Capacitor

Abstract

The present invention provides a capacitor that addresses the degradation of withstand voltage characteristics. More specifically, the present invention provides a capacitor that reduces the degradation of withstand voltage characteristics caused by a volume change of an oxide film formed between a substrate and a dielectric layer. The present invention relates to a capacitor comprising: a metal substrate, a dielectric layer formed on the metal substrate, a conductive layer formed on the dielectric layer, an oxide layer formed between the metal substrate and the dielectric layer, and an oxygen barrier layer formed between the oxide layer and the dielectric layer, the oxide layer including a first oxidized region including a metal forming the metal substrate and a second oxidized region including atoms forming the oxygen barrier layer and a metal forming the metal substrate, the thickness of the first oxidized region being 3 nm or less and being 0% or more and 50% or less of the thickness of the second oxidized region.

Description

[Technical field]

[0001] The present disclosure relates to a capacitor and a method for manufacturing the same. [Background technology]

[0002] Conventionally, capacitors have been used in various electronic devices. The capacitors can be obtained by forming a dielectric film that exhibits capacitance on a substrate, and then forming a conductive film as an upper electrode on the dielectric film (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent application No. 2017-253367 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the formation of a dielectric film or the like on a substrate may be performed in an oxidizing atmosphere, an oxide film containing components derived from the substrate and / or the dielectric film may be formed between the substrate and the dielectric film. If a conductive film is formed on the dielectric film in a reducing atmosphere, the oxide film may be reduced and the volume of the oxide film may change. This volume change may form defects in the dielectric film on the oxide film, which may reduce the withstand voltage characteristics of the dielectric film.

[0005] An object of the present disclosure is to provide a capacitor that addresses the degradation of voltage resistance characteristics and a method for manufacturing the same. [Means for solving the problem]

[0006] In this disclosure, A metal substrate; a dielectric layer formed on the metal substrate; a conductive layer formed on the dielectric layer; an oxide layer formed between the metal substrate and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer, the oxide layer includes a first oxidation region including the metal forming the metal substrate and a second oxidation region including atoms forming the oxygen barrier layer and the metal forming the metal substrate; A capacitor is provided, wherein the thickness of the first oxide region is 3 nm or less, and is 0% to 50% of the thickness of the second oxide region.

[0007] In addition, in this disclosure, forming an oxygen barrier layer on a metal substrate; performing a reduction treatment on the metal base material on which the oxygen barrier layer is formed; forming a dielectric layer on the oxygen barrier layer; and forming a conductive layer on the dielectric layer.

[0008] The present disclosure also provides a semiconductor device comprising: a first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer; The oxide layer includes a first oxidized region including a metal forming the first electrode; a second oxidized region including atoms forming the oxygen barrier layer and a metal forming the first electrode; A capacitor component is provided, wherein the thickness of the first oxidized region is 3 nm or less, and is 0% to 50% of the thickness of the second oxidized region. Effect of the Invention

[0009] The capacitor and capacitor component of the present disclosure address the degradation of the withstand voltage characteristics. More specifically, the capacitor and capacitor component of the present disclosure reduce the degradation of the withstand voltage characteristics caused by the volume change of the oxide film formed between the substrate and the dielectric layer.

[0010] The method for manufacturing a capacitor according to the present disclosure can provide a capacitor that addresses the degradation of voltage endurance characteristics. More specifically, the method for manufacturing a capacitor according to the present disclosure can provide a capacitor in which the degradation of voltage endurance characteristics caused by a volume change of an oxide film formed between a substrate and a dielectric layer is reduced. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of a capacitor according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an enlarged portion of the oxide layer of the capacitor shown in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view of a conventional capacitor. [Figure 4] FIG. 4 is a diagram illustrating a method for manufacturing a capacitor according to the present disclosure. [Diagram 5] FIG. 5 is a schematic cross-sectional view of a capacitor produced as an example. [Figure 6] FIG. 6 is a schematic cross-sectional view of a capacitor fabricated as a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The capacitor of the present disclosure will be described in more detail below. Although the description will be made with reference to the drawings as necessary, various elements in the drawings are merely shown as schematic and illustrative examples for understanding the capacitor of the present disclosure, and the appearance and / or dimensional ratios may differ from the actual ones.

[0013] The various numerical ranges mentioned in this specification are intended to include the lower and upper limit values ​​themselves. In other words, for example, a numerical range of 1 to 10 can be interpreted as including the lower limit of "1" and the upper limit of "10."

[0014] <Capacitor> The capacitor of the present disclosure will be described with reference to Fig. 1 and Fig. 2. The capacitor 100 of the present disclosure includes a metal substrate 1, a dielectric layer 2 formed on the metal substrate 1, a conductive layer 3 formed on the dielectric layer 2, an oxide layer 4 formed between the metal substrate 1 and the dielectric layer 2, and an oxygen barrier layer 5 formed between the oxide layer 4 and the dielectric layer 2. The oxide layer 4 includes a first oxidized region 41 including a metal forming the metal substrate 1, and a second oxidized region 42 including atoms forming the oxygen barrier layer 5 and a metal forming the metal substrate 1. The thickness of the first oxidized region 41 is 3 nm or less, and is 0% or more and 50% or less of the thickness of the second oxidized region 42.

[0015] The capacitor 100 of the embodiment shown in FIG. 1 has a structure in which a metal substrate 1, a first oxidized region 41, a second oxidized region 42, an oxygen barrier layer 5, a dielectric layer 2, and a conductive layer 3 are laminated in this order.

[0016] A dielectric layer 2 is formed between the metal substrate 1 and the conductive layer 3, and when a voltage is applied between the metal substrate 1 and the conductive layer 3, an electric charge can be accumulated in the dielectric layer 2.

[0017] A conventional capacitor is shown in Fig. 3. In the past, when the volume of an oxide layer 4' formed on a metal substrate 1' of a capacitor 100' changes due to reduction or the like, the volume change may cause defects, such as cracks 6', in the dielectric layer 2' and / or conductive layer 3' on the oxide layer 4', which may reduce the voltage resistance of the dielectric layer 2'.

[0018] The capacitor 100 of the present disclosure is a capacitor 100 that addresses the degradation of voltage resistance characteristics by forming an oxygen barrier layer 5 between the oxide layer 4 and the dielectric layer 2, setting the thickness of the first oxidized region 41 constituting the oxide layer 4 to 3 nm or less, and setting the thickness of the first oxidized region 41 to 0% or more and 50% or less of the thickness of the second oxidized region 42. Specifically, by forming the oxygen barrier layer 5 between the oxide layer 4 and the dielectric layer 2 and setting the oxide layer 4 to the above thickness, the volume change of the oxide layer 4 is small even in a reducing atmosphere, and the formation of defects in the dielectric layer 2 can be suppressed.

[0019] Each component constituting the capacitor of the present disclosure will be described below.

[0020] [Metal base material] In the capacitor of the present disclosure, the metal substrate is not particularly limited as long as it is a metal having electrical conductivity. For example, the metal substrate may be at least one metal selected from the group consisting of Al, Ti, Ta, Nb, Ni, Cu, W, Mo, Ir, Ag, Rh, Co, and Fe. The metal substrate may be an alloy containing a plurality of the above metals.

[0021] In one embodiment, the metal forming the metal substrate may include a base metal. "Base metal" refers to metals other than noble metals and their alloys. Noble metals refer to Au, Ag, Pt, Pd, Rh, Ir, Ru, and Os. A metal substrate including a base metal can contribute to reducing the cost of a capacitor.

