Dry etching method, method for manufacturing semiconductor device, etching apparatus, and etching gas composition

Abstract

The purpose of the present invention is to provide: a dry etching method whereby silicon can be selectively etched; a method for manufacturing a semiconductor device; an etching apparatus; and an etching gas composition. The present invention relates to a dry etching method for using a fluorine-containing compound gas and an organic amine gas to selectively etch silicon and the silicon within at least one substance selected from the group consisting of silicon-germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

Description

Dry etching method, semiconductor device manufacturing method, etching apparatus, and etching gas composition

[0001] The present disclosure relates to a dry etching method, a method for manufacturing a semiconductor device, an etching apparatus, and an etching gas composition.

[0002] In the manufacturing process of semiconductor devices, there is a demand for technology that can etch silicon with high selectivity relative to other materials. Among these, technology that can selectively etch silicon from structures containing silicon and silicon germanium is essential for the manufacture of next-generation technologies such as three-dimensional NAND flash memory (3D-NAND) and dynamic random access memory (DRAM). Furthermore, due to the device structures of 3D-NAND and DRAM, there is a demand for technology that can selectively etch silicon without using plasma processes.

[0003] As a technique for selectively etching silicon from a structure containing silicon and silicon germanium, there is a technique for etching using a gas containing germanium without a plasma state (Patent Document 1), and a technique for selectively etching silicon from a structure containing silicon germanium without a plasma state (Patent Document 2). ３ and F ２ A technique for etching without plasma using a mixed gas of the above is known (Patent Document 2).

[0004] JP 2020-205304 A JP 2016-143781 A

[0005] As a result of investigations by the present inventors, it has become clear that the techniques described in Patent Documents 1 and 2 have room for improvement in terms of selectively etching silicon relative to other materials, and there is a concern that a desired processed shape may not be achieved.

[0006] The present disclosure aims to solve the above-mentioned problems and to provide a dry etching method capable of selectively etching silicon, a method for manufacturing a semiconductor device, an etching apparatus, and an etching gas composition.

[0007] As a result of extensive research, the present inventors have discovered that silicon can be selectively etched from among other materials using a fluorine-containing compound gas and an organic amine gas, and have thus completed the present disclosure.

[0008] In other words, the present disclosure (1) relates to a dry etching method for selectively etching silicon with a fluorine-containing compound gas and an organic amine gas, using silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

[0009] (2) The present disclosure states that the fluorine-containing compound is IF ７ , IF ５ , BrF ５ , BrF ３ , CLF ３ ClF, MoF ６ and WF ６ The present disclosure (1) relates to a dry etching method, which is at least one selected from the group consisting of the following.

[0010] The present disclosure (3) relates to a dry etching method according to the present disclosure (1) or (2), wherein the organic amine is at least one selected from the group consisting of trimethylamine, triethylamine, dimethylamine, dimethylethylamine, monomethylamine, diethylmethylamine, monoethylamine, diethylamine, monon-normal propylamine, ethylpropylamine, din-normal propylamine, monoisopropylamine, ethylisopropylamine, diisopropylamine, monobutylamine, dibutylamine, monotertiary butylamine, ditertiary butylamine, pyrrolidine, piperidine, piperazine, pyridine, pyrazine, trifluoromethylamine, 1,1,1-trifluorodimethylamine, perfluorodimethylamine, 2,2,2-trifluoroethylamine, perfluoroethylamine, bis(2,2,2-trifluoroethyl)amine, perfluorodiethylamine, and 3-fluoropyridine.

[0011] The present disclosure (4) relates to the dry etching method according to any one of the present disclosures (1) to (3), which selectively etches silicon from at least one selected from the group consisting of silicon germanium, silicon oxide, and silicon nitride.

[0012] The present disclosure (5) relates to the dry etching method according to any one of the present disclosures (1) to (4), in which the etching temperature is −50 to 300° C.

[0013] The present disclosure (6) relates to the dry etching method according to any one of the present disclosures (1) to (4), in which the etching temperature is 140 to 300°C.

[0014] The present disclosure (7) relates to the dry etching method according to any one of the present disclosures (1) to (6), in which the pressure during etching is 1 Pa to 13.3 kPa.

[0015] The present disclosure (8) relates to the dry etching method according to any one of the present disclosures (1) to (7), in which etching is performed without using a plasma state.

[0016] The present disclosure (9) relates to the dry etching method according to any one of the present disclosures (1) to (8), wherein the silicon is any one of a polysilicon film formed on a substrate, an amorphous silicon film formed on a substrate, an epitaxially grown silicon film formed on a substrate, and a single-crystal silicon substrate.

[0017] The present disclosure (10) relates to the dry etching method according to any one of the present disclosures (1) to (9), in which gas A containing the fluorine-containing compound gas and the organic amine gas is brought into contact with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

[0018] The present disclosure (11) relates to the dry etching method according to the present disclosure (10), wherein the amount of the fluorine-containing compound gas contained in the gas A is 1 to 90% by volume.

[0019] The present disclosure (12) relates to the dry etching method according to the present disclosure (10) or (11), wherein the amount of the organic amine gas contained in the gas A is 1 to 50% by volume.

[0020] The present disclosure (13) relates to the dry etching method according to any one of the present disclosures (10) to (12), wherein the volume ratio of the fluorine-containing compound gas to the organic amine gas contained in the gas A is fluorine-containing compound gas:organic amine gas=1:0.01 to 1:100.

[0021] The present disclosure (14) relates to the dry etching method according to any one of the present disclosures (1) to (9), comprising: a first step of contacting gas B containing the organic amine gas with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride; and a second step of contacting gas C containing the fluorine-containing compound gas with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

[0022] The present disclosure (15) relates to a dry etching method in which a step of selectively etching silicon germanium from silicon and silicon germanium using a gas D containing a fluorine-containing compound gas but not an organic amine gas, and a step of selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas are selectively used as desired.

[0023] The present disclosure (16) relates to a method for manufacturing a semiconductor device, comprising a step of selectively etching silicon by applying the dry etching method according to any one of the present disclosures (1) to (14) to silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

[0024] The present disclosure (17) relates to a method for manufacturing a semiconductor device, including a step of selectively etching silicon and / or silicon germanium by applying the dry etching method according to the present disclosure (15) to silicon and silicon germanium.

