KR101763170B1 - Etching Composition - Google Patents

Abstract

The present invention relates to an etching composition, in particular to an etching composition for the production of semiconductors, which comprises a first inorganic acid; And urea, wherein the N _hydrogen ≤ N _{amine group} (N _hydrogen is the total number of moles of the first inorganic acid contained in the etching composition and the N _{amine group} is the total number of moles of amine groups provided by urea) .

Description

Etching composition {

The present invention relates to an etching composition, and more particularly, to an etching composition which prevents volatilization of an acid, is excellent in work safety, and has a remarkably high etch selectivity.

Various kinds of films showing different etching characteristics are present together on a semiconductor substrate in accordance with the development direction of electronic devices and display devices such as lightening and high integration, and wirings have more three-dimensional shapes and are formed in multiple layers.

Therefore, a technique capable of more efficient etching in a narrower space is required. When various films such as an oxide film, a nitride film, a polysilicon film, and a metal film existing on a substrate are treated by wet etching, each etching target film is removed with a high etch selectivity ratio Not only are the etchants that can be important, but it will be an important factor in the technological competition to contend with the degree of integration of semiconductors in the future.

For example, in order to effectively strip nitride films in wet etching of 3D NAND, a high selectivity etchant with a high selectivity ratio between oxide and nitride is required. An industrially desirable etchant of a high selectivity has a selectivity of about 200, which means that when the nitride is etched, the selectivity of 200 means that the oxide is only etched by 1 Å when the nitride is etched to 200 Å.

Generally, etchanturophosphoric acid is mainly used for this nitride etch, nitric acid and hydrogen fluoride are used for etchant etching, and etchronurophosphoric acid, acetic acid and nitric acid are used for wiring etching such as aluminum.

In accordance with the demand of the etch composition having a higher selectivity ratio continuously for high integration and lightening, it is preferable to add an organic acid or a weak acid such as an organic acid or a weak acid, However, the selection ratio is only around 50, which is far less than the industrial selection ratio.

Furthermore, since the etchant that imparts the etching ability to the etching composition is a strong acid which is highly volatile, it poses a risk to the human body and poses a threat to the safety of the operator. Moreover, safety in handling and use is inferior, There is a problem that the construction cost is increased and the productivity is lowered.

Korea Patent Publication No. 2005-0054015 U.S. Published Patent Application No. 2004-0077168

It is an object of the present invention to provide an etching composition having an extremely good etch selectivity.

Another object of the present invention is to provide an etching composition and a cleaning composition which are capable of preventing the volatilization of strong acids, having excellent work safety, and being easy to handle.

An etching composition according to an embodiment of the present invention comprises a first inorganic acid; And urea, and may satisfy the following relational expression (1).

(Relational expression 1)

N _hydrogen < = N _{amine group}

In relation 1, N _hydrogen is the total molar number of moles of the first inorganic acid contained in the etching composition, and N _{amine group} is the total number of moles of amine groups provided by urea.

In the etching composition according to an embodiment of the present invention, the first inorganic acid may have a pKa of -10 to 7.

In an etching composition according to an embodiment of the present invention, the first inorganic acid may be selected from the group consisting of mono-acid of sulfuric acid, nitric acid, boric acid, hydrogen fluoride, phosphoric acid or hydrochloric acid; Or a mixture of two or more selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid and hydrogen fluoride.

The etching composition according to an embodiment of the present invention may further contain a second acid which is an organic acid, a different inorganic acid from the first inorganic acid, or a mixed acid thereof.

The etching composition according to an embodiment of the present invention can satisfy Relation 1-1.

(Relational expression 1-1)

N _Hydrogen ≤ N _{Amine group} ≤ 4 N _Hydrogen

In the relational expression 1-1, N _hydrogen and N _{amine groups} are the same as defined in relation 1.

The etching composition according to an embodiment of the present invention may further comprise water.

The etching composition according to an embodiment of the present invention can satisfy the following relational expression (2).

(Relational expression 2)

P _acid (es-ref) < 0.1 * P _acid (ac-ref)

In equation 2, P _acid (es-ref) is the 25 ° C partial pressure of the first inorganic acid in the reference etch composition comprising the same amount of first inorganic acid, urea and solvent as the etch composition, and P _acid (ac- Of the first inorganic acid in the reference inorganic acid composition composed of the first inorganic acid and the solvent.

The etch composition according to an embodiment of the present invention may be for nitride etch, containing phosphoric acid, urea, and water, and may contain urea at 1 mole or more per mole of phosphoric acid.

The etching composition according to an embodiment of the present invention may further include an additive.

The etching composition according to an embodiment of the present invention may be for metal etching or inorganic etching.

The present invention includes an etching method using the etching composition described above.

The present invention relates to an inorganic acid; Urea; And a cleaning liquid for semiconductor processing which contains water and satisfies the following relational expression (1 ').

(Relational expression 1 ')

N _hydrogen &lt; = N _{amine group}

In the relational formula 1, N _hydrogen is the total moles of hydrogen of the first inorganic acid contained in the cleaning liquid, and N _{amine group} is the total number of moles of amine groups provided by urea.

The etching composition according to an embodiment of the present invention is characterized in that the polar acid of the inorganic acid and the urea exists in a state in which the inorganic acid is suppressed and / or buffered, and the polarity with the urea is in a dynamic equilibrium state It is advantageous to have an extremely high etch selectivity because the difference between the target material in which the inorganic acid is well etched and the base material in which the etch is hard to occur is further amplified, The volatility of the inorganic acid is remarkably reduced and the toxicity of the inorganic acid is not shown so that the human body is safe and the fumes of the inorganic acids are not generated and the working environment is greatly improved and the corrosive phenomenon of the equipment is remarkably decreased and the workability and safety are greatly improved .

FIG. 1 is a graph showing the etching performance of a copper film of an etching composition according to an embodiment of the present invention,
2 is a graph showing etching performance of a silicon oxide film of an etching composition according to an embodiment of the present invention,
FIG. 3 is a photograph showing the human safety of the etching composition according to an embodiment of the present invention,
4 is another graph showing the etching performance of the etching composition for a silicon oxide film according to an embodiment of the present invention,
FIG. 5 is a graph showing etch selectivity for a silicon nitride film of an etching composition according to an embodiment of the present invention,
FIG. 6 is a graph showing the etching performance of the etching composition for silicon according to an embodiment of the present invention,
7 is a graph showing silicon etch selectivity of the etching composition according to an embodiment of the present invention,
8 is a graph showing the silicon nitride etch performance of the etch composition according to an embodiment of the present invention,
9 is a graph showing the silicon oxide etching performance of the etching composition according to an embodiment of the present invention.

Hereinafter, the etching composition of the present invention will be described in detail. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

Applicants have conducted extensive research on etch compositions having a high etch selectivity over a long period of time and found that when the urea, which is very weak and nontoxic, is used as a base pair of an inorganic acid used as an etchant, It is found that the etch selectivity ratio is remarkably improved without being damaged, and that the enhancement of the etch selectivity by the urea is expressed by the content of urea relative to the inorganic acid regardless of the kind of the inorganic acid, It has been found that volatilization of inorganic acid is remarkably prevented when urea in an amount of not less than the above amount is added, and thus the present invention has been filed.

An etching composition according to an embodiment of the present invention comprises a first inorganic acid; And urea, and can satisfy the following relational expression (1).

