Etching composition for silicon-containing layer and method of forming pattern using the same

Abstract

An etching composition for a silicon-containing film and a method for forming a pattern using the same are provided, comprising: a fluorine-based compound; an oxidizing agent; an additive comprising at least one of a compound represented by the following chemical formula 1 and an oligomer formed by the ring-opening polymerization thereof; and water. [Chemical Formula 1]

Description

Technology Field

[0001] The present invention relates to an etching composition for a silicon-containing film and a method for forming a pattern using the same. More specifically, it relates to an etching composition for a silicon-containing film used in semiconductor-related processes and a method for forming a pattern using the same. Background Technology

[0003] Recently, in semiconductor device technology, research is continuing to achieve high integration while reducing the critical dimension (CD) in DRAM, NAND flash memory, logic devices, etc. In this process, silicon-based films (e.g., polysilicon) are being utilized for various purposes such as gate electrodes, capacitor electrodes, conductive contacts, and wiring.

[0004] There is a demand for a process that selectively etches only silicon in silicon-containing metal films while maintaining corrosion resistance to the silicon oxide in structures where silicon oxide and silicon films coexist. For a high-reliability process, it is necessary to achieve a fast and uniform etching rate for the silicon to be removed, while simultaneously securing a high etch selectivity to protect the silicon oxide.

[0005] From this perspective, there is a need to develop an etching composition capable of selectively etching silicon without affecting the silicon oxide film.

[0006] Korean Patent Publication No. 10-2023-0102276 discloses a silicon selective etching solution composition comprising a fluorine compound; nitric acid; acetic acid; phosphoric acid; and a cationic oligomer with a molecular weight Mw of 100 to 100,000, but it does not have a corrosion protection effect on silicon oxide films and has insufficient surface properties. Korean Patent Publication No. 10-2017-0001366 discloses an aqueous cleaning agent composition comprising an inorganic fluorine compound, an aminosilane compound, a polar organic solvent, and water, but silicon etching ability is very low or impossible. Prior art literature

[0008] Republic of Korea Published Patent No. 10-2008-0017576 Republic of Korea Published Patent No. 10-2023-0006034 The problem to be solved

[0009] One objective of the present invention is to provide an etching composition for a silicon-containing film having improved etching efficiency and etching uniformity.

[0010] One objective of the present invention is to provide a pattern formation method using the etching composition for the silicon-containing film. means of solving the problem

[0012] 1. An etching composition for a silicon-containing film comprising: a fluorine-based compound; an oxidizing agent; an additive comprising at least one of a compound represented by the following chemical formula 1 and an oligomer formed by the ring-opening polymerization thereof; and water:

[0013] [Chemical Formula 1]

[0014]

[0015] (In the above Chemical Formula 1, R1 and R2 are each independently -H, -OH, -F, -Cl, -Br, -I, a C1-C7 alkyl group, a C1-C7 alkoxy group, or a C1-C7 alkylthio group, and

[0016] The above R1 and R2 may each be independently substituted or unsubstituted with at least one substituent selected from the group consisting of -OH, -F, -Cl, -Br, -I, -COOH, -CHO, C1-C3 alkyl groups, and C1-C3 alkoxy groups).

[0017] 2. An etching composition for a silicon-containing film according to 1 above, wherein the average molecular weight of the oligomer is 3000 g / mol or less.

[0018] 3. An etching composition for a silicon-containing film according to 2 above, wherein the average molecular weight of the oligomer is 1000 g / mol or less.

[0019] 4. An etching composition for a silicon-containing film according to 1 above, wherein R1 and R2 in Chemical Formula 1 are each independently -H, a C1-C5 alkyl group, a C1-C5 alkoxy group, or a C1-C5 alkylthio group.

[0020] 5. An etching composition for a silicon-containing film according to 1 above, wherein R1 and R2 in Chemical Formula 1 are each independently -H, a C1-C4 alkyl group, or a C1-C4 alkoxy group.

[0021] 6. An etching composition for a silicon-containing film according to 1 above, wherein the additive comprises at least one of glycolide, lactide, 3,6-diethyl-1,4-dioxane-2,5-dione, 3,6-dipropyl-1,4-dioxane-2,5-dione, 3,6-diisopropyl-1,4-dioxane-2,5-dione, 3,6-diisobutyl-1,4-dioxane-2,5-dione, and oligomers formed by ring-opening polymerization thereof.

