We studied the process of oxygen transfer from a quartz crucible to a multicrystalline silicon during unidirectional solidification process. We investigated the boundary layer thickness of oxygen concentration near a crucible wall region using Fourier transform infrared spectrometer (FTIR) measurement. The results suggest that oxygen concentration was increased near a crucible wall, and the boundary layer thickness of oxygen concentration was estimated to be 2-6 mm. The estimated value of boundary layer thickness of oxygen concentrations is similar to those estimated by analytical and numerical calculation. These results suggest that the oxygen was dissolved from a crucible wall through the liner made Of Si3N4 to the melt during growth process. (C) 2008 Elsevier B.V. All rights reserved.