Abstract: Provided is a method for growing a ?-Ga2O3-based single crystal, whereby it becomes possible to grow a ?-Ga2O3-based single crystal having a small variation in crystal structure and also having a high quality in the direction of a b axis. In one embodiment, a method for growing a ?-Ga2O3-based single crystal includes growing a plate-shaped Sn doped ?-Ga2O3-based single crystal in the direction of the b axis using a seed crystal.

Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? 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 ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s 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 ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.

Abstract: Provided are: a method for producing a ?-Ga2O3 substrate 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 ?-Ga2O3 substrate includes a step for cutting out a ?-Ga2O3 substrate from a ?-Ga2O3 crystal containing a group IV element; annealing processing in an atmosphere containing a reducing atmosphere and/or an inert gas atmosphere is performed on the ?-Ga2O3 crystal before cutting out the ?-Ga2O3 substrate, or on the cut-out ?-Ga2O3 substrate.

Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.

Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal which uses the EFG method and includes raising a Ga2O3 melt inside a crucible up to a die opening via a die slit such that a seed crystal is contacted with the Ga2O3-based melt in the opening of the die with a horizontal position of the seed crystal shifted in a width direction (W) from a center in the width direction (W) of the die, and pulling up the seed crystal contacting the Ga2O3-based melt so as to grown a ?-Ga2O3 single crystal.

Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.

Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? 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 ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s 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 ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.

Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.

Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal which uses the EFG method and includes raising a Ga2O3 melt inside a crucible up to a die opening via a die slit such that a seed crystal is contacted with the Ga2O3-based melt in the opening of the die with a horizontal position of the seed crystal shifted in a width direction (W) from a center in the width direction (W) of the die, and pulling up the seed crystal contacting the Ga2O3-based melt so as to grown a ?-Ga2O3 single crystal.

Abstract: Provided is a method for growing a ?-Ga2O3-based single crystal, whereby it becomes possible to grow a ?-Ga2O3-based single crystal having a small variation in crystal structure and also having a high quality in the direction of a b axis. In one embodiment, a method for growing a ?-Ga2O3-based single crystal includes growing a plate-shaped Sn doped ?-Ga2O3-based single crystal in the direction of the b axis using a seed crystal.

Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.

Abstract: A Ga2O3-based single crystal substrate includes a main surface including BOW of not less than ?13 ?m and not more than 0 ?m. The main surface may further include WARP of not more than 25 ?m. The main surface may further include TTV of not more than 10 ?m.

Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105/cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.

Abstract: Provided are: a method for producing a ?-Ga2O3 substrate 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 ?-Ga2O3 substrate includes a step for cutting out a ?-Ga2O3 substrate from a ?-Ga2O3 crystal containing a group IV element; annealing processing in an atmosphere containing a reducing atmosphere and/or an inert gas atmosphere is performed on the ?-Ga2O3 crystal before cutting out the ?-Ga2O3 substrate, or on the cut-out ?-Ga2O3 substrate.