Matsushita Electric Works, Ltd.

Takashi Hatai

Takuya Komoda

Yoshiaki Honda

Yoshifumi Watabe

Tsutomu Ichihara

Koichi Aizawa

Toru Baba

Nobuyoshi Koshida

Yoshiyuki Takegawa

Yukihiro Kondo

Hiroshi Fukshima

Shigekazu Kusanagi

Naomasa Oka

Hiroaki Kitamura

Naoki Kumon

Harue Kawagoe

Shoichi Morii

Masanori Fukui

Kenji Koi

Noriyoshi Nakaoka

Hiroshi Kano

Shin Matsugi

Chousei Hamada

Koshi Akedo

An infrared radiation element A heat insulating layer having sufficiently smaller thermal conductivity than a semiconductor substrate, is formed on a surface in the thickness direction of the semiconductor substrate. A heating layer, which is in the form of a lamina (plane) and has larger thermal conductivity and larger electrical conductivity than the heat insulating layer, is formed on the heat insulating layer. A pair of padsfor energization are formed on the heating layer. The semiconductor substrate is made of a silicon substrate. The heat insulating layer and the heating layer are formed by porous silicon layers having different porosities from each other, and the heating layer has smaller porosity than the heat insulating layer. By using the infrared radiation element as an infrared radiation source of a gas sensor, it becomes possible to extend a life of the infrared radiation source.

Infrared radiation element and gas sensor using it

In a field emission-type electron source (), a strong field drift layer () and a surface electrode () consisting of a gold thin film are provided on an n-type silicon substrate (). An ohmic electrode () is provided on the back surface of the n-type silicon substrate (). A direct current voltage is applied so that the surface electrode () becomes positive in potential relevant to the ohmic electrode (). In this manner, electrons injected from the ohmic electrode () into the strong field drift layer () via the n-type silicon substrate () drift in the strong field drift layer (), and is emitted to the outside via the surface electrode (). The strong field drift layer () has: a number of semiconductor nanocrystals () of nano-meter order formed partly of a semiconductor layer configuring the strong field drift layer (); and a number of insulating films () each of which is formed on the surface of each of the semiconductor nanocrystals () and each having film thickness to an extent such that an electron tunneling phenomenon occurs.

Field emission electron source and production method thereof

Disclosed is a method for the electrochemical oxidation of a semiconductor layer. In an electrochemical oxidation treatment for the production process of an electron source (field-emission type electron source) as one of electronic devices, a control section determines a voltage increment due to the resistance of an electrolytic solution B in advance, based on a detected voltage from a resistance detect section . Then, the control section controls a current source to supply a constant current so as to initiate an oxidation treatment for a semiconductor layer formed on an object . The control section corrects a detected voltage from a voltage detect section by subtracting the voltage increment therefrom. When the corrected voltage reaches a given upper voltage value, the control section is operable to discontinue the output of the current source and terminate the oxidation treatment. The present invention allows electronic devices to be produced with reduced variation in the characteristics thereof.

Method for electrochemical oxidation

An array of field emission electron sources and a method of preparing the array which discharges electrons from desired regions of a surface electrode of field emission electron sources. The field emission electron source comprises an electrically conductive substrate of p-type silicon substrate ; n-type regions of stripes of diffusion layers on one of principal surfaces of the p-type silicon substrate, strong electric field drift layers formed on the n-type regions which is made of oxidized porous poly-silicon for drifting electrons injected from the n-type region ; poly-silicon layers between the strong field drift layers ; surface electrodes of the stripes of thin conductive film formed in a manner to cross over the stripes of the strong field drift layer and the poly-silicon layers . By selecting a pair of the n-type regions and the surface electrodes and thereby making electron emitted from the crossing points due to combination of the surface electrode to be electrically applied and the n-type region to be electrically applied, electrons can be discharged from desired regions of the surface electrodes

Field emission electron source, method of producing the same, and use of the same

An electron source ( ) has an electron source element ( ) including a lower electrode ( ), a drift layer ( ) and a surface electrode ( ). The drift layer ( ) is interposed between the lower electrode ( ) and the surface electrode ( ). When a certain voltage is applied between the surface electrode ( ) and the lower electrode ( ) such that the surface electrode ( ) has a higher potential than that of the lower electrode ( ), a resultingly induced electric field allows electrons to pass through the drift layer ( ) and then the electrons are emitted through the surface electrode ( ). When a forward-bias voltage is applied between the surface electrode ( ) and the lower electrode ( ), a reverse-bias voltage is applied after the forward-bias voltage has been applied to release out of the drift layer ( ) an electron captured by a trap ( ) in the drift layer ( ).

Field emission-type electron source and method of biasing the same

A field emission-type electron source includes an insulative substrate in the form of a glass substrate having an electroconductive layer formed thereon. A strong electrical field drift layer in the form of an oxidized porous polycrystalline silicon layer is formed over the electroconductive layer . This electroconductive layer includes a lower electroconductive film , made of copper and formed on the insulative substrate , and an upper electroconductive film made of aluminum and formed over the electroconductive film . The strong electrical field drift layer is formed by forming a polycrystalline silicon layer on the electroconductive layer , rendering the polycrystalline silicon layer to be porous and finally oxidizing it. The upper electroconductive film has a property that reacts easily with silicon and, therefore, formation of an amorphous layer which would occur during formation of the polycrystalline silicon layer can be suppressed.