[0025] The present disclosure (18) relates to an etching apparatus including: a mounting table for mounting an object to be processed; a fluorine-containing compound gas supply unit for supplying a gas containing a fluorine-containing compound gas to the object to be processed; and an organic amine gas supply unit for supplying a gas containing an organic amine gas to the object to be processed.

[0026] This disclosure (19) relates to an etching gas composition comprising a fluorine-containing compound gas and an organic amine gas.

[0027] The dry etching method (1) of the present disclosure is a dry etching method that selectively etches silicon from at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride using a fluorine-containing compound gas and an organic amine gas, and therefore can selectively etch silicon.

[0028] The dry etching method (2) of the present disclosure is a dry etching method in which, as desired, a step of selectively etching silicon germanium from silicon and silicon germanium using gas D containing a fluorine-containing compound gas but not an organic amine gas, and a step of selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas are selectively used. Therefore, the etching target can be changed by the simple operation of changing the gas flow rate.

[0029] The semiconductor device manufacturing method (1) of the present disclosure is a semiconductor device manufacturing method that includes a step of selectively etching silicon by applying the dry etching method (1) of the present disclosure to silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride. Because the semiconductor device manufacturing method (1) of the present disclosure includes a step of etching by applying the dry etching method (1) of the present disclosure, silicon can be selectively etched and high-quality semiconductor devices can be manufactured.

[0030] The semiconductor device manufacturing method (2) of the present disclosure is a semiconductor device manufacturing method that includes a step of selectively etching silicon and / or silicon germanium by applying the dry etching method (2) of the present disclosure to silicon and silicon germanium. Since the semiconductor device manufacturing method (2) of the present disclosure includes a step of etching by applying the dry etching method (2) of the present disclosure, the etching target can be changed by a simple operation of changing the gas flow rate, and semiconductor devices can be manufactured with high productivity.

[0031] The etching apparatus of this disclosure comprises a mounting table on which an object to be processed is placed, a fluorine-containing compound gas supply unit that supplies a gas containing a fluorine-containing compound gas to the object to be processed, and an organic amine gas supply unit that supplies a gas containing an organic amine gas to the object to be processed, thereby enabling selective etching of silicon.

[0032] The etching gas composition of this disclosure contains a fluorine-containing compound gas and an organic amine gas, and is therefore capable of selectively etching silicon.

[0033] Figure 1 is a schematic diagram of the etching apparatus of this disclosure.

[0034] The present disclosure will be described in detail below, but the description of the constituent elements described below is an example of an embodiment of the present disclosure and is not limited to these specific contents. It can be implemented in various ways within the scope of its gist.

[0035] In this specification, unless otherwise specified, the expression "X to Y" in the description of a numerical range means at least X and at most Y. For example, "1 to 5% by mass" means "at least 1% by mass and at most 5% by mass."

[0036] <Dry Etching Method (1)> The dry etching method (1) of the present disclosure is a dry etching method that selectively etches silicon from at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride using a fluorine-containing compound gas and an organic amine gas. This improves selectivity to silicon, allowing for selective etching of silicon. The method of the present disclosure is advantageous in terms of cost because it can selectively etch silicon without using a gas containing germanium, a rare element (also referred to as a germanium-containing compound gas). Therefore, it is possible to provide an etching method that is highly accurate and cost-effective.

[0037] The reason why the above-mentioned effect is obtained is not entirely clear, but it is presumed to be due to the following mechanism. The organic amine, or the product produced when the organic amine is mixed with the fluorine-containing compound, is adsorbed onto the surface of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, or silicon oxycarbonitride, forming a protective layer. Therefore, the fluorine-containing compound selectively etches silicon that does not have a protective layer formed thereon. In this way, the synergistic effect of the fluorine-containing compound gas and the organic amine gas improves selectivity to silicon, allowing silicon to be selectively etched.

[0038] Examples of silicon include polycrystalline silicon (p-Si), amorphous silicon, and single-crystal silicon. For example, silicon films such as polysilicon films, amorphous silicon films, and silicon epitaxial growth films formed on a substrate, and single-crystal silicon substrates are examples. Among these, silicon films are preferred. The epitaxial growth may be homoepitaxial growth when the substrate is a silicon substrate, or heteroepitaxial growth when the substrate is a substrate other than a silicon substrate. The silicon epitaxial growth film is usually a single-crystal silicon film composed of single-crystal silicon.

[0039] At least one material selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbonitride, and silicon oxycarbonitride may be used alone or in combination of two or more. Among these, silicon germanium, silicon oxide, and silicon nitride are preferred, and silicon germanium is more preferred. It is preferable that the silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbonitride, and silicon oxycarbonitride are silicon germanium films, germanium films, silicon oxide films, silicon nitride films, silicon oxynitride films, silicon carbide films, silicon carbonitride films, and silicon oxycarbonitride films, respectively.

[0040] Silicon germanium (SiGe, where SiGe does not indicate the stoichiometric ratio of each element, but means that silicon atoms and germanium atoms are included) includes, for example, Si １－ｘ Ge ｘ Examples include (where x is 0.01 to 0.99, but may be 0.05 to 0.5). Examples of germanium (Ge) include a germanium film formed on a substrate and a germanium substrate. Examples of silicon oxide (SiO, where SiO does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms and oxygen atoms) include SiO ｘ (x is 1 or more and 2 or less), SiO ２For example, silicon nitride (SiN, where SiN does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms and nitrogen atoms) is SiN ｘ (x is between 0.3 and 9), Si ３ N ４ Examples include silicon oxynitride (silicon oxide nitride (SiON), where SiON does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms, oxygen atoms, and nitrogen atoms), silicon oxycarbide (silicon oxide carbide (SiOC), where SiOC does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms, oxygen atoms, and carbon atoms), silicon carbonitride (silicon oxide carbide (SiCN), where SiCN does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms, carbon atoms, and nitrogen atoms), and silicon oxycarbonitride (silicon oxide carbide nitride (SiOCN), where SiOCN does not indicate the stoichiometric ratio of each element, but means that it contains silicon atoms, oxygen atoms, carbon atoms, and nitrogen atoms). Examples of silicon oxycarbide include films with compositions used for semiconductor devices.

