Published online by Cambridge University Press: 22 February 2011
A variety of backside damage techniques are available for gettering heavy-metal contaminants in silicon wafers. These include mechanical damage, ion implantation, thin film deposition, and pulsed–laser surface melting. In each case, strain fields and microscopic defects induced by the processing trap impurities as they diffuse through the wafer during subsequent high–temperature processing steps. We examine the defect structures produced by CW laser gettering, describe the dependence of gettering efficiency on wafer oxygen content and processing conditions, and demonstrate that CW laser processing can be an effective gettering technique even when the number of laser scan lines is reduced to make wafer processing acceptably rapid.