[0022] 7. An etching composition for a silicon-containing film according to 1 above, wherein the content of the additive is 0.1% by weight to 10% by weight.

[0023] 8. An etching composition for a silicon-containing film according to 1 above, wherein the fluorine-based compound comprises at least one of a hydrofluoric acid-based compound and an ionic fluoride compound.

[0024] 9. An etching composition for a silicon-containing film according to 1, comprising 0.1% to 20% by weight of the fluorine-based compound and 0.1% to 20% by weight of the oxidizing agent.

[0025] 10. A method for forming a pattern, comprising: a step of forming a silicon-containing film on a substrate; a step of partially forming a silicon protective film on the silicon-containing film; and a step of etching silicon with an etching composition for a silicon-containing film according to claim 1.

[0026] 11. A pattern forming method according to 10, wherein the silicon protective film is used as an etching mask.

[0027] 12. A pattern forming method according to 10, wherein the step of etching the silicon-containing film comprises etching the silicon-containing film to form a gate pattern. Effects of the invention

[0029] The etching composition for a silicon-containing film according to an embodiment of the present invention includes a fluorine-based compound and a compound of Formula 1 together, which can selectively etch silicon while suppressing the etching of a silicon oxide film. Through this, the etching speed and uniformity of silicon can be effectively improved.

[0030] The pattern forming method according to an embodiment of the present invention can improve the precision and uniformity of the pattern by securing high selectivity and uniformity of silicon through the use of such an etching composition for a silicon-containing film. Brief explanation of the drawing

[0032] FIGS. 1 to 7 are schematic cross-sectional views illustrating a pattern forming method according to exemplary embodiments. Specific details for implementing the invention

[0033] With reference to the drawings below, exemplary embodiments of the present disclosure are described in detail so that those skilled in the art can easily practice the present invention. However, this is merely illustrative and the present invention is not limited to the exemplary embodiments described.

[0035] Etching composition for silicon-containing films

[0036] An etching composition for a silicon-containing film according to embodiments of the present disclosure comprises: a fluorine-based compound; an oxidizing agent; an additive comprising at least one of a compound represented by the following chemical formula 1 and an oligomer formed by ring-opening polymerization thereof; and water.

[0037] [Chemical Formula 1]

[0038]

[0039] In the above formula 1, R1 to R4 are each independently -H, -OH, -F, -Cl, -Br, -I, a C1-C7 alkyl group, a C1-C7 alkoxy group, or a C1-C7 alkylthio group, and R1 to R4 may each be independently substituted or unsubstituted with at least one substituent selected from the group consisting of -OH, -F, -Cl, -Br, -I, -COOH, -CHO, a C1-C3 alkyl group, and a C1-C3 alkoxy group. The alkyl group, the alkoxy group, and the alkylthio group may each independently be, for example, a straight-chain or branched-chain group.

[0040] Accordingly, the etching composition for the silicon-containing film achieves a corrosion protection effect on the silicon oxide film and can selectively etch silicon, thereby enabling rapid and uniform etching of silicon and leaving no residue on the surface to be etched.

[0041] The above-described etching composition for a silicon-containing film offers the advantage of improving the etching selectivity of silicon by, for example, reducing the etching rate for a silicon oxide film and increasing the etching rate for silicon. For example, if the etching mask is a silicon oxide film, the etching selectivity of silicon can be further increased.

[0042] The compound of Chemical Formula 1 described above can undergo a hydrolysis reaction within the etching composition, for example, a ring-opening polymerization reaction. The compound of Chemical Formula 1 may be included in the etching composition in the form of an oligomer, which is a polymer produced by the ring-opening polymerization.

[0043] The compound of Chemical Formula 1 above can exhibit hydrophilic properties, and thus exhibits strong interactions with hydrophilic surfaces such as silicon oxide films, but exhibits relatively weak interactions with hydrophobic surfaces such as silicon-containing films, e.g., crystalline silicon films.

[0044] In this case, the compound of Chemical Formula 1 and / or the oligomer may be located close to or attached to the silicon oxide film, thereby protecting the surface of the silicon oxide film and reducing or suppressing etching.

[0045] Conversely, since the compound of Formula 1 and / or the oligomer are not located close to the silicon-containing film, etching can proceed relatively faster.

[0046] Accordingly, the compound of Chemical Formula 1 and / or the oligomer can achieve an improved etching selectivity ratio, and such selective etching performance can be usefully utilized in semiconductor processes, for example, for precisely patterning silicon oxide films and crystalline silicon.

