Sumitomo Electric Industries, Limited

Satoshi Arakawa

Hideaki Nakahata

Yoshiyuki Yamamoto

Michimasa Miyanaga

Takashi Sakurada

Takuji Okahisa

Koji Katayama

Naho Mizuhara

Tomohiro Kawase

Hiroyuki Kitabayashi

Issei Satoh

Tomoki Uemura

Keisuke Tanizaki

Muneyuki Nishioka

A method of manufacturing a nitride substrate includes the following steps. Firstly, a nitride crystal is grown. Then, the nitride substrate including a front surface is cut from the nitride crystal. In the step of cutting, the nitride substrate is cut such that an off angle formed between an axis orthogonal to the front surface and an m-axis or an a-axis is greater than zero. When the nitride crystal is grown in a c-axis direction, in the step of cutting, the nitride substrate is cut from the nitride crystal along a flat plane which passes through a front surface and a rear surface of the nitride crystal and does not pass through a line segment connecting a center of a radius of curvature of the front surface with a center of a radius of curvature of the rear surface of the nitride crystal.

Method of manufacturing nitride substrate, and nitride substrate

A group III nitride semiconductor crystal substrate has a diameter of at least 25 mm and not more than 160 mm. The resistivity of the group III nitride semiconductor crystal substrate is at least 1&#xd7;10&#x3a9;&#xb7;cm and not more than 0.1 &#x3a9;&#xb7;cm. The resistivity distribution in the diameter direction of the group III nitride semiconductor crystal is at least &#x2212;30% and not more than 30%. The resistivity distribution in the thickness direction of the group III nitride semiconductor crystal is at least &#x2212;16% and not more than 16%.

Group III nitride semiconductor crystal substrate and semiconductor device

A method of producing an AlGaN (0&#x3c;x&#x2266;1) single crystal of the present invention is directed to growing an AlGaN single crystal by sublimation. The method includes the steps of preparing an underlying substrate, preparing a raw material of high purity, and growing an AlGaN single crystal on the underlying substrate by sublimating the raw material. At the AlGaN single crystal, the refractive index with respect to light at a wavelength greater than or equal to 250 nm and less than or equal to 300 nm is greater than or equal to 2.4, and the refractive index with respect to light at a wavelength greater than 300 nm and less than 350 nm is greater than or equal to 2.3, measured at 300K.

[object Object]

A method of manufacturing a semiconductor element of good characteristics at a reduced manufacturing cost is provided. The manufacturing method of the semiconductor element includes a GaN-containing semiconductor layer forming step, an electrode layer forming step, a step of forming an Al film on the GaN-containing semiconductor layer, a step of forming a mask layer made of a material of which etching rate is smaller than that of a material of the Al film, a step of forming a ridge portion using the mask layer as a mask, a step of retreating a position of a side wall of the Al film with respect to a position of a side wall of the mask layer, a step of forming, on the side surface of the ridge portion and the top surface of the mask layer, a protective film made of a material of which etching rate is smaller than that of the material forming the Al film, and a step of removing the Al film and thereby removing the mask layer and a portion of the protective film formed on the top surface of the mask layer.

Manufacturing method of a semiconductor element

Growing community of inventors

Itami, Japan

Satoshi Arakawa