DECOMPOSITION KINETICS OF SUPERSATURATED SOLID-SOLUTIONS IN ION-IMPLANTED SILICON

Supersaturated solid solutions have been prepared by low temperature (550°C) furnace annealing of ion implanted silicon. The stability of such alloys has been investigated as a function of the annealing temperature. Sb and Ga have been implanted in a wide fluences range in Si(100) substrates and annealed in the (550-1050)°C temperature range. Channeling effect technique has been adopted to determine the concentration of substitutional dopants. Electrical measurements and layer removal techniques have been used to determine the concentration profile of electrically active centers. The temperature at which the substitutional concentration decreases depends upon supersaturation ratio. As a general trend the larger is the concentration the lower is the temperature at which incipient precipitation is detected. The kinetics of decomposition is analysed in terms of the dopant diffusivity in the Si solid phase.