Ngk Insulators, Inc.

Dowa Electronics Materials Co., Ltd.

Nagoya Institute of Technology

Takashi Egawa

Mitsuhiro Tanaka

Masahiro Sakai

Tomohiko Shibata

Makoto Miyoshi

Ryo Sakamoto

Osamu Oda

Jo Shimizu

Tsuneo Ito

Hiroyasu Ishikawa

A semiconductor material is provided comprising: a composition graded layer, formed on a Si substrate or an interlayer formed thereon, comprising a composition of AlGaN graded such that a content ratio of Al in the composition decreases continuously or discontinuously in a crystal growing direction; a superlattice composite layer, formed on the composition graded layer, comprising a high Al-containing layer comprising a composition of AlGaN and a low Al-containing layer comprising a composition of AlGaN that are laminated alternately; and a nitride semiconductor layer formed on the superlattice composite layer.

Semiconductor material, method of making the same, and semiconductor device

A technique for suppressing the bowing of an epitaxial wafer is provided. The epitaxial wafer is prepared by successively epitaxially growing a target group III-nitride layer, an interlayer and another group III-nitride layer on a substrate with a buffer layer. The interlayer is mainly composed of a mixed crystal of GaN and InN expressed in a general formula (GaIn)N (0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, x+y=1) (or a crystal of GaN), and does not contain Al. The interlayer is epitaxially formed at a lower growth temperature than those of the group III-nitride layers, more specifically at a temperature in a range of at least 350&#xb0; C. to not more than 1000&#xb0; C.

Epitaxial wafers, method for manufacturing of epitaxial wafers, method of suppressing bowing of these epitaxial wafers and semiconductor multilayer structures using these epitaxial wafers

A method for manufacturing a nitride film including a high-resistivity GaN layer includes a step of allowing a Group-III source gas containing an organic metal compound, a Group-V source gas containing ammonia, a carrier gas for the Group-III source gas, and a carrier gas for the Group-V source gas to flow over a predetermined monocrystalline wafer maintained at 1,000&#xb0; C. or more and also includes a step of epitaxially growing a nitride film, including a GaN layer, on the monocrystalline wafer by a vapor phase reaction of the source gases. At least one of the carrier gases contains nitrogen while the wafer temperature is being increased before the reaction is carried out. At least one of the carrier gases contains hydrogen and nitrogen and has a total hydrogen and nitrogen content of 90 percent by volume or more in at least one part of the epitaxially growing step.

Method for manufacturing nitride film including high-resistivity GaN layer and epitaxial substrate manufactured by the method

An object of the present invention is to provide a semiconductor light-emitting device that reduces dislocation density and has a high luminous efficiency. A semiconductor light-emitting device has an underlayer made of nitride semiconductor containing Al and a dislocation density of 10 /cm or less. The device further has an n-type conductive layer and p-type conductive layer each composed of nitride semiconductor having an Al content smaller than that of the nitride semiconductor constituting the underlayer and having a dislocation density of 1&times;10 /cm or less. The device still further has a light emitting layer composed of nitride semiconductor having an Al content smaller than that of the nitride semiconductor constituting the underlayer and having a dislocation density of 1&times;10 /m or less, as well.

Semiconductor light-emitting devices

Growing community of inventors

Nagoya, Japan

Takashi Egawa