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Published on Department of Mathematics (http://www.math.ohio-state.edu)

A NUMERICAL STUDY OF STEADY CRYSTAL GROWTH IN A VERTICAL BRIDGMAN DEVICE

1998
JALICS, MIKLOS KALMAN
BAKER, GREGORY R.
Electronics based on semiconductors creates an enormous demand for high quality semiconductor single crystals. The vertical Bridgman device is commonly used for growing single crystals for a variety of materials such as GaAs, InP and HgCdTe. A mathematical model is presented for steady crystal growth under conditions where crystal growth is determined strictly by heat transfer. The ends of the ampoule are chosen far away from the insulation zone to allow for steady growth. A numerical solution is sought for this mathematical model. The equations are transformed into a rectangular geometry and appropriate finite difference techniques are applied on the transformed equations. Newton's method solves the nonlinear problem. To improve efficiency GMRES with preconditioning is used to compute the Newton iterates. The numerical results are used to compare with two current asymptotic theories that assume small Biot numbers. Results indicate that one of the asymptotic theories is accurate for even moderate Biot numbers.

Source URL:
http://www.math.ohio-state.edu/node/19429