Method for manufacturing a member having a recessed structure, and member having a recessed structure

Abstract

The present invention provides a method for relatively easily manufacturing a component that exhibits high adhesion to other components, and a component having such a recessed structure. [Solution] A manufacturing method according to one embodiment of the present invention is a method for manufacturing a member having a recessed structure, comprising: a first step of preparing a workpiece containing an element whose fluoride boiling point is 550°C or lower; 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 fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece on which the catalyst material is formed; and a fourth step of exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature to form a second recessed structure having a wider recess than the first recessed structure.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a member having a recessed structure, and to a member having a recessed structure. [Background technology]

[0002] Microfabrication technology, which can form fine recessed structures on the surface of a sample, is in demand in various fields. To date, various methods have been proposed and put into practical use as microfabrication technologies.

[0003] One microfabrication technique is dry etching, in which the surface of a sample is etched using reactive gases, ions, and / or radicals.

[0004] For example, in reactive ion etching (RIE) methods, such as inductive coupled plasma-RIE (ICP-RIE), etching is performed by plasmaizing an etching gas and colliding it with the sample. Such RIE methods have been reported to enable extremely fine processing of samples (for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] xiao Li,King Yuk Chan and Rodica Ramer,“Fabrication of Through via Holes in Ultra-Thin Fused SilicaWafers for Microwave and Millimeter-Wave Applications”,micromachines,2018,9,138 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, a problem exists in that components microfabricated using the RIE method have difficulty in achieving good adhesion with other components.

[0007] This invention has been made in view of the above background, and aims to provide a method for relatively easily manufacturing a member that has high adhesion to other members. Furthermore, this invention aims to provide a member having such a recessed structure. [Means for solving the problem]

[0008] The present invention provides a method for manufacturing a member having a recessed structure, The first step is to prepare a material to be treated that contains elements whose fluoride boiling point is 550°C or lower, A second step involves forming a catalyst material on a part of the surface of the object to be treated, A third step involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed. A method is provided which includes a fourth step of exposing the object to be treated to a fluorine-containing gas at a second temperature higher than the first temperature, thereby forming a second recess structure having a wider recess than the first recess structure.

[0009] Furthermore, in the present invention, a member having a recessed structure, The member is provided, the recess structure comprising a first recess structure and a second recess structure formed below the first recess structure, the second recess having a wider recess than the first recess structure. [Effects of the Invention]

[0010] The present invention provides a method for relatively easily manufacturing a member that exhibits high adhesion to other members. Furthermore, the present invention provides a member having such a recessed structure. [Brief explanation of the drawing]

[0011] [Figure 1]It is a diagram schematically showing a reaction mechanism that can occur on the surface of a treated object when an organic compound has no polar functional group. [Figure 2] It is a diagram schematically showing a reaction mechanism that can occur on the surface of a treated object when an organic compound has a polar functional group. [Figure 3] It is a diagram schematically showing a reaction mechanism that can occur on the surface of a treated object when an organic compound has another polar functional group. [Figure 4] It is a diagram schematically showing the optimized three-dimensional structure of molecule X obtained by the ETKDG method and atoms with negative Gasteiger charges. [Figure 5] It is a diagram schematically showing the three-dimensional structure of a structure obtained by adding hydrogen atoms to molecule X, which is obtained by the ETKDG method. [Figure 6] It is a diagram schematically showing a state where a fluorine atom is added to molecule Y to form a composite compound. [Figure 7] It is a diagram schematically showing the structure obtained by optimizing molecule Z by DFT calculation. [Figure 8] It is a diagram showing the relationship between the processing temperature and the etching reaction rate during the hydrogen fluoride (HF) gas etching of glass. [Figure 9] It is a cross-sectional view schematically showing a process of a process according to an embodiment of the present invention. [Figure 10] It is a cross-sectional view schematically showing a process of a process according to an embodiment of the present invention. [Figure 11] It is a diagram schematically showing the flow of a method for manufacturing a member having a concave structure according to an embodiment of the present invention. [Figure 12] It is a perspective view schematically showing a state where a catalyst material is installed on a treated object in a method for manufacturing a member having a concave structure according to an embodiment of the present invention. [Figure 13] It is a cross-sectional view schematically showing an example of a treated object 110 after the formation of a first concave portion in a method for manufacturing a member having a concave structure according to an embodiment of the present invention. [Figure 14]In a method for manufacturing a member having a concave structure according to an embodiment of the present invention, it is a cross-sectional view schematically showing an example of a workpiece 110 after formation of a second concave structure. [Figure 15] It is a perspective view of a member according to an embodiment of the present invention. [Figure 16] It is a schematic cross-sectional view along line A-A of a member according to an embodiment of the present invention shown in FIG. 14. [Figure 17] It is a view schematically showing the form of the surface of the side wall of a first concave structure in a member according to an embodiment of the present invention. [Figure 18] It is a schematic view for explaining the taper angle θ of the first concave structure. [Figure 19] It is a schematic cross-sectional view along line A-A when a resin layer is provided on a member according to an embodiment of the present invention shown in FIG. 14. [Figure 20] It is a view schematically showing the flow of a method for manufacturing a member having a concave structure according to another embodiment of the present invention. [Figure 21] In a method for manufacturing a member having a concave structure according to another embodiment of the present invention, it is a cross-sectional view schematically showing an example of a workpiece 110 after formation of a next first concave structure. [Figure 22] In a method for manufacturing a member having a concave structure according to another embodiment of the present invention, it is a cross-sectional view schematically showing an example of a workpiece 110 after formation of a next second concave structure. [Figure 23] It is a photograph showing an example of a cross-section of a concave structure according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described.

[0013] As described above, in the conventional RIE method, when a concave structure is formed on the surface of a sample, there is a problem that it is difficult to improve the adhesion to other members.

[0014] To address these conventional problems, the inventors of this application have diligently conducted research and development and have discovered a microfabrication technique that improves the adhesion between a given component and other components by forming a recessed structure on the surface of the component.

[0015] In other words, in one embodiment of the present invention, The first step is to prepare a material to be treated that contains elements whose fluoride boiling point is 550°C or lower, A second step involves forming a catalyst material on a part of the surface of the object to be treated, A third step involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed. The fourth step involves exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature to form a second recess structure having a wider recess than the first recess structure. A method for manufacturing a member having a recessed structure is provided.

[0016] A method according to one embodiment of the present invention comprises a process of exposing a workpiece on which a catalyst material is formed on its surface to a fluorine-containing gas at a first temperature of 80°C or higher, and a process of exposing it to a fluorine-containing gas at a second temperature higher than the first temperature (hereinafter, these processes are collectively referred to as the "etching process of the present invention"). By carrying out such an etching process of the present invention, the method according to one embodiment of the present invention can selectively etch the region on the surface of the workpiece where the catalyst material is formed (hereinafter referred to as the "coated region").

[0017] The following explanation, with reference to the drawings, will describe the reasons why such etching is possible as currently understood.

[0018] First, we will explain the role of the catalyst material and the effect of the processing temperature in the etching process of the present invention.

[0019] (Role of catalytic materials) In the etching process of the present invention, the catalyst material comprises an organic compound having a polar functional group. Such an organic compound having a polar functional group is thought to play a role in lowering the activation energy of fluoride formation on the surface of the workpiece.

[0020] The role of this process will be explained below using Figures 1 to 3. Figures 1 to 3 schematically show the reaction on the surface of the object being treated where the catalyst material is placed.

[0021] For the purposes of the following explanation, we will assume that the material to be treated is SiO2 and that its surface is hydrogen-terminated.

