Dry etching method, semiconductor device manufacturing method and cleaning method

Abstract

A dry etching method is provided, capable of selectively etching an object containing at least one metal selected from titanium, indium, and tin at a sufficient etching rate without using plasma. The dry etching method includes a dry etching step in which an etching gas containing a halogen fluoride is brought into contact with a component (12) having the object to be etched, and the object is etched without using plasma. The halogen fluoride is a compound of bromine or iodine and fluorine, and the object to be etched is the object being etched by the etching gas. The object to be etched contains at least one metal selected from titanium, indium, and tin.

Description

Technical Field

[0001] This invention relates to dry etching methods, methods for manufacturing semiconductor devices, and cleaning methods. Background Technology

[0002] Materials containing metals such as titanium (Ti), indium (In), and tin (Sn) are sometimes used as hard masks or electrode materials for semiconductor devices. In order to use materials containing these metals as semiconductor device materials, it is necessary to micro-process these materials into the desired shape. However, most of these materials are difficult to etch and have almost no vapor pressure.

[0003] Therefore, the mainstream approach in the past was to remove the materials containing the aforementioned metals by contacting them with a solution containing oxidants, chelating agents, fluoride ions, etc. (see, for example, Patent Document 1).

[0004] However, if wet etching is used as the etching process for semiconductor devices, parts of the semiconductor device that should not be etched will also be etched, which may result in the loss of the semiconductor device's characteristics.

[0005] On the other hand, dry etching is known as a method for removing materials constituting a semiconductor element from the surface of the semiconductor element or the inner surface of the cavity of a semiconductor element manufacturing apparatus. For example, Patent Document 2 discloses a method for removing metal deposits deposited on the inner surface of a cavity during a process used in manufacturing a semiconductor element. The method disclosed in Patent Document 2 involves simultaneously supplying a halogen gas other than fluorine gas and fluorine gas into the cavity of the semiconductor element manufacturing apparatus to generate a halogen fluoride in the cavity, and then removing the metal deposit by contacting an etching gas containing the halogen fluoride with the metal deposit.

[0006] However, the method disclosed in Patent Document 2 requires high temperatures to generate halogen fluorides, which places a heavy load on the semiconductor device manufacturing equipment. Furthermore, the etching gas becomes a mixture of halogen fluorides and unreacted halogen gases, which may result in insufficient etching speed.

[0007] Prior art literature

[0008] Patent Document 1: Japanese Patent Publication No. 536312, 2008

[0009] Patent Document 2: Japanese Patent Publication No. 267241, 2001 Summary of the Invention

[0010] The objective of this invention is to provide a dry etching method, a method for manufacturing semiconductor devices, and a cleaning method, which can selectively etch an object containing at least one metal selected from titanium, indium, and tin at a sufficient etching rate without using plasma.

[0011] To address the aforementioned issues, one aspect of the present invention is shown in [1] to

[11] .

[0012] [1] A dry etching method comprising a dry etching step, wherein the dry etching step involves contacting an etching gas containing a halogenated fluoride with a component having an object to be etched, and etching the object without using plasma, wherein the halogenated fluoride is a compound of bromine or iodine and fluorine, the object to be etched is an object etched by the etching gas, and the object to be etched contains at least one metal selected from titanium, indium and tin.

[0013] [2] According to the dry etching method described in [1], the halogen fluoride is selected from at least one of bromine monofluoride, bromine trifluoride, bromine pentafluoride, iodine pentafluoride and iodine heptafluoride.

[0014] [3] According to the dry etching method described in [1] or [2], the etching gas is a mixture of the halogen fluoride and the inert gas.

[0015] [4] In any one of the dry etching methods according to [1] to [3], the content of halogen elemental gas contained in the etching gas is less than 5% by volume.

[0016] [5] The dry etching process is carried out at a temperature of 40°C or higher and 250°C or lower according to any one of [1] to [4].

[0017] [6] The dry etching process is carried out at a temperature of 80°C or higher and 150°C or lower according to any one of [1] to [4].

[0018] [7] The dry etching process is carried out under a pressure of 1 Pa or more and 100 kPa or less according to any one of [1] to [6].

[0019] [8] According to any one of [1] to [7], the etched component has a non-etched object and the etched object, wherein the non-etched object is not an object to be etched by the etching gas.

[0020] The non-etched object has at least one selected from copper, nickel, cobalt, and photoresist.

[0021] The etchable object is selectively etched compared to the non-etched object.

[0022] [9] In any one of [1] to [8], the object to be etched is at least one selected from the elemental form of the metal, the oxide of the metal, the nitride of the metal, the nitride of the metal, and the fluoride of the metal.

[0023]

[10] A method for manufacturing a semiconductor element, wherein the semiconductor element is manufactured using any one of [1] to [9] dry etching method.

[0024] The component to be etched is a semiconductor substrate having the object to be etched.

[0025] The manufacturing method includes a processing step in which at least a portion of the object to be etched is removed from the semiconductor substrate by etching.

[0026]

[11] A cleaning method, comprising cleaning the inner surface of the chamber of a semiconductor device manufacturing apparatus by employing the dry etching method described in any one of [1] to [9],

[0027] The component to be etched is the chamber, and the inner surface of the chamber has an adhering substance that is attached during the operation of the semiconductor device manufacturing apparatus; this adhering substance is the object to be etched.

[0028] The cleaning method includes a cleaning step in which the deposits are removed from the inner surface of the chamber by etching.

[0029] According to the present invention, it is possible to selectively etch an object containing at least one metallic element selected from titanium, indium, and tin without using plasma and at a sufficient etching rate. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating an example of an etching apparatus for one embodiment of the dry etching method of the present invention.

[0031] Figure 2 This is a schematic diagram of another example of an etching apparatus illustrating one embodiment of the dry etching method of the present invention.

[0032] Figure 3 This is a diagram illustrating the test pieces used in the embodiments, comparative examples, and reference examples. Detailed Implementation

[0033] The following describes one embodiment of the present invention. Furthermore, this embodiment represents one example of the present invention, and the present invention is not limited to this embodiment. In addition, various modifications or improvements can be made to this embodiment, and such modified or improved methods are also included in the present invention.

[0034] The dry etching method of this embodiment includes a dry etching step in which an etching gas containing a halogen fluoride is brought into contact with a component having an object to be etched, and the object to be etched is etched without the use of plasma. The halogen fluoride is a compound of bromine (Br) or iodine (I) and fluorine (F), and the object to be etched is the object being etched by the etching gas. The object to be etched contains at least one metal selected from titanium (Ti), indium (In), and tin (Sn).