[0022] In one embodiment, the metal forming the metal substrate may contain at least one element selected from the group consisting of Cu, Al, Ta, Ti, Ni, Nb, W, Cr, and Fe. A metal substrate containing the above elements is easily formed as a porous metal substrate having the following porous structure. The porous metal substrate can easily increase the surface area of ​​the metal substrate, which makes it easier to improve the capacitance of the capacitor.

[0023] In one embodiment, the metal forming the metal base may contain at least one element selected from the group consisting of Cu, Ni, and Fe. The metal base containing the above element is easily reduced by the reduction treatment step described in detail below, so that a capacitor including the metal base containing the above element can easily achieve the effects of the present disclosure.

[0024] The thickness of the metal base is not particularly limited and can be appropriately selected depending on the purpose, and may be, for example, 10 μm to 1000 μm, preferably 30 μm to 300 μm. The thickness of the metal base means the length in the direction perpendicular to the mounting surface of the capacitor.

[0025] The metal base may be formed on a substrate, which may be a semiconductor substrate such as a Si (silicon) substrate or a GaAs (gallium arsenide) substrate, or an insulating substrate such as glass or alumina.

[0026] In order to improve the adhesion between the metal base material and the substrate, an adhesive layer may be formed between the metal base material and the substrate. The material of the adhesive layer may be Ti, Cr, or the like. The thickness of the adhesive layer may be, for example, 0.1 nm or more and 50 nm or less, preferably 1 nm or more and 20 nm or more, and more preferably 2 nm or more and 10 nm or less.

[0027] (Porous metal base material) In one embodiment, the metal substrate may be a porous metal substrate. A porous metal substrate has a porous structure and tends to have a large surface area, so that the capacitance of a capacitor using the porous metal substrate can be improved.

[0028] The porous metal substrate can be prepared by methods well known in the art, such as etching, sintering, dealloying, etc. Alternatively, a commercially available porous metal substrate may be used as the porous metal substrate.

[0029] In one embodiment, the porous metal substrate may have a high porosity portion and a low porosity portion. The "high porosity portion" refers to a portion of the porous metal substrate that has a higher porosity and a larger specific surface area than the low porosity portion, and constitutes a capacitance forming portion in the capacitor of the present disclosure. The "low porosity portion" refers to a portion of the porous metal substrate that has a lower porosity and a smaller specific surface area than the high porosity portion, and can contribute to increasing the mechanical strength of the capacitor of the present disclosure.

[0030] In the present disclosure, the term "porosity" refers to the proportion of voids in a porous metal substrate. The voids can be measured as follows. Note that the voids in a porous metal substrate may be ultimately filled with a dielectric layer, a conductive layer, and the like in the process of producing a capacitor, but the "voids" are calculated by not taking into account the substances filled in this way and regarding the filled areas as voids.

[0031] First, the conductive porous substrate is processed by FIB (Focused Ion Beam) microsampling to form a thin sample with a thickness of 60 nm or less. A predetermined area (3 μm × 3 μm) of this thin sample is measured by STEM (Scanning Transmission Electron Microscope)-EDS (Energy dispersive X-ray spectrometry) mapping analysis. Within the mapping measurement field of view, the area where the material constituting the conductive porous substrate exists is obtained. Then, the porosity can be calculated from the following equation. This measurement is performed at any three points, and the average of the measured values ​​is taken as the porosity. Porosity (%) = ((measured area - area where material constituting the substrate exists) / measured area) x 100

[0032] The porosity of the high porosity portion is preferably 20% or more, more preferably 30% or more, and even more preferably 35% or more, from the viewpoint of increasing the specific surface area and thus the capacitance of the capacitor, and is preferably 90% or less, and more preferably 80% or less, from the viewpoint of ensuring mechanical strength.

[0033] From the viewpoint of increasing mechanical strength, the porosity of the low porosity portion is preferably 60% or less than that of the high porosity portion, and more preferably 50% or less than that of the high porosity portion. For example, the porosity of the low porosity portion is preferably 20% or less, and more preferably 10% or less. The porosity of the low porosity portion may be 0%.

[0034] The width of the low porosity portion (the length in the mounting surface direction of the capacitor) is 3 μm or more and 1 mm or less, preferably 10 μm or more and 500 μm or less. By making the width of the low porosity portion 3 μm or more, preferably 10 μm or more, the mechanical strength of the capacitor can be increased. In addition, by making the width of the low porosity portion 1 mm or less, it is possible to secure a larger high porosity portion in a porous metal substrate of the same volume, and it is possible to obtain a high electrostatic capacitance. In order to increase the mechanical strength of the capacitor, it is preferable that the thickness of the low porosity portion (the length in the direction perpendicular to the mounting surface of the capacitor) is 50% or more of the thickness of the porous metal substrate, preferably the same as the thickness of the porous metal substrate (i.e., the entire thickness of the porous metal substrate).

[0035] The method for forming the low porosity portion is not particularly limited as long as the desired porosity can be obtained, but it is preferable to form it by pressing, for example, with a mold, etc. Pressing may be performed by sandwiching the porous metal substrate from the top and bottom surfaces, or may be performed from only one surface.

[0036] Alternatively, a low porosity portion may be formed by irradiating a pre-porous metal substrate with a CO2 laser, YAG laser, excimer laser, femtosecond laser, picosecond laser, nanosecond laser, or other all-solid-state pulsed laser to collapse the pores. All-solid-state pulsed lasers such as femtosecond laser, picosecond laser, and nanosecond laser are preferred because they allow more precise control of the shape and porosity of the low porosity portion.

[0037] The low porosity portion may be formed by filling the pores in the high porosity portion as described above, but may also be formed in the process of forming pores in a non-porous metal substrate. For example, when a porous metal foil is produced by etching, the portion where the low porosity portion is to be formed is masked and then etched, so that the masked portion becomes a non-etched layer and the low porosity portion is formed. In addition, when a low porosity portion is formed in the center of the foil, the etching process is stopped before the pores are formed to the center of the foil, so that the center becomes a non-etched layer and the low porosity portion is formed.

[0038] By combining the above pressing, laser processing, and formation of a non-etched layer, low porosity portions of various shapes can be formed.

[0039] [Dielectric Layer] In the capacitor of the present disclosure, the dielectric layer 2 is formed on a metal substrate 1. Note that "on the metal substrate" does not necessarily mean being in contact with the metal substrate, but means the space above the main surface of the metal substrate.

[0040] In one embodiment, the dielectric layer is not particularly limited as long as it is insulating, but may contain at least one element selected from the group consisting of Al, Si, Ti, Hf, Ta, Zr, W, Sr, Pb, and Ba.

[0041] The material for forming the dielectric layer is AlO x (e.g., Al2O3), SiO x (e.g., SiO2), AlTiO x , SiTiO x , HfO x , TaO x , ZrO x , HfSiO x , ZrSiO x , TiZrO x , TiZrWO x , TiO x , SrTiO x , PbTiO x , BaTiO x , BaSrTiO x , BaCaTiO x , SiAlO x Metal oxides such as AlN x , SiN x , AlScN x Metal nitrides such as AlO x N y , SiO x N y , HfSiO x N y , SiC x O y N z Metal oxynitrides such as AlOx , SiO x , SiO x N y , HfSiO x It is preferable that the above formula is a material structure, and does not limit the composition. That is, x, y, and z attached to O and N may be any value greater than 0, and the ratio of each element including metal elements is arbitrary. Also, the dielectric layer may be a layered compound consisting of multiple layers with different dielectric layers.

