Substrate processing method, semiconductor device manufacturing method, and processing device

Abstract

Provided are a substrate processing method, a semiconductor device manufacturing method, and a processing device capable of reducing metal contamination on a substrate. The present invention relates to a method for processing a substrate by means of at least one gas (first gas) selected from the group consisting of IF7, IF5, BrF5, BrF3, MoF6, GeF4, ClF, and ClF3, and at least one gas (second gas) selected from the group consisting of F2 and HF.

Description

Substrate processing method, semiconductor device manufacturing method and processing apparatus

[0001] The present disclosure relates to a processing method for processing a substrate, a method for manufacturing a semiconductor device, and a processing apparatus.

[0002] In the manufacturing process of semiconductor devices, a method of etching a polysilicon film with a fluorine-based halogen gas (Patent Document 1), GeF ４ A method for forming a SiGe film using a gas (Patent Document 2), MoF ６ A method of forming a Mo film using a gas (Patent Document 3) is known.

[0003] International Publication No. 2013 / 027653 JP 10-083964 JP 3-58423

[0004] IF ７ , MoF ６ , GeF ４ In processes using fluorine-containing gases such as those described above, there is a concern that metal contamination such as Fe, Cr, Mn, Co, Ti, Mo, Cu, and Ni may occur on the substrate after gas processing, and there is room for further improvement. This is presumably because fluorine-containing gases have relatively high oxidizing properties.

[0005] The present disclosure aims to solve the above-mentioned problems and provide a substrate processing method, a semiconductor device manufacturing method, and a processing apparatus that can reduce metal contamination on a substrate.

[0006] As a result of extensive investigation, the present inventors have found that IF ７ , MoF ６ , GeF ４ Even if metal contamination occurs on the substrate in a process using a fluorine-containing gas such as F ２ and HF, and have found that metal contamination on a substrate can be reduced by using at least one gas selected from the group consisting of HCl, HCl, and HF.

[0007] That is, the present disclosure (1) is IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４, ClF and ClF ３ at least one gas (first gas) selected from the group consisting of: ２ and HF, and at least one gas (second gas) selected from the group consisting of

[0008] The present disclosure (2) is a method for manufacturing a semiconductor device, ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ and ClF, wherein the gas is at least one selected from the group consisting of:

[0009] The present disclosure (3) is a method for manufacturing a gas turbine engine, ７ , BrF ５ and GeF ４ The present disclosure relates to a processing method according to (1), wherein the gas is at least one gas selected from the group consisting of:

[0010] The present disclosure (4) is a method for manufacturing a semiconductor device, ７ The present disclosure relates to a processing method according to (1).

[0011] The present disclosure (5) relates to the processing method according to any one of the present disclosures (1) to (4), in which the temperature during processing of the substrate is 0 to 300°C.

[0012] The present disclosure (6) relates to the processing method according to any one of the present disclosures (1) to (5), in which a gas A containing the first gas and the second gas is brought into contact with a substrate.

[0013] The present disclosure (7) relates to the processing method according to the present disclosure (6), wherein the sum of the partial pressure of the first gas and the partial pressure of the second gas in gas A is 0.01 to 1333 Pa.

[0014] The present disclosure (8) relates to the processing method according to the present disclosure (6) or (7), wherein the ratio of the partial pressure of the first gas to the partial pressure of the second gas in gas A (partial pressure of the first gas / partial pressure of the second gas) is 0.001 to 100.

[0015] The present disclosure (9) relates to the processing method according to the present disclosure (6) or (7), wherein the ratio of the partial pressure of the first gas to the partial pressure of the second gas in gas A (partial pressure of the first gas / partial pressure of the second gas) is 0.01 or more and less than 1.0.

[0016] The present disclosure (10) is a method for manufacturing a gas turbine engine, ７ , BrF ５ and GeF ４ and wherein the ratio of the "sum of the partial pressure of the first gas and the partial pressure of the second gas" to the total pressure in Gas A ("sum of the partial pressure of the first gas and the partial pressure of the second gas" / total pressure) is 0.1 to 1.0.

[0017] The present disclosure (11) relates to the processing method according to any one of the present disclosures (1) to (5), which includes a first step of contacting a gas B containing the first gas with a substrate, and a second step of contacting a gas C containing the second gas with the substrate.

[0018] The present disclosure (12) relates to the processing method according to the present disclosure (11), wherein the partial pressure of the first gas in gas B is 0.01 to 1333 Pa.

[0019] The present disclosure (13) relates to the processing method according to the present disclosure (11) or (12), in which the partial pressure of the second gas in the gas C is 0.01 to 13,333 Pa.