[0035] When the etching gas comes into contact with the object to be etched, the halogen fluorides in the etching gas react with the metal in the object to be etched, generating fluorides of the metal. Since the fluorides of the metal are volatile, the etching of the object is achieved through the volatilization of the fluorides.

[0036] Therefore, the dry etching method according to this embodiment can selectively etch an object containing at least one metal selected from titanium, indium, and tin at a sufficient etching rate without using plasma. That is, the object to be etched can be selectively etched compared to a non-etched object that is not etched by an etching gas. The non-etched object will be described in detail later.

[0037] Furthermore, according to the dry etching method of this embodiment, the object to be etched can be etched without using plasma, thus eliminating the need for an expensive plasma generator. Therefore, etching of the object to be etched can be performed at a low cost. In addition, since plasma is not used, corrosion is less likely to occur in components constituting the etching apparatus (e.g., chambers), piping connected to the etching apparatus, components constituting the semiconductor element manufacturing apparatus (e.g., chambers), and piping connected to the semiconductor element manufacturing apparatus described later.

[0038] The dry etching method of this embodiment can be used for the manufacture of semiconductor devices and the cleaning of the inner surface of the cavity of a semiconductor device manufacturing apparatus.

[0039] That is, the semiconductor element manufacturing method of this embodiment is a semiconductor element manufacturing method that uses the dry etching method of this embodiment to manufacture semiconductor elements. The etched component is a semiconductor substrate having the above-mentioned etchable object. The manufacturing method includes a processing step in which at least a portion of the etchable object is removed from the semiconductor substrate by etching.

[0040] Here is an example of a method for manufacturing a semiconductor device according to this embodiment. This manufacturing method includes a film deposition step, a mask formation step, and a processing step. In the film deposition step, a layer composed of an object to be etched is formed on the surface of a semiconductor substrate. In the mask formation step, a mask with a predetermined pattern is formed on the layer of the object to be etched. In the processing step, the layer of the object to be etched, on which the mask is formed, is etched using the dry etching method of this embodiment. Through the processing step, the portions of the layer of the object to be etched that are not covered by the mask are removed, and the aforementioned pattern is transferred onto the layer of the object to be etched, thus obtaining a semiconductor device.

[0041] Furthermore, the cleaning method of this embodiment is a cleaning method that uses the dry etching method of this embodiment to clean the inner surface of the chamber of a semiconductor device manufacturing apparatus, where the etched component is the chamber. The inner surface of the chamber has deposits that adhere during the operation of the semiconductor device manufacturing apparatus; these deposits are the objects to be etched. Moreover, the cleaning method of this embodiment includes a cleaning step that removes the deposits from the inner surface of the chamber by etching.

[0042] For example, in the film deposition process and / or processing process of an example of the semiconductor device manufacturing method of this embodiment described above, unwanted deposits composed of the object to be etched may sometimes adhere to the inner surface of the cavity where these film deposition and processing processes are performed. Therefore, if the cleaning process is performed at one or both of the time after the film deposition process and the processing process, the deposits can be removed from the inner surface of the cavity by etching.

[0043] The dry etching method, semiconductor device manufacturing method, and cleaning method of this embodiment will be described in more detail below.

[0044] [Halogen fluorides]

[0045] The type of halogen fluoride is not particularly limited as long as it is a compound of bromine or iodine and fluorine, but it is preferably selected from at least one of bromine monofluoride (BrF), bromine trifluoride (BrF3), bromine pentafluoride (BrF5), iodine pentafluoride (IF5), and iodine heptafluoride (IF7). Among these halogen fluorides, from the viewpoint of operability and availability, at least one of bromine pentafluoride and iodine heptafluoride is more preferred.

[0046] [Etching Gas]

[0047] The etching gas is a gas containing halogen fluorides. The etching gas can be a gas consisting solely of halogen fluorides, or it can be a mixture containing halogen fluorides and other types of gases. When the etching gas is a mixture containing halogen fluorides and other types of gases, in order to etch the object at a sufficient etching rate, the content of halogen fluorides in the etching gas is preferably 1% by volume or more, more preferably 5% by volume or more, and even more preferably 10% by volume or more.

[0048] When the etching gas is a mixture containing halogen fluorides and other gases, an inert gas can be used as one of the other gases. That is, the etching gas can be a mixture containing halogen fluorides and an inert gas. As the inert gas, at least one selected from nitrogen (N2), helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) can be used. The content of the inert gas in the etching gas is not particularly limited and can be more than 0% by volume and less than 90% by volume.

[0049] Furthermore, the etching gas may contain halogen gases, such as fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2). However, in order to etch the target object at a sufficient etching rate, the concentration of halogen gases in the etching gas is preferably as low as possible. Specifically, the concentration of halogen gases in the etching gas is preferably less than 5% by volume, more preferably less than 1% by volume, and even more preferably less than 1000 ppm by volume.

[0050] Temperature conditions for dry etching process

[0051] The temperature conditions for the dry etching process in this embodiment are not particularly limited as long as the halogen fluoride can exist in a gaseous state under the pressure during etching, but are preferably 40°C or higher and 250°C or lower, more preferably 45°C or higher and less than 250°C, and even more preferably 50°C or higher and 200°C or lower. Here, the temperature conditions refer to the temperature of the component being etched, but the temperature of the stage inside the etching apparatus can also be used.

[0052] If the temperature is above 40°C, the halogen fluoride can exist in a gaseous state, and the etching rate of the object to be etched can easily become higher. On the other hand, if the temperature is below 250°C, etching can be performed without excessive time and energy, which has the advantages of low load on the etching equipment and semiconductor manufacturing equipment, and suppression of etching of parts that should not be etched (such as non-etchable objects described later).

[0053] [Pressure conditions for dry etching process]

[0054] The pressure conditions of the dry etching process in this embodiment are not particularly limited as long as the halogen fluoride can exist in a gaseous state under the etching pressure, but are preferably 1 Pa or more and 100 kPa or less, more preferably 1 kPa or more and 90 kPa or less, further preferably 2 kPa or more and 80 kPa or less, and particularly preferably 5 kPa or more and 50 kPa or less. The flow rate of the etching gas is appropriately set according to the size of the chamber and the capacity of the exhaust equipment for depressurizing the chamber, so as to maintain a constant pressure in the chamber.