[0047] The above oligomer may include repeating units represented by, for example, Chemical Formula 2 below.

[0048] [Chemical Formula 2]

[0049]

[0050] In the above chemical formula 2, the definitions for R1 to R4 are the same as those described above in chemical formula 1, and n can be an integer from 1 to 25, for example.

[0051] In some embodiments, two or more compounds represented by the above chemical formula 1 may be included.

[0052] For example, in the case where at least one of R1 to R4 as a compound represented by the above chemical formula 1 comprises a first compound and a second compound that are different from each other, it may comprise at least one of a first oligomer comprising a first repeating unit represented by the above chemical formula 2 derived from the first compound; a second oligomer comprising a second repeating unit represented by the above chemical formula 2 derived from the second compound; and a third oligomer comprising both the first repeating unit and the second repeating unit.

[0053] For example, the two ends of the above oligomer may be -OH and -COOH, respectively, and accordingly, can be represented by the following chemical formula 3.

[0054] [Chemical Formula 3]

[0055]

[0056] The definitions of R1 to R4 and n in the above Chemical Formula 3 are the same as those described above in the above Chemical Formula 2.

[0057] In some embodiments, the average molecular weight of the oligomer may be 2000 g / mol or less, 1500 g / mol or less, or 1000 g / mol or less. Accordingly, the oligomer may be present in close proximity to the surface of the silicon oxide film, thereby improving corrosion resistance of the silicon oxide film. If the compound represented by Chemical Formula 1 undergoes an excessive polymerization reaction and is included in the etching composition as a polymer, it may also be present around the silicon film, thereby reducing the etching rate of the silicon.

[0058] In some embodiments, R1 to R4 in Formula 1 may each independently be -H, a C1-C5 alkyl group, a C1-C5 alkoxy group, or a C1-C5 alkylthio group.

[0059] In some embodiments, R1 to R4 in Formula 1 may each independently be -H, a C1-C4 alkyl group, or a C1-C4 alkoxy group.

[0060] Accordingly, the compound of Chemical Formula 1 and / or the oligomer may be located closer to the surface of the silicon oxide film, thereby improving the corrosion resistance of the silicon oxide film.

[0061] In some embodiments, at least one of R1 and R2 in Formula 1 is H, and at least one of R3 and R4 may be H.

[0062] In some embodiments, either R1 or R2 of Formula 1 may be H and the remainder may be a C1-C4 alkyl group, and either R3 or R4 may be H and the remainder may be a C1-C4 alkyl group.

[0063] In some embodiments, the additive may include an oligomer formed by ring-opening polymerization of a compound represented by Formula 1.

[0064] In some embodiments, the additive may include a compound represented by Formula 1 and an oligomer formed by the ring-opening polymerization of the compound represented by Formula 1.

[0065] For example, the above additive may include at least one of glycolide, lactide, 3,6-diethyl-1,4-dioxane-2,5-dione, 3,6-dipropyl-1,4-dioxane-2,5-dione, 3,6-diisopropyl-1,4-dioxane-2,5-dione, 3,6-dibutyl-1,4-dioxane-2,5-dione, 3,6-diisobutyl-1,4-dioxane-2,5-dione and oligomers formed by ring-opening polymerization thereof.

[0066] In some embodiments, the content of the additive may be 0.1% by weight to 10% by weight. If the content of the additive is too low, the anti-corrosion effect on the silicon oxide film may not be sufficient, and if it is too high, the etching rate of the silicon-containing film may be relatively reduced.

[0067] In some embodiments, the fluorine-based compound may include at least one of a hydrofluoric acid-based compound and an ionic fluoride compound. For example, for uniform etching of a substrate, a fluorine-based compound capable of isotropic etching may be used as an etching species (etching agent). The hydrofluoric acid-based compound may include one or more hydrofluoric acid, borofluoric acid, bifluoride, etc.

[0068] The above ionic fluoride compound may include a cation and a fluoride anion. The cation included in the above ionic fluoride compound may be an organic cation or an inorganic cation.

[0069] For example, the above organic cation is NH4 + , selected from the group consisting of primary ammonium ions, secondary ammonium ions, tertiary ammonium ions, and quaternary ammonium ions, and said inorganic cation is H + It can be selected from the group consisting of alkali metal ions and alkaline earth metal ions.