[0042] The thickness of the dielectric layer is not particularly limited, but is preferably 3 nm to 100 nm, more preferably 5 nm to 50 nm. By making the thickness of the dielectric layer 3 nm or more, it is possible to improve the insulation and reduce the leakage current. In addition, by making the thickness of the dielectric layer 100 nm or less, it is possible to obtain a larger electrostatic capacitance.

[0043] The dielectric layer is preferably formed by a gas phase method such as vacuum deposition, chemical vapor deposition (CVD), sputtering, atomic layer deposition (ALD), pulsed laser deposition (PLD), or a method using a supercritical fluid. The ALD method is more preferable from the viewpoint of forming a uniform and dense film. For example, the ALD method can form a more uniform and dense film even in the details of the pores in the high porosity portion.

[0044] [Conductive Layer] In the capacitor of the present disclosure, a conductive layer 3 is formed on a dielectric layer 2. The conductive layer 3 is a layer having electrical conductivity. A dielectric layer 2 exists between the conductive layer 3 and the metal base 1. When a voltage is applied between the metal base 1 and the conductive layer 3, an electric charge can be accumulated in the dielectric layer 2. When the metal base 1 is regarded as a mounting part, the metal base 1 corresponds to the bottom part of the capacitor, and therefore the conductive layer 3 can be regarded as an upper electrode.

[0045] The conductive layer is not particularly limited as long as it is conductive, and may contain at least one selected from the group consisting of Ni, Cu, W, Ti, Ag, Au, Pt, Zn, Sn, Pb, Fe, Cr, Mo, Ru, and Pd. The conductive layer may be an alloy layer, a nitride layer, or an oxynitride layer. The alloy layer may be, for example, CuNi, AuNi, or AuSn. The nitride layer and the oxynitride layer may be a metal nitride layer and a metal oxynitride, specifically, TiN, TiAlN, TiON, TiAlON, TaN, etc.

[0046] In one embodiment, the conductive layer may contain at least one element selected from the group consisting of Ti, W, Ni, Cu, Ag, Ru, and Pt. By containing the above elements, the conductive layer can have better conductivity.

[0047] In one embodiment, the conductive layer may be a nitride conductive layer. The nitride film is preferably TiN or TiON. By using a nitride conductive layer as the conductive layer, the conductive layer can have better electrical conductivity.

[0048] The thickness of the conductive layer is not particularly limited, but is preferably 3 nm or more, and more preferably 10 nm or more. By making the thickness of the conductive layer 3 nm or more, the resistance of the conductive layer itself can be reduced.

[0049] The conductive layer can be formed by ALD. The capacitance of the capacitor can be increased by using ALD. Alternatively, the conductive layer can be formed by a method such as chemical vapor deposition (CVD), plating, bias sputtering, Sol-Gel, conductive polymer filling, etc., which can cover the dielectric layer and substantially fill the pores of the porous metal substrate. Preferably, the conductive layer is formed on the dielectric layer by ALD, and a conductive material, preferably a material with a lower electrical resistance, is laminated thereon by another method to form the conductive layer. With such a configuration, a higher capacitance density and a lower ESR can be efficiently obtained.

[0050] In addition, if the conductive layer does not have sufficient conductivity as a capacitor electrode after formation of the conductive layer, an extraction electrode layer made of Al, Cu, Ni, etc. may be additionally formed on the surface of the conductive layer by a method such as sputtering, vapor deposition, plating, etc.

[0051] The thickness of the conductive layer is not particularly limited, but is preferably 3 nm or more, and more preferably 10 nm or more. By making the thickness of the conductive layer 3 nm or more, the resistance of the conductive layer itself can be reduced.

[0052] [Oxide layer] The oxide layer 4 is formed between the metal substrate 1 and the dielectric layer 2. The oxide layer 4 only needs to be located between the metal substrate 1 and the dielectric layer 2, and does not need to be in direct contact with both. The oxide layer is a layer containing an oxide. The oxide layer may be a layer containing only an oxide, or may contain a compound containing oxygen, such as an oxynitride or a hydroxide.

[0053] The oxide layer may be an oxide layer of a metal contained in the capacitor, for example, an oxide layer of a metal contained in a metal substrate.

[0054] In one embodiment, the thickness of the oxide layer may be 10 nm or less. From the viewpoint of further suppressing the deterioration of the voltage resistance characteristic, the thickness of the oxide layer may be 8 nm or less, preferably 6 nm or less, more preferably 4 nm or less, and further preferably 2 nm or less. When the oxide layer is composed of a plurality of layers, the thickness of the oxide layer means the total value of the thicknesses of those layers. For example, when the oxide layer is composed of a first oxidized region and a second oxidized region described later, the thickness of the oxide layer is the total value of the thickness of the first oxidized region and the thickness of the second oxidized region.

[0055] In one embodiment, the thickness of the oxide layer may be 10% or less of the thickness of the dielectric layer. By setting the thickness of the oxide layer in the above range, the formation of defects in the dielectric layer due to the volume change of the oxide layer can be further suppressed. From the viewpoint of further suppressing the deterioration of the withstand voltage characteristics, the thickness of the oxide layer may be 8% or less of the thickness of the dielectric layer, preferably 6% or less, more preferably 4% or less.

[0056] In the capacitor of the present disclosure, the oxide layer 4 includes a first oxidized region 41 and a second oxidized region 42 .

[0057] [First oxidation region] The first oxidized region 41 is a region containing a metal forming the metal substrate 1. Specifically, the first oxidized region is a layer containing an oxide of a metal forming the metal substrate. The first oxidized region is a region not containing a metal forming an oxygen barrier layer. The first oxidized region 41 is an oxidized region formed closer to the metal substrate 1 than the second oxidized region 42. The first oxidized region 41 is located between the metal substrate 1 and the second oxidized region 42.

[0058] The first oxidized region is formed by oxidation of the metal substrate, for example, the first oxidized region may be formed by natural oxidation of the metal substrate surface during the manufacture of the capacitor and / or during the formation of other layers, for example during the formation of an oxygen barrier layer.

[0059] The first oxidized region may change in volume when reduced. When the volume of the first oxidized region changes, stress due to the volume change is applied to the dielectric layer formed on the first oxidized region. For example, when the first oxidized region shrinks due to reduction, stress caused by the shrinkage may be applied to the dielectric layer. When the first volume change is large, the stress generated is likely to be large, and defects are likely to be formed in the dielectric layer. Therefore, it is preferable that the volume change of the first oxidized region is small.

[0060] In one embodiment, from the viewpoint of suppressing the formation of defects in the dielectric layer, the thickness of the first oxidized region is preferably 3 nm or less. By setting the thickness of the first oxidized region to 3 nm, defects in the dielectric layer are less likely to occur even if the volume of the first oxidized region changes. From the viewpoint of further suppressing the formation of defects in the dielectric layer, the thickness of the first oxidized region may be 2.5 nm or less, preferably 2 nm or less, more preferably 1.5 nm or less, even more preferably 1.0 nm or less, and particularly preferably 0.5 nm or less. In one aspect, the thickness of the first oxidized region may be 0 nm, i.e., below the detection limit, or may not exist.

