JP5263915B2 - Capacitor element manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a capacitor element that can substantially improve the dielectric constant of a dielectric material film, and also can control the deterioration of insulation characteristics. <P>SOLUTION: A lower electrode layer 12, a dielectric material layer 13, and an upper electrode layer 14 are sequentially laminated on a substrate 11. The dielectric material layer 13 is formed by an aerosol deposition method, by utilizing a fine particle material of fine particle formed of a composite material of a dielectric material member and a conductive material. The fine particle material may adopt ceramic particles, covered at least at a part of the surface with the conductive material, conductive particles covered at least at a part of the surface with the ceramic material, and fine particles on which the conductive particle and ceramic particle are mutually deposited. The dielectric material layer 13 has a structure where the fine particle is solidified through the application of impacts, and a conductor 16b is dispersed at random and is connected electrically to each other inside a dielectric material 16a. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method of manufacturing a capacitor element including a dielectric film that is impacted and solidified by spraying an aerosolized fine particle material.

  Information processing related electronic equipment such as personal computers, office computers, mobile phones, PDAs, etc., communication related electronic equipment and semiconductors such as mounting boards and packages incorporated in control machine equipment such as semiconductor manufacturing equipment, semiconductors such as memory and logic, In the individual electronic components for mounting, various dielectric ceramics for realizing active functions such as memory / calculation and passive functions such as an antenna, a filter, and a capacitor are formed in a film or a bulk. These devices / parts are configured by integrating dielectric ceramics with inorganic materials such as metals and semiconductors, organic materials such as glass epoxy resins, and the like by combining and multilayering them.

  There has been proposed an aerosol deposition method capable of forming a ceramic film on a substrate by impact and solidification by injecting a ceramic fine particle material onto the substrate or the like. The aerosol deposition method is a film forming method in which ceramic fine particles raised by vibrations form an aerosol, the aerosol is transported with a gas, and sprayed from a nozzle to a substrate at a high speed. The aerosol deposition method is attracting attention as a method capable of forming a composite material because it can be formed at room temperature (see, for example, Patent Document 1 or 2).

Patent Document 1 proposes a capacitor element having a dielectric layer formed by simultaneously spraying a dielectric fine particle material and a conductive fine particle material. It is presumed that the dielectric layer has a substantial increase in dielectric constant because conductive fine particles enter between the fine dielectric particles so that a large number of minute capacitors are electrically connected in parallel.
JP 2005-109017 A JP-A-2005-005645

  However, in Patent Document 1, since the dielectric fine particle material and the conductive fine particle material are formed by jetting simultaneously, a region where the dielectric fine particle material and the conductive fine particle material are non-uniformly microscopically. In such a case, there is a problem that the insulation characteristics deteriorate and the leakage current increases.

  Accordingly, the present invention has been made in view of the above-mentioned concerns, and an object of the present invention is to improve a substantial dielectric constant of a dielectric film and to provide a capacitor element manufacturing method capable of suppressing deterioration of insulation characteristics. Is to provide.

According to one aspect of the present invention, a step of forming a first electrode layer, a step of forming a dielectric layer on the surface of the first electrode layer, and a second electrode layer on the dielectric layer A step of forming, between the step of forming the first electrode layer and the step of forming the dielectric layer, and between the step of forming the dielectric layer and the step of forming the second electrode layer The method further includes forming a fine particle aerosol made of only a dielectric material between at least one of the dielectric material and spraying the aerosol onto the surface of the first electrode layer or the dielectric layer, thereby forming the dielectric layer. to process the fine particles of composite material of a dielectric material and a conductive material aerosolized, the capacitor element, characterized in that depositing by blowing aerosolized particulate material to the surface of the first electrode layer A manufacturing method is provided.

  According to the present invention, fine particles made of a composite material of a dielectric material and a conductive material are aerosolized and sprayed onto the electrode layer to be impacted and solidified. Therefore, microscopically, dielectric parts and conductive parts are alternately deposited, and it is estimated that a structure in which a large number of minute capacitors are connected is formed. Further, since the dielectric portion and the conductive portion are derived from the dielectric material and conductive material of the respective fine particles, they are uniformly arranged in the dielectric layer. Therefore, it is possible to suppress the deterioration of the insulating characteristics of the dielectric layer. Therefore, it is possible to form a capacitor element capable of increasing the substantial dielectric constant of the dielectric layer and suppressing the deterioration of the insulation characteristics.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the substantial dielectric constant of a dielectric film, the manufacturing method of the capacitor element which can suppress deterioration of an insulation characteristic can be provided.