[0022] First, Figure 1 schematically shows the expected etching mechanism on the surface of the object to be treated when the organic compound does not have polar functional groups.

[0023] When hydrogen fluoride (HF) gas is supplied from the environment to the area on the surface of the SiO2 material being treated, i.e., the "coating area" where the catalyst material is installed, the HF molecules (a) perform a nucleophilic attack on the Si atoms (b), as shown in (i).

[0024] However, for the Si atom (b) to react with the F atom on the surface of the material being treated, the OH group (c) on the surface must interact with the H atom of the HF molecule (a), as shown in (ii), to weaken the HF bond. In other words, unless enough energy is provided to break the HF bond in the HF molecule (a), the Si-F bond (d) accompanied by the elimination of H2O (g), as shown in (iii), will not form.

[0025] However, in this reaction system, there are no substances that contribute to the decrease in the activation energy of the Si-F bond (d). Therefore, no significant etching reaction proceeds in the coated region.

[0026] In this system, as with conventional mask pattern processing, the etching rate tends to be higher in areas where the workpiece is in direct contact with the HF gas, i.e., in areas where no catalyst material is installed on the surface (hereinafter referred to as the "uncoated area").

[0027] On the other hand, Figure 2 schematically shows the reaction mechanism on the surface of the treated object when the organic compound has a polar functional group. Here, a hydroxyl group is assumed to be the polar functional group.

[0028] In this case as well, when HF gas is supplied from the environment to the coated region of the catalyst material, the HF molecules (a) perform a nucleophilic attack on the Si atoms (b), as shown in (i).

[0029] However, in this case, in addition to the above, the oxygen atom of the -δ part (e) of the polar functional group interacts with the hydrogen atom of the HF molecule (a). Also, the hydrogen atom of the +δ part (f) of the polar functional group interacts with the surface OH group (c).

[0030] Therefore, as shown in (ii), the HF bond in HF molecule (a) is weakened. The Si(b)-OH(c) bond is also weakened. This lowers the activation energy required for the bonding reaction between the Si atom and the F atom.

[0031] As a result, as shown in (iii), the O atom of the -δ part (e) of the polar functional group removes the H atom from the HF molecule (a), and the H atom of the +δ part (f) reacts with the OH group on the surface, resulting in the elimination of H2O (g).

[0032] This causes the Si atom (b) to bond with the fluorine atom. Finally, SiF4 and H2O are formed by the following reaction equation (1). SiO2+4HF → SiF4↑+ 2H2O↑ (1) Both SiF4 and H2O produced in the reaction are gases at the processing temperature and are quickly released from the system.

[0033] Through the reaction mechanism described above, the area directly beneath the coating region of the catalyst material is selectively etched in the object being treated.

[0034] Furthermore, the above reaction is not limited to cases where the polar functional group contains a hydroxyl group. For example, a similar reaction may occur when the polar functional group has at least one of the following: an aldehyde group, a carboxyl group, an amino group, a sulfo group, a thiol group, and an amide bond.

[0035] Furthermore, Figure 2 illustrates the reaction mechanism using the case where the polar functional group of an organic compound contains a hydrogen atom as an example. However, the polar functional groups of organic compounds are not necessarily limited to those containing a hydrogen atom.

[0036] Figure 3 schematically shows the reaction mechanism when an organic compound has another polar functional group. Here, a carbonyl group (>C=O) without a hydrogen atom is assumed as the polar functional group.

[0037] In this example as well, when HF gas is supplied from the environment to the coated region of the catalyst material, the HF molecule (a) performs a nucleophilic attack on the Si atom (b), as shown in (i). In addition, the O atom of the -δ part (e) of the polar functional group interacts with the H atom of the HF molecule (a).

[0038] As a result, the HF bond of HF molecule (a) is weakened, as shown in (ii).

[0039] Next, as shown in (iii), the H atom that was detached from the HF molecule (a) by the O atom of the -δ part (e) of the polar functional group combines with the OH group (c) to produce H2O (g).

[0040] Thus, in this case as well, the activation energy required for the bonding reaction between Si atoms and F atoms decreases. As a result, the reaction shown in reaction equation (2) above occurs, and the area directly beneath the coated region of the object being treated is selectively etched.

[0041] Similar reaction mechanisms can also occur, for example, when the polar functional group has at least one of a nitro group, a cyano group, an ether bond, and an ester bond.

[0042] Thus, in the etching process of the present invention, the presence of an organic compound having a polar functional group contained in the catalyst material promotes the fluoride formation reaction in the coated region of the workpiece, allowing for selective etching of the area directly beneath the coated region.

[0043] Furthermore, the etching process of the present invention may include an organic molecule as a substructure, which, as a catalyst material, has a value of 0.965 (Å) or greater for the distance dHF between a hydrogen atom and a fluorine atom in a hydrogen fluoride molecule, assuming an adsorption structure with an SiO2 surface, calculated using the 6-31+G(d) basis function and the B3LYP correlation-exchange functional.

[0044] Here, dHF is calculated using the following method.

[0045] (How to calculate dHF) First, the structural information of the target organic molecule (hereinafter referred to as "molecule X") is obtained from SMILES using the RDKit library, and a 3D structure is generated using the ETKDG method. The version of RDKit used is 2023.9.4, developed by GitHub and SourceForge, executed in Python 3.10.13, and obtained as open source, with the open-source version being released in June 2006.

[0046] Next, we calculate the Gasteiger charge and identify the atoms with a negative Gasteiger charge (hereinafter referred to as "site atoms P").

[0047] Figure 4 schematically shows, as an example, the optimized structure of molecule X obtained by the above method and the site atom P assigned to molecule X. In this example, molecule X has the general formula primary amine, and there is only one site atom P. In Figure 4, the large gray spheres represent carbon atoms, the black spheres represent nitrogen atoms, and the smallest white spheres represent hydrogen atoms.

[0048] Next, the following procedure is used to add an H atom to molecule X to form a conjugate acid compound (hereinafter referred to as "compound Y"), and to generate the three-dimensional coordinates of compound Y.

[0049] First, a formal charge of 1 is added to the site atom P, and a hydrogen atom is bonded to the site atom.

[0050] Next, the structure is optimized using the ETKDG method to generate the three-dimensional structure of the conjugate acid.

[0051] Figure 5 shows a simulated three-dimensional structure of compound Y, along with site atom P and the added hydrogen atom H. The three-dimensional structure of compound Y thus generated is converted into an SDF file to obtain its three-dimensional coordinates.

[0052] Next, a fluorine atom is positioned 1.0 Å away from the hydrogen atom to which a bond has been added to site atom P, thereby forming a composite compound (hereinafter referred to as "compound Z"), and a three-dimensional structure is generated by the ETKDG method.

[0053] In this case, the site atom P, the hydrogen atom, and the fluorine atom must be arranged in a straight line.

[0054] Figure 6 shows the three-dimensional structure of compound Z, along with a simulated representation of the site atom P, the hydrogen atom H, and the fluorine atom F. The dashed arrows indicate the straight lines they share.

[0055] The three-dimensional structure of compound Z generated by the above procedure is used as the initial structure, and structural optimization is performed using DFT calculations. Figure 7 shows the structure of compound Z after structural optimization by DFT calculations.

[0056] From the obtained optimized structure, the distance dHF between the fluorine atom and the hydrogen atom in the added hydrogen fluoride molecule is calculated.

[0057] If the target compound has multiple site atoms, each atom is treated as a site atom, and the above procedure is repeated until the distance between the fluorine atom and the hydrogen atom in the largest hydrogen fluoride molecule is determined as dHF.

