KR102571430B1 - Etching solution for silicon substrate and method for preparing semiconductor device using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a semiconductor device using a silicon substrate etching solution, and more particularly, by controlling the concentration of a silane compound (silicon) in a silicon substrate etching solution, etching a silicon nitride film compared to a silicon oxide film when etching a silicon nitride film. It relates to a silicon substrate etching solution capable of improving selectivity and a method for manufacturing a semiconductor device including an etching process performed using the same.

Description

Silicon substrate etching solution and method for manufacturing a semiconductor device using the same

The present invention relates to a method for manufacturing a semiconductor device using a silicon substrate etching solution, and more particularly, by controlling the concentration of a silane compound (silicon) in a silicon substrate etching solution, etching a silicon nitride film compared to a silicon oxide film when etching a silicon nitride film. It relates to a silicon substrate etching solution capable of improving selectivity and a method for manufacturing a semiconductor device including an etching process performed using the same.

Currently, there are various methods of etching the silicon nitride film and the silicon oxide film, but dry etching and wet etching are the most commonly used methods.

The dry etching method is an etching method using a gas and has the advantage of being superior to the wet etching method in isotropy, but the wet etching method is widely used in that the productivity is much lower than the wet etching method and is expensive.

In general, as a wet etching method, a method using phosphoric acid as an etching solution is well known. At this time, when only pure phosphoric acid is used to etch the silicon nitride film, as the device is miniaturized, not only the silicon nitride film but also the silicon oxide film is etched, which may cause problems such as occurrence of various defects and pattern abnormalities. need to be further lowered.

An object of the present invention is to provide a silicon substrate etching solution capable of improving the etching selectivity of a silicon nitride film to a silicon oxide film by lowering the etching rate for a silicon oxide film by increasing the concentration of a silane compound (silicon) in the silicon substrate etching solution. to be

In addition, an object of the present invention is to provide a silicon substrate etching solution that can prevent the etching rate of not only a silicon oxide film but also a silicon nitride film from being lowered or silicon-based particles from being generated.

In addition, an object of the present invention is to provide a method of manufacturing a semiconductor device including an etching process performed using the above-described silicon substrate etching solution.

In order to solve the above-described technical problem, according to one aspect of the present invention, a silicon substrate etching solution including an inorganic acid aqueous solution and a silicon additive represented by Formula 1 below is provided.

[Formula 1]

here,

Z is represented by Formula 2 below,

[Formula 2]

X ₁ and X ₂ are each independently oxygen or sulfur;

R ₁ to R ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one hetero atom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydroxy, amino, halogen, sulfone, phosphonic, phosphoric, thiol, selected from alkoxy, amide, ester, acid anhydride, acyl halide, cyano, carboxyl and azole;

Y ₁ to Y ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one heteroatom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydroxy, amino, halogen, sulfone, phosphonic, phosphoric, thiol, selected from alkoxy, amide, ester, acid anhydride, acyl halide, cyano, carboxyl and azole;

n is an integer between 1 and 5;

In addition, according to another aspect of the present invention, a method of manufacturing a semiconductor device including an etching process performed using the above-described silicon substrate etching solution is provided.

The silicon additive in the silicon substrate etching solution according to the present invention can be decomposed into an amide (eg, when X ₁ and X ₂ in Chemical Formula 1 are oxygen) and a silane compound (eg, silicic acid) under etching conditions, , The silane compound can lower the etching rate for the silicon oxide film by increasing the concentration of the silane compound (silicon) in the silicon substrate etching solution.

At this time, the silicon additive used herein is a cyclic compound, and the decomposition rate of the silane moiety and the amide moiety is slower than that of a compound in which a silane moiety and an amide moiety are bonded in a chain form. The rate of release of the compound may be delayed.

Accordingly, since the concentration of the silane compound (silicon) in the silicon substrate etching solution is prevented from rapidly increasing, etching efficiency may be prevented from deteriorating as the etching rate of the silicon nitride film as well as the silicon oxide film is reduced.

In addition, it is possible to prevent an excessively increased silane compound in a silicon substrate etching solution from acting as a source of silicon-based particles.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the following examples. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various forms different from each other, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

Hereinafter, a silicon substrate etching solution according to the present invention will be described in detail.