Field emission-type electron source and manufacturing method thereof

An electron source has an n-type silicon substrate , a drift layer formed on one surface of the substrate , and a surface electrode formed on the drift layer . A voltage is applied so that the surface electrode becomes positive in polarity relevant to the substrate , whereby electrons injected from the substrate into the drift layer drift within the drift layer , and are emitted through the surface electrode . In a process for manufacturing this electron source , when the drift layer is formed, a porous semiconductor layer containing a semiconductor nanocrystal is formed in accordance with anodic oxidation. Then, an insulating film is formed on the surface of each semiconductor nanocrystal. Anodic oxidation is carried out while emitting light that essentially contains a wavelength in a visible light region relevant to the semiconductor layer.

Method of and apparatus for manufacturing field emission-type electron source

A lower electrode ( ) and surface electrode ( ) composed of a layer-structured conductive carbide layer is formed on one principal surface side of the substrate ( ) composed of an insulative substrate such as a glass or ceramic substrate. A non-doped polycrystalline silicon layer ( ) is formed on the lower electrode ( ). An electron transit layer ( ) composed of an oxidized porous polycrystalline silicon is formed on the polycrystalline silicon layer ( ). The electron transit layer ( ) is composed of a composite nanocrystal layer including polycrystalline silicon and many nanocrystalline silicons residing adjacent to a grain boundary of the polycrystalline silicon. When voltage is applied between the lower electrode ( ) and the surface electrode ( ) such that the surface electrode ( ) has a higher potential, electrons are injected from the lower electrode ( ) toward the surface electrode ( ), and emitted through the surface electrode ( ) through the electron transit layer ( ).

Field emission-type electron source

In a field emission-type electron source ( ), lower electrodes ( ) made of an electroconductive layer, a strong field drift layer ( ) including drift portions ( ) made of an oxidized or nitrided porous semiconductor, and surface electrodes ( ) made of a metal layer are provided on an upper side of a dielectric substrate ( ) made of glass. When voltage is applied to cause the surface electrodes ( ) to be anodic with respect to the lower electrodes ( ), electrons injected from the lower electrodes ( ) to the strong field drift layer ( ) are led to drift through the strong field drift layer ( ) and are emitted outside through the surface electrodes ( ). A pn-junction semiconductor layer composed of an n-layer ( ) and a p-layer ( ) is provided between the lower electrode ( ) and the strong field drift layer ( ) to prevent a leakage current from flowing to the surface electrode ( ) from the lower electrode ( ), thereby reducing amount of power consumption.

Field emission type electron source

An electron source ( ) is provided with an n-type silicon substrate ( ) as a conductive substrate, a drift layer ( ) composed of oxidized porous polycrystalline silicon which is formed on the main surface of the silicon substrate ( ), and a surface electrode ( ) as a conductive thin film formed on the drift layer ( ). The process for, forming the surface electrode ( ) includes the steps of forming a first layer composed of Cr on the drift layer ( ), forming a second layer composed of Au on the first layer, and alloying the two layers. The surface electrode ( ) has higher adhesion for the drift layer and/or stability for the lapse of time. In addition, the surface electrode ( ) has lower density of states in an energy region near energy of emitted electrons, in comparison with the simple substance of Cr. In the surface electrode ( ), scattering of the electrons is less so that electron emitting efficiency is higher.

A field emission-type electron source ( ) is provided with a conductive substrate ( ), a semiconductor layer formed on a surface of the conductive substrate ( ), at least a part of the semiconductor layer being made porous, and a conductive thin film ( ) formed on the semiconductor layer. Electrons injected into the conductive substrate ( ) are emitted from the conductive thin film ( ) through the semiconductor layer by applying a voltage between the conductive thin film ( ) and the conductive substrate ( ) in such a manner that the conductive thin film ( ) acts as a positive electrode against the conductive substrate ( ). The semiconductor layer includes a porous semiconductor layer ( ) in which columnar structures ( ) and porous structures ( ) composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film ( ). Further, an average dimension of each of the porous structures ( ) in a thickness direction of the semiconductor layer is smaller than or equal to 2 &mgr;m.

A field emission type electron source,is provided with an n-type silicon substrate,a strong field drift layer,formed on the n-type silicon substrate,directly or inserting a polycrystalline silicon layer,therebetween, and an electrically conductive thin film,which is a thin gold film, formed on the strong field drift layer,Further, an ohmic electrode,is provided on the back surface of the n-type silicon substrate,Hereupon, electrons, which are injected from the n-type silicon substrate,into the strong field drift layer,drift in the strong field drift layer,toward the surface of the layer, and then pass through the electrically conductive thin film,to be emitted outward. The strong field drift layer,is formed by making the polycrystalline silicon,formed on the n-type silicon substrate,porous by means of an anodic oxidation, and further oxidizing it using dilute nitric acid or the like.

Field emission-type electron source and manufacturing method thereof and display using the electron source

A carbonate spring bath system creates a bath water dissolved with CO.sub.2 gas and supplies the same to a bathtub. The system includes a source of a concentrated CO.sub.2 gas, a circulation path connected to the bathtub and including a booster pump for circulating a bath water from and into the bathtub. CO.sub.2 gas and air supply lines are connected to the circulation path upstream of the pump. The CO.sub.2 gas and air supply lines includes valves which are opened and closed to provide the CO.sub.2 gas and the air at a suitable mixture ratio such that the CO.sub.2 gas and air are forced to dissolve in the pressurized bath water. Disposed downstream of the pump is an accumulator for separating undissolved gas in the bath water and storing in a gas chamber the undissolved gas emanating from the bath water. A recycle line connects the gas chamber to the circulation path upstream of the pump to return the undissolved gas to the circulation path. An exhaust line is connected to the gas chamber for exhausting the undissolved gas outwardly. The recycle and exhaust lines are provided respectively with valves which are controlled to open and close such that the system can selectively operates a recycle mode and an exhaust mode.

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Neyagawa, Japan

Takashi Hatai