Gettering Variation and Lifetime Characterization on Intentionally Iron, Nickel and Chromium Contaminated Multicrystalline Silicon Wafers

Gettering experiments have been performed using multi-crystalline silicon wafers from highly contaminated feedstock. The transition metal contaminants under investigation were iron, nickel and chromium. A series of gettering variations was accomplished including internal gettering, aluminum gettering and phosphorus diffusion gettering in combination with three different temperature-time profiles. Lifetime characterization by the means of MWPCD and QSSPC showed that a longer tail of moderate temperature after a high temperature firing step might be useful to enhance carrier lifetimes of highly contaminated material.