching method, comprising: a preparation step of providing a substrate, wherein the substrate comprises a metal layer film and a shielding film for shielding the metal layer film; etching the part of the metal layer film which is not shielded by the shielding film by using the metal etching solution; wherein the metal layer film comprises at least one selected from the group consisting of copper and molybdenum, or an alloy thereof.

Preferably, the metal layer film comprises at least a first metal layer and a second metal layer, and the first metal layer comprises copper or an alloy thereof, and the second metal layer comprises molybdenum or an alloy thereof.

Preferably, the thickness of the first metal layer is between 1000 and

the thickness of the second metal layer is between 100 and

preferably, the etching rate of the metal etching solution to the first metal layer is 70 to

The etching rate of the metal etching liquid to the second metal layer is 15 to 15

Preferably, the copper loading concentration of the metal etching solution in the etching step is 8000ppm or less.

According to the metal etching solution and the metal etching method, the persulfate and the hydrogen peroxide are simultaneously used as the oxidizing agent, and the use weight ratio of the persulfate and the hydrogen peroxide is adjusted, so that the unstable etching problem caused by the autocatalytic reaction of the hydrogen peroxide can be reduced when the metal layer is etched, the stable etching rate is realized, the copper dissolution loading amount in the etching solution can be increased to prolong the service life of the etching solution, and the use concentration of the hydrogen peroxide is reduced to improve the use safety. Further, by using an amino acid, a phosphate, and a non-amino acid carboxylic acid having a specific composition, the etched metal layer film can have a flat side etching surface, better etching uniformity, and a more uniform etching angle, and no underlying metal remains.

Drawings

Fig. 1 is a flowchart of a metal etching method according to an embodiment of the present invention.

FIG. 2 is a temperature profile of copper addition concentration of 0 to 8000ppm for a metal etchant according to an embodiment of the present invention.

FIG. 3 is a SEM cross-sectional view of a semiconductor substrate etched by a metal etchant in accordance with one embodiment of the present invention.

FIG. 4 is another SEM cross-sectional view of a semiconductor substrate after being etched by a metal etchant in accordance with an embodiment of the invention.

Description of reference numerals: s101: a preparation step; s102: and (5) etching.

Detailed Description

In the following description of the present invention, detailed descriptions of the prior art will be omitted within the scope that can be easily understood by those skilled in the art.

According to the present invention, there is provided a metal etching solution, the film etching solution comprising the following composition: 5 to 30 wt% of an oxidizing agent; 2.5 to 15 wt% of an amino acid; 2.5 to 15 wt% of a phosphate; 2.5 to 15 wt% of a non-amino acid carboxylic acid; and the balance water. The metal etching solution is not easily affected by metal copper ions, has stable etching rate, long service life and good copper dissolution loading capacity, and has the advantage of difficult combustion or explosion due to the reduction of the concentration of hydrogen peroxide.

In the present invention, the content of the oxidizer is 5 to 30 wt%, and when the content of the oxidizer is less than 5 wt%, the etching rate is too slow and the etching effect is not good; and when the content of the oxidizer is more than 30 wt%, the etching rate is too fast to cause a decrease in etching uniformity.

The oxidant of the invention comprises hydrogen peroxide and persulfate, and the weight ratio of the hydrogen peroxide to the persulfate can be between 1: 1.5 to 1: 5. when the weight ratio is lower than 1: 1.5, the etching rate of the etching solution is too slow and when a weight ratio higher than 1: 5, the etching rate of the etching solution is too high, and the hydrogen peroxide concentration is too high to easily burn or explode.

The metal loading concentration is a metal concentration at the time of dissolving a metal in an etching solution, and is an index of whether or not the etching solution needs to be replaced, and therefore, a higher metal loading concentration represents a longer service life, and more preferably, a copper loading concentration is used as a representative. The etching solution of the invention is prepared by setting the use weight ratio of hydrogen peroxide to persulfate to 1: 1.5 to 1: 5, the copper-containing etching solution still has good etching effect under the condition that the copper loading concentration in the etching solution is at least 8000ppm, and has good service life and use safety.

The persulfate of the present invention provides oxidation capability primarily through its persulfate. Preferably, the persulfate salt comprises: at least one selected from the group consisting of sodium persulfate, potassium persulfate, ammonium persulfate, sodium persulfate, oxone, and oxone.