  Hereinafter, the present invention will be described more specifically with reference to the drawings as necessary.

(First embodiment)
FIG. 1 is a cross-sectional view of a capacitor element manufactured by the manufacturing method according to the first embodiment of the present invention. Referring to FIG. 1, a capacitor element 10 according to the manufacturing method according to the present embodiment has a structure in which a substrate 11 and a lower electrode layer 12, a dielectric layer 13, and an upper electrode layer 14 are sequentially stacked on the substrate 11. It has become.

  As a result of earnest study, the inventor of the present application uses a fine particle made of a composite material of a dielectric material and a conductive material by using an aerosol deposition method (hereinafter abbreviated as “AD method”), and a capacitor element. It was found that when the dielectric layer is formed, the capacitance is remarkably increased as compared with the case where fine particles of only the dielectric material are used. Furthermore, the present inventors have found that a dielectric layer having a more uniform and more stable characteristic can be formed as compared with a dielectric layer formed by spraying a dielectric fine particle material and a conductive fine particle material independently by aerosolization. The mechanism is guessed as follows.

  FIG. 2 is a schematic cross-sectional view of the main part of the capacitor element. Referring to FIG. 2, the dielectric layers 13 are electrically connected to each other while the conductor portions 16b formed of the conductive material are randomly dispersed in the dielectric portions 16a formed by solidifying the dielectric material. It is assumed that the conductor portion 16b has a structure in which the conductor portion 16b is electrically connected to the lower electrode layer 12 or the upper electrode layer 14.

  FIG. 3 is an equivalent circuit diagram of the capacitor element shown in FIG. Referring to FIG. 3 together with FIG. 2, a large number of microcapacitors 18 are formed in the dielectric layer 13. The conductor portion 16b (shown in FIG. 2) functions as the electrode and wiring 18b of the microcapacitor 18, and the dielectric portion 16a (shown in FIG. 2) functions as the dielectric layer 18a of the microcapacitor 18. The micro capacitors 18 are electrically connected to each other and are connected to the lower electrode layer 12 or the upper electrode layer 14. Since the dielectric layer 13 has such a structure, it is presumed that the capacitance increases more than when the capacitor element has a dielectric layer made of only a dielectric material formed by a normal AD method. Therefore, the dielectric layer 13 has a substantial dielectric constant higher than that of a dielectric layer made of only a dielectric material formed by the AD method.

  Returning to FIG. 1, the capacitor element manufacturing method according to the first embodiment of the present invention includes a step of forming the lower electrode layer 12 on the substrate 11, and a formation of the dielectric layer 13 on the surface of the lower electrode layer 12. And a step of forming the upper electrode layer 14 on the dielectric layer 13.

  The substrate 11 is, for example, a silicon substrate or a glass epoxy substrate, and may be an interlayer insulating film instead of the substrate, or may be a process substrate that is removed after the capacitor element is formed.

  The lower electrode layer 12 and the upper electrode layer 14 are made of a conductive material, for example, a metal such as Al, Cu, W, Au, Pt, Mo, Pd, Ir, or an alloy material thereof, or a conductive oxide material. It can be formed by a method, a sputtering method, a vacuum deposition method, a CVD (chemical vapor deposition) method, or the like.

  The dielectric layer 13 is an impact solidified film formed by using a fine particle material in which individual fine particles are made of a composite material of a dielectric material and a conductive material by an AD method. Although the thickness of the dielectric material layer 13 is suitably selected according to the electrostatic capacitance calculated | required by a capacitor element and a use, it is selected from the range of 0.3 micrometer-300 micrometers, for example.

  Examples of the particulate material include (1) ceramic particles in which at least part of the surface is covered with a conductive material, (2) conductive particles in which at least part of the surface is covered with a ceramic material, and (3) conductivity. Examples thereof include fine particles in which particles and ceramic particles adhere to each other.

  Examples of the fine particles of (1) include fine particles in which a conductive material is formed on the surface of ceramic particles by any one of an electroplating method, an electroless plating method, a sputtering method, and a vacuum deposition method. The conductive material may be formed on a part of the surface of the ceramic particles, or may be formed on the entire surface.

  In addition, as the fine particles of (2), a ceramic material is formed on the surface of conductive particles by any one of sputtering, chemical vapor deposition, thermal oxidation, anodic oxidation, and pulsed laser ablation. And fine particles formed. The ceramic material may be formed on a part of the surface of the conductive particles, or may be formed on the entire surface.

