We propose to use the high coherent bright flux of the ESRF for systematic studies of the microscopic dynamics of the annealing process in pentacene films with x-ray photon correlation spectroscopy (XPCS). This will allow us to obtain quantitative information on microscopic diffusion processes which are an essential ingredient for the theoretical modelling and understanding the structure formation of organic semiconductors and associated optoelectronic devices. We expect to establish a protocol for such type of experiments and study the in- and out-of-plane motion of molecules.