[0055] [Etched object]

[0056] The object to be etched by the etching gas contains at least one metal selected from titanium, indium, and tin, which can be an elemental form of the aforementioned metal or a compound of the aforementioned metal. Alternatively, the object to be etched can be a mixture containing at least one of the aforementioned elemental metals and compounds of the aforementioned metals.

[0057] Examples of mixtures containing at least one of the aforementioned elemental metal and the aforementioned metal compound include alloys of the aforementioned metal and other metals, mixtures of the aforementioned elemental metal and at least one of the aforementioned metal compound with other materials, and mixtures of the aforementioned elemental metal and at least one of the aforementioned metal compound with impurities. These mixtures preferably contain a total of 10 mol% or more of the aforementioned elemental metal and the aforementioned metal compound, more preferably 20 mol% or more, and even more preferably 30 mol% or more.

[0058] Examples of compounds of the metal include oxides of the metal, nitrides of the metal, oxynitrides of the metal, and fluorides of the metal. The oxides, nitrides, oxynitrides, and fluorides of the metal are respectively compounds composed of the metal and oxygen (O), compounds composed of the metal and nitrogen (N), compounds composed of the metal, oxygen and nitrogen atoms, and compounds composed of the metal, oxygen and fluorine atoms. The form of the oxides, nitrides, oxynitrides, and fluorides of the metal is not particularly limited; for example, they can be in the form of films, foils, powders, particles, or blocks.

[0059] The ratio of the metal to oxygen, nitrogen, and fluorine atoms in the aforementioned metal compounds is not particularly limited. The oxides of the aforementioned metals, for example, are composed of M... x O yCompounds represented by (M is at least one metal selected from titanium, indium, and tin, and x and y are each independently integers of 1 or more) are preferably compounds containing 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more of the aforementioned metal. Specifically, examples include compounds represented by MO, M2O3, MO2, MO3, M3O4, and M2O5.

[0060] The metal nitride, for example, is made from M a N b (M is at least one metal selected from titanium, indium, and tin, and a and b are each independently an integer of 1 or more) The compound preferably contains 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more of the aforementioned metal. Specifically, examples include compounds containing MN, M2N, M3N2, M3N4, M4N, M7N3, M... 16 N2 represents the compound.

[0061] The nitride of the metal, for example, is made from M c N d O e The compound represented by (M is at least one metal selected from titanium, indium and tin, and c, d and e are each independently an integer of 1 or more) preferably contains 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more of the metal.

[0062] The fluoride oxide of the metal is, for example, made from M f F g O h The compound represented by (M is at least one metal selected from titanium, indium and tin, and f, g and h are each independently an integer of 1 or more) preferably contains 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more of the metal.

[0063] Halogenated fluorides in the etching gas, such as bromine pentafluoride gas, react with the etch target containing at least one metal selected from titanium, indium, and tin at a predetermined reaction temperature to produce reaction products, such as fluorides presumed to be metals. The presumed structure of the metal fluoride varies depending on the combination of the halogenated fluoride and the etch target; for example, M can be considered. q F r Or M q O s F tetc. Wherein, M is at least one metal selected from titanium, indium, and tin, and q, r, s, and t are each independently an integer greater than 1. The fluorides of the metal have a higher vapor pressure than the elemental form of the metal, the oxide of the metal, the nitride of the metal, the oxynitride of the metal, etc., and therefore volatilize and are removed under the temperature and pressure conditions during etching.

[0064] [Non-etched objects]

[0065] The non-etched object having at least one of copper, nickel, cobalt and photoresist reacts very slowly with halogen fluorides, or the etching hardly occurs because the vapor pressure of the reaction products generated by the reaction with halogen fluorides is low.

[0066] Therefore, when using the dry etching method of this embodiment to etch a component having an etchable object and a non-etchable object, the etchable object can be selectively etched relative to the non-etchable object. Thus, the etching method of this embodiment can utilize methods such as using a patterned non-etchable object as a mask to process the etchable object into a predetermined shape (e.g., processing a film-like etchable object of the etchable component into a predetermined film thickness), and can therefore be appropriately used in the manufacture of semiconductor devices. Furthermore, since the non-etchable object is not etched, it is possible to suppress the etching of portions of the semiconductor device that should not be etched, and to prevent the loss of semiconductor device characteristics due to etching.

[0067] Photoresist refers to a photosensitive composition whose physical properties, such as solubility, change due to light or electron beams. Examples include photoresists for g-lines, h-lines, i-lines, KrF, ArF, F2, and EUV. The composition of a photoresist is not particularly limited as long as it is generally used in semiconductor manufacturing processes. For example, compositions containing polymers synthesized from at least one monomer selected from linear olefins, cyclic olefins, styrene, vinylphenol, (meth)acrylic acid, (meth)acrylates, epoxy resins, melamine, and glycols can be cited. Furthermore, (meth)acrylic acid refers to one or both of acrylic acid and methacrylic acid, and (meth)acrylates refer to one or both of acrylates and methacrylates.

[0068] Next, refer to Figure 1 This section describes an example of an etching apparatus structure capable of implementing the etching method of this embodiment, and an example of a dry etching method using the etching apparatus. Figure 1 The etching apparatus is a plasma-free etching apparatus that does not use plasma. First, for Figure 1 The etching apparatus will be described.

[0069] Figure 1The etching apparatus includes a chamber 10, a stage 11, a thermometer 14, an exhaust pipe 13, a vacuum pump 15, and a pressure gauge 16. The etching is performed inside the chamber 10. The stage 11 supports the etched component 12 inside the chamber 10. The thermometer 14 measures the temperature of the etched component 12. The exhaust pipe 13 is used to exhaust the gas inside the chamber 10. The vacuum pump 15 is located in the exhaust pipe 13 and reduces the pressure inside the chamber 10. The pressure gauge 16 measures the pressure inside the chamber 10.

[0070] in addition, Figure 1 The etching apparatus includes an etching gas supply unit that supplies etching gas to the interior of the chamber 10. This etching gas supply unit comprises a halogen fluoride gas supply unit 1, an inert gas supply unit 2, a halogen fluoride gas supply pipe 5, and an inert gas supply pipe 6. The halogen fluoride gas supply unit 1 supplies halogen fluoride gas, the inert gas supply unit 2 supplies inert gas, the halogen fluoride gas supply pipe 5 connects the halogen fluoride gas supply unit 1 to the chamber 10, and the inert gas supply pipe 6 connects to the inert gas supply unit 2 at the middle of the halogen fluoride gas supply pipe 5.

