Shape variation in epitaxial microstructures of gold silicide grown on Br-passivated Si(111) surfaces

Kinetic Monte Carlo simulations for growth on substrates of three-fold symmetry predict the growth of islands of various shapes depending on the growth temperature [Phys. Rev. Lett. 71 (1993) 2967]. On Br–Si(1 1 1) substrates growth of epitaxial gold silicide islands of equilateral triangular and trapezoidal shapes have earlier been observed by annealing at the Au–Si eutectic temperature,363 � C [Phys. Rev. B 51 (1995) 14330]. We carried out annealing with temperature variation within a small window––(363 ± 30) � C. This has led to island growth of additional shapes like regular hexagon,elongated hexagon,walled hexagon and dendrite. Some of the observed island shapes have not been predicted.