Measurement of Lattice Vacancy-Type Defects in Crystalline Si by a Au Labeling Technique

Vacancy densities and vacancy binding energies have been; quantitatively determined by a Au labeling technique for single crystal Si damaged by high-energy ion implantation. When Au is diffused into the defective Si material, Au atoms are preferentially trapped at vacancies and small vacancy clusters. The volume concentration has been quantitatively calibrated to be 1.2 Au atoms per vacancy(denoted as calibration factor k = 1.2). The technique is potentially capable of obtaining vacancy concentrations in as-grown and processed solar cell Si material by diffusing Au from the surface. Of particular interest is vacancy injection associated with the formation of Al backside contacts. Introduction and diffusion of the Au species and Au profiling is discussed in the context of applyinga Au labeling technique to problems where vacancies play a role in solar cell processing, such as hydrogen passivation and contact formation.