Sumitomo Electric Industries, Limited

Keiichi Yui

Ken Nakata

Isao Makabe

Tsuyoshi Kouchi

Takamitsu Kitamura

Hiroyuki Ichikawa

Akira Furuya

A process of forming an epitaxial wafer is disclosed. The process includes steps of (a) growing an aluminum nitride (AlN) layer at a first temperature and a first flow rate of ammonia (NH); and (b) growing a gallium nitride (GaN) layer on the AlN layer. The step (b) includes a first period and a second period. At least one of a temperature from the first temperature to a second temperature that is lower than the first temperature and a flow rate of NHfrom the first flow rate to a second flow rate different from the first flow rate is carried out during the first period. The second period grows the GaN layer at the second temperature and the second flow rate of NH.

Process of forming epitaxial wafer

A process of forming a High Electron Mobility Transistor (HEMT) made of nitride semiconductor materials is disclosed. The process sequentially grows a buffer layer, a n-type layer doped with n-type dopants, and a channel layer by a metal organic chemical vapor deposition (MOCVD) technique. A feature of the process is to supply only an n-type dopant gas before the growth of the n-type layer but after the growth of the buffer layer.

Process for forming a high electron mobility transistor

A method of manufacturing a semiconductor device according to one aspect of the present invention includes a step of forming a first layer of InAlN, a step of forming a second layer of InAlGaN on the first layer under a growth temperature higher than that of the first layer, and a step of forming a third layer of GaN, AlGaN or InGaN under a growth temperature higher than that of the first layer.

Semiconductor device and method of manufacturing the same

A GaN device suppressing the instantaneous current reduction after the shut-off of a high frequency signal is disclosed. The GaN device provides, on a SiC substrate, an AlN layer, a GaN layer, and an AlGaN layer, The SiC substrate has an energy difference greater than 0.67 eV but less than 1.43 eV; the AlN layer has a thickness less than 50 nm; and the GaN layer has a thickness less than 1.5 &#x3bc;m.

Nitride semiconductor device with limited instantaneous current reduction

The semiconductor device includes a SiC substrate; an aluminum nitride layer provided on the substrate and having an island-shaped pattern consisting of plural islands: a channel layer provided on the AlN layer and comprising a nitride semiconductor; an electron supplying layer provided on the channel layer and having a band gap larger than that of the channel layer; and a gate, source and drain electrodes on the electron supply layer. The AlN layer has an area-averaged circularity Y/X of greater than 0.2. Y is a sum of values obtained by multiplying circularities of the plural islands by areas of the plural islands respectively, X is a sum of the areas of the plural islands. The circularity are calculated by a formula of (4&#x3c0;&#xd7;area)/(length of periphery)where the area and the length of periphery are an area and a length of periphery of each island.

Semiconductor device including an aluminum nitride layer having a calculated area-averaged circularity and a method of manufacturing the device

A method of manufacturing a semiconductor device includes growing a first GaN layer on a SiC substrate, and forming a second GaN layer on the first GaN layer, the second GaN layer being grown under such conditions that a ratio of a vertical growth rate to a horizontal growth rate is lower than that in the growth of the first GaN layer.

Method of manufacturing semiconductor device

A method for fabricating a semiconductor device includes performing thermal cleaning for a surface of a silicon substrate in an atmosphere including hydrogen under a condition that a thermal cleaning temperature is higher than or equal to 700&#xb0; C. and is lower than or equal to 1060&#xb0; C., and a thermal cleaning time is longer than or equal to 5 minutes and is shorter than or equal to 15 minutes; forming a first AlN layer on the substrate with a first V/III source ratio, the forming of the first AlN layer including supplying an Al source to the surface of the substrate without supplying a N source, and supplying both the Al source and the N source; forming a second AlN layer on the first AlN layer with a second V/III source ratio that is greater than the first ratio; and forming a GaN-based semiconductor layer on the second AlN layer.

Method for fabricating semiconductor device

A semiconductor device includes a Si substrate having a principal plane that is a crystal surface inclined at an off angle of 0.1 degrees or less with respect to a (111) plane, an AlN layer that is provided so as to contact the principal plane of the Si substrate and is configured so that an FWHM of a rocking curve of a (002) plane by x-ray diffraction is not greater than 2000 seconds, and a GaN-based semiconductor layer formed on the AlN layer.

Semiconductor device

A semiconductor device includes an AlGaN layer that is provided on a SiC substrate and has an acceptor concentration equal to or higher than a donor concentration, a GaN layer provided on the AlGaN layer, and an electron supply layer that is provided on the GaN layer and has a band gap greater than that of GaN.

A semiconductor device includes a first GaN layer provided on a SiC substrate, a second GaN layer provided on the first GaN layer, and an electron supply layer that is provided on the second GaN layer and has a band gap greater than that of GaN, the first GaN layer having an acceptor concentration higher than that of the second GaN layer.

A semiconductor substrate includes an AlN layer that is formed so as to contact a Si substrate and has an FWMH of a rocking curve of a (002) plane by x-ray diffraction, the FWMH being less than or equal to 1500 seconds, and a GaN-based semiconductor layer formed on the AlN layer.

Semiconductor substrate and semiconductor device

A method for fabricating a semiconductor device includes forming an AlN layer on a substrate made of silicon by supplying an Al source without supplying a N source and then supplying both the Al source and the N source, and forming a GaN-based semiconductor layer on the AlN layer after the forming of the AlN layer. The forming of the AlN layer grows the AlN layer so as to satisfy the following:76500/53800/where x is a thickness of the AlN layer and y is an FWHM of a rocking curve of a (002) plane of the AlN layer.

Growing community of inventors

Kanagawa, Japan

Keiichi Yui