Dry etching method, cleaning method, and method for manufacturing semiconductor device

Abstract

The dry etching method of the present disclosure is to etch a film to be etched formed on the surface of an object to be processed, the film to be etched containing a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the metal, or a nitride of the metal, by bringing the film to be etched into contact with a beta-diketone and a gas containing halogen atoms in the molecules.

Description

Technical Field

[0001] The present disclosure relates to a dry etching method, a cleaning method, and a method for manufacturing a semiconductor device. Background Art

[0002] In the manufacturing process of semiconductor devices, a metal film formed on a substrate as a wiring material, a metal gate material, an electrode material, or a magnetic material is sometimes etched. For example, it is known that HFAc (hexafluoroacetylacetone), which is a β-diketone that forms a complex with a metal, is used in the etching of such a metal film.

[0003] On the other hand, in the manufacturing process of semiconductor elements, when a metal film is formed by a film forming device, an unnecessary metal film or the like will be attached to the surface inside the film forming device such as the inner wall in the film forming chamber of the device, and therefore it is necessary to remove it. After taking out the substrate from the chamber, as a method of removing the unnecessary metal film or the like in a heated state in the chamber, a method of cleaning using the etching function of β-diketone is also known. For example, a dry cleaning method is known in which a metal oxide film is reacted and removed as a metal complex by contacting HFAc with the metal oxide film (Patent Document 1).

[0004] In addition, there is also a known dry cleaning method that uses oxygen in combination with β-diketone to easily react and remove the metal film as a metal complex (Patent Document 2, Patent Document 3). In addition, as a cleaning method for metal films, studies have been conducted on efficiently etching metal films by using various additive gases other than β-diketone, for example, a cleaning method in which a specific metal contained in the aforementioned metal film reacts with β-diketone after a heat reaction treatment using a gas containing chlorine atoms in the molecule and the product is removed (Patent Document 4); an example of using HF as an additive gas for β-diketone (Patent Document 5); an example of using nitrogen oxides (NO, N2O, NO2) as an additive gas (Patent Documents 6 to 8); an example of using halogen-containing substances as an additive gas (Patent Document 9), etc.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-176807

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 11-140652

[0009] Patent Document 3: Japanese Patent Application Publication No. 2012-149288

[0010] Patent Document 4: Japanese Patent Application Publication No. 2005-116716

[0011] Patent Document 5: Japanese Patent Application Publication No. 2006-080103

[0012] Patent Document 6: Japanese Patent Application Publication No. 2013-194307

[0013] Patent Document 7: Japanese Patent Application Publication No. 2019-169724

[0014] Patent Document 8: International Publication No. 2021 / 79624

[0015] Patent Document 9: Japanese Patent Application Publication No. 2017-059824 Summary of the invention

[0016] Problem that the invention aims to solve

[0017] Typically, after a metal film is deposited on the surface of a substrate, when the metal film attached to the surface other than the substrate is etched, a high temperature is reached in the chamber, and therefore, it is desired that, for example, the inner wall (side wall, etc.) be as low as possible. However, at relatively low temperatures (for example, around 250°C), the following problem arises: even if one wants to use additive gases such as β-diketone and oxygen to etch and remove the metal film to be removed, etching cannot be performed.

[0018] In addition, depending on the type of metal film, due to the catalytic effect of metals and their metal oxides, for example, it is confirmed that HFAc decomposes at a temperature lower than the decomposition temperature of HFAc (375°C), and there is also a concern that a film mainly composed of carbon derived from HFAc remains on the substrate after etching. In addition, for example, the method described in Patent Document 4 uses hydrogen chloride (HCl) gas and performs a thermal reaction treatment on a metal film containing Ti, Zr and Pb at 300°C or 500°C, but depending on the type of metal film, the thermal reaction treatment may also reach a higher temperature, and from the perspective of the corrosion resistance of the etching device, the lower the etching temperature, the better. Therefore, it is desired to develop an etching gas that can achieve a lower etching temperature or at the same time increase the etching speed.

[0019] In view of the above problems, the present disclosure aims to provide a dry etching method using a gas composition that can etch a metal oxide film, a metal nitride film, or a metal film without plasma.

[0020] Solutions for solving problems

[0021] The inventors of the present invention conducted intensive research and found that by using β-diketone and a gas containing halogen atoms in the molecule (hereinafter, this gas is sometimes referred to as "additive gas" in this specification) as an etching gas, it is possible to etch oxide films of specific metals such as In at a high etching rate, thereby completing the present disclosure.

[0022] That is, the present disclosure provides a dry etching method, a cleaning method, and a method for manufacturing a semiconductor device as described in the following [1] to

[30] .

[0023] [1] A dry etching method, which involves etching a film to be etched formed on the surface of a processed object by contacting it with β-diketone and a gas containing halogen atoms in its molecules, wherein the film to be etched contains: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the above metal or a nitride of the above metal.

[0024] [2] A dry etching method according to [1] above, wherein the metal, metal oxide or metal nitride is at least one selected from the group consisting of indium oxide, gallium oxide, copper oxide, cobalt oxide, iron oxide, tin oxide, zinc oxide, aluminum oxide, tantalum oxide, indium gallium zinc oxide, indium tin oxide, gallium nitride, indium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

[0025] [3] The dry etching method according to [1] or [2] above, wherein the gas containing halogen atoms in the molecules is at least one selected from the group consisting of HF, F2, ClF3, IF7, HCl and Cl2.

[0026] [4] The dry etching method according to any one of [1] to [3] above, wherein the β-diketone is at least one selected from the group consisting of hexafluoroacetylacetone, trifluoroacetylacetone, and acetylacetone.

[0027] [5] The dry etching method according to any one of [1] to [4] above, wherein the etching is performed in a non-plasma state.

[0028] [6] The dry etching method according to any one of [1] to [5] above, wherein an etching gas A containing the β-diketone and the gas containing a halogen atom in its molecule is brought into contact with the film to be etched.

[0029] [7] The dry etching method according to [6] above, wherein the temperature of the film to be etched when the etching gas A contacts the film to be etched is 50° C. or higher and 300° C. or lower.

[0030] [8] The dry etching method according to [6] or [7] above, wherein the amount of β-diketone contained in the etching gas A is 10% by volume or more and 90% by volume or less.

[0031] [9] The dry etching method according to any one of [6] to [8] above, wherein the amount of the gas containing halogen atoms in the molecule contained in the etching gas A is greater than or equal to 0.1% by volume and less than or equal to 50% by volume.

[0032]

[10] The dry etching method according to any one of [6] to [9] above, wherein the etching gas A further contains at least one oxidizing gas selected from the group consisting of O 2 , NO, NO 2 , and N 2 O.

[0033]

[11] The dry etching method according to any one of [6] to

[10] above, wherein the etching gas A further contains at least one inert gas selected from the group consisting of N 2 , Ar, He, Ne and Kr.

[0034]

[12] A dry etching method according to any one of [6] to

[11] above, wherein when the etching gas A contacts the film to be etched, the pressure in a processing container in which the object to be processed having the film to be etched is placed is greater than 0.1 kPa and less than 101.3 kPa.

[0035]

[13] A dry etching method according to any one of [1] to [5] above, comprising: a first etching step of bringing an etching gas B containing a gas having halogen atoms in its molecules into contact with the film to be etched; and a second etching step of bringing an etching gas C containing the β-diketone into contact with the film to be etched.

[0036]

[14] The dry etching method according to

[13] above, wherein the temperature of the etched film when the etching gas B contacts the etched film and the temperature of the etched film when the etching gas C contacts the etched film are greater than 50°C and less than 300°C.

[0037]

[15] The dry etching method according to

[13] or

[14] above, wherein the etching gas B and / or etching gas C further contains at least one oxidizing gas selected from the group consisting of O2, NO, NO2 and N2O.

[0038]

[16] A dry etching method according to any one of

[13] to

[15] above, wherein the etching gas B and / or etching gas C further contains at least one inactive gas selected from the group consisting of N 2 , Ar, He, Ne and Kr.

[0039]

[17] A dry etching method according to any one of

[13] to

[16] above, wherein when the etching gas B contacts the etched film and when the etching gas C contacts the etched film, the pressure in a processing container in which the processed body having the etched film formed thereon is placed is greater than 0.1 kPa and less than 101.3 kPa.

[0040]

[18] A cleaning method, characterized in that deposited matter on the surface of a processing container of a substrate processing device is removed by bringing the deposited matter into contact with β-diketone and a gas containing halogen atoms in its molecules, wherein the deposited matter comprises: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the above metal or a nitride of the above metal.

[0041]

[19] A cleaning method according to

[18] above, wherein the metal, metal oxide or metal nitride is at least one selected from the group consisting of indium oxide, gallium oxide, copper oxide, cobalt oxide, iron oxide, tin oxide, zinc oxide, aluminum oxide, tantalum oxide, indium gallium zinc oxide, indium tin oxide, gallium nitride, indium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

[0042]

[20] The cleaning method according to

[18] or

[19] above, wherein at least one oxidizing gas selected from the group consisting of O 2 , NO, NO 2 and N 2 O is further brought into contact with the deposit.