  Moreover, as the fine particles of (3), fine particles obtained by mechanically mixing conductive particles and ceramic particles and applying an impact are combined. For the formation of such fine particles, for example, a high-speed rotary impact pulverization apparatus such as a pin mill, a disk mill, or a centrifugal classifier can be used. In the high-speed rotational impact pulverization method, conductive particles and ceramic particles are mixed and simultaneously subjected to impact, whereby either the conductive particles or the ceramic particles are used as core particles, and the other adheres to the surface of the core particles. In this case, it is preferable that the average particle size of the core particles is set larger than the fine particles to be adhered.

Specific examples of the ceramic particles (1) and (3) include ceramic particles such as TiO ₂ , MgO, SiO ₂ , AlN, and Al ₂ O _3, and oxide ceramics having a perovskite structure. For example, PbT-based PbTiO ₃ , PbZrO ₃ , PbT (Zr _1−x Ti _x ) O ₃ (0 ≦ x ≦ 1) represented by the general formula, (Pb _1−y La _y ) (Zr ₁₋ PLZT, Pb (Mg _1/3 Nb _2/3 ) O ₃ , Pb (Ni _1/3 Nb _2/3 ) O _{3 represented by} the general formula of _x Ti _x ) O ₃ (0 ≦ x, y ≦ 1) Pb (Zn _1/3 Nb _2/3 ) O ₃ , Ba-based BaTiO ₃ , BaTi ₄ O ₉ , Ba ₂ Ti ₉ O ₂₀ , Ba (Zn _1/3 Ta _2/3 ) O ₃ , Ba (Zn) _1/3 Nb _2/3 ) O ₃ , Ba (Mg _1/3 Ta _2/3 ) O ₃ , Ba (Co _1/3 Ta _2/3 ) O ₃ , Ba (Co _1/3 Nb _2/3 ) O _{3 Ba (Ni 1/3 Ta 2/3) O} 3, (BaSr) TiO 3, Ba (TiZr) O 3, _{other, CaTiO 3, CaZrO 3, MgTiO} 3, MgZrO 3, Nd 2 Ti 2 O 7, SrTiO 3 , SrZrO ₃ , and ZrSnTiO ₄ .

The ceramic particles of the above (1) and (3) are made of TiO ₂ , BaTiO ₃ , BaSrTiO ₃ , BaTiZrO ₃ , BaTi ₄ O ₉ , Ba ₂ Ti ₉ from the viewpoint of high dielectric constant and low loss at high frequency. O ₂₀ , Ba (Mg _1/3 Ta _2/3 ) O ₃ , Ba (Zn _1/3 Ta _2/3 ) O ₃ , Ba (Zn _1/3 Nb _2/3 ) O ₃ , ZrSnTiO ₄ , PbZrTiO ₃ One or a mixture of two or more selected from Pb (Mg _1/3 Nb _2/3 ) O ₃ and Pb (Ni _1/3 Nb _2/3 ) O ₃ is preferred.

  The ceramic material formed on the surface of the conductive particles (2) is selected from the same materials as the ceramic particles (1) and (3).

  Specific examples of the conductive particles of the above (2) and (3) include B, Ge, Si, Bi, Ti, Cr, Pt, Pd, In, Ru, Ni, Mo, Co, W, Examples thereof include metal elements such as Ir, Al, Au, Cu, and Au, and alloys composed of these metal elements.

Further, specific materials for the conductive particles of the above (2) and (3) include RuO ₂ , IrO ₂ , ReO ₃ , SrVO ₃ , SrRuO ₃ , SrMoO ₃ , CaRuO ₃ , BaRuO ₃ , PbRuO ₃ , BiRuO. ₃ , conductive oxides such as LaTaO ₃ and Bi ₂ Ru ₂ O ₇ , LaB _{6 and the} like. The conductive material formed on the surface of the ceramic particle (1) is selected from the same materials as the conductive particles (2) and (3).

The conductive particles preferably have a specific resistance at room temperature of 1 × 10 ⁻² Ω · cm or less, and more preferably 1 × 10 ⁻³ Ω · cm or less. The specific resistance is preferably as small as possible, but is set to 1 × 10 ⁻⁷ Ω · cm or more.

  In addition, the conductive material of (1) and the conductive particles of (2) and (3) are set in a range of 0.01 vol% to 20 vol% based on the volume of the ceramic particles and the ceramic material, respectively. It is preferably set in the range of 0.1 vol% to 5 vol%. If it exceeds 20 vol%, the conductivity becomes remarkable and the dielectric loss at high frequency increases.

