KR102436182B1 - Method for etching semiconductor device and apparatus for etching semiconductor device - Google Patents

Abstract

The present invention relates to a method for etching a semiconductor device and an apparatus for manufacturing the same, wherein the method for etching a semiconductor device includes heating an inorganic acid, adding a silane compound to the heated inorganic acid, and reacting the inorganic acid with the silane compound including the step of making
In the etching method of the semiconductor device, when used as an additive in the etching composition, the etching selectivity of the nitride film to the oxide film of the etching composition can be increased, and the EFH can be easily controlled by controlling the etching rate of the oxide film, and when the nitride film is removed, the oxide film A silane inorganic acid salt capable of preventing deterioration of electrical properties due to damage to the film quality or etching of the oxide film and preventing the generation of particles can be prepared in high yield through a simple method.

Description

A semiconductor device etching method and a semiconductor device etching apparatus TECHNICAL FIELD

The present invention relates to a method for etching a semiconductor device and an etching apparatus for a semiconductor device, and more particularly, in etching a silicon nitride film and a silicon oxide film with high-temperature phosphoric acid, by controlling the high-temperature phosphoric acid to selectively select the silicon nitride film with respect to the silicon oxide film. The present invention relates to a method for etching a semiconductor device and an etching apparatus for a semiconductor device that do not cause problems such as abnormal growth of silicon due to an increase in silicon concentration while etching.

In a semiconductor manufacturing process, an oxide film such as a silicon oxide film (SiO ₂ ) and a nitride film such as a silicon nitride film (SiN _x ) are used as representative insulating films, each alone or by alternately stacking one or more layers. In addition, these oxide films and nitride films are also used as hard masks for forming conductive patterns such as metal wiring.

In a wet etching process for removing the nitride layer, a mixture of phosphoric acid and deionized water is generally used, and these mixtures are mainly used in a process known as a high-temperature phosphoric acid process. In the high-temperature phosphoric acid process, etching is performed by heating the mixture to a high temperature of about 100 to 170° C., and the phosphoric acid heated to a high temperature is easy to etch a silicon nitride layer or a silicon oxide layer. It is known that the etching rate of the silicon nitride layer through the high-temperature phosphoric acid process is about 50 to 70 Å/min, and the etching rate of the silicon thermal oxide layer is about 2 to 5 Å/min.

An object of the present invention is to etch a silicon nitride film and a silicon oxide film with high-temperature phosphoric acid, while selectively etching the silicon nitride film with respect to the silicon oxide film by controlling the high-temperature phosphoric acid, without causing problems such as abnormal growth of silicon due to an increase in silicon concentration. To provide a method for etching a semiconductor device.

Another object of the present invention is to provide an etching apparatus for a semiconductor device.

According to an embodiment of the present invention, the step of heating after supplying an etching composition to an etching bath, adding a silicon additive to the etching composition, etching a semiconductor device in the etching bath, and the etching composition It provides a method of etching a semiconductor device comprising the step of adjusting the temperature by supplementing the water.

The heating of the etching composition may include heating the etching composition to 150 to 200°C.

The adding of the silicone additive may include adding the silicone additive in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the etching composition.

The water may be deionized water (DIW).

The amount of water evaporated in any one step selected from the group consisting of heating the etching composition, adding a silicon additive to the etching composition, etching the semiconductor device, and combinations thereof. It may be supplementary.

The method of etching the semiconductor device may further include preheating the etching composition.

The preheating of the etching composition may include preheating the etching composition to 100 to 140°C.

The etching method of the semiconductor device may be to drain a portion of the etching composition used in the step of etching the semiconductor device, and then repeat the etching method of the semiconductor device.

The etching method of the semiconductor device may be to overflow a part of the etching composition used in the step of etching the semiconductor device, and then repeat the etching method of the semiconductor device.

The drain or overflow of the etching composition may be drained or overflowed in an amount of 10 to 30 wt% based on the total weight of the etching composition.

The etching composition may include an inorganic acid.

The inorganic acid may be an aqueous inorganic acid solution, and the inorganic acid aqueous solution may include 70 to 99% by weight of the inorganic acid and the remaining amount of water based on the total weight of the inorganic acid aqueous solution.

The inorganic acid may be any one selected from the group consisting of sulfuric acid, fuming sulfuric acid, nitric acid, phosphoric acid, phosphoric anhydride, and mixtures thereof.

The silicone additive may be a silane inorganic acid salt.

According to another embodiment of the present invention, an etching bath for etching a semiconductor device using an etching composition, a first raw material supply unit for supplying the etching composition to the etching bath, and a first material for supplying a silicon additive to the etching bath 2 It provides an etching apparatus for a semiconductor device including a raw material supply unit, a water replenishment unit for replenishing water in the etching tank, and a heating unit for heating the etching composition.

The semiconductor device etching apparatus further includes a preheating unit for preheating the etching composition, and after preheating the etching composition in the preheating unit, the etching composition is supplied to the etching tank through the first raw material supply unit may be doing

The semiconductor device etching apparatus may further include a drain part for draining a portion of the etching composition used for etching the semiconductor device.

The semiconductor device etching apparatus may further include an overflow part for overflowing a portion of the etching composition used for etching the semiconductor device.

In the etching method of a semiconductor device and the etching apparatus of a semiconductor device according to the present invention, in etching a silicon nitride film and a silicon oxide film with high-temperature phosphoric acid, the silicon nitride film is selectively etched with respect to the silicon oxide film by controlling the high-temperature phosphoric acid while increasing the silicon concentration Problems such as abnormal growth of silicon do not occur.

1 to 3 are cross-sectional views illustrating a device isolation process of a flash memory device using a method of manufacturing a semiconductor device according to an embodiment of the present invention.
4 to 9 are cross-sectional views illustrating a process of forming a pipe channel of a flash memory device using a method of manufacturing a semiconductor device according to an embodiment of the present invention.
10 and 11 are cross-sectional views illustrating a diode formation process in a phase change memory using a method of manufacturing a semiconductor device according to an embodiment of the present invention.
12 is a schematic diagram schematically illustrating an etching apparatus for a semiconductor device according to another exemplary embodiment of the present invention.
13 is a graph showing nuclear magnetic resonance (NMR) data of silane inorganic acid salts prepared in Examples of the present invention.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, terms such as 'comprise' or 'have' are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, and one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

In the present specification, an alkyl group having 1 to 10 carbon atoms represents a straight-chain or branched acyclic saturated hydrocarbon having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms is one or more ether groups, and 1 to 10 carbon atoms. Represents a straight-chain or branched acyclic hydrocarbon having carbon atoms.

The method of etching a semiconductor device according to an embodiment of the present invention comprises the steps of supplying an etching composition to an etching bath and then heating, adding a silicon additive to the etching composition, etching the semiconductor device in the etching bath; And supplementing the etching composition with water to control the temperature.

First, the etching composition is supplied to an etching bath and then heated.

The supply of the etching composition is according to a wet etching method well known in the art, for example, in the case of an immersion method, the inside of the etching bath is filled with the etching composition, or in the case of a spraying method, in the etching bath. The composition may be sprayed.

In the heating of the etching composition, the etching composition may be heated to a temperature of 150 to 200°C. If the heating temperature is less than 150 ℃, the etching rate of the silicon nitride film may be too low to be etched, and if it exceeds 200 ℃, there may be problems such as equipment corrosion due to high temperature.

At this time, when the inside of the etching bath is filled with the etching composition, the etching composition may be heated after filling the etching bath with the etching composition, but in the case of the spraying method, after heating the etching composition The etching composition may be sprayed.

The etching composition may be used as long as it can etch semiconductor devices, and is not particularly limited in the present invention.

However, the etching composition may preferably include an inorganic acid in order to selectively etch the silicon nitride layer with respect to the silicon oxide layer. The inorganic acid may be any one selected from the group consisting of sulfuric acid, fuming sulfuric acid, nitric acid, phosphoric acid, phosphoric anhydride, pyrophosphoric acid, polyphosphoric acid, and mixtures thereof, preferably sulfuric acid, nitric acid, and phosphoric acid.