[0043]

[21] A method for manufacturing a semiconductor device, comprising the following steps: applying the dry etching method described in any one of [1] to

[17] to a film on a substrate to etch the film, wherein the film comprises: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the above metal or a nitride of the above metal.

[0044]

[22] A dry etching method, which involves etching a film to be etched formed on the surface of a processed object by contacting it with β-diketone and a gas containing chlorine atoms in its molecules, wherein the film to be etched comprises: a metal containing at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two of the metals containing at least one of Ga, Sn or Zn, an oxide of the above metals, or a nitride of the above metals.

[0045]

[23] A dry etching method according to

[22] above, wherein the metal, metal oxide or metal nitride is at least one selected from the group consisting of indium gallium zinc oxide, indium zinc oxide, aluminum zinc oxide, gallium zinc oxide, indium gallium zinc tin oxide, indium tin zinc oxide, indium tin oxide, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

[0046]

[24] The dry etching method according to

[22] or

[23] above, wherein the gas containing chlorine atoms in the molecules is at least one selected from the group consisting of HCl, Cl2, BCl3 and SiCl4.

[0047]

[25] The dry etching method according to any one of

[22] to

[24] above, wherein the β-diketone is at least one selected from the group consisting of hexafluoroacetylacetone, trifluoroacetylacetone, and acetylacetone.

[0048]

[26] The dry etching method according to any one of

[22] to

[25] above, wherein the etching is performed in a non-plasma state.

[0049]

[27] The dry etching method according to any one of

[22] to

[26] above, wherein an etching gas D containing the β-diketone and the gas containing chlorine atoms in the molecule is brought into contact with the film to be etched.

[0050]

[28] The dry etching method according to

[27] above, wherein the amount of the gas containing chlorine atoms in the molecules contained in the etching gas D is greater than 1 volume % and less than 60 volume %.

[0051]

[29] A dry etching method according to any one of

[22] to

[26] above, comprising: a third etching step of bringing an etching gas E containing a gas having chlorine atoms in its molecules into contact with the film to be etched; and a fourth etching step of bringing an etching gas F containing the β-diketone into contact with the film to be etched.

[0052]

[30] A method for manufacturing a semiconductor device, comprising the following steps: applying the dry etching method described in any one of

[22] to

[29] to a film on a substrate to etch the film, wherein the film comprises: a metal containing at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two containing at least one of Ga, Sn or Zn, an oxide of the above metal or a nitride of the above metal.

[0053] Effects of the Invention

[0054] According to the present disclosure, by using β-diketone and a gas containing a halogen atom in the molecule as an etching gas, an effect of being able to etch an oxide film of a specific metal such as In at a low temperature and a high etching rate is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a schematic diagram of an etching apparatus used in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0056] Hereinafter, the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, and can be appropriately implemented based on the general knowledge of those skilled in the art within the scope not impairing the gist of the present disclosure.

[0057] <Dry Etching Method I>

[0058] The dry etching method I disclosed in the present invention is to etch a film to be formed on the surface of a processed object by contacting the film to be etched with β-diketone and a gas containing halogen atoms in the molecule, wherein the film to be etched contains: at least one metal selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the above metal or a nitride of the above metal.

[0059] In the dry etching method I disclosed in the present invention, when β-diketone and a gas containing halogen atoms in the molecule as an additive gas, such as HF (hydrogen fluoride), are brought into contact with the above-mentioned metal film, metal oxide film or metal nitride film, the film surface is fluorinated by HF to form a metal fluoride, thereby increasing the reactivity with β-diketone and promoting the formation of a complex. As a result, there are advantages in that the etching temperature is lowered and the etching rate is also increased. The dry etching method I disclosed in the present invention can provide a dry etching method that can etch a difficult-to-etch film even at a temperature below 350°C, and further below 300°C.

[0060] The metal, metal oxide or metal nitride contained in the etched film etched by the dry etching method I of the present disclosure may be an alloy containing two or more of the above metals, an oxide of the alloy or a nitride of the alloy. Examples of the above metal, metal oxide or metal nitride include: In (indium), Ga (gallium), Cu (copper), Co (cobalt), Fe (iron), Sn (tin), Zn (zinc), Al (aluminum), Ta (tantalum), As (arsenic), indium gallium arsenic, indium oxide (InO q (q is greater than or equal to 1 and less than or equal to 2), especially In2O3), gallium oxide (GaO p (p is 1 or more and 2 or less), especially Ga2O3), copper oxides [cuprous oxide, cupric oxide], cobalt oxides, iron oxides, tin oxides, zinc oxides, aluminum oxides (AlOv (v is 1 or more and 2 or less), especially Al2O3), tantalum oxide, indium gallium zinc oxide [In a Ga b Zn c O d (a and b are respectively greater than 1 and less than 3, c is greater than 0.5 and less than 4, d is greater than 4 and less than 10, referred to as "IGZO"). InGaZnO4, In2Ga2ZnO7, etc. (InGaO3) are particularly preferred. a (ZnO) c [representation], indium tin oxide (a mixture of indium oxide (In2O3) and tin oxide (SnO2), referred to as "ITO"), indium nitride, gallium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, copper nitride, cobalt nitride, iron nitride, tin (IV) nitride, zinc nitride, indium gallium nitride, etc. As the metal, metal oxide, and metal nitride contained in the etched film, it is preferred that at least one of the group consisting of indium oxide, gallium oxide, copper oxide, cobalt oxide, iron oxide, tin oxide, zinc oxide, aluminum oxide, tantalum oxide, indium gallium zinc oxide, indium tin oxide, gallium nitride, indium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, indium gallium nitride, and indium gallium arsenic is selected.

[0061] In the dry etching method I disclosed in the present invention, as the object to be processed, there can be cited: a silicon substrate, a compound semiconductor substrate, a quartz substrate, and a glass substrate. In addition to the above-mentioned etched film, a silicon film, a silicon oxide film, a silicon nitride film, a metal wiring film other than the above-mentioned metal, etc. may be formed on the surface of the object to be processed.

[0062] There is no particular limitation on the method of forming the etched film on the surface of the object to be processed, and examples thereof include chemical vapor deposition (CVD) and sputtering. In addition, there is no particular limitation on the thickness of the etched film, and for example, the thickness can be set to be greater than 0.1 nm and less than 1 μm.

[0063] In the dry etching method I of the present disclosure, β-diketone and a gas containing a halogen atom in the molecule are used as etching gas.

[0064] The type of β-diketone is not particularly limited, but is preferably at least one selected from the group consisting of hexafluoroacetylacetone (HFAc, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione), trifluoroacetylacetone (1,1,1-trifluoro-2,4-pentanedione) and acetylacetone (2,4-pentanedione).

[0065] The type of gas containing a halogen atom in the molecule is not particularly limited, but is preferably at least one selected from the group consisting of HF, F2, ClF3, IF7, HCl and Cl2. When used in combination with β-diketone, HF and HCl are more preferred.

[0066] The dry etching method I disclosed herein preferably allows β-diketone and a gas containing halogen atoms in the molecule to contact the film to be etched without plasma. The reason is that when the object to be processed is a semiconductor device substrate, if it contacts the plasma gas, the substrate may be electrically damaged by the plasma gas.

[0067] [First dry etching method]

[0068] Hereinafter, the first dry etching method in which the above-mentioned β-diketone and a gas containing halogen atoms in the molecule (additive gas) are brought into contact with the etched film at the same time in the dry etching method I of the present disclosure will be described. In the first dry etching method, an etching gas A containing the above-mentioned β-diketone and the additive gas is brought into contact with the above-mentioned etched film. The etching gas A contains at least β-diketone and a gas containing halogen atoms in the molecule.

[0069] Examples of the β-diketone contained in the etching gas A include the same ones as those described above.

[0070] The amount of β-diketone contained in the etching gas A is preferably 5% by volume or more and 95% by volume or less, more preferably 10% by volume or more and 90% by volume or less. If the proportion of β-diketone in the etching gas A is too small, the etching rate tends to decrease, and if it is too large, the etching gas becomes too expensive. In addition, when the additive gas in the etching gas A is too little or too much, etching is difficult to proceed.

[0071] The amount of the additive gas contained in the etching gas A is preferably 0.1% by volume or more and 50% by volume or less, more preferably 1% by volume or more and 40% by volume or less, and still more preferably 5% by volume or more and 30% by volume or less.

[0072] The volume ratio of β-diketone and added gas (gas containing halogen atoms in the molecule) contained in the etching gas A can be β-diketone:added gas = 1:0.01 or more and 100 or less, or β-diketone:added gas = 1:0.1 or more and 10 or less, or β-diketone:added gas = 1:0.1 or more and 1 or less.

[0073] The etching gas A may further contain at least one oxidizing gas selected from the group consisting of O 2 , NO, NO 2 , and N 2 O.