[0041] In this specification, "selectively etching silicon" means that the ratio of the etching rates of silicon to other materials (non-silicon materials) (silicon / other material) is 1.1 or higher. The above etching rate ratio is preferably 5 or higher, more preferably 10 or higher, even more preferably 20 or higher, and there is no particular upper limit, but for example, it is 10,000 or less. In this specification, the etching rate is calculated by the method described in the examples.

[0042] In the dry etching method (1) of this disclosure, examples of the workpiece include a silicon substrate, a compound semiconductor substrate, a quartz substrate, and a glass substrate. In addition to the above-mentioned "silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride," a metal wiring film or the like may be formed on the surface of the workpiece.

[0043] The method for forming "silicon and at least one selected from the group consisting of silicon, silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride (collectively referred to as the etched film)" on the surface of the object to be treated is not particularly limited, but examples include chemical vapor deposition (CVD), molecular beam epitaxy (MBE), and sputtering. The thickness of the etched film is also not particularly limited, but for example, it can be between 0.1 nm and 1 μm.

[0044] The dry etching method (1) of the present disclosure uses a fluorine-containing compound gas and an organic amine gas.

[0045] <<Fluorine-Containing Compound Gas>> The fluorine-containing compound gas is not particularly limited as long as it is a gas of a compound containing a fluorine atom. The fluorine-containing compound gas may be used alone or in combination of two or more kinds.

[0046] Examples of the fluorine-containing compound (a compound containing a fluorine atom) include IF ７ , IF ５ , BrF ５ , BrF ３ , CLF ３ ClF, MoF ６ , W.F. ６ These may be used alone or in combination of two or more. ７ , IF ５ , BrF ５ , BrF ３ , CLF ３ , ClF is preferred, IF ７ , BrF ５ , CLF ３ In addition, since the selectivity to silicon can be further improved, interhalogen is preferable, and IF ７ , IF ５ , BrF ５ , BrF ３ , CLF ３ , ClF is more preferred, IF ７ , BrF ５ , CLF ３, ClF is more preferred, IF ７ , CLF ３ is particularly preferred, and ClF ３ In this specification, the term "interhalogen" refers to a compound composed of multiple types of halogen atoms (e.g., fluorine atoms and iodine atoms). The fluorine-containing compound preferably excludes hydrogen fluoride (HF).

[0047] The gas containing a fluorine-containing compound gas is not particularly limited as long as it contains a fluorine-containing compound gas, but may contain an inert gas or the like in addition to the fluorine-containing compound gas.

[0048] Examples of inert gases include Ar and N. ２ Examples include He, Ne, and Kr. These may be used individually or in combination of two or more.

[0049] In a gas containing fluorine-containing compound gas, the content of fluorine-containing compound gas can be, for example, 10 to 100% by volume. In this case, the content of inert gas can be, for example, 0 to 90% by volume. In this specification, the content of each gas component is measured, for example, by infrared spectroscopy.

[0050] In 100% by volume of the gas containing a fluorine-containing compound gas, the total content of the fluorine-containing compound gas and the inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume.

[0051] In a gas containing fluorine-containing compound gas, the content of germanium-containing compound gas is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is advantageous in terms of cost. The germanium-containing compound gas is not particularly limited as long as it is a compound gas containing germanium atoms.

[0052] <<Organic Amine Gas>> The organic amine gas is not particularly limited as long as it is an organic amine gas. The organic amine gas may be used alone or in combination of two or more kinds.

[0053] The organic amine may be any of a primary amine, a secondary amine, and a tertiary amine. Of these, secondary amines and tertiary amines are preferred, and tertiary amines are more preferred.

[0054] Examples of the organic amine include trimethylamine, triethylamine, dimethylamine, dimethylethylamine, monomethylamine, diethylmethylamine, monoethylamine, diethylamine, mono-normal propylamine, ethylpropylamine, di-normal propylamine, monoisopropylamine, ethylisopropylamine, diisopropylamine, monobutylamine, dibutylamine, mono-tertiary butylamine, di-tertiary butylamine, pyrrolidine, piperidine, piperazine, pyridine, pyrazine, trifluoromethylamine, 1,1,1-trifluorodimethylamine, perfluorodimethylamine, 2,2,2-trifluoroethylamine, perfluoroethylamine, bis(2,2,2-trifluoroethyl)amine, perfluorodiethylamine, and 3-fluoropyridine. These may be used alone or in combination of two or more. Among these, trimethylamine, triethylamine, dimethylamine, dimethylethylamine, and monomethylamine are preferred, and trimethylamine, triethylamine, dimethylamine, and dimethylethylamine are more preferred.

[0055] The gas containing the organic amine gas is not particularly limited as long as it contains an organic amine gas, but may contain an inert gas other than the organic amine gas. Examples of the inert gas are as described above.

[0056] The content of the organic amine gas in 100% by volume of the gas containing the organic amine gas can be, for example, 10 to 100% by volume. In this case, the content of the inert gas in 100% by volume of the gas containing the organic amine gas can be, for example, 0 to 90% by volume.

[0057] In 100% by volume of the gas containing an organic amine gas, the total content of the organic amine gas and the inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume.

[0058] In a gas containing organic amine gas, the content of germanium-containing compound gas is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is also advantageous in terms of cost. The germanium-containing compound gas is not particularly limited as long as it is a gas of a compound containing germanium atoms.

[0059] The volume ratio (partial pressure ratio) of the fluorine-containing compound gas to the organic amine gas may be 1:0.01 to 1:100, 1:0.05 to 1:10, or 1:0.1 to 1:2. This tends to result in a more favorable outcome of the effects of this disclosure.

[0060] In the dry etching method (1) of this disclosure, it is preferable to contact the film to be etched with a fluorine-containing compound gas and an organic amine gas in a non-plasma environment without creating a plasma state. This is because, if the object to be processed is a semiconductor device substrate, contact with a plasma gas may cause electrical damage to the substrate due to the plasma gas.

