Dopant Segregation in CZ and MCZ Silicon Crystal Growth: A Comparison Between Experiment and Numerical Simulation

Abstract

Solute transport in Czochralski (CZ) crystal growth and in magnetic Czochralski (MCZ) with a vertical applied field are simulated numerically, and compared with published experimental data on gallium segregation in silicon growth. In the MCZ cases, the low segregation coefficient of 0.008 leads to a steep concentration gradient under the s/1 interface due to a boundary layer buildup of rejected gallium. This required a high resolution computation and a segregation model accounting for the melt drift toward the interface. Also, the relatively high density of gallium compared with silicon melt made it necessary to include solutal convection. With these improvements to the simulation code, good agreement with the data was achieved in the CZ growth and in the MCZ growth at 0.1 and 0.3 tesla. © 1989, The Electrochemical Society, Inc. All rights reserved.