Development of oxygen transport model in Czochralski growth of silicon crystals

Oxygen is one of the most important impurities in Czochralski (Cz)-grown silicon crystals. The precise control of oxygen concentration in growing crystal, both in radial and in axial directions, is required to obtain silicon wafers with necessary electronic properties. A modified numerical model of oxygen transport as a way of prediction of oxygen concentration in growing Si crystals is described in this paper. Test calculations for the updated model were performed for a Cz setup with a small crucible diameter and weak turbulent melt flow. The calculated oxygen profile along the crystallization front is compared with available experimental data. 2-D and 3-D calculation results have evaluated the number of finite volumes in 3-D grid, required for precise description of oxygen transport in the small growth system.