[0061] The etching temperature is preferably -50 to 300°C, more preferably -30 to 300°C, and even more preferably 25 to 300°C. For the reason that selectivity for silicon can be further improved, it is particularly preferably 140°C or higher, most preferably 160°C or higher, even more preferably 180°C or higher, even more preferably 220°C or higher, and most preferably 240°C or higher. Furthermore, by setting the etching temperature to 140°C or higher, the deposited film (residue) of organic amines on the surface of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride and / or silicon oxycarbonitride tends to be more favorably reduced, and a better etching shape tends to be obtained.

[0062] [First Dry Etching Method (1)] Below, a first dry etching method (1) of the present disclosure is described, in which a gas containing the fluorine-containing compound gas and a gas containing the organic amine gas are simultaneously brought into contact with the film to be etched. In the first dry etching method (1), gas A, which contains the gas containing the fluorine-containing compound gas and the gas containing the organic amine gas, is brought into contact with the film to be etched. Gas A contains at least the fluorine-containing compound gas and the organic amine gas.

[0063] The fluorine-containing compound gas and organic amine gas contained in gas A are as described above, including in preferred embodiments.

[0064] The amount of fluorine-containing compound gas contained in gas A (the content of fluorine-containing compound gas in 100% by volume of gas A) is preferably 1 to 90% by volume, or may be 1 to 50% by volume, or 10 to 40% by volume. This tends to more suitably obtain the effects of the present disclosure.

[0065] The amount of organic amine gas contained in gas A (the content of organic amine gas in 100% by volume of gas A) is preferably 1 to 50% by volume, and may be 5 to 40% by volume. This tends to more suitably achieve the effects of the present disclosure.

[0066] The volume ratio of fluorine-containing compound gas to organic amine gas contained in gas A is as described above.

[0067] Gas A is not particularly limited as long as it includes fluorine-containing compound gases and organic amine gases, but it may also include inert gases and the like in addition to fluorine-containing compound gases and organic amine gases. The inert gases are as described above.

[0068] In 100% by volume of gas A, the total content of fluorine-containing compound gases and organic amine gases can be, for example, 10 to 100% by volume. In this case, the content of inert gases in 100% by volume of gas A can be, for example, 0 to 90% by volume.

[0069] In 100% by volume of gas A, the total content of fluorine-containing compound gas, organic amine gas, and inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume.

[0070] In 100% by volume of gas A, the content of the germanium-containing compound gas is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is advantageous in terms of cost. The germanium-containing compound gas is not particularly limited as long as it is a gas of a compound containing germanium atoms.

[0071] In the first dry etching method (1), the object to be etched is preferably placed in a processing vessel. In the first dry etching method (1), after contacting the gas A with the film to be etched, the processing vessel is preferably subjected to a reduced pressure state. This is because by-products generated during etching can be removed. The reduced pressure state refers to a state in which the pressure in the processing vessel is lower than the pressure during etching, generally less than 1 Pa.

[0072] The first dry etching method (1) preferably includes a step of replacing the atmosphere in the processing vessel with an inert gas after contacting the gas A with the film to be etched. This is because by-products generated during etching can be removed. The first dry etching method (1) may also include a step of replacing the atmosphere in the processing vessel with an inert gas after a step of reducing the pressure in the processing vessel.

[0073] [Second Dry Etching Method (1)] Next, as a dry etching method (1) of the present disclosure, a second dry etching method (1) will be described, which includes a first step of contacting the film to be etched with gas B containing the organic amine gas and a second step of contacting the film to be etched with gas C containing the fluorine-containing compound gas. Gas B contains at least an organic amine gas, and gas C contains at least a fluorine-containing compound gas. In the first step, the organic amine is adsorbed onto the surface of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and / or silicon oxycarbonitride to form a protective layer. Thereafter, in the second step, silicon not having a protective layer formed thereon is selectively etched by the fluorine-containing compound. In this way, the synergistic effect of the fluorine-containing compound gas and the organic amine gas improves selectivity to silicon, enabling selective etching of silicon.

[0074] The organic amine gas contained in gas B and the fluorine-containing compound gas contained in gas C are as described above, including preferred embodiments.

[0075] Gas B is not particularly limited as long as it contains an organic amine gas, but may also contain an inert gas or the like in addition to the organic amine gas. Gas C is not particularly limited as long as it contains a fluorine-containing compound gas, but may also contain an inert gas or the like in addition to the fluorine-containing compound gas. Examples of inert gases are as described above.

[0076] The content of the organic amine gas in 100% by volume of gas B can be, for example, 10 to 100% by volume. In this case, the content of the inert gas in 100% by volume of gas B can be, for example, 0 to 90% by volume. In 100% by volume of gas C, the content of the fluorine-containing compound gas can be, for example, 10 to 100% by volume. In this case, the content of the inert gas in 100% by volume of gas C can be, for example, 0 to 90% by volume.

[0077] In 100% by volume of Gas B, the total content of the organic amine gas and the inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume. In 100% by volume of Gas C, the total content of the fluorine-containing compound gas and the inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume. The volume ratio of the fluorine-containing compound gas contained in Gas C to the organic amine gas contained in Gas B is as described above.

[0078] The content of the germanium-containing compound gas in 100% by volume of gas B is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is advantageous in terms of cost. The content of the germanium-containing compound gas in 100% by volume of gas C is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is advantageous in terms of cost. The germanium-containing compound gas is not particularly limited as long as it is a gas of a compound containing germanium atoms.

[0079] In the second dry etching method (1), it is preferable to place the object to be etched in a processing vessel. In the second dry etching method (1), it is preferable to perform a step of reducing the pressure inside the processing vessel after contacting Gas B and Gas C with the film to be etched. This is because by-products generated during etching can be removed.

[0080] The second dry etching method (1) preferably includes a step of substituting an inert gas for the atmosphere in the processing vessel after contacting Gas B and Gas C with the film to be etched. This is because by-products generated during etching can be removed. The second dry etching method (1) may include a step of substituting an inert gas for the atmosphere in the processing vessel after a step of reducing the pressure in the processing vessel.

