Strain and Gettering in Epitaxial Silicon Wafers

摘要

External gettering is assessed for epitaxial wafers with lightly and heavily doped substrates. Gettering variants include poly-Si films and mechanical damage. Relative lattice strain at wafer backsides is determined by X-ray diffraction. Relative Fe getterign capability is evaluated using atomic absorption spectroscopy. We find a correlation between initial backside strain in epitaxial wafers and external Fe gettering. Enhanced Fe incorporation into n-type epi layers of n/n~+ epitaxial wafers is observed.