[0020] The present disclosure (14) is directed to a method for treating a substrate in which the concentration of at least one metal atom selected from the group consisting of chromium, titanium, and molybdenum remaining on the surface of the treated substrate is 1×10 １１ atoms / cm ２ The present disclosure relates to a processing method according to any one of (1) to (13) below.

[0021] The present disclosure (15) relates to a method for manufacturing a semiconductor device, including a step of processing a substrate by applying the processing method according to any one of the present disclosures (1) to (14) to the substrate.

[0022] The present disclosure (16) provides a mounting table for mounting an object to be processed, and an IF for the object to be processed. ７ , IF ５ , BrF５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ a first gas supply unit that supplies at least one gas selected from the group consisting of F ２ and a second gas supply unit that supplies at least one gas selected from the group consisting of fluorine, fluorine, and HF.

[0023] The processing method for processing a substrate according to the present disclosure includes IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of F ２ and HF, the substrate is treated with at least one gas selected from the group consisting of HCl, HCl, and HF, and therefore metal contamination on the substrate can be reduced.

[0024] The method for manufacturing a semiconductor device according to the present disclosure includes a step of processing a substrate by applying the processing method according to the present disclosure to the substrate. Because the method for manufacturing a semiconductor device according to the present disclosure includes a step of processing a substrate by applying the processing method according to the present disclosure to the substrate, metal contamination on the substrate can be reduced, and high-quality semiconductor devices can be manufactured.

[0025] The processing apparatus of the present disclosure includes a stage on which a processing object is placed, and an IF for the processing object. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ a first gas supply unit that supplies at least one gas selected from the group consisting of: ２ and a second gas supply unit that supplies at least one gas selected from the group consisting of HF and HF, thereby reducing metal contamination on the substrate.

[0026] FIG. 1 is a schematic diagram of an example of a processing apparatus of the present disclosure.

[0027] The present disclosure will be described in detail below, but the following description of the constituent elements is an example of an embodiment of the present disclosure, and the present disclosure is not limited to these specific details. Various modifications can be made within the scope of the gist of the present disclosure.

[0028] 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."

[0029] <Substrate Processing Method> The substrate processing method of the present disclosure is an IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of F ２ and HF, thereby reducing metal (particularly Cr, Ti, and Mo) contamination on the substrate and reducing metal contamination of semiconductor elements.

[0030] The reason why the above-mentioned effects are obtained is not entirely clear, but it is presumed to be due to the following mechanism. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３By using at least one gas selected from the group consisting of, there is a relatively high probability that metal contamination on the substrate will occur due to metals originally contained in these gases or due to metals migrating from the surfaces of pipes, chambers, etc. into the gas because these gases are relatively highly oxidizing gases. Materials used for pipes, chambers, etc. include nickel, nickel-based alloys such as Hastelloy (registered trademark), Monel (registered trademark), or Inconel (registered trademark), aluminum, aluminum alloys, and stainless steel. Fluorine-containing gases may react with metal components contained in these materials, causing the metal components to migrate into the gas as gas or fine particles. On the other hand, when metal contamination occurs on the substrate, F ２ By bringing at least one gas selected from the group consisting of HF and HF into contact with the metal on the substrate, a reaction product that is easily volatilized is produced, and as a result, the metal on the substrate is removed, thereby reducing metal contamination on the substrate.

[0031] The present disclosure may be combined with conventional techniques such as reducing metal impurities contained in gases and passivating the metal surfaces of piping and chambers.

[0032] The substrate is not particularly limited, but is preferably a semiconductor device substrate, and examples thereof include a silicon substrate, a compound semiconductor substrate, a quartz substrate, a glass substrate, etc. Among these, a silicon substrate (silicon wafer) is preferred.

[0033] The surface of the substrate may be formed with a silicon-containing film, a germanium-containing film, a film containing a metal nitride, a metal wiring film, a film containing a metal oxide, or the like. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of can be used as, for example, an etching gas, and therefore it is also preferable that a film that can be etched by these gases (specifically, a silicon-containing film or a germanium-containing film) is formed on the surface of the substrate.

[0034] The silicon-containing film is not particularly limited as long as it is a film containing silicon, and examples thereof include simple Si, a film containing at least Si and O (preferably a film containing at least Si and O but not N), a film containing at least Si and N, etc. These may be used alone or in combination of two or more.

[0035] As a film containing at least Si and O (preferably a film containing at least Si and O and not containing N), silicon oxide (SiO, where SiO does not indicate the stoichiometric ratio of each element, but refers to a film containing silicon atoms and oxygen atoms. For example, SiO ｘ (x is 1 or more and 2 or less) and SiO ２ In this specification, a film containing at least Si and O but not N means that the N content in 100% by mass of the film is 1% by mass or less, preferably 0.1% by mass or less, more preferably 0.01% by mass or less, and even more preferably 0.00% by mass.

