Capacitor and method for manufacturing same

Abstract

The present invention provides a capacitor in which a deterioration in withstand voltage characteristics is addressed. The present invention specifically provides a capacitor in which a deterioration in the withstand voltage characteristics due to a volume change of an oxide film that is formed between a base material and a dielectric layer is reduced. The present invention relates to a capacitor comprising: a metal base material; a dielectric layer formed on the metal base material; a conductive layer formed on the dielectric layer; an oxide layer formed between the metal base material and the dielectric layer; and an oxygen barrier layer formed between the oxide layer and the dielectric layer. The oxide layer comprises: a first oxidation region containing a metal which forms the metal base material; and a second oxidation region containing an atom which forms the oxygen barrier layer and a metal which forms the metal base material. The thickness of the first oxidation region is 3 nm or less, and is equal to 0% to 50% of the thickness of the second oxidation region.

Description

Capacitor and manufacturing method thereof

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

[0002] Conventionally, capacitors have been used in various electronic devices. Such 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).

[0003] Patent application No. 2017-253367

[0004] Since a dielectric film or the like is sometimes formed on a substrate 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, causing a change in volume of the oxide film. This volume change may cause defects in the dielectric film on the oxide film, resulting in a decrease in the withstand voltage characteristics of the dielectric film.

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

[0006] The present disclosure provides 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, wherein the oxide layer comprises a first oxidized region containing a metal forming the metal substrate and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the metal substrate, and 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.

[0007] The present disclosure also provides a method for manufacturing a capacitor, including: forming an oxygen barrier layer on a metal substrate; subjecting the metal substrate on which the oxygen barrier layer has been formed to a reduction treatment; 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 capacitor component comprising: a first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; and an oxygen barrier layer formed between the oxide layer and the dielectric layer, wherein the oxide layer comprises a first oxidized region containing a metal forming the first electrode; and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the first electrode, and 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.

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

[0010] The capacitor manufacturing method of the present disclosure can provide a capacitor that addresses the degradation of withstand voltage characteristics. More specifically, the capacitor manufacturing method of the present disclosure can provide a capacitor in which the degradation of withstand voltage characteristics caused by volume changes of the oxide film formed between the substrate and the dielectric layer is reduced.

[0011] FIG. 1 is a schematic cross-sectional view of a capacitor according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view in which an oxide layer of the capacitor in FIG. 1 is partially enlarged. FIG. 3 is a schematic cross-sectional view of a conventional capacitor. FIG. 4 is a diagram illustrating a method for manufacturing a capacitor according to the present disclosure. FIG. 5 is a schematic cross-sectional view of a capacitor fabricated as an example. FIG. 6 is a schematic cross-sectional view of a capacitor fabricated as a comparative example.

[0012] The capacitor of the present disclosure will be described in more detail below. While the description will be made with reference to drawings as necessary, various elements in the drawings are merely shown schematically and illustratively to facilitate understanding of the capacitor of the present disclosure, and the appearance and / or dimensional ratios may differ from those of the actual capacitor.

[0013] The various numerical ranges mentioned in this specification are intended to include the lower and upper limits themselves. That is, 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> A capacitor according to the present disclosure will be described with reference to Figures 1 and 2. A capacitor 100 according to 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 containing a metal forming the metal substrate 1, and a second oxidized region 42 containing atoms forming the oxygen barrier layer 5 and the metal forming the metal substrate 1. The thickness of the first oxidized region 41 is 3 nm or less and is 0% to 50% 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 a conventional capacitor 100', when the volume of an oxide layer 4' formed on a metal substrate 1' changes due to reduction or the like, the volume change may cause defects, such as cracks 6', in a dielectric layer 2' and / or a conductive layer 3' on the oxide layer 4', which may result in a decrease in the withstand voltage characteristics of the dielectric layer 2'.

[0018] The capacitor 100 of the present disclosure is configured to address 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% to 50% 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 Substrate] In the capacitor of the present disclosure, the metal substrate is not particularly limited as long as it is a conductive metal. 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 also be an alloy containing two or more 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 alloys thereof. Noble metals include Au, Ag, Pt, Pd, Rh, Ir, Ru, and Os. A metal substrate including a base metal can contribute to reducing the cost of the 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 can be easily formed into a porous metal substrate having the following porous structure. A porous metal substrate can easily increase the surface area of ​​the metal substrate, thereby easily improving 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. Metal bases containing the above elements are easily reduced by the reduction treatment step described in detail below, and therefore capacitors including metal bases containing the above elements are likely to achieve the effects of the present disclosure.