[0061] In one embodiment, the thickness of the first oxidized region may be 0% or more and 50% or less of the thickness of the second oxidized region. By setting the thickness of the first oxidized region in the above range, defects in the dielectric layer are less likely to occur even if the volume of the first oxidized region changes. From the viewpoint of suppressing the formation of defects in the dielectric layer, the thickness of the first oxidized region may be 1% or more and 45% or less of the thickness of the second oxidized region, preferably 2% or more and 40% or less, more preferably 2% or more and 35% or less, even more preferably 3% or more and 30% or less, and particularly preferably 5% or more and 25% or less. Note that "the thickness of the first oxidized region is 0% of the thickness of the second oxidized region" means that the first oxidized region is substantially absent.

[0062] The thickness of the first oxide region can be measured by RBS analysis or STEM-EDX analysis.

[0063] (RBS analysis) When the thickness of the first oxidized region in the present disclosure is measured by RBS analysis, the RBS analysis can be performed using a high-resolution RBS surface analyzer HRBS500 (manufactured by Kobe Steel, Ltd.). In the RBS analysis, the first oxidized region and other components (e.g., dielectric layer) can be measured separately by the above-mentioned analyzer automatically or by analyzing the measurement region. The measurement conditions when using the above-mentioned analyzer are as follows. <Measurement conditions> Incident ions: 450keV He + Detected ions: Scattered He + ·Scattering angle: 70° ·Angle of incidence * :55° Specimen current: 10nA ·Irradiance: 12.5μC In-plane rotation: None Detector ** :MCP / PSD * Angle from normal to sample surface ** MCP=Micro Channel Plate, PSD=Position Sensitive Detector, SSD=Solid State Detector

[0064] (STEM-EDX analysis) When the thickness of the first oxidized region in the present disclosure is measured by STEM-EDX analysis, the STEM-EDX analysis can be performed using a JEM-ARM200F (manufactured by JEOL (JEOL Ltd.)) as an electron microscope (STEM) and a JED-2300T (manufactured by JEOL (JEOL Ltd.)) as an EDX. In the STEM-EDX analysis, the first oxidized region and other components (e.g., dielectric layer) can be measured separately by the above-mentioned analysis device automatically or by analyzing the measurement region.

[0065] The measurement conditions when using the above-mentioned analyzer are as follows. <Measurement conditions> Acceleration voltage: 200kV (The accelerating voltage may be changed to 100kV or 300kV depending on the condition of the sample.) Electron probe size (spatial resolution): 0.2 nm or less <Measurement procedure> Prepare an evaluation sample that is processed into a thin piece with a thickness of 30 nm or less. Using the aberration-corrected STEM-EDX analysis under the above measurement conditions, EDX analysis is performed on the cross section of the evaluation sample in an area with a position resolution of 0.2 nm or less to measure the thickness of the first oxidized region.

[0066] [Second oxidation region] The second oxidized region is a region containing atoms forming the oxygen barrier layer and a metal forming the metal substrate. Specifically, the second oxidized region is a layer containing an oxide of atoms forming the oxygen barrier layer, an oxide of a metal forming the metal substrate, and / or a complex oxide of atoms forming the oxygen barrier layer and a metal forming the metal substrate. The second oxidized region is an oxidized region that is relatively closer to the oxygen barrier layer than the first oxidized region.

[0067] The second oxidized region may change in volume when reduced, similarly to the first oxidized region. In this regard, it is preferable that the second oxidized region also undergoes a small volume change, similarly to the first oxidized region.

[0068] In one embodiment, from the viewpoint of suppressing the formation of defects in the dielectric layer, the thickness of the second oxidized region may be 10 nm or less, preferably 8 nm or less, more preferably 6 nm or less, even more preferably 4 nm or less, and particularly preferably 2 nm or less.

[0069] The thickness of the second oxide region can be measured by RBS analysis or STEM-EDX analysis. The thickness of the second oxide region can be measured by the same measurement method as the method for measuring the thickness of the first oxide region.

[0070] The thickness of the first oxidized region and the thickness of the second oxidized region can be measured, for example, by RBS analysis or STEM-EDX analysis of a cross section of a capacitor fabricated by forming a metal-insulator-metal (MIM) on a substrate. In measuring the thickness by RBS analysis, it is preferable to analyze the thickness of the first oxidized region and the thickness of the second oxidized region of a capacitor fabricated using a substrate with a substantially smooth surface. "Substantially smooth" means, for example, that the roughness of the substrate surface is about 1 nm or less. In addition, the thickness of the first oxidized region and the thickness of the second oxidized region of a capacitor fabricated using a substrate with a smooth surface can be measured by STEM-EDX analysis.

[0071] [Oxygen Barrier Layer] In the capacitor of the present disclosure, an oxygen barrier layer 5 is formed on the metal substrate 1. The oxygen barrier layer 5 is formed between the oxide layer 4 and the dielectric layer 2. The oxygen barrier layer 5 is a layer that is difficult for oxygen to permeate, and is a layer that can suppress the movement of oxygen from the dielectric layer 2 to the oxide layer 4 and from the oxide layer 4 to the dielectric layer 2.

[0072] In one embodiment, the atoms forming the oxygen barrier layer may include at least one of metal and metalloid atoms. The atoms forming the oxygen barrier layer may include both metal and metalloid atoms, or may include only one of metal and metalloid atoms. The oxygen barrier layer may be an alloy, an oxide, a nitride, an oxynitride, or a composite of a combination thereof, and the atoms forming the oxygen barrier layer may be atoms forming the alloy, oxide, nitride, oxynitride, or a composite of a combination thereof.

[0073] The metal atoms forming the oxygen barrier layer may be at least one selected from the group consisting of Ti, Al, Cr, Ga, W, Zr, Nb, Ta, Co, Cu, Zn, Sn, Ni, Ag, Fe, Mn, Ir, and Hf. From the viewpoint of making it easier to suppress the formation of an oxide layer, the metal atoms forming the oxygen barrier layer may be Al, Hf, and / or Ti.

[0074] The metalloid atom forming the oxygen barrier layer may be at least one selected from the group consisting of Si, Ge, As, Sc, B, and Sb. From the viewpoint of making it easier to suppress the formation of an oxide layer, the metalloid atom forming the oxygen barrier layer may be Si.

[0075] In one embodiment, the oxygen barrier layer may be an oxide, a nitride, an oxynitride, or a combination thereof. For example, the oxygen barrier layer may be an M 1 a M 2 b O x N y (M 1 and M.2 may each independently be formed from a material represented by Ti, Al, Cr, Ga, W, Zr, Nb, Ta, Co, Cu, Zn, Sn, Ni, Ag, Fe, Mn, Ir, Hf, Si, Ge, As, Sc, B, or Sb, a≧0, b≧0, x≧0, y≧0).

[0076] The oxygen barrier layer may include, for example, one or more selected from the group consisting of silicon oxide (e.g., SiO2), hafnium oxide (e.g., HfOx, e.g., HfO2), aluminum oxide (e.g., AlOx, e.g., Al2O3, AlO, or combinations thereof), titanium nitride (e.g., TiO2), and titanium oxynitride (e.g., TiON).

[0077] The oxygen barrier layer may be one layer or two or more layers. When two or more oxidation barrier layers are present, each layer may be composed of the same material or different materials.

