Manufacturing method for a member having a recessed structure

Abstract

To provide a method for manufacturing a component that allows for the formation of recessed structures more quickly. [Solution] A method for manufacturing a member having a recessed structure, comprising: a first step of preparing a workpiece containing silicon; and a second step of forming a catalyst material on a part of the surface of the workpiece. The method comprises a third step of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250°C or higher, thereby forming a recessed structure in the portion of the workpiece where the catalyst material is formed.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a member having a concave structure.

Background Art

[0002] There is a need for microfabrication techniques that can form a fine concave structure on the surface of a sample in various fields. Various methods have been proposed and put into practical use as microfabrication techniques.

[0003] One of the microfabrication techniques is the dry etching method. In this method, the surface of a sample is etched using reactants such as reactive gases, ions, and / or radicals.

[0004] Patent Document 1 discloses a method for forming a thermoelectric element, which includes having a pattern of a metal material adjacent to a substrate containing a semiconductor material, the metal material being configured to catalyze the oxidation of the substrate, and exposing the metal material to a vapor-phase oxidizing agent and a vapor-phase chemical etching agent to etch the substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the method disclosed in Patent Document 1 has a slow processing speed, and there is a need for an etching method that can form a concave structure more rapidly.

[0007] The present disclosure has been made in view of the above circumstances, and provides a method for manufacturing a member capable of forming a concave structure more rapidly.

Means for Solving the Problems

[0008] In this invention, A method for manufacturing a member having a recessed structure, The first step is to prepare a material to be treated that contains silicon, A second step involves forming a catalyst material on a part of the surface of the object to be treated, A manufacturing method is provided, comprising a third step of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250°C or higher, thereby forming a recessed structure in the portion of the workpiece where the catalyst material is formed. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a method for manufacturing a member that can form a recessed structure more quickly. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram of a workpiece on which a catalyst material is formed on its surface in one embodiment of the present invention. [Figure 2] This is a diagram of a workpiece in which an oxide layer is formed in a coated region according to one embodiment of the present invention. [Figure 3] This is a diagram of a workpiece that has been etched according to one embodiment of the present invention. [Figure 4] This is a flowchart showing the manufacturing method of a component according to one embodiment of the present invention. [Figure 5] This diagram schematically shows the state in which the object to be processed is housed in the processing chamber in one embodiment of the present invention. [Figure 6] This is a diagram of a workpiece having a recessed structure in one embodiment of the present invention. [Figure 7] This is an SEM image of the surface of a workpiece taken from above in one embodiment of the present invention. [Figure 8] This is an SEM image of a cross-section of a workpiece in one embodiment of the present invention. [Figure 9] This is an SEM image taken from above of the surface of a workpiece that was not treated with an oxidizing gas during etching. [Figure 10] This is a SEM image of a cross-section of a workpiece on which no oxidizing gas was used during etching.

Embodiments for Carrying out the Invention

[0011] An embodiment of the present invention will be described below. In each embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted or simplified. For clarity of explanation, the following description and drawings are appropriately simplified, and the scales of each member may be greatly different. The inventors of the present application have intensively studied and developed a method for more rapidly microfabricating a workpiece containing silicon. Then, the inventors of the present application have found that when the workpiece is processed under predetermined conditions with a catalyst material formed on the surface of the workpiece, the etching rate at the catalyst interface is significantly improved, leading to the present invention.

[0012] Therefore, in one embodiment of the present invention, A method for manufacturing a member having a concave structure, comprising: a first step of preparing a workpiece containing silicon; a second step of forming a catalyst material on a part of the surface of the workpiece; a third step of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250 °C or higher to form a concave structure in the portion of the workpiece where the catalyst material is formed.

[0013] In the present application, the "workpiece" represents a member that becomes a member having a concave structure after etching, and contains silicon at least on the processed surface. Examples of the workpiece include a silicon-containing substrate, a base material having a silicon-containing layer, and the like.