[0074] The etching gas A may further contain at least one inert gas selected from the group consisting of N 2 , Ar, He, Ne, and Kr.

[0075] When an oxidizing gas is used, the content of the oxidizing gas contained in the etching gas A can be set to 10 volume % or more and 90 volume % or less.

[0076] When the etching gas A contains an inert gas, the content of the inert gas contained in the etching gas A is preferably 1 volume % or more and 90 volume % or less.

[0077] The first dry etching method preferably places the above-mentioned object to be processed in a processing container and performs etching. The first dry etching method preferably performs a step of giving a reduced pressure state in the processing container after the etching gas A contacts the film to be etched. The reason is that byproducts generated during etching can be removed.

[0078] The reduced pressure state refers to a state in which the pressure in the processing container is lower than the pressure during etching, and is generally 0.133 kPa or less.

[0079] In the first dry etching method, it is preferable to perform a step of replacing the inside of the processing container with an inert gas after the etching gas A contacts the film to be etched. The reason is that byproducts generated during etching can be removed.

[0080] The first dry etching method may perform a step of replacing the inside of the processing container with an inert gas after performing a step of providing a reduced pressure state inside the processing container.

[0081] [Second dry etching method]

[0082] Next, the second dry etching method as the dry etching method I of the present disclosure is described, and the second dry etching method includes: a first etching step of bringing the etching gas B containing the gas containing halogen atoms in the molecules into contact with the etched film; and a second etching step of bringing the etching gas C containing the β-diketone into contact with the etched film. The etching gas B contains at least a gas containing halogen atoms in the molecules (additive gas), and the etching gas C contains at least β-diketone.

[0083] Examples of the β-diketone contained in the etching gas C include the same β-diketone as described above.

[0084] The etching gas B may contain only the additive gas, the etching gas C may contain only β-diketone, and the etching gas B and / or the etching gas C may further contain: at least one oxidizing gas selected from the group consisting of O2, NO, NO2 and N2O. The etching gas B and / or the etching gas C may further contain: at least one inactive gas selected from the group consisting of N2, Ar, He, Ne and Kr.

[0085] The content of the additional gas contained in the etching gas B can be set to, for example, 10% by volume or more and 100% by volume or less. The content of β-diketone contained in the etching gas C can be set to 10% by volume or more and 100% by volume or less.

[0086] When the etching gas B and the etching gas C contain an oxidizing gas, the content of the oxidizing gas contained in each of the etching gas B and the etching gas C can be set to 10 volume % or more and 90 volume % or less.

[0087] When the etching gas B and the etching gas C contain an inert gas, the content of the inert gas contained in each of the etching gas B and the etching gas C is preferably 1% by volume or more and 90% by volume or less.

[0088] The second dry etching method preferably places the above-mentioned object to be processed in a processing container and performs etching. The second dry etching method preferably performs a step of giving a reduced pressure state in the processing container after the etching gas B and the etching gas C contact the film to be etched. The reason is that byproducts generated during etching can be removed.

[0089] The second dry etching method preferably includes a step of replacing the interior of the processing container with an inert gas after the etching gas B and the etching gas C come into contact with the film to be etched. This is because byproducts generated during etching can be removed.

[0090] The second dry etching method may perform a step of replacing the inside of the processing container with an inert gas after performing the step of providing the inside of the processing container with a reduced pressure state.

[0091] In the second dry etching method disclosed herein, the above process can be repeated multiple times in order to repeatedly etch the etched film. In one cycle of the etching process, the etched film can be etched to a certain thickness, so by limiting the number of cycles, a layer of a desired thickness can be precisely etched.

[0092] (First dry etching method using etching apparatus)

[0093] The first dry etching method can be used, for example, Figure 1 This is achieved by the etching device shown. Figure 1 Schematic diagram of the etching device used in the embodiment of the present disclosure. Figure 1 The first dry etching method is specifically described by taking the etching device as an example.

[0094] In the first dry etching method, an etching gas A containing β-diketone and a gas containing a halogen atom in its molecule is brought into contact with a film to be etched.

[0095] First, the object 10 to be processed, on which an etching film including a metal, an oxide of the metal, or a nitride of the metal is formed, is placed on the placement portion 111 in the processing container 110. Next, the processing container 110, the pipe 121, the pipes 131 and 132, the pipes 141 and 142, the pipes 151 and 152, the liquid nitrogen cold trap 194, and the pipes 191 and 192 are evacuated to a predetermined pressure by the vacuum pump 193, and then the object 10 to be processed is heated by the heating unit 190.

[0096] After the object 10 to be processed reaches a predetermined temperature, the β-diketone gas and the additive gas are supplied to the pipe 121 at a predetermined flow rate from the β-diketone gas supply unit 130 and the additive gas supply unit 140. The β-diketone gas supply unit 130 adjusts the supply amount through valves V1 and V2 and the flow rate adjustment unit MFC1, and supplies the β-diketone gas from the pipes 131 and 132 to the pipe 121. The additive gas supply unit 140 adjusts the supply amount through valves V3 and V4 and the flow rate adjustment unit MFC2, and supplies the additive gas from the pipes 141 and 142 to the pipe 121.

[0097] The inert gas supply unit 150 can supply the inert gas at a predetermined flow rate to the pipe 121. The inert gas supply unit 150 supplies the inert gas from pipes 151 and 152 to the pipe 121 while adjusting the supply amount using valves V5 and V6 and a flow control unit MFC3.

[0098] Alternatively, an oxidizing gas may be supplied from an oxidizing gas supply unit (not shown) to the pipe 121 at a predetermined flow rate.

[0099] in addition, Figure 1 In FIG. 1 , PI1 and PI2 are pressure gauges, and each flow regulating unit and each valve are controlled based on their indicated values.

[0100] The β-diketone gas and the additive gas are mixed with a predetermined composition and supplied to the processing container 110. While the mixed gas is introduced into the processing container 110, the pressure in the processing container 110 is controlled to be predetermined. Etching is performed by reacting the etching gas with the etched film containing the metal, the oxide of the above metal, or the nitride of the above metal within a predetermined time to form a complex. The first dry etching method can perform etching in a plasma-free state without accompanying a plasma state, and during etching, the etching gas can be excited without using plasma or the like. The flow rate of the etching gas can be appropriately set based on the volume and pressure of the processing container.

[0101] It should be noted that etching accompanied by a plasma state means that a gas of, for example, about 0.01 to 1.33 kPa is introduced into the interior of the reaction device, and high-frequency power is applied to the outer coil or counter electrode, thereby generating a low-temperature gas plasma in the reaction device, and etching is performed by active chemical species such as ions or free radicals generated therein.

[0102] In the dry etching method I of the present disclosure, the gas is brought into contact without accompanying plasma, and dry etching can be performed without generating the gas plasma.

[0103] After the etching is completed, the heating by the heating unit 190 is stopped to cool down, and the vacuum pump 193 is stopped to replace with an inert gas to open the vacuum. As described above, the etching film including the above metal, the above metal oxide or the above metal nitride can be etched by the dry etching method using the above etching apparatus.

[0104] (Etching Conditions of the First Dry Etching Method)

[0105] In the first dry etching method, the temperature of the film to be etched during etching can be any temperature at which the complex can be vaporized, preferably 50° C. to 350° C., more preferably 50° C. to 300° C., and even more preferably 200° C. to 300° C. If the temperature is in the above range, the etching efficiency is high and the damage to the substrate is small.

[0106] The temperature of the surface of the object to be processed is substantially equal to the temperature of the film to be etched. If β-diketone and a gas containing halogen atoms in the molecule are simultaneously brought into contact with the heated film to be etched, the metal on the surface of the film to be etched is fluorinated by the gas containing halogen atoms in the molecule to form a metal fluoride, and then β-diketone reacts with the metal fluoride to form a complex on the surface of the film to be etched. The vapor pressure of the complex is high, so the film to be etched can be removed by gasification of the complex.

[0107] The pressure in the processing container during etching is not particularly limited, but is usually 0.1 kPa to 101.3 kPa.

[0108] From the viewpoint of obtaining a sufficient etching rate, the pressure in the processing container during etching is preferably 2.67 kPa to 39.9 kPa, and more preferably 2.67 kPa to 26.7 kPa.

[0109] The etching processing time is not particularly limited, but is preferably within 60 minutes if the efficiency of the semiconductor device manufacturing process is taken into consideration. Here, the etching processing time refers to the time from the introduction of etching gas into the processing container where the object to be processed is disposed until the mixed gas in the processing container is exhausted by a vacuum pump or the like in order to terminate the etching process.

[0110] (Second dry etching method using etching apparatus)

[0111] The second dry etching method can be used, for example, Figure 1 The etching device shown in the figure is used to implement the above method. Figure 1 The second dry etching method is specifically described by taking the etching device as an example.

[0112] In the second dry etching method, an etching gas B containing a gas containing a halogen atom in its molecule is brought into contact with a film to be etched, and then an etching gas C containing β-diketone is brought into contact with the film to be etched.