[0024] The thickness of the metal substrate 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 substrate means the length in the direction perpendicular to the mounting surface of the capacitor.

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

[0026] In order to improve the adhesion between the metal substrate and the substrate, an adhesion layer may be formed between the metal substrate and the substrate. Ti, Cr, or the like may be used as a material for the adhesion layer. The thickness of the adhesion 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 Substrate) 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, which can further improve the capacitance of a capacitor using the porous metal substrate.

[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.

[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, "porosity" refers to the proportion of voids in a porous metal substrate. Porosity can be measured as follows. Note that, although the voids in a porous metal substrate may ultimately be filled with a dielectric layer, a conductive layer, or the like in the process of manufacturing a capacitor, the "porosity" is calculated by regarding the filled areas as voids, without taking into account the materials filled in this way.

[0031] First, the conductive porous substrate is processed into a thin sample having a thickness of 60 nm or less using a FIB (Focused Ion Beam) microsampling method. A predetermined area (3 μm × 3 μm) of this thin sample is measured using STEM (Scanning Transmission Electron Microscope)-EDS (Energy Dispersive X-ray Spectrometry) mapping analysis. The area where the material constituting the conductive porous substrate exists within the mapping measurement field is determined. The porosity can then be calculated using the following equation. This measurement is performed at any three locations, and the average value of the measured values ​​is taken as the porosity. Porosity (%) = ((Measured Area - Area Where the Material Constituting the Substrate Exists) / Measured Area) × 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 enhancing mechanical strength, the porosity of the low-porosity portion is preferably 60% or less of the porosity of the high-porosity portion, and more preferably 50% or less of the porosity 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. Furthermore, 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. Furthermore, by making the width of the low-porosity portion 1 mm or less, it is possible to ensure a larger high-porosity portion in a porous metal substrate of the same volume, making it 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, for example, pressing using a mold, etc. The pressing may be performed by sandwiching the porous metal substrate from the top and bottom surfaces, or from only one surface.

[0036] Alternatively, a porous metal substrate that has been previously made porous may be treated with CO ２ The low-porosity portion may be formed by collapsing the pores by irradiation with an all-solid-state pulsed laser such as a laser, a YAG laser, an excimer laser, or a femtosecond laser, a picosecond laser, or a nanosecond laser. All-solid-state pulsed lasers such as a femtosecond laser, a picosecond laser, or a nanosecond laser are preferred because they allow for 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 it can also be formed during the process of forming pores in a non-porous metal substrate. For example, when producing a porous metal foil by etching, the area where the low-porosity portion is to be formed is masked before etching, and the masked area becomes a non-etched layer, forming the low-porosity portion. Furthermore, when forming a low-porosity portion in the center of the foil, the etching process is stopped before pores are formed to the center of the foil, and the center becomes a non-etched layer, forming the low-porosity portion.

[0038] By combining the above pressing, laser processing, and formation of a non-etching 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 the 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 (For example, Al ２ O ３ ), SiO ｘ (e.g., SiO ２ ), 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 and AlO ｘ , SiO ｘ , SiOｘ N ｙ , HfSiO ｘ It is preferable that the above formula simply expresses the structure of the material 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 abundance ratio of each element including the metal element is arbitrary. In addition, the compound 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 insulation properties and reduce leakage current. Furthermore, 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 preferred 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 fine pores of a 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 substrate 1. When a voltage is applied between the metal substrate 1 and the conductive layer 3, a charge can be stored in the dielectric layer 2. When the metal substrate 1 is considered as a mounting part, the metal substrate 1 corresponds to the bottom part of the capacitor, and therefore the conductive layer 3 can be considered 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 layer, 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 any of 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 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 an ALD method. The use of an ALD method can increase the capacitance of the capacitor. Alternatively, the conductive layer can be formed by a method such as chemical vapor deposition (CVD), plating, bias sputtering, Sol-Gel, or conductive polymer filling, which can coat the dielectric layer and substantially fill the pores of the porous metal substrate. Preferably, the conductive layer is formed on the dielectric layer by an ALD method, and then a conductive material, preferably a material with lower electrical resistance, is deposited thereon by another method to form the conductive layer. This configuration can efficiently achieve higher capacitance density and lower ESR.

