Sony Corporation

Director-general of Agency of Industrial Science and Technology

Shunji Imanaga

Hiroji Kawai

Akira Ishibashi

Hiroyuki Okuyama

Toshimasa Kobayashi

Ichiro Hase

Shoji Kanamaru

Kunio Kaneko

A GaN-type field effect transistor exhibits a large input amplitude by using a gate insulating film. A channel layer and a gate insulating film are sequentially laminated on a substrate with a buffer layer therebetween. A gate electrode is formed on the gate insulating film. A source electrode and a drain electrode are disposed at the both sides of the gate electrode and are electrically connected to the channel layer via openings. The channel layer is formed from n-type GaN. The gate insulating film is made from AlN, which exhibits excellent insulation characteristics, thus increasing the Schottky barrier and achieving a large input amplitude. If the FET is operated in the enhancement mode, it is operable in a manner similar to a Si-MOS-type FET, resulting in the formation of an inversion layer.

Method for manufacturing field effect transistor

A heterojunction field effect transistor realizing a high performance by a significant decrease. in source resistance while maintaining a sufficiently high gate resistivity to voltage is provided. Sequentially stacked on a c-face sapphire substrate via a buffer layer are an undoped GaN layer, undoped Al.sub.0.3 Ga.sub.07 N layer, undoped GaN channel layer, undoped Al.sub.0.15 Ga.sub.0.85 N spacer layer, n-type Al.sub.0.15 Ga.sub.0.85 N electron supply layer, graded undoped Al.sub.z Ga.sub.1-z N barrier layer and n-type Al.sub.0.06 Ga.sub.0.94 N contact layer, and a gate electrode, source electrode and drain electrode are formed on the n-type Al.sub.0.06 Ga.sub.0.94 N contact layer to form a AlGaN/GaN HEMT. The Al composition z in the graded undoped Al.sub.z Ga.sub.1-z N barrier layer continuously decreases from 0.15 to 0.06, for example, from the n-type Al.sub.0.15 Ga.sub.0.85 N electron supply layer toward the n-type Al.sub.0.06 Ga.sub.0.94 N contact layer. An n.sup.++ -type GaN contact layer may be formed on the n-type Al.sub.0.06 Ga.sub.0.94 N contact layer in the region for the source electrode and the drain electrode, and the source electrode and the drain may be formed on it.

Heterojunction field effect transistor

Field effect transistor with nitride compound

A semiconductor laser using II-VI compound semiconductors and capable of emitting blue to ultraviolet light is disclosed. The semiconductor laser is configured to sandwich an active layer made of a Zn.sub.x Mg.sub.1-x S.sub.y Se.sub.1-y compound semiconductor where 0.ltoreq.x&lt;1 and 0.ltoreq.y.ltoreq.1 excluding ranges of 1.2y-2.2x.gtoreq.1, 1.3y-3.9x.gtoreq.1, x.gtoreq.0, and y.ltoreq.1 by an n-type cladding layer and a p-type cladding layer from opposite sides.

Semiconductor laser

A III-V semiconductor device is disclosed, which includes an emitter region, an emitter barrier region having such a barrier height as to substantially restrict a thermionic emission current as compared with a tunneling current and such a barrier width as to permit the tunneling current, a base region containing indium and having higher electron affinity than said emitter region and a collector barrier region having such a barrier height as to substantially prohibit a thermally distributed electron from overflowing and such a barrier width as to substantially prohibit the tunneling current.

Growing community of inventors

Kanagawa, Japan

Shunji Imanaga