[0036] As a film containing at least Si and N, silicon nitride (SiN, where SiN does not indicate the stoichiometric ratio of each element, but refers to a film containing silicon atoms and nitrogen atoms. For example, SiN ｘ (x is 0.3 or more and 9 or less) and Si ３ N ４ ) film, silicon oxide carbonitride (SiOCN, where SiOCN does not indicate the stoichiometric ratio of each element, but refers to a film containing silicon atoms, oxygen atoms, carbon atoms, and nitrogen atoms.) film, silicon oxynitride (SiON, where SiON does not indicate the stoichiometric ratio of each element, but refers to a film containing silicon atoms, oxygen atoms, and nitrogen atoms. For example, Si ４ O ｘ N ｙ (x is 3 or more and 6 or less, y is 2 or more and 4 or less) or Si ４ O ５ N ３ ) film, and silicon carbide nitride (SiCN; here, SiCN does not indicate the stoichiometric ratio of each element, but refers to a film containing silicon atoms, carbon atoms, and nitrogen atoms. For example, a material containing 20 to 50 atomic % of silicon, 5 to 30 atomic % of carbon, and 10 to 30 atomic % of nitrogen) film.

[0037] The silicon-containing film is preferably a film containing at least Si and O (preferably a film containing at least Si and O and not containing N), more preferably a silicon oxide film, and more preferably SiO ２ A membrane is more preferred.

[0038] In the processing method of the present disclosure, IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of F ２ and at least one gas selected from the group consisting of HF.

[0039] <<IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas (first gas) selected from the group consisting of >> IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ As the at least one gas (first gas) selected from the group consisting of ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ and ClF, and preferably at least one gas selected from the group consisting of IF ７ , BrF ５ and GeF ４ It is more preferable that the gas is at least one selected from the group consisting of IF ７ The first gas may be used alone or in combination of two or more kinds.

[0040] IF ７ , IF ５ , BrF５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas (first gas) selected from the group consisting of the above is used for etching, film formation, surface fluorination treatment, etc.

[0041] IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ The gas containing at least one gas (first gas) selected from the group consisting of is not particularly limited as long as it contains the first gas, but may also contain an inert gas or the like in addition to the first gas.

[0042] Examples of inert gases include Ar and N ２ , He, Ne, Kr, etc. These may be used alone or in combination of two or more.

[0043] The content of the first gas in 100% by volume of the gas containing the first 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 first 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.

[0044] In 100% by volume of the gas containing the first gas, the total content of the first 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.

[0045] <<F ２ and at least one gas (second gas) selected from the group consisting of F ２ and HF, and the at least one gas (second gas) selected from the group consisting of F ２ The second gas may be used alone or in combination of two or more kinds.

[0046] F ２The gas containing at least one gas (second gas) selected from the group consisting of HF and HF is not particularly limited as long as it contains the second gas, but may also contain an inert gas in addition to the second gas. Examples of the inert gas are as described above.

[0047] The content of the second gas in 100% by volume of the gas containing the second 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 second gas can be, for example, 0 to 90% by volume.

[0048] In 100% by volume of the gas containing the second gas, the total content of the second 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.

[0049] In the processing method of the present disclosure, it is preferable to bring the first gas and the second gas into contact with the substrate in a non-plasma environment without creating a plasma state, because if the object to be processed is a semiconductor device substrate, contact with the plasma gas may cause electrical damage to the substrate due to the plasma gas.

[0050] The temperature during substrate processing is preferably 0 to 300° C., more preferably 10° C. or higher, and even more preferably 25° C. or higher, in order to more efficiently remove metal contaminants, and is more preferably 250° C. or lower, and even more preferably 200° C. or lower, in order to reduce damage to the substrate. Note that the temperature during substrate processing refers to the temperature of the substrate when processed by the processing method of the present disclosure, and is equal to the temperature of the stage when the substrate is placed on a stage.

[0051] The processing method of the present disclosure is a dry etching method for etching a silicon layer appearing on the inner surface of a hole or groove formed perpendicular to the substrate surface in a laminated film having a layered structure in which a silicon layer and an insulating film are laminated on a substrate, using an etching gas, ３ , BrF ５ , BrF ３ , IF ７ , IF５ and F ２ It is preferable to exclude "a dry etching method characterized by using a gas containing

[0052] [First Processing Method] Hereinafter, a first processing method according to the present disclosure will be described, in which a gas containing the first gas and a gas containing the second gas are simultaneously brought into contact with a substrate. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of F ２ and HF (Gas A containing the first gas and the second gas), the substrate is brought into contact with the gas A. Gas A contains at least the first gas and the second gas.