  Moreover, the average particle diameter of the fine particles (1) to (3) is set in the range of 10 nm to 10 μm. If it is smaller than 10 nm, the adhesion strength to the substrate is insufficient, and if it is larger than 10 μm, it becomes difficult to form a continuous film, resulting in a fragile film.

  Next, a process for forming the dielectric layer 13 by the AD method will be described.

  FIG. 4 is a schematic configuration diagram of a film forming apparatus using the AD method used in the present invention. Referring to FIG. 4, an AD film forming apparatus 50 generally includes an aerosol generator 51 that aerosolizes a particulate material, and a lower electrode layer formed on the substrate 11 by spraying the aerosolized particulate material. The film forming chamber 52 is formed with a dielectric layer formed thereon.

  A gas cylinder 53 and a mass flow controller 54 are connected to the aerosol generator 51 via a pipe 66. A mass flow controller 54 controls a carrier gas such as high-pressure argon filled in the gas cylinder 53. The mass flow controller 54 can control the amount of fine particles generated in the container 56 of the aerosol generator 51 and the amount of aerosolized fine particles ejected in the film forming chamber 52. As the carrier gas, an inert gas such as helium, neon, or nitrogen can be used in addition to argon gas. When an oxide ceramic having a perovskite structure is used as the fine particle material, the carrier gas may be an oxidizing gas such as oxygen or air, or these gases may be added to an inert gas. Oxygen vacancies in the oxide ceramic fine particle material can be compensated for during film formation.

  The container 56 is filled with the fine particle material of any one of (1) to (3) described above, in which each fine particle is made of a composite material of a dielectric material and a conductive material.

  Further, the aerosol generator 51 is provided with a vibrator 58 for converting the fine particles into primary particles by ultrasonic vibration, electromagnetic vibration, or mechanical vibration in the container 56. The fine particles can be made primary particles by the vibrator 58, and as a result, a dense and uniform interlayer insulating layer or the like can be formed.

  The film formation chamber 52 is provided with a nozzle 60 connected from the aerosol generator 51 via a pipe 59, and a substrate holding table 61 that holds the substrate 11 so as to face the nozzle 60. An XYZ stage 62 to be controlled is connected to the substrate holder 61. Further, a mechanical booster 64 and a rotary pump 65 for connecting the film forming chamber 52 to a low pressure are connected. The XYZ stage 62 may perform a constant speed / repetitive driving operation of the substrate holder 61.

Fine particles as a film forming material are filled in the container 56 of the aerosol generator 51, and from the gas cylinder 53, for example, an argon gas having a pressure of 19.6 Pa to 49 Pa (2 to 5 kg / cm ² ) is used as a carrier gas to form a film forming chamber 52. The fine particles are vibrated by the vibrator 58 to be aerosolized. The aerosolized fine particles are transferred together with the carrier gas through the pipe 59 to the film forming chamber 52 set to a pressure lower than the pressure in the container 56. In the film forming chamber 52, fine particles are ejected together with the carrier gas from the nozzle 60, and the fine particles are deposited on a lower electrode layer (not shown) on the substrate 11 to form a dielectric layer. The injection speed can be controlled by the shape of the nozzle 60, the pressure of the introduced carrier gas, and the pressure difference between the inside of the container 56 and the film forming chamber 52, and is 3 m / second to 400 m / second (preferably 200 m / second). ˜400 m / sec). By setting the ejection speed within this range, a dielectric layer having high adhesion strength with the substrate such as the substrate 11 can be formed. When the fine particles collide with the substrate 11, the surface of the substrate 11 or the like is removed to activate the surface by removing the contaminated layer, and the surface of the fine particles themselves is similarly activated by the collision of the fine particles. As a result, since the fine particles are bonded to the surface of the substrate 11 or the like and the fine particles are bonded together, a dense dielectric layer having high adhesion strength is formed. Note that if the jetting speed is higher than 400 m / sec, the substrate 11 may be damaged, and if it is lower than 3 m / sec, sufficient adhesion strength cannot be ensured.

  FIGS. 5A to 5D are diagrams showing how the dielectric layer is formed by the AD method. Here, the case where the fine particles (1) are used will be described as an example.

  As shown in FIG. 5A, aerosolized fine particles 16 are sprayed onto the lower electrode layer 12 at a high speed. The fine particles 16 have a structure in which ceramic particles 16a are covered with a metal film 16b.

  Next, as shown in FIG. 5B, the fine particles 16 collide with the lower electrode layer 12, and the fine particles 16 are deformed and crushed by the impact.

