Sanken Electric Co., Ltd.

Masataka Yanagihara

Koji Otsuka

Tetsuji Moku

Nobuo Kaneko

Tetsuji Matsuo

Masahiro Sato

Emiko Chino

Masaaki Kikuchi

Kohji Ohtsuka

A semiconductor device includes a silicon substrate, an aluminum nitride layer which is arranged on the silicon substrate and has a region where silicon is doped thereof as an impurity, a buffer layer which is arranged on the aluminum nitride layer and has a structure where a plurality of nitride semiconductor films are laminated, and a semiconductor functional layer which is arranged on the buffer layer and made of nitride semiconductor.

Semiconductor device having nitride semiconductor layer

A semiconductor device includes a substrate, a buffer layer, and a compound semiconductor layer. The buffer layer is configured by laminating two or more pairs of a first buffer and a second buffer. The first buffer is formed by laminating one or more pairs of an AlN layer and a GaN layer. The second buffer is formed of a GaN layer. A total Al composition of a pair of the first buffer and the second buffer on the compound semiconductor layer side is higher than that of a pair of the first buffer and the second buffer on the substrate side.

Semiconductor device with buffer layer for mitigating stress exerted on compound semiconductor layer

A high electron mobility transistor is disclosed which has a triple-layered main semiconductor region formed on a silicon substrate via a multilayered buffer region. The multilayered buffer region is in the form of alternations of an aluminum nitride layer and a gallium nitride layer. Whilst the aluminum nitride layers are of n-like conductivity, the gallium nitride layers are doped into p-type conductivity, with the consequent creation of pn junctions between the two kinds of buffer layers. Another pn junction is formed between one p-type gallium nitride layer and the adjoining n-like electron transit layer included in the main semiconductor region. The pn junctions serve for reduction of current leakage.

Nitride-based semiconductor device with reduced leakage current

A main semiconductor region of semiconducting nitrides is formed on a silicon substrate via a buffer region of semiconducting nitrides to provide devices such as HEMTs, MESFETs and LEDs. In order to render the wafer proof against warping, the buffer region is divided into a first and a second multilayered buffer subregion. The first buffer subregion comprises multiple alterations of a multi-sublayered first buffer layer and a non-sublayered second buffer layer. Each multi-sublayered first buffer layer of the first buffer subregion comprises multiple alternations of a first and a second buffer sublayer. The second buffer sublayers of each multi-sublayered first buffer layer either do not contain aluminum or do contain it in a higher proportion than do the first buffer sublayers. The second multilayered buffer subregion comprises multiple alternations of a first and a second buffer layer. The first buffer layers of the second multilayered buffer subregion are less in aluminum proportion than the fourth buffer layers of the second multilayered buffer subregion.

Semiconductor wafer, devices made therefrom, and method of fabrication

A semiconductor device having nitride semiconductor layers has a buffer layer () in the form of alternations of a first sublayer () of AlN and a second layer () of GaN with interposition of a third layer () of p-type GaN therebetween. On this buffer layer there is grown a main semiconductor region () having nitride semiconductor layers for providing a high-electron-mobility transistor or the like. From 0.5 to 50.0 nanometers thick, the third sublayers () of the buffer layer restrict the generation of two-dimensional electron gas and so prevent the buffer layer from becoming unnecessarily low in resistance.

Gallium-nitride-based compound semiconductor device

A substrate system of the kind having a buffer region interposed between a silicon substrate proper and a nitride semiconductor region in order to make up for a difference in linear expansion coefficient therebetween. Electrodes are formed on the nitride semiconductor layer or layers in order to provide HEMTs or MESFETs. The buffer region is a lamination of a multiplicity of buffer layers each comprising a first, a second, and a third buffer sublayer of nitride semiconductors, in that order from the silicon substrate proper toward the nitride semiconductor region. The three sublayers of each buffer layer contain aluminum in varying proportions including zero. The aluminum proportion of the third buffer sublayer is either zero or intermediate that of the first buffer sublayer and that of the second. The low aluminum proportion of the third buffer sublayer serves to prevent two-dimensional electron gas from generating in the buffer region and hence to make this region sufficiently high in resistance to inhibit current leakage from the HEMTs or MESFETs.

Nitride semiconductor substrate and semiconductor element built thereon

A low-resistance silicon baseplate () has formed thereon a buffer layerin the form of an alternating lamination of AlN sublayers () and GaN sublayers (). On this buffer layer there are formed an n-type semiconductor region () of gallium nitride, an active layer () of gallium indium nitride, and a p-type semiconductor region () of gallium nitride, in that order. An anode () is formed on the p-type semiconductor region (), and a cathode () on the baseplate ().

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Niiza, Japan

Masataka Yanagihara