Author
Masahiro Hirano
Other affiliations: Nagoya University, Hoya Corporation
Bio: Masahiro Hirano is an academic researcher from Kyoto University. The author has contributed to research in topics: Thin film & Layer (electronics). The author has an hindex of 17, co-authored 101 publications receiving 4077 citations. Previous affiliations of Masahiro Hirano include Nagoya University & Hoya Corporation.
Topics: Thin film, Layer (electronics), Oxide, Laser, Femtosecond
Papers
More filters
Patent•
28 Feb 2005TL;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•
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
12 Apr 2001
TL;DR: In this paper, the optical properties of common impurities/dopants in synthetic silicas used in laser optics are discussed, including the properties of the color centers contributing to the optical absorption spectrum of synthetic silica glass in near infrared to vacuum UV range.
Abstract: Color centers contributing to the optical absorption spectrum of synthetic silica glass in the near infrared to vacuum UV range are reviewed. Intrinsic defects related to oxygen deficiency are characterized: E'-centers, oxygen vacancies, divalent silicon and defects related to oxygen excess: oxygen dangling bonds, peroxy radicals, interstitial oxygen and ozone molecules. The optical properties of common impurities/dopants in synthetic silicas used in laser optics are discussed.
87 citations
Patent•
12 Feb 2004
TL;DR: In this article, the free oxygen atoms of a mixture of CaO and Al2O3 were substituted with electrons to obtain electride compounds with high electric conductivity at room temperature, which can be regarded as an electride compound having [Ca24Al28O64]4+ or [Sr24Al 28O64]-4+ as cation and electrons as anions.
Abstract: A compound comprising 12CaO·7Al2O3 compound, 12SrO·7Al2O3 compound or a mixed crystal compound containing 12CaO·7Al2O3 and 12SrO·7Al2O3, and electrons introduced in the compound at a high concentration; and a method for preparing the compound comprising the electrons introduced through substituting many free oxygen atoms with electrons, which comprises providing a hydrostatic pressure press formed product of single crystals or a fine powder and holding the formed product in a gaseous alkali metal or alkaline earth metal at about 700°C, or comprises holding a hydrostatic pressure press formed product of a powder at about 1600°C in a carbon crucible, followed by slow cooling, or comprises shooting rare gas ions into a thin film of said compound kept at about 600°C. A compound obtained by substituting all the free oxygen atoms of said compound with electrons can be regarded as an electride compound having [Ca24Al28O64]4+ or [Sr24Al28O64]4+ as a cation and electrons as anions. Conventionally, in a solid solution system of CaO or SrO with Al2O3, a substance exhibiting a high electric conductivity (> 10-4S cm-1) at room temperature has been difficult to prepare.
53 citations
Cited by
More filters
Patent•
18 May 2006TL;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 2005TL;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 2005TL;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 2005TL;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