[0014] Also, in the present application, the "concave structure" means a form having a level lower than the level of the processed surface of the workpiece. Therefore, the "concave structure" includes grooves, holes, and the like.

[0015] The method according to an embodiment of the present invention has a process of exposing a workpiece having a catalyst material formed on its surface to a mixed gas of a fluorine-containing gas and an oxidizing gas at a processing temperature of 250 °C or higher (hereinafter, this process is referred to as "the etching process of the present invention"). By performing such an etching process of the present invention, the region where the catalyst material is formed (hereinafter referred to as "the coated region") on the surface of the workpiece can be selectively etched.

[0016] Hereinafter, referring to the drawings, the reason why such etching is possible, which is considered at the present time, will be described.

[0017] (Mechanism of the etching process) First, the mechanism of the etching process of the present invention will be described. The etching process of the present invention (A) Oxide formation by reaction of the workpiece and the oxidizing gas (B) Fluoride generation by reaction of the oxide and the fluorine-containing gas is executed by two processes.

[0018] <Process (A): Oxide formation> FIG. 1 is a diagram showing a state where a catalyst material is formed on the surface of the workpiece. Here, the workpiece 1 is, for example, a silicon substrate. In Process (A), by exposing the workpiece 1 having the catalyst material 3 formed in a pattern on its surface to an oxidizing gas, Si on the surface of the workpiece 1 is oxidized to tetravalent silicon (Si(IV), for example, SiO2).

[0019] In the etching process of the present invention, the catalyst material 3 has at least one selected from the group consisting of metal halides and transition metal oxides. Such a catalyst material is considered to play a role of lowering the activation energy of oxide formation on the surface of the workpiece.

[0020] Therefore, when the workpiece 1 in the state shown in Figure 1 is exposed to an oxidizing gas, the Si in the coated region 8 is selectively oxidized to SiO2, or at least oxidized faster than other regions, as shown in Figure 2. In other words, SiO2 (for example, an oxide film 4) is formed at the interface between the workpiece 1 and the catalyst material 3.

[0021] <Process (B): Fluoride Formation> Next, the fluorine-containing gas reacts with the SiO2 formed on the surface of the coated region 8 in process (A), generating fluoride in the coated region 8 according to the following reaction equation (1). SiO2+4HF → SiF4↑+ 2H2O↑ (1) The SiF4 and H2O produced in the reaction are both gases at the processing temperature and are rapidly released from the system. That is, the coated region 8 where SiO2 is generated in process (A) is selectively etched in process (B). As a result, as shown in Figure 3, the etching reaction proceeds continuously in the lower part of the coated region 8, and the recessed structure 5 is formed. The size of the HF molecules is sufficiently smaller than the size of the voids in the catalyst material 3. Therefore, when the object to be treated 1 is exposed to HF gas, the HF gas can pass through the catalyst material 3 and reach the interface between the catalyst material 3 and the object to be treated 1.

[0022] Furthermore, it is known that fluorine (F) radicals released from fluorine-containing gases such as hydrogen fluoride gas are more reactive with materials to be treated, including silicon, than hydrogen fluoride gas itself. However, under normal circumstances, hydrogen fluoride gas has a high bond energy, making it difficult for F to be released into radicals.

[0023] On the other hand, catalyst materials selected from the group consisting of metal halides and transition metal oxides are thought to play a role in lowering the activation energy of fluoride formation on the surface of the object being treated.

[0024] Therefore, it is thought that when a fluorine-containing gas comes into contact with a catalyst material, the dissociation of fluorine radicals from the fluorine-containing gas is promoted.

[0025] It is believed that the promotion of the dissociation of such active fluorine radicals leads to a significantly higher etching rate compared to conventional methods in environments where the catalyst material and fluorine-containing gas coexist.

[0026] In one embodiment of the present invention, a recessed structure with a high aspect ratio can be formed on the surface of a workpiece relatively easily. Therefore, one embodiment of the present invention can also be applied to microfabrication techniques such as deep grooves and / or holes used in the semiconductor field.

