Conditions for the generation of nano-sized Au agglomerates in Si

Abstract

The conditions for the generation of nano-sized Au agglomerates in Si, which were recently discovered by the author, have been investigated. The agglomerates can be generated under very limited conditions. The agglomerates are generated with a continuous annealing method but are not generated with a typical ordinary annealing method. They are generated at an annealing temperature of 900 °C but not at 930 °C. Agglomerates are not generated in regions less than 6 μm from the surface. They are generated in a sample that is initially supersaturated with Au atoms at 7.5 × 10¹⁶ cm⁻³ but are only generated at the boundary of the out-diffusion in a sample that initially contains Au atoms at 2.5 × 10¹⁶ cm⁻³. Generation of the agglomerates becomes difficult as the time to cool to the annealing temperature increases in the continuous annealing process. The generated agglomerates dissolve and disappear as the surrounding Au concentration decreases to the thermal equilibrium value, that is, as the sample recovers from the supersaturation of the surrounding Au.