Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaishi

Nobuaki Teraguchi

Masanori Murakami

Yoshitaka Tomomura

Yasuo Koide

Nobuyuki Ito

Hiroshi Iwata

Akihide Shibata

Takeshi Kamikawa

Atsushi Ogawa

Akira Suzuki

Geoffrey Duggan

Yushi Inoue

Kohichiroh Adachi

Daisuke Honda

Keiji Watanabe

Judy Megan Rorison

Masayuki Hoteida

Masakazu Matsubayashi

Takuya Sato

Haruhiko Matsukasa

A configuration of a display device capable of color display is obtained. The display device includes a plurality of rod-shaped light-emitting elements each of which includes a semiconductor and which emit light beams having wavelength distributions different from each other, and alignment electrodes (). The alignment electrodes () include a first electrode pair (), a second electrode pair (), and a third electrode pair (). The plurality of rod-shaped light-emitting elements include a first rod-shaped light-emitting element, which is arranged so that one end of the first rod-shaped light-emitting element is adjacent to one electrode of the first electrode pair while the other end is adjacent to the other electrode of the first electrode pair, a second rod-shaped light-emitting element, which is arranged so that one end of the second rod-shaped light-emitting element is adjacent to one electrode of the second electrode pair while the other end of the second rod-shaped light-emitting element is adjacent to the other electrode of the second electrode pair, and a third rod-shaped light-emitting element, which is arranged so that one end of the third rod-shaped light-emitting element is adjacent to one electrode of the third electrode pair while the other end of the third rod-shaped light-emitting element is adjacent to the other electrode of the third electrode pair. Lengths Rto Rof the first to third rod-shaped light-emitting elements and distances dto dof the first to third electrode pairs () to () satisfy the following relationships. d&#x2264;R&#x3c;d, d&#x2264;R&#x3c;d, d&#x2264;R.

Display device and method of producing display device

According to this GaN-based HFET, resistivity &#x3c1; of a semi-insulating film forming a gate insulating film is 3.9&#xd7;10&#x3a9;cm. The value of this resistivity &#x3c1; is a value derived when the current density is 6.25&#xd7;10(A/cm). By inclusion of the gate insulating film by a semi-insulating film having a resistivity &#x3c1;=3.9&#xd7;10&#x3a9;cm, a withstand voltage of 1000 V can be obtained. Meanwhile, the withstand voltage abruptly drops as the resistivity of the gate insulating film exceeds 1 &#xd7;10&#x3a9;cm, and the gate leak current increases when the resistivity of the gate insulating film drops below 1 &#xd7;10&#x3a9;cm.

Nitride semiconductor

An epitaxial wafer for a heterojunction type FET includes an AlN primary layer, a stepwisely composition-graded buffer layer structure, a superlattice buffer layer structure, a GaN channel layer, and a nitride semiconductor electron supply layer, which are sequentially provided on a Si substrate, the stepwisely composition-graded buffer layer structure including a plurality of AlGaN buffer layers provided on each other such that an Al composition ratio is sequentially reduced, an uppermost layer thereof having a composition of AlxGa1&#x2212;xN (0&#x3c;x), a plurality of sets of an AlyGa1&#x2212;yN (y&#x2266;1) superlattice constituting layer and an AlzGa1&#x2212;zN (0&#x3c;z&#x3c;y) superlattice constituting layer being provided on each other alternately starting from one of the AlyGa1&#x2212;yN superlattice constituting layer and the AlzGa1&#x2212;zN superlattice constituting layer in the superlattice buffer layer structure, the AlxGa1&#x2212;xN buffer layer and the AlzGa1&#x2212;zN superlattice constituting layer satisfying x&#x2212;0.05&#x2266;z&#x2266;x+0.05.

Epitaxial wafer for heterojunction type field effect transistor

There is provided a hetero junction field effect transistor including: a first layer of a nitride based, group III-V compound semiconductor; a second layer of a nitride based, group III-V compound semiconductor containing a rare earth element, overlying the first layer; a pair of third layers of a nitride based, group III-V compound semiconductor, overlying the second layer, the third layers being spaced from each other; a gate electrode disposed between the third layers at least a region of the second layer; and a source electrode overlying one of the third layers and a drain electrode overlying an other of the third layers. A method of fabricating the hetero junction field effect transistor is also provided.

Hetero junction field effect transistor and method of fabricating the same

A nitride-based group III-V compound semiconductor device includes a buffer layer, a first nitride semiconductor layer and a second nitride semiconductor layer successively stacked on a substrate, the first and the second nitride layers having their respective lattice constants aand ain the relation a&#x3e;a, an ohmic source electrode and an ohmic drain electrode formed on the second nitride layer, and a piezoelectric effect film formed on at least a partial region between the electrodes, wherein the piezoelectric film exerts compressive stress of an absolute magnitude at least equivalent to that of tensile stress applied to the second nitride layer due to the difference (a&#x2212;a) between the lattice constants of the first and second nitride layers.

