ROLE OF SHIELD AROUND CRYSTAL IN CZOCHRALSKI PROCESS

The influence of shield around crystal on gas-and hydrodynamics, heat transfer and defects formation in Czochralski silicon crystal growth process is studied by means of mathematical modeling. The domestic silicon crystal growth furnace Redmet-90M is considered, which allows the silicon single crystal growing with 200 mm in diameter and 1.5 m in length. The growth process occurs under argon flow pumping in the rarefied atmosphere of growth camera. High-temperature heating ensures silicon melting in crucible and silicon ingot crystallization by Czochralski pulling from a melt. The mathematical model considers the conjugation of heat exchange and silicon monoxide transfer processes. The effect of shield around crystal on axial temperature distribution in grown single crystal is considered. For dislocation-free single crystals this characterizes the type of forming intrinsic point defects. The international verification results of the shield around crystal influence on axial temperature distribution in the growing crystal for Czochralski crystal growth furnace EKZ-1300 are discussed. Also, the verification results in application to Czochralski crystal growing on EKZ-1600ELMA are presented, which illustrate the application of defect formation theory of V.V. Voronkov in dislocation-free single silicon crystals.

crystal growth, silicon, defects, shield, modeling, hydro- and gas dynamics, heat transfer, impurity