  Next, as shown in FIG. 5C, the metal coating 16 b is destroyed as the fine particles 16 are deformed.

  Next, as shown in FIG. 5D, other fine particles 16 are similarly deposited on the fine particles 16 already deposited through the processes of FIGS. 5A to 5C, and the metal coatings 16b come into contact with each other. Are electrically connected. In this way, the structure of the dielectric layer 13 shown in FIG. 2 is formed.

  According to the first embodiment, the capacitor element 10 includes the dielectric layer 13 made of a solidified film that is collided and solidified using a fine particle material by the AD method. In the fine particle material, each fine particle is composed of a composite material of a dielectric material and a conductive material. Therefore, microscopically, dielectric portions and conductive portions are alternately deposited on a fine particle dielectric material, and the dielectric layer 13 has a structure in which a large number of minute capacitors are uniformly connected. It is estimated to be. Therefore, the capacitor element 10 can increase the substantial dielectric constant of the dielectric layer 13 and can suppress deterioration of the insulation characteristics.

(Second Embodiment)
FIG. 6 is a cross-sectional view of a capacitor element manufactured by the manufacturing method according to the second embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 6, capacitor element 20 according to the manufacturing method according to the present embodiment includes substrate 11, lower electrode layer 12, second dielectric layer 21, first dielectric layer 13, first dielectric layer 13 on substrate 11. The three dielectric layers 22 and the upper electrode layer 14 are sequentially stacked. Capacitor element 20 of the present embodiment includes a lower electrode layer 12 and a first dielectric layer 13 (same as dielectric layer 13 of the capacitor element shown in FIG. 1), and the first dielectric layer. The main feature is that the second dielectric layer 21 and the third dielectric layer 22 are formed between the upper electrode layer 14 and the upper dielectric layer 13, respectively.

  The capacitor element manufacturing method according to the second embodiment of the present invention includes a step of forming the lower electrode layer 12 on the substrate 11 and a step of forming the second dielectric layer 21 on the surface of the lower electrode layer 12. A step of forming the first dielectric layer 13 on the surface of the second dielectric layer 21; a step of forming the third dielectric layer 22 on the surface of the first dielectric layer 13; And the step of forming the upper electrode layer 14. Note that either the step of forming the second dielectric layer 21 or the step of forming the third dielectric layer 22 may be omitted.

  The second dielectric layer 21 and the third dielectric layer 22 are made of only a dielectric material and do not contain a conductive material. By providing at least one of the second dielectric layer 21 and the third dielectric layer 22, the leakage current of the capacitor element can be greatly reduced. The second dielectric layer 21 and the third dielectric layer 22 are formed by the AD method using ceramic particles used for the dielectric layer 13 in the first embodiment, for example. Further, the second dielectric layer 21 and the third dielectric layer 22 may be formed using any one of a sputtering method, a chemical vapor deposition method, a thermal oxidation method, an anodic oxidation method, and a pulse laser ablation method. Good. Although the film thickness of the 2nd dielectric material layer 21 and the 3rd dielectric material layer 22 can be selected suitably, it selects from the range of 0.3 micrometer-300 micrometers, for example.

  The first dielectric layer 13 is a layer corresponding to the dielectric layer 13 of the capacitor element shown in FIG. 1, and is formed by the material and the forming method described in the first embodiment.

  According to the second embodiment, between the lower electrode layer 12 and the first dielectric layer 13 (the same as the dielectric layer 13 of the capacitor element shown in FIG. 1), and the first dielectric layer. 13 and the upper electrode layer 14 are provided with at least one of the second dielectric layer 21 and the third dielectric layer 22 made of a dielectric material not including a conductive material, thereby reducing the leakage current of the capacitor element 20. It can be greatly reduced.

  Examples of the first and second embodiments and comparative examples not according to the present invention will be described below.

[Example 1]
BaTiO ₃ powder (gold-coated BaTiO ₃ powder) with an average particle size of 0.5 μm having an Au film with a thickness of about 0.1 μm on the surface is placed in an aerosol generator container, and ultrasonic waves are applied to the entire container, about 150 degrees. While being heated at 50 ° C., it was vacuum degassed for 30 minutes to remove moisture formed on the surface of the gold-coated BaTiO ₃ powder.