[0113] First, the object 10 to be processed, on which an etching film including a metal, an oxide of the metal, or a nitride of the metal is formed, is placed on the placement portion 111 in the processing container 110. Next, the processing container 110, the pipe 121, the pipes 131 and 132, the pipes 141 and 142, the pipes 151 and 152, the liquid nitrogen cold trap 194, and the pipes 191 and 192 are evacuated to a predetermined pressure by the vacuum pump 193, and then the object 10 to be processed is heated by the heating unit 190.

[0114] After the object 10 to be processed reaches a predetermined temperature, first, an additive gas as an etching gas B is supplied from the additive gas supply unit 140 to the pipe 121 at a predetermined flow rate. It should be noted that the inert gas can be supplied from the inert gas supply unit 150 to the pipe 121 at a predetermined flow rate. In addition, an oxidizing gas can also be supplied from an oxidizing gas supply unit (not shown) to the pipe 121 at a predetermined flow rate. While the additive gas as the etching gas B or the additive gas and the inert gas are introduced into the processing container 110, the pressure in the processing container 110 is controlled to a predetermined pressure. By introducing the etching gas B into the processing container 110 for a predetermined time, the additive gas is adsorbed on the film to be etched.

[0115] The etching gas B containing the additive gas is vacuum-exhausted, and then the β-diketone gas as the etching gas C is supplied to the pipe 121 from the β-diketone gas supply unit 130 at a predetermined flow rate. It should be noted that the inert gas can be supplied to the pipe 121 at a predetermined flow rate from the inert gas supply unit 150. While the β-diketone gas as the etching gas C or the β-diketone gas and the inert gas are introduced into the processing container 110, the pressure in the processing container 110 is controlled to be a predetermined pressure. By introducing the etching gas C into the processing container 110 for a predetermined time, the above-mentioned etched film can be etched.

[0116] In the second dry etching method of the present disclosure, the first etching step of introducing the additive gas into the processing container 110 and the second etching step of introducing the β-diketone gas into the processing container 110 can be regarded as one cycle, and the process of this one cycle can be repeated multiple times.

[0117] In the second dry etching method disclosed in the present invention, the thickness of the etched film that can be etched in one cycle can be controlled by setting the etching conditions of one cycle to specified conditions. Therefore, the etching thickness can be precisely controlled by setting the thickness of the etched film that can be etched in one cycle to be thinner.

[0118] In the second dry etching method disclosed herein, it is preferred that the second etching process is performed after the first etching process. In addition, it is preferred that a process of giving a reduced pressure state to the processing container or a process of replacing the processing container with an inactive gas is performed in each cycle. The process of giving a reduced pressure state to the processing container or a process of replacing the processing container with an inactive gas may be performed after the first etching process.

[0119] It should be noted that the second dry etching method can also be carried out without plasma, and during etching, the etching gas can be excited without using plasma. The flow rate of the β-diketone gas and the additional gas can be appropriately set based on the volume and pressure of the processing container.

[0120] As described above, in the second dry etching method using the etching apparatus, the gas can be brought into contact with the film to be etched without being in a plasma state, and dry etching can be performed without generating the gas plasma.

[0121] After the etching process is completed, the heating by the heating unit 190 is stopped to cool down, and the vacuum pump 193 is stopped to replace the vacuum with an inert gas to open the vacuum. In this way, the etching target film can be etched.

[0122] (Etching Conditions of the Second Dry Etching Method)

[0123] In the second dry etching method, the temperature of the film to be etched during the first etching step and the temperature of the film to be etched during the second etching step may be a temperature at which the complex can be vaporized, preferably 50° C. to 350° C., more preferably 50° C. to 300° C., and further preferably 200° C. to 300° C. If the temperature is within the above range, the etching efficiency is high and the damage to the substrate is small.

[0124] When etching gas B contacts the film to be etched and when etching gas C contacts the film to be etched, the pressure in the processing container where the object to be processed having the film to be etched is placed is not particularly limited, but is usually greater than 0.1 kPa and less than 101.3 kPa.

[0125] From the viewpoint of obtaining a sufficient etching rate, the pressure in the processing container during the first etching step and the pressure in the processing container during the second etching step are preferably greater than 2.67 kPa and less than 39.9 kPa, and more preferably greater than 2.67 kPa and less than 26.7 kPa.

[0126] The processing time of the first etching step and the second etching step is not particularly limited, and the processing time of one cycle of the first etching step is preferably within 60 minutes, and the processing time of one cycle of the second etching step is preferably within 60 minutes. Here, the etching processing time refers to the time from the introduction of etching gas into the processing container where the object to be processed is placed until the etching gas in the processing container is exhausted by a vacuum pump or the like in order to end the etching process.

[0127] [Method for manufacturing semiconductor device I]

[0128] The dry etching method I disclosed above can be used as an etching method for forming a predetermined pattern on an indium oxide, gallium oxide, or other film of an existing semiconductor device. By etching an indium oxide film, a gallium oxide film, or the like on a substrate using the dry etching method I disclosed above, a semiconductor device can be manufactured at a low cost.

[0129] The manufacturing method of the semiconductor device disclosed in the present invention is characterized in that it includes the following steps: applying the above-mentioned dry etching method I to a film on a substrate to etch the above-mentioned film, wherein the film contains the above-mentioned metal, the oxide of the above-mentioned metal, or the nitride of the above-mentioned metal.

[0130] The step of etching the film by reacting β-diketone and a gas containing a halogen atom in its molecule can be performed by the dry etching method I of the present disclosure.

[0131] [Cleaning method]

[0132] The cleaning method disclosed herein is characterized in that: the deposited matter deposited on the surface of a processing container of a substrate processing device is removed by bringing the deposited matter into contact with β-diketone and a gas containing halogen atoms in the molecule, wherein the deposited matter contains at least one metal selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, oxides of the above metals or nitrides of the above metals.

[0133] The conditions or sequence for bringing β-diketone and a gas containing halogen atoms in its molecules into contact with the processing container of the above-mentioned substrate processing device and the attached substances deposited on the surface of the processing container, and the attached substances, are the same as the conditions or sequence for bringing β-diketone and a gas containing halogen atoms in its molecules into contact with the etched film and the etched film in the above-mentioned dry etching method I.

[0134] In the cleaning method disclosed herein, the β-diketone in a plasma state and the gas containing halogen atoms in the molecule can be brought into contact with the attached matter, or the β-diketone and the gas containing halogen atoms in the molecule can be brought into contact with the attached matter without being in a plasma state. The temperature of the attached matter when contacting the gas is not particularly limited, and is, for example, 50° C. or higher and 350° C. or lower.

[0135] <Dry Etching Method II>

[0136] The dry etching method II disclosed in the present invention is to etch a film to be formed on the surface of a processed object by contacting it with β-diketone and a gas containing chlorine atoms in the molecule, wherein the film to be etched contains: a metal containing at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two of the metals contain at least one of Ga, Sn or Zn, an oxide of the above metals or a nitride of the above metals.

[0137] For example, when β-diketone and NO2 as an additive gas are brought into contact with an InGaZnO4 film or the like, the composition of the etched film sometimes changes before and after etching. The reason for this is believed to be that Zn reacts with β-diketone from a low temperature, so there is less of it in the film after etching, and Sn, Ga, etc. have low reactivity with β-diketone, so there are more of it in the film after etching. The dry etching method II disclosed in the present invention uses a gas containing chlorine atoms in its molecules as an additive gas among gases containing halogen atoms in their molecules, thereby providing a dry etching method for an etched film containing Ga, Sn or Zn, in which the composition of the etched film is not easily changed before and after etching.

[0138] The metal, metal oxide or metal nitride contained in the etched film etched by the dry etching method II of the present disclosure contains at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two include at least one of Ga, Sn or Zn. As such metal, metal oxide or metal nitride, it is preferably selected from the group consisting of indium gallium zinc oxide [In a Ga b Zn c O d (a and b are respectively greater than 1 and less than 3, c is greater than 0.5 and less than 4, d is greater than 4 and less than 10, referred to as "IGZO"), particularly preferably InGaZnO4, In2Ga2ZnO7 (InGaO3) a (ZnO) c [represents] at least one of the group consisting of indium zinc oxide, aluminum zinc oxide, gallium zinc oxide, indium gallium zinc tin oxide, indium tin zinc oxide, indium tin oxide, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

[0139] In the dry etching method II of the present disclosure, the object to be processed can be the same as that exemplified in the dry etching method I, and the same surface treatment can be performed. The method for forming the etched film and the thickness of the etched film can also be the same as those in the dry etching method I.

[0140] The dry etching method II of the present disclosure uses β-diketone and a gas containing chlorine atoms in the molecule as etching gas.

[0141] The type of β-diketone may be the same as exemplified in the dry etching method I.

[0142] The type of gas containing chlorine atoms in the molecule is not particularly limited, but is preferably at least one selected from the group consisting of HCl, Cl 2 , BCl 3 and SiCl 4 , and more preferably HCl, Cl 2 and BCl 3 .