[0070] The above primary ammonium ion is NH4 + One of the four -Hs bonded to the N atom may be substituted with an alkyl group having 1 to 10 carbon atoms, the secondary ammonium ion may be substituted with two of the alkyl groups, the tertiary ammonium ion may be substituted with three of the alkyl groups, and the quaternary ammonium ion may be entirely substituted with the alkyl groups.

[0071] For example, the fluorine-based compound may include ammonium fluoride, dimethylammonium fluoride, diethylammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride, tetrahexylammonium fluoride and / or tetraoctylammonium fluoride.

[0072] In some embodiments, the fluorine compound may include at least one selected from the group consisting of ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, and tetrabutylammonium fluoride.

[0073] The above alkali metal ions are, for example, Li + , Na + , K + , Rb + and Cs + It can be selected from among, and the alkaline earth metal ion is, for example, Mg 2+ , and Ca 2+ It can be selected from among them.

[0074] For example, the above fluorinated compounds may include hydrogen fluoride (HF), lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), rubidium fluoride (RbF), cesium fluoride (CsF), magnesium fluoride (MgF2) and / or calcium fluoride (CaF2). These may be used alone or in combination of two or more.

[0075] In some embodiments, the fluorine compound may include at least one selected from the group consisting of hydrogen fluoride (HF), lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), rubidium fluoride (RbF) and cesium fluoride (CsF).

[0076] In some embodiments, the fluorine-based compound may be included in an amount of 0.1% to 20% by weight, for example, 0.1% to 10% by weight or 0.1% to 5% by weight.

[0077] If too little fluorine-based compound is included, the etching rate of silicon is not sufficiently secured, and conversely, if too much is included, the etching rate becomes inconsistent due to the influence of cations, and as a result, the uniformity of the roughness of the etched surface may be relatively reduced.

[0078] The above oxidizing agent can be used as an auxiliary etching agent or an etching promoter in a silicon etching solution composition. For example, the above oxidizing agent can oxidize the surface of a silicon-containing film, thereby further enhancing the etching rate and etching efficiency by fluoride ions.

[0079] In some embodiments, the oxidizing agent may include hydrogen peroxide (H2O2), potassium periodate, nitric acid, nitrate, nitrite, nitrite, periodic acid, periodate, perchloric acid or perchlorate, etc. These may be used alone or in combination of two or more.

[0080] In some embodiments, the oxidizing agent may include hydrogen peroxide (H2O2) and / or potassium periodate. By using a peroxide-based oxidizing agent or an iodine-based oxidizing agent, operational stability is improved, and subsequent processes such as reaction byproduct treatment and cleaning treatment can be simplified. In addition, peroxide-based oxidizing agents or iodine-based oxidizing agents can facilitate the etching process in an alkaline environment, thereby contributing to increased surface treatment efficiency.

[0081] In some embodiments, the oxidizing agent may be included in an amount of 0.1% to 20% by weight, and for example, 1.0% to 10% by weight.

[0082] If too little of the above oxidizing agent is included, the etching rate becomes too slow and non-uniform etching may occur, and if too much is included, an oxide layer accumulates on the silicon surface, which may actually lower the etching selectivity.

[0083] By including an oxidizing agent within the aforementioned range, it is possible to oxidize the wafer surface to form Si-OH without accumulating an oxide layer. Accordingly, dangling bonds are formed on the silicon surface, enabling relatively faster etching of the silicon film compared to a completely oxidized silicon oxide film. Consequently, the etching selectivity of crystalline silicon relative to the silicon oxide film can be increased.

[0084] In some embodiments, the etching composition for the silicon-containing film may further include additives such as an etching promoter, a corrosion inhibitor, and a pH adjuster.

[0085] The above etching composition for silicon-containing films may include an excess or residual amount of water. As used herein, the term “residual amount” may refer to a variable amount that changes depending on the addition of components or formulations. For example, it may refer to the remaining amount excluding the aforementioned fluorine-based compounds, oxidizing agents, and azetidine-based compounds, and / or other additives.

[0086] In some embodiments, the water may be deionized water for semiconductor processes, and preferably, deionized water with a resistivity of 18 MΩ / cm or higher may be used.

[0087] In some embodiments, the etching composition for the silicon-containing film may further include additives such as an etching promoter, a corrosion inhibitor, and a pH adjuster.

[0088] In some embodiments, the pH of the etching composition for the silicon-containing film may be, for example, 11 or higher or 12 or higher. Within the above pH range, silicon can be selectively etched while preventing or suppressing damage to other insulating structures, etc.