(Relational expression 1)

N _hydrogen &lt; = N _{amine group}

In relation 1, N _hydrogen is the total moles of hydrogen of the first inorganic acid contained in the etching composition, and N _{amine group} is the total number of moles of amine groups provided by urea. That is, N _hydrogen is the total number of moles of hydrogen of the first inorganic acid contained in the etching composition, and N _{amine group} is the total amine group moles of urea contained in the etching composition.

Relation 1 is a condition in which in the etching composition, the hydrogen of the first inorganic acid may be present in a state of weakly polar bonding with the amine group of urea. Due to the weak basicity of urea, loose polar bonds between the first inorganic acid and urea are maintained in the static state, which is not in contact with the material to be etched, but when the material is in contact with the material to be etched, the polar bonding between the first inorganic acid and the urea is in a dynamic equilibrium state The first inorganic acid itself is released and the etching ability of the first inorganic acid itself is manifested. At this time, since the difference in etching between the target material in which the first inorganic acid is well etched and the substrate material in which the etching is not good is amplified, It is possible to have an improved etching selectivity ratio.

In detail, when a polar bond between the first inorganic acid and urea is brought into contact with an object to be etched, the bond can be instantaneously broken by the dynamic equilibrium so that the etching ability by the first inorganic acid can be expressed, The polar bonding between the first inorganic acid and the urea is broken at the surface of the material to be etched and the free inorganic acid is instantly formed to cause the etching. In the etching target material, the etching ability of the first inorganic acid itself is expressed as it is, The poor substrate material is present in the etching composition and exhibits an inhibitory effect by chemical equilibrium urea. Consequently, this etching composition of the present invention can exhibit a high etch selectivity for the etch target material and the substrate material. That is, the first inorganic acid is etched at the surface of the material to be etched while being in a dynamic equilibrium state in which polar bonds with urea are momentarily broken and recombined with urea. Therefore, in the case of a substance which is easily etched by the first inorganic acid, it is hardly influenced by the dynamic equilibrium of recombination with urea, and is almost the same as or similar to the first inorganic acid itself (etchant containing no urea and containing the first inorganic acid) A material which is etched but is not well etched with the first inorganic acid remarkably decreases in contact with the free first inorganic acid and can be interpreted as having a high etch selectivity.

In describing the present invention, the first inorganic acid may mean an etchant that performs an action of etching an object to be etched by reacting with the object to be etched. Specifically, the first inorganic acid may mean an acid which reacts directly with an object to be etched, which produces a reaction product different from that of the object to be etched. That is, after the etching removal of the substance to be etched actually is changed to the one reaction product A1 by the substance to be etched and the inorganic acid (A), the one reaction product A1 is changed to another one by the other one inorganic acid (B) In the case where the reaction is carried out by a reaction of two or more steps which changes into the reaction product (B1), the first inorganic acid may mean an inorganic acid (A) which reacts directly with the substance to be etched to produce a reaction product. Depending on the type of object to be etched, the first inorganic acid may be a mono-acid or a mixed acid composed of two or more acids. When the first inorganic acid is a mixed acid, the N _hydrogen may be the number of moles of all the moles of hydrogen forming each of the first inorganic acids.

The etchant composition according to an embodiment of the present invention is a dynamic equilibrium state in which the etchant is broken due to the breakage of the polar bond between the etchant and the urea and the etchability is manifested and the etchant and the urea are recombined under the etching condition, As the etching target material is etched, selective etching of the etching target material is performed, and etching of other unwanted materials (non-etching target material or base material) can be prevented.

Specifically, when containing urea of less than 1, the etchant composition will have free first inorganic acid that does not polar bond with urea. This free primary inorganic acid exhibits the etch selectivity of the material itself under the etch conditions, which can lower the etch selectivity of the etch composition. Specifically, when the concentration of the free first inorganic acid that does not polarize with the urea in the etching composition is M, the etch composition has the etch selectivity characteristic of the composition containing the first inorganic acid with no concentration of urea, It is inevitably required to have a remarkably low etch selectivity with respect to the etching composition satisfying the relational expression (1).

The etch composition according to an embodiment of the present invention comprises a first inorganic acid which is an etchant of urea and a substance to be etched, and satisfies Relation 1, thereby achieving an extremely high etch selectivity ratio of 150 or more, particularly an etchant composition for semiconductor oxide or semiconductor nitride Lt; RTI ID = 0.0 &gt; 200, &lt; / RTI &gt; High etch selectivity ratios over 200 are not reported to date.

The etching composition according to one embodiment of the present invention satisfies the relationship (1), wherein the ratio of the total number of moles of amine groups by urea (N _{amine group} / N _hydrogen ) to the total number of moles of hydrogen by the first inorganic acid contained in the etching composition , The etch rate and / or selectivity of the etch target material can be controlled. More specifically, but the polarity coupling of a urea and in contact with the etching substance momentarily forming a broken first inorganic acid, N _amine / N As the _hydrogen is increased, the first mineral acid the more the content of the urea increases the etching action is faster than Urea, whereby the absolute amount of the first inorganic acid in which the polar bonds are broken and / or the time during which the first inorganic acid is maintained in a state where the polar bonds are broken can be reduced. Accordingly, by controlling the N- _{amine group} / N- _hydrogen contained in the etching composition, the etching rate of the material to be etched can be precisely controlled and / or the etch selectivity can be further improved. That is, it is possible to increase the N- _{amine group} / N- _hydrogen to reduce the etching rate of the material to be etched and / or to improve the etch selectivity to the material to be etched.

As noted above, Equation 1 may mean that the etching composition according to an embodiment of the present invention contains more than the amount of urea needed to inhibit and / or buffer all of the first inorganic acid. At this time, the inhibition both the first inorganic acid and / or be present in excess of the amount needed to buffer, as well as the adverse effects caused by such an excess of the urea be missing, N _amine / N etch selectivity by the _hydrogen ratio and / or etching As the rate can be controlled, the upper limit of the urea contained in the etch composition is only a value that can be defined by the manufacturing cost and the realistic manufacturability, such as solubility in solvents or diluents (e. G., Water) The right of the stock solution according to an embodiment of the present invention can not be construed to be limited. However, in view of presenting the specific composition range of the etching composition, the etching composition may satisfy the following relational expression 1-1.

(Relational expression 1-1)

N _Hydrogen ≤ N _{Amine group} ≤ 4 N _Hydrogen

In the relational expression 1-1, N _hydrogen and N _{amine groups} are the same as defined in relation 1.

As described above, as the etch selectivity ratio is enhanced by the dynamic equilibrium in the etching condition, the increase of the etch selectivity by the urea can be achieved when the above-described relation 1 is satisfied regardless of the kind of the inorganic acid have.

In the etching composition according to an embodiment of the present invention, the first inorganic acid may be any inorganic acid known as an etchant, which reacts with the substance to be etched according to the substance to be etched to produce a reaction product different from the substance to be etched or etched Do.

As a specific example, the first inorganic acid may have a pKa of -10 to 7.

As a specific example, the first inorganic acid may be selected from the group consisting of sulfuric acid, nitric acid, boric acid, hydrogen fluoride, phosphoric acid, or hydrochloric acid; Or a mixture of two or more selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid and hydrogen fluoride. More specific examples include monoacids of sulfuric acid, nitric acid, boric acid, phosphoric acid or hydrochloric acid; Or a mixture of two or more selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid and hydrogen fluoride.

More specifically, when the substance to be etched is an oxide, the first inorganic acid may be a mono-acid of hydrogen fluoride or a mixture of hydrogen fluoride and nitric acid. Here, the oxide may include a semiconductor oxide, and may include, by way of non-limiting example, silicon oxide.