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

[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 is only required 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 also contain a compound containing oxygen, such as an oxynitride or 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 a decrease in voltage resistance characteristics, the thickness of the oxide layer may be 8 nm or less, preferably 6 nm or less, more preferably 4 nm or less, and even more preferably 2 nm or less. When the oxide layer is composed of multiple layers, the thickness of the oxide layer refers to the total thickness of those layers. For example, when the oxide layer is composed of a first oxidized region and a second oxidized region described below, the thickness of the oxide layer is the total thickness of the first oxidized region and 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 within the above range, the formation of defects in the dielectric layer due to volume changes of the oxide layer can be further suppressed. From the viewpoint of further suppressing a decrease in 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, and 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 Oxidized Region] The first oxidized region 41 is a region containing a metal that forms the metal substrate 1. Specifically, the first oxidized region is a layer containing an oxide of the metal that forms the metal substrate. The first oxidized region is a region that does not contain a metal that forms an oxygen barrier layer. The first oxidized region 41 is an oxidized region that is 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 capacitor fabrication and / or during the formation of other layers, such as the formation of an oxygen barrier layer.

[0059] The volume of the first oxidized region may change 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 be nonexistent.

[0061] In one embodiment, the thickness of the first oxidized region may be 0% to 50% of the thickness of the second oxidized region. By setting the thickness of the first oxidized region within 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% to 45% of the thickness of the second oxidized region, preferably 2% to 40%, more preferably 2% to 35%, even more preferably 3% to 30%, and particularly preferably 5% to 25%. 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 oxidized 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 using the analyzer automatically or by analyzing the measurement region. The measurement conditions when using the analyzer are as follows: <Measurement Conditions> Incident ions: 450 keV He ＋ Detected ions: scattered He ＋ ・Scattering angle: 70° ・Incidence angle ＊ : 55° Specimen current: 10 nA Irradiation dose: 12.5 μC In-plane rotation: None Detector ＊＊ : MCP / PSD ＊ Angle from the normal to the 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 Ltd.) as an electron microscope (STEM) and a JED-2300T (manufactured by JEOL Ltd.) as an EDX. In the STEM-EDX analysis, the first oxidized region and other components (e.g., a dielectric layer) can be measured separately, either automatically by the above-mentioned analytical device or by analyzing the measurement region.

[0065] The measurement conditions when using the above analysis device are as follows. <Measurement conditions> - Acceleration voltage: 200 kV (The acceleration voltage may be changed to 100 kV or 300 kV depending on the state of the sample) - Electron probe size (spatial resolution): 0.2 nm or less <Measurement procedure> An evaluation sample processed into a thin piece with a thickness of 30 nm or less is prepared. Using aberration-corrected STEM-EDX analysis under the above measurement conditions, the cross section of the evaluation sample is subjected to EDX analysis in a region with a position resolution of 0.2 nm or less, and the thickness of the first oxidized region is measured.

[0066] [Second Oxidized 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 the atoms forming the oxygen barrier layer, an oxide of the metal forming the metal substrate, and / or a complex oxide of the atoms forming the oxygen barrier layer and the 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, like the first oxidized region, may change in volume when reduced, and in this respect, like the first oxidized region, it is preferable that the volume change of the second oxidized region is small.

[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 oxidized region can be measured by RBS analysis or STEM-EDX analysis using the same method as that for measuring the thickness of the first oxidized 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. When measuring thickness using 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 approximately 1 nm or less. Note that STEM-EDX analysis can measure the thickness of the first oxidized region and the second oxidized region of a capacitor fabricated using a porous metal substrate, as well as a capacitor fabricated using a substrate with a smooth surface.

[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 metal or metalloid atoms. The oxygen barrier layer may be an alloy, an oxide, a nitride, an oxynitride, or a composite consisting of a combination thereof, and the atoms forming the oxygen barrier layer may be atoms forming the alloy, oxide, nitride, oxynitride, or a composite consisting 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 atoms 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 atoms 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 the formula: 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 be made of, for example, silicon oxide (e.g., SiO ２ ), hafnium oxide (e.g., HfOx, e.g., HfO ２ ), aluminum oxide (e.g., AlOx, e.g., Al ２ O ３ , AlO, or combinations thereof), titanium nitride (e.g., TiO ２ ), and titanium oxynitride (for example, 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 made 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, which allows the oxygen barrier layer and the dielectric layer to be made of the same material, simplifying the process of switching materials and making it easier to achieve consistent capacitor quality.