Preferably, the amino acids of the invention include: at least one selected from the group consisting of iminodiacetic acid, iminodibutyric acid, nitrilotriacetic acid, carbamic acid, aminobutyric acid, ethylenediaminetetraacetic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentaacetic acid, aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, leucine, isoleucine, sarcosine, alanine, glutamic acid, lysine, methionine, phenylalanine, glutamine, glycine, cystine, serine, arginine, aspartic acid, and asparagine.

Preferably, the phosphate salts of the present invention comprise: at least one selected from the group consisting of sodium phosphate, potassium phosphate, ammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate.

Preferably, the non-amino acid carboxylic acids of the present invention include: at least one selected from the group consisting of 2-hydroxysuccinic acid, oxalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, dodecanoic acid, hexadecanoic acid, tetradecanoic acid, stearic acid, glycolic acid, succinic acid, diglycolic acid, adipic acid, aconitic acid, salicylic acid, malonic acid, propane-1, 2, 3-tricarboxylic acid, pyruvic acid, glutaric acid, lactic acid, itaconic acid, linoleic acid, linolenic acid, oleic acid, mandelic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, tartaric acid, maleic acid, fumaric acid, hydroxybutyric acid, and citric acid.

In the present invention, since both amino acids and non-amino acid carboxylic acids are organic acids, hydrogen ions can be supplied during etching as a reactant for oxidizing and dissolving a metal into metal ions, which is advantageous for etching a metal layer film, and the residual of an underlying metal (for example, molybdenum) can be avoided without using a chloride.

In addition, since the amino acid, the phosphate and the non-amino acid carboxylic acid of the present invention can be used as chelating agents to chelate with metal (e.g., copper) ions generated by etching and shield the metal ions to prevent the metal ions from catalyzing the decomposition of hydrogen peroxide, the three chelating agents having different structures can provide a function of sufficiently stabilizing hydrogen peroxide to extend the service life of the etching solution.

In addition, because the phosphate of the invention has multi-proton characteristics, and the amino acid simultaneously has amino group capable of combining hydrogen ions and carboxyl group capable of releasing hydrogen ions, both can be used as pH regulator (acid-base buffer), stabilize the pH value of the etching solution, facilitate the etching reaction, avoid the decomposition of hydrogen peroxide due to the drastic change of the pH value, and also stabilize the hydrogen peroxide and prolong the service life of the etching solution.

Preferably, the metal etching solution of the present invention further includes 0.01 to 0.1 wt% of an azole compound.

Preferably, the azole compound of the present invention includes: at least one selected from the group consisting of pyrazole, imidazole, oxazole, benzopyrazole, benzimidazole, 1,2, 4-triazole, 3-amino-1, 2, 4-triazole, benzotriazole, methylbenzotriazole, hydroxymethylbenzotriazole, tetrazole, 5-methyltetrazole, 5-phenyltetrazole, 5-aminotetrazole, and triphenyltetrazole chloride.

In the present invention, since the azole compound can be used as an etching inhibitor, it can reduce the undercut and prevent the formation of an etching angle (i.e., a reverse tilt angle) of 90 ° or more by adjusting the etching selectivity of different metals (e.g., copper, molybdenum), and since the etching rate is reduced, it is possible to make the undercut depth more uniform and make the etching angle more uniform and make the angle fall within a more precise range.

In addition, the complex formed by chelating the amino acid, phosphate and non-amino acid carboxylic acid with the metal ion of the present invention also functions as the etching inhibitor.

Therefore, the metal etching solution of the invention can make the metal layer film etched by the etching solution have smaller side etching, better etching uniformity and more uniform etching angle by using the amino acid, the phosphate and the non-amino acid carboxylic acid with specific compositions, and has no bottom layer metal residue and improved use safety of the etching solution.

In the following, a metal etching method according to another aspect of the present invention will be described with reference to fig. 1, but the metal etching method of the present invention is not limited to the method shown in fig. 1, and conventional means such as surface treatment, cleaning, and drying may be added before or after any step as necessary. The metal etching method of the invention comprises the following steps: a preparation step S101 of providing a substrate, wherein the substrate includes a metal layer film and a shielding film for shielding the metal layer film; and an etching step S102 of etching a portion of the metal layer film not shielded by the shielding film using the metal etching solution of the present invention.