[0081] In the second dry etching method (1) of the present disclosure, the above steps may be repeated multiple times to repeatedly etch the film to be etched. Since it is possible to etch the film to a certain thickness in one etching cycle, by specifying the number of cycles, it is possible to precisely etch a layer to a desired thickness.

[0082] (First Dry Etching Method (1) Using Etching Apparatus) The first dry etching method (1) can be realized, for example, by using an etching apparatus shown in FIG. 1. FIG. 1 is a schematic diagram of an etching apparatus used in the examples of the present disclosure. Below, the first dry etching method (1) will be specifically described using the etching apparatus of FIG. 1 as an example. The etching apparatus of the present disclosure includes a mounting table on which an object to be processed is placed, a fluorine-containing compound gas supply unit that supplies a gas containing a fluorine-containing compound gas to the object to be processed, and an organic amine gas supply unit that supplies a gas containing an organic amine gas to the object to be processed. The etching apparatus of the present disclosure may further include an inert gas supply unit that supplies an inert gas.

[0083] In the first dry etching method (1), a gas A containing a gas containing a fluorine-containing compound gas (also simply referred to as a fluorine-containing compound gas) and a gas containing an organic amine gas (also simply referred to as an organic amine gas) is brought into contact with a film to be etched. First, the workpiece 10 on which the film to be etched has been formed is placed on the mounting portion 111 in the processing vessel 110. Next, the interior of the processing vessel 110, the pipe 121, the pipes 131 and 132, the pipes 141 and 142, the pipes 151 and 152, the liquid nitrogen trap 194, and the pipe 191 are evacuated to a predetermined pressure using a vacuum pump 193, and then the temperature of the workpiece 10 is adjusted by heating and / or cooling using a temperature adjustment means 190. Note that, although the temperature adjustment means 190 is provided outside the processing vessel 110 in FIG. 1 , it may be provided inside the mounting portion 111, or it may be provided both inside the mounting portion 111 and outside the processing vessel 110.

[0084] When the workpiece 10 reaches a predetermined temperature, the fluorine-containing compound gas supply unit 130 and the organic amine gas supply unit 140 supply a fluorine-containing compound gas and an organic amine gas at predetermined flow rates to the pipe 121. The fluorine-containing compound gas supply unit 130 adjusts the supply amount using valves V1 and V2 and a flow rate adjustment unit MFC1, and supplies the fluorine-containing compound gas from pipes 131 and 132 to the pipe 121. The organic amine gas supply unit 140 adjusts the supply amount using valves V3 and V4 and a flow rate adjustment unit MFC2, and supplies the organic amine gas from pipes 141 and 142 to the pipe 121.

[0085] Alternatively, the inert gas may be supplied at a predetermined flow rate from the inert gas supply unit 150 to the pipe 121. The inert gas supply unit 150 adjusts the supply amount using valves V5 and V6 and a flow rate adjustment unit MFC3, and supplies the inert gas from pipes 151 and 152 to the pipe 121.

[0086] In FIG. 1, PI1 and PI2 are pressure gauges, and the flow rate adjusting means and valves are controlled based on the indicated values.

[0087] A fluorine-containing compound gas and an organic amine gas are mixed in a predetermined composition and supplied to the processing container 110. While introducing the mixed gas into the processing container 110, the pressure inside the processing container 110 is controlled to a predetermined level. Etching is performed by reacting the gas with the film to be etched for a predetermined time. In this first dry etching method (1), etching is possible without a plasma state, and gas excitation with plasma or the like is not required during etching. The gas flow rate can be appropriately set based on the volume and pressure of the processing container.

[0088] Note that etching accompanied by a plasma state refers to a process in which, for example, a gas of about 0.01 to 1.33 kPa is introduced into the reactor, and high-frequency power is applied to an external coil or counter electrode to generate a low-temperature gas plasma in the reactor, and etching is performed by activating chemical species such as ions and radicals that are formed within it. In the dry etching method (1) of this disclosure, the gas is brought into contact without the formation of a plasma state, and dry etching can be performed without generating the gas plasma described above.

[0089] After etching is complete, heating or cooling by the temperature control means 190 is stopped and the temperature is lowered or raised, and the vacuum pump 193 is stopped and the vacuum is released by replacing it with an inert gas. As described above, silicon can be selectively etched by the dry etching method (1) using the etching apparatus.

[0090] (Etching conditions in the first dry etching method (1)) In the first dry etching method (1), the temperature of the film to be etched during etching is the same as the etching temperature described above. The surface temperature of the workpiece is substantially equal to the temperature of the film to be etched, but during the etching reaction, the surface temperature of the workpiece and the temperature of the film to be etched may rise due to the heat of reaction. In this disclosure, it is preferable that at least the etching temperature, i.e., the temperature inside the processing container or the temperature of the mounting section on which the workpiece is placed, is within the above temperature range.

[0091] The pressure inside the processing vessel during etching is not particularly limited, but is usually 1 Pa to 101.3 kPa, preferably 1 Pa to 13.3 kPa, more preferably 1 Pa to 1.33 kPa, and even more preferably 1 Pa to 120 Pa.

[0092] The etching time is not particularly limited, but is preferably within 60 minutes in consideration of the efficiency of the semiconductor device manufacturing process. Here, the etching time refers to the time from when a gas is introduced into a processing vessel in which a workpiece is placed until the mixed gas in the processing vessel is exhausted by a vacuum pump or the like to complete the etching process.

[0093] (Second dry etching method (1) using an etching apparatus) The second dry etching method (1) can be realized, for example, by using the etching apparatus shown in Fig. 1. In the following, the second dry etching method (1) will be specifically described using the etching apparatus of Fig. 1 as an example.

[0094] In the second dry etching method (1), the gas B containing the organic amine gas is brought into contact with the film to be etched, and then the gas C containing the fluorine-containing compound gas is brought into contact with the film to be etched.

[0095] First, the object 10 to be processed on which a film to be etched is formed is placed on the mounting portion 111 in the processing vessel 110. Next, the inside of the processing vessel 110, the pipe 121, the pipes 131 and 132, the pipes 141 and 142, the pipes 151 and 152, the liquid nitrogen trap 194, and the pipe 191 are evacuated to a predetermined pressure by the vacuum pump 193, and then the temperature of the object 10 to be processed is adjusted by the temperature adjustment means 190.

