Control of Oxygen Segregation in Czochralski Silicon Crystals Through Combining Magnetic Field and Crystal Rotation
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
In large-diameter Czochralski (CZ) silicon crystal growth, the oxygen level is usually high (> 30 ppma), and radial and axial uniformity does not exist. According to the teachings of the present disclosure, thermal convection is suppressed by an axial magnetic field, and by varying the crystal rotation rate, oxygen concentration is controlled to a low to medium level by virtue of the forced convection due to the crystal rotations. In the CZ silicon crystal growth, a fused silica crucible is used to contain the silicon melt. As a result of the reaction and dissolution of the fused silica, the silicon melt is contaminated with silicon-oxygen species.