scispace - formally typeset
Search or ask a question

Showing papers on "Tantalum capacitor published in 2007"


Patent
Sam Yang1
31 Oct 2007
TL;DR: Capacitor structures for use in integrated circuits and methods of their manufacture were discussed in this paper, where a bottom electrode, a top electrode and a dielectric layer interposed between the bottom electrode and the top electrode.
Abstract: Capacitor structures for use in integrated circuits and methods of their manufacture. The capacitor structures include a bottom electrode, a top electrode and a dielectric layer interposed between the bottom electrode and the top electrode. The capacitor structures further include a metal oxide buffer layer interposed between the dielectric layer and at least one of the bottom and top electrodes. Each metal oxide buffer layer acts to improve capacitance and reduce capacitor leakage. The capacitors are suited for use as memory cells and apparatus incorporating such memory cells, as well as other integrated circuits.

55 citations


Patent
08 Feb 2007
TL;DR: A conductive polymer solution, comprising a π-conjugated conductive polymeric solution, a polyanion, a conductive improver (or a dopant), an alkaline compound and a solvent, is presented in this article.
Abstract: A conductive polymer solution, comprising a π-conjugated conductive polymer, a polyanion. a conductive improver (or a dopant), an alkaline compound and a solvent. The conductive improver is one or more compounds selected from the group of nitrogen containing aromatic cyclic compounds, compounds containing one or more hydroxyl group, compounds containing two or more carboxyl groups, compounds containing one or more hydroxyl or carboxyl groups, the compound containing an amide group, compounds containing an imide group, lactam compounds, and compounds containing a glycidyl group. Further, the alkaline compound is a nitrogen containing aromatic cyclic compound. A capacitor, comprising an anode (11) composed of a valve metal, a dielectric layer (12) formed by oxidation of a surface of said anode, and a solid electrolyte layer (13) formed on a surface of said dielectric layer, and a cathode layer (14) formed on the solid electrolytic layer is obtained.

45 citations


01 Jan 2007
TL;DR: The tantalum capacitors have been on the market for more than half a century as mentioned in this paper and they still continue to grow, especially, relatively new types of Ta capacitors likeTa capacitors with conductive polymer cathode.
Abstract: Despite constant competition from aluminum and ceramic capacitors, tantalum (Ta) capacitors have been on the market for more than half a century. They still continue to grow, especially, relatively new types of Ta capacitors like Ta capacitors with conductive polymer cathode. The major parameters, which keep Ta capacitors on the market and make them attractive for use in electronic devices, are high volumetric efficiency (CV/cc), low Equivalent Series Resistance (ESR) and Equivalent Series Inductance (ESL), highly stable characteristics with respect to voltage and temperature, and high stability over long periods of time (i.e., high reliability).

42 citations


Patent
08 Oct 2007
TL;DR: In this paper, a semiconductor structure including a capacitor having increased capacitance and improved electrical performance is provided, which includes a substrate, a gate dielectric, and a metal-containing gate electrode.
Abstract: A semiconductor structure including a capacitor having increased capacitance and improved electrical performance is provided. The semiconductor structure includes a substrate; and a capacitor over the substrate. The capacitor includes a first layer including a first capacitor electrode and a second capacitor electrode, wherein the first capacitor electrode is formed of a metal-containing material and is free from polysilicon. The semiconductor structure further includes a MOS device including a gate dielectric over the substrate; and a metal-containing gate electrode on the gate dielectric, wherein the metal-containing gate electrode is formed of a same material, and has a same thickness, as the first capacitor electrode.

39 citations


Journal ArticleDOI
TL;DR: In this article, the practical applications of quaternary ammonium salts for aluminum electrolytic capacitors and double-layer capacitors are reviewed from the historical and technological viewpoints based on research conducted in our laboratory.
Abstract: A capacitor is an electrical device that can store energy in an electric field between a pair of closely spaced conductors. Its application as an energy storage device —an alternative to rechargeable batteries— has been receiving considerable attention. There are chemical capacitors using liquid electrolytes such as aluminum electrolytic capacitors and double-layer capacitors, and they utilize quaternary ammonium salts in their nonaqueous electrolytes. After a brief explanation of the working principles of these chemical capacitors and their requirements for electrolytes, the practical applications of quaternary ammonium salts for aluminum electrolytic capacitors and double-layer capacitors are reviewed from the historical and technological viewpoints based on research conducted in our laboratory.