[0079] In one embodiment, the oxygen barrier layer and the dielectric layer may be formed of different materials, and by adopting such a configuration, the oxygen barrier layer can be made more resistant to oxygen permeation, and the dielectric layer can be made a dielectric layer with better voltage resistance 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, even more preferably 7 nm or less, more preferably 5 nm or less, and particularly preferably 3 nm or less. When two or more oxygen barrier layers are present, 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 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 preferred from the viewpoint of forming a uniform and dense film.

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

[0084] The capacitor component of the present disclosure includes a first electrode, a dielectric layer formed on the first electrode, an oxide layer formed between the first electrode and the dielectric layer, and an oxygen barrier layer formed between the oxide layer and the dielectric layer, wherein the oxide layer includes a first oxidized region containing a metal forming the first electrode, and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the first electrode, and 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 resistance characteristics of the capacitors of the present disclosure, and therefore the capacitor components of the present disclosure are suppressed from forming defects in the dielectric layers, etc.

[0088] <Manufacturing Method> A method for manufacturing the capacitor of 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, reducing the metal substrate on which the oxygen barrier layer has been formed, forming a dielectric layer on the oxygen barrier layer, and forming a conductive layer on the dielectric layer.

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

[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 commonly used as a metal substrate for capacitors. 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] 4(b), an oxygen barrier layer 5 is formed on the metal substrate 1. During the formation of the oxygen barrier layer, 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, trisdimethylaminosilane (also referred to as 3DMAS) or the like may be used as the precursor to form the oxygen barrier layer 5. ３ SiO ２ Alternatively, tetrakis(ethylmethylamido)hafnium (TEMAHF) or tetrakis(dimethylamido)hafnium (TDMAHF) can be used to form O ３ HfO ２ From the viewpoint of efficiently forming the oxygen barrier layer 5, the oxygen barrier layer 5 may be formed under heating conditions, for example, at a temperature of 150° C. or higher and 400° C. or lower, preferably at a temperature of 200° C. or higher and 300° C. or lower.

[0094] [Reduction Treatment] As shown in FIG. 4( c), after the formation of the oxygen barrier layer 5, 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 by natural oxidation and / or during the 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 42 of the second oxidized region, 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 in 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 comes into contact with the metal substrate 1 on which the oxygen barrier layer 5 is formed. Examples of the reducing agent include formic acid, H ２ , ammonia, CO, or CH ４ Alternatively, a hydrocarbon gas such as N may be used. When the reducing agent is brought into contact with 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, the reduction may be carried out in a vacuum or in an inert gas such as Ar or N. In one example, the reduction atmosphere is N ２ -H ２ It could also be the atmosphere.

[0097] The reduction treatment may be carried out at room temperature (e.g., 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 carried out at a temperature higher than room temperature. When the reduction treatment is carried out at a temperature higher than room temperature, it is preferable to carry out the reduction treatment in an environment with a low oxygen concentration or an environment containing a reducing agent from the viewpoint of preventing oxidation of the metal substrate. Furthermore, when the reduction treatment is carried out at a temperature higher than room temperature, reduction may be carried out by heat without using the reducing agent. The temperature higher than room temperature may be a temperature generally used for heat treatment, or may be a temperature used for annealing a metal substrate. The reduction treatment may be carried out, 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 becomes 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 becomes 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 ALD, CVD, plating, bias sputtering, Sol-Gel, conductive polymer filling, or other methods. These methods may also be used in combination.

[0100] The dielectric layer 2 may be formed using a precursor of the material that constitutes the dielectric layer 2. For example, trimethylaluminum (also referred to as TMA) and trisdimethylaminosilane (also referred to as 3DMAS) may be used as the precursor to form O ３ From the viewpoint of efficiently forming the dielectric layer 2, the dielectric layer 2 may be formed under heating conditions, for example, at a temperature of 150° C. or higher and 400° C. or lower, preferably at a temperature of 200° C. or higher and 300° C. or lower.