[0027] Furthermore, laser processing technology is a conventionally known high-speed recess structure formation technique. In laser processing technology, high-precision grooves can be processed by irradiating the surface of the workpiece with laser light and scanning it.

[0028] However, laser processing technology is not suitable for creating a large number of grooves at once on a large workpiece.

[0029] In contrast, the manufacturing method according to one embodiment of the present invention can also be applied to large-area patterning techniques, such as conventional lithography. Therefore, the manufacturing method according to one embodiment of the present invention can also be applied to workpieces having a large surface area.

[0030] (Method for manufacturing a component according to one embodiment of the present invention) Next, one embodiment of the present invention will be described in more detail with reference to the drawings. Figure 4 is a flowchart of the method for manufacturing a component according to one embodiment of the present invention.

[0031] As shown in Figure 4, the method for manufacturing a component according to one embodiment of the present invention is The first step (S110) is to prepare a workpiece containing silicon, The second step (S120) is to form a catalyst material on a part of the surface of the object to be treated, The method comprises the step (S130) of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250°C or higher to form a recessed structure in the portion of the workpiece where the catalyst material is formed.

[0032] The following explains each step.

[0033] (Step S110) First, the object to be processed (object 1) is prepared.

[0034] The object to be processed may be composed of a single component or multiple components.

[0035] When the object to be treated is composed of a single component, the object to be treated 1 may be a silicon substrate or a glass substrate (e.g., quartz glass). However, from the viewpoint of reactivity with a mixed gas of a fluorine-containing gas and an oxidizing gas, the object to be treated 1 is preferably a silicon substrate.

[0036] On the other hand, when the object to be treated is composed of a laminate of multiple members, the object to be treated includes a silicon-containing layer on its outermost surface.

[0037] Furthermore, if the object to be treated is composed of a laminate of multiple components, the object to be treated may have one or more films placed on a substrate. The outermost film of these films contains silicon, and from the viewpoint of reactivity with a mixed gas of fluorine-containing gas and oxidizing gas, a silicon coating is preferred for the outermost film.

[0038] In the following description, each step will be explained using the example where the object to be processed 1 is a silicon substrate.

[0039] (Step S120) Next, a catalyst material 3 is formed on a portion of the first surface 11 of the object to be treated 1.

[0040] The catalyst material 3 comprises at least one selected from the group consisting of metal halides and transition metal oxides.

[0041] Among these, examples of metal halides include fluorides such as manganese fluoride, iron fluoride, sodium fluoride, and calcium fluoride. Manganese fluoride is particularly preferred among the metal halides because it exhibits significantly higher activity in response to the treatment in step S130.

[0042] Examples of transition metal oxides include manganese oxide, iron oxide, zinc oxide, copper oxide, nickel oxide, and chromium oxide. Manganese oxide is particularly preferred among the transition metal oxides because it exhibits significantly higher activity in the treatment in step S130.

[0043] The method for forming the catalyst material 3 is not particularly limited.

[0044] The catalyst material 3 may be formed on the first surface 11 by, for example, a coating method, a printing method, or a photolithography method.

[0045] The thickness of the catalyst material 3 can be adjusted within the range of 0.01 μm to 10 μm, preferably within the range of 0.1 μm to 4 μm. By setting the thickness of the catalyst material 3 to 4 μm or less, the decrease in the etching rate of the workpiece 1 in the subsequent step S130 can be suppressed. Furthermore, by setting the thickness of the catalyst material 3 to 0.1 μm or more, the etching rate of the workpiece 1 can be increased.

[0046] (Step S130) Next, the object to be treated 1 is exposed to a mixed gas of a fluorine-containing gas and an oxidizing gas to form a recessed structure on the object to be treated 1.

[0047] When exposing the object to be treated 1 to the mixed gas, the object to be treated 1 may be housed in a processing chamber.