36 citations


Patent
Jin-Hyock Kim1, Seung-Jin Yeom1, Ki-Seon Park1, Han-Sang Song1, Deok-Sin Kil1, Jae-Sung Roh1 
03 Dec 2007
TL;DR: In this article, a method for fabricating a capacitor includes: forming a storage node contact plug over a substrate, forming an insulation layer having an opening exposing a surface of the storage node contacts plug over the storage contact plug, forming a conductive layer for a stored node over the insulation layer and the exposed surface of a storage nodes contact plug through two steps performed at different temperatures, performing an isolation process to isolate parts of the conductive layers, and sequentially forming a dielectric layer and a plate electrode over the isolated conductive surface.
Abstract: A method for fabricating a capacitor includes: forming a storage node contact plug over a substrate; forming an insulation layer having an opening exposing a surface of the storage node contact plug over the storage contact plug; forming a conductive layer for a storage node over the insulation layer and the exposed surface of the storage node contact plug through two steps performed at different temperatures; performing an isolation process to isolate parts of the conductive layer; and sequentially forming a dielectric layer and a plate electrode over the isolated conductive layer.

35 citations


Patent
21 Feb 2007
TL;DR: In this paper, a high degree of electric strength, a high electrostatic capacity, and a low ESR, which can be readily downsized, is provided for a capacitor.
Abstract: A capacitor having a high degree of electric strength, a high electrostatic capacity, and a low ESR, which can be readily downsized, is provided. The capacitor 10 according to the present invention includes an anode 11 made of porous valve metal, a dielectric layer 12 formed by oxidizing the surface of the anode 11, and a solid electrolyte layer 13 formed on the surface of the dielectric layer 12. The solid electrolyte layer 13 includes a A conjugated conductive polymer, a polyanion, and an ion-conductive compound.

33 citations


Patent
21 Feb 2007
TL;DR: In this article, a high degree of electric strength, a high electrostatic capacity, and a low ESR, which can be readily downsized, is provided, which includes an anode made of porous valve metal, a dielectric layer formed by oxidizing the surface of the anode, and an ion-conductive compound.
Abstract: A capacitor having a high degree of electric strength, a high electrostatic capacity, and a low ESR, which can be readily downsized, is provided. The capacitor according to the present invention includes an anode made of porous valve metal, a dielectric layer formed by oxidizing the surface of the anode, and a solid electrolyte layer formed on the surface of the dielectric layer. The solid electrolyte layer includes a π conjugated conductive polymer, a polyanion, and an ion-conductive compound.

31 citations


Patent
Takatani Kazuhiro1, Mamoru Kimoto1
27 Feb 2007
TL;DR: In this paper, a method of manufacturing a solid electrolytic capacitor is described, which consists of an anode made of valve action metal, a dielectric layer, a liquid electrolytic layer, and a cathode conductive layer.
Abstract: An aspect of the present invention provides a method of manufacturing a solid electrolytic capacitor The solid electrolytic capacitor includes an anode made of valve action metal, a dielectric layer, a solid electrolytic layer, a cathode conductive layer, and a cathode terminal The method forms the cathode conductive layer by forming a conductive paste and conductive adhesive between the solid electrolytic layer and the cathode terminal and then simultaneously hardening the conductive paste and the conductive adhesive

30 citations


Patent
02 Oct 2007
TL;DR: A portion of a conductive layer (310, 910) provides a capacitor electrode (310.0, 9 10) as mentioned in this paper, which is used for conductive paths passing through the electrode but insulated from the electrode.
Abstract: A portion of a conductive layer (310, 910) provides a capacitor electrode (310.0, 910.0). Dielectric trenches (410, 414, 510) are formed in the conductive layer to insulate the capacitor electrode from those portions of the conductive layer which are used for conductive paths passing through the electrode but insulated from the electrode. Capacitor dielectric (320) can be formed by anodizing tantalum while a nickel layer (314) protects an underlying copper (310) from the anodizing solution. This protection allows the tantalum layer to be made thin to obtain large capacitance. Chemical mechanical polishing of a layer (610) is made faster, and hence possibly less expensive, by first patterning the layer photolithographically to form, and/or increase in height, upward protrusions of this layer.

