Determination of Oxygen Concentration in Heavily Doped Silicon Wafer by Laser Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has been applied to determine the oxygen concentration in heavily doped silicon wafer by using a high power pulsed laser and an optical fibre coupled CCD spctrometer. The relative concentration of oxygen in the heavily doped silicon wafer was calculated by the ratio of the integral intensity of the O-1 emission of oxygen to the Sil emission silicon from the LIBS spectra. A calibration curve was obtained by comparing the oxygen concentration determined by LIBS with the oxygen concentration determined by conventional FTIR technique used in Si industies, in which a set of four lightly doped CZ silicon wafers were used. Based on the calibration curve, quantitative oxygen concentration in several heavily doped silicon samples was measured.