[0058] All DFT calculations are preferably performed using the Gaussian package, and structural optimization is performed using the DFT method, 6-31+G(d) basis functions, B3LYP correlation-exchange functional, default spin, ±0 charge, and singlet state. The version of Gaussian used is Gaussian16, developed by Carnegie Mellon University, available through a paid license agreement, and first released in 1970.

[0059] Here, for atomic species with atomic numbers greater than Kr, we use LanL2DZ as the basis set.

[0060] Similarly, dHF can be calculated for other basis functions and correlation-exchange functionals other than the 6-31+g(d) basis function and the B3LYP correlation-exchange functional.

[0061] The basis set requirements include having outer shell orbitals at or above the DZ level or TZ level, with the diffuse function added.

[0062] Although the absolute value of dHF defined in this invention does not match the calculated values ​​for other basis functions and correlation-exchange functionals, the trends match with good accuracy.

[0063] Specific examples of substructures of organic molecules with a dHF value of 0.965 (Å) or higher include structures containing an amino group or phosphorus, and organic compounds having at least one ring structure containing at least one of nitrogen and oxygen.

[0064] When an organic compound having the above-mentioned functional group is used, electron donation occurs from the organic compound to the antibonding orbital of HF, increasing the bond length between HF atoms. This is expected to increase the basicity of F and its nucleophilicity to nearby Si atoms, thus increasing reactivity.

[0065] Examples of organic compounds having a phosphorus-containing structure include the following compounds.

[0066] [ka]

[0067] Examples of organic compounds having a ring structure containing at least one of nitrogen and oxygen include the following compounds.

[0068] [ka]

[0069] Furthermore, the following compounds are examples of organic compounds that contain an amino group.

[0070] [ka]

[0071] Furthermore, the organic compound having a functional group contained in the organic catalyst material according to one embodiment of the present invention does not necessarily have to be just one type, but may be used in a mixture of two or more types.

[0072] An organic catalyst material according to one embodiment of the present invention has crosslinking properties. Here, "having crosslinking properties (organic compound)" means that when light or heat is applied to the material in question, a crosslinked material is formed from the material.

[0073] In one embodiment of the present invention, the material may be one that exhibits crosslinking properties on its own (hereinafter referred to as a "crosslinkable organic molecule") or one that does not exhibit crosslinking properties on its own (hereinafter referred to as a "non-crosslinkable organic molecule"). In the latter case, the organic catalyst material according to one embodiment of the present invention further comprises a crosslinking agent.

[0074] However, even in the former case, the organic catalyst material according to one embodiment of the present invention may further contain a crosslinking agent. In this case, the presence of the crosslinking agent accelerates the conversion from crosslinkable organic molecules to crosslinked products.

[0075] An organic catalyst material according to one embodiment of the present invention may have other additives in addition to, or separately from, the crosslinking agent.

[0076] (Crosslinking agent) As described above, the organic catalyst material according to one embodiment of the present invention may contain a crosslinking agent.

[0077] Crosslinking agents are not limited to these, but include, for example, TADT (N,N',N''-triacryloydiethylenetriamine) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), MT3041 (manufactured by Toagosei Co., Ltd.), EX512 (manufactured by Nagase ChemteX Corporation), and PETA (Pentaerythritol triacrylate; manufactured by Shin Nakamura Chemical Co., Ltd.).

[0078] TADT and PETA are represented by the following structural formulas (11) and (12), respectively.

[0079] [ka] The amount of crosslinking agent added is not particularly limited. For example, the crosslinking agent may be added in an amount ranging from 0 mol% to 90 mol% of the total amount of the organic compound having the aforementioned polar functional group and the crosslinking agent.

[0080] (Additives) The organic material according to one embodiment of the present invention may contain various additives.

[0081] The additives are not limited to these, but may include, for example, photoradical initiators, photoacid generators, photobase generators, thermal acid generators, or thermal base generators.

[0082] The amount of additive added may be, for example, in the range of 0.1 mol% to 20 mol% relative to the total amount of the organic material according to one embodiment of the present invention, and preferably in the range of 0.1 mol% to 5 mol%.

[0083] (Effect of processing temperature) Next, we will explain the effect of processing temperature.

[0084] In the etching process of the present invention, the processing temperature is 80°C or higher. This is because, below 80°C, proper etching selectivity does not occur between the coated and uncoated areas on the surface of the workpiece.

[0085] The effects of processing temperature will be explained in more detail below, with reference to Figure 8.

[0086] Figure 8 shows the relationship between processing temperature and etching reaction rate during hydrogen fluoride (HF) gas etching of glass, as obtained by the inventors of the present invention.

[0087] Figure 8 shows that the etching rate of glass gradually increases with temperature up to 80°C. However, above 80°C, the etching rate decreases sharply. As a result, the etching rate peaks at temperatures below 80°C.

[0088] This phenomenon is thought to correspond to the associated / unassociated states of HF gas. Specifically, HF gas is in an associated state below 80°C, but becomes unassociated (elementary) above 80°C. Furthermore, when HF gas is in an associated state, the bonding force of the HF bond is relatively weaker when viewed as a single molecule. Consequently, the fluorine atoms of the HF molecule become more likely to bond with the surface of the material being treated, making it easier to form fluorides. This behavior is thought to be the reason why high etching rates can be obtained below 80°C.

[0089] In the etching process of the present invention, if the processing temperature is set below 80°C, the effects of the association state of HF gas will occur, and the workpiece will be etched in the uncoated region of the catalyst material. Consequently, the etching selectivity in the coated region due to the aforementioned reaction mechanism will decrease.

[0090] In contrast, when the processing temperature is set to 80°C or higher, the high etching force due to the associated HF gas can be suppressed in the uncoated region of the catalyst material. Furthermore, based on the reaction mechanism described above, etching of the workpiece becomes possible directly beneath the coated region. As a result, the etching process of the present invention (processing temperature of 80°C or higher) can achieve high etching selectivity between the coated and uncoated regions of the catalyst material. Moreover, this allows for selective etching of the coated region in the etching process of the present invention.

[0091] (The recessed structure that is formed) Conventional RIE methods make it difficult to form recessed structures where the interior is wider than the opening.

[0092] In contrast, the etching process of the present invention makes it relatively easy to form a recessed structure in which the interior is wider than the opening. Specifically, the etching process of the present invention forms a recessed structure having a first recessed structure and a second recessed structure. The first recessed structure has a first width and is formed by a process of exposure to a fluorine-containing gas at a first temperature of 80°C or higher. The second recessed structure has a second width that is wider than the first width and is formed by a process of exposure to a fluorine-containing gas at a second temperature higher than the first temperature. The etching process of the present invention makes it relatively easy to make the first recessed structure a recessed structure that does not have a "tapered shape" and has side walls that extend substantially parallel to the extension axis in the depth direction (hereinafter referred to as a "vertical recessed structure").

[0093] The reason for this will be explained below with reference to Figures 9 and 10.

[0094] Figures 9 and 10 schematically illustrate one step in a process involving exposure to a fluorine-containing gas at a first temperature of 80°C or higher.

[0095] Figure 9 schematically shows the state in which the catalyst material 3 is placed on the surface of the object to be treated 1. Note that in Figures 9 and 10, for illustrative purposes, the object to be treated 1 and the catalyst material 3 are shown to be separated from each other, but in reality, they are in contact.

[0096] As mentioned above, it is assumed that the object to be treated 1 is SiO2 and that its surface is H-terminated.