More specifically, when the substance to be etched is a nitride, the first inorganic acid may be mono-acid of phosphoric acid or a mixture of phosphoric acid and hydrochloric acid. At this time, the nitride may include a semiconductor nitride, and may include, for example, silicon nitride.

More specifically, when the substance to be etched is a semiconductor, the first inorganic acid may be monoacidic acid of nitric acid or a mixture of nitric acid and hydrogen fluoride. At this time, the semiconductor may include crystalline or amorphous silicon.

More specifically, when the substance to be etched is a metal (including an alloy), the first inorganic acid may be a mono-acid of phosphoric acid or a mixture of phosphoric acid, acetic acid and nitric acid. At this time, the metal may include a metal such as aluminum, copper, or an alloy for wiring such as an aluminum neodymium alloy and a molybdenum tungsten alloy.

However, it is apparent to those skilled in the art that the present invention can not be limited to the specific example of the present invention and the first inorganic acid to be etched. This is because the polar bonds between the first inorganic acid and the urea are broken by the contact with the substance to be etched and the first inorganic acid continuously released in the buffer solution state is released by the movement of the chemical equilibrium, It is an object of the present invention to provide a method of etching an object to be etched by a first inorganic acid in a state in which recombination is dynamically performed and thereby remarkably improving an etching selectivity ratio, The etching composition according to one embodiment of the present invention can be applied to various known etchant compositions using inorganic acid as an etchant regardless of the kind of the substance to be etched because the undesired side reaction between the additive to be added does not occur. It is possible to improve the etch selectivity of the etching composition to be.

That is, according to the teachings of the present invention, those skilled in the art of semiconductor manufacturing will recognize that etchants (inorganic acids involved in the etch reaction) of various known etch compositions can, according to one embodiment of the present invention, It can be seen that the selection ratio of the etching composition can be remarkably improved by replacing it with a mixture of the first inorganic acid and urea.

The etching composition according to an embodiment of the present invention may further comprise a solvent capable of dissolving urea or urea and a first inorganic acid which may also act as a diluent for controlling the concentration of the first inorganic acid have. The solvent of the etching composition may be used as a solvent or a diluent in a conventional etching field and may be a material capable of dissolving urea. As a specific example, the solvent may include water, a lower alcohol (C1-C3 alcohol such as methanol or ethanol), or a mixture thereof. However, the solvent is not limited thereto and may be selected from the group consisting of the manufacturing cost of the etching composition, In an industrial aspect, the solvent may comprise water.

The etching composition according to an embodiment of the present invention may contain 0.01 to 20 M (molar concentration) of a first inorganic acid (in the case of mixed acid, a concentration of all the molar concentrations of the acids forming the mixed acid) More preferably from 5M to 20M of inorganic acid, more specifically from 10M to 20M of inorganic acid. However, as described above, the concentration of the first inorganic acid can be appropriately controlled according to the material to be etched and the process conditions required in the etching process. In addition, It is of course possible to remarkably improve the selection ratio of the etching composition by further containing urea so as to satisfy the relational expression 1 in consideration of the substance and the molar concentration of the etchant.

The etching composition according to an embodiment of the present invention may further include a second acid, and the second acid may be an organic acid, an inorganic acid different from the first inorganic acid, or a mixed acid thereof.

Specifically, the second acid is an acid involved in the dissolution removal of the substance to be etched, or may be an acid which increases the etching selectivity ratio, increases the etching efficiency, decreases the roughness of the etched surface, controls the etching rate, etch isotropy or directionality Or the like), and to prevent side reactions that degrade etching ability in the etching process.

More specifically, the first inorganic acid reacts with the substance to be etched to change the substance to be etched into the first reaction product, and when the first reaction product is dissolved and removed by reacting with the other monoacid, If the elimination is caused by a sequential reaction with two or more different acids, the first inorganic acid may be an inorganic acid that reacts directly with the material to be etched to produce a first reaction product, and the other monoacid may be a second acid have. This is because the reaction with the first inorganic acid is a preliminary reaction that determines the etching removal rate and the rate of the etching removal reaction. In a non-limiting example, when the material to be etched is silicon, nitric acid or the like which directly reacts with silicon to oxidize silicon may be the first inorganic acid, and hydrogen fluoride, which dissolves and removes oxidized silicon (silica) . &Lt; / RTI &gt; In the case of aluminum, an acid such as nitric acid which oxidizes aluminum may be classified as a first inorganic acid, and phosphoric acid which dissolves and removes oxidized aluminum (alumina) may be classified as a second acid.

As described above, the second acid is effective not only in the acid involved in the etching reaction, but also in the etching selectivity ratio, the roughness control of the etching surface, the etching rate control, the etching isotropy May include an acid, specifically, an inorganic acid and / or an organic acid, which is used for orientation (directionality such as allowing a specific crystal face to be exposed in the case of crystal), prevention of side reactions that degrade the etching ability in the etching process, and the like. The inorganic acid is an inorganic acid different from the first inorganic acid, and may be one or more selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid, and hydrogen fluoride. The organic acid may comprise any organic acid known to be used in conventional etching compositions. Specific and non-limiting examples include organic acids such as acetic acid, citric acid, formic acid, oxalic acid, succinic acid, glycolic acid, lactic acid, acid, malonic acid, and malic acid may be selected. As a non-limiting example of a secondary acid that is not directly involved in the etching reaction, when ITO (indium-tin-oxide) is the substance to be etched, the first inorganic acid reacts with the indium oxide to dissolve and remove the indium oxide. And the inorganic acid classified as the second acid may be nitric acid which penetrates the interface between ITO and PR (photoresist). When aluminum is the substance to be etched, as described above, nitric acid can be classified as the first inorganic acid, phosphoric acid can be classified as the second acid involved in the etching removal reaction of the substance to be etched, May be classified as a second acid which does not participate in the etching removal reaction of the substance to be etched. Also, in the case of semiconductor crystalline or amorphous silicon, nitric acid oxidizes a substance to be etched with a first inorganic acid, and hydrogen fluoride involved in the removal of the oxide can be classified as a second acid. However, it goes without saying that the present invention can not be limited by the kind of the second acid. It goes without saying that it is possible to contain an appropriate content for each kind of the second acid through a simple repetitive experiment taking into consideration the substance to be etched and the required etching conditions. However, for a more specific understanding, given a non-limiting example, the molar ratio of first inorganic acid: secondary acid may be 1: 0 to 4, specifically 1: 0.1 to 4, and more specifically, In the case of the second acid involved in the etching reaction of the material, the molar ratio of the first inorganic acid: the second acid may be 1: 0.1 to 2, and in the case of the second acid not participating in the etching reaction of the substance to be etched, : The molar ratio of the second acid may be 1: 0.1 to 4.

Alternatively, the etching composition according to an embodiment of the present invention may contain urea so as to satisfy the relational expression 1 and satisfy the relational expression 1-2 with respect to the inorganic acid contained in the second acid.

(Relational expression 1-2)

N (2) _hydrogen ≤ N _{amine group} ≤ 4 N (2) _hydrogen

In the relational expression 1-2, N (2) _hydrogen is the total number of moles of hydrogen by the inorganic acid contained in the second acid, and N _{amine group} is the total number of moles of amine groups provided by urea. That is, N _hydrogen is the total number of moles of the inorganic acid in the second acid contained in the etching composition, and the N _{amine group} is the total amine group moles of the urea contained in the etching composition.