[0071] Furthermore, the halogen fluoride gas supply pipe 5 is equipped with a pressure gauge 7 for measuring the pressure of the halogen fluoride gas and a halogen fluoride gas flow control device 3 for controlling the flow rate of the halogen fluoride gas. In addition, the inert gas supply pipe 6 is equipped with an inert gas pressure control device 8 for controlling the pressure of the inert gas and an inert gas flow control device 4 for controlling the flow rate of the inert gas.

[0072] Furthermore, when supplying halogenated fluoride gas as an etching gas to the chamber 10, halogenated fluoride gas is supplied to the chamber 10 via the halogenated fluoride gas supply pipe 5 by sending halogenated fluoride gas from the halogenated fluoride gas supply section 1 to the halogenated fluoride gas supply pipe 5.

[0073] Furthermore, when a mixture of halogen fluoride gas and inert gas is supplied as the etching gas, halogen fluoride gas is supplied from the halogen fluoride gas supply unit 1 to the halogen fluoride gas supply pipe 5, and inert gas is supplied from the inert gas supply unit 2 to the halogen fluoride gas supply pipe 5 via the inert gas supply pipe 6. Thus, the halogen fluoride gas and inert gas mix in the middle of the halogen fluoride gas supply pipe 5 to form a mixed gas, which is then supplied to the chamber 10 via the halogen fluoride gas supply pipe 5.

[0074] Furthermore, the structures of the halogen fluoride gas supply unit 1 and the inert gas supply unit 2 are not particularly limited; for example, they can also be gas cylinders or gas storage cylinders. In addition, the halogen fluoride gas flow control device 3 and the inert gas flow control device 4 can be, for example, mass flow controllers or flow meters.

[0075] When supplying etching gas to chamber 10, it is preferable to supply the etching gas at a pressure that is (i.e., the pressure of the etching gas supply) Figure 1 The etching gas is supplied while maintaining the value of the pressure gauge 7 in the chamber at a predetermined value. That is, the supply pressure of the etching gas is preferably 10 Pa or more and 1.0 MPa or less, more preferably 100 Pa or more and 0.5 MPa or less, and even more preferably 500 Pa or more and 0.3 MPa or less. If the supply pressure of the etching gas is within the above range, the supply of etching gas to the chamber 10 proceeds smoothly, and... Figure 1 The components of the etching apparatus (e.g., the various devices or the piping) have low loads.

[0076] Furthermore, from the viewpoint of uniformly etching the surface of the etched component 12, the pressure of the etching gas supplied to the chamber 10 is preferably 1 Pa or more and 100 kPa or less, more preferably 1 kPa or more and 90 kPa or less, even more preferably 2 kPa or more and 80 kPa or less, and particularly preferably 5 kPa or more and 50 kPa or less. If the pressure of the etching gas in the chamber 10 is within the above range, a sufficient etching rate can be obtained for the smooth volatilization of the fluoride in the metal, and the etching selectivity ratio, i.e., the etching rate ratio of the non-etched object, can easily become higher.

[0077] The pressure within chamber 10 before the etching gas is supplied is not particularly limited, as long as it is below or lower than the supply pressure of the etching gas; for example, 10 is preferred. -5 Pa or higher and less than 100 kPa, more preferably 1 Pa or higher and less than 80 kPa.

[0078] The pressure difference between the supply pressure of the etching gas and the pressure inside the chamber 10 before the etching gas is supplied is preferably 1.0 MPa or less, more preferably 0.5 MPa or less, and even more preferably 0.3 MPa or less. If the differential pressure is within the above range, the etching gas can be supplied to the chamber 10 smoothly and easily.

[0079] When supplying etching gas to chamber 10, it is preferable to supply the etching gas while maintaining its temperature at a predetermined value. That is, the supply temperature of the etching gas is preferably 10°C or higher and 250°C or lower.

[0080] The temperature of the etched component 12 during etching is preferably 40°C or higher and 250°C or lower, more preferably 45°C or higher and less than 250°C, and even more preferably 50°C or higher and 200°C or lower. Additionally, depending on the type of non-etched object, the temperature is sometimes preferably 80°C or higher and 150°C or lower. Within this temperature range, the etching of the etched object on the etched component 12 proceeds smoothly, the load on the etching apparatus is small, and the lifespan of the etching apparatus is easily extended.

[0081] The etching processing time (hereinafter sometimes referred to as "etching time") can be arbitrarily set according to the desired degree of etching of the etched object on the etched component 12, but considering the production efficiency of semiconductor device manufacturing processes, it is preferably within 60 minutes, more preferably within 40 minutes, and even more preferably within 30 minutes. Furthermore, the etching processing time refers to the time from the introduction of etching gas into the cavity 10 to the discharge of etching gas from the cavity 10 to complete the etching process.

[0082] The dry etching method of this embodiment can be used as follows: Figure 1 The etching process is carried out using a general plasma-free etching apparatus, similar to the etching apparatus used in semiconductor device manufacturing. There are no particular limitations on the structure of the etching apparatus that can be used.

[0083] For example, the positional relationship between the halogen fluoride gas supply pipe 5 and the etched component 12 is not particularly limited as long as the etching gas can contact the etched component 12. Furthermore, the structure of the temperature control mechanism for the chamber 10 is not particularly limited as long as the temperature of the etched component 12 can be adjusted to any temperature. Therefore, the temperature control mechanism can be directly mounted on the stage 11, or it can be used to heat or cool the chamber 10 from the outside via an external temperature controller.

[0084] in addition, Figure 1 The material of the etching apparatus is not particularly limited, as long as it is resistant to the halogen fluoride used and can be depressurized to a predetermined pressure. For example, in the part in contact with the etching gas, nickel, nickel-based alloys, aluminum, stainless steel, platinum, alumina, ceramics, and fluoropolymers can be used. Specific examples of nickel-based alloys include Inconel (registered trademark), Hastelloy (registered trademark), and Monel (registered trademark). Furthermore, examples of fluoropolymers include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), polyvinylidene fluoride (PVDF), Teflon (registered trademark), VITON (registered trademark), and Kalrez (registered trademark).

[0085] Furthermore, as mentioned above, halogen gases can be present in the etching gas as long as the concentration is less than 5% by volume. When using an etching gas containing halogen gases for etching, for example, one could use... Figure 2 The etching apparatus shown. For Figure 2 The etching apparatus will be explained. However, due to Figure 2 Structure and use of etching equipment Figure 2 The etching method of the etching apparatus and Figure 1 The situation is largely the same for etching devices, so the description of the same parts is omitted, and only the different parts are described.