[0089] The silicon film may include, for example, a single-crystal silicon film, a polysilicon film (Poly-Si), and / or a Si (100) film.

[0090] The above silicon film may be, for example, a silicon film formed according to the following CVD process.

[0091] Silicon precursors: SH4, dichlorosilane, disilane, etc.

[0092] Deposition temperature: 350℃ to 800℃

[0093] Deposition pressure: 0.1 torr to 760 torr

[0094] Gas environment: Inert gas (N2, Ar, etc.)

[0096] Pattern Formation Method

[0097] A silicon etching method using the silicon-containing film etching composition according to the embodiments of the present disclosure may be carried out by methods commonly known in the art. For example, methods such as immersion, spraying, or immersion and spraying may be used in a batch-type etching apparatus or a single-type etching apparatus. However, these conditions are not strictly applicable and may be selected by those skilled in the art as easy or suitable conditions.

[0098] FIGS. 1 to 7 are schematic cross-sectional views for illustrating a pattern forming method according to embodiments of the present disclosure.

[0099] However, the etching composition for a silicon-containing film according to the embodiments of the present disclosure is not limited to use in the processes of FIGS. 1 to 7, and can be utilized in various structures or pattern formation processes such as wiring, contacts, and gates as long as they fall within the spirit and technical scope of the present invention.

[0100] FIGS. 1 to 3 are schematic cross-sectional views for illustrating a method of manufacturing a semiconductor device according to exemplary embodiments.

[0101] Referring to FIG. 1, an insulating film (110) can be formed on the substrate (100), and a silicon-containing film (120) can be formed on the insulating film (110).

[0102] The substrate (100) may include semiconductor materials such as single-crystal silicon and single-crystal germanium, and may include polysilicon.

[0103] The insulating film (110) may be formed to include insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, etc. For example, the insulating film (110) may be formed through a chemical vapor deposition (CVD) process, a sputtering process, a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, etc.

[0104] The silicon-containing film (120) may include single-crystal silicon, polysilicon, or amorphous silicon.

[0105] Referring to FIG. 2, a silicon protective film (130) can be formed on the silicon-containing film (120). The silicon protective film (130) may be formed to include silicon oxide and / or silicon nitride. For example, the silicon protective film (130) may be formed through a CVD process, a sputtering process, a PVD process, an ALD process, etc.

[0106] A mask pattern (132) can be formed by partially etching the silicon protective film (130). For example, a portion of the silicon protective film (130) may be partially etched until a portion of the upper surface of the silicon-containing film (120) is exposed.

[0107] In the above pattern formation method, a gate pattern can be formed by etching a silicon-containing film using the etching composition for a silicon-containing film described above.

[0108] As shown in FIG. 3, the silicon-containing film (120) can be partially removed using the etching composition for the silicon-containing film. Accordingly, a gate pattern (122) can be formed from the silicon-containing film (120).

[0109] As described above, the etching composition for the silicon-containing film comprises a fluorine-based compound and a compound of Formula 1 and / or an oligomer thereof, thereby improving the etching selectivity for silicon and achieving a corrosion protection effect on the silicon oxide film.

[0110] FIGS. 4 to 7 are schematic cross-sectional views illustrating a pattern forming method according to exemplary embodiments. Specifically, FIGS. 4 to 7 are schematic cross-sectional views illustrating a shallow trench isolation (STI) forming method according to exemplary embodiments.

[0111] Referring to FIG. 4, a silicon protective film (210) can be formed on a substrate (200).

[0112] The above substrate (200) may be a silicon substrate including single-crystal silicon, polysilicon, or amorphous silicon.

[0113] The silicon protective film (210) may be formed to include silicon oxide, silicon nitride, etc. For example, the silicon protective film (210) may include silicon oxide. In this case, the silicon protective film may be formed through a chemical vapor deposition (CVD) process, a sputtering process, a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, etc., so as to cover the upper surface of the substrate (200).

[0114] In the above pattern forming method, the silicon protective film (210) can be used as an etching mask.

[0115] Referring to FIG. 5, the silicon protective film (210) can be partially etched to form a mask pattern (215). For example, a portion of the silicon protective film (210) can be etched until a portion of the upper surface of the substrate (200) is exposed.

