Japan Science and Technology Agency

Canon Kabushiki Kaisha

Tokyo Institute of Technology

Japan Science and Technology Corporation

Tokyo Institute of Tech

Hiromichi Ota

Hideo Hosono

Masahiro Hirano

Toshio Kamiya

Kenji Nomura

Masahiro Orita

Kazushige Ueda

Hidenori Hiramatsu

Kenichi Kawamura

Nobuhiko Sarukura

Msahiro Hirano

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/cm, and a thin film transistor using such an amorphous oxide. In a thin film transistor having a source electrode, a drain electrode, a gate electrode, a gate insulating film, and a channel layer, an amorphous oxide having an electron carrier concentration less than 10/cmis used in the channel layer

Amorphous oxide and thin film transistor

A switching element of LCDs or organic EL displays which uses a thin film transistor device, includes: a drain electrode, a source electrode, a channel layer contacting the drain electrode and the source electrode, wherein the channel layer comprises indium-gallium-zinc oxide having a transparent, amorphous state of a composition equivalent to InGaO(ZnO)(wherein m is a natural number less than 6) in a crystallized state, and the channel layer has a semi-insulating property represented by an electron mobility of more than 1 cm/(V&#xb7;sec) and an electron carrier concentration is less than 10/cm, a gate electrode, and a gate insulating film positioned between the gate electrode and the channel layer.

Switching element

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&#xb0; 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.

LnCuO(S,Se,Te)monocrystalline thin film, its manufacturing method, and optical device or electronic device using the monocrystalline thin film

Disclosed is a natural-superlattice homologous single-crystal thin film, which includes a complex oxide which is epitaxially grown on either one of a ZnO epitaxial thin film formed on a single-crystal substrate, the single-crystal substrate after disappearance of the ZnO epitaxial thin film and a ZnO single crystal. The complex oxide is expressed by the formula: MMO(ZnO), wherein Mis at least one selected from the group consisting of Ga, Fe, Sc, In, Lu, Yb, Tm, Er, Ho and Y, Mis at least one selected from the group consisting of Mn, Fe, Ga, In and Al, and m is a natural number of 1 or more. A natural-superlattice homologous single-crystal thin film formed by depositing the complex oxide and subjecting the obtained layered film to a thermal anneal treatment can be used in optimal devices, electronic devices and X-ray optical devices.

Natural-superlattice homologous single crystal thin film, method for preparation thereof, and device using said single crystal thin film

The present invention provides an ultraviolet-transparent conductive film comprising a GaOcrystal. The film has a transparency in the wavelength range of 240 to 800 nm, or 240 to 400 nm, and an electric conductivity induced by an oxygen deficiency or dopant in the GaOcrystal. The dopant includes at least one element selected from the group consisting of the Sn, Ge, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. The ultraviolet-transparent conductive film is formed through either one of a pulsed-laser deposition method, sputtering method, CVD method and MBE method, under the conditions with a substrate temperature of 600 to 1500&#xb0; C. and an oxygen partial pressure of 0 to 1 Pa.

Ultraviolet-transparent conductive film and process for producing the same

An ultraviolet-light-emitting semiconductor diode comprising an n-type ZnO layer with luminous characteristics formed on a transparent substrate, and a p-type semiconductor layer selected from the group consisting of SrCu O , CuAlO and CuGaO , which is formed on the n-type ZnO layer to provide a p-n junction therebetween. The transparent substrate is preferably a single crystal substrate having atomically flat yttria-stabilized zirconia (YSZ) (III) surface. The n-type ZnO layer is formed on the transparent substrate having a temperature of 200 to 1200&deg; C., and the p-type semiconductor layer selected from the group of SrCu O , CuAlO and CuGaO is formed on the n-type ZnO layer. The n-type ZnO layer may be formed without heating the substrate, and then the surface of the ZnO layer may be irradiated with ultraviolet light to promote crystallization therein.

Growing community of inventors

Aichi, Japan

Hiromichi Ota