In order to control the etching rate more precisely, urea may be contained so as to satisfy the relational expression 1-2. Alternatively, in the case where the inorganic acid contained in the second acid is a highly toxic substance such as hydrogen fluoride, -2, it is possible to prevent the toxicity of the inorganic acid contained in the second acid from being expressed. In the case of containing hydrogen fluoride as an example, in the case of containing urea so as to satisfy the relational expression (1-2), hydrogen fluoride is combined with urea to form urea hydrofluoride and / or urea bifluoride It is present in the form of the same urea fluoride compound, so that the toxicity of hydrogen fluoride is not expressed and the volatilization can be prevented. When the urea fluoride compound is in contact with a reaction product (for example, an oxide) produced by the first inorganic acid, the bond with urea is momentarily broken and the ability to etch hydrogen fluoride itself can be exhibited.

The etching composition according to an embodiment of the present invention may further include an etching additive. In detail, the etching composition may further comprise, together with the first inorganic acid or the first inorganic acid and the second acid, an etchant commonly used in an etchant used for etching the material to be etched.

In the etching composition according to an embodiment of the present invention, the polar bonding between the first inorganic acid and the urea momentarily breaks upon contact with the substance to be etched, and the etching ability of the first inorganic acid as an etchant is expressed. Since the side reaction does not occur, the etchant (first inorganic acid) of the etchant conventionally used for etching the substance to be etched is replaced with a composition of the etchant (first inorganic acid) and urea so as to satisfy the relational expression 1 Can have significantly improved etch selectivity. It will thus be appreciated that any additive known to be commonly used in etchants conventionally used for etching the etch target material can also be used in the etchant composition according to one embodiment of the present invention, It is needless to say that it is possible to add an appropriate content for each additive type through a simple repetitive experiment taking into consideration etching conditions.

As a specific, non-limiting example, the etching composition according to an embodiment of the present invention may further contain additives commonly used in the art to improve the etching performance, wherein the additives include oxidizing agents, surfactants (wetting agents) Metal salts, antifoaming agents, corrosion inhibitors, organic solvents and the like. As a specific, non-limiting example, the surfactant can be a cationic surfactant, an anionic surfactant, or a nonionic surfactant. Examples of the cationic surfactant include amines such as C ₈ H ₁₇ NH _2. Examples of the anionic surfactant include hydrocarbon-based carboxylic acids such as C ₈ H ₁₇ COOH, hydrocarbon-based ones such as C ₈ H ₁₇ SO ₃ H Sulfonic acid, and fluorocarboxylic acids such as H (CF ₂ ) ₆ COOH. Nonionic surfactants include ethers such as polyoxyalkylene alkyl ethers. Specific and non-limiting examples of the oxidizing agent include ozone, hydrogen peroxide, ammonium hydroxide, ammonium peroxosulfate, and the like. Specific examples of the antifoaming agent (which may also serve as a corrosion inhibitor) include silicone oils, water-soluble organic solvents such as alcohol compounds and ether compounds, and water-soluble organic solvents include methyl alcohol, ethyl alcohol, Butanol, ethylene glycol, propylene glycol, glycerol, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol, 2-methyl-2,4-pentanediol, 1 , 3-butanediol, and 1,4-butanediol; Propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol, poly (ethylene glycol), propylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol, dipropylene glycol, Ether solvents such as propylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether and alkylene glycol alkyl ether including diethylene glycol monobutyl ether; Amide solvents such as formamide, monomethylformamide, dimethylformamide, acetamide, monomethylacetamide, dimethylacetamide, monoethylacetamide, diethylacetamide and N-methylpyrrolidone; Sulfone-containing solvents such as dimethylsulfone, dimethylsulfoxide and sulfolane; And lactone-based solvents such as? -Butyrolactone and? -Valerolactone. Specific and non-limiting examples of the corrosion inhibitor include iminodiacetic acid, citric acid, galic acid, and acetic acid, which are used as additives to prevent metal corrosion. And triazole-based compounds including benzotriazole and the like. Examples of organic solvents having compatibility with water and improving etching selectivity include methyl-2-hydroxyisobutyrate, ethyl-2-hydroxyisobutyrate, propyl-2-hydroxyisobutyrate and butyl- Isobutyrate and the like. Specific examples of the organic acid salt include ammonium acetate (CH ₃ CO ₂ NH ₄ ), sodium acetate (CH ₃ CO ₂ Na) and potassium acetate (CH ₃ CO ₂ K), metal salts such as CuSO ₄ , CuO, _{Cu (NO 3) 2, CuCl} , CuF 2, FeSO 4, Fe (NO 3) 2, AgNO 3, NiSO 4, Rh 2 O 3, and the inorganic salts KF, LiF, NaF, CsF, NH 4 BF 4, AlF ₃ , and the like. However, it is needless to say that the present invention can not be limited by the kind of the additive and the amount of the additive.

The acid used for etching in semiconductor processing is strong acid, and it is very volatile and generates toxic fumes. This strong acid not only threatens the safety of the workers, but also requires a more rigorous and strict process control of the semiconductor process due to the danger thereof, and a safety device must be built to prepare for the accident. And the risk of industrial accidents.

The inventors of the present invention have continuously conducted studies to improve the safety of strong acids which are highly toxic and difficult to handle. As a result, it has been found that the volatility of strong inorganic acid is remarkably reduced when urea is contained to satisfy Relation 1.

Specifically, the etching composition according to an embodiment of the present invention may contain water and may further contain a first inorganic acid and urea to satisfy Relation 1, and the etching composition containing the first inorganic acid, urea, 2 can be satisfied.

(Relational expression 2)

P _acid (es-ref) < 0.1 * P _acid (ac-ref)

In the relational expression P 2 _acid (es-ref) is a partial pressure (25 ℃, 1atm basis) of the first mineral acid in the etching composition in the same amount of the first inorganic acid, urea and water formed based etching composition of the present invention, _acid P (ac- ref) is the partial pressure (based on 25 캜, 1 atm) of the first inorganic acid in the reference inorganic acid composition composed of the same amount of the first inorganic acid and water as the etching composition of the present invention. That is, the reference inorganic acid composition is a composition comprising the same amount of the first inorganic acid and water as the reference etching composition. At this time, the partial pressures of the reference etch composition and the reference inorganic acid composition may be values measured according to ASTM D2879: 10, respectively.

When the partial pressure of the first inorganic acid is taken into account, the first inorganic acid partial pressure of the reference etching composition may have a significantly lower value than the first inorganic acid partial pressure of the reference inorganic acid composition, 1 The inorganic acid partial pressure can be a value substantially close to zero and thus the fume generation of the first inorganic acid can be controlled with little or no fume generation.

The etching composition according to one embodiment of the present invention contains the first inorganic acid and the urea so as to satisfy the relational expression 1, thereby preventing the generation of toxic fumes of the first inorganic acid and preventing the fatal occurrence due to the toxicity of the strong acid It is possible to secure the stability and flexibility of the process design and management. Further, in the etching process, since the first inorganic acid is not freely free in a free state, that is, upon dynamic contact between the urea and the first inorganic acid, and a dynamic equilibrium state of urea and recombination, The etching selectivity with respect to the different etching target materials is exhibited highly efficiently, and the partial pressure of the first inorganic acid can satisfy the above-described relational expression 2 even during the etching process, thereby further improving the process safety.