[0048] Figure 5 schematically shows the state in which the object to be processed 1 is supported by the holder 61 and housed in the processing chamber 6.

[0049] The etching process of the workpiece 1 is carried out by supplying a mixed gas of a fluorine-containing gas and an oxidizing gas to the workpiece 1. For example, in the example shown in Figure 5, a mixed gas of a fluorine-containing gas and an oxidizing gas may be supplied into the processing chamber 6.

[0050] Fluorine-containing gases include, for example, hydrogen fluoride gas and / or fluorine gas.

[0051] Oxidizing gases include, for example, air, oxygen, hydrogen peroxide, ozone, carbon monoxide, carbon dioxide, water vapor, carbonyl fluoride, or nitrogen dioxide. Oxygen is particularly preferred as the oxidizing gas from the viewpoint of high reactivity and cost.

[0052] The mixed gas is obtained by mixing the fluorine-containing gas and the oxidizing gas described above. The mixed gas may also contain a carrier gas other than the fluorine-containing gas and the oxidizing gas. The carrier gas may be an inert gas, such as nitrogen and / or argon.

[0053] By supplying a mixed gas into the processing chamber 6, the Si in the coated area 8 is oxidized, and the workpiece 1 is etched.

[0054] The etching conditions vary depending on the shape of the recessed structure 5 that is formed, but the processing time is, for example, in the range of 5 seconds to 30 minutes.

[0055] The processing gas used in the etching process is a mixed gas containing a fluorine-containing gas and an oxidizing gas, and may also contain a carrier gas such as argon or nitrogen. The concentration of the fluorine-containing gas is, for example, in the range of 0.1 vol% to 50 vol% when the total mixed gas is considered to be 100 vol%. The concentration of the oxidizing gas is, for example, in the range of 1 vol% to 99 vol% when the total mixed gas is considered to be 100 vol%. Furthermore, the pressure of the processing gas during the etching process (i.e., the pressure inside the chamber) is not particularly limited and may be atmospheric pressure or a reduced pressure atmosphere.

[0056] Furthermore, in this invention, an acidic gas such as hydrogen chloride gas or hydrogen bromide gas may be added as an additive gas to the fluorine-containing gas (etching gas). The acidic gas has the effect of enhancing the catalytic activity during etching by reacting with the catalyst material. In addition, an oxidizing gas such as oxygen gas may be added as an additive gas to the etching gas. For example, when etching a silicon substrate, the silicon substrate may be oxidized using an oxidizing gas before etching using the above method.

[0057] Furthermore, a gas that forms a deposited film may be used together with a fluorine-containing gas (etching gas). By including a gas that forms a deposited film in the etching gas, the etching rate on the side walls of the recessed structure can be reduced during etching, thereby improving the rectangularity of the recessed structure. Here, the gas that forms a deposited film refers to a compound that is a gas in the etching environment and deposits on the substrate to form a film. Examples of gases that form a deposited film include fluorocarbon gases, hydrofluorocarbon gases, hydrocarbon gases, halogen-containing gases, aromatic ring-containing gases, and ethers. Alternatively, the etching gas and the gas that forms a deposited film on the side walls of the recessed structure of the substrate may be supplied alternately into the chamber. For example, by performing plasma treatment while introducing a fluorocarbon gas, hydrofluorocarbon gas, etc., a deposited film can be formed on the side walls of the recessed structure of the substrate.

[0058] Furthermore, the etching process is preferably carried out while the workpiece 1 or the processing chamber 6 is heated. The processing temperature is preferably 250°C or higher for the workpiece 1, more preferably 600°C or higher, and particularly preferably 750°C or higher. On the other hand, the upper limit of the processing temperature is preferably 1000°C or lower, more preferably 950°C or lower, and even more preferably 900°C or lower, from the viewpoint of the heat resistance of the workpiece 1.