[0097] The catalyst material 3 is an organic compound having a polar functional group, and here, an OH group is assumed to be the polar functional group. By placing the catalyst material 3 on the surface of the object to be treated 1, a coated region 8a and an uncoated region 8b are formed on the object to be treated 1.

[0098] As described above, by exposing the workpiece 1, heated to 80°C or higher, to HF gas, selective etching proceeds directly beneath the coated region 8a where the catalyst material 3 is installed. This forms a first recessed structure directly beneath the coated region 8a. The size of the HF molecules is sufficiently smaller than the size of the voids within the catalyst material 3. Therefore, when the workpiece 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 workpiece 1.

[0099] Figure 10 shows a state in which etching of the workpiece 1 has progressed to a certain extent, and a first recessed structure 5 of a certain depth has been formed.

[0100] As mentioned above, catalyst material 3 is placed in the coated region 8a. Therefore, even as the etching reaction proceeds, catalyst material 3 remains on the bottom surface 6 of the first recessed structure 5. In other words, as long as the etching process continues, the bottom surface 6 of the first recessed structure 5 remains in contact with catalyst material 3. As a result, the bottom surface 6 of the first recessed structure 5 continues to be etched by the reaction mechanism described above, and the etching of the bottom surface 6 continues in the depth direction.

[0101] On the other hand, focusing on the side wall 7 of the first recess structure 5, once etching begins, the etching reaction proceeds in the portion of the side wall 7 that is in contact with the catalyst material 3, according to the mechanism described above. More precisely, only the portion of the workpiece 1 that is in contact with the side surface of the catalyst material 3 is etched. As a result, the first recess structure 5, partitioned by the side wall 7, is formed in the portion that is in contact with the side surface of the catalyst material 3.

[0102] However, as the catalyst material 3 continues to descend deeper, beyond a certain point, the upper part of the side wall 7 no longer comes into contact with the side surface of the catalyst material 3. Hereinafter, this side wall 7 that is no longer in contact with the side surface of the catalyst material 3 will be referred to as the "first side wall portion 7a".

[0103] As mentioned above, in areas where the catalyst material 3 is not present, such as the uncoated region 8b, etching does not substantially proceed. In other words, in the workpiece 1, the etching reaction occurs only when it is in contact with the catalyst material 3, and does not occur in any other state. For this reason, in the sidewall 7, in areas that have lost contact with the catalyst material 3, such as the first sidewall portion 7a, the etching process effectively stops thereafter.

[0104] This is a crucial difference from conventional dry etching methods such as the RIE method. In the RIE method, even areas where etching is already complete, such as near openings on the surface of the workpiece, continue to be exposed to the reaction gas during the etching process. Therefore, the continuation of the etching process increases the likelihood of the formation of a first recessed structure with a tapered shape.

[0105] In the etching process of the present invention, as a result of the etching stopping action at the first sidewall portion 7a that does not come into contact with the catalyst material 3, etching of the workpiece 1 selectively proceeds only directly beneath the catalyst material 3 (anisotropic etching), and ultimately the first recessed structure can be transformed into a vertical recessed structure.

[0106] Due to the effects described above, the etching process of the present invention makes it possible to form a characteristic vertical recess structure as the first recess structure 5.

[0107] In the etching process of the present invention, a second recessed structure is formed after a first recessed structure is formed. The second recessed structure has a second width that is wider than the first, and is formed by a process of exposure to a fluorine-containing gas at a second temperature that is higher than the first temperature. The second temperature is the temperature at which at least a portion of the organic compounds having polar functional groups contained in the catalyst material volatilizes from the catalyst material. Therefore, when exposed to a fluorine-containing gas at the second temperature, etching proceeds even in areas near the catalyst material that are not in contact with it (isotropic etching).

[0108] After the first recessed structure is formed, the catalyst material is in contact with the bottom surface of the first recessed structure. In this state, when the member is exposed to a fluorine-containing gas at a second temperature, isotropic etching proceeds near the bottom surface of the first recessed structure, and a second recessed structure, which is wider than the first recessed structure, is formed near the bottom surface of the first recessed structure.

[0109] The etching process of the present invention further has the following additional effects: (I) It is possible to form deep recessed structures. In the conventional RIE method, SiO x There is a limit to the etching depth; for example, when using photoresist as a masking agent, it is difficult to form deep recessed structures such as 20 μm deep.

[0110] However, in the etching process of the present invention, the etching reaction proceeds as long as the supply of fluorine-containing gas to the coated area continues. Therefore, it is possible to form recessed structures with a high aspect ratio. For example, aspect ratios of 10 or more can be achieved.

[0111] Note that "aspect ratio" refers to the depth dimension relative to the minimum dimension of the opening in a recessed structure. (II) Rapid etching is possible Conventional RIE methods have a processing speed of approximately 1 μm / min or less, which makes it difficult to consider them a sufficiently high-speed microfabrication technology.

[0112] In contrast, the etching process of the present invention enables rapid etching by increasing the amount of catalyst material installed and / or the amount of fluorine-containing gas supplied. Therefore, the etching process of the present invention can be used as a rapid recess structure formation technique.

[0113] (Method for manufacturing a member having a recessed structure according to one embodiment of the present invention) Next, with reference to Figures 11 to 14, a method for manufacturing a member having a recessed structure according to one embodiment of the present invention will be described in more detail.

[0114] Figure 11 schematically shows a flow chart of a method for manufacturing a member having a recessed structure according to one embodiment of the present invention.

[0115] As shown in Figure 11, the method for manufacturing a member having a recessed structure according to the present invention (hereinafter also referred to as "the manufacturing method according to the present invention") is as follows: The first step (S110) is to prepare a workpiece containing an element whose fluoride boiling point is 550°C or lower, The second step (S120) is to form a catalyst material on a part of the surface of the object to be treated, A third step (S130) involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed, The method comprises a first step (S140) of exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature to form a second recess structure having a wider recess than the first recess structure.

[0116] The following explains each step.

[0117] (Step S110) First, the object to be processed is prepared.

[0118] The object to be processed may be composed of a single component or multiple components.

[0119] When the object to be treated is composed of a single component, the object to be treated is composed of an element that, upon reaction with fluorine (F), forms a fluoride with a boiling point of 550°C or lower.

[0120] For example, the material to be treated may contain at least one element selected from the group consisting of B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au. Furthermore, the material to be treated may also contain at least one element selected from the group consisting of H, N, Cl, Br, and O.

[0121] In particular, it is preferable that the material to be treated is composed of an element that, upon reaction with fluorine, forms a fluoride with a boiling point of 200°C or lower.

[0122] For example, silicon (Si) has a boiling point of -86°C as fluoride SiF4, and a material containing silicon can be suitably used as a material to be treated in the manufacturing method according to the present invention.

[0123] Furthermore, the boiling points of the fluorides (AlF3) and (CaF2), respectively, of Al and Ca exceed 550°C. Therefore, Al and Ca cannot be said to be elements that form fluorides with a boiling point below 550°C through reaction with fluorine (F).

[0124] The material to be processed may be, for example, a quartz glass substrate, a crystal substrate, or a silicon substrate.

[0125] On the other hand, if the object to be treated is composed of a laminate of multiple components, the object to be treated contains an element whose fluoride boiling point is 550°C or lower on its outermost surface.

[0126] As mentioned above, such elements may be selected from the group consisting of, for example, B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au. The first surface may also further contain at least one element selected from the group consisting of H, N, Cl, Br, and O.