The etching composition according to an embodiment of the present invention may be used for metal etching; Or for inorganic etching. The inorganic substance, which is a substance to be etched, may be selected from one or more of metal oxides, metal nitrides, semiconductors, semiconductor oxides and semiconductor nitrides. The metal may include a single metal, a solid solution of two or more metals or an intermetallic compound, and may contain intentionally impurities as required.

In detail, the etching composition according to an embodiment of the present invention may be for metal etching, and the metal may be a transition metal including a noble metal, a metal, or a mixture thereof. The transition metal may be at least one selected from the group consisting of Sc, Y, La, Ac, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Te, Re, Fe, Ru, Os, Ba, Ba, Ra, Zn, Cd, Pd, Pt, Cu, Ag, Au or a mixture thereof. The metal may be Li, Na, K, Rb, Cs, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi, Po or a mixture thereof.

The etching composition according to an embodiment of the present invention may include at least one of Sc, Y, La, Ac, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Te, Re, Ba, Ra, Zn, Cd, Al, Fe, Fe, Fe, Ba, Ba, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Li, And a nitride of an oxide of one or more selected metals selected from Ga, In, Tl, Ge, Sn, Pb, Sb, Bi and Po or a nitride of the metal (s).

In detail, the etching composition according to an embodiment of the present invention is a quaternary semiconductor including silicon (Si), germanium (Ge), or silicon germanium (SiGe); Group 3-5 semiconductors including gallium arsenide (GaAs), indium phosphide (InP), or gallium phosphide (GaP); Group 2-6 semiconductors including cadmium sulfide (CdS) or zinc telluride (ZnTe); And a group IV-VI semiconductor containing lead sulfide (PbS). Here, the semiconductor may be crystalline or amorphous, and the crystalline may be monocrystalline or polycrystalline.

In detail, the etching composition according to an embodiment of the present invention is a quaternary semiconductor including silicon (Si), germanium (Ge), or silicon germanium (SiGe); Group 3-5 semiconductors including gallium arsenide (GaAs), indium phosphide (InP), or gallium phosphide (GaP); Group 2-6 semiconductors including cadmium sulfide (CdS) or zinc telluride (ZnTe); And a group IV-VI semiconductor containing lead sulfide (PbS). The composition may be an oxide or nitride of a semiconductor selected from one or more selected from the group consisting of: At this time, the oxide or nitride may be crystalline or amorphous, and the crystalline may be single crystal or polycrystalline.

In detail, the etching composition according to an embodiment of the present invention may be a composition for etching an organic material including a photoresist.

, With the exception of phosphoric acid is the acid dissociation degree of each _{pK a1 = 2.12, pK a2 =} 7.21, pK a3 = two even second and third acid dissociation, that is H ₂ PO ₄ as a mineral acid of 12.67 ^- and ^{_{(Dihydrogen phosphate anion) HPO 4 2-}} ( Hydrogen phosphate anion is too low to contribute to etching in the etchant composition actually mixed with urea. Therefore, in the case of phosphoric acid, a composition having a molar ratio of phosphoric acid: urea of 1: 1 or more when forming the mixed composition with urea exhibits selective etching characteristics according to the present invention.

That is, when the first inorganic acid is phosphoric acid, even if the first inorganic acid is phosphoric acid and the amount of urea is smaller than that of the relational formula 1, etching selectivity equivalent to that in the case of containing urea based on the relational expression 1 The improvement of the ratio can be achieved.

Accordingly, the etching composition (II) according to one embodiment of the present invention contains phosphoric acid, urea, and water, and may contain urea of at least 1 mole based on 1 mole of phosphoric acid. As a specific example, it may contain 1 to 3 moles of urea based on 1 mole of phosphoric acid.

The etching composition (II) according to one embodiment of the present invention containing urea in an amount of 1 mole or more based on 1 mole of phosphoric acid. The etching composition (II) according to one embodiment of the present invention is also characterized in that polar bonding between phosphoric acid and urea, It is possible to have an extremely high etch selectivity of over 200 due to the etching of the material to be etched in a dynamic equilibrium state such as the breakaway of free phosphoric acid and the urea recombination and to have the anti-volatility characteristics satisfying the relation (2).

Depending on the acid reacting directly with the phosphoric acid etching target substance to form a reaction product, the etching target material may be a nitride, and the etching composition (II) according to an embodiment of the present invention may be a nitride etching composition. The nitride of the object to be etched may be any one selected from the group consisting of Sc, Y, La, Ac, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Te, Re, Fe, Ru, Os, In order to solve the above problems, the present invention provides a method of manufacturing a semiconductor device, comprising the steps of: A quaternary semiconductor including a nitride of one or more selected metals selected from Sn, Pb, Sb, Bi, and Po, or silicon (Si), germanium (Ge), or silicon germanium (SiGe); Group 3-5 semiconductors including gallium arsenide (GaAs), indium phosphide (InP), or gallium phosphide (GaP); Group 2-6 semiconductors including cadmium sulfide (CdS) or zinc telluride (ZnTe); And a group IV-VI semiconductor containing lead sulfide (PbS).

When nitrides of phosphoric acid are etched away by etching, the etching process is usually performed at a relatively high temperature of about 165 ° C. Such a high-temperature process not only increases the wafer defect rate, but also makes it difficult to manufacture a device susceptible to heat, such as a flexible device using an organic substrate.

However, surprisingly, in the case of the etching composition (II) according to one embodiment of the present invention containing urea in an amount of 1 mole or more based on 1 mole of phosphoric acid, it is preferable to use a low temperature of less than 100 캜, specifically a temperature of 25 to 70 캜, Even when the etching is performed at a temperature of 70 캜, it is possible to have an excellent etching rate of 100 to 500 Å / min. Accordingly, it can be used for nitride etching in the production of an electronic product or a display product including a flexible polymer substrate as its constituent element, and the thermal damage of the flexible substrate in the etching process can be prevented. As a non-limiting example of the flexible substrate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC), polypropylene (PP), triacetylcellulose (TAC) , Polyethersulfone (PES), polydimethylsiloxane (PDMS), or mixtures thereof.

As described above, the etching composition (II) according to one embodiment of the present invention containing urea of 1 mole or more based on 1 mole of phosphoric acid, specifically 1 to 4 moles of urea based on 1 mole of phosphoric acid is also based on the first inorganic acid The composition shares the technical idea with the above-mentioned composition and shows the effect of the present invention on the basis of the first inorganic acid. Thus, a detailed description thereof will be omitted. As an example, it is of course possible to further include a second acid, an additive and the like, analogous to those described above on the basis of the first inorganic acid, and may have the same or similar molar concentration as described above based on the first inorganic acid.

The etching composition according to an embodiment of the present invention is characterized in that in the static state, the urea and the first inorganic acid are polarly bonded to each other to inhibit the first inorganic acid itself from being manifested, And the etching of the substance to be etched can be performed. Accordingly, the etching composition according to an embodiment of the present invention can be used to etch the object to be etched within a range of etching conditions conventionally used in conventional semiconductor processes, The process conditions used in the step (pre-established etching process) may be applied as is or without significant technical modifications.

 An etching method according to an embodiment of the present invention includes an etching method using the above-described etching composition (including composition (II)). As described above, the etching composition according to an embodiment of the present invention can completely replace the inorganic acid used as a conventional etchant with a mixture of an inorganic acid and urea, and the etching ability of inorganic acid is exhibited in the conventionally established etching conditions There is an advantage that design change in the established manufacturing process is unnecessary.