According to one aspect of the present invention, a silicon substrate etching solution containing an aqueous inorganic acid solution and a silicon additive is provided.

The silicon substrate to be etched by the silicon substrate etching solution according to the present invention preferably includes at least a silicon nitride film (SI _x O _y N _z ), and a silicon oxide film and a silicon nitride film (Si _x N _y , SI _x O _y N _z ) can be included simultaneously. also. In the case of a silicon substrate including a silicon oxide layer and a silicon nitride layer, the silicon oxide layer and the silicon nitride layer may be alternately stacked or stacked in different regions.

Here, the silicon oxide film is a SOD (Spin On Dielectric) film, HDP (High Density Plasma) film, thermal oxide film, BPSG (Borophosphate Silicate Glass) film, PSG (Phospho Silicate Glass) film depending on the use and material type. , BSG (Boro Silicate Glass) film, PSZ (Polysilazane) film, FSG (Fluorinated Silicate Glass) film, LP-TEOS (Low Pressure Tetra Ethyl Ortho Silicate) film, PETEOS (Plasma Enhanced Tetra Ethyl Ortho Silicate) film, HTO (High Temperature Oxide) film, MTO (Medium Temperature Oxide) film, USG (Undopped Silicate Glass) film, SOG (Spin On Glass) film, APL (Advanced Planarization Layer) film, ALD (Atomic Layer Deposition) film, PE-oxide film (Plasma Enhanced oxide) or O ₃ -TEOS (O ₃ -Tetra Ethyl Ortho Silicate).

Here, the inorganic acid aqueous solution may be an aqueous solution containing at least one inorganic acid selected from sulfuric acid, nitric acid, phosphoric acid, silicic acid, hydrofluoric acid, boric acid, hydrochloric acid, and perchloric acid. In addition, phosphoric anhydride, pyrophosphoric acid, or polyphosphoric acid may be used other than the above-mentioned inorganic acids.

The inorganic acid aqueous solution is a component that maintains the pH of the etching solution and suppresses the transformation of various types of silane compounds present in the etching solution into silicon-based particles.

In one embodiment, the inorganic acid aqueous solution is preferably included in an amount of 60 to 90 parts by weight based on 100 parts by weight of the silicon substrate etching solution.

If the content of the inorganic acid solution is less than 60 parts by weight with respect to 100 parts by weight of the silicon substrate etching solution, the etching rate of the silicon nitride film is lowered so that the silicon nitride film is not sufficiently etched or the silicon nitride film etching process efficiency is reduced. There is a concern.

On the other hand, when the content of the aqueous inorganic acid solution exceeds 90 parts by weight with respect to 100 parts by weight of the silicon substrate etching solution, the etching rate of the silicon nitride film excessively increases and even the silicon oxide film is etched quickly. The selectivity may be lowered, and defects of the silicon substrate may be caused due to etching of the silicon oxide film.

A silicon substrate etching solution according to an embodiment of the present invention may include a silicon additive represented by Chemical Formula 1 below to increase a selectivity of a silicon nitride film to a silicon oxide film.

[Formula 1]

here,

Z is represented by Formula 2 below,

[Formula 2]

Here, X ₁ and X ₂ are each independently oxygen or sulfur, and R ₁ to R ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, including at least one heteroatom. C ₂ -C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydrophilic functional groups and Y ₁ to Y ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one heteroatom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydrophilic functional groups.

The hydrophilic functional group bonded to the silicon atom means a hydroxyl group or a functional group that can be substituted with a hydroxyl group under the pH condition of an inorganic acid aqueous solution.

Here, non-limiting examples of the functional group that can be substituted with a hydroxyl group under the pH condition of the inorganic acid aqueous solution include amino, halogen, sulfone, phosphonic, phosphoric, thiol, alkoxy, amide, ester, acid anhydride, acyl halide, cyano, There are carboxyl and azole, and it is not necessarily limited to the above-mentioned functional group, and it will be understood that it includes any functional group capable of being substituted with a hydroxyl group under the pH condition of an aqueous inorganic acid solution.

The silicon additive in the silicon substrate etching solution according to the present invention is amide (eg, when X ₁ and X ₂ in Formula 1 are oxygen) and It can be decomposed into a silane compound (eg, silicic acid), and the silane compound can decrease the etching rate of the silicon oxide layer by increasing the concentration of the silane compound (silicon) in the silicon substrate etching solution.