[0053] In the first processing method, the second gas can be used to reduce metal contamination on the substrate while performing processing using the first gas.

[0054] The first gas and the second gas contained in the gas A are as described above, including preferred embodiments thereof.

[0055] In gas A, the partial pressure of the first gas is preferably 0.005 to 1000 Pa, more preferably 0.05 to 100 Pa, even more preferably 0.1 to 20 Pa, and particularly preferably 0.5 to 5 Pa. In gas A, the sum of the partial pressure of the first gas and the partial pressure of the second gas is preferably 0.01 to 1333 Pa, more preferably 0.05 to 500 Pa, even more preferably 0.1 to 200 Pa, and particularly preferably 0.5 to 110 Pa. The partial pressure of the first gas is IF ７ Divided pressure of IF ５ Partial pressure of BrF ５ Partial pressure of BrF ３ partial pressure of MoF ６ partial pressure of GeF ４ partial pressure of ClF, partial pressure of ClF and ３The term "gas component" refers to the sum of the partial pressures of the gas components introduced into the system. The same applies to other similar descriptions. In this specification, the partial pressure of each gas component is measured using a pressure gauge. Specifically, the total pressure is measured using a pressure gauge, and the partial pressure of each gas component is calculated from the flow rate ratio of the gas components introduced.

[0056] In gas A, the ratio of the partial pressure of the first gas to the partial pressure of the second gas (partial pressure of the first gas / partial pressure of the second gas) is preferably 0.001 to 100, more preferably 0.005 to 50, even more preferably 0.01 to 10, particularly preferably 0.01 or more and less than 1.0, most preferably 0.01 to 0.8, and even more preferably 0.01 to 0.6.

[0057] Gas A is not particularly limited as long as it contains the first gas and the second gas, but may contain an inert gas in addition to the first gas and the second gas. Examples of the inert gas are as described above.

[0058] The total content of the first gas and the second gas may be, for example, 10 to 100% by volume relative to 100% by volume of gas A. In this case, the content of the inert gas may be, for example, 0 to 90% by volume relative to 100% by volume of gas A.

[0059] In 100% by volume of gas A, the total content of the first gas, the second 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.

[0060] The first gas is IF ７ , BrF ５ and GeF ４The gas A is at least one gas selected from the group consisting of: and the ratio of the "sum of the partial pressure of the first gas and the partial pressure of the second gas" to the total pressure ("sum of the partial pressure of the first gas and the partial pressure of the second gas" / total pressure) in gas A is preferably 0.1 to 1.0, more preferably 0.2 to 1.0, even more preferably 0.5 to 1.0, particularly preferably 0.8 to 1.0, and most preferably 0.9 to 1.0. This tends to more favorably achieve the effects of the present disclosure. This is because, when the "sum of the partial pressure of the first gas and the partial pressure of the second gas in gas A" / total pressure in the processing vessel is small, such as when it is less than 0.1, the amount of the first gas and the second gas present in the processing vessel is small to begin with, making it difficult for the problem of metal contamination on the substrate to occur, and there is a risk that the effects of the present disclosure may not be favorably achieved. Note that the partial pressure of the first gas in this paragraph refers to IF ７ Partial pressure of BrF ５ and GeF ４ means the sum of the partial pressures of

[0061] In the first processing method, it is preferable to carry out processing by placing a substrate in a processing vessel. In the first processing method, it is preferable to carry out a step of subjecting the processing vessel to a reduced pressure state after contacting Gas A with the substrate. This is because by-products generated during processing 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 processing, and generally means 0.133 kPa or less.

[0062] In the first processing method, it is preferable to carry out a step of replacing the atmosphere in the processing vessel with an inert gas after contacting the substrate with Gas A. This is because by-products generated during processing can be removed. In the first processing method, a step of replacing the atmosphere in the processing vessel with an inert gas may be carried out after carrying out a step of subjecting the processing vessel to a reduced pressure state.

[0063] [Second Processing Method] Next, as a processing method of the present disclosure, IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３a first step of contacting a substrate with a gas B containing at least one gas selected from the group consisting of: ２ and a second step of contacting a substrate with a gas C containing at least one gas selected from the group consisting of HF and HF (the second step of contacting a substrate with a gas C containing the second gas). Gas B contains at least the first gas, and gas C contains at least the second gas.

[0064] In the second processing method, after processing with the first gas, metal contamination on the substrate can be reduced by using the second gas.

[0065] The first gas contained in gas B and the second gas contained in gas C are as described above, including preferred embodiments.

[0066] Gas B is not particularly limited as long as it contains the first gas, but may also contain an inert gas other than the first gas. Gas C is not particularly limited as long as it contains the second gas, but may also contain an inert gas other than the second gas. Examples of inert gases are as described above.

