Complementary use of atom probe tomography (APT) and differential hall effect metrology (DHEM) for activation loss in phosphorus-implanted polycrystalline silicon

Abstract

The objectives of this study are to explore the activation ratios of implanted phosphorus dopants in polycrystalline silicon (poly-Si), and to reveal the role of grain boundary segregation in incomplete activation using atom probe tomography (APT) and differential Hall effect metrology (DHEM). After implantation and rapid thermal annealing, the results of APT revealed pronounced segregation toward grain boundaries that provides rapid diffusion paths for phosphorus. Peak concentrations of phosphorus segregations in the grain boundaries of the regrown and non-regrown regions were measured to be 4.38E21 and 2.17E21 atoms/cm³ that correspond to activation ratios of 6 % and 1 %, respectively. In contrast, phosphorus concentrations within grain interiors were found to be 6.86E20 and 1.72E19 atoms/cm³, corresponding to activation ratios of 39 % and nearly 100 % in the regrown and non-regrown regions, respectively. This research highlights a novel approach for evaluating site-specific activation ratios in poly-Si through the integrated use of DHEM and APT.