Patent ID: 6863728

Claim:
An apparatus for suppressing defects during growth of silicon carbide, the apparatus comprising: a ring element, comprising: a first annular portion coupleable to a growth surface of a single crystal silicon carbide seed crystal, wherein an inner diameter of said first annular portion of said ring element is smaller than an outer diameter of said growth surface of said single crystal silicon carbide seed crystal; a first conical inner surface, said first conical inner surface defining a laterally expanding portion of a crystalline growth front, wherein an angle between said first conical inner surface and a ring element axis is greater than 25 degrees; a graphite heat sink coupleable to a non-growth surface of said single crystal silicon carbide seed crystal; a growth chamber coupleable to said ring element and a silicon carbide source; a graphite crucible substantially enclosing said growth chamber; a first heating means for applying at least a first temperature gradient and a second temperature gradient to said growth chamber, wherein said first temperature gradient promotes axial crystal growth and promotes lateral crystal expansion, and wherein said second temperature gradient promotes axial crystal growth and suppresses lateral crystal growth; and a second heating means for maintaining a higher adjacent surface temperature than a crystalline growth front temperature.