The gold-coated BaTiO ₃ powder was produced using electroless plating. The following liquid is used for the electroless plating bath. A gold solution is prepared by diluting 10 g of gold chloride and 5 g of sodium chloride with water to make a total of 800 mL. Next, a reducing solution of 22.5 g of tartaric acid, 300 g of sodium hydroxide, 380 mL of alcohol, and 600 mL of water is prepared. The electroless plating bath is prepared by mixing 30 mL of gold solution and 70 mL of reducing solution. BaTiO ₃ powder is immersed in this electroless plating bath for 20 minutes to deposit gold on the surface. Thereafter, it was washed with water, and the liquid content was dried at 150 ° C. for 3 hours to prepare a gold coating powder.

  In the electroless plating bath, potassium gold cyanide may be used as a gold component. The electroless plating bath is, for example, a mixture of potassium gold cyanide 2 g / L, ammonium chloride 75 g / L, sodium citrate 50 g / L, sodium hypophosphite 10 g / L, pH 7 to 7.5, temperature Adjust to about 95 ° C.

Next, using the film formation apparatus 50 by the AD method shown in FIG. 4, the flow rate is set to 4 L / min using high purity nitrogen gas (purity 99.9%) at a pressure of 19.6 Pa as a carrier gas, and the gold film BaTiO _{3 is used.} A powder aerosol was formed. The film formation chamber was set to 5 Pa to 10 Pa and sprayed for 30 minutes to form a dielectric layer having a thickness of 2 μm on the glass substrate on which the lower electrode layer was formed. Further, an upper electrode layer was formed thereon by sputtering.

  The lower electrode layer was a Cr film (thickness 0.1 μm) / Cu film (thickness 0.5 μm) laminate from the glass substrate side, and the upper electrode was a Cu film (thickness 0.5 μm).

[Example 2]
In Example 2, a capacitor element was prepared in the same manner as in Example 1 except that Al powder (oxide film Al powder) having an average particle diameter of 1 μm with an aluminum oxide layer having a thickness of 0.1 μm formed on the surface was used. Formed. The oxide-coated Al powder was heated in an oven at 350 ° C. for 30 hours to form an aluminum oxide layer of 0.1 μm on the powder surface.

[Example 3]
In Example 3, except for using the BaTiO ₃ powder of an average particle size 0.5μm having a Au film partially having a thickness of about 0.1μm on the surface (Au film deposited BaTiO ₃ powder) in the same manner as in Example 1 Thus, a capacitor element was formed.

Note that the Au film-attached BaTiO ₃ powder was sputtered for 1 minute on the BaTiO ₃ powder using an Au target with a sputtering power of DC 4000 W and an Ar gas supply flow rate of 50 sccm. Note that the volume ratio of the Au film was set to 1 vol% with respect to the volume of the entire Au film-attached BaTiO ₃ powder.

  In the case of the vapor deposition method, an Au film having a thickness of 0.1 μm can be formed by performing Au vapor deposition for 1 minute under the conditions of a current of 80 mA and a voltage of 10 kV.

[Example 4]
Example 4 is an example of the capacitor element according to the second embodiment shown in FIG. The capacitor element of Example 4 is a lower electrode layer of a laminate of Cr film (thickness 0.1 μm) / Cu film (thickness 0.5 μm) from the glass substrate side, having an average particle diameter of 0.05 μm by AD method. Second dielectric layer of alumina film (thickness 0.2 μm) on which alumina particles are deposited, first dielectric layer (thickness 2 μm) on which composite powder is deposited by AD method, average particle size 0 by AD method A third dielectric layer of alumina film (thickness 0.2 μm) on which 0.05 μm alumina particles were deposited and an upper electrode layer of Cu film (thickness 0.5 μm) were laminated. The film forming conditions for the first to third dielectric layers were the same as in Example 1.

The composite powder of the first dielectric layer is a composite of BaTiO ₃ powder having an average particle size of 0.5 μm and Au powder having an average particle size of about 1 μm using a disk mill. In addition, the volume ratio of Au powder was set to 5 vol% with respect to the volume of the whole powder.

[Comparative Example 1]
In Comparative Example 1, a capacitor element was formed in the same manner as in Example 1 except that a mixed powder obtained by mixing a BaTiO ₃ powder having an average particle diameter of 0.5 μm and an Au powder having an average particle diameter of about 1 μm by a ball mill was used. In addition, the volume ratio of Au powder was set to 5 vol% with respect to the volume of the whole powder.

[Comparative Example 2]
BaTiO ₃ powder having an average particle size of 0.5 μm was placed in an aerosol generator container, and ultrasonic waves were applied to the entire container and vacuum degassed for 30 minutes while heating at about 150 ° C. to form the surface of the BaTiO ₃ powder. Water was removed.