At this time, the silicon additive used herein is a cyclic compound, and the decomposition rate of the silane moiety and the amide moiety is slower than that of a compound in which a silane moiety and an amide moiety are bonded in a chain form. The rate of release of the compound may be delayed.

Accordingly, since the concentration of the silane compound (silicon) in the silicon substrate etching solution is prevented from rapidly increasing, etching efficiency may be prevented from deteriorating as the etching rate of the silicon nitride film as well as the silicon oxide film is reduced.

In addition, by controlling the decomposition rate of the silicon additive, it is possible to prevent the silane compound (silicon) from acting as a source of silicon-based particles.

Also, the number of repeating units Z represented by Formula 2 is preferably 1 to 5 (ie, n is an integer between 1 and 5). In the absence of the repeating unit Z represented by Formula 2, as the silicone additive represented by Formula 1 forms a 4-membered ring, strain-induced instability increases and there is a risk of easy decomposition. In addition, when the number of repeating units represented by Chemical Formula 2 exceeds 5, the ring size of the silicone additive represented by Chemical Formula 1 becomes excessively large and can be easily decomposed.

In addition, the silicon substrate etching solution according to another embodiment of the present invention may further include a silicon additive represented by Chemical Formula 3 and/or Chemical Formula 4.

[Formula 3]

Here, R ₁ to R ₄ are each independently a hydrophilic functional group, or hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one heteroatom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl, silyloxy and siloxane.

[Formula 4]

Here, R ₅ to R ₁₀ are each independently a hydrophilic functional group, or hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one heteroatom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl, silyloxy and a functional group selected from siloxane, n is It is an integer from 1 to 5.

Halogen herein means fluoro (-F), chloro (-Cl), bromo (-Br) or iodo (-I), and haloalkyl means an alkyl substituted with the aforementioned halogen. For example, halomethyl means methyl in which at least one of the hydrogens of methyl is replaced with a halogen (-CH ₂ X, -CHX ₂ or -CX ₃ ).

In addition, alkoxy here refers to both an -O-(alkyl) group and an -O-(unsubstituted cycloalkyl) group, and is a straight-chain or branched hydrocarbon having at least one ether group and 1 to 10 carbon atoms.

Specifically, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like.

When R _a (wherein a is an integer selected from 1 to 4) is alkenyl or alkynyl, the sp ² -hybrid carbon of alkenyl or the sp 2 -hybrid carbon of alkynyl is directly bonded or the sp ² -hybrid carbon of alkenyl It may be indirectly bonded by the sp ³ -hybridized carbon of alkyl bonded to the hybridized carbon or the sp-hybridized carbon of alkynyl.

A C _a -C _b functional group herein means a functional group having a to b carbon atoms. For example, C _a -C _b alkyl refers to a saturated aliphatic group having from a to b carbon atoms, including straight chain alkyl and branched alkyl and the like. A straight chain or branched alkyl has no more than 10 (eg C ₁ -C ₁₀ straight chain, C ₃ -C ₁₀ branched), preferably no more than 4, more preferably no more than 3 carbon atoms in its main chain. have

Specifically, alkyl is methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl, pent-1-yl, pent-2-yl, pent-3-yl , 3-methylbut-1-yl, 3-methylbut-2-yl, 2-methylbut-2-yl, 2,2,2-trimethyleth-1-yl, n-hexyl, n-heptyl and n -may be octyl.

As used herein, unless otherwise defined, aryl refers to an unsaturated aromatic ring comprising a single ring or multiple rings (preferably 1 to 4 rings) linked to each other by conjugated or covalent bonds. Non-limiting examples of aryl include phenyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2- Anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4--phenanthrenyl, 9-phenanthrenyl, 1-pyrenyl, 2- pyrenyl and 4-pyrenyl; and the like.

As used herein, heteroaryl refers to a functional group in which one or more carbon atoms in the aryl defined above are substituted with a non-carbon atom such as nitrogen, oxygen or sulfur.