[0078] In one embodiment, the oxygen barrier layer and the dielectric layer may be formed of the same material. By adopting such a configuration, the oxygen barrier layer or the dielectric layer can be made of the same material, which simplifies the switching of materials and makes it easier to achieve consistent quality of the capacitor.

[0079] In one embodiment, the oxygen barrier layer and the dielectric layer may be formed of different materials, so that the oxygen barrier layer is more resistant to oxygen permeation, and the dielectric layer is more excellent in withstand voltage characteristics.

[0080] In one embodiment, the thickness of the oxygen barrier layer may be 0.1 nm or more and 20 nm or less. From the viewpoint of further suppressing oxygen permeation, the thickness of the oxygen barrier layer may be 0.3 nm or more, preferably 0.5 nm or more, and more preferably 1.0 nm or more. The thickness of the oxygen barrier layer may be 15 nm or less, preferably 10 nm or less, further preferably 7 nm or less, more preferably 5 nm or less, and particularly preferably 3 nm or less. In addition, when there are two or more oxygen barrier layers, the thickness of the oxygen barrier layer is the sum of the thicknesses of the two layers.

[0081] In one embodiment, the thickness of the oxygen barrier layer may be 20% or less of the thickness of the dielectric layer. From the viewpoint of further preventing a decrease in voltage resistance characteristics, the thickness of the oxygen barrier layer may be 15% or less, preferably 10% or less of the thickness of the dielectric layer.

[0082] The oxygen barrier layer is preferably formed by a gas phase method such as a vacuum deposition method, a chemical vapor deposition (CVD) method, a sputtering method, an atomic layer deposition (ALD) method, a pulsed laser deposition (PLD) method, or a method using a supercritical fluid. The ALD method is more preferable from the viewpoint of forming a uniform and dense film.

[0083] <Capacitor parts> The present disclosure also provides a capacitor component.

[0084] The capacitor component of the present disclosure comprises: A first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer; The oxide layer includes a first oxidized region including a metal forming the first electrode; a second oxidized region including atoms forming the oxygen barrier layer and a metal forming the first electrode; The thickness of the first oxidized region is 3 nm or less, and is 0% to 50% of the thickness of the second oxidized region.

[0085] The capacitor component of the present disclosure is a component that constitutes the capacitor of the present disclosure. The capacitor component of the present disclosure can be made into the capacitor of the present disclosure by forming a conductive second electrode on the dielectric layer.

[0086] The first electrode corresponds to the metal substrate of the capacitor of the present disclosure and may have similar characteristics to the metal substrate, for example, the first electrode may be a porous metal substrate.

[0087] The capacitor components of the present disclosure have features for addressing the degradation of the voltage endurance characteristics of the capacitors of the present disclosure, and therefore the capacitor components of the present disclosure are less susceptible to the formation of defects in the dielectric layers, etc.

[0088] <Manufacturing method> The method for manufacturing the capacitor according to the present disclosure will now be described in detail.

[0089] The method for manufacturing a capacitor according to the present disclosure includes: forming an oxygen barrier layer on a metal substrate; performing a reduction treatment on the metal base material on which the oxygen barrier layer is formed; forming a dielectric layer on the oxygen barrier layer; and forming a conductive layer over the dielectric layer.

[0090] Taking FIG. 4 as an example, the method for manufacturing a capacitor according to the present disclosure will be described in more detail.

[0091] [Preparation of metal substrate] As shown in FIG. 4(a), a metal substrate 1 is prepared. The metal substrate 1 may be a metal material that is commonly used as a metal substrate for a capacitor. When a porous metal substrate is used as the metal substrate, the porous metal substrate can be prepared by a method well known in the art, such as etching, sintering, or dealloying. A commercially available porous metal substrate may be used as the porous metal substrate.

[0092] [Formation of oxygen barrier layer] Next, as shown in Fig. 4(b), an oxygen barrier layer 5 is formed on the metal substrate 1. When the oxygen barrier layer is formed, an oxide layer 4 including a first oxidized region 41 and a second oxidized region 42 may be formed on the metal substrate 1. By forming the oxygen barrier layer 5 on the metal substrate 1, in steps subsequent to the formation of the oxygen barrier layer 5, the oxide layer 4 is less likely to be formed on the metal substrate 1, and the thickness of the oxide layer 4 is less likely to increase.

[0093] The oxygen barrier layer 5 may be formed using a precursor of a material constituting the oxygen barrier layer 5. For example, SiO2 may be formed under an oxidizing agent atmosphere such as O3 using trisdimethylaminosilane (also referred to as 3DMAS) as a precursor. Alternatively, HfO2 may be formed under an oxidizing agent atmosphere such as O3 using tetrakis(ethylmethylamido)hafnium (TEMAHF) or tetrakis(dimethylamido)hafnium (TDMAHF). From the viewpoint of efficiently forming the oxygen barrier layer 5, the oxygen barrier layer 5 may be formed under heating conditions, for example, under heating conditions of 150°C or more and 400°C or less, preferably under heating conditions of 200°C or more and 300°C or less.

[0094] [Reduction Treatment] As shown in FIG. 4(c), after the oxygen barrier layer 5 is formed, a reduction treatment is performed. An oxide layer 4 including a first oxidized region 41 and a second oxidized region 42 may be formed on the metal substrate 1 during natural oxidation and / or formation of the oxygen barrier layer. The reduction treatment can reduce the oxide layer 4 formed on the metal substrate 1. Such reduction can reduce the thickness of the oxide layer 4. Specifically, the thickness of the first oxidized region 41 and the thickness of the second oxidized region 42, particularly the thickness 41 of the first oxidized region, can be reduced.

[0095] Since the oxygen barrier layer 5 is formed on the metal substrate 1, oxygen is prevented from reaching the metal substrate 1 and forming the oxide layer 4 in the steps subsequent to the reduction treatment. In other words, the thickness of the oxide layer 4 reduced by the reduction treatment can be maintained even after the steps subsequent to the reduction treatment, and the thickness is unlikely to increase.

[0096] The reduction treatment of the metal substrate 1 on which the oxygen barrier layer 5 is formed is carried out under a reducing atmosphere. The reducing atmosphere may be a condition under which the oxide layer 4 is reduced. For example, the reducing atmosphere may be a condition under which a reducing agent contacts the metal substrate 1 on which the oxygen barrier layer 5 is formed. As the reducing agent, formic acid, H2, ammonia, CO, or a hydrocarbon gas such as CH4 may be used. When the reducing agent contacts the metal substrate 1 on which the oxygen barrier layer 5 is formed, the contact may be in air or in air with a low oxygen concentration. From the viewpoint of efficient reduction treatment, the reduction treatment may be carried out in a vacuum or in an inert gas such as Ar or N2. In one example, the reduction atmosphere may be an N2-H2 atmosphere.

[0097] The reduction treatment may be performed at room temperature (for example, 5°C to 35°C) or at a temperature other than room temperature. From the viewpoint of efficient reduction treatment, the reduction treatment may be performed at a temperature higher than room temperature. When the reduction treatment is performed at a temperature higher than room temperature, it is preferable to perform the reduction treatment in an environment with a low oxygen concentration or an environment containing a reducing agent from the viewpoint of preventing the metal base material from being oxidized. In addition, when the reduction treatment is performed at a temperature higher than room temperature, reduction may be performed by heat without using the above-mentioned reducing agent. The temperature higher than room temperature may be a temperature generally used for heat treatment, or may be a temperature when annealing the metal base material. The reduction treatment may be performed, for example, in a vacuum furnace capable of heating under vacuum conditions, or an atmosphere furnace capable of heating under reducing and / or inert gas.

