Simulation of the growth dynamics of amorphous and microcrystalline silicon

The qualitative description of the major microstructure characteristics of microcrystalline silicon is achieved through a threedimensional discrete dynamical growth model. The model is based on three fundamental processes that determine surface morphology: (1) random deposition of particles, (2) local relaxation and (3) desorption. In this model, the incoming particle reaching the growing surface takes on a state variable representing a particular way of being incorporated into the material. The state variable is attributed according to a simple selection rule that is characteristic of the model. This model reproduces most of the features of the complex microstructure of microcrystalline silicon: transition from amorphous to crystalline phase, conical shape of the crystalline domains, crystalline fraction evolution with respect to the layer thickness and roughness evolution versus layer thickness.