Furukawa Co., Ltd.

Yujiro Ishihara

Hiroki Goto

Yasuharu Fujiyama

Yasunobu Sumida

Takuya Nakagawa

Shoichi Fuda

Tomohiro Kobayashi

Hitoshi Sasaki

There is provided a method of manufacturing a group III nitride semiconductor substrate including: a fixing step Sof fixing abase substrate, which includes a group III nitride semiconductor layer having a semipolar plane as a main surface, to a susceptor; a first growth step Sof forming a first growth layer by growing a group III nitride semiconductor over the main surface of the group III nitride semiconductor layer in a state in which the base substrate is fixed to the susceptor using an HVPE method; a cooling step Sof cooling a laminate including the susceptor, the base substrate, and the first growth layer; and a second growth step Sof forming a second growth layer by growing a group III nitride semiconductor over the first growth layer in a state in which the base substrate is fixed to the susceptor using the HVPE method.

Method of manufacturing group III nitride semiconductor substrate, group III nitride semiconductor substrate, and bulk crystal

According to the present invention, there is provided a group III nitride semiconductor substrate (free-standing substrate) that is formed of group III nitride semiconductor crystals. Both exposed first and second main surfaces in a relationship of top and bottom are semipolar planes. A variation coefficient of an emission wavelength of each of the first and second main surfaces, which is calculated by dividing a standard deviation of an emission wavelength by an average value of the emission wavelength, is 0.05% or less in photoluminescence (PL) measurement in which mapping is performed in units of an area of 1 mmby emitting helium-cadmium (He&#x2014;Cd) laser, which has a wavelength of 325 nm and an output of 10 mW or more and 40 mW or less, at room temperature. In a case where devices are manufactured over the free-standing substrate, variations in quality among the devices are suppressed.

Group III nitride semiconductor substrate

There is provided a group III nitride semiconductor substrate (free-standing substrate ()) that is formed of a group III nitride semiconductor crystal and has a thickness of 300 &#x3bc;m or more and 1000 &#x3bc;m or less. Both exposed first and second main surfaces in a relationship of top and bottom are semipolar planes. A difference in a half width of an X-ray rocking curve (XRC) measured by making X-rays incident on each of the first and second main surfaces in parallel to an m axis of the group III nitride semiconductor crystal is 500 arcsec or less.

Group III nitride semiconductor substrate and method of manufacturing group III nitride semiconductor substrate

A method for manufacturing a group III nitride semiconductor substrate includes a preparation step Sfor preparing a group III nitride semiconductor substrate having a sapphire substrate having a semipolar plane as a main surface, and a group III nitride semiconductor layer positioned over the main surface, in which a &#x3c;0002&#x3e; direction of the sapphire substrate and a &#x3c;10-10&#x3e; direction of the group III nitride semiconductor layer do not intersect at right angles in a plan view in a direction perpendicular to the main surface, and a growth step Sfor epitaxially growing a group III nitride semiconductor over the group III nitride semiconductor layer.

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Tochigi, Japan

Yujiro Ishihara