Preferably, the metal layer film of the present invention comprises at least one selected from the group consisting of copper and molybdenum, or an alloy thereof. Preferably, the metal layer film of the present invention may be a single metal layer consisting of at least one of these metals and alloys thereof.

Preferably, the metal layer film of the present invention comprises at least a first metal layer and a second metal layer, wherein the first metal layer comprises copper or an alloy thereof, and the second metal layer comprises molybdenum or an alloy thereof. Preferably, when the metal layer film of the present invention includes the first metal layer and the second metal layer, the first metal layer covers an upper surface of the second metal layer, and the shielding film covers an upper surface of the first metal layer.

Preferably, the substrate of the present invention may be a glass substrate.

Preferably, the thickness of the first metal layer of the present invention is between 1000 a and

and the thickness of the second metal layer is between 100 and

preferably, the etching rate of the metal etching solution of the present invention to the first metal layer is 70 to 70

And the etching rate of the second metal layer is 15 to 15

Preferably, when the copper loading concentration in the metal etching solution in the present invention is 8000ppm or less, the metal etching solution can maintain a good etching effect.

Preferably, the etching is performed at a temperature of 25 to 38 ℃ using the etching solution of the present invention, and the etching angle of the metal layer film has good uniformity.

In order to verify the efficacy of the metal etching solution and the metal etching method of the present invention, the etching performance, the service life and the safety of the present invention are illustrated by way of examples below.

[ example 1]

Firstly, deionized water contains 10 wt% of ammonium persulfate, 5 wt% of hydrogen peroxide, 6.5 wt% of glycine, 10 wt% of ammonium phosphate and 5 wt% of glacial acetic acid, and the deionized water and the glycine, the ammonium phosphate and the glacial acetic acid are stirred and uniformly mixed to prepare the metal etching solution.

Preparing a glass substrate having a thickness of

Of a thickness of

The copper metal layer and the shielding film are formed to obtain a semiconductor substrate. The semiconductor substrate was left to stand in the prepared metal etching solution at a temperature of 32 c, and the etching state of the copper metal layer and the molybdenum metal layer, which were not shielded by the shield film, was visually observed (watch and stop), and the etching time was recorded. When the color of copper metal (red orange) and the color of molybdenum metal (gray black) completely disappeared, indicating that the copper metal layer and the molybdenum metal layer, which were not shielded, were completely etched, respectively, the respective etching times of the metal layers were recorded, and the etching rates were calculated from the thickness of the metal layer and the etching time, and the test results are described in table 1 below.

Then, another new semiconductor substrate and a new etching solution are used to perform etching with a total etching time of 130%. In example 1, the total etching time required was (27+10) × 130% — about 50 seconds.

After the etching of 130% was completed and the cleaning was dried, the undercut depth and the etching angle of the copper/molybdenum metal layer not masked by the masking film were observed at the left side (L) and the right side (R) after the etching using a scanning electron microscope (SEM, Hitachi), 6 points were selected for each of the undercut depth and the etching angle, and the coefficient of variation values (C.V.) of the undercut depth and the etching angle of the repeated tests were calculated, and the experimental conditions and the results are shown in table 2 below.

[ example 2]

In example 2, a metal etching solution, a semiconductor substrate and a metal layer film were prepared and etched in the same manner as in example 1, except that the thicknesses of the copper/molybdenum metal layers of the semiconductor substrate were changed to be the same as those of the copper/molybdenum metal layers, respectively

And (c) out. Specific experimental conditions and test results are shown in tables 1 and 2 below.

[ Table 1]

[ Table 2]

According to the results in Table 1, the etchant of the present invention has a thickness of 2000 to

The etching rate of the copper metal layer is between 70 and

for thickness between 200 and

the etching rate of the molybdenum metal layer is between 15 and

it can be confirmed that the present invention has a good etching rate.

According to the results in Table 2, the etching solution of the present invention has a single side etching rate of less than 500nm for the copper/molybdenum metal layer films with different thicknesses, which is less than the single side etching rate of less than 1 μm in the prior art; and the etching angle is between 45 ° and 55 °, limiting the etching angle to a more precise range than the etching angle of the prior art between 20 ° and 60 °. And, according to the above repeated test results, the coefficient of variation of both undercut and etch angle was less than 5%, there was no significant difference, and there was good undercut uniformity and etch angle uniformity.

