National Institute of Advanced Industrial Science and Technology

Other

Elpida Memory, Inc.

Rohm Co., Ltd.

Paul Fons

Shigeru Niki

Kakuya Iwata

Ken Nakahara

Akimasa Yamada

Junji Tominaga

Koji Matsubara

Alexander Kolobov

Robert Simpson

Hidemi Takasu

Tetsuhiro Tanabe

Isamu Asano

Takayuki Shima

Kazuo Aizawa

Reiko Kondo

A solid-state memory that requires a lower current during recording and erasing data and can repeatedly rewrite data an increased number of times. In at least one example embodiment, the solid-state memory includes a recording layer that includes a laminated structure in which electric properties are changed in response to a phase separation. The laminated structure includes a film containing an Sb atom(s) and a film containing a Ge atom(s), which films constitute a superlattice structure. In the laminated structure, phase separation of the film containing the Sb atom and the film containing the Ge atom allows data to be recorded and erased efficiently.

Superlattice recording layer for a phase change memory

A method of at least one embodiment of the present invention of manufacturing a solid-state memory is a method of manufacturing a solid-state memory, the solid-state memory including a recording film whose electric characteristics are varied by phase transformation, the method including: forming the recording film by forming a laminate of two or more layers so that a superlattice structure is provided, each of the layers having a parent phase which shows solid-to-solid phase-transformation, the recording film being formed at a temperature not lower than a temperature highest among crystallization temperatures of the parent phases. It is thus possible to manufacture a solid-state memory which requires lower current for recording and erasing data and has a greater rewriting cycle number.

Solid-state memory manufacturing method

A solid memory may include a recording layer including Ge, Sb and Te as major components. The recording layer may include a superlattice. The recording layer may include multi-layers each having a parent phase showing a phase transformation in solid-states, the phase transformation causing change in electrical property of the recording layer. The recording layer may include an SbTelayer that includes at least one period of a first lamination of a first Te-atomic layer, a first Sb-atomic layer, a second Te-atomic layer, a second Sb-atomic layer, and a third Te-atomic layer in these order, a GeTe layer that includes at least one period of a second lamination of a fourth Te-atomic layer and a Ge-atomic layer, and an Sb layer that includes a plurality of Sb-atomic layers.

Solid-state memory and semiconductor device

To include a superlattice laminate having laminated thereon a first crystal layer of which crystal lattice is a cubic crystal and in which positions of constituent atoms are reversibly replaced by application of energy, and a second crystal layer having a composition different from that of the first crystal layer, and an orientation layer that is an underlaying layer of the superlattice laminate and causes a laminated surface of the first crystal layer to be (111)-orientated. According to the present invention, the laminated surface of the first crystal layer can be (111)-orientated by using the orientation layer as an underlaying layer. In the first crystal layer of which laminated surface is (111)-orientated, a crystal structure reversibly changes when a relatively low energy is applied. Therefore, characteristics of a superlattice device having this crystal layer can be enhanced.

Superlattice device, manufacturing method thereof, solid-state memory including superlattice device, data processing system, and data processing device

A solid-state memory device includes: a superlattice laminate having plural crystal layers laminated therein, the crystal layers including first and second crystal layers having mutually opposite compositions; a lower electrode provided on a first surface in a laminating direction of the superlattice laminate; and an upper electrode provided on a second surface of the superlattice laminate in the laminating direction. The first crystal layer included in the superlattice laminate is made of a phase change compound. According to the present invention, the superlattice laminate laminated in opposite directions of the upper and lower electrodes is sandwiched between these electrodes. Therefore, when an electric energy is applied to the superlattice laminate via these electrodes, a uniform electric energy can be applied to a laminated surface of the superlattice laminate. Accordingly, fluctuation of a resistance is small even when information is repeatedly rewritten, and data can be read stably as a result.

Solid-state memory device, data processing system, and data processing device

A light emitting device includes a silicon substrate (), a silicon nitride film () formed on the surface of the silicon substrate (), at least an n-type layer (), () and a p-type layer (), () which are formed on the silicon nitride film () and also which are made of a ZnO based compound semiconductor, and a semiconductor layer lamination () in which layers are laminated to form a light emitting layer. Preferably this silicon nitride film () is formed by thermal treatment conducted in an atmosphere containing nitrogen such as an ammonium gas. Also, in another embodiment, a light emitting device is formed by growing a ZnO based compound semiconductor layer on a main face of a sapphire substrate, the main face being perpendicular to the C-face thereof. As a result, it is possible to obtain a device using a ZnO based compound with high properties such as an LED very excellent in crystallinity and having a high light emitting efficiency.

ZnO based compound semiconductor light emitting device and method for manufacturing the same

A light-emitting device includes a silicon substrate, a ZnOSSe layer provided on the silicon substrate that is lattice-matched to the silicon substrate, and a separate confinement heterostructure light-emitting layer that is provided on the ZnOSSe layer and includes an active layer and upper and lower clad layers.

