Crystal Growth Behaviors of Silicon during Melt Growth Processes
Figure 17
Schematic images of growth of Si dendrite [73, 74]. (a) Equilibrium form of a crystal with two twins, which is bounded by habit planes. It is considered that the crystal grows only in the direction for simplicity. A reentrant corner of 141° angle (type I) appears at the growth surface only at twin1. (b) A triangular corner is formed owing to the rapid growth at the type I corner at twin1. (c) Crystal growth can continue on the flat surface although the rapid growth is inhibited because of the disappearance of the type I corner. When the triangular crystal propagates across twin2, two new type I corners are formed at twin2. (d) Rapid growth occurs at the two type I corners again, and a triangular corner is formed. (e) After the propagation of the crystal, a type I corner is formed at twin1. (f) Rapid growth occurs at a type I corner. A faceted dendrite continues to grow along the direction by repeating the process from (b) to (f). The tip of the dendrite becomes wider with crystal growth.