[0143] The dry etching method II disclosed in the present invention preferably allows β-diketone and a gas containing chlorine atoms in the molecule to contact the film to be etched without plasma. The reason is that if the object to be processed is a semiconductor device substrate, the substrate may be electrically damaged by the plasma gas if it contacts the plasma gas.

[0144] [Third dry etching method]

[0145] Hereinafter, the third dry etching method in which the above-mentioned β-diketone and a gas containing chlorine atoms in the molecule (additive gas) are simultaneously brought into contact with the etched film in the dry etching method II of the present disclosure will be described. In the third dry etching method, an etching gas D containing the above-mentioned β-diketone and the additive gas is brought into contact with the above-mentioned etched film. The etching gas D contains at least β-diketone and a gas containing chlorine atoms in the molecule.

[0146] The amount of β-diketone contained in the etching gas D is preferably 5% by volume or more and 99% by volume or less, and more preferably 10% by volume or more and 90% by volume or less. If the proportion of β-diketone in the etching gas D is too small, the etching rate tends to decrease, and if it is too large, the etching gas becomes too expensive. In addition, when the additive gas in the etching gas D is too little or too much, etching is difficult to proceed.

[0147] The amount of the additive gas (gas containing chlorine atoms in its molecules) contained in the etching gas D is preferably 0.1% by volume or more and 65% by volume or less, and more preferably 1% by volume or more and 60% by volume or less.

[0148] The volume ratio of β-diketone and added gas (gas containing chlorine atoms in its molecules) contained in the etching gas D can be β-diketone:added gas = 1:0.01 or more and 100 or less, or β-diketone:added gas = 1:0.01 or more and 10 or less, or β-diketone:added gas = 1:0.01 or more and 1 or less.

[0149] When the film to be etched is indium gallium zinc oxide, the amount of the gas containing chlorine atoms in the molecule contained in the etching gas D is preferably 2 volume % to 30 volume %, more preferably 2 volume % to 17 volume %.

[0150] When the film to be etched is indium tin oxide, the ratio of the gas containing chlorine atoms in the molecule contained in the etching gas D is preferably 1% by volume to 50% by volume, more preferably 1% by volume to 30% by volume.

[0151] When the film to be etched is indium zinc oxide, the ratio of the gas containing chlorine atoms in the molecule contained in the etching gas D is preferably 20 volume % to 60 volume %, more preferably 40 volume % to 60 volume %.

[0152] When the film to be etched is aluminum gallium nitride, the ratio of the gas containing chlorine atoms in the molecules contained in the etching gas D is preferably 10% by volume to 50% by volume, more preferably 15% by volume to 40% by volume.

[0153] The etching gas D may further contain an oxidizing gas, and may further contain an inert gas.

[0154] The types of the oxidizing gas and the inert gas, and the content ratios of these gases in the etching gas D are the same as those in the etching gas A in the first dry etching method.

[0155] The third dry etching method preferably places the above-mentioned object to be processed in a processing container and performs etching. The third dry etching method preferably performs a step of reducing the pressure in the processing container after the etching gas D contacts the film to be etched. The reason is that byproducts generated during etching can be removed.

[0156] In the third dry etching method, it is preferable to perform a step of replacing the inside of the processing container with an inert gas after the etching gas D contacts the film to be etched. The reason is that byproducts generated during etching can be removed.

[0157] The third dry etching method may perform a step of replacing the inside of the processing container with an inert gas after performing the step of providing the inside of the processing container with a reduced pressure state.

[0158] [Fourth dry etching method]

[0159] Next, a fourth dry etching method as the dry etching method II of the present disclosure is described, and the fourth dry etching method comprises: a third etching step of bringing the etching gas E containing the gas containing chlorine atoms in the molecules into contact with the film to be etched; and a fourth etching step of bringing the etching gas F containing the β-diketone into contact with the film to be etched. The etching gas E contains at least a gas containing chlorine atoms in the molecules (additive gas), and the etching gas F contains at least β-diketone.

[0160] The etching gas E may contain only the additive gas, the etching gas F may contain only β-diketone, and the etching gas E and / or the etching gas F may further contain the oxidizing gas and the inactive gas.

[0161] The content of the additional gas contained in the etching gas E can be set to, for example, 10 volume % or more and 100 volume % or less. The content of β-diketone contained in the etching gas F can be set to 10 volume % or more and 100 volume % or less.

[0162] The types of oxidizing gases and inactive gases contained in etching gas E and / or etching gas F, the contents of these gases in etching gas E, and the contents of these gases in etching gas F are the same as those of etching gas B and etching gas C in the second dry etching method.

[0163] The fourth dry etching method preferably places the above-mentioned object to be processed in a processing container and performs etching. The fourth dry etching method preferably performs a step of giving a reduced pressure state in the processing container after the etching gas E and the etching gas F contact the film to be etched. The reason is that byproducts generated during etching can be removed.

[0164] The fourth dry etching method preferably includes a step of replacing the inside of the processing container with an inert gas after the etching gas E and the etching gas F are brought into contact with the film to be etched. This is because byproducts generated during etching can be removed.

[0165] The fourth dry etching method may perform a step of replacing the inside of the processing container with an inert gas after performing the step of providing the inside of the processing container with a reduced pressure state.

[0166] In the fourth dry etching method disclosed herein, the above process can be repeated multiple times in order to repeatedly etch the etched film. In one cycle of the etching process, the etched film can be etched to a certain thickness, so by limiting the number of cycles, a layer of a desired thickness can be precisely etched.

[0167] (Etching Conditions of the Third Dry Etching Method)

[0168] The third dry etching method can be used, for example, Figure 1 In the third dry etching method, the temperature of the film to be etched during etching can be any temperature at which the complex can be vaporized, preferably 50°C to 350°C, more preferably 50°C to 300°C, further preferably 100°C to 300°C, and particularly preferably 150°C to 300°C.

[0169] The pressure in the processing container during etching is not particularly limited, but is usually 0.1 kPa to 101.3 kPa.

[0170] From the viewpoint of obtaining a sufficient etching rate, the pressure in the processing container during etching is preferably 2.67 kPa to 39.9 kPa, and more preferably 2.67 kPa to 26.7 kPa.

[0171] The other etching conditions of the third dry etching method can be the same as the etching conditions of the first dry etching method.

[0172] (Etching Conditions of the Fourth Dry Etching Method)

[0173] The fourth dry etching method can be used, for example, Figure 1 This is achieved by the etching device shown.

[0174] In the fourth dry etching method, the temperature of the etched film during the third etching process and the temperature of the etched film during the fourth etching process only need to be a temperature at which the complex can be vaporized, and are preferably above 50°C and below 350°C, more preferably above 50°C and below 300°C, further preferably above 100°C and below 300°C, and particularly preferably above 150°C and below 300°C.

[0175] When etching gas E contacts the film to be etched and when etching gas F contacts the film to be etched, the pressure in the processing container where the object to be processed having the film to be etched is placed is not particularly limited, but is usually greater than 0.1 kPa and less than 101.3 kPa.

[0176] From the viewpoint of obtaining a sufficient etching rate, the pressure in the processing container during the third etching step and the pressure in the processing container during the fourth etching step are preferably greater than 2.67 kPa and less than 39.9 kPa, and more preferably greater than 2.67 kPa and less than 26.7 kPa.

[0177] The other etching conditions of the fourth dry etching method can be the same as the etching conditions of the first etching step and the second etching step of the second dry etching method.

[0178] [Method for manufacturing semiconductor device II]

[0179] The dry etching method II of the present disclosure can be used as an etching method for forming a predetermined pattern on a metal oxide film such as InGaZnO4. By etching the InGaZnO4 film or the like on a substrate using the dry etching method II of the present disclosure, a semiconductor device can be manufactured at low cost.

[0180] The manufacturing method II of the semiconductor device disclosed in the present invention is characterized in that it includes the following steps: applying the above-mentioned dry etching method II to a film on a substrate to etch the above-mentioned film, wherein the film contains: metals containing at least 2 selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn and the above-mentioned at least 2 containing at least one of Ga, Sn or Zn, oxides of the above-mentioned metals or nitrides of the above-mentioned metals.

[0181] The step of etching the film by reacting β-diketone and a gas containing a chlorine atom in its molecule can be performed by the dry etching method II of the present disclosure.

[0182] Example

[0183] Hereinafter, examples of the present disclosure are given together with comparative examples, but the present disclosure is not limited to the following examples.

[0184] (Example 1)

[0185] use Figure 1 The etching device 100 shown etches a processing object 10, wherein the processing object 10 has an etched film, and the etched film includes an indium oxide (In2O3) film (shape 1cm×1cm, film thickness 100nm) formed on the surface of a silicon wafer (shape 1cm×1cm, thickness 1000μm).