[0086] Figure 2 The etching apparatus includes an etching gas supply unit that supplies etching gas to the interior of the chamber 10. Figure 2 The etching gas supply section of the etching apparatus includes a halogen fluoride gas supply section 1, an inert gas supply section 2, a halogen elemental gas supply section 17, a halogen fluoride gas supply pipe 5, an inert gas supply pipe 6, and a halogen elemental gas supply pipe 19. The halogen fluoride gas supply section 1 supplies halogen fluoride gas, the inert gas supply section 2 supplies inert gas, and the halogen elemental gas supply section 17 supplies halogen gas. The halogen fluoride gas supply pipe 5 connects the halogen fluoride gas supply section 1 to the chamber 10. The inert gas supply pipe 6 connects to the inert gas supply section 2 at the middle of the halogen fluoride gas supply pipe 5, and the halogen elemental gas supply pipe 19 connects to the halogen elemental gas supply section 17 at the middle of the inert gas supply pipe 6. A halogen elemental gas flow control device 18 for controlling the flow rate of the halogen elemental gas is provided on the halogen elemental gas supply pipe 19.

[0087] When a mixture of halogen fluoride gas and halogen elemental gas is supplied as the etching gas, halogen fluoride gas is supplied from the halogen fluoride gas supply unit 1 to the halogen fluoride gas supply pipe 5, and halogen elemental gas is supplied from the halogen elemental gas supply unit 17 to the halogen fluoride gas supply pipe 5 via the halogen elemental gas supply pipe 19 and the inert gas supply pipe 6. Thus, the halogen fluoride gas and the halogen elemental gas mix in the middle of the halogen fluoride gas supply pipe 5 to form a mixed gas, which is then supplied to the chamber 10 via the halogen fluoride gas supply pipe 5.

[0088] Similarly, when a mixture of halogen fluoride gas, inert gas, and elemental halogen gas is supplied as the etching gas, halogen fluoride gas is supplied from the halogen fluoride gas supply unit 1 to the halogen fluoride gas supply pipe 5, and inert gas is supplied from the inert gas supply unit 2 to the halogen fluoride gas supply pipe 5 via the inert gas supply pipe 6. Furthermore, elemental halogen gas is supplied from the halogen gas supply unit 17 to the halogen fluoride gas supply pipe 5 via the elemental halogen gas supply pipe 19 and the inert gas supply pipe 6. Thus, the halogen fluoride gas, inert gas, and elemental halogen gas mix in the middle of the halogen fluoride gas supply pipe 5 to form a mixed gas, which is then supplied to the chamber 10 via the halogen fluoride gas supply pipe 5.

[0089] Furthermore, the structure of the halogen gas supply unit 17 is not particularly limited; for example, it can be a gas storage cylinder or a gas cylinder. Additionally, the halogen gas flow control device 18 can be, for example, a mass flow controller or a flow meter.

[0090] Example

[0091] The present invention will be described in more detail below with examples, comparative examples, and reference examples. Furthermore, the purity of bromine pentafluoride and iodine heptafluoride used in the following examples, comparative examples, and reference examples was analyzed using a Nicolet iS5 Fourier transform infrared spectrophotometer manufactured by Thermo Fisher Scientific and a U-2900 dual-beam spectrophotometer manufactured by Hitachi High Technology Scientific Co., Ltd., confirming that the purity of both was 99% by mass or higher.

[0092] (Example 1-1)

[0093] Using structure and Figure 1 The etching apparatus is roughly the same as the etching apparatus used to etch the object. (Refer to...) Figure 3 The test piece (etched component) used in Example 1-1 will be described.

[0094] A component (manufactured by KST World Co., Ltd.) is prepared to form a titanium oxide (TiO2) film 22 with a thickness of 517 nm on a square silicon substrate 21 with a side length of 2 inches. A rectangular nickel substrate 23 with dimensions of 1 inch × 2 inches is then bonded to this titanium oxide film 22 using grease (DEMNUM GREASE L-200 manufactured by Daikin Industries, Ltd.) as a test piece. Figure 3 As shown, the nickel substrate 23 is bonded in such a way that it covers approximately half of the titanium oxide film 22.

[0095] The test piece was placed on a stage inside the etching apparatus chamber, and the stage temperature was raised to 150°C. Next, a mixed gas was formed by mixing bromine pentafluoride gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min; this mixed gas was used as the etching gas. Then, the etching gas was supplied to the chamber chamber at a flow rate of 500 mL / min and allowed to circulate for 10 minutes for etching. As a result, the exposed portion of the titanium oxide film 22 not covered by the nickel substrate 23 was etched. The internal pressure of the chamber during the etching gas flow was 10 kPa, and the partial pressure of the bromine pentafluoride gas was 1 kPa. After the etching gas flow was completed, the heating of the stage was stopped, and the interior of the chamber was purged with argon.

[0096] After etching, the chamber was opened, the test piece was removed, and the nickel substrate 23 was taken off the removed test piece. The bonding surface was cleaned with ethanol to remove the grease. Then, using an atomic force microscope VN-8010 manufactured by Keyence Corporation, the size of the step between the covered surface 22a of the titanium oxide film 22 covered by the nickel substrate 23 and thus not etched, and the etched surface 22b of the titanium oxide film 22 not covered by the nickel substrate 23 and thus etched, was measured. The etching rate (nm / min) was calculated by dividing the measured step size (nm) by the etching time (min). The results are shown in Table 1.

[0097] Furthermore, the conditions for determining the step size obtained by atomic force microscopy are as follows.

[0098] Measurement pressure: Atmospheric pressure (101.3 kPa)

[0099] Measurement temperature: 28℃

[0100] Atmosphere measurement: In the atmosphere

[0101] Scanning range: width 80.0 μm, height 20.0 μm, angle 0°

[0102]

[0103] (Examples 1-2)

[0104] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the etching of the test piece was performed in the same manner as in Examples 1-1, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0105] (Examples 1-3)

[0106] The stage temperature was set to 50°C. Otherwise, the test piece was etched in the same manner as in Example 1-1, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0107] (Examples 1-4)

[0108] The halogen fluoride was designated as iodine heptafluoride. A mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. The stage temperature was set to 50°C. Otherwise, the etching of the test piece was performed in the same manner as in Examples 1-1, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0109] (Examples 1-5)

[0110] Using structure and Figure 2 The etching apparatus was largely the same as that used in Examples 1-1. Etching was performed using an etching gas containing halogen elements. Otherwise, the test pieces were etched in the same manner as in Examples 1-1, and the etching rate of titanium oxide was calculated. The results are shown in Table 1. Furthermore, the etching gas used was a mixture of bromine pentafluoride gas (50 mL / min), fluorine gas (F2 gas) (25 mL / min), and argon gas (425 mL / min).