[0067] The content of the first 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. The content of the second gas in 100% by volume of gas C 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.

[0068] In 100% by volume of Gas B, the total content of the first 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 second 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.

[0069] The partial pressure of the first gas in gas B is preferably 0.01 to 1333 Pa, more preferably 0.05 to 100 Pa, even more preferably 0.1 to 50 Pa, and particularly preferably 0.5 to 30 Pa.

[0070] The partial pressure of the second gas in gas C is preferably 0.01 to 13,333 Pa, more preferably 0.05 to 1,000 Pa, even more preferably 0.1 to 500 Pa, and particularly preferably 0.5 to 200 Pa.

[0071] The ratio of the partial pressure of the first gas in gas B to the partial pressure of the second gas in gas C (partial pressure of the first gas in gas B / partial pressure of the second gas in gas C) is the same as in the case of gas A.

[0072] In the second processing method, it is preferable to carry out processing by placing a substrate in a processing vessel. In the second processing method, it is preferable to carry out a step of reducing the pressure inside the processing vessel after contacting Gas B and Gas C with the substrate. This is because by-products generated during processing can be removed.

[0073] The second processing method preferably includes a step of replacing the atmosphere in the processing vessel with an inert gas after contacting Gas B and Gas C with the substrate. This is because by-products generated during processing can be removed. The second processing method may 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.

[0074] In the second processing method of the present disclosure, the above steps may be repeated multiple times to repeatedly process substrates.

[0075] (First Processing Method Using Processing Device) The first processing method can be realized, for example, by using the processing device shown in FIG. 1. FIG. 1 is a schematic diagram of the processing device used in the examples of the present disclosure. The first processing method will be specifically described below using the processing device of FIG. 1 as an example. The processing device of the present disclosure includes a mounting table on which a processing object is placed, and an IF for the processing object. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF３ a first gas supply unit that supplies at least one gas (first gas) selected from the group consisting of ２ and a second gas supply unit that supplies at least one gas (second gas) selected from the group consisting of HF and HF. The processing apparatus of the present disclosure may further include an inert gas supply unit that supplies an inert gas to the object to be processed.

[0076] In the first processing method, gas A containing a gas containing a first gas (also simply referred to as the first gas) and a gas containing a second gas (also simply referred to as the second gas) is brought into contact with a substrate. First, the substrate 10 to be processed is placed on the placement 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 processing vessel 110 is heated by the heating means 190.

[0077] When the workpiece 10 reaches a predetermined temperature, the second gas and the first gas are supplied at predetermined flow rates from the second gas supply unit 130 and the first gas supply unit 140 to the pipe 121. The second gas supply unit 130 adjusts the supply amount using valves V1 and V2 and a flow rate adjustment unit MFC1, and supplies the second gas from pipes 131 and 132 to the pipe 121. The first gas supply unit 140 adjusts the supply amount using valves V3 and V4 and a flow rate adjustment unit MFC2, and supplies the first gas from pipes 141 and 142 to the pipe 121.

[0078] 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.

[0079] In FIG. 1, PI1 and PI2 are pressure gauges, and the flow rate adjusting means and valves are controlled based on the indicated values.

[0080] The second gas and the first gas are mixed to a predetermined composition and supplied to the processing vessel 110. While the mixed gas is introduced into the processing vessel 110, the pressure inside the processing vessel 110 is controlled to a predetermined value. The processing is performed by contacting the gas with the substrate for a predetermined time. This first processing method allows for plasmaless processing without a plasma state, and does not require excitation of the gas by plasma or the like during processing. The gas flow rate can be set appropriately based on the volume and pressure of the processing vessel, etc.

[0081] Note that treatment involving a plasma state refers to placing a gas or the like at, for example, about 0.01 to 1.33 kPa inside a reactor, applying high-frequency power to an outer coil or a counter electrode to generate low-temperature gas plasma in the reactor, and performing treatment using the activated chemical species such as ions and radicals that are generated therein. In the treatment method disclosed herein, gas is brought into contact without a plasma state, and dry treatment can be performed without generating the above-mentioned gas plasma.

[0082] After the processing is completed, the heating by the heating means 190 is stopped to lower the temperature, and the vacuum pump 193 is stopped and the atmosphere is replaced with an inert gas to release the vacuum. As described above, the substrate can be processed by the processing method using the processing apparatus.

[0083] (Processing conditions in the first processing method) In the first processing method, the temperature of the substrate during processing is the same as the temperature during substrate processing described above. The temperature of the surface of the object to be processed may rise due to reaction heat. In the present disclosure, it is preferable that at least the temperature during substrate processing, i.e., the temperature inside the processing vessel or the temperature of the mounting part on which the object to be processed is placed, is within the above temperature range.

