A Method of Quantitative Contamination with Metallic Impurities of the Surface of a Silicon Wafer

A method of quantitative and uniform contamination of the surface of a silicon wafer with a metallic impurity in low-level quantities using spin coating with a contaminated aqueous solution was developed. Fe, Ni, Cu and Al were examined and the quantities of these metallic impurities on the surface were controlled by the concentration of metal ions in the contaminated solution. Using this method, the influence on the recombination carrier lifetime was quantitatively investigated. A significant degradation of the recombination lifetime was observed for more than 1011 atoms/cm2 of impurities Cu, Ni and Fe on the surface.