[0127] For example, the object to be processed may have one or more films placed on a substrate, and the outermost film may satisfy the aforementioned characteristics. Alternatively, the entire group of films may satisfy the aforementioned characteristics.

[0128] Such films include, for example, one or more selected from the group consisting of oxides, carbides, and nitrides of Si. Such films include, for example, SiO x SiN yIt may have at least one of SiCN, SiON, and SiC.

[0129] Alternatively, the substrate, along with the film, may also have the aforementioned characteristics. In this case, the manufacturing method according to the present invention can produce a component in which a recessed structure is formed even inside the substrate. The substrate may be, for example, a quartz glass substrate, a crystal substrate, or a silicon substrate.

[0130] For the sake of simplicity, in the following explanation, we will assume that the object to be treated is composed of a single piece of quartz glass, and that a recessed structure is formed on the surface of the quartz glass.

[0131] (Step S120) Next, a catalyst material is formed on a portion of the surface of the object to be treated. The catalyst material is placed in a predetermined area on the surface.

[0132] The catalyst material can be any of the materials described above. Specifically, the catalyst material may include an organic compound having a polar functional group. Examples of polar functional groups include a hydroxyl group, aldehyde group, carboxyl group, amino group, sulfo group, thiol group, amide bond, carbonyl group, nitro group, cyano group, ether bond, and ester bond. The catalyst material may also be an organic compound having a phosphorus-containing structure and at least one ring structure containing at least one of nitrogen and oxygen.

[0133] Typical examples of such organic compounds include phenolic resins, acrylic resins, and methacrylic resins.

[0134] The catalyst material may consist solely of organic compounds having the aforementioned polar functional groups, or it may be provided as a mixture with other additives.

[0135] In the latter case, the catalyst material may include a solvent, a binder, and / or fine particles, etc.

[0136] There are no particular restrictions on the method of installing the catalyst material.

[0137] The catalyst material may be applied to the surface of the object to be treated by methods such as coating, printing, spin coating, or spraying.

[0138] Figure 12 schematically shows how the catalyst material is installed on the object to be treated.

[0139] As shown in Figure 12, the object to be treated 110 has a front surface 112 and a back surface 114. The catalyst material 130 is placed on a portion of the front surface 112 of the object to be treated 110.

[0140] In the example shown in Figure 12, the catalyst material 130 is arranged as a plurality of parallel linear patterns 131. However, this is merely one example, and the catalyst material 130 may be arranged in any manner depending on the required recessed structure. The catalyst material 130 may be arranged, for example, as a single straight line. Alternatively, the catalyst material 130 may be arranged, for example, as a pattern of circular dots, or as a single circular dot.

[0141] The thickness of the catalyst material 130 is not particularly limited, but may be in the range of, for example, 0.01 μm to 10 μm. According to the definition above, on the surface 112, the area on which the catalyst material 130 is installed is referred to as the coated area 140a, and the other areas are referred to as the uncoated area 140b.

[0142] (Step S130) Next, the workpiece 110 is exposed to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece 110 where the catalyst material 130 is formed. Specifically, the workpiece 110 with the catalyst material 130 installed is placed inside a processing chamber. Subsequently, the processing chamber is heated to the first temperature and a processing gas is supplied for etching the workpiece.

[0143] The processing gas contains hydrogen fluoride gas or fluorine gas. For example, the processing gas may be adjusted to a predetermined concentration using a carrier gas such as argon gas or nitrogen gas. In this case, the concentration of hydrogen fluoride gas or fluorine gas may be in the range of, for example, 0.1 vol% to 100 vol%. The temperature of the processing gas may also be in the range of, for example, 80°C to 300°C. 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.

[0144] As mentioned above, the first temperature is 80°C or higher. The actual processing temperature varies depending on the type of catalyst material, the elements contained in the workpiece 110 (especially the surface 112), and the type and depth of the recessed structure, but is usually in the range of 200°C to 300°C, and preferably in the range of 250°C to 300°C. By setting the first temperature to 300°C or lower, the volatilization of organic compounds contained in the catalyst material 130 can be suppressed.

[0145] As described above, etching the workpiece 110 under these conditions causes the reaction equation (1) to occur in the coated region 140a. The fluoride and water produced by the reaction escape out of the system as gas. As a result, the first recessed structure is formed in the coated region 140a of the surface 112.

[0146] Figure 13 schematically shows an example of a cross-section of the workpiece 110 after the formation of the first recess structure.

[0147] In the example shown in Figure 13, the first recess structure 150 is composed of multiple grooves, and in a top view, each groove extends parallel to the others. Furthermore, the side walls of the first recess structure 150 extend substantially parallel to the extension axis in the depth direction.

[0148] (Step S140) Next, the workpiece 110 is exposed to a fluorine-containing gas at a second temperature, which is higher than the first temperature, to form a second recessed structure with a wider recess than the first recessed structure. Specifically, after forming the first recessed structure on the workpiece 110 in the processing chamber, the processing chamber is heated to the second temperature and the processing gas is supplied. When changing the temperature in the processing chamber from the first temperature to the second temperature, the temperature may be increased in stages or continuously. The temperature of the processing gas may also be in the range of, for example, 200°C to 500°C.

[0149] As mentioned above, the second temperature is higher than the first temperature. The actual processing temperature is usually in the range of 200°C to 500°C, and preferably in the range of 250°C to 450°C. By setting the processing temperature to 500°C or lower, the carbonization of organic compounds contained in the catalyst material 130 can be suppressed.

[0150] As described above, etching of the workpiece 110 under these conditions generates the reaction equation (1) near the catalyst material. The fluoride and water produced by the reaction escape out of the system as gases. As a result, a second recessed structure is formed near the bottom surface of the first recessed structure.

[0151] Figure 14 schematically shows an example of a cross-section of the workpiece 110 after the formation of the second recess structure.

[0152] In the example shown in Figure 14, the second recess structure 151 is located on the bottom side of each first recess structure 150. The second width of the second recess structure 151 is wider than the first width of the first recess structure 150. The first and second widths are dimensions in the direction perpendicular to the depth direction.

[0153] Furthermore, after step S140, a step may be performed to remove the catalyst material 130 remaining on the bottom surface of the second recessed structure 151. For example, the catalyst material 130 may be removed by washing the workpiece 110 with an acid solution, an alkaline solution, an organic solvent, a corrosive gas, or plasma.

[0154] Through the above process, a member 100 having a first recessed structure 150 and a second recessed structure 151 can be manufactured.

[0155] 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. The acidic gas has the effect of enhancing the catalytic activity during etching by reacting with the catalyst material. Alternatively, an oxidizing gas such as oxygen gas may be added as an additive gas to the fluorine-containing gas. For example, when etching a Si substrate, the Si substrate may be oxidized using an oxidizing gas before etching using the above method.

[0156] Furthermore, a gas that forms a deposited film together with a fluorine-containing gas may be used. By including a gas that forms a deposited film in the etching gas, the etching rate on the side walls of the recessed structures can be reduced during etching, thereby improving the rectangularity of the recessed structures. 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 structures 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 structures of the substrate.

[0157] In addition, the present invention may further include a step between step S120 and step S130 in which the catalyst material is irradiated with irradiation light including deep ultraviolet (DUV) light with a wavelength of 380 nm or less (hereinafter referred to as the "DUV irradiation process"). When such a DUV irradiation process is added, it becomes possible to control the etching rate of the workpiece during the subsequent etching process. The reason why the etching rate of the workpiece can be controlled by performing the etching process after the DUV irradiation process is thought to be because the number of polar functional groups changes due to the DUV irradiation process.

