Etching gas containing hexafluoro-2-butyne

Abstract

This disclosure aims to provide a new etching gas containing hexafluoro-2-butyne. [Solution] Etching gas containing hexafluoro-2-butyne.

Description

[Technical Field]

[0001] This disclosure relates to an etching gas containing hexafluoro-2-butyne. [Background technology]

[0002] Patent Document 1 discloses a method for producing a perfluoroalkyne compound, which includes the step of reacting a perfluoroalkadiene compound in the presence of a catalyst to obtain a perfluoroalkyne compound; a composition containing a perfluoroalkyne compound and a perfluorocycloalkene compound; a catalyst used for reacting a perfluoroalkadiene compound to obtain a perfluoroalkyne compound; and a method for producing a catalyst used for reacting a perfluoroalkadiene compound to obtain a perfluoroalkyne compound.

[0003] Patent Document 2 discloses a method for producing a halogenated butene compound, which includes a step of dehydrofluorinating a halogenated butene compound; a method for producing a halogenated butyne compound, which includes a step of dehydrofluorinating a halogenated butene compound; and a method for producing a halogenated butyne compound, which includes a step of producing a halogenated butene compound by dehydrofluorinating a halogenated butene compound, and then producing a halogenated butyne compound by dehydrohalogenating the halogenated butene compound.

[0004] Patent Document 3 discloses a method for producing a perfluorocarbon compound, comprising the step of reacting a halogenated hydrocarbon compound in an organic solvent in the presence of an iodine-containing inorganic material and zinc or a zinc alloy to obtain a perfluorocarbon compound, and a method for producing a perfluoroalkyne compound, comprising the step of reacting a halogenated alkene compound in the presence of zinc or a zinc alloy in at least one nitrogen-containing polar organic solvent selected from the group consisting of N,N-dimethylacetamide, N,N-diisopropylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-3,4,5,6-tetrahydropyrimidinone, hexamethylphosphate triamide, amine compounds, pyridine compounds, and quinoline compounds to obtain a perfluoroalkyne compound. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International public access number WO2020 / 075728A1 [Patent Document 2] International public access number WO2020 / 171011A1 [Patent Document 3] International Publication Number WO2020 / 204146A1 [Overview of the project] [Problems that the invention aims to solve]

[0006] This disclosure aims to provide a new etching gas containing hexafluoro-2-butyne. [Means for solving the problem]

[0007] This disclosure includes the following components:

[0008] Section 1. Etching gas, (1) 1,1,1,4,4,4-Hexafluoro-2-butyne (CF3C≡CCF3), and, (2) (2-1) At least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period; and, (2-2) At least one component selected from the group consisting of a compound having 2 or 3 carbon atoms and having one double bond or triple bond; An etching gas containing the above.

[0009] Item 2. In the above etching gas, with respect to the total amount of the etching gas, the content of the above (1) 1,1,1,4,4,4-hexafluoro-2-butyne is 99% by volume or more and 99.9995% by volume or less, the above (2) when the composition contains (2-1) the above metal element, the content of the above metal element is 0.5 mass ppb or more and 40 mass ppb or less, or when the composition contains (2-2) the above compound, the content of the above compound is 0.5 volume ppm or more and 95 volume ppm or less. The etching gas according to Item 1 above.

[0010] Item 3. The above (2) (2-1) The above metal element is the metal element in the third period is at least one metal element selected from the group consisting of sodium (Na), magnesium (Mg), and aluminum (Al), the metal element in the fourth period is at least one metal element selected from the group consisting of calcium (Ca) and iron (Fe). The etching gas according to Item 1 above.

[0011] Item 4. The above (2) (2-2) The above compound is a halogenated ethylene compound represented by the formula CF2=CFX (where X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)), and hexafluoropropene (CF3-CF=CF2) At least one halogenated alkene compound selected from the group consisting of The etching gas according to item 1 above.

[0012] Item 5. The above (2) (2-2) The compound is A halogenated alkyne compound represented by the formula CF3C≡CX (where X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)). The etching gas according to item 1 above.

[0013] Item 6. When the composition The above (2) (2-1) When containing the metal element, Furthermore, (3) it contains water, In the etching gas, with respect to the total amount of the etching gas, The content of the above (3) water is 0.1 volume ppm or more and 20 volume ppm or less. The etching gas according to item 1 above.

[0014] Item 7. An etching method for etching a silicon-based material on which a silicon oxide film or a silicon nitride film is formed with the gas plasma of the (A) etching gas according to any one of claims 1 to 6.

[0015] Item 8. The etching method according to item 7 above, wherein the silicon-based material is a substrate for semiconductor manufacturing.

[0016] Item 9. The above (A) etching gas and (B) an inert gas are Separately and continuously supplied to generate an etching mixed gas in the chamber, To etch the silicon-based material, The etching method according to item 7 above.