[0101] From the viewpoint of forming a dielectric layer with better insulating properties and dielectric constant, the dielectric layer 2 may be formed in an oxidizing atmosphere. The oxidizing atmosphere may be formed in the presence of an oxidizing agent such as ozone or water. Conventionally, when forming the dielectric layer 2 (particularly when formed by atomic layer deposition), the metal substrate 1 is oxidized to form an oxide layer 4 on the metal substrate 1. However, in the capacitor manufacturing method of the present disclosure, the oxygen barrier layer 5 on the metal substrate 1 can suppress the formation of the oxide layer 4 on the metal substrate 1. Therefore, the oxidation during 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, the conductive layer 3 is formed on the dielectric layer 2 as shown in Fig. 4(e). The conductive layer 3 may be formed by ALD, CVD, plating, bias sputtering, Sol-Gel, conductive polymer filling, or other methods. 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, conductive layer 3 may be formed in a reducing atmosphere. For example, when forming a thin film of nitride as conductive layer 3, a precursor of the nitride may be formed on dielectric layer 2, and the nitride precursor on dielectric layer 2 may be combined with a reducing agent to form a nitride conductive layer. 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 in a reducing atmosphere, for example, when ammonia or hydrogen is used as a reducing agent, the reducing agent such as hydrogen can pass through the dielectric layer 2 and reduce the oxide layer 4 on the metal substrate 1. In conventional capacitors, such reduction of the oxide layer 4 can cause the oxide layer 4 to shrink, potentially forming 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, thereby reducing the volume change of the oxide layer 4 due to the reduction treatment. Therefore, the manufacturing method of the capacitor 100 of the present disclosure suppresses the formation of defects in the dielectric layer 2, etc. during the manufacturing process.

[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 for the conductive layer is preferably a raw material with a high vapor pressure, such as TDMAT (tetrakisdimethylaminotitanium) or TiCl ４ (titanium tetrachloride).

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

[0108] Although the capacitor and manufacturing method of the present disclosure have been described in relation to the capacitor of the above embodiment, the capacitor of the present disclosure is not limited thereto and various modifications are possible. For example, a step of cutting the metal substrate to obtain a metal substrate of a desired size may be added in any step. For example, a mask may be formed on a portion of the metal substrate, followed by forming a conductive layer, and finally removing the mask to form an area where the conductive layer is not formed. By undergoing the above steps, the size of the capacitor and the arrangement of various components can be adjusted.

[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 (manufactured by Cascade Microtech) Semiconductor device parameter analyzer: B1500A (manufactured by Agilent Technologies)

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

[0112] The Si substrate on which the adhesion layer and the lower electrode were formed was placed in the vacuum chamber of the ALD apparatus. ３ At 250°C, SiO with a thickness of about 3 nm was formed. ２ An oxygen barrier layer composed of was formed on the lower electrode.

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

[0114] The Si substrate after the reduction treatment was placed again in the vacuum chamber of the ALD apparatus. TMA and 3DMAS were used as precursors, and O was used as an oxidant. ３ A dielectric layer of AlSiOx having a thickness of approximately 8 nm was formed on the oxygen barrier at 250° C. (Note that this formula simply expresses the structure of the dielectric and does not limit the composition. In other words, the x attached to O may be any value greater than 0, and the abundance ratio of each element, including metal elements, is omitted. In the following, the abundance ratio of elements is also omitted for formulas containing similar expressions.)

[0115] Next, the upper electrode was fabricated as follows: First, the Si substrate on which the dielectric layer had been formed was placed again in the vacuum chamber of the ALD apparatus. ４ , NH as a reducing agent ３A TiN film approximately 10 nm thick was formed at 500°C using a SiO 2 film. To form an extraction electrode for the upper electrode, a 5 nm thick Ti film and a 500 nm thick Cu film were formed on the TiN film. A 1.3 mm square resist pattern was then formed by photolithography, and the Cu, Ti, and TiN were then removed in this order by wet etching. After the Cu, Ti, and TiN were removed, the resist pattern was removed. As a result, a Cu-containing upper electrode was formed on the dielectric layer.

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

[0117]

[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 oxygen barrier layer using AlOx was formed using TMA (trimethylaluminum) as a precursor and H ２ The test was performed using O at 250°C. The thickness of the oxygen barrier layer was approximately 5 nm. The capacitor characteristics were evaluated in terms of capacitance, BDV, and leakage current. The results are shown in Table 2.

[0119]

[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 carried out using TEMAHF (tetrakis(ethylmethylamido)hafnium) or TDMAHF (tetrakis(dimethylamido)hafnium) as a precursor and H ２ The test was performed using O at 250°C. The thickness of the oxygen barrier layer was approximately 7 nm. The capacitance, BDV, and leakage current were evaluated as the capacitor characteristics. The results are shown in Table 3.

