A study on the solid-liquid interface shape during the growth of Si _0.25Ge_0.75 in micro-gravity utilizing the bridgman method

Responding to the world's ever demanding need for flawless electronic devices such as life saving medical equipments, wireless communication sets, and digital audio and video players to name a few, which incorporate semiconductors, it is inevitable to expect defect free semiconductors to be used in them. Defects happen in the process of crystal growth at the solidification stage. Dissolution of silicon into the germanium melt is of interest for this investigation in the microgravity environment, to suppress the convection in the solvent region and also to stabilize the silicon distribution near the solid-liquid interface. The investigation is carried out by employing a three-dimensional numerical modeling and simulation of single bulk crystals of Si_0.25 Ge_0.75 growth with (Si) rich. The curvature and shape of the silicon concentration in the process of crystallization near the growth interface is the main purpose of this study. Polynomial temperature gradient was applied to observe the meridional as well as the azimuthal flow in the solvent region in earth gravity condition, near solid-liquid interface more specifically, and to determine the shape of solidification front. Results in earth gravity condition revealed that there is a strong convection in molten silicon germanium binary mixture. When heated in microgravity, it was observed that the process falls completely under pure diffusion.