[0186] The inside of the processing container 110, the pipe 121, the pipes 131 and 132, the pipes 141 and 142, the pipes 151 and 152, the pipes 191 and 192, and the liquid nitrogen cold trap 194 are evacuated to a pressure lower than 10 Pa by the vacuum pump 193. Then, the object 10 placed on the placement portion 111 is heated by a heater (not shown) provided inside the heating unit 190 and the placement portion 111. After confirming that the temperature of the object 10 has reached 250° C., HFAc gas is supplied from the β-diketone gas supply portion 130 and HF gas is supplied from the additional gas supply portion 140 to the pipe 121 at a predetermined flow rate, thereby introducing the etching gas into the processing container 110 while controlling the pressure in the processing container 110 to 13.3 kPa, thereby performing the etching process. The temperature of the object 10 is set to 250° C., and the flow rates of the etching gas are set to HFAc=9 sccm and HF=1 sccm. After 20 minutes from the start of the introduction of the etching gas, the introduction of the etching gas was stopped. After that, the interior of the processing container 110 was evacuated to less than 10 Pa, replaced with N2 gas supplied from the inert gas supply unit 150, and then the processed object 10 was taken out, the film thickness was measured, and the etching rate was evaluated. The results are shown in Table 1.

[0187] (Example 2, Comparative Examples 1 to 5)

[0188] Table 1 below shows the types and flow rates of the additional gas, oxidizing gas, and inert gas, the pressure in the processing container, the temperature during etching, and the etching rate.

[0189] The differences between Example 1 and Example 2 and Comparative Examples 1 to 5 are described. In Example 2, the temperature was changed and set to 300°C. In Comparative Example 1, NO was used as an oxidizing gas instead of HF, in Comparative Example 2, O2 was used instead of HF, in Comparative Examples 3 and 4, NO2 was used instead of HF, and in Comparative Example 5, NO and NO2 were used instead of HF. It should be noted that in Comparative Examples 1 to 5, the flow rate of HFAc was set to 10 sccm, and the temperature was changed to the temperature described in Table 1. In addition, the flow rate of the added gas and the pressure in the processing container are as described in Table 1. The difference between Comparative Example 3 and Comparative Example 4 lies in the temperature. For other aspects, the same operations as in Example 1 were performed, and the etching rate of the etched film was evaluated. The results are shown in Table 1.

[0190] (Examples 3 to 14, Comparative Examples 6 to 23)

[0191] use Figure 1 The etching device 100 shown in the figure performs etching on a target object, wherein the target object has: a gallium oxide (Ga2O3) film with a film thickness of 100 nm formed on the surface of a silicon wafer, an indium gallium zinc oxide (InGaZnO4) film with a film thickness of 10 nm formed on the surface of a silicon wafer, a gallium nitride (GaN) film with a film thickness of 3.4 μm formed on the surface of a sapphire wafer, a tantalum (Ta) film with a film thickness of 50 nm formed on the surface of a silicon wafer, and an indium tin oxide (In2O3:SnO2=9:1, referred to as InSnO4 in the following Table 1) with a film thickness of 100 nm formed on the surface of a silicon wafer. x ) film, a hafnium oxide (HfO2) film with a thickness of 60nm formed on the surface of the silicon wafer, and a zirconium oxide (ZrO2) film with a thickness of 60nm formed on the surface of the silicon wafer.

[0192] The same operation as in Example 1 was performed except that the material of the etched film, the type and flow rate of β-diketone during etching, the type and flow rate of the added gas, oxidizing gas, and inert gas, the pressure in the processing container, and the temperature of the etched film during etching were changed to those shown in Table 1, and the etching rate of the etched film was evaluated. The results are shown in Table 1.

[0193] [Table 1]

[0194]

[0195] If Example 1 is compared with Comparative Example 3, it can be seen that when NO2 is used instead of HF, the etching rate of the In2O3 film at 250°C is low, and when HF is used, the etching rate of the In2O3 film at 250°C is improved. If Example 2 is compared with Comparative Examples 1 and 2, it can be seen that when NO or O2 is used instead of HF, the etching rate of the In2O3 film at 300°C is low, and when HF is used, the etching rate of the In2O3 film at 300°C is improved. In addition, if Example 2 is compared with Comparative Examples 4 and 5, the etching rate of the In2O3 film when NO2 is used instead of HF is 0.5 nm / min, the etching rate of the In2O3 film when NO and NO2 are used instead of HF is 1.5 nm / min, and the etching rate when HF is used is 2.1 nm / min, so it can be seen that when HF is used, the etching rate of the In2O3 film at 300°C is improved.

[0196] If Example 3 is compared with Comparative Example 8, it can be seen that when NO2 is used instead of HF, the etching rate of the Ga2O3 film at 250°C is low, and when HF is used, the etching rate of the Ga2O3 film at 250°C is improved. If Example 3 is compared with Comparative Example 10, the etching rate of Ga2O3 at 250°C when NO and NO2 are used instead of HF is 0.4 nm / min, and when HF is used, the etching rate of the Ga2O3 film at 250°C is 1.6 nm / min, which shows that the etching rate is increased by about 4 times by using HF. If Example 4 is compared with Comparative Examples 6 and 7, it can be seen that when NO or O2 is used instead of HF, the etching rate of the Ga2O3 film at 300°C is low, and when HF is used, the etching rate of the Ga2O3 film at 300°C is improved. In addition, if Example 4 is compared with Comparative Examples 9 and 11, the etching rate of the Ga2O3 film when NO2 is used instead of HF is 1.0 nm / minute at 300°C, the etching rate of the Ga2O3 film when NO and NO2 are used instead of HF is 7.4 nm / minute at 300°C, and the etching rate when HF is used is 10.1 nm / minute at 300°C. It can be seen that when HF is added, the etching rate of the Ga2O3 film at 300°C is increased.

[0197] When Example 5 is compared with Comparative Example 14, it can be seen that when NO2 is used instead of HF, the etching rate of the InGaZnO4 film at 250°C is low, and when HF is used, the etching rate of the InGaZnO4 film at 250°C is improved. When Example 6 is compared with Comparative Examples 12 and 13, it can be seen that when NO or O2 is used instead of HF, the etching rate of the InGaZnO4 film at 300°C is low, and when HF is used, the etching rate of the InGaZnO4 film is improved. In addition, if Example 6 is compared with Comparative Examples 15 and 16, the etching rate of the InGaZnO4 film when NO2 is used instead of HF is 2.4 nm / minute at 300°C, the etching rate of the InGaZnO4 film when NO and NO2 are used instead of HF is 5.8 nm / minute at 300°C, and when HF is used, the etching rate of the InGaZnO4 film at 300°C is 7.1 nm / minute. It can be seen that when HF is used, the etching rate of the InGaZnO4 film at 300°C is improved.

[0198] If Example 8 is compared with Comparative Examples 17 and 18, it can be seen that when NO or O2 is used instead of HF, the etching rate of the GaN film at 300°C is low, and when HF is used, the etching rate of the GaN film at 300°C is improved. In addition, if Example 8 is compared with Comparative Examples 19 and 20, the etching rate of the GaN film at 300°C when NO2 is used instead of HF is 0.2nm / min, the etching rate of the GaN film at 300°C when NO and NO2 are used as additive gases instead of HF is 0.3nm / min, and when HF is used, the etching rate of the GaN film at 300°C is 1.1nm / min, so it can be seen that when HF is used, the etching rate of the GaN film at 300°C is improved.

[0199] For In2O3 and InGaZnO4, it is known that the etching rate is low when O2 and NO2 are added at a temperature of 250°C, while the etching rate is increased in the HF addition system. In addition, it is also confirmed that the etching rate is the fastest when HF is added at each temperature. In this way, by using β-diketone and HF, it is possible to perform etching or increase the etching rate in a temperature range that has been impossible to etch so far.

[0200] It can be seen that in Examples 9 to 12, when HFAc and HF are used, the etching rate of the Ta film at 200°C or 250°C is improved. If Example 11 is compared with Comparative Example 21, it can be seen that when O2 is used without using an additive gas, the etching rate of the Ta film at 200°C is low, and when HF and O2 are used as additive gases, the etching rate of the Ta film at 200°C is improved. If Example 12 is compared with Comparative Example 22, it can be seen that when O2 is used without using an additive gas, the etching rate of the Ta film at 250°C is low, and when HF and O2 are used as additive gases, the etching rate of the Ta film at 250°C is improved. In addition, when comparing Example 9 with Example 11, the etching rate of the Ta film at 200°C is 0.6 nm / min when HF as an additive gas and N2 as an inert gas are used, and the etching rate of the Ta film at 200°C is 2.3 nm / min when HF and O2 as an oxidizing gas are used. It can be seen that when HF and O2 as an oxidizing gas are used simultaneously, the etching rate of the Ta film at 200°C is improved. Similarly, when comparing Example 10 with Example 12, it can be seen that when HF and O2 are used simultaneously, the etching rate of the Ta film at 250°C is also improved.

