The Furukawa Electric Co., Ltd.

Fuji Electric Co., Ltd.

Shinya Ootomo

Seikoh Yoshida

Takehiko Nomura

Masayuki Iwami

Hiroshi Kambayashi

Tatsuyuki Shinagawa

Yuki Niiyama

Yoshihiro Sato

Sadahiro Kato

Keishi Takaki

Hitoshi Sasaki

Kazuyuki Umeno

Ryosuke Tamura

Yuki Niyama

A semiconductor multi-layer substrate includes a substrate made of Si and a multi-layer semiconductor layer. The multi-layer semiconductor layer includes an active layer made of a nitride semiconductor, a first warp control layer being formed between the substrate and the active layer and giving a predetermined warp to the substrate, and a second warp control layer made of a nitride semiconductor of which amount of an increase in a warp per a unit thickness is smaller than an amount of increase in the warp per a unit thickness of the first warp control layer. A total thickness of the multi-layer semiconductor layer is equal to or larger than 4 &#x3bc;m.

Semiconductor multi-layer substrate, semiconductor device, and method for manufacturing the same

Provided is a normally-off field effect transistor using a III-nitride semiconductor. The transistor is provided with a III-nitride semiconductor layer grown on a substrate by including an acceptor and a donor; a gate insulating film which is formed on the III-nitride semiconductor layer to have a thickness to be at a prescribed threshold voltage based on the concentration of the acceptor and that of the donor; a gate electrode formed on the gate insulating film; a first source/drain electrode formed on the III-nitride semiconductor layer to one side of and separate from the gate electrode, directly or via a high dopant concentration region; and a second source/drain electrode formed away from the gate electrode and the first source/drain electrode, on or under the III-nitride semiconductor layer, directly or via a high dopant concentration region.

Normally-off field effect transistor using III-nitride semiconductor and method for manufacturing such transistor

A field effect transistor formed of a semiconductor of a III group nitride compound, includes an electron running layer formed on a substrate and formed of GaN; an electron supplying layer formed on the electron running layer and formed of AlGaN (0.01&#x2266;x&#x2266;0.4), the electron supplying layer having a band gap energy different from that of the electron running layer and being separated with a recess region having a depth reaching the electron running layer; a source electrode and a drain electrode formed on the electron supplying layer with the recess region in between; a gate insulating film layer formed on the electron supplying layer for covering a surface of the electron running layer in the recess region; and a gate electrode formed on the gate insulating film layer in the recess region. The electron supplying layer has a layer thickness between 5.5 nm and 40 nm.

Field effect transistor

A vertical semiconductor element comprises: an electro-conductive substrate; a GaN layer, as a nitride compound semiconductor layer, which is selectively grown as a convex shape on one surface of the electro-conductive substrate through a buffer layer; a source electrode as a first electrode formed on the GaN layer; and a drain electrode as a second electrode formed on another surface of the electro-conductive substrate.

Vertical type semiconductor device and manufacturing method of the device

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Tokyo, Japan

Shinya Ootomo