[0017] Section 10. The etching gas (A) and, (C) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. Etching silicon-based materials, The etching method described in item 7 above.

[0018] Section 11. The etching gas (A) and, (B) Inert gas and, (C) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. Etching silicon-based materials, The etching method described in item 7 above.

[0019] This disclosure discloses an etching gas containing hexafluoro-2-butyne (CF3C≡CCF3). According to this disclosure, an etching gas containing hexafluoro-2-butyne can be used to etch silicon-based materials containing silicon oxide films (SiO2 films), silicon nitride films (SiN films), or photoresist (PR, etching mask) materials, by containing at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period, or by containing a compound having 2 or 3 carbon atoms and having one double or triple bond (halogenated alkene compounds (olefin compounds) and halogenated alkyne compounds).

[0020] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate metal concentration by adjusting the content of metal elements to 40 mass ppb or less, suppressing the inclusion of metal in the formed deposited film, allowing the deposited film to maintain an appropriate hardness, maintaining an appropriate etching rate for the amorphous carbon layer (ACL), and exhibiting good selectivity for SiO2 film / ACL or SiN film / ACL.

[0021] The etching gas containing hexafluoro-2-butyne of this disclosure has an appropriate metal concentration, the deposited film maintains an appropriate hardness, the etching rate of the SiO2 film is appropriate, and the selectivity of the SiO2 film / ACL or SiN film / ACL is good, particularly by adjusting the content of the metal element to 0.5 mass ppb or more.

[0022] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate concentration of compounds having 2 or 3 carbon atoms and one double or triple bond, by adjusting the content to 95 ppm by volume or less. This suppresses the progression of PR etching mainly due to the activity derived from the double (olefin) or triple bond, and the selectivity of the SiO2 film / PR material is good. Furthermore, the etching gas containing hexafluoro-2-butyne of this disclosure suppresses the formation of a large amount of deposited film, and the etching rate is good.

[0023] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate concentration of compounds having 2 or 3 carbon atoms and one double or triple bond, by adjusting the content to 0.5 ppm by volume or more, thereby maintaining a good protective effect by the compounds and having good selectivity for SiO2 film / PR material. [Effects of the Invention]

[0024] According to this disclosure, it is possible to provide a new etching gas containing hexafluoro-2-butyne. [Modes for carrying out the invention]

[0025] In this specification, "contains" is a concept that encompasses all of "contains," "consist essentially of," and "consist of." In this specification, when a numerical range is indicated as "A to B," it means "greater than or equal to A and less than or equal to B." In this specification, when expressions such as parts and percentages are used, they represent parts by mass, parts by weight, mass%, or weight% (wt%).

[0026] [1] Etching gas This disclosure provides an etching gas containing hexafluoro-2-butyne (CF3C≡CCF3). The etching gas of this disclosure contains hexafluoro-2-butyne (CF3C≡CCF3) and suppresses polymerization (dimerization, etc.) of alkyne compounds, suppresses pore blockage, and suppresses a decrease in etching performance by adjusting the concentration of specific metal elements, or specific alkene and / or alkyne compounds.

[0027] The etching gas of this disclosure is (1) 1,1,1,4,4,4-Hexafluoro-2-butyne (CF3C≡CCF3); (2) Contains at least one metallic element selected from the group consisting of metallic elements in the third period and metallic elements in the fourth period.

[0028] The etching gas of this disclosure is preferably, in the etching gas, with respect to the total amount of etching gas, The content of (1) 1,1,1,4,4,4-hexafluoro-2-butyne is 99% by volume or more and 99.9995% by volume or less. The content of the metal element in (2) above is 0.5 mass ppb or more and 40 mass ppb or less.

[0029] The etching gas of this disclosure preferably comprises the (2) metal element, The metallic elements in the third period are at least one metallic element selected from the group consisting of sodium (Na), magnesium (Mg), and aluminum (Al). The metallic elements in the fourth period are at least one metallic element selected from the group consisting of calcium (Ca) and iron (Fe).

[0030] The etching gas of this disclosure preferably further contains (3) water, and in the etching gas, with respect to the total amount of etching gas, The water content in (3) above is 0.1 ppm by volume or more and 20 ppm by volume or less.

[0031] According to this disclosure, an etching gas containing hexafluoro-2-butyne contains at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period. By using this etching gas to etch silicon oxide films (SiO2 films), silicon nitride films (SiN films), or silicon-based materials containing photoresist (PR, etching mask) materials, good etching can be achieved.

[0032] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate metal concentration by adjusting the content of metal elements to 40 mass ppb or less, suppressing the inclusion of metal in the formed deposited film, allowing the deposited film to maintain an appropriate hardness, maintaining an appropriate etching rate for the amorphous carbon layer (ACL), and exhibiting good selectivity for SiO2 film / ACL or SiN film / ACL.