[0158] In other words, when a DUV irradiation process is performed, exposure to deep ultraviolet light with a wavelength of 380 nm or less results in a crosslinking reaction within the catalyst material 3. This crosslinking reaction reduces the number of polar functional groups (e.g., C-OH groups) contained in the catalyst material 3. Therefore, during the subsequent etching process, the effect of reducing the reaction barrier in the reaction of reaction equation (1) described above is weakened, and the etching rate is thought to decrease.

[0159] Furthermore, in this case, the number of polar functional groups contained in the catalyst material 3 also changes by changing the irradiation intensity of the irradiation light, including deep ultraviolet light, and the irradiation time of the irradiation light during the DUV irradiation process. Therefore, by changing the irradiation conditions in the DUV irradiation process, the etching rate of the workpiece 1 can be controlled during the etching process.

[0160] For example, when forming relatively shallow recessed structures, the irradiation intensity of the light in the DUV irradiation process may be increased and / or the irradiation time may be extended. This significantly reduces the etching rate in the etching process and prevents over-etching of the workpiece.

[0161] Furthermore, when forming relatively deep recessed structures, the irradiation intensity of the light used in the DUV irradiation process may be reduced, and / or the irradiation time may be shortened. This increases the etching rate in the etching process and reduces the processing time.

[0162] Thus, basic etching technology allows for the manufacture of components with vertical recess structures at various etching rates.

[0163] (Member having a recessed structure according to one embodiment of the present invention) Next, with reference to Figures 15 to 18, a member having a recessed structure according to one embodiment of the present invention will be described.

[0164] Figure 15 shows a perspective view of a member having a recessed structure according to one embodiment of the present invention (hereinafter referred to as "the first member 200"). Figure 16 shows a schematic cross-sectional view of the first member 200 shown in Figure 15 along line AA.

[0165] As shown in Figure 15, the first member 200 has a surface 202 and a back surface 204 that face each other. The first member 200 also has a recessed structure 250 on the side of the surface 202.

[0166] In the example shown in Figure 15, the front surface 202 and back surface 204 of the first member 200 are substantially rectangular in shape. However, the shape of the front surface 202 and back surface 204 is not particularly limited.

[0167] Furthermore, in the example shown in Figure 14, the recessed structure 250 has the shape of a bottomed groove extending in one direction, and three recessed structures 250 are arranged in parallel.

[0168] However, this is merely an example, and the shape and arrangement of the recessed structure 250 are not particularly limited. For example, the recessed structure 250 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 250 may take any form.

[0169] As shown in Figure 16, the recessed structure 250 has an opening 252 on the surface 202. The recessed structure 250 also has a first recessed structure 256 and a second recessed structure 257.

[0170] The first component 200 can be manufactured, for example, by the manufacturing method according to the present invention as described above.

[0171] Here, the first member 200 is characterized in that the first recessed structure 256 has a streak pattern along the depth direction.

[0172] This feature will be explained below with reference to Figure 17.

[0173] Figure 17 schematically shows the surface morphology of the first recess structure 256 of the recess structure 250. Figure 16 schematically shows a portion of the side wall of the first recess structure 256 obtained when the recess structure 250 is cut along the extension axis in the direction along the surface 202 of the first member 200 and the extension axis in the depth direction.

[0174] As shown in Figure 17, in the first member 200, continuous, uninterrupted lines (hereinafter referred to as "continuous lines") 280 are formed on the side wall of the first recess structure 256, extending in the depth direction from the opening 252.

[0175] Note that in Figure 17, three continuous muscle 280s are shown. However, this is merely an example, and the number of continuous muscle 280s is not particularly limited.

[0176] Such continuous reinforcement patterns 280 are significant and not observed in conventionally etched components. In other words, the continuous reinforcement patterns 280 are a unique feature observed in the first component 200 manufactured by the manufacturing method according to the present invention as described above.

[0177] This pattern of 280 continuous fibers is thought to be formed for the following reasons.

[0178] As explained with reference to Figures 9 and 10 above, in the manufacturing method according to the present invention, the coated region 8a is selectively etched by the catalyst material 3 placed on the coated region 8a. Furthermore, as long as the relationship between the catalyst material 3 and the coated region 8a continues, the first recessed structure 5 continues to advance in the depth direction.

[0179] In such an etching mechanism, the sidewall 7 of the first recess structure 5 formed by etching is affected by the state of the side surface of the catalyst material 3 that the sidewall 7 is in contact with.

[0180] In other words, if the side surface of the catalyst material 3 has irregularities, the side wall 7 of the first recess structure 5 is thought to have a surface state with corresponding irregularities, reflecting the influence of such irregularities on the side surface of the catalyst material 3.

[0181] Furthermore, in the manufacturing method according to the present invention, the catalyst material 3 having such irregularities on its side surface progresses along the depth direction of the first recessed structure 5. Therefore, it is considered that a pattern of continuous lines 280 corresponding to such irregularities is formed on the side wall 7 of the final obtained first recessed structure 5.

[0182] In addition to the features described above, or separately therefrom, the first member 200 may have the feature that the taper angle θ of the first recess structure 5 is in the range of 0° to 2°.

[0183] This feature will be explained below with reference to Figure 18. Figure 18 schematically shows a cross-section of the member after the first recessed structure has been formed but before the second recessed structure has been formed.

[0184] Figure 18 schematically shows a cross-section of a first recessed structure along the extension axis L.

[0185] This first recessed structure 50 has an opening 52 on the surface of the member. The first recessed structure 50 also has a side wall 57.

[0186] Although not clear from Figure 18, the first recessed structure 50 may be a round hole or a rectangular groove when viewed from above. Furthermore, the first recessed structure 50 may be a through-structure. In that case, the first recessed structure 50 may have a second opening instead of a bottom surface 56.

[0187] For such a first recessed structure 50, the taper angle θ is determined as follows:

[0188]

number

[0189] The taper angle θ expressed by equation (1) serves as an indicator of the "perpendicularity" of the first recess structure 50. That is, the smaller the taper angle θ, the more the inclination of the side wall 57 of the first recess structure 50 with respect to the extension axis L is suppressed, and such a first recess structure 50 can be said to be close to a "vertical recess structure". In particular, in the first member 200, if the taper angle θ of the first recess structure 256 is in the range of 0° to 2°, the first recess structure can be said to have a vertical recess structure.

[0190] In the first member 200, the taper angle θ of the first recess structure 256 may be 1° or less.

[0191] Furthermore, in the first member 200, the depth of the first recess structure 256 may be 1 μm or more. In particular, in the first member 200, the depth of the first recess structure 256 is, for example, 2 μm or more, and preferably 3 μm or more.

[0192] (Other features of the first component 200) The first member 200 may be a single member or may be composed of multiple members.

[0193] When the first member 200 is composed of a single member, the first member 200 is composed of an element that, upon reaction with fluorine (F), forms a fluoride with a boiling point of 550°C or lower.

[0194] For example, the first member 200 may contain at least one element selected from the group consisting of B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au. The material to be treated may further contain at least one element selected from the group consisting of H, N, Cl, Br, and O.

[0195] When the first member 200 is composed of a single member, the first member 200 may be, for example, a quartz glass substrate or a quartz crystal substrate.

[0196] On the other hand, when the first member 200 is composed of a plurality of members, the first member 200 contains an element with a fluoride boiling point of 550 °C or lower on the surface 202.

[0197] As described above, such an element may be selected from the group consisting of, for example, B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au. Further, the surface 202 may further contain at least one element selected from the group consisting of H, N, Cl, Br, and O.