[0096] Once the object to be treated 10 reaches a predetermined temperature, first, organic amine gas, which is gas B, is supplied to the piping 121 from the organic amine gas supply unit 140 at a predetermined flow rate. Alternatively, inert gas may be supplied to the piping 121 from the inert gas supply unit 150 at a predetermined flow rate. While introducing the organic amine gas, which is gas B, into the processing container 110, the pressure inside the processing container 110 is controlled to a predetermined level. By introducing gas B into the processing container 110 for a predetermined time, the organic amine is adsorbed onto silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbonitride and / or silicon oxycarbonitride.

[0097] After evacuating gas B, which contains organic amine gas, gas C, a fluorine-containing compound gas, is supplied to piping 121 at a predetermined flow rate from the fluorine-containing compound gas supply unit 130. Alternatively, inert gas may be supplied to piping 121 at a predetermined flow rate from the inert gas supply unit 150. While introducing gas C, the fluorine-containing compound gas, into the processing container 110, the pressure inside the processing container 110 is controlled to a predetermined level. By introducing gas C into the processing container 110 for a predetermined time, silicon can be selectively etched.

[0098] In the second dry etching method (1) of this disclosure, the process of introducing an organic amine gas into the processing vessel 110 in a first step and introducing a fluorine-containing compound gas into the processing vessel 110 in a second step is repeated multiple times, with each step comprising one cycle. In the second dry etching method (1) of this disclosure, the thickness of the film to be etched that can be etched in one cycle can be controlled by setting the etching conditions for one cycle to predetermined conditions. Therefore, by setting the thickness of the film to be etched that can be etched in one cycle to a thin thickness, the thickness to be etched can be precisely controlled. In the second dry etching method (1) of this disclosure, it is preferable to perform the second step after performing the first step. It is also preferable to perform a step of reducing the pressure inside the processing vessel or replacing the inside of the processing vessel with an inert gas after each cycle. It is also possible to perform a step of reducing the pressure inside the processing vessel or replacing the inside of the processing vessel with an inert gas after performing the first step.

[0099] In addition, the second dry etching method (1) also allows for plasmaless etching without the use of a plasma state, and does not require excitation of the etching gas with plasma or the like during etching. The flow rates of the fluorine-containing compound gas and the organic amine gas can be appropriately set based on the volume and pressure of the processing vessel. The volume ratio of the fluorine-containing compound gas contained in gas C to the organic amine gas contained in gas B is the same as the volume ratio of the fluorine-containing compound gas and the organic amine gas contained in gas A, as described above.

[0100] Thus, in the second dry etching method (1) using the etching apparatus described above, the gas can be brought into contact with the film to be etched without generating a plasma state, and dry etching can be performed without generating the gas plasma described above.

[0101] After the etching process is completed, the heating or cooling by the temperature control means 190 is stopped and the temperature is lowered or raised, and the vacuum pump 193 is stopped and the vacuum is released by replacing it with an inert gas. In this way, the film to be etched can be etched.

[0102] (Etching conditions in the second dry etching method (1)) In the second dry etching method (1), the temperature of the film to be etched when performing the first step and the temperature of the film to be etched when performing the second step are the same as the etching temperature described above.

[0103] Furthermore, when Gas B is brought into contact with the film to be etched, and when Gas C is brought into contact with the film to be etched, the pressure inside the processing vessel in which the object to be processed on which the film to be etched has been formed is placed is not particularly limited, but is usually 1 Pa to 101.3 kPa, preferably 1 Pa to 13.3 kPa, more preferably 1 Pa to 1.33 kPa, and even more preferably 1 Pa to 120 Pa.

[0104] The processing times in the first and second steps are not particularly limited, but the processing time in one cycle of the first step is preferably 60 minutes or less, and the processing time in one cycle of the second step is preferably 60 minutes or less. Here, the processing time of the etching step refers to the time from introducing gas into the processing container in which the workpiece is placed until the gas in the processing container is exhausted by a vacuum pump or the like to complete the etching process.

[0105] <Method for Manufacturing Semiconductor Devices (1)> The dry etching method (1) of the present disclosure described above can be used as an etching method for forming a predetermined pattern on a semiconductor device. A semiconductor device can be manufactured by selectively etching silicon on a substrate using the dry etching method (1) of the present disclosure. The method for manufacturing semiconductor devices (1) of the present disclosure is characterized by including a step of applying the dry etching method (1) of the present disclosure to silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride to selectively etch silicon. The step of supplying a gas containing a fluorine-containing compound gas and a gas containing an organic amine gas to the above film, etc., and etching can be carried out by the dry etching method (1) of the present disclosure described above.

[0106] <Etching Gas Composition> The etching gas composition of the present disclosure contains a fluorine-containing compound gas and an organic amine gas. The etching gas composition of the present disclosure is similar to Gas A described in the first dry etching method (1), including preferred aspects thereof.

[0107] <Dry Etching Method (2)> The dry etching method (2) of the present disclosure is a dry etching method that selectively uses, as desired, a step of selectively etching silicon germanium from silicon and silicon germanium using a gas D containing a fluorine-containing compound gas but not an organic amine gas, and a step of selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas. This allows the etching target to be changed by the simple operation of changing the gas flow rate. For example, the etching target can be changed by adjusting the flow rate of the organic amine gas. Furthermore, when performing the step of selectively etching silicon, the same effects as those of the dry etching method (1) of the present disclosure can be achieved.

[0108] The step of selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas may be performed in the same manner as in the dry etching method (1) of the present disclosure. Of course, as in the first dry etching method (1), the gas containing the fluorine-containing compound gas and the gas containing the organic amine gas may be simultaneously brought into contact with the film to be etched, or as in the second dry etching method (1), the method may include a first step of bringing a gas B containing the organic amine gas into contact with the film to be etched and a second step of bringing a gas C containing the fluorine-containing compound gas into contact with the film to be etched.

