1990 Volume 23 Issue 3 Pages 286-290
For CZ crystal growth of an oxide (Al2O5), finite element analyses of the thermal stress field in the crystal are carried out, and the effect of interface shape on the maximum shear stress in the crystal is investigated.
When the crystal rotation rate increases, with other operating conditions unchanged, the melt/crystal interface changes its shape from convex to concave toward the melt at the critical Reynolds number (Res*). When Res < Res*, the maximum value of the thermal stress on the interface is insensible to Res and its radial profile is an inversed W-shape. When Res exceeds Res*, however, thermal stress on the interface increases very rapidly and its radial profile becomes W-shaped.