[0116] Referring to FIG. 6, the upper surface of the substrate (200) can be partially etched using the above-described etching composition for a silicon-containing film. Accordingly, a trench (220) can be formed inside the substrate (200).

[0117] As described above, by using the etching composition for the silicon-containing film, etching of the mask pattern (215) can be prevented, and only the upper part of the substrate (200) can be selectively etched. Therefore, for example, in a nano-scale fine etching process, the upper part of the substrate (200) can be removed without etching defects, and a highly reliable etching process can be performed.

[0118] Referring to FIG. 7, an insulating pattern (230) can be formed inside the trench (220).

[0119] The insulating pattern (230) may be formed to include an insulating material including silicon oxide, silicon nitride, silicon oxynitride, or polysiloxane. For example, the insulating material may be formed through a CVD process, a sputtering process, a PVD process, an ALD process, etc., so as to be filled inside the trench (220).

[0121] Hereinafter, experimental examples including specific embodiments and comparative examples are presented to aid in understanding the present invention; however, these are merely illustrative of the invention and do not limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope and spirit of the present invention, and that such variations and modifications fall within the scope of the appended claims.

[0123] Examples and Comparative Examples

[0124] Etching compositions for silicon-containing films according to Examples 1 to 22 were prepared by mixing each component listed in Table 1 below in their respective amounts. Etching compositions according to Comparative Examples 1 to 6 were prepared by mixing each component listed in Table 2 below in their respective amounts. Here, each amount is expressed as weight% based on the total weight of the composition.

[0125] Composition (weight%) Oxidizing agent Fluorine compounds additives water division Content division Content division Content Content Example 1 A-1 0.05 B-3 2.0 C-1 1.5 Remaining amount Example 2 A-1 0.1 B-3 2.0 C-1 1.5 Remaining amount Example 3 A-1 1.0 B-3 2.0 C-1 1.5 Remaining amount Example 4 A-1 10.0 B-3 2.0 C-1 1.5 Remaining amount Example 5 A-1 20.0 B-3 2.0 C-1 1.5 Remaining amount Example 6 A-1 25.0 B-3 2.0 C-1 1.5 Remaining amount Example 7 A-2 8.0 B-3 2.0 C-1 1.5 Remaining amount Example 8 A-3 0.3 B-3 2.0 C-1 1.5 Remaining amount Example 9 A-1 3.0 B-3 0.05 C-1 1.5 Remaining amount Example 10 A-1 3.0 B-3 0.1 C-1 1.5 Remaining amount Example 11 A-1 3.0 B-3 5.0 C-1 1.5 Remaining amount Example 12 A-1 3.0 B-3 20.0 C-1 1.5 Remaining amount Example 13 A-1 3.0 B-3 25.0 C-1 1.5 Remaining amount Example 14 A-1 3.0 B-1 0.3 C-1 1.5 Remaining amount Example 15 A-1 3.0 B-2 1.2 C-1 1.5 Remaining amount Example 16 A-1 3.0 B-3 2.0 C-1 0.05 Remaining amount Example 17 A-1 3.0 B-3 2.0 C-1 0.1 Remaining amount Example 18 A-1 3.0 B-3 2.0 C-1 0.5 Remaining amount Example 19 A-1 3.0 B-3 2.0 C-1 3.0 Remaining amount Example 20 A-1 3.0 B-3 2.0 C-1 10.0 Remaining amount Example 21 A-1 3.0 B-3 2.0 C-1 15.0 Remaining amount Example 22 A-1 3.0 B-3 2.0 C-2 8.0 Remaining amount

[0126] Composition (weight%) Oxidizing agent Fluorine compounds additives water division Content division Content division Content Content Comparative Example 1 A-1 0.0 B-3 2.0 C-1 1.5 Remaining amount Comparative Example 2 A-1 3.0 B-3 0.0 C-1 1.5 Remaining amount Comparative Example 3 A-1 3.0 B-3 2.0 C-1 0.0 Remaining amount Comparative Example 4 A-1 3.0 B-3 2.0 C-3 1.5 Remaining amount Comparative Example 5 A-1 3.0 B-3 2.0 C-4 1.5 Remaining amount Comparative Example 6 A-1 3.0 B-3 2.0 C-5 1.5 Remaining amount

[0128] The components listed in Table 1 and Table 2 above are as follows.