[0198] For example, the first member 200 may have one or more films provided on a substrate material, and the outermost film may satisfy the above characteristics. Alternatively, the entire plurality of films may satisfy the above characteristics.

[0199] Such a film contains, for example, one or more selected from the group consisting of oxides, carbides, and nitrides of Si. Such a film may have, for example, at least one of SiO x , SiN y , SiCN, SiON, and SiC. Alternatively, together with the film, the substrate material may also have the above characteristics. Note that x of SiO x is a number satisfying 0 < x, and preferably 1.2 ≤ x ≤ 2. Also, y of SiN y is a number satisfying 0 < y, and preferably 0.8 ≤ y ≤ 4 / 3.

[0200] The first member 200 having such characteristics can be applied to various uses such as, for example, MEMS devices, microfluidic devices, semiconductor devices, optical devices, metasurface devices, molds for resin molding, window glass, and cover glass.

[0201] Furthermore, the first member 200 may have a resin layer 300 provided on its surface. The resin layer 300 is an example of a member that adheres closely to the first member 200. The resin layer 300 may be, for example, a sealing material.

[0202] Figure 19 schematically shows an example of a cross-section along line AA when a resin layer is provided on a member according to one embodiment of the present invention.

[0203] In the example shown in Figure 19, the resin layer 300 is provided on the surface of the first member 200 after the recessed structure is provided in the first member 200. Therefore, the resin layer 300 is provided so as to fit into the recessed structure 250. Since the recessed structure 250 has a structure in which the interior is wider than the opening, it has high adhesion with the resin layer 300 due to the anchoring effect.

[0204] (Method for manufacturing a member having a recessed structure according to another embodiment of the present invention) In the embodiments described above, a case was described in which one recess structure has one first recess structure and one second recess structure. However, one recess structure may have multiple first recess structures and multiple second recess structures. Below, as an example, a case in which one recess structure has two first recess structures and two second recess structures will be described.

[0205] Referring to Figures 20 to 22, a method for manufacturing a member having a recessed structure according to another embodiment of the present invention will be described.

[0206] Figure 20 schematically shows a flowchart of a method for manufacturing a member having a recessed structure according to another embodiment of the present invention.

[0207] As shown in Figure 20, the method for manufacturing a member having a recessed structure according to the present invention (hereinafter also referred to as "the manufacturing method according to the present invention") is as follows: The first step (S210) is to prepare a workpiece containing an element whose fluoride boiling point is 550°C or lower, The second step (S220) is to form a catalyst material on a part of the surface of the object to be treated, A third step (S230) involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed, The first step (S240) involves exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature to form a second recess structure having a wider recess than the first recess structure, A fifth step (S250) involves exposing the workpiece to a fluorine-containing gas at the first temperature to form a subsequent first recessed structure, The process includes a sixth step (S260) of exposing the workpiece to a fluorine-containing gas at the second temperature to form a second recessed structure.

[0208] The following explains each step.

[0209] (Steps S210 to S240) Steps S210 to S240 are the same as steps S110 to S140 described above, so their explanation will be omitted.

[0210] (Step S250) After forming the second recessed structure, the workpiece 110 is exposed to a fluorine-containing gas at a first temperature of 80°C or higher to form a subsequent first recessed structure at the bottom of the second recessed structure. Specifically, after forming the second recessed structure in the workpiece 110 within the processing chamber, the processing chamber is cooled to a first temperature and the processing gas is supplied.

[0211] The first temperature is the temperature at which the volatilization of organic compounds contained in the catalyst material 130 is suppressed. Therefore, when the inside of the processing chamber is cooled to the first temperature, anisotropic etching proceeds, and the next first recessed structure is formed.

[0212] Figure 21 schematically shows an example of a cross-section of the workpiece 110 after the formation of the next first recess structure. In the example shown in Figure 21, the next first recess structure 150 is formed on the bottom side of each second recess structure 151.

[0213] (Step S260) Next, the workpiece 110 is exposed to a fluorine-containing gas at a second temperature to form a second recessed structure. Specifically, after forming a first recessed structure on the workpiece 110 in the processing chamber, the processing chamber is heated to a second temperature and a processing gas is supplied.

[0214] As mentioned above, the second temperature is the temperature at which the organic compounds contained in the catalyst material 130 volatilize. Therefore, when the processing chamber is heated to the second temperature, isotropic etching proceeds, and the next second recessed structure is formed.

[0215] Figure 22 schematically shows an example of a cross-section of the workpiece 110 after the formation of the second recess structure.

[0216] In the example shown in Figure 22, the next second recess structure 151 is configured on the bottom side of each subsequent first recess structure 150. Thus, in another embodiment of the present invention, two first recess structures and two second recess structures are alternately provided in one recess structure.

[0217] Through the above process, a member 100 having a first recessed structure 150 and a second recessed structure 151 can be manufactured.

[0218] The above example described a case in which two first recess structures and two second recess structures are provided in one recess structure. However, the number of first recess structures and second recess structures provided in one recess structure is not particularly limited, and two or more of each may be provided. By repeatedly performing steps S250 and S260 alternately, a desired number of first recess structures and second recess structures can be provided. [Examples]

[0219] (Example 1) A recessed structure was formed on one surface of the processed object using the following method.

[0220] The i-line resist used contains a novolac resin represented by the following chemical formula.

[0221] First, a quartz glass substrate was prepared as the treatment object. A coating solution containing a catalyst material was also prepared. An i-line resist was used as the catalyst material, and the coating solution was prepared by mixing it with solvents (ethyl lactate, n-butyl acetate).

[0222] [ka] Therefore, the i-line resist has a hydroxyl group as a polar functional group.

[0223] Next, a coating solution was applied to the substrate surface by spin coating. Furthermore, a pattern of catalyst material was applied to the substrate surface by exposure and development. The pattern was a circular pattern with a diameter of approximately 10 μm.

[0224] Next, the substrate on which the catalyst material pattern was installed was cut to dimensions of approximately 50 mm x 50 mm, and the cut sample was placed in the processing chamber. Gas etching treatment of the sample was then performed in the processing chamber. A mixed gas of nitrogen gas and hydrogen fluoride gas (HF: 20 vol%, N2: 80 vol%) was used as the etching gas. After processing at a temperature of 250°C for 10 minutes, the temperature in the processing chamber was increased to 350°C and processed for another 10 minutes.

[0225] The processed material obtained after etching is referred to as "Sample 1".

[0226] (evaluation) In Sample 1, the cross-section of the recessed structure was observed using a scanning electron microscope (SEM).

[0227] Figure 23 shows examples of cross-sections of the recessed structures obtained in Sample 1.

[0228] From this photograph, it was confirmed that in Sample 1, a recessed structure was formed on the surface, with the interior being wider than the opening.

[0229] (One aspect of the present invention) The present invention may have the following embodiments.