  Next, an aerosol of BaTiO3 powder is formed by using the film formation apparatus 50 by the AD method shown in FIG. Formed. The film formation chamber was set to 5 Pa to 10 Pa and sprayed for 30 minutes to form a dielectric layer having a thickness of 2 μm on the glass substrate on which the lower electrode layer was formed. Further, an upper electrode layer was formed thereon by sputtering. The configurations of the lower electrode layer and the upper electrode layer were the same as in Example 1.

  FIG. 7 is a characteristic diagram of the capacitor elements of the example and the comparative example. “Unmeasurable” in the leakage current column of the comparative example indicates that the measurement was not possible because the leakage current was excessive.

Referring to FIG. 7, it can be seen that Examples 1 to 4 have extremely low leakage current and superior insulation characteristics to Comparative Example 1 compared to Comparative Example 1. In addition, Example 4 has the lowest leakage current among Examples 1 to 4. It can be seen that the insulating properties were further improved by the alumina film formed between the first dielectric layer and the lower and upper electrode layers made of the composite powder of BaTiO ₃ powder and Au powder.

In Example 1, when compared with Comparative Example 2, the mean relative permittivity has increased significantly, the mean relative permittivity by using gold film BaTiO ₃ powder with respect to BaTiO ₃ powder is greatly increased I understand that. As a result, it can be seen that the capacitance density of Example 1 is significantly increased compared to Comparative Example 2.

  The average relative dielectric constant was measured by applying a high frequency voltage of 1 GHz to the capacitor electrode. Dielectric loss was measured using a network analyzer using the perturbation method.

  The capacitance density is the total capacitance of the capacitors formed in layers in each of the examples and comparative examples, divided by the area of the circuit board, and the capacitance per unit area. Is expressed.

(Third embodiment)
FIG. 8 is a cross-sectional view showing a schematic configuration of a circuit board according to the third embodiment.

  Referring to FIG. 8, a circuit board 30 is formed on a base board 31 made of a double-sided copper-clad board FR-4 board on which through holes 32A and conductor layers 32B are formed, and on one main surface of the base board 31. And the dielectric layers 34-1 to 34-3 disposed between the insulating layers 33-1 to 33-4 and the lower electrode layers 36-1 to 36-3. The capacitors 37-1 to 37-3 formed between the upper electrode layers 38-1 to 38-3 and the first electrode layer 46 / dielectric layer 44 formed on the other main surface of the base substrate 31. / Second electrode layer 48 / dielectric layer 44 is composed of a capacitor 47 formed by alternately repeating. Further, a resistance element 42, an LSI 40, and the like are formed on the surface of the circuit board 30.

  The circuit board 30 is characterized in that the capacitors 37-1 to 37-3 and the capacitor 47 have the same configuration as the capacitor elements 10 and 20 according to the first and second embodiments shown in FIGS. is there. Therefore, since the capacitors 37-1 to 37-3, 47 have a high capacitance, the size (corresponding to the area) in the in-layer direction can be reduced.

  In particular, the capacitor 47 used for decoupling usually occupies a relatively large area of the circuit board. However, in the present embodiment, the capacitor 47 can be reduced in size, and the circuit board 30 can be reduced in size.

  In addition, since the capacitors 37-1 to 37-3, 47 can be formed by a low temperature process, dimensional variations and the like can be reduced. For example, it is possible to reduce the variation in capacitance caused by the dimensional change of the capacitors 37-1 to 37-3.

  Furthermore, thermal deformation, dimensional variation, etc. of the circuit board 30 can be reduced, and a small and highly accurate circuit board incorporating the capacitors 37-1 to 37-3, 47 can be realized. As a result, by using the miniaturized circuit board 30, wiring between active elements such as the LSIs 40 can be shortened, and transmission speed and operation speed can be improved.

  In this embodiment, the example in which the dielectric layers 34-1 to 34-3 are formed in layers on the circuit board is shown. However, a dielectric layer is formed on part of the insulating layers 33-1 to 33-4. A capacitor may be provided. The dielectric layer can be formed by patterning such as dry etching.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims.・ Change is possible. For example, the capacitor element formed by the manufacturing method according to the first and second embodiments is not particularly limited, and may be a single capacitor such as a multilayer ceramic capacitor.