[0084] The pressure inside the treatment vessel during treatment is not particularly limited, but is usually 0.1 Pa to 101.3 kPa. It is preferable to perform treatment within the preferred partial pressure range described in [First Treatment Method].

[0085] The processing time of the first process is not particularly limited, but is preferably within 60 minutes in consideration of the efficiency of the semiconductor device manufacturing process. Here, the processing time of the first process refers to the time from when the gas is introduced into the processing vessel in which the object to be processed is placed until the mixed gas in the processing vessel is exhausted by a vacuum pump or the like to complete the processing.

[0086] (Second Processing Method Using Processing Apparatus) The second processing method can be realized, for example, by using the processing apparatus shown in Fig. 1. The second processing method will be specifically described below using the processing apparatus in Fig. 1 as an example.

[0087] In the second processing method, gas B containing the first gas is brought into contact with the substrate, and then gas C containing the second gas is brought into contact with the substrate.

[0088] First, the workpiece 10, which is a substrate, is placed on the placement 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 workpiece 10 is heated by the heating means 190.

[0089] When the workpiece 10 reaches a predetermined temperature, first, a first gas, which is gas B, is supplied from the first gas supply unit 140 to the pipe 121 at a predetermined flow rate. Alternatively, an inert gas may be supplied from the inert gas supply unit 150 to the pipe 121 at a predetermined flow rate. While the first gas, which is gas B, is being introduced into the processing vessel 110, the pressure inside the processing vessel 110 is controlled to a predetermined pressure. By introducing gas B into the processing vessel 110 for a predetermined time, the first gas is brought into contact with the substrate.

[0090] After evacuating the gas B containing the first gas, the second gas, which is gas C, is supplied from the second gas supply unit 130 to the pipe 121 at a predetermined flow rate. Alternatively, the inert gas may be supplied from the inert gas supply unit 150 to the pipe 121 at a predetermined flow rate. While the second gas, gas C, is being introduced into the processing vessel 110, the pressure inside the processing vessel 110 is controlled to a predetermined pressure. By introducing gas C into the processing vessel 110 for a predetermined time, metal contamination on the substrate can be reduced.

[0091] In the second processing method of the present disclosure, a cycle consisting of a first step of introducing a first gas into the processing vessel 110 and a second step of introducing a second gas into the processing vessel 110 can be repeated multiple times. In the second processing method of the present disclosure, it is preferable to perform the first step and then the second step. It is also preferable to perform a step of reducing the pressure inside the processing vessel or a step of replacing the atmosphere inside the processing vessel with an inert gas every cycle. After performing the first step, it is also possible to perform a step of reducing the pressure inside the processing vessel or a step of replacing the atmosphere inside the processing vessel with an inert gas.

[0092] In addition, the second processing method can also be performed without plasma, and gas excitation by plasma etc. is not required during processing. The flow rates of the second gas and the first gas can be appropriately set based on the volume and pressure of the processing vessel, etc.

[0093] In this way, in the second processing method using the above processing apparatus, the gas can be brought into contact with the substrate without a plasma state, and dry processing can be performed without generating the above-mentioned gas plasma.

[0094] After the process is completed, the heating by the heating means 190 is stopped to lower the temperature, and the vacuum pump 193 is stopped and the atmosphere is replaced with an inert gas to release the vacuum. In this manner, the substrate can be processed.

[0095] (Processing conditions in the second processing method) In the second processing method, the temperature of the substrate when the first step is performed and the temperature of the substrate when the second step is performed are the same as the temperature when the substrate is processed as described above. The temperature of the surface of the object to be processed may rise due to reaction heat. In the present disclosure, it is preferable that at least the temperature when the substrate is processed, i.e., the temperature inside the processing vessel or the temperature of the mounting part on which the object to be processed is placed, is within the above temperature range.

[0096] Furthermore, when Gas B is brought into contact with the substrate and when Gas C is brought into contact with the substrate, the pressure inside the processing vessel in which the substrate is placed is not particularly limited, but is usually 0.1 Pa to 101.3 kPa. Note that it is preferable to perform processing within the preferred partial pressure range explained in [Second Processing Method].

[0097] The processing times for the first step and the second step are not particularly limited, but the processing time for one cycle of the first step is preferably 60 minutes or less, and the processing time for one cycle of the second step is preferably 60 minutes or less. Here, the processing time refers to the time from when a gas is introduced into a processing vessel in which a workpiece is placed until the gas in the processing vessel is subsequently evacuated by a vacuum pump or the like to complete the processing.

