We discuss a new generation of SPV minority carrier diffusion length metrology with 10-fold improved precision that enables iron detection in silicon wafers in the E8 atom/cm3 range and the extraction of true steady state diffusion length, L0. This improvement is due to full digital control of redesigned hardware and the SPV measuring process. This digital SPV incorporates a novel multi-frequency approach that optimizes Fe detection and extraction of L0. The latter is supported by wafer back surface recombination velocity measurement incorporated in the SPV tool.