More preferably, in order to obtain an etch selectivity of the nitride layer to the oxide layer, the inorganic acid may be phosphoric acid. The phosphoric acid may serve to promote etching by providing hydrogen ions in the etching composition. When the phosphoric acid is used as the inorganic acid, the etching composition may further include sulfuric acid as an additive. The sulfuric acid may increase the boiling point of the etching composition including the phosphoric acid as the inorganic acid, thereby helping to etch the nitride layer.

The content of the inorganic acid may be 70 to 99 wt%, preferably 70 to 90 wt%, more preferably 75 to 85 wt%, based on the total weight of the etching composition. When the inorganic acid is included in less than 70% by weight, the nitride film may not be easily removed and there is a risk of generating particles.

The inorganic acid may be an aqueous inorganic acid solution, and the inorganic acid aqueous solution may contain 70 to 99% by weight, preferably 75 to 85% by weight of the inorganic acid, based on the total weight of the inorganic acid aqueous solution, and the remaining amount of water. If the concentration of the inorganic acid in the aqueous solution of the inorganic acid is less than 70% by weight, the boiling point is low, the etching rate of the silicon nitride film may be lowered, it may take a long time to increase the temperature, and when it exceeds 90% by weight, the high boiling point Therefore, the silicon nitride layer and the oxide layer may be etched at a high rate at the same time, and the etching rate may be lowered due to the low water content.

The etching composition may include a solvent in an amount excluding the above-described inorganic acid. The solvent may be specifically water or deionized water.

Meanwhile, the etching composition may further include 0.01 to 20 wt% of an ammonium-based compound based on the total amount of the etching composition. When the etching composition further includes the ammonium-based compound, the etching rate and selectivity do not change even when the etching composition is used for a long period of time, and the etching rate is maintained constant.

When the ammonium-based compound is added in an amount of less than 0.01 wt%, the effect of maintaining the selectivity is reduced when used for a long period of time, and when it is added in an amount of more than 20 wt%, the etching rate of the nitride film and the silicon oxide film is changed, so that the selectivity can be changed. have.

The ammonium-based compound may be any one or a mixture of two or more selected from aqueous ammonia, ammonium chloride, ammonium acetic acid, ammonium phosphate, ammonium peroxydisulfate, ammonium sulfate, and ammonium hydrofluoric acid salt. In addition, the ammonium-based compound is not limited to the above compound, and includes all compounds having an ammonium ion. For example, the ammonium-based compound may be used together with NH ₄ and HCl.

The etching composition may further include 0.01 to 1% by weight of a fluorine-based compound based on the total amount of the etching composition. When the fluorine-based compound is added in an amount of less than 0.01% by weight, the etching rate of the nitride film may be reduced, so it may not be easy to remove the nitride film. If it exceeds 1% by weight, the etching rate of the nitride film is greatly improved, but the oxide film is also etched. have.

The fluorine-based compound may be any one or a mixture of two or more selected from hydrogen fluoride, ammonium fluoride, and ammonium hydrogen fluoride. More preferably, the use of ammonium hydrogen fluoride is good because the selectivity is maintained during long-term use.

Meanwhile, the etching composition may further include any additives commonly used in the art to improve etching performance. As additives, surfactants, sequestering agents, corrosion inhibitors, and the like can be used.

Next, a silicone additive is added to the heated etching composition.

However, the step of adding the silicon additive may be performed in any step of the etching method of the semiconductor device. That is, the etching composition may be added during heating or added immediately after heating in the heating step, may be added in the step of replenishing water or may be added immediately after replenishing water, which will be described later, and the semiconductor device may be etched. It may be added during or immediately after etching, and the etching composition may be added during drain or overflow, or may be added immediately after drain or overflow.

The silicon additive may be used as long as it can etch a semiconductor device, and is not particularly limited in the present invention. However, the silicon additive may be preferably a silane inorganic acid salt in order to selectively etch the silicon nitride film with respect to the silicon oxide film.

In one embodiment, the silane inorganic acid salt may be prepared by reacting the inorganic acid with the silane compound. Since the silane inorganic acid salt is prepared by reacting the inorganic acid with the silane compound, it may be a mixture of silane inorganic acid salts having various chemical structures rather than a single chemical structure. That is, the etching composition may include a mixture of at least two or more silane inorganic acid salts having different chemical structures. However, the present invention is not limited thereto, and the etching composition may include only one kind of silane inorganic acid salt.

The inorganic acid for preparing the silane inorganic acid salt may be any one selected from the group consisting of sulfuric acid, fuming sulfuric acid, nitric acid, phosphoric acid, phosphoric anhydride, pyrophosphoric acid, polyphosphoric acid, and mixtures thereof, preferably sulfuric acid, nitric acid, phosphoric acid can be

The silane compound may be any one selected from the group consisting of compounds represented by the following Chemical Formulas A1 to A2 and combinations thereof.

[Formula A1]

In Formula A1, R ¹ to R ⁴ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms. and at least one of R ¹ to R ⁴ is a halogen atom or an alkoxy group having 1 to 10 carbon atoms.

The halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably a fluorine group or a chloro group.

Specifically, the compound represented by Formula A1 may be a halo silane compound or an alkoxy silane compound.

The halo silane compound is trimethylchlorosilane, triethylchlorosilane, tripropylchlorosilane, trimethylfluorosilane, triethylfluorosilane, tripropylfluorosilane, dimethyldichlorosilane, diethyldichlorosilane, dipropyldichlorosilane, Dimethyldifluorosilane, diethyldifluorosilane, dipropyldifluorosilane, ethyltrichlorosilane, propyltrichlorosilane, methyltrifluorosilane, ethyltrifluorosilane, propyltrifluorosilane and these It may be any one selected from the group consisting of mixtures.

The alkoxy silane compound is tetramethoxysilane (TMOS), tetrapropoxysilane, methyltrimethoxysilane (MTMOS), methyltriethoxysilane (MTEOS), methyltripropoxysilane, ethyltrimethoxysilane, ethyltri Ethoxysilane, ethyltripropoxysilane, propyltrimethoxysilane (PrTMOS), propyltriethoxysilane (PrTEOS), propyltripropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, Diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dipropyldipropoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane Poxysilane, triethylmethoxysilane, triethylethoxysilane, triethylpropoxysilane, tripropylmethoxysilane, tripropylethoxysilane, tripropylpropoxysilane, 3-chloropropyltrimethoxysilane, 3- Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, [3-(2-aminoethyl)aminopropyl]trimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltri It may be any one selected from the group consisting of methoxysilane, 3-acryloxypropyltrimethoxysilane, and mixtures thereof.

[Formula A2]

In Formula A2, R ⁵ to R ¹⁰ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms. one, and at least one of R ⁵ to R ¹⁰ is a halogen atom or an alkoxy group having 1 to 10 carbon atoms, and n is an integer of 1 to 10.

The halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably a fluorine group or a chloro group.

Specifically, the compound represented by Formula A2 is chlorodimethylsiloxy-chlorodimethylsilane, chlorodiethylsiloxy-chlorodimethylsilane, dichloromethylsiloxy-chlorodimethylsilane, dichloroethylsiloxy-chlorodimethylsilane, trichloro Siloxy-chlorodimethylsilane, fluorodimethylsiloxy-chlorodimethylsilane, difluoromethylsiloxy-chlorodimethylsilane, trifluorosiloxy-chlorodimethylsilane, methoxydimethylsiloxy-chlorodimethylsilane, dimethoxy Dimethylsiloxy-chlorodimethylsilane, trimethoxysiloxy-chlorodimethylsilane, ethoxydimethylsiloxy-chlorodimethylsilane, diethoxymethylsiloxy-chlorodimethylsilane, triethoxysiloxy-chlorodimethylsilane, chlorodimethyl siloxy-dichloromethylsilane, trichlorosiloxy-dichloromethylsilane, chlorodimethylsiloxy-trichlorosilane, dichloromethylsiloxy-trichlorosilane, or trichlorosiloxy-trichlorosilane.

Specifically, silane inorganic acid salts prepared by reacting the inorganic acid with the silane compound are as shown in the following Chemical Formulas. However, the silane inorganic acid salts of the present invention are not limited to the following chemical structure.