In addition, the following additional notes are disclosed regarding the above description.
(Appendix 1) A step of forming a first electrode layer, a step of forming a dielectric layer on the surface of the first electrode layer, and a step of forming a second electrode layer on the dielectric layer Including
The step of forming the dielectric layer is characterized by aerosolizing fine particles made of a composite material of a dielectric material and a conductive material, and spraying and depositing the aerosolized fine particle material on the surface of the first electrode layer. A method for manufacturing a capacitor element.
(Additional remark 2) The said microparticles | fine-particles consist of ceramic particle | grains by which at least one part of the surface was covered with the electroconductive material, The manufacturing method of the capacitor element of Additional remark 1 characterized by the above-mentioned.
(Additional remark 3) The said microparticles | fine-particles form the electroconductive material on the surface of a ceramic particle by any one method among an electroplating method, an electroless-plating method, a sputtering method, and a vacuum evaporation method, It is characterized by the above-mentioned. The manufacturing method of the capacitor element of description.
(Additional remark 4) The said microparticles | fine-particles consist of electroconductive particle by which at least one part of the surface was covered with the ceramic material, The manufacturing method of the capacitor element of Additional remark 1 characterized by the above-mentioned.
(Supplementary Note 5) The fine particles form a ceramic material on the surface of the conductive particles by any one of sputtering, chemical vapor deposition, thermal oxidation, anodic oxidation, and pulsed laser ablation. The method for manufacturing a capacitor element according to appendix 4, wherein:
(Supplementary note 6) The method for producing a capacitor element according to supplementary note 1, wherein the fine particles are formed by attaching conductive particles and ceramic particles to each other.
(Supplementary note 7) The method of manufacturing a capacitor element according to supplementary note 6, wherein the fine particles are formed by mechanically mixing conductive particles and ceramic particles and applying impact.
(Supplementary Note 8) At least one of the step of forming the first electrode layer and the step of forming the dielectric layer and the step of forming the dielectric layer and the step of forming the second electrode layer Any one of Supplementary notes 1 to 7, further comprising a step of forming an aerosol of fine particles made of only a dielectric material and spraying the aerosol on the surface of the first electrode layer or the dielectric layer. A method for manufacturing a capacitor element according to one item.
(Additional remark 9) The circuit board provided with the capacitor element by which the wiring layer and the interlayer insulation layer were laminated | stacked, and was manufactured by the manufacturing method as described in any one of additional marks 1-8.

It is sectional drawing of the capacitor element by the manufacturing method which concerns on the 1st Embodiment of this invention. It is a typical principal part sectional view of a capacitor element. FIG. 3 is an equivalent circuit diagram of the capacitor element shown in FIG. 2. It is a schematic block diagram of the film-forming apparatus by AD method used for this invention. (A)-(D) are figures which show a mode that a dielectric material layer is formed. It is sectional drawing of the capacitor element by the manufacturing method which concerns on the 2nd Embodiment of this invention. It is a characteristic view of the capacitor element of an Example and a comparative example. It is sectional drawing which shows schematic structure of the circuit board based on the 3rd Embodiment of this invention.

Explanation of symbols

10, 20 Capacitor element 11 Substrate 12 Lower electrode layer 13 Dielectric layer (first dielectric layer)
DESCRIPTION OF SYMBOLS 14 Upper electrode layer 16 Fine particle 16a Dielectric part 16b Conductor part 18 Micro capacitor 18a Dielectric layer 18b Electrode and wiring 21 2nd dielectric layer 22 3rd dielectric layer 30 Circuit board 50 AD film formation apparatus

Claims (4)

Forming a first electrode layer; forming a dielectric layer on the surface of the first electrode layer; and forming a second electrode layer on the dielectric layer;
Between the formation process of the first electrode layer and the formation process of the dielectric layer and between at least one of the formation process of the dielectric layer and the formation process of the second electrode layer Forming a fine particle aerosol made of only a dielectric material, and spraying the aerosol onto the surface of the first electrode layer or the dielectric layer;
The step of forming the dielectric layer, the fine particles of composite material of a dielectric material and a conductive material aerosolized to be deposited by blowing aerosolized particulate material to the surface of the first electrode layer A method of manufacturing a capacitor element. 2. The method of manufacturing a capacitor element according to claim 1, wherein the fine particles made of a composite material of a dielectric material and a conductive material are made of ceramic particles having at least a part of the surface covered with the conductive material. The fine particles made of a composite material of a dielectric material and a conductive material are coated with a conductive material on the surface of the ceramic particles by any one of electroplating, electroless plating, sputtering, and vacuum deposition. 3. The method of manufacturing a capacitor element according to claim 2, wherein the capacitor element is formed. 2. The method of manufacturing a capacitor element according to claim 1, wherein the fine particles made of a composite material of a dielectric material and a conductive material are made of conductive particles having at least a part of the surface covered with a ceramic material.

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