[0033] The etching gas containing hexafluoro-2-butyne of this disclosure has an appropriate metal concentration, the deposited film maintains an appropriate hardness, the etching rate of the SiO2 film is appropriate, and the selectivity of the SiO2 film / ACL or SiN film / ACL is good, particularly by adjusting the content of the metal element to 0.5 mass ppb or more.

[0034] The etching gas of this disclosure is (1) 1,1,1,4,4,4-Hexafluoro-2-butyne (CF3C≡CCF3); (2) Compounds having 2 or 3 carbon atoms and possessing one double or triple bond; It contains.

[0035] The etching gas of this disclosure is preferably, in the etching gas, with respect to the total amount of etching gas, The content of (1) 1,1,1,4,4,4-hexafluoro-2-butyne is 99% by volume or more and 99.9995% by volume or less. The content of compounds having 2 or 3 carbon atoms and possessing one double or triple bond is 0.5 ppm by volume or more and 95 ppm by volume or less.

[0036] The etching gas of this disclosure is preferably compound (2) said to be Halide ethylene compounds represented by the formula CF2=CFX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I), and Hexafluoropropene (CF3-CF=CF2) It is at least one halogenated alkene compound (olefin compound) selected from the group consisting of the following.

[0037] The etching gas of this disclosure is preferably compound (2) said to be It is a halogenated alkyne compound represented by the formula CF3C≡CX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)).

[0038] According to this disclosure, etching gases containing hexafluoro-2-butyne contain compounds (halogenated alkene compounds and halide alkyne compounds) having 2 or 3 carbon atoms and one double or triple bond, and when this etching gas is used to etch silicon oxide films (SiO2 films), silicon nitride films (SiN films), or silicon-based materials containing photoresist (PR, etching mask) materials, good etching can be performed.

[0039] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate concentration of compounds having 2 or 3 carbon atoms and one double or triple bond, by adjusting the content to 95 ppm by volume or less. This suppresses the progression of PR etching mainly due to the activity derived from these compounds, and the selectivity of the SiO2 film / PR material is good. Furthermore, the etching gas containing hexafluoro-2-butyne of this disclosure suppresses the formation of a large amount of deposited film, and the etching rate is good.

[0040] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate concentration of compounds having 2 or 3 carbon atoms and one double or triple bond, by adjusting the content to 0.5 ppm by volume or more, thereby maintaining a good protective effect by the compounds and having good selectivity for SiO2 film / PR material.

[0041] (1) 1,1,1,4,4,4-Hexafluoro-2-butyne (CF 3 C≡CCF 3 ) The etching gas of this disclosure contains (1) 1,1,1,4,4,4-hexafluoro-2-butyne as the main component of the first component.

[0042] In etching gases, from the viewpoint of suppressing polymerization (dimerization, etc.) of halogenated alkyne compounds, suppressing blockage of pores, and suppressing a decrease in etching performance, preferably, the content of (1) 1,1,1,4,4,4-hexafluoro-2-butyne in relation to the total amount (gas volume) of etching gas is 99% by volume or more and 99.9995% by volume or less, 99% by volume or more and 99.999% by volume or less, more preferably 99.05% to 99.995% by volume, even more preferably 99.1% to 99.99% by volume, and particularly preferably 99.5% to 99.95% by volume.

[0043] (2)(2-1) At least one metallic element selected from the group consisting of metallic elements in the third period and metallic elements in the fourth period; and, (2-2) At least one component selected from the group consisting of compounds having 2 or 3 carbon atoms and possessing one double or triple bond;

[0044] (2-1) At least one metallic element selected from the group consisting of metallic elements in the third period and metallic elements in the fourth period. The etching gas of this disclosure contains, as a second component, at least one metal element selected from the group consisting of (2) metal elements in the third period and metal elements in the fourth period.

[0045] (2) From the viewpoint of suppressing polymerization (dimerization, etc.) of the alkyne halide compound, suppressing blockage of pores, and suppressing a decrease in etching performance, the metal element is preferably at least one metal element selected from the group consisting of sodium (Na), magnesium (Mg), and aluminum (Al) in the third period.

[0046] (2) From the viewpoint of suppressing polymerization (dimerization, etc.) of the alkyne halide compound, suppressing blockage of pores, and suppressing a decrease in etching performance, the metal element is preferably at least one metal element selected from the group consisting of calcium (Ca) and iron (Fe) in the fourth period.

[0047] The etching gas may be (2) a single metal element, or a mixture (blend) of two or more elements.