[0129] (A) Oxidizing agent

[0130] A-1 : Hydrogen peroxide

[0131] A-2 : Nitric acid

[0132] A-3 : Sodium hypochlorite

[0134] (B) Fluorine compounds

[0135] B-1: Hydrofluoric Acid

[0136] B-2: Ammonium fluoride

[0137] B-3: Tetrabutylammonium fluoride

[0139] (C) Additives

[0140] C-1 : DL-Lactide

[0141]

[0142] C-2: Glycolide

[0143]

[0144] C-3: Gamma-Butyrolactone

[0145]

[0146] C-4: Glycolic acid

[0147]

[0149] Experimental Example

[0150] The physical properties of the etching compositions according to the above-described examples and comparative examples were evaluated as follows.

[0152] Experimental Example 1: Evaluation of Etching Rate for Silicon Film

[0153] A crystalline Si wafer was cut to a size of 1.5 cm x 1.5 cm to prepare a specimen. The specimen was immersed in room temperature DHF (200:1) for 1 minute to remove the native oxide layer on the surface. The initial thickness of the specimen was measured using an ellipsometer. The specimen was immersed in a water bath containing an etching composition at 60°C and 400 rpm for 1 minute, then removed, washed with water, and dried using air. The final thickness of the dried specimen was measured using an ellipsometer. From this, the amount of thickness reduction per hour (V1) was calculated according to Equation 1 below.

[0154] [Equation 1]

[0155] V1 = (Initial thickness - Late thickness) Å / 1 min

[0157] The evaluation criteria for the etching rate of the above silicon film are as follows.

[0158] <Criteria>

[0159] ◎: Etching rate 40 Å / min or higher and less than 80 Å / min

[0160] ○: Etching rate 20 Å / min or more and less than 40 Å / min, or 80 Å / min or more and less than 120 Å / min

[0161] △: Etching rate 10 Å / min or more and less than 20 Å / min, or 120 Å / min or more and less than 200 Å / min

[0162] Х: Etching rate less than 10 Å / min, or 200 Å / min or more

[0164] The results are shown in Table 3 below.

[0166] Experimental Example 2: Evaluation of Silicon Etching Selectivity

[0167] The silicon etching selectivity ratio was calculated by dividing the etching rate for the silicon film obtained in Experimental Example 1 above by the etching rate for the silicon oxide film.

[0168] [Equation 2]

[0169] Etching selectivity = Etching rate for silicon film / Etching rate for silicon oxide film

[0170] The evaluation criteria are as follows.

[0171] ◎ : Etching ratio 30 or higher

[0172] ○ : Etching ratio 22 or higher ~ less than 30

[0173] △ : Etching ratio greater than 10 ~ less than 22

[0174] Х : Etching ratio 10 or less

[0176] Experimental Example 3: Evaluation of Si Surface Roughness

[0177] In the etching rate evaluation, the surface roughness (Rq) of the etched crystalline silicon thin film was measured using an atomic force microscope (AFM).

[0178] ◎: 0.2nm or less

[0179] ○: Exceeding 0.2nm and 0.5nm or less

[0180] △: Greater than 0.5nm and 1.5nm or less

[0181] X: Exceeds 1.5nm

[0183] Crystalline silicon etching rate Selection ratio Roughness after etching Example 1 △ △ ○ Example 2 △ ○ ○ Example 3 ○ ○ ○ Example 4 ◎ ◎ ◎ Example 5 ○ ○ ○ Example 6 △ ○ △ Example 7 ◎ ◎ ◎ Example 8 ◎ ◎ ◎ Example 9 △ ○ △ Example 10 ○ ○ ○ Example 11 ◎ ○ ◎ Example 12 ○ ○ ○ Example 13 △ △ △ Example 14 ◎ ◎ ○ Example 15 ◎ ◎ ◎ Example 16 ○ △ ○ Example 17 ◎ △ ◎ Example 18 ◎ ○ ◎ Example 19 ○ ◎ ◎ Example 20 ○ ○ ○ Example 21 △ △ ○ Example 22 ◎ ◎ ◎ Comparative Example 1 X X ○ Comparative Example 2 X X ○ Comparative Example 3 ○ X ○ Comparative Example 4 ○ X ○ Comparative Example 5 ○ X ○ Comparative Example 6 X ◎ X

[0185] Referring to Table 3 above, the evaluation results of the etching compositions for silicon-containing films according to the examples showed that the etching rate of the silicon film could be controlled so as not to be too slow or too fast, and the surface roughness was also low. In addition, the etching compositions according to the examples in which the content of the fluorine-based compound was 0.1 wt% to 20 wt%, the examples in which the content of the oxidizing agent was 0.1 wt% to 20 wt%, and the examples in which the content of the additive was 0.5 wt% to 10 wt% exhibited an improved etching selectivity.