29 citations


Proceedings ArticleDOI
04 Jun 2007
TL;DR: In this paper, an experimental off-line technique that can be used to estimate the condition of aluminum electrolytic capacitors is presented, which is based on the estimation of both ESR and capacitance values.
Abstract: The aim of this paper is to present an experimental off-line technique that can be used to estimate the condition of aluminum electrolytic capacitors. The aging of aluminum electrolytic capacitors is expressed by the increase of their equivalent series resistance (ESR) and the reduction of their capacitance. Thus, the proposed technique is based in the estimation of both ESR and capacitance values. To validate the theoretical equations some experimental and simulated results will be presented.

Patent
22 Aug 2007
TL;DR: In this paper, a circuit structure consisting of a capacitor including a top capacitor electrode, a bottom capacitor electrode parallel to the top capacitance, and an insulating layer between the top and bottom capacitance electrodes is provided.
Abstract: A circuit structure is provided. The circuit structure includes a capacitor including a top capacitor electrode; a bottom capacitor electrode parallel to the top capacitor electrode; and an insulating layer between the top and the bottom capacitor electrodes. The insulating layer includes a dielectric rod enclosed by a dielectric material. The dielectric rod has a higher dielectric constant than that of the dielectric material. The circuit structure may be a printed circuit board or packaging substrate, wherein the capacitor is formed between the two layers of the capacitor. Additional dielectric rods may be formed in the insulating layer of the capacitor and spaced apart from the dielectric rods.

Patent
30 Mar 2007
TL;DR: In this paper, a solid electrolytic capacitor consisting of an organophosphorus material positioned between the dielectric layer and the polymeric electrolyte layer is described, which improves the interlayer adhesion.
Abstract: A solid electrolytic capacitor is disclosed. The capacitor comprises an organophosphorus material positioned between the dielectric layer and the polymeric electrolyte layer. The organophosphorus compound improves the interlayer adhesion between the dielectric and electrolyte layers.

Patent
19 Nov 2007
TL;DR: In this article, a linearized capacitance structure is formed by a first capacitor that is coupled between a first terminal and a common node, combine with a second capacitor, that is coupling between a second terminal and the common node.
Abstract: A highly linearized capacitor structure is formed by a first capacitor, that is coupled between a first terminal and a common node, combine with a second capacitor, that is coupled between a second terminal and the common node. When a bias voltage is applied, the capacitance values of the first and second capacitors combine and a capacitance variation of the first capacitor is compensated by a capacitance variation of the second capacitor to reduce and linearize overall capacitance variation in the combined capacitor structure.

Patent
04 Sep 2007
TL;DR: In this article, a solid electrolytic capacitor that is capable of withstanding laser welding without a significant deterioration in its electrical performance is provided, which is characterized by relatively low ESR and low leakage currents.
Abstract: A solid electrolytic capacitor that is capable of withstanding laser welding without a significant deterioration in its electrical performance is provided. The capacitor contains an anode body, dielectric layer overlying the anode body, and a solid organic electrolyte layer overlying the dielectric layer. Furthermore, the capacitor of the present invention also employs a light reflective layer that overlies the solid organic electrolyte layer. The present inventors have discovered that such a light reflective layer may help reflect any light that inadvertently travels toward the capacitor element during laser welding. This results in reduced contact of the solid organic electrolyte with the laser and thus minimizes defects in the electrolyte that would have otherwise been formed by carbonization. The resultant laser-welded capacitor is therefore characterized by such performance characteristics as relatively low ESR and low leakage currents.