[0048] In etching gases, from the viewpoint of suppressing polymerization (dimerization, etc.) of halide alkyne compounds, suppressing pore blockage, and suppressing a decrease in etching performance, preferably, the content of (2) metal elements (total amount of metal elements when the metal elements consist of one type alone or two or more types) relative to the total amount of etching gas is 0.5 mass ppb (wtppb) or more and 40 mass ppb (wtppb) or less, more preferably 0.75 mass ppb to 35 mass ppb, even more preferably 1 mass ppb to 30 mass ppb, and particularly preferably 1.2 mass ppb to 25 mass ppb.

[0049] By using an etching gas containing 1,1,1,4,4,4-hexafluoro-2-butyne and ensuring a metal element content of 0.5 mass ppb or more, the hardening of the deposited film during etching is suppressed, resulting in high etching rates for SiO2 and SiN films, and high selectivity (selectivity ratio) for SiO2 / ACL and SiN / ACL.

[0050] By using an etching gas containing 1,1,1,4,4,4-hexafluoro-2-butyne and limiting the metallic element content to 40 mass ppb or less, the inclusion of metal in the formed deposited film during etching is suppressed, resulting in a deposited film with appropriate hardness. This reduces the etching rate of ACL, and the selectivity for SiO2 film / ACL and SiN film / ACL is high.

[0051] (2-2) Compounds having 2 or 3 carbon atoms and possessing one double or triple bond. (Alkene compounds and alkyne compounds) The etching gas of this disclosure contains, as a second component, (2) a compound having 2 or 3 carbon atoms and one double or triple bond (halogenated alkene compounds and haliden alkyne compounds).

[0052] (2) The compound is preferably at least one halogenated alkene compound (olefin compound) selected from the group consisting of halogenated ethylene compounds represented by the formula CF2=CFX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)) and hexafluoropropene (CF3-CF=CF2), in order to suppress polymerization (dimerization, etc.) of halogenated alkyne compounds (1,1,1,4,4,4-hexafluoro-2-butyne, CF3C≡CCF3), suppress blockage of pores, and suppress a decrease in etching performance.

[0053] (2) The compound is preferably at least one halogenated alkene compound (olefin compound) selected from the group consisting of chlorotrifluoroethylene (CTFE) and / or hexafluoropropene (HFP), from the viewpoint of suppressing polymerization (dimerization, etc.) of the halogenated alkyne compound (CF3C≡CCF3), suppressing pore blockage, and suppressing a decrease in etching performance, and even more preferably chlorotrifluoroethylene (CTFE).

[0054] (2) The compound is preferably an alkyne halide compound represented by the formula CF3C≡CX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)), from the viewpoint of suppressing polymerization (dimerization, etc.) of the alkyne halide compound (CF3C≡CCF3), suppressing pore blockage, and suppressing a decrease in etching performance. The alkyne halide compound represented by the formula CF3C≡CX may be used alone or as a mixture (blend) of two or more types.

[0055] (2) The compound is preferably at least one halide alkyne compound selected from the group consisting of CF3C≡CH, CF3C≡CCl, and / or CF3C≡CBr, from the viewpoint of suppressing polymerization (dimerization, etc.) of the halide alkyne compound (CF3C≡CCF3), suppressing pore blockage, and suppressing a decrease in etching performance.

[0056] The etching gas may be (2) compound used alone, or a mixture (blend) of two or more compounds.

[0057] In etching gas, from the viewpoint of suppressing polymerization (dimerization, etc.) of halogenated alkyne compounds (CF3C≡CCF3), suppressing pore blockage, and suppressing a decrease in etching performance, preferably, the content of (2) compound (or the total amount of (2) compound when (2) compound is included as one type or two or more types) relative to the total amount of etching gas is 0.5 volume ppm or more and 95 volume ppm or less, more preferably 0.75 volume ppm to 93 volume ppm, even more preferably 1.0 volume ppm to 90 volume ppm, and particularly preferably 1.5 volume ppm to 85 volume ppm.

[0058] In the etching gas, by including 1,1,1,4,4,4-hexafluoro-2-butyne and ensuring that the content of compound (2) is 0.5 ppm by volume or more, a protective effect is observed during etching, and the selectivity (selectivity ratio) of the SiO2 film / PR is high.

[0059] In the etching gas, by including 1,1,1,4,4,4-hexafluoro-2-butyne and keeping the content of compound (2) below 95 ppm by volume, etching of PR mainly by the active compound (2) is suppressed during etching, and the selectivity of SiO2 film / PR is good. In the etching gas, by including 1,1,1,4,4,4-hexafluoro-2-butyne and keeping the content of compound (2) below 95 ppm by volume, the formation of a large amount of deposited film (deposition film) during etching is suppressed, and the etching rate is high.

[0060] (3)Water When the etching gas of this disclosure contains as a second component (2-1) at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period, it is preferable to further contain as a third component (3) water, from the viewpoint of suppressing polymerization (dimerization, etc.) of alkyne halide compounds, suppressing blockage of pores, and suppressing a decrease in etching performance.

