Nucleation and crystal growth of Si _1-xGe _x melts during rapid cooling processes: A molecular-dynamics study

To clarify the growth mechanism of the lateral growth of Ge in the rapid-melting-growth process, two types of molecular-dynamics simulation were investigated in this study. One was the nucleation of Si _1-xGe _x (0 ≤ × ≤ 1) from supercooled melts, and the other is the growth rate of supercooled Si _1-xGe _x melts using a crystalline Si _1-xGex seed. The incubation time is found to be minimum at approximately 0.70 T _m (T _m: melting temperature for Si _1-xGe _x ). No nucleation was found when the temperature was higher than 0.75 T _m. The crystal growth rates of Si _1-xGe _x peaked between 0.90 T _m and 0.94 T _m for both the [100] and [111] orientations. These results suggest that 0.90 T _m to 0.94 T _m of Si _1-xGe _x (x = 1) is an optimum temperature range to grow crystalline Ge in the rapid-melting-growth process.