[0109] Gas D contains a fluorine-containing compound gas but does not contain an organic amine gas. Here, the organic amine gas and the fluorine-containing compound gas are as described in the dry etching method (1) of this disclosure, including preferred embodiments.

[0110] Gas D is said to be free of organic amine gas if, in 100% by volume of gas D, the content of organic amine gas is preferably 0.1% by volume or less, more preferably 0.01% by volume or less, and even more preferably 0.00% by volume.

[0111] Gas D is not particularly limited as long as it contains a fluorine-containing compound gas and does not contain an organic amine gas, but it may also contain inert gases other than fluorine-containing compound gases. The inert gases are as described above.

[0112] The content of the fluorine-containing compound gas in 100% by volume of gas D can be, for example, 10 to 100% by volume, and the content of the inert gas in 100% by volume of gas D can be, for example, 0 to 90% by volume.

[0113] In 100% by volume of gas D, the total content of the fluorine-containing compound gas and the inert gas is preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and may be 100% by volume.

[0114] In 100% by volume of gas D, the content of the germanium-containing compound gas is preferably 1% by volume or less, more preferably 0.1% by volume or less, even more preferably 0.01% by volume or less, and particularly preferably 0.00% by volume. This is advantageous in terms of cost. The germanium-containing compound gas is not particularly limited as long as it is a gas of a compound containing germanium atoms.

[0115] The step of selectively etching silicon germanium from silicon and silicon germanium using Gas D may be performed in the same manner as in the dry etching method (1) of the present disclosure, except that Gas D is used. This allows silicon germanium to be selectively etched from silicon and silicon germanium.

[0116] <Method for manufacturing a semiconductor device (2)> The dry etching method (2) of the present disclosure described above can be used as an etching method for forming a predetermined pattern on a semiconductor device. A semiconductor device can be manufactured by selectively etching silicon and / or silicon germanium on a substrate using the dry etching method (2) of the present disclosure. The method for manufacturing a semiconductor device (2) of the present disclosure is characterized by including a step of selectively etching silicon and / or silicon germanium by applying the dry etching method (2) of the present disclosure to silicon and silicon germanium. The etching step can be performed using the dry etching method (2) of the present disclosure described above.

[0117] In the dry etching methods (1) and (2) of the present disclosure, any of the following methods may be excluded: (a) A method for etching a substrate, the method comprising: a. providing the substrate in a reaction chamber, the substrate including a target material to be partially or completely removed from the substrate during etching; b. supplying a gas mixture into the reaction chamber and exposing the substrate to the gas mixture while the pressure of the reaction chamber is about 0.2 to 10 Torr, the gas mixture being in a vapor phase and including: i. a halogen source, ii. an organic solvent and / or water, iii. an additive, and iv. a carrier gas; and c. supplying thermal energy to the reaction chamber to induce a reaction that partially or completely etches the target material from the substrate, wherein the substrate is not exposed to plasma during etching. (b) An etching method for etching a silicon-containing film provided on a substrate by supplying an etching gas to the substrate, the etching method comprising: an amine gas supplying step of supplying an amine gas to the substrate on which the silicon-containing film, a porous film, and a non-etching film that is etchable by the etching gas are provided adjacent to each other in this order, and causing the amine to be adsorbed onto pore walls that form pores in the porous film; and an etching gas supplying step of supplying an etching gas for etching the silicon-containing film to the substrate on which the amine is adsorbed onto the pore walls.

[0118] In the etching apparatus of the present disclosure, any of the following apparatus may be excluded: (a) an apparatus for etching a substrate, the apparatus comprising: a. a reaction chamber configured to withstand an internal pressure of about 0.2 to 10 Torr; b. a substrate support configured to support the substrate during etching; c. an inlet for introducing a gas mixture in the gas phase into the reaction chamber; d. an outlet for removing gaseous chemical species from the reaction chamber; and e. a controller configured to carry out the following method: A method for etching a substrate, the method comprising: a. providing the substrate in a reaction chamber, the substrate comprising a target material to be partially or completely removed from the substrate during etching; b. supplying a gas mixture into the reaction chamber and exposing the substrate to the gas mixture while the pressure in the reaction chamber is about 0.2 to 10 Torr, the gas mixture being in the vapor phase, i. a halogen source, ii. an organic solvent and / or water, iii. an additive, and iv. and c) supplying a gas mixture including a carrier gas and a target material to the reaction chamber; and c) supplying thermal energy to the reaction chamber to induce a reaction that partially or completely etches the target material from the substrate, wherein the substrate is not exposed to plasma during etching. (b) An etching apparatus for etching a silicon-containing film provided on a substrate by supplying an etching gas to the substrate, the etching apparatus comprising: a processing vessel; a mounting unit provided in the processing vessel for mounting the substrate, the substrate having the silicon-containing film, a porous film, and a non-etching film that is etchable by the etching gas, arranged adjacent to each other in this order; an amine gas supply unit that supplies an amine gas to the substrate and causes amine to adsorb onto pore walls that form pores in the porous film; and an etching gas supply unit that supplies an etching gas for etching the silicon-containing film to the substrate with amine adsorbed onto the pore walls.

[0119] Examples of the present disclosure will be described below along with comparative examples, but the present disclosure is not limited to the following examples. First, as substrates to be processed, a silicon wafer on which a polysilicon film is formed, a silicon wafer on which a SiGe film is formed, a silicon wafer on which a SiN film is formed, and a SiO ２ A silicon wafer on which a film was formed was prepared. The film thickness of the substrate to be treated was measured before and after etching using a spectroscopic ellipsometer (manufactured by Nippon Semilab Co., Ltd., product name: SE-2000), and the etching rate was calculated based on the amount of etching calculated from the measurement results.