ZnOSSe compound semiconductor, integrated circuit using the semiconductor and method of manufacturing the semiconductor and the integrated circuit

A light emitting device includes a silicon substrate ( ), a silicon nitride film ( ) formed on the surface of the silicon substrate ( ), at least an n-type layer ( ), ( ) and a p-type layer ( ), ( ) which are formed on the silicon nitride film ( ) and also which are made of a ZnO based compound semiconductor, and a semiconductor layer lamination ( ) in which layers are laminated to form a light emitting layer. Preferably this silicon nitride film ( ) is formed by thermal treatment conducted in an atmosphere containing nitrogen such as an ammonium gas. Also, in another embodiment, a light emitting device is formed by growing a ZnO based compound semiconductor layer on a main face of a sapphire substrate, the main face being perpendicular to the C-face thereof. As a result, it is possible to obtain a device using a ZnO based compound with high properties such as an LED very excellent in crystallinity and having a high light emitting efficiency.

ZnO compound semiconductor light emitting element

In the case in which a ZnO based oxide semiconductor layer is to be hetero-epitaxially grown on a substrate formed of a material which is different from that of a ZnO based oxide semiconductor, the ZnO based oxide semiconductor layer is grown at a high temperature of 500&deg; C. or more, and supply of oxygen is stopped and gradual cooling is carried out until a substrate temperature is lowered to 350&deg; C. or less after the growth of the ZnO based oxide semiconductor layer is completed. As a result, it is possible to suppress the generation of dislocations or crystal defects over an epitaxial grown layer based on the atmosphere while the substrate temperature is lowered after the growth of the semiconductor layer and a difference in a coefficient of thermal expansion, thereby obtaining a semiconductor device having a high quality ZnO based oxide semiconductor layer which has an excellent crystalline property and a semiconductor light emitting device having the high characteristics.

Method of manufacturing semiconductor device having ZnO based oxide semiconductor layer

A ZnO based oxide semiconductor layer is grown on a sapphire substrate by supplying, for example, raw materials made of Zn and O constituting ZnO and a p-type dopant material made of N without supplying an n-type dopant material (a-step). By stopping the supply of the material of O and further supplying an n-type dopant material made of Ga, the semiconductor layer is doped with the p-type dopant and the n-type dopant, thereby forming a p-type ZnO layer ( ) (b-step). By repeating the steps (a) and (b) plural times, a p-type ZnO based oxide semiconductor layer is grown. As a result, N to be the p-type dopant can be doped in a stable carrier concentration also during high temperature growth in which a residual carrier concentration can be reduced, and the carrier concentration of the p-type layer made of the ZnO based oxide semiconductor can be increased sufficiently.

Method of growing p-type ZnO based oxide semiconductor layer and method of manufacturing semiconductor light emitting device

Method of producing Cu (In, Ga) (Se, S) 2 semiconductor film

A substrate such as a sapphire substrate or the like is set to a molecular beam epitaxy (MBE) apparatus. Next, the temperature of the substrate is elevated to the temperature which is lower than the temperature at which a predetermined ZnO based oxide semiconductor layer (i.e. function layer) is grown (S ). Then, raw materials containing oxygen radical is irradiated to the substrate to grow a buffer layer made of ZnO based oxide semiconductor (S ). Subsequently, the irradiation of oxygen radical is stopped so as to eliminate the influence of oxygen onto the buffer layer (S ). Then, the temperature of the substrate is elevated to the temperature at which the predetermined ZnO based oxide semiconductor layer is grown (S ). After that, raw materials containing oxygen radical is irradiated so as to sequentially grow a ZnO based oxide semiconductor layer as a function layer (S ). As a result, a ZnO based oxide semiconductor layer with low concentration of residual carrier can be grown, and a semiconductor light emitting device such as light emitting diode and laser diode with high light emitting characteristics can be obtained.

Method for growing ZnO based oxide semiconductor layer and method for manufacturing semiconductor light emitting device using the same

The closing plates ( ), ( ) are provided on the both end portions of the cylindrical insulator body ( ), the gas introduction tube for introducing a gaseous substance is inserted into one plate ( ) of the closing plates of the plasma chamber ( ) for making the gaseous substance plasmatic within it, and on the other plate ( ), the plasma radiation outlet ( ) is provided. Then, nearby the plasma jet ( ) outgoing from the radiation outlet, the electrode ( ) for applying a high electric field of an ion trapper is provided so as to be opposed to the grounded electrode ( ) interposed the plasma jet between them. This electrode for applying a high electric field is fixed on the grounded metal plate ( ) provided on the other plate ( ) via the insulation porcelain ( ) made of MgO or quartz. As a result, a radical cell device which does not blow-off and mix up Al into the layer epitaxially grown is obtained ,and a Groups II-VI compound semiconductor device because undoped Al is not contained in the semiconductor layers.

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Tsukuba, Japan

Paul Fons