A numerical model to simulate precipitate growth and ripening in oxygen-implanted silicon-on-insulator materials

A finite element model was developed to simulate the production of silicon-on-insulator substrates through the technique known as SIMOX. The simulation initiates from an as-implanted distribution of SiO2 precipitates and calculates the time evolution during annealing of the number, size and shape of precipitates, until the eventual formation of the buried oxide layer under a surface-silicon layer. During the evolution, the precipitates can grow, dissolve, merge or split and they can adopt arbitrary shapes under the dynamic interaction of the oxygen concentration annealing and capillary forces. The simulations show that the model reproduces several phenomena observed during the SIMOX process, like Ostwald ripening and the formation of silicon islands.