[ example 3]

In example 3, except that the thicknesses of the copper/molybdenum metal layers of the semiconductor substrate were changed to be different

Except that a metal etching solution, a semiconductor substrate and a metal layer film were prepared and etched in the same manner as in example 1, but the temperature of the etching solution was not controlled, and the temperature of the etching solution after etching was recorded. Also, the undercut depth and the etching angle were tested in the same manner as in example 1, except that only 1 point was selected for the test, respectively. The copper addition concentration in the etching solution and the test results are shown in table 3 below.

[ examples 4 to 7]

In examples 4 to 7, except that the thicknesses of the copper/molybdenum metal layers of the semiconductor substrates were changed respectively

Except that, a semiconductor substrate and an etched metal layer film were prepared in the same manner as in example 1, except that the temperature of the etching solution was not controlled, and the etching solutions of examples 3 to 6 were used after 2 hours from the start of etching, and 2000ppm of copper powder was added to the etching solutions, respectively, and then etching was performed. Also, the temperature, undercut depth, and etching angle were tested in the same manner as in example 3. The cumulative etch time and cumulative copper addition concentration from the beginning of example 3 and the test results are shown in table 3 below.

Further, in example 7, the copper addition concentration in the etching solution after the end of etching (cumulative time 8 hours) reached 8000ppm, and thereafter the temperature change of the etching solution was continuously observed until the cumulative time reached 48 hours.

In addition, coefficient of variation values of undercut depth and etching angle in the copper addition concentration range (copper cumulative addition concentration range) of 0 to 8000ppm in examples 3 to 7 were further calculated. The calculation results are shown in table 3 below.

[ Table 3]

According to the results in Table 3, the coefficient of variation of the undercut was less than 10% for the same etching time of the metal layer film in the copper additive concentration range of 0 to 8000ppm, and there was no significant difference, indicating that the etching rate was not changed with the increase of the copper additive concentration in the copper additive concentration range of 8000ppm, the etching solution of the present invention was not affected by the metal ion catalysis, and had a stable etching rate and good etching stability.

Also, according to the results in Table 3, the metal layer film was etched for the same time period within the range of 0 to 8000ppm of the copper addition concentration, and the variation coefficient of the etching angle was less than 5%, and there was no significant difference, which indicates that the effect of controlling the etching angle was not changed within the range of 8000ppm of the copper addition concentration, and it was also confirmed that the metal layer film had good etching stability. As shown in Table 3 and FIG. 2, the temperature of the etching solution of the present invention was within the range of 23. + -. 0.5 ℃ even when the copper addition concentration was as high as 8000ppm (i.e., the copper loading concentration was at least 8000 ppm). Further, the temperature of the etching solution was also within a range of 23. + -. 0.5 ℃ as continuously observed for 48 hours. From the above results, it is understood that the etchant of the present invention has a stable reaction rate and good temperature stability even when it contains a high concentration of metal (e.g., copper loading concentration of 8000ppm or less), thereby avoiding the problem of lowering the service life and etching stability of the etchant due to accelerated decomposition of hydrogen peroxide caused by temperature rise, and has good safety in use without explosion or combustion of hydrogen peroxide caused by temperature rise.

In addition, according to the results of examples 3 to 7, although the etching time was accumulated up to 8 hours, the undercut depth was not significantly changed, showing that the overall etching rate was not deteriorated, and the etching solution had high stability during the etching process.

In addition, according to the results of Table 3, the etching solution of the present invention has a single side etching of less than 450nm and less than the single side etching of less than 1 μm of the prior art for the copper/molybdenum metal layer film even when the copper addition concentration is as high as 8000ppm (i.e., the copper loading concentration is at least as high as 8000 ppm); also, the etching angle is between 40 ° and 50 °, which limits the etching angle to a more precise range than the etching angle between 20 ° and 60 ° in the prior art.

As shown in fig. 3 and 4, the structure of example 2 after the over-etching of 130% was observed using a scanning electron microscope (SEM, Hitachi), the glass substrate had no molybdenum metal remained, and the copper/molybdenum metal layer exhibited an etching angle of about 45 °.