[0061] In etching gas, when the second component contains (2-1) at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period, from the viewpoint of suppressing polymerization (dimerization, etc.) of the halide alkyne compound, suppressing blockage of pores, and suppressing a decrease in etching performance, the water content (3) relative to the total amount (gas volume) of etching gas is preferably 0.1 volume ppm or more and 20 volume ppm or less, more preferably 0.5 volume ppm to 15 volume ppm, even more preferably 1 volume ppm to 10 volume ppm, and particularly preferably 1.5 volume ppm to 7.5 volume ppm.

[0062] (4) Amount of etching gas used The etching gas of this disclosure contains (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as a first component, and (2) at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period as a second component, and additionally contains (3) water.

[0063] The etching gas of this disclosure contains (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as a first component, and (2) a compound having 2 or 3 carbon atoms and one double or triple bond as a second component.

[0064] From the viewpoint of efficiently and effectively carrying out etching, the amount of etching gas used in this disclosure is preferably 2 ccm to 100 ccm, more preferably 5 ccm to 50 ccm, and even more preferably 8 ccm to 15 ccm.

[0065] In this specification, the unit of gas consumption "ccm" represents cubic centimetre / min (cc / min), and is the volume (CC, cm³) when an instantaneous flow rate is maintained for 1 minute under conditions of 25°C and 1 atmosphere. 3 ) represents.

[0066] (5) Other etching gases The etching gas of this disclosure may contain other etching gases as needed, from the viewpoint of promoting good etching.

[0067] The etching rate can be adjusted by using other etching gases, preferably hydrofluorocarbon compounds (HFCs) such as CH2F2, CHF3, C2H2F2, C2H4F2, and C3H2F4; perfluorocarbon compounds (PFCs) such as CF4, C2F6, C3F8, C4F8, C4F6, and C5F8; iodides such as CF3I, C2F5I, and C3F7I; and SF6.

[0068] The etching gas of this disclosure may be used as a single etching gas or as a mixture (blend) of two or more etching gases.

[0069] [2] Method of etching This disclosure includes a method for etching a semiconductor manufacturing substrate using the etching gas of this disclosure as a gas supplied to generate plasma.

[0070] The etching method of this disclosure involves etching a silicon-based material on which a silicon oxide film (SiO2 film) or a silicon nitride film (SiN film) has been formed using a gas plasma of the etching gas (A) of this disclosure.

[0071] The silicon-based material is preferably a substrate for semiconductor manufacturing.

[0072] The etching method preferably involves continuously supplying (A) an etching gas and (B) an inert gas separately to generate an etching mixture gas in a chamber and etching the silicon-based material.

[0073] The etching method preferably involves continuously supplying (A) an etching gas and (C) an oxidizing gas and / or a reducing gas separately to generate an etching mixed gas in a chamber and etching the silicon-based material.

[0074] The etching method preferably involves continuously supplying (A) an etching gas, (B) an inert gas, and (C) an oxidizing gas and / or a reducing gas separately to generate an etching mixture gas in a chamber and etching the silicon-based material.

[0075] By using the etching gas of this disclosure, hole etching can be performed on silicon-based materials containing a silicon oxide film (SiO2 film) or a silicon nitride film (SiN film) using the generated gas plasma, resulting in etching that maintains the processed shape of the holes well. The conditions of the etching method (especially the dry etching method) can be the same as those of conventional methods, except for the use of the etching gas of this disclosure.

[0076] (1) Examples of etching conditions The conditions for etching using the etching gas of this disclosure are, for example, as follows:

[0077] The flow rate should be adjusted to 5 ccm to 2,000 ccm, preferably 10 ccm to 1,000 ccm.

[0078] The discharge power is adjusted to 200W to 20,000W, preferably 400W to 10,000W. The high-frequency power supply should be adjusted to 13.56MHz and 0.22W. The bias power is adjusted to 25 W to 15,000 W, preferably 100 W to 10,000 W.

[0079] The pressure is adjusted to 30 mTorr or less (3.99 Pa or less), preferably 2 mTorr to 10 mTorr (0.266 Pa to 1.33 Pa). Unless otherwise specified, the pressure indicates the gauge pressure.

[0080] Electron density 10 9 cm -3 ~10 13 cm -3 Preferably, 10 10 cm -3 ~10 12 cm -3 is adjusted. The electron temperature is adjusted to 2 eV to 9 eV, preferably 3 eV to 8 eV.

[0081] The wafer temperature is adjusted to -40°C to 100°C, preferably -30°C to 50°C. The chamber wall temperature is adjusted to -30°C to 300°C, preferably 20°C to 200°C.