[0059] In the aforementioned Patent Document 1, a metallic material such as silver is placed on a silicon substrate and used as a catalyst. Etching of a silicon substrate proceeds by first oxidizing Si and then reacting the Si oxide with a fluorine-containing gas, as described above (see equation (1) above). When a metallic material is used as a catalyst, electrons move from the metallic material to the oxidizing gas, and then electrons move from Si to the metallic material, causing oxidation of Si near the interface with the metallic material. Generally, the electrical resistance of a silicon substrate decreases as the temperature increases. Therefore, in a high-temperature environment, electrons in the silicon substrate are rapidly supplied to the silicon oxidized near the interface, and the oxidized silicon is reduced. As a result, the reaction between Si oxide and fluorine gas is inhibited, so the increase in etching rate due to high temperature is suppressed, and the etching rate is about 0.6 μm / min. In embodiments of the present invention, one or more catalyst materials selected from the group consisting of metal halides and transition metal oxides are used. As a result, Si is rapidly oxidized to SiO2, which is expected to suppress electron supply to the silicon oxide and inhibit reaction even in high-temperature environments. Therefore, the benefits of increased etching rate due to high temperature can be strongly realized, and a high etching rate can be obtained.

[0060] Manganese oxide is preferred as a transition metal oxide used as a catalyst material. In manganese oxide, Mn is stable in the tetravalent state (MnO2) at room temperature, but exists in the trivalent state (Mn2O3) or approximately 2.67 valent state (Mn3O4) at high temperatures. Therefore, it has a high effect of removing electrons from Si near the catalyst material interface, making it possible to rapidly oxidize Si to SiO2. In addition, manganese oxide has a very high etching effect on the generated SiO2, and the etching rate of SiO2 when manganese oxide is used as a catalyst material can reach up to about 100 μm / min. For this reason, compared to when a metal material is used as a catalyst, etching a silicon substrate with manganese oxide as a catalyst allows for the formation of recessed structures on the silicon substrate more rapidly.

[0061] Furthermore, manganese fluoride is preferred as the metal halide used as the catalyst material. At high temperatures, Mn in manganese fluoride exists in a divalent state (MnF2). Therefore, similar to Mn in manganese oxide, it has a high effect of removing electrons from Si near the catalyst material interface, making it possible to rapidly oxidize Si to SiO2. For this reason, etching a silicon substrate using manganese fluoride as a catalyst also makes it possible to form recessed structures on the silicon substrate more rapidly.

[0062] In the first manufacturing method, the processing speed of the workpiece 1 can be adjusted by controlling the concentration of the supplied fluorine-containing gas and oxidizing gas, the processing temperature, and the processing time. In particular, by raising the processing temperature to 250°C or higher, the recessed structures 5 formed by the etching process are formed at a rate of 10 μm / min or more in the downward direction of the catalyst material 3.

[0063] After step S120, a step may be performed to remove the catalyst material 3 remaining at the bottom of the recessed structure 5. This results in a workpiece 1 having a recessed structure 5 as shown in Figure 6. The removal of the catalyst material 3 is carried out, for example, by washing the workpiece 1 with an acid solution, an alkaline solution, an organic solvent, a corrosive gas, or plasma.

[0064] After the removal of the catalyst material 3, a recessed structure 5 is formed on the surface of the workpiece 1, with a shape that follows the pattern of the catalyst material 3. Specifically, the recessed structure 5 is formed below the catalyst material 3, extending from the first surface 11 of the workpiece 1 toward the opposite surface (second surface) 12.

[0065] The aspect ratio of the recessed structure 5 can be adjusted to a desired range by controlling the processing conditions. For example, the aspect ratio of the recessed structure 5 can be adjusted within the range of 0.1 to 100. The aspect ratio of the recessed structure 5 can be, for example, 1 or more, 10 or more, or 20 or more.