[0098] [Metal Concentration on Substrate After Treatment] The concentration of at least one metal atom selected from the group consisting of chromium, titanium, and molybdenum remaining on the surface of the substrate after the treatment method of the present disclosure is 1×10 １１ atoms / cm ２ Preferably, it is 5×10 or less. １０ atoms / cm ２ More preferably, it is 1×10 or less. １０ atoms / cm ２ It is more preferable that:

[0099] [Method for manufacturing a semiconductor device] The processing method of the present disclosure described above can be used for etching, film formation, and surface fluorination treatment in the manufacturing process of a semiconductor device. A semiconductor device can be manufactured by processing a substrate using the processing method of the present disclosure. The method for manufacturing a semiconductor device of the present disclosure is characterized by including a step of processing a substrate by applying the processing method of the present disclosure to the substrate. The step of supplying a gas containing a first gas and a gas containing a second gas to the substrate and processing it can be performed by the processing method of the present disclosure described above.

[0100] Examples of the present disclosure are listed below along with comparative examples, but the present disclosure is not limited to the following examples. In the examples and comparative examples, the gases used in the first step and the second step are as shown in Tables 1 and 2. Each gas is not diluted with an inert gas or the like (contains no components other than those listed in Tables 1 and 2). For the gas used in the first step in Table 1, the content of Gas 1 in the gas is 100% by volume. For the gas used in the second step in Table 1, the content of Gas 3 in the gas is 100% by volume. For the gas used in the first step in Table 2, the total content of Gas 1 and Gas 2 in the gas is 100% by volume. The contents of chromium, titanium, and molybdenum in the gases used in this process are each 10 ppb by mass or less.

[0101] [Comparative Example 1] IF ７ A processing apparatus was constructed by connecting a cylinder filled with IF to a processing vessel made of Al (A6063) using metal piping made of SUS304. Substrate processing was carried out using the processing apparatus shown in Figure 1. A silicon wafer (substrate) was introduced into the processing vessel, and the stage temperature was set to 25°C. ７ was passed through the gas for 100 seconds under a pressure of 1 Pa (IF in the gas). ７ The metal concentration on the silicon wafer was then quantified using an ICP-MS (inductively coupled plasma mass spectrometer). The Cr concentration was 670×10 １０ atoms / cm ２ , Ti is 550 × 10 １０ atoms / cm ２ , 43 x 10 １０ atoms / cm ２ In Comparative Example 1, as shown in Table 1, only the first step was carried out.

[0102] (Measurement of metal concentration on silicon wafer) Hydrofluoric acid was placed in a plastic beaker and placed in a container made of PFA (perfluoroalkoxy fluororesin) called a VPD (vapor phase decomposition) container, and the wafer was placed on a wafer stand installed in the VPD container. Next, the VPD container was closed, and the native oxide film on the wafer was decomposed for 10 minutes with hydrofluoric acid vapor. 1 mL of scanning solution (acid solution (a mixture of aqueous hydrogen fluoride and aqueous hydrogen peroxide solutions)) was dropped onto the surface of the wafer, and the entire surface of the wafer was scanned. After scanning, the scanned droplet was dissolved in ultrapure water and then analyzed by ICP-MS (inductively coupled plasma mass spectrometry). The analytical values ​​obtained were calculated from the amount of dissolved solution and the surface area of ​​the wafer, and the concentration of metals per 1 cm of the wafer was measured. 2 The number of metal atoms per unit mass was calculated.

[0103] Comparative Examples 2 to 11 were carried out in the same manner as Comparative Example 1, except that the conditions were changed as shown in Table 1. In Comparative Examples 2 to 11, only the first step was carried out, as shown in Table 1.

[0104] (Alternate Flow) [Example 1] Wafer processing was carried out using the same apparatus as in Comparative Example 1. As the first step, IF ７ was passed through the gas for 100 seconds under a pressure of 1 Pa (IF in the gas). ７ Content: 100% by volume. Then, in the second step, ２ was passed through the gas for 100 seconds under a pressure of 1 Pa (F in the gas). ２ After the second step, the metal concentration on the silicon wafer was quantified using an ICP-MS (inductively coupled plasma mass spectrometer). １０ atoms / cm ２ , Ti concentration is 0.8 × 10 １０ atoms / cm ２ , Mo concentration is 0.2 × 10 １０ atoms / cm ２ In Example 1, it was confirmed that IF ７ , F ２ were supplied alternately.

[0105] Examples 2 to 5 were carried out in the same manner as in Example 1, except that the conditions were changed as shown in Table 1. In Examples 2 to 5, Gas 1 and Gas 3 were supplied alternately.