[0186] In the evaluation results of the etching compositions according to Comparative Examples 1 to 3, which included only one of a fluorine-based compound, an oxidizing agent, and an azetidine-based compound, the etching selectivity was deteriorated, and in the case of Comparative Examples 1 and 2, the etching rate for the silicon film was further deteriorated.

[0187] In the case of the etching compositions according to Comparative Examples 4 and 5 that did not contain the compound of Chemical Formula 1 or its oligomer, the etching selectivity was degraded, and in the case of Comparative Example 6 that contained a polymer instead of an oligomer, the etching performance for the silicon film was significantly degraded, so it could not be used as an etching composition for the silicon film, and the surface roughness was also degraded.

[0188] Gamma-Butyrolactone used in Comparative Example 4 did not form oligomers through ring-opening reactions within the composition, so the silicon etching selectivity was significantly low, and Glycolic acid used in Comparative Example 5 did not undergo polymerization reactions well between them or the rate was very slow, so the silicon etching selectivity was significantly low, similar to Comparative Example 4. Explanation of the symbols

[0190] 100, 200: Substrate 110: Insulating film 120: Silicon-containing film 122: Gate Pattern 130, 210: Silicone protective film 132, 215: Mask pattern 220: Trench 230: Insulation pattern

Claims

Claim 1 Etching composition for a silicon-containing film comprising: a fluorine-based compound; an oxidizing agent; an additive comprising at least one of a compound represented by the following chemical formula 1 and an oligomer formed by the ring-opening polymerization thereof; and water: [Chemical Formula 1] (In the above Chemical Formula 1, R1 and R2 are each independently -H, -OH, -F, -Cl, -Br, -I, a C1-C7 alkyl group, a C1-C7 alkoxy group, or a C1-C7 alkylthio group, and R1 and R2 may each be independently substituted or unsubstituted with at least one substituent selected from the group consisting of -OH, -F, -Cl, -Br, -I, -COOH, -CHO, a C1-C3 alkyl group, and a C1-C3 alkoxy group). Claim 2 An etching composition for a silicon-containing film according to claim 1, wherein the average molecular weight of the oligomer is 3000 g / mol or less. Claim 3 An etching composition for a silicon-containing film according to claim 2, wherein the average molecular weight of the oligomer is 1000 g / mol or less. Claim 4 An etching composition for a silicon-containing film according to claim 1, wherein R1 and R2 in Chemical Formula 1 are each independently -H, a C1-C5 alkyl group, a C1-C5 alkoxy group, or a C1-C5 alkylthio group. Claim 5 An etching composition for a silicon-containing film according to claim 4, wherein R1 and R2 in Chemical Formula 1 are each independently -H, a C1-C4 alkyl group, or a C1-C4 alkoxy group. Claim 6 An etching composition for a silicon-containing film according to claim 1, wherein the additive comprises at least one of glycolide, lactide, 3,6-diethyl-1,4-dioxane-2,5-dione, 3,6-dipropyl-1,4-dioxane-2,5-dione, 3,6-diisopropyl-1,4-dioxane-2,5-dione, 3,6-diisobutyl-1,4-dioxane-2,5-dione, and oligomers formed by ring-opening polymerization thereof. Claim 7 An etching composition for a silicon-containing film according to claim 1, wherein the content of the additive is 0.1 weight% to 10 weight%. Claim 8 An etching composition for a silicon-containing film according to claim 1, wherein the fluorine-based compound comprises at least one of a hydrofluoric acid-based compound and an ionic fluoride compound. Claim 9 An etching composition for a silicon-containing film according to claim 1, comprising 0.1% to 20% by weight of the fluorine-based compound and 0.1% to 20% by weight of the oxidizing agent. Claim 10 A pattern forming method comprising: a step of forming a silicon-containing film on a substrate; a step of partially forming a silicon protective film on the silicon-containing film; and a step of etching silicon with an etching composition for a silicon-containing film according to claim 1. Claim 11 A pattern forming method according to claim 10, wherein the above silicon protective film is used as an etching mask. Claim 12 A pattern forming method according to claim 10, wherein the step of etching the silicon-containing film comprises etching the silicon-containing film to form a gate pattern.

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