[0120] Example 1 The etching apparatus 100 shown in FIG. 1 was used. First, a substrate to be processed was placed on a mounting table in a processing chamber, and after the processing chamber was fully evacuated, the temperature of the mounting table was set to 40° C. The temperature of the substrate was the same as that of the mounting table, which was essentially equal to the temperature of the film to be etched. Next, N 2 was introduced into the processing chamber. ２ The gas was passed through the processing vessel to dry it thoroughly. Then, as shown in Table 1, an organic amine gas, a fluorine-containing compound gas, and an additive gas were passed through the processing vessel for 3 minutes. Finally, the processing vessel was evacuated, and N ２ The substrates to be treated were taken out after the gas replacement. The results are shown in Table 1. The substrates to be treated were silicon wafers with a polysilicon film formed thereon, silicon wafers with a SiGe film formed thereon, silicon wafers with a SiN film formed thereon, and silicon wafers with a SiO ２ All silicon wafers with the films formed on them were placed in the same processing container, and the etching process was performed simultaneously.

[0121] [Examples 2 to 18] and [Comparative Examples 1 to 3] Tests were carried out under the same conditions as in Example 1, except that the conditions were changed as shown in Table 1. The results are shown in Table 1.

[0122]

[0123] Table 1 shows that a fluorine-containing compound gas and an organic amine gas can selectively etch silicon from at least one selected from the group consisting of silicon and silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride. On the other hand, in Comparative Examples 1 and 2, in which only a fluorine-containing compound gas was used without an organic amine gas, silicon germanium was selectively etched. Furthermore, in Comparative Example 3, in which ammonia was used instead of an organic amine as the amine, the silicon selective etching was inferior to the Examples. Furthermore, Table 1 also shows that the etching target can be changed by simply changing the gas flow rate using a dry etching method in which a process of selectively etching silicon germanium from silicon and silicon germanium using gas D containing a fluorine-containing compound gas but not an organic amine gas, and a process of selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas are selectively used as desired. In Examples in which the etching temperature was 140° C. or higher, SiGe, SiN, SiO ２ It was also confirmed that the amount of residue on each surface was small and very clean etching was possible.

[0124] REFERENCE SIGNS LIST 10 Object to be processed 100 Etching apparatus 110 Processing container 111 Mounting section 121 Pipe 130 Fluorine-containing compound gas supply section 131, 132 Pipe 140 Organic amine gas supply section 141, 142 Pipe 150 Inert gas supply section 151, 152 Pipe 190 Temperature adjustment means 191, 192 Pipe 193 Vacuum pump 194 Liquid nitrogen trap MFC1, MFC2, MFC3 Flow rate adjustment means PI1, PI2 Pressure gauge V1, V2, V3, V4, V5, V6, V7, V8 Valve

Claims

1. A dry etching method in which silicon and at least one material selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride are selectively etched using a fluorine-containing compound gas and an organic amine gas.

2. The fluorine-containing compound is IF ７ , IF ５ , BrF ５ , BrF ３ , ClF ３ , ClF, MoF ６ and W.F. ６ 2. The dry etching method according to claim 1, wherein the etching agent is at least one selected from the group consisting of:

3. The dry etching method according to claim 1, wherein the organic amine is at least one selected from the group consisting of trimethylamine, triethylamine, dimethylamine, dimethylethylamine, monomethylamine, diethylmethylamine, monoethylamine, diethylamine, mono-normal propylamine, ethylpropylamine, di-normal propylamine, monoisopropylamine, ethylisopropylamine, diisopropylamine, monobutylamine, dibutylamine, mono-tertiary butylamine, di-tertiary butylamine, pyrrolidine, piperidine, piperazine, pyridine, pyrazine, trifluoromethylamine, 1,1,1-trifluorodimethylamine, perfluorodimethylamine, 2,2,2-trifluoroethylamine, perfluoroethylamine, bis(2,2,2-trifluoroethyl)amine, perfluorodiethylamine, and 3-fluoropyridine.

4. The dry etching method according to claim 1, wherein silicon is selectively etched from at least one material selected from the group consisting of silicon germanium, silicon oxide and silicon nitride.

5. The dry etching method according to claim 1, wherein the etching temperature is -50 to 300°C.

6. The dry etching method according to claim 1, wherein the etching temperature is 140 to 300°C.

7. The dry etching method according to claim 1, wherein the etching pressure is 1 Pa to 13.3 kPa.

8. The dry etching method according to claim 1, wherein etching is performed without using a plasma state.

9. The dry etching method according to claim 1, wherein the silicon is one of a polysilicon film formed on a substrate, an amorphous silicon film formed on a substrate, an epitaxially grown silicon film formed on a substrate, and a single crystal silicon substrate.

10. The dry etching method according to claim 1, wherein gas A containing the fluorine-containing compound gas and the organic amine gas is brought into contact with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride and silicon oxycarbonitride.

11. The dry etching method according to claim 10, wherein the amount of said fluorine-containing compound gas contained in said gas A is 1 to 90% by volume.

12. The dry etching method according to claim 10, wherein the amount of said organic amine gas contained in said gas A is 1 to 50% by volume.

13. A dry etching method according to claim 10, wherein the volume ratio of the fluorine-containing compound gas to the organic amine gas contained in gas A is fluorine-containing compound gas:organic amine gas=1:0.01 to 1:

100.

14. The dry etching method according to claim 1, comprising: a first step of contacting gas B containing the organic amine gas with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride; and a second step of contacting gas C containing the fluorine-containing compound gas with silicon and at least one selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

15. A dry etching method in which a process for selectively etching silicon germanium from silicon and silicon germanium using gas D containing a fluorine-containing compound gas but not an organic amine gas, and a process for selectively etching silicon from silicon and silicon germanium using a fluorine-containing compound gas and an organic amine gas are selectively used as desired.

16. A method for manufacturing a semiconductor device, comprising the step of selectively etching silicon by applying the dry etching method according to any one of claims 1 to 14 to silicon and at least one material selected from the group consisting of silicon germanium, germanium, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbonitride, and silicon oxycarbonitride.

17. A method for manufacturing a semiconductor device, comprising the step of selectively etching silicon and / or silicon germanium by applying the dry etching method of claim 15 to silicon and silicon germanium.

18. An etching apparatus comprising: a mounting table for mounting an object to be processed; a fluorine-containing compound gas supply unit for supplying a gas containing a fluorine-containing compound gas to the object to be processed; and an organic amine gas supply unit for supplying a gas containing an organic amine gas to the object to be processed.

19. An etching gas composition comprising a fluorine-containing compound gas and an organic amine gas.

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