[0082] The discharge power and the bias power also vary depending on the size of the chamber, the size of the electrode, etc. The preferred etching conditions when etching a pattern such as a contact hole on a silicon oxide film or the like with an inductively coupled plasma (ICP) etching apparatus for a small-diameter wafer (chamber volume 3,500 cm 3 ) can be as follows.

[0083] The discharge power is adjusted to 200 W to 1,000 W, preferably 300 W to 600 W. The bias power is adjusted to 50 W to 500 W, preferably 100 W to 300 W.

[0084] (2) Inert gas When etching is performed using the etching gas of this disclosure, the etching gas may contain an inert gas as needed, from the viewpoint of ensuring good etching.

[0085] The etching method preferably involves supplying an etching gas and an inert gas separately and continuously to generate an etching mixture gas in a chamber, and then etching the silicon-based material.

[0086] The inert gas may preferably contain one or more noble gases, such as nitrogen. The noble gas may preferably contain helium, neon, argon, xenon, krypton, etc., and more preferably argon (Ar).

[0087] When etching is performed using etching gas, the inert gas may be used alone or mixed (blended) with two or more types.

[0088] Inert gases can alter the electron temperature and electron density of a plasma, allowing for control over the balance of fluorocarbon radicals and fluorocarbon ions.

[0089] When etching is performed using an etching gas, if an inert gas (such as Ar) is included, the amount of inert gas used is preferably 50 ccm to 500 ccm, more preferably 150 ccm to 400 ccm, and even more preferably 220 ccm to 280 ccm, from the viewpoint of ensuring good etching.

[0090] When etching is performed using etching gas, if an inert gas (such as Ar) is included, the amount of inert gas used is preferably 5 to 50 times the amount of etching gas flow rate, more preferably 15 to 40 times, and even more preferably 22 to 28 times, from the viewpoint of promoting good etching.

[0091] (3) Oxidizing gases and / or reducing gases When etching is performed using the etching gas of this disclosure, the etching gas may contain an oxidizing gas and / or a reducing gas as needed, from the viewpoint of promoting good etching.

[0092] The etching method preferably involves supplying an etching gas and an oxidizing gas and / or a reducing gas separately and continuously to generate an etching mixture gas in a chamber and etching the silicon-based material.

[0093] Preferably, using an oxidizing gas such as O2, O3, NO, N2O, NO2, SO2, COS, CO, or CO2, and more preferably using oxygen (O2), will allow for a good etching shape to be obtained.

[0094] When etching is performed using etching gas, one type of oxidizing gas may be used alone, or two or more types may be mixed (blended) together.

[0095] When etching is performed using an etching gas, if an oxidizing gas (such as O2) is included, the amount of oxidizing gas used is preferably 2 ccm to 100 ccm, more preferably 5 ccm to 50 ccm, and even more preferably 8 ccm to 15 ccm, from the viewpoint of efficiently and effectively carrying out etching.

[0096] When etching is performed using etching gas, if an oxidizing gas (such as O2) is present, the amount of oxidizing gas used is preferably 0.2 to 10 times the amount of the etching gas flow rate, more preferably 0.5 to 5 times, and even more preferably 0.8 to 1.5 times, from the viewpoint of efficiently and effectively carrying out etching.

[0097] By using a reducing gas such as hydrogen (H2), CO, or CH4, it is possible to obtain a good etching shape, especially when performing hole etching on silicon-based materials containing a silicon nitride film (SiN film).

[0098] When etching is performed using etching gas, the reducing gas may be used alone or mixed (blended) with two or more types.

[0099] When etching is performed using an etching gas, if a reducing gas (such as H2) is included, the amount of reducing gas used is preferably 0.5 ccm to 20 ccm, more preferably 0.8 ccm to 10 ccm, and even more preferably 1 ccm to 5 ccm, from the viewpoint of efficiently and effectively carrying out etching.

[0100] When etching is performed using etching gas, if it contains a reducing gas (such as H2), the amount of reducing gas used is preferably 0.05 to 2 times the amount of the etching gas flow rate, more preferably 0.08 to 1 time, and even more preferably 0.1 to 0.5 times, from the viewpoint of efficiently and effectively carrying out etching.

[0101] When etching is performed using etching gas, an oxidizing gas and a reducing gas may be used individually, or two or more may be mixed (blended).

[0102] The etching method preferably involves continuously supplying an etching gas, an inert gas, and an oxidizing gas and / or a reducing gas separately to generate an etching mixture gas in a chamber and etching the silicon-based material.

[0103] [3] Semiconductor manufacturing equipment This disclosure includes a semiconductor manufacturing apparatus having a gas ejection section for etching gas of this disclosure.

[0104] [4] Semiconductor manufacturing methods This disclosure includes a semiconductor manufacturing method, which involves etching a semiconductor manufacturing substrate using the etching gas of this disclosure.