[0098] In one embodiment, the reduction treatment may be performed so that the thickness of the first oxidized region 41 is 3 nm or less. From the viewpoint of further suppressing the formation of defects in the dielectric layer, the reduction treatment may be performed so that the thickness of the first oxidized region 41 is 2.5 nm or less, preferably 2 nm or less, more preferably 1.5 nm or less, even more preferably 1.0 nm or less, and particularly preferably 0.5 nm or less.

[0099] [Formation of Dielectric Layer] After the reduction treatment, the dielectric layer 2 is formed as shown in Fig. 4(d). It may be formed by the ALD method, the CVD method, plating, bias sputtering, Sol-Gel, conductive polymer filling, etc. Also, these methods may be used in combination.

[0100] The dielectric layer 2 may be formed using a precursor of a material constituting the dielectric layer 2. For example, AlSiOx may be formed under an oxidizing agent atmosphere such as O3 using trimethylaluminum (also referred to as TMA) and trisdimethylaminosilane (also referred to as 3DMAS) as precursors. From the viewpoint of efficiently forming the dielectric layer 2, the dielectric layer 2 may be formed under heating conditions, for example, under heating conditions of 150°C or more and 400°C or less, and preferably under heating conditions of 200°C or more and 300°C or less.

[0101] From the viewpoint of forming a dielectric layer having better insulation properties and dielectric constant, the dielectric layer 2 may be formed in an oxidizing atmosphere. The oxidizing atmosphere may be one in which an oxidizing agent such as ozone or water is present. When forming the dielectric layer 2 (particularly when formed by atomic layer deposition), the metal base 1 is conventionally oxidized to form an oxide layer 4 on the metal base 1, but in the method for producing a capacitor of the present disclosure, the oxygen barrier layer 5 on the metal base 1 can suppress the formation of the oxide layer 4 on the metal base 1. Therefore, the oxidation in the formation of the dielectric layer can suppress an increase in the thickness of the oxide layer 4, the thickness of which has been reduced by the reduction treatment.

[0102] [Formation of Conductive Layer] After the dielectric layer 2 is formed, as shown in Fig. 4(e), a conductive layer 3 is formed on the dielectric layer 2. The conductive layer 3 may be formed by a method such as an ALD method, a CVD method, plating, bias sputtering, Sol-Gel, or conductive polymer filling. These methods may also be used in combination.

[0103] From the viewpoint of suppressing a change in volume due to reduction of the oxide layer 4, the conductive layer 3 may be formed by a method such as an ALD method or a CVD method.

[0104] From the viewpoint of forming a conductive layer with better conductivity, the conductive layer 3 may be formed under a reducing atmosphere. For example, when forming a thin film of a nitride as the conductive layer 3, a precursor of the nitride may be formed on the dielectric layer 2, and the nitride precursor on the dielectric layer 2 may be combined with a reducing agent to form a conductive layer of the nitride. As the reducing agent, one reducing agent selected from the group consisting of ammonia and hydrogen may be used.

[0105] When the conductive layer 3 is formed under a reducing atmosphere, for example when ammonia or hydrogen is used as a reducing agent, the reducing agent such as hydrogen may pass through the dielectric layer 2 and reduce the oxide layer 4 on the metal substrate 1. In conventional capacitors, the reduction of the oxide layer 4 may cause the oxide layer 4 to shrink, which may result in the formation of defects in the dielectric layer 2, etc. In the capacitor of the present disclosure, the thickness of the oxide layer 4, particularly the first oxidized region, is reduced by the formation of the oxygen barrier layer 5 and the reduction treatment, so that the volume change of the oxide layer 4 due to the reduction treatment is small. Therefore, in the manufacturing method of the capacitor 100 of the present disclosure, the formation of defects in the dielectric layer 2, etc. during the manufacturing process is suppressed.

[0106] When a porous metal substrate is used as the metal substrate, the conductive layer is preferably formed by the ALD method. From the viewpoint of forming a conductive layer even in the pores of the porous metal substrate, the raw material of the conductive layer is preferably a raw material with a high vapor pressure, and may be, for example, TDMAT (tetrakisdimethylaminotitanium) or TiCl4 (titanium tetrachloride).

[0107] Through the above steps, the capacitor of the present disclosure can be obtained.

[0108] Although the capacitor and the manufacturing method thereof according to the present disclosure have been described with respect to the capacitor of the above embodiment, the capacitor of the present disclosure is not limited thereto, and various modifications are possible. For example, in any step, a step of cutting the metal substrate to obtain a metal substrate of a desired size may be obtained. For example, a mask may be formed on a part of the metal substrate, then a conductive layer may be formed, and finally the mask may be removed to form an area in which the conductive layer is not formed. By going through the above steps, the size of the capacitor and the arrangement of various components can be adjusted. EXAMPLES

[0109] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these examples.

[0110] [Evaluation method] The characteristics of the capacitors produced in the following examples and comparative examples were evaluated using the following equipment. Probe system: SUMMIT12000 (Cascade Microtech) Semiconductor device parameter analyzer: B1500A (Agilent Technologies)

[0111] Example 1 A Si substrate was prepared. On the Si substrate, an adhesion layer made of Ti with a thickness of 5 nm and a lower electrode made of Ni with a thickness of 200 nm were formed in this order by sputtering.

[0112] The Si substrate with the adhesion layer and bottom electrode formed was placed in the vacuum chamber of the ALD device. Using 3DMAS as a precursor and O3 as an oxidant, an oxygen barrier layer made of SiO2 with a thickness of about 3 nm was formed on the bottom electrode at 250℃.

[0113] The Si substrate on which the oxygen barrier layer was formed was subjected to a reduction treatment.

[0114] The Si substrate after reduction treatment was placed again in the vacuum chamber of the ALD apparatus. Using TMA and 3DMAS as precursors and O3 as an oxidizing agent, a dielectric layer made of AlSiOx with a thickness of about 8 nm was formed on the oxygen barrier under conditions of 250°C. (Note that this formula simply expresses the structure of the dielectric and does not limit the composition. In other words, x added to O can be any value greater than 0, and the abundance ratio of each element, including metal elements, is omitted. Below, the abundance ratio of elements is omitted for formulas containing similar expressions.)

[0115] Next, the upper electrode was fabricated as follows. First, the Si substrate after the dielectric layer was formed was placed again in the vacuum chamber of the ALD apparatus. Using TiCl4 as a precursor and NH3 as a reducing agent, a TiN film with a thickness of about 10 nm was formed under the condition of 500°C. To form the extraction electrode of the upper electrode, a Ti film with a thickness of 5 nm and a Cu film with a thickness of 500 nm were formed on the TiN film. After that, a resist pattern of 1.3 mm square was formed by photolithography, and then Cu, Ti, and TiN were removed in this order by wet etching. After removing Cu, Ti, and TiN, the resist pattern was removed. As a result, an upper electrode containing Cu was formed on the dielectric layer.

[0116] Through the above process, a capacitor was obtained with an upper electrode (Cu), a dielectric (AlSiOx), an oxygen barrier layer (SiOx), and a lower electrode (Ni) (the components that make up each layer are listed in parentheses). The capacitance, BDV, and leakage current were evaluated as the capacitor characteristics. The results are shown in Table 1.