[0230] (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 elements whose fluoride boiling point is 550°C or lower, A second step involves forming a catalyst material on a part of the surface of the object to be treated, A third step involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed. The fourth step involves exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature to form a second recess structure having a wider recess than the first recess structure. Manufacturing method. (Aspect 2) The manufacturing method according to embodiment 1, wherein in the third step, the catalyst material promotes fluoride formation at the interface with the workpiece. (Aspect 3) The second temperature is the temperature at which the reaction-promoting substance volatilizes from the catalyst material. In the fourth step, the volatile reaction-promoting substance is used to accelerate etching with the fluorine-containing gas, and the workpiece is subjected to isotropic etching to form the second recessed structure. The manufacturing method described in embodiment 1 or 2. (Aspect 4) The first temperature is 80°C or higher and 300°C or lower. The second temperature is 300°C or higher. A manufacturing method according to any one of embodiments 1 to 3. (Appendix 5) The third and fourth steps are each performed alternately two or more times. A manufacturing method according to any one of embodiments 1 to 4. (Aspect 6) The catalyst material is the production method according to any one of Aspects 1 to 5, including an organic compound having a polar functional group. (Aspect 7) The catalyst material is an organic compound having one or more polar functional groups selected from a hydroxy group, an aldehyde group, a carboxy group, an amino group, a sulfo group, a thiol group, an amide bond, a carbonyl group, a nitro group, a cyano group, an ether bond, and an ester bond; and an organic compound having one or more structures selected from the group consisting of a structure containing phosphorus and a ring structure containing at least one of nitrogen and oxygen; The production method according to any one of Aspects 1 to 6, which has one or more selected. (Aspect 8) The production method according to Aspect 6, further comprising a fifth step of irradiating the catalyst material with irradiation light containing deep ultraviolet light having a wavelength of 380 nm or less between the second step and the third step. (Aspect 9) The production method according to any one of Aspects 1 to 8, wherein the fluorine-containing gas is one or more selected from hydrogen fluoride gas and fluorine gas. (Aspect 10) The production method according to any one of Aspects 1 to 9, wherein the object to be treated contains one or more selected from the group consisting of B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au. (Aspect 11) The production method according to Aspect 10, wherein the object to be treated further contains one or more selected from the group consisting of H, N, Cl, Br, and O. (Aspect 12) The object to be treated is SiO x , SiN y , SiCN, SiON, and SiC, and is one or more selected from the group consisting of SiC. The production method according to Aspect 11. (Aspect 13) The production method according to any one of Aspects 1 to 12, wherein the object to be treated is composed of a single member. (Aspect 14) The manufacturing method according to aspect 12, wherein the object to be processed is a quartz glass substrate, a boron-containing quartz glass substrate, a phosphorus-containing quartz glass substrate, a quartz crystal substrate, or a silicon substrate. (Aspect 15) The manufacturing method according to any one of aspects 1 to 14, wherein the object to be processed has a substrate and a film formed on the substrate, and at least the film contains an element having a fluoride boiling point of 550°C or lower. (Aspect 16) The manufacturing method according to aspect 15, wherein the film contains at least one selected from the group consisting of oxides, carbides, and nitrides of Si. (Aspect 17) A member having a concave structure, The concave structure includes a first concave structure and a second concave structure formed below the first concave structure and having a wider concave width than the first concave structure. Member. (Aspect 18) The first concave structure has a first width, The second concave structure has a second width wider than the first width, The concave structure is arranged such that two or more of the first concave structures and two or more of the second concave structures are alternately arranged in the depth direction of the member. The member according to aspect 17. (Aspect 19) A resin layer is further provided on the surface of the member, The lower part of the resin layer is formed so as to enter the first concave structure and the second concave structure. The member according to aspect 17 or 18.

Explanation of Signs

[0231] 1 Object to be processed 3 Catalyst material 5 First concave structure 6 Bottom surface 7 Side wall 7a First side wall portion 8a Coated area 8b Uncoated area 50 Concave portion 52 Opening 56 Bottom 57 Side wall 100 components 110 Object to be processed 112 Surface 114 Back side 130 Catalyst materials 131 patterns 140a Covered area 140b Uncovered area 150 First recessed structure 151 Second recessed structure 200 First component 202 Surface 204 Back side 250 recessed structure 252 Aperture 256 First recessed structure 257 Second recess structure 280 consecutive muscle 300 resin layer (a) HF molecule (b) Si atom (c) OH group (d) Si-F bond (e) -δ part (f) +δ part (g) H2O molecule

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 an element whose fluoride boiling point is 550°C or lower, A second step involves forming a catalyst material on a part of the surface of the object to be treated, A third step involves exposing the workpiece to a fluorine-containing gas at a first temperature of 80°C or higher to form a first recessed structure in the portion of the workpiece where the catalyst material is formed, The fourth step involves exposing the workpiece to a fluorine-containing gas at a second temperature higher than the first temperature, thereby forming a second recess structure having a wider recess width than the first recess structure. Manufacturing method.

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

3. The second temperature is the temperature at which the reaction-promoting substance volatilizes from the catalyst material. In the fourth step, the volatile reaction-promoting substance is used to accelerate etching with the fluorine-containing gas, thereby forming the second recessed structure by isotropically etching the workpiece. The manufacturing method according to claim 1 or 2.

4. The first temperature is 80°C or higher and 300°C or lower. The aforementioned second temperature is 300°C or higher. The manufacturing method according to claim 1 or 2.

5. The third and fourth steps are each performed alternately two or more times. The manufacturing method according to claim 1 or 2.

6. The method for producing the catalyst according to claim 1 or 2, wherein the catalyst material comprises an organic compound having a polar functional group.

7. The catalyst material is an organic compound having one or more polar functional groups selected from hydroxyl groups, aldehyde groups, carboxyl groups, amino groups, sulfo groups, thiol groups, amide bonds, carbonyl groups, nitro groups, cyano groups, ether bonds, and ester bonds; and An organic compound having one or more structures selected from the group consisting of a phosphorus-containing structure and a ring structure containing at least one of nitrogen and oxygen; a method for producing an organic compound according to claim 1 or 2, comprising one or more selected organic compounds.

8. The manufacturing method according to claim 6, further comprising a fifth step between the second step and the third step of irradiating the catalyst material with irradiation light including deep ultraviolet light with a wavelength of 380 nm or less.

9. The manufacturing method according to claim 1 or 2, wherein the fluorine-containing gas is one or more selected from hydrogen fluoride gas and fluorine gas.

10. The manufacturing method according to claim 1 or 2, wherein the material to be treated includes one or more selected from the group consisting of B, C, Si, P, S, Ti, V, Cr, Ga, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Sn, Sb, Te, I, Ta, W, Re, Os, Ir, Pt, and Au.

11. The manufacturing method according to claim 10, wherein the treated material further comprises one or more selected from the group consisting of H, N, Cl, Br, and O.

12. The treated object is SiO ｘ SiN ｙ The manufacturing method according to claim 10, wherein the material is one or more selected from the group consisting of SiCN, SiON, and SiC.

13. The manufacturing method according to claim 1 or 2, wherein the object to be processed is composed of a single component.

14. The manufacturing method according to claim 12, wherein the object to be treated is a quartz glass substrate, a boron-containing quartz glass substrate, a phosphorus-containing quartz glass substrate, a crystal substrate, or a silicon substrate.

15. The manufacturing method according to claim 1 or 2, wherein the object to be treated comprises a substrate and a film formed on the substrate, and at least the film contains an element whose fluoride boiling point is 550°C or lower.

16. The manufacturing method according to claim 16, wherein the film comprises one or more selected from the group consisting of oxides, carbides, and nitrides of Si.

17. A member having a recessed structure, The recessed structure comprises a first recessed structure and a second recessed structure formed below the first recessed structure, the second recessed structure having a wider recess than the first recessed structure. Components.

18. The first recessed structure has a first width, The second recess structure has a second width that is wider than the first width, The recessed structure is arranged such that two or more first recessed structures and two or more second recessed structures are arranged alternately in the depth direction of the member. The member according to claim 17.

19. A resin layer is further provided on the surface of the aforementioned member. The lower part of the resin layer is formed to fit into the first recessed structure and the second recessed structure. The member according to claim 17 or 18.

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