Journal ArticleDOI
TL;DR: In this paper, a stable dielectric layer between the high-κ dielectrics and the electrodes is introduced to prevent oxygen vacancy formation at interfaces, which enables the strong reduction of current instabilities while maintaining good electrical performances.
Abstract: Current instability in metal-oxide-semiconductor and metal-insulator-metal (MIM) capacitors has been previously reported to be a potential reliability issue. This letter intends to study a particular way to reduce these current instabilities with time in high-κ MIM capacitors. It consists in the introduction of a stable dielectric layer between the high-κ dielectric and the electrodes in order to prevent oxygen vacancy formation at interfaces. When applied to Ta2O5 capacitors, the deposition of a thin layer of Al2O3 in the range of a few tens of angstroms enables the strong reduction of current instabilities while maintaining good electrical performances.

Patent
05 Sep 2007
TL;DR: An electric double layer capacitor (EDLC) as discussed by the authors is a type of capacitance with low equivalent series resistance (ESR) in a coin or button cell configuration having low ESR, which comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors.
Abstract: An electric double layer capacitor (EDLC) in a coin or button cell configuration having low equivalent series resistance (ESR). The capacitor comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors. The mesh is embedded into the surface of the adjacent electrode, thereby reducing the interfacial resistance between the electrode and the current collector, thus reducing the ESR of the capacitor.

Patent
20 Nov 2007
TL;DR: In this article, an electrode for an electric double layer capacitor including a current collector electrode and an active substance carried on the current collector, wherein the active substance is composed of a carbon-based fiber and a conductive polymer fiber formed by the electrospinning method, is provided.
Abstract: An electrode for an electric double layer capacitor including a current collector electrode and an active substance carried on the current collector electrode, wherein the active substance is composed of a carbon-based fiber and a conductive polymer fiber formed by the electrospinning method, whereby a high capacity capacitor electrode having of a larger specific surface area than a conventional capacitor electrode and an electric double layer capacitor using the same is provided.

Patent
Tomas Karnik1
22 Oct 2007
TL;DR: An electrolytic capacitor that includes an anode body formed from a powder comprising electrically conductive ceramic particles and a non-metallic element in an amount of about 100 parts per million or more is provided in one embodiment of the invention as mentioned in this paper.
Abstract: An electrolytic capacitor that includes an anode body formed from a powder comprising electrically conductive ceramic particles and a non-metallic element in an amount of about 100 parts per million or more is provided in one embodiment of the invention. The non-metallic element has a ground state electron configuration that includes five valence electrons at an energy level of three or more. Examples of such elements include, for instance, phosphorous, arsenic, antimony, and so forth. The capacitor also comprises a dielectric layer overlying the anode body and an electrolyte layer overlying the dielectric layer.

Patent
31 May 2007
TL;DR: In this article, the authors proposed to increase the series resistance of a feed-through capacitor by forming voids in the active and/or ground electrode plates of the capacitance.
Abstract: The self-resonance insertion loss dip of a feedthrough capacitor is reduced or eliminated by raising the equivalent series resistance of the capacitor, thus minimizing the capacitor Q. The equivalent series resistance of the capacitor can be raised by forming voids in the active and/or ground electrode plates of the capacitor. The electrode plates may be formed so as to have a relatively reduced thickness, or a relatively increased thickness. A conductive material having a relatively high resistivity may be used to form the active and/or ground electrode plates of the capacitor. Alternatively, the conductive material forming the electrode plates may have a dielectric material added thereto.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the application of a continuously operating cyclone reactor and the use of niobium(IV) oxide as raw material solved the problem of the highly exothermic reaction within the cyclone reaction within a Niobium pentoxide by the ratio between gas flow rate and powder flow rate.
Abstract: In the last years, a variety of processes respectively process steps have been investigated for the production of niobium powder. This is due to the fact that niobium capacitors could be a viable alternative to tantalum capacitors from a performance, availability, and price point of view. The reduction of niobium pentoxide by magnesium results in fine powders with high specific surface area but has the disadvantages of a very exothermic nature and the formation of magnesium niobate. It is shown in this work that the application of a continuously operating cyclone reactor and the use of niobium(IV) oxide as raw material solve these problems. A good control of the highly exothermic reaction within the cyclone reactor was achieved in the cyclone reactor by the ratio between gas flow rate and powder flow rate as well as by a proper preheating of the gas.