Non-limiting examples of heteroaryl include furyl, tetrahydrofuryl, pyrrolyl, pyrrolidinyl, thienyl, tetrahydrothienyl, oxazolyl , isoxazolyl, triazolyl, thiazolyl, isothiazolyl, pyrazolyl, pyrazolidinyl, oxadiazolyl, thiadiazolyl (thiadiazolyl), imidazolyl, imidazolinyl, pyridyl, pyridaziyl, triazinyl, piperidinyl, morpholinyl ), thiomorpholinyl, pyrazinyl, piperainyl, pyrimidinyl, naphthyridinyl, benzofuranyl, benzothienyl, indolyl , indolinyl, indolizinil, indazolyl, quinolinyl, quinolinyl, isoquinolinyl, cinolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, teridinyl, quinuclidinyl, carbazolyl, acridinyl, phenazinyl, phenothizinyl, phenoxazinyl, purinyl, benzimidazolyl and benzothiazolyl; and the like; There are conjugated analogues.

In the present application, aralkyl is a functional group in which aryl is substituted on the carbon of alkyl, and is a general term for -(CH ₂ ) _n Ar. Examples of aralkyl include benzyl (-CH ₂ C ₆ H ₅ ) or phenethyl (-CH ₂ CH ₂ C ₆ H ₅ ).

Cycloalkyl (cycloalkyl) or cycloalkyl containing a heteroatom (heterocycloalkyl) herein will be understood as a cyclic structure of alkyl or heteroalkyl, respectively, unless otherwise defined.

Non-limiting examples of cycloalkyl include cyclopentyl, cyclohexyl, 1-cyclohexenyl, 3-cyclohexenyl and cycloheptyl.

Non-limiting examples of cycloalkyls containing heteroatoms include 1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4- Morpholinil, 3-morpholinyl, tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl, 1-piperazinyl and 2 - Piperazinil, etc.

In addition, cycloalkyl or cycloalkyl containing a hetero atom may have a form in which a cycloalkyl, a cycloalkyl containing a hetero atom, an aryl, or a hetero aryl are conjugated or covalently bonded thereto.

The aforementioned silicon additive is preferably present in an amount of 100 to 10,000 ppm in the silicon substrate etching solution.

When the silicon additive is present in an amount of less than 100 ppm in the silicon substrate etching solution, the amount of the silane compound decomposed and released from the silicon additive under etching conditions is excessively small, and the effect of increasing the selectivity of the silicon nitride film to the silicon oxide film may be insignificant. .

On the other hand, when the amount of the silicon additive in the silicon substrate etching solution exceeds 10,000 ppm, the amount of the silane compound decomposed and released from the silicon additive under etching conditions is excessively increased, which reduces the etching rate of not only the silicon oxide film but also the silicon nitride film. can happen In addition, the silane compound in the etching solution may itself act as a source of silicon-based particles.

The silicon substrate etching solution according to an embodiment of the present invention may further include a fluorine-containing compound in order to compensate for the etching rate of the silicon nitride film, which is reduced due to the use of the silicon additive, and to improve the efficiency of the overall etching process. .

A fluorine-containing compound herein refers to any type of compound capable of dissociating fluorine ions.

In one embodiment, the fluorine-containing compound is at least one selected from hydrogen fluoride, ammonium fluoride, ammonium bifluoride and ammonium bifluoride.

Also, in another embodiment, the fluorine-containing compound may be a compound in which an organic cation and a fluorine anion are ionically bonded.

For example, the fluorine-containing compound may be a compound in which an alkylammonium and a fluorine-based anion are ionically bonded. Here, the alkylammonium is ammonium having at least one alkyl group and may have up to four alkyl groups. The definition of the alkyl group has been described above.

In another example, the fluorine-containing compound is an alkylpyrroleium, an alkylimidazolium, an alkylpyrazolium, an alkyloxazolium, an alkylthiazolium, an alkylpyridinium, an alkylpyrimidinium, an alkylpyridazinium, an alkylpyrazolium. An organic cation selected from zinium, alkylpyrrolidinium, alkylphosphonium, alkylmorphorinium and alkylpiperidinium, and fluorophosphate, fluoroalkyl-fluorophosphate, fluoroborate and fluoroalkyl-fluoro It may be an ionic liquid in which a fluorine-based anion selected from Roborate is ionically bonded.