[0121]

[0122] Example 4 A capacitor was fabricated in the same manner as in Example 1, except that a porous Ni body was used as the lower electrode. The porous Ni body was fabricated as follows.

[0123] The Ni conductive paste was applied to a 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 μm.

[0124] A capacitor using the Ni porous body obtained in Example 4 is shown in Figure 5. As shown in Figure 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 capacitor characteristics. The results are shown in Table 4.

[0125]

[0126] 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 capacitor characteristics. The results are shown in Table 5.

[0127]

[0128] 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]

[0130] Comparative Example 3 In Comparative Example 3, a capacitor was fabricated 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 serving as an upper electrode cover the Ni porous body serving as a metal substrate 1 in this order. An extraction electrode 7 made of Cu / Ti covers the periphery of the Ni porous body. The capacitance, BDV, and leakage current were evaluated as capacitor characteristics.

[0131] As a result of the evaluation, the leakage current of the capacitor of Comparative Example 3 was so high that it was impossible to measure the capacitance, BDV, and leakage current, and the capacitor was evaluated as having practical problems.

[0132] [RBS Analysis] Three samples for RBS analysis 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 adhesion layer) and a 200 nm thick Ni layer (i.e., a layer corresponding to a lower electrode) were formed on the Si substrate by sputtering in this order. The Si substrate with the formed layers was designated Sample 1.

[0134] [Sample 2] Sample 1 was placed in the vacuum chamber of an ALD apparatus. 3DMAS was used as a precursor and O was used as an oxidant. ３ At 250°C, SiO with a thickness of about 3 nm was formed. ２ An oxygen barrier layer made of Ni was formed on the layer made of Ni of Sample 1. The sample with the oxygen barrier layer formed thereon 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: 450 keV He ＋ Detected ions: scattered He ＋ ・Scattering angle: 70° ・Incidence angle ＊: 55° Specimen current: 10 nA Irradiation dose: 12.5 μC In-plane rotation: None Detector ＊＊ : MCP / PSD ＊ Angle from the normal to the 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]

[0139] [Sample 1] A region consisting of only 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 thought to be a layer formed by 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 consisting of only 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 composed of SiO ２ The thickness of the layer was 3.7 nm.

[0143] A region composed of Ni atoms and O atoms was confirmed. This region is thought to be a layer formed by 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 was composed of Ni atoms and O atoms of the first oxidized region and SiO atoms of the oxygen barrier layer. ２ This corresponds to the second oxidation 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 consisting of only 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 composed of SiO ２ The thickness of the layer was 3.2 nm.

[0148] A region composed of Ni atoms and O atoms was confirmed. This region is thought to be a layer formed by 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 was composed of Ni atoms and O atoms of the first oxidized region and SiO atoms of the oxygen barrier layer. ２ This corresponds to the second oxidation 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 was smaller in Sample 3 than in Sample 2. This is thought 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, those skilled in the art will easily understand that the capacitor of the present disclosure is not limited to these and that various embodiments are possible.

[0153] The capacitors disclosed herein include the following: <1> 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, wherein the oxide layer includes a first oxidized region containing a metal forming the metal substrate and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the metal substrate, and 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. <2> The capacitor according to <1>, wherein the atoms forming the oxygen barrier layer include at least one of metal and semimetal atoms. <3> The capacitor according to <1> or <2>, 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 according to any one of <1> to <3>, wherein the oxygen barrier layer is an oxide, a nitride, an oxynitride, or a combination thereof. <5> The capacitor according to any one of <1> to <4>, wherein the oxygen barrier layer and the dielectric layer are formed of the same material. <6> The capacitor according to any one of <1> to <4>, wherein the dielectric layer is formed of a material different from that of the oxygen barrier layer. <7> The capacitor according to any one of <1> to <6>, wherein the thickness of the oxygen barrier layer is 20% or less of the thickness of the dielectric layer. <8> The capacitor according to any one of <1> to <7>, wherein the thickness of the oxide layer is 10% or less of the thickness of the dielectric layer. <9> The capacitor according to any one of <1> to <8>, wherein the metal substrate is a porous metal substrate. <10> The capacitor according to any one of <1> to <9>, wherein the metal forming the metal substrate contains a base metal. <11> The capacitor according to any one of <1> to <10>, wherein the metal forming the metal substrate contains at least one element selected from the group consisting of Cu, Al, Ta, Ti, Ni, Nb, W, Cr, and Fe.<12> The capacitor according to any one of <1> to <11>, wherein the dielectric layer contains at least one element selected from the group consisting of Al, Si, Ti, Hf, Ta, Zr, Sr, Pb, and Ba. <13> The capacitor according to any one of <1> to <12>, wherein the conductive layer contains at least one element selected from the group consisting of Ti, W, Ni, Cu, Ag, Ru, and Pt. <14> The capacitor according to any one of <1> to <13>, wherein the conductive layer is a nitride film conductive layer. <15> The capacitor according to any one of <1> to <14>, 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> A method for manufacturing a capacitor, comprising: forming an oxygen barrier layer on a metal substrate; reducing the metal substrate 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 capacitor component comprising: a first electrode, a dielectric layer formed on the first electrode, an oxide layer formed between the first electrode and the dielectric layer, and an oxygen barrier layer formed between the oxide layer and the dielectric layer, wherein the oxide layer comprises a first oxidized region containing a metal forming the first electrode, and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the first electrode, 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 according to <17>, wherein the first electrode is a porous metal substrate.