[0201] Comparing Example 13 with Comparative Example 23, it can be seen that when NO2 is used instead of HF, InSnO x The etching rate of the film is low, and when HF is used, InSnO x When comparing Example 13 with Example 14, the etching rate of InSnOx The etching rate of the film was 0.9 nm / min at 200°C, and the InSnO x The etching rate of the film at 200°C is 2.1 nm / min. It can be seen that when HCl is added, the etching rate of InSnO at 200°C is 2.1 nm / min. x The etching rate of the film is increased.

[0202] (Example 15)

[0203] use Figure 1 The etching device 100 shown etches a processing object 10, wherein the processing object 10 has an etched film, and the etched film includes an indium oxide (In2O3) film (shape 1cm×1cm, film thickness 100nm) formed on the surface of a silicon wafer (shape 1cm×1cm, thickness 1000μm).

[0204] The inside of the processing container 110, the piping 121, the piping 131 and 132, the piping 141 and 142, the piping 151 and 152, the piping 191 and 192, and the liquid nitrogen cold trap 194 are evacuated by the vacuum pump 193 until the pressure is lower than 10Pa. Then, the object 10 placed on the placement part 111 is heated by the heater (not shown) provided inside the heating unit 190 and the placement part 111. After confirming that the temperature of the object 10 reaches 200°C, F2 gas is supplied from the additional gas supply part 140 to the piping 121 at a predetermined flow rate, thereby introducing F2 gas into the processing container 110 while controlling the pressure in the processing container 110 to 12.0kPa, and performing the first etching process. The temperature of the object 10 is set to 200°C, and the flow rate of the etching gas is set to F2 gas = 10sccm. After 5 minutes after the introduction of F2 gas, the supply of F2 gas is stopped. Afterwards, the interior of the processing container 110 is evacuated to less than 10Pa. Next, the HFAc gas is supplied from the β-diketone gas supply unit 130 to the pipe 121 at a specified flow rate, thereby introducing the etching gas into the processing container 110 while controlling the pressure in the processing container 110 to 12.0kPa, and performing the second etching process. The temperature of the processed body 10 is set to 200°C, and the flow rate of the HFAc gas is set to HFAc=10sccm. After the introduction of HFAc is started and 5 minutes have passed, the introduction of the HFAc gas is stopped. Afterwards, the interior of the processing container 110 is evacuated to less than 10Pa. After the first etching process and the second etching process are repeated 10 times, the interior of the processing container 110 is replaced with N2 gas supplied from the inert gas supply unit 150, and then the processed body 10 is taken out, the film thickness is measured, and the etching rate is evaluated. The results are shown in Table 2.

[0205] (Examples 16 to 20, Comparative Examples 24 to 27)

[0206] The same operation as in Example 15 was performed except that the etching gas type and the temperature of the film to be etched during etching were changed as shown in Table 2, and the etching rate of the film to be etched was evaluated.

[0207] The differences between Example 15 and Examples 16 to 20 and Comparative Examples 24 to 27 are described. In Example 16, the gas flowing in the first etching process is changed to ClF3. In Example 17, the gas flowing in the first etching process is changed to HCl. The difference between Examples 15 to 17 and Examples 18 to 20 is the temperature. In Comparative Examples 24 and 26, the gas flowing in the first etching process is set to O2, and in Comparative Examples 25 and 27, it is set to NO. The difference between Comparative Example 24 and Comparative Example 26 is the temperature. The difference between Comparative Example 25 and Comparative Example 27 is the temperature. For other aspects, the same operations as in Example 15 are performed, and the etching rate of the etched film is evaluated. The results are shown in Table 2.

[0208] [Table 2]

[0209]

[0210] If Example 15 is compared with Comparative Examples 24 and 25, it can be seen that when the gas used in the first etching process is set to O2 and NO, the etching rate of the In2O3 film is low, and when F2 is used, the etching rate of the In2O3 film is improved at 200° C. If Example 18 is compared with Comparative Examples 26 and 27, it can be seen that at 250° C., the etching rate of the In2O3 film is low when the gas used in the first etching process is set to O2 and NO, and the etching rate of the In2O3 film is improved when F2 is used. Comparing Examples 15, 16, and 17, when the gas used in the first etching process is F2, the etching rate of the In2O3 film is 0.2 nm / cycle at 200°C, when ClF3 is used, it is 0.3 nm / cycle at 200°C, and when the gas used in the first etching process is set to HCl, the etching rate of the In2O3 film is 1.1 nm / cycle at 200°C. It can be seen that when the gas used in the first etching process is set to HCl, the etching rate of the In2O3 film at 200°C is improved. Comparing Examples 15 to 17 with Examples 18 to 20, regardless of whether the gas used in the first etching process is F2, ClF3, or HCl, the etching rate at 250°C is improved compared to 200°C.

[0211] (Example 21)

[0212] use Figure 1The etching device 100 shown etches the object 10 to be processed, wherein the object 10 to be processed has an etched film, and the etched film includes an In2Ga2ZnO6 film (shape 1cm×1cm, film thickness 100nm) formed on the surface of a silicon wafer (shape 1cm×1cm, thickness 1000μm).

[0213] The interior of the processing container 110, the piping 121, the piping 131 and 132, the piping 141 and 142, the piping 151 and 152, the piping 191 and 192, and the liquid nitrogen cold trap 194 are evacuated to a pressure lower than 10 Pa. Then, the object 10 placed on the placement portion 111 is heated by a heater (not shown) provided inside the heating unit 190 and the placement portion 111. After confirming that the temperature of the object 10 reaches 200° C., hexafluoroacetylacetone (HFAc) gas is supplied from the β-diketone gas supply portion 130 and HCl gas is supplied from the additional gas supply portion 140 to the piping 121 at a predetermined flow rate, thereby introducing the etching gas into the processing container 110 while controlling the pressure in the processing container 110 to 1.33 kPa, thereby performing the etching process. The temperature of the processed object 10 is set to 200°C, and the gas composition ratio of the etching gas is set to HFAc:HCl=96:4 by volume ratio. The etching gas is introduced and after 5 minutes, the introduction of the etching gas is stopped. Thereafter, the interior of the processing container 110 is evacuated to less than 10Pa, and replaced with N2 gas supplied from the inert gas supply unit 150, and then the processed object 10 is taken out, the film thickness is measured, and the etching rate and the elemental composition ratio of the film surface after etching are evaluated. It should be noted that the elemental composition is analyzed by X-ray photoelectron spectroscopy (XPS) (manufactured by ULVAC-PHI, PHI5000 VersaProbeII). The results are shown in Table 3.

[0214] (Examples 22 to 26, Comparative Examples 28 to 30)

[0215] Table 3 below shows the type of additive gas during etching, the flow rate of each additive gas, the pressure in the processing container, the temperature during etching, the etching rate, and the element composition ratio before and after etching in Examples 21 to 26 and Comparative Examples 28 to 30.

[0216] The differences between Example 21 and Examples 22 to 26 and Comparative Examples 28 to 30 are described. In Example 22 and Comparative Example 28, the gas composition of the etching gas was changed, and was set to HFAc:HCl=90:10 in Example 22 and HFAc:HCl=100:0 in Comparative Example 28. In Example 23, the temperature was changed and set to 300°C. In Example 24, the pressure in the container was set to 13.3 kPa, and the temperature was set to 175°C. In Example 25, the gas composition ratio of the etching gas was set to HFAc:HCl=85:15, the pressure in the container was set to 0.66 kPa, and the temperature was set to 275°C. In Example 26, Cl2 gas was used instead of HCl, in Comparative Example 29, O2 was used instead of HCl, and in Comparative Example 30, NO2 was used instead of HCl. It should be noted that in Comparative Examples 29 and 30, the amount of HFAc in the etching gas was set to 67% by volume, and the pressure and temperature in the container were changed to the pressure and temperature described in Table 3. The same operation as in Example 21 was carried out with respect to other matters, and the etching rate and element composition ratio of the etched film were evaluated.

[0217] (Examples 27 to 33)

[0218] use Figure 1 The etching device 100 shown in the figure etches the object to be processed, wherein the object to be processed has: In9SnO formed on the surface of the silicon wafer; 15 film (shape 1cm×1cm, film thickness 100nm), In2Zn2O5 film (shape 1cm×1cm, film thickness 100nm) formed on the surface of silicon wafer, AlGa 10 N 10 Film (shape 1cm×1cm, film thickness 1.2μm).

[0219] The same operation as in Example 21 was performed to evaluate the etching rate and element composition ratio of the etched film, except that the material of the etched film, the type and flow rate of β-diketone during etching, the type and flow rate of the added gas, the pressure in the processing container, and the temperature of the processed body during etching were changed as shown in Table 3. The results are shown in Table 3.

[0220] [Table 3]

[0221]

[0222] If Example 21 is compared with Comparative Examples 28 and 29, it can be seen that the etching rate is low when only HFAc is used and when O2 is used instead of HCl, while the etching rate of In2Ga2ZnO6 is improved when it is a mixed gas of HFAc and HCl. It can be seen that in Examples 21, 22 and 25, etching can be performed without changing the composition of In2Ga2ZnO6 when the gas composition is HFAc:HCl=96:4, 90:10 or 85:15. It can be seen that in Example 21 and Examples 23 to 25, if HFAc and HCl are used, the composition of In2Ga2ZnO6 after etching at 175°C, 200°C, 275°C or 300°C does not change. It can also be seen that even if the pressure in the container is 0.66kPa, 1.33kPa or 13.3kPa, the composition of In2Ga2ZnO6 after etching does not change.