[0117] [Table 1]

[0118] Example 2 A capacitor was fabricated in the same manner as in Example 1, except that AlOx was used as the oxygen barrier layer. The formation of the oxygen barrier layer using AlOx was performed under the condition of 250°C, using TMA (trimethylaluminum) as a precursor and H2O as an oxidizing agent. The thickness of the oxygen barrier layer was about 5 nm. The capacitance, BDV, and leakage current were evaluated as the characteristics of the capacitor. The results are shown in Table 2.

[0119] [Table 2]

[0120] Example 3 A capacitor was fabricated in the same manner as in Example 1, except that HfOx was used as the oxygen barrier layer. The formation of the oxygen barrier layer using HfOx was performed under the condition of 250°C using TEMAHF (tetrakis(ethylmethylamido)hafnium) or TDMAHF (tetrakis(dimethylamido)hafnium) as a precursor and H2O as an oxidizing agent. The thickness of the oxygen barrier layer was about 7 nm. The capacitance, BDV, and leakage current were evaluated as the characteristics of the capacitor. The results are shown in Table 3.

[0121] [Table 3]

[0122] Example 4 Except for using a Ni porous body as the lower electrode, a capacitor was fabricated in the same manner as in Example 1. The Ni porous body was fabricated as follows.

[0123] The Ni conductive paste was applied to the Ni plate by screen printing. After application, the Ni plate was fired at approximately 500°C to form a Ni porous body bonded to the Ni plate. The dimensions of the Ni porous body were 0.5 mm x 0.5 mm. The thickness of the Ni porous body was approximately 20 um.

[0124] A capacitor using the Ni porous body obtained in Example 4 is shown in FIG. 5. As shown in FIG. 5, a Ni porous body 1 is provided on a Ni plate 8. A dielectric layer 2, an oxygen barrier layer 5, and a conductive layer 3 serving as an upper electrode cover the Ni porous body serving as a metal substrate 1 in this order. The Ni porous body is surrounded by an extraction electrode 7 made of Cu / Ti. The capacitance, BDV, and leakage current were evaluated as the characteristics of the capacitor. The results are shown in Table 4.

[0125] [Table 4]

[0126] Comparative Example 1 In Comparative Example 1, a capacitor was fabricated in the same manner as in Example 1, except that an oxygen barrier layer was not formed on the lower electrode, and a dielectric layer was formed on the lower electrode. The capacitance, BDV, and leakage current were evaluated as the characteristics of the capacitor. The results are shown in Table 5.

[0127] [Table 5]

[0128] Comparative Example 2 In Comparative Example 2, a capacitor was fabricated in the same manner as in Example 1, except that after forming the oxygen barrier layer on the lower electrode, a dielectric layer was formed on the oxygen barrier layer without performing a reduction treatment. The capacitance, BDV, and leakage current were evaluated as the capacitor characteristics. The results are shown in Table 6.

[0129] [Table 6]

[0130] Comparative Example 3 In Comparative Example 3, a capacitor was produced in the same manner as in Example 4, except that an oxygen barrier layer was not formed on the lower electrode, and a dielectric layer was formed on the lower electrode. A capacitor using the Ni porous body obtained in Comparative Example 3 is shown in FIG. 6. As shown in FIG. 6, a Ni porous body 1 is provided on a Ni plate 8. A dielectric layer 2 and a conductive layer 3, which is an upper electrode, cover the Ni porous body, which is a metal substrate 1, in this order. The Ni porous body is surrounded by an extraction electrode 7 made of Cu / Ti. The capacitance, BDV, and leakage current were evaluated as the characteristics of the capacitor.

[0131] As a result of the evaluation, the leakage current of the capacitor of Comparative Example 3 was very high, so that the capacitance, BDV, and leakage current could not be measured, and the capacitor was evaluated as having a problem in practical use.

[0132] [RBS analysis] As samples for RBS analysis, three samples were prepared by the following preparation method.

[0133] [Sample 1] A Si substrate was prepared. A 5 nm thick Ti layer (i.e., a layer corresponding to an adhesive layer) and a 200 nm thick Ni layer (i.e., a layer corresponding to a lower electrode) were formed in this order on the Si substrate by sputtering. The Si substrate having the formed layers was designated as Sample 1.

[0134] [Sample 2] Sample 1 was placed in the vacuum chamber of an ALD apparatus. Using 3DMAS as a precursor and O3 as an oxidizing agent, an oxygen barrier layer made of SiO2 and having a thickness of about 3 nm was formed on the layer made of Ni of Sample 1 under the condition of 250°C. The sample with the oxygen barrier layer formed was designated Sample 2.

[0135] [Sample 3] Sample 2 was subjected to a reduction treatment. The product obtained after the reduction treatment was designated as Sample 3.

[0136] (Measurement conditions) Incident ions: 450keV He + Detected ions: Scattered He + ·Scattering angle: 70° ·Angle of incidence * :55° Specimen current: 10nA ·Irradiance: 12.5μC In-plane rotation: None Detector ** :MCP / PSD * Angle from normal to sample surface ** MCP=Micro Channel Plate, PSD=Position Sensitive Detector, SSD=Solid State Detector

[0137] [RBS analysis results] The results of the RBS analysis of samples 1 to 3 are shown in Table 7.

[0138] [Table 7]

[0139] [Sample 1] A region composed only of Ni atoms was observed, which is believed to be the lower electrode.

[0140] A region composed of Ni atoms and O atoms was observed. This region is considered to be a layer formed by the oxidation of Ni in the lower electrode, and corresponds to the first oxidized region of the present disclosure. The thickness was 1.1 nm.

[0141] [Sample 2] A region composed only of Ni atoms was observed, which is believed to be the lower electrode.

[0142] A region composed of Si atoms and O atoms was confirmed. This region is thought to be a SiO2 layer that constitutes the oxygen barrier layer, and has a thickness of 3.7 nm.

[0143] A region composed of Ni atoms and O atoms was confirmed. This region is considered to be a layer formed by the oxidation of Ni in the lower electrode, and corresponds to the first oxidized region of the present disclosure. The thickness was 6.1 nm.

[0144] A region composed of Si atoms, Ni atoms, and O atoms was confirmed. This region is considered to be a layer derived from Ni atoms and O atoms of the first oxidized region and SiO2 of the oxygen barrier layer, and corresponds to the second oxidized region of the present disclosure. The thickness was 3 nm.

[0145] In sample 2, the thickness of the first oxidized region was 203% of the thickness of the second oxidized region.

[0146] [Sample 3] A region composed only of Ni atoms was observed, which is believed to be the lower electrode.

[0147] A region composed of Si atoms and O atoms was confirmed. This region is thought to be a SiO2 layer that constitutes the oxygen barrier layer, and has a thickness of 3.2 nm.

[0148] A region composed of Ni atoms and O atoms was confirmed. This region is considered to be a layer formed by the oxidation of Ni in the lower electrode, and corresponds to the first oxidized region of the present disclosure. The thickness was 0.8 nm.

[0149] A region composed of Si atoms, Ni atoms, and O atoms was confirmed. This region is considered to be a layer derived from Ni atoms and O atoms of the first oxidized region and SiO2 of the oxygen barrier layer, and corresponds to the second oxidized region of the present disclosure. The thickness was 1.8 nm.

[0150] In sample 3, the thickness of the first oxidized region was 44.4% of the thickness of the second oxidized region.