Patent
Biler Martin1
21 Mar 2007
TL;DR: In this article, an electrolytic capacitor containing an anode and solid electrolyte overlying the anode is provided, and a barrier layer is added to protect the capacitor from its working environment.
Abstract: An electrolytic capacitor containing an anode and solid electrolyte overlying the anode is provided. The capacitor may also include a barrier layer that overlies the solid electrolyte to help protect the capacitor from its working environment. More specifically, the barrier layer may include a three-dimensional crosslinked network that provides excellent adhesion to the underlying layers, and also improved barrier properties to moisture. In this manner, the barrier layer can enable the electrolytic capacitor to increase it performance in relatively high humidity and/or high temperature environments.

Proceedings ArticleDOI
01 Nov 2007
TL;DR: In this article, an economic and automatic experimental technique that allows the determination of the equivalent circuit of aluminum electrolytic capacitors is presented, where the capacitor under test in series with a resistor and connected to a sinusoidal voltage is used to compute the capacitors equivalent circuit.
Abstract: This paper presents an economic and automatic experimental technique that allows the determination of the equivalent circuit of aluminum electrolytic capacitors To implement the proposed technique it is necessary to arrange experimentally the capacitor under test in series with a resistor and connected to a sinusoidal voltage The relationship between gain and phase of the sinusoidal voltage waveform applied to both capacitor and resistor, and the gain and phase of capacitor voltage give enough information to compute the capacitors equivalent circuit To obtain both gain and phase of both waveforms with high accuracy, the discrete Fourier transform algorithm is used

Patent
25 Sep 2007
TL;DR: In this article, a low-height capacitor device is proposed to prevent deterioration of the dielectric layer of the capacitance by using a sealed capacitor element through a space of exposed part.
Abstract: The present invention relates to a small, low-height capacitor device in which deterioration of characteristics such as leakage current is reduced. The capacitor device includes a supporting substrate 1 ; at least one capacitor element 21 disposed on the supporting substrate 1 , including a dielectric layer 4 and a pair of electrodes 2 and 5 sandwiching the dielectric layer 4 ; and a sealant that seals the capacitor element 21 through a space 22 . The dielectric layer 4 has an exposed part 23 exposed in the space 22 . According to this structure, deterioration of the dielectric layer can be prevented, and a capacitor device exhibiting a good leakage current characteristic is obtained.

Patent
02 Oct 2007
TL;DR: In this article, a thin film capacitor including a substrate, a capacitor portion having an upper conductor, a lower conductor and a dielectric thin film, and a resin protective layer for protecting the capacitor portion is interposed between the capacitor component and the resin barrier layer.
Abstract: A thin film capacitor including a substrate, a capacitor portion having an upper conductor, a lower conductor, and a dielectric thin film, and a resin protective layer for protecting the capacitor portion. A barrier layer is interposed between the capacitor portion and the resin protective layer. The barrier layer includes a crystalline dielectric barrier layer formed in contact with the capacitor portion and having the same composition system as the dielectric thin film, and an amorphous inorganic barrier layer formed on the surface of the crystalline dielectric barrier layer and composed of silicon nitride having non-conductivity. The inorganic barrier layer prevents deterioration in the properties of the dielectric thin film by blocking diffusion of the constituent elements of the inorganic barrier layer toward the capacitor portion.