The etching composition manufacturing method according to an embodiment of the present invention can be manufactured by mixing and stirring the raw materials including the first inorganic acid, urea, and water so as to satisfy the etching composition described above.

In semiconductor processes, etching compositions are also commonly used as cleaning fluids. Accordingly, the above-described etching composition may be a cleaning liquid for semiconductor processing. As a specific example, a cleaning liquid for semiconductor processing according to an embodiment of the present invention comprises inorganic acid; Urea; And water, and can satisfy the following relational expression (1 ').

(Relational expression 1 ')

N _hydrogen &lt; = N _{amine group}

In relation 1, N _hydrogen is the total number of moles of hydrogen of the inorganic acid contained in the cleaning liquid, and the N _{amine group} is the total number of moles of amine groups provided by urea.

In the relational formula 1 ', the inorganic acid may be an inorganic acid ordinarily used in a cleaning liquid of a semiconductor process, and specific examples thereof include monoesters of sulfuric acid, nitric acid, boric acid, hydrogen fluoride, phosphoric acid or hydrochloric acid; Or a mixture of two or more selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid and hydrogen fluoride.

The cleaning liquid according to an embodiment of the present invention can satisfy all of relational expression 1-1 and relational expression 2 because the cleaning liquid used in the above-described etching process for semiconductor processing is changed from cleaning to etching instead of etching. Compositions and additives similar to the composition. However, in the case of additives, it is needless to say that, in place of conventional additives used for etching, additives commonly used in cleaning liquids of semiconductor processing may be added.

The present invention includes a cleaning method using a cleaning liquid for semiconductor processing according to an embodiment of the present invention.

Hereinafter, an example of etching of a silicon oxide film, which is the etching process most commonly used in the semiconductor industry, is considered to be the most important etching characteristic in a technology development direction of high integration and miniaturization, and an example of etching of silicon nitride which requires a very high selection ratio in the manufacturing process , An etching of copper, which is a typical wiring material, in view of the fact that the etching composition of the present invention can etch a very wide variety of etching target materials by simply changing the kind of inorganic acid, Experiments have shown that the composition is excellent, but the etching composition according to an embodiment of the present invention can completely replace the inorganic acid, which is the etchant of the conventional etching composition, with inorganic acid and urea, and the etching property of the inorganic acid itself is not impaired , A remarkably good selectivity ratio, It should be understood that the present invention can not be construed as being limited by the illustrated embodiments.

(Example 1)

Transparent Electrode Etchant Composition

An etching composition was prepared by mixing sulfuric acid (H ₂ SO ₄ ) as a first inorganic acid, hydrochloric acid (HCl) as a second acid, urea (Urea, H ₂ NCONH ₂ , molecular weight 60.06) and water.

96.8 g of distilled water and 60.06 g of urea (1 mole of urea and 2 moles of amine group by urea) were added to 103.2 g of a 95 wt% concentrated sulfuric acid aqueous solution (1 mol of sulfuric acid and 2 mol of hydrogen by sulfuric acid) Urea aqueous solution. 260.06 g of the prepared sulfuric acid-urea aqueous solution, 260.06 g of a 35 wt% concentrated hydrochloric acid aqueous solution and 2080.48 g of distilled water were mixed to prepare a transparent electrode etching composition.

A reference etching composition consisting of water, sulfuric acid and urea in the same amount as the transparent electrode etching composition was prepared. In detail, 260.06 g of the produced sulfuric acid-urea aqueous solution and 2249.52 g of distilled water were mixed to prepare a reference etching composition.

A reference etching composition consisting of the same amount of water and sulfuric acid as the prepared transparent electrode etching composition was prepared. In detail, 103.2 g of 95% by weight concentrated sulfuric acid aqueous solution and 2346.32 g of distilled water were mixed to prepare a reference inorganic acid composition.

The partial pressure of sulfuric acid in the reference etching composition and the partial pressure of sulfuric acid in the reference inorganic acid composition were measured according to ASTM D2879: 10 at 25 캜 and 1 atm. As a result, the partial pressure of sulfuric acid in the reference etching composition was 0.432E- ¹⁸ mmHg, The partial pressure of sulfuric acid in the composition was 0.441E- ¹⁶ mmHg. From this, it can be seen that the volatilization of the inorganic acid is remarkably prevented by the combination of the urea and the inorganic acid. In the case of the reference inorganic acid composition, the smell of weak sulfuric acid can be sensed sensibly, but in the case of the reference etching composition containing urea in sulfuric acid, it was odorless at all.

(Example 2)

Oxide etch composition

At room temperature, 531 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) was mixed with 469 g of urea to prepare a hydrogen fluoride-urea aqueous solution. And 868.43 g of water was further mixed with 131.57 g of the hydrogen fluoride-urea aqueous solution to prepare an oxide etching etch composition. The pH of the etch composition for etching the oxide produced was 2.6, 25 ^o C partial pressure in the etching composition of hydrogen fluoride was 0.021 mmHg.

A standard inorganic acid composition consisting of water and hydrofluoric acid in the same amount as that of the etched oxide etching composition was prepared. Specifically, a reference inorganic acid composition was prepared by mixing 69.864 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) and 868.43 g of water. The partial pressure of hydrogen fluoride in the reference inorganic acid composition was 0.324 mmHg. In this case, too, the reference inorganic acid composition shows irritating odor peculiar to hydrogen fluoride, but the etching composition which is an aqueous solution of hydrogen fluoride-urea shows almost no odor and its toxicity is also lost.

(Example 3)

Oxide etch composition

At room temperature, 364 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) was mixed with 636 g of urea to prepare an aqueous hydrogen fluoride-urea solution. To 135.13 g of the hydrogen fluoride-urea aqueous solution, 864.87 g of water was further mixed to prepare an etching composition for oxide etching. The prepared oxide etch composition had a pH of 2.9 and a 25 ^° C partial pressure of hydrogen fluoride in the etch composition was 0.003 mmHg.

A standard inorganic acid composition consisting of water and hydrofluoric acid in the same amount as that of the etched oxide etching composition was prepared. 49.19 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) and 868.43 g of water were mixed to prepare a reference inorganic acid composition. The partial pressure of hydrogen fluoride in the reference inorganic acid composition was 0.279 mmHg.

(Example 4)

Oxide etch composition

At room temperature, 531 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) was mixed with 469 g of urea to prepare a hydrogen fluoride-urea aqueous solution. A mixture of 50 g of methyl-2-hydroxy isobutyrate, 30 g of iminodiacetic acid, 20 g of benzotriazole and 800 g of distilled water was mixed with 100 g of a hydrogen fluoride-urea aqueous solution at room temperature to perform an oxide etching Lt; / RTI &gt;

(Example 5)

Oxide etch composition

At room temperature, 364 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) was mixed with 636 g of urea to prepare an aqueous hydrogen fluoride-urea solution. 50 g of methyl-2-hydroxy-isobutyrate, 30 g of iminodiacetic acid, 20 g of benzotriazole and 800 g of distilled water were mixed at room temperature with 100 g of a hydrogen fluoride-urea aqueous solution to prepare an oxide To prepare an etching composition for etching.

(Example 6)

Silicon etching composition

An etching composition was prepared by mixing phosphoric acid (H ₃ PO ₄ ) as a first inorganic acid, nitric acid (HNO ₃ ) as a second acid, urea (Urea, H ₂ NCONH ₂ , molecular weight 60.06) and water.

