Flux dependence of the morphology of a tetracene film on hydrogen-passivated Si(100)

The initial stage of vacuum evaporated tetracene films on hydrogen-passivated Si(100) substrates has been investigated using ex situ atomic force microscopy. Three-dimensional (3D) islands and dendrites are obtained at low deposition rates near equilibrium growth conditions. By increasing the deposition rate to a proper range away from equilibrium conditions, terraced grains are formed with layers of standing molecules and good film connectivity. 3D grains with a high aspect ratio appear once the deposition rate is beyond the optimized range. These flux-dependent results indicate a kinetic path for the formation of uniform tetracene films. The initial growth patterns are discussed within the frame of the morphological instability theory.