[0066] Here, the aspect ratio is calculated as the depth of the recessed structure 5 relative to the "minimum dimension" of the surface opening. The "minimum dimension" corresponds to the minimum width of the groove if the recessed structure 5 is a groove, and to the diameter of the circle if the recessed structure 5 is a circular hole.

[0067] Furthermore, the shape and arrangement of the recessed structure 5 are not particularly limited. For example, the recessed structure 5 may be a bottomed structure or a through structure. The bottomed structure may be, for example, a bottomed hole and / or a bottomed groove. The through structure may be a through hole or a through groove. Similarly, the pattern of the recessed structure 5 may take any form.

[0068] The above describes a method for manufacturing a workpiece having a recessed structure according to one embodiment of the present invention, using the first manufacturing method as an example. However, the above description is merely an example, and the manufacturing method according to one embodiment of the present invention may include other steps.

[0069] Other changes are also possible. [Examples]

[0070] The following describes embodiments of the present invention.

[0071] In the following description, Example 1 is an example, and Example 2 is a comparative example.

[0072] (Example 1) A recessed structure was formed on one surface of the object to be treated using the following method.

[0073] First, a silicon substrate was prepared as the processing body. Next, MnO2 reagent powder was sprinkled onto the silicon substrate as a catalyst material.

[0074] Next, the substrate coated with the catalyst material was cut into pieces approximately 20 mm x 20 mm in size, and the cut samples were placed in the processing chamber. Subsequently, gas etching of the samples was performed in the processing chamber. A mixed gas of hydrogen fluoride and oxygen (HF: 20 vol%, O2: 80 vol%) was used as the processing gas. The processing temperature was set to 800°C. The processing time was 1 minute.

[0075] The processed material obtained after etching is referred to as "Sample 1".

[0076] (Example 2) Similar to Example 1, a sample coated with catalyst material was placed in a processing chamber, and gas etching of the sample was performed. A mixed gas of hydrogen fluoride and nitrogen (HF: 20 vol%, N2: 80 vol%) was used as the processing gas. The processing temperature was 800°C. The processing time was 1 minute.

[0077] The processed material obtained after etching is referred to as "Sample 2".

[0078] Table 1 below shows the conditions for creating Sample 1 and Sample 2.

[0079] [Table 1]

[0080] (evaluation) For each sample, the top surface and cross-section of the sample were observed using a scanning electron microscope (SEM), and the etching depth was measured.

[0081] Figures 7-8 show SEM images of the top and cross-section of sample 1. Figures 9-10 show SEM images of the top and cross-section of sample 2.

[0082] Figures 7-8 confirm that in Sample 1, a recessed structure corresponding to the shape of the reagent powder was formed on the surface.

[0083] Figures 9-10 confirm that no recessed structures were formed on the surface of sample 2.

[0084] The results obtained for each sample are shown in Table 2 below.

[0085] [Table 2]

[0086] The results shown in Table 2 indicate that a high etching rate of 10 μm / min or more was achieved in Sample 1.

[0087] (One aspect of the present invention) The present invention may have the following embodiments.

[0088] (Aspect 1) A method for manufacturing a member having a recessed structure, The first step is to prepare a material to be treated that contains silicon, A second step involves forming a catalyst material on a part of the surface of the object to be treated, The process includes a third step of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250°C or higher, thereby forming a recessed structure in the portion of the workpiece where the catalyst material is formed. Manufacturing method.

[0089] (Aspect 2) The manufacturing method according to embodiment 1, wherein the catalyst material promotes fluoride formation at the interface with the object to be treated.

[0090] (Aspect 3) The manufacturing method according to embodiment 1 or 2, wherein the catalyst material comprises one or more selected from the group consisting of metal halides and transition metal oxides.

[0091] (Aspect 4) The manufacturing method according to any one of embodiments 1 to 3, wherein the catalyst material comprises one or more selected from the group consisting of manganese fluoride, metallic manganese, and manganese oxide.