Compared to hydrogen fluoride or ammonium fluoride, which are generally used as fluorine-containing compounds in silicon substrate etching solutions, fluorine-containing compounds provided in the form of ionic liquids have a higher boiling point and decomposition temperature, so they are decomposed during the etching process performed at high temperatures. There is an advantage in that there is little risk of changing the composition of the etching solution according to.

According to another aspect of the present invention, a method of manufacturing a semiconductor device including an etching process performed using the above-described silicon substrate etching solution is provided.

According to the present manufacturing method, it is possible to manufacture a semiconductor device by performing a selective etching process on a silicon nitride film using the above-described etching solution on a silicon substrate including at least a silicon nitride film (SI _x O _y N _z ).

A silicon substrate used for manufacturing a semiconductor device may include a silicon nitride layer (SI _x O _y N _z ) or may include a silicon oxide layer and a silicon nitride layer (Si _x N _y , SI _x O _y N _z ) at the same time. also. In the case of a silicon substrate including a silicon oxide layer and a silicon nitride layer, the silicon oxide layer and the silicon nitride layer may be alternately stacked or stacked in different regions.

The method of manufacturing a semiconductor device according to the present invention requires selective removal of a silicon nitride film without loss of a silicon oxide film during a device separation process of a flash memory device, a device separation process of a DRAM device, or a diode formation process of a phase change memory device. It can be carried out by using the silicon substrate etching solution described above in the process step.

Hereinafter, specific embodiments of the present invention are presented. However, the embodiments described below are only intended to specifically illustrate or explain the present invention, and the present invention should not be limited thereto.

Composition of the silicon substrate etching solution

Example 1

A silicon substrate etching solution was prepared by mixing 85% by weight of phosphoric acid, 1,000 ppm of a silicon additive represented by Chemical Formula 4, and the remaining amount of water.

[Formula 4]

Example 2

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that 5,000 ppm of a silicon additive represented by Formula 5 was used.

[Formula 5]

Example 3

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that the silicon additive represented by Formula 6 was used.

[Formula 6]

Example 4

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that the silicon additive represented by Formula 7 was used.

[Formula 7]

Example 5

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that 90 ppm of the silicon additive was used.

Example 6

A silicon substrate etching solution was prepared in the same manner as in Example 2, except that 11,000 ppm of the silicon additive was used.

Example 7

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that the silicon additive represented by Chemical Formula 8 was used.

[Formula 8]

Comparative Example 1

A silicon substrate etching solution was prepared in the same manner as in Example 1 except that the silicon additive was not used.

Comparative Example 2

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that triethoxysilane was used as a silicon additive.

Comparative Example 3

A silicon substrate etching solution was prepared in the same manner as in Example 1, except that the silicon additive represented by Formula 9 was used.

[Formula 9]

Experimental Example 1

After heating the silicon substrate etching solution having the composition according to each Example and Comparative Example to 165 ° C., a silicon oxide layer and a silicon nitride layer having a thickness of 500 Å, respectively, were immersed in the heated etching solution for 3 minutes and etched. At this time, the pH of the etching solution heated to 165 ℃ was measured within the range of 2.0 ~ 2.5.

The thicknesses of the silicon oxide film and the silicon nitride film before and after etching were measured using an ellipsometer (Nano-View, SE MG-1000; Ellipsometry), and the measurement result is an average value of 5 measurements. The etching rate is a value calculated by dividing the thickness difference between the silicon oxide film and the silicon nitride film before and after etching by the etching time (3 minutes).

In addition, after the etching was completed, the etching solution was analyzed with a particle size analyzer to measure the average diameter of silicon-based particles present in the etching solution.

The measured etching rates and average diameters of silicon-based particles in the etching solution are shown in Table 1 below.

division silicon-based particles
Average diameter (μm) silicon oxide film
Etch rate (Å/min) silicon nitride film
Etch rate (Å/min) Example 1 <0.01 4.61 91.16 Example 2 <0.01 1.02 92.00 Example 3 <0.01 15.79 91.87 Example 4 <0.01 14.44 90.99 Example 5 <0.01 28.95 91.44 Example 6 0.15 > deposition 91.79 Example 7 <0.01 4.70 91.20 Comparative Example 1 <0.01 30.24 91.36 Comparative Example 2 3.0 > 13.10 91.61 Comparative Example 3 1.5 > 7.97 92.01

Referring to the results of Table 1, when a silane compound capable of increasing the silicon concentration in the etching solution was used as the silicon additive as in Comparative Example 2, compared to the case where a separate silicon additive was not used as in Comparative Example 1, the silicon oxide film As a result, it is possible to improve the etching selectivity of the silicon nitride film to the silicon oxide film by lowering the etching rate. However, when a general chain-type silane compound is used as a silicon additive as in Comparative Example 2, it can be confirmed that silicon-based particles have grown.