[0105] [5] Use for semiconductor manufacturing This disclosure includes the use of the etching gases of this disclosure for semiconductor manufacturing, specifically for etching semiconductor manufacturing substrates.

[0106] The etching gas of this disclosure contains (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as a first component, and (2) at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period as a second component, and additionally contains (3) water. When hole etching is performed using the etching gas of this disclosure, it is possible to suppress hole clogging in the processed shape, reduce side etching, and perform etching while maintaining the processed shape of the hole (deep hole) in good condition.

[0107] The etching gas of this disclosure contains (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as a first component, and (2) a compound having 2 or 3 carbon atoms and one double or triple bond as a second component. When hole etching is performed using the etching gas of this disclosure, it is possible to suppress hole clogging in the processed shape, reduce side etching, and perform etching while maintaining the processed shape of the hole (deep hole) in good condition.

[0108] The etching gas of this disclosure can suppress polymerization (dimerization, etc.) of alkyne halogen compounds in the etching gas, suppress blockage of pores, and suppress a decrease in etching performance. [Examples]

[0109] The present invention will be described in detail below using examples and comparative examples. However, the present invention is not limited to these.

[0110] (Example 1) Second component: At least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period. [1] Etching method An etching gas containing (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as the first component, (2) at least one metal element selected from the group consisting of metal elements in the third period and metal elements in the fourth period, and (3) water as the second component was introduced through a gas inlet connected to the upper electrode. The process gas was then excited by a high-frequency power supply (13.56 MHz, 0.22 W) to perform etching.

[0111] Etching gases—oxygen (oxidizing gas), Ar (inert gas), and hydrogen (reducing gas, used when etching SiN films)—were supplied from separate lines to form a mixed etching gas in the chamber, and etching was performed.

[0112] ICP (Inductive Coupled Plasma), discharge power 1,000W, bias power 300W, pressure 10mTorr, electron density 8×10 10 cm -3 ~2×10 11 cm -3 Etching was performed on silicon oxide films (SiO2 films) and silicon nitride films (SiN films) formed on silicon substrates under etching conditions of electron temperature [5eV~7eV].

[0113] [2]SiO 2 Measurement of selectivity for membrane / ACL and SiN membrane / ACL The selectivity of silicon oxide films (SiO2 films) and silicon nitride films (SiN films) for amorphous carbon layers (ACLs) was measured by observing the cross-sections of silicon wafers after etching with SiO2 films and SiN films using SEM. SiO2 film / ACL: Etching rate of the SiO2 film on ACL SiN film / ACL: Etching rate of SiN film relative to ACL

[0114] [Table 1]

[0115] When etching was performed on silicon-based materials containing SiO2 and SiN films using the etching gas of the example, the etching performance did not decrease, and etching with a high selectivity ratio between SiO2 film / ACL and SiN film / ACL was achieved.

[0116] (Example 2) Second component: A compound having 2 or 3 carbon atoms and one double or triple bond (halogenated alkene compounds and haliden alkyne compounds) [1] Etching method An etching gas containing (1) 1,1,1,4,4,4-hexafluoro-2-butyne (CF3C≡CCF3) as the first component and (2) a compound having 2 or 3 carbon atoms and one double or triple bond as the second component was introduced through a gas inlet connected to the upper electrode. Then, the process gas was excited by a high-frequency power supply (13.56 MHz, 0.22 W) and etching was performed.

[0117] Etching gases—oxygen (oxidizing gas), Ar (inert gas), and hydrogen (reducing gas, used when etching SiN films)—were supplied from separate lines to form a mixed etching gas in the chamber, and etching was performed.

[0118] ICP (Inductive Coupled Plasma), discharge power 1,000W, bias power 300W, pressure 10mTorr, electron density 8×10 10 cm -3 ~2×10 11 cm -3 Etching was performed on a silicon oxide film (SiO2 film) formed on a silicon substrate under etching conditions of electron temperature [5eV~7eV].

[0119] [2]SiO 2 Measurement of membrane / PR selectivity The selectivity of silicon oxide films (SiO2 films) for photoresist (PR, etching mask) materials was measured by observing the cross-section of silicon wafers after etching with SiO2 films and SiN films using SEM. SiO2 film / PR: Etching rate of SiO2 film relative to PR

[0120] [Table 2]

[0121] [Table 3]

[0122] When etching was performed on a silicon-based material containing an SiO2 film using the etching gas of the example, the etching performance did not decrease, and etching with a high selectivity ratio of SiO2 film to PR was possible.

[0123] [3] Industrial applicability The etching gas of this disclosure suppresses polymerization (dimerization, etc.) of alkyne halide compounds, suppresses pore blockage, and suppresses a decrease in etching performance by adjusting the concentration of a specific metal element, or by using specific alkene halide compounds and alkyne halide compounds and adjusting the concentration of said compounds.

