National Institute of Advanced Industrial Science and Technology

Other

Akimasa Yamada

Shigeru Niki

Koji Matsubara

Paul Fons

Kakuya Iwata

Ken Nakahara

Shogo Ishizuka

Keiichiro Sakurai

Hajime Shibata

Hitoshi Tampo

An object of the present invention is to increase the light emission efficiency of a ZnO-based optical semiconductor device. An optical semiconductor device B has a structure which includes n-type ZnMgO (barrier layer)/ZnMgO (active layer)/p-type ZnMgO (barrier layer), and light is emitted from the active layer. Electrodesare respectively formed on barrier layers. By applying a voltage between the two electrodes, light is emitted from ZnO (active layer). Here, there are a relationship of x&#x3c;y and a relationship of x&#x3c;z. For instance, such values as x=0.1, y=0.15 and z=0.16 can be chosen. Otherwise, such values as x=0.15, y=0.25 and z=0.24 can be choose as well. In this case, by increasing the value x of the active layer, it is possible to shift its light emission wavelength to the shorter wavelength side. In addition, as shown in the above-described results, by increasing the value x, it is possible to enhance its light emission efficiency. For this reason, the optical semiconductor device is excellent as a light-emitting device.

Semiconductor device

A method for producing a semiconductor film having a chalcopyrite structure including a Ib group element, a IIIb group element and a VIb group element including selenium, the method including cracking selenium with plasma to generate radical selenium, and using the radical selenium in the process of forming the semiconductor film.

Method and apparatus for producing semiconductor films and related devices

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

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.

Growing community of inventors

Ibaraki, Japan

Akimasa Yamada