[Formula A3-1]

[Formula A3-2]

[Formula A3-3]

[Formula A3-4]

[Formula A3-5]

[Formula A3-6]

[Formula A3-7]

[Formula A4-1]

[Formula A4-2]

[Formula A4-3]

[Formula A4-4]

[Formula A4-5]

[Formula A4-6]

[Formula A4-7]

[Formula A5-1]

[Formula A5-2]

[Formula A5-3]

[Formula A5-4]

[Formula A5-5]

[Formula A5-6]

[Formula A5-7]

In Formulas A3-1 to A3-7, A4-1 to A4-7, and A5-1 to A5-7, R ^1-1 to R ^1-8 are each independently a hydrogen atom, a halogen atom, and 1 to carbon atoms Any one selected from the group consisting of a 10 alkyl group, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms, the halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably fluorine group or chloro group.

In another embodiment, the silane inorganic acid salt may be prepared by reacting polyphosphoric acid with the silane compound represented by Formula A1.

In this case, the silane compound may be represented by the following Chemical Formula B1.

[Formula B1]

In Formula B1, R ¹ is any one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms, and the halogen atom is It may be a fluorine group, a chloro group, a bromine group, or an iodine group, and preferably a fluorine group or a chloro group.

The n ₁ is an integer of 1 to 4, and m ₁ is an integer of 1 to 10.

R ² to R ⁴ are each independently a hydrogen atom. However, optionally any one hydrogen selected from the group consisting of R ² to R ⁴ may be substituted with a substituent represented by the following Chemical Formula B2.

[Formula B2]

In Formula B2, any one of R ⁵ is a linking group with Formula B1, and the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and 6 to carbon atoms. Any one selected from the group consisting of 30 aryl groups. That is, when R ⁵ is 4, one is a linking group with Formula B1, and the other three are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and 6 carbon atoms. to 30 may be any one selected from the group consisting of aryl groups. In addition, when R ⁵ is one, R ⁵ is a linking group with Formula B1.

The n ₂ is an integer of 0 to 3, and m ₂ is an integer of 1 to 10.

In Formula B2, R ² to R ⁴ may be each independently hydrogen or substituted with a substituent represented by Formula B2. That is, the substituent represented by the second formula B2 may be substituted at the positions of R ² to R ⁴ , and the substituents represented by the second formula B2 may be substituted with the third formula B2 at the positions of R ² to R ⁴ . The indicated substituent may be further substituted.

This is because the silane inorganic acid salt is prepared by reacting the polyphosphoric acid with the silane compound. That is, the polyphosphoric acid and the silane compound react to produce a compound represented by Formula B1, and in the compound represented by Formula B1, a hydroxyl group at the R ² to R ⁴ site of the polyphosphoric acid-derived portion The silane compound as a reaction starting material may react again, and the silane compound reacted with the compound represented by Formula B1 and the polyphosphoric acid as a reaction starting material may react again, and this reaction will continue can

The result of the silane inorganic acid salt according to the result of the continuous reaction is exemplified as follows.

In Formula B1, n ₁ is 1, m ₁ is 1, and R ² to R ⁴ are all hydrogen, as shown in Formula B3-1 below. In this case, the definitions of R ^1-1 to R ^1-3 are the same as the definitions of R ¹ above.

[Formula B3-1]

The compound represented by Formula B3-2 is the same as the compound represented by Formula B3-1, except that m ₁ is 2.

[Formula B3-2]

In Formula B1, n ₁ is 2, m ₁ is 1, and R ² to R ⁴ are all hydrogen, as shown in Formula B3-3 below. In this case, the definitions of R ^1-1 to R ^1-2 are the same as the definitions of R ¹ above.

[Formula B3-3]

In Formula B1, n ₁ is 1, m ₁ is 1, R ² and R ³ are hydrogen, and R ⁴ is substituted with a substituent represented by Formula B2. same as 4 In Formula B2, n ₂ is 0, and any one of R ⁵ is a linking group with Formula B1. In this case, the definitions of R ^1-1 to R ^1-6 are the same as the definitions of R ¹ above. The compound represented by the following formula B3-4 is a product produced by reacting the moiety derived from the polyphosphoric acid having a substituent of R ⁴ of the compound represented by the formula B1 and the silane compound as a reaction starting material again.

[Formula B3-4]

In Formula B1, n ₁ is 1, m ₁ is 1, R ³ and R ⁴ are hydrogen, and R ² is substituted with a substituent represented by Formula B2. same as In Formula B2, n ₂ is 1, m ₂ is 1, any one of R ⁵ is a linking group with Formula B1, and R ² to R ⁴ are all hydrogen atoms. In this case, the definitions of R ^1-1 to R ^1-5 are the same as those of R ¹ above. The compound represented by the following formula B3-5 is the silane compound as a starting material of the reaction with the hydroxyl group at the R ⁴ site of the portion derived from the polyphosphoric acid in the compound represented by the formula B1 reacts again, and continuously It is a product produced by reacting the silane compound reacted with the compound represented by B1 and the polyphosphoric acid as a reaction starting material again.

[Formula B3-5]

The compounds represented by Formulas B3-6 and B3-7 are represented by Formula B3-5, except that the substituents represented by Formula B2 are changed to R ³ and R ⁴ positions instead of R ² positions of Formula B1. It is the same case as the compound that becomes

[Formula B3-6]

[Formula B3-7]

In Formula B1, n ₁ is 1, m ₁ is 1, R ² and R ³ are hydrogen, R ⁴ is substituted with a substituent represented by Formula B2, and the substituent represented by Formula B2 is A case in which the substituent represented by the second formula (B2) is substituted at the R ⁴ position is shown in the following formula (B3-8). In Formula B2, n ₂ is 1, m ₂ is 1, any one of R ⁵ is a linking group with Formula B1, and R ² to R ³ are hydrogen atoms. In this case, the definitions of R ^1-1 to R ^1-7 are the same as the definitions of R ¹ above. The compound represented by the following formula B3-8 is the silane compound as a starting material for reaction with the hydroxyl group of the part derived from the polyphosphoric acid at the right end of the compound represented by the formula B3-7 again, and continuously the formula It is a product produced by reacting the silane compound reacted with the compound represented by B3-7 and the polyphosphoric acid as a starting material for the reaction again.

[Formula B3-8]

The present invention is not limited to the compounds exemplified in B3-1 to B3-8, and various modifications are possible with reference to the compounds.

Meanwhile, the silane compound capable of reacting with the polyphosphoric acid to prepare the silane inorganic acid salt represented by Formula B1 may be a compound represented by Formula A1. The compound represented by Formula A1 is the same as described above.

The polyphosphoric acid may be pyrophosphoric acid including two phosphoric acid atoms or polyphosphoric acid including three or more phosphoric acid atoms.

The method for preparing the silane inorganic acid salt by reacting the polyphosphoric acid with the silane compound includes using the polyphosphoric acid instead of the inorganic acid in the method for preparing the silane inorganic acid salt by reacting the inorganic acid with the silane compound and the same

In another embodiment, the silane inorganic acid salt is prepared by reacting any one inorganic acid selected from the group consisting of phosphoric acid, phosphoric anhydride, pyrophosphoric acid, polyphosphoric acid, and mixtures thereof with the siloxane compound represented by Formula A2. silane inorganic acid salt.

In this case, the silane inorganic acid salt may be represented by the following Chemical Formula C1.

[Formula C1]

In Formula C1, R ¹ to R ² are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms. and the halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably a fluorine group or a chloro group.

Wherein n ₁ is an integer of 0 to 3, n ₂ is an integer of 0 to 2, m ₁ is an integer of 0 or 1, and n ₁ +n ₂ +m ₁ ≥1 is satisfied. That is, Formula C1 includes at least one atomic group derived from an inorganic acid such as phosphoric acid.

The l ₁ is an integer of 1 to 10, and O ₁ to O ₃ are each independently an integer of 0 to 10.

The R ³ to R ¹¹ are each independently hydrogen. However, optionally any one hydrogen selected from the group consisting of R ³ to R ¹¹ may be substituted with a substituent represented by the following Chemical Formula C2.

[Formula C2]

In Formula C2, any one of R ¹² and R ¹³ is a linking group with Formula C1, and the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. Any one selected from the group consisting of a group and an aryl group having 6 to 30 carbon atoms. That is, when R ¹² is two and R ¹³ is one, one of them is a linking group with Chemical Formula C1, and the other two are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and a carbon number. It may be any one selected from the group consisting of an alkoxy group having 1 to 10 and an aryl group having 6 to 30 carbon atoms. In addition, when R ¹² is 1 and R ¹³ is 0, it is a linking group with Formula C1.