In summary, according to the metal etching solution and the metal etching method of the present invention, the persulfate and the hydrogen peroxide are used as the oxidizing agent at the same time, and the use weight ratio of the persulfate and the hydrogen peroxide is adjusted, so that the unstable etching problem caused by the autocatalytic reaction of the hydrogen peroxide can be reduced and the safety problem caused by the high concentration of the hydrogen peroxide can be reduced when the metal layer is etched, thereby having a good etching rate, and the copper dissolution loading amount in the etching solution can be increased to prolong the service life of the etching solution.

In addition, the metal etching solution and the metal etching method of the present invention can provide a metal layer film etched by using amino acids, phosphates and non-amino acid carboxylic acids having specific compositions, which has a flat side etching surface, better etching uniformity, more uniform etching angle, and no bottom layer molybdenum metal residue.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. A metal etchant, comprising: 5 to 30 wt% of an oxidizing agent; 2.5 to 15 wt% of an amino acid; 2.5 to 15 wt% of a phosphate; 2.5 to 15 wt% of a non-amino acid carboxylic acid; and the balance of water, wherein,

wherein the oxidant comprises hydrogen peroxide and persulfate, and the use weight ratio of the hydrogen peroxide to the persulfate is 1: 1.5 to 1: 5.

2. the metal etchant according to claim 1, wherein the persulfate includes: at least one selected from the group consisting of sodium persulfate, potassium persulfate, ammonium persulfate, sodium persulfate, oxone, and oxone.

3. The metal etchant of claim 1, wherein the amino acid comprises: at least one selected from the group consisting of iminodiacetic acid, iminodibutyric acid, nitrilotriacetic acid, carbamic acid, aminobutyric acid, ethylenediaminetetraacetic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentaacetic acid, aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, leucine, isoleucine, sarcosine, alanine, glutamic acid, lysine, methionine, phenylalanine, glutamine, glycine, cystine, serine, arginine, aspartic acid, and asparagine.

4. The metal etchant of claim 1, wherein the phosphate comprises: at least one selected from the group consisting of sodium phosphate, potassium phosphate, ammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate.

5. The metal etchant according to claim 1, wherein the non-amino acid carboxylic acid comprises: at least one selected from the group consisting of 2-hydroxysuccinic acid, oxalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, dodecanoic acid, hexadecanoic acid, tetradecanoic acid, stearic acid, glycolic acid, succinic acid, diglycolic acid, adipic acid, aconitic acid, salicylic acid, malonic acid, propane-1, 2, 3-tricarboxylic acid, pyruvic acid, glutaric acid, lactic acid, itaconic acid, linoleic acid, linolenic acid, oleic acid, mandelic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, tartaric acid, maleic acid, fumaric acid, hydroxybutyric acid, and citric acid.

6. The metal etchant according to claim 1, further comprising: 0.01 to 0.1 wt% of an azole compound comprising: at least one selected from the group consisting of pyrazole, imidazole, oxazole, benzopyrazole, benzimidazole, 1,2, 4-triazole, 3-amino-1, 2, 4-triazole, benzotriazole, methylbenzotriazole, hydroxymethylbenzotriazole, tetrazole, 5-methyltetrazole, 5-phenyltetrazole, 5-aminotetrazole, and triphenyltetrazole chloride.

7. A metal etching method, comprising:

a preparation step of providing a substrate, wherein the substrate comprises a metal layer film and a shielding film for shielding the metal layer film; and

an etching step of etching a portion of the metal layer film not shielded by the shielding film using the metal etching liquid according to any one of claims 1 to 6,

wherein the metal layer film comprises at least one selected from the group consisting of copper and molybdenum, or an alloy thereof.

8. The method of claim 7, wherein the metal layer film comprises at least a first metal layer and a second metal layer, and the first metal layer comprises copper or an alloy thereof, and the second metal layer comprises molybdenum or an alloy thereof.

9. The metal etching method according to claim 8, wherein an etching rate of the first metal layer by the metal etching liquid is 70 to 70

And the etching rate of the second metal layer is 15 to 15

10. The metal etching method according to claim 7, wherein a copper-carrying concentration of the metal etching liquid in the etching step is 8000ppm or less.