High pressure apparatus and method for nitride crystal growth

Apparatus for high pressure crystal or material processing, the apparatus comprising:

• a cylindrical capsule region comprising a first region and a second region, and a length defined between the first region and the second region;
• an annular heating member overlying a release sleeve, the release sleeve enclosing the length of the cylindrical capsule region, the release sleeve configured to be dissolved and/or etched under one or more process conditions without producing substantial dissolution and/or etching of the annular heating member;
• at least one annular metal or cermet member having a predetermined thickness disposed continuously around a perimeter of the annular heating member, the continuous annular member being made of a material having a compressive strength of about 0.5 GPa and greater and a thermal conductivity of about 100 watts per meter-Kelvin and less;
• and
• a high strength enclosure material disposed overlying the annular metal or cermet member to form a high strength enclosure.

A method of crystal growth, the method comprising:

• providing an apparatus for high pressure crystal or material processing, the apparatus comprising:
• a cylindrical capsule region comprising a first region and a second region, and a length defined between the first region and the second region;
• an annular heating member overlying a release sleeve, the release sleeve enclosing the length of the cylindrical capsule region, the release sleeve configured to be dissolved and/or etched under one or more process conditions without producing substantial dissolution and/or etching of the annular heating member;
• at least one annular ceramic or metal or cermet member having a predetermined thickness disposed continuously around a perimeter of the annular heating member, the continuous annular member being made of a material having a compressive strength of about 0.5 GPa and greater and a thermal conductivity of about 100 watts per meter-Kelvin and less;
• a high strength enclosure material disposed overlying the annular ceramic member;
• providing a capsule containing a solvent;
• placing the capsule within an interior region of the cylindrical capsule region;
• and
• processing the capsule with thermal energy to cause an increase in temperature within the capsule to greater than 200 Degrees Celsius to cause the solvent to be superheated.