84.64 g of distilled water and 60.06 g of urea (1 mole of urea and 2 moles of amine group by urea) were added to 115.3 g of a 85% by weight aqueous concentrated phosphoric acid solution (1 mol of phosphoric acid and 1 mol of hydrogen by phosphoric acid) Aqueous solution. 260 g of the prepared phosphoric acid-urea aqueous solution and 9.0 g of a 70 wt% nitric acid aqueous solution were mixed to prepare an etching composition for silicon etching.

A standard inorganic acid composition composed of the same amount of water, phosphoric acid and urea as the etching composition for silicon etching was prepared. In detail, 260 g of the prepared phosphoric acid-urea aqueous solution and 2.7 g of distilled water were mixed to prepare a reference etching composition.

A standard inorganic acid composition composed of the same amount of water and phosphoric acid as the etching composition for silicon etching was prepared. Specifically, 115.3 g of a 85% by weight aqueous concentrated phosphoric acid solution and 86.74 g of distilled water were mixed to prepare a reference inorganic acid composition.

The partial pressure of phosphoric acid in the reference etching composition and the partial pressure of phosphoric acid in the reference inorganic acid composition were measured according to ASTM D2879: 10 at 25 캜 and 1 atm. As a result, the partial pressure of phosphoric acid in the reference etching composition was 4.755E- ¹³ mmHg, The partial pressure of phosphoric acid in the composition was 3.558E- ¹¹ mmHg. In this case also, the user can feel the smell of weak phosphoric acid in the case of the reference inorganic acid composition, but in the case of the etching composition containing urea, the smell is odorless at all, and the skin irritation is much lost.

(Example 7)

Nitride etch composition

An etching composition was prepared by mixing phosphoric acid (H ₃ PO ₄ ) as a first inorganic acid, hydrochloric acid (HCl) as a second acid, urea (Urea, H ₂ NCONH ₂ , molecular weight 60.06) and water.

Specifically, 84.64 g of distilled water and 60.06 g of urea (1 mole of urea and 2 moles of amine group by urea) were added to 115.3 g of a 85% by weight aqueous concentrated phosphoric acid solution (1 mol of phosphoric acid and 1 mol of hydrogen by phosphoric acid) Phosphoric acid-urea aqueous solution. 260 g of the prepared phosphoric acid-urea aqueous solution and 260 g of a 35% by weight concentrated hydrochloric acid aqueous solution were mixed to prepare an etching composition for a nitride film etching.

A reference inorganic acid composition consisting of water, phosphoric acid and urea in the same amount as that of the etching composition for nitride etching was prepared. In detail, 260 g of the prepared phosphoric acid-urea aqueous solution and 169 g of distilled water were mixed to prepare a reference etching composition.

A standard inorganic acid composition composed of the same amount of water and phosphoric acid as that of the etching composition for etching the nitrided film was prepared. Specifically, a reference inorganic acid composition was prepared by mixing 115.3 g of a 85% by weight aqueous concentrated phosphoric acid solution and 253.64 g of distilled water.

At this time, the partial pressure of phosphoric acid in the reference etching composition was 3.511E- ¹⁵ mmHg, and the partial pressure of phosphoric acid in the reference inorganic acid composition was 5.407E- ¹³ mmHg.

(Comparative Example 1)

An etching solution of 3.4 wt% hydrogen peroxide (H ₂ O ₂ ), 10 wt% acetic acid (CH ₃ CO ₂ H), and 86.6 wt% distilled water was used.

(Comparative Example 2)

2.75 wt% aqueous hydrogen fluoride solution was used as an etchant.

(Comparative Example 3)

An aqueous solution of 30% by weight of ammonium bifluoride (NH ₄ HF ₂ ) was used as the etching composition.

(Comparative Example 4)

A 5% by weight aqueous hydrochloric acid solution was used as the etching composition.

(Comparative Example 5)

50 g of a 55% by weight hydrofluoric acid solution was mixed with 50 g of methyl-2-hydroxy-isobutyrate, 30 g of iminodiacetic acid, 20 g of benzotriazole and 850 g of distilled water at room temperature To prepare an etching composition (containing 2.75 wt% hydrogen fluoride).

(Comparative Example 6)

50 g of methyl-2-hydroxy-isobutyrate, 30 g of iminodiacetic acid, 20 g of benzotriazole and 600 g of distilled water were added to 300 g of ammonium bifluoride at room temperature To prepare an etching composition (containing 30% by weight ammonium bifluoride).

(Comparative Example 7)

An aqueous 10 wt% hydrogen fluoride solution was used as the etchant.

(Comparative Example 8)

An aqueous 85% by weight phosphoric acid solution was used as the etchant.

(Comparative Example 9)

115.3 g of an aqueous 85% by weight concentrated phosphoric acid solution, 9 g of nitric acid, and 253.64 g of distilled water were mixed to prepare a mineral acid composition.

(Test Example 1)

Etching of transparent electrode

In order to evaluate the etch rate, an indium tin oxide (hereinafter referred to as "ITO") substrate (hereinafter referred to as a transparent electrode sample) having a thickness of about 1500 Å and a patterned Cu / Ti After preparing a double-layer film substrate (hereinafter referred to as a copper specimen), the etching composition prepared in Example 1 was etched by spraying each of the transparent electrode specimen and the copper specimen at 45 ° C for 10 minutes.

FIG. 1 (a) is a result of etching and evaluation of a transparent electrode specimen and a copper specimen in the etching composition prepared in Example 1 at 45.degree. 1 (b) is a result of etching and evaluation of the transparent electrode specimen and the copper specimen, respectively, in the etchant prepared in Comparative Example 1 at 45 ° C. by the same method.

As can be seen from the comparison between Fig. 1 (a) and Fig. 1 (b), the etch rate of the etching solution for the transparent electrode to copper differs markedly from 740 Å / min to 4.5 Å / min, Etch selectivity ratio of 164 is very high. Therefore, it enhances the selectivity of the etching process for the desired film in complicated processes such as the manufacture of semiconductor thin film transistor, so that there is no residue after the etching process without damaging the photoresist in the etching process and the influence on aluminum and copper used as the bottom film It is possible to improve the productivity of a flat panel display or the like.

(Test Example 2)

Oxide etching

A silicon substrate having a silicon oxide film (SiO ₂ ) having a thickness of 1.8 탆 was exposed and then immersed in the etching composition prepared in Example 2, Example 3, Comparative Example 2, Comparative Example 3 or Comparative Example 4, The silicon oxide film was etched. FIG. 2 is a graph showing changes in the thickness of the silicon oxide film according to the etching time. As can be seen from FIG. 2, the etching compositions of Examples 2 and 3 exhibit a very efficient and quick- have. In particular, it can be seen that the etching composition of Example 2 has almost the same efficiency and fast etching rate as the 2.75 wt% hydrogen fluoride solution (Comparative Example 2). It can be seen from the results of Examples 2 and 3 that the etching rate can be precisely controlled by controlling the content of urea, and it can be seen that even when the content of urea is changed, the etching amount with time has excellent linearity have. Compared with Comparative Example 3, which is an ammonium bifluoride-based etching composition that is a flame retardant, even though the concentration of the etching composition prepared in the Example is remarkably low, it is almost equal to that of the ammonium bifluoride- Which is twice as high as the etching efficiency.

3 is an optical photograph showing the safety of an etching composition according to an embodiment of the present invention. In FIG. 3, a hydrogen fluoride-urea aqueous solution prepared by mixing 461 g of urea in 531 g of 55% by weight of hydrofluoric acid (55% by weight of HF aqueous solution) After immersing the fingers for at least 10 seconds, the skin damage caused by the etching composition was examined and it was confirmed that no permanent or temporary skin damage was caused by the hydrogen fluoride-urea aqueous solution.

