Axial gradient transport growth process and apparatus utilizing resistive heating

摘要

A crucible has a first resistance heater is disposed in spaced relation above the top of the crucible and a second resistance heater with a first resistive section disposed in spaced relation beneath the bottom of the crucible and with a second resistive section disposed in spaced relation around the outside of the side of the crucible. The crucible is charged with a seed crystal at the top of an interior of the crucible and a source material in the interior of the crucible in spaced relation between the seed crystal and the bottom of the crucible. Electrical power of a sufficient extent is applied to the first and second resistance heaters to create in the interior of the crucible a temperature gradient of sufficient temperature to cause the source material to sublimate and condense on the seed crystal thereby forming a growing crystal.

主权项

1. An axial gradient growth method comprising:
(a) providing a crucible having a top, a bottom and a side that extends between the top of the crucible and a bottom of the crucible, a first resistance heater disposed in spaced relation above the top of the crucible, and a second, cup-shaped resistance heater having a first resistive section disposed in spaced relation beneath the bottom of the crucible and a second resistive section that extends from the first resistive section in a direction toward the first resistance heater and terminates intermediate the top and the bottom of the crucible in spaced relation around the outside of the side of the crucible; (b) providing a seed crystal at the top of an interior of the crucible and a source material in the interior of the crucible in spaced relation between the seed crystal and the bottom of the crucible and in contact with the side of the crucible, wherein all of the source material is spaced from the bottom of the crucible by a gap between all of the source material and the bottom of the crucible; (c) applying electrical power to the first and second resistance heaters of a sufficient extent to create in the interior of the crucible a temperature gradient of sufficient temperature to cause the source material to sublimate and condense on the seed crystal thereby forming a growth crystal; and (d) maintaining the electrical power to the first and second resistance heaters until the growth crystal has grown to a desired size.