[0106] (Simultaneous Distribution) [Example 6] In accordance with the conditions shown in Table 2, IF was used as the first step. ７ and F ２ were simultaneously supplied at a volume ratio of 1:2 and allowed to flow for 100 seconds under a total pressure condition of 1.5 Pa (stage temperature 150°C) (IF in the gas). ７ and F ２ The total content of the above: 100% by volume. The other steps were the same as in Example 1. In Example 6, as shown in Table 2, only the first step was carried out.

[0107] Examples 7 to 15 In accordance with the conditions shown in Table 2, in the first step, gas 1 and gas 2 were supplied at a volume ratio that resulted in the partial pressures shown in Table 2, the pressure conditions were changed to a pressure condition in which the total pressure was the sum of the partial pressures of gas 1 and gas 2, and the stage temperature was set to a temperature shown in Table 2, except that the same procedures as in Example 6 were carried out.

[0108]

[0109]

[0110] From Tables 1 and 2, even under the processing conditions in which Cr, Ti, and Mo adhere to the wafer (Comparative Examples 1 to 11), F ２ By flowing HF, the concentrations of Cr, Ti, and Mo on the wafer were reduced (Examples 1 to 5). ２ Alternatively, even when HF was simultaneously passed through, the concentrations of Cr, Ti, and Mo on the wafer were reduced (Examples 6 to 15).

[0111] From the above, IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ At least one gas selected from the group consisting of F ２ It was found that the processing method of the example in which the substrate is processed with at least one gas selected from the group consisting of HCl and HF can reduce metal contamination on the substrate.

[0112] REFERENCE SIGNS LIST 10 Object to be processed 100 Processing apparatus 110 Processing container 111 Mounting section 121 Pipe 130 Second gas supply section 131, 132 Pipe 140 First gas supply section 141, 142 Pipe 150 Inert gas supply section 151, 152 Pipe 190 Heating means 191, 192 Pipe 193 Vacuum pump 194 Liquid nitrogen trap MFC1, MFC2, MFC3 Flow rate adjusting means PI1, PI2 Pressure gauge V1, V2, V3, V4, V5, V6, V7, V8 Valve

Claims

1. IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ at least one gas (first gas) selected from the group consisting of: ２ and at least one gas (second gas) selected from the group consisting of HF.

2. The first gas is IF ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ 2. The method according to claim 1, wherein the gas is at least one selected from the group consisting of ClF and ClF.

3. The first gas is IF ７ , BrF ５ and GeF ４ 2. The method according to claim 1, wherein the gas is at least one gas selected from the group consisting of:

4. The first gas is IF ７ 2. The method according to claim 1, wherein 5. The method according to claim 1, wherein the temperature during the substrate treatment is 0 to 300°C.

6. The processing method according to claim 1, wherein a gas A containing the first gas and the second gas is brought into contact with the substrate.

7. The processing method according to claim 6, wherein the sum of the partial pressures of the first gas and the second gas in gas A is 0.01 to 1333 Pa.

8. The processing method according to claim 6, wherein the ratio of the partial pressure of the first gas to the partial pressure of the second gas in gas A (partial pressure of the first gas / partial pressure of the second gas) is 0.001 to 100.

9. The processing method according to claim 6, wherein the ratio of the partial pressure of the first gas to the partial pressure of the second gas in gas A (partial pressure of the first gas / partial pressure of the second gas) is 0.01 or more and less than 1.

0.

10. The first gas is IF ７ , BrF ５ and GeF ４ and wherein the ratio of the "sum of the partial pressure of the first gas and the partial pressure of the second gas" to the total pressure in Gas A ("sum of the partial pressure of the first gas and the partial pressure of the second gas" / total pressure) is 0.1 to 1.

0.

11. A processing method according to claim 1, comprising a first step of contacting a substrate with a gas B containing the first gas, and a second step of contacting a substrate with a gas C containing the second gas.

12. The processing method according to claim 11, wherein the partial pressure of the first gas in gas B is 0.01 to 1333 Pa.

13. The processing method according to claim 11, wherein the partial pressure of the second gas in gas C is 0.01 to 13,333 Pa.

14. The concentration of at least one metal atom selected from the group consisting of chromium, titanium, and molybdenum remaining on the surface of the substrate after treatment is 1×10 １１ atoms / cm ２ 2. The method of claim 1, wherein:

15. A method for manufacturing a semiconductor device, comprising the step of processing a substrate by applying the processing method according to any one of claims 1 to 14 to the substrate.

16. A mounting table for mounting an object to be processed; and an IF for the object to be processed. ７ , IF ５ , BrF ５ , BrF ３ , MoF ６ , GeF ４ , ClF and ClF ３ a first gas supply unit that supplies at least one gas selected from the group consisting of F ２ and a second gas supply unit that supplies at least one gas selected from the group consisting of HCl and HF.

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