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

[0155] 100, 100' Capacitor 1, 1' Metal substrate 2, 2' Dielectric layer 3, 3' Conductive layer 4, 4' Oxide layer 41 First oxidized region 42 Second oxidized region 5 Oxygen barrier layer 6' Crack 7 Extraction electrode 8 Ni plate

Claims

1. 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, wherein the oxide layer comprises a first oxidized region containing a metal forming the metal substrate and a second oxidized region containing atoms forming the oxygen barrier layer and a metal forming the metal substrate, and the thickness of the first oxidized region is 3 nm or less and is 0% or more and 50% or less of the thickness of the second oxidized region.

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

3. The capacitor according to claim 1 or 2, 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 any one of claims 1 to 3, wherein the oxygen barrier layer is an oxide, a nitride, an oxynitride, or a combination thereof.

5. The capacitor according to any one of claims 1 to 4, wherein the oxygen barrier layer and the dielectric layer are formed from the same material.

6. The capacitor according to any one of claims 1 to 4, wherein the dielectric layer is formed of a material different from that of the oxygen barrier layer.

7. The capacitor according to any one of claims 1 to 6, wherein the thickness of the oxygen barrier layer is 20% or less of the thickness of the dielectric layer.

8. The capacitor according to any one of claims 1 to 7, wherein the thickness of the oxide layer is 10% or less of the thickness of the dielectric layer.

9. The capacitor according to any one of claims 1 to 8, wherein the metal substrate is a porous metal substrate.

10. The capacitor according to any one of claims 1 to 9, wherein the metal forming the metal substrate comprises a base metal.

11. The capacitor according to any one of claims 1 to 10, wherein 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.

12. The capacitor according to any one of claims 1 to 11, wherein the dielectric layer contains at least one element selected from the group consisting of Al, Si, Ti, Hf, Ta, Zr, Sr, Pb, and Ba.

13. The capacitor according to any one of claims 1 to 12, wherein the conductive layer contains at least one element selected from the group consisting of Ti, W, Ni, Cu, Ag, Ru, and Pt.

14. The capacitor according to any one of claims 1 to 13, wherein the conductive layer is a nitride conductive layer.

15. The capacitor according to any one of claims 1 to 14, 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 capacitor of claim 1, wherein the metal substrate is nickel, and the oxygen barrier layer comprises at least one selected from the group consisting of silicon oxide, aluminum oxide, and hafnium oxide.

17. A method for manufacturing a capacitor, comprising: forming an oxygen barrier layer on a metal substrate; subjecting the metal substrate on which the oxygen barrier layer is formed to a reduction treatment; forming a dielectric layer on the oxygen barrier layer; and forming a conductive layer on the dielectric layer.

18. A capacitor component comprising: a first electrode; a dielectric layer formed on the first electrode; an oxide layer formed between the first electrode and the dielectric layer; and an oxygen barrier layer formed between the oxide layer and the dielectric layer, wherein the oxide layer comprises a first oxidized region containing a metal forming the first electrode; and a second oxidized region containing atoms forming the oxygen barrier layer and the metal forming the first electrode, wherein the thickness of the first oxidized region is 3 nm or less and is 0% or more and 50% or less of the thickness of the second oxidized region.

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

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