Patent
Jong-Cheol Lee1, Ki-Vin Im, Hoon-Sang Choi, Eun-ae Chung, Sang-Yeol Kang 
11 Apr 2007
TL;DR: In this article, a capacitor includes a first electrode having a conductive pattern and an anti-oxidation pattern contacting the conductive patterns and a second electrode overlapping the first electrode.
Abstract: A capacitor includes a first electrode having a conductive pattern and an anti-oxidation pattern contacting the conductive pattern and a second electrode overlapping the first electrode. The capacitor further includes a capacitor dielectric layer disposed between the first and second electrodes, and having a blanket dielectric layer and a partial dielectric layer. The blanket dielectric layer is disposed between the first and second electrodes, and the partial dielectric layer is disposed between the blanket dielectric layer and the anti-oxidation pattern.

Patent
Kaoru Nagata1, Tetsuo Nanno1
21 Nov 2007
TL;DR: In this article, an all-solid-state electric double layer capacitor comprising a solid electrolyte and a current collector was proposed, where the inorganic solid electrolytes were used to ensure high heat resistance and low process cost.
Abstract: Disclosed is an all-solid-state electric double layer capacitor comprising a solid electrolyte and a current collector, wherein the solid electrolyte is an inorganic solid electrolyte. Such a capacitor has high capacity and is free from any fear of leakage of an electrolytic solution, and also ensures high heat resistance and enables a low process cost.

Journal ArticleDOI
TL;DR: In this paper, the authors describe the fabrication process of three-layer tantalum pentoxide (TaO) dielectric capacitors on silicon wafers for 3D electronic assembly for a DARPA program.
Abstract: High-performance integrated circuits (ICs) require extremely low impedance power distribution. The low voltage, high current requirements of these devices must be provided by decoupling capacitors very close to the IC. Currently this decoupling is provided by discrete surface mount capacitors with relatively high parasitic inductance, requiring many devices in parallel to provide low impedance at high frequencies. Thin film, large area tantalum pentoxide (TaO) dielectric capacitors exhibit very low parasitic inductance, but have been limited in capacitance density to 100nF/cm for single layer devices. Multilayer thin film capacitors can substantially increase the available capacitance. These multilayer thin film capacitors can be fabricated in a variety of ways, allowing them to be embedded between FR-4 layers, under ICs, or even embedded in IC packages. We previously described the initial results of two-layer capacitors fabricated on silicon . These devices had two dielectric layers and three copper plates. Recently we extended the technology to three dielectric layers, and fabricated devices with dielectrics as thin as 1000, to yield a total capacitance density of 0.6F/cm. Capacitors were fabricated on silicon wafers by sputtering a metal plate topped with tantalum, and then wet anodizing the tantalum layer. The process was repeated to create a multilayer stack. The stack was then patterned from top to bottom by successive lithographic and etching steps. This paper will describe the fabrication process in detail. Detailed electrical properties for the resulting two and three layer devices, such as capacitance density, leakage current, breakdown voltage, and impedance will be presented. Using the three-layer process, we fabricated devices for inclusion in a 3-D electronic assembly for a DARPA program, and these devices will be described. Screening and test methods to ensure device reliability will be briefly discussed.

Journal ArticleDOI
TL;DR: In this article, the effect of compressive mechanical stresses on chip solid tantalum capacitors was investigated by monitoring the characteristics of different part types under axial and hydrostatic stresses.
Abstract: The effect of compressive mechanical stresses on chip solid tantalum capacitors is investigated by monitoring the characteristics of different part types under axial and hydrostatic stresses. An exponential increase of leakage currents was observed when stresses exceeded a critical value, which varied on average from 10 to 40 MPa depending on the part type. For the first time, reversible variations of leakage currents (up to two orders of magnitude) with stress have been demonstrated. Mechanical stresses did not cause significant changes of ac characteristics of the capacitors, whereas breakdown voltages measured during the surge-current testing decreased substantially, indicating an increased probability of failures of stressed capacitors in low-impedance applications. Variations of leakage currents are explained by a combination of two mechanisms: stress-induced scintillations and stress-induced generation of electron traps in the tantalum pentoxide dielectric.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the conduction mechanisms in tantalum pentoxide MIM capacitors with four dielectric thicknesses from 200 to 900 A in the 223-323K (-50 ^oC/+50 ^OC) range and found that the leakage current behavior of the capacitor was Space Charge Limited.