[0151] Comparing Sample 2 and Sample 3, the thickness of the first region relative to the thickness of the second oxidized region in Sample 3 was smaller than that in Sample 2. This is believed to be because the NiOx constituting the first oxidized region was reduced by the reduction treatment performed after the formation of the oxygen barrier layer.

[0152] Although the embodiments of the capacitor of the present disclosure have been described above, they are merely typical examples. Therefore, it will be easily understood by those skilled in the art that the capacitor of the present disclosure is not limited to these, and various embodiments are possible.

[0153] Aspects of the capacitor of the present disclosure are as follows. <1> A metal substrate; a dielectric layer formed on the metal substrate; a conductive layer formed on the dielectric layer; an oxide layer formed between the metal substrate and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer, the oxide layer includes a first oxidation region including the metal forming the metal substrate and a second oxidation region including atoms forming the oxygen barrier layer and the metal forming the metal substrate; A capacitor, wherein the thickness of the first oxide region is 3 nm or less, and is 0% or more and 50% or less of the thickness of the second oxide region. <2> The atoms forming the oxygen barrier layer include at least one of metal and semimetal atoms. <1> The capacitor according to claim 1 . <3> The atoms forming the oxygen barrier layer include at least one selected from the group consisting of Si, Hf, Al, and Ti. <1> or <2> The capacitor according to claim 1 . <4> the oxygen barrier layer is an oxide, a nitride, an oxynitride, or a combination thereof; <1> ~ <3> 2. The capacitor according to claim 1 . <5> the oxygen barrier layer and the dielectric layer are formed of the same material; <1> ~ <4> 2. The capacitor according to claim 1 . <6> The dielectric layer is formed of a material different from that of the oxygen barrier layer. <1> ~ <4> 2. The capacitor according to claim 1 . <7> The thickness of the oxygen barrier layer is 20% or less of the thickness of the dielectric layer. <1> ~ <6> 2. The capacitor according to claim 1 . <8> The thickness of the oxide layer is 10% or less of the thickness of the dielectric layer. <1> ~ <7> 2. The capacitor according to claim 1 . <9> The metal substrate is a porous metal substrate. <1> ~ <8> 2. The capacitor according to claim 1 . <10> The metal forming the metal substrate includes a base metal. <1> ~ <9> 2. The capacitor according to claim 1 . <11> The metal forming the metal base contains at least one element selected from the group consisting of Cu, Al, Ta, Ti, Ni, Nb, W, Cr, and Fe; <1> ~ <10> 2. The capacitor according to claim 1 . <12> The dielectric layer contains at least one element selected from the group consisting of Al, Si, Ti, Hf, Ta, Zr, Sr, Pb, and Ba. <1> ~ <11> 2. The capacitor according to claim 1 . <13> The conductive layer contains at least one element selected from the group consisting of Ti, W, Ni, Cu, Ag, Ru, and Pt. <1> ~ <12> 2. The capacitor according to claim 1 . <14> The conductive layer is a nitride conductive layer. <1> ~ <13> 2. The capacitor according to claim 1 . <15> The conductive layer is a layer formed in the presence of at least one reducing agent selected from the group consisting of ammonia and hydrogen. <1> ~ <14> 2. The capacitor according to claim 1 . <16> forming an oxygen barrier layer on a metal substrate; performing a reduction treatment on the metal base material on which the oxygen barrier layer is formed; forming a dielectric layer on the oxygen barrier layer; and forming a conductive layer on the dielectric layer. <17> A first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer; The oxide layer includes a first oxidized region including a metal forming the first electrode; a second oxidized region including atoms forming the oxygen barrier layer and a metal forming the first electrode; A capacitor component, wherein the thickness of the first oxidized region is 3 nm or less, and is 0% to 50% of the thickness of the second oxidized region. <18> The first electrode is a porous metal substrate. <17> The capacitor component according to claim 1 . [Industrial Applicability]

[0154] The capacitor of the present disclosure is highly stable and reliable and is therefore suitable for use in a variety of electronic devices. [Explanation of symbols]

[0155] 100,100' Capacitor 1, 1' Metal base material 2, 2' Dielectric layer 3, 3' Conductive layer 4, 4' oxide layer 41 First Oxidation Region 42 Second Oxidation Region 5. Oxygen Barrier Layer 6' Crack 7 Extraction electrode 8. Ni plate

Claims

1. A metal substrate; a dielectric layer formed on the metal substrate; a conductive layer formed on the dielectric layer; an oxide layer formed between the metal substrate and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer, the oxide layer includes a first oxidized region that includes the metal that forms the metal substrate, and a second oxidized region that includes atoms that form the oxygen barrier layer and the metal that forms the metal substrate; A capacitor, wherein the thickness of the first oxide region is 3 nm or less, and is 0% or more and 50% or less of the thickness of the second oxide region.

2. The capacitor of claim 1 , wherein the atoms forming the oxygen barrier layer include at least one of metal and semi-metal atoms.

3. 3. The capacitor according to claim 1, wherein the atoms forming the oxygen barrier layer include at least one selected from the group consisting of Si, Hf, Al, and Ti.

4. The capacitor of claim 1 , wherein the oxygen barrier layer is an oxide, a nitride, an oxynitride, or a combination thereof.

5. The capacitor of claim 1 , wherein the oxygen barrier layer and the dielectric layer are formed of the same material.

6. The capacitor of claim 1 , wherein the dielectric layer is formed of a different material than the oxygen barrier layer.

7. The capacitor of claim 1 , wherein the thickness of the oxygen barrier layer is 20% or less than the thickness of the dielectric layer.

8. The capacitor of claim 1 , wherein the thickness of the oxide layer is less than or equal to 10% of the thickness of the dielectric layer.

9. The capacitor of claim 1 , wherein the metal substrate is a porous metal substrate.

10. The capacitor of claim 1 , wherein the metal forming the metal substrate comprises a base metal.

11. 2. The capacitor of claim 1, wherein the metal forming the metal substrate comprises at least one element selected from the group consisting of Cu, Al, Ta, Ti, Ni, Nb, W, Cr, and Fe.

12. 2. The capacitor of claim 1, wherein the dielectric layer comprises at least one element selected from the group consisting of Al, Si, Ti, Hf, Ta, Zr, Sr, Pb, and Ba.

13. The capacitor of claim 1 , wherein the conductive layer comprises at least one element selected from the group consisting of Ti, W, Ni, Cu, Ag, Ru, and Pt.

14. 2. The capacitor of claim 1, wherein the conductive layer is a nitride conductive layer.

15. 2. The capacitor according to claim 1, wherein the conductive layer is a layer formed in the presence of at least one reducing agent selected from the group consisting of ammonia and hydrogen.

16. The metal substrate is nickel; The capacitor of claim 1 , wherein the oxygen barrier layer comprises at least one selected from the group consisting of silicon oxide, aluminum oxide, and hafnium oxide.

17. A first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; an oxygen barrier layer formed between the oxide layer and the dielectric layer; The oxide layer includes a first oxidized region including a metal forming the first electrode; a second oxidized region including atoms forming the oxygen barrier layer and a metal forming the first electrode; A capacitor component, wherein the thickness of the first oxidized region is 3 nm or less and is 0% to 50% of the thickness of the second oxidized region.

18. The capacitor component of claim 17 , wherein the first electrode is a porous metal substrate.

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