[0124] The etching gas of this disclosure contains hexafluoro-2-butyne and also contains at least one component selected from the group consisting of metal elements in the third period and metal elements in the fourth period, and compounds having 2 or 3 carbon atoms and having one double or triple bond. As a result, when etching is performed using this etching gas on silicon oxide films (SiO2 films), silicon nitride films (SiN films), or silicon-based materials containing photoresist (PR, etching mask) materials, good etching can be performed.

[0125] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate metal concentration by adjusting the content of metal elements to 40 mass ppb or less, suppressing the inclusion of metal in the formed deposited film, allowing the deposited film to maintain an appropriate hardness, maintaining an appropriate etching rate for the amorphous carbon layer (ACL), and exhibiting good selectivity for SiO2 film / ACL or SiN film / ACL.

[0126] The etching gas containing hexafluoro-2-butyne of this disclosure has an appropriate metal concentration, the deposited film maintains an appropriate hardness, the etching rate of the SiO2 film is appropriate, and the selectivity of the SiO2 film / ACL or SiN film / ACL is good, particularly by adjusting the content of the metal element to 0.5 mass ppb or more.

[0127] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, adjusts the content of compounds having 2 or 3 carbon atoms and one double or triple bond to 95 ppm by volume or less, resulting in an appropriate concentration of such compounds. This suppresses the progression of PR etching mainly due to the activity derived from these compounds (halogenated alkene compounds and halide alkyne compounds), and the selectivity of the SiO2 film / PR material is good. Furthermore, the etching gas containing hexafluoro-2-butyne of this disclosure suppresses the formation of large deposit films, resulting in a good etching rate.

[0128] The etching gas containing hexafluoro-2-butyne of this disclosure, in particular, has an appropriate concentration of compounds having 2 or 3 carbon atoms and one double or triple bond, by adjusting the content to 0.5 ppm by volume or more, thereby maintaining a good protective effect by the compounds (halogenated alkene compounds (olefin compounds) and halide alkyne compounds), and exhibiting good selectivity for SiO2 film / PR material.

Claims

1. Etching gas, (1) 1,1,1,4,4,4-Hexafluoro-2-butyne (CF 3 C≡CCF 3 ),and, （2） (2-1) At least one metallic element selected from the group consisting of metallic elements in the third period and metallic elements in the fourth period; and, (2-2) At least one component selected from the group consisting of compounds having 2 or 3 carbon atoms and possessing one double or triple bond; Etching gas containing [this substance].

2. In the etching gas, with respect to the total amount of etching gas, The content of (1) 1,1,1,4,4,4-hexafluoro-2-butyne is 99% by volume or more and 99.9995% by volume or less. (2) above When the composition (2-1) contains the metal element, the content of the metal element is 0.5 ppb by mass or more and 40 ppb by mass or less, When the composition contains (2-2) the compound, the content of the compound is 0.5 ppm by volume or more and 95 ppm by volume or less. The etching gas according to claim 1.

3. (2) above (2-1) The metal element is The metal element in the third period is at least one metal element selected from the group consisting of sodium (Na), magnesium (Mg), and aluminum (Al). The metallic elements in the fourth period are at least one metallic element selected from the group consisting of calcium (Ca) and iron (Fe). The etching gas according to claim 1.

4. (2) above (2-2) The compound is formula CF 2 Halide ethylene compounds represented by =CFX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I), and Hexafluoropropene (CF 3 -CF=CF 2 ) At least one halogenated alkene compound selected from the group consisting of the following: The etching gas according to claim 1.

5. (2) above (2-2) The compound is formula CF 3 C≡CX (wherein X represents a hydrogen atom (H), a chlorine atom (Cl), a bromine atom (Br), or an iodine atom (I)) is a halogenated alkyne compound. The etching gas according to claim 1.

6. composition (2) above (2-1) When the metal element is included, Furthermore, (3) containing water, In the etching gas, with respect to the total amount of etching gas, The water content in (3) above is 0.1 ppm by volume or more and 20 ppm by volume or less. The etching gas according to claim 1.

7. An etching method comprising etching a silicon-based material on which a silicon oxide film or silicon nitride film is formed using a gas plasma of the etching gas (A) described in any one of claims 1 to 6.

8. The etching method according to claim 7, wherein the silicon-based material is a substrate for semiconductor manufacturing.

9. The etching gas (A) and (B) with an inert gas, The etching mixture gas is supplied separately and continuously within the chamber. Etching silicon-based materials, The etching method according to claim 7.

10. The etching gas (A) and (C) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. Etching silicon-based materials, The etching method according to claim 7.

11. The etching gas (A) and (B) an inert gas, and (C) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. Etching silicon-based materials, The etching method according to claim 7.

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