[0223] If Example 21 is compared with Comparative Example 30, it can be seen that the element composition ratio after etching in Comparative Example 30 using NO2 instead of HCl is a:b:c:d=3:3:1:6, and In2Ga2ZnO6 can be etched without composition change in Example 21 using HCl. It can be seen that in Examples 21 and 26, even when Cl2 is used instead of HCl, the composition of In2Ga2ZnO6 after etching does not change, and even if the added gas is set to Cl2, the composition change of In2Ga2ZnO6 after etching can be suppressed.

[0224] It can be seen that in Example 27, when HCl is used as the additive gas, the etching of In9SnO 15 It can be seen that in Example 28, even if Cl2 is used instead of HCl as the added gas, In9SnO can be etched. 15 And there is no composition change.

[0225] It can be seen that in Example 29, the composition change of In2Zn2O5 after etching can be suppressed when HCl is used as the additive gas. It can be seen that in Examples 30 and 31, In2Zn2O5 can be etched without composition change even if Cl2 or BCl3 is used as the additive gas instead of HCl.

[0226] It can be seen that in Example 32, when HCl is used as the additive gas, the AlGa 10 N 10 It can be seen that in Example 33, even if Cl2 is used instead of HCl as the additive gas, the etching of AlGa 10 N 10 And there is no composition change.

[0227] Description of Reference Numerals

[0228] 10: Processed object

[0229] 100: Etching device

[0230] 110: Processing Container

[0231] 111: Loading section

[0232] 121: Piping

[0233] 130: β-diketone gas supply unit

[0234] 131, 132: Piping

[0235] 140: Add gas supply

[0236] 141, 142: Piping

[0237] 150: Inert gas supply unit

[0238] 151, 152: Piping

[0239] 190: Heating unit

[0240] 191, 192: Piping

[0241] 193: Vacuum pump

[0242] 194: Liquid nitrogen cold trap

[0243] MFC1, MFC2, MFC3: Flow Conditioning Unit

[0244] PI1, PI2: Pressure gauge

[0245] V1, V2, V3, V4, V5, V6, V7, V8: valves

Claims

1. A dry etching method, wherein a film to be etched formed on a surface of a workpiece is brought into contact with β-diketone and a gas containing a halogen atom in its molecule to perform etching, wherein: The etched film includes: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the metal, or a nitride of the metal.

2. The dry etching method according to claim 1, wherein: The metal, metal oxide or metal nitride is at least one selected from the group consisting of indium oxide, gallium oxide, copper oxide, cobalt oxide, iron oxide, tin oxide, zinc oxide, aluminum oxide, tantalum oxide, indium gallium zinc oxide, indium tin oxide, gallium nitride, indium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

3. The dry etching method according to claim 1, wherein: The gas containing halogen atoms in the molecules is at least one selected from the group consisting of HF, F2, ClF3, IF7, HCl and Cl2.

4. The dry etching method according to claim 1, wherein: The β-diketone is at least one selected from the group consisting of hexafluoroacetylacetone, trifluoroacetylacetone, and acetylacetone.

5. The dry etching method according to claim 1, wherein: The etching is performed without accompanying plasma.

6. The dry etching method according to claim 1, wherein: The etching gas A containing the β-diketone and the gas containing a halogen atom in the molecule is brought into contact with the film to be etched.

7. The dry etching method according to claim 6, wherein: The temperature of the film to be etched when the etching gas A contacts the film to be etched is 50° C. or higher and 300° C. or lower.

8. The dry etching method according to claim 6, wherein: The amount of β-diketone contained in the etching gas A is 10 volume % or more and 90 volume % or less.

9. The dry etching method according to claim 6, wherein: The amount of the gas containing halogen atoms in the molecule contained in the etching gas A is 0.1 volume % or more and 50 volume % or less.

10. The dry etching method according to claim 6, wherein: The etching gas A further includes at least one oxidizing gas selected from the group consisting of O2, NO, NO2 and N2O.

11. The dry etching method according to claim 6, wherein: The etching gas A further includes at least one inert gas selected from the group consisting of N 2 , Ar, He, Ne, and Kr.

12. The dry etching method according to claim 6, wherein: When the etching gas A contacts the film to be etched, the pressure in the processing container in which the object to be processed on which the film to be etched is placed is 0.1 kPa or more and 101.3 kPa or less.

13. The dry etching method according to claim 1, comprising: a first etching step of bringing an etching gas B containing a gas containing halogen atoms in the molecule into contact with the film to be etched; and a second etching step of bringing an etching gas C containing the β-diketone into contact with the film to be etched.

14. The dry etching method according to claim 13, wherein: The temperature of the film to be etched when the etching gas B contacts the film to be etched and the temperature of the film to be etched when the etching gas C contacts the film to be etched are 50° C. or higher and 300° C. or lower.

15. The dry etching method according to claim 13, wherein: The etching gas B and / or the etching gas C further contains at least one oxidizing gas selected from the group consisting of O2, NO, NO2 and N2O.

16. The dry etching method according to claim 13, wherein: The etching gas B and / or the etching gas C further contains at least one inactive gas selected from the group consisting of N 2 , Ar, He, Ne and Kr.

17. The dry etching method according to claim 13, wherein: When the etching gas B contacts the film to be etched and when the etching gas C contacts the film to be etched, the pressure in the processing container where the object to be processed having the film to be etched is placed is 0.1 kPa or more and 101.3 kPa or less.

18. A cleaning method, characterized in that: The deposited matter deposited on the surface of a processing container of a substrate processing device is removed by bringing it into contact with β-diketone and a gas containing halogen atoms in its molecules, wherein the deposited matter includes: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the metal or a nitride of the metal.

19. The cleaning method according to claim 18, wherein: The metal, metal oxide or metal nitride is at least one selected from the group consisting of indium oxide, gallium oxide, copper oxide, cobalt oxide, iron oxide, tin oxide, zinc oxide, aluminum oxide, tantalum oxide, indium gallium zinc oxide, indium tin oxide, gallium nitride, indium nitride, aluminum nitride, tantalum nitride, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

20. The cleaning method according to claim 18, wherein: At least one oxidizing gas selected from the group consisting of O 2 , NO, NO 2 , and N 2 O is further brought into contact with the deposit.

21. A method for manufacturing a semiconductor device, comprising the following steps: applying the dry etching method described in any one of claims 1 to 17 to a film on a substrate to etch the film, wherein the film comprises: a metal containing at least one selected from the group consisting of In, Ga, Cu, Co, Fe, Sn, Zn, Al, Ta and As, an oxide of the metal or a nitride of the metal.

22. A dry etching method, comprising etching a film to be etched formed on a surface of a processed object by contacting it with β-diketone and a gas containing chlorine atoms in its molecule, wherein: The etched film includes: a metal containing at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two of the metals contain at least one of Ga, Sn or Zn, an oxide of the metal or a nitride of the metal.

23. The dry etching method according to claim 22, wherein: The metal, metal oxide or metal nitride is at least one selected from the group consisting of indium gallium zinc oxide, indium zinc oxide, aluminum zinc oxide, gallium zinc oxide, indium gallium zinc tin oxide, indium tin zinc oxide, indium tin oxide, aluminum gallium nitride, indium gallium nitride and indium gallium arsenic.

24. The dry etching method according to claim 22, wherein: The gas containing chlorine atoms in the molecules is at least one selected from the group consisting of HCl, Cl2, BCl3 and SiCl4.

25. The dry etching method according to claim 22, wherein: The β-diketone is at least one selected from the group consisting of hexafluoroacetylacetone, trifluoroacetylacetone, and acetylacetone.

26. The dry etching method according to claim 22, wherein: The etching is performed without accompanying plasma.

27. The dry etching method according to claim 22, wherein: The etching gas D containing the β-diketone and the gas containing chlorine atoms in the molecule is brought into contact with the film to be etched.

28. The dry etching method according to claim 27, wherein: The amount of the gas containing chlorine atoms in its molecules contained in the etching gas D is 1 volume % or more and 60 volume % or less.

29. The dry etching method according to claim 22 comprises: a third etching step of bringing an etching gas E containing a gas having chlorine atoms in its molecules into contact with the film to be etched; and a fourth etching step of bringing an etching gas F containing the β-diketone into contact with the film to be etched.

30. A method for manufacturing a semiconductor device, comprising the following steps: applying the dry etching method described in any one of claims 22 to 29 to a film on a substrate to etch the film, wherein the film comprises: a metal containing at least two selected from the group consisting of In, Co, Fe, As, Al, Ga, Sn and Zn, and the at least two containing at least one of Ga, Sn or Zn, an oxide of the metal or a nitride of the metal.

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