Field-effect transistor

A field-effect transistor is provided which includes: a first nitride semiconductor layer having a lattice constant aand a bandgap Eg; a second nitride semiconductor layer stacked on the first nitride semiconductor layer and having a lattice constant aand a bandgap Eg; a source electrode and a drain electrode formed on the second nitride semiconductor layer; a piezo-effect film formed on the second nitride semiconductor layer in a region between the source electrode and the drain electrode; and a gate electrode formed on a region of the piezo-effect film. The relation between the lattice constants aand ais a&#x3e;a. The relation between the bandgaps Egand Egis Eg&#x3c;Eg. The residual polarization density at that surface of the piezo-effect film which faces the second nitride semiconductor layer is equal to or higher than the density of electric charges of a two-dimensional electron gas layer at an interface between the first nitride semiconductor layer and the second nitride semiconductor layer, and negative charges are polarized at that surface of the piezo-effect film which faces the second nitride semiconductor layer.

An electrode employing a nitride-based semiconductor of III&#x2013;V group compound having a favorable ohmic characteristic and a producing method thereof are provided. The electrode includes a nitride-based semiconductor layer of III&#x2013;V group compound, an electrode metal, and a metal oxide inserted therebetween. The metal oxide is preferably an oxide of metal element(s) permitting formation of a nitride semiconductor.

Electrode employing nitride-based semiconductor of III-V group compound, and producing method thereof

In an electrode structure for a nitride III-V compound semiconductor device, a metallic nitride is used as an electrode material. A metallic material of the metallic nitride has a negative nitride formation free energy, and comprises at least one metal selected from a group consisting of IVa-group metals such as titanium and zirconium, Va-group metals such as vanadium, niobium, and tantalum, and VIa-group metals such as chromium, molybdenum, and tungsten.

Electrode structure for nitride III-V compound semiconductor devices

The electrode structure of the invention includes a p-type Al Ga In N (0&lE;x&lE;1, 0&lE;y&lE;1, x&plus;y&lE;1) semiconductor layer and an electrode layer formed on the semiconductor layer. In the electrode structure, the electrode layer contains a mixture of a metal nitride and a metal hydride.

Methods for fabricating an electrode structure

Each layer of a three-layer structure composed of semiconductor (collector layer )/metal (base layer )/semiconductor (emitter layer ) is formed from a nitride. By so doing, one identical constituent element (N) is contained in both semiconductor layers and the metal layer. Because Nb of the NbN base layer combines with N to form a nitride at a stoichiometric ratio of 1:1, the resulting metal nitride and nitride semiconductor exhibit the same stoichiometric ratio. Therefore, it becomes possible to form the base layer and the emitter layer spatially continuously (interface bonding of 1:1), so that a successful Schottky junction can be obtained. As a result, an MBT superior in electrical characteristics can be obtained. Thus, the semiconductor device has successful Schottky characteristics so that superior characteristics can be obtained.

Semiconductor device having successful schottky characteristics

The electrode structure of the invention includes a p-type Al,Ga,In,N (0&lE;x&lE;1, 0&lE;y&lE;1, x&plus;y&lE;1) semiconductor layer and an electrode layer formed on the semiconductor layer. In the electrode structure, the electrode layer contains a mixture of a metal nitride and a metal hydride.

Electrode structure and method for fabricating the same

A group III-V type nitride compound semiconductor device with superior characteristics and a method of readily manufacturing the same are provided. The group III-V type nitride compound semiconductor device has a metal nitride layer, an n-type contact layer, an n-type clad layer, a light emitting layer, a p-type clad layer and a p-type contact layer successively formed on an insulating substrate which has an opening in which an n-type electrode,is formed in contact with the metal nitride layer. A p-type electrode,is formed on the p-type contact layer,. The area of the electrode closer to the substrate can be increased without degrading the mechanical strength of the substrate, and the operating voltage of the semiconductor device can thus be reduced.

Group III-V type nitride compound semiconductor device and method of manufacturing the same

A nitride-type III-V group compound semiconductor device includes a substrate and a layered structure including at least a channel layer using two-dimensional electron gas formed over a substrate, wherein the channel layer contains InN.

Nitride-type III-V HEMT having an InN 2DEG channel layer

A group III-V type nitride semiconductor device includes a substrate with a crystal structure of rutile type, CaC.sub.2 type, rock salt type, spinel type, NaFeO.sub.2 (II) type or LiAlO.sub.2 (I) type, and a nitride semiconductor layer epitaxially grown thereon. The substrate is selected so that its lattice constant allows good lattice match with respect to the nitride semiconductor layer, or the substrate is adjusted in composition to have such a lattice constant.

Growing community of inventors

Nara, Japan

Nobuaki Teraguchi