Three-dimensional modeling of SiGe by the traveling solvent method in the presence of magnetic field and rotating crucible

Tawfiq J. Jaber, Ryerson University

Date of Award

2006

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

M Z Saghir

Abstract

A three-dimensional numerical simulation study was carried out for crystal growth of SiGe by the traveling solvent method (TSM). The effects of magnetic field intensity and sample rotation on the transport structures (fluid flow, heat and mass transfer and concentration) in the solvent were investigated in detail. The full steady-state Navier-Stokes equations, as well as the energy, mass transport and continuity equations were solved numerically using the finite element method. An external axial magnetic field is applied to suppress convection in the solvent. It was found that the intensity of the flow at the centre of the crucible decreases at a faster rate compared to the flow near the walls when increasing the magnetic field intensity.

This behaviour creates a stable and uniform silicon distribution in the horizontal plane near the growth interface. The application of crucible rotation in the presence of the axial magnetic field is an attempt to control the buoyancy induced convention throughtout the solvent region. It was observed that, in the application of rotation, there is no significant change to suppress the flow intensity. It was found that the rotating magnetic field (RMF) has a marked effect on the silicon concentration, changing it from convex to nearly flat when the magnetic field intensity increases. An alternative method for removing buoyancy convection from the melt is growing the crystal in a gravity free environment. The microgravity (104ˉg) is numerically simulated and compared with the ground base condition.