Wherein n ₃ is an integer of 0 to 3, n ₄ is an integer of 0 to 2, and m ₁ is an integer of 0 or 1. The l ₁ is an integer of 1 to 10, and O ₁ to O ₃ are each independently an integer of 0 to 10.

Each of R ³ to R ¹¹ may be independently hydrogen, or may be substituted with a substituent represented by the second formula C2. That is, the substituent represented by the second formula C2 may be substituted at the positions of R ³ to R ¹¹ , and the third formula C2 at the positions of R ³ to R ¹¹ of the second substituent represented by the formula C2 A substituent represented by may be further substituted.

This is because the silane inorganic acid salt is prepared by reacting the inorganic acid with the siloxane compound. That is, the inorganic acid and the siloxane compound are reacted to produce a compound represented by Formula C1, and in the compound represented by Formula C1, the reaction starts with the hydroxyl group at the R ³ to R ¹¹ sites of the inorganic acid-derived portion. The siloxane compound as a material may react again, and the siloxane compound reacted with the compound represented by Formula C1 may react again with the inorganic acid as a starting material for the reaction, and this reaction may continue.

The result of the silane inorganic acid salt according to the result of the continuous reaction is exemplified as follows.

In Formula C1, the n ₁ is 1, the n ₂ is 0, the m ₁ is 0, the l ₁ is 1, the O ₁ to O ₃ are 0, and the R ³ to R ¹¹ are all The case of hydrogen is exemplified by the following Chemical Formula C1-1. In this case, the definitions of R ^1-1 to R ^1-2 are the same as those of R ¹ , and the definitions of R ^2-1 to R ^2-2 are the same as the definitions of R ² .

[Formula C1-1]

The compound represented by Formula C1-2 is the same as the compound represented by Formula C1-2, except that n ₂ is 1.

[Formula C1-2]

The compound represented by the following Chemical Formula C1-3 is the same as the compound represented by the Chemical Formula C1-1, except when O ₂ and O ₃ are 1.

[Formula C1-3]

The compound represented by Formula C1-4 is the same as the compound represented by Formula C1-2, except when l ₁ is 2.

[Formula C1-4]

In Formula C1, n ₁ and n ₂ are 2, m ₁ is 0, 1 ₁ is 1, O ₁ to O ₃ are 0, and R ³ to R ¹¹ are all hydrogen. As an example, it is represented by the following Chemical Formula C1-5.

[Formula C1-5]

In Formula C1, the n ₁ is 1, the n ₂ is 1, the m ₁ is 0, the l ₁ is 1, the O ₁ to O ₃ are 0, and the R ⁶ , R ⁹ and R ¹¹ is hydrogen and R ⁸ is substituted with the substituent represented by Formula C2 as shown in Formula C1-6 below. In Formula C2, n ₃ and n ₄ are 0, m ₁ is 0, 1 ₁ is 1, and any one of R ¹² is a linking group with Formula C1. In this case, the definitions of R ^1-1 to R ^1-7 are the same as the definitions of R ¹ , and the definitions of R ^2-1 are the same as the definitions of R ² . The compound represented by the following Chemical Formula C1-6 is a product obtained by reacting the siloxane compound as a starting material for the reaction with the hydroxyl group at the R ⁸ site of the portion derived from the inorganic acid in the compound represented by the Chemical Formula C1.

[Formula C1-6]

In Formula C1, n ₁ is 1, n ₂ is 1, m ₁ is 0, 1 ₁ is 1, O ₁ to O ₃ are 0, and R ⁶ , R ⁹ and R ¹¹ is hydrogen and R ⁸ is substituted with a substituent represented by Formula C2 as shown in Formula C1-7 below. In Formula C2, n ₃ and n ₄ are 1, m ₁ is 0, O ₂ and O ₃ are 0, and any one of R ¹² is a linking group to Formula C1, and R ⁶ , R ⁸ , R ⁹ and R ¹¹ are hydrogen. In this case, the definitions of R ^1-1 to R ^1-3 , R ^2-1 , R ^2-2 , R ^3-1 and R ^3-2 are the same as the definitions of R ¹ , R ² and R ³ , respectively. In the compound represented by Formula C1-7, the siloxane compound as a reaction starting material reacts again with the hydroxyl group at the R ⁸ site of the portion derived from the inorganic acid in the compound represented by Formula C1, and continues to the Formula C1 It is a product produced by reacting the siloxane compound reacted with the compound represented by and the inorganic acid as a reaction starting material again.

[Formula C1-7]

The compound represented by Formula C1-8 is the same as the compound represented by Formula C1-7, except that the substituent represented by Formula C2 is connected to Formula C1 through the R ^1-3 position of Formula C1-7. is the case

[Formula C1-8]

In Formula C1, n ₁ is 1, n ₂ is 1, m ₁ is 0, 1 ₁ is 1, O ₁ to O ₃ are 0, and R ³ , R ⁶ , R ⁹ and R ¹¹ are hydrogen, R ⁸ is substituted with a substituent represented by the first Formula C2, and R ⁸ of the first substituent represented by Formula C2 is substituted with a second substituent represented by Formula C2 When exemplifying the case, it is shown in the following Chemical Formula C1-9. In Formula C2 of the first formula, n ₃ and n ₄ are 1, m ₁ is 0, 1 ₁ is 1, O ₂ and O ₃ are 0, and any one of R ¹² is It is a linking group with Chemical Formula C1, R ⁶ , R ⁹ , and R ¹¹ are hydrogen, and R ⁸ is a substituent represented by the second Chemical Formula C2. In the second formula C2, n ₃ and n ₄ are 1, m ₁ is 0, 1 ₁ is 1, O ₂ and O ₃ are 0, and any one of R ¹² is A linking group with the first formula C2, wherein R ⁶ , R ⁸ , R ⁹ and R ¹¹ are hydrogen. In this case, the definitions of R ^1-1 to R ^1-4 , R ^2-1 to R ^2-3 and R ^3-1 to R ^3-3 are the same as the definitions of R ¹ , R ² and R ³ , respectively.

The compound represented by the following formula C1-9 is obtained by reacting the siloxane compound as a reaction starting material with the portion derived from the inorganic acid at the right end of the compound represented by the formula C1-7, and continuously forming the compound represented by the formula C1-7 It is a product produced by reacting the siloxane compound reacted with the indicated compound and the inorganic acid as a reaction starting material again.

[Formula C1-9]

The compound represented by Formula C1-10 is represented by Formula C1-9, except that the second substituent represented by Formula C2 is connected to Formula C1 by the R ^1-4 position of Formula C1-9 It is the same case as the compound.

[Formula C1-10]

The present invention is not limited to the compounds exemplified in 1-1 to 1-10, and various modifications are possible with reference to the compounds.

In another embodiment, the silane compound may be a silane inorganic acid salt prepared by reacting any one inorganic acid selected from the group consisting of sulfuric acid, fuming sulfuric acid, and mixtures thereof with the siloxane compound represented by Formula A2.

In this case, the silane inorganic acid salt may be represented by the following Chemical Formula C3.

[Formula C3]

In Formula C3, R ²¹ to R ²² are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms. and the halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably a fluorine group or a chloro group.

Wherein n ₁ is an integer of 0 to 3, n ₂ is an integer of 0 to 2, m ₁ is an integer of 0 or 1, and n ₁ +n ₂ +m ₁ ≥1 is satisfied. That is, Formula C3 includes at least one atomic group derived from an inorganic acid such as sulfuric acid.

The l ₁ is an integer of 1 to 10.

wherein R ²³ to R ²⁵ are each independently hydrogen. However, optionally any one hydrogen selected from the group consisting of R ²³ to R ²⁵ may be substituted with a substituent represented by the following formula C4.

[Formula C4]

In Formula C4, any one of R ²⁶ and R ²⁷ is a linking group with Formula C3, and the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. Any one selected from the group consisting of a group and an aryl group having 6 to 30 carbon atoms. That is, when R ²⁶ is two and R ²⁷ is one, one of them is a linking group with Chemical Formula C3, and the other two are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and a carbon number. It may be any one selected from the group consisting of an alkoxy group having 1 to 10 and an aryl group having 6 to 30 carbon atoms. In addition, when R ²⁶ is one and R ²⁷ is 0, it is a linking group with Formula C3.