[0092] (Aspect 5) The manufacturing method according to any one of embodiments 1 to 4, wherein the fluorine-containing gas is one or more selected from hydrogen fluoride gas and fluorine gas.

[0093] (Aspect 6) The manufacturing method according to any one of embodiments 1 to 5, wherein the oxidizing gas includes oxygen gas.

[0094] (Aspect 7) The manufacturing method according to any one of embodiments 1 to 6, wherein the object to be processed is composed of a single component.

[0095] (Pattern 8) The manufacturing method according to embodiment 7, wherein the object to be processed is a silicon substrate.

[0096] (Aspect 9) The manufacturing method according to any one of embodiments 1 to 8, wherein in the third step, silicon oxide is formed at the interface between the workpiece and the catalyst material.

[0097] (Aspect 10) The manufacturing method according to embodiments 1 to 9, wherein the object to be processed has one or more films placed on a substrate.

[0098] (Aspect 11) The manufacturing method according to embodiment 10, wherein the outermost film of the aforementioned films is a silicon coating.

[0099] (Aspect 12) The manufacturing method according to any one of embodiments 1 to 11, wherein in the third step, the ambient temperature is 600°C or higher.

[0100] (Aspect 13) The manufacturing method according to any one of embodiments 1 to 12, wherein the recessed structure includes a bottomed structure and / or a through-structure.

[0101] (Aspect 14) The manufacturing method according to embodiment 13, wherein the recess structure is at least one of a bottomed hole, a through hole, a bottomed groove, and a through groove.

[0102] (Aspect 15) The manufacturing method according to any one of embodiments 1 to 14, wherein in the third step, the processing speed in the depth direction of the recessed structure is 10 μm / min or more. [Explanation of symbols]

[0103] 1. Object to be processed 11 First surface 12 Second surface 3. Catalyst materials 4. Oxide film 5. Recessed structure 6 Processing Chamber 61 Holder 8 Covered area

Claims

1. A method for manufacturing a member having a recessed structure, The first step is to prepare a material to be treated that contains silicon, A second step involves forming a catalyst material on a part of the surface of the object to be treated, The process includes a third step of exposing the workpiece to a mixed gas of a fluorine-containing gas and an oxidizing gas in an environment of 250°C or higher, thereby forming a recessed structure in the portion of the workpiece where the catalyst material is formed. Manufacturing method.

2. The manufacturing method according to claim 1, wherein the catalyst material promotes the formation of fluoride at the interface with the object to be treated.

3. The manufacturing method according to claim 1, wherein the catalyst material comprises one or more selected from the group consisting of metal halides and transition metal oxides.

4. The manufacturing method according to claim 3, wherein the catalyst material comprises one or more selected from the group consisting of manganese fluoride and manganese oxide.

5. The manufacturing method according to claim 1, wherein the fluorine-containing gas is one or more selected from hydrogen fluoride gas and fluorine gas.

6. The manufacturing method according to claim 1, wherein the oxidizing gas includes oxygen gas.

7. The manufacturing method according to claim 1, wherein the object to be processed is composed of a single component.

8. The manufacturing method according to claim 7, wherein the object to be processed is a silicon substrate.

9. The manufacturing method according to claim 1, wherein in the third step, silicon oxide is formed at the interface between the workpiece and the catalyst material.

10. The manufacturing method according to claim 1, wherein the object to be treated has one or more films placed on a substrate.

11. The manufacturing method according to claim 10, wherein the outermost film of the aforementioned films is a silicone coating.

12. The manufacturing method according to claim 1, wherein in the third step, the ambient temperature is 600°C or higher.

13. The manufacturing method according to claim 1, wherein the recessed structure includes a bottomed structure and / or a through-structure.

14. The manufacturing method according to claim 1, wherein the recess structure is at least one of a bottomed hole, a through hole, a bottomed groove, and a through groove.

15. The manufacturing method according to claim 1, wherein in the third step, the processing speed in the depth direction of the recessed structure is 10 μm / min or more.

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