Single crystal growth apparatus
A single crystal growth apparatus to grow a single crystal of a gallium oxide-based semiconductor. The apparatus includes a crucible that includes a seed crystal section to accommodate a seed crystal, and a growing crystal section which is located on the upper side of the seed crystal section and in which the single crystal is grown by crystallizing a raw material melt accommodated therein, a tubular susceptor surrounding the seed crystal section and also supporting the crucible from below, and a molybdenum disilicide heating element to melt a raw material in the growing crystal section to obtain the raw material melt. The susceptor includes a thick portion at a portion in a height direction that is thicker and has a shorter horizontal distance from the seed crystal section than other portions. The thick portion surrounds at least a portion of the seed crystal section in the height direction.
1 . A single crystal growth apparatus to grow a single crystal of a gallium oxide-based semiconductor, the single crystal growth apparatus comprising:
a crucible that comprises a seed crystal section to accommodate a seed crystal, and a growing crystal section which is located on an upper side of the seed crystal section and in which the single crystal is grown by crystallizing a raw material melt accommodated therein;
a tubular susceptor surrounding the seed crystal section and also supporting the crucible from below; and
a molybdenum disilicide heating element to melt a raw material in the growing crystal section to obtain the raw material melt,
wherein the susceptor comprises a thick portion at a portion in a height direction that is thicker and has a shorter horizontal distance from the seed crystal section than an other portion, and
wherein the thick portion surrounds at least a portion of the seed crystal section in the height direction,
wherein an upper end of the thick portion in the height direction of the susceptor is located lower than an upper end of the seed crystal section in the height direction of the susceptor during growth of the single crystal in the growing crystal section,
wherein the seed crystal section is connected to the growing crystal section,
wherein the thick portion protrudes from the other portion in a horizontal direction of the susceptor such that a surface of the upper end of the thick portion is exposed.
2 . The single crystal growth apparatus according to claim 1 , wherein a value of a ratio of an inner diameter of the thick portion to an outer diameter of the seed crystal section is not more than 2.5.
3 . The single crystal growth apparatus according to claim 1 , wherein a lower end of the thick portion is located higher than a lower end of the seed crystal section.
4 . The single crystal growth apparatus according to claim 1 , wherein a width of the thick portion in the height direction is not less than 16 mm.