[0111] (Examples 1-6)

[0112] A mixture of bromine pentafluoride gas (50 mL / min), bromine gas (25 mL / min), and argon gas (425 mL / min) was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 1-5, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0113] (Examples 1-7)

[0114] A mixture of iodine heptafluoride gas (50 mL / min), iodine gas (25 mL / min), and argon gas (450 mL / min) was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 1-5, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0115] (Comparative Example 1-1)

[0116] A mixture of fluorine gas (F2 gas) at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 1-1, and the etching rate of titanium oxide was calculated. The results are shown in Table 1.

[0117] (Example 2-1)

[0118] A component (manufactured by KST World Co., Ltd.) was used to replace the titanium oxide film 22 by forming a titanium nitride (TiN) film with a thickness of 500 nm on a silicon substrate 21. Otherwise, test pieces were prepared in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 130°C, and the test piece was etched in the same manner as in Example 1-1, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0119]

[0120] (Example 2-2)

[0121] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 2-1, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0122] (Examples 2-3)

[0123] The pressure inside the chamber was 3 kPa. Otherwise, the test piece was etched in the same manner as in Example 2-1, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0124] (Examples 2-4)

[0125] The pressure inside the chamber was set to 3 kPa. Otherwise, the test piece was etched in the same manner as in Example 2-2, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0126] (Examples 2-5)

[0127] The pressure inside the chamber was set to 50 kPa. Otherwise, the test piece was etched in the same manner as in Example 2-1, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0128] (Examples 2-6)

[0129] The pressure inside the chamber was set to 50 kPa. Otherwise, the test piece was etched in the same manner as in Example 2-2, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0130] (Comparative Example 2-1)

[0131] A mixture of fluorine gas (F2 gas) at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 2-1, and the etching rate of titanium nitride was calculated. The results are shown in Table 2.

[0132] (Example 3-1)

[0133] A component with a 500 nm thick copper (Cu) film formed on a square silicon substrate with sides of 2 inches was prepared as a test piece. Both the test piece with the copper film and the test piece used in Example 2-1 were used as the etched components. These two test pieces were placed side-by-side on a stage within the chamber. The etching of the test pieces was performed in the same manner as in Example 2-1, and the etching rates for titanium nitride (the etched object) and copper (the non-etched object) were calculated. The results are shown in Table 3.

[0134]

[0135] (Example 3-2)

[0136] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the etching of the test piece was performed in the same manner as in Example 3-1, and the etching rates of titanium nitride and copper were calculated. The results are shown in Table 3.

[0137] (Example 3-3)

[0138] A component with a 500 nm thick nickel (Ni) film formed on a square silicon substrate with sides of 2 inches was prepared as a test piece. Both the test piece with this nickel film and the test piece used in Example 2-1 were used as the etched components. These two test pieces were placed side-by-side on a stage within the chamber. Etching of the test pieces was performed in the same manner as in Example 2-1, and the etching rates for titanium nitride (the etched object) and nickel (the non-etched object) were calculated. The results are shown in Table 3.

[0139] (Examples 3-4)

[0140] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the etching of the test piece was performed in the same manner as in Examples 3-3, and the etching rates of titanium nitride and nickel were calculated. The results are shown in Table 3.

[0141] (Examples 3-5)

[0142] A component with a 500 nm thick cobalt (Co) film formed on a square silicon substrate with a side length of 2 inches was prepared as a test piece. Both the test piece with the cobalt film and the test piece used in Example 2-1 were used as the etched components. These two test pieces were placed side-by-side on a stage within the chamber. The etching of the test pieces was performed in the same manner as in Example 2-1, and the etching rates for titanium nitride (the etched object) and cobalt (the non-etched object) were calculated. The results are shown in Table 3.

[0143] (Examples 3-6)

[0144] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the etching of the test pieces was performed in the same manner as in Examples 3-5, and the etching rates of titanium nitride and cobalt were calculated. The results are shown in Table 3.

[0145] (Examples 3-7)

[0146] A photoresist (TSCR, a registered trademark manufactured by Tokyo Ohka Kogyo Co., Ltd.) was coated onto a square silicon substrate with a side length of 2 inches and cured by exposure to form a photoresist film with a thickness of 1000 nm. This film was then prepared as a test piece. Both the test piece with this photoresist film and the test piece used in Example 2-1 were used as etching components. These two test pieces were placed side-by-side on a stage within the chamber. The etching of the test pieces was performed in the same manner as in Example 2-1, and the etching rates for titanium nitride (the object being etched) and the photoresist (the non-etched object) were calculated. The results are shown in Table 3.

[0147] (Examples 3-8)

[0148] The halogenated fluoride was designated as iodine heptafluoride, and a mixed gas consisting of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 3-7, and the etching rates of titanium nitride and photoresist were calculated. The results are shown in Table 3.

[0149] (Comparative Example 3-1)

[0150] A mixed gas of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 3-1, and the etching rates of titanium nitride and copper were calculated. The results are shown in Table 3.

[0151] (Comparative Example 3-2)

[0152] A mixed gas of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 3-3, and the etching rates of titanium nitride and nickel were calculated. The results are shown in Table 3.

[0153] (Comparative Example 3-3)

[0154] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 3-5, and the etching rates of titanium nitride and cobalt were calculated. The results are shown in Table 3.

[0155] (Comparative Examples 3-4)

[0156] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 3-7, and the etching rates of titanium nitride and photoresist were calculated. The results are shown in Table 3.

[0157] (Example 4-1)

[0158] A component (manufactured by KSTWorld Co., Ltd.) was used to replace the titanium oxide film 22 by forming a 500 nm thick titanium oxynitride film on the silicon substrate 21. Otherwise, test pieces were fabricated in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 100°C, and the test piece was etched in the same manner as in Example 1-1 to calculate the etching rate of titanium oxynitride. The results are shown in Table 4.