Meanwhile, according to Examples 1 to 4, the silane compound (silicic acid) can be decomposed under etching conditions by using a cyclic silane compound. As such, the etching rate for the silicon oxide film is lowered by the concentration of silicon in the etching solution controlled by the delayed release of the silane compound (silicic acid) into the etching solution, and as a result, it can be seen that the etching selectivity for the silicon nitride film versus the silicon oxide film is improved. .

In addition, according to Examples 1 to 4, the concentration of the silane compound (silicic acid) in the etching solution may be prevented from excessively increasing as the silane compound (silicic acid) is released into the etching solution with a delay. Accordingly, unlike Comparative Example 2 and Comparative Example 3, it can be confirmed that silicon-based particles of several micrometers did not grow.

On the other hand, the content of the silicon additive in the etching solution according to Example 5 is 90 ppm, and the content of the silicon additive in the etching solution compared to Examples 1 to 4 is relatively low, indicating that the effect of reducing the etching rate for the silicon oxide film is insignificant. You can check.

In addition, the content of the silicon additive in the etching solution according to Example 6 is 11,000 ppm, and the content of the silicon additive in the etching solution is excessive compared to Examples 1 to 4, so that the silicon additive is deposited on the silicon oxide film, so that the silicon oxide film It can be confirmed that the measurement of the etching rate of is impossible.

Although one embodiment of the present invention has been described above, those skilled in the art can add, change, delete, or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention can be variously modified and changed by the like, and this will also be said to be included within the scope of the present invention.

Claims (7)

inorganic acid aqueous solution; and
A silicone additive represented by Formula 1 below;
including,
Silicon Substrate Etch Solution:
[Formula 1]

here,
Z is represented by Formula 2 below,
[Formula 2]

X ₁ and X ₂ are each independently oxygen or sulfur;
R ₁ to R ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one hetero atom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydroxy, amino, halogen, sulfone, phosphonic, phosphoric, thiol, selected from alkoxy, amide, ester, acid anhydride, acyl halide, cyano, carboxyl and azole;
Y ₁ to Y ₄ are each independently hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ -C ₁₀ heteroalkyl containing at least one heteroatom, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl and hydroxy, amino, halogen, sulfone, phosphonic, phosphoric, thiol, selected from alkoxy, amide, ester, acid anhydride, acyl halide, cyano, carboxyl and azole;
n is an integer between 1 and 5;
According to claim 1,
The inorganic acid aqueous solution is an aqueous solution containing at least one inorganic acid selected from sulfuric acid, nitric acid, phosphoric acid, silicic acid, hydrofluoric acid, boric acid, hydrochloric acid, perchloric acid, anhydrous phosphoric acid, pyrophosphoric acid and polyphosphoric acid,
Silicon substrate etching solution.
According to claim 1,
The silicon additive in the silicon substrate etching solution is contained in 100 to 10,000 ppm,
Silicon substrate etching solution.
According to claim 1,
The silicon substrate etching solution is for etching a single film made of a silicon oxide film or a multilayer film including a silicon oxide film and a silicon nitride film at the same time,
Silicon substrate etching solution.
According to claim 1,
The silicon substrate etching solution further comprises at least one fluorine-containing compound selected from hydrogen fluoride, ammonium fluoride, ammonium bifluoride and ammonium hydrogen fluoride.
Silicon substrate etching solution.
According to claim 1,
The silicon substrate etching solution further comprises a fluorine-containing compound having an ionic bond of organic cations and fluorine anions.
Silicon substrate etching solution.
A method of manufacturing a semiconductor device comprising an etching process performed using the silicon substrate etching solution according to any one of claims 1 to 6.