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Author

Hiromichi Ota

Other affiliations: Hoya Corporation
Bio: Hiromichi Ota is an academic researcher from Canon Inc.. The author has contributed to research in topics: Thin film & Layer (electronics). The author has an hindex of 12, co-authored 36 publications receiving 5683 citations. Previous affiliations of Hiromichi Ota include Hoya Corporation.

Papers
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Patent
28 Feb 2005
TL;DR: In this paper, an amorphous oxide and a thin-film transistor were constructed using an electron carrier concentration less than 10 18 /cm 3, where the electron carrier was obtained by using a gate electrode and gate insulating film.
Abstract: The present invention relates to an amorphous oxide and a thin film transistor using the amorphous oxide. In particular, the present invention provides an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 , and a thin film transistor using such an amorphous oxide. In a thin film transistor having a source electrode 6 , a drain electrode 5 , a gate electrode 4 , a gate insulating film 3 , and a channel layer 2 , an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 is used in the channel layer 2.

1,214 citations

Patent
31 Oct 2002
TL;DR: A natural superlattice homologous single crystal thin film, characterized in that it comprises a composite oxide which is represented by the formula M1M2O3(ZnO)m, is a natural number of 1 or more as discussed by the authors.
Abstract: A natural superlattice homologous single crystal thin film, characterized in that it comprises a composite oxide which is represented by the formula M1M2O3(ZnO)m, wherein M1 is at least one of Ga, Fe, Sc, In, Lu, Yb, Tm, Er, Ho and Y, M2 is at least one of Mn, Fe, Ga, In and Al, and m is a natural number of 1 or more, and has been grown epitaxially on an epitaxial thin film formed on a single crystal substrate, or on said single crystal substrate from which said epitaxial thin film has disappeared, or on a ZnO single crystal; a method for preparing the natural superlattice thin film which comprises depositing the composite oxide, and diffusing the resultant laminated film by heating it. The natural superlattice homologous single crystal thin film is suitably used in an optical device, an electronic device, an X-ray optical device and the like.

1,090 citations

Patent
11 Sep 2002
TL;DR: In this paper, the authors used a homologous compound single crystal InMO 3 (ZnO) m (M=In, Fe, Ga, or Al; m=an integer of 1 to 49) thin film as an active layer to construct a transparent thin film field effect type transistor having a good switching characteristic.
Abstract: PROBLEM TO BE SOLVED: To solve the problem that in ZnO as a transparent oxide semiconductor, it is difficult to reduce an electric conductivity and it is impossible to constitute a normally off field effect type transistor, or as it is difficult to form an amorphous state, an amorphous transistor adaptive for a large area cannot be manufactured. SOLUTION: In a homologous compound InMO 3 (ZnO) m (M=In, Fe, Ga or Al; m=an integer of 1 to 49) single crystal thin film manufactured by a reactive solid-phase epitaxial method, a deviation from a stoichiometry is very small and a good insulator is obtained near room temperatures. By using the homologous compound single crystal InMO 3 (ZnO) m (M=In, Fe, Ga or Al; m=an integer of 1 to 49) thin film as an active layer, a transparent thin film field effect type transistor having a good switching characteristic can be manufactured by a normally off operation. COPYRIGHT: (C)2004,JPO

1,056 citations

Patent
19 Feb 2003
TL;DR: In this paper, a method of growing a base thin film on a single-crystal substrate, depositing an amorphous or polycrystalline LnCuOX thin film, and then annealing the laminated film at a high temperature of 500° C. or more.
Abstract: Disclosed is a method of producing an LnCuOX single-crystal thin film (wherein Ln is at least one selected from the group consisting of lanthanide elements and yttrium, and X is at least one selected from the group consisting of S, Se and Te), which comprises the steps of growing a base thin film on a single-crystal substrate, depositing an amorphous or polycrystalline LnCuOX thin film on the base thin film to form a laminated film, and then annealing the laminated film at a high temperature of 500° C. or more. While a conventional LnCuOX film produced by growing an amorphous film through a sputtering process under appropriate conditions and then annealing the film at a high temperature was unexceptionally a polycrystalline substance incapable of achieving high emission efficiency and electron mobility required for a material of light-emitting devices or electronic devices, the method of the present invention can grow a thin film with excellent crystallinity suitable as a single crystal to an building black of light-emitting diodes, semiconductor leasers, filed-effect transistors, or a hetero-bipolar transistors.

1,027 citations

Patent
24 Jul 1998
TL;DR: In this paper, an oxide expressed by the general formula of ZnxMyInzO(x+3y/2+3z/2) is used as a target to form an oxide film by sputtering or laser ablation method under the conditions of from room temp. to 300 deg.C substrate temp. and 1×10-2 to 10 (Pa) pressure.
Abstract: PROBLEM TO BE SOLVED: To obtain an oxide film having excellent transmitting property for blue light while reducing the amt. of In2O3 which is a scarse mineral resource by using an oxide having a specified compsn. of Zn, Al and Ba, In as a target and specifying the substrate temp. and pressure. SOLUTION: An oxide expressed by the general formula of ZnxMyInzO(x+3y/2+3z/2) is used as a target to form an oxide film by sputtering or laser ablation method under the conditions of from room temp. to 300 deg.C substrate temp. and 1×10-2 to 10 (Pa) pressure. In the formula, M is at least one element of Al and Ga, the proportion x/y ranges 0.2 to 12, the proportion z/y ranges 0.4 to 1.4. The conductivity of the oxide of the target is good when the carrier electron density in the conductive band ranges about 1×1018 to 1×1022/cm3. By injecting actions to the oxide, carrier electrons are injected to the conductive band to develop the conductivity.

1,018 citations


Cited by
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Patent
18 May 2006
TL;DR: In this paper, a light-emitting device with the use of an amorphous oxide was presented, which has a lightemitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an Amorphous.
Abstract: An object of the present invention is to provide a new light-emitting device with the use of an amorphous oxide. The light-emitting device has a light-emitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an amorphous.

1,551 citations

Patent
01 Aug 2008
TL;DR: In this article, the oxide semiconductor film has at least a crystallized region in a channel region, which is defined as a region of interest (ROI) for a semiconductor device.
Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

1,501 citations

Patent
09 Nov 2005
TL;DR: In this paper, a field-effect transistor with an active layer and a gate insulating film is presented, where the active layer includes an amorphous oxide layer and the gate insulator.
Abstract: Provided is a field-effect transistor including an active layer and a gate insulating film, wherein the active layer includes an amorphous oxide layer containing an amorphous region and a crystalline region, and the crystalline region is in the vicinity of or in contact with an interface between the amorphous oxide layer and the gate insulating film

1,320 citations

Patent
28 Feb 2005
TL;DR: In this paper, an amorphous oxide and a thin-film transistor were constructed using an electron carrier concentration less than 10 18 /cm 3, where the electron carrier was obtained by using a gate electrode and gate insulating film.
Abstract: The present invention relates to an amorphous oxide and a thin film transistor using the amorphous oxide. In particular, the present invention provides an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 , and a thin film transistor using such an amorphous oxide. In a thin film transistor having a source electrode 6 , a drain electrode 5 , a gate electrode 4 , a gate insulating film 3 , and a channel layer 2 , an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 is used in the channel layer 2.

1,214 citations

Patent
09 Nov 2005
TL;DR: In this article, a novel amorphous oxide applicable to an active layer of a TFT is provided, which consists of microcrystals and can be applied to any TFT.
Abstract: A novel amorphous oxide applicable, for example, to an active layer of a TFT is provided. The amorphous oxide comprises microcrystals.

1,182 citations