Tamura Corporation

Koha Co., Ltd.

Yu Yamaoka

Shinya Watanabe

Masaru Takizawa

Takekazu Masui

Kimiyoshi Koshi

Makoto Watanabe

Kazuyuki Iizuka

Daiki Wakimoto

A &#x3b2;-GaO-based single-crystal substrate includes a &#x3b2;-GaO-based single crystal, and a principal surface being a plane parallel to a b-axis of the &#x3b2;-GaO-based single crystal. A maximum value of &#x394;&#x3c9; on an arbitrary straight line on the principal surface that passes through a center of the principal surface is not more than 0.7264. The &#x394;&#x3c9; is a difference between a maximum value and a minimum value of values obtained by subtracting &#x3c9;from &#x3c9;at each of measurement positions, where &#x3c9;represents an angle defined by an X-ray incident direction and the principal surface at a peak position of an X-ray rocking curve on the straight line and &#x3c9;represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the &#x3c9;and the measurement positions thereof.

&#x3b2;-Ga2O3 single-crystal substrate

Provided are: a method for producing a &#x3b2;-GaOsubstrate of which changes in donor concentration in a reducing atmosphere or an inert gas atmosphere are suppressed; and a method for producing a crystal laminate structure that can epitaxially grow a high-quality crystal film having low variability of quality in a reducing atmosphere or an inert gas atmosphere. The method for producing a &#x3b2;-GaOsubstrate includes a step for cutting out a &#x3b2;-GaOsubstrate from a &#x3b2;-GaOcrystal containing a group IV element; annealing processing in an atmosphere containing a reducing atmosphere and/or an inert gas atmosphere is performed on the &#x3b2;-GaOcrystal before cutting out the &#x3b2;-GaOsubstrate, or on the cut-out &#x3b2;-GaOsubstrate.

[object Object]

A &#x3b2;-GaO-based single crystal substrate includes an average dislocation density of less than 7.31&#xd7;10cm. The average dislocation density may be not more than 6.14&#xd7;10cm. The substrate may further include a main surface including a plane orientation of (&#x2212;201), (101) or (001). The substrate may be free from any twinned crystal.

&#x3b2;-Ga2O3-based single crystal substrate

A &#x3b2;-GaO-based single crystal substrate includes a &#x3b2;-GaO-based single crystal. The &#x3b2;-GaO-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.

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Tokyo, Japan

Yu Yamaoka