[0159]

[0160] (Example 4-2)

[0161] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 4-1, and the etching rate of titanium oxynitride was calculated. The results are shown in Table 4.

[0162] (Comparative Example 4-1)

[0163] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 4-1, and the etching rate of titanium oxynitride was calculated. The results are shown in Table 4.

[0164] (Example 5-1)

[0165] A component (manufactured by KSTWorld Co., Ltd.) with a 500 nm thick titanium oxyfluoride film formed on a silicon substrate 21 was used to replace the titanium oxide film 22. Otherwise, test pieces were prepared in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 100°C, and the test piece was etched in the same manner as in Example 1-1 to calculate the etching rate of titanium fluoride. The results are shown in Table 4.

[0166] (Example 5-2)

[0167] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the etching of the test piece was performed in the same manner as in Example 5-1, and the etching rate of titanium fluoride oxide was calculated. The results are shown in Table 4.

[0168] (Comparative Example 5-1)

[0169] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 5-1, and the etching rate of titanium fluoride was calculated. The results are shown in Table 4.

[0170] (Example 6-1)

[0171] A component (manufactured by KSTWorld Co., Ltd.) with a titanium (Ti) film of 500 nm thickness formed on silicon substrate 21 was used instead of titanium oxide film 22. Otherwise, test pieces were prepared in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 80°C, and the test piece was etched in the same manner as in Example 1-1 to calculate the etching rate of titanium. The results are shown in Table 4.

[0172] (Example 6-2)

[0173] The halogenated fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 6-1, and the etching rate of titanium was calculated. The results are shown in Table 4.

[0174] (Comparative Example 6-1)

[0175] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 6-1, and the etching rate of titanium was calculated. The results are shown in Table 4.

[0176] (Example 7-1)

[0177] A component (manufactured by KST World Co., Ltd.) was used to replace the titanium oxide film 22 by forming a 500 nm thick tin oxide (SnO2) film on a silicon substrate 21. Otherwise, test pieces were fabricated in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 160°C, and the test piece was etched in the same manner as in Example 1-1, and the etching rate of tin oxide was calculated. The results are shown below.

[0178] Table 5.

[0179]

[0180] (Example 7-2)

[0181] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 7-1, and the etching rate of tin oxide was calculated. The results are shown in Table 5.

[0182] (Example 7-3)

[0183] The stage temperature was set to 250°C. Otherwise, the test piece was etched in the same manner as in Example 7-1, and the etching rate of tin oxide was calculated. The results are shown in Table 5.

[0184] (Example 7-4)

[0185] The stage temperature was set to 250°C. Otherwise, the test piece was etched in the same manner as in Examples 7-2, and the etching rate of tin oxide was calculated. The results are shown in Table 5.

[0186] (Comparative Example 7-1)

[0187] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test pieces were etched in the same manner as in Examples 7-3, and the etching rate of tin oxide was calculated. The results are shown in Table 4.

[0188] (Example 8-1)

[0189] The component (manufactured by KST World Co., Ltd.) that uses an indium oxide (In2O3) film with a thickness of 500 nm formed on a silicon substrate 21 instead of a titanium oxide film 22 is used. Otherwise, test pieces are prepared in the same manner as in Example 1-1 (see Example 1-1). Figure 3Then, the stage temperature was set to 160°C, and the test piece was etched in the same manner as in Example 1-1 to calculate the etching rate of indium oxide. The results are shown in Table 5.

[0190] (Example 8-2)

[0191] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 8-1, and the etching rate of indium oxide was calculated. The results are shown in Table 5.

[0192] (Comparative Example 8-1)

[0193] A mixture of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 8-1, and the etching rate of indium oxide was calculated. The results are shown in Table 5.

[0194] (Example 9-1)

[0195] A component (manufactured by KSTWorld Corporation) was used to replace the titanium oxide film 22 by forming an indium tin oxide film with a thickness of 500 nm on a silicon substrate 21. Otherwise, test pieces were fabricated in the same manner as in Example 1-1 (see Example 1-1). Figure 3 Then, the stage temperature was set to 160°C, and the test piece was etched in the same manner as in Example 1-1 to calculate the etching rate of indium tin oxide. The results are shown in Table 5.

[0196] (Example 9-2)

[0197] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 9-1, and the etching rate of indium tin oxide was calculated. The results are shown in Table 5.

[0198] (Comparative Example 9-1)

[0199] A mixed gas of fluorine gas at a flow rate of 50 mL / min and argon gas at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Example 9-1, and the etching rate of indium tin oxide was calculated. The results are shown in Table 5.

[0200] (Refer to Example 1-1)

[0201] Prepare test pieces identical to those used in Examples 3-3, which have a nickel film. Then, set the stage temperature to 250°C and, otherwise, etch the test pieces in the same manner as in Examples 1-1, calculating the nickel etching rate. The results are shown in Table 6.

[0202]

[0203] (Refer to Example 1-2)

[0204] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Reference Example 1-1, and the etching rate of nickel was calculated. The results are shown in Table 6.

[0205] (Refer to Example 2-1)

[0206] Prepare test pieces identical to those used in Examples 3-5, each with a cobalt film. Then, set the stage temperature to 250°C and, otherwise, etch the test pieces in the same manner as in Examples 1-1, calculating the cobalt etching rate. The results are shown in Table 6.

[0207] (Refer to Example 2-2)

[0208] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Reference Example 2-1, and the etching rate of cobalt was calculated. The results are shown in Table 6.

[0209] (Refer to Example 3-1)

[0210] Prepare a test piece identical to the one with a copper film used in Example 3-1. Then, set the stage temperature to 120°C and, otherwise, etch the test piece in the same manner as in Example 1-1, and calculate the copper etching rate. The results are shown in Table 6.

[0211] (Refer to Example 3-2)

[0212] The halogen fluoride was designated as iodine heptafluoride, and a mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Reference Example 3-1, and the etching rate of copper was calculated. The results are shown in Table 6.

[0213] (Refer to Example 4-1)

[0214] Prepare test pieces identical to those used in Examples 3-7, which have a photoresist film. Then, set the stage temperature to 120°C and, otherwise, etch the test pieces in the same manner as in Examples 1-1, calculating the photoresist etching rate. The results are shown in Table 6.

[0215] (Refer to Example 4-2)

[0216] The halogenated fluoride was designated as iodine heptafluoride. A mixture of iodine heptafluoride gas at a flow rate of 50 mL / min and argon at a flow rate of 450 mL / min was used as the etching gas. The stage temperature was set to 100 °C. Otherwise, the test piece was etched in the same manner as in Reference Example 4-1, and the etching rate of the photoresist was calculated. The results are shown in Table 6.

