Temperature gradient in oxide and compound semiconductor bulk crystal growth

Abstract

  Two topics in oxide and compound semiconductor bulk crystal growth about relationship between crystal quality and temperature gradient near the growth interface are introduced. In oxide crystal growth, the occurrence of cracking during growth of an oxide crystal is associated with the polycrystallization during the shoulder formation. The effect of temperature gradient near the interface on polycrystallization shows an opposite manner between crystals grown from less viscous melt and those from highly viscous melt. A crystal fiber grown by LHPG or µ-PD method accompanies a large temperature gradient along vertical and radial directions, which induce an interface electric field modifying the transportation and partitioning of ionic species. In GaAs crystal growth, dislocations and lineages easily generate due to small critical resolved shear stress and thermal conductivity and large latent heat of fusion. Countermeasures for growing larger-scale GaAs crystals under precise control of temperature gradient and growth rate are proposed.