Numerical Simulation of Crystal Growth by the Vertical Bridgman Method
St. Boschert,
Alfred Schmidt,
Kunibert G. Siebert
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Abstract:
Single crystals of (Cd,Zn)Te are an excellent substrate material for
epitaxial growth of (Hg,Cd)Te layers and are usually grown by the
vertical Bridgman method. We present a simulation of the whole growth
process in two steps: In the first step, the (stationary) heat
transport in the furnace is modeled and calculated for different
positions of the ampoule. This gives information about the most
important parameter during this process: the temperature
distribution in furnace and ampoule. The obtained temperatures are
then used in the second step as boundary conditions for the (time
dependent) simulation of temperature and convection in the ampoule.
For the discretization of the convection in the melt, a penalty method
for treating parabolic problems on time dependent domains is
presented. Only the use of adaptive finite element methods allows an
efficient numerical simulation of the moving phase boundary, the
convection in the melt and the temperature distribution in melt and
crystal. Numerical results are presented for both furnace and
ampoule simulation.
Key words.
Crystal growth, phase transition, Navier-Stokes on time dependent domains,
adaptive finite elements
Graph of enthalpy (top) and convection in the melt (bottom) for three
different times of the simulation.
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in J.S. Szmyd and K. Suzuki (Eds.): Modelling of Transport
Phenomena in Crystal Growth, Development in Heat Transfer Series, WIT Press (2000), 61-96.
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