A silicon substrate having a silicon oxide film (SiO ₂ ) having a thickness of 1.8 탆 and a silicon nitride film (SiN x) having a thickness of 0.15 탆 was exposed at the same time was prepared and etched in Example 4, Example 5, Comparative Example 5 or Comparative Example 6 The composition was used to etch the silicon oxide film under normal temperature and normal pressure.

FIG. 4 is a graph showing a change in thickness of an oxide film with respect to etching time during etching using the etching compositions of Example 4, Example 5, Comparative Example 5, or Comparative Example 6. FIG. And the change in thickness is measured.

As can be seen from FIGS. 4 and 5, it can be seen that Example 4 exhibits significantly faster and more efficient etching performance than the etching composition of Comparative Example 5. In addition, since the etching performance of the etching composition of Comparative Example 5 and the etching composition of Comparative Example 6 is shown in Example 5, it can be effectively used in a process requiring efficient etching while requiring a certain degree of buffering. Referring to FIG. 4, it can be seen that the etching compositions prepared in the example of the present invention exhibit a very rapid etching rate and efficiency to a degree that the etching of the silicon oxide film (SiO ₂ ) having a thickness of 1.8 μm is completed within 80 to 150 seconds.

Meanwhile, FIG. 5 is a graph showing changes in the thickness of the silicon nitride film by the etching compositions of Examples 4, 5, 5, and 6, and in the case of the etching composition prepared in one embodiment of the present invention, It can be seen that the etching amount for the silicon nitride film (SiN _x ) having a thickness of 0.15 μm is significantly lower than the etching amount for the oxide film (SiO ₂ ). Through the FIGS. 4 and 5, It can be seen that the etching selectivity ratio of the silicon nitride film to the silicon oxide film in the initial two minutes is 210 and that in the etching composition of Example 5 is 317 in the etching selectivity ratio to the silicon oxide film compared to the silicon nitride film, The etching selectivity is remarkably higher than that of the hydrogen fluoride-based etching composition. Further, in the case of the etching compositions of Examples 4 and 5, although the etch rate is controlled for the silicon oxide film according to the content of urea, it can be seen that there is no significant difference in the etching of the silicon nitride film. In the case of the hydrogen fluoride-based etching composition of Comparative Example 5, the etching composition still exhibited rapid etching performance relative to the silicon nitride film, and consequently, the etching selectivity ratio of hydrogen fluoride was low. In contrast, the etching composition of the present invention is relatively more efficient Etch selectivity of the etch selectivity.

(Test Example 3)

Silicon etching

A specimen having a silicon film (Si) having a thickness of 2.5 占 퐉 exposed on the silicon nitride film substrate and a silicon oxide film substrate having a thickness of 2.5 占 퐉 were prepared on the silicon nitride film substrate. Then, the etching composition for silicon etching of Example 6 and the inorganic acid The composition was used to etch each specimen. FIG. 6 is a graph showing the change in thickness of the silicon film with respect to the etching time. In the case of the etching composition for silicon etching of Example 6 and the inorganic acid composition of Comparative Example 9, have.

On the other hand, in the etching of the silicon oxide film, the etching amount for the silicon oxide film in the case of the etching composition for silicon etching of Example 6 is lowered, while the etching amount for the silicon oxide film in the inorganic acid composition of Comparative Example 9 is not significantly lowered. As a result, it can be seen that the etch selectivity ratio of the silicon oxide film to the silicon nitride film of Example 6 is higher than that of the silicon oxide film of the inorganic acid of Comparative Example 9,

(Test Example 4)

Nitride etch

After the silicon nitride samples (or less, the oxide film specimen) that is in the exposed silicon oxide film (SiO ₂₎ thickness of 5000Å on a thin glass plate and the thickness of 5000Å on a thin glass plate (Si ₃ N ₄₎ is exposed prepare the specimen (nitride film specimens) each , And each of the specimens was immersed in the etching composition prepared in Example 7, Comparative Example 7 or Comparative Example 8 to perform etching. At this time, the etching was performed at 65 ° C.

FIG. 8 is a graph showing a change in thickness of a nitride film sample with respect to an etching time, and FIG. 9 is a graph showing a change in thickness of an oxide film sample measured with an etching time using a nanometer.

As can be seen from FIG. 8, the etch rate of the nitride film was not less than 480 Å / min even at a very low temperature of 65 ° C. in the case of the etching composition of Example 7. In the case of the phosphoric acid aqueous solution of Comparative Example 8, min. &lt; / RTI &gt;

8 and 9, it can be seen that the nitride film is efficiently etched, and the oxide film has almost no etching effect, and its selectivity is very high at 240 (nitrate 240 Å etched, 1 Å oxide etched) 8 phosphoric acid solution is very low at a selectivity of less than 30 (0.7 A etch of oxide at 21 A of nitride).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (12)

A first inorganic acid; And urea,
1. An etching composition which satisfies the following relationship (1).
(Relational expression 1)
N _hydrogen ≤ N _{amine group} ≤ 4N _hydrogen
(In the relationship 1, N _hydrogen is the total number of moles of hydrogen of the first inorganic acid contained in the etching composition and N _{amine group} is the total number of moles of amine groups provided by urea) The method according to claim 1,
Wherein the first inorganic acid has a pKa of -10 to 7. The method according to claim 1,
The first inorganic acid is selected from the group consisting of mono-acid of sulfuric acid, nitric acid, boric acid, hydrogen fluoride, phosphoric acid or hydrochloric acid; Or a mixture of at least two selected from sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, boric acid and hydrogen fluoride. The method according to claim 1,
Wherein the composition further comprises an organic acid, a secondary acid which is a mineral acid different from the first inorganic acid or a mixed acid thereof. delete The method according to claim 1,
Wherein the etching composition further comprises water. The method according to claim 6,
Wherein the composition satisfies the following relationship (2).
(Relational expression 2)
P _acid (es-ref) < 0.1 * P _acid (ac-ref)
(In the equation 2 P _acid (es-ref) is 25 ℃ partial pressure of the first inorganic acids of the etch composition in the same amount of the first inorganic acid, urea and water formed based etching composition, P _acid (ac-ref) is the etch Lt; RTI ID = 0.0 &gt; 25 C &lt; / RTI &gt; of the first inorganic acid in the reference inorganic acid composition consisting of the first inorganic acid and water in the same amount as the composition) Phosphoric acid, urea, and water, and containing 1 to 3 moles of urea based on 1 mole of phosphoric acid. The method according to any one of claims 1 to 4 and 6 to 8,
Wherein the composition further comprises one or more additives selected from an oxidizing agent, a surfactant, a metal salt, a defoamer, a corrosion inhibitor and a water-soluble organic solvent. The method according to any one of claims 1 to 4 and 6 to 7,
Wherein the composition is a metal etchant or an inorganic etchant. A method of etching using the etching composition according to any one of claims 1 to 4 and 6 to 8. Inorganic acids; Urea; And water, and satisfies the following relational expression (1 ').
(Relational expression 1 ')
N _hydrogen ≤ N _{amine group} ≤ 4N _hydrogen
(In the relational formula 1, N _hydrogen is the total number of moles of hydrogen of the first inorganic acid contained in the cleaning liquid and N _{amine group} is the total number of moles of amine groups provided by urea)

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