Wherein n ₃ is an integer of 0 to 3, n ₄ is an integer of 0 to 2, m ₁ is an integer of 0 or 1, and l ₁ is an integer of 1 to 10.

Each of R ²³ to R ²⁵ may be independently hydrogen, or a substituent represented by the second formula C4 may be substituted. That is, the substituent represented by the second formula C4 may be substituted in the positions of R ²³ to R ²⁵ , and the third formula C4 in the positions of R ²³ to R ²⁵ in the second substituent represented by the formula C4 A substituent represented by may be further substituted.

When exemplified similarly to the case of Chemical Formulas C1-1 to 1-10, the resultant of the silane inorganic acid salt according to the result of the continuous reaction is shown in the following Chemical Formulas C3-1 to C3-9. In this case, in the following formulas C3-1 to C3-9, the definitions of R ^11-1 to R ^11-7 , R ^12-1 to R ^12-3 and R ^13-1 to R ^13-3 are respectively R ¹¹ , R ¹² and R ¹³ .

[Formula C3-1]

[Formula C3-2]

[Formula C3-3]

[Formula C3-4]

[Formula C3-5]

[Formula C3-6]

[Formula C3-7]

[Formula C3-8]

[Formula C3-9]

The present invention is not limited to the compounds exemplified in 3-1 to 3-9, and various modifications are possible with reference to the compounds.

In another embodiment, the silane inorganic acid salt may be a silane inorganic acid salt prepared by reacting an inorganic acid including nitric acid with a siloxane compound represented by Formula A2.

In this case, the silane inorganic acid salt may be represented by the following Chemical Formula C5.

[Formula C5]

In Formula C5, R ³¹ to R ³² are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms. and the halogen atom may be a fluorine group, a chloro group, a bromine group, or an iodine group, preferably a fluorine group or a chloro group.

Wherein n ₁ is an integer of 0 to 3, n ₂ is an integer of 0 to 2, m ₁ is an integer of 0 or 1, and n ₁ +n ₂ +m ₁ ≥1 is satisfied. That is, Formula C5 includes at least one atomic group derived from the inorganic acid including nitric acid.

The l ₁ is an integer of 1 to 10.

The R ³³ to R ³⁵ are each independently hydrogen. However, optionally any one hydrogen selected from the group consisting of R ³³ to R ³⁵ may be substituted with a substituent represented by the following formula C6.

[Formula C6]

In Formula C6, any one of R ³⁶ and R ³⁷ is a linking group with Formula C5, and the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. and any one selected from the group consisting of an aryl group having 6 to 30 carbon atoms. That is, when R ³⁶ is two and R ³⁷ is one, one of them is a linking group with Formula C5, and the other two are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and 1 carbon number. to 10 may be any one selected from the group consisting of an alkoxy group and an aryl group having 6 to 30 carbon atoms. In addition, when R ³⁶ is one and R ³⁷ is 0, R ³⁶ is a linking group with Formula C5.

Wherein n ₃ is an integer of 0 to 3, n ₄ is an integer of 0 to 2, m ₁ is an integer of 0 or 1, and l ₁ is an integer of 1 to 10.

Each of R ³³ to R ³⁵ may independently be hydrogen, or a substituent represented by the second formula C6 may be substituted. That is, the substituent represented by the second formula C6 may be substituted in the positions of R ³³ to R ³⁵ , and the third formula C6 in the positions of R ³³ to R ³⁵ of the second substituent represented by the formula C6. A substituent represented by may be further substituted.

If the result of the silane inorganic acid salt according to the result of the continuous reaction is exemplified similarly to the case of Chemical Formulas C1-1 to C1-10, the following Chemical Formulas C5-1 to C5-9 are shown. In this case, in the following formulas C5-1 to C5-9, the definitions of R ^21-1 to R ^21-7 , R ^22-1 to R ^22-3 and R ^23-1 to R ^23-3 are respectively R ²¹ , R ²² and R ²³ .

[Formula C5-1]

[Formula C5-2]

[Formula C5-3]

[Formula C5-4]

[Formula C5-5]

[Formula C5-6]

[Formula C5-7]

[Formula C5-8]

[Formula C5-9]

The present invention is not limited to the compounds exemplified by Chemical Formulas C5-1 to C5-9, and various modifications are possible with reference to the compounds.

Meanwhile, the siloxane compound capable of reacting with the inorganic acid to prepare the silane inorganic acid salt represented by Formula C1 may be a compound represented by Formula A2 below. The compound represented by Formula A2 is the same as described above.

The method for preparing the silane inorganic acid salt by reacting the inorganic acid with the siloxane compound includes using the siloxane compound instead of the silane compound in the method for preparing the silane inorganic acid salt by reacting the inorganic acid with the silane compound and the same

Meanwhile, the silicone additive may be added such that the content of the silicone additive is 0.001 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the etching composition. When the content of the silicone additive is less than 0.001 parts by weight, it may be difficult to implement a selectivity ratio due to a small content ratio of the silicone additive, and when it exceeds 10 parts by weight, the silicone additive may precipitate or abnormal growth of silicon may occur.

Next, the semiconductor device is etched in the etching bath.

The etching process is characterized in that the nitride film is etched, and in particular, the nitride film is selectively etched with respect to the oxide film.

The nitride film may include a silicon nitride film, for example, a SiN film, an SiON film, or the like.

In addition, the oxide film is a silicon oxide film, for example, a SOD (Spin On Dielectric) film, HDP (High Density Plasma) film, thermal oxide film, BPSG (Borophosphate Silicate Glass) film, PSG (Phospho Silicate Glass) film, 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 Film, MTO (Medium Temperature Oxide) film, USG (Undoped Silicate Glass) film, SOG (Spin On Glass) film, APL (Advanced Planarization Layer) film, ALD (Atomic Layer Deposition) film, PE-Oxide (Plasma Enhanced oxide) film , O3-TEOS (O3-Tetra Ethyl Ortho Silicate) film, and may be at least one film selected from the group consisting of combinations thereof.

The etching process may be performed by a wet etching method well known in the art, for example, an immersion method, a spraying method, and the like.

During the etching process, the process temperature may be in the range of 50 to 300 °C, preferably 100 to 200 °C, and the appropriate temperature may be changed as necessary in consideration of other processes and other factors.

As described above, according to the method of manufacturing a semiconductor device including an etching process performed using the etching composition, when the nitride layer and the oxide layer are alternately stacked or mixed, selective etching of the nitride layer is possible. In addition, it is possible to prevent the generation of particles, which has been a problem in the conventional etching process, thereby securing the stability and reliability of the process.

Accordingly, this method can be efficiently applied to various processes requiring selective etching of a nitride film with respect to an oxide film in a semiconductor device manufacturing process.

1 to 3 are cross-sectional views illustrating a device isolation process of a flash memory device using the semiconductor device etching method.

Referring to FIG. 1 , a tunnel oxide layer 21 , a polysilicon layer 22 , a buffer oxide layer 23 , and a pad nitride layer 24 are sequentially formed on a substrate 20 .

Subsequently, the pad nitride layer 24 , the buffer oxide layer 23 , the polysilicon layer 22 , and the tunnel oxide layer 21 are selectively etched through a photo and etching process to expose the device isolation region of the substrate 20 . .

Subsequently, the exposed substrate 20 is selectively etched using the pad nitride layer 24 as a mask to form a trench 25 having a predetermined depth from the surface.

Referring to FIG. 2 , an oxide layer 26 is formed on the entire surface of the substrate 20 by using a chemical vapor deposition (CVD) method until the trench 25 is gap-filled.

Next, a chemical mechanical polishing (CMP) process is performed on the oxide film 26 using the pad nitride film 24 as a polishing stop film.

Then, a cleaning process is performed using dry etching.

Referring to FIG. 3 , after the pad nitride layer 24 is selectively removed by the etching method of the semiconductor device, the buffer oxide layer 23 is removed by a cleaning process. As a result, the device isolation layer 26A is formed in the field region.