[0217] (Refer to Example 4-3)

[0218] A mixture of bromine pentafluoride gas (50 mL / min), fluorine gas (25 mL / min), and argon gas (425 mL / min) was used as the etching gas. Otherwise, the test piece was etched in the same manner as in Reference Example 4-1, and the etching rate of the photoresist was calculated. The results are shown in Table 6.

[0219] As shown in Examples 1-1 to 1-4, titanium oxide etching can be performed by using etching gases containing bromine pentafluoride or iodine heptafluoride. However, in Examples 1-5 to 1-7, which used etching gases containing 5% by volume of halogen gas, the etching rate of titanium oxide was slightly lower compared to Examples 1-1 and 1-2. On the other hand, in Comparative Example 1-1, which used a mixture of fluorine and argon as the etching gas, titanium oxide etching was not performed. This is presumably because the halogen gas reacts with the titanium oxide to form a passivation film.

[0220] As shown in Examples 2-1 to 2-6, the etching of titanium nitride was advanced by using an etching gas containing bromine pentafluoride or iodine heptafluoride. On the other hand, in Comparative Example 2-1, which used a mixture of fluorine and argon as the etching gas, titanium nitride etching was not performed.

[0221] As shown in Examples 3-1 to 3-8, when titanium nitride (the object to be etched) and copper, nickel, cobalt, or photoresist (the objects not to be etched) are simultaneously etched using an etching gas containing bromine pentafluoride or iodine heptafluoride, only titanium nitride (the object to be etched) is selectively etched, and the objects not to be etched are hardly etched. On the other hand, in Comparative Examples 3-1 to 3-4, which use a mixture of fluorine and argon as the etching gas, not only are the objects not to be etched almost not etched, but even the objects to be etched are hardly etched.

[0222] As shown in Examples 4-1, 4-2, 5-1, 5-2, 6-1, 6-2, 7-1, 7-2, 7-3, 7-4, 8-1, 8-2, 9-1, and 9-2, etching of titanium oxynitride, titanium oxyfluoride, titanium, tin oxide, indium oxide, and indium tin oxide can be performed by using etching gases containing bromine pentafluoride or iodine heptafluoride. On the other hand, in Comparative Examples 4-1 to 9-1, which used a mixture of fluorine and argon as the etching gas, almost no etching was performed on any of the objects being etched.

[0223] As shown in Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, and 4-2, even when using etching gases containing bromine pentafluoride or iodine heptafluoride, nickel, cobalt, copper, and photoresist are hardly etched. Therefore, if the etching of the above embodiments is performed, nickel, cobalt, copper, and photoresist, which are not the objects to be etched, will not be etched, and titanium oxide, titanium nitride, titanium oxynitride, titanium fluoride, titanium, tin oxide, indium oxide, and indium tin oxide can be selectively etched.

[0224] On the other hand, as shown in Reference Example 4-3, when a mixed gas containing fluorine gas is used as the etching gas, the etching of the photoresist proceeds only slightly. This indicates that if the etching gas contains halogen elemental gas, it will affect the etching selectivity of the object to be etched and the non-object to be etched.

[0225] Explanation of reference numerals in the attached figures

[0226] 1…Halogen fluoride gas supply department

[0227] 2…Inert gas supply section

[0228] 3…Halogen fluoride gas flow control device

[0229] 4…Inert gas flow control device

[0230] 5…Pipes for supplying halogenated fluoride gases

[0231] 6… Piping for inert gas supply

[0232] 7, 16… pressure gauges

[0233] 8…Inert gas pressure control device

[0234] 10…chamber

[0235] 11…Platform

[0236] 12…etched components

[0237] 13…Exhaust piping

[0238] 14…Thermometer

[0239] 15…vacuum pump

[0240] 17…Halogen Gas Supply Department

[0241] 18…Halogen elemental gas flow control device

[0242] 19…Pipes for supplying halogen elemental gases

[0243] 21…Silicon substrate

[0244] 22…Titanium oxide film

[0245] 23…Nickel substrate

Claims

1. A dry etching method comprising a dry etching step, wherein the dry etching step involves contacting an etching gas containing a halogenated fluoride with a component having an object to be etched, thereby etching the object without using plasma, wherein the halogenated fluoride is a compound of bromine or iodine and fluorine, and the object to be etched is an object etched by the etching gas, the object to be etched containing at least one metal selected from titanium, indium, and tin. The etching gas is either a gas composed solely of the halogen fluoride or a mixture of the halogen fluoride and an inert gas. The object to be etched is at least one selected from the elemental form of the metal, the oxide of the metal, the nitride of the metal, the oxynitride of the metal, and the fluorine oxide of the metal.

2. The dry etching method according to claim 1, wherein the halogen fluoride is selected from at least one of bromine monofluoride, bromine trifluoride, bromine pentafluoride, iodine pentafluoride, and iodine heptafluoride.

3. The dry etching method according to claim 1 or 2, wherein the dry etching process is performed at a temperature of 40°C or higher and 250°C or lower.

4. The dry etching method according to claim 1 or 2, wherein the dry etching process is performed at a temperature of 80°C or higher and 150°C or lower.

5. The dry etching method according to claim 1 or 2, wherein the dry etching process is performed under pressure conditions of 1 Pa or higher and 100 kPa or lower.

6. The dry etching method according to claim 1 or 2, wherein the etched component has a non-etchable object and the etchable object, and the non-etchable object is not an object to be etched by the etching gas. The non-etched object has at least one selected from copper, nickel, cobalt, and photoresist. The etchable object is selectively etched compared to the non-etched object.

7. A method for manufacturing a semiconductor device, comprising manufacturing the semiconductor device using the dry etching method according to any one of claims 1 to 6. The component to be etched is a semiconductor substrate having the object to be etched. The manufacturing method includes a processing step in which at least a portion of the object to be etched is removed from the semiconductor substrate by etching.

8. A cleaning method, comprising cleaning the inner surface of a chamber of a semiconductor device manufacturing apparatus using the dry etching method according to any one of claims 1 to 6. The component to be etched is the chamber, and the inner surface of the chamber has an adhering substance that is attached during the operation of the semiconductor device manufacturing apparatus; this adhering substance is the object to be etched. The cleaning method includes a cleaning step in which the deposits are removed from the inner surface of the chamber by etching.

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