Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Yoshitaka Nakano

Tsutomu Uesugi

Tetsu Kachi

Masahiro Sugimoto

Narumasa Soejima

Hiroyuki Ueda

A semiconductor device has a stacked structure in which a p-GaN layer, an SI-GaN layer, and an AlGaN layer are stacked, and has a gate electrode that is formed at a top surface side of the AlGaN layer. A band gap of the AlGaN layer is wider than a band gap of the p-GaN layer and the SI-GaN layer. Moreover, impurity concentration of the SI-GaN layer is less than 1&#xd7;10cm. Semiconductor devices including III-V semiconductors may have a stable normally-off operation.

III-V HEMT devices

III-V hemt devices

A semiconductor device is formed by a first layercomposed of AlGaN, a second layercomposed of GaN, a gate electrode, a source electrode, and a drain electrode. The first layerhas a regionformed between the gate electrodeand the second layer. A channel is formed in the vicinity of the boundaryof the first layerand the second layer. The second layerhas p-type conductivity and is in contact with the source electrode When electrons flow in the channel, the electrons collide with surrounding atoms, and holes are formed. If holes are accumulated inside the semiconductor device, the presence of the accumulated holes causes dielectric breakdown. In the semiconductor device of the invention, holes are discharged to the outside of the device thorough the second layerand the source electrode, and accumulation of holes can be prevented.

Group III nitride semiconductor device

Growing community of inventors

Owariasahi, Japan

Yoshitaka Nakano