Contact

Dr. Vladimir Galindo

v.galindoAthzdr.de
Phone: +49 351 260 3391

Dr. Sven Eckert

Head Magneto­hydro­dynamics
s.eckertAthzdr.de
Phone: +49 351 260 2132

Physical modelling of Czochralski crystal growth

Cz model experiments

At laboratory scales model experiments are an often used approach to industrial processes such as the Czochralski crystal growth method. Due to the availability of suitable measuring techniques, the low melting alloy GaInSn, which is liquid at room temperature became meanwhile as de facto standard.

The studies focus on the influence of various magnetic fields on the melt flow and the related heat transport in crucibles being heated from the bottom and/or side, and cooled by a crystal model covering about 1/3 of the upper melt surface.

Cz-model crucible Experimental setup

  • Cz-model with a 7“ crucible perfectly fits to large-scale Si case
  • independent rotation of crucible and crystal

Goal:
Electromagnetic control of melt flow, heat transfer and dopant distri-bution in electronic or photovoltaic silicon or GaAs, etc. growth processes

  • Large scale buoyant flow in the crucible
  • Temperature fluctuations and gradients at the interface crystal-melt-atmosphere

Methods:

  • UDV flow measurements with small transducers (opaque fluids)
  • Temperature measurements with fast and thin thermocouples
  • Control by magnetic fields (MULTIMAG system)

Publications