As shown in FIG. 3 , in the present invention, by using a high selectivity etching method with a high etching selectivity of the nitride layer to the oxide layer, the etching of the oxide layer gap-filled in the STI pattern is minimized while the nitride layer is completely and selectively selected for a sufficient time. can be removed Accordingly, it is possible to easily control the effective oxide film height EFH, and it is possible to prevent deterioration of electrical characteristics and generation of particles due to damage to the oxide film or etching, thereby improving device characteristics.

Although the above embodiment has been described with respect to the flash memory device, the method of etching the semiconductor device is, of course, applicable to the device isolation process of the DRAM device.

4 to 9 are cross-sectional views illustrating a channel forming process of a flash memory device using the semiconductor device etching method.

Referring to FIG. 4 , a pipe gate electrode layer 31 in which a nitride layer 32 for forming a pipe channel is buried is formed on a substrate 30 . The first and second conductive layers 31A and 31B constituting the pipe gate electrode layer 31 may include, for example, polysilicon doped with impurities.

More specifically, a first conductive film 31A is formed on the substrate 30 , a nitride film is deposited on the first conductive film 31A, and the nitride film is patterned to form a nitride film 32 for pipe channel formation. After that, a second conductive film 31B is formed on the first conductive film 31A exposed by the nitride film 32 . The first and second conductive films 31A and 31B form the pipe gate electrode film 31 .

Next, a first interlayer insulating layer 33 and a first gate electrode layer 34 are alternately stacked on the process resultant to form a plurality of memory cells stacked in a vertical direction. Hereinafter, for convenience of description, a structure in which the first interlayer insulating layer 33 and the first gate electrode layer 34 are alternately stacked will be referred to as a cell gate structure CGS.

Here, the first interlayer insulating layer 33 is for separation between the plurality of layers of memory cells, and may include, for example, an oxide layer, and the first gate electrode layer 34 is, for example, poly doped with impurities. It may contain silicone. In the present embodiment, the six-layered first gate electrode layer 34 is illustrated, but the present invention is not limited thereto.

Subsequently, the cell gate structure CGS is selectively etched to form a pair of first and second holes H1 and H2 exposing the nitride layer 32 . The first and second holes H1 and H2 are spaces for forming channels of the memory cell.

Referring to FIG. 5 , a nitride layer 35 buried in the first and second holes H1 and H2 is formed. The nitride film 35 may be damaged when the first gate electrode film 34 is exposed by the first and second holes H1 and H2 in a trench formation process (refer to FIG. 6 ) to be described later. is to prevent

Referring to FIG. 6 , a cell between a pair of first and second holes H1 and H2 so that the plurality of layers of the first gate electrode layer 34 is separated for each of the first and second holes H1 and H2 . A trench S is formed by selectively etching the gate structure CGS.

Referring to FIG. 7 , a sacrificial layer 36 buried in the trench S is formed.

Referring to FIG. 8 , a second interlayer insulating layer 37 , a second gate electrode layer 38 , and a second interlayer insulating layer 37 are sequentially formed on the process resultant to form a selection transistor. Hereinafter, for convenience of description, the stacked structure of the second interlayer insulating layer 37 , the second gate electrode layer 38 , and the second interlayer insulating layer 37 is referred to as a selection gate structure SGS.

The second interlayer insulating layer 37 may include, for example, an oxide layer, and the second gate electrode layer 38 may include, for example, polysilicon doped with impurities.

Next, the selection gate structure SGS is selectively etched to form third and fourth holes H3 and H4 exposing the nitride layer 35 buried in the pair of first and second holes H1 and H2. do. The third and fourth holes H3 and H4 are regions in which channels of the selection transistor are to be formed.

Referring to FIG. 9 , the nitride film 35 exposed by the third and fourth holes H3 and H4 and the nitride film 32 thereunder are selectively removed by a wet etching process using the etching composition according to the present invention. do.

As a result of this process, a pair of cell channel holes H5 and H6 in which a channel layer of a memory cell is to be formed, and a pipe channel hole H7 disposed under the cell channel holes H5 and H6 to interconnect them are formed. In this case, by using the etching composition having a high selectivity according to the present invention, the nitride film is completely and selectively removed for a sufficient time without loss of the oxide film, so that the pipe channel can be accurately formed without loss of the profile. In addition, it is possible to prevent the generation of particles, which has been a problem in the prior art, it is possible to secure the stability and reliability of the process.

Thereafter, a subsequent process, for example, a floating gate forming process and a control gate forming process, is performed to form a flash memory device.

10 and 11 are cross-sectional views illustrating a diode formation process in a phase change memory device using the etching method of the semiconductor device.

Referring to FIG. 10 , an insulating structure having an opening exposing the conductive region 41 is provided on the substrate 40 . The conductive region 41 may be, for example, an n ⁺ impurity region.

Next, a polysilicon film 42 is formed to partially fill the opening, and then impurities are ion-implanted to form a diode.

Next, a titanium silicide layer 43 is formed on the polysilicon layer 42 . The titanium silicide film 43 may be formed by heat treatment to react with the polysilicon film 42 after forming the titanium film.

Subsequently, a titanium nitride film 44 and a nitride film 45 are sequentially formed on the titanium silicide film 43 .

Next, an oxide layer 46 is formed in an isolated space between the diodes formed by performing a dry etching process using a hard mask, and then a CMP process is performed to form a primary structure of each separated lower electrode.

Referring to FIG. 11 , a wet etching process using the etching composition according to the present invention is performed on the process result to selectively remove the upper nitride layer 45 . As described above, by using the etching composition having a high selectivity according to the present invention when removing the nitride layer, the nitride layer can be completely and selectively removed for a sufficient time without loss of the oxide layer. In addition, deterioration of electrical properties and generation of particles due to damage to the film quality of the oxide film or etching of the oxide film may be prevented, thereby improving device characteristics.

Next, titanium is deposited in the space where the nitride layer 45 is removed to form a lower electrode.

In addition to the above-described process, the etching method of the semiconductor device is particularly effective for a process requiring selective removal of the nitride film, for example, a process requiring selective etching of the nitride film when the nitride film and the oxide film are alternately stacked or mixed. Applicable.

On the other hand, the etching method of the semiconductor device includes the step of adjusting the temperature by supplementing the etching composition with water.

The etching composition containing the silicon additive can be used in a high-temperature etching process. When the etching composition includes an inorganic acid, the inorganic acid heated to a high temperature in the high-temperature etching process is easy to etch the silicon nitride / oxide film, The process temperature is about 100 to 170 °C.

More specifically, when the inorganic acid is phosphoric acid, 85% by weight of phosphoric acid boils at about 157 ° C. In order to use the etching composition in the high temperature etching process, it is to supplement the water evaporated above the boiling point. need. Accordingly, the water may be replenished by the amount evaporated during the preparation of the etching composition.

In addition, by replenishing the water, it is possible to control the temperature of the etching composition to be below the boiling point of the inorganic acid.

In this case, it is preferable to use deionized water (DIW) as the water.

The etching rate of the silicon nitride film through the high-temperature etching process is about 50 to 70 Å/min, the etching rate of the silicon thermal oxide film is about 2 to 5 Å/min, and the etching rate of the silicon oxide film depends on the content of the silicon additive. It is also possible to adjust the etching rate close to 0 Å/min.

Meanwhile, the step of replenishing the water may be performed in any step of the etching method of the semiconductor device. That is, in the step of heating the etching composition, water may be replenished during heating or may be replenished immediately after heating, water may be replenished together with the silicon additive or may be replenished immediately after addition of the silicon additive, and the semiconductor device may be etched. Water can be added during the process, or it can be added right after etching. In addition, the etching composition, which will be described later, may be replenished with water during drain or overflow, or may be replenished immediately after drain or overflow.

In addition, the method of etching the semiconductor device may further include selectively preheating the etching composition.

It may be preferable to preheat the etching composition to shorten the process time. The preheating of the etching composition may include preheating the etching composition to 100 to 140°C, preferably 120 to 130°C. When the preheating temperature is less than 100° C., the temperature stabilization time may be lengthened due to a rapid temperature drop when it is put into the etching bath, and when it exceeds 140° C., it may be difficult to control the etching rate due to the content of evaporated water.

On the other hand, the etching method of the semiconductor device selectively drains a part of the etching composition used in the step of etching the semiconductor device, and then repeats the etching method of the semiconductor device, or etches the semiconductor device After a portion of the etching composition used in the step of overflow (overflow), the etching method of the semiconductor device may be repeated.

That is, after a part of the etching composition used in the step of etching the semiconductor device is drained or overflowed, the etching composition is supplied to the etching bath, and the process of etching the semiconductor device while supplementing the silicon additive and water is repeated. can do.

When a portion of the used etching composition is drained or overflowed, and a new etching composition is partially added to repeatedly manufacture the semiconductor device, the number of times the etching composition is used can be significantly increased.

In this case, the drain or overflow of the etching composition may be drained or overflowed in an amount of 10 to 30 wt% based on the total weight of the etching composition. If the drain or overflow content is less than 10% by weight, the content of silicon ions to be etched may accumulate and cause abnormal growth and particles, and if it exceeds 30% by weight, a new etching composition is excessively input due to excessive replacement Therefore, the temperature stabilization time may be prolonged.

In addition, after the drain or overflow of the etching composition, the added etching composition may be added in an amount of 10 to 30 wt % based on the total weight of the etching composition before the drain or overflow. Preferably, the amount of the drain or overflowed etching composition may be added. If the content of the added etching composition is less than 70 wt%, the time for temperature stabilization and process stabilization of the etching composition may be long, and if it exceeds 90 wt%, it may be difficult to control the water content.

A semiconductor device etching apparatus according to another embodiment of the present invention includes an etching bath for etching a semiconductor device using an etching composition, a first raw material supply unit for supplying the etching composition to the etching bath, and a silicon additive in the etching bath It includes a second raw material supply unit for supplying the etchant, a water replenishment unit for replenishing water in the etching tank, and a heating unit for heating the etching composition.

12 is a schematic diagram schematically illustrating an etching apparatus for a semiconductor device according to another exemplary embodiment of the present invention. Hereinafter, the etching apparatus 100 of the semiconductor device will be described with reference to FIG. 12 .

The semiconductor device etching apparatus 100 includes the etching bath 10 . The etching bath 10 etches the semiconductor device by immersing the semiconductor device in the etching composition or spraying the etching composition on the semiconductor device.

To this end, the etchant 10 includes a first raw material supply unit 11 for supplying the etching composition, a second raw material supply unit 12 for supplying the silicon additive, and heating the etching composition. It includes a heating unit (13). In addition, the etching bath 10 may optionally further include a spraying unit (not shown) for spraying the etching composition to the semiconductor device.

In addition, since water may decrease when the etching composition is continuously heated, in order to supplement the etching composition with a certain amount of water, the etching apparatus 100 of the semiconductor device supplements the etching composition with water. It may further include a water replenishment unit 20 for.

In addition, the etching composition is preferably supplied to the etching bath 10 after preheating for shortening the process stabilization time and stabilizing the etching composition, the etching apparatus 100 of the semiconductor device is the etching composition. It may further include a preheating unit 30 for preheating the . The preheating unit 30 may supply the etching composition to the etching bath 10 through the first raw material supply unit 11 after preheating the etching composition.

In addition, the etching apparatus 100 for the semiconductor device includes a drain 40 for draining a portion of the etching composition used for etching the semiconductor device, and the etching composition used for etching the semiconductor device. It may further include an overflow part 50 for overflowing a portion of the , or both.

After draining or overflowing a portion of the etching composition used in the step of etching the semiconductor device through the drain portion 40 and the overflow portion 50 , the etching composition is applied to the etching bath 10 . In the case of repeating the process of etching the semiconductor device while partially supplying the silicon additive and replenishing the water, the number of times of use of the etching composition can be significantly increased.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[Example A: Preparation of silane inorganic acid salt]

A silane inorganic acid salt was prepared under the conditions shown in Table 1 below, and an etching composition was prepared by mixing the prepared silane inorganic acid salt and phosphoric acid in the respective weight ratios indicated with respect to the total weight of the composition. As the inorganic acid, an 85% aqueous solution was used.

Example mineral acid Silane Mineral Acid Phosphoric acid content
(weight%) Silane mineral acid content
(weight%) silane compound mineral acid Weight ratio of inorganic acid and silane compound Reaction temperature (℃) Example A1 85 One In Formula A1, R ¹ is methyl, and R ² to R ⁴ are a chloro group. phosphoric acid 20:100 70 Example A2 83 One In Formula A1, R ¹ To R ⁴ Are an ethoxy group phosphoric acid 5:100 90 Example A3 84 One In Formula A1, R ¹ is methyl, and R ² to R ⁴ are a chloro group. sulfuric acid 10:100 70 Example A4 83 One In Formula A1, R ¹ To R ⁴ Are an ethoxy group sulfuric acid 20:100 40 Example A5 83 One In Formula A1, R ¹ is methyl, and R ² to R ⁴ are a chloro group. nitric acid 10:100 50 Example A6 85 3 In Formula A1, R ¹ To R ⁴ Are an ethoxy group nitric acid 10:100 40

13 is a graph showing nuclear magnetic resonance (NMR) data of the silane inorganic acid salt prepared in Example A1. Referring to FIG. 13, in Formula A1, R ¹ is methyl, and R ² to R ⁴ are chloro groups and phosphoric acid, which is a second inorganic acid, reacted to prepare silane inorganic acid salts. In addition, in FIG. 13, the peak at 11.1364 ppm to 11.4053 ppm is not a narrow peak (sharp peak) seen in a single material, but a broad peak (broad peak) is observed. It can be seen that the silane inorganic acid salts prepared by reacting an inorganic acid with a silane compound are not a single chemical structure, but a mixture of silane inorganic acid salts having various chemical structures.

[Experimental Example A1: Measurement of Selectivity of the Prepared Etching Composition]

The nitride film and oxide film were etched at a process temperature of 157° C. using the etching composition prepared above, and the nitride film and oxide film were etched using an ellipsometer (NANO VIEW, SEMG-1000), which is a thin film thickness measuring device. The speed and selectivity were measured and shown in Table 2. The etching rate is a value calculated by dividing the difference between the film thickness before the etching treatment and the film thickness after the etching treatment of each film by the etching time (minutes) after each film is etched for 300 seconds. It represents the ratio of speed.

Example Process temperature (℃) Nitride etch rate
(Å/min) Oxide etching rate (Å/min) selection fee ThO _x ¹⁾ LP-TEOS ²⁾ BPSG ³⁾ LP-TEOS BPSG Example A1 157 58.24 0.30 0.21 0.76 277.33 76.63 Example A2 157 58.73 0.26 0.18 1.08 326.28 54.38 Example A3 157 58.21 0.29 0.22 0.93 264.59 62.59 Example A4 157 58.27 0.70 0.11 0.89 529.73 65.47 Example A5 157 58.91 0.30 0.122 0.86 482.87 68.50 Example A6 157 58.81 0.25 0.07 1.14 840.14 51.59

1) ThO: thermal oxide

2) LP-TEOS: Low Pressure Tetra Ethyl Ortho Silicate Membrane

3) BPSG: Borophosphate Silicate Glass membrane

[ comparative example A1 to A3: for etching Preparation of composition]

In Comparative Example A1, the etching rate and selectivity were measured as in the above example at a process temperature of 157° C. using phosphoric acid. In Comparative Example A2, the etching rate and selectivity were measured at a process temperature of 130° C., which is a low temperature process possible in the process in which hydrofluoric acid was added, using a mixture in which 0.05% of hydrofluoric acid was added to phosphoric acid, and in Comparative Example A3, Comparative Example A2 Etching rate and selectivity were measured at the same process temperature of 157° C. as in Example using the same mixture as described above. The phosphoric acid used in Comparative Examples A1 to A3 was an 85% aqueous solution. The evaluation results of Comparative Examples A1 to A3 are shown in Table 3 below.

etching composition Process temperature (℃) Nitride etch rate
(Å/min) Oxide etching rate (Å/min) selection fee ThOx LP-TEOS BPSG LP-TEOS BPSG Comparative Example A1 phosphoric acid 157 61.32 1.1 13.19 9.85 4.64 6.23 Comparative Example A2 Phosphoric acid + hydrofluoric acid (0.05 wt%) 130 15.44 0 2.3 1.03 6.71 14.99 Comparative Example A3 Phosphoric acid + hydrofluoric acid (0.05 wt%) 157 76.12 5.67 32.14 20.48 2.36 3.71

Comparing Tables 2 and 3, it can be seen that the etching selectivity of the nitride film to the oxide film is significantly higher in the etching compositions of Examples compared to Comparative Examples A1 to A3. Therefore, by using the etching composition of the high selectivity according to the present invention, it is possible to easily control the EEH by controlling the etching rate of the oxide film, and it is possible to prevent damage to the film quality of the oxide film. In addition, it is possible to prevent the generation of particles, which has been a problem in the prior art, it is possible to secure the stability and reliability of the process.

[Experimental Example A1-1: E/R (etching rate) measurement after process progress]

After preheating an etching composition containing 85 wt% phosphoric acid and the remaining content of D.I. to 140 °C, it was supplied to an etching bath and heated to 165 °C. The semiconductor device was immersed in the etching composition, and etching was performed for 300 seconds. At this time, when the semiconductor device is etched, 0.01 parts by weight of the silicon inorganic acid salt prepared in Example A1 is supplied based on 100 parts by weight of the etching composition, and the etching proceeds while supplying deionized water (DIW) corresponding to the amount of evaporated water. did.

After the above process, E/R was measured, and the results are shown in Table 4 below.

Example Process temperature (℃) Nitride etch rate
(Å/min) Oxide etching rate (Å/min) selection fee ThO _x ¹⁾ LP-TEOS ²⁾ BPSG ³⁾ LP-TEOS BPSG Example A1 165 57.86 0.05 0.02 0.25 2893.00 231.44 Example A2 165 58.15 0.02 0.01 0.30 5815.00 193.83 Example A3 165 57.56 0.04 0.02 0.16 2878.00 359.75 Example A4 165 56.92 0.10 0.03 0.18 1897.33 316.22 Example A5 165 58.01 0.05 0.01 0.20 5801.00 290.05 Example A6 165 57.85 0.02 0.01 0.32 5785.00 180.78

1) ThO: thermal oxide

2) LP-TEOS: Low Pressure Tetra Ethyl Ortho Silicate Membrane

3) BPSG: Borophosphate Silicate Glass membrane

Referring to Table 4, it can be seen that the selectivity can be adjusted through the addition of the inorganic silicon salt.

However, it can be seen that a low etching rate of the silicon oxide film is obtained with a high selectivity greater than a predetermined selectivity as the process progresses. That is, it can be seen that this is a condition in which abnormal growth or particles may be generated as the process progresses.

[Experimental Example A1-2: E/R (etching rate) measurement after process progress]

The process proceeds under the same conditions as in Experimental Example A1-1, but after draining 10 wt% or 30 wt% of the etching composition used, respectively, 10 wt% or 30 wt% of the new etching composition E/R was measured under the same conditions as in Experimental Example A1-1, except that the amount was supplemented, and the results are shown in Table 5 below.

Example after drain
replenishment amount Process temperature (℃) Nitride etch rate
(Å/min) Oxide etching rate (Å/min) selection fee ThO _x ¹⁾ LP-TEOS ²⁾ BPSG ³⁾ LP-TEOS BPSG Example A1 10% 165 58.01 0.21 0.15 0.53 386.73 109.45 Example A2 165 58.12 0.20 0.10 0.83 581.20 70.02 Example A3 165 57.97 0.19 0.13 0.71 445.92 81.65 Example A4 165 57.12 0.58 0.08 0.70 714.00 81.60 Example A5 165 58.26 0.18 0.10 0.63 582.60 92.48 Example A6 165 58.10 0.12 0.05 0.93 1162.00 62.47 Example A1 30% 165 58.25 0.32 0.20 0.75 291.25 77.67 Example A2 165 58.70 0.25 0.20 1.10 293.50 53.36 Example A3 165 58.30 0.30 0.22 1.00 265.00 58.30 Example A4 165 58.20 0.68 0.13 0.91 447.69 63.96 Example A5 165 58.85 0.30 0.13 0.86 452.69 68.43 Example A6 165 58.80 0.25 0.07 1.10 840.00 53.45

Referring to Table 5, after the etching is carried out, by draining 10 wt% or 30 wt% of the etching composition and then replenishing the new etching composition, particles and abnormal growth due to the increase of silicon ions in the etching composition as the process proceeds It turns out that this problem can be solved. Through this, the use time of the etching composition can be increased, and the abnormal growth and level of particles can be controlled.

The present invention is not limited by the above-described embodiments and the accompanying drawings, and it is common in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. It will be clear to those who have knowledge.

100: semiconductor device etching device
10: Etch bath
11: first raw material supply unit 12: second raw material supply unit
13: heating unit
20: water replenishment part
30: preheating unit
40: drain part
50: overflow part

Claims (18)

An etching bath for etching a semiconductor device using an etching composition, a first raw material supply unit for supplying the etching composition to the etching bath, a second raw material supply unit for supplying a silicon additive to the etching bath, water is replenished in the etching bath In the etching method of a semiconductor device using a semiconductor device etching apparatus comprising a water replenishment unit for, and a heating unit for heating the etching composition,
After supplying the etching composition to the etching bath by the first raw material supply unit, heating the etching composition by the heating unit;
adding a silicone additive to the etching composition by the second raw material supply unit;
etching the semiconductor device in the etching bath; and
Regulating the temperature by supplementing the etching composition with water by the water replenishment unit
A semiconductor device etching method comprising a. According to claim 1,
In the step of heating the etching composition, the etching method of the semiconductor device is to heat the etching composition to 150 to 200 ℃. According to claim 1,
In the step of adding the silicon additive, the amount of the silicon additive is 0.001 to 10 parts by weight based on 100 parts by weight of the etching composition. According to claim 1,
The method of etching a semiconductor device, wherein the water is deionized water (DIW). According to claim 1,
The amount of water evaporated in any one step selected from the group consisting of heating the etching composition, adding a silicon additive to the etching composition, etching the semiconductor device, and combinations thereof. An etching method of a semiconductor device that supplements. According to claim 1,
The method of etching the semiconductor device further comprises the step of preheating the etching composition. 7. The method of claim 6,
The preheating of the etching composition may include preheating the etching composition to 100 to 140°C. According to claim 1,
The method of etching the semiconductor device is to drain a part of the etching composition used in the step of etching the semiconductor device, and then repeat the etching method of the semiconductor device. According to claim 1,
The method of etching the semiconductor device is to overflow a part of the etching composition used in the step of etching the semiconductor device, and then repeat the etching method of the semiconductor device. 10. The method according to claim 8 or 9,
The method of etching a semiconductor device, wherein the drain or overflow of the etching composition is 10 to 30 wt% of the drain or overflow based on the total weight of the etching composition. According to claim 1,
The etching composition is an etching method of a semiconductor device comprising an inorganic acid. 12. The method of claim 11,
The inorganic acid is an aqueous inorganic acid solution,
The method for etching a semiconductor device, wherein the inorganic acid aqueous solution includes 70 to 99% by weight of the inorganic acid and the remaining amount of water based on the total weight of the inorganic acid aqueous solution. 12. The method of claim 11,
The inorganic acid is any one selected from the group consisting of sulfuric acid, fuming sulfuric acid, nitric acid, phosphoric acid, phosphoric anhydride, and mixtures thereof. According to claim 1,
The silicon additive is a silane inorganic acid salt method of etching a semiconductor device. An etching bath for etching semiconductor devices using an etching composition;
a first raw material supply unit for supplying the etching composition to the etching tank;
a second raw material supply unit for supplying a silicon additive to the etching bath;
a water replenishing unit for replenishing water in the etchant; and
A heating unit for heating the etching composition
A semiconductor device etching apparatus comprising a. 16. The method of claim 15,
The semiconductor device etching apparatus further includes a preheating unit for preheating the etching composition,
After preheating the etching composition in the preheating unit, the etching apparatus for a semiconductor device to supply the etching composition to the etching tank through the first raw material supply unit. 16. The method of claim 15,
The semiconductor device etching apparatus further comprises a drain portion for draining a portion of the etching composition used for etching the semiconductor device. 16. The method of claim 15,
The semiconductor device etching apparatus